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A Bock

Publications and source records attributed to A Bock.

71 records · Page 4Linked to original sources
PubMed1989

Comparative effects of haemodialysis and haemofiltration on plasma atrial natriuretic peptide.

The effects of 4 h haemodialysis (15 patients) or 4 h haemofiltration (five patients) on plasma concentrations of atrial natriuretic peptide (ANP) were compared by means of a sensitive radioreceptor binding assay, and related to accompanying changes in body weight, blood pressure and plasma renin activity. Before dialysis, plasma ANP concentrations were considerably elevated: haemodialysis group 10-484 pmol/l (mean 156 pmol/l); haemofiltration group 72-320 pmol/l (mean 170 pmol/l). Although plasma concentrations of ANP fell markedly with treatment in both groups: post-haemodialysis 2-187 pmol/l (mean 67 pmol/l); post-haemofiltration 47-135 pmol/l (mean 79 pmol/l), after treatment it remained above the normal range in 14 of the 20 patients. Pretreatment plasma ANP was related to systolic blood pressure (r = 0.459; P less than 0.05) but bore no relationship to mean or diastolic blood pressure, or plasma renin activity. The fall in plasma ANP concentration during treatment correlated with the postural blood pressure drop after dialysis (r = 0.505; P less than 0.05), but was unrelated to changes in weight or plasma renin activity with haemodialysis or haemofiltration. Plasma ANP concentrations rose rapidly again in the 60 min after dialysis treatment, without change in body weight. These results show that high levels of biologically active ANP circulate in end-stage renal disease. The fact that these are not reduced to normal by haemodialysis or haemofiltration, despite restoration to normovolaemic or hypovolaemic state, suggests that the increased levels of ANP in end-stage renal failure are due to both hypervolaemia and other factors, which may include occult cardiac dysfunction and loss of renal clearance.

Adult↗
PubMed1989

Influence of flunarizine on postischemic flow and energy metabolism in the isolated rat brain.

Isolated perfused rat brains were subjected to complete ischemia. Reperfusion was started 10 min after the negative DC-shift. In control brains, recovery of flow was retarded and, after 10 min of reperfusion, a delayed hypoperfusion developed. In flunarizine-treated brains, recovery of flow was considerably steeper, complete and without reduction during the further course of reperfusion. Additionally, restoration of energy metabolism and mitochondrial function was significantly improved. The effect on the energetic state of the brains was at least partly independent of the improvement of flow. This could be concluded from experiments in which reperfusion was commenced simultaneously with DC-negativation. In these experiments, flow recovery was prompt and complete in control as well as in treated brains. Nevertheless, treated brains exhibited after reperfusion significantly better ratios of ATP to ADP and normalized levels of lactate and succinate.

Animals↗
PubMed1987

Vasopressin is increased in mineralocorticoid-induced blood pressure increase in man.

Vasopressin has been studied intensively in DOCA-salt rats and seems to play an important role in this model of hypertension. In the present study we investigated plasma vasopressin in seven normotensive young volunteers during the early phase of mineralocorticoid-induced hypertension. We administered 0.8 mg/day fludrocortisone for 1 week. Body weight, blood pressure, plasma vasopressin, plasma osmolality and electrolytes, as well as plasma renin activity, were evaluated on days 0, 3 and 7. Blood pressure increased significantly from 117/67 to 121/76 mmHg (P less than 0.05) within 1 week, while plasma osmolality remained unaltered at 284 +/- 3 mOsmol/l. Plasma vasopressin (0.45 +/- 0.1 pg/ml) was increased after 3 days (0.68 +/- 0.5 pg/ml) and rose further to 1.53 +/- 0.27 pg/ml after 1 week (P less than 0.05). Changes in plasma vasopressin concentration were not correlated with alterations in blood pressure. Our results show an increase in plasma vasopressin in the early phase of mineralocorticoid-induced hypertension in man. However, the observed increase is moderate and does not seem to explain the increase in blood pressure alone, but could contribute to the blood pressure increase during mineralocorticoid treatment.

Adult↗
PubMed1982

Lack of cytotoxicity of ticrynafen in primary cultures of rat liver cells.

