Biomedical subjects

S Muñoz

Publications and source records attributed to S Muñoz.

At least 55 records · Page 3Linked to original sources

PubMed1997

[Clinical experience with an alpha glucosidase inhibitor (acarbose) in the treatment of non-insulin-dependent diabetes. Multicenter study].

BACKGROUND: Acarbose, an alpha glucosidase inhibitor is a drug used in the treatment of non insulin dependent diabetes mellitus, that interferes with the intestinal absorption of monosaccharides. AIM: To study the effect of acarbose in non insulin dependent diabetic patients that had an inadequate metabolic control with diet and sulphonylureas. PATIENTS AND METHODS: Diabetic patients received acarbose, 150 mg/day during four weeks and this dose was increased to 300 mg/day during 3 months. Afterwards, patients were followed for a period of 12 weeks without acarbose. Fasting and post-prandial blood glucose and glycosilated hemoglobin were measured sequentially during the study. RESULTS: Eighty five patients were recruited for the study but 64 complied with the treatment protocol. The age of these patients was 56 +/- 8.8 years old, their diabetes duration was 7.8 +/- 8.8 years and their body mass index was 27.6 +/- 3.6 kg/m2. During acarbose treatment, glycosilated hemoglobin decreased from 8.36 +/- 1.33 to 7.71+ 1.7% (p < 0.001), fasting blood glucose decreased from 173 +/- 48 to 159 +/- 59 mg/dl (p < 0.03) and post-prandial blood glucose decreased from 254 +/- 80 to 241 +/- 80 mg/dl (NS). After discontinuing acarbose glycosilated hemoglobin and blood glucose levels returned to basal levels. Body weight and blood pressure did not change during the treatment period. Fifty nine patients had gastrointestinal symptoms (meteorism, flatulence and abdominal distention) that were mild in 59% and moderate in 39%. Episodes of hypoglycemia were not observed. CONCLUSIONS: Acarbose, associated to sulphonylureas is an effective drug to reduce blood glucose and glycosilated hemoglobin levels in patients with non insulin dependent diabetes.

Acarbose↗

PubMed1997

[Biochemical markers and methods to assess insulin resistance in normal, obese and hyperandrogenic women].

BACKGROUND: Euglycemic or hyperglycemic clamp and the frequently sampled i.v. glucose tolerance test are the most frequently used methods to assess insulin resistance. However, both are expensive and cumbersome. AIM: To evaluate the relative or discriminatory usefulness of sex hormone binding globulin (SHBG), dehydroepiandrosterone sulphate (DHEAS) and insulin like growth factor binding protein 1 (IGFBP-1) as markers of insulin resistance and to estimate the tissue sensitivity to insulin by means of the insulin tolerance test (ITT) and the frequently sampled i.v. glucose tolerance test (IVGTT) in normal, obese and hyperandrogenic women. SUBJECTS AND METHODS: Six normal, 6 obese and 12 hyperandrogenic women of similar ages, were studied. In two consecutive days, the ITT and the IVGTT were performed and a basal blood sample was obtained to measure SHBG, DHEAS and IGFBP-1. Insulin sensitivity was calculated as the blood glucose slope in the ITT and with the minimal model of Bergman in the IVGTT. RESULTS: Insulin sensitivity, measured with ITT was 0.58 (0.53-0.63) in normal, 0.38 (0.05-0.59) in obese and 0.20 (0.0-0.36) in hyperandrogenic women. The figures for the IVGTT were 7.97 (4.1-15.4), 2.41 (0.81-4.89) and 1.1 (0.46-1.88), respectively. Both methods had a positive correlation coefficient of 0.792 (p < 0.001). SHBG was 87.0 m 37.9 and 18.3 nmol/l in normal, obese and hyperandrogenic women, respectively (p < 0.09). IGFBP-1 values were 3.0, 2.1 and 1.6 ng/ml respectively (p < 0.05). DHEAS values were 132, 190 and 206 ug/dl, respectively (ND). CONCLUSIONS: ITT is a simple and reliable method to assess insulin sensitivity. SHBG discriminates subjects with different levels of insulin sensitivity. Since it is easy to measure, it could be used as a marker on insulin sensitivity.

