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Biomedical subjects

E Morales

Publications and source records attributed to E Morales.

At least 91 records · Page 5Linked to original sources
PubMed1994

Spectrophotometric determination of gallium in biological materials at nanogram levels with thiocarbohydrazone derivatives.

Two spectrophotometric methods for the determination of micrograms of gallium in biological materials are described. Proposed chromogenic reagents are 1-(phenyl-2-pyridyl)carbylidene-5-resorcylidenethiocarbohydrazo ne (PPRT) and 1-(phenyl-2-pyridyl)carbylidene-5-salicylidene thiocarbohydrazone (PPST), which form yellow 1:2 (gallium: reagent) complexes. Reactions develop at pH 4.5-6.0 in a 52% (v/v) DMF solution for PPST and at pH 4.0-7.5 in a 48% (v/v) ethanol solution for PPRT. Optimum conditions for reactions are discussed for molar absorptivity values of 59000 and 65000 l.mol-1.cm-1 for PPST and PPRT, respectively. Detection limits are 8 ng/ml for PPST and 5 ng/ml for PPRT, and the range of application is 20-800 ng/ml of gallium. Advantages of the methods include simplicity, high sensitivity and relative selectivity, allowing their application in the determination of gallium in spiked biological samples, using a previous extraction step in n-butyl acetate to avoid interference from Fe(III) and Cu(II).

Animals↗
PubMed1994

[Temporal lobectomy in refractory partial epilepsy. Report of 4 cases].

Thirty, out of 1200 patients of North Santiago Adult Epilepsy Program, were admitted to J J Aguirre Hospital due to refractory epilepsy. Looking for candidates for functional epilepsy surgery, these patients were evaluated by neurologists, psychiatrists and psychologists and with standard EEG, video monitored EEG, CAT scan, magnetic resonance imaging and SPECT. So far, four patients with temporal partial complex epilepsy have been studied, operated (anterior temporal lobectomy and amygdalo-hippocampectomy) and followed for more than one year. Of these, two are free of seizures, one has sporadic episodes and one has an important reduction. One of these patients had a postoperative amnestic syndrome of 3 to 4 weeks duration. According to these results and those reported in the literature, the rigorous selection of patients that could be benefitted by surgery is emphasized.

Adult↗
PubMed1993

Anion channels in the sea urchin sperm plasma membrane.

Ionic fluxes in sea urchin sperm plasma membrane regulate cell motility and the acrosome reaction (AR). Although cationic channels mediate some of the ionic movements, little is known about anion channels in these cells. The fusion of sperm plasma membranes into lipid bilayers allowed identification of a 150 pS anion channel. This anion channel was enriched from detergent-solubilized sperm plasma membranes using a wheat germ agglutinin Sepharose column. Vesicles formed from this preparation were fused into black lipid membranes (BLM), yielding single channel anion-selective activity with the properties of those found in the sperm membranes. The following anion selectivity sequence was found: NO3- > CNS- > Br- > Cl-. This anion channel has a high open probability at the holding potentials tested, it is partially blocked by 4,4'-diisothiocyano-2,2'-stilbendisulfonic acid (DIDS), and it often displays substates. The sperm AR was also inhibited by DIDS.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1993

Effect of transfer factor on myelosuppression and related morbidity induced by chemotherapy in acute leukaemias.

The aim of this study is to determine the safety and efficacy of Transfer Factor (TF) in accelerating the haematopoietic recovery in patients with acute leukaemias (AL), following intensive therapy to induce remission of the disease. Twenty-two patients with different types of AL (16 AML, three BC-CML and three ALL) were studied. The patients were divided in two groups. Group 1 (eight AML, two BC-CML and one ALL) received, after myelosuppression induced by chemotherapy, TF (1 unit daily, subcutaneous) until leucocyte count was > 2.5 x 10(9)/l and platelet count > 80 x 10(9)/l. Group 2 was considered the control group and did not receive TF. Treatment with TF accelerated the recovery of neutrophils, leucocytes, platelets (P < 0.001) and haemoglobin (P < 0.01). As a logical consequence, incidence and severity of infection and haemorrhage were lesser in the TF group than in the control group. There was no evidence that TF accelerated the re-growth of leukaemic cells. It seems that TF is safe in AL, accelerating haematopoietic recovery. However, it should be used with caution until results of additional trials become available.

