Biomedical subjects

Y Maki

Publications and source records attributed to Y Maki.

At least 91 records · Page 5Linked to original sources

PubMed1990

Effect of pH on acid production from sorbitol in washed cell suspensions of oral bacteria.

The acid production from sorbitol and glucose was studied under anaerobic conditions in resting cell suspensions of bacteria from the predominant sorbitol-fermenting human dental plaque flora, belonging to the genera Streptococcus, Lactobacillus and Actinomyces. The acid production activity of the bacterial cells was followed by titration with alkali, at environmental pH 7.0, 6.0 and 5.0 after addition of carbohydrate solution. The metabolic end products formed in the suspensions were analyzed thereafter by isotachophoretic and enzymatic methods. The results showed that sorbitol was fermented at a slower rate than glucose. Lowering the environmental pH decreased the acid production activity from the two carbohydrates. Compared with glucose, the catabolism of sorbitol was affected to greater extent by the pH conditions. The total amount of acids formed from sorbitol was considerably less than from glucose. Lactic acid, which was the major end product in glucose-challenged suspensions, was produced only in low concentrations from sorbitol by all strains tested. The ratio strong (formic + lactic)/weak acids was moreover lower for sorbitol than for glucose. The present results further illustrate some of the mechanisms behind the low cariogenic potential of this sugar substitute.

Acetates↗

PubMed1990

Synthesis and anti-human immunodeficiency virus (HIV-1) activity of 3'-deoxy-3'-(triazol-1-yl)thymidines and 2',3'-dideoxy-3'-(triazol-1-yl)uridines and inhibition of reverse transcriptase by their 5'-triphosphates.

3'-Deoxy-3'-(1,2,3-triazol-1-yl)thymidines (5a, 6a, 8a, 11a, and 12a) and 2',3'-dideoxy-3'-(1,2,3-triazol-1-yl)uridines (5b, 6b, 8b, 11b, and 12b) were synthesized as cyclic analogues of 3'-azido-3'-deoxythymidine (AZT) and 3'-azido-2',3'-dideoxyuridine (CS-87) by the cyclization of 5'-trityl derivatives (1a, b) of AZT and CS-87 using alpha-ketophosphorus ylides and with acetylenic compounds followed by deprotection of the 5'-trityl group. It was hypothesized that the triazole nitrogen atoms could mimic and distorted azido group. However, no significant activity against human immunodeficiency virus type 1 (HIV-1) was observed with any of these compounds. 5'-Triphosphates (17a and 18a, b), prepared from 5a and 6a, b, were inactive against HIV-1 and Rauscher murine leukemia virus (RLV) reverse transcriptases.

Acquired Immunodeficiency Syndrome↗

PubMed1990

SDS-polyacrylamide gel electrophoretic patterns of human parotid saliva treated with polyvinylpyrrolidone-iodine in vitro.

In the intraoral application of polyvinylpyrrolidone-iodine (PVP-I) as an antimicrobial agent, a color fading phenomenon is observed that might be caused by the binding of iodine with saliva. We have investigated the binding of iodine with saliva as iodine binding factor (IBF). The presence and characteristics of the IBF were investigated in parotid saliva stimulated by sour lemon drops, unstimulated parotid saliva, and whole saliva. A high level of the binding ability with iodine was observed in stimulated parotid saliva with the treatment of PVP-I compared with the unstimulated, but there were no significant differences in the amounts of total proteins between the stimulated and unstimulated. Electrophoretic patterns of saliva treated with PVP-I and untreated were examined to detect the IBF. The protein band of SDS-polyacrylamide gel electrophoresis near M.W. 60,000 of stimulated parotid saliva disappeared after treatment of PVP-I. This evidence indicates that the color fading phenomenon of PVP-I is associated with a polypeptide level in saliva.

Adult↗

PubMed1990

Possible mechanism for the inhibition of acid formation by the proton pump inhibitor AG-1749 in isolated canine parietal cells.

