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Biomedical subjects

J Bernstein

Publications and source records attributed to J Bernstein.

At least 289 records · Page 16Linked to original sources
PubMed1977

Determination of X-ray spectra incident on and transmitted through breast tissue.

X-ray spectra incident on and transmitted through breast tissue were measured using a fresh whole excised breast. These spectra and corresponding radiographs show that hardening of the beam from a molybdenum-anoda x-ray tube by a 0.5-mm AI filter instead of the conventional 0.03-mm Mo filter allows shorter exposure times and reduces patient exposure. Acceptable image contrast is preserved in mammography of thick or dense breasts.

Female↗
PubMed1977

Image quality in mammography.

Image quality in mammography is affected by the shape, size, and x-ray absorption properties of the anatomic part or lesion to be radiographed in addition to x-ray beam quality, geometric unsharpness, and the resolution, characteristic curve, and noise properties of the recording system. The authors review x-ray energy spectra, modulation transfer functions. Wiener spectra, characteristic and gradient curves, and radiographs of a breast phantom and a resected breast specimen containing microcalcifications; these factors, and the complex relationship between them, affect image quality and patient radiation exposure. Evaluation of the best system or technique for obtaining a breast image is discussed in terms of the compromise between diagnostic certainty and cost or risk.

Breast Neoplasms↗
PubMed1976

Wilms' tumor in adolescence.

Two cases of Wilms' tumor in adolescent males are presented. The clinical and radiographic findings were unusual and both presented atypical gross and microscopic features that could be correlated with the radiographic findings. Histologic examination of both tumors showed evidence of tubular and glomerular maturation, a feature usually associated with Wilms' tumors of early infancy. One of the tumors contained a large amount of cartilage and bone. The other was grossly cystic and incorporated some features of multilocular cystadenoma, a benign metanephric tumor.

Adolescent↗
PubMed1976

The significance of focal sclerotic lesions of glomeruli in children.

To establish the relationship between the type of focal sclerotic lesion of glomeruli and the development of progressive renal disease, the clinical courses of 20 children with focal segmental and 7 with focal global sclerosis were analyzed. Only five patients, all of them with focal segmental sclerosis, did not have the nephrotic syndrome, although all had proteinuria. Results suggest that patients with focal global sclerosis have a course identical to that of children with the minimal lesion form of nephrotic syndrome: onset in early childhood, response to steroid therapy, and a relapsing, nonprogressive course. Focal segmental sclerosis, in constrast, is characterized by older age at onset, high incidence of nephritic symptoms, lack of response to steroid therapy, and a progressive course with histologic and functional deterioration. Since most published reports have not distinguished between these two entities, a more favorable prognosis in focal segmental sclerosis may be inferred than is actually the case.

Adolescent↗
PubMed1976

Intracytoplasmic inclusion bodies in the chondrocytes of type I lethal achondrogenesis.

Lethal achondrogenesis in the past has been frequently confused with achondroplasia. Clinical and radiologic advances in the last decade have led to clear differentiation of this condition from other types of bone dysplasia. It is further separated into two types on the basis of radiographic and pathologic findings. Re-evaluation of the histologic features has led to the recognition of heretofore unrecognized intracytoplasmic inclusion bodies in the chondrocytes of type 1 achondrogenesis. The finding of inclusions strengthens the differentiation of the two types and may have implications for the pathogenesis of the form of chondrodystrophy.

Bone and Bones↗
PubMed1976

A conformational study of beta-phenethanolamine receptor sites. 8. Pharmacological study of 3-isopropylamino-2-phenyl-trans-2-decalols.

Two N-isopropylnorephedrines and their four possible decalol analogs were compared pharmacologically. Four of the six compounds at a concentration of 1 x 10(-4) M caused a potentiation of D(-)-norepinephrine (NE) contraction of the rat vas deferens and increased the maximal response of the preparation to NE. Pretreatment in vivo with reserpine (5 mg/kg ip) 24 hr before the experiment in vitro did not change these effects. At a concentration higher than 1 x 10(-3) M all of the decalin analogs antagonized the effects of NE. All of the analogs lowered the dog blood pressure briefly. The lowering of blood pressure was augmented by alpha-adrenergic blockade and was not changed by beta-adrenergic blockade, atropine, or a ganglionic blocking agent. Tachyphylaxis was not observed. The spontaneous contraction of isolated rabbit atria was depressed by the substances at concentrations of 1 x 10(-4)-1 x 10(-3) M. Catecholamine uptake in rat vas deferens was lowered by the substances and all of them produced a release of catecholamines from vas deferens. By virtue of the conformational rigidity of the decalols, possible inferences concerning the stereochemical aspects of the interaction of the ephedrine analogs with adrenergic neurone-receptor sites are discussed.

Animals↗
PubMed1976

Biochemical and ultrastructural correlates of substrate stimulation of renal organic anion transport.

Penicillin pretreatment enhanced the rate of PAH uptake into separated proximal tubules (collagenase digestion) from 2-week New Zealand white rabbits. A double reciprocal plot of these data suggests that penicillin increases the maximal velocity of PAH uptake. Na, K-ATPase was less in adult tissue but was unaffected by penicillin. No ultrastructural changes could be attributed to the treatment. Thus substrate stimulation of PAH transport does not involve Na, K-ATPase and probably involves soluble, rather than structural proteins.

