Nerve growth factor induces resistance of PC12 cells to nitric oxide cytotoxicity

Nitric oxide (NO) donors, sodium nitroprusside and NOC 7, caused pheochromocytoma (PC12) cell death in a concentration and time-dependent manner. This cytotoxicity was blocked by the NO trapping agent, oxyhemoglobin. A membrane permeable cGMP analogue had no cytotoxicity in a reasonable concentration. Moreover, the selective inhibitor of cGMP-dependent protein kinase, KT5823, had no effect on NOC 7 cytotoxicity. These results suggest that NO caused PC12 cell death but not through the cGMP pathway. Additionally, this NO-induced PC12 cell death is not accompanied by DNA fragmentation. Nerve growth factor (NGF), which is able to rescue PC12 cells from serum deprivation, failed to protect PC12 cells from NO-induced cell death by acute treatment. However, PC12 cells differentiated by NGF treatment for more than 3 days did not die after NO exposure. The differentiated PC12 cells, but not undifferentiated cells, expressed NO synthase (NOS). NGF-differentiated PC12 cells acquired the resistance to NO, by a mechanism not yet identified, accompanied by the expression of NOS.

Effects of 1-[3-(4-benzhydryl-1-piperazinyl)propyl]-3- (1H-imidazol-1-ylmethyl)-1H-indole-6-carboxylic acid with thromboxane A2 synthetase inhibitory and H1-blocking activities on anaphylactic bronchospasm

1-[3-(4-Benzhydryl-1-piperazinyl)propyl]-3-(1H-imidazol-1-ylmethyl )- 1H-indole-6-carboxylic acid (CAS 172544-75-1, KY-234) was characterized pharmacologically. KY-234 (10(-9)-10(-6) mol/l) and ozagrel (10(-8)-10(-5) mol/l) inhibited the production of thromboxane A2 (TXA2) in rabbit platelets. KY-234 and pyrilamine at concentrations of 10(-9)-10(-6) mol/l relaxed the isolated guinea pig trachea contracted with histamine, while neither drug attenuated the heart rate increased by histamine. Cimetidine antagonized histamine in the right atrium but not in the trachea. KY-234 (10(-8)-10(-5) mol/l) and ozagrel (10(-7)-10(-4) mol/l), but not pyrilamine, attenuated the contraction induced by leukotriene D4 (LTD4) and platelet-activating factor in the lung parenchymal strips. In anesthetized guinea pigs, KY-234 (1-10 mg/kg p.o.) inhibited the LTD4- and histamine-induced bronchoconstriction. Ozagrel and terfenadine inhibited only the LTD4- and histamine-induced constrictions. KY-234 (3-30 mg/kg p.o.) inhibited the anaphylactic bronchoconstriction continuously for 15 min after antigen-challenge. Terfenadine (3-30 mg/kg p.o.) inhibited the constriction more strongly within the first 5 min (fast phase) than it did within 5 to 15 min (slow phase) after the challenge. Ozagrel (100 mg/kg p.o.) slightly attenuated only the constriction during the slow phase. These findings demonstrated that KY-234 has a selective TXA2 synthetase-inhibitory and H1-blocking activity and protects against anaphylactic bronchospasm more effectively than a TXA2 synthetase inhibitor or H1-blocker alone.

Sensitive determination of nitrotyrosine in human plasma by isocratic high-performance liquid chromatography

A highly sensitive and simple isocratic high-performance liquid chromatographic method was developed for determination of 3-nitrotyrosine in human plasma with precolumn derivatization with 4-fluoro-7-nitrobenzo-2-oxa-1,3-diazole. The precision of the method was satisfactory (coefficient of variation 4.8%), and the detection limit was established at 0.1 pmol of 3-nitrotyrosine allowing the determination at the level of 6 pmol/ml in human plasma. The recoveries of 3-nitrotyrosine and alpha-methyltyrosine, an internal standard, were 89.3 +/- 7.1 and 85.7 +/- 7.6%, respectively. The 3-nitrotyrosine level was 31 +/- 6 pmol/ml (mean +/- S.D., n = 9) in plasma from healthy volunteers. Since 3-nitrotyrosine is a stable product of peroxynitrite, an oxidant formed by a reaction of nitric oxide and superoxide radicals, the measurement of its plasma concentration may be useful as a marker of nitric oxide-dependent oxidative damage.

