Gli autori vorrebbero riconoscere la ricezione sia della Pediatric Orthopaedic Society of North America Biomet Spine Grant che del National Institutes of Health Clinical and Translational Science Institute KL2 Grant, e della HH Lee Surgical Research Grant come principali fonti di finanziamento per questi esperimenti.

Tutti gli animali sono stati trattati in stretta conformità con le buone pratiche animali, come definito nei regolamenti federali come stabilito nell'Animal Welfare Act (AWA), nella Guida del 1996 per la cura e l'uso degli animali da laboratorio, nella politica PHS per la cura e l'uso umano degli animali da laboratorio, nonché nelle politiche e procedure dell'istituzione come stabilito nel Manuale di formazione per la cura e l'uso degli animali. e tutto il lavoro sugli animali è stato approvato dal Comitato per la Ricerca Animale (ARC) del Cancelliere dell'Università della California di Los Angeles.
1. Scelta del ceppo bioluminescente di S. aureus
<ol><li>Utilizzare il ceppo bioluminescente di S. aureus Xen36 come inoculo di interesse. NOTA: Questo ceppo è stato derivato dal ceppo parentale S. aureus ATCC-49525, che è un isolato clinico di un paziente settico. S. aureus Xen36 utilizza in modo univoco un operone ABCDE lux, che è ottimizzato e integrato nel plasmide nativo dell'ospite. 19 Di conseguenza, il ceppo Xen36 è in grado di produrre una luce bioluminescente blu-verde con un'emissione di lunghezza d'onda di picco di 490 nm. Questo segnale di emissione è prodotto solo da organismi batterici metabolicamente attivi viventi.</li>
</ol>2. Preparazione di S. aureo per inoculazione
<ol><li>Aggiungere 200 μg/mL di kanamicina al brodo di Luria più l'1,5% di agar per isolare S. aureus Xen36 da potenziali contaminanti, utilizzando il gene di resistenza alla kanamicina legato all'operone lux 19.</li>
	<li>Versare i batteri S. aureus Xen36 su piastre di agar di soia triptica (brodo di soia triptico [TSB] più 1,5% di agar) e incubare a 37 °C per 12-16 ore.</li>
	<li>Isolare singole colonie di S. aureus Xen36 e colcolare singolarmente in TSB per 12-16 ore a 37 °C in un incubatore ad agitazione (200 giri/min).</li>
	<li>Diluire la coltura risultante in un rapporto 1:50.</li>
	<li>Coltura per ulteriori 2 ore a 37 °C per isolare i batteri in fase mediologaritmica.</li>
	<li>Pellettare, risospendere e lavare i batteri in soluzione salina tamponata con fosfato (PBS) tre volte.</li>
	<li>Misurare l'assorbanza a 600 nm. L'OD600 ideale è compreso tra 0,700 e 0,750 che corrisponde a 4x105 CFU/mL. Eseguire diluizioni seriali per ottenere l'inoculo batterico desiderato (1 x 103 CFU/2 μL). NOTA: La concentrazione ottimale di Xen36 per l'instaurarsi di un'infezione cronica è risultata essere 1 x 103 CFU. Un dosaggio più basso di batteri è stato eliminato dal sistema immunitario dell'ospite e un dosaggio più elevato ha causato la rottura della ferita. La rottura della ferita non distingue tra un'infezione profonda dell'impianto e un'infezione superficiale della ferita e viene quindi evitata in questo modello (Figura 1)20.</li>
</ol>3. Topi
<ol><li>Utilizzare topi maschi di tipo selvatico C57BL/6J di 12 settimane.</li>
	<li>Topi domestici in gabbie con un massimo di 4 alla volta.</li>
	<li>Tenere sempre a disposizione l'acqua. Mantenere un ciclo luce/buio di 12 ore e non eseguire esperimenti durante la fase oscura del ciclo.</li>
	<li>Utilizzare cibo privo di erba medica per l'alimentazione a causa della potenziale interferenza con la segnalazione fluorescente.</li>
	<li>Chiedere al personale di ricerca o veterinario di valutare quotidianamente i topi per garantire il benessere degli animali durante l'intero esperimento.</li>
</ol>4. Procedure chirurgiche del topo
<ol><li>Indurre l'anestesia mettendo i topi in una camera di isoflurano (2%) per circa 5 minuti. Confermare l'appropriata profondità dell'anestesia monitorando che la respirazione rimanga ritmica e più lenta rispetto a quando si è svegli e non cambi in risposta a stimoli nocivi (ad esempio, manipolazione chirurgica, pizzicamento delle dita dei piedi).</li>
	<li>Trasferire i topi anestetizzati in una stazione di preparazione e rimuovere i peli dall'osso sacro alla colonna vertebrale toracica superiore con tosatrici per roditori.</li>
	<li>Pulisci e sterilizza la pelle con tripli lavaggi di soluzione alternata di betadina e alcol isopropilico.</li>
	<li>Trasferire topi anestetizzati e sterilizzati in posizione prona su un letto chirurgico sterile mantenendo l'anestesia con somministrazione di isoflurano per via inalatoria (2%) tramite cono nasale.</li>
	<li>Flettere al massimo i fianchi e identificare la posizione del ginocchio a livello della colonna vertebrale per approssimare il corpo vertebrale lombare 4.</li>
