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Biomedical subjects

K Hayashida

Publications and source records attributed to K Hayashida.

At least 235 records · Page 13Linked to original sources

Two patients with meningioma visualized as high uptake by SPECT with N-isopropyl-p-iodo-amphetamine (I-123).

It has been reported that brain tumors show decreased IMP uptake, however, we encountered two cases of meningioma which had initially increased IMP uptake. SPECT was performed at 30 min, 2 hr and 6 hr after intravenous administration of IMP (3 mCi). The delayed images (2 and 6 h) showed decreased IMP uptake. These were convexity and parasagittal meningiomas which had tumor stains at angiography. Although the mechanism of IMP uptake in brain tumor is still unclear, this finding should be considered in the interpretation of IMP-SPECT.

Adult↗

Hepatitis B virus DNA polymerase activity and hepatitis B e antigen (HBeAg)/anti-HBe status among type B chronic liver diseases.

To investigate the relationship between hepatitis B virus (HBV) replication and chronic liver disease, age-specific prevalences of HBeAg, anti-HBe, and HBV DNA polymerase (DNAP) activity were studied in 295 asymptomatic HBV carriers and 183 patients with B-type chronic liver diseases. DNAP activity decreased with age, and there was no difference in the overall prevalence of DNAP activity between the asymptomatic carriers (27.8%) and the chronic liver disease patients (27.3%). The prevalence of DNAP activity in the 40-and-over age group was significantly higher for the chronic liver disease patients (17.5%) than for the asymptomatic carriers (1.7%). The prevalence of HBeAg in the 40-and-over age group was also significantly higher for the chronic liver disease patients (33.8%) than for the asymptomatic carriers (2.6%). These data suggest that viral replication decreased with age and that viral replication occurring in older persons closely related to chronic liver disease.

Age Factors↗

Kupffer cells may autoregulate interleukin 1 production by producing interleukin 1 inhibitor and prostaglandin E2.

Rat Kupffer cells stimulated with bacterial lipopolysaccharide (LPS) produced high levels of interleukin 1 (IL-1), as determined by thymocyte proliferation assay. Indomethacin revealed a dose-dependent augmentation in IL-1 production, in parallel with a dose-dependent reduction in prostaglandin E2 production by Kupffer cells. The addition of exogenous prostaglandin E2, dibutyryl cAMP, or isoproterenol led to a dose-dependent suppression of IL-1 production. The supernatant from LPS-stimulated Kupffer cells also contained factors that inhibited IL-1-induced thymocyte proliferation. Upon gel filtration, two inhibitory peaks, at apparent MW of 27,000 and 6000, were obtained. The latter but not the former fraction also affected interleukin 2 (IL-2)-induced thymocyte proliferation. Increasing amounts of IL-1 overcame the inhibitory activity derived from the 27,000 MW fractions. These results suggest to us that prostaglandin E2 and IL-1 inhibitor released by Kupffer cells may be involved in negative self-control in regulating IL-1 production and its action.

Animals↗

Random exercise stress test in diagnosing effort angina.

To improve the performance of exercise stress testing in the diagnosis of effort angina while minimizing risks of serious complications, we evaluated an impulse response of ST changes, which is a transient ST response resulting from a hypothetical, strenuous-impulselike exercise, without actually imposing the strenuous load. To obtain the impulse response, subjects walked intermittently according to a computer-generated random binary sequence on a treadmill for 20 minutes (with a constant speed of 1.7 mph and a slope of 10%). We used Fourier transform for beat-to-beat changes in ST level and the binary sequence of exercise. We then determined the transfer function by taking the ratio of Fourier transformed ST level to exercise over the frequency range of 0.5 through 5.0 cycles/min. Converting the transfer function to the time domain yielded the impulse response of ST change. The subjects consisted of 49 patients (60 +/- 9 years) with effort angina, 13 patients with atypical chest pain (56 +/- 9 years), and 30 healthy, male volunteers (23 +/- 7 years). In 82 subjects (89%), the ST impulse response showed an initial depression followed by a smooth, gradual restoration toward the preexercise ST level (type I response). The average duration of the initial depression was 8 +/- 3 seconds in the healthy volunteers, whereas it was significantly prolonged to 23 +/- 14 seconds in effort angina (p less than 0.05). The depression in patients with atypical chest pain was not significantly different from that in the healthy volunteers.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Production of hepatocyte stimulating factor of rat Kupffer cells induced by lipopolysaccharide: partial characterization and effects on alpha 2 macroglobulin gene expression in cultured adult rat hepatocytes.

Primary cultured rat Kupffer cells stimulated with lipopolysaccharide (LPS) produced a hepatocyte stimulating factor (HSF), which enhanced the synthesis of acute phase protein, alpha 2-macroglobulin (alpha 2M), in adult rat hepatocytes. The Kupffer cell derived-HSF (KC-HSF), enhanced the synthesis of alpha 2M over 100 fold by primary cultured adult rat hepatocytes, in the presence of dexamethasone (Dex). The synthesis of albumin was not stimulated by the factor, even in the presence of Dex. The alpha 2M mRNA increased exponentially starting at 3 hr after addition of the factor. Therefore, the synthesis of alpha 2M stimulated by KC-HSF is probably controlled at the pretranslational phase. The LPS stimulated production of the KC-HSF was inhibited by actinomycin D. The HSF was precipitated between 35% and 65% saturation with ammonium sulfate and collected in the over 30,000 daltons fraction, by molecular sieving. Sephacryl S-200 gel chromatography revealed two distinct forms of HSF with apparent molecular weights of approximately 30,000 and 100,000 daltons. The majority of the activity was recovered in the latter fraction. Isoelectric chromatofocusing of the 100,000 daltons form of HSF yielded a single peak of activity with an apparent isoelectric point (pI) of 4.2. Each fraction contained the interleukin-1 (IL-1) activity, determined by thymocyte proliferation assay. These results show that Kupffer cells produce a cytokine, KC-HSF with IL-1 activity but different properties, as seen on the on Sephacryl S-200 gel filtration and isoelectrofocusing from known mouse or human IL-1.

Animals↗

[A case of HBs antigen negative hepatocellular carcinoma without liver cirrhosis in a young woman].

A 27-year-old woman, post parturition, was admitted to hospital because of epigastric pain. Ultrasonography and abdominal computerized tomography revealed a giant mass in the left lobe of the liver. Celiac angiography showed a hypervascular mass with irregular vascularity. Serum HBs antigen proved negative. A left hepatic lobectomy was performed in March, 1985. Histology of the tumor revealed the trabecular type of a hepatocellular carcinoma with Edmondson grade 2 atypism, whereas the non-cancerous region of the liver showed chronic inactive hepatitis. This case is presented, because of the rarity of a hepatocellular carcinoma developing in such a young patient. In addition, reported cases of a hepatocellular carcinoma in the young in Japan are reviewed.

Adult↗

Intracardiac malignant lymphoma detected by gallium-67 citrate and thallium-201 chloride.

An abnormal uptake of 67Ga and 201Tl in the right atrium was observed initially in a 77-yr-old man with superior vena cava syndrome. The pathological diagnosis of the surgically resected specimen was non-Hodgkin's malignant lymphoma in the right atrium. Thallium-201 is used as an imaging agent for malignant tumors. However, previous reports suggested that 201Tl scintigraphy may not be a useful method to detect cardiac involvement in patients with malignant neoplasms. In this case both 201Tl and 67Ga accumulation was observed in the intracardiac tumor by scintigraphy.

Aged↗