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H Iwamoto

Publications and source records attributed to H Iwamoto.

At least 19 recordsLinked to original sources
PubMed2006

The role of plasmapheresis therapy for perioperative management in ABO-incompatible adult living donor liver transplantation.

BACKGROUND: Although living donor liver transplantation (LDLT) was established as a treatment for end-stage liver disease in Japan, the indication for LDLT across an ABO-incompatible barrier remains controversial. The purpose of this study was to elucidate the role of plasmapheresis in incompatible LDLT. METHODS: Eleven adult patients (seven men and four women) who underwent incompatible LDLT were enrolled in this study. Of these three patients had hepatocellular carcinoma, three chronic hepatitis C, one Wilson's disease, one autoimmune hepatitis, one chronic hepatitis B, one hemochromatosis, and one fulminant hepatic failure. The immunosuppressive regimen consisted of tacrolimus, prednisolone, mycophenolate mofetil (or cyclophosphamide), and prostaglandin E1 in all patients. Multiple plasmapheresis was performed perioperatively to reduce the recipient's antibody titers against the donor's blood type. RESULTS: Plasmapheresis was useful for the reduction of the recipient's antibody titers to x 16 or lower before and after transplantation. There was no difference in transplant outcome between the 11 patients with incompatible blood group and 30 patients with identical or compatible blood groups. DISCUSSION: Major postoperative complications such as intrahepatic biliary complications and hepatic necrosis may occur in incompatible transplantation. Several investigators suggested that anti-immunoglobulin (Ig) M and anti-IgG antibody titers sustained these complications. The antibody titers must be decreased sufficiently with plasmapheresis. An elevation of anti-ABO titers after transplantation may be a predictive risk factor for increased mortality and morbidity. In order to perform LDLT in a safer manner, plasmapheresis is an indispensable treatment to improve the outcome of ABO-incompatible cases.

ABO Blood-Group System↗
PubMed2006

Age-related changes in the intramuscular distribution of melanocytes in the Silky fowl.

1. The characteristics of melanocyte distribution in skeletal muscles in the Silky fowl were investigated in association with growth. 2. Pectoralis (PT) and iliotibialis lateralis (ITL) muscles from 1-, 3-, 5-, 10-, 20- and 30-week-old Silky males were weighed and collagen type I was detected in frozen sections immunohistochemically. 3. Melanocytes were observed in the collagen type I-immunopositive endomysium and perimysium in both muscles. 4. Image analysis indicated that the total area occupied by melanocytes in histological sections sharply decreased from 0.61% to 0.16% in PT muscle and from 1.67% to 0.33% in ITL muscle at 1 to 3 weeks, and then gradually decreased. The melanocyte area was larger in ITL muscle than in PT muscle until 10 weeks of age. 5. We concluded that the proportion of intramuscular melanocytes in the Silky fowl differs between types of muscles in the early stages of development, and it decreases with growth.

Aging↗
PubMed2006

Effects of nutritional level on muscle development, histochemical properties of myofibre and collagen architecture in the pectoralis muscle of male broilers.

1. The effects of nutritional level on muscle development, histochemical properties of myofibre and collagen architecture in the pectoralis muscle were evaluated using male broilers of Red Cornish x New Hampshire stock, reared on diets of high nutritional value for up to 80 d (H80d) and low nutritional value for up to 80 d (L80d, same age as H80d) or 95 d (L95d, same body weight as H80d). 2. The total live weight and the weight of pectoralis muscle were lower in L80d than in both H80d and L95d. The muscle weight as a percentage of live weight was 8.7% in L80d, 10.7% in H80d and 11.5% in L95d. 3. Pectoralis muscle was composed only of type IIB myofibres and showed no differences in myofibre type composition among the chicken groups. The largest diameter of type IIB myofibres was observed in L95d, followed by H80d and the smallest in L80d. 4. The total amount of intramuscular collagen did not differ among the chicken groups (1.92 to 1.99 mg/g). Types I and III collagens were immunohistochemically detected in both the perimysia and endomysia. The thin perimysia around the primary myofibre fascicles showed larger width in H80d than L80d and L95d, and also the thick perimysia around the secondary fascicles in H80d than L80d. 5. The collagen structure of the perimysium was most developed in H80d, followed by L95d and on the least in L80d. The development of perimysial collagen fibres could be enhanced by a rapid growth rate of the muscle induced by high nutritional level and depressed by a slow growth rate with low nutritional foods. 6. The endomysial collagen architecture was observed as a felt-like tissue of the fibril bundles with many slits. The thinnest endomysial wall was observed in L80d, followed by H80d and the thickest in L95d. 7. From these results, it was indicated that foods of high nutritional value could enhance growth of the pectoralis muscle of broilers, and this is accompanied by hypertrophy of the type IIB myofibres and development of the perimysial collagen architecture.

