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Biomedical subjects

M Stein

Publications and source records attributed to M Stein.

At least 73 records · Page 4Linked to original sources
PubMed1999

Infection by different HIV-1 subtypes (B and C) results in a similar immune activation profile despite distinct immune backgrounds.

We compared the immune activation profile of 46 HIV-negative and 75 HIV-positive Israelis infected with HIV-1 subtype B, with 85 HIV-negative and 102 HIV-positive Ethiopian immigrants to Israel, who were infected with HIV subtype C. The HIV-negative Ethiopians had exceedingly high blood levels of eosinophils, immunoglobulin E (IgE), and p75s tumor-necrosis factor receptors (p75sTNFR); secretion of interleukin-4 (IL-4) and IL-10 by peripheral blood mononuclear cells (PBMC); proportion of human leukocyte antigen (HLA)-DR+ cells within CD3+, CD4+, and CD8+ T-cell subsets; and proportion of CD45RO+ CD4+ cells; while having significantly lower secretion of interferon-gamma (IFN-gamma) by PBMC and percentage of CD45RA+ CD4+ and CD28+ CD8+ cells. HIV infection in both populations was associated with reduced IL-2, IL-4, IL-10, and IL-12 secretion, number of CD28+ and CD45RA+ CD8+ cells, and increased number of HLA-DR+-CD3+, CD4+, and CD8+ cells, and CD45RO+ CD8+ cells. Thus, infection with HIV-1 subtypes B and C of studied Israelis and Ethiopians, respectively, results in a similar immune activation profile at all stages of the infection when living in the same environment, despite the striking different immune profile observed in the HIV-negative Israeli and Ethiopian populations. Together with our previous observations, this indicates that HIV subtype is not a major determinant in the natural course of HIV infection.

Antigens, CD↗
PubMed1999

Characteristics of nasal airflow and the effect of a nasal dilator in normal human subjects.

Nasal resistance contributes to negative airway pressure during breathing. We sought to define normal patterns of nasal flow and the effects of mechanical dilatation and splinting of the nares on flow during forced inspiration and expiration. Maximal inspiratory and expiratory flow volume loops (FVL) were determined in 17 normal subjects. Oral FVL were obtained with nares clamped and nasal FVL through a mask with and without dilatation of nares using a plastic splint (Nozovent). Oral FVL were normal in all. Two patterns of nasal FVL were observed: one indicating 'variable' extrathoracic obstruction, the other indicating 'fixed' extrathoracic obstruction. Maximal inspiratory flow at 50% of vital capacity (FiF50) was improved by the Nozovent only in those with a 'variable' pattern (FIF50 (L/sec): 1.54 +/- 0.3 to 2.86 +/- 0.5; P < 0.05, versus 1.92 +/- 0.3 to 2.21 +/- 0.3: P = 0.5). In subjects with a fixed pattern, failure of dilatation of the nares to increase flow suggests that the site of inspiratory flow limitation is within the bony nostril.

Adult↗
PubMed1999

Dissection of an iliac artery conduit to liver allograft: treatment with an endovascular stent.

Hepatic artery thrombosis remains one of the most serious complications after orthotopic liver transplantation. Sepsis, biliary leakage and strictures, and retransplantation are often the result of this devastating complication. Because retransplantation or reoperation is sometimes not possible or advisable, other means of reestablishing hepatic artery continuity are desirable. We describe a liver transplant recipient who developed a dissection of an iliac artery conduit after retransplantation that was treated with fibrinolytic therapy followed by successful placement of an endovascular stent.

Adult↗
PubMed1999

Aortic regurgitant flow by color Doppler measurement of the local velocity 7 mm above the leak orifice--Part 2: Comparison with cardiac catheterization.

