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J Crespo

Publications and source records attributed to J Crespo.

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

P2Y receptor subtypes differentially couple to inwardly-rectifying potassium channels.

Subtypes of P2Y receptors are well characterized with respect to their agonist profile but little is known about differences in their intracellular signalling properties. When expressed in Xenopus oocytes, both P2Y2 and P2Y6 receptors effectively couple to endogenous Ca2+-dependent Cl--channels. However, only P2Y2 receptors increased currents mediated by inward-rectifier K+ channels of the Kir3.0 subfamily. This increase in Kir-current was sensitive to pertussis toxin, while activation of Ca2+-dependent Cl--channels was not. In contrast, suramin, a P2 receptor antagonist, inhibited activation of both channels. These observations suggest that, in contrast to P2Y6, P2Y2 receptors couple to two different classes of G proteins.

Adenosine Triphosphate↗
PubMed1998

Effect of the protein kinase inhibitors, 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine H-7 and N-(2-[methylamino]ethyl)-5-isoquinoline-sulfonamide H-8 on Lewis lung carcinoma tumor progression.

The effects of 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine H-7 (a cAMP-dependent protein kinase and protein kinase C inhibitor), n-(2-[methylamino]ethyl)-5-isoquinoline-sulfonamide H-8 (a cAMP- and cGMP-dependent protein kinase inhibitor) and indomethacin (IND, a cyclooxygenase inhibitor) on both the spontaneous metastatic ability of 3LL (Lewis lung carcinoma) tumor cells and anti-tumor host response were studied. The study of tumor progression showed that H-7 and H-8 (2 mg kg(-1) day(-1) , i.p., for 8 days) significantly reduced the mean number of metastases (0.8 +/- 0.2 and 1.0 +/- 0.7, respectively, P < 0.05) with respect to the number of lung metastases (4.2 +/- 2.1) observed in the control group. In turn, the highest tumor-specific cytotoxicity response (50% increase vs. non-treated target cells) was observed when both animal and tumor cells were treated with H-8. This suggests that the protein kinase inhibitors could inhibit tumor progression toward lung metastases formation by blocking the immunosuppressor mechanism triggered by agents that increase intracellular cAMP.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1998

Alcoholic recidivism after liver transplantation for alcoholic cirrhosis.

Liver transplantation (LT) for alcoholic cirrhosis remains controversial. This controversy surrounding LT in alcoholics focuses on the risk of alcohol recidivism and on potential noncompliance with the immunosuppressive regimen, both of which result in graft failure. Our study examined alcohol recidivism after LT by measuring alcohol in urine and its repercussion on the allograft. Forty-four consecutive alcoholic patients and a comparison group of 17 patients receiving LT were included in this study and followed up for a mean of 39.5 +/- 19.6 months. Seven percent (3 of 44) of patients with alcoholic liver disease and 0% of patients in the comparison group admitted to having used alcohol after LT. Alcohol in urine, however, was detected in 18% (8 of 44) of the alcoholic group; therefore the true recidivism rate was higher than the rate admitted. All patients in both groups were compliant with the medications, because the cyclosporine levels were within the therapeutic range in all. On histologic examination the only alcohol-induced lesion found in three of the eight recidivistic patients was steatosis. Therefore, although alcoholic recidivism occurs, it does not seem to affect compliance to treatment profoundly or to compromise graft function. Therefore, LT seems justified for end-stage alcoholic cirrhosis.

Adult↗
PubMed1998

Disseminating multimedia protocols over Internet for emergency and catastrophe management.

Over the last years we have developed various computing methods to assist specialized personnel on various aspects of catastrophe and emergency management. New models can address tasks such as patient triage; stabilization, resource coordination and hospital alertness and techniques based on information technologies. In this paper we present various tools (written on Java and C+2) that we created to store, represent, and disseminate practice guidelines and protocols over the World Wide Web. Guidelines and protocols are stored using a standard database program (e.g., Microsoft Access), and represented in a flowchart format linked to multimedia information such as text, pictures, sound, video or external sources of data. Using our JAVA tool, protocols can be disseminated over the Web and viewed with any browser with JAVA compliance. We have implemented 15 emergency protocols that we developed in collaboration with specialized military personnel from the Ministry of Defense, Spain. Users can access remotely those electronic protocols comparing their procedures and methods. Our goal is to enhance agreement and consensus among remote medical centers regarding emergency and catastrophe management, establishing discussions over the network. Our tools have also a potential for training medical and paramedical personnel for emergency situations.

