Two distinct anti-allergic drugs, amlexanox and cromolyn, bind to the same kinds of calcium binding proteins, except calmodulin, in bovine lung extract

In order to explore candidates for proteins required in exocytosis, we used two anti-allergic drugs, amlexanox and cromolyn, which inhibit IgE mediated degranulation of mast cells and basophils, as molecular probes in affinity chromatography. These two drugs chiefly bound to the same kinds of calcium binding proteins in bovine lung. These proteins were as follows: bovine calgranulin C homolog, an 8-kDa unknown protein, S-100L, calgranulin B, calcyphosine, and annexins I-V. The homologous affinity of the two drugs to these proteins is in accord with the similar anti-allergic property of both drugs. From these findings it is presumed that these drugs interact with these proteins and affect pharmacologically the degranulation.

A four-disulphide-bridged toxin, with high affinity towards voltage-gated K+ channels, isolated from Heterometrus spinnifer (Scorpionidae) venom

A new toxin, named HsTX1, has been identified in the venom of Heterometrus spinnifer (Scorpionidae), on the basis of its ability to block the rat Kv1.3 channels expressed in Xenopus oocytes. HsTX1 has been purified and characterized as a 34-residue peptide reticulated by four disulphide bridges. HsTX1 shares 53% and 59% sequence identity with Pandinus imperator toxin1 (Pi1) and maurotoxin, two recently isolated four-disulphide-bridged toxins, whereas it is only 32-47% identical with the other scorpion K+ channel toxins, reticulated by three disulphide bridges. The amidated and carboxylated forms of HsTX1 were synthesized chemically, and identity between the natural and the synthetic amidated peptides was proved by mass spectrometry, co-elution on C18 HPLC and blocking activity on the rat Kv1.3 channels. The disulphide bridge pattern was studied by (1) limited reduction-alkylation at acidic pH and (2) enzymic cleavage on an immobilized trypsin cartridge, both followed by mass and sequence analyses. Three of the disulphide bonds are connected as in the three-disulphide-bridged scorpion toxins, and the two extra half-cystine residues of HsTX1 are cross-linked, as in Pi1. These results, together with those of CD analysis, suggest that HsTX1 probably adopts the same general folding as all scorpion K+ channel toxins. HsTX1 is a potent inhibitor of the rat Kv1.3 channels (IC50 approx. 12 pM). HsTX1 does not compete with 125I-apamin for binding to its receptor site on rat brain synaptosomal membranes, but competes efficiently with 125I-kaliotoxin for binding to the voltage-gated K+ channels on the same preparation (IC50 approx. 1 pM).

[A molecular epidemiological analysis of several outbreaks of tuberculosis in public saunas. A problem of tuberculosis among homeless people in the metropolitan area]

There were several outbreaks of pulmonary tuberculosis among employees and customers of public saunas in Shijuku, a large office, shopping and amusement quarter in Tokyo. Twenty four patients with pulmonary tuberculosis were found between March 1994 and November 1996. Restriction fragment length polymorphism analysis of DNA derived from Mycobacterium tuberculosis isolated from eighteen patients with positive cultures was used to analyze the transmission route. The DNA probe was derived from the insertion sequence IS6110. There were 14 different DNA patterns of the M. tuberculosis isolated from 18 patients. Of 14 patterns, three patterns were shared by 2 patients, patients and 3 patients, respectively. The remaining 11 patterns were observed in 11 patients, thus one pattern for each patient. These data suggest that the infection of M. tuberculosis resulted from different origins. The saunas in amusement areas like Shinjuku have been used as hotels. Many customers from different places are using the saunas for overnight stay, and in particular homeless people have been using the saunas as their "home". The sauna can be a place where groups of people with high risk for tuberculosis congregate and the potential for an outbreak of tuberculosis can occur.

