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Biomedical subjects

J L Frias

Publications and source records attributed to J L Frias.

At least 73 records · Page 4Linked to original sources
PubMed1974

Growth hormone deficiency with hypoglycemia, genital hypoplasia and frontal prominence.

A boy with neonatal hypoglycemia, genital hypoplasia and frontal prominence ahd recurrence of hypoglycemic seizures at age 17 months. There was no plasma growth hormone (GH) response to sleep, arginine, hypoglycemia or glucagon. Mild secondary hypothroidism and primary hypogonadism were demonstrated. Small dose testosterone therapy for three months resulted in normal penile size; weekly injections of GH accelerated linear growth to a normal pace. Whether this complex represents a true syndrome or part of the spectrum of panhypopituitarism remains to be answered.

Face↗
PubMedDate not supplied

Teratogens and teratogenesis: general principles of clinical teratology.

Numerous factors hinder our ability to recognize fully human teratogens. Among these are the limitations of animal and epidemiologic studies, the lack of understanding of the mechanisms of action of most teratogens, and the variability in expression of the clinical manifestation. Dose and timing of exposure, interactions with other environmental agents, and host susceptibility influence this variable expressivity. Recent studies suggest the genetic constitution of the mother and the fetus play a central role in the teratogenic response. Techniques currently being developed may help in a near future to identify susceptible individuals and to prevent specific types of drug-induced birth defects.

Abnormalities, Drug-Induced↗
PubMedDate not supplied

The cardiovascular manifestations of genetic disorders of collagen metabolism.

Current research in the biochemistry and molecular genetics of collagen metabolism has produced a sophisticated level of understanding of the mechanisms involved in the pathogenesis of a number of inherited diseases of connective tissue. Nowhere is this better exemplified than in the cardiovascular disorders associated with certain genetic disorders of collagen metabolism. For instance, the life-threatening vascular complications of Ehlers-Danlos syndrome IV, the Sack-Barabas type, appears to be related to a number of defects in the production of Type III procollagen. The large size of the collagen genes and the complexity of the biochemistry of collagen have not made research a simple task. Nevertheless, the location of certain genes is now known with a reasonable degree of accuracy and a few have been cloned in their entirety. The future investigation of these genetic mutations holds great excitement for those engaged in research in this fascinating field.

Cardiovascular Diseases↗
PubMedDate not supplied

The heart in selected congenital malformations. A lesson in pathogenetic relationships.

The application of new knowledge on the pathogenesis of congenital heart defects has increased our understanding of associated, non-cardiac malformations seen in certain syndromes. Defects in the proliferation and migration of neural crest cells are thought to contribute to conotruncal defects. These are seen in association with conditions such as DiGeorge syndrome. CHARGE association, hemifacial microsomia, and Shprintzen syndrome. They also form part of the isotretinoin and thalidomide embryopathies. Their association with conotruncal defects suggests that abnormal migration of neural crest cells may play a role in the pathogenesis of these syndromes.

Abnormalities, Multiple↗
PubMedDate not supplied

Cancer of endocrine glands and target organs: genetic considerations.

The pathogenesis of cancer in general is influenced by many factors, genetic and environmental. Epidemiological studies demonstrate familial aggregation of cancer in a significant proportion of cases. Many of these familial cancer syndromes contain endocrine hormone-related components. The etiology of endocrine-related cancers is complex, as is that of other cancers. Tumors of endocrine glands and target organs are subject to the same influences as other cancers; an additional variable is that of hormone-responsiveness.

Adrenal Gland Neoplasms↗
PubMedDate not supplied

Medullary carcinoma of the thyroid in the multiple mucosal neuromas syndrome.

The clinical features of the multiple mucosal neuromas (MMN) syndrome permit the recognition of these patients and their potential development of the associated medullary thyroid carcinoma (MTC). The distinctive physical appearance caused by the mucosal neuromas, the Marfanoid habitus and, occasionally, the positive family history aid in establishing the diagnosis. Neurogangliomas are frequently present in the gastrointestinal tract of these patients who may have megacolon, constipation and diarrhea. The third instance of the MMN syndrome is reported in the newborn as intestinal obstruction. It is suggested that the syndrome be considered in the differential diagnosis of Hirschsprung's disease and bowel obstruction in the neonate. Serum calcitonin measurements following stimulation by calcium or pentagastrin infusion reliably detect incipient MTC and may be used to select those MMN patients requiring thyroid surgery. Recognition of patients with the MMN syndrome and subsequent calcitonin screening and early surgical intervention will significantly reduce the chance of their developing terminal MTC. All MMN patients with mucosal neuromas or intestinal neurogangliomas should have such evaluations at least yearly. Relatives who are at risk for inheriting this dominant disease should be similarly evaluated, regardless of their normal appearance.

Adrenal Gland Neoplasms↗