Animal Feed↗
PubMed2006

Case study of a pregnant woman with decidualized ovarian endometriosis whose preoperative findings suggested malignant transformation.

BACKGROUND: Because both decidualization and malignant transformation of endometriosis are characterized by mural nodules on the wall of the cyst, the preoperative differential diagnosis is reportedly difficult. CASE: A 31-year-old woman was referred to our hospital at ten weeks of gestation. Sonographic examination revealed an intrauterine gestational sac and ovarian endometrial cyst. At 21 weeks of gestation, characteristic findings associated with malignant transformation of ovarian endometriosis were seen on color-flow Doppler sonography and contrast magnetic resonance imaging. Under the diagnosis of malignant transformation of ovarian endometriosis, right salpingo-oophorectomy was performed at 22 weeks' gestation. However, histopathologic examination revealed ovarian endometriosis with marked decidual changes but no evidence of malignancy. CONCLUSION: During pregnancy, intracystic vascularized excrescences of an endometrial cyst indicate not only malignant transformation but also decidualization. Thus, the preoperative differential diagnosis is reportedly difficult. However, the present findings of decidualization on magnetic resonance imaging seemed to be slightly different from those of malignant transformation, and therefore, might help distinguish decidualized endometriosis from malignant transformation preoperatively.

Adult↗
PubMed2005

Optimal dose and target trough level in cyclosporine and tacrolimus conversion in renal transplantation as evaluated by lymphocyte drug sensitivity and pharmacokinetic parameters.

We evaluated the relative clinical potency of cyclosporine (CyA) and tacrolimus (Tac) using pharmacodynamic and pharmacokinetic parameters of the drug to obtain the most suitable converting dose and target trough level. The relative pharmacodynamic potency was examined by the mean ratio of drug concentrations giving 50% inhibition of blastogenesis of lymphocytes (IC50) in 66 chronic renal failure patients. The relative potency estimated from clinical pharmacokinetic parameters was examined by the mean ratio of each pharmacokinetic parameter value of CyA versus Tac. The pharmacokinetic parameters were estimated by 12-hour monitoring of drug blood concentrations in seven CyA patients and seven Tac patients. The mean IC50 ratio of CyA and Tac (CyA/Tac of IC50) was 25.1. The mean area under the concentration-time curve (AUC) ratio (CyA/Tac of AUC) was 25.5, the mean trough level (C(min)) ratio (CyA/Tac of C(min)) was 13.2, and the mean dose per body weight ratio was 25.2. The relative potency estimated from AUC that is the most reliable pharmacokinetic parameter for the estimation of clinical efficacy of calcineurin inhibitors appeared to agree with the relative pharmacodynamic potency estimated from IC50. The data suggest that TAC 25-fold more potent than CyA, which represents a suitable converting dose ratio, and that target trough level of CyA is about 13-fold greater than Tac based on CyA/Tac of C(min). We conclude that these relative values may be useful to estimate the suitable dose and target trough levels to convert between CyA and Tac.

Area Under Curve↗
PubMed2004

Successful case of adult ABO-incompatible liver transplantation: beneficial effects of intrahepatic artery infusion therapy: a case report.

BACKGROUND: In Japan ABO-incompatible liver transplantation has been done on >100 occasions up to 2003. However, <30% are cases involving adults. The difficultly of ABO-incompatible liver transplantation is associated with the high frequency of humoral rejection and local disseminated intravascular coagulation (DIC), leading to many postoperative complications. We report a successful case of adult ABO-incompatible liver transplantation with the use of an intrahepatic artery infusion. METHODS: A 36-year-old man with Wilson disease, underwent living donor liver transplantation from an ABO-incompatible donor. The immunosuppressive therapy included multiple perioperative plasmaphereses, splenectomy, and treatment with tacrolimus, methylprednisolone, and cyclophosphamide. The dose and blood level of tacrolimus were the same as in ABO-compatible cases. In addition to these therapies, we administered an intrahepatic arterial infusion with prostaglandin (PG) E1 alone. RESULTS: After perioperative plasmapheresis and cyclophosphamide, antidonor blood group antibody titers remained undiluted and without vascular complications throughout the postoperative course, but there was a tendency for bleeding that continued for 10 days after transplantation. On postoperative day 10, a reexploration was performed for intraabdominal bleeding. During another operation on postoperative day 59 a biloma was found and drained. The patient has now survived for 120 days after transplantation with normal liver function. CONCLUSIONS: Beneficial effect of intrahepatic artery infusion with PGE1 seems to be useful in adult ABO-incompatible liver transplantation.

