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Biomedical subjects

S Kim

Publications and source records attributed to S Kim.

At least 1,243 records · Page 69Linked to original sources
PubMed1989

Phenotypic heterogeneity of lymphoma of the skin.

We studied surface markers present in 56 cases of lymphoma of the skin by immunohistochemical staining, using the ABC (avidin-biotin-peroxidase complex) and PAP (peroxidase-antiperoxidase complex) methods. Of these cases, 49 were T-cell lymphoma and 7 were B-cell lymphoma. Ten of the 49 cases of T-cell lymphoma were adult T-cell leukemia/lymphoma (ATL). Twenty-five of 31 cases of T-cell lymphoma except ATL analyzed by the ABC method showed a helper/inducer phenotype (Leu2a-,Leu3a+), two cases showed a suppressor/cytotoxic phenotype (Leu2a+, Leu3a-), one case showed Leu2a+Leu3a+, one case showed an inducer phenotype (Leu2a-, Leu3a+, Leu9+), and one case showed OKT11+, Leu2a-, Leu3a-, Leu1-, Leu9+, CD25+, Leu10+, CD30+. One CD8+ lymphoma was Pagetoid reticulosis, and a CD4+, CD8+ lymphoma was lymphomatoid papulosis with erythematous plaque. Cutaneous T-cell lymphoma (CTCL), previously described by Edelson et al., is defined as a helper T-cell lymphoma with marked affinity for the skin. In our study, 5 cases of T-cell lymphoma of the skin were not CTCL as described by Edelson et al. These results show that T-cell lymphoma of the skin is heterogeneous in nature. In other words, CTCL is one type but represents a major proportion of T-cell lymphomas of the skin.

Humans↗
PubMed1989

Cytochrome c methylation.

In this review, protein methylation is outlined in general terms, highlighting the major amino acids that are methylated and some of the proteins in which they are found. The majority of the review examines the methylation of cytochrome c at Lys-77 of lower eukaryotes as a possible model for methylation studies. Early work involving the purification and characterization of the methyltransferase responsible for this methylation indicated cytochrome c was methylated posttranslationally, yet prior to import into the mitochondria. Methylation in vitro occurred only at the in vivo methylation site and only on cytochrome c. Later studies using in vitro translated apocytochrome c revealed that methylated, as compared with unmethylated, apocytochrome c was imported preferentially into yeast, but not rat liver, mitochondria. Efforts to discover the reasons for this preference have shown that methylation of apocytochrome c dramatically lowers its isoelectric point (against a predicted increase) and decrease its Stokes radius. A possible mechanism for these differences involving the disruption of hydrogen bonds is presented here with space-filling models. Finally, the in vivo significance of this modification is also discussed.

Animals↗
PubMed1989

Modification of glycosylation of renin in sodium-depleted and captopril-treated rats.

Concanavalin A (con A) chromatography of rat plasma revealed the presence of three differently glycosylated forms of renin, including the con A unbound form (renin C), the loosely bound form (renin A), and the tightly bound form (renin B). Rat renal cortical slices in vitro secreted all these forms. They had a different half-life in the plasma after ligation of both renal artery and vein (half-life of 21 +/- 1, 14 +/- 3, and 35 +/- 4 min for renin A, B, and C, respectively). Thus differently glycosylated forms of renin are released from the kidney into the blood circulation and disappear, with a different half-life. Rats were sodium-depleted and captopril-treated (40-60 mg.kg-1.day-1) for 2 wk, and the effects of these treatments on relative proportions of renin A, B, and C were investigated. These treatments elevated plasma renin concentration approximately 60-fold (from 24 +/- 3 to 1,406 +/- 128 ng angiotensin I.h-1.ml-1; P less than 0.01), in association with an increase in the relative percent of renin C in the plasma from 22 +/- 2 to 39 +/- 3% (P less than 0.01). Moreover, the relative proportion of renin C released from the renal cortical slices was significantly higher in the treated than in the control rats (42 +/- 9 vs. 16 +/- 3% of secreted renin, respectively; P less than 0.02). These results show that the predominant release of renin C, with the longest half-life (35 min) in the plasma, contributes to the increased plasma renin concentration in sodium-depleted and captopril-treated rats.

