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Biomedical subjects

T Higuchi

Publications and source records attributed to T Higuchi.

At least 541 records · Page 30Linked to original sources
PubMed1986

Quantitative analysis of ultrasonogram of the prostate.

In 51 cases with prostatic cancer, 88 with prostatic hypertrophy, 109 with prostatitis, and 174 normal subjects, the following five parameters were calculated from prostatic ultrasonograms scanned transrectally; prostatic weight (W), presumed circle area ratio (PCAR), anteroposterior diameter/transverse diameter (ATR), asymmetry index (ASI), and dissimilarity index (DSI). The W and PCAR were higher in cancer and hypertrophy than in prostatitis and normal subjects. The ATR and ASI were higher in cancer. The DSI was lower in hypertrophy. A canonical discriminant analysis using these five parameters disclosed two canonical variates that were useful to separate the disease entities: one separated cancer and hypertrophy from prostatitis and normal subjects, and the other separated cancer from hypertrophy. The coefficients of these variates indicated that cancer was separated from prostatitis and normal subjects by increases in W and ATR and from hypertrophy by the greater effect of increases in ATR (as compared to PCAR) and the small increases in W.

Biometry↗
PubMed1986

Rapidly growing aneurysm.

A rare case of rapidly growing intracranial aneurysm is reported. The enlarged aneurysmal wall was extirpated and studied histologically. The cause of the rapid growth of the aneurysm is discussed.

Humans↗
PubMed1986

Value of high-resolution computed tomography in diagnosis of petrous bone fracture.

High-resolution computed tomography (CT) was performed on 31 patients clinically suspected of having petrous bone fracture. The location of the fracture was demonstrated accurately in 28 patients (90.3%), whereas it could be diagnosed by plain skull film in only 17 patients (54.8%). The anatomic location of fractures demonstrated by high-resolution CT clearly corresponded to the clinical symptoms and signs. We have classified petrous bone fracture into five types according to the anatomic levels demonstrated on CT images. The findings indicate that high-resolution CT is extremely useful for diagnosing petrous bone fracture.

Humans↗
PubMed1986

Radiofrequency hyperthermia with successive monitoring of its effects on tumors using NMR spectroscopy.

Radiofrequency (rf) hyperthermia was generated on rat glioma inoculated s.c. in CD Fisher rats by applying the rf pulse using the surface coil in the NMR spectrometer, and the effect was monitored successively in the same spectrometer by measuring 31P NMR spectra and 1H NMR images. In the 31P NMR spectrum at the preirradiation stage, nucleoside triphosphate peaks and a phosphomonoester peak were high and a Pi peak was low. After a rf pulse at a power of 5 W was applied continuously for 60 min, the nucleoside triphosphate peaks decreased and the Pi peak increased immediately, resulting finally in a dominant Pi peak pattern within 30 min in all 10 cases examined. These spectral changes occurred much earlier than the histological changes and lasted for at least 7 days. By the 1H NMR imaging, the necrotic region was detected as a high-intensity lesion in spin echo and inversion recovery images 2 days after the irradiation. There were no changes either in the spectrum or in 1H NMR images in any of 8 cases after irradiation with a rf pulse of less than 3 W. Thus, we could generate rf hyperthermia with the NMR spectrometer and the effects were monitored sensitively with the same spectrometer. It can be concluded that the NMR device can be used not only for diagnosis but also as a therapeutic tool.

Animals↗
PubMed1986

Intestinal absorption of sodium cefoxitin in rats: effect of formulation.

The absorption of cefoxitin from rat intestine, rectum and small intestine was greater when the powdered form was administered than when an aqueous solution was given. Cefoxitin absorption from the small intestine was significantly increased after its administration in suppository form prepared with a triglyceride base, although rectal absorption from the suppository did not differ from that of the drug in powdered form. The increase in absorption by the small intestine from the suppository form may be due to fatty acids produced from triglyceride by lipase.

Animals↗
PubMed1986

Effect of particle size and food on gastric residence time of non-disintegrating solids in beagle dogs.

The gastric residence times of various sizes of radio-opaque particles and tablets were measured in beagle dogs by X-ray, both in the fasted state and after a single meal. During the course of the studies, changes in intragastric pH were also monitored with a radiotelemetric pH sensor, the Heidelberg capsule. The gastric residence time increased with increasing particle size and with particles greater than or equal to 5 mm in diameter approached a plateau value both in the fasted state and after feeding. This value was about 7.5 h after feeding and about 1.5 h in the fasted state, and probably corresponded to the occurrence of the interdigestive migratory myoelectric complex (IMMC wave). The pH in the stomach was variable in the fasted state, but an abrupt pH increase (up to pH 6-7) was observed during the emptying of larger tablets. In some instances this high pH in the stomach was maintained until the next IMMC wave occurred. The gastric emptying of larger tablets administered with food was also associated with an abrupt pH increase.

