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Biomedical subjects

M Kim

Publications and source records attributed to M Kim.

At least 361 records · Page 20Linked to original sources
PubMed1992

Epidemiology of measles immunity in a population of healthcare workers.

OBJECTIVE: To evaluate epidemiologic factors that can be used to predict lack of measles immunity in healthcare workers. DESIGN: During mandatory screening of employees for measles antibody, a questionnaire was used to collect demographic information. SETTING: Inpatient hospital, acute care clinics, and skilled nursing facility of a health maintenance organization. PARTICIPANTS: Employees of all ages and occupations. RESULTS: Measles immunity could not be predicted from history of measles disease and vaccination, gender, or birthplace. Of nonimmune employees, 63.7% were in the 20- to 29-year-old age group and 26.5% were in the 30- to 39-year-old age group. CONCLUSIONS: Age is the most clinically significant predictor of measles antibody, especially in persons born after 1950, who make up a large group susceptible to measles.

Adolescent↗
PubMed1992

Structure of dietary pectin, iron bioavailability and hemoglobin repletion in anemic rats.

The effects of the degree of esterification (DE) and the molecular weight (MW) of pectins on iron bioavailability were investigated in anemic rats. The pectins prepared differed (in DE and MW, respectively) as follows: P-A (73%, 860,000), P-B (75%, 89,000), P-C (22%, 1,260,000) and P-D (24%, 114,000). Rats were fed an iron-deficient diet (8 mg Fe/kg diet) for 14 d. The anemic rats were then fed a ferrous sulfate-supplemented basal diet (47 mg Fe/kg diet) or the basal diet containing one of the pectins (80 g/kg diet) for 10 d. None of the pectins used caused any significant reduction in the bioavailability of ferrous sulfate. Addition of pectin P-B to the diet resulted in significantly greater iron repletion. Compared with control rats fed with ad libitum access or pair-fed, rats fed P-B showed higher (P < 0.05) hemoglobin regeneration efficiency, hematocrit, serum iron concentration, and transferrin saturation, and lower unsaturated iron-binding capacity and total iron-binding capacity. Pectins P-A and P-D also slightly improved the hematological indices compared with P-C and control. The observed effects were dependent on the physicochemical properties of each pectin as determined by its MW and DE.

Anemia, Hypochromic↗
PubMed1992

A novel light-regulated promoter is conserved in cereal and dicot chloroplasts.

The chloroplast psbD-psbC genes encode D2 and cp43, a reaction center protein and chlorophyll-binding antenna protein of photosystem II, respectively. We have previously shown that differential accumulation of light-induced psbD-psbC mRNAs in barley chloroplasts is due to transcription from a blue light-responsive promoter (LRP). It is hypothesized that the light-induced mRNAs help to maintain levels of the D2 polypeptide, which is photodamaged and degraded in illuminated plants. To determine if light-induced accumulation of psbD-psbC mRNAs was a conserved phenomenon in chloroplasts, the expression of psbD-psbC operons from five cereals (barley, wheat, rice, maize, and sorghum) and three dicot (tobacco, spinach, and pea) species was examined. Cereal and dicot psbD-psbC operons differ due to several DNA rearrangements that moved psbK-psbI proximal to psbD-psbC, allowing cotranscription of these genes and production of several unique transcripts in cereals. Despite differences in the structure and expression of the cereal and dicot psbD-psbC operons, the accumulation of light-induced psbD-psbC mRNAs was conserved in all species studied. An unusual feature of the light-induced mRNAs was the occurrence of 5' end microheterogeneity. The multiple 5' termini were mapped to several consecutive nucleotides (8 to 25 bp) within a highly conserved (61%) DNA region that represents the transcription initiation site for the mRNAs in barley and tobacco. The novel LRP differs in sequence from typical plastid promoters that have prokaryotic "-10" and "-35" elements and is centered 570 bp (cereals), 900 bp (tobacco, spinach), or 1100 bp (pea) upstream from the psbD translational start codon. We propose that physiological and gene regulatory demands of the chloroplast act as constraints that preserved the linkage of the LRP with psbD despite DNA inversions involving the psbD upstream region.

