Maternal dietary patterns and acute leukemia in infants: results from a case control study in Mexico.

Background: Childhood cancer is the leading cause of disease-related mortality among children aged 5-14 years in Mexico, with acute leukemia being the most common cancer among infants. Examining the overall dietary patterns allows for a comprehensive assessment of food and nutrient consumption, providing a more predictive measure of disease risk than individual foods or nutrients. This study aims to evaluate the association between maternal dietary patterns during pregnancy and the risk of acute leukemia in Mexican infants. Methods: A hospital-based case-control study was conducted, comparing 109 confirmed acute leukemia cases with 152 age-matched controls. All participants (≤24 months) were identified at hospitals in Mexico City between 2010 and 2019. Data on a posteriori dietary patterns and other relevant variables were collected through structured interviews and dietary questionnaires. Multivariate logistic regression was employed to estimate the association between maternal dietary patterns during pregnancy and the risk of acute leukemia in infants. Results: The "Balanced & Vegetable-Rich" pattern, characterized by a balanced consumption of various food groups and higher vegetable intake, exhibited a negative association with acute leukemia when compared to the "High Dairy & Cereals" Pattern (adjusted odds ratio [OR] = 0.51; 95% confidence interval [CI]: 0.29, 0.90). We observed that mothers who gave birth to girls and adhered to a healthy dietary pattern during pregnancy exhibited significantly lower odds of their children developing AL compared to those who gave birth to boys [OR = 0.32 (95% CI 0.11, 0.97)]. Our results underscore the significance of maternal nutrition as a modifiable factor in disease prevention and the importance of prenatal health education.

Ultrasonographic findings in the epididymis of pediatric patients with testicular torsion.

INTRODUCTION: Although grayscale ultrasound and color Doppler ultrasound characteristics of the torsed testis are well established in the literature, less is known about its anatomic partner: the epididymis. OBJECTIVE: The purpose of this study was to describe the ultrasound characteristics of the epididymis in pediatric patients with testicular torsion, and to describe their potential role as prognostic criteria for testicular salvage outcomes. STUDY DESIGN: During a retrospective review of 217 pediatric patients with acute testicular torsion during 2009-2016, morphological features of the epididymis from scrotal ultrasounds (size, parenchymal characteristics, and vascular flow of both epididymis heads), as well as patient demographics, time duration, surgical outcomes, histopathology results, and follow-up periods were analyzed. RESULTS: Mean epididymis size and twisting degree were significantly higher in the torsed testes than in the contralateral epididymis (P < 0.001) (Summary table). Cystic structures in the epididymis were identified: a higher number of cysts was associated with testicular non-viability (P = 0.025) and higher twisting degree (P = 0.017). Histopathologic examination showed that these spaces were infiltrated connective tissue most likely formed by venous congestion and vessel rupture. DISCUSSION: Scrotal ultrasound can provide information on testicular morphology and viability, as well as morphological changes in the epididymis over time in pediatric patients with testicular torsion. These findings may provide potential prognostic information regarding testicular viability, as a higher number of cystic spaces in the epididymis was associated with a higher rate of testicular non-viability and a higher twisting degree. In addition, the epididymis size (volume) can change during the time course of the ischemic state. CONCLUSIONS: This was the first study to describe and analyze epididymis ultrasound findings in pediatric patients with testicular torsion and to correlate them with testicular salvage outcomes. Further prospective studies are needed to determine the role of epididymis ultrasound findings as a potential pre-operative prognostic tool.

EBV, HCMV, HHV6, and HHV7 screening in bone marrow samples from children with acute lymphoblastic leukemia.

