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Biomedical subjects

M L Santos

Publications and source records attributed to M L Santos.

At least 19 recordsLinked to original sources
PubMed2004

Effects of interferon and ribavirin combination therapy on CD4+ proliferation, lymphocyte activation, and Th1 and Th2 cytokine profiles in chronic hepatitis C.

We studied the relationship between immunological markers such as CD4+ proliferation, cytokines profile and lymphocyte activation markers in patients with chronic hepatitis C, having different responses to interferon (IFN) and ribavirin (RBV) treatment. A prospective study of 20 patients was conducted, six had received IFN-alpha-2b alone and 14 IFN in combination with RBV. The proliferative immune responses of peripheral blood mononuclear cells to hepatitis C virus peptides and the lymphocyte activation markers (CD25+, CD38+ and CD69+) were assessed before treatment, at 1 week, and 1, 3 and 6 months of treatment. Cytokines interleukin (IL)-2, IFN-gamma, IL-4 and IL-10 were determined in supernatants before onset of treatment and at 1 and 6 months thereafter. Stimulation indices (SI) were higher in the sustained responders (SR), in comparison with those with no response (NR), before treatment (5.2 +/- 3.7 to 3.3 +/- 1.9, P = 0.028) and also at 6 months (7.8 +/- 1.9 to 4.1 +/- 1.2, P = 0.021). Patients with SR also had high SI to NS3 when compared with those with transitory response or no response (NR) (4.9 +/- 2.5 and 3.3 +/- 1.1, P = 0.033). At 1 month, SR had higher supernatant IL-2 than those with NR (133.8 +/- 119.2 to 56.0 +/- 89.3 pg/mL, P = 0.023) and lower levels of IL-10 (13.8 +/- 10.1 and 167.1 +/- 272.0 pg/mL, P = 0.023) in response to NS3. Combination therapy induced a higher percentage of the lymphocyte activation markers CD69+ and CD38+. In conclusion, we found that SR is associated with higher CD4+ proliferation particularly in response to the NS3 region, promoting a T-helper (Th)1/Th0 profile of cytokines, and that combination therapy induced a higher percentage of lymphocyte activation than therapy with IFN alone.

Adult↗
PubMed2003

Insulin secretion, insulin sensitivity, and hepatic insulin extraction in first-degree relatives of type 2 diabetic patients.

To identify early metabolic abnormalities in type 2 diabetes mellitus, we measured insulin secretion, sensitivity to insulin, and hepatic insulin extraction in 48 healthy normal glucose-tolerant Brazilians, first-degree relatives of type 2 diabetic patients (FH+). Each individual was matched for sex, age, weight, and body fat distribution with a person without history of type 2 diabetes (FH-). Both groups were submitted to a hyperglycemic clamp procedure (180 mg/dl). Insulin release was evaluated in its two phases. The first was calculated as the sum of plasma insulin at 2.5, 5.0, 7.5, and 10.0 min after the beginning of glucose infusion, and the second as the mean plasma insulin level in the third hour of the clamp procedure. Insulin sensitivity index (ISI) was the mean glucose infusion rate in the third hour of the clamp experiment divided by the mean plasma insulin concentration during the same period of time. Hepatic insulin extraction was determined under fasting conditions and in the third hour of the clamp procedure as the ratio between C-peptide and plasma insulin levels. FH+ individuals did not differ from FH- individuals in terms of the following parameters [median (range)]: a) first-phase insulin secretion, 174 (116-221) vs 207 (108-277) microU/ml, b) second-phase insulin secretion, 64 (41-86) vs 53 (37-83) microU/ml, and c) ISI, 14.8 (9.0-20.8) vs 16.8 (9.0-27.0) mg kg-1 min-1/ microU ml-1. Hepatic insulin extraction in FH+ subjects was similar to that of FH- ones at basal conditions (median, 0.27 vs 0.27 ng/microU) and during glucose infusion (0.15 vs 0.15 ng/ micro U). Normal glucose-tolerant Brazilian FH+ individuals well-matched with FH- ones did not show defects of insulin secretion, insulin sensitivity, or hepatic insulin extraction as tested by hyperglycemic clamp procedures.

Adult↗
PubMed2002

Ventilation with high tidal volume induces inflammatory lung injury.

