Decreased breadth of the antibody response to the spike protein of SARS-CoV-2 after repeated vaccination.

Introduction: The rapid development of vaccines to prevent COVID-19 has raised the need to compare the capacity of different vaccines in terms of developing a protective humoral response. Previous studies have shown inconsistent results in this area, highlighting the importance of further research to evaluate the efficacy of different vaccines. Methods: This study utilized a highly sensitive and reliable flow cytometry method to measure the titers of IgG1 isotype antibodies in the blood of healthy volunteers after receiving one or two doses of various vaccines administered in Spain. The method was also used to simultaneously measure the reactivity of antibodies to the S protein of the original Wuhan strain and variants B.1.1.7 (Alpha), B.1.617.2 (Delta), and B.1.617.1 (Kappa). Results: Significant differences were observed in the titer of anti-S antibodies produced after a first dose of the vaccines ChAdOx1 nCov-19/AstraZeneca, mRNA-1273/Moderna, BNT162b2/Pfizer-BioNTech, and Ad26.COV.S/Janssen. Furthermore, a relative reduction in the reactivity of the sera with the Alpha, Delta, and Kappa variants, compared to the Wuhan strain, was observed after the second boosting immunization. Discussion: The findings of this study provide a comparison of different vaccines in terms of anti-S antibody generation and cast doubts on the convenience of repeated immunization with the same S protein sequence. The multiplexed capacity of the flow cytometry method utilized in this study allowed for a comprehensive evaluation of the efficacy of various vaccines in generating a protective humoral response. Future research could focus on the implications of these findings for the development of effective COVID-19 vaccination strategies.

Alveolar bone level is not associated with vitamin D receptor gene polymorphism and bone density in mandible.

The objective of this study was to determine, using digital panoramic radiographs, whether the bone level at the alveolar crest is related to the mandibular bone density and/or to vitamin D receptor (VDR) gene polymorphisms. We analyzed 319 digital panoramic radiographs from the same number of patients. Alveolar bone level was expressed as percentage of root length. The mandibular cortical width index was calculated as a measure of mandibular bone density, and, in 72 randomly selected cases, the haplotype of the VDR gene (BsmL) was determined by polymerase chain reaction. Alveolar bone level was not related to the mandibular cortical width index (p = 0.568) or VDR gene expression (p = 0.575). Bone loss was greater in smokers than in non-smokers (p = 0.036), and the mandibular cortical width index was higher in males (p = 0.04), the older age group (p = 0.032), and in those with more teeth (p = 0.01). Multivariate analysis confirmed the association between these variables and alveolar bone loss. Alveolar bone loss showed no significant relationship with the mandibular bone density evaluated on digital panoramic radiographs or with VDR genotype (BsmL) in Caucasian females and males aged under 47 years.

Vaccine Type-, Age- and Past Infection-Dependence of the Humoral Response to SARS-CoV-2 Spike S Protein.

The emergence of COVID-19 has led to a worldwide challenge for the rapid development of vaccines. Several types of safe and effective vaccines have been available in a time frame never seen before. Now that several hundred million people have been vaccinated there is an opportunity to compare vaccines in terms of protection and immune response. Here, we have applied a highly sensitive multiplexed flow cytometry method to measure simultaneously IgM, IgG1 and IgA anti-spike protein antibodies generated in response to three vaccines: ChAdOx1 (Oxford-AstraZeneca), mRNA-1273 (Moderna), and BNT162b2 (Pfizer-BioNTech). We have found that mRNA vaccines (mRNA-1273 and BNT162b2) induce a stronger humoral response, both after the first and the second dose, than the adenovirus-based ChAdOx1 vaccine. We also found that, in the elderly, antibody titers negatively correlate with the age of the donor but, also, that antibody titers remain stable for at least 6 months after complete vaccination. Finally, we found that one dose of BNT162b2 is sufficient to induce the highest antibody titers in seropositive pre-vaccination donors. We hope these data will help to guide future decisions on vaccination strategies.

Effects of environmental stress on mRNA and protein expression levels of steroid 5alpha-Reductase isozymes in adult rat brain.

Environmental stress conditions are important factors in human health and should be considered in the development of appropriate health policies, since they have been associated with psychological disorders and even with death. A link between stress and changes in 3alpha,5alpha-reduced neurosteroids has been reported. Steroid 5alpha-Reductase (5alpha-R) is the rate-limiting enzyme in the biosynthesis of 3alpha,5alpha-reduced neurosteroids. Using reverse transcription-polymerase chain reaction and immunohistochemistry, 5alpha-R isozymes (5alpha-R1 and 5alpha-R2) mRNA and protein levels were detected in prefrontal cortex of male and female rats after they underwent environmental stresses, i.e., excessive heat, artificial light, and the sensation of immobility in a small space, similar to those found in common workplace situations. Results showed significantly higher 5alpha-R2 mRNA and protein levels in environmentally-stressed versus control rats. Interestingly, a sexual dimorphism in 5alpha-R1 mRNA and protein levels was observed after environmental stress, with an increase in males and a decrease in females. This fact might explain gender differences in the incidence of some type of minor depression.

