Effects of hypoxia on the visual pathway in rabbits.
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Animals↗
Biomedical subjects
S Takagi
Publications and source records attributed to S Takagi.
Reconstruction of the frontal sinus and frontofacial skeleton with hydroxyapatite cement.
OBJECTIVE: To evaluate the efficacy of a newly developed biomaterial, hydroxyapatite cement, for use in frontal sinus and anterior craniofacial skeletal reconstruction. DESIGN: A nonrandomized patient cohort that was compared with historical controls of standard treatment with methyl methacrylate implants. SETTING: Craniofacial reconstructive surgery services at 3 referral health care centers. Eligible patients had frontal-cranial defects limited to a maximum size of 25 cm2. Patients were randomly selected volunteers with preexistent, acute traumatic or acute surgically induced defects of the frontal sinus and anterior craniofacial skeleton. All patients provided informed consent, and the study was approved by the 3 institutional review boards. Forty patients underwent reconstruction of defects of the anterior craniofacial region, and 38 of these patients were evaluable at 24 months. MAIN OUTCOME MEASURES: Hydroxyapatite cement was used to reconstruct full-thickness anterior craniofacial skull defects. Standard surgical techniques were used to place all implants. The primary outcome measurement was maintenance of implant volume determined at 24 months by computed tomography and clinical examination. Secondary outcome measures included incidence of complications and infections necessitating implant removal. RESULTS: Of the 38 evaluable patients, 31 had successful reconstructions at the end of the study, for an overall success of 82% for frontal sinus and frontofacial region reconstruction. Seven patients underwent explantation, 5 for surgical access to the site. Two implants were removed because of infection in the wound, for an overall incidence of approximately 5%. Explant biopsy specimens confirmed implant osseointegration and vascularization. CONCLUSIONS: Hydroxyapatite cement successfully reconstructs full-thickness defects of the frontal sinus and frontofacial region at 24 months. Hydroxyapatite cement appears to be superior to acrylic implants for frontal-cranial reconstruction and by allowing implant osseointegration with improved biocompatibility.
Adult↗
Mild but prolonged elevation of serum angiotensin converting enzyme (ACE) activity in alcoholics.
Serum activity of angiotensin converting enzyme (ACE) was serially measured in 47 hospitalized chronic alcoholics with liver disease. Compared to healthy controls, ACE activity, on admission, in the serum of alcoholics was significantly elevated (42.5 +/- 16.6 U/ml vs. 32.4 +/- 9.6 U/ml; p less than 0.005). About 36% of the patients had an elevated ACE level exceeding an upper normal value of 42 U/ml (mean +/- SD). In contrast to the rapid normalization of such enzymes as aspartate transaminase (AST), alanine transaminase (ALT) and lactic dehydrogenase (LDH) which represent parenchymal liver cell injury, the activity of ACE remained elevated over a period of 4 weeks even with abstinence. The serum level of ACE was significantly correlated with levels of alkaline phosphatase, gamma-glutamyltranspeptidase and monoamine oxidase, but not with those of AST, ALT and LDH. These data suggest increased ACE activity in alcoholics may be related to the influence of chronic consumption of alcohol on hepatic nonparenchymal systems.
Adult↗
Increase in mitochondrial GOT (m-GOT) activity after chronic alcohol consumption: clinical and experimental observations.
In order to clarify the origin and the mechanism of increased serum activity of glutamic oxalacetic transaminase (GOT) in chronic alcoholics, clinical and experimental investigations were carried out. Mitochondrial (m-GOT) and cytosolic GOT (c-GOT) isoenzymes were separated chromatographically by using a mini-column packed with Sephadex A50. Sixty percent of 63 alcoholics had elevated serum GOT. The m-GOT activity in alcoholics with total serum GOT activity of over 50 Karmen Units was 17.2 +/- 1.6 K.U. and the m-GOT/GOT ratio was the highest when compared to those in non-alcoholic liver diseases. In in vitro study, six hours of incubation of isolated hepatocytes from rats fed ethanol chronically resulted in an increased leakage of m-GOT into the incubation medium and also showed a tendency of a higher m-GOT/GOT ratio than that from control rats. The m-GOT activity thus released into the medium showed a highly significant inverse correlation with the viability of hepatocytes. These data suggest that m-GOT substantially contributes to an increased serum GOT often observed in chronic alcoholics.
Alcoholism↗
Gastrectomy enhances vulnerability to the development of alcoholism.
