Disruptive Model That Explains for the Long-Lived Triplet States Observed for 2-Thiocytosine upon UVA Radiation.

The possible role of radical species in the formation of the long-lived triplet states observed for 2-thiocytosine upon UV irradiation was theoretically investigated. It is predicted that the radical fragments arising from the homolytic rupture of the NH group of the thiobase can be yielded upon ultraviolet-A radiation. Recombination of the radicals through the most favorable singlet channel yields the lowest-lying tautomer of the 2-thiocytosine (the amino-thiol form) through a barrierless pathway. The rebounding of the radical fragments along the triplet channels that emerge from the attack of the hydrogen to the nitrogen atoms next to the C-S bond leads to stable structures for the amino-thion-N1H and amino-thion-N3H tautomers. These results allow for the rationalization of the near-unity triplet yields observed when this pure light-atom organic molecule is exposed to UV irradiation, without invoking intersystem crossings between the electronic states of different spin-multiplicities. A similar study for cytosine showed that the energy required to induce the homolytic breaking of the N-H bond of the nucleobase is not attainable under UVA radiation. This result is consistent with the experimental fact that no triplet states are observed when this molecule is exposed to that light.

Sociodemographic, clinical and laboratory characteristics and risk factors for mortality of hospitalized COVID-19 patients at alternate care site: a Latin American experience.

BACKGROUND: The establishment of Alternate Care Sites (ACS) helped the most severely impacted countries expand their response capability. The aim of this study was to evaluate the clinical characteristics and risk factors associated with the mortality of hospitalized COVID-19 patients at Alternate Care Site in Mexico City. PATIENTS AND METHODS: A monocentric cohort study was conducted at Mexico City's Temporary Unit COVID-19 (UTC-19). Sociodemographic, clinical, laboratory and treatment variables were included in the analysis. RESULTS: A total of 4865 patients were included, with a mean age of 49.33 years ± SD 15.28 years (IQR 38 to 60 years); 50.53% were women. 63.53% of the patients presented at least one comorbidity, the most frequent being: obesity (39.94%), systemic arterial hypertension (25.14%), and diabetes mellitus (21.52%). A total of 4549 patients (93.50%) were discharged due to improvement, 64 patients (1.31%) requested voluntary discharge, 39 patients (0.80%) were referred to another unit, and 213 patients (4.37%) died. Factors that were independently and significantly associated with death included male gender (odds ratio [OR], 1.60), age ≥ 50 years (OR 14.75), null or low schooling (OR 3.47), have at least one comorbidity (OR 3.26), atrial fibrillation (OR 22.14). In the multivariate analysis, the lymphopenia ≤ 1 × 103/µL (OR 1.91), and having required steroid treatment (OR 2.85), supplemental oxygen with high-flow nasal cannula (OR 3.12) or invasive mechanical ventilation (OR 42.52), was significantly associated with an increased risk of death. CONCLUSIONS: This study identified the clinical characteristics and risk factors for mortality of hospitalized COVID-19 patients at ACS in Mexico City.KEY MESSAGESAn Alternate Care Site (ACS) is any building or structure that is temporarily converted or constructed for healthcare use during a public health emergency.Factors associated with death included male gender, age over 50 years, and lower educational attainment (elementary school or less).The findings corroborate the utility of the CALL score as a predictor of mortality; lymphopenia ≤1 × 103/µL was the most relevant biomarker.

Medical Household Waste as a Potential Environmental Hazard: An Ecological and Epidemiological Approach.

Nowadays, the contamination caused by emerging pollutants is a global concern due to the lack of scientific evidence to demonstrate the risk or toxicity to humans due to the presence of pharmaceutical residues in the environment. This study aimed to identify and describe the disposal practices of unused and unwanted medications, as well as to analyze and identify the most frequent drugs determined on water bodies adjacent to the biggest urban population in Mexico. A two-phase study with an epidemiological and an ecological assessment was performed. The epidemiological phase was carried out with a descriptive cross-sectional study among citizens from Mexico City and the metropolitan area using an electronic survey applied to 719 subjects aimed to assess practices in which pharmaceutical products are disposed. The ecological phase included a review of scientific reports. The results show that nearly 83.5% of those surveyed use inappropriate practices for disposal medicines, the main ones are through the municipal dump or directly in the drain. The ecological approach was carried out by a systematic literature review of original reports published between 2013 to 2023; information about the class of drugs, active substance, environmental compartments, location, and concentration was extracted and presented. Fifty-one different types of pharmaceutical residues were detected in wastewater in Mexico City in the last decade. The results of this study can contribute to the application of public policies for waste management authorities to mitigate the socio-environmental risks due to the inappropriate disposal of medicines.

