PubMed Health⌕ Search

Biomedical subjects

M Nakatani

Publications and source records attributed to M Nakatani.

At least 73 records · Page 4Linked to original sources
PubMed1992

[Augmentation of left ventricular slow filling in hypertrophic cardiomyopathy].

To investigate the significance of augmentation of left ventricular slow filling, trans-mitral flow (TMF) was echocardiographically observed through pulsed Doppler method in 116 patients with hypertrophic cardiomyopathy (HCM), 74 with dilated cardiomyopathy (DCM), 27 with mitral regurgitation (MR), 86 with old myocardial infarction (OMI) and 80 normal controls (C). The slow filling-wave (SFW) in TMF was defined as the filling wave with obvious peak velocity during slow filling phase. The peak velocities (E, A, S) of the early filling, the atrial contraction and the slow filling waves were measured. The SFW was divided into two patterns according to the S and E ratio: large SFW (S/E greater than or equal to 1/2) and small SFW (S/E less than 1/2). 1) The small SFW was more frequently, but not significantly, observed patients with MR (37%) than in normal subjects (18%), patients with HCM (10%), DCM (4%) and OMI (7%). However large SFW was observed in 16 patients (14%) with HCM, but not in normal subjects and patients with other cardiac diseases excluding one patient with DCM. 2) In normal subjects and patients with DCM, OMI and MR, those with small SFW had larger E and smaller A/E than those without small SFW. However in patients with HCM, there was no difference in these indices (E and A/E) according to whether the patients were with or without SFW. 3) In HCM, patients with large SFW had significantly smaller E and significantly larger isovolumic relaxation time than those without SFW. Thus, appearance of the large slow filling wave, which might be caused by abnormal relaxation of the left ventricle, was frequently observed in patients with HCM.

Adult↗
PubMed1992

[The controversy on the treatment of aortic dissection].

It is obvious that there are many controversies regarding to the treatment of aortic dissection. In this report, we discuss following points such as 1) classification, 2) thrombosed type dissection, and 3) simultaneous graft replacement of ascending and aortic arch with the reconstruction of cervical branches. From the patho-morphological status, dissection will be classified into two types, localized and extended types. From the anatomical and surgical points of view, it will be also classified as 1) ascending-arch, 2) descending-thoracoabdominal, and 3) abdominal. With the combination of these two, dissection will be classified more clearly. The thrombosed type will be incorporated into localized type. We have experienced 76 cases of this dissection, and clinical features and outcome by medical treatment only are presented. The simultaneous reconstruction of ascending aorta and aortic arch for the dissection at ascending-arch type was undertaken in total of 35 patients. The surgical results as well as follow up data are presented and the benefit of this extended procedure is presented as well.

Aortic Dissection↗
PubMed1991

Axon orientation and axo-dendritic polarity of retinal ganglion cells during postnatal development in the rat.

The axon orientation and axo-dendritic polarities of ganglion cells were investigated in the retinae of developing and adult rats labeled with retrograde tracers. The cells were classified as either regular, if both parameters corresponded to those found among the majority of ganglion cells in the retina of adult rats, or irregular, if either axon orientation or axo-dendritic polarity, or both, failed to follow the norm of adult retinae. The number of regular cells declined from 118,000 to the adult value of 63,000 during the first 5 days following birth, while the number of irregular cells remained stable at 90,000-100,000 during this period and declined thereafter to 46,000. These data suggest that the geometry of neurites within the retina affect the selective elimination of ganglion cells during postnatal development in rats.

Animals↗
PubMed1991

[Bone metastases in breast cancer and its risk factor--follow up study by bone scintigraphy].

Breast cancer is considered to often involve bone metastasis. Early detection and treatment of bone metastasis are essential in improving the prognosis of this disease. In 47 patients with bone metastasis confirmed with bone scintigraphy, we examined the appearance time of bone metastasis; bone metastasis was frequently observed with the progress of stage, but no association with the appearance time was found. Age was not associated with the incidence of bone metastasis but was found to be closely related to its appearance time. That is to say, patients with breast cancer below 40 years of age showed relatively early bone metastasis. Bone scintigraphy is required every 6 months at least for 3 years after the operation. In patients over 40 years of age, on the other hand, bone scintigraphy is required only once a year but has to be continued for 5 years or more, because they often show relatively late bone metastasis.

Adult↗
PubMed1991

[Effects of verapamil on the left ventricular diastolic function and diastolic asynchrony in patients with hypertrophic cardiomyopathy].

