Biomedical subjects

M Ohiwa

Publications and source records attributed to M Ohiwa.

At least 19 recordsLinked to original sources

PubMed1999

Laparoscopic partial adrenalectomy.

BACKGROUND: Most laparoscopic adrenalectomies involve total removal of the whole adrenal gland, and reports of laparoscopic partial adrenalectomies have been very few. The criteria for performing a laparoscopic partial adrenalectomy have not been described. METHODS: (a) Patients with functioning adrenal tumors smaller than 3 cm in diameter were selected. (b) The solitary adrenal tumors were evaluated by preoperative thin-slice computed tomography (CT) scan. (c) Solitary lesions were reconfirmed with intraoperative ultrasonography. (d) Partial adrenalectomy was performed with at least a 5-mm margin using a vascular stapler. RESULTS: Laparoscopic partial adrenalectomy was performed in five patients using the vascular stapler. Hemostasis was perfect in all five patients. The tumor was located in the inferior part of the right adrenal gland in three cases and in the upper pole of the left adrenal gland in two cases. The postoperation pathologic diagnosis was adrenocortical adenoma in all five patients, and excessive hormonal levels or symptoms all disappeared. CONCLUSIONS: Laparoscopic partial adrenalectomy can be performed safely using a vascular stapler.

Adenoma↗

PubMed1999

A case-controlled study of laparoscopic compared with open lateral adrenalectomy.

BACKGROUND: Few studies have been done regarding laparoscopic transperitoneal lateral adrenalectomy compared with open transretroperitoneal lateral adrenalectomy in a case-controlled fashion. METHODS: A case-controlled study of 40 laparoscopic and 40 open adrenalectomies was done in patients who were matched for age, gender, endocrine disorder, side and size of tumor, and area of body surface. Follow-up was complete in 92.5% of the patients, with a mean follow-up period of 30 months. RESULTS: Statistically significant differences (P <0.05) were present (laparoscopic versus open) when the following results were compared: estimated blood loss (40 g versus 172 g), operating time (147 versus 79 minutes), analgesic equivalents (2.9 versus 5.2 times), hospital stay (12 versus 18 days), and late morbidity (0% versus 47.5%). There were no statistically significant differences between the laparoscopic and open groups with regard to time to oral intake, time to walking, intraoperative and early complications, and total cost. CONCLUSIONS: Laparoscopic adrenalectomy is a safe technique that results in greater patient comfort, decrease in estimated blood loss, and earlier discharge than open adrenalectomy, with no increase in cost. It should be adopted as the technique of choice for the removal of functioning adenomas and for adrenal masses less than 6 cm in diameter.

Adenoma↗

PubMed1997

Characterization of Ret-Shc-Grb2 complex induced by GDNF, MEN 2A, and MEN 2B mutations.

We analyzed the intracellular signalling pathway through Ret activated by glial-cell-line-derived neurotrophic factor (GDNF), multiple endocrine neoplasia (MEN) 2A and 2B mutations. The results showed that all of them induce a signal transducing complex consisting of Ret, Shc, and Grb2 proteins. In addition, GDNF clearly activated a Ras-MAPK pathway in human neuroblastoma cells. Rat is expressed mainly as two isoforms that differ in the carboxy-terminal sequence: a long isoform (1114 amino acids) and a short isoform (1072 amino acids). The long isoform contains the consensus sequence for binding of the Shc PTB domain but not of its SH2 domain, whereas the short isoform has the consensus sequences for binding of both domains. In vitro binding assay revealed that the long isoform of the MEN2A-Ret protein and both isoforms of the MEN2B-Ret protein bound preferentially to the Shc PTB domain. On the other hand, the short isoform of MEN2A-Ret bound to the PTB and SH2 domains. In neuroblastoma cells expressing both isoforms of Ret, its activation by GDNF also resulted in the binding of both domains. GDNF and MEN 2A mutations activate Ret by inducing its dimerization, whereas the MEN 2B mutation increases Ret catalytic activity without dimerization. Our results thus suggest that Ret dimerization might be required for binding of the Shc SH2 domain to the short isoform.

