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Biomedical subjects

H Kitagawa

Publications and source records attributed to H Kitagawa.

At least 163 records · Page 9Linked to original sources
PubMed1998

Quantitative studies of nuclear bodies in astrocytes of chicken spinal cord following axotomy.

The present study was designed to reveal whether astrocytic activation following axotomy causes a numerical increase of nuclear bodies (NBs) in chicken astrocytes. Astrocytes in the spinal cord were activated by a unilateral spinal nerve transection. The frequency of NBs was calculated at the lateral motor columns of the normal group and at the ipsi- and contralateral sides of operated group. In the growing chickens, NBs of each astrocyte were a few and decreased steadily in number with age. In the operated chickens, the frequency of NBs elevated temporarily both in the ipsi- and contralateral sides, and reached its maximum value by 30 post-operative days. The frequency of NBs increased more prominently in the operated side than in the unoperated side. Thus, the present study provides the first evidence for a significant increase in the number of NBs in the hyperactive astrocytes caused by axotomy.

Animals↗
PubMed1998

Cationic trypsinogen produced by human pancreatic ductal cancer has the characteristics of spontaneous activation and gelatinolytic activity in the presence of proton.

We examined whether human pancreatic ductal cancer cells express and secrete pancreatic cationic trypsinogen in vitro which can be spontaneously converted into active trypsin at acidic pH (pH 4.5-5. 5), in contrast to anionic trypsinogen. Cationic trypsinogen expression at the mRNA level was observed in differentiated Capan-1 and BxPC-3 cell lines. However, expression was not detected in either poorly-differentiated Panc-1 or undifferentiated MIAPaCa-2 cell line. The gelatinolytic activity of the activated form of trypsinogen in each conditioned medium in the presence of enterokinase (1.0 microg/ml) (a band with a molecular weight of approximately 23 kDa) corresponded well to the level of cationic trypsinogen mRNA. The spontaneous activation of trypsinogen also was observed by gelatin zymography of the acid-loaded conditioned medium (pH 5.5). These findings suggest that trypsinogen produced by human pancreatic ductal cancer has the characteristics of spontaneous activation and gelatinolytic activity in the presence of proton.

Culture Media, Conditioned↗
PubMed1998

Pathologic findings in dogs with shock induced by intravenous administration of heartworm extract.

OBJECTIVE: To examine pathologic findings in dogs with shock induced by IV administration of heartworm (HW) extract. ANIMALS: 22 mixed-breed adult dogs. PROCEDURES: Heartworm extract was administered IV, and pathologic changes in dogs that died or were euthanatized at 24 hours were examined. RESULTS: The most severe lesions observed during initial collapse were centralobular congestion in the liver, hemorrhage and edema in the gallbladder wall, and congestion and hemorrhage in mucous membranes of the gastrointestinal tract. These findings disappeared with recovery from collapse. Hyalinization of venous walls of the liver and cardiac muscle were observed in dogs that died during initial collapse. Focal coagulation necrosis in hepatic cells was seen in dogs that were euthanatized at 24 hours. One dog with profuse bloody diarrhea that died during secondary collapse had severe hemorrhage in mucous membranes of the large intestine. CONCLUSION: Heartworm extract appeared to contain some substances constricting hepatosplanchnic vessels and some toxic substances that injured the smooth muscle of venous walls, cardiac muscle, and hepatic cells directly or indirectly. CLINICAL RELEVANCE: The shock-inducing substances in HW extract may have an important role in the pathophysiologic mechanism of HW disease, and investigation of them may contribute to prevention of the shock reaction attributable to microfilaricide and adulticide use.

Anaphylaxis↗
PubMed1997

Developmental regulation of the sulfation profile of chondroitin sulfate chains in the chicken embryo brain.

Developmentally regulated and cell type-specific expression of distinct sulfated glycosaminoglycan structures on cell surface proteoglycans is increasingly recognized as providing information relevant to cell-cell interactions and differentiation in developing organisms. In this report, developmental regulation of both the sulfation profile of chondroitin sulfate chains and activities of chondroitin 4-sulfotransferase (C4ST) and chondroitin 6-sulfotransferase (C6ST) were evaluated in embryonic chicken brain. The results revealed that the sulfation profile and the sulfotransferase activities changed markedly with development, and these alterations were precisely coordinated. Specifically, the proportions of both chondroitin 6-sulfate to 4-sulfate and C6ST to C4ST activities progressively decreased with development. In addition, the total amounts of both chondroitin sulfate chains and the sulfotransferase activities were highest during early embryonic stages and decreased sharply as the development reached completion. The developmental expression of the C6ST gene was also found to parallel the developmental down-regulation of both the C6ST activity and the chondroitin 6-sulfate structure. These findings suggest that the developmentally regulated expression of the sulfotransferases is a predominant factor for stage-specific regulation of chondroitin sulfate structures.

