Biomedical subjects

H Kitagawa

Publications and source records attributed to H Kitagawa.

At least 73 records · Page 4Linked to original sources

PubMed2000

Renal salvage procedure for synchronous bilateral Wilms' tumor.

This report describes a renal salvage procedure performed in a 2-year-old girl with bilateral renal tumors comprising a multilocular, cystic tumor of the right kidney and a solid and cystic nephroblastoma of the left kidney after chemotherapy. Surgery was performed because the right kidney became hydronephrotic due to compression by the enlarged cysts, while the left tumor showed only minimal shrinkage even after three courses of chemotherapy. The right-sided cysts were simply unroofed and the left-sided tumor was extirpated by partial nephrectomy. Her postoperative course was uneventful with considerable recovery of the function of each kidney. This procedure should be considered if the pathological features of the tumor are relatively favourable.

Child, Preschool↗

PubMed2000

The organization of the spinocerebellar tract neurons in the chicken.

The organization of spinocerebellar tract (SCT) neurons in the chicken was studied quantitatively using retrograde wheat germ agglutinin-horseradish peroxidase labelling. The chicken spinal cord was divided into five regions based on the distribution of SCT neurons: the cervical region (the spinal segments [SS], 1-12, which contained 32% of the total number of SCT neurons), the cervical enlargement (SS13-15, 13.4%), the thoracic region (SS16-20, 13%), the thoraco-lumbosacral region (SS21-26, 34.6%), and the posterior lumbosacral region (SS27-30, 7%). Clarke's column was found in two regions, a cervical one (SS12-16) and a lumbar one (SS21-28). The spinal border cells were less numerous and also present in two parts, a cervical one (SS10-15) and a caudal one (SS20-24). SCT neurons of the ventral part of the ventral horn were found in the cervical enlargement and SS16 (lamina VIII), and in the thoraco- and posterior lumbosacral regions (laminae VIII and IX). The ventral marginal nucleus consisted exclusively of SCT neurons but the major and minor marginal nuclei did not contain SCT neurons. In the cervical region most of SCT neurons were observed in the ventral horn, while the central cervical nucleus, which consists of SCT neurons in mammals, was not identified in the chicken.

Animals↗

PubMed2000

Clinical application of argatroban as an alternative anticoagulant for extracorporeal circulation.

The authors attempted experimental and clinical use of argatroban as an alternative anticoagulant in left heart bypass with the centrifugal pump, percutaneous cardiopulmonary support (PCPS), and extracorporeal membrane oxygenation (ECMO) to determine if it has complementary effects in preventing thrombus formation without aggravating bleeding tendency. Its reversible binding to thrombin and its short half-life contributed to reduce the risk of excessive blood loss without clot formation within the extracorporeal circulation circuit during thoracic aortic surgery using left heart bypass. PCPS and ECMO were safely performed at doses ranging from 0.5 to 10 micrograms/kg/min to maintain activated clotting time at approximately 200 seconds. Although experimental studies showed argatroban to be advantageous in preserving platelet and fibrinogen, further clinical investigations are necessary.

Animals↗

PubMed2000

Recent advances in the study of the biosynthesis and functions of sulfated glycosaminoglycans.

Recent cDNA cloning of the glycosyltransferases involved in the synthesis of the sulfated glycosaminoglycan sidechains of proteoglycans has provided important clues to answering long-standing questions concerning the mechanisms of both chain polymerization and the biosynthetic sorting of glucosaminoglycans (heparin/heparan sulfate) and galactosaminoglycans (chondroitin/dermatan sulfate). These biosynthetic mechanisms are crucial to the expression and regulation of the biological functions of glycosaminoglycans in development and pathophysiology.

Glycosaminoglycans↗

PubMed2000

Calphostin C-mediated translocation and integration of Bax into mitochondria induces cytochrome c release before mitochondrial dysfunction.

