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Biomedical subjects

A Muñoz

Publications and source records attributed to A Muñoz.

At least 307 records · Page 17Linked to original sources
PubMed1995

Changes in markers of disease progression in HIV-1 seroconverters: a comparison between cohorts of injecting drug users and homosexual men.

Comparisons of human immunodeficiency virus (HIV) disease progression between risk groups are difficult primarily because of the long incubation period of acquired immune deficiency syndrome (AIDS) and unknown times of infection. This is believed to be the first study that directly compared changes in T-lymphocyte subsets following HIV-1 seroconversion between cohorts of predominantly black injecting drug users and predominantly white homosexual men. Longitudinal trends of CD4 and CD8 percentages of total lymphocytes during 4 years were modeled as piecewise linear functions with a two-parameter correlation structure to accommodate within-person repeated observations. Prior to seroconversion the 151 injecting drug users started with similar CD4% and CD8% levels compared with the 99 homosexual men. Following seroconversion, larger changes were observed overall in the homosexual men compared with the injecting drug users for both markers (p < or = 0.001). The major discrepancies, however, were limited to the first 2 years. Subsequently, the CD4% levels of the two cohorts converged and then declined at similar rates. These comparative analyses of HIV seroconverters in homosexual men and injecting drug users suggest that risk group has only a minor effect on the initial course of HIV infection.

Adult↗
PubMed1995

Male gonadal function after chemotherapy in survivors of childhood malignancy.

Investigations of adult patients have shown that chemotherapy causes gonadal damage, but much less information is available about the impact of chemotherapy on gonadal function in children with malignant disease. At one time, being prepubertal during therapy was thought to confer some protection against chemotherapy induced gonadal damage. However, recent studies have indicated otherwise. We designed this study to assess gonadal function in 15 postpubertal males who had received polychemotherapy for a malignant disease during childhood and we compared them with 13 control adults males. The mean age of the patients at the time of the study was 18.2 +/- 3.6 years (range 13.8-29.0), and when given chemotherapy treatment was 10.2 +/- 3.0 years (range 6-16). At that time 12 were prepubertal and at the time of the study all were Tanner V. The mean interval from the completion of treatment until the study was 6.42 years (range 2.0-16.5). All patients had received polychemotherapy. We evaluated testicular size, sperm counts, LH and FSH after GnRH test, and testosterone levels. Puberty had progressed normally in all patients. We found no significant differences in testosterone and basal LH levels between patients and controls. However, we detected an appreciable difference in peak LH levels (P < 0.05) and in basal and peak FSH levels (P < 0.001). Seven patients had exaggerated LH response to GnRH, indicating dysfunction of the Leydig cells. The results of semen analyses were: 8 patients had azoospermia, 3 oligospermia, and 1 patient had a normal semen analysis. All patients with semen abnormalities presented a basal and peak FSH higher than the mean +2 SD of the control group. In summary, we found no evidence of gonadal protection in prepubertal patients. We found a high incidence of germinal cell damage, whereas Leydig cell abnormalities were found less often. An endocrine study of patients that have received chemotherapy is warranted.

Adolescent↗
PubMed1995

A new model of intraabdominal abscess: usefulness for hydrosaline metabolism studies in parenteral nutrition associated with sepsis.

The present study was set up to develop a new model of intraabdominal abscess (IAA) useful for hydrosaline metabolism studies based on the ligation of the appendix (AL) and wrapping of the appendix tip with omentum. Two experiments were designed: (1) to characterize the model and (2) to investigate extracellular volume (ECV) changes during parenteral nutrition (PN). Four groups of rabbits were studied at 3 (3DA) and 7 days (7DA) after AL or sham operation. PN was given for 6 days to two groups of septic rabbits: high volume HV) and low volume (LV) groups received 100 and 70 ml/kg.day of water with 7 and 0 meq/day of ClNa, respectively. Serum albumin (SA), ECV, and weight, water and sodium balances were determined. In 3DA, weight loss, reduced spontaneous intake, negative water balance, and reduction in SA were noted. Low SA, higher weight loss, and reduced intake were still observed in 7DA. SA correlated with ECV (r2 = 0.61, P = 0.003) in 7DA. Positive nitrogen balance was achieved during PN. The HV group had higher water and sodium balances than LV. In the HV group only, SA negatively correlated with sodium balance and with ECV at the end of PN (r2 = 0.87, P = 0.0007 and r2 = 0.9, P = 0.0001). The impact on hydrosaline metabolism of IAA in this model resembles that of moderate sepsis in humans. SA decrease appears to have two major components: escape around the inflammatory area and dilution. ECV expansion after PN is influenced by the initial SA concentration.

