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Biomedical subjects

S Levine

Publications and source records attributed to S Levine.

At least 343 records · Page 19Linked to original sources
PubMed1985

Nucleotide sequence of the G protein gene of human respiratory syncytial virus reveals an unusual type of viral membrane protein.

The major surface glycoprotein (G) of human respiratory syncytial (RS) virus has an estimated mature Mr of 84,000-90,000. Among a library of cDNA clones prepared from RS virus mRNAs, we identified clones that hybridized to a message that encoded a Mr 36,000 polypeptide that was specifically immunoprecipitated with anti-G antiserum. The amino acid sequence of the G protein backbone was determined by nucleotide sequence analysis of several of the cDNA clones. It contains a combination of structural features that make it unique among the known viral glycoproteins. The G mRNA is 918 nucleotides long and contains a single major open reading frame that encodes a polypeptide having 298 amino acid residues with a Mr of 32,587, a finding consistent with the Mr 36,000 estimate for the in vitro translation product of the G mRNA. This suggests that greater than 50% of the molecular weight of the mature glycoprotein may be contributed by carbohydrate. Glycosylation of G is largely resistant to tunicamycin, an inhibitor of the attachment of N-linked oligosaccharides, suggesting that the majority of the carbohydrate residues are attached via O-glycosidic bonds. In accordance with this, serine and threonine residues, the acceptor sites for O-linked oligosaccharides, comprise 30.6% of the total amino acid composition. There are also four potential acceptor sites for N-linked oligosaccharides. The amino acid sequence lacks both an NH2-terminal hydrophobic signal sequence and a COOH-terminal hydrophobic region. Instead, a strongly hydrophobic region is located between amino acid residues 38 and 66. This region may serve as both the signal to insert the nascent polypeptide through the membrane and as the membrane anchor site.

Amino Acid Sequence↗
PubMed1985

Quality of life and the patient's response to treatment.

Quality of life resides mainly in an individual's satisfaction with his role at work, at home, and in his community. Illness and treatment affect quality of life to the extent that they damage an individual's ability to perform these roles to his own satisfaction. Clinicians will increasingly have to take account of quality of life in assessing the effect of an illness and of their treatment for it. This is particularly so in chronic diseases for which there is no "cure" and in asymptomatic conditions, such as hypertension.

Antihypertensive Agents↗
PubMed1985

Respiratory syncytial virus polypeptides. IV. The oligosaccharides of the glycoproteins.

The cell-associated glycoproteins of respiratory syncytial (RS) virus included GP1 (90K), VP70 (70K), VGP48 (48K) and GP26 (26K). Although present in infected cells, there was no VP70 in purified virus. Trypsin treatment of infected cells removed 80 to 90% of VP70 as well as its products VGP48 and GP26. This suggested that most of the VP70 in the cell is located on the plasma membrane. The glycoproteins of purified RS virus (GP1, VGP48 and GP26) contain mannose, galactose and fucose as well as glucosamine, but the quantity of mannose in GP1 is low when compared to that of the other three sugars. The effects that follow the treatment of infected cells with the glycosylation inhibitors tunicamycin and monensin, and the treatment of the immunoprecipitated product of pulse-chase experiments with endonuclease H demonstrated that VP70 and its products contained N-linked oligosaccharides, and that the oligosaccharides of the mature VGP48 subunit were of the complex type, while GP1 contained both N- and O-linked oligosaccharides. The non-glycosylated forms of VP70 and GP1 have estimated mol. wt. of 50K and 33K respectively. Therefore, the carbohydrate contribution to the mol. wt. of VP70 and GP1, as determined by PAGE, was equivalent to 20K for the former and 57K for the latter. The majority of the GP1 oligosaccharides were O-linked, a form of sugar linkage not previously found among paramyxoviruses.

Asparagine↗
PubMed1985

Respiratory syncytial virus polypeptides. V. The kinetics of glycoprotein synthesis.

The cell-associated glycoproteins of respiratory syncytial virus included GP1 (90K), VP70 (70K), VGP48 (48K) and GP26 (26K). The time course of virus protein synthesis in HeLa cells revealed that the nucleocapsid protein (VPN41) was the first to appear at 11 h post-infection followed by the appearance of the other viral proteins at 16 h post-infection. Pulse-chase experiments with [3H]leucine or [35S]methionine demonstrated that the precursor for VGP48 and GP26 was an uncleaved protein of 70K (VP70) which required at least 30 min to chase into its final products, while the precursor for GP1 was a glycoprotein of 46K, and also required at least 30 min to chase into GP1. Trypsin treatment of monensin-treated infected cells suggested that VP70 can be cleaved intracellularly into its products VGP48 and GP26.

