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Biomedical subjects

K Hata

Publications and source records attributed to K Hata.

At least 307 records · Page 17Linked to original sources
PubMed1991

Single-beat estimation of the slope of the end-systolic pressure-volume relation in the human left ventricle.

This study assessed a new method of estimating the slope (Ees) of the end-systolic pressure-volume relation (ESPVR) from a single beat of the human heart. Left ventricular pressure was recorded with a high-fidelity micromanometer in patients with heart disease during left ventriculography. Peak isovolumic pressure at the end-disastolic volume was estimated by a curve-fitting technique from an isovolumic left ventricular pressure curve. The ESPVR line was drawn from the estimated peak isovolumic pressure-volume point tangential to the left upper corner of the pressure-volume loop. The slope of this estimated ESPVR line from single-beat analysis was compared with the slope of the ESPVR line obtained from three pressure-volume loops in 16 patients given angiotensin II or nitroglycerin infusion. The estimated Ees was 5.0 +/- 2.2 mm Hg/ml/m2, and the conventional Ees was 4.9 +/- 2.7 mm Hg/ml/m2. The estimated Ees showed a positive correlation with the conventional Ees (r = 0.91, p less than 0.001, SEE = 1.2 mm Hg/ml/m2). In the other 13 patients, after dobutamine infusion (5 micrograms/kg/min i.v.) the estimated Ees increased significantly from 5.6 +/- 1.4 to 7.4 +/- 2.0 mm Hg/ml/m2 (p less than 0.01). Thus, the estimated Ees approximated the conventional Ees and was sensitive to a positive inotropic intervention. We conclude that this single-beat analysis method facilitates assessment of the beat-by-beat ESPVR of the human heart.

Angiotensin II↗
PubMed1991

Spot determinations of urinary cortisol for the screening of Cushing's syndrome.

The usefulness of spot determination of urinary cortisol in the screening of Cushing's syndrome was evaluated by measuring the cortisol concentration in randomly sampled urine in 68 normal subjects and in 9 patients with Cushing's syndrome. The urinary cortisol concentration in the morning was significantly higher in patients with Cushing's syndrome but some overlap existed between normal subjects and patients with Cushing's syndrome. In contrast, there was a clear discrimination between two groups when urinary cortisol was measured in the late evening: urinary cortisol was lower than 75 micrograms per gram creatinine (microgram/gCr) in normal subjects but higher than 150 micrograms/gCr in patients with Cushing's syndrome. When 1 mg dexamethasone was administered at 2300 h in the evening, spot urinary cortisol the next morning was less than 80 micrograms/gCr in normal subjects while it was above 100 micrograms/gCr in patients with Cushing's syndrome. Dexamethasone-induced suppression of urinary cortisol in normal subjects lasted until late in the afternoon, which allows sampling of urine at any time in the morning and possibly in the afternoon. These results suggest the usefulness of spot determination of urinary cortisol in the screening of Cushings' syndrome.

Adolescent↗
PubMed1991

Calcium kinetics and energetics in myocardium. Simulation study.

We carried out a simulation study to obtain insight into the relation between calcium (Ca2+) transients and energy for handling Ca2+ in excitation-contraction (EC) coupling. The simulation incorporated basic Ca2+ kinetics among total released Ca2+ from sarcoplasmic reticulum (SR), myoplasmic free Ca2+ ion concentration, and troponin (Tn)-Ca complex concentration ([TnCa]). The total Ca2+ released from the SR was arbitrarily set as an impulse and three rate constants were used for Ca2+ binding to Tn, Ca2+ dissociation from Tn, and Ca2+ uptake by SR. The results showed that the peak Ca2+ transient varies widely as a reciprocal of the Ca2+ sensitivity of the contractile machinery, despite constant total released Ca2+ and hence, a constant energy for Ca2+ handling. This result suggests a disproportate relationship between the magnitude of Ca2+ transients and the energy for Ca2+ handling when the Ca2+ sensitivity of contractile machinery changes.

Calcium↗
PubMed1991

Equivalent heart rate during ventricular fibrillation in the dog heart: mechanoenergetic analysis.

