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Biomedical subjects

F Gejyo

Publications and source records attributed to F Gejyo.

At least 217 records · Page 12Linked to original sources
PubMed1986

Beta 2-microglobulin: a new form of amyloid protein associated with chronic hemodialysis.

Carpal tunnel syndrome (CTS) has been associated with amyloid deposits and is now regarded as a major complication in chronic hemodialysis patients. While this new syndrome has been receiving increasing attention, its etiology has not been clarified. We have isolated amyloid fibrils from amyloid laden tissues inside the carpal tunnel in four different hemodialysis patients with CTS. After solubilization in guanidine HCl, a significant amount of the protein was located in a homogeneous, low molecular weight fraction. Each protein was found to be identical to beta 2-microglobulin with regard to its molecular weight of 11,000 on SDS-PAGE, amino acid composition and N-terminal amino acids: Ile-Gln-Arg-Thr-Pro-Lys-Ile-Gln-Val-Tyr-Ser-Arg-His-Pro-Ala-Glu. In direct immunofluorescent study, anti-beta 2-microglobulin did react positively with amyloid deposits. These results demonstrate that the amyloid associated with chronic hemodialysis contains as major component a new form of amyloid fibril protein that is homologous to beta 2-microglobulin. It is postulated that beta 2-microglobulin cannot be removed from the blood by conventional hemodialysis, and accumulates in tissues causing the formation of amyloid fibrils, which, having a relatively high affinity to the carpal tunnel area, thus causes CTS.

Amino Acids↗
PubMed1985

A new form of amyloid protein associated with chronic hemodialysis was identified as beta 2-microglobulin.

Amyloid fibrils were isolated from amyloid-laden tissue obtained from a chronic hemodialysis patient with carpal tunnel syndrome. After solubilization in guanidine HCl, a significant amount of the protein was located in a homogeneous low molecular weight fraction. The protein was found to be identical to beta 2-microglobulin, with regard to its molecular weight of 11,000, amino acid composition and 16 amino-terminal amino acids: Ile-Gln-Arg-Thr-Pro-Lys-Ile-Gln-Val-Tyr-Ser-Arg-His-Pro-Ala-Glu-. These results demonstrate that the amyloid associated with chronic hemodialysis contains as major component a new form of amyloid fibril protein that is homologous to beta 2-microglobulin.

Amino Acid Sequence↗
PubMed1985

Physiologic approach to dialysis-induced hypoxemia. Effects of dialyzer material and dialysate composition.

This study was undertaken to evaluate the effects of membrane-related complement activation and dialysate composition on dialysis-associated hypoxemia. Seven chronic hemodialysis patients were hemodialyzed 3 times sequentially with the following three combinations; Cuprophan membrane with acetate dialysate, polymethylmethacrylate (PMMA) membrane with acetate dialysate, and PMMA membrane with bicarbonate dialysate. During dialysis with acetate dialysate, the pulmonary diffusing capacity (DLco) at 30 min after the start of dialysis was decreased to 88% (p less than 0.01) of the predialysis value with PMMA and to 79% (p less than 0.01) with Cuprophan, and the degree of DLco on PMMA membrane was different from that on Cuprophan (p less than 0.01). The degree of leukopenia with PMMA was less than that with Cuprophan. However, the fall in DLco did not alter the alveolar-arterial O2 tension gradient. Although the changes in transcutaneous PO2 (tcPO2) were not constant in all three combinations, a distinct fall in tcPO2 was observed in the first half of dialysis with acetate dialysate. During dialysis with acetate dialysate but not with bicarbonate, the extracorporeal dialyzer removed an average of 60 ml/min of CO2, and the respiratory quotient dropped from a mean predialysis value of 0.86 to 0.59 (p less than 0.001). The arterial CO2 tension was not significantly changed throughout dialysis, but the alveolar ventilation decreased significantly in proportion to the fall in carbon dioxide output. The arterial tension fell from a control level of 91 +/- 6 to 77 +/- 8 mm Hg (p less than 0.01) in 30 min. It is concluded that, in spite of a fall in DLco, dialysis-induced hypoxemia in this group of patients on maintenance dialysis is caused by CO2 loss via the dialyzer, resulting in reflex hypoventilation.

