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Biomedical subjects

T Yasui

Publications and source records attributed to T Yasui.

At least 19 recordsLinked to original sources
PubMed2006

Association of serum undercarboxylated osteocalcin with serum estradiol in pre-, peri- and early post-menopausal women.

OBJECTIVE: We investigated changes in serum concentration of undercarboxylated osteocalcin (ucOC), which is a sensitive marker of vitamin K status, and association of ucOC concentration with estradiol concentration in pre-, peri- and early post-menopausal women. METHODS: The study population consisted of 193 pre-, peri- and post-menopausal Japanese women aged 39-66 yr. Serum ucOC concentration was measured to assess vitamin K status; serum concentrations of intact osteocalcin (OC) and bone-specific alkaline phosphatase (BAP) were measured as bone formation markers; and urine concentration of N-telopeptide was measured as a bone resorption marker. Serum estradiol and estrone concentrations were measured by a highly sensitive radioimmunoassay. Bone mineral density (BMD) was measured at the lumbar spine. RESULTS: Serum concentration of ucOC in peri-menopausal women was significantly (p=0.0005) higher than that in pre-menopausal women, while serum OC concentration in post-menopausal women for whom 1 yr had passed since menopause was significantly (p=0.0003, p=0.024, respectively) higher than the concentrations in pre-menopausal and peri-menopausal women. Serum ucOC concentration showed a significant negative correlation with estradiol concentration (r=-0.372, p<0.0001) and a significant positive correlation with serum FSH concentration (r=0.324, p<0.0001). Serum OC concentration was positively correlated with serum FSH concentration (r=0.317, p<0.001). CONCLUSIONS: The results showed that the change in ucOC concentration during the menopausal transition is different from that in OC concentration. In addition, serum ucOC concentration is closely associated not only with FSH concentration but also estradiol concentration.

Adult↗
PubMed2005

Recurrent vesical calculi, hypercalciuria, and biochemical evidence of increased bone resorption in an adult male with paraplegia due to spinal cord injury: is there a role for intermittent oral disodium etidronate therapy for prevention of calcium phosphate bladder stones?

STUDY DESIGN: Clinical case report with comments by colleagues from Sweden, Poland, Spain, Brazil, Japan, Belgium and Switzerland. OBJECTIVES: To discuss the role of disodium etidronate therapy for prevention of calcium phosphate vesical calculi in persons with spinal cord injury, who have hypercalciuria and biochemical evidence of increased bone resorption. SETTING: Regional Spinal Injuries Centre, Southport, UK. METHODS: A 21-year-old male sustained paraplegia (T-10; ASIA scale: A) in a road traffic accident in June 2001. He had an indwelling urethral catheter until the end of August 2001, when he started self-catheterisation. He developed bladder stones and electrohydraulic lithotripsy (EHL) was performed in May 2002. All stone fragments were removed. Recurrence of vesical calculi was noted in October 2002. These stones were fragmented by lithoclast lithotripsy in two sessions, in December 2002 and February 2003; all stone fragments were removed at the end of the second session. This patient reverted to indwelling catheter drainage when vesical calculi recurred. In September 2003, X-ray of the abdomen showed recurrence of vesical calculi. By February 2004, the stones had increased in size and number. EHL of vesical calculi was again performed in April 2004. Complete clearance was achieved. RESULTS: A 24-h urinalysis detected hypercalciuria--18.7 mmol/day (reference range: 2.5-7.5). Biochemical analysis of vesical calculus revealed calcium phosphate (85%) and magnesium ammonium phosphate (15%). Plasma C-terminal telopeptide (CTX) was increased - 1.06 ng/ml (reference range: 0.1-0.5 ng/ml). Free deoxypyridinoline/creatinine ratio (fDPD/Cr) in urine was also increased - 20.2 (reference range: 2.3-5.4). In April 2004, this patient was prescribed disodium etidronate 400 mg day. Nearly 3 months after commencing therapy with etidronate, plasma CTX decreased to 0.87 ng/ml. fDPD/Cr in urine also decreased to 12.4. After 4 months of etidronate therapy, 24-h urinary calcium excretion had decreased to 6.1 mmol/day. CONCLUSION: Etidronate (400 mg daily) is a very effective inhibitor of calcium phosphate crystallisation. Etidronate decreased urinary excretion of calcium, an important factor in prevention of calcium phosphate bladder stones. Etidronate therapy is not a substitute for other well-established methods for prevention of vesical calculi in spinal cord injury patients, for example, large fluid intake, avoiding long-term catheter drainage. Intermittent therapy with etidronate may be considered in selected patients, in whom hypercalciuria persists after instituting nonpharmacological therapy for an adequate period, for example, early mobilisation, weight-bearing exercises, and functional electrical stimulation. However, possible side effects of etidronate, and the fact that etidronate is not licensed in United Kingdom for prevention of urolithiasis, should be borne in mind.

