Israel Medical Association Journal

Background: There is an increasing number of reports of pertussis among older children and adults. The development and licensure of an acellular pertussis vaccine offer the possibility of adult vaccination against the disease. Information on immunity to pertussis in this age group is needed before any vaccination policy can be considered.

Objectives: To study the seroepidemiology of pertussis antibodies in a random sample of adolescents.

Methods: Serum IgG antibodies to whole-cell lysate of Bordetella pertussis were measured by enzyme-linked immunosorbent assay in sera of 533 Israeli military recruits aged 17–18 years. Epidemiologic variables were collected by a questionnaire and analyzed for correlation with pertussis antibodies.  

Results: Of the sera tested 58.6% were positive for pertussis IgG antibodies, while 35.4% were negative and 6% were borderline. The seropositivity rate was significantly higher among females and non-smokers than among males and smokers. Serum samples of subjects found negative to Bordetella pertussis on recruitment were tested again, using the same ELISA assay, 2–3 years later.  Seroconversion during the 3 year military service was detected in 12.5% of 40 subjects. Using the pertussis toxin as the antigen in a subsample of 160 sera, the seroprevalence was lower than that detected by the whole-cell lysate on the same sera (45% vs. 58%).

Conclusions: A significant part of the adolescent population in Israel has low titer of serum IgG antibodies to the multiple antigens of B. pertussis. The relatively low concentration of anti-pertussis antibodies, together with the serological evidence of exposure to the disease indicates that booster immunization with the acellular pertussis vaccine of military recruits should be considered after more information on the incidence of clinical cases of pertussis will be available.

__________________________________

ELISA = enzyme-linked immunosorbent assay

Background: Previous work has suggested an association between increasing size of pterygium and increasing degrees of induced corneal astigmatism.

Objectives: To assess the quantitative relation between pterygium size and induced corneal astigmatism using a computerized corneal analysis system (TMS II) and slit-lamp beam evaluation of pterygium size, and to conclude whether corneal astigmatism is an early indication for surgical intervention.

Methods: We evaluated 94 eyes of 94 patients with unilateral primary pterygium of different sizes, using TMS II and slit-lamp beam measurements of the size of the pterygium (in millimeters) from the limbus to assess parameters of pterygium size with induced corneal astigmatism. Best corrected visual Snellen acuity was performed.

Results: Primary pterygium induced with-the-rule astigmatism. Pterygium extending 16% of the corneal radius or 1.1 mm or less from the limbus produced increasing degrees of induced astigmatism of more than 1.0 diopter. Significant astigmatism was found in 16.16% of 24 eyes with pterygium of 0.2 up to 1.0 mm in size, in 45.45% of 22 eyes with pterygium of 1.1 up to 3.0 mm in size (P≤0.0004), and in 100% of 3 eyes with pterygium of 5.1 up to 6.7 mm in size (P=0.0005). We found that visual acuity was decreased when topographic astigmatism was increased.

Conclusions: When primary pterygium reaches more than 1.0 mm in size from the limbus it induces with-the-rule significant astigmatism (≥1.0 diopter). This significant astigmatism tends to increase with the increasing size of the lesion. Topographic astigmatism tends to be improved by successful removal of the pterygium. These findings suggest that early surgical intervention in the pterygium may be indicated when the lesion is more than 1.0 mm in size from the limbus.

Background: Previous studies have documented an increased incidence of cardiac mortality and sudden death during winter months.

Objectives: To evaluate seasonal variation in sudden death in a hot climate such as the desert region of southern Israel.

Methods: We analyzed the files of 243 consecutive patients treated for out-of-hospital sudden death by the Beer Sheva Mobile Intensive Care Unit during 1989-90. Daily, monthly and seasonal incidence of sudden death was correlated with meteorological data, including temperature, heat stress, relative humidity and barometric pressure.

