Enhancement of magnetoresistance by hydrogen ion treatment for current-perpendicular-to-plane giant magnetoresistive films with a current-confined-path nano-oxide layer.

We have enhanced magnetoresistance (MR) for current-perpendicular-to-plane giant-magnetoresistive (CPP-GMR) films with a current-confined-path nano-oxide layer (CCP-NOL). In order to realize higher purity in Cu for CCPs, hydrogen ion treatment (HIT) was applied as the CuO(x) reduction process. By applying the HIT process, an MR ratio was increased to 27.4% even in the case of using conventional FeCo magnetic layer, from 13.0% for a reference without the HIT process. Atom probe tomography data confirmed oxygen reduction by the HIT process in the CCP-NOL. The relationship between oxygen counts and MR ratio indicates that further oxygen reduction would realize an MR ratio greater than 50%.

Effect of air pollution and environmental tobacco smoke on serum hyaluronate concentrations in school children.

OBJECTIVES: To evaluate serum hyaluronate concentrations relative to air pollution, environmental tobacco smoke (ETS), and respiratory health in Japanese school children. METHODS: Respiratory symptoms and serum IgE concentrations were examined in 1037 school children living in four communities in Japan with differing levels of air pollution. Serum hyaluronate concentrations were assayed in 230 children, consisting of all the children who had symptoms of either asthma or wheeze (65 and 50 subjects, respectively) and normal controls adjusted for sex, school grade, and school without these symptoms (115 subjects). RESULTS: Although serum hyaluronate concentrations did not differ for either asthma or wheeze, the concentrations were significantly higher in children living in communities with higher levels of air pollution. Children with asthma or wheeze and those with serum IgE concentrations of 250 IU/ml or above showed differences in hyaluronate concentrations that related to the degree of air pollution in the communities. In children with higher serum IgE concentrations, the hyaluronate concentrations among subjects exposed to ETS were significantly higher than among those without exposure to ETS. CONCLUSIONS: The present results suggest that serum hyaluronate concentration is related to the degree of air pollution and exposure to ETS. Children with asthma or wheeze and children with higher IgE concentrations are considered to be more susceptible to environmental factors.

Region of heat-stable enterotoxin II of Escherichia coli involved in translocation across the outer membrane.

Heat-stable enterotoxin II of Escherichia coli (STII) is synthesized as a precursor form consisting of pre- and mature regions. The pre-region is cleaved off from the mature region during translocation across the inner membrane, and the mature region emerges in the periplasm. The mature region, composed of 48 amino acid residues, is processed in the periplasm by DsbA to form an intramolecular disulfide bond between Cys-10 and Cys-48 and between Cys-21 and Cys-36. STII formed with these disulfide bonds is efficiently secreted out of the cell through the secretory system, including TolC. However, it remains unknown which regions of STII are involved in interaction with TolC. In this study, we mutated the STII gene and examined the secretion of these STIIs into the culture supernatant. A deletion of the part covering from amino acid residue 37 to the carboxy terminal end did not markedly reduce the efficiency of secretion of STII into the culture supernatant. On the other hand, the efficiency of secretion of the peptide covering from the amino terminal end to position 18 to the culture supernatant was significantly low. These observations indicated that the central region of STII from amino acid residue 19 to that at position 36 is involved in the secretion of STII into the milieu. The experiment using a dsbA-deficient strain of E. coli showed that the disulfide bond between Cys-21 and Cys-36 by DsbA is necessary for STII to adapt to the structure that can cross the outer membrane.

Highly efficient oligosaccharide synthesis on water-soluble polymeric primers by recombinant glycosyltransferases immobilised on solid supports.

Recombinant beta-1,4-galactosyltranferase (beta 1,4-GalT) and alpha-2,6-sialytransferase (alpha 2,6-SiaT) immobilised covalently with activated Sepharose beads were employed for the practical synthesis of a trisaccharide derivative, Neu-5Ac alpha(2-->6)Gal beta(1-->4)GlcNAc beta-O-(CH2)6-NH2, on a water-soluble primer having GlcNAc residues through a alpha-chymotrypsin-sensitive linker.

