The objective of this study was to determine the effects of teaching the scooping-resheathing met... more The objective of this study was to determine the effects of teaching the scooping-resheathing method on the incidence of needle-stick injuries in medical students. Before starting their first clerkship, 81 medical students were given a 15-min lecture on the high incidence and dangers of needle-stick injuries and a demonstration of the scooping-resheathing method. The number of needle-stick injuries that occurred during the 3-month clerkship was compared with the number reported by 86 medical students who had completed their first clerkship 1 year previously and had not been given such instruction. Compared with controls, the study group had a 3.8-fold lower risk of needle-stick injury (95% confidence interval, 2.0-7.4, P < 0.0001) and a 8.3-fold lower risk of multiple needle-stick injuries (95% confidence interval, 2.0-35.0, P < 0.001). Those in the study group, who consistently used the scooping method had a much lower risk of injury than those who did not (1 of 36 [2.8%] vs. 8 of 45 [17.4%], P = 0.039). We conclude that a lecture recommending the scooping-resheathing method is effective in reducing the risk of needle-stick injuries in medical students during their first rotation. Because this is the first time that an intervention not requiring change in equipment has been successful, further studies are warranted to substantiate our findings and for extrapolation to other medical personnel in other cultural settings.
Blood lead (PbB) and red cell zinc protoporphyrin (ZPP) concentrations are widely used biomarkers... more Blood lead (PbB) and red cell zinc protoporphyrin (ZPP) concentrations are widely used biomarkers for lead toxicity. It is uncertain, however, whether either or both are needed for monitoring lead exposure and how discordant PbB and ZPP values should be interpreted. We reviewed the results of PbB and ZPP determinations in 94 workers in a lead-battery plant over a 13-year period and retrieved all 807 sets of tests in which both PbB and ZPP were available, with a follow-up PbB value 6 months later. PbB exceeded 1.93 μmol/L (40 μg/dL) in 414 (51%), and 2.90 μmol/L (60 μg/dL) in 105 (14%) of the blood samples. We derived the test properties of various ZPP concentrations for concurrent “toxic” PbB concentrations, defined as ≥1.93 and 2.90 μmol/L (40 and 60 μg/dL). The results indicated that, given a population of lead-exposed workers with a 10% prevalence of PbB of ≥2.90 μmol/L (60 μg/dL), a policy of testing PbB only in those with ZPP >0.71 μmol/L (40 μg/dL) would obviate 42% of the ...
Periodic complete blood counts are not recommended for disease prevention in low-risk, non-pregna... more Periodic complete blood counts are not recommended for disease prevention in low-risk, non-pregnant adults. Consequently, there are few follow-up studies of the prevalence of incidentally detected anemia in asymptomatic subjects and its significance for their well-being. The objective of this survey is to determine the frequency of anemia and its predictive value for disease over a 15-yr annual follow-up of a cohort of asymptomatic young males, selected for physical fitness and intelligence. One thousand Israeli airmen aged 18-30 yr at entry into this historical-prospective study in 1968 were used as subjects. Hematocrit (Hct) levels were examined annually. On the average each subject had 13.2 tests in the course of the 15 yr follow-up. We arbitrarily defined anemia as a Hct of 40% or less on two or more tests, and compared the prevalence of diagnosed disorders in subjects with and without anemia. During follow-up, anemia was found in 125 (12.5%) of the subjects. On successive annua...
Seasonal changes in calcitropic hormones might be expected, being that dietary calcium intake may... more Seasonal changes in calcitropic hormones might be expected, being that dietary calcium intake may differ with fluctuations in climate and temperature, and vitamin D is diet- and sunlight-dependent. While there are studies on elderly subjects, prospective data on younger men is limited. The objective of this study was to clarify possible seasonal changes in homeostatic regulators of calcium in Israeli men aged 25-64 years. The study was a prospective follow-up analysis of data collected during June-August 1995 and 1996 (summer) and January March 1995 and 1996 (winter). Subjects were ninety-five industrial male employees with and without occupational lead exposure. The main outcome measures were summer and winter serum concentrations of parathyroid hormone (PTH), 25-hydroxyvitamin D (25-OH-D), and 1,25-dihydroxyvitamin D (calcitriol). Summer and winter values of PTH were similar (38.2 and 39.8 ng/l, respectively). 25-OH-D levels were significantly higher in summer (32.8 ng/ml) than in...