Calphostin C-mediated apoptosis in glioma cells was reported previously to be associated with down-regulation of Bcl-2 and Bcl-xL. In this study, we report that 100 nM calphostin C also induces translocation and integration of monomeric Bax into mitochondrial membrane, followed by cytochrome c release into cytosol and subsequent decrease of mitochondrial inner membrane potential (DeltaPsim) before activation of caspase-3. The integration of monomeric Bax was associated with acquirement of alkali-resistance. The translocated monomeric Bax was partly homodimerized after cytochrome c release and decrease of DeltaPsim. The translocation and homodimerization of Bax, cytochrome c release, and decrease of DeltaPsim were not blocked by 100 microM z-VAD.fmk, a pan-caspase inhibitor, but the homodimerization of Bax and decrease of DeltaPsim were inhibited by 10 microM oligomycin, a mitochondrial F0F1-ATPase inhibitor. Therefore, it would be assumed that mitochondrial release of cytochrome c results from translocation and integration of Bax and is independent of permeability transition of mitochondria and caspase activation, representing a critical step in calphostin C-induced cell death.

Apoptosis↗

PubMed2000

Comparison of three intra-oral storage phosphor systems using subjective image quality.

OBJECTIVE: To compare the subjective image quality of three intra-oral storage phosphor systems. METHODS: DenOptix (Dentsply/Gendex, Chicago, IL, USA), Digora (Soredex, Helsinki, Finland), and CD-Dent (DigiDent Digital Imaging Technologies, Nesher, Israel) were compared. Two different imaging plates (IPs), BAS300 and HR300 (Fuji Photo Film Co., Tokyo, Japan) were used with the DenOptix system. The specimen was the maxilla and surrounding soft tissues of an adult cadaver. Imaging was at 70 kVp and 8 mA with a focus-detector distance of 38 cm using an optical bench. The exposure times were varied and a panel of five dentists independently evaluated the images produced with each system/IP receptor for seven features; proximal caries, gingival soft tissues, cortical bone, root canal space, root apices, periodontal ligament space and endodontic instrument clarity on a three-interval confidence scale. The best three exposures were chosen according to the highest scores for each system. These images were re-read in random order a total of 10 times. Pair-wise comparisons were made by use of odd's ratio analysis. A 95% confidence interval was applied. RESULTS: Images made with the DenOptix system/BAS IP combination were perceived to have the best overall image quality. The DenOptix/HR IP combination and Digora were rated almost equally in second place. The DigiDent system was ranked inferior. The Digora was considered to be the best for demonstrating gingival soft tissues (P < 0.05) and the DenOptix/HR300 combination the best for clarity of endodontic instruments (P < 0.05). CONCLUSIONS: While the DenOptix/BAS 300 combination was rated highest overall, the ranking of image quality by modality was found to be task-dependent. Digora was rated best for demonstrating gingival soft tissues.

Adult↗

PubMed2000

Computed tomography of emphysema following tooth extraction.

Subcutaneous and tissue space emphysema following surgical extraction of mandibular third molars is a rare and serious complication of dental surgery. Recognition of mediastinal emphysema following surgical extraction is difficult because there are no absolute clinical symptoms and signs. We present two cases of emphysema following extraction of a lower third molar and discuss the contribution of CT to the early recognition of the presence and spatial migration of air and to clinical management.

Adult↗

PubMed2000

Ultrastructural characteristics and lectin-binding properties of M cells in the follicle-associated epithelium of chicken caecal tonsils.

To clarify the nature of M cells, the detailed ultrastructural characteristics and lectin-binding properties of M cells were investigated in follicle-associated epithelium (FAE) of chicken caecal tonsils. M cells presented various outlines from columnar to dome shaped. Their polymorphism was dependent on the number of harboured intraepithelial migrating cells. The lighter and larger nuclei of M cells were situated at more apical levels in the epithelial lining compared with those of neighbouring microvillous epithelial cells. The microvilli, which were significantly shorter and thicker than those of adjacent microvillous epithelial cells, were sparsely distributed or completely absent on the apical surfaces of M cells. In general, the apical cytoplasm of M cells without microvilli protruded slightly into the intestinal lumen. Numerous small vesicles were often contained in the apical cytoplasm. The numerous small invaginations of the apical and lateral cell surfaces suggested active transportation of luminal substances. No canaliculi existed in the apical cytoplasm of M cells whereas they were often detected in the neighbouring microvillous epithelial cells. A noteworthy finding was the frequent detection of multivesicular bodies in the apical cytoplasm of M cells. These multivesicular bodies suggest some degradation of ingested luminal substances during transcytoplasmic transportation. WGA and 4 other lectins strongly reacted with all epithelial cells except for M cells, this negativity suggesting a means of detecting M cells in chicken caecal tonsils. Three lectins, DSL, ConA and Jacalin, reacted weakly with the glycocalyx on M cells. The positive reactivity might allow chicken M cells to be utilised for specific antigen delivery into the mucosal immune system in some parenteral vaccinations.

