Inhibition with N-acetylcysteine of enhanced production of tumor necrosis factor in streptozotocin-induced diabetic rats

We previously reported that the in vivo production of the tumor necrosis factor alpha (TNF) was significantly enhanced after the onset of diabetes in spontaneous type 1 and 2 diabetic animals. In this report we confirmed the enhanced production of TNF in streptozotocin (STZ)-induced diabetes and then attempted to suppress the enhanced TNF production with N-acetylcysteine (NAC), a precursor of glutathione synthesis. The lipopolysaccharide-induced serum TNF activities were significantly enhanced in STZ-induced diabetic rats (6-18 weeks of age) compared with those of nondiabetic rats throughout the 12-week experiment. A single, oral administration of NAC (200 or 1000 mg/kg body wt) significantly suppressed the enhanced TNF production in the diabetic rats compared with that in untreated rats in a dose-dependent manner. On the other hand, in the long-term (6 or 12 weeks) administrations, smaller doses of NAC (50 or 200 mg/kg/day) also significantly inhibited the enhanced production of TNF regardless of the dose of NAC. NAC administration, however, did not suppress the TNF production of nondiabetic rats. The long-term NAC administration affected neither body weight nor levels of serum glucose, fructosamine, albumin, and triglyceride. These results show that NAC administration significantly suppressed the enhanced TNF production in diabetic rats and indicate that NAC might be useful in preventing TNF-mediated pathological conditions in diabetes.

Pharmacological profile of the novel, potent and selective peptide leukotriene antagonist (E)-2,2-diethyl-3'-[2-[2-(4-isopropyl)thiazolyl]ethenyl]succinanilic acid

In this report, the in vitro and in vivo pharmacological profile of MCI-826 ((E)-2,2-diethyl-3'-[2-[2-(4-isopropyl) thiazolyl]ethenyl]succinanilic acid, CAS 121230-22-6) is described. In isolated guinea pig ileum, MCI-826 inhibited LTD4 (a peptide leukotriene, 10(-9) mol/l)-induced contraction in a concentration-dependent manner with an IC50 of 6.8 x 10(-12) mol/l. It had no effect on histamine (10(-5) mol/l)-, serotonin (2.5 x 10(-5) mol/l)-, or acetylcholine (5.5 x 10(-6) mol/l)- induced contractions in isolated guinea pig ileum. In isolated guinea pig trachea, MCI-826 demonstrated competitive antagonism of the contractile activity of LTD4 and LTE4 with pA2 values of 9.0 and 8.8, respectively. MCI-826 inhibited LTC4-induced contraction in a concentration-dependent manner. However, in the presence of an inhibitor of the metabolism of LTC4 to LTD4, MCI-826 (10(-6) mol/l) produced no effect on LTC4 concentration-response curves in guinea pig trachea. In the in vivo study, the oral administration of MCI-826 caused a dose-dependent inhibition of LTC4- and LTD4-induced bronchoconstrictions in guinea pigs with an ED50 of 0.049 and 0.013 mg/kg, respectively. However, MCI-826 (3 mg/kg p.o.) showed no effect on histamine-induced bronchoconstriction in guinea pigs. The pharmacological half-life of orally administered MCI-826 as assessed by LTD4-induced bronchoconstriction was more than 12 h in guinea pigs. MCI-826 also inhibited antigen-induced bronchoconstriction in a dose-dependent manner with a MID (minimum dose that causes significant inhibition) of 0.1 mg/kg p.o. in guinea pigs.(ABSTRACT TRUNCATED AT 250 WORDS)

Platelet superoxide dismutase in migraine and tension-type headache

Superoxide dismutase (SOD) is a radical-scavenging enzyme. We determined Cu, Zn-SOD concentrations and activities in platelets from subjects with migraine and tension-type headaches. Thirty migraine without aura (MWoA) patients, 9 migraine with aura (MWA) patients, and 53 tension-type headache patients were selected for study. Thirty healthy volunteers composed the control group. Concentrations of platelet SOD were determined using enzyme-linked immunosorbent assay techniques. The activity of platelet SOD was determined by measuring reductivity of nitroblue tetrazolium. Low concentrations of platelet SOD were found in patients with MWA and MWoA. Platelet SOD activity decreased in MWA patients but not in patients with MWoA or tension-type headaches. These findings suggest vulnerability to oxidative stress in patients with migraine. It is suggested that low platelet SOD levels may play an important role in the etiology of migraine.