Prognostic factors in cancer patients infected with SARS-CoV-2: a Latin American country results.

PURPOSE: The aim of this study was to evaluate the demographic characteristics, clinical and pathological factors, and the outcome of cancer and COVID-19 patients in Mexico. PATIENTS AND METHODS: A prospective, multicentric study was performed through a digital platform to have a national registry of patients with cancer and positive SARS-CoV-2 test results through reverse transcription quantitative polymerase chain reaction (RT-qPCR). We performed the analysis through a multivariate logistic regression model and Cox proportional hazard model. RESULTS: From May to December 2020, 599 patients were registered with an average age of 56 years with 59.3% female; 27.2% had hypertension. The most frequent diagnoses were breast cancer (30.4%), lymphoma (14.7%), and colorectal cancer (14.0%); 72.1% of patients had active cancer and 23.5% of patients (141/599) were deceased, the majority of which were men (51.7%). This study found that the prognostic factors that reduced the odds of death were gender (OR = 0.42, p = 0.031) and oxygen saturation (OR = 0.90, p = 0.0001); meanwhile, poor ECOG (OR = 5.4, p = 0.0001), active disease (OR = 3.9, p = 0.041), dyspnea (OR = 2.5, p = 0.027), and nausea (OR = 4.0, p = 0.028) increased the odds of death. In the meantime, the factors that reduce survival time were age (HR = 1.36, p = 0.035), COPD (HR = 8.30, p = 0.004), having palliative treatment (HR = 10.70, p = 0.002), and active cancer without treatment (HR = 8.68, p = 0.008). CONCLUSION: Mortality in cancer patients with COVID-19 is determined by prognostic factors whose identification is necessary. In our cancer population, we have observed that being female, younger, non-COPD, with non-active cancer, good performance status, and high oxygen levels reduce the probability of death.

Kinetics of HE4 and CA125 as prognosis biomarkers during neoadjuvant chemotherapy in advanced epithelial ovarian cancer.

BACKGROUND: Ovarian cancer (OC) is considered the most lethal gynecological cancer, of which more than 65% cases are diagnosed in advanced stages, requiring platinum-based neoadjuvant chemotherapy (NACT). METHODS: A prospective-longitudinal study was conducted among women with advanced epithelial ovarian cancer (AEOC), III and IV stages, and treated with NACT, at the National Cancer Institute - Mexico, from July 2017 to July 2018. Serum samples were obtained for quantification of CA125 and HE4 using ELISA at the first and in each of the three NACT cycles. The therapeutic response was evaluated through standard tomography. We determined whether CA125 and HE4, alone or in combination, were associated with TR to NACT during follow up. RESULTS: 53 patients aged 38 to 79 years were included, 92.4% presented papillary serous subtype OC. Higher serum HE4 levels were observed in patients with non-tomographic response (6.89 vs 5.19 pmol/mL; p = 0.031), specially during the second (p = 0.039) and third cycle of NACT (p = 0.031). Multivariate-adjusted models showed an association between HE4 levels and TR, from the second treatment cycle (p = 0.042) to the third cycle (p = 0.033). Changes from baseline HE4 levels during the first cycle was negative associated with TR. No associations were found between CA125 and TR. CONCLUSIONS: Serum HE4 levels were independently associated with TR among patients with AOEC treated with NACT, also a reduction between baseline HE4 and first chemotherapy levels was also independently associated with the TR. These findings might be relevant for predicting a lack of response to treatment.

Desmoid-Type Fibromatosis.

Desmoid tumors represent a rare entity of monoclonal origin characterized by locally aggressive behavior and inability to metastasize. Most cases present in a sporadic pattern and are characterized by a mutation in the CTNNB1 gene; while 5-15% show a hereditary pattern associated with APC gene mutation, both resulting in abnormal ß-catenin accumulation within the cell. The most common sites of presentation are the extremities and the thoracic wall, whereas FAP associated cases present intra-abdominally or in the abdominal wall. Histopathological diagnosis is mandatory, and evaluation is guided with imaging studies ranging from ultrasound, computed tomography or magnetic resonance. Current approaches advocate for an initial active surveillance period due to the stabilization and even regression capacity of desmoid tumors. For progressive, symptomatic, or disabling cases, systemic treatment, radiotherapy or surgery may be used. This is a narrative review of this uncommon disease; we present current knowledge about molecular pathogenesis, diagnosis and treatment.

Regulation of ovule initiation by gibberellins and brassinosteroids in tomato and Arabidopsis: two plant species, two molecular mechanisms.

