Biomedical subjects

M H Kim

Publications and source records attributed to M H Kim.

At least 217 records · Page 12Linked to original sources

PubMed1996

Chemical composition of gallbladder sludge in patients after marrow transplantation.

OBJECTIVES: Gallbladder sludge develops in approximately 70% of patients after bone marrow transplantation (BMT). Sludge often develops in these patients without known predisposing factors, such as fasting or narcotic use. In this study, we examined the chemical composition of sludge in BMT patients. METHODS: Gallbladder content samples from 15 patients were obtained at autopsy. Presence or absence of sludge was determined by examination of gallbladder contents. Sludge samples were examined with direct and polarizing microscopy and assayed for cholesterol, bilirubin, and calcium content and for the presence of a calcium-binding protein. RESULTS: On microscopic examination, cholesterol monohydrate crystals were almost completely absent. Calcium bilirubinate crystals were present in large amounts in all samples. Calcium-ceftriaxone crystals were found in two patients who had received ceftriaxone. A large proportion of the sludge (84.6%) was found to be "unmeasurable residue." Of this part, 5-30% was accounted for by a calcium-binding protein. CONCLUSIONS: We conclude that gallbladder sludge in patients after marrow transplantation consists primarily of "unmeasurable residue," calcium bilirubinate, and a calcium-binding protein. Cholesterol crystals are almost absent. We conclude that formation of gallbladder sludge in these patients could serve as a model for studying the pathogenesis of pigment gallstones.

Autopsy↗

PubMed1996

Frequency of phasic wave contraction is variable during long-term sphincter of Oddi manometry.

OBJECTIVES: The sphincter of Oddi (SO) manometry via the transpapillary route is performed usually for a period of several minutes. To investigate whether there is a considerable variation in the manometric measurements of SO over a longer period of time, we have performed long-term manometry of SO via the transpapillary (n = 5) as well as the percutaneous (n = 7) routes. METHODS: Transpapillary manometry of SO was carried out by a conventional low-compliant continuously perfused technique. The location of the manometric catheter was maintained at the same level by observing the video monitor. SO manometry and the duodenal migrating motor complex (MMC) was simultaneously measured with a specially designed catheter via the percutaneous route. RESULTS: The mean recording time was 41 min (range 11-72 min). The frequency of phasic contractions of SO varied from 0 to 12/min. Throughout the entire recording period, high-frequency contractions (over 8/min) were noted 14.9% of the time. In the cases of percutaneous transductal SO manometry, the periods of high-frequency contractions coincided with phase III of duodenal MMC. The interval between the first high-frequency contractions and the second was 47 min. The mean duration of high-frequency contractions was 6 min and 42 s. There was no significant change in the amplitude, basal pressure, and contraction sequence among the various periods of frequencies. CONCLUSIONS: Long-term continuous recording of SO manometry via the transpapillary and percutaneous routes showed that the contraction frequency of SO was not constant and tachyoddia appeared periodically. In the interpretation of tachyoddia, it is necessary to consider the period of phase III of the duodenal MMC.

Bile Ducts, Intrahepatic↗

PubMed1996

Patient satisfaction with a levonorgestrel-releasing contraceptive implant. Reasons for and patterns of removal.

