Biomedical subjects

N Hamajima

Publications and source records attributed to N Hamajima.

At least 109 records · Page 6Linked to original sources

PubMed1997

[A nonparametric estimation of survival curve with interval censored data].

Although survival analysis dealing with right-censored data has enjoyed wide use, analysis of data with left-censored and interval censored cases is available only to a very limited number of clinical researchers because of the difficulty in understanding the concepts and performing the calculations. This paper applies Turnbull's self-consistency algorithm, which he applied in his paper on survival data with only left-censored cases, for nonparametric estimation of survival curve including both left and interval censored data. A difference in the estimates of survival rate among different modes of calculation was demonstrated using the data from the Hematopoietic Cell Transplantation Registry of the Japan Society for Hematopoietic Cell Transplantation, which illustrated the necessity of a correct analysis.

Algorithms↗

PubMed1996

A novel gene family defined by human dihydropyrimidinase and three related proteins with differential tissue distribution.

We have isolated cDNA clones encoding dihydropyrimidinase (DHPase) from human liver and its three homologues from human fetal brain. The deduced amino acid (aa) sequence of human DHPase showed 90% identity with that of rat DHPase, and the three homologues showed 57-59% aa identity with human DHPase, and 74-77% aa identity with each other. We tentatively termed these homologues human DHPase related protein (DRP)-1, DRP-2 and DRP-3. Human DRP-2 showed 98% aa identity with chicken CRMP-62 (collapsin response mediator protein of relative molecular mass of 62 kDa) which is involved in neuronal growth cone collapse. Human DRP-3 showed 94-100% aa identity with two partial peptide sequences of rat TOAD-64 (turned on after division, 64 kDa) which is specifically expressed in postmitotic neurons. Human DHPase and DRPs showed a lower degree of aa sequence identity with Bacillus stearothermophilus hydantoinase (39-42%) and Caenorhabditis elegans unc-33 (32-34%). Thus we describe a novel gene family which displays differential tissue distribution: i.e., human DHPase, in liver and kidney; human DRP-1, in brain; human DRP-2, ubiquitously expressed except for liver; human DRP-3, mainly in heart and skeletal muscle.

Amidohydrolases↗

PubMed1996

Molecular cloning and sequencing of a cDNA encoding dihydropyrimidinase from the rat liver.

A cDNA encoding dihydropyrimidinase has been isolated from a rat cDNA library. The N-terminal and an internal amino acid sequences were determined, and PCR primers were designed based on these sequences. Using a cDNA fragment amplified by RT-PCR with these primers, three cDNA clones were isolated from a rat liver library. The clone with the longest insert of 2129 bp contained a 1557 bp open reading frame encoding a polypeptide of 519 residues with a molecular mass of 56,832 Da.

Amidohydrolases↗

PubMed1996

Patients' expectations of information provided at cancer hospitals in Japan.

In order to survey patients' views on disease and treatment information that should be provided at hospitals, an anonymous self-administered questionnaire was distributed to patients at Aichi Cancer Center Hospital in 1995. All eligible first-visit outpatients (97 persons), randomly selected revisit outpatients (99 persons; about one in ten refused), and all except six eligible inpatients in good condition at discharge (97 persons) responded. Out of 293 patients (115 males, 174 females and 4 unspecified), 74% answered that they wanted to be informed of their diagnosis irrespective of circumstances, 20% answered that they would want to be informed only in certain circumstances, and 2% did not want to be informed at all. There were no significant differences in response among the three sources of patients. Inpatients wanted more (81%) to be explained about recommended therapy than either first-visit outpatients (67%) or revisit outpatients (67%). The majority considered that about a 30-minute explanation was needed using pamphlet-like written materials or video. When asked what information was needed when choosing a cancer hospital, 71% specified information on the specialty of the hospital, 57% the content of the care provided, 23% the name and specialty of the doctors, 20% the waiting period before scheduled admission, 13% the average admission period, 11% the number of patients with the same disease, 10% the waiting time at the outpatient clinic, 6% the meal menu, and 4% the number of private wards. Forty-three percent wanted an information service covering all hospitals in the region through an information center. The results revealed that patients at this cancer hospital required information on their disease, treatment, and hospital specialty.