	<li>Praticare un'incisione longitudinale di 2 cm attraverso la pelle con un bisturi chirurgico a 15 lame.</li>
	<li>Palpare i processi spinosi per confermare la linea mediana e continuare l'incisione fino all'osso.</li>
	<li>Sezionare sottoperiostale sul lato destro del processo spinoso L4, estendendosi lateralmente al processo trasverso.</li>
	<li>Passare una sutura intrecciata assorbibile di misura 5-0 cefalad e caudad al corpo L4 attraverso la fascia e lasciare aperta, in preparazione per la futura chiusura.</li>
	<li>Utilizzando un ago spinale da 25 G, alesare il processo spinoso di L4 utilizzando un ago spinale da 25 G e inserire un impianto chirurgico in acciaio inossidabile di grado "L" di 0,1 mm di diametro, lungo 1 cm, lungo 1 cm lungo la lamina con il braccio lungo che posa cefalica.</li>
	<li>Inoculare l'impianto con 1 x 103 CFU/2 μL di S. aureus Xen36 bioluminescente, avendo cura di assicurarsi che tutta la soluzione entri in contatto con l'impianto.</li>
	<li>Attendere circa 10 secondi prima di legare la sutura assorbibile precedentemente passata dopo l'inoculazione per garantire il contenimento dell'inoculo sull'impianto.</li>
	<li>Chiudi la pelle in modo da corsa con sutura riassorbibile.</li>
	<li>Somministrare farmaci antidolorifici tramite iniezione sottocutanea di buprenorfina (0,1 mg/kg) immediatamente dopo postop e poi ogni 12 ore per 3 giorni successivi.</li>
	<li>Recupera i mouse su un termoforo e monitora il ritorno alla normale attività.</li>
	<li>Ottenere radiografie postoperatorie per confermare il posizionamento appropriato dell'impianto.</li>
</ol>5. Imaging longitudinale in bioluminescenza in vivo per misurare la carica batterica
<ol><li>Anestetizzare i topi con isoflurano per via inalatoria (2%). Confermare l'appropriata profondità dell'anestesia monitorando che la respirazione rimanga ritmica e più lenta rispetto a quando si è svegli e non cambi in risposta a stimoli nocivi (ad esempio, manipolazione chirurgica, pizzicamento delle dita dei piedi).</li>
	<li>Rimuovere i peli dall'osso sacro alla parte superiore della colonna vertebrale toracica con un tagliarodi.</li>
	<li>Caricare i topi sul campo visivo della piattaforma di imaging bioluminescente per eseguire l'imaging a bioluminescenza (BLI) in vivo19.</li>
	<li>Cattura il segnale bioluminescente in un tempo di acquisizione di 5 minuti. Utilizzare impostazioni di binning di grandi dimensioni con un campo visivo di 15 cm (B).</li>
	<li>Ripetere i passaggi 5.1-5.4 nei giorni postoperatori 0, 1, 3, 5, 7, 10, 14, 18, 21, 25, 28 e 35 (o altri giorni in base a un disegno sperimentale specifico) per monitorare la carica batterica.</li>
	<li>Presenta i dati BLI tramite scala di colori e sovrapposizione su una fotografia in scala di grigi. Isolare una regione di interesse ovoidale (ROI) standard utilizzando il software BLI per quantificare il BLI nel flusso totale (fotoni al secondo) o nel flusso massimo medio (fotoni/secondo/centimetro2/steradiante).</li>
</ol>6. Quantificare i batteri aderenti agli impianti e ai tessuti circostanti
<ol><li>Sopprimere i topi con POD 35 o una data post-operatoria alternativa a scelta con esposizione all'anidride carbonica in conformità con le linee guida AVMA. Confermare l'eutanasia con lussazione cervicale secondaria.</li>
	<li>Sterilizzare la pelle dorsale secondo il passaggio 4.3 e posizionare il topo prono su un campo chirurgico sterile.</li>
	<li>Incidere nettamente l'incisione precedente utilizzando un bisturi chirurgico a 15 lame.</li>
	<li>Utilizzare forbici sterili per sezionare senza mezzi termini il processo spinoso L4 e identificare l'impianto chirurgico.</li>
	<li>Utilizzare un cacciavite ad ago per ruotare delicatamente e rimuovere l'impianto dalla sua posizione nel processo spinoso L4.</li>
	<li>Utilizzando pinze e forbici sterili, prelevare circa 0,1 g di osso spinoso e tessuto molle immediatamente circostante l'impianto chirurgico e posizionare 1 ml di PBS in un piccolo tubo conico di rinoceronte con 4 perline omogeneizzanti affilate.</li>
	<li>Registrare il peso dei tessuti molli pesando una provetta conica prima e dopo il raccolto.</li>
	<li>Posizionare l'impianto in 0,5 ml di Tween-80 allo 0,3% in TSB e sonicare per 15 minuti.</li>
	<li>Vorticare la sospensione dell'impianto risultante per 2 minuti e coltura durante la notte per 12-16 ore.</li>
	<li>Omogeneizzare i tessuti molli e i processi spinosi precedentemente inseriti in 1 ml di PBS che circonda l'impianto utilizzando l'omogeneizzatore.</li>
	<li>Agitare la sospensione dei tessuti molli risultante per 5 minuti e coltura per una notte per 12-16 ore.</li>
	<li>Dopo la coltura notturna, contare rispettivamente la CFU dall'impianto e dai tessuti circostanti. Esprimere il valore come CFU/g totali raccolti per i tessuti molli e CFU/mL per l'impianto sonicato.</li>
</ol>

