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Biomedical subjects

N Rodriguez

Publications and source records attributed to N Rodriguez.

At least 55 records · Page 3Linked to original sources
PubMed1994

Posttraumatic stress disorder in a clinical sample of adults sexually abused as children.

Forty-seven help-seeking, adult survivors of childhood sexual abuse (CSA) were assessed to examine the relationship between the level of CSA exposure and the subsequent development of posttraumatic stress disorder. CSA exposure was operationalized to include the overall level of exposure, frequency and duration of the abuse, age of onset, use of force, perceived life threat, and the occurrence of penetration. Participants were administered standardized measures of PTSD, including the Structured Clinical Interview of DSM-III-R (SCID). On the SCID, 69% of the survivors met full DSM-III-R criteria for PTSD. Significant correlations were found between several overall exposure measures and PTSD diagnostic status and the intensity of PTSD symptomatology. Similar relationships were identified with the duration and frequency of the abuse, the age of onset, and the use of force. This study is important in that it utilized standardized measures of PTSD and found a significant incidence of PTSD among adult CSA survivors.

Adolescent↗
PubMed1994

Cutaneous leishmaniasis in Tachira State, Venezuela.

Cutaneous and mucocutaneous leishmaniases are widely spread in the mountainous Andean regions of South America. In Venezuela, these regions consist of the coffee-growing states of Trujillo, Merida and Tachira. Entomological and parasitological investigations in three geographically different climatic zones (Lomas Bajas, Delicias and La Grita) in Tachira state have shown a predominance of the sandfly species Lutzomyia spinicrassa (verrucarum group) and two Leishmania species, Leishmania mexicana and Leishmania braziliensis. Two transmission cycles appear to occur: a peridomestic cycle in Lomas Bajas and a sylvatic one in Delicias and La Grita.

Adolescent↗
PubMed1994

Vectors of cutaneous leishmaniasis in north-central Venezuela.

An entomological survey was undertaken from January 1991 to February 1992 in El Ingenio, Miranda State, Venezuela, an endemic area of cutaneous leishmaniasis: prevalence of 10.7 cases per 100,000 inhabitants. A total of 4863 female sandflies (Phlebotominae) of fourteen species were collected in Shannon traps, then dissected and examined for leishmanial infections. Lutzomyia ovallesi (85.4%) and Lu. gomezi (11.2%) were the predominant anthropophilic species of sandfly. Fifty-one (1.19%) Lu.ovallesi and two (0.47%) Lu.gomezi had natural infection with Leishmania promastigotes. Identification of the parasites was done by using the polymerase chain reaction (PCR) and DNA hybridization. Two isolates from Lu.gomezi and forty-nine from Lu.ovallesi were typed as Leishmania braziliensis and three of the latter reacted with Le.mexicana also. This is the first report of Lu.gomezi with parasites typed as Le.braziliensis. We concluded that Lu.ovallesi is the primary vector of cutaneous leishmaniasis in the north-central area of Venezuela and Lu.gomezi should be regarded as an additional vector.

Animals↗
PubMed1994

Coexistence of two species of Leishmania in the digestive tract of the vector Lutzomyia ovallesi.

Leishmania isolated from the digestive tract of a naturally infected Lutzomyia ovallesi sand fly were cultured in blood agar for rapid growth, cloning, and subsequent identification through schizodeme analysis, dot-blot hybridization, use of monoclonal antibodies with various specificities and absorbed polyclonal antibodies. Twenty-three clones isolated from the primary culture were identified. The results showed that parasites belonging to some clones corresponded to the L. mexicana complex, while others belonged to the L. braziliensis complex. These results clearly establish the coexistence of two Leishmania species in the digestive tract of a single Lu. ovallesi sand fly.

Animals↗
PubMed1993

Rupture and migration of the venous segment of LeVeen shunt: an unreported complication.

The LeVeen peritoneovenous shunt has been used for nearly 20 yr in the treatment of refractory ascites due to liver cirrhosis. However, the technique encompasses a high incidence of serious complications. We report the case of a 59-yr-old man presenting with right pulmonary artery embolization caused by ruptured venous segment of a LeVeen shunt. After localizing it arteriographically, we were able to satisfactorily remove the segment by tying it up with a catheter introduced through the femoral vein.

Equipment Failure↗
PubMed1991

Nonoperative management of splenic injuries.

The traditional management of splenic trauma has undergone major revision in recent years. Given the physiological importance of the spleen, certain controversy has arisen regarding the most appropriate method of managing this type of trauma. Nonoperative therapy in children has proven to be successful not only in the case of kidney lesions but also for splenic lesions. Nonoperative management carried out in the authors' hospital on a group of 56 patients (49 adults and seven children over the age of 7 years) has proved successful in 37 cases. The success of this technique requires a well-formulated protocol, diagnostic methods (ultrasound and computed tomography), rigorous patient control in the emergency room during the initial phase (first 48 hours), the availability of a medical team if surgical intervention becomes necessary (persistent or recurrent hemorrhage), and complementary measures which facilitate the cicatrization of the splenic injury (bed rest, antibiotic therapy).