Adult↗

PubMed1996

Tobacco, alcohol and dietary factors associated with the risk of oral cancer among Japanese.

The mortality rate among Japanese men due to oral cancer is increasing, but risk factors among Japanese other than smoking and drinking have not been examined. To investigate the dietary factors involved in oral cancer, we conducted a hospital-based case-referent study in Aichi, Japan. Cases comprised 189 men and 77 women aged 20-79 years with one of the following cancers: tongue, mouth, oropharynx and hypopharynx. The reference group comprised 9,858 male and 26,669 female out-patients without cancer. Smoking and drinking were highly associated with an increased risk of oral cancer. Japanese sake showed a lower odds ratio (OR) than beer or hard liquor (OR= 3.6, 4.5 and 4.8, respectively). In the cross analysis between smoking and drinking, smoking combined with drinking increased the risk of oral cancer to three times that of smoking only (OR=6.2 vs. 2.2). Frequent intake of raw vegetables (OR = 0.5) and fruit (OR = 0.5) were inversely associated with the risk of oral cancer after adjustment for age, sex, smoking, drinking and year of visit. Western-style breakfast and salty food preference decreased the risk of oral cancer, and salty food preference was still statistically significant by multivariate analysis (OR= 0.7). In conclusion, smoking cessation, drinking control and frequent intake of raw vegetables and fruit among Japanese are likely to be effective preventive measures against oral cancer.

Adult↗

PubMed1996

Subsite (cervix/endometrium)-specific risk and protective factors in uterus cancer.

In Japan the incidence of cervical cancer has been high, but has recently been decreasing gradually, while the incidence of endometrial cancer is running at lower levels but is gradually increasing. To clarify the common and/or specific risk and/or protective factors of cervical cancer(CC) in contrast with endometrial cancer (EC), a comparative case-control study was conducted at the Aichi Cancer Center Hospital, Japan. In total, 556 CC cases and 145 EC cases were included and 26,751 women, confirmed as free of cancer, were chosen as the common control group. Odds ratio and its 95% confidence interval (95%CI) for each exposure variable were estimated by using an unconditional logistic regression model adjusted for age and first-visit year. Habitual smoking and experience of pregnancy increased the risk of CC, while decreasing the risk of EC. Greater body mass index (>20), daily intake of fruit and more frequent intake of boiled or broiled fish (>1-2 times/week) decreased the risk of CC, whereas they increased the risk of EC. Daily intake of milk decreased the risk of CC. The results obtained from this study suggest that several EC-increasing risk factors are in fact CC-decreasing determinants. The observed risk reduction in both CC and EC by physical exercise and dietary control for health is noteworthy from the public health standpoint and warrants further investigation.

Adult↗

PubMed1996

Analysis of 55 transplantations from unrelated volunteer donors facilitated by Tokai Marrow Donor Bank.

In October, 1989, the Tokai Marrow Donor Bank (TMDB) was established through the cooperation of patients' families, the branches of blood centers of Japanese Red Cross and the hematologists' group in Tokai Area (Aichi, Shizuoka, Gifu and Mie Prefectùres) in Japan to facilitate the procurement of suitable marrow from unrelated volunteer donors for patients lacking related donors. The number of human leukocyte antigen (HLA)-A, B typed donors totaled 3,083 and the number of patients registered for donor search totaled 1,415 by June 1992, when the activities of TMDB were transferred to the newly created Japan Marrow Donor Program (JMDP), and 55 transplanations from unrelated donors facilitated by TMDD were performed.

Adolescent↗

PubMed1996

Risk factors of thyroid cancer among women in Tokai, Japan.

