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Biomedical subjects

K Kodama

Publications and source records attributed to K Kodama.

At least 253 records · Page 14Linked to original sources

Auditory brainstem responses in infants and children with anoxic brain damage due to near-suffocation or near-drowning.

We studied auditory brainstem responses (ABRs) of sixteen infants and children with brain damage after anoxic accidents due to near-suffocation or near-drowning. The patients manifested cerebral palsy, mental retardation and/or epilepsy and showed poor responses in the behavioral audiometry. Auditory brainstem responses were abnormal in five of the patients in the near-drowning group (waves I, II and III only were present in three patients and the amplitudes of waves IV and V were low in two patients) but normal in most of the patients in the near-suffocation group. This difference in the ABRs between the two groups suggest that in infants and children anoxic brain damage due to near-drowning might involve not only the cerebral cortex and subcortical white matter but also the upper brainstem and midbrain.

Brain Injuries↗

Collateral channels that develop after an acute myocardial infarction prevent subsequent left ventricular dilation.

OBJECTIVES: We sought to evaluate the effect of collateral channels that develop late after a first anterior myocardial infarction on left ventricular dilation and function. BACKGROUND: Collateral channels in an infarct-related artery may develop long after occlusion of the artery. Well visualized collateral channels that appear immediately after a myocardial infarction reduce infarct size and preserve left ventricular function. However, the functional significance of collateral channels that develop late after myocardial infarction has not been evaluated in terms of left ventricular function. METHODS: We studied 21 patients with a first anterior myocardial infarction and an infarct-related artery that remained totally occluded after reperfusion therapy and did not reopen within 1 month of infarction. No collateral channels were observed during the acute period. Patients were classified into two groups according to the extend of collateral formation 1 month after infarction: group C, patients with well developed collateral channels (n = 11), and group NC, patients with absent or poorly developed collateral channels (n = 10). Infarct size was determined by peak creatine kinase activity and thallium-201 single-photon emission computed tomography. Global and regional left ventricular function and left ventricular volumes were assessed by left ventriculography. These measurements were identical in both groups 1 month after infarction. Left ventricular function was reevaluated after 2.12 +/- 0.79 years (mean +/- SD). RESULTS: There were no significant changes in global and regional left ventricular function between the two groups during the long-term follow-up period. However, the end-diastolic volume index of group NC increased from 71 +/- 14 to 85 +/- 19 ml/m2, whereas that of group C decreased from 64 +/- 18 to 59 +/- 12 ml/m2. This important change during the long-term follow-up period resulted in a significant difference (p = 0.0006) in the end-diastolic volume index between the groups 2 years after onset (p = 0.002), whereas 1 month after infarction the difference was not significant (p = 0.36). A similar pattern was observed for the end-systolic volume index (group C: 38 +/- 16 to 35 +/- 14 ml/m2; group NC: 45 +/- 12 to 58 +/- 18 ml/m2, p = 0.018). The power of the tests to detect the observed differences showing nonsignificant results ranged from 0.05 to 0.38, whereas the power of the tests indicating a significant difference in end-diastolic and end-systolic volume indexes was >0.88. CONCLUSIONS: Collateral channels that develop after a myocardial infarction do not reduce the infarct size or prevent left ventricular dilation within 1 month of infarction. In contrast, such collateral channels prevent subsequent ventricular dilation and the deterioration of left ventricular function over 2 years. However, our results may have been biased because of the small number of patients.

Aged↗

Ruptured inferior mesenteric artery aneurysm due to segmental mediolytic arteritis.

Segmental mediolytic arteritis is a rare non-inflammatory arteriopathy. Only eight cases have been reported so far. The authors report a case of a ruptured inferior mesenteric artery aneurysm due to segmental mediolytic arteritis in which preoperative angiography revealed lesions and successful surgical treatment was performed. A review of the clinical features of segmental mediolytic arteritis is also presented.

Aneurysm, Ruptured↗

Determinants of vertebral fracture prevalence among native Japanese women and women of Japanese descent living in Hawaii.

