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Biomedical subjects

A Laor

Publications and source records attributed to A Laor.

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

The cognitive outcome of full-term small for gestational age infants at late adolescence.

OBJECTIVE: To assess the cognitive and academic performance of adolescents who were born small for gestational age (SGA) at term. METHODS: A 17-year historical prospective study was done by matching neonatal data of 1758 infants to the results of the medical and intelligence assessment performed at age 17 years at the army draft board medical examination in Israel. The results of children born SGA (weight at term birth below the third percentile) were compared to those of children who were born appropriate for gestational age (AGA). RESULTS: After adjustment by a multiple linear regression analysis, the mean (+/- standard error of the mean) intelligence test scores were 103.1 +/- 2.9 versus 105.8 +/- 1.5 (P = 0.3) for the males and 100.3 +/- 2.5 versus 104.7 +/- 1.6 (P < .03) for the females. Males born SGA at term were found to have lower educational achievements (having less than 12 years of schooling or attending a vocational school) compared with the AGA group. The odds ratio for this finding after adjustment by a logistic regression analysis was 2.40 (95% confidence interval 1.07-5.39; P < .03). Intranatal events were not found to have an effect on the measured neurodevelopmental outcome. CONCLUSION: Infants born SGA at term have an increased risk for lower cognitive performance and schooling achievements than those born AGA; this result seems to be unrelated to their intranatal course.

Adolescent↗
PubMed1995

Predicting heart rate response to various metabolic rates, environments, and clothing.

A mathematical model that describes heart rate (HR) responses to different combinations of metabolic levels, climatic conditions, and clothing ensembles was developed. The database that served to construct the model consisted of 48 variations representing a wide range of environmental conditions, clothing ensembles, and metabolic rates. The model, which correlates highly with the observed values (r = 0.88, P < 0.0001), is based on physiological and environmental parameters: HR = 57.1 + 0.6HRi + [0.07M - 19.06 - 0.011(Emax - Ereq)] log t, where HRi is initial HR in beats per minute (at rest before the exposure), t is the time of exposure in minutes, M is the metabolic rate in watts, Ereq is the required sweat evaporation for thermal equilibrium in watts, and Emax is the maximal evaporative capacity of the environment in watts. The model's validity was tested by using two independent databases representing wide ranges of conditions; the correlation between measured and predicted values was found to be highly significant (r = 0.83, P < 0.001 and r = 0.77, P < 0.001, respectively). In summary, the present study suggests a valid predictive model for HR that overcomes some of the difficulties observed in other models.

Adult↗
PubMed1995

Calculation of mean arterial pressure during exercise as a function of heart rate.

Mean arterial blood pressure (MAP) is a common characteristic of the cardiac cycle. Usually it is evaluated by assuming that the left ventricular ejection time (systole) constitutes a constant proportion of the cardiac cycle (i.e. 1/3), regardless of the heart rate (HR). However, elevation of HR during exercise results in a reduction of the duration of the ejection period and even a greater reduction of the ventricular filling period. Therefore, a constant diastole/systole proportion at various heart rates may be misleading. The purpose of this study was therefore to evaluate the accurate proportion of the systolic period from the cardiac cycle at different metabolic rates and calculate MAP accordingly. Twenty healthy subjects (age: 20-50 yr.) exercised at different work intensities on a cycle ergometer to elicit HR in the range of 55-180 bpm. During the ride the mitral and aortic flow velocity wave form were recorded by Doppler echocardiography; the mitral flow from the apical view and the aortic flow from the apical long axis view. Blood pressure was measured using a sphygmomanometer. The fraction of systole (St) from the heart cycle was related to HR and was described in mathematical terms as: St = 0.01exp(4.14-40.74/HR) MAP was then calculated from the diastolic blood pressure (dBP) and the pulse pressure (PP) adjusted for St as follows: MAP = dBP+St.PP; (mmHg) The use of the suggested model reduces errors in the evaluation of various cardiac parameters which are related to arterial pressure, such as peripheral resistance, especially under exercise-heat stress.

Adult↗
PubMed1994

Colchicine treatment of AA amyloidosis of familial Mediterranean fever. An analysis of factors affecting outcome.

