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J Bosch

Publications and source records attributed to J Bosch.

At least 91 records · Page 5Linked to original sources
PubMed2000

CO(2) wedged hepatic venography in the evaluation of portal hypertension.

BACKGROUND/AIMS/METHODS: During hepatic vein catheterisation, in addition to measurement of hepatic venous pressure gradient (HVPG), iodine wedged retrograde portography can be easily obtained. However, it rarely allows correct visualisation of the portal vein. Recently, CO(2) has been suggested to allow better angiographic demonstration of the portal vein than iodine. In this study we investigated the efficacy of CO(2) compared with iodinated contrast medium for portal vein imaging and its role in the evaluation of portal hypertension in a series of 100 patients undergoing hepatic vein catheterisation, 71 of whom had liver cirrhosis. RESULTS: In the overall series, CO(2) venography was markedly superior to iodine, allowing correct visualisation of the different segments of the portal venous system. In addition, CO(2), but not iodine, visualised portal-systemic collaterals in 34 patients. In cirrhosis, non-visualisation of the portal vein on CO(2) venography occurred in 11 cases; four had portal vein thrombosis and five had communications between different hepatic veins. Among non-cirrhotics, lack of portal vein visualisation had a 90% sensitivity, 88% specificity, 94% negative predictive value, and 83% positive predictive value in the diagnosis of pre-sinusoidal portal hypertension. CONCLUSIONS: Visualisation of the venous portal system by CO(2) venography is markedly superior to iodine. The use of CO(2) wedged portography is a useful and safe complementary procedure during hepatic vein catheterisation which may help to detect portal thrombosis. Also, lack of demonstration of the portal vein in non-cirrhotic patients strongly suggests the presence of pre-sinusoidal portal hypertension.

Carbon Dioxide↗
PubMed2000

Sources of abnormal EEG activity in brain infarctions.

EEGs from 16 patients with stroke in three different stages of evolution were recorded. EEG sources were calculated every 0.39 Hz by frequency domain VARETA. The main source was within the delta band in 2 out of 4 chronic patients, and in 67% of the patients in the acute or subacute stages when edema (cytotoxic or vasogenic) was present. Moreover, all patients showed abnormal activity in the theta band. Sources of abnormal activity in cortical or corticosubcortical infarcts were located in the cortex, surrounding the lesion. At the site of the infarct, a decrease of EEG power was observed. Sources of abnormal theta power coincided with edema and/or ischemic penumbra.

Adult↗
PubMed2000

The sixth Carlos E. Rubio Memorial Lecture. Prevention and treatment of variceal hemorrhage.

The medical treatment of portal hypertension has experienced a marked progress in the past decade due to the introduction of effective portal hypotensive therapy. This has been possible because of the better understanding of the pathophysiological mechanisms leading to portal hypertension. A major step forward was the introduction of beta-blockers for the prevention of bleeding and rebleeding from gastroesophageal varices. Effective therapy requires the reduction of the hepatic venous pressure gradient (HVPG) to 12 mmHg or below, or at least by 20% of baseline values. Unfortunately, this is only achieved in 1/3 to 1/2 of patients. Combination therapy, associating isosorbide-5-mononitrate and propranolol or nadolol administration enhances the reduction in portal pressure and increases the number of patients in whom HVPG decreases by more than 20% of baseline values and below 12 mmHg. Randomized clinical trials (RCT's) do support the concept that combination therapy is more effective than propranolol or nadolol alone, significantly better than sclerotherapy, and probably than endoscopic banding ligation. Therapy may be complemented by the association of spironolactone. The main inconvenience of pharmacological therapy is that there is no non-invasive method available to detect non-responders to treatment. Failures of drug therapy should be managed endoscopically. Failures of endoscopic treatment require 'rescue' by means of TIPS or shunt surgery. Patients with advanced liver failure should be considered for orthotopic liver transplantation, and put into a waiting list if eligible. In the treatment of acute variceal bleeding pharmacological therapy offer the unique advantage of allowing to provide specific therapy immediately after arrival to hospital, or even during transferral to hospital by ambulance, since it does not require sophisticated equipment and highly qualified medical staff. Vasopressin has been abandoned because of its toxicity, although this can be reduced by the combined administration of transdermal nitroglycerin. Terlipressin has longer effects and is more effective and safer than vasopressin alone or in combination with nitroglycerin. It has proved to be effective and to decrease mortality from bleeding in double-blind studies. RCT's have shown that this drug is as effective and safer than emergency sclerotherapy. Therapy should be maintained for five days to prevent early rebleeding. Somatostatin is probably as effective as terlipressin. Octreotide is probably useful after endoscopic therapy but can not be recommended as first line treatment. Endoscopic injection sclerotherapy and endoscopic banding ligation are very effective, but require well trained medical staff. There is an increasing trend for initiating therapy with a pharmacological agent, followed by semi-emergency endoscopic therapy as soon as a well trained endoscopist is available (within 12-24 hours), while maintaining drug therapy for 5 days. Failures of medical therapy may be treated by a second session of endoscopic treatment, but if this fails TIPS of emergency surgery should be done. In high-risk situations, such as bleeding from gastric varices or in patients with advanced liver failure, the decision for TIPS or surgery should be done earlier, after failure of the initial treatment.

