Biomedical subjects

T Iwasaka

Publications and source records attributed to T Iwasaka.

At least 253 records · Page 14Linked to original sources

PubMed1990

Factors associated with late onset of advanced atrioventricular block in acute Q wave inferior infarction.

To elucidate the clinical characteristics associated with advanced atrioventricular (AV) block that appears relatively late (more than 24 hours) after the onset of myocardial infarction (MI), 101 patients with acute Q wave inferior MI were studied. Fourteen patients had late-onset advanced AV block, and 87 patients were free of AV block. The hospital mortality rate was 11%. Multivariate analysis was performed to determine the important variables associated with the occurrence of late advanced AV block and hospital mortality rates based on 12 clinical variables. Colloid osmotic pressure, right atrial pressure, serum potassium level, and number of segments with advanced asynergy were the significant factors associated with the occurrence of late advanced AV block, whereas advanced asynergic segments and alveolar arterial oxygen difference were important in the consideration of hospital mortality rates. Therefore not only the extent of myocardial ischemia but also the increases in the extracellular potassium level and interstitial fluid are some of the factors that are associated with the occurrence of late advanced AV block in acute inferior MI. Late advanced AV block, in itself, has no significant influence on hospital mortality rates.

Aged↗

PubMed1990

Effect of propranolol on diastolic time during exercise.

To evaluate the effect of propranolol on diastolic time (DT) during uninterrupted upright exercise, 11 men with normal coronary arteries receiving oral propranolol and 10 men with coronary artery disease (CAD) were studied by ear densitography. The DT-heart rate (HR) regression equation during exercise obtained from persons without CAD receiving propranolol was DT = e(6.923-0.014 X HR), which was not statistically different compared to that of normal volunteers with no medication. All 10 men with CAD had ischemic electrocardiographic responses at peak exercise with no medication but had no signs of ischemia during exercise after receiving oral propranolol therapy. Although propranolol caused no significant difference in the DT-HR relation in patients with CAD at 1-min exercise, a significant difference in the DT-HR relation was observed after propranolol therapy at peak exercise. In addition to negative chronotropic action (leftward shift along the DT-HR curve), prevention of disproportionate DT shortening at peak exercise (upward shift of the DT-HR curve) with propranolol through its beneficial action on myocardial ischemia tends to increase myocardial perfusion in patients who, when off propranolol, had ischemic response to exercise.

Adult↗

PubMed1990

Relation between thyroid and cardiac functions and the geriatric rating scale.

To assess the effects of thyroid hormone and cardiac function on senile dementia, relations between serum thyroid hormone concentrations, hemodynamic parameters and dementia rating scale scores were studied in 83 subjects aged 70 and over. Age and serum-free T3 concentrations had a significantly negative correlation in all subjects and in subjects without dementia, but not when analysed only in dementia subjects. Regarding the genesis of dementia, serum free T3 concentrations and cardiac index were both significantly lower in cerebrovascular dementia than in those without dementia. Moreover, subjects with cerebrovascular dementia showed significantly lower serum free T3 concentrations and cardiac index than those with senile dementia of Alzheimer's type in all age groups. These findings suggest that cognitive function is closely related to serum free T3 and cardiac function in subjects with cerebrovascular dementia and that serum free T3 concentrations may be a good indicator, reflecting health and cognitive status.

Aged↗

PubMed1990

Factors associated with pericardial effusion in acute Q wave myocardial infarction.

To elucidate the clinical characteristics associated with pericardial effusion in the early phase of myocardial infarction, 330 patients with acute Q wave infarction were studied. According to echocardiography, 83 patients had pericardial effusion on the third day of hospitalization, and careful auscultation revealed that a pericardial rub was absent in 45 patients and was present in 38 patients. Based on seven clinical variables, multivariate analysis was performed to determine the important variables related to the occurrence of pericardial effusion with and without pericardial rub. Pulmonary capillary wedge pressure and left ventricular segments with advanced asynergy were the significant factors related to the occurrence of pericardial effusion without a pericardial rub. The presence of ventricular aneurysmal motion, left ventricular segments with advanced asynergy, and alveolar arterial oxygen difference were related to pericardial effusion with a pericardial rub. Therefore, a hemodynamic factor was the major mechanism associated with the increase in extravascular myocardial fluid and the consequent occurrence of hydropericardia in the absence of a pericardial rub, whereas an increase in the microvascular permeability in the myocardium with excessive fluid exudating through the irritated epicardial surface was the mechanism related to pericardial effusion with a pericardial rub in the early phase of acute myocardial infarction.

