Magnet ingestion knows no borders: A threat for Latin American children.

INTRODUCTION AND AIMS: The ingestion of foreign bodies, such as magnets, is a potentially lethal accident that affects children and is associated with bleeding and gastrointestinal perforation, as well as death. There are no Latin American reports in the literature on cases of magnet ingestion in children. Our aim was to establish whether said ingestion has been seen by pediatric endoscopists and gastroenterologists in Latin America, to determine the scope of that potential threat in their patient populations. MATERIALS AND METHODS: We collected data regarding endoscopies performed on children in Latin America, within the time frame of 2017-2019, through questionnaires that were distributed to pediatric endoscopists at the 2nd World Congress of Gastrointestinal Endoscopy (ENDO 2020). The questionnaires provided information on foreign body location, the presence and number of ingested magnets, and the description of complications and surgical interventions. RESULTS: Our cohort from 12 Latin American countries reported 2,363 endoscopies due to foreign body ingestion, 25 (1.05%) of which were the result of having swallowed one or more magnets. Mean patient age was 5.14 years (SD 2.5) and 10 (40%) of the cases were girls. Three (12%) of the patients presented with severe complications and 2 (8%) cases required surgery. CONCLUSIONS: Our preliminary study suggests that the ingestion of magnets is not common in Latin American countries, but said cases are frequently associated with complications. Constant monitoring of the incidence of such cases is extremely important, so that through education and awareness of those events, life-threatening complications in children can be prevented.

Magnet ingestion knows no borders: A threat for Latin American children. / La ingestión de imanes no conoce fronteras: una amenaza para los niños latinoamericanos.

INTRODUCTION AND AIMS: The ingestion of foreign bodies, such as magnets, is a potentially lethal accident that affects children and is associated with bleeding and gastrointestinal perforation, as well as death. There are no Latin American reports in the literature on cases of magnet ingestion in children. Our aim was to establish whether said ingestion has been seen by pediatric endoscopists and gastroenterologists in Latin America, to determine the scope of that potential threat in their patient populations. MATERIALS AND METHODS: We collected data regarding endoscopies performed on children in Latin America, within the time frame of 2017-2019, through questionnaires that were distributed to pediatric endoscopists at the 2nd World Congress of Gastrointestinal Endoscopy (ENDO 2020). The questionnaires provided information on foreign body location, the presence and number of ingested magnets, and the description of complications and surgical interventions. RESULTS: Our cohort from 12 Latin American countries reported 2,363 endoscopies due to foreign body ingestion, 25 (1.05%) of which were the result of having swallowed one or more magnets. Mean patient age was 5.14years (SD2.5) and 10 (40%) of the cases were girls. Three (12%) of the patients presented with severe complications and 2 (8%) cases required surgery. CONCLUSIONS: Our preliminary study suggests that the ingestion of magnets is not common in Latin American countries, but said cases are frequently associated with complications. Constant monitoring of the incidence of such cases is extremely important, so that through education and awareness of those events, life-threatening complications in children can be prevented.

Prevalencia de Malassezia spp en pacientes con diabetes mellitus tipo 2 de acuerdo con el control glucémico / Prevalence of Malassezia spp in type 2 diabetes mellitus according to glycemic control

Resumen ANTECEDENTES: Malassezia spp es un saprófito de la piel, relacionada con diversas afecciones cutáneas, se ha reportado frecuencia elevada en pacientes con inmunosupresión. OBJETIVO: determinar la prevalencia de Malassezia spp en individuos con diabetes mellitus tipo 2 de acuerdo con el control glucémico. MATERIAL Y MÉTODO: estudio abierto, observacional, descriptivo y transversal, efectuado en pacientes voluntarios que participaron en la 24ª Carrera Nacional del Paciente con Diabetes el 15 de octubre de 2016 en la Ciudad de México, en quienes se realizó toma de glucemia capilar preprandial y hemoglobina glicosilada, así como pesquisa de Malassezia spp mediante frotis de la región malar, teñido con azul de metileno. RESULTADOS: se incluyeron 49 pacientes con diabetes mellitus tipo 2; hubo predominio de 31 pacientes sin buen control glucémico (67%) en comparación con 16 pacientes controlados (33%). Los frotis con levaduras escasas (+) estuvieron presentes en 21 (59%) pacientes sin control y en 7 (41%) pacientes con control; los frotis con cantidad de levaduras moderada (++) se observaron en 7 (74%) pacientes sin control y en 5 (26%) pacientes con control; los frotis con levaduras abundantes estuvieron presentes en 7 (63%) pacientes sin control y en 2 (37%) pacientes con control. CONCLUSIÓN: en nuestro estudio la prevalencia de Malassezia spp en pacientes con diabetes mellitus tipo 2 fue del 100%, con menor número de levaduras en los que tenían control glucémico adecuado, lo que puede indicar que la posibilidad de tener esta levadura aumenta con el descontrol glucémico y probablemente denota el grado de inmunosupresión en estos pacientes.

