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Biomedical subjects

A Arteaga

Publications and source records attributed to A Arteaga.

At least 19 recordsLinked to original sources
PubMed2005

Canine hyperadrenocorticism: effects of trilostane on parathyroid hormone, calcium and phosphate concentrations.

OBJECTIVES: To determine the effects of treating canine hyperadrenocorticism (HAC) on parathyroid hormone (PTH), calcium and phosphate concentrations in dogs. METHODS: Serum calcium, phosphate and PTH concentrations were analysed in 22 dogs with HAC before treatment with trilostane and at a median of 210 days after commencing treatment. Pretreatment data were compared with data from an age- and weight-matched group of hospitalised patients, and post-treatment data were compared with pretreatment data. RESULTS: PTH and phosphate concentrations were significantly higher in dogs with HAC compared with control dogs. PTH concentrations reduced significantly with treatment, such that there was no longer a difference between the HAC and control groups. Phosphate concentrations also reduced significantly with treatment but there was still a significant difference between those in dogs with HAC and control dogs. Despite no significant difference between calcium concentrations in the pretreatment HAC and control groups, calcium concentrations increased significantly with treatment. CLINICAL SIGNIFICANCE: These results show that adrenal secondary hyperparathyroidism resolves with treatment and suggest that increased calcium and phosphate levels have a role in its pathogenesis.

3-Hydroxysteroid Dehydrogenases↗
PubMed2005

Haptoglobin concentrations in dogs undergoing trilostane treatment for hyperadrenocorticism.

BACKGROUND: Increased concentrations of haptoglobin (Hp), a moderate acute phase protein, have been demonstrated in dogs with hyperadrenocorticism (HAC). Monitoring serum concentrations of Hp in hyperadrenocorticoid dogs before and after trilostane administration may provide valuable information on the response to therapy. OBJECTIVE: The aim of this study was to measure Hp concentrations in dogs with spontaneously occurring HAC at the time of diagnosis and after treatment with trilostane. METHODS: Serum Hp concentration was measured using an automatic biochemical assay based on Hp-hemoglobin binding and utilizing SB-7 reagent in 12 dogs with spontaneous HAC before and after treatment with trilostane (30 or 60 mg PO q 12-24 h). Post-treatment Hp concentrations were measured at the time the owner reported an improvement in clinical signs. Pretreatment and post-treatment Hp values were compared with reference values and with values from 4 healthy control dogs. RESULTS: Two dogs with HAC had pretreatment Hp values within the reference interval; 10 dogs had moderate (n = 8) or marked (n = 2) increases in Hp concentration. After treatment with trilostane, Hp concentration remained within the reference interval (n = 2), decreased to within the reference interval (n = 3), or remained moderately increased (n = 7; 3-10 g/L). Overall, a significant decrease was observed in Hp concentration after trilostane treatment compared with pretreatment values (P <.005). Both untreated and treated dogs with HAC had significantly higher Hp concentrations (P <.001) when compared with control dogs. CONCLUSIONS: Clinical control of HAC did not closely relate to serum Hp concentration. Further studies are required to assess whether this is because of inadequate control of disease or because a build-up of cortisol precursors or secondary effects of HAC affect Hp concentration.

Adrenocortical Hyperfunction↗
PubMed2003

Effect of proinflammatory cytokines (IL-6, TNF-alpha, IL-1beta) on hemodynamic performance during orthotopic liver transplantation.

BACKGROUND: Proinflammatory cytokines (IL-6, IL-1beta, TNF-alpha) released during liver transplantation may affect hemodynamic stability. The aim of the present study was to analyze the association between IL-6, TNF-alpha, and IL-1beta and systemic vascular resistance during the phases of liver transplantation. MATERIAL AND METHODS: The proinflammatory cytokines IL-6, IL-1beta, and TNF-alpha were analyzed in the blood of 20 consecutive patients who underwent transplantation. Blood samples were drawn from the pulmonary artery at serial times during surgery. Hemodynamic parameters were determined using a cardiac output monitor. Correlations between parameters were analyzed using the Spearman's rho and Kendall's tau-b methods. RESULTS: Both in the vena cava and the pulmonary artery, significant association was observed between basal values of IL-6 during hepatectomy and systemic vascular resistance during the phases of liver transplantation: hepatectomy phase (r=.76, P=.02), anhepatic phase (r=.78, P=.03) and reperfusion phase (r=.87, P=.005). CONCLUSIONS: Basal values of IL-6 may be considered a prognostic factor for hemodynamic performance during the phases of liver transplantation.

