Lattice expansion of clathrate hydrates of methane mixtures and natural gas.
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Carbon Dioxide↗
Biomedical subjects
Nobuo Takahashi
Publications and source records attributed to Nobuo Takahashi.
Prevalence of gastric cancer decreases with age in long-living elderly in Japan, possibly due to changes in Helicobacter pylori infection status.
OBJECTIVES: The prevalence of Helicobacter pylori (Hp) infection and the development of gastric cancer are both believed to increase with age in Japan. However, no studies have investigated people older than 65 years in detail. In this study, we investigated the prevalence of Hp infection and gastric cancer in the elderly, and analyzed the influence of both factors on longevity. METHODS: All patients investigated were 65 years old and over. A total of 1877 autopsy cases were used to investigate the prevalence of gastric cancer and colonic cancer. Serum samples were obtained from 644 patients with dyspepsia and analyzed for Hp-IgG antibodies. Of these 644 patients, 63 underwent upper gastrointestinal endoscopies. Five biopsies were obtained and evaluated for the following morphological variables: neutrophils, mononuclear cell, atrophy, and intestinal metaplasia. Hp infection was evaluated histologically and with the (13)C-urea breath test. RESULTS: The prevalence of gastric cancer was significantly lower in subjects older than 85 years. The positive rate of serum Hp-IgG, and Hp infection as detected histologically and by the (13)C-urea breath test, also decreased with age. In Hp(+) patients, the neutrophil score significantly decreased with age. In Hp(-) patients, however, the intestinal metaplasia score significantly increased with age. CONCLUSIONS: The non-infection of Hp itself is not related to longevity in Japanese elderly, because even Hp(-) patients appear to have been infected previously with Hp. The lower prevalence of gastric cancer in the elderly may be due to the disappearance of Hp colonization, which may contribute to longevity in Japanese elderly.
Age Factors↗
[Intraocular penetration of cefotiam hydrochloride, a kind of cephalosporin after filtration surgery in rabbit eyes].
PURPOSE: In this study, we measured the cefotiam dihydrochloride (CTM) concentration in ocular tissue after filtration surgery in rabbit eyes. METHODS: CTM (20 mg/kg body weight) was administered intravenously 30 min before filtration surgery which was performed by double flap procedure on the right eyes of white rabbits. The aqueous humor and serum were extracted at 10 min after surgery and at 30 min, 60 min, and 120 min. Drug concentration in all of the specimens was measured by high performance liquid chromatography (HP-LC). RESULT: The CTM concentrations of aqueous humor in the nonoperated eyes were 0.44 +/- 0.16(mean +/- standard deviation) microg/ml (n = 4) (40 min after intravenous dosage), 0.36 +/- 0.17microg/ml (n = 4) (60 min after intravenous dosage), 0.38 +/- 0.34, microg/ml(n = 3) (90min after intravenous dosage) and 0.27 +/- 0.10 microg/ml (n = 5) (150 min after intravenous dosage). In contrast, CTM concentration in the aqueous humor of the operated eyes was 2.4 +/- 0.95 microg/ml (n = 4) at 10 min after surgery (40 min after intravenous dosage), 2.11 +/- 1.10 microg/ml (n = 4) at 30 min after surgery (60 min after intravenous dosage), 1.18 +/- 0.78 microg/ml (n = 4) at 60 min after surgery (90 min after intravenous dosage) and 0.47 +/- 0.1 microg/ml (n = 5) at 120 min after surgery (150 min after intravenous dosage). The intraocular penetration of CTM at 10 min and at 120 min after filtration surgery was significantly higher in comparison with the drug concentration in the nonoperated eyes (p < 0.05). CONCLUSION: The intraocular penetration of CTM after filtration surgery was much higher in comparison with the drug concentration in the nonoperated eyes. These results may be useful to predict the intraocular penetration of CTM in human eyes after filtration surgery.
Animals↗
Evaluation of early gastric mucosal permeability induced by central thyrotropin-releasing hormone administration.
