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J Levine

Publications and source records attributed to J Levine.

At least 199 records · Page 11Linked to original sources
PubMed1990

The role of urea kinetic modeling, TACurea, and Kt/V in achieving optimal dialysis: a critical reappraisal.

The National Cooperative Dialysis Study (NCDS) established the importance of the time-averaged concentration of blood urea nitrogen (BUN) (TACurea) as a determinant of morbidity among patients maintained on hemodialysis. Although urea is not itself toxic, it serves as a surrogate for those low-molecular weight products of protein catabolism that do contribute to uremic toxicity. The NCDS also reported an association between low protein catabolic rates (a measure of dietary protein intake) and increased morbidity, but the validity of this result has been questioned. On the basis of a retrospective re-analysis of the data, Gotch and Sargent have proposed following the normalized whole-body urea clearance, Kt/V, as a more fundamental index of the level of dialytic therapy. In this review, a comparison is made between these two measures of adequate dialysis, namely, midweek predialysis urea concentration and Kt/V. At least for the cellulosic membranes used in the NCDS, they seem to be equivalent. Furthermore, each prescription defines adequate nutrition as a dietary protein intake (DPI) of 1.0 g/kg/d. At this DPI, a time-averaged concentration of BUN of 17.9 mmol/L (50 mg/dL) (corresponding roughly to a midweek predialysis BUN of 21.4 to 28.6 mmol/L (60 to 80 mg/dL), as recommended by the NCDS, is equivalent to a Kt/V of 1.0, as recommended by Gotch and Sargent. Based on ease and accuracy of measurement, TACurea would seem the more reliable marker for monitoring the adequacy of dialysis. Extrapolation of the utility of TACurea and/or Kt/V to noncellulosic membranes remains to be established. Urea kinetic modeling constitutes a powerful mathematical tool for implementing these recommendations. Urea kinetic modeling may also be used as a means of monitoring DPI and thereby ensuring adequate nutrition.

Blood Urea Nitrogen↗
PubMed1990

Continuous versus targeted medication in schizophrenic outpatients: outcome results.

The authors report on the outcome of treatment of 116 outpatients with chronic schizophrenia who were assigned to a 2-year, single-blind course of treatment with either targeted or continuous medication. These patients were not restricted to those who were good candidates for a medication reduction strategy. Continuous medication was superior to targeted medication in preventing decompensations and hospitalizations and in extent of employment at 2 years. Other measures of psychopathology and functioning at 1 and 2 years did not differentiate the two groups of patients. The targeted approach achieved a substantial reduction in total medication through a reduction in the number of days of medication administration.

Adult↗
PubMed1990

The roles of social work in psycho-biological research.

Social Workers have an opportunity to utilize their skills in the arena of psychiatric research. Traditional areas of social work functions, including working with patients, families, groups, complicated systems, and interdisciplinary teams, as advocate, therapist, mediator, and manager, are all necessary for the successful implementation of psychiatric research projects with human subjects. The repertoire of social work skills can enhance the successful operation of research involving bio-psycho-pharmacological or neurobiological trials.

Brain↗
PubMed1990

The relative value of consultation, questionnaires and laboratory investigation in the identification of excessive alcohol consumption.

Alcohol is a major cause of morbidity and mortality in Britain. Consultation, questionnaires and laboratory tests may all be used to help identify alcohol abuse and thereby prevent and treat alcohol-related problems. Consultation which can identify 80% of alcohol abusers involves recording the findings of alcohol and general histories and physical examination. The accuracy of the assessment depends on the reliability of the respondent and the respondent's relations and friends, and on the skill of the investigator; however, thorough assessment is time-consuming and expensive. Questionnaires may identify up to 80% of alcoholics. They are generally based on the Michigan Alcohol Screening Test and CAGE questionnaires and are simple, rapid to complete, inexpensive and not dependent on skilled investigators; however, the principal disadvantage of using questionnaires is that a personal relationship is not developed with the subject. Finally, simple and complex laboratory tests may be used. Of the simple laboratory tests, raised GGT or MCV levels are the most useful and when these values are combined, 90% of alcoholics may be identified correctly. Complex laboratory tests may exhibit greater sensitivity and specificity and provide useful additional information; however, their restricted availability limits their widespread use. The value of each of these methods depends on the objective of the assessment. For population surveys, questionnaires are of greatest relative value and consultation and laboratory tests may be used to confirm the presence of alcohol abuse. In general practice and the hospital setting, it is imperative to include questions on alcohol intake and alcohol-related problems in all interviews with patients. Laboratory tests may be used to confirm suspected alcohol abuse and questionnaires may provide useful screening tools. Finally, in the specialist alcohol unit, consultation, questionnaires and laboratory investigations are all important for identifying alcohol abuse. In this setting, consultation is of particular importance and the alcohol history and physical examination should be recorded by a skilled investigator and the results confirmed with relatives and close friends. Questionnaires are useful as initial screening or assessment tools and computer-based systems may facilitate data collection. Simple and complex laboratory tests may be used to confirm the diagnosis and help ascertain the extent of disease. By assuming that 'all patients have alcohol-related problems until proven otherwise', and through the appropriate application of consultation, questionnaires and laboratory tests, identification of excessive alcohol consumption and the prevention of its sequelae will be facilitated.