AIMS: An in vitro study of the flow convergence region in aortic regurgitation has shown that regurgitant flow rate can be derived from the local velocity V(7 mm) at 7 mm distance above the leak orifice. This clinical study was performed to test this method in patients. METHODS AND RESULTS: In 67 patients with aortic regurgitation, the flow convergence region was imaged by color Doppler. By analogy with the afore mentioned in vitro study, velocity profiles of the acceleration across the flow convergence region were read from the color maps. The profiles were fitted by using a multiplicative regression model. The V(7 mm) was read from the regression curve, and instantaneous regurgitant flow Q was derived from the V(7 mm) with the equation developed in vitro (Q = V(7 mm).cm2/0.28). Q showed a close association with the angiographic grade. Q-derived regurgitant stroke volume correlated significantly with invasive measurements by the angio-Fick method (r = 0.897, SEE = 19.9 ml, y = 0.88x + 5.9 ml). CONCLUSIONS: Within the color Doppler flow convergence region of aortic regurgitation, the local velocity at 7 mm distance to the leak reflects regurgitant flow rate.

Adult↗
PubMed1999

Orientation-selected ENDOR of the active center in Chromatium vinosum [NiFe] hydrogenase in the oxidized "ready" state.

Electron nuclear double resonance (ENDOR) was applied to study the active site of the oxidized "ready" state, Ni(r), in the [NiFe] hydrogenase of Chromatium vinosum. The magnetic field dependence of the EPR was used to select specific subsets of molecules contributing to the ENDOR response by stepping through the EPR envelope. Three hyperfine couplings could be clearly followed over the complete field range. Two protons, H1 and H2, display a very similar large isotropic coupling of 12.5 and 12.6 MHz, respectively. Their dipolar coupling is small (2.1 and 1.4 MHz, respectively). A third proton, H3, exhibits a small isotropic coupling of 0.5 MHz and a larger anisotropic contribution of 3.5 MHz. Based on a comparison with structural data obtained from X-ray crystallography of single crystals of hydrogenases from Desulfovibrio gigas and D. vulgaris and the known g-tensor orientation of Ni(r), an assignment of the 1H hyperfine couplings could be achieved. H1 and H2 were assigned to the beta-CH2 protons of the bridging cysteine Cys533 and H3 could belong to a beta-CH2 proton of Cys68 or to a protonated cysteine (-SH) of Cys68 or Cys530.

Catalytic Domain↗
PubMed1999

Medical consequences of terrorism. The conventional weapon threat.

As long as gunpowder and explosives are used to solve disagreements between nations, ethnic groups, and individuals, victims of blast injury continue to arrive occasionally at trauma centers around the world. Bombs planted in crowded urban locations or suicide bombings continue to stress civilian EMS and urban medical systems. Although the clinical presentation depends on whether the blast occurs in open or confined quarters, open air, or water, the pattern of injury inflicted on the body is relatively consistent. The proximity to the detonating device is probably much more important than the size of the bomb. If not injured by secondary, tertiary, or other miscellaneous mechanisms of most conventional bombs with 1 to 20 kg of TNT, people at distances exceeding 6 m will probably not experience substantial blast-induced injury. Three systems are prone to injury. The first is the auditory system, with damage to the eardrum in milder cases and inner-ear injury in more severe cases. The alimentary tract with contusions, hematoma, and occasional perforation of a hollow viscus is the second system involved. Solid organs are rarely damaged in survivors of blast injury. Close proximity to the blast can impose traumatic amputation of limbs (i.e., arms and legs) and ear lobes. Most of these victims succumb to their injuries in the immediate post-injury phase, but the hallmark of blast injury is the involvement of the respiratory system. With expeditious evacuation performed by efficiently coordinated and highly skilled EMS personnel, more patients with blast injuries arrive with signs of life to the medical facility. At the medical facility, the staff need to triage many victims into urgent and nonurgent groups. Only lifesaving procedures should be performed during the initial phase. Later, medical care is directed at patients moved to ICUs. Prompt evacuation after necessary lifesaving procedures in the field; proper triage and distribution; prudent hospital triage and surgical care; and, last but not least, expert critical care provide the best possible outcome in such circumstances.

