Biomedical subjects

J Benavente

Publications and source records attributed to J Benavente.

At least 37 records · Page 2Linked to original sources

PubMed1996

[PSA and hormone-refractory period in prostatic cancer].

Study of the characteristics of the hormone-refractory period in 32 patients with disseminated prostate cancer who had achieved a complete response to total androgen suppression, appreciating in all of them a subclinical or asymptomatic stage and a clinical or symptomatic one. The subclinical stage was characterized by raised PSA levels and ranged between 3-35 months; at 12 months 59% of patients had advanced to the symptomatic stage, while at 24 months this percentage is 84%. The clinical stage extends from appearance of symptoms to the patient's death, ranging from 3 to 32 months; at 12 months 41% has died; and 91% at 2 years.

Adenocarcinoma↗

PubMed1996

[Wünderlich syndrome caused by metastatic gastric sarcoma in the kidney. Report of a case].

Contribution of one case of Wünderlich Syndrome secondary to a simple metastasis to the right kidney from a gastric sarcoma operated three years earlier. Pain, palpable mass on the side and decreased haematocrit were the primary symptoms. Diagnosis was confirmed by Computerized Axial Tomography. The therapeutical approach was radical nephrectomy. At 5 years, this female patient remains alive showing no evidence of tumoral disease in the follow-up controls performed.

Aged↗

PubMed1995

Endogenous enzymatic activities of the avian reovirus S1133: identification of the viral capping enzyme.

Avian reovirus S1133 was shown to contain all the enzymatic activities required for the synthesis of mature viral transcripts, including a dsRNA-dependent RNA polymerase, a nucleoside triphosphate phosphohydrolase, an mRNA guanylyltransferase, and two mRNA methyltransferases. The virus used these enzymes both in vitro and in vivo to catalyze the synthesis of viral mRNAs containing a type-1 cap at their 5' ends. Incubation of reovirions with GTP led to the formation of an intermediate structure consisting of GMP bound to the viral core protein lambda 3 through a phosphoamide linkage. The reaction was specific for GTP and required the presence of both Mg2+ and inorganic pyrophosphatase. The GMP moiety can be transferred from the lambda 3-GMP complex to acceptors such as GDP and GTP, yielding GpppG and GppppG, respectively. Our results demonstrate that lambda 3 is the avian reovirus guanylyltransferase.

Adenosine Triphosphate↗

PubMed1995

[Polypoid cystitis mimicking bladder tumor].

Presentation of one case of polypoid cystitis in a 38 year-old male, with no urological history. The form of clinic presentation and the endoscopic exploration induced to suspect the existence of a bladder tumour. Diagnosis was confirmed by the result of the histopathological study of the piece.

Adult↗

PubMed1994

Protein coding assignment of avian reovirus strain S1133.

Avian reovirus S1133 encodes 10 primary translation products, 8 of which are structural components of the viral particle and 2 of which are nonstructural proteins. The identity of the gene that codes for each of these polypeptides was determined by in vitro translation of denatured individual genome segments.

Animals↗

PubMed1994

[Controversies and progress in the diagnosis and treatment of benign prostatic hypertrophy. Personal experience].

Historically, non surgical procedures awakened little interest among urologists because surgery represented a definite solution with acceptable morbidity and mortality rates. Currently, the diagnosis and management of BPH is pointed towards a greater understanding of those prostate conditions with a trend to obstruction, using more refined methods to assess the severity of the obstruction, identification of predictive parameters of the therapeutical response, and evaluation of the various treatment alternatives based on safety and cost-efficiency parameters.

Humans↗

PubMed1993

Electrical conductivity of differently treated isolated cuticular membranes by impedance spectroscopy.

A comparative study of the electrical properties of isolated tomato cuticles (native, Na+, and Ca2+ forms) in contact with different NaCl solutions has been performed by impedance spectroscopy measurements. In all cases, equivalent circuits consisting of a parallel combination of a constant phase element and a resistance were found, and variation with NaCl concentration of both parameters has been considered. From the electrical parameters, the cuticle conductivities and equivalent capacities were determined, and a comparison between conductivity values at C = 0 (without electrolyte contribution) and those obtained with dry membranes is also made. Differences in conductivity and capacity values for the three cuticles are explained by some changes in the structure and electrical interactions.

Calcium↗

PubMed1993

[Acute scrotum as clinical presentation form of testicular tumor].

Testis tumours usually emerge in young patients as a painless increase in the testis size accidentally noticed by the patient. Contribution of one case of non-seminomatous testis tumour which presented clinically as an acute scrotum. An exhaustive appraisal of the clinical data allowed to choose the most appropriate approach for the patient in an emergency situation.

Acute Disease↗

PubMed1993

[Inverted papilloma of the urethra].

The inverted papilloma of the urethra is an exceptional entity. It occurs as a smooth surface, sessile tumour located in the prostatic urethra. Microscopically, it is lined with transitional epithelium which is projected inside the tumour, creating strands of cells with normal characteristics. All cases reported up to now have occurred in men aged between 49 and 79. None of the cases had additional urothelial injuries associated. Contribution of a new case of inverted papilloma of the prostatic urethra in a 52-year old male. Transurethral resection of the tumour was the procedure chosen. Evolution was good and no relapse nor further urothelial injuries were observed at the controls carried out over an 8-year follow-up period.

Humans↗

PubMed1993

[Renal leiomyosarcoma].

Presentation of one case of a large, rapidly growing and highly aggressive renal leiomyosarcoma. The diagnostic and therapeutical possibilities of this infrequent tumour are analyzed.

Aged↗

PubMed1992

[Non-chromaffin non-functioning aortosympathetic paraganglioma].

