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Biomedical subjects

S Matsubara

Publications and source records attributed to S Matsubara.

At least 127 records · Page 7Linked to original sources
PubMed1999

Water quality management for low temperature marine fishes in space.

Vestibular Function Experiment Unit (VFEU), one of the Spacelab facility flown in Neurolab mission (STS-90) in April, 1998, was to support neurophysiological research using a marine fish, Opsanus tau (oyster toadfish). The functions of the VFEU were primarily a quality management of environmental water during the mission at 14 degrees C and for acquiring physiological signals from implanted micro-electrodes in the otolith nerves as well as the spatial acceleration of the fish. A key element of the life support system was a balanced biological filter containing two types of nitrifying bacteria, Nitrosomonas for ammonia oxidization and Nitrobacter for nitrite oxidization. Although the 16 days mission was successful, two toadfishes died in late phase of the mission. Ammonium concentration in those two life support systems elevated to remarkably high level at the end of the mission whereas the other two indicated very low. This report summarizes the results of the water quality management of the VFEU during the Neurolab mission based on analysis of water samples taken during the flight and those taken prior and just after the flight.

Animals↗
PubMed1999

Using helical CT to evaluate renal cell carcinoma in patients undergoing hemodialysis: value of early enhanced images.

OBJECTIVE: The purpose of this study was to evaluate early and delayed enhanced helical CT for revealing renal cell carcinoma in patients undergoing hemodialysis. MATERIALS AND METHODS: Over the course of 3 years, 630 chronic hemodialysis patients underwent early and delayed contrast-enhanced and unenhanced helical CT to detect renal cell carcinoma. Retrospective review showed that 23 of these patients later underwent either unilateral or bilateral nephrectomy. Two radiologists, unaware of the pathology results, independently reviewed these 23 examinations. The sensitivity and specificity of each early and delayed scan for revealing neoplasms were determined using pathology as the gold standard. The mean attenuation values of the neoplasms and parenchymas of end-stage kidneys on both early and delayed enhanced images were also compared. RESULTS: Helical CT revealed 225 lesions, 24 of which were found to be renal cell carcinomas at pathology. Delayed enhanced helical CT failed to detect one papillary carcinoma in an end-stage kidney with acquired cysts. Three nonpapillary carcinomas were not detected on delayed scans, and one was missed on an early scan of a patient without acquired cysts. The sensitivity and specificity of early enhanced CT for revealing renal cell carcinoma were 96% and 95%, respectively. In contrast, delayed enhanced CT achieved a sensitivity of 83% and a specificity of 94%. A significant difference in mean attenuation values between carcinomas and renal parenchymas was observed on the images with early enhancement but not on those with delayed enhancement (p < .0001). CONCLUSION: Early enhanced helical CT is superior to delayed enhanced helical CT for revealing renal cell carcinoma in end-stage kidneys.

Carcinoma, Renal Cell↗
PubMed1999

[Uptake of 201TlCl and 99mTc-tetrofosmin in neurofibroma: a case report].

A 34-year-old man with neurofibromatosis type 1 (von Recklinghausen's disease) was examined by 201TlCl and 99mTc-tetrofosmin scintigraphies. Hypervascularity was observed in the largest tumor of the right thigh. The tumor was also depicted on both scintigrams. Tumorectomy was performed and the pathologic examination revealed it to be a neurofibroma measuring 10 x 7 x 4 cm in size. These findings suggested that 201TlCl and 99mTc-tetrofosmin scintigraphies generally were unable to distinguish malignant from benign neurofibromas with certainty.

Adult↗
PubMed1999

Computerized tomography nephroscopic images of renal pelvic carcinoma.