Adrenergic beta-Antagonists↗
PubMed2000

Economic outcomes analysis of stenting versus percutaneous transluminal coronary angioplasty for patients with coronary artery disease in Japan.

The purpose of this study was to compare the clinical outcomes and costs of coronary stenting with conventional percutaneous transluminal coronary angioplasty (PTCA) in patients with coronary artery disease (CAD) in Japan. The increasing use of stent implantation in CAD has raised economic concerns for healthcare decision makers. This decision analysis model, which applies to the Japanese healthcare system and uses recent clinical and economic data, demonstrates coronary stenting to be superior to PTCA, both in terms of effectiveness and cost. Although the procedural costs for the stenting group are substantially higher than for PTCA (1,233,412 yen versus 709,295 yen, respectively; p<0.001), the difference in cost between the two procedures (524,117 yen) is already reduced to 299,408 yen by the time of hospital discharge due to procedural complications and associated bail-out treatments avoided during the in-hospital period. The initial incremental cost of stenting is more than recouped by the end of year one, mainly because of savings realized due to avoided repeat revascularization procedures. The cost neutrality (or small cost saving) is maintained over subsequent years. Thus, coronary artery stenting leads to better results as well as cost neutrality after one, two and three years. This highly desirable outcome implies that stenting rather than PTCA alone should be the treatment of choice and dominant strategy in Japan from the viewpoint of both the patient and the healthcare system.

Angioplasty, Balloon, Coronary↗
PubMed1999

Testing non-linearity and directedness of interactions between neural groups in the macaque inferotemporal cortex.

Information processing in the visual cortex depends on complex and context sensitive patterns of interactions between neuronal groups in many different cortical areas. Methods used to date for disentangling this functional connectivity presuppose either linearity or instantaneous interactions, assumptions that are not necessarily valid. In this paper a general framework that encompasses both linear and non-linear modelling of neurophysiological time series data by means of Local Linear Non-linear Autoregressive models (LLNAR) is described. Within this framework a new test for non-linearity of time series and for non-linearity of directedness of neural interactions based on LLNAR is presented. These tests assess the relative goodness of fit of linear versus non-linear models via the bootstrap technique. Additionally, a generalised definition of Granger causality is presented based on LLNAR that is valid for both linear and non-linear systems. Finally, the use of LLNAR for measuring non-linearity and directional influences is illustrated using artificial data, reference data as well as local field potentials (LFPs) from macaque area TE. LFP data is well described by the linear variant of LLNAR. Models of this sort, including lagged values of the preceding 25 to 60 ms, revealed the existence of both uni- and bi-directional influences between recording sites.

Action Potentials↗
PubMed1999

Synthesis of water-soluble phenytoin prodrugs.

The synthesis of novel water-soluble phenytoin derivatives, bearing an ionizable group, and a preliminary study for in vitro blood hydrolysis are reported. The results show that hydrolysis of amino esters 8 is very fast, much more than that of fosphenytoin.

Animals↗
PubMed1999

Do specific EEG frequencies indicate different processes during mental calculation?

EEG recordings during mental calculation and a control task (with presentation of stimuli with similar physical characteristics to the arithmetic symbols) were obtained in 10 subjects. Narrow band analyses of the EEG and distributed sources for each EEG frequency were calculated using variable resolution electromagnetic tomography. Significant differences between the sources for arithmetic and control tasks were observed at 3.9 Hz within Broca's and left parietotemporal cortices, suggesting that this frequency may be related with the production of internal speech, storage and rehearsal of verbal working memory. Differences at 5.46 Hz within the right dorsolateral prefrontal cortex were considered to be associated to sustained attention. The decrease at 12.46 Hz within the left parietal cortex was interpreted as a sign of retrieval of arithmetic facts from long term memory.