The paraganglia system is the largest component in the construction of the Disseminated Neuroendocrine System, comprising cells derived from the neural crest, with ability to synthesize and secrete catecholamines, hormones and peptides. A general explanation on the subject with a personal contribution is made.

Adult↗

PubMed1992

[Results of treatment with interferon and vinblastine in renal cancer].

Contribution of our experience with Alpha-2a Interferon and Vinblastine, for the treatment of advanced renal cancer in patients formerly not treated with nephrectomy. Pathoanatomical diagnosis was confirmed by puncture biopsy. None of the 4 patients recruited in the protocol showed objective response. In 2 patients no change was observed and in the other 2 the disease progressed. In surviving patients it was impossible to sustain therapy for more than three months. Treatment was discontinued as a result of the Interferon side-effects, such as fever, myalgia, asthenia and neuritis.

Biopsy, Needle↗

PubMed1991

A study of membrane potential across isolated fruit cuticles for NaCl and CaCl2 solutions.

Fixed charge density and ionic diffusion ratio in an isolated tomato fruit cuticular membrane have been estimated from membrane potential measurements for NaCl and CaCl2 electrolyte solutions. The values of the parameters studied show marked differences in the electrical behaviour of the electrolytes, and evidence the asymmetric character of the cuticular membrane. While the membrane potential values for NaCl solutions can be explained in terms of a Donnan potential plus diffusion potentials, for CaCl2 solutions the membrane potential values agree very well with the diffusion potential. These facts could be explained by taking into account some structural features of the cuticular membrane.

Calcium Chloride↗

PubMed1991

Avian reovirus S1133 can replicate in mouse L cells: effect of pH and cell attachment status on viral infection.

Previous reports have suggested that avian reovirus S1133 fails to replicate in mouse L cells. In this article, we report that replication does occur under certain culture conditions. The avian reovirus was found to grow in mouse L cells at pH 6.4 and 7.2 but not at pH 8.2. Culture medium with a basic pH directly inhibited viral transcription and genome replication. As a result, viral protein synthesis was also affected. At permissive pH levels, avian reovirus grew better in monolayers than in suspension cultures of L cells because of the influence of cell attachment status on viral macromolecular synthesis. Our results not only show that avian reovirus can replicate in mouse L cells but also help to explain why it did not in previous studies.

Animals↗

PubMed1991

The stimulatory effect of actinomycin D on avian reovirus replication in L cells suggests that translational competition dictates the fate of the infection.

Indirect immunostaining of avian reovirus S1133-infected L-cell monolayers showed that most of the cells can support viral replication. However, the number of cells in which the virus was actually replicating depended on the multiplicity of virus infection. The presence of actinomycin D during infection increased viral protein synthesis, viral growth, and the number of actively infected cells at late infection times. The antibiotic elicited these effects by triggering viral replication in cells that already contained unproductive cytoplasmic virus but that would not get productively infected in the absence of the drug. From these results, we propose a model for the interaction between L cells and avian reovirus S1133 in which viral versus host mRNA competition for the translational machinery determines the fate of the virus infection.

Animals↗

PubMed1989

Social change and early fertility decline in Catalonia.

"This article attempts a description of the fertility and nuptiality patterns of a group of selected localities in Catalonia [Spain] from the late eighteenth century to the mid-nineteenth century. The pattern of fertility transition in Catalonia can be described as starting from nuptiality conditions of early and quasi-universal marriage. The pattern of nuptiality is preserved throughout the process in its essentials. The transition, then, was largely limited to a decline in marital fertility. The evidence suggests an onset occurring in the 1830s, closer to the French experience than to that of any other Western European country. Finally, the analysis of the 84 local areas supports the proposition that structural factors had a significant effect on both the mid-nineteenth century level of marital fertility and the rate of decline during the 70-year period under study." (SUMMARY IN FRE)

Demography↗

PubMed1988

Avian reovirus mRNAs are nonfunctional in infected mouse cells: translational basis for virus host-range restriction.

Avian reovirus S1133 penetrates and uncoats in suspension cultures of mouse L cells. The multiple species of viral transcripts are produced in the cytoplasm of the infected cell, but they fail to associate with polysomes, consistent with the absence of viral protein synthesis. The selective block in avian virus mRNA translation is not overcome by coinfection with mammalian reovirus type 3, which replicates in mouse L cells, or by hypertonic shock or exposure to a low concentration of cycloheximide. Although the avian viral transcripts are inactive in vivo, RNA extracted from infected, nonpermissive L cells directs the synthesis of a normal spectrum of viral proteins in rabbit reticulocyte lysates. These results indicate that avian viral transcription is not restricted in mouse cells and that viral replication is prevented at the level of initiation of protein synthesis.

Animals↗

PubMed1986

Mode of sensitivity and resistance of vaccinia virus replication to interferon.

In this study we show that vaccinia virus replication can be sensitive or resistant to interferon (IFN) in the same strain of mouse L cells. When IFN-treated L cells were maintained in suspension culture, infection led to a rapid inhibition of both viral and cellular protein synthesis together with breakdown of viral RNA and of rRNA. When IFN-treated L cells were maintained in monolayer culture, infection did not lead to significant inhibition of viral protein or RNA synthesis and breakdown of viral or of rRNA was not observed. The resistance of vaccinia virus replication to IFN was not dependent on the input multiplicity or state of growth of the cells (actively dividing or resting). Qualitative and quantitative differences in viral transcription and translation were observed between the two virus-cell systems. Our findings are consistent with the hypothesis that the sensitivity or resistance of vaccinia virus to IFN is mediated by specific viral products that act as activators or selective inhibitors of, at least, the dsRNA-dependent ppp(A2'p)nA synthetase/RNase system.

2',5'-Oligoadenylate Synthetase↗