Prevention of Restenosis after Coronary Angioplasty with Low-Density Lipoprotein Apheresis

Abstract: A prospective study was performed to determine whether low-density lipoprotein (LDL) apheresis, when performed only immediately before and after percutaneous transluminal coronary angioplasty (PTCA), is effective in preventing restenosis of coronary artery lesions following PTCA. Thirty-six patients with coronary heart disease (CHD) and hypercholesterolemia were divided into 2 groups. The 9 patients in the LDL group underwent LDL-apheresis 1 day before and 5 days after PTCA while the 27 patients of the control group underwent PTCA but did not undergo LDL-apheresis. Follow-up coronary angiography (CAG) was performed 4 months after PTCA. The rate of restenosis of coronary artery lesions was significantly lower in the LDL group (0%) than in the control group (30%). These findings suggest that LDL-apheresis, when performed before and after PTCA, is effective in preventing restenosis of coronary artery lesions in patients with CHD and hypercholesterolemia.     

Intraluminal thrombosis and growth-mechanism of giant intracranial aneurysms

12 giant intracranial aneurysms were studied by MRI. Intraluminal thrombosis was observed in 9 aneurysms. Thrombosis was found more frequently in larger aneurysms. Thrombi were formed posteriorly or inferiorly in the lumen of 4 among 5 IC-cavernous aneurysms. Location of the neck of the aneurysms and stagnation of blood flow influenced by gravity may be causative factors determining the location of thrombi. In 6 aneurysms intraluminal thrombi were inhomogeneous on MRI, suggesting that the thrombi had been formed at different times. New thrombi were formed between the aneurysmal wall and the old thrombus in 3 cases. Dissection of the aneurysmal wall by residual blood flow in the lumen or hemorrhage in the aneurysmal wall may be one of the growth mechanisms of giant intracranial aneurysms.     

Characteristics of rhabdomyosarcoma cell lines derived from uterine carcinosarcomas

 Rhabdomyosarcoma (RMS) is occasionally found in the female genital tract, and mostly appears as one of the heterologous mesenchymal components in uterine carcinosarcoma designated as malignant mixed müllerian tumour (MMMT). We examined the biological properties of a pure rhabdomyosarcoma (RMS) cell line designated FU-MMT-3, which was newly established from a surgical specimen taken from a patient with uterine MMMT. We also evaluated c-myc and MYCN gene amplification in three RMS cell lines (including FU-MMT-3) derived from three MMMTs by Southern blot analysis. FU-MMT-3 cells were propagated continuously for 57 serial passages over a 2-year period in vitro. FU-MMT-3 was able to produce tumours demonstrating pure RMS in athymic nude mice. Cytogenetically, FU-MMT-3 showed a triploidy pattern, with complex karyotypic abnormalities including trisomy of chromosome 8. All three RMS cell lines, including FU-MMT-3, showed amplification of the c-myc gene (approximately fourfold to eightfold), while no cell lines demonstrated MYCN gene amplification. FU-MMT-3 is considered to provide a useful system for the study of the biological behaviour of RMS in MMMTs. Extra copies of chromosome 8 and c-myc gene amplification may be associated with the rhabdomyoblastic differentiation in MMMT. Received: 7 January 1997 / Accepted: 2 May 1997     

Neurogenic bladder after operation of rectal cancer

Of the patients who had had a urodynamic examination during the five year period from 1982 to 1987 in our clinic, 48 patients underwent operations for rectal cancer prior to the study. In 35 of them, the operation mode was known. If the pelvic nerve is damaged by operative modes for rectal cancer, urinary disturbances of severe kinds may occur. In spite of such disturbances, 71.4% of those who had had excision of the low anterior part and 51.9% of those with Miles' operation could be weaned from the clean intermittent self-catheterization and take up spontaneous urination. Even in patients who developed severe dysuria, if catheterized at an early stage, many of them could urinate by abdominal pressure with in several months after operation, without the aid of a catheter. This transition took place mostly within one year after operation. When a patient develops dysuria after radical surgery for rectum cancer, treatment mainly with self-catheterization is an effective method at present.     

Interstitial deletion of the short arm of chromosome 6 as a new cytogenetic marker of T-cell lymphoma

Three patients with malignant lymphoma, two of T-cell type and the other probably also of T-cell type, had an interstitial deletion of the short arm of chromosome 6, del (6)(p21p23), in common in their lymphoma cells. These findings suggest that this new type of chromosome deletion may be a specific marker for T-cell lymphoma and may play an important role in the lymphomagenesis and the expression of the T-cell phenotype.     

