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Biomedical subjects

N Yamaguchi

Publications and source records attributed to N Yamaguchi.

At least 595 records · Page 33Linked to original sources
PubMed1990

Imaging of propagated sites of epileptic discharges in repeated 123I-IMP SPECT scans.

Single-photon emission computed tomographic (SPECT) brain scans with N-isopropyl-(iodine-123-p-iodoamphetamine (123I-IMP) were performed twice at an interval of about 2.5 years in the interictal period in an adult patient with occipital-lobe epilepsy. The first SPECT scan showed an abnormal image of decreased 123I-IMP uptake in the right occipital lobe. This abnormal image was regarded as the primary focus of his epilepsy on the basis of its regional agreement with right-occipital spikes consistently seen in interictal electroencephalographic recordings throughout his clinical history. In the second scan, he showed multiple abnormal images of decreased uptake in the right frontotemporal lobes and left occipital lobe together with the right occipital lobe. These additional abnormal images were considered to be propagated sites of epileptic discharges.

Adult↗
PubMed1990

Histopathologic study of otitis media in individuals with head and neck tumors.

Five temporal bones, each including the eustachian tube, were obtained from five adults with advanced malignant tumors of the head and neck. The specimens were from the side on which the tumor had occurred. Otitis media had been detected clinically in two cases, and was detected histopathologically in the other three. We discuss the possibility that otitis media might have been caused by tumor invasion of the paratubal area, by postoperative inflammation in the nasopharynx, or by an inflammatory reaction of tubal structures to radiotherapy, or that these conditions may have coexisted.

Adult↗
PubMed1990

Histologic study of eustachian tube cartilage with and without congenital anomalies: a preliminary study.

We investigated histopathologically the development of the eustachian tube (ET) cartilage at a cellular level in individuals with and without congenital anomalies. Fourteen specimens were obtained from 14 individuals ranging in age from 24 weeks' gestation to 3 years who had cleft palate or trisomy 21 (Down) syndrome; the 49 specimens in the nonanomaly (control) group were from 49 individuals ranging from 26 weeks' gestation to 85 years of age. All temporal bone specimens included the ET and its accessory structures, and all were processed and stained with hematoxylin and eosin for histologic study in a routine manner. The number of cartilage cells in the midcartilaginous portion of the ET was determined by light microscopy. In all groups, cartilage cell density of the ET decreased with increasing age. However, cell density tended to be higher at all ages for individuals with cleft palate and microtia versus controls, and tended to be lower at all ages for individuals with Down syndrome.

Adolescent↗
PubMed1990

Use of tumor diameter to estimate the growth kinetics of cancer and sensitivity of screening tests.

A statistical method has been developed that is useful for studying the relationship between the growth kinetics of malignant tumors and the detection probability either through symptoms or by screening. Mathematical models that describe the distribution of pathological variables in malignant tumors, detected after various histories of screening, are derived and parameters for detection probabilities and the growth kinetics are then estimated by the maximum likelihood procedure. By this method the probabilities of detection through symptoms as well as by screening can be estimated as functions of pathological variable(s) such as tumor size. The growth rate of tumor can also be estimated from the distribution of pathological variables. The present method was applied to gastric cancer in Japan, where an annual screening program for the disease exists. The detection probability for the indirect X-ray used as the screening test was estimated to be 0.323 x (diameter)2/[1 + 0.323 x (diameter)2]. The doubling time of gastric cancer was estimated to be 2.90 months.

Cell Cycle↗
PubMed1990

Effect of EGF administration on EGF receptor mRNA in hCG producing tumor.

In this study we examined the expression of EGF receptor mRNA after EGF administration in hCG producing tumor (choriocarcinoma). We transplanted the tissue of choriocarcinoma into female nude mice and investigated the effects of EGF on the growth of tumors, the binding activity of EGF receptor and the expression of EGF receptor mRNA in the tumor tissues. Two doses of EGF 5.0 micrograms, 50 micrograms and phosphate buffered saline as a control were injected subcutaneously every day for four weeks. Removed tumors were used for immunocytochemical studies and EGF receptor mRNA investigations. HCG and EGF receptors were detected immunocytochemically in the tumor. The low dose EGF employed stimulated the tumor growth while the high dose EGF inhibited the tumor growth compared with that of the control group. The binding activity of EGF receptor and the expression of EGF receptor mRNA also changed in accordance with the stimulation or inhibition of tumor growth. The growth of hCG producing tumor by EGF administration appeared to be dependent upon the binding activity of EGF receptor and the expression of EGF receptor mRNA.

Animals↗
PubMed1990

Eustachian tube function and mastoid pneumatization.