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Le infezioni correlate all'impianto nella colonna vertebrale fanno presagire esiti negativi per i pazienti 1,2,3,4,5. A differenza di molte altre aree del corpo, l'hardware infetto nella colonna vertebrale spesso non può essere rimosso a causa del rischio di instabilità e compromissione neurologica. Questa sfida unica nel contesto dei batteri a biofilm resis...

An erratum was issued for:&#160;<a href="https://www.jove.com/t/60560">In vivo Mouse Model of Spinal Implant Infection</a>. The Authors section was updated from:
Benjamin V. Kelley1 
Stephen D. Zoller1 
Danielle Greig1 
Kellyn Hori1 
Nicolas Cevallos1 
Chad Ishmael1 
Peter Hsiue1 
Rishi Trikha1 
Troy Sekimura2 
Thomas Olson2 
Ameen Chaudry2 
Michael M. Le2 
Anthony A. Scaduto1 
Kevin P. Francis1 
Nicholas M. Bernthal1 
1Department of Orthopaedic Surgery, University of California Los Angeles 
2David Geffen School of Medicine, University of California Los Angeles
to:
Benjamin V. Kelley1 
Christopher Hamad1 
Stephen D. Zoller1 
Danielle Greig1 
Zeinab Mamouei1 
Rene Chun1 
Kellyn Hori1 
Nicolas Cevallos1 
Chad Ishmael1 
Peter Hsiue1 
Rishi Trikha1 
Troy Sekimura2 
Brandon Gettleman3 
Autreen Golzar2 
Adrian Lin2 
Thomas Olson2 
Ameen Chaudry2 
Michael M. Le2 
Anthony A. Scaduto1 
Kevin P. Francis1 
Nicholas M. Bernthal1 
1Department of Orthopaedic Surgery, University of California Los Angeles 
2David Geffen School of Medicine, University of California Los Angeles 
3University of South Carolina School of Medicine, University of South Carolina

An erratum was issued for:&#160;<a href="https://www.jove.com/t/60560">In vivo Mouse Model of Spinal Implant Infection</a>. The Authors section was updated.

Erratum: In vivo Mouse Model of Spinal Implant Infection

Lo scopo di questo metodo è quello di descrivere un nuovo modello murino di infezione da impianto spinale (SII). Questo modello è stato progettato per fornire uno strumento economico e accurato per valutare in modo flessibile l'effetto delle variabili dell'ospite, dell'agente patogeno e/o dell'impianto in vivo. Il test di potenziali terapie e strategie di trattamento per le infezioni da impianti spinali in questo modello ha lo scopo di guidare lo sviluppo della ricerca prima dell'applicazione in modelli animali più grandi e studi clinici.
L'infezione correlata all'impianto dopo un intervento chirurgico alla colonna vertebrale è una complicanza devastante e purtroppo si verifica in circa il 3-8% dei pazienti sottoposti a chirurgia elettiva della colonna vertebrale 1,2,3,4,5 e fino al 65% dei pazienti sottoposti a chirurgia multilivello o di revisione 6. Il trattamento delle infezioni da impianti spinali spesso richiede più ricoveri, più interventi chirurgici e una terapia antibiotica prolungata. Le SII fanno presagire esiti negativi per i pazienti, tra cui compromissione neurologica, disabilità e un aumento del rischio di mortalità. La gestione della SII è estremamente costosa e costa fino a 900.000 dollari per paziente7.
Lo Staphylococcus aureus è il patogeno virulento più comune di SII 8,9,10,11. I batteri possono seminare l'hardware direttamente durante l'intervento chirurgico, attraverso la ferita durante il periodo postoperatorio o successivamente attraverso la diffusione ematogena. In presenza di impianti metallici, S. aureus forma un biofilm che protegge i batteri dalla terapia antibiotica e le cellule immunitarie. Sebbene la rimozione dell'hardware infetto possa aiutare a sradicare efficacemente un'infezione, ciò non è spesso fattibile nella colonna vertebrale senza causare destabilizzazione e rischiare una compromissione neurologica12.
In assenza di espianto di hardware infetto, sono necessari nuovi approcci per prevenire, rilevare e trattare la SII. Storicamente, ci sono stati modelli animali limitati di SII per valutare in modo efficiente la sicurezza e l'efficacia di nuove terapie. I precedenti modelli animali di SII richiedevano un gran numero di animali e la raccolta di dati che richiedevano l'eutanasia, tra cui il conteggio delle colonie, l'istologia e la coltura13,14,15. Mancando di un monitoraggio longitudinale in vivo, questi modelli forniscono solo un punto dati per animale e sono quindi costosi e inefficienti.
Un precedente lavoro che studiava un modello murino di infezione da artroplastica del ginocchio ha stabilito il valore e l'accuratezza dell'imaging ottico in vivo non invasivo per monitorare longitudinalmente il carico di infezione16. Il rilevamento della bioluminescenza consente di quantificare la carica batterica su un decorso temporale longitudinale in un singolo animale in modo umano, accurato ed efficiente. Inoltre, studi precedenti hanno dimostrato un'elevata correlazione tra la bioluminescenza in vivo e le CFU aderenti agli impianti17. La capacità di tracciare l'infezione nel tempo ha portato a una comprensione più sfumata dell'infezione correlata all'impianto. Inoltre, il monitoraggio longitudinale dell'infezione in questo modo ha permesso di valutare con precisione l'efficacia della terapia antibiotica e dei nuovi antimicrobici16,17,18.
Sfruttando questi strumenti, abbiamo sviluppato e validato un modello di infezione postoperatoria dell'impianto spinale. Nel metodo presentato, utilizziamo un inoculo di S. aureus Xen36 bioluminescente per stabilire un modello murino in vivo di SII per monitorare longitudinalmente la carica batterica16,17,18. Questo nuovo modello fornisce uno strumento prezioso per testare in modo efficiente le potenziali strategie di rilevamento, prevenzione e trattamento per la SII prima della loro applicazione in modelli animali più grandi e studi clinici.