Abstract BACKGROUND: Malassezia spp is a saprophyte of the skin, related to diverse cutaneous affections, and has been reported a high frequency in patients with immunosuppression. OBJECTIVE: To determine the prevalence of Malassezia spp in individuals with type 2 diabetes mellitus according to glycemic control. MATERIAL AND METHOD: An open, observational, descriptive and cross-sectional study was performed in volunteer patients who participated in the 24th National March of the Patient with Diabetes in Mexico City on October 15, 2016; where preprandial capillary glycemia and glycosylated hemoglobin were taken. We took a scraping of the malar region skin to find Malassezia spp, smears stained with methylene blue. RESULTS: A total of 49 patients with type 2 diabetes mellitus were included; there were a predominance of 31 patients without glycemic control (67%) in comparison with 16 controlled patients (33%). Smears with low yeast (+) were present in 21 (59%) uncontrolled patients and in 7 (41%) controlled patients; smears with a moderate amount of yeast (++) were present in 7 (74%) uncontrolled patients and in 5 (26%) controlled patients; smears with abundant yeasts were present in 7 (63%) uncontrolled patients and in 2 (37%) controlled patients. CONCLUSION: In our study the prevalence of Malassezia spp in patients with type 2 diabetes mellitus was of 100%, with a lower number of yeasts in patients with adequate glycemic control; this can indicate that the possibility of presenting this yeast increases with bad glycemic control and probably denotes the degree of immunosuppression in these patients.

Real-time parameter estimation of Zika outbreaks using model averaging.

Early prediction of the final size of any epidemic and in particular for Zika disease outbreaks can be useful for health authorities in order to plan the response to the outbreak. The Richards model is often been used to estimate epidemiological parameters for arboviral diseases based on the reported cumulative cases in single- and multi-wave outbreaks. However, other non-linear models can also fit the data as well. Typically, one follows the so called post selection estimation procedure, i.e., selects the best fitting model out of the set of candidate models and ignores the model uncertainty in both estimation and inference since these procedures are based on a single model. In this paper we focus on the estimation of the final size and the turning point of the epidemic and conduct a real-time prediction for the final size of the outbreak using several non-linear models in which these parameters are estimated via model averaging. The proposed method is applied to Zika outbreak data in four cities from Colombia, during the outbreak ocurred in 2015-2016.

DNA Barcoding of an Assembly of Montane Andean Butterflies (Satyrinae): Geographical Scale and Identification Performance.

DNA barcoding is a technique used primarily for the documentation and identification of biological diversity based on mitochondrial DNA sequences. Butterflies have received particular attention in DNA barcoding studies, although varied performance may be obtained due to different scales of geographic sampling and speciation processes in various groups. The montane Andean Satyrinae constitutes a challenging study group for taxonomy. The group displays high richness, with more of 550 species, and remarkable morphological similarity among taxa, which renders their identification difficult. In the present study, we evaluated the effectiveness of DNA barcodes in the identification of montane Andean satyrines and the effect of increased geographical scale of sampling on identification performance. Mitochondrial sequences were obtained from 104 specimens of 39 species and 16 genera, collected in a forest remnant in the northwest Andes. DNA barcoding has proved to be a useful tool for the identification of the specimens, with a well-defined gap and producing clusters with unambiguous identifications for all the morphospecies in the study area. The expansion of the geographical scale with published data increased genetic distances within species and reduced those among species, but did not generally reduce the success of specimen identification. Only in Forsterinaria rustica (Butler, 1868), a taxon with high intraspecific variation, the barcode gap was lost and low support for monophyly was obtained. Likewise, expanded sampling resulted in a substantial increase in the intraspecific distance in Morpho sulkowskyi (Kollar, 1850); Panyapedaliodes drymaea (Hewitson, 1858); Lymanopoda obsoleta (Westwood, 1851); and Lymanopoda labda Hewitson, 1861; but for these species, the barcode gap was maintained. These divergent lineages are nonetheless worth a detailed study of external and genitalic morphology variation, as well as ecological features, in order to determine the potential existence of cryptic species. Even including these cases, DNA barcoding performance in specimen identification was 100% successful based on monophyly, an unexpected result in such a taxonomically complicated group.