Biomarkers↗
PubMed2003

Association between anatomopathologic graft disorders during reperfusion and vena cava sIL-2r in orthotopic liver transplantation.

UNLABELLED: Graft ischemia-reperfusion injury during orthotopic liver transplantation (OLT) is associated with anatomic and pathologic disorders in the graft, which may cause initial dysfunction. The object of this paper was to evaluate sIL-2r as an indicator of liver damage during graft reperfusion. MATERIAL AND METHODS: Blood samples were drawn from 20 consecutive patients who required OLT secondary to chronic end-stage insufficiency various sites (portal vein, vena cava, pulmonary artery) and during different surgical phases. Following centrifugation and storage at -70 degrees C, sIL-2r was quantitated by chemiluminescence (Immulite, EURO/DPC). In addition biopsies were graded from 0 to III according to the anatomic and pathologic findings. Base excess and ammonia were measured to evaluate the function of the new liver. STATISTICAL ANALYSES: Parameter associations were explored using Spearman's Rho and Kendall's Tau-b methods. RESULTS: There was a correlation between the degree of graft preservation and sIL-2R both during vena cava reperfusion (r=.0591, P=.05) and for the initial 2 hours after reperfusion (r=0.61, P=.062). CONCLUSION: sIL-2r levels drawn from the vena cava after graft reperfusion are associated with its degree of injury.

Drug Therapy, Combination↗
PubMed2001

The proportion of beef bulls in western Canada with mature spermiograms at 11 to 15 months of age.

A study was conducted to determine the proportion of yearling beef bulls that have mature spermiograms at 11 to 15 months of age, and to evaluate the relationship between semen quality traits, age, and scrotal circumference. Semen samples and data on sperm motility and scrotal circumference measurements were obtained from 1641 bulls of 14 breeds. Criteria for a satisfactory spermiogram included sperm concentration > or = 400 x 10(6)/mL, > or = 60% progressively motile sperm, and > or = 70% morphologically normal sperm. The mean scrotal circumference measurements for all bulls combined were 33.4, 34.4, 35.2, 35.8, and 35.3 cm at 11, 12, 13, 14, and 15 months of age, respectively. The percentage of bulls with matures spermiograms at 11, 12, 13, 14, and 15 months of age were 20%, 30%, 51%, 52%, and 61%, respectively. There was a high positive correlation (r = 0.9) between the number of bulls with > or = 70% normal sperm and scrotal circumference measurement. The main types of morphologic defects observed in immature bulls were proximal droplets and midpiece defects.

Age Factors↗
PubMed1998

[Dyslipidemias in renal diseases: pathogenesis and treatment].

Patients with renal diseases like nephrotic syndrome, chronic renal failure (uremia) and renal transplantation frequently present disturbances of lipid metabolisms, however their pathogenesis is partially understood. Moreover, cardiovascular diseases are responsible for many deaths in these patients. Although the effect of the dyslipidemias in the development of atherosclerosis in renal diseases is not clear, they probably play a role. Since actually the survival of these patients is substantial, it is important to manage them appropriately with regard to their dyslipidemias. This review will examine the pathogenesis and treatment of dyslipidemias in patients with nephrotic syndrome, chronic renal failure and renal transplantation.

Humans↗
PubMed1998

In vitro effect of estradiol, progesterone, testosterone, and of combined estradiol/progestins on low density lipoprotein (LDL) oxidation in postmenopausal women.