Adult↗

PubMed1997

[Effects of metformin on insulin resistance in obese and hyperandrogenic women].

BACKGROUND: Metformin is a biguanide often used in obese diabetics that improves tissue sensitivity to insulin. AIM: To assess the effects of metformin on tissue insulin sensitivity in obese and hyperandrogenic women. PATIENTS AND METHODS: Eight obese and eight obese and hyperandrogenic women received metformin 850 mg orally during 12 weeks. Before and at the end of the treatment period, an insulin tolerance test to measure insulin sensitivity was performed and blood was drawn to measure sex hormone binding globulin (SHBG), dehydroepiandrosterone sulphate (DHEAS), testosterone, triglycerides, total and HDL cholesterol. The free androgen index was calculated for each sample. RESULTS: After metformin treatment, the insulin sensitivity index improved from 0.38 (0.05-0.5) to 0.43 (0.25-0.59) in obese women and from 0.2 (0-0.36) to 0.3 (0.06-0.4) in obese and hyperandrogenic women. SHBG increased and total cholesterol and triglycerides decreased significantly in both groups. No other significant changes were observed. CONCLUSIONS: Metformin has a favorable effect on tissue sensitivity to insulin, SHBG and serum lipids in obese and hyperandrogenic women.

Adult↗

PubMed1997

[24 hour esophageal pH monitoring in healthy individuals].

BACKGROUND: Twenty four hour esophageal pH monitoring is considered the gold standard investigation for gastroesophageal reflux disease. This test allows the linkage of symptoms to occurrence of reflux episodes and is used to record the frequency of reflux and the amount of esophageal acid exposure that results from reflux. AIM: To know the acid esophageal exposure in healthy Chilean subjects. SUBJECTS AND METHODS: Thirty two asymptomatic volunteers aged 30 to 76 years old (24 female) underwent 24 h esophageal pH monitoring with a digitrapper Mark II Gold (Synectics Medical Stockholm). Total reflux episodes, episodes greater than 5 min, the longest reflux episode, the lapse with pH < 5, the percentage of time with pH < 4 and the score suggested by Johnson and De Mester were analyzed. RESULTS: There was a mean of 20.9 reflux episodes per subject and 0.1 episodes of more than 5 min. The longest episode lasted 8 min and the mean total time of acid reflux was 10 min/24 h. Total percentage pH below 4 was 0.7% and the mean score was 3.2. No subject reported symptoms during the test. CONCLUSIONS: For practical purposes, the upper limit of normal acid exposure in Chilean subjects is 2.4%.

Adult↗

PubMed1996

Activity of trimethoprim/sulfamethoxazole plus polymyxin B against multiresistant Stenotrophomonas maltophilia.

The inhibitory activity of eight antibiotics and the inhibitory and bactericidal activities of combinations of trimethoprim/sulfamethoxazole (TMP/SMX) plus three fixed concentrations of polymyxin B (0.01 microgram/ml, 0.1 microgram/ml and 0.5 microgram/ml) against 30 multi-resistant strains of Stenotrophomonas maltophilia were tested. Polymyxin B at 0.01 microgram/ml modified the inhibitory activity of TMP/SMX against only 40% of strains. At 0.1 microgram/ml and 0.5 microgram/ml, polymyxin B enhanced the inhibitory activity of TMP/SMX activity against all strains. Polymyxin B enhanced the bactericidal activity of TMP/SMX only at concentrations near the minimum inhibitory concentration of polymyxin B alone.

Anti-Bacterial Agents↗

PubMed1996

[Insulin tolerance test. A useful test to determine insulin resistance in obese hyperandrogenic women].