To analyze the risk factors of thyroid cancer among Japanese women who generally consume much more iodine than Europeans, we conducted a hospital-based case-referent study at Aichi Cancer Center Hospital (ACCH) in Nagoya, Japan. Ninety-four female patients aged between 20-79 years with papillary or follicular carcinoma of the thyroid, and 22,666 female outpatients without cancer were used. Past history of benign thyroid mass or goiter (odds ratio: OR = 13.9) and hyperthyroidism (OR = 5.0) showed increased ORs of thyroid cancer. Thyroid cancer cases consumed coffee less frequently (OR = 0.5) and had had more experience of delivery than referents (> or = 3 times; OR = 2.5). Western style breakfast (OR = 0.5) also decreased the OR. For the multivariate analysis, past history of thyroid diseases (OR = 4.3) was positively associated with the risk of thyroid cancer and everyday coffee consumption (OR = 0.6) tended to decrease the risk. These results suggest that thyroid hormone-related factors may be involved in the risk of thyroid cancer in Japan, too. To clarify the risk involved in Japanese food, another comparative study including detailed information on iodine intake between countries and individuals is required.

Adenocarcinoma, Follicular↗

PubMed1995

Characterization of the testis-specific gene 'calmegin' promoter sequence and its activity defined by transgenic mouse experiments.

We have cloned the genomic DNA of calmegin [(1992) J. Biol. Chem. 269, 7744-7749] and analyzed its promoter region. It contained GC-rich sequences and potential binding sites for AP 2 and Sp 1, but lacked the TATA sequence. The 330 bp 5' flanking sequence of calmegin genomic DNA fused with the CAT gene was used for the study of promoter activity in transgenic mice. The CAT gene activity was detected exclusively in testes, indicating that the 330 bp calmegin 5' sequence was sufficient for the testis-specific expression. The existence of testicular nuclear factors specifically bound to the putative promoter sequence was also demonstrated.

Animals↗

PubMed1995

Subsite-specific risk factors for colorectal cancer: a hospital-based case-control study in Japan.

To investigate the subsite-specific risk factors for colorectal cancer, we conducted a case-control study, using a common questionnaire which inquired about general lifestyles over the past five years (1988-92), at the Aichi Cancer Center Hospital, Nagoya, Japan. This study compared 432 patients with histopathologically diagnosed colorectal cancer (94 proximal colon [cecum, ascending colon, transverse colon]; 137 distal colon [descending colon, sigmoid colon]; 201 rectum [rectosigmoid, rectum]); and 31,782 first-visit outpatient controls who were free from cancer. In both genders, habitual smoking selectively increased the risk for rectum cancer. Soft or loose feces increased the risk for all subsites of colorectal cancer, particularly in female rectum cancer (odds ratio [OR] = 4.5). Among female dietary habits, Japanese-style foods decreased the risk for distal colon cancer, but increased the risk for proximal colon cancer. These results suggested that the risk factors for colorectal cancer differ by subsite among such a low-risk population as the Japanese. It is suggested also that 'irritable bowel' (soft or loose feces) might be associated with distal subsites of colorectal cancer, independently or combined with habitual smoking.

Adult↗

PubMed1995

A large-scale, hospital-based case-control study of risk factors of breast cancer according to menopausal status.