We investigated the relationship between the Eustachian tube's ventilatory function and the pneumatization of mastoid air cells. In 65 adults (66 ears) with chronic otitis media (COM), ventilatory Eustachian tubal function was evaluated by the inflation-deflation test, while the area of mastoid air cells was measured by the rectangular method on X-ray film. Group I represents good function in both the inflation and deflation tests. Group II represents good function in the inflation test but poor function in the deflation test. Group III represents a poorly functioning Eustachian tube in both tests. The opening pressure in Group III was statistically higher than in Group I and Group II. The area of mastoid air cells in Group I was statistically larger than in Group III. There was no correlation between opening pressure and area of mastoid air cells in COM. Postoperative failure of the tympanic membrane was frequently found in Group III. We discuss the tubal function and pneumatization of mastoid air cells.

Adult↗
PubMed1990

[Tumor-degenerating factor (TDF)].

A new human fibroblast-producing factor which degenerates human tumor cells in vitro was found and designated as tumor-degenerating factor (TDF). The characteristics of the TDF were as follows: 1) The molecular weight of the TDF was estimated to be 30k by SDS-PAGE. 2) It may be basic and glycosylated. 3) Its activity was inhibited by fibronectin and, vice versa, by binding TDF molecule with fibronectin molecule. 4) Its activity was enhanced by interferons. It is possible that the TDF is an important substance concerning the interaction between tumor cells and interstitial cells.

Animals↗
PubMed1990

Cytosolic calcium mobilization and thromboxane synthesis in a human megakaryocytic leukemia cell.

The functional and biochemical characteristics of human megakaryocytic leukemia cells remain unclear. In this study, we examined cytosolic Ca2+ ([Ca2+]i) mobilization and thromboxane (TX) formation in a megakaryocytic leukemia cell line, designated CMK. Stimulation of CMK cells with thrombin resulted in an increase of [Ca2+]i as measured with the fluorescent marker Fura 2-AM. The rise in [Ca2+]i was mostly dependent on extracellular Ca2+. Prostaglandin E1 (PGE1) further increased [Ca2+]i after thrombin addition, thus indicating that PGE1 had a different action on [Ca2+]i in cells of the platelet-megakaryocyte lineage. The addition of thrombin and the calcium ionophore A23178 to CMK cells caused similar rapid formations of TXB2 as measured by RIA. Thrombin plus A23178 had a synergistic effect on TXB2 synthesis in CMK cells. Thrombin had no effect of TX metabolism in the cells with myeloid, erythroid, B-lymphoid, and T-lymphoid lineages. These results indicate that thrombin-induced TX synthesis may serve as a marker of immature megakaryocytes.

Alprostadil↗
PubMed1990

[Histidine-rich glycoprotein in blood during inflammation, surgical operation or hemodialysis].

Serum or plasma histidine-rich glycoprotein (HRGP) levels were determined in several conditions. In normal volunteers, HRGP levels did not correlate with either plasminogen contents or plasminogen activity, although HRGP has been believed to be a modulator for fibrinolysis system. In acute inflammation, HRGP levels in serum changed as a negative acute phase reactant, which was also confirmed after surgical operation. At the time of demonstrating decreased HRGP values, expression of HRGP fragment was studied using heparin-Sepharose beads. However, no new fragments were detected, suggesting that the decrease was not due to enzymatic destruction. On the other hand, in patients with rheumatoid arthritis (chronic inflammation), HRGP levels were similar to those in control subjects. As HRGP is a potent heparin antagonist, HRGP levels in plasma during hemodialysis with heparin were studied. Both levels of HRGP and albumin increased after hemodialysis in a similar degree due to concentration, indicating that turnover of HRGP was not altered in short period after heparin administration.

Acute-Phase Reaction↗
PubMed1990

[A prospective study of access to medical services following a community-based screening program].

Participants in a multiphasic screening program, 454 men and 767 women, were followed up for a period of several months (117 days on the average) in order to evaluate their needs for medical services after screening. Five hundred sixty-two (47.1%) visited outpatient clinics in the study area; 185 as continuing visits for existing diseases (prevalent), 167 because of symptoms which developed after the screening (clinical), and 65 for further investigations of abnormal findings from the screening (screened). The ratio of prevalent to incident (= clinical + screened) cases, which is related to the duration of clinical phase, was the highest in hypertensive, thyroid, ophthalmologic disorders. This indicates that health services for prevalent cases of those diseases are needed in addition to primary and secondary preventive efforts. The proportion of screened cases in the incident cases, which reflects the ability of the screening program to detect diseases in the preclinical phase, was the highest for anemia, disorders of lipid metabolism, and hypertensive disorders. The smaller proportions in dermatologic, urologic and orthopedic disorders indicate that preventive methods for these disorders should be considered in the future. In conclusion, monitoring of screening participants by prospective follow-up and analysis by two measures proposed in this study seem promising for continuing evaluation of the effectiveness of an on-going screening program. A network system of hospitals and physicians' offices should be developed, by which the information on the visits to outpatient clinics after screening is collected and analyzed periodically for monitoring.