Primary cultures of hepatocytes obtained from neonatal Sprague-Dawley rats were grown in arginine-deficient, ornithine-supplemented medium to inhibit fibroblastic overgrowth and to selectively isolate relatively pure cultures of parenchymal hepatocytes. This system of primary hepatocytes was used to study the potential cytotoxicity of ticrynafen by measuring cytoplasmic enzyme leakage, cell viability,, and total protein per culture dish. Hepatic cultures were treated with the drug in concentrations ranging from 10(-3)M to 10(-6)M and for durations from 2 to 8 h. The results of the study indicate that ticrynafen was minimally toxic to the hepatocytes.

Animals↗
PubMed1976

[Simultaneous study of the placental, myometrial and cervical circulations (indium 113 and anemometric thermometry). 2. Effect of xanthinol nicotinate].

The authors have studied the action of nicotinate of xantinol on the placental, myometrial and cervical circulations using an isotope technique (Indium 113) and anemometric thermometry. They show that this product in every case increases the flow through the cervix and has little action on the flow through the placenta, except that in rare cases it lessens it. The action on the myometrial circulation varies from woman to woman. There is a significant negative statistical correlation between variation in the circulation through the cervix and the placenta.

Adult↗
PubMedDate not supplied

Delayed graft function: risk factors, consequences and parameters affecting outcome-results from MOST, A Multinational Observational Study.

BACKGROUND: Delayed graft function (DGF) is a common complication after renal transplantation, and may affect graft function. The aim of this analysis was to evaluate risk factors for DGF, as well as parameters and events influencing graft function after DGF. We analyzed data collected in an ongoing international, prospective; observational study, the Neoral-MOST (Multinational Observational Study in renal Transplantation), and included in the analysis all patients with cadaveric kidney transplants for whom renal function at 1 year posttransplantation was documented (N = 8950). Logistic regression was used to evaluate the risk factors for DGF occurrence, and multifactorial analysis of variance (ANCOVA) to assess the relevance of different factors for GFR at 1 year. RESULTS: Higher donor age, longer CIT, male recipients, Caucasian recipients, high recipients body mass index, and PRA were all associated with a higher risk for DGF. Renal function of former DGF kidneys at 1 year was lower in kidneys of elder donors, or which had experienced rejection or CMV infection. Variations of the maintenance regimen at 1 year posttransplantation were not associated with better graft function. Multifactorial analysis showed donor age and acute rejection as significant independent factors. CONCLUSIONS: Most factors increasing the risk for DGF or having a negative impact on renal function at 1 year in grafts with DGF are predetermined. Additional posttransplant damage by acute rejection was associated with further reductions in GFR. Preventing acute rejection is an important step in achieving optimal function of DGF grafts.

Adult↗
PubMedDate not supplied

Impact of mycophenolate mofetil dose posttransplantation on 12-month renal function: analysis of the MOST database.

INTRODUCTION: Mycophenolate mofetil (MMF) has greatly reduced the risk of acute rejection episodes (ARE) after renal transplantation, but dose reductions/withdrawals could jeopardize long-term results. METHODS: The MOST database of "de novo" patients treated with MMF at month 1 and functioning grafts at month 12 were divided into 2 groups: groups 1, 2 g MMF at month 1 and month 12; and group 2, 2 g MMF at month 1 but MMF <2 g at month 12 to evaluate renal function glonerular filtration rate (GFR). RESULTS: In this study, 1136 patients were receiving 2 g MMF at month 1. On month 12, 645 were on 2 g (56.8%, group 1) and 431 were on <2 g (43.2%, group 2). Group 1 included younger recipients of younger donors with fewer patients with delayed graft function (DGF). Group 1 showed more ARE during month 1 and more patients who received induction. Mean Neoral daily doses at month 1/month 12 were 5.3/3.0 and 5.3/3.1 mg/kg in group 1 and group 2, respectively (P = .05 at month 12). GFR in group 1 and group 2 were 59.06 (CI 57.10-60.60) and 53.81 (CI 52-55.7) at month 1 (P < .001); 63.7 (CI 62.1-65.30) and 55.9 (CI 54.1-57.7) mL/min*1.73 m(2) at month 12 (P < .001). The mean increases in GFR between month 1 and month 12 were 4.64 and 1.94 mL/min*1.73 m(2), respectively (P < .05). A multivariate analysis also included 795 patients from the "maintenance" patient database with retrospective detailed information. The following parameters were highly predictive for good renal function at month 12: donor age younger than 60 years, recipient age younger than 60 years, immediate graft function, 12-month MMF dose = 2 g, absence of CMV infection, and 12-month Neoral dose <3 mg/kg/d. CONCLUSIONS: Maintenance of MMF dose at 2 g/d during the first year appears to facilitate the attainment of optimal renal function at 12-months after kidney transplantation.