Base Sequence↗
PubMed1992

Absorption of polar drugs following caecal instillation in healthy volunteers.

We have investigated colonic drug absorption in man by the caecal instillation of a multi-component solution of atenolol, cimetidine, frusemide, hydrochlorothiazide and salicylic acid. We found that salicylic acid absorption from this solution was delayed but complete whereas the absorption of atenolol, cimetidine, frusemide and hydrochlorothiazide was four- to five-fold lower than expected from oral bioavailability studies.

Adult↗
PubMed1992

The influence of gastrointestinal transit on drug absorption in healthy volunteers.

1. The effect of variability of gastric emptying and oro-caecal transit on the absorption of a multicomponent solution of frusemide, atenolol, hydrochlorthiazide and salicylic acid has been studied in six healthy subjects. Each subject was studied on five separate occasions: three times under basal conditions, once following metoclopramide and once following codeine pretreatment in an attempt to speed and slow transit respectively. 2. Inter-subject variability of gastric emptying, oro-caecal transit and the rate and extent of drug absorption was considerable. 3. The absorption of salicylic acid appeared rate-limited by gastric emptying but the rate and extent of frusemide, atenolol and hydrochlorthiazide absorption were unrelated to measures of gastric emptying or oro-caecal transit. 4. Codeine phosphate caused a two-fold delay in oro-caecal transit but did not influence gastric emptying while metoclopramide had no significant effect on either function. 5. Metoclopramide and codeine had no significant effect on the rate or extent of absorption of any of the study drugs. 6. Within the limits of this experiment, oro-caecal transit time did not appear to be an important determinant of frusemide, atenolol, hydrochlorothiazide or salicylic acid absorption. Other factors must account for the observed variability in drug absorption.

Administration, Oral↗
PubMed1992

Effects of a non-absorbable osmotic load on drug absorption in healthy volunteers.

1. We have studied the effects of a non-absorbable osmotic load on the absorption of a multicomponent solution of frusemide, atenolol, hydrochlorothiazide and salicylic acid in six healthy volunteers. 2. Each subject was studied on up to four separate occasions. The drugs were administered in one of four solutions: a) a mannitol/electrolyte solution, b) a double-strength mannitol/electrolyte solution, c) a glucose/electrolyte solution and d) water. Lactulose or sulphasalazine were added as oro-caecal transit markers. Lactulose was included in the mannitol- and glucose-based solutions, adding a further non-absorbable osmotic load, and sulphasalazine was added to the water, adding little osmotic load. 3. The absorption of atenolol and hydrochlorothiazide was two- to three-times less from all lactulose-containing solutions than from the sulphasalazine-containing solution. The absorption of frusemide and salicylic acid was similar from all four solutions. 4. The largest non-absorbable osmotic load impaired the absorption of atenolol and hydrochlorothiazide most and the incorporation of glucose only partly restored absorption. 5. These results suggest that transmucosal water movement is an important determinant of atenolol and hydrochlorothiazide absorption but is less relevant for the absorption of frusemide and salicylic acid. Furthermore, these data demonstrate a previously unrecognised interaction between a commonly prescribed laxative--lactulose, and atenolol and hydrochlorothiazide.

Adult↗
PubMed1992

Two studies of the non-pharmacological treatment of menstrually-related migraine headaches.

In order to evaluate the effect of non-pharmacological treatment on menstrual and non-menstrual migraine headache (HA), 2 studies have been conducted. In Study 1 which was a retrospective examination of between group reactions to non-drug treatments, 37 self-defined menstrual migraineurs and 62 non-menstrual migraineurs showed comparable overall improvement (reduction in HA activity) after treatment, but menstrual migraineurs maintained larger usage of medication across time than non-menstrual migraineurs. In Study 2 which was a prospective examination of within subject reactions to non-drug treatments, 15 carefully documented menstrual migraineurs again showed comparable levels of overall improvement but also showed that level of menstrual headache activity remained higher across time than non-menstrual migraine HA. Because there were no interactions of time and type of migraine in either study, these results raise some questions about the existence of differential effectiveness of non-pharmacological treatment of menstrual vs non-menstrual migraine.