Clinical Protocols↗
PubMed1998

A concept model for the automatic maintenance of controlled medical vocabularies.

A controlled medical vocabulary is a fundamental requirement in a range of medical informatics applications. Large vocabularies development and maintenance is labor intensive and costly. Maintainers of medical vocabularies need appropriate tools to do their work correctly. In this paper, we describe our concept model for a controlled medical vocabulary. We present how this model can check vocabulary consistency. We propose a set of tools in a distributed environment, which permits edition, visualization and maintenance of medical terminologies.

Humans↗
PubMed1998

Cost effective, hospital based occupational health services. Successful program.

1. Development of hospital based occupational health service programs focused on meeting business needs is a response to declining inpatient utilization rates, increasing numbers of physicians, and expanding payer control. 2. Nurse practice models using nurse practitioners have demonstrated high quality, cost effective care. 3. Responsiveness to meeting both employee client and employer needs is the key to successful program development.

Cost-Benefit Analysis↗
PubMed1997

[Recurrence of hepatitis caused by hepatitis c virus in patients receiving a liver transplant].

BACKGROUND: Liver disease due to hepatitis C virus (HCV) is an increasingly frequent indication for liver transplantation. We performed a clinical and virological study of 20 HCV-infected liver transplant recipients to correlate virological markers with histological recurrence of disease. PATIENTS AND METHODS: In ninety-four patients who were given transplants for end-stage cirrhosis, IgG and IgM antibodies to HCV and IgM to HCV tested by ELISA; all samples were further examined in a four-antigen recombinant immunoblot assay (2-RIBA). HCV viremia was measured by the conventional nested PCR, HCV genotype was determined by PCR amplification using type-specific primers. We have analyzed de novo infection by HCV, HCV recurrence and the influence of genotype in these recurrence. RESULTS: Nineteen of 20 antibody-positive patients (95%) had HCV RNA before transplantation. All 19 patients who were viremic before transplantation had persistent infection after LT. HCV genotype 1b was the predominant type before and after LT (75%). Ten of the 20 (50%) patients developed histological findings of chronic hepatitis (CH) in liver allografts. HCV recurrent liver disease after LT was not related with HCV genotype. Of 4 deaths after transplant in hepatitis C group, only one was related to recurrent disease. We have not found de novo hepatitis C. CONCLUSIONS: Our results indicate the general persistence of hepatitis C virus infection and the excellent short-term prognosis after liver transplantation. Chronic hepatitis by HCV in liver transplant was not related with HCV genotype.

Adult↗
PubMed1997

Viral replication in patients with concomitant hepatitis B and C virus infections.

The aim of this study was to assess the implications of dual infection with hepatitis B virus (HBV) and hepatitis C virus (HCV). The HBV and HCV status in 100 patients with chronic hepatitis was analysed. HBV DNA was studied using liquid hybridization and the polymerase chain reaction (PCR). HCV viremia was measured using qualitative and quantitative PCR. The HCV genotype was determined by PCR. Patients were divided into three groups according to their HCV-RNA and HBsAg status: group I consisted of 40 patients with chronic hepatitis caused by HBV; group II, 40 patients with chronic hepatitis caused by HCV; and group III, 20 patients infected with both viruses. The HBV-DNA level was higher in group I than in group III (66.4 vs. 11.5 pg/ml; p < 0.05). Quantification of HCV viremia revealed mean values of 36.9 copies x 10(5)/ml in group II and 5.5 copies/ml x 10(5) in group III (p < 0.05). The mean aminotransferase level and histological activity were higher in group III. HCV genotype lb was the predominant type. The data suggest that there is reciprocal inhibition of viral replication in patients with dual HBV and HCV infection. Liver disease appears to be more severe in patients with chronic hepatitis B and C.

Adolescent↗
PubMed1997

A JAVA-based multimedia tool for clinical practice guidelines.