Protection by polaprezinc, an anti-ulcer drug, against indomethacin-induced apoptosis in rat gastric mucosal cells.

Polaprezinc [N-(3-aminopropionyl)-L-histidinato zinc] (PZ), an anti-ulcer drug, is a chelate compound consisting of zinc and L-carnosine. PZ has been shown to prevent gastric mucosal injury. In the present study, we investigated the inhibitory effect of PZ on indomethacin (IND)-induced apoptosis in a rat gastric mucosal cell line, RGM1. Pretreatment with PZ suppressed caspase-3 activation and subsequent apoptosis in the cells exposed to 500 microM IND in a dose-dependent manner, and 50 microM PZ exhibited the maximum inhibitory effect. Among PZ subcomponents, zinc but not L-carnosine played a pivotal role in this antiapoptotic function. PZ did not affect mitochondrial cytochrome c release upstream of caspase-3 activation in the IND-induced apoptotic signal pathway. Treatment with 500 microM IND evidently produced reactive oxygen species (ROS) in RGM1 cells. However, PZ did not scavenge ROS in IND-treated cells. Moreover, N-acetylL-cysteine, a potent antioxidant, inhibited ROS generation but did not suppress apoptosis in RGM1 cells exposed to IND. These observations demonstrate a novel pharmacological action of PZ; i.e., that PZ, and in particular its zinc subcomponent, inhibits apoptosis via inhibition of caspase-3 activation but not antioxidant activity.

Upregulation of P53 protein in rat heart subjected to a transient occlusion of the coronary artery followed by reperfusion.

The accumulation of p53 protein in cardiomyocyte nuclei was immunohistochemically demonstrated by the pronounced staining of p53 antibody in 4 h-reperfused ventricular tissue after a 45-min coronary occlusion. The occurrence of apoptosis in the reperfused ventricular tissue was evidenced by positive TUNEL staining and DNA laddering on agarose gels.

Scanning electron microscopic study of flowing erythrocytes in hepatic sinusoids as revealed by 'in vivo cryotechnique'.

The purpose of this study is to develop a method for stabilizing erythrocytes under flowing condition in living livers, as revealed by scanning electron microscopy (SEM). After the procedure of the 'in vivo cryotechnique', both freeze-substitution and subsequent t-butyl alcohol freeze-drying methods were used for preparing SEM specimens. By freeze-fracturing with a scalpel in liquid nitrogen before the freeze-substitution, better preserved surface tissues were obtained for examination. Erythrocytes in hepatic sinusoids were clearly detected without plasma components by the freeze-substitution method, and well preserved in parts where they were flowing with their original shapes. Some were accumulated in sinusoids, especially injunctioning areas of sinusoidal networks, as compared with those in narrow lumens between hepatocyte plates. Shapes of such erythrocytes were various, locating along endothelial cells. After stopping the blood supply into livers by artificial cardiac arrest, their shapes were dramatically changed into biconcaves and they became aggregated side by side to be packed in the sinusoids. The three-dimensional shapes of flowing erythrocytes in hepatic sinusoids were demonstrated for the first time by the 'in vivo cryotechnique' combined with SEM.

A long-term suppression by alpha-interferon of Philadelphia chromosome in children with chronic myelogenous leukemia.

An 8 year old girl with adult type Philadelphia (Ph1)-positive chronic myelogenous leukemia received natural alpha-interferon therapy in the chronic phase. Complete suppression of the Ph1 clone of bone marrow cells was achieved after 1 month of therapy, which was determined by disappearance of rearranged breakpoint cluster region (BCR) gene in Southern blot analysis. Complete hematological remission was also attained following 2 months of therapy. Both the suppression and the hematological remission have been sustained for 24 months with alpha-interferon, in spite of the detection of the chimeric BCR/ABL mRNA in her bone marrow by polymerase chain reaction assay 12 months after therapy.

