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Biomedical subjects

Y Hayashi

Publications and source records attributed to Y Hayashi.

At least 163 records · Page 9Linked to original sources
PubMed2001

Adult-onset herpes simplex virus hepatitis with diffuse myofibroblastic transformation of hepatic stellate cells (Ito cells) in non-necrotic areas.

The myofibroblastic transformation of hepatic stellate cells (HSC; also known as Ito cells) usually occurs following necrosis of adjacent liver cells. No report has previously found that such a transformation occurs in herpes simplex virus (HSV) hepatitis. We present an autopsy case of HSV hepatitis with myofibroblastic transformation of HSC that is different from the usual transformation of HSC. The patient was a 66-year-old woman who had received various therapies for cutaneous T-cell lymphoma. An autopsy revealed submassive hepatic necrosis with hemorrhage due to HSV hepatitis. HSV infection was confirmed by DNA in situ hybridization in liver tissue. Immunohistochemical staining for alpha-smooth muscle actin (ASMA) showed a strong positive reaction in almost all of the HSC in non-necrotic areas. However, in necrotic areas, the HSC were completely negative for ASMA. These findings indicate that not only liver cells but also HSC can become necrotic in HSV hepatitis. In contrast, in non-necrotic areas, almost all of the HSC showed active transformation to myofibroblasts.

Actins↗
PubMed2001

Malignant phyllodes tumor of the breast with expression of osteonectin and vinculin.

Phyllodes tumor is a very rare neoplasm which accounts for 2.5% of all fibroepithelial lesions of the breast. The mesenchymal component of a malignant phyllodes tumor frequently contains heterologous components. We report a case of malignant phyllodes tumor. The patient was a 40-year-old woman with a lump on the left breast. Histological examination revealed the lump to be a malignant phyllodes tumor with foci of liposarcomatous differentiation. The mesenchymal tumor cells, including those in the liposarcomatous components, were found to express vimentin, osteonectin and vinculin. However, they showed no immunoreaction to CAM 5.2, desmin, alpha-smooth muscle actin (ASMA), neuron-specific enolase (NSE) nor S-100. Ultrastructurally, the mesenchymal tumor cells were found to have abundant cytoplasmic organelles, but there was no evidence showing their differentiation to myofibroblasts. Further studies will be necessary to elucidate the significance of vinculin and osteonectin expression in malignant phyllodes tumor.

Adult↗
PubMed2001

Autopsy case of alcoholic hepatitis and cirrhosis treated with corticosteroids and affected by Pneumocystis carinii and cytomegalovirus pneumonia.

A case of the very early phase of Pneumocystis carinii pneumonia in a human immunodeficiency virus (HIV)-negative man with alcoholic hepatitis and cirrhosis treated with steroids is presented. A 40-year-old man with a 10-year history of alcohol abuse was admitted to hospital with jaundice, fever and macrohematuria. Laboratory examinations revealed neutrophilic leukocytosis and a serum bilirubin level of 13.9 mg/dL. The serum bilirubin level rose to 28.5 mg/dL over 1 month. Prednisolone administered orally for 10 days produced a slight improvement in the jaundice and fever. After an interval of a week, it was resumed and maintained for 22 days (total dose, 1555 mg) until the patient died of a massive hemorrhage from ruptured vessels of a gastric ulcer. An autopsy disclosed P. carinii pneumonia in the lower lobe of the left lung, cytomegalovirus infection in both lungs and the esophagus, and esophageal candidiasis. To our knowledge, this is the first report of P. carinii pneumonia together with cytomegalovirus infection in an HIV-negative alcoholic patient. The present case suggests that a rare opportunistic infection such as P. carinii pneumonia might be caused by treating cirrhosis and alcoholic hepatitis with corticosteroids, even if only for a relatively short period.

Adrenal Cortex Hormones↗
PubMed2001

Histological study of PIVKA-II expression in hepatocellular carcinoma and adenomatous hyperplasia.