Accumulating evidence suggests that central thyrotropin-releasing hormone (TRH) administration induces gastric erosion 4 h after administration through the vagal nerves. However, early changes in the gastric mucosa during these 4 h have not been described. To assess early changes in the gastric mucosa after intracisternal injection of a stable TRH analog, pGlu-His-(3,3'-dimethyl)-ProNH2 (RX-77368), we measured the blood-to-lumen 51Cr-labeled EDTA clearance and examined the effects of vagotomy, atropine, omeprazole, and hydrochloric acid (HCl) on RX-77368-induced mucosal permeability. A cytoprotective dose of RX-77368 (1.5 ng) did not increase mucosal permeability. However, higher doses significantly increased mucosal permeability. Permeability peaked within 20 min and gradually returned to control levels in response to a 15-ng dose (submaximal dose). Increased mucosal permeability was not recovered after a 150-ng dose (ulcerogenic dose). This increase in permeability was inhibited by vagotomy or atropine. Intragastric perfusion with HCl did not change the RX-77368 (15 ng)-induced increase in permeability, but completely inhibited the recovery of permeability after the peak. Pretreatment with omeprazole did not change the RX-77368 (15 ng)-induced increase in permeability, but quickened the recovery of permeability after the peak. These data indicate that the RX-77368-induced increase in permeability is mediated via the vagal-cholinergic pathway and is not a secondary change in RX-77368-induced acid secretion. Inhibited recovery of permeability on exposure to an ulcerogenic RX-77368 dose or on exposure to HCl plus a submaximal dose of RX-77368 may be crucial for the induction of gastric mucosal lesions by central RX-77368 administration.
Animals↗
Biliary cystadenocarcinoma followed up as benign cystadenoma for 10 years.
We describe a case of biliary cystadenocarcinoma that showed a longterm clinical course. A 69-year-old Japanese man was admitted to our hospital because of abdominal discomfort. The patient had been diagnosed with benign cystadenoma of the liver at another hospital in 1987 and had been followed up for 10 years. Abdominal ultrasonography (US) and computed tomography (CT) scan demonstrated a unilocular cystic lesion, which included multiple conspicuous papillary protrusions in the left hepatic lobe. Left lateral segmentectomy was performed, and intraoperative cholangiography revealed a communication between the cystic tumor and intrahepatic bile duct. The tumor contained clear mucinous fluid and enfolded multiple yellowish papillary projections on the cystic wall. Histological examination showed the tumor to be biliary cystadenocarcinoma. The patient is doing well 4 years after the operation.
Abdomen↗
Nuclear localization of alkaline phosphatase in cultured human cancer cells.
The nucleolar localization of alkaline phosphatase (ALPase) was observed by electron microscopic cytochemistry. The culture cells used in this study were normal human cells (fibroblast, WI-38) and human cancer cells (hepatocellular carcinoma, Hep-G2; malignant melanoma, A-375; pancreatic carcinoma, BxPC-3). Cultured cells in almost all strains contained high ALPase activity in the nucleolus, and the localization of ALPase changed during the cell cycle stages. The pattern of ALPase localization during the interphase was divided into three groups: cytoplasmic type, nucleus type, and both types. Moreover, at the mitotic phase, the reaction products were observed on the chromosome. In the cultured malignant melanoma cells, the appearance ratio of ALPase reaction products on the nucleolus (33.9%) showed a higher ratio compared with normal cultured fibroblasts (6.3%). This phenomenon suggests that the high level of the ALPase reaction product may be related to the high level of proliferation of cancer cells.
Alkaline Phosphatase↗
High prevalence of nuclear cataract in the population of tropical and subtropical areas.
