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Biomedical subjects

H Kobayashi

Publications and source records attributed to H Kobayashi.

At least 199 records · Page 11Linked to original sources
PubMed2001

Eruption disturbances of mandibular permanent canines in Japanese children.

OBJECTIVES: The purpose of this study was to clarify the cause and prognosis of eruption disturbance of mandibular permanent canines. SAMPLE AND METHODS: Fifteen Japanese children who visited Niigata University Dental Hospital between 1979 and 1997 with unerupted and/or impacted mandibular permanent canines were examined. RESULTS: All cases showed unilateral disturbances. The eruption disturbance of 6 mandibular canines was associated with a calcified obstacle such as an odontoma (5 cases) or a supernumerary tooth (1 case). After removal of the obstacle, 5 canines were aligned within the dentition. Out of 10 cases, where the permanent canine germ showed malpositioning or aberrant eruption path, 5 primary predecessors had undergone endodontic treatment. In these 10 cases, 6 canines erupted after treatment, two were extracted and the remaining two were left in their impacted position. CONCLUSIONS: The present results suggest that it is relatively easy for the position of unerupted mandibular canines associated with calcified obstacles to be improved by removal of the obstacle, but that it is more difficult for teeth showing anomaly in the position of the canine germ to be aligned within the dentition.

Adolescent↗
PubMed2001

Idiopathic sustained left ventricular tachycardia in pediatric patients.

BACKGROUND: Idiopathic sustained ventricular tachycardia originating from the left ventricle (ILVT) has been an indication for catheter ablation. The present study evaluated the clinical features, long-term prognosis and indications for treatment in pediatric patients with ILVT. METHODS: The subjects of the present study were eight patients (four males and four females) with a mean age at onset of 11.0 years (range 3-15 years). The mean follow-up period was 7.7 years (range 2.1-11.3 years). RESULTS: In electrophysiologic studies, intravenously administered verapamil was effective for the termination of tachycardia in all six patients who received this treatment and for the prevention of tachycardia in four of five patients. Oral administration of verapamil was effective in five of seven patients. Propranolol or flecainide was added to the treatment protocol for two patients who did not respond to verapamil alone. Tachycardia disappeared without drugs in four patients during the follow-up period and became non-sustained in another patient. Two of three patients with persistent tachycardia underwent catheter ablation. Pharmacologic treatment was very effective for ILVT among these patients. CONCLUSIONS: Pharmacologic therapy, such as with verapamil, is still the treatment of choice for ILVT because of a good long-term prognosis and potential risks and complications by manipulation of catheter ablation.

Adolescent↗
PubMed2001

Early intervention for infants with autistic spectrum disorders in Japan.

BACKGROUND: To date, many researchers in Japan have assumed that the cause of autistic spectrum disorders is attributable to some disorder in the ability of the child. However, we have been working on the premise that autistic spectrum disorders are brought about by relationship disturbances in early infancy and have been attempting to validate this hypothesis through early intervention. METHODS: We have examined the developmental process of affective communication in infants with autistic spectrum disorders. We have postulated that approach-avoidance motivational conflict (Richer) is the primary factor impeding the development of affective communication and have focused therapeutic intervention on this perspective. RESULTS: As a result, attachment behavior was markedly improved in children, but affective communication with their mothers was not. Examing the mothers' images of themselves in infancy in mother-infant psychotherapy, problems that the mothers had themselves in infacy with attachment behavior to their own mothers affected the mothers' internal representation of their children, leading to active evolution of mother-child interaction and development of affective communication between the mother and child. CONCLUSIONS: In this context, the basis and significance of the internal representation of both parties being determinants in the quality of mother-child communication are discussed. Our goal in early intervention is not the elevation of a child's linguistic-cognitive abilities, but the creation of a comforting relationship in which both parent and child can live securely, without strain.

Autistic Disorder↗
PubMed2001

A case of biliary atresia with duplication of the common bile duct.

