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Biomedical subjects

J Bosch

Publications and source records attributed to J Bosch.

At least 307 records · Page 17Linked to original sources
PubMed1987

Hyperglucagonemia and hyperkinetic circulation after portocaval shunt in the rat.

The study was aimed at investigating whether increased portal venous inflow (PVI) after portocaval shunt (PCS) in the rat is the result of selective splanchnic vasodilatation or whether it is part of a generalized circulatory disturbance. Rats with PCS (n = 9) and sham-operated controls (n = 8) were studied 2 wk after surgery by measuring cardiac output (CO), PVI, and hepatic artery flow (HAF) with radioactive microspheres. Plasma glucagon (GL) was measured by radioimmunoassay. PCS rats had increased CO (46.2 +/- 2.8 vs. 28.2 +/- 1.7 ml X min-1 X 100 g-1, P less than 0.001) and reduced arterial pressure and total peripheral resistance. PVI was markedly increased (7.7 +/- 0.7 vs. 4.3 +/- 0.2 ml X min-1 X 100 g-1, P less than 0.001), but this appeared to be part of a generalized circulatory disturbance, since when PVI is expressed as percent of CO no difference is observed between PCS and sham-operated rats (17.0 +/- 1.5 vs. 15.8 +/- 1.3%, NS), indicating the absence of a preferential splanchnic vasodilatation. GL increased after PCS (548 +/- 130 vs. 156 +/- 23 pg/ml, P less than 0.005), and significant correlations were observed between GL and CO (r = 0.787, P less than 0.001) and between GL and PVI (r = 0.806, P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Sodium fluxes during hemodialysis.

Three sets of experiments were performed to determine the effect of the dialysate sodium concentration on the sodium balance of patients undergoing maintenance hemodialysis. First, patients were treated with three different dialysate bath sodium concentrations: 125-132 mEq/l (n = 7), 135-140 mEq/l (n = 11) and 145-150 mEq/l (n = 6). We demonstrated that the pretreatment plasma sodium concentration was independent of the sodium concentration of the dialysate used. Second, the plasma sodium concentration available for diffusion during the treatment was calculated from the plasma sodium concentration and the plasma proteins. The accuracy of this calculation was demonstrated by comparing the predicted value with the concentration of sodium measured in an ultrafiltrate obtained at minimal filtration fraction. Third, the sodium fluxes using a hypernatremic or hyponatremic dialysate were calculated for 100 ml of plasma going through the dialyzer. At steady state, no significant differences in net sodium fluxes were demonstrated between hyper- and hyponatremic dialysis.

Blood Proteins↗
PubMed1987

Gas exchange and pulmonary vascular reactivity in patients with liver cirrhosis.

To investigate the mechanisms underlying abnormal gas exchange in liver cirrhosis, 15 patients were studied while breathing room air, 11% O2, and 100% O2 in random sequence. Under basal conditions, patients showed mild reductions from normal in systemic and pulmonary vascular resistance, normal PaO2 (mean, 92.5 +/- 2.5 mm Hg), mild hypocapnia (mean, 34 +/- 0.7 mm Hg), and a slightly right-shifted oxyhemoglobin dissociation curve (P50, 27.2 +/- 0.4 mm Hg; 2,3-DPG, 13.1 +/- 0.6 mumol/g). Using the multiple insert gas elimination technique, we found mild to moderate ventilation-perfusion (VA/Q) inequality with a mean of 5% (range, 0 to 20%) of cardiac output (QT) perfusing low VA/Q ratio (less than 0.1) areas but no shunt. Breathing 11% O2, there were significant increases in QT, pulmonary artery pressure, and vascular resistance, whereas no changes occurred in VA/Q distribution, and there was no evidence for alveolar-endcapillary diffusion limitation for O2. In contrast, after 100% O2 shunt developed and VA/Q relationships worsened without significant hemodynamic changes. Furthermore, patients with cutaneous spider nevi (n = 8) showed more hepatocellular dysfunction (lower prothrombin values), lower systemic and pulmonary vascular resistance, less hypoxic pulmonary vasoconstriction (HPV), lower PaO2, and more VA/Q mismatch than did those without spiders. Our results confirm, therefore, that HPV is not fully abolished, as previously described, in hepatic cirrhosis. However, those patients with more advanced hepatic disease exhibit inadequate pulmonary vascular tone, which increases VA/Q inequality and lowers PaO2.

Adult↗
PubMed1987

Increased plasma volume in two models of portal hypertension in the rat: cirrhosis of the liver and partial portal vein ligation.

Portal hypertension has been studied in the rat to see if it is associated to altered blood volume composition, as it has been shown in other species. Plasma volume was measured by isotope dilution using 99mTc labelled albumin in three groups of male Sprague-Dawley rats: normal rats (controls), partially ligated portal vein rats and rats with Cl4C induced cirrhosis. Plasma volume was significantly higher in rats with portal hypertension due to partially ligated portal vein and cirrhosis than in control animals. Similarly, the calculated blood volume was also significantly higher in the portal hypertensive animals than in control group. Portal hypertension in the rat, therefore, has been demonstrated to be associated to a marked hypervolemia and this finding should be taken into consideration in haemodynamic and pharmacokinetic studies in portal hypertensive rat models.

