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Biomedical subjects

Y Kamei

Publications and source records attributed to Y Kamei.

At least 73 records · Page 4Linked to original sources

Plasma levels of interleukin-1 receptor antagonist (IL-1ra) and severity of illness in patients with burns.

The present study was conducted to determine whether a plasma interleukin-1 receptor antagonist (IL-1ra) would reflect the severity of burn injury and to examine the relation between IL-1ra and the cytokines. We studied 24 burn patients in whom the total burn surface area (TBSA) accounted for at least 20% of the body surface, and in whom serial blood samples could be obtained beginning immediately after the burn injury. Plasma levels of IL-1ra were determined by enzyme-linked immunosorbent assay (ELISA). Plasma levels of tumor necrosis factor-alpha (TNF-alpha), IL-6, and IL-8 were also determined by ELISA. Endotoxin was measured by an endotoxin-specific synthetic substrate method. There was a significant correlation between the plasma levels of IL-1ra and TBSA during the first week following burn injury. The IL-1ra level was the highest immediately after the burn injury. The level decreased markedly thereafter, and again rose when infection occurred. The IL-1ra level was extraordinarily elevated in patients who developed concomitant sepsis, septic shock or the septic multiple organ dysfunction syndrome. The IL-1ra level on admission and the maximum IL-1ra level during the observation period were significantly higher in the patients who eventually died than in the survivors. There was a significant correlation between the level of IL-1ra and that of TNF-alpha, IL-6 or IL-8 during the observation period. No correlation was found between IL-1ra and endotoxin. The plasma IL-1ra level was closely correlated with the severity of inflammation and the clinical status of the burn patients, regardless of the infection. Results suggest that IL-1ra can serve as an index of the systemic inflammatory response syndrome (SIRS).

Adult↗

Ligand-independent repression by the thyroid hormone receptor mediated by a nuclear receptor co-repressor.

Thyroid-hormone and retinoic-acid receptors exert their regulatory functions by acting as both activators and repressors of gene expression. A nuclear receptor co-repressor (N-CoR) of relative molecular mass 270K has been identified which mediates ligand-independent inhibition of gene transcription by these receptors, suggesting that the molecular mechanisms of repression by thyroid-hormone and retinoic-acid receptors are analogous to the co-repressor-dependent transcriptional inhibitory mechanisms of yeast and Drosophila.

Amino Acid Sequence↗

Cloning and sequencing of the gene encoding the mouse vitamin D receptor.

The mouse vitamin D receptor (VDR)-encoding cDNA was cloned and the coding regions were sequenced. Comparison of the amino-acid sequence to that of humans and rats revealed high homology in the DNA- and ligand-binding domains. Divergence appeared in the internal region between the two domains.

Amino Acid Sequence↗

Tractional elevation of Henle's fiber layer in idiopathic macular holes.

PURPOSE: We sought to clarify the morphologic features of macular hole development. METHODS: Using scanning laser ophthalmoscopy, we examined 47 eyes with macular holes before and after vitrectomy. Cases included three eyes with stage 1B disease (foveal detachment), 14 with stage 2 (break at the fovea), 21 with stage 3 (full-thickness macular hole), and nine with stage 4 (detached operculum), according to Gass's classification. Ten eyes with central serous chorioretinopathy served as controls. RESULTS: Radiating striae of Henle's fibers were seen around the elevated rim of the macular cyst or hole when the intraretinal structures were illuminated by helium-neon laser. Granularity was observed on the macular hole floor. A granular reflex corresponding to the macular break or hole, but no radiating striae were seen by argon blue laser. In 40 eyes in which macular holes were successfully closed by vitrectomy, radiating striae of Henle's fiber layer disappeared, and the normal foveal depression was restored. The ten eyes with central serous chorioretinopathy had a normal foveolar depression and no detectable radiating striae of Henle's fiber layer, despite full-thickness retinal detachment in the macular area. CONCLUSIONS: Tractional elevation of Henle's fiber layer with intraretinal foveolar cyst formation is the initial feature of macular hole development. A macular hole is formed when the anterior cyst wall containing Henle's fiber layer is operculated. Remnants of the photoreceptor cell layer remain on the hole floor in the early stage of macular hole development and subsequently degenerate.