The authors report a case of biliary atresia (BA) with duplication of the common bile duct. A 1-month-old girl was referred for investigation of persistent jaundice. BA was suspected and confirmed with intraoperative cholangiography. A portoenterostomy was performed at 50 days of age. During dissection of the fibrous remnant of the common bile duct, a separate fibrous bile duct remnant running in parallel on the left, was identified. Histologically, there was bile duct proliferation at the porta hepatis of the left bile duct remnant. A diagnosis of BA with duplicated common bile duct was made. Postoperative course was uneventful, and at a follow-up assessment at 7 months, she was jaundice free, and her progress has been unremarkable.

Biliary Atresia↗
PubMed2001

Transplantation of newborn esophagus: an experimental study.

PURPOSE: The aim of this study was to see if allogeneic transplantation (Tx) of newborn esophagus can create viable esophageal tissue that may be used for treating long gap esophageal atresia. METHODS: Specimens of thoracic esophagus from newborn Brown-Norway rats, each were transplanted into a pouch created in the distal omentum of 5-week-old Lewis rats. In group I no immunosuppressant was used. FK-506 was used in group II (0.2 mg/kg), group III (0.6 mg/kg), and group IV (1.2 mg/kg) until a predetermined day of graft harvesting (1, 2, 3, 4, 5, 6, and 8 weeks after Tx). FK-506 was used for only 2 weeks in group V (0.6 mg/kg), and group VI (1.2mg/kg), and transplanted esophageal grafts were harvested 1, 2, 3, and 4 weeks after cessation of 2 weeks course FK-506. Syngeneic esophagus transplants were used as controls. All grafts were examined by H&E staining to assess graft viability and degree of rejection. RESULTS: Each successfully transplanted esophagus appeared macroscopically as a tube like mass. Each graft could be mobilized to the thoracic cavity, because of the long omental pedicle. Graft survival in the control group was 100%. Rejection was observed in all grafts from groups I, II, V, and VI. In contrast, grafts from groups III and IV showed only minimal or no rejection. There was no evidence of side effects of FK-506 in rats in groups III and IV, except significantly slower weight gain compared with controls (P <.05). CONCLUSIONS: FK-506 successfully prevented rejection, although immunologic tolerance was not achieved. These observations suggest that the authors' procedure has the potential to produce viable esophageal tissue that could be a new option for treating long gap esophageal atresia.

Animals↗
PubMed2001

Pyloric stenosis: new histopathologic perspective using confocal laser scanning.

BACKGROUND/PURPOSE: Idiopathic hypertrophic pyloric stenosis (IHPS) is a common infantile disorder characterized by enlargement of the pylorus and gastric outlet obstruction. Its complete etiology is still not fully understood, but recent research has focussed on abnormalities of nerve distribution. The authors used confocal laser scanning microscopy to perform 3-dimensional studies of pylorus biopsy specimens taken from cases of IHPS and present their findings. METHODS: Pylorus biopsy specimens obtained at pyloromyotomy from 6 infants with IHPS were studied using confocal microscopy and compared with 6 control pylorus biopsy specimens from patients without gastrointestinal disease. Biopsy specimens were pretreated to enhance nerve expression by using protein gene product 9.5 (PGP9.5) polyclonal antibody to identify enteric nerve system fibers. Double staining immunofluorescence was used to detect alpha smooth muscle actin (SMA), a smooth muscle marker. RESULTS: Control pylorus biopsy specimens showed many thin PGP9.5-positive nerve fibers in the circular and longitudinal muscle layers that communicated with each other to create a 3-dimensional meshlike network. Muscle cells stained by alpha SMA antibody were thin. In contrast, muscle cells from IHPS patients were fat and round. The PGP9.5 staining nerve fibers from IHPS patients formed numerous, thick, and contorted bundles that did not communicate. CONCLUSIONS: By using confocal laser microscopy the authors were able to identify abnormally thick contorted nerve bundles in the pyloric muscle layers of infants with IHPS. These anormal nerve bundles have not been described previously because of the limitations of 2-dimensional microscopy. The authors suspect that the etiology of IHPS may be related to these abnormal fibers.