OBJECTIVE: To investigate the experience of the users of a levonorgestrel-releasing contraceptive implant (Nor-plant) and reasons for early removal. STUDY DESIGN: Two hundred fifty-one women who had Norplant placed through the Ohio State University Department of Obstetrics and Gynecology were sent a questionnaire that included general demographic questions and questions regarding preplacement education; reasons for choosing Norplant; problems experienced due to Norplant; reasons for removal, if applicable; and overall satisfaction. RESULTS: One hundred eleven questionnaires (44%) were completed and analyzed. Twenty-four (21.6%) of patients had Norplant removed, 32 (28.8%) planned on early removal, and 55 (49.5%) desired continued use. Ninety-eight percent of women who planned continued use of Norplant had received reading material as part of their preplacement counseling and 95% felt adequately counseled. This is significantly higher than women who had Norplant removed or planned on early removal. Convenience, problems with other contraceptive methods and effectiveness were the most important reasons why patients chose Norplant. Menstrual changes were the most common side effect, experienced by 80% of all women in the study. Weight gain, headache, mood changes, mastalgia and acne were also frequently reported. Women who had Norplant removed were significantly more likely to have experienced dizziness when compared to women desiring continued use. Women planning early removal were also more likely to have experienced dizziness in addition to acne, headache, hair loss and other side effects. Menstrual irregularities, followed by mood changes and headaches, were the most important side effects associated with early Norplant removal. Overall, 68% of users were at least somewhat satisfied with Norplant. CONCLUSION: Norplant contraception was a satisfactory form of birth control for the majority of patients in the study despite the frequent occurrence of side effects. Reading material regarding benefits and side effects of Norplant is an important aspect of patient counseling and may improve long-term use of Norplant.

Adolescent↗

PubMed1995

The Gag polypeptides of the Drosophila 1731 retrotransposon are associated to virus-like particles and to nuclei.

1731 is a Drosophila melanogaster retrotransposon whose nucleotide sequence shows a proviral architecture with two long terminal repeats (LTRs) framing two internal Open Reading Frames (ORFs). The pol ORF2 of this mobile genetic element was demonstrated to code for an active Reverse Transcriptase (RT) and the ORF1 is expected to code for the structural Gag proteins of the virus-like particles (VLP). Using specific anti-Gag antibodies, we have characterized the 1731 Gag polypeptides expressed either in vitro or in Kc Drosophila melanogaster cultured cells. Together with the 1731 RT, the largest, likely post-translationaly-modified Gag polypeptides are gathered into cytoplasmic virus-like particles. Moreover and consistent with the nuclear localization signal present in the Gag sequence, we observed that a short 1731 Gag polypeptide is associated to the cell nuclei.

Amino Acid Sequence↗

PubMed1995

Oct-1 protein promotes functional transcription complex assembly on the mouse mammary tumor virus promoter.

The ubiquitous transcription factor Oct-1 stimulates basal transcription from the mouse mammary tumor virus (MMTV) promoter by binding to octamer-related sequences present in the proviral long terminal repeat. The mechanism of transcriptional activation by Oct-1 was investigated using in vitro transcription assays with a HeLa cell nuclear extract depleted of endogenous Oct-1. Oct-1-mediated transcriptional activation could be reconstituted by addition of bacterially expressed recombinant Oct-1 protein. The stimulatory effect of Oct-1 was observed only when the protein was present during formation of transcription preinitiation complexes and not when added to fully assembled complexes. Furthermore, assembled MMTV preinitiation complexes were resistant to inhibition by a competitor oligonucleotide containing MMTV octamer-related elements that could eliminate Oct-1-mediated stimulation when present during the assembly process. The time course of transcription complex assembly revealed that Oct-1 increases the number of templates on which functional transcription complexes form. Finally, experiments designed to exploit the sensitivity of discrete steps in transcription complex assembly to the anionic detergent Sarkosyl demonstrated that Oct-1 must be present during formation of an early intermediate in the assembly process.

Animals↗

PubMed1995

Identification of efficient pentapeptide substrates for the tyrosine kinase pp60c-src.

