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Biomedical subjects

M Kagawa

Publications and source records attributed to M Kagawa.

At least 37 records · Page 2Linked to original sources
PubMed1997

Superior sagittal sinus thrombosis treated with combined local thrombolytic and systemic anticoagulation therapy.

We recently encountered a patient with thrombosis of the superior sagittal sinus of an idiopathic cause. The patient was treated initially with combined local thrombolytic therapy through the burr hole over the superior sagittal sinus and systemic anticoagulant therapy. Continuous ventricular drainage and hyperbaric oxygenation therapy were used to control the increased intracranial pressure. The superior sagittal sinus was successfully recanalized. Whereas the patient suffered a complication with subacute subdural haematoma, he was successfully treated with the combination of these therapies. The rationale and approach are discussed.

Anticoagulants↗
PubMed1997

Epitope-defined monoclonal antibodies against type-IV collagen for diagnosis of Alport's syndrome.

BACKGROUND: Alport's syndrome can be diagnosed by staining the alpha 5 chain of type IV collagen in kidney biopsy specimens with a monoclonal antibody. Because antibodies already established against the alpha 5 chain require denaturation treatment of cryostat sections to expose their epitopes. To save time and effort for staining, a new epitope-defined monoclonal antibody whose epitope is initially exposed on the surface of the molecule was established. METHODS: Two monoclonal antibodies against the triple-helical domains of the type IV collagen alpha 2 and alpha 5 chains were established with synthetic peptides as immunogens by the rat lymph node method. Their epitope were EAIQP at the positions of 675-679 of the alpha 2 chain, and IDVEF at the positions of 251-255 of the alpha 5 chain, respectively. They were purified with synthetic peptide-coupled affinity columns, and then conjugated with Texas red and FITC, respectively. RESULTS: The mixture of fluorochrome-conjugated antibodies was able to detect the distribution of the alpha 2 and alpha 5 chains in the normal and Alport kidney and skin by direct immunofluorescence staining with and without denaturation treatment of the sections. CONCLUSIONS: The direct double immunofluorescence staining of kidney and skin cryostat sections with the fluorochrome-conjugated antibodies is useful, reliable, and convenient for diagnosis of Alport's syndrome.

Amino Acid Sequence↗
PubMed1997

Current treatment of brain abscess in patients with congenital cyanotic heart disease.

OBJECTIVE: The goal of this study was to define clearly the role of management in patients with cyanotic heart disease and brain abscesses by evaluating retrospectively the factors influencing poor outcome in these patients. METHODS: This study included 62 patients with cyanotic heart disease and brain abscesses diagnosed in the computed tomography era. Basic characteristic parameters (number, size, location, computed tomographic classification and organism type of abscess, convulsion, type of cyanotic heart disease, age distribution, immunocompromised status, pretreatment neurological state, and intraventricular rupture of brain abscess [IVROBA]) and therapeutic parameters (type of antibiotics and duration of administration, steroid medication and therapeutic modalities, aspiration with or without cerebrospinal fluid drainage, total extirpation after aspiration, or primary extirpation and medical treatment) were evaluated as independent predictors of poor outcome (totally disabled state or death) by using univariate and multivariate logistic regression analysis. We also statistically estimated the possible causes of IVROBA and the multiplicity of brain abscess. RESULTS: Although there were no statistically significant correlations between patients with good and poor outcomes in regard to other basic characteristic and therapeutic parameters, patients with poor outcomes were older (P < 0.02), more frequently had IVROBA (P < 0.005), and had a higher frequency of neurological deterioration (P < 0.01) than those with good outcomes. Multiple logistic regression analysis predicted that poor outcome increased the relative risk of IVROBA by a factor of 18.9 (odds rate, 18.9; 95% confidence interval, 1.7-211.6; P < 0.02). More patients with multiple abscesses had positive immunocompromised states than those with single abscesses (P < 0.01). Deep-located abscesses also more frequently had IVROBA (P < 0.005) and abscesses located in the parieto-occipital region ruptured into the occipital horn of the lateral ventricle in a short period (P < 0.02). CONCLUSIONS: Our findings suggest that IVROBA strongly influences poor outcome in patients with cyanotic heart disease. The key to decreasing poor outcomes may be the prevention and management of IVROBA. To reduce operative and anesthetic risk in these patients, abscesses should be managed by less invasive aspiration methods guided by computed tomography. Abscesses larger than 2 cm in diameter, in deep-located or parieto-occipital regions, should be aspirated immediately and repeatedly, mainly using computed tomography-guided methods to decrease intracranial pressure and avoid IVROBA. IVROBA should be aggressively treated by aspiration methods for the abscess coupled with the appropriate intravenous and intrathecal administration of antibiotics while evaluating intracranial pressure pathophysiology.

