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Biomedical subjects

M Kodama

Publications and source records attributed to M Kodama.

At least 703 records · Page 39Linked to original sources
PubMedDate not supplied

Neoendothelial healing of modified EPTFE grafts.

Expanded polytetrafluoroethylene (EPTFE) grafts have poor neoendothelial healing characteristics and low patency rates after long-term implantation. The authors have shown that this is due to the low porosity of currently used EPTFE grafts (20-30 microns fibril length). The inner surface coated grafts made of long antithrombogenic material fibrils (40-60 microns) are desirable, especially for small diameter grafts. The authors have implanted these surface modified grafts (coated grafts) and noncoated grafts into abdominal arteries of rats and observed good patency rates, and the effects of surface modification of the grafts on stable endothelial tissue growth. The authors used four different kinds of grafts (fibril length, 20, 40, 60, and 90 microns, respectively) to investigate the effect of porosity. High porosity (long fibril length) grafts induce good neoendothelial healing and collagen production.

Animals↗
PubMedDate not supplied

Interrelation between western type cancers and non-western type cancers as regards their risk variations in time and space. III. A contrast between bladder cancer and stomach cancer.

The present study attempted to get insight into the etiology of bladder cancer by investigating the relation of this neoplasia to other 4 cancers as regards their risk variations in time and space. The results obtained are as follows: 1) Caucasians in Western countries were more inclined to develop bladder cancer than other ethnic groups, as compared among 43 population units of the world in terms of the age-adjusted incidence rate (AAIR). 2) In the same 43 comparison sets, male populations were always higher than female populations in their bladder cancer risks. The male to female ratio for the majority of the populations ranged from 3 to 4. In some population units, the ratios were much higher. In both male and female populations, the cancer risk increased with age. 3) Bladder cancer incidence in the world has been rising during the past 20 years, as detected in the follow-up study of 16 population units. 4) A negative linear relationship was detected for both sexes between bladder cancer and stomach cancer (non-Western type) regarding their log-transformed AAIRs, as calculated with data of the same 16 population units from 1960 through 1980. The same calculation with the esophagus cancer-bladder cancer pair gave marginally negative and no correlations respectively in the male and female populations. A positive linear relationship was detected in the comparison of bladder cancer with 2 Western type cancers (cancers of the colon and lung). 5) Japanese immigrants to the US were just in between Whites in the US (high-risk populations) and native Japanese (low-risk populations) in their bladder cancer risks. The same Japanese immigrants were again just in between Whites in the US (low-risk populations) and native Japanese (high-risk populations) in their stomach cancer risks. In conclusion, bladder cancer is a Western type cancer with sex and age discriminations in its occurrence. The cancer risk also varies depending on the life style of a population (environment dependent). The results obtained are discussed from the point of view of endocrinological oncology.

Colonic Neoplasms↗
PubMedDate not supplied

The regularity of intersteroidal relations in urine as related to the law of mass action.

The relation between 14 urinary steroid excretions was investigated by intersteroidal regression analysis with urine from 59 follicular stage women, 135 luteal stage women and 5 female patients with adrenal disorders. The regularity of intersteroidal relation in urine, as detected for all steroid pairs of all groups studied, was explained in terms of the law of mass action, and a chemical equilibrium point was located with a high degree of reproducibility for each steroid and for each group. The theoretical and practical usefulness of urinary steroid regression analysis is emphasized in relation to the possible impact of multihormonal information on endocrinology.

Adrenal Gland Diseases↗
PubMedDate not supplied

Nutrition and breast cancer risk in Japan.

The present study investigated the problem of whether or not the intake of an Western-style diet will induce within the host a specified hormonal change that increases the risk for breast cancer (BC). The key observations obtained are as follows: 1) The risk for BC in Japan has been increasing for the last 20 years in parallel with the Westernization of dietary habits (increase of fat and animal protein in the diet). 2) A Japanese BC patient is distinguishable from a corresponding normal control by (a) an increase of waist/hip ratio (more specifically, an increase of abdominal fat) and (b) a decrease in the number of live births (relative infertility). Height, weight and height-adjusted weight all cannot distinguish the former from the latter. 3) The former is also distinguishable from the latter by dual steroidal disorders of ovarian dysfunction (progesterone depression) and hypercorticoidism, as revealed by a case control comparison of urinary steroid excretions. 4) The long-term maintenance of an experimental mouse on a fat-rich diet increased abdominal fat weight at an adult age, but not at a young age. 5) In the same experiment, the fat-rich diet produced a reduction of plasma progesterone at an early stage, and also produced dual changes of progesterone depression and corticosterone stimulation at a late stage of experiment. Plasma estradiol was little affected by an excess of dietary fat. 6) In an adult mouse, the weight of abdominal fat was increased by corticosterone treatment and was decreased by estradiol treatment. The suppressive effect of estradiol on abdominal fat weight was dose-dependent. In conclusion, our findings seem to suggest the possibility that a fat rich diet may produce dual steroidal disorders of ovarian dysfunction and hypercorticoidism which in turn will open the way to breast carcinogenesis by activating 2 proto-oncogens at the initiation and promotion steps.

