Influence of implantation site on growth, antigen expression and metastatic potential of human colonic cancer HT29 and 5583 xenografts in nude mice

In order to study the interaction between tumors and host environmental factors, we xenografted cells from the human colonic carcinoma cell lines HT29 and 5583-S in the subcutis, cecum, spleen and liver of nude mice and compared growth characteristics, metastatic potential and some phenotypic features of the xenografts in these sites. No remarkable differences were observed between the tumors at different inoculation sites in regard of their expression of carcinoembryonic antigen and secretory component or type of mucin produced. Also the proportion of DNA synthesizing cells as determined by bromodeoxyuridine incorporation appeared to be comparable in the studied implantation sites. Local invasive growth characteristics and metastatic potential, however, showed marked differences. Subcutaneous and cecal xenografts frequently showed tumor cell invasion into the surrounding tissue, vasoinvasive growth and discontinuous basement membrane deposition, whereas splenic and hepatic implants demonstrated more encapsulation, no invasion of blood vessels and more continuous basement membrane deposition. Subcutaneous xenografts produced no metastasis. With HT29 cells liver and lymph node metastases occurred frequently from the splenic as well as the cecal xenografts. 5583 cells regularly produced liver metastases from the splenic xenografts, whereas no metastasis from cecal xenografts were observed. We conclude that although the patterns of invasive growth and the metastatic potential differ for various implantation sites, antigen expression and cell kinetic features of tumor implants are hardly influenced by the site of inoculation.     

Effects of nicorandil on the recovery of reflex potentials after spinal cord ischaemia in cats.

1. The pathophysiological significance of ATP-sensitive K+ (KATP) channels in the central nervous system is not fully understood. In this study the effects of nicorandil (a hybrid vasodilator having a dual mechanism of action as a K+ channel opener and a nitrate) on the recovery of the spinal cord reflex potentials after spinal cord ischaemia were examined and compared with those of pinacidil and nitroprusside in anaesthetized spinal cats. 2. Spinal cord ischaemia was produced by occlusion of the thoracic aorta and the bilateral internal mammary arteries for 10 min. Regional blood flow in the spinal cord was continuously measured with a laser-Doppler flow meter. The monosynaptic (MSR) and polysynaptic reflex (PSR) potentials, elicited by electrical stimulation of the tibial nerve, were recorded from the lumbo-sacral ventral root. The recovery process of spinal reflex potentials was reproducible when the occlusion was repeated twice at an interval of 120 min. 3. Pretreatment with nicorandil (30-100 micrograms kg-1) accelerated the recovery of PSR potentials after spinal cord ischaemia. Such an accelerating effect on the recovery of PSR potentials was also shared by pinacidil (100 micrograms kg-1), another K+ channel opener. In addition, the accelerating effect of nicorandil (100 micrograms kg-1) on the recovery of PSR potentials was abolished by co-administration of glibenclamide (3 mg kg-1), a sulphonylurea KATP channel blocker. Nitroprusside (8 micrograms kg-1min-1) retarded rather than improved the recovery of PSR potentials after spinal cord ischaemia. All of these drugs failed to improve the spinal cord blood flow during ischaemia and reperfusion.(ABSTRACT TRUNCATED AT 250 WORDS)     

A water extract of Artemisia capillaris prevents 2,2'-azobis(2-amidinopropane) dihydrochloride-induced liver damage in rats

A water extract of Artemisia capillaris Thunberg (Compositae) was investigated for protective effects against oxidative stress induced by 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) in Sprague-Dawley male rats. Rats were orally administered A. capillaris water extract (ACWE; 7.5 g/kg) for 7 days before AAPH treatment (60 mg/kg). AAPH intoxication significantly elevated enzyme markers of liver injury (glutamic oxaloacetic transaminase and glutamic pyruvic transaminase). The pre-administration of ACWE significantly reduced the liver-damaging effects of AAPH as indicated by the low levels of these enzymes. Moreover, the ACWE administration significantly attenuated the accumulation of thiobarbituric acid-reactive substances in both plasma and liver tissues compared with those of rats administered AAPH alone. Furthermore, ACWE administration slightly improved the liver reduced glutathione levels and enhanced the production of antioxidant enzymes like catalase. A. capillaris contained 10.1 mg of catechin in 100 g of dried sample; the high-performance liquid chromatography results showed catechin composition in the ACWE to be 28% (-)-epigallocatechin gallate, 49% (-)- epigallocatechin, and 23% other catechins. These observations clearly indicate that ACWE contains antioxidant catechins capable of ameliorating the AAPH-induced hepatic injury by virtue of its antioxidant activity.     