3T3 Cells↗

PubMed1996

Detection of ret homodimers in MEN 2A-associated pheochromocytomas.

Using transfection of NIH 3T3 cells, we have recently demonstrated that multiple endocrine neoplasia (MEN) 2A mutations activate the c-Ret protein by inducing its disulfide-linked homodimerization on the cell surface. To investigate whether the homodimers are present in original tumors, the expression of the c-Ret protein was analyzed in eight sporadic and two MEN 2A-associated pheochromocytomas, the latter two of which contained mutations in cysteine 618 or 634 of Ret. The c-Ret protein was expressed at variable levels in all pheochromocytomas examined. By labeling the c-Ret protein immunoprecipitated from tumor tissues with [gamma-32P]ATP in vitro, its homodimers were detected in pheochromocytomas from MEN 2A patients but not in a sporadic tumor. This result represents the first demonstration of Ret homodimers in original tumors.

Drosophila Proteins↗

PubMed1994

Elevated plasma tissue factor antigen level in patients with disseminated intravascular coagulation.

The plasma tissue factor (TF) antigen level was measured in patients with disseminated intravascular coagulation (DIC). The plasma TF antigen was detected in normal volunteers, and it was significantly higher in DIC patients than in non-DIC patients. However, in some patients with DIC, the plasma TF antigen level was within the normal range. The plasma TF antigen level in patients with DIC significantly decreased after therapy, but it was not correlated with organ failure or outcome. The plasma TF antigen level in patients with DIC was not correlated with other hemostatic markers. The plasma TF antigen level tended to be higher in DIC patients with nonlymphoid leukemia than in those with lymphoid tumor. TF might be implicated in the occurrence and progression of DIC.

Antigens↗

PubMed1994

Increased activated protein C-protein C inhibitor complex levels in patients with pulmonary embolism.

Activated protein C (APC)-protein C inhibitor (PCI) complex level was examined in 35 patients with acute pulmonary embolism (PE) and in 20 healthy volunteers. Thrombin-antithrombin III complex, plasmin alpha 2 plasmin inhibitor complex, and fibrin-D-dimer levels were significantly increased in the patients with PE compared to levels in healthy volunteers. Levels of plasminogen activator inhibitor-I, tissue type plasminogen activator, and von Willebrand factor antigens were also significantly increased in patients with PE. Plasma level of APC-PCI complex was increased in most patients with PE and APC-alpha 1 antitrypsin complex level was increased in 13 patients. These complexes were not detected in healthy volunteers. These findings suggested that plasma protein C was activated in patients with PE, and that PCI was the major inhibitor of APC generated in this condition. Thus, regulation of the protein C pathway might play an important role in the pathogenesis of PE.

Adult↗

PubMed1994

Factor VII Mie: homozygous asymptomatic type I deficiency caused by an amino acid substitution of His (CAC) for Arg(247) (CGC) in the catalytic domain.

We found hereditary factor VII deficiency in a clinically asymptomatic family, and characterized their factor VII gene and the abnormal molecule using recombinant DNA techniques. The propositus was a 45-year-old woman who was noted to have a prolonged prothrombin time. The level of factor VII antigen of the patient was 25.9% of that of normal individuals and the level of factor VII activity was 28% and 24%, when tested using rabbit brain tissue factor and human placental tissue factor in a one-stage clotting assay, respectively. Two of her sisters had almost the same reduced levels of factor VII antigen and activity, and her parents who are first cousins, a son, a daughter and a niece had moderately reduced leves of both factor VII activity and antigen. To identify the mutation site, all the coding exons and exon-intron boundaries of the factor VII gene of the propositus were amplified using the polymerase chain reaction (PCR), then subcloned and sequenced. One missense mutation (G to A) was identified in exon VII of the gene resulting in an amino acid substitution of His(CAC) for Arg(247)(CGC) in the gene product. PCR using a mutagenic primer to introduce a new ApaL I site into the mutant allele of the patient's factor VII gene revealed that this allele was inherited in the affected individuals in the pedigree. Transient expression assays using BHK cells transfected with an expression vector containing the mutant factor VII cDNA suggested that this mutation leads to factor VII deficiency by impairing secretion of the mutated factor VII.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Sequence↗

PubMed1993

A compound heterozygous protein C deficiency with a single nucleotide G deletion encoding Gly-381 and an amino acid substitution of Lys for Gla-26.