ABO Blood-Group System↗
PubMed2004

Growth changes of the collagen content and architecture in the pectoralis and iliotibialis lateralis muscles of cockerels.

1. Growth changes of the collagen content and architecture in the pectoralis (PT) and iliotibialis lateralis (ITL) muscles were examined using cockerels from 1 to 14 weeks of age. 2. Total collagen content in PT muscle showed little change, but in ITL muscle reached a maximum at 5 weeks and thereafter decreased slightly until 14 weeks. The collagen content was markedly larger in ITL muscle after 5 weeks. Pyridinoline content of collagen increased abruptly from 5 to 14 weeks in both muscles, but no difference between muscle types was detected. 3. The cell size of the endomysial honeycombs increased with the development of myofibres, and the mesh size of the perimysium around the honeycombs enlarged. 4. In both muscles endomysia were an incomplete network of collagen fibrils with many foramina at one week, became a very thin membrane of felt-like fabric in 2 to 5 weeks and thereafter increased in thickness until 11 to 14 weeks. 5. Perimysial width around the secondary fasciculus differed between the muscle types after 5 weeks. In the wider perimysium of ITL muscle, the collagen fibres increased in number and size to make a stack of collagen bands around the fasciculus. In the narrower perimysium of PT muscle, a few platelets of collagen fibres also developed. 6. The perimysial collagen fibre at 1 to 2 weeks had a smooth surface and appeared to be composed of fine collagen fibrils. The fibre at 11 to 14 weeks showed a rugged surface and was composed of coarser collagen bundles that combined with each other into a net-like configuration with very slim meshes. 7. Our results showed that the collagenous components of chicken intramuscular connective tissue changed markedly during the early period of muscle growth in distribution, architecture and quality but with little difference in quantity.

Animals↗
PubMed2004

Developmental states of the collagen content, distribution and architecture in the pectoralis, iliotibialis lateralis and puboischiofemoralis muscles of male Red Cornish x New Hampshire and normal broilers.

1. Developmental states of the collagen content, distribution and architecture in the pectoralis (PT), iliotibialis lateralis (ITL) and puboischiofemoralis (PIF) muscles of male Red Cornish x New Hampshire (RN, 80 d, body weight 2.9 kg) and normal (3.1 kg) broilers were evaluated. 2. In PT muscle the total amount of collagen was significantly greater in RN broilers (3.33 mg/g) than in normal ones (1.71 mg/g). This higher collagen content in RN broilers was based mainly on the closer mesh sizes of endomysial honeycomb. The collagen structures in the perimysia also differed between broiler types, when more collagen fibres were observed in RN broilers. 3. ITL muscle contained total collagen of 4.10 to 5.00 mg/g. Types I and III collagens were distributed on the perimysia at higher percentages in RN broilers (31.6%, 37.2%) than normal (15.6%, 30.8%), respectively. The thick bands of tough collagen fibres characteristic of ITL muscle perimysium in cockerels had not yet developed in these broilers. 4. Total collagen was 4.63 to 6.29 mg/g in PIF material with fascia. In PIF muscle the perimysial collagen fibres had not yet attained their full growth but consisted of densely packed fibrils. PIF muscle was characterised by the earlier maturing collagen structure. 5. These results show that a perimysial collagen structure in broilers is still in an undeveloped state. It is supposed that tenderness of broiler meat is attributed mainly to characteristics of the collagen distribution, in which the majority of types I and III collagens is distributed on the closer mesh of endomysial honeycomb.

Animals↗
PubMed2004

Incidence and prognosis of gastric cancer in a population-based cohort survey: the Hisayama study.