Introducción precoz de sustitutos de lactancia materna e incidencia de lactancia materna exclusiva al mes de vida / Breast milk substitutes at one month of life and breastfeeding suspension risk

Healthy term newborn feeding choice at the Maternity Ward may determine exclusive breastfeeding (EB) duration. Objective: Determine prospectively if early introduction of breast milk substitutes (BMS) or other liquids in healthy term newborns is associated to a reduction of EB incidence at 1 month of age. Methods: Concurrent cohort study of 211 healthy term neonates born in Hospital Clínico Universidad Católica during October 2007-June 2007, 108 non-supplemented and 103 supplemented with milk formula or dextrose 5 percent during the time they stayed at the Maternity Ward. Crude and adjusted risk of EB cessation between both groups was estimated at 1 month of age. Results: One month after birth, 40/100 (40.0 percent) of supplemented newborns and 26/101 (25.7 percent) non-supplemented newborns were not receiving exclusive breastfeeding (crude RR =1.55 (CI95 percent 1.03-2.34)). Adjusted by maternal characteristics (age, education, breastfeeding experience, education in breastfeeding, EB time projection and paternal support) and newborn characteristics (type of delivery and birth weight), EB cessation risk was 55 percent higher in supplemented neonates (adjusted RR = 1.55, CI95 percent 1.01-2.35). Conclusion: Early supplementation in healthy term newborns with BMS is associated to a higher risk of EB cessation at 1 month of age.

Introducción: La forma de alimentación de un recién nacido de término (RNT) durante su estadía en la Maternidad puede condicionar la duración de la lactancia materna exclusiva (LME). Objetivo: Determinar prospectivamente si la introducción precoz de SLM (sustitutos de lactancia materna) u otros líquidos a RNT sanos se asocia a una reducción de la incidencia de LME al mes de vida. Métodos: Estudio de cohorte concurrente. Se conformó una cohorte de 211 RNT sanos cuyo parto fue atendido en la Maternidad del Hospital Clínico Universidad Católica en el período octubre 2006-junio 2007, 108 no-suplementados y 103 suplementados con fórmula láctea o suero glucosado al 5 por ciento durante su estadía en la Maternidad. Se estimó el riesgo crudo de cesación de LME al mes de vida entre los grupos no-suplementado vs suplementado, y ajustado por diversas variables confundentes. Resultados: Transcurrido un mes de vida, 40/100 (40,0 por ciento) recién nacidos suplementados y 26/101 (25,7 por ciento) recién nacidos no-suplementados habían dejado de recibir LME, siendo el RR crudo = 1,55 (IC95 por ciento 1,03-2,34). Ajustado por características maternas (edad, educación, experiencia previa de lactancia, educación en lactancia, proyección LME y apoyo paterno) y del recién nacido (vía de parto y peso de nacimiento), el riesgo de cesación de LME al mes de vida fue 55 por ciento mayor en los RNT suplementados vs. no-suplementados (RR ajustado = 1,54; IC95 por ciento 1,01-2,35). Conclusión: La suplementación precoz de RNT sanos con SLM asocia a un mayor riesgo de cese de LME al mes de vida.

Source analysis of alpha rhythm reactivity using LORETA imaging with 64-channel EEG and individual MRI.

Conventional EEG and quantitative EEG visual stimuli (close-open eyes) reactivity analysis have shown their usefulness in clinical practice; however studies at the level of EEG generators are limited. The focus of the study was visual reactivity of cortical resources in healthy subjects and in a stroke patient. The 64 channel EEG and T1 magnetic resonance imaging (MRI) studies were obtained from 32 healthy subjects and a middle cerebral artery stroke patient. Low Resolution Electromagnetic Tomography (LORETA) was used to estimate EEG sources for both close eyes (CE) vs. open eyes (OE) conditions using individual MRI. The t-test was performed between source spectra of the two conditions. Thresholds for statistically significant t values were estimated by the local false discovery rate (lfdr) method. The Z transform was used to quantify the differences in cortical reactivity between the patient and healthy subjects. Closed-open eyes alpha reactivity sources were found mainly in posterior regions (occipito-parietal zones), extended in some cases to anterior and thalamic regions. Significant cortical reactivity sources were found in frequencies different from alpha (lower t-values). Significant changes at EEG reactivity sources were evident in the damaged brain hemisphere. Reactivity changes were also found in the "healthy" hemisphere when compared with the normal population. In conclusion, our study of brain sources of EEG alpha reactivity provides information that is not evident in the usual topographic analysis.