<table>
	<tbody>
		<tr>
			<td>Analytical Balance ME104</td>
			<td>Mettler Toledo</td>
			<td>30029067</td>
			<td>120 g capacity, 0.1 mg readability, backlit LCD, internal adjustment, metal base</td>
		</tr>
		<tr>
			<td>BD Bacto Tryptic Soy Broth</td>
			<td>Becton Dickinson (BD)</td>
			<td>BD 211825</td>
			<td>BD Bacto Tryptic Soy Broth (Soybean-Casein Digest Medium)</td>
		</tr>
		<tr>
			<td>Biomate 3S UV-VIS Spectrophotometer</td>
			<td>Thermo Scientific</td>
			<td>840-208300</td>
			<td>Spectrophotometer; Thermo Scientific; BioMate 3S; Six-position cell holder; Spectral bandwidth: 1.8nm; Long-life xenon lamp; Store up to 40 test methods; 16L x 13W x 9 in. H; 19 lb.; 100/240V US line cord</td>
		</tr>
		<tr>
			<td>Bioshield 720+ swinging bucket rotor</td>
			<td>Thermo Scientific</td>
			<td>75003183</td>
			<td>Rotor, Swinging bucket; Thermo Scientific; BIOShield 720 high speed; Capacity: 4 x 180mL (0.72L); Angle: 90 deg. ; Max. speed/RCF: 6300rpm/7188 x g; Max. radius: 16.2cm</td>
		</tr>
		<tr>
			<td>Branson Ultrasonics 2510R-MTH (Sonicator)</td>
			<td>Branson Ultrasonics</td>
			<td>CPX952217R</td>
			<td>*similar model, our model is discontinued* Branson Ultrasonics MH Series Heated Ultrasonic Cleaning Bath, 120V, 0.75 gal</td>
		</tr>
		<tr>
			<td>Bullet Blender Storm Homogenizer</td>
			<td>Next Advance</td>
			<td>BBY24M</td>
			<td>The Bullet Blender Storm is the most powerful member of the Bullet Blender family. Homogenize up to 24 of your toughest samples (mouse femur, skin, cartilage, tumor, etc.) in just minutes. Air cooling&#8482; minimizes sample heat up. Uses 1.5ml screw-cap RINO&#174; tubes or snap-cap Eppendorf&#174; Safe-lock&#8482; tubes.</td>
		</tr>
		<tr>
			<td>Germinator 500</td>
			<td>Electron Microscopy Sciences</td>
			<td>66118-10</td>
			<td>The Germinator 500 is designed to decontaminate metal micro-dissecting instruments only. It is to be 
			used exclusively for research purposes. The Germinator 500 should not be used as a substitute for 
			traditional methods of terminal sterilization. Effective sterilization cannot be assured due to lack of routine 
			sterilization-efficacy monitoring methods for glass bead sterilization. The Germinator 500 has been 
			designed and built to pass the Validation of Dry Sterilizer Spore Suspension Test: USP XXIII, Part 1211.</td>
		</tr>
		<tr>
			<td>Heracell 150i CO2 Incubator</td>
			<td>Thermo Scientific</td>
			<td>51026282</td>
			<td>Single 150L</td>
		</tr>
		<tr>
			<td>IVIS Lumina X5 Imaging System</td>
			<td>Perkin Elmer</td>
			<td>CLS148590</td>
			<td>The IVIS Lumina X5 high-throughput 2D optical imaging system combines high-sensitivity bioluminescence and fluorescence with high-resolution x-ray into a compact system that fits on your benchtop. With an expanded 5 mouse field of view for 2D optical imaging plus our unique line of accessories to accelerate setup and labeling, it has never been easier or faster to get robust data&#8212;and answers&#8212;on anatomical and molecular aspects of disease.</td>
		</tr>
		<tr>
			<td>MAXQ 4450 Digtial Incubating Bench Shaker</td>
			<td>Thermo Scientific</td>
			<td>SHKE4450</td>
			<td>Shaker, Incubated; Thermo Scientific; Digital; MaxQ 4450; Speed 15 to 500rpm +/-1rpm; 5 deg. C above ambient to 80 deg. C; 120V 50/60Hz</td>
		</tr>
		<tr>
			<td>PBS, Phosphate Buffered Saline</td>
			<td>Fisher Bioreagents</td>
			<td>BP24384</td>
			<td>PBS, Phosphate Buffered Saline, 1X Solution, pH 7.4</td>
		</tr>
		<tr>
			<td>Sorvall Legend Micro 21 Centrifuge, Ventilated</td>
			<td>Thermo Scientific</td>
			<td>75002436</td>
			<td>24 x 1.5/2.0mL rotor with ClickSeal biocontainment lid</td>
		</tr>
		<tr>
			<td>SORVALL LEGEND X1R 120V Centrifuge</td>
			<td>Thermo Scientific</td>
			<td>75004261</td>
			<td>Centrifuge, Benchtop; Thermo Scientific; Sorvall Legend X1R (Refrigerated), 1L capacity; Max. Speed/RCF 15,200rpm/25,830 x g; CFC-free cooling -10C to +40C; 120V 60Hz</td>
		</tr>
		<tr>
			<td>Staphylococcus aureus - Xen36</td>
			<td>Perkin Elmer</td>
			<td>119243</td>
			<td>Staphylococcus aureus - Xen36 bioluminescent pathogenic bacteria for in vivo and in vitro drug discovery. This product was derived from a parental strain from the American Type Culture Collection, used under license. Staph. aureus-Xen36 possesses a stable copy of the Photorhabdus luminescens lux operon on the native plasmid.</td>
		</tr>
		<tr>
			<td>TUTTNAUER AUTOCLAVE 2540E 120V</td>
			<td>Heidolph Tuttnauer</td>
			<td>23210401</td>
			<td>Sterilizer, Benchtop; Heidolph; Tuttnauer; Model 2540E; Self-contained design with refillable reservoir controls water purity for sterilization; 120V 50/60Hz; 1400w. With electronic controls</td>
		</tr>
		<tr>
			<td>Tween 80</td>
			<td>Fisher Bioreagents</td>
			<td>BP338-500</td>
			<td>Tween 80, Fisher BioReagents, Non-ionic detergent for selective protein extraction</td>
		</tr>
		<tr>
			<td>Vortex mixer VX-200</td>
			<td>Labnet Internation</td>
			<td>S0200</td>
			<td>120V touch or continuous mixer, 230V: 0 - 2,850 rpm,120V: 0 - 3,400 rpm</td>
		</tr>
		<tr>
			<td>0.9% Sodium Chloride</td>
			<td>Pfizer Injectables/Hospira</td>
			<td>00409-4888-10</td>
			<td>0.9% Sodium Chloride Injection, USP</td>
		</tr>
	</tbody>
</table>