Acetates↗
PubMed1985

Histochemical and immunohistochemical characterization of amyloid associated with chronic hemodialysis as beta 2-microglobulin.

The carpal tunnel syndrome has been associated with amyloid deposits and is now regarded as a major complication in patients undergoing chronic hemodialysis. The hemodialysis-associated amyloidosis appears to have systemic rather than local involvement, although its full extent is yet to be determined. In an attempt to examine the chemical and immunologic nature of the amyloid, the authors carried out a series of histochemical and immunohistochemical studies with the following results. The amyloid was "sensitive" to the "permanganate treatment," suggesting it was the AA (secondary) type. On immunohistochemistry, however, anti-human AA did not give positive reaction with the amyloid deposits, suggesting that this would be a new form of amyloid. As reported elsewhere, the authors' preliminary results on the amino acid sequence analysis in one specimen have revealed homology of its amino terminal sequence to beta 2-microglobulin. In the present study, anti-beta 2-microglobulin did indeed react positively (with appropriate controls) with the amyloid deposits in the tissues collected from five different patients, confirming the beta 2-microglobulin-related nature of the amyloid. The present observations are significant in two points: (a) they confirm that hemodialysis-associated amyloid is of beta 2-microglobulin origin since it shares same antigenic determinant(s) with it and since the amino acid sequence is homologous; and (b) it adds what many have suspected, i.e., "permanganate-sensitive" amyloid is not specific for the AA type but includes AA and beta 2-microglobulin amyloid deposits at the minimum.

Amyloid↗
PubMed1984

High-performance liquid chromatographic determination of serum aliphatic amines in chronic renal failure.

A high-performance liquid chromatographic method has been introduced for the determination of aliphatic amines in serum as their 2,4-dinitrophenyl derivatives. The method has been applied to the estimation of ethanolamine, methylamine and dimethylamine in serum from patients with chronic renal failure undergoing maintenance haemodialysis. Significant differences in the levels of both methylamine and dimethylamine were obtained between normal subjects and uraemic patients both predialysis and postdialysis. After a dialysis treatment, the levels of these two amines were reduced to approximately 55% in the patient group. Their mean values, however, were found to be about six times the values of the normal group. The degree of removal of these substances during haemodialysis was smaller than those for urea nitrogen and creatinine. On the other hand, the mean ethanolamine level before dialysis was close to that of controls, and yet a 2.3-fold increase was observed after dialysis.

Adult↗
PubMed1983

Characterization of the B-chain of human plasma alpha 2HS-glycoprotein. The complete amino acid sequence and primary structure of its heteroglycan.

alpha 2HS-Glycoprotein, a normal human plasma protein, was recently shown to consist of two polypeptide chains. In the present study, we have separated these two chains from one another and have elucidated the complete primary structure of the B-chain. Employing automated Edman degradation, the polypeptide moiety of this chain was shown to consist of 27 amino acid residues with an unequal distribution of the neutral and charged amino acid residues. The first 20 residues are uncharged, whereas the carboxyl-terminal heptapeptide contains all charged residues. Utilizing 500-MHz 1H-NMR spectroscopy, the carbohydrate unit proved to be a trisaccharide consisting of sialic acid, galactose, and N-acetylgalactosamine O-glycosidically linked to serine (residue 6). The structure of the B-chain was found to be as follows. (formula; see text) Thus, the molecular weight of the B-chain is 3386. Evaluation of the polypeptide chain by the procedure of Chou and Fasman (Chou, P.Y., and Fasman, G.D. (1979) Adv. Enzymol. 47, 45-148) predicts that the B-chain has two beta-turns. Thereby, the carbohydrate unit which is linked to the Ser residue located in the first beta-turn appears to be directed away from the protein. The second beta-turn probably includes the Cys residue which links the B- to the A-chain. In agreement with the CD analysis, the B-chain lacks beta-conformation but possesses a short alpha-helical region.

