Humoral and cellular responses to repeated COVID-19 exposure in multiple sclerosis patients receiving B-cell depleting therapies: a single-center, one-year, prospective study.

Multiple sclerosis patients treated with anti-CD20 therapy (aCD20-MS) are considered especially vulnerable to complications from SARS-CoV-2 infection due to severe B-cell depletion with limited viral antigen-specific immunoglobulin production. Therefore, multiple vaccine doses as part of the primary vaccination series and booster updates have been recommended for this group of immunocompromised individuals. Even though much less studied than antibody-mediated humoral responses, T-cell responses play an important role against CoV-2 infection and are induced efficiently in vaccinated aCD20-MS patients. For individuals with such decoupled adaptive immunity, an understanding of the contribution of T-cell mediated immunity is essential to better assess protection against CoV-2 infection. Here, we present results from a prospective, single-center study for the assessment of humoral and cellular immune responses induced in aCD20-MS patients (203 donors/350 samples) compared to a healthy control group (43/146) after initial exposure to CoV-2 spike antigen and subsequent re-challenges. Low rates of seroconversion and RBD-hACE2 blocking activity were observed in aCD20-MS patients, even after multiple exposures (responders after 1st exposure = 17.5%; 2nd exposure = 29.3%). Regarding cellular immunity, an increase in the number of spike-specific monofunctional IFNγ+-, IL-2+-, and polyfunctional IFNγ+/IL-2+-secreting T-cells after 2nd exposure was found most noticeably in healthy controls. Nevertheless, a persistently higher T-cell response was detected in aCD20-MS patients compared to control individuals before and after re-exposure (mean fold increase in spike-specific IFNγ+-, IL-2+-, and IFNγ+/IL-2+-T cells before re-exposure = 3.9X, 3.6X, 3.5X/P< 0.001; after = 3.2X, 1.4X, 2.2X/P = 0.002, P = 0.05, P = 0.004). Moreover, cellular responses against sublineage BA.2 of the currently circulating omicron variant were maintained, to a similar degree, in both groups (15-30% T-cell response drop compared to ancestral). Overall, these results highlight the potential for a severely impaired humoral response in aCD20-MS patients even after multiple exposures, while still generating a strong T-cell response. Evaluating both humoral and cellular responses in vaccinated or infected MS patients on B-cell depletion therapy is essential to better assess individual correlations of immune protection and has implications for the design of future vaccines and healthcare strategies.

Maternal prepregnancy obesity and gestational diabetes influence on adverse perinatal outcomes.

Objective: Evaluate the influence of isolated and associated prepregnancy obesity and gestational diabetes mellitus (GDM) on adverse perinatal outcomes. Materials and methods: Cross-sectional observational study with women who delivered at a Brazilian Maternity Hospital, between August and December 2020. Data were collected by interview with application form, and medical records. Sample was stratified by body mass index (BMI) and GDM screening in four groups: no obesity (BMI < 30 kg/m2) no GDM - reference; isolated GDM; isolated obesity (BMI ≥ 30 kg/m2); and obesity with GDM. Preeclampsia (PE), cesarean section (CS), large-for-gestational-age (LGA) newborn and admission to neonatal intensive care unit (NICU) were analyzed by odds ratio (OR) adjusted for confounding factors, adopting 95% confidence interval (CI) and P < 0.05 statistically significant. Results: From 1,618 participants, isolated obesity group (233/14.40%) had high chance of PE (OR = 2.16; CI: 1.364-3.426; P = 0.001), isolated GDM group (190/11.74%) had high chance of CS (OR = 1.736; CI: 1.136-2.652; P = 0.011) and NICU admission (OR = 2.32; CI: 1.265-4.261; P = 0.007), and obesity with GDM group (121/7.48%) had high chance of PE (OR = 1.93; CI: 1.074-3.484; P = 0.028), CS (OR = 1.925; CI: 1.124-3.298; P = 0.017) and LGA newborn (OR = 1.81; CI: 1.027-3.204; P = 0.040), compared with reference (1,074/66.38%). Conclusion: Obesity and GDM enhances the chance of different negative outcomes, worsening this prognosis when associated.

