Biomedical subjects

M S Kim

Publications and source records attributed to M S Kim.

At least 19 recordsLinked to original sources

PubMed1992

Molecular cloning and characterization of a novel calcium channel from rabbit brain.

The complete amino acid sequence of a novel calcium channel (designated BII) from rabbit brain has been deduced by cloning and sequencing the cDNA. The BII calcium channel is structurally more closely related to the BI calcium channel than to the cardiac and skeletal muscle L-type calcium channels. Blot hybridization analysis of RNA from different tissues and from different regions of the brain shows that the BII calcium channel is distributed predominantly in the brain, being abundant in the cerebral cortex, hippocampus and corpus striatum.

Amino Acid Sequence↗

PubMed1992

Effects on the chicken monocular OKN of unilateral microinjections of GABAA antagonist into the mesencephalic structures responsible for OKN.

The SR 95531, a GABAA antagonist was microinjected into either the pretectum nuclei, (nucleus Superficialis Synencephali nSS) or the nBOR (nucleus Ectomammillaris nEM) of chickens. Monocular optokinetic nystamus (OKN) of each eye was recorded by the search coil technique before and after unilateral intracerebral drug administration. Before injection, monocular horizontal OKN in chickens, as in other lower vertebrates, displays a directional asymmetry: the stimulation in the Temporo-Nasal (T-N) direction is more efficient in evoking OKN than is stimulation in the Naso-Temporal (N-T) direction. Unilateral microinjections of SR 95531 into either the nSS or nEM induce a reversible increase of gain in OKN directed by the contralateral eye for both directions of stimulation. However administration into the nSS increased directional asymmetry by increasing the T-N component slow phase velocity more strongly than the N-T component slow phase velocity. On the other hand, the unilateral administration of the drug into the nEM suppressed the directional OKN asymmetry by increasing the N-T component slow phase velocity more strongly than the T-N component slow phase velocity. These results indicate that the drug suppresses GABAergic inhibition at the mesencephalic level. Moreover the nSS seems especially involved in monocular OKN in response to a T-N stimulation, while the nEM seems more involved in the OKN response to N-T stimulation. The increase in gain of OKN directed by the ipsilateral eye to microinjected nuclei could account for the strong interactions existing between these mesencephalic structures responsible for horizontal OKN.

Animals↗

PubMed1992

Pharmacological study of the chicken's monocular optokinetic nystagmus: involvement of the ON retinal channel evidenced by the glutamatergic separation of ON and OFF pathways.

The chicken's monocular optokinetic nystagmus (OKN), recorded by the magnetic search coil technique, displays a directional asymmetry, the temporal-nasal (T-N) stimulation being more efficient than the nasal-temporal (N-T) one to evoke the reflex. The intravitreal administration of APB, a glutamate agonist which selectively blocks the ON retinal channel strongly reduced the eye monocular OKN; it also induced spontaneous eye movements in the T-N direction. The intravitreal injection of PDA another glutamate analog, which reduces the OFF channel, while increasing the activity of the ON channel, induced a large increase in OKN velocity gain, especially for a N-T stimulation at the lowest drum speeds. These results indicate the main involvement of the ON retinal channel in the OKN genesis and the inhibitory effect of the OFF channel upon this oculomotor reflex.

Aminobutyrates↗

PubMed1992

Pharmacological study of the chicken's monocular optokinetic nystagmus: effects of GABAergic agonist and antagonists.

When injected into the chicken open eye, the GABA-agonist THIP and the GABA-antagonists bicuculline and picrotoxin induced spontaneous eye movements in nasal-temporal (N-T) and in temporal-nasal (T-N) direction, respectively. These spontaneous movements were scarcely modulated by optokinetic stimulation, irrespective of the direction of stimulation. It is suggested that they are due to the suppression of directional selectivity of retinal ganglion cells. When injected into the closed eye, GABAergic drugs did not produce spontaneous nystagmus. THIP provoked a reduction of the N-T component, without modifying the T-N one, while GABA antagonists induced a significant increase in OKN performance, especially for the N-T direction of stimulation. In these conditions, picrotoxin also provoked an increase in the duration of both components of optokinetic after nystagmus, indicating a direct effect of the drug upon the velocity-storage system.

