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J Kim

Publications and source records attributed to J Kim.

At least 1,135 records · Page 63Linked to original sources
PubMed1987

Effect of amino acid at the beta 6 position on surface hydrophobicity, stability, solubility, and the kinetics of polymerization of hemoglobin. Comparisons among Hb A (Glu beta 6), Hb C (Lys beta 6), Hb Machida (Gln beta 6), and Hb S (Val beta 6).

Surface hydrophobicity, stability, solubility, and kinetics of polymerization were studied using hemoglobins with four different amino acids at the beta 6 position: Hb A (Glu beta 6), Hb C (Lys beta 6), Hb Machida (Gln beta 6), and Hb S (Val beta 6). The surface hydrophobicity increased in the order of Hb C, Hb A, Hb Machida, and Hb S, coinciding with the hydrophobicity of the amino acid at the beta 6 position. Solubility of the oxy-form of these hemoglobins decreased in relation to increases in their surface hydrophobicity, suggesting that the solubility is controlled by the strength of hydrophobicity of the amino acid at the beta 6 position. The solubility of the oxy-form of these hemoglobins is always higher than that of the deoxy-form. There is a similar linear relationship between the solubility and surface hydrophobicity among deoxyhemoglobins A, C, and Machida. However, the solubility of deoxy-Hb S deviated significantly from the expected value, indicating that the extremely low solubility of deoxy-Hb S is not directly related to the hydrophobicity of the beta 6 valine. Kinetic studies on the polymerization of deoxy-Hb Machida revealed a distinct delay time prior to polymerization. This confirms our previous hypothesis that beta 6 valine is not responsible for the delay time prior to gelation. The kinetics of the polymerization of 1:1 mixtures of sickle and non-sickle hemoglobins were similar to those of pure Hb S, suggesting that only one of the two beta 6 valines is involved in an intermolecular contact. In mixtures of equal amounts of Hb S and Hb A, Hb C, or Hb Machida, half of the asymmetrical AS, SC, and S-Machida hybrid hemoglobins behaved like Hb S during nucleation, while the other half behaved like the non-sickle hemoglobin.

Drug Stability↗
PubMed1987

Many ventral root afferent fibers in the cat are third branches of dorsal root ganglion cells.

The arrangement of the ventral root afferent fibers was investigated in anesthetized and paralyzed cats. Single unit activity was recorded from a fascicle of the distal stump of the cut S1 dorsal root. Activity was elicited by stimulating the distal stump of the cut S1 ventral root. Attempts were then made to collide this activity with that elicited by stimulation of the S1 spinal nerve. Single unit activity elicited by ventral root stimulation was recorded from a total of 33 axons. In 17 of these, the activity collided with that elicited by peripheral stimulation. These results indicate that more than half the sampled population of ventral root afferent fibers are branches of dorsal root ganglion cells that have at least 3 processes: one in the dorsal root, one in the ventral root and one in a peripheral nerve. In 10 of these units, the conduction velocity of each of 3 processes was determined using the collision technique. The conduction velocities differed in the processes of a given ganglion cell, with conduction in the ventral root process generally being the slowest. The change in conduction velocity along the length of the ventral root was examined by comparing latency differences for the unit activity elicited by ventral root stimulation at different sites in the same root separated by known distances. The conduction velocity was found not to be uniform along the course of the ventral root. In many cases, the conduction velocity slowed down as the fiber approached the spinal cord. We conclude from the present study that many ventral root afferent fibers are the third branches of dorsal root ganglion cells that also have processes in the dorsal root and in a peripheral nerve. The sizes of each of these 3 processes of the dorsal root ganglion cell may differ; the ventral root process tends to be the smallest and is usually unmyelinated. Furthermore, many of the ventral root afferent fibers may taper as they approach the spinal cord.

Action Potentials↗
PubMed1987

Effect of the beta 73 amino acid on the hydrophobicity, solubility, and the kinetics of polymerization of deoxyhemoglobin S.

