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Biomedical subjects

C A Martinez

Publications and source records attributed to C A Martinez.

10 recordsLinked to original sources
PubMed2001

Gastric necrosis and perforation as a complication of splenectomy. Case report and related references.

Necrosis of the stomach after isolated splenectomy with the formation of gastrocutaneous fistula is a rare event that occurs in less than 1% of splenectomies. It is more frequent when the removal of the spleen is done because of hematological diseases. Its mortality index can reach 60% and its pathogenesis is controversial, as it may be attributed both to direct trauma of the gastric wall and to ischemic phenomena. Although the stomach may exhibit exuberant arterial blood irrigation, anatomical variations can cause a predisposition towards the appearance of potentially ischemic areas, especially after ligation of the short gastric vessels around the major curvature of the stomach. Once this is diagnosed in the immediate postoperative period, it becomes imperative to reoperate. The surgical procedure will depend on the conditions of the peritoneal cavity and patient's clinic status. The objective of this study was to report on the case of a patient submitted to splenectomy because of closed abdominal traumatism, who then presented peritonitis and percutaneous gastric fistula in the post-operative period. During the second operation, perforations were identified in anterior gastric wall where there had been signs of vascular stress. The lesion was sutured after revival of its borders, and the patient had good evolution. Prompt diagnosis and immediate treatment of this unusual complication are needed to reduce its high mortality rate.

Adolescent↗
PubMed2001

Libraries of hybrid proteins from distantly related sequences.

We introduce a method for sequence homology-independent protein recombination (SHIPREC) that can create libraries of single-crossover hybrids of unrelated or distantly related proteins. The method maintains the proper sequence alignment between the parents and introduces crossovers mainly at structurally related sites distributed over the aligned sequences. We used SHIPREC to create a library of interspecies hybrids of a membrane-associated human cytochrome P450 (1A2) and the heme domain of a soluble bacterial P450 (BM3). By fusing the hybrid gene library to the gene for chloramphenicol acetyl transferase (CAT), we were able to select for soluble and properly folded protein variants. Screening for 1A2 activity (deethylation of 7-ethoxyresorufin) identified two functional P450 hybrids that were more soluble in the bacterial cytoplasm than the wild-type 1A2 enzyme.

Amino Acid Sequence↗
PubMed2001

Enhanced accumulation of BiP in transgenic plants confers tolerance to water stress.

The binding protein (BiP) is an important component of endoplasmic reticulum stress response of cells. Despite extensive studies in cultured cells, a protective function of BiP against stress has not yet been demonstrated in whole multicellular organisms. Here, we have obtained transgenic tobacco (Nicotiana tabacum L. cv Havana) plants constitutively expressing elevated levels of BiP or its antisense cDNA to analyze the protective role of this endoplasmic reticulum lumenal stress protein at the whole plant level. Elevated levels of BiP in transgenic sense lines conferred tolerance to the glycosylation inhibitor tunicamycin during germination and tolerance to water deficit during plant growth. Under progressive drought, the leaf BiP levels correlated with the maintenance of the shoot turgidity and water content. The protective effect of BiP overexpression against water stress was disrupted by expression of an antisense BiP cDNA construct. Although overexpression of BiP prevented cellular dehydration, the stomatal conductance and transpiration rate in droughted sense leaves were higher than in control and antisense leaves. The rate of photosynthesis under water deficit might have caused a degree of greater osmotic adjustment in sense leaves because it remained unaffected during water deprivation, which was in marked contrast with the severe drought-induced decrease in the CO(2) assimilation in control and antisense leaves. In antisense plants, the water stress stimulation of the antioxidative defenses was higher than in control plants, whereas in droughted sense leaves an induction of superoxide dismutase activity was not observed. These results suggest that overexpression of BiP in plants may prevent endogenous oxidative stress.

Adaptation, Physiological↗
PubMed1995

Autosomal recessive nondystrophic myotonia. Report of a case with unusual clinical course.

We describe the case of a girl with a probable autosomal recessive form of nondystrophic hereditary myotonia whose clinical findings are more compatible with the dominant ones mainly myotonia congenita of Thomsen or myotonia fluctuans. Besides the clinical aspects of the atypical form presented by our patient, the efficacy of the more available drugs employed for the treatment of myotonia congenita is briefly discussed.

Adolescent↗
PubMed1991

Short-term antibiotic treatment in Whipple's disease.

We report the results of short-term antibiotic treatment in 19 patients with Whipple's disease (WD). The diagnosis was based on clinical features and on a characteristic small bowel biopsy. Patients received treatment for a mean of 7.9 weeks (range 4-20). Fourteen were treated with de-methyl-chlortetracycline (600 mg/day), and 1 also received chloramphenicol (1 g/day); 1 was treated with ampicillin (2 g/day), and 4 were treated with amoxicillin (1.5 g/day). In all patients, the clinical response was rapid and excellent, body weight increased significantly, diarrhea subsided, and fecal fat values returned to normal. Intestinal biopsies obtained after treatment was completed showed significant improvement based on a decrease in the number of macrophages staining positive with periodic acid-Schiff (PAS), normalization of villous structure, and decreased dilatation of lymphatic channels; free bacilli were absent, as shown both by light and electron microscopy. Seventeen patients have been followed for a mean of 99.4 months (range 6-300). Two died 30 and 72 months after diagnosis of Whipple's disease, 1 of laryngeal carcinoma and the other of colonic carcinoma. Fifteen patients are in excellent health. Three patients treated with tetracycline have had clinical and/or histologic relapses. In our experience, short-course antibiotic treatment with tetracycline or ampicillin and derivatives can be effective in WD, with few relapses and excellent outcome. No neurologic symptoms, either initially or during follow-up were observed.

Adult↗
PubMed1988

Control of diarrhoeal diseases.

During its early years, WHO was primarily concerned with epidemic control, standardization and quality control of vaccines, and administration of the International Sanitary Regulations. Among the acute enteric infections, cholera received the greatest attention because of its propensity for rapid epidemic spread. When the seventh pandemic of cholera began in 1961, WHO responded with a greatly expanded programme of activities which included cooperation with countries in training and control efforts, and research on treatment and prevention, especially vaccine development. At the same time, numerous training courses were held on enteric infections and a series of controlled field trials established the degree of protection conferred by existing typhoid and paratyphoid vaccines. In 1970, when the cholera pandemic spread to Africa, the emergency assistance programme was reactivated, with increasing attention to the provision of appropriate treatment, especially oral rehydration therapy, rather than the supply of ineffective vaccines. The requirement of cholera vaccination for international travel in the International Health Regulations was abolished in 1973 by the World Health Assembly. Another public health problem of importance during the 1970s was the increase in antibiotic resistance of enteric bacteria, especially Shigella dysenteriae 1 and Salmonella typhi, first in Central America and Mexico and later in Asia. There was a notable acceleration in research on diarrhoeal disease and especially on cholera during this period, with the discovery of several new viral and bacterial agents of diarrhoea, advances in knowledge of intestinal immunity indicating that better protection might be achieved with oral vaccines, and the demonstration of the effectiveness of a single formulation of oral rehydration salts (ORS) in the treatment of all diarrhoeas including cholera.(ABSTRACT TRUNCATED AT 250 WORDS)

Cholera↗