[Accidental genital myiasis by Eristalis tenax]. / Miasis genital accidental por Eristalis tenax.

Myiasis is a parasitic infestation of human or animal skin, necrotic tissues and natural cavities by fly larvae or pupa. In this paper we will describe the case of a 27 years old woman, asymptomatic, that spontaneously eliminated from her vagina two Eristalis tenax larvae, a worldwide distributed fly specie, classified as an accidental myiasis agent. The patient lived in an urban area, she had low socioeconomic status and she had the antecedent record of use of intravaginal vegetables as sexual stimulator. Analyzing the case and the references, we concluded the patient had an accidental infestation by E. tenax, being the vaginal introduction of vegetables the most probable mechanism of transmission. This kind of infestation has not been communicated in the literature. Also, this is the first documented case of E. tenax myiasis in Chile.

Miasis genital accidental por Eristalis tenax / Accidental genital myiasis by Eristalis tenax

Myiasis is a parasitic infestation of human or animal skin, necrotic tissues and natural cavities by fly larvae or pupa. In this paper we will describe the case of a 27 years oíd woman, asymptomatic, that spontaneously eliminated from her vagina two Eristalis tenax larvae, a worldwide distributed fly specie, classified as an accidental myiasis agent. The patient lived in an urban área, she had low socioeconomic status and she had the antecedent record of use of intravaginal vegetables as sexual stimulator. Analyzing the case and the references, we concluded the patient had an accidental infestation by E. tenax, being the vaginal introduction of vegetables the most probable mechanism of transmission. This kind of infestation has not been communicated in the literature. Also, this is the first documented case of E. tenax myiasis in Chile.

Las miasis son infestaciones parasitarias de humanos o animales por larvas de mosca que infestan piel, tejidos necróticos y cavidades naturales. Presentamos el caso de una mujer de 27 años, asintomática, que eliminó espontáneamente por vía vaginal larvas de Eristalis tenax, una especie de mosca ampliamente distribuida en el mundo, la que es clasificada como agente de miasis accidental. La paciente residía en un área urbana de nivel socioeconómico bajo y entregaba como antecedente el uso de vegetales intravaginales como estimulante sexual. Analizando el caso descrito y la bibliografía existente, concluimos que la paciente presentó una infestación accidental por E. tenax, siendo el mecanismo más probable de transmisión la introducción vaginal de vegetales. Este mecanismo no ha sido comunicado previamente en la literatura. Además, este es el primer caso de miasis por E. tenax documentado en Chile.

Towards active community participation in dengue vector control: results from action research in Santiago de Cuba, Cuba.

Community participation is advocated as essential for attaining effective dengue prevention, but knowledge of how to foster this is limited. In Santiago de Cuba, multiple small task forces were created at the neighbourhood level that included all stakeholders in the control of Aedes aegypti. The task forces assessed the perceived needs and elaborated action plans to promote specific behavioural change and to reduce environmental risks through social communication strategies and intersectoral local government activities. We monitored five dimensions of the participation process and assessed behavioural and environmental results and entomological outcomes. Participation was weak to good. At the household level, uncovered water storage containers decreased from 49.3% to 2.6% between 2000 and 2002, and removing larvicide from them dropped from 45.5% to 1%. There was a reduction of 75% in the absolute number of positive containers and a significant decrease from 1.23% to 0.35% in the house index. Local task forces, in which the interests of householders as well as vector control workers are directly represented, can lead to effective government-community partnerships that resolve problems of mutual concern.