Although serum concentration of protein induced vitamin K absence or antagonist II (PIVKA-II) has been widely used for diagnosing hepatocellular carcinoma (HCC), little information is available concerning tissue PIVKA-II as an immunohistochemical marker for liver histology. In this study, we examined the expression of PIVKA-II in precancerous nodules (adenomatous hyperplasia) and various differentiation grades of HCC by immunohistochemical study using the monoclonal anti-PIVKA-II antibody (MU-3). We examined the relationship between tissue PIVKA-II staining and serum PIVKA-II level, tumor histology and tumor size. PIVKA-II was mainly detected in the cytoplasm of the HCC cells. The positive rates of PIVKA-II were as follows: adenomatous hyperplasia (AH), 0% (0/9); well-differentiated HCC, 65% (15/23); moderately differentiated HCC, 85% (22/26); poorly differentiated HCC, 54% (7/13). The expression of tissue PIVKA-II staining in moderately differentiated HCC was significantly higher than in well- or poorly differentiated HCC, whereas the serum PIVKA-II level in poorly differentiated HCC was higher than well- or moderately differentiated HCC. There was no relationship between the expression of PIVKA-II in cancer tissues and serum levels of PIVKA-II. Immunohistochemical studies revealed that PIVKA-II was expressed even in small-sized or well-differentiated HCC cells, but expression was not detected in AH. It was concluded that PIVKA-II is a useful immunohistochemical marker, even in small-sized or well-differentiated HCC.

Adenoma↗
PubMed2001

Primary and salvage urethroplasty using Mathieu meatal-based flip-flap technique for distal hypospadias.

BACKGROUND: Numerous surgical procedures have been attempted for correction of distal hypospadias. The Mathieu procedure was employed in this study for secondary cases as well as primary cases. METHODS: The length of the skin flap is determined by measuring the distance from the meatus to the glans tip and then the ventral meatal-based skin flap is incised. The proximal skin flap is flipped and anastomosed to the distal urethral plate. Additionally, subcutaneous tissue of the flipped flap is sutured to cover the original suture lines completely. RESULTS: The Mathieu urethroplasty was successful in one stage in 13 of the 16 primary repair cases (81%). Twelve of the 13 (92%) who underwent a secondary Mathieu procedure were successfully repaired with no problems. An overall success rate of 86% was achieved at the first operation for both primary and secondary cases. In the remaining 14% of the cases, success was achieved with only one additional procedure. CONCLUSIONS: The Mathieu flip-flap procedure is feasible for relatively short urethral defects if the ventral penile skin demonstrates adequate mobility and there is no chordee. Even in patients who require revisional hypospadias surgery, the Mathieu procedure can give excellent functional and cosmetic results.

Adolescent↗
PubMed2001

One-stage repair of moderately severe hypospadias using a transverse preputial tubularized island flap.

BACKGROUND: Transverse preputial tubularized island flap (TPTIF) urethroplasty has been used for the repair of moderately severe hypospadias since Duckett described the procedure in 1980. In spite of the excellent results reported by Duckett, subsequent studies showed high complication rates. A TPTIF procedure modified to reduce the complication rate is presented. METHODS: Between 1996 and 1997, 13 boys with moderately severe hypospadias were repaired with the TPTIF procedure. Patient age ranged from 10 months to 3 years with an average age of 23 months. To prevent urethrocutaneous fistula, the neourethra was constructed with a two-layer closure and the portion of anastomosis was wrapped between the native urethra and the neourethra with the tissue of the corpus spongiosum. RESULTS: The moderately severe hypospadias was repaired without complication in 12 of 13 patients. A urethrocutaneous fistula developed at the midshaft of the penis in one patient. No meatal stenosis, urethral stricture or diverticulum developed. CONCLUSION: Transverse preputial tubularized island flap urethroplasty provided excellent cosmetic and functional results for moderately severe hypospadias, and postoperative complications could be decreased by the two-layer closure of the neourethra and application of the wrapping technique of the proximal anastomosed portion with corpus spongiosum tissue.

Child, Preschool↗
PubMed2001

Tubularized incised-plate urethroplasty for secondary hypospadias surgery.

PURPOSE: Reoperation for failed hypospadias has been considered to be seriously bothersome because abundant penile skin does not tend to remain for urethroplasty or for penile shaft skin coverage. In this study, the tubularization of incised urethral plate was employed for those who had no excessive penile skin after failure of hypospadias repair. METHODS: Five patients with hypospadias underwent tubularized incised-plate urethroplasty as salvage surgery. The surgical techniques necessary for the performance of the reoperation were not different from those for the primary repair. The urethral plate was incised sufficiently deeply in its midline from the tip of the glans to the regressed meatus. The incised urethral plate was tubularized without tension over a catheter of an appropriate size. RESULTS: Four of those who underwent secondary tubularized incised-plate urethroplasty were successfully repaired without complications. A urethrocutaneous fistula occurred at the corona in the remaining patient. CONCLUSIONS: The absence of preputial skin in reoperative cases makes tubularized incised-plate urethroplasty the ideal option, although the series was small and postoperative duration is still short. In addition, this procedure can give excellent functional and cosmetic results even in patients who require revisional hypospadias surgery.

