Isotope effects on delayed annihilation time spectra of antiprotonic helium atoms in a low-temperature gas.
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Journal Article↗
Biomedical subjects
H Tamura
Publications and source records attributed to H Tamura.
Effects of impurity atoms and molecules on the lifetime of antiprotonic helium atoms.
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Journal Article↗
Evaluation of the therapy for streptococcal pharyngitis using Abbott Test Pack strep A.
A total of 953 children (511 boys and 442 girls) with streptococcal pharyngitis diagnosed with Abbott Test Pack Strep A (ATPSA) or throat cultures were analyzed. ATPSA specimens were repeatedly obtained until ATPSA turned negative during or after the treatment. The percentage of positive ATPSA specimens reached the lowest value (9.2%) on the fourth day of the course of the treatment, which indicates the acquisition from an infected individual is probably uncommon after the initial treatment. Bacteriological treatment failure (positive ATPSA after 14 days of treatment) occurred in 4.1% of the children. Out of 953 subjects studied, 216 (22.7%) had recurrent infections. More than 30% of the recurrent infections occurred within 2 months after initial infection. ATPSA is useful for establishing a rapid diagnosis and confirming the bacteriological success of the treatment.
Adolescent↗
Less segregated processing of visual information in V2 than in V1 of the monkey visual cortex.
To test the possibility of cross-talk between parallel pathways dealing with different aspects of visual information such as orientation, direction of motion and colour in cortical area V2, we quantitatively analysed visual responses of 121 V2 cells recorded from anaesthetized and paralysed macaques and compared them with those of 147 V1 cells. A selectivity index of visual responses was calculated for each neuron, which was then classified as selective or not to a particular attribute of visual stimuli. Twenty-one percent of the V2 neurons had dual selectivity to both colour and direction of stimulus motion (C&D cells). In V1, only 5% of the cells were C&D cells. Thus, the proportion of C&D cells significantly increased from V1 to V2. We also carried out cross-correlation analysis of spike trains recorded simultaneously from pairs of V2 neurons or pairs of V1 neurons. In V2, correlated firings could be observed between cells with completely different optimal orientation, such as orthogonal, while it was never observed in V1. The cross-correlation analysis further indicted that functional interactions in V2 were more widespread than those in V1. These results suggest that neurons which have different functional properties become less segregated, and that functional interactions become more widespread in V2 than in V1.
Animals↗
Blood clearance of (1-->3)-beta-D-glucan in MRL lpr/lpr mice.
(1-->3)-beta-D-Glucans have a variety of biological and immunopharmacological properties, and they are used clinically as biological response modifiers (BRMs). Clinically, these glucans have often been used for long periods by multiple dosing. During studies on the clearance and metabolism of the glucans in mice, we have found that, in the case of a single dose, the glucan was cleared from blood eventually, and remained constant in the organs for at least one month. Here, we investigated the clearance of glucans from the blood following multiple dosing using MRL lpr/lpr mice with an autoimmune disease. Two kinds of glucans, GRN from Grifola frondosa and SSG from Sclerotinia sclerotiorum, were administered to the mice once a week for more than 35 weeks (250 micrograms/week/mouse by the intraperitoneal route). Examination of the blood clearance of the glucans in these mice revealed that the glucan concentrations were always high (about 20 micrograms/ml for GRN and 200 micrograms/ml for SSG). It is also shown that the glucans were significantly deposited in the liver and spleen of these mice. These findings suggest that administration of a large quantity of the glucan saturated the reticuloendothelial system, resulting in circulation of the glucan in the blood.
Animals↗
Effects of interleukin-2 and cyclosporin A on pathologic features in Mycoplasma pneumonia.
To elucidate the immunopathologic mechanisms of Mycoplasma pneumonia, the effects of interleukin-2 (IL-2) and cyclosporin A (CYA) on Mycoplasma pneumonia in mice were investigated. Mice were intranasally inoculated with Mycoplasma pulmonis (M. pul) and treated with IL-2, CYA, or minocycline (MINO) every day between Days 3 and 9. They were killed at Days 7, 14, or 21 after the inoculation. Cell-mediated immunity (CMI) of the host was assessed by delayed-type hypersensitivity (DTH) to sheep red blood cells (SRBC). Peribronchial and perivascular lymphocyte cuffing and the accumulation of macrophages at the ends of bronchioles were exacerbated (p < 0.05) in IL-2-treated mice at Day 14 and reduced (p < 0.05) in CYA-treated mice at Day 7. Although the DTH responses to SRBC of saline-inoculated, IL-2-treated mice were increased at Days 7 (p < 0.01) and 14 (p < 0.05), those of M. pul-inoculated, IL-2-treated mice at Day 7 could not recover to the control level. The CMI levels of M. pul-inoculated, CYA-treated mice were decreased at Days 7, 14 (p < 0.05), and 21 (p < 0.01). Mycoplasma organisms in the lung showed the greatest decrease (p < 0.05) in MINO- and IL-2-treated mice, but increased at Day 21 (p < 0.05) in mice treated with IL-2 alone. These results suggest that the pathologic features of Mycoplasma pneumonia could be modified by the degree of host CMI.
