Visualization of the F9 antigen on sperm from normal and T/t-complex mutants by immunoscanning electron microscopy

The antigens defined by conventional syngeneic antiserum against F9 embryonal carcinoma cells were localized on mature sperm using immunolabeling and scanning electron microscopy. Labeling patterns were compared for normal (+ / +) mice and mice bearing recessive t-haplotypes. The results showed that antigens detected by intact anti-F9 antiserum are expressed similarly in all genotypes, except for sperm from mice bearing the t¹²-haplotype where the frequency of labeled cells was reduced. Labeling with the IgM fraction of anti-F9 antiserum was lower on sperm from all t-genotypes examined, with sperm from + /t¹² males showing the most marked reduction. In all cases, the labeling patterns were similar, and included a labeling of the whole sperm head with complete anti-F9 antiserum and a restriction of the label to the postacrosomal region when the IgM fraction was used.     

Modification of d-amphetamine- or chlorpromazine-induced hypothermia by β-endorphin,MIF-I,and α-MSH: Mediation by the dopaminergic system

The effects of β-endorphin, MIF-I, and α-MSH on d-amphetamine- and CPZ-induced hypothermias in rats kept at 4°C were tested in three experimental groups: (a) intact; (b) rats with lesions of the olfactory tubercle; and (c) rats in which the link between the DA mesolimbic pathway and the striatum was disconnected. All drugs tested alone (except MIF-I) caused significant hypothermia. Pretreatment with CPZ, MIF-I, and α-MSH potentiated d-amphetamine-induced hypothermia in intact rats. Pretreatment with α-MSH potentiated CPZ-induced hypothermia. β-Endorphin partially blocked d-amphetamine-induced hypothermia, but did not interact with CPZ, MIF-I, or α-MSH. All potentiations were either reduced or disappeared in the incisioned rats. CPZ and α-MSH caused hypothermia in olfactory tubercle-lesioned rats. The results indicate that: (a) the DA mesolimbic pathway is involved in the hypothermic response of all drugs tested; (b) an intact feedback loop is required for the potentiation of the hypothermic response of CPZ on d-amphetamine, MIF-I on d-amphetamine, and α-MSH on d-amphetamine and CPZ; (c) β-endorphin acts as a partial blocker of d-amphetamine; MIF-I is a weak potentiator of d-amphetamine. α-MSH acts as a negative modulator of the DA system, most probably in the striatum.     

Airway reactivity and lung function in triiodothyronine-induced thyrotoxicosis

To evaluate the possible relationship between asthma and hyperthyroidism, airway reactivity and lung function were prospectively compared in healthy volunteers before, during, and after liothyronine (triiodothyronine, T3)-induced hyperthyroidism. Base-line evaluation of the 10 subjects included clinical evaluation, thyroid and pulmonary function tests, and airway reactivity assessed by methacholine inhalational challenge (MIC). All studies were normal. During T3-induced hyperthyroidism, no subject developed respiratory symptoms or changes in pulmonary function or airway reactivity. The mean percent change in forced expiratory volume at 1 s from base line (delta FEV1) of -2.4 +/- 3.0 after MIC was not significantly different from that obtained before T3 administration (-1.4 +/- 1.5, P greater than 0.2). When all serum T3 concentrations and delta FEV1 values before, during and after T3-induced hyperthyroidism were compared, there was no significant correlation. We conclude that T3-induced hyperthyroidism of 3-wk duration has no effect on airway reactivity or lung function in normal volunteers.     

Causes of iron deficiency anemia in an adult inpatient population. Effect of diagnostic workup on etiologic distribution

The causes of iron deficiency anemia in a population of adults admitted to two Jerusalem hospitals within a period of 7 years were examined. About one half of the 262 patients with iron deficiency anemia were over 70 years old. The ratio of males to females exclusive of young females with menorrhagia was 1:1.8. Despite the combined use of various diagnostic procedures, no definite cause of iron deficiency anemia could be established in 34% of patients. Benign gastrointestinal lesions were found in about one half of the cases in both hospitals. The prevalence of GI neoplasms in hospital B with a more intensive use of endoscopic procedures was significantly higher than in hospital A (18% vs 5%, p less than 0.001). The relative usefulness of barium contrast vs endoscopic studies is illustrated by the fact that 22 diagnoses established by endoscopy were missed by barium studies, whereas only 2 of those established by barium studies were not visualized by endoscopy. A particularly high risk group were anemic males aged 50 to 69 years in whom the prevalence of GI neoplasms was 30%. These data indicate that reliance on traditional contrast radioscopy may result in misdiagnosis of a high proportion of gastrointestinal neoplasms.     

