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1.
J Family Med Prim Care ; 13(4): 1544-1549, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38827707

RESUMO

Background: Covid-19 was declared by the WHO as a pandemic in 2020; India was also severely affected. Diabetes, a major lifestyle disorder, has seen its prevalence rate rising in developing countries. India is home to the world's second-largest population of diabetes. Several studies have reported greater severity and mortality of Covid-19 in diabetic patients. Methodology: This was a hospital-based retrospective study done in a rural-based medical college in Kerala State. Data was collected using a semi-structured proforma and analysis was performed using Statistical Package for Social Sciences software version 25. The study was part of the STS research program of the Indian Council of Medical Research (ICMR). Results: There were 567 patients in the study. Those with pre-existing diabetes had a worse outcome compared to those with newly detected diabetes. The presence of CKD was associated with a poor outcome. Patients admitted to the ICU, and those on assisted ventilation also had a lower survival rate; within the subgroup, those on non-invasive ventilation had a better outcome. Conclusion: Mortality in Covid-19 is multifactorial. Those with diabetes have a poor outcome. Comorbidities have been reported to confer a high mortality rate in Covid-19 but this was not so in our study (except for CKD). Variability in outcome with respect to comorbidities and better outcomes in those who were non-invasively ventilated calls for more research to establish the relationship between pre-existing conditions and severity of disease. The use of non-invasive ventilation could also provide succor to resource-limited communities.

2.
Am J Dermatopathol ; 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38842316

RESUMO

BACKGROUND: Cellulitis is a significant public health burden and lacks a gold standard for diagnosis. Up to 1/3 of patients are incorrectly diagnosed. The skin biopsy has been proposed as the gold standard. OBJECTIVE: In this study, we evaluate the histopathologic characteristics and tissue culture positivity of biopsies in patients diagnosed with cellulitis seen by our inpatient dermatology consultation service. METHODS: This retrospective cohort study examined patients who were hospitalized with a skin and soft tissue infection at our institution between 2011 and 2020 and underwent a skin biopsy. RESULTS: Those with a positive tissue culture were more likely to die within 30 days compared with those with negative tissue cultures (26% vs. 6%, P = 0.048). Patients who died within 30 days were more likely to have acute interstitial inflammation as a feature on histopathology (38%, P = 0.03). LIMITATIONS: Single institutional design, unintentional exclusion of patients with organism-specific diagnosis, and selection for a medically complex patient population because of the nonroutine collection of biopsies. CONCLUSION: Positive tissue cultures and histopathology showing acute interstitial space inflammation on skin and soft tissue infection (SSTI) biopsies are associated with increased mortality and thus may serve as indicators of poor prognosis.

3.
Biotechnol Prog ; : e3483, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38856182

RESUMO

While high-throughput (HT) experimentation and mechanistic modeling have long been employed in chromatographic process development, it remains unclear how these techniques should be used in concert within development workflows. In this work, a process development workflow based on HT experiments and mechanistic modeling was constructed. The integration of HT and modeling approaches offers improved workflow efficiency and speed. This high-throughput in silico (HT-IS) workflow was employed to develop a Capto MMC polishing step for mAb aggregate removal. High-throughput batch isotherm data was first generated over a range of mobile phase conditions and a suite of analytics were employed. Parameters for the extended steric mass action (SMA) isotherm were regressed for the multicomponent system. Model validation was performed using the extended SMA isotherm in concert with the general rate model of chromatography using the CADET modeling software. Here, step elution profiles were predicted for eight RoboColumn runs across a range of ionic strength, pH, and load density. Optimized processes were generated through minimization of a complex objective function based on key process metrics. Processes were evaluated at lab-scale using two feedstocks, differing in composition. The results confirmed that both processes obtained high monomer yield (>85%) and removed ∼ 50 % $$ \sim 50\% $$ of aggregate species. Column simulations were then carried out to determine sensitivity to a wide range of process inputs. Elution buffer pH was found to be the most critical process parameter, followed by resin ionic capacity. Overall, this study demonstrated the utility of the HT-IS workflow for rapid process development and characterization.