Animals↗

PubMed1992

Low p53 level in immortal, non-tumorigenic oral keratinocytes harboring HPV-16 DNA.

The p53 protein level was determined in normal oral keratinocytes and two non-tumorigenic, immortal oral keratinocyte lines harboring human papillomavirus-16 (HPV-16)DNA. The p53 mRNA level in the immortal cells was higher than the normal counterpart, but the p53 protein level was notably lower in the immortalised cells. The half-life of p53 protein in the normal and immortal cells was < 1 h, and the p53 cDNA sequence of these cells showed no mutation. The immortal cells transcribed a high amount of E6/E7 mRNA encoded by HPV-16, but normal cells did not. These observations suggest that the immortal keratinocytes may translate normal level of wild-type p53 protein, and the low p53 level in these cells may be due to the enhanced degradation of the protein by HPV-16 E6 protein.

Blotting, Northern↗

PubMed1992

Secondary intraocular lens implantation in aphakia.

We retrospectively studied secondary intraocular lens (IOL) implantation in 165 aphakic patients (162 eyes) from May 1983 to August 1989. Seventy-five eyes (46.3%) had secondary IOL implantation; these included seven cases of trans-sulcus scleral fixation of the posterior chamber lens. The remaining 87 eyes could not have secondary IOL implantation because of the ocular conditions. The most common reason for secondary implantation was to relieve the discomfort caused by spectacles or contact lenses (56.2%). An anterior chamber lens was used in 43 eyes (57.3%) and a posterior chamber lens in 32 eyes (42.7%). Final postoperative visual acuity of 20/40 or better was achieved in 92.0% of the eyes with posterior chamber lenses, in 71.4% of the eyes with anterior chamber lenses, and in 57.1% of the eyes with scleral-fixated posterior chamber lenses. Endothelial cell loss was greater in the eyes with anterior chamber lenses than in the eyes with posterior chamber lenses. Of the cases that could be followed, 83.3% showed endothelial cell loss of less than 30% at six months postoperatively. Postoperative complications such as cystoid macular edema, persistent fibrinous membrane formation, and neovascular glaucoma occurred in only ten (13.3%) of the 75 eyes that had secondary implantation. These complications occurred more frequently in eyes that had anterior chamber lenses with anterior vitrectomy. There were no noticeable complications in the eyes that had trans-sulcus scleral fixation of posterior chamber lenses. Updrawn pupil, prolapsed vitreous, and peripheral anterior synechia were common conditions preventing secondary IOL implantation.

Adult↗

PubMed1992

Outcome of renal transplantation in children less than two years of age.

Twenty-two renal transplants were performed in 21 children less than two years of age at Children's Hospital. Fourteen were from living related donors and eight were from cadaveric donors. The five year patient and graft survivals of these recipients were compared to all other pediatric recipients between two and 18 years of age who received renal transplants over the same time period. Five year graft survival for recipients less than two years of age was 86% following living-related donor transplantation and 38% following cadaver donor transplantation. Older pediatric recipients aged between two and 18 years had a five year graft survival of 73% following living-related donor renal transplantation, which was similar to that for recipients less than two years of age. Although older cadaveric recipients had a comparable five year graft survival to younger recipients, at 42%, the patterns of graft loss were different. Graft failures in young recipients occurred within the first seven months post-transplant, whereas the older recipient's grafts failed more gradually. Actuarial five-year patient survival in recipients less than two years of age was 86% following living-related donor renal transplantation and 70% following cadaver-donor renal transplantation. Recipients less than two years of age had a poorer patient survival than older recipients following both living-related donor renal transplantation (P = 0.06) and cadaver-donor renal transplantation (P less than 0.05). These findings suggest that the graft survival of living-related donor renal transplantation in recipients less than two years of age is better than that of cadaver-donor renal transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1992

Sequential combined tumorigenic effect of HPV-16 and chemical carcinogens.