Analysis of Variance↗
PubMedDate not supplied

Endotoxins and allergy: lessons from the murine model.

Exposure early in life to organic dusts containing immunomodulatory components such as endotoxins and immunizing components such as aeroallergens may greatly influence whether subsequent encounters with allergens lead rather to sensitization or unresponsiveness. We investigated the effects of endotoxin in the context of allergen-mediated immune responses in a murine model of allergen sensitization. Systemic sensitization with ovalbumin induced high serum levels of allergen-specific IgE, predominant Th2-type cytokine production, eosinophilic airway inflammation and in vivo airway hyperreactivity. Endotoxins were either applied systemically prior to sensitization, or via the airways prior to airway challenges, or by repeated inhalation during the first weeks of life prior to subsequent sensitization. Different effects of endotoxins on allergen-induced immune responses may be attributed to differences in dosing, route of application, time relationship with allergen sensitization and the concurrent exposure to endotoxin and allergen. The results of these studies may help to define the effects of endotoxin on allergen-mediated immune reactions and to further delineate the important interrelationships between environment and disease development. Finally, this may lead to new strategies in the prevention and treatment of allergic diseases.

Allergens↗
PubMedDate not supplied

Reduced postprandial hyperglycemia after subcutaneous injection of a somatostatin-analogue (SMS 201-995) in insulin-dependent diabetes mellitus.

The effect of a new octapeptide analogue of somatostatin (SMS 201-995) on blood glucose and gut hormone levels was studied in 10 C-peptide-negative, insulin-dependent diabetic (IDDM) subjects. On separate days, either 50 or 100 micrograms SMS or placebo was s.c. injected simultaneously with an identical insulin dose 30 min before a mixed meal. Postprandial blood glucose decreased after 100 micrograms SMS s.c. within 30 min from 8.9 +/- 0.7 to 7.8 +/- 0.6 mmol/L (P less than 0.001) and remained at similar levels during 180 min. In contrast, postprandial blood glucose concentration increased after placebo from 9.9 +/- 0.8 to 13.8 +/- 0.9 mmol/L (SMS versus placebo P less than 0.001). Plasma glucagon decreased rapidly after SMS to the limit of detection (P less than 0.001) and remained lowered during 180 min; in contrast, glucagon levels increased after the meal during the placebo study (SMS versus placebo P less than 0.001). Plasma growth hormone concentrations were significantly lower after SMS than after placebo (P less than 0.05). SMS abolished completely the postprandial increase in plasma gastrin and pancreatic polypeptide (PP) concentrations. Plasma free fatty acid (FFA) and triglyceride concentrations decreased after SMS, reaching significantly lower levels than after placebo (P less than 0.05 and P less than 0.01), respectively). Plasma SMS concentration increased rapidly after s.c. administration of SMS; its appearance preceded that of plasma free insulin after s.c. insulin injection. Fifty micrograms SMS was similarly effective as 100 micrograms in decreasing blood glucose, triglycerides, glucagon, and gut hormone concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

[Simultaneous study of the placental, myometrial and cervical circulations (indium 113 and anemometric thermometry). 3). Double blind study of the action of intravenous ritodrine during normal pregnancy].

The authors measure the changes in placental and myometrial blood flow using an isotope technique with Indium 113. They calculate an index of the variation in placental blood flow (I.V. D.P.) and an index of variation of myomoetfrial blood flow (I.V.D.M.) after injecting Ritodrine or a placebo between the 28th and the 36th week of pregnancy. This study was carried out in 26 normal women. At the same time using Brotanek's technique changes in the cervical blood flow were registered. No change in the placental, myometrial or cervical blood flows were noted while Ritodrine was being transfused intravenously.

Adult↗