OBJECTIVE: To elucidate factors possibly influencing the outcome of colchicine therapy in patients with amyloidosis of familial Mediterranean fever (FMF). METHODS: Retrospective analysis of data abstracted from the charts of all 68 FMF patients with amyloidosis who presented during the study period (1974-1992) with proteinuria (> or = 0.5 gm/24 hours) and creatinine values < or = 2.5 mg/dl, received colchicine, and were followed up for > or = 5 years. RESULTS: At the end of the study period, kidney disease had worsened in 31 patients and remained stable in 22. Proteinuria had regressed in 15 patients. Deterioration was related to initial serum creatinine values > or = 1.5 mg/dl (P < 0.01) and to mean colchicine dosage < or = 1.5 mg/day (P < 0.001). The 3 groups were comparable in terms of initial urinary protein levels, duration of proteinuria, presence of hypertension, occurrence of febrile attacks, sex distribution, and proportion of non-compliant patients. CONCLUSION: The therapeutic dosage of colchicine for amyloidosis of FMF is > 1.5 mg/day. This dosage is effective only in patients with initial serum creatinine levels < 1.5 mg/dl.

Adult↗
PubMed1994

Neurofibromatosis type 1 in Israel: survey of young adults.

Neurofibromatosis type 1 (NF1) (von Recklinghausen's disease) is one of the most common human autosomal dominant disorders. In a survey of 374440 17 year old Jewish recruits for military service, 390 cases of NF1 were discovered, with a prevalence of 1.04/1000 (0.94/1000 for males and 1.19/1000 for females), or two to five times the reported prevalence of this disease. NF1 was more common in youngsters whose parents were of North African and Asian origin (1.81/1000 and 0.95/1000, respectively) and less common in those of European and North American origin (0.64/1000). All these differences were statistically significant and may be partially explained by the more advanced parental age of the NF group (as suggested by the larger number of children in the North African and Asian families) or by founder effect or both. The height and weight of the NF1 subjects was significantly lower than those of the controls. The intelligence score of persons with NF1 was similar to that of the control group when corrected for gender and ethnic origin. No significant increase in epilepsy or mental illnesses was found. This study provides evidence of the high overall prevalence of NF1 among Jews in Israel, with significantly increased prevalence in certain ethnic groups.

Analysis of Variance↗
PubMed1994

Longitudinal study on the prevalence of asthma among Israeli young adults.

We studied the medical records of more than 400,000 males and females who were born in 1963-74 and examined at the age of 17-18 years, as part of the routine health assessment prior to induction into the Israel Defense Forces. As part of the assessment, each one was asked whether he/she had ever suffered from asthma or other respiratory disease. Any positive response was confirmed by a letter from the family physician and previous hospitalization records. All patients with symptoms that could be due to asthma, past or present, were referred to examination by a pulmonologist. The severity of asthma was then categorized to three grades of severity. The data were adjusted for sex and ethnic origin and Cochran-Mantel-Haenszel statistics were used to compute the association with 1 degree of freedom. The average prevalence of active disease was 2.7% for males and 2.22% for females. The prevalence of active disease increased significantly during the last decade (chi 2 = 769.25, P < 0.001). A significant association (P < 0.001) between increased active asthma prevalence and the following parameters was recorded. Asthma prevalence was higher among conscripts of European or North American origin (3.63% for males, 2.71% for females) and higher in Jews than among Druze. Increased prevalence was found among males and females who were examined at Tel-Hashomer, 3.4% and 2.41% respectively, in comparison with other geographic areas. A higher prevalence of active asthma was recorded for conscripts living in a kibbutz, 3.13% and 3.12, males and females respectively, as compared with other types of settlements. Higher prevalence was recorded for conscripts who had graduated from high school, 3.27% for males and 2.3% for females, in comparison with other levels of education. Also significantly associated with increased prevalence of active disease were other socioeconomic factors, such as a small number of children in the family and being the firstborn child. Increased prevalence of active asthma in males and females was associated with high IQ (111+), 3.5% and 2.29%, respectively. There was a higher prevalence of asthma among conscripts who were born in the summer and autumn than those born in the winter or spring. Conscripts who had asthma in the past were heavier, taller and fatter than the control group (with 95% confidence intervals). The pattern among females was much the same but did not reach significance.