in vivo mouse model of spinal implant infection

Le infezioni da impianti spinali fanno presagire scarsi risultati poiché la diagnosi è difficile e l'eradicazione chirurgica è in contrasto con la stabilità meccanica della colonna vertebrale. Lo scopo di questo metodo è quello di descrivere un nuovo modello murino di infezione da impianto spinale (SII) che è stato creato per fornire uno strumento in vivo economico, rapido e accurato per testare potenziali terapie e strategie di trattamento per le infezioni da impianti spinali.
In questo metodo, presentiamo un modello di chirurgia spinale con approccio posteriore in cui un filo k in acciaio inossidabile viene trafitto nel processo spinoso L4 di topi wild-type C57BL/6J di 12 settimane e inoculato con 1 x 103 CFU di un ceppo bioluminescente di batteri Staphylococcus aureus Xen36. I topi vengono quindi sottoposti a imaging longitudinale per la bioluminescenza in vivo nei giorni post-operatori 0, 1, 3, 5, 7, 10, 14, 18, 21, 25, 28 e 35. I segnali di imaging a bioluminescenza (BLI) provenienti da un campo visivo standardizzato vengono quantificati per misurare la carica batterica in vivo.
Per quantificare i batteri che aderiscono agli impianti e al tessuto perimplantare, i topi vengono sottoposti a eutanasia e vengono raccolti l'impianto e i tessuti molli circostanti. I batteri vengono staccati dall'impianto mediante sonicazione, coltivati durante la notte e quindi vengono contate le unità formanti colonie (CFU). I risultati acquisiti da questo metodo includono la conta batterica longitudinale misurata dalla bioluminescenza in vivo di S. aureus (flusso massimo medio) e la conta delle CFU dopo eutanasia.
Mentre i precedenti modelli animali di infezione della colonna vertebrale strumentata hanno comportato un'analisi invasiva dei tessuti ex vivo, il modello murino di SII presentato in questo documento sfrutta l'imaging ottico in vivo non invasivo e in tempo reale di batteri bioluminescenti per sostituire lo studio statico dei tessuti. Le applicazioni del modello sono ampie e possono includere l'utilizzo di ceppi batterici bioluminescenti alternativi, l'incorporazione di altri tipi di topi geneticamente modificati per studiare contemporaneamente la risposta immunitaria dell'ospite e la valutazione di nuove modalità diagnostiche e terapeutiche come antibiotici o rivestimenti implantari.

La procedura qui presentata è stata utilizzata per valutare l'efficacia dei regimi antibiotici in un modello murino in vivo di SII. In particolare, l'efficacia della terapia antibiotica combinata con vancomicina e rifampicina è stata confrontata con la monoterapia con vancomicina e con i controlli infetti non trattati.
Prima dell'intervento chirurgico, i topi sono stati randomizzati alla terapia di combinazione, alla monoterapia o al controllo infetto. È stata eseguita un'analisi statistica...

Watch this Scientific Journal Video about In Vivo Mouse Model of Spinal Implant Infection at JoVE.com

In Vivo Mouse Model of Spinal Implant Infection

Il protocollo descrive un nuovo modello murino in vivo di infezione da impianto spinale in cui un impianto k-wire in acciaio inossidabile è infettato da Staphylococcus aureus Xen36 bioluminescente. La carica batterica viene monitorata longitudinalmente con imaging bioluminescente e confermata con la conta delle unità formanti colonie dopo l'eutanasia.

Modello murino in vivo di infezione da impianto spinale

Spine implant infections portend poor outcomes as diagnosis is challenging and surgical eradication is at odds with mechanical spinal stability. The ...

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2.2K Views.  University of California Los Angeles. Il protocollo descrive un nuovo modello murino in vivo di infezione da impianto spinale in cui un impianto k-wire in acciaio inossidabile è infettato da Staphylococcus aureus Xen36 bioluminescente. La carica batterica viene monitorata longitudinalmente con imaging bioluminescente e confermata con la conta delle unità formanti colonie dopo l'eutanasia.

Video: In Vivo Mouse Model of Spinal Implant Infection

Ex Vivo Infection of Live Tissue with Oncolytic Viruses

Oncolytic Viruses (OVs) are novel therapeutics that selectively replicate in and kill tumor cells1. Several clinical trials evaluating the effectiveness of a variety of oncolytic platforms including HSV, Reovirus, and Vaccinia OVs as treatment for cancer are currently underway2-5. One key characteristic of oncolytic viruses is that they can be genetically modified to express reporter transgenes which makes it possible to visualize the infection of tissues by microscopy or bio-luminescence imaging6,7. This offers a unique advantage since it is possible to infect tissues from patients ex vivo prior to therapy in order to ascertain the likelihood of successful oncolytic virotherapy8. To this end, it is critical to appropriately sample tissue to compensate for tissue heterogeneity and assess tissue viability, particularly prior to infection9. It is also important to follow viral replication using reporter transgenes if expressed by the oncolytic platform as well as by direct titration of tissues following homogenization in order to discriminate between abortive and productive infection. The object of this protocol is to address these issues and herein describes 1. The sampling and preparation of tumor tissue for cell culture 2. The assessment of tissue viability using the metabolic dye alamar blue 3. Ex vivo infection of cultured tissues with vaccinia virus expressing either GFP or firefly luciferase 4. Detection of transgene expression by fluorescence microscopy or using an In Vivo Imaging System (IVIS) 5. Quantification of virus by plaque assay. This comprehensive method presents several advantages including ease of tissue processing, compensation for tissue heterogeneity, control of tissue viability, and discrimination between abortive infection and bone fide viral replication.

