Being a deaf student in a face mask world: Survey data from Italian university students.

In response to the COVID-19 pandemic, universities made face masks mandatory during face-to-face classes and/or switched to virtual classes. Such situations pose a challenge for students with hearing loss as they generate listening conditions that make speech comprehension difficult. This study aimed to explore the listening difficulties perceived by Italian university students with hearing loss (HL) and typical hearing (TH) as well as their adoption of self-advocacy strategies . We measured listening difficulties as a function of teaching modality (face-to-face and virtual classes) and the type of face mask (opaque and transparent) worn by the lecturer. In face-to-face classes, the most challenging situations for HL students involved speech comprehension when groups of students were working simultaneously and lecturers talked and moved at the same time during their lessons. The use of transparent masks, compared to opaque one, by the lecturer did not reduce the perceived listening difficulties . In virtual classes, the greatest listening difficulties for HL students occurred when the lecturer's face was not visible or she/he did not use a microphone, while subtitles and sign language interpreters were speech comprehension facilitators. The TH group perceived the same situations as most challenging both in face-to-face and virtual classes, albeit to a lesser extent than the HL respondents. Despite most students demonstrated proactive self-advocacy strategies to improve speech comprehension, in some listening contexts inactive behaviors still persisted. To reduce the listening difficulties posed by pandemic measures, training to improve students' self-advocacy strategies and educators' hearing loss awareness behaviors, as well as the development of interventions aimed at reducing noise in classes, are essential to improve speech perception among HL students.

Regulatory cross-talk of mouse liver polyamine and methionine metabolic pathways: a systemic approach to its physiopathological consequences.

Both polyamines and methionine derivatives are nitrogen compounds directly related to the regulation of gene expression. In silico predictions and experimental evidence suggest a cross-talk between polyamine and methionine metabolism in mammalian tissues. Since liver is the major organ that controls nitrogen metabolism of the whole organism, it is the best tissue to further test this hypothesis in vivo. In this work, we studied the effects of the chronic administration of a methionine-supplemented diet (0.5% Met in drinking water for 5 months) on the liver of mice (designated as MET-mice). Metabolic and proteomic approaches were performed and the data obtained were subjected to biocomputational analysis. Results showed that a supplemental methionine intake can indeed regulate biogenic amine metabolism in an in vivo model by multiple mechanisms including metabolic regulation and specific gene demethylation. Furthermore, putative systemic effects were investigated by molecular and cellular biology methods. Among other results, altered expression levels of multiple inflammation and cell proliferation/death balance markers were found and macrophage activation was observed. Overall, the results presented here will be of interest across a variety of biomedical disciplines, including nutrition, orphan diseases, immunology and oncology.

Exploring polyamine regulation by nascent histamine in a human-transfected cell model.

There are multiple lines of evidence suggesting interplay between histamine and polyamines in several mammalian cell types. However, the complex metabolic context makes it difficult to elucidate the mechanisms involved. Histamine's effects can be elicited after its binding to any of the four subtypes of G-protein coupled histamine membrane receptors. In addition, intracellular histamine can also interfere with polyamine metabolism, since there are several metabolic connections between the synthesis and degradation pathways of both types of amines. In order to dissect the metabolic effects of intracellular histamine on polyamine metabolism, we chose a well-known cell culture line, i.e., the human embryonic kidney 293 cells (HEK-293 cells). Initially, we show that HEK-293 cells lack a polyamine metabolic response to extracellular histamine, even over a wide range of histamine concentrations. HEK-293 cells were transfected with active and inactive versions of human histidine decarboxylase, and changes in many of the overlapping metabolic factors and limiting steps were tested. Overall, the results indicate a regulatory effect of histamine on the post-transcriptional expression of ornithine decarboxylase and suggest that this effect is primarily responsible for the decrease in polyamine synthesis and partial blockade of cell-cycle progression, which should affect cell proliferation rate.

Effects of phorbol ester and dexamethasone treatment on histidine decarboxylase and ornithine decarboxylase in basophilic cells.

Both histamine and polyamines are important for maintaining basophilic cell function and viability. The synthesis of these biogenic amines is regulated by histidine decarboxylase and ornithine decarboxylase, respectively. In other mammalian tissues, an interplay between histamine and polyamine metabolisms has been suspected. In this report, the interplay between histamine and ornithine-derived polyamines was studied in a non-transformed mouse mast cell line (C57.1) treated with phorbol ester and dexamethasone, a treatment previously used to increase histidine decarboxylase expression in mastocytoma and basophilic leukemia. Treatment with phorbol ester and dexamethasone increased histidine decarboxylase expression and intracellular histamine levels in C57.1 mast cells to a greater extent than those found for other transformed basophilic models. The treatment also induced a reduction in ornithine decarboxylase expression, intracellular polyamine contents, and cell proliferation. These results indicate that the treatment induces a co-ordinate response of polyamine metabolism and proliferation in mast cells and other immune-related cells. The decrease in the proliferative capacity of mast cells caused by phorbol ester and dexamethasone was simultaneous to an increase in histamine production. Our results, together with those reported by other groups working with polyamine-treated mast cells, indicate an antagonism between histamine and polyamines in basophilic cells.