BACKGROUND: Insulin tolerance test is a simple method to measure insulin resistance that has a good correlation with glucose clamp studies. AIM: To use the insulin tolerance test to detect differences in insulin sensitivity between healthy and obese hyperandrogenic women and to correlate its results with those of the minimal model intravenous glucose tolerance test. PATIENTS AND METHODS: Five healthy women aged 27 +/- 7 years old with a body mass index of 21 +/- 2 kg/m2 and six hyperandrogenic women aged 25 +/- 4 years old with a body mass index of 40 +/- 5 kg/m2 were studied after a 10 hours fast. For the insulin tolerance test 0.1 U/kg of crystalline insulin were injected intravenously and blood samples were drawn to measure glucose at -5,0,3,5,10 and 15 min. after the injection. Insulin resistance was calculated using the slope of descending blood glucose levels (SI1). For the intravenous glucose tolerance test, 29 blood glucose samples were obtained after an intravenous injection of 0.3 g glucose/kg followed by an injection of 0.02 U/kg of crystalline insulin. Insulin sensitivity (SI2) was calculated using Bergman's minimal model. RESULTS: Healthy women had a SI1 of 0.58 (range 0.53-0.63) and a SI2 of 7.9 x 10(-4) x min-1/microU/ml (range 4.15-9.11). For hyperandrogenic women were 0.18 (range 0.06-0.29) and 0.9 x 10(-4) x min-1/microU/ml (range 0.46-1.79), respectively. Both methods had a positive correlation coefficient of 0.859 (p < 0.001). CONCLUSIONS: Insulin tolerance test is a good method to measure insulin resistance and has a good correlation with the frequently sampled intravenous glucose tolerance test.

Adult↗

PubMed1996

[Cardiovascular risk factors in 15 patients in chronic hemodialysis in Temuco city. Descriptive comparison with the general Chilean population].

BACKGROUND: Patients in chronic hemodialysis have a high mortality due to cardiovascular diseases. AIM: To study cardiovascular risk factors and nutritional status in a group of patients in maintenance hemodialysis. PATIENTS AND METHODS: Body mass index, blood pressure, serum levels of totals cholesterol, HDL cholesterol, triglycerides and albumin were measured in 15 patients (8 male) in maintenance hemodialysis. Data were compared with available figures for the normal Chilean population. RESULTS: Age ranged from 33 to 60 years old in female patients and from 22 to 63 years old in males. Thirteen subjects (87%) had high blood pressure, all had HDL cholesterol levels below 35 mg/dl, four (27%) had a total cholesterol over 200 mg/dl, three had triglyceride levels over 200 m/dl, two (13%) smoked and none were diabetic. Mean body mass index was normal, albumin levels were 4.16 and 4.02 g/dl and serum creatinine was 11.64 and 9.68 mg/dl in males and females respectively. The estimated prevalence of high blood pressure, hypercholesterolemia and smoking in the general Chilean population range from 9 to 22%, from 50 to 52% and from 45 to 51% respectively. CONCLUSIONS: This group of patients has a high frequency of high blood pressure and low HDL cholesterol levels.

Adult↗

PubMed1995

Isolation and characterization of a novel perchloric acid-soluble protein inhibiting cell-free protein synthesis.

We found a novel protein in the postmitochondria supernatant fraction of rat liver, which is soluble in 5% perchloric acid and strongly inhibits protein synthesis in a rabbit reticulocyte lysate system. The protein extracted from the supernatant fraction with 5% perchloric acid was purified by ammonium sulfate fractionation and CM-Sephadex chromatography. The protein was shown to consist of two identical subunits with a molecular mass of 14 kDa. By immunoscreening with the rabbit antisera against the protein, a cDNA encoding the protein was cloned and sequenced. The cDNA contained an open reading frame of 411 base pairs encoding a 136-amino acid protein with a molecular mass of 14,149 Da. The deduced amino acid sequence was completely identical with that constructed from all of the above peptides. Interestingly, the perchloric acid-soluble protein inhibited cell-free protein synthesis in the rabbit reticulocyte lysate system in a different manner from RNase A. The protein is likely to inhibit an initiation stage of cell-free protein synthesis. Among the rat tissues tested, the protein was located only in liver and kidney. These findings are the first report on a new inhibitor that may be involved in the regulation of protein synthesis in those tissues.