We propose equivalent heart rate (eHR) as an estimate of the frequency of contractions of individual myocytes in a fibrillating ventricle by analyzing mechanics and energetics of the ventricle. Using the isolated, cross-circulated dog heart preparation, we determined eHR in two different ways. First, we obtained eHR (eHR1) from myocardial O2 consumption (Vo2)-equivalent pressure-volume area (ePVA) data points during ventricular fibrillation (VF) by utilizing the Vo2-pressure-volume area (PVA) relation in the beating state. PVA is the area surrounded by the end-systolic and end-diastolic pressure-volume relations and the systolic pressure-volume trajectory in the pressure-volume diagram. PVA has been shown to represent the total mechanical energy generated by each contraction. We have recently proposed ePVA as a measure of the total mechanical energy generated by single contractions of all individual asynchronously contracting myocytes in a fibrillating ventricle. ePVA is the area surrounded by the horizontal line at the VF pressure and the end-systolic and end-diastolic pressure-volume relations in the beating state. Second, we measured Vo2 in beating state at various heart rates and Vo2 during VF under a mechanically unloaded condition. By comparing these fibrillating and beating Vo2 values, we determined eHR (eHR2) for the fibrillating state. eHR1 was 216 +/- 27 beats/min and eHR2 was 223 +/- 26 beats/min. These two values were not significantly different. We conclude that the average frequency of contractions of individual myocytes in a fibrillating ventricle is equivalent approximately to 220 beats/min in terms of ventricular energetics.

Animals↗
PubMed1991

Natural killer activity of human liver-derived lymphocytes in various liver diseases.

Liver-derived lymphocytes were isolated from 40 human livers with end-stage liver disease that were removed at the time of orthotopic liver transplantation. In addition, 10 resection specimens or whole livers removed from patients with liver cancer and seven normal livers (unused donor organs) were studied as controls. Liver-derived lymphocytes were isolated from enzymatically digested tissue by gradient centrifugation and adherence to plastic. Their phenotypical characteristics were studied by two-color flow cytometry, and effector cell function was determined in 4-hr 51Cr-release assays against a natural killer-sensitive target, K562 (natural killer activity), natural killer-resistant Daudi line (lymphokine-activated killer activity) and by P815 line with or without phytohemagglutinin to assess lectin-dependent cellular cytotoxicity. Liver-derived lymphocytes isolated from normal liver contained equal proportions of T and natural killer lymphocytes (mean natural killer/T ratio = 0.7). CD3-CD56+CD16- natural killer cells were the main natural killer subset present in liver-derived lymphocytes, in contrast to the predominant natural killer phenotype in the circulation (CD56+CD16+). Control liver-derived lymphocytes had levels of cytotoxicity significantly greater than those of the normal peripheral-blood lymphocytes against all three targets. In contrast, liver-derived lymphocytes isolated from organs with advanced liver disease differed markedly in the natural killer/T cell ratio and levels of liver-derived lymphocyte cytotoxicity. Liver-derived lymphocytes obtained from hepatocellular carcinoma or rejecting allografts treated by immunosuppressive therapy had virtually no cytotoxicity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[Clinical significance of antibodies against calmodulin in patients with various liver diseases].

The sera from patients with various liver diseases were investigated for the antibody against calmodulin (CaM) extracted from bovine brain by the enzyme linked immunosorbent assay. The specificity and purity of CaM were confirmed by the Western blot technique using anti-CaM antibody (anti-CaM) positive sera. IgA class antibody was frequently detected in patients with hepatocellular carcinoma (HCC), autoimmune hepatitis (AIH) and chronic active hepatitis (CAH). On the other hand, IgG class antibody was very often present in patients liver cirrhosis, AIH and acute viral hepatitis (AVH). Sixty seven percent of patients with AVH in the acute phase were positive for IgM class anti-CaM and 33% of patients with AVH in the convalescent phase positive respectively. In AVH, the titer of anti-CaM reached its peak on 26.3 days after the onset. The titer of anti-CaM in fulminant hepatitis was higher than that in AVH. Seventy percent of type A hepatitis patients were positive for IgM class anti-CaM, 33% of type B and 33% of type non-A non-B. These results suggest that the frequency and titer of anti-CaM may depend upon the type of hepatitis and the degree of liver cell injury.

Autoantibodies↗
PubMed1990

[Doppler ultrasonic assessment with hemodynamics of gynecologic tumor].

Color and pulsed Doppler ultrasound examinations were done on 11 normal volunteers (NU) and 286 patients that consisted of cervical carcinoma (CC), leiomyoma and/or adenomyosis (M), endometrial carcinoma (EC), trophoblastic disease (TD), benign ovarian tumor (BO), Krukenberg tumor (KT) and ovarian carcinoma (OC). The vascularity was based on the resistance index (RI) and maximum blood flow velocity (Vmax). In uterine disease, there was significant difference (p less than 0.01) among each group, except but one correspondence between NU and CC with RI, and there was significant difference (p less than 0.001) between NU and M, CC and M with Vmax. In ovarian disease, there was significant difference among each group with RI, and there was no significant difference among each group with Vmax. Therefore, Doppler ultrasound is a useful diagnostic tool for assessing gynecologic tumor vascularity.

