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Biomedical subjects

D García

Publications and source records attributed to D García.

At least 55 records · Page 3Linked to original sources
PubMed1996

Antiinflammatory effects of different extracts and harpagoside isolated from Scrophularia frutescens L.

Most species belonging to Scrophularia genus had been used as antiinflammatory drugs by the folk medicine. The phenylpropanoids are considered to be the active principles of these drugs with antiinflammatory action by different Authors, especially harpagoside and harpagide. In this report, the antiinflammatory effects of Scrophularia frutescens L. (Scrophulariaceae) was studied and the iridoid glucoside harpagoside has been evidenced and isolated for the first time from this plant. Aqueous extract, methanolic extract and harpagoside, isolated from the methanolic extract, were tested for antiinflammatory activity on the rat paw oedema. The results obtained showed that the aqueous extract has a small but significant antiinflammatory effect on carrageenan-induced oedema test, while methanolic extract has a lower antiinflammatory activity and the activity of the isolated harpagoside is remarkably low. Thus, the conclusion may be that S. frutescens L. is a potential antiiflammatory agent but its activity is not due to harpagoside.

Animals↗
PubMed1995

Interleukin-6 chaperones in blood.

There is increasing evidence that many, perhaps all, cytokines have a soluble form of their receptor in the systemic circulation at all times. There is also evidence that endogenous antibodies to some cytokines, including IL-6, are also found in blood. Initially these findings were evaluated in vitro, and associated with inhibiting the respective effects of those cytokines. However, it is now becoming clear that the in vivo effects are paradoxically the reverse of what is seen in vitro. As we have explained here for IL-6 it is evident that many or all of these molecules that bind and/or associate with IL-6 maintain this molecule in the systemic circulation and constitute a reservoir of masked, but potentially active IL-6. The mode of regulation of the biological activity of these IL-6-associated complexes remains unknown, but needs to be uncovered in order to pharmacologically exploit many of the potentially beneficial effects or to prevent any potential pathological effects.

Animals↗
PubMed1994

Sustained high levels of circulating chaperoned interleukin-6 after active specific cancer immunotherapy.

In a phase 1 study of recombinant interleukin-6 (rIL-6) in patients with advanced solid tumors (n = 15), we discovered that the endogenous IL-6 levels, in pretreatment plasma or serum samples, were distributed into two groups. One set of patients (designated "type 1"; n = 9) was characterized by low plasma IL-6 levels (48 to 1,700 pg/mL) as measured using enzyme-linked immunosorbent assays (ELISA) for IL-6. In the second set of patients (designated "type 2"; n = 6), IL-6 ELISAs showed high levels of plasma IL-6 (50 to 600 ng/mL). Neither group had detectable B9 hybridoma cell growth factor activity associated with the IL-6 in their pretreatment plasma or serum. Plasma C-reactive protein (CRP) levels were markedly elevated in type II patients suggesting that the circulating IL-6 was biologically active in vivo. In both groups of patients there was a small but significant increase in B9 activity in the plasma within three hours after rIL-6 administration (n = 5). Gel filtration profiles showed that circulating IL-6 in type 1 patients, 15 to 120 minutes after rIL-6 administration was of approximate mass 20 to 40 kD, whereas in type 2 patients, the IL-6 before and after exogenous rIL-6 administration was indistinguishable and was of an approximate mass of 200 kD. IL-6 immunoaffinity purification of the 200 kD complexes showed these to contain multiple isoforms of IL-6 (14 to 31 kD) and the soluble IL-6 receptor (sIL-6R; 50 to 55 kD). A distinguishing clinical history was that all of the type 2 patients had been actively immunized with an anti-idiotypic monoclonal antibody (MoAb) (MK2-23) 3 to 12 months before initiation of this study for advanced melanoma. An analysis of the plasma IL-6 content in other melanoma patients (n = 16) during antiidiotypic MoAb immunization indicated that marked (up to 600 ng/mL) and sustained (several months) elevations of circulating "chaperoned" IL-6 were induced by active immunization regimens.

Antibodies, Monoclonal↗
PubMed1994

[Duodenal diverticula associated with acute pancreatitis].

