PubMed Health⌕ Search

Biomedical subjects

N Zöllner

Publications and source records attributed to N Zöllner.

At least 73 records · Page 4Linked to original sources

Familial defective apolipoprotein B-100: haplotype analysis of the arginine(3500)----glutamine mutation.

Familial defective apolipoprotein B-100 (FDB) is a recently identified, dominantly inherited genetic disorder, which leads to an increased serum level of low density lipoprotein (LDL) cholesterol with reduced affinity for the LDL receptor. It is postulated that this disorder results from a G to A mutation at nucleotide 10,708 in exon 26 of the apo B gene creating a substitution of glutamine for arginine in the codon for amino acid 3500. To investigate whether recurrent mutation has contributed to the high frequency of FDB, we have conducted a haplotype analysis in previously reported and newly detected FDB heterozygotes in Germany. 5 FDB families and 6 unrelated FDB heterozygotes were genotypes at 4 polymorphic sites in the 3' end of the apo B gene. These sites consisted of the diallelic markers XbaI, MspI, EcoRI and the hypervariable region (3'HVR). In 5 FDB families and 1 unrelated FDB heterozygote the arginine(3500)----glutamine mutation could be unambiguously assigned to the haplotype XbaI-/MspI+/EcoRI-/3'HVR48, in the other 5 FDB unrelated heterozygotes this finding was consistent with the combination of the genotype. The existence of the arginine(3500)----glutamine mutation on the same and supposedly rare allele suggests that the mutant alleles are identical by descent in our population. The fact that the same mutant allele was identified in North America and Austria suggests a common European origin of the arginine(3500)----glutamine mutation.

Adult↗

Use of DNA haplotype analysis in diagnosis of familial hypercholesterolaemia in 31 German families.

In the majority of patients, familial hypercholesterolaemia (FH) is caused by different mutations affecting the well defined low density lipoprotein receptor (LDLR) gene. However, 3% of patients in Munich with a clinical diagnosis of FH have a particular mutation in the apolipoprotein B gene causing familial defective apolipoprotein B-100 (FDB). To date none of the LDLR mutations causing FH in German patients has been identified and it is therefore not yet possible to use DNA technology for direct diagnosis. However, indirect molecular diagnosis based on genetic linkage of common restriction fragment length polymorphisms (RFLPs) of the LDLR gene can be used for diagnosis in family studies. Patients with FDB were excluded from this study. Genotypes and haplotypes of four RFLPs (StuI, ApalI 5', PvuII, and NcoI) were determined in a total of 164 independent alleles from 31 pedigrees that included 222 subjects. Allele frequencies and four RFLP haplotype distribution did not differ significantly from those reported in other populations. The applicability of DNA diagnosis in our lipid clinic is comparable with the estimation from calculations on frequencies and heterozygosities of RFLPs, as predicted using these four RFLPs before. On the basis of cosegregation of haplotypes and normo- or hypercholesterolaemia in one or more sibs or offspring, defective and normal LDLR gene alleles could be distinguished in 42 of 58 heterozygous FH patients who were heterozygous for at least one RFLP. In 97 of 134 (72%) children of these 42 subjects, diagnosis of FH could be carried out unambiguously.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Effects of oral ribose on muscle metabolism during bicycle ergometer in AMPD-deficient patients.

Three patients with AMP deaminase deficiency (AMPD deficiency) performed exercise on a bicycle ergometer with increasing work load without and with administration of ribose (3 g p.o. every 10 min, beginning 1 h before exercise until the end). The patients performed exercise until heart rate was 200 minus age. Maximum capacity was not increased by administration of ribose, but postexertional muscle stiffness and cramps disappeared almost completely in 2 of 3 AMPD-deficient patients. Plasma concentrations of lactate and inosine were increased in AMPD-deficient patients after oral administration of ribose. Our data suggest that ribose may both serve as an energy source and enhance the de novo synthesis of purine nucleotides.

AMP Deaminase↗

Pleural effusions in acute mononucleosis.

A case of acute infectious mononucleosis with pleural effusions as rare complication is reported. This complication is detectable by ultrasonographic examination, often performed in the follow-up of affections of liver and spleen in infectious mononucleosis. It should also be regarded in the differential diagnosis of pleural effusions.

Adolescent↗

[Indications for sonography and follow-up studies. Initial results of a prospective study].