We have reported previously that 2-[[[3-methyl-4-(2,2,2-trifluorethoxy)-2-pyridyl]methyl] sulfinil]- 1H-benzimidazole (AG-1749) inhibits (H+ + K+)-adenosine triphosphatase after being transformed into its cyclic sulfenamide form (AG-2000) or disulfide form (AG-1812) under acidic conditions. In this study, mechanisms related to the inhibition of acid formation by AG-1749 were investigated in isolated canine parietal cells. AG-1749 suppressed the acid formation stimulated by histamine, carbachol or dibutyryl cyclic AMP with IC50 values of approximately 0.09 microM: AG-1749 being twice as potent as omeprazole. The inhibitory effect of AG-1749 was antagonized by dithiothreitol (1 mM). 2-Cyclo-hexen-1-one (3 mM) decreased cytosolic glutathione to less than 10% of control value, and caused a 3-fold increase in the inhibitory effect of AG-1749. Glutathione, however, when added exogenously, did not affect the action of AG-1749. The inhibition was reversed by removing AG-1749 from the medium or by adding dithiothreitol (1 mM). The reversal of inhibition by these two procedures was hardly affected by puromycin (100 microM) or cycloheximide (300 microM) but significantly prevented by 2-cyclo-hexen-1-one (1 mM). Exogenously added AG-2000 (10 microM) or AG-1812 (5 microM), active forms of AG-1749, did not inhibit acid formation.(ABSTRACT TRUNCATED AT 250 WORDS)

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed1990

[Instrumentation surgery for tumor of the spine].

Spinal instrumentation surgery has come into wide use recently, especially for tumor of the spine. It is very effective for fixing the spine for relieving the patient from pain. But the decision about the indication of instrumentation surgery for tumor of the spine must be made carefully. In cases of double malignant tumors including spinal tumor, it is hard to decide how to treat tumor of the spine. We report a case of 78-year-old male with multiple myeloma of the cervical spine and cancer of the prostate. The patient had been in good health until one year previously, when he started to complain of nuchal pain. He became bedridden with loss of voluntary control of the right upper extremity for the last two months. Then he was admitted to our hospital and radiological examination was carried out. It revealed tumor of the cervical spine and it seemed to be bone metastasis. Further examination revealed that the patient was suffering from multiple myeloma and cancer of the prostate. The tumor of the spine was diagnosed as either multiple myeloma or metastasis of cancer of the prostate. Spinal instrumentation surgery using Luque-rod was carried out as one of the comprehensive treatment plans for double malignant tumors. The instrumentation surgery was effective for fixing the spine and improving the patient's quality of life. In operative procedures, intraoperative spinal cord monitoring was carried out. Intraoperative spinal cord monitoring was indispensable for preventing spinal cord injury. The tumor of the spine was diagnosed as multiple myeloma by pathological examination.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1990

[Non-ketotic hyperosmolar diabetic coma in neurosurgical cases; review of 7 cases].

Neurosurgical patients with non-ketotic hyperosmolar diabetic coma (NHC) in our institution were analysed retrospectively. Seven cases were diagnosed as NHC being 0.47% of the number of inpatients in the last 5 years. The age ranged from 60 to 72 years old (mean 65) and there were 6 males and 1 female. Only 2 patients (29%) had a clear past history of diabetes mellitus. Prior to the NHC, systemic infection was present in 2 cases. Intravenous hyperalimentation (IVH) was performed in 5 cases, glycerol osmotherapy in 3 cases, diphenylhydantion therapy in 3 cases and tube feeding in 2 cases. The overall mortality rate in our series was 71% (5 cases), of which 2 cases died within 2 days due to cardiopulmonary failure, and 3 cases in the chronic stage died due to disseminated intravascular coagulopathy (DIC), or due to renal failure. The prognosis of NHC in neurosurgical patients is generally bad because of the presence of consciousness disturbance prior to the onset of NHC, which may mask the symptoms occurring from the NHC. Other predisposing factors could be systemic infection, IVH or tube feeding, and osmotic agents which are frequently used in neurosurgical patients. There was a tendency for NHC to occur predominantly in the chronic stage after the blood sugar had returned to normal range from the hyperglycemic state in the acute stage.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1989

A technique for replantation of the finger tip.

The finger-tip replantation technique reported here has evolved over 15 years. Indications for surgery include both strong patient desire and specialized use of the finger tip. Palmar flaps are elevated as full-thickness skin grafts to avoid injury to palmar veins. Arteries and palmar digital veins are repaired using an open-vessel technique. Postoperative care varies from immediate discharge with follow-up to inpatient care using surgical leeches or continuous bleeding as a method of drainage should venous congestion develop. The survival rate of 26 finger tips replanted using this technique between 1981 and 1987 was 69%. Two-point discrimination returned in 75% of patients, and 25% had two-point discrimination of less than 5 mm. The distal interphalangeal joint retained an average range of motion of 56 degrees. Appearance was excellent, and patient satisfaction was high.

