Publications by authors named "Kojiro Koyama"

We confirmed infection of 2 patients with Borrelia miyamotoi in Japan by retrospective surveillance of Lyme disease patients and detection of B. miyamotoi DNA in serum samples. One patient also showed seroconversion for antibody against recombinant glycerophosphodiester phosphodiesterase of B.

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Background: : Radiation exposure is an established cause of clinical thyroid cancer, but little is known about radiation effects on papillary microcarcinoma (PMC) of the thyroid, a relatively common subclinical thyroid malignancy. Because the incidence of these small thyroid cancers has been increasing, it is important to better understand them and their relation to radiation.

Methods: : PMCs were identified in a subset of 7659 members of the Life Span Study of atomic bomb survivors who had archived autopsy or surgical materials.

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In papillary thyroid carcinogenesis, the constitutively activated mitogen-activated protein (MAP) kinase signaling pathway caused by a genetic alteration such as RET/PTC rearrangement or mutation of RAS and BRAF genes, is thought to be a major early event. Among these, the recently identified BRAF(V600E) mutation has been found at high frequency in adult patients with papillary thyroid carcinoma (PTC). However, the association between this mutation and radiation exposure in adult PTC is still unknown.

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Objective: To examine the association between the incidence of gastric cancer and lifestyle factors such as cigarette smoking, alcohol drinking, and diet as well as atomic bomb radiation exposure.

Methods: Longitudinal study including 38,576 atomic-bomb survivors in Hiroshima and Nagasaki, Japan, followed-up between 1980 and 1999. Individual radiation dose was estimated according to the Dosimetry System 1986 (DS86).

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Skin cancers, though rare in Japan, have reportedly been on the rise, but little else is known about epidemiologic features of different histologic types of skin cancer. The Life Span Study cohort, which consists of 93,700 atomic-bomb survivors, many of whom were exposed to negligibly low radiation doses, and 26,600 people not exposed to radiation, enables a population-based study of spontaneous as well as radiation-related cancer risk. Skin tumor incident cases diagnosed between 1958 and 1987 were ascertained by linkage to the Hiroshima and Nagasaki tumor registries augmented by searches of other data sources.

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Background And Aims: It has been hypothesized that some aspect of a traditional 'Asian' diet, that is low in animal products and high in soya, may be associated with a reduced risk of prostate cancer. This study aimed to examine the association between dietary intake and prostate cancer risk among 18,115 men in Hiroshima and Nagasaki, Japan, using prospective data from the Life Span Study.

Methods: Subjects completed a food-frequency questionnaire at baseline (1963, 1965 and/or 1979) and were followed for incident prostate cancer until the end of 1996.

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An incidence survey of the Life Span Study (LSS) population found 1093 breast cancers among 1059 breast cancer cases diagnosed during 1950-1990. As in earlier breast cancer surveys of this population, a linear and statistically highly significant radiation dose response was found. In the analysis, particular attention was paid to modification of radiation dose response by age at exposure (e) and attained age (a).

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Our objective was to examine whether parental exposure to atomic bomb radiation has led to increased cancer and/or noncancer mortality rates among the offspring. We studied 41,010 subjects born from May 1946 through December 1984 (i.e.

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