Animals↗
PubMed1989

Central effect of endothelin on blood pressure in conscious rats.

This study was conducted to investigate the effect of intracerebroventricular administration of endothelin (EDT), a novel potent vasoconstricting peptide, on blood pressure in conscious rats. The lateral cerebral ventricle of male Wistar rats was cannulated, and the femoral artery was also cannulated to measure the mean arterial blood pressure (MABP) and heart rate (HR). EDT dissolved in 10 microliters of artificial cerebrospinal fluid (ACSF) (8.25-66 pmol icv) provoked a dose-dependent increase in MABP. EDT also increased HR, although the effect of 66 pmol was variable. Intracerebroventricular ACSF did not provoke any effects on MABP and HR. Intracerebroventricular EDT also provoked contralateral rotational behavior. Pretreatment with 2 mg/kg iv phenoxybenzamine significantly suppressed the 16.5 pmol icv EDT-induced increase in MABP. Moreover, 16.5 pmol icv EDT markedly increased plasma epinephrine and norepinephrine concentration. These results indicate that EDT has a central pressor action, and the action might be mediated, at least in part, by catecholamine release to the periphery. EDT might play a role in the central control of blood pressure, although the physiological implications have not yet been determined.

Animals↗
PubMed1989

Circulating levels of calcitonin gene-related peptide in patients with medullary thyroid carcinoma.

Calcitonin gene-related peptide, originally found in rat medullary thyroid carcinoma cells, was measured by radioimmunoassay in plasma samples with added aprotinin from 17 normal volunteers and 21 patients with medullary thyroid carcinoma. The concentrations were below 75 pmol/l in all 17 normal subjects with a mean of 33 +/- 19 pmol/l plasma. In the patients, the plasma calcitonin gene-related peptide concentrations ranged from below 5 pmol/l to 236 pmol/l, although the mean (36 +/- 48 pmol/l) was not significantly different from the mean normal level. Increase in the plasma calcitonin gene-related peptide level was observed in 2 of 5 patients in response to infusion of 4.3 mg/kg of calcium for 10 minutes and in 3 of 5 patients in response to infusion of 4 micrograms/kg of tetragastrin for 5 minutes. These observations suggest that measurement of calcitonin gene-related peptide level may be helpful in determination of diseases in which the level of calcitonin is of less diagnostic value.

Adolescent↗
PubMed1989

An outcome evaluation of refusal skills program as a drug abuse prevention strategy.

In recent years successful strategies developed in the antismoking campaign became the basis for widely publicized and federally endorsed antidrug "Just Say No" programs. Similarly, many refusal skills programs have been introduced as a new strategy in adolescent drug abuse prevention. However, none of these programs have been evaluated. While employing a typical refusal skills program entitled "WHOA! A Great Way To Say NO," the effectiveness of the program was examined. Through this outcome evaluation, it has been learned that the program was not able to impact on the "high-risk" attitudinal syndromes that are closely related to student drug involvement. Unexpectedly, a significantly larger proportion of students in the program felt it was more difficult to say "No" at the time of the posttest than during the time of the pretest. This seems to suggest that the program participants became more attentive to the issues surrounding saying "No" or, perhaps, were more sensitized to the whole issue involving saying "No," thereby making it more difficult for them to say "No" during the posttest period.

Assertiveness↗
PubMed1989

The impact of the "I'm Special" Program on student substance abuse and other related student problem behavior.