OBJECTIVE: To examine possible seasonal differences in circadian blood pressure patterns and the ... more OBJECTIVE: To examine possible seasonal differences in circadian blood pressure patterns and the specific contribution of indoor temperature. METHOD: Twenty-four-hour ambulatory systolic blood pressure (SBP) and diastolic blood pressure (DBP) were monitored once in summer and once in winter in 101 healthy subjects aged 28-63 years. Subjects were interviewed concerning health-related habits, and measurements of environmental and occupational conditions were obtained. RESULTS: After controlling for possible confounders, mean SBP during work was significantly higher in winter than in summer by 3.4 mmHg. Both in winter and in summer, the highest values were recorded during work. The daily SBP circadian amplitude was higher in winter, reflected by higher mean SBP during the day and lower mean SBP at night. All of the daytime DBP measurements were higher in winter than in summer, but at night there were no seasonal differences. The blood pressure showed an independent association with sea...
The efficacy of transdermally administered scopolamine was compared with the efficacy of oral dim... more The efficacy of transdermally administered scopolamine was compared with the efficacy of oral dimenhydrinate and placebo therapy in the prevention of motion sickness at sea. Medication was administered on a controlled double blind basis to 140 subjects. A placebo effect reduced the motion sickness incidence (MSI) from 57.69% in the control group to 43.47%. Administration of dimenhydrinate reduced the MSI to 22.22% and the use of Transdermal Therapeutic System Scopolamine (TTSS) further reduced the MSI to 16.66%. TTSS afforded 61.67% protection against motion sickness at sea, compared to 48.88% protection with dimenhydrinate.
Trauma to the back from the force of chronic stress is thought to be an etiologic factor in isthm... more Trauma to the back from the force of chronic stress is thought to be an etiologic factor in isthmic spondylolisthesis (SLL). The relationship of first degree spondylolisthesis to low back pain (LBP) is controversial. We compare the prevalence of SLL in helicopter pilots who are subject to strong vibrational forces, with other airforce personnel. Helicopter pilots had more than a four times higher prevalence of SLL (4.5%) than did cadets (1.0%) and transport pilots (0.9%). Low back pain was more frequent in pilots with SLL than in those without this lesion but in no case was the pain disabling or the defect progressive. We conclude that SLL may be induced by vibrational forces and although SLL is associated with LBP, the pain was little clinical significance.
Exposure to aircraft (A/C) noise is considered to be one of the factors which causes permanent he... more Exposure to aircraft (A/C) noise is considered to be one of the factors which causes permanent hearing threshold shifts among military aircrew. Consequently most studies, dealing with this field of evaluation, fail to focus on the contribution of other elements, especially biological (physiological) ones. We, therefore, decided to evaluate the effect of the subject's age on this process. Audiometric records of 777 aircrew members within the Israeli Air Force were examined. The average age was 27.2 +/- 5.2 years. The individual files were composed of all yearly audiograms from time of recruitment to present, personal information, recorded flight time and type of A/C flown (i.e., rotary-wing and fighter, transport and light fixed-wing aircraft). Hearing loss was studied using two criteria (a. USAF criteria; b. acoustic trauma criteria we devised). The significance of each of the factors was analysed by using uni- and multivariate analysis (Pearson correlation and stepwise multiple...
Pilots were examined in order to determine whether the cumulative incidence or point prevalence o... more Pilots were examined in order to determine whether the cumulative incidence or point prevalence of asymptomatic microscopic hematuria is associated with air duty. The cumulative incidence of recurrent microscopic hematuria over a 12-15-year period was 11.3%(17/151) in fighter pilots, 10.0%(8/80) in helicopter pilots, and 13.8% (11/80) in transport pilots. Similarly, the point prevalence of microscopic hematuria in those who had flown the day prior to the urinalysis was no higher than found in the control group. We conclude that air duty does not cause microscopic hematuria either chronically or during the day after the stress of air flight.
The abnormal ECG T wave changes associated with mitral valve prolapse (MVP) were studied and quan... more The abnormal ECG T wave changes associated with mitral valve prolapse (MVP) were studied and quantitated in a group of 36 asymptomatic individuals with MVP and compared with a 27-member control group. The mean frontal plane T wave axis shifted markedly leftward on standing, with T wave axis less than or equal to 0 degrees in 16 (44%) of the subjects with MVP vs. only 2 (7.4%) of the control group, while the QRS-T angle widened to more than 60 degrees in 18 (50%) of those with MVP. Marked left axis deviation of the T wave on standing with T wave axis less than or equal to -30 degrees was found only in subjects with MVP, and their QTc interval was longer, P less than 0.05. In 11 subjects with mitral valve bowing or rounding on the echocardiogram (i.e., less than 2 mm posterior mitral valve displacement), intermediate grades of T wave axis shifts were seen.