Age-adjusted prevalence of vertebral fracture has been reported to be higher among native Japanese women than among women of Japanese descent living in Hawaii. In this cross-sectional population-based study, we examined a variety of potential risk factors for associations with prevalent vertebral fractures and investigated whether these factors could explain the difference in vertebral fracture prevalence between native Japanese and Japanese-American women. Spine radiographs and data on spine bone mineral density (BMD) and other potential risk factors were collected among 802 Japanese women aged 50-88 years living in Hiroshima and 840 Japanese-American women aged 52-88 years living in Hawaii. In logistic regression analysis, BMD was a major predictor of prevalent vertebral fracture. In linear regression models, weight, age, and menstrual history (age at menopause or years between menarche and menopause) were significantly associated with BMD and thus might contribute to fracture risk indirectly through their effects on BMD. However, age and menstrual history provided additional and complementary information about fracture prevalence after adjusting for BMD. These variables together explained much of the difference in vertebral fracture prevalence between the two study populations. We conclude that the observed difference in age-adjusted prevalence of spine fracture between native Japanese and Japanese-American women was accounted for primarily by the differences in BMD, duration of estrogen exposure, and/or duration of estrogen deficiency. Thus, current BMD is a major but not the sole risk factor for vertebral fractures. Age-related and menopause-related mechanisms may also play an important role in spine fracture independent of BMD.

Absorptiometry, Photon↗

A selective type V phosphodiesterase inhibitor, E4021, protects the development of right ventricular overload and medial thickening of pulmonary arteries in a rat model of pulmonary hypertension.

We evaluated the effects of oral administration of 10, 30, and 100 mg/kg/day of E4021, a type V phosphodiesterase inhibitor, on development of monocrotaline-induced right ventricular overload and medial thickening of pulmonary arteries. Right ventricular systolic pressure, mass ratio of right ventricle to left ventricle, right ventricular wall thickness, right ventricular myocardial fiber diameter, medial thickness, and smooth muscle area in pulmonary arteries were significantly less in rats that received E4021 30 and 100 mg/kg/day than in the control with monocrotaline on day 28. Myofiber diameter, medial thickness, and smooth muscle area were significantly lower in rats treated with E4021 100 mg/kg/day than in those of E4021 30 mg/kg/day. E4021 100 mg/kg/day protected development of right ventricular overload and medial thickening of pulmonary arteries.

Animals↗

Prognostic significance of diabetes mellitus in patients with acute myocardial infarction after recanalization.

Although diabetic patients are at high risk for ischemic heart disease, the effect of diabetes mellitus on the prognosis of patients with acute myocardial infarction after recanalization therapy is controversial. In this study 255 patients with acute myocardial infarction admitted to CCU for coronary recanalization therapy were studied. In 95 diabetic patients, in-hospital mortality (26% for 4 weeks), complication of heart failure (35%) were significantly higher than in 160 non-diabetic patients (mortality 5%, and heart failure 11%), whereas incidence of post-infarction angina is not different between the two groups. Mortality in diabetic patients was not influenced by previous history of myocardial infarction and the number of diseased vessels. Multivariate analysis of risk factors showed that among non-cardiac risk factors, diabetes mellitus is a most important risk factor for short-term prognosis of patients with acute myocardial infarction.

Adult↗

Characterization of peripheral blood progenitor cells (PBPC) mobilized by filgrastim (rHuG-CSF) in normal volunteers: dose-effect relationship for filgrastim with the character of mobilized PBPC.

Filgrastim (rHuG-CSF)-mobilized peripheral blood progenitor cells (PBPC) in healthy Japanese volunteers were characterized in detail using two clonal cell culture systems and double-colour flow cytometry to detect multilineage colony-forming cells and subsets of CD34+ cells. The kinetics of PBPC during the administration of filgrastim was studied, and possible differences in the character of progenitor cells relative to given doses of filgrastim were investigated. Filgrastim was administered subcutaneously to normal volunteers for 7 d at doses of 100, 200 or 400 microgram/m2 (10 per cohort). Treatment with 100 or 200 microgram/m2 filgrastim was well tolerated; however, the 400 microgram/m2 dose level was not completed because of bone pain and myalgia. The treatment strikingly mobilized various types of progenitor cells, including highly proliferative megakaryocytic colony-forming cells. The number of progenitor cells peaked on days 5 and 6. The fold increase of circulating progenitor cells from the baseline value in the volunteers treated with 200 microgram/m2 filgrastim was more pronounced than in those treated with 100 microgram/m2. Treatment with 200 microgram/m2 also released the less mature progenitor cells (i.e. mixed colony-forming cells CD34+/33- cells, and CD34+/HLA-DR-cells) into circulation better than the 100 microgram/m2 dose. These results suggest that daily subcutaneous injection with 200 microgram/m/2 filgrastim for 5 d will effectively mobilize, both qualitatively and quantitatively, PBPC in healthy donors.