Alcoholism↗
PubMed1990

Evidence that the pacemaker controlling activity rhythms is shortened in male thyroparathyroidectomized (TPX) rats: similarities to the effects of estradiol in females.

The experiments described here demonstrate that TPX and TX male rats display shorter free-running activity rhythms and higher activity levels compared to intact males. Neither effect could be duplicated in TPX females. The patterns in activity period, range of entrainment, and levels of activity observed in TPX males closely resembles that reported in intact females or OVX females treated with estradiol. These data suggest the possibility of a common mechanism linking circadian alterations produced by estradiol and thyroid state. This hypothesis needs to be tested, as does the question of whether thyroid hormones or calcitonin are responsible for the TPX and TX results. If thyroid hormones prove to be the causal agents, opposing effects of thyroid hormones and estradiol on adrenergic receptors provide a possible common mode of action for these agents on the circadian system. Disparate results from rat and hamster studies concerning the influence of thyroid state on activity rhythms suggest the possibility of species differences in this level of circadian organization. Thus, caution should be exercised in extrapolating results to other species, including humans.

Activity Cycles↗
PubMed1989

A Tetrahymena intron nucleotide connected to the GTP/arginine site.

We have substituted all nucleotides at intron nucleotide 260 (N260) in transcripts related to the self-splicing Tetrahymena rRNA. Substitution slightly affects the binding and reaction of GTP with this group I catalytic center; kcat/Km varies over a three-fold range. The base of N260 therefore communicates with the rG site, but is unlikely to bond directly to GTP. Different nucleotides at this position also alter the binding of L-arginine to the intron, measured by inhibition of the reaction with GTP. Effects of similar small magnitude on interaction of RNA with both GTP and L-arginine support the previous argument from kinetic and structural comparison (Yarus, M. (1988) Science 240, 1751) that placed the two ligands of the RNA in the same binding site. G260 RNA shows the greatest affinity for both D- and L-arginine, but uniquely lacks stereoselectivity for the amino acid. Therefore G260 alters spatial relations within the G site, otherwise conserved in C260, U260, and A260 RNA's. Guanyl urea was used as a probe for the G/guanidino H-bonding part of the rG/arginine site. G260 RNA's dissociation constant for guanyl urea is similar to that of the other RNA's, suggesting that G260 RNA is unaltered at the G/guanidino end of the rG/arginine binding site. To account for all observations, we suggest that the G260 substitution alters the relative location of the RNA backbone near the 5' exon-intron junction, making this location more flexible and closer to the alpha-NH3+'s of L- and D-arginine.

Animals↗
PubMed1989

Hemodynamic effects on endothelial cell monolayer detachment from vascular prostheses.

The establishment of an early blood-contacting endothelialized surface may improve the graft-host relationship. This study evaluated the adherence of indium 111-radiolabeled endothelial cells that were cultured to confluence on fibronectin-treated polyester elastomer (Hytrel) grafts that were perfused for two hours on a pulse duplicator apparatus under high- and low-shear conditions. Perfusate samples were serially assayed for radioactivity. After perfusion, grafts were sectioned into four segments and assayed for retained radioactivity. All graft segments were hematoxylin stained and examined under light microscopy for evaluation of cell density. Excellent endothelial cell adherence (90%) was observed under both hemodynamic conditions at 120 minutes, with most losses occurring within the first 15 minutes. No differences were seen between high- and low-shear conditions or proximal vs distal graft segments.