[A case of bilateral infarction of medial pontomedullary junction]

A 69-year-old man suffered from dizziness and nausea after work, and was admitted to our hospital on the next day. On admission, he showed bilateral horizontal nystagmus and left hemiparesis. On the 3rd day he vomited frequently, and the dizziness became worse. Bilateral horizontal and upward gaze palsy and bilateral facial nerve palsy were observed. Brain MRI on the 5th day disclosed bilateral upper medial medullary infarction that extended to the pontomedullary junction. Cerebral angiography on the 13th day revealed occlusion of the right vertebral artery. This case did not show typical medial medullary syndrome. The mechanism was unknown, but similar cases were reported. Recently, many cases of medullary infarction are reported with the progress of MRI technology. It is suggested that the addition of the new concepts on the conventional syndromes of medullary infarction is necessary.

Frequent loss in chromosome 8p loci in liver cirrhosis accompanying hepatocellular carcinoma

Most hepatocellular carcinoma (HCC) is preceded by liver cirrhosis, but the genetic changes involved in cirrhosis are not well understood. We therefore studied loss of heterozygosity (LOH) in cirrhotic and neoplastic foci in livers of 14 patients with HCC. The samples, microdissected from paraffin-embedded tissues, were analyzed using a polymerase-chain-reaction-based assay for dinucleotide repeat polymorphisms on 8p. Of the 14 cases, 13 showed constitutional heterozygosity for the microsatellite markers. In 7 (54%) of these 13 informative cases, LOH was detected in the primary HCC and, in these 7 doubly informative (informative and LOH-positive in primary HCC) cases, LOH was found in 16 (70%) of 23 liver cirrhotic foci. The pattern of 8p allelic loss was identical in each doubly informative tumor; however, some of the liver cirrhotic foci harbored an 8p loss identical to that seen in the primary HCC, some harbored a different 8p loss, and some did not harbor any 8p loss. The remaining 6 cases without LOH on 8p in HCC showed no 8p loss in any cirrhotic foci. Presumably HCC could develop from cirrhotic cells harboring 8p loss.

A new gastric ulcer model induced by ischemia-reperfusion in the rat: role of leukocytes on ulceration in rat stomach

A new model of gastric ulcer involving damage to the muscularis mucosae was developed by clamping the celiac artery in rat to induce ischemia-reperfusion (I-R) injury. Although erosions with falling off of the gastric mucosa were observed immediately, 24 and 36 hours after the I-R, gastric ulcers involving the injury of muscularis mucosae were observed in the area of gastric glands at 48 and 72 hours after initiation of injury. Administration of omeprazol, a proton pump inhibitor, or pentoxifylline, an anti-leukocyte drug, just after the initiation of injury significantly decreased the total area of ulcers at 72 hours. A combination of omeprazol and pentoxifylline was more effective than either drug alone. An anti-leukocyte adhesion molecule (anti-CD18 antibody) also showed significant inhibitory effect on the development of ulcers at 72 hours and the infiltration of leukocytes into both submucosa and mucosa. These results indicate that in our model, gastric acid together with leukocytes contribute to the development of ulcers following erosions. This model may be used to investigate the mechanisms of the development of gastric ulcer and evaluate antiulcer drugs in a preclinical setting.

Intraventricular administration of estradiol modulates rat prolactin secretion and synthesis

The effect of estradiol (E2) on rat tuberoinfundibular dopaminergic (TIDA) neurons was examined in vivo, employing chronic intraventricular (i.c.v.) infusion technique using an osmotic mini-pump. The activity of TIDA neurons was assessed by the release and synthesis of prolactin (PRL) in the rat pituitary gland and by the changes in the 3, 4-dihydroxyphenylacetic acid (DOPAC) and dopamine (DA) levels and in the DOPAC/DA ratio in the rat hypothalamus. We also examined the [3H] E2 binding in the rat hypothalamus. Ovariectomized female Wistar rats with E2 replacement were treated with daily i.c.v. infusion of 1 microM of E2 or saline vehicle for 1, 3, and 7 days using the Alzet osmotic mini-pump and brain infusion kit. At 1 day of i.c.v. infusion of E2, the serum PRL level was significantly decreased compared with that in the vehicle group. Northern blot analysis of the total RNA isolated from the pituitary glands demonstrated a decrease in the PRL gene transcript level in the E2 group. At 3 days of E2 treatment, however, the serum PRL level was significantly increased compared with that of the vehicle-injected group and Northern blot analysis also demonstrated that the PRL gene transcript level was increased in the E2 group. At 7 days of E2 administration, there were no significant differences between the E2 and vehicle groups in either serum PRL or PRL gene transcript levels. There was a significant increase in the DOPAC/DA ratio after 1 day in the E2 group. However, no significant effects of E2 on this ratio were observed at 3 and 7 days of treatment. The DOPAC concentration in the E2 group was significantly increased at day 1 and significantly decreased at day 3, compared with that of the respective time in vehicle group. At day 7 there was no significant change in DOPAC concentration in either groups. The DA concentrations in the hypothalamus was not changed on any day in either group. Specific [3H] E2 binding was observed in the rat hypothalamus. These data suggest that E2 may have a biphasic effect on the accumulation of PRL gene transcripts and on the PRL secretion in the rat pituitary by first stimulating and then inhibiting the TIDA neuronal activity.