Animals↗
PubMed1997

Detection of canine pemphigus foliaceus autoantigen by immunoblotting.

The antigens targeted by autoantibodies in sera from canine patients with pemphigus foliaceus (PF) were detected by indirect immunofluorescence and Western immunoblotting. The extracted proteins from canine keratinocytes cultured in high-calcium condition for 48 h after confluency and from bovine nose epidermis were used as antigens in Western blotting. Canine keratinocytes cultured in high-calcium condition showed fluorescent deposits in intercellular spaces by incubation with sera from both canine and human pemphigus patients. By Western blotting, eight out of 16 canine PF sera recognised 160 kDa protein. 85 kDa and 120 kDa proteins were also recognised by four to five canine PF sera, respectively. The 160 kDa band, recognised by eight canine PF sera, had an identical mobility to the protein identified by a human PF serum. These results suggested that the autoantibodies in sera from canine PF recognised the 160 kDa desmosomal proteins, which may correspond to the desmoglein 1.

Animals↗
PubMed1997

Clinical and electrophysiologic characteristics of compressed lumbar nerve roots.

STUDY DESIGN: Clinical and electrophysiologic data of compressed nerve roots were evaluated in patients with lumbar disc herniation. OBJECTIVES: To elucidate the characteristics of the nerve root with respect to preoperative neural deficit and to analyze the predictive factors for recovery of leg paralysis after posterior discectomy. SUMMARY OF BACKGROUND DATA: Prolonged paralysis due to disc herniation is reported to be a poor prognostic factor for motor recovery. In addition, an intraoperative somatosensory evoked potential change has been reported to be correlated with clinical outcome. METHODS: Among 64 patients with a lumbar disc herniation, a variety of clinical data, such as age, gender, duration of leg paralysis or leg pain, the angle of the positive straight leg raising test, and time for recovery from paralysis, were investigated. In addition, threshold, amplitude of compound muscle action potentials, and latency for 85 nerve roots were monitored before and after discectomy. Data were analyzed according to the grade of preoperative neural deficits: Grade 1, severe motor and sensory loss; Grade 2, mild motor and sensory loss; Grade 3, sensory loss only; Grade 4, no deficit (leg pain only); and Grade 5, asymptomatic control. RESULTS: The nerve root threshold before discectomy showed an increase in accordance with the severity of neural deficit. Thresholds of Grade 1 and 2 nerve roots were significantly higher than those of normal control subjects. The average amplitudes of compound muscle action potentials before discectomy in Grade 1 and 2 nerve roots were significantly lower than those of asymptomatic control nerve roots. Elongation of latency also showed a correlation with preoperative neurologic abnormality. Patients who complained of leg pain only were significantly younger, and those who showed severe motor disturbance tended to be older and to show a straight leg raising test angle similar to that of control nerve roots. Severe motor weakness for more than 6 months, a negative straight leg raising test, and age were considered to be poor prognostic factors for motor recovery. CONCLUSIONS: Findings of increased threshold, low amplitude of compound muscle action potentials, and elongated latency correlated with degree of motor weakness. Early decompression for compressed nerve root is recommended, especially in older patients with severe motor weakness presenting a negative straight leg raising test.

Action Potentials↗
PubMed1997

omega-Conotoxin GVIA and desipramine insensitive norepinephrine efflux from cardiac sympathetic nerve terminal.

Using dialysis technique, prominent accumulation of norepinephrine (NE) in the myocardial interstitial space was observed under local administration of a monoamine oxidase inhibitor (pargyline, 10 mM), and a vesicle uptake inhibitor (reserpine, 10 microM). Accumulation of NE in the myocardial interstitial space was associated with a reduction of dihydroxyphenylglycol levels. Pretreatment with omega-conotoxin GVIA (10 microM) or desipramine (10 microM) did not suppress this response. A brisk increase in dialysate NE levels might occur as a consequence of exocytotic or neurotransporter insensitive efflux of NE.

