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Biomedical subjects

R Alvarez

Publications and source records attributed to R Alvarez.

At least 145 records · Page 8Linked to original sources
PubMed1995

Erythropoetin accelerates hematocrit recovery in post-surgical anemia.

UNLABELLED: We evaluated the role of recombinant human erythropoietin (RHE) for treatment of severe postsurgical anemia (Hct < 25%) in 40 Jehovah's Witness (JW) patients refusing transfusion. Twenty patients (group E) received RHE either at a loading dose of 300 U/kg iv 3 times/week for 1 week followed by 150 U/kg 3 times/week in accordance with an IRB approved protocol (N = 13), or at a dose of 100 U/kg 3 times/week for humanitarian reasons (N = 7). This group was compared to 20 similar JW patients who did not receive RHE (group C). All patients received iron restoration and nutritional support. Non-parametric analysis (Mann-Whitney) was used because of sample size. Entry hematocrit was similar for both groups: H(E)(0) = 15.8% +/- 1.1 SEM (8.5-23.4) vs HC (0) = 12.8% +/- 0.9 SEM (7.3-20.6), P = 0.09. After one week, hematocrit was significantly higher in group E (H(E)(1)) = 19.3 +/- 1.1 vs HC(1) = 12.5% +/- 0.9, P < 0.0005) as was the increase in hematocrit for group E (3.6% +/- 0.9 for E vs -0.4% +/- 0.8 for C, P < 0.005). Hematocrit change in Week 2 showed an increase for both groups (2.9 +/- 0.6 for E vs 4.9% +/- 1.2 for C, P = 0.12). CONCLUSIONS: Hct recovery shows a 1-week lag in severely anemic postsurgical patients treated without RHE. Exogenous RHE appears to accelerate hematocrit recovery in the first week. Use of RHE in the immediate postoperative period may help avoid or reduce homologous blood transfusion.

Anemia↗
PubMed1995

[Epithelioid hemangioendothelioma: a rare hepatic tumor].

We present a case of epithelioid hemangioendothelioma of the liver (EHL). The imaging techniques did not permit the diagnosis. A liver biopsy was done under laparoscopy. One year later, the patient remains without symptoms in spite of the presence of lung metastases and the therapeutic abstention. The most outstanding aspects of this rare hepatic tumor are discussed.

Adult↗
PubMed1995

[Priapism after intracavernous injection of PgE1 in two cases of impotence following total cysto-prostatectomy].

The authors report two cases of priapism of more than six hours, following intracavernous injection of 15 and 10 mcg PgE1 respectively, in six patients with impotence after radical cystoprostatectomy. Bearing in mind the proven safety of intracavernous injection of PgE1 in the treatment and diagnosis of erectile dysfunction, such a proportion of priapism in this group of patients has called our attention. It is probably due to an increased in the PgE1 intracavernous metabolism, due to the ligation of the penile venous drainage during surgery.

Alprostadil↗
PubMed1995

[In vitro sensitivity of Mycobacterium chelonae strains to various antimicrobial agents].

The in vitro susceptibility of 32 Mycobacterium chelonae strains to 10 antimicrobial agents was determined. The sources of the different strains were: clinical samples from patients treated at the Hospital Universitario de Canarias and Hospital del Tórax (General and Chest facilities) and from environmental sources (water supply, sewage, swimming pools and the sea). The susceptibility tests were performed by a broth microdilution method (Mueller-Hinton Broth). The results showed amikacin as the most effective antimicrobial agent against M. chelonae isolates, then ofloxacin and cefoxitin. However no statistical difference was detected among them. The least effective was imipenem, followed by ciprofloxacin and norfloxacin.

Amikacin↗
PubMed1994

1,2,3-Triazole-[2',5'-bis-O-(tert-butyldimethylsilyl)-beta-D- ribofuranosyl]-3'-spiro-5"-(4"-amino-1",2"-oxathiole 2",2"-dioxide) (TSAO) analogues: synthesis and anti-HIV-1 activity.

Several 4- or 5-monosubsituted and 4,5-disubstituted 1,2,3-triazole analogues of the anti-HIV-1 lead compound [1-[2',5'-bis-O-(tert-butyldimethylsilyl)-beta-D- ribofuranosyl]thymine]-3'-spiro-5"-(4"-amino-1",2"-oxathiole 2",2"-dioxide) (TSAO-T) have been prepared and evaluated as inhibitors of HIV-1-induced cytopathicity. These analogues have been prepared by 1,3-diplar cycloaddition of [2,5-bis-O-(tert-butyldimethylsilyl)-beta-D-ribofuranosyl]- 3-spiro-5'-(4'-amino- and 4'-(N-acetylamino)-1',2'-oxathiole 2',2'-dioxide) (TSAO) azides to various substituted acetylenes. Several 4- and 5-substituted 1,2,3-triazole-TSAO analogues proved superior to the unsubstituted derivative by 1-2 orders of magnitude. In particular the 5-substituted amido-, (methylamido)-, and (dimethylamido)-1,2,3-triazole derivatives of TSAO were endowed with potent anti-HIV-1 activity (50% effective concentration: 0.056-0.52 microM). They show a similar resistance spectrum as previously noted for TSAO-T and related derivatives.

