5-HT1B receptor-mediated contractions in human temporal artery: evidence from selective antagonists and 5-HT receptor mRNA expression

1. In the human temporal artery both 5-HT_1-like and 5-HT_2A receptors mediate the contractile effects of 5-hydroxytryptamine (5-HT) and we have suggested that the 5-HT_1-like receptors resemble more closely recombinant 5-HT_1B than 5-HT_1D receptors. To investigate further which subtype is involved, we investigated the blockade of 5-HT-induced contractions by the 5-HT_1B-selective antagonist SB-224289 (2,3,6,7-tetrahydro-1′-methyl-5-{2-methyl-4′[(5-methyl-1,2,4-oxadiazole-3-yl) biphenyl-4-yl] carbonyl} furo[2,3-f]indole-3-spiro-4′-piperidine oxalate) and the 5-HT_1D-selective antagonist BRL-15572 (1-phenyl-3[4-3-chlorophenyl piperazin-1-yl] phenylpropan-2-ol). We also used RT-PCR to search for the mRNA of 5-HT_1B, 5-HT_1D and other 5-HT receptors.
2. The contractile effects of 5-HT in temporal artery rings were partially antagonized by SB-224289 (20, 200 nM) (apparent K_B=1 nM) and ketanserin (1 μM) but not by BRL-15572 (500 nM).
3. Sumatriptan evoked contractions (EC₅₀, 170 nM) that were resistant to blockade by BRL-15572 (500 nM) but antagonized by SB-224289 (20, 200 nM).
4. The potency of 5-HT (EC₅₀) was estimated to be 94 nM for the ketanserin-sensitive receptor and 34 nM for the SB-224289-sensitive receptor. The fraction of maximal 5-HT response mediated through SB-224289-sensitive receptors was 0.20–0.67, the remainder being mediated through ketanserin-sensitive receptors.
5. We detected arterial receptor mRNA for the following receptors (incidence): 5-HT_1B (8/8), 5-HT_1D (2/8), 5-HT_1F (0/4), 5-HT_2A (0/8), 5-HT_2B (0/8), 5-HT_2C (0/8), 5-HT₄ (4/8) and 5-HT₇ (4/8).
6. We conclude that the ketanserin-resistant fraction of the 5-HT effects and the effects of sumatriptan are mediated by 5-HT_1B receptors. The lack of antagonism by BRL-15572 rules out 5-HT_1D receptors as mediators of the contractile effects of 5-HT and sumatriptan.

     

Human tubal fluid: production, nutrient composition and response to adrenergic agents

Vascularly perfused Fallopian tubes have been used to study the formation and composition of human tubal fluid and the response to adrenergic agents. An artery serving the tube was cannulated and perfused with Medium 199 supplemented with bovine serum albumin (BSA) and antibiotics. A second cannula was attached to the fimbriated end for native tubal fluid collection. The preparation was viable for up to 2 h. Tubal fluid was only obtained in tubes removed in the proliferative and early secretory phases of the ovarian cycle. Isoproterenol (1 mM) added to the perfusate stimulated fluid production, whereas dibutyryl cyclic AMP (1 mM) reduced fluid formation by 66%. Glucose, pyruvate and lactate concentrations in tubal fluid, measured by microfluorescence assays, were 1.11, 0.14 and 5.4 mM respectively. The concentrations of 17 amino acids in tubal fluid were measured by high performance liquid chromatography following fluorescence derivatization. Arginine (0.19 mM) > alanine (0.11 mM) > glutamate (0.09 mM) were present in highest concentration in all phases of the cycle. All 17 amino acid concentrations in tubal fluid were below those in the vascular perfusate. These data provides the basis for a culture medium whose composition mimics the physiological environment to which early human embryos are exposed.      

Transient osteoporosis: transient bone marrow edema?