Animals↗

PubMed2000

Early fetal obstructive uropathy produces Potter's syndrome in the lamb.

BACKGROUND: If creating an obstructive uropathy early in glomerulogenesis produces MCDK (Multicystic Dysplastic Kidney), then a very early obstruction may produce Potter's Syndrome (PS) with oligohydramnios. METHODS: Fetal lambs at 50 days' gestation underwent urethral and urachal ligation using fine SILASTIC (Dow Corning, Midland, MI) tubing and were delivered by cesarean section at 145 days' gestation. At the time of death, kidney weight, length, and lung volumes were measured. These samples were examined histologically. Urinary sodium, chloride, potassium, and osmolarity also were measured. These were compared with normal-term fetuses. RESULTS: One ewe miscarried. Two of 3 of 50-day obstructive uropathy lambs survived. The 2 survivors had dysplastic kidneys. One with large gastroschisis did not have PS but the other had renal, pulmonary, and chest wall hypoplasia. Both male lambs had undescended testes with a large bladder. Kidney weights were 2 g in the PS lamb and 16 g in controls. Lung volume was 84 mL in the PS lamb and 340 mL in controls. The lamb's face was compressed and the fetus was hydropic. Urine sodium, potassium, and osmolarity levels were higher than that of controls. CONCLUSIONS: This is the first successful model ligating the penile urethra and urachus in a 50-day lamb. The authors' previous 60-day model did not have PS, but an earlier obstructive uropathy caused MCDK with PS.

Abnormalities, Multiple↗

PubMed2000

Glomerular size in renal dysplasia secondary to obstructive uropathy: a further exploration of the fetal lamb model.

BACKGROUND/PURPOSE: Creating an obstructive uropathy early in glomerulogenesis would produce multicystic dysplastic kidneys (MCDK). Measuring the mean planar area of the glomeruli (GMPA) may clarify the pathogenesis of MCDK. METHODS: Fetal lambs at 60 days' gestation had their left ureter ligated and were delivered by cesarian section at 145 days' gestation. Kidney weight and length were recorded. GMPA in 3 zones (outer, middle, inner) of the sectioned kidney was measured using a computerized planimeter. The obstructed kidneys were compared with contralateral unobstructed kidneys. The unpaired Student's t test was used to determine significance. RESULTS: One ewe miscarried. Four of 5 (80%) 60-day lambs survived. All had dysplastic kidneys. Mean kidney weights were 4.3 +/- 0.84 g in MCDK and 16.8 +/- 3.6 g in controls (P< .05). The GMPA of the outer, middle, and inner zones of the MCDK were 2.7 x 10(-3) mm2, 3.2 x 10(-3) mm2, and 4.0 x 10(-3) mm2, respectively. Controls were 2.8 x 10(-3) mm2, 4.4 x 10(-3) mm2, and 6.0 x 10(-3) mm2. The glomeruli of 60-day fetal kidneys were 3.0 x 10(-3) mm2, 6.1 x 10(-3) mm2, and 11.0 x 10(-3) mm2. MCDK had smaller glomeruli in the inner and middle zones than controls. CONCLUSION: Fetal glomeruli appear to grow from the inner zone of the kidney. Early urinary tract obstruction stops this growth.

Animals↗

PubMed2000

Protective effect of ginkgo extract on rat brain with transient middle cerebral artery occlusion.

It has been empirically known that Ginkgo extract is useful for reducing many symptoms associated with cerebral blood flow (CBF) insufficiency, but its mechanisms have been uncertain. In the present study, therefore, we gave Ginkgo extract to rats with per os digestion, and investigated its effect on CBF and ischemic brain damage with middle cerebral artery occlusion (MCAO). The treatment with Ginkgo extract (10 mg 100 g-1 rat) increased CBF in the normal condition, but the degree of increase in CBF was lesser during and after MCAO. TTC staining showed that infarct volume was reduced with Ginkgo treatment. TUNEL and HSP72 immunostaining confirmed the protective effect of Ginkgo treatment reducing numbers of TUNEL and HSP72 positive cells. Immunohistochemical analysis showed that caspase-3 expression was less abundant in Ginkgo treated rats. The present results suggest that Ginkgo extract contains a substance which increases normal CBF and reduces ischemic brain damage.