Animals↗
PubMed1986

Evaluation of the effects of photoradiation therapy on brain tumors with in vivo P-31 MR spectroscopy.

In vivo phosphorus-31 magnetic resonance (MR) spectra were obtained by a surface coil method from rat glioma tissue inoculated subcutaneously in CD Fisher rats, and the effects of photoradiation therapy on tumors were evaluated by sequentially observing spectral changes. In the control group, the nucleoside triphosphate (NTP) and phosphomonoester peaks were large, the phosphocreatine peak was small, and the inorganic phosphate (Pi) peak was intermediate. In all eight cases in the group in which a dose of 10 mg/kg of hematoporphyrin derivatives (HpD) was given before photoirradiation, NTP peaks decreased, and the Pi peak increased remarkably within 1 hour after the 60-minute white-light irradiation. Spectral changes were observed before histologic changes were apparent. Histologic examinations 3 days after irradiation showed extensive necrosis in the tumor tissue. With preinjection of 5 mg/kg HpD, three of the eight cases showed spectrum changes after the irradiation. No spectrum changes were observed in the group with preinjection of 2.5 mg/kg. In vivo P-31 MR spectra measurements are useful not only to investigate the energy metabolism of tumor tissue in vivo but also to evaluate the effects of photoradiation therapy on tumors.

Animals↗
PubMed1986

Effect of clonidine on insulin secretion: a case report.

We have recently seen a case of non-insulin-dependent diabetes mellitus with hypertension in which chronic treatment with oral clonidine gave rise to elevation of blood glucose and decreased insulin secretion. When the response of insulin secretion to glucose administration during clonidine therapy was compared with that after 12 days of wash-out for clonidine in this patient (who was then receiving phentolamine mesylate), there was a marked suppression of insulin secretion to stimulation by intravenous glucose during oral clonidine therapy. This result indicates that the decreased insulin secretion associated with oral clonidine therapy is very unlikely to be due to any direct action of clonidine on beta cells of the pancreatic islets and may be due to suppression of catecholamine release via central alpha-adrenergic receptor stimulation.

Blood Glucose↗
PubMed1986

Biochemical and pharmacological analysis of 2-[(2-dimethylaminobenzyl)sulfinyl] benzimidazole (NC-1300), a new proton pump inhibitor.

Biochemical and pharmacological properties of a newly synthesized compound, 2-[(2-dimethylaminobenzyl)sulfinyl] benzimidazole (NC-1300), were studied. NC-1300, at pH 6.0, potently inhibited the activity of H+ K+ ATPase in the rabbit gastric mucosa, thereby classifying it as a proton pump inhibitor. The inhibitory efficacy of NC-1300 on the pump was much the same as that seen with omeprazole. NC-1300 had no effect on acetylcholine-stimulated ileum contraction in guinea pigs at 10(-5) M, but it non-competitively inhibited the contraction at 10(-4) M. NC-1300 had no effect on histamine-stimulated atrial beating frequency in guinea pigs at 10(-4) or 10(-5) M. NC-1300, given either intraduodenally or orally, had a potent and long-lasting (more than 24 hr) inhibitory effect on gastric secretion in pylorus-ligated rats. Pretreatment with NC-1300 dose-dependently protected the gastric mucosa from damage induced by pylorus ligation, water-immersion stress, aspirin, and indomethacin, and the duodenal mucosa from damage induced by mepirizole in rats. We conclude that the antisecretory activity of NC-1300 appears to be mainly related to an inhibition of H+ K+ ATPase, while its antigastric and antiduodenal lesion activities are primarily related to an antisecretory effect.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1986

Oxytocin release during parturition in the pelvic-neurectomized rat.

