Search PubMed⌕ Search

Biomedical subjects

A Peleg

Publications and source records attributed to A Peleg.

At least 19 recordsLinked to original sources
PubMed2005

Far-from-equilibrium Ostwald ripening in electrostatically driven granular powders.

We report an experimental study of cluster size distributions in electrostatically driven granular submonolayers. The cluster size distribution in this far-from-equilibrium process exhibits dynamic scaling behavior characteristic of the (nearly equilibrium) Ostwald ripening, controlled by the attachment and detachment of the "gas" particles. The scaled size distribution, however, is different from the classical Wagner distribution obtained in the limit of a vanishingly small area fraction of the clusters. A much better agreement is found with the theory of Phys. Rev. E 65, 046117 (2002)] which accounts for the cluster merger.

Journal Article↗
PubMed2005

Informal medicine: ethical analysis.

CONTEXT: Doctors have been known to treat or give consultation to patients informally, with none of the usual record keeping or follow up. They may wish to know whether this practice is ethical. OBJECTIVE: To determine whether this practice meets criteria of medical ethics. DESIGN: Informal medicine is analysed according to standard ethical principles: autonomy, beneficence and non-maleficence, distributive and procedural justice, and caring. SETTING: Hospital, medical school, and other settings where patients may turn to physicians for informal help. CONCLUSION: No generalisation can be made to the effect that informal medicine is or is not ethical. Each request for informal consultation must be considered on its own merits. GUIDELINES: Informal medicine may be ethical if no payment is involved, and when the patient is fully aware of the benefits and risks of a lack of record keeping. When an informal consultation does not entail any danger to the patient or others, the physician may agree to the request. If, however, any danger to the patient or others is foreseen, then the physician must insist on professional autonomy, and consider refusing the request and persuading the patient to accept formal consultation. If a reportable infectious disease, or other serious danger to the community, is involved, the physician should refuse informal consultation or treatment, or at least make a proper report even if the consultation was informal. If agreeing to the request will result in an unfair drain on the physician's time or energy, he or she should refuse politely.

Attitude of Health Personnel↗
PubMed2003

Anti-cytomegalovirus (CMV) IgG antibody titer in patients with risk factors to atherosclerosis.

Studies have demonstrated cytomegalovirus (CMV) DNA particles in restenotic lesions in atherosclerotic coronary arteries. We have shown that high (>1:800) anti-CMV IgG antibody titers in the serum are associated with active coronary disease and with post coronary angioplasty restenosis. In this study we assessed the anti-CMV antibody titer in patients with risk factors for atherosclerosis (but without documented clinical manifestations). One hundred and eighly-seven patients (men and women aged 40-80 years) that were admitted to the Department of Internal Medicine were recruited to this prospective study. All had at least one risk factor for atherosclerosis, and none had documented coronary artery disease. Fasting blood samples were drawn on admission. Risk factors included hypertension, diabetes mellitus, active smoking, hyperlipidemia, and a positive family history. Ninety-three age- and sex-matched individuals without atherosclerosis risk factors served as the control group. One Hundred and twentysix patients had high anti-CMV antibody titers (>/=1:800) compared with none in the control group. Although 80 patients (90%) in the control group were seropositive, none had anti-CMV IgG antibody titers higher than 1:400. The statistical difference between the patients and the control group was highly significant ( p<0.0001). An immunological response against CMV (expressed as an anti-CMV IgG antibody titer) could be a marker of a long-standing immunological reaction causing an inflammatory response that eventually would cause advanced clinical atherosclerosis. We suggest that anti-CMV antibody titer should be used as an early predictor of atherosclerosis. Our findings support the infectious theory and an association between CMV infection and atherosclerosis at an early stage, maybe even years before clinical events occur.

Adult↗
PubMed2002

Quantitative evaluation of prostatectomy for benign prostatic hypertrophy under a national health insurance law: a multi-centre study.