Cellular markers that distinguish the phases of hemangioma during infancy and childhood

Hemangiomas, localized tumors of blood vessels, appear in approximately 10-12% of Caucasian infants. These lesions are characterized by a rapid proliferation of capillaries for the first year (proliferating phase), followed by slow, inevitable, regression of the tumor over the ensuing 1-5 yr (involuting phase), and continual improvement until 6-12 yr of age (involuted phase). To delineate the clinically observed growth phases of hemangiomas at a cellular level, we undertook an immunohistochemical analysis using nine independent markers. The proliferating phase was defined by high expression of proliferating cell nuclear antigen, type IV collagenase, and vascular endothelial growth factor. Elevated expression of the tissue inhibitor of metalloproteinase, TIMP 1, an inhibitor of new blood vessel formation, was observed exclusively in the involuting phase. High expression of basic fibroblast growth factor (bFGF) and urokinase was present in the proliferating and involuting phases. There was coexpression of bFGF and endothelial phenotypic markers CD31 and von Willebrand factor in the proliferating phase. These results provide an objective basis for staging hemangiomas and may be used to evaluate pharmacological agents, such as corticosteroids and interferon alfa-2a, which accelerate regression of hemangiomas. By contrast, vascular malformations do not express proliferating cell nuclear antigen, vascular endothelial growth factor, bFGF, type IV collagenase, and urokinase. These data demonstrate immunohistochemical differences between proliferating hemangiomas and vascular malformations which reflect the biological distinctions between these vascular lesions.

Effects of the altered serotonergic signalling by neonatal treatment with 5,7-dihydroxytryptamine, ritanserin or clomipramine on the adrenocortical stress response and the glucocorticoid receptor binding in the hippocampus in adult rats

The aim of the present study is to investigate the effect of neonatal alterations in 5-HT signalling on the regulation of endocrine stress response in adult rats. The neonatal blockade of 5-HT transmission by 5,7-DHT or ritanserin treatment did not alter the density of glucocorticoid receptor (GR) binding sites in the hippocampus, although a 5,7-DHT-induced lesion was clearly shown to decrease in 5-HT content by greater than 80% in the hippocampus. In addition, the animals pretreated with the blockade of 5-HT transmission during early life did not exhibit a hyperresponsiveness of the adrenocortical response to stress. On the other hand, the neonatal administration of the 5-HT uptake inhibitor, clomipramine, was shown to lower the stress responsiveness of the adrenocortical axis in adulthood.

Development of hepatic microsomal mixed function oxidase system in male broilers fed a high or low protein diet

This experiment was undertaken to determine the changes in the mixed function oxidase system (MFO) in hepatic microsomes of male broiler chicks fed a 15% crude protein (LP) or 23% crude protein (HP) diet at different ages. The cytochromes P-450 and b5 content per unit of microsomal protein increased with age, while those per unit of body weight reached a maximum at 6 weeks of age, regardless of dietary protein levels. The activity of the MFO in chicks fed the HP diet was greater than those in chicks fed the LP diet during the first 9 weeks after hatching. At 4 weeks of age, cytochromes P-450 and b5, and NADPH-cytochrome c reductase were reduced by feeding the HP diet, but not by the LP diet.

[An evaluation study on arbekacin for MRSA-infectious diseases including pneumonia, septicemia and others]

Availability of arbekacin (ABK) was analyzed in the chemotherapy of 24 MRSA-infected patients with symptoms of pneumonia (12), sepsis (6) and others (6). Most patients had background diseases such as malignant tumors or cerebrovascular disorders. 47% (7/15) of them were immunologically abnormal. 17 of them had been previously treated with cephems, imipenem, minocycline or fosfomycin. The ABK therapy was performed with doses ranging 50-400 mg a day, divided into 1-3 times (mostly 100 mg x 2), and for 5-24 days. (18 patients were treated between 5 and 14 days). 14 patients (58%) received combined therapy with other antibiotics (mostly with beta-lactams, 12). The clinical efficacy rate of the ABK therapy was 62% (good, 13; fair, 4; ineffective, 4; unknown, 3). The bacteriological efficacies were: eradicated, 7 (44%); decreased, 4; no change, 5; unknown, 8. Side effects were found in 3 patients (oliguria, 2; eruption due to drug, 1) and one case resulted in serious renal disorder. Abnormal laboratory data were found in 7 cases. Above results have indicated that ABK is a useful antibiotic in chemotherapy of MRSA-infections.

