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H Fujisawa

Publications and source records attributed to H Fujisawa.

At least 109 records · Page 6Linked to original sources
PubMed1998

Correlation between tectum formation and expression of two PAX family genes, PAX7 and PAX6, in avian brains.

Heterotopic transplantation of brain vesicles between chick and quail were performed, and the correlation between tectum formation and the expression of two PAX family genes, PAX7 and PAX6, analyzed. Reciprocal transplantation between the prosencephalon and mesencephalon showed that formation of the tectum always coincided with induction/maintenance of PAX7 and suppression of PAX6, indicating that switch-on or -off of these two PAX family genes in region specific manners are responsible for the differentiation of brain vesicles into the tectum. On the other hand, transplantation of the mesencephalic floor plate into the dorsal mesencephalon suppressed PAX7 expression in the dorsal mesencephalon and changed its fate from the tectum to the tegmentum, indicating that factors in the mesencephalic floor plate suppress PAX7 and limit tectum territory to the dorsal part of the mesencephalon.

Animals↗
PubMed1998

Accelerated aging of dermal fibroblast-like cells from the senescence-accelerated mouse (SAM): acceleration of changes in DNA ploidy associated with in vitro cellular aging.

Accelerated changes in the DNA ploidy associated with in vitro aging were examined in fibroblast-like cells isolated from the dorsal dermis of newborn SAMP11 (accelerated senescence-prone, short-lived) mice, and were compared to changes observed in cell lines from SAMR1 (accelerated senescence-resistant, long-lived) mice. Flow cytometric analysis of the DNA content in confluent cells and chromosome analysis in mitoses revealed that the diploid cells were being replaced with tetraploid cells until a growth crisis; thereafter, hypotetraploid cells became predominant, accompanied by immortalization. The number of mitoses decreased as the crisis ensued, then increased. Although these changes were observed in the cell lines from both strains of mice, the changes occurred more rapidly and at earlier population doublings in the cell lines from the SAMP11 mice. These results suggest that the cell lines from SAMP11 mice might have higher susceptibility to factors that cause polyploidization, including oxidative stress.

Aging↗
PubMed1998

Feasibility of the titration method of mild hypothermia in severely head-injured patients with intracranial hypertension.

OBJECTIVE: Clinical strategy to maximize effectiveness and to minimize adverse influences remains to be determined for mild hypothermia therapy for traumatic brain injury. This study was conducted to evaluate the clinical feasibility of the titration method of mild hypothermia in severely head-injured patients in whom a reduction in intracranial pressure was regarded as the target effect. METHODS: Nine consecutive patients with severe head injury were studied. Patient age ranged between 18 and 66 years, Glasgow Coma Scale scores were equal to or less than 8, and intracranial pressures were equal to or greater than 20 mm Hg despite removal of intracranial hematoma and drugs, including glycerol and thiopental. During a maximum of 6 days of hypothermia therapy, jugular venous blood or cerebrospinal fluid temperature was titrated to reduce intracranial pressure to less than 20 mm Hg by means of repeated intragastric cooling with our nasoduodenal tube and surface cooling. The feasibility and the effects on systemic complications of this titration method of mild hypothermia were evaluated. RESULTS: Intracranial pressure variably decreased from before to 3 hours after the beginning of all procedures of cooling. The mean intracranial pressure significantly decreased from 24 to 15 mm Hg with cooling, while temperature reduced an average of 2.0 degrees C. Four patients had systemic infection complications. Increased C-reactive protein and decreased platelet count were observed in all patients during hypothermia. The incidence of good recovery and moderate disability according to the Glasgow Outcome Scale was seven of nine patients. CONCLUSION: The titration method of mild hypothermia to control intracranial hypertension in severely head-injured patients is clinically feasible. However, the method failed to reduce the incidence of infectious and hematological complications.

Adolescent↗
PubMed1998

Symptomatic spinal arachnoid cyst triggered by seat belt injury--case report.

A 49-year-old male presented with a symptomatic thoracic intradural arachnoid cyst triggered by seat belt trauma, which appeared within 3 weeks following a traffic accident. The initial symptom was a dull back pain induced immediately after the accident. Three and half months later, magnetic resonance (MR) imaging diagnosed the cystic nature of the lesion consistent with a low intensity on T1-weighted image which extended dorsally between the T-4 and T-6 levels. One month later, MR imaging showed that this cystic mass had enlarged in the anteroposterior direction associated with developing clinical symptoms. The final diagnosis of arachnoid cyst was made based on surgical findings and histological examinations. The spinal arachnoid cyst was probably a congenital arachnoid cyst or diverticula originating from the septum posticum which became enlarged due to sudden increase of intra-abdominal pressure caused by the fastened seat belt during the accident.