Adolescent↗
PubMed2001

The modified Koyanagi repair for severe proximal hypospadias.

OBJECTIVE: To report the method and results of a modified one-stage Koyanagi repair (urethroplasty with a parameatal-based and fully extended circumferential foreskin flap) to preserve the vascularity to the peripheral portion of the neourethra, in the repair of severe hypospadias. PATIENTS AND METHODS: Using a skin-incision line as in the original Koyanagi repair, a circumferential incision is made approximately 5 mm proximal to the corona and the urethral plate incised as for repair of chordee. A U-shaped skin incision is then made surrounding the meatus, extended to the dorsal prepuce for approximately 8 mm and parallel to the first incision. The tissue between the prepuce and dartos is dissected on the dorsal side to fix the prepuce as a neourethra to the dartos and to maintain blood supply. After mobilizing the loop-shaped skin flap through the button-hole of the pedicle, the internal and external sides of the loop are sutured to construct a neourethra. Twenty patients (aged 10 months to 9 years) with severe proximal hypospadias underwent the one-stage modified Koyanagi repair. RESULTS: The repair was successful after the initial procedure in 14 patients, but urethrocutaneous fistulae developed in three and meatal stenosis in three. The overall success rate was thus 70%. CONCLUSIONS: There were fewer complications than reported with the original Koyanagi repair, suggesting that the attempted vascular preservation of the neourethra was effective.

Child↗
PubMed2001

Carpal bone movements in gripping action of the giant panda (Ailuropoda melanoleuca).

The movement of the carpal bones in gripping was clarified in the giant panda (Ailuropoda melanoleuca) by means of macroscopic anatomy, computed tomography (CT) and related 3-dimensional (3-D) volume rendering techniques. In the gripping action, 3-D CT images demonstrated that the radial and 4th carpal bones largely rotate or flex to the radial and ulnar sides respectively. This indicates that these carpal bones on both sides enable the panda to flex the palm from the forearm and to grasp objects by the manipulation mechanism that includes the radial sesamoid. In the macroscopic observations, we found that the smooth articulation surfaces are enlarged between the radial carpal and the radius on the radial side, and between the 4th and ulnar carpals on the ulnar side. The panda skilfully grasps using a double pincer-like apparatus with the huge radial sesamoid and accessory carpal.

Animals↗
PubMed2001

Various scoring systems evaluating histologic features of chronic hepatitis C treated with interferon.

Various scoring systems for chronic hepatitis have been proposed; however, there is no standard scoring system for studies of interferon (IFN) therapy in patients with chronic hepatitis C. The aims of this study were to determine the most useful system reflecting histologic changes in biopsy specimens from complete responders and predicting the efficacy of IFN therapy. Patients with chronic hepatitis C were administered IFN-alpha for 6 months. Forty-six patients were included in this study and categorized as complete responders (n = 15), partial responders (n = 24), and nonresponders (n = 7) according to viral and biochemical responses to the therapy. Biopsy specimens obtained from each patient before and after treatment were evaluated under 3 different systems: Histological Activity Index (HAI), modified HAI, and Scheuer classification. Complete responders showed considerable improvement in both grade and stage on the modified HAI and Scheuer classifications. On the HAI, a considerable improvement was observed in grade but not in stage. No significant change was observed in partial responders or nonresponders on any system. Prediction of complete response was not possible under any system, but the pretreatment score reflecting piecemeal necrosis on any 1 of the 3 classifications and the fibrosis score on Scheuer classification were predictors of nonresponse. The modified HAI system and Scheuer classification were amply useful in evaluating histologic changes in complete responders. Scores higher than 4 of the categories reflecting piecemeal necrosis on any system and fibrosis scores of 3 or 4 on Scheuer classification predicted nonresponse to IFN therapy.

Adult↗
PubMed2001

Expression of CD9/motility-related protein 1 (MRP-1) in renal parenchymal neoplasms: consistent expression in papillary and chromophobe renal cell carcinomas.