A history of gastrectomy was more frequently encountered in Japanese male alcoholics (9.7%, 47/486) than in male employee populations of two large companies (0.8%, 36/4,381, p < 0.001, and 0.6%, 6/950, p < 0.001). Gastrectomized men are known to achieve a higher blood ethanol level after the ingestion of the equal amount of ethanol than nongastrectomized men. To examine whether or not gastrectomy was responsible for the subsequent development of alcohol dependence, 47 gastrectomized alcoholics were compared with 47 age-matched nongastrectomized alcoholics. The mean lifetime duration of heavy drinking (> 120 g ethanol/day) was shorter in the former than in the latter (11 +/- 10 years vs. 16 +/- 9, p < 0.05), and the mean lifetime cumulative ethanol consumption level also smaller (834 +/- 497 kg vs. 1047 +/- 508, p < 0.05). The majority of gastrectomized patients (30/47) had no history of problem drinking before gastrectomy. The daily consumption was rapidly increased within 5 years after gastrectomy in 18 of 38 habitual drinkers (47%). Seven of the remaining nine nonhabitual drinkers (78%) became habitual drinkers and alcoholics within a short period of time (7 +/- 4 years), though with low lifetime cumulative consumption (< 400 kg). The incidence of disorders of the central and peripheral nervous systems observed did not differ between the two groups, except for frequent alcoholic blackouts reported in the gastrectomized patients. In conclusion, the majority of the gastrectomized patients changed their drinking habits after gastrectomy and developed alcohol dependence. They did not require as much lifetime cumulative ethanol as nongastrectomized patients to become ethanol dependent.
Adult↗
Neuroimaging on delayed postanoxic encephalopathy with lesions localized in basal ganglia.
A 59-year-old woman suffered from prolonged hypotension with myocardial infarction. Sixteen days after the episode, she showed bradykinesia, gait disturbance, and postural tremor. MRI revealed low signa intensities in the bilateral caudate nuclei and putamen on the T1-weighted image and high signal intensities on the T2-weighted image. PET with 18F-FDG revealed a severe decrease in glucose metabolism in bilateral basal ganglia. It is concluded that prolonged hypotension may induce localized delayed anoxic lesions in basal ganglia.
Basal Ganglia↗
Studies on iridoid-related compounds, II. The structure and antimicrobial activity of aglucones of galioside and gardenoside.
Enzymatic hydrolysis of galioside (1) and gardenoside (2), epimer of 1 at C-8 position, provided the antimicrobially active aglucone (3) and the inactive 6(a,b), while acid treatment of 2 gave scandoside methylester (8), deacetylasperulosidic acid methylester (9) and 10-dehydogeniposide (10).
Acetylation↗
Alcohol-related sudden death with hepatic fatty metamorphosis: a comprehensive clinicopathological inquiry into its pathogenesis.
To clarify the pathogenesis of the widely known but obscure syndrome of sudden death with hepatic fatty metamorphosis observed in alcohol abusers, we have scrutinized both the clinical and pathological data of 11 subjects who died under such circumstances between 1987 and 1993. Death followed several days of uninterrupted drinking often with little dietary intake. The notable clinical features on arrival at the emergency room were disturbance of consciousness (11/11), hypotension (4/6), hypothermia (3/5), hypoglycaemia (8/11), metabolic acidosis (6/6), renal dysfunction (11/11), and hyperammonaemia (5/5). The common hepatic pathology was the extensive appearance of numerous microvesicular fatty droplets in the hepatocytes together with varying degrees of macrovesicular fatty change; four subjects had an underlying cirrhosis. Death undoubtedly results from a variety of metabolic disturbances triggered by the combination of massive ethanol intake and starvation. The appearance of extensive microvesicular fatty change superimposed on macrovesicular fatty change was considered to be an associated phenomenon.
Adult↗
Microradiography with an x-ray image magnifier: application to dental hard tissue.
The superior spatial resolution obtained with parallel-beam microradiography over conventional contact microradiography has allowed us to image microstructural features of dental hard tissue not previously reported. Our efforts to extend these techniques to provide a real-time capability for viewing in situ demineralization and remineralization effects, at and below the 1-micron level, have resulted in an instrument with several novel and unique features. Using a synchrotron radiation source of x rays and diffraction image magnification, we are now able to change magnification at will (x-ray zoom lens). In addition, the energy range over which the instrument operates gives one considerable flexibility in optimizing image contrast. The techniques of parallel-beam microradiography, and diffraction image magnification are applicable to problems in many other areas of science. Using examples within dental research, the uniqueness and versatility of these new techniques are discussed.
Dental Enamel↗
Effect of tooth-bound fluoride on enamel demineralization/ remineralization in vitro.
