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Biomedical subjects

E Cohen

Publications and source records attributed to E Cohen.

At least 289 records · Page 16Linked to original sources
PubMed1985

Effects of chronically elevated intake of sweet solutions on sexual behavior of male rats.

Three experiments were conducted on the sexual behavior of gonadally intact and castrated male Sabra rats. Half of the animals drank water during the course of the experiment and half were offered sweet solutions, the assumption being that sweet gustatory stimulation elevates the level of central endogenous opioid peptides in rats. The effects on sexual behavior of the following drugs were explored: the opiate receptor blocker naloxone (5 mg/kg, sc), the serotonin precursor 5-hydroxytryptophan (5-HTP) (20 mg/kg, sc), the serotonin antagonist methysergide (1 mg/kg, sc), and naloxone in combination with methysergide. Naloxone, whether administered alone or in combination with methysergide, impaired sexual performance in castrated male rats, and in gonadally intact rats maintained on sweet solutions. Methysergide elevated sexual behavior in all groups, whereas 5-HTP tended to suppress such behavior. The results support the hypothesis that endogenous opiates play a role in the expression of male sexual behavior in rats. While subtle in intact animals this role may become crucial following the disruption of sex hormone supply. Serotonergic influence on male sexual behavior is inhibitory.

Animals↗
PubMed1985

Influence of intake of sweet solutions on the analgesic effect of a low dose of morphine in randomly bred rats.

The time course for the development of morphine tolerance, following prolonged sweet intake, was examined in randomly bred Sabra rats. Exposure to 3% glucose in 6 mM saccharin solution increased drinking by about three times as compared to rats supplied only with water. Suppression of the analgesic effect of morphine was already detectable after 24 h of intake and became progressively more marked within the next 5 weeks. These results support an active interaction between sweet consumption and endogenous opioids in randomly bred rats.

Animals↗
PubMed1985

Practical study of qualitative and quantitative sebum excretion on the human forehead.

Measurement of Sebum Excretion Rate (SER) in patients is a time-consuming test. It is now possible to measure SER 1 h after having degreased the forehead with a 70% ethanol solution. The skin surface lipids (SSL) collected during this time have similar composition to those collected for up to 7 h. A qualitative and quantitative study of sebaceous excretion, on 18 volunteers, from 1 to 7 h after having cleansed the forehead, showed that the refatting kinetics, in all subjects, obeyed the same mathematical law, independent of the subjects' individual SER.

Adult↗
PubMed1985

Bilateral optic nerve abnormalities associated with a 4-10 chromosomal translocation.

A neonate with ocular abnormalities and a chromosomal aberration is described. The patient demonstrates a typical choroidal coloboma involving the iris ciliary body and choroid of the right eye, bilateral optic pits-coloboma and a karyotype with a 4-10 chromosomal translocation. Although a random occurrence of the ocular phenomena and the chromosomal aberration cannot be ruled out, it is appealing to speculate about the possible association of the ocular colobomata and the chromosomal translocation harbored by this patient.

Choroid↗
PubMed1984

Ventral tegmental analgesia in two strains of rats: effects of amphetamine, naloxone and parachlorophenylalanine.

Pain sensitivity and analgesia induced by the stimulation of the ventral tegmentum (VT) were studied in 72 male rats of two lines, LC2-Hi and LC2-Lo, genetically selected for high and low rates of lateral hypothalamic self-stimulation, respectively. LC2-Lo rats were more sensitive to acute peripheral pain and developed a stronger analgesia than their LC2-Hi counterparts. In order to assess the pharmacological substrate of ventral tegmental stimulation-induced analgesia (VT-SIA), the effects of amphetamine (AMP, 21 animals), naloxone (NX, 24 animals) and parachlorophenylalanine (PCPA, 27 animals) injections were studied. VT-SIA was found to be clearly decreased by PCPA, slightly decreased by AMP and not significantly affected by NX. Ventral tegmental self-stimulation ( VTSS ) was increased by PCPA treatment. The comparison of VTSS and VT-SIA did not reveal any correlation between both phenomena. These data suggest that VT-SIA may be mediated by serotonin while catecholamines may have a modulatory role in this analgesia and that VTSS and VT-SIA seem to be governed by different neuronal systems.