Animals↗

PubMed2000

Temporal profile of cytochrome c and caspase-3 immunoreactivities and TUNEL staining after permanent middle cerebral artery occlusion in rats.

Although apoptotic pathways play important roles in ischemic neuronal injury, exact mechanism of apoptotic enzyme cascade has not been fully studied. Immunohistochemical stainings for cytochrome c and caspase-3, and histochemical staining for a terminal deoxynucleotidyl-transferase (TdT)-mediated dUTP-biotin nick end-labeling method (TUNEL) were examined in a rat model of permanent middle cerebral artery (MCA) occlusion. Cytochrome c was strongly induced in neurons of the ischemic penumbra from 3 h after MCA occlusion, and caspase-3 began to be induced in the same area from 3 h with a peak at 8 h. Neuronal cells in MCA area became TUNEL positive at delayed time, reaching a peak at 24 h. Thus, the peak of induction of cytochrome c preceded that of caspase-3, and these two peaks were also precedence of the peak of DNA-fragmentation. Western blot analysis showed cytosolic expression of cytochrome c from mitochondria. This study demonstrated 1. Rapid release of cytochrome c from mitochondria to the cytosol, mainly in neurons of the cortex at 3 h after ischemia. 2. Subsequent peaks of caspase-3 and TUNEL in this order. These temporal profiles suggest a serial cascadic activation of apoptotic pathways in neuronal death after permanent MCA occlusion of rats.

Animals↗

PubMed2000

Perioperative management of a patient requiring surgery for pituitary apoplexy and severe angina pectoris.

We describe the management of a 71-yr-old man with pituitary apoplexy and severe angina pectoris who underwent treatment of an intra-cranial haemorrhage and open-heart surgery requiring anticoagulant therapy within a very short period. Subtotal removal of the pituitary tumour was undertaken under stable cardiovascular conditions. But ventricular fibrillation occurred after the neurosurgery in the intensive care unit. After the patient was defibrillated, intra-aortic balloon pumping was necessary to assist coronary artery blood flow. Twenty hours after neurosurgery, oozing from the surgical wound stopped and coronary artery bypass grafting with full heparinization was performed uneventfully.

Aged↗

PubMed2000

The EXT1/EXT2 tumor suppressors: catalytic activities and role in heparan sulfate biosynthesis.

The D-glucuronyltransferase and N-acetyl-D-glucosaminyltransferase reactions in heparan sulfate biosynthesis have been associated with two genes, EXT1 and EXT2, which are also implicated in the inherited bone disorder, multiple exostoses. Since the cell systems used to express recombinant EXT proteins synthesize endogenous heparan sulfate, and the EXT proteins tend to associate, it has not been possible to define the functional roles of the individual protein species. We therefore expressed EXT1 and EXT2 in yeast, which does not synthesize heparan sulfate. The recombinant EXT1 and EXT2 were both found to catalyze both glycosyltransferase reactions in vitro. Coexpression of the two proteins, but not mixing of separately expressed recombinant EXT1 and EXT2, yields hetero-oligomeric complexes in yeast and mammalian cells, with augmented glycosyltransferase activities. This stimulation does not depend on the membrane-bound state of the proteins.

Animals↗

PubMed2000

Seroepidemiological investigation of feline chlamydiosis in cats and humans in Japan.

The prevalence of chlamydia antibodies in Japan was investigated in 215 cat sera, consisting of 88 sera of stray cats and 127 sera of pet cats, and 2,184 human sera, taken from 2,003 general persons and 181 small animal clinic veterinarians, by microimmunofluorescence (MIF) testing with Chlamydia psittaci Fe/Pn1 of feline origin and Prk/6BC of avian origin as antigens. The prevalence rates of anti-Fe/Pn1 antibodies were 45.5% in stray cats, 17.3% in pet cats, 1.7% in general persons and 8.8% in small animal clinic veterinarians. The prevalence rates of anti-Prk/6BC antibodies were 51.1% in stray cats, 15.0% in pet cats, 3.1% in general persons and 5.0% in small animal clinic veterinarians. These results suggested that feline chlamydia infection is widely spread in cats especially in stray cats in Japan, and suggested that feline chlamydiosis could be transmitted to people who are in close contact with infected cats.

