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Biomedical subjects

M Imai

Publications and source records attributed to M Imai.

730 records · Page 41Linked to original sources
PubMedDate not supplied

Enzymatic activity and expression of cytochrome P450 LA omega within intrasplenically transplanted fetal hepatocytes in spontaneously hypertensive rats.

We examined the expression and enzymatic activity of cytochrome P450 LA omega within transplanted hepatocytes. Fetal hepatocytes were harvested at day 20 of gestation from spontaneously hypertensive rats (SHRs) and transplanted into recipient adult SHR spleens. Microscopic examination of the recipient spleens at 4 and 10 wk after transplantation revealed masses of hepatocytes with cord-like structures in the red pulp. Immunochemical studies detected cytochrome (cyto) P450 LA omega in the fetal hepatocytes before transplantation without prior induction. Although the cyto P450 LA omega was not detected by the second week after transplantation, by the 6th and 10th wk after transplantation, it was. Cyto P450-arachidonic acid omega/omega-1 hydroxylase activity (formation of 20- and 19-hydroxyeicosatetraenoic acid) was detected at 10 wk after transplantation, but not 2 or 6 wk after transplantation. These results demonstrated that fetal hepatocytes can be transplanted successfully into recipient spleens and then grow in the spleens, as in the case of the adult hepatocyte response.

Animals↗
PubMedDate not supplied

Differential effects of yohimbine, naloxone and 8-OH-DPAT on ejaculatory response in male dogs.

The aim of this study was to compare the effects of the alpha(2)-adrenergic-receptor antagonist yohimbine, the 5-HT(lA)-receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) and the opioid-receptor antagonist naloxone (all of which have been shown to stimulate male sexual arousal/motivation in rats) on sexual responses in male dogs. Sexual responses (i.e., ejaculation, penile erection and pelvic thrusting behavior) were elicited by manual penile stimulation. Systemic administration of yohimbine (0.03-1.0 mg/kg) produced a biphasic dose response curve for the amount of ejaculated semen collected during genital stimulation (for 5 min), whereas 8-OH-DPAT (0.03-0.3 mg/kg) dose-dependently decreased the amount of ejaculated semen. Thus, yohimbine increased the amount of ejaculated semen at lower doses (0.03-0.3 mg/kg), but decreased it at the highest dose (1.0 mg/kg). The highest dose of yohimbine (1.0 mg/kg) and 8-OH-DPAT (0.3 mg/kg) also produced a significant delay of onset in both ejaculation and penile erection latency (time from starting the stimulation to the first ejaculation and full erection), and a decrease in the incidence of pelvic thrusting behavior. In contrast, administration of naloxone (0.03-1.0 mg/kg) did not affect the sexual responses elicited by genital stimulation. These results indicate that yohimbine and 8-OH-DPAT, but not naloxone, affect sexual responses, particularly ejaculation, and that the drugs which stimulate the mechanisms regulating sexual arousal/motivation in male rats do not show identical effects for sexual function in male dogs. The present findings also confirm our previous observations that the ejaculatory capacity in dogs can be stimulated by lower doses of yohimbine, as evidenced by an increase in the amount of ejaculated semen.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMedDate not supplied

Spontaneous rupture of bladder diverticulum after postoperative radiotherapy for carcinoma of the uterine cervix: a case report.

We present a case of spontaneous rupture of bladder diverticulum three years after postoperative whole pelvic irradiation (50.4 Gy) for carcinoma of the uterine cervix. The patient had suffered from a neurogenic bladder after hysterectomy, but excretory urography revealed no abnormalities. Bladder diverticulum was found two years later. Spontaneous rupture of the urinary bladder is one of the late complications associated with radiotherapy, although it is very rare. Postoperative neurogenic bladder may also be associated with rupture. We should be aware of this rare complication in patients who receive pelvic irradiation.

Aged↗
PubMedDate not supplied

Post-transfusion graft-versus-host disease following open heart surgery. Report of six cases.

Six cases of post-operative erythroderma after open heart surgery are described. About 10 days after seemingly uneventful recovery, all patients developed fever, erythroderma, liver enzyme elevation, pancytopenia, and an aplastic bone marrow. Their condition rapidly deteriorated, and they died within 20 days of the onset of symptoms. Skin biopsy specimens from two patients showed mild leukocytic infiltration in the epidermal basal layer and upper dermis. Immunostaining by the ABC method showed that most of these infiltrating cells were suppressor/cytotoxic T cells. HLA study of peripheral lymphocytes from two patients and their families revealed that the patients' HLA phenotypes were incompatible from their children's HLA findings. Y chromatin was present in the lymphocytes of the skin biopsy specimen of a female patient. Based on the clinical picture, skin biopsy, HLA study, and Y chromatin study, the authors strongly suspect post-transfusion GVHD as the etiology of postoperative erythroderma, although these patients lacked any known immunodeficiency.

Adult↗
PubMedDate not supplied

Three-dimensional movements of a maxillary complete denture: the development of a measuring system and preliminary measurement.

To measure the movements of a maxillary denture in vivo it is necessary to analyze the three-dimensional displacements induced. A measuring system consisting of four main units (a magnetic sensor, three optical fiber sensors, a sensor-setting jig, and a recorder) was developed. Using this system, the movements of a maxillary denture were continuously measured during tapping and during the mastication of a peanut.

Aged↗
PubMedDate not supplied

Effect of intracellular unstirred layer on apparent reflection coefficient for urea in inner medullary collecting duct: a computer simulation.

