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Biomedical subjects

R Augustin

Publications and source records attributed to R Augustin.

At least 19 recordsLinked to original sources
PubMed1987

Reduced production of interferon alpha and interferon gamma in leukocyte cultures from patients with active rheumatoid arthritis.

Tests for lymphoproliferation and interferon induction in normal blood donors and patients with rheumatoid arthritis (RA) were performed in a whole-blood assay. Patients with high inflammatory RA showed significantly reduced lymphoproliferation and interferon gamma production after stimulation with phytohemagglutinin (PHA) and concanavalin A (Con A) when compared with patients with low inflammatory activity, or with normal control individuals. Similarly, patients with high and low inflammatory RA exhibited a significantly reduced interferon alpha production after stimulation with Newcastle Disease Virus (NDV) when compared with normal blood donors. Our findings may point to an important immunodeficiency of the circulating lymphocytes of RA patients and may explain some of the in vitro immunoregulatory abnormalities reported in this disease.

Arthritis, Rheumatoid↗
PubMed1987

Plasma catecholamines and alpha- and beta-adrenoceptors in circulating blood cells in patients on continuous ambulatory peritoneal dialysis.

Autonomic system dysfunction could be the cause of postural hypotension seen in patients on continuous ambulatory peritoneal dialysis (CAPD). To verify this hypothesis, we examined the alpha 2- and beta 2-adrenoceptors on blood cells after 1/2 h in the resting supine position with the peritoneal cavity filled for 2-3 h, as well as the response of plasma norepinephrine (NE), heart rate (HR) and mean arterial blood pressure (MAP) to 10 min of standing. Supine free and particularly conjugated NE levels were significantly higher in all uremic patients compared with controls. The postural test induced similar increases of MAP and HR in 8 diabetic, 11 nondiabetic patients and 23 controls, whereas 4 diabetic patients became hypotensive. Orthostasis caused a mean free NE increment of only 0.5 nmol/l in the latter patient group with mean NE responses of 1.45-1.65 nmol/l in the former 3 groups. The densities of platelet alpha 2-adrenoceptors (assessed by [3H] yohimbine binding) and of mononuclear leucocyte (MNL) beta 2-adrenoceptors determined by (-) (125I) iodocyanopindolol binding amounted to 160 +/- 50 and 1600 +/- 520 binding sites/cell, respectively, in controls and were unchanged in patients without postural hypotension. The 4 diabetic patients suffering from postural hypotension showed numerically higher beta 2-receptor numbers (2080 binding sites/cell), significantly increased alpha 2-receptor densities (280 binding sites/cell, p less than 0.05) and significantly increased MNL isoproterenol-stimulated adenylate cyclase activities (38 vs 24 pmol cAMP/10(6) MNL/10 min in controls, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Diabetes Mellitus, Type 1↗
PubMed1985

Golgi and computer morphometric analysis of cortical dendrites in metabolic storage disease.

Golgi and computer morphometric analysis of neuronal dendrites was done on four cases, one each of Tay-Sachs disease, infantile type 2 sialidosis, Hurler's syndrome, and Sanfilippo's syndrome. There were large meganeurites on pyramidal neurons in Tay-Sachs disease, and small ones in Hurler's and Sanfilippo's syndromes. All the meganeurites in these three diseases were predominantly distal to the soma in layer 3, but close to it in layer 5. These findings may be accounted for by different rates of ganglioside accumulation and cortical neuronal morphogenesis. Computer morphometric analysis revealed atrophic or less developed layer 5 dendritic length and branching in Tay-Sachs disease, sialidosis, and Hurler's syndrome compared with tissues from control patients. These dendritic changes may be secondary to ganglioside accumulation or due to abnormal surface membrane production during dendritic development. This study contributes to an understanding of how enzyme deficiency is translated into abnormal cell structure and, presumably, function.

Cerebral Cortex↗
PubMed1985

Proliferation and interferon production in whole blood samples and isolated lymphocyte preparations.