Animals↗

PubMed2000

A novel missense mutation of mineralocorticoid receptor gene in one Japanese family with a renal form of pseudohypoaldosteronism type 1.

Pseudohypoaldosteronism type 1 (PHA1) is a rare condition characterized by neonatal salt loss with dehydration, hypotension, hyperkalemia, and metabolic acidosis, despite elevated plasma aldosterone levels and PRA. Two modes of inheritance of PHA1 have been described: an autosomal dominant form and an autosomal recessive form. An autosomal recessive form manifests severe life-long salt wasting resulting from multiple mineralocorticoid target tissue such as sweat, salivary glands, the colonic epithelium, and lung. Contrary, an autosomal dominant PHA1 manifests milder salt wasting that gradually improves with advancing age. Recently, in one sporadic and four dominant cases, four different mutations including two frame shift mutations, two premature termination codons, and one splice site mutation in the mineralocorticoid receptor (MR) gene were identified. We studied the molecular mechanisms of one Japanese family with a renal form of PHA1. PCR and direct sequencing of the MR gene identified a heterozygous point mutation changing codon 924 Leu (CTG) to CCG (Pro) (L924P) in all affected members. COS-1 cells were transfected with expression vectors for either wild type or the mutant MR-L924P receptors, together with the reporter plasmid (glucocorticoid response element tk-CAT). Aldosterone increased CAT activity in cells expressing wild-type receptor, but had no effect in cells expressing the mutant receptors. These results suggest that mineralocorticoid resistance in this family is due to a missense mutation in the MR gene. To our knowledge, this is the first case of the missense mutation of the MR gene in renal PHA1.

Adolescent↗

PubMed2000

Characterization of transactivational property and coactivator mediation of rat mineralocorticoid receptor activation function-1 (AF-1).

The autonomous activation function-2 (AF-2) in the mineralocorticoid receptor (MR) E/F domain is known to play a major role in the ligand-induced transactivation function of MR; however, it remained unclear about the transactivation function of its A/B domain. We therefore tried to characterize the MR A/B domain as the AF-1 and further studied the actions of known coactivators for AF-2 in the E/F ligand-binding domain in the function of the MR A/B domain. Deletion analyses of rat and human MRs revealed that the A/B domains harbor a transactivation function acting as AF-1. The MR mutant (E959Q) with a point mutation in helix 12, which causes a complete loss of MR AF-2 activity, still retained ligand-induced transactivation function, indicating a significant role for AF-1 in the full activity of the ligand-induced MR function. Among the coactivators tested to potentiate the MR AF-2, TIF2 and p300 potentiated the MR AF-1 through two different core regions [amino acids (a.a.) 1-169, a.a. 451-603] and exhibited functional interactions with the MR A/B domain in the cultured cells. However, such interactions were undetectable in a yeast and in an in vitro glutathione-S-transferase pull-down assay, indicating that the functional interaction of TIF2 and p300 with the MR A/B domain to support the MR AF-1 activity require some unknown nuclear factor(s) or a proper modification of the A/B domain in the cells.

Animals↗

PubMed2000

Abnormal distribution of anionic sites in the glomerular basement membrane in glomerulonephritis of dogs infected with Dirofilaria immitis.

Ultrastructural alteration of anionic sites (ASs) in the glomerular basement membrane (GBM) was studied in glomerulonephritis characterized by linear capillary IgG deposition in four dogs infected with Dirofilaria immitis and two normal control dogs using polyethyleneimine. ASs were identified as small dense particles distributed regularly in the lamina rara externa (LRE), but there were no ASs in the lamina densa (LD) of the GBM of the control dogs. In the glomeruli of the infected dogs, ASs were distributed regularly or irregularly in the thickened LD. ASs were in addition localized over the characteristic continuous bands of subendothelial dense deposits. The number of ASs of the LRE increased in all four infected cases as compared to the controls (p<0.01).

Animals↗