Animals↗
Progesterone inhibits superoxide radical production by mononuclear phagocytes in pseudopregnant rats.
This study investigated the changes in superoxide radical production by mononuclear phagocytes in the corpus luteum (CL) during pseudopregnancy in rats. Activity of superoxide radical production was determined by the conversion of nitro blue tetrazolium (NBT) to blue formazan deposit. Rats received 10 mg NBT via the abdominal aorta on day 3, 7, or 13 of pseudopregnancy and were autopsied 1 min later to prepare the histological sections. The cells with blue formazan deposits (NBT-positive cells) in the CL were scarce on days 3 and 7 of pseudopregnancy and significantly increased on day 13 of pseudo-pregnancy. On the other hand, simultaneous administration of 100 micrograms phorbol 12-myristate 13-acetate, which activates mononuclear phagocytes to produce superoxide radical, significantly increased the numbers of NBT-positive cells in the CL on day 7 of pseudopregnancy, but not in the CL on day 3 or 13 of pseudopregnancy. To study the possibility that superoxide radical production by mononuclear phagocytes is inhibited by progesterone on day 7 of pseudopregnancy, peritoneal mononuclear phagocytes prepared on day 7 or 13 of pseudopregnancy were preincubated with 10, 50, or 100 ng/ml progesterone for 6 h and then stimulated with phorbol 12-myristate 13-acetate. Superoxide radical production was measured by the cytochrome c reduction method. One hundred nanograms per ml progesterone significantly inhibited superoxide radical production by mononuclear phagocytes, and this inhibitory effect of progesterone was significantly blocked by the simultaneous addition of RU486 (10(-7) M). These results suggested that progesterone inhibited superoxide radical production by the mononuclear phagocytes in the CL during midpseudopregnancy in rats.
Animals↗
A study of the luteolytic mechanism of the antiprogesterone RU486 during the late-luteal phase in pseudopregnant rats.
The purpose of this study was to examine the possible mechanism through which RU486 induces luteolysis during the late-luteal phase in pseudopregnant (PSP) rats. PSP rats received a subcutaneous injection of RU486 in sesame oil (5 mg/kg body weight) or sesame oil alone once a day between day 9 and day 11 of pseudopregnancy. Serial blood samples were collected on days 5, 9, 10, 11 and 12 and assayed for progesterone content. To examine the possible action of RU486 through a uterine and/or a pituitary (prolactin-dependent) mechanism, PSP rats and chronic hysterectomized PSP rats which had been hysterectomized before PSP induction received a subcutaneous injection of RU486 in sesame oil (5 mg/kg body weight), sesame oil alone, prolactin in 50% polyvinylpyrrolidone (15 IU/day), or RU486 and prolactin once a day between day 9 and day 11 of pseudopregnancy. Serial blood samples were collected on days 5, 9, 10 and 11 and assayed for progesterone content. Blood samples were also collected at 0400 h on day 12 and used for prolactin and progesterone determinations. To examine the direct effect of RU486 on corpus luteum and/or pituitary, hysterectomized rats underwent hypophysectomy and pituitary autotransplantation on dioestrus 1 and received a subcutaneous injection of RU486 in sesame oil or sesame oil alone for 3 days between day 21 and day 23 after surgery. Serial blood samples were collected on days 10, 21, 22, 23 and 24 and assayed for progesterone and prolactin contents. In ordinary PSP rats, serum progesterone levels were significantly (P < 0.01) lower in the RU486-treated group than in the control group (9 +/- 1 vs 53 +/- 7 ng/ml; mean +/- S.E.M.) on day 11. Serum prolactin levels at 0400 h on day 12 of pseudopregnancy were significantly (P < 0.05) lower in the RU486-treated group than in the control group (16 +/- 4 vs 154 +/- 44 ng/ml; mean +/- S.E.M.). The concomitant prolactin treatment reversed the luteolytic effects of RU486 on day 11 of pseudopregnancy. In hysterectomized PSP rats, RU486 also suppressed serum prolactin levels, and the concomitant prolactin treatment again reversed the luteolytic effects of RU486. In hysterectomized rats which were hypophysectomized and pituitary autotransplanted, RU486 treatment did not induce any significant changes in serum progesterone and prolactin levels. These results indicated that RU486 induced luteolysis during the late-luteal phase in PSP rats by suppressing prolactin secretion via a hypothalamic mechanism.