Ovule primordia formation is a complex developmental process with a strong impact on the production of seeds. In Arabidopsis this process is controlled by a gene network, including components of the signalling pathways of auxin, brassinosteroids (BRs) and cytokinins. Recently, we have shown that gibberellins (GAs) also play an important role in ovule primordia initiation, inhibiting ovule formation in both Arabidopsis and tomato. Here we reveal that BRs also participate in the control of ovule initiation in tomato, by promoting an increase on ovule primordia formation. Moreover, molecular and genetic analyses of the co-regulation by GAs and BRs of the control of ovule initiation indicate that two different mechanisms occur in tomato and Arabidopsis. In tomato, GAs act downstream of BRs. BRs regulate ovule number through the downregulation of GA biosynthesis, which provokes stabilization of DELLA proteins that will finally promote ovule primordia initiation. In contrast, in Arabidopsis both GAs and BRs regulate ovule number independently of the activity levels of the other hormone. Taken together, our data strongly suggest that different molecular mechanisms could operate in different plant species to regulate identical developmental processes even, as for ovule primordia initiation, if the same set of hormones trigger similar responses, adding a new level of complexity.

Perinatal administration of bisphenol A alters the expression of tight junction proteins in the uterus and reduces the implantation rate.

We studied the effect of bisphenol-A (BPA) administration to rats, during the perinatal period, on the fertility of F1 generation and on the expression of tight junction (TJ) proteins in the uterus during early pregnancy. Pregnant Wistar dams (F0) received: BPA-L (0.05mg/kg/day), BPA-H (20mg/kg/day) or vehicle, from gestational day (GD) 6 to lactation day 21. F1 female pups were mated at 3 months of age and sacrificed at GD 1, 3, 6, and 7. Serum hormonal levels, ovulation rate, number of implantation sites and expression of TJ proteins in the uterus of F1 females were evaluated. BPA treatment induced no change in ovulation rate, but induced alterations in progesterone (P4) and estradiol (E2) serum levels, and in implantation rate. With regards to TJ proteins, BPA-H increased claudin-1 during all GDs; eliminated the peaks of claudins -3 and -4 at GD 3 and 6, respectively; and decreased claudin-7 at GD 6, ZO-1 from GD 1-6, and claudin-3 at GD 7 in stromal cells. BPA-L instead, eliminated claudin-3 peak at GD 3, increased claudin-4 and decreased claudin-7 from GD 1-6, decreased claudin-1 at GD 3 and 7 and claudin-4 at GD 7 in stromal cells. BPA-L also decreased ZO-1 at GDs 1 and 3 and increased ZO-1 at GD 6. Thus, BPA treatment during perinatal period perturbed, when the animals reached adulthood and became pregnant, the particular expression of TJ proteins in the uterine epithelium and reduced in consequence the number of implantation sites.

[Active management of the premature membrane rupture in pregnancies of 34 to 37 weeks]. / Manejo activo de la rotura prematura de membranas en embarazos de 34 a 37 semanas.

BACKGROUND: Premature rupture of membranes is considered an obstetrical emergency since it has been associated with an increment of sepsis and maternal-fetal morbidity. For this reason, controversy exists among conservative and active management for the obstetrical resolution. OBJECTIVE: To determine if active management of premature rupture of membranes in pregnancy of 34 to 37 weeks diminishes the cesarean section incidence and the maternal-fetal morbidity. PATIENTS AND METHODS: Two groups of patients with pregnancy of 34 to 37 weeks and premature rupture of membranes were compared. Group I with active management was integrated by 42 cases that initiated inductoconduction at their admission to the hospital, and in group II, with 26 cases on the conservative management, medication was used to induce fetal pulmonary maturity and spontaneous delivery was expected. Descriptive statistics was carried out by means of the statistical package SPSS-10. RESULTS: The mean age of the patients was 27.2 +/- 5.8 years. Pregnancy resolution within the first 12 hours was 23.8% in group I and 11.5% in group II. Cesarean section in group I was made in 28.5% of the cases and in group II in 65.3% of them (p < 0.05). The most common indication for cesarean section in group I was stationary labor (16.5%) and in group II unfavorable cervical conditions (26.9%). Maternal and newborn hospital stay was greater in group II (p < 0.01). The most frequent maternal complication in both groups was decidual infection, with 4.7 and 15.3%, respectively. General maternal and neonatal morbidity was greater in group II. CONCLUSIONS: Conservative management of premature rupture of membranes, when pregnancy is equal or greater than 34 weeks, does not offer fetal benefits, increases the incidence of cesarean sections, the hospital stay and the cost of the medical attention.