Expression of steroid 5α-reductase isozymes in prostate of adult rats after environmental stress.

The elevated incidence of prostate cancer and benign prostatic hypertrophy is a cause of increasing public health concern in the Western world. The normal and pathological growth of the prostate are both dependent on stimulation by dihydrotestosterone, which is synthesized from circulating testosterone by two 5α-reductase (5α-R) isozymes, 5α-reductase type 1 (5α-R1) and 5α-reductase type 2 (5α-R2). Both isozymes have been implicated in prostate disease. We used quantitative RT-PCR and immunohistochemistry, respectively, to quantify mRNA and protein levels of 5α-R isozymes in the ventral prostate of adult rats under environmental stress conditions analogous to those found in some common workplace situations, i.e. artificial light, excessive heat, and the sensation of immobility in a small space. Transcription and expression levels of both 5α-R isozymes were significantly higher in environmentally stressed rats than in unstressed rats. Increased 5α-R isozyme levels may play a role in the development or maintenance of prostate disease. Further research is warranted to explore these effects of environmental stress on human health and their implications for environmental and occupational health policies.

Bisphenol A modifies the regulation exerted by testosterone on 5 α -reductase isozymes in ventral prostate of adult rats.

The development, growth, and function of the prostate gland depend on androgen stimulation. The primary androgen in prostate is 5α-dihydrotestosterone (DHT) which is synthesized from circulating testosterone (T) through the action of 5α-reductase (5α-R). Although 5α-R occurs as five isozymes, only 5α-R1 and 5α-R2 are physiologically involved in steroidogenesis. The endocrine disruptor bisphenol A (BPA) alters sexual organs, including the prostate. Our previous findings indicated that BPA decreased the expression of 5α-R1 and 5α-R2 in rat prostate but also circulating T. Thus, it is unclear whether BPA exerts this effect on 5α-R isozymes by reducing circulating T or by any other mechanism. In this study, we examine the effects of short-term exposure to BPA at doses below 25 µg/Kg/d and above 300 µg/Kg/d of the TDI on mRNA levels of 5α-R1 and 5α-R2 in prostate of adult castrated rats supplemented with T to achieve constant circulating T levels. mRNA levels were measured by absolute quantitative RT-PCR, T levels by RIA, and DHT levels by ELISA. Our results indicated that in castrated rats treated with T BPA at the two doses studied significantly decreased the mRNA levels of both 5α-R isozymes in a dose-dependent manner without modifications in circulating T.

Detection and Genotyping of Human Papillomavirus DNA in Formalin-Fixed Paraffin-Embedded Specimens with the HPV Direct Flow CHIP System.

The novel HPV Direct Flow CHIP commercial system for Human Papillomavirus (HPV) genotyping is based on rapid PCR and automatic reverse dot blot hybridization to genotype-specific probes, allowing the detection of 36 HPV genotypes. This study examined the performance of HPV Direct Flow CHIP in formalin-fixed paraffin-embedded (FFPE) samples (n= 99). Each sample was analyzed both by Direct PCR, using crude cell extracts without DNA purification, and by conventional PCR, using purified DNA. Pair-wise analysis of the results demonstrated strong concordance between the results obtained with the two protocols, although a slightly higher rate of multiple infections was detected by conventional PCR. In summary, HPV Direct Flow CHIP achieves effective HPV detection from FFPE samples with both Direct PCR and Conventional PCR protocols.

Glicoproteína P en leucocitos de sangre periférica de individuos sanos / Glycoprotein P in peripheral blood leukocytes of healthy individual

El objetivo de este trabajo fue estudiar la distribución de la expresión de la Gp-P y su ARNm en sangre periférica de una amplia población de sujetos sanos para identificar probables diferencias individuales. Para ello se estudiaron un total de 126 muestras sanguíneas mediantes inmunofluorescencia directa, por citometría de flujo, con el anticuerpo monoclonal JSB1 conjugado con FITC. Los parámetros a evaluar fueron el número de células positivas (por ciento POS) e incorporación media de fluorescencia específica (IMFE). Posteriormente, se estudió el ARNm del gen MDR1 por RT-PCR. Los resultados mostraron que en aproximadamente el 82 por ciento de los individuos estudiados, la IMFE presentó valores entre 10 y 25 en las tres subpoblaciones celulares de sangre periférica; en los linfocitos y monocitos, se observó además que un grupo de donantes, no superior al 10 por ciento, presentaron valores de IMFE menores de 10 y mayores de 25. Entre los subpoblaciones celulares, el por ciento POS más elevado correspondió a los linfocitos (t de student; p<0.001). Los resultados del estudio de ARNm del gen MDR1 por TR-PCR mostró correlación con los valores obtenidos por citometría del flujo. Se concluye que el estudio de la Glicoproteína P en el leucocitos de sangre periférica en una población de individuos sanos, pone de manifiesto la existencia de variabilidad individual en los niveles de expresión, lo que hace suponer un condicionamiento genético de control de los niveles de expresión basal de la Gp-P