Amino Acid Sequence↗
PubMed1983

Alpha 2HS-glycoprotein in the serum and urine of patients with renal diseases.

The concentration of alpha 2HS-glycoprotein (alpha 2HS-GP), as measured by the single radial immunodiffusion technique in the sera of 52 patients with various renal diseases and varying degrees of proteinuria, was found to be significantly reduced (P less than 0.001) when compared to the control values. Out of the 52 patients examined, 34 were found to excrete alpha 2HS-GP in urine with no correlation between the serum and urine levels of this protein. Although there is a statistically significant correlation between the clearances of albumin and alpha 2HS-GP, in only six patients were the clearances of alpha 2HS-GP within +/- 25% of albumin clearance. Twelve had higher, and 16 had lower, relative clearances of alpha 2HS-GP. The relative clearance of alpha 2HS-GP had no relation to the serum levels of alpha 2HS-GP, but correlated with the degree of proteinuria and the type of histological lesion in the kidney. In conclusion, there is a quantitative reduction of serum alpha 2HS-GP in patients with renal diseases. It appears that the degree of proteinuria and the type of renal lesion influences its selective handling by the kidneys.

Blood Proteins↗
PubMed1983

Altered glycosylation and sialylation of serum proteins and lipid bound sialic acids in chronic renal failure.

Abnormalities in the metabolism of carbohydrates, lipids and proteins are well documented in chronic renal failure (CRF). We have studied the extent of glycosylation and sialylation of serum proteins and also the levels of lipid-bound sialic acids in nondiabetic patients with CRF maintained on haemodialysis. The total neutral sugar content (TNS) and the non-enzymatic glycosylation (NEG) of serum proteins, the protein-bound sialic acids (PSA) and the lipid-bound sialic acids (LSA) were found to be significantly elevated in the patients as compared to a group of healthy controls. A single dialysis therapy produced some alterations in these measurements. The TNS correlated significantly with the NEG and also with the PSA. No correlation existed between total lipids. None of these measurements, however, correlated with the serum creatinine values. The established as well as putative pathophysiological consequences of these findings are discussed.

Blood Proteins↗
PubMed1983

Prolidase and prolinase activities in the erythrocytes of patients with chronic uremia.

To elucidate the nature of the iminoacidopathy in uremia, the prolidase and prolinase activities in erythrocytes from 36 normal subjects, 28 patients with chronic uremia, and 21 patients on maintenance hemodialysis were determined. A statistically significant decrease in the activities of both prolidase and prolinase was found in the uremic patients and the hemodialysis group. No difference has been observed in the enzyme activities in the pre- and postdialysis samples of the hemodialysis patients. It is suggested that decreased activities of prolidase and prolinase may contribute to the iminoacidopathy in uremia, including high contents of serum iminoacid containing peptides.

Adult↗
PubMed1981

Purification and characterization of the two forms of human plasma alpha 2HS-glycoprotein.

The two forms of alpha 2HS-glycoprotein were purified from Cohn fraction VI of normal human plasma and characterized in terms of their major chemical and physicochemical properties. Separation of these two proteins was achieved by chromatography on DEAE-cellulose at pH 4.4 followed by gel filtration through Sephadex G-100. The isoelectric points of the disc gel electrophoretically and immunochemically homogeneous glycoproteins were found to be at 4.1 and 4.7 and their apparent molecular weights, as determined by SDS-polyacrylamide gel electrophoresis, were shown to be 51,000 and 56,000, respectively. The amino acid compositions of both proteins were very similar, although differences, particularly in the arginine and histidine contents, were noted. The amino- and carboxyl-terminal amino acids were found to be the same for both proteins and were threonine and alanine, and valine and leucine, respectively, suggesting that both forms of this protein consist of two polypeptide chains. The total carbohydrate moiety of the relatively basic form (14%) proved to be comparable to that of the relatively acidic form (13%). More important, however, the sialic acid content of the latter was higher than that of the former. These results suggest that the difference between the two forms of alpha 2HS-glycoprotein resides both in its carbohydrate and polypeptide moieties.