Adolescent↗
PubMed1990

Effect of the ingestion of an extract from Bauhinia monandra seeds on rats.

Bauhinia monandra is a leguminous plant that would be used in human nutrition, however it shows a high hemagglutinating activity against trypsin-treated erythrocytes of rabbit, 2 ml of a NaCl-solution extract of the seeds was given to a group of rats for 10 days. Intestinal disaccharidase activity was determined. Histopathological and histochemical examinations were also performed. Lectins from Bauhinia monandra seeds did not cause any visible intestinal damage even when they seem to be able to bind to the enterocyte brush border. The low disaccharidase activity in the membrane and enterocyte fractions, which represent the enzyme synthesis level, indicates that lectins could reduce the synthesis of these enzymes rather than inhibit the active sites of the enzymes. This effect could be in turn related with the binding action of lectins, because no effect of the autoclaved extract on the disaccharidase activity was observed.

Animals↗
PubMed1989

Contribution of insulin resistance to catabolic effect of prednisone on leucine metabolism in humans.

To determine the role insulin resistance may play in the catabolic effect of high-dose prednisone therapy, healthy volunteers were studied on four occasions with the hormone-clamp technique at two insulin infusion rates. Subjects were studied after 5 days of prednisone (60 mg/day) or no steroid treatment and were infused with somatostatin, glucagon, growth hormone, [3H]glucose, [14C]leucine, and insulin (0.1 or 0.2 mU.kg-1.min-1). At each rate of insulin infusion, the rate of leucine oxidation was increased (P less than .001) after steroid treatment. Leucine flux, an indicator of whole-body proteolysis, was similar in the presence or absence of steroid treatment (2.26 +/- 0.08 vs. 2.13 +/- 0.04 mumol.kg-1.min-1, respectively) at the lower rate of insulin infusion but was higher during steroid treatment (2.18 +/- 0.06 vs. 1.84 +/- 0.13 mumol.kg-1.min-1) at the 0.2-mU.kg-1.min-1 insulin infusion. Steroid pretreatment had no significant effect on the nonoxidative rates of leucine disappearance. These data provide strong evidence that the protein wasting associated with glucocorticosteroid therapy is in part the result of steroid-induced resistance to the antiproteolytic effect of insulin and an increase in the oxidation (and thus wasting) of one essential amino acid, leucine.

Adult↗
PubMed1986

Trioctanoin infusion increases in vivo leucine oxidation: a lesson in isotope modeling.

We have reported that infusion of trioctanoin in conscious dogs had little effect on leucine oxidation but decreased the rate of appearance (Ra) and interconversion of leucine and its alpha-keto acid, alpha-ketoisocaproate (KIC). To verify that these conclusions were independent of the leucine tracers and isotope models employed, the studies were repeated using [1-14C]leucine and [4,5-3H]KIC rather than [1-14C]KIC and [4,5-3H]leucine. In the present study, leucine oxidation calculated using the plasma [14C]leucine or [14C]KIC specific activities (SA) increased nearly twofold (P less than 0.001) during trioctanoin infusion in direct contrast to our previous results. When the data from either study were analyzed using the plasma SA of the leucine moiety reciprocal to the infused tracer as a potential indicator of the intracellular leucine SA, similar conclusions were obtained from either study: trioctanoin infusion in conscious dogs appears to increase whole-body leucine oxidation and does not decrease proteolysis. These studies challenge the validity of previously used isotope models of leucine metabolism and suggest that the plasma KIC SA during infusion of labeled leucine may most accurately reflect changes in whole-body leucine metabolism.

Animals↗
PubMed1984

Detection of a pancreatic cancer-associated antigen (DU-PAN-2 antigen) in serum and ascites of patients with adenocarcinoma.

A competition radioimmunoassay was developed, utilizing a murine monoclonal antibody to human pancreatic adenocarcinoma cells. Immunoblotting of a standard antigen preparation from either serum or ascites fluid after electrophoresis in 1% agarose showed that the specific DU-PAN-2 activity resided in two major high molecular weight bands. DU-PAN-2 antigen levels were expressed as arbitrary units based on a standard partially purified antigen preparation. The inhibition curve with standard antigen was reproducible (SD less than 10%) and essentially linear from 25 to 200 units/ml. The mean DU-PAN-2 antigen concentration for the sera from 126 normal individuals was 81 units/ml. Sera from pediatric patients with malignancy had a mean of 127 units/ml, while nasopharyngeal, stage III melanoma, and ovarian carcinoma patients had means of 89, 92, and 119 units/ml, respectively. All values in normal subjects as well as the melanoma, nasopharyngeal, ovarian, and pediatric cancer patients were less than 400 units/ml. Intermediate antigen levels were detected in patients with alimentary tract malignancies. Eight of 20 gastric cancer and 8 of 76 colorectal carcinoma patients and 3 patients with benign or nonmalignant gastrointestinal tract disease had DU-PAN-2 values exceeding 400 units/ml. Ascites fluids from 6/6 and pancreatic juice from 2/2 pancreatic cancer patients had values greater than 750 units/ml. Serum from 68% of the 89 pancreatic cancer patients tested had DU-PAN-2 antigen levels greater than 400 units/ml. The mean serum value in this patient population was 4888 units/ml.