The role of Asp-beta 73 on the surface hydrophobicity and solubility of hemoglobin was studied using Hb A, Hb S, Hb C Harlem (alpha 2 beta 2Val-6,Asn-73), and Hb Korle Bu (alpha 2 beta 2Asn-73). The surface hydrophobicity of the oxy form of these hemoglobins increased in the order of Hb A, Hb Korle Bu, Hb S, and Hb C Harlem, coinciding with the change in solubility. The same is not true for deoxyhemoglobins. The solubilities of deoxy-Hb S and deoxy-Hb C Harlem were much lower than that expected from their surface hydrophobicity. Although the hydrophobicity of deoxy-Hb C Harlem is greater than that of deoxy-Hb S, the solubility of deoxy-Hb S is only one-third that of deoxy-Hb C Harlem. This deviation must be caused by the substitution of Asn for Asp at the beta 73 position and its inhibitory effect on hydrogen bonding in Hb S polymers. The kinetics of the polymerization of 1:1 mixtures of the deoxy form of S-C Harlem, A-C Harlem, Korle Bu-S, and Korle Bu-C Harlem were studied in comparison with that of deoxy-Hb S and deoxy-Hb C Harlem alone. All of these binary mixtures polymerized with a distinct delay time prior to polymerization. Based on the results of kinetic studies, the probability factors for nucleation of S-C Harlem, A-S, A-C Harlem, S-Korle Bu, and Korle Bu-C Harlem hybrid hemoglobins were calculated as 0.65, 0.5, 0.5, 0.15, and 0.17, respectively, in comparison with that of Hb S (1.0). The probability factor for Hb C Harlem alone was 0.3. These data suggest that the Asp-beta 73 is directly involved in nucleation during Hb S polymerization and that the beta 73 is always trans to the active Val-beta 6 in the formation of nuclei.

Aspartic Acid↗
PubMed1987

Difference in capacities for virion-to-virion fusion of young and aged HVJ (Sendai virus): a model of membrane fusion.

Young and aged HVJ virions differ structurally and morphologically due to changes that occur during aging in vitro or in ovo. Young virions soon after their budding off are rod-shaped, rigid and relatively uniform in size, whereas virions that have aged in vitro after their formation are round, nonrigid and variable in size. These changes during aging seem to be due to the variation of M protein, a "skeletal" protein that is associated with both the envelope membrane proteins and nucleocapsid strands in the virions. The capacities for virion-to-virion fusion of young and aged virions were compared to clarify the relation between the membrane fusion and membrane-associating skeletal proteins. On treatment with polyethylene glycol (PEG), aged virions readily fused, forming large virion vesicles, but young virions were resistant to fusion. Further, aged virions fused even on incubation at 37 degrees C without the fusogen. Thus the capacity for virion-to-virion fusion evidently increases during aging of virions. This result suggests that skeletal proteins associating with the biological membrane are important for preventing membrane fusion, and that virion-to-virion fusion is a good model system for use in studies on the mechanism of membrane fusion.

Animals↗
PubMed1987

The improved efficient method for introducing macromolecules into cells using HVJ (Sendai virus) liposomes with gangliosides.

Macromolecules such as DNA and RNA can be entrapped within liposomes associated with gangliosides by reverse-phase evaporation. When these liposomes are incubated with HVJ2 (Sendai virus), they deliver their contents into cultured cells efficiently. More than 95% cells of a Ltk- cell line (thymidine kinase-deficient cells) transiently expressed thymidine kinase activity by thymidine kinase gene transfer using HVJ liposomes with gangliosides. Stable transformants could be obtained efficiently from various cell lines by use of HVJ liposomes containing the neoR gene. The neo+ transformants were obtained at frequencies of about 0.2-1.0, 0.06-0.25, and 0.06-0.1% in monolayers of L, CHO-Kl, and HeLa-S3 cells, respectively. Moreover, in Ehrlich ascites tumor cells which grow in suspension, the frequency was more than 0.01%. On introduction of plasmid pTK4 into Ltk- cells, about 0.5-1.0% TK+ transformants were obtained. Cosmid DNA containing the neoR gene (about 45 kbp) was also introduced into L cells by this method and neo+ transformants were obtained at a frequency of 0.1%. When rat liver mRNA was introduced into L cells by HVJ liposomes with gangliosides, immunoprecipitation studies showed that the L cells secreted rat albumin and some other proteins into the cultured medium. Moreover, using erythrocyte membrane vesicles containing IgM that had been incubated with HVJ empty liposomes with gangliosides, the IgM could be introduced into all the L cells.