Acute lymphoblastic leukemia (ALL) is the most common cancer in childhood worldwide and Mexico has reported one of the highest incidence rates. An infectious etiology has been suggested and supported by epidemiological evidences; however, the identity of the involved agent(s) is not known. We considered that early transmitted lymphotropic herpes viruses were good candidates, since transforming mechanisms have been described for them and some are already associated with human cancers. In this study we interrogated the direct role of EBV, HCMV, HHV6, and HHV7 human herpes viruses in childhood ALL. Viral genomes were screened in 70 bone marrow samples from ALL patients through standard and a more sensitive nested PCR. Positive samples were detected only by nested PCR indicating a low level of infection. Our result argues that viral genomes were not present in all leukemic cells, and, hence, infection most likely was not part of the initial genetic lesions leading to ALL. The high statistical power of the study suggested that these agents are not involved in the genesis of ALL in Mexican children. Additional analysis showed that detected infections or coinfections were not associated with prognosis.

Artificial Neural Network for predicting biosorption of methylene blue by Spirulina sp.

An artificial neural network (ANN) was used to predict the biosorption of methylene blue on Spirulina sp. biomass. Genetic and anneal algorithms were tested with different quantity of neurons at the hidden layers to determine the optimal neurons in the ANN architecture. In addition, sensitivity analyses were conducted with the optimised ANN architecture for establishing which input variables (temperature, pH, and biomass dose) significantly affect the predicted data (removal efficiency or biosorption capacity). A number of isotherm models were also compared with the optimised ANN architecture. The removal efficiency or the biosorption capacity of MB on Spirulina sp. biomass was adequately predicted with the optimised ANN architecture by using the genetic algorithm with three input neurons, and 20 neurons in each one of the two hidden layers. Sensitivity analyses demonstrated that initial pH and biomass dose show a strong influence on the predicted removal efficiency or biosorption capacity, respectively. When supplying two variables to the genetic algorithm, initial pH and biomass dose improved the prediction of the output neuron (biosorption capacity or removal efficiency). The optimised ANN architecture predicted the equilibrium data 5,000 times better than the best isotherm model. These results demonstrate that ANN can be an effective way of predicting the experimental biosorption data of MB on Spirulina sp. biomass.

Quantitative analysis of liver peroxisomes in rats intoxicated with peroxisomicine-A1.

Peroxisomes are single-membrane-bound organelles present in almost all eukaryotic cells. Hypolipidemic agents such as clofibrate, herbicides and plasticizers induce an increase in the number and size of peroxisomes from mammalian cells. However, there is no evidence of drugs causing a decrease in the number of these organelles. In this paper, we report the effect in vivo of toxin T-514 extracted from the plant Karwinskia humboldtiana, now re-named peroxisomicine-A1, on hepatic peroxisomes from rats intoxicated with this compound. Rats were treated with a single dose of 25 mg/kg of peroxisomicine-A1 and at different times were killed by decapitation. For the peroxisomal counting, liver tissue sections from control and treated rats were processed for the localization of catalase in peroxisomes. The results of the quantitative analysis demonstrated a significant decrease in the number of liver peroxisomes from rats intoxicated with peroxisomicine-A1. This finding suggests that peroxisomicine-A1 as in yeast, causes a damage to mammalian peroxisomes. The diminution in the number of peroxisomes could be a consequence of damage to the organelle, which is further removed by an autophagic process.

Studies on the effect of peroxisomicine on catalase activity in albino mice.

Peroxisomicine is a toxic compound isolated from plants of the genus Karwinskia (Rhamnaceae). This toxin produces irreversible and selective damage to the peroxisomes of yeast cells in vivo. Peroxisomicine also inhibits catalase activity in vitro, when using purified enzyme. This paper reports on the effect of peroxisomicine on liver catalase in tissue fragments, in situ, as well as in mice intoxicated with peroxisomicine, in vivo. The catalase activity was determined by biochemical and histochemical methods. In contrast with the reported findings in vitro, the results demonstrate that there is no inhibition of the activity of tissue catalase, and suggest that catalase in situ and in vivo is protected against the inhibitory effect of peroxisomicine by an unknown factor.

Linguistic influences on the auditory processing of speech by children with normal hearing or hearing impairment.

