Classification and diagnostic criteria for oral lesions in HIV infection

A consensus has been reached on the classification of the oral manifestations of HIV infection and their diagnostic criteria, based on presumptive and definitive criteria. The former relate to the initial clinical appearance of the lesion and the latter are often the result of special investigations. Candidiasis, hairy leukoplakia, specific forms of periodontal disease [linear gingival erythema, necrotising-(ulcerative) gingivitis and necrotising(ulcerative) periodontitis], Kaposi's sarcoma and non-Hodgkin's lymphoma are strongly associated with HIV infection. Lesions less commonly associated with HIV infection and lesions seen in HIV infection, but not indicative of the disease, are also listed.     

Axonal regeneration in dorsal spinal roots is accelerated by peripheral axonal transection

Regeneration of crushed axons in rat dorsal spinal roots was measured to investigate the transganglionic influence of an additional peripheral axonal injury. The right sciatic nerve was cut at the hip and the left sciatic nerve was left intact. One week later, both fifth lumbar dorsal roots were crushed and subsequently, regeneration in the two roots was assessed with one of two anatomical techniques. By anterograde tracing with horseradish peroxidase, the maximal rate of axonal regrowth towards the spinal cord was estimated to be 1.0 mm/day on the left and 3.1 mm/day on the right. Eighteen days after crush injury, new, thinly myelinated fibers in the root between crush site and spinal cord were 5-10 times more abundant ipsilateral to the sciatic nerve transection. The central axons of primary sensory neurons regenerate more quickly if the corresponding peripheral axons are also injured.     

Transmission electron microscopy of early microbial colonization of human enamel and root surfaces in vivo

Abstract – This study describes the early microbial colomization of teeth by the use of light-and transmission electron microscopy. Six dental students carried a total of 60 test pieces of unerupted enamel and root surface in intraoral acrylic appliances for 4, 8, 12, 24 and 48 h, during which periods oral hygiene was abandoned. Pronounced variations were recorded in structure and thickness of the pellicle across the individual surfaces of both dental tissues. Bacterial single-cell colonization increased the electron density of the adjoining pellicle. Micro-colonies of bacteria were observed in relation to enamel surface irregularities such as perikymata, while the distribution on root surfaces appeared incidental. Root surfaces were generally colonized by thicker deposits than homologous enamel surfaces although the structural composition of the microbiota was similar. Gram-positive bacteria with thick cell walls appeared in coccoid or rod-shaped configurations depending on the age of the bacterial deposit. These bacteria were further characterized by selective invasion between collagen fibers. After 48 h the complexity of the microbiota was increased by the establishment of new bacterial species in the superficial layer. It is concluded that the pattern and composition of the early microbiota on teeth is more complex and variable than hitherto assumed.     

神经根变异与特殊型椎间盘突出症

回顾5例由于神经根变异或特殊类型椎间盘突出引起的腰腿痛病人,对其病理及术中处理做了介绍,认为由于神经根的解剖变异,更容易受到椎间盘突出的卡压。手术中如临床症状符合椎间盘突出症,而预定探查间隙未发现突出物,或与临床症状不符者,应根据神经根激惹及松紧程度,扩大探查范围,查明造成疼痛的原因,避免二次手术。     

Single visit root canal treatment: incidence of postoperative pain using three different instrumentation techniques

A clinical study was carried out on nonvital maxillary central incisors to evaluate the incidence of postoperative pain following single-visit root canal treatment using three different instrumentation techniques. Ninety teeth from 78 patients whose ages ranged from 14 to 63 years were selected and divided into three groups. Each group (30 teeth) was prepared by a different coronal-to-apical technique using different instrument movement depending upon the technique employed: modified double-flared, crown-downpressureless and balanced force techniques. No difference was observed in the incidence of postoperative pain among the groups.     

家兔肝的神经支配

本实验共用家兔17只,将20%的HRP溶液100μl,经肝门多点注入,其中10只家兔出现标记细胞.两侧T_(2-12)背根节内共270个,左侧占51.11±3.04%,右侧为48.89±3.04%,左、右侧差异无显著性(P>0.05).在T_(5-8)背根节内的标记细胞较多,占总数的59.26±2.99%,中、小型细胞共占94.53±1.60%.两侧结状神经节内的标记细胞共143个.左侧占53.15±4.17%,右侧占46.85±4.17%.两侧差异无显著性.中、小型细胞共占93.01±2.13%.两侧腹腔神经节内的标记细胞较多,计数其中2例,共582个,左侧占59.79±2.03%,右侧为40.21±2.03%.在迷走神经背核内仅发现2个标记细胞.     

Persistent bone marrow failure with dysplastic features following pentostatin therapy for hairy cell leukaemia

Myelodysplastic syndromes (MDS) have rarely been reported after treatment with nucleoside analogues, and mainly in patients who have also received alkylating agents. We report a patient who developed MDS (refractory anaemia with ring sideroblasts) after treatment with pentostatin (deoxycoformycin) alone.     

The relation between conduction velocity and axonal length

Motor evoked potentials (MEPs) obtained by electrical root stimulation and F waves were used to examine the proximal nerve conduction velocity (CV) to tibialis anterior (TA), extensor digitorum brevis (EDB), flexor carpi radialis (FCR), and abductor pollicis brevis (APB) muscles in 40 humans. By subtracting motor latencies obtained by stimulating the peripheral nerve at the same point from the F-wave and MEP latencies, we could measure the CV over identical proximal segments. It was found that proximal CV to TA and FCR was significantly higher than to EDB and APB, respectively. Combining the data of the proximal CV to all four muscles in relation with axonal length resulted in a highly significant inverse relationship (r² = 0.77). Thus the axonal length explained to a large extent the higher CV of the arm nerves and also the inverse relation between body height and CV. The distal CV was always lower than proximal CV; however, there was no support for an additional effect of this gradient in explaining the relationship between CV and height since it was constant for all body heights. © John Wiley & Sons, Inc.     

部分背根切断对备用背根节NT-3表达的影响

目的　探讨部分去背根后备用背根节 (L6 )各类细胞NT 3及其mRNA的含量变化。　方法　对成年雄性猫行单侧部分背根切断术 (切除一侧L1 ～L5,L7～S2 DRG ,保留L6 为备用根 )。取正常组一侧和术后 3d及 7d组手术侧的L6 DRG制作 2 0 μm厚冰冻切片 ,分别用NT 3抗体及NT 3cRNA探针行免疫组织化学及原位杂交染色。观察NT 3及其mRNA在DRG各类细胞的分布 ,测定NT 3及其mRNA在神经元和卫星细胞的光密度值 ,所得数据用q检验进行统计分析。　结果　部分去背根后 ,各时相备用背根节大神经元内NT 3的光密度值较正常者进行性减少 ,(P <0 0 5 ) ,而NT 3mRNA的光密度值术后 3d减少 ,7d回升至近正常者水平。比较之 ,小神经元和卫星细胞NT 3及其mRNA的光密度值进行性增多 (P <0 0 5 )。　结论　部分背根切断对备用背根节各类细胞NT 3表达的影响不同 ,其功能意义可能与NT 3参与脊髓Ⅱ板层可塑性有关     

家兔内脏大神经传入神经元的节段分布

为探明内脏大神经传入神经元在后根节内的节段分布,本研究将家兔的左侧内脏大神经中枢侧断端浸泡于HRP溶液中。其HRP标记细胞的节段范围为胸_2——胸_(12)节,并以胸_5——胸_(11)节为多。91.2%HRP标记细胞的直径在34微米以下。