Adolescent↗
PubMed1997

Normal distribution of collagen IV in renal basement membranes in Epstein's syndrome.

BACKGROUND: Epstein's syndrome is defined as a subtype of Alport's syndrome, and is distinguished from the other subtypes by accompanying macrothrombocytopenia. Mutations in collagen IV genes are known to be involved in the pathogenesis of typical Alport's syndrome. However, the presence of an underlying genetic defect has not been demonstrated in Epstein's syndrome. AIM: To clarify the involvement of collagen IV in Epstein's syndrome. METHODS: The distribution of the alpha(IV) chain was studied in renal specimens obtained from three patients with Epstein's syndrome using chain specific monoclonal antibodies and an antigen retrieval procedure. RESULTS: The patients showed a normal distribution of alpha(IV) chains: alpha 1(IV) and alpha 2(IV) were expressed ubiquitously, whereas expression of alpha 3(IV) through to alpha 6(IV) chains was limited to the glomerular basement membrane, Bowman's capsular basement membrane, and/or a portion of the tubular basement membrane. CONCLUSIONS: These results suggest that genes other than those encoding alpha(IV) chains are responsible for the pathogenesis of Epstein's syndrome.

Basement Membrane↗
PubMed1996

Species identification by the positional analysis of fatty acid composition in triacylglyceride of adipose and bone tissues.

In a new attempt at species identification, the total composition and positional distribution of fatty acid in triacylglyceride (TG) of adipose and bone tissues were analyzed in human, bovine, pig, dog, cat and chicken tissues. Although the total fatty acid compositions of bovine and pig tissues were significantly different from those of human (different in more than half the fatty acids tested), dog, cat and chicken tissues showed a comparatively similar composition to human fatty acids composed of TG in both tissues. The TG in these tissues was also subjected to stereospecific analysis using pancreatic lipase, that is, the fatty acid distribution in positions 1,3 (not distinguished between 1 and 3) and 2 of the TG were determined. The distribution of fatty acids among the positions 1,3 and 2 in the TG of animal adipose and bone tissues was non-random. The distribution between position 2 and positions 1,3 seems to be governed by chain length and unsaturation in each animal. The shorter and more unsaturated fatty acids showed a greater tendency to occupy position 2 of TG. Although this rule appeared in all animals except the pig, the distribution of each fatty acid into position 2 was species-specific. The positional distribution of fatty acid in TG was identical among the same species and in different regions of the same body. Thus, even when species identification is difficult using the pattern of total fatty acid composition, the analysis of the positional distribution of fatty acid makes it possible to determine the species. From the present results, the evaluation of positional distribution of fatty acid in the TG is a useful tool for the identification of human tissues.

Adipose Tissue↗
PubMed1996

Nephritogenicity and alpha-chain composition of NC1 fractions of type IV collagen from bovine renal basement membrane.