Accidents, Traffic↗
PubMed1998

Acute cauda equina syndrome secondary to lumbar disc herniation mimicking pure conus medullaris syndrome--case report.

A 49-year-old male presented with a rare case of acute cauda equina syndrome secondary to a sequestrated lumbar disc mimicking pure conus medullaris syndrome. He consulted the emergency room of Otsu Municipal Hospital because saddle anesthesia and complete urinary retention which had started 2 days before admission. Additionally, he complained of constipation and impotence. Abnormality of the deep tendon reflexes, sciatica, and leg weakness were not organized. Emergent myelography and subsequent computed tomography revealed a sequestrated disc in the sacrum compressing the lower cauda equina, but not the conus medullaris. Emergent surgical decompression was performed about 60 hours after the onset. The patient almost fully recovered from sphincter dysfunction, impotence, and saddle anesthesia 3 months after the operation. When a syndrome like conus medullaris compression is encountered, the lower cauda equina should be examined as well as the conus level. Such cases require urgent diagnosis and treatment.

Cauda Equina↗
PubMed1998

[A case of laparoscopic nephrectomy for ectopic vaginal ureter in a child].

An 11-year-old girl presented with continuous incontinence since infancy. Neither intravenous pyelography nor renal scintigraphy demonstrated the left upper urinary tract, but a very small left kidney was detected close to the 3rd lumbar vertebrae on computed tomography (CT). After cystoscopy, the patient was diagnosed with ectopic vaginal ureter and hypoplastic kidney. Laparoscopic nephrectomy was performed. Before surgery, a ureteral occlusion catheter was inserted through the meatus which opened in the vagina. The catheter was very useful for locating the small kidney during surgery. The procedure was successful and the surgical duration was short (123 min.) with only slight hemorrhage (15 ml). The patient was able to attend school on the seventh postoperative day. We recommend laparoscopic surgery for the treatment of ectopic ureter.

Child↗
PubMed1998

[Clinical study of transcatheter arterial embolization for pulmonary arteriovenous fistula].

PURPOSE: To evaluate the efficacy of transcatheter arterial embolization for pulmonary arteriovenous fistula (PAVF). MATERIALS AND METHODS: Eight patients with 14 PAVFs were treated by TAE for feeding arteries. In 5 of 8 cases, detachable balloons were used, and, in 3 of 8 cases, metalic coils were used for embolization of the feeding arterial branch. Detachable balloons or a series of metalic coils were placed at the feeding artery proximal to the fistula. The diameter of detachable balloons was twice the diameter of the feeding arterial branch. The diameter of metalic coils was 1 mm larger than the diameter of the feeding artery. RESULTS: No complications were apparent in our cases. All PAVFs were completely occuluded by the embolization of a feeding branch. One month after the procedures, the arterial oxygen pressure increased to normal values in all cases and clinical symptoms disappeared. On postcontrast CT, the fistulas treated by the embolization of a feeding arterial branch were not enhanced. CONCLUSION: The embolization of a feeding branch provided a radical cure for PAVFs.

Adult↗
PubMed1998

Enhanced interleukin 6 production by cultured fibroblasts from patients with systemic sclerosis in response to platelet derived growth factor.

OBJECTIVE: The pathophysiology of systemic sclerosis (SSc) is poorly understood, but recent studies indicate the involvement of cytokines in the functional changes of SSc fibroblasts. We investigated interleukin 6 (IL-6) production by dermal fibroblasts from patients with SSc. METHODS: Fibroblast cultures were established from affected skin of patients with SSc and from skin of healthy controls. IL-6 in supernatants from cultured fibroblasts was measured using a specific IL-6 ELISA. RESULTS: SSc fibroblasts, starved in serum-free medium, produced only a small amount of IL-6. However, IL-6 production by SSc fibroblasts dramatically increased when the cells were cultured in serum-containing medium. Human whole blood serum was more effective than human platelet-poor plasma derived serum in the enhancement of IL-6 production by SSc fibroblasts. Platelet derived growth factor (PDGF)-AA and PDGF-BB, a major growth factor in serum, induced significant IL-6 production by SSc fibroblasts. In contrast, in normal fibroblasts, much less response to PDGF-BB and almost no response to PDGF-AA were observed. Expression of PDGF receptors on SSc fibroblasts was not significantly different from normal fibroblasts. However, IL-1 receptor antagonist (IL-1ra), when added in the medium, significantly inhibited the PDGF-induced IL-6 production by SSc fibroblasts. CONCLUSION: PDGF stimulates IL-6 production by SSc fibroblasts. The enhanced IL-6 production in response to PDGF is due in part to autocrine IL-1 of SSc fibroblasts. These abnormalities of fibroblasts may play an important role in the inflammatory and immunological processes of SSc.

