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Biomedical subjects

C C Hong

Publications and source records attributed to C C Hong.

At least 37 records · Page 2Linked to original sources
PubMed1994

Cosegregation of the endothelin-3 locus with blood pressure and relative heart weight in inbred Dahl rats.

OBJECTIVE: To determine whether the endothelin-1 or endothelin-3 genes are genetically linked with blood pressure and relative heart weight in segregating rat populations, in the context of an elevated dietary sodium chloride intake. METHODS: Endothelin-1 and endothelin-3 genotypes of rats in segregating populations, derived from crosses of Dahl salt-sensitive (SS/Jr) rats with contrasting inbred strains, including Lewis rats, spontaneously hypertensive rats and Dahl salt-resistant (SR/Jr) rats, were determined using restriction fragment length polymorphisms. Segregating populations were fed a high (8%)-sodium chloride diet. Linkage of genotype with blood pressure or relative heart weight was determined by analysis of variance. Chromosomal location of the rat endothelin-3 gene was determined by genotyping a panel of recombinant inbred strains. RESULTS: Two alleles for the endothelin-1 gene and three alleles for the endothelin-3 gene were identified. The endothelin-1 locus did not cosegregate with blood pressure or relative heart weight. The endothelin-3 locus cosegregated with blood pressure and relative heart weight in an SS/Jr x F1 (SS/Jr x SR/Jr) population, but not in populations containing a higher percentage of genes from the SR/Jr strain. The endothelin-3 and seminal vesicle protein-1 loci were linked and located on rat chromosome 3. CONCLUSION: The endothelin-3 gene is, or is linked to, a locus on chromosome 3 that regulates blood pressure and relative heart weight in inbred Dahl rats, and these effects were strongly dependent on the genetic background.

Animals↗
PubMed1991

cDNA cloning and chromosomal assignment of the endothelin 2 gene: vasoactive intestinal contractor peptide is rat endothelin 2.

Four members of the endothelin family of vasoactive and mitogenic peptides have been identified: human endothelins 1, 2, and 3 (ET1, ET2, and ET3, respectively) and mouse vasoactive intestinal contractor (VIC). To characterize the mRNA encoding ET2, a 192-bp fragment of the ET2 gene, amplified by the polymerase chain reaction from human genomic DNA, was used to screen cell lines and tissues for ET2 gene expression. ET2 mRNA was detected in a cell line (HTB119) derived from a human lung small cell carcinoma, and an ET2 cDNA was cloned from a cDNA library prepared from HTB119 mRNA. DNA prepared from human-mouse somatic hybrid cell lines was used to assign the gene encoding ET2 (EDN2) to the 1p21----1pter region of chromosome 1, demonstrating that EDN2 is not linked to genes encoding ET1 (EDN1; chromosome 6) and ET3 (EDN3; chromosome 20). Southern blot hybridization revealed a single gene in human and rat genomes that hybridized with the ET2 gene fragment, and the rat gene was cloned. The endothelin peptide encoded by the rat gene differed from ET2 at 1 of 21 residues and was identical to mouse VIC. We conclude that VIC is the mouse and rat analogue of the human ET2 gene.

Amino Acid Sequence↗
PubMed1980

Comparisons of alveolar and peritoneal macrophages: soluble protein, esterase, dipeptidyl aminopeptidase II, and proteinase inhibitor.

The content of soluble protein, nonspecific esterase, dipeptidyl aminopeptidase II (DAP II), and proteinase inhibitors was compared for alveolar (AM) and peritoneal (PM) wash cells of rats. The cells present in the wash fluids were 85-90% macrophages in the peritoneal wash and 95% in the alveolar wash. Macromolecular components were resolved from whole cell homogenates by polyacrylamide gel isoelectric focusing (PAGIF) on horizontal gels and were identified cytochemically. Banding patterns clearly indicated a larger number of esterase zones in peritoneal compared to alveolar macrophages and ten previously unrecognized isozymes of DAP II in peritoneal macrophages with only three evident in their alveolar counterparts. (On whole blood smears, these cytochemically demonstratable enzymes were limited to macrophages, although DAP II was seen also in some mast cell granules). A protein band similar to the M6 band of alpha-1-antitrypsin in human serum was seen both in alveolar and peritoneal wash preparations. In addition, nine other major trypsin-binding protein bands were observed in the peritoneal macrophages, including two bands not observed in the alveolar macrophage extracts.