Animals↗
Effect of nicardipine, a calcium antagonist, on induction of peroxisomal enzymes by dehydroepiandrosterone sulfate in cultured rat hepatocytes.
We examined the effect of nicardipine, a calcium antagonist, on the induction of peroxisomal enzymes, such as acyl-CoA oxidase and carnitine acetyltransferase, by dehydroepiandrosterone sulfate (DHEAS) and clofibric acid (CPIB), in primary cultured rat hepatocytes. Peroxisomal beta-oxidation and carnitine acetyltransferase activities were increased 11- and 20-fold, respectively, after 5 days of treatment with DHEAS (40 microM). However, 60 microM nicardipine significantly suppressed the induction of both of these activities by DHEAS to about 2-fold that of the control. This suppression was found to be both dose- and time-dependent. Immunoblot and Northern blot analyses of acyl-CoA oxidase revealed that suppression by nicardipine of the induction of peroxisomal beta-oxidation activity would be responsible for an increase in the amount of mRNA. In addition, the manner in which nicardipine suppressed the induction of peroxisomal beta-oxidation and carnitine acetyltransferase activity, was similar to that of clofibric acid. These findings suggest that in the calcium-dependent pathway, the mechanism for the induction of peroxisomal enzymes by DHEAS is basically the same as that by clofibric acid, a typical peroxisome proliferator. The present results also support our previous hypothesis that calcium may play an important role in the induction of these enzymes by peroxisome proliferators.
Animals↗
[Mutagenicity studies of prulifloxacin (NM441) and the active metabolite (NM394)].
The mutagenicity of prulifloxacin, a new antibacterial agent, was investigated by the reverse mutation test in bacteria, the chromosomal aberration test in cultured cells, and the micronucleus test in mice. In addition, NM394, an active metabolite of prulifloxacin, was examined for mutagenicity in the chromosomal aberration test in cultured cells. The reverse mutation test was performed at dose range of 0.0078-0.25 micrograms/plate using Salmonella typhimurium strains (TA100, TA1535, TA98, and TA1537), and Escherichia coli (WP2uvrA). Prulifloxacin did not increase revertant colonies significantly in any of the test strains with or without metabolic activation system (S9 mix). The chromosomal aberration tests were carried out in cultured Chinese hamster lung cells (CHL/IU). Prulifloxacin increased aberrant cells without S9 mix, and NM394 also induced chromosomal aberrations. In human lymphocytes, no significant increases of the frequencies of cells with chromosomal aberrations were observed at dose range of 5-320 micrograms/ml with or without S9 mix. The micronucleus test was conducted at doses of 625-5000 mg/kg in the bone marrow cells of Slc : ddY male mice. There were no significant increases in the frequencies of micronucleated polychromatic erythrocytes.
Animals↗
High-level expression of Bacillus thuringiensis phosphatidylinositol-specific phospholipase C by the Bacillus brevis host-vector system.
We succeeded in hyperproduction of Bacillus thuringiensis phosphatidylinositol-specific phospholipase C (PIPLC), using a Bacillus brevis 47 expression system. The recombinant B. thuringiensis PIPLC was expressed under the control of the middle wall protein gene promoter in B. brevis expression vector pNU211. A large amount of recombinant PIPLC (0.4 g per liter culture) was secreted into the medium as a mature enzyme, and the enzymatic properties of purified recombinant PIPLC were similar to those of the enzyme from wild-type B. thuringiensis. This system provides a useful approach to the three-dimensional structure-function relationship of PIPLC.
Bacillus↗
Anesthesia induced in pigs by use of a combination of medetomidine, butorphanol, and ketamine and its reversal by administration of atipamezole.
