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Biomedical subjects

T Takashima

Publications and source records attributed to T Takashima.

At least 217 records · Page 12Linked to original sources
PubMed1990

Quantitative analysis of antiatherosclerotic effect of nifedipine in cholesterol-fed rabbits.

Reports concerning the effect of slow calcium-channel blockers on experimental atherosclerosis are controversial. We examined the antiatherosclerotic effect of nifedipine (40 mg/day for 16 weeks) on aorta of rabbits on diets containing 0.3%, 0.5%, and 1.0% cholesterol. There were no significant differences in levels of serum lipids with or without nifedipine in the same cholesterol-fed rabbits. The results obtained show that nifedipine suppressed the extent of lipid deposition and surface involvement (S.I.) in aorta in 0.3% cholesterol-fed rabbits, whereas nifedipine only tended to suppress S.I. in 0.5% cholesterol-fed rabbits and had no effect in 1.0% cholesterol-fed rabbits. The log dose-response relationship of S.I. was obtained by plotting the concentration of cholesterol in the feed or the "integrated value" of the total serum cholesterol (TC), i.e., the cumulative sum of the serum TC values obtained at each week. The log dose-response curve was shifted in parallel with the right in nifedipine groups. The Lineweaver-Burk plot constructed from the dose-response curve had the same points crossing the ordinate with or without nifedipine. These results suggested that nifedipine suppressed S.I. in a competitive manner with cholesterol on the specific binding site of lipid deposition. Electron-microscopic findings also demonstrated that fat droplets in smooth muscle cells, extracellular matrix containing collagen, and elastic fibers decreased in nifedipine-treated rabbits.

Animals↗
PubMed1990

Basophil histamine release by platelet-activating factor in aspirin-sensitive subjects with asthma.

Histamine release induced by platelet-activating factor (PAF) from leukocytes of aspirin-sensitive subjects with asthma was higher than that from normal control subjects, despite the similarity of anti-IgE-induced histamine release. Moreover, basophils of some aspirin-sensitive subjects with asthma released histamine by PAF stimulation in the absence of cytochalasin B that affects histamine release and is required in PAF-induced histamine release from leukocytes of atopic subjects with asthma and normal control subjects. In addition to temperature dependency and inhibition by ethylenediaminetetraacetic acid reported previously, PAF-induced histamine release was enhanced by cytochalasin B and indomethacin and inhibited by dexamethasone. These features are common with IgE-mediated histamine release and suggest the existence of the common pathway to PAF-induced histamine release and IgE-mediated histamine release. The results in the present study indicate the pathophysiologic significance of PAF-induced histamine release and that activation of basophils by PAF may be relevant to the pathogenesis in some aspirin-sensitive subjects with asthma.

Adult↗
PubMed1990

Production of tumor necrosis factor alpha by monocytes from patients with pulmonary tuberculosis.

We studied the production of tumor necrosis factor alpha (TNF-alpha) by peripheral blood monocytes taken from patients with pulmonary tuberculosis and from healthy controls. It was found that the monocytes from patients with newly diagnosed tuberculosis released significantly greater amounts of TNF-alpha in vitro in response to lipopolysaccharide than did those from healthy controls (P less than 0.05). However, the monocytes from patients with chronic refractory tuberculosis released significantly lower amounts of TNF-alpha than did those from patients with newly diagnosed tuberculosis (P less than 0.005). Even when the cells were primed for 24 h with 500 U of recombinant interferon gamma per ml, the same pattern of results was observed. The depressed TNF-alpha production by the monocytes from patients with chronic refractory tuberculosis was also shown in response to Mycobacterium bovis BCG. This depressed TNF-alpha production did not recover, even when cultured for 1 to 7 days in the sera of healthy individuals. The sera from patients with chronic refractory tuberculosis did not have any suppressive effect on the lipopolysaccharide-induced TNF-alpha production. Thus, it was demonstrated that the levels of TNF-alpha produced by monocytes were related to the disease states of pulmonary tuberculosis and that the depressed TNF-alpha production by monocytes in patients with chronic refractory tuberculosis might not be acquired.