Ex Vivo Infection of Live Tissue with Oncolytic Viruses

Oncolytic viruses are promising for cancer therapeutics. The ability to ascertain the infectability of live tissue specimens obtained from patients prior to treatment is a unique advantage of this therapeutic approach. This protocol describes how to process tissues for ex vivo infection with oncolytic virus and subsequent viral quantification.

Ex infezione Vivo del tessuto Live con virus oncolitici

Oncolytic Viruses (OVs) are novel therapeutics that selectively replicate in and kill tumor cells1. Several clinical trials evaluating the effectiveness ...

Ricerca

Medicina

Longitudinal Evaluation of Mouse Hind Limb Bone Loss After Spinal Cord Injury using Novel, in vivo, Methodology

Spinal cord injury (SCI) is often accompanied by osteoporosis in the sublesional regions of the pelvis and lower extremities, leading to a higher frequency of fractures 1. As these fractures often occur in regions that have lost normal sensory function, the patient is at a greater risk of fracture-dependent pathologies, including death. SCI-dependent loss in both bone mineral density (BMD, grams/cm2) and bone mineral content (BMC, grams) has been attributed to mechanical disuse 2, aberrant neuronal signaling 3 and hormonal changes 4. The use of rodent models of SCI-induced osteoporosis can provide invaluable information regarding the mechanisms underlying the development of osteoporosis following SCI as well as a test environment for the generation of new therapies 5-7 (and reviewed in 8). Mouse models of SCI are of great interest as they permit a reductionist approach to mechanism-based assessment through the use of null and transgenic mice. While such models have provided important data, there is still a need for minimally-invasive, reliable, reproducible, and quantifiable methods in determining the extent of bone loss following SCI, particularly over time and within the same cohort of experimental animals, to improve diagnosis, treatment methods, and/or prevention of SCI-induced osteoporosis.
An ideal method for measuring bone density in rodents would allow multiple, sequential (over time) exposures to low-levels of X-ray radiation. This study describes the use of a new whole-animal scanner, the IVIS Lumina XR (Caliper Instruments) that can be used to provide low-energy (1-3 milligray (mGy)) high-resolution, high-magnification X-ray images of mouse hind limb bones over time following SCI. Significant bone density loss was seen in the tibiae of mice by 10 days post-spinal transection when compared to uninjured, age-matched control (na&iuml;ve) mice (13% decrease, p&lt;0.0005). Loss of bone density in the distal femur was also detectable by day 10 post-SCI, while a loss of density in the proximal femur was not detectable until 40 days post injury (7% decrease, p&lt;0.05). SCI-dependent loss of mouse femur density was confirmed post-mortem through the use of Dual-energy X-ray Absorptiometry (DXA), the current "gold standard" for bone density measurements. We detect a 12% loss of BMC in the femurs of mice at 40 days post-SCI using the IVIS Lumina XR. This compares favorably with a previously reported BMC loss of 13.5% by Picard and colleagues who used DXA analysis on mouse femurs post-mortem 30 days post-SCI 9. Our results suggest that the IVIS Lumina XR provides a novel, high-resolution/high-magnification method for performing long-term, longitudinal measurements of hind limb bone density in the mouse following SCI.

Longitudinal Evaluation of Mouse Hind Limb Bone Loss After Spinal Cord Injury using Novel, in vivo, Methodology

A longitudinal examination of bone loss in the femurs and tibiae of adult mice was performed following spinal cord injury using sequential low-dose X-ray scans. Tibia bone loss was detected throughout the study, while bone loss in the femur was not detected until 40 days post injury.

La valutazione longitudinale di perdita dell&#39;arto posteriore ossea del mouse dopo la lesione del midollo spinale tramite Novel, In vivo, Metodologia

Spinal cord injury (SCI) is often accompanied by osteoporosis in the sublesional regions of the pelvis and lower extremities, leading to a higher ...

Clinical Testing and Spinal Cord Removal in a Mouse Model for Amyotrophic Lateral Sclerosis (ALS)

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder resulting in progressive degeneration of motoneurons. Peak of onset is around 60 years for the sporadic disease and around 50 years for the familial disease. Due to its progressive course, 50% of the patients die within 30 months of symptom onset. In order to evaluate novel treatment options for this disease, genetic mouse models of ALS have been generated based on human familial mutations in the SOD gene, such as the SOD1 (G93A) mutation. Most important aspects that have to be evaluated in the model are overall survival, clinical course and motor function. Here, we demonstrate the clinical evaluation, show the conduction of two behavioural motor tests and provide quantitative scoring systems for all parameters. Because an in depth analysis of the ALS mouse model usually requires an immunohistochemical examination of the spinal cord, we demonstrate its preparation in detail applying the dorsal laminectomy method. Exemplary histological findings are demonstrated. The comprehensive application of the depicted examination methods in studies on the mouse model of ALS will enable the researcher to reliably test future therapeutic options which can provide a basis for later human clinical trials.

Clinical Testing and Spinal Cord Removal in a Mouse Model for Amyotrophic Lateral Sclerosis ALS

A mouse model for amyotrophic lateral sclerosis (ALS) is examined clinically and behaviorally. As a prerequisite for an accompanying immunohistological analysis the preparation of the spinal cord is depicted in detail.

Test clinici e la rimozione del midollo spinale in un modello murino di sclerosi laterale amiotrofica (SLA)

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder resulting in progressive degeneration of motoneurons. Peak of onset is around 60 ...

A Contusion Model of Severe Spinal Cord Injury in Rats

The translational potential of novel treatments should be investigated in severe spinal cord injury (SCI) contusion models. A detailed methodology is described to obtain a consistent model of severe SCI. Use of a stereotactic frame and computer controlled impactor allows for creation of reproducible injury. Hypothermia and urinary tract infection pose significant challenges in the post-operative period. Careful monitoring of animals with daily weight recording and bladder expression allows for early detection of post-operative complications. The functional results of this contusion model are equivalent to transection models. The contusion model can be utilized to evaluate the efficacy of both neuroprotective and neuroregenerative approaches.