Abdominal Abscess↗
PubMed1995

How can relations be improved between the family and the support team during the care of terminally ill patients?

The family and patient are a unit of treatment. The support team should try to develop good communication with the family to be able to offer help respectfully and tactfully throughout the different phases of the terminal illness. We review: (a) the influence of the terminal illness on the family, and (b) the important factors in the intervention of the support team and their relationship with the family.

Female↗
PubMed1995

Anti-islet cell and anti-insulin antibody production by CD5+ and CD5- B lymphocytes in IDDM.

Although CD5 + B lymphocytes are mostly committed to the production of polyreactive natural autoantibodies, CD5 + B lymphocytes committed to the production of somatically mutated and monoreactive high-affinity IgM autoantibodies have been also shown. Increased proportions of CD5 + B lymphocytes in some autoimmune diseases, including insulin-dependent diabetes mellitus (IDDM), have been noticed. The present study was undertaken to analyse the differences between CD5 + and CD5- B lymphocyte subsets for production of IDDM-related autoantibodies, i.e. anti-human insulin antibodies (IA) and anti-human islet cell antibodies (ICA). For this purpose, Epstein-Barr Virus (EBV)-transformation of FACS cell-sorted CD5 + and CD5- B lymphocytes and unfractionated enriched B lymphocytes from nine IDDM patients treated exclusively with recombinant human insulin, and from four healthy control subjects was performed; a mean of 102-216 microcultures with a mean of 1,000-2,333 cells/microculture for each B-lymphocyte fraction and individual was established. Data show that both CD5 + and CD5- B-lymphocyte subsets from either normal subjects or from IDDM patients receiving recombinant human insulin, contain B lymphocytes committed to the production of IA-IgM as a common element of their repertoire. In contrast, cells committed to the production of IA-IgG were only detected among the CD5- B lymphocyte subset from some IDDM patients. Only one microculture, out of a total of 6,211 screened (from control subjects and patients), in the CD5- B-cell subset from a recently-diagnosed IDDM patient, was found to produce ICA-IgM lambda. This might suggest that the frequency of circulating B lymphocytes committed to the production of ICA is very low even in IDDM patients bearing serum ICA. EBV-transformed B cells producing the ICA-IgM lambda were stabilized and cloned by somatic hybridization technique. This ICA-IgM lambda human monoclonal antibody, designated HY1-MB91, is not polyreactive, but shows a restricted reactivity with human pancreatic islets, failing to react with other human tissues including cerebellar cortex, and lacking rheumatoid factor and anti-DNA antibody activities. It also lacks reactivity with pancreatic islets from other mammalian species (rat, mouse and monkey) as well as with other rat tissues, including cerebellar cortex. The antigen recognized by HY1-MB91 antibody in human islet cells is a cytoplasmic component mostly found in beta cells.

Adolescent↗
PubMed1995

Validity of a scale measuring beliefs regarding the "positive" effects of punishing children: a study of Mexican mothers.