Capillary Permeability↗

PubMed1990

Diastolic time during static and dynamic exercise in myocardial infarction.

To evaluate the difference in the response of DT in the early phase of static (sustained weight load) and dynamic (treadmill) exercise, the relation of DT and HR was studied by ear densitography in 11 patients with myocardial infarction. None of the patients had an ischemic electrocardiographic response during exercise. Despite an increase in HR and the pressure-HR product with both types of exercise, the pressure-HR product was significantly higher at three minutes of dynamic exercise, which was associated with a significant lengthening of left ventricular ejection time. Diastolic blood pressure rose significantly during static exercise, but it remained unchanged with dynamic exercise. Electromechanical systole and HR had a linear inverse relation at three minutes of exercise, and DT and HR had a nonlinear inverse relation (DT = e7.29-0.0156 x HR, and DT = e7.07-0.0142 x HR for static and dynamic exercises, respectively). A significant prolongation of QS2 with a consequent shortening of DT (p less than 0.05) was observed in dynamic exercise. In addition to a higher pressure-HR product, the disproportionate shortening of diastole in the early phase of dynamic exercise has a potential for initiating imbalance of myocardial oxygen supply and demand.

Blood Pressure↗

PubMed1990

[A case of an unusual mixed müllerian tumor in the lower uterine segment].

A unique case of a mixed müllerian tumor in a 33-year-old woman is presented. On gross examination of the hysterectomized specimen, well-circumscribed nodules, the largest measuring 3 cm in diameter, were found in the lower uterine segment. Microscopic examination revealed that the lesion was composed of a malignant glandular epithelium and a spindle cell stroma containing a smooth muscle. The atypical gland had deeply infiltrated into the normal myometrium and showed a squamous differentiation. This tumor should be differentiated from a benign mixed müllerian tumor, including an atypical polypoid adenomyoma, an adenofibroma, and an adenomyoma.

Adult↗

PubMed1990

[The possibility of viral etiology in cervical carcinogenesis].

Oncogenic potential of herpes simplex virus type 2 (HSV-2) and human papillomavirus (HPV) which are both associated with occurrence of cervical cancer and the mechanism of oncogenesis by these viruses were investigated by transformation experiments in vitro. The results were obtained as follows. 1) HSV-2 induced neoplastic transformation of normal diploid cells is a multistep process. Cervical cancer associated antigen AG-4 is encoded within the specific region of HSV-2 DNA which converts immortalized cells to tumorigenic lines. 2) Tumor cells express cellular oncogene at a final stage of neoplastic transformation induced by HSV-2 and "hit and run" theory is applicable to oncogenesis of this virus. 3) Complete carcinogenesis can be mediated by HPV-16 or HPV-18 DNA under collaboration with other cofactors such as HSV-2. 4) It is suggested that neoplastic transformation induced by HPV-18 DNA is based on "hit and run" oncogenesis. 5) HPV-16 or HPV-18 DNA can immortalize primary diploid cells and convert them to fully tumorigenic phenotype by repeating cell passage. 6) It has been experimentally proved that the difference in transforming potential exists between HPV 6/11 and HPV 16/18. 7) Amplification and overexpression of c-myc oncogene was detected in transformed cells obtained by HPV-16 transfection. While overexpression of c-myc was detected in transformed cells induced by HPV-18 DNA, but no amplification was observed. On the other hand, detection of HPV, DNA and amplification or overexpression of protooncogenes was performed in cervical intraepithelial neoplasias (CIN) and invasive cervical carcinomas. The results were summarized as follows. 1) HPV DNA was detected in approximately 70% of a population with CIN by in situ hybridization. CIN II showed the highest incidence of positive HPV DNA (91%), and the positive ratio decreased in CIN III (56%). 2) Immunohistochemical study of paraffin-embedded specimens with monoclonal antibodies to oncogene products revealed that only some of cervical invasive carcinomas expressed c-myc protein, ras p21 or EGFR. 3) HPV DNA was detected in 46% of invasive cervical carcinomas by Southern blot hybridization. The percentage of patients with positive results for HPV 16/18 was 29%. However, it increased up to 58% by use of polymerase chain reaction (PCR), suggesting that there are many cervical cancer tissues in which a number of cells lack viral DNA. 4) Northern blot hybridization analysis revealed overexpression of c-myc mRNA in 30% of cervical invasive carcinomas although amplification of c-myc oncogene was detected in only one of invasive carcinomas.(ABSTRACT TRUNCATED AT 400 WORDS)

Cell Transformation, Neoplastic↗

PubMed1990

[Clinical evaluation of the treatment of early cervical neoplasia by carbon dioxide laser conization].

