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Biomedical subjects

K T Lin

Publications and source records attributed to K T Lin.

At least 55 records · Page 3Linked to original sources
PubMed1983

Sample preparation and estimation of plasma concentration of 3-deazauridine by high-performance liquid chromatography.

A rapid and simple procedure for liquid chromatographic analysis of plasma 3-deazauridine (3-DU), an antineoplastic agent, was developed. The plasma was extracted with methanolic silver acetate to remove interfering ultraviolet-absorbing materials and the 3-DU partially purified on a small anion exchange column prior to chromatography on a reverse-phase (C18) column. 2'-O-Methyl-3-deazauridine was used as an internal standard. The mobile phase was 0.1 M ammonium acetate, pH 4.0, containing 5% methanol. The 3-DU was identified by its retention time and its characteristic ultraviolet absorbance ratio (280/254 nm) of 3.0. This method was used to determine the plasma concentration of 3-DU in three patients with acute leukemia. The patients received a 36-h infusion of 3-DU at a rate of 5.0 mg/kg/h. The mean steady-state plasma concentration of 3-DU at the end of the infusion was 22.1 micrograms/ml (range, 13.6-42.8 micrograms/ml) and the mean elimination half-life was 109 min (range, 92-136 min). 2,4-Dihydroxypyridine, a potential metabolite of 3-DU, was not detected in any of the plasma samples of the patients receiving a 3-DU infusion.

3-Deazauridine↗
PubMed1982

Simplified procedure for the analysis of 3- and 4-hydroxyproline.

A column chromatographic analysis for 3-hydroxyproline (3-Hyp), 4-hydroxyproline (4-Hyp), and gamma-carboxyglutamic acid (Gla) is described. The analyses of urine and plasma were performed with a JLC-6AH amino acid analyzer. A 0.15 M sodium citrate buffer, pH 2.1, was used for elution. Urinary Gla, 3-Hyp, and 4-Hyp were among the seventeen peaks eluted before aspartic acid. Hyp, Gla, glutamine, and asparagine in plasma were separated by elution with 0.2 M sodium citrate buffer, pH 3.25, containing 10% methanol. This single-column procedure achieves the sequential separation and quantitation of Gla, 3-Hyp, and 4-Hyp in urine as well as plasma, and is applicable to the diagnosis of collagen metabolism disorders.

Autoanalysis↗
PubMed1982

Immune response of neonates to pneumococcal polysaccharide-protein conjugate.

Immune responses were studied in adult and young mice exposed to pneumococcal 6A and 19F polysaccharides (PSs), as well as 19F PS conjugated to proteins, e.g. human immunoglobulin G (HIgG), pneumococcal R61 cell wall polypeptide, and bovine serum albumin (BSA). Significantly higher IgM and IgG2 antibody titres were induced in mice receiving 19F PS-protein conjugates than in the control group receiving 19F PS alone. Maternal immunization with 19F PS-HIgG conjugate elicited a low immune response in the offspring. However, when young mice from immunized mothers were given and additional dose of polysaccharide-protein conjugate, they gave an antibody response greater than that of mice not given additional immunogen. Similarly, young mice exposed to 14-valent pneumococcal vaccine during gestation produced higher antibody response to 6A and 19F PSs. Secondary immunization of 19F PS or PS-protein conjugate at 1 or 2 weeks after primary immunization did not enhance antibody formation but rather suppressed the immune response to that polysaccharide.

Animals↗
PubMed1981

High-performance liquid chromatographic analysis of chemical stability of 5-aza-2'-deoxycytidine.

