Search PubMed⌕ Search

Biomedical subjects

J Bosch

Publications and source records attributed to J Bosch.

At least 19 recordsLinked to original sources
PubMed1992

[Prognostic value of hepatic clearance of indocyanine green in patients with liver cirrhosis and hemorrhage of esophageal varices].

BACKGROUND: The prognostic value of the quantitative tests of hepatocellular function are not clearly established. Although these tests have significantly correlated with the Child-Pugh classification, it has not been demonstrated that they are better than the same in regards to prognosis. METHODS: The present study was aimed at investigating the prognostic values of hepatic clearance and the intrinsic clearance of indocyanine green (ICG) in 91 cirrhotic patients who had presented hemorrhage due to rupture of the esophageal varices. The clinical and biochemical data, portal pressure determined during suprahepatic vein catheterization, and the clearance, intrinsic clearance, extraction and hepatic blood flow measured during continual infusion of ICG were included in the analysis. All these data were obtained following the stabilization of the patients once over the hemorrhagic episode. RESULTS: The mean survival of the series was 48 months. During follow up (25 +/- 17, interval 1-58 months) 3 of the 32 patients died (9%) of group A of the Child-Pugh classification, 17 of the 52 patients of group B (33%) and 6 of the 7 patients of group C (85%). The Child-Pugh classification was the only variable with an independent predictive value in the multivariate analysis in the Cox model. On exclusion of the 7 patients pertaining to group C, whose survival was clearly inferior to that of the rest of the series, the variables with independent predictive value were, hepatic clearance of less than 240 ml/min and the presence of ascites, while the Child-Pugh classification had no independent predictive value on survival. CONCLUSIONS: The results of the present study indicate that hepatic clearance of ICG and the presence of ascites may have prognostic value in patients of Child-Pugh classification A and B who have recovered from a hemorrhagic episode due to rupture of esophageal varices.

Adult↗
PubMed1992

Frequency domain models of the EEG.

The structure of the normal resting EEG crosspectrum SVV(omega) is analyzed using complex multivariate statistics. Exploratory data analysis with Principal Component Analysis (PCA) is followed by hypothesis testing and computer simulations related to possible neural generators. The SVV(omega) of 211 normal individuals (ages 5 to 97) may be decomposed into two types of processes: the xi process with spatial isotropicity reflecting diffuse, correlated cortical generators with radial symmetry, and processes that seem to be generated by more spatially concentrated, correlated sources. The latter are reflected as spectral peaks such as the process. The eigenvectors of the xi process are the Spherical Harmonic Functions which explains the recurring pattern of maps characteristic of the spatial PCA of qEEG data. A new method for estimating sources in the frequency domain which fits dipoles to the whole crosspectrum is applied to explain the characteristics of the localized sources.

Age Factors↗
PubMed1992

Lymphocyte beta 2-adrenoceptors and plasma catecholamines in patients with cirrhosis.

