Biomedical subjects
Publications and source records attributed to M C Montero.
We report the first case in the medical literature (to our knowledge) of a patient with human immunodeficiency virus infection who was being treated with ritonavir and developed signs of severe vascular involvement and irreversible coma after the administration of 3 mg of ergotamine tartrate.
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The BactiCard Neisseria (Remel, USA) is a chromogenic enzyme substrate system for identifying Neisseria gonorrhoeae, Neisseria meningitidis, Neisseria lactamica, and Moraxella catarrhalis. The identification system consists of a card with four test circles impregnated with chromogenic substrates for indoxyl butyrate esterase (IB), prolyl aminopeptidase (PRO), gamma-glutamyl aminopeptidase (GLUT), and ss-galactosidase (BGAL). These substrates permit the identification of Moraxella catarrhalis, Neisseria gonorrhoeae, Neisseria meningitidis, and Neisseria lactamica, respectively. After hydration of the circles with buffer, colonies from growth on selective media or a subculture are applied to the four circles. IB and BGAL reactions are read for a blue-green color after 2 and 15 min, respectively. PRO and GLUT reactions are read at 15 min for a red color after addition of a developer reagent. Identifications obtained with the BactiCard Neisseria were compared with those obtained using conventional procedures for 558 isolates in a blinded fashion. The BactiCard Neisseria identified 100% of 254 Neisseria gonorrhoeae, 100% of 125 Neisseria meningitidis, 53 (98.2%) of 54 Neisseria lactamica, and 123 (98.4%) of 125 Moraxella catarrhalis isolates. The BactiCard Neisseria is an accurate and rapid system for identification of these microorganisms in the clinical laboratory.
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Anorexia nervosa (AN) has been associated with various cardiac disorders and several electrocardiographic abnormalities, the most prominent being sudden death and prolonged QT duration and dispersion. We report 2 cases of AN with marked repolarization abnormalities, the first clearly related to electrolyte imbalance, the second without a good explanation from metabolic, electrolytic or pharmacological sources. A retrospective analysis of 47 other consecutive patients with AN showed that sinus bradycardia was the most common ECG finding, but that QT or QTc interval prolongation was not a typical feature, being present in only 1 patient. The sole variable slightly correlated with QTc duration was the serum potassium concentration. Consequently, marked repolarization changes (QT interval and/or T wave morphology) in AN should not be taken as a feature of the disease, but should call for the search of potential causes such as metabolic and electrolytic disturbances, drug effects, or a possible genetic component.
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BACKGROUND AND OBJECTIVES: The supply of phenotyped red blood cells (RBC) for patients with several RBC antibodies presents a difficult task to hospital blood banks and regional blood centers. The aim of this study was to establish a low-cost typing system to allow extensive phenotyping of regular blood donors for clinically significant RBC antigens. MATERIALS AND METHODS: We developed a new buffer that greatly intensifies the antigen-antibody reaction and thus reduces the quantity of serum needed for phenotyping. The procedure was carried out on microplates. RESULTS: A total of 20,435 regular blood donors have been typed to date. For 752 units required for transfusion, 3,584 phenotyping tests were performed, validating the results by tube or gel typing methods; agreement was achieved in all cases. CONCLUSION: This technique seems adequate for phenotyping a large number of RBC units at very low cost, thus facilitating the availability of phenotyped blood.
Alveolar lipoproteinosis is a rare disease, a review of the Spanish Medical Index for 1971 to June 1994 showing only 9 reported cases. The intra-alveolar deposit of lipoprotein-type matter produces severe hypoxemia and favors infection by opportunistic germs. Treatment with massive bronchial lavage (MBL) removes the matter from the alveolar space, improves gas exchange and decreases the risk of infection. We report a case of primary alveolar lipoproteinosis treated with MBL in which the patient developed infections by Aspergillus fumigatus before lavage and after starting steroid treatment. The procedure was performed without complications, with significant clinical and gasometric improvement. The natural evolution of this disease is poorly understood. Spontaneous remissions have been observed, and as MBL is not a risk-free procedures, its use in treatment is controversial. We believe that when severe hypoxemia is present, MBL should be used early, when the risk is slight; MBL improves gas exchange and probably reduces the risk of opportunistic infection.