Blood levels of oxytocin during parturition in pelvic-neurectomized rats were determined by radioimmunoassay. Four out of 29 pelvic-neurectomized rats completed parturition within 23 days of pregnancy. These rats exhibited an increase in blood levels of oxytocin during parturition similar to those of shamoperated control rats, but delivery took longer and there was a higher percentage of still-births. The rise in blood levels of oxytocin was smaller in the 16 rats in which the first fetus was expelled but where delivery did not end within day 23 of gestation than that in sham-operated controls. Levels did not increase in the other nine rats which failed to deliver the first fetus within 23 days of pregnancy. They did, however, show signs indicating delivery, such as stretch movements, vaginal bleeding and/or excretion of mucus within 23 days of gestation. Oxytocin infusion (2 mu./min) for 2-4 h increased uterine contractions in the pelvic-neurectomized rats but failed to reduce the percentage of still-births or the duration of delivery. Immunoneutralization of circulating oxytocin by anti-oxytocin serum in intact pregnant rats resulted in a significant but much smaller prolongation of the duration of delivery compared with that observed in pelvic-neurectomized rats. The rise in blood levels of oxytocin during pregnancy may be induced, at least in part, by the Ferguson reflex via the pelvic nerve and may thus facilitate the process of delivery. A shortage of oxytocin secretion may not, however, be the main cause of the dystocia in pelvic-neurectomized rats.

Animals↗
PubMed1986

Influence of oestrogen and noradrenergic afferent neurones on the response of LH and oxytocin to immobilization stress.

The influence of oestrogen on LH and oxytocin responses to immobilization stress, and the involvement of noradrenergic afferent neurones in these responses, was examined in ovariectomized rats with or without pretreatment with oestrogen or after noradrenergic transmitter blockade. Immobilization of the rats on a board in a supine position for 1 h brought about a rapid decrease in LH levels and an increase in oxytocin levels in the blood of ovariectomized rats. Oestradiol benzoate (20 micrograms) injected s.c. the day before immobilization, decreased basal LH levels but had no effect on basal oxytocin levels. Immobilization stress applied to oestrogen-treated rats induced a small but significant increase in LH concentrations and a rise in oxytocin concentrations similar to that in rats without oestrogen pretreatment. A dopamine-beta-hydroxylase inhibitor or phenoxybenzamine (alpha-adrenoceptor blocker) injected into ovariectomized rats reduced basal LH levels and increased basal oxytocin levels in the blood. Immobilization stress induced an increase in LH levels in rats treated with dopamine-beta-hydroxylase inhibitor, but had no effect in rats treated with phenoxybenzamine. Stress induced a larger increase in blood oxytocin levels in rats treated with either drug compared with that in control rats injected with vehicle. On the other hand, propranolol (beta-adrenoceptor blocker) had no effect on basal or stress-induced changes in LH or oxytocin levels in the blood. These results indicate that the LH response to stress, which might be mediated through alpha-adrenergic neurones, depends on the circulating oestrogen or LH levels before the stress. In contrast, the oxytocin response to stress may not be mediated by noradrenergic neurones and may not be influenced by oestrogen.

Animals↗
PubMed1986

Detailed analysis of blood oxytocin levels during suckling and parturition in the rat.

A detailed secretory profile of oxytocin during suckling and parturition was determined in unanaesthetized freely moving rats. Ten pups were reunited with their mothers after 12-15 h of separation. Unless the milk-ejection reflex occurred, there was no difference in serum oxytocin levels before separation and during the suckling of either four or five, or nine or ten pups. Serum oxytocin levels increased abruptly by 50.1 +/- 4.2 (S.E.M.) pmol/l (n = 9) at milk ejection, and declined rapidly with a half-life of about 1.5 min. The peak concentration of blood oxytocin at each milk ejection was independent of the previous suckling period; values from the first three milk-ejection reflexes following the introduction of the pups and those observed 3-5 h after introduction were similar. The process of parturition was monitored by recording intra-uterine pressure with a balloon implanted in the uterus. On day 22 or 23 of pregnancy, continuous and rhythmical contractions of the uterus occurred (onset of parturition), but serum levels of oxytocin (21.1 +/- 1.9 pmol/l; n = 13) did not alter until the expulsive phase. During the expulsive phase, fetuses were delivered after fetus-expulsion reflexes which were recorded as sudden large increases in intra-uterine pressure. Basal levels of oxytocin in the blood increased during this phase (32.5 +/- 4.4 pmol/l; n = 13) and, in addition, rose by about 15 pmol/l and declined slowly after fetus-expulsion reflexes. The increase, however, was quite different from that seen at milk-ejection reflexes.

Animals↗
PubMed1986

[Hematomas of the lenticular nucleus and pons in a hypertensive patient].

Secondary pontine hemorrhages are not rare in intracranial hypertension caused by a supratentorial mass lesion. Cerebral herniation and caudal dislocation of the brainstem account for the secondary pontine hemorrhages. In the present case, two unrelated hemorrhages were demonstrated by an early CT. Neurological findings and CT thus suggest that this is a rare case in which supratentorial and infratentorial hypertensive intracerebral hemorrhages occurred simultaneously.

Adult↗