The hemodynamic response to propranolol in patients with cirrhosis is heterogeneous. In some patients, there is an expected decrease in portal pressure, whereas in others, portal pressure fails to decrease despite adequate beta-blockade. It has been suggested that this lack of response could be related to down-regulation of beta 2-adrenoceptors, promoted by the increased adrenergic activity frequently found in decompensated cirrhosis. The present study investigated this hypothesis by measuring the density and affinity of lymphocyte beta 2-adrenoceptors (L-beta 2-AR), an established index of beta 2-adrenoceptors in target organs, and the plasma levels of norepinephrine and epinephrine in a group of 32 patients with cirrhosis and portal hypertension. The portal pressure response to propranolol administration (0.1 mg/kg + 2 mg/h) was also investigated (n = 27). Patients with cirrhosis had increased norepinephrine levels (605 +/- 360 vs. 224 +/- 110 pg/mL in controls; P less than 0.001), but plasma epinephrine level was not increased (136 +/- 72 vs. 111 +/- 22 pg/mL in controls; NS). There were no differences between cirrhotic patients and controls in the density of L-beta 2-AR (1398 +/- 489 vs. 1278 +/- 356 receptors/cell; NS). Portal pressure decreased greater than 10% in 12 patients (responders) and less than 10% in the remaining 15 (nonresponders). Contrary to previous suggestions, there were no significant differences between responders and nonresponders in relation to the density of L-beta 2-AR (1362 +/- 527 vs. 1487 +/- 419 receptors/cell; NS), to the affinity of these receptors (0.15 +/- 0.27 vs. 0.13 +/- 0.12 nmol/L; NS), to the plasma levels of norepinephrine (661 +/- 508 vs. 621 +/- 256 pg/mL; NS), and to plasma epinephrine concentration (141 +/- 90 vs. 140 +/- 75 pg/mL; NS). These results show that the response of portal pressure to propranolol administration is neither related to the density and affinity of L-beta 2-AR nor to the plasma levels of norepinephrine and epinephrine. Thus, the determination of these parameters cannot substitute measurements of portal pressure to identify those patients with an adequate portal pressure response to propranolol treatment.

Aged↗
PubMed1992

Mineralocorticoid escape in patients with compensated cirrhosis and portal hypertension.

Failure to escape from mineralocorticoids in compensated cirrhosis is considered a major argument supporting the overflow theory of ascites. To assess the frequency and mechanism of mineralocorticoid escape in cirrhosis, 9-alpha-fluorohydrocortisone (0.6 mg/day) was administered to 19 patients with compensated cirrhosis, portal hypertension, and no history of ascites who were able to maintain sodium balance on a 250 mmol Na+ diet. Fifteen patients (78.9%) escaped from mineralocorticoids, while 4 patients (21.1%) did not escape and developed ascites. Patients who did not escape had significantly higher cardiac index (4.97 +/- 0.42 vs 3.46 +/- 0.21 L.min-1.m-2) and lower peripheral vascular resistance (485.9 +/- 37.5 vs. 665.8 +/- 32.9 dyne.s.cm-5/m2) than those who escaped. Hepatic venous pressure gradient was not significantly different. The escape phenomenon was associated with a significant increase in mean arterial pressure, creatinine clearance, and atrial natriuretic factor and suppression of plasma renin activity. All of these parameters showed minimal or no changes in patients who did not escape. These results indicate that failure to escape from mineralocorticoids is uncommon in patients with compensated cirrhosis, is related to an inadequate expansion of effective plasma volume due to the accumulation of ascites, and occurs in patients with marked peripheral arteriolar vasodilation.

Adult↗
PubMed1992

Effects of acute normovolemic anemia on gastric mucosal blood flow in rats: role of nitric oxide.

The present study investigates the effects of acute normovolemic anemia induced by isovolemic hemodilution on gastric mucosal blood flow (GMBF), measured by hydrogen gas clearance, and on the oxygen and hemoglobin content in the gastric mucosa, estimated by reflectance spectrophotometry. GMBF significantly increased after 3 and 6 mL of isovolemic hemodilution (from 50 +/- 5 to 70 +/- 7 and 77 +/- 6 mL.min-1.100 g-1, respectively; P less than 0.05) compared with basal values (50 +/- 5.mL-1.min-1.100 g-1; P less than 0.05). Oxygen content remained unchanged, whereas hemoglobin concentration decreased in parallel with the decrease in hematocrit. In a second set of experiments, the role of endogenous nitric oxide (NO) as a possible mediator of the gastric vascular changes induced by hemodilution was investigated by using the specific inhibitor of NO biosynthesis, NG-monomethyl-L-arginine (L-NMMA). The increase in GMBF induced by 3 mL of isovolemic hemodilution (delta 23 +/- 7 mL.min-1.100 g-1) was attenuated in a dose-related manner with L-NMMA, 6.25 mg/kg IV (delta 15 +/- 4 mL.min-1.100 g-1) or 50 mg/kg IV (delta 5 +/- 2 mL.min-1.100 g-1 g; P less than 0.05). The concurrent administration of L-arginine (the precursor of NO biosynthesis) abolished the effects of L-NMMA on GMBF changes. The current findings show that acute normovolemic anemia causes an increase in GMBF that is dependent on the endogenous formation of NO.