Adult↗
PubMed2005

Effect of hormone replacement therapy on the production of bone-resorbing cytokines by peripheral blood cells in postmenopausal women.

We studied the effects of hormone replacement therapy (HRT) with estrogen on postmenopausal changes in the production of bone-resorbing cytokines interleukin 1 beta (IL-1beta) and tumor necrosis factor alpha (TNFalpha). Both cytokines were measured in the supernatants of lipopolysaccharide (LPS)-stimulated whole-blood cells from 72 untreated and 44 HRT-treated women by ELISA. The levels of IL-1beta were significantly higher in women in their 40s and 50s and in postmenopausal women than in women in their teens, 20s and 30s, while the levels of TNFalpha did not show any changes related to age. Both levels in HRT-treated women were significantly lower than those in untreated women at almost every postmenopausal stage. In a prospective study, HRT induced significant declines in both levels. These results show that estrogen decreases the accelerated production of IL-1beta and reduces the production of TNFalpha in postmenopausal women at each postmenopausal stage, even in late-postmenopausal women.

Adult↗
PubMed2005

Regulatory factors on parathyroid hormone-related peptide production by primary culture of lactating rat mammary gland.

Parathyroid hormone-related protein (PTHrP) is a major cause of humoral hypercalcemia of malignancy, but has also been widely found in fetal and adult non-neoplastic tissues. Lactating mammary gland has been shown to produce large amounts of PTHrP, and high levels of PTHrP have been measured in milk. We have examined the influences of several substances on the secretion of two different forms of PTHrP by primary cultures of mammary cells isolated from lactating rats to examine the regulatory mechanisms of PTHrP production by mammary cells. Primary cultures of mammary cells seeded at a density of 10(5) cells per 35 mm culture dish were grown on collagen gels. First, after cells were left 24 hours for attachment and incubated in 2 % FCS containing medium with for 12 hours, PTHrP (1 - 87) secretions were measured in conditioned medium with hormone supplementation for 1, 24 and 48 hours. Progesterone (10(-7) - 10(-5) mol/l) significantly suppressed PTHrP (1 - 87) secretion in a dose-dependent manner (p < 0.01), while 17beta-estradiol had no influence on PTHrP (1 - 87) secretion. Prolactin, a known stimulator of PTHrP expression in vivo, had no effect in this in vitro model. Second, PTHrP (1 - 34) secretion levels from confluent lactating mammary cells for 24 hours were evaluated. The same results were obtained in the case of PTHrP (1 - 87) secretion from non-confluent cells. Furthermore, dexamethasone (10(-6) mol/l) significantly suppressed PTHrP (1 - 34) secretion (p < 0.01). These results suggest that PTHrP production from the lactating mammary gland is suppressed by progesterone as well as dexamethasone. Progesterone dramatically falls after delivery, thus possibly accelerating PTHrP production by lactating mammary glands and resulting in considerable amounts of PTHrP secreted into the milk.

Animals↗
PubMed2005

Development of an ankle-foot orthosis with an oil damper.

The purpose of the present study was to develop an ankle-foot orthosis (AFO) that satisfies the requirements for an AFO for patients with hemiplegia as determined in a previous study. An oil damper has been introduced as an assistive device. The oil damper provides a resistive moment to plantar flexion of the ankle joint during initial stance on the paretic side. This function improves the insufficient eccentric contraction of the dorsiflexors. The magnitude of the resistive moment generated by this newly developed AFO can be changed easily to adjust its properties in accordance with the requirements of each patient. The mechanical properties of the AFO were measured, and the results showed that the AFO generated a sufficient resistive moment. Hemiplegic gaits with various types of AFOs were assessed, and it was found that the properties of the AFO affected the movements of the ankle, the knee, and the hip joints. The effects of the resistive moment on the alignment of the shank to the floor during initial stance are also discussed. Based on the results of this study, it is concluded that adjustability will be an essential feature for future AFOs.

