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Biomedical subjects

M Deckert

Publications and source records attributed to M Deckert.

85 records · Page 5Linked to original sources
PubMed1989

Micro-ELISA for the quantitation of human urinary and serum retinol-binding protein.

A highly sensitive enzyme linked immunoadsorbent assay for determining retinol-binding protein in urine and serum is described. Commercially available reagents are used. The standard curve ranges from 1.2-24 micrograms/l, recovery of retinol-binding protein added to urine was 99-102% (n = 10) and dilution of urine was linear. The within-assay coefficient of variation ranged from 1.2-3.1% and the day-to-day coefficient of variation from 9.2-10.5% depending on concentration. The correlation with urinary retinol-binding protein determined by radioimmunoassay was good (n = 90, r = 0.95). In vitro experiments show that retinol-binding protein is stable in urine with pH 5.2.

Enzyme-Linked Immunosorbent Assay↗
PubMed1988

Vascularization of syngenic intracerebral RG2 and F98 rat transplantation tumors. A histochemical and morphometric study by use of ricinus communis agglutinin I.

The vascularization of intracerebral transplantation tumors of the two rat glioma clones RG2 and F98 was studied in various stages of progressive tumor growth by use of biotinylated Ricinus communis agglutinin I (B-RCA I) in avidin-biotin-peroxidase complex (ABC)-histochemistry. The tumors were induced by stereotactic implantation of 1000 glioma cells into the right caudate nucleus of 26 adult CDF-rats and examined after 10, 14, 18, and 21 days following controlled intracardial perfusion of the host animals. Our histochemical results on paraffin sections demonstrate that B-RCA I selectively stains vascular endothelial cells of arteries, veins, and capillaries not only in the normal rat brain but also in the transplantation tumors. Subsequently morphometric measurements of the B-RCA I-stained sections were performed to define the tumor vascularization in quantitative terms. There was an increase in the mean tumor vessel diameters during tumor growth in both transplantation tumor types leading to values about two times above those of the normal rat striatum. On the contrary, the mean vessel density and the mean vessel surface per tumor area were markedly reduced in the late stages of both tumor types when compared to the normal striatum. The RG2 and F98 transplantation tumors differed with regard to the intercapillary distance, which was two times higher in the F98 transplantation tumors than in the RG2 tumors on day 21. In conclusion, B-RCA I is a very sensitive histochemical marker for rat vascular endothelia on paraffin sections. Moreover, this method appears to provide the possibility for qualitative and quantitative study of the development of vasculature in intracerebral transplantation systems including tumors.

Animals↗
PubMed1988

Ultrastructural findings in endomyocardial biopsy of patients with Kearns-Sayre syndrome.

Kearns-Sayre syndrome is clinically defined by progressive external ophthalmoplegia, atypical retinitis pigmentosa and the potential occurrence of complete atrioventricular (AV) block. Right septal endomyocardial biopsy specimens from nine patients (four men and five women with a mean [+/- SD] [corrected] age of 36.3 +/- 14.4 years) with chronic progressive external ophthalmoplegia and mitochondrial skeletal myopathy were studied. Three patients had atypical retinal pigmentation. An atrioventricular or intraventricular conduction defect was observed in five patients. A pacemaker was prophylactically implanted in one patient because of abnormal conduction distal to the His bundle. Ultrastructural investigations revealed mitochondriosis in many heart muscle cells and an increased variability of mitochondrial form and size in all patients. In seven patients, 0.4 to 2.1% of all examined myocytes contained exclusively abnormal mitochondria. Three main types were observed: huge, mainly round mitochondria with concentric cristae; large, round or oval mitochondria with transverse or curved cristae; and small, vacuolated mitochondria. The volume density of myofibrils was reduced (41.9 +/- 11.1 compared with the normal value of 56.5 +/- 2.5 volume density [in percent], p less than 0.01) in these myocytes. Increasing numbers of vacuolated mitochondria correlated significantly with a reduction of myofibrils (r = -0.64, p less than 0.01). The data suggest that the ventricular myocardium of most patients with complete and even incomplete Kearns-Sayre syndrome is affected by disseminated mitochondrial cytopathy.

Adolescent↗
PubMed1988

Glomerular size and charge selectivity in insulin-dependent diabetes mellitus.

