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Biomedical subjects

K Dong

Publications and source records attributed to K Dong.

At least 37 records · Page 2Linked to original sources
PubMed1996

Retrograde fluorescent double-labeling study of bilaterally projecting retinal ganglion cells in albino rats at different stages of development.

Injection of the fluorescent tracers 10% Evans blue (EB) and 4% fluoro-gold (FG) into the right and the left dorsal lateral geniculate nucleus, respectively, of albino rats at different stages of development demonstrated the presence of double-labeled retinal ganglion cells that projected bilaterally into both the dorsal lateral geniculate nuclei (dLGN). Findings confirmed that the distribution of these double-labeled cells was gradually reduced after birth, being confined to the peripheral temporoventral quarter (temporal-ventral crescent) of the retina after postnatal day 15. We estimated the proportion of double-labeled cells to total labeled cells in the same area at different stages of development (0-90 days); values ranged from 35.3% in the neonate to 5.27% in the adult rat which suggests that the majority of double-labeled cells and/or their axons were lost early in development. That a small number of ganglion cells were observed to project bilaterally in the adult rats suggested that these cells conduct the same visual information to both hemispheres throughout the animal's life.

Animals↗
PubMed1996

Demonstration of direct input from the retina to the lateral habenular nucleus in the albino rat.

The projection from the retina to the habenular complex was studied using fluorescent retrograde tracers in the albino rat (Wistar, Japan Clea). Following separate unilateral injections of Fluoro-Gold (FG), Fluoro-Ruby (FR), or 4-acetamido,4- isothiocyanostilbene-2,2'-disulfonic acid (SITS) into the lateral habenular nucleus (LHB), a small population of ganglion cells was labeled sporadically, predominantly those in the nasal retina contralateral to each injection site. Most of them were small cells, ranging from 9 to 16 mu m in diameter, roughly corresponding to the type III ganglion cell in the rat retina. Additionally, all of the structures previously described as regions projecting to the LHB were confirmed. Upon re-examination of previous brain sections of albino rats which had undergone monocular enucleation, degenerating retinal nerve axons and/or their terminals, stained by a modified selective silver impregnation method, were observed in the well-documented end regions of retinal afferents as well as the LHB. The degenerating retino-habenular nerve terminals were distributed sparsely and restricted mainly to the caudal part of the LHB contralateral to the side of ocular enucleation. The present experimental data provide evidence for the existence of a non-image forming retino-habenular pathway in the albino rat. We suggest that, besides serving as a point of convergence for some of the major conduction channels of the limbic and striatal systems, the LHB may play more general integrative roles, including participation in the integration of visual information.

4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfo↗
PubMed1996

Correlation between different types of retinal ganglion cells and their projection pattern in the albino rat.

Injecting Fluoro-Gold (FG) and Evans-Blue (EB) into the right dLGN and SC in the adult albino rat, ipsilaterally projecting double-labeled retinal ganglion cells were mainly seen in the ventrotemporal crescent. They were mainly large sized cells. The ipsilaterally projecting double-labeled cells tended to have larger somata than the single- and double-labeled cells projecting to the contralateral superior colliculus and/or dorsal nucleus of the lateral geniculate body.

Animals↗
PubMed1996

A case of the bilateral superficial brachial arteries which continued to the radial arteries in the forearms.

During the dissection course of Kobe University School of Medicine, we found the bilateral superficial brachial arteries that continued to the radial arteries in a 90-years-old female cadaver. Each superficial brachial artery is classified Arteria brachialis superficialis lateralis inferior. This artery directly continued to the radial artery in the forearms on each side. Anomalous branching patterns of the (proper) brachial artery in this case belong to the type 7 of Adachi's classification. The incidence and embryological aspects of this anomalous arterial branching are discussed.

Aged↗
PubMed1995

A retrograde double-labeling study of uni- and bilaterally projecting retinal ganglion cells that project to the superior colliculi after unilateral eye removal at birth in the albino rat.

By injecting Fluoro-Gold and Evans-Blue into the right and left superior colliculi of the normal adult albino rats, bilaterally projecting retinal ganglion cells were labeled in the ventrotemporal crescent accounting for 37.9% of all the labeled cells, whereas in 0- and 5-day unilaterally enucleated rats these were found in the lower half of the retina accounting for 64.8% and 80.6%, respectively. Furthermore, they tended to have larger somata (type I cells).

Animals↗
PubMed1995

Bifurcated projections of retinal ganglion cells bilaterally innervate the lateral geniculate nuclei in the cat.