DNA↗
PubMed1987

Characterization of the Stimulation of Ethylene Production by Galactose in Tomato (Lycopersicon esculentum Mill.) Fruit.

We have characterized the stimulation of ethylene production by galactose in tomatoes (Lycopersicon esculentum Mill.). The effect of concentration was studied by infiltrating 0, 4, 40, 100, 200, 400, or 800 micrograms galactose for each gram of fresh fruit weight into mature green ;Rutgers' fruit. Both 400 and 800 micrograms per gram fresh weight consistently stimulated a transient increase in ethylene approximately 25 hours after infiltration; the lower concentrations did not. Carbon dioxide evolution of fruit infiltrated with 400 to 800 micrograms per gram fresh weight was greater than that of lower concentrations. The ripening mutants, rin and nor, also showed the transient increase in ethylene and elevated CO(2) evolution by 400 micrograms per gram fresh weight galactose. 1-Aminocyclopropane-1-carboxylic acid (ACC) content and ACC-synthase activity increased concurrently with ethylene production. However, galactose did not stimulate ACC-synthase activity in vitro. The infiltrated galactose in pericarp tissue was rapidly metabolized, decreasing to endogenous levels within 50 hours. Infiltrated galacturonic acid, dulcitol, and mannose stimulated transient increases in ethylene production similar to that of galactose. The following sugars produced no response: sucrose, fructose, glucose, rhamnose, arabinose, xylose, raffinose, lactose, and sorbitol.

Journal Article↗
PubMed1987

Recombinant tissue plasminogen activator in patients with pulmonary embolism: correlation of fibrinolytic specificity and efficacy.

Blood samples from 24 patients who received recombinant human tissue-type plasminogen activator (rt-PA) for angiographically documented acute pulmonary embolism were examined to identify and quantify fibrinolysis. Before and after the intravenous administration of 50 mg rt-PA over a 2 hr period, levels of total fibrinogen, fibrin(ogen) degradation products (FDP), and cross-linked fibrin degradation products (XDP) were measured in each patient. Elevated levels of XDP were found in all patients before treatment (mean 2.0 micrograms/ml, normal less than 0.2 microgram/ml), and these increased 12-fold with treatment. Fibrinogen levels fell 30% and FDP levels increased 24-fold for the entire group of patients. Over this 2 hr period, 10 of 24 patients (responders) demonstrated 25% or greater improvement in the extent of pulmonary artery thrombus as quantified by Urokinase Pulmonary Embolism Trial score, and these patients were found to have a significantly lower XDP/FDP ratio after rt-PA (p less than .04) than those patients who failed to respond. These data suggest that the intravenous administration of pharmacologic doses of rt-PA in patients with pulmonary embolism produces both fibrinolysis and fibrinogenolysis, successful thrombolysis in these patients is associated with a preponderance of fibrinogenolysis over fibrinolysis, the XDP/FDP ratio is a useful indicator of fibrinolytic specificity, and in patients with acute pulmonary embolism the endogenous fibrinolytic pathways are activated, albeit ineffectively, as indicated by the increased circulating XDP levels seen in all 24 patients before the administration of rt-PA.

Adult↗
PubMed1987

[Primary malignant fibrous histiocytoma of the breast, report of a case].

Although malignant fibrous histiocytoma (MFH) is the most common soft tissue sarcoma of adult, it rarely arises in the breast tissue. Only seven cases have been previously reported in Japan. One case of the MFH of the mammary gland is presented in this paper. A 39 year old woman, who had received no radiation, was referred to our hospital due to a painful right breast lump. Excisional biopsy revealed yellowish white soft tumor with an obscured margin. Histological, tumor was composed of spindle shaped cells of a storiform pattern, which was diagnosed as MFH of the breast. Radical mastectomy (Br + Mj + Ax) was added to this patient. The tumor invaded to the fat tissue without metastasis to the axillary lymph nodes. We performed the post-operative adjuvant chemotherapy of Adriamycin. She made an uneventful recovery and is now free of disease eleven months postoperatively.