Adult↗
PubMed1990

[Enhancement of cell growth by human interferons].

The effects of human interferons (HuIFN) on the human osteosarcoma cells were examined. HuIFN-alpha, -beta and -gamma enhanced dose-dependently the cell growth. There was no difference in the degree of the enhancement of the cell growth among HuIFN-alpha, -beta and -gamma. The higher the cell density was, the lower the degree of the enhancement of the cell growth. When HuIFN-gamma was neutralized with anti-HuIFN-gamma, the enhancement of cell growth was not found.

Adolescent↗
PubMed1990

[Induction of interleukins by mycoplasma in culture of human mononuclear leukocytes].

Mycoplasma shows a variety of effects on immune system, including the activation of macrophage, the increase in T cell cytotoxicity, and the enhancement of the proliferation and maturation of B cells, etc. As it is well known that many cytokines regulate the immune system, it is interesting to examine whether or not human peripheral blood mononuclear cells (PBMC) produce interleukin (IL) in response to mycoplasmas. In the present study, human PMBC were incubated with 7 species of mycoplasmas for 48 hours, and IL-1 beta, IL-2 and IL-6 activities in the supernatants were determined by ELISA. All the species of mycoplasmas were able to induce IL-1 beta and IL-6, although IL-2 was induced only by M. pneumoniae. These results suggest that the influence of mycoplasma infection on immune system may be partly due to the interleukins induced by mycoplasmas.

Humans↗
PubMed1990

[A case of acute tubulo-interstitial nephritis and uveitis syndrome].

We report herein the case of a 14-year-old female who has acute tubulo-interstitial nephritis (AIN) associated with bilateral diffuse uveitis. She was admitted for the evaluation of "proteinuria", following general fatigue and weight loss about 2 weeks ago. Her laboratory data showed mild anemia, hyper gamma-globulinemia, mild proteinuria, and the reduced glomerular filtration rate with the increased urinary excretion of beta 2-microglobulin. The histological examination obtained by renal biopsy showed mild edema and diffuse infiltration of mononuclear cells in interstitium without any glomerular or vascular abnormalities, which were compatible with AIN. As for the etiology of AIN, clinical investigations could not reveal any specific causes, such as bacterial and viral infections, drugs and systemic diseases. About 4 months after the onset of nephritis, she also became to suffer from bilateral diffuse uveitis. Therefore, the diagnosis of the acute tubulo-interstitial nephritis and uveitis syndrome (TINU syndrome) (Vanhaesebrouck et al., 1985) could be confirmed. In her clinical course, it was noteworthy that uveitis relapsed frequently in spite of systemic administration of prednisolone, and it took two years until uveitis cured, whereas the AIN subsided spontaneously prior to the specific treatment. In this case, characteristic findings of granulomatous uveitis was closely similar to those of sarcoidosis, which has been rarely reported in TINU syndrome. In this respect, the involvement of immune processes, especially cell-mediated, was suggested as the possible pathogenesis in this case.

Acute Disease↗
PubMed1990

[Familial history of cancer and dietary pattern, serum cholesterol, serum protein and blood hemoglobin].

The relationships between the history of cancer in parents and the dietary pattern, serum cholesterol, serum protein and blood hemoglobin were examined to assess the possible role of lifestyle transmission in the familial aggregation of cancer. Individuals with history of cancer in parents were selected from a population of 1,221 individuals. Five age- and sex-matched controls for each case were selected from individuals, the parents of whom were alive at the age of the case parent. Intake of miso soup, pickles and milk product showed associations with the history of cancer in parents. It was also found that serum cholesterol was significantly lower in individuals with history of cancer other than stomach in the mother. Interestingly, serum protein, especially the globulin fraction, was found to be significantly lower among individuals with the history of cancer in parents. These findings suggest that lifestyle transmission might play some role in the familial aggregation of cancer.

Adult↗
PubMed1990

Epidemiologic approaches to multiple primary cancer: critical review from the standpoints of validity and efficiency.

Epidemiologic approaches to multiple primary cancer (MPC) have been reviewed from the standpoints of validity of study design and statistical efficiency. It was shown that the expected number of MPC is often over- or underestimated when the person-year method is used in calculation. This so-called detection bias becomes stronger the poorer the prognosis of patients with their first cancer, and the longer the duration of the preclinical state of their second cancer. The bias is also affected by the probability of detecting the second cancer at the time as the first. An alternative method has been proposed, in which the prevalence rate of preclinical cancer is evaluated. The efficiency with which the increased frequency of second cancer is detected is affected not only by the risk ratio for individuals at high risk to those at low risk but also by the proportion of high risk individuals in the population.

Bias↗