We conducted a large-scale, hospital-based case-control study to evaluate differences and similarities in the risk factors of female breast cancer according to menopausal status. This study is based on a questionnaire survey on life style routinely obtained from outpatients who first visited the Aichi Cancer Center Hospital between January 1, 1988 and December 31, 1992. Among 36,944 outpatients, 1,186 women with breast cancer detected by histological examination were taken as the case group (607 premenopausal women and 445 postmenopausal women) and 23,163 women confirmed to be free of cancer were selected as the control group. New findings and reconfirmed factors of breast cancer were as follows. 1) The risk of at least one breast cancer history among subjects' first-degree relatives was relatively high among pre- as well as post-menopausal women. 2) A protective effect of physical activity against breast cancer was observed among both pre- and post-menopausal women. 3) Dietary control decreased the risk of premenopausal breast cancer. 4) Current smoking and drinking elevated the risk of breast cancer in premenopausal women. 5) Decreasing trends of breast cancer risk were associated with intake of bean curd, green-yellow vegetables, potato or sweet potato, chicken and ham or sausage in premenopausal women, while in postmenopausal women a risk reduction was associated with a more frequent intake of boiled, broiled and/or raw fish (sashimi). Further study will be needed to clarify the age group- and/or birth cohort-specific risk factors for breast cancer among the young generation in Japan.

Adult↗

PubMed1995

A modified landmark method for dealing with an event observed during a follow-up period.

Events observed during a follow-up period are generally more informative when predicting the prognosis of patients than the clinical data available at the start of follow-up. The present paper has aimed to introduce a modified landmark method for estimating a survival curve for patients in whom an event related to their survival had occurred at a given landmark time during the follow-up period. Survival curves were compared graphically by the conventional method, the Mantel-Byar method, the landmark method and the modified landmark method. The subjects were ninety-five patients with myelodysplastic syndrome who had been diagnosed between 1979 and 1992 at Tokyo Medical College Hospital, and followed-up until September, 1993. Disease evolution was used as the event. The survival curves for patients with and without the event, calculated by the conventional method, were biased and not applicable to the actual patients at the start of follow-up before the occurrence of the event. The curves obtained using the Mantel-Byar method were not biased but similarly not applicable to the actual patients. The landmark method gave unbiased curves applicable to patients with and without the event at a given landmark time, but the curve for those with the event included a lead time from the onset of the event to the landmark time. The modified method gave an unbiased estimation of survival for patients in whom the event had just occurred around a given landmark time.

Disease Progression↗

PubMed1995

[Status quo and problems in phase III trials: view of a trialist].

The quality of clinical trials in Japan has been improving through clear protocol preparation, improvements in methodology, coordinating systems, and so forth. In order to further improvement, the following are discussed: 1) dilemmas regarding adherence of treatment determined by protocol, 2) hospital policy and physician's discretion, 3) systems to support randomized controlled trials in hospital, and 4) systems to help obtain informed consent from subjects.

Antineoplastic Agents↗

PubMed1994

Case-control studies: matched controls or all available controls?

In order to realize the variation in the estimate of the odds ratio from case-control studies, results from individually matched sampling were compared with those from the analysis based on a large number of controls. The subjects were selected from those who visited Aichi Cancer Center Hospital from 1988 to 1990. Cases consisted of 251 male lung cancer patients aged 40-79 years. Age and year of visit matched controls were sampled independently 100 times and 5000 times from non-cancer male outpatients (cases to controls ratio: 1:1, 1:2, 1:3, and 1:4). As unmatched controls, all male non-cancer outpatients aged 40-79 years (4100 patients) were used. The smoking habit was adopted as an exposure variable. As logically expected, analysis based on 4100 male controls gave a steadier estimate than the matched analyses examined here, indicating that a matched sampling is not recommended when a large number of controls are available.

Adult↗

PubMed1994

[A comparative clinical study on flucytosine alone and in combination with fluconazole in hematological malignancies: a multicenter study using the envelope method].

