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Biomedical subjects

J M Friedman

Publications and source records attributed to J M Friedman.

At least 289 records · Page 16Linked to original sources
PubMed1982

An unusual connective tissue disease in mother and son: a "new" type of Ehlers-Danlos syndrome?

A 23-year-old woman and her 2 1/2-year-old son both had large hernias, positional foot deformities, abnormal thoracic shape, asthma, and severe eczematoid dermatitis. Their facial appearance was quite similar and included asymmetry with prominent nasal bridge and small jaw. In addition, the mother had severe thoracolumbar kyphoscolosis and "cigarette paper" scars over her legs. She died after rupture of a a thoracic aortic aneurysm and was found on postmortem examination to have cystic medionecrosis of the aorta and myxomatous degeneration and elongation of the mitral and tricuspid valves. The family history was otherwise negative; there was no consanguinity. The connective tissue disease in this mother and her son appears to be a previously unrecognized dominantly-inherited disorder with some similarity to classical Ehlers-Danlos syndrome.

Abnormalities, Multiple↗
PubMed1982

Probable clonal origin of neurofibrosarcoma in a patient with hereditary neurofibromatosis.

A neurofibroma, a fibroma, a primary neurofibrosarcoma, and four neurofibrosarcoma metastases from a woman with hereditary neurofibromatosis who was heterozygous (GdB/GdA-) for the X-linked enzyme glucose-6-phosphate dehydrogenase were studied to determine the number of cells from which the tumors developed. Both enzyme types were observed in the benign tumors in proportions similar to those present in seven different normal tissues studied. These findings indicated that the benign tumors arose from many cells. In marked contrast, only type A activity was detected in the primary neurofibrosarcoma and in all of the metastases. Two or more steps probably were involved in the development of neurofibrosarcoma in this patient: the inherited genetic mutation producing neurofibromatosis and a rare event or combination of events that permitted a single cell to undergo malignant proliferation.

Adult↗
PubMed1981

Stroke, orthostatic hypotension, and focal seizures.

A 75-year-old man had development of left hemiparesis after a cerebral infarction. Nine months later, he was admitted to the hospital after generalized tonic clonic convulsion. In the hospital, he had clonic movement on the left side of the body. Even after acceptable control of orthostatic hypotension, rising from supine to standing position evoked slow waves over the right hemisphere on the EEG tracing. This example of focal seizures with orthostatic hypotension shows that previously compromised cerebral tissue or vessels may be vulnerable to changes in blood pressure. We suggest that convulsive movements associated with hypotension or syncope result from cortical mechanisms rather than brainstem tonic release mechanisms.

Aged↗
PubMed1981

Genetic disease in the offspring of older fathers.

Autosomal dominant genetic diseases may result from the transmission of a trait by a carrier parent or from gene mutation in one of the gametes from which the child develops. The mean age of fathers of affected persons has been found to be greater than expected for several autosomal dominant diseases due to new mutations. To assess the clinical importance of this observation, the relative and absolute frequencies of offspring with autosomal dominant diseases due to mutation in the sperm from fathers of various ages have been calculated. The relative frequency of new autosomal dominant mutations in children increases logarithmically with paternal age during the usual years of fatherhood. The absolute frequency of autosomal dominant disease due to new mutations among the offspring of fathers who are 40 years of age or older is estimated to be at least 0.3 to 0.5%. This risk is many times greater than that for children of young fathers and is similar in magnitude to the risk of Down syndrome among the offspring of 35- to 40-year-old mothers. Thus, it is good public health policy to recommend that both men and women complete their family a before age 40, if possible.

Achondroplasia↗
PubMed1980

Binary developmental commitments in normal and abnormal human morphogenesis.

An hypothesis is presented to account for the occurrence of overlapping patterns of anomalies in various malformation syndromes. According to this proposal, normal human morphogenesis occurs by means of a series of sequential commitments by neighboring groups of cells to alternative developmental programs.

Abnormalities, Multiple↗
PubMed1980

The use of probability trees in genetic counselling.

Calculation of genetic risks of persons who may be carriers of X-linked recessive conditions or autosomal dominant diseases with incomplete or delayed penetrance often requires the use of Bayes' theorem. Available methods of computing such risks are often too difficult or too time-consuming for clinicians to use routinely. Probability trees provide a rapid and simple graphical means of estimating genetic risks even in complex clinical situations. The use of probability trees is easily learned because the logic upon which they are based is inherent in their structure.

Adult↗
PubMed1979

Acute nonlymphocytic leukemia: expression in cells restricted to granulocytic and monocytic differentiation.

Two patients with acute nonlymphocytic leukemia who were heterozygous for the X-chromosome-linked enzyme glucose-6-phosphate dehydrogenase were studied to determine the number and type of cells in which the disease arises. Both type A and B isoenzymes were found in normal tissues, but the myeloblasts showed only one enzyme type, indicating that at the time of study, the disease had a clonal origin. The observation in one patient that erythroid cells did not arise from this clone contrasts with conclusions reached in patients previously studied with chromosomal markers. The results suggest that in this patient, the leukemic clone suppressed expression of normal granulopoiesis but did not inhibit erythroid differentiation from normal progenitors. They suggest also that the disease is heterogeneous. In some patients, the disease is expressed in cells with differentiation restricted to the granulocyte-macrophage pathway; in others, it involves stem cells that also differentiate into erythrocytes. This heterogeneity may reflect differences in causation and could have prognostic importance.

Acute Disease↗
PubMed1979

Protein-heme interaction in hemoglobin: evidence from Raman difference spectroscopy.

Raman difference spectroscopy measurements on native and chemically modified human deoxyhemoglobins stabilized in either the R or the T quaternary structure revealed frequency differences in the oxidation state marker lines. The differences indicate that the R structure has an effective increase in the electron density of the antibonding pi* orbitals of the porphyrin rings. This increase is explained by a charge transfer interaction between donor orbitals and the pi* orbitals of the porphyrins. The relative amount of charge transferred, which is inferred from the Raman difference measurements, correlates with some but not all factors that influence the energetics of the quaternary structure equilibrium. In addition, the free energy of cooperativity for a variety of ligated proteins follows the same order as that of the degree of charge depletion of the pi* orbitals upon ligation as determined from the frequency of a Raman mode. The proposed electronic interaction between the protein and heme could result in energies large enough to provide a significant contribution to the energetics of hemoglobin cooperativity.

Allosteric Regulation↗