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Biomedical subjects

K Uchide

Publications and source records attributed to K Uchide.

35 records · Page 2Linked to original sources

Effects of testosterone on the development of endometrial tumors in female rats.

Long-term treatment of mature virgin female rats with a high dose of testosterone (24 weeks at a total dose of 300 mg) was associated with the development of endometrial adenomatous hyperplasia and resulted in a high incidence of adenocarcinoma when administered in combination with 7,12-dimethyl-benz[a]anthracene (DMBA; 2 mg in 0.1 ml sesame oil) introduced into the uterine cavity. Adenomatous hyperplasia occurred in all testosterone-treated rats, both with and without ovaries. Testosterone may promote the induction of endometrial tumors by DMBA.

9,10-Dimethyl-1,2-benzanthracene↗

A follicular cyst during tamoxifen therapy in a premenopausal breast cancer woman.

A large ovarian follicular cyst developed on day 43 of low-dose tamoxifen adjuvant therapy for a premenopausal breast cancer (total drug intake: 860 mg). The serum estradiol level increased to almost ten times the pretreatment level. However, the FSH and LH decreased slightly, and the serum progesterone level remained almost unchanged. It is hypothesized that tamoxifen acted directly on the ovaries to provoke excessive proliferation of the granulosa cells in a follicular cyst, causing it to grow very large, and resulting in elevated E2 levels.

Adult↗

Partial hydatidiform mole in the fallopian tube.

An extremely rare case of partial hydatidiform mole located in the right Fallopian tube was diagnosed by ultrasonography and computed tomography. The lesion was excised, and the human chorionic gonadotropin (HCG) level in early morning urine fell below 1,000 IU/ml on postoperative day 11, and the serum HCG-beta level normalized on postoperative day 46.

Adult↗

Deoxyribonuclease I (DNase I) typing from semen stains: low enzyme activity in vaginal fluids does not interfere with seminal DNase I typing from mixture stains.

We describe the use of deoxyribonuclease I (DNase I) polymorphism for individualization of semen in body fluid stain mixtures, as a means of providing new and more useful information to practicing forensic biologists as a genetic marker. We have already reported that human DNase I isozyme patterns from different subjects are classifiable into ten groups. Isoelectric focusing of DNase I isozymes on polyacrylamide gel (IEF-PAGE, pH 3.5 to 5) was accomplished using a 0.5 mm thick gel. Pretreatment of semen samples with neuraminidase enhanced the isozyme band resolution and sensitivity. Activity detection using the dried agarose film overlay (DAFO) procedure was reliable, sensitive and simple, with high resolution, and the phenotypes of DNase I were determined in semen stains of about 0.3 microL stored at room temperature for up to a year in most of the samples tested. The DNase I types in semen stains were correlated with the types found in the corresponding blood and urine samples, although most of the vaginal fluid samples had no typable DNase I activity. This is considerably advantageous for seminal individualization from body fluid mixture stains in criminal cases. An evaluation of DNase I typing by IEF-PAGE and DAFO was also performed on casework samples submitted to our laboratory, and the results showed that DNase I was expected to be one of the most useful individualization marker of semen in practical application.

Body Fluids↗

Effect of testosterone on the development of bladder tumors and calculi in female rats.

In order to study the effect of testosterone on bladder calculi and tumor formation in female rats, Wistar rats were administered testosterone for 12, 18 or 24 weeks. Testosterone was found to increase the incidence of both bladder calculi and tumors in intact, but not in oophorectomized rats. It is suggested that testosterone in combination with estrogen may contribute to hyperplasia formation, in turn leading to an increased incidence of bladder calculi and tumors.

Animals↗

A lactating adenoma of the breast.

A lactating adenoma of the breast was first examined at the 24th week of gestation, and had doubled in size by the 37th week. After delivery, administration of bromocriptine (5 mg/day) reduced its size, and it was surgically removed on the 10th day. Histologically, the glandular epithelial cells of the adenoma showed the physiological changes normally seen during lactation, and retained much of their lactating activity (especially protein secretion). The myoepithelial cells contained an increased number of lysosomes and also some autophagosomes, implying that the tumor had partly undergone involution similarly to the normal breast tissue.

Adenoma↗

Uterine leiomyoma associated with ascites and hydrothorax.