Adult↗

Phylogenetic position of yeastlike endosymbionts of anobiid beetles.

The Anobiid beetles Stegobium paniceum and Lasioderma serricorne possess the intracellular yeastlike symbionts Symbiotaphrina buchneri and Symbiotaphrina kochii, respectively, in the mycetome between the foregut and midgut. The nucleotide sequences of the small-subunit rRNA-encoding genes of the symbionts were determined for phylogenetic analysis. Five group I introns were found in the small-subunit rRNA-encoding genes of S. buchneri, but S. kochii lacked introns. The phylogenetic position of both symbionts was close to the class Discomycetes, which is a paraphyletic group. The two symbionts formed a monophyletic group distinct from the other major lineages. Both appear to have parted from other filamentous fungi during the early radiation of the euascomycetes and to have later become obligatory partners of the beetles.

Animals↗

Bcl-2 oncoprotein expression is increased especially in the portion of small cell carcinoma within the combined type of small cell lung cancer.

Immunohistochemical analysis of Bcl-2 oncoprotein, one of the oncogenes associated with the regulation of programmed cell death, was performed on 12 surgically resected tumors of the combined type of small-cell lung cancer. Ten cases (83%) expressed Bcl-2 oncoprotein within the tumor tissues. Two of them showed its expression in both the small cell carcinoma and non-small cell carcinoma types, and 7 cases exhibited Bcl-2 expression only in the portion of the small cell carcinoma. Considering previous reports indicating a high prevalence of Bcl-2 oncoprotein expression in small cell lung cancer, it is suggested that Bcl-2 oncoprotein even in the combined type of lung cancer may play an important role in tumorigenesis and tumor development and ensuing histological alterations between small cell carcinoma and non-small cell carcinoma types.

Aged↗

Clinical significance of pressor responses to laboratory stressor testing in hypertension.

We investigated the relation between pressor responses to laboratory stressors and 24-hour blood pressure (BP) variability or left ventricular mass. Mental arithmetic tests, isometric hand grip exercise, and bicycle ergometer exercise were carried out in middle-aged normotensive subjects (n=10) and in age-matched WHO stage I (n=23) and stage II (n=11) patients with essential hypertension. Mental arithmetic was associated with a greater rate of increase in plasma epinephrine than in norepinephrine, and handgrip exercise was associated with a greater rate of increase in plasma norepinephrine than in epinephrine in all three groups. Bicycle ergometer exercise caused a remarkable increase in plasma norepinephrine and a mild increase in plasma epinephrine in all three groups. In mental arithmetic tests, pressor responses of hypertensive patients were significantly greater than those of normotensives. The pressor response during mental tests was significantly correlated with the value of 24-hour BP variability in all subjects (r=0.56, p< 0.01). The pressor response to handgrip increased with the stage of hypertension. A good correlation existed between the pressor response to handgrip and the left ventricular mass index in the subjects (r=0.73, p < 0.001). There was no difference in the pressor response to ergometer exercise between any of the groups. The findings suggest that the pressor response to mental stress reflects BP variability and that the response to handgrip is correlated with target-organ disease associated with hypertension, especially the degree of cardiac hypertrophy.

Adult↗

A long-term cohort study of the atomic-bomb survivors.

The Atomic Bomb Casualty Commission (ABCC), the predecessor of the Radiation Effects Research Foundation (RERF), was established in 1947 to conduct long-term, comprehensive epidemiological and genetic studies of the atomic-bomb (A-bomb) survivors. Today this study still depends upon the voluntary cooperation of several tens of thousands of survivors of the bombings of Hiroshima and Nagasaki. An in-depth follow-up study of mortality in the study population of 120,000 persons, including A-bomb survivors and controls, has continued since 1950. The study of tumor incidence was initiated through record linkage with a tumor registry system in Hiroshima and Nagasaki in 1958. In the same year, biennial medical examinations of 20,000 individuals began. Follow-up studies also have been conducted on in-utero-exposed persons and first-generation offspring of the survivors. On the basis of these studies spanning nearly half a century, we know that the occurrence of leukemia and cancers associated with A-bomb radiation is higher than among the non-exposed. Among the A-bomb survivors, radiation cataracts, hyperparathyroidism, delayed growth and development, and chromosomal aberrations also occur more often. However, to date no evidence exists of genetic effects in the children of A-bomb survivors. It should be kept in mind that such study results could never be obtained without the cooperation of A-bomb survivors.

