Biomedical subjects

K Dong

Publications and source records attributed to K Dong.

43 records · Page 3Linked to original sources

PubMed1993

The retroesophageal subclavian artery--a case report and review.

In an 80-year-old Japanese male cadaver, the right subclavian artery originated from the aortic arch distal to the origin of the left subclavian artery, i.e., it was the last branch of the aortic arch. It coursed obliquely upwards and to the right behind the esophagus and trachea heading for the superior thoracic aperture. Its area of distribution was normal. Here, we describe this rare anomaly, and discuss its morphologic types, development, incidence, common associated anomalies and clinical correlations.

Aged↗

PubMed1993

Unique course of the ovarian artery associated with other variations.

In a Japanese female cadaver, the left ovarian artery originated from the abdominal aorta superior to the level of the renal vessels. Accompanied by 2 veins, it coursed laterally to the upper pole of the left kidney, then inferiorly along its posterolateral aspect. Two vessels branched from it; the first went to the left suprarenal gland as a substitute for the missing left inferior suprarenal artery, whereas the second supplied the diaphragm as a supernumerary inferior phrenic artery. The venae comitantes drained into the left renal vein. Associated unusual findings were (1) external lobation of the left kidney, (2) supernumerary left renal artery, and (3) the uterine artery being the main arterial supply to the left ovary. The aberrant course of the ovarian artery may have resulted from an abnormal descent of the left ovary under the influence of a wandering gubernaculum during development. Our report also points to the potential for an ectopic artery, i.e. the ovarian to be located in a place other than its definite pelvic position.

Arteries↗

PubMed1992

Synergism of chlorpyrifos against the German cockroach, Blattella germanica.

Of fifteen compounds tested as synergists for chlorpyrifos against susceptible and resistant strains of Blattella germanica, the German cockroach, eleven were active against the resistant strain but only seven were synergistic against the susceptible strain. Overall, the most effective synergist was S,S,S-tributyl phosphorotrithioate (DEF) followed by phenyl saligenin cyclic phosphonate (PSCP) and two substituted N,N-dimethylcarbamates: SK-102 and SK-37. The most effective synergist for overcoming chlorpyrifos resistance was SK-37 which reduced the resistance ratio by 3.2-fold. Four other synergists which reduced chlorpyrifos resistance, in order of their effectiveness, were: SK-102 > PSCP > DEF > tridiphane. The potential usefulness of these synergists for German cockroach control is discussed.

Animals↗

PubMed1992

Cloning and functional expression of a mouse gonadotropin-releasing hormone receptor.

GnRH plays a pivotal role in the reproductive system, and GnRH analogs have wide therapeutic applications ranging from the treatment of prostatic cancer to infertility. Determination of the predicted structure of the GnRH receptor (GnRHR) would illuminate the mechanisms of receptor activation and regulation and allow directed design of improved GnRH analogs. We report the cloning of a cDNA representing the mouse GnRHR and confirm its identity using Xenopus oocyte expression. Injection of sense RNA transcript leads to the expression of a functional, high affinity GnRHR. Expression of the GnRHR using gonadotrope cell line RNA, however, is blocked by an antisense oligonucleotide. In situ hybridization in the rat anterior pituitary reveals a characteristic GnRHR distribution. The nucleotide sequence encodes a 327-amino acid protein which has the seven putative transmembrane domains characteristic of G protein-coupled receptors, but which lacks a typical intracellular C-terminus. The unusual structure and novel potential regulatory domain of the GnRHR may explain unique aspects of its signal transduction and regulation.

Amino Acid Sequence↗

PubMed1992

A retrograde fluorescence double-labeling study of the cat's optic nerve cell which has a bifurcating axon.

Injection of the fluorescent tracers, Evans Blue (EB) and 4'-6-Diamidino-2-phenylindole dihydrochloride hydrate (DAPI) or Fluoro-Gold (FG) into the dorsal nucleus of the lateral geniculate body (dLGN) and the ipsilateral superior colliculus (SC) of adult cats demonstrated the existence of double-labeled optic nerve cells in the retina denoting that their axons bifurcate and project to both of these structures. These cells were seen in the temporal half and dorsal-dorsonasal and ventral-ventronasal octants of the ipsilateral retina and accounted for 11.5% of all the labeled cells. On the contralateral side, they were seen in the entire retina and accounted for 13.7% of all the labeled cells.

Animals↗

PubMed1981

Plasmid deoxyribonucleic acid replication in Streptomyces griseus.

A series of electron micrographs showing the presence of different molecular forms representing various replication stages of plasmid deoxyribonucleic acid from Streptomyces griseus was obtained. Based upon an analysis of these electron micrographs, a tentative model for plasmid deoxyribonucleic acid replication in S. griseus is proposed.

DNA Replication↗

PubMedDate not supplied

kdr-Type resistance in insects with special reference to the German cockroach, Blattella germanica.

The phenomenon of knockdown resistance (kdr) was first noted in the housefly (Musca domestica), and has subsequently be found (i.e. kdr-type resistance) in several other insect pests including the German cockroach (Blattella germanica). This type of resistance causes insensitivity of the nervous system to pyrethroids, DDT and a limited number of sodium channel neurotoxins. In the German cockroach, kdr-type resistance is incompletely recessive, monogenic and not sex linked or due to cytoplasmic factors. Additionally, kdr-type resistance is not associated with a change in sodium channel density. kdr or kdr-type loci are tightly linked or identical to the para-homologous sodium channel locus in German cockroach, housefly and tobacco budworm (Heliothis virescens), suggesting that kdr and kdr-type resistance are due to mutations in the para-homologous sodium channel gene. kdr-Type resistance in the German cockroach appears similar, although not necessarily identical, to kdr in houseflies.

Animals↗