CD9 is a glycoprotein that is abundant in hematopoietic cells. Recently, it has been reported that CD9 is also present in the human kidney. In this article, we investigated the expression of CD9 using an immunohistochemical technique. We also studied the expression of CD9 protein and messenger RNA (mRNA) in tissue samples of some renal tumors using immunoblotting and reverse-transcription polymerase chain reaction (RT-PCR) analysis. Immunohistochemically, all tumors of papillary and chromophobe renal cell carcinomas (RCCs) and oncocytomas expressed CD9. In addition, CD9 was expressed in 31 of 66 conventional RCCs and 1 of 4 collecting duct carcinomas. On immunoelectron microscopy, CD9 was identified on the plasma membrane of a conventional RCC. The presence of CD9 protein in normal kidneys and various renal tumors, except for a collecting duct carcinoma and an oncocytoma, was confirmed by immunoblotting. On RT-PCR analysis, the expression of CD9 mRNA was observed in 1 normal kidney, 2 conventional RCCs, and 1 oncocytoma. The frequency of immunohistochemical CD9 positivity was significantly higher in papillary and chromophobe RCCs than in collecting duct carcinomas and conventional RCCs, respectively. These results suggest that CD9 may be a beneficial marker in the differential diagnosis between papillary RCCs and collecting duct carcinomas and also between chromophobe and conventional RCCs.

Adult↗
PubMed2001

Mutational analysis of the BMP-1 gene in patients with gastroschisis.

BACKGROUND: Gastroschisis is a rare abdominal wall defect. Although the pathogenesis of gastroschisis is unknown, there is some evidence of the genetic etiology of gastroschisis. Recently, a functionally null deletion of the mouse bone morphogenic protein-1 (BMP-1) gene resulted in a phenotype that resembled a human neonate with gastroschisis. BMP-1 thus became the first potential candidate gene for gastroschisis. METHODS: To explore this possibility the authors collected blood samples from 11 patients who had gastroschisis. Mutational analysis of exons 2 to 15 of the human BMP-1 gene was performed using genomic polymerase chain reaction, single-strand conformation polymorphism analysis and direct sequencing methods. RESULTS: No mutation of the human BMP-1 gene was observed in any of these patients. CONCLUSION: Although heterogeneous etiologies might be proposed for gastroschisis, our results provide further evidence of a nongenetic etiology for gastroschisis. J Pediatr Surg 36:885-887.

Bone Morphogenetic Protein 1↗
PubMed2001

Repetitive administration of tetrabenazine induces irreversible changes in locomotion and morphology of the substantia nigra in rats.

We investigated the effects of a 7 day repetitive administration of tetrabenazine (TBZ), which depletes monoamines, on both locomotor behavior and histomorphometrial findings of substantia nigra in rats. These results were compared with the effects of a single dose of TBZ, which is a common paradigm in animal models of depression. A single dose of TBZ causes reversible decrease of voluntary movement and no histological changes. In contrast, as for repetitive administration, this experiment demonstrated irreversible and significant decrease in spontaneous locomotion, as well as histological changes in the neurons of the substantia nigra pars compacta. These results have led us to propose that prolonged TBZ administration could provide a novel and useful model for the behavioral characteristics and anatomical pathology of Parkinson's disease as one of the oxidative stress models induced by abnormal dopamine metabolism.

Adrenergic Uptake Inhibitors↗
PubMed2001

Assessment of the morphology and significance of the lymph nodal and hepatic lesions produced in rats by the feeding of certain mineral oils and waxes. Proceedings of a pathology workshop held at the Fraunhofer Institute of Toxicology and Aerosol Research Hannover, Germany, May 7-9, 2001.

A Panel of medical and veterinary pathologists reviewed published and unpublished reports dealing with studies of various white mineral oils and waxes in F344 and Sprague-Dawley rats. They also had available and studied histologic slides from both subchronic and chronic studies of certain mineral hydrocarbons (90-day oral study of low melting point wax (LMPW) in female Fischer 344 and Sprague-Dawley rats; 90-day studies of P15H* and P70H white oil and high melting point wax (HMPW) in male and female F344 rats and 24 month study of P70H white oil in male and female F344 rats. The Panel also reviewed mineral oil-induced alterations in tissues of human patients (liver, hepatic lymph node and spleen). The Panel agreed that certain of the mineral hydrocarbons produced lesions in the mesenteric lymph nodes and liver of the F344 rat and these lesions were best described as microgranulomas/granulomas. The lesions were fundamentally similar in both organs, although varying in severity with dose and type of mineral hydrocarbons. The Panel agreed that hepatic lesions with inflammatory cell infiltration, necrosis, and fibrosis were produced only by feeding of LMPW and the lesions were confined to F344 rats and not found in Sprague-Dawley rats. The most severe granulomatous lesions in the mesenteric lymph nodes were found in high dose LMPW-fed F344 rats. The microgranulomas were similar in subchronic and chronic studies. Also, little difference existed between controls and treated F344 rats in the incidence and severity of the lesions after 2 years of feeding P70H white oil. The Panel agreed that some slight reversibility existed for these lesions, but also agreed that complete resolution was unlikely as regression of the lesions in the rat would likely be slow. The Panel agreed that a minimal severity infiltrate of mononuclear inflammatory cells occurred in the base of the mitral valve in a slightly increased incidence in F344 rats fed LMPW. The Panel concluded that these mitral valve alterations had little if any toxicologic significance as the focal infiltrate was minimal in severity, occurred in controls, occurred in association with murine cardiomyopathy, and were unlike the responses in the liver and mesenteric lymph nodes. The Panel agreed that the lesions observed in the liver and mesenteric lymph nodes of F344 rats exposed to MHCs, especially the LMPW, were different morphologically from changes observed in lymph node, liver, and spleen of humans that were mineral oil-users. These changes in humans are usually found incidentally in tissues taken at biopsy or autopsy. The MHC-induced lesions can be considered incidental and inconsequential in humans.