A contusion model of severe spinal cord injury is described. Detailed pre-operative, operative and post-operative steps are described to obtain a consistent model.

Un modello Contusione di gravi lesioni del midollo spinale nei ratti

The translational potential of novel treatments should be investigated in severe spinal cord injury (SCI) contusion models. A detailed methodology is ...

Combined In vivo Optical and &#181;CT Imaging to Monitor Infection, Inflammation, and Bone Anatomy in an Orthopaedic Implant Infection in Mice

Multimodality imaging has emerged as a common technological approach used in both preclinical and clinical research. Advanced techniques that combine in vivo optical and &#956;CT imaging allow the visualization of biological phenomena in an anatomical context. These imaging modalities may be especially useful to study conditions that impact bone. In particular, orthopaedic implant infections are an important problem in clinical orthopaedic surgery. These infections are difficult to treat because bacterial biofilms form on the foreign surgically implanted materials, leading to persistent inflammation, osteomyelitis and eventual osteolysis of the bone surrounding the implant, which ultimately results in implant loosening and failure. Here, a mouse model of an infected orthopaedic prosthetic implant was used that involved the surgical placement of a Kirschner-wire implant into an intramedullary canal in the femur in such a way that the end of the implant extended into the knee joint. In this model, LysEGFP mice, a mouse strain that has EGFP-fluorescent neutrophils, were employed in conjunction with a bioluminescent Staphylococcus aureus strain, which naturally emits light. The bacteria were inoculated into the knee joints of the mice prior to closing the surgical site. In vivo bioluminescent and fluorescent imaging was used to quantify the bacterial burden and neutrophil inflammatory response, respectively. In addition, &#956;CT imaging was performed on the same mice so that the 3D location of the bioluminescent and fluorescent optical signals could be co-registered with the anatomical &#956;CT images. To quantify the changes in the bone over time, the outer bone volume of the distal femurs were measured at specific time points using a semi-automated contour based segmentation process. Taken together, the combination of in vivo bioluminescent/fluorescent imaging with &#956;CT imaging may be especially useful for the noninvasive monitoring of the infection, inflammatory response and anatomical changes in bone over time.

Combined In vivo Optical and  &amp;#181;CT Imaging to Monitor Infection, Inflammation, and Bone Anatomy in an Orthopaedic Implant Infection in Mice

Combined optical and &#956;CT imaging in a mouse model of orthopaedic implant infection, utilizing a bioluminescent engineered strain of Staphylococcus aureus, provided the capability to noninvasively and longitudinally monitor the dynamics of the bacterial infection, as well as the corresponding inflammatory response and anatomical changes in the bone.

Combinato<em&gt; In vivo</em&gt; Optical e μCT Imaging Monitor per infezione, infiammazione, e Bone Anatomy in una infezione ortopedica impianto in topi

Multimodality imaging has emerged as a common technological approach used in both preclinical and clinical research. Advanced techniques that combine in ...

Controlled Cortical Impact Model for Traumatic Brain Injury

Every year over a million Americans suffer a traumatic brain injury (TBI). Combined with the incidence of TBIs worldwide, the physical, emotional, social, and economical effects are staggering. Therefore, further research into the effects of TBI and effective treatments is necessary. The controlled cortical impact (CCI) model induces traumatic brain injuries ranging from mild to severe. This method uses a rigid impactor to deliver mechanical energy to an intact dura exposed following a craniectomy. Impact is made under precise parameters at a set velocity to achieve a pre-determined deformation depth. Although other TBI models, such as weight drop and fluid percussion, exist, CCI is more accurate, easier to control, and most importantly, produces traumatic brain injuries similar to those seen in humans. However, no TBI model is currently able to reproduce pathological changes identical to those seen in human patients. The CCI model allows investigation into the short-term and long-term effects of TBI, such as neuronal death, memory deficits, and cerebral edema, as well as potential therapeutic treatments for TBI.

Traumatic brain injuries (TBIs) remain a serious health problem. Using the controlled cortical impact surgery model, research on the effects of TBI and possible treatment methods may be performed.

Controllata corticale modello Impact per trauma cranico

Every year over a million Americans suffer a traumatic brain injury (TBI).  Combined with the incidence of TBIs worldwide, the physical, emotional, ...

Intrauterine Telemetry to Measure Mouse Contractile Pressure In Vivo

A complex integration of molecular and electrical signals is needed to transform a quiescent uterus into a contractile organ at the end of pregnancy. Despite the discovery of key regulators of uterine contractility, this process is still not fully understood. Transgenic mice provide an ideal model in which to study parturition. Previously, the only method to study uterine contractility in the mouse was ex vivo isometric tension recordings, which are suboptimal for several reasons. The uterus must be removed from its physiological environment, a limited time course of investigation is possible, and the mice must be sacrificed. The recent development of radiometric telemetry has allowed for longitudinal, real-time measurements of in vivo intrauterine pressure in mice. Here, the implantation of an intrauterine telemeter to measure pressure changes in the mouse uterus from mid-pregnancy until delivery is described. By comparing differences in pressures between wild type and transgenic mice, the physiological impact of a gene of interest can be elucidated. This technique should expedite the development of therapeutics used to treat myometrial disorders during pregnancy, including preterm labor.

Intrauterine Telemetry to Measure Mouse Contractile Pressure In Vivo

This manuscript provides a protocol for implanting telemeters in the mouse for the purpose of measuring intrauterine pressures during pregnancy.