4.
Sci Rep ; 14(1): 13266, 2024 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-38858464

RESUMO

The purpose of the study was to assess the effects of a novel technique involving facial stretching of the unaffected side along with a structured exercise for the affected side on facial symmetry and facial functions as compared to conventional exercise. A hospital-based parallel-group randomized trial was completed among patients with acute Bell's palsy in Mangalore, India. Participants were randomized to receive facial stretching and a structured exercise program (experimental group) or the conventional exercise regimen (conventional group). Primary outcomes were facial symmetry and voluntary movement; assessed by the Sunnybrook Facial Grading System (SFGS). Both regimens were given for 3 weeks, with baseline, 10th day, and 20th day assessments. Out of 31 participants screened, 24 were eligible and 12 participants each were assigned to experimental and conventional groups. Change scores revealed greater improvement in the SFGS score (p = 0.002) for the experimental group participants. Facial stretching and structured exercise program exhibited promising results in enhancing facial symmetry and function in acute Bell's palsy when compared to conventional exercise regimen.


Assuntos
Paralisia de Bell , Terapia por Exercício , Exercícios de Alongamento Muscular , Humanos , Paralisia de Bell/terapia , Paralisia de Bell/fisiopatologia , Paralisia de Bell/reabilitação , Masculino , Feminino , Adulto , Terapia por Exercício/métodos , Resultado do Tratamento , Pessoa de Meia-Idade , Método Simples-Cego , Face , Músculos Faciais/fisiopatologia , Adulto Jovem
5.
JAMA Dermatol ; 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38748440

RESUMO

This cohort study examines patients with drug reaction with eosinophilia and systemic symptoms who also have pustules.

6.
JAMA ; 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38744430

RESUMO

Importance: Effective weight loss interventions are needed for men with obesity. Objective: To determine whether an intervention that combined text messaging with financial incentives attained significant weight loss at the 12-month follow-up compared with the control group and whether an intervention of text messaging alone attained significant weight loss at the 12-month follow-up compared with the control group. Design, Setting, and Participants: An assessor-blinded randomized clinical trial conducted in Belfast, Bristol, and Glasgow areas in the UK. A total of 585 men with body mass index (BMI) of 30 or more were enrolled between July 2021 and May 2022. Final follow-up occurred June 2023. Interventions: Participants were randomly assigned to 12 months of behavioral focused text messages combined with financial incentives (n = 196), 12 months of behavioral focused text messages alone (n= 194), or a waiting list (control group; n= 195). The financial incentive consisted of a monetary reward that was lost if weight loss targets were not met. All participants received weight management information and a pedometer at baseline. Main Outcomes and Measures: The 2 primary comparisons were the 12-month comparison of within-participant weight change between the text messaging with financial incentive group and the control group and the comparison between the text messaging alone group and the control group (minimum clinically important difference, 3%). The P value defined for statistical significance was P < .025 for each comparison. Results: Of the 585 men (mean [SD] age, 50.7 [13.3] years; mean weight, 118.5 [19.9] kg; mean BMI, 37.7 [5.7]; 525 [90%] White), 227 (39%) lived in postal code areas with lower socioeconomic status, and 426 (73%) completed the 12-month follow-up. At the 12-month follow-up, compared with the control group, the mean percent weight change was significantly greater in the text messaging with financial incentive group (mean difference, -3.2%; 97.5% CI, -4.6% to -1.9%; P < .001) but was not significantly greater in the text messaging alone group (mean difference, -1.4%; 97.5% CI, -2.9% to 0.0, P = .05). The mean (SD) weight changes were -5.7 (7.4) kg for the text messaging with financial incentives group, -3.0 (7.5) kg for the text messaging alone group, and -1.5 (6.6) kg for the control group. The 12-month mean (SD) percentage weight changes from baseline were -4.8% (6.1%) for the text messaging with financial incentives group, -2.7% (6.3%) for text messaging alone group, and -1.3% (5.5%) for the control group. Of 366 adverse events reported, the most common were infections (83 [23%]). Of the 23 serious adverse events (6.3%), 12 (52%) occurred in the text messaging with financial incentives group, 5 (22%) in the texts messaging alone group, and 6 (26%) in the control group. None were considered related to participating in a trial group. Conclusion and Relevance: Among men with obesity, an intervention with text messaging with financial incentive significantly improved weight loss compared with a control group, whereas text messaging alone was not significantly better than the control condition. These findings support text messaging combined with financial incentives to attain weight loss in men with obesity. Trial Registration: isrctn.org Identifier: ISRCTN91974895.

