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1.
PM R ; 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38578137

RESUMO

BACKGROUND: Due to the virtual format of fellowship applications, prospective physical medicine and rehabilitation (PM&R) sports medicine fellowship applicants commonly rely upon fellowship website content to make decisions about applications. Studies have shown that information available to fellowship applicants on program websites is inadequate, and there is no standard for important components of sports medicine fellowship websites. OBJECTIVE: To determine what sports medicine fellowship program features PM&R residents, fellows, and attending physicians consider the most important to be listed on fellowship websites, as well as to assess the scope of information available on fellowship websites. DESIGN: We developed a 30-item list of criteria that fell into categories of general information, fellowship education, recruitment, experience, and academic research. Survey participants were asked to rank the importance of those various items. We then assessed the 21 PM&R accredited sports medicine fellowship websites for the presence of these criteria. PARTICIPANTS: Ninety-six survey respondents composed of PM&R residents, current sports medicine fellows, and attendings. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE(S): Not applicable. RESULTS: Items ranked as most important were those in the categories of general information, fellowship experience, and fellowship recruitment. The most valued items were program location, program coordinator contact information, program length, specific requirements for applying, number of positions, types of procedures taught, and specific sites covered. Academic research items were ranked as least important. CONCLUSIONS: Survey respondents identified many fellowship website items as important factors when applying to programs. Many of these items were not listed on fellowship websites, suggesting that adding these criteria to fellowship sites might benefit applicants. Our findings can be used to develop standardized criteria for important components of sports medicine fellowship websites to improve the application and recruitment process.

2.
Knee ; 47: 35-42, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38181461

RESUMO

BACKGROUND: Rotating hinge knee replacements are becoming more common but have historically had high complication and failure rates. This study is one of the largest to assess the implant survival and patient outcomes of a third-generation rotating hinge knee replacement at a single tertiary orthopaedic centre. METHODS: Data for consecutive operations at our tertiary unit between 2006 to 2020 were assessed with review of electronic patient and radiology records. The Oxford Knee Score was used to assess outcomes and the Kaplan Meier method used to estimate survivorship. RESULTS: 53 rotating hinge knees were implanted in 46 patients (13 male, 33 female) at a mean age of 67.8 years. 21 were primary and 32 were revision procedures. Indications for use of this implant included instability, loosening, fracture and infection. Survivorship was 77.8% at the mean follow up of 7.6 years. A total of 29 complications were noted with ongoing pain, stiffness, infection and patellofemoral symptoms being the most common. 8% of unresurfaced patellas required a subsequent secondary resurfacing. The Oxford Knee Score demonstrated a significant improvement from 14.6 preoperatively to 27.5 at one year postoperatively, which was maintained in the longer term. CONCLUSION: The third-generation rotating hinge knee implant in use at our unit has improved outcomes for patients. The survivorship of the implant is comparable to the published literature, although there is a paucity of data. The complication rates remain relatively high and patients should be counselled appropriately. We advise resurfacing the patella to avoid the need for secondary procedures.


Assuntos
Artroplastia do Joelho , Prótese do Joelho , Desenho de Prótese , Humanos , Masculino , Feminino , Idoso , Artroplastia do Joelho/instrumentação , Artroplastia do Joelho/métodos , Seguimentos , Pessoa de Meia-Idade , Falha de Prótese , Estudos Retrospectivos , Idoso de 80 Anos ou mais , Reoperação , Resultado do Tratamento , Complicações Pós-Operatórias/epidemiologia
4.
Indian J Plast Surg ; 55(3): 221-223, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36325077
5.
Pain Physician ; 25(8): 521-530, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36375180

