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Biomedical subjects

Yuichiro Yamashiro

Publications and source records attributed to Yuichiro Yamashiro.

At least 55 records · Page 3Linked to original sources
PubMed2004

A rare case of bilateral stage IV adrenal neuroblastoma with multiple skin metastases in a neonate: diagnosis, management, and outcome.

A neonate with stage IV bilateral adrenal neuroblastoma associated with metastases to the skin, liver, bone marrow, and right ocular conjunctiva is reported. At birth, skin metastases were present all over the body. He underwent a combination of chemotherapy, surgery, and peripheral blood stem cell transplantation (PBSCT). Histopathology was unfavorable with diploid tumor cell DNA content and low levels of TRK-A mRNA expression. Skin and conjunctival metastases disappeared after PBSCT, and there have been no signs of recurrence after 5 years of follow-up. Accurate staging of disease and histologic examination followed by intensive management are essential even in infants with neuroblastoma to ensure successful outcome.

Adrenal Gland Neoplasms↗
PubMed2004

Histological findings after angioplasty using conventional balloon, radiofrequency thermal balloon, and stent for experimental aortic coarctation.

BACKGROUND: Use of balloon angioplasty or stent implantation has been reported to be effective in relieving coarctation of the aorta. However, restenosis frequently occurs after balloon angioplasty for native aortic coarctation in small infants, and sometimes develops after stent implantation because of vessel growth. The causes of restenosis remain uncertain. The purpose of this study was to assess the histologic differences in vascular responses to angioplasty using conventional balloon, radiofrequency thermal balloon (RFTB), or stent for experimental aortic coarctation. METHODS: The authors surgically created an aortic coarctation model using 14 puppies. Angioplasty using conventional balloon, RFTB, or stent was performed 1 month after the initial operation. At the acute or chronic phase after angioplasty, the animals were killed and histologic studies were performed. RESULTS: More vascular injuries were noted in the specimens from animals undergoing conventional angioplasty than in those with RFTB or stent. However, neointimal hyperplasia was seen more often after RFTB or stent because of the proliferation of smooth muscle cells from the tunica media, caused by secretion of growth factors. Apoptosis reached a peak 1-2 weeks after angioplasty, regardless of the type of intervention. CONCLUSIONS: The authors conclude that angioplasty with RFTB or stent can provide relatively small injuries in the vessel wall for aortic coarctation, but care must be taken to prevent restenosis caused by intimal hyperplasia, because neointima hyperplasia is more frequent after RFTB or stent.

Angioplasty, Balloon↗
PubMed2004

Effects of bifidobacterium breve supplementation on intestinal flora of low birth weight infants.

BACKGROUND: It is known that the bifidobacteria flora play important roles in mucosal host defense and can prevent infectious diseases. Because bacterial populations develop during the first day of life, the authors examined whether the early administration of bifidobacteria has a positive effect on the health of low birth weight infants. METHODS: The effects of oral administration of Bifidobacterium breve (B. breve) supplements were studied in a controlled trial with low birth weight infants (average birth weight 1489 g). The infants were divided into three groups: Group A and B received a dose of 1.6 x 10(8) cells of B. breve supplement twice a day, commencing either from several hours after birth (group A) or 24 h after birth (group B). Group C, the control group, received no supplement. RESULTS: There were no significant differences in birth weight, treatment with antibiotics, and the starting time of breast-feeding among the three groups. A Bifidobacterium-predominant flora was formed at an average of 2 weeks after birth in group A and at an average of 4 weeks after birth in group B, while no Bifidobacterium was isolated in eight out of 10 infants in group C during the observation period of 7 weeks. In comparison between group A and B, Bifidobacterium was detected significantly earlier in group A, and the number of Enterobacteriaceae present in the infants at 2 weeks after birth was significantly lower in group A. CONCLUSION: The results of the present study suggest that very early administration of B. breve to low birth weight infants is useful in promoting the colonization of the Bifidobacterium and the formation of a normal intestinal flora.

Administration, Oral↗
PubMed2004

Smad3 deficiency attenuates renal fibrosis, inflammation,and apoptosis after unilateral ureteral obstruction.

