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Biomedical subjects

A M Torres

Publications and source records attributed to A M Torres.

At least 73 records · Page 4Linked to original sources
PubMed1988

Childhood tracheobronchial mucoepidermoid carcinoma: a case report and review of the literature.

Mucoepidermoid carcinoma of the lung presenting in childhood is an uncommon neoplasm. Symptoms of progressive bronchial obstruction proceed the recognition of this lesion. The well-confined local growth and minimal metastatic potential of childhood mucoepidermoid carcinoma make local resection with maximum conservation of pulmonary parenchyma the recommended operative treatment. Adequate surgical resection precludes the need for further radiation therapy or chemotherapy. This report details the presentation and treatment of a child with this rare tumor and reviews the present literature experience with childhood mucoepidermoid carcinoma.

Bronchial Neoplasms↗
PubMed1987

Renal and hepatic glutathione pool modifications in response to depletion treatments.

In this study we examined the response of the renal and hepatic glutathione (GSH) pool in rats to drastic GSH depletion treatments. For this purpose, we used a protein-free diet, starvation, and the injection of varying doses of diethyl maleate as depleting agents. We analysed GSH levels in both kidney and liver tissue homogenates after rats were fed a protein-free diet for 2 or 7 days or starved for 1, 2, or 3 days, as well as after diethyl maleate administration in a single maximal dose or in varying doses. The results indicated that the liver GSH pool was always more labile than the kidney GSH pool. Moreover, kidney GSH levels were almost unchanged after 7 days on a protein-free diet or after 2 days of starvation, while liver showed significant changes in GSH levels. When we analysed the repletion rate, kidney had higher kinetic parameters (k = 0.148 h-1) than liver (0.097 h-1). We conclude that efficient mechanisms of maintaining GSH levels exist in the kidney and these may serve to avoid GSH diminution and hence preserve renal function during states of GSH depletion.

Animals↗
PubMed1987

Urinary concentrating defect in glutathione-depleted rats.

The effect of an acute depletion of glutathione by diethyl maleate injection on renal concentrating function was examined in rats. The parameters tested were the concentration and dilution of urine, applying conventional clearance techniques. Tissue osmolality and Na+-K+ ATPase activity were also measured. Diethyl maleate treated rats showed a diminished renal glutathione concentration and an impairment in the glomerular filtration rate and in electrolyte and water excretion. Treated rats also showed a diminished urine-to-plasma osmolality ratio as compared with controls. The studies on free water formation revealed a marked difference between groups; these data were supported with a diminished medullary Na+-K+ ATPase and a diminished corticomedullary osmolality gradient in the treated rats. The studies suggest that one area of target cells of glutathione depletion is that of the ascending limb of Henle's loop.

Animals↗
PubMed1986

Rat kidney function related to tissue glutathione levels.

Rat renal function was evaluated during acute depletion of glutathione (GSH) produced by different doses of diethyl-maleate (DEM). Significant alterations in renal function were observed when the GSH level diminished. The replenishment of GSH and the restoration of renal function were also investigated at various times after the injection. Similar time courses were observed of both the GSH level and renal functions, but the former was shortest. This suggests that the restoration to normal of GSH renal content was necessary in order to regain appropriate kidney function. Furthermore, the fact that impairment of sodium excretion occurred simultaneously with GSH depletion may be considered as evidence of the first event in GSH protective action. It may be hypothetized that the thick ascending limb is the principal renal target for this deficiency.

Animals↗
PubMed1985

The critical level for preservation of continence in the ileoanal anastomosis.

Mucosal proctectomy with ileoanal anastomosis was performed for 90 patients with ulcerative colitis or polyposis over the past 18 years. In three, the anastomosis was at the dentate line. All three had varying degrees of soilage necessitating permanent ileostomy in one. For 12 patients with the anastomosis 1.0 cm proximal to the top of the columns, all were totally continent, but six experienced recurrent disease. For 75 in the third group, the anastomosis was at the top of the columns. Five await ileostomy closure. Of the other 70, none experienced recurrent disease and three have mild nighttime soilage, two of which are less than 1 year following operation. We recommend that the transitional epithelium of the anorectal columns be preserved.

Anal Canal↗
PubMed1985

Hirschsprung's disease.

This review of Hirschsprung's disease reflects the authors' experience with it and outlines the current recommendations for management of its various manifestations.

Biopsy↗
PubMed1985

Omphalocele and gastroschisis.

This brief article outlines our philosophy and management of omphalocele and gastroschisis based on personal experience with more than 200 patients.

Abdominal Muscles↗
PubMed1979

Alcohol dehydrogenase activity in diploid and autotetraploid Phlox.

The effect of polyploidy on the activity of alcohol dehydrogenase was examined in a series of diploid and synthetic autotetraploid Phlox drummondii. In most cases autotetraploids had about twice as much activity as the corresponding diploids, in two cases autotetraploids had about 1.5 times more activity, and in one wild seed pair the activity of the tetraploid was somewhat lower.

Alcohol Oxidoreductases↗
PubMed1977

Dissociation-recombination of sunflower seed acid phosphatase.

Formal genetic studies of sunflower (Helianthus annuus) seed acid phosphatase (ACP, E.C. 3.1.3.2) had suggested that the functional enzyme consists of two polypeptide subunits. The dimeric quaternary structure was demonstrated by dissociation-recombination procedures. Dissociation of electrophoretically distinct homodimers was effected upon freezing of extracts in a pH 8-9 buffer containing 1 M NaCl and 0.1 M 2-mercaptoethanol. Reassociation, as indicated by the formation of the hybrid isozyme, occurred during 12 hr dialysis against a pH 7.0 buffer.

