8-hydroxy-2'-deoxyguanosine, a major mutagenic oxidative DNA lesion, and DNA strand breaks in nasal respiratory epithelium of children exposed to urban pollution.

Southwest metropolitan Mexico City children are repeatedly exposed to high levels of a complex mixture of air pollutants, including ozone, particulate matter, aldehydes, metals, and nitrogen oxides. We explored nasal cell 8-hydroxy-2'-deoxyguanosine (8-OHdG), a major mutagenic lesion producing G-->T transversion mutations, using an immunohistochemical method, and DNA single strand breaks (ssb) using the single cell gel electrophoresis assay as biomarkers of oxidant exposure. Nasal biopsies from the posterior inferior turbinate were examined in children in grades one through five, including 12 controls from a low-polluted coastal town and 87 Mexico City children. Each biopsy was divided for the 8-OHdG and DNA ssb assays. There was an age-dependent increase in the percentage of nasal cells with DNA tails > 10 microm in Mexico City children: 19 +/- 9% for control cells, and 43 +/- 4, 50 +/- 16, 56 +/- 17, 60 +/- 17 and 73 +/- 14%, respectively, for first through fifth graders (p < 0.05). Nasal ssb were significantly higher in fifth graders than in first graders (p < 0.05). Higher levels (2.3- to 3-fold) of specific nuclear staining for 8-OHdG were observed in exposed children as compared to controls (p < 0.05). These results suggest that DNA damage is present in nasal epithelial cells in Mexico City children. Persistent oxidative DNA damage may ultimately result in a selective growth of pr eneoplastic nasal initiated cells in this population and the potential for nasal neoplasms may increase with age. The combination of 8-OHdG and DNA ssb should be useful for monitoring oxidative damage in people exposed to polluted atmospheres

Observation of gravitational waves from the coalescence of a 2.5–4.5 M ⊙ compact object and a neutron star

We report the observation of a coalescing compact binary with component masses 2.5–4.5 M ⊙ and 1.2–2.0 M ⊙ (all measurements quoted at the 90% credible level). The gravitational-wave signal GW230529_181500 was observed during the fourth observing run of the LIGO–Virgo–KAGRA detector network on 2023 May 29 by the LIGO Livingston observatory. The primary component of the source has a mass less than 5 M ⊙ at 99% credibility. We cannot definitively determine from gravitational-wave data alone whether either component of the source is a neutron star or a black hole. However, given existing estimates of the maximum neutron star mass, we find the most probable interpretation of the source to be the coalescence of a neutron star with a black hole that has a mass between the most massive neutron stars and the least massive black holes observed in the Galaxy. We provisionally estimate a merger rate density of 55−47+127Gpc−3yr−1 for compact binary coalescences with properties similar to the source of GW230529_181500; assuming that the source is a neutron star–black hole merger, GW230529_181500-like sources may make up the majority of neutron star–black hole coalescences. The discovery of this system implies an increase in the expected rate of neutron star–black hole mergers with electromagnetic counterparts and provides further evidence for compact objects existing within the purported lower mass gap

Correlation between the scapholunate space and clinical evolution in distal radius fractures

Introduction. Scapholunate instability is the most frequent carpal instability. It covers a wide spectrum of injuries and is usually associated with distal radius fractures. Objective. The aim of the study was to correlate the clinical evolution in patients with distal radius fractures with and without the opening of the scapholunate space. Methods. An observational, prospective, and comparative study was carried out at our institution. We included patients over 18 years of age with a diagnosis of distal radius fracture. The scapholunate space was measured, and pain and wrist functionality were evaluated after removing the cast and nails using the DASH and PRWE scales. Results. A total of 90 patients were included in the study. The mean age of the patients was 52.7 ± 16.8 years. About 56.7% were women, and 43.3% were men. A space < 2.5 mm was found in 34 (37.8%) and < 2 mm in 51 (56.7%). We found a decrease in scores over 8 weeks that was less than the baseline scores in patient groups with both an open and closed scapholunate space, indicating a better clinical outcome. We found a similar clinical course at 8 weeks in both groups. Conclusions. Patients with distal radius fractures present a favorable clinical evolution over the course of 8 weeks after the removal of the nails and plaster used to immobilize the fracture. The opening of the scapholunate space does not interfere with the prognosis of the patients

Síndrome de Aicardi: Presentación de un caso clínico y revisión de la literatura.

