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Biomedical subjects

D J Nash

Publications and source records attributed to D J Nash.

At least 37 records · Page 2Linked to original sources
PubMed1986

Synthesis and antihypertensive activity of 4-(cyclic amido)-2H-1-benzopyrans.

The synthesis and antihypertensive activity of a series of novel 4-(cyclic amido)-2H-1-benzopyran-3-ols, administered orally to conscious spontaneously hypertensive rats, are described. The effects of lactam ring size, the presence of heteroatoms in the lactam ring, substitution at C(2) and C(3), relative stereochemistry at C(3) and C(4), and aromatic substitution pattern on the blood pressure lowering activity of this series have been determined. The key compound 2 from this work [BRL 34915; (+/-)-6-cyano-3,4-dihydro-2,2-dimethyl-trans-4-(2-oxopyrrolidin-1- yl)-2H-1-benzopyran-3-ol] has been resolved, and antihypertensive activity was found to reside primarily in the (-) enantiomer. The key step in the preparation of this class of compounds is the action of a cyclo amidic anion on an appropriate epoxide. Another approach, involving a cyclization step to the lactam was found to be more convenient in certain cases, particularly in forming the cis analogue of compound 2. Compound 2 has been shown to possess a novel mechanism of action, and it has been selected for progression to the clinic.

Animals↗
PubMed1983

Ontogeny and adult behavior of mice with congenital neural tube defects.

Effects of abnormal neural tube development were studied in immature and adult mice. The behavior of affected adult mice was found to resemble that of mice that exhibit the "waltzer syndrome." Behavioral ontogenetic studies indicate that effected mice are deficient in labyrinthine responses as shown by the late development or lack of negative geotaxic behaviors and the delayed loss of pivoting behavior. Retarded maturation of neural responses was indicated by a delay in the appearance of the startle response. Evidence that circling behavior in adult mice of the "waltzer syndrome" may be a result of central nervous system disorders alone, or in concert with abnormalities of the inner ear, was provided by the fact that open field activity was increased in affected mice that exhibit circling behavior as adults.

Age Factors↗
PubMed1982

Genetic dependent transmission of Eimeria separata from Rattus to three strains of Mus musculus, an abnormal host.

We examined susceptibility of several strains of mice to Eimeria separata. Mice of the following coat-color genotypes were inoculated with 2 X 10(4) sporulated oocysts of E. separata isolated from Rattus norvegicus: random-bred (aabbCC and A-bbCC), Balb/C (AAbbcc), Balb/Gw (AABBcc), Z/Gw (aaBBcc), and Swiss NLW (cc). Allele designations are A = agouti, a = nonagouti, B = black, b = brown, C, c = albino. Eimeria separata completed its life cycle with oocyst production in all male and female random-bred (aabbCC), Balb/Gw and G/Gw mice. The reproductive index of E. separata in Balb/Gw mice was significantly lower (P less than or equal to 0.05) than that of the other mouse strains. Among the random-bred mice, E. separata had a significantly lower (P less than or equal to 0.05) mean reproductive index in male than in female hosts. Patent period and oocyst length/width indices remained constant irrespective of host genus. This is the first documentation that genetic factors play a role in susceptibility of mice to the rat coccidium, E. separata.

Animals↗
PubMed1982

Sagittal growth trends of the development of cleft palate in mice homozygous for the "paddle" gene.

Paddle is a lethal, single recessive gene mutation in the mouse which results in a large median cleft palate and chondrodystrophy. Comparative cephalometric measurements on the growth of the normal and paddle fetal craniofacial complexes were made to determine the cause of cleft palate in paddle. Two methods of cephalometric measurements were used with 20 parameters analyzed. Both methods revealed a reduction in maxillary and mandibular growth, and a reduced cranial base angle which did not allow forward movement of the tongue under the primary palate, and hence obstructed shelf movement.

Animals↗
PubMed1979

Ontogenetic study of the Miwh gene in mice.

Ontogenetic and adult behavioral tests were conducted on an extreme non-agouti strain of mice carrying the Miwh mutation. Except for startle response, no significant differences were seen in any aspect of the preweaning reflex and neuromuscular tests. The lack of startle response seen in Miwh/Miwh and Miwh/+ mice can be attributed to abnormalities found in the inner ear of these genotypes. Among adult mice, significant differences were found in the open field and visual cliff tests.

Animals↗
PubMed1979

Ontogeny of behavior in mice selected for large size.

Development of 13 reflex responses and behavioral components of mice from the Goodale Giant inbred strain (G/Gw) was compared to that of a sample of 61 pups from a random-bred strain. Significant differences were observed between groups for several responses, but the direction of these differences was not consistent. Effects of rapid growth and increased size in G/Gw mice did not directly affect behavioral maturation.

Age Factors↗
PubMed1977

An electrophoretic description of five species of squirrel.

1. The blood serum proteins of five species of Nearctic squirrels were electrophoretically examined. 2. Protein polymorphism was detected in all the species described. 3. The use of the mean relative mobility of specific proteins was shown to be a valuable aid in distinguishing species.

Animals↗
PubMed1975

An unusual two-tailed mouse.

A malformation that resulted in the formation of 2 complete tails is described in a mouse that was heterozygous for the sex-linked gene Bent-tail (Bn). One of the tails appeared normal and contained 29 vertebrae, whereas the other tail consisted of 27 vertebrae and had several bends or kinks in it and also had malformed vertebrae similar to those described for the Bn gene. A comparison of the malformation with previously described bifurcated tail conditions in the mouse is presented. It is possible that this 2-tailed mouse represents a special case of X-chromosome inactivation.

Animals↗