Cutaneous Horn Presentation in Porokeratotic Eccrine Ostial and Dermal Duct Nevus. A Brief Review and Case Report.

ABSTRACT: Porokeratotic eccrine ostial and dermal duct nevus is a rare adnexal hamartoma characterized by the presence of a cornoid lamella exclusively overlying eccrine acrosyringia. Different clinical presentations have been reported in the literature. Here, we report a case of a 6-year-old girl diagnosed with porokeratotic eccrine ostial and dermal duct nevus confirmed by histopathologic study. Atypical lesions are described as whitish, warty-looking neoformations located in the anterolateral region of the right hip (cutaneous horn).

Plasma Catalysis for Hydrogen Production: A Bright Future for Decarbonization.

Thermal approaches have played a dominant role in driving chemical reactions within the chemicals and fuels industries, benefiting from ongoing enhancements in efficiency via heat integration, catalyst development, and process intensification. Nevertheless, these traditional thermal approaches remain heavily reliant on fossil fuels, and there exists an urgent demand for the implementation of renewable energy technologies to synthesize fuels, commodity chemicals, and specialty chemicals. Nonthermal plasmas have gained considerable attention in recent years as a promising solution, and the prospects of combining plasmas with suitable catalysts have become even more appealing. Moreover, the evolution of nonthermal plasma catalysis approaches for the generation of clean hydrogen could be transformative in reducing greenhouse gas emissions. This comprehensive review highlights the influential contributions in plasma catalysis for hydrogen production, discusses recent advancements, and provides future prospects for researchers aiming to advance the production of clean hydrogen.

Contributions of Laurent Princeteau to Trigeminal Neuralgia and Middle Fossa Anatomy: More than a Mere Tubercle.

The contributions of Laurent Princeteau (1858-1932) to anatomy and to the establishment of neurosurgery have largely gone unrecognized, perhaps because he was educated and practiced in a French city other than Paris at a time when Paris was one of the chief centers of medicine in Europe. After completing a thesis describing an iliac artery anomaly and obtaining the distinguished agrégé teaching degree, Princeteau began his surgical career at the University of Bordeaux. Within 10 years, he became chef de clinique and one of the busiest surgeons in Saint-André Hospital, as well as head of the anatomy institute and professor of anatomy at the dental school. In 1891, he achieved the rank of surgeon. In the field of general anatomy, he was recognized for novel cadaveric preparations and vascular perfusion techniques. In the neurosciences, he made important contributions to the anatomy of the trigeminal nerve and trigeminal neuralgia. In 1898, Princeteau supervised a thesis that addressed contemporary surgical approaches to the trigeminal complex. In the course of this effort, he identified a bony prominence near the petrous apex (the retrogasserian tubercle) that helped to locate the gasserian ganglion. The surgical significance of the retrogasserian tubercle was quickly acknowledged in the European neurosurgical community and was noted in French textbooks of anatomy. Thierry de Martel, a founding member of the French neurosurgical School, named the tubercle after Princeteau. To the rest of the world, however, it remained almost unknown.

A randomized intraindividual comparative study evaluating the effects of two ultrasound-assisted liposuction devices on the abdomen.

BACKGROUND: Ultrasound-assisted liposuction (UAL) has become popular because of its favorable outcomes in fat emulsification, blood loss reduction, and skin tightening. This study aimed to compare the effects of two UAL devices on the abdomen by assessing postsurgery skin biomechanical properties. METHODS: This single-blind, prospective study (2020-2022) involved 13 liposuction procedures performed on patients without chronic diseases. Each patient's abdomen was divided vertically from the xiphoid to the perineum. Vibration amplification of sound energy at resonance (VASER)-assisted liposuction (Solta Medical, Inc., Hayward, CA) was performed on one half, while the other half underwent liposuction with high-frequency ultrasound energy (HEUS)-assisted technology. Skin biomechanical measurements, including distensibility, net elasticity, biological elasticity, hydration, erythema, melanin, and skin firmness, were taken at 12 and 24 months postsurgery, focusing on the anterior abdomen, 8 cm to the right and left of the umbilicus. RESULTS: Analysis of the above skin biomechanical measurements revealed no significant differences between the HEUS and VASER devices, except for skin firmness, which showed a notable increase following HEUS surgery. Patient-perceived clinical differences were assessed via nonvalidated questionnaires, revealing no distinctions between devices. CONCLUSION: Biomechanical skin results post-UAL surgery with these devices on the abdomen were not significantly different, although HEUS revealed increased skin firmness. This suggests that HEUS-assisted technology, akin to other devices, is a viable option for UAL procedures.

