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S W Levin

Publications and source records attributed to S W Levin.

13 recordsLinked to original sources
PubMed1993

Amino acid composition and N-terminal sequence of purified cystine binding protein of Escherichia coli.

Cystine Binding Protein (CBP), a commercially available crude protein extract obtained by osmotic shock of Escherichia coli (E. coli), was studied to characterize further its cystine binding properties and to elucidate its cystine transport activity. We report here the amino acid composition, the N-terminal amino acid sequence analysis and some binding characteristics of the purified cystine binding component of CBP. A search of the Swiss-Prot version 20 data base revealed that this sequence is unique.

Amino Acid Sequence↗
PubMed1992

Terminal transverse limb defects associated with familial cavernous angiomatosis.

Terminal transverse limb defects rarely are reported as familial. Multiple pathogenetic mechanisms, including vascular disruption, have been proposed to account for these defects. We report on a family followed over the past 6 years known to have familial cavernous angiomatosis in which 2 relatives have similar terminal transverse defects at the mid-forearm. Multiple relatives have had episodic bleeding from intracranial cavernous angiomas, a distinct finding in this disorder. Other findings in this family include retinal cavernous angiomas (2 patients), a high incidence of skin angiomas (12 patients), cavernous angiomas of the soft tissue (2 patients), and a hepatic angioma (one patient). One of the 2 individuals with the limb defect was evaluated extensively. Magnetic resonance imaging of the forearm with the terminal transverse defect using gadolinium-DTPA enhancement showed abrupt termination of all structures distal to the normal radial and ulnar heads. We propose that familial cavernous angiomatosis may be a new cause of vascular disruption resulting in terminal transverse limb defects.

Adolescent↗
PubMed1990

Acrofacial dysostosis with ambiguous genitalia.

We report on a 46,XY infant with mandibulofacial dysostosis, preaxial and postaxial limb anomalies, urethral stenosis with left hydronephrosis, and ambiguous genitalia with phallic/scrotal transposition. This infant with atypical pre/postaxial acrofacial dysostosis (AFD) is the first to be reported with ambiguous genitalia. The acrofacial dysostoses are a heterogenous group of disorders characterized by varying degrees of mandibulofacial dysostosis with acral limb defects and may represent a polytopic field defect. These disorders have generally been separated on the basis of their limb anomalies into preaxial, postaxial, lethal, and atypical types. Most cases are sporadic, but various causes have been postulated including autosomal dominant and recessive inheritance, a chromosome 2q duplication, and a possible case of diabetic embryopathy. We review the nonfacial/limb anomalies in other cases of AFD and compare them to those of our case, thereby expanding the spectrum of anomalies in these disorders.

Abnormalities, Multiple↗
PubMed1989

Proteus syndrome.

The term Proteus syndrome was coined in 1983 to describe a disorder of skeletal, hamartomatous, and other mesodermal malformations. The syndrome was named after the Greek god Proteus, whose name means "the Polymorphous." Clinical features of this new syndrome are currently being defined. Including the case reported herein, we have found 34 patients with Proteus syndrome described in the English literature. Major clinical findings, defined as those findings seen in more than half of the cases, include hemihypertrophy, macrodactyly, exostoses, epidermal nevi, characteristic cerebriform masses involving the plantar or palmar surfaces, a variety of subcutaneous masses, and scoliosis. Histologic examination of subcutaneous masses has identified a variety of lipomatous, hamartomatous, and angiomatous tumors.

Abnormalities, Multiple↗
PubMed1987

Inhibition of thrombin-induced platelet aggregation by uteroglobin.

Uteroglobin, a steroid-dependent, small molecular weight (15K) protein in the rabbit, inhibited thrombin-induced aggregation of both rabbit and human gel-filtered platelets (GFP). GFP aggregation by arachidonic acid was not affected by uteroglobin. There were no effects of uteroglobin on thrombin-induced clotting of plasma or purified fibrinogen, or inhibition of thrombin by antithrombin III. Additionally, preliminary results suggest that uteroglobin does not interfere with binding of thrombin to platelets. We suggest that inhibition of platelet aggregation by uteroglobin may function in preventing thrombosis and ensuring free flow of blood through the microvasculature of the uterus and the placenta and may induce some of the antimotility effects of progesterone on the uterus.

Animals↗
PubMed1986

Uteroglobin inhibits phospholipase A2 activity.

Although progesterone is known to produce quiescence in the mammalian uterus, the mechanism of this effect is not clearly understood. Here, we report that uteroglobin, a progesterone-induced small molecular weight (16K) protein, inhibits phospholipase A2(PLA2) derived from porcine pancreas as well as from the RAW 264.7 macrophage cell line. We speculate that progesterone may exert its antimotility effects on the uterus via uteroglobin which, by inhibiting PLA2, decreases arachidonic acid release and subsequently reduces prostaglandin levels in this organ. This may explain why progesterone is so vital for the maintenance of pregnancy in almost all mammals.