The authors have conducted cataract epidemiological studies in four climatically and racially different places and compared the data. The survey places were Noto and Amami in Japan, Reykjavik in Iceland, and Singapore. The evaluation and grading of lens opacities were done using graphic analysis of Scheimpflug and retro-illumination images. The prevalence of nuclear opacity was extremely high in the Singapore group, followed by Amami. The main type of lens opacity was nuclear in the Singapore group and cortical in the Noto and Icelandic groups. The characteristic lens opacity in Amami was in between the above two groups. No significant difference was seen in the prevalence of nuclear opacity between males and females in any of the groups. Although the common factors of the living conditions in the subjects with a high prevalence of nuclear opacity appear to be high UV exposure and high ambient temperature, future investigations should be made to disclose the possible cause.
Aged↗
Environmental temperature and cataract progression in experimental rat cataract models.
PURPOSE: To clarify whether or not ambient temperature relates to cataract development or the progression of cataract formation. MATERIALS AND METHODS: 36 Brown Norway rats were divided into two groups, a high-temperature (35 +/- 2 degrees C, H = high) breeding group and a regular-temperature (24 +/- 2 degrees C, L = low) group. Each group was further divided into an experimentally induced diabetic cataract subgroup (50 mg/kg streptozotocin, DM), an ultraviolet B exposure-induced cataract subgroup (200 mJ/cm2, UV), and a normal control subgroup (C = control). Slit-lamp microscopy and an anterior image analysis system (EAS-1000) were used to evaluate lens changes. RESULTS: Both the HC and HUV groups in the 35 degrees C conditions showed higher light scattering than that of the 24 degrees C conditions (LC and LUV) 3 weeks after the start of the experiment. Nine weeks after the start of the experiment, all the rats of the UV subgroups (HUV and LUV) developed anterior subcapsular cataract. The temperature did not have much influence on the progression of the UV-B-induced cataract. From 18 days after the start of the experiment, the HC subgroup showed a wider light scattering area than the LC. An increase in abnormal nuclear scattering light in the crystalline lens of group HC was found in 9 weeks after the start of the experiment, and at the end of the experiment (78 weeks later), dense abnormal nuclear light scattering was found including the prenuclear area. In contrast, the HDM group in the 35 degrees C conditions showed slower cataract progression than that of the LDM group at 24 degrees C room temperature. CONCLUSIONS: Although further experiments are necessary before we can draw any conclusions about temperature and nuclear changes, paying attention to the effects of temperature on the lens is worthwhile.
Animals↗
Low vitamin E level as a subliminal risk factor in a rat model of prednisolone-induced cataract.
PURPOSE: To investigate the relationship between vitamin E deficiency and prednisolone-induced cataract formation, long-term examination of lens changes was performed in rats under the condition of vitamin E deficiency or supplementation and administration of prednisolone. METHODS: Rats were divided into six groups: normal chow (N), vitamin E-deficient chow (ED), normal chow with prednisolone instillation (NP), vitamin E-deficient chow with prednisolone instillation (EDP), NP treatment with vitamin E supplementation (NP+VE), and EDP treatment with vitamin E supplementation (EDP+VE). Prednisolone (1 mg/kg small middle dot d) and vitamin E (5%; 10 microL per administration per eye, 1 mg/kg small middle dot d) were applied in the cul-de-sac. Lens changes were documented and analyzed. Vitamin E status was confirmed by measuring peroxide-induced hemolysis. RESULTS: After 15 months, 91.7% of the eyes in the EDP group showed development of anterior and posterior cortical cataracts. Supplementation with vitamin E significantly reduced cataract formation (to 38.9% of eyes). Neither a vitamin E-deficient diet nor prednisolone treatment alone significantly increased cataract formation. Hemolysis-susceptibility tests confirmed the expected vitamin E status of rats fed vitamin E-deficient chow and rats supplemented with eye drops containing vitamin E. CONCLUSIONS: Vitamin E deficiency and long-term prednisolone treatment together cause cataracts. Singly, however, both conditions are subliminal cataractogenic risk factors.
Animals↗
The effect of the corneal epithelium on the intraocular penetration of fluoroquinolone ophthalmic solution.