Adult↗
PubMedDate not supplied

Interrelation between Western type cancers and non-Western type cancers as regards their risk variations in time and space. I. Mathematical linkage among multiple cancer incidences.

The present study attempted to clarify the interrelation between multiple cancer risks by comparatively investigating the age-adjusted incidence rates (AAIR) of 8 neoplasias in 20 selected populations of the world for the last 20 years. Cancers of the stomach (for both sexes) and uterine cervix were on the decline in their incidences, and cancers of the colon (for both sexes), lung (for both sexes), breast and endometrium were on the rise in the period 1960 to 1980. Cancers of the esophagus (for both sexes) and ovary exhibited little change in their incidences during this period. A negative linear relationship was detected between the log-transformed AAIR of an increasing (Western type) cancer and that of a decreasing (non-Western type) cancer, and a positive linear relationship was detected between 2 increasing or 2 decreasing cancers regarding the log-transformed AAIR. Mathematical evidence is presented to indicate that the sum of AAIRs of both increasing and decreasing cancers can be minimized within the frame of a competitive relationship. The results obtained are discussed from the view point of cancer etiology.

Female↗
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Interrelation between Western type cancers and non-Western type cancers as regards their risk variations in time and space. II. Nutrition and cancer risk.

The present study comparatively investigated the relation between the per capita consumption of various food factors and the risks of 6 cancers in 19 countries of the world. The age-adjusted death rates (AADRs) of Western type cancers (cancers of the breast, prostate, colon and lung) were positively correlated with the intakes of total calorie, meat-milk-eggs, animal protein and fats-oils, and were negatively correlated with the intake of cereals, potato etc. The AADRs of non-Western type cancers (cancers of the esophagus and stomach) showed correlations that were just the reverse of those of Western type cancers. Cancers of the lung and esophagus with low correlation coefficient (/r/less than or equal to 0.6) made a contrast with other cancers with reasonably high/r/values (0.75 or more). Cancers of the lung and esophagus were also distinguished from other cancers by an instability of male to female ratio of cancer risk, as assessed in terms of both AADR of 50 countries and age-adjusted cancer incidence rate of 83 countries of the world. It was concluded that a risk factor other than the 3 nutrient elements (carbohydrate, protein and fat) was making a contribution to both the reduction of dependency of 2 neoplasias on the intakes of 3 nutritional elements and the instability of male to female ratio in their cancer risks.

Energy Intake↗
PubMedDate not supplied

Reproductive activity is a magic spell to connect the genesis of cancers of the uterine cervix and endometrium.

The present study investigated the relation between the reproductive activity and the risk for cervical and endometrial cancers using both domestic and international materials. An association of increased risk for cervical cancer (C) with fertility at the levels of both an individual and a population was contrasted to another association of increased risk for endometrial cancer (E) with infertility at the same two levels. Both C and E patients experienced a delay of menstrual cycle (over 30 days) at high incidences (35-49%), whereas healthy controls and breast cancer patients were essentially free from such menstrual delay. The possible impact of the above hormonal characteristics of C and E patients on uterine carcinogenesis is discussed in the light of comparative endocrinology.

Age Factors↗
PubMedDate not supplied

Induction of ornithine decarboxylase activity in rat lung by neurotransmitters and peptide hormones.

Ornithine decarboxylase activity of rat lung was induced by s.c. injection of acetylcholine, norepinephrine, epinephrine, dopamine, serotonin, vasopressin, angiotensin II, and adrenocorticotropic hormone, but not by gonadotropin, aldosterone, corticosterone or hydrocortisone. The possible significance of hormonal factors in lung carcinogenesis is discussed, based on the reported promoting activity of vasopressin in cultured cells.

Acetylcholine↗
PubMedDate not supplied

Early stage detection of chemotherapeutic effect on 203 GL glioma in mice as studied by P-31 NMR and flow cytometry.