Fingers↗

PubMed1989

Inhibitory effects of methyl 7-butyl-4,5,6,7-tetrahydro-3-methylamino-4,6-dioxo-5-propyl- 2H-pyrazolo[3,4-d]pyrimidine-2-carboxylate (AA-2379) on lysosomal enzyme and arachidonic acid release from rat polymorphonuclear leukocytes and its mode of action.

AA-2379 (methyl 7-butyl-4,5,6,7-tetrahydro-3-methylamino-4,6-dioxo-5-propyl- 2H-pyrazolo [3,4-d]pyrimidine-2-carboxylate) has antiinflammatory, analgesic, and antipyretic activities, and inhibits the type III allergic (Arthus) reaction. In the studies reported here, we investigated the effect of AA-2379 on rat polymorphonuclear leukocyte (PMN) functions to clarify the mechanism of the antiinflammatory and antiallergic actions of AA-2379. AA-2379 at 10(-4) M inhibited lysozomal enzyme release. AA-2379 inhibits formyl methionyl-leucyl-phenylalanine (fMLP)- and C5a-induced arachidonic acid release; their 50% inhibitory concentrations were 2.8 x 10(-5) and 3.8 x 10(-5) M, respectively. Because dibutyryl cAMP, a cAMP analogue, and 3-isobutyl-1-methylxanthine, a cAMP phosphodiesterase inhibitor, inhibited fMLP-induced arachidonic acid release, and AA-2379 inhibited cAMP phosphodiesterase and increased cAMP content in PMNs, it is likely that AA-2379 inhibited arachidonic acid release by increasing cAMP content in rat PMNs. Furthermore, from the studies of fMLP-induced arachidonic acid release in Ca free medium it is suggested that AA-2379 inhibits the process which depends on Ca concentration in the medium. These results suggest that the inhibitory effect of AA-2379 on inflammation and allergic reactions such as the Arthus reaction is partly exerted by inhibiting PMN functions such as arachidonic acid and lysozomal enzyme release.

3',5'-Cyclic-AMP Phosphodiesterases↗

PubMed1989

Effects of low-concentration polymyxin B on insulin secretion induced by 12-O-tetradecanoyl-phorbol-13-acetate (TPA), glucose, or tolbutamide from the isolated perfused rat pancreas.

To evaluate the role of protein kinase C on insulin secretion, we investigated the effects of low-concentration polymyxin B (100 mumol/L) on insulin secretion from the isolated perfused rat pancreas induced by 12-O-tetradecanoyl-phorbol-13-acetate (TPA, 10 nmol/L), a protein kinase C activator, glucose (10 mmol/L), or tolbutamide (738 mumol/L). Polymyxin B, a potent and relatively selective protein kinase C inhibitor at this low concentration, did significantly inhibit the gradual rise of insulin secretion induced by TPA (P less than .05). As for glucose or tolbutamide stimulation, polymyxin B significantly inhibited not only the second phase but also the first phase of insulin secretion (P less than .05) without changing the secretion patterns. Although the possibility of nonspecific effects of polymyxin B other than protein kinase C inhibition could not be excluded, the data suggest that protein kinase C might be involved in insulin secretion as a potentiating modulator.

Animals↗

PubMed1989

A small temporal lobe glioma detected only by magnetic resonance imaging.

The authors were able to demonstrate a very small glioma (1.0 x 0.8 cm in size) of the temporal lobe using MRI. They discuss the relative merits of CT and MRI in the diagnosis of gliomas in terms of their size. CT fails to detect tumours less than 2.0 x 1.5 cm in size which are not calcified. So far, MRI has revealed a tumour as small as 1.0 x 0.8 cm. Therefore, MRI is superior to CT for detecting small gliomas.

Adult↗

PubMed1989

A case of unilateral adrenal medullary hyperplasia.

We report a case of unilateral hyperplasia of the adrenal medulla. The patient showed clinical features suggestive of pheochromocytoma. Removal of the hyperplastic adrenal gland resulted in complete disappearance of all prior symptoms, decrease of the plasma and urinary catecolamine levels and no high uptake in [133I] metaiodobenzylguanidine scintigraphy. A histological study revealed diffuse hyperplasia of the adrenal medulla. Up to now, there are relatively few reports of adrenal medullary hyperplasia in English literatures.