The effect of tooth-bound fluoride (F) on enamel caries formation was investigated under the condition that loosely bound F was essentially absent. Eighteen thin enamel sections, prepared from the lingual or buccal surfaces of extracted human molars, were embedded in acrylic resin with the enamel surfaces exposed. The sections were placed in a pH 7 remineralizing solution (RS; 1.2 mmol/l Ca, 0.72 mmol/l P, 30 mmol/l KCl, 50 mmol/l HEPES) for 5 days, and were randomly divided into 3 groups: (1) control group that received no treatment, (2) acidulated phosphate fluoride (APF) group that received 5 cycles of a 4 min treatment with APF gel followed by immersion in the RS for 2 days (RS changed daily) and (3) dicalcium phosphate dihydrate (DCPD) - APF group that received 5 cycles of a 4-min pH 2.1 DCPD-forming solution followed by 4 min APF gel and then placed in the RS for 2 days. After the treatment cycles, the sections were washed in a constant composition F titration system to remove loosely bound F. An in vitro model, which consisted of cycles of de- (6 h) and remineralization (18 h) each day for 5 days, was used to produce caries-like lesions in the specimens. The DeltaZ (mineral loss) values, measured by quantitative microradiography, of the lesions formed in the three groups were (mean +/- standard deviation; n = 6) 91.2+/-12.3 microm for the control group, 41.3+/-10.1 microm for the APF group and 21.2+/-4.8 microm for the DCPD-APF group. The same system produced lesions in untreated shark enamel with a mean DeltaZ of 4.4+/-0.3 microm (n = 12). One-way fixed-effects ANOVA indicated that mineral loss was significantly different among the different groups (p<0.05). The results showed that enamel resistance to lesion formation increased with increasing tooth-bound F content. Shark enamel was much more resistant to demineralization than human enamel.
Acidulated Phosphate Fluoride↗
Surgical treatment for dysphagia of neuromuscular origin.
There are a number of surgical procedures which can be used to improve swallowing in selected dysphagic patients. These include: vocal fold augmentation or medialization, cricopharyngeal myotomy, laryngeal suspension, intrahyoid myotomy, lateral thyrolaminectomy and tracheoesophageal separation procedures. This article describes these various procedures and their appropriate application to selected dysphagic patients. Results of a study of the location of the recurrent laryngeal nerve in relation to the cricopharyngeal muscle are also presented.
Deglutition Disorders↗
Initial symptoms of Parkinson's disease with elderly onset.
BACKGROUND/OBJECTIVE: As the incidence of Parkinson's disease (PD) is related to aging, we consider it important to determine how the initial symptoms change with age in order to diagnose early elderly cases of PD accurately. METHODS: 84 patients (age at onset 70.7+/-9.0 years; mean +/-1 SD) were studied to see whether the initial symptoms change according to age. RESULTS: The prevalence of resting tremor was significantly lower in patients of advanced age (p = 0.041). In contrast, the incidence of postural and gait disorders increased significantly with aging (p = 0.032). The prevalences of rigidity and kinetic disorders, which are important clinical features of PD, were not influenced by aging. CONCLUSION: These findings suggest that the cause of PD is not related to the aging process itself, since the prevalences of all symptoms were not influenced by aging. Knowledge of the prevalence of the initial symptoms of PD may contribute to the accurate diagnosis in early and elderly cases.
Adult↗
Effect of a low-fluoride-content, two-component rinse on fluoride uptake and on de--and remineralization of enamel lesions: an in vitro study.
The effect of calcium (Ca) concentrations and added ethanol on fluoride (F) depositions by experimental two-component rinses, each consisting of a Ca-containing and an F-containing component, was evaluated in an in vitro system. Among the tested rinses, a 3 mmol/l F two-component rinse with 200 mmol/l Ca and 10% v/v ethanol was found to produce the greatest F deposition relative to the F concentration in the rinse. Specifically, this rinse produced an F deposition that was about 7 times greater than a conventional 13.2-mmol/l sodium fluoride (NaF) rinse. In a second experiment, an in vitro pH cycling model was used to evaluate the potential anti-caries effects of 4 rinses: (1) placebo rinse (no F), (2) 13.2-mmol/l NaF rinse, (3) 52.6-mmol/l NaF rinse, and (4) the 3-mmol/l F two-component rinse in a 7-day in vitro pH cycling model. The changes in lesion mineral contents, delta(DeltaZ), as assessed by quantitative microradiographic measurements, were as follows [mean +/- standard deviation, n = 10]: (1) 72.5+/-10.2 microm, (2) 43.4+/-5.6 microm, (3) 17.3+/-10.2 microm and (4) 45.3+/-5.2 microm. These results showed that the 3-mmol/l F two-component rinse produced the same (p>0.05) protection against demineralization as did the 13.2-mmol/l NaF rinse which had 4 times the fluoride content. The results suggest that it is possible to formulate an effective low-F two-component rinse.
