Fas antigen expression in brains of patients with Alzheimer-type dementia

Fas antigen (CD95) is a cell surface protein that mediates apoptosis. We have investigated the immunohistochemical localization of Fas antigen in postmortem brain tissue from control subjects, patients with Alzheimer-type dementia (ATD), and from a few patients with diffuse Lewy body disease, progressive supranuclear palsy and adrenoleukodystrophy. In all brains, including controls, vascular endothelial cells and residual blood plasma were weakly stained. In ATD brains, senile plaques and a small number of star-like cells were brains of patients with neurological diseases other than ATD. In double immunostaining for Fas and glial fibrillary acidic protein (GFAP), a small number of cells were positive for both antigens. The majority of Fas-positive astrocytes were, however, negative for GFAP. This implies the downregulation of GFAP production in these cells. Doubly labeled astrocytes were also found around senile plaques, suggesting that the Fas immunoreactivity in senile plaques was derived from astrocytic membranes. The results of this study indicate that Fas antigen is expressed by a subset of reactive astrocytes in degenerative neurological diseases. Such astrocytes may undergo the Fas-mediated apoptotic process.

On the real structure of the cytoplasmic matrix: learning from the embedment-free electron microscopy

The recent debate on the nature of the cytoplasmic matrix is reviewed on the basis of results obtained by electron microscopy of embedment-free materials, i.e., the critical point-dried whole mount-cell method, the polyethylene glycol (PEG)-embedding and subsequent de-embedding section method, and the freeze-etching method. Fine structural images obtained by these methods are carefully evaluated and close correspondence with electron microscopy regardless of these methods is demonstrated. Especially, 'novel' filamentous structures--the microtrabecular strands and the cross-linkers--correspond well to each other; they are structures which have been included in epoxy sections by conventional methods, but have been obscured simply because of a similar property of electron scattering between the filamentous structures and epoxy resin. Although this correspondence seems to support the existence of the microtrabeculae, the electron microscopy of serum albumin, when processed by the PEG-method, also exhibits filamentous networks resembling the microtrabecular lattice. This, together with the finding on the centrifugation of in situ cells, strongly suggests a possibility that most, if not all, microtrabecular strands and cross-linkers in cells without pretreatment by detergents do not represent actual in situ structures.

Degree of external force to the left ventricle determines hemodynamic response to nitroprusside in failing hearts: comparison with the response to dobutamine

Vasodilators frequently, although not always, increase cardiac output (CO) in patients with congestive heart failure (CHF) despite a decrease in left ventricular (LV) diastolic pressure. In patients with CHF, vasodilator-induced decrease in LV diastolic pressure without decrease in "preload" plays an important role in the vasodilator-induced increase in CO failure that may be caused by a vasodilator-induced reduction in external force to the LV. To clarify the hypothesis that a hemodynamic response to vasodilators depends on the degree of external force to the LV in failing hearts before drug administration and to examine whether the degree of the external force also affects a hemodynamic response to positive inotropic agents, we produced in 17 dogs two different conditions of LV dysfunction with high LV end-diastolic pressure (EDP: > or = 15 mm Hg), i.e., 1 with high right ventricular (RV) EDP (condition 1) and the other with lower RVEDP than condition 1 (condition 2), and compared hemodynamic effects of nitroprusside or dobutamine between these two conditions. Condition 1 was produced by the injection of a small dose of microspheres into the left coronary artery and intravenous infusion of dextran. Condition 2 was produced only by the injection of a large dose of microspheres. The nitroprusside-induced decrease in LVEDP was associated with a greater decrease in RVEDP and lesser decreases in mean left atrial pressure and LV end-diastolic diameter in condition 1 than in condition 2. CO increased in condition 1; however, CO then decreased in condition 2. The nitroprusside-induced changes in CO inversely correlated with those in RVEDP (r = 0.65, p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Fetal-adult phenotype transition, in terms of the serum dependency and growth factor requirements, of human skin fibroblast migration

Since the migration of human fetal skin fibroblasts into a denuded area of a cell monolayer has been demonstrated to be serum-independent (fetal phenotype), whereas that of adult-donor skin fibroblasts is serum-dependent (adult phenotype), a study was carried out to determine at which life stage the fetal-adult phenotype transition, in terms of serum dependency of human skin fibroblast migration, occurs. The results demonstrated that this phenotype transition occurred before birth, and, therefore, the fetal skin fibroblast phenotype differed from those of infant-, child-, adult-, and elderly-donor skin fibroblasts. But, the fetal-, child-, and adult-donor skin fibroblast phenotypes did not change during in vitro aging. On the other hand, the growth factor requirement for human skin fibroblast migration changed similarly to the serum dependency for fibroblast migration: the signal for fibroblast migration changed from basic fibroblast growth factor for the fetal phenotype to platelet-derived growth factor for the adult phenotype.