Cats were injected with the fluorescent retrograde tracers, Fluoro-Gold (FG) and Evans Blue (EB), into the left and right lateral geniculate nuclei (LGN), respectively. About 4.56% of the ganglion cells in the temporal retina were double-labeled by these dyes. 4.7% of these cells were of the large type, 30.3% were of the medium type, and 65% were classified as cells of the small type. These results indicate that members of all three ganglion cell size classes, mainly those of small type, bilaterally innervate the LGN via axonal bifurcation.

Animals↗
PubMed1995

A retrograde double-labelling study of retinal ganglion cells that project ipsilaterally to vLGN and LPN rather than dLGN and SC, in albino rat.

We studied ipsilaterally projecting, double-labeled retinal ganglion cells that have bifurcating axons by retrograde fluorescent double-labeling in albino rats. Ten albino (Wistar, Japan Ceca) rats of either sex, weighing 350-400 g were used. With the rats in a state of deep anesthesia, we pressure-injected 0.02 microliter of 15% Evans blue (EB) into the right ventral lateral geniculate nucleus (vLGN), and 4% Fluoro-gold (FG) iontophoretically into the right posterior lateral thalamic nucleus (LP). The animals were perfused with formol-saline 48-72 h later and both the brain and eyes were exercised. The brain was sectioned coronally, and each retina was removed and mounted flat on a glass slide. Double-labeled cells were found in the ventral temporal crescent of the retina. In one animal and total number of ipsilaterally labeled cells was 566, and the percentage of double-labeled vLGN and LP projecting cells, single-labeled vLGN projecting cells, and single-labeled LP projecting cells were 29.8, 58.8 and 11.3, respectively.

Animals↗
PubMed1995

A study of double-labeled retinal ganglion cells from the superior colliculus in the developing albino rat.

We studied the distribution pattern and percentage of bilaterally projecting, double-labeled retinal ganglion cells in the albino rat by the retrograde fluorescent double labeling. Forty-five albino (Wistar, Japan Clea) rats of either sex and of different stage of development ranging in age from the day of birth (Day 0) to Day 30, were used. With the rats under deep anesthesia, we pressure injected 0.02 microliter of 15% Evans blue (EB) and 0.02 microliter of 4% Fluoro-gold (FG) into the right and left superior colliculi, respectively; for rats older than 5 days, the volume of each tracer was 0.04 microliter. The animals were perfused with formol-saline 48 to 72 h later and the brain and eyeballs were excised and sectioned. Double-labeled cells were found over almost the entire retina, with the concentration in the lower temporal crescent in rats up to day 1; concentration gradually shifted to the ventral half between days 5 and 10. After day 15, double-labeled cells were found only in the ventral-temporal crescent of the retina, which is the pattern in the adult rats. The percentages of retinal ganglion cells that were double-labeled at days 0, 1, 5, 7, 10, 15, 20, 25 and 30 were 60.2, 51.6, 60.5, 57.6, 62.2, 60.7, 55.7, 45.2, and 39.1, respectively. After day 10, the percentage of such cells decreased steadily.

Animals↗
PubMed1995

[Induced expression of whiG, a gene crucial for sporulation of Streptomyces coelicolor].

whiG gene has been subcloned into Streptomyces expression vector pAK203 containing inducible promoter tipA. The expression of whiG gene promoted the spore formation of S. coelicolor J1501 and recovered the sporulation ability of whiG-deficient S. coelicolor C71. Increased amount of whiG gene product was detected by Western blot hybridization after induction of thiostrepton. It will be helpful for the future study of in vitro transcription of whiG-dependent promoters.

Gene Expression Regulation, Bacterial↗
PubMed1995

Establishment and characterization of two cell lines derived from human transitional cell carcinoma.

Two continuous cell lines derived from the neoplastic urothelium had been maintained in culture for more than two years. The first cell line derived from the urothelium of a fusion papillocarcinoma on the left lateral wall of the bladder was designated as TBC-1 and grown in vitro for more than 150 generations. The second cell line derived from the urothelium of a papillocarcinoma in the left renal pelvis was designated as TPC-1 and grown in vitro for more than 100 generations. Characterization studies made on both cell lines showed that the cells had a rapid doubling time, exhibited multilayering and produced tumors in sc of BALB/c. Tumor nodules that produced sc of BALB/c kept similar cellular and pathological features to those of the primary biopsy specimens under light and electron microscopes. TPC-1 cell line exhibited a three-dimensional structure of transitional epithelium on the nylon-mesh disk which was coated with a layer of rat tail collagen. Both TBC-1 and TPC-1 cell lines formed colonies in soft agar. Their forming rates were 35% and 28%, respectively. The chromosome number of TBC-1 cells ranged from 17 to 84, with a modal number of 54; whereas that of TPC-1 cells ranged from 28 to 139, with a modal number of 49. The TBC-1 cells showed mutant p53 and ras p21 protein expression and expressed weakly ABH blood group isoantigens. Analysis of lactic dehydrogenase (LDH) isozymes showed the highest levels of LDH isozyme 4 sonicated cell lysates of TBC-1 and TPC-1 respectively.