UNLABELLED: The purpose of this study was to assess the role of duodenal diverticula as an etiologic factor in acute pancreatitis. METHODS AND PATIENTS: We have reviewed the records of patients with diverticulum of the second portion of the duodenum diagnosed by gastroduodenal radiology or endoscopy during the period 1991-1992 in our hospital. As a control group we studied patients without duodenal diverticulum. All subjects underwent biliary-pancreatic ultrasonography. Thirty-eight patients had a duodenal diverticulum and gallstones 36 had a duodenal diverticulum but no gallstones; 21 had gallstones alone; and, finally, 42 patients were free of duodenal diverticulum and gallstones. RESULTS: Patients with duodenal diverticula had a greater prevalence of gallstones than those without (51.3% VS 33.3%, p < 0.005). Of the thirty-eight patients with duodenal diverticula and gallstones 23.7% had acute pancreatitis. None of the 21 patients without duodenal diverticulum and with gallstones had acute pancreatitis, p < 0.05. The median age of patients with duodenal diverticulum without gallstones was 64.25 years, range 34-85, and the age of those with duodenal diverticulum and gallstones was 70.4 years, range 37-87, p < 0.05. CONCLUSIONS: 1) Gallstones may cause acute pancreatitis in patients with D2 duodenal diverticula. 2) Patients with a D2 duodenal diverticulum frequently have gallstones. 3) The fact that the age of patients with duodenal diverticulum was lower than that of patients with both duodenal diverticulum and gallstones suggests that duodenal diverticula may play a role in the pathogenesis of gallstones.

Acute Disease↗
PubMed1994

[Molecular epidemiology of subgroups and serotypes of rotavirus in children less than 4 years of age in the city of Maracaibo with a diarrheal syndrome].

Between november 1989 and january 1991, two hundred stool samples were obtained from children under 4 years of age, hospitalized with diarrhea. Sixty stool samples from apparently healthy children were used as controls. Rotavirus infections were diagnosed in 28 (14%) specimens using two enzyme immunoassays, (Abbott Laboratories' kit and monoclonal antibodies). PAGE, ELISA and PCR were used to determine electropherotypes, subgroups and serotypes respectively. The study of electropherotypes detected two migration patterns: a short one in 4 samples (14.3%) and a long pattern in 16 cases (57.1%). These results were verified by a specific subgroup monoclonal antibodies ELISA. The polymerase chain reaction showed that serotype 1 accounted for 46.4% of positive samples, while serotypes 3 and 4 present in 3.6% and 7.4% of the specimens respectively. Serotype 2 was not detected and 42.8% samples were untypable. Males between 0 and 12 months of age were the most affected. There was no correlation between human rotavirus serotypes, subgroups and electropherotypes, and age of the patients. All detected genetic variants were present in children under two years of age.

Child, Preschool↗
PubMed1993

[Surveillance of nosocomial infection at a regional++ hospital. Results of incidence and prevalence studies in a 2 years' experience].

BACKGROUND: The most appropriate methods for surveillance of nosocomial infection (NI) in hospitals with less than 250 beds remain to be elucidated. The aims of this study were to investigate the differences between the results found in a study in incidence (IS) and in another concerning prevalence (PS) carried out in a county hospital and study the experience in the application of a collection method of incidental cases through a survey. METHODS: For 2 years IS trimestrally accumulated and simultaneously PS trimestrally were applied for global surveillance and for type of NI as well as for knowing the etiology of the same. In both types of study all the hospital patients were included. RESULTS: The accumulated incidence of patients with NI over the 2 years was 3.9% (3.6 in the first 12 months and 4.1 in the 12 remaining months) and the global prevalence was 7.5%. The global trend of NI was that of an increase in both studies. The most frequent NI in both studies were surgical wound and urinary infection. PS did not detect the least frequent NI. The etiologic agents of NI were similar in both studies. The survey undertaken for the detection of NI demonstrated 61% sensitivity, 98% specificity and a positive prediction value of 94%. CONCLUSIONS: In small hospitals global prevalence studies may be useful for surveillance of the most frequent nosocomial infections. The results obtained by incidence studies were less variable and better reflect the trend of nosocomial infection. A survey used as a study method of incidence for the collection of cases of nosocomial infection loses sensitivity over time.

Cohort Studies↗
PubMed1991

Temporal distribution of human rotavirus serotypes 1,2,3, and 4 in Venezuelan children with gastroenteritis during 1979-1989.

The temporal distribution and clinical severity of rotavirus VP7 serotypes 1, 2, 3, and 4 recovered from 427 Venezuelan children with acute gastroenteritis over a period of 11 years were studied. Rotavirus VP7 serotype was established by ELISA serotyping in 298 (69.78%) of the specimens while the serotype of the remaining 129 (30.21%) samples could not be determined. Of the specimens typed, 85 (19.90% of the total) were serotype 1, 43 (10.07%) were serotype 2, 105 (24.59%) were serotype 3, and 65 (15.22%) were serotype 4. Yearly changes in the frequency of individual serotypes were observed. The predominance of a single serotype with minor contribution from others was noted every year. In this study, serotype 1 appears to induce a less severe illness in comparison with serotypes 2, 3, and 4. No apparent association between the proportion of each serotype and the children's age were found.

Antigens, Viral↗
PubMed1991

Realimentation of dehydrated children with acute diarrhea: comparison of cow's milk to a chicken-based formula.