The development of inhibitors of protein tyrosine kinases (PTKs) is a promising approach to obtaining new therapeutic agents for a variety of diseases, particularly cancer. However, the discovery of peptide-based inhibitors has been hindered by the lack of small peptide substrate sequences (i.e. five residues or less) with which a variety of inhibitor designs could be readily evaluated by replacing the Tyr with natural and unnatural amino acids. These prototypical small peptide inhibitors could then form the basis for designing analogous conformationally constrained, peptide-mimetic or non-peptide inhibitors with improved therapeutic potential. In this study we have identified the best known small peptide substrate for the PTK pp60c-src, which is the parent of the src family of nonreceptor PTKs. This pentapeptide substrate, Ac-Ile-Tyr-Gly-Glu-Phe-NH2, has a Km of 368 microM and Vmax of 1.02 mumol/min/mg when tested utilizing the assay methodology of Budde et al. (Anal. Biochem. 1992, 200, 347-351) after a series of modifications were made to more closely simulate the conditions inside a typical mammalian cell. This substrate was designed from information obtained by Songyang et al. (Nature 1995, 373, 536-539) with a 2.5 billion member combinatorial library of peptide substrates for pp60c-src. A second pentapeptide substrate, Ac-Glu-Asp-Ala-Ile-Tyr-NH2, with a weaker binding affinity (Km = 880 microM) but improved Vmax (1.86 mumol/min/mg), was also identified. This peptide was designed from the pp60c-src autophosphorylation sequence and information obtained by Songyang et al. (Ibid.) and Till et al. (J. Biol. Chem. 1994, 269, 7423-7428) with combinatorial libraries of peptide substrates. These new substrates provide sufficient binding affinities and rates of phosphorylation to be utilized for evaluating the relative effectiveness of various reversible and mechanism-based irreversible inhibitor designs for pp60c-src while appended to easily prepared small peptides.

Adenosine Diphosphate↗

PubMed1995

Immunocytochemical localization of sGnRH and cGnRH-II in the brain of goldfish, Carassius auratus.

The immunocytochemical distribution of salmon gonadotropin-releasing hormone (sGnRH) and chicken GnRH-II (cGnRH-II) neurons in the brain of goldfish was examined using respective antisera. Salmon GnRH-immunoreactive (ir) cell bodies were localized in the area between the olfactory nerve and the olfactory bulb (the terminal nerve ganglion), the ventral telencephalon, the preoptic area, and the hypothalamus. Chicken GnRH-II-ir cell bodies were observed in the same areas as were those of sGnRH, although the number of cell bodies were fewer than those of sGnRH. In addition, chicken GnRH-II-ir cell bodies were also observed in the midbrain tegmentum where no sGnRH-ir cell bodies were found. Both sGnRH-ir and cGnRH-II-ir fibers were distributed not only in the hypothalamus and the pituitary gland but also in various brain areas from the olfactory bulb to the spinal cord. The wide distribution of GnRH-ir fibers suggests that in the goldfish, sGnRH and cGnRH-II not only regulate gonadotropin release from the pituitary gland but also function as neuromodulators in various brain regions.

Animals↗

PubMed1995

Structure and composition of primary intrahepatic stones in Korean patients.

We have analyzed the chemical composition of primary intrahepatic stones from 72 Korean patients. Two types of concretions have been identified: brown pigment (calcium bilirubinate) stones and black-colored mixed stones. Brown pigment stones were found in 68% of all cases and the remainder (32%) consisted of mixed stones. Intrahepatic mixed stones had mean cholesterol and bilirubin contents of 46.6% and 25.9%, respectively, whereas calcium bilirubinate stones had mean cholesterol and bilirubin contents of 14.1% and 43.6%, respectively. Intrahepatic mixed stones had a smooth black-colored surface and on cross section, exhibited a distinct outer shell surrounding an inner yellow, cholesterol-rich body. The finding of intrahepatic mixed stones with high cholesterol content suggests that primary hepatolithiasis may result from at least two different conditions or disorders and points to different approaches to their treatment.

Adult↗

PubMed1995

Chemical synthesis and cloning of human beta-endorphin gene in Escherichia coli.

Total synthesis of human beta-endorphin gene has been designed for the expression in bacterial system. Eight individual oligonucleotides corresponding to the beta-endorphin gene were chemically synthesized and joined through the enzyme-catalyzed reaction. The final yield of the 111-nucleotide-long synthetic beta-endorphin gene construct was about 10% of the total oligonucleotide used. The synthetic human beta-endorphin gene was cloned into the bacterium Escherichia coli, using pUC8 vector and shown to have the correct nucleotide sequences as designed.