Nephritogenicity (anti-GBM-nephritis-inducing activity) and alpha-chain composition of globular-do-main (NCI) fractions of type IV collagen from bovine renal, pulmonary, and placental basement membranes (BMs) was examined by injecting these fractions with adjuvant into WKY/NCrj rats and by Western blotting using epitope-defined monoclonal antibodies to the six different alpha chains of type IV collagen. A purified nephritogenic fraction from renal BM contained alpha 1-alpha 6(IV)NCI, whereas a non-nephritogenic fraction contained only alpha 1-alpha 2(IV)NCI. Renal and pulmonary NCI had strong nephritogenic activity: placental NCI had weak activity. The renal and pulmonary fractions contained alpha 1-alpha 6(IV)NCI, and the placental fraction had a large amount of alpha 1-alpha 2(IV)NCI and a very small amount of alpha 3-alpha 6(IV)NCI. Immunohistochemical study of bovine renal BM with the monoclonal antibodies revealed that bovine glomerular BM contained alpha 1-alpha 5(IV) chains, but not the alpha 6(IV) chain. The absence of alpha 6(IV) chain in glomerular BM in bovine and in humans indicates that alpha 6(IV) chain is not a target antigen of anti-GBM nephritis. Nephritogenicity is apparently a property of alpha 3-alpha 5(IV)NCI.

Animals↗
PubMed1996

Absence of alpha 6(IV) collagen in kidney and skin of X-linked Alport syndrome patients.

To identify the abnormalities of the type IV collagen alpha 6 chain, alpha 6(IV), in Alport syndrome, we examined renal and skin tissue using rat monoclonal antibodies against non-consensus amino acid sequences of alpha 6(IV). Immunofluorescence of normal human kidney and skin tissue revealed linear alpha 6(IV) staining in the basement membrane (BM) of Bowman's capsule, in some tubules, and also in the epidermal BM. Renal specimens from five male patients of four families with X-linked Alport syndrome showed no reactivity for alpha 6(IV) in Bowman's capsules and tubules. In these patients, alpha 1(IV) and alpha 2(IV) were normal, whereas alpha 3(IV), alpha 4(IV), and alpha 5(IV) were absent from the BMs of the kidney. In skin tissue of male patients, neither alpha 5(IV) nor alpha 6(IV) were detected. The epidermal BM of female heterozygotes with X-linked Alport syndrome showed a mosaic staining for alpha 5(IV) and alpha 6(IV). These findings indicate that, in addition to a disturbed alpha 3(IV)-alpha 4(IV)-alpha 5(IV) network, patients with X-linked Alport syndrome have abnormalities in alpha 6(IV) of the renal and epidermal BMs at the protein level.

Amino Acid Sequence↗
PubMed1996

Arginine vasopressin receptor antagonists for treatment of vasogenic brain edema: an experimental study.

Recent studies indicate that centrally released arginine vasopressin (AVP) facilitates brain water permeability in normal and pathological conditions. The effects of central administration of arginine vasopressin (AVP) receptor antagonists on vasogenic brain edema were studied in rats. V1 or V2 receptor antagonists were stereotactically injected into the lateral ventricle 10 min prior to or 1 h after cold brain injury. The injury resulted in significant increases in the mean water content of the lesion and the contralateral hemispheres by 1.15 and 0.38%, respectively. Twenty-four hours after injury, the brain water and sodium contents, the brain swelling, and plasma osmolality were measured. V1 receptor antagonist of 50 ng significantly decreased the brain water and sodium contents and the brain swelling in the adjacent cortex of the lesion without changes in serum osmolality. On the other hand, 5 ng of V1 receptor antagonist and V2 receptor antagonist had no effect on edema. The V1 receptor of AVP is thought to act predominantly on water permeability of the brain. Peptide therapy may become an additional tool for brain edema treatment.

Animals↗
PubMed1996

Adult moyamoya disease progressing from unilateral to bilateral involvement .

A 30-year-old female and a 38-year-old male developed "definite" moyamoya disease after presenting with "probable" moyamoya disease manifesting as ischemic stroke. Angiography at first presentation demonstrated unilateral involvement with normal contralateral findings. The cases were classified as adult type "probable" moyamoya disease according to the diagnostic criteria. Follow-up angiography demonstrated the occlusive lesions had become bilateral, satisfying the criteria for "definite" cases. Serial angiography is required in adults presenting with "probable" moyamoya disease manifesting as ischemic stroke.

Adult↗
PubMed1995

Establishment by the rat lymph node method of epitope-defined monoclonal antibodies recognizing the six different alpha chains of human type IV collagen.

