Biomedical subjects

S Galvez

Publications and source records attributed to S Galvez.

6 recordsLinked to original sources

PubMed1995

Monocotyledonous C4 NADP(+)-malate dehydrogenase is efficiently synthesized, targeted to chloroplasts and processed to an active form in transgenic plants of the C3 dicotyledon tobacco.

Chloroplastic NADP(+)-malate dehydrogenase (cpMDH, EC 1.1.1.82) is a key enzyme in the carbon-fixation pathway of some C4 plants such as the monocotyledons maize or Sorghum. We have expressed cpMDH from Sorghum vulgare Pers. in transgenic tobacco (Nicotiana tabacum L.) (a dicotyledonous C3 plant) by using a gene composed of the Sorghum cpMDH cDNA under the control of cauliflower mosaic virus 35S promoter. High steady-state levels of cpMDH mRNA were observed in isogenic dihaploid transgenic tobacco lines. Sorghum cpMDH protein was detected in transgenic leaf extracts, where a threefold higher cpMDH activity could be measured, compared with control tobacco leaves. The recombinant protein was identical in molecular mass and in N-terminal sequence to Sorghum cpMDH. The tobacco cpMDH protein which has a distinct N-terminal sequence, could not be detected in transgenic plants. Immunocytochemical analyses showed that Sorghum cpMDH was specifically localized in transgenic tobacco chloroplasts. These data indicate that Sorghum cpMDH preprotein was efficiently synthesized, transported into and processed in tobacco chloroplasts. Thus, C3-C4 photosynthesis specialization or monocotyledon-dicotyledon evolution did not affect the chloroplastic protein-import machinery. The higher levels of cpMDH in transgenic leaves resulted in an increase of L-malate content, suggesting that carbon metabolism was altered by the expression of the Sorghum enzyme.

Amino Acid Sequence↗

PubMed1992

Development and evaluation of a rapid, simple, sensitive, monoclonal antibody-based co-agglutination test for direct detection of Vibrio cholerae 01.

Cholera epidemics caused by Vibrio cholerae 01 continue to represent a major public health concern in many developing countries. A rapid and simple test kit for the detection of V. cholerae 01 has been developed. The kit, CholeraScreen is a monoclonal antibody-based, co-agglutination test and is used directly with stool specimens. It does not include culturing the specimen and is performed without the need for sophisticated laboratory equipment. Specificity of the test was demonstrated, using 118 reference cultures, to which cross-reactions were not observed. Preliminary results of field trials carried out in Guatemala and Bangladesh demonstrated that the test is equally sensitive as conventional culture methods in detecting V. cholerae and, in many cases, more sensitive. The CholeraScreen test is simple, specific, and does not require culturing procedures, making it suitable for direct detection of cells of V. cholerae in clinical specimens, even in the field. Also, the test requires less than five minutes to complete.

Agglutination Tests↗

PubMed1989

The nucleus basalis of Meynert in 20 definite cases of Creutzfeldt-Jakob disease.

The population of neurons and the neuronal size in the nucleus basalis of Meynert (nbM) were studied in 20 patients with definite Creutzfeldt-Jakob disease (CJD). When compared with a normal control group, the 20 CJD brains showed a significant loss of neurons and reduction of neuronal size, mainly in the middle level of the nbM and mostly affecting the right side. Since these findings show some parallelism with the amount of cortical damage and given the scarce gliosis and spongiosis found in only six of the 20 CJD brains, we postulate that the involvement of the nbM in CJD is a retrograde abnormality secondary to the damage of the neocortex.

Adult↗

PubMed1987

Preoperative left ventricular dysfunction and operative risks in coronary bypass surgery.

Preoperative left ventricular function variables were evaluated as potential risk factors for peroperative and postoperative complications in 183 consecutive patients undergoing coronary bypass surgery. Fifty-six patients had no abnormal criteria and 127 had at least one criterion (AN). The incidence of history of infarction was significantly greater in the AN (71.6 percent) than in the N (39.6 percent) group (p less than 0.04). During the early postoperative course, N and AN differentiated significantly in (1) the need for inotropic therapy (II vs 30 percent, p less than 0.05); (2) intra-aortic balloon pump (0 vs 13 percent); (3) arrhythmias (20 and 40 percent, p less than 0.002); and (4) stay in the Intensive Care Unit (2.3 +/- 0.8 and 3.9 +/- 2 days, p less than 0.01). Perioperative necrosis and mortality were not different. During a follow-up period of two years, N and AN did not show any difference in mortality and recurrence of angina.

Arrhythmias, Cardiac↗

PubMed1980

Descriptive epidemiology of Creutzfeldt-Jakob disease in Chile.

Descriptive epidemiological data are presented from a survey of 35 cases of Creutzfeldt-Jakob disease (CJD) that occurred in Chile in the period 1955 to 1977. The average mortality in Chile (0.31 deaths per 1 million) and in urban Santiago (0.73 deaths per 1 million) is compared with data reported from other countries. An increasing incidence in recent years is probably related to a greater awareness of the disease. The familial occurrence of CJD in nine patients from five affected families is described, and its analysis suggests a genetically determined susceptibility with incubation periods of more than 30 years. Horizontal transmission of the disease may have occurred in one patient in whom the disease developed 13 years after the patient married into a family with seven other affected members.

Adult↗

PubMed1979

The concentration of alpha-1-antitrypsin in cerebrospinal fluid and serum in a series of 40 intracranial tumors.

Forty patients with histologically proved intracranial tumors were submitted to preoperative lumbar and venous punctures. The concentration of alpha-1-antitrypsin in the serum and in cerebrospinal fluid was determined by radial immunodiffusion technique. In the series, both serum and cerebrospinal fluid alpha-1-antitrypsin concentrations are significantly higher than the mean normal values. No statistical differences are observed in serum alpha-1-antitrypsin levels between benign and malignant tumors, but cerebrospinal fluid alpha-1-antitrypsin is significantly increased in the group of malignant tumors if cases undergoing steroid treatment are excluded. The diagnostic value of alpha-1-antitrypsin determinations in groups of patients with intracranial tumors is suggested.

Adolescent↗