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Biomedical subjects

K Ohmori

Publications and source records attributed to K Ohmori.

At least 19 recordsLinked to original sources
PubMed1995

Jararhagin and jaracetin: novel snake venom inhibitors of the integrin collagen receptor, alpha 2 beta 1.

Two novel proteins, jararhagin and jaracetin, were purified from Bothrops jararaca viper venom. Jararhagin is a 55-kDa member of the metalloprotease-disintegrin family. Jaracetin is a 60-kDa dimer representing a differently processed form of jararhagin. Like botrocetin, a previously described viper venom protein, jararhagin and jaracetin modulated binding of von Willebrand Factor to the glycoprotein Ib-IX complex on platelets through a specific interaction with the von Willebrand Factor A1 domain. Both jararhagin and jaracetin, but not botrocetin, also blocked alpha 2 beta 1-dependent platelet adhesion to collagen, a receptor interaction mediated through a homologous A domain on the integrin alpha 2 subunit.

Animals↗
PubMed1995

Chronic effect of oral mexiletine administration on left ventricular contractility in patients with congestive heart failure: a study based on mitral regurgitant flow velocity measured by continuous-wave Doppler echocardiography.

The long-term effect of mexiletine on left ventricular (LV) contractility in patients with congestive heart failure is not clear. The authors therefore measured LV contractility before and after continuous oral administration of mexiletine in patients with congestive heart failure accompanied by mitral regurgitation (MR) using Doppler echocardiography. The study population consisted of 8 patients with congestive heart failure (6 due to dilated cardiomyopathy and 2 due to old myocardial infarction) accompanied by significant functional MR who had more than 1000 ventricular premature contractions (VPCs) per day or Class IV Lown classification arrhythmias before mexiletine administration. The LV contractility was evaluated by calculating a Doppler-derived index, the rate of increase in LV pressure during the isovolumic contraction time (ICT delta P/delta t), which has been confirmed to be nearly equal to LV Max dP/dt. The increase in LV pressure (delta P) between 1 and 3 m/sec of the MR flow velocity as measured by continuous-wave Doppler echocardiography was calculated using the simplified Bernoulli's equation, and ICT delta P/delta t was derived by dividing delta P by the time required for this change. The left ventricular ejection fraction and the left ventricular and left atrial dimensions also were measured by echocardiography. These parameters were obtained before and after 2 to 4 weeks of daily oral administration of mexiletine 300 mg. Values of ICT delta P/delta t were 640 +/- 202 mm Hg/sec and 650 +/- 210 mm Hg/sec before and after mexiletine administration, respectively, showing no change.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1995

A newly established megakaryoblastic/erythroid cell line that differentiates to red cells in the presence of erythropoietin and produces platelet-like particles.

In August, 1992, we established a leukemic cell line (NS-Meg) from a patient in megakaryoblastic transformation of Philadelphia chromosome-positive chronic myeloid leukemia. The NS-Meg cells were positive for alpha-naphthyl acetate esterase and periodic acid-Schiff (PAS) staining and for surface CD4, CD7, CD13, CD34, CD41a, and glycophorin A antigens. Ultrastructurally, the cells had alpha-granules, demarcation membranes, and platelet peroxidase activity. The NS-Meg cells spontaneously produced platelet-like particles which contained alpha-granules, mitochondria and dense bodies, strongly suggesting platelet production. Erythropoietin (Epo), granulocyte/macrophage colony stimulating factor(GM-CSF), and interleukin 3 (IL-3) promoted the growth of NS-Meg cells. Phorbol-12-myristate-13-acetate increased the expression of both CD41a and CD61 antigens. Ten-day exposure to Epo induced mature erythroblasts and red cells. These benzidine-positive cells were positive for hemoglobin F staining. Untreated NS-Meg cells expressed mRNA for the Epo receptor (EpoR), for GATA-1, and for alpha 1, alpha 2 and gamma globin genes. These results indicate that NS-Meg cells undergo terminal differentiation of both megakaryocytic and erythroid lineages. This cell line should be a very useful tool for the investigation of both megakaryocytic and erythroid maturation.

Adult↗
PubMed1995

Simultaneous carboplatin and radiotherapy for all stages of head and neck squamous cell carcinoma.