Adolescent↗
PubMed1993

Effects of time, sex, ethnic origin, and area of residence on prevalence of asthma in Israeli adolescents.

OBJECTIVES: To study effects of time, sex, ethnic origin, and area of residence on prevalence of asthma in Israeli adolescents. DESIGN: Retrospective survey of asthma from computerised medical draft records of conscripts examined up to the end of 1989. SETTING: Five regional centres in Israel. SUBJECTS: 443 186 conscripts (262 836 males and 180 350 females) aged 17-18 who were born over a nine year period. MAIN OUTCOME MEASURES: Asthma determined by medical history, physical examination, and lung function tests at rest and after exercise. RESULTS: Asthma was more prevalent in males than females (26.5/1000 v 21.4/1000, relative risk 1.25 (95% confidence interval 1.19 to 1.32)). Subjects were split into three groups according to year of birth, and prevalence of asthma increased over time from 18/1000 to 24/1000 to 36/1000 (risk of asthma 0.56 (0.54 to 0.59) for first birth group relative to last birth group and 0.69 (0.66 to 0.72) for second group relative to last group). Risk of asthma was also affected by ethnic origin (highest for Western origin and lowest for north African origin, relative risk 1.63 (1.56 to 1.71)) and area of residence (highest in the central coastal region--risk of 1.24 (1.19 to 1.30) relative to the north coastal region--and lowest in inland areas--risk of 0.67 (0.64 to 0.70) relative to north coastal region). CONCLUSIONS: Prevalence of asthma in Israel is increasing and is higher in males, in people of Western origin, and in those living in the most industrialised coastal region.

Adolescent↗
PubMed1993

Increased risk of cancer in patients with Gaucher disease.

BACKGROUND: An increased incidence of cancer, especially hematopoietic in origin, has long been suspected but never established in patients with Gaucher disease. METHODS: To determine whether patients with Gaucher disease have an increased risk of cancer, the authors conducted a retrospective cohort study, comparing the incidence and type of cancer in 48 patients with Gaucher disease with those of 511 control subjects without the disease. RESULTS: Among patients with Gaucher disease, 10 of 48 (20.8%) had cancer, as compared with 35 of 511 (6.8%) of the control group (P = 0.0027; relative risk, 3.6; 95% confidence interval, 1.7-7.5). As compared with the control group, patients with Gaucher disease had a 14.7-fold risk of having cancer of hematopoietic origin (10.4% [5 of 48] versus 0.78% [4 of 511], respectively; P = 0.00037; 95% confidence interval, 5.2-41.7). The mean age at cancer diagnosis in the group with Gaucher disease was 57 +/- 18 years. CONCLUSIONS: The authors conclude that patients with Gaucher disease have a significantly increased risk of cancer, occurring in late adulthood. Of all the cancers, hematologic cancers are significantly more prevalent.

Adult↗
PubMed1993

Are children born small for gestational age at increased risk of short stature?

OBJECTIVE: To assess the height outcome of newborns born small for gestational age. DESIGN: A historical prospective study. SETTING: A cohort of 1758 newborns born at a single university hospital maternity ward and subsequently examined at the military draft medical board at age 17 years. PARTICIPANTS: Newborns whose weight at birth was below the third percentile were defined as small for gestational age. Their body measurements at age 17 years were compared with those of their peers who were appropriate for gestational age. MEASUREMENTS/MAIN RESULTS: The adjusted mean +/- SEM height for boys born small for gestational age vs peers born appropriate for gestational age was 169.9 +/- 1.5 vs 175.4 +/- 0.8 cm (P < .0001); and for girls, 159.4 +/- 1.3 vs 163.1 +/- 0.8 cm (P < .0005). In addition, the risk for height attainment below the 10th percentile was significantly increased for newborns born small for gestational age. The adjusted odds ratio was 4.13 for boys (95% confidence interval, 1.66 to 10.25; P < .0006) and 3.32 for girls (95% confidence interval, 1.38 to 8.05; P < .0005). CONCLUSION: Infants born small for gestational age may be at increased risk for short stature in late adolescence.