Amphetamine↗
PubMed1984

Serum lectins from the scorpion Vaejovis spinigerus Wood bind sialic acids.

We have partially characterized the specificity of serum lectins from the scorpion Vaejovis spinigerus Wood. Agglutination, crossed-absorption and hemagglutination-inhibition patterns were similar but not identical to serum lectins from other members from the family Vaejovidae , and different from the Buthidae species studied so far. V. spinigerus serum lectins bind sialic acids and sialoconjugates , but also bind 2-keto-3-deoxyoctonate, uronic acids and N- acylaminosugars , all substances present in bacterial cell walls suggesting that they might be involved in defense functions.

Animals↗
PubMed1984

Separation of induction and expression of tight junction formation mediated by proteinases.

The formation of tight junctions can be induced in the human adenocarcinoma cell line HT 29 by treatment with trypsin at 37 degrees C. In contrast, after treatment of the cells with trypsin at low temperature (3 degrees C), no tight junctions were observed. However, abundant formation of tight junctions occurred when cells were treated with trypsin at 3 degrees C, washed with soybean trypsin inhibitor, and subsequently incubated at 37 degrees C. Thus, this protocol allows for the first time the temporal separation of the induction and assembly of tight junctions.

Adenocarcinoma↗
PubMed1984

Treatment of breast carcinoma recurrent after adjuvant chemoimmunotherapy.

Between July 1975 and June 1979, 194 patients with State II or III breast carcinoma were randomized to receive either L-phenylalanine mustard (L-PAM), cyclophosphamide and 5-fluorouracil and prednisolone (CFP), or CFP and BCG. Sixty-one patients have recurred despite the adjuvant chemoimmunotherapy trial. Fifty-three are evaluable for survival and 36 for response to chemo-hormonal therapy. Those treated with a chemo-hormonal regimen for their first recurrence exhibited a 53% objective response rate to cytotoxic therapy or a 35% response to hormonal therapy. Prior exposure to L-PAM, cyclophosphamide, or 5-fluorouracil did not preclude response to "salvage" therapy regimens containing those agents. Neither menopausal status, estrogen receptor content, size of the primary tumor, adjuvant treatment, nor extent of the recurrence had any effect on subsequent survival. Overall, the entire group exhibited median survival of 37 months from initial diagnosis and 13 months from recurrence. Unlike recurrent Hodgkin's disease, there was no demonstrable relationship between the length of the disease-free interval and the likelihood of subsequent response to cytotoxic or hormonal treatment. Comparison is made to the results of "salvage" therapy administered after three other large adjuvant treatment series.

Adjuvants, Immunologic↗
PubMed1984

Biphasic effects of chronic saccharin intake on pain responses of healthy and diabetic rats of two genetically selected strains.

Rats of the LC-2-HI strain, selected for high rates of self-stimulation, were supplied with a 3 mM saccharin solution. Within 1 week they developed markedly prolonged latencies to painful stimuli on a hot-plate. In contrast, a similar effect became manifest in LC-2-LO rats only after 3 weeks. Both strains of rats were made diabetic by injection of streptozotocin. LO rats showed more polydipsia and hyperglycemia than HI rats and, when drinking saccharin solution, developed cross-tolerance to morphine within about 2 weeks. It is assumed that saccharin consumption stimulates the release of endogenous opioid peptides, probably via stimulation of gustatory sweet receptors. The opioid peptides exert a biphasic effect: initially they raise the pain threshold, but at a later stage they cause chronic cross-tolerance to morphine.

Analgesia↗
PubMed1984

Transient renovascular hypertension in childhood.

Two children aged 18 and 30 months presented with severe renovascular hypertension. Initially, surgical intervention was postponed because of the patients' young age. Adequate control of the hypertension and reversal of its sequelae were achieved with aggressive medical management. At present, both patients, aged 9 and 12 years respectively, have discontinued all medication, have achieved normal growth, are normotensive and have normal renal function.

Antihypertensive Agents↗
PubMed1984

Ventral tegmental self-stimulation, sensory reactivity and pain reduction in rats selected for high and low rates of lateral hypothalamic self-stimulation.