Acute Disease↗
PubMed1993

Metabolic inhibition enhances Ca(2+)-activated K+ current in smooth muscle cells of rabbit portal vein.

The effect of metabolic inhibition on macroscopic and single-channel K+ currents in isolated rabbit portal vein myocytes was investigated by patch-clamp technique. Depression of adenosine triphosphate synthesis was produced by 2-deoxy-D-glucose (10 mM) and either cyanide (2 mM) or dinitrophenol (50 microM). Outward quasi-steady-state current evoked by a ramp protocol and outward time-dependent current during step depolarizations were increased during metabolic inhibition. The reversal potential for quasi-steady-state current shifted negatively toward equilibrium potential of K+ during treatment consistent with a role for K+ conductance and hyperpolarization of membrane potential. The macroscopic K+ current affected was 1) voltage dependent, 2) inhibited by intracellular Ca2+ chelation and low tetraethylammonium ion (1 mM) but unaffected by 4-aminopyridine (2 mM), and 3) associated with a rise in intracellular Ca2+ assessed by indo 1. Metabolic inhibition caused an increase in voltage-dependent large-conductance K+ channel (120-130 pS) activity in cell-attached patches of myocytes bathed in physiological solution (140 mM K+ in pipette). The channels were blocked in a flickery fashion by tetraethylammonium ion (0.5 mM) and inhibited with charybdotoxin (100 nM). We conclude that metabolic inhibition increases the activity of large-conductance Ca(2+)-activated K+ channels in vascular smooth muscle.

2,4-Dinitrophenol↗
PubMed1993

[Enteropathogenic microorganisms in children with acute diarrhea in 2 hospitals of Rosario, Argentina].

As part of a multicenter collaborative study the relative frequency of enteropathogenic agents in children less than 5 years of age with acute diarrhea was determined. Rates of isolation were similar as regards sex, age, and season. The frequency of polymorphonuclear cells (PMN) in the stools was significantly higher among patients requiring admission in comparison with ambulatory patients. Enteropathogenic E. coli (EPEC) was isolated more frequently in that group in comparison with outpatients (p < 0.001), mainly among children less than 5 months of age. The most prevalent agents were EPEC (26.1%), enterotoxigenic E. coli (ETEC) (9.7%), Shigella (8.5%), Rotavirus (5.1%), Giardia (3.6%), Campylobacter (3.2%), and Salmonella (2.4%). The EPEC predominant serogroups were 0 111, 0 55, 0 26, and 0 119. ETEC serotypes 0 153:H45 and 0 128:H21 were more often isolated. The predominant species in the genus Shigella were S. flexneri (80.5%), and S. sonnei (9.5%); in the genus Campylobacter, the species were C. jejuni (81.3%), and C. coli (18.7%). Shigella was clearly related to the presence of PMN in the faeces, in children less than 5 months old. Campylobacter was more frequent in ambulatory patients more than one year of age. Rotavirus was found predominantly in autumn and winter. Salmonella and ETEC were more frequent in summer. Giardia was associated with weight loss. In about 10% of the cases there were simultaneous mixed isolations of two or more agents. Salmonella isolates were sensitive to the majority of antimicrobial agents probed. Many Shigella and E. coli were resistant to sulfamethoxazole-trimethoprim and ampicillin (40-80%). Nearly all enterobacteria were sensitive to gentamicin and norfloxacin.

Acute Disease↗
PubMed1992

Risk factors and classification of acute suppurative cholangitis.

A prospective study was performed in 1282 patients with common bile duct stones to determine the clinical and laboratory parameters that could predict cholangitis, and the factors associated with greater severity of cholangitis. Patients were divided into two groups, with or without acute cholangitis, depending on the macroscopic appearance of bile aspirated from the common bile duct during surgery. Acute cholangitis was diagnosed when the aspirated fluid was turbid or clearly pus; the typical Charcot's triad was present in only 22 per cent of patients with acute cholangitis. Several clinical and laboratory parameters were significantly more common in these patients and, depending on their number, the probability of acute cholangitis increased significantly. The operative mortality rate was 1.2 per cent for patients without cholangitis and 11.9 per cent for patients with cholangitis. Depending on the number of factors present, patients with cholangitis were divided into three groups: mild acute cholangitis without mortality; moderate acute cholangitis with a mortality rate of 5.6 per cent; and severe acute cholangitis with a mortality rate of 27.5 per cent. The present classification allows the group of patients needing prompt endoscopic or surgical drainage to be identified.