RESUMO

BACKGROUND: Complex Regional Pain Syndrome (CRPS) is a chronic debilitating neuropathic pain condition characterized by autonomic and inflammatory features that typically occurs after a traumatic event. Spinal cord stimulation (SCS) has been shown to be effective in the treatment of chronic CRPS refractory to conventional treatment modalities. The collective evidence of novel parameters of SCS for treating CRPS has not been characterized extensively. OBJECTIVE: To provide evidence for the use of SCS to treat CRPS and characterize the additional benefits of various SCS waveforms. STUDY DESIGN: Systematic Review and Meta-analysis. METHODS: PubMed, Embase and CINHLA were screened for all randomized controlled trials (RCT) comparing SCS parameters for the treatment of CRPS. RESULTS: Four RCTs were identified that included SCS as a treatment arm for CRPS. Of these, one study compared low frequency tonic SCS (LF-SCS) versus conventional physical therapy, 2 studies compared placebo/sham SCS with LF-SCS and a multitude of waveforms, and one study compared LF-SCS with high-frequency SCS (HF-SCS). Two of the studies were rated as having a low risk of bias, one study was rated as having some concerns for bias, while the final study was rated as having a high risk of bias. A meta-analysis of 4 studies comparing conventional therapy/placebo SCS stimulation against LF-SCS revealed increased benefit of LF-SCS in pain reduction up to a month (mean difference [MD] = -1.17 points; 95% CI = -1.61 to -0.73; P < 0.001, I2 = 42%). Another meta-analysis of 2 studies showed that LF-SCS results in higher global perceived effect scores relative to conventional therapy/placebo SCS stimulation (MD = 1.58; 95% CI = 1.00 to 2.15; P < 0.001, I2 = 0%). LIMITATIONS: A pooled analysis using different designs for RCTs was conducted. Some studies folded in multiple neuropathic pain pathologies in addition to CRPS. One study was at a high risk for bias in at least one domain. CONCLUSION: LF-SCS is superior to conventional therapy/placebo SCS stimulation. However, more evidence is required to demonstrate that novel SCS parameters are superior to LF-SCS in improving pain scores and functional outcomes.


Assuntos
Síndromes da Dor Regional Complexa , Neuralgia , Estimulação da Medula Espinal , Humanos , Estimulação da Medula Espinal/métodos , Ensaios Clínicos Controlados Aleatórios como Assunto , Síndromes da Dor Regional Complexa/terapia , Medição da Dor/métodos , Medula Espinal , Resultado do Tratamento
6.
Knee ; 33: 260-265, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34739957

RESUMO

BACKGROUND: Postoperative fixed flexion deformity is a known complication of knee replacement surgery. We present our results of revision surgery for treatment of isolated fixed flexion deformity after knee replacement. METHODS: 32 patients had revision knee replacement for fixed flexion deformity and were included in this retrospective study. Minimum follow up period was 28 months. RESULTS: Two different surgical interventions had been done in these patients. Group 1 (15 patients) had revision of the femoral component, posterior capsular release and tibial component was not revised. Group 2 (18 Patients) had revision of both femoral and tibial components. One patient was included in both groups as she had both interventions. The extent of preoperative flexion deformity in group 1 was from 15 to 40 deg (mean 20.6 deg). Postoperative range of extension was 0 to 20 deg (mean 8.2 deg). In group 2, preoperative flexion deformity was 10 to 25 deg (mean 16.9 deg) and postoperative flexion deformity was 0 to 20 deg (mean 4.2 deg). The difference in improvement between the two groups was not statistically significant on Mann Whitney U test (two tailed p value 0.181) for non normal distribution. Improvement in Oxford knee score following surgery was only 1 point in both groups. CONCLUSION: Revision for isolated fixed flexion deformity leads to improvement in range of extension, but improvement in clinical score is marginal. The choice of preservation or revision of the tibial component did not make a significant difference to the outcome.


Assuntos
Artroplastia do Joelho , Prótese do Joelho , Osteoartrite do Joelho , Artroplastia do Joelho/efeitos adversos , Feminino , Humanos , Articulação do Joelho/diagnóstico por imagem , Articulação do Joelho/cirurgia , Osteoartrite do Joelho/cirurgia , Amplitude de Movimento Articular , Estudos Retrospectivos , Resultado do Tratamento
7.
Cureus ; 13(9): e18054, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34692283

RESUMO

Introduction A significant percentage of patients require re-revision surgery regardless of the demonstrated durable short- and mid-term clinical results using metaphyseal sleeves in revision total knee arthroplasty (TKA). The aim of this study was to identify the association between sleeve alignment and contact zones, with loosening in patients with revision TKA. Materials & Methods Of a series of 103 patients who underwent revision TKA, at a mean follow-up of eight years, six patients were re-revised for tibial loosening. These patients were compared with 19 unrevised control subjects in a 1:3 ratio. We calculated and compared the cumulative number of contact zones between the porous-coated part of the sleeve and bone on immediate postoperative X-rays between re-revised and unrevised patients. The main hypothesis was that neutral positioning and absolute circumferential contact between trabecular metaphyseal bone and porous-coated part of the sleeve would lead to a better outcome. Results The use of a conservative (nonparametric) approach indeed revealed better circumferential contact between trabecular metaphyseal bone and porous-coated part of the sleeve among the survivors, i.e., survivors: median (interquartile range [IQR]): 3 (2-4); failures: 3 (1-3), p = 0.003 (Mann-Whitney [MW] test). The difference was borderline significant for coronal alignment, i.e., survivors: median (IQR): -1 (-4 to 2); failures: 0 (-1 to 3), p = 0.0569 (MW test). Conclusion A circumferential bony contact of the metaphyseal sleeve would lead to better survival of the revision implant, whereas the degree of varus fixation did not seem to influence the longevity of the implant.