Buccal Fat Pad Herniation, Repositioning Versus Excision: A New Algorithm of Treatment.

Background: Traumatic herniation of the buccal fat pad can be treated with repositioning or excision. This report describes a case of a child with traumatic herniation of the buccal fat pad treated with excision. A comprehensive review of the literature was performed with the objective of establishing treatment criteria for the decision-making involved in choosing between repositioning versus excision. Methods: A systematic review of the literature was performed through searches of PubMed, Ovid, Elsevier, Cochrane, ResearchGate and Google Scholar for reports published from 1968 through May 2021. The search keywords used were traumatic herniation of the buccal fat pad, buccal fat pad herniation, traumatic pseudolipoma, and traumatic lipoma. We included only those studies that included patients with intraoral buccal fat pad herniation. Results: We found and included 39 articles (44 patients). Time since trauma, size of the fat pad herniated, and presence of necrosis were the most important characteristics considered for treatment decision; on the basis of these factors, we created a treatment algorithm. We present a case report of a 2-year-old boy diagnosed with traumatic herniation of buccal fat pad and, according to our algorithm, the appropriate treatment was to perform excision. A follow-up examination at 11 months showed no complications. Conclusions: Because traumatic herniation of buccal fat pad is very rare, this algorithm can be an easy and effective tool to guide decision-making when choosing between repositioning versus excision.

Further studies on the potential contribution of acetaldehyde accumulation and oxidative stress in rat mammary tissue in the alcohol drinking promotion of breast cancer.

There is available evidence supporting a positive association between alcohol intake and risk of breast cancer. However, there is limited information regarding possible mechanisms for this effect. Past studies from our laboratory suggest that acetaldehyde accumulation in mammary tissue after alcohol intake may be of particular relevance and that cytosolic and microsomal in situ bioactivation of ethanol to acetaldehyde and free radicals and the resulting stimulation of oxidative stress could be a significant early event related to tumor promotion. In the present studies repetitive alcohol drinking for 28 days was found to produce significant decreases in the mammary tissue content of GSH and alpha tocopherol and in glutathione S-transferase or glutathione reductase activities. In contrast, glutathione peroxidase activity was slightly increased. Malondialdehyde determinations did not show the occurrence of lipid peroxidation while the xylenol orange procedure gave positive results. The mammary microsomal metabolism of ethanol to acetaldehyde was not induced after an acute dose of ethanol or acetone able to induce the activity of its liver counterpart. The cytosolic pathway of alcohol metabolism instead was significantly enhanced by these two treatments. No increased generation of comet images was found either in mammary tissue or in liver under the experimental conditions tested. Results suggest that, while acetaldehyde accumulation in mammary tissue could be a critical event resulting from increasing production of acetaldehyde in situ plus an additional amount of it arriving via blood, other factors such as poor handling of the accumulated acetaldehyde could be also relevant.

Pediatric Oncology Palliative Care Programs in Central America: Pathways to Success.

Palliative care offers children who have life-limiting and life-threatening oncologic illnesses and their families improved quality of life. In some instances, impeccable symptom control can lead to improved survival. Cultural and financial barriers to palliative care in oncology patients occur in all countries, and those located in Central America are no exception. In this article, we summarize how the programs participating in the Asociación de Hemato-Oncólogos Pediatras de Centro America (AHOPCA) have developed dedicated oncology palliative care programs. The experience in Guatemala, El Salvador, Costa Rica, Panama, Dominican Republic and Haiti is detailed, with a focus on history, the barriers that have impeded progress, and achievements. Future directions, which, of course, may be impacted by the COVID-19 pandemic, are described as well.

Effects of Short-Term Random Noise Electrical Stimulation on Dissociated Pyramidal Neurons from the Cerebral Cortex.