Adult↗
PubMed1995

[The effect of hirudo on proteinuria, lipid metabolism and coagulation system in the patients with chronic glomerulonephritis].

Renal biopsy was performed in 31 cases of primary glomerulonephritis and the effect of Hirudo in these patients observed. The results revealed that proteinuria decreased significantly, serum albumin increased significantly and cholesterol, triglyceride reduced significantly 4 weeks after treatment with Hirudo (P < 0.01 or P < 0.05); Fibrinogen and platelet aggregation reduced significantly (P < 0.01). However, platelet count, partial thromboplastin time, bleeding and clotting time did not change (P > 0.05); urine NAGase decreased significantly (P < 0.01). It is concluded that Hirudo may decrease proteinuria and alleviate renal parenchymal damage.

Animals↗
PubMed1995

Projections from the lateral mammillary nucleus to the anterodorsal thalamic nucleus in the rat.

There has been an abundance of research on the connections of the mammillary bodies but the projections from the lateral mammillary nucleus to the anterodorsal thalamic nucleus has remained a gray area due to a dearth of material which directly addresses the details of this pathway. This study seeks to further define the nature of this particular nerve connection within the mammillothalmic tract. The technique employed is fluorescent nerve tract tracing using two fluorescent tracers implanted separately into each anterodorsal thalamic nucleus then followed retrogradely to the soma of the neurons in the lateral mammillary nucleus. Fluorescent photomicrography allowed us to document the single and double labeled cells of the lateral mammillary nucleus. The single labeled cells can be categorized into ipsilaterally projecting neurons and contralaterally projecting neurons. About half of all labeled cells were bilaterally projecting double-labeled, a third was ipsilaterally projecting single-labeled and the remainder were contralaterally projecting single labeled-cells. There were no labeled cells traced to the medial mamillary nucleus. The mammillary bodies play an important role in the limbic circuitry and a part of the so-called "Papez Circuit". The pathway by which the mammillary body projects to the other structures of the limbic system and the way it connects the limbic system to other parts of the brain like the tegmentum is not fully understood. This clarification of the connection between the lateral mammilary nucleus and the anterodorsal thalamic nucleus is but one of the contemplated pathways.

Animals↗
PubMed1995

Bifurcating projections from the retinal ganglion cells to the primary visual targets (SC and LGN) in the cat.

Bifurcating projections of retinal ganglion cells to the primary visual targets were studied in the cat using a retrograde fluorescent double-labeling technique with Fluoro-Gold (FG) and Evans Blue (EB) as the tracers. Following injections of FG and EB into the left and right lateral geniculate nuclei (LGN), or into the left and right superior colliculi (SC), or LGN and SC on the same side, 4.56% of the single-labeled cells with one tracer were simultaneously labeled by the other tracer injected contralaterally in bilateral LGN-injection group; 12.18% of the single-labeled cells were further labeled by the other tracer injected contralaterally in bilateral SC injection-group; and 8.95% of the single-labeled cells in the ipsilateral retina, 10.94% of the single-labeled cells in the contralateral retina by the tracer injected into the LGN were labeled by the other tracer injected into the SC on the same side. All three retinal ganglion cell classes by size demonstrated double-labeled cell bodies. In the bilateral LGN- and bilateral SC-injection groups, the double-labeled cells were mainly of the small type (65% and 82.8%, respectively), while in the group of the injections into the LGN and SC on the same side, double-labeled cells were predominantly of the large type (55.45%). These results indicate that single ganglion cells of the retina send bifurcated projections to the bilateral LGN, bilateral SC, or unilateral LGN and SC, via axonal collaterals. These bifurcated axons can be regarded as an important way by which the information of the single ganglion cells can be conducted to the same primary visual targets on both sides, and two different optic centers on the same side of the brain.

Animals↗
PubMed1995

Afferent projections to the cingulate cortex in albino rats: a study with a retrograde labeling method using fluoro-gold.