Assessing regional variation between various medical centres in diagnostic and surgical processes is an approach aimed at evaluating the quality of care. This study analyses the differences between eight medical centres in Israel, where all citizens are covered by medical insurance, through the National Health Insurance Law (NHIL). The analysis refers to the diagnostic process, type of surgery and immediate post-surgical complications associated with prostatectomy for benign prostatic hypertrophy (BPH), which is the most frequent surgical procedure performed on men aged 50+. The study sample was comprised of 261 consecutive prostatectomy patients operated on in eight Israeli medical centres (MC), located in various parts of the country, between November 1996 and April 1997. Co-operation with participating directors of surgical wards was obtained after confidentiality of information had been assured. Surgeons in selected departments abstracted data routinely recorded in the patient's file and filled-out a standard one-page questionnaire. The following items were included: age, the presence of accompanying chronic diseases, preoperative tests, type of operation, and post-surgical complications. In the various MCs 32.6% of the patients underwent more than five preoperative tests ranging from 8.9% to 88.9% (<0.01). Assessment of kidney and bladder normality ranged from 75% to 100% (P < 0.01). The rate of patients whose prostatic symptoms (I-PSS) were assessed ranged from 0% to 79% (P < 0.01). There were also differences in severity of prostatism between the MCs, with severe symptoms ranging from 54.0% to 89.3% (P < 0.05), for type of operation performed (for 'open' prostatectomies, 35.4% to 68.0%, P < 0.01) and post-operative complications (19.0% to 41.6%, P = 0.07). After controlling for case-mix, type of operation was the most important predictor for post-surgical complications. MCs with low volume of surgeries had a higher rate of postoperative complications. We conclude that diagnostic and type of operation and post-surgical complications differed between various MCs. Participating surgeons were willing to fill out a one-page standard questionnaire from data routinely recorded in patients' files.

Aged↗
PubMed2001

Normal scaling in globally conserved interface-controlled coarsening of fractal clusters.

We find that globally conserved interface-controlled coarsening of diffusion-limited aggregates exhibits dynamic scale invariance (DSI) and normal scaling. This is demonstrated by a numerical solution of the Ginzburg-Landau equation with a global conservation law. The general sharp-interface limit of this equation is introduced and reduced to volume preserving motion by mean curvature. A simple example of globally conserved interface-controlled coarsening system: the sublimation/deposition dynamics of a solid and its vapor in a small closed vessel, is presented in detail. The results of the numerical simulations show that the scaled form of the correlation function has a power-law tail accommodating the fractal initial condition. The coarsening length exhibits normal dynamic scaling. A decrease of the cluster radius with time, predicted by DSI, is observed. The difference between global and local conservation is discussed.

Journal Article↗
PubMed2001

Area-preserving dynamics of a long slender finger by curvature: a test case for globally conserved phase ordering.

A long and slender finger can serve as a simple "test bed" for different phase-ordering models. In this work, the globally conserved, interface-controlled dynamics of a long finger is investigated, analytically and numerically, in two dimensions. An important limit is considered when the finger dynamics is reducible to area-preserving motion by curvature. A free boundary problem for the finger shape is formulated. An asymptotic perturbation theory is developed that uses the finger aspect ratio as a small parameter. The leading-order approximation is a modification of the Mullins finger (a well-known analytic solution) whose width is allowed to slowly vary with time. This time dependence is described, in the leading order, by an exponential law with the characteristic time proportional to the (constant) finger area. The subleading terms of the asymptotic theory are also calculated. Finally, the finger dynamics is investigated numerically, employing the Ginzburg-Landau equation with a global conservation law. The theory is in very good agreement with the numerical solution.

Journal Article↗
PubMed2001

Homocysteine levels in patients with risk factors for atherosclerosis.