This article describes the economic and social impact of neutropenia induced by myelotoxic chemotherapy in patients with cancer during the period 1 January-31 December 1991. Neutropenia is a life-threatening complication of chemotherapy in patients with cancer. The episodes of fever and infections originating from neutropenia require hospitalization of the patient until the granulocyte levels are restored. The calculation of the economic cost was based on the following parameters: length of stay in hospital, analytical tests performed on the patient, type and cost of drug therapy administered, blood transfusions performed, health assistance received, cost of isolation and absence from work. The overall economic cost of neutropenia in patients with cancer reached 329,775 pesetas ($2,893). Cost of the health-care staff was the largest budget item in relation to the total health resources estimated.
1. The effects of external potassium concentration on potassium uptake and potassium permeability have been investigated in isolated chicken enterocytes. 2. Ouabain-sensitive K+ uptake exhibited simple saturation kinetics with an apparent affinity constant, KT, of approximately, 1 mM K+. In the presence of ouabain, K+ uptake relates linearly with its external concentration, and the apparent diffusion constant, KD, was 1.3 nmol mg-1 protein mM-1 min-1. 3. Membrane potential, evaluated from the transmembrane TPP+ distribution ratio, was lower than the potassium equilibrium potential. 4. Estimated potassium permeability is decreased by low external potassium concentration and unaffected by high external potassium concentration.
1. Efflux of K+ was measured in pre-loaded (86Rb+) chicken enterocytes incubated in buffers with external K+ concentration ([K+]0) between 1 and 40 mM. 2. A decrease in [K+]0 from 6 to 1 mM reduced the rate constant of K+ efflux, whereas it was stimulated by increasing [K+]0 from 6 to 40 mM. 3. The inhibitory effect of low [K+]0 on K+ efflux was: (i) higher than that expected from a change in the electrical driving force, suggesting that membrane K+ permeability has been decreased, and (ii) attenuated by A23187 and Na(+)-free buffers. 4. The effect of A23187 on K(+)-induced K+ efflux was abolished by apamin and that of Na(+)-free buffers by apamin, quinine or verapamil, which suggests that the effect of low K+ on K+ efflux seems to be due to decreased intracellular Ca2+ concentration. 5. The stimulatory effect of 40 mM K0+ on K+ exit can be accounted for by an increase in the electrical driving force. 6. The efflux of K+ at 40 mM K0 appears to occur through Ca2(+)-activated K+ channels (KCa) since it was prevented by 500 microM quinine and unaffected by bumetanide or 3,4-diaminopyridine. 7. In addition, the current results show that an increase in external K+ concentration reduced the ability of quinine to inhibit KCa channels, and even abolished that of Ba2+ and apamin.
The effects of Ba2+, quinine, verapamil, and Ca2(+)-free saline solutions on sugar active transport have been investigated in isolated chicken enterocytes. Ba2+, quinine, and verapamil, which have been shown to inhibit Ca2(+)-activated K+ channels, decreased basal and theophylline-dependent 3-O-methylglucose (3-O-MG) accumulation. Ca2(+)-free conditions reduced 3-O-MG uptake in theophylline-treated enterocytes, but it had no effect in control cells. On the other hand, the uptake of a non-actively transported sugar, 2-deoxyglucose (2-DOG), by control or theophylline-treated cells was not modified by the presence of verapamil or by Ca2(+)-removal. 3-O-MG increased ouabain-sensitive Na(+)-efflux, but had no effect on either K+ efflux or K+ uptake. However, in the presence of Ba2+, K+ uptake was stimulated by 3-O-MG, and this increase was prevented by ouabain. All these findings are discussed in terms of the role that K+ permeability may play in cellular homeostasis during sugar active transport.