Antiviral Agents↗
PubMed1994

Orbicularis oculi responses to stimulation of nerve afferents from upper and lower limbs in normal humans.

A brief mechanical or electrical stimulus to peripheral nerve afferents from the upper and lower limbs elicited a small and inconsistent EMG response of the orbicularis oculi muscles. This response was facilitated when the stimuli were delivered at fixed leading time intervals, of 45-300 ms, with respect to a supraorbital nerve electrical stimulus. Also, the peripheral nerve stimulus modified the conventional blink reflex responses, inducing facilitation of R1 and inhibition of R2. These results suggest a complex processing of sensory inputs from the face and the limbs at the brainstem, where they are probably integrated in a network of interneurons influencing the excitability of facial motoneurons.

Adult↗
PubMed1994

Vibration-induced presynaptic inhibition of the soleus H reflex is temporarily reduced by cortical magnetic stimulation in human subjects.

We have examined the effects of a transcranial magnetic stimulus (TMS) on the H reflex of the soleus muscle during vibration-induced presynaptic inhibition of the reflex, in seven normal volunteers. Without vibration, the H reflex was facilitated at interstimulus time intervals of > or = 5 ms after TMS. With vibration, the H reflex was markedly reduced or completely inhibited in control trials, but facilitation by TMS was noticed at intervals as short as -2.5 ms. These findings indicate an effect of TMS on the spinal interneurons mediating presynaptic vibratory inhibition of the H reflex.

Cerebral Cortex↗
PubMed1994

A health-sanitary evaluation of lacteal desserts for consumption in Santa Cruz de Tenerife.

The consumption of lacteal desserts in the province of Santa Cruz de Tenerife is notably high. However, there are no legal standards in Spain regarding microbiological quality. For this reason, we have decided that it would be of interest to carry out a health-sanitary study of these products, with the aim of discovering their microbial content. 330 samples of lacteal desserts on sale in the province of Santa Cruz de Tenerife have undergone analysis. They have been divided into three groups: cream caramel (egg and vanilla) (80), mousse (60) and the third group, known as "other desserts", which includes custard and the rest of lacteal desserts not included in the previous groupings (190). Neither E. coli, Salmonella spp., Shigella spp., nor Staphylococcus aureus have been detected in any of the samples analysed. In spite of the fact that the results obtained do not reflect high microbiological contamination, we consider it necessary to lay down legal standards, with reference values, for these lacteal products, which will guarantee good microbiological quality.

Bacteria, Aerobic↗
PubMed1994

Responses of the soleus muscle to transcranial magnetic stimulation.

Soleus muscle responses are difficult to elicit by cortical stimulation in normal humans at rest. We have studied in normal volunteers the behavior of the soleus and tibialis anterior muscle responses to maximal intensity transcranial magnetic stimulation (TMS) in the following experimental conditions: lying in supine position, active ankle dorsal flexion, active plantar flexion, standing on the soles, standing on the toes, and standing on the heels. At rest, consistent responses were recorded in the soleus to 61% of the stimuli, only. Maximal facilitation of the response in the soleus occurred when standing on the toes. In this condition, responses were recorded to 100% of the stimuli, at a latency that was, on average, 5.2 msec shorter than the latency of the responses at rest, and similar to the latency of the responses recorded in the tibialis anterior muscle when standing on the heels. Central motor conduction time, calculated in conditions of maximal facilitation, was not different for soleus or tibialis anterior muscles. We conclude that the soleus muscle receives short latency excitatory inputs from cortico-spinal axons activated by TMS, with a conduction time similar to that for the tibialis anterior. Such short latency cortico-spinal connections to the soleus muscle may become functionally effective only during maximum enhancement of motoneuronal excitability by muscle contraction.

Adult↗
PubMed1994

Cloning and expression of a 5-hydroxytryptamine7 receptor positively coupled to adenylyl cyclase.

A cDNA clone (designated as GP2-7) encoding a novel 5-hydroxytryptamine (5-HT) receptor was isolated from a guinea pig hippocampal library. The receptor shares amino acid homology within the hydrophobic domains with other cloned 5-HT receptor subtypes (34-48%). The sequence of GP2-7 is homologous to that described for a novel receptor previously cloned from a rat brain cDNA library and provisionally designated as 5-HT7. mRNA for GP2-7 was detected in cortical and limbic brain regions. Transiently expressed GP2-7 showed high-affinity binding to [3H]5-HT (pKi = 9.0) with the following rank order of affinities: 5-carboxyamidotryptamine (5-CT) > 5-HT = 5-methoxytryptamine (5-MeOT) > methiothepin > 8-hydroxy-2-(dipropylamino)tetralin (8-OH-DPAT) > spiperone >> sumatriptan. Adenylyl cyclase activity in CHO-K1 cells transiently transfected with GP2-7 was stimulated by several analogues of 5-HT with the following order of potency: 5-CT > 5-HT = 5-MeOT > dipropyl-5-CT > 8-OH-DPAT. Methiothepin and spiperone were potent antagonists. Preliminary analysis suggests that GP2-7 closely resembles a receptor in the guinea pig hippocampus that exhibits a high affinity toward 5-CT.

