Biomedical subjects

H Abe

Publications and source records attributed to H Abe.

At least 73 records · Page 4Linked to original sources

PubMed2001

A vitamin D analog ameliorates glomerular injury on rat glomerulonephritis.

OCT (22-oxa-calcitriol), a vitamin D analog, has been reported to show strong inhibitory effects on mesangial cell proliferation in vitro. In the present study, we report a study of the effect of OCT on anti-thy-1 glomerulonephritis. Both OCT and 1,25(OH)(2)D(3) significantly inhibited mesangial cell proliferation, the degree of glomerulosclerosis, and albuminuria at day 8 compared to the disease control group. The OCT-treated group showed normal calcium levels but the 1,25(OH)(2)D(3)-treated group showed higher levels. The disease control group showed a marked increase of type I and type IV collagens, and alpha-smooth muscle actin (alpha-SMA) compared to the normal group. The treatment of OCT or 1,25(OH)(2)D(3) significantly reduced the expression of these proteins. The mRNA of the glomeruli of anti-thy-1 model expressed significantly higher levels of type I and type IV collagens, and alpha-SMA at day 8 compared to normal rats. Treatment with OCT or 1,25(OH)(2)D(3) inhibited the mRNA expressions of type I and type IV collagens, as well as that of alpha-SMA. These data demonstrate that OCT inhibits mesangial cell proliferation and extracellular matrix expansion with a low calcemic activity. Disease control rats showed significantly increased levels of transforming growth factor-beta1 protein in the glomeruli, but treatment with OCT or 1,25(OH)(2)D(3) markedly reduced this expression. The levels of mRNA in glomeruli were also consistent with these protein levels. Therefore, the suppressive effect of OCT may be mediated by inhibition of transforming growth factor-beta1. The present results suggest that OCT has potential for use in therapeutic strategy for the treatment of glomerulonephritis without inducing hypercalcemia.

Actins↗

PubMed2001

Treatment outcome of single or hypofractionated single-isocentric stereotactic irradiation (STI) using a linear accelerator for intracranial arteriovenous malformation.

BACKGROUND AND PURPOSE: We investigated the use of hypofractionated stereotactic radiotherapy (HFSR) to reduce adverse radiation effects in comparison to single-fraction stereotactic radiosurgery (SRS) for intracranial arteriovenous malformations (AVMs). MATERIALS AND METHODS: This study includes 53 intracranial AVMs treated between 1991-1998. HFSR was selected for 26 AVMs with a maximum diameter > or 2.5 cm or at eloquent area. Twenty-seven patients were treated with SRS (18 AVMs < 2.5 cm at non-eloquent area, nine patients who were unfit for prolonged ring-wearing). The most frequent minimum dose (Dmin) was 20 Gy for SRS and 28 Gy for HFSR in four fractions. The mean follow-up duration was 34.6 months for SRS and 35.4 months for HFSR. RESULTS: As a whole, the 3 and 5-year actuarial obliteration rates were 64 and 92%. Age <20 years old (P=0.02) and a maximum diameter <2 cm were favorable factors (P=0.05). A difference in the distribution of patients was observed in size (> or =2.5 cm or not) (P<0.001) and location (eloquent or not) (P<0.001) between SRS and HFSR due to the treatment selection. However, no significant differences were observed in the actuarial rates of obliteration and transient increased signals with T2-weighted MR images between SRS and HFSR. Radiation necrosis occurred in two patients treated with SRS and in none with HFSR. Intracranial hemorrhage after treatment happened in two treated with SRS and three with HFSR. CONCLUSIONS: HFSR appears to be at least as effective as SRS in achieving complete obliteration of intracranial AVM, although its definitive role remains to be investigated.

Adolescent↗

PubMed2001

Analysis of adsorption function of polyhydroxybutyrate depolymerase from Alcaligenes faecalis T1 by using a quartz crystal microbalance.

Enzymatic adsorption and degradation of three types of aliphatic polyester films and two types of polyolefin films by the extracellular PHB depolymerase from Alcaligenes faecalis T1 have been studied by using a quartz crystal microbalance (QCM) technique. Hydrolysis of poly[(R)-3-hydroxybutyrate] was quantitatively followed by the QCM technique. Adsorption of the enzymes to films was also quantitatively detected by the QCM. Kinetic study on enzymatic adsorption suggests that the PHB depolymerase binds to the substrates not only by hydrophobic interaction but also by specific interaction between the ester bonds of polyesters and the binding domain of the enzyme. The results show that the QCM technique is a sensitive tool to study enzymatic degradation kinetics of biodegradable polyesters.