The study investigated the toxicity and efficiency of the concomitant administration of radiotherapy and carboplatin to patients with head and neck carcinomas. Sixty-three patients with head and neck squamous cell carcinomas, other than nasopharyngeal cancer and Stage I (UICC) laryngeal cancers, were treated by external radiotherapy and four courses of carboplatin at a dose of 100 mg/m2 per week. In two patients, only three courses were possible due to renal toxicity. In the other 61 patients, toxicities were self-limiting and no patient required interruption of carboplatin administration. No patient required discontinuation of radiotherapy because of acute toxicity. Of 61 evaluable patients, a complete response (CR) was obtained in 11.5% and a partial response (PR) in 60.7% at 40 Gy. In 41 patients treated to 65 Gy (including two patients with maxillary sinus carcinoma, who were treated by debulking surgery), CR was obtained in 76.9% and CR+PR was 100% at the end of treatment. The actuarial survival rate of the 63 patients at 2 years was 69.2%, with a median follow-up period of 24.4 months. One of 12 patients who received salvage surgery after radical radiotherapy has died due to poor wound healing after the surgery. The schedule was safe, providing a weekly check of serum samples was possible. It is likely that the rate of local control and vocal cord preservation in laryngeal tumours might improve if concurrent carboplatin is used. Careful follow-up is required to determine the long-term effect of concomitant carboplatin administration.

Adult↗
PubMed1995

Harvest of sural nerve grafts using the endoscope.

Endoscopic surgical techniques were employed in 5 patients to harvest the sural nerve atraumatically with a minimal number of skin incisions. The medial sural nerve was harvested by two 2-cm-wide transverse incisions made under endoscopic-magnified visualization, which allowed the surgeon to see the detailed structure of the nerve and surrounding tissue. This method requires minimal traction of the nerve during nerve dissection, and postoperative pain and swelling were less than encountered with conventional methods, because the method we have employed is less invasive and atraumatic.

Endoscopy↗
PubMed1995

Retroauricular hairline flap transfer to the face.

For facial skin defects including the hair-bearing area of preauricle-sideburn, lateral forehead-temporal hairline, and upper eyelid-eyebrow region, the transfer of a hairline flap that incorporates a skin flap is one option available for creating a natural hairline. An island or free retroauricular hairline flap (retroauricular skin flap including retroauricular hairline) based on the superficial temporal vessels or posterior auricular vessels was used to reconstruct facial skin defects including hair-bearing areas in seven patients. All flaps "took" perfectly, and aesthetically satisfactory results were achieved with minimal donor-site morbidity. However, flap vessels must be selected with great care during the surgical procedure because of the anatomic variation found among patients in the positions of the superficial temporal and posterior auricular vessels.

Adult↗
PubMed1995

Versatility of a microsurgical free-tissue transfer from the forearm in treating the difficult nose.

Ten selected patients with nasal defects in the covering, lining, or framework were treated by a vascularized free-tissue transfer from the forearm. A vascularized skin flap, fascia, and split radius were transferred in accordance with the shape of the defects. All flaps "took" perfectly, and satisfactory results were obtained. The grafted bones were stable over a follow-up period ranging from 1 to 6 years; however, some problems did arise in the course of treatment, including poor matches between the flap and surrounding facial skin, postoperative drooping of the flap used in the lining, and conspicuous donor sites. However, despite these drawbacks, microvascular free-tissue transfer from the forearm has proven to be a good choice for the restoration of a nose that is difficult to reconstruct by more conventional methods.

Adolescent↗
PubMed1995

Tumor cell attachment to laminin promotes degradation of the extracellular matrix and cell migration in high-metastatic clone cells of RCT sarcoma in vitro.