Adult↗
PubMed1999

Carvedilol, a new nonselective beta-blocker with intrinsic anti- Alpha1-adrenergic activity, has a greater portal hypotensive effect than propranolol in patients with cirrhosis.

Only some patients show a substantial hepatic venous pressure gradient (HVPG) reduction after propranolol, which makes it desirable to investigate drugs with greater portal hypotensive effect. The aim of this study was to investigate whether carvedilol, a nonselective beta-blocker with anti-alpha1-adrenergic activity, may cause a greater HVPG reduction than propranolol. Thirty-five cirrhotic patients had hemodynamic measurements before and after the random administration of carvedilol (n = 14), propranolol (n = 14), or placebo (n = 7). Carvedilol markedly reduced HVPG, from 19.5 +/- 1.3 to 15.4 +/- 1 mm Hg (P <.0001). This HVPG reduction was greater than after propranolol (-20.4 +/- 2 vs. -12.7 +/- 2%, P <.05). Moreover, carvedilol decreased HVPG greater than 20% of baseline values or to </=12 mm Hg in a greater proportion of patients (64% vs. 14%, P <.05). Both drugs caused similar reductions in hepatic and azygos blood flows, suggesting that the greater HVPG decrease by carvedilol was because of reduced hepatic and portocollateral resistance. Propranolol caused greater reductions in heart rate and cardiac output than carvedilol, whereas carvedilol caused a greater decrease in mean arterial pressure (-23.1 vs. -11%, P <.05). Thus, carvedilol has a greater portal hypotensive effect than propranolol in patients with cirrhosis, suggesting a greater therapeutic potential. However, it causes arterial hypotension, which calls for careful evaluation before its long-term use.

Adrenergic alpha-Antagonists↗
PubMed1999

Impaired mesenteric leukocyte recruitment in experimental portal hypertension in the rat.

Increased incidence of septic complications in human and experimental portal hypertension has been documented. Because development of an inflammatory response is essential in defense against infectious agents, the aim of this study was to assess leukocyte-endothelial cell interactions in an experimental model of portal hypertension. Intravital microscopy studies showed that under baseline conditions, leukocyte rolling, adhesion, and emigration in mesenteric venules were similar in control, sham operated (SO), and partial portal vein ligated (PPVL) rats. Compared with either control or SO rats, PPVL animals exhibited a markedly reduced recruitment of rolling, adherent, and emigrated leukocytes in response to leukotriene B(4) (LTB(4)) stimulation. Similarly, platelet-activating factor (PAF) superfusion, which induced a large increment in leukocyte rolling and adherence in control and SO rats, was without any effect in PPVL animals. Endothelial P-selectin expression in control rats, as measured by the double radio-labeled monoclonal antibody (mAb) technique, was not modified by LTB(4), but significantly increased in response to PAF. PPVL rats had a significantly lower expression of P-selectin after stimulation with PAF. Neutrophils isolated from PPVL rats exhibited increased L-selectin shedding and CD11b up-regulation in response to PAF and LTB(4), compared with neutrophils isolated from SO rats. These observations indicate that portal hypertension is associated with a defective inflammatory response, which is manifested as a decreased recruitment of rolling leukocytes, and subsequently reduced adhesion/emigration. This defect appears to result from a reduced endothelial P-selectin up-regulation and increased L-selectin shedding.

Animals↗
PubMed1999

Wedged hepatic venous pressure adequately reflects portal pressure in hepatitis C virus-related cirrhosis.

Wedged hepatic venous pressure (WHVP) is equivalent to portal venous pressure in patients with alcoholic liver diseases. However, it may underestimate portal pressure in nonalcoholics, which is important because hepatitis C virus (HCV) infection is a frequent cause of chronic liver disease. We investigated the agreement between directly measured portal pressure and WHVP in alcoholic and HCV-related liver diseases. Seventy-one patients with liver disease resulting from HCV infection (n = 32), alcohol (n = 25), or both (n = 14) underwent simultaneous measurements of WHVP (by hepatic vein catheterization) and portal pressure (by direct puncture). In 9 patients, measurements were repeated 20 minutes after acute iv propranolol administration. WHVP showed an excellent agreement with portal pressure in patients with cirrhosis resulting from either HCV, alcohol or both (intraclass correlation coefficient: 0.94, 0.93, and 0.97, respectively; P <.001). A discrepancy of >/=5 mm Hg was observed in 7 cases. WHVP underestimated portal pressure in only 1 case and exceeded portal pressure by >/=5 mm Hg in 6 patients. The WHVP response to propranolol closely and significantly correlated with changes in portal pressure (intraclass correlation coefficient: 0.87; P <.004). The simple and safe measurement of WHVP accurately reflects portal pressure in alcoholic and HCV-related liver disease. This technique also allows us to accurately assess the portal pressure response to propranolol in both alcoholic and HCV-related cirrhosis.