Adrenal Gland Neoplasms↗

PubMed1989

Congenital arteriovenous malformation of the scalp--case report.

A case of congenital arteriovenous malformation (AVM) of the scalp containing a complex vascular network is described. The AVM was totally removed, together with its feeding artery and draining veins. Congenital AVM of the scalp is rare; only 21 other cases have been reported since 1973. All involved complex vascular networks, and about one half of the patients had red or purple birthmarks. These clinical features clearly differ from those of traumatic arteriovenous fistulae of the scalp. Although many treatment approaches have been tried, total excision appears to be the most appropriate.

Adult↗

PubMed1989

Morphometrical and biochemical differences of endocrine pancreata between spontaneously hypertensive and normotensive rats with or without neonatal streptozotocin-induced diabetes.

We studied the morphometrical and biochemical changes of endocrine pancreata in spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto rats (WKY) with or without noninsulin-dependent diabetes mellitus induced by neonatal streptozotocin (STZ) treatment at 4 months of age. Female (2-day-old) neonates were intraperitoneally injected with 62.5 or 75.0 mg/kg of STZ for SHR, 87.5 or 100.0 mg/kg of STZ for WKY, and vehicle for control. In STZ-treated groups, overt hyperglycemia developed in SHR with significantly decreased serum immunoreactive insulin (IRI), whereas in WKY, hyperglycemia was very mild and serum IRI was not lowered. The number and mean size of pancreatic islets did not differ between SHR and WKY, although mean islet size was reduced by half in both compared with that in the corresponding control, respectively. Percentage distribution of insulin-positive B cells in the islet was significantly reduced more in SHR than in WKY (34% of control versus 64% of control, p less than 0.05). Furthermore, pancreatic IRI content was far more reduced in SHR than in WKY (3% of control versus 43% of control, p less than 0.001). In vehicle-treated groups, the glycemic levels and the morphometrical islets did not differ between SHR and WKY. However, serum IRI was significantly lower but pancreatic IRI content was higher in SHR than in WKY. The mechanisms of strain differences between SHR and WKY seen in the present study were discussed.

Animals↗

PubMed1989

Possible mechanism for the inhibition of gastric (H+ + K+)-adenosine triphosphatase by the proton pump inhibitor AG-1749.

Mechanisms related to the inhibition of (H+ + K+)-adenosine triphosphatase (ATPase) by 2-[[[3-methyl-4-(2,2,2-trifluoroethoxy)-2-pyridyl]methyl] sulfinyl]-1H-benzimidazole (AG-1749) were studied using canine gastric microsomes. AG-1749 (1-100 microM) inhibited the K+-stimulated ATP hydrolysis and vesicular accumulation of H+. AG-1749 bound to the microsomes concentration-dependently and decreased the number of free SH groups; the binding correlating with the enzyme inhibition. Both the binding and inhibition were antagonized by dithiothreitol. N-ethylmaleimide inhibited the (H+ + K+)-ATPase and decreased the binding of [14C]AG-1749 to the microsomes. The inhibitory effect of AG-1749 gradually increased with incubation time, and was enhanced by lowering the pH. AG-2000 and AG-1812, acid-induced rearrangement products of AG-1749, inhibited (H+ + K+)-ATPase potently, rapidly and independently of pH; the inhibition was antagonized by dithiothreitol. We propose that AG-1749 is transformed into its active forms within the acidic compartment of the parietal cells and that the active compounds inhibit (H+ + K+)-ATPase activity by reacting with the SH groups of the enzyme.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed1989

Antisecretory and antiulcer activities of a novel proton pump inhibitor AG-1749 in dogs and rats.