We investigated the roles of extracellular matrix proteins, laminin and fibronectin, in promoting invasiveness through the extracellular matrix in high-metastatic [RCT(+)] clone cells established from poorly differentiated murine RCT sarcoma in C3H/He mice. Laminin stimulated the type IV collagenolytic activity of RCT(+) cells. After more than 6 h of incubation, the type IV collagenolysis of the cell-conditioned medium was significantly higher in laminin-treated groups compared with the control. The migration activity of RCT(+) cells was stimulated by laminin. However, fibronectin did not influence the type IV collagenolysis or cell migration in this clone cell. The amino acid sequence YIGSR, which is derived from laminin, inhibited the laminin-mediated cell attachment and the laminin-promoted type IV collagenolysis, as well as cell migration of RCT(+) cells. RGD derived from fibronectin did not influence the cell attachment to laminin or Matrigel in this clone. In the invasion assay employing a Matrigel coated filter in a Boyden chamber, YIGSR showed greater inhibition of invasion through the Matrigel than did RGD with RCT(+) cells. YIGSR might inhibit the promoted-matrix degradation and cell migration in response to the cell attachment to laminin by competing with laminin for binding to cell surface laminin receptor. We suggest that laminin-mediated cell attachment to the extracellular matrix may play a role in promoting the matrix degradation and cell migration during metastatic cascades.

Amino Acid Sequence↗
PubMed1995

Effect of oxatomide nasal spray on experimental allergic rhinitis in guinea pigs and rats.

We investigated the effect of topically applied oxatomide, an antiallergic agent, on the assault of allergic rhinitis in actively sensitized guinea pigs. Topical application of oxatomide nasal spray (0.025%) reduced the severity of allergic rhinitis which was assessed by determining dye leakage and histamine released to the nasal cavity of guinea pigs. Furthermore, oxatomide nasal spray treatment significantly prevented the increase in dye leakage induced by histamine administration in guinea pigs and rats. These results indicate that the topical application of oxatomide inhibits both the release and the action of histamine. Therefore, oxatomide nasal spray may be beneficial for treatment of allergic rhinitis.

Administration, Intranasal↗
PubMed1995

Cerebral infarction in a young adult associated with protein C deficiency. A case report.

Protein C deficiency is a cause of thromboembolic disease. Venous thrombosis is the most common clinical manifestation. Arterial thrombosis is unusual and involvement of the intracranial arteries is especially rare. Herein the authors describe a case of cerebral [correction of cerebellar] infarction associated with protein C deficiency and review the relevant medical literature. A thirty-year-old man was hospitalized because of dysarthria, right limb ataxia, and a gait disturbance. Cranial computed tomography disclosed an infarction in the right cerebellar hemisphere and brachium pontis. Three months earlier the patient had had a transient ischemic attack with truncal ataxia and gait disturbances. On admission, the protein C antigen was 57% and protein C activity was 45%. Investigation of family members revealed protein C deficiency in an uncle. Literature review of stroke cases associated with protein C deficiency revealed that most had had a previous vascular event and/or a positive family history or had used oral contraceptives chronically. Protein C deficiency should be considered in young stroke patients with a positive family history of vaso-occlusive disease, previous ischemic events, or chronic oral contraceptive use.

Adult↗
PubMed1995

Subclavian steal phenomenon associated with stress polycythemia. A case report.

A case of stress polycythemia without symptoms of cerebral ischemia is presented. The patient demonstrated a blood flow reversal through the right vertebral artery that was caused by a complete obstruction of the right subclavian artery at its origin. This obstruction may have been due to thrombosis associated with stress polycythemia. This is a rare example of a case in which thrombotic complications of stress polycythemia occurred in a larger caliber vessel such as the subclavian artery.

Humans↗
PubMed1995

Urine C-peptide and atherogenic risk factors in diabetes mellitus: relevance to "syndrome X".

The relation between the C-peptide concentration in twenty-four-hour urine specimens and atherogenic risk factors was investigated in 38 patients with noninsulin-dependent diabetes mellitus in an attempt to determine the significance of urine C-peptide in diagnosing "syndrome X," which is characterized by insulin resistance. Weak positive correlations between twenty-four-hour urine C-peptide concentration and body mass index, systolic blood pressure (BP), diastolic BP, serum total cholesterol, and serum triglyceride were detected. A weak negative correlation was also apparent between urine C-peptide and serum high-density lipoprotein (HDL). The body mass index and serum triglyceride of patients with urine C-peptide excretion of > 100 micrograms/day were significantly higher than those in patients with normal urine C-peptide excretion (< 100 micrograms/day) (P < 0.01 and P < 0.02, respectively). Systolic BP, diastolic BP, serum total cholesterol, and serum HDL did not differ significantly between the two groups of patients. Results indicate that twenty-four-hour urine C-peptide concentration is of significance in determining whether a patient has a tendency to insulin resistance but has only limited value as a quantitative measure of endogenous insulin secretion.

