Biomedical subjects

T Kasuga

Publications and source records attributed to T Kasuga.

At least 73 records · Page 4Linked to original sources

PubMed1992

Malignant melanomas of the oral cavity: heterogeneity of pathological and clinical features.

Data on 35 patients with oral malignant melanomas were pooled and the pathological features and the clinical course were examined in detail. Of these 35 cases, 27 (77.1%) showed a two-phase growth pattern, with both a vertical and a radial growth phase. Moreover, these 27 cases were classified into three subtypes according to gross features of the vertical growth phase; nodular, flat elevated and ulcerated types. Almost two-thirds of the cases were of the melanotic type. Malignant melanomas without a radial growth phase were found in 8 instances, all of which showed a nodular growth pattern, 1 being of melanotic type and 7 amelanotic. Mean latent insidious periods were evaluated for the cases with different growth phases. Cases with a radical growth phase exhibited the longest mean latent period (35.7 months), and a median survival time of 23.5 months. Cases without a radial growth phase showed a short mean latent period (2.1 months), and a median survival time of 7.5 months. The thickness of invasion ranged from 2 to 9 mm. Although 77.1% of the cases depicted similar pathological patterns to acral lentiginous melanomas of the skin, oral malignant melanomas demonstrated heterogeneity in morphological features, developmental process and biological behaviour. The histogenesis of oral melanomas is briefly discussed.

Adult↗

PubMed1992

Pathological features of the pulmonary artery in Takayasu arteritis.

Little attention has been paid to the pathological features of the pulmonary artery in Takayasu arteritis. Autopsy specimens of 6 cases of this disease were studied. Lesions were found in the aortic arch and its brachiocephalic branches in all cases and in both the aortic arch and thoracoabdominal aorta in 5 cases. The pathohistologic characters of the pulmonary artery were very similar to those of the systemic artery. Stenosis-recanalization, so-called blood vessels-in-blood vessels, of the pulmonary elastic arteries were found in four cases. These lesions were not observed in the systemic arteries, and most of the newly formed channels in them seemed to be branches of bronchial arteries. Luminal obstruction of pulmonary muscular arteries was observed in 4 cases, cellular arteritis of muscular arteries in 2 cases, and angiomatoid dilatation of small blood vessels in 2 cases. Thus in this study we found peculiar stenosis-recanalization lesions of the pulmonary elastic arteries, and also showed that the pulmonary elastic and muscular arteries are frequently involved in Takayasu arteritis. These findings suggest that pulmonary hypertension could influence morbidity and long-term mortality in this disease.

Adult↗

PubMed1992

Coronary artery lesions in Takayasu arteritis: pathological considerations.

This communication reviews the clinical and pathological features of coronary artery lesions in Takayasu arteritis. The incidence of coronary artery involvement has been reported to be 9% to 10%, and is observed mainly in autopsy cases because coronary artery disease is usually not evident until the occurrence of angina pectoris or myocardial infarction, or after the onset of congestive heart failure. On the basis of pathological features, the following three types of coronary artery lesions can be distinguished: type 1, stenosis or occlusion of the coronary ostia and the proximal segments of the coronary arteries; type 2, diffuse or focal coronary arteritis, which may extend diffusely to all epicardial branches or may involve focal segments, so-called skip lesions; and type 3, coronary aneurysm. Most of the coronary artery lesions in Takayasu arteritis are of type 1. Narrowing of the coronary arteries is mainly due to the extension of the inflammatory processes of proliferation of the intima and contraction of the fibrotic media and adventitia from the ascending aorta. In some cases, coronary stenosis may be caused by coronary arteritis as skip lesions in Takayasu arteritis, but even in these cases the lesions have been reported to affect mainly the proximal segments of the coronary arteries. Diffuse lesions of the coronary artery and coronary artery aneurysm seem to be very rare in Takayasu arteritis. Other causes of coronary ostial stenosis, coronary arteritis and coronary artery aneurysm are also discussed.

Adult↗

PubMed1992

A case of popliteal cystic degeneration with pathological considerations.