Programa de alfabetización informacional para los usuarios potenciales internos de la biblioteca del Instituto de Neurología y Neurocirugía de Cuba / Informational Schooling Program for Internal Potential Users of the Library of the Cuban Neurology and Neurosurgery Institute

Con el objetivo de desarrollar un programa de alfabetización, se estudiaron las habilidades informacionales de los usuarios potenciales internos de la biblioteca del Instituto de Neurología y Neurocirugía de Cuba. El programa, que busca enriquecer la cultura informacional de los usuarios, se propone desarrollar 5 clases básicas de habilidades: reconocimiento de las necesidades de información, acceso a la información, evaluación de la información, uso de la información; así como el uso y acceso a la información de manera ética.

In order to develop a literacy program, the information skills of the potential internal users of the library of the Cuban Neurology and Neurosurgery Institute were studied. The program, aimed at enriching the information culture of the users, intends to develop five basic types of skills: recognition of the information needs, access to information, information evaluation, information use, and the use of and the access to information in an ethical way.

Aportes de las doulas a la obstetricia moderna / Contributions of the doulas to modern obstetrics

Este artículo tiene como objetivo realizar una revisión de la evidencia disponible en relación con la presencia de una "doula" durante el parto. Llamamos "doula" a una mujer que acompaña a otra durante el trabajo de parto y parto, brindando apoyo emocional continuo durante este periodo. Desde hace 25 años se han realizado múltiples estudios randomizados controlados para evaluar el efecto del acompañamiento de una "doula" en el parto. Los resultados son sorprendentes, significativos y consistentes en relación con aspectos obstétricos como menores tasas de partos operatorios (cesáreas y fórceps), menor necesidad de uso de analgesia durante el trabajo de parto y parto, menor duración del trabajo de parto. También se han evaluado aspectos psicológicos como mejor percepción de la vivencia del parto, mayor autoestima y menores tasas de depresión postparto e incluso se ha visto que ayuda a mejorar el apego madre hijo y las tasas de lactancia materna. Dado los resultados de esta revisión, creemos que es de gran importancia establecer iniciativas para extender esta práctica.

Salvinorin C, a new neoclerodane diterpene from a bioactive fraction of the hallucinogenic Mexican mint Salvia divinorum.

Salvinorin C (1), a minor component from a biologically active TLC fraction, was isolated from the leaves of the Mexican mint Salvia divinorum. Its structure was elucidated on the basis of extensive proton and C-13 NMR experiments, as well as by comparison of the NMR data with those of the mono- and diacetate derivatives 5-7 of the major NaBH(4)-reduction product of salvinorin A (2). [structure: see text]

Epidemiologic studies on Dengue in Santiago de Cuba, 1997.

A small, isolated outbreak of dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) due to dengue virus type 2 (DEN-2) was documented in Santiago de Cuba on the island of Cuba beginning in January 1997. There were 205 DHF/DSS cases, all in persons older than age 15 years. All but three had evidence of a prior dengue infection, with the only known opportunity being the islandwide dengue virus type 1 (DEN-1) epidemic of 1977-1979. Virtually complete clinical and laboratory surveillance of overt disease was achieved. From December 1997 to January 1998, a random, age-stratified serum sample was obtained from 1,151 persons in 40 residential clusters in Santiago. Sera were tested for DEN-1 and DEN-2 neutralizing antibodies. The prevalence of DEN-2 antibodies in children age 15 years and under, born after the 1981 DEN-2 epidemic, was taken as the 1997 DEN-2 infection rate. This was adjusted slightly to accommodate observed cases, resulting in an estimated infection rate of 4.3%. Dengue fever and DHF/DSS attack rates were calculated from estimated total primary and secondary DEN-2 infections. Only 3% of 13,116 primary infections were overt. The DHF/DSS attack rate for adults of all ages was 420 per 10,000 secondary DEN-2 infections.

[Training of sensorial panels consisting of children]. / Entrenamiento de paneles sensoriales constituidos por niños.

In the development of food products for children, it is advisable to establish the characteristics of the product with groups of children that represent the target population. To ensure the success of the products, the quality and hedonic satisfaction expectatives must be considered. In order to accomplish this premises, a group of children under the Program of Complementary Feeding of the Health Ministry--was selected and trained. The project was developed with a group of 33 children ages 9 to 12 years--from the Republica of Colombia School of Santiago, whose parents agreed and supported the participation of their children in this project. The first step was teaching the technics and methodology of Sensory Evaluation, and increasing their sensitivity. After the 8 programmed sessions, those children who met the minimal requirements for a training group were chosen. The second step was performed during 12 sessions, working with 14 children. The training was aimed at the development of the vocabulary to describe quality and defects, ranking tests, discriminative tests and the use of different scales. Tests to verify reliability, veracity and reproducibility of judgements (p < 0.05) were carried out. The trained group was able to assess different meals of the Program. The obtained results allowed to propose the improvement of some quality criteria of the Program meals.