Animals↗
PubMed1987

Relative hyperphosphaturia in diabetic chronic renal failure: a protective factor of hyperparathyroidism.

Relative low serum levels of parathormone (PTH) and low incidence of secondary hyperparathyroidism have been reported in diabetic uremic patients. The pathogenesis of this reported resistance to uremic secondary hyperparathyroidism in diabetes remains controversial. We have measured the serum C-terminal parathormone (C-PTH) renal phosphorus threshold (TmPO4) and nephrogenous cyclic AMP (N-cCAMP), in 2-hour urine collection in 22 patients with diabetic nephropathy with moderate chronic renal failure and in 27 controls with similar creatinine clearance values (18.16 +/- 9.14 and and 19.1 +/- 8.47 ml/min). In spite of the lower levels of serum C-PTH (1.07 +/- 0.43 ng/ml) diabetic patients exhibited an increased phosphaturia (TmPO4: 1.97 +/- 0.9 mg/100 ml GFR) when compared with the control group (C-PTH: 2.01 +/- 1.17 mg/ml, and TmPO4: 2.5 +/- 0.7 ml GFR). When the C-PTH values were plotted against the logarithm of creatinine clearance values, both groups showed a significant linear relationship reflecting the progressive increase in PTH when GFR fell. This progressive parathyroid stimulus was also present in diabetic patients but in a lower intensity. We believe that increased phosphaturia in diabetics with moderate chronic renal failure may be a major factor in precluding the appearance of secondary hyperparathyroidism in these patients once they reach the dialysis and transplantation programs.

Diabetic Nephropathies↗
PubMed1986

Double-lumen, silicone rubber, indwelling venous catheters. A new modality for angioaccess.

This report presents our experience using double-lumen, silicone rubber, indwelling central venous catheters with a subcutaneous Dacron cuff as access for hemodialysis. Twenty-seven catheters were placed in 27 patients through venous cutdowns. A 10-cm subcutaneous tunnel was created leaving the Dacron cuff 2 cm from the external exit. Sixteen Raaf catheters (lumen diameter [LD], 1 mm), three double-lumen Hickman catheters (LD, 1.6 mm) and eight HemoCath catheters (LD, 2 mm) were used. The tip of the catheter was positioned fluoroscopically in either the superior vena cava or the right atrium. One hundred fifty-nine treatments were done with the Raaf catheters (mean blood flow [MBF], 188.1 +/- 26.4 mL/min); two of these catheters became obstructed and could not be used further. Three double-lumen Hickman catheters were used in 12 hemodialysis treatments (MBF, 216.3 +/- 27.1 mL/min). One hundred fifty-five treatments were done using the HemoCath catheters (MBF, 236.7 +/- 5.5 mL/min). The degree of recirculation of these catheters was 8.56% +/- 4.34%. The major advantages of this modality include simplicity of introduction, lack of serious complications, no sacrifice of major arteries, no need for venipuncture, and potential use in either short- or long-term hemodialysis.

Adult↗
PubMed1986

Long term follow-up of 100 patients with portal hypertension treated by a modified splenorenal shunt.

One hundred consecutive Child's A or B patients with portal hypertension who survived the index episode of variceal bleeding were electively treated by a distal splenorenal shunt modified by a retroperitoneal approach. The operative mortality of the whole series was 11 per cent, but fell from 16 per cent in the first 50 patients to 6 per cent in the second half of the series. The median survival probability (68 months) and the 5 year survival rate (52 per cent) of Child's A patients differed significantly from those of Child's B patients (8 months and 15 per cent respectively; P less than 0.001). The probabilities of freedom from rebleeding and hepatic encephalopathy at 5 years were also significantly greater in Child's A patients (70 per cent and 70 per cent respectively) than Child's B patients (25 per cent and 30 per cent respectively). These results suggest that the modified distal splenorenal shunt is an effective and relatively safe procedure for the elective treatment of variceal bleeding in Child-Campbell 'A' patients but that patients in group B should be considered for other forms of therapy.

Adolescent↗
PubMed1986

In-vitro activity of ciprofloxacin, ceftriaxone and five other antimicrobial agents against 95 strains of Brucella melitensis.

We studied the in-vitro activity of seven antibiotics against 95 strains of Brucella melitensis isolated in blood cultures of 95 patients with brucellosis. The minimum inhibitory concentration (MIC) was measured by the agar dilution method. All strains of B. melitensis were inhibited by doxycycline at 0.25 mg/l, tetracycline at 0.5 mg/l, ciprofloxacin at 0.5 mg/l, streptomycin at 1 mg/l, ceftriaxone at 1 mg/l, rifampicin at 4 mg/l and by co-trimoxazole at 0.5/9.5 mg/l. We did not find strains resistant to any of the antibiotics studied. All antibiotics, including ciprofloxacin and ceftriaxone, showed a good in-vitro activity against B. melitensis.