Temporal and spatial distribution of ferredoxin isoproteins in tomato fruit

Five ferredoxin (Fd) isoproteins (FdA, FdB, FdC, FdD, and FdE) were isolated from tomato (Lycopersicon esculentum cv Momotaro) fruit. These isoproteins showed differential temporal and spatial accumulation patterns. FdA and FdC were present in leaves. FdE was present in roots, and FdB and FdD were fruit-specific. During fruit growth, the relative abundance of FdA decreased and that of FdE increased. The FdE/FdA ratio was higher in the inner tissues of the fruit than in the outer tissue, and it was correlated with starch accumulation. In darkgrown fruit the contents of FdA, FdB, and FdC, as well as chlorophyll, decreased remarkably relative to their light-grown counterparts; however, the contents of FdE and starch did not change significantly. Under in vitro conditions FdE showed higher cytochrome c reduction activity than FdA and FdB. These results, together with their N-terminal sequences, indicate that both photosynthetic- and heterotrophic-type Fd isoproteins are present in tomato fruit.

[Recovery from descending necrotizing mediastinitis and multiple organic failure after seven months of mechanical ventilation]

A 61-year-old man with a history of hypertension and diabetes mellitus had a tooth extracted. Nine days later, he was admitted to the hospital with complaints of high fever, dyspnea, and anterior chest pain. Physical examination revealed a drowsy man with a fever of 38.2 degrees C, blood pressure of 66/44 mmHg, and marked redness and swelling from the neck to anterior part of the chest. Laboratory examination indicated severe infection and multiple organ failure, consisting of cardiac, respiratory, renal, and hepatic failure, with disseminated intravascular coagulation. Chest X-ray and CT-scan films showed abscesses extending from the neck to the mediastinum, and bilateral pleural effusion. Immediately, he was treated with catecholamines, furosemide, mechanical ventilation with a high concentration of oxygen, continuous drainage, repeated skin incisions, and broad-spectrum antibiotics. In addition, steroid pulse therapy was administered for persistent respiratory failure. On the 28th hospital day, a fistula developed between the trachea and the mediastinum, and an intratracheal tube had to be inserted through the fistula. On the 212 th hospital day, after intravenous hyperalimentation, continuous intravenous insulin infusion, and administration of broad-spectrum antibiotics, catecholamines, and furosemide, the patient was weaned from mechanical ventilation. A restrictive ventilatory defect due to ankylosis and atrophy of underused muscles was noted after weaning, but the PaO2 was high with a low dose of oxygen (1 to 2 l/min), and 21 months later, the blood gases were normal while the patient was breathing room air. As of January, 1996, he was undergoing rehabilitation to promote his recovery from ankylosis, muscle atrophy, and speech dysfunction.

Altered prostaglandin metabolism induced by angiotensin-converting enzyme inhibitors in broncho-alveolar lavage fluid of the guinea pig

The aim of this study was to investigate if prostaglandin (PG) metabolism is altered by angiotensin-converting enzyme (ACE) inhibitors as determined in the broncho-alveolar lavage fluid (BALF) of the guinea pig. Enalapril or imidapril was orally administered once a day for 2 weeks to Hartley male guinea pigs. Twenty-four hours after the last treatment, BALF was collected and the concentrations of PGI2, thromboxane A2 (TXA2) and PGE2 were measured by enzyme immunoassay. Enalapril significanlty P < 0.05) increased the TXA2 content, which was inhibited by indomethacin treatment and significantly (P < 0.05) decreased the PGI2 content. Imidapril, however, did not affect TXA2 or PGI2 generation. These findings suggest that altered PG metabolism may be associated with coughing as a side effect of enalapril.