This paper discusses the influence that "beliefs concerning the corrective effects of punishment" have on child punishment and abuse in a Mexican population. One hundred and five mothers responded to a questionnaire measuring these beliefs, and their responses were contrasted with the report those mothers gave regarding the physical punishment they inflict upon their children. A scale consisting of six items registering beliefs was developed and administered. The reliability (internal consistency) of the scale was assessed, and its validity was tested by using a factor analytic structural equations model which produced high factorial loadings from a "beliefs" factor to the scale's items. This was interpreted as a confirmation of construct validity. An indication of predictive validity was found in a high, significant structural correlation between the beliefs factor and a "corrective punishment" factor, measured by a series of related items. Mothers reported as abusing their children produced higher scores on the "beliefs" scale as compared to "control" mothers. The direct, significant effect of parent's beliefs on the punishment of children explains much about the child maltreatment problem in the studied society.

Adult↗
PubMed1995

Ontogeny of vasotocinergic and mesotocinergic systems in the brain of the South African clawed frog Xenopus laevis.

For a better understanding of the development of neurotransmitter systems and of their putative functional significance during ontogenesis, the development of the vasotocin (AVT) and mesotocin (MST) systems in the brain of Xenopus laevis was studied by means of immunohistochemical techniques. Weakly immunoreactive fibers were already present at late embryonic stage 38 in the caudoventral part of the telencephalon and in the ventral part of the diencephalon. The earliest immunodetectable AVT and MST immunoreactive cell bodies were found in the developing preoptic area at late embryonic stage 43. At the end of the embryonic period (stage 45), AVT immunoreactive fibers have reached the future medial amygdala, the midbrain tegmentum, the median eminence and the neural lobe of the pituitary. When compared with AVT immunoreactive fibers, the development of MST fibers shows some temporal delay. During the premetamorphosis (stages 45-52), AVT immunoreactive cell bodies appear in the medial part of the suprachiasmatic nucleus, the dorsal infundibular region, and the midbrain tegmentum, whereas fibers can now be traced to the nucleus accumbens, the septum and the medial amygdala in the forebrain, to the midbrain tegmentum, the reticular formation, the raphe nuclei, and the solitary tract nucleus in the brainstem, and to the spinal cord. Further maturation of the AVT system during prometamorphosis (stages 53-58) includes the appearance of immunoreactive cell bodies in the lateral part of the suprachiasmatic nucleus, the ventral preoptic area, and the dorsal infundibular region. By the end of the metamorphosis (stage 65), the maturation of the AVT/MST systems reaches an almost adult-like pattern. It should be noted that in amphibians, in contrast to mammals, the early appearance of the AVT/MST systems, including their extensive extrahypothalamic component, suggests that the two neuropeptidergic systems may play a significant role during development.

Animals↗
PubMed1995

Failure of T-cell homeostasis preceding AIDS in HIV-1 infection. The Multicenter AIDS Cohort Study.

We and others have postulated that a constant number of T lymphocytes is normally maintained without regard to CD4+ or CD8+ phenotype ('blind' T-cell homeostasis). Here we confirm essentially constant T-cell levels (despite marked decline in CD4+ T cells and increase in CD8+ T cells) in homosexual men with incident human immunodeficiency virus, type 1 (HIV-1), infection who remained free of acquired immunodeficiency syndrome (AIDS) for up to eight years after seroconversion. In contrast, seroconverters who developed AIDS exhibited rapidly declining T cells (both CD4+ and CD8+) for approximately two years before AIDS, independent of the time between seroconversion and AIDS, suggesting that homeostasis failure is an important landmark in HIV disease progression. Given the high rate of T-cell turnover in HIV-1 infection, blind T-cell homeostasis may contribute to HIV pathogenesis through a CD8+ T lymphocytosis that interferes with regeneration of lost CD4+ T cells.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Routine prenatal ultrasound screening for fetal abnormalities: 22 years' experience.

We describe the results of routine obstetric ultrasound examination over a period of 22 years (1970-91) at the Institut Universitari Dexeus, Barcelona, Spain. A total of 1006 malformed fetuses or neonates were identified at abortion or delivery. The prevalence of fetal abnormalities was 3.03%. Fetal anomalies were diagnosed antenatally in 788 (78.33%) cases. Early prenatal diagnosis (before 22 weeks of gestation) was made in 598 (59.44%) cases. The detection of malformed fetuses increased from 19.75% in the first phase of the study (1970-74) to 96.33% in the last phase (1990-91). The specificity of the method was over 99% throughout the study period. The most frequently diagnosed anomalies were urinary tract anomalies (22.86% of cases), followed by head and neck anomalies (18.68%), musculoskeletal anomalies (8.64%), heart anomalies (7.35%) and gastrointestinal anomalies (7.35%). The earliest diagnosed malformations were those of the thoracoabdominal wall (81.08%), followed by defects of the urinary tract (70.86%) and of the diaphragm (70.83%).