Transcranial random noise electrical stimulation (tRNS) of the human brain is a non-invasive technique that can be employed to increase the excitability of the cerebral cortex; however, the physiological mechanisms remain unclear. Here we report for the first time the effects of short-term (250 ms) random noise electrical stimulation (RNS) on in-vitro acutely-isolated brain pyramidal neurons from the somatosensory and auditory cerebral cortex. We analyzed the correlation between the peak amplitude of the Na+ current and its latency for different levels of RNS. We found three groups of neurons. The first group exhibited a positive correlation, the second, a negative correlation, and the third group of neurons did not exhibit correlation. In the first group, both the peak amplitude of a TTX-sensitive Na+ current and its inverse of latency followed similar inverted U-like functions relative to the electrical RNS level. In this group, the RNS levels in which the maximal values of the inverted U-like functions occurred were the same. In the second group, the maximal values of the inverted U-like functions occurred at different levels. In the third group, only the peak amplitude of the Na+ current exhibited a clear inverted U-like function, but the inverse of the latency versus the electrical RNS, did not exhibit a clear inverted U-like function. A Hodgkin-Huxley neuron model reproduces our experimental results and shows that the observed behavior in the Na+ current could be due to the impact of RNS on the kinetics of activation and inactivation of the Na+ channels.

Bovine Lactoferrin and Lactoferrin-Derived Peptides Inhibit the Growth of Vibrio cholerae and Other Vibrio species.

Vibrio is a genus of Gram-negative bacteria, some of which can cause serious infectious diseases. Vibrio infections are associated with the consumption of contaminated food and classified in Vibrio cholera infections and non-cholera Vibrio infections. In the present study, we investigate whether bovine lactoferrin (bLF) and several synthetic peptides corresponding to bLF sequences, are able to inhibit the growth or have bactericidal effect against V. cholerae and other Vibrio species. The antibacterial activity of LF and LF-peptides was assessed by kinetics of growth or determination of colony forming unit in bacteria treated with the peptides and antibiotics. To get insight in the mode of action, the interaction between bLF and bLF-peptides (coupled to FITC) and V. cholera was evaluated. The damage of effector-induced bacterial membrane permeability was measured by inclusion of the fluorescent dye propidium iodide using flow cytometry, whereas the bacterial ultrastructural damage in bacteria treated was observed by transmission electron microscopy. The results showed that bLF and LFchimera inhibited the growth of the V. cholerae strains; LFchimera permeabilized the bacteria which membranes were seriously damaged. Assays with a multidrug-resistant strain of Vibrio species indicated that combination of sub-lethal doses of LFchimera with ampicillin or tetracycline strongly reduced the concentration of the antibiotics to reach 95% growth inhibition. Furthermore, LFchimera were effective to inhibit the V. cholerae counts and damage due to this bacterium in a model mice. These data suggest that LFchimera and bLF are potential candidates to combat the V. cholerae and other multidrug resistant Vibrio species.

Refractive errors among children, adolescents and adults attending eye clinics in Mexico.

AIM: To assess the proportion of refractive errors in the Mexican population that visited primary care optometry clinics in fourteen states of Mexico. METHODS: Refractive data from 676 856 patients aged 6 to 90y were collected from optometry clinics in fourteen states of Mexico between 2014 and 2015. The refractive errors were classified by the spherical equivalent (SE), as follows: sphere+½ cylinder. Myopia (SE>-0.50 D), hyperopia (SE>+0.50 D), emmetropia (-0.50≤SE≤+0.50), and astigmatism alone (cylinder≥-0.25 D). A negative cylinder was selected as a notation. RESULTS: The proportion (95% confidence interval) among all of the subjects was hyperopia 21.0% (20.9-21.0), emmetropia 40.7% (40.5-40.8), myopia 24.8% (24.7-24.9) and astigmatism alone 13.5% (13.4-13.5). Myopia was the most common refractive error and frequency seemed to increase among the young population (10 to 29 years old), however, hyperopia increased among the aging population (40 to 79 years old), and astigmatism alone showed a decreasing trend with age (6 to 90y; from 19.7% to 10.8%). There was a relationship between age and all refractive errors (approximately 60%, aged 50 and older). The proportion of any clinically important refractive error was higher in males (61.2%) than in females (58.3%; P<0.0001). From fourteen states that collected information, the proportion of refractive error showed variability in different geographical areas of Mexico. CONCLUSION: Myopia is the most common refractive error in the population studied. This study provides the first data on refractive error in Mexico. Further programs and studies must be developed to address the refractive errors needs of the Mexican population.

Ethanol-induced oxidative stress and acetaldehyde formation in rat mammary tissue: potential factors involved in alcohol drinking promotion of breast cancer.