Satiation differentially affects performance in a learning assay by nurse and forager honey bees

When not satiated prior to training, there were no differences between foragers and nurse honey bees in the acquisition of an appetitively based conditioned response in an olfactory associative learning assay, but when satiated foragers showed faster acquisition than did nurses. Satiation-related differences between foragers and nurses were more a function of behavioral state than age, because satiated precocious foragers also showed faster acquisition rates than did satiated nurse bees, despite their similar ages. Tests of sucrose responsiveness and retention of conditioned responses indicate that the observed performance differences between nurses and foragers were more likely due to differential sensitivity of sensory and motor processes related to satiation rather than differences in cognitive ability.     

Retinoic acid signaling reduction recapitulates the effects of alcohol on embryo size

Intrauterine growth restriction (IUGR) is commonly observed in human pregnancies and can result in severe clinical outcomes. IUGR is observed in Fetal Alcohol Syndrome (FAS) fetuses as a result of alcohol (ethanol) exposure during pregnancy. To further understand FAS, the severe form of Fetal Alcohol Spectrum Disorder, we performed an extensive quantitative analysis of the effects of ethanol on embryo size utilizing our Xenopus model. Ethanol‐treated embryos exhibited size reduction along the anterior–posterior axis. This effect was evident primarily from the hindbrain caudally, while rostral regions appeared refractive to ethanol‐induced size changes, also known as asymmetric IUGR. Interestingly, some embryo batches in addition to shortening from the hindbrain caudally also exhibited an alcohol‐dependent reduction of the anterior head domain, known as symmetric IUGR. To study the connection between ethanol exposure and reduced retinoic acid levels we treated embryos with the retinaldehyde dehydrogenase inhibitors, DEAB and citral. Inhibition of retinoic acid biosynthesis recapitulated the growth defects induced by ethanol affecting mainly axial elongation from the hindbrain caudally. To study the competition between ethanol clearance and retinoic acid biosynthesis we demonstrated that, co‐exposure to alcohol reduces the teratogenic effects of treatment with retinol (vitamin A), the retinoic acid precursor. These results further support the role of retinoic acid in the regulation of axial elongation.     

Experiments on direct and secondary poisoning by fluoroacetamide (1081) in wildlife and domestic carnivores.

Fluoroacetamide (1081 or F.A.A) is used in Israel for field rodent control. Experiments on direct and secondary, short and long term poisoning caused by 1081 were carried out. Mongoose (Herpestes ichneumon), hyena (Hyaena hyaena), cats and dogs were susceptible. Barn owls (Tyto alba), buzzards (Buteo buteo) and black kites (Milvus m. migrans) were markedly resistant. Barn owls tolerated total direct poisoning ranging from 6.8 to 10.9, and a final dose ranging from 0.8 to 2.0 mg/kg. In secondary poisoning, total doses ranging from 1.7 to 7.1, and final doses ranging from 0.2 to 1.3 mg/kg were tolerated. Buzzards tolerated total direct poisoning ranging from 6 to 12.0, and final doses ranging from 0.7 to 1.3 mg/kg. In secondary poisoning, doses ranging from 0.8 to 10.3 and final doses ranging from 0.2 to 2.4 mg/kg were tolerated. One black kite tolerated a total direct dose of 6.1 and final dose of 0.7 mg/kg, another survived a total dose of 2.3 and final dose of 0.2 mg/kg in secondary poisoning. A small-scale secondary poisoning experiment on two Palestine vipers (Vipera palestinae), a Syrian black snake (Coluber jugularis) and two Montpellier snakes (Malpolon monspessulanus) indicated that these species were resistant to total doses ranging from 0.1 to 3.2 and final doses of 0.1 to 0.8 mg/kg.     

The facilitative effects of alpha-MSH and melanin on learning, thermoregulation, and pain in neonatal MSG-treated rats.

Administration of monosodium glutamate (MSG) in the neonatal period renders the rat to be alpha-MSH deficient later in life. In this study rats received MSG in their neonatal period and were examined at the age of 60 days. alpha-MSH caused hypothermia, potentiated induced hypothermia, blocked paradoxical behavioral thermoregulation, improved performance in the Morris water tank, but had no effect on pain threshold. Melanin only caused an increase in pain threshold. It is suggested that the differential effect of alpha-MSH and melanin is governed by the dopaminergic system.