Ultrasonic examinations of the abdomen may result in expensive secondary imaging examinations. This prospective study was conducted in collaboration with the Zentralinstitut Köln. The first aim of our study was to compare the results of abdominal sonography in three different patient groups: The first group was comprised of patients referred for a medical check-up, the second group of patients referred because of upper abdominal pain and the third group of patients with generalized atherosclerosis. The second aim was to correlate sonographic findings (classified in three degrees of severity), with subsequently induced diagnostic procedures in the three groups. 2719 patients were enrolled, 2393 (88%) in group 1, 286 (11%) in group 2 and 40 (1%) in group 3. A total of 1792 abnormal findings were diagnosed. 65.6% of the findings in group 1, 65.7% in group 2 and 88% in group 3 were abnormal. Up to now, the findings led to a nearly equal number of subsequent diagnostic procedures in groups 1 and 2. The preliminary results show that abdominal sonography may be as effective in patients for a check-up as in patients referred because of a well-defined indication. Patients with defined abdominal symptoms show more abnormal sonographic findings than patients on a check-up. Higher costs resulting from subsequent examinations deserve critical assessment in the individual patient.

Abdomen↗

Identification of a splice mutation at the adenine phosphoribosyltransferase locus in a German family.

We examined the molecular basis of adenine phosphoribosyltransferase (APRT) deficiency in homozygous-deficient, identical twin brothers who were born to non-consanguineous German parents. DNA was isolated from blood, and the APRT gene was amplified by PCR, subcloned into M13, and sequenced completely. A single T insertion between bases 1831-1832 or 1832-1833 was identified. This alters the consensus sequence at the exon 4 - intron 4 spice donor site and leads to aberrant splicing. The same mutation has been described previously in two affected brothers from Belgium, and the Indianapolis group has also identified it in two other, unrelated Caucasian patients. Thus, this mutation may be a common cause of APRT deficiency in the Caucasian population.

Adenine Phosphoribosyltransferase↗

Uric acid levels in southern Germany in 1989. A comparison with studies from 1962, 1971, and 1984.

Since 1962 our group has performed four studies on uric acid values in blood donors in southern Germany (Bavaria). Uric acid levels in men have increased over the years, from 4.86 mg/dl in 1962 to 6.00 mg/dl in 1971, 5.60 mg/dl in 1984, and 5.90 mg/dl in 1989. Levels in women have increased slightly, from 4.05 mg/dl in 1962 to 4.35 mg/dl in 1971, 4.10 mg/dl in 1984, and 4.16 mg/dl in 1989. Women aged 51 to 60 years had significantly higher uric acid levels than those in the fourth decade. In women treated with oral contraceptives uric acid levels were significantly lower than in other women of the same age. Hypouricemia (uric acid levels less than or equal to 2.0 mg/dl) was observed in three women, none of whom had a history of medication. Hyperuricemia exists when uric acid levels are greater than or equal to 6.5 mg/dl. In 1989 2.6% of the female blood donors and 28.6% of the males were hyperuricemic, with an increased risk of gout, nephrolithiasis, and nephropathy.

Adult↗

[Eosinophilia myalgia syndrome in administration of L-tryptophan].

We present the case of a 35-year-old male patient with severe myalgia and arthralgia in combination with fatigue, nocturnal sweating, leucocytosis and eosinophilia after a history of two months treatment of sleep disturbances with L-tryptophane in a daily dose of 1500 mg. Four months after discontinuation of treatment symptoms are still present.

Adult↗

[Bone pain in adults as the first symptom of late congenital syphilis].

A 20-year-old woman developed multifocal bone pain. Diagnostic radiology revealed thickened periosteum, and syphilis serology was positive (T. pallidum haemagglutination test 1:5120). She also had discrete signs of congenital syphilis, with retinitis pigmentosa and Hutchinson's incisors. Skeletal scintigraphy demonstrated increased uptake even in radiologically unremarkable bones. The bone pain decreased after four-week administration of 1 M units of penicillin G daily. Scintigraphy one year later showed regression of the increased uptake, skeletal radiology did not reveal significant changes. This case shows that late manifestations of congenital syphilis still occur today. The stigmata of such an infection can be minute and easily missed. Skeletal scintigraphy is better for demonstrating active bone involvement than conventional radiology.

Adult↗

Sclerosing epitheloid angiosarcoma of bone and lung--intravascular sclerosing bronchioloalveolar tumor.

A 39-year-old woman was admitted to hospital with severe pain in the left shoulder due to an endothelial bone tumor. The tumor showed the same histologic signs as an intravascular sclerosing bronchioloalveolar tumor of the lung (IVBAT) which had been enucleated 2 years previously. This combination is uncommon. It is discussed whether the IVBAT is a malignant tumor with metastases or a benign tumor with coincidental tumors in other organs of the same endothelial vascular origin. We consider this to be an epitheloid angiosarcoma of the lung with, in our case, bone metastases; this is in agreement with some most recent reports on the disease.