The effects of verapamil on the diastolic function and regional asynchrony of the left ventricle were echocardiographically investigated in 37 patients with hypertrophic non-obstructive cardiomyopathy (HCM). Before and 20 min after the intravenous administration of verapamil (0.1 mg/kg), blood pressure (BP), heart rate (HR), transmitral pulsed Doppler indices (R, A, A/R), M-mode echo indices (Dd, Ds, %FS) and the echo-phonocardiographic index (isovolumic relaxation time; IRT) were measured. We also measured the rapid extension times of the posterior walls at the chordae and papillary muscle level [Tc(pw), Tp(pw)] as the indices of regional diastolic function, and their difference [Tp-c(pw)] was used as the index of diastolic asynchrony. Before verapamil administration, the HCM patients had significantly larger A, A/R, IRT and Tp-c(pw) and smaller R than did 20 healthy controls, but showed no significant differences in HR, BP, Dd, Ds and %FS. After verapamil injection, R increased and A, A/R, IRT, Tp-c(pw) decreased significantly without any changes in BP and HR. The increment of R (delta R) correlated significantly with the decrement of Tp-c(pw) (r = -0.66, p less than 0.001). According to the value of delta R/R, 37 patients with HCM were categorized in 2 groups (19 responders with delta R/R greater than or equal to 10% and 18 non-responders with delta R/R less than 10%). The responders had smaller R and larger A/R, IRT and Tp-c(pw) before verapamil administration than did the non-responders. Verapamil increased R, Dd, Ds and decreased A, A/R and Tp-c(pw) in the responders, but not in the non-responders. These results suggested that verapamil might improve left ventricular diastolic function in HCM patients through the improvement of left ventricular diastolic asynchrony.

Adult↗
PubMed1990

Ultraviolet imaging densitometry of unstained gels for two-dimensional electrophoresis.

A system suitable for ultraviolet imaging densitometry of two-dimensional electrophoretic gels that are unstained is described, together with its applications. A flying-spot densitometer linked with a personal computer was used for data acquisition, generation of mapping data, and image processing. Randomly distributed zones of proteins on two-dimensional gels were detected at 280 nm without being stained by two-dimensional scanning, and the densitometric value of each pixel (0.2 x 0.2 mm) was memorized by the computer, which generated a mapping pattern with density contours. The amount and densitometric value of cytochrome c had a linear relationship in the range of 2-200 micrograms. Zone locations of bovine liver proteins separated on two-dimensional gels were indicated on a map expressed in X-Y coordinates, and the pIs and molecular weights could be calculated from the map by use of pI and molecular weight markers on the same gel.

Animals↗
PubMed1990

Reappeared pancreatic cyst after surgical treatment of cystic lesions of the pancreas.

An extremely high incidence of reappearing cyst of the pancreas (24.1%; 7 out of 29 patients) was noted in the present survey. However, reappearance could have been avoided in the majority of cases with the use of thorough pre- and peri-operative assessments of the extent of cystic lesion of the pancreas. The recurrence rate after surgical treatment for pseudocysts (13.6%; 3 out of 22 patients) was similar compared with usual recurrence rate of approximately 10 percent. If the reappearing cyst is a retention cyst or a pseudocyst, a minimally aggressive procedure should initially be considered to aid its resolution. A part of this study was reported at the 51st meeting of the Japanese Society for Clinical Surgery on November 2, 1989 at Kobe, Japan.

Adolescent↗
PubMed1989

AMP deaminase as a cell-age marker in transient erythroblastopenia of childhood and its role in the adenylate economy of erythrocytes.

Erythrocytes from 11 patients with presumptive diagnoses of transient erythroblastopenia of childhood were evaluated retrospectively (six) or prospectively (five) for a possible relationship between erythrocyte adenosine 5'-monophosphate aminohydrolase, adenylic acid deaminase (AMP deaminase) activity and intracellular concentrations of adenine nucleotides. Older red blood cell (RBC) cohorts in these patients consistently exhibited significantly decreased activities of AMP deaminase (approximately 5% to 70% of normal control mean) in association with increased concentrations (up to threefold) of adenosine triphosphate (ATP) and total adenine nucleotides. We postulate that the latter is a direct consequence of the former, since diminishing AMP deaminase activity in aging cells should reduce the drain on the adenine nucleotide pool imposed by irreversible deamination of AMP to inosine 5'-monophosphate. Consistent reductions in AMP deaminase activity indicate that this enzyme should also serve as a reliable marker of mean RBC age useful in diagnostic confirmation of transient erythroblastopenia. The observed increases in ATP and total adenine nucleotides in older RBCs require a reevaluation of the traditional view that age-related losses of these compounds mediate the ultimate demise of senescent erythrocytes. Similar alterations in the balance of degradative and salvage pathways in RBC nucleotide metabolism may also underlie certain cases of so-called "high ATP syndrome."