Stereoselective antagonism by enantiomers of alanine and serine of phencyclidine-induced hyperactivity, stereotypy and ataxia in the rat

Intracerebroventricular injection of the D-forms of alanine (Ala; 2-200 micrograms/rat) and serine (Ser; 20-2000 micrograms/rat) caused a dose-dependent inhibition of the ability of 10 mg/kg of phencyclidine (PCP; given i.p.) to increase automatically quantitated locomotor counts and cumulated scores of locomotion, stereotypy and ataxia for 90 min after PCP administration. D-Ala and D-Ser were found to be more potent than the corresponding L-isomers in attenuating the PCP-induction of these behavioral abnormalities. Although L-, but not D-Ser, at moderate doses (400 micrograms/rat) produced a slight decrease in cumulative ataxia scores after a 10-mg/kg PCP administration, D-, but not L-Ser, reduced the behavioral scores at large doses (more than 1000 micrograms/rat). Similarly, bilateral i.c.v. infusion of D-Ala (140 micrograms/rat) reduced the increasing effects of a lower dose of PCP (5 mg/kg i.p.) on locomotion, stereotypy and ataxia scores, whereas the L-form of Ala (140 micrograms/rat) lacked the inhibitory influence. The stereo-selectivity of the antagonism by Ala and Ser of PCP-induced abnormal behavior parallels that of the potencies of these amino acids as agonists for the strychnine-insensitive glycine site linked to the N-methyl-D-aspartate type excitatory amino acid receptor. Furthermore, the decreasing effects of D-Ala (200 micrograms/rat i.c.v.) and D-Ser (2000 micrograms/rat i.c.v.) on PCP-induced hyperactivity were antagonized by i.c.v. application of 5,7-dichlorokynurenate and 7-chlorokynurenate which are selective antagonists of the glycine modulatory site.(ABSTRACT TRUNCATED AT 250 WORDS)

The role of macrophage colony-stimulating factor in hepatic glucan-induced granuloma formation in the osteopetrosis mutant mouse defective in the production of macrophage colony-stimulating factor

To elucidate the effects of macrophage colony-stimulating factor (M-CSF) on Kupffer cells and monocyte/macrophages in hepatic granuloma formation, we examined granulomas produced by glucan injection in the liver of osteopetrotic mice and littermates with or without M-CSF administration. In the osteopetrotic mice, monocytes were deficient in peripheral blood, and their number did not increase after glucan injection. Hepatic granulomas were formed in the osteopetrotic mice by glucan injection without a supply of blood monocytes. During this process, M-CSF-independent Kupffer cells proliferated, particularly before the granuloma formation, clustered in the hepatic sinusoid, and transformed into epithelioid cells and multinuclear giant cells. In the M-CSF-treated osteopetrotic mice, glucan injection induced an increase in the number of blood monocytes and formed hepatic granulomas at a nearly similar degree to that of littermate mice. Thus, it is concluded that neither monocytes nor M-CSF are necessary for granuloma formation. In contrast, Kupffer cells play a crucial role as granulomas develop in M-CSF-uninjected osteopetrotic mice.

Reversible white matter lesions in a patient with fulminant hepatitis and acute renal failure

A 36-year-old man developed fulminant hepatitis and acute renal failure with profound hyponatremia (116 mEq/L). Emergent hemodialysis corrected the serum sodium to 136 mEq/L within 24 hours. He developed generalized convulsions 11 days later. Magnetic resonance imaging (MRI) revealed a single large symmetrical lesion in the pons and extensive white matter lesions in the bilateral occipital, temporal, parietal and right frontal regions. These lesions showed marked resolution as the patient recovered. Fulminant hepatitis and acute renal failure could induce extensive edema in the cerebral white matter. Therefore, not all MRI abnormalities in the white matter after correction of hyponatremia necessarily reflect myelinolysis.