Anti-Bacterial Agents↗
PubMed1986

Relevance of in vitro antimicrobial susceptibility of Brucella melitensis to relapse rate in human brucellosis.

The in vitro susceptibility of Brucella melitensis was examined vis-a-vis the clinical outcome in 75 patients with brucellosis. The initial MICs for Brucella isolates from patients who relapsed and from those who did not were similar. Furthermore, the MICs for isolates from patients whose infections relapsed were no different from those for original isolates. Our results clearly showed that neither initial nor subsequent antibiotic susceptibility plays a role in the likelihood of relapse of patients with brucellosis.

Adolescent↗
PubMed1985

Effects of prostaglandin inhibition on systemic and hepatic hemodynamics in patients with cirrhosis of the liver.

The role of prostaglandins in the pathogenesis of the circulatory abnormalities of cirrhosis was investigated by studying the effects of prostaglandin inhibition with indomethacin (50 mg/8 h for 24 h) on the systemic and splanchnic hemodynamics in 13 patients with cirrhosis of the liver. Indomethacin administration significantly reduced cardiac output (from 7.44 +/- 0.7 to 6.78 +/- 0.7 L/min, p less than 0.05) and increased peripheral vascular resistance (from 990 +/- 104 to 1155 +/- 140 dyn X s X cm-5, p less than 0.05). Arterial pressure was not modified. These changes in systemic hemodynamics were associated with a significant reduction in hepatic blood flow (from 1.88 +/- 0.43 to 1.48 +/- 0.3 L/min, p less than 0.05) and with a slight decrease of portal pressure (from 18.8 +/- 1.3 to 17.5 +/- 1.4 mmHg, p less than 0.05). These results suggest that endogenous prostaglandins contribute to the increased cardiac output and diminished vascular resistance observed in cirrhosis of the liver. In addition, by promoting splanchnic vasodilation, prostaglandins may contribute to increased portal pressure in these patients.

Adult↗
PubMed1985

Measurement of azygos venous blood flow in the evaluation of portal hypertension in patients with cirrhosis. Clinical and haemodynamic correlations in 100 patients.

Blood flow in the azygos vein, an index of blood flow through gastro-oesophageal collaterals, was measured by continuous thermal dilution in 100 patients with cirrhosis. Azygos blood flow was directly related to portal pressure (r = 0.54, P less than 0.001). Patients with portal hypertension had very high azygos blood flow (692 +/- 32 ml/min) in comparison with controls (n = 11, 174 +/- 29 ml/min). Patients with previous oesophageal bleeding had similar azygos blood flow as those without, but azygos blood flow was significantly greater in patients with massive or recurrent bleeding than in those with less severe haemorrhage, suggesting that the magnitude of collateral flow may influence the course of variceal bleeding. Patients with grade III varices had higher azygos blood flow than those with grades II or I. In addition, both oesophageal tamponade and vasopressin infusion, procedures of known value in variceal bleeding, markedly reduced azygos blood flow (-40% and -25%, respectively). Measurement of azygos blood flow allows evaluation of haemodynamic changes in the oesophageal collaterals of patients with portal hypertension, and provides useful information on the effect of therapeutic procedures aimed at arresting or preventing variceal haemorrhage.

Azygos Vein↗
PubMed1985

Low incidence of hyperparathyroidism in diabetic renal failure.

The first study compared two groups on dialysis: 25 patients with diabetes mellitus and 25 matched non-diabetic patients, in relation to the presence of signs of hyperparathyroidism, to assess the reported low incidence of hyperparathyroidism in these patients. The diabetic group showed significantly lower values of PTH, Alk phosphatase, percentage of patients requiring vitamin D treatment, and less evidence of hyperparathyroidism on X-ray and in bone histomorphometry. In the second study 16 patients with chronic renal failure due to diabetic nephropathy were compared to 27 patients with the same degree of renal failure of other origin, the diabetic nephropathy group showed no increase in PTH, with falling creatinine clearance. Despite this low PTH, the phosphaturia was higher in the diabetic nephropathy group (Tm PO4/C Cr: 1.94 +/- 0.43 vs 2.5 +/- 0.68). In conclusion, patients with diabetes mellitus are less prone to develop hyperparathyroidism in progressive renal failure. This could be due to a relative increase in phosphaturia during declining function.

Diabetic Nephropathies↗
PubMed1985

N tau-methylhistidine: inhibitor of hepatic protein synthesis?

Protein synthesis in isolated perfused rat livers has been studied. Aminoacids at physiological rat concentration (U-14C)-Leucine 0.065 muCi/ml and N Tau-Methylhistidine His (Tau-Me) were added to the perfusion medium. His (Tau-Me) from 0.01 to 2.0 mM causes a reduction between 40-60% in the rate of secreted proteins, independently of the His (Tau-Me) concentration.

Animals↗