AMP Deaminase↗
PubMed1989

[Blood flow dynamics of the portal venous system in liver cirrhosis using pulse Doppler method].

Blood flow dynamics of the portal venous system including portal vein, splenic and superior mesenteric arteries, in thirty seven cases with liver cirrhosis and 32 controls were studied by means of the pulse doppler method. Maximum blood flow velocity of the main portal vein in liver cirrhosis was 0.21 m/sec in mean, significantly lower than in controls. Blood flow volume of the portal vein in liver cirrhosis was 18.9 ml/min.kg, which was a significant increase compared with that of controls. The cases of liver cirrhosis showed an increased blood flow volume of the splenic and superior mesenteric arteries, showing an increased pre-load to the spleen. In 5 cases, liver volume measured by computed tomography was not changed despite of an increase of the main portal venous flow volume. Three of these 5 cases were of more advanced liver cirrhosis with over 40 percent of ICG value. They bend to have higher portal venous velocity than the other cases with less advanced liver cirrhosis. No correlation of the splenic arterial flow volume and the spleen volume was thought to indicate after-load to the spleen as a factor of splenic enlargement.

Blood Flow Velocity↗
PubMed1989

Inhibition of adenylate kinase by P1,P5-di(adenosine 5') pentaphosphate in assays of erythrocyte enzyme activities requiring adenine nucleotides.

P1,P5-di(adenosine 5')pentaphosphate (Ap5A) is an excellent inhibitor of human hemolysate adenylate kinase at concentrations near 2 microM and above. At ten times this concentration and in hemolysate enzyme assays under conditions described in this paper it appears not to alter reaction data in the case of hexokinase, phosphofructokinase, and phosphoglycerokinase. In the pyruvate kinase assay, very modest reductions in activity are noted, and kinetics with phosphoenolpyruvate, adenosine diphosphate (ADP), and uridine diphosphate (UDP) are unaltered.

Adenosine Diphosphate↗
PubMed1989

Ultrasonographic findings in gastric cancer: in vitro and in vivo studies.

Ultrasonography was performed in 45 cases of gastric cancer. Specimens from all 45 cases of gastric cancer were subjects to ultrasonographic study by the water immersion method for comparison with histology. In 32 of these 45 cases in vivo ultrasonographic evaluation was performed prospectively. The overall accuracy rates for the diagnosis of the depth of cancerous invasion were almost 80% in both in vitro and in vivo studies. In vivo ultrasonographic findings agreed well with those from the specimen studies. Ultrasonography was considered to be useful in the diagnosis of gastric malignancies.

Humans↗
PubMed1989

Macrophage-produced oxygen radical generating activities for polymorphonuclear leukocytes.

Guinea pig peritoneal macrophages were stimulated in vitro by bacterial lipopolysaccharide. After incubation, the supernatants of macrophage cultures were collected and tested for O2- production on guinea pig peritoneal polymorphonuclear leukocytes. The supernatants of macrophage cultures stimulated by lipopolysaccharide had significantly higher levels of O2- -generating activities in polymorphonuclear leukocytes, and these activities appeared in the macrophage cultures within 2 h after stimulation by lipopolysaccharide. However, the supernatants obtained from the nonstimulated cultures could not produce these activities. These activities disappeared with heating or trypsin and were not produced in macrophage cultures by incubation with cycloheximide.

Animals↗
PubMed1988

Pyruvate kinase Greensboro. A four-generation study of a high K0.5s (phosphoenolpyruvate) variant.

The proband with lifelong hemolytic anemia has a high K0.5s phosphoenolypyruvate (PEP) erythrocyte pyruvate kinase (PK) variant substantially but incompletely normalized by the allosteric modifier fructose-1,6-diphosphate (F-1,6-P2) with conversion of sigmoidal to hyperbolic kinetics. Heterozygotes in four generations express qualitatively identical but less severely abnormal kinetics and lack overt hemolysis. Kinetic abnormalities are closely mimicked by sulfhydryl modification of normal PK. Three distinct clinical and metabolic phenotypes characterize the proband and two sisters: variant PK and hemolytic anemia, variant PK without clinical manifestations or hemolysis, and complete normality. Their mother, whose red cell PK is entirely normal except for a questionably slightly low Vmax, is postulated to express the gene products of nonidentical alleles, one encoding a product with mildly less favorable catalytic characteristics. At low PEP concentrations, the proband and heterozygotes for the PK mutant express only a very small fraction of normal PK activity despite apparent inheritance of one normal allele in the latter. Evidence suggests that disproportionately lowered PK activity may be a property of a heterotetrameric PK. Illusory abnormalities in nucleotide specificity are artifacts of diminished substrate affinity characterizing the mutant PK.