We immortalized oral keratinocytes by transfection with recombinant human papillomavirus type 16 (HPV-16) DNA and established two cell lines, human oral keratinocytes-16A (HOK-16A) and -16B (HOK-16B). These cell lines were morphologically different from the normal counterpart, contained HPV-16 DNA as integrated form and expressed numerous viral genes. However, these cells proliferated only in culture medium containing low calcium (0.15 mM) and are not tumorigenic in nude mice. To test the hypothesis that tumors can be developed by sequential combined effect of human papillomavirus and chemical carcinogens in the oral cavity, these immortalized cell lines were chemically transformed by exposure to either benzo[a]pyrene or methanesulfonic acid ethyl ester. Such transformants proliferated in medium containing physiological calcium levels (1.5 mM) and demonstrated enhanced growth potential in nude mice, whereas primary human oral keratinocytes treated with these chemical carcinogens failed to show any evidence of transformation. Chemically transformed cells contained integrated, intact HPV-16 sequences and transcribed significantly higher amount of HPV-16 E6/E7 messages and transforming growth factor-alpha (TGF-alpha) compared with the immortalized oral keratinocytes. Like the HPV-immortalized cell lines, the chemically transformed oral keratinocytes contained lower levels of newly synthesized, wild-type p53 proteins compared to normal cells, and expressed wild-type c-Ha-ras. These results indicate that this in vitro system is useful for investigating the mechanisms of multistep oral carcinogenesis.

Base Sequence↗

PubMed1992

Dipstick immunoassay to detect enterohemorrhagic Escherichia coli O157:H7 in retail ground beef.

A sensitive and easy-to-perform dipstick immunoassay to detect Escherichia coli O157:H7 in retail ground beef was developed by using a sandwich-type assay (with a polyclonal antibody to E. coli O157 as the capture antibody and a monoclonal antibody to E. coli O157:H7 as the detection antibody) on a hydrophobic polyvinylidine difluoride-based membrane. E. coli O157:H7 in ground beef could be detected within 16 h, including incubation for 12 h in enrichment broth and the immunoassay, which takes 4 h. Pure culture cell suspensions of 10(5) or 10(6) E. coli O157:H7 organisms per ml produced intense color reactions in the immunoassay, whereas faint but detectable reactions occurred with 10(3) CFU/ml. The sensitivity of the combined enrichment-immunoassay procedure as determined by using ground beef inoculated with E. coli O157:H7 was 0.1 to 1.3 cells per g, with a false-positive rate of 2.0%. A survey of retail ground beef using this procedure revealed that 1 of 76 samples was contaminated by E. coli O157:H7.

Animals↗

PubMed1992

Congenital nephrotic syndrome: preemptive bilateral nephrectomy and dialysis before renal transplantation.

Congenital nephrotic syndrome (CNS) is a rare and uniformly fatal disease if it is not treated. Although renal transplantation has been a successful treatment, there remains a high mortality rate during the first year of life before transplantation. From 1979 to 1987, four patients with CNS, all of whom died before they could undergo renal transplantation were treated. On the basis of this clinical experience, early elective bilateral nephrectomy and dialysis for infants with CNS were initiated to improve overall outcome. From 1987 to 1989, this protocol has been used on four consecutive patients with CNS. In these patients, bilateral nephrectomy was performed only after patients suffered a serious CNS-related complication that occurred between 4 and 6 months of age. Despite nephrectomy and the need for chronic dialysis, all patients grew at normal or accelerated rates. By 16 months of age, all patients underwent successful renal transplantation.

Female↗

PubMed1992

The effect of hyperglycemia on lipid peroxidation in the global cerebral ischemia of the rat.

To investigate the influence of hyperglycemia on ischemic brain damage, we measured brain ATP, lactate and malondialdehyde (MDA) levels in global cerebral ischemic models of Wistar rats. We induced global cerebral ischemia by the 4-vessel occlusion method. After 30 or 60 min of occlusion, and after 30 min of reperfusion, we measured brain ATP, lactate and MDA levels. During the ischemic period, brain ATP levels decreased to 30-70% of sham groups both in normoglycemic and hyperglycemic groups. But during the reperfusion period, the recovery rate of ATP levels was significantly lower in the hyperglycemic than in the normoglycemic groups (p less than 0.05). After 60 min of global ischemia, brain lactate increased much more in the hyperglycemic than in the normoglycemic group, and, during reperfusion, was washed out slowly in the hyperglycemic group. The MDA level, a parameter of lipid peroxidation, increased more in the hyperglycemic group than in the normoglycemic group during reperfusion periods (p less than 0.05). We conclude that hyperglycemia increases lactate accumulation, delays the recovery of energy metabolism, and enhances the lipid peroxidation in the transient global ischemia of rat brain. These findings may suggest the harmfulness of hyperglycemia in clinical cerebral ischemia.