PURPOSE: Computerized tomography (CT) endoscopy is an interactive 3-dimensional image acquired by helical CT. We assess the usefulness of CT nephroscopy in the diagnosis of renal pelvic cancers. MATERIALS AND METHODS: Surface rendering CT nephroscopy was performed after intravenous administration of contrast agent and furosemide in 32 patients with suspected renal pelvic carcinoma. Retrospective review revealed that 23 patients later underwent nephroureterectomy. Two observers blinded to the pathology results independently reviewed the CT nephroscopic and axial CT images of the 23 patients to localize pelvic tumors and to determine the extent of the disease. The CT nephroscopic and axial CT images were correlated with the pathological findings. RESULTS: Pathological examination revealed 4 polypoid, 6 pedunculated, 7 sessile, 1 sessile with ulceration and 6 infiltrating renal pelvic carcinomas in the 23 patients. CT nephroscopy revealed 22 carcinomas (92%) and CT demonstrated 20 (83%). CT nephroscopy was superior to axial CT in detecting 4 pedunculated and 3 infiltrating carcinomas but failed to detect 1 sessile carcinoma which completely replaced the upper portion of a double renal pelvis and 1 polypoid tumor associated with infiltrating carcinoma. The CT nephroscopic images correlated well with pathological findings. CONCLUSIONS: CT nephroscopy is useful to visualize the complex morphology of renal pelvic carcinomas noninvasively and is superior to axial CT for the detection of infiltrating and pedunculated carcinomas.

Adult↗
PubMed1999

Effects of placental chorionicity on outcome in twin pregnancies. A cohort study.

OBJECTIVE: To examine the effects of the chorionicity of the placenta on infant outcome at 1 year of age in twin pregnancies. STUDY DESIGN: Cohort study and retrospective review of the medical records of 44 monochorionic (MC) and 164 dichorionic (DC) twin gestations that had been followed at our institution since < 20 weeks' gestation. Physical and neurologic status was assessed at 1 year of corrected age in infants born to these 208 women. RESULTS: Adverse infant outcomes, such as death, cerebral palsy and mental retardation, occurred in 9 (10%) of 88 MC infants (4 deaths and 5 disabled infants) as compared with 12 (3.7%) of 328 DC infants (6 deaths and 6 disabled infants) (P < .05). Although delivery occurred one week earlier in MC than in DC twins (34.7 +/- 2.8 vs. 35.7 +/- 2.3 weeks, P < .01), there was no significant difference in gestational age at birth or birth weight between the 9 MC and 12 DC infants with adverse outcomes. A presumptive antenatal diagnosis of twin-twin transfusion syndrome (TTTS) was made in 14 (32%) of the 44 MC twin gestations. TTTS was considered to be responsible for adverse outcome in 7 MC infants. All 9 MC infants with adverse outcomes and 4 (33%) of 12 DC infants with adverse outcomes belonged to pairs that had weight discordance > or = 25% (P < .01). CONCLUSION: MC twins had an increased risk of adverse outcomes as compared with DC twins, mainly because of TTTS. In both MC and DC twins, a birth weight discordance > or = 25% was associated with adverse infant outcomes. The number of infants with disabilities at 1 year of age was equal to the number of deaths.

Adult↗
PubMed1999

Meconium-stained amniotic fluid activates polymorphonuclear leukocytes ultrastructural and enzyme-cytochemical evidence.

The purpose of the present study was to demonstrate morphological evidence that meconium-stained amniotic fluid activates polymorphonuclear leukocytes. We used Boyden chamber techniques to determine the chemotactic activity of meconium-stained amniotic fluid for leukocytes, and ultrastructural enzyme-cytochemistry for peroxidase and alkaline phosphatase to characterize the leukocyte features induced by contact with meconium-stained amniotic fluid. Amniotic fluid with meconium staining enhanced migration of leukocytes. These leukocytes exhibited more numerous cytoplasmic processes and more prominent phagosomes compared to peripheral blood leukocytes. Peroxidase and alkaline phosphatase activity were evident on the phagosomal membranes. Our results indicate that meconium-stained amniotic fluid activates or stimulates polymorphonuclear leukocytes. Meconium-stained amniotic fluid induced leukocyte activation might play important roles in the pathophysiology of initiation of term labor or of the meconium aspiration syndrome.

Alkaline Phosphatase↗
PubMed1999

Enzyme-cytochemically detectable NADPH-diaphorase activity is present in the endoplasmic reticulum and nuclear envelope of the syncytiotrophoblast of the human placenta.