Amputation, Traumatic↗
PubMed1999

Symptomatic spleno-mesenteric-portal venous thrombosis: recanalization and reconstruction with endovascular stents.

PURPOSE: To evaluate the safety and efficacy of portal reconstruction in patients with symptomatic spleno-mesenteric-portal venous thrombosis. MATERIALS AND METHODS: Portal reconstruction was attempted in 21 patients (seven women, 14 men; mean age, 53.6 years +/- 15.2) with chronic thrombosis of the portal vein alone (n = 8), splenic vein alone (n = 3), or portal, mesenteric, and splenic veins (n = 10). Indications for the procedure were bleeding varices (n = 15), ascites (n = 2), hypersplenism (n = 2), and enteropathy (n = 2). Sixteen procedures were started transhepatically and of these seven were converted to a transjugular intrahepatic portosystemic shunt (TIPS) after successful recanalization of the thrombosed vein. In six patients reconstructions were performed using an intrahepatic portal vein as outflow. Five procedures were performed primarily as TIPS. Wallstents dilated to 7-10 mm were used for reconstruction. The mean follow-up period was 15.2 months +/- 15.9. RESULTS: Technical success of portal reconstruction was 85.7% (18 of 21). Thirty-day mortality was 14.3% (three of 21) but was not procedural related. The cumulative rates of survival, primary patency, and palliation at 43 months of follow-up were 61.2% +/- 13.5%, 63.5% +/- 15.3%, and 31.7% +/- 15.7%, respectively. Secondary patency was 79.1% +/- 13.8%. The only predictor of mortality was the presence of liver disease (P = .001, Cox regression). CONCLUSION: Portal reconstruction is a safe and effective treatment option for patients with symptomatic chronic portal thrombosis. Liver disease predisposes to a higher mortality.

Aged↗
PubMed1999

Lifetime co-morbidities between social phobia and mood disorders in the US National Comorbidity Survey.

BACKGROUND: General population data were used to study co-morbidities between lifetime social phobia and mood disorders. METHODS: Data come from the US National Comorbidity Survey (NCS). RESULTS: Strong associations exist between lifetime social phobia and major depressive disorder (odds ratio 2.9), dysthymia (2.7) and bipolar disorder (5.9). Odds ratios increase in magnitude with number of social fears. Reported age of onset is earlier for social phobia than mood disorders in the vast majority of co-morbid cases. Temporally-primary social phobia predicts subsequent onset of mood disorders, with population attributable risk proportions of 10-15%. Social phobia is also associated with severity and persistence of co-morbid mood disorders. CONCLUSIONS: Social phobia is a commonly occurring, chronic and seriously impairing disorder that is seldom treated unless it occurs in conjunction with another co-morbid condition. The adverse consequences of social phobia include increased risk of onset, severity and course of subsequent mood disorders. Early outreach and treatment of primary social phobia might not only reduce the prevalence of this disorder itself, but also the subsequent onset of mood disorders.

Adolescent↗
PubMed1999

Cyclosporine-induced autologous graft-versus-host disease in patients with acute myeloid leukemia undergoing non-myeloablative chemotherapy without progenitor cell reinfusion.