Adult↗
PubMed1992

Clinical effects of long-term use of neutralized dialysate for continuous ambulatory peritoneal dialysis.

The long-term effects of neutralized dialysate used in continuous ambulatory peritoneal dialysis (CAPD) were evaluated in 8 well-controlled patients. Twelve milliliters of 8.4% sodium bicarbonate was added to Dianeal PD-1 immediately before every administration. The final pH was 6.8 and the concentration of sodium bicarbonate was 6 mmol/l. The final sodium level was 138 mEq/l. This dialysate was used for 5 months. For 2 months before and 3 months after this period, Dianeal PD-2 was used as the dialysate for comparison. Blood bicarbonate levels significantly improved during the use of the neutralized dialysate. Blood sodium, chloride and magnesium levels and the effluent volume significantly increased. Sodium balance improved during the period when neutralized dialysate was used. Total leukocyte counts in the effluent decreased, and leukocyte viability increased. Abdominal distention, abdominal pain during instillation, nausea and headache improved. No side effects, including peritonitis, occurred during the trial of neutralized dialysate. The results suggest that this dialysate was less irritating to the peritoneal membrane than the control dialysate and that the therapeutic effects were satisfactory.

Blood Urea Nitrogen↗
PubMed1992

Intervention program for obese school children.

The purpose of this study was to implement and evaluate a program for obese school children. A pretest-posttest design was utilized. Data was collected related to weight status, skinfold measurements, self-esteem, and nutritional knowledge. A convenience sample of 26 children, in the fourth to sixth grades, completed this 9-week program. The results indicate that self-esteem increased significantly (p less than .001) between the pretest and posttest interval. Weight status and nutritional knowledge showed no improvement. Exercise was difficult to assess on self-report, therefore no conclusions were were drawn in relation to this variable. Future research will be directed toward refining this intervention program.

Child↗
PubMed1992

An improved high-performance liquid chromatographic assay for the determination of pyridinoline in connective tissues.

A high-performance liquid chromatographic (HPLC) method for determination of pyridinoline and its application to connective tissues are described. The chromatographic separation was accomplished by using Inertsil ODS-2 column and a mixture of 0.1 M sodium phosphate and acetonitrile (75:25, v/v) containing sodium dodecyl sulfate (SDS) and ethylenediamine tetraacetic acid (EDTA) as eluent. The chromatogram was developed isocratically and the eluted components were monitored with excitation at 295 nm and emission at 395 nm. The pyridinoline in crude hydrolysate of connective tissues can be determined in 5 min, with as little as 1 pmol of sample. The present method is rapid, simple and can be used for the routine analysis of connective tissues such as cartilage, bone, Achilles tendon and aorta.

Amino Acids↗
PubMed1992

Oncogene and growth factor expression in MEN 2 and related tumors.

Pheochromocytomas occur sporadically or in individuals affected by inherited syndromes including multiple endocrine neoplasia (MEN) type 2A and 2B, neurofibromatosis, and the von Hippel-Lindau syndrome (vHL). Medullary thyroid carcinomas (MTCs) also occur sporadically or as part of MEN 2A, MEN 2B, and familial MTC. Little is known of the molecular genetic background of these tumors. We have shown previously that activation of the N-ras, H-ras, and K-ras oncogenes does not occur in these tumors, but that deletions of the short arm of chromosome 1 are extremely common (> 60%) and may indicate loss of a suppressor gene in the chromosomal region 1p31-36. We have examined the structure and expression of N-myc, c-myc, L-myc, c-mos, nerve growth factor (beta-NGF), and the low affinity nerve growth factor receptor (LNGFR) in a series of pheochromocytomas and MTCs from patients with hereditary and sporadic diseases. Southern analysis, using radiolabeled DNA probes, revealed no evidence of amplification or rearrangement of these genes in any normal or tumor tissues except for loss of heterozygosity at the L-myc locus (1p32) in 9 pheochromocytomas from patients with MEN 2A or MEN 2B, in 5 of 11 non-MEN pheochromocytomas, and in 3 of 24 non-MEN MTCs. Gene expression at the RNA level was examined by Northern analysis or ribonuclease protection assay (RPA) using radiolabeled DNA or cRNA probes. C-myc transcripts were detectable at low levels in all tumors tested.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Gland Neoplasms↗
PubMed1992