Recent studies from our laboratory provided evidence that part of the carcinogenic effects of ethanol consumption might be related to its in situ metabolism at cytosolic and microsomal levels, to the mutagen acetaldehyde and to hydroxyl and 1-hydroxyethyl radicals. In this work, we report on our experiments where Sprague-Dawley female rats were exposed to the standard Lieber & De Carli diet for 28 days. We observed: the induction of the (xanthineoxidoreductase mediated) cytosolic and microsomal (lipoxygenase mediated) pathways of ethanol metabolism; promotion of oxidative stress as shown by increased formation of lipid hydroperoxides; delay in the t-butylhydroperoxide induced chemiluminiscence, and a significant decrease in protein sulfhydryls. In addition, the epithelial cells showed ultrastructural alterations consisting of markedly irregular nuclei, with frequent invaginations at the level of the nuclear envelope, condensation of chromatin around the inner nuclear membrane, and marked dilatation of the nuclear pores showing filamentous material exiting to the cytoplasm. In conclusion, the presence in mammary epithelial cells of cytosolic and microsomal pathways of ethanol bioactivation to carcinogenic and to tumorigenic metabolites might play a role in alcohol promotion of breast cancer.

Surveillance of Diarrheagenic Escherichia coli Strains Isolated from Diarrhea Cases from Children, Adults and Elderly at Northwest of Mexico.

Diarrheagenic Escherichia coli (DEC) strains are a main cause of gastrointestinal disease in developing countries. In this study we report the epidemiologic surveillance in a 4-year period (January 2011 to December 2014) of DEC strains causing acute diarrhea throughout the Sinaloa State, Mexico. DEC strains were isolated from outpatients of all ages with acute diarrhea (N = 1,037). Specific DEC pathotypes were identified by PCR-amplification of genes encoding virulence factors. The adhesion phenotype and antibiotic resistance were also investigated. DEC strains were detected in 23.3% (242/1037) of cases. The most frequently DEC strain isolated was EAEC [(12.2%), 126/242] followed by EPEC [(5.1%), 53/242], ETEC [(4.3%), 43/242] DAEC [(1.4%), 15/242], STEC [(0.3%), 3/242], and EIEC [(0.2%), 2/242]. EHEC strains were not detected. Overall DEC strains were more prevalent in children ≤2 years of age with EPEC strains the most common of DEC pathotypes. While ∼65% of EAEC strains were classified as typical variant based on the aggregative adherence to in vitro cultures of HEp-2 cells, a high proportion of EPEC strains was classified as atypical strains. EAEC, EPEC, ETEC, and DAEC strains were distributed in the north, central and south regions of Sinaloa state. Among all DEC strains, >90% were resistant to at least one commonly prescribed antibiotic. Strains were commonly resistant to first-line antibiotics such as tetracycline, ampicillin, and sulfamethoxazole-trimethoprim. Furthermore, more than 80% of DEC isolates were multi-drug resistant and EPEC and DAEC were the categories with major proportion of this feature. In conclusion, in nearly one out of four cases of acute diarrhea in Northwestern Mexico a multi-drug resistant DEC strain was isolated, in these cases EAEC was the most prevalent (52%) pathotype.

Rat liver microsomal and nuclear activation of methanol to hydroxymethyl free radicals.

Recent studies from other laboratories reported that during methanol intoxication lipid peroxidation and protein oxidation in liver occurred. Further, they detected free radicals-PBN adducts in bile and urine of methanol poisoned rats. In this work, we report the presence in liver microsomes and nuclei of NADPH dependent processes of hydroxymethyl (HMet) radical formation. The detection of HMet radicals was performed by GC/MS of the trimethylsilyl derivatives of the PBN (N-tert-butyl-a-phenylnitrone)-radical adducts. The formation of HMet radicals was observed only under nitrogen, in these in vitro conditions. Formation of formaldehyde from methanol was observed in aerobic incubation mixtures containing either microsomes or nuclei but also under nitrogen using microsomes. The latter process was not inhibited by diphenyleneiodonium while the anaerobic microsomal one producing HMet was strongly inhibited by it. This shows that they are independent processes. Results suggest that both, liver nuclei and microsomes are able to generate free radicals during NADPH-mediated methanol biotransformation.

Alcohol drinking and mammary cancer: Pathogenesis and potential dietary preventive alternatives.

