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Biomedical subjects

L Levi

Publications and source records attributed to L Levi.

At least 37 records · Page 2Linked to original sources
PubMed1995

The significance of dorsal migration of the cord after extensive cervical laminectomy for patients with traumatic central cord syndrome.

Central cord syndrome (CCS) resulting from traumatic cervical injury is often associated with cervical stenosis and/or spondylosis. The efficacy of multilevel laminectomy in the treatment of this condition has been controversial. The objective of this study was to validate by magnetic resonance (MR) imaging the occurrence of dorsal cord migration after extensive laminectomy for patients with the clinical syndrome of central cord damage and its relationship to the short-term outcome. During a 28-month period, the authors evaluated 20 patients (mean age 54 years) who sustained CCS after cervical spine trauma. Pre- and postoperative MR imaging assessed the adequacy of cervical cord decompression by multilevel laminectomy. All patients had cervical canal stenosis with complete obliteration of the anterior subarachnoid space over multiple levels. Seventeen patients initially had CCS of different degrees of severity. One had no motor deficit and two had motor complete with sensory deficits greater in their arms. Laminectomy, generally from C2 to C7 without facetectomy, was performed after plateau of neurological recovery (mean 17 days postinjury). Neurological assessment 3 months after operation revealed improvement in 12, stable function in 7, and progression of deficit in one with no mortality. The postoperative midsagittal MR images demonstrated adequate decompression with restoration of anterior cerebrospinal fluid space and posterior cord migration in 12 patients (60% of the 20), but only 8 of them also had improved function. MR imaging demonstrated that, in the presence of multilevel spondylosis/stenosis, laminectomy may provide adequate spinal cord decompression in patients with traumatic CCS.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

[Head injuries from falls in children of 2 ethnic groups].

The highly prevalent problem of falls, the main cause of head injury in children, responds to preventive intervention. To aid in designing fall-prevention programs, we defined the pre- and post-hospitalization characteristics of children of 2 predominant Israeli ethnic groups: Jews (Group A) and non-Jews (Group B). In a prospective study conducted over a 10-month period in our emergency room during the morning shift, data from 274 patients aged 0-14 who presented with head injury due to a fall were collected. In Group B falls and damage were significantly more severe. Based on these differences in injury and in referral patterns between the 2 groups, a high-risk profile for head injury from falls in children was compiled to aid in designing an effective prevention program.

Accidental Falls↗
PubMed1994

The neural locus of binocular rivalry and monocular diplopia in intermittent exotropes.

Patients with intermittent exotropia (strabismus) can either fixate normally or allow one eye to deviate outward by as much as 60 degrees. Two such patients (D.N. and K.C.) were studied and it was found that during eye deviation, binocular correspondence is maintained by completely 'remapping' egocentric space for the deviating eye alone using extraretinal signals from that eye. Also, by using foveal afterimages we showed that binocular rivalry occurs at a site earlier than this egocentric remapping, probably in area 17 itself. And finally, consistent with the neural remapping hypothesis, patient K.C. also experienced monocular diplopia; objects appeared double when viewed with the deviating eye.

Afterimage↗
PubMed1994

A masked prospective evaluation of outcome parameters for cytomegalovirus-related retinal detachment surgery in patients with acquired immune deficiency syndrome.

PURPOSE: The management of cytomegalovirus (CMV)-related rhegmatogenous retinal detachments in patients with acquired immune deficiency syndrome (AIDS) has been the subject of recent attention and controversy because of the high degree of variability in visual outcome, as well as significant differences in the reported incidence of profound postoperative optic atrophy. This study was designed to evaluate the various parameters affecting postoperative visual outcome, and to quantitate the degree of postoperative optic disc pallor. METHODS: The results of 65 consecutive surgeries for CMV-related retinal detachments in 51 patients with AIDS were prospectively studied. Postoperative vision, survival, optic disc pallor, and retinitis extent were analyzed. Serial photographs of optic discs underwent masked evaluation. RESULTS: Mean postoperative survival was 30 weeks (range, 2-146 weeks). Mean best postoperative visual acuity was 20/66 (range, 20/20-2/200) and mean final postoperative visual acuity was 20/100 (range, 20/25-no light perception). Analysis of visual outcome for eyes with no macular or papillo-macular retinitis showed a best postoperative visual acuity of 20/60 (range, 20/25-2/200) and mean final postoperative visual acuity of 20/80 (range, 20/25-no light perception). Postoperative vision was not affected by the presence of a preoperative macular detachment, with both groups (macula on or off detachments), achieving a best postoperative visual acuity of 20/60 in the absence of macular retinitis. Mild postoperative optic disc pallor was observed in 30% of surgical eyes at the final postoperative visit, and moderate pallor was noted in 13%. The mean degree of optic disc pallor was not different from the degree of optic disc pallor seen in fellow, nonsurgical eyes with CMV retinitis (surgical versus fellow nonsurgical eyes, 29% +/- 23% versus 26% +/- 30%; P = 0.64). CONCLUSION: In this largest reported series of reattachment surgery for CMV-related retinal detachments, patients are experiencing increased postoperative survival, good vision, and relative optic nerve health.