Adult↗
PubMed1998

[CaM-kinases].

Explore the source record for details and available documents.

Adenosine Triphosphate↗
PubMed1998

[Radiologic features of superficial-type hyperplastic polyps in the large intestine].

We studied 38 superficial-type hyperplastic polyps of more than 0.6 cm in size on radiographs to examine their morphologic features. The 38 lesions ranged in size from 0.6 cm to 2.5 cm, and 22 were located in the sigmoid and transverse colon (Table 1, Fig.1). The cross-section and surface configurations of the 38 lesions studied radiographically are illustrated in Fig. 2. 24 lesions without central depression were classified into 5 groups (1-a to 1-e). The 14 other lesions had central depression (2-a). The cross-section configuration was sharp in all lesions, and a finely serrated arrangement was seen in 30 of them. In surface configuration, several granular patterns were seen, but full-blown undulated folds and/or regular granular patterns were characteristic in groups 1-c, 1-d and 2-a. These radiologic features of cross-section and surface configuration may be regarded as a possible means of distinguishing superficial-type hyperplastic polyps from adenomas and carcinomas of the large intestine.

Adult↗
PubMed1997

Depressed Langerhans cell migration and reduced contact hypersensitivity response in mice lacking TNF receptor p75.

Epidermal Langerhans cells (LC) belong to the dendritic cell family and represent the major APC within the skin. LC capture epicutaneous Ag, migrate into regional lymph nodes, and present Ag to T cells, thereby initiating primary immune response. The migratory properties of LC are an essential component of their function. The molecular mechanisms responsible for LC migration are far less defined. However, evidence has been accumulating to suggest that TNF-alpha, a major proinflammatory cytokine, plays an important role in promoting DC migration. To confirm the role of TNF-alpha in LC migration and to examine which type of TNF receptor signaling is involved in such an event, we utilized gene-targeted knockout mice lacking TNF receptor p55 or p75. The migration of LC was assessed by examining the frequency of hapten-bearing cells in draining lymph nodes following hapten FITC painting, and the accumulation of dendritic cells in draining lymph nodes after intradermal injection of TNF-alpha. While LC migration was normal in p55-deficient mice, the migration was markedly depressed in p75-deficient mice. Receptor p75-deficient mice also demonstrated a hyporesponsiveness in allergen-induced contact dermatitis, but a normal responsiveness in irritant-induced contact dermatitis. These results suggest that p75-dependent signaling plays a crucial role in the migration of LC and in the initiation of cutaneous immune responses.

Administration, Cutaneous↗
PubMed1997

Early development of the oligodendrocyte in the embryonic chick metencephalon.

It has been demonstrated that the spinal cord oligodendrocytes in the vertebrates arise in the ventral ventricular zone adjacent to the floor plate in their early development. Because of the similarities of basic structures in the spinal cord and metencephalon, it is probable that the mode of early oligodendrocyte development in the metencephalon is the same as that in the spinal cord. We examined this possibility in chick embryos, using monoclonal antibodies O1 and O4, markers for oligodendrocyte lineage. An O4-positive (O4+) cell focus was observed in the medial ventricular zone of E5 chick ventral metencephalon (the earliest stage examined), adjacent to the floor plate. At E6, O4+ cells were dispersed from the medial to the lateral pons and, at E7, to the cerebellar anlagen. O4+ cells in the E6 brainstem and in the E7 cerebellum were unipolar in shape, whereas one day later, some of the labeled cells were multipolar with a few thin processes. O1+ oligodendrocytes first appeared at E8 in the ventromedial part of the pons and were distributed throughout the pons at E10 and in the cerebellum at E12. Explants from three subdivisions of the metencephalon (medial and lateral pons, and cerebellum) from E5 to E8 chick embryos were separately cultured to confirm the potential for generation of oligodendrocyte lineage. O4+ cells appeared in the culture of the E5 medial pons (the earliest stage examined), in the E6 lateral pons, and in the E7 cerebellum. In addition, E7 was the youngest stage from which cerebellar explants were able to generate O1+ oligodendrocytes. Our results clearly demonstrated the in vivo morphology of oligodendrocyte precursors in the metencephalon and their developmental appearance in a ventral-to-dorsal manner. From the bipolar morphology of O4+ cells and the spacio-temporal continuity of the dispersion, it is inferred that the initial dispersion of O4+ cells may involve oligodendrocyte migration from the focus of the medial pons to the lateral and dorsal parts of the metencephalon.