Adventitial cystic degeneration of the popliteal artery is seldom encountered; only 39 cases have been reported up to now in Japan. The pathogenesis of this disease remains controversial, and the authors describe a case in which the pathological findings differed from cases reported in the previous literature. The subject was a 74-year-old man admitted to our hospital complaining of intermittent claudication. The characteristic findings of cystic degeneration of the popliteal artery were uncovered by contrast-enhanced computed tomography (CT) and duplex sonography. The contrast-enhanced CT showed a low-density area and duplex sonography revealed a multi-lobulated low-echoic lesion. The Doppler signal of the low-echoic lesion could not be detected. While some cysts were found in the adventitia, they were mainly located in the media. The media also showed a remarkable decrease of smooth muscle cells and a prominent mucinous degeneration that had occurred circumferentially. These findings suggest that the medial degeneration noted had occurred prior to cystic formation. Because of this and other findings, we recommend the use of the term cystic degeneration of the popliteal artery in addition to the term cystic adventitial disease of the popliteal artery.

Aged↗

PubMed1992

Wegener's granulomatosis. Associated with diffuse pulmonary hemorrhage.

The authors report a case of Wegener's granulomatosis with the unusual manifestation of diffuse pulmonary hemorrhage. A 58-year-old man complained of bloody sputum and fever. Chest X-ray films showed multiple nodular shadows in both lung fields. He was diagnosed as having Wegener's granulomatosis by transbronchial lung biopsy, which revealed necrotizing granulomatous inflammation with necrotizing vasculitis. Despite treatment with cyclophosphamide and prednisolone, his condition rapidly deteriorated. An extensive diffuse alveolar shadow appeared in both lung fields in chest X-ray films, anemia became worse, and he died of respiratory failure. Autopsy revealed diffuse alveolar hemorrhage with necrotizing capillaritis in addition to the typical pathological findings in Wegener's granulomatosis. The capillaritis was characterized by neutrophilic infiltration of alveolar septa, and fibrin thrombi in alveolar capillaries. Diffuse pulmonary hemorrhage is uncommon in Wegener's granulomatosis. However, once diffuse pulmonary hemorrhage occurs, the respiratory condition rapidly deteriorates and is life-threatening. Therefore, accurate diagnosis and appropriate treatment are required.

Granulomatosis with Polyangiitis↗

PubMed1992

Tumor-promoting effects of both iodine deficiency and iodine excess in the rat thyroid.

Thyroid tumor-promoting effects of iodine deficiency and iodine excess were investigated in a rodent 2-stage model to estimate an optimal iodine intake range that would not effectively promote development of thyroid neoplasia. Six-week-old male F344 rats were given a single subcutaneous injection of 2,800 mg/kg body weight N-bis(2-hydroxypropyl)-nitrosamine (DHPN) or saline vehicle, maintained on Remington's iodine-deficient diet (21 +/- 2 ng/g iodide), and supplemented with various amounts of potassium iodide up to 260 mg/liter in drinking water to generate conditions ranging from severe iodine deficiency to severe iodine excess. In DHPN-treated rats, both conditions significantly increased thyroid follicular tumorigenesis. In DHPN-untreated rats, iodine deficiency produced diffuse thyroid hyperplasia, characterized by small follicles with tall epithelium and reduced colloid, together with a decrease in thyroxine (T4) and an increase in thyroid-stimulating hormone (TSH). On the other hand, iodine excess produced colloid goiter, characterized by large follicles with flat epithelium and abundant colloid admixed with normal or small-sized follicles lined by epithelium of normal height, together with normal serum T4 and slightly decreased TSH. These effects were directly proportional to the severity of iodine deficiency or extent of iodine excess and suggest that each condition has a different thyroid tumor promotion mechanism. Iodine intakes that showed the least tumor promotion were 2.6 and 9.7 micrograms/rat/day in this study. Promoting mechanisms and the problem of statistically estimating recommended daily iodine intake range are briefly discussed.

Animals↗

PubMed1992

[Serum 7S collagen levels in diffuse interstitial lung diseases--an index of the destruction of alveolar structure].