Adult↗
PubMed1990

Mycobacterium avium-Mycobacterium intracellular complex-induced suppression of T-cell proliferation in vitro by regulation of monocyte accessory cell activity.

Heat-killed whole Mycobacterium avium-Mycobacterium intracellulare complex (MAC) and its lipid component impaired the capacity of human peripheral blood mononuclear cells to proliferate in vitro in response to concanavalin A (ConA), purified protein derivative of tuberculin (PPD), and to a lesser degree, phytohemagglutinin stimulation. Inhibition by MAC was not contingent upon prior exposure of the donor to MAC or other mycobacteria and occurred with lymphocytes from tuberculin-negative as well as -positive subjects. The suppression was not due to the toxicity of MAC. The suppression by MAC was not blocked by indomethacin. Adherent cell depletion and cell mixing experiments with T cells indicated that monocytes and not T cells were a major contributor to the immunosuppression observed. However, neither interleukin-1 production nor the expression of HLA-DR (Ia antigen) by monocytes was suppressed by MAC treatment. On the other hand, treatment of monocytes with MAC or MAC-derived lipid resulted in significant decreases in CD11b, a member of the leukocyte function-associated molecule-1 and LeuM3 (CD14) molecule. Anti-CD18 (beta-chain of the leukocyte function-associated molecule-1 family) monoclonal antibody had suppressive effects on ConA- and PPD- but not phytohemagglutinin-induced in vitro lymphocyte blastogenesis. We suggest that MAC and MAC-derived lipid suppress the ConA- and PPD-induced T-cell proliferations by blocking the expression of accessory molecules on the surfaces of monocytes which might be involved in nonspecific monocyte-T-cell interactions and not by inhibiting either monocyte Ia antigen expression or interleukin-1 production by monocytes.

Antigen-Presenting Cells↗
PubMed1990

Ciliated hepatic foregut cyst: radiologic features.

Ciliated hepatic foregut cysts (CHFCs) are solitary unilocular cysts in the liver that are histologically similar to bronchogenic cysts. Three cases of CHFC are reported that demonstrated radiologic features similar to those of solid masses. All the lesions were smaller than 3 cm in diameter and were subcapsular. At ultrasonography, one lesion appeared anechoic but the other two were hypoechoic. Unenhanced computed tomography demonstrated the lesions to be hyperattenuating or isoattenuating relative to surrounding liver parenchyma, and no lesions enhanced with administration of contrast material. Magnetic resonance imaging was performed in one case and demonstrated the lesion to be markedly hyperintense with a spin-echo (SE) 2,500/80 (repetition time msec/echo time msec) sequence. All the lesions were resected and found to be filled with viscous mucinous fluid. The CHFCs are not neoplasms and must be differentiated from cystic neoplasms and hypovascular solid tumors. When a subcapsular lesion demonstrated the varied appearance described, a diagnosis of CHFC should be considered.

Aged↗
PubMed1990

Adverse reactions to ionic and nonionic contrast media. A report from the Japanese Committee on the Safety of Contrast Media.

A large-scale (337,647 cases), nationwide comparative clinical study in Japan on adverse drug reactions (ADRs) to high-osmolar ionic contrast media and low-osmolar nonionic contrast media was performed prospectively. Ionic contrast media were administered in 169,284 cases (50.1%) and nonionic contrast media in 168,363 cases (49.9%). The overall prevalence of ADRs was 12.66% in the ionic contrast media group and 3.13% in the nonionic contrast media group. Severe ADRs occurred in 0.22% of the ionic and 0.04% of the nonionic contrast media examinations. One death occurred in each group, but a causal relationship to the contrast medium could not be established. It is concluded that nonionic contrast media significantly reduce the frequency of severe and potentially life-threatening ADRs to contrast media at all levels of risk and that use of these media represents the most effective means of increasing the safety of contrast media examinations.

Adolescent↗
PubMed1990

Osseous hemangioma arising in the facial bone.

Hemangiomas of bone are rare tumors in the facial region. In our own case, magnetic resonance imaging showed unique linear high-signal-intensity internal components in T1-weighted images. The histological study demonstrated that adipose tissue occurring in the stroma of the tumor caused the high signal intensity in T1-weighted images. We employed a vascularized calvarial bone flap to reconstruct the malar eminence after resection of the tumor.