Fluorescent estimation on cytotoxicity of methylmercury in dissociated rat cerebellar neurons: its comparison with ionomycin

To study the cellular basis of the neurotoxicity of methylmercury, the effects of methylmercury on dissociated rat cerebellar neurons were examined using a flow cytometer, a confocal laser microscope and three fluorescent dyes, fluo-3 for monitoring the changes in intracellular Ca(2+) concentration ([Ca(2+)](i)) and for detecting live neurons, ethidium for assessing the neurons that are dead or have compromised membranes, and 5-chloromethylfluorescein (CMF) for estimating the cellular content of nonprotein thiols. Methylmercury at concentrations of 1 μM or greater increased the [Ca(2+)](i) of almost all neurons. Prolonged exposure to methylmercury (3 and 10 μM) produced a further increase in [Ca(2+)](i), in association with compromising membranes in some neurons. Thereafter, methylmercury induced blebs on membranes of some neurons with increased [Ca(2+)](i). Methylmercury at concentrations of 0.3 μM or greater dose-dependently decreased the cellular content of nonprotein thiols. Results suggest that methylmercury may induce the loss of membrane integrity through destabilized Ca(2+) homeostasis and oxidative stress in mammalian brain neurons.

5,6-Cis-penems: broad-spectrum anti-methicillin-resistant Staphylococcus aureus beta-lactam antibiotics

5,6-cis-Penem derivatives have been synthesized and evaluated as anti-MRSA antibiotics. The cis-penems 5 and 6 showed potent activities against not only MRSA but also a wide variety of bacteria including beta-lactamase-producing microorganisms. These compounds were designed to have high affinity to the penicillin-binding protein 2a of MRSA and to form stable acyl intermediates with beta-lactamases by blocking the deacylating water molecule.

Structure-activity relationships of penem antibiotics: crystallographic structures and implications for their antimicrobial activities

Twelve closely related crystal structures of the penem derivatives revealed a characteristic short contact of the oxygen atom in the C2 side-chains with the S1 atom. The side-chain conformations of the crystal structures showed a good correlation with the antimicrobial activity. In particular, the penems which show high antimicrobial activity have similar torsion angles for S1-C2-C1'-C2', suggesting that the disposition of the C2' atom would be important for binding to penicillin-interacting enzymes. Two conformations of the C6 hydroxyethyl group were observed in the crystal structures. Of those two, the conformation with a larger torsion angle (delta = 179.2 degrees) is deduced to be the enzyme-bound conformation in the Michaelis complex.

Flow-cytometric analysis on kainate-induced decrease in the cellular content of non-protein thiols in dissociated rat brain neurons

In order to study the kainate-induced oxidative stress on brain neurons, the effect of kainate on cellular content of glutathione in rat cerebellar neurons were examined using a flow cytometer and 5-chloromethylfluorescein, a fluorescent dye for cellular non-protein thiols (mainly glutathione). Kainate at concentrations ranging from 30 microM to 1 mM produced a dose-dependent decrease in cellular content of glutathione. Exposure of neurons to kainate at concentrations of 300 microM or greater seemed to deplete cellular glutathione. Potency of kainate in reducing cellular content of glutathione was greater than those of glutamate and N-methyl-D-aspartate (NMDA). Kainate-induced decrease in cellular content of glutathione was partly attenuated by 6-nitro-7-cyano-quinoxaline-2,3-dione, a blocker of non-NMDA receptors and removal of external Ca2+. Results indicate that kainate causes Ca2(+)-dependent oxidative stress that decreases the cellular content of glutathione via activation of non-NMDA type of glutamate receptors.