Results: The seasonal distribution of sudden death was 23% in spring, 21% in summer, 25% in autumn and 31% in winter (not significant). In patients with known heart disease there were more episodes of sudden death in cold weather (<15.4°C) than hot (>34.2°C) (16 vs. 3, P<0.05). Resuscitation was less successful in cold compared with hot weather (28 vs. 11, P<0.05). Of patients older than 65 years, 11 sustained sudden death when heat stress was below 12.4°C compared to 2 patients when heat stress was above 27.5°C (P=0.05).

Conclusion: Despite the warm desert climate, there were more cases of sudden death in older patients and in those with known heart disease during the winter season and on particularly cold days.
 

Background: The etiology of bone marrow failure, a prominent feature of paroxysmal nocturnal hemoglobulinuria, is presently unknown.

Objectives: To evaluate the possible influence of cellular immune mechanisms in the bone marrow failure of PNH.

Methods: We studied marrow erythroid colony formation in a patient with paroxysmal nocturnal hemoglobinuria without hypoplastic/aplastic marrow complications.

Results: In vitro assays revealed a pronounced inhibition of primitive erythroid (BFU-E) progenitor cell growth by marrow T lymphocytes. Removal of T cells prior to culture resulted in a 4.5-fold enhancement of BFU-E numbers. Reevaluation of in vitro erythropoiesis during steroid administration indicated a persistent, albeit less prominent, T cell inhibitory effect.

Conclusion: Our findings provide the first direct evidence for a cellular immune inhibitory phenomenon accompanying PNH.

_____________________________ 

PNH= paroxysmal nocturnal hemoglobinuria

Background: Acute respiratory distress syndrome is a well-recognized condition resulting in high permeability pulmonary edema associated with a high morbidity.

Objectives: To examine a 10 year experience of predisposing factors, describe the clinical course, and assess predictors of mortality in children with this syndrome.

Methods: The medical records of all admissions to the pediatric intensive care unit over a 10 year period were evaluated to identify children with ARDS¹. Patients were considered to have ARDS if they met all of the following criteria: acute onset of diffuse bilateral pulmonary infiltrates of non-cardiac origin and severe hypoxemia defined by <200 partial pressure of oxygen during ³6 cm H2O positive end-expiratory pressure for a minimum of 24 hours. The medical records were reviewed for demographic, clinical, and physiologic information including PaO2² /forced expiratory O2, alveolar–arterial O2 difference, and ventilation index.

Results: We identified 39 children with the adult respiratory distress syndrome. Mean age was 7.4 years (range 50 days to 16 years) and the male:female ratio was 24:15. Predisposing insults included sepsis, pneumonias, malignancy, major trauma, shock, aspiration, near drowning, burns, and envenomation. The mortality rate was 61.5%. Predictors of death included the PaO2/FIO2, ventilation index and A-aDO2³ on the second day after diagnosis. Non-survivors had significantly lower PaO2/FIO2 (116±12 vs. 175±8.3, P<0.001), and higher A-aDO2 (368±28.9 vs. 228.0±15.5, P<0.001) and ventilation index (43.3±2.9 vs. 53.1±18.0, P<0.001) than survivors.

Conclusions: Local mortality outcome for ARDS is comparable to those in tertiary referral institutions in the United States and Western Europe. The PaO2/FIO2, A-aDO2 and ventilation index are valuable for predicting outcome in ARDS by the second day of conventional therapy. The development of a local risk profile may allow early application of innovative therapies in this population. 

___________________________________ 

¹ARDS = acute respiratory distress syndrome

² PaO2 = partial pressure of oxygen

³A-aDO2 = alveolar–arterial O2 difference

Objectives: To analyze the factors that influence the success of physicians in the ATLS®¹ written tests.

Methods: A retrospective study was conducted of 4,475 physicians participating in the Israeli ATLS® training program between 1990 and 1996. Several variables in the records of these physicians were related to their success or failure in the final written examination of the course.

Results: Age, the region of medical schooling, and the medical specialty were found to significantly influence the successful completion of the ATLS® course.

Conclusions: Physicians younger than 45 years of age or with a surgical specialty are more likely to graduate the ATLS® course. The success rate could be improved if the program’s text and questionnaires were translated into Hebrew. 

¹ATLS® = Advanced Trauma Life Support