The pathogenesis of clinical nephropathy in Type 1 (insulin-dependent) diabetes was investigated by measuring renal fractional clearances of albumin, total IgG, IgG4 and beta 2-microglobulin, four plasma proteins which differ in size and charge. Seventy patients and eleven control subjects were studied. In diabetic patients with normal urinary albumin excretion (less than 30 mg/24 hr), fractional IgG clearance was two to three times higher than in control subjects, whereas fractional clearance of the anionic plasma proteins IgG4 and albumin was similar to that of control subjects. These alterations indicate an increase in anionic pore charge within the glomerular basement membrane concomitant with an increase in either pore size or impairment of tubular reabsorption. Diabetic patients, whose urinary albumin excretion has started to rise (30 to 100 mg/24 hr), had unchanged fractional IgG compared to patients with normal albumin excretion, while fractional IgG4 and albumin clearances were increased three- to fourfold; indicating unchanged glomerular pore size, but a decrease in anionic pore charge. In patients demonstrating urinary albumin excretion of greater than 100 mg/24 hr fractional IgG clearance increased to the same extent as fractional albumin clearance, indicating an increase in large pore area. Fractional beta 2-microglobulin clearances were similar to that of control subjects in the different patient groups indicating unchanged tubular reabsorption of proteins. Thus, the increase in large pore area seen in patients with clinical nephropathy is preceded by loss of anionic charge in the glomerular basement membrane. It is likely that this loss of anionic charge is due to loss of heparan sulphate-proteoglycan.

Adult↗
PubMed1988

Congenital anaplastic astrocytoma with favorable prognosis. Case report.

A large intracranial tumor that caused macrocrania leading to dystocia was demonstrated by prenatal ultrasound examination. After birth, computerized tomography (CT) confirmed the presence of a giant supratentorial tumor with a large cyst. When the infant was 20 days old, the tumor was radically extirpated. Neuropathological examination revealed an astrocytoma with focal signs of anaplasia showing a macrocyst as well as multiple microcysts resulting from hemorrhages into the tumor. Although no adjuvant radio- or chemotherapy was administered, the child had nearly normal psychomotor development without clinical or CT evidence of tumor recurrence, and is now 3 years old.

Astrocytoma↗
PubMed1987

Micro-ELISA for the quantitation of human urinary IgG.

When investigating glomerular changes in the early stages of diabetic renal disease, it is important to be able to estimate low concentrations of urinary immunoglobulins, as well as the albumin/immunoglobulin ratio. For this reason there is a need for highly sensitive and specific routine assays for urinary immunoglobulins. A 'sandwich' enzyme-linked immunoadsorbent assay (ELISA) for the quantitation of urinary immunoglobulin G is described, in which microtest plates are used as the solid phase. The assay is specific, sensitive and simple, and only used commercially available reagents. The assay range was 5-200 micrograms/l. The relative standard deviations within and between assays were 5 and 9%, respectively. Recovery of IgG added to urine was 100-102% (n = 12), and dilution of urine was linear. The assay range allowed for the quantitation of IgG in human urine samples, covering the clinical range from physiological to raised pathological values.

Enzyme-Linked Immunosorbent Assay↗
PubMed1986

Beta 2-microglobulin in urine and serum determined by a micro-ELISA technique.

An enzyme-linked immunoadsorbent assay for the determination of beta 2-microglobulin in serum and urine using microtest plates as solid phase is described. All reagents are commercially available. The assay has a high capacity and it is inexpensive using only 3% of the amounts of antibodies required in a previously described ELISA based on tubes as solid phase.

Diabetes Mellitus, Type 1↗
PubMed1986

[Heart involvement in progressive external ophthalmoplegia (Kearns-Sayre syndrome): electrophysiologic, hemodynamic and morphologic findings].

The Kearns-Sayre syndrome is combined with a progressive external ophthalmoplegia (PEO), retinal pigmentary degeneration and heart block. In some patients, progression of incomplete forms has been described and potentially fatal conduction disturbances may occur. The disease is considered as a systemic mitochondrial disorder. As part of an ongoing prospective study 6 patients (3 female, 3 male; age 32 +/- 9 years) with PEO and typical ultrastructural changes of a mitochondrial myopathy in their skeletal muscle were examined. The ECG disclosed atrio/intraventricular conduction defects in 5 patients: 1 patient had a third degree AV block which was treated by a pacemaker. Another patient had left anterior fascicular block with complete right bundle branch block. In 3 other patients an incomplete right bundle branch block was registered. In 1 patient, His-bundle electrography disclosed a block distal to His by atrial high rate pacing before and after i.v. injection of ajmaline; prophylactically a pacemaker was implanted. The mean HV-interval increased significantly under ajmaline by 44% in patients with sinus rhythm. Hemodynamic studies were normal in 5 patients at rest; only 1 patient was abnormal during exercise. Myocardial biopsy demonstrated mitochondrial abnormalities such as variability in shape and size. In 4 patients concentric cristae mitochondriales were seen. Our results suggest that atrioventricular conduction defects are common in patients with PEO. By means of endomyocardial catheterbiopsy a mitochondrial cardiomyopathy could be detected.

Adolescent↗
PubMed1985

Enzyme immunoassay: an improved determination of urinary albumin in diabetics with incipient nephropathy.