[HIV/AIDS counseling services for foreigners at the Shinjuku Public Health Center]

Since October 1994, the Shinjuku Public Health Center in collaboration with an NGO, has offered AIDS counseling services for foreigners. Although the NGO operated with volunteers before July 1995, the Center began budgeted HIV/AIDS counseling for foreigners from July 1995. The pre-HIV test counseling and post-test counseling sessions were held twice a month, in English, Thai, Spanish and Portuguese. Counselors who speak those languages worked in coordination with staff members of the Center. Starting July 1995, counseling by telephone was also offered. During the 1 1/2 years, from October 1994 to March 1996, 600 people visited the Center for HIV tests and AIDS counseling, of whom 103 (17%) were foreigners. Among the 103 foreigners, one person was detected as seropositive. The 103 foreigners included 56 Thai speakers, 20 English speakers, 8 Portuguese speakers, 7 Spanish speakers and 12 people who speak other native languages (Chinese, Korean, Burmese, Iranian). From July 1995 to March 1996, (about 8 months), 39 foreigners utilized the telephoned service for HIV test information: these 39 included 5 seropositive persons and AIDS patients. The number of foreigners visiting the Center for AIDS counseling and the number of foreigners utilizing the telephone service has increased each year. It is expected that the demand for these services will increase continuously in future.

[Energy spectral analysis in a photopeak region of 201Hg X-rays for 201Tl imaging]

For thallium-201 (201Tl) imaging, a photopeak of X-ray region of mercury-201 (201Hg) around 70 keV is usually employed. In such a low energy region, scatter and attenuation in the body become serious problems for quantitative scintigraphic imaging. We measured energy spectra around 201Hg X-ray region by a 201Tl line source with scattering materials and a gamma camera, and analyzed them to investigate the amount of scattered photons in 201Tl imaging window. Furthermore, Monte Carlo calculations were performed to distinguish primary photons from scattered photons. The results of analysis of energy spectra showed that the 201Hg X-ray photopeak consists of four different X-rays and do not have a perfect Gaussian shape. It was also found that not only forward scatter but also much backward scatter are included in this region. These scattered photons were reduced by using an off-peak window moved toward the higher energy region. We conclude that the data obtained from the analysis of scattered photons in 201Tl imaging window are very useful to develop a new scatter correction method and evaluate the scatter rejection methods proposed.

Conversion of inactive glycosylation inhibiting factor to bioactive derivatives by modification of a SH group

Escherichia coli-derived recombinant human glycosylation inhibiting factor (rhGIF) contains three cysteine residues (Cys-57, -60, and -81). All SH groups in the cysteine residues are free, and the GIF molecule had no biologic activity. Carboxymethylation of the SH group of Cys-60 in the molecule resulted in the generation of bioactivity, although the activity of the carboxymethylated GIF was 10- to 20-fold less than that of suppressor T cell (Ts)-derived GIF. However, treatment of the inactive rhGIF with ethylmercurithiosalicylate or 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) resulted in the generation of derivatives whose bioactivity was comparable to that of the Ts-derived bioactive GIF. The activity of these derivatives was lost by treatment with DTT. Isolation and chemical analysis of the DTNB-treated GIF derivative revealed that binding the 5-thio-2-nitrobenzoic acid group with Cys-60 was responsible for the generation of the highly bioactive derivative. Inactive cytosolic GIF from mammalian cells could also be converted to bioactive derivative by treatment with the SH reagent, while Ts-derived bioactive GIF was inactivated by DTT. These results, together with an x-ray crystal structure of GIF molecules, strongly suggest that the generation of bioactivity of GIF in Ts cells is due to posttranslational modifications that result in conformational changes in the molecule.

Presence of Ca(2+)-sensitive and -insensitive SM22 alpha isoproteins in bovine aorta

Two proteins (25- and 22-kDa) that cross-react with anti-gizzard SM22 alpha antibody were isolated from bovine aorta. The former, identical to a SM22 alpha homolog reported previously (Kobayashi, R., Kubota, T., and Hidaka, H. (1994) Biochem. Biophys. Res. Commun. 198, 1275-1280), associates with the membrane fraction in the presence of Ca2+ and dissociates in the presence of EGTA, while the latter is insensitive to Ca2+. Peptide mapping and partial sequence analysis revealed that the 22-kDa protein is an isoform of the 25-kDa protein, without 22 amino acid residues from the C-terminus. Immunological analysis of the tissue distribution of these proteins showed that the 25-kDa protein exists in lung and spleen besides aorta, while the 22-kDa protein occurs specifically in the aorta and spleen.