Adsorption↗

PubMed2001

Crystallization, melting, and enzymatic degradation of biodegradable poly(butylene succinate-co-14 mol % ethylene succinate) copolyester.

The crystal structure and growth kinetics of melt-crystallized poly(butylene succinate-co-14 mol % ethylene succinate) [P(BS-co-14 mol % ES)] copolyester have been investigated at a wide crystallization temperature range of 30 to 90 degrees C. By means of wide-angle X-ray diffraction (WAXD), the copolyester composed of BS and ES units has been identified to have the same crystal structure with that of poly(butylene succinate) (PBS) homopolymer, suggesting that only PBS sequences crystallize while that the ES units are in an amorphous form. On the basis of secondary nucleation theory, two regimes of II and III have been observed and their transition temperature is around 80 degrees C. The spherulitic morphologies of P(BS-co-14 mol % ES) copolyester developed from banded spherulites to the normal ones without banding extinction patterns as the crystallization temperature increased. The melting behavior of P(BS-co-14 mol % ES) copolyester under different conditions has been studied by differential scanning calorimetry (DSC). Four melting peaks and one exothermal peak on the melting curves were observed during heating process, and their origination is discussed. The enzymatic degradation was carried out on the melt-crystallized P(BS-co-14 mol % ES) thin film by an extracellar PHB depolymerase from Pseudomonas stutzeri and the morphologies of lamellar crystals before and after degradation have been examined by atomic force microscopy (AFM). The results have indicated that enzymatically degradable ES units exist on the surface of lamellar crystals and are hydrolyzed by the enzyme, while that the crystalline cores composed of PBS chains are not degraded.

Absorbable Implants↗

PubMed2001

Solid-state microstructures, thermal properties, and crystallization of biodegradable poly(butylene succinate) (PBS) and its copolyesters.

Studies of solid-state structures under different crystallization conditions, melting behavior, and crystal growth kinetics are reported for biodegradable aliphatic poly(butylene succinate) (PBS) and its random copolyesters of poly(butylene succinate-co-14 mol %ethylene succinate) [P(BS-co-14 mol %ES)] and poly(butylene succinate-co-15 mol %hexamethylene succinate) [P(BS-co-15 mol %HS)]. The crystal structures of two copolyesters determined by wide-angle X-ray diffraction (WAXD) are the same as that of the PBS homopolymer, suggesting that the second comonomers ES or HS units are excluded from the crystalline core and are in an amorphous state. The further investigations on the crystalline and amorphous phase structures and sizes by small-angle X-ray scattering (SAXS) method have provided quantitative evidence that the existence of second comonomers increases the amorphous thickness of copolyesters but that the influences of comonomers on the lamellar crystal structure and size of copolyesters are complicated. The origin of the complexity and its influences on the equilibrium melting temperature T(m)(0) of copolyester are discussed in the present paper. Gibbs-Thomson and Hoffman-Weeks equations were applied for the determination of T(m)(0) of PBS, P(BS-co-14 mol %ES), and P(BS-co-15 mol %HS)-three samples. Two equations gave different T(m)(0) values for each sample. On the basis of the Gibbs-Thomson equation, the P(BS-co-15 mol %HS) copolyester has the same T(m)(0) value as that of the PBS homopolymer, while the P(BS-co-14 mol %ES) copolyester has a lower one. This is due to the different influences of the second comonomers on the crystalline phase structure indicated by SAXS results, and the Gibbs-Thomson equation has been suggested to be more reliable. The crystal growth kinetics of the three samples was analyzed by using the secondary nucleation theory, and the influences of various parameters on the regime transition and nucleation constant were studied. Meanwhile some interrelations between regime transition temperature and melting behavior were found for the three samples.

Biodegradation, Environmental↗

PubMed2001

In situ observation of crystal growth for poly[(S)-lactide] by temperature-controlled atomic force microscopy.