Adult↗

Infrared angiography of the anterior ocular segment.

We performed angiography with indocyanine green (ICG) and fluorescein using a scanning laser ophthalmoscope (SLO) in the anterior segments of seven normal and 35 diseased eyes. ICG angiography revealed the radical stromal vessels and minor arterial circle in brown irides, which were not detected by fluorescein angiography. High penetration of infrared fluorescence through the pigmented tissue and absence of extravasation of ICG facilitated demonstration of the fine structure of iris rubeosis and its origins from stromal vessels. In 11 diabetic eyes, the iris rubeosis showed three basic patterns of location: along the pupillary margin; originating from the iris root; and arising from stromal radial vessels near the collarette. ICG gonioangiography with SLO showed fine structure of angle rubeosis because of its high resolution and greater depth in focus. Rubeotic vessels in the chamber angle were perfused by neovascular trunks which arose from the iris root in all 12 rubeotic eyes. Rubeosis in the iris and the angle consistently showed no extravasation of the ICG dye, while fluorescein quickly leaked out. ICG angiography with SLO in the anterior ocular segment proved to be a useful means to study the structure and the hemodynamics of normal and newly formed vessels.

Adult↗

Anterior cranial base reconstruction using a hydroxyapatite-tricalciumphosphate composite (Ceratite) as a bone substitute.

The craniofacial approach to cranial base tumors has widened the operability of tumors with intracranial invasion. However, the resulting skull base defect must be reconstructed adequately to prevent postoperative morbidity and mortality. We use hydroxyapatite-tricalciumphosphate ceramic (Ceratite) as a bone substitute material to reconstruct the skull base defect in combination with the pericranial flap, ensuring separation between the sinonasal cavity and epidural cavity. Although the nasal surface of the Ceratite block is left exposed directly to the sinonasal cavity, it was shown to be epithelialized within 6 months postoperatively. Our method is less invasive than any other conventional method and may offer more chance of curative resection of tumors with anterior skull base invasion.

Adenocarcinoma↗

The prevention of adipose differentiation of 3T3-L1 cells caused by retinoic acid is elicited through retinoic acid receptor alpha.

Retinoids, especially all-trans retinoic acid (RA), have been shown to inhibit the differentiation of preadipose cells. It is important to human health, especially to obesity, that the regulatory system for the differentiation of adipocytes is well defined. Previously, we have shown that retinoic acid receptor (RAR) gamma 2 gene expression is up-regulated by RA in 3T3-L1 preadipose cells. In this study, the RAR system was dissected and the RA-regulated function in 3T3-L1 cells was assigned to one given receptor. We used three synthetic retinoids; (1) Ro 41-5253, a selective RAR alpha antagonist, (2) Ch 55, an RAR alpha, beta and gamma agonist, and (3) Am 80, an RAR alpha and beta agonist, which has less affinity to RAR gamma. Ro 41-5253 reverted RA-induced inhibition of the differentiation of 3T3-L1 cells. However, there was no significant reversion in RA-induced RAR gamma mRNA level by treatment with Ro 41-5253. In the case of RAR agonists, both Am 80 and Ch 55 strongly inhibited the differentiation of 3T3-L1 cells. However, Am 80 weakly increased RAR gamma mRNA content less than did Ch 55. These findings suggest, that RAR alpha is involved in the prevention of adipose differentiation by RA in 3T3-L1 cells. Moreover, there seems no causal relationship between the prevention of adipose differentiation by RA and the up-regulation of RAR gamma 2 gene expression by RA in 3T3-L1 cells. We have shown the functional heterogeneity of RA action through different RARs in 3T3-L1 cells.

3T3 Cells↗

Composite gastric seromuscular and omental pedicle flap for urethral and scrotal reconstruction after Fournier's gangrene.

A new composite gastric seromuscular and omental pedicle flap is described that can provide immediate airtight or watertight closure in the repair of complex defects involving the urethra. This flap was used to repair defects of the urethra, scrotum, and abdominal wall in a patient with Fournier's gangrene. The seromuscular patch was sutured to the urethral defect, and the omentum was applied over the defects of the scrotum and abdominal wall. This new procedure made it possible to close the skin primarily without leakage or infection. The patient had an uncomplicated recovery. Postoperative urethrography demonstrated no leakage or stenosis.