8.
Arch Dermatol Res ; 316(6): 279, 2024 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-38796524

RESUMO

Symmetrical drug-related intertriginous and flexural exanthema (SDRIFE) is classically considered a low-risk, self-limiting eruption lacking systemic manifestations and sparing facial and mucosal areas. We present 7 inpatients meeting diagnostic criteria for SDRIFE with concomitant systemic manifestations ± high-risk facial involvement acutely after antibiotic exposure (mean latency 6.71 days). These cases deviate from classic, self-limited SDRIFE and represent a unique phenotype of SDRIFE, characterized by coexisting extracutaneous manifestations. Onset of systemic stigmata coincided with or preceded cutaneous involvement in 4 and 3 patients, respectively. All patients developed peripheral eosinophilia and 6 patients had ≥ 2 extracutaneous systems involved. Facial involvement, a high-risk feature associated with severe cutaneous adverse reactions but atypical in classic SDRIFE, occurred in 4 cases. Patients had favorable clinical outcomes following drug cessation and treatment with 4-6 week corticosteroid tapers. We suggest that baseline labs be considered in hospitalized patients with antibiotic-induced SDRIFE. These patients may also necessitate systemic therapy given extracutaneous involvement, deviating from standard SDRIFE treatment with drug cessation alone.


Assuntos
Antibacterianos , Toxidermias , Exantema , Fenótipo , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Exantema/induzido quimicamente , Exantema/diagnóstico , Antibacterianos/efeitos adversos , Toxidermias/etiologia , Toxidermias/diagnóstico , Toxidermias/patologia , Idoso , Adulto , Hospitalização/estatística & dados numéricos , Eosinofilia/diagnóstico , Eosinofilia/induzido quimicamente
9.
Pers Soc Psychol Bull ; : 1461672241238303, 2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38613365

RESUMO

As autonomous technology emerges, new variations in old questions arise. When autonomous technologies cause harm, who is to blame? The current studies compare reactions toward harms caused by human-controlled vehicles (HCVs) or human soldiers (HSs) to identical harms by autonomous vehicles (AVs) or autonomous robot soldiers. Drivers of HCVs, or HSs, were blamed more than mere users of AVs or HSs who outsourced their duties to ARSs. However, as human drivers/soldiers became less involved in (or were unaware of the preprogramming that led to) the harm, blame was redirected toward other entities (i.e., manufacturers and the tech company's executives), showing the opposite pattern as human drivers/soldiers. Results were robust to how blame was measured (i.e., degrees of blame versus apportionment of total blame). Overall, this research furthers the blame literature, raising questions about why, how (much), and to whom blame is assigned when multiple agents are potentially culpable.