To determine the incidence and severity of cyclosporine-induced graft-versus-host disease following non-myeloablative chemotherapy without progenitor cell reinfusion in patients with acute leukemia, 17 adults with refractory acute myeloid leukemia (14) or blastic phase of chronic myeloid leukemia (3) were treated with etoposide 2400 mg/m2 and cyclophosphamide 120 mg/kg followed by cyclosporine (CsA) 2.5 mg/kg i.v. daily and interferon gamma 0.025 mg/m2 subcutaneously every other day until day 28. Skin biopsies were obtained on days 14 and 28, or on the appearance of a skin rash, and graded for GVHD. Blood samples were examined at baseline and weekly starting on day 14 for natural killer (NK) cell and T cell lymphocytic changes. Post-treatment lymphocytes from select patients were assessed for allogeneic NK cell and autologous leukemic cell cytolytic activity. Four patients developed pathologic grade 2 cutaneous acute GVHD. Of the three patients who achieved a complete remission, two had evidence of GVHD. Post-treatment, three patients (two with GVHD) in whom adequate numbers of lymphocytes could be obtained showed NK cell cytolytic activity against allogeneic tumor cells (K562), but none had cytolytic activity against their own cryopreserved leukemic cells. These data suggest that in patients with AML treated with subablative doses of chemotherapy without autotransplant, autologous GVHD can be induced, although at an incidence lower than that reported for CsA-induced GVHD following marrow transplantation. An enhancement of T cell and NK cell activity levels similar to experiences in syngeneic models of autologous GVHD was seen, but no direct autologous leukemic cell cytotoxicity could be demonstrated.

Adult↗
PubMed1999

Mutagenesis of the Neisseria gonorrhoeae porin reduces invasion in epithelial cells and enhances phagocyte responsiveness.

Porin (PorB), the major outer membrane protein of Neisseria gonorrhoeae, has been implicated in pathogenesis previously. However, the fact that porin deletion mutants are not viable has complicated investigations. Here, we describe a method of manipulating the porin gene site-specifically. N. gonorrhoeae MS11, which harbours the porB1B (P.1B) porin allele, was used to generate mutants carrying deletions in the surface loops 1 and 5. An 11-amino-acid deletion in loop 1 impaired Opa50-dependent invasion into human Chang epithelial cells, whereas loop 5 deletion exhibited no apparent phenotype. In a second approach, the complete gonococcal porB1B was replaced by the porBNia gene of Neisseria lactamica. Such mutants were unable to induce efficient uptake by epithelial cells but induced an enhanced respiratory response in HL60 phagocytic cells. The increased respiratory burst was accompanied by an enhanced phagocytic uptake of the mutant compared with the wild-type strain. Our data extend previous evidence for multiple central functions of PorB in the infection process.

Alleles↗
PubMed1999

[Long-term results of homograft reconstruction of the trachea in childhood].

BACKGROUND: The treatment of long-segment tracheal stenosis in children is a biological and operative problem. The introduction of preserved allografts established new possibilities for functional tracheal reconstruction. The development of tracheal dimensions in the course of growing is often discussed. PATIENTS AND METHODS: Since 1983 preserved allografts were used in 20 children with acquired tracheal stenosis. The children ranged in age from 1 to 13 years (average: 7.2 years) when the operation was performed. The children were examined postoperatively at adequate intervals. Radiologic measurements of the tracheal dimensions were performed in some of the patients. RESULTS: Today the treatment of all of these children is complete. Some of them are now adults. None of the children demonstrated breathing problems at the time of the end of treatment or after a variable following-up period ranging from 18 months to 14 years. There was no endoscopic or radiographic evidence of constriction in the growing tracheas. Radiographic measurement of the reconstructed tracheas showed an age-adequate growth in length and a small growth in diameter. CONCLUSION: Functional tracheal reconstruction for long-segment tracheal stenosis can be achieved by implantation of preserved allografts even in the early childhood.

Adolescent↗
PubMed1999

[Tracheal reconstruction with preserved tracheal homograft--new aspects].

BACKGROUND: The treatment of long-segment tracheal stenosis is a biological and surgical problem. The introduction of preserved allografts established new possibilities for functional tracheal reconstruction. PATIENTS AND METHODS: Since 1979 preserved allografts were used in 112 patients (including 20 children) with tracheal stenosis. Increasing knowledge in preservation, surgical treatment and pathohistology were put into practice. RESULTS: Implantation of the preserved allografts into the infrahyoid muscles proved to be advantageous. Preservation with the tutoplast method prevented the risk of viral infection, and led to faster and trouble-free post-operative healing. Pathohistological studies let to improve surgical techniques by increasing the knowledge of the nature of tracheal stenosis. CONCLUSION: Functional tracheal reconstruction for long-segment tracheal stenosis can be achieved by implantation of preserved allografts.

