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Biomedical subjects

S Soimakallio

Publications and source records attributed to S Soimakallio.

105 records · Page 6Linked to original sources
PubMed1980

Polymerised autologous tumor tissue particles in experimental cancer immunotherapy with special reference to the effects on the immune system of the host.

The efficacy of the specific active cancer immunotherapy utilizing autologous tumor tissue particles polymerised with ethylchlorformiate, and used in combination with the PPD tuberculin adjuvant, was studied in the mastocytoma (P-815 X2)-DBA/2 mouse system. Special attention was focused on the effects of the therapy on the immune system of the host as evaluated on the basis of the spleen white pulp morphology. The signs of tumor rejection by the host (tumor-surrounding fibrous scar, lymphocyte and plasma cell infiltrations, and disappearance of the tumor tissue) were most marked in mice receiving the specific immunotherapy. The specific cancer immunotherapy instituted was capable of reverting to a considerable degree the profound depletion of the T- and B-lymphocyte populations found in the spleen white pulp of mice not receiving any therapy for their tumor. Conclusion was drawn that the favorable influence on the tumor rejection exerted by the specific immunotherapy tested, most probably is attributable to its stimulatory effects on the cells responsible for both the cell-mediated and humoral immune reactions, the appropriate co-operation of both of which is needed to ensure the most effective host response against the tumor cells.

Animals↗
PubMedDate not supplied

Quantification of metabolites from single-voxel in vivo 1H NMR data of normal human brain by means of time-domain data analysis.

We present here a combination of time-domain signal analysis procedures for quantification of human brain in vivo 1H NMR spectroscopy (MRS) data. The method is based on a separate removal of a residual water resonance followed by a frequency-selective time-domain line-shape fitting analysis of metabolite signals. Calculation of absolute metabolite concentrations was based on the internal water concentration as a reference. The estimated average metabolite concentrations acquired from six regions of normal human brain with a single-voxel spin-echo technique for the N-acetylaspartate, creatine, and choline-containing compounds were 11.4 +/- 1.0, 6.5 +/- 0.5, and 1.7 +/- 0.2 mumol kg-1 wet weight, respectively. The time-domain analyses of in vivo 1H MRS data from different brain regions with their specific characteristics demonstrate a case in which the use of frequency-domain methods pose serious difficulties.

Aspartic Acid↗
PubMedDate not supplied

A primary carcinoid tumor of the kidney: a case report and review of the literature.

BACKGROUND: Primary carcinoids are found mostly in the gastrointestinal tract. Primary carcinoid tumor of the kidney is rare; only 28 patients have been reported. Because of the rarity of the lesion, its radiological and clinicopathological features are not well characterized. At the same time, its prognosis and histogenesis is unknown. METHODS: A 62-year-old patient presented with a carcinoid tumor on the isthmus of the horseshoe kidney. Radiological, clinicopathological, and immunohistochemical tests were performed. The tumor was resected. RESULTS: Two years later, metastasis were observed in the liver. The metastasis were treated with percutaneous ethanol sclerotherapy (PET). CONCLUSIONS: To our knowledge, this is the first case of primary renal carcinoid tumor present on the isthmus of the horseshoe kidney and the first case of carcinoid liver metastasis to be treated with PET.

Angiography↗
PubMedDate not supplied

Intraperitoneal seeding from hepatocellular carcinoma following percutaneous ethanol ablation therapy.

We present a case of intraperitoneal seeding in a 36-year-old woman with a large primary hepatocellular carcinoma located superfically in the left lobe of the otherwise normal liver. The patient was treated with percutaneous ethanol ablation therapy. Eight months after the treatment computed tomography and ultrasonography (US) revealed an intraperitoneal seeding that was confirmed with US-guided percutaneous biopsy.

Adult↗
PubMedDate not supplied

Percutaneous endovascular stenting: development, investigation and application.