Histamine prevents polyamine accumulation in mouse C57.1 mast cell cultures.

The effects of histamine on polyamine uptake and metabolism was studied in a mouse mast cell line (C57.1), as a cell model in which both biogenic amines are important for maintaining cell function and viability. Results obtained after incubations with exogenous histamine indicated that histamine prevents polyamine accumulation by affecting polyamine uptake. A plasma membrane transport system for polyamines has been also studied in mast cells. It seems to be a Na(+)-dependent uptake with high affinity for both spermine and spermidine and lower affinity for putrescine and agmatine. Polyamine uptake was reduced in both cells treated with exogenous histamine and histamine-preloaded cells. However, ornithine decarboxylase activity and cell proliferation were not affected by histamine. Incubation with histamine enhanced the spermidine/spermine acetyl transferase induction caused by N(1)-ethyl-N(11)-[(cyclopropyl)methyl]-4,8-diazaundecane, suggesting that polyamine acetylation could be another mechanism by which histamine prevents polyamine accumulation in C57.1 mast cells.

Effects of genistein and 2-methoxyestradiol on matrix metalloproteinases and their inhibitors secreted by Ehrlich ascites tumor cells.

BACKGROUND: Ehrlich ascites tumor is an experimental tumor model very suitable for performing comparative studies relating its growth in vitro and in vivo. We used this tumor model to study the potential modulatory effects of genistein and 2-methoxyestradiol, two anti-angiogenic compounds, on the proteolytic balance MMP/TIMP. Ehrlich cells grown in vitro secreted MMP-9, MMP-2 and two TIMPs; the treatment with either of the anti-angiogenic compounds here tested stimulated all these activities, but the increase in TIMPs activities of genistein-treated cells were higher than those of MMPs, thus inducing a decrease in the proteolytic balance. On the other hand, Ehrlich cells growing in vivo did not produce any detectable TIMP activity, but accumulated MMP-9 and MMP-2 during tumor growth. Both compounds induced significant decrease of MMPs activity when tumor cells were actively proliferating. It was concluded that both genistein and 2-methoxyestradiol could shift the proteolytic balance MMP/TIMP towards antiproteolysis in media or ascitic fluid conditioned by actively growing Ehrlich cells.

An experiment on apoptosis induced by polyamine adducts produced in the presence of serum amine oxidase.

A two-session experiment is proposed to train students with an easy, economic and educative procedure to detect the typical DNA ladder produced in many apoptotic events. The procedure is accurate enough to provide an easy way to compare degrees of damage in DNA caused by different treatments.

A comparative study of the effects of genistein and 2-methoxyestradiol on the proteolytic balance and tumour cell proliferation.

The cytotoxicity of two compounds described as anti-angiogenic, the isoflavone genistein and the oestrogen metabolite 2-methoxyestradiol, has been studied in different human tumour cell lines. Since the degradation of the extracellular matrix is one of the essential steps in angiogenesis, the potential modulatory effects of both compounds on the proteolytic balance in media conditioned by different human tumour cells have been also investigated. The IC50 values for 2-methoxyestradiol were lower than those for genistein on all the cell lines tested. In all the cell lines expressing measurable amounts of active enzymes, genistein induced a shift towards antiproteolysis in both matrix metalloproteinase/tissue inhibitor of metalloproteinase and urokinase/plasminogen activator inhibitor proteolytic balances. On the other hand, 2-methoxyestradiol did not produce any clear net shift of the proteolytic balance, with the significant exception of the matrix metalloproteinase/tissue inhibitor of metalloproteinase balance in WAC-2 cells, a neuroblastoma cell line with enhanced expression of the N-myc oncogene.

[Asthma and pregnancy: some immunologic aspects]. / Asma y embarazo: algunos aspectos inmunológicos.