Biopsy, Needle↗
PubMed2001

Intestinal neuronal dysplasia-like pathology in Ncx/Hox11L.1 gene-deficient mice.

BACKGROUND/PURPOSE: Ncx/Hox11L.1-deficient (Ncx-/-) mice specifically created by the authors had mega-ileo-ceco-colon (mega-ICC) with a caliber change in the proximal colon. The authors studied the nerve distribution in the bowel of these Ncx-/- mice to determine the cause of their bowel dysmotility. METHODS: Four-week-old Ncx-/- mice (n = 10; 5 with mega-ICC, 5 without mega-ICC) were killed and the bowel harvested. Half of each specimen was snap frozen for AchE and NADPH-diaphorase histochemistry, and the other half were fixed with 10% formalin for H&E staining and immunohistochemistry using PGP9.5 antibody (a marker for neurons), C-kit antibody (a marker for intestinal pacemaker cells), and stem cell factor antibody (a marker for C-kit ligand). Age-matched wild-type normal mice (n = 5) served as controls. RESULTS: In the ileum, cecum, and proximal colon from all Ncx-/- mice (irrespective of the association of mega-ICC), typical findings of human intestinal neuronal dysplasia (IND) ie, obvious hyperganglionosis in neuronal plexuses on PGP9.5 immunohistochemistry, ectopic ganglia in the mucosal and muscular layers on AchE histochemistry, and ghostlike ganglia on NADPH-diaphorase histochemistry were found. Likewise, in normal caliber distal colon from these mice, the distribution of ganglion cells, C-kit, and stem cell factor was normal. In control specimens, there was no ectopic ganglia or hyperganglionosis. CONCLUSIONS: These findings suggest that the Ncx/Hox11L.1 gene is required for the proper innervation of the enteric nervous system in mice, and our deficient strain may be useful as a model for studying IND in humans.

Animals↗
PubMed2001

Serum concentration of adhesion molecules in postoperative biliary atresia patients: relationship to disease activity and cirrhosis.

BACKGROUND/PURPOSE: Biliary atresia (BA) is associated with progressive liver fibrosis, which may be mediated by immunologic abnormalities involving adhesion molecules. This study investigates the relationship between serum intercellular adhesion molecule-1 (sICAM-1), serum vascular cell adhesion molecule-1 (sVCAM-1), and the clinical and histologic severity of BA. METHODS: Serum ICAM-1 and VCAM-1 levels were measured by enzyme-linked immunosorbent assay in 35 patients with BA and 20 healthy controls. Standard liver function tests (LFTs), and frozen section liver biopsy specimens were used to determine liver status. On the basis of LFT results, the BA patients were classified into group I (n = 10; normal LFTs), group II (n = 15; elevated LFTs, anicteric), and group III (n = 10; elevated LFTs, icteric). Eight subjects in group II, and all subjects in group III had portal hypertension (PH). RESULTS: sICAM-1 levels were significantly elevated in group III (1760.0 +/- 717.5 ng/mL) compared with group II (555.1 +/- 199.4 ng/mL), group I (272.1 +/- 59.9 ng/mL) and controls (256.3 +/- 71.6 ng/mL). Although sVCAM-1 levels were significantly elevated in group III (1932.9 +/- 282.6 ng/mL) compared with group II (1054.3 +/- 297.0 ng/mL), group I (605.4 +/- 112.4 ng/mL), and controls (616.0 +/- 112.0 ng/mL; P <.001), there was no statistically significant difference between groups I, II, or controls. sVCAM-1 levels were elevated significantly in BA subjects in group II with PH (1253.0 +/- 245.1 ng/mL) compared with those who did not have PH (827.3 +/- 151.7 ng/mL; P <.01). PH did not affect sICAM-1 levels. There was strong expression of ICAM-1 and VCAM-1 in proliferating bile ductules, endothelial cells, and liver cells in group III compared with group II and controls. CONCLUSIONS: In BA, sICAM-1 and sVCAM-1 levels could be useful as markers of end-stage liver disease, with sVCAM-1 being more specific for PH. Induction of ICAM-1 and VCAM-1 may be an important factor in the development of cirrhosis.