An enzyme linked immunoadsorbent assay for urinary albumin using commercially available reagents is described. The assay range is 2.5-120 micrograms/l. When samples are analysed in two standard dilutions, the assayable albumin concentration range is 2.5-240 mg/l, covering the clinical range from normoalbuminuria to overt clinical nephropathy. Intra-assay variation was 2.1% and interassay variation 8.3%. Recovery of added albumin to urine was 95%-106% and dilution of urine was linear. The correlation to urinary albumin determined by immunodiffusion was excellent (n = 80, r = 0.99). Intraindividual variation of the 24 h urine albumin excretion of different days was high in patients with incipient diabetic nephropathy (51.5%) and was only slightly reduced by taking the variation of creatinine excretion into account (39.5%). No correlation was found between albumin excretion, and HbA1c or urine glucose excretion, indicating that minor metabolic variations are not responsible for the huge intraindividual day-to-day variations of UalbV. The study shows that more than one UalbV measurement must be done before classifying patients into groups with or without incipient diabetic nephropathy.

Adolescent↗
PubMed1980

Comparison of intraperitoneal, intraportal and intravenous insulin infusion.

In order to avoid complications induced by long-term infusion of insulin into the portal vein, we examined the effect of intraperitoneal (ip) insulin infusion on arterial plasma insulin and glucose concentrations in 6 pigs, made diabetic by a constant intravenous (iv) infusion of glucose, epinephrine and propranolol. Insulin was infused by an electromechanical programmable mini-pump (Pharmaject Micro Infusion System, Pharmacia Electronics) as a booster injection of 46 mU highly purified porcine insulin Leo/kg body weight, followed by 3 infusion periods of 30 min each with stepwise decreasing rates of 1.6--0.8 and 0.2 mU/kg/min in a total volume of 192 microliters. Insulin was infused in a peripheral vein, a portal vein and into the peritoneal cavity. A steep rise of arterial plasma insulin was demonstrated followed by a slow and identical decline in the peripheral and portal experiments, whereas only a small increase of plasma insulin was seen in the ip experiment, indicating insufficient absorption of insulin from the peritoneal cavity. The decrease of plasma glucose was identical in the peripheral and portal vein experiments, indicating that insulin infused in the portal vein does not seem to have a higher hypoglycaemic effect, than insulin infused in a peripheral vein. Intraperitoneal insulin infusion seems not to be a practical substitute for iv insulin infusion.

Animals↗
PubMedDate not supplied

Treatment of metastatic colorectal cancer patients with 5-fluorouracil in combination with recombinant subcutaneous human interleukin-2 and alpha-interferon.

We treated 14 patients with progressive metastatic colorectal cancer, using a combination of subcutaneous recombinant human interleukin-2 (4.8 x 10(6) IU/m2 three times daily on days 1 and 22, and twice daily on days 2 and 23, followed by 2.4 x 10(6) IU/m2 twice daily on days 3-5, 8-12, 24-26, and on 5 consecutive days per week, starting day 29), recombinant human interferon-alpha 2a (5.0 x 10(6) U/m2 thrice weekly), and 5-fluorouracil (750 mg/m2 i.v. bolus on days 15-19, and at weekly intervals thereafter, with a 1-week off-therapy interval every 4 weeks). Therapy was continued until disease progression occurred. Four (29%) and 8 (57%) evaluable patients achieved partial remission and stable disease, respectively; median response duration was 5.9 months. Toxicity of this regimen was moderate; the most common side effects were thrombocytopenia, leukopenia, nausea/vomiting, anorexia, malaise and fevers in all patients, along with diarrhea (63%) and mucositis (54%). Less than 10% of patients developed WHO grade IV toxicity; no toxic deaths occurred. Efficacy of this combination was not substantially different from alternative 5-fluorouracil-based regimens.

Adult↗
PubMedDate not supplied

Immunocytochemical detection of P-glycoprotein: initial expression correlates with survival in renal cell carcinoma patients.

We evaluated 28 patients with advanced renal cell carcinoma for the initial expression of P-glycoprotein (MDR1 gene product) employing immunocytochemistry. Tumor specimens were obtained upon primary tumor nephrectomy. In all patients, progression-free survival time following nephrectomy was evaluated and correlated statistically with the staining results. Progression-free survival of patients with no or very few (< 1%) P-glycoprotein-positive tumor cells (n = 8, median survival 27.0 months) was significantly extended (p < 0.04) as compared to patients with 1% or more P-glycoprotein-positive tumor cells (n = 20, median survival 4.0 months). Correlations with histopathological tumor characteristics were insignificant. These results suggest a potential role for P-glycoprotein as a biologic parameter predictive of tumor progression in renal cell carcinoma patients.

ATP Binding Cassette Transporter, Subfamily B, Mem↗