There has been a proliferation of school-based substance abuse prevention programs geared toward reducing or delaying the onset of student use of illegal drugs. But the field has shown a general absence of evaluation dealing with the behavior consequences of these practices. This article fills this gap by using the case of the "I'm Special" Program (ISP) targeted for fourth grade students. Using a quasi-experimental design, a comparison is made between the substance using and other problem behavior of students who have been exposed to the ISP and those who have not during their later school years in grades 5 through 12. At the aggregate level, the proportions of current substance users and the incidence of their related problem behavior were significantly lower among the ISP graduates than those who have not been exposed to the program. In particular, there were consistently lower proportions of current substance users among the ISP recipients than the non-recipients in grades 5-7. However, the impact of the ISP seems to diminish significantly in and around ninth grade. During the senior high level, the pattern revealed is almost random. And, in some drug categories, it has been speculated that the ISP students were trying to "catch up" with what they may have missed out on during earlier grade levels.

Adolescent↗
PubMed1989

[Theoretical models of causative factors in depression: a review of the literature for nursing].

This literature review was undertaken to explore theoretical models of depression for their potential usefulness in nursing research and practice. Depression has been accounted for by numerous theories or models of causation: 11 theories selected from psychology, medicine and psychoanalysis and supported by empirical or experimental research were reviewed. These theories identify a variety of precipitating and predisposing factors that may affect the individual's depression. Aggression-turned-inward theory, object loss theory, ego functioning theory, personality organization theory, behavioral theory, learned helplessness theory, cognitive theory, genetic factors, and biological theories conceptualize predisposing factors. Only life stressors theory identifies precipitating factors. Each of these theories contributes to an understanding of depression, but many of them use overlapping and interrelated factors. It is also evident from recent research that there are multiple causes for depression involving an interactive effect among predisposing and precipitating factors that are both biological and psychological in origin. That is, a single theory is not useful, but perhaps a unified theory could be developed that would be helpful to nursing. This review points to the need for continuing development and testing of theories that would integrate the multiple conceptualizations of depression.

Depression↗
PubMed1989

Low density lipoprotein and apoprotein B induce increases in inositol trisphosphate and cytosolic free Ca2+ via pertussis toxin-sensitive GTP-binding protein in vascular smooth muscle cells.

Low density lipoprotein (LDL), a major cholesterol-carrying lipoprotein in the plasma, binds to its receptor through apoprotein B (Apo-B). The addition of LDL and Apo-B induced rapid (5 s), but transient increase in the inositol 1,4,5-trisphosphate (Ins-1,4,5-P3) level with K0.5 values of 1.1 and 0.07 microgram/ml, accompanied by increases of cytosolic free Ca2+ concentration [( Ca2+]i), in vascular smooth muscle cells (VSMC). The increases by LDL and Apo-B were both reduced by pretreatment of the VSMC with pertussis toxin. The early change in Ins-1,4,5-P3 involving a GTP-binding protein may function as an initial signal for the action of LDL in VSMC.

Animals↗
PubMed1989

Microcirculation of the dental pulp and its autonomic control.

Pulpal vessels are innervated with sympathetic adrenergic vasoconstrictor fibers. Electrical stimulation of the cervical sympathetic nerve causes pulpal arteriolar constriction and a reduction of arteriolar and venular flow rate (in mm3/s) in rat incisor pulps and a decrease in pulpal blood flow (in ml/min/100 g) in canine pulps of cats and dogs. The alpha-antagonist phenoxybenzamine and the alpha-1 antagonist prazosin attenuated the decrease in pulpal blood flow (PBF) caused by sympathetic stimulation. Reflex excitation of the sympathetic nerve system by hemorrhage caused pulpal vasoconstriction and a reduction of PBF. Induction of hemorrhagic hypotension in dogs subjected to cervical sympathectomy and adrenalectomy caused less pronounced pulpal vasoconstriction and flow reduction than in normal dogs. Pulpal vessels are also equipped with alpha-1, alpha-2 and beta-adrenergic receptors. Activation of alpha-1 and alpha-2 receptors by intraarterial injection of phenylephrine and clonidine caused a reduction in PBF in dogs and decreases in arteriolar and venular diameters and volumetric flow in rats. These responses were blocked by the alpha-1 and alpha-2 antagonists. Activation of beta-2 receptors by i.a. injection of isoproterenol caused a paradoxical reduction of PBF in dogs. In rats isoproterenol caused a transient increase in the flow rate followed by a reduction, and arteriolar dilation was accompanied by venular constriction. These flow responses to isoproterenol were blocked by the beta-2 antagonist propranolol. Results of microcirculatory studies in dogs and rats indicate that pulpal hemodynamics are regulated significantly by the sympathetic adrenergic system.

