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Biomedical subjects

A Rivero

Publications and source records attributed to A Rivero.

At least 55 records · Page 3Linked to original sources
PubMed1997

Ovarian response to gonadotropin treatment initiated relative to wave emergence in ultrasonographically monitored ewes.

Follicular recruitment and luteal response to superovulatory treatment initiated relative to the status of the first wave of the ovine estrous cycle (Wave 1) were studied. All ewes (n = 25) received an intravaginal progestagen sponge to synchronize estrous cycles, and ewes were monitored daily by transrectal ultrasonography. Multiple-dose FSH treatment (total dose = 100 mg NIH-FSH-P1) was initiated on the day of ovulation (Day 0 group) in 16 ewes. In the remaining 9 ewes, FSH treatment was started 3 d after emergence of the largest follicle of Wave 1 (Day 3 group). Ewes received PGF(2alpha) with the last 2 FSH treatments to induce luteolysis. Daily blood samples were taken to determine progesterone profiles and to evaluate the luteal response subsequent to superovulation. The ovulation rate was determined by ultrasonography and correlated with direct observation of the ovaries during laparotomy 5 to 6 d after superovulatory estrus when the uterus was flushed to collect embryos. Results confirmed that follicular recruitment was suppressed by the presence of a large, growing follicle. In the Day 0 and Day 3 groups, respectively, mean numbers (+/- SEM) of large follicles (>/= 4 mm) recruited were 6.4 +/- 0.6 and 2.7 +/- 0.7 (P < 0.01) at 48 h after the onset of treatment, and 6.7 +/- 0.5 and 5.1 +/- 0.6 (P = 0.08) at 72 h after the onset of treatment. Ovulation rates were 5.6 +/- 0.8 and 3.3 +/- 0.8 in the respective groups (P < 0.05). The number of transferable embryos was 1.8 +/- 0.5 and 0.3 +/- 0.2 in the respective groups (P < 0.05). Short luteal phases (</= 3 d) associated with low serum progesterone (maximum of </= 1.4 ng/ml) were detected after superovulation in 1 16 and 6 9 ewes in the Day 0 and Day 3 groups, respectively (P < 0.001). In conclusion, gonadotropin treatment initiated at the time of emergence of Wave 1 induced a superovulatory response in ewes. Response was influenced by the status of the follicular wave. The presence of a large growing follicle at time of superstimulatory treatment was associated with lower follicle recruitment, fewer ovulations, fewer transferable embryos, and the development of functionally subnormal corpora lutea (CL). The results demonstrate that follicle dominance is operative during the early luteal phase of the ovine estrous cycle.

Journal Article↗
PubMed1997

Transmission between HIV-infected patients of multidrug-resistant tuberculosis caused by Mycobacterium bovis.

OBJECTIVE: To investigate outbreaks of multidrug-resistant tuberculosis (TB) by using DNA fingerprint databases. DESIGN: Investigation of two outbreaks of multidrug-resistant TB in separate hospitals in Spain by restriction fragment length polymorphism (RFLP) and spoligotyping. Outbreak strains were compared with more than 1500 RFLPs of Mycobacterium tuberculosis complex strains isolated in Spain and 6000 RFLPs from 30 different countries. METHODS: Standardized IS6110 DNA fingerprinting and 'spoligotyping' was used to type multidrug-resistant isolates belonging to the M. tuberculosis complex amongst the outbreak cases. The DNA types were matched against DNA fingerprint databases in Spain and The Netherlands. RESULTS: The DNA typing analysis indicated that a single multidrug-resistant Mycobacterium bovis strain was responsible for a nosocomial outbreak in a hospital in Spain involving at least 16 HIV-infected patients with non-treatable to multidrug-resistant TB. Introduction of the fingerprint type of this strain to the international database revealed a single matching strain. This strain was also isolated from an HIV-infected patient in The Netherlands who had died from multidrug-resistant TB. This patient had previously been hospitalized in Spain, where a multidrug-resistant TB nosocomial outbreak involving 20 HIV-infected patients was ongoing. The strains causing this outbreak were also identified as M. bovis with an identical DNA pattern to those strains isolated in the Spanish hospital and the patient in The Netherlands. CONCLUSIONS: The use of centralized DNA databases can help to identify rapidly the origin and transmission routes of multidrug-resistant TB across international boundaries and the potential use of such an early warning surveillance system for investigation of nosocomial multidrug-resistant TB outbreaks between HIV-infected patients. To our knowledge this is the first report of transmission of multidrug-resistant M. bovis between hospitals.