Adolescent↗
PubMed2001

Semiquantitative polymerase chain reaction in RNase-producing tissues: Analysis of the developing pancreas.

BACKGROUND/PURPOSE: Many studies in pediatric surgical research use a quantitative analysis of gene expression in microscopic quantities of tissue. The authors describe an analysis of the beta-tubulin mRNA content of the embryonic pancreas, which contains abundant endogenous RNases. A detailed analysis of this RNase-containing system will provide a good template for analysis of other potentially simpler systems. METHODS: Embryonic mouse pancreases were harvested at serial gestational ages. DAPI nuclear staining allowed for counting of cells. cDNA was amplified using a fluoresceinated primer and the normalized fluorescence determined. Known numbers of molecules were amplified in parallel as a standard control. RESULTS: The number of cells increased from 38,000 to 2,700,000 between embryonic day 10.5 (E10.5) and E18.5. mRNA for beta-tubulin did not increase proportionately. Assuming a yield of 100% at E10.5 when no RNases are present, the yield of expected mRNA was 65.3% at E12.5, 13.8% at E15.5, and 0.9% at E18.5, presumably because of the appearance of RNases. CONCLUSIONS: Several parameters must be considered in performing semiquantitative reverse transcription polymerase chain reaction: (1) the yield of RNA based on the projected amount of mRNA, (2) the number of cells in the tissue, and (3) a known number of template molecules amplified in parallel.

Animals↗
PubMed2001

Laparoscopic muscle electrostimulation during laparoscopy-assisted anorectal pull-through for high imperforate anus.

PURPOSE: Our technique for laparoscopic muscle electrostimulation during laparoscopy-assisted anorectal pull-through (LAARPT) for high imperforate anus (HIA) in 3 patients is described. METHODS: The distal rectum and rectourethral fistula is dissected laparoscopically. A muscle stimulator is passed through one of the trocars and used to identify the center of contraction of the levator ani. The same muscle stimulator is used to identify the center of the external sphincter muscle transcutaneously. An intravenous cannulation device (SURFLO Flash IV catheter, TERUMO, CO, Yamanashi, Japan) is inserted through this proposed anus and observed piercing the center of the levator ani. A guide wire is passed through the SURFLO, and a series of dilators are passed along it to create a canal for the colonic pull-through. An anoplasty then was performed. RESULTS: Our technique was successful in all patients. Laparoscopic electrostimulation produced good levator ani contraction in patients I and II and weak contraction in patient III. Patients I and II have symmetrical anal contraction during rectal examination, but patient III has poor contraction. Stool frequency is decreasing in all. CONCLUSION: Direct laparoscopic observation of levator ani contraction allows intraoperative assessment of functional contractility and assists in the accurate placement of the colonic pull-through.

Anal Canal↗
PubMed2001

The 'superficial' peroneal artery: a variation in cutaneous branching from the peroneal artery, nourishing the distal third of the leg.

Two different vascular patterns were encountered in cutaneous branches from the peroneal artery to the posterolateral aspect of the distal third of the leg in 22 flaps from 22 patients who underwent cutaneous or osteocutaneous peroneal flap surgery. In the type 1 vascular pattern, a branch from the peroneal artery, named the 'superficial peroneal artery', nourished the posterolateral aspect of the leg by splitting into several septocutaneous branches. In the type 2 pattern a few septocutaneous branches originated directly from the main peroneal artery and nourished the same area as that fed by the type 1 branch. The type 1 vascular pattern has not been reported to date but was seen in nine out of the 22 consecutive peroneal flaps. The superficial peroneal artery, with its considerable vascular diameter, may serve as a recipient vessel for free flaps or may serve as a donor nutrient vessel for a cutaneous flap, which can be transferred without sacrificing the main peroneal artery. Awareness of these two vascular patterns in the distal third of the leg should also help to reduce the small percentage of skin-flap failures that occur when the cutaneous or osteocutaneous peroneal flap is used.