[Wallenberg's syndrome due to vertebral artery dissection following minimal neck injury--report of two cases].

We described two cases of the lateral medullary syndrome (Wallenberg's syndrome) due to vertebral artery dissection following minimal neck injuries. The first case was a 45-year-old man, who hit his head and often rotated his head because of posterior neck discomfort. Two years after the injury, he suffered from sudden sharp neck pain, nausea, and vertigo, which was followed by left hand numbness and difficulty in walking due to the right lateral medullary syndrome. Angiography showed right vertebral artery dissection at the fourth segment. The second case, a 48-year-old man, suffered from neck pain immediately after he hyperextended his neck for painting a wall. Within several hours, he experienced left hand numbness and difficulty in walking due to the lateral medullary syndrome. Angiography showed a saccular aneurysm and dissection of the right vertebral artery at the fourth segment. In both cases, minor traumas were thought to be the causes of vertebral artery dissection. We surveyed previously reported 84 cases (men: 50, women: 34) of the vertebral artery dissection due to minor traumas. Seventy per cent of patients were in their third or fourth decade of life. The main causes of trauma preceding the dissection were neck manipulation especially chiropractics (52%). The third segment was most vulnerable. Delay in onset following neck trauma could be more than a week, but in most cases the delay was less than 24 hours. Cervical rotation and extension were thought to precipitate dissection.

[Motor-dominant neuropathy with multifocal conduction block].

Patient 1 was a 39-year-old man; patient 2, a 42-year-old woman; patient 3, a 78-year-old man. Leading symptoms were chronic asymmetrical weakness in all three cases, which started in a distal portion of the upper extremities. Muscle atrophy was often less prominent than would be expected from the power of the muscle. Fasciculations were observed in two patients and the initial symptom of patient 2 was painful cramp of the right thumb. Patient 1 initially had mild transient dysesthesia of the right fingers. The other two patients had no sensory symptoms or signs. General laboratory tests revealed no particular abnormalities except that patient 3 had mild diabetes mellitus, although the type of neuropathy in patient 3 was quite different from diabetic neuropathy. Total protein concentrations in the cerebrospinal fluid were 34, 32 and 43 mg/dl in three patients, respectively (normally, less than 40 mg/dl). Motor nerve conduction studies revealed conduction block in more than one nerve in every case. Conduction velocities were generally normal in those segments of nerve where conduction block was not detected. Serum anti-ganglioside antibodies were investigated by Enzyme-linked immunosorbent assay (ELISA). Glycolipids used as the antigen include GM1, GM2, GM3, GD1b, GD3, GT1b, GQ1b, GA1 and galactocerebroside. Strong IgM antibody activity against GM1, GD1b and GA1 was noted in patient 1. Weaker but significant IgM antibody activities against GM1 and GA1 were detected in patient 2 and 3. Thin-layer chromatography immunostaining also confirmed these results. Muscle biopsy in patient 1 revealed a lot of target fibers and profuse polyglucosan bodies in the axons of intramuscular nerves.(ABSTRACT TRUNCATED AT 250 WORDS)

Differential response of B cells in the lymph node and the spleen to bacterial lipopolysaccharide.