Adenine Nucleotides↗
PubMed1987

Erythrocyte pyruvate kinase (PK): the variable significance of "nucleotide specificity" in the characterization of mutant variants.

The half-saturation constant (K0.5s) phosphoenolpyruvate (PEP) for red cell pyruvate kinase (PK) with co-factors UDP and GDP is less than one-half that with ADP with or without additions of the allosteric modifier, fructose-1, 6-dephosphate (F-1, 6-P2) to the assay. The Vmax is markedly greater with ADP than with UDP or GDP, but with (PEP) at 0.5 mM, activity with all co-factors is about equal and at lower concentrations greater with UDP and GDP. With high K0.5s (PEP) mutant enzymes, and at the usual test concentration (lmM) for PEP when nucleotide specificity is assessed, the abnormally low saturation of variant enzymes may result in higher activity with UDP and GDP than with ADP--the opposite of the "normal situation." The apparent aberration in nucleotide specificity may thus be illusory and secondary to the abnormal K0.5s (PEP) of the mutant. Example data are recorded. Variations in K0.5s (PEP) may also be introduced during enzyme preparation for assay, particularly when partial purification is employed.

Erythrocytes↗
PubMed1987

Modification of erythrocyte enzyme activities by persulfides and methanethiol: possible regulatory role.

Sulfhydryl modification of 22 human erythrocyte enzymes was achieved by exposing intact erythrocytes, hemolysates, and partially purified enzymes to persulfides (RSSH) generated nonenzymatically from cystine in the presence of pyridoxal phosphate and mercaptopyruvate, which donates its sulfur to suitable acceptors with the mediation of the carrier enzyme, mercaptopyruvate sulfurtransferase (EC 2.8.1.2). The inhibition pattern was qualitatively similar for persulfides and that previously reported by us for the methylthio-group donor, methyl methanethiosulfonate. Thirteen activities were inhibited, and 9 were minimally or not at all affected. Pyruvate kinase was similarly modified by all systems in terms of phosphoenolpyruvate kinetics, thermostability, and interaction with the negative effector ATP. Partial-to-complete reversal of inhibition was documented in a subset of activities inhibited by mercaptopyruvate upon 30-min incubation with 1 mM dithiothreitol. A possible physiologic role for methylthio groups and for persulfides is discussed.

Cysteine↗
PubMed1987

Effects of percutaneous transluminal coronary angioplasty on segmental left ventricular function in patients with acute myocardial infarction.

In order to investigate the usefulness of percutaneous transluminal coronary angioplasty (PTCA) on subsequent left ventricular (LV) function in patients with acute myocardial infarction (AMI), regional ejection fraction (REF) was calculated from the left ventriculogram and compared in the acute and chronic phases (4 weeks after infarction) in 19 successful cases of PTCA (group A). In addition, 15 successful cases of intracoronary thrombolysis (PTCR) (group R) and 14 unsuccessful cases (group U) were also analyzed in this study. From the results, the following points were elucidated. (1) REF of group A in the chronic phase showed a significant increase compared to that in the acute phase (10 +/- 18% vs 20 +/- 19%, p less than 0.01), and this was similar to that observed in group R (9 +/- 19% vs 21 +/- 16%, p less than 0.01). (2) All cases in group A showed a significant increase in REF (p less than 0.02), if recanalization occurred within 3 hours after the onset of AMI. Some cases in the 3-6 hour recanalization group showed a decrease in REF. (3) In group A, only patients with subtotal occlusion on the initial coronary angiogram showed a significant increase in REF 4 weeks later (p less than 0.01), whereas patients with total occlusion on the initial coronary angiogram showed no significant increase in REF. (4) In group A, only patients recanalized between 3 and 6 hours showed a severe degree of prolonged contrast staining immediately after successful recanalization following PTCA. Thus, chronic phase regional wall motion was markedly improved by PTCA in those cases with residual flow. In contrast, abrupt recanalization after PTCA might causally decrease regional wall motion due to hemorrhagic infarction, if it is performed in cases with total occlusion.

Angioplasty, Balloon↗