Two different flucytosine (5-FC) treatment regimens, one by itself and the other in combination with fluconazole (FLCZ) were compared in chemotherapy against mycotic infections in 60 patients with hematological diseases. The patients in a randomized fashion were assigned to the two treatments. In the combination regimen, the two drugs were used in half doses. beta-D-Glucan and D-arabinitol in the sera of patients were measured to document mycotic infections, and bacterial examinations were also performed. The efficacy of the combination therapy was 60.0% (18/30) and that of 5-FC alone was 65.5% (19/29). The stratified evaluation indicated that no factor was found to contribute to the efficacy in the two treatments with statistical significance. The side effects occurred in few cases and none of those was serious; including, one case of subjective symptom in each groups and two episodes of liver dysfunction in combination treatment. Changes in beta-D-glucan concentrations in the sera reflected well the pathophysiology of mycotic infections and clinical improvement. These results suggested that a combination of 5-FC and FLCZ at half doses provided a clinical benefit comparable to 5-FC alone at the ordinary dose, and the safety was considered satisfactory.

Adult↗

PubMed1994

[Analysis of therapeutic prognosis of primary open-angle glaucoma by the proportional hazards model and the life-table method].

We retrospectively analyzed the therapeutic prognosis of primary open-angle glaucoma by the life-table method and the proportional hazards model. One hundred and eight patients (202 eyes) were studied. The follow-up period ranged from 6 to 125 months (40 +/- 25 months: mean +/- SD). The Kaplan-Meier life-table method indicated that therapeutic prognosis was significantly related to pretreatment intraocular pressure (IOP) and visual field defect, and that more intensive treatment was needed for higher IOP and more deteriorated visual field defect. Analysis by the proportional hazards model showed that pretreatment IOP and mean deviation (MD) measured by static perimetry were significant prognostic factors for non-surgical treatment and that the hazard ratios were 1.29-1.31 for a 5 mmHg rise in IOP and 1.44-1.83 for a 10 dB fall in MD. We concluded that the therapeutic prognosis of primary open-angle glaucoma is highly related to the level of IOP and the severity of visual field defect at the time of diagnosis.

Adult↗

PubMed1993

Multivariate evaluation of prognostic determinants for renal cell carcinoma.

To clarify the relative importance of clinicopathological factors affecting survival in patients with renal cell carcinoma, univariate and multivariate analyses by Cox's proportional hazards model were performed for 121 patients undergoing nephrectomy between 1980 and 1991. The 5-year survival rate was 67% for all 121 patients. Univariate analysis revealed that distant metastasis, local invasion, venous involvement, infiltration pattern, grade, lymph node metastasis, sex, and tumor size were significantly associated with patient survival. Multivariate analysis using a method of stepwise selection revealed that presence or absence of distant metastasis is the most significant determinant (p < 0.0001) for survival, followed by venous involvement (p < 0.001), treatment period (p < 0.02) and local invasion (p < 0.02), in this order. A four-factor model of the above determinants yielded adjusted hazard ratios of 5.3 for distant metastasis (positive vs. negative), 3.7 for venous involvement (pV1a-pV2 vs. pV0), 3.9 for treatment period (1980-1984 vs. 1985-1991), and 3.1 for local invasion (pT3-pT4 vs. pT1-pT2). The present study revealed recent improvements in the patient survival and justified the clinical application of Robson's staging system implying local invasion, venous thrombus formation and distant metastasis as prognostic determinants.

Adult↗

PubMed1992

["Karoshi" and causal relationships].

This paper aims to introduce a measure for use by physicians for stating the degree of probable causal relationship for "Karoshi", ie, a sudden death from cerebrovascular diseases or ischemic heart diseases under occupational stresses, as well as to give a brief description for legal procedures associated with worker's compensation and civil trial in Japan. It is a well-used measure in epidemiology, "attributable risk percent (AR%)", which can be applied to describe the extent of contribution to "Karoshi" of the excess occupational burdens the deceased worker was forced to bear. Although several standards such as average occupational burdens for the worker, average occupational burdens for an ordinary worker, burdens in a nonoccupational life, and a complete rest, might be considered for the AR% estimation, the average occupational burdens for an ordinary worker should normally be utilized as a standard for worker's compensation. The adoption of AR% could be helpful for courts to make a consistent judgement whether "Karoshi" cases are compensatable or not.

Death, Sudden, Cardiac↗