Congenital Abnormalities↗
PubMed1995

Levels of aflatoxin-albumin biomarkers in rat plasma are modulated by both long-term and transient interventions with oltipraz.

The validation process for biomarkers to be used for monitoring the efficacy of preventive interventions in humans includes assessments of whether levels of the biomarker can be modulated in experimental models. From this perspective, the influence of two intervention protocols with the chemopreventive agent oltipraz on rates of formation and disappearance of aflatoxin-albumin adducts has been evaluated in rats chronically exposed to aflatoxin B1. Male F344 rats were treated daily with 20 micrograms aflatoxin B1, p.o. for 35 days. The first strategy employed a standard, long-term intervention in which basal AIN-76A diet was supplemented with 0.05% oltipraz beginning one week before AFB1 treatment and continuing throughout the period of carcinogen exposure. In this setting, treatment with oltipraz reduced the rate of formation of aflatoxin-albumin adducts such that steady-state levels were lowered by > 50% from control values of 400 pmol aflatoxin adducts/mg albumin. The time-course for reaching respective steady-state levels was unchanged, with or without oltipraz intervention. The second intervention strategy utilized a delayed, transient protocol in which oltipraz was fed for 2 weeks beginning 1 week after AFB1 dosing began and ending 2 weeks before AFB1 dosing was completed. This second strategy, which models clinical interventions in chronically exposed individuals, produced a steady decline in aflatoxin-albumin adduct levels that approached a 50% reduction by the end of the AFB1 exposure period. Development of smooth curve functions allowed for the estimation of the ratio of effects between the non-intervention and intervention groups as well as the simultaneous 90% confidence intervals for the aflatoxin-albumin adduct levels. These analyses indicated that long-term intervention with oltipraz produced a statistically significant reduction in levels of the aflatoxin-albumin biomarker at all times throughout aflatoxin exposure. By contrast, a statistically significant decrease in biomarker levels was not seen in the delayed, transient intervention protocol until the ninth day of the intervention. However, once achieved, significant differences from the control group were maintained for the remainder of the aflatoxin exposure period. These changes in aflatoxin biomarker levels are consistent with the cancer chemopreventive outcomes of these intervention protocols in rats. Collectively, these results support the utility of measuring this biomarker as a means for assessing the efficacy or chemopreventive interventions in individuals at high risk for aflatoxin exposure and development of hepatocellular carcinoma.

Aflatoxin B1↗
PubMed1995

Factors associated with changes in the use of antiretroviral therapy by a cohort of homosexual men infected with human immunodeficiency virus type 1.

Changes in the use of antiretroviral drugs and factors associated with changes from monotherapy with zidovudine (ZDV) to other regimens were quantified in the Multicenter AIDS Cohort Study. Participants who had been receiving monotherapy with ZDV were categorized as (1) discontinuing ZDV monotherapy; (2) switching to disanosine (ddI), zalcitabine (ddC), or stavudine (d4T) monotherapy; (3) switching to combination therapy (ZDV with ddI, ddC, or d4T); or (4) continuing ZDV monotherapy. From 1990 to 1994, the percentage of participants using ZDV monotherapy decreased from 27% to 17% (among participants without AIDS) and from 60% to 17% (among those with AIDS). At the same time, the proportion of participants using combination therapy increased from zero to 8% (no AIDS) and from 8% to 26% (AIDS). Polychotomous logistic regression methods were used to identify the factors predicting changes from ZDV monotherapy. Among participants without AIDS, indicators of drug failure (such as a lower CD4 lymphocyte count or symptoms of human immunodeficiency virus type 1 infection) were predictive of the initiation of combination therapy, while among patients with AIDS they were predictive of a switch to an alternative monotherapy. A decrease in hemoglobin levels, a marker of ZDV toxicity, was predictive for all patients of a switch to other monotherapy. These data show that clinicians and patients are opting for more aggressive antiretroviral regiments and that changes in CD4 lymphocyte count and in the status of symptoms remain the primary guides for changes in therapy.

