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Biomedical subjects

J Ballesteros

Publications and source records attributed to J Ballesteros.

At least 37 records · Page 2Linked to original sources
PubMed2000

Tardive dyskinesia associated with higher mortality in psychiatric patients: results of a meta-analysis of seven independent studies.

This article reports a meta-analysis of seven independent studies on the association of tardive dyskinesia with all-cause mortality in psychiatric patients. Most of the studies included provide either small sample sizes or follow-up periods too short to reach a substantive conclusion on their own. In the meta-analysis, the overall odds ratio (OR) was significant when calculated either by the fixed-effects model (OR = 1.4, 95% confidence interval [CI] = 1.2-1.7, p < 0.005) or the random-effects model (OR = 1.4, 95% CI = 1.1-1.8, p < 0.005). There was no overall heterogeneity (Q test = 8.1, df = 7,p = 0.32). The overall estimate changed within study designs (OR = 1.4,p = 0.002 in three prospective controlled studies; OR = 2.2, p = 0.02 in two prospective uncontrolled studies; and OR = 0.9, p = 0.80 in two retrospective controlled studies). It was modified upward when the two most influential studies (one prospective and one retrospective) were removed from the overview (OR = 2.2, 95% CI = 1.4-3.5,p = 0.001; Q test = 0.81, df = 4,p = 0.94). The conclusion of the meta-analysis was that tardive dyskinesia must be considered a weak risk factor in terms of mortality. It remains to be elucidated whether it is a risk factor on its own or just a surrogate for any unknown organic liability.

Antipsychotic Agents↗
PubMed1998

Functional microdomains in G-protein-coupled receptors. The conserved arginine-cage motif in the gonadotropin-releasing hormone receptor.

An Arg present in the third transmembrane domain of all rhodopsin-like G-protein-coupled receptors is required for efficient signal transduction. Mutation of this Arg in the gonadotropin-releasing hormone receptor to Gln, His, or Lys abolished or severely impaired agonist-stimulated inositol phosphate generation, consistent with Arg having a role in receptor activation. To investigate the contribution of the surrounding structural domain in the actions of the conserved Arg, an integrated microdomain modeling and mutagenesis approach has been utilized. Two conserved residues that constrain the Arg side chain to a limited number of conformations have been identified. In the inactive wild-type receptor, the Arg side chain is proposed to form an ionic interaction with Asp3.49(138). Experimental results for the Asp3. 49(138) --> Asn mutant receptor show a modestly enhanced receptor efficiency, consistent with the hypothesis that weakening the Asp3. 49(138)-Arg3.50(139) interaction by protonation of the Asp or by the mutation to Asn favors activation. With activation, the Asp3. 49(138)-Arg3.50(139) ionic bond would break, and the unrestrained Arg would be prevented from orienting itself toward the water phase by a steric clash with Ile3.54(143). The mutation Ile3.54(143) --> Ala, which eliminates this clash in simulations, causes a marked reduction in measured receptor signaling efficiency, implying that solvation of Arg3.50(139) prevents it from functioning in the activation of the receptor. These data are consistent with residues Asp3.49(138) and Ile3.54(143) forming a structural motif, which helps position Arg in its appropriate inactive and active receptor conformations.

Amino Acid Sequence↗
PubMed1998

First episode in bipolar disorder: misdiagnosis and psychotic symptoms.

BACKGROUND: This study explores factors that can influence other psychotic diagnoses in the first episode of a DSM-III-R bipolar disorder. METHODS: It includes all 163 bipolar in-patients and out-patients in the state of Alava, North of Spain (Basque country) from February 1994 to May 1996. Patients were divided into two non-overlapping groups: unstable diagnoses, bipolars with an initial diagnosis of schizophrenia (or other psychosis), and stable diagnoses of bipolar disorder. RESULTS: A logistic regression analysis using marital status, age at onset and mood incongruent psychotic symptoms found that the latter was the only independent factor significantly associated with an unstable diagnosis.

Adult↗
PubMed1997

The density of monoamine oxidase B sites is not altered in the postmortem brain of alcoholics.

