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Biomedical subjects

Y Yerushalmi

Publications and source records attributed to Y Yerushalmi.

6 recordsLinked to original sources
PubMed2001

The response of a homochrome grasshopper, Oedipoda miniata, to the dark-colour-inducing neurohormone (DCIN) of locusts.

The effect of the dark-colour-inducing neurohormone (DCIN=[His(7)]-corazonin) of locusts was investigated in nymphs of the grasshopper, Oedipoda miniata, which exhibit strong homochromy, but neither green-brown, nor phase colour polymorphism. Graded doses of synthetic DCIN were injected in 1 µl of olive oil into 0-24-h-old penultimate nymphs. DCIN induced dose-dependent darkening in the recipients, seen 4 days after injection (still in the penultimate nymphal instar), as well as in the subsequent last-instar nymphs. The dose-range obtained between discernible and maximum (almost black) darkening extended over three orders of magnitude, from 1 pmol to 1 nmol of DCIN. In spite of the darkening observed already in the penultimate nymphal instar, the exuviae in the moult from this to the last nymphal instar did not show marked dark patches. However, the exuviae of the next moult (from last-instar nymph to adult) showed such dark patches, which increased with the increase of the dose, revealing the presence of exocuticular melanin. We conclude that DCIN, or a very close peptide, is the endogenous hormone which plays the major or sole role in the control of homochromy of O. miniata and possibly also of other acridids which exhibit homochromy.

Journal Article↗
PubMed1999

Identification of the gregarization-associated dark-pigmentotropin in locusts through an albino mutant.

In response to crowding, locusts develop characteristic black patterns that are well discernible in the gregarious phase at outbreaks. We report here a dark-color-inducing neuropeptide (dark-pigmentotropin) from the corpora cardiaca of two plague locusts, Schistocerca gregaria and Locusta migratoria. The chromatographic isolation of this neuropeptide was monitored by using a bioassay with an albino mutant of L. migratoria. The neurohormone, consisting of 11 amino acids, is identical to [His7] corazonin, previously isolated from corpora cardiaca of another acridid without known function. The present results show that even in isolated (solitary) nymphs, [His7] corazonin induces gregarious black patterns. Its primary structure shows some similarity with the vertebrate melanophore stimulating hormone.

Animals↗
PubMed1990

Preferential uptake of a water-soluble phthalocyanine by atherosclerotic plaques in rabbits.

This study is the first demonstration of preferential accumulation of a water soluble phthalocyanine dye in atheromatous plaques in the rabbit. Two groups of rabbits with diet-induced atheromatous plaques were killed 4 and 24 h following intravenous administration of copper phthalocyanine tetrasulfonate. Uptake of the dye by plaque-containing and normal appearing aortae was evaluated macroscopically and quantitatively by extraction of the dye from the tissues. The concentration of the dye in the atheromatous plaques was 2.6 and 1.7 times higher than in the normal vessel wall at 4 and 24 h, respectively. The concentration of the dye in normal appearing aortae in the 2 study groups was similar to that of aortae of control rabbits which were fed a normal diet and exposed to the dye for the same time periods. We conclude that copper phthalocyanine accumulates preferentially in atheromatous plaques in rabbits. These findings provide a basis for the utilization of phthalocyanines for plaque identification and for photodynamic therapy of atherosclerosis.

Animals↗
PubMed1990

Recombinant alpha-interferon may be efficacious in acute hepatitis B.

Whereas, in chronic type B hepatitis, the therapeutic effect of alpha-interferon has been studied extensively, data on the effect of interferon on the course and prognosis of acute hepatitis B are scarce in the literature. We report a case of acute type B hepatitis complicated by life-threatening extrahepatic manifestations where recombinant alpha-interferon facilitated clinical, biochemical, and serological recovery.

Acute Disease↗
PubMed1984

Exercise-induced left ventricular dysfunction in young men with asymptomatic diabetes mellitus (diabetic cardiomyopathy).

Radionuclide ventriculographic studies were performed at rest and during exercise on 30 consecutive men, aged 21 to 35 years with diabetes mellitus without evidence of coronary artery or any other cardiovascular disease, and in 20 normal age-matched subjects. Sixteen (53%) were treated with insulin and 14 (47%) were treated with either diet (6 patients) or oral antidiabetic therapy (8 patients). All patients from both groups had normal left ventricular (LV) ejection fraction (EF) at rest. In 5 of the 30 diabetic patients (17%), LVEF decreased after exercise, in 8 (27%) it remained unchanged and in 17 it increased normally. Mean LVEF at rest and after exercise in this group was 66 +/- 7% and 72 +/- 7% (+/- standard deviation), respectively. In all normal subjects, LVEF increased after exercise. Mean LVEF at rest and after exercise in the normal group was 66 +/- 7% and 76 +/- 9%, respectively. No patient had evidence of regional dysfunction at rest or after exercise. LV function was not related to serum glucose levels during the test, modality of treatment, insulin dependency or duration of the disease. Three of 4 patients with diabetic microvascular complications showed LV dysfunction. In 4 of 5 patients in whom LVEF decreased after exercise, thallium studies showed normal perfusion. Thus, diabetes mellitus may cause exercise-induced global LV dysfunction in young men with no evidence of cardiovascular disease. This phenomenon apparently does not seem to follow the known course of diabetic microvascular complications.

Adolescent↗