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A Llanos

Publications and source records attributed to A Llanos.

At least 19 recordsLinked to original sources
PubMed2005

American tegumentary leishmaniasis: antigen-gene polymorphism, taxonomy and clinical pleomorphism.

Multi-locus enzyme electrophoresis is the current gold standard for the genetic characterisation of Leishmania. However, this method is time-consuming and, more importantly, cannot be directly applied to parasites present in host tissue. PCR-based methods represent an ideal alternative but, to date, a multi-locus analysis has not been applied to the same sample. This has now been achieved with a sample of 55 neotropical isolates (Leishmania (Viannia) braziliensis, L. (V.) peruviana, L. (V.) guyanensis, L. (V.) lainsoni and L. (L.) amazonensis), using five different genes as targets, four of which encoded major Leishmania antigens (gp63, Hsp70, H2B and Cpb). Our multi-locus approach strongly supports the current taxonomy and demonstrates a highly robust method of distinguishing different strains. Within L. (V.) braziliensis, we did not encounter so far specific genetic differences between parasites isolated from cutaneous and mucosal lesions. Interestingly, results provided by each of the different antigen-genes in the species considered, were different, suggesting different selective pressures. Our work emphasises the need for a multi-disciplinary approach to study the clinical pleomorphism of leishmaniasis.

Animals↗
PubMed2001

Insulin homeostasis in the extremely low birth weight infant.

The need to improve the nutritional status of extremely low birth weight infants has resulted in a higher incidence of problems related to glucose intolerance. The inability of the newborn to inhibit gluconeogenesis in response to a glucose infusion has been postulated as an important determinant of the hyperglycemia observed in extremely low birth weight infants. The 2 proposed mechanisms to explain this finding include inappropriate secretion of insulin by the pancreas and decrease sensitivity of the liver to the gluco-regulatory effect of insulin. The capacity of extremely low birth weight infants to oxidize glucose at higher rates, and the positive effect that insulin may have in glucose utilization and tolerance, support the use of insulin in the prevention and treatment of hyperglycemia. Continuous infusion of insulin appears to be safe for the treatment of hyperglycemia, based on the available studies. However, the effectiveness of insulin treatment needs to be critically tested further before it can be implemented in routine clinical practice.

Diabetes Mellitus↗
PubMed1998

Cardiorespiratory responses to acute hypoxemia in the chronically catheterized fetal llama at 0.7-0.9 of gestation.

The adult llama (Lama glama) has several compensatory mechanisms that allow it to successfully survive at high altitude. Llama fetuses at 0.6-0.7 of gestation, and near-term llama fetuses studied close to surgery, did not increase cerebral blood flow and decreased cerebral oxygen delivery during acute hypoxemia. It is not known whether these responses were the result of immaturity or surgical stress. The aim of this study was to determine whether the lack of increase in cerebral blood flow and the decrease in cerebral oxygen delivery during hypoxemia in the fetal llama is characteristic of this high-altitude species near term, and under nonstressed conditions. We chronically catheterized 7 llamas and their fetuses near to term, at 0.7-0.9 of gestation. Fetal cardiac output, cerebral and regional blood flows, systemic blood pressure, heart rate, pH, and blood gases, organ vascular resistances and organ oxygen deliveries were determined at least 4 days after surgery, both during the basal state and after 1 hr of acute fetal hypoxemia. During hypoxemia the llama fetus did not increase cerebral blood flow and markedly decreased its cerebral oxygen delivery. There was also a marked decrease in kidney blood flow and oxygen delivery. These results indicate that, in contrast to fetuses of lowland species, the fetal llama does not increase the cerebral blood flow during hypoxemia, suggesting specific cellular mechanisms to preserve brain integrity during oxygen limitation.

Acclimatization↗
PubMed1995

Micro-evolutionary implications of allozymic and morphometric variations in sealworms Pseudoterranova sp. (Ascaridoidea: Anisakidae) among sympatric hosts from the southeastern Pacific Ocean.

We found significant morphometric and electrophoretic differences between sealworm larvae collected from four sympatric fish host species off the central coast of Chile. The South American sea lion, Otaria byronia, is a suitable host and most likely the only definitive host species in the study area. Morphological patterns of caudal papillae in adult males collected from sea lions and electrophoretic evidence from larvae and adults substantiate our conclusion that they belong to just one, new species yet to be described. The genetic and morphometric differences found between sealworm larvae from sympatric fish hosts may be due to selective pressures arising from the internal environment of the intermediate hosts, although they may serve only for passing sequential filters along the life cycle. The discussion deals with the roles that definitive and intermediate hosts may play in the micro-evolutionary processes of sealworms.