Ankle Joint↗
PubMed2005

Relationship between temporary inhibition and structure of disulfide-linkage analogs of marinostatin, a natural ester-linked protein protease inhibitor.

A 12-residue marinostatin [MST(1-12): (1)FATMRYPSDSDE(12)] which contains two ester linkages of Thr(3)-Asp(9) and Ser(8)-Asp(11) strongly inhibits subtilisin. In order to study the relationship between the inhibitory activity, structure, and stability of MST, MST analogs were prepared by changing ester linkages to a disulfide linkages. The analogs without the disulfide linkage between 3 and 9 positions lost their inhibitory activity. The K(i) value of 1SS(C(3)-C(9)) ((1)FACMRYPSCSDE(12)), which has a single disulfide linkage of Cys(3)-Cys(9) was comparable with those of MST(1-12) and MST-2SS ((1)FACMRYPCCSCE(12)), a doubly linked analog of Cys(3)-Cys(9) and Cys(8)-Cys(11). However, 1SS(C(3)-C(9)) and MST-2SS showed temporary inhibition, but not MST(1-12): These analogs were inactivated after incubation with subtilisin for 30 min, and were specifically hydrolyzed at the reactive site. (1)H NMR study showed that 1SS(C(3)-C(9)) has two conformations, which contain a cis- (70%) or trans- (30%) Pro residue, while MST-2SS as well as MST(1-12) takes a single conformation containing only a cis-Pro residue. Hydrogen-deuterium exchange rate of the Arg(5) (P1') NH proton of the MST analogs was about 100 times faster than that of MST(1-12). These results indicate that the linkage between the positions 8 and 11 plays a role for fixing the cis-conformation of the Pro(7) residue, and that the linkage between 3 and 9 is indispensable for the inhibition, but not enough for stable protease-inhibitor complex.

ATP-Binding Cassette Transporters↗
PubMed2005

Ultracytochemical demonstration of glycoproteins in the eccrine glands of the digital pads of the North American raccoon (Procyon lotor).

In the eccrine glands of the digital pads of the North American raccoon (Procyon lotor), ultrastructural localization of glycoproteins with various saccharide residues was studied using preferably lectin cytochemical methods. Secretory granules observed in the dark cells exhibited glycoproteins with different terminal sugars (alpha-D-mannose, beta-D-galactose, beta-N-acetyl-D-glucosamine and sialic acid). The cytoplasm of the clear cells contained numerous glycogen particles. Several sugars were also detectable in the surface coat of the plasma membrane of the secretory cells. The results obtained could be helpful in understanding secretion production and cell related secretion functions of the eccrine glands of the raccoon digital foot pads.

Animals↗
PubMed2005

Possible link between glycolysis and apoptosis induced by sodium fluoride.

Fluoride has been used to prevent caries in the dentition, but the possible underlying mechanisms of cytotoxicity induction by this compound are still unclear. Since fluoride is known as an inhibitor of glycolytic enzymes, we investigated the possible connection between NaF-induced apoptosis and glycolysis in human promyelocytic leukemia HL-60 cells. NaF-induced apoptotic cell death is characterized by caspase activation, internucleosomal DNA fragmentation, loss of mitochondrial membrane potential, and production of apoptotic bodies. Higher activation of caspases-3 and -9, as compared with that of caspase-8, suggested the involvement of an extrinsic pathway. Utilization of glucose was nearly halted by NaF, whereas that of glutamine was rather enhanced. NaF enhanced the expression of Bad protein, but not that of Bcl-2 and Bax proteins, and reduced HIF-1alpha mRNA expression. Analysis of these data suggests a possible link between glycolysis and apoptosis.

Apoptosis↗
PubMed2004

Pleasant feeling from watching a comical video enhances free radical-scavenging capacity in human whole saliva.