The antisecretory and antiulcer activities of 2[[[3-methyl-4-(2,2,2-trifluoroethoxy)-2-pyridyl]methyl] sulfinyl]-1H-benzimidazole (AG-1749) were investigated in dogs and rats. AG-1749 inhibited both the (H+ + K+)-adenosine triphosphatase activity in canine gastric microsomes and dibutyryl cyclic AMP-stimulated acid formation in isolated canine parietal cells and suppressed the acid secretion stimulated by histamine, pentagastrin, bethanechol or a peptone meal in Heidenhain pouch dogs; the ID50 values were between 0.2 and 0.7 mg/kg p.o. AG-1749 inhibited both the histamine-stimulated and the basal acid secretion in pylorusligated rats and prevented water immersion stress or aspirin-induced gastric lesions and mepirizole or cysteamine-induced duodenal ulcers in rats; the ID50 values were between 0.3 to 3.6 mg/kg p.o. or i.d. Furthermore, AG-1749 prevented gastric lesions induced by absolute ethanol or acidified aspirin, and accelerated the healing of acetic acid-induced gastric or duodenal ulcers in rats. The inhibitory potency of AG-1749 in dogs was much the same as that of omeprazole and about half that of ranitidine. However, it was about 2 to 10 times more potent than omeprazole and 4 to 34 times more potent than ranitidine in rats. These results suggest that AG-1749 exerts prominent antiulcer activities mainly by suppressing acid secretion via an inhibition of a proton pump in gastric parietal cells and partly by protecting the gastrointestinal mucosa against various ulcerative stimuli.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed1989

8-Methyladenosine-substituted analogs of 2-5A: synthesis and properties.

Four 8-methyladenosine-substituted analogs of 2-5A were obtained by a synthesis which involved a modification of the lead ion-catalyzed ligation reaction. Substituent of an 8-methyladenosine residue at the third position (2'-terminal) of the oligonucleotides increased the stability to snake venom phosphodiesterase digestion.

Adenine Nucleotides↗

PubMed1989

[Dental health status of junior high school students in the suburbs of Chiba city].

The Population of 12-15 years is a key age group for oral health because the permanent dentition and periodontal tissues are almost complete at this stage. The purpose of this study was to evaluate oral health status and to develop an effective school dental health program for junior high schools students. The survey was performed on 527 persons aged 12-13 at 2 junior high schools in the suburbs of Chiba city. Periodontal disease was evaluated on the basis of the CPITN, and analyzed for severity and region of periodontal disease. Gingivitis was examined with PMA index, using color photo slides taken of anterior dentition at the time of inspection. At the same time, caries experience and oral hygiene index were also estimated. The results were as follows: (1) The mean DMFT was 3.89. Caries prevalence in females was higher than males. Ratio of treated teeth rate was 77.03%; that of untreated teeth rate was 22.65%. Females revealed less treatment for caries than males. Oral hygiene index showed significant difference between males and females. Labial and buccal parts of the maxillary and molar region on the mandibular showed remarkable plaque deposition. Calculus accumulation in this population was greatest on the lower incisor. (2) The mean PMA index was 7.36. Gingivitis was highly prevalent in both sexes, although it was more severe in males. There was correlations between PMA index and OHI. (3) From the results of CPITN, 10.6% of the subjects showed no signs of periodontal disease (Code 0), and 5.7% exhibited gingival bleeding (Code 1).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1989

[Distribution of dental plaque and time analysis of toothbrushing without instruction in school children and students].

The purpose of this study is to evaluate oral hygiene before and after individual method toothbrushing without instruction and to analyze toothbrushing times for school children from 6 to 13 years of age. Subjects were 150 pupils from primary to junior high school affiliated with the faculty of education of an university located in Setagaya, Tokyo: 38 first-grade pupils aged 6, 36 fourth-grade pupils aged 9, 37 sixth-grade pupils aged 11, and 39 second-year junior high school pupils aged 13. Assessments of dental plaque were made by two dentists using the PHP plaque score (Podshadely and Haley, 1968) for primary school pupils and OHI-S (only DI-S; Greene and Vermillion, 1964) for junior high school pupils. Plaque distribution disclosed by an Erythrosine solution was examined before and after toothbrushing, and the performance of toothbrushing by subjects was recorded on video-tape through a one-way mirror so that the children were unaware. Toothbrushing time was measured by 2 or 3 examiners using a time counter of video-monitor. Average scores for dental plaque before and after toothbrushing were almost the same for first and fourth-grade primary school pupils; but scores decreased with a statistically significant difference (p less than 0.01) for sixth-grade pupils. Distribution patterns of plaque scores for fourth-grade pupils showed characteristically narrow ranges (2-5 before brushing and 1-4 after brushing). The majority of subjects (69.4%) had scores of 2-3 after brushing, Whereas only 8.3% showed a range of 2-3 before brushing.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