Animals↗
PubMed1989

A multicenter, randomized, double-blind trial of somatostatin in the management of acute hemorrhage from esophageal varices.

A prospective, randomized, placebo-controlled, double-blind, multicenter clinical trial of intravenous somatostatin (Stilamin; Serono Laboratories, Inc., Randolph, MA) was performed in 102 patients with actively bleeding esophageal varices from August, 1985, to November, 1986. Patients had major hemorrhage indicated by hematemesis or melena and evidence of significant blood loss. For entry, patients had to have endoscopic demonstration of active bleeding from esophageal varices or stigmata of recent hemorrhage and bright red blood in the gastric aspirate with no other source of bleeding found. Randomized patients received identical-appearing somatostatin or placebo for a 30-hr study period. Those given somatostatin received a 250-micrograms bolus and a 250-micrograms per hr infusion with repeat bolus and doubling of the infusion if the bleeding was not controlled. In retrospect, 18 patients could not be evaluated. Of the 84 evaluable patients, 48 received somatostatin and 36 placebo. They were comparable in age, gender, severity of liver disease and history of variceal bleeding. Transfusion requirements were similar in both groups. Bleeding stopped for 12 consecutive hr during 30 hr of the study period in 31 (65%) of the somatostatin group vs. 30 (83%) of the placebo group (p = 0.06). The median time to cessation of bleeding was 2 hr in the placebo group and 3 hr in the somatostatin group. Deaths following the study period were nine (25%) in the placebo group and 15 (31%) in the somatostatin group. Within the limitations of the present study, we conclude that somatostatin was ineffective in the management of active bleeding of esophageal varices.

Adult↗
PubMed1989

Defensive coping and blood pressure reactivity in medical patients.

Two defensive coping styles, denial of illness and repressive coping, were studied in two groups of medical patients whose blood pressure (BP) was measured during a stress interview. Denial of illness was measured using the Levine Denial of Illness Scale (LDIS), and repressive coping was measured using a combination of the Marlowe-Crowne (MC) Social Desirability Scale and the SCL-90R anxiety subscale (ANX). Consistent with our prior research indicating that LDIS was associated with adaptive outcomes in the short run, high deniers manifested reduced systolic BP reactivity compared to low deniers. Although not related to repressive coping, systolic BP reactivity was correlated positively with MC and ANX separately. The results demonstrate that LDIS and MC measure different types of defensive coping. Current theories of the MC scale suggest two possible interpretations of the MC findings, one that focuses on avoidant coping and the second on attentional coping in high MC scorers.

Adaptation, Psychological↗
PubMed1989

The human immunodeficiency virus rev protein is a nuclear phosphoprotein.

The human Immunodeficiency virus rev protein is one of several key regulatory proteins involved in the control of viral structural protein synthesis and replication. In this report, we identify the 20-kDa rev protein as a nuclear phosphoprotein. Post-translational modification was observed solely on serine residues. In vitro kinase reactions utilizing a derivative of Rev purified from Escherichia coli identified a nuclear kinase capable of phosphorylating exogenously added rev protein. Our results suggest that the nuclear kinase activity observed in vitro is likely to be responsible for the in vivo post-translational modification of Rev.

Animals↗
PubMed1989

Where was Crohn's colitis in 1932?

Crohn's disease first received widespread recognition in the United States as a syndrome involving the terminal ileum in 1932. Within a few years it was recognized that the primary process could involve any part of the ileum and jejunum. It was not until 1965, however, that Crohn's colitis was recognized in the United States. There were many reasons for the delay of nearly 35 years: accounts documenting this affliction from the early part of this century were ignored and Crohn's colitis was confused with other diseases of the large intestine. More important, authorities in the field were skeptical that Crohn's disease involved the colon and failed to investigate fully that possibility. The belief that Crohn's disease stopped at the ileocecal valve was so entrenched in American medicine that after the British first documented Crohn's colitis in 1959, it took doctors in the United States another 6 years to believe it.

Colitis↗
PubMed1989

Isolated dislocation of the radial head.

Isolated dislocation of the radial head without fracture of the ulna is an uncommon injury. Though rare in children, it has been reported. A review of the world literature revealed only two reported cases in adolescents. This paper presents three previously unreported cases and reviews the mechanism of injury and problems associated with delayed treatment.