Amino Acid Sequence↗

PubMed1995

Stimulation of basal transcription from the mouse mammary tumor virus promoter by Oct proteins.

The steroid hormone-inducible promoter of mouse mammary tumor virus (MMTV) contains three overlapping sequences related to the consensus octamer motif ATGCAAAT. Basal promoter activity in the absence of hormone induction from a template in which all three octamer elements were mutated was decreased by two-to threefold in in vitro transcription assays. Oct-1 protein purified from HeLa cell nuclear extracts, as well as recombinant Oct-1 expressed in bacteria, recognized MMTV octamer-related sequences, as shown by DNase I footprinting. Furthermore, rabbit polyclonal antiserum directed against recombinant Oct-1 completely inhibited the formation of specific complexes between MMTV octamer-related sequences and proteins present in nuclear extracts of HeLa cells, indicating that Oct-1 is the major protein in HeLa nuclear extracts that recognizes octamer-related sequences in the MMTV promoter. In addition, depletion of Oct-1 from the nuclear extract by using Oct-1-specific antiserum or a sequence-specific DNA affinity resin decreased in vitro transcription from the wild-type MMTV promoter to a level identical to that obtained from a promoter in which all three octamer-related sequences were mutated. Addition of purified HeLa Oct-1 or recombinant Oct-1 to the depleted extract selectively increased transcription from the wild-type relative to the mutated promoter, demonstrating that Oct-1 transcription factor stimulates basal transcription from the MMTV promoter. A similar effect was observed when purified recombinant Oct-2 was added to the Oct-1-depleted extract, suggesting that Oct-2 may play an important role in MMTV transcription in B cells.

Base Sequence↗

PubMed1995

Evidence for a streptococcal superantigen-driven process in acute guttate psoriasis.

Recent studies have suggested that T cells play a critical role in the pathogenesis of psoriasis. Guttate psoriasis is a well-defined form of psoriasis frequently associated with streptococcal throat infection. This study tested the hypothesis that T cells in acute guttate psoriasis skin lesions may be activated by streptococcal superantigens. Peripheral blood as well as lesional and perilesional skin biopsies were analyzed for T cell receptor V beta repertoire using monoclonal antibodies against 10 different V beta families. Skin biopsies from all patients with acute guttate psoriasis, but not skin biopsies from patients with acute atopic dermatitis or inflammatory skin lesions induced in normal subjects with sodium lauryl sulfate, demonstrated selective accumulation of V beta 2+ T cells (P < 0.05). The expansion of V beta 2+ T cells occurred in both the CD4+ and the CD8+ T cell subsets. Sequence analysis of T cell receptor beta chain genes of V beta 2-expressing T cells from skin biopsies of patients with guttate psoriasis showed extensive junctional region diversity that is more compatible with a superantigen rather than a conventional (nominal) antigen-driven T cell response. All streptococcal isolates from patients with guttate psoriasis secreted streptococcal pyrogenic exotoxin C, a superantigen known to stimulate marked V beta 2+ T cell expansion. These data support the concept that acute guttate psoriasis is associated with superantigenic stimulation of T cells triggered by streptococcal superantigen(s).

Acute Disease↗

PubMed1995

A conserved enhancer of the human and murine Hoxa-7 gene specifies the anterior boundary of expression during embryonal development.