Cells isolated by hyaluronidase incubation from chicken small intestine were used to study the effects of anisosmotic buffers on K+ transport. Hypo-osmolarity (200 mosmol.l-1) reduced both the ouabain-sensitive and the ouabain-resistant, but bumetanide-sensitive, net K+ influx and increased the K+ efflux. The hypo-osmolarity induced K+ efflux was prevented by quinine and unaffected by bumetanide. These results suggest that Ca2+-activated K+ channels may be involved in regulatory volume decrease in chicken enterocytes. Hyperosmotic conditions (400 mosmol.l-1) increased the portion of net K+ influx mediated by the Na+/K+-ATPase and that mediated by the bumetanide-sensitive K+ transport system, and decreased the K+ efflux.
The transport of potassium has been studied in epithelial cells isolated from chicken small intestine using 86Rb as a tracer for K+. (i) The uptake studies revealed that about 60% of the total K+ net flux is inhibited by ouabain and therefore mediated by the Na+-K+-ATPase. About 20% of the ouabain-insensitive K+ net influx was inhibited by furosemide, bumetanide and by either Na+ or Cl- removal from the incubation solution, suggesting that a Na+/Cl-/K+ cotransport system might be present in chicken enterocytes. (ii) The efflux of K+ was measured from cells preloaded with 86Rb. K+ efflux was inhibited by Ba2+, quinine and verapamil; it was stimulated by A23187, and it was unaffected by 3,4-diaminopyridine. Apamin, that has no effect on basal rates of K+ efflux, abolished the effect of A23187. These findings suggest that K+ efflux appears to occur through Ca2+-activated K+ channels.
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OBJECTIVE: To assess the evolution of cytomegalovirus (CMV) retinitis and evaluate the possible complications associated with the use of intravitreal injections to treat this disease. DESIGN: A nonrandomized, retrospective study with case series was performed. The study took place over 34 months. SETTING: The study included patients with AIDS who developed CMV retinitis, and who were treated in the hospital, as outpatients, or both. PATIENTS: Twelve patients with AIDS and CMV retinitis diagnosed between June 1990 through April 1993 were included in the study. MAIN PATIENT PARAMETERS AND OUTCOME MEASURES: For each patient, the following data were recorded: age, risk factors, other systemic findings, dates of AIDS and CMV retinitis diagnoses, stage of AIDS, extent of the retinitis, CD4 lymphocyte count at the time of diagnosis of retinitis, visual acuity, clinical evolution of the ocular infection, therapy, complications caused by the treatment, development on nonocular CMV, and the use of zidovudine or didanosine during the study period. RESULTS: Vision improved or remained stable in nine patients and worsened in three. Two patients developed optic neuritis. The retinitis progressed to the other eye in only one of the eight patients who had unilateral involvement. The rate of relapse with maintenance therapy was 8.3% (n = 1) within the first 8 weeks. Treatment was well tolerated. There was no evidence of toxicity after a total of 226 intravitreal ganciclovir injections. All patients were able to tolerate zidovudine or didanosine concomitantly with intravitreal ganciclovir. CONCLUSIONS: Intravitreal ganciclovir appears to be an effective alternate to systemic ganciclovir in patients with severe neutropenia and in patients who choose to continue receiving systemic zidovudine or didanosine. Early treatment and long-term maintenance therapy is essential for preserving sight.
The surfaces of aerial plant provide a habitat for epiphitic microorganisms many of which are capable of influencing the growth of pathogens. In this study, fluctuation of bacterial population occurring in different growth stages of soybean leaves (Glycine max L Merrill) was examined using the dilution plate method. Three culture media were applied; invariably, the numbers of bacteria increased with increasing plant age. The total number of bacteria living on the detached leaves were ten times higher than leaves surfaces of soybean Asgrow 3127 (Group III). One hundred and seventy-five heterotrophic bacteria were obtained from both the phyllosphere and litter of the plant. Of these, fifty-one microorganisms (29%) were classified as members of the genus Bacillus; the remainder were mainly members of the irregular, nonsporing, Gram positive rods (coryneform bacteria). Approximately 52% of the total coryneform bacteria isolated was found to belong to the following two clusters: Arthrobacter and Corynebacterium. There were few Pseudomonas strains and 75% of the total isolated bacteria were able to grow in N-poor culture medium.