Regulation of recombinant human granulocyte colony-stimulation factor production using herpes simplex virus 1 thymidine kinase gene

For chronic neutropenic patients requiring long-term injection of recombinant human granulocyte colony-stimulating factor (rhG-CSF), a cellular transplantation system that can produce this cytokine stably and deliver it in a regulatory manner would be advantageous. In this study we aimed at developing a regulation system at cellular level using suicide vectors. We introduced the herpes simplex virus type 1 thymidine kinase (HSV-TK) gene into the rhG-CSF-producing NIH3T3 cells and examined if ganciclovir (GCV) treatment of the cells could control the rhG-CSF production in vitro. The cells transfected with the HSV-TK gene showed a > 100-fold increase in sensitivity to GCV compared with the parent cells, and the median inhibitory dose of GCV to the transfected cells was less than 1.6 microM. The total amount of rhG-CSF production by these cells was strongly suppressed by GCV treatment. This regulatory method may be applicable to cytokine supplement gene therapy.

Effects of changing glutamate 487 to lysine in rat and human liver mitochondrial aldehyde dehydrogenase. A model to study human (Oriental type) class 2 aldehyde dehydrogenase

Many Oriental people possess a liver mitochondrial aldehyde dehydrogenase where glutamate at position 487 has been replaced by a lysine, and they have very low levels of mitochondrial aldehyde dehydrogenase activity. To investigate the cause of the lack of activity of this aldehyde dehydrogenase, we mutated residue 487 of rat and human liver mitochondrial aldehyde dehydrogenase to a lysine and expressed the mutant and native enzyme forms in Escherichia coli. Both rat and human recombinant aldehyde dehydrogenases showed the same molecular and kinetic properties as the enzyme isolated from liver mitochondria. The E487K mutants were found to be active but possessed altered kinetic properties when compared to the glutamate enzyme. The Km for NAD+ at pH 7.4 increased more than 150-fold, whereas kcat decreased 2-10-fold with respect to the recombinant native enzymes. Detailed steady-state kinetic analysis showed that the binding of NAD+ to the mutant enzyme was impaired, and it could be calculated that this resulted in a decreased nucleophilicity of the active site cysteine residue. The rate-limiting step for the rat E487K mutant was also different from that of the recombinant rat liver aldehyde dehydrogenase in that no pre-steady-state burst of NADH formation was found with the mutant enzyme. Both the rat native enzyme and the E487K mutant oxidized chloroacetaldehyde twice as fast as acetaldehyde, indicating that the rate-limiting step was not hydride transfer or coenzyme dissociation but depended upon nucleophilic attack. Each enzyme form showed a 2-fold activation upon the addition of Mg2+ ions. Substituting a glutamine for the glutamate did not grossly affect the properties of the enzyme. Glutamate 487 may interact directly with the positive nicotinamide ring of NAD+ for the Ki of NADH was the same in the lysine enzyme as it was in the glutamate form. Because of the altered NAD+ binding properties and kcat of the E487K variant, it is assumed that people possessing this form will not have a functional mitochondrial aldehyde dehydrogenase.

Radiofrequency current catheter ablation for ventricular tachycardia

Radiofrequency current catheter ablation was attempted for 17 morphologies of ventricular tachycardia (VT) in 14 patients. Five patients had underlying heart disease. The site of VT origin was determined as the earliest site of ventricular activation, or by pacing within the area of slow conduction. In 15 VTs, ablation was performed during VT, and 12 VTs (80%) were terminated within an average of 5.4 +/- 4.2 seconds. After ablation, 14 VTs (14/17 = 82%) of 11 patients (11/14 = 79%) could not be induced by electrical stimulation. Radiofrequency ablation appeared to be more effective in VTs without underlying heart disease (91%), and in VTs originating from the right ventricle (100%). Successful ablation sites usually showed a normal local electrograms during VT. Ablation in the slow conduction area was attempted in 3 VTs, and 2 VTs became noninducible. The mean number of applications of radiofrequency current for each VT origin was 7.7 +/- 6.4 at 20-50 Watts. In 4 patients, application of radiofrequency current was required 10 or more times because of a possible large arrhythmogenic area, or because of reinduction of VT, even though VT was terminated by radiofrequency current. No major complication was observed except for complete right bundle branch block in 1 patient.