Animals↗
PubMed2001

Gender difference in the relationships among hyperleptinemia, hyperinsulinemia, and hypertension.

Studies reveals that plasma leptin levels (LEP) in females are higher than those in males, and that LEP in hypertensive subjects are higher than those in BMI-matched normotensive subjects. To investigate the relationships among LEP, blood pressure (BP) and insulin sensitivity, we studied these relationships in 133 Japanese males and 263 females. LEP were positively correlated with BP, body mass index, body fat mass (FM) and homeostasis model assessment (HOMA). Regression analysis in which age and FM were adjusted showed LEP were associated with BP and HOMA. Even with adjustment by age, FM and HOMA, LEP were still positively correlated BP in males. LEP in insulin-resistant hypertensives was significantly higher than those in insulin-sensitive hypertensives, in insulin-sensitive normotensives and in insulin-resistant normotensives in males. However, in females, a significantly higher LEP was observed in insulin-resistant subjects than in insulin-sensitive subjects regardless of hypertension. These data suggest that it would be sexual difference in the relationships among hyperleptinemia, hyperinsulinemia and hypertension.

Adult↗
PubMed2001

Developmental analysis of a putative ATP/ADP carrier protein localized on glyoxysomal membranes during the peroxisome transition in pumpkin cotyledons.

In order to clarify the peroxisomal membrane proteins (PMPs), we characterized one of the major PMPs, PMP38. The deduced amino acid sequence for its cDNA in Arabidopsis thaliana contained polypeptides with 331 amino acids and had high similarity with those of Homo sapiens PMP34 and Candida boidinii PMP47 known as homologues of mitochondrial ATP/ADP carrier protein. We expected PMP38 to be localized on peroxisomal membranes, because it had the membrane peroxisomal targeting signal. Cell fractionation and immunocytochemical analysis using pumpkin cotyledons revealed that PMP38 is localized on peroxisomal membranes as an integral membrane protein. The amount of PMP38 in pumpkin cotyledons increased and reached the maximum protein level after 6 d in the dark but decreased thereafter. Illumination of the seedlings caused a significant decrease in the amount of the protein. These results clearly showed that the membrane protein PMP38 in glyoxysomes changes dramatically during the transformation of glyoxysomes to leaf peroxisomes, as do the other glyoxysomal enzymes, especially enzymes of the fatty acid beta-oxidation cycle, that are localized in the matrix of glyoxysomes.

Amino Acid Sequence↗
PubMed2001

A proteinase-storing body that prepares for cell death or stresses in the epidermal cells of Arabidopsis.

Plants degrade cellular materials during senescence and under various stresses. We report that the precursors of two stress-inducible cysteine proteinases, RD21 and a vacuolar processing enzyme (VPE), are specifically accumulated in approximately 0.5 microm diameter x approximately 5 microm long bodies in Arabidopsis thaliana. Such bodies have previously been observed in Arabidopsis but their function was not known. They are surrounded with ribosomes and thus are assumed to be directly derived from the endoplasmic reticulum (ER). Therefore, we propose to call them the ER bodies. The ER bodies are observed specifically in the epidermal cells of healthy seedlings. These cells are easily wounded and stressed by the external environment. When the seedlings are stressed with a concentrated salt solution, leading to death of the epidermal cells, the ER bodies start to fuse with each other and with the vacuoles, thereby mediating the delivery of the precursors directly to the vacuoles. This regulated, direct pathway differs from the usual case in which proteinases are transported constitutively from the ER to the Golgi complex and then to vacuoles, with intervention of vesicle-transport machinery, such as a vacuolar-sorting receptor or a syntaxin of the SNARE family. Thus, the ER bodies appear to be a novel proteinase-storing system that assists in cell death under stressed conditions.

Adaptation, Physiological↗