PURPOSE: Pharmacokinetic studies of antibacterial agents for infectious eye diseases have usually been performed on normal rabbit eyes. In this study, the intraocular penetration of fluoroquinolone ophthalmic solutions was determined in normal rabbit eyes and in rabbit eyes that had the corneal epithelium intentionally removed. METHODS: We determined the intraocular penetration of ofloxacin (OFLX), levofloxacin (LVFX), and norfloxacin (NFLX), fluoroquinolone ophthalmic solutions that are already on the market and undergoing clinical studies, by injecting 50 microl of each solution into the cul-de-sacs of rabbit eyes three times at 15-min intervals. The drug concentration at 10, 30, 60, 120, and 240 min after final instillation was determined by high-performance liquid chromatography. RESULTS: The maximum concentration in the aqueous humor of normal rabbit eyes was 2.09 +/- 1.56 microg/ml (60 min, OFLX), 2.57 +/- 1.00 microg/ml (30 min, LVFX), and 0.42 +/- 0.12 microg/ml (120 min, NFLX). The drug concentration in the aqueous humor of eyes with intentionally removed corneal epithelium was 12.50 +/- 5.62 microg/ml (30 min, OFLX), 9.02 +/- 2.45 microg/ml (60 min, LVFX), and 8.54 +/- 5.17 microg/ml (30 min, NFLX). The drug penetration of the eye drops into eyes with removed corneal epithelium was around 6 times (OFLX), 3.5 times (LVFX), and 20 times (NFLX) higher than the penetration into the eye with normal cornea. CONCLUSION: Among the pharmacokinetic parameters of the three ophthalmic solutions according to the one-compartment model, the maximum concentration in the aqueous and the area under the concentration-time curve in the aqueous tended to be higher in the eyes with intentionally removed corneal epithelia than in those with normal corneas.
Animals↗
A novel combination treatment of chlorhexidine gluconate, natamycin (pimaricin) and debridement for a Acanthamoeba keratitis.
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Acanthamoeba Keratitis↗
Early manifestation of vogt-koyanagi-harada disease as unilateral posterior scleritis.
PURPOSE: To describe a patient with an initial diagnosis of unilateral posterior scleritis who developed bilateral Vogt-Koyanagi-Harada (VKH) disease 12 months later. CASE: A 38-year-old woman was diagnosed with posterior scleritis in her right eye at successive examinations. The left eye showed no signs of ocular inflammation. OBSERVATIONS: Her right eye developed a second attack of posterior scleritis 3 months after the initial diagnosis. Twelve months after the first incident, granulomatous uveitis and sunset glow fundus were observed in both eyes. At the same time, lymphocytosis was found in the cerebrospinal fluid, and she was HLA DR-4-positive. In addition, poliosis was noted. CONCLUSIONS: The final diagnosis was primarily VKH disease with presenting signs and symptoms of unilateral posterior scleritis. We therefore recommend that when following a patient with posterior scleritis include VKH disease in the differential diagnosis.
Adult↗
Diagnostic potential of tear proteomic patterns in Sjögren's syndrome.
Histological and functional changes of the lacrimal gland might be reflected in proteomic patterns in tear fluids. In this study, we carried out a determination of the disease biomarkers in tear fluid for Sjögren's syndrome (SS) and a performance of noninvasive diagnostic test based on the proteomic patterns. Thirty-one SS patients and 57 control subjects were enrolled to this study. Their details were 23 cases with primary SS, 8 with secondary SS, 14 with dry eyes, 22 with miscellaneous ocular diseases, and 21 of healthy volunteers. Protein profiling in tear fluids was identified by surface enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS). Multiple protein changes were reproducibly detected in the primary SS group, including 10 potential novel biomarkers. Seven of the biomarkers (2094, 2743, 14191, 14702, 16429, 17453, 17792 m/z) were down-regulated and 3 biomarkers (3483, 4972, 10860 m/z) were up-regulated in primary SS group, comparing to the protein profiles of control subjects. When cutoff value of SS down-score was set less than 0.5, this result yielded 87% sensitivity and 100% specificity. The positive predictive value for this sample set was 100%. There was a significant inverse correlation between SS down-scores and epithelial damages of the ocular surface in primary SS patients. These findings support the potential of proteomic pattern technology in tear fluids as the noninvasive diagnostic test for primary SS.