IN CONCLUSION

(1) Radiofrequency catheter ablation was considered to be effective and safe, especially for VT without underlying heart disease or VT originating from the right ventricle. (2) Ablation during VT was considered to be useful for identifying the proper ablation site and to avoid creating an unnecessary lesion.

Possible involvement of central cholinergic system in ameliorating effects of indeloxazine, a cerebral activator, on disturbance of learning behavior in rats

Effects of indeloxazine, a cerebral activator, on passive avoidance learning by disruption of cholinergic transmission were studied in rats. The shortened latency was prolonged when indeloxazine was administered before training in rats subjected to scopolamine-injection, ethylcholine aziridinium ion (AF64A)-treatment and nucleus basalis magnocellularis (NBM) lesion. Indeloxazine administered immediately after training also showed ameliorating effects on passive avoidance in NBM-lesioned rats. Indeloxazine increased extracellular acetylcholine concentration in the frontal cortex of rats. Indeloxazine possesses facilitatory effects on cerebral function in part due to activation of the central cholinergic system.

Ultrasound transmission as a sensitive indicator of bone change in Japanese women in the perimenopausal period

Apparent velocity of ultrasound (AVU) through the patella was measured in 160 Japanese women without specific diseases affecting the skeletal system. AVU averaged 1955 +/- 64 m/s (mean +/- S.D.) in healthy premenopausal women. Twenty patients with postmenopausal osteoporosis over the age of 50 years with at least one atraumatic vertebral fracture had significantly lower average AVU (1757 +/- 89.6 m/s) than that of the same age group without compression fracture (1838 +/- 78.0 m/s, P < 0.05). Perimenopausal women without vertebral fracture in their 50s were divided into two groups, premenopausal (n = 11) and postmenopausal (n = 28), and both AVU through the patella and spinal BMD (L-2-4) using DXA were measured. A significant difference was found in AVU between the two groups (premenopausal, 1953 +/- 58 m/s; postmenopausal, 1885 +/- 73 m/s, P < 0.01), in the absence of a difference either in the mean age (premenopausal, 52.7 +/- 2.0; menopausal, 54.2 +/- 2.4) or in the spinal BMD as assessed by DXA (premenopausal, 0.930 +/- 0.080 g/cm2; postmenopausal, 0.851 +/- 0.148 g/cm2). The apparent difference in AVU without corresponding difference in BMD suggests that perhaps AVU measures something about the bone that is not reflected in BMD in women in their 50s in the immediate postmenopausal period. When AVU of our test subjects was compared with that in Caucasians reported by Heaney RP et al. (Osteoporotic bone fragility: detection by ultrasound transmission velocity. J Am Med Assoc 1989;261:2986-2990) no difference was found in AVU between Japanese and Caucasians.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of macrophage colony-stimulating factor (M-CSF) on the development, differentiation, and maturation of marginal metallophilic macrophages and marginal zone macrophages in the spleen of osteopetrosis (op) mutant mice lacking functional M-CSF activity

Immunohistochemical techniques using an anti-mouse panmacrophage monoclonal antibody and anti-mouse monoclonal antibodies specific for marginal metallophilic macrophages or marginal zone macrophages were used to detect red pulp macrophages, marginal metallophilic macrophages, and marginal zone macrophages in the spleen of op/op mice. In the mutant mice, the red pulp macrophages were reduced to about 60% of those in the normal littermates and the marginal metallophilic macrophages and marginal zone macrophages were absent. After administration of recombinant human macrophage colony-stimulating factor (rhM-CSF), numbers of red pulp macrophages increased rapidly, reaching levels found in normal littermates 1 week later. In contrast, the marginal metallophilic macrophages as well as the marginal zone macrophages appeared slowly after rhM-CSF administration and their numbers were less than half of the baseline level of normal littermates even at 12 weeks of administration. The distribution of marginal metallophilic macrophages and marginal zone macrophages appearing after M-CSF administration was irregular in the spleen of the op/op mice. These splenic macrophage subpopulations differed in their responses to rhM-CSF, suggesting that distinct mechanisms may be involved in their development and differentiation. The splenic red pulp macrophages present in unmanipulated op/op mice are an M-CSF-independent macrophage population. Although the marginal metallophilic macrophages and marginal zone macrophages are thought to be M-CSF-dependent, their development and differentiation appear to be influenced by locally produced M-CSF or other cytokines.