Amino Acids↗
PubMed1981

Identification of N-monoacetylcystine in uraemic plasma.

1. An unidentified ninhydrin-positive substance of an acidic nature was detected in the plasma of uraemic patients. This substance was isolated from haemodialysate by ion-exchange chromatography and gel filtration, and identified as a sulphur-containing amino acid: N-monoacetylcystine. 2. The quantitative determination of sulphur amino acids in plasma revealed that the plasma levels of cysteic acid, homocysteic acid, taurine, cystine and cystathionine as well as N-monoacetylcystine in uraemic patients were markedly higher than in normal subjects (P less than 0.001 for each). However, the plasma levels of methionine in uraemic patients were within normal limits.

Amino Acids, Sulfur↗
PubMed1981

Studies on prolidase deficiency with a possible defect in collagen metabolism.

Skin collagen of a female patient with prolidase deficiency was examined for the distribution of borohydride-reducible cross-links and the proportion of type III to type I collagen. Patient's skin contained after reduction more dihydroxylysinonorleucine relative to hydroxylysinonorleucine and type III collagen than expected for normally matured skin. These findings suggest that collagen of the patient's skin failed to follow a time-related normal maturation process and the collagen metabolism was disturbed. The composition of urinary collagen metabolites was also unusual. On the the other hand, her asymptomatic brother with prolidase deficiency showed the normal urinary compositon of collagen matabolites. It is suggested that prolidase deficiency and defect in collagen metabolism independent of it are both responsible for clinical manifestation.

Collagen↗
PubMed1980

Hemodialysis-associated asthma in a renal failure patient.

In a renal failure patient, asthma developed after 1 year hemodialytic treatment. The attack was exclusively associated with each hemodialysis. Skin test to the usual allergen such as house dusts or pollens was negative. The provocation test by inhaling acetate solution or oral intake of acetic acid was positive resulting in an increase in the pulmonary resistance, or asthmatic attack. This asthma disappeared completely after substitution of acetate in the hemodialysis by the use of a bicarbonate dialysate. Acetate might therefore precipitate the attack of asthma.

Acetates↗
PubMed1979

Prolidase deficiency with imidodipeptiduria. A familial case with and without clinical symptoms.

A 23-year-old female with chronic leg ulcer was found to excrete the massive imidopeptides, among which Asp-Pro, Glu-Pro and Gly-Pro were identified. Essentially no prolidase activity was measured in her erythrocytes, while prolinase activity was within a normal range. Her 26-year-old brother also showed imidopeptiduria and erythrocyte prolidase deficiency, but no clinical symptoms were observed. Erythrocytes from her father and 30-year-old brother, who excreted no significant amounts of imidodipeptides, showed intermediate values for the prolidase activity between those for the patient and for normal adults, suggesting that they are heterozygous for this autosomal recessive disorder.

Adult↗
PubMed1979

Effect of acetate upon arterial gases.

Following infusion of sodium acetate, a significant fall in arterial oxygen tension (PO2) was observed (p less than 0.001). A rise in PCO2 or bicarbonate was also statistically significant. pH was however remained unchanged. Though a rise in PCO2, bicarbonate, pH was observed following infusion of sodium bicarbonate, no significant fall in PO2 was observed. These results suggest a role of acetate ion for the fall of arterial oxygen tension; the hemodialysis-induced hypoxemia.

Acetates↗