BACKGROUND: No population-based cohort studies have been undertaken to evaluate the incidence and prognosis of gastric cancer. The purpose of this investigation was to clarify the incidence and fatal prognosis of gastric cancer and to determine the factors that contribute to the prognosis in a general Japanese population in Hisayama using a prospective study design. METHODS: From 1988 to 1998 a total of 2605 subjects aged 40 years or older with no history of gastrectomy or gastric cancer were followed-up prospectively after a health examination. The diagnosis of gastric cancer was based on clinical records or autopsy findings. RESULTS: During the follow-up period, 76 subjects developed gastric cancer. The age-adjusted incidence of gastric cancer for men (4.9 per 1000 person-years) was 4-fold higher than that for women (1.2, P < 0.05). In men, the incidence of gastric cancer increased with advancing age, but this trend was not observed in women. The age- and sex-adjusted 5-year survival rate was significantly higher in cancers of the middle third of the stomach than in those of the upper third of the stomach. The survival rate was higher in cancers of well-differentiated adenocarcinoma than in those of the other histological types. There were no cases of cancer-related death among the early gastric cancers during the follow-up period. CONCLUSIONS: Our data suggest that men are at higher risk of gastric cancer than women in the general Japanese population. Clinical stage, histological type, and site of cancer in the stomach contribute to a fatal prognosis.

Adult↗
PubMed2003

Comparison of collagen fibre architecture between slow-twitch cranial and fast-twitch caudal parts of broiler M. latissimus dorsi.

1. Collagen fibre architectures of perimysium and endomysium in the slow-twitch cranial and fast-twitch caudal parts of broiler M. latissimus dorsi were compared. 2. Type I and III collagens were distributed in both perimysium and endomysium as indicated by their positive immunohistochemical reactions to polyclonal antibodies. 3. Cells invested by endomysium with no myofibres were larger in the cranial part because of the presence of larger slow-twitch myofibres. The honeycomb structure of endomysium was divided into several parts by thick perimysium. 4. The thick perimysial collagen fibres with parallel fibrils, which were interconnected by the loose reticular fibrils and thin fibres, were more numerous and thicker in the cranial part than the caudal. 5. Thick endomysial sidewall of cells in the cranial part was composed of a rougher reticulum of slightly thicker collagen fibrils compared with the thin sidewall in the caudal part. 6. These results indicated that both perimysial constitutions of collagen fibres and endomysial collagen fibrils had attained much larger growth in the slow-twitch cranial part than the fast-twitch caudal in broiler latissimus dorsi muscle.

Animals↗
PubMed2003

Placental site trophoblastic tumor: p53 gene analysis.

BACKGROUND: Placental site trophoblastic tumor (PSTT) is the rarest type of trophoblastic neoplasm. Because of its rarity, the clinical behavior and pathogenesis of PSTT are still unclear. CASE: A 20-year-old woman presented with secondary amenorrhea and irregular vaginal bleeding. Examination of the patient revealed elevated serum hCG and a uterine mass. The specimen obtained by curettage was diagnosed as possible PSTT. The patient was treated with two cycles of EMA/CO, but her uterine mass increased in size. Subsequently, she underwent total abdominal hysterectomy. Microscopic observation revealed a PSTT. To estimate the status of expression of p53 protein and to determine whether p53 gene mutation was present in this PSTT, we carried out immunohistochemical staining for p53 and PCR-SSCP analysis. Immunohistochemical staining for p53 revealed intense nuclear labeling, but no p53 gene mutation was detected in exons 5-8. CONCLUSION: Analysis of the p53 gene may aid understanding of the pathogenesis of PSTT.

Adult↗
PubMed2002

Near field optical microscopy in aqueous solution: implementation and characterization of a vibrating probe.

Near field optical microscopy (NSOM) is one of the possible solutions to circumvent the diffraction limit, but the control of the optical probe in solution has been a technical challenge for practical applications. Most recently, it has been shown that the pipette used in the scanning ion conductance microscope can be modified to form a high resolution near field optical probe. When combined with a novel distance modulation mechanism, a robust near field microscope can be constructed for operation in aqueous solution. In this paper, we present technical details of this design and a further characterization of the NSOM system for imaging in solution. Fundamental limitations of this approach in comparison to other systems are also discussed. Based on the current technology, it is concluded that better than 50 nm resolution should be achievable with this technique for fluorescence, as well as fluorescence resonance energy transfer, imaging of biological specimens.

Microscopy↗
PubMed2002

Comparison of the histological and histochemical properties of skeletal muscles between carbon dioxide and electrically stunned chickens.