Basal release of endothelium-derived nitric oxide plays an important role in the prevention of afterload mismatch in acute left ventricular dysfunction

The basal release of endothelium-derived nitric oxide (EDNO) is considered to play an important role in regulating the vascular tone in normal subjects; however, its role in the presence of acute heart failure is unknown. This study was designed to clarify the role of a basal release of EDNO in the presence of acute heart failure. Acute ischemic left ventricular (LV) dysfunction was produced in 22 dogs by coronary microembolization. After the embolization, only saline solution was intravenously infused for sixty minutes in 10 dogs. In another 12 dogs, NG-monomethyl-L-arginine (L-NMMA), which is known to inhibit the formation of EDNO in the vascular endothelium, was intravenously infused at a rate of 20 micrograms/kg/minute for sixty minutes. Infusion of saline solution did not produce any changes in hemodynamic variables. Infusion of L-NMMA caused increases in mean aortic pressure, systemic vascular resistance, and LV end-diastolic pressure without changes in the LV peak + and - dP/dt (time constant) of LV pressure fall, and these changes were associated with a giant "v" wave in the tracing of left atrial pressure and a decrease in cardiac output. The basal release of EDNO may play an important role in the prevention of afterload elevation, subsequent cardiac output reduction, and afterload mismatch in the presence of acute heart failure.

Progressive intraventricular drop of early diastolic flow velocity reflects impaired active ventricular diastolic function in hypertensive heart disease: comparative study between early diastolic and atrial contraction phases

Left ventricular (LV) diastolic function in the early diastolic phase includes both active and passive processes, but in the atrial contraction phase it includes only passive processes. To elucidate the relation between the intraventricular dispersion of the flow velocity in diastole and LV diastolic process, 31 normal volunteers and 12 patients with hypertensive heart disease were studied. In these subjects the flow velocity pattern at the mitral tip was recorded simultaneously with regional flow velocity patterns 1, 2, or 3 cm from the mitral tip toward the apex, respectively, with multigate pulsed Doppler echocardiography from the apical long-axis view with the guidance of Doppler color-flow imaging. Although the ratio of regional peak flow velocity/mitral peak flow velocity in the atrial contraction phase decreased from the mitral tip to the apex to the same degree in the normal volunteers and patients with hypertensive heart disease, there was a significant difference in the intraventricular dispersion of the early diastolic flow velocity between the two groups. These results suggest that the progressive intraventricular drop of the flow velocity in the early diastolic phase in patients with hypertensive heart disease may reflect the impairment of active rather than passive LV diastolic function.

[Quality of life, subjective health status and health and life satisfaction in rheumatoid arthritis]

A Japanese version of Arthritis Impact Measurement Scales (AIMS) was developed after the original AIMS Version 2 and utilized for Quality of Life (QOL) measurement in 691 patients with Rheumatoid Arthritis (RA). Various medical (physical and laboratory) examinations, which are widely used in the clinical settings for the assessment of RA activity and severity, were also performed by physicians. Interrelationships between QOL, patient subjective health status, and health and life satisfaction were analyzed with the following results: 1: The effect of QOL impairment by RA upon patients' subjective health rating and health satisfaction were not constant over the range of severity of disease status. Pain was found to lower overall subjective health and health satisfaction regardless of RA class. On the other hand, while the deterioration of mobility aspects of QOL had negative effects upon patients' subjective health status and satisfaction among less-disabled RA patients, any of physical aspects of QOL, including the degree of mobility impairment, showed no significant association with patients' subjective health status and satisfaction in the more disabled. 2: Psychological aspects of QOL (mood and tension) had significant associations with patients' subjective health status and satisfaction. In the less severe group, mood impairment had a significant effect on subjective health and satisfaction, while in the more severe group tension showed a significant association. It was indicated that management of psychological aspects of QOL is important in RA patients to improve and advance their subjective health status and satisfaction. 3: Although social aspects of QOL, i.e. social support, social life and job status, showed no significant relationship to subjective health rating and health satisfaction, those with less disease severity who lacked social support and who had a jobless state were likely to have lower disease acceptance and life satisfaction, while those with more severe disease who had less social interaction manifested lower life satisfaction. These results suggested that social aspects of QOL, while not directly associated with subjective health rating, could be important factors affecting disease acceptance and life satisfaction.