We have developed a specific language for the representation of Clinical Practice Guidelines (CPGs) and Windows C++ and platform independent JAVA applications for multimedia presentation and edition of electronically stored CPGs. This approach facilitates translation of guidelines and protocols from paper to computer-based flowchart representations. Users can navigate through the algorithm with a friendly user interface and access related multimedia information within the context of each clinical problem. CPGs can be stored in a computer server and distributed over the World Wide Web, facilitating dissemination, local adaptation, and use as a reference element in medical care. We have chosen the Agency for Health Care and Policy Research's heart failure guideline to demonstrate the capabilities of our tool.

Computer Communication Networks↗
PubMed1997

ARMEDA: accessing remote medical databases over the World Wide Web.

We have created a computer system to access medical information located at remote databases over the World Wide Web, for epidemiological ad health services research. We made a preliminary prototype where a specific database model could be searched and information be retrieved. We are currently working on a new component-based architecture, where different databases scheme from various sites can be used to create a unified model, giving users a "virtual" vision of a single, local database. Different software engineering and artificial intelligence methods are used to access, integrate, filter and deliver information to users.

Computer Communication Networks↗
PubMed1997

Value of endothelin in cellular rejection after liver transplantation.

Endothelin-1 is a vasoconstrictor peptide released by the vascular endothelium by various chemical and mechanical factors. Cellular rejection is one of the most common complications following orthotopic liver transplantation, endotheliitis being its most specific and consistent histological feature. To assess the role of endothelin in cellular hepatic rejection, we studied 21 cirrhotic patients undergoing elective liver transplantation. These patients were divided in two groups: Group I comprised 10 patients without cellular rejection, and Group II comprised 11 patients with cellular rejection. Endothelin was measured on day 7 after transplantation, on the day of liver biopsy, and after treatment for rejection. We found a significant increase in the plasma endothelin levels in the early postoperative period in the patients with moderate or severe cellular rejection compared with the non-rejection group. It remained significantly elevated until the clinical diagnosis of rejection was made. This value returned to baseline with successful treatment. So, the monitorization of this peptide may be of help in the diagnosis of rejection, its severity, and the evaluation of its resolution.

Adult↗
PubMed1997

Hepatitis C virus recurrence after liver transplantation: relationship to anti-HCV core IgM, genotype, and level of viremia.

OBJECTIVES: Factors that determine the severity of hepatitis C virus (HCV)-recurrent disease in patients undergoing orthotopic liver transplantation (OLT) for HCV cirrhosis have not been clearly identified. To address this issue, we evaluated the histological and virological outcome in 25 patients who underwent OLT for HCV cirrhosis. METHODS: HCV-RNA was detected by qualitative and quantitative polymerase chain reaction. The HCV genotype also was determined by polymerase chain reaction. Anti-HCV core IgM was tested by ELISA. Disease severity was expressed as a histological score. RESULTS: Sixteen patients had evidence of HCV-recurrent disease. HCV-RNA levels before transplantation (p = 0.029) and after transplantation (15 days, p = 0.004; 90 days, p = 0.040; 360 days, p = 0.010) were significantly higher among patients who subsequently developed recurrent hepatitis than among those who did not. The presence of anti-HCV core IgM before (p = 0.044) and after OLT (15 days, p = 0.017; 90 days, p = 0.037; and 360 days, p = 0.040) was significantly related to recurrence of hepatitis. The genotype was not related to the level of viremia, to the prevalence of recurrent hepatitis, to the presence of anti-HCV core IgM, or to disease severity. CONCLUSIONS: The recurrence of HCV hepatitis in patients undergoing OLT for HCV cirrhosis is related to higher levels of viremia and the presence of anti-HCV core IgM, but not to the HCV genotype. However, disease severity is not related to viremia levels, HCV genotype, or positivity of anti-HCV core IgM.

Adult↗
PubMed1997

Plasma adrenomedullin levels in patients with hepatic cirrhosis.