[Epidemiology of dengue and hemorrhagic dengue in Santiago, Cuba 1997]. / La epidemiología del dengue y del dengue hemorrágico en Santiago de Cuba, 1997.

A dengue epidemic that Cuba reported in 1997 registered more than 500,000 cases of dengue fever produced by viral serotype 1. In 1981, there was an epidemic of dengue hemorrhagic fever produced by serotype 2 of the virus. This time 344,203 clinical cases were reported, 10,312 of which were severe cases of hemorrhagic fever that led to 158 fatalities (101 of them among children). The reintroduction of dengue, and specifically of dengue viral serotype 2 (Jamaica genotype), was quickly detected in January 1997 through an active surveillance system with laboratory confirmation of cases in the municipality of Santiago de Cuba, in the province of the same name. The main epidemiological features of this outbreak are reported in this paper. A total of 3,012 cases were reported and serologically confirmed. These included 205 cases classified as dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS), 12 of which were case fatalities (all among adults). Secondary infection with dengue virus was one of the most important risk factors for DHF/DSS. Ninety-eight percent of the DHF/DSS cases and 92% of the fatal cases had contracted a secondary infection. It was the first time dengue hemorrhagic fever was documented as a secondary infection 16 to 20 years after initial infection. Belonging to the white racial group was another important risk factor for DHF/DSS, as had been observed during the 1981 epidemic. During the most recent epidemic it was demonstrated that the so called "fever alert" is not useful for early detection of an epidemic. Measures taken by the country's public health officials prevented spread of the epidemic to other municipalities plagued by Aedes aegypti.

Prevalencia de anticuerpos anti islotes pancreáticos en 1.021 parientes de diabéticos tipo 1 / Prevalence of anti pancreatic islet antibodies among 1.021 relatives of type 1 diabetic patients

Background: An immunological damage of beta cells in the islets of Langerhans, plays a role in the pathogenesis of type 1 diabetes. Recently, the identification of individuals in pre clinical phase and with high risk of developing type 1 diabetes, has become possible by means of the detection of immune markers such as islet cell antibodies (ICA) and the measurement of first phase response of insulin (FPRI). Subjects and methods: We studied 1,021 first degree relatives of type 1 diabetics, aged 4 to 35 years. ICA were measured using poly-IgG peroxidase in sections of human pancreas. In those subjects with positive ICA and normal oral glucose tolerance test, the FPRI was measured. FPRI was defined as the sum of insulinemias at minutes 1 and 3 after a three minutes 0.5 g/kg glucose load. Results: Thirty subjects were ICA (+), defined as having more than 20 juvenile diabetes foundation units (prevalence of 2.9 percent). No differences in age, sex and closeness of familial relationship was found between ICA (+) and ICA (-) individuals. FPRI was measured in 24 subjects with normal oral glucose tolerance test and was normal in five. Seventeen subjects had a decreased response (between percentiles 1 and 5) and two had a response below percentile 1. No relationship between ICA levels and FPRI was found. Conclusions: The early detection of populations at risk of developing type 1 diabetes should be regarded as an important tool to better understand the natural history of the disease and to develop preventive programs in the future

The descrease of the in vitro proliferative response of zinc-treated stressed mice's thymic lymphocytes.

Prolonged stimulation of newborn mice by intraperitoneal injections with inactivated staphylococci induces a chronic neonatal inflammatory reaction and an associated oxidative-stress response. The chronically stimulated animals exhibit anorexy. show a reduction in their body weight and undergo a depression in both antibody synthesis andin vitro proliferativc response of Con A-stimulated splenic T-lymphocytes. These stressed animals also develop adrenal hyperplasia, hypozincamia and thymic hypoplasia. Despite this stress-mediated thymic involution, Con-A stimulated T-lymphocytes from thymus displayed increased theirin vitro proliferative response. Results of the present work show that intramuscular injections of zinc acetate in stressed mice, one single dose (5 microg) every other day for two weeks, reduce both the zinc concentration in the thymus gland and thein vitro proliferative response of their Con A-stimulated T-lymphocytes. The results suggest that prophylactic administration of zinc can have benefical consequences on the immunity of chronically stressed mice.