Aged↗

[Familial hypertrophic cardiomyopathy generating a marked left ventricular pressure gradient in an 82-year-old woman].

Familial nonobstructive hypertrophic cardiomyopathy in 78-year-old woman was diagnosed in 1988. Since then she has been treated with a beta-blocking drug and a calcium antagonist. Her clinical condition was NYHA I or II for several years. Echocardiography revealed asymmetric septal hypertrophy in 1988 (interventricular septal thickness = 21 mm, posterior wall thickness = 10 mm). Systolic anterior motion of the mitral valve was first observed at the end of 1992. The left ventricular pressure gradient also gradually increased; it was about 138 mmHg in 1993 (age 82 yrs). The left ventricular ejection time index increased from 376 msec in May, 1992 to 459 msec in May, 1994. In September, 1994, the patient's condition gradually deteriorated (NYHA IV), and she was admitted to our hospital. To attenuate the left ventricular pressure gradient, 150 mg of disopyramide was administered. Her condition markedly improved: the left ventricular pressure gradient decreased from 180 mmHg to 76 mmHg, and the left ventricular ejection time index decreased from 485 msec to 419 msec. These results indicate that a left ventricular pressure gradient can be generated rapidly even in a very old patient, and that disopyramide may be useful to attenuate the left ventricular pressure gradient.

Aged↗

[A 66-year-old woman with a patent ductus arteriosus and no significant progression of pulmonary arterial pressure over 17 years].

We report the case of a 66-year-old woman with a patent ductus arteriosus and no significant progression of pulmonary arterial pressure over 17 years. She was admitted to our hospital in 1978 because of palpitations on exertion and chest discomfort. Cardiac catheterization was done, and she was given a diagnosis of patent ductus arteriosus. Because the left-to-right shunt was small (15%) and because there was no evidence of pulmonary hypertension (38/18 mmHg), she was treated medically. In 1995 she was admitted again, to determine the cause of a cerebral infarction. The cerebral infarction was believed to have been caused by an embolism due to atrial fibrillation. She underwent cardiac catheterization again. The left-to-right shunt had increased to 41%, but the pulmonary artery pressure had not changed (27/14 mmHg). Intravascular ultrasound imaging was used to evaluate the ductus arteriosus. The diameter of the ductus was 4.4 mm and calcification was not observed. During the 17 years of follow-up, heart size increased slightly, but pulmonary artery pressure did not change. In addition, intravascular ultrasound was very useful for evaluating the condition of the ductus arteriosus.

Aged↗

[Successful combination chemotherapy including deoxycoformycin in a case of cutaneous T cell lymphoma].

A 44-year-old woman was admitted to our department because of fever and skin eruptions on August, 1991. Physical examination revealed superficial lymph node swelling, hepatosplenomegaly and generalized erythroderma. Laboratory findings were as follows; WBC 21,490/microliters with 67% lymphocytes including flower cells. The surface phenotype of lymphocytes was positive for CD2, CD4, CD25, CD29 suggesting helper-inducer T cell. Skin and lymph node biopsies revealed the infiltration of T cells with indented nuclei. Anti-HTLV-1 antibodies in the serum and HTLV-1 proviral DNA analysis by PCR method were negative. She was diagnosed as CTCL, and she was treated with prednisolone. However, her erythroderma deteriorated gradually, in spite of well-controlled lymphocyte counts. Combination chemotherapy, utilizing vincristine, etoposide and cyclophosphamide, was effective against organomegaly but not against generalized erythroderma. After DCF was initiated at a weekly dose of 7.5 mg, her erythroderma improved rapidly and markedly with the disappearance of severe itching, and she achieved complete remission. Our results suggest that DCF is beneficial for chemotherapy-resistant generalized erythroderma in CTCL.

Adult↗

Prevalence of skin neoplasms among the atomic bomb survivors.