Adenosine Triphosphatases↗
PubMed1976

A classification of renal cysts.

Renal cysts are a heterogeneous group comprising heritable, developmental, and acquired disorders. The classification presented here has been developed, as have several others in the past, to incorporate radiographic, functional, and genetic contributions in its clinicopathologic correlations. Its major categories are as follows: (1) dysplastic cysts arising in kidneys that have undergone abnormal morphogenesis and differentiation; (2) polycystic disease of autosomal recessive and autosomal dominant types; (3) heritable syndromes of multiple malformations with renal cysts resulting from presumed metabolic injury; (4) isolated cortical cysts of unknown pathogenesis; (5) medullary cysts of several types, including medullary sponge kidney and the progressive syndromes of medullary cystic disease, familial juvenile nephronophthisis, and renal-retinal dysplasia; (6) acquired parenchymal cysts of diverse origins; and (7) extraparenchymal cysts. This classification, which has been revised repeatedly over the years, is still tentative and undoubtedly will be revised again.

Abnormalities, Multiple↗
PubMed1976

Lethal short-limbed chondrodysplasia in early infancy.

Nineteen cases of chondrodysplastic short-limbed dwarfism in early infancy were studied in the context of current clinical classification based on established radiographic criteria. The histopathologic findings were sufficiently distinctive in most categories to provide additional diagnostic criteria and to contribute to the understanding and delineation of these disorders. 1. Homozygous achondroplasia is distinguished by markedly disturbed endochondral ossification that differs from the pattern seen in typical heterozygous achondroplasia. The physeal chondrocytes contain abundant granules of glycogen. 2. Achondrogenesis, the severest form of chondrodysplasia, exists in 2 types, in which the histopathologic findings appear to be distinctive and diagnostic. Type 1 is characterized by severe disturbance in endochondral ossification. The zone of resting cartilage contains relatively normal matrix, and the chondrocytes contain intracytoplasmic inclusions. The cartilaginous matrix in type 2 is markedly deficient, and the chondrocytes have a large, primitive, mesenchymatous appearance. 3. Thanatophoric dwarfism is associated with disorganized endochondral ossification similar to that in homozygous achondroplasia, but there is no accumulation of glycogen within chondrocytes. Type 2 thanatophoric dwarfism is differentiated from classical type 1 by the presence of cloverleaf skull and histologically by many bone-lined, penetrating vascular canals in the physis and by hyperactive osteoblasts and osteoclasts in the metaphysis. 4. Asphyxiating thoracic dysplasia of Jeune is differentiated histologically into 2 types. Type 1 is characterized by patchy distribution of endochondral ossification in the physis, irregular physeal-metaphyseal junction and large islands of poorly mineralized cartilage in the metaphysis. Type 2 is characterized by uniform distribution of endochondral ossification that is disorganized and is accompanied by advancing cartilage forming latticelike meshwork in the metaphysis. 5. Chondroectodermal dysplasia, which is radiographically similar to asphyxiating thoracic dysplasia, is marked by the presence of large islands of poorly mineralized cartilage in the spongiosa of vertebral bodies. Disorganized endochondral ossification is, however, uniformly distributed, and there is no latticelike advancing cartilage in the metaphysis. 6. Chondrodysplasia punctata is characterized by myxoid and cystic degeneration of physeal and epiphyseal cartilage with focal calcification. Type 2 (Conradi-Hünermann) has a nearly normal pattern of endochondral ossification, even though there may be severe disturbance and retardation of the process. The columnization of physeal chondrocytes is normal. Type 1 (rhizomelic) differs by having markedly retarded and disorganized endochondral ossification. 7...

Achondroplasia↗
PubMed1975

Correlation of head circumference and crown-rump length in newborn infants. A potential indicator of congenital maldevelopment.

A study of 305 consecutive neonatal autopsies done by two prosectors showed a high correlation between the head circumference (HC) and crown-rump length (CR). The calculated formula can be stated approximately as HC equals 0.9 CR + 2.5 cm, and the two measurements are for all practical purposes equal in the immediate neonatal period, regardless of race, sex, age and body weight. When the HC was found to be significantly larger than CR, hydrocephalus and certain types of chondrodystrophy were present. When the HC was significantly smaller than CR, there was a higher incidence of congenital heart disease, especially hypoplastic left heart syndrome, and congenital central nervous system disorders other than hydrocephalus. From a practical point of view, a significant difference is a discrepancy of more than 2.5 cm. 102 consecutive living neonates were also similarly studied. It appears that the CR length when carefully measured under standardized condition is more reliable than the crown-heel length.

Body Height↗
PubMed1975

Renal cystic disease associated with tuberous sclerosis complex: renal failure treated by cadaveric kidney transplantation.

Chronic renal failure in patients with tuberous sclerosis may be secondary to diffuse cystic disease, a lesion less common than the better known hamartomatous angiomyolipomas. Uremia, in the case of a nineteen-year old female with end-stage renal disease, was associated with severely atrophic kidneys that contained numerous collapsed and scarred cysts. No hamartomas were present. The patient survived for more than three years following cadaveric renal transplantation.

Adult↗