OBJECTIVE: To develop an IM administrable anesthetic combination for pigs. DESIGN: Use of a combination of atropine, medetomidine, butorphanol, and ketamine (MB-K) was evaluated as an anesthetic regimen and compared with that of a combination of atropine, xylazine, butorphanol, and ketamine (XB-K). Cardiorespiratory effects of MB-K combination and use of atipamezole as a means of reversing anesthesia induced by MB-K were examined. ANIMALS: 18 castrated, mixed-breed, specific-pathogenfree pigs, aged 8 to 15 (mean, 12.1) weeks and weighing 14.5 to 26.0 (mean, 19.6) kg. were studied. PROCEDURE: Dosages of drugs used in this study were atropine, 25 micrograms/kg of body weight; medetomidine, 80 micrograms/kg; xylazine, 2 mg/kg; butorphanol, 200 micrograms/kg; ketamine, 10 mg/kg; and atipamezole, 240 micrograms/kg. RESULTS: MB-K combination proved to be more effective than XB-K combination as an anesthetic combination. After quick and smooth induction by IM administration, MB-K-induced anesthesia was sustained for 98.8 +/- 22.5 minutes (mean +/- SD, 47.4 +/- 16.5 minutes by XB-K) with accompanying muscular relaxation (91 +/- 18 minutes) and loss of pedal (82 +/- 24 minutes) and laryngeal (75 +/- 19 minutes) reflexes. Loss of these reflexes was of significantly longer duration than the loss induced by XB-K, enabled tracheal intubation, and, thus, supported major surgery for at least 30 minutes after induction. Recovery from MB-K-induced anesthesia was smooth. MB-K combination had a slight stimulative effect on cardiovascular status, and a significant depressant effect on blood gas and acid-base status, but these effects were within biologically acceptable limits. Oxygen consumption of pigs under MB-K-induced anesthesia decreased significantly. MB-K-induced anesthesia could be effectively and quickly reversed by IM or IV administration of atipamezole. CONCLUSIONS: The combination of medetomidine, butorphanol, and ketamine induces excellent surgical anesthesia in pigs, and results in moderate cardiorespiratory effects. A great advantage of the anesthetic regimen is that it can be effectively and quickly reversed by atipamezole. CLINICAL RELEVANCE: Medetomidine, butorphanol, and ketamine-induced anesthesia is available for short-term major surgery in pigs.
Adrenergic alpha-Antagonists↗
[Involvement of stimulatory effect of prostaglandin F2 alpha on superoxide radical production by macrophages in corpus luteum regression].
The effect of prostaglandin F2 alpha (PGF2 alpha) on superoxide radical production by macrophages was studied in pseudopregnant rats. Peritoneal macrophages prepared on day 7 or 13 of pseudopregnancy (psp) were incubated with various doses of PGF2 alpha for 90 min, and the production of superoxide radical was measured by the cytochrome C reduction method. PGF2 alpha significantly stimulated superoxide radical production by macrophages on day 13 of psp, but not on day 7 of psp. The pretreatment of macrophages with an inhibitor of protein kinase C (H7), Ca2+ channel blocker (Verapamil), Ca2+ chelators (EGTA, BAPTA), and an inhibitor of GTP-binding protein (pertussis toxin) prevented the stimulatory effects of PGF2 alpha on superoxide radical production. In conclusion, PGF2 alpha stimulated superoxide radical production by macrophages through the intracellular signal transduction pathway including activation of protein kinase C through the GTP-binding protein and Ca2+ influx, which would play important roles in the luteolytic process in psp rats.
Animals↗
[Epidural catheterization dose not meet our expectation].
According to the roentgenographically confirmed intervertebral space at which an epidural catheter was placed, 241 patients who underwent abdominal or orthopedic hip surgery were allocated into 3 groups. Groups A, B, and C received epidural catheterization at Th7-10, Th10-L1, and L1-4, respectively. In each group, we examined the intervertebral space, which the anesthesiologist who had placed epidural catheter had determined, and the one which had been confirmed roentgenographically. We also investigated the catheter movement during the postoperative period. Catheters were barely placed at the same intervertebral space which had been confirmed roentgenographically. Considering the iliac crest as a landmark of L3-4 intervertebral space, the puncture point agreed with the roentgenographically confirmed intervertebral space with a percentage of 33 in group A. The extent of agreement increased up to 47 and 55 percent, in groups B and C, respectively. In contrast, when we counted down from the cervical prominent vertebra, a landmark of C7, the agreement was better in group A (55%) than in group C (33%). In the postoperative period, catheters came out more frequently in groups A and B than in group C, resulting from the early ambulation in abdominal surgery groups. There results suggest that, to place the epidural catheter more properly, (1) we should start to count from the landmark which is close to the puncture point and (2) we should keep it in mind that catheters come out accidently in patients who are encouraged to ambulate in the early postoperative period.
