Henry Ford Hospital medical journal最新文献

Pheochromocytomas occur sporadically or in individuals affected by inherited syndromes including multiple endocrine neoplasia (MEN) type 2A and 2B, neurofibromatosis, and the von Hippel-Lindau syndrome (vHL). Medullary thyroid carcinomas (MTCs) also occur sporadically or as part of MEN 2A, MEN 2B, and familial MTC. Little is known of the molecular genetic background of these tumors. We have shown previously that activation of the N-ras, H-ras, and K-ras oncogenes does not occur in these tumors, but that deletions of the short arm of chromosome 1 are extremely common (> 60%) and may indicate loss of a suppressor gene in the chromosomal region 1p31-36. We have examined the structure and expression of N-myc, c-myc, L-myc, c-mos, nerve growth factor (beta-NGF), and the low affinity nerve growth factor receptor (LNGFR) in a series of pheochromocytomas and MTCs from patients with hereditary and sporadic diseases. Southern analysis, using radiolabeled DNA probes, revealed no evidence of amplification or rearrangement of these genes in any normal or tumor tissues except for loss of heterozygosity at the L-myc locus (1p32) in 9 pheochromocytomas from patients with MEN 2A or MEN 2B, in 5 of 11 non-MEN pheochromocytomas, and in 3 of 24 non-MEN MTCs. Gene expression at the RNA level was examined by Northern analysis or ribonuclease protection assay (RPA) using radiolabeled DNA or cRNA probes. C-myc transcripts were detectable at low levels in all tumors tested.(ABSTRACT TRUNCATED AT 250 WORDS)

Nine chromosome 10 DNA markers (FNRB, D10S34, D10Z1, MEN203, D10S94, RBP3, D10S15, MBP [48.11], D10S22) were typed in two large Canadian pedigrees with multiple endocrine neoplasia type 2A (MEN 2A). These markers and the gene for MEN 2A (MEN2A) are believed to be in one linkage group spanning approximately 15 cM (male). MEN203 and D10S94 were informative and tightly linked to MEN2A with no recombinants observed in 26 meiotic events. D10S15 (MCK2), widely used in DNA genotyping predictions, demonstrated two recombinants in these two families. The use of multiple flanking markers increases both the likelihood of informativeness and the accuracy of risk assessments for predictive testing. We were able to assign a risk estimate for all 10 at-risk individuals.

Familial multiple endocrine neoplasia type 1 (FMEN 1) is an autosomal dominant disorder characterized by tumors of the parathyroid glands, pancreatic islets, and anterior pituitary. Hyperplasia appears to be the typical histopathological lesion in FMEN 1 endocrine tumors. A circulating mitogen related to basic fibroblast growth factor was active on proliferation of clonal bovine and human parathyroid endothelial cells. Moreover, the FMEN 1 mitogen modulated differentiation of human parathyroid endothelial cell in vitro. All these facts suggested that an extrinsic factor was active on parathyroid endothelial cell growth and differentiation. The FMEN 1 gene maps to chromosome 11q13, and allelic loss in this region has been shown in FMEN 1 parathyroid and pancreatic islet tumors and rarely in anterior pituitary tumors. Together these results support the theory that FMEN 1 parathyroid clonal lesions can develop in the context of generalized hyperplasia. Similarly, in uremic hyperparathyroidism, where parathyroid hyperplasia is thought to be the primary lesion, loss of constitutional heterozygosity for chromosome 11 markers coexists in parathyroid tissue with a polyclonal pattern. Future efforts of scientists working on this genetic disorder will focus on the cloning of the FMEN 1 gene and the development of a suitable bioassay system to study its function.

The search for the gene that causes the multiple endocrine neoplasia type 2A (MEN 2A) syndrome is entering a new phase. Genetic linkage studies have localized the gene to the pericentromeric region of chromosome 10. The statistical portion of mapping the gene for MEN 2A is nearly complete and now classical molecular biological/gene mapping techniques will be employed. We have used fluorescence in situ hybridization to estimate the size of the MEN2A region to be about 2 to 5 mb, using some liberal assumptions; at worst the region should contain no more than about 10 mb of non-alphoid DNA. Our mapping panels (meiotic recombinant and radiation reduced hybrid) give consistent orders of markers in this small region. We describe our initial attempts to clone the region using yeast artificial chromosomes.

Tumorigenesis in multiple endocrine neoplasia type 1 (MEN 1) involves the unmasking of a recessive mutation at the MEN 1 locus which has been mapped to chromosomal region 11q11-13. By analyzing 58 DNA markers on a panel of radiation-reduced somatic cell hybrids, the region encompassing the MEN 1 gene was divided into nine subregions. Pulsed field gel electrophoresis analysis of markers within subgroups showed that the recombination rate around the MEN 1 locus is high. Combined linkage analysis in MEN 1 families and deletion mapping in MEN 1-related tumors suggest the MEN 1 gene is located centromeric to D11S807 and telomeric to PYGM.

Familial multiple endocrine neoplasia type 1 (MEN 1) is an autosomal dominant disorder characterized by the combined occurrence of tumors of the parathyroid glands, the endocrine pancreas, and the pituitary gland. MEN 1 tumors have previously been shown to be associated with the loss of alleles on chromosome 11, and deletion mapping studies together with family linkage studies have localized the MEN 1 gene to 11q13. A detailed genetic map around the MEN 1 locus is required to facilitate further characterization and cloning of the gene (MEN1). We have characterized a panel of seven rodent-human somatic cell hybrids which contain fragments of human chromosome 11 with breakpoints in the pericentromeric region by using eight DNA sequences (D11S149, PGA, PYGM, D11S97, INT2, D11S37, D11S533, and D11S147) to define the region containing MEN1. This will facilitate the rapid localization of additional DNA sequences in this region. In addition, we have used a highly polymorphic repetitive degenerate hexanucleotide sequence, designated D11S533, for segregation studies in one family with MEN 1. These molecular genetic approaches will help to define a precise 1 to 2 centiMorgan map around MEN1.

GH and FA are useful monitors in the care of diabetic patients. For most situations, GH is the preferred test and should be routinely monitored. FA should be reserved for exceptional situations in which blood glucose control over one to two weeks must be assessed or in patients with a hemoglobinopathy. Patients with diabetes should be advised of their present GH level and the preferred goal.

Although the United States spends more on health care than any country in the world, access to that care is becoming increasingly difficult. The National Cancer Institute and other federal agencies are sponsoring innovative research for delivering effective medical services, particularly to underserved populations. Models of successful collaboration between private and public sectors concerned with health care can be adapted and implemented at the national, state, and local levels. However, other measures are needed to ensure access to adequate health care for all Americans. Minimal but effective regulations are needed to ensure quality control, reduce duplication of services, and minimize cost increases. Public and private sectors also need to consider ways to extend adequate health insurance coverage to all Americans and to provide compensation for preventive services.

Primary management of advanced (stage D) adenocarcinoma of the prostate is androgen ablation. Since this principle was discovered in the early 1940s, therapeutic alternatives and "progress" have centered around different ways to obtain castrate levels of androgens. The role of adrenal androgens in supporting prostate or prostatic cancer growth has been debated for decades and until recently was believed to be minimal. In the 1980s the concept of maximum androgen suppression, involving both the testes and adrenal glands, was reintroduced with some investigators claiming exceptional results. We review studies that have examined this concept, with emphasis on the largest trial which was carried out by the National Cancer Institute.