AIDS-Related Opportunistic Infections↗
PubMed1993

Cloning of LL5, a novel protein encoding cDNA from a rat pituitary library.

While screening a rat pituitary cDNA library for a peptide hormone receptor, we identified a cDNA that represents a novel gene. The 3.8 kb cDNA has an open reading frame of 2.3 kb encoding a protein of 781 amino acids (M(r) = 87,507). Southern blot analysis of rat, mouse, bovine and human genomic DNAs revealed that a homologous gene is present in these species probably in a single copy. Northern blot analysis showed that in addition to the pituitary gland, the gene is also expressed in other rat tissues. Scanning of DNA and protein databanks revealed no significant homology to any other sequence. Thus, this gene encodes a heretofore unidentified protein.

Amino Acid Sequence↗
PubMed1993

A physiological coma scale: grading of coma by combined use of brain-stem trigeminal and auditory evoked potentials and the Glasgow Coma Scale.

Forty-five comatose patients were prospectively studied by means of clinical examination and evoked potentials. In each patient, clinical data included Glasgow Coma Scale (GCS) score, age, pupillary response to light, corneal reflex, and eye movements. Neurophysiological evaluation was based on brain-stem trigeminal evoked potentials (BTEPs) and brain-stem auditory evoked potentials (BAEPs). For each physiological test, a progressive grading system was designed. This system was based on the evaluation of central conduction times along the trigeminal and the auditory pathways within the brain-stem. The accuracy of the clinical and the neurophysiological indicants in predicting "favorable" or "unfavorable" outcome was assessed singly and in combination. Of the clinical indicants, the GCS provided the most accurate prognosis (80%). Similar results were provided by the BAEP and the BTEP, with significant improvement in the confidence of outcome prediction. No significant difference in the accuracy of outcome predictions could be found between combined clinical data and neurophysiological data. However, the combination of clinical and neurophysiological data markedly increased both the accuracy and the confidence of outcome prediction, reaching 86% correct predictions at the over 90% confidence level with only 2% false pessimistic errors. According to these findings, a clinical-physiological coma scale, the trigeminal-auditory Glasgow (Coma Scale) score (TAG score) was designed. The TAG score demonstrated the highest accuracy at each confidence level as compared to other single indicants. We concluded that the TAG score may improve the evaluation of deep comatose patients and assist the physician in the management of such patients.

Adolescent↗
PubMed1993

Effect of THAM upon outcome in severe head injury: a randomized prospective clinical trial.

Although mortality and morbidity rates from head injury have been reduced substantially by improved prehospital interventions, intensive care, and aggressive management of intracranial pressure (ICP), successful treatment of the primary brain injury has been elusive. In experimental models, tromethamine (THAM) has been effective in treating head injury; this drug acts by entering the cerebrospinal fluid compartment, reducing cerebral acidosis and ICP, and reversing the adverse effects of prophylactic hyperventilation on early recovery. In this randomized prospective clinical trial, THAM was studied to determine if it had beneficial effects in the early management of severe head injuries and if the adverse effects of hyperventilation could be prevented. A total of 149 patients with severe head injury (Glasgow Coma Scale scores of < or = 8) were randomly assigned to either a control or a THAM group. Both groups of patients matched in terms of clinical parameters, including age, sex, number of surgical mass lesions, number in each Glasgow Coma Scale stratum, and first ICP measurement. All patients were treated by a standard management protocol, intubated, mechanically ventilated, and maintained in the pCO2 range of 32 to 35 mm Hg for 5 days. Tromethamine was administered as a 0.3-M solution in an initial loading dose (body weight x blood acidity deficit, average 4.27 cc/kg/hr) given over 2 hours, followed by a constant infusion of 1 ml/kg/hr for 5 days. Outcome was measured at 3, 6, and 12 months postinjury. Although analysis indicated no significant difference in outcome between these two groups at 3 months, 6 months, and 1 year, there was a difference regarding ICP. The time that ICP was above 20 mm Hg in the first 48 hours postinjury was less in patients treated with THAM (p < 0.05). Also, the number of patients requiring barbiturate coma was significantly less in the THAM group (5.48% vs. 18.4%, p < 0.05). The authors conclude that THAM ameliorates the deleterious effect of prolonged hyperventilation, may be beneficial in ICP control, and warrants further study as to the dosage and timing of administration.