1. Histological and histochemical profiles of Musculus pectoralis (PT, type IIB fibres), M. iliotibialis lateralis (ITL, types IIA + IIB fibres) and M. puboischiofemoralis pars medialis (PIF, type I fibres) were compared in carbon dioxide (37%, 70 s) and electrically (14 V, 5 s) stunned male chickens. 2. Muscle materials were taken at 0, 4 and 24 h from carcases dressed and cooled with ice-water mixture for 30 min. Glycogen and fat contents, and adenosine triphosphatase and reduced nicotinamide adenine dinucleotide dehydrogenase activities of fibres were measured. 3. In PT muscle at 0 h, gas stunned chickens showed many fibres with high glycogen content but those electrically stunned contained few such fibres. Fibres from gas stunned birds had lost almost all their glycogen after 24 h of cold storage. 4. In the ITL muscle of gas stunned chickens at 0 h residual glycogen was observed in type IIB fibres. In contrast, in the electrically stunned birds it was in type IIA, showing the different effects of the stunning methods. During cold storage, glycogen disappeared earlier in type IIB than IIA fibres. 5. In PIF muscle with fibres of low glycogen content, the gas stunned chickens maintained a good fibre structure for 4 h or more, but the electrically stunned had already lost intact fibre structure at 4 h. 6. These results indicated that the carbon dioxide stunning was a better method for chicken welfare and meat quality than electrical stunning.

Adenosine Triphosphatases↗
PubMed2002

Renin-producing serous cystoadenocarcinoma of the ovary: a case report.

BACKGROUND: Only a few renin-producing ovarian tumors have been reported, and most such ovarian tumors have been sex cord/stromal tumors. Renin-producing ovarian epithelial tumors are quite rare. CASE: A 46-year-old woman presented with hypertension and hypokalemia. Examinations of the patient revealed elevated plasma renin activity, hyperaldosteronism and a pelvic mass. Subsequently, a right ovarian tumor mass was resected. Microscopic observation of the tumor revealed a well-differentiated serous cystadenocarcinoma. Immediately after surgery, blood pressure, serum potassium, plasma renin activity and plasma aldosterone levels returned to normal ranges. RT-PCR analysis and immunohistochemical staining of this tumor indicated that it was producing renin. CONCLUSION: This is the first report of a renin-producing ovarian serous cystadenocarcinoma.

Aldosterone↗
PubMed2001

Characterization of the metal-substituted dipeptidyl peptidase III (rat liver).

Dipeptidyl peptidase III (DPP III) (EC 3.4.14.4), which has a HELLGH-E (residues 450-455, 508) motif as the zinc binding site, is classified as a zinc metallopeptidase. The zinc dissociation constants of the wild type, Leu(453)-deleted, and E508D mutant of DPP III at pH 7.4 were 4.5 (+/-0.7) x 10(-13), 5.8 (+/-0.7) x 10(-12), and 3.2 (+/-0.9) x 10(-10) M, respectively. The recoveries of the enzyme activities by the addition of various metal ions to apo-DPP III were also measured, and Co(2+), Ni(2+), and Cu(2+) ions completely recovered the enzyme activities as did Zn(2+). The dissociation constants of Co(2+), Ni(2+), and Cu(2+) ions for apo-DPP III at pH 7.4 were 8.2 (+/-0.9) x 10(-13), 2.7 (+/-0.3) x 10(-12), and 1.1 (+/-0.1) x 10(-14) M, respectively. The shape of the absorption spectrum of Co(2+)-DPP III was very similar to that of Co(2+)-carboxypeptidase A or Co(2+)-thermolysin, in which the Co(2+) is bound to two histidyl nitrogens, a water molecule, and a glutamate residue. The absorption spectrum of Cu(2+)-DPP III is also very similar to that of Cu(2+)-thermolysin. The EPR spectrum and the EPR parameters of Cu(2+)-DPP III were very similar to those of Cu(2+)-thermolysin but slightly different from those of Cu(2+)-carboxypeptidase A. The five lines of the superfine structure in the perpendicular region of the EPR spectrum in Cu(2+)-DPP III suggest that nitrogen atoms should coordinate to the cupric ion in Cu(2+)-DPP III. All of these data suggest that the donor set and the coordination geometry of the metal ions in DPP III, which has the HExxxH motif as the metal binding site, are very similar to those of the metal ions in thermolysin, which has the HExxH motif.

Animals↗