Aged↗
PubMed1990

[Angiographic anatomy of arterial branches to the caudate lobe of the liver with special reference to its effect on transarterial embolization of hepatocellular carcinoma].

The arterial branches to the caudate lobe of the liver have been little studied angiographically, so it has been thought that the branches can be rarely recognized on the hepatic angiogram. We evaluated it with the stereo or stereo-magnification angiograms in 106 cases. They were identified in 90 cases (84.9%), one branch in 75 cases, two branches in 15 cases. The branches had a variable origin. In 50%, it originated from the right hepatic artery. In some cases, it came from both the right and left hepatic arteries. Recently we treated 10 cases of hepatocellular carcinoma in the caudate lobe with transcatheter arterial embolization (TAE), the results were poor in them except for one. We think that the proximal and variable origins of the caudate lobe arteries are the main cause of the poor effect of TAE.

Angiography↗
PubMed1990

[201T1 single photon emission computed tomography in the diagnosis of lung cancer].

201T1 SPECT was performed in 84 patients with suspected lung cancer. Both early and delayed scans demonstrated abnormal accumulation in 67 of 68 malignant pulmonary lesions and in nine of 18 benign conditions. All of 64 lung cancer were clearly visualized. Delayed ratio (uptake ratio of the lesion to the normal lung on delayed scan) and retention index (degree of retention in the lesion) were helpful to differentiate malignant from benign lesions. This method was also useful to evaluate mediastinal involvement from lung cancer.

Adenocarcinoma↗
PubMed1990

[A case of lung cancer suspected to be pulmonary mycosis of the fungus ball type].

This paper reports a 73-year-old male case of lung cancer presenting as thin-walled cavity which was suspected to be pulmonary mycosis of the fungus ball type. Routine chest X-ray film showed a thin-walled cavity without a round shadow inside it. CR tomogram taken 2 months after the previous plain chest X-ray film showed an irregular thickening of the cavity wall and a round shadow inside it. Pulmonary mycosis of the fungus ball type was suspected based on the CR tomogram. But chest X-ray CT film taken 1 month after the previous CR tomogram revealed that the entire cavity wall was thickened with irregular convexity and no round shadow was seen in the cavity. Cavitary lung cancer was also suspected based on the findings of X-ray CT film. The surgical specimen, obtained by right upper lobectomy, revealed a moderately differentiated squamous cell carcinoma unaccompanied by pulmonary mycosis in the cavity space. Even in cases suggestive of mycosis, aggressive surgical intervention is recommended in those suspected of malignancy.

Aged↗
PubMed1989

[Giant renal cell carcinoma: a case report].

Though renal cell carcinoma is a fairly common disease, it is extremely rare to encounter a case providing a resected mass as large as over 2,000 g in weight. We report a case in which a giant 2,200 g tumor was resected after renal arterial embolization and interferon treatment for reduction of its size. A forty-three-year-old woman was first seen at a certain hospital with a chief complaint of fever and right flank pain. Under suspicion of right renal tumor, nephrectomy by extraperitoneal flank incision was attempted. However, the tumor was too large to be resected. After transfer to our department, she was treated by renal arterial embolization with absolute ethanol and steel coil and by the administration of interferon (rIFN-alpha A). As the tumor shrank to 77% of its original size on CT measurements and became mobile, transperitoneal nephrectomy was performed. The resected mass was as large as 12 x 12 x 21 cm. Pathologically, it was a clear cell type tumor showing mucinous degeneration and hyaline degeneration of tumor cells. Interferon used amounted to as high as 864 x 10(6) units, but no particular side effect occurred. No recurrence has been detected so far.

Adult↗
PubMed1989

[Single exposure energy subtraction chest radiography--clinical survey on utility of bone image].

The authors undertook a clinical study to determine the values and limitations of soft tissue subtracted image by dual-energy digital radiography. 573 patients were examined by dual-energy subtraction with a single exposure using computed radiography. Soft tissue subtracted image were found informative in 37 patients (6.5%) compared with non-subtraction image. It provided useful information about demonstrating calcification in pulmonary nodules, assessing the presence or absence of rib lesions, and excluding the possibility of pulmonary nodules.