We report genetic abnormalities of protein C gene in a male infant who developed neonatal purpura fulminans. DNA-sequence analysis of all exons in protein C gene in this family revealed two mutations. The first abnormality, derived from the mother, was a deletion of one of four consecutive G at nucleotide number 10758 in exon IX which would result in a frame shift mutation and completely change amino acid sequence from Gly381 in the carboxyl-terminal region of protein C. The second abnormality, derived from the father, was a single nucleotide mutation from G to A in the codon (GAG to AAG) at nucleotide number 2977 in exon III, which would result in a substitution of Lys for gamma-carboxyglutamic acid (Gla)26. This change would be responsible for the reduced immunological protein C levels of the patient and the father, estimated by a monoclonal antibody which recognizes the Gla-domain in a Ca(2+)-dependent manner (3.8% and 57%, respectively). Partially purified abnormal protein C from the father's plasma showed a normal amidolytic activity and a change in the electrophoretic mobility. We detected the above mutations in his family members using two methods; one was a creation of new restriction enzyme sites using mutagenic primers and the other was single nucleotide primer extension. Both methods are rapid and useful for the diagnosis of prenatal protein C abnormalities.

1-Carboxyglutamic Acid↗

PubMed1993

Plasminogen activators and their inhibitors in leukemic cell homogenates.

Plasminogen activator (PA) and PA inhibitor (PAI) were measured in homogenates of leukemia cells. Both PA and PAI levels were higher in non-lymphoblastic leukemia than in lymphoblastic leukemia. The levels were below the sensitivity of determination in chronic myelocytic leukemia (CML) but showed significant increases in blast crisis (CML,bc). The level of the tissue type PA (t-PA) antigen was highest in acute myeloblastic leukemia (AML) and that of the urokinase type PA (u-PA) was highest in acute promyelocytic leukemia (APL). The PAI-I antigen showed no marked cell specificity, but the PAI-II antigen was markedly increased in myelomonocytic leukemia and acute monocytic leukemia (AMoL). From these findings, various PAs and PAIs are considered to be present in leukemia cells and to be involved in hemostatic disorders, thus they are of diagnostic value in leukemia.

Blood Cells↗

PubMed1993

Hemostatic study before onset of disseminated intravascular coagulation.

Early diagnosis is necessary for the treatment of disseminated intravascular coagulation (DIC), but criteria for the stage preceding the diagnosis of DIC (pre-DIC) have not yet been established. To clarify hemostatic abnormalities that occur before the onset of DIC, we performed hemostatic studies in 117 patients within at least a week before the onset of DIC (pre-DIC), in 237 patients with DIC, and in 50 patients without DIC or pre-DIC (non-DIC). Levels of FDP, PT, and fibrinogen, and platelet counts were significantly abnormal after the onset of DIC, but not before. Thrombin-antithrombin III complex (TAT), plasmin-alpha 2 plasmin inhibitor complex (PIC), and FDP-D-dimer levels were significantly higher before the onset of DIC compared to the non-DIC patients. Hemostatic abnormalities were observed within a week before the onset of DIC. Monitoring the plasma levels of TAT, PIC, and FDP-D-dimer might be useful for the diagnosis of a pre-DIC condition.

Antithrombin III↗

PubMed1993

Increased vascular endothelial cell markers in patients with disseminated intravascular coagulation.

We examined vascular endothelial cell markers, thrombomodulin (TM), plasminogen activator inhibitor-I (PAI-I), tissue plasminogen activator (t-PA), and von Willebrand factor, in 80 patients with disseminated intravascular coagulation (DIC). The levels of thrombin-antithrombin III complex (TAT), plasmin-alpha 2 plasmin inhibitor complex (PIC) and FDP-D-dimer were significantly increased both before and after the onset of DIC, but were not correlated with organ failure or prognosis. However, the PIC/TAT ratio was lower in patients with poor prognosis than in those with good prognosis, and it was also lower in those with organ failure than in those without. Plasma TM, PAI-I, and t-PA levels were increased in DIC patients with organ failure or poor outcome, but were not significantly increased before the onset of DIC. We consider that the prognosis of patients with DIC might be related to organ failure or endothelial cell damage and that plasma levels of TM, PAI-I, and t-PA might be useful in the detection of these disorders and in assessing prognosis. A hypofibrinolytic state might enhance organ failure in patients with DIC.