OBJECTIVE: The role of adrenomedullin in cirrhosis is at present unknown. The aim of this study was to investigate plasma levels of adrenomedullin in cirrhosis. METHODS: We measured plasma adrenomedullin concentrations using radioimmunoassay in 43 patients with cirrhosis (17 in Child-Pugh's class A, 13 in Child-Pugh's class B, and 13 in Child-Pugh's class C) and compared these values with those in 24 age-matched healthy subjects. Renal function, plasma cyclic adenosine monophosphate (cAMP) concentration, plasma renin activity, and plasma aldosterone concentration were measured in each patient. RESULTS: Plasma adrenomedullin levels were increased significantly in patients with cirrhosis compared with healthy subjects. In addition, plasma adrenomedullin values were higher in patients with cirrhosis and ascites than in those without ascites. Moreover, plasma adrenomedullin levels increased in relation to the severity of cirrhosis. Significant positive correlations also were found between adrenomedullin and cAMP concentrations and plasma renin activity or plasma aldosterone concentrations. CONCLUSIONS: Plasma adrenomedullin is increased in patients with cirrhosis compared with healthy subjects. The increase in plasma adrenomedullin levels is related at least in part to the severity of cirrhosis and may contribute to the arteriolar vasodilation in patients with cirrhosis. These effects are related in part to a cAMP-dependent pathway.

Adrenomedullin↗
PubMed1997

Delivering health information services and technologies to urban community health centers: the Chicago AIDS Outreach Project.

Health professionals cannot address public health issues effectively unless they have immediate access to current biomedical information. This paper reports on one mode of access, the Chicago AIDS Outreach Project, which was supported by the National Library of Medicine through outreach awards in 1995 and 1996. The three-year project is an effort to link the programs and services of the University of Illinois at Chicago Library of the Health Sciences and the Midwest AIDS Training and Education Center with the clinic services of community-based organizations in Chicago. The project was designed to provide electronic access to AIDS-related information for AIDS patients, the affected community, and their care givers. The project also provided Internet access and training and continued access to library resources. The successful initiative suggests a working model for outreach to health professionals in an urban setting.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Human alpha 1-antitrypsin gene transfer to in vivo mouse hepatocytes.

The in vivo gene transfer to mouse hepatocytes of pTG 7101, a plasmid containing the full-length gene encoding human alpha 1-antitrypsin (alpha 1-AT) DNA, has been studied by iv administration of recombinant DNA (100 ng/mouse) encapsulated in large and small liposomes. Our results from immunohistochemical liver sections and cytophotometric analysis of hepatocyte chromophore absorbance indicate that human alpha 1-AT was expressed in liver parenchymal cells from mice treated (48 hr before) with DNA encapsulated in small liposomes, and this effect remained for at least 2 weeks. In contrast, the efficiency was greatly limited when large liposomes were used as a vehicle for gene transfer. Additional experiments were performed to study using an ELISA procedure the presence in mouse plasma of human alpha 1-AT from mice treated with encapsulated plasmid in small liposomes or small empty liposomes plus free DNA. According to the immunohistochemical data, the results indicate that detectable alpha 1-AT can only be observed in plasma from mice treated with encapsulated plasmid in small liposomes.

Animals↗
PubMed1996

[Hepatita B and C virus infections in patients with hepatocellular carcinoma].

BACKGROUND: The prevalence of HBV and HCV infections in patients with hepatocellular carcinoma may be related to variations in the geographic area of study. For this reason, we have analized the relative prevalence of HBV and HCV infections in 94 patients with hepatocellular carcinoma from Cantabria (North of Spain). PATIENTS AND METHODS: We have studied 94 patients with hepatocellular carcinoma from January 1988 to December 1993. Commercially available radioimmunoassay or ELISA were used for detection of HBsAg, anti-HBs and anti-HBc. The HBV DNA was analized by PCR. The HCV infection was assayed by ELISA-2 and RT-PCR. RESULTS: The HBV infection was detected in 27 patients: 19 patients were HBsAg positive and 8 patients HBsAg negative, anti-HBc positive, DNA HBV positive by PCR. The HCV infection was found in 57 patients. Forty patients were infected with both viruses. Of the remain twenty-four, forty were alcoholics. We found in 61 patients more than one etiological factor. Hepatoma was the first manifestation of liver disease in 24 cases and these were more frequently in HCV than in those with HBV infection. Moreover, the first group were older and have lower alcohol intake. CONCLUSIONS: 1) In Cantabria, Spain, the majority of cases of hepatocellular carcinoma are related to HBV, HCV and alcohol. 2) Analysis of DNA HBV and RNA HCV by PCR allows the diagnosis of cryptic infections by both viruses, especially in the cases of HBV and HCV coinfection. 3) Hepatoma is the first manifestation of liver disease in a high percentage of cases.

Adolescent↗