The crystallization behavior and crystalline morphologies of poly[(S)-lactide] (P[(S)-LA]) in thin films crystallized isothermally at over 160 degrees C were characterized by transmission electron microscopy and atomic force microscopy (AFM). The dendritic crystal and hexagonal crystal were formed in thin film with thicknesses below 30 nm or over 50 nm, respectively. The crystal structures of dendritic and hexagonal crystals were identical, suggesting that the crystalline morphology of P[(S)-LA] is strongly dependent upon the film thickness. In situ observation of the crystal growth in the P[(S)-LA] thin film at 165 degrees C from the melt was carried out by using temperature-controlled AFM equipped with a heating stage. The initial stage of crystallization and development of lamellae were successfully observed during isothermal crystallization at 165 degrees C. The first forming crystal showed the edge-on orientation, and grew to S-shaped edge-on lamellae. Dendritic flat-on crystals were developed from the S-shaped edge-on lamellae. The growth rates of flat-on and edge-on lamellae were almost identical.

Biocompatible Materials↗

PubMed2001

Morphological and kinetic analyses of regime transition for poly[(S)-lactide] crystal growth.

Regime transitions of poly[(S)-lactide] (PLA) crystal growth from the melt were investigated by studying the morphological changes and carrying out kinetic analysis using microscopic techniques. PLA thin films with an average layer thickness of 100 nm were isothermally crystallized at a given crystallization temperature after melting at 220 degrees C. Following isothermal crystallization at a temperature below 145 degrees C, uniform two-dimensional spherulites having stacked flat-on lamellar texture were developed throughout the PLA thin films. On the basis of electron diffraction analysis for two-dimensional spherulites of PLA, it was found that the average growth direction of an individual lamellar crystal was parallel to the crystallographic b axis. At temperatures above 150 degrees C, hexagonal lamellar crystals were formed from the melt. Electron diffractograms of these lamellae showed that the crystal had orthogonal packing of PLA molecules and a truncated-lozenge-shaped growth behavior. The growth surfaces of the hexagonal crystal were parallel to either the crystallographic (110) or the (100) plane. The PLA crystal growth rate along the b axis direction was evaluated at various crystallization temperatures of the thin films. Kinetic analysis of crystal growth in the PLA thin film demonstrated that the regime transitions of PLA crystal growth, from regime III to regime II and from regime II to regime I, occur at around 120 and 147 degrees C, respectively. The transition from regime II to regime I induced morphological changes in the crystalline aggregates whereby spherulitic aggregates transformed into hexagonal lamellar stacking. As for the transition between regimes II and III, no obvious morphological change in the spherulitic crystal aggregates was observed.

Biocompatible Materials↗

PubMed2001

Purification and characterization of poly(aspartic acid) hydrolase from Sphingomonas sp. KT-1.

Poly(aspartic acid) (PAA) hydrolase was purified from Sphingomonas sp. KT-1 (JCM10459). The purified hydrolase degraded thermally synthesized PAA to oligomers. The molecular mass of PAA hydrolase was 30 kDa and the isoelectric point was 8.9. The optimum values of pH and temperature for PAA degradation were 10.0 and 40 degrees C, respectively. The investigation of the effect of inhibitors for the PAA-degrading activities has revealed that the PAA hydrolase is a serine-type hydrolase. The structural analysis of PAA-degraded products using (1)H and (13)C nuclear magnetic resonances has indicated that the purified enzyme hydrolyzes selectively the beta-amide linkage connecting with beta-aspartic acid units in PAA.

Hydrogen-Ion Concentration↗

PubMed2001

Behavioural rhythm splitting in the CS mouse is related to clock gene expression outside the suprachiasmatic nucleus.