Antifibrinolytic Agents↗

PubMed1993

Increased levels of vascular endothelial cell markers in thrombotic thrombocytopenic purpura.

We found that patients with thrombotic thrombocytopenic purpura (TTP) have significantly elevated plasma thrombin antithrombin III complex (TAT) and FDP-D-dimer levels, while the plasmin-alpha 2 plasmin inhibitor complex (PIC) level was only slightly increased. The tissue-type plasminogen activator (t-PA) level was increased, but it was well correlated with the plasminogen activator inhibitor-I (PAI-I) level. These findings suggest that hypercoagulable and hypofibrinolytic states coexist in these patients, in contrast to patients with disseminated intravascular coagulation, who exhibit coexisting hypercoagulable and hyperfibrinolytic states. Levels of vascular endothelial cell markers, such as PAI-I, thrombomodulin (TM), and t-PA, were increased at the onset of TTP, but the level of von Willebrand factor (vWF) antigen was not increased. The outcome in TTP patients was correlated with plasma t-PA and TM levels but not with TAT or PIC. These results suggest that vascular endothelial cell markers, such as TM and t-PA, are released from injured or stimulated endothelial cells, reflecting the degree of vascular endothelial damage, and that the main factor in the pathogenesis of TTP is vascular endothelial cell injury.

Adolescent↗

PubMed1993

Elevated plasma levels of vascular endothelial cell markers in patients with hypercholesterolemia.

Hypercholesterolemia is associated with an increased incidence of vascular complications. To assess the actual degree of activation of coagulation systems and vascular disorders in hypercholesterolemia, plasma levels of vascular endothelial cell markers, such as thrombomodulin (TM), tissue-type plasminogen activator, plasminogen activator inhibitor-I (PAI-I), and von Willebrand factor, were measured in 51 patients with hypercholesterolemia. We also investigated the effects of Pravastatin, an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase, on plasma lipid, lipoprotein a, and hemostatic markers. The mean plasma levels of thrombin-antithrombin III complex (TAT), fibrinopeptide A (FPA), TM, and PAI-I were significantly elevated in hypercholesterolemia. Of the hemostatic markers, only TM was significantly increased in patients with ischemic heart diseases (IHD). The mean concentration of total cholesterol and levels of TAT, FPA, PAI-I, and TM were significantly reduced after the Pravastatin treatment. The PIC/TAT ratio was significantly increased in non-IHD patients after treatment, this was not the case in IHD patients. These findings suggested the presence of a thrombogenic state and vascular endothelial cell disorders in hypercholesterolemia; such a state might well be related to hypofibrinolysis.

Adult↗

PubMed1993

Increased plasma level of interleukin-6 in disseminated intravascular coagulation.

Plasma interleukin-6 (IL-6) was higher in patients with disseminated intravascular coagulation (DIC) than in those without DIC. Levels of IL-1 beta and TNF alpha were also significantly higher in patients with DIC. Plasma IL-6 was highest in patients with underlying sepsis and was also high in those with advanced solid cancer. Levels were high in some patients with acute promyelocytic leukaemia and were significantly higher in patients with organ failure than in those without this complication. Plasma IL-6 was higher in DIC patients showing a poor response to therapy than in those with a good response. Incubation with IL-6 caused significant increases in tissue factor activity in mononuclear cells and release of plasminogen activator-1 antigen from human umbilical vein endothelial cells. As increases in IL-6 might give rise to hypercoagulable and hypofibrinolytic states, this may be a cause of DIC and be related to prognosis and organ failure.

Disseminated Intravascular Coagulation↗

PubMed1993

Stimulation of tissue type plasminogen activator by leukaemic cell homogenates.