Adult↗
PubMed1995

Gadolinium-enhanced magnetic resonance imaging of meningeal carcinomatosis in colon cancer.

Meningeal carcinomatosis has been infrequently reported in colorectal carcinoma. Recently the value of gadolinium-enhanced magnetic resonance imaging (MRI) in the examination of this disease has been described. We report a 55-year-old man with meningeal carcinomatosis from a known colon cancer. In this case, a gadolinium-enhanced MRI of the brain showed enhancing dura and nodular lesions which were not detected by enhanced computed tomography. The gadolinium-enhanced MRI may serve as an indicator of leptomeningeal involvement and may be a useful test in addition to the evaluation of cerebrospinal fluid cytology and chemistry.

Carcinoma↗
PubMed1995

Vertebral slip in lumbar spondylolysis and spondylolisthesis. Long-term follow-up of 22 adult patients.

We studied the aetiology of vertebral slip in a long-term follow-up of 22 adult patients with isthmic spondylolysis or spondylolisthesis of L5. Of the 18 with spondylolysis without slip, 13 showed no slip after ten years, but five developed displacement of over 5%. All four patients with spondylolisthesis showed progression of the slip. We found that the vertical thickness of the transverse process of L5 was significantly greater (p < 0.01) in the 13 patients with no slip than in the other two groups. The relationship of vertebral slip to the shape of the transverse processes of L5 may be explained by differences in the bulk or physiological strength of the posterior bands of the iliolumbar ligament.

Adolescent↗
PubMed1994

Variant type of sialyl Lewis X antigen expressed on adult T cell leukemia cells is associated with skin involvement.

Expression of a variant type of sialyl Le(x) antigen defined by 2F3 monoclonal antibody on leukemia cells was studied in 15 adult T cell leukemia (ATL) patients. The expression of 2F3-defined sialyl Le(x) antigen on CD4+CD45+ cells, which is an ATL cell-rich population, was higher in patients with skin involvement (50.1 +/- 23.1% were positive) than in patients without skin involvement (18.1 +/- 12.5%) (P < 0.01). The other surface markers including classical sialyl Le(x) antigen defined by SNH3 or FH6 and LFA-1, VLA-4, CD4, CD25, ICAM-1, Leu8, and HLA-DR did not show a significant difference regardless of skin involvement. In the skin lesion of four patients that we could examine, infiltrating leukemia cells strongly expressed 2F3-defined sialyl Le(x) antigen. In one patient, we could also examine the expression of classical sialyl Le(x) antigen defined by SNH-3 and CSLEX-1, but this was almost negligible. Both skin and lymph node biopsy specimens were examined in two patients. Leukemia cells in the skin strongly expressed 2F3-defined sialyl Le(x) antigen, while its expression was almost negligible on the leukemia cells in the lymph node. These findings suggest that the expression of 2F3-defined sialyl Le(x) antigen on ATL cells is associated with skin involvement of ATL.

Adult↗
PubMed1994

Monoclonal antibodies distinctively recognizing the subtypes of inositol 1,4,5-trisphosphate receptor: application to the studies on inflammatory cells.

Monoclonal antibodies were raised that specifically recognize the COOH-terminal sequences and the loop sequences between the fifth and the sixth transmembrane spanning regions of human inositol 1,4,5-trisphosphate receptor (IP3R) type 1, 2 and 3. Western blot analysis using Jurkat cells, mouse cerebellum, COS-7 expressing IP3R type 3 cDNA showed that those monoclonal antibodies reacted specifically with each of these three IP3R subtypes and that they do not cross-react. These antibodies could be used for the specific immunoprecipitation of IP3Rs. Using these monoclonal antibodies, the expression profiles of IP3R-subtype proteins were found to be different among inflammatory cells such as macrophages, polymorphonuclear cells, mast cells, eosinophils, splenocytes, thymocytes and megakaryocytic cells. Usually, more than one type of IP3R were expressed in a cell simultaneously. The observation of CMK cells under immunofluorescence confocal microscopy revealed that IP3R type 1 and type 2 are located at different subcellular fractions.

Amino Acid Sequence↗