The chemical stability of 5-aza-2'-deoxycytidine (I) in acidic, neutral, and alkaline solutions was analyzed by high-performance liquid chromatography. In alkaline solution, I underwent rapid reversible decomposition to N-(formylamidino)-N'-beta-D-2-deoxyribofuranosylurea (II), which decomposed irreversibly to form 1-beta-D-2'-deoxyribofuranosyl-3-guanylurea (III). The pseudo-first-order rate constants for this reaction were determined. The decomposition of I in alkaline solution was identical to that reported previously for the related analog, 5-aza-cytidine. However, in neutral solution (or water), there was a marked difference in the decomposition of I and 5-azacytidine. The same decomposition products were formed from 5-azacytidine in neutral solution as in alkaline solution. However, in neutral solution, I decomposed to II and three unknown compounds that were chromophoric at 254 nm. Compound I was most stable when stored in neutral solution at low temperature.

Azacitidine↗
PubMed1980

Simultaneous studies of serum and urinary proteins for evaluation and diagnosis of glomerular damages in proteinuric patients.

Simultaneous studies of serum and urinary proteins in 294 adult proteinuric patients are presented. Our data showed that these studies can provide valuable guides for clinical diagnosis. In the group of idiopathic nephrotic syndrome, hypoalbuminemia, hypogammaglobulinemia and hyper-alpha 2 globulinemia were most marked. Urinary protein electrophoresis (PEP) showed a well-selective pattern with albumin and beta globulin as the main constituents. In the other groups of proteinuric patients the hypoalbuminemia and hyper-alpha 2 globulinemia were milder and urinary PEP generally showed non-selective pattern. In the groups of acute glomerulonephritis and lupus nephropathy, C3 was generally decreased; polyclonal gammopathy was frequently encountered and alpha 1 acid glycoprotein was markedly increased. In the cases of chronic glomerulonephritis and diabetic nephropathy and the levels of gamma globulin, C3 and alpha 2 acid glycoprotein were usually within normal limits. Urinary protein selectivity index in this series of adult patients was not a useful diagnostic parameter.

Adolescent↗
PubMed1980

Separation and purification of myeloma proteins.

Three myeloma proteins, IgG lambda, IgA lambda and IgM lambda, were identified by protein electrophoresis (PEP), immunoglobulin quantitation and immunoelectrophoresis (IEP). Preparative block electrophoresis was generally carried out as an initial step to separate the myeloma proteins. The myeloma proteins thus separated were then passed through either diethylaminoethyl (DEAE) ion exchange chromatography and recycled in a Sephadex G-200 column, or first through gel filtration and recycled in DEAE. An attempt to bypass the step of preparative electrophoresis in the separation of IgG myeloma protein by passing the serum directly into a DEAE column was proved to be inappropriate. The IgM myeloma protein had a marked tendency to cryoprecipitate and to form euglobulin, and this property was utilized to separate the crude myeloma protein. The purified myeloma protein fractions were concentrated and dialyzed with Ultrafiltration (Amicon) and retested for purity with PEP, double diffusion (DD) and IEP. Some special physiochemical properties which affected the purification procedures are discussed.

Aged↗
PubMed1980

An immunochemical study of two Bence-Jones proteins.

Two Bence-Jones proteins, one of kappa and the other of lambda type, from the urine of two myeloma patients were identified by protein electrophoresis (PEP) and immunoelectrophoresis (IEP). Urine specimens were concentrated and dialyzed with Ultrafiltration. The concentrated products were passed through a Sephadex G-100 column, and the fractions of Bence-Jones proteins were recycled in diethylaminoethyl (DEAE) ion exchange chromatography. Purified Bence-Jones proteins were mixed thoroughly with complete Freund adjuvant and inoculated into rabbits. The monospecific antisera to kappa and lambda chains were obtained by absorption with Bence-Jones proteins of the opposite types.

Adult↗
PubMed1978

Haemoglobin Vanderbilt (alpha2beta289Ser leads to Arg): a new haemoglobin with high oxygen affinity and compensatory erythrocytosis.