Adult↗

Demonstration of a combined deficiency of xanthine oxidase and aldehyde oxidase in xanthinuric patients not forming oxipurinol.

Genetic heterogeneity has been suggested in xanthinuria from the hitherto unexplained ability of some patients with this hereditary disorder to convert allopurinol to its active metabolite oxipurinol--an activity generally attributed to xanthine oxidase. This study provides evidence that the enzyme aldehyde oxidase is also deficient in xanthinuric patients not converting allopurinol to oxipurinol, whereas a xanthinuric patient with normal formation of oxipurinol had normal aldehyde oxidase activity. It is concluded that the enzyme aldehyde oxidase is the principal enzyme responsible for the formation of oxipurinol in man.

Adult↗

Variation of benzbromarone elimination in man--a population study.

The plasma benzbromarone concentration-time profile in a healthy subject who retained the compound much longer than other individuals is described. The data suggested that determination of the 24 h plasma concentration of the parent drug after a single oral dose of 100 mg benzbromarone would be an appropriate procedure to determine the elimination phenotype. Based on this procedure, 148 of 153 healthy individuals (97%) in a population study were found to eliminate benzbromarone rapidly. In one subject the 24 h benzbromarone plasma concentration was very similar to that observed in the individual who had been more fully characterized. Four participants gave intermediate results. The data are compatible with a bimodal or trimodal distribution of different benzbromarone elimination phenotypes.

Adult↗

Uricosuric effect of different doses of irtemazole in normouricaemic subjects.

Irtemazole 12.5 to 50 mg in 6 healthy, normouricaemic subjects caused a maximal decrease in plasma uric acid (after 8 to 12 h) of 46.5%. The uricosuric effect began during the first 60 min after drug administration and it lasted for 7 to 24 h. Renal uric acid excretion returned to its base line value after 8 to 16 h and uric acid clearance after 10.0 to 12.0 h. Doses of irtemazole between 12.5 and 37.5 mg produced a dose-related rise in the uricosuric effect. There was no essential difference between the uricosuric effect of 37.5 mg and 50 mg irtemazole. The D50 dose (that producing a half-maximal effect) was between 16.3 mg and 34.2 mg, (average 24.7 mg). The value of irtemazole in the management of hyperuricaemia and gout remains to be determined.

Adult↗

Genetic evidence from 7 families that the apolipoprotein B gene is not involved in familial combined hyperlipidemia.

Familial combined hyperlipidemia (FCHL) is the most common genetic form of hyperlipidemia in which affected individuals manifest multiple lipoprotein phenotypes. Although the molecular defect is still unknown, several kinetic studies have demonstrated increased turnover rates of apolipoprotein B (apo B) in patients with FCHL, irrespective of their lipoprotein phenotype. Using 3 restriction fragment length polymorphisms (RFLPs) of the apo B gene (XbaI, MspI and EcoRI) we have investigated 33 families which fulfill the diagnostic criteria of FCHL. No significant difference in allele frequency was found between 33 unrelated individuals with FCHL and 107 normolipidemic controls. 3-RFLP haplotypes were constructed in each pedigree. A co-segregation analysis was performed in 7 informative families. In no family was co-segregation observed between the haplotype of the apo B gene and the phenotype of FCHL. These data are not compatible with the hypothesis that FCHL is caused by mutations of the apo B gene acting as a simple mendelian trait.

Adult↗

Effect of triiodothyronine on triglyceride synthesis in human fibroblasts in different types of hypertriglyceridemia.

Fibroblasts from 12 normotriglyceridemic subjects and 30 hypertriglyceridemic patients and family members were used to investigate triglyceride synthesis and the influence of triiodothyronine on it. The monolayers were incubated for 72 hours with and without the thyroid hormone, followed by incorporation studies of radiolabeled acetic acid or palmitic acid into the cellular triglyceride fraction. Triiodothyronine had no influence on triglyceride synthesis of normal cell lines and of cells derived from patients with secondary hypertriglyceridemia, whereas fibroblasts from endogenous type IV patients showed higher rates of triglyceride synthesis under identical conditions. Values for type IV were in the range of 134% to 466% of the hormone-free control incubations. In cultures derived from patients with familial combined hyperlipidemia, no stimulation by triiodothyronine was observed: values were in the range of 64% to 144% of the hormone-free controls. Three out of four lines with type V gave "normal" values and are supposed to represent secondary hypertriglyceridemia, whereas one line may express endogenous type IV. The evidence obtained in vitro with cultured cells indicates different metabolic defects in endogenous type IV and familial combined hyperlipidemia; it also shows the biochemically heterogenous nature of the disease "hypertriglyceridemia."

Acetates↗