Adult↗
PubMed2001

Cap polyposis of the colon and rectum: an analysis of endoscopic findings.

BACKGROUND AND STUDY AIMS: Because of the rarity of cap polyposis of the colon and rectum, the endoscopic features of this condition have not been specified to date. The aim of this study is to characterize the endoscopic features of cap polyposis. PATIENTS AND METHODS: The diagnosis of cap polyposis was established by histologic findings in specimens obtained endoscopically or surgically from four patients. Colonoscopic findings in the four patients were retrospectively reviewed. RESULTS: The endoscopic features were divided into semipedunculated type (three patients) and flat-topped protruding type (one patient). In the semipedunculated type, the polyps were characterized by reddish protrusions of various configurations with eroded surface in the rectosigmoid colon. In the remaining patient, all the lesions were flat protrusions with a reddish central depression. The polyps of both types became smaller in size and fewer in number at the proximal part of the sigmoid colon. Multiple white specks were observed in the intervening mucosa in all four patients. CONCLUSIONS: The prominence of the polyps at the distal part of the colon and rectum and multiple white specks in the intervening mucosa seem to be the additional endoscopic features suggestive of cap polyposis.

Adult↗
PubMed2001

Activated protein C prevents development of phosphatidylserine-induced intrauterine growth restriction in mice.

We examined the effect of activated protein C (APC) on the development of intrauterine growth restriction (IUGR) in an experimental animal model we established. The IUGR in mice was induced by artificial phosphatidylserine (PS)/phosphatidylcholine (PC) microvesicles that represent procoagulant phospholipids derived from activated platelets. This model represents the placental insufficiency associated with the phospholipid-induced hypercoagulable state in placental circulation. APC prolonged the activated partial thromboplastin time (aPTT) using mouse plasma and dose dependently inhibited thrombin generation in a chromogenic assay in defibrinated plasma of mice. Administration of exogenous APC at concentrations that maximally inhibited thrombin generation in defibrinated plasma prevented a significant reduction in fetal body weight and induced marked histological changes including congestion and fibrin depositions in IUGR mouse placentas. These results suggest that the inhibition of thrombin generation in the placental circulation by APC prevents the development of IUGR that is dependent on coagulation associated with PS/PC from activated platelets.

Animals↗
PubMed2001

Urinary trypsin inhibitor and biliary atresia--providing protection for the liver?

Urinary Tyrosine Inhibitor (UTI) is produced in the liver and excreted in urine hepatic inflammation, infection or malignancy. We assess the possible implications of UTI in biliary atresia (BA). Liver function was used to divide 34 postoperative BA patients into 2 groups: Group 1 (n=25), anicteric (total bilirubin [T-Bil] <2.0 mg/dl); and Group 2 (n = 9), icteric (total bilirubin >2.0 mg/dl) with abnormal liver function test results, and repeated episodes of cholangitis. 26 age-matched subjects with no history of liver disease acted as controls

Adolescent↗
PubMed2001

Enhanced contact hypersensitivity in human monocyte chemoattractant protein-1 transgenic mouse.

Monocyte chemoattractant protein (MCP)-1 is a chemotactic cytokine for monocytes, memoryT cells and dendritic cells (DC). However, the precise role of MCP-1 in a variety of immunological responses remains unclear. In the present study, we analyzed contact hypersensitivity (CHS) using human MCP-1 transgenic mice (hMCP-1Tgm) that constitutively produce high levels of hMCP-1 in the sera. Following 2,4-dinitrofluorobenzene (DNFB) sensitization, enhancement of CHS was demonstrated in Tgm as compared with that in non-Tgm. Anti-hMCP-1 antibodies significantly inhibited the CHS in Tgm. A prominent accumulation of B7-1+I-Ad+ Langerhans' cells (LC) bearing haptens was detected in draining lymph nodes (DLN) of Tgm 24 h after DNFB or fluorescein isothiocyanate (FITC) sensitization. Similar results were obtained with BALB/c mice administrated recombinant (r) hMCP-1. Langerhans' cells (LC) in the epidermal sheets of Tgm increased in size and expressed high levels of I-Ad and B7-1 12 h after FITC application compared with those of non-Tgm. After 18 h, the number of LC in the epidermis was reduced in Tgm. It was also shown that the B7-1 expression on LC of BALB/c mice was augmented after culture with rhMCP-1. These findings demonstrate that MCP-1 not only accelerates LC migration from epidermis into the DLN after sensitization with haptens but also up-regulates the I-Ad and B7-1 expressions, which results in the enhanced T cell activation and CHS.