Humans↗
PubMed1989

Increased contact hypersensitivity response in mice by topical application of 1 alpha,25-dihydroxyvitamin D3 to elicitation site.

Recent evidence indicates that the biologically active metabolite of vitamin D3, 1 alpha,25-dihydroxyvitamin D3 [1 alpha,25(OH)2D3], has an effect on the regulation of the immune response. We investigated whether topical treatment of mice with 1 alpha,25(OH)2D3 influences the contact hypersensitivity (CHS) response to trinitrochlorobenzene (TNCB). 1 alpha,25(OH)2D3 was applied to the dorsal trunk of A/J mice on days 0-3, and on day 4 topical application of 5% TNCB on the 1 alpha,25(OH)2D3-treated site was performed. The mice were tested for CHS on day 10 by applying 1% TNCB to the ears. No effect on induction of CHS response to TNCB was observed in 1 alpha,25(OH)2D3-treated mice compared with 24,25-dihydroxyvitamin D3[24,25(OH)2D3]-treated mice as control. In a second experiment, the dorsal trunk of A/J mice was treated with 5% TNCB on day 0. The topical application of 1 alpha,25(OH)2D3 on the ears was performed from days 2 to 5. On day 6, the mice were tested for CHS by applying 1% TNCB to the 1 alpha,25(OH)2D3-treated ears. When 1 alpha,25(OH)2D3 was administered to the elicitation site prior to the challenge, pretreatment of mice with 1 alpha,25(OH)2D3 increased their response to TNCB by 40% compared with 24,25(OH)2D3-treated mice as control (P less than 0.01). There were no findings suggesting that the pretreatment of the challenge site with 1 alpha,25(OH)2D3 induced an irritant dermatitis that was superimposed on a subsequent CHS reaction. The 1 alpha,25(OH)2D3 modulation of CHS response to TNCB in mice suggests that the hormone may play a role in the regulation of the immune response in vivo.

Administration, Topical↗
PubMed1989

Intrahepatic periportal abnormal intensity on MR images: an indication of various hepatobiliary diseases.

The frequency and degree of intrahepatic periportal abnormal intensity (PAI) on magnetic resonance images in patients with or without various hepatobiliary and pancreatic diseases were analyzed. In 63 patients without hepatobiliary disease, except for a small metastatic liver tumor or cavernous hemangioma, no definite PAI was seen. Definite PAI was seen in all patients with obstructive jaundice, cholangitis, and cholangiocellular carcinoma. It was also clearly seen in all four cases of malignant lymphadenopathy in the hepatoduodenal ligament, in one of two cases of acute hepatitis, and in four of 47 cases of liver cirrhosis. However, in patients with bile duct dilatation or with gallstone or pancreatic disease without obstructive jaundice or cholangitis, no definite PAI was seen. Histologic studies of the liver performed in 23 patients with definite PAI showed edema, ductular proliferation, dilatation of lymph vessels, and inflammatory cell infiltration in portal tracts. It is concluded that definite intrahepatic PAI is a useful sign that indicates the presence of biliary or diffuse hepatic disease.

Adult↗
PubMed1989

Adenomatous hyperplastic nodules in the cirrhotic liver: differentiation from hepatocellular carcinoma with MR imaging.

Differentiation of hepatocellular carcinomas from adenomatous hyperplastic nodules (AHNs) is important for the early and precise detection of hepatocellular carcinoma in the cirrhotic liver. For this purpose, the authors compared findings on magnetic resonance (MR) images of surgically resected AHNs (n = 7) with those of hepatocellular carcinoma (n = 47). AHNs were divided into two histologic groups: those without atypia (n = 5) and those with atypical hepatocytes or malignant foci (n = 2). All AHNs without atypia were hyperintense on T1-weighted spin-echo images and hypointense on T2-weighted spin-echo images relative to the surrounding liver. However, almost all hepatocellular carcinomas, except for two lesions with massive coagulation necrosis, were demonstrated as hyperintense on T2-weighted images. MR imaging may be useful in the differentiation of AHN without atypia from hepatocellular carcinoma in the cirrhotic liver.

Carcinoma, Hepatocellular↗