Acute Disease↗
PubMed1992

Increased gastric mucosal perfusion in cirrhotic patients with portal hypertensive gastropathy.

To characterize gastric mucosal perfusion in cirrhotic patients with portal hypertensive gastropathy, 34 cirrhotics with this lesion and 24 noncirrhotics were studied by reflectance spectrophotometry and laser-Doppler flowmetry during endoscopy. A significant correlation was observed between the hemoglobin content of the gastric mucosa, measured by reflectance spectrophotometry, and the serum hemoglobin concentration both in cirrhotics (r = 0.72) and in noncirrhotics (r = 0.87). IHb ratio (hemoglobin content of gastric mucosa divided by blood hemoglobin concentration) was higher in cirrhotics with portal hypertensive gastropathy than in noncirrhotics (P < 0.001), whereas the oxygen content of the gastric mucosa was similar in both groups. This pattern indicates that cirrhotics with portal hypertensive gastropathy have increased gastric perfusion without congestion. Gastric blood flow estimated by laser-Doppler was significantly higher in cirrhotics with portal hypertensive gastropathy than in noncirrhotics (P < 0.001). In cirrhotic patients, gastric areas with cherry red spots showed a significantly higher IHb ratio than areas with a mosaic or scarlatina pattern (P < 0.05). The magnitude of changes in gastric perfusion and the endoscopic severity of portal hypertensive gastropathy had no relationship with the degree of portal hypertension or the azygos blood flow.

Female↗
PubMed1992

Modulation of the hyperdynamic circulation of cirrhotic rats by nitric oxide inhibition.

The effects of NG-monomethyl-L-arginine (L-NMMA), an inhibitor of nitric oxide (NO) biosynthesis on the splanchnic and systemic circulation, were investigated in rats with cirrhosis induced by carbon tetrachloride. Portal hypertension in these rats was accompanied by decreased arterial blood pressure and peripheral vascular resistance as well as by splanchnic vasodilation with increased portal venous inflow and decreased splanchnic resistance. Intravenous bolus administration of L-NMMA (25 mg/kg) significantly increased systemic blood pressure and decreased cardiac output. L-NMMA also significantly increased systemic and splanchnic vascular resistance; whereas blood flow to the stomach, small intestine, colon, pancreas, mesentery, spleen, and kidney was decreased significantly. L-NMMA did not alter the portal pressure or portosystemic shunting in these cirrhotic rats, yet portal vascular resistance increased, suggesting effects on the intrahepatic and collateral circulation. Pretreatment with L-arginine (300 mg/kg) prevented the hemodynamic changes induced by L-NMMA. These findings support the concept that local excess formation of NO contributes to changes in splanchnic circulation associated with portal hypertension in cirrhosis.

Animals↗
PubMed1992

Oral administration of clonidine in patients with alcoholic cirrhosis. Hemodynamic and liver function effects.