Alzheimer-type pathology in melanin-bleached sections of substantia nigra

Bleaching of melanin prior to Gallyas staining enabled us to detect an unexpectedly large number of neurofibrillary tangles (NFTs; 62 and 50 NFTs in the upper and the lower substantia nigra, respectively, mostly in the neuronal cytoplasm of the medial zona compacta) in brains of patients who had had Alzheimer's disease. Amyloid-like deposits were quite scarce. In Alzheimer's disease it has been commonly observed that other subcortical nuclei projecting widely to the cerebral cortex also contain a large number of NFTs, although they have few amyloid deposits. In these subcortical nuclei retrograde degeneration may initially affect intraneuronal processes, leading to the preferential development of NFTs in the neuronal cytoplasm.

Jh gene sequence analysis in a patient with Waldenström's macroglobulinaemia with subsequent development of immunoblastic lymphoma

A case of Waldenström's macroglobulinaemia with subsequent development of immunoblastic lymphoma in a 69 year old man is reported. Plasmacytoid lymphocytes were initially observed in both peripheral blood and bone marrow smears. Lymph node biopsy was interpreted as malignant lymphoma, diffuse mixed cell type compatible with Waldenström's macroglobulinaemia. Complete remission resulted on combined treatment with prednisolone and melphalan. Four years later, lymphadenopathy recurred and biopsy revealed the development of an immunoblastic lymphoma. Initially, this lymphoma was thought to be the malignant transformation of Waldenström's microglobulinaemia, because both tumours produced IgM (kappa light chains). Sequencing of immunoglobulin heavy chain genes ofWaldenström's macroglobulinaemia and immunoblastic lymphoma cells, however, revealed different Dh and Jh usage between the two, indicating the independent nature of the two haematological malignancies. These results indicate that clonality of primary and secondary tumours should be determined not by phenotypic, but by genotypic analysis.

The effect on methamphetamine on the mRNA level for 14.3.3 eta chain in the human cultured cells

14.3.3 protein, a brain-specific protein, is an activator of tyrosine and tryptophan hydroxylases, key enzymes for biosynthesis of dopamine and serotonin. In this article, we describe cloning of cDNA for human brain 14.3.3 eta chain and expression of 14.3.3 eta chain mRNA in some human cultured cells. The cloned cDNA is 1730 bp long and contains 191 bp of a 5'-noncoding region, the complete 738 bp of coding region, and 801 bp of a 3'-noncoding region, containing three polyadenylation signals. This cDNA encoded a polypeptide of 246 amino acids (M(r) 28,196). Furthermore, using in situ hybridization histochemistry, the expression of mRNA for this protein was examined in the rat central nervous system. In situ hybridization histochemistry indicated that 14.3.3 eta chain mRNA is detected not only in the monoamine-synthetic neurons, but also in other neurons in the discrete nuclei, which synthesize neither cathecholamine nor serotonin. Northern blot analysis demonstrated that the addition of methamphetamine into the cultured medium increased the mRNA level for 14.3.3 eta chain in U-251 cells, but did not increase that of GFAP.

Numerous glial fibrillary tangles in oligodendroglia in cases of subacute sclerosing panencephalitis with neurofibrillary tangles

Both neurons and oligodendroglia are preferentially infected in subacute sclerosing panencephalitis (SSPE). Massive argyrophilic and tau-positive glial fibrillary tangles (GFT) were found in oligodendroglia in two autopsy cases of SSPE with neurofibrillary tangles (NFT). GFT shared common phosphorylated tau-epitopes with NFT, but were negative for ubiquitin. Electron microscopically, GFT consisted of compact bundles of irregularly woven tubules. Thus, GFT in SSPE differed from NFT showing regular constriction of tubules and from GFT in some other cytoskeletal disorders in which GFT reportedly consisted of straight tubules.