Adolescent↗
PubMed1993

The effects of continuous operation in a chemical protective ensemble on the performance of medical tasks in trauma management.

Treating casualties in a chemically hazardous environment constitutes a unique problem. Physical protection of the medical personnel may impair their performance and potentially affect patients' prognoses. The present study examined the effect of prolonged physical protection on the accomplishment of medical tasks related to trauma management. Sixty one emergency medical technicians, acclimatized to operating in protective gear, underwent four rounds of testing during eight hours of continuously wearing either a chemical protective suit or regular fatigues. The quality of the designated medical tasks, including sterility, was maintained throughout the study. A significant reduction in speed of performance was noted (approximately 30% slowing, p < 0.0001 in multivariate analysis) because of protective clothing. There was no additional decrement in performance following a prolonged stay in the protective gear. We conclude that in a chemically contaminated area, fully protected medical personnel are capable of treating trauma patients reasonably well, and for a relatively long period of time. The importance of pretraining and proper instruction is emphasized.

Acclimatization↗
PubMed1993

Is the association between birthweight and height attainment independent of the confounding effect of ethnic and socioeconomic factors?

The association between birthweight and body height attainment at 17 years of age was investigated by studying a sample of 30,083 subjects born in Jerusalem between 1964 and 1971. Birthweights obtained from the computerized records of the Jerusalem Perinatal Study were matched with demographic and medical examination results available from the military draft boards. Linear regression models for standing height by birthweight were fitted for the data in order to adjust for the possible confounding effect of ethnic origin, socioeconomic status (as determined by parental education level), birth order and maternal age. Separate models were constructed for each sex. A significant (P < 0.0001) linear increase in standing height by birthweight of 3.33 cm/1,000 g was observed for the males (mean +/- SE height 174.5 +/- 0.1 cm) and 2.85 cm/1,000 g for the females (mean +/- SE height 163.5 +/- 0.1 cm). This positive linear association between body height at 17 years of age and birthweight was also demonstrated after stratification according to various categories of social class and ethnic origin. Adult body height was thus found to be strongly related to birthweight in both sexes, regardless of ethnic and socioeconomic influences.

Adolescent↗
PubMed1992

Analysis of premature ventricular counts in long term ECG following myocardial infarction.

Frequent and recurrent ventricular premature beats (VPB's) are considered to be associated with a higher risk of sudden cardiac death, particularly for survivors of myocardial infarction (MI). The distribution of VPB's has a large probability mass at zero, and a very heavy right hand tail. In this research, we fitted a model to VPB for patients for which VPB was present. The model was fitted on the basis of a relatively large data set on MI survivors in Israel. The model was fitted by a method which is based on the generalized linear model. This method, which was introduced by Zeger and Liang, is designed for longitudinal data and uses the quasi-likelihood concept. No specific assumptions are required on the shape of the distribution of the dependent variable. The results indicate that the model fits the data quite well but underestimates the very extreme high values. This research demonstrates the applicability of generalized linear models for longitudinal non-Gaussian data. Such data often arise in medical studies. The study also points out the distributional properties of VPB counts. In particular, it shows their associations with simple clinical and epidemiological variables, and with certain time periods during the day.

Cardiac Complexes, Premature↗
PubMed1992

Colchicine prevents kidney transplant amyloidosis in familial Mediterranean fever.

Twenty-one familial Mediterranean fever (FMF) patients who received a kidney transplant for terminal renal failure due to amyloidosis were studied retrospectively to evaluate the prophylactic effect of colchicine on graft amyloidosis. Proteinuria, highly suggestive of kidney transplant amyloidosis, developed in 11 patients within a median of 3 years after transplantation (range 0.5-10 years). In 10 patients, repeated urinalyses for protein were negative during a median of 5 years after transplantation (range 1-13). Patients who developed proteinuria or transplant amyloidosis received smaller colchicine doses than patients without proteinuria--mean 0.69 (range 0-1) versus 1.53 (range 1-2) milligrams per day (p = 0.0002), suggesting that colchicine prevents or delays development of transplant amyloidosis. This prophylactic effect of colchicine was complete at a dose of 1.5 mg/day or more and absent at a daily dose of 0.5 mg or less. In patients who received 1 mg/day, individual variability in the response to colchicine was observed. We conclude that the development of amyloidosis of the kidney transplant in FMF is inevitable at a colchicine dose lower than 1 mg/day, unpredictable at 1 mg/day and usually preventable with 1.5 mg/day or more.