CS mice exhibit a spontaneous splitting in the circadian rhythm of locomotor activity under constant darkness, suggesting that they contain two weakly coupled oscillators in the circadian clock system regulating locomotor activity rhythm. In order to clarify whether the two oscillators are located in the suprachiasmatic nucleus (SCN), a site of the master circadian pacemaker in mammals, circadian rhythms in mRNA of mouse Period genes (mPer1, mPer2 and mPer3) in the SCN and cerebral cortex were examined during rhythm splitting by in situ hybridization. In the SCN, mPer1 and mPer2 showed a circadian rhythm with a single peak in both split and unsplit mice. The rhythms of mPer1 and mPer2 were slightly phase delayed during rhythm splitting in reference to the activity onset, but the phase relationship between the two rhythms was not changed. In the cerebral cortex, the expression of mPer1 and mPer2 underwent the bimodal fluctuation with peaks temporally corresponding to split activity components. The unsplit mice showed the circadian rhythms with a single peak. There was no difference in the mPer3 rhythms in either the SCN or the cerebral cortex between the split and unsplit mice. These results indicate that the circadian oscillations of mPer1, mPer2 and mPer3 in the SCN are not related to the rhythm splitting of CS mice. The split rhythms of the CS mice are suggested to be caused by uncoupling of oscillators located outside the SCN from the SCN circadian pacemaker.

Animals↗

PubMed2001

Circadian activity rhythm in methamphetamine-treated Clock mutant mice.

It is well established that the Clock gene is essential for expressing circadian activity rhythms in mammals under constant darkness. The Clock gene product is a positive component of a molecular feedback loop which is assumed to generate the circadian rhythm. On the other hand, chronic treatment of methamphetamine (MAP) induces locomotor activity rhythm in a circadian domain, which is independent of the suprachiasmatic nucleus (SCN) and is driven by a pacemaker outside the SCN. However, it is not known whether the pacemaker outside the SCN possesses a similar molecular mechanism to that in the SCN. Here we show that MAP restores locomotor activity rhythm in arrhythmic homozygous Clock mutant (Clock/Clock) mice under constant darkness. This result indicates that the Clock mutation does not affect the MAP-induced locomotor rhythm.

Animals↗

PubMed2001

Bone metabolism and body composition in Japanese patients with active acromegaly.

OBJECTIVE: Skeletal involvement is a common clinical feature in acromegalic patients. Although several recent reports are available concerning bone mineral density (BMD) in acromegaly, the controversy still exists as to whether BMD of acromegalic patients is increased or not. The present study was performed to examine biochemical bone metabolic indices and BMD as well as body composition in 26 Japanese patients with active acromegaly and 26 control subjects matched for age, sex, race and height in a cross-sectional study. MEASUREMENTS: BMD of the lumbar spine and femoral neck, as well as body composition, was measured by dual-energy X-ray absorptiometry. Mid-radial BMD was measured by single-photon absorptiometry. We also determined serum levels of IGF-I, IGFBP-3 and osteocalcin (OC) as well as urinary levels of deoxy-pyridinoline (D-Pyr) and CrossLaps. RESULTS: Percent lean body mass was increased and percent fat mass was decreased in the acromegalic patients compared to control subjects. Serum levels of OC, as well as urinary levels of D-Pyr and CrossLaps, were significantly higher in acromegalic patients compared to control subjects (9.8 +/- 1.2 vs. 5.7 +/- 0.77 for OC; 11.8 +/- 1.66 vs. 5.0 +/- 0.49 for D-Pyr; 437.6 +/- 68.4 vs. 156.5 +/- 39.6 for CrossLaps). Z scores of BMD at mid-radius as well as lumbar spine and femoral neck were significantly higher in acromegalic patients compared to control subjects (1.086 +/- 0.311 vs. -0.060 +/- 0.274 for mid-radius; 1.022 +/- 0.280 vs. 0.319 +/- 0.165 for lumbar spine; 1.292 +/- 0.347 vs. 0.232 +/- 0.264 for femoral neck). CONCLUSIONS: The present study revealed that a decrease in percent fat mass and an increase in percent lean body mass were observed in Japanese patients with active acromegaly. Bone mineral density at all sites and bone metabolic markers were also increased in acromegaly. The present findings provide additional evidence that the GH/IGF-I axis might play an important role in the maintenance of bone mass as well as the regulation of body composition in Japanese adults.

Absorptiometry, Photon↗

PubMed2001

Brain from bone: efficient "meta-differentiation" of marrow stroma-derived mature osteoblasts to neurons with Noggin or a demethylating agent.