Determination of tributyltin and triphenyltin compounds in hair and fish using a hydrolysis technique and gas chromatography with flame photometric detection

A hydrolysis technique and a GC method are described for the determination of tributyltin and triphenyltin compounds in human hair and fish tissue. A sample was hydrolysed with a potassium hydroxide-ethanol-water solution. Tributyltin and triphenyltin compounds in the hydrolysate were extracted with toluene, and then impurities in the extract were eliminated with anion- and cation-exchange resins. After propylation of the organotin compounds, a yellow impurity was removed with a Sep-Pak florisil cartridge, and the two propylated organotin compounds were separated using a silicone OV-1 GC column and determined by flame photometric detection. The limits of determination of tributyltin and triphenyltin compounds in the sample were 5 and 10 ng g-1, respectively, in their chloride forms. The recoveries of tributyltin chloride from hair samples were 78.8 and 90.8%, respectively, when the spiked amounts were 20 and 200 ng. The recoveries of triphenyltin chloride from hair samples were 71.7 and 72.7%, respectively, when the spiked amounts were 40 and 400 ng. The recoveries of the organotin compounds from fish were similar to the recoveries from hair.

White matter amyloid in Alzheimer's disease brain

Amyloid beta-protein (A beta) deposits in the white matter were investigated by the double immunohistochemical staining for A beta and neuritic, glial or vascular components. Reactive astroglia and neurite abnormality were absent around A beta deposits in the white matter (w-A beta) even those with a core. The association of w-A beta with blood vessels was not consistent. Aggregates of activated microglia were found to be the sole but a consistent accompaniment of A beta deposits even in the absence of other components such as neuron, synapse, neurite abnormality and reactive astroglia, as observed in the white matter. This suggests that the aggregates of activated microglia most likely represent one of the factors promoting the process of A beta deposition.

Small adenocarcinoma of the lung. Histologic characteristics and prognosis

BACKGROUND

Although there are many reported prognostic indicators for pulmonary adenocarcinoma, the clinicopathologic characteristics and prognostic factors of early stage adenocarcinoma have not been evaluated fully, except for several studies of nonmucinous and sclerosing bronchioloalveolar carcinoma.

METHOD

Two hundred thirty-six surgically resected small peripheral adenocarcinomas measuring 2 cm or less in greatest dimension were reviewed using a simple histologic classification of six types based on tumor growth patterns.

RESULTS

Type A (localized bronchioloalveolar carcinoma [LBAC]) (n = 14) revealed replacement growth of alveolar-lining epithelial cells with a relatively thin stroma. In type B (LBAC with foci of structural collapse of alveoli) (n = 14), fibrotic foci due to alveolar collapse were observed in tumors of LBAC. Type C (LBAC with foci of active fibroblastic proliferation) (n = 141) was the largest group in this study, and foci of active fibroblastic proliferation were evident. Type D (poorly differentiated adenocarcinoma), type E (tubular adenocarcinoma) and type F (papillary adenocarcinoma with a compressive growth pattern) (n = 61) showed compressive and expanding growth. Types A and B showed no lymph node metastasis and the most favorable prognosis (100% 5-year survival) of the six types.

CONCLUSION

Histologic types A and B are thought to be in situ peripheral adenocarcinoma, whereas type C appears to be an advanced stage of types A and B. Conversely, types D, E, and F are small advanced adenocarcinomas with a less favorable prognosis.

[The validity and reliability of a Japanese version of Arthritis Impact Measurement Scales in patients with rheumatoid arthritis]

A Japanese version of Arthritis Impact Measurement Scales (Japanese-AIMS) was developed after the original AIMS Version 2 (AIMS 2). We then conducted a Quality of Life measurement of 691 patients with Rheumatoid Arthritis (RA) with this newly developed questionnaire. Based on the data collected, the validity and reliability of the Japanese-AIMS was examined. The validity of the Japanese-AIMS, which was assessed by the examination of internal consistency among items and through factor analysis, was almost comparable with that of the original AIMS 2. QOL scales were also validated using internal standards based on the subject's responses to other items in the questionnaire. The test-retest reliability, which was the correlation of scale scores between two tests administered 4-5 weeks apart, was slightly lower than the original one. We conclude that the validity and reliability of the Japanese AIMS were comparable with those of the original one, though there could be possibly improved by the minor revision of phrasing. The large scale QOL measurement study with RA patients is under way, using the Japanese-AIMS with minor revision.

Natural infection with attaching and effacing Escherichia coli and adenovirus in the intestine of a pigeon with diarrhea

Attaching and effacing Escherichia coli (AEEC) and adenovirus infections in a 6-month old pigeon were found by retrospective histologic examinations. Histologically, numerous gram-negative bacilli covered the surface of the enterocytes of the ileum. Brush borders were not sharply defined on the apical enterocytes at the sites of bacterial attachment. Scanning electron microscope showed that much of the mucosal surface was heavily colonized by bacilli and that the microvilli were lost. Many intranuclear inclusions were seen in enterocytes from the duodenum to the cecum. On transmission electron microscopy, adenovirus-like particles were observed in the nuclei of enterocytes.