Sensory innervation of temporomandibular joint disk

PURPOSE: To investigate the nerve endings of the adult temporomandibular joint disk, in particular the presence and configuration of the sensory nerve endings by silver staining and electron microscopy. METHODS: 20 cadaveric temporomandibular joints impregnated with silver stain were studied using an optical microscope; 2 other joints were studied using a transmission electron microscope. RESULTS: Free nerve endings were found in the disk parenchyma of all joints. Golgi-Mazzoni corpuscles, Ruffini corpuscles, and articular corpuscles were also observed as sensory nerve end organs. Myelinated and nonmyelinated nerve fibres were visualised in the disk parenchyma using the transmission electron microscope. CONCLUSION: Free nerve endings and sensory nerve end organs are present in the disk parenchyma of the human temporomandibular joint and are associated with sensation and proprioception, just as they are in the acetabular labrum, glenoid labrum, triangular fibrocartilage complex, and meniscus.     

Buserelin acetate microparticle dispersion effects drug release and plasma E(1) levels

We investigated the effect of different dispersion methods on release behavior and efficacy onset following microparticle administration of buserelin acetate (BA) sustained-release injection. In this in vitro release study, the initial dispersion of BA increased with increased stirring speed (p<0.01). Stability of BA was studied over 7 days after BA release. The initial BA release rate was higher (p<0.01) after a 1-min vibration dispersion method (VDM) using a test tube mixer (2000 rpm) compared with the standard dispersion method (SDM) by hand. Without shaking, powder aggregation was observed, and BA release was lower than in either the SDM or VDM methods. In this study using 4-week-old Sprague-Dawley female rats, the initial plasma estrone (E(1)) concentrations were lower (p<0.05) in the VDM method than in the SDM method. Observations by optical microscope and scanning microscope showed no change in microparticle shape or distribution of size induced by SDM, VDM or the ultrasonication dispersion method. These results suggest that different dispersion methods do not change the shape and distribution of microparticle size, but clearly change the BA release rate and the transition in plasma E(1) concentrations that can affect drug efficacy.     

Analysis of Inhaled Corticosteroid Selection in Patients with Bronchial Asthma Using a Questionnaire Survey—Effects of Age,Gender, and Disease Severity—

BackgroundInhaled corticosteroid (ICS) has played an important role in the management of asthma. Although several kinds of ICSs are currently available, there is no established strategy for ICS selection.MethodsUsing the data from the 2004 questionnaire surveys by the Niigata Asthma Treatment Study Group, we analyzed relationships between each patient and the ICS employed on the basis of patient background, asthma control and treatment, and indicated characteristics of ICS selection by the physician.ResultsOf 2852 cases, 2279 (79.9%) were ICS users, and 1513 (66.4% of ICS users) were classified as being in the fluticasone propionate (FP) group, 438 (19.2%) in the budesonide (BUD) group, and 240 (10.5%) in the hydrofluoroalkane-beclometasone (HFA-BDP) group, indicating that FP was a standard ICS in this study. The mean age was significantly lower in the BUD group (52.3 +/? 18.2 years) and was significantly higher in the HFA-BDP group (59.9 +/? 17.0 years) than that in the FP group (55.8 +/? 16.6 yaers). The proportion of female patients was significantly higher not in the HFA-BDP (46.5%) but in the BUD group (59.0%) than in the FP group (51.1%). These results indicated that BUD was frequently prescribed to young female and HFA-BDP was employed in the elderly patients irrespective of gender compared with FP.ConclusionsOur study indicates that ICS selection is reasonably adapted to each patient's background at least in the surveyed area. We need to elucidate the characteristics of ICS selection further in the future as new ICS and devices are developed.