Immunophenotypic and ultrastructural heterogeneity of macrophage differentiation in bone marrow and fetal hematopoiesis of mouse in vitro and in vivo

The present in vitro study revealed marked differences in immunophenotypic expression and ultrastructure among macrophage colony-stimulating factor (M-CSF)-derived, granulocyte-macrophage colony-stimulating factor (GM-CSF)-derived, and multi-CSF-derived macrophages. M-CSF-derived macrophages were larger and had more markedly differentiated intracellular organelles and more cytoplasmic projections than GM-CSF-or multi-CSF-derived macrophages. By the combined method of ultrastructural peroxidase cytochemistry and immunoelectron microscopy, ER-MP12 was demonstrated mainly on blastic cells; ER-MP20 on promonocytes, monocytes, and immature macrophages; and F4/80 or BM8 on immature and mature macrophages and monocytes. Macrophage heterogeneity was demonstrated to occur at the stage of macrophage precursor cells, and macrophage differentiation was different between bone marrow hematopoiesis and early fetal hematopoiesis. In vivo, F4/80- or BM8-positive (+) macrophages and ER-MP12 (+) cells developed in the yolk sac prior to the appearance of ER-MP20 (+) monocytic cell series. These results imply that CSFs are important factors for the generation of phenotypic heterogeneity of macrophage populations not only in bone marrow but also in fetal hematopoiesis, suggesting that there are different pathways of macrophage differentiation.

Monocyte chemoattractant protein-1 in idiopathic pulmonary fibrosis and other interstitial lung diseases

Macrophages play a crucial role in the pathogenesis of idiopathic pulmonary fibrosis (IPF). To examine the mechanisms for increased monocyte/macrophage recruitment in IPF and nonIPF interstitial lung diseases (nonIPF) the localization of monocyte chemoattractant protein-1 (MCP-1) was investigated in 14 cases of IPF, seven cases of nonIPF, and seven normal control lungs (CTRL) by immunohistochemistry using a specific anti-MCP-1 monoclonal antibody, F9. By double immunohistochemical staining using F9 and one of the cell type specific antibodies significant differences in the staining pattern of MCP-1 were observed between IPF and nonIPF. In IPF MCP-1 was observed in cuboidal and flattened metaplastic epithelial cells, alveolar macrophages, and vascular endothelial cells. In contrast, no epithelial cells were stained for MCP-1 in nonIPF cases, although alveolar macrophages and vascular endothelial cells were labeled. Northern hybridization analysis of selected cases showed marked expression of MCP-1 messenger RNA (mRNA) in IPF and nonIPF compared with CTRL. These findings suggest that the MCP-1 production in IPF and nonIPF plays an important role in the recruitment of monocyte/macrophages. Monocyte chemoattractant protein-1 production by epithelial cells in IPF may be caused by the metaplastic nature of the epithelial cells and may be one of the key factors inducing the irreversible progression of IPF.

Current status of occupational health in Japan

In Japan, the primary administrative authority of occupational health is the Ministry of Labour, and its legislative basis is the Industrial Safety and Health Law (ISH law). Occupational health is mandated by this law and its enforcement involves the appointment of an occupational health physician (OP) for workplaces with 50 or more workers, and a full-time OP for workplaces with 1000 or more workers. The actual percentage of appointments filled for the former group is 83.4 per cent, compared with 58.4 per cent for the latter. The estimated number of OPs is 34000, of which 2000 work full time. Worker health examination is mandatory for all workplaces and many OPs allocate considerable time to its implementation. Occupational health organizations provide occupational health services such as worker health examinations to meet the demand. Basic training courses for OPs are provided by the Japan Medical Association and advanced courses are provided by the University of Occupational and Environmental Health, Japan. The Ministry of Labour recently launched a plan to establish occupational health centres to assist OPs at prefectural and regional levels. A network of such centres is planned to span the country within the next seven years.

