Biomedical subjects
Publications and source records attributed to E Landau.
The prevalence of diabetes mellitus among 445 new immigrant Ethiopian Jews was studied immediately after their arrival to Israel, and found to be 0.4%. This low prevalence could be attributed to their long trek accompanied by severe malnutrition which caused death to the old, weak and sick, leaving a selectively young and healthy population group.
We measured the subcutaneous adipose tissue fatty acid composition in 22 male Ethiopian Jews, aged 17-65, shortly after their immigration to Israel. These subjects showed a concentration of linoleic acid (17.8%), which was relatively low compared with Israeli levels, and a high concentration of palmitic acid (28.5%). The linoleic/saturated (P/S) ratio was 0.52. After 5 months, a repeat measurement indicated increases of the linoleic acid content and of the P/S ratio to 20.1% and 0.62, respectively (P less than 0.05). In another sample from the same immigrant group, levels after 1 year in Israel were 20.9% and 25.1% for linoleic and palmitic acid, respectively, and the P/S ratio was 0.67. These results differed significantly (P less than 0.02) from those obtained in the first sample after immigration. Apart from decreasing plasma triglyceride levels, no pattern of lipid changes was discernible in our limited samples. Changes in subcutaneous fatty acid composition reflect changes in diet over months, suggesting a decreased carbohydrate intake and in increased fat intake. It remains to be seen whether changing fatty acid composition in conjunction with changes in blood lipids or other factors, over a prolonged period of time, will affect the cardiovascular risk in the immigrants.
Blood pressure was measured in 483 Ethiopian immigrants during the first week following their arrival in Israel. Mean levels of diastolic (DBP) and systolic blood pressures (SBP) were very low compared with known levels in the Israeli population. BPs were elevated in men greater than 20 years old and in women greater than 40 years old. Quetelet index averaged below 2.00 g/cm2. Considerable weight gains were observed in 265 individuals examined after 1 year. Simultaneously, DBP increased by 4 mm Hg on average, whereas the changes in SBP were small. At the end of 1 year, the mean SBP ranged from 107 (age 5-9 and 10-14) to 124 mm Hg (age greater than or equal to 60) and mean DBP from 69 (age 10-14 and 15-19) to 78 mm Hg (age greater than or equal to 60), remaining nevertheless considerably lower than levels observed in diverse Israeli population groups. Covariance analysis revealed that initial BPs, gender, age, and weight gain significantly affected SBP and DBP at the end of the year.
The rodent GnRH receptor was characterized in Xenopus oocytes injected with RNA isolated from rat pituitary and from a gonadotrope cell line, alpha T3, derived from a transgenic mouse. Three to 4 days after 150-200 ng RNA injection, 93% of the oocytes, which were recorded by voltage clamp, responded to 10(-7) M GnRH. The mean inward currents obtained after RNA injection were 620 +/- 88 nA (n = 22) with pituitary RNA and 1415 +/- 598 (n = 4) with alpha T3 RNA. The threshold GnRH concentration able to evoke the dose dependent current after pituitary RNA injection was 3 x 10(-9) M GnRH. The GnRH receptor response of the oocyte was antagonized by [D-Phe2,6,Pro3] GnRH and [N-Ac-D-Na](2)1, D-alpha D-Me, pCl-Phe2, D-Arg6, D-Ala10-NH2]GnRH and could be elicited by D-Ser(But)6,Pro9-N-ethylamide GnRH (buserelin). The reversal potential of the GnRH generated current as determined by voltage-ramp was -22.5 +/- 1.0 mV (n = 7) and -25.6 +/- 3.3 mV (n = 3) in pituitary and cell line RNA-injected oocytes respectively, consistent with the chloride reversal potential. The GnRH receptor response was virtually eliminated by intracellular EGTA injection but was unaffected by ligand application in calcium-free perfusate. The GnRH-evoked response is mimicked by intracellular injection of inositol 1,4,5-trisphosphate. To determine the size of the GnRH receptor mRNA, alpha T3 RNA was size fractionated through a sucrose gradient. The maximal GnRH response was induced by a fraction larger than the 28S ribosomal peak. Thus we find that oocytes injected with RNA from an appropriate source develop an electrophysiological response to GnRH which is dependent on intracellular calcium mobilization, is independent of extracellular calcium, and may be mediated by inositol 1,4,5-trisphosphate.
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We conducted a double-blind controlled study of individuals exposed to arsenic trioxide in a copper-smelting factory. Subjects fell into three categories of peripheral neuropathy: none, subclinical, and clinical. The subclinical group had no symptoms or signs of numbness or reduced reflexes, but did have reduced nerve conduction velocity and amplitude measurements. Clinical neuropathy groups had signs and symptoms of neuropathy and electrophysiologic abnormalities. The clinical and subclinical groups correlated with increased content of arsenic in urine, hair and nails. The incidence of subclinical and clinical neuropathy was greater in arsenic workers than in unexposed controls.
Microwave radiation is coming into increasing use in many countries; it is in use in communications, in industry, for ovens in the home and in commercial establishments and for diathermy. The power output is increasing steadily and community exposure is already a fact. East European countries claim that adverse effects can result from exposure substantially lower than levels permitted in Western countries. Also some of the effects claimed are frequent and disabling. Prolonged and cumulative exposure is especially suspect. While studies in animals are necessary, studies in man cannot be dispensed with. Extrapolation from on species of animal to another, and even more, to man, is hazardous. Moreover, epidemiologic studies are needed to uncover the potentially wide variety of subtle effects, especially mental. Fortunately, there are indices of exposure which can be used in field studies and dosimetry is reaching the point where it can be applied to field studies.
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Twenty-five residents (sixty-nine to ninety-three years old) of two Israeli homes for the elderly were investigated in order to see if there was a correlation between the creative attitude (self-actualizing personality) and the way of coping with the process of aging and attitude toward death. The results showed that the more creative-actualizing a personality, the better the coping with aging phenomena and the less denial of death.
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