Ventral tegmental self-stimulation (VTSS) was studied in 56 male rats of four genetic lines (LC1-Lo, LC1-Hi, LC2-Lo, LC2-Hi), which differed in their inherent tendencies to self-stimulate the lateral hypothalamus. It was found that LC2-Hi rats engage more in VTSS than do rats of the LC2-Lo line. No differences were observed between the LC1-Hi and -Lo lines. In a second experiment, the LC2-Hi and -Lo lines were compared as to peripheral pain thresholds (36 animals) and VT-induced-analgesia (21 animals). Genetically low self-stimulators of the LC2 selection program were found to be more sensitive to acute peripheral pain and to VT analgesic influences than are their high counterparts. Theoretical implications are discussed.

Animals↗
PubMed1984

Effects of chronically elevated intake of different concentrations of saccharin on morphine tolerance in genetically selected rats.

Sixty-four LC2-Hi and LC2-Lo female rats were chronically supplied with either water or a solution of 1, 3 or 30 mM of sodium-saccharin. Pain sensitivity, as well as its reduction by a 2.5 mg/kg morphine injection, were measured in a hot-plate test. High saccharin consuming LC2-Hi rats did not exhibit significant morphine-induced analgesia (MIA) compared to baseline, after 38 days of drinking of saccharin, irrespective of concentration. MIA of those rats were maintained on water was significant. In contrast, the low consuming LC2-Lo animals maintained either on water or on 1 and 30 mM saccharin showed significant MIA compared to baseline, following the same exposure period. The findings demonstrate that chronically elevated saccharin intake, activates an endogenous opiate system leading ultimately to cross-tolerance to the analgetic effects of morphine.

Animals↗
PubMed1984

Sialic acid binding lectins in the serum of American spiders of the genus Aphonopelma.

Multiple lectins were detected in the serum of three American species of the genus Aphonopelma (A. chalcodes, A. cochise and A. chiricawa) through tests of agglutination and crossed absorption with a panel of untreated and enzyme treated of vertebrate erythrocytes. Hemagglutination-inhibition experiments showed that a fraction of A. chalcodes serum lectins bind sialic acids and sialoconjugates although other related carbohydrates as N-acetyl-D-glucosamine and 2-keto-3-deoxyoctonate also are recognized. Results of these studies extend our observations about the presence of sialoconjugate binding lectins in members of the Chelicerata to species from the Order Araneae. At the present time the Chelicerata (horseshoe crabs, scorpions, whip scorpions and spiders), would constitute the only group of high taxonomic rank which includes species that exhibit certain common patterns in the specificity of their humoral lectins.

Animals↗
PubMed1984

Polyamine Biosynthetic Enzymes in the Cell Cycle of Chlorella: Correlation between Ornithine Decarboxylase and DNA Synthesis at Different Light Intensities.

During the life cycle of Chlorella vulgaris Beijerinck var vulgaris fa. vulgaris growing synchronously, the specific activity of ornithine decarboxylase peaked at the 2nd hour of the cycle, whereas that of arginine decarboxylase changed only slightly, increasing towards the end of the cycle. The endogenous level of putrescine and spermidine on a per cell basis increased gradually up to the 8th hour of the cycle, and declined thereafter. Thus, the peak of ornithine decarboxylase activity and the polyamine increase preceded both DNA replication (which took place between the 6th and 8th hours of the cycle) and autospore release (which started at the 8th hour). A 2-fold increase in the light intensity caused doubling of the DNA content, resulting in doubling of the number of autospores per mother cell. It also brought about a 2-fold increase in the specific activity of ornithine decarboxylase and polyamine content, the peaks being at the same hour of the cycle under high and low light intensities. The increase in cell number and polyamine content in a Chlorella culture grown under high light intensity was inhibited by alpha-difluoromethyl ornithine, a specific inhibitor of ornithine decarboxylase, this inhibition being partially reversed by putrescine.It is suggested that in C. vulgaris the sequence of events which relates polyamine biosynthesis to cell division is as follows: increased ornithine decarboxylase activity, accumulation of polyamines, DNA replication, and autospore release.

Journal Article↗