[Therapeutic potential of sparfloxacin for preventing mycobacterial infections]

We studied the therapeutic potential of utilizing sparfloxacin (SPFX), a newly developed quinolone, to prevent various mycobacterial infections. The in vitro activity of SPFX as a preventive agent for various mycobacteria was determined using the actual count method on Ogawa egg medium. The minimal inhibitory concentrations (MICs) of SPFX were as follows: ofloxacin-sensitive M. tuberculosis, 0.16-0.32 microgram/ml; ofloxacin-resistant M. tuberculosis, 0.63-2.5 micrograms/ml; M. avium; 0.63-10 micrograms/ml (MICs were equal or less than 1.25 micrograms/ml in seven out of 11 strains); M. intracellulare, 2.5-10 micrograms/ml (MICs were equal or more than 10 micrograms/ml in 17 out of 23 strains); M. kansasii, < or = 0.08-0.16 microgram/ml; M. fortuitum, < or = 0.08 microgram/ml; M. chelonae subsp. abscessus, > 10 micrograms/ml; M. chelonae subsp. chelonae, 0.63 microgram/ml; M. scrofulaceum, < or = 0.08 microgram/ml; M. nonchromogenicum, 1.25 micrograms/ml; M. xenopi, < or = 0.08 microgram/ml; M. gordonae, < or = 0.08 microgram/ml. The average serum concentrations of SPFX during the period of multiple oral administration (200 mg once a day) were 0.35 +/- 0.16 microgram/ml before administration, 0.67 +/- 0.32 microgram/ml after one hour, 1.13 +/- 0.21 microgram/ml after two hours, 1.27 +/- 0.32 microgram/ml after four hours and 1.31 +/- 0.34 micrograms/ml after six hours. These results indicate that SPFX has a strong therapeutic potential to prevent infections due to M. tuberculosis, M. kansasii, M. fortuitum, M. chelonae subsp. chelonae, M. scrofulaceum, M. xenopi and M. gordonae. Moreover, it may be expected to be a promising agent against infections due to ofloxacin-resistant M. tuberculosis, M. avium and M. nonchromogenicum.

Consequences of acute nitric oxide synthesis inhibition in experimental glomerulonephritis

To assess the functional relevance of the enhanced glomerular nitric oxide (NO) synthesis during acute nephrotoxic serum (NTS) nephritis, a NO synthesis inhibitor (NOI) NG-monomethyl-L-arginine was administered to normal (N + NOI) and acutely nephritic (NTS + NOI) Munich-Wistar rats, and systemic and glomerular hemodynamic responses were contrasted with those observed in vehicle-treated normal and nephritic (NTS) controls. Urinary protein excretion rates were equal in normal and N + NOI rats but were markedly elevated in NTS animals and further increased in NTS+NOI. NO inhibition in normal animals (normal versus N + NOI) led to reductions in glomerular plasma flow rate and the glomerular capillary ultrafiltration coefficient (Kf) and elevations in afferent and efferent arteriolar resistances and net transcapillary hydraulic pressure difference (delta P), as well as an increase in systemic arterial pressure. The increase in delta P offset the falls in glomerular plasma flow rate and Kf, and GFR was preserved. Directionally similar responses in efferent resistance occurred in NTS + NOI compared with NTS, however, afferent resistance was not further affected by NOI. Additionally, although Kf was severely depressed in the NTS group (approximately 60% versus normal), it was not further depressed by NOI treatment. Polymorphonuclear cell (PMN) infiltration/glomerulus was mildly increased in N + NOI over normal. In contrast, PMN number in NTS + NOI rats was diminished as compared with NTS.(ABSTRACT TRUNCATED AT 250 WORDS)

10 kHz microsecond pulsed X-ray generator utilising a hot-cathode triode with variable durations for biomedical radiography

