Molar furcation entrance and its relation to the width of curette blades used in periodontal mechanical therapy

Abstract: Aim:  The purpose of this research was to evaluate molar furcation entrances and the width of periodontal curette blades used in periodontal instrumentation.
Materials and methods:  One hundred extracted molars (50 upper and 50 lower) were analysed. The furcation entrances were measured using orthodontic wires of different predetermined diameters: 0.4, 0.5, 0.6, 0.7, 0.8 and 0.9 mm. McCall 17–18, Gracey 5–6 and Gracey 5–6 mini-five curette blades were measured at their anterior (AT), middle (MT) and posterior (PT) thirds by a single trained investigator, through the use of a digital caliper.
Results:  The results showed significant differences ( P  < 0.0001) in relation to furcation entrances. The buccal upper molar furcations showed the narrowest dimensions. In relation to the blade diameter, significant differences among the instruments were found for their MT and PT ( P  < 0.0001), but not for the AT ( P  = 0.183). Significant differences were found among curette manufacturers. Nineteen per cent of evaluated furcations presented entrances <0.60 mm and 75% of the blades at their AT presented width >0.60 mm.
Conclusions:  These findings demonstrated that some molar furcation entrances could not be adequately instrumented with the tested curettes. The use of other hand instruments, such as periodontal files, rotating instruments and ultrasonic devices should be taken into consideration during periodontal therapy.     

MRI预测垂体腺瘤质地指导手术入路

1 临床资料 2002-02/2003-02术后病理证实垂体腺瘤患者肿瘤直径>1 cm,影像学资料齐全84(男37,女47)例,年龄14～76(平均44)岁,病史2 wk～20 a. 以肿瘤的占位效应为主诉49例(58%),其中视力视野改变47例,头痛42例,呕吐以及意识障碍各2例,因内分泌紊乱为主诉35例(42%),其中闭经25例,不孕17例,泌乳5例,性功能减退6例,肢端肥大10例.     

前房角切开术治疗青少年型开角型青光眼

小梁切除术联合丝裂霉素C是治疗青少年型开角型青光眼(junior open-angle glaucoma,JOAG)较常用的术式,缺点是存在低眼压性黄斑病变、滤过泡渗漏等潜在并发症的可能.前房角切开术是治疗原发性婴幼儿型青光眼较常用的术式.作者报告了波士顿市马萨诸塞眼耳医院采用前房角切开这一轻度侵人性手术治疗青少年型开角型青光眼的结果.     

Postoperative annular pseudocyst: report of two cases with an unusual complication after microdiscectomy, and successful treatment by percutaneous aspiration and steroid injection

BACKGROUND CONTEXT: After microdiscectomy for extruded disc fragments, patients may develop recurrent symptoms from numerous causes. Postoperative annular pseudocysts represent a unique entity not previously described in the medical literature. PURPOSE: To report unique imaging findings in two patients who presented with recurrent radiculopathic symptoms after microdiscectomy. To report successful percutaneous aspiration and steroid injection in one of these cases. STUDY DESIGN/SETTING: Report of two cases. METHODS: Two patients underwent preoperative imaging with noncontrast magnetic resonance imaging (MRI) and postoperative imaging with pre- and postcontrast MRI. One of these patients underwent therapeutic computed tomography (CT)-guided aspiration and injection. RESULTS: MRI demonstrated T2 hyperintense and enhancing collections, which conformed to the shape of the resected disc fragment and communicated with the disc annulus. One of these cases demonstrated enlargement over several months with worsening of symptoms. Aspiration of the lesion produced thick fluid. The patient experienced marked relief of symptoms after the aspiration and injection of steroid into the lesion. CONCLUSIONS: The unique imaging findings in these patients represent a previously undescribed complication of microdiscectomy, which we have termed "postoperative annular pseudocyst." We have successfully treated one case with CT-guided percutaneous aspiration and injection.     

Cloning and pharmacological characterization of the dog P2X7 receptor

Background and purpose:

Human and rodent P2X7 receptors exhibit differences in their sensitivity to antagonists. In this study we have cloned and characterized the dog P2X7 receptor to determine if its antagonist sensitivity more closely resembles the human or rodent orthologues.

Experimental approach:

A cDNA encoding the dog P2X7 receptor was isolated from a dog heart cDNA library, expressed in U-2 OS cells using the BacMam viral expression system and characterized in electrophysiological, ethidium accumulation and radioligand binding studies. Native P2X7 receptors were examined by measuring ATP-stimulated interleukin-1β release in dog and human whole blood.

Key results:

The dog P2X7 receptor was 595 amino acids long and exhibited high homology (>70%) to the human and rodent orthologues although it contained an additional threonine at position 284 and an amino acid deletion at position 538. ATP possessed low millimolar potency at dog P2X7 receptors. 2′-&3′-O-(4benzoylbenzoyl) ATP had slightly higher potency but was a partial agonist. Dog P2X7 receptors possessed relatively high affinity for a number of selective antagonists of the human P2X7 receptor although there were some differences in potency between the species. Compound affinities in human and dog blood exhibited a similar rank order of potency as observed in studies on the recombinant receptor although absolute potency was considerably lower.

Conclusions and implications:

Dog recombinant and native P2X7 receptors display a number of pharmacological similarities to the human P2X7 receptor. Thus, dog may be a suitable species for assessing target-related toxicity of antagonists intended for evaluation in the clinic.