Alcohol consumption is associated with an increased risk of breast cancer, increasing linearly even with a moderate consumption and irrespectively of the type of alcoholic beverage. It shows no dependency from other risk factors like menopausal status, oral contraceptives, hormone replacement therapy, or genetic history of breast cancer. The precise mechanism for the effect of drinking alcohol in mammary cancer promotion is still far from being established. Studies by our laboratory suggest that acetaldehyde produced in situ and accumulated in mammary tissue because of poor detoxicating mechanisms might play a role in mutational and promotional events. Additional studies indicated the production of reactive oxygen species accompanied of decreases in vitamin E and GSH contents and of glutathione transferase activity. The resulting oxidative stress might also play a relevant role in several stages of the carcinogenic process. There are reported in literature studies showing that plasmatic levels of estrogens significantly increased after alcohol drinking and that the breast cancer risk is higher in receptor ER-positive individuals. Estrogens are known that they may produce breast cancer by actions on ER and also as chemical carcinogens, as a consequence of their oxidation leading to reactive metabolites. In this review we introduce our working hypothesis integrating the acetaldehyde and the oxidative stress effects with those involving increased estrogen levels. We also analyze potential preventive actions that might be accessible. There remains the fact that alcohol drinking is just one of the avoidable causes of breast cancer and that, at present, the suggested acceptable dose for prevention of this risk is of one drink per day.

Butirato de sodio como agente coadyuvante de la acción radioprotectora de la amifostina / Sodium butyrate as a coadyuvant agent of the radioprotecting action of amifostine / Butirato de sódio como agente coadjuvante da ação radioprotetora da amifostina

Entre los escasos radioprotectores en uso, la amifostina resulta eficaz para reducir la toxicidad aguda inducida por la radiación ionizante. Sin embargo, presenta efectos tóxicos importantes que impiden su uso repetido o en dosis altas. Es necesario entonces desarrollar radioprotectores menos tóxicos, por sí mismos o como coadyuvantes de la amifostina en dosis bajas. Se expusieron ratas Sprague-Dawley a una dosis de rayos X de 6 Gy (cuerpo entero). Se ensayó el butirato de sodio como mitigante luego de una dosis baja de amifostina previa a la irradiación. A distintos tiempos después de la irradiación se realizó el recuento de eritrocitos, leucocitos y la fórmula leucocitaria. Los efectos genotóxicos se evaluaron en leucocitos de sangre mediante el ensayo Cometa. Se realizaron también estudios de supervivencia a 60 días y la evaluación histológica del duodeno e intestino grueso. El efecto del tratamiento resultó moderadamente protector respecto de la recuperación de los valores normales de eritrocitos, leucocitos y la fórmula leucocitaria en los animales sobrevivientes en ambos sexos, así como de los epitelios intestinales y el ADN de los leucocitos. También aumentó significativamente la sobrevida a 60 días. La radioprotección con amifostina en una dosis baja seguida de una mitigación con butirato fue claramente significativa.

Among the few radioprotectors in use, amifostine is effective in reducing the acute toxicity induced by ionizing radiation. However, it has important toxic effects that prevent its repeated use or in high doses. It is necessary then to develop less toxic radioprotectors, by themselves or as adjuvants of amifostine in low doses. Sprague-Dawley rats were exposed to an X-ray dose of 6 Gy (whole body). Sodium butyrate was tested as a mitigant after a low dose of amifostine prior to irradiation. At different times after the irradiation, the erythrocytes, leukocytes and the leukocyte formula were counted. Genotoxic effects were evaluated in blood leukocytes by the Comet assay. Sixty-day survival studies and histological evaluation of the duodenum and large intestine were also performed. The effect of the treatment was moderately protective with respect to the recovery of the normal values of erythrocytes, leukocytes and the leukocyte formula in the surviving animals in both sexes as well as for the intestinal epithelia and leukocytes DNA. It also significantly increased the 60-day survival. The radioprotection with amifostine in a low dose followed by mitigation with butyrate was clearly significant.

Entre os poucos radioprotetores em uso, a amifostina é eficaz na redução da toxicidade aguda induzida pela radiação ionizante. No entanto, tem importantes efeitos tóxicos que impedem seu uso repetido ou em altas doses. É necessário, então, desenvolver radioprotetores menos tóxicos, isoladamente ou como coadjuvantes da amifostina em baixas doses. Ratos Sprague-Dawley foram expostos a uma dose de raios X de 6 Gy (corpo inteiro). O butirato de sódio foi testado como mitigante após uma dose baixa de amifostina antes da irradiação. Em diferentes momentos após a irradiação, os eritrócitos, leucócitos e a fórmula de leucócitos foram contados. Os efeitos genotóxicos foram avaliados em leucócitos de sangue pelo ensaio Cometa. Estudos de sobrevida de 60 dias e avaliação histológica do duodeno e do intestino grosso também foram realizados. O efeito do tratamento resultou moderadamente protetor em relação à recuperação de valores normais de eritrócitos, leucócitos e fórmula leucocitária nos animais sobreviventes em ambos os sexos, bem como protegeu epitélios intestinais e o DNA dos leucócitos. Também aumentou significativamente a sobrevida para 60 dias. A radioproteção com amifostina em baixa dose seguida de uma mitigação com butirato foi claramente significativa.