Ten patients with debilitating hip or knee pain were examined with magnetic resonance (MR) imaging. All had conventional radiographs that were either normal or showed nonspecific osteopenia. Nine patients had bone scintigrams that showed focal increased radionuclide uptake in the region of the painful joint. In each case, MR images of the affected joint showed regional decreased signal intensity of the bone marrow on T1-weighted images and increased signal intensity on T2-weighted images. Biopsy results of four patients excluded ischemic necrosis and metastases. The symptoms resolved spontaneously in all cases. The ten patients were followed up for 12-36 months, and there were no recurrences. The authors believe that the findings on MR images represent a transient increase in bone marrow water content. The focal findings on scintigrams confirmed the periarticular distribution of the process and provided evidence of accompanying hyperemia and increased bone mineral metabolism. For lack of a better term and to emphasize the generic character of the condition, the authors termed this condition "the transient marrow edema syndrome."     

四种中国产牙膏磨损性的评价

目的：观察4种中国产牙膏对人牙本质的磨损性。方法：将新鲜拔除的人健康恒牙包埋于环氧树脂块中，表面磨平。开一牙本质窗并在刷牙机上刷1000次，以Talysurf2表面测量仪测量牙本质磨损程度。结果：多数中国产牙膏具有较高的磨损性。结论：长期使用有潜在的导致牙齿磨损的可能性。     

Peripheral giant cell granuloma: a clinical study of 77 cases from 62 patients, and literature review

OBJECTIVES: The aim of this study was to identify the principle clinical features of the peripheral giant cell granuloma (PGCG), and to recognise clinical features of PGCG that are poorly defined.
DESIGN: We reviewed retrospectivety 77 cases of PGCG from 62 patients, from our files with respect to incidence, sex, patient age, race, clinical symptoms and signs, radio-graphic features and recurrence following excision.
RESULTS AND CONCLUSIONS: Our results were largety in agreement with previous reports, although there is wide variation in the results published between series. In addition, some clinical features of PGCG are poorly defined. Little is known about the retative incidences of PGCG and central giant cell granuloma. An association between PGCG and tooth loss may exist, but is poorly defined, and not all PGCG that involve edentulous areas follow recent tooth loss. Information about PGCG recurrence after excision is limited, and does not necessarily follow incomplete excision. Despite the large number of reported cases of PGCG, clarification of some clinical features is required, and may hetp formulation and interpretation of future laboratory-based research into this poorly understood lesion.     

牙本质陶瓷粉、非胶原蛋白及其复合材料对修复性牙本质形成作用的研究

目的：观察牙本质陶瓷粉（ceramic demtin powder,CDP)、CDP与非胶原蛋白（noncollagenous proteins,NCPs）复合材料（CDP／NCPs）对修复性牙本质形成的作用。方法：牙本质粉煅烧后与人牙本质NCPs复合，用SD大鼠牙作直接盖髓实验，并用组织学方法评价修复性牙本质形成的效果。结果：术后14d，CDP组：穿髓下方可见少许成牙本质细胞。CDP／NCPs组：穿髓孔周围见成纤维细胞增殖，呈团块状包绕穿髓孔。术后28d，CDP组：穿髓下方可见少量修复性牙本质团块形成。CDP／NCPs组：可见大量修复性牙本质形成。结论：CDP／NCPs能促进大鼠牙体、牙髓组织修复。     

A comparative study of oral health knowledge,attitude and behaviour of first and final year dental students of Udaipur city,Rajasthan, India

Abstract: Objective: To assess and compare differences in oral health knowledge, attitudes and behaviour among first and final year dental students in Udaipur city, Rajasthan, India. Materials and methods: In a cross‐sectional study, 182 first year students (59 males and 123 females) and 157 final year students (75 males and 82 females) of the two dental colleges in Udaipur city; Rajasthan, were surveyed using a self‐administered structured questionnaire including 37 multiple choice questions pretested through a pilot survey. The data was analysed using the spss version 10.0. The mean percentage scores, standard deviation and frequency distribution were calculated. The Student’s t‐test and anova test were used as test of significance. The linear regression analysis were used to assess the relation of knowledge, attitude and behaviour. Results: The mean % score for oral health knowledge, attitude and behaviour were significantly higher in final year students compared to first year students (P < 0.001). The linear regression analysis showed a statistically significant linear relationship of attitude with the knowledge (P < 0.001) and behaviour with the attitude (P < 0.001) of the students. Conclusion: Besides the positive changes revealed in the oral health knowledge, attitude and behaviour, among the students from first to final year of dental studies, preventive behaviour among the students could still be improved.