8.
J Cardiol Cases ; 23(3): 108-111, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33717373

RESUMO

Flush occlusions of coronary arteries present with multiple challenges during primary percutaneous coronary intervention (PPCI). We describe a case of anterior ST-elevation myocardial infarction in cardiogenic shock, where it was not possible to identify the origin of left anterior descending artery (LAD) as it was flush occluded and initial attempts to place a coronary guidewire in the LAD during PPCI were unsuccessful. After failed attempts with multiple guidewires, a combined pharmacological-mechanical approach resulted in successful timely revascularization and subsequent recovery of the patient. .

10.
J Arthroplasty ; 36(6): 2121-2125, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33509601

RESUMO

BACKGROUND: Hinge knee replacement is a salvage procedure with historically high failure and complication rates. We aim to analyze the use of an uncemented metaphyseal sleeve revision knee replacement in our unit-a third-generation rotating hinge knee prosthesis. This is the largest reported series of this implant with longest follow up. METHODS: We retrospectively identified 99 revision cases performed (2002-2018). In total, 67 of 99 (68%) cases were performed for aseptic etiology, whereas 32 of 99 (32%) cases were performed for infection. Clinical outcomes were assessed using the Oxford Knee Score, survivorship analysis, and incidence of revision/reoperations. Mean follow-up was 7 years (range 1.5-18). RESULTS: At follow-up, the mean Oxford Knee Score had improved from 10 points to 25 points. At mean 7 years of follow up, 18 of 99 cases had undergone revision giving a survivorship of 81% (90% aseptic). In total, 10 of 18 cases were performed for infection (10%) and 9 of 18 cases were performed for aseptic reasons (9%), of which 5 were for patella resurfacing (2 revision), 2 for failure of bony ingrowth, and 1 for fracture. Twenty-six patients (26%) had complications postoperatively, with patella disorders and reduced range of movement the most common. Patients who did not undergo patella resurfacing were significantly more likely to need revision of any cause (P = .01). CONCLUSION: This is the largest study of this prosthesis with longest follow-up. It demonstrates good survivorship and improvement in knee pain. Those with infection are at greatest risk of revision. Significant numbers have patella dysfunction/anterior knee symptoms therefore patella resurfacing should be considered when using this implant. LEVEL OF EVIDENCE: IV.


Assuntos
Artroplastia do Joelho , Prótese do Joelho , Seguimentos , Humanos , Articulação do Joelho/cirurgia , Desenho de Prótese , Falha de Prótese , Reoperação , Estudos Retrospectivos , Resultado do Tratamento
12.
Cardiovasc Drugs Ther ; 35(3): 427-440, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-32918656

RESUMO

Lopinavir-ritonavir combination is being used for the treatment of SARS-CoV-2 infection. A low dose of ritonavir is added to other protease inhibitors to take advantage of potent inhibition of cytochrome (CYP) P450 3A4, thereby significantly increasing the plasma concentration of coadministered lopinavir. Ritonavir also inhibits CYP2D6 and induces CYP2B6, CYP2C19, CYP2C9, and CYP1A2. This potent, time-dependent interference of major hepatic drug-metabolizing enzymes by ritonavir leads to several clinically important drug-drug interactions. A number of patients presenting with acute coronary syndrome and acute heart failure may have SARS-CoV-2 infection simultaneously. Lopinavir-ritonavir is added to their prescription of multiple cardiac medications leading to potential drug-drug interactions. Many cardiology, pulmonology, and intensivist physicians have never been exposed to clinical scenarios requiring co-prescription of cardiac and antiviral therapies. Therefore, it is essential to enumerate these drug-drug interactions, to avoid any serious drug toxicity, to consider alternate and safer drugs, and to ensure better patient care.