BACKGROUND: Transforming growth factor-beta (TGF-beta) has been implicated in the development of renal fibrosis induced by unilateral ureteral obstruction (UUO). However, there is little information on signaling pathways mediating TGF-beta activity involved in molecular and cellular events leading to renal fibrosis induced by UUO. In this study, we sought to determine whether Smad3, a major signaling component of TGF-beta, mediated renal fibrosis induced by UUO. METHODS: Renal fibrosis, inflammation, and apoptosis induced by UUO were macroscopically and histologically compared between wild-type mice and Smad3 null mice. RESULTS: Gross appearance of the kidney after UUO showed relatively intact kidney in Smad3 null mice [Smad3(-/-) mice] when compared with that of wild-type mice [Smad3(+/+) mice]. Renal interstitial fibrosis based on the interstitial area stained with Aniline-blue or Sirius red solution was significantly attenuated in the obstructed kidney of Smad3(-/-) mice when compared with that of Smad3(+/+) mice. Deposition of type I and type III collagens were also significantly reduced in the obstructed kidney of Smad3(-/-) mice. In addition, the numbers of myofibroblasts, macrophages, and CD4/CD8 T cells infiltrated into the kidney after UUO were significantly attenuated in the obstructed kidney of Smad3(-/-) mice when compared with that of Smad3(+/+) mice. Furthermore, terminal deoxynucleotidyltransferase-mediated deoxyuridine triphosphate (dUTP) nick-end labeling (TUNEL) staining after UUO showed significantly reduced number of tubular apoptotic cells in the obstructed kidney of Smad3(-/-) mice when compared with that of Smad3(+/+) mice. Endogenous Smad pathway was activated in the obstructed kidney after UUO in wild-type mice as judged by the increase of phosphorylated Smad2 or phosphorylated Smad2/3-positive cells in renal interstitial area. CONCLUSION: Smad3 deficiency attenuated renal fibrosis, inflammation, and apoptosis after UUO, suggesting that Smad3 was a key molecule mediating TGF-beta activity leading to real fibrosis after UUO.

Animals↗
PubMed2003

Anomalous pancreatic duct anatomy, ectopic distal location of the papilla of Vater and congenital biliary dilatation: a new developmental triad?

BACKGROUND: The opening of the papilla of Vater represents the orifice of the embryonic hepatic diverticulum from which the ventral pancreas, common bile duct, and liver are derived. Recently, we found a strong association between congenital biliary dilatation (CBD), certain types of pancreatic ductal anatomy (PDA), and ectopic distal location of the papilla of Vater which prompted us to study the relationship between the location of the papilla of Vater and abnormal PDA. METHODS: A total of 118 patients with CBD were studied. Cholangiograms documented the presence of pancreaticobiliary malunion (PBMU), the location of the papilla of Vater, and the PDA. Eleven age-matched patients with intermittent jaundice were used as controls. RESULTS: In the control group, the papilla of Vater was located normally in the descending portion of the duodenum in all cases. In the 118 CBD patients, the papilla of Vater was located normally in 38 (32.2%), but in 80 (67.8%), the papilla was located distal to the descending portion of the duodenum. When the papilla was located distally, the incidences of the specific types of PDA studied were significantly higher than when the papilla was located normally (p<0.01). Pancreatic duct dilatation was also more frequent if the papilla was located distally (28.7%) compared with CBD patients with a normal papilla (7.9%) or normal controls (0%) (both p<0.01). PBMU was present in all CBD patients and absent in all controls. CONCLUSION: Our study strongly suggests that abnormalities occurring during early embryological development of the hepatic diverticulum are responsible for the association between abnormal PDA and ectopic distal location of the papilla of Vater in CBD.

Adolescent↗
PubMed2003

Antibiotic prophylaxis by low-dose cefaclor in children with vesicoureteral reflux.

Sulfamethoxazole/trimethoprim (SMX/TMP) and nitrofurantoin are the most frequently used agents for prophylaxis to reduce the risk of recurrent urinary tract infections (UTIs) in children with vesicoureteral reflux (VUR). Nitrofurantoin, however, is not available in Japan and increasing resistance of organisms to SMX/TMP has recently raised doubts about its effectiveness as a prophylactic agent. This study was conducted to investigate whether antibiotic prophylaxis using low-dose cefaclor can effectively reduce the risk of recurrent UTIs. Thirty-nine children (31 male, 8 female) with primary VUR were enrolled. Ages varied from 0.5 to 111 months (mean 10.6 months). A prophylactic dose of 5-10 mg cefaclor per kg per day was given 1-3 times daily depending on the patient's age. Mean duration of prophylactic treatment was 15.5 months. Eleven children (ten male, one female) developed breakthrough UTIs during a total of 606 months treatment (or about one further infection in 55 months). Resistance to cefaclor was noted in three organisms: Enterococcus spp., Morganella spp., and Pseudomonas spp. Evidence of antibacterial activity was present in the morning urine samples from all of seven children tested. Cefaclor was well accepted and tolerated by all subjects. None withdrew from the study because of side effects. These results suggest that cefaclor can be an alternative choice for prophylactic treatment because of its safety, good compliance and low rates of resistant Escherichia coli.