10.
J Mater Chem B ; 12(18): 4375-4388, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38477350

RESUMO

Hydrogel-forming microneedles (HF-MNs) are composed of unique cross-linked polymers that are devoid of the active pharmaceutical ingredient (API) within the microneedle array. Instead, the API is housed in a reservoir affixed on the top of the baseplate of the HF-MNs. To date, various types of drug-reservoirs and multiple solubility-enhancing approaches have been employed to deliver hydrophobic molecules combined with HF-MNs. These strategies are not without drawbacks, as they require multiple manufacturing steps, from solubility enhancement to reservoir production. However, this current study challenges this trend and focuses on the delivery of the hydrophobic antibiotic rifampicin using SmartFilm-technology as a solubility-enhancing strategy. In contrast to previous techniques, smart drug-reservoirs (SmartReservoirs) for hydrophobic compounds can be manufactured using a one step process. In this study, HF-MNs and three different concentrations of rifampicin SmartFilms (SFs) were produced. Following this, both HF-MNs and SFs were fully characterised regarding their physicochemical and mechanical properties, morphology, Raman surface mapping, the interaction with the cellulose matrix and maintenance of the loaded drug in the amorphous form. In addition, their drug loading and transdermal permeation efficacy were studied. The resulting SFs showed that the API was intact inside the cellulose matrix within the SFs, with the majority of the drug in the amorphous state. SFs alone demonstrated no transdermal penetration and less than 20 ± 4 µg of rifampicin deposited in the skin layers. In contrast, the transdermal permeation profile using SFs combined with HF-MNs (i.e. SmartReservoirs) demonstrated a 4-fold increase in rifampicin deposition (80 ± 7 µg) in the skin layers and a permeation of approx. 500 ± 22 µg. Results therefore illustrate that SFs can be viewed as novel drug-reservoirs (i.e. SmartReservoirs) for HF-MNs, achieving highly efficient loading and diffusion properties through the hydrogel matrix.


Assuntos
Administração Cutânea , Sistemas de Liberação de Medicamentos , Hidrogéis , Agulhas , Rifampina , Rifampina/administração & dosagem , Rifampina/química , Hidrogéis/química , Animais , Pele/metabolismo , Absorção Cutânea , Interações Hidrofóbicas e Hidrofílicas
11.
Biotechnol Prog ; : e3454, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38539261

RESUMO

Precipitation during the viral inactivation, neutralization and depth filtration step of a monoclonal antibody (mAb) purification process can provide quantifiable and potentially significant impurity reduction. However, robust commercial implementation of this unit operation is limited due to the lack of a representative scale-down model to characterize the removal of impurities. The objective of this work is to compare isoelectric impurity precipitation behavior for a monoclonal antibody product across scales, from benchtop to pilot manufacturing. Scaling parameters such as agitation and vessel geometry were investigated, with the precipitate amount and particle size distribution (PSD) characterized via turbidity and flow imaging microscopy. Qualitative analysis of the data shows that maintaining a consistent energy dissipation rate (EDR) could be used for approximate scaling of vessel geometry and agitator speeds in the absence of more detailed simulation. For a more rigorous approach, however, agitation was simulated via computational fluid dynamics (CFD) and these results were applied alongside a population balance model to simulate the trajectory of the size distribution of precipitate. CFD results were analyzed within a framework of a two-compartment mixing model comprising regions of high- and low-energy agitation, with material exchange between the two. Rate terms accounting for particle formation, growth and breakage within each region were defined, accounting for dependence on turbulence. This bifurcated model was successful in capturing the variability in particle sizes over time across scales. Such an approach enhances the mechanistic understanding of impurity precipitation and provides additional tools for model-assisted prediction for process scaling.

15.
Clin Dermatol ; 42(3): 317-318, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38401699

RESUMO

In the age of increasing transparency, dermatologists may encounter requests from patients to alter or withhold key medical information from their electronic medical records. Per the Health Insurance Portability and Accountability Act, patients have the right to view their medical record and request amendments; however, the physician is the final decision maker on what information should be included in the chart. It is integral that medically necessary information is included in the chart in accordance with the principle of beneficence and nonmaleficence. Withholding medically pertinent history may cause harm to the patient. Navigating such challenging situations while maintaining transparency requires a thorough understanding of the patient's dilemma. This contribution provides a framework by applying multiple ethical principles and will empower dermatologists to navigate such requests.