BACKGROUND: Abundant epidemiological evidence has demonstrated that the presence of mild to moderate hyperhomocysteinemia is an independent risk factor for atherosclerosis in the coronary, cerebral, and peripheral vasculature, and for vascular disease, including coronary disease. It has been demonstrated that plasma total homocysteine level is a strong predictor of mortality in patients with angiographically confirmed coronary artery disease. HYPOTHESIS: The study was undertaken to determine the extent of homocysteine levels in patients without documented coronary artery disease, but with at least one risk factor for atherosclerosis. METHODS: Fasting blood samples were collected prospectively from 160 consecutive patients (50 women and 110 men, mean age 65+/-7 years) who had at least one risk factor for atherosclerosis, but had no documented coronary artery disease. Homocysteine levels were measured by an immunoassay method. RESULTS: Of the patients studied, 78 (48.75%) with at least one risk factor for atherosclerosis had high homocysteine levels; 62 patients had mild hyperhomocysteinemia (15-30 micromol/l); and 16 patients had moderate hyperhomocysteinemia (30-100 micromol/l). CONCLUSIONS: Our data suggest that hyperhomocysteinemia is highly prevalent in patients with risk factors for atherosclerosis. Homocysteine level (an independent convertible risk factor to atherosclerosis) should be measured routinely in patients with risk factors for atherosclerosis and treated appropriately.

Aged↗
PubMed2001

Factors associated with daily smoking among Israeli adolescents: a prospective cohort study with a 3-year follow-up.

BACKGROUND: A prospective, 3-year cohort study of smoking habits was conducted among 9th grade pupils in Israel. METHODS: A self-administered questionnaire was answered by pupils in the 9th grade and again in the 11th and 12th grades. RESULTS: The baseline questionnaire was answered by 748 9th graders. In the 11th grade 448 (60%) completed the questionnaire for the second time, and in the 12th grade 388 (52%) completed the questionnaire. In all, 312 pupils (42% of the original cohort) completed all three questionnaires. There were no significant sociodemographic differences between these 312 and the original 748. Eight 9th graders (2.6%) were active smokers (at least one cigarette daily for the last month) compared with 64 (20.5%) in the 11th grade (P < 0.0001 vs 9th grade) and 70 (22.4%) in the 12th grade (P = 0.34 vs 11th grade). Most pupils knew the health hazards of smoking. Variables associated with smoking in the 11th grade included religiosity (religion was associated with lower smoking rates, P = 0.07), past experimentation with smoking (P < 0.0001), smoking among family members (P < 0.01), perceived future smoking status (P < 0.001), self-image (P < 0.001), influence of a teacher (P = 0.07) or celebrity (P < 0.05), and effect of peer pressure (P < 0.01). These results were similar for the 12th grade students except for active or previous smoking by gender (a significantly greater proportion of females than males, P = 0.04). CONCLUSIONS: The study design reduces the potential bias of follow-up attrition on assessment of predictors for smoking initiation. Gender, social modeling and peer pressure, past experimentation with smoking, smoking among family members, role models, and self-image were associated with smoking. These factors should be emphasized in intervention programs.

Adolescent↗
PubMed2001

Outcomes of a brief alcohol abuse prevention program for Israeli high school students.

PURPOSE: To implement a brief intervention aimed at reducing abuse of alcohol among adolescents, and to assess its effectiveness. METHODS: One thousand 10th-grade students from seven high schools, chosen by random from the roster of all schools in southern Israel, were assigned to intervention and control groups. The intervention, which was based on Botvin's social skills theory, was conducted over 3 days and included dissemination of information, workshops, lectures by guest experts, and activity areas. It was administered by the staff of the high schools and the Psychological Counseling Service in Israel. A self-administered questionnaire was answered anonymously by students in the 10th grade (pretest) and again in the 11th and 12th grades (posttests). It included questions on sociodemographic data, alcohol-related habits, smoking habits, use of illicit drugs, knowledge, and attitudes. Data were collected between 1994 and 1997 with a 76% follow-up rate at 2 years. RESULTS: At baseline there was no statistical difference in alcohol consumption between the intervention and control groups. At 1- and 2-year follow-up the rates of alcohol consumption did not change in the intervention group (p > .05) but rose significantly in the control group (p < .001). In multiple regression analysis the variables male gender, positive attitudes, cigarette smoking, availability of illegal drugs, and intervention group were significant predictors of alcohol consumption. CONCLUSIONS: The results of this study show the effectiveness of this intervention program, based on reduced alcohol consumption in the intervention group at 1- and 2-year follow-up, compared with the control group. Compared with other programs, the present intervention is brief, intensive, and relatively easy to implement.

Adolescent↗
PubMed2001

Second-hand prostatism: effects of prostatic symptoms on spouses' quality of life, daily routines and family relationships.