In the vasopressin-stimulated inner medullary collecting duct (IMCD), urea is transported through a pathway which is distinct from a water channel. Therefore, no frictional interaction between urea and water should occur at the membrane level, and the reflection coefficient for urea must be close to unity. However, the presence of unstirred layers in the vicinity of membranes causes solute concentration polarization, leading to an underestimation of the reflection coefficient (apparent reflection coefficient). When the value is determined across the perfused renal tubular wall, the intracellular space also constitutes an unstirred layer. The profile of solute and water transport across the system consisting of two membranes and the interposed intracellular space was simulated by a computer to examine the effect of unstirred layer on the value of apparent reflection coefficient. The model demonstrated that the imposed osmotic gradient across the tubular epithelial is decreased at each membrane interface. Under conditions of minimal unstirred layers in the bathing fluid, the existence of the intracellular constraints to diffusion cause considerable underestimation of the reflection coefficient. The higher the membrane permeability of urea and the smaller the diffusion coefficient of urea in the intracellular space, the greater becomes the magnitude of the underestimation. Thus, the measured apparent reflection coefficient for urea may become significantly less than the estimated value, leading to a reduction of the effective transmural osmotic driving force.

Animals↗
PubMedDate not supplied

Further electrophysiological characterization of the alpha- and beta-intercalated cells along the rabbit distal nephron segments: effects of inhibitors.

To further characterize the alpha- and beta-intercalated cells (alpha-IC, beta-IC) in the isolated and perfused connecting tubule (CNT), cortical collecting duct (CCD) and outer medullary collecting duct in the inner stripe (OMCDi) of rabbit kidneys, we studied the effects of various transport inhibitors on electrical parameters. They included inhibitors of Cl-/HCO3- exchanger (4-acetamino-4'-isothiocyanostilbene-2,2'-disulfonic acid, SITS), carbonic anhydrase (acetazolamide) and Na(+)-K(+)-ATPase (ouabain). Upon addition of 10(-3) M SITS to the bath, the basolateral membrane voltage (VB) of alpha-IC in the OMCDi and CCD was significantly hyperpolarized by 20.8 +/- 4.6 (n = 5) and 29.8 +/- 5.6 mV (n = 11), respectively. On the other hand, luminal addition of SITS had no effects on VB of alpha-IC in the OMCDi and CCD. Neither bath nor lumen SITS affected VB of beta-IC in the CCD and CNT. When 10(-4) M acetazolamide was added to the bath, VB of alpha-IC in the OMCDi and CCD was significantly hyperpolarized by 20.0 +/- 4.1 (n = 4) and 18.6 +/- 1.7 mV (n = 3), respectively. Similarly, 10(-4) M acetazolamide in the bath caused the basolateral membrane of beta-IC in the CCD and CNT to hyperpolarize significantly by 34.3 +/- 7.9 (n = 6) and 21.6 +/- 2.9 mV (n = 3), respectively. Luminal addition of acetazolamide had no effect on VB of alpha-IC in the CCD and OMCDi and beta-IC in the CCD and CNT.(ABSTRACT TRUNCATED AT 250 WORDS)

4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfo↗
PubMedDate not supplied

[Mothers attending hospitalized children: using Leininger's ethnonursing method].

The purpose of this study was to discover the views of mothers with hospitalized children. Leininger's mini-ethnonursing method was used to explore and describe the views of Japanese mothers. A children's unit of a general hospital in Kanto in Japan was used for the field research. Six mothers who were with their hospitalized children were selected as the key informants. And 14 staff members on the unit including nurses, physicians, and nurse aides, were selected as the general informants. From nearly 140 days of observation-participation and reflection (Leininger enabler), the following themes were discovered; Theme 1: The mothers wanted to be close to their children (like tied to their navel string) and to be the only persons who could stay continually with their hospitalized child. Theme 2: The mothers tried to do everything by themselves, because they thought nurses were too busy and, therefore, they could not leave their children alone. They still wanted the nurses to help the child when they needed a long-term care at the hospital. Theme 3: The mothers expected an assurance of the life of their child and wanted an effective treatment from physicians, but held there was no one to consult fully with about their children's illness. Theme 4: Mothers searched companions who had the similar feelings and views, but didn't ask about their children's diagnosis. Theme 5: The mothers believed they had limited knowledge about prevention of an infection, but they tried to prevent by infection. Theme 6: The mothers were unaware of their fatigue and neglected to rest, sleep, and eat properly while child was hospitalized. Theme 7: The mothers did not expect their husbands to stay with their children, but expected their own mothers to help them. Theme 8: The mothers believed that nobody could explain and advise them about their daily life at the hospital, the medical systems and to reassure them. A recurrent theme was that "mothers took for granted that they must stay with" or "hold out" for their hospitalized child.

Adult↗
PubMedDate not supplied

Temporary cement remnants as an adhesion inhibiting factor in the interface between resin cements and bovine dentin.

This study investigated the effect of temporary cement remnants on freshly prepared dentin in the adhesion of resin cements. The tensile bond strength of three types of resin cements to dentin were measured in a control group and after the application of two types of temporary cement. Scanning electron microscopy and energy dispersive x-ray spectroscopy were used to confirm the presence of temporary cement remnants. Overall results suggest that temporary cement application significantly decreased the tensile bond strength in all adhesive systems (P = 0.0001, analysis of variance). Scanning electron micrographs presented granular elements on the dentin surfaces treated with temporary cement even after preconditioning. Energy dispersive x-ray spectroscopy results showed the presence of zinc peaks in the specimens that was not present in the control.

Adhesiveness↗