To examine whether alteration of 7S collagen in the alveolar basement membrane is related to the condition and prognosis of diffuse interstitial lung diseases (idiopathic interstitial pneumonia: IIP, collagen vascular diseases, sarcoidosis, and hypersensitivity pneumonitis), we measured serum 7S collagen levels in 123 patients with diffuse interstitial lung disease and other lung diseases. Patients with diffuse lung diseases (diffuse interstitial lung disease, pulmonary emphysema, and diffuse panbronchiolitis: DPB) showed significantly higher serum levels of 7S collagen than healthy normal controls. Serum 7S collagen levels in IIP and collagen vascular diseases were significantly higher than those in pulmonary emphysema and DPB. In cases of IIP, serum 7S collagen levels in the active stage were significantly higher than those in the inactive stage. Furthermore, the prognosis of patients with higher serum 7S collagen levels was significantly poorer than those of patients with lower serum 7S collagen levels. In infectious pulmonary diseases, serum 7S collagen levels of patients with adult respiratory distress syndrome (ARDS) were significantly higher than those of patients without ARDS. Autopsy specimens obtained from patients with positive serum 7S collagen showed diffuse alveolar damage and/or diffuse pulmonary hemorrhage in the alveolar areas. Immunohistochemical staining for 7S collagen showed disruption and/or loss of the alveolar basement membrane. The authors conclude that serum level of 7S collagen is useful for estimating the activity of diffuse interstitial lung diseases as an index of the destruction of alveolar structure.

Basement Membrane↗

PubMed1992

[A new polar map to quantify reversible area by myocardial 201Tl single photon emission computed tomography and clinical application to patients before and after percutaneous transluminal coronary angioplasty].

In the studies of stress 201Tl single photon emission computed tomography, we have developed a computer method to discriminate reversible from irreversible defect, then quantify each area and display the area on the polar map. Initial percent uptake (%Ui) and delayed percent uptake (%Ud) were expressed as percent of the maximum uptake area and were defined as regional myocardial 201Tl uptake in initial and delayed image, respectively. The %Ud/%Ui ratio was defined as redistribution ratio (RD-ratio). The values of %Ui obtained from each pixel of short axis slices were plotted against the values of RD-ratio on XY co-ordinates. In this graphic display, normal area, ischemic viable area and non viable area were separated by the following four lines. A; The straight line (Y = 2.0-0.012X) indicating the relationship between %Ui and RD-ratio for the group with ischemic viable myocardium. B; The parallel line to A and shifted to -1.5 SD from A. C; The vertical line at 67.0% level (ischemic upper level). D; The vertical line at 27.6% level (viable lower level). Each area was discriminated by color display and calculated relative area values were displayed on the polar map. Criteria for discriminating each area were derived from the results of ischemic pre-transluminal coronary angioplasty (PTCA) lesions (n = 21) in which viability was confirmed by successful PTCA and previous results of 66 cases with single vessel disease and 16 cases of control group. This new computerized technique was applied for evaluation of another group with successful PTCA (n = 15).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

[Experimental study on catheter-bypass between superior mesenteric and hepatic hilar portal veins (SMV-HPV bypass)].

Hepatic ischemia is a consequence of concomitant resection of the portal vein and the hepatic artery when it is necessitated in hepatobiliary or pancreatic surgery. We developed an antithrombogenic catheter with a balloon and experimentally evaluated the safety of construction of SMV-HPV bypass using this catheter to simultaneously prevent intestinal vascular congestion and hepatic ischemia. The main portal vein and the hepatic artery were blocked and SMV-HPV shunting was made in five dogs (bypass group); the main portal vein and the hepatic artery were blocked and the SMV was shunted to the femoral vein in others (ischemia group). In the ischemia group, 3 of the 5 dogs died within 5 days, but all animals of the bypass group survived for a long period. In the bypass group, the changes of adenine nucleotide levels, energy charge ratio, liver function, blood coagulation, and fibrinolysis were mild and within physiologic ranges, and none of changes of the hepatic tissue were observed histologically. This bypass procedure is simple and safe to simultaneously prevent hepatic ischemia and intestinal vascular congestion in cases requiring concomitant resection and reconstruction of the portal vein and the hepatic artery.

Animals↗

PubMed1992

Cytogenetic studies of human malignant melanoma cell lines.

Cytogenetic studies were performed on six cell lines derived from three patients suffering from malignant melanomas. The modal chromosome numbers were in the hypotriploid to hypertetraploid ranges and both the numerical and structural aberrations of chromosomes were found. Aberrations were most frequently observed in chromosomes 1, 6 and 7. Deletion of 1q was consistently present in all cell lines, while loss of 6q was observed in two cell lines of case 1. Translocations t (Y; 6) and t (6;?) occurred in one cell line from case 3. An increased number of copies of chromosome 7 was a characteristic feature of the cell lines from case 2. Since positive correlation between the expression of EGF receptors and an increased dosage of chromosome 7 has been reported for malignant melanomas and the gene for EGFR has been mapped to band 7p12-p13, this phenomenon might be of importance for the proliferation of malignant melanoma. The findings of the present study are generally in agreement with the data previously published in the literature, indicating the existence of specific non-random chromosome lesions during melanoma development.