We investigated the subcellular localization of nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) activity, a histo- and cyto-chemical marker of nitric oxide synthase, in human placental trophoblast obtained from women with normal term pregnancies. Tetrazolium salt BSPT was used as the capturing agent. Precipitates of BSPT-formazan indicative of NADPH-d reaction were observed on the membranes of endoplasmic reticulum and nuclear envelope of syncytiotrophoblasts. Our results indicate these two intracytoplasmic organellae are the sites of nitric oxide generation in the syncytiotrophoblasts of normal term human placenta.

Benzothiazoles↗
PubMed1999

Hyperfunctional parathyroid glands with 99mTc-MIBI scan: semiquantitative analysis correlated with histologic findings.

UNLABELLED: The purpose of this study was to correlate the semiquantitative analysis of 99mTc-methoxyisobutyl isonitrile (MIBI) scan with histologic findings of hyperfunctional parathyroid glands. METHODS: Early and delayed cervical images of MIBI scans were reviewed in 31 patients who eventually underwent parathyroidectomies because of biochemically suspected hyperparathyroidism ([HPT], primary, n = 13; secondary, n = 18). The sensitivity of a scan for localizing the diseased glands was determined by comparing scan findings with pathologic findings, which were considered the gold standard. The average ratio of parathyroid-to-thyroid (P/T) count was compared between glands with large and small areas of whole gland, chief cell, oxyphil cell or cellular components. The mean areas of whole gland, chief cells and oxyphil cells were also compared between glands detected by MIBI scan and those that the scan missed. RESULTS: There were 99 resected lesions, including 9 parathyroid adenomas and 61 hyperplastic parathyroids. The sensitivity for localizing the diseased glands in patients with primary HPT (91%) was higher than that in patients with secondary HPT (83%). Significantly greater average P/T counts ratio on both early and delayed images was observed in the diseased glands with greater areas of whole gland, chief cells, oxyphil cells or cellular components. Fifty-nine MIBI-positive glands had significantly greater average areas of whole gland (P < 0.001) and chief cell (P = 0.002) than did 11 MIBI-negative glands. CONCLUSION: The uptake of MIBI in hyperfunctional parathyroid is dependent on gland size and the amount of cellular components, chief cells and oxyphil cells. However, the amount of oxyphil cells does not clearly affect the results of MIBI parathyroid scintigraphy, because it is small in most hyperfunctional glands.

Adenoma↗
PubMed1998

Influence of anti-androgens on the anterior horn cells of rat spinal cord: morphometric and in-situ hybridization studies.

To examine the roles of the androgens for growth and maintenance of anterior horn cells (AHCs) of the spinal cord, one of the two anti-androgen agents, flutamide or cyproterone, was injected into young rats. Morphometric analysis of the spinal cords after the injections showed that the average area occupied by an AHC was significantly smaller in the rats treated with the anti-androgens than in the controls. By contrast, neurons in the posterior horns did not show significant difference in their size. Moreover, an in-situ hybridization of choline acetyltransferase (CAT) messenger RNA revealed a significant reduction in the signal density in AHCs in the treated rats. These results show that androgens play an important role in the growth and maintenance of AHCs, and influence a wide range of protein synthesis, including that of CAT.

Androgen Antagonists↗
PubMed1998

High-dose-rate intracavitary brachytherapy in the management of cervical and vaginal intraepithelial neoplasia.