A novel cysteine proteinase inhibitor from seeds of Enterolobium contortisiliquum and its effect on Callosobruchus maculatus larvae.

This study focused on the characterization of a novel cysteine proteinase inhibitor from Enterolobium contortisiliquum seeds targeting the inhibition of the growth of Callosobruchus maculatus larvae, an important cosmopolitan pest of the cowpea Vigna unguiculata during storage. The inhibitor was isolated by ion-exchange besides of size exclusion chromatography. EcCI molecular mass is 19,757 Da, composed of two polypeptide chains. It strongly inhibits papain (Kiapp 0.036 nM) and proteinases from the midguts of C. maculatus (80 µg mL-1, 60% inhibition). The inhibitory activity is reduced by 40% after a heat treatment at 100 °C for 2 h. The protein displayed noxious activity at 0.5% and 1% (w/w) when incorporated in artificial seeds, reducing larval mass in 87% and 92%, respectively. Treatment of C. maculatus larvae with conjugated EcCI-FIT and subsequent biodistribution resulted in high fluorescence intensity in midguts and markedly low intensity in malpighian tubules and fat body. Small amounts of labeled proteins were detected in larvae feces. The detection of high fluorescence in larvae midguts and low fluorescence in their feces indicate the retention of the FITC conjugated EcCI inhibitor in larvae midguts. These results demonstrate the potential of the natural protein from E. contortisiliquum to inhibit the development of C. maculatus.

Determination of total protein in hyperimmune serum samples by near-infrared spectrometry and multivariate calibration.

In the present work, the determination of the total protein concentration in hyperimmune serum samples was performed through a partial least-squares near-infrared (NIR-PLS) method. The method was based on the chemometric treatment of the NIR spectra of samples. The influences of spectra preprocessing and spectral window utilized in the construction of PLS model were studied. Models were built using reference data of 19 samples selected through the use of hierarchical cluster analysis (HCA) of NIR spectra of samples and another 24 samples were employed for external validation of the method. A model with better prediction capacity was obtained after whole spectra preprocessing by multiplicative scattering correction (MSC) algorithm and using data in the spectral range of 2158-2209nm. Under optimized conditions a RMSEP of 0.21gdl(-1) and a quality coefficient value (QC) of only 5.8% were obtained for the prediction of total protein content in the samples used for external validation. Also, a determination coefficient, r(2), of 0.97 was obtained in the correlation of predicted and reference data of samples situated in the validation set.

Development and validation of a HPLC-UV method for the determination in didanosine tablets.

A simple, rapid, sensitive and specific reversed-phase high performance liquid chromatographic method involving ultraviolet detection (HPLC-UV) was developed for analysis of didanosine in drug substance and formulated products, tablets. Chromatography was carried out on a pre-packed, Lichrospher 100 Rp-8 (5.0 microm, 250 mm x 4.0 mm) column using 0.01 M sodium acetate solution:methanol (85:15, v/v) adjusted to pH 6.5 with acetic acid as mobile phase at a flow rate of 1.5 ml/min and a 248 nm detection. Hypoxantine was confirmed as the main degradation product. The assay was linear over the concentration range of 50-150 microg/ml (R approximately 0.999). The method was validated for accuracy and precision.

Potential of the Lectin/Inhibitor Isolated from Crataeva tapia Bark (CrataBL) for Controlling Callosobruchus maculatus Larva Development.

Callosobruchus maculatus is an important predator of cowpeas. Due to infestation during storage, this insect affects the quality of seed and crop yield. This study aimed to investigate the effects of CrataBL, a multifunction protein isolated from Crataeva tapia bark, on C. maculatus larva development. The protein, which is stable even in extreme pH conditions, showed toxic activity, reducing the larval mass 45 and 70% at concentrations of 0.25 and 1.0% (w/w), respectively. Acting as an inhibitor, CrataBL decreased by 39% the activity of cysteine proteinases from larval gut. Conversely, the activity of serine proteinases was increased about 8-fold. The toxic properties of CrataBL may also be attributed to its capacity of binding to glycoproteins or glycosaminoglycans. Such binding interferes with larval metabolism, because CrataBL-FITC was found in the fat body, Malpighian tubules, and feces of larvae. These results demonstrate the potential of this protein for controlling larva development.