Blood Flow Velocity↗
PubMed1990

Evaluation of tetrazolium-based semiautomatic colorimetric assay for measurement of human antitumor cytotoxicity.

A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)-based colorimetric assay was developed and compared with 51Cr release from different adherent tumor cell targets (human squamous cell carcinoma lines of the head and neck established in our laboratory, melanoma, and colorectal carcinoma) using 5-7-day human lymphokine-activated killer cells and monocyte-depleted peripheral blood lymphocytes as effectors. With adherent tumor cell targets, MTT colorimetry was more sensitive than the 51Cr release assay in measuring the antitumor activity of effectors: median, 4385 (range, 988-8144) versus median, 1061 (range, 582-7294) lytic units (the number of effector cells required to lyse 20% of 5 x 10(3) targets)/10(7) effectors (P less than 0.01). Background effects (without effector cells) were comparable in 4-h assays (9% versus 10%) between MTT colorimetry and 51Cr release. In 24-h assays, MTT colorimetry showed higher antitumor activity (70-100% versus 40-60% lysis at 1:1 effector:target cell ratio) but lower background effects (6% versus 38%) than 51Cr release assay. Thus, MTT colorimetry was more sensitive, did not use radiolabeled targets, required fewer effector cells, and was easier, less expensive, and better adaptable to serial monitoring of effector cell function in cancer patients. This colorimetric assay is especially well suited to adherent tumor cell targets. The use of adherent tumor cell monolayers, as opposed to trypsinized single cell suspensions, provides an opportunity to measure interactions of effector cells with enzymatically unaltered solid tumor targets. Because of the greater sensitivity of the colorimetric assay, the transformation of MTT data into lytic units, as commonly used for 51Cr release assays, required an adjustment to avoid the extrapolation based on the exponential fit equation.

Carcinoma, Squamous Cell↗
PubMed1990

Isolation, phenotyping, and functional analysis of lymphocytes from human liver.

The isolation of mononuclear cells from human liver tissues was achieved by a simple method consisting of enzymatic and mechanical dissociation, density gradient centrifugation, and adherence to plastic. The method was optimized to obtain a nearly complete recovery of different lymphoid subpopulations. The mononuclear cells recovered from "normal" liver tissues consisted of 33 +/- 9% (mean +/- SD) small lymphocytes, 44 +/- 6% large granular lymphocytes, 9 +/- 2% monocytes/macrophages, 9 +/- 3% granulocytes, and 5 +/- 2% other cells as determined by microscopic analysis of May-Grünwald-Giemsa-stained cytocentrifuge smears. Phenotypic analysis of the liver-infiltrating lymphocytes (LIL) by two-color flow cytometry showed that CD3-CD56+ NK cells represented 43 +/- 6% (mean +/- SD), CD3+CD56- T cells, 30 +/- 9%, and CD19+ B cells 3 +/- 1%. The predominant phenotype of the liver-infiltrating NK cells was CD3-CD56+CD16- in contrast to that of circulating NK cells, which are largely CD3-CD56+CD16+. The alpha/beta TCR+ T cells were 42 +/- 14% and gamma/delta T cells were infrequent (4 +/- 4%). The proportions of the three major lymphoid populations (T, NK, and B cells) recovered from liver tissues of 10 patients with different liver diseases were altered. Tissue sections from the same specimens were stained by the immunoperoxidase method to compare the in situ cellular composition with that determined by flow cytometry. LIL recovered from normal (control) and virally infected (non-A, non-B hepatitis) liver tissues had high NK activity (up to 1,000 LU/10(7) cells) as measured against K-562 targets in 4-hr 51Cr-release assays. NK activity was significantly lower (P less than 0.05) in LIL recovered from other liver diseases. LIL had spontaneous cytotoxicity against NK-resistant Daudi targets which was significantly higher (P less than 0.05) in control and virally infected than in other liver tissues. Our results indicated that human LIL recovered from normal and diseased liver tissues contained a high proportion of functionally active NK cells and that NK and lymphokine-activated killer activities but not the percentages of CD56+ cells were decreased in end-stage primary biliary cirrhosis and primary sclerosing cholangitis. In contrast, the proportions of NK cells and NK activity remain high in non-A, non-B hepatitis.

Aged↗
PubMed1990

Parametrial invasion of uterine cervical cancer assessed by transrectal ultrasonography: preliminary report.

Transrectal ultrasonographic examinations were performed on 30 patients with uterine cervical cancer to assess parametrial invasion. The findings were compared with data obtained by manual rectal examination. Forty-six parametria in 23 patients were histologically examined following surgery. Sensitivity, specificity, positive predictive value, negative predictive value, and predictive accuracy of transrectal ultrasonography and rectal examination were 1.0 and 0.25 (P less than 0.05), 0.9 and 0.93, 0.5 and 0.25, 1.0 and 0.93, and 0.91 and 0.87, respectively. Therefore, transrectal ultrasonography may prove to be a useful diagnostic tool to determine the preoperative staging of uterine cervical cancer.