Animals↗
PubMed2001

Difference in degree of mucosal atrophy between elevated and depressed types of gastric epithelial tumors.

BACKGROUND: The significance of atrophy in the background mucosa and Helicobacter pylori infection in the morphogenesis of gastric epithelial tumors has not yet been investigated. METHODS: The degree of mucosal atrophy, as determined by a histological analysis and the serum pepsinogen (PG) levels, and H. pylori status were investigated in patients with elevated adenoma (EA group; n = 40), elevated early cancer of intestinal type (ECI group; n = 30), depressed early cancer of intestinal type (DCI group; n = 37) and depressed early cancer of diffuse type (DCD group; n = 33), and the findings were then compared to those in 91 controls. RESULTS: At all sites of the stomach, the histologic score of atrophy was higher in the EA group and in the ECI group than in the controls. In the DCI group, the histologic score of atrophy in the antrum was higher than in the controls, but no such difference in the score was found in the DCD group. The PG I/II ratios in the EA, ECI and DCI groups were significantly lower than in the controls, and the value was also different between the ECI and DCI groups. While H. pylori prevalence was higher in all groups than in the controls, a logistic regression analysis which included the grade of atrophy as a determinant revealed the infection to be an independent associated factor for the DCD group. CONCLUSIONS: The difference in the background mucosal atrophy seems to contribute to different macroscopic types in gastric epithelial tumors. This seems to be the case especially for cancer of intestinal type.

Adenoma↗
PubMed2001

Pharmacokinetics and absolute bioavailability of sitafloxacin, a new fluoroquinolone antibiotic, in healthy male and female Caucasian subjects.

1. The aim was to compare the pharmacokinetics of sitafloxacin from a capsule formulation (dose of 500 mg sitafloxacin) and an intravenous (i.v.) formulation infused over 1 h (dose of 400 mg sitafloxacin) in healthy male and female subjects and to estimate the absolute bioavailability of sitafloxacin from the capsule formulation. 2. Following oral administration, sitafloxacin was rapidly absorbed, with a mean maximum concentration in plasma of 4.65 microgml(-1) occuring at median tmax = 1.25 h giving a mean AUC(0-infinity) = 28.1 microg h ml(-1). For the i.v. administration, a mean Cmax = 5.53 microm(-1) occurred at the end of the 1-h infusion with a mean AUC(0-infinity) = 25.4 microg h ml(-1). The mean terminal elimination half-life was 7.0 h (oral) and 6.6 h (i.v.). For the oral and i.v. formulations, the mean total plasma clearance was 296 and 263 mlmin(-1), respectively and the mean volume of distribution was 180 and 150 litres, respectively. 3. Within 48 h post-dose, approximately 61% (range 22-86%) of the administered dose was excreted unchanged in urine following capsule administration, compared with approximately 75% (range 42-101%) following the i.v. formulation. For both formulations, the renal clearance of sitafloxacin (means of 181 and 198 ml min(-1) for the capsule and i.v. doses, respectively) implies active tubular secretion of the drug. 4. The absolute bioavailability of sitafloxacin from the capsule formulation was high at 89%, with a 95% CI of 84-94%. The intersubject variability (CV%) in the sitafloxacin AUC(0-infinity) for the capsule was low at 18.6%. 5. Gender differences in the pharmacokinetics of sitafloxacin were small and would not warrant dose adjustment. 6. The findings show that the capsule formulation offers good oral bioavailability and merits further clinical evaluation of sitafloxacin as an orally effective fluoroquinolone antibacterial.

Administration, Oral↗