Adenocarcinoma↗
PubMed1981

Cinoxacin in urinary tract infections. Theoretical and practical considerations.

In dogs we found that cinoxacin concentrations in prostatic tissue, secretion, and interstitial fluid always were lower than the simultaneous serum concentrations, during constant infusion experiments. The cinoxacin concentrations in urethral and vaginal secretions were similar to those found in prostatic interstitial fluid, approximately one third to one fourth of the simultaneous serum concentrations. The concentrations of cinoxacin in human prostatic tissue after single or multiple doses of 500 mg. were found to be in the range of minimum inhibitory concentrations for most microorganisms found in urinary tract infections. Cinoxacin was found to have a half-life of 2.7 hours in patients with normal renal function, but increased to 8.5 hours in patients with impaired renal function. We found little or no drug accumulation during a seven-day treatment of patients with impaired renal function.

Animals↗
PubMed1980

Production and secretion of Leishmania braziliensis proteins.

The kinetics of secretion of proteins by Leishmania braziliensis was followed by incorporation of [3H]leucine into macromolecules produced by the cells which are released into the growth medium. About 10% of the total protein synthesized by actively growing cells is secreted. Cycloheximide (100 microgram/ml) and puromycin (0.5 mM) inhibited the incorporation of labelled leucine by 85 and 99%, respectively. The secreted proteins do not seem to result from cell lysis since, first, the kinetics of production are linear and, secondly, less than 1% of thymidine or uridine incorporated by the cells is found in the medium. Cells grown with [3H]leucine and then transferred to fresh medium show two phases of secretion. During the first six hours, it is slow and reaches a plateau. The release increases about ten-fold during the next six hours. An analysis of the secreted material showed that following precipitation with methanol and sodium acetate, three isotopically labelled peaks were eluted from Sephadex G-120-150. The first of these, containing 50% of the radioactivity, did not react with anti-leishmanial serum, while the last two did. Since the last two fractions could be labelled with [3H]glucosamine as well as [3H]leucine it is suggested that they are glycoprotein in nature and are similar to the products released by other species of Leishmania.

Animals↗
PubMed1979

Influence of probenecid on serum levels and urinary excretion of cinoxacin.

Serum levels and urinary excretion of cinoxacin were examined in healthy individuals after a two-step intravenous infusion in the presence and absence of probenecid. After dosing cinoxacin alone, steady-state serum levels were approached in 1 h and were maintained for an additional 2 h with a reduced infusion rate. After probenecid pretreatment, serum levels of cinoxacin continued to increase during 3 h of infusion, reaching levels approximately double those obtained with cinoxacin alone. The mean elimination half-life of cinoxacin from serum was increased from 1.3 to 3.5 h in the presence of probenecid, and renal clearance was significantly reduced, with 46% of dosed drug appearing in 7-h urines of probenecid-treated subjects compared with 68% in subjects receiving cinoxacin alone. Probenecid had no apparent influence on cinoxacin distribution in the body but caused a significant decrease in the rate of cinoxacin extrarenal elimination, possibly due to competition for a common metabolic pathway.

Adult↗
PubMedDate not supplied

Use of an ATP-supplemented medium for the conservation of human semen and the effect of caffeine on the motility of preserved sperm. Results in artificial insemination.

Human semen can be preserved at 4 degrees C in an artificial medium containing 15% ATP-MgCl2 for up to 5 d. This method has been applied to samples from subjects with either normal or abnormal semen. After the conservation period the recovery of sperm motility observed was good when low doses of caffeine (3.5 or 7.0 mM) were added.

Adenosine Triphosphate↗
PubMedDate not supplied

The epidemiology and control of leishmaniasis in Andean countries.

This paper reviews the current knowledge of leishmaniasis epidemiology in Venezuela, Colombia, Ecuador, Peru, and Bolivia. In all 5 countries leishmaniasis is endemic in both the Andean highlands and the Amazon basin. The sandfly vectors belong to subgenera Helcocyrtomyia, Nyssomiya, Lutzomyia, and Psychodopygus, and the Verrucarum group. Most human infections are caused by Leishmania in the Viannia subgenus. Human Leishmania infections cause cutaneous lesions, with a minority of L. (Viannia) infections leading to mucocutaneous leishmaniasis. Visceral leishmaniasis and diffuse cutaneous leishmaniasis are both rare. In each country a significant proportion of Leishmania transmission is in or around houses, often close to coffee or cacao plantations. Reservoir hosts for domestic transmission cycles are uncertain. The paper first addresses the burden of disease caused by leishmaniasis, focusing on both incidence rates and on the variability in symptoms. Such information should provide a rational basis for prioritizing control resources, and for selecting therapy regimes. Secondly, we describe the variation in transmission ecology, outlining those variables which might affect the prevention strategies. Finally, we look at the current control strategies and review the recent studies on control.

Animals↗