Adult↗
PubMed1999

Th1 predominance and perforin expression in minor salivary glands from patients with primary Sjögren's syndrome.

Objectives of this study were to examine the cytokine and perforin mRNA expression in minor salivary glands from patients with primary Sjögren's syndrome (pSS), searching for possible correlation with clinical parameters and to identify the dominant cytokine pattern in the different groups. Oral mucosa biopsy samples from 42 pSS patients were studied. Total RNA was analysed by normalized RT-PCR using oligo-dT as the RT primer and IL-2, IFN-gamma, IL-12, IL-18, IL-4, IL-10, TGF-beta, TNF-alpha and perforin-specific primers for amplification. Results were analysed taking into account: (1) biopsy grade I to IV (Chisholm's classification); (2) diagnosis of either definite pSS (n=30) or probable pSS (n=12), following the European classification criteria (ECC), and (3) length of disease evolution from the beginning of symptoms to the time of biopsy, using an arbitrary cut-off point of 12 months. This studied showed that Th1-related cytokines (IL-2, IFN-gamma, IL-12, IL-18, TNF-alpha) and perforin were present in most samples. IL-4 (Th2) was totally absent but other Th2 and regulatory cytokines (IL-10, TGF-beta) were detected in the majority of samples. No significant differences were found between definite and probable pSS nor between grades II, III, IV and fibrous tissue biopsies. A statistically significant increase of IL-2 (P=0.012) and IFN-gamma (P=0.019) was observed in samples from patients with longer disease evolution, whereas the two Th1-inducer cytokines IL-12 and IL-18 were equally and highly expressed in all samples. In conclusion, a predominant Th1 pattern of cytokines was observed in all pSS samples, irrespective of biopsy classification. In addition, a significant increase of Th1 cytokine expression frequency was associated with longer disease evolution.

Adult↗
PubMed1999

In vitro synthesis of type I collagen: quantification of carboxyterminal propeptide of procollagen type I versus tritiated proline incorporation.

Radioimmunoassay of the carboxyterminal propeptide of human type I procollagen has been recently introduced to measure in vitro synthesis of type I collagen by osteoblasts and fibroblasts. However, it has not been assessed whether the equivalent results are obtained with this new assay and with tritiated proline incorporation to collagen protein. To this purpose, both methods were used to quantify synthesis of type I collagen in normal human osteoblast cultures to which fetal calf serum and human serum were added in order to stimulate protein synthesis. A positive correlation in the results obtained by both methods was obtained (r = 0.95, P = 0.0001). Given the technical advantages of detection of levels to carboxyterminal propeptide of type I procollagen, we consider that this is the technique of choice for the quantification of in vitro synthesis of type I collagen by normal human osteoblasts.

Aged↗
PubMed1999

Molecular cloning, characterization, and chromosomal localization of the mouse homologue of CD84, a member of the CD2 family of cell surface molecules.

CD84 is a member of the immunoglobulin gene superfamily (IgSF) with two Ig-like domains expressed primarily on B lymphocytes and macrophages. Here we describe the cloning of the mouse homologue of human CD84. Mouse CD84 cDNA clones were isolated from a macrophage library. The nucleotide sequence of mouse CD84 was shown to include an open reading frame encoding a putative 329 amino acid protein composed of a 21 amino acid leader peptide, two extracellular immunoglobulin (Ig)-like domains, a hydrophobic transmembrane region, and an 87 amino acid cytoplasmic domain. Mouse CD84 shares 57.3% amino acid sequence identity (88.7%, considering conservative amino acid substitutions) with the human homologue. Chromosome localization studies mapped the mouse CD84 gene to distal chromosome 1 adjacent to the gene for Ly-9, placing it close to the region where other members of the CD2 IgSF (CD48 and 2B4) have been mapped. Northern blot analysis revealed that the expression of mouse CD84 was predominantly restricted to hematopoietic tissues. Two species of mRNA of 3.6 kilobases (kb) and 1.5 kb were observed. The finding that the pattern of expression was restricted to the hematopoietic system and the conserved sequence of the mouse CD84 homologue suggests that the function of the CD84 glycoprotein may be similar in humans and mice.