3,4-Methylenedioxyamphetamine↗

PubMed1991

Primary structure and functional expression from complementary DNA of a brain calcium channel.

The primary structure of a voltage-dependent calcium channel from rabbit brain has been deduced by cloning and sequencing the complementary DNA. Calcium channel activity expressed from the cDNA is dramatically increased by coexpression of the alpha 2 and beta subunits, known to be associated with the dihydropyridine receptor. This channel is a high voltage-activated calcium channel that is insensitive both to nifedipine and to omega-conotoxin. We suggest that it is expressed predominantly in cerebellar Purkinje cells and granule cells.

Amino Acid Sequence↗

PubMed1991

Long-term patient survival in a pediatric renal transplantation program.

In adult renal transplant recipients, reports have shown continuing mortality beyond 5 years after transplantation with the majority of deaths due to myocardial infarctions, malignancies, and liver failure. Little information is available on the long-term survival of children following renal transplantation. Children with end-stage renal disease have fewer systemic complications than adults and should have better long-term survival. Furthermore, analysis of mortality in the pediatric population should be more informative of the risks of renal transplantation, separate from underlying pretransplant diseases and the inherent complications of aging. We analyzed, therefore, the long-term mortality of renal transplant recipients in a single pediatric center. A total of 299 renal transplants were performed in 251 patients from 1971 through 1990. No patient was excluded from the evaluation. Over all, actuarial survival was 91% at 1 year, 83% at 10 years, and 81% at 15 years. Patient's age at transplantation, donor source, and number of previous allografts were not correlated with patient survival. There were 35 deaths with 51% attributable to infections. The majority of deaths (71%) occurred within the first 6 months after renal transplantation during the period of greatest immunosuppression. Mortality within the first 12 months following renal transplantation was higher during the period 1971-1974 when compared to subsequent years. These data demonstrate that in a pediatric renal transplant center, long-term patient survival is excellent. Most deaths occur within the first 6 months following renal transplantation and are caused by infections. As expected, long-term survival in children is better than reports in adult renal transplant recipients and may more accurately reflect true renal-transplant-related mortality.

Adolescent↗

PubMed1990

Electrical stimulation of the medial amygdala facilitates gastric acid secretion in conscious rats.

One hundred and twenty-seven conscious rats prepared with chronic gastric fistula were studied to investigate the effect of stimulation of the medial amygdala on gastric acid secretion. Gastric acid output was significantly increased by electrical stimulation of the medial amygdala in normal rats and the increase in acid secretion was completely abolished by vagotomy. Vagotomized rats, with or without amygdaloid stimulation, showed comparable levels of gastric acid output which were significantly lower than in controls. These results indicate that the amygdala effect on gastric acid secretion is carried via the vagus nerve. Subcutaneous injections of high doses of histamine increased gastric acid secretion which was further increased by amygdaloid stimulation. Plasma levels of gastrin were not significantly changed by stimulation of the medial amygdala with or without vagotomy. From the above results, we concluded that in conscious rats the medial amygdala plays a significant role in stimulating gastric acid secretion, the vagus nerve is involved in this process, but it is not mediated by release of either histamine or gastrin.

Amygdala↗

PubMed1990

Abolition of monocular optokinetic nystagmus directional asymmetry after unilateral visual deprivation in adult vertebrates: involvement of the GABAergic mechanism.

In lower vertebrates such as frogs and chickens, monocular optokinetic nystagmus (OKN) displays directional asymmetry, temporal-nasal (T-N) stimulation being more efficient in evoking this visuomotor reflex than N-T stimulation. The N-T component of monocular OKN is significantly weaker in chickens, while it is almost absent in frogs. Coil recordings showed that in adult frogs and chickens, prolonged monocular visual deprivation by unilateral eyelid suture provoked the appearance of the N-T component in frogs as well as its significant and progressive increase in both species. The administration of THIP, a GABAA agonist, abolished reversibly the increase of the N-T component in both species. This fact suggests that the GABAergic system could be involved in determining this plasticity process observed in adult lower vertebrates.