Adrenergic Fibers↗
PubMed1997

High-performance liquid chromatographic determination of myocardial interstitial dihydroxyphenylglycol.

This study describes a high-performance liquid chromatographic method with electrochemical detection (HPLC-ED) for monitoring dihydroxyphenylglycol (DHPG) in the myocardial interstitial space. Using a cardiac dialysis technique, 10-microl dialysates were sampled from the myocardial interstitial space (1-min fractions) and were injected directly into the HPLC-ED system. The in vitro quantification limit for DHPG was 250 fg in a 10-microl injection. The basal DHPG concentration of dialysate was 181+/-46 pg/ml. This system offers a new possibility for monitoring myocardial interstitial DHPG levels.

Animals↗
PubMed1997

A novel pentasaccharide sequence GlcA(3-sulfate)(beta1-3)GalNAc(4-sulfate)(beta1-4)(Fuc alpha1-3)GlcA(beta1-3)GalNAc(4-sulfate) in the oligosaccharides isolated from king crab cartilage chondroitin sulfate K and its differential susceptibility to chondroitinases and hyaluronidase.

Novel sulfated tetrasaccharide structures containing 3-O-sulfated GlcA were isolated recently from king crab cartilage chondroitin sulfate K [Sugahara, K., Tanaka, Y., Yamada, S., Seno, N., Kitagawa, H., Haslam, S. M., Morris, H. R., & Dell, A. (1996) J. Biol. Chem. 271, 26745-26754]. In this study, we prepared a series of oligosaccharides from the same source after exhaustive digestion with testicular hyaluronidase and determined the structures of a pentasaccharide, two hexasaccharides, and two heptasaccharides by means of fast atom bombardment mass spectrometry and 500-MHz 1H-NMR spectroscopy. All the oligosaccharides had the following hitherto unreported structures including a novel glucuronate 3-O-sulfate: GlcA(3S)(beta1-3)GalNAc(4S)(beta1-4)GlcA(3S)(beta1-3)GalNAc( 4S)(beta1-4)GlcA(beta1-3)GalNAc(4S), GlcA(3S)(beta1-3)GalNAc(4S)(beta1-4)GlcA(3S)(beta1-3)GalNAc( 4S)(beta1-4)GlcA(3S)(beta1-3)-GalNAc(4S), GlcA(3S)(beta1-3)GalNAc(4S)(beta1-4)(Fuc alpha1-3)GlcA(beta1-3)GalNAc(4S), GlcA(3S)(beta1-3)-GalNAc(4S)(beta1-4)(Fuc alpha1-3)GlcA(beta1-3)GalNAc(4S)(beta1-4)GlcA(beta1-3)GalNAc (4S), and GlcA(3S)(beta1-3)GalNAc(4S)(beta1-4)GlcA(3S)(beta1-3)GalNAc( 4S)(beta1-4)(Fuc alpha1-3)GlcA(beta1-3)GalNAc(4S), where 3S or 4S represent 3-O- or 4-O-sulfate, respectively. Furthermore, the three latter structures contained a novel combination of both 3-O-sulfated and 3-O-fucosylated GlcA residues. The pentasaccharide with 3-O-fucosylated GlcA at the internal position remained totally resistant to chondroitinase AC-II, whereas it was degraded by chondroitinase ABC into a disaccharide unit containing GlcA(3S) derived from the nonreducing side and a trisaccharide unit containing fucose from the reducing side.

Animals↗
PubMed1997

Long-term potentiation and depression in layer III and V pyramidal neurons of the cat sensorimotor cortex in vitro.

Synaptic plasticity of the cat sensorimotor cortex was examined intracellularly in vitro. After tetanic stimulation of the white matter, layer III and V pyramidal neurons showed long-term potentiation (LTP) of EPSPs in high incidence without GABA(A) antagonist. The incidence and magnitude of LTP were very conspicuous in layer V cells. After an NMDA receptor antagonist application, the synaptic potentiation was blocked completely in layer III but not in layer V cells. Long-term depression (LTD) of the evoked EPSPs was also induced by the same stimulation in some layer III cells, where a transient hyperpolarization of the membrane potential was observed during tetanus.

2-Amino-5-phosphonovalerate↗
PubMed1997

Intracortical facilitation and inhibition after transcranial magnetic stimulation in conscious humans.