Diagnostic Errors↗
PubMed1990

Squamous cell carcinoma of the esophagus with cartilaginous metaplasia at metastatic lesions.

Subdermal metastatic nodules in a 62-year old male patient with esophageal carcinoma contained both carcinomatous and chondroid areas. The carcinomatous areas showed the histology of poorly differentiated squamous cell carcinoma, and light microscopically an apparent transition could be traced from carcinomatous cells to chondroid cells. In the chondroid cells, the characteristics of chondrocytes were demonstrated by light microscopic, electron microscopic, histochemical and immunohistochemical studies, although nuclear atypism was evident, suggesting their malignancy. Furthermore, immunohistochemical studies showed that some chondroid cells contained both keratin proteins and squamous cell carcinoma antigen, which were also found in the carcinomatous cells. These findings together with the light microscopic observations suggest that chondroid cells are derived from squamous cell carcinoma cells.

Carcinoma, Squamous Cell↗
PubMed1990

Change in ovarian arterial compliance during the human menstrual cycle assessed by Doppler ultrasound.

Ovarian arterial velocimetry, using real-time two-dimensional and pulsed Doppler ultrasound, was performed on 36 occasions in nine healthy women with regular menstrual cycles. The change in ovarian arterial compliance was based on the calculation of pulsatility index (PI). In the active ovary carrying a dominant follicle or corpus luteum, the PI in the early follicular phase (mean 6.97, SD 2.01) was significantly higher than that in the late follicular phase (mean 2.36, SD 0.31) (P less than 0.001), and the PI in the early luteal phase (mean 0.68, SD 0.09) was significantly lower than that in the late follicular phase (P less than 0.001). The PI in the late luteal phase (mean 0.93, SD 0.16) was significantly higher than that in the early luteal phase (P less than 0.01). In the inactive ovary, no cyclical changes were seen in the values of PI. There was a significant difference between the values of PI in the active ovary and the inactive ovary in the late follicular, the early and the late luteal phases [2.36 (SD 0.31)] vs [6.29 (SD 1.02)], [0.68 (SD 0.09)] vs [6.18 (SD 1.33)], [0.93 (SD 0.16) vs [6.57 (SD 1.72)] (P less than 0.001), respectively. Use of non-invasive Doppler ultrasound to study physiology of ovarian haemodynamics during the menstrual cycle is of great clinical relevance and paves the way for further investigations on sterility.

Adult↗
PubMed1990

Ultrasonographic measurement of fetal lung.

Fetal lung measurements were obtained by ultrasonographic examination on 103 normal pregnancies between 18 and 41 weeks' gestation. A linear relationship between right, left and total lung circumference and gestational age was observed. The chest and heart circumference correlated well with gestational age (p less than 0.001). The ratio of left lung circumference to right lung circumference remained virtually constant throughout gestation. However, the ratios of total lung circumference to chest circumference and heart circumference to chest circumference increased significantly (p less than 0.001) with gestational age.

Embryonic and Fetal Development↗
PubMed1990

Sonographic findings of uterine leiomyosarcoma.

We describe herein various sonographic features of uterine leiomyosarcoma. Transabdominal scanning (TAS) revealed an image indistinguishable from benign leiomyoma, with evidence of degeneration. Transvaginal scanning (TVS) clearly showed the thinness of the myometrium, and the possibility of deep myometrial invasion was suspected at intraoperative open direct ultrasonography (ODU). A very high peak systolic velocity and a slightly increased diastolic component at the periphery of the tumor were evident with pulsed Doppler ultrasound. Thus, TAS, TVS, ODU and Doppler ultrasound will yield useful information for the physician attempting to evaluate the extent and vascularity of uterine leiomyosarcoma.

Female↗
PubMed1990

Efficiency of transvaginal scanning in obstetric and gynecologic fields.

Transvaginal ultrasonography was done on 26 pregnant women ranging from 5 to 27 weeks of gestation and 12 patients with gynecologic diseases. In early gestation, significant correlations were found among gestational age, crown-rump length, diameter of yolk sac and fetal heart rate. The maximal length of the gestational sac did not correlate with any other parameter. Transvaginal image quality was better in 76.2% in obstetric field and in 66.7% in gynecologic field, as compared to findings with conventional abdominal ultrasonography, respectively. Fine structures and individual organs were better evidenced transvaginally. Therefore, transvaginal ultrasound affords pertinent information complementary to that obtained with the transabdominal technique.

Female↗