Animals↗

PubMed1990

Directional asymmetry of the horizontal monocular head and eye optokinetic nystagmus: effects of picrotoxin.

Frog monocular eye and head optokinetic nystagmus (OKN) were studied by coil recordings after intravitreal administration of picrotoxin into the closed eye. Before injection, the frog displayed an OKN only for stimulations in the temporo-nasal (T-N) direction. The injection of picrotoxin provoked the appearance of a N-T component of the head and eye OKN: the slow phase velocity gain and the resetting fast phase frequency were strongly and significantly increased. Thus, picrotoxin abolished the directional asymmetry of head and eye OKN, indicating the involvement of GABAergic mechanisms in the inhibition of the N-T component of the monocular eye and head OKN. Picrotoxin administration had an additional effect on the monocular head OKN only, the performances (measured by the velocity gain and the frequency of resetting fast phases) were markedly increased for both directions of stimulation, suggesting an effect of the drug upon the motor output of head movements.

Animals↗

PubMed1990

Effects on the surrounding tissues and morphological changes of components after implantation of PMMA and heparin surface modified PMMA intraocular lens in rabbit eyes.

The aim of this study was to evaluate the cellular response and morphological changes of cells on the intraocular lens(IOL) implanted over a course of time and to identify the basic mechanism of IOL adaptation to tissue reaction in the implanted eye by comparing polymethylmethacrylate (PMMA) IOL with heparin surface modified PMMA IOL. ECCE using Healon was done in 36 eyes of 36 rabbits. A heparin surface modified IOL was implanted in 18 eyes (Group I), while PMMA IOL was implanted into another 18 eyes (Group II). Corneal thickness and endothelial cell density were measured for 3 months. Postoperatively, the eyes were enucleated, and a cytopathologic examination of the cells on the surface of the IOL and their ultrastructural changes were observed with light and scanning microscope at various points of time. The findings of this present study suggested that heparin surface modified PMMA IOL reduced the degree of endothelial cell damage, postoperative tissue reaction, and pigment deposits on the surface of the IOL. These were statistically significant. The most important cell was considered to be the macrophage for the adaptation of IOL in the eye which gradually changed into a fibroblast-like cell, giant cell and finally disappeared after forming an acellular membrane on the IOL.

Animals↗

PubMed1990

[Health status of elderly persons in Korea].

This Study was done to design and test an instrument to measure the health status of the elderly including physical, psychological and social dimensions. Data collection was done from July 18 to August 17, 1990. Subjects were 412 older persons in Korea. A convenience sample was used but the place of residence was stratified into large, medium and small city and rural areas. Participants located in Sudaemun-Gu, Mapo-Gu, and Kangnam-Gu, Seoul were interviewed by brained nursing students, and those in Chungju, Jonju, Chuncheon, and Jinju by professors of nursing colleges. Rural residents were interviewed by community health practitioners working in Kungsang-Buk-Do, Kyngsang-Nam-Do, Jonla Buk-Do, and Kyung Ki-Do. The tool developed for this study was a structured questionnaire based on previous literature and then tested for reliability and validity. This tool contained 20 physical health status items, 17 mental-emotional health status items and 38 social health status items. Physical health status items clustered in to six factors such as personal hygiene, activity, home management, digestive, sexual, sensory, and climatization functions. Mental-emotional health status items clustered into two factors, mental health and emotional health. Social health status items clustered into seven factors, grandparent, parent, spouse, friend, kinships, group member and religious role functions. Data analysis included percentage, average, S.D., t-test and ANOVA. The results of the analysis were as follows: 1. The tool measuring the health status of the elderly and developed for this research had a relatively high reliability indicated by a Cronbach = 0.97793. 2. Average score of the subjects physical health status was 4,054 in a 5 point likert scale, mental-emotional health status was 3.803, social health status was 2.939 and the total average was 3.521. The social status of the subjects was the lowest and the next was mental-emotional health status; physical health status was the highest. 3. Educational background, perceived health status, the amount of pocket money were related to physical and mental-emotional health status and family structure was related mental-emotional physical and social health status. Occupation was related to physical and mental-emotional status. Area of residence was related to mental-emotional and social status. Source of living in the expenses was related to physical and mental-emotional health status marital status to mental-emotional and social health status, and the number living in the home physical health status and religion to social health status.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