Detection of anti-bovine beta 2-glycoprotein I antibody in sera from patients with antiphospholipid syndrome

We studied and characterized anti-bovine beta 2-glycoprotein I antibodies (aB beta 2-GPI) in sera from patients with antiphospholipid syndrome (APS) by ELISA. Bovine beta 2-glycoprotein I (beta 2-GPI) was purified by heparin affinity and DEAE ion-exchange chromatography, and identified on immunoblots using a monoclonal antibody against human beta 2-GPI and by amino acid sequence analysis. aB beta 2-GPI levels in the sera from 36 APS patients were measured by ELISA using purified bovine beta 2-GPI as an antigen. The mean +/- standard deviation level of aB beta 2-GPI was 17.4 +/- 22.0 units in the 58% of APS patients who were positive. There was a significant correlation (P = 0.003) between aB beta 2-GPI and anticardiolipin antibody (aCL) levels. aB beta 2-GPI from the sera of patients with APS was inhibited by bovine beta 2-GPI itself. Purified IgG from the sera of patients with APS showed that bovine beta 2-GPI was capable of acting as a cofactor for aCL. Purified bovine beta 2-GPI was useful antigen for conventional ELISA. aB beta 2-GPI may contribute to the further development of aCL analysis and to the understanding of the pathogenesis of APS.

A study of dementia with argyrophilic grains. Possible cytoskeletal abnormality in dendrospinal portion of neurons and oligodendroglia

Two mildly demented patients with emotional disorder presented massive cortical argyrophilic grains (ArG) in the limbic area and coiled bodies mainly in the white matter. Immunohistochemically, the ArG consisted of partially ubiquitinated full-length phosphorylated tau. A modified Gallyas-Braak method, used after potassium permanganate and oxalic acid pretreatment, revealed many filiform, knobby or pleomorphic spine-like appendages on the ArG. Double immunohistochemical staining using anti-tau with either anti-microtubule-associated protein 2 or anti-neurofilament 200K revealed that ArG were intimately associated with dendrites rather than with axons. Electron microscopic studies with tau immunohistochemistry and the Gallyas-Braak method revealed that the ArG were composed of bundles of smooth tubules of 25-nm diameter. The coiled body-bearing cells had the morphological characteristic of oligodendroglia. These results indicate that the presence of ArG is a cytoskeletal abnormality affecting predominantly the dendrospinal portions of neurons. A survey of diseases with cytoskeletal disorders revealed that a small number of similar argyrophilic granular structures are sometimes observed in progressive supranuclear palsy, Pick's disease with Pick bodies and corticobasal degeneration. Dementia with ArG is thought to be a unique cytoskeletal abnormality associated predominantly with the dendrospinal portions of neurons and oligodendroglia.

Molecular cloning of the cDNA for rat phosphatase inhibitor-2 and its wide gene expression in the central nervous system

Inhibitor-2 (I-2) is the cytosolic regulatory subunit of type 1 protein phosphatase. We cloned and sequenced a cDNA for rat I-2 from rat brain cDNA library. By in situ hybridization histochemistry, I-2 mRNA was expressed throughout the adult rat brain (on the postnatal 7th week) at various hybridization intensities: high expression signals were detected in the hippocampal formation, olfactory neuronal layers, choroid plexus and cerebellar Purkinje and granule cell layers. Moderate expression signals were detected homogeneously through the layers II-VI of the neocortex. On the embryonic day 15, 1-2 mRNA was expressed moderately in both ventricular and mantle zones of the fore-, mid-, hindbrain and spinal cord, suggesting the possible involvement of I-2 together with type 1 protein phosphatase (PP-1) in the regulation of various early neuronal events including mitosis, migration and differentiation.

Toluene induces behavioral activation without affecting striatal dopamine metabolism in the rat: behavioral and microdialysis studies

We examined the effects of toluene on the release of dopamine (DA) and its metabolites in rat striatum using microdialysis. Intraperitoneal injection of 800 mg/kg toluene significantly increased motor activity in rats, as did methamphetamine (MAP) (1 mg/kg). However, 800 mg/kg toluene did not affect the extracellular levels of DA, 3,4-dihydroxyphenylacetic acid, homovanillic acid, or 5-hydroxyindoleacetic acid. This is in contrast to MAP, which significantly increased extracellular DA and decreased the extracellular levels of its metabolites. These results suggest that toluene-induced behavioral augmentation may not be associated with alterations in DA or serotonin neurochemistry such as are associated with MAP-induced behavioral augmentation.