A 10 kHz pulsed X-ray generator utilising a hot-cathode triode in conjunction with a new type of grid control device for controlling X-ray duration is described. The energy-storage condenser was charged up to 70 kV by a power supply, and the electric charges in the condenser were discharged to the X-ray tube repetitively by the grid control device. The maximum values of the grid voltage (negative value), the tube voltage, and the tube current were -1.5 kV, 70 kV, and 0.4 A, respectively. The duration of the flash X-ray pulse was primarily determined by the time constant of the grid control device and the cut-off voltage of thermoelectrons. The X-ray duration was controlled within a region of less than 1 ms; the X-ray intensity with a pulse width of 0.27 ms, a charged voltage of 70 kV, and a peak tube current of 0.4 A was 0.92 microC kg-1 at 0.5 m per pulse. The maximum repetition rate was about 10 kHz, and the size of the focal spot was about 3.5 x 3.5 mm.

Sub-kilohertz flash X-ray generator utilising a glass-enclosed cold-cathode triode

The construction and fundamental studies are described for a sub-kilohertz X-ray generator for producing low-dose rate flash X-rays. The X-ray tube was a glass-enclosed cold-cathode triode, composed of a tungsten plate target, a rod-shaped graphite cathode, a mesh-type trigger electrode made of tungsten wires, and a glass tube body. The coaxial condenser was charged up to 60 kV by a power supply, and the electric charges in the condenser were discharged to the X-ray tube repetitively when a negative high-voltage pulse was applied to the trigger electrode. The maximum tube voltage before the discharging was equivalent to the initial charged voltage of the condenser, and the maximum tube current was about 0.3 kA with a charged voltage of 60 kV. The X-ray durations were about 1 microsecond, and the X-ray intensity was about 0.47 microC kg-1 at 0.5 m per pulse with a charged voltage of 60 kV. The maximum repetition rate of the X-rays was about 0.4 kHz, and high-speed radiography was performed.

Prostaglandin E2/parathyroid hormone-induced suppression of alkaline phosphatase activity is mediated by protein kinase C

1. Bone resorptive factors, prostaglandin E2 and parathyroid hormone are shown to suppress alkaline phosphatase activity in a rat osteoblastic cell line. 2. Phorbol myristate acetate, but not dibutyryl cAMP or calcium ionophore can suppress alkaline phosphatase activity. 3. The protein kinase C inhibitors (H89, staurosporine) are able to block the suppression of alkaline phosphatase activity induced by prostaglandin E2 and parathyroid hormone. 4. These data suggest that protein kinase C is involved in the inhibition of alkaline phosphatase activity induced by prostaglandin E2 and parathyroid hormone.

Retrovirus-mediated gene transfer of human pyruvate kinase (PK) cDNA into murine hematopoietic cells: implications for gene therapy of human PK deficiency

With the advent of recent molecular studies, nonspherocytic hemolytic anemia caused by red blood cell pyruvate kinase (PK) deficiency is now considered to be caused by a structural mutation of the PK-LR gene. Because PK deficiency is a monogenic disorder, the introduction of the normal PK gene into a patient's bone marrow stem cells should cure the disorder. To study the feasibility of gene therapy for PK deficiency, we first constructed the PK retrovirus pMNSM-hPK using human liver-type PK (LPK) cDNA and obtained a producer cell line of E86/AmPK. By using the supernatant of this virus-producer cell, we transduced NIH/3T3 cells, mouse leukemic cells (NFS60, FDCP-2), and human leukemic cells (K562, HEL). The expression of human LPK enzyme activity was ascertained from the retrovirally transduced NIH/3T3 cells. Northern blot analysis demonstrated the expression of the human LPK mRNA in each transduced cell line. Furthermore, bone marrow stem cells (c-kit+, Lin-, Thy-1lo) sorted by fluorescence-activated cell sorting were also transduced by the producer cells in the presence of interleukin-3 and interleukin-6, and were transplanted into lethally irradiated C57BL/6 mice. Polymerase chain reaction analysis demonstrated the expression of human LPK mRNA in both the peripheral blood and hematopoietic organs on day 30 and on day 135 of bone marrow transplantation.