Oxidative stress-induced increase in intracellular Ca2+ and Ca(2+)-induced increase in oxidative stress: an experimental model using dissociated rat brain neurons

In order to study the oxidative stress-induced change in intracellular concentration of Ca2+ ([Ca2+]i) and Ca(2+)-induced oxidative stress, effects of hydrogen peroxide and ionomycin, a calcium ionophore, on rat cerebellar neurons were examined using a flow cytometer and fluorescent dyes: fluo-3 for monitoring [Ca2+]i; 2',7'-dichlorofluorescin, for reactive oxygen species; and 5-chloromethylfluorescein, for cellular nonprotein thiols. Oxidative stress induced by hydrogen peroxide dose-dependently increased [Ca2+]i and decreased the content of nonprotein thiols. Ionomycin increased oxidative metabolism and decreased the content of nonprotein thiols. Results suggest that oxidative stress induces an increase in [Ca2+]i while an increase in [Ca2+]i increases oxidative stress in neurons.

[Evaluation of simultaneous acquisition of transmission and emission data on thallium-201 myocardial SPECT]

This study evaluates the usefulness of attenuation correction on regional myocardial tracer distributions defined by Thallium-201 myocardial SPECT images obtained from cardiac phantoms and patients with or without coronary heart disease. A three-detector SPECT system equipped with a Technetium-99m line source and a fan-beam collimator was used for simultaneous transmission and emission data acquisition. All three detectors were equipped with fan-beam collimators. Thallium-201 myocardial scintigraphy was performed on phantom study and 19 patients. Transmission images, uncorrected and corrected emission images were iteratively reconstructed with a EM-ML algorithm. Attenuation map computed from the transmission data was utilized for the attenuation correction. For the phantom study, circumferential profile analysis was applied to both datasets of horizontal long-axis slices through the center of the phantom. The maximum profile value in the circumferential profile set to 100% in the normalized uncorrected and corrected profiles. The uncorrected circumferential profiles from cardiac insert model 7070 and RH-2 cardiophantom showed decrease in activity in basal regions which appeared improvement in the attenuation corrected profiles. In clinical study, the inferior-to-anterior activity ratio, changed from 0.78 +/- 0.10 to 0.97 +/- 0.11 on stress images in patients with inferior ischemia and from 0.96 +/- 0.12 to 1.15 +/- 0.13 on 4 hour delayed or rest images in normal cases. The anteroapical wall of the attenuation corrected images, however, showed a decrease in activity relative to the inferior wall in normal cases. The increase in activity in inferior wall on attenuation corrected images was observed frequently in clinical study but not in phantom study. A presence of scatter from the liver or bowels may cause the increase in activity in the inferior wall in clinical study. In conclusion, transmission scan is one of the useful methods for the attenuation correction. Scatter correction, however, is also necessary to make an accurate attenuation corrected images.

Fluorescent estimation of H2O2-induced changes in cell viability and cellular nonprotein thiol level of dissociated rat thymocytes

We have developed a procedure to simultaneously estimate cell viability and the cellular level of nonprotein thiol (presumably glutathione) using two fluorescent dyes, 5-chloromethylfluorescein (5CMF) and ethidium, and rat thymocytes. Diethylmaleate and N-ethylmaleimide reduced, respectively, the intensity of 5CMF fluorescence to 0.23 and 0.1, relative to the control. Incubation with buthionine sulfoximine, an inhibitor of glutathione synthesis, decreased the intensity of 5CMF fluorescence to 0.61. Results indicate that 5CMF fluorescence can be attenuated by agents that decrease the level of cellular nonprotein thiols, suggesting that 5CMF fluorescence is utilized for estimating the level of cellular glutathione. Hydrogen peroxide (10 microM to 3 mM) reduced the intensity of 5CMF fluorescence in a dose-dependent manner and increased the number of thymocytes stained with ethidium (presumably dead cells or cells with compromised membranes) at concentrations of 300 microM or greater. Reduction of cellular glutathione level seems to precede cell death in which oxidative stress is involved.