Assuntos
Registros Eletrônicos de Saúde , Humanos , Registros Eletrônicos de Saúde/ética , Dermatologia/ética , Estados Unidos , Relações Médico-Paciente/ética , Health Insurance Portability and Accountability Act , Beneficência , Ética Médica
16.
Front Med (Lausanne) ; 11: 1334718, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38362536

RESUMO

Immune checkpoint inhibitor (ICI) use has been associated with numerous autoimmune side effects, known as immune related adverse events (irAEs). Cutaneous irAEs are common and affect up to 50% of patients treated with ICIs. There have been an increasing number of cases reported in the literature regarding ICI-induced subacute cutaneous lupus erythematosus (SCLE). ICI-induced SCLE is important to recognize as it can result in a delayed and/or prolonged skin reaction despite treatment discontinuation. We describe a patient with gastro-esophageal adenocarcinoma who developed SCLE following one cycle of nivolumab treatment. A 75-year-old man presented to our clinic with a new photo-distributed rash composed of oval scaly pink papules and plaques involving his chest and arms. Despite treatment with topical corticosteroids, he presented to the emergency department 1 week later with worsening rash. Skin biopsy showed vacuolar interface pattern, along with superficial perivascular lymphocytic infiltrate, consistent with a drug eruption. The clinicopathological presentation was consistent with ICI-induced SCLE. Nivolumab treatment was discontinued due to the severity of the rash. The rash remitted with systemic corticosteroids, high potency topical steroids, and hydroxychloroquine. Unfortunately, the patient developed intraperitoneal metastatic disease, and was enrolled in hospice care. In this paper, we highlight the importance of early identification and treatment of this irAE. A review of the literature, including a discussion on the management of ICI-induced SCLE is also provided.

17.
NeuroRehabilitation ; 54(2): 237-244, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38277311

RESUMO

BACKGROUND: In children with cerebral palsy (CP), fine motor skills limit forearm supination and active extension of the elbow, wrist, or fingers. Therapeutic interventions focusing on improving the ranges at these joints while facilitating active movements are the key to augmenting fine motor skills. OBJECTIVE: This pilot study examines if children with CP (with UE involvement) exposed to the Novel Hand Rehabilitation (NHR) Board will demonstrate 1) changes in spasticity and passive ROM of forearm and wrist/finger muscles, and 2) improvement in fine motor abilities. METHODS: The forearm and wrist/fingers of children with spastic CP (N = 15; M = 7, F = 8) aged 49-72 months (65.33±6.355 months) were positioned on the NHR board till their tolerance limit or a minimum duration of 30 minutes. The outcome measures, i.e., spasticity (Modified Ashworth Scale), passive range of motion (PROM) of wrist and fingers, and fine motor skills (PDMS-2 - Fine motor scale), were recorded. RESULTS: The spasticity of forearm pronators (0.001) and wrist flexors (0.008) reduced significantly, but not in wrist extensors. Post-intervention improvements in wrist extension (p = 0.005) and ulnar deviation ROM (p = 0.007) were significant. In thumb, changes were non-significant for the CMC flexion, but extension (0.003) and abduction (0.001) as well as MCP extension (0.004) were significant. The post-intervention MCP extension ROM for the 2nd (0.001), 3rd (0.007), and 4th fingers (0.014) were also substantial, but not for PIP and DIP joints. The post-intervention percentage change in the Grasping and Visual-motor integration subtests of PDMS-2 was 11.03% (p = 0.002) and 5.09% (p = 0.001) respectively. CONCLUSION: The immediate effects on fine motor skills in children with CP after the NHR board application were positive and encouraging. Hence, the NHR board can be recommended as an intervention to improve the fine motor abilities of children with CP.