Animals↗
PubMed1980

Naturally occurring lymphoblastic leukemia in guinea pigs.

Nine cases of lymphoblastic leukemia were observed in 4,500 guinea pigs from three guinea pig production colonies during a period of 3 years. Seven of the cases occurred in strain 2/N, one in 13/N and one in Dunkin-Hartley/FD. These guinea pigs were 5.5-29 months old and included two males and seven females. Clinically, the animals showed a variety of signs, such as enlargement of peripheral lymph nodes, posterior paralysis and terminal ataxia. Gross lesions were characterized by numerous white spots and enlargement of the lymph nodes and many internal organs. Hematologic examination showed leukocytosis with lymphoblasts predominating. Histologic and cytologic examination of affected tissues and cells revealed generalized infiltration of lymphocytic leukemic cells.

Animals↗
PubMed1978

Self-mutilation of the penis in C57BL/6N mice.

A major cause of male reproductive failure in a C57BL/6N mouse production colony is self-inflicted mutilation of the penis. The extent of the damage ranged from loss of the distal end to loss of the entire penis. From January 1974 to August 1976, 645 adult male mice with mutilated penis were removed from this colony--where the monthly census was 9500 mice, mated 1 male to 4 females using a continuous mating system. On necropsy, it was observed that the substance blocking the urethra in the penile stump resulted in urine retention, grossly distending the urinary bladder. Proteus mirabilis and other bacteria isolated from the urethral plugs were considered secondary invaders.

Animals↗
PubMed1978

Ectopic pregnancy in 2 guinea-pigs.

The foetuses were completely developed and were found in the peritoneal cavities of strain 13/N guinea-pigs in their 3rd pregnancies. One foetal placenta was attached to the left side of the peritoneal wall, the other adhered to the pyloric region of the stomach.

Animals↗
PubMed1978

Volvulus at the ileocaecal junction in germfree mice.

16 cases of intestinal volvulus were observed in a total of 200 inbred C57BL/6N, GR/N, and DBA/2N germfree mice during the course of 2 years. The volvulus was a twisting of the caecum at the junction of the ileum, caecum and colon, resulting in occlusion and death. In each case the caecum was greatly enlarged. During the same period no intestinal volvulus was seen in 5 other germfree strains or in F1 to F4 generations of identical strains of microflora-associated and conventionalized mice.

Animals↗
PubMed1978

Perputial gland abscess in mice.

Preputial gland abscesses were found in 321 (1.8%) of 17,422 mice from our production colonies. The lesions were observed only in males, and Staphylococcus aureus was isolated in pure culture from 84% of the cases. Experimental transmission of the disease was successfully accomplished through injection of Staphylococcus aureus into the penile urethra.

Abscess↗
PubMed1978

Chronic necrotizing mastitis in rats caused by Pasteurella pneumotropica.

Sixty-one of 2500 F344 rats were observed to have one to three enlarged and firm mammary glands. Pasteurella pneumotropica was isolated from all affected mammary glands. It was also routinely isolated from the feces of all cages and from the oral cavity of rats up to 6 weeks old, but not from the oral cavity of rats over 4 months of age. The organism was not isolated from clinically normal lactating mammary glands. Histopathological diagnosis of affected glands was chronic necrotizing mastitis.

Animals↗
PubMed1977

Conjoined twins and opocephaly in guinea-pigs: 4 cases of congenital malformation.

A case of opocephaly in inbred guinea-pig strain 2/N and another in strain 13/N, a conjoined twin and an opocephaly concurrent with conjoined twins in the Dunkin-Hartley/FD strain are described. The incidence of congenital malformations in the inbred strain 2/N and strain 13/N was 0-0013 and 0-0073% respectively. The incidence in the random-bred Dunkin-Hartley/FD strain was 0-0007%.

Abnormalities, Severe Teratoid↗
PubMed1977

Measurement of guinea pig body surface area.

The body surface area (BSA) of 50 adult 2/N guinea pigs of both sexes and varying age was measured by the skinning and paper weight technique, or calculated from two equations in which the animals' weight (W) alone or the weight and length (L) were known. The equations BSA = W2/3 x 8.054 and BSA = W0.425 x L0.725 X 3.545 were developed by the method of least squares. The differences between the values obtained by measurement and those obtained by either of the calculation methods were not statistically significant. Differences because of sex and age were also not significant.

Animals↗