The effect of chemotherapy against glioma in mouse was evaluated by 31P NMR spectroscopy and flow cytometry. We found that administration of ACNU or tegafur at a dose less than LD50 resulted in the partial suppression of the ratio of inorganic phosphate (Pi)/phosphocreatine (PCr) and phosphomonoester (PME)/creatine phosphate (PCr) after 24 or 48 hr, although these ratios are usually increased together with growth of tumors. Flow cytometric analysis of glioma in vivo showed an accumulation in cells containing tetraploid DNA by G2M block 24-48 hr after treatment. However, the change occurred at a period slightly later than that of the Pi/PCr ratio. In contrast, histological change was noted at eight days after administration. Hence, it is concluded that in vivo 31P NMR spectroscopy can detect a change in metabolic pathways in tumors as early as 24-48 hr after the administration of chemotherapeutic agents.

Animals↗
PubMedDate not supplied

How valid is the concept of hormonal carcinogenesis in human neoplasias?

The associations of five tissue-specific steroidal disorders with five human neoplasias, as detected in our case-control studies, have been related to the genesis of each tumor. Information from epidemiology, experimental pathology and molecular biology is in support of the notion that a specified environment exerts its carcinogenic action on the target tissue through the mediating action of the steroid-generating system. The usefulness of the concept of hormonal carcinogenesis in the search for the etiology of human cancer is emphasized using information available both from our laboratory and from outside sources.

Age Factors↗
PubMedDate not supplied

Temporary arteriovenous fistula for venous reconstruction using synthetic graft: a clinical and experimental investigation.

This report discusses venous reconstructive surgery combined with a temporary distal arteriovenous fistula creation for ilio-femoral vein obstruction. One patient who had long standing, high degree edema of the left lower extremity due to postphlebitic syndrome and four patients who had acute occlusion of the iliac vein were treated by means of extra-anatomical femoro-femoral vein bypass grafting combined with temporary distal femoro-saphenous arteriovenous (a-v) fistula creation. An expanded polytetrafluoroethylene (EPTFE) graft was selected for this procedure instead of a cross-over saphenous vein. The surgically created a-v fistula was effective in keeping the implanted grafts patent for a long time in three out of the five patients. In animal experiments, the bilateral iliac veins of mongrel dogs were replaced with several kinds of synthetic graft. Femoro-femoral a-v fistulae were made only on the left side. In 26 animals, 84.6% of the synthetic grafts on the a-v fistula side were patent, whereas only 11.5% of the grafts on the control side were patent. This investigation clearly demonstrates that the increased blood flow velocity through the created distal a-v fistula preserved the patency of synthetic vein grafts.

Adult↗
PubMedDate not supplied

Interaction between oncogen activation and tumor suppressor gene activation in the genesis of five human neoplasias. A mathematical study.

The purpose of this study is to elucidate the nature of the mathematical regularity between the incidence of two particular neoplasia in their risk variations in space using world statistics. Our investigation covered 5 cancers in the tumor spectrum, 47 cancer registration units in space, and 1978 to 1982 in time. A 2 dimensional diagram was used to illustrate intercancer relationship, and log-transformed figures of the age-adjusted incidence rate (AAIR) in place of original (untransformed) figures were used as a measure of cancer risk for both statistical analysis and graphic illustration of data distribution. More specifically, the emphasis of study was on investigating the relation between the type of data distribution and the fitness of a given cancer pair to a mathematical equilibrium model under the control of the law of mass action. The results obtained are as follows: 1) A total of 7 tumor pairs investigated were divided into 3 elementary types according to their data distribution pattern-globular star cluster type, Galaxy-profile type, and open star cluster type. 2) Mathematically, the fitness of cancer pairs to the suggested equilibrium model decreased in the above order--a finding to indicate that a variety of interactions between centripetal force and centrifugal force are responsible for the production of the above data distribution types. 3) Evidence was presented to suggest that the activated oncogene system and the activated tumor suppressor gene system are the sources of the centripetal force and the centrifugal force, respectively, and that the equilibrium point of the former is very often different from the contra-equilibrium point of the latter in their locations. The pertinence of the above data interpretation is discussed in the light of recent information of oncogene/tumor suppressor gene studies.

Breast Neoplasms↗
PubMedDate not supplied

Vitamin C infusion treatment enhances cortisol production of the adrenal via the pituitary ACTH route.