In patients with disseminated intravascular coagulation (DIC), hyperfibrinolysis was observed in patients with leukaemia, but hypofibrinolysis was seen in those with sepsis. Although the plasma tissue plasminogen activator (t-PA) level was higher in patients with DIC than in those without DIC, there was no significant difference in t-PA level between the patients with leukaemia and sepsis. Hyperfibrinolysis might not be caused by t-PA derived from leukaemic cells, although the PA antigen level in leukaemic cell homogenates was significantly higher in patients with DIC than in those without DIC. The activation of t-PA by leukaemic cell homogenates in the absence of bromocyan fibrinogen fragments suggested that leukaemic cell homogenates had t-PA stimulator activity. The t-PA stimulator activity was high in both acute myeloblastic leukaemia (AML) and acute lymphoblastic leukaemia (ALL), especially in DIC, but this activity was not detected in chronic myelocytic leukaemia (CML) or normal cells. Since fibrinogen and soluble fibrin monomer complex levels in leukaemic cells were also high in patients with DIC, fibrinogen degradation products might be the major t-PA stimulator in leukaemic cells. This might be one of the causes of hyperfibrinolysis in leukaemia.

Biomarkers, Tumor↗

PubMed1992

Plasma thrombomodulin as a marker of vascular disorders in thrombotic thrombocytopenic purpura and disseminated intravascular coagulation.

Plasma thrombomodulin (TM) levels were significantly elevated at disease onset in patients with thrombotic thrombocytopenic purpura (TTP) and disseminated intravascular coagulation (DIC), but was not in those with essential thrombocythemia and idiopathic thrombocytopenic purpura. However, in patients with TTP and DIC, TM levels decreased significantly after they achieved complete remission. In both TTP and DIC patients, plasma TM levels at onset in those with poor prognosis were higher than that in those with good prognosis. Among DIC patients, the plasma TM level was higher in those with organ failure than in those without, but there were no differences among patients with various underlying diseases associated with DIC. It is speculated that the plasma TM level reflects damage to vascular endothelial cells or organ failure and that it is useful in assessing prognosis for patients with DIC and TTP.

Biomarkers↗

PubMed1992

Plasma cytokine levels in thrombotic thrombocytopenic purpura.

Plasma cytokine levels were examined in 13 patients with thrombotic thrombocytopenic purpura (TTP). Auto-antibodies, platelet-associated immunoglobulin G, and platelet aggregating factor were detected in many of these patients and high-molecular-weight bands of von Willebrand factor multimers were reduced in 9 of 10 patients examined. Complete remission (CR) was attained in 7 of the 13 patients, but 6 died. Tumor necrosis factor (TNF), Interleukin (IL)-1 beta, IL-6, and soluble IL-2 receptor showed marked increases at onset and decreased at CR. The prognosis tended to be poor in patients with increased IL-6 and soluble IL-2 receptor levels. These findings suggest that immunological mechanisms, such as the activation of macrophage, are involved in the pathogenesis of TTP and are reflected in the plasma cytokine levels.

Adolescent↗

PubMed1992

[Idiopathic thrombocytopenic purpura associated with pregnancy].

We examined 14 patients (18 cases) with idiopathic thrombocytopenic purpura (ITP) during pregnancy at our department. ITP, which had improved, recurred during pregnancy in 4 cases while it developed for the first time during pregnancy in 10 cases. In the other 4 cases, pregnancy occurred in the course of ITP. Although a normal infant was born in 14 cases, 3 stillbirth and a premature infant was observed in 4 cases. Six deliveries had some toxemia of pregnancy. A transient decrease in neonatal platelets was observed in 4 of 14 cases and mother's platelets count was less than 40 X 10(3)/microliters in the 4 cases. Although antinuclear antibody, Coomb's test and antiphospholipid antibody were positive in some cases, these were not markedly related to clinical course or neonatal platelets count. Eleven cases were treated with glucocorticoids, high dose gamma globulin or platelets transfusion, but 11 cases were not treated. Since ITP is frequently observed during pregnancy and may be some risk factor for pregnancy, treatment of ITP is important during pregnancy.

Adult↗