Adolescent↗
PubMed1992

Prevention of overuse injuries of the foot by improved shoe shock attenuation. A randomized prospective study.

In a randomized prospective study among 390 recruits, the hypothesis that improved shoe shock attenuation could lessen the incidence of overuse injuries was tested. During the 14 weeks of training, 90% of the recruits sustained overuse injuries. Recruits training in a modified basketball shoe had a statistically significant lower incidence of metatarsal stress fractures and foot overuse injuries, compared with standard infantry boots, but their overall incidence of overuse injuries was not reduced. The effect of improved shoe shock attenuation was limited to those overuse injuries resulting from vertical impact loads.

Elasticity↗
PubMed1992

Birth weight and intellectual performance in late adolescence.

The impact of birth weight on cognitive performance in late adolescence was assessed in a study of 20,567 male infants born in Jerusalem between 1964-1970. The 17-year follow-up was performed by matching computerized data base records. Stepwise multiple regression analysis was used to estimate the effect of birth weight on intelligence test scores, adjusting for the influence of ethnic origin, maternal and paternal education, social class (determined by area of residence), maternal age, and birth order. These confounders explained 22% of the variance in intelligence test scores. The adjusted differences in intelligence test scores were significantly lower for groups with birth weight less than 2000 g (-6.5 points), 2000-2499 g (-3.6 points), and 2500-2999 g (-1.6 points) compared with the group weighing 3000-3499 g. Most low birth weight infants achieved intellectual performance within the normal range. However, despite this reassuring finding, low weight at birth in male subjects was found to have a statistically significant independent association with inferior intelligence test achievements in late adolescence.

Adolescent↗
PubMed1992

Cigarette smoking and educational level among young Israelis upon release from military service in 1988--a public health challenge.

The prevalence of cigarette smoking was determined in a representative sample of Israeli men and women mostly aged 20-22, upon release from military service. In this sample, 47.5% of the men and 30% of the women reported themselves to be current smokers, and 46% and 26% respectively to be current regular smokers. Of the current smokers 80% of the men and 74% of the women took up smoking before entering military service. Educational level at recruitment was strongly associated with age at uptake of smoking, the prevalence of smoking and the number of cigarettes currently smoked per day. Ethnic differences in smoking prevalence after controlling for education were relatively small. Men and women with less than or equal to 11 years of schooling reported twice the smoking prevalence of those with greater than or equal to 12 years, 71 vs. 35% current smokers in men and 56% vs. 26% current smokers in women respectively. Heavy smoking of greater than or equal to 20 cigarettes per day was reported by 51% and 30% of less educated men and women, respectively, compared with 17% and 9% respectively of those with greater than or equal to 12 years of schooling. We conclude that intervention programs directed toward the prevention of uptake of smoking in adolescents should receive high public health priority in Israel, with special emphasis on adolescents prior to military service and focusing on the more susceptible segments of the young population.

Adult↗
PubMed1991

Long-term effects of vacuum and forceps deliveries.

The long-term effects of vacuum and forceps deliveries are largely unknown. We determined the long-term outcome of instrumental deliveries in 52,282 infants born in Jerusalem between 1964 and 1972. For each individual, events at birth were related to results of an intelligence test and medical examination done at 17 years of age by the Israeli Defence Forces draft board. 1747 individuals were delivered by vacuum, 937 by forceps, 47,500 by spontaneous delivery, and 2098 by caesarean section. Crude data showed that mean intelligence scores at 17 were significantly higher (p less than 0.0001) in the vacuum and forceps deliveries groups than in the spontaneous-delivery group; however, after adjustment for confounding factors by stepwise multiple regression, these differences were no longer seen. Although the forceps-delivery group had functional impairment of feet, vision, and retina compared with the spontaneous-delivery group, and the vacuum-extraction group had impairment of the legs, differences were small. Our findings suggest that infants delivered by vacuum or forceps are not at risk of physical and cognitive impairment at 17 years of age.

Adolescent↗