A new murine lymphocytotoxic monoclonal antibody recognizing HLA-A2, -A28 and -A9

Monoclonal antibodies recognizing polymorphic as well as monomorphic epitopes on HLA antigens are important tools for understanding the immunobiology of HLA molecules. We immunized BALB/c mice with a HLA-A2 transfectant and screened for hybridomas which reacted with a HLA-A2 transfectant but not with a HLA-B75 transfectant. After subcloning by limiting dilution four times, a hybridoma secreting a monoclonal antibody (mAb) (IgG 2a, kappa) designated 1-145 was established. 1-145 reacted with Epstein-Barr virus transformed B lymphoblastoid cell lines (B cell lines) which expressed HLA-A2, -A28, -A23 and -A24. The titer of 1-145 in culture supernatant against HLA-A2 and -A28 antigens was similar and the titer against HLA-A23 was lower. 1-145 reacted with cells expressing HLA-A24 but the titer against HLA-A24 antigens was even lower than that against HLA-A23 antigens. The HLA-A24 antigens on the peripheral blood lymphocytes were not detected by 1-145 possibly due to the lower expression compared to the B cell lines. These differences of the titers were reflected to microlymphocytotoxicity assay in which 1-145 culture supernatant lysed all PBLs expressing HLA-A2,-A28 and -A23 but did not lyse PBLs expressing HLA-A24. Published deduced amino acid sequence data of HLA class 1 molecules indicate that Lys in position 127 may be critical for 1-145 binding.

EAAT4 is a post-synaptic glutamate transporter at Purkinje cell synapses

To study cellular and subcellular localizations of the glutamate transporter EAAT4, antibody was raised against the N-terminal peptide. On immunoblotting the antibody recognized a band in membrane extracts from the cerebellum, but not from the forebrain. Immunohistochemistry revealed that its distribution was restricted to the cerebellar molecular layer, where the immunoreactivity was observed as numerous punctate stainings. Electron microscopy showed the antibody to label dendritic spines of the Purkinje cells. EAAT4 is, therefore, a Purkinje cell-specific, postsynaptic transporter. Together with dense localization of other transporter subtypes in Bergmann astrocytic membranes, Purkinje cell synapses are thus provided with distinct glutamate transporter subtypes at discrete synaptic elements, which would play important roles in regulating excitability of the Purkinje cells and protecting against excitotoxicity.

[Clinical studies on vancomycin in the treatment of MRSA infection]

We evaluated the effectiveness and safety of vancomycin (VCM) alone and in combination with beta-lactam antibiotics in the treatment of MRSA infections, and obtained the following results: 1. Effectiveness. (1) In cases of MRSA infections alone, the improvement rate was 71.4% (5/7 patients) with VCM alone and 77.8% (35/45) with VCM in combination with beta-lactam antibiotics. (2) In cases of polymicrobial infections, few cases were treated with VCM alone, but the improvement rate in combination use with beta-lactam antibiotics was 71.8% (28/39). 2. Bacteriological effect. (1) In cases of single infection with MRSA, the rate of bacterial eradication was 71.4% (5/7) with VCM alone and 68.2% (30/44) with VCM in combination with beta-lactam antibiotics. (2) In cases of polymicrobial infections, few cases were treated with VCM alone, but the rate of bacterial eradication in combination use with be ta-lactam antibiotics was 63.2% (24/38) against MRSA and 31.6% (12/38) against polymicrobial agents including MRSA. 3. Safety. Occurrences of adverse reactions and abnormal laboratory test values when VCM was used alone or when it is used in combination with another drug were about the same in these uses. As a whole, advance reactions were observed in 16 patients (9.5%). Main adverse reactions were whole body redness, drug eruption, and rash etc. Abnormal laboratory test values were observed mainly in hepatic functions, and renal functions. 4. VCM concentrations in blood was determined in 38 patients. Doses of 0.5 g and 1.0 g of VCM was administered by intravenous drip infusion over a period of 1 to 2 hours, and mean blood concentrations 1 to 2 hours after the completion of drip infusion were 25.4 micrograms/ml and 14.4 micrograms/ml, respectively. 5. Synergic effects between VCM and other antibiotics tested were observed in FIC index against all of the six MRSA strains isolated from six patients, and the clinical effects of improvement or better were obtained against five of them.