Modifying Effects of Various Chemicals on Preneoplastic and Neoplastic Lesion Development in a Wide-spectrum Organ Carcinogenesis Model Using F344 Rats

Modifying potentials of various chemicals on tumor development were investigated in a wide-spectrum organ carcinogenesis model using male F344/DuCrj rats. The animals were treated with N-nitroso-diethylamine (100 mg/kg body weight, ip, single injection at the commencement of the study), N-methyl-N-nitrosourea (20 mg/kg body weight, ip, 4 times during weeks 1 and 2) and N-bis(2-hydroxypropyl)nitrosamine (0.1% in drinking water, during weeks 3 and 4) for multi-organ initiation and then were given one of 14 test chemicals including 6 hepatocarcinogens, 7 non-hepatocarcinogens and 1 non-carcinogen, or basal diet for 16 weeks. All rats were killed at the end of week 20, and the major organs were carefully examined for preneoplastic and neoplastic lesions. Immunohistochemical demonstration of glutathione S -transferase-positivc foci was also used for quantitative assessment of liver preneoplastic lesion development. Modifying effects were shown for 11 out of 14 test agents in the liver, forestomach, glandular stomach, lung, urinary bladder or thyroid, 7 of them targeting more than two organs. This was the first demonstration to our knowledge that cloflbrate possesses enhancing potential for urinary bladder carcinogenesis and an inhibiting effect on thyroid carcinogenesis. Caprolactam showed no effect in any organ, in agreement with its established inactivity. The results indicated that the system could be reliably applied as a medium-term multiple organ bioassay for assessment of the modification potential of test agents in unknown target sites.     

Ferritin immunohistochemistry as a marker for microglia

Summary An immunohistochemical analysis of formalin-fixed, paraffin-embedded brain sections was performed with antisera against holoferritin and the light(L)-subunit of ferritin. Sections immunostained using anti-glial fibrillary acidic protein (GFAP), Ricinus communis agglutinin-1 (RCA-1) stain for microglia and iron stain (Berlin blue stain) were compared. The L-subunit of ferritin was purified from normal human spleen according to the modified scrapie-associated fibrils purification, and the antiserum was raised in a rabbit. Both ferritin antisera positively stained resting and, more markedly, reactive microglia, both of which were also stained with RCA-1 but not with GFAP. Ferritin-positive resting microglia were seen more abundantly in cerebral and cerebellar cortices than in white matter. The advantages of ferritin antisera over RCA-1 are as follows. (1) RCA-1 heavily stains blood vessels, while anti-ferritin does not, hence the microglial cells are more readily visualized with ferritin immunohistochemistry. (2) Reactive microglia and macrophages are more strongly stained with anti-ferritin. (3) The staining intensity of ferritin is independent of the length of tissue fixation in formalin. However, anti-ferritin is inferior to RCA-1 in staining resting microglia with a scanty cytoplasm, especially in the white matter, probably because the former recognizes cytoplasmic components, while the latter recognizes cell membrane. Iron stain only gave a reaction to microglial cells in brains with neurosyphilis and to hemosiderin-laden macrophages. Thus, in addition to RCA-1, ferritin antisera are useful as a microglia marker in formalin-fixed, paraffin-embedded sections.Supported in part by Dr. A. Kondo, Department of Neuropathology, Neurological Institute, Kyushu University     

TECHNIQUES AND PITFALLS OF ENDOSCOPIC SUBMUCOSAL DISSECTION FOR COLORECTAL TUMORS

Endoscopic submucosal dissection (ESD) for colorectal tumors is steadily being developed. Safety and standardization of ESD for colorectal tumors have not been yet established because of the technical difficulties and the unsuitable anatomical characteristics of the colon and rectum. The authors mainly use a Flex knife for mucosal incision and a Hook knife for submucosal dissection to perform ESD safely. Skillful colonoscopic control, selection of scope, distal attachment tip hood, adequate high‐frequency generator and correct approach strategy should all be considered for safe performance of ESD. However, the incidence of indicative lesions is rare because the majority of colorectal tumors are adenomatous large laterally spreading tumors, which can be cured by intentional endoscopic piecemeal resection. At present, ESD for colorectal tumors should be performed only at central facilities that have expert colonoscopists. With the development of new devices and associated techniques, technical standardization of ESD for colorectal tumors is expected in the near future.