Wistar rats, deprived of food for 15 h, were injected with B-HT 920 and 20 min later presented with their normal diet in their individual home cages. The parameters considered were latency to feeding and food intake which was determined 0.5, 1, 2, 3, 6 and 24 h later. B-HT 920 significantly reduced latency to feeding at 0.1, 0.5 and 1 mg/kg; food intake was increased by doses of 0.05 and 0.1 mg/kg 3 and 6 h after treatment and decreased by a dose of 1 mg/kg at 3 h. The amount of food eaten over a 24 h period by the various groups did not differ. At this time rats received a second injection of the drug at the same dosages, and preweighed food was presented again 20 min later. We confirmed that latency to feeding is lowered by B-HT 920 at 0.1, 0.5 and 1 mg/kg, doses which also induced feeding in sated rats within the first half-hour and even after 1 h in the case of the highest dose. Since penile erection and stretching and yawning, signs typically induced by all DA D2 agonists, were observed after B-HT 920 at 0.05, 0.1 and 0.5 mg/kg, discussion centres on the possible mechanisms involved in the B-HT 920-induced effects.

Analysis of Variance↗

PubMedDate not supplied

A comparative study of B-HT 920 and diazepam in the X-maze feeding test.

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Analysis of Variance↗

PubMedDate not supplied

Inability of (-)deprenyl to modify copulatory performance in the male rat, whether or not stimulated by the selective D2 dopamine agonist SND 919.

Intraperitoneal injection of the selective D2 dopamine agonist SND 919 (0.1 and 1 mg kg-1) significantly accelerated the copulatory behaviour of sexually-active rats, diminishing the number of mounts, intromissions and latency to ejaculation. Subchronic (-)deprenyl did not produce any significant effect on the copulatory behaviour of sexually-active and -inactive male rats or modify the sexual stimulation exerted on the same sexually-active rats by SND 919, when acutely injected at 1 mg kg-1.

Animals↗

PubMedDate not supplied

Inhibitory effects of the cannabinoid agonist HU 210 on rat sexual behaviour.

The present study investigates the effects induced by the cannabinoid agonist HU 210 (25-100 microg/kg, administered intraperitoneally [i.p.]) on the following parameters: (a) sexual behaviour of male rats, categorised on the basis of seven consecutive mating pretests as sexually active (SA) and sexually inactive (SI) and (b) sexual receptivity of ovariectomised female rats displaying hormonally induced heat. The data obtained show that HU 210, administered in acute or subchronic mode (once daily for 7 and 14 days), impaired the copulatory pattern of SA rats in a dose- and mode-dependent manner, decreasing their sexual drive, mainly as represented by an increase in mount and intromission latencies, and affecting ejaculation mechanisms (represented as a decrease in intromission frequency and increase in ejaculation latency). After subchronic treatment with the highest dose had been suspended for 2 weeks, SA males' performance was still impaired. In SI rats, acute injections of the drug (25 and 50 microg/kg, i.p.) at the higher dose increased contact latency and decreased genital exploration time towards the female. Acute HU 210 (25-100 microg/kg, i.p.) also inhibited female sexual behaviour, potently reducing lordosis quotient and lordosis intensity.

Animals↗

PubMedDate not supplied

Behavioural effects of the dopamine D3 receptor agonist 7-OH-DPAT in rats.

The putative selective dopamine (DA) D3 receptor agonist, 7-OH-DPAT (25-4000 micrograms kg-1), enhanced stretching-yawning and penile erection in male rats, besides respectively increasing and decreasing sedation at low (25-200 micrograms kg-1) and high (1600 and 4000 micrograms kg-1) doses and inducing stereotypy from 800 micrograms kg-1 upwards. The DA D2 antagonist, (-) eticlopride (10 and 20 micrograms kg-1), antagonized stretching-yawning and penile erection induced by a low dose of 7-OH-DPAT (50 micrograms kg-1) but not those produced by high doses (1600 and 4000 micrograms kg-1), when stereotyped behaviour, on the other hand, was potently inhibited. Comparative experiments performed with the DA agonist SND 919 gave similar results.

Animals↗

PubMedDate not supplied

Genetic engineering of structural protein polymers.

Genetic and protein engineering are components of a new polymer chemistry that provide the tools for producing macromolecular polyamide copolymers of diversity and precision far beyond the current capabilities of synthetic polymer chemistry. The genetic machinery allows molecular control of chemical and physical chain properties. Nature utilizes this control to formulate protein polymers into materials with extraordinary mechanical properties, such as the strength and toughness of silk and the elasticity and resilience of mammalian elastin. The properties of these materials have been attributed to the presence of short repeating oligopeptide sequences contained in the proteins, fibroin, and elastin. We have produced homoblock protein polymers consisting exclusively of silk-like crystalline blocks and elastin-like flexible blocks. We have demonstrated that each homoblock polymer as produced by microbial fermentation exhibits measurable properties of crystallinity and elasticity. Additionally, we have produced alternating block copolymers of various amounts of silk-like and elastin-like blocks, ranging from a ratio of 1:4 to 2:1, respectively. The crystallinity of each copolymer varies with the amount of crystalline block interruptions. The production of fiber materials with custom-engineered mechanical properties is a potential outcome of this technology.

Amino Acid Sequence↗

PubMedDate not supplied

Anthropometry fails in classifying bone mineral status in postmenopausal women.

This study tested two hypotheses: (1) that simple anthropometric parameters can be used to identify patients at risk of decreased bone mineral content and (2) that an inverse relationship exists between waist:hip ratio (WHR) and bone mineral density (BMD). Bone mineral content (BMC) and BMD were evaluated by dual-energy X-ray absorptiometry in 1873 free-living women. Of these, 1819 (97%) were post-menopausal. One thousand and thirteen women (54%) had normal BMD, 705 (38%) osteopenia and 155 (8%) osteoporosis. Body weight (Wt), body mass index and arm muscle and fat areas were significantly lower in osteoporotics than osteopenics (p < 0.0001) and in these latter than controls (p < 0.0001). However, values of WHR were similar in all groups (p = ns). Body weight was the anthropometric parameter better correlated with BMC (rho = 0.650, p < 0.0001) and only Wt and age were identified as significant predictors of bone mineral status (normal-BMD/osteopenic/osteoporotic) at polytomous logistic regression (p = 0.0001 for each). However, Wt could not be employed as an indicator of bone mineral status at the individual level because of high variations in BMC for the same level of Wt. Under- (< 5th percentile) and normal-Wt (5th-95th percentile) women had the same frequency of osteopenia (39%) while it was lower in over-Wt (> 95th) women (13%). The frequency of osteoporosis was higher in under- than normal-Wt women (37 vs 7%) and none of the over-Wt women had osteoporosis. This study shows that: (1) simple anthropometric measurements cannot be used to select subjects at risk of decreased BMC and, (2) BMD does not vary with WHR.

Absorptiometry, Photon↗

PubMedDate not supplied

Epilepsy with typical absence seizures with onset during the first year of life.

Absence epilepsy with multiple daily seizures and onset at the age of 6 and 1/2 months in a healthy female child with normal development is described. EEG-video recording revealed typical absence seizures (vacant staring and interruption of motor activity) and complex absences (as above, plus raising of the eyeballs, slight beatings of the eyebrows, and forward propulsion of head and shoulders). The absences were accompanied by bilateral symmetrical 3-Hz spike-wave discharges preceded, and at times followed, by bilateral frontoparietal theta activity coinciding with onset and termination of the absence seizures. The seizures regressed with nitrazepam therapy. At age 3-years, the child is seizure-free and shows normal neurologic development.

Electroencephalography↗