PURPOSE: To assess the effectiveness of high-dose rate intracavitary brachytherapy (HDR-ICR) in patients with grade 3 cervical intraepithelial neoplasia (CIN-3) and grade 3 vaginal intraepithelial neoplasia (VAIN-3). METHODS AND MATERIALS: This was a retrospective analysis in 20 patients with CIN-3 (n = 14) or VAIN-3 (n = 6), average age 61.9 years, managed with HDR-ICR at Kanagawa Cancer Center. Two patients with CIN-3 with microinvasive foci and 11 other patients with CIN-3 were treated with HDR-ICR for cervical lesions. Six patients with CIN-3 after hysterectomy received HDR-ICR for recurrent or residual VAIN-3 lesions. One patient received radiation therapy for both CIN-3 and VAIN-3 lesions. All these patients but one were postmenopausal. RESULTS: Seventeen patients were treated with HDR-ICR alone, and three with combined external radiation therapy. The dose was calculated at Point A located 2 cm superior to the external os and 2 cm lateral to the axis of the intrauterine tube for intact uterus. For lesions of the vaginal stump, the dose was calculated at a point 1 cm superior to the vaginal apex or 1 cm beyond vaginal mucosa. In the 14 patients treated for CIN-3 lesions, the mean total dose of HDR-ICR was 26.1 Gy (range 20-30). Six patients received HDR-ICR for VAIN-3 lesions with mean dose of 23.3 Gy (range 15-30). At follow-up (mean 90.5 months; range 13-153), 14 patients were alive and 6 had died owing to nonmalignant intercurrent disease. No patient developed recurrent disease. Rectal bleeding occurred in three patients, but this symptom subsided spontaneously. Moderate and severe vaginal reactions were noted in two patients, in whom the treatment had included the entire vagina. CONCLUSIONS: HDR-ICR can be employed as the primary management strategy for postmenopausal women with CIN-3. In intraepithelial neoplasia involving the vaginal wall after hysterectomy, HDR-ICR should be considered as an alternative to total vaginectomy.

Adult↗
PubMed1998

[Thoracoscopic surgery for diagnosis of interstitial pneumonia special reference to medicoeconomical effect].

We compared thoracoscopic surgery (TS) and open thoracotomy for the diagnosis of interstitial pneumonia. Intraoperative blood loss and duration of postoperative chest drainage were significantly less with TS than with thoracotomy. The length of postoperative hospital stay and social insurance costs with TS was significantly less than with thoracotomy. These results show that TS for the diagnosis of interstitial pneumonia is superior to open thoracotomy in terms of surgical stress and cost.

Adult↗
PubMed1998

Transarterial embolization and ablation of renal arteriovenous malformations: efficacy and damages in 30 patients with long-term followup.

PURPOSE: We evaluate the long-term efficacy and side effects of transarterial embolization and ablation for renal arteriovenous malformations. MATERIALS AND METHODS: A total of 30 patients with cirsoid arteriovenous malformations causing massive hematuria underwent 34 procedures of embolization or ablation. We confirmed the ratios of occluded arteriovenous malformation areas on angiograms and those of infarcted areas on computerized tomography. All patients were followed for 4.1 to 15.0 years (mean 8.0 +/- 2.8) after the initial procedures. RESULTS: Hematuria ceased in all patients after the initial procedures, including partial embolization or ablation of the arteriovenous malformations in 8. Massive hematuria recurred in 4 patients, who had undergone absorbable gelatin sponge (2), embolization, combined alcohol and subselective absorbable gelatin sponge embolization (1) and polyvinyl alcohol particles embolization (1). In these 4 cases total ablation of the arteriovenous malformations with alcohol was successful. In 29 patients, including aforementioned 4, no hematuria recurred after 5 years following total or partial ablation with alcohol. Large nontarget embolization with reflux of subselectively infused absorbable gelatin sponge caused a nonfunctioning kidney in 1 patient. The remaining 33 procedures caused 6.3 to 48.0% (mean 15.7 +/- 6.9%) areas of renal infarction. Polyvinyl alcohol embolization caused pulmonary embolism and renin dependent hypertension. CONCLUSIONS: Partial or total transarterial ablation of arteriovenous malformations with alcohol proved effective for long-term cessation of hematuria. However, this procedure as well as transarterial embolization has the potential risk of nontarget infarction.

Adult↗
PubMed1998

Molecular cloning and gene expression of growth hormone-releasing peptide receptor in rat tissues.

We cloned a fragment of the rat GH-releasing peptide (GHRP) receptor homologue and examined the tissue distribution of GHRP receptor mRNA in rats. Sequence analysis showed that the open reading frame is well conserved between rat and human with 96% identity in a 364-amino acid overlap. By reverse transcription-polymerase chain reaction we detected GHRP receptor mRNAs in the rat brain including the hypothalamus, anterior pituitary, and renal pelvis in twenty-eight tissues tested. Microdissection revealed that GHRP receptor mRNAs were localized predominantly in the arcuate nucleus and ventromedial hypothalamus.