Decreased serum bicarbonate as a manifestation of undernutrition secondary to nonorganic failure-to-thrive.

Eight of 101 children (8%) seen serially in consultation in an outpatient failure-to-thrive (FTT) clinic had isolated serum bicarbonate (TCO2) levels between 16 and 20 MEQ/dL (normal 22 to 30 MEQ/dL). None of these eight patients had signs or symptoms of renal disease, and all had nonorganic etiologic factors associated with their malnutrition. At the time of this review, follow-up TCO2 measurements were available for seven of the eight children who had attained normal weight (wt/age greater than fifth percentile on National Center for Health Statistics (NCHS) growth chart). All these children had normal TCO2 levels and no evidence of renal disease on follow-up more than 12 months later. Clinicians treating undernourished children who have low TCO2 measurements and have no signs or symptoms of renal disease and identified nonorganic factors, should consider a trial of therapies directed at nonorganic factors. Clinicians should be aware that a high percentage of undernourished children without other medical disease may have abnormal TCO2 measurements that correct after the institution of adequate caloric intake.

Acidosis, Renal Tubular↗
PubMed1991

Adsorption and elution of bovine gamma-globulin using an affinity membrane containing hydrophobic amino acids as ligands.

A hollow-fibre affinity membrane containing hydrophobic amino acids as ligands was prepared by the radiation-induced grafting of glycidyl methacrylate onto a porous polyethylene hollow fibre and subsequent phenylalanine (Phe) or tryptophan (Trp). The densities of the Phe and Trp ligand of the resulting affinity membrane were 0.4 and 0.4 mol/kg, respectively. The Trp-containing affinity membrane exhibited a higher amount of adsorbed bovine gamma-globulin (BGG) than the Phe-containing membrane. To evaluate the adsorption behaviour of the membrane, the BGG-containing buffer solution was permeated from the inside to the outside of the Trp-containing hollow-fibre affinity membrane through the ligand-immobilized pores. The breakthrough curves as a function of effluent volume coincided irrespective of the flow-rate, i.e. the residence time (55-220 s) of the solution across the membrane (thickness 0.83 mm), as a result of negligible mass transfer resistance. A series of chromatographic procedures, (adsorption-washing-elution) was repeated twice and a satisfactory quantitative elution was attained. The reproducible profile of the flux and the protein concentration assured a quantitative cycle of chromatography using the affinity membrane containing Trp as a ligand.

Animals↗
PubMed1991

Effects of H-2Kb gene on expression of melanoma-associated antigen and lectin-binding sites on BL6 melanoma cells.