Electrophoresis, Polyacrylamide Gel↗
PubMed1985

Histologic changes in skin implanted into the larynx and trachea by myocutaneous flap reconstruction.

Skin is the tissue most readily available for relining the walls of the reconstructed larynx or trachea. Its use has been condemned in the past because of potential contracture, complications have occurred when free, split-thickness grafts were used. We studied the changes that develop within skin that is transferred into the lumen of the airway as part of a vascularized sternohyoid myocutaneous flap. Twenty-one dogs underwent reconstruction of laryngotracheal defects by a vascularized myocutaneous flap. The closely shaved and chemically depilated skin included in this reconstruction was ultimately found to be well healed to the adjacent mucosa. Flaps as large as 8 cm2 survived with no evidence of scaling, crusting, or contracture. The cutaneous appendages in the flaps were compared with those found in adjacent skin near the donor site. After proper depilation there was involution of cutaneous appendages. Scarring of the dermis appeared to add support to the grafts. Our findings demonstrate that the rotary door sternohyoid myocutaneous flap is a reliable, well-vascularized flap that can have extensive application in laryngotracheal reconstruction.

Animals↗
PubMed1985

Postinflammatory increase of pathogenicity of lymphocytic inocula in the peritoneal cavity.

Passive transfer of experimental allergic encephalomyelitis in rats by intraperitoneal injection of cells from draining lymph nodes was usually unsuccessful unless very large numbers of cells or conditioning procedures were employed. If the ip injection was done during the healing phase of a chemical peritonitis, then its effectiveness was greatly increased, even exceeding that of the iv route. The same effect of a healing chemical peritonitis was observed in adrenalectomized rats. A regional graft-versus-host disease produced by ip injection of parental spleen cells into hybrid recipients was greatly augmented in the healing phase of a chemical peritonitis. A host-versus-graft reaction against allogeneic spleen cells was histologically detectable only when the cells were injected after a chemical peritonitis. All these results are explicable as the consequence of a postinflammatory increase of absorption of lymphocytic inocula into the draining lymph nodes. The production of a chemical peritonitis is likely to be useful wherever immunologic and pathologic experimentation requires ip inoculations.

Animals↗
PubMed1985

Obtaining consent for organ donation.

The medical, emotional, and legal environments in which consent for organ donation is pursued greatly influence the outcome of this request. Knowledge of the circumstances and facts regarding brain death are important first steps in resolving misconceptions a potential donor's family may have that might preclude a favorable decision. The attitudes of hospital staff members toward these issues, and the grief and shock experienced at these times by next-of-kin, further complicate the circumstances in which consent for organ donation is requested. Clarification of traditional religious beliefs and reconciliation of these with the concept of organ donation may also have to be addressed at this time. Significant benefit to the bereaved family as well as to the transplantation process can accrue only in an atmosphere in which all involved understand the facts of brain death, and in which organ donation is viewed positively.

Attitude of Health Personnel↗
PubMed1985

Thermal injury and induced thermotolerance in rat lymph nodes.

Immersion of the rat's hind limb in water at 45 degrees or 46 degrees C for one hour caused a severe burn of the extremity, including the popliteal lymph node. Pretreatment one day in advance at 45 degrees C for 15 minutes or 43 degrees C for one hour prevented most of the damage to lymph node and other tissues. The production of both thermal necrosis and thermotolerance were direct effects of heat on the lymph node. The distribution of necrosis in the lymph node (greatest in the subcapsular region and least in the medulla) probably relates to thermal gradients and not to the microstructure of the nodes, except perhaps for relative resistance of the medulla.

Animals↗
PubMed1985

Clinical assessment of accommodative facility in symptomatic and asymptomatic individuals.

Clinical assessment of accommodative facility, using +/- 2.00 diopter flippers monocularly, was performed in asymptomatic and symptomatic populations in either single test sessions or multiple daily test sessions. In single session results, there was a trend for the average accommodative flipper rate to decrease as symptom level increased. The cut-off symptomatic/asymptomatic accommodative flipper rate was about 11 cycles per minute. In multiple session results, the average accommodative flipper rate, independent of symptom level, took approximately one week to asymptote to a stable level, with performance remaining at this level two weeks after termination of daily test sessions. Variability in daily flipper rate increased as symptom level increased. These results demonstrate the clinical usefulness of the +/- 2.00 diopter monocular flipper test in the screening for accommodative dysfunction.