Uterine leiomyoma associated with ascites and hydrothorax was apparently cured by total hysterectomy. This is believed to be the 15th recorded case of this type of Pseudo-Meigs' syndrome and the first in a patient with severe curvature of the spine and dorsolumbar scoliosis. The association with ascites and hydrothorax was investigated using 99mTc-labeled macroaggregated albumin.

Ascites↗

Cerebral arteriovenous malformations in a pregnancy with twins: case report.

The natural course of cerebral arteriovenous malformations during pregnancy is not well known. An inoperable cerebral arteriovenous malformation was diagnosed by angiography, computed tomography, and magnetic resonance imaging before pregnancy and followed by magnetic resonance imaging during pregnancy. No significant changes were detected in the size of the cerebral arteriovenous malformation during pregnancy, and healthy twins were born by cesarean section.

Cerebral Angiography↗

Vaginal distension induces milk ejection-related burst of oxytocin neurones interacting with suckling stimuli in lactating rats.

Milk ejection-related bursts of action potentials recurred at fairly regular intervals during suckling in oxytocin cells of anesthetized lactating rats. Additional milk ejection-related bursts were frequently induced in response to vaginal distension. The latency for the induced response was 2.9 +/- 0.2 s and the size of the induced bursts was similar to that of spontaneous ones. When animals were not suckled, the burst was in no case induced by the stimulus. The findings indicate that the two afferent stimuli arising from the mammary gland and vagina can interact with each other in generating milk ejection-related bursts of oxytocin cells.

Action Potentials↗

Facilitation of milk ejection-related activation of oxytocin-secreting neurones by osmotic stimulation in the rat.

Extracellular recordings were made from antidromically identified neurosecretory cells in the paraventricular nucleus of the hypothalamus in urethane-anesthetized lactating rats. Sixty-six percent of the rats tested (n = 80) showed reflex milk ejections during suckling. Oxytocin neurones could be distinguished from other neurosecretory neurones by a characteristic high-frequency burst of spikes displayed before a reflex milk ejection. Twenty-three of the oxytocin neurones recorded from twenty-three individual animals were tested for the effect of intraperitoneal injection of 1.5 M NaCl (1 ml), which raised the plasma osmotic pressure from 299.3 +/- 2.4 (SE) mosmole/kg to 313.0 +/- 2.4 mosmole/kg. The injection significantly increased not only the firing rate of the oxytocin neurones (from 1.7 +/- 0.3 spikes/s to 4.9 +/- 0.6 spikes/s) but also the number of spikes per burst (from 53.6 +/- 7.4 to 75.5 +/- 7.5) and burst duration (from 3.38 +/- 0.22 s to 3.80 +/- 0.18 s). The amplitude of reflex milk ejection was also increased to 1.9 times. However, the injection did not change the interval between bursts. On the other hand, intraperitoneal injection of 0.15 M NaCl affected neither these parameters of oxytocin neurones nor the amplitude of milk ejection. Some of the antidromically identified neurones recorded in the rats which showed no detectable reflex milk ejection during suckling displayed intermittent bursts of action potentials. Ten of these neurones in ten individual rats were tested for the effect of 1.5 M NaCl. The number of spikes per burst was significantly increased and reflex milk ejection was induced by the injection in eight of these rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗

Pelvic neurectomy abolishes the fetus-expulsion reflex and induces dystocia in the rat.

To clarify the origin of dystocia in bilaterally pelvic neurectomized (BPN) rats, the uterine activity during the periparturient period, and reflex straining movements in response to vaginal stimulation and cervical extensibility were monitored. The BPN rat displayed "stretching" movements and the regular continuous uterine activity with a similar onset and intensity to that in control rats (intact, sham-operated or unilateral pelvic neurectomized rats) on days 22 or 23 of gestation, but lacked the "straining" movements which precede each delivery of pups in controls so that parturition was prolonged. Dissection of rats revealed that an unborn fetus was retained in the expanded upper portion of the vaginal cavity. Vaginal distension induced contraction of the abdominal muscles and diaphragm and an inhibition of respiratory movements, resulting in an increase in intraabdominal pressure in urethane-anesthetized control rats. This reflex muscular contraction which reflects the straining movements in normal delivery may be called the fetus-expulsion reflex and does not occur in BPN rats. It differs from the fetus-ejection reflex (Ferguson reflex) which initiates oxytocin release. There was no difference in weight and distensibility of the uterine cervix between sham-operated and operated rats on day 22 of pregnancy. The results suggest that the main abnormality of delivery in BPN rats, a prolongation of the process of delivery, may be due to a lack of the fetus-expulsion reflex which plays a physiologic role in removing a fetus from the upper vaginal cavity against the resistance of the pelvic outlet.

