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Biomedical subjects

A Lock

Publications and source records attributed to A Lock.

13 recordsLinked to original sources
PubMed1982

Use of functional maps in renal scintigraphy to detect segmental arterial lesions.

Renography using a gamma camera, a minicomputer, [123I]orthoiodohippurate ([123I]OIH), and a canine model was employed to evaluate computer-generated maps of regional renal function. Renograms were obtained before and after ligations of the right renal arterial branch in four dogs, with subsequent angiographic and histologic confirmation of the lesions. Postoperative time-activity curves were normal. Washout and persistence index in three of four right kidneys showed regional abnormality. Functional renal mapping may provide a clinical technique for evaluating human renal vascular hypertension.

Animals↗
PubMed1981

Pathology and diagnosis of mousepox.

The pathologic changes of mousepox were studied during an outbreak at the National Institutes of Health in 1979. The most consistent lesions were necrosis of lymphatic tissues, especially the spleen, lymph nodes, and Peyer's patches. Hepatic necrosis and jejunal hemorrhage also were found. In two transmission studies, the disease was experimentally induced in BALB/cAnN and C3H/HeN-nu mice. Athymic mice were found to be highly susceptible, and they developed fulminant disease. The diagnosis was confirmed by demonstration of pox virions in infected tissues by electron microscopy, staining of viral antigen by immunoperoxidase methods, and by isolation of the virus in chorioallantoic membranes of hen's eggs and in cultures of chick embryonic cells.

Animals↗
PubMed1980

Subclinical scurvy in the guinea pig.

Twenty-eight guinea pigs from nine episodes of subclinical scurvy had diarrhea, weight loss and dehydration. The classical signs of scurvy were not seen. Microscopically the epiphyses were attenutated and irregular. The amount of osteoid was less than normal. Many guinea pigs had acute enteritis. In some there were many hemosiderin-laden macrophages in the intestinal lamina propria. All episodes were associated with either autoclaving food without adequate supplementation or other inadequate feed management practices.

Animals↗
PubMed1979

Antipyretic effect of acetaminophen suppositories in rats.

An animal model used yeast-fevered rats to measure the relative antipyretic effects of different commercially available acetaminophen-containing suppositories. A laboratory-prepared acetaminophen-containing suppository and placebo suppositories also were investigated. Release from the suppositories was measured in vitro. All acetaminophen products containing 600 mg of drug elicited significant decreases in the rectal temperature of fever-induced rats.

Acetaminophen↗
PubMed1978

tert-Butoxycarbanyl as a convenient protecting group in synthesis of potential centrally active dopamine derivatives.

Several pivaloyl and pivaloyloxy esters and amides of dopamine were synthesized for possible antiparkinson activity. The compounds were synthesized by select O- and N-acylation and N-methylation procedures. The tert-butoxycarbonyl function is an effective and easily removed nitrogen-protecting group for dopamine. Preliminary biological testing results showed that all compounds tested elicited a hypothermic response in mice, while only O,O-dipivaloyl-N,N-dimethyldopamine reversed reserpine-induced motor depression in mice. However, it is difficult to conclude from the preliminary data that the observed biological effects were due to central dopaminergic receptor stimulation.

Animals↗
PubMed1976

Absorption and distribution of radioactivity from suppositories containing 3H-benzocaine in rats.

The effects of the suppository vehicle, drug concentration, and nonionic surfactants on in vitro benzocaine dialysis through a cellulose membrane and on rectal absorption in rats of total radioactivity following administration of 3H-benzocaine were investigated. In vitro dialysis correlated quite well with in vivo absorption, and drug release was greater from water-soluble vehicles than from oleaginous vehicles. Inclusion of a nonionic hydrophilic or lipophilic surfactant in cocoa butter resulted in a statistically significant increase for in vitro drug release, while a lipophilic surfactant showed little effect in vivo and a hydrophilic surfactant depressed release in vivo. Both types of surfactant had small effects on release from polyethylene glycol. In vitro release of benzocaine from some commercially available suppositories was compared with experimental preparations. Variation in blood radioactivity following administration of the same concentration of 3H-benzocaine in the same dosage form in male and female rats is reported.

Animals↗
PubMed1976

Elastic energy storage in primary feather shafts.

It is proposed that the kinetic energy of a pigeon's wing, in hovering or slow forward flight, is transferred to the air at the end of the downstroke by a mechanism involving temporary storage of additional energy in bent primary feather shafts. Estimates of the amounts of energy which can be stored and recovered in this way are compared with the requirements of the theory. The hypothesis is not rejected, as far as present evidence goes. If is is correct, high-velocity pulses of calculable magnitude should be detectable in the wake.

Animals↗
PubMed1975

Absorption of 3H-benzocaine from ointments following rectal administration in rats.

Total radioactivity in the blood of rats for 5 hr following rectal administration of 3H-benzocaine in oleaginous, absorption, emulsion (water-in-oil and oil-in water), and water-soluble ointment vehicles was measured. The release was greatest from the water-soluble vehicle and followed the same relative order as seen in an earlier in vitro experiment. No intact benzocaine was found in the blood using radiochromatography. In vitro hydrolysis of benzocaine by rat blood did not occur as determined with the techniques of this experiment.

Administration, Topical↗