Bone marrow stromal cells are able to differentiate into adipogenic, chondrogenic, myogenic, osteogenic, and cardiomyogenic lineages, all of which are limited to a mesoderm-derived origin. In this study, we showed that neurons, which are of an ectoderm-origin, could be generated from marrow-derived stromal cells by specific inducers, fibronectin/ornithine coating, and neurosphere formation. The neurons generated from marrow stroma formed neurites, expressed neuron-specific markers and genes, and started to respond to depolarizing stimuli as functional mature neurons. Among stromal cells, isolated mature osteoblasts which had strong in vivo osteogenic activity could be efficiently converted into functional neurons. This transdifferentiation or meta-differentiation was enhanced by Noggin, an inhibitor of bone morphogenetic proteins, in comparison with 5-azacytidine, a demethylating agent capable of altering the gene expression pattern. Marrow stroma is therefore a potential source of cells for neural cell transplantation.

Animals↗

PubMed2001

An atypical case of sporadic Creutzfeldt-Jakob disease with Parkinson's disease.

We report here an autopsy case of a 64-year-old female with slowly progressive dementia and parkinsonism in a 4-year-long clinical course. Post-mortem examination revealed a severely atrophic brain with spongiform degeneration, neuronal loss and gliosis in the gray matter. Many prion protein plaque deposits were present in the occipital lobe, amygdala and cerebellum. Additionally, Lewy bodies were observed in the brainstem. Prion protein gene analysis of the patient revealed polymorphism at the codon-129 valine heterozygote. This genotype is known to sometimes accompany a missense mutation of the gene in uncommon hereditary prion diseases, but no mutation was found in the open reading frame. Thus, it might be suggested that this case showed simultaneously the features of both sporadic Creutzfeldt-Jakob disease (CJD) with codon-129 valine and Parkinson's disease. However, the predisposing factors for contracting both diseases simultaneously remain to be determined, because the incidence of Parkinson's disease accompanied by CJD is very low.

Aged↗

PubMed2001

Repair of a fistula between the bladder and the perineal skin by femoral gracilis flap interposition.

The successful repair of a fistula between the bladder and the perineal skin using a femoral gracilis flap is reported. A 70-year-old woman, who 10 years previously had undergone a total hysterectomy for uterine cancer, developed a fistula between the bladder and the perineal skin after she underwent Mile's operation for rectal cancer. Initially, an attempt was made to repair the fistula by the transabdominal approach. This failed, probably because of the lack of supporting tissue between the bladder and the perineal skin. The second repair was performed with plastic surgeons. A secure three-layer bladder closure was accomplished. A right femoral gracilis flap was developed and rotated 180 degrees to fill the defect in the skin and subcutaneous tissue. Four weeks after surgery, cystography revealed no fistula or urinary leakage and the drainage catheter was removed. Femoral gracilis flap interposition was successful for repair of a fistula between the bladder and the perineal skin when there was no supporting tissue due to extensive exenteration in the surgical removal of rectal cancer and after other repair procedures had been unsuccessful.

Aged↗

PubMed2001

Deformation of the bladder due to collateral circulation caused by thrombosis of the left femoral vein.

A thrombus in the lower extremities as well as in its collateral circulation in the pelvis are not unusual conditions; however, bladder deformation due to such collateral circulation has not previously been reported. A case is presented of bladder deformation to the right due to collateral circulation caused by a thrombus in the lower left extremity in a 51-year-old man.

Collateral Circulation↗

PubMed2001

Higher expression of K-ras is associated with parathyroid hormone-related protein-induced hypercalcaemia in renal cell carcinoma.