[Infections mononucleosis with pleural effusion]

A 24-year-old man was admitted to our hospital for further examination of pleural effusion. On physical examination, he had a temperature of 39 degrees C, the pharynx was painful and liver and spleen were enlarged. The leukocyte count was 5,700/microliters (atypical lymphocyte 6%). The serum LDH, GOT, GPT, ALP and gamma-GTP levels were elevated, and antibodies to Epstein-Barr viral capsid, early, and nuclear antigens were diagnostic of a primary Epstein-Barr virus infection. The CD4/CD8 ratio of peripheral blood lymphocyte was decreased to 0.2. The pleural effusion was exudate, and infiltration of mononuclear cells was noted. The CD4/CD8 ratio of lymphocytes in the effusion also was decreased to 1.1. The result of pleural biopsy showed a perivascular infiltration of mononuclear cells and immunological stain showed that the infiltrated cells were dominantly T-lymphocytes (about 90%). These findings suggested that the pathogenesis of pleural effusion in infectious mononucleosis was a pleulitis due to the infiltration of T-lymphocytes. Pleural effusion is known as a rare complication of infectious mononucleosis.

Effects of growth factors and gut hormones on proliferation of primary cultured gastric mucous cells of guinea pig

Almost completely homogenous gastric mucous epithelial cells of guinea pigs were grown to confluence in the presence of 10% fetal calf serum (FCS). FCS, epidermal growth factor (EGF), and insulin significantly increased 5-bromo-2'-deoxyuridine (BrdU) uptake by the cells and EGF together with insulin increased the cells' [3H] thymidine uptake. Basic fibroblast growth factor (bFGF) enhanced EGF-induced DNA synthesis by the cells, but vasoactive intestinal peptide (VIP), secretin, prostaglandin E2 (PGE2), and dibutyryl cyclic AMP (dbcAMP) neither induced DNA synthesis nor enhanced the effect of EGF on DNA synthesis by the cells. Gastrin, cholecystokinin-octapeptide (CCK8), and carbamylcholine chloride (CCh) also did not enhance the effect of EGF on DNA synthesis. 125I-EGF, 125I-bFGF, and 125I-gastrin binding to the gastric mucous cells revealed the presence of high-affinity receptors for EGF and bFGF, but not for gastrin. Northern blot analysis showed the expression of EGF receptor mRNA, but not gastrin receptor mRNA. These results suggest that EGF, insulin, and bFGF may cooperatively regulate gastric mucous cell growth, but that gastrin and other gastrointestinal hormones do not have a direct stimulatory effect on mucous cell growth in the guinea pig.

Cloning and characterization of the rat neurotensin receptor gene promoter

The 5'-terminal region of the rat neurotensin receptor (NTR) gene was isolated and characterized. Genomic Southern analysis revealed that the NTR gene occurs as a single copy in the rat haploid genome. The upstream putative promoter region did not contain canonical TATA or CAAT boxes but has a consensus sequence for the transcription factor Sp1. This promoter is embedded in a large G + C-rich domain with characteristics of an CpG island. Transfection experiments using neurotensin receptor-luciferase fusion genes demonstrated that the 5'-flanking sequence functions as a strong promoter in the NG-108-15 cell. Deletion analysis suggested the presence of a core promoter (-470 to -662) that drives the minimal expression of the NTR gene.

Effect of intranasal administration of thyrotropin-releasing hormone on ataxic gait in staggerer mice

The ataxia ameliorating effect of an intranasal administration of thyrotropin-releasing hormone (TRH) was examined using normal and ataxic staggerer mutant mice. In the normal mice, the blood TRH level reached the maximum level 5 min after administration and was gradually eliminated during the following 60 min. The antiataxic effects of TRH in the staggerer mice was examined using an open field method. At lower doses, the intranasal administration of TRH in the staggerer mice was examined using an open field method. At lower doses, the intranasal administration of TRH did not exert any evident effect. However, at 3 mg or 4 mg, the fall index (the ratio of the number of falls to the movement score) was significantly decreased for 20 min after the administration. These results show that an intranasal administration of TRH can ameliorate the ataxia in staggerer mice, and may be promising for clinical use in patients with spinocerebellar degeneration.