Animals↗
PubMed1997

Detection of protein phosphatase activities in sodium dodecyl sulfate-polyacrylamide gel using peptide substrates.

A method for detection of protein phosphatase activity toward phosphorylated oligopeptides in SDS-polyacrylamide gel was developed. A synthetic peptide (MHRQETVDC) corresponding to the autophosphorylation site of calmodulin-dependent protein kinase II (residue 281-289) was conjugated to poly-L-lysine and phosphorylated with [gamma-32P]ATP by the action of calmodulin-dependent protein kinase II, and the [32P]-phosphopeptide-polymer conjugate was included as a substrate for protein phosphatases in gels. When a crude extract from rat brain was electrophoresed on polyacrylamide gel containing the [32P]phosphopeptide conjugate, followed by treatment for in situ renaturation and autoradiography, three transparent bands corresponding to apparent molecular weights of 52,000, 58,000 and 74,000, resulting from the removal of the [32P]phosphate from the phosphopeptide conjugate included in the gel were observed, indicating the existence of at least three different phosphoprotein phosphatases catalyzing dephosphorylation of the phosphopeptide in the brain. Among the three, two bands corresponding to molecular weights of 52,000 and 58,000 were not clearly observed when other phosphopeptide-polymer conjugates such as C-syntide-2 and CAMKAKS peptide were included in gels, suggesting that site-specific protein phosphatases can be detected in crude tissue extracts by this in-gel protein phosphatase assay.

Amino Acid Sequence↗
PubMed1997

Effects of mild hypothermia on cerebral blood flow-independent changes in cortical extracellular levels of amino acids following contusion trauma in the rat.

The mechanism of hypothermic cerebroprotection after traumatic brain injury (TBI) is unknown. The present study was conducted to investigate the effects of mild hypothermia on the changes in cortical extracellular amino acids and cerebral blood flow (CBF) caused by cerebral contusion created in the rat parietal cortex by a weight-drop method. CBF in both normothermia (37 degrees C) and hypothermia (32 degrees C) groups, which was monitored using the hydrogen clearance technique, decreased significantly after contusion, but never fell below the threshold for ischemia. Cortical levels of glutamate, aspartate, glycine and taurine, which were measured by intracerebral microdialysis, were significantly increased after contusion in each group. However, these increases were greater in the hypothermic than in the normothermic rats. Normal plasma amino acid levels were high, and autoradiography following intravenous injection of 14C-labeled glutamate revealed marked extravasation of [14C]glutamate at the site of cortical impact. These results suggest that the post-traumatic increase in extracellular amino acids occurs independently of CBF reduction, and that extravasation of amino acids from the vascular compartment partly contributes to this increase. Hypothermic cerebroprotection in TBI is thus likely to occur through a mechanism other than reduction in interstitial excitatory amino acids. In TBI, it is postulated that the postsynaptic effects of hypothermia may be more important than the presynaptic effects, when CBF is kept above the ischemic threshold.

Amino Acids↗
PubMed1997

Cortex-specific distribution of membrane-bound factors that promote neurite outgrowth of mitral cells in culture.

To analyze regional differences in the embryonic mouse brain with respect to environmental influence on mitral cell neurites, olfactory bulb fragments were cultured on layers of brain cells which had been dissociated from various regions. Long mitral cell neurites elongated on paleocortex and neocortex cell layers, but not on the septum, mesencephalon, or diencephalon cell layers. Cell membranes prepared from the paleocortex and neocortex also supported outgrowth of long mitral cell neurites, but cell membranes prepared from the septum, mesencephalon, or diencephalon did not. The supportability of mitral cell neurites in the paleocortex and neocortex membranes was completely abolished by trypsin treatment. Neurite outgrowth of the mitral cells on poly-L-lysine was not inhibited by the mesencephalon or diencephalon membranes, but was promoted by the paleocortex and neocortex membranes. These results indicate that the paleocortex and neocortex regions selectively express membrane-bound factors which promote neurite outgrowth of mitral cells.

Animals↗