Accidental Falls↗
PubMed1988

Impending sudden cardiac death: treatment with myocardial revascularization and the automatic implantable cardioverter defibrillator.

Myocardial revascularization and implantation of the automatic implantable cardioverter defibrillator (AICD) have individually been shown to improve survival in patients after sudden cardiac death. Their combined role has not been well defined. Twenty-three survivors of sudden death underwent revascularization and AICD implantation at an average age of 59 years. The initial arrest was caused by ventricular fibrillation in 15 and ventricular tachycardia in 8. Exercise stress tests, ambulatory ECGs, and electrophysiological monitoring with programmed electrical stimulation were done preoperatively and postoperatively. Follow-up averaged 24 months with a two-year survival of 91%. Eight patients (35%) required AICD resuscitation an average of 8 months postoperatively, and electrophysiological testing did not accurately predict arrhythmia recurrence. The addition of AICD implantation to revascularization substantially improves survival of patients with sudden cardiac death.

Adult↗
PubMed1988

A staged approach to long gap esophageal atresia employing a spiral myotomy and delayed reconstruction of the esophagus: an experimental study.

In beagle dogs, the cervical esophagus was divided 5 cm cranial to the thoracic inlet employing a stapler. The distal esophageal stump was attached to the external surface of the trachea. A spiral myotomy (2 1/2 revolutions) was made in a 3-cm long segment constituting the distal end of the proximal esophageal segment. This was twisted on a bias with the muscle edges approximated by interrupted stitches to cover the denuded submucosal layer. With moderate traction, this segment could be elongated to a length of 5 cm. A subcutaneous tunnel was created in the anterior chest to accommodate the reconstructed proximal esophageal segment (under slight traction), with its distal end forming a cutaneous esophagostomy. A gastrostomy was created using a Gauderer button (Bard Interventional Products, Billerica, MA) for feeding. After 3 weeks, the proximal esophageal segment was mobilized and removed from the subcutaneous tunnel. The distal esophageal segment was freed from the trachea and 5 to 8 cm of its proximal end was excised. The proximal (myotomized) esophagus was brought down to the stump of the remaining distal esophagus and an anastomosis formed in an end-to-end fashion. Oral feeding was reestablished within 1 week. Prolonged ingestion, observed soon after operation, gradually improved. During a period of 1 to 6 months after the operation, motility of the myotomized segment was tested by barium swallow and manometry. There was neither diverticulum formation nor stenosis. Transit of contrast material in the myotomized segment was smooth and rapid. Manometry demonstrated preservation of motility in the myotomized segment of the esophagus.(ABSTRACT TRUNCATED AT 250 WORDS)

Anastomosis, Surgical↗
PubMed1988

Increased intrapulmonary retention of radiolabeled neutrophils in early oxygen toxicity.

Sequential lung injuries, such as oxygen toxicity followed by septicemia, are common during the adult respiratory distress syndrome (ARDS). As these forms of vascular injury may be mediated in part by polymorphonuclear leukocytes (PMN), aberrant interactions between PMN and previously injured pulmonary endothelium are of both theoretical interest and clinical importance. The present study was undertaken to test the hypothesis that early oxygen toxicity at a dose that injuries pulmonary endothelium relatively selectively alters intrapulmonary neutrophil kinetics. Unanesthetized rats breathing 1.0 atmospheres oxygen for 36 h showed ultrastructural endothelial damage but no edema, injury, or neutrophilic inflammation by histologic criteria. However, in these oxygen-toxic animals, whereas initial accumulation of radiolabeled PMN in lungs was normal, washout of PMN was abnormal at 120 min after infusion, at which point the pulmonary retention of radiolabeled PMN in the lungs of oxygen-treated animals was significantly higher than in control animals (139% of control, p less than 0.0096). Features of our methodology, including avoidance of osmotic stress and use of paired control animals, appear to have greatly enhanced the sensitivity of radiolabeled neutrophils for detecting a subtle abnormality of neutrophil-endothelial interactions. Our studies in the oxygen toxicity model provide the first demonstration in vivo of abnormal intrapulmonary neutrophil kinetics in early oxygen toxicity prior to the onset of histologic evidence of lung injury or inflammation.

Animals↗