Percutaneous endovascular stenting (PES), a new and alternative approach of interventional radiologic techniques, has encouraging potentials for management of vascular obstructive diseases. The most important role of PES is to prevent the risk of abrupt closure and to reduce the rate of early and late post-angioplasty restenosis (PARS) of PTA. Because of different working mechanisms, various stents show different advantages and disadvantages. Specific indications of PES are: (1) further compensation for failed PTA, (2) management of complications due to PTA and (3) primary treatment of vascular obstructive diseases. Based on a preliminary comparison with atherectomy, laser angioplasty and PTA, PES seems to provide an advantage for long-term patency of large caliber vessels such as iliac arteries, while more significant problems still exist in PES with small caliber vessels such as femoral-popliteal and coronary arteries. Further comparative clinical research is required to establish the utility of PES among other intraluminal techniques of vascular interventions.

Animals↗
PubMedDate not supplied

Image processing in digital chest radiography: effect on diagnostic efficacy.

The usefulness of digital image processing of chest radiographs was evaluated in a clinical study. In 54 patients, chest radiographs in the posteroanterior projection were obtained by both 14 inch digital image intensifier equipment and the conventional screen-film technique. The digital radiographs (512 x 512 image format) viewed on a 625 line monitor were processed in three different ways: (1) standard display; (2) digital edge enhancement for the standard display; and (3) inverse intensity display. The radiographs were interpreted independently by three radiologists. The diagnoses were confirmed by CT, follow-up radiographs and clinical records. Chest abnormalities of the films analyzed included 21 primary lung tumors, 44 pulmonary nodules, 16 cases with mediastinal disease and 17 cases with pneumonia/atelectasis. Interstitial lung disease, pleural plaques, and pulmonary emphysema were found in 30, 18 and 19 cases, respectively. The sensitivity of conventional radiography when averaged overall findings was better than that of the digital techniques (P less than 0.001). The differences in diagnostic accuracy measured by sensitivity and specificity between the three digital display modes were small. Standard image display showed better sensitivity for pulmonary nodules (0.74 vs 0.66; P less than 0.05) but poorer specificity for pulmonary emphysema (0.85 vs. 0.93; P less than 0.05) compared with inverse intensity display. We conclude that when using 512 x 512 image format, the routine use of digital edge enhancement and tone reversal at digital chest radiographs is not warranted.

Adolescent↗
PubMedDate not supplied

Dynamic contrast enhancement of the upper abdomen: effect of contrast medium and body weight.

Contrast enhancement (CE) of the aorta, liver, and spleen was studied in dynamic body computed tomography (CT) in 71 patients. Four contrast media (CM) (diatrizoate, ioxithalamate, ioxaglate, iopamidol) were injected intravenously in equal bolus doses of 18.5 g iodine. Iopamidol produced the highest average peak and 2-minute aortic CE, significantly different from ioxithalamate (P less than 0.001), diatrizoate (P less than 0.01), and ioxaglate (P less than 0.0125) at peak levels. Two-minute CE values of the aorta were highest with iopamidol as were peak and 2 minute CE of the liver and spleen. A linear, inverse relationship between body weight and CE was present both at peak CE and after 2 minutes in all tissues. The nonionic CM appear to have best dose efficiency in the vascular phase of dynamic CT. These results are also applicable to digital angiography. Differences in the CE of parenchymal organs with different CM are so small that they are unlikely to have clinical significance.

Aortography↗
PubMedDate not supplied

Quantitative metabolite patterns of human brain tumors: detection by 1H NMR spectroscopy in vivo and in vitro.