The murine homeobox-containing gene Hoxa-7 is expressed in restricted patterns during embryogenesis and plays an important role in the control of region-specific differentiation. Previous studies have shown that separate elements specify lineage restriction and expression boundaries of Hoxa-7. In particular 3.6 kb of 5' flanking sequences were sufficient to establish an anterior boundary of Hoxa-7 gene expression. To identify the minimal regulatory element specifying the anterior boundary of expression, transgenic mice were generated carrying chimeric constructs with deletions of 5' flanking sequences fused to a thymidine kinase minimal promoter/E. coli lacZ reporter construct. By deletion analysis, a 470 bp long control element (AX 470) located 1.6 kb upstream of the transcription start site was identified that directed expression of the beta-galactosidase protein in a pattern reflecting the anterior boundary of expression of the endogenous Hoxa-7 gene. This element was active in either orientation and conferred region-specific expression to unrelated promoters, thereby behaving like an enhancer element. In contrast, transgenic mice carrying further 5' and 3' deletions of the 470 bp long element did not exhibit an anterior boundary of Hoxa-7 expression. Based on these results the minimal control element (AX 470) specifying the anterior boundary of Hox expression was designated as Hoxa-7 enhancer. Furthermore, 3 kb of the human HOXA7 upstream region were sequenced and compared to its mouse homologue in order to identify conserved regions. Sequence comparison revealed motifs that were strongly conserved between both species. The human homologue of the mouse Hoxa-7 enhancer was 70% identical at the nucleotide level and was also capable of directing an anterior boundary in transgenic mice. Using transgenic lines a detailed analysis of the Hoxa-7 enhancer-directed expression during embryogenesis was performed. lacZ expression was first detected in the allantois at day 7.5 p.c. and in mesoderm and ectoderm at day 8.5 of gestation. Between gestational ages E8.5 to E12.5 beta-gal expression was observed in the somites, spinal cord, spinal ganglia and paraxial mesoderm as well as in mesenchymal layers of the kidney. A distinct anterior limit of expression was noted in transgenic lines at level C4 (neural tube) and C5 (spinal ganglia). Our deletion experiments defined a minimal enhancer element specifying the anterior boundary of Hox gene expression in early and late phases of development. Further studies aim at characterizing the trans-acting factors that mediate the spatial and temporal expression of Hox genes in the developing embryo.

Animals↗

PubMed1995

Coexistence of myasthenia gravis and pemphigus foliaceus.

Myasthenia gravis and pemphigus are both considered to have an autoimmune basis. Although immunological and clinical studies have been performed on large numbers of patients with myasthenia gravis, the coexistence of myasthenia gravis and pemphigus foliaceus has rarely been described. We recently have the opportunity to study a 33-year-old female patient having both of these autoimmune diseases confirmed by various diagnostic methods. This rare coexistence of myasthenia gravis and pemphigus foliaceus has not been previously documented in Korea.

Adult↗

PubMed1995

Primary intrahepatic stones.

Hepatolithiasis, or primary intrahepatic stones, is prevalent in the Far East. This clinical syndrome has been previously referred to in the West as Oriental cholangiohepatitis. The majority of primary intrahepatic stones are calcium bilirubinate stones, but intrahepatic stones with high cholesterol purity have recently been recognized. Primary intrahepatic stones are formed de novo within the liver and can be distinguished from extrahepatic stones on the basis of a unique pathogenetic etiology, chemical composition, and clinical course. Patients with hepatolithiasis are often plagued by a progressive illness punctuated by multiple intrahepatic strictures, recurrent cholangitis, liver abscesses, and hepatic destruction. Advances in interventional radiological techniques, cholangioscopy, and novel surgical innovations have led to significant changes in the way these patients are now managed.

Bile Ducts, Intrahepatic↗

PubMed1995

RNA quadruplex containing G and A.

The CD study of r(GGAGGAA) has indicated that it forms a higher order structure upon either increase of the strand concentration or addition of K+. Gel electrophoresis showed that a high molecular weight species is formed in the presence of K+. The NMR study revealed a nearly 1:1 equilibrium of two kinds of higher order structures at the strand concentration of 2.1 mM and 100 mM Na+. This equilibrium shifted drastically upon addition of K+, and only one structure remained at 40 mM K+. It is suggested that the structure formed by r(GGAGGAA) in the presence of K+ is a new type of RNA quadruplex, where an A-quartet stabilized by mutual hydrogen bonding among the four adenine bases is sandwiched by conventional G-quartets.