To establish a method for the evaluation of immunological parameters in small blood samples, a whole blood technique was developed for the estimation of mitogen induced cell proliferation and interferon (IFN) production. The results obtained were compared with data using isolated peripheral blood lymphocytes (PBL). Mixtures of heparinized whole blood and culture medium or equal numbers of PBL of healthy volunteers or of patients were cultured with the mitogens concanavalin A, phytohemagglutinin, pokeweed mitogen or the monoclonal antibodies OKT3 and anti-Leu-4. Cell proliferation as measured by 3H-thymidine incorporation and interferon production were found to be of higher magnitude in the whole blood assay. The only situation in which results were similar was pokeweed mitogen induced cell proliferation. Since in the whole blood assay the cell populations are present in their natural distribution, this test system may reflect the in vivo situation better than the test using isolated lymphocytes. Furthermore, our data indicate that whole blood samples may be used clinically for the evaluation of different immune parameters, as data on a limited number of patients with Hodgkin's disease have shown.

Antibodies, Monoclonal↗
PubMed1983

Catecholamines, renin, aldosterone and arterial pressure in patients on chronic hemodialysis treatment.

To assess the interaction between adrenergic activity and blood pressure regulation, plasma catecholamines (CA), plasma renin activity (PRA) and plasma aldosteron (PA) were measured in 66 normal subjects and 18 dialysis patients. Prior to dialysis, blood levels of free norepinephrine (NE), epinephrine (E) and PRA were normal, but total (free and conjugated) CA as well as PA were significantly elevated. There was a spectrum of response during hemodialysis. On an average mean arterial blood pressure (MAP) fell during the first two hours of treatment, concomitantly followed by an increase in mean NE level. Whereas PRA and PA were highest at the end of treatment, mean free NE returned promptly to predialysis values through the late dialysis period. Severe hypotensive episodes during dialysis were associated with a baroreceptor-mediated adrenergic stimulation. These results indicate a qualitatively normal reaction of dialysis patients to volume removal and the importance of the renin-angiotensin-system in maintaining blood pressure during dialysis.

Adolescent↗
PubMed1983

Survival time in cystinosis. A collaborative study.

In a retrospective study the overall survival time of 205 cystinotic patients of six countries was determined. The median survival time was 8.5 years. The median time for 'renal death' (age at death due to uraemia or age at starting renal replacement therapy) was 9.2 years. The youngest patient dying of renal death was 5.2 years. No sex difference in survival time was noticed. Furthermore no difference in survival time was noted between the different countries. The analysis of the overall survival curve indicates no clear differences between the infantile and adolescent types of cystinosis.

Adolescent↗
PubMed1981

[Hyperparathyroidism in hemodialysis patients: studies on parathyroid regulation and classification problems (author's transl)].

In a series of 22 patients undergoing chronic intermittent hemodialysis the response in secretion of parathyroid hormone (PTH) to an acute increase in serum calcium (Ca) concentration was studied. All patients had raised levels of predialysis PTH. Ca concentrations were measured by means of atomic absorption spectrophotometry and PTH concentrations were determined by radioimmunoassay. A close, significant, linear, negative correlation was demonstrated by regression analysis when Ca concentrations were correlated to changes in PTH, expressed as a percentage of the initial predialysis PTH value (100%). This finding supports the assumption that the function of the parathyroid gland at cellular level is similar in all patients, irrespective of very different predialysis PTH concentrations in peripheral blood. The results together with findings in literature were used to describe secondary hyperparathyroidism as a disease which shows typical phases during progression. Some still obscure phenomena of secondary hyperparathyroidism can be explained by discriminating between parathyroid function at a cellular and an organ level. The classification of hyperparathyroidism in regulative and autonomous forms only seems to be applicable when referred to the cellular level.

Calcium↗
PubMed1981

[Bacteriological examinations using the invagination catheter].

Quantitative and qualitative bacteriological studies have been performed on bladder urines taken by two different technics. Bladder urine was first obtained by suprapubic bladder aspiration. Immediately after the puncture another sample of bladder urine was obtained by the "invagination catheter" (only usable in women) transurethrally. In 80 consecutive parallel studies no differences were found in the bacterial counts, and only one difference were found in bacterial type. From the diagnostic point of view, therefore, the two methods were found to be equivalent. In another series of 52 patients catheterization by the invagination catheter was repeated at least 6 hours later without urination in the meantime. The bacteriologic results in the two corresponding specimens were exactly the same in all patients. Contrary to other transurethral methods, no introduction of bacterial agents into the bladder appears to occur with this method.