Effects of the novel water-soluble calcium antagonist (+/-)-3-(4-allyl-1-piperazinyl)-2,2-dimethylpropyl methyl 1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-3,5-pyridinedicarboxylate dihydrochloride on the endothelium-independent and endothelium-dependent contraction in isolated canine cerebral arteries

The inhibitory effects of NKY-722 (+/-)-3-(4-allyl-1-piperazinyl)-2,2-dimethylpropyl methyl 1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-3,5-pyridinedicarboxylate dihydrochloride, CAS 117241-46-0) on endothelium-independent and endothelium-dependent contractions were examined in comparison with nicardipine in isolated canine cerebral arteries. NKY-722 relaxed the cerebral arteries contracted endothelium-independently by KCl, prostaglandin F2 alpha U-46619 (a thromboxane A2 agonist) and endothelin-1 with IC50 = 2.5, 3.4, 2.8 and 3.6 x 10(-10) mol/l, respectively. On the basis of IC50 values, NKY-722 was about 2 times more effective than nicardipine. Pretreatment of NKY-722 and nicardipine inhibited the endothelium-independent contraction induced by KCl and serotonin to a similar degree. NKY-722 attenuated the endothelium-dependent contractions caused by acetylcholine (ACh), adenosine diphosphate and KO2 with IC50 = 1.7, 3.8 and 1.4 x 10(-9) mol/l, respectively. NKY-722 was about 2 times less effective than nicardipine. NKY-722 and nicardipine inhibited dose-dependently the endothelium-dependent contractions induced by hemolysate. NKY-722 was nearly equipotent to nicardipine on the phasic contraction and slightly more potent on the tonic contraction. The inhibitory effect of NKY-722 on the endothelium-independent contraction induced by KCl and the endothelium-dependent contraction induced by ACh were sustained for a longer time than that of nicardipine after repetitive wash-out. In conclusion, NKY-722 inhibited effectively the endothelium-independent and endothelium-dependent contractions in the cerebral arteries. The effect of NKY-722 was similar to, but longer-lasting than that of nicardipine.

[The antigen (CANDTEC antigen) detected by CAND TEC test for diagnosis of candidiasis]

Most guinea pigs inoculated with 5.4 x 10(9) of C. albicans intraperitoneally, produce CANDTEC antigen (GPCANDTECAG) in sera. The antigen is heat-labile (at 56 degrees C for 30 min) as is that in humans. According to gel filtration, the molecule size of the antigen from guinea pigs was 4000KDa or more. ELISA revealed the antigen-positive gel fractions to contain a small amount of mannan from the yeasts and C3. ELISA using rabbit anti-GPCANDTECAG serum indicated that the two CANDTEC antigens from guinea pigs and humans shared determinants. Gel filtration indicated that the CANDTEC antigen from patients was from 4000KDa to 3000KDa. In the antigen-positive gel fractions, IgM was detected by ELISA, but mannan and C3 were not detected. However, immunoblotting analysis on the antigen-positive fraction revealed a unique band of 200KDa, stained with concanavalin A-ALP. These findings indicate that CANDTEC antigens in guinea pigs and humans are immune complexes formed after infection of Candida, although the antigens have different components.

Requirement of cell interactions through adhesion molecules in the early phase of T cell development

We investigated the role of adhesion molecules in T cell development. A large proportion of murine fetal thymus (FT) cells obtained at Day 13 of gestation, which are c-kit+, express the adhesion molecules Pgp-1, VLA-4, LFA-1, and ICAM-1 on their surface at high levels. The expression profiles of these adhesion molecules resemble quite well those on c-kit+ cells in fetal liver (FL). The level of expression of these molecules on FT cells declines with the embryonal age and becomes mostly negative by birth except for LFA-1. In the case of LFA-1, a reincrease of expression levels is seen in newborn mice. The role of these adhesion molecules in T cell development was investigated by adding monoclonal antibodies (mAb) into the FT organ cultures, where T cell development from FT or FL progenitors was induced by coculturing these cells with a deoxyguanosine-treated FT lobe. We found that anti-Pgp-1, anti-LFA-1, and anti-VLA-4 mAb severely inhibited the early phase of T cell development from FL progenitors. On the other hand, the suppressive effect of these mAb on the T cell development from FT progenitors was only slight, if any. These findings strongly suggest that interactions with elements in the thymic microenvironment through Pgp-1, LFA-1, and VLA-4 are indispensable for prethymic progenitors to develop into T cells.