Assuntos
Tratamento Farmacológico da COVID-19 , Cardiopatias/tratamento farmacológico , Lopinavir/administração & dosagem , Ritonavir/administração & dosagem , SARS-CoV-2 , Anticoagulantes/uso terapêutico , Interações Medicamentosas , Quimioterapia Combinada , Humanos , Hipolipemiantes/uso terapêutico , Inibidores da Agregação Plaquetária/uso terapêutico
13.
Acta Orthop Belg ; 87(4): 659-664, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35172433

RESUMO

BACKGROUND: Presence of an extra-articular deformity in the femur or tibia poses a challenge to the surgeon undertaking knee replacement procedure. The conundrum is whether to correct the deformity beforehand, or accept the deformity and compensate for this through placement of the implant. MATERIAL AND METHODS: This is a retro-spective study comprising six patients who had a knee replacement in the presence of an extra-articular deformity of the tibia treated at our centre. All six had the knee replacement without correction of deformity. The data evaluated included clinical outcome, mechanical axis correction, type of implant, and the use of any software / computer guidance.The deformity was managed through planning of tibial resection without the need for pre-operative deformity correction. RESULTS: Mean age was 66.5 years. Mean coronal plane deformity in the tibia was 8.6 degrees. The hip- knee-ankle improved from a mean 12.6 degrees to 4 degrees. Mean Oxford knee score improved from a mean of 19 to 33.6. CONCLUSION: Planning the tibial resection on the basis of mechanical axis of tibia allows correction of alignment without the need for preoperative correction.Correction of the deformity may not be needed if the maximum tibial resection is less than 15 mm.


Assuntos
Artroplastia do Joelho , Prótese do Joelho , Osteoartrite do Joelho , Idoso , Artroplastia do Joelho/métodos , Fêmur/cirurgia , Humanos , Articulação do Joelho/diagnóstico por imagem , Articulação do Joelho/cirurgia , Osteoartrite do Joelho/cirurgia , Tíbia/diagnóstico por imagem , Tíbia/cirurgia
14.
J Pharm Sci ; 110(3): 1054-1066, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33278412

RESUMO

In a companion paper, a two-step developability assessment is presented to rapidly evaluate low-cost formulations (multi-dose, aluminum-adjuvanted) for new subunit vaccine candidates. As a case study, a non-replicating rotavirus (NRRV) recombinant protein antigen P[4] was found to be destabilized by the vaccine preservative thimerosal, and this effect was mitigated by modification of the free cysteine (C173S). In this work, the mechanism(s) of thimerosal-P[4] protein interactions, along with subsequent effects on the P[4] protein's structural integrity, are determined. Reversible complexation of ethylmercury, a thimerosal degradation byproduct, with the single cysteine residue of P[4] protein is demonstrated by intact protein mass analysis and biophysical studies. A working mechanism involving a reversible S-Hg coordinate bond is presented based on the literature. This reaction increased the local backbone flexibility of P[4] within the helical region surrounding the cysteine residue and then caused more global destabilization, both as detected by HX-MS. These effects correlate with changes in antibody-P[4] binding parameters and alterations in P[4] conformational stability due to C173S modification. Epitope mapping by HX-MS demonstrated involvement of the same cysteine-containing helical region of P[4] in antibody-antigen binding. Future formulation challenges to develop low-cost, multi-dose formulations for new recombinant protein vaccine candidates are discussed.


Assuntos
Rotavirus , Timerosal , Antígenos Virais , Conservantes Farmacêuticos , Vacinas de Subunidades Antigênicas
15.
J Pharm Sci ; 110(3): 1042-1053, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33285182

RESUMO

A two-step developability assessment workflow is described to screen variants of recombinant protein antigens under various formulation conditions to rapidly identify stable, aluminum-adjuvanted, multi-dose vaccine candidates. For proof-of-concept, a series of sequence variants of the recombinant non-replicating rotavirus (NRRV) P[8] protein antigen (produced in Komagataella phaffii) were compared in terms of primary structure, post-translational modifications, antibody binding, conformational stability, relative solubility and preservative compatibility. Based on these results, promising P[8] variants were down-selected and the impact of key formulation conditions on storage stability was examined (e.g., presence or absence of the aluminum-adjuvant Alhydrogel and the preservative thimerosal) as measured by differential scanning calorimetry (DSC) and antibody binding assays. Good correlations between rapidly-generated developability screening data and storage stability profiles (12 weeks at various temperatures) were observed for aluminum-adsorbed P[8] antigens. These findings were extended and confirmed using variants of a second NRRV antigen, P[4]. These case-study results with P[8] and P[4] NRRV variants are discussed in terms of using this vaccine formulation developability workflow to better inform and optimize formulation design with a wide variety of recombinant protein antigens, with the long-term goal of rapidly and cost-efficiently identifying low-cost vaccine formulations for use in low and middle income countries.