Adult↗
PubMed1999

Prehospital blood transfusion in prolonged evacuation.

BACKGROUND: Prehospital blood transfusion for hemorrhaging trauma patients has been used infrequently and is controversial. Currently, there is no satisfactory nonsanguineous fluid therapy for use during prolonged transport, such as in military or rural trauma. METHODS: We retrospectively reviewed prehospital data and hospital charts of all trauma patients in Israel who had received prehospital blood transfusion during a period of 30 months. RESULTS: Forty patients received 60 U of Rh-positive type O packed red blood cells. Mean time from injury to hospital admission was 120 minutes. Twenty-one of 31 patients admitted to the hospital alive (68%) received additional blood transfusions during the initial resuscitation phase, justifying the prehospital transfusion. Of nine documented admissions with hemoglobin of less than 7 g/dL, one patient died of exsanguination. There was one case of a minor adverse reaction that could be attributed to prehospital transfusion. CONCLUSION: Prehospital blood transfusion is justified in certain trauma patients, especially when long prehospital transport is required. Blood may be safely maintained and used by physicians with little experience in care of major trauma.

Adolescent↗
PubMed1999

Surgical resource utilization in urban terrorist bombing: a computer simulation.

BACKGROUND: The objective of this study was to analyze the utilization of surgical staff and facilities during an urban terrorist bombing incident. METHODS: A discrete-event computer model of the emergency room and related hospital facilities was constructed and implemented, based on cumulated data from 12 urban terrorist bombing incidents in Israel. RESULTS: The simulation predicts that the admitting capacity of the hospital depends primarily on the number of available surgeons and defines an optimal staff profile for surgeons, residents, and trauma nurses. The major bottlenecks in the flow of critical casualties are the shock rooms and the computed tomographic scanner but not the operating rooms. The simulation also defines the number of reinforcement staff needed to treat noncritical casualties and shows that radiology is the major obstacle to the flow of these patients. CONCLUSION: Computer simulation is an important new tool for the optimization of surgical service elements for a multiple-casualty situation.

Computer Simulation↗
PubMed1999

Advanced trauma life support (ATLS) courses: should training be refocused towards rural physicians?

Recently there has been an increase in the number of courses designed to improve the theoretical knowledge and practical skills of health workers for immediate emergency management under life-threatening conditions. However, the numbers of applicants for these courses far exceed the available places. Priorities should be reviewed to solve the current shortfall. The purpose of this study was to compare the improvement in basic knowledge associated with the advanced trauma life support (ATLS) programme for paediatricians practising in a metropolitan area, with those practising in rural hospitals. This should facilitate proper use of the limited existing resources for training of physicians. A retrospective, comparative analysis of the impact of the ATLS courses for pediatricians was assessed by analysing scores of multiple choice tests before and after the programme. The study group comprised all Israeli paediatricians (n = 72) who completed the course during 1996. Performance was compared between paediatricians working in major, level I (n = 39) and rural, level II trauma centres (n = 33). After the course, all paediatricians improved their scores; those in level I trauma centres improved their mean precourse scores from 72 +/- 13.6 to 85 +/- 5.4, while those working in level II trauma centres improved from 67 +/- 12.4 to 85 +/- 5.0. The impact of the course was reflected in the net and proportional gains. Both were higher for paediatricians working in level II trauma centres, compared with those working in metropolitan trauma centres. Furthermore, the net gain was significantly higher (p < 0.05). Efforts should be made to increase the participation of paediatricians practising in rural level II trauma centres in trauma care courses. Further research should address the applicability of these results for recruiting primary care physicians to the ATLS courses.

Education, Medical, Continuing↗