[Susceptibilities of bacteria isolated from patients with respiratory infectious diseases to antibiotics (1994)]

Bacteria isolated from lower respiratory tract infections were collected in cooperation with institutions located throughout Japan, since 1981. IKEMOTO et al. have been investigating susceptibilities of these isolates to various antibacterial agents and antibiotics, and characteristics of the patients and isolates from them each year. Results obtained from these investigations are discussed. In 23 institutions around the entire Japan, 492 strains of presumably etiological bacteria were isolated mainly from the sputum of 421 patients with lower respiratory tract infections from October 1994 to September 1995. MICs of various antibacterial agents and antibiotics were determined against 70 strains of Staphylococcus aureus, 101 strains of Streptococcus pneumoniae, 92 strains of Haemophilus influenzae, 61 strains of Pseudomonas aeruginosa (non-mucoid strains), 25 strains of Pseudomonas aeruginosa (mucoid strains), 48 strains of Moraxella subgenus Branhamella catarrhalis, 14 strains of Klebsiella pneumoniae etc., and the drug susceptibilities of these strains were assessed except for those strains that died during transportation. 1. S. aureus. S. aureus strains for which MICs of oxacillin were higher than 4 micrograms/ml (methicillin-resistant S. aureus) accounted for 51.4%, but the frequency of the drug resistant bacteria decreased comparing to the previous year's 56.0%. Vancomycin showed the highest activity against S. aureus with MIC80 of 0.5 microgram/ml. 2. S. pneumoniae. Most of the drugs tested showed potent activities against S. pneumoniae. Imipenem of carbapenems showed the most potent activity with MIC80 was 0.063 microgram/ml. Erythromycin and clindamycin showed low activities with MIC80s > or = 256 micrograms/ml. Among these strains, however, 46.5% and 68.3% of strains, were quite sensitive toward these agents, respectively, with MICs of 0.063 microgram/ml. 3. H. influenzae. The activities of all drugs were potent against H. influenzae tested. Cefmenoxime a cephem, showed the most potent activity, the MICs of this drug against all of the 92 strains were 0.063 microgram/ml. Ofloxacin also showed a potent activity, and inhibited about 96% of strains with MIC of 0.063 microgram/ml. 4. P. aeruginosa (mucoid strains). Tobramycin showed the most potent activity against P. aeruginosa (mucoid strains) with MIC80 of 0.5 microgram/ml. Gentamicin, arbekacin and ciprofloxacin showed next potent activities, and their MIC80s were 2 micrograms/ml. 5. P. aeruginosa (non-mucoid strains). Tobramycin showed the most potent activity against P. aeruginosa (non-mucoid strains) with MIC80 of 2 micrograms/ml. Comparing to the activities against P. aeruginosa (mucoid strains), the activities of all the drugs tested were lower against P. aeruginosa (non-mucoid strains). 6. K. pneumoniae. Carumonam showed the most potent activity against K. pneumoniae with MIC80 of 0.063 microgram/ml. Cefozopran showed the next most potent activity with MIC80 of 0.125 microgram/ml. Ampicillin and cephems except cefpodoxime, cefozopran and cefditoren showed low activities and their MIC80s were > or = 16 micrograms/ml, and their MICs were all higher than > or = 4 micrograms/ml. 7. M. (B.) catarrhalis. Imipenem and ofloxacin showed the most potent activities against M. (B.) catarrhalis, their MIC80s were 0.063 microgram/ml. Erythromycin and minocycline showed the next highest activities with their MIC80s at 0.25 microgram/ml. Also, we investigated year to year changes in the background of patients, the respiratory infectious diseases, and the etiology of bacteria. Patients characteristics, in this period of investigation showed varieties of infectious diseases found in patients in a high age bracket, and the patients over age 60 accounted for 62.0% of all the cases. Different lower respiratory tract infectious were distributed as follows: chronic bronchitis and bacterial pneumonia accounted for the greatest number of cases with 35.6%, 27.1%, respectively, followed by

A chemiluminescent detection of superoxide radical produced by adherent leucocytes to the subendothelium following thrombolysis: studies with a photochemically induced thrombosis model in the guinea pig femoral artery