Abdominal Muscles↗

A new composite gastric seromuscular and omental pedicle flap.

OBJECTIVE: The authors performed a study to see if gastric seromuscular patch elevation is anatomically feasible and to estimate the maximum size of the patch relative to its blood supply. SUMMARY BACKGROUND DATA: A flap composed of greater omentum and a full-thickness segment of the greater curvature of the stomach, based on the right gastroepiploic artery, was first described in 1977. Elevation of the greater omentum along with a seromuscular patch of stomach has not been reported previously. METHODS: Angiography was performed via the right gastroepiploic artery in a stomach obtained from ten patients who underwent gastrectomy, then india ink was injected. The stomach was then fixed in 10% formalin, and histochemical examination was performed to determine if seromuscular patch elevation was possible. RESULT: Results of the angiography and injection experiment of india ink indicated that the territory of a single gastric ramus was approximately 5 cm x 5 cm in both anterior and posterior walls of the stomach. Histology revealed that the gastric rami lay between the muscular layer and the mucosa. CONCLUSION: The authors believed that a composite gastric seromuscular patch and omental pedicle flap would be clinically applicable. The authors also believed that the maximum size of the patch was 10 cm x 10 cm. They used this flap to successfully treat three patients with chronic soft-tissue defects--two bronchopleural fistulae and a radiation ulcer.

Aged↗

Retinoic acid receptor gamma 2 gene expression is up-regulated by retinoic acid in 3T3-L1 preadipocytes.

Retinoids, especially all-trans retinoic acid (RA), have been shown to inhibit the differentiation of preadipose cells. In the present study, the expression of retinoic acid receptors (RAR alpha, beta and gamma) and retinoid X receptors (RXR alpha, beta and gamma) was examined by Northern blot analysis in rat adipose tissue and mouse 3T3-L1 adipose cells. The adipose tissue and/or 3T3-L1 cells expressed mRNAs for a number of nuclear retinoid receptors, including RAR alpha, beta and gamma, and RXR alpha, beta and gamma. RAR alpha, RAR gamma, RXR alpha and RXR beta mRNAs were abundant in adipose tissue and 3T3-L1 cells. RXR gamma mRNA was detected in adipose tissue but not in 3T3-L1 cells. Treatment of 3T3-L1 cells with 1 microM RA led to a 4-5-fold increase in the RAR gamma mRNA level, but only a trace amount of RAR beta mRNA was detected. RAR gamma mRNA expression was rapidly (within 2 h) induced by physiological concentrations of RA in a dose-dependent manner. The response of RAR gamma mRNA expression to RA was reversible; rapid disappearance of RAR gamma mRNA occurred on RA removal. In addition, the induction of RAR gamma expression did not require de novo protein synthesis, but was completely abolished by an inhibitor of RNA synthesis. Using RAR gamma 1 and gamma 2 isoform-specific probes, the patterns of RAR gamma 1 and gamma 2 mRNA expression in 3T3-L1 cells in the presence and absence of RA were examined. RAR gamma 1 mRNA was detected in 3T3-L1 cells but was not affected by RA treatment; however, RAR gamma 2 mRNA was strongly induced by RA.

3T3 Cells↗

Vitamin D receptor gene expression is up-regulated by 1, 25-dihydroxyvitamin D3 in 3T3-L1 preadipocytes.

Vitamin D3, especially 1, 25-dihydroxyvitamin D3 (1, 25 (OH)2 D3), has been shown to inhibit the differentiation of preadipose cells. In the present study, the expression of vitamin D receptor (VDR) was examined by Northern blot analysis in rat adipose tissue and mouse 3T3-L1 adipose cells. The adipose tissue and 3T3-L1 cells expressed mRNA for VDR. Treatment of 3T3-L1 cells with 1 microM 1, 25 (OH)2 D3 led to a 4-5 fold increase in the VDR mRNA level. VDR mRNA expression was rapidly (within 4 hr) induced by physiological concentrations of 1,25 (OH)2 D3 in a dose-dependent manner. The induction of VDR expression did not require de novo protein synthesis but was completely abolished by an inhibitor of RNA synthesis.