Adult↗

PubMed1991

[Noninvasive quantitative measurement of cerebral blood flow with 123I-IMP--a study concerning the input function].

For the noninvasive quantitative measurement of cerebral blood flow (CBF) using N-isopropyl-[123I]p-iodoamphetamine (IMP), we studied the usefulness of the lung clearance curve obtained by a single probe detector as the input function for brain as an alternative to arterial blood activity. In four patients, we compared the time-activity curve of the lung and serial arterial blood activity for approximately 20 minutes following an IV bolus injection of IMP. Significant positive correlations were observed between lung clearance and the integral of arterial blood activity of IMP. In addition, a study to identify the best region for monitoring lung activity with the probe detector was performed in six patients using a gamma camera and region of interest (ROI) management. The central region of the right lung was found to be the best position for monitoring lung radioactivity. This study suggests that the lung clearance curve of IMP can be used as the input function for brain in the quantitative assessment of CBF.

Amphetamines↗

PubMed1991

[MR evaluation of wallerian degeneration of the pyramidal tract].

This study is based on 135 magnetic resonance (MR) exams of 110 patients with wallerian degeneration of the pyramidal tract shown on MR images acquired on a mid field imaging scanner. The MR findings of wallerian degeneration were abnormal signal band along the course of the pyramidal tract and ipsilateral brain stem shrinkage. In all 110 cases an abnormal signal band was seen on T2-weighted spin-echo images, that is, a hypointense band in four exams between 30 days and 116 days after onset of symptoms, and hyperintense bands in 122 exams. The hyperintense signal on T2-weighted images was shown in most cases after 200 days from the onset. In one case a signal of the pyramidal tract showed a hyperintense band at 7 days, hypointense at 30 days, and hyperintense again at 123 days after onset. Sequential MR exams of another case showed gradual narrowing of the hyperintense signal band and progression of the ipsilateral brainstem shrinkage. The narrowing of the pyramidal tract and the ipsilateral brain stem shrinkage tended to be shown after 6 months from onset.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1991

Early lesion of N-nitroso-N-ethylurea-induced hamster neurofibromatosis model.

To investigate histogenesis of neurofibroma, early lesions of N-nitroso-N-ethylurea-induced neurofibroma of Syrian golden hamsters were examined. The lesions were detectable from 8 weeks of age, and a total of 14 lesions in 9 hamsters from 8 to 12 weeks of age were observed. Most of the lesions were found in the skin; they were also observed in the trigeminal nerve, cervical plexus, and abdominal sympathetic ganglion. Histological examination revealed there were two types of early lesions such as solitary and plexiform types. The former developed in the s.c. or dermal part of the skin and showed invasive growth of the surrounding tissue, while the latter originated from the large nerves such as the trigeminal nerve or cervical plexus. Growth kinetics of the early lesions was quantitated by continuous administration of bromodeoxyuridine and double immunostaining. Using these systems we observed that various kinds of cells had already participated in early lesions and later Schwann cells became a main component of the tumor. The histogenesis of neurofibroma was considered to be complexed by proliferation of several kinds of cell types at the early stage.

Animals↗

PubMed1991

Ultrasonographic appearance of dermoid and epidermoid cysts in the head and neck.

The ultrasonographic features of 6 histologically proven dermoid and epidermoid cysts in the head and neck are reported. All 6 cysts had internal echoes, with a solid appearance. Five of the 6 were echogenic, with only slight or no posterior echo enhancement. Amorphous keratinous debris from keratinizing stratified squamous epithelium filled the lumen of each cyst, producing the internal echoes. Most of the true solid tumors examined were generally of lower echogenicity, and could be differentiated from dermoid and epidermoid cysts ultrasonographically, although lipomas were indistinguishable from these cysts.

Adult↗

PubMed1991

Foci of stromal melanocytes (so-called blue naevus) of the uterine cervix in Japanese women.