Assuntos
Paralisia Cerebral , Criança , Humanos , Projetos Piloto , Paralisia Cerebral/reabilitação , Destreza Motora , Extremidade Superior , Mãos , Espasticidade Muscular/tratamento farmacológico
18.
Transplant Proc ; 56(1): 97-104, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38216361

RESUMO

AIMS AND BACKGROUND: To describe the prevalence of IgA deposits (IgAD) in renal allografts in a cohort of renal transplant recipients and to analyze their management strategies and histopathology. To assess graft function and proteinuria after 1 year of follow-up. MATERIALS AND METHODS: A prospective longitudinal follow-up study was carried out in VPS Lakeshore Hospital and Research Centre, Kochi, Kerala, over a period of 5 years (July 2015 to June 2020). Kidney transplant recipients with allograft biopsies that reported IgAD on immunofluorescence were included in the study. Light microscopy and immunofluorescence studies were performed. Mesangial hypercellularity (M); segmental glomerulosclerosis (S); endocapillary hypercellularity (E); tubular atrophy/interstitial fibrosis (T); crescents (C) (MEST-C) Scoring was done in patients with pathogenic IgAD. Treatment strategies included increased baseline steroid dosage, rituximab administration, and plasma exchange. Clinical details and management strategies were analyzed, and patients were followed up for 1 year after diagnosis. Changes in graft function (S. Creatinine) and proteinuria (Urine Protein/Creatinine ratio) were analyzed. Clinico-pathologic correlation with the MEST-C scores was also done. RESULTS: Out of 1036 kidney transplants done in the study period, 760 graft biopsies were performed. Sixty-four cases had post-transplant deposition of IgA (8%). The mean age was 45 ± 11.25SD years. The study had 51 men and 13 women. Induction immunosuppression comprised rabbit antithymocyte globulin in 29 (45%) patients and basiliximab in 35 (54%). Maintenance immunosuppression in all comprised tacrolimus, mycophenolate mofetil, and steroids. There were 2 groups: group A (pathogenic IgAD) and group B (incidental IgAD). Group A had 46 cases (71.9%), out of which 8 had "active" IgA nephropathy (endocapillary proliferation, crescents, and IgA vasculitis), and 38 had "inactive" IgAD. In patients with active deposits, 3 had cellular crescents (18%, 30%, and 23%), all 8 had endocapillary proliferation, and 2 had vasculitis. Group B had 18 cases (28.1%), comprising T cell-mediated rejections (5), antibody-mediated rejection (8), BK virus nephropathy (1), and interstitial fibrosis and tubular atrophy (4). In group A, 22 (47.8%) presented with graft dysfunction, 8 (17.3%) with isolated proteinuria, and 14 (30.4%) patients presented with a combination. Two (4.3%) patients had neither. Fourteen (30.4%) patients presented within 1 month of renal transplant. In patients of group A, at the end of 1 year of treatment, the mean S. Creatinine reduced to 1.68 mg/dL from 1.84 mg/dL, and the mean protein/creatinine ratio reduced from 1.2 to 0.5 (±1.17). In patients with "active IgA" lesions, at the end of 1 year of treatment, the mean S. Creatinine increased slightly to 1.68 mg/dL (±0.47SD) from 1.48 mg/dL (±0.52SD), and the mean protein/creatinine ratio reduced from 2.32 (±1.56SD) to 1.05 (±1.70SD). In the 16 patients with IgAD and proteinuria, at the end of 1 year of treatment, the mean S. Creatinine decreased to 1.41 ± 0.32 SD mg/dL from 1.47±0.37SD mg/dL and the mean protein/creatinine ratio reduced from 1.12 ± 1.31 SD to 0.39±0.75 SD. In the remaining 22 patients with acute tubular injury, at the end of 1 year, the mean S. Creatinine decreased to 1.920.32 SD mg/dL from 2.10.8SD mg/dL, and the mean protein/creatinine ratio reduced from 1.1 ± 1.31 SD to 0.66 ± 1.45 SD. In the MEST-C scoring analysis, all scores were 0 in 20 (43.4%) biopsies, only M1 score in 11 (23.9%) biopsies, only E1 score in 10 biopsies (21.7%), S1 in 13 (28.2%) cases. CONCLUSION: Immunoglobulin A deposits occur commonly after transplant; these may represent recurrence, de novo IgA, or donor-derived IgAD. Although commonly benign, some may cause significant graft dysfunction and graft loss. IgAD can present as varying combinations of graft dysfunction and proteinuria. Active IgA pathologies may occur early in the post-transplant course, may have significant graft dysfunction, and need proactive management. There is a correlation between segmental sclerosis and proteinuria. Evidence for the efficacy of Rituximab, plasma exchange, and prolonged courses of steroids is wanting; however, some benefits are possible. Long-term follow-up is essential.