The effects of long-term oral clonidine treatment on hepatic and systemic hemodynamics and on quantitative liver function tests were investigated in 15 patients with alcoholic cirrhosis. Clonidine was administered at a mean dose of 0.33 +/- 0.1 mg/day (mean +/- SD) for a mean period of 64 +/- 10 days. Oral clonidine induced a significant reduction in the hepatic venous pressure gradient from 18.8 +/- 3.0 mm Hg to 15.9 +/- 3.4 mm Hg (P less than 0.001), which was the result of an increase in the free hepatic venous pressure from 5.1 +/- 4.2 mm Hg to 8.7 +/- 3.8 mm Hg (P less than 0.05). In 10 of the 15 patients (67%), the reduction in the hepatic venous pressure gradient was greater than 10% of baseline values. Hepatic blood flow did not change significantly after clonidine treatment. Additionally, treatment with clonidine decreased mean arterial pressure by 15.5% +/- 6% (P less than 0.001), heart rate by 17.7% +/- 7% (P less than 0.001), and cardiac output by 14.6% +/- 7% (P less than 0.001). However, systemic vascular resistance did not change significantly. There were no adverse effects on liver function, as shown by the nonsignificant changes in galactose-elimination capacity (149 +/- 59 vs. 170 +/- 58 mg/min), hepatic clearance of indocyanine green (0.19 +/- 0.10 vs. 0.17 +/- 0.07 L/min), and hepatic intrinsic clearance of indocyanine green (0.23 +/- 0.14 vs. 0.21 +/- 0.1 L/min) before and after clonidine treatment, respectively. In none of the patients was the drug withdrawn because of side effects, although 12 subjects complained of dry mouths. This study suggests that in patients with alcoholic cirrhosis, long-term oral clonidine administration achieves a reduction in the hepatic venous pressure gradient without adverse effects on hepatic blood flow and liver function.

Administration, Oral↗
PubMed1992

Hepatic, splanchnic and systemic haemodynamic abnormalities in portal hypertension.

Portal hypertension is characterized by a pathological increase in portal venous pressure that leads to the formation of portosystemic collaterals that divert portal blood to the systemic circulation, bypassing the liver. Increased vascular resistance to portal blood flow is the initiating factor in portal hypertension. Increased resistance along the hepatic and portocollateral circulation is in part modifiable by pharmacological agents. An additional factor is splanchnic vasodilatation with increased portal blood inflow, which contributes to the maintenance and aggravation of the portal hypertension. Endogenous vasodilators are thought to be responsible for the splanchnic hyperaemia of portal hypertension. Vasodilatation is also prominent in the stomach and lungs, and plays an important role in the pathophysiology of portal hypertensive gastropathy and of the hepatopulmonary syndrome. The systemic circulation is markedly hyperkinetic, with reduced arterial pressure and peripheral resistance and increased cardiac output. The plasma volume is expanded due to renal sodium retention. The expanded plasma volume enables the increase in cardiac output, and represents another mechanism contributing to the increase in portal pressure.

Blood Flow Velocity↗
PubMed1992

Effects of inhibiting nitric oxide biosynthesis on the systemic and splanchnic circulation of rats with portal hypertension.

1. The effects of inhibiting endogenous nitric oxide (NO) synthesis with NG-monomethyl-L-arginine (L-NMMA) on the systemic and splanchnic circulation have been investigated in rats with experimental chronic portal hypertension, anaesthetized with ketamine. 2. Portal hypertension was induced by partial portal vein ligation, 2 weeks prior to study. This procedure induced a reduction in systemic arterial blood pressure (MAP), an increase in cardiac output as measured by radiolabelled microspheres, a reduction in peripheral and splanchnic vascular resistance and an increased portal venous inflow (PVI) and portal pressure, as compared to control non-ligated rats. 3. L-NMAA (6.25 and 50 mg kg-1, i.v.) dose-dependently increased MAP, reduced cardiac output and PVI, and increased peripheral and splanchnic vascular resistance. With L-NMMA (50 mg kg-1), PVI and the vascular resistances returned to values comparable to those determined in control non-ligated anaesthetized rats under resting conditions. 4. Porto-collateral resistance was also increased by these doses of L-NMMA, whereas portal pressure was unchanged. The increase in renal blood flow and decrease in renal vascular resistance also seen in portal-hypertensive rats was reversed by L-NMMA (50 mg kg-1). 5. These effects of L-NMMA (50 mg kg-1) were inhibited by prior administration of L-arginine (300 mg kg-1, i.v.). 6. These findings indicate that the chronic hyperdynamic circulatory characteristics following portal vein stenosis can be attenuated by L-NMMA. Thus, the excessive formation of endogenous NO may be implicated in the pathogenesis of the haemodynamic disturbances and splanchnic vasodilatation associated with chronic portal hypertension.