Bacteriological Techniques↗
PubMed1978

[Quantitative and qualitative bacteriological studies on urine specimens obtained by suprapubic needle aspiration and on midstream-voided samples].

In 398 patients with suspected urinary tract infection, quantitative and qualitative bacteriological studies were conducted in urine samples obtained by suprapubic needle aspiration of the bladder (BPU) and in midstream-voided specimens (MSU) collected immediately following the aspirations. In MSU, bacteria were found in 96.5% of all cases and in BPU in only 38.2%. Of the infected MSU, 63.3% showed mixed infections, while mixed cultures were found in only 11.2% of infected BPU. In 80% of the investigated patients, the MSU contained at least one more type of bacteria than the BPU, thus indicating urethral contamination. Of the patients with bladder bacteriuria, only 74% had bacterial counts of 10(5)/ml or more in the midstream-voided urine. Accordingly, 26% of the urinary tract infections diagnosed by bladder aspiration would not have been recognized on the basis of a single bacterial count in the midstream-voided urine. On the other hand, about 4% of patients with bacterial counts of 10(5)/ml or more in the MSU had a sterile bladder aspirate. In 72.4% of the infected BPU, E. coli was found, followed in frequency by Enterococcus (14.5%). In the infected MSU, however, Enterococcus was more frequent than C. coli (65.6% and 61.7% respectively). Thus, E. coli appears to be the most important etiological species in infections of the bladder and the kidneys, while Enterococcus seems to be the most frequent contaminant during urethral passage. The most frequent bacterial combination in mixed cultures in both BPU and MSU was that of E. coli and Enterococcus.

Enterobacteriaceae↗
PubMed1978

[Acute rise in serum calcitonin concentration during haemodialysis (author's transl)].

Calcium and calcitonin concentrations were measured at the beginning, during and at the end of haemodialysis in 31 unselected patients on chronic intermittent haemodialysis. Blood samples were drawn at the end of dialysis under two different conditions: first, at the end of dialysis during which dialysate calcium concentration was always at 1.75 mmol/1 and secondly, at the end of dialysis with dialysate concentration elevated to 3.0 mmol/1 for the last third of the dialysis period. There was a highly significant increase in serum calcium concentration during haemodialysis, due to transmembranous calcium transfer in all instances. Calcitonin was detectable in free dialysis blood samples of 30 among the 31 patients. In 14 patients there was a significant increase in calcitonin concentration due to increasing calcium concentration during haemodialysis, while in 17 patients there was no change in the calcitonin concentration. Where calcitonin secretion could be stimulated there was a highly significant positive linear correlation, on a percentage basis, between calcium and calcitonin concentrations (r = 0.83, P less than 0.001).

Adult↗
PubMed1977

[Parathyroid function in patients on chronic intermittent hemodialysis (author's transl)].

In three groups of hemodialysis patients the effects of an acute elevation of the serum calcium concentration on the predialysis parathyroid hormone concentration was studied. In the first group (13 patients) the predialysis parathyroid hormone (PTH) concentrations were normal, in the second group (11 patients) slightly elevated, in the third group (5 patients) highly elevated. Calcium was determined by atomic absorption-spectrophotometry, PTH by radioimmunological methods. In hemodialysis patients with normal predialysis PTH concentrations a correlation between the serum calcium concentration and the serum PTH concentration could not be detected. In hemodialysis patients with slightly as well as with highly elevated predialysis PTH concentrations a significant, linear, negative correlation was found between the calcium and the PTH concentration. This correlation, however, was only strong within groups of similar parathyroid hyperfunction. If instead of the absolute PTH concentration calcium is correlated with the changes of the PTH concentration in per cent, a strong correlation between these two parameters can be detected, it is independent of the degree of parathyroid hyperfunction.

Calcium↗