The status of the enzyme monoamine oxidase B (MAO-B) was directly evaluated in the postmortem brain from 20 alcoholics and 23 matched controls. The density of MAO-B sites was quantified by the specific binding of the selective inhibitor [3H]Ro 19-6327 (lazabemide) (8 nM) to cortical membranes. A positive correlation between age at death and MAO-B density was observed in the total sample (r = 0.37, p = 0.015). The density of MAO-B in alcoholics (Bmax = 1,263 +/- 131 fmol/mg of protein) was not different form that in control (Bmax = 1,131 +/- 96 fmol/mg of protein). Ethanol in vitro inhibited [3H]Ro 19-6327 binding, with similar potency in membranes form alcoholics (Ki = 280 +/- 13 mM) and controls (Ki = 338 +/- 84 mM). The present results in brain tissue contrast with previous reports of decreased MAO-B enzymatic activity in platelets of alcoholics, but strongly agree with recent genetic studies on MAO-B status in alcoholism.

Adult↗
PubMed1996

[Use of alcoholism psychiatric services during an 18-month follow-up of alcoholic men].

BACKGROUND: The paper assesses the use of public psychiatric services by alcoholic patients for a period of 18 months, and looks for possible sociodemographic and clinical variables associated with higher use of services. MATERIAL AND METHODS: A prospective study of a cohort of male alcoholics (n = 137) from Alava (Spain). Information was gathered at the beginning of a treatment episode using a structured interview on sociodemographic and clinical variables, including Michigan Alcoholism Screening Test (MAST), and General Health Questionnaire (GHQ-60). At 18 month follow-up, clinical records were used to examine psychiatric inpatient and outpatient use in Alava (Spain). A service use score was set up to measure global use of services. RESULTS: Eighty-three percent of alcoholics used outpatient services at least once, 48% attended the day-care service at least once, and 24% were admitted in a psychiatric unit at least once, during 18 month follow-up. Twenty percent of patients used 80% of services. The logistic regression models point to the age, civil status, alcohol consumption amount and previous history of alcoholic treatments as the main predictors for heavy use of psychiatric services. CONCLUSIONS: A small percentage of alcoholics in treatment use the main part of psychiatric resources.

Adolescent↗
PubMed1996

Are homosexual males a risk group for hepatitis A infection in intermediate endemicity areas?

The purpose of this study was to examine the prevalence of antibody against hepatitis A (anti-HAV) in a population of homosexual men compared with that of heterosexual men in an area of intermediate HAV endemicity (Madrid, Spain). A total of 148 patients were recruited in a Sexually Transmitted Diseases Clinic: 74 homosexuals (mean age of 28 +/- 5 years) and 74 heterosexuals (29 +/- 5 years). The prevalence of anti-HAV antibody was 47% and 43% for homo- and heterosexuals, respectively. Among the factors evaluated (age, sexual orientation and practices, travel to high HAV endemicity areas) oral-anal contact was significantly associated with a higher prevalence of anti-HAV antibody (odds ratio, 2.8; 95% confidence interval, 1.1-7.4; P = 0.03). These results indicated that in an area of intermediate endemicity young homosexual men are not at increased risk of having acquired hepatitis A infection than heterosexuals. Oral-anal contact is an independent risk factor that influences the presence of anti-HAV antibody, regardless of sexual orientation.

Adult↗
PubMed1995

[Influence of the intravenous nitroglycerin dose on the appearance of drug tolerance].

BACKGROUND: There are few studies on the influence of different doses of intravenous nitroglycerin (NTG) on the appearance of drug tolerance. METHODS: A controlled clinical trial was performed in 40 patients admitted to an ICU with the diagnosis of acute myocardial infarction (AMI). The patients were divided into two groups: group A with a continuous perfusion of NTG at 2 mg/h, and group B with 4 mg/h. At 30 minutes of the infusion, NTG was exchanged for a placebo in half of the patients of each group (subgroups A1 and B1) with the remaining patients continuing with NTG for 24 h (A2 and B2). The hemodynamic variables studied were central venous pressure (CVP), pulmonary capillary pressure (PCP), mean pulmonary artery pressure (PAP) and mean blood pressure (BP). RESULTS: The patients in group A showed a decrease in the hemodynamic effects in all the variables studied. At 24 h of infusion no differences were observed with respect to the previous NTG values for CVP and PCP, with significant differences being maintained for PAP and BP. In group B the hemodynamic effect was maintained for all the variables during the 24 hours studied. CONCLUSIONS: In patients with acute myocardial infarction, the dosis of nitroglycerin administered was found to have a determined influence in the appearance of drug tolerance with this fact being more evident on evaluation of the effect of nitroglycerin on the venous system.