Analysis of Variance↗
Remineralization effect of a low-concentration fluoride rinse in an intraoral model.
A previous study showed that a sodium hexafluorosilicate-calcium chloride-based two-solution fluoride (F) rinse containing 6 mmol/l of F was more effective than a 12 mmol/l F sodium fluoride rinse in depositing F on tooth surfaces and increasing oral F levels. The present study compared the remineralization effects of these two rinses in an intraoral de- and remineralization model. The results showed that the 6 mmol/l F two-solution rinse produced greater remineralization in increasing lesion mineral contents and reducing lesion depths. The results demonstrated that the effectiveness of an F regimen depends less on the F dose and more on the ability of the treatment to utilize F efficiently for remineralization.
Analysis of Variance↗
Modification of cerebrovascular CO2 reactivity by inhibition of dopamine beta-hydroxylase.
The influence of sympathetic nervous activity on cerebral circulation and cerebrovascular CO2 reactivity was investigated through inhibition of dopamine beta-hydroxylase (DBH). A PO2 electrode, a PCO2 electrode and a plate-type thermocouple-flowmeter were placed on the pial surface of the cat brain. Cerebrocortical PO2, PCO2, cerebrocortical blood flow and arterial blood pressure were continuously recorded before, during and after intracarotid infusion of 10 mg/kg of fusaric acid, a potent DBH inhibitor. The effects of 5% CO2 inhalation and hyperventilation were measured before and after the inhibition of DBH. Following the intracarotid infusion of fusaric acid, cerebrocortical PO2 and cerebrocortical blood flow increased significantly. After the inhibition of DBH, the degree of the increase in cerebrocortical PO2 during 5% CO2 inhalation was enhanced while the degree of the decrease in cerebrocortical PO2 during hyperventilation did not show any significant change. The cerebral vasodilatation caused by fusaric acid suggests that the sympathetic nervous system takes part in the resting tone of cerebral blood vessels. The increase in the cerebrovascular CO2 reactivity produced by the inhibition of DBH suggests that the sympathetic nervous system modifies cerebrovascular CO2 reactivity.
Animals↗
Internal carotid occlusion: volume of cerebral infarction, clinical findings, and prognosis.
Clinical, angiographic and computed tomographic (CT) findings, and the volume of an infarcted area as estimated from tomograms, were evaluated in 26 patients with proven, unilateral, internal carotid artery (ICA) occlusion. The volume of cerebral infarction (CI) ranged from 0 cm3 to 200 cm3. It was shown that the CI volume in the group of patients with good collateral flow was smaller than that in the group with poor or no collaterals (p less than 0.05). It was also found that the smaller the volume of infarcted area, the better the patient's ability to carry out activities of daily living (ADL). The volume of infarction in patients without disturbance of consciousness was smaller than in patients with such disturbance. Thirteen of 15 patients with infarction of less than 50 cm3 eventually showed good ADL. The patients with a deeply located infarction had a good prognosis and no disturbance of consciousness. In patients with superficial infarction there were relationship between the volume of infarction and prognosis, and between the volume and disturbance of consciousness. It is concluded that estimation of the volume of an infarcted area is important in assessing the clinical state and prognosis in patients with ICA occlusion.
Adult↗
Water extraction fraction and permeability-surface product after intravenous injection in rats.
A quantitative method has been developed to measure the water extraction fraction of rat brain after successive intravenous bolus injections of [15O]water and [11C]butanol based on a mathematical equation developed by the authors. This new method is noninvasive to the brain or craniocervical large vessels and does not require sacrifice of the rats. Arterial concentration curves and total head counts were measured in 8 rats by means of external coincidence detectors. Water extraction fraction in rat brain was 0.67 +/- 0.13 (mean +/- SD) and permeability-surface product was 1.75 ml/g min, where cerebral blood flow and arterial carbon dioxide tension were 1.71 +/- 0.86 ml/g min and 44.8 +/- 14.0 mm Hg, respectively. Water extraction fraction was stable with different measurement times from 20 to 80 seconds.
Animals↗
Blood recirculation and pharmacological responsiveness of the cerebral vasculature following prolonged ischemia of cat brain.
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Animals↗