Reinforcing effects for female hamsters of non-copulatory exposure to normal male hamsters

Naturally cycling female hamsters were run in a T-maze to determine their preference for exposure to an intact male enclosed in one goal box or a castrated male in the other goal box; physical contact with the goal animals was prevented. All animals preferred the intact male, but only on estrous days, and the preference was maintained even when no differential stimuli reached the choice point from the goal animals. The preference is interpreted as demonstrating that non-copulatory exposure to stimuli emanating from an intact male is reinforcing for an estrous female.     

Reliability of the acetabular teardrop as a landmark

Summary This study investigated the effect of tilt and observer reliability on radiographic measurements of the position of a prosthetic acetabular cup in seven dry bone pelves using the teardrop as a landmark. Coronal or sagittal tilt of more than five degrees was easily recognisable and there was effectively no observer variation in the measurements up to this limit. In addition, 90 out of 100 randomly selected antero-posterior pelvic radiographs from an outpatient department were not significantly rotated and 93 demonstrated a clearly defined teardrop. Measurements about the teardrop on routine radiographs are therefore sufficiently accurate to allow assessment of prosthetic position.

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La valeur du sourcil cotyloidien comme repère d'analyse radiologique

Résumé Cette étude, conduite sur 7 bassins secs, apprécie l'effet de l'inclinaison du bassin sur la qualité de l'analyse radiographique de la position d'une cupule prothétique de hanche en utilisant le sourcil cotyloïdien comme repère. Une inclinaison du bassin dans les plans coronal et sagittal est aisément détectable et il n'existe pas de variation d'analyse entre les différents observateurs en dessous de 5° d'inclinaison. De plus, sur 100 radiographies antéro-postérieures de bassin choisies au hasard dans les dossiers de consultation, 90 avaient été réalisées sans incidence particulièrement adaptée et l'on pouvait repérer facilement le sourcil sur 93% d'entre elles. Les mesures faites sur des radios de routine sont donc suffisamment précises pour permettre l'évaluation de la position d'une prothèse à partir du sourcil cotyloïdien.

     

Emergence of influenza A H1N2 reassortant viruses in the human population during 2001

A recombinant vaccinia virus encoding rotavirus protein NSP3 driven by an internal ribosome entry site (IRES) from the encephalomyocarditis (EMC) virus was able to abate protein synthesis in BSC1 cells by 25-fold, with as much as 30% of the remaining protein synthesis being NSP3. Hence NSP3 shuts off host cell protein synthesis down to the level seen during rotavirus infection but is unable to prevent translation from EMC IRES-driven genes. This effect was abolished by deletions in the eIF4G-binding (aa 274-313) and the dimerization (aa 150-206) but not the viral mRNA-binding (aa 83-149) domains, supporting that NSP3 functions in vivo as a dimer. Binding of eIF4G by NSP3 has been implicated in interfering with mRNA 5'-3' circularization, hence such circularization is essential for translation in mammalian cells.     

EEG delta power during sleep in young and old rats

Delta EEG power density, which has been viewed as a measure of intensity of NREM sleep, declines across the lifetime in humans, cats, and hamsters, but data in rats have been unclear. It is also uncertain whether older rats differ from younger animals in the degree of change in delta power during recovery sleep following short-term sleep deprivation. We have examined delta power density in NREM sleep under baseline conditions and following 48 h of sleep deprivation in young (3 months), middle-aged (12 months), and older (24 months) rats. The presence or absence of age effects was highly dependent on the method of normalizing the data. When expressed as a fraction of total NREM EEG power, there was no age effect on baseline delta power density, or on the change from baseline to recovery conditions. When expressed as a multiple of delta power in REM under the same condition, the younger rats had higher delta power density than the middle-aged and older rats. For all the ages combined, there was an increase in delta power density in the recovery condition. When examined by age, the younger rats (which started from a higher level of delta power density than the other groups) did not have an increase in delta during recovery; the middle-aged rats tended to, and the older rats (which started from lower baseline levels) significantly increased delta power density in the recovery condition. This suggests that the lower delta power seen during baseline in older rats is not due to decreased ability to generate delta activity.     

A clinical study of flurazepam

Eleven patients suffering from chronic insomnia were given 30 mg flurazepam for 28 nights. While EEG measures of total sleep time and sleep efficiency were improved, changes in sleep latency and intermittent waking time were small and nonsignificant. Subjective benefits in sleep were confined to the first 2 nights. There was neither increased nor decreased daytime sleepiness. Cognitive functioning was significantly decreased during the first 2 days, and patients were unaware of these changes. Simple motor tasks were relatively unaffected. Desalkylflurazepam concentrations showed significant accumulation over time, but were not predictive of sleep measures or daytime performance in individual subjects. The withdrawal period was characterized by subjectively disturbed sleep and daytime dysphoria.     

5-HT1A receptors: differential involvement in female and male sexual behavior in the rat

The peripheral administration of the serotonin type 1A (5-HT1A) receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH DPAT) inhibited lordosis behavior in ovariectomized rats primed with estradiol benzoate. 8-OH DPAT was ineffective at 0.01 mg/kg, whereas inhibition occurred at the 0.03, 0.1, 0.3, 1, and 3 mg/kg doses. On the other hand, 8-OH DPAT enhanced various measures of male sexual behavior both in males and in females treated chronically with testosterone propionate. In males, 1 mg/kg 8-OH DPAT reduced ejaculation latencies and the number of intromissions prior to ejaculation. In females, 0.1 and 1 mg/kg 8-OH DPAT increased mount frequencies. These data indicate differential involvement of 5-HT1A receptors in male and female sexual behavior. In view of these and other recent data the authors conclude that activity at 5-HT2 receptors facilitates, whereas activity at 5-HT1 receptors may either facilitate or inhibit lordosis behavior. Furthermore, it is proposed that 5-HT1A receptors mediate inhibitory effects, whereas 5-HT1B receptors mediate presynaptic, facilitatory effects of serotonin.     

Osteosarcomatosis

A review of the 690 cases of osteosarcoma in the radiographic file of the Armed Forces Institute of Pathology revealed 29 cases of "osteosarcomatosis" (multiple skeletal sites of osteosarcoma). Fifteen of these patients were 18 years old and under and manifested rapidly appearing, usually symmetric, sclerotic metaphyseal lesions. The remaining 14 patients were more than 18 years old and had fewer, asymmetric sclerotic lesions. In most patients (28 of 29), a radiographically dominant skeletal tumor was seen. Pulmonary metastases occurred in the majority of patients and were detected at the same time as the bone lesions. These 29 patients were studied with regard to demographic data and skeletal distribution and radiographic appearance of their lesions. As a result of the findings, a metastatic origin from a primary dominant osteosarcoma is favored over a multifocal origin as the basis for osteosarcomatosis. Osteosarcomatosis is more commonly encountered in the mature skeleton than has been previously recognized.