An atomic force microscopy investigation of bioadhesive polymer adsorption onto human buccal cells

Atomic force microscopy (AFM) was used to examine the buccal cell surface in order to image the presence of adsorbed bioadhesive polymers identified from previous work. Isotonic saline solution (5 ml) containing either polycarbophil (pH 7.6), chitosan (pH 4.5) or hydroxypropyl methylcellulose (pH 7.6) (0.5% w/v) was exposed to freshly collected buccal cells (ca. 48×10⁴ cells/test) for 15 min at 30°C. The cells were then rinsed with a small volume of double distilled water, allowed to air-dry on a freshy cleaved mica surface and imaged using contact mode AFM. Untreated cells showed relatively smooth surface characteristics, with many small ‘crater-like’ pits and indentations spread over cell surfaces. Cells that had been treated with all the investigated polymers appeared to have lost the crater and indentation characteristic and gained a higher surface roughness. These results suggest that polymer chains had adsorbed onto the cell surfaces. Quantitative image analysis of cell topography showed significant increases (P<0.05) in arithmetic roughness average (R_a) for all the investigated polymer treated cells surfaces with respect to untreated control specimens. The changes in surface topography indicate the presence of adsorbed polymer, confirming previous work. This study demonstrates the suitability of AFM as a powerful and sensitive technique for detecting and imaging bioadhesive polymers present on mucosal cell surfaces.     

燃煤砷污染对人体血细胞DNA合成、DNA损伤及修复的影响

目的与方法：采用液体闪烁计数法及＾１２５Ｉ后标记法检测燃煤型砷中毒人群血细胞ＤＮＡ自发合成、ＤＮＡ－蛋白质交联物（ＤＰＣ）水平及非程序外ＤＮＡ合成（ＵＤＳ）反应,以探讨燃煤砷污染以人体ＤＮＡ合成、ＤＮＡ损伤及修复的影响。结果：病区非病人及中毒病人的ＤＮＡ合成明显降低,ＤＰＣ水平随病情加重而升高;而ＵＤＳ反应则只在中毒病人体内增强,差异均有显著性。结论：燃煤砷可在早期致人体内ＤＰＣ形成,引起严重的Ｄ     

Thrombospondin-1 expression in oral squamous cell carcinomas: correlations with tumor vascularity, clinicopathological features and survival

Thrombospondin-1 (TSP-1) is a 450 kd glycoprotein synthesized and incorporated into the extracellular matrix by numerous cell types and reported to suppress tumor growth and progression by its inhibition of angiogenesis. In order to clarify the biological role of TSP-1 and determine its clinicopathological significance in oral squamous cell carcinomas (SCCs), we identified TSP-1 protein expression in 54 oral SCCs by immunohistochemistry and correlated it with microvessel density (MVD), clinicopathological features and patient's survival. Thirty-two out of 54 carcinomas (59%) were identified as having a low level of TSP-1 expression (TSP-1-L), and 22/54 (41%) carcinomas identified as having a high level of TSP-1 expression (TSP-1-H). The MVD counts (mean±S.D.=9.0±4.9) in TSP-1-H tumors was significantly lower than that (mean±S.D.=12.7±4.4) in TSP-1-H tumors (P=0.0065). The level of TSP-1 expression was not correlated with T category and histologic grade, but inversely correlated with the pattern of tumor invasion (P=0.0136) and with lymph nodal status (P=0.0119). Furthermore, Kaplan–Meier analysis showed that the 5-year survival rate of TSP-1-H group was significantly higher than that of TSP-l-L group. Our results suggested that TSP-1 expression exerts an inhibitory effect on tumor vascularity, and that it has value in assessment of aggressiveness and prognosis of oral SCCs.     

Behavior of squamous cell carcinoma of the floor of the mouth. Is supraomohyoid neck dissection sufficiently safe to manage clinically N0 patients?

Aim

The main aim of the present report is to study the behavior of SCC of the floor of the mouth.

The contribution of gustatory nerve input to oral motor behavior and intake-based preference. I. Effects of chorda tympani or glossopharyngeal nerve section in the rat

Two-bottle intake tests and taste reactivity (TR) tests were used to reveal whether changes in ingestive behavior would follow bilateral section of either the chorda tympani (CT) or the glossopharyngeal (GP) nerve. Rats received two-bottle intake tests to compare 24-h ingestion of water to that of NaCl, MgCl2, quinine, or sucrose. Prior to each long-term intake test, rats received a 1 min, 1 ml intraoral infusion of the same chemical stimulus. Ingestive and aversive oral motor responses elicited by these 1 ml infusions were videotaped and subsequently analyzed. GP-section did not alter quinine or sucrose preference; overall, preference of MgCl2 and NaCl was also similar to controls. In contrast, TR tests in GP-sectioned rats revealed that most quinine, MgCl2 and NaCl stimuli elicited significantly fewer aversive oral motor responses. In addition, the latency of aversive responses to these 3 chemical stimuli was increased for these rats. Intake-based preference tests failed to show any difference between rats with CT nerve section and controls. In TR tests, however, CT-sectioned rats displayed significantly fewer ingestive oral motor responses to NaCl, MgCl2, and quinine than controls. Neither sucrose intake nor sucrose-elicited TR were altered by CT or GP nerve section. This report confirms the failure of long-term intake tests to uncover behavioral deficits following the section of gustatory nerves. In contrast, the use of a different behavioral test makes clear for the first time that gustatory nerve section has dramatic consequences on ingestive behavior. The examination of taste elicited oral motor behaviors reveals a coherent and nerve specific pattern of neurological deficit following peripheral nerve section.     