The present study is an extension of our past study on the clinical use of vitamin C infusion or injection treatment in autoimmune disease and allergy which suggests that the intravenous introduction of vitamin C may enhance the activity of the endogenous cortisol in such a way as to allow clinical control of immune disorders. This time, we investigated the relation between ACTH, cortisol and vitamin C in plasma in the course of vitamin C infusion or injection treatment with and without the use of methyl-prednisolone annex, a suppressor of the homeostatic mechanism of the pituitary ACTH. A total of 4 experiments were conducted using a healthy male volunteer. Results obtained are as follows: 1) the practice of the steroid-free vitamin C infusion treatment induced a) distinct depletion of both cortisol and vitamin C from the circulation at the initial to moderate stages of the experiment, b) a small surge of plasma cortisol at the middle stage, and c) skyrocket-like rises of ACTH and cortisol of plasma at the terminal stage. 2) The use of methylprednisolone annex in the vitamin C infusion set completely suppressed the emergence of the plasma ACTH/cortisol surges of the terminal stage, but not the small surge of plasma cortisol. The synthetic steroid also suppressed the depletion of vitamin C and cortisol of the initial to moderate stages. 3) The terminal ACTH/cortisol surges of plasma were less distinct in the vitamin C infection experiment than in the vitamin C infusion experiment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Glands↗
PubMedDate not supplied

Is Linus Pauling, a vitamin C advocate, just making much ado about nothing? (Review).

Clinical use of vitamin C has been the subject of much debate in both the USA and Japan. We examine a number of topics to clarify the reasons for the confrontation of opinion between the pros and the cons as to the medical usefulness of this vitamin. We refer to our own experiences on the use of vitamin C infusion treatment for the control of either diabetes mellitus or autoimmune disease and allergy to show the importance of pharmacological considerations in the assessment of the effect of vitamin C. We also refer to a number of scientific debates to prove that a shift of paradigm is indispensable for getting a full comprehension of the benefits of vitamin C including the control of both diabetes mellitus and autoimmune disease/allergy complex.

Ascorbic Acid↗
PubMedDate not supplied

Epidemiological peculiarities of cancers of the gall-bladder and larynx that distinguish them from other human neoplasias.

The purpose of this study was to elucidate the nature of the lack of an East-West difference in both gall-bladder cancer and laryngeal cancer as regards in their risk variations in space--a property that distinguishes them from other cancers. In practice, statistical analysis was used to obtain relevant information from the IARC data book, 1978-1982. Results of key importance are as follows: 1) the epidemiological trait of gall-bladder cancer was found to be a mirror image of that of laryngeal cancer in many respects including sex-discrimination of cancer risk and the geological distribution of both high-risk and low-risk populations. 2) Paradoxically, gall-bladder cancer and laryngeal cancer shared in common a small number of populations in both their high-risk groups as well as low-risk groups. It was indicated that the 2 cancers are under the control of 2 distinct risk modifiers in their risk variations in space: the one exerts a unidirectional impact on the risks of the 2 cancers in response to a change of the outer environment. The other exerts bidirectional impacts to produce increased risk of one neoplasia and decreased risk of the other. 3) Evidence was presented to suggest that the contribution of the inactivated tumor suppressor gene to carcinogenesis compared to that of the activated proto-oncogene was larger in the independent subfamily of gall-bladder cancer and laryngeal cancer than in any of the 2 subfamilies (Western type subfamily and non-Western type subfamily). The above marker of the independent subfamily was detectable in the female populations of the world, but not in the male populations. The significance of our findings is discussed from the point of view of hormonal carcinogenesis.

Age Factors↗
PubMedDate not supplied

An essay on the nature of hormonal codes involved in the genesis of human neoplasias (review).

We have long been occupied with the motion that the steroid generating system plays a key role as the intermediator between the outer environment and the vulnerable host in the course of carcinogenesis. The purpose of this review article is to rebuild the concept of hormonal carcinogenesis in the light of the developmental flow of endocrinological oncology. Our discussion places much emphasis on the investigation of a number of puzzles surrounding the hormonal signal transmission system in humans as well as in non-human animals. The usefulness of the steroid-responsive enhancer gene/protooncogene complex model was confirmed in the construction of a unifying theory involving chemical carcinogenesis, viral carcinogenesis and hormonal carcinogenesis. We present evidence to suggest that our unifying theory surrounding the hormone-gene relationship is applicable to the genesis of human neoplasia in general, and that members of the human cancer family are interfering with each other in their risk variations in time and space. The nature of steroid substance as the signal transmitter is discussed from the point of view of paleontological endocrinology.

Adolescent↗