PubMed Health⌕ Search

Biomedical subjects

H P Neumann

Publications and source records attributed to H P Neumann.

108 records · Page 6Linked to original sources
PubMed1990

Application of linked DNA markers to screening families with multiple endocrine neoplasia type 2A.

There now exists a set of tightly linked markers to the gene causing multiple endocrine neoplasia type 2A. In this report we discuss the use of these markers for early and accurate prediction of gene carrier status in three different families. Factors that influence the probability of obtaining useful information with DNA markers are available family size, in particular the number of available affected individuals, and the extent of clinical and biochemical screening in the family. At present, DNA analysis has about a 3% risk of misdiagnosis; this risk is even lower if it is used in conjunction with the pentagastrin stimulation test for C-cell hyperplasia. With the combined tests, an individual at age 20 years may be scored as carrier or not with an estimated accuracy of 99%.

Adolescent↗
PubMed1989

Early diagnosis of multiple endocrine neoplasia type IIa.

We report on incidental findings during family screening of two kindreds with multiple endocrine neoplasia type IIa. Pheochromocytoma and medullary thyroid carcinoma of considerable size were detected. The results underline the importance of early diagnosis of the syndrome, since the afflicted may be almost or wholly asymptomatic. High resolution chromosome banding studies were carried out in both families, but no abnormality was found. Linkage analysis using DNA markers closely related to the chromosomal locus at chromosome 10 was carried out and was positive in two asymptomatic offspring of one family, whereas the markers were not informative in a second family. We recommend early linkage analysis for establishing the genetic status in offspring of multiple endocrine neoplasia type IIa families to identify for further screening those who are predicted to be gene carrier.

Adrenal Gland Neoplasms↗
PubMed1989

Cytogenetic studies on three pheochromocytomas derived from patients with von Hippel-Lindau syndrome.

Chromosomal analyses of three pheochromocytomas from patients with von Hippel-Lindau syndrome are reported. One pheochromocytoma revealed a normal karyotype, another tumor showed a trisomy 7 as the only chromosomal abnormality, whereas in a further sample a polyclonal chromosome constitution was detected. In addition to a normal 46,XX cell line, four distinct chromosomally abnormal cell lines could be identified. One cell line revealed partial trisomy for the long arm of chromosome 1 and additionally exhibited the phenomenon of telomeric association. Most interestingly, three further cell clones showed rearrangements of chromosome 3 including the region where the von Hippel-Lindau gene was mapped; three rearrangements resulted in a partial or total trisomy of 3p. Our findings are discussed in relation to previously reported cytogenetic and molecular results regarding von Hippel-Lindau syndrome.

Adrenal Gland Neoplasms↗
PubMed1989

Loss of heterozygosity on 3p in a renal cell carcinoma in von Hippel-Lindau syndrome.

A renal cell carcinoma with an unbalanced t(X;3) in a patient with von Hippel-Lindau (VHL) syndrome has previously been reported. This rearrangement suggested loss of genetic material from the short arm of chromosome 3, which we are now able to confirm by restriction fragment length polymorphism analysis of tumor DNA using polymorphic probes derived from 3p. The VHL gene has recently been mapped to 3p, therefore loss of this region in this VHL-related renal cell carcinoma may have cogent significance for tumor development in this interesting cancer-predisposing syndrome.

Angiomatosis↗
PubMed1989

Hemangioblastomas of the central nervous system. A 10-year study with special reference to von Hippel-Lindau syndrome.

The findings of a 10-year study (1976 to 1986) conducted in southwest Germany on hemangioblastomas (HBL's) of the central nervous system (CNS) are presented. During that period, 47 HBL's were diagnosed and surgically removed in 44 patients, with a good postoperative survival rate and prognosis. The majority (83%) of these tumors were located in the cerebellum. By thorough clinical examination of the patients and careful evaluation of their family background, it was found that 23% of the HBL patients were afflicted with von Hippel-Lindau syndrome. In addition to the CNS tumors, 14 neoplastic or similar lesions were detected in other tissues. These included angiomatosis of the retinae, pheochromocytomas, pancreatic cysts, renal cysts, and renal carcinoma. The diagnosis of von Hippel-Lindau syndrome was thus established in seven families. The authors suggest the need for a screening program for patients with HBL of the CNS which is designed to confirm or exclude ocular or visceral lesions associated with von Hippel-Lindau syndrome.

Adolescent↗
PubMed1988

Extraction of an intracardial catheter embolus using combined radiography and transesophageal echocardiography.

Embolism of a fragment of a central venous catheter is a serious clinical complication, especially when the fragment cannot be made visible by radiological methods. We report a case where such a fragment could only be localized by transesophageal echocardiography (TEE). With combined use of x-rays and TEE, the catheter embolus was successfully extracted using a conventional Dormia catheter. For similar situations the described procedure is recommended.

Adult↗
PubMed1988

High-resolution chromosome banding and fragile site studies in von Hippel-Lindau syndrome.

von Hippel-Lindau syndrome is an autosomal dominant disorder that predisposes to the development of benign and malignant tumors. The gene for von Hippel-Lindau syndrome has not yet been localized and the cytogenetics of this cancer-prone genetic disease have not been fully explored. Therefore, we did high-resolution chromosome banding of lymphocytes from patients from 14 kindreds with von Hippel-Lindau syndrome. There were 18 patients (eight male, and ten female). None of the male patients showed a detectable chromosome abnormality. However, three of the ten female patients had 45,X/46,XX/47,XXX chromosome mosaicism with predominance of the normal cell line. Fragile sites at 10q25 and 16q22 were found but both segregated independently of von Hippel-Lindau syndrome. The location of this disease gene, thus, is still unknown. The tendency to chromosome mosaicism manifest in this study suggests that there is a possible error in controlling somatic chromosome division and that error in mitosis may be causally related to the predisposition to tumor formation in von Hippel-Lindau syndrome.

Adult↗
PubMed1987

Autosomal recessive and dominant forms of polycystic kidney disease are not allelic.

Linkage analysis has been carried out in 11 kindreds with autosomal recessive polycystic kidney disease (ARPKD) using the genetic marker 3'HVR, closely linked (theta = 0.05) to the gene of the autosomal dominant type. Close linkage (theta less than or equal to 0.20) between the locus of the marker and that of ARPKD can be excluded. These data strongly suggest that the loci for the autosomal recessive and dominant forms of polycystic kidney disease are not allelic.

Alleles↗
PubMed1985

Mild proteinuria in patients with unilateral kidney.

Arterial blood pressure, 24 h urinary excretion, and glomerular filtration rate (GFR) in 24 patients with unilateral kidney were compared with an age and sex matched control group of healthy persons. Of the patients with unilateral kidney, 13 were uninephrectomized and 11 patients had a congenital unilateral kidney. The 24 h urinary protein excretion in patients with one kidney was significantly higher (630 +/- 51 mg/24 h) compared to the control group (206 +/- 36 mg/24 h). The arterial systolic and diastolic blood pressures and GFR did not differ in both groups. Furthermore, no differences were found between patients with unilateral kidneys following nephrectomy or renal agenesis. This study shows that mild proteinuria occurs in patients with unilateral kidney. An increased risk for deterioration in renal function or severe arterial hypertension was not detected in this investigation.

Adolescent↗