OBJECTIVE: Free radicals have been implicated in aging, mutagenesis, inflammation and other pathological conditions. We conducted a study to clarify the relation between a pleasant feeling as a psychological eustress and free radical-scavenging capacity (FRSC) in saliva. METHODS: Saliva was collected from 27 healthy volunteers. FRSC before, during and after watching a cheerful comical video for 30 min was measured by using 1,1-diphenyl-2-picrylhydrazyl (DPPH). RESULTS: The median values of FRSC (micromol/ml) before, at 10 and 20 min during and after watching the video were 54.5, 66.8, 66.6 and 69.4, respectively. The FRSC values obtained after watching the video were significantly higher than those before watching it (P<.001). When the FRSC before watching was taken as 1, the value for the group that felt "Very good," "Good" or "Ordinary+Dull" while watching the video for 30 min was 1.38, 1.20 or 0.98, respectively (P<.01). CONCLUSION: Watching a comical video enhanced the FRSC in saliva; in addition, a pleasant feeling boosted it even more.

Adult↗
PubMed2004

Effects of a twin strain of saccharomyces cerevisiae live cells on mixed ruminal microorganism fermentation in vitro.

This experiment was designed to investigate the effects of different concentrations (0, 0.33, 0.66, 0.99, and 1.32 g/L) of a twin-strain of Saccharomyces cerevisiae live cells on in vitro mixed ruminal microorganism fermentation of corn starch, soluble potato starch, and sudangrass hay (60.5%, DM basis) plus concentrate mixture (39.5%, DM basis). Ruminal fluid was collected from two dairy cows, mixed with phosphate buffer (1:2), and incubated (30 mL) anaerobically at 38 degrees C for 6 and 24 h with or without yeast supplement, using 200 mg (DM basis) of each substrate. Medium pH, ammonia-N, and numbers of protozoa were unaffected (P = 0.38) by yeast cells in all substrates. Molar proportion of acetate was unchanged (P = 0.56) with cornstarch and soluble potato starch, but increased quadratically (P = 0.02) with hay plus concentrate by treatment. Addition of yeast cells caused a linear increase of total VFA (P = 0.008) in all substrates. Excluding the soluble potato starch, supplementation of S. cerevisiae resulted in a quadratic increase of propionate (P = 0.01), with a quadratic decrease (P = 0.04) of acetate:propionate. When soluble potato starch was used as a substrate, a linear increase (P = 0.006) of the molar proportion of propionate and a quadratic decrease (P = 0.007) in acetate:propionate was observed by treatment. Molar proportion of butyrate was unchanged (P = 0.35) with cornstarch and soluble potato starch, whereas it decreased linearly (P = 0.007) with hay plus concentrate by yeast cell supplementation. When cornstarch and soluble potato starch were used as a substrate, minor VFA were decreased (P = 0.05) by treatment. Accumulation of lactate was linearly decreased by treatment (P = 0.007) in all substrates. During incubation with hay plus concentrate, IVDMD was linearly increased (P = 0.006), whereas production of methane (linear; P = 0.02) and accumulation of hydrogen was decreased (quadratic; P = 0.005) by treatment after 24 h. These results showed that a twin strain of S. cerevisiae live cells stimulated in vitro mixed ruminal microorganism fermentation with decreased lactate, and a small decrease of methane and hydrogen with hay plus concentrate.

Ammonia↗
PubMed2002

Simultaneous dissection of intra- and extracranial vertebral artery. Report of two cases and review of literature.

Two patients who developed subarachnoid haemorrhage are presented. The first patient was a 41-year-old woman whose angiograms showed right extracranial vertebral artery (VA) dissection starting at the C2 level extending to the intracranial VA near the VA union. Proximal occlusion of the right VA by the endovascular approach was performed. The second patient was a 57-year-old man whose angiograms showed the left intracranial VA dissection distal to the posterior inferior cerebellar artery and an extracranial aneurysmal dilatation of the left VA at the C1 level and extracranial VA dissection in the V3 portion of the right VA. Left intracranial VA dissection was surgically trapped, and the remaining lesions were conservatively treated. Simultaneous dissection of the intracranial and extracranial portions of the VA is rare. Such lesions usually cause brain ischaemia, but may cause intracranial subarachnoid haemorrhage.

Adult↗
PubMed2002

Transfemoral, transvenous embolisation of dural arteriovenous fistula involving the isolated transverse-sigmoid sinus from the contralateral side.