Animals↗
PubMed1988

Purification and molecular identification of two protein methylases I from calf brain. Myelin basic protein- and histone-specific enzyme.

Two different molecular species of protein methylases I (S-adenosylmethionine:protein-arginine N-methyltransferase, EC 2.1.1.23), one specific for myelin basic protein (MBP) and the other for histone, have been purified from calf brain to near homogeneity, as discerned by nondenaturing polyacrylamide gel electrophoresis. Although both methylases share some common properties, such as utilization of S-adenosyl-L-methionine as the methyl donor and methylation of protein-bound arginine residues, they are distinctly different from each other in molecular weight and in catalytic, as well as the immunological, properties. The MBP-specific protein methylase I (approximately 500 kDa) methylates MBP preferentially (Km = 2 X 10(-7) M) and histone to a much lesser extent (Km = 1 X 10(-4) M), while the histone-specific methylase I (approximately 275 kDa) methylates histone only. Both methylases exhibit two major subunit bands on sodium dodecyl sulfate-polyacrylamide gel electrophoresis: 100 and 72 kDa for the MBP-specific and 110 and 75 kDa for the histone-specific. At 0.5 mM p-chloromercuribenzoate, about 50% of the MBP-specific enzyme remained as active, while most of the histone-specific enzyme activity was lost. In 2 mM guanidine HCl, approximately 90% of the former enzyme activity remained while nearly complete inactivation of the latter enzyme was observed. The enzymes also exhibited quite different inactivation profiles toward high temperature (45-65 degrees C); MBP-enzyme was stable up to 50 degrees C and was rapidly inactivated at higher temperatures with an inflection point at about 57 degrees C. However, under the identical conditions, histone-enzyme was inactivated progressively and linearly in the same temperature range. Finally, Western immunoblot analysis of polyclonal antibodies directed against either enzyme exhibited no cross-reactivity with the other.

Animals↗
PubMed1988

Effect of enzymatic methylation of yeast iso-1-cytochrome c on its isoelectric point.

Yeast iso-1- unmethylated and methylated apocytochrome c were synthesized in vitro by translating yeast cytochrome c mRNA, and by subsequently methylating the protein product. Unmethylated and methylated iso-1-holocytochrome c were extracted from Saccharomyces cerevisiae. By employing a column isoelectrofocusing technique, the pI values of these proteins were determined. The pI values of unmethylated and methylated apocytochrome c were found to be 9.60 and 8.70, respectively, with a difference of 0.90 pI unit. On the other hand, the pI values of unmethylated and methylated holocytochrome c were 9.72 and 9.68, respectively, with a difference of 0.04 unit. Therefore, although the pI values of both apo- and holocytochrome c decreased by methylation, methylation of apocytochrome c had a more profound effect on the pI of the protein. The result also indicated that conjugation of heme to apocytochrome c increased its pI value, resulting in the more "compact" and basic structure of the protein. The observed magnitude of the pI change subsequent to the methylation of apocytochrome c (decrease of 0.90 unit) seemed to be contradictory to the predicted increase in the value, since the positive charge is fixed on the quaternary amino group of trimethyllysine and there is no proton to titrate. Trimethylation of epsilon-NH2 group of Res-72 lysine of apocytochrome c could disrupt any possible hydrogen bond formed by the nitrogen atom of Res-72 lysine residues, as visualized by a space-filling model. The model and observed shift in the "effective charge" of the protein strongly suggest that conformational change in the apoprotein takes place upon methylation. This presumably altered conformation along with the decrease in pI caused by methylation may play a role in enhancement of apocytochrome c import into mitochondria.

Chromatography, Gel↗