Adult↗
PubMed1986

Fusion of phospholipid vesicles induced by alpha-lactalbumin at acidic pH.

Alpha-Lactalbumin (alpha-LA), lysozyme, and ribonuclease are found to induce fusion of phosphatidylserine/phosphatidylethanolamine vesicles at low pH. The fusogenic behavior and the binding to phospholipid vesicles of one of these proteins, alpha-LA, are studied at a wide range of conditions. The initial rate of fusion in the presence of alpha-LA increases with increasing acidity below pH 6, and the extent of alpha-LA binding to the vesicles is also found to increase with decreasing pH. Once bound to the vesicles in acidic media, the neutralization to pH 7 fails to dislodge the alpha-LA from the vesicles, and this irreversible binding also increases with decreasing pH. A segment of alpha-LA is found to be resistant to the proteolytic digestion when initially incubated with the vesicles at low pH. The amino acid composition of this fragment was determined, and from this the sequence of alpha-LA fragment, which appears to be inserted into the bilayer, is deduced. Hydrophobic labeling with dansyl chloride renders support that this segment indeed penetrates into the hydrophobic interior of bilayer. Since both the N-terminal and the C-terminal of this vesicle-bound protein are accessible to the externally added proteolytic enzymes, it is concluded that a loop of the polypeptide segment goes into the bilayer. These observations, taken together, suggest a possibility that the penetration by a loop of alpha-LA segment into the phospholipid bilayer is responsible for the fusion.

Amino Acid Sequence↗
PubMed1986

Ascending spinal pathway for arterial pressor response elicited by ventral root afferent inputs in the cat.

In an attempt to localize the spinal ascending pathway for ventral root afferent inputs, changes in ventral root stimulation-evoked arterial blood pressure responses were observed in anesthetized cats after selective spinal lesions. The results of these experiments indicate that the ascending spinal pathways responsible for the pressor response lie in the dorsal-most part of the lateral funiculus. The pathway was found to be bilateral, and it is likely to occupy the same area throughout the entire length of the spinal cord.

Afferent Pathways↗
PubMed1986

Human IgG subclass assays using a novel assay method.

To facilitate assays for human IgG subclasses, we have adapted a novel assay method (particle concentration fluorescence immunoassay) (Jolley et al., 1984; MacCrindle et al., 1985) using one polyclonal and several monoclonal antibodies for human IgG subclasses. The advantages of this new assay over previously described methods are sensitivity (0.3-3 micrograms/ml), and automated measurement of multiple samples in a short time (2 h). We found that a monkey antibody for IgG2 and monoclonal antibodies for IgG1, IgG4b epitope, and IgG3 can be adapted to this method. We evaluated 7 different antibodies to IgG4 without finding a suitable monoclonal antibody for this assay method. Several of these IgG4 hybridoma antibodies, however, could be used in a competitive radioimmunoassay using polyvinyl microtiter plates. The usefulness of a monoclonal antibody to the IgG4b epitope was evaluated because no suitable monoclonal antibodies for IgG2 are available. Because IgG4 levels are usually much smaller than IgG2 levels, and the IgG4b epitope is expressed on all IgG2 alleles and only some IgG4 alleles (Kunkel et al., 1970), the antibody for IgG4b is potentially useful to screen a large number of samples for IgG2 deficiency. However, when the monoclonal antibody for IgG4b was compared with an IgG2 specific antibody produced in a monkey, the IgG4b antibody could identify only about half of the patients with known IgG2 deficiency.

Antibodies, Monoclonal↗
PubMed1986

Crystallization of a complex of cro repressor with a 17 base-pair operator.

Crystals of the lambda cro repressor complexed to a 17 base-pair synthetic binding site related to the OR3 operator have been obtained. The complex crystallizes in the hexagonal space group P6(2) (or P6(4)) with unit cell dimensions a = b = 154.8 A, c = 85.6 A. Preliminary photography reveals that the crystals are stable to X-rays and display measurable reflections to a resolution of about 3.7 A. The diffraction patterns suggest that the cro-DNA complexes are arranged in an open hexagonal network with the DNA fragments stacked end-to-end. The DNA is in the B-form but appears to be bent or curved into an approximate superhelix.

Bacteriophage lambda↗