BACKGROUND: A dural arteriovenous fistula (AVF) involving the transverse-sigmoid (T-S) sinus which is occluded at its proximal and distal ends i.e., an isolated sinus, runs the risk of haemorrhaging or causing serious neurological deficits as a result of its retrograde leptomeningeal venous drainage. While lesions of this type have not been considered to be treatable by percutaneous, transvenous embolisation, this paper challenges this view. CASE PRESENTATION: Two middle-aged men with dural AVFs involving the isolated left T-S sinus presented with motor aphasia due to focal brain edema or haemorrhage. Under local anaesthesia, transfemoral, transvenous embolisation was performed with a microcatheter that was passed through the occluded proximal transverse sinus from the right (contralateral) side. The isolated sinus was then occluded with platinum coils. This embolisation resulted in angiographic and clinical cure of dural AVFs in both patients. INTERPRETATION: Transfemoral, transvenous embolisation is a therapeutic alternative for the treatment of dural AVFs involving the isolated T-S sinus. Embolisation obviates the need for craniotomy and general anaesthesia, which are required for the established modes of treatment, i.e., direct surgery or direct percutaneous sinus packing.

Angiography, Digital Subtraction↗
PubMed2002

Serum osteoprotegerin/osteoclastogenesis-inhibitory factor during pregnancy and lactation and the relationship with calcium-regulating hormones and bone turnover markers.

Pregnancy and lactation induce dynamic changes in maternal bone and calcium metabolism. A novel cytokine termed osteoprotegerin (OPG)/osteoclastogenesis-inhibitory factor (OCIF) was recently isolated; this cytokine inhibits osteoclast maturation. To define the effects of pregnancy and lactation on circulating OPG/OCIF in mothers, we studied the changes in the levels of OPG/ OCIF as well as those of calcium-regulating hormones and biochemical markers of bone turnover in the maternal circulation during pregnancy (at 8-11 weeks, at 22-30 weeks, at 35-36 weeks and immediately before delivery) and lactation (at 4 days and at 1 month postpartum). Serum intact parathyroid hormone levels did not change and were almost within the normal range in this period. In contrast, serum 1,25-dihydroxyvitamin D levels increased with gestational age and were above the normal range during pregnancy. After delivery, they fell rapidly and significantly (P<0.01) to the normal range. The levels of serum bone-specific alkaline phosphatase, one of the markers of bone formation, increased with gestational age. After delivery, these levels were further increased at 1 month postpartum. The levels at 1 month postpartum were significantly higher than those at 8-11 and 22-30 weeks of pregnancy (P<0.01 and P<0.05 respectively). The levels of serum C-terminal telopeptides of type I collagen, one of the markers of bone resorption, did not change during pregnancy. After delivery, they rapidly and significantly (P<0.01) rose at 4 days postpartum, and had then fallen by 1 month postpartum. Circulating OPG/OCIF levels gradually increased with gestational age and significantly (P<0.01) increased immediately before delivery to 1.40+/-0.53 ng/ml (means+/-S.D.) compared with those in the non-pregnant, non-lactating controls (0.58+/-0.11 ng/ml). After delivery, they fell rapidly to 0.87+/-0.27 ng/ml at 4 days postpartum and had fallen further by 1 month postpartum. These results suggest that the fall in OPG/OCIF levels may be partially connected with the marked acceleration of bone resorption after delivery.

Adult↗
PubMed2001

Enhanced invasiveness of pancreatic adenocarcinoma cells stably transfected with cationic trypsinogen cDNA.

Various studies have described increased expression of cationic trypsinogen in malignant tumor cells. To explore the role of secreted cationic trypsinogen in invasion by cancer cells, we introduced cationic trypsinogen cDNA into Panc-1, a pancreatic adenocarcinoma-derived cell line that lacks expression of endogeneous trypsinogen. Four independent clones (designated Panc-1-Try-7, -9, -11 and -24) stably expressing cationic trypsinogen mRNA were isolated and processed for further study. In a zymographic analysis, gelatinolytic activity for cationic trypsinogen was detectable in serum-free conditioned media obtained from all 4 transfectants but not in media from mock-transfected or parental Panc-1 cells. A Matrigel invasion assay revealed that all trypsinogen-expressing transfectants acquired significantly greater invasive ability than that shown by mock-transfected and parental Panc-1 cells. In addition, enhanced invasiveness of the transfectants was suppressed by FUT-175, a serine protease inhibitor, to the level seen in parental cells. These results provide direct evidence that cationic trypsinogen can increase the invasive ability of carcinoma cells.