Assuntos
Vacinas contra Rotavirus , Rotavirus , Antígenos , Proteínas Recombinantes , Saccharomycetales
17.
Postgrad Med J ; 96(1137): 412-416, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32527756

RESUMO

Coronavirus infection outbreaks have occurred frequently in the last two decades and have led to significant mortality. Despite the focus on reducing mortality by preventing the spread of the virus, patients have died due to several other complications of the illness. The understanding of pathological mechanisms and their implications is continuously evolving. A number of symptoms occur in these patients due to the involvement of various endocrine glands. These clinical presentations went largely unnoticed during the first outbreak of severe acute respiratory syndrome (SARS) in 2002-2003. A few of these derangements continued during the convalescence phase and sometimes occurred after recovery. Similar pathological and biochemical changes are being reported with the novel coronavirus disease outbreak in 2020. In this review, we focus on these endocrine changes that have been reported in both SARS coronavirus and SARS coronavirus-2. As we battle the pandemic, it becomes imperative to address these underlying endocrine disturbances that are contributing towards or predicting mortality of these patients.


Assuntos
Doenças das Glândulas Suprarrenais/fisiopatologia , Betacoronavirus/fisiologia , Infecções por Coronavirus/fisiopatologia , Diabetes Mellitus/fisiopatologia , Pandemias , Pneumonia Viral/fisiopatologia , Síndrome Respiratória Aguda Grave/fisiopatologia , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/fisiologia , Doenças das Glândulas Suprarrenais/metabolismo , Doenças das Glândulas Suprarrenais/virologia , COVID-19 , Infecções por Coronavirus/metabolismo , Infecções por Coronavirus/virologia , Diabetes Mellitus/virologia , Humanos , Hiperglicemia , Pneumonia Viral/metabolismo , Pneumonia Viral/virologia , Guias de Prática Clínica como Assunto , SARS-CoV-2 , Síndrome Respiratória Aguda Grave/metabolismo , Síndrome Respiratória Aguda Grave/virologia
18.
J Pharm Sci ; 109(1): 394-406, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31400346

RESUMO

In a companion paper, the structural integrity, conformational stability, and degradation mechanisms of 3 recombinant fusion-protein antigens comprising a non-replicating rotavirus (NRRV) vaccine candidate (currently being evaluated in early-stage clinical trials) are described. In this work, we focus on the aggregation propensity of the 3 NRRV antigens coupled to formulation development studies to identify common frozen bulk candidate formulations. The P2-VP8-P[8] antigen was most susceptible to shaking and freeze-thaw-induced aggregation and particle formation. Each NRRV antigen formed aggregates with structurally altered protein (with exposed apolar regions and intermolecular ß-sheet) and dimers containing a non-native disulfide bond. From excipient screening studies with P2-VP8-P[8], sugars or polyols (e.g., sucrose, trehalose, mannitol, sorbitol) and various detergents (e.g., Pluronic F-68, polysorbate 20 and 80, PEG-3350) were identified as stabilizers against aggregation. By combining promising additives, candidate bulk formulations were optimized to not only minimize agitation-induced aggregation, but also particle formation due to freeze-thaw stress of P2-VP8-P[8] antigen. Owing to limited material availability, stabilization of the P2-VP8-P[4] and P2-VP8-P[6] was confirmed with the lead candidate P2-VP8-P[8] formulations. The optimization of these bulk NRRV candidate formulations is discussed in the context of subsequent drug product formulations in the presence of aluminum adjuvants.