Assuntos
Glomerulonefrite por IGA , Transplante de Rim , Masculino , Humanos , Feminino , Adulto , Pessoa de Meia-Idade , Transplante de Rim/efeitos adversos , Rituximab/uso terapêutico , Estudos Prospectivos , Creatinina , Seguimentos , Rim/patologia , Glomerulonefrite por IGA/patologia , Proteinúria/etiologia , Imunoglobulina A , Esteroides/uso terapêutico , Fibrose , Aloenxertos/patologia , Atrofia/patologia , Biópsia/efeitos adversos
19.
J Chromatogr A ; 1716: 464588, 2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38217959

RESUMO

Mechanistic modelling is a simulation tool which has been effectively applied in downstream bioprocessing to model resin chromatography. Membrane and fiber chromatography are newer approaches that offer higher rates of mass transfer and consequently higher flow rates and reduced processing times. This review describes the key considerations in the development of mechanistic models for these unit operations. Mass transfer is less complex than in resin columns, but internal housing volumes can make modelling difficult, particularly for laboratory-scale devices. Flow paths are often non-linear and the dead volume is often a larger fraction of the overall volume, which may require more complex hydrodynamic models to capture residence time distributions accurately. In this respect, the combination of computational fluid dynamics with appropriate protein binding models is emerging as an ideal approach.


Assuntos
Cromatografia , Membranas Artificiais , Cromatografia/métodos , Simulação por Computador , Hidrodinâmica
20.
Biotechnol Bioeng ; 121(4): 1284-1297, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38240126

RESUMO

Product association of host-cell proteins (HCPs) to monoclonal antibodies (mAbs) is widely regarded as a mechanism that can enable HCP persistence through multiple purification steps and even into the final drug substance. Discussion of this mechanism often implies that the existence or extent of persistence is directly related to the strength of binding but actual measurements of the binding affinity of such interactions remain sparse. Two separate avenues of investigation of HCP-mAb binding are reported here. One is the measurement of the affinity of binding of individual, commonly persistent Chinese hamster ovary (CHO) HCPs to each of a set of mAbs, and the other uses quantitative proteomic measurements to assess binding of HCPs in a null CHO harvested cell culture fluid (HCCF) to mAbs produced in the same cell line. The individual HCP measurements show that the binding affinities of individual HCPs to different mAbs can vary appreciably but are rarely very high, with only weak pH dependence. The measurements on the null HCCF allow estimation of individual HCP-mAb affinities; these are typically weaker than those seen in affinity measurements on isolated HCPs. Instead, the extent of binding appears correlated with the initial abundance of individual HCPs in the HCCF and the forms of the HCPs in the solution, i.e., whether HCPs are present as free molecules or as parts of large aggregates. Separate protein A chromatography experiments performed by feeding different fractions of a mAb-containing HCCF obtained by size-exclusion chromatography (SEC) showed clear differences in the number and identity of HCPs found in the protein A eluate. These results indicate a significant role for HCP-mAb association in determining HCP persistence through protein A chromatography, presumably through binding of HCP-mAb complexes to the resin. Overall, the results illustrate the importance of considering more fully the biophysical context of HCP-product association in assessing the factors that may affect the phenomenon and determine its implications. Knowledge of the abundances and the forms of individual or aggregated HCPs in HCCF are particularly significant, emphasizing the integration of upstream and downstream bioprocessing and the importance of understanding the collective properties of HCPs in addition to just the biophysical properties of individual HCPs.


Assuntos
Anticorpos Monoclonais , Proteômica , Cricetinae , Animais , Cricetulus , Proteômica/métodos , Células CHO , Anticorpos Monoclonais/química , Cromatografia em Gel , Proteína Estafilocócica A/química
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