Animals↗
PubMed1992

Portal hypertension in acute liver failure.

Twenty five patients with acute liver failure were measured for hepatic venous pressure gradient as an index of portal pressure during the course of a transjugular liver biopsy. Hepatic venous pressure gradient ranged from 4 to 24.5 mm Hg with a mean of 12.8 (5.3) mm Hg (normal values less than 5 mm Hg). All patients but one had increased portal pressure gradient. Portal hypertension correlated with the degree of architectural distortion of the liver, as suggested by a direct correlation between hepatic venous pressure gradient and the area of reticulin collapse, evaluated by means of a morphometric analysis on Sirius red stained liver slides (r = 0.43, p less than 0.05). Hepatic venous pressure gradient was significantly higher in patients with ascites (15.1 (5) mm Hg, n = 15) or renal failure (14.4 (5.3) mm Hg, n = 16) than in those without (9.3 (3.4) mm Hg and 10.1 (4) mm Hg, respectively; p less than 0.05). Portal hypertension was associated with systemic vasodilation and a hyperkinetic circulatory state, with decreased arterial pressure, and peripheral resistance and increased cardiac output.

Acute Kidney Injury↗
PubMed1992

Limitations of laser-Doppler velocimetry and reflectance spectrophotometry in estimating gastric mucosal blood flow.

This study investigated the accuracy of laser-Doppler flowmetry (LDV) and reflectance spectrophotometry (RS) measurements as an index of blood flow in the gastric mucosa of the rat, in experimental conditions such as pharmacologically induced vasoconstriction, hypoxia, hyperoxia, and acute normovolemic anemia. Hydrogen gas clearance was used as a reference method. After vasopressin infusion, LDV signal and indexes of hemoglobin (IHb) and oxygen (ISO2) content in the gastric mucosa estimated by RS significantly decreased in parallel with the reduction of gastric mucosal blood flow (GMBF). Neither hypoxia (5% O2 administration) nor hyperoxia (100% O2) affected GMBF or LDV signal. However, both IHb and ISO2 significantly decreased or increased after hypoxia or hyperoxia, respectively. Acute normovolemic anemia induced a significant increase in GMBF, while LDV signal and ISO2 remained unchanged. IHb significantly decreased in linear relationship with the decrements in the hematocrit. It is concluded that 1) in pharmacologically induced GMBF changes, LDV and RS correlate with GMBF; 2) when changes in hemoglobin saturation are induced, LDV but not RS reflects GMBF; and 3) in acute normovolemic anemia, neither LDV nor RS reflects changes in GMBF.

Anemia↗
PubMed1992

Double-antibody sandwich enzyme-linked immunosorbent assay and immunoblot analysis used for control of caseous lymphadenitis in goats and sheep.

A double-antibody sandwich ELISA for detection of antibodies directed against the exotoxin of Corynebacterium pseudotuberculosis, the cause of caseous lymphadenitis (CL) in small ruminants, was developed. A concentrated exotoxin was used. For interpretation of ELISA results, these sera were tested: sequentially obtained sera of C pseudotuberculosis-inoculated goats and sheep that were monitored for 68 weeks; sequentially obtained sera from 80 goats of 3 flocks with CL; sera from 652 goats of 7 flocks without CL; sera from 160 sheep of 4 flocks without CL; and 2,265 caprine and 208 ovine sera submitted for diagnostic testing. Data regarding the infection status and history of 10,454 of the 23,302 animals were collected after testing; most of these were goats that had been part of a CL control program. Specificity and sensitivity of the ELISA were nearly 100%. Subsequently, 31,978 animals from which no data on infection status of flocks had been collected were then tested. It was concluded that the ELISA is a useful diagnostic test for CL eradication programs. Sera with doubtful or inconclusive ELISA results were examined by use of immunoblot analysis. Proteins from C pseudotuberculosis culture supernatant were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and blotted onto nitrocellulose. Six proteins with molecular mass of 68, 65, 39, 38, 31, and 29 kDa reacted with sera from goats and sheep with experimentally induced or naturally acquired infection. Immunoblot analysis was valuable in classifying sera with doubtful or inconclusive results by ELISA.