Acid Phosphatase↗
PubMed1976

Dissociation-recombination of intergenic sunflower alcohol dehydrogenase isozymes and relative isozyme activities.

Two unlinked genes, Adh1 and Adh2, control of the production of alcohol dehydrogenase (ADH) in seeds of the animal sunflower (Helianthus annuus). Each gene is polymorphic, having F and S alleles. Starch gel electrophoretic zymograms of the four possible double homozygotes have three bands, representing two homodimers and an intermediately migrating intergenic isozyme. Zymograms of double heterozygotes consist of nine bands produced by ten isozymes: six intragenics and four intergenics, two of which are coincident. Results of dissociation-recombination (D-R) experiments are reported which demonstrate the subunit composition of the intergenic isozymes, thus supporting the relationships suggested by genetic studies. Densitometric tracings of the zymogram of a cleared gel and measurements of activities of homodimer isozymes eluted from gels follwoing D-R of an intergenic isozyme showed that the Adh2 isozymes were more that twice as active as those of Adh1. Measurements of activities of crude extracts from the four possible double homozygous genotypes indicated that the seeds of the genotype Adh1F/Adh2F, Adh2S/Adh2S produced more activity than the other three. This genotype is the most common one found in wild and cultivated stocks. Isozymes eluted following electrophoresis of the same extracts had averages of 19%, 70%, and 11% of total activity contributed by the Adh1, Adh2, and intergeneic isozymes, respectively. A simple but efficient method of isozyme elution from starch gels is described which resulted in nearly full expected recovery (approximately 46%) of the ADH activity in the applied sample.

Alcohol Oxidoreductases↗
PubMedDate not supplied

Malrotation of the intestine.

Malrotation of the intestinal tract is a product of a well defined aberrant embryology. Because the consequences of malrotation associated with a midgut volvulus may be catastrophic, an understanding of the anatomy, diagnostic criteria, and appropriate therapy for this putative emergency illness is imperative. This report summarizes a recent 18-month experience with this diagnosis and contrasts this experience with that in the published literature. More than half (14/22) of the patients presented during the first month of life, and all had vomiting, which in most cases was bilious. The barium upper gastrointestinal series was the preferred diagnostic study, being both sensitive (18/19, 95%) and accurate (18/21, 86%). In this series two-thirds of the patients presented with volvulus (15/22, 68%) of whom five had ischemic intestine requiring resection. One of these children died of overwhelming sepsis. A Ladd procedure was the preferred treatment, which as defined by us includes evisceration and inspection of the mesenteric root, counterclockwise derotation of a midgut volvulus, lysis of Ladd's bands with straightening of the duodenum along the right abdominal gutter, inversion-ligation appendectomy, and placement of the cecum into the left lower quadrant. A high index of suspicion in the neonate with vomiting, rapid diagnosis, and appropriate operative therapy results in a predictable favorable outcome for children with intestinal malrotation.

Child, Preschool↗
PubMedDate not supplied

Central diabetes insipidus due to herpes simplex in a patient immunosuppressed by Cushing's syndrome.

OBJECTIVE: To describe a patient immunocompromised by Cushing's syndrome in whom central diabetes insipidus developed as a complication of herpes simplex involvement of the hypothalamus. METHODS: We present a case, including results of laboratory and histopathologic studies, in which herpes simplex was established as the causative agent for central diabetes insipidus. RESULTS: A woman with ectopic corticotropin-dependent Cushing's syndrome, diabetes mellitus, carcinoid tumor, and a history of thyroid cancer had the precipitous onset of seizure and fever, and hypotonic polyuria and progressive hypernatremia developed. Central diabetes insipidus was diagnosed and successfully treated with desmopressin. Nevertheless, the patient's condition deteriorated and she died. Autopsy revealed herpes simplex encephalitis involving the magnicellular neurons of the hypothalamus. CONCLUSION: Central diabetes insipidus caused by viral infections has been reported in immunosuppressed patients, such as those with acquired immunodeficiency syndrome (AIDS). To our knowledge, this is the first report of a herpes infection causing diabetes insipidus in a patient immunosuppressed by Cushing's syndrome. This case demonstrates that, in patients with Cushing's syndrome, diabetes insipidus may develop as a result of herpes simplex infection of the hypothalamus.

Cushing Syndrome↗
PubMedDate not supplied

[Acute renal failure caused by ceporin, kanamycin and gentamicin].

The use of aminoglycosides and cephalosporins is fairly often complicated by acute renal failure (ARF), particularly so if overdoses are used and baseline renal function is impaired. The course of ARF and outcome of treatment have been analyzed in 51 patients. ARF was caused by a nephrotoxic effect of aminoglycosides, cephalosporins or a combination thereof (ARF, type A) in 30 (58.8%) patients, and a combination with other factors (hypotension, arterial hypertension, sepsis) in 21 (41.2%) patients (ARF, type B). Nephrotoxic effect was more commonly produced by a ceporin-gentamicin combination (in 34 (66%) of 51 cases). Nineteen (55.8%) of the 34 patients died, in spite of extracorporeal detoxication treatment (peritoneal dialysis, hemodialysis), which way be attributed to a severe original condition (mostly, due to severe sepsis, original functional renal insufficiency, etc.) rather than the nephrotoxic effect of antibiotics. Hyperazotemia without marked oliguria is a specific feature of ARF, induced by nephrotoxic action of antibiotics. Preventive principles are proposed.

Acute Kidney Injury↗