Antiviral Agents↗
PubMed1995

Relationship of blood rheology to lipoprotein profile during normal pregnancies and those with intrauterine growth retardation.

AIMS: The effects on fetal growth of hyperlipidaemia in pregnancy are not well understood at present. In this study the different lipid fractions in normal pregnancies and pregnancies complicated by intrauterine growth retardation (IUGR) were determined and related to changes in plasma and serum viscosity. METHODS: Two groups of pregnant women were studied. Group 1 consisted of 35 healthy pregnant women aged between 21 and 38 years with no previous pathology and a normal pregnancy to term. Group 1 patients were studied at four periods defined at the start of the study: (1) < or = 17 weeks; (2) 18-24 weeks; (3) 25-32 weeks, (4) > or = 33 weeks. Group 2 consisted of 24 pregnant women aged between 16 and 34 years with ultrasound diagnosed IUGR confirmed after birth. Plasma lipids and plasma and serum viscosity were measured. RESULTS: Plasma triglycerides, low density lipoprotein cholesterol, and total cholesterol increased progressively throughout pregnancy, with significantly higher values after week 25. Apolipoprotein A (ApoA) and triglyceride concentrations were significantly lower in the IUGR group than in the normal group. The HDL/ApoA ratio was greater in the IUGR group than in the control group, as was the ApoB/ApoA ratio. There were no differences in the other lipids. Plasma and serum viscosity was higher in the IUGR group than in the normal group. CONCLUSIONS: Haemorheological modifications in the IUGR group are partly secondary to changes in high density lipoprotein metabolism and the competitive inhibition of fibrinolysis by ApoB, which is increased in pregnancies with IUGR. Changes in ApoA, and more specifically in the ApoB/ApoA ratio, could be good markers for the early detection of IUGR.

Adolescent↗
PubMed1995

Comparative hematological study of two breeds of foals (Andalusian and Arab) subjected to exercise of progressive intensity.

Exercise-induced hematological alterations were studied in 20 four-year old foals, 11 Andalusian and 9 Arabian. They were subjected to a test exercise program consisting of 4 levels of gradually increasing intensity (15, 20, 25 and 30 km/hr) with a duration of 5 min each. Blood samples were taken during resting, after each exercise level and at 10 and 30 min of recovery from exercise. The following hematic parameters were analyzed: red blood count, hematocrit value, hemoglobin, volumetric indexes (MCV, MCH and MHCH) and total plasma proteins. The alterations as a result of the physical effort were studied as well as any possible differences between the two breeds. The Arabian foals showed higher total plasma protein concentrations when resting, after each exercise level and at 10 mins of recovery time. The other variables studied remained with similar values in the two breeds without any significant changes.

Animals↗
PubMed1995

Hematological changes observed in Andalusian horses with laminitis.

Clinical blood chemistry was studied on 13 Andalusian horses with laminitis. Ten healthy horses were used as controls. Blood samples were taken within the first 24 hr after the onset of the disease in Obel grade 3 before any type of treatment was given. No significant differences were observed in the number of red blood cells and white blood cells between Andalusian horses affected by laminitis and healthy animals. Significant decrease in the number of neutrophils and increased number of lymphocytes were noted. A significant increase in the enzymatic activity of CPK, LDH and AST in these animals strongly suggested the presence of muscular and hepatic disorders. The K ion increased, meeting with a slight acidosis. There was also an increase of glucose and total proteins. This fact may be a result of an excessive intake of carbohydrates (which could cause hyperglycaemia) and a diminution of the plasma volume, as a consequence of fluid movement as well as the sweating process (which could cause protein haemoconcentration).