3T3 Cells↗

Effect of pravastatin on human sleep.

To evaluate the effect of pravastatin, an HMG-CoA reductase inhibitor, on sleep, the drug or a placebo was administered to 5 healthy adults for 16 days by the double-blind method. Pravastatin caused no changes in sleep parameters. This indicates that it had no effect on human sleep for the following possible reasons: Being hydrophilic, the drug does not readily cross the blood-brain barrier. It does not inhibit prostaglandin D2 synthase, a possible sleep-inducing substance. It was thought that a decrease in the total cholesterol level in the blood has no effect on sleep in healthy adults.

Adult↗

Intrauterine growth retardation and fetal losses are caused by epidermal growth factor deficiency in mice.

The plasma concentration of epidermal growth factor (EGF) in female mice increases during pregnancy. Sialoadenectomy (surgical removal of the submandibular glands) on day 13 of gestation attenuates the rise in plasma EGF and significantly reduces the percent of live pups on day 19 of pregnancy to 80% compared with 95% for the control animals. EGF replacement therapy given to the sialoadenectomized mice successfully prevented this reduction in the percent of live pups on day 19. The average weight of the live fetuses from sialoadenectomized mothers was significantly lower than those from the control mothers, i.e., 1.00 +/- 0.14 (SD) g vs. 1.13 +/- 0.07 g. The administration of anti-EGF antiserum to the sialoadenectomized mice further affected fetal viability; only 70% of the pups were alive on day 19, with a mean weight of 0.93 +/- 0.15 g. The mean weight of the fetal body and that of the liver caused by sialoadenectomy were similarly reduced, but the brain was not affected, which shows that the growth retardation was asymmetrical. These findings suggest that EGF plays a physiological role in fetal growth and that EGF deficiency may be a cause of asymmetrical intrauterine growth retardation, which might be due to uteroplacental dysfunction.

Animals↗

[Clinical results of radical surgery for prostate cancer].

We reported the clinical results of radical surgeries for 44 patients with prostate cancer performed between November 1984 and December 1992. The patients were aged from 57 to 79-year-old (mean 67.2) and classified as clinical stage A2 (6 cases), B1 (7), B2 (12), C (16) and D1 (3) respectively. Radical prostatectomy was performed in 42 cases and radical cystoprostatectomy with urinary diversion in 2 patients, and thirty-nine of 44 cases underwent endocrine or chemoendocrine therapies prior to the surgeries. In all patients with stage A2-B1, the operations were curative, on the other hand, more than 80% of clinical stage B2 patients had pT3 tumors and 33.3% of them had lymph node involvements. With regard to stage C patients, the incidence of lymph node metastasis and positive margin was more frequent. Postoperative adjuvant therapies were added to the patients with pT3,4 tumors and nodal involvements. Patients without residual tumors (n = 20) remained disease-free for 8-89 months (mean 32.8). Of 24 patients who had incomplete resection of tumors, 2 died of other diseases, other 2 were alive recurrent and 20 were alive free from disease for 3-99 months (mean 33.8). The surgical indication for low-stage (A2-B2) prostate cancer has been widely accepted, however that for high-stage cancer (C,D1) has remained controversial. It was our belief that radical surgeries for high-stage cancer could become a potentially curative therapeutic modality in combination with pre- and post-operative adjuvant therapies.

Aged↗

The phenol red thread tear test: a cross-cultural study.

PURPOSE: To examine the results of the phenol red thread tear test in a cross-cultural comparison. METHODS: Two groups of 500 controlled normal subjects who do not wear contact lenses from the United States and Japan were investigated. RESULTS: The mean wet length of the thread for the United States was 23.9 mm (SD 9.5 mm). The mean for Japan was 18.8 mm (SD 8.6 mm). There was a significant difference between the two countries (P < 0.05). Males subjects had significantly longer wet lengths than females for both countries (P < 0.05). There was a moderate correlation between right and left eye results for both countries. CONCLUSIONS: The phenol red thread tear test was found to be easy to administer. Results were in line with current knowledge and theories of the lacrimal system. Results also indicated that this test may disclose subtle differences not previously found with other tear tests.

Adolescent↗