Amino Acid Sequence↗

PubMed1995

Biochemical, immunological, and biological characterization of Trypanosoma cruzi populations of the Andean north of Chile.

Twenty-one Trypanosoma cruzi stocks isolated from Triatoma infestans and humans of the Chilean Andean highlands were studied at the genotypic level by schizodeme and molecular karyotype analyses, which allowed a clear distinction of the parasites from those hosts. A phenotypical characterization was performed by proteolytic activity after electrophoretic fractionation without discrimination among the stocks. Metacyclic trypomastigotes obtained in vitro proved to be infective to Swiss mice and the study of immune response and biological behavior was assessed. Of a total of 21 T. cruzi stocks, only 11 proved to be infective in mice due to difficulties in obtaining metacyclic trypomastigotes with the parasite populations isolated from humans. Western blot analysis revealed a complex immune response even in the first days postinfection with each T. cruzi strain studied. Antigenic recognition by each immune serum is characteristic, although several major and common antigens were detected. Lytic antibodies were studied by the in vitro complement-mediated lytic assay using purified metacyclic trypomastigotes as target cells. All the T. cruzi isolates tested induced lytic antibodies in this experimental model. Parasitemias were moderate and characteristic for each T. cruzi strain. Results are compared with metacyclic forms of the infective and pathogenic Tulahuen strain.

Animals↗

PubMed1995

Differential effects of fibrates on the acyl composition of microsomal phospholipids in rats.

1. The time-course and comparative effects of treatment with clofibrate (CFB), bezafibrate (BFB), and gemfibrozil (GFB) on the acyl composition of the main microsomal phospholipids, i.e. phosphatidylcholine and phosphatidylethanolamine, have been studied in male Sprague-Dawley rats. 2. The administration of the three fibrates caused a strong peroxisomal induction and a hypolipidaemic effect. Concerning the changes in acyl composition, CFB and BFB behaved in a similar way, with differences which could be attributed to their different potency as peroxisome inducers, whereas GFB showed a somewhat distinct profile. 3. The three drugs increased the relative content of palmitic, palmitoleic and oleic acids, whereas the levels of stearic acid and also those of long chain, highly unsaturated fatty acids docosatetraenoic, docosapentaenoic and docosahexaenoic acids were reduced. In general, these effects appeared from the first day of treatment and were highly correlated with peroxisomal proliferation. In addition, they were more evident in the phosphatidylcholine than in the phosphatidylethanolamine fraction. 4. Fibrates increased total monounsaturated fatty acids, whereas a decrease in total polyunsaturated fatty acids in the phosphatidylcholine fraction was observed in CFB- and BFB-, but not in GFB-treated rats. Clear differences appeared between CFB and BFB on the one hand, and GFB on the other when the influence of fibrate treatment on the molar percentages of linoleic, eicosatrienoic, arachidonic and mead acids was analyzed. 5. GFB increased linoleic acid content in phosphatidylethanolamine, whereas CFB and BFB decreased its level in both phospholipid fractions. In contrast, CFB and BFB enhanced eicosatrienoic and mead acids in both fractions and arachidonic acid in phosphatidylethanolamine, whereas GFB had practically no effect.

Animals↗

PubMed1994

Inhibition of tumoral cell respiration and growth by nordihydroguaiaretic acid.