Aged↗
PubMed1995

Compliance with immunization against hepatitis B. A pragmatic study in sexually transmitted disease clinics.

The efficacy of a vaccine is based primarily on the adherence of the subject to the immunization schedule. This paper compares the compliance rates (CR) for the third dose of hepatitis B virus (HBV) vaccine given according to one of two vaccination schedules among subjects attending two sexually transmitted disease (STD) clinics, and the potential influence of place of vaccine administration (STD clinic or at a vaccination centre). Heterosexual, anti-HBc seronegative subjects (n = 331) were randomized to a 0-1-6 month (n = 161) or a 0-1-2-12 month schedule (n = 170) in this prospective, randomized, parallel pragmatic study. Some subjects (n = 50) attended and were vaccinated at one STD clinic (centre A), whereas 281 attended another clinic (centre B) but were referred to a vaccination centre for administration of vaccine. About 31% (103/331) of the subjects received at least three vaccine doses. On assessing the CR at the 3rd dose in all randomized subjects, we observed that administration of the vaccine at the STD clinic attended (A) was associated with a significantly better CR (p < 0.01) than that of the subjects referred to a vaccination centre (B), while the CR is not affected by the schedule. On the other hand, the 0-1-2-12 schedule was associated with a significantly better CR (p = 0.02) at the 3rd dose than the 0-1-6 month schedule among subjects who comply with the first two doses; the actual site of vaccine administration (in situ (A) versus referred (B)) does not affect the CR.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Factors associated with utilization of hospital emergency services by alcoholic patients in a follow-up study of 18 months].

BACKGROUND: This paper assesses the use of hospital emergency services by alcoholics in clinical treatment for a period of 18 months and looks for possible sociodemographic and clinical explanatory variables associated with use of those services. METHODS: A prospective study of a cohort of male alcoholics (n = 137) which began medical treatment because their alcoholism in outpatient or inpatient facilities. Information was assembled by means of a structured interview on sociodemographic and clinical variables, including the Michigan Alcoholism Screening Test (MAST) and the General Health Questionnaire (GHQ-60). RESULTS: Sixty-five percent of alcoholics (n = 88) attended the emergency services at least once during the 18 months of follow-up, and 25% (n = 34) did use them more than three times. The politomous logistic regression models point to the age (OR = 0.95; 95% CI = 0.92-0.98); MAST score (OR = 1.1; 95% CI = 1.0-1.2); and employment status (unemployed vs. employed, OR = 2.1; 95% CI = 1.0-4.4) as the main predictors for heavy attendance of emergency service. CONCLUSIONS: The relevance in this study of age, employment status, and alcohol-related problems experienced (MAST), as well as taking into account that 36% of attended emergencies were because drunkenness or demanding disintoxication treatment, point to the non-sanitary problems which emergency services might be looking after, at least for some alcoholics whom do not seem to adhere to regular treatment programs.

Adult↗
PubMed1992

Acute Chagas' disease (Trypanosomiasis americana) in acquired immunodeficiency syndrome: report of two cases.