A randomized, prospective study was performed on 73 male children between 3 and 14 months of age with mild to moderate dehydration caused by acute diarrhea, and who were rehydrated with WHO-ORS, and then at 4 h after admission were fed either cow's milk or an experimental diet based on chicken, plantain, and coconut oil. There were no statistically significant differences in the admission characteristics. The group of children fed cow's milk had a higher total volume of diarrheic evacuations (p less than 0.05). The average duration of diarrhea was 20 h shorter in the group of infants on the milk-free formula. A significant correlation was observed between the volume of diarrhea and the WHO-ORS consumed during the first 48 h, but not to the volume of diet intake.

Acute Disease↗
PubMed1991

[Multicenter study of the Rosco-Neisseria system for the identification of pathogenic neisserias and Branhamella catarrhalis].

The commercial Rosco-Neisseria system was evaluated in the identification of 228 oxidase-positive Gram-negative diplococci and it was compared with conventional tests. The procedure detects gamma-glutamyl aminopeptidase, ONPG, tributyrin hydrolysis, and sensitivity to the disk of 10 micrograms of colistin. A correct identification was obtained in the 65 strains of Neisseria gonorrhoeae, the 33 of N. meningitidis, the 12 of N. lactamica, and the 56 of B. catarrhalis. The method was also able to discriminate 54 out of the 62 strains of nonpathogenic Neisseria. However, the 7 strains of Neisseria polysaccharea and one strain of N. subflava biovar perflava were erroneously identified as N. gonorrhoeae. None of the latter was superoxol positive in contrast with the 100% of cases of gonococcal strains. The Rosco-Neisseria system is simple and inexpensive but it should be applied on specimens that grow on selective media for gonococci (such as Thayer-Martin and others) and it should be complemented by superoxol test.

Bacterial Infections↗
PubMed1991

[Usefulness of warning flags in the handling of biological samples in an emergency room].

The present study evaluates the utility of biohazard precautions labels for identifying biological samples of patients with probable severe transmissible infectious diseases. The study was performed in a total of 633 patients in the emergency department of a General Hospital. In an anonymous way we determine the presence or absence of serological markers of HIV and hepatitis B infection (HBsAg) and we evaluated the labeling of the sample. Our results demonstrate the very low usefulness of this common procedure: a total of 54.5% of HIV positive patients and 87.5% of those positive to HBsAg were not marked correctly. We discuss the necessity of using universal precautions instead of labeling samples in the current way.

Blood Specimen Collection↗
PubMed1987

Characterization of rotaviruses isolated from pigs with diarrhoea in Venezuela.

The prevalence of porcine rotavirus infection was studied in 15 different herds located in the north-western region of Venezuela. The presence of rotavirus was studied by direct electron microscopy (EM) and by an enzyme-linked immunosorbent assay (ELISA). From 136 samples analyzed during the six months of the study (September 1983-February 1984), 38 (27.9%) were found to be positive for rotaviruses, with infection more common in animals that were 4-6 weeks old. Atypical rotaviruses were not detected in any of the samples examined. Most rotavirus positive specimens were subgrouped using specific monoclonal antibodies in an ELISA test. The majority of the samples (26 out of 38) were found to exhibit Subgroup I antigenicity. Only two specimens, collected from the same herd in two consecutive months, were found to belong to Subgroup II. To characterize further the circulating rotaviruses, electrophoretic analysis of the RNA genome was performed on samples selected from nine different herds. Great variability in the RNA electropherotypes was observed. No correlation was found between subgroup specificity and the migration of the two smaller segments (Genes 10 and 11), as has been described for human rotaviruses.

Animals↗
PubMed1987

Preliminary characterization of Escherichia coli isolated from pigs with diarrhoea in Venezuela.

The aetiology of neonatal porcine diarrhoea was studied in 15 different herds located in the north-western region of Venezuela. Of 56 strains of Escherichia coli analyzed, 16 (28.6%) were shown to produce heat-stable (STa) enterotoxin, as detected by infant mouse assay. Only four of these STa+ isolates also possessed the K88 pilus antigen, two were 987P+ and none possessed the K99 antigen, leaving 10 STa+ samples in which no pilus antigen was identified. Among the 40 STa negative samples were six K88+ specimens, one K99+, four 987P+, one which reacted as K88+ + K99+ and one K88+ + 987P+. Considering as pathogenic any strain showing at least one of the characters studied, pathogenic E. coli were detected with an overall frequency of 42.9%, being more prevalent during the second week of life. An electrophoretic analysis of the plasmid content of the field isolates of E. coli, revealed the presence of numerous species of extrachromosomal DNA, although no direction association could be made between a particular plasmid and any of the pathogenic characteristics identified. Results of Southern blot analysis indicate that the STa enterotoxin was preferentially encoded within an endemic plasmid of 4.9 Md. Other plasmids present in the E. coli isolates could be related to antibiotic resistance. With the exception of one strain, all E. coli isolates were resistant to more than one of the nine drugs tested; multiresistant E. coli were frequently isolated, including four strains which were resistant to seven antibiotics.

Animals↗