We studied two groups of pregnant women: 30 asthmatic and 20 non- asthmatic ones (as control), within a eleven-month period. We filled clinical data with inclusion and exclusion criteria for our investigation. We performed tests for determination of E, G, A and M immunoglobulins; and spontaneous rosettes tests and lymphocytic CD4+ and CD8+ subpopulations, as well. We found high IgE levels in the asthmatic pregnant women, in each pregnancy quarter. In relation to IgG and IgA we found a diminishing tendency from the beginning to the end of pregnancy, with statistical meaning, in beth groups of women. We didn't get significant variations for IgM, spontaneous rosettes and lymphocytic CD4+ and CD8+ subpopulations levels, in any of the two pregnant groups, in any of three pregnancy quarters, in our investigation.

A case-control study of BCG and childhood tuberculosis in Cali, Colombia.

We conducted a case-control study to evaluate the effectiveness of BCG vaccination in preventing childhood tuberculosis (TB) in Cali, Colombia. We ascertained 178 cases aged 0 to 14 years from the respiratory clinics with cough or fever for at least three weeks and a positive chest X-ray for TB, as well as 320 controls who were from the same households but had no symptoms and negative X-rays. Using matched set multiple logistic regression analysis, we found the age- and sex-adjusted relative risk (RR) of TB among vaccinees compared with non-vaccinees to be 0.84 with 95% confidence limits (CL) from 0.43 to 1.62. There was, however, a significantly lowered relative risk of TB with increasing time since vaccination (RR = 0.83 per year since time of vaccination with 95% CL from 0.74 to 0.94.)

[Central serous choroiditis. Possible allergic etiopathogenesis] Preliminary report]. / Coroiditis central serosa. Posible etiopatogenia alérgica. Comunicación preliminar.

We performed a study of all patients with Central Serous Choroiditis that were attended in Ophthalmology consultation, both on ambulatory and emergency services, as well as in Allergy-Ophthalmology inter-consultations at the Provincial Educational Hospital "Saturnino Lora" in Santiago de Cuba, from January 1982 until July 1984. These patients were divided in two groups: A and B; the former was treated with suppression and challenge diets, and with antihistaminic drugs: the latter with conventional therapeutic agents. We established several criteria for the evaluation of results as: Good, Fair and Bad. We followed a similar procedure in evaluating the inflammatory state of the eye fundus as Discreet, Moderate and Severe. With the first evaluation of treatment at 15 days, we observed greater improvement in patients from group A than with patients from group B.

Two stages in lymphocyte mediator production by differential susceptibility to blockade using niridazole.

Sera from guinea pigs given niridazole, an anti-schistosomal compound, have been shown to reversibly block the production of antigen-induced migration inhibitory factor by sensitized guinea pig lymph node cells. Since niridazole itself has no effect in vitro, the blockade of production of migration inhibitory factor is probably due to drug metabolites in the serum. We report here further studies on the mechanism of this drug-induced suppression of cellular hypersensitivity; the data show that niridazole active serum does not block the production of migration inhibitory factor once it has been initiated. Indeed, if niridazole active serum is added a little as 60 sec after the addition of antigen, the lymphocytes will produce migration inhibitory factor. These results suggest the presence of at least two stages in production of migration inhibitory factor after the addition of antigen to lymphocytes. The first, lasting less than 60 sec, is susceptible to blockade by niridazole active serum; the second is not. The elucidation of the mechanism of this blockade should lead to further understanding of the early events after antigen triggering of sensitized lymphocytes.

The enhancement of macrophage bacteriostasis by products of activated lymphocytes.

It was reported previously that the incubation of normal guinea pig macrophages with partially purified products of activated lymphocytes resulted in altered macrophage function including increased cell adherence to culture vessels, spreading, phagocytosis, and glucose carbon-1 oxidation. Studies reported here demonstrate that such macrophages also exhibit enhanced bacteriostasis. Lymphocytes were stimulated with concanavalin A, the culture supernatant was chromatographed over Sephadex G-100 and the fraction of mol wt 25,000-55,000, rich in lymphocyte mediators, was cultured with normal guinea pig macrophages for 1-3 days. Macrophages incubated with fractions from unstimulated lymphocyte cultures served as controls. The resulting macrophage monolayers were infected with Listeria monocytogenes. Macrophages incubated with mediator-rich fractions exhibited 2- to 10-fold enhanced bacteriostasis compared to controls. Further studies indicate that this enhancement was attributable to intrinsic changes in the macrophages and not simply a consequence of the number of macrophages on the monolayers. The studies support the concept that macrophage bacteriostasis can be enhanced by lymphocyte mediators. However, macrophages, which have been preincubated directly with sensitive lymphocytes and antigen exhibit even greater bacteriostasis and sometimes bactericidal capacity, suggesting that either a labile lymphocyte factor or direct lymphocyte macrophage interaction may also be involved in bactericidal activity.