The objective of this study was to determine the effects of teaching the scooping-resheathing met... more The objective of this study was to determine the effects of teaching the scooping-resheathing method on the incidence of needle-stick injuries in medical students. Before starting their first clerkship, 81 medical students were given a 15-min lecture on the high incidence and dangers of needle-stick injuries and a demonstration of the scooping-resheathing method. The number of needle-stick injuries that occurred during the 3-month clerkship was compared with the number reported by 86 medical students who had completed their first clerkship 1 year previously and had not been given such instruction. Compared with controls, the study group had a 3.8-fold lower risk of needle-stick injury (95% confidence interval, 2.0-7.4, P < 0.0001) and a 8.3-fold lower risk of multiple needle-stick injuries (95% confidence interval, 2.0-35.0, P < 0.001). Those in the study group, who consistently used the scooping method had a much lower risk of injury than those who did not (1 of 36 [2.8%] vs. 8 of 45 [17.4%], P = 0.039). We conclude that a lecture recommending the scooping-resheathing method is effective in reducing the risk of needle-stick injuries in medical students during their first rotation. Because this is the first time that an intervention not requiring change in equipment has been successful, further studies are warranted to substantiate our findings and for extrapolation to other medical personnel in other cultural settings.
Blood lead (PbB) and red cell zinc protoporphyrin (ZPP) concentrations are widely used biomarkers... more Blood lead (PbB) and red cell zinc protoporphyrin (ZPP) concentrations are widely used biomarkers for lead toxicity. It is uncertain, however, whether either or both are needed for monitoring lead exposure and how discordant PbB and ZPP values should be interpreted. We reviewed the results of PbB and ZPP determinations in 94 workers in a lead-battery plant over a 13-year period and retrieved all 807 sets of tests in which both PbB and ZPP were available, with a follow-up PbB value 6 months later. PbB exceeded 1.93 μmol/L (40 μg/dL) in 414 (51%), and 2.90 μmol/L (60 μg/dL) in 105 (14%) of the blood samples. We derived the test properties of various ZPP concentrations for concurrent “toxic” PbB concentrations, defined as ≥1.93 and 2.90 μmol/L (40 and 60 μg/dL). The results indicated that, given a population of lead-exposed workers with a 10% prevalence of PbB of ≥2.90 μmol/L (60 μg/dL), a policy of testing PbB only in those with ZPP >0.71 μmol/L (40 μg/dL) would obviate 42% of the ...
Periodic complete blood counts are not recommended for disease prevention in low-risk, non-pregna... more Periodic complete blood counts are not recommended for disease prevention in low-risk, non-pregnant adults. Consequently, there are few follow-up studies of the prevalence of incidentally detected anemia in asymptomatic subjects and its significance for their well-being. The objective of this survey is to determine the frequency of anemia and its predictive value for disease over a 15-yr annual follow-up of a cohort of asymptomatic young males, selected for physical fitness and intelligence. One thousand Israeli airmen aged 18-30 yr at entry into this historical-prospective study in 1968 were used as subjects. Hematocrit (Hct) levels were examined annually. On the average each subject had 13.2 tests in the course of the 15 yr follow-up. We arbitrarily defined anemia as a Hct of 40% or less on two or more tests, and compared the prevalence of diagnosed disorders in subjects with and without anemia. During follow-up, anemia was found in 125 (12.5%) of the subjects. On successive annua...
Seasonal changes in calcitropic hormones might be expected, being that dietary calcium intake may... more Seasonal changes in calcitropic hormones might be expected, being that dietary calcium intake may differ with fluctuations in climate and temperature, and vitamin D is diet- and sunlight-dependent. While there are studies on elderly subjects, prospective data on younger men is limited. The objective of this study was to clarify possible seasonal changes in homeostatic regulators of calcium in Israeli men aged 25-64 years. The study was a prospective follow-up analysis of data collected during June-August 1995 and 1996 (summer) and January March 1995 and 1996 (winter). Subjects were ninety-five industrial male employees with and without occupational lead exposure. The main outcome measures were summer and winter serum concentrations of parathyroid hormone (PTH), 25-hydroxyvitamin D (25-OH-D), and 1,25-dihydroxyvitamin D (calcitriol). Summer and winter values of PTH were similar (38.2 and 39.8 ng/l, respectively). 25-OH-D levels were significantly higher in summer (32.8 ng/ml) than in...