OBJECTIVE: One of the mechanisms currently proposed to explain the cardioprotective effect of hormone replacement therapy (HRT) is the antioxidative property of estrogens. Considering that HRT involves the administration of an estrogen, usually combined with a progestin and sometimes with an androgen, we investigated the following in vitro: (1) the effect of estradiol, progesterone, and testosterone on the oxidation of low density lipoprotein; (2) the possible pro-oxidative effect of progesterone and testosterone on native low density lipoprotein; and (3) the possible modification of the antioxidant effect of estradiol on low density lipoprotein induced by progestins. DESIGN: Low density lipoprotein was isolated from blood samples obtained from 20 untreated postmenopausal women and divided in multiple aliquots, each containing 0.5 mg LDL protein. In Protocol 1 (n = 10) different doses of estradiol, progesterone, and testosterone ranging from 0 to 26 micrograms/ml were tested inducing oxidation with 15 microM copper sulfate. In Protocol 2 (n = 6) we studied the rate of oxidation of low density lipoprotein incubated with progesterone or testosterone without any oxidative induction. In Protocol 3 (n = 10) we studied the concomitant effect of 15 microM estradiol with four separate progestins (progesterone, medroxyprogesterone acetate, norethindrone, and norgestrel) in different doses (0, 5, 15, and 50 microM). After incubation for 4 h at 37 degrees C, malonaldehyde was measured as a marker of low density lipoprotein oxidation. The results were expressed in mean +/- SD. RESULTS: Protocol 1: Estradiol induced a dose-dependent decrease in malonaldehyde generation, from a baseline of 61.8 +/- 30.2 nmol/mg protein to 11.6 +/- 7.1 nmol/mg protein at the highest dose of estradiol tested (p < 0.0001). Progesterone or testosterone did not modify malonaldehyde generation. Protocol 2: Progesterone and testosterone did not show pro-oxidative action. Protocol 3: Estradiol 15 microM alone induced a 35% decrease in malonaldehyde generation, from a baseline of 75.4 +/- 25.4 to 49.3 +/- 18.8 nmol/mg protein (p < 0.0001). Norgestrel and norethindrone did not modify the antioxidant effect of estradiol (p > 0.05). Progesterone and medroxyprogesterone acetate induced a further reduction of malonaldehyde concentration to 37.2 +/- 20.8 and 38.6 +/- 18.2 nmol/mg protein, only at the highest dose tested (p < 0.02 and p < 0.01, respectively). CONCLUSIONS: Our results demonstrate that, in contrast with the potent antioxidant effect of estradiol, progesterone and testosterone did not show any pro- or antioxidant effect on low density lipoprotein in vitro. Furthermore, progestins did not counteract the antioxidant effect of estradiol in vitro.

Copper Sulfate↗
PubMed1998

[Comparison of the antioxidant effect of estriol and estradiol on low density lipoproteins in post-menopausal women].

BACKGROUND: Estradiol (E2) has a potent antioxidant effect on low density lipoproteins (LDL) in vitro and in vivo, which could be important in explaining the cardioprotective effect of hormone replacement therapy (HRT) in post menopausal women. Estriol (E3), on the other hand, is a weak estrogen with low metabolic effects on different tissues, and at present no cardioprotective effect has been attributed to this steroid. AIM: To study the antioxidant effect of E3 on LDL and to compare it with the potent antioxidant action exhibited by E2. SUBJECTS AND METHODS: After LDL was isolated by ultra centrifugation from plasma of 12 healthy untreated post menopausal women, it was divided into aliquots containing 0.5 mg of LDL protein. Estriol and E2 in doses of 0, 1, 5, 15 and 50 microM were incubated with different aliquots of LDL. CuSO4 15 microM was added to each aliquot to induce an oxidative stress. The aliquots were then incubated during 4 hours at 37 degrees C. Malonaldehyde (MDA) was measured as a marker of LDL oxidation, and expressed as nM/mg protein. RESULTS: (mean +/- SD): Estriol induced a dose-dependent decrease in MDA concentration (baseline 62.8 +/- 21.7; 1 microM: 61.5 +/- 23.0; 5 microM: 52.9 +/- 20.3; 15 microM 43.5 +/- 20.1 and 50 microM: 31.0 +/- 17.6 nM/mg protein; F = 92.4; p < 0.0001), reaching a mean decrease of 50.7% at the highest dose tested. Estradiol has a similar dose-dependent decrease in MDA concentration (F = 60.2; p < 0.0001), revealing a more potent effect than E3 (p < 0.05), with a mean decrease of 67.4% at the highest dose tested. CONCLUSIONS: Our results demonstrate that estriol shows an important antioxidant action of LDL in vitro, although its effect is less potent than estradiol. These results raise the possibility that estriol could have a cardioprotective effect in post menopausal women, possibility that has not been yet demonstrated.