1. Changes in excitability of the motor cortex induced by a transcranial magnetic stimulation (TMS) were examined by simultaneous recording of the evoked corticospinal volley and the compound surface electromyographic (EMG) response in the biceps brachii following paired-pulse TMS in five conscious subjects. The effects of a varying interstimulus interval (ISI) and a conditioning stimulus intensity were also investigated. 2. A submotor threshold conditioning stimulus inhibited the test responses at ISIs of 2-5 ms. A supramotor threshold conditioning stimulus inhibited the test responses at ISIs of 100-200 ms. Both of these inhibitions were prominent in late I waves. 3. There was a facilitation of the test responses at an ISI of 25 ms that was prominent in late I waves. The facilitation evoked by the supramotor threshold conditioning stimulus was more prominent than that evoked by the submotor threshold conditioning stimulus. 4. It is concluded that single TMS induced the triphasic changes of the motor cortex excitability in conscious humans that resulted in changes in EMG responses following paired TMS.

Adult↗
PubMed1997

Neurotrophin-3 expression in human pancreatic cancers.

Some neurotrophic factors stimulate process outgrowth in peripheral and/or central nerve fibres. There is no published report that has focused on the expression of neurotrophic factors in human pancreatic cancer except basic fibroblast growth factor. This study was therefore designed to examine the mRNA and protein levels of neurotrophin-3 (NT-3), which is one of the representative neurotrophic factors. The mRNA level for NT-3 was first investigated in eight pancreatic cancers and two samples of normal pancreas, using reverse transcription-polymerase chain reaction (RT-PCR). NT-3 protein expression was then studied in 47 human pancreatic cancers, using a monoclonal antibody against human NT-3 protein. There was a notable difference in the level of NT-3 mRNA between normal and pancreatic carcinoma tissues, with no evident difference in the expression of the beta-actin gene. Immunohistochemically, 34 of 47 pancreatic cancers (72 per cent) were mildly to markedly immunoreactive for NT-3 in the cytoplasma. Immunoreactivity was usually more pronounced at the infiltrative margins of the tumours. These observations suggest that pancreatic carcinoma overexpresses NT-3.

Adult↗
PubMed1997

A hemizygous A to CC base change of the CHM gene causing choroideremia associated with pinealoma.

BACKGROUND: Although mutations of the CHM gene have been reported in the Caucasian patients with choroideremia, there have been no such reports in non-Caucasian patients. We analyzed the CHM gene in a Japanese patient with choroideremia associated with pinealoma. METHODS: The method for screening was a nonradioisotopic modification of single-strand conformation polymorphism (SSCP) analysis. The PCR products from the patient and the carrier were screened and directly sequenced using an automated DNA sequencer. The PCR product of the carrier was also subcloned into a vector and the subcloned products were sequenced. RESULTS: SSCP analysis showed an identical abnormal band shift in the patient and the carrier. Direct sequence analysis showed a hemizygous A to CC mutation at nucleotide 1608 of the CHM gene in the patient, suspected to result in the absence or truncation of the predicted CHM protein. The sequence using both the PCR product and the subcloned DNA of the carrier showed both wild-type and mutant bands indicating a heterozygote. CONCLUSION: The hemizygous mutation was detected in a patient and the heterozygous pattern in his mother, the carrier, suggesting that this mutation caused the disease.

Adaptor Proteins, Signal Transducing↗
PubMed1997

Two cases of torsion of the gallbladder diagnosed preoperatively.

BACKGROUND: The authors experienced two cases of torsion of the gallbladder, both of which were correctly diagnosed preoperatively. METHODS: Two boys, aged 4 and 5 years, were transferred to Yokohama City Seibu Hospital because of their acute abdominal disorders. Diagnostic imaging demonstrated acute inflammatory changes in the gallbladder with an abnormal arrangement of the gallbladder and common bile duct in both cases. Laparotomy findings showed torsion of the gallbladder by 180 degrees and 360 degrees, respectively, at the cystic ducts, resulting in gangrenous change. RESULTS: Both children recovered uneventfully after cholecystectomy. The diagnostic imaging criteria are (1) collection of fluid between the gallbladder and the gallbladder fossa of the liver, (2) a horizontal rather than vertical arrangement of the long axis of the gallbladder, (3) the presence of a well-enhanced cystic duct located on the right side of the gallbladder, and (4) signs of inflammation including marked edema with thickening of the wall. CONCLUSIONS: The authors report the clinical characteristics of this uncommon condition, and discuss the significance of accurate preoperative diagnosis of these acute surgical disorders.

Child, Preschool↗