Animals↗

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↗

Facilitatory effect of antidromic stimulation on milk ejection-related activation of oxytocin neurons during suckling in the rat.

Oxytocin neurons of the paraventricular nucleus were identified by their antidromic response to stimulation of the neurohypophysis and a short high-frequency burst of spikes displayed before reflex milk ejection in the urethane-anesthetized lactating rat. During suckling, the milk ejection-related bursts recurred at regular intervals. Stimulation of the neurohypophysis at 50-300 pulses/s for 0.5-6 s (current 1 mA) evoked additional burst(s) with the amplitude higher than those of spontaneously occurring ones. Stimulation with subthreshold current for antidromic response or constant-collision test could also facilitate the neurosecretory bursts. Possibly, oxytocin released within the magnocellular nuclei is responsible for these effects.

Animals↗

Effect of microelectrophoretically applied acetylcholine, noradrenaline, dopamine and serotonin on the discharge of paraventricular oxytocinergic neurones in the rat.

The effects of microelectrophoretic applications of neurotransmitter substances and their antagonists on the activity of paraventricular oxytocinergic neurones were studied in urethane anesthetized lactating rats. Oxytocinergic neurones were identified by their antidromic response to the stimulation of the neurohypophysis and by their characteristic high frequency discharge of action potentials approximately 15-20s before reflex milk ejection. Acetylcholine (ACh) excited the majority (75%) of paraventricular oxytocinergic neurones, and none of the cells was inhibited in its activity by ACh. In about half of the oxytocinergic cells, atropine and hexamethonium reduced the number of action potentials during the burst discharge preceding reflex milk ejection. Noradrenaline (NE), dopamine (DA) and serotonin (5-HT) reduced the activity of most (75-100%) of oxytocinergic neurones, and none of the cells was excited by these catecholamines. These results suggest that paraventricular oxytocinergic neurones receive excitatory cholinergic inputs and inhibitory noradrenergic, dopaminergic and serotonergic inputs.

Acetylcholine↗

Functional development of the oxytocin release mechanism and its role in the initiation of parturition in the rat.

Developmental changes in levels of oxytocin in the blood and the pituitary gland and in oxytocin responses to oxytocin-releasing stimuli were investigated in the rat from the fetus close to term to the 40-day-old young adult. The oxytocin content of the pituitary gland rose gradually from fetuses of 21 days of gestation to 40-day-old rats. Pituitary oxytocin levels expressed in terms of body weight also increased up to day 25 after birth and declined slightly thereafter. In contrast, serum concentrations of oxytocin increased from day 21 of pregnancy up to day 5 after birth but were stable thereafter. Oxytocin levels in both blood and the pituitary gland were equal in 23-day-old fetuses and 1-day-old infants born on day 22 of pregnancy. There was no difference in serum and pituitary oxytocin levels in newborn pups and unborn littermates of day 22 or 23 of gestation. The i.p. injection of hypertonic saline induced a significant increase in serum oxytocin levels on day 5 and later, but no effect in the fetus on day 22 of gestation and in the 1-day-old infant. The responsiveness to the osmotic stimuli increased after 5 days of age. The i.p. injection of diethyldithiocarbamate, a noradrenaline synthesis inhibitor, or phenobarbitone was effective in raising blood oxytocin levels only in rats older than 10 and 20 days of age respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗

The possible effect of pregnancy on Ménière's disease.

There are few reports on the course of Ménière's disease during pregnancy. We report here the clinical course of Ménière's disease before, during and after pregnancy and discuss the possible effect of pregnancy on Ménière's disease and the treatment of Ménière's disease during pregnancy. In the present case, the vertigo attacks increased up to 10 times per month during early pregnancy, when the serum osmolality was significantly below normal at 268 mosm/kg. As the pregnancy proceeded, the serum osmolality normalized and the vertigo attacks decreased in frequency. The vertigo attacks were treated by oral isosorbide and intramuscular injection of low-dose diazepam. The coincidence of the decline in osmolality with the increase in vertigo attacks points to serum osmolality as a possible factor in the effect of pregnancy on Ménière's disease.

Adult↗