Adenine↗

PubMed1994

Allelic divergence in the human insulin gene provides evidence for intragenic recombination events in the non-coding regions: evidence for existence of new alleles.

Intragenic polymorphism of the human insulin gene (INS) was investigated in Korean subjects. The 1.9 kb INS sequence, including the 5' to 3' flanking regions, was amplified using the polymerase chain reaction (PCR), and analyzed by direct sequencing. All nucleotide sequences in the coding regions were the same as INS sequences previously reported, and four nucleotides, at positions +216, +1045, +1367, and +1380 in the non-coding regions, were found to be polymorphic. In addition to the previously identified polymorphic alleles alpha 1 (A-C-C-C) and beta 1 (T-G-T-A), new nucleotide arrangements were also identified and designated alpha 4 (A-C-C-A), alpha 5 (A-G-C-C), alpha 6 (A-C-T-C), and beta 2 (T-C-C-C). It was concluded that the new alleles may originate by intragenic recombination within INS during chromosomal crossing-over between the alpha 1 and beta 1 alleles. The allele alpha 1 was the predominant form in our sample; the new variant alleles, as well as allele beta 1, appeared to be much less frequent in INSs genes of the Korean subjects studied. Furthermore, the new alleles were detected only in heterozygous form. These results suggest that intragenic recombination can account for allelic divergence in INS.

Alleles↗

PubMed1994

Gonadotropin-releasing hormones of terminal nerve origin are not essential to ovarian development and ovulation in goldfish.

The involvement of gonadotropin-releasing hormones (GnRHs) from the terminal nerve (TN) in ovarian development and ovulation was examined by olfactory tract section (OTX) in goldfish. After OTX, brain contents of salmon GnRH (sGnRH) and chicken GnRH-II (cGnRH-II) were measured by specific radioimmunoassays. Olfactory tracts of sexually maturing females were sectioned prior to the spawning season and were kept under natural conditions. Two months later, brain sGnRH contents markedly decreased in all brain areas (telencephalon, hypothalamus, optic tectum-thalamus, cerebellum, medulla oblongata) except in the olfactory bulbs, whereas cGnRH-II contents did not obviously change. Despite the large decreases in brain sGnRH contents, OTX and sham-operated female fish underwent vitellogenesis. Sexually mature OTX females could be stimulated to ovulate by increased water temperatures during spawning season. Brain sGnRH contents of these OTX fish also markedly decreased with no changes in cGnRH-II. It appears that sGnRH of TN origin, which comprises most of the brain sGnRH in the goldfish, is not a prerequisite for basal gonadotropin secretion and ovarian development, and is not likely to be related to the preovulatory gonadotropin surge which stimulates ovulation in goldfish.

Animals↗

PubMed1994

The microinjected Drosophila melanogaster 1731 retrotransposon is activated after the midblastula stage of the amphibian Pleurodeles waltl development.

The entire 1731 retrotransposon of Drosophila melanogaster, tagged with the E. coli lac Z gene inserted in its gag sequence, was injected into oocytes and fertilized eggs of the urodele amphibian Pleurodeles waltl. Expression of the reporter gene indicated that the 1731 promoter (its 5'LTR) is active in the embryos and not in the oocytes. It appeared that this element is regulated as amphibian genes are at the beginning of the development, i.e. that expression was detected after the mid blastula stage and maintained up to four or five days after injection. Another construction associating the modified 1731 promoter with the CAT gene is also expressed in Pleurodeles embryos during the same period of development. This indicated that the 1731 promoter issued from a Drosophila species is activated as promoting sequences of amphibian zygotic genes are, suggesting that in the case of horizontal transfer, 1731 can be expressed into vertebrate organisms.

Animals↗