Antioxidants↗
PubMed1997

[The problem of obesity and its shocking characteristics in Chile].

Obesity is a disease which severely affects health associated to an increase in relative mortality. The measurement of obesity is currently performed by means of the Body Mass Index (BMI). Normal BMI values are between 20 and 24.9 kg/m2. In obese individuals a central fat distribution is associated with an increased mortality in men and probably in women when compared with a peripheral distribution. Based on studies carried out in the Metropolitan Region (Greater Santiago) in 1992, it is estimated that the prevalence of obesity in the population is near 20% in men and 40% in women, with the highest prevalence being observed in women from a low socioeconomic level. The projection of these figures to the whole country gives an estimate of 2.5 million people in Chile with an increased risk of mortality due to obesity. Since there is a lack of awareness in the Chilean population of the pathology of obesity and its consequences, the implementation of programs of prevention and treatment of this disease lead by the health authorities is of paramount importance.

Body Mass Index↗
PubMed1997

[Diabetic neuropathy: thermal sensation and metabolic control in non-insulin-dependent diabetics].

BACKGROUND: The early detection of peripheral neuropathy in diabetics is important since it is the main risk factor for lower limb trophic lesions in diabetics. AIM: To assess the relationship between feet thermal sensation threshold and metabolic control in ambulatory non-insulin-dependent diabetics. PATIENTS AND METHODS: A random sample of 34 non-insulin-dependent diabetics followed for more than five years in a special clinic, out of 368 patients, was selected. Warmth sensation thresholds were measured in the dorsum of both feet using a MSTP-III thermostimulator. The average value of all glycosylated hemoglobins obtained during the 9.7 +/- 5.3 years of follow up for each patient was calculated. A multiple stepwise regression analysis was performed between thermal sensation as the dependent variable and glycosylated hemoglobin, fasting blood glucose, age and diabetes duration. RESULTS: The regression model disclosed glycosylated hemoglobin as the only independent predictor of warmth sensation threshold (partial r = 0.385; p = 0.043). Fifteen diabetic patients with good metabolic control, defined as those with a mean glycosylated hemoglobin of less than 9.5%, had a warmth sensation threshold of 35.6 +/- 3.7 degrees C, whereas 19 diabetics with a had control (glycosylated hemoglobin > or = 9.5%) had a threshold of 39 +/- 3.8 degrees C (p = 0.017). CONCLUSIONS: In this group of diabetics, there is a relationship between the severity of distal polyneuropathy and the metabolic control, assessed with glycosylated hemoglobin levels.

Aged↗
PubMed1995

[Indicators of atherosclerosis risk. Evaluation with coronary angiography in non diabetic men with total cholesterol levels equal to or below 240 mg/dl].

We studied 90 male non diabetic patients aged between 40 and 65 years old with a total cholesterol of less than 240 mg/dl and not receiving cholesterol reducing drugs, that were subjected to elective coronary arteriography. Weight, height, blood pressure and smoking habits were recorded and a fasting blood sample was drawn to measure total and HDL cholesterol, triglycerides, apoproteins A1 and B, Lipoprotein(a) and plasma cholesteryl ester transfer activity. Arteriography disclosed coronary lesions in 54 patients. Compared to patients without lesions, the former had lower HDL cholesterol (34 +/- 9.8 vs 40.2 +/- 11.6 mg/dl) and higher total cholesterol/HDL cholesterol and apoB/apoA1 ratios. No differences were found for lipoprotein(a) and plasma cholesteryl ester transfer activity. Univariate analysis showed that low HDL cholesterol had the best predictive capacity for atherosclerosis.