We studied the neuronal populations that project their axons to the cingulate cortex in albino rats using the retrograde fluorescent dye of 4% Fluoro-Gold injected into the anterior, middle and posterior portions of the cingulate cortex. The result showed that the following ipsilateral structures are sending fibers to these three portions: the prefrontal cortex, frontoparietal motor cortex, indusium griseum, dorsal endopiriform nucleus, lateral part of medial mammillary nucleus, nuclei of diagonal band of Broca, anterior pretectum, anterior part of caudate-putamen, hippocampal formation, anteroventral, anteromedial, lateroposterior, ventroposterior and dorsomedial thalamic nuclei. The anterior portion of the cingulate cortex receives inputs from the following ipsi- and contralateral structures: the accessory olfactory bulbs, anterior olfactory nuclei, middle and posterior portions of the cingulate cortex. The middle cingulate cortex receives fibers only from the ipsilateral dorsal part of the lateral septal nucleus in addition from the ipsi- and contralateral anterior and posterior portions of the cingulate cortex. While the posterior portion of the cingulate cortex receives separate inputs from the following ipsilateral structures: anterodorsal thalamic nucleus, temporal cortex, entorhinal cortex, areas 17 and 18, as well as from the ipsi- and contralateral anterior and middle portions of the cingulate cortex. The present study shows that the cingulate cortex receives various kinds of inputs from the other parts of the brain which are involved in emotion, memory, vision and motion, and also suggests that there are differences in afferent projections among the anterior, middle and posterior portions of the cingulate cortex.

Afferent Pathways↗
PubMed1994

Linkage of kdr-type resistance and the para-homologous sodium channel gene in German cockroaches (Blattella germanica).

Pyrethroids are an important class of insecticides for controlling insect pests, including the German cockroach. Unfortunately, many insects have developed resistance to pyrethroids. One of the most important mechanisms of resistance is kdr (knockdown resistance) which is characterized by neural insensitivity to pyrethroids and DDT. To investigate whether the voltage-dependent sodium channel is involved in kdr-type resistance in the German cockroach, we isolated a 120 bp DNA fragment of the para-homologous sodium channel gene from German cockroaches. Using this fragment as a probe, we identified a restriction fragment length polymorphism (RFLP) of the para-homologous sodium channel gene between susceptible and kdr-type resistant German cockroaches. RFLP analysis of F2 and backcross cockroach populations (total of 331 individuals) showed that all homozygous resistant individuals had a 3.7 kb EcoRI fragment, all homozygous susceptible individuals had a 3.0 kb EcoRI fragment, and all heterozygous individuals had both 3.7 and 3.0 kb fragments. No recombination was detected between the kdr-type resistance locus and the para-homologous sodium channel gene. This suggests that the kdr-type resistance locus and para-homologous sodium channel gene are identical or tightly linked (< 0.2 cM) in German cockroaches. Our results provide strong evidence that modification of para-homologous sodium channels is associated with kdr-type resistance.

Amino Acid Sequence↗
PubMed1994

Speech abnormalities in tardive dyskinesia.

The authors assessed tardive dyskinesia and the structure and physiology of speech apparatus, phonation, and articulation speech abnormalities in 27 chronically ill male psychiatric patients. Tardive dyskinesia was associated with impairment in phonation, intelligibility, and rate of speech production. Patients with and without tardive dyskinesia had similar rates of structural and physiological abnormalities of speech apparatus. The authors conclude that tardive dyskinesia is associated with substantial impairment in speech.

Antipsychotic Agents↗
PubMed1994

[Effect of combined chemotherapy against human intestinal nematode eggs].

The effect of a combination of albendazole and mebendazole was evaluated by stool examination in 7 patients with Ascaris lumbricoides eggs, 7 patients with Trichuris trichiura eggs and 9 patients with hookworm eggs. Albendazole and mebendazole were given at 300 mg and 375 mg, respectively. Both drugs were divided into 3 parts, one part b. id., and given in 1.5 days. The fecal eggs turned negative in all the patients with Ascaris infection in 3 days, while the fecal eggs were negative in all patients with Trichuris or hookworm infection in 5 days. The development rates of the eggs were remarkably lower post-treatment than pre-treatment. It was found that the ovicidal rates in human ascariasis, trichuriasis and ancylostomiasis were 98.8%, 100% and 100%, respectively on the second day following the initiation of treatment. The results showed that the worm-repelling and ovicidal effect of the combined chemotherapy was more evident.

Adolescent↗