Bacterial Typing Techniques↗
PubMed1997

Effects of angiotensin-converting enzyme inhibitors on anemia and erythropoietin requirements in peritoneal dialysis patients.

In an attempt to assess the effect of angiotensin-converting enzyme inhibitors (ACEIs) on anemia and recombinant human erythropoietin (rHuEPO) requirements in peritoneal dialysis patients, we evaluated 5 patients treated with ACEIs for one year, and the results were compared with data from a control group (N = 5). In response to ACEIs, the mean hemoglobin value decreased progressively, reaching statistical significance after 6 months and thereafter (basal, 10.7 +/- 0.8; month 6, 10.3 +/- 0.9; month 12, 10.3 +/- 0.5 g/dL, p < 0.05), with no variations in the control group. The rHuEPO requirements experienced a progressive increase in ACEI-treated patients, from 4400 +/- 1516 U/week at basal to 8600 +/- 2880 U/week at the conclusion of the study (p < 0.01). Serum erythropoietin concentration remained stable during the study in both groups of patients. In conclusion, rHuEPO requirements necessary to maintain a stable hemoglobin concentration are greater in subjects under ACEI therapy. ACEI may be an important cause of resistance to rHuEPO, an effect not mediated by a decrease in endogenous erythropoietin.

Aged↗
PubMed1995

Single fiber electromyography of extraocular muscles: a sensitive method for the diagnosis of ocular myasthenia gravis.

We performed single fiber electromyography (SFEMG) in the superior rectus and levator palpebralis (SR-LP) muscles of 17 patients with pure ocular myasthenia gravis (MG) and 9 controls. Thirteen patients were also assessed with SFEMG in the orbicularis oculi (OO) muscle. All the MG patients but none of the control subjects showed abnormal SFEMG jitter in the SR-LP muscles. On the other hand, only 62% of the MG patients had abnormal SFEMG jitter in the OO muscle. The procedure was well tolerated by the patients, and complications were minor. We conclude that SFEMG of the SR-LP muscles is a safe and highly sensitive technique for the diagnosis of ocular MG.

Adult↗
PubMed1995

Association between hepatitis C virus seroreactivity and HIV infection in non-intravenous drug abusing prostitutes.

Two hundred and ninety-four non-transfused prostitutes from Spain, who denied intravenous drug abuse, were tested for hepatitis C virus (HCV) antibodies. Seventeen (5.78%) of them were seropositive. Both in univariate and correspondence analyses, serological results for hepatitis C were associated with the HIV-1 serostatus (p < 0.001), number of sex partners (p < 0.05) and a history of genital ulcers (p < 0.05). In logistic regression analysis, hepatitis C seropositivity was associated only with HIV-1 infection (adjusted odds ratio = 13.6; 95% confidence interval = 3.3-55.2). These results show that hepatitis C seropositivity is associated with HIV-1 infection in female non-intravenous drug abusing prostitutes. These findings are also consistent with the hypothesis that HCV can be sexually transmitted with low efficiency.

Adult↗
PubMed1995

Use of ambroxol and bromhexine as mucolytics for enhanced diffusion of furaltadone into tracheobronchial secretions in broilers.

1. Ambroxol and bromhexine were evaluated as mucolytics and to enhance the passage of furaltadone into tracheobronchial secretions (TBS) in chronic complicated respiratory disease-affected broilers. 2. Viscosity of TBS was noticeably increased in the ambroxol-treated birds and only slightly increased in the bromhexine groups; however, the physical (nature) of TBS was superior in the ambroxol-treated broilers. 3. There was a clear increase in the passage of furaltadone into tracheobronchial secretions only in the ambroxol-treated birds. 4. Everyday use of ambroxol in broilers is discussed.