Acute Disease↗
PubMed1992

A depolarization can trigger Ca2+ uptake and the acrosome reaction when preceded by a hyperpolarization in L. pictus sea urchin sperm.

The acrosome reaction (AR) is an exocytotic event that allows sperm to recognize and fuse with the egg. In the sea urchin sperm this reaction is triggered by the outer investment of the egg, the jelly, which induces ionic movements leading to increases in intracellular Ca2+ ([Ca2+]i) and intracellular pH (pHi), a K(+)-dependent transient hyperpolarization which may involve K+ channels, and a depolarization which depends on external Ca2+. The present paper explores the role of the hyperpolarization in the triggering of the acrosome reaction. The artificial hyperpolarization of Lytechinus pictus sperm with valinomycin in K(+)-free seawater raised the pHi, caused a small increase in 45Ca2+ uptake, and triggered some AR. When the cells were depolarized with KCl (30 mM) 40-60 sec after the induced hyperpolarization, the pHi decreased and there was a significant increase in 45Ca2+ uptake, [Ca2+]i, and the AR. This waiting time was necessary in order to allow the pHi change required for the AR to occur. Thus, the jelly-induced hyperpolarization may lead to the intracellular alkalinization required to trigger the AR, and, on its own or via pHi, may regulate Ca2+ transport systems involved in this process. Because of the key role played by K+ in the triggering of the AR, the presence and characteristics of ion channels in L. pictus isolated sperm plasma membranes are being explored. Planar lipid bilayers into which these membranes were incorporated by fusion displayed 85 pS single channel transitions which were cation selective.

Acrosome↗
PubMed1992

Simultaneous speciation of butyltin and phenyltin compounds in the waters of south-west Spain.

An analytical method for the simultaneous speciation of butylin and phenyltin compounds has been applied to a study of the water quality in six locations (rivers and sea) in South West Spain. It was not intended to provide a comprehensive survey of the area but to establish what the maximum levels might be for a subsequent and more detailed study. Phenyltin species were not found in any sample, however tributyltin was present (100-400 ng l-1) in the Cadiz Bay samples, which suggests that the biological water quality may sometimes be depressed. Wherever tributyltin was present, dibutyltin and monobutyltin occurred, possibly, as a result of a degradation process.

Chromatography, Gas↗
PubMed1992

Epidemic dermatitis due to contact with a moth in Cozumel, Mexico.

In early December 1989, an outbreak that was initially thought to be scabies was investigated among employees of tourist hotels in Cozumel, Mexico. Of 417 employees interviewed, only 19 (4.6%) met a case definition for scabies dermatitis, while 91 (21.8%) reported a nonspecific dermatitis of less than one-week's duration. Persons with nonspecific dermatitis related the onset of their dermatitis to skin contact with a moth that had been present in large numbers in November. At the time of the initial investigation in December, there were no active cases of dermatitis and the moth was no longer present. During early January 1990, numerous cases of dermatitis again began to be reported. Using a case definition for nonspecific dermatitis, a survey of Cozumel's resident population showed an attack rate of 12.1%. A case-control study revealed the only significant risk factor to be skin contact with the suspect moth (P less than 0.01), which had returned in large numbers. Six health workers volunteered to have the moth rubbed on their skin; within 5 min, five of six developed an intense pruritus followed by an erythematous rash. The moth was classified as Hylesia alinda Druce. This species has nettling hairs on its abdomen that excrete a histamine-like substance. Although this moth is normally present in small numbers in Cozumel, the passage of hurricane Gilbert killed most of its natural predators (wasps and bees), allowing its population to overgrow. No control measures were undertaken because the moth's natural predators returned that spring and dramatically reduced the moth population. No further outbreaks of dermatitis occurred.