Mechanical ventilation with high tidal volumes (V(T)) has been shown to induce lung injury. We examined the hypothesis that this procedure induces lung injury with inflammatory features. Anesthetized male Wistar rats were randomized into three groups: group 1 (N = 12): V(T) = 7 ml/kg, respiratory rate (RR) = 50 breaths/min; group 2 (N = 10): V(T) = 21 ml/kg, RR = 16 breaths/min; group 3 (N = 11): V(T) = 42 ml/kg, RR = 8 breaths/min. The animals were ventilated with fraction of inspired oxygen of 1 and positive end-expiratory pressure of 2 cmH2O. After 4 h of ventilation, group 3, compared to groups 1 and 2, had lower PaO2 [280 (range 73-458) vs 517 (range 307-596), and 547 mmHg (range 330-662), respectively, P<0.05], higher wet lung weight [3.62 +/- 0.91 vs 1.69 +/- 0.48 and 1.44 +/- 0.20 g, respectively, P<0.05], and higher wet lung weight/dry lung weight ratio [18.14 (range 11.55-26.31) vs 7.80 (range 4.79-12.18), and 6.34 (range 5.92-7.04), respectively, P<0.05]. Total cell and neutrophil counts were higher in group 3 compared to groups 1 and 2 (P<0.05), as were baseline TNF-alpha concentrations [134 (range <10-386) vs 16 (range <10-24), and 17 pg/ml (range <10-23), respectively, P<0.05]. Serum TNF-alpha concentrations reached a higher level in group 3, but without statistical significance. These results suggest that mechanical ventilation with high V T induces lung injury with inflammatory characteristics. This ventilatory strategy can affect the release of TNF-alpha in the lungs and can reach the systemic circulation, a finding that may have relevance for the development of a systemic inflammatory response.

Animals↗
PubMed2002

Brazilian individuals with impaired glucose tolerance are characterized by impaired insulin secretion.

BACKGROUND: To better understand the pathogenesis of type 2 diabetes mellitus, insulin secretion and insulin sensitivity (IS) were evaluated in white Brazilians with impaired glucose tolerance (IGT), using the oral glucose tolerance test (OGTT) and the hyperglycemic clamp technique. METHODS: Twenty-five IGT subjects were individually matched with normal glucose-tolerant (NGT) subjects for demographic characteristics. At first, they were submitted to the OGTT and plasma glucose and insulin were measured. Of the 25 pairs, 20 could participate in the hyperglycemic clamp procedures, at a second visit. All participants had their plasma glucose levels equally increased to 180 mg/dl; this was maintained for three hours by variable glucose infusion. During the procedure, plasma glucose and insulin were measured at established intervals. RESULTS: In the postabsorptive state, the IGT subjects presented higher levels of plasma glucose, blood HbA1, and serum triglycerides, but similar plasma insulin levels. After the oral glucose load, early and total insulin release, in relation to glucose levels, were respectively, 43 and 67% lower in the IGT individuals. The index of whole-body IS was increased in the IGT individuals (4.36 +/- 1.71 vs 3.61 +/- 1.28 mg(-1). micro U(-1).100.ml2; p<0.05). By the hyperglycemic clamp technique first- (82 +/- 26 vs 215 +/- 88 micro U/ml; p<0.001) and second- (36 +/- 19 vs 73 +/- 44 micro U/ml; p<0.05) phases of insulin secretion was decreased in the IGT individuals, especially the first one. However, the groups did not differ in relation to the IS: IGT=13.52 +/- 7.27 and NGT=9.96 +/- 6.70 mg.ml/kg. micro U.min(-1); p > 0.05. Functional relationship of IS (y) on first-phase insulin release (x) showed a smaller (p<0.05) regression coefficient for the IGT group. CONCLUSION: Brazilians with IGT well-matched with NGT ones were characterized by impaired first- and second-phase insulin secretion (mainly the former), while defects in IS were not evident.

Adult↗
PubMed2001

[Magnetic resonance angiography of intracranial aneurysms: comparative study with cerebral angiography].

We studied by magnetic resonance angiography and cerebral angiography 41 patients with 55 aneurysms confirmed by surgery. The MR angio detected 52 aneurysms with sensibility of 94.5% and the cerebral angiography detected 53 aneurysms with sensibility of 96.3%. For being non invasive, more quickly and less expensive MR angio may substitute vascular angiography in the diagnosis of intracranial aneurysms and prognosis of the subarachnoid hemorrhage

Adult↗
PubMed2000

Increased exhalation of hydrogen peroxide in healthy subjects following cigarette consumption.