Amino Acid Sequence↗
PubMed1999

Prognostic value of early measurements of portal pressure in acute variceal bleeding.

BACKGROUND & AIMS: Variceal bleeding is the most important complication of portal hypertension. However, the relationship between the increase in portal pressure and the outcome of variceal bleeding has not been well defined. METHODS: We measured the hepatic venous pressure gradient (HVPG) of 65 cirrhotic patients with acute variceal hemorrhage, early after admission (20.6 +/- 15.6 hours). RESULTS: Twenty-three patients had a poor evolution (failure to control bleeding or early variceal rebleeding), and 42 had an uneventful evolution. The only variable associated with outcome was the HVPG, which was higher in patients with a poor evolution (23.7 +/- 6.1 vs. 19.2 +/- 3.3 mm Hg; P < 0.0004). This was confirmed by multivariate analysis. HVPG was >/=20 mm Hg in 19 of 23 patients with poor evolution vs. 12 of 42 patients with uneventful evolution (P < 0.0001). An initial HVPG of >/=20 mm Hg was associated with a significantly longer intensive care unit stay (7 +/- 5 vs. 4 +/- 2 days; P < 0.02), longer hospital stay (19 +/- 10 vs. 14 +/- 6 days; P < 0.02), greater transfusion requirements (9.0 +/- 7.7 vs. 4.7 +/- 3.2 UU; P < 0.007), and a worse actuarial probability of survival (1-year mortality, 64% vs. 20%; P < 0.002). CONCLUSIONS: Early measurement of HVPG in cirrhotic patients during acute variceal bleeding provides useful prognostic information on the evolution of the bleeding episode and long-term survival.

Aged↗
PubMed1999

Hyperkinetic circulation and decreased sensitivity to vasoconstrictors following portacaval shunt in the rat. Effects of chronic nitric oxide inhibition.

BACKGROUND/AIMS: This study aimed to investigate: (i) whether the hyperkinetic circulation that develops after portacaval shunt is associated with decreased vascular sensitivity to vasoconstrictors and (ii) the role of nitric oxide on its pathogenesis. METHODS: Portacaval-shunted and sham-operated rats received long-term treatment with the nitric oxide inhibitor L-NAME (osmotic minipump) or its inactive enantiomer D-NAME. Measurements of arterial pressure, cardiac output and superior mesenteric artery blood flow (transit-time flow probe) were done 4 days later in baseline conditions and after increasing doses of methoxamine. Peripheral and superior mesenteric vascular resistance were calculated. RESULTS: Portacaval shunted rats showed a significantly lower peripheral and superior mesenteric vascular resistance and a significant reduction in their response to incremental doses of methoxamine than sham-operated controls. Chronic nitric oxide inhibition attenuated the systemic but not the splanchnic vasodilatation and totally corrected the hyposensitivity to methoxamine of portacaval-shunted rats. However, they still had a significantly lower peripheral and superior mesenteric vascular resistance than sham-operated rats. CONCLUSIONS: This study shows that the splanchnic and systemic hyporesponsiveness to methoxamine observed in portacaval-shunted rats could be explained by an excess of nitric oxide. However, other factors may be involved in maintaining splanchnic and systemic vasodilatation despite NO-inhibition.

Animals↗
PubMed1999

Isosorbide-5-mononitrate in the treatment of pulmonary hypertension associated with portal hypertension.

Pulmonary hypertension is uncommonly associated with portal hypertension. The current approach for the management of pulmonary hypertension involves the use of vasodilators in patients who show vascular responsiveness during an acute challenge. Since the association of portal hypertension with pulmonary hypertension is very seldomly presented, its optimal therapy has not been defined. Moreover, calcium-channel blockers, which are usually used in pulmonary hypertension treatment, may exert a deleterious effect on portal hypertension. Therefore, the search for drugs that may be active under both conditions has important clinical implications. This report presents the case of a patient with portal hypertension-associated pulmonary artery hypertension that was effectively treated with isosorbide-5-mononitrate (Is-5-Mn). The patient had severe portal hypertension (hepatic venous pressure gradient=14.5 mmHg) and pulmonary hypertension (mean pulmonary artery pressure (PAP)=50 mmHg). Acute administration of prostacyclin and nitric oxide elicited a significant reduction in both PAP and pulmonary vascular resistance (PVR), an effect that was also achieved with Is-5-Mn. The patient was treated with 40 mg Is-5-Mn twice daily and a haemodynamic study performed 6 months later showed that the reduction in both PAP and PVR persisted.

Female↗