Foci of stromal melanocytes (FSM) of the uterine cervix have been known as extra-cutaneous "blue naevus". However macroscopic and histological findings suggest that FSM of the cervix are analogous to dermal melanocytosis, rather than to cutaneous blue naevus and the lesions are more appropriately called stromal melanocytosis. FSM of the cervix have been considered rare, but our study showed that they are not uncommon in Japanese women occurring in 8.6% (42/486). The lesions were initially observed in the third decade of life and became most prevalent in the fifth decade (15/86 cases, 17.4%). In stroma of the cervix, stromal melanocytes (SM) were present where many peripheral nerve fibres were seen. SM of the cervix were positive for S-100 protein in immunohistochemical studies and were sometimes observed close to peripheral nerve fibres. Melanocytes were never observed in the ectocervical and endocervical epithelium, but only in the stroma of the cervix. We suggest that malignant melanoma of the uterine cervix may originate from SM.

Adolescent↗

PubMed1991

The killing effect of 4-S-cysteaminylphenol, a newly synthesised melanin precursor, on B16 melanoma cell lines.

We have examined the killing effect of 4-S-cysteaminylphenol (4-S-CAP), a newly synthesised melanin precursor, on B16 melanoma cell lines possessing different melanin-producing activities and found it to be particularly effective in heavily melanised melanoma cells, but less so in moderately melanised melanoma cells, and having no effect on amelanotic melanoma cells and nonmelanoma cells. Thus, it was found that the killing effect of 4-S-CAP is highly dependent upon the synthesis of melanin and tyrosinase in melanoma cells, suggesting that 4-S-CAP may become toxic to melanoma cells only after oxidation by tyrosinase. The killing activity of 4-S-CAP also was found to be associated with a profound inhibition of the thymidine incorporation in pigmented melanoma cells, as compared to the uridine and leucine incorporation. Further, the inhibition of DNA synthesis was most pronounced in heavily melanised melanoma cells, less so in moderately melanised melanoma cells, and not seen in amelanotic melanoma cells. As a possible mechanism that might account for this action, it may be that 4-S-CAP is oxidised by tyrosinase to the o-quinone form via the catechol derivative and that some of the quinones then conjugate with sulfhydryl enzymes including DNA polymerase, thus exerting a killing activity for pigmented melanoma cells. Thus, 4-S-CAP appears to provide a new, effective cytotoxic agent for rational chemotherapy of malignant melanomas.

Animals↗

PubMed1991

Neoplastic argentaffin cells with intracytoplasmic eosinophilic granules in a gastric adenocarcinoma.

A case of poorly differentiated adenocarcinoma of the stomach with unique histological features is reported: in addition to characteristic adenocarcinoma cells, a large number of tumor cells contained bright eosinophilic and argentaffin granules in their cytoplasm. On routine histologic examination, the latter cells closely resembled the endocrine cells present in the normal human gastrointestinal tract, although the granules were distributed throughout the cytoplasm and did not show any polarity, which is usually subnuclear in normal endocrine cells. Immunohistochemical studies demonstrated positive staining for lysozyme, CEA, gastrin and HCG. Electron microscopic examination revealed cytoplasmic neurosecretory granules, and some tumor cells were found to contain both secretory granules and mucinous material within the same cytoplasm. These neoplastic endocrine cells presumably originated from primitive digestive system elements capable of differentiating towards both endocrine and mucus-secreting varieties.

Adenocarcinoma↗

PubMed1991

Stromal melanocytic foci ("blue nevus") in step sections of the uterine cervix.

Stromal melanocytic foci (SMF) of the uterine cervix, which are known as extracutaneous blue nevus, were examined in step sections of the cervix. A total of 189 uterine specimens surgically excised for leiomyoma, adenomyosis etc., were studied. The over-all incidence of SMF of the cervix was 28.6% (54/189 cases). The incidence of these lesions increased with age, and they were most prevalent in the sixth decade of life (12/30 cases, 40%). SMF were presented more often in the anterior wall than in the posterior wall. Most of the lesions were less than 1 mm in size. No case of SMF demonstrated expansive tumorous growth. Six of 54 cases of SMF displayed consecutive spread of SMF in almost all step sections of the cervix. The histological findings confirmed that SMF of the cervix is quite common existence among Japanese women. It is speculated that the mucosal region near the skin and/or cutaneous region near the mucosa may have stromal melanocytosis; malignant melanoma could develop from SMF of the cervix, which did not have junctional activity because of stromal melanocytic origin.

Adult↗