Assuntos
Antígenos Virais/química , Excipientes/química , Agregados Proteicos , Proteínas Recombinantes de Fusão/química , Vacinas contra Rotavirus/química , Composição de Medicamentos , Estabilidade de Medicamentos , Armazenamento de Medicamentos , Drogas em Investigação/química , Congelamento , Tamanho da Partícula , Estabilidade Proteica , Vacinas de Subunidades Antigênicas/química
19.
J Pharm Sci ; 109(1): 380-393, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31400347

RESUMO

Although live attenuated Rotavirus (RV) vaccines are available globally to provide protection against enteric RV disease, efficacy is substantially lower in low- to middle-income settings leading to interest in alternative vaccines. One promising candidate is a trivalent nonreplicating RV vaccine, comprising 3 truncated RV VP8 subunit proteins fused to the P2 CD4+ epitope from tetanus toxin (P2-VP8-P[4/6/8]). A wide variety of analytical techniques were used to compare the physicochemical properties of these 3 recombinant fusion proteins. Various environmental stresses were used to evaluate antigen stability and elucidate degradation pathways. P2-VP8-P[4] and P2-VP8-P[6] displayed similar physical stability profiles as function of pH and temperature while P2-VP8-P[8] was relatively more stable. Forced degradation studies revealed similar chemical stability profiles with Met1 most susceptible to oxidation, the single Cys residue (at position 173/172) forming intermolecular disulfide bonds (P2-VP8-P[6] was most susceptible), and Asn7 undergoing the highest levels of deamidation. These results are visualized in a structural model of the nonreplicating RV antigens. The establishment of key structural attributes of each antigen, along with corresponding stability-indicating methods, have been applied to vaccine formulation development efforts (see companion paper), and will be utilized in future analytical comparability assessments.


Assuntos
Antígenos Virais/genética , Infecções por Rotavirus/prevenção & controle , Vacinas contra Rotavirus , Rotavirus/imunologia , Composição de Medicamentos , Estabilidade de Medicamentos , Escherichia coli/genética , Proteínas Recombinantes de Fusão/genética , Vacinas contra Rotavirus/química , Vacinas contra Rotavirus/genética , Vacinas contra Rotavirus/imunologia , Vacinas de Subunidades Antigênicas/química , Vacinas de Subunidades Antigênicas/genética , Vacinas de Subunidades Antigênicas/imunologia , Vacinas Sintéticas/química , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia , Proteínas não Estruturais Virais/genética
20.
J Pharm Sci ; 109(1): 476-487, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31589875

RESUMO

A nonreplicating rotavirus vaccine (NRRV) containing 3 recombinant fusion proteins adsorbed to aluminum adjuvant (Alhydrogel [AH]) is currently in clinical trials. The compatibility and stability of monovalent NRRV antigen with key components of a multidose vaccine formulation were examined using physicochemical and immunochemical methods. The extent and strength of antigen-adjuvant binding were diminished by increasing phosphate concentration, and acceptable levels were identified along with alternate buffering agents. Addition of the preservative thimerosal destabilized AH-adsorbed P2-VP8-P[8] as measured by differential scanning calorimetry. Over 3 months at 4°C, AH-adsorbed P2-VP8-P[8] was stable, whereas at 25°C and 37°C, instability was observed which was greatly accelerated by thimerosal addition. Loss of antibody binding (enzyme-linked immunosorbent assay) correlated with loss of structural integrity (differential scanning calorimetry, fluorescence spectroscopy) with concomitant nonnative disulfide bond formation (sodium dodecyl sulfate-polyacrylamide gel electrophoresis) and Asn deamidation (liquid chromatography -mass spectrometry peptide mapping). An alternative preservative (2-phenoxyethanol) showed similar antigen destabilization. Due to limited availability, only key assays were performed with monovalent P2-VP8-P[4] and P2-VP8-P[6] AH-adsorbed antigens, and varying levels of preservative incompatibility were observed. In summary, monovalent AH-adsorbed NRRV antigens stored at 4°C showed good stability without preservatives; however, future formulation development efforts are required to prepare a stable, preservative-containing, multidose NRRV formulation.


Assuntos
Adjuvantes Imunológicos/química , Hidróxido de Alumínio/química , Antígenos Virais/química , Conservantes Farmacêuticos/química , Vacinas contra Rotavirus/química , Timerosal/química , Proteínas Virais/química , Antígenos Virais/genética , Soluções Tampão , Composição de Medicamentos , Estabilidade de Medicamentos , Concentração de Íons de Hidrogênio , Conformação Proteica , Estabilidade Proteica , Vacinas contra Rotavirus/genética , Temperatura , Vacinas de Subunidades Antigênicas/química , Vacinas Sintéticas/química , Proteínas Virais/genética
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