Reocclusion following thrombolysis is a major limitation of thrombolytic therapy with recombinant tissue-type plasminogen activator (rt-PA) because denuded vessel wall exposed to blood following thrombolysis is a favourable surface for platelet and leucocyte deposition. We have applied a chemiluminescence technique to detect superoxide radical (0(-2)) produced by leucocytes adherent to the femoral artery 24 h after photochemically induced thrombogenesis in the guinea pig in vivo and subsequent thrombolysis by rt-PA. Intravenous administration of MCLA, a specific chemiluminescence reagent for detecting O(-2), markedly increased photon emission. the photon emission was markedly potentiated by phorbol myristate acetate and was suppressed by superoxide dismutase. Reocclusion 24 h after rt-PA induced thrombolysis was observed in 10 of 16 animals. Histological observations revealed extensive polymorphonuclear leucocytes adherent to the vessel wall at the site of thrombogenesis and thrombolysis. A higher level of 0(-2) could be detected from the arteries in which thrombolysis was induced compared with those without thrombolysis. Further, the level 0(-2) detected was greater in reoccluded arteries compared with those in which reflow was established. These observations suggest that 0(-2) is produced by adherent leucocytes at the site of thrombolysis and that leucocytes are involved in reocclusion after thrombolysis.

Effects of a small dose of triazolam on P300 and resting EEG

The aim of the present study was to clarify whether cognitive impairments caused by benzodiazepines (BDZs) are a consequence of their specific direct effects on cognitive function or whether they are explained as secondary effects of increased sleepiness. Ten healthy men (mean age, 33.9 years) participated in two experimental sessions in a randomized cross-over, double-blind study: in one session subjects were given a placebo and in the other they were given 0.125 mg triazolam (TRZ). Each experimental session was conducted on 1 day. After a pre-drug EEG recording and an event-related potential (ERP) recording, under an oddball paradigm, subjects took the TRZ or placebo orally at 1000 hours. Thereafter, EEG and ERP recording sessions, following the same procedure as the pre-drug sessions, were conducted at 1, 2, 4, 6 and 8 h after drug administration. The EEG and ERP recordings from Cz and Pz referred to the bilaterally linked ear electrodes were used. We found that P300 latency was significantly prolonged in TRZ condition at 2 h (Pz) and 4 h (Cz and Pz) after TRZ, and that the P300 amplitude was significantly reduced at 2 h (Cz and Pz) and 4 h (Pz) after TRZ, compared to the same times after placebo. The absolute power values for the theta (4-7 Hz), alpha 1 (8-9 Hz), and alpha 2 (10-12 Hz) bands did not differ at any measurement time between the treatments. Only the beta band (13-19 Hz) power value was significantly elevated after the TRZ administration (versus placebo). No significant sedative effects were detected in subjective measurements. These results indicate that a single oral dose of 0.125 mg TRZ caused cortical changes without distinct general sedation or subjective sleepiness.

Genomic organization, promoter analysis, and chromosomal localization of the gene for the mouse glial high-affinity glutamate transporter Slc1a3

The mouse gene encoding glial high-affinity, Na+-dependent glutamate transporter Slc1a3 (GluT-1/GLAST) was isolated, and its structural organization was characterized. The gene appeared to exist as a single copy in the mouse genome and comprised 10 exons spanning more than 56 kilobases. The transcription initiation sites were mapped to positions 503, which is the first transcriptional point (defined as +1), 128 (+376), and 64 (+440) basepairs upstream of the 3'-end of exon 1 by primer extension. The 5'-flanking region of the mouse GluT-1 gene had a typical CCAAT box and a GC box but lacked a TATA box. These features of the promoter region were characteristic of housekeeping genes. The fusion plasmids containing approximately 4 kb of the 5'-flanking region (-3830 to +450) and the firefly luciferase gene induced a significant luciferase activity when transfected into COS-1 cells. Distal deletion of the 5'-flanking region, leaving 619 bp (-169 to +450), resulted in a marked decrease in luciferase activity in COS-1 cells, suggesting that a CCAAT box, which was positioned at -200, is necessary for the expression of this gene. In situ hybridization localized this gene to mouse chromosome 15A2. These structural features will lead to a better understanding of the regulatory mechanism of the expression of the GluT-1 gene by ischemia and will also provide a basis for future evolutionary comparisons with other neurotransmitter transporters.