Two heterosexual men, aged 31 and 40 years, with the acquired immunodeficiency syndrome and presenting with the acute form of Chagas' disease are reported. The first patient, a carrier of hemophilia A, was treated for 20 years with Chilean and Brazilian cryoprecipitates. This patient acquired both diseases through this medium. The second patient, an inhabitant of northern Chile (fourth region), was allegedly bitten by Triatoma infestans and was an intravenous drug addict. The hemophilic patient presented with a neurologic syndrome; a brain biopsy showed a necrotizing encephalitis with an obliterative angiitis and abundant macrophages. The second patient developed intractable congestive heart failure; necropsy showed a dilated myocarditis with rupture of myofibers and an inflammatory infiltrate rich in plasma cells, lymphocytes, and macrophages. Using light and electron microscopy, abundant amastigotes of Trypanosoma cruzi were seen in brain tissue, especially in the cytoplasm of macrophages, as well as in some myocardial fibers. In both cases, determination of anti-T cruzi antibodies (indirect hemagglutination technique) and xenodiagnosis were positive.

Acquired Immunodeficiency Syndrome↗
PubMed1992

[Factors associated with the failure to use condoms among a population of parenteral drug addicts].

Use of condom in sexual intercourse by intravenous drug users has been assessed among a clinical population (n = 139). The multiple logistic regression results show that being a female (OR = 5.1, 95% CI = 2.0-13.2), on drug dependence for a 5-year period or more (OR = 3.0; 95% CI = 1.3-6.9) correlates with non-condom use. Less than 25% of females use condom in their sexual contacts. On the contrary a higher educational level seems to protect subjects against non-condom use (R = 0.3; 95% CI = 0.1-0.8). The most parsimonious model fitting to data at hand includes such variables as sex, educational level, partnership and frequency of sexual intercourse, as well as years on addiction. Other set of variables such as living and working status, age, and previous sexually-transmitted diseases experience are not required for the final model. Emphasis is placed on the need for developing programs aimed at modifying the high risk behavior intravenous drug users resort to in their sexual intercourse, stressing that the main dissemination cause of the human immunodeficiency virus among such a population is due to their sharing drug injections equipment.

Adult↗
PubMed1992

[Chagas disease with the acquired immunodeficiency syndrome. Clinical cases].

We report 2 patients with AIDS who developed Chagas infection, one with encephalitis, the other with acute myocarditis. The implications of immune depression for the manifestations and course of Chagas disease are discussed. Chagas disease should be considered in patients with AIDS who live in endemic zones and who develop cerebral or cardiac manifestations.

Acquired Immunodeficiency Syndrome↗
PubMed1989

[Gentamicin and amikacin nephrotoxicity: comparative study in patients with initially normal renal function].

The purpose of this study was to compare the nephrotoxic potential of amikacin (AK) and gentamicin (GM) in patients (pts) with normal renal function at the beginning of the treatment (Tx) in an open comparative and prospective trial. Nephrotoxicity (NFTX) was defined as a blood creatinine (Cr) increase of at least 50% from the basal (normal) level, or an increase to higher than normal level during, at the end or after Tx. Peak and trough blood GM and AK levels were determined at 72 h of Tx to make proper adjustments in dosing. The two groups (GM, n = 27 and AK, n = 38) were similar in population composition, underlying pathology and infectious process requiring antimicrobials. Patients in the GM group tended to be older (mean age, 56 years) than the AK (mean age, 48 years) p NS; the latter had received more frequently aminoglycoside Tx (69 vs 11%) p less than 0.0005. The GM group received a comparatively lower dose than the AK (x = 2.87 mg/k/d and 16 mg/k/d respectively) but duration of Tx was similar. Fifteen of 27 pts receiving GM (56%) and 7 of 38 receiving AK (18.2%) developed NFTX, p less than 0.004. Five pts in the GM group (18.5%) and 2 in the AK (5.2%) had clinical NFTX. The difference in NFTX persisted after age adjustment. There were no intra or inter group significant differences between pts with or without NFTX. In conclusion, in pts with initial normal renal function gentamicin was significantly more nephrotoxic than amikacin.

Adult↗
PubMed1988

Teres minor. Source of symptoms resembling ulnar neuropathy or C8 radiculopathy.

Numbness and tingling in the ring and little fingers (fourth and fifth digits) is usually associated with a radiculopathy (C8) or compromise of a peripheral nerve (ulnar). The presence of a trigger point in the teres minor muscle may produce similar symptoms. Early diagnosis and appropriate treatment will save the patient unnecessary discomfort and reduce the use of sophisticated diagnostic testing.

Adult↗