OBJECTIVE: The accurate perception of speech requires the processing of multidimensional information. The aim of this research was to examine linguistic influences on the auditory processing of speech in the presence of childhood hearing impairment. DESIGN: The processing interactions characterizing the linguistic and auditory dimensions were assessed with a pediatric auditory analog of the Pomerantz task (Pomerantz, Pristach, & Carson, 1989). The task yields measures of Stroop interference, the effect of irrelevant semantic content, and of Garner interference, the effect of irrelevant linguistic variability (Stroop, 1935; Garner, 1974a). Subjects were 100 normal-hearing children and 60 hearing-impaired children. Subjects were required to attend selectively to the auditory (voice-gender) dimension and to ignore the linguistic dimension. The logic of the task is that performance for the voice-gender dimension will be unaffected by what is happening on the irrelevant dimension if the dimensions are processed independently. On the other hand, if the dimensions are not processed independently, subjects will not be able to attend selectively and performance for the relevant dimension will be affected by what is happening on the to-be-ignored dimension. RESULTS: Both the normal-hearing and hearing-impaired children showed auditory Stroop and Garner interference effects, indicating that the auditory and linguistic dimensions were not processed independently by either group. However, the linguistic dimension exerted significantly less influence on auditory processing in the presence of childhood hearing impairment. Whereas normal-hearing children had remarkable difficulty ignoring irrelevant word input and focusing exclusively on voice-gender, hearing-impaired children were relatively successful at ignoring the linguistic dimension and attending selectively to the auditory dimension of speech. This result implies that the linguistic dimension of auditory speech input may have a different weight or processing value in the presence of childhood hearing impairment. It may be the case that hearing-impaired children encode spoken speech disproportionately in terms of the auditory dimensions, which offer important supplementary aids to speechreading. Further research is being carried out to address these possibilities. CONCLUSIONS: Both Stroop and Garner interference were significantly reduced in the presence of childhood hearing impairment. This pattern of results suggests that multidimensional speech processing is carried out in a less stimulus-bound manner in the presence of childhood hearing impairment.

Developmental trends in the interaction between auditory and linguistic processing.

The developmental course of multidimensional speech processing was examined in 80 children between 3 and 6 years of age and in 60 adults between 20 and 86 years of age. Processing interactions were assessed with a speeded classification task (Garner, 1974a), which required the subjects to attend selectively to the voice dimension while ignoring the linguistic dimension, and vice versa. The children and adults exhibited both similarities and differences in the patterns of processing dependencies. For all ages, performance for each dimension was slower in the presence of variation in the irrelevant dimension; irrelevant variation in the voice dimension disrupted performance more than irrelevant variation in the linguistic dimension. Trends in the degree of interference, on the other hand, showed significant differences between dimensions as a function of age. Whereas the degree of interference for the voice-dimension-relevant did not show significant age-related change, the degree of interference for the word-dimension-relevant declined significantly with age in a linear as well as a quadratic manner. A major age-related change in the relation between dimensions was that word processing, relative to voice-gender processing, required significantly more time in the children than in the adults. Overall, the developmental course characterizing multidimensional speech processing evidenced more pronounced change when the linguistic dimension, rather than the voice dimension, was relevant.

Fever induced by Escherichia coli or intrahypothalamic prostaglandin E2 enhances interferon-gamma synthesis.

We previously showed that hyperthermia induced in rhesus monkeys (Macaca mulatta) by forced passive heating "primes" the peripheral lymphocyte population for increased synthesis of interferon-gamma (IFN-gamma). It was not clear whether these data could be extrapolated to the physiological response in naturally occurring fever. Therefore, in the current experiments, the temperature of rhesus monkeys was raised either by systemic injection of killed Escherichia coli or by intrahypothalamic administration of prostaglandin E2. Mononuclear cells collected subsequently from such monkeys produced more IFN-gamma in response to stimulation with mitogens than cells from control monkeys. Direct administration of IFN-alpha, -beta, or -gamma to the hypothalamus did not affect the body temperature of rhesus monkeys.