Adolescent↗
PubMed1993

Hemodynamic parameters in patients with acute cervical cord trauma: description, intervention, and prediction of outcome.

The cardiovascular response of the patient with acute spinal cord injury (SCI) is known to be altered secondary to the cord injury. Our current protocol of managing the acute phase of patients with SCI includes invasive hemodynamic monitoring (with arterial line and Swan-Ganz catheter) and support with fluids and dopamine and/or dobutamine, titrated to maintain a hemodynamic profile with adequate cardiac output (to be determined by oxygen consumption and delivery) and a mean blood pressure of > 90 mm Hg. We feel that this protocol provides two benefits: 1) maintaining the mean blood pressure improves the morbidity of these patients by deterring ischemia and accompanying secondary insults; 2) aggressive monitoring and hemodynamic intervention help stabilize the hemodynamic status of these patients and make it possible to consider early surgery in selected cases. Our hypothesis is that the pulmonary vascular bed is more sensitive to the sympathectomized effect of acute complete cervical SCI. We analyzed the demographic, neurologic, and hemodynamic data of 50 consecutive patients during their first week postinjury. All had signs of myelopathy; 31 (62%) were considered clinically complete. Of the 50 patients, 9 (18%) died, 20 did not improve functionally, and 21 improved. The mean heart rate (82.1 +/- 13.3), blood pressure (94.4 +/- 9.4), pulmonary artery pressure (22 +/- 5) and wedge (12.7 +/- 3.4), cardiac index (4.5 +/- 0.9), systemic vascular resistance index (SVRI) (1637 +/- 399), pulmonary vascular resistance index (PVRI) (181 +/- 80), and oxygen transport (694 +/- 156) showed good response to the treatment. Because the measurements were obtained during treatment, they differ from the expected "classic sympathectomized" response, but they provide a database for further analysis of hemodynamic manipulation in SCI. An analysis of the hemodynamic parameters did not differentiate between complete and incomplete lesions or between patients with functional improvement. We determined, on the basis of the initial hemodynamic measurements, that no patient with a clinically complete motor deficit (Frankel Grade A+B) improved of the 10 who had measurements compatible with either: 1) PVRI < 100 with SVRI < 1200; or 2) PVRI < 115 with SVRI < 1300 or PVR/SVR ratio of < 0.08 when SVRI was < 1600. These patients could not have other measurements that showed low SVRI < 1350 with PVRI > 139. At odds with this unique group, 13 of 29 patients with the same clinical picture and without the above physiological criteria of severe hemodynamic deficit eventually improved (P < 0.05).(ABSTRACT TRUNCATED AT 400 WORDS)

Acute Disease↗
PubMed1993

Conditions of life, life-styles, and health in a highly developed country.

Psychosocial stressors originate in social structures and processes, affect the human organism through psychological processes, and influence health through four types of closely interrelated mechanisms--emotional, cognitive, behavioral, and physiological. The health outcome is modified by situational (e.g., social support) and individual factors (e.g., personality, coping repetoire). The social environment-stress-health system is a dynamic one with many feedback loops. There is increasing evidence of a causal relationship between psychosocial stressors and morbidity and mortality in a population. Although most of the data presented in this paper are based on Swedish conditions and Swedish studies, some evidence is reviewed indicating their increasing applicability to, and relevance for, Japan. Research and health action should aim at being system-oriented, interdisciplinary, intersectorial, health (and not only disease) oriented, and participative.

Health↗
PubMed1992

Synthesis of a conjugate vaccine composed of pneumococcus type 14 capsular polysaccharide bound to pertussis toxin.

Type 14 is one of the common types isolated from patients of all ages with infections caused by Streptococcus pneumoniae. Its capsular polysaccharide (Pn14) is composed of a neutrally charged tetrasaccharide repeat unit. Pn14 does not elicit protective levels of antibodies in infants and children and is a less than optimal immunogen of the 23-valent vaccine for adults. Pertussis toxin (PT) is both a virulence factor and protective antigen of Bordetella pertussis: it is not soluble at neutral pH and forms insoluble complexes with acidic polysaccharides. Both Pn14 and PT are potential components of vaccines for infants and children. Accordingly, a synthetic scheme was devised to prepare a conjugate of Pn14 and PT. An adipic acid hydrazide derivative of Pn14 was bound to PT at pH 3.9 by carbodiimide-mediated condensation. The conjugation procedure inactivated the PT as assayed by CHO cell and histamine-sensitizing activity. The Pn14-PT conjugate elicited antibodies in mice to Pn14 at levels estimated to be protective in humans and elicited neutralizing antibodies to PT. We plan to evaluate Pn14-PT clinically.