Adenylyl Cyclases↗
PubMed1994

[Intermittent hydronephrosis].

Intermittent hydronephrosis is a frequent cause of obstruction in the ureteropelvic junction in the adult. Diagnosis is based on intravenous pyelography, echography and renal scintigraphy with or without hyperdiuresis. We report a case of intermittent hydronephrosis successively affecting both kidneys.

Adult↗
PubMed1993

The cDNA of a human lymphocyte cyclic-AMP phosphodiesterase (PDE IV) reveals a multigene family.

Five protein families are needed to encompass the diversity of cyclic-AMP (cAMP) phosphodiesterases (PDE). Family IV PDEs (PDE IV) specifically hydrolyze cAMP with a low Km, and are selectively inhibited by rolipram (Rp) and related drugs. Cloned cDNAs from rat (r) suggest that the PDE IV family comprises four distinct members, designated A, B, C and D. Using RN from a human lymphocytic B-cell line (43D-Cl2), we have isolated a 3.8-kb cDNA by low-stringency screening using a rat PDE IV member B (r-PDE IVB) probe. Expression of the human (h) cDNA in Escherichia coli results in cAMP-specific PDE activity that is Rp sensitive. A single large open reading frame (ORF) predicts a 564-amino-acid protein with 92.9% identity to r-PDE IVB; at the nucleotide level the identity is 86.3%. This h-PDE IVB clone, HPB106, differs from a related cDNA clone isolated by others from h-monocytes [Livi et al., Mol. Cell. Biol. 10 (1990) 2678-2686]. Our analysis identifies the monocyte clone with r-PDE IVA. Southern blots using a 1.2-kb h-PDE IVB probe at low stringency suggest the presence of additional uncloned human PDE IV family members. Analysis of genomic Southern blots using short specific probes from the h-PDE IVA and h-PDE IVB cDNAs indicates that distinct genes encode these two PDE IV family members. RNA from fractionated normal human leukocytes shows major specific messages of 3.0 and 4.6 kb for h-PDE IVA and 3.7 kb for h-PDE IVB.(ABSTRACT TRUNCATED AT 250 WORDS)

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1993

The carbamate insecticide ZZ-Aphox induced structural changes of gills, liver, gall-bladder, heart, and notochord of Rana perezi tadpoles.

Embryos of Rana perezi were kept under laboratory conditions and treated with carbamate ZZ-Aphox at chronic doses of 0.02% and 0.14% for 9 weeks. Both the histological study and the analysis of mortality show a direct relationship between the dosage and the effects of the pesticide. The histological study of the survivors over 56 days show damages in gills, liver, gall-bladder, heart, and notochord. Damages on the epithelial of gills (on their distal portion) and gall-bladder recover over a few days, whereas those provoked on the compacting of the hepatic parenchyma and the hepatocytes, the auricle and the perintocohordal collagenic fibers alter their structure in a lasting way. Potentials of such alterations are discussed, with special reference to the possible interference of the pesticide on the successful synthesis of the supporting connective sheaths.

Animals↗
PubMed1993

Carboplatin, methotrexate, vinblastine and epirubicin (Carbo-MVE) for transitional cell bladder carcinoma.

BACKGROUND: MVAC is considered the most effective chemotherapy regimen for transitional cell bladder carcinoma. However, due to its significant toxic effects we substituted carboplatin for cisplatin and epirubicin for adriamycin in an attempt to produce the same response with less toxicity. PATIENTS AND METHODS: Twenty-seven patients with invasive transitional cell bladder carcinoma received Carbo-MVE: carboplatin (300 mgr/m2 d2), methotrexate (30 mgr/m2 d1, 15, 22), vinblastine (3 mgr/m2 d2, 15, 22) and epirubicin (30 mgr/m2 d2) every 4 weeks. RESULTS: There were 2 complete clinical responses (8.4%), 5 partial clinical responses (20.8%), 8 stabilizations (33.3%) and 9 progressions (37.5%). The overall clinical response rate was 29.2% (11%-47.4%, 95% CI), but 2 partial clinical remissions were not pathologically confirmed; were they to be considered as non-responses the response rate would fall even lower (20.8%). Toxicity was moderately severe, with 77.8% developing WHO grade III-IV granulocytopenia, 22.2% grade III-IV thrombocytopenia and 59.3% grade II-III vomiting. There were no toxic deaths nor any renal toxicity. CONCLUSIONS: Our results suggest that Carbo-MVE is less active and at least as hematotoxic as multiagent CDDP-based regimens.

Aged↗