Flow cytometric analysis of the H2O2-induced increase in intracellular Ca2+ concentration of rat thymocytes

The effect of hydrogen peroxide (H2O2) on the intracellular Ca2+ concentration ([Ca2+]i) of rat thymocytes was examined by a flow cytometer and two fluorescent dyes, fluo-3-AM and ethidium bromide, a dye impermeant to intact membranes, to characterize the H2O2-induced increase in [Ca2+]i. H2O2 at concentrations greater than 30 microM dose-dependently increased the [Ca2+]i of thymocytes which were not stained with ethidium. Removal of external Ca2+ greatly reduced the degree of H2O2-induced increase in [Ca2+]i. However, H2O2 still increased the [Ca2+]i under the external Ca(2+)-free condition. Diethylmaleate, which is known to produce a chemical depletion of cellular nonprotein thiol, significantly increased the [Ca2+]i. Dithiothreitol, which is used to protect cellular nonprotein thiol, slightly decreased the [Ca2+]i, but greatly reduced the H2O2-induced increase in [Ca2+]i. Therefore, it is considered that H2O2 may increase the [Ca2+]i through a mechanism related to the effects of H2O2 on the cellular nonprotein thiol.

Flow-cytometric estimation on glutamate- and kainate-induced increases in intracellular Ca2+ of brain neurons: a technical aspect

Effects of glutamate and kainate on the intracellular Ca2+ concentration ([Ca2+]i) in a large population (several thousand) of dissociated cerebellar granule cell neurons were evaluated using a flow-cytometer and a combination of two fluorescent dyes, fluo-3-AM for estimating [Ca2+]i and ethidium bromide for removing neurons that had compromised membranes from the cell population examined. The number of neurons responding to glutamate or kainate in augmenting the fluo-3 fluorescence increased in a dose-dependent manner. The number of neurons responding to kainate was much greater than that to glutamate. CNQX, a blocker of non-NMDA receptors, completely blocked the response elicited by kainate while the complete blockade of this glutamate-induced response was made by a combination of MK-801, a NMDA receptor blocker, and CNQX. Nicardipine, a calcium antagonist, decreased the number of neurons responding to glutamate and kainate, suggesting involvement of voltage-dependent calcium channels. These results indicate that the flow-cytometric measurement of glutamate and kainate responses has the potential to provide answers to such questions as what percentage of the population of neurons respond to these amino acids and what is the resulting distribution of [Ca2+]i.

Clinicopathological analysis and therapy in hepatitis C virus-associated nephropathy

We analyzed the clinicopathological features and therapy in 19 patients with kidney disease accompanied by hepatitis C viral infection, including 12 patients with mesangial proliferative glomerulonephritis (including eight with IgA nephropathy), six with membranoproliferative glomerulonephritis (MPGN), and one with membranous nephropathy. Persistent hematuria and/ or proteinuria (10 patients) was the most common finding, followed by nephrotic syndrome (8 patients). Cryoglobulinemia was detected in six of 19 patients examined (four of six patients with MPGN). Analysis of hepatitis C virus (HCV)-RNA genotype in 13 patients revealed that nine of them had type II genotype. All four patients with MPGN, who had serum positive for HCV-RNA, had type II genotype. Five patients were treated with interferon-alpha (IFN-alpha) without a demonstrable effect on renal impairment, whereas five of 11 patients treated with steroids showed improvement of the renal impairment. During the course of steroid therapy, the serum titer of HCV-RNA decreased in 5 of 7 patients. These observations suggest that HCV infection may be associated with several forms of glomerulonephritis. Type II HCV-RNA may have a strong association with MPGN in Japan. Steroid therapy is not contraindicated in patients with HCV-associated nephropathy if they are resistant to IFN-alpha treatment.

