The ganglionic blocking properties of the cholinesterase reactivator, HS-6.

Following intravenous administration of the cholinesterase reactivator HS-6 (30 mg/kg), blood pressure fell (up to 50 mmHg) and maximal blood levels of HS-6 reached 242 microgram/ml. HS-6 attenuated the pressor response resulting from carotid occlusion and the depressor effect of vagal stimulation. Doses of HS-6 below those used to protect against soman in different animal species (10--30 mumol/kg) progressively blocked the ganglion-stimulating effects of nicotine and dimethylphenylpiperazinium but not the pressor effect following adrenaline, a pattern similar to that produced by hexamethonium but only 1/84 as potent. HS-6, like hexamethonium and mecamylamine, progressively blocked the contraction of the nictitating membrane of the cat resulting from preganglionic stimulation. The results indicate that HS-6 possesses ganglion-blocking properties at doses likely to be used in the protection against soman poisoning. The ganglion-blocking properties of the drug may be a factor in the beneficial effects of HS-6.     

A new method for studying human oocytes by light and electron microscopy

Since ovarian follicles appear to be randomly oriented with respect to the plane of the section, the method of sectioning and examining follicles at their maximum diameter described here allows direct comparison between oocyte populations of women and small differences can be detected. Re-sectioning for EM allows selected follicles of interest to be examined at a higher resolution.     

Effect of NaCl salinity in vivo and in vitro on ribonuclease activity in the halophyte Suaeda maritima

Ribonuclease (EC 2.7.7.17) activity in the obligate halophyte Suaeda maritima (L.) Dum. var. macrocarpa Moq. was studied in relation to salinity (increasing concentrations of NaCl) of incubation and growth media. In vitro, the addition of 50 to 400 m M NaCl did not affect ribonuclease activity. This result, which was also found for Phaseolus vulgaris , indicates that the hydrolase is insensitive to high saline concentrations. The subcellular distribution of RNase activity did not change significantly with the salinity of the medium or with the age of the plant. The microsomal ribonuclease activity expressed on a fresh weight basis represented in every case less than 6% of the total activity. After 23 days of culture, the absence of salt stimulated the activity of soluble ribonuclease in aerial parts of Suaeda ; inversely, the capacity of the enzyme was lower under optimal saline conditions (130 m M NaCl). This was also evidenced by transfer of whole plants from a non-saline to a saline medium. Such a saline shock caused a decrease followed by a stabilization of the capacity of ribonuclease from Suaeda . The influx of NaCl in the tissues lowered the activity of the hydrolase.     

Changes in the content of carbohydrate-containing proteins in the liver of rats chronically exposed to pesticides combined with total gamma irradiation

A study was made of the chronic effect of pesticides, within a wide range of doses, combined with whole-body gamma-irradiation, on the content of carbohydrate-containing proteins of rat liver. The extent to which disturbances in the carbohydrate-containing protein metabolism were manifest was shown to depend upon dose and time of action of the damaging factors. As determined by certain parameters, the combined effect of pesticides and gamma-radiation at the biochemical level was additive, and it was more than additive as estimated by a number of other tests.     

Cardioprotective effect of prostacyclin and 7-oxo-PGI2 in rats against chronic isoproterenol damage

Isoproterenol (ISO) was injected in 5 mg/kg i.p. doses to rats, daily for two weeks. We evaluated the developed myocardial hypoxia and necrosis quantitatively by histological methods. To follow the time course of cardioprotection prostacyclin or 7-oxo-PGI2 were injected daily, i.p. 5, 30 min and 1, 2, 3, 4 hours before or after the ISO to groups of ten rats, respectively. Cardioprotection was defined as the reduction of necrotized areas and was expressed as percentage change compared to the control (saline treated) group. 1 microgram/kg PGI2 and 50 micrograms/kg 7-oxo-PGI2+ showed nearly equipotent cardioprotection (37.3-7.9% and 38.3-6.8%, respectively). The peak effect of both compounds appeared when injected prior to ISO in the 120. min but the action of 7-oxo-PGI2 was more prolonged. The different doses of prostacyclin analogs given after the ISO injection were ineffective with the exception of 50 micrograms/kg 7-oxo-PGI2 (29.75 +/- 5.2%).     

The radiography of mummies of ancient Egyptians

In recent times 193 mummies of ancient Egyptians have been X-rayed. The sources of the specimens are given followed by a brief summary of the medical findings.     

Nucleotide ratios and quantitative RNA changes in potato plants elicited by photoperiod and temperature

The nucleotide composition of potato plants, Solanum tuberosumL., grown under four environmental regimes was studied. Althoughthere were marked quantitative differences in RNA followingthe temperature and photoperiod treatments as previously observed,nucleotide composition of all types of RNA did not change appreciably. ¹ Scientific Journal Series Article Number 7642 of the MinnesotaAgricultural Experiment Station. (Received August 23, 1971; )