OBJECTIVES: The aim of this study was to explore the impact of male prostatic symptoms on their partners' quality of life, daily routines and family relationships. METHODS: A structured telephone interview study was carried out on a random sample of 215 of the wives and partners of men aged 50 years or older drawn from those registered at four family medicine centres in Israel. They were asked about sleep disturbances, number of night-time wakings, and the effect on sexual relations, travel, entertainment, family and social relationships. RESULTS: The vast majority of women (86%) were affected by their partners' prostatism, with multiple consequences for their daily routines, quality of life and relationships. Sleep was the area of greatest concern, with 46% of women regularly waking due to their partners' urination disorder. The women reported other limitations: 37% noted problems with sexual functioning; 17% were unable to take long trips with partners; 10% could not visit places without toilets; while 8% were unable to go to the cinema or theatre. Women felt that their partners' prostatic symptoms were also to be blamed for upsetting family relationships (10%) and relationships with friends (16%). There was near total correspondence between women and their male partners regarding the effects of prostatic symptoms. CONCLUSIONS: Prostatism has an impact on men and women; strategies that consider the whole couple should be developed and utilized when considering treatment options.

Comorbidity↗
PubMed2001

Characteristics of patients at a complementary medicine clinic in Beer Sheva: summary of the first two years of operation.

BACKGROUND: "Complementary medicine" incorporates several methods of treatment, all of which aim to promote the health and quality of life of the patient. Public interest and demand for complementary medicine services have increased in recent years in Israel, as they have throughout the western world. OBJECTIVE: To characterize patients attending the Complementary Medicine Clinic in southern Israel at the completion of its first 2 years of operation. METHODS: Data for 398 patients selected at random from 4,400 patients treated in the clinic were collected retroactively from the patients' charts. RESULTS: Of those who visited the clinic, 68% were women with an average age of 49 years. Patients attending the clinic had higher rates of hypertension (20%), diabetes (6%) and heart disease (7%) than the general population of patients insured at the Clalit Health Services in the southern region. In addition to musculoskeletal problems (47%), the other most common complaint was emotional problems (13%) such as tension and anxiety. Acupuncture and Shiatsu were the most commonly used types of treatment (61%). Homeopathy was used by 7%. Among patients with musculoskeletal problems, there were significantly more men than women (P = 0.02), the mean age was higher (P = 0.07), and more of them were referred by friends or family (P = 0.06) than those with other problems. CONCLUSIONS: Characterizing patients attending a complementary medicine clinic is important for the planning of marketing and resource management, and can assist primary care physicians in decisions regarding the referral of patients to this type of healthcare.

Adult↗
PubMed2001

Lower urinary tract symptoms in primary care--a multicenter community-based study in Israel.

BACKGROUND: Lower urinary tract symptoms are highly prevalent in older men, have been shown to affect men's quality of life, and may be associated with more serious outcomes. OBJECTIVES: To determine the prevalence of LUTS among men aged 50 years or older registered at family practice centers in Israel and to assess the effect of these complaints on different aspects of their life. METHODS: In a random sample cohort of men aged 50 years and older, fluent in Hebrew, drawn from those registered in four family clinics in Israel, patients identified with LUTS were interviewed by phone using a structured questionnaire. RESULTS: The prevalence of LUTS in our study was 21%. Less than a third of these patients had low severity LUTS (28%), 59% were rated moderate, and 13% had severe symptoms. Age had a positive correlation with the severity of LUTS, and increasing severity of symptoms had a negative effect on the daily function and quality of life of patients. CONCLUSIONS: Our community-based study shows that LUTS is a common finding among men above the age of 50 (21%) and has a significant negative effect on their quality of life and daily function. Knowledge of these data should make primary care physicians more aware of this common problem and thus improve the treatment and quality of life of these patients by better identification and prompt treatment.