One hundred twenty patients with cervical neoplasia were treated by conization, 78 with a carbon dioxide laser and 42 with a cold knife. Bleeding during the conization was 82.5 +/- 91.4 ml with the laser and 117.3 +/- 82.6 ml with the cold knife. The time required for the operation was 55.0 +/- 16.7 min and 37.7 +/- 10.2 min, respectively. With the aid of a local injection of epinephrine, peroperative bleeding was much less pronounced in the laser group (25.4 +/- 39.5 ml) and the time required for the operation was further shortened to 36.4 +/- 15.0 min. Six patients treated with the cold knife (14.3%) suffered postoperative hemorrhage requiring hemostasis, but only one in the laser series (1.3%). Forty-nine patients of 78 treated with the laser and 15 of 42 treated with the cold knife were subjected to conservative therapy. All of them were followed up by cytology, colposcopy and histology, and there was no failure or recurrence at either 8 weeks and 1 year after the operation. Unsatisfactory colposcopic findings developed in 9 patients (18.4%) in the laser group compared with 11 patients (73.3%) in the cold knife group. Specimens obtained after laser conization were satisfactory for use in histopathological evaluation. Conization with a carbon dioxide laser appears to be an acceptable procedure as a diagnostic method and conservative therapy for cervical neoplasia.

Adult↗

PubMed1990

[The role and clinical value of thallium-201 myocardial scintigraphy in ischemic heart disease].

To define the role and clinical value of thallium-201 myocardial scintigraphy in ischemic heart disease, 967 consecutive patients referred to our laboratory since 1985 were studied. The purpose of scintigraphy has changed from diagnosing myocardial ischemia to assessing myocardial viability with the progress of coronary angioplasty. At present, thallium-201 myocardial scintigraphy has become an indispensable noninvasive method for the management of patients with ischemic heart disease.

Adolescent↗

PubMed1990

Immunocytochemical detection of S-phase cells in normal and neoplastic cervical epithelium by anti-BrdU monoclonal antibody.

The use of a monoclonal antibody (MAb) to bromodeoxyuridine (BrdU) to identify S-phase cells was examined in 30 cervical biopsy specimens and 30 cervical smears from 18 patients with cervical neoplasia. Each patient received a local injection of 300 mg to 500 mg of BrdU into the cervix, at the time of endocervical laser conization, to label S-phase cells in neoplastic tissue. Labeled cells in normal and neoplastic tissues were detected in biopsy specimens or smears by indirect immunoperoxidase staining using the anti-BrdU MAb. The BrdU labeling index (BrdU LI, defined as the percentage of labeled cells in relation to the total number of cells counted) was calculated for all specimens. The level of BrdU-positive cells was 5.1% in normal cervical squamous epithelium, 12.3% in slight-to-moderate dysplasia and 21.2% in severe dysplasia to carcinoma in situ. In tissues without any dysplasia, BrdU-positive cells were mainly confined to the parabasal layer of the epithelium. In tissues showing slight-to-moderate dysplasia, BrdU-positive cells were mainly found in the lower half of the epithelium. BrdU-positive cells in severe dysplasia to carcinoma in situ were distributed throughout the full thickness of the epithelium. In addition, the few samples of squamous metaplasia and reserve cell hyperplasia encountered in this study exhibited a higher BrdU LI than did normal squamous epithelium. In cytologic specimens, BrdU-positive cells were found only in the cases of carcinoma in situ and in two cases containing normal cervical columnar epithelial cells. These results suggest that the immunocytochemical detection of BrdU by MAb staining may be useful for evaluating the proliferative activity in normal and neoplastic cervical epithelium.

Antibodies, Monoclonal↗

PubMed1990

Hemodynamic response to ibopamine in acute myocardial infarction.

To determine the effects of ibopamine on hemodynamic parameters, 9 patients with cardiac dilation after acute myocardial infarction were studied. Although there were no significant changes in mean blood pressure, heart rate and rate pressure product after administration of ibopamine, cardiac index and urine volume increased significantly. These data indicate that ibopamine exerts a positive inotropic effect on the myocardium and vasodilating effect on renal vasculature without increasing myocardial oxygen consumption. However, pulmonary capillary wedge pressure increased significantly at 30 min after ibopamine and decreased to the control value at 120 min. A significant increase in heart rate was observed in 3 patients which was followed by chest pain. In addition to increase in cardiac contractile force and decrease in subendocardial perfusion from elevated left ventricular end diastolic pressure, increase in heart rate would decrease diastole time, while increase in oxygen consumption results in aggravation of ischemia especially in patients with multivessel coronary disease. From these findings it is considered that ibopamine should be administered with care to patients with multivessel coronary disease.

