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Biomedical subjects

A Vega

Publications and source records attributed to A Vega.

At least 55 records · Page 3Linked to original sources
PubMed1998

[Treatment of embolic cerebral infarct via thrombolysis and cytoprotection with U-74389-G in rats].

INTRODUCTION: The best treatment for cerebral ischemic will probably comprise the association of inhibition of ischemia-reperfusion injury mediators and early reperfusion. OBJECTIVE: We tried to demonstrate if reperfusion by thrombolysis (rt-PA) and free radical scavenging (U-74389-G) reduces ischemic-reperfusion cerebral injury in a rat model of embolic brain infarction. MATERIAL AND METHODS: 39 female Long Evans rats were embolized in right hemisphere with an autologous clot. Three groups are considered; A: control (n = 15), B: rt-PA i.v., 20 mg/kg starting 90-120 minutes after embolization (n = 15), C: rt-PA, same dose, and U-74389-G i.v., 3 mg/kg before and after embolization (n = 9). Arterial blood pressure, gasometry, glycemia and temperature were controlled. Volume of cerebral lesion in surviving animals 24 hours was measured. Autopsy was performed to verify the cause of death in rats which died. RESULTS: Mortality: group A: 8/15; group B: 9/15; group C: 8/9. Early death was related to cerebral injury except for five rats which developed peritoneal bleeding. We found severe acidosis in rats from group C. Differences in mean volume of ischemic lesion in group A and B are nosignificant despite a tendency to a reduction after thrombolysis. CONCLUSIONS: In this model thrombolysis alone and in association with U-74389-G failed to reduce cerebral lesion and mortality.

Animals↗
PubMed1997

Results at 43 months' follow-up of a double-blind, randomized, prospective clinical trial using intravesical interferon alpha-2b in the prophylaxis of stage pT1 transitional cell carcinoma of the bladder.

OBJECTIVES: To assess the intravesical efficacy of 60 million units of interferon (IFN) alpha-2b in preventing recurrences of Stage pT1 transitional cell carcinoma of the bladder, as well as to assess its local and systemic toxicity. METHODS: A total of 90 patients were included in a double-blind, randomized, prospective clinical trial and divided into two groups of 45 patients. After complete transurethral resection, 60 million units IFN alpha-2b was instilled in one group; in the other, double-distilled water was used. The therapeutic regimen consisted of weekly instillation for 12 weeks, followed by once-monthly instillation until patients had completed 1 year of treatment. RESULTS: Only 78 patients were evaluable. After 12 months of follow-up, the relapse rate was 28.2% (11 of 39) for the IFN group and 35.8% (14 of 39) for the control group (P = NS). After 43 months (range 9 to 67), relapse rates were 53.8% (21 of 39) and 51.2% (20 of 39), respectively (P = NS). Progression, mortality, and local or systemic toxicity were similar in both groups. Flu-like syndrome was not reported. CONCLUSIONS: At the dose used in this study, IFN alpha-2b proved ineffective in the prophylaxis of Stage pT1 transitional cell carcinoma of the bladder compared with a control group. Toxicity was virtually absent.

Administration, Intravesical↗
PubMed1996

Transcriptional analysis of the 5'-noncoding region of the human involucrin gene.

Human involucrin whose gene transcription is directed by a 2456-nucleotide (nt) 5'-noncoding region is a structural component of the epithelial cornified layer. Transient transfection assays demonstrated that this region is transcriptionally active in multiplying keratinocytes and is enhanced by 2 mM CaCl2 treatment. Calcium-independent transcriptional activity and the interaction with the AP-1 transcriptional factor was located on the proximal part (nt -159 to -1) of the 5'-noncoding region. However, CaCl2 responsiveness was mapped to a distal 1185-nt fragment (nt -2456 to -1272). Moreover, this fragment potentiated the Herpes simplex thymidine kinase promoter in normal keratinocytes and is responsive to calcium treatment in a cell type-specific manner. Interestingly, the absence of a 491-nt fragment located between the two enhancer domains (nt -651 to -160) resulted in transcriptional activation in multiplying keratinocytes. This fragment interacts with AP-1 and the YY1 transcriptional silencer. It is concluded that human involucrin 5'-noncoding region contains at least three regulatory domains, a distal CaCl2-responsive enhancer, a putative transcriptional silencer (that interacts with AP-1 and YY1), and a proximal enhancer/promoter (that interacts with AP-1). Thus, this study demonstrates the presence of particular transcriptional factors can potentially regulate the human involucrin expression.