El síndrome de Aicardi (SA), es una rara enfermedad neurogenética, diagnosticada clínicamente por la triada clásica de agenesia del cuerpo calloso, espasmos infantiles y lagunas corioretinales.El objetivo de nuestro trabajo fue presentar el espectro clínico y la evolución de este trastorno en un caso. Reportamos una lactante de dos meses, de malformaciones cerebrales múltiples, que ingresa a emergencia por presentar crisis convulsivas. Durante la hospitalización, los hallazgos clínicos – electroencefalográficos, neuroimágenes y evaluación oftalmológica confirman el diagnóstico de SA. Se resalta la importancia de conocer las manifestaciones clínicas del síndrome, para tenerlo en cuenta como diagnóstico diferencial, sobre todo en aquellos casos que presenten espasmos infantiles asociados a agenesia del cuerpo calloso

An Ethnographic Assessment of COVID-19‒Related Changes to the Risk Environment for People Who Use Drugs in Tijuana, Mexico

Objectives. To characterize the effects of the onset of the COVID-19 pandemic on the risk environment of people who use drugs (PWUD) in Tijuana, Mexico. Methods. We used intensive participant-observation ethnography among street-based PWUD and key informants, such as frontline physicians and harm reductionists. Results. PWUD described an unprecedented cessation of police violence and extortion during the initial pandemic-related lockdown, though this quickly reversed and police violence worsened. Government-provided housing and medical treatment with methadone were temporarily provided to PWUD in a dedicated clinic, yet only for PWUD with COVID-19 symptoms. Concurrently, non‒COVID-19‒related hospital care became virtually inaccessible, and many PWUD died of untreated, chronic illnesses, such as hepatitis C, and soft-tissue infections. Border closures, decreases in social interaction, and reduced drug and sex tourism resulted in worsening food, income, and housing insecurity for many PWUD. By contrast, potent illicit drugs remained easily accessible in open-air drug markets. Conclusions. The pandemic exacerbated health risks for PWUD but also offered profound glimpses of beneficial structural changes. Efforts are needed in Tijuana and elsewhere to institutionalize positive pandemic-related shifts and ameliorate novel harms for PWUD. (Am J Public Health. 2022;112(S2):S199-S202. https://doi.org/10.2105/AJPH.2022.306796)

Risk factors of breast cancer in Mexican women Factores de riesco de cáncer de mama en mujeres mexicanas

OBJECTIVE: To investigate the association between family history (FH) of neoplasia, gyneco-obstetric factors and breast cancer (BC) in a case--control study. In cases, to analyze those variables in relation with early onset of BC, the manner of detection (self-examination, prompted by pain, or casual), the size of tumor, and the elapsed time to seek medical attention. MATERIAL AND METHODS: Data from 151 prevalent BC cases and 235 age-matched controls were analyzed by multiple logistic regression, to assess the influence of BC risk factors. RESULTS: Ten per cent of patients and 1% of controls had first-degree relatives (FDR) with BC. Family history of FDR with BC (OR, 11.2; 95% CI 2.42-51.92) or with gastric or pancreatic cancer (OR, 17.7; 95% CI 2.2-142.6) was associated with BC risk. Breastfeeding at or under 25 years of age was protective against BC (OR, 0.40; 95% CI 0.24-0.66). The manner of tumor detection did not influence its size at the time of diagnosis. CONCLUSIONS: Our study confirms that FH of BC and/or of gastric or pancreatic carcinoma are risk factors for BC, while lactation at 25 years of age or earlier is protective.<br>OBJETIVO: Investigar la asociación entre la historia familiar de neoplasias, factores ginecobstétricos y cáncer mamario (CM) en un estudio de casos y controles. Además, en los casos, estudiar estas variables en relación con inicio temprano del cáncer, forma de detección (autoexamen, exploración individual por dolor o casual), tamaño del tumor. MATERIAL E MÉTODOS: Entre enero y marzo de 1997 se estudiaron 151 casos prevalentes de CM y 235 controles pareados por edad provenientes del Hospital de Especialidades del Centro Médico del Noreste, Instituto Mexicano del Seguro Social, o del Hospital Universitario de la Universidad Autónoma de Nuevo León, ambos localizados en Monterrey, México. Los factores de riesgo se analizaron con regresión logística múltiple. RESULTADOS: Diez por ciento de casos y 1% de controles tuvieron historia familiar de primer grado para CM; este antecedente (razón de momios --RM, 11.2; IC 95%; 2.42-51.92) y el de carcinoma gástrico o pancreático (RM, 17.7; IC 95%; 2.2-142.6) se asociaron con riesgo de CM. El amamantar a los 25 años o menos fue factor protector (RM, 0.40; IC 95%; 0.24-0.66). La forma de detección del tumor no influyó en el tamaño del tumor al momento del diagnóstico. CONCLUSIONES: Se mostró que la historia familiar de CM y de carcinoma gástrico o pancreático son factores de riesgo para CM, mientras que la lactancia a los 25 años o antes, es protectora