Animals↗
PubMed1985

Intrauterine growth retardation induced by thiamine deficiency and pyrithiamine during pregnancy in the rat.

The role of nutritional factors in the development of prenatal and postnatal growth retardation is not well understood. We tested if thiamine deficiency may cause intrauterine growth retardation in rats. From the second day of gestation Sprague-Dawley rats were freely fed either a nutritionally complete or a thiamine-deficient diet. A similar group of rats was pair-fed with a complete or a thiamine-deficient diet and daily pyrithiamine injections (50 micrograms/100 gm of body weight) were given to precipitate thiamine deficiency during the short gestation of the rat. Maternal thiamine levels in blood and brain tissues, maternal erythrocyte transketolase activity with thiamine pyrophosphate effects, and fetal tissue thiamine levels were measured. The results indicate that feeding a thiamine-deficient diet in conjunction with pyrithiamine injections caused sufficient thiamine deficiency to induce intrauterine growth retardation in the progeny. We conclude that thiamine deficiency alone during in utero development in the rat may contribute to intrauterine growth retardation.

Animals↗
PubMed1985

Intrauterine growth retardation caused by dietary biotin and thiamine deficiency in the rat.

The effects on fetal development of maternal biotin deficiency, alone and in conjunction with thiamine deficiency, were investigated in rats. Fetuses from dams given biotin-deficient diet throughout gestation demonstrated only some characteristics of intrauterine growth retardation (IUGR) including abnormal liver weight and a higher brain/liver ratio. However, fetuses from dams given biotin-thiamine-deficient diet and daily pyrithiamine (a thiamine antagonist used to insure thiamine deficiency) injections demonstrated severe IUGR along all of the fetal parameters investigated. We conclude that biotin and thiamine deficiency during intrauterine growth of the fetus may be partially responsible for the development of IUGR, a frequent concomitant of fetal alcohol syndrome.

Animals↗
PubMed1984

Balanced rearrangement of chromosomes 2, 5, and 13 in a family with duplication 5q and fetal loss.

We have studied a family in which a mother and daughter (the proposita) had the karyotype 46,XX,ins(2;5),t(5;13). The mother had four spontaneous abortions, a mentally retarded son with duplication (5q), and a daughter who died at 3 months. The proposita had a phenotypically abnormal abortus. Rearrangements involving several chromosomes are very rare. Observations on this family are consistent with the predicted high likelihood of reproductive loss.

Abnormalities, Multiple↗
PubMed1980

Improved stop-flow apparatus to measure permeability of human red cells and ghosts.

An improved stop-flow apparatus has been designed and constructed to measure the permeability characteristics of human red cells, which can be inferred from the time course of red cell volume changes following a sudden change in cellular environment produced by a raped mixing device. The improved apparatus is directly coupled to a computer which automates the subtraction and averaging procedures that have been developed to minimize the noise generated in the system by the cessation of red cell forward motion when the flow is suddenly stopped. Real time data acquisition also makes it possible to increase the number of data points by an order of magnitude, thus improving accuracy significantly. The apparatus has been tested by measurements of the human red cell hydraulic permeability coefficient. Data are presented to validate the subtraction procedure. Experiments have also been carried out on red cell ghosts which indicate that the hydraulic conductivity of the ghost is similar to that of the undisturbed red cell.

Adult↗
PubMedDate not supplied

Human leg heating using a mini-annular phased array.

The energy deposition pattern within an isolated human leg heated with a mini-annular phased array (MAPA) hyperthermia applicator has been determined. The non-tumor-bearing lower portion of a human leg amputated at the hip due to the presence of a large tumor in the thigh was "fixed" in a 50% ethanol in 0.9% saline solution. Subsequent to this fixation process, the leg was rehydrated in 0.9% saline and heated four times using a MAPA operating at 122 MHz. Specific absorption rates and electric field strengths were calculated from the rates of change of temperature with time measured at 143 different anatomical locations within the leg. When the leg was coaxial with the MAPA and the MAPA was axially positioned midway between the knee and the ankle, the points of maximum heating were skewed away from the center of the MAPA, towards the ankle of the leg and along the central axis of the MAPA. Significant temperature rise was measured inside the bone and the fat as well as inside the muscle of the leg. Bone heating was reduced when the leg was shifted away from the MAPA axis.

Amputation, Surgical↗
PubMedDate not supplied

Duplication of the pituitary gland as shown by MR.

Duplication of the pituitary gland is a rare malformation. The authors describe a patient with features of the median cleft face syndrome (hypertelorism, V-shaped hairline, and developmental delay) who exhibited duplication of the pituitary gland and diffuse thickening of the hypothalamus (hypothalamic hamartoma) as shown by MR. The embryology of the developing pituitary gland and pathogenesis of pituitary duplication are discussed.

Child, Preschool↗