Animals↗
PubMed1996

Primary cranial vault lymphoma mimicking meningioma.

Primary lymphomas of the cranial vault are rare; only six patients have been described in the literature. We report a 75-year-old woman who was admitted to our hospital after a focal seizure. CT showed a homogeneous mass which, on contrast enhancement, was similar to a meningioma. The tumour was excised and found to be a centroblastic, centrocytic non-Hodgkin's lymphoma. Treatment was completed with radiotherapy and chemotherapy.

Aged↗
PubMed1996

Hepatitis B virus (HBV)/hepatitis D virus (HDV) coinfection in outbreaks of acute hepatitis in the Peruvian Amazon basin: the roles of HDV genotype III and HBV genotype F.

Recurring outbreaks of acute hepatitis have been a significant cause of morbidity and mortality among Peruvian military personnel stationed in the Amazon Basin region of Peru. The role of hepatitis B virus (HBV) and hepatitis D virus (HDV) infection was investigated as the possible cause of acute hepatitis among 88 military patients stationed at four different jungle outposts during 1992-1993. Analysis of serum markers indicated that 95% (84/88) had evidence of acute HBV infection; 64% (54/84) were also infected with HDV. Genetic analysis of PCR-amplified HDV and HBV fragments showed exclusively HDV genotype III and HBV genotype F. Furthermore, HDV RNA sequences were similar among patients from the same outpost but different from those at other jungle locations. The data suggested focal sources of HDV infection in the jungle environment of the outposts and, further, confirmed the unique association of HDV genotype III with severe cases of human disease in northern South America.

Acute Disease↗
PubMed1996

Introducing ambulatory care during the medicine clerkship: impact on evaluation and attitudes.

This article assesses student attitudes and the overall educational impact after a major curriculum change that implemented ambulatory care in an internal medicine clerkship. The study was cross-sectional with a historical comparison group and took place in a university teaching program with third-year students from three time periods. The 8-week clerkship was changed from 8 weeks of inpatient ward medicine to 4 weeks each of inpatient and ambulatory care in both primary care and subspecialty clinics. When students' responses before and after the curriculum change were compared, there was a significant improvement in evaluation of the clerkship experience (P = 0.001). Attitudes improved toward a general internal medicine career (P = 10(-5)) and there was improvement in evaluation of the inpatient experience (P = 0.01). Attitudes toward careers in subspecialty internal medicine and National Board examination scores were unchanged. The institution of ambulatory care into this internal medicine clerkship resulted in several significantly positive outcomes without a negative impact on the internal medicine knowledge base.

Ambulatory Care↗
PubMed1996

[The advantages of associating ischemia/reperfusion injury inhibitors with intravenous thrombolysis when treating focal brain ischemia: a description of experiments using rats].

Restoration of blood flow is necessary when treating brain ischemia. However, except in very early cases, this is insufficient to prevent the cascade of mediators of cell damage unleashed by ischemia which, on the other hand, is boosted by the deleterious effects of reperfusion. We therefore consider adequate treatment for brain ischemia ought to associate, early on, reperfusion with pharmacological inhibition of those intermediaries in damage caused by ischemia/reperfusion (cytoprotection), basically an excess of cytosolic calcium and of free radicals. In this way, spreading of the infarct may be avoided more effectively than just with reperfusion alone. Our aim was to demonstrate this hypothesis using an experimental model. In order to do so, we shall embolize the right carotid artery territory of 50 Long Evans rats with autologous blood thrombi and check the location of the embolus using arteriography. Forty rats will receive thrombolytic treatment intravenously (rTPA at a dose of 20 mg/kg) two hours after embolization, while 10 control rats will receive similar treatment with saline serum. The thrombolysis treated animal group will be divided into four subgroups (A, B, C, D, ni = 10). Group A will be considered as the thrombolysis control group; group B will additionally receive calcium antagonists (dihydropyridines); group C will undergo antioxidant treatment (21-aminosteroids) and group D both calcium antagonists and antioxidants in association with thrombolysis. The size of infarct produced in each group, estimated following Cavalieri's principle, will be compared using nonparametric statistical tests (Mann-Whitney test and Willcoxon test). We present the preliminary results so obtained in a group of 14 control rats studied with the aim of assessing the usefulness of the proposed model.