Anti-Bacterial Agents↗
PubMed2003

Effect of human breast milk on urinary 8-hydroxy-2'-deoxyguanosine excretion in infants.

During the perinatal period, oxidative stress is intimately involved in pathologic processes of serious diseases. Although breast milk contains many antioxidants, it is not clear whether breast milk can act as an antioxidant in infants in vivo. We compared the oxidative stress levels in total of 41 healthy 1-mo-old infants by measuring urinary 8-hydroxy-2'-deoxyguanosine, which is one of the biomarkers of oxidative DNA damage. These infants were divided into four groups according to the type of feeding. Urinary 8-hydroxy-2'-deoxyguanosine excretion of the breast-fed group was significantly lower than those of the artificial milk dominant mixed-fed group or the bottle-fed group. Our data suggest that breast milk, not artificial formula, acts as an antioxidant during infancy.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2003

Nephrotic syndrome associated with human parvovirus B19 infection.

A previously healthy 8-year-old Japanese boy developed nephrotic syndrome during the course of erythema infectiosum due to human parvovirus B19 (PVB19) infection. A renal biopsy showed mesangiocapillary proliferative glomerulonephritis with immune complex deposits associated with PVB19 virus. His renal involvement improved spontaneously.

Biopsy↗
PubMed2003

Effects of dietary sphingomyelin on central nervous system myelination in developing rats.

Human milk contains sphingomyelin (SM) as a major component of the phospholipid fraction. Galactosylceramide (cerebroside), a metabolite of sphingolipids, increases along with CNS myelination, and is generally considered a universal marker of myelination in all vertebrates. l-Cycloserine (LCS) is an inhibitor of serine palmitoyltransferase (SPT), a rate-limiting enzyme for sphingolipid biosynthesis that is reported to show increased activity with development of the rat CNS. The present study examined the effects of dietary SM on CNS myelination during development in LCS-treated rats. From 8 d after birth, Wistar rat pups received a daily s.c. injection (100 mg/kg) of LCS. From 17 d after birth, the animals were fed an 810 mg/100g of bovine SM-supplemented diet (SM-LCS group) or a nonsupplemented diet (LCS group). At 28 d after birth, the animals were killed and subjected to biochemical and morphometric analyses. The myelin dry weight, myelin total lipid content, and cerebroside content were significantly lower in the SM-LCS and LCS groups than in a group not treated with LCS (the non-LCS group). However, these levels were significantly higher in the SM-LCS group than in the LCS group. Morphometric analysis of the optic nerve revealed that the axon diameter, nerve fiber diameter, myelin thickness, and g value (used to compare the relative thickness of myelin sheaths around fibers of different diameter) were significantly lower in the LCS group than in the other groups, but were similar in the SM-LCS and non-LCS groups. These findings suggest that dietary SM contributes to CNS myelination in developing rats with experimental inhibition of SPT activity corrected].

Acyltransferases↗
PubMed2003

Resting energy expenditure and plasma leptin levels in adolescent girls with anorexia nervosa.

OBJECTIVE: Our aim was to examine the relationship between resting energy expenditure (REE) and circulating leptin levels during long-term refeeding in adolescent girls with anorexia nervosa (AN). METHOD: We measured REE, the plasma leptin level, the free T(3) level, body surface area (BSA), and dietary energy intake in AN adolescents before and 8 weeks after refeeding therapy. RESULTS: All parameters in AN subjects before the refeeding therapy were significantly lower than those in AN subjects after the therapy and in the controls. There were no significant differences in REE and BSA between posttherapy AN subjects and controls, but plasma leptin levels in the posttherapy AN subjects were still significantly lower than those in the controls. Significant correlations between REE and BSA were detected in the AN subjects both before and after the refeeding therapy, but REE did not correlate significantly with plasma leptin level in either of the AN groups. DISCUSSION: Our results suggest that the REE in AN subjects after long-term refeeding therapy is not associated with the changes in plasma leptin levels but with BSA.

Adolescent↗
PubMed2003

The relationship between the concentration of dextran sodium sulfate and the degree of induced experimental colitis in weanling rats.