Biomarkers↗
Factors affecting ventricular function and survival after partial left ventriculectomy.
BACKGROUND: Partial left ventriculectomy (PLV) helps some patients but is deleterious in others. Selection of patients who will benefit from PLV, and exclusion of those who will not is necessary for safe and effective application of the procedure. METHODS: Sixty-nine consecutive patients who underwent PLV were monitored with pressure-volume relationship analyses, Doppler echocardiography, and histopathologic studies of excised myocardium. These parameters were correlated with postoperative stroke volume (SV, ml), cardiac output (CO, L/min), ventricular function (improved, no change, or deteriorated), and postoperative course (duration of survival and/or hospital discharge). RESULTS: Positive responders (n = 36) with increased SV at reduced end diastolic pressure had significantly larger preoperative end-systolic dimension, smaller SV, and less stroke work with milder fibrosis than non- or negative responders (n = 33). In multivariate analyses, poor preoperative hemodynamics were associated with increased SV and CO, but these improvements did not lead to improved survival. Postoperative survival was negatively affected by larger preoperative left ventricular end-diastolic volume and larger excised-muscle-weight. Milder fibrosis and thicker excised wall were consistently related to improved ventricular function and survival. CONCLUSION: Although effects of PLV are related to preoperative status, factors affecting postoperative ventricular function and survival were often discordant. While poor preoperative ventricular function was associated with functional improvement without survival benefit, milder fibrosis, thicker excised wall and less myocardial resection were positive contributors to improved ventricular function, discharge, and survival. Preoperative evaluation with more cases and variables are needed to identify patients more likely to benefit from PLV.
Adult↗
Predicting postoperative anterior chamber depth in cataract patients using Scheimpflug slit photography.
PURPOSE: To predict the postoperative anterior chamber (AC) depth from the preoperative in situ position of the lens central clear zone (CCZ) using Scheimpflug slit photography. METHODS: 111 eyes of 78 cases that underwent phacoemulsification and intraocular lens (IOL) implantation were examined. 748 eyes of 383 healthy subjects with transparent lenses were used as the control. Scheimpflug slit photography was done under maximal mydriasis, and biometry was performed on the photographs. Two types of acrylic IOLs (MA30BA and MA60BM, both from Alcon) were used in this study. The preoperative AC depth (L1), the distance between the anterior lens capsule and lens CCZ (L2) and the postoperative AC depth (I1) were determined. I2, the predicted postoperative AC depth, was then determined from a linear regression of L1 + L2 and I1. RESULTS: L2 thickened by 0.014 mm/year, and L1 decreased by 0.016 mm/year in the transparent lenses. L1 + L2 changed little with aging in both cataractous and transparent lenses. L1 + L2 and I1 showed a linear correlation with r = 0.80 in the MA30BA and r = 0.77 in the MA60BM groups. The mean error values between I1 and I2 were 0.095 +/- 0.096 and 0.123 +/- 0.114 mm in MA30BA and MA60BM, respectively. The error between I1 and I2 was within +/- 0.17 and +/- 0.33 mm or less in 72.9 and 91.5% of MA30BA and in 82.7 and 96.2% of MA60BM. In contrast, the error between I2 and I1 when calculated using the SRK/T formula was much larger - in excess of +/- 0.33 mm in 38.7% of the eyes. CONCLUSIONS: L1 + L2 changes little with aging and is considered a useful marker of the position of the crystalline lens in situ. There was a high correlation between I1 and L1 + L2. These allow a far more accurate prediction of I1 than previous methods. In combination with the conventional regression formula and ray tracing, a highly accurate IOL power calculation can be attained.
Aged↗