Telemetria intrauterina misurare mouse contrattile Pressione<em&gt; In Vivo</em

A complex integration of molecular and electrical signals is needed to transform a quiescent uterus into a contractile organ at the end of pregnancy. ...

A Neonatal Mouse Spinal Cord Compression Injury Model

Spinal cord injury (SCI) typically causes devastating neurological deficits, particularly through damage to fibers descending from the brain to the spinal cord. A major current area of research is focused on the mechanisms of adaptive plasticity that underlie spontaneous or induced functional recovery following SCI. Spontaneous functional recovery is reported to be greater early in life, raising interesting questions about how adaptive plasticity changes as the spinal cord develops. To facilitate investigation of this dynamic, we have developed a SCI model in the neonatal mouse. The model has relevance for pediatric SCI, which is too little studied. Because neural plasticity in the adult involves some of the same mechanisms as neural plasticity in early life1, this model may potentially have some relevance also for adult SCI. Here we describe the entire procedure for generating a reproducible spinal cord compression (SCC) injury in the neonatal mouse as early as postnatal (P) day 1. SCC is achieved by performing a laminectomy at a given spinal level (here described at thoracic levels 9-11) and then using a modified Yasargil aneurysm mini-clip to rapidly compress and decompress the spinal cord. As previously described, the injured neonatal mice can be tested for behavioral deficits or sacrificed for ex vivo physiological analysis of synaptic connectivity using electrophysiological and high-throughput optical recording techniques1. Earlier and ongoing studies using behavioral and physiological assessment have demonstrated a dramatic, acute impairment of hindlimb motility followed by a complete functional recovery within 2 weeks, and the first evidence of changes in functional circuitry at the level of identified descending synaptic connections1.

This article describes a method for generating a reproducible spinal cord compression injury (SCI) in the neonatal mouse. The model provides an advantageous platform for studying mechanisms of adaptive plasticity that underlie spontaneous functional recovery.

Un neonatale mouse Spinal Cord Injury compressione Modello

Spinal cord injury (SCI) typically causes devastating neurological deficits, particularly through damage to fibers descending from the brain to the spinal ...

Stem-cell Based Engineered Immunity Against HIV Infection in the Humanized Mouse Model

With the rapid development of stem cell-based gene therapies against HIV, there is pressing requirement for an animal model to study the hematopoietic differentiation and immune function of the genetically modified cells. The humanized Bone-marrow/Liver/Thymus (BLT) mouse model allows for full reconstitution of a human immune system in the periphery, which includes T cells, B cells, NK cells and monocytes. The human thymic implant also allows for thymic selection of T cells in autologous thymic tissue. In addition to the study of HIV infection, the model stands as a powerful tool to study differentiation, development and functionality of cells derived from hematopoietic stem cells (HSCs). Here we outline the construction of humanized non-obese diabetic (NOD)-severe combined immunodeficient (SCID)-common gamma chain knockout (c&#947;-/-)-Bone-marrow/Liver/Thymus (NSG-BLT) mice with HSCs transduced with CD4 chimeric antigen receptor (CD4CAR) lentivirus vector. We show that the CD4CAR HSCs can successfully differentiate into multiple lineages and have anti-HIV activity. The goal of the study is to demonstrate the use of NSG-BLT mouse model as an in vivo model for engineered immunity against HIV. It is worth noting that, because lentivirus and human tissue is used, experiments and surgeries should be performed in a Class II biosafety cabinet in a Biosafety Level 2 (BSL2) with special precautions (BSL2+) facility.

This protocol describes the methods in constructing a humanized bone-marrow/liver/thymus mouse model with stem cell-based engineered immunity against HIV infection.

Cellule staminali base Immunità Engineered contro l&#39;infezione da HIV nel modello umanizzato mouse

With the rapid development of stem cell-based gene therapies against HIV, there is pressing requirement for an animal model to study the hematopoietic ...

Depletion of Mouse Cells from Human Tumor Xenografts Significantly Improves Downstream Analysis of Target Cells

The use of in vitro cell line models for cancer research has been a useful tool. However, it has been shown that these models fail to reliably mimic patient tumors in different assays1. Human tumor xenografts represent the gold standard with respect to tumor biology, drug discovery, and metastasis research 2-4. Tumor xenografts can be derived from different types of material like tumor cell lines, tumor tissue from primary patient tumors4 or serially transplanted tumors. When propagated in vivo, xenografted tissue is infiltrated and vascularized by cells of mouse origin. Multiple factors such as the tumor entity, the origin of xenografted material, growth rate and region of transplantation influence the composition and the amount of mouse cells present in tumor xenografts. However, even when these factors are kept constant, the degree of mouse cell contamination is highly variable.
Contaminating mouse cells significantly impair downstream analyses of human tumor xenografts. As mouse fibroblasts show high plating efficacies and proliferation rates, they tend to overgrow cultures of human tumor cells, especially slowly proliferating subpopulations. Mouse cell derived DNA, mRNA, and protein components can bias downstream gene expression analysis, next-generation sequencing, as well as proteome analysis 5. To overcome these limitations, we have developed a fast and easy method to isolate untouched human tumor cells from xenografted tumor tissue. This procedure is based on the comprehensive depletion of cells of mouse origin by combining automated tissue dissociation with the benchtop tissue dissociator and magnetic cell sorting. Here, we demonstrate that human target cells can be can be obtained with purities higher than 96% within less than 20 min independent of the tumor type.

Human tumor xenografts are vascularized and infiltrated by cells of mouse origin during the growth phase in vivo. To circumvent the bias caused by these contaminating cells during downstream analysis, we developed a method allowing for comprehensive depletion of all mouse cells by magnetic cell sorting.

L&#39;esaurimento delle cellule di topo da xenotrapianti tumorali umani migliora in modo significativo Analisi A valle delle cellule bersaglio

The use of in vitro cell line models for cancer research has been a useful tool. However, it has been shown that these models fail to reliably mimic ...