OBJECTIVE: To examine possible seasonal differences in circadian blood pressure patterns and the ... more OBJECTIVE: To examine possible seasonal differences in circadian blood pressure patterns and the specific contribution of indoor temperature. METHOD: Twenty-four-hour ambulatory systolic blood pressure (SBP) and diastolic blood pressure (DBP) were monitored once in summer and once in winter in 101 healthy subjects aged 28-63 years. Subjects were interviewed concerning health-related habits, and measurements of environmental and occupational conditions were obtained. RESULTS: After controlling for possible confounders, mean SBP during work was significantly higher in winter than in summer by 3.4 mmHg. Both in winter and in summer, the highest values were recorded during work. The daily SBP circadian amplitude was higher in winter, reflected by higher mean SBP during the day and lower mean SBP at night. All of the daytime DBP measurements were higher in winter than in summer, but at night there were no seasonal differences. The blood pressure showed an independent association with sea...
The efficacy of transdermally administered scopolamine was compared with the efficacy of oral dim... more The efficacy of transdermally administered scopolamine was compared with the efficacy of oral dimenhydrinate and placebo therapy in the prevention of motion sickness at sea. Medication was administered on a controlled double blind basis to 140 subjects. A placebo effect reduced the motion sickness incidence (MSI) from 57.69% in the control group to 43.47%. Administration of dimenhydrinate reduced the MSI to 22.22% and the use of Transdermal Therapeutic System Scopolamine (TTSS) further reduced the MSI to 16.66%. TTSS afforded 61.67% protection against motion sickness at sea, compared to 48.88% protection with dimenhydrinate.
Trauma to the back from the force of chronic stress is thought to be an etiologic factor in isthm... more Trauma to the back from the force of chronic stress is thought to be an etiologic factor in isthmic spondylolisthesis (SLL). The relationship of first degree spondylolisthesis to low back pain (LBP) is controversial. We compare the prevalence of SLL in helicopter pilots who are subject to strong vibrational forces, with other airforce personnel. Helicopter pilots had more than a four times higher prevalence of SLL (4.5%) than did cadets (1.0%) and transport pilots (0.9%). Low back pain was more frequent in pilots with SLL than in those without this lesion but in no case was the pain disabling or the defect progressive. We conclude that SLL may be induced by vibrational forces and although SLL is associated with LBP, the pain was little clinical significance.
Exposure to aircraft (A/C) noise is considered to be one of the factors which causes permanent he... more Exposure to aircraft (A/C) noise is considered to be one of the factors which causes permanent hearing threshold shifts among military aircrew. Consequently most studies, dealing with this field of evaluation, fail to focus on the contribution of other elements, especially biological (physiological) ones. We, therefore, decided to evaluate the effect of the subject's age on this process. Audiometric records of 777 aircrew members within the Israeli Air Force were examined. The average age was 27.2 +/- 5.2 years. The individual files were composed of all yearly audiograms from time of recruitment to present, personal information, recorded flight time and type of A/C flown (i.e., rotary-wing and fighter, transport and light fixed-wing aircraft). Hearing loss was studied using two criteria (a. USAF criteria; b. acoustic trauma criteria we devised). The significance of each of the factors was analysed by using uni- and multivariate analysis (Pearson correlation and stepwise multiple...
Pilots were examined in order to determine whether the cumulative incidence or point prevalence o... more Pilots were examined in order to determine whether the cumulative incidence or point prevalence of asymptomatic microscopic hematuria is associated with air duty. The cumulative incidence of recurrent microscopic hematuria over a 12-15-year period was 11.3%(17/151) in fighter pilots, 10.0%(8/80) in helicopter pilots, and 13.8% (11/80) in transport pilots. Similarly, the point prevalence of microscopic hematuria in those who had flown the day prior to the urinalysis was no higher than found in the control group. We conclude that air duty does not cause microscopic hematuria either chronically or during the day after the stress of air flight.
The abnormal ECG T wave changes associated with mitral valve prolapse (MVP) were studied and quan... more The abnormal ECG T wave changes associated with mitral valve prolapse (MVP) were studied and quantitated in a group of 36 asymptomatic individuals with MVP and compared with a 27-member control group. The mean frontal plane T wave axis shifted markedly leftward on standing, with T wave axis less than or equal to 0 degrees in 16 (44%) of the subjects with MVP vs. only 2 (7.4%) of the control group, while the QRS-T angle widened to more than 60 degrees in 18 (50%) of those with MVP. Marked left axis deviation of the T wave on standing with T wave axis less than or equal to -30 degrees was found only in subjects with MVP, and their QTc interval was longer, P less than 0.05. In 11 subjects with mitral valve bowing or rounding on the echocardiogram (i.e., less than 2 mm posterior mitral valve displacement), intermediate grades of T wave axis shifts were seen.
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Papers by Joseph Ribak