Age Factors↗
PubMed2000

Dynamics of fractal dimension during phase ordering of a geometrical multifractal

A simple multifractal coarsening model is suggested that can explain the observed dynamical behavior of the fractal dimension in a wide range of coarsening fractal systems. It is assumed that the minority phase (an ensemble of droplets) at t=0 represents a nonuniform recursive fractal set, and that this set is a geometrical multifractal characterized by an f(alpha) curve. It is assumed that the droplets shrink according to their size and preserve their ordering. It is shown that at early times the Hausdorff dimension does not change with time, whereas at late times its dynamics follow the f(alpha) curve. This is illustrated by a special case of a two-scale Cantor dust. The results are then generalized to a wider range of coarsening mechanisms.

Journal Article↗
PubMed2000

Smoking cessation support groups in Israel: a long-term follow-up.

BACKGROUND: Smoking is the most important preventable cause of chronic disease in the western world. Many smokers want to quit, but have difficulty overcoming the addictive effect of nicotine. OBJECTIVES: To assess the quitting rate of smokers who participated in smoking cessation groups and to characterize predictors of success or failure over a 1-3 years follow-up period. METHODS: We studied 89 participants in 7 groups. Questionnaires were completed at baseline and after a follow-up period of 1 to 3 years. Smoking cessation was determined by self-report and a carbon monoxide breath test. RESULTS: Of the 89 participants in the support groups 76 (85%) were located. An intention-to-treat analysis was done for these participants. At follow-up 25 (33%) were non-smokers. There was a 95% agreement rate between self-report of smoking status and CO breath analysis. There were no differences between quitters and non-quitters in education level, gender, age at initiation of smoking, previous quit attempts, extent of participation in group meetings, concern about gaining weight, Fagerstrom index, or the number of close friends or relatives who smoke. Belief in one's ability to quit, satisfaction with group meetings, and spouse support were significantly associated with success (P < 0.01). CONCLUSIONS: The quit rate was 33%. Self-report is a reliable method for assessing smoking status. Smokers' belief in their ability to quit must be reinforced. Spouse participation in some group meetings may be beneficial, as may the involvement of a dietician and an expert on exercise. Follow-up "booster" meetings may also help.

Adult↗
PubMed2000

Interruptions to the physician-patient encounter: an intervention program.

BACKGROUND: Israeli physicians are very familiar with the problem of interruptions during encounters with patients. However, a thorough search of the medical literature revealed only one report of this problem from Israel, and none from other countries. OBJECTIVES: To characterize the phenomenon of interruptions to the patient-physician encounter in a clinic in Dimona and to assess the effect of an intervention program designed to reduce the magnitude of this problem. METHODS: During an 8 day work period in March 1997 all patient-physician encounters were recorded and characterized. An intervention program was then designed and implemented to reduce the number of interruptions. Data were again collected a year after the initial data collection. RESULTS: During the 8 day study period prior to the intervention program there were 528 interruptions to 379 encounters (mean of 1.39 per encounter). The main causes of interruptions were entrance of uninvited patients to the examination room (31%) and telephone calls (27%). Most of the interruptions occurred during the morning hours between 8 and 10 a.m. (45%) and at the beginning of the week (Sunday 30%). After the intervention program there were 402 interruptions to 355 encounters (mean of 1.13 per appointment, P = 0.21). CONCLUSIONS: There was no statistically significant improvement in the number of interruptions following the intervention program. This finding is either the result of a local cultural phenomenon, or it indicates a national primary care health system problem that may require a long-term educational program to resolve it. Further research is needed on the magnitude, causes and consequences of interruptions in family practice and, if warranted, methods will have to devised to cope with this serious problem.

Humans↗
PubMed2000

Immunodetection of living trophoblast.

BACKGROUND: Human chorionic gonadotropin, the pregnancy hormone, is synthesized by trophoblast cells which make up the placenta. OBJECTIVE: To determine whether antibody to hCG can be used to specifically detect living trophoblast in vitro by binding to the external membrane. METHODS: Trophoblast was isolated from fresh placentas of women undergoing termination of pregnancy in the first trimester and incubated with monoclonal antibody to hCG. Anti-mouse immunoglobulin G with a fluorescent marker was then added. RESULTS: Syncytiotrophoblast stained positive on the external surface of the cell, while controls of leukocytes, endometrial cells and hepatocytes were negative. CONCLUSION: The hCG monoclonal antibody may be used to specifically detect hCG on the surface of living trophoblast in vitro.

Abortion, Therapeutic↗