The effects of nordihydroguaiaretic acid (NDGA), best known as an inhibitor of lipoxygenase activities, on the culture growth, oxygen consumption, ATP level, viability, and redox state of some electron carriers of intact TA3 and 786A ascites tumor cells have been studied. NDGA inhibited the respiration rate of these two tumor cell lines by preventing electron flow through the respiratory chain. Consequently, ATP levels, cell viability and culture growth rates were decreased. NDGA did not noticeably inhibit electron flow through both cytochrome oxidase and ubiquinone-cytochrome b-c1 complex. Also, the presence of NDGA changed to redox state of NAD(P)+ to a more reduced level, and the redox states of ubiquinone, cytochrome b and cytochromes c + c1 changed to a more oxidized level. These observations suggest that the electron transport in the tumor mitochondria was inhibited by NDGA at the NADH-dehydrogenase-ubiquinone level (energy-conserving site 1). As a consequence, mitochondrial ATP synthesis would be interrupted. This event could be related to the cytotoxic effect of NDGA.

Adenosine Triphosphate↗

PubMed1994

Purification and characterization of a ribonuclease from Aspergillus giganteus IFO 5818, the gigantin. Immunological and enzymic comparison with alphasarcin.

A protein has been isolated from a culture medium of Aspergillus giganteus IFO 5818 (gigantin) and purified by ion-exchange chromatography successively on DEAE-cellulose and carboxymethyl-cellulose, and gel-filtration chromatography on Biogel P10. With a high purity, gigantin was found to be a non-glycosylated basic protein with a relative molecular mass of 17000 +/- 200 determined in PAGE/SDS. Gigantin was able to digest the synthetic homopolymers of nucleic acids poly(A), poly(I), poly(C) and poly(U). The catalytic action has an optimal pH around 7.0, an optimal temperature at 45-55 degrees C and can be inhibited by cations. Gigantin activity, analyzed as its capacity to hydrolyze RNA from yeast, was comparable to that of alphasarcin, a similar biochemical protein produced by the strain A. giganteus MDH 18894. A study of the substrate specificity for alphasarcin indicated a preference for poly(A) and poly(I), while gigantin had greater activity on poly(C) and poly(U). The cross reaction of gigantin with a rabbit antiserum to alphasarcin suggests a high sequence similarity between both proteins. However, gigantin is immunologically distinguishable from alphasarcin as alphasarcin antiserum detects epitopes in alphasarcin that are not present in gigantin.

Aspergillus↗

PubMed1994

Incidence and prevalence of ulcerative colitis and Crohn's disease in urban and rural areas of Spain from 1981 to 1988.

We retrospectively investigated the annual incidence and prevalence of inflammatory bowel disease (IBD) from 1981 to 1988 in an urban and a rural area of central Spain. Two hundred and eighty-one patients presented with IBD; 193 ulcerative colitis (UC) and 88 Crohn's disease (CD) (prevalence 43.4/100,000 and 19.8/100,000, respectively). Of these patients, 168 were diagnosed for the first time during the study period. One hundred and eleven UC and 57 CD (incidence 3.16/100,000 and 1.61/100,000 respectively). Within the urban area, the UC incidence was 3.15/100,000 and the CD 1.87/100,000. In the rural area, the incidence for the UC was 3.25/100,000 and 0.86/100,000 for the CD. No sex differences were found. The incidence rates have increased significantly (p < 0.05) for CD in the study period. However, for UC rates did not change. During 1986-1988, the patient's age at the time of diagnosis was significantly lower than that of 1981-1983 (p < 0.05).

Adult↗

PubMed1994

[Highly homogeneous Trypanosoma cruzi populations in a low endemic region for Chagas disease: importance in the pathogenesis of Chagas disease in Chile].

Trypanosoma cruzi from 23 chronic and acute cases of Chagas disease were isolated and further characterized. They displayed a remarkable similarity, after typification by schizodeme analysis using restriction endonuclease Eco Ri. All T cruzi isolates belonged to the isoenzymatic Zymodeme 2 Bol. These findings were corroborated analyzing cases from families with demonstrated congenital transmission. The acute cases were newborns or offspring of infected mothers or patients with AIDS. All T cruzi strains isolated in these cases were very similar with almost identical schizodemes. Patients with AIDS had severe clinical manifestations whereas children with congenital infections had a great variety of clinical symptoms. In chronic cases, little clinical differences were observed for the different T cruzi strains. It is concluded that there is a low correlation between the T cruzi strain and the clinical prognosis of Chagas disease, being of greater relevance the host's genetic background and immune response.