Aged↗

PubMed1989

Oxygen delivery, oxygen consumption and hemoglobin-oxygen affinity in acute myocardial infarction.

The interrelations of oxygen delivery (DO2), oxygen consumption (VO2) and hemoglobin-oxygen affinity assessed by P50 were investigated in 43 patients with acute myocardial infarction. As DO2 declined due to low cardiac output, a significant decrease in VO2 (r = 0.75, p less than 0.001) and a significant increase in P50 (r = -0.74, p less than 0.001) were observed. In the DO2 range between 300 and 450 ml/min/m2, in which the DO2 of 32 survivors and 11 nonsurvivors overlapped, the P50 of nonsurvivors was significantly higher than that of survivors (31.5 +/- 1.6 vs 27.9 +/- 1.5 torr, p less than 0.001), but there were no significant differences in any other oxygen transport variable. As a result of differences in P50, VO2 in this range was significantly higher in nonsurvivors compared to survivors (169 +/- 17 vs 148 +/- 13 ml/min/m2, p less than 0.001). These data suggest that a normal or increased VO2 alone does not ensure survival in patients with acute myocardial infarction, and increased P50 leads to an increase in VO2. Nevertheless, the interpretation of an increased P50 in patients with acute myocardial infarction must be made with caution, even with adequate DO2 and VO2, because it may imply a precarious oxygen transport/requirement balance in peripheral tissue and, hence, a fatal outcome.

Aged↗

PubMed1989

Factors associated with persistent and transient fascicular blocks in anterior wall acute myocardial infarction.

To determine the factors associated with persistent and transient fascicular blocks, 144 patients with Q-wave anterior wall acute myocardial infarction (AMI) were studied. Thirty-three patients had new onset of fascicular block considered to be a consequence of AMI. Multivariate analysis using 16 clinical variables revealed that the number of asynergic segments, serum potassium level and pericardial rub were significant factors related to the occurrence of fascicular block. Among the 33 patients with fascicular block, 18 had persistent (group 1) and 15 had transient (group 2) fascicular blocks. When the 2 groups with fascicular block were compared, group 1 had significantly more asynergic segments than group 2 (4.7 +/- 1.2 vs 3.7 +/- 1.6, respectively), whereas pericardial rubs were observed significantly more in group 2 (67%) than in group 1 (28%). Therefore, the inflammatory process of AMI was 1 of the mechanisms related to the occurrence of a transient fascicular block and a more extensive myocardial necrosis was associated with a persistent fascicular block.

Aged↗

PubMed1989

Treatment of advanced cervical cancer by a combination of peplomycin, vincristine, mitomycin-C, and cisplatin.

Eighteen patients with advanced or recurrent carcinoma of the cervix were treated with a combination of peplomycin, vincristine, mitomycin-C, and cisplatin (POMP). Ten of the 16 evaluable patients (63%) responded, including 4 with a complete response. Median duration of the response was 7 months. Two of 6 with intrapelvic recurrent tumors responded to some extent following intraarterial infusion. The subcutaneous infusion of peplomycin was well accepted by the patients. Toxicity was tolerable. This regimen seemed to be one of the regimens which should be considered for the advanced or recurrent cervical cancer.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1989

Immunohistochemical demonstration of histiocytes in normal ectocervical epithelium and epithelial lesions of the uterine cervix.

The numbers of Langerhans cells and lysozyme-positive macrophages were assessed quantitatively in normal ectocervical epithelium, cervical intraepithelial neoplasia (CIN), microinvasive squamous cell carcinoma (MICA), clinical invasive squamous cell carcinoma (CICA), and koilocytotic atypia using the avidin-biotin-peroxidase complex (ABC) method. The distribution of Langerhans cells was different from that of lysozyme-positive macrophages in that the former were intermingled with the cervical lesion, while the latter were present mainly surrounding the cervical lesion and/or on the edge of the cervical lesion. The numbers of Langerhans cells and lysozyme-positive macrophages in CIN were significantly larger than those in normal ectocervical epithelium and significantly smaller than those in invasive squamous cell carcinoma (MICA + CICA). Langerhans cell number significantly increased as the grade of CIN advanced. In contrast, the number of lysozyme-positive macrophages did not differ significantly between progressive grades of CIN. As for koilocytotic atypia, the numbers of Langerhans cells and lysozyme-positive macrophages in koilocytotic atypia were significantly greater than those in normal ectocervical epithelium but did not differ significantly from those in CIN 1 and CIN 2. With respect to stromal lymphoid infiltration, invasive squamous cell carcinoma with moderate or dense stromal lymphoid infiltration showed significantly greater numbers of Langerhans cells and lysozyme-positive macrophages than that with no or scattered stromal lymphoid infiltration, but such a correlation was not found in CIN.