Effects of atropine and pyridostigmine in heat-stressed patas monkeys.

The effects of a single intramuscular atropine injection (0.03 mg.kg-1) and a chronic oral pyridostigmine treatment (0.4 mg.kg-1, 3 times/day over a period of 7 d) on the thermoregulatory effector responses of unanesthetized patas monkeys were investigated using indirect calorimetry. The effects of atropine treatment on the thermoregulatory effector responses of patas monkeys exposed to 25 degrees and 35 degrees C were qualitatively similar but quantitatively greater at 35 degrees C. At 35 degrees C atropine decreased sweating (Esw) 52%, increased rectal temperature (Tre), mean skin temperature (Tsk), metabolic rate (MR), and whole body conductance (K), and elicited a consistent 11% increase in heart rate (HR). Daily oral pyridostigmine treatment to patas monkeys produced a significant 25-30% drop in serum cholinesterase activity with no chronic effects on thermoregulatory or cardiovascular functions. The acute effects of oral pyridostigmine treatment in this species included transient 12% and 15% decreases in MR and HR, respectively, and a transient 25% increase in Esw. The latter was associated with significant acute reductions in Tre and Tsk which lasted at least 120 min following pyridostigmine administration. It is concluded that the patas monkey is an excellent animal model for studies to evaluate the effects of neuroactive agents on thermoregulatory and other physiological functions which are difficult, if not impossible, to perform on humans.

Hyperthermia in humans enhances interferon-gamma synthesis and alters the peripheral lymphocyte population.

Induction of hyperthermia (39 degrees C) in human volunteers by immersion in warm water (41-45 degrees C) rapidly alters the cell populations in the peripheral blood. In addition to granulocytosis, there is an alteration of the normal ratios among T-lymphocyte subsets. Following in vitro mitogen stimulation, lymphocytes from hyperthermic individuals produce as much as 10-fold more interferon-gamma (IFN-gamma) than cells withdrawn at basal core temperatures from the same individuals. A temperature threshold of 39 degrees C for this response suggests potential relevance to fever. No change was noted in the activity of the macrophage population. The possible involvement of interleukin-2 (IL-2) in this enhanced production is discussed. No changes were noted in the circulating levels of IFN-gamma.

In vivo hyperthermia enhances plasma antiviral activity and stimulates peripheral lymphocytes for increased synthesis of interferon-gamma.

The effect of in vivo hyperthermia on plasma interferon (IFN) activity and on the induction of IFN-gamma by phytohemagglutinin (PHA) or staphylococcal enterotoxin B (SEB) in isolated leukocyte cultures was investigated. Adult rhesus monkeys (Macaca mulatta) were placed in a climatic chamber maintained at 45 degrees C until their core body temperatures increased 2 degrees C above control levels. Peripheral blood samples were withdrawn both prior to core temperature elevation and at the time of peak body temperature. Plasma IFN-alpha increased slightly from a control value of 12 U/ml to 16 U/ml at the elevated core temperature. However, this alteration of plasma IFN levels appears to be a complex process that includes the loss of certain circulating IFN-alpha subtypes and the influx of acid-labile (Type II) IFN-alpha. Additionally, a non-IFN antiviral factor present in the plasma was elevated 10-fold at the higher body temperature. When mononuclear cells were isolated and cultured at 37 degrees C in the presence of PHA or SEB, those cells isolated from animals at the peak of body temperature showed a 4- to 16-fold increase in IFN-gamma activity relative to cells isolated from the same animal before the temperature increase. Similar results were obtained with cells isolated when fever was induced by the systemic injection of nonviable Escherichia coli. These results demonstrate that increased body temperature results in a circulating lymphocyte pool which is "primed" for the production of elevated levels of IFN-gamma activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of exercise-heat acclimation on fluid, electrolyte, and endocrine responses during tilt and +Gz acceleration in women and men.