About 7,000 atomic bomb (A-bomb) survivors from Hiroshima and Nagasaki who participate in the Radiation Effects Research Foundation (RERF) Adult Health Study (AHS) were examined to define the relationship between skin neoplasms and exposure to ionizing radiation. Careful clinical inspection of the skin was undertaken to detect not only skin cancer but precancerous lesions such as senile keratosis. Five cases of basal cell carcinoma, five cases of senile keratosis and one case of Bowen's disease were confirmed histologically among 5955 A-bomb survivors for whom Dosimetry System 1986 (DS86) dose estimates are available. The relationship between the combined prevalence of skin cancer and precancerous lesions and DS86 dose was examined together with other factors that might affect skin neoplasms including occupational exposure to ultraviolet (UV) rays, age, sex and city. The prevalence of basal cell carcinoma and senile keratosis increased as the DS86 dose increased. The prevalence of skin cancer and senile keratosis among persons engaged in work involving frequent exposure to UV rays was higher than among those who were not engaged in such work. Sex and city were not significantly related to those skin diseases. Odds ratios of skin neoplasm for a 1-Gy dose, occupational exposure to UV rays and age at time of examination (in 10-year increments) are 1.7, 5.9 and 1.9, respectively.

Adult↗

[A case of crescentic glomerulonephritis with extensive hematuria resulting in severe anemia].

A 24-year-old woman was admitted to our hospital because of macroscopic hematuria with clotting. She had been well until two months before admission, when she experienced fever, arthralgia and lethargy and entered another hospital. Laboratory tests showed macroscopic hema-turia, anemia and mild renal dysfunction. Two weeks prior to admission, she had experienced an episode of macroscopic hematuria with clotting followed by severe anemia requiring blood transfusion. Because of the deterioration of her renal function, she was transferred to our hospital. Examinations to determine the source of bleeding from the urinary tract, including a renal arteriogram, were negative. Tests for c-anti-neutrophil cytoplasmic antigen (ANCA) and anti-glomerular basement membrane antibody gave negative results, whereas the test for p-ANCA was positive. Renal biopsy revealed crescentic glomerulonephritis with focal necrosis. Therefore, we diagnosed rapidly progressive glomerulonephritis (RPGN) due to ANCA-associated renal disease. As a result of methypre-dnisolone pulse treatment followed by oral steroid therapy, macroscopic hematuria disappeared with marked improvement of her renal function. We considered this patient to be a rare case of RPGN with blood loss through glomerular lesions resulting in severe anemia.

Adult↗

Profiles of non-cancer diseases in atomic bomb survivors.

This article summarizes the results of a recent study of atomic bomb radiation and non-cancer diseases in the AHS (Adult Health Study) population by the RERF (Radiation Effects Research Foundation) along with a general discussion of previous studies. The association of atomic bomb radiation and CVD was examined by incidence studies and prevalence studies of various endpoints of atherosclerosis, such as MI, stroke, aortic arch calcification, isolated systolic hypertension, and pulse wave velocity, and, although the excess was small, all endpoints indicated an increase of CVD in the heavily exposed group. Because of the consistency of the results, it is almost certain that CVD is higher among atomic bomb survivors. However, all CVD risk factors associated with lifestyle had not necessarily been adjusted for in studies to date, and it is difficult at present to conclude that the increase in CVD among survivors was a direct effect of radiation. Recent studies have demonstrated almost certainly that uterine myoma is more frequent among atomic bomb survivors. It cannot, at present, be concluded that uterine myoma is caused by radiation, because there are no reported studies of other exposed populations. Further analyses including the role of confounding factors as well as molecular approaches are needed to verify this radiation effect. The relationship between atomic bomb radiation exposure and hyperparathyroidism can now be said to have been established in view of the strong dose response, the agreement with results of studies of other populations, the high risk in the younger survivors, and the biological plausibility. Future studies by molecular approaches, etc., are needed to determine the pathogenic mechanism. Among other benign tumours, a dose response has been demonstrated for tumours of the thyroid, stomach and ovary. Although fewer studies have been conducted than for cancer, a clear association between radiation and various benign tumours is emerging. Concerning the association between atomic bomb radiation exposure and chronic liver diseases, the recent incidence study of members of the AHS population demonstrated a significant dose response. Both chronic hepatitis and cirrhosis were suggested as being associated with exposure. The possibility that the increased occurrence of chronic liver diseases among the survivors may be due to hepatitis virus infection cannot be excluded, and the results of the ongoing hepatitis C virus antibody titre studies are awaited.

Cardiovascular Diseases↗