Abscess↗
PubMed1992

[Decrease in the incidence of epidural hematomas surgically treated during coma after a lucid interval. Is this an index of quality of care?].

The level of consciousness prior to surgery has been analyzed in a series of 64 patients suffering epidural hematoma (EDH) who underwent surgery during the period from July 1987 to June 1989. The percentage of cases which underwent surgery in coma after a lucid interval have been compared in different periods of time (1978-80, 1981-82, 1983-84 and July 1987 to June 1989). During the period from July 1987 to June 1989 surgery was performed on: 15 patients (23.5%) in coma from the moment of accident, 8 patients (12.5%) underwent surgery in coma but after a lucid interval and 41 patients (64.1%) were conscious. During the different periods of time the number of patients undergoing surgery in coma after a lucid interval were the following: 1979-80, 9 cases (26.5%); 1981-82, 17 cases (43.6%); 1983-84, 8 cases (20%) and during the last period, 1987-89, 7 cases (15.2%). The difference between the percentage of patients intervened in coma after a lucid interval in the previously referred periods of time was statistically significant (p 0.05).

Coma↗
PubMed1992

Pathophysiology of portal hypertension.

Portal hypertension is characterized by a pathologic increase in portal venous pressure that leads to the formation of an extensive network of portosystemic collaterals that divert a large fraction of portal blood to the systemic circulation, bypassing the liver. Experimental models have improved understanding of the pathophysiology of portal hypertension. It is now clear that an increased vascular resistance to portal blood flow is the initial factor responsible for the increase in portal pressure. This resistance is exerted along the hepatic and portal-collateral circulation and is in part modifiable by pharmacologic agents. In a latter stage, an increased portal venous blood inflow, promoted by splanchnic vasodilation, contributes to maintenance and aggravation of portal hypertension. Humoral vasodilatory agents play an important role in the splanchnic vasodilation. Several vasodilators are likely to be involved, including glucagon, prostacyclin, endotoxins, and nitric oxide. The splanchnic vasodilation is associated with a hyperkinetic systemic circulation, with reduced arterial pressure and peripheral resistance and increased cardiac output. The splanchnic circulation is probably the vascular territory in which the vasodilation is more pronounced. Therefore, splanchnic and systemic vasodilation probably share some pathophysiologic events. An expanded plasma volume is observed in all forms of portal hypertension. Expansion of plasma volume is due to renal sodium retention, which has been shown to precede the increase in cardiac output and can be prevented or reversed by sodium restriction and spironolactone. The expanded blood volume represents another mechanism that contributes to further increases in portal pressure.

Animals↗
PubMed1992

[Intraventricular meningiomas].

Eight cases of surgically intervened intraventricular meningiomas are presented. The patients were six males and 2 females with a mean age of 41.7 years (11-70). The length of symptoms was of several months in 6 (75%) of the cases. The most frequent symptoms observed were cephalea and alterations of the upper functions which were presented in six and four cases, respectively. Papilloedema and involvement of long pathways were the most usual findings observed in neurological examination. Diagnosis was made by computerized tomography and angiography in all the cases. Surgery using a transtemporal approach was carried out in six patients and in the other two a parietal-occipital route was used. Two patients were dead and other two presented bilateral amaurosis. The other patients had good postsurgery.

Adolescent↗