Metabolic control after kidney and pancreas transplantation: whole series results and effects of segmental duct obstruction versus whole pancreas with bladder diversion technique

From October 1976 to December 1990 181 pancreatic transplants were performed in our centre on 171 Type 1 (insulin-dependent) diabetic patients. Oral glucose tolerance test evaluated 1 year after surgery in 31 subjects showed an impaired glucose tolerance at 120 min (blood glucose 9.5±0.6 mmol/l). Similar results were obtained in seven patients 3 years after transplantation (blood glucose at 120 min 8.3±1.08 mmol/l). 24h metabolic profiles performed at the same intervals showed near normal blood glucose levels and good insulin release. Preliminary data concerning a randomized, comparative study between whole pancreas with bladder diversion and segmental pancreas transplantation, showed better metabolic control in the patients who received the whole pancreas, probably due to the greater islet mass grafted.     

Acquisition of oral phencyclidine (PCP) self-administration in rhesus monkeys: effects of dose and an alternative non-drug reinforcer

 The effects of drug dose and a non-drug alternative reinforcer on acquisition of oral PCP self-administration in rhesus monkeys were examined. Acquisition was studied using three groups of monkeys (seven subjects per group). One group received a low PCP dose (0.0375 mg/delivery) and the other two received a high PCP dose (0.15 mg/delivery). One of the high dose groups had concurrent access to a saccharin solution (0.03% w/v) and water during the intersession (17.5-h) period. Food non-restricted monkeys were initially given access to water under a fixed-ratio (FR) 1 schedule during daily 3-h sessions. Water was then replaced with PCP during the session. The monkeys were then reduced to 85% of their free-feeding body weights and fed before the session, and the FR value was increased from 1 to 2, 4 and 8. Subsequently, food was given post-session and water and PCP were available under concurrent FR 8 schedules. At this final step of the procedure, acquisition of PCP self-administration was considered to occur if PCP intake consistently exceeded water intake. When all three groups were given concurrent access to PCP and water, PCP intake was greater than water intake only in the group of monkeys receiving the high PCP dose. PCP intake increased when water replaced saccharin during intersession in the high PCP dose group. Within-group data revealed that 85.7% of monkeys acquired PCP reinforcement in the group given access to the high PCP dose while only 42.8% acquired in the other two groups. These data suggest that drug dose and presence of alternative non-drug reinforcers affect acquisition of drug self administration in non-human primates. Received: 14 May 1997 / Final version: 15 December 1997     

HPLC测定芎芷香苏散流浸膏中橙皮甙的含量

本文用ＨＰＬＣ测定芎芷香苏散流浸膏中橙皮甙的含量，以甲醇－冰醋酸水溶液为流动相，ＵＶ－２８０ｎｍ，在２５－２００μｇ＝ｍｌ范围内线性关系良好，ｒ＝０．９９９９，提取和测定方法简便，回收率高。     

The descriptive epidemiology of pharyngeal cancer in Scotland

There have been recent reports of substantial increases occurring in the incidence of and/or mortality from tongue and mouth cancers in several countries. In this paper using data from Scotland (1960–89) we report on time trends in pharyngeal cancer. Similar increases in rates are evident for cancers of the oropharynx and hypopharynx while there has been little change in the occurrence of nasopharyngeal cancer (which has distinct aetiological factors). It therefore seems that reported changes in the incidence of and mortality from oral cancer may be real, and in Scotland, this is most probably due to changes in alcohol consumption.Corresponding author.     

顶空气相色谱连续监测鼠伤寒沙门氏菌致突变试验研究

在密闭的液体培养体系中，以ＣＯ２为指标用气相色谱分析法连续监测致突变剂ＮａＮ３和敌克松对鼠伤寒沙门氏菌组氨酸缺陷型菌株ＴＡ１００、ＴＡ９８的致突变作用，研究了回复突变菌数、致突变剂的剂量与ＣＯ２产生量之间的关系，在此基础上提出了致突变性的评价指标。用本方法测得ＮａＮ３和敌克松的最低诱变剂量分别为０．０５０μｇ／瓶和０．０８０μｇ／瓶，灵敏度显著高于Ａｍｅｓ试验。