CONTEXT: Increased hydrogen peroxide has been described in the expired breath condensate (H2O2-E) of several lung conditions, such as acute respiratory distress syndrome, chronic obstructive pulmonary disease and asthma. This technique has been advocated as being a simple method for documenting airway inflammation. OBJECTIVE: To evaluate H2O2-E in healthy cigarette smokers, and to determine the acute effects of the consumption of one cigarette on H2O2-E levels. TYPE OF STUDY: Prospective, controlled trial. SETTING: A pulmonary function laboratory in a University Hospital. PARTICIPANTS: Two groups of healthy volunteers: individuals who had never smoked (NS; n=10; 4 men; age = 30.6 +/- 6.2 years) and current cigarette smokers (S; n=12; 7 men; age = 38.7 +/- 9.8). None of the volunteers had respiratory symptoms and all showed normal spirometric tests. INTERVENTION: Expired air was collected from all volunteers through a face mask and a plastic collecting system leading into a flask with dry ice and pure ethanol. Samples from the group S were collected twice, before and half an hour after the combustion of one cigarette. MAIN MEASUREMENTS: Expired hydrogen peroxide using the Gallati and Pracht method. RESULTS: The S and NS groups showed comparable levels of H2O2-E at basal conditions [NS = 0.74 microM (DP 0.24) vs. S = 0.75 microM (DP 0.31)]. The smokers showed a significant increase in H2O2-E levels half an hour after the consumption of only one cigarette [0.75 microM (DP 0.31) vs. 0. 95 microM (DP 0.22)]. CONCLUSION: The present results are consistent with the concept that smokers increase oxidative stress with elevated production of reactive oxygen species, contributing to the development of smoking-related disorders.

Adult↗
PubMed1996

Influences on meat avoidance among British students.

Male and female undergraduates (18-23 years old; 68% in their first year; N = 158) who had just chosen a vegetarian dish in a campus dining hall or restaurant reported a diversity of meat avoidance habits before arrival at University a few weeks previously. More women than men had avoided meat and other flesh foods, with the exception of fish. Consistently with the distinction between "red" and "white" meats, chicken and turkey were the least often avoided flesh foods among men and women. The only clear gradation from flesh-eating to vegetarianism was eating poultry and either beef/lamb or pork, eating only poultry and eating neither; fish was not on this Guttman scale, contrary to previous assumptions. Reasons for avoiding meat and perceived influences on preferences for food in their chosen vegetarian dish were elicited by open-ended interviews in 41 women from the meat-avoidance survey. Rationales spontaneously offered were as diverse as reported in previous studies, but always included at least two of the following: ethics of raising/killing animals, concern for health, sensory factors, disgust and influence of friends. In contrast, choices among described variants of the familiar dish were largely controlled by its sensory and nutritional features, presumably because other attributes had been factored out.

Adolescent↗
PubMed1994

[Validity of 6 indirect methods to assess treatment compliance in arterial hypertension].

BACKGROUND: For adequate control of high blood pressure (HBP) the therapy indicated must be correct, with effective medication which must be taken as required. At a collective level methods to evaluate patients' compliance of the above are necessary since without the same the efficacy of the drugs cannot be determined. In this study methods allowing the clinic to easily quantify patient fulfillment were sought. METHODS: Six indirect methods were used to evaluate therapeutic compliance: 1) self communicated compliance (SC), 2) appointment attendance (AA), 3) degree el control obtained in the blood pressure (DC), 4) Morinsky and Green tests (M-G), 5) patient's knowledge of the disease (PK) and 6) doctor's judgement on patient's compliance (DJ). All the above were applied to 152 hypertense patients randomly selected from the Health Centers of Alfaz and Alicante (Spain). Concordance with the compliance obtained from the "counting of tablets" in the patient's home and by surprise were evaluated by double entry tables. RESULTS: The SC is the method which obtains greatest specificity (96.7%), exactness (73%), probability of low compliance (88%) and percent of probability of low compliance (11.3%). The PK had greatest sensitivity (83.3%) and greater probability of high compliance (83.6%) and percentage of probability of high compliance (0.3%). The SC (23.1%), AA (1.3%) and the DJ (7.5%), overestimate good compliance. The M-G test (7.9%) and the PK (20.4%) overestimate had compliance. CONCLUSIONS: In this study self communicated compliance and patient's knowledge of disease were the methods which provided the best indicators of validity to measure therapeutic compliance in high blood pressure in outpatients, although there is the inconvenience of significantly over and under estimating good and bad compliance.

Evaluation Studies as Topic↗
PubMed1994

[Community reintegration of long-course psychiatric patients. Development of a residential structure].

Segregation from the community of long-term psychiatric patients leads to an increase in psychiatric disability. The rehabilitation process envisages the development of autonomy and personal realization and must be linked to a continuity of rendered care. In the resettlement of these patients there are priority needs to fulfill along with housing. Scarceness of community resources, in our country including accommodation facilities, led us to a project aimed at creating a residential unit within a pilot experiment. Essential points are focused, namely unit definition, staff formation, patient selection and training, community resources survey, financing and efficacy indicators. In conclusion, possible errors to avoid in the conception of a unit such as the one described are pointed out.

Community Mental Health Centers↗
PubMed1992

Isolation of Trypanosoma cruzi from blood by histopaque and continuous percoll gradient centrifugations.

