The Effect of Feeding, Bilateral Parotidectomy, and Pilocarpine Treatment on Parotid Hormone Secretion in the Pig

The effect of feeding, bilateral parotidectomy, pilocarpine treatment, visual and olfactory, and masticatory stimuli on parotid hormone (PH) secretion is reported. Feeding a regular chow was shown to be a potent stimulus for PH secretion. The parotid endocrine system is highly sensitive to the eating stimulus, since a period of feeding lasting 30 sec is enough to cause a significant increase in PH secretion. The parotid glands are the principal source of PH as shown by the marked decrease in basal PH titer, and a virtual absence of response of PH to feeding in parotidectomized pigs. Pilocarpine administration provoked profuse salivation, but failed to increase significantly PH plasma titer. No significant increase in PH level occurred when visual and olfactory and masticatory stimuli were tested for 10 minutes. However, a chow meal given 30 minutes later, produced the typical PH response. Since an inverse relationship between dentinal fluid transport (DFT) and dental caries has been demonstrated, and that PH regulates DPT; it is suggested that eating, while providing substrate for the oral microbial flora, activates at the same time a systemic defense mechanism against dental decay by stimulating the release of PH, which in turn stimulates DFT. The mechanism of release of PH from the parotids may be a neuroendocrine reflex mediated through the hypothalamic-parotid gland endocrine axis

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

IL-3 induces B7.2 (CD86) expression and costimulatory activity in human eosinophils

Eosinophils in tissues are often present in intimate contact with T cells in allergic and parasitic diseases. Resting eosinophils do not express MHC class II proteins or costimulatory B7 molecules and fail to induce proliferation of T cells to Ags. IL-5 and GM-CSF induce MHC class II and B7 expression on eosinophils and have been reported in some studies to induce eosinophils to present Ag to T cells. The cytokine IL-3, like IL-5 and GM-CSF, is a survival and activating factor for eosinophils and the IL-3 receptor shares with the IL-5 and GM-CSF receptors a common signal transducing �-chain. IL-3-treated eosinophils expressed HLA-DR and B7.2, but not B7.1 on their surface and supported T cell proliferation in response to the superantigen toxic shock syndrome toxin 1, as well as the proliferation of HLA-DR-restricted tetanus toxoid (TT) and influenza hemagglutinin-specific T cell clones to antigenic peptides. This was inhibited by anti-B7.2 mAb. In contrast, IL-3-treated eosinophils were unable to present native TT Ag to either resting or TT-specific cloned T cells. In parallel experiments, eosinophils treated with IL-5 or GM-CSF were also found to present superantigen and antigenic peptides, but not native Ag, to T cells. These results suggest that eosinophils are deficient in Ag processing and that this deficiency is not overcome by cytokines that signal via the �-chain. Nevertheless, our findings suggest that eosinophils activated by IL-3 may contribute to T cell activation in allergic and parasitic diseases by presenting superantigens and peptides to T cells. The Journal of Immunology, 2001, 167: 6097–6104. At least two signals are required for T cell activation and proliferation. The first signal is the recognition by th

MODELO DE REGRESIÓN LINEAL MÚLTIPLE PARA DETERMINAR EL NIVEL DINÁMICO DE LOS POZOS EN LA CIUDAD DE CELAYA, GUANAJUATO

Los niveles en el acuífero del valle de Celaya, Guanajuato, están disminuyendo debido a la sobreexplotación y al crecimiento acelerado de la población a la cual por ley se tiene que brindar el servicio de agua potable, por lo que se hace necesario el establecimiento de modelos para pronosticar el mismo. El objetivo de este trabajo es generar un modelo de regresión lineal que ayude a determinar la tasa en que disminuye el nivel del acuífero en la Zona Urbana de Celaya. En el modelo se integran variables como son: nivel dinámico, abatimiento, caudal, capacidad específica y nivel estático. Para la generación del modelo se empleo la teoría de regresión lineal múltiple de mínimos cuadrados comparándose con otro generado por regresión Ridge, donde se elige aquella que tiene un mejor ajuste en base al valor mínimo del cuadrado medio del error. El modelo generado por regresión Ridge posee parámetros sesgados pero de menor varianza que mínimos cuadrados, lo cual brinda mayor certeza para la realización de pronósticos sobre el comportamiento de los niveles del acuífero en la Zona Urbana de Celaya.Acuífero, Nivel dinámico, nivel estático, regresión lineal múltiple, regresión Ridge.

Newborn screening for severe combined immunodeficiency in 11 screening programs in the United States.

ImportanceNewborn screening for severe combined immunodeficiency (SCID) using assays to detect T-cell receptor excision circles (TRECs) began in Wisconsin in 2008, and SCID was added to the national recommended uniform panel for newborn screened disorders in 2010. Currently 23 states, the District of Columbia, and the Navajo Nation conduct population-wide newborn screening for SCID. The incidence of SCID is estimated at 1 in 100,000 births.ObjectivesTo present data from a spectrum of SCID newborn screening programs, establish population-based incidence for SCID and other conditions with T-cell lymphopenia, and document early institution of effective treatments.DesignEpidemiological and retrospective observational study.SettingRepresentatives in states conducting SCID newborn screening were invited to submit their SCID screening algorithms, test performance data, and deidentified clinical and laboratory information regarding infants screened and cases with nonnormal results. Infants born from the start of each participating program from January 2008 through the most recent evaluable date prior to July 2013 were included. Representatives from 10 states plus the Navajo Area Indian Health Service contributed data from 3,030,083 newborns screened with a TREC test.Main outcomes and measuresInfants with SCID and other diagnoses of T-cell lymphopenia were classified. Incidence and, where possible, etiologies were determined. Interventions and survival were tracked.ResultsScreening detected 52 cases of typical SCID, leaky SCID, and Omenn syndrome, affecting 1 in 58,000 infants (95% CI, 1/46,000-1/80,000). Survival of SCID-affected infants through their diagnosis and immune reconstitution was 87% (45/52), 92% (45/49) for infants who received transplantation, enzyme replacement, and/or gene therapy. Additional interventions for SCID and non-SCID T-cell lymphopenia included immunoglobulin infusions, preventive antibiotics, and avoidance of live vaccines. Variations in definitions and follow-up practices influenced the rates of detection of non-SCID T-cell lymphopenia.Conclusions and relevanceNewborn screening in 11 programs in the United States identified SCID in 1 in 58,000 infants, with high survival. The usefulness of detection of non-SCID T-cell lymphopenias by the same screening remains to be determined