In vivo polyclonal activation of B cells in the lymph nodes and the spleens of mice injected with bacterial lipopolysaccharide (LPS) was compared. The peak of anti-trinitrophenylated sheep red blood cells plaque-forming cell (PFC) response in the lymph node was reached 6-8 days after the injection of LPS while that in the spleen was reached at 2 days. The maximal increase in the total number of Ig-producing cells in the lymph node also occurred at the later stage. These differences in time courses of polyclonal activation of B cells between the lymph node and the spleen were not due to the absence of B cells in the lymph node, migration of PFC from the spleen to the lymph node, or qualitative differences of B cells. This phenomenon was dependent on the environmental difference between the lymph node and the spleen, because B cells from the lymph node could respond to LPS rapidly in the spleen. Further, the polyclonal activation of B cells was accelerated in the lymph nodes of mice receiving prior injection of LPS. In in vitro cultures of lymph node cells of those mice, a significant amount of interleukin-1 could be detected by stimulation of LPS. It was possible that the delayed activation of B cells in the lymph node was due to the time lag necessary for construction of the environmental condition suitable for activation of B cells, whereas in the spleen this condition can be provided without delay.

Hepatocellular carcinoma with extrahepatic growth: a case report and review of the Japanese literature.

A case of extrahepatically growing hepatocellular carcinoma is reported, and the Japanese literature is reviewed. A 42-year-old man was admitted to our hospital on December 27, 1985 complaining of epigastralgia and nausea. Ultrasonography and computerized tomography showed a large tumor in the right hepatic lobe. This Was removed surgically and examined histologically.

Hormonal and renal responses to oral once-daily calcium entry blocker in normotensive and hypertensive persons.

A newly produced calcium entry blocker, KW3049 (Kyowa Hakko, Tokyo, Japan), which maintains its antihypertensive action for greater than 24 h, was administered orally once daily to 12 subjects (5 normotensive, 7 hypertensive) for 12 days. To elucidate its hypotensive efficacy and mechanisms of action, daily changes in blood pressure and heart rate, serial alterations in the renin-angiotensin system and sympathetic nervous system, and the renal hemodynamics were investigated. KW3049 caused a significant decrease in mean arterial pressure from 124 + 3 to 107 + 2 mm Hg, accompanied by a moderate increase in heart rate (+15%). The urine volume and urinary excretion of sodium were persistently increased in hypertensive subjects with improvement of the renal blood flow. The plasma renin activity and plasma and urinary norepinephrine (NE) increased significantly (p less than 0.05) on the sixth day and returned to baseline levels on the twelfth day. In addition to these renal and hormonal changes, the pressor responses to infused NE and angiotensin II were attenuated on the twelfth day after KW3049 administration. The above findings suggest that only once-daily administration of KW3049 is able to reduce the blood pressure without fluctuation, and its antihypertensive mechanisms are related to a natriuretic action and attenuation of pressor responses as well as to strong vasodilation.

Effect of vasoactive substances on natriuresis induced by atrial natriuretic peptide in isolated perfused rat kidneys.

We studied the interaction between synthetic atrial natriuretic peptide (ANP) and various vasoactive substances, which included isoproterenol (ISO), aminophylline (AMI), and dibutyryl cyclic AMP (dBcAMP) as vasodilators, and angiotensin II (AII) and norepinephrine (NE) as vasoconstrictors, and prazosin as an alpha-blocker in isolated perfused rat kidneys (IPK). When 10(-9) mol of ANP was administered in 75 ml of a perfusate, the renal vascular resistance (RVR) was transiently decreased for 5 min, and increased thereafter. Simultaneously, ANP increased the glomerular filtration rate (GFR), urine flow (UV), absolute Na excretion (UNaV) and absolute K excretion (UKV). All of the above mentioned effects of ANP were significantly inhibited by administering ISO, AMI or dBcAMP. On the other hand, the administration of AII and NE significantly enhanced the increases in UV and UNaV and the fractional excretion of Na induced by ANP, although AII and NE had no influence on the changes in RVR and GFR induced by ANP. Prazosin did not modify the renal effects of ANP. These results suggest that the natriuretic effect of ANP is inhibited by agents that increase cyclic AMP in vascular smooth muscle cells. It is also suggested that the natriuretic effects of ANP can be explained by an increase in GFR and changes in intrarenal hemodynamics, rather than by the direct effect of ANP on renal tubules.