Accommodation, Ocular↗
PubMed1984

Effect of fetal intravascular 4-aminoantipyrine infusions on myometrial activity (contractures) at 125 to 143 days' gestation in the pregnant sheep.

Myometrial activity of low amplitude and long duration--contractures--is present throughout gestation in the pregnant ewe and other species. This activity differs from the contractions of labor and delivery. Between 125 and 143 days' gestation, 4-aminoantipyrine infused into the fetus at rates that produced maternal uterine vein plasma concentrations of 4-aminoantipyrine of 5.95 +/- 1.23 (mean +/- SEM, n = 5) mg X 100 ml-1 markedly depressed both total myometrial electromyographic activity to 28.6% and frequency of contractures to 30.5% of preinfusion values. By 60 minutes of infusion, maternal uterine vein plasma 13,14-dihydro-15-keto prostaglandin F2 alpha concentration was reduced to 14% of the resting level. Two conclusions were drawn from this study. First, prostaglandins are involved in the regulation of contractures. Second, when infusions of 4-aminoantipyrine are used to quantify uterine or umbilical blood flow, the possibility exists that changes will occur in physiologic systems that are modified by prostaglandins.

Ampyrone↗
PubMed1984

Effects of social experience on the corticosterone response of adult rats to pup cues.

Rat mothers whose pups have been removed show greater plasma corticosterone elevations when the pups are shocked and returned in a wire-mesh basket than when only the wire basket is returned. For mothers housed with an adult male or virgin female, this differential adrenocorticoid responsiveness between the shocked-pup and empty-basket conditions was not observed unless the adult partner was removed 18 hr before testing. Nonlactating adults housed with pups and mother for up to 2 weeks exhibited corticoid elevations equivalent to the shocked-pup and empty-basket conditions whether tested with the mother or 18 hr after her removal. These results indicate that the differential pituitary-adrenal responsiveness that female rats show to pup cues during lactation cannot be accounted for by the length of the mother's exposure to pups, and, further, that this relative responsiveness during lactation appears to be largely due to the suppression of adrenocorticoid reactivity to a nonsocial environmental disturbance.

Animals↗
PubMed1984

Essential fatty acid deficiency: a suggestion concerning experimental design.

In experiments on essential fatty acid deficiency, various strategems have been used to balance the deficient and control groups for all nutrients except essential fatty acids. We suggest the use of a single fat-free diet for both groups, with essential fatty acids administered parenterally to the control (nondeficient) group once each week.

Animals↗
PubMed1984

Treatment of experimental allergic encephalomyelitis with myelin basic protein: which route is best?

When myelin basic protein (BP) has been used for the treatment of multiple sclerosis (MS), it has been injected intramuscularly (IM) or subcutaneously (SC). Experimental allergic encephalomyelitis (EAE) is widely used as a model for MS, and the use of BP for MS is based on its efficacy in EAE. The present work shows that BP is more effective in EAE when administered by intravenous (IV) route than by IM or SC routes. These observations may be pertinent to therapeutic trials in MS.

Animals↗
PubMed1984

Facial EMG activity levels predict treatment outcome in depression.

Higher electromyographic (EMG) activity levels of corrugator and zygomatic face muscles have been reported to be pretreatment predictors of better clinical outcome in depressed patients. We tested this possibility in 29 drug-free, rigorously diagnosed subjects by measuring low-level EMG activity of corrugator and zygomatic muscles during resting and three imagery states (happy, typical day, sad). All patients had major depressive disorder, endogenous subtype. Good responders had significantly higher pretreatment EMG zygomatic values and different EMG profiles. Our findings replicate and expand prior reports.

Amitriptyline↗
PubMed1984

Choroid plexus thrombosis and hemorrhage caused by disseminated intravascular coagulation in Down's syndrome.

This report concerns an unusual case of thrombosis and hemorrhage in the choroid plexus caused by disseminated intravascular coagulation (DIC). The case is of special interest because it occurred in a patient with Down's syndrome. Nevertheless, there is no causal relation between Down's syndrome and the choroid plexus lesion except that mongols are susceptible to infections that trigger DIC. The association of choroid plexus thrombosis-hemorrhage and Down's syndrome is coincidental and does not indicate a basic vascular defect.

Adolescent↗