Amino Acid Sequence↗
PubMed1998

Disruption of the midkine gene (Mdk) resulted in altered expression of a calcium binding protein in the hippocampus of infant mice and their abnormal behaviour.

BACKGROUND: Midkine (MK) is a growth factor implicated in the development and repair of various tissues, especially neural tissues. However, its in vivo function has not been clarified. RESULTS: Knockout mice lacking the MK gene (Mdk) showed no gross abnormalities. We closely analysed postnatal brain development in Mdk(-/-) mice using calcium binding proteins as markers to distinguish neuronal subpopulations. Intense and prolonged calretinin expression was found in the dentate gyrus granule cell layer of the hippocampus of infant Mdk(-/-) mice. In infant Mdk(+/+) mice, calretinin expression in the granule cell layer was weaker, and had disappeared by 4 weeks after birth, when calretinin expression still persisted in Mdk(-/-) mice. Furthermore, 4 weeks after birth, Mdk(-/-) mice showed a deficit in their working memory, as revealed by a Y-maze test, and had an increased anxiety, as demonstrated by the elevated plus-maze test. CONCLUSION: Midkine plays an important role in the regulation of postnatal development of the hippocampus.

Animals↗
PubMed1998

Effects of soya milk and Bifidobacterium-fermented soya milk on plasma and liver lipids, and faecal steroids in hamsters fed on a cholesterol-free or cholesterol-enriched diet.

The effects of freeze-dried soya milk (SM) and Bifidobacterium-fermented soya milk (FSM) on plasma and liver lipids, and faecal steroid excretion were estimated in hamsters fed on a cholesterol-free or cholesterol-enriched diet. Hamsters fed on the cholesterol-free diet containing 300 g FSM/kg had lower levels of plasma VLDL + LDL cholesterol than the animals fed on the control diet. SM in the diet produced a similar pattern without significant differences. In the cholesterol-enriched diet group, SM and FSM decreased the levels of plasma total cholesterol and VLDL + LDL-cholesterol. SM and FSM decreased the plasma triacylglycerol level in both the cholesterol-free and -enriched diet groups. The liver total cholesterol contents in the SM and FSM groups were lower than that in the control group, for hamsters fed on the cholesterol-free diet. The liver triacylglycerol content was not modified by SM or FSM in hamsters fed on either the cholesterol-free or -enriched diet. SM and FSM increased the total bile acid excretion and the proportion of cholesterol entering the cholic acid biosynthesis pathway in both the cholesterol-free and -enriched diet groups. SM and FSM did not affect neutral steroid excretion in the cholesterol-free or -enriched diet group. There was an inverse relationship between VLDL + LDL-cholesterol and faecal bile acid excretion in hamsters fed on the cholesterol-free (r -0.670, P < 0.01) and cholesterol-enriched (r -0.761, P < 0.001) diets respectively. These results indicated that SM had an anti-atherogenic effect, and that this effect was not diminished by prior fermentation.

Analysis of Variance↗
PubMed1998

Comparison between fractionated high dose rate irradiation and continuous low dose rate irradiation in spheroids.

Recent interest in clinical brachytherapy focuses on the possible radiobiological equivalence between fractionated high dose rate (HDR) and continuous low dose rate (LDR) irradiations. This study is designed to compare the radiobiological effects between the two in vitro using multicellular spheroids of human tumor. Both HDR and LDR irradiations were delivered by 137Cs source, the dose rates of which were as 1.18 Gy/min and 5.5 mGy/min, respectively. Fractionated HDR irradiation of various fraction sizes was applied twice a day. We found that: (1) The fractionated HDR irradiation (8 Gy/2 fr/day) was more effective radiobiologically than continuous LDR irradiation (8 Gy/day) and the ratio of radiobiological effects of these irradiations was estimated as 0.82, based on the 50% spheroid cure dose (SCD50); (2) the radiobiological effectiveness was independent of the fraction size of HDR irradiation administrated, and the repair of sublethal damage (SLD) was absent, suggesting that the sparing effect of fractionated HDR irradiations was absent in spheroids. Our findings could provide important information for the clinical usage of the fractionated HDR radiotherapy to replace continuous LDR radiotherapy.

Carcinoma, Squamous Cell↗