Plasma fluid, electrolyte, protein, renin, and vasoactive hormone (epinephrine, norepinephrine, vasopressin) responses were measured in six women (21-23 yr) and four men (21-38 yr) before and immediately following an orthostatic tolerance test (70 degrees head-up tilt) and a +Gz (head-to-foot) acceleration tolerance test (0.5 G X min-1 linear ramp to grayout). These tests were conducted before and after 12 consecutive days of exercise-heat acclimation when the subjects exercised on a cycle ergometer at a relative oxygen uptake of 44% to 49% peak oxygen uptake in a hot environment (Ta = 40 degrees C, 42% rh). During acclimation plasma volume increased by 10.6% (p less than 0.05) in the women and by 11.9% (p less than 0.05) in the men; in both groups exercise heart rate decreased significantly. After acclimation, acceleration tolerance was unchanged in both groups (range 3.1 to 3.4 G); the women's tilt tolerance was unchanged (range 33.6 to 39.5 min), but the men's tilt tolerance increased from 30.4 min before to 58.3 min (delta = 91%, p less than 0.05) after acclimation. Since the pattern of fluid, electrolyte, and protein shifts and acceleration tolerances in the women and men were virtually the same, the hormone responses were highly variable, and the men's tilt tolerance increased significantly after acclimation, it is clear that responses to tilting cannot be used to predict responses to acceleration. Analysis of data from the present study and the literature suggests that current exercise training regimes should be unrestricted for astronauts who have not previously been highly endurance trained.(ABSTRACT TRUNCATED AT 250 WORDS)

Exercise in a cold environment after sleep deprivation.

Seven subjects exercised to thermal comfort in a cold environment (O degrees C, 2.5 m X s-1) after normal sleep (control) and following a 50-h period of sleep deprivation. Resting core temperature (rectal) taken before the subject entered the cold environment was significantly lower (-0.5 degrees C, P less than 0.05) following the 50-h period of wakefulness. However, rectal temperature was not different after 15 min of exercise during the two exposures, suggesting that the subjects stored heat more rapidly during the first 15 min of exercise after sleep deprivation. No significant differences in self-chosen exercise intensity, significant differences in self-chosen exercise intensity, heart rate, metabolic rate, or exercise time were evident between the control and sleep deprived exposures. Fifty hours of sleep deprivation failed to alter the core temperature response during exercise in severe cold stress, and subjects chose identical work rates to minimize fatigue and cold sensation. The results suggest that the 50-h sleep deprivation period was not a true physiological stress during exercise in a cold environment. (Supported by Contract #DAMD 17-81-C1023.)

Thermoregulation in Erythrocebus patas: a thermal balance study.

A thermal balance study over an ambient temperature (Ta) range of 15-40 degrees C was performed on six nonacclimated patas monkeys (Erythrocebus patas) weighing between 3.9 and 6.0 kg. O2 consumption, CO2 production, mean weighted skin temperature (Tsk), rectal temperature (Tre), respiratory evaporative water loss (Eresp), and total evaporative water loss (Etot) were measured continuously after equilibration at each Ta. Tsk increased as Ta increased, whereas Tre was maintained between 37.6 and 38.4 degrees C at Ta from 15 to 40 degrees C. Total evaporative heat losses increased with increasing Ta to a mean value of 76 W/m2 at 40 degrees C. Eresp was relatively constant and increased from 1.0 to 8.0 W/m2 at 15 and 40 degrees C, respectively. Whole-body conductance was similar to that previously reported for Macaca mulatta except at the highest Ta (40 degrees C), where the values for the patas monkey were significantly lower than those reported for the rhesus monkey (rhesus = 72 W/m2; patas = 33 W/m2). The data demonstrate that the patas monkey can maintain its core temperature within a narrow range over a wide range of Ta values. Additionally, Etot in the patas monkey is significantly higher than what has been reported in other nonhuman primates and approaches that reported in humans.