Carcinoma, Squamous Cell↗

PubMed1989

Effect of coenzyme Q10 on hemodynamic response to ocular timolol.

Coenzyme Q10 (CoQ10) is an essential component of the mitochondrial membrane and plays an important role in the maintenance of normal cardiac function. To evaluate the effects of ocular timolol on the cardiovascular system and determine the protective effect of CoQ10, 16 patients with glaucoma were studied using impedance cardiography. Following instillation of 1 mg timolol maleate in each eye, heart rate (HR) and stroke index (SI) decreased, and total peripheral resistance index (TPRI) increased significantly. Reexamination was performed after 6 weeks of 90 mg oral CoQ10. Despite decreases in HR, percent changes in HR were significantly less after CoQ10 at 120 min. Stroke index showed an initial increase which was not observed without CoQ10. These data suggest that CoQ10 delayed the appearance of inotropic blockade of timolol and hastened the disappearance of chronotropic blockade. Additional study of six normal volunteers with 6 weeks of oral CoQ10 showed a similar decrease of intraocular pressure after timolol instillation as compared to those without CoQ10. Thus, administration of oral CoQ10 in patients receiving ocular timolol may be useful in mitigating cardiovascular side effects without affecting intraocular pressure in the treatment of glaucoma.

Administration, Oral↗

PubMed1989

Diastolic time during low-level exercise in the late phase of hospitalization for acute myocardial infarction.

To evaluate DT during a low-level exercise test, the relation between DT and heart rate was studied by ear densitography in the late phase of hospitalization for acute MI. None of the patients had an ischemic electrocardiographic response. The patients were divided into two groups: group 1 was comprised of nine patients with a resting left ventricular end-diastolic volume of 140 ml or more, and group 2 was comprised of nine patients with a left ventricular end-diastolic volume less than 140 ml. The QS2 and heart rate had an linear inverse relation during exercise, and DT and heart rate had an nonlinear inverse relation (DT = e(7.27-0.0166 x heart rate) and DT = e(7.11-0.0142 x heart rate) for groups 1 and 2, respectively). Significant prolongation of the QS2 with consequent shortening of DT (p less than 0.05) was observed in group 1. Thus, in addition to a larger decrease in DT with a small change in heart rate, particularly during low-level exercise, patients with increased left ventricular end-diastolic volume have a potential for initiating subendocardial ischemia which results in further prolongation of systole and, hence, greater abbreviation of DT.

Blood Pressure↗

PubMed1989

Left ventricular regional function after acute anterior myocardial infarction in diabetic patients.

To elucidate the pathophysiological role of diabetes mellitus in determining the left ventricular regional function of the noninfarcted area, 55 patients with acute Q wave anterior myocardial infarction (MI) were studied. The regional ejection fraction of the noninfarcted area was obtained by radionuclide angiocardiography and was used to estimate the left ventricular regional function of the noninfarcted area. Multiple regression analysis was performed to determine the important variables contributing to the regional ejection fraction based on 10 clinical variables: age, sex, QRS score, diabetes mellitus, hypertension, smoking, postinfarction angina, body mass index, serum cholesterol, and coronary atherosclerosis. A high QRS score (P less than .001) and the association of diabetes mellitus (P less than .05) were the important factors contributing to regional left ventricular dysfunction. The regional ejection fraction and QRS score had an inverse linear relationship in the diabetic and nondiabetic groups, and the regional ejection fraction was significantly lower in diabetic patients at every QRS score (P less than .05). The association of hypertension, severity of coronary atherosclerosis, serum cholesterol level, age, and body mass index did not differ between diabetic and nondiabetic patients, which indicates that diabetes mellitus was not mediated through these atherogenic traits. Thus, diabetes mellitus is another discrete cause of regional left ventricular dysfunction of the noninfarcted area after acute MI.

Diabetes Mellitus, Type 2↗