Adult↗
PubMed1995

[Immunologic and insulin secretion markers in non insulin dependent diabetic patients with secondary failure to oral hypoglycemic drugs].

BACKGROUND: The pathogenesis of secondary failure to hypoglycemic agents is heterogeneous. Some patients are true insulin dependent diabetics with a slow autoimmune disease suggested by their positive islet cell antibodies. Others, have an increased insulin resistance. AIM: To assess the frequency of positive islet cell antibodies in diabetic patients with secondary failure to oral hypoglycemic agents. PATIENTS AND METHODS: Thirty one diabetics, 16 with recent (less than six months) secondary failure and 15 with metabolically stable non insulin dependent diabetes were studied. All patients were older than 25 years old and had a body mass index of less than 30 kg/m2. C peptide levels before and at 5, 15 and 30 min after IV glucagon, islet cell antibodies using the Poly Human IgG peroxidase method and insulin sensitivity and secretion (estimated by the Homeostasis Model Assessment) were measured. RESULTS: Patients with secondary failure had lower C peptide levels, compared to subjects with stable diabetes (basal: 1.5 +/- 0.2 and 2.8 +/- 0.2 ng/ml; 5 min: 2.4 +/- 0.3 and 5.5 +/- 0.5 ng/ml; 15 min: 1.9 +/- 0.3 and 4.0 +/- 0.6 ng/ml; 30 min: 1.6 +/- 0.3 and 3.4 +/- 0.5 ng/ml). Beta cell activity was 20.6 +/- 4.3% in patients with secondary failure and 92.2 +/- 9% in stable diabetics (p < 0.01). Insulin sensitivity was similar in both groups (48.6 +/- 6 and 42.8 +/- 3.5% respectively). Three patients with secondary failure and none with stable diabetes had positive islet cell antibodies. When comparing patients with secondary failure and positive antibodies and subjects with secondary failure and negative antibodies, the former had non significantly lower age, BMI and C peptide levels. CONCLUSIONS: Some diabetic patients with secondary failure have positive islet cell antibodies. They should be measured in these patients to start insulin treatment precociously.

Administration, Oral↗
PubMed1994

[Is lipoprotein (a) a risk factor for coronary disease?].

The serum level of Lp(a) ha been defined in retrospective and cross sectional studies as an independent risk factor for acute myocardial infarction and cerebrovascular thrombotic accidents. However, recent prospective studies have found no evidences of association between Lp(a) levels and risk of myocardial infarction, therefore, current knowledge does not support the measurement of Lp(a) as a screening tool among middle age men. Further research is needed, to identify specific groups where Lp(a) may be a risk factor.

Adult↗
PubMed1993

[Non-insulin-dependent diabetics with secondary failure: insulin therapy at bedtime combined with glibenclamide].

Secondary failure and the requirement is common in patients with non-insulin dependent diabetes mellitus. The combination of sulfonylureas with NPH insulin at bedtime has been proposed to avoid high doses of insulin. We treated 18 patients (2 men, age range 47-76 yr) non respondent to diet and glibenclamide, combining NPH insulin in an average dose of 0.3 +/- 0.03 U/kg BW at bedtime for 6 months. Fasting serum glucose improved from 256 +/- 11 to 132 +/- 6 mg/dl and HbA1C from 13.6 +/- 0.4 to 9.9 +/- 0.2%. Four patients achieved a good control (defined as a HbA1C < 9), 9 a fair control (HbA1C 9.1-10) and 5 persisted with a bad control (HbA1C > 10). Well controlled patients were younger, had a shorter duration of diabetes and had a non significantly higher body mass index. Fasting serum insulin and C peptide levels achieved after glucagon injection were not predictors of the metabolic response to combined therapy. Tolerance to treatment was good, without changes in blood pressure or serum lipids and with a low incidence of hypoglycemia. There was a mean increase of 3.6 kg in body weight. After 6 months of therapy, maximum achieved C peptide values after glucagon increased from 3.3 +/- 0.3 to 4.5 +/- 0.4 ng/ml. It is concluded that combined glibenclamide and NPH insulin at bedtime is useful to treat secondary failure in non-insulin dependent diabetic patients, but their response in variable and non dependent on their beta insular secretion.