Localization of mRNAs of voltage-dependent Ca(2+)-channels: four subtypes of alpha 1- and beta-subunits in developing and mature rat brain

The heterogeneous gene expression for four subtypes of alpha 1 (A,B,C,D)- and beta (beta 1,beta 2,beta 3,beta 4)-subunits of voltage-dependent calcium channels was demonstrated in developing and adult rat brain by in situ hybridization histochemistry. In the adult rat brain the gene expression for A- and B-subtypes was predominant in the cerebellar cortex and hippocampal neuronal layers, with the A-subtype expressed most intensely in the Purkinje cells, while the expression for C- and D-subtypes was predominant in the olfactory mitral and granule cells and the dentate granule cells. The expression of beta 1-mRNA was prominent in the olfactory mitral cells and dentate granule cells whereas that of beta 2-mRNA was evident in the hippocampal neuronal layers and cerebellar Purkinje cells. The expression of beta 3-mRNA was prominent in the olfactory mitral and internal granule cells and medial habenula, whereas that of beta 4-mRNA in the olfactory mitral cells and cerebellar Purkinje and granule cells. Comparison between the expression patterns for individual alpha- and beta-subunits suggests that the beta 4-subunit contributes to P-type channel, whereas the beta 1- and beta 3-subunits contribute respectively to D- and C-subtypes of L-type channels, although dissociation in the expression patterns were also noted in several brain regions. In addition to neuronal populations, the gene expression for the C-subtype of L-type channel was detected at substantial level in glial cells. In developing brains, the genes for the all subtypes of alpha 1- and beta-subunits were expressed in the mantle zones, but not the ventricular zones, of the entire neuraxis and the expression was more or less attenuated during early postnatal periods in most of the brain regions except for the olfactory bulb, hippocampus and cerebellar cortex, suggesting that the Ca(2+)-channels are intimately involved in the neuronal differentiation.

Effects of aging and dietary restriction on activity of monkey serum in promoting fibroblast migration

In order to determine whether serum modified cellular aging in vivo, we previously studied the effects of serum from various mammals of different ages on cell functions such as proliferation and migration, and reported that cell migration was more greatly inhibited by serum from old donors than cell proliferation [1]. Moreover, since dietary restriction has been reported to extend lifespan and slow the aging rate of some animals [2], we wondered whether sera from dietary restricted and control monkeys of various ages might exhibit reduced aging effects on cell migration. When serum from young adult (3-5 years old) monkeys was added to plain medium, the migration of human fetal skin fibroblasts was very strongly inhibited compared to FBS. Surprisingly, sera from adult (6-11 years old) and old (more than 18 years old) monkeys caused significantly less migration-inhibitory activity than serum from young adult monkeys although sera from adult and old monkeys were much more inhibitory to cell migration than FBS. Dietary restriction only caused marginal effects on serum migration-promoting activity in a few monkey groups. The inhibition of cell migration caused by monkey serum was not brought about by cytotoxic effects since monkey serum stimulated cell proliferation as well as fetal bovine serum. These results indicate that the effects of aging on monkey serum migration-promoting activity are much more pronounced than those of dietary restriction.

Stabilized enzymatic reagents for measuring glucose, creatine kinase and gamma-glutamyltransferase with thermostable enzymes from a thermophile, Bacillus stearothermophilus

Stabilized enzymatic reagents for measuring some components in biological fluids have been successfully developed based on two kinds of thermostable enzymes derived from Bacillus stearothermophilus with separation of the reagent into two complementary solutions. The thermostable glucokinase produced was applied to the measurement of glucose and creatine kinase activity, while the alanine dehydrogenase produced was used for the measurement of gamma-glutamyltransferase activity. The enzymatic reagents were also stabilized by developing two separate reagents with an optimum pH for the main reagent components. The stability of the reagents in liquid form was examined at 10 degrees C. It was clearly shown that the reagents for measuring glucose and creatine kinase activity were stable and retained their full capability for accurate measurement in biological fluids for over one year. The alanine dehydrogenase product was stable for at least 40 days.