Animals↗
PubMed1995

Palisaded encapsulated neuroma of the glans penis.

A case is reported of an 84-year-old white man in whom a palisaded encapsulated neuroma (PEN) had developed in his glans penis over the course of 50 years. It represents a distinctive cutaneous nerve sheath tumor that consists of an overgrowth of both axons and Schwann cells and is surrounded by a complete or incomplete capsule of perineural cells. This entity warrants wider recognition by urologists and uropathologists. To our knowledge this is the first description of this kind of tumor in the glans penis.

Aged↗
PubMed1995

Core needle aspiration biopsy of palpable breast masses.

The purpose of the present study was to determine the usefulness of core needle aspiration biopsy (CNAB) with an 18-gauge modified menghini needle in the preoperative evaluation of 145 palpable breast masses as the major indicator for definitive treatment by surgery. Of the 145 lesions histologically verified by surgery, 126 were diagnosed as carcinoma, of which 117 were correctly diagnosed by the needle biopsy (93%). CNAB showed a sensitivity of 90% in the diagnosis of breast malignancy and a specificity of 100%. The overall diagnostic accuracy was 91%. There were no false-positive results and after definitive diagnosis with the Menghini needle, a one-stage procedure without frozen sections could be performed for definitive treatment of breast carcinoma.

Adult↗
PubMed1995

Nonpalpable breast lesion. Stereotaxic core needle aspiration biopsy with a single pass.

One hundred and fifty-six patients with suspect nonpalpable breast lesion underwent stereotaxic core needle aspiration biopsy (SCNAB) with a single pass in an upright "add-on" stereotaxic device using a manual 1.6-mm needle (16 G), to determine whether the results were comparable to results of SCNAB with a multiple-pass technique. Of the 69 carcinomas, 51 (74%) were correctly diagnosed and definitive surgical therapy, without surgical biopsy, was performed in 42 of the 50 invasive carcinomas (84%) and in 9 of the 19 noninvasive carcinomas (47%). Ten noninvasive carcinomas and 4 invasive carcinomas, discovered by microcalcifications or distortion on the mammograms, form 78% of the false-negative results. There were no false-positive results. Vasovagal reactions occurred in 11% of the procedures. Although the results were acceptable in patients with invasive carcinoma, more than one needle pass is necessary for greater diagnostic accuracy of SCNAB, especially in patients with only microcalcifications or distortion on the mammogram.

Biopsy, Needle↗
PubMed1995

[Efficacy and tolerance of doxazosin in the treatment of isolated systolic hypertension in hypertensive patients over 60 years of age].

Isolated Systolic Arterial Hypertension (ISAH) is the most frequent form of AHT in the aged population, resulting in an increase of the cardiovascular risk, mainly at the cerebrovascular level. In this open non-comparative study, we analyze the effect of doxazosin, an alpha-adrenergic blocker in 40 patients older than 60 years, diagnosed of isolated systolic hypertension. After 2 weeks of lavage, the patients received treatment with doxazosin according to a monotherapy scheme, with progressive increase of the dose, from 1 to 16 mg/day during a period of 14 weeks. Doxazosin significantly reduces the systolic and diastolic arterial pressure (p < 0.001) with a therapeutical response in 86.5% of the cases, using an average dose of 3.4 mg/day and without observing modifications in the heart rate. This drug improves the lipidic profile, with a reduction of the plasmatic levels of total cholesterol and cholesterol linked to low density proteins (LDL) with p < 0.05 and a reduction of triglycerides. Among the 40 patients included in the study, 10 (25%) referred side effects; there were 2 drop-outs (5%) and the dose had to be reduced in 2 patients (5%). In conclusion, doxazosin shows its antihypertensive effectiveness in the treatment of isolated systolic hypertension in patients older than 60 years and it is well tolerated by most of the patients, improving at the same time the lipidic profile. Hence, it contributes to the reduction of the cardiovascular morbidity-mortality in this group of patients.

Age Factors↗