Alanine Transaminase↗
PubMed1995

Geographic variation in HIV infection among injecting drug users with Barcelona.

In response to a high incidence of AIDS among injecting drug users in Barcelona, Spain, the city established a program in four geographically distinct centers for assistance and surveillance. The centers provided testing, counseling, and monitoring of infectious diseases. In 1991-92, HIV rates were 33% in the northwest center, 39% in the western center, 39% in the east, and 71% in the south. Differences between the rates in the southern center when compared with those in the other centers were very significant (P < or = .001). These data show geographic variation of HIV infection within one city and substantiate the need to provide expanded medical care in the drug misuse treatment setting.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Bone marrow transplantation in 46 pediatric patients with non-Hodgkin's lymphoma. Spanish Working Party for Bone Marrow Transplantation in Children.

We report a retrospective analysis on 46 pediatric patients (median age 9 years, range 1-17 years) with non-Hodgkin's lymphoma (NHL), transplanted in six Spanish centers. Fourteen patients underwent allogeneic bone marrow transplantation (BMT) and 32 autologous BMT. Most patients were boys (36 of 46). Twenty one cases were of lymphoblastic lymphoma, 19 Burkitt's lymphoma and six diffuse large cell lymphoma. Maximal Murphy's stage any time before BMT was stage III in 17 cases and stage IV in 29 cases. At BMT, 13 cases were in first CR, 21 in second CR, seven in third CR, four with sensitive active disease and one with refractory disease. All patients transplanted in CRl were considered candidates for BMT because of delayed CR (two cases), failure of the first-line therapy (seven cases) or central nervous system (CNS) or BM infiltration at diagnosis (four cases). Conditioning therapy included TBI in 33 patients and 13 cases were conditioned with chemotherapy alone. Toxic mortality was 13% (three of 14 in the allogeneic BMT group and three of 32 in the autologous group). No toxic deaths were registered in 13 patients undergoing BMT in CR1 (three allogeneic BMT and ten autologous BMT). Twelve patients relapsed 1-7 months after BMT. Overall event-free survival (EFS) was 58% (42-73%; confidence interval (CI) 95%), with a median follow-up of 33 months. EFS was similar for allogeneic BMT and autologous patients. Disease status at BMT was the only predictive factor for EFS (P < 0.01). There were no significant differences between patients in CR1 (82.5%) and CR2 (68%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

[Hemoglobin in blood donor selection].

PURPOSE: To evaluate and establish a relationship between serum ferritin value and haemoglobin level, serum iron or transferrin in volunteer blood donors. MATERIAL AND METHODS: We have studied a group of 479 blood donors from Navarra's Health Area V, whose blood cell examination, iron, ferritin and transferrin values were determined. We classified these donors in 4 groups according to their ferritin concentration (ng/mL): f1 (0-12), f2 (13-20), f3 (21-400) and f4 (more than 400). The results were analyzed by the statistical program SPSS/PC+. The sensitivity, specificity, accuracy and predictive value of the positive test, for the determination of haemoglobin level as an indicator of iron deposits were calculated. RESULTS: The comparative statistical study of all these groups indicated that there were significant differences in the ferritin and the haemoglobin values (p < 0.001 and p < 0.05, respectively), except between f1 and f2, which only presented and intergroup difference in the ferritin values. In blood donors, the estimation of iron deposits from the hemoglobin level showed a diagnostic sensitivity greater than 90%. CONCLUSIONS: Haemoglobin values would allow the selection of those donors that could have an iron deficiency, or a borderline concentration; nevertheless, it would not allow the distinction between these two groups. This last observation is not important because donors that show a ferritin value lower than 20 ng/mL should not give blood. When the ferritin is greater than 20 ng/mL in men, the iron deposits will be adequate in 97% of them. This percentage is about 90 in women whose haemoglobin level is greater than 12.5 g/dL. Therefore, we consider that haemoglobin values present a good cost/benefit ratio for donor selection.

Adult↗