Adenocarcinoma↗
PubMed2001

Orexin-A suppresses the pulsatile secretion of luteinizing hormone via beta-endorphin.

Orexins, the novel hypothalamic neuropeptides that stimulate feeding behavior, have been shown to suppress the pulsatile secretion of LH in ovariectomized rats. However, the mechanism of this action is still not clear. We examined the effect of naloxone, a specific opioid antagonist, on the suppression of the pulsatile secretion of LH by orexins to determine whether beta-endorphin is involved in this suppressive effect. We administered orexins intracerebroventricularly and injected naloxone intravenously in ovariectomized rats, and we measured the serum LH concentration to analyze the pulsatile secretion. Administration of orexin-A significantly reduced the mean LH concentration and the pulse frequency, but coadministration of naloxone significantly restored the mean LH concentration and the pulse frequency. Administration of orexin-B also significantly reduced the mean LH concentration and the pulse frequency, and coadministration of naloxone did not restore them. These results indicate that orexin-A, but not orexin-B, suppresses GnRH secretion via beta-endorphin.

Animals↗
PubMed2001

B cell subsets in postmenopausal women and the effect of hormone replacement therapy.

OBJECTIVES: In elderly subjects the capacity for antibody production is depressed. This immunosenescence state of humoral immunity is associated with the occurrence of autoimmune disorders involving CD5+ B (B-1) cells. Since estrogen is capable of stimulating the production of autoantibodies, this sex steroid hormone may be a contributing cause of the higher incidence of autoimmune diseases in women. In the present study, B cell subsets in women during the postmenopausal period was determined. The effect of hormone replacement therapy (HRT) on B cell subsets was examined to establish whether the administration of gonadal hormones influence humoral immunity in postmenopausal women. METHODS: Forty six untreated pre- and postmenopausal women and 39 women on HRT were studied. The proportion of B-1 (CD5+) and conventional CD5- B (B-2) lymphocytes was determined by two-color flow cytometry. Serum autoantibodies to a nuclear antigen and to interleukin (IL)-1alpha were measured by immunofluorescence and by radioimmunoassay, respectively. Thirteen women were examined prospectively before and during HRT. RESULTS: In late postmenopausal women (> or = 30 years postmenopausal period), the proportion of B-2 cells was significantly reduced (p<0.01) compared to those of premenopausal and perimenopausal women. HRT induced a significant (p<0.01) increase in the percentage of B-2 cells, while that of B-1 cells remained unchanged. HRT did not affect autoantibody production. CONCLUSION: HRT may retard the progress of immunosenescence by increasing the production of B-2 cells. Moreover, HRT appears not to increase the risk of autoimmune diseases developing in postmenopausal women.

Adult↗
PubMed2001

Leptomeningeal contrast enhancement in moyamoya: its potential role in postoperative assessment of circulation through the bypass.

Leptomeningeal contrast enhancement (LMCE) is one of the MRI features of moyamoya. Its clinical significance, however, is not elucidated. Our purpose was to characterise LMCE on MRI and to evaluate its role in the assessment of circulation through a surgically established bypass in moyamoya. We studied 16 patients with idiopathic moyamoya (seven males, nine females, includingt four children, aged 7 to 54 years, mean 24 years) who underwent T1-weighted MRI before and after intravenous contrast medium. The presence of LMCE, its intensity and anatomical distribution, catheter angiographic findings, and relation of LMCE to the bypass surgery were assessed. More LMCE was seen in the cerebrum in most patients with moyamoya than in normal controls. LMCE in the brain stem and cerebellum was minimal, similar to that seen in the controls. LMCE was less prominent following surgery than before operation or in patients who did not undergo surgery. In three patients examined both before and after operation LMCE became less prominent following bypass surgery. As LMCE becomes less prominent after "effective" bypass surgery, this may be used for evaluation of effectiveness of surgery in moyamoya.

Adult↗