Late onset bone marrow transplant nephropathy

We report a patient who exhibited proteinuria and renal failure 93 months after receiving an allogeneic bone marrow transplantation (BMT) from his HLA-identical brother. A renal biopsy specimen revealed segmental sclerosis, mesangiolysis, subendothelial lucency in the glomeruli, fibrosis and small round cell infiltration in the interstitium, and hyaline droplets in the intimal spaces of arterioles and small arteries. These histological findings were consistent with late onset BMT nephropathy. This nephropathy may represent a more serious problem in the near future in Japan, since the number of BMT performed has been increasing with the establishment of a bone marrow bank.

Cytotoxic action of tri-n-butyltin on dissociated rat cerebellar neurones: a flow-cytometric study

The effects of tri-n-butyltin on cell viability and intracellular Ca2+ concentration ([CA2+]i) were examined by a flow cytometer in rat cerebellar neurones to reveal the contribution of tri-n-butyltin-induced increased in the [Ca2+]i to its cytotoxicity. Tri-n-Butyltin decreased the cell viability in association with increased [Ca2+]i at concentrations of 0.3 microM or more. Decrease or increase of the extracellular Ca2+ concentration ([Ca2+]o) respectively decreased or increased the cell viability. However, cell viability in the presence of ionomycin which increased [Ca2+]i more significantly than tri-n-butyltin was higher than that in the presence of tri-n-butyltin. Tri-n-butyltin also decreased cell viability under nominally [Ca2+]o-free conditions although the [Ca2+]i increase by tri-n-butyltin was still lower than the control [Ca2+]i under normal [Ca2+]o (2 mM). Therefore, it is unlikely that neuronal death induced by tri-n-butyltin is entirely dependent on the tri-n-butyltin-induced increase in [Ca2+]i.

Ginkgo biloba extract protects brain neurons against oxidative stress induced by hydrogen peroxide

Effect of Ginkgo biloba extract was examined on dissociated rat cerebellar neurons suffering from oxidative stress induced by hydrogen peroxide using a flow cytometer and ethidium bromide. Hydrogen peroxide at a concentration of 3 mM increased the number of neurons stained with ethidium (presumably dead neurons) in a time-dependent manner. Pretreatment of neurons with G. biloba extract (10 micrograms/ml) greatly delayed a time-dependent increase in number of dead neurons during exposure to hydrogen peroxide. It was true, but less effective, in the case of treatment with G. biloba extract immediately or 60 min after start of oxidative stress. Results implicate G. biloba extract as a potential agent in protecting the neurons suffering from oxidative stress induced by hydrogen peroxide.

Postcolumn co-immobilized leucine dehydrogenase-NADH oxidase reactor for the determination of branched-chain amino acids by high-performance liquid chromatography with chemiluminescence detection

A liquid chromatographic system with a co-immobilized leucine dehydrogenase-NADH oxidase reactor is described for the determination of branched-chain amino acids such as I-leucine, I-isoleucine and I-valine. The enzymes were simultaneously immobilized on tresylate-containing poly(vinyl alcohol) beads. The separation was achieved by means of an ODS column with elution with phosphate buffer (pH 7.5). The hydrogen peroxide produced was detected chemiluminometrically via a luminol-hexacyanoferrate(III) reaction. The system gave a linear response from 0.3 to 300 mu M for each amino acid and the detection limit was 0.1 mu M.

[Isolated angiitis of the central nervous system presenting as subcortical hemorrhage--a case report of benign type]

A 47-year-old woman had an episode of severe headache for a few days. She suddenly experienced right leg weakness and sensory loss. A CT scan revealed subcortical hematoma at the left parietal lobe on admission. Cerebral angiography showed multiple vascular irregularities such as segmentally narrow or sausage-like dialatated areas. Her laboratory studies were entirely normal including antinuclear antibody and coagulation tests. The diagnosis of isolated angiitis of the CNS was made and she responded well to the low dose corticosteroid therapy. Repeated cerebral angiography two months after the onset demonstrated most of the areas of segmental irregularity had improved with a few unchanged areas. Some cerebral angiitis do exist that respond well to corticosteroid therapy, therefore, early diagnosis and treatment are suggested in cases of angiitis.