Sympathoadrenal responses to cold and ketamine anesthesia in the rhesus monkey.

The effect of cold exposure on the sympathoadrenal system in primates was studied with and without ketamine anesthesia in eight adult rhesus monkeys. Each monkey was placed in a primate chair at a thermoneutral temperature (25 degrees C) for 1 h (control) followed by cold exposure (12 degrees C) for 3 h or placed in a circulating water bath (28 degrees C) to induce a decrease in core temperature (Tre) to 35 and 33 degrees C. Plasma catecholamines were analyzed by high-pressure liquid chromatography with electrochemical detection (60-65% recovery, coefficient of variation = 15%). The 3-h cold exposure was associated with a 175% increase above control levels of norepinephrine (NE) and a 100% increase in epinephrine (E). Decreases were evident in Tre (0.5 degree C), mean skin temperature (Tsk, 5.5 degrees C), and mean body temperature (Tb, 2.0 degrees C). Continuous infusion of ketamine (0.65 mg . kg-1 . min-1) resulted in no change in the plasma levels of NE and E from the control levels. Tre, Tsk, and Tb all showed greater declines with the addition of ketamine infusion to the cold exposure. Water exposure (28 degrees C) under ketamine anesthesia resulted in a drop in Tre to 33 degrees C within 1 h. Plasma levels of NE and E were unchanged from control values at Tre of 35 and 33 degrees C. The data suggest that the administration of ketamine abolished both the thermoregulatory response and the catecholamine response to acute cold exposure.

Body fluid and hematologic adjustments during resting cold acclimation in rhesus monkey.

The purpose of this study was to examine body fluid adjustments during prolonged cold exposure in primates. Six male rhesus monkeys were acclimated for 35 days and 6 degrees C and 80% rh. Red cell mass, extracellular fluid volume, and total body water (TBW) were determined with 51Cr, 35SO4, and 3H2O, respectively, prior to and at various intervals during the cold stress. TBW was increased throughout the exposure, whereas changes in extravascular compartments had occurred within the 1st wk of cold exposure, after which they returned to control values. An increased concentration of blood constituents on day 1 was not accompanied by a decrease in cardiovascular volume. Blood volume and plasma volume in relation to TBW were significantly increased on day 3 and remained increased during the remainder of the exposure. These cardiovascular volume changes were accompanied by a significant hemodilution on day 3 and a gradual return to control values. An increased plasma osmolality and expansion of the erythrocytes (decrease in mean corpuscular hemoglobin concentration) were observed throughout the cold stress. These data suggest that the rhesus monkey may be an adequate primate model for studies of body fluid adjustments, especially during prolonged cold exposure, in primates in general, including the human.

Thermal balance in ketamine-anesthetized rhesus monkey Macaca mulatta.

A partitional calorimetry study compared thermoregulatory responses of unanesthetized adult rhesus monkeys (4 female, 1 male) to those anesthetized with ketamine HCl and exposed to ambient temperature (Ta) of 18, 29, 38 degrees C. Steady-state metabolic heat production (M), mean skin temperature (Tsk), rectal temperature (Tre), respiratory evaporative heat loss (Eres), and total evaporative heat loss (Etot) were measured at each Ta. Average Tre of anesthetized animals was reduced by approximately 1 degree C at Ta 18 degrees C, but thermal balance in anesthetized and control animals was maintained by reflexly decreased tissue conductance and shivering. For anesthetized animals, the average M increased 1.8 times over the lowest value of 40.13 W/m2 at Ta 29 degrees C, compared to a 1.5-fold increase for controls. Responses for both groups were not different at Ta 29 degrees C, both groups regulated body temperatures by vasodilation and increased sweating, but with ketamine sweating was reduced (35%). Effective tissue thermal conductance (K) was lowest at Ta 18 (10.8 W/m2 . degrees C) and increased to 39.4 W/m2 . degrees C at Ta 38 degrees C. No significant difference in K was found between ketamine and control groups at other Ta's.