Aged↗
[Intraoperative ST-T depression during extreme hemodilution].
A 45 year old woman undergoing a removal of cerebral arterio-venous malformation, suffered an unexpected massive bleeding. With transfusion of plasma constituents, her hemoglobin concentration decreased to about 5 g.dl-1, but her hemodynamic parameters remained unchanged. Electrocardiogram showed a depressed ST segment, indicating myocardial ischemia, when hemoglobin concentration decreased to 2.2 g.dl-1. Accompanied with the ECG change, her blood pressure fell down from 110/70 mmHg to 70/40 mmHg and an elevation of CVP was observed. With rapid transfusion of concentrated red cell and whole blood, hemodynamic parameters as well as ECG change were restored to normal. With hemodilutional myocardial ischemia which is caused by acute massive bleeding, hemoglobin concentration of about 2 g.dl-1 would be critical.
Anesthesia, General↗
[Eradication of Helicobacter pylori in patients with end-stage renal disease undergoing dialysis treatment].
The aim of the present study was to examine the efficacy and safety of combination therapy with amoxicillin (AMPC), lansoprazole, and plaunotol for the eradication of H. pylori in dialysis patients. The subjects consisted of 15 dialysis patients (10 men and 5 women, mean age of 56 +/- 2.4 years) in whom H. pylori was found in the stomach. H. pylori status was evaluated by histology, culture and rapid urease test with biopsy specimens of the gastric mucosa. The patients were treated with AMPC 500 mg once a day for 3 weeks, lansoprazole 30 mg once a day for 8 weeks and plaunotol 80 mg three times a day for 24 weeks. In addition, the concentrations of serum gastrin and gastric juice ammonia were measured. Fourteen patients completed the treatment schedule, while one discontinued treatment because of nausea and diarrhea. Among the 14 patients, H. pylori was eradicated in 11 without any side effects (eradication rate 78.6%). Concentrations of gastric juice ammonia and serum gastrin were reduced significantly in patients who became H. pylori-negative. The present study indicates that combination therapy with AMPC, lansoprazole and plaunotol is safe and efficient for the eradication of H. pylori in dialysis patients. The results also suggested that elevated concentrations of gastric juice ammonia and serum gastrin in dialysis patients can be attributed, at least in part, to H. pylori infection.
2-Pyridinylmethylsulfinylbenzimidazoles↗
Chronic retinal effects by ultraviolet irradiation, with special reference to superoxide dismutases.
Recently ultraviolet light (UV) reaching the Earth's surface has been gradually increasing in amounts by the destruction of the ozone layers. Large parts of UV are absorbed in the cornea and lens, and only a few amounts reached the retina; however, the effect on the retina is not fully elucidated. 38 rats were irradiated 0.5-5.0 J/cm2 UV from 6 to 50 times every 24 hours, and immunohistochemically and immunochemically for superoxide dismutases (SOD). Morphologically, the destruction of rod outer segments (ROS) and dissociation of cell membranes between the pigment epithelial cells (PE) were already observed by 6 times 0.5 J/cm2 UV irradiations. As the doses of UV increased, heterochromatins and lipid droplets increased in the PE. In normal retina, Cu/Zn SOD were mainly distributed from the inner limiting membrane (ILM) to the ganglion cell layer, and the PE; however, after 6 times 0.5 J/cm2 UV irradiations, the distribution became widened from inner to outer plexiform layer (OPL). At that time, the concentrations of Cu/Zn and Mn SOD increased in the retina. The present study reveals that the morphological damage caused by UV irradiation is observed in the ROS and PE, where no immunoreactivities could be detected to Cu/Zn and Mn SOD. However, morphological damage was not from the ILM to OPL, where the immunoreactivities to both Cu/Zn and Mn SOD were observed.
Animals↗
Analysis of shape and retractability of the prepuce in 603 Japanese boys.
PURPOSE: We evaluated preputial development in Japanese boys. MATERIALS AND METHODS: Preputial retractability and formation of a tight ring were evaluated in 603 Japanese boys 0 to 15 years old. RESULTS: The incidence of a completely retractable prepuce gradually increased from 0% at age 6 months to 62.9% by 11 to 15 years, while that of a tight ring decreased with age from 84.3 to 8.6%. Nine boys had balanoposthitis but none had a symptomatic urinary tract infection. CONCLUSIONS: Incomplete separation of the prepuce is common and normal in neonates and infants, and preputial separation progresses until adolescence. Awareness of these findings will eliminate unnecessary circumcision in boys.
Adolescent↗