Animals↗
PubMed1995

Renal function in the chronically cannulated fetal llama: comparison with studies in the ovine fetus.

Samples of maternal and fetal plasma, fetal urine, and amniotic fluid were collected from 8 chronically cannulated pregnant llamas, in the last third of gestation. The samples were obtained for up to 18 days post-surgery. Osmolality, sodium (Na), potassium (K), chloride (Cl), and urea were measured on 40 samples collected on days 1, 2, 3, 4-5, 6-7, 8-9, and 10-19. The osmolalities of maternal and fetal plasma, fetal urine and amniotic fluid, averaged over these 7 time periods, were, respectively, 312 +/- 2, 311 +/- 1, 484 +/- 14, and 317 +/- 1 mosmol kg-1. Values are given as mean +/- s.e. The major differences from fetal fluid values in the ovine fetus (from previously published values) were the higher osmolality and urea concentration of llama fetal urine. Urine flow rate measured in 6 fetuses, 4.5-6.5 kg body weight, was 5.8 +/- 0.4 mliter h-1; urea clearance rate was 55.5 +/- 11.8 mliter h-1. Glomerular filtration rate (GFR), measured with 51Cr-EDTA in 5 fetuses on 1-4 occasions, was 111.4 +/- 23.3 mliter h-1. Fractional reabsorptions (FR) of Na, K and Cl were 97.9 +/- 1, 75.9 +/- 13.5 and 97.7 +/- 0.4% respectively. The GFR (25 mliter kg-1 h-1) and urine flow rate (1 mL kg-1 h-1) were less than half and about one-tenth the respective values in ovine fetuses. As Na reabsorption is the major oxygen-consuming activity of the kidney, the llama fetal kidney requires only half the oxygen needed by the ovine fetal kidney to reabsorb the filtered sodium load. The reason for the formation of hypertonic, rather than hypotonic, urine in the fetal llama may be due to both greater morphological maturity of the kidney and the excretion of as yet unidentified osmotically active organic substances.

Amniotic Fluid↗
PubMed1991

Effect of salt supplementation on amphotericin B nephrotoxicity.

It has been suggested that salt loading protects against amphotericin B-induced nephrotoxicity. The influence of saline loading on the nephrotoxic response to amphotericin B (50 mg/dose given i.v. over 4 hr 3 X/week for 10 weeks) was assessed in two groups of ten patients each who were diagnosed with mucocutaneous leishmaniasis. Patients were randomized to receive either 1 liter of 0.9% saline or 1 liter of 5% dextrose in water, administered i.v. over one hour in a double-blinded manner, directly prior to amphotericin B administration. Renal function was monitored on a weekly basis two days after the last dose of amphotericin B. Baseline characteristics were similar in both groups except for a slightly higher serum creatinine concentration (Cr) in the saline group (0.8 +/- 0.05 vs. 0.6 +/- 0.04 mg/dl). Baseline sodium (Na) excretion was relatively high (262 +/- 23 mmol/day in the dextrose group and 224 +/- 17 mmol/day in the saline group). None of the patients sustained an increase in Cr to values greater than 1.7 mg/dl. Although mean Cr remained within normal, there was a significant difference between the two groups over the ten week period, with the dextrose group sustaining a significant increase in Cr and the saline group remaining unchanged. Serum potassium (K) levels fell in both groups necessitating oral K supplementation. The saline group required significantly greater amounts of K supplementation to maintain a normal serum K. Amphotericin B caused a rapid reduction in the acidification ability of the kidney in response to an ammonium chloride load. Under these conditions, the saline group had a poorer ability to acidify the urine.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

[The risk factors for hepatitis B virus infection in hospital personnel].

Viral hepatitis is one of the leading causes of disease around the world. In Latin America is a severe public health problem. We conducted a case-control study in the Cayetano Heredia Hospital, Lima, Perú, seeking for risk factors for hepatitis B infection. We found 0.41% of frequency of HBsAg and 8.13% of anti-HBs in the 492 persons screened. Contact with blood was confirmed as a risk factor for hepatitis B infection; disposable needle-wash was also identified as a major risk factor. The personnel of the Sterilization Room is also in high risk for the infection. The nurse-aid personnel was also identified as a high-risk group. We suggest that the needle wash is a risk factor very easy to remove, and also stopping the rotation of the auxiliary personnel could reduce the incidence of the infection in the personnel at risk.

Age Factors↗
PubMed1989

[Risk factors for hepatitis B virus infection among hospital staff].