Adolescent↗
PubMed1991

Effect of dietary fiber and starch on fecal composition in preschool children consuming maize, amaranth, or cassava flours.

Metabolic balance studies were carried out in young children fed diets based on maize, amaranth, or cassava flours and in corresponding casein controls. Dietary fiber intakes were 22.2, 20.5, and 9.0 g/day for the maize, amaranth, and cassava groups, respectively. Fecal energy losses at least doubled in all test diets when compared with the corresponding controls and could generally be accounted for by recovered fiber in the feces. Fecal starch was also a significant contributor to fecal energy in the cassava group. All cassava fiber was recovered in the feces, whereas only 48.4 and 16.3% were recovered from ingested maize and amaranth. 2,6-Diaminopimelic acid (DAPA), an indicator of bacterial mass, was highest in the cassava group. Expired breath hydrogen was highest for those consuming maize or cassava. Resistant starch may have been responsible for the high DAPA and breath hydrogen values in the cassava group.

Breath Tests↗
PubMed1991

Takayasu's arteritis in children.

We reviewed the clinical features of 26 children with Takayasu's arteritis. In contrast to what is often seen in adults, in this age group inflammation of different systems is a conspicuous feature. Eighty five percent of cases had arterial hypertension. The high incidence of arthritis and heart failure provoked confusion with rheumatic fever. There was a high frequency of positive purified protein derivative (73%) and lymphadenopathy (38%) with a histological picture of caseating granulomas, suggesting a link between Takayasu's arteritis and an atypical mycobacterial infection. No improvement of the arterial obstruction was observed with corticosteroid therapy. Takayasu's arteritis in children presents as an aggressive often lethal disease. The mortality rate was 35% over an observation period of 5 years.

Adolescent↗
PubMed1991

[Experience of the National Autonomous Board for Certification of Medical Specialties].

After 6 years of operation of a National (autonomous) Board for Certification of Medical Specialists, the number, distribution and training of medical specialists is analyzed. Problems regarding significant differences in the quality of training and imbalance among different specialties are identified. The medical profession has expressed its confidence and feels supported by the activities of the Board. However, health care deliverers and users in general are expected to increase their support and consideration for the information provided by the Board, in order to fulfill the purpose for which it was established.

Chile↗
PubMed1991

[Prevalence of gallbladder neoplasms in cholecystectomies].

The prevalence of gallbladder cancer in 10,468 cholecystectomy patients was studied: 3.4% of the female and only 1.32% of the male population had gallbladder cancer (p < 0.001). The female population had 2.7 times more cholelithiasis, and 7.9 times more cancer than the male population. Cancer incidence increases progressively with age, specially after the 5th decade.

Adult↗
PubMed1991

Dietary management of malnourished children with a new enteral feeding.

Balance (nitrogen, fat, carbohydrate) and growth studies were carried out in nine children (6 to 26 months old) recovering from protein-energy malnutrition (PEM) using a concentrated (1 kcal/mL) formula designed specifically for 1- to 6-year-olds. The formula provided 12% of energy as protein (18% whey, 82% casein), 44% of energy as carbohydrate (69% corn syrup solids, 31% sucrose), and 44% of energy as fat (50% high-oleic safflower oil, 30% soy oil, 20% medium-chain triglycerides). Means +/- standard deviations of apparent nitrogen retention and absorption were 90 +/- 3% and 39 +/- 13%, respectively. Mean fecal fat excretion was 1.3 +/- 1.0 g/day. Length-age increased 3.0 +/- 0.8 months and weight-age increased 8.3 +/- 3.8 months during the 2.4 +/- 0.3 months of the study. (Length-age and weight-age were defined as the age (in months) to which the child's length or weight corresponded at the 50th percentile of the National Center for Health Statistics reference data). Thirteen additional 40- to 30-month-old children with kwashiorkor were fed the formula for 8 to 35 days as part of the initial management of PEM. The result was prompt weight gain and increases in serum proteins. Its formulation and the findings of our study indicate that this new formula offers a notable advantage over products designed for infants or adults in the enteral alimentation of young children.

Body Height↗