BACKGROUND: Although a dextran sodium sulfate (DSS)-induced colitis is commonly used as an ulcerative colitis (UC) model in adult rodents, there are no studies using this model in young animals. We examined differences in the severity of DSS-induced colitis as a function of the concentration of DSS administered and sought to establish a DSS-induced colitis model in young rats. METHODS: We administrated different concentrations of DSS solution (2%, 3%, and 4%) to 4-week-old weanling rats and compared their clinical findings, colonic histologic findings, mucosal leukotriene B4 (LTB4) production, and mucosal blood flow with control weanling rats and 8-week-old adult rats given 4% DSS for induced colitis. RESULTS: Clinical symptoms, such as diarrhea and rectal bleeding, histologic findings, and disturbance of mucosal microcirculation in weanling rats given 4% DSS were significantly more severe than those in adult rats given the same treatment. Three of 10 rats given 2% DSS had no bloody stool and 2 of 10 rats given 4% DSS died during the experimental periods. Clinical symptoms, hemoglobin levels, histologic damage scores, mucosal LTB4 production, and mucosal blood flow became more severely deranged as the concentration of DSS increased from 2% to 4%. CONCLUSION: These findings suggest that we can adjust disease severity in UC model for young children by giving different concentrations of DSS to weanling rats.

Aging↗
PubMed2003

Fecal alpha1-antitrypsin concentrations as a measure of enteric protein loss after modified fontan operations.

BACKGROUND: Little is known about the enteric protein loss in patients after a modified Fontan operation before the appearance of overt symptoms or signs of protein-losing enteropathy (PLE). The authors examined the possibility of using fecal alpha1-antitrypsin concentration measurements for the early detection of postoperative PLE and in longer term postoperative monitoring of these patients. METHODS: The authors compared fecal alpha1-antitrypsin concentrations in stool samples from 12 children 12.0 to 43.7 months after modified Fontan operations with those of 12 age-matched control subjects and examined the relationship between the alpha1-antitrypsin levels and time since operation. The authors also compared fecal alpha1-antitrypsin concentrations of stools from the same patients obtained at two different time points after surgery with intervals between samples ranging from 14.7 to 19.8 months. RESULTS: No significant differences in serum total protein and albumin levels were observed between patients after the modified Fontan operation and control subjects. The fecal concentrations of alpha1-antitrypsin in patients after the Fontan operation were significantly (P < 0.01) higher than those in control subjects. There was no significant correlation between fecal alpha1-antitrypsin concentrations and time elapsed after the Fontan operation. The fecal alpha1-antitrypsin concentration increased significantly (P < 0.01) over periods of 14.7 to 19.8 months after the first measurement. CONCLUSION: The results show that enteric protein loss begins before the appearance of hypoproteinemia in patients after a modified Fontan operation, and that the measurement of fecal alpha1-antitrypsin concentrations in random stool samples is useful as an early indicator. To watch for the development of PLE after Fontan operation, it may be important to perform longitudinal follow-up examinations of enteric protein loss by measuring fecal alpha1-antitrypsin concentrations early in the postoperative period.

Blood Proteins↗
PubMed2003

Effects of highly purified eicosapentaenoic acid on erythrocyte fatty acid composition and leukocyte and colonic mucosa leukotriene B4 production in children with ulcerative colitis.

BACKGROUND: n-3 Polyunsaturated fatty acids (PUFAs) have been suggested as a treatment for ulcerative colitis (UC). However, the efficacy of n-3 PUFAs against UC has not been examined in children. Therefore, the authors investigated the effects of eicosapentaenoic acid (EPA) on fatty acid composition and leukotriene (LT) production in children with UC. METHODS: For 2 months the authors administered highly purified EPA ethyl ester (EPA-E) (1.8 g/d) to children with UC in remission. Colonic mucosal histology, fatty acid composition of erythrocyte membrane phospholipids, and LTB4 production by leukocytes and colonic mucosa were measured before and 2 months after the initiation of EPA-E treatment. RESULTS: No patients relapsed during the study period, and no significant differences were detected in laboratory findings obtained before and 2 months after the initiation of EPA-E ingestion. There were no significant differences in mucosal histologic scores before and 2 months after EPA-E treatment. The EPA levels in erythrocyte membranes 2 months after the initiation of EPA-E treatment were significantly higher than before treatment, but the other fatty acids showed no significant changes. LTB4 production by leukocytes and rectal mucosa after 2 months of EPA-E treatment was significantly lower than before treatment. CONCLUSION: EPA-E treatment increased the levels of EPA in erythrocytes and decreased LTB4 levels produced by leukocytes and colonic mucosa. To assess the concomitant clinical changes, we should examine the long-term effects of EPA-E ingestion on the maintenance of remission in children with UC.

Adolescent↗