OBJECTIVE: The aim of the present study was to investigate quantitative metabolite patterns in human brain tumors by 1H nuclear MR spectroscopy (1H MRS). MATERIALS AND METHODS: Single voxel 1H MRS was used in studying metabolites in 23 primary brain tumors in vivo. The T2 relaxation times and saturation factors were determined for N-acetylaspartate (NAA), total creatine (Cr), choline-containing compounds (Cho), and water, which was used as an internal standard in computations of metabolite concentrations in vivo. Metabolites in biopsy specimens from 75 tumors were quantified by means of 1H MRS in vitro. RESULTS: The NAA concentrations were lower in brain tumors than in normal tissue in vitro and in vivo, irrespective of the histological type. The NAA was some threefold higher in vivo than in vitro, which could be due to partial volume effect and/or contributions from other metabolites to the peak at 2.02 ppm in vivo. Ratios of Cho to Cr concentrations were elevated in tumors relative to normal brain in vivo. Absolute Cho was some 50% higher in both benign astrocytomas and oligodendrogliomas in vivo than in normal brain. However, Cho concentration in vitro was significantly higher only in pituitary adenomas than in healthy white matter. Total creatine was approximately 50% lower in malignant astrocytomas and meningiomas than in normal brain. CONCLUSION: It is concluded that absolute concentrations of metabolites in vivo yield a different picture of tumor metabolites than that derived from uncorrected metabolite ratios.

Adenoma↗
PubMedDate not supplied

Assessment of renal artery stenosis with CT angiography: usefulness of multiplanar reformation, quantitative stenosis measurements, and densitometric analysis of renal parenchymal enhancement as adjuncts to MIP film reading.

PURPOSE: Our goal was to evaluate CT angiography (CTA) in diagnosing renal artery stenosis (RAS). METHOD: Thirty-seven patients underwent digital subtraction angiography (DSA) and CTA. Visual interpretation and stenosis measurements were made from maximum intensity projection (MIP) and multiplanar reformation (MPR) laser film prints of 78 renal arteries. RESULTS: Visual reading of MIP films showed good diagnostic performance by receiver operating characteristic curve analysis, with 100% sensitivity in the assessment of > or = 50% RAS but only 42-54% specificity (overall accuracy 60-75%). The false-positive rate decreased when MIP and MPR films were read together, but the excess of false negatives among the calcified lesions disabled this diagnostic algorithm. Combining visual interpretation of MIP films with quantitative measurements yielded the best diagnostic performance: 92% sensitivity, 80% specificity, and 84% overall accuracy. Renal cortical enhancement measurements (26 patients) had 81% overall accuracy. CONCLUSION: The overall accuracy of CTA with MIP film reading can be enhanced by quantitative measurement of stenosis or reviewing MPRs.

Adult↗
PubMedDate not supplied

Large-screen image intensifier photofluorography compared with full-size screen-film technique in chest radiography.

Large-screen image intensifier photofluorography revealed a radiation dose and exposure time of about one third of those of a medium speed rare-earth screen/film (Trimax T4/XD) combination for full-size chest radiography. The resolving power of the former technique is somewhat poorer and there is a moderate electron-òptical distortion in the peripheral field. In clinical chest radiography photospot films showed excellent demonstration of the central areas of the image but slight deterioration in peripheral parts. The minification effect of the photofluorographic films is advantageous for visual perception of many anatomic details on chest radiographs. The type of viewing device for photospot films is important.

Aged↗
PubMedDate not supplied

Large-image intensifier photofluorography and conventional radiography in pulmonary emphysema. Correlation with computed tomography.

Large-screen image intensifier (II) photofluorography was compared with full-size screen-film chest radiography in the diagnosis of pulmonary emphysema in 84 patients. Photospot films and conventional radiographs were interpreted independently by three radiologists. Computed tomography (CT) was used as an independent reference technique, and diagnostic performance of chest radiography in various CT patterns of emphysema was evaluated. The difference in diagnostic sensitivity for emphysema in favor of conventional chest radiography over photofluorography (0.65 versus 0.56) was statistically significant (p less than 0.05). Specificity of the imaging modalities was equal: 0.78 in full-size films and 0.77 in photospot films. All CT patterns of emphysema had great false negative response rates in chest radiography, which is an inaccurate technique for the diagnosis of emphysema. CT is required for reliable radiologic evaluation of emphysema.

Emphysema↗