A group of rat monoclonal antibodies recognizing the six different alpha chains of human type IV collagen have been established by our novel method. The method is designated the rat lymph node method in which enlarged medial iliac lymph nodes of a rat injected with an antigen emulsion via hind footpads are used as a source of B cells for cell fusion to produce hybridomas. The immunogens used were synthetic peptides having non-consensus amino acid sequences near the carboxyl termini of type IV collagen alpha chains. Hybridomas were screened both by ELISA with synthetic peptides and by indirect immunofluorescence with cryostat sections of human kidneys. Because the epitopes of all antibodies were determined by multipin-peptide scanning, they were confirmed to be isoform-specific. They are useful for identification of alpha chains of type IV collagen at the protein level in normal and abnormal conditions. The combined use of synthetic peptides as immunogens, the rat lymph node method as making monoclonal antibodies, and the multipin-peptide scanning as epitope mapping is found to be a strong tool for identification of peptides and proteins whose amino acid sequences are known or have been deduced.

Amino Acid Sequence↗
PubMed1995

Management of intracranial hemorrhage associated with anticoagulant therapy.

BACKGROUND: Intracranial hemorrhage may be a particularly devastating complication of anticoagulant therapy. Very few accounts have reported data on the duration of anticoagulant discontinuation following intracranial hemorrhage or the intensity of anticoagulation during treatment for it, although we must adequately manage such a complication. METHODS: We analyzed the management of warfarin-related intracranial hemorrhages in 27 patients with cardiac diseases. We evaluated the degree of anticoagulation using the thrombotest. Anticoagulants were stopped as soon as the diagnosis of intracranial hemorrhage was established by computed tomographic scan. RESULTS: Mechanical valve prosthesis patients, who required intensive long-term anticoagulant therapy, constituted the majority of our series (74.1%). Intraoperative hemostasis was brought under control despite low thrombotest values (13%-68%) at the time of surgery except for the acute subdural hematoma (SDH) patients with cerebral contusion. Early resumption of anticoagulant therapy (within 3 days) did not cause intracranial rebleeding in any operative patient. All the chronic SDH patients and some of the subcortical hematoma patients had a good outcome. All three patients with acute SDH and contusion, however, had a fatal outcome because of intracranial rebleeding within a short period of time or ineffective intraoperative hemostasis. CONCLUSIONS: The patients with anticoagulant-related intracranial hemorrhage may undergo surgery with thrombotest values approximately between 20% and 60%, and anticoagulants can be resumed after an interval of 3 days. Aggressive surgery should particularly be performed in patients with anticoagulation-related chronic SDH or subcortical hemorrhage, as in the cases of anticoagulant-unrelated intracranial hemorrhage.

Adolescent↗
PubMed1995

Differential expression of two basement membrane collagen genes, COL4A6 and COL4A5, demonstrated by immunofluorescence staining using peptide-specific monoclonal antibodies.

Genes for the human alpha 5(IV) and alpha 6(IV) collagen chains have a unique arrangement in that they are colocalized on chromosome Xq22 in a head-to-head fashion and appear to share a common bidirectional promoter. In addition we reported a novel observation that the COL4A6 gene is transcribed from two alternative promoters in a tissue-specific manner (Sugimoto, M., T. Oohashi, and Y. Ninomiya. 1994. Proc. Natl. Acad. Sci. USA. 91:11679-11683). To know whether the translation products of both genes are colocalized in various tissues, we raised alpha 5(IV) and alpha 6(IV) chain-specific rat monoclonal antibodies against synthetic peptides reflecting sequences near the carboxy terminus of each noncollagenous (NC)1 domain. By Western blotting alpha 6(IV) chain-specific antibody recognized 27-kD monomers and associated dimers of the human type IV collagen NC1 domain, which is the first demonstration of the presence in tissues of the alpha 6(IV) polypeptide as predicted from its cDNA sequence. Immunofluorescence studies using anti-alpha 6(IV) antibody demonstrated that in human adult kidney the alpha 6(IV) chain was never detected in the glomerular basement membrane, whereas the basement membranes of the Bowman's capsules and distal tubules were positive. The staining pattern of the glomerular basement membrane was quite different from that obtained with the anti-alpha 5(IV) peptide antibody. The alpha 5(IV) and alpha 6(IV) chains were colocalized in the basement membrane in the skin, smooth muscle cells, and adipocytes; however, little if any reaction was seen in basement membranes of cardiac muscles and hepatic sinusoidal endothelial cells. Thus, both genes are expressed in a tissue-specific manner, perhaps due to the unique function of the bidirectional promoter for both genes, which is presumably different from that for COL4A1 and COL4A2.