Separation of the blood forms of trypanosomes from the blood of infected animals is difficult, especially in the case of Trypanosoma cruzi Y strain. Two procedures to isolate the Y strain blood forms of T. cruzi using polyvinyl pyrrolidone-coated silica (percoll) and histopaque are reported in this study. The recovery rates of parasites were 16 +/- 5 and 68 +/- 16%, respectively. The parasites isolated by these methods presented normal motility and morphology and were infective to albino mice with prepatent periods, parasitemia curves, and polymorphism patterns during the infection that were similar to those of control parasites. In addition, the preservation of surface antigens was confirmed by immunocytochemical studies.

Animals↗
PubMed1992

Leishmania amazonensis infection: a comparison of in vivo leishmanicidal mechanisms between immunized and naive infected BALB/c mice.

In vitro studies have shown that both macrophage activation and destruction of parasitized macrophages lead to leishmania destruction. The relative role played by such mechanisms in vivo have not been properly evaluated. We took advantage of the model of intravenous immunization with solubilized leishmanial antigen which renders partially resistant the otherwise highly susceptible BALB/c mice to address this issue avoiding the interference of different genetic backgrounds. Leishmania destruction occurred in three situations: destruction of the parasitized macrophage, which were in close contact with lymphocytes or eosinophils; extracellular damage, always surrounded by small foci of granulocytes; and parasite damage inside activated macrophages. Destruction of the parasitized macrophages was frequently seen in immunized and protected animals. Our observations suggest that destruction of parasite-loaded macrophages is an important mechanism of host protection in experimental cutaneous leishmaniasis.

Animals↗
PubMed1992

[Bernard-Soulier syndrome and pregnancy: a case report].

This is the fifth case of the Bernard-Soulier syndrome to be described in the literature. The ante-natal period, the delivery and post-partum course without any complications. The platelet concentrations were used ante-natally and after delivery.

Adult↗
PubMed1991

Granulocytes in the inflammatory process of BALB/c mice infected by Leishmania amazonensis. A quantitative approach.

We used previously immunized (partially resistant) and naive (highly susceptible) BALB/c mice infected with Leishmania amazonensis for evaluating the role of granulocytes in the course of murine leishmaniasis. The animals were examined at different times post-infection and granulocytes counted in lesion tissues examined ultra-structurally. Polymorphonuclear granulocytes predominated during the early phase of infection and their number decreased with progression of infection; their number was similar in both groups during the early and intermediate phases of infection, though slightly higher in immunized animals during the late phase. Eosinophils represented approximately 10% of cells in the inflammatory infiltrate, being higher during the intermediate phase, and not differing between the groups. Another approach was the evaluation of granulocyte migration to the peritoneal cavity of susceptible BALB/c mice or resistant C57BL/6 mice under several stimuli. There was no statistically significant difference between resistant and susceptible animals in any of the treatments. Despite the influx of granulocytes to the lesion and its possible role in the initial destruction of injected Leishmania, this aspect does not seem to have an important effect on the outcome of the leishmanial infection.

Animals↗
PubMed1988

Influence of sublingual captopril on plasma catecholamine levels during hypertensive emergencies and cold immersion.

Experimental evidence of captopril-induced inhibition of sympathetic activity, mediated by decrease in angiotensin II production, is presented. The blood pressure, plasma catecholamine, plasma renin activity, and plasma aldosterone responses to a single dose of sublingual captopril in 23 patients with hypertensive emergencies were evaluated. The major correlation found was between the captopril-induced decrease in blood pressure and the decrease in plasma norepinephrine levels (r = 0.57, p less than 0.01). In another 11 hypertensive patients with normal or high renin levels, captopril lowered by 65 percent the increase in plasma norepinephrine induced by cold immersion of the forearm. In both circumstances, plasma renin and aldosterone levels changed in accordance with the expected inhibition of angiotensin converting enzyme activity. These data suggest that, in selected circumstances in hypertensive patients, captopril exhibits a depressive influence on sympathetic activity along with the inhibition of the renin-angiotensin system.

Administration, Sublingual↗
PubMed1986

Antithyroid antibodies as an early marker for thyroid disease induced by amiodarone.

Changes in thyroid function may occur during treatment with amiodarone. A double blind prospective trial of amiodarone and placebo was performed in 37 patients in the subacute phase of myocardial infarction. Though none of the patients assigned to receive placebo developed any antibody, six of 13 patients treated with amiodarone developed antithyroid microsomal antibodies. There was no difference in triiodothyronine and thyroxine concentrations between the two groups, but a significant difference in concentrations of thyroid stimulating hormone was noted on day 30 (p less than 0.05). Six months after the withdrawal of amiodarone autoantibodies could not be detected and concentrations of thyroid stimulating hormone were normal. These antibodies have not previously been reported to develop during short term treatment with amiodarone. They could have an important role in the detection of early thyroid changes in patients given amiodarone.

Adult↗