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D Chadenas

Publications and source records attributed to D Chadenas.

At least 19 recordsLinked to original sources
PubMed1995

Proximal deletions of the long arm of the Y chromosome suggest a critical region associated with a specific subset of characteristic Turner stigmata.

Turner syndrome is a complex human disorder that generally associates a 45,X karyotype to a female phenotype presenting with gonadal dysgenesis, short stature and a number of characteristic somatic features. It has been hypothesized that this specific phenotype was the consequence of the haploinsufficiency of some X-linked genes having functional homologs on the Y chromosome. Here we describe four patients with deletions of the long arm of their Y chromosome and presenting with azoospermia and with or without Turner stigmata. Analysis of their breakpoints by Southern blotting and Y-specific sequence tagged sites (STS) allows us to delimit a region located in proximal interval 5 of the Y chromosome involved in skeletal development and growth.

Blotting, Southern↗
PubMed1992

[Mediastinal parathyroid adenomas on a 5th ectopic gland. 2 case reports].

Mediastinal parathyroid adenoma located on the 5th ectopic gland is rare. We report here two new cases diagnosed by scintigraphy. In one case the adenoma was found to be located in the mediastinum prior to cervicotomy. The modern imaging methods capable of locating parathyroid adenomas are evaluated.

Adenoma↗
PubMed1989

Screening for multiple endocrine neoplasia type 2a with DNA-polymorphism analysis.

Multiple endocrine neoplasia type 2a has been shown to be genetically linked to a locus near the centromere of chromosome 10. The availability of polymorphic DNA probes for the region permits the use of restriction-fragment-length polymorphisms (RFLP) to identify carriers of the gene for this cancer syndrome. As part of a French national program, DNA probes were used in a genetic-linkage study of 130 members of 11 families of European and North African origin. In these families there was no recombination between the mutation causing multiple endocrine neoplasia type 2a and two of the three probes used. All 11 families were informative for at least one of the three markers, and linkage information was adequate to provide genetic counseling to 8 families. We found that RFLP analysis is much more useful in predicting the carrier state than conventional endocrine challenge, especially in younger people, but accuracy is maximal when both methods are employed. We conclude that genetic screening allows the identification of those who are at risk for multiple endocrine neoplasia type 2a at any age with a high level of certainty. After initial screening with DNA, tests for early neoplastic change may be directed toward those determined to be at high risk.

Carcinoma↗
PubMed1987

[Abnormal concentration of aluminium in the lysosomes of a primary parathyroid adenoma].

A primitive parathyroid adenoma has been studied by electron microscopy, analytical ion microscopy and electron probe X ray analysis. A number of lysosomal structures has been observed in the cells. Observation of unstained ultrathin sections shows that these lysosomes contain two varieties of structures: dense homogeneous droplets and very dense and small granulations. Aluminium associated with phosphorus has been detected in high concentration in the small granulations. The relations between aluminium and parathyroid function and the possible role of aluminium in the pathology of the parathyroid gland remain to be clarified.

Adenoma↗
PubMed1986

[Polymyositis, dermatomyositis and pregnancy: high-risk pregnancy. A further case report and review of the literature].

The authors report a new case where polymyositis/dermatomyositis and pregnancy were associated. The polymyositis and dermatomyositis appeared in the last third of the pregnancy. A caesarean operation had to be performed for fetal distress after 37 weeks of amenorrhoea. An apparently dead small-for-dates baby was born. Progress, however, after resuscitation of the baby was good. At 20 months after delivery the polymyositis and dermatomyositis also were improved. Two and a half years later there was no recurrence. In the light of cases that have previously been reported in the literature, it has been established that on the one hand pregnancy may trigger off the condition and worsen the PM/DM and on the other hand the condition has a bad effect on the progress of the pregnancy. 50% of the babies are born dead or die in the week after delivery and 55% are born prematurely. We discuss the possibility that PM/DM is of viral origin. A confirmation of this is the presence of viral inclusion bodies on electron microscopy found in the muscle cells of the patients who have PM/DM. However, in the previous history of these patients an acute viral myositis in childhood is a troublesome factor. Pregnancy, because it involves alterations in the immune responses of the patients, may lead to a recrudescence of a "sleeping" virus and so be responsible for the appearance or aggravation of polymyositis and dermatomyositis.

Adult↗
PubMed1985

[Endocrine pancreatic tumor secreting somatostatin and somatocrinin].

A case of endocrine pancreatic tumour secreting the 2 antagonistic peptides that regulate growth hormone, somatostatin and somatocrinin, is reported. Such tumours are extremely rare and only one other case has been published so far, although pancreatic malignant tumours frequently secrete several hormones. In our patient, the association of diabetes with steatorrhoea, hypochlorhydria, anaemia and biliary lithiasis suggested hypersecretion of somatostatin. Acromegaly, suggested by clinical signs, was confirmed by an excess of growth hormone and somatomedin, and pre-operative somatrocrinin assay confirmed its extra-pituitary origin. Finally, the presence of hyperparathyroidism due to parathyroid gland hyperplasia and of a Recklinghausen disease constituted a multiple endocrine neoplasia syndrome. The significance and implications of this double secretion in vivo are discussed.

Adenoma, Islet Cell↗