Adipocytes↗
PubMed1995

A novel method of preparing rat-monoclonal antibody-producing hybridomas by using rat medial iliac lymph node cells.

A novel method of preparing hybridomas producing rat monoclonal antibodies was established. The enlarged medial iliac lymph nodes from rats injected via hind footpads with an emulsion of antigen and Freund's adjuvant were used for cell fusion. Ovalbumin was used as a representative antigen. The incidence of hybridomas producing antibody of interest with this method was about 10 times higher than that of hybridomas with the conventional method using mouse or rat spleen cells. The average percentages of hybridomas producing IgG1, IgG2a, IgG2b and IgG2c were 37.1%, 47.0%, 15.9% and 0.0%, respectively. A single injection with antigen was sufficient for immunization in this method.

Animals↗
PubMed1995

[Studies on factors influencing the attack of subarachnoid hemorrhage during labor].

We analyzed factors affecting attacks of subarachnoid hemorrhage (SAH) retrospectively in 411 patients and studied the relation of the attacks with labor. The onset time of SAH has two peaks of the time: one is 7:00 a.m. and the other is between 16:00 and 17:00 in the afternoon. The attacks of SAH during labor were observed in 15.1% of all the patients. It was noted that 66.7% of all the attacks were observed at the time with certain external stress such as working, sporting, sexual intercourse, etc. The number of patients who suffered from attacks during labor with history of hypertension and insomnia were not significantly different compared with those suffered from attacks during other activities, but 40-59 aged men those who have a history of smoking were significantly more in number compared with those that suffered attacks during other activities. Transient increase of blood pressure due to external stress is suggested as an initiative factor of the bleeding during working. Reactivity of the individuals against physical and mental stress (external stress) might be considered to be the major problem, although it remains not to be unexplained whether labor itself participates in the onset of SAH. Regarding the prevention of SAH during labor, new methods of medical examination and health control is required.

Adult↗
PubMed1994

Intrathecal neuromedin C enhances mechanical nociception: possible involvement of NMDA receptors.

Intrathecal administration of neuromedin C (3, 10 nmol/rat) significantly decreased the nociceptive threshold of rats in the paw-pressure test. This effect was abolished by co-administration of [Leu13 psi(CH2NH)-Leu14]bombesin (10 nmol/rat), a bombesin receptor antagonist. Co-administration of 2-amino-5-phosphonovaleric acid (APV) at a dose (10 nmol/rat) which did not affect the nociceptive threshold by itself significantly inhibited the effect of neuromedin C. 6-Cyano-7-nitroquinoxaline-2,3-dione (CNQX) (10 nmol/rat) did not significantly inhibit the neuromedin C-induced hyperalgesia. These results indicate that neuromedin C could modulate mechanical nociception through bombesin receptors at the spinal level, where glutamate is involved through NMDA receptors.

2-Amino-5-phosphonovalerate↗
PubMed1994

A fatal disaster case based on exposure to hydrogen sulfide--an estimation of the hydrogen sulfide concentration at the scene.

Four adult men fell into an artificial lake which was being used to raise flatfish, after a water pipe had been connected to a tube allowing seawater to flow into the lake. Forensic autopsies were carried out on three of the four men, who died soon after the incident. From autopsy findings, the cause of death was diagnosed to be suffocation after aspirating seawater in the three victims. To clarify why the men fell into the lake, a chemical analysis for hydrogen sulfide was carried out using the extractive alkylation technique combined with gas chromatography/mass spectrometry. The sulfide was detected as its derivative, bis(pentafluorobenzyl)sulfide, in body tissues taken from all the victims, and the concentration of hydrogen sulfide gas at the scene was estimated as having been nearly fatal.

Adult↗