Aged↗
PubMed1993

[Dyslipidemic patients with coronary cardiopathy. Effect of different doses of OMEGA-3 fatty acids on serum lipids and lipoproteins].

Twenty one male patients aged 35 to 70 years, with coronary artery disease and dislipidemia refractory to dietary treatment, were assigned to three parallel groups of 7 individuals each that received a supplemental dose of 2, 4 and 6 g/day of omega-3 fatty acids during 60 days. After a 30 days wash-out period and 60 of supplementation, subjects were weighed, a dietary survey was performed, serum levels of total cholesterol and triglycerides, the lipid content of serum lipoproteins and the content of EPA+DHA in plasma phospholipids were measured. A dose dependent increase in EPA+DHA content of phospholipids and no changes in weight or nutrient intake were observed during the supplementation period. With the 6 g dose, a significant reduction in total cholesterol, with a reduction in VLDL and increase in LDL cholesterol and a decline in VLDL triglycerides was observed. With the 4 g dose a reduction in total cholesterol at the expense of VLDL and HDL cholesterol and a reduction in VLDL triglycerides but no changes in total triglycerides was observed. No changes in serum lipids were observed with 2 g dose. In patients with type IIA hyperlipidemia, a significant positive correlation was observed between DHA+EPA content of plasma phospholipids and LDL cholesterol, this correlation was not observed in patients with IIB or IV phenotypes. It is concluded that omega-3 fatty acids are ineffective as the only treatment for dislipidemias refractory to diet.

Adult↗
PubMed1992

[The effect of body weight change on cardiovascular risk factors].

Changes in cardiovascular risk factors and body weight were correlated in 568 professional males from 17 to 57 years of age. Measurements of weight, height, body mass index, blood pressure and fasting levels of blood sugar, triglycerides, total and HDL cholesterol were obtained in 1980 and again in 1985. A significant correlation was found between body mass index and blood pressure, total cholesterol, total/HDL cholesterol, HDL cholesterol (p < 0.005), triglycerides (p < 0.001) and blood sugar (p < 0.05). Changes in body weight during the study period were correlated to changes in total cholesterol (p < 0.001), triglycerides (p < 0.05) and diastolic blood pressure (p < 0.005). Thus, obesity is correlated to the presence of cardiovascular risk factors. Its modification may influence development of atherosclerotic cardiovascular disease.

Adolescent↗
PubMed1992

[Effect of dietary polyunsaturated fatty acids on the content and metabolism of glutathione in rat kidney].

The effect of dietary polyunsaturated fatty acids (PIFA) upon the content of reduced glutathione (GSH) of the kidney was studied in 32 male Wistar rats. Two equal size groups were fed diets supplemented with either 10% or 18% corn oil. Sixteen hours before death, half of each experimental group was submitted to fasting. The content of GSH and the activity of gamma glutamyl transpeptidase (GGTP) and gamma glutamyl cysteine synthetase was determined in kidney tissue. Fasting led to a reduction of GSH from 3.21 +/- 0.54 to 1.25 +/- 0.20 mumol per gm in the group fed 10%. PIFA. Equivalent figures for the group fed 18% PIFA were 3.49 +/- 0.54 and 0.49 +/- 0.08, respectively. GGTP activity increased significantly after fasting but no differences were observed according to level of PIFA intake. The exaggerated reduction of GSH during fasting after a high PIFA intake may expose the animals to risk of cell damage induced by peroxides or other oxidating agents.

Animals↗