Viral Hepatitis is one of the leading causes of disease around the world. In Latin America is a severe public health problem. We conducted a case-control study in the Cayetano Heredia Hospital, Lima-Perú, seeking for risk factors for Hepatitis B infection. We found 0.41% of frequency of HBsAg and 8.13% of anti-HBs in the 492 persons screened. Contact with blood was confirmed as a risk factor for Hepatitis B infection; disposable needle-wash was also identified as a major risk factor. The personnel of the Sterilization Room is also in high risk for the infection. The nurse-aid personnel was also identified as a high risk group. We suggest that the needle wash is a risk factor very easy to remove, and also stopping the rotation of the auxiliary personnel could reduce the incidence of the infection in the personnel at risk.

Hepatitis B↗
PubMed1987

Characterization of Leishmania species from Peru.

Twenty-six isolates of Leishmania parasites of Peruvian origin were studied by isoenzyme electrophoresis of four marker enzymes (ASAT, ALAT, G6PD and GPI), kinetoplast DNA hybridization and monoclonal antibody binding and compared with marker strains of the New World organisms L. b. braziliensis, L. b. guyanensis, L. m. mexicana and L. m. amazonensis. 12 of the isolates studied were of Andean origin; 11 of these were isolated from patients with Andean cutaneous leishmaniasis. The organisms originating from the Peruvian Amazonian forest were isolated from patients with cutaneous (12 cases) or mucocutaneous (2 cases) leishmaniasis. One of the Andean isolates was obtained from an infected phlebotomine vector. 25 of the new isolates were identified as L. braziliensis ssp. according to the three techniques employed. The results of monoclonal antibody binding showed that 23 of the isolates were indistinguishable from L. b. braziliensis. Two isolates identified as L. braziliensis ssp. according to their isoenzyme profiles and k-DNA hybridization patterns could not be classified at the subspecies level. The isolate obtained from the phlebotomine vector could not be identified. No evidence of the existence of parasites of the L. mexicana complex in Peruvian territory was found in this study. The results obtained show a remarkable similarity between Leishmania of Andean origin and L. b. braziliensis.

Alanine Transaminase↗
PubMed1987

Differences in the lipid peroxidative status, cytochrome P-450 content and microsomal oxygen consumption between right and left lobes of the liver in fetal sheep. Comparison with maternal liver.

The existence of the ductus venosus in mammalian fetal liver determines a different blood flow in the right and left lobes. This asymmetry is associated to a decrease in oxygen delivery to the right lobe. Some stages in oxygen metabolism are related to the formation of free radicals that can induce cellular damage dependent on the tissue oxygen concentration and on the activity of the enzymatic and non enzymatic systems involved in the tissue protection. In the present study, the differences in the lipid peroxidative status and some parameters related to the protection against oxygen toxicity between both lobes in the sheep fetal liver were analyzed and compared to the same parameters in the dam liver.

Animals↗
PubMed1979

Plasma lecithin: cholesterol acyltransferase activity in normal full-term newborn infants.

Plasma lecithin: cholesterol acyltransferase (LCAT) activity was studied in 100 normal full-term newborn infants during the first few days of life. The present study shows that plasma LCAT activity present at birth-though at much lower levels than those in the maternal blood-undergoes a fall after birth followed by a rise. It is also shown that the activity of the plasma LCAT enzyme is not strictly linked to the esterification of plasma-free cholesterol in the first three days after birth. However, from the fourth day onwards, there was a good correlation between LCAT activity and esterification of plasma-free cholesterol. The results suggest that plasma LCAT in newborn infants could be partially derived from maternal sources.

Cholesterol↗
PubMedDate not supplied

[Quantitative cultures from catheters, using the Brun Buisson technique].

The objective of this collaborative work carried out in the Fundación Favaloro and the Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia, was to determine optimal conditions for incubation (time and atmosphere) of quantitative cultures of catheters processed according to the technique of vortex agitation (Brun Buisson method). From 689 processed catheters, 551 yielded negative cultures. From the 138 positive cultures, 125 yielded monomicrobial cultures and 13 polimicrobial cultures (total number of microorganisms was 151). In the last situation each micoorganism was considered on an individual basis. A total of 58 episodes of catheter related bacteremias occurred, being 52 monomicrobial and 6 polimicrobial (total number of microorganisms was 64). When colony counts were compared in aerobic and in 5-10% CO2 atmospheres, a very good correlation was obtained (p = 0.27; r2 = 0.9268). No advantage was observed by incubating plates for more than 48 hours. Colony counts performed at the second versus the third day, and at the second day versus the seventh, gave very good correlation (p = 0.10 and r2 = 0.9996; p = 0.31 and r2 = 0.9995, respectively).

Aerobiosis↗