Animals↗
PubMed1991

The use of anterior Caspar plate fixation in acute cervical spine injury.

Optimal management of cervical cord injury in the presence of documented instability and/or compression of neural elements remains a controversial topic. Surgery and internal stabilization of cervical spine fracture/dislocations are effective and well accepted, but controversy exists on the relative merits of the anterior versus the posterior approach as well as the optimal timing of surgical intervention. We report our experience with the Caspar technique and instrumentation for anterior stabilization in 54 patients for acute cervical spine injury. Our series consists of 38 male and 16 female patients whose ages ranged from 16 to 68 years, with a mean age of 29.2 years. Thirty-two of these patients had complete neurological sensory/motor deficits at the time of presentation, eight were neurologically intact, and 14 had preservation of some motor and sensory function. All 54 patients had radiographic evidence of posterior instability as well as anterior disruption of either a vertebral body or intervertebral disk. We found that "early" intervention (less than 24 hours after injury) was performed frequently in the neurologically compromised patients. Twelve of the 22 patients undergoing surgery less than 24 hours after admission regained significant neurological function, with 13 of 22 developing postoperative complications. In the "delayed" group (surgery more than 24 hours after injury, mean 14.3 days), 14 patients experienced postoperative complications, with 15 of 24 demonstrating neurological improvement. The eight patients who were intact did uniformly well. There was no mortality during the follow-up. All 54 patients showed a solid fusion (clinically and radiologically) within 6 months of surgery. In two cases the plates had to be removed, without risking the fusion. Our experience suggests that although anterior cervical fusion and Caspar plating remain appropriate for patients with documented anterior compromise of the canal, it should not substitute for more traditional posterior stabilization procedures. Because this route has the potential for more serious complications, it should be reserved for the cases in which anterior decompression is deemed necessary or posterior fusion was unsuccessful. With appropriate selection of patients, no adverse effect of early surgery was demonstrated. In fact, neurologically compromised patients had the benefits of increased ease of patient care and early transfer to rehabilitation.

Adolescent↗
PubMed1991

Clinical and immunologic responses to Haemophilus influenzae type b-tetanus toxoid conjugate vaccine in infants injected at 3, 5, 7, and 18 months of age.

The safety and immunogenicity of Haemophilus influenzae type b-tetanus toxoid conjugate vaccine (Hib-TT) were evaluated in 77 healthy infants receiving injections at 3, 5, 7, and 18 months of age. No serious local or systemic reactions were noted. After the first injection the geometric mean Hib antibody level rose to 0.55 micrograms/ml, and each subsequent injection elicited a statistically significant rise in the geometric mean. The percentage of vaccinees with Hib antibody levels greater than 0.15 micrograms/ml serum was 75.5% after the first, 97.4% after the second, and 100% after the third Hib-TT injection. This percentage fell to 90.9% at 18 months of age but rose again to 100% after the fourth injection. Control infants (n = 10) injected with diphtheria-tetanus toxoid-pertussis vaccine only had nondetectable levels after the second injection. Hib-TT elicited increases of Hib antibody in all isotypes: IgG greater than IgM greater than IgA. Among IgG subclasses the highest increases were of IgG1. All vaccinated subjects had greater than 0.01 U/ml of TT antibody (estimated protective level) throughout the study. We conclude that Hib-TT, injected at 3, 5, 7, and 18 months, is safe and induces protective levels of antibodies during the age of highest incidence of meningitis caused by Hib.

Antibodies, Bacterial↗
PubMed1991

Neuroendocrine and immunologic effects of unemployment and job insecurity.

We prospectively followed a cohort of 354 blue-collar men and women, some of whom lost their jobs. Results show marked effects during the anticipatory and early unemployment phase on mental well-being, serum cortisol, prolactin, total cholesterol, HDL cholesterol, and phytohemagglutinin reactivity of lymphocytes. Most of these changes appear to be of short-term duration. However, changes in cardiovascular risk factors are observed at least 2 years following the loss of one's job. Coping style appears to be a major determinant whether or not and how people will react to unemployment.

Adaptation, Psychological↗