OBJECTIVES: To determine whether the K-ras oncogene is associated with parathyroid hormone-related protein (PTHrP) production in renal cell carcinoma (RCC) and whether the serum value of PTHrP is related to the patients' survival. PATIENTS AND METHODS: The serum levels of PTHrP and corrected serum calcium levels were analysed in 51 consecutive patients (29 men and 22 women, mean age 63.7 years, range 33-82) with newly diagnosed RCC. Matched pairs were analysed of the mRNA levels of K-ras and PTHrP in tumour and in corresponding non-tumour tissue originating from the same patient, using the polymerase chain reaction after reverse transcription. RESULTS: Seven patients had elevated serum PTHrP values at the diagnosis of RCC. The mRNA expression of K-ras and PTHrP were detected in both tumour and non-tumour tissues, with K-ras mRNA levels being higher in the former than the latter (P < 0.05), and correlated with tumour stage (P < 0.05). There were no differences in PTHrP mRNA levels between the tissues. Furthermore, the mRNA levels of K-ras and PTHrP in seven tumours from patients with high serum values of PTHrP were higher than in tumours from those with normal values (both P < 0.01). The expression of mRNAs of K-ras and PTHrP was positively correlated (r = 0.771, P < 0.001). In seven patients with high serum PTHrP values the mRNA levels of PTHrP correlated with serum values of PTHrP and calcium (r = 0.875, P < 0.01 and r = 0.762, P < 0.05, respectively). Kaplan-Meier plots of survival rate in patients with elevated or normal serum PTHrP showed that high serum PTHrP was associated with a shorter overall survival (P < 0.05). The Cox proportional hazards model showed that serum PTHrP was an independent predictor of overall survival (P < 0.05). CONCLUSIONS: These findings suggest that K-ras may be associated with PTHrP-induced hypercalcaemia and that PTHrP levels may reflect the aggressiveness of tumour cells through the K-ras oncogene in RCC.

Adult↗

PubMed2001

Inactivation of parvovirus B19 in coagulation factor concentrates by UVC radiation: assessment by an in vitro infectivity assay using CFU-E derived from peripheral blood CD34+ cells.

BACKGROUND: Nonenveloped and thermostable viruses such as parvovirus B19 (B19) can be transmitted to patients who are receiving plasma-derived coagulation factor concentrates treated by the S/D method for inactivating enveloped viruses. Therefore, it is important to develop and validate new methods for the inactivation of nonenveloped viruses. STUDY DESIGN AND METHODS: Suspensions of B19 in coagulation factor concentrates (FVIII) were irradiated with UVC light. B19 infectivity was determined by an indirect immunofluorescence assay using CFU-E, as a host cell, derived from peripheral blood CD34+ cells. The effects of catechins on B19 infectivity and on FVIII activity after UVC illumination were also examined. RESULTS: The indirect immunofluorescence assay estimated the B19 infectivity of samples containing virus copies of 10(5) to 10(11) per 10 microL to be a median tissue culture-infectious dose of 10(0.3) to 10(5.4) per 10 microL. B19 was inactivated by 3 log at 750 J per m(2) of UVC radiation and was undetectable after 1000 or 2000 J per m(2) of irradiation. However, FVIII activity decreased to 55 to 60 percent of pretreatment activity after 2000 J per m(2) of UVC radiation. This was inhibited in the presence of rutin or catechins. Epigallocatechin gallate could maintain FVIII activity at almost 100 percent of pretreatment activity after 2000 J per m(2) of UVC radiation, while B19 infectivity was decreased to undetectable levels, which resulted in >3.9 log inactivation. CONCLUSION: UVC radiation in the presence of catechins, especially epigallocatechin gallate, appears to be an effective method of increasing the viral safety of FVIII concentrates without the loss of coagulation activity.

Antigens, CD34↗

PubMed2001

Effects of poly(ethyleneglycol)-modified hemoglobin vesicles on agonist-induced platelet aggregation and RANTES release in vitro.

We studied the effects of hemoglobin-vesicles modified with PEG (PEG-HbV), a type of liposome-encapsulated hemoglobin (LEH), on human platelet functions in vitro. The effect of a low concentration of PEG-HbV (Hb; 5.8 mg/dl) was assessed by examining an agonist-induced aggregation response, and that of relatively high concentrations of PEG-HbV (Hb; 0.29, 1 and 2 g/dl) by measuring the release of RANTES (Regulated upon activation, normal T-cell expressed and presumably secreted) from platelets, which is regarded as a marker of platelet activation. The preincubation of platelets with PEG-HbV at 5.8 mg/dl of Hb did not affect platelet aggregation induced by collagen, thrombin and ristocetin. The pretreatment of platelet-rich plasma (PRP) with PEG-HbV at concen trations up to 2 g/dl of Hb had no aberrant effects on the collagen-induced RANTES release. Furthermore, the collagen-induced release of RANTES from PRP was not affected by longer incubation with PEG-HbV at 2 g/dl of Hb. The basal levels of RANTES from PRP were unchanged in the presence of PEG-HbV. These results suggest that PEG-HbV, at the concentrations studied, have no aberrant effects on platelet functions in the presence of plasma.

Chemokine CCL5↗