Ambroxol↗
PubMed1994

Isolated renal mucormycosis in two AIDS patients.

Two cases of mucormycosis in patients with exclusively renal involvement and advanced HIV infection are reported. In both cases the clinical course was relatively benign; in one case a tendency towards regression with no specific treatment was observed, and in the other case the infection resolved after nephrectomy and antifungal therapy. Renal mucormycosis should be considered in the differential diagnosis of diffuse renal enlargement in HIV-infected patients.

AIDS-Related Opportunistic Infections↗
PubMed1994

Peroxisome enzyme modification and oxidative stress in rat by hypolipidemic and antiinflammatory drugs.

Changes in the activities of two peroxisomal enzymes (catalase and thiolase), some parameters related to oxidative situations, such as conjugated dienes, zinc, iron, copper and superoxide dismutase after the administration of two known peroxisome proliferators (clofibrate and acetylsalicylic acid), and two drugs pharmacologically related to the former (probucol and diflunisal) have been studied in male Wistar rats. Administration of the drugs was made by p.o. for 15 days. After the treatment the rats were killed, their livers and brains were taken out, and their blood was collected. Peroxisomes were purified by differential centrifugation followed by ultracentrifugation. Total RNA was also extracted and the acyl CoA oxidase mRNA expression was studied. Clofibrate was inactive on both enzymes studied in liver and diflunisal in brain. However, the acyl CoA oxidase mRNA expression increased by clofibrate treatment. Results are justified by the liposolubility and protein-binding properties of the drugs. Otherwise, the present results show the existence of an increased lipid peroxidation, lower value of superoxide dismutase, and variable results for zinc, copper and iron trace elements. These data evidence an oxidative stress situation in plasma of rats treated with these drugs, probably as a consequence of an increase in some beta-oxidation enzymes, which brings about an overproduction of H2O2.

Acetyl-CoA C-Acetyltransferase↗
PubMed1994

[Pneumothorax in patients with AIDS].

METHODS: From January 1986 to 31 November 1993, 354 cases of AIDS (CDC criteria 1987) were diagnosed. The possible existence of spontaneous pneumothorax at any time during the evolution and its presumed cause were evaluated. RESULTS: During the period studied, 7 (1.9%) of AIDS patients presented pneumothorax. The existence of a pulmonary infection was proven in 6: 3 pneumonia by Pneumocystis carinii, 2 bacterial pneumonia (Streptococcus pneumoniae and Pseudomonas sp.) and 1 tuberculosis. One patient presented a Pneumocystis carinii pneumonia 3 months prior to the pneumothorax. In the study period 88 (22.8%) of the AIDS patients presented pneumonia by Pneumocystis carinii and 181 (51.1%) presented tuberculosis. The rate of pneumothorax in patients with a history or presence of pneumonia by Pneumocystis carinii was of 4.5% and 0.5% in patients with tuberculosis. CONCLUSIONS: The development of pneumothorax is relatively frequent in patients with AIDS in our area. As found in other series, its most frequent cause was Pneumocistis carinii pneumonia, despite the high incidence of tuberculosis.

Acquired Immunodeficiency Syndrome↗
PubMed1994

[Bacteremia and recurrent arthritis caused by Streptococcus pyogenes in a heroin addict with AIDS].

BACKGROUND: Streptococcus pyogenes is a bacteria which, at present, is seldom isolated in blood and articular fluid. An intravenous drug addict with human immunodeficiency virus infection, with bacteremia and arthritis by S. pyogenes, associated with tuberculosis is presented. METHODS: Blood and articular fluid cultures were collected in the usual and Löwenstein-Jensen media. RESULTS: The patient improved with penicillin and tuberculostatic drugs. Nine months after this episode, the patient reinitiated intravenous drug addiction, and developed another presentation of bacteremia and arthritis by S. pyogenes. CONCLUSIONS: Heroin addict patients constitute a risk group for bacteremias ans severe infections by S. pyogenes.

Acquired Immunodeficiency Syndrome↗