An H-2Kb negative BL6 melanoma clone (BL6-8) was transfected with plasmids containing either the class I H-2Kb or class II H-2IAk gene in combination with the neor gene. The effects of the transfected genes on the expression of the melanoma-associated antigen (MAA) recognized by the monoclonal antibodies MM2-9B6 and MM2-3C6 and the cell surface carbohydrates recognized by 15 different lectins were studied. The original H-2Kb- clone or clones transfected with neor or class II H-2IAk genes expressed high levels of MAA and very low levels of soybean agglutinin (SBA), Griffonia simplicifolia I-B4 (GSIB4), and peanut agglutinin (PNA) lectin-binding sites. In contrast, clones that expressed high levels of the transfected H-2Kb gene completely lost the expression of MAA. In addition, these clones were characterized by the appearance of high levels of expression of the sugars specifically reacting with SBA, GSIB4, and PNA lectins. When the original BL6-8 clone was transfected with the H-2Kd gene, 25 clones subsequently isolated had relatively low expression of the transfected H-2Kd gene but high expression of the endogenous H-2Kb gene accompanied by an alteration in expression of the MAA and lectin binding identical with patterns common for H-2Kb+ melanoma cells. These changes were not due to the transfection, plasmid construction, or place of insertion, since similar phenotypic characteristics were found in H-2Kb+ but not H-2Kb- clones isolated from the N-methyl-N'-nitro-N-nitrosoguanidine-treated BL6T2 or parental BL6 melanoma lines. In total, 73 BL6 melanoma clones were investigated and all of the 41 H-2Kb+ clones displayed loss of MAA and appearance of SBA, GSIB4, and PNA-binding sugars. None of the 32 H-2Kb- clones showed these changes. This study indicates that the class I H-2Kb gene product might alter several phenotypic properties of BL6 melanoma cells. The mechanisms of these changes remain unknown. We consider that these effects of the class I H-2Kb gene are indirect, involving interactions with the B-tropic ecotropic retrovirus specific for melanomas of C57BL/6 mice origin.

Animals↗
PubMed1991

Structures of asparagine-linked oligosaccharides from hen egg-yolk antibody (IgY). Occurrence of unusual glucosylated oligo-mannose type oligosaccharides in a mature glycoprotein.

Asparagine-linked oligosaccharides present on hen egg-yolk immunoglobulin, termed IgY, were liberated from the protein by hydrazinolysis. After N-acetylation, the oligosaccharides were labelled with a UV-absorbing compound, p-aminobenzoic acid ethyl ester (ABEE). The ABEE-derivatized oligosaccharides were fractionated by anion exchange, normal phase and reversed phase HPLC, and their structures were determined by a combination of sugar composition analysis, methylation analysis, negative ion FAB-MS, 500 MHz 1H-NMR and sequential exoglycosidase digestions. IgY contained monoglucosylated oligomannose type oligosaccharides with structures of Glc alpha 1-3Man7-9-GlcNAc-GlcNAc, oligomannose type oligosaccharides with the size range of Man5-9GlcNAc-GlcNAc, and biantennary complex type oligosaccharides with core region structure of Man alpha 1-6(+/- GlcNAc beta 1-4)(Man alpha 1-3)Man beta 1-4GlcNAc beta 1-4(+/- Fuc alpha 1-6)GlcNAc. The glucosylated oligosaccharides, Glc1Man8GlcNAc2 and Glc1Man7GlcNAc2, have not previously been reported in mature glycoproteins from any source.

4-Aminobenzoic Acid↗
PubMed1991

Differential polarization imaging. IV. Images in higher Born approximations.

The theory of differential polarization imaging developed previously within the framework of the first Born approximation is extended to higher Born approximations, taking into account interactions among the polarizable groups in the object. Several properties of differential polarization images, originally described using first Born approximation are modified when higher Born approximations are used. In particular, (a) when the polarizable groups are spherically symmetric, the off-diagonal Mueller elements Mij (i not equal to j) in bright field do not vanish in higher Born approximations, as they do in the first Born approximation case. (b) In higher Born approximations, the dark field Mi4 and M4i (i = 1, 2, 3) images do not vanish as in the first Born approximation, due to the anisotropy induced by the interactions among the groups. (c) When the polarizability tensor of each group is symmetric and real, the bright field M14 and M41 images always vanish in the first Born approximation. In higher Born approximations, these terms do not vanish if the groups bear a chiral relationship to each other. Quantitative criteria for the validity of the first Born approximation in differential polarization imaging are explicitly derived for three different types of media: (a) linearly anisotropic, (b) circularly anisotropic, and (c) linearly and circularly anisotropic (medium displaying linear birefringence and circular birefringence). These criteria define the limits of thickness and the degree of anisotropy of optically thin media. Finally, the possibility to perform optical sectioning in differential polarization imaging in the presence and absence of group interactions is discussed.

Biophysical Phenomena↗