Haemolysates of family members from three generations, all of whom had polycythaemia, were analysed by polyacrylamide gel electrophoresis at pH 8.8. Two closely spaced major bands were observed, one of which corresponded to Hb A and the other to a new mutant designated Hb Vanderbilt. Whole blood from a heterozygote for Hb Vanderbilt was analysed for oxygen affinity which was found to be much higher than that of normal subjects. Haemoglobin Vanderbilt was separated from Hb A using anion exchange chromatography. Cation exchange chromatography yielded a variant beta chain from which a mutant peptide was identified with a structure corresponding to residues beta83--89 with a Ser leads to Arg replacement at position 89. The oxygen affinity of 'stripped' haemolysates from the heterozygote was found to be much less sensitive to added organic phosphates than haemolysates from normal subjects. In while blood, the decreased sensitivity to 2,3-diphosphoglycerate results in an increased oxygen affinity, thus explaining the clinical observations of tissue hypoxia and compensatory polycythaemia.

Aged↗
PubMed1977

Purification, partial characterization, and immunological relationships of multiple low molecular weight protease inhibitors of soybean.

Five protease inhibitors, I--V, in the molecular weight range 7000--8000 were purified from Tracy soybeans by ammonium sulfate precipitation, gel filtration on Sephadex G-100 and G-75, and column chromatography on DEAE-cellulose. In common with previously described trypsin inhibitors from legumes, I--V have a high content of half-cystine and lack tryptophan. By contrast with other legume inhibitors, inhibitor II contains 3 methionine residues. Isoelectric points range from 6.2 to 4.2 in order from inhibitor I to V. Molar ratios (inhibitor/enzyme) for 50% trypsin inhibition are I = 4.76, II = 1.32, III = 3.22, IV = 2.17, V = 0.97. Only V inhibit chymotrypsin significantly (molar ratio = 1.33 for 50% inhibition). The sequence of the first 16 N-terminal amino acid residued of inhibitor V is identical to that of the Bowman-Birk inhibitor; all other observations also indicate that inhibitor V and Bowman-Birk are identical. The first 20 N-terminal amino acid residues of inhibitor II show high homology to those of Bowman-Birk inhibitor, differing by 1 deletion and 5 substitutions. Immunological tests show that inhibitors I through IV are fully cross-reactive with each other but are distinct from inhibitor V.

Amino Acid Sequence↗
PubMed1977

Purification and properties of a polymorphic high activity equine erythrocyte carbonic anhydrase.

A polymorphic form of the high activity or C-type of horse erythrocyte carbonic anhydrase has been isolated. It has been designated C2 and differs from the usual C1 form by having a cysteine replacement for arginine at residue 180. This second cysteine, unlike the other, is highly reactive. Isolation of the C2 isozyme by the usual methods results in most of it forming a mixed disulfide with glutathione and this product designated as C3 has an increased anodic mobility. The enzymatic activity and immunologic reactivity of both the C2 and C3 components are the same as for the usual C1 form of the enzyme. The C2 form can be stabilized by alkylation and the carboxamidomethyl derivative has been isolated in crystalline form.

Amino Acid Sequence↗
PubMed1977

Humoral components of immunological response in nephrotic syndrome.

Serum and urine were collected from 58 patients with nephrotic syndrome. Immunoglobulins (IgA, IgG and IgM), complement (C3) and transferrin levels were measured by single radial immunodiffusion. The extent of glomerular injury was estimated by determining the selectivity of proteinuria. The relationship between the severity of glomerular damage and serum concentrations of immunoglobulins and complement was assessed. Higher IgM and lower IgG serum concentrations were found in nephrotic patients than in normal controls (157 +/- 108 mg+ vs 127 +/- 38 mg% for IgM, 929 +/- 537 mg% for IgG). The difference was statistically significant (p less than 0.05 for IgM, p less than 0.001 for IgG). No correlation was present between the selectivity of proteinuria and serum levels of IgA, IgM, IgG or C3. The results indicate that abnormalities in humoral components of the immune system are present in nephrotic patients and are probably related to a basic immunological defect in the patients rather than to the severity of glomerular damage.

Complement C3↗