Adult↗

PubMed1993

Myopathy with mitochondrial alterations in patients with primary biliary cirrhosis and antimitochondrial antibodies.

OBJECTIVE: To describe a syndrome of severe progressive myopathy, cardiomyopathy, and gastrointestinal dysmotility in 2 patients with asymptomatic primary biliary cirrhosis (PBC) and circulating antimitochondrial autoantibodies, and to review pertinent literature concerning this syndrome. METHODS: Clinical, electrophysiologic, serologic, and pathologic studies of the 2 affected patients were conducted. RESULTS: Skeletal muscle involvement was manifested by progressive weakness of the proximal muscles, marked diaphragmatic dysfunction with consequent hypoventilation and respiratory failure, and moderately elevated levels of muscle-associated enzymes. Serum from both patients contained antimitochondrial antibodies that reacted with components of the mitochondrial keto acid dehydrogenase enzyme complex. Results of electromyography were consistent with a myopathic process. The microscopic and ultrastructural changes in the skeletal muscles were distinct from those of typical myositis, and were notable for striking subsarcolemmal aggregation of abnormal mitochondria in the absence of significant inflammation. CONCLUSION: Severe skeletal muscle, cardiac, and gastrointestinal pathology with abnormalities of the muscle mitochondria develops in a subset of patients with mild PBC and antimitochondrial antibodies. The pathogenesis of this syndrome is unclear, but may be related to the presence of the antimitochondrial autoantibodies.

Adult↗

PubMed1993

Successful treatment of Trypanosoma cruzi encephalitis in a patient with hemophilia and AIDS.

Although the frequency of infection with the human immunodeficiency virus (HIV) is increasing dramatically in areas where Trypanosoma cruzi is endemic, trypanosomiasis has been rarely reported in persons with HIV infection or AIDS. Persons with hemophilia who receive multiple blood product transfusions from blood banks with little or no screening for infectious agents are at particularly high risk for infections with both HIV and T. cruzi. We describe the case of a person with hemophilia who was infected by blood transfusion with HIV and T. cruzi and in whom a multifocal, necrotic trypanosomal encephalitis was demonstrated by brain biopsy and electron microscopy. Treatment with benznidazole followed by that with itraconazole and fluconazole was associated with significant clinical and radiographic improvement.

AIDS-Related Opportunistic Infections↗

PubMed1993

[Movement and tranquility in 19th century Aesthetics].

The nineteenth century sees the rise of the bourgeoisie to social and political power. The values of this class increased the attention paid to certain branches of the medical sciences, such as for example hygiene. A set of rules and methods to achieve better health and, at the same time, to come closer to the perfect image of man described by writers of aesthetics, often taking classical Greece as a point of reference, are believed to be found in these branches. In these strategies physical exercise plays a role which is positively valued as much by hygienists as by philosophers, some of whose works are studied in this article.

Exercise↗

PubMed1993

Characterization of Trypanosoma cruzi populations by several molecular markers supports a clonal mode of reproduction.

Chilean T. cruzi populations from different endemic areas and transmission cycles were characterized at several biochemical levels, to mention: hybridization with kinetoplast DNA probes, molecular karyotype, isoenzyme studies and kinetoplast DNA restriction fragment length polymorphism. Furthermore, an immunological approach with immune sera from Balb/c infected mice with different T. cruzi populations was used to differentiate among parasite types by the in vitro complement-mediated lysis assay. Parasite grouping by the above described methods allows to classify T. cruzi populations on a very defined number, suggesting that they have a clonal structure.

Animals↗