Acetaldehyde content and oxidative stress in the deleterious effects of alcohol drinking on rat uterine horn.

After alcohol exposure through a standard Lieber and De Carli diet for 28 days, a severe atrophy in the rat uteirne horn was observed, accompanied by significant alterations in its epithelial cells. Microsomal pathway of acetaldehyde production was slightly increased. Hydroxyl radicals were detected in the cytosolic fraction, and this was attributed to participation of xanthine oxidoreductase. They were also observed in the microsomal fraction in the presence of NADPH generating system. No generation of 1-hydroxyethyl was evidenced. The t-butylhydroperoxide-induced chemiluminescence analysis of uterine horn homogenates revealed a significant increase in the chemiluminiscence emission due to ethanol exposure. In the animals repeatedly exposed to alcohol, sulfhydryl content from uterine horn proteins was decreased, but no significant changes were observed in the protein carbonyl content from the same samples. Minor but significant decreasing changes were observed in the GSH content accompanied by a tendency to decrease in the GSH/GSSG ratio. A highly significant finding was the diminished activity content of glutathione peroxidase. Results suggest that acetaldehyde accumulation plus the oxidative stress may play an additional effect to the alcohol-promoted hormonal changes in the uterus reported by others after chronic exposure to alcohol.

Inhibition of rat mammary microsomal oxidation of ethanol to acetaldehyde by plant polyphenols.

We previously reported that the microsomal fraction from rat mammary tissue is able to oxidize ethanol to acetaldehyde, a mutagenic-carcinogenic metabolite, depending on the presence of NADPH and oxygen but not inhibited by carbon monoxide or other cytochrome P450 inhibitors. The process was strongly inhibited by diphenyleneiodonium, a known inhibitor of NADPH oxidase, and by nordihydroguaiaretic acid, an inhibitor of lipoxygenases. This led us to suggest that both enzymes could be involved. With the purpose of identifying natural compounds present in food with the ability to decrease the production of acetaldehyde in mammary tissue, in the present studies, several plant polyphenols having inhibitory effects on lipoxygenases and of antioxidant nature were tested as potential inhibitors of the rat mammary tissue microsomal pathway of ethanol oxidation. We included in the present screening study 32 polyphenols having ready availability and that were also tested against the rat mammary tissue cytosolic metabolism of ethanol to acetaldehyde. Several polyphenols were also able to inhibit the microsomal ethanol oxidation at concentrations as low was 10-50 µM. The results of these screening experiments suggest the potential of several plant polyphenols to prevent in vivo production and accumulation of acetaldehyde in mammary tissue.

Metabolism of ethanol to acetaldehyde by rat uterine horn subcellular fractions.

Controversial studies from others suggested that alcohol intake could be associated with some deleterious effects in the uterus. Not all the effects of alcohol drinking on female reproductive organs can be explained in terms of endocrine disturbances. Deleterious effect of alcohol or its metabolites in situ could also play a role. Accordingly, we found a metabolism of alcohol to acetaldehyde in the rat uterine horn tissue cytosolic fraction mediated by xanthine oxidoreductase, requiring a purine cosubstrate and inhibited by allopurinol. This activity was detected by histochemistry in the epithelium and aldehyde dehydrogenase activity was detected in the muscular layer and in the serosa. There was a microsomal process, not requiring NADPH and of enzymatic nature, oxygen-dependent and inhibited by diethyldithiocarbamate, diphenyleneiodonium and partially sensitive to esculetin and nordihydroguaiaretic acid. The presence of metabolic pathways in the uterine horn able to generate acetaldehyde, accompanied by a low capacity to destroy it through aldehyde dehydrogenase, led to acetaldehyde accumulation in the uterus during ethanol exposure. Results suggest that any acetaldehyde produced in situ or arriving to the uterine horn via blood would remain in this organ sufficiently to have the opportunity to react with critical molecules to cause deleterious effects.