Perception of anatomical structures in digitally filtered and conventional panoramic radiographs: a clinical evaluation

Objectives

The aims of the study were to compare subjective image quality of clinical images obtained with a storage phosphor plate (SPP)-based digital and conventional film-based panoramic system for the visualization of various anatomical structures and to evaluate the effect of various processing algorithms on image interpretation.

Methods

Panoramic radiographs were taken in 42 patients both with film and with a SPP system. SPP images were treated with shadow, sharpen, negative, greyscale sigma and greyscale exponential filters. Four observers subjectively evaluated films and unfiltered and filtered SPP images for the visibility of anatomical structures with various radiodensities as well as for overall image quality on a three-point rating scale. The statistical methods used were Kruskal–Wallis, odds ratio analysis and Cohen''s kappa.

Results

No statistically significant difference was found between film and unfiltered digital images except for low-contrast structures (P > 0.05). Film images were preferred for the visibility of low-contrast structures (P < 0.05). Best overall image quality was obtained with sharpened images (P < 0.05) followed by films and unfiltered digital images. Among all filtered images, sharpened ones received the highest ratings for the visibility of all anatomical structures (P < 0.05). The intra- and interobserver agreement ranged between moderate and substantial and between fair and moderate, respectively.

Conclusions

Film and unfiltered SPP-based panoramic images performed equally well in terms of overall quality; however, films were best for the perception of low-contrast structures. The sharpening filter may be recommended for enhancing SPP panoramic images to improve the visual perception of most of the anatomical structures as well as overall quality.     

Neuromuscular features in Marfan syndrome

Marfan syndrome is a clinically and allelic heterogeneous, heritable connective tissue disorder with infrequently reported neuromuscular features. This study is the first to delineate these symptoms in a non-selected population. Neuromuscular involvement was evaluated in 10 Marfan patients through a standardized questionnaire, physical examination, nerve conduction study (NCS), needle electromyography (EMG), muscle ultrasound, laboratory investigation, and muscle biopsy. Existing neuroimages were screened for dural ectasia and spinal meningeal cysts. Twenty healthy controls with similar age distribution completed the questionnaire.
The results showed that various neuromuscular symptoms occur more frequently in the patients. Four older patients reported muscle weakness, five patients had a mild-to-moderate reduction in vibration sense, and all older patients mentioned mild functional impairments. NCS showed axonal polyneuropathy in four and EMG myopathic and neurogenic changes in all patients. Increased echo intensity and atrophy on muscle ultrasound was found in more than half of the patients. Muscle biopsies obtained in two patients showed myopathic changes in the older, female patient.
In conclusion, the majority of Marfan patients exhibited neuromuscular symptoms characterized as myopathy or polyneuropathy or both, and signs of lumbosacral radiculopathy, with symptoms being most pronounced in the older patients. Although meriting corroboration, these findings indicate a need to further the awareness of neuromuscular involvement in this population.     

完全去神经大鼠皮肤愈合过程中神经纤维再生和降钙素基因相关肽的变化

目的:观察完全去神经对大鼠皮肤伤口愈合的影响及愈合过程中神经纤维再生和降钙素基因相关肽的变化情况,探讨神经纤维再生和降钙素基因相关肽与伤口愈合的关系。方法:实验于2006-02在北京大学人民医院中心实验室完成。雌性Wistar大鼠32只,体质量250～300g。切断所有大鼠右下肢的坐骨神经和股神经,然后分别制造1cm的圆形皮肤缺损作为去神经组,在大鼠左下肢相应部位制造同样皮肤缺损作为对照组,于伤后1,3,7,14d每个时间点随机处死8只大鼠,用3M贴膜覆盖于伤口,然后沿切口周围1cm切取伤口组织,观察伤口愈合情况,组织化学染色观察神经丝蛋白和降钙素基因相关肽的变化。结果:纳入大鼠32只,均进入结果分析,伤口无感染。①两组大鼠伤后7d的伤口面积比伤后1d均明显缩小[去神经组:(0.195±0.053),(0.687±0.053)cm2;对照组:(0.131±0.041),(0.562±0.088)cm2]。与对照组相比,去神经组伤后3d大鼠的伤口面积无明显变化[(0.366±0.031),(0.408±0.079)cm2,P>0.05]。②去神经组伤口的神经丝蛋白和降钙素基因相关肽阳性染色在伤后第1,3,7,14天均明显少于对照组。结论:完全去神经后皮肤伤口愈合缓慢,而伤口内的神经纤维再生缓慢和降钙素基因相关肽的减少与皮肤伤口愈合缓慢有着密切关系。     

经紫外线预照射移植猪皮片覆盖烧伤创面时间的观察

目的:观察经紫外线预照射移植猪皮片对烧伤创面覆盖时间的影响。方法:选择2004-01/2005-12四川攀枝花钢铁有限责任公司职工总医院烧伤科收治的需要植皮的烧伤患者35例,患者均知情同意。按随机数字表法分为2组,紫外线预照射组18例,对照组17例。紫外线预照射组使用的猪皮片经过40W紫外线预照射,波长为253.7nm,灯管距猪皮30cm,照射时间2h;对照组使用的移植猪皮片未做紫外线预照射。将移植猪皮片真皮面覆盖于切削痂创面上,加压包扎,用手术刀片打洞以利引流。观察整体猪皮片的存活时间,在术后5,10,15d取0.2cm×0.3cm大小的整层猪皮制成匀浆,检测相关生化因子水平:应用双抗体夹心酶联免疫吸附法测肿瘤坏死因子α含量,应用鲎法测内毒素含量,应用黄嘌呤氧化酶法测超氧化物歧化酶活性,应用硫代戊巴比妥酸法测丙二醛含量。移植猪皮片出现外观苍白,与创面分离,融解脱落均视为失效。结果:35例烧伤患者全部进入结果分析,无脱落。①紫外线预照射组猪皮平均烧伤创面覆盖时间为(18.3±2.4)d,显著高于对照组(13.7±3.1)d(P<0.05)。覆盖猪皮术后15d,紫外线预照射组有3例移植猪皮片失效,对照组有9例移植猪皮片失效。②随时间延长,两组患者覆盖猪皮片局部组织匀浆肿瘤坏死因子α、内毒素、丙二醛含量均呈升高趋势,术后10d和15d紫外线预照射组显著低于对照组(P<0.01)。两组患者覆盖移植猪皮片局部组织匀浆超氧化物歧化酶活性随时间延长均呈下降趋势,术后10d和15d紫外线预照射组显著高于对照组(P<0.01)。结论:紫外线预照射新鲜猪皮用于覆盖烧伤创面能明显延长创面保护时间,其作用途径可能与减轻局部组织脂质过氧化反应程度及炎性因子水平有关。     

Management of protozoal diarrhoea in HIV disease

Summary Since the first reported case of HIV infection in 1981, many HIV-seropositive patients have died as a result of diarrhoea induced by opportunistic protozoal infections: pathogens that would normally cause only a transient illness in immunocompetent individuals. The introduction of highly active antiretroviral therapy (HAART) in 1996 has been associated with a significant decline in incidence and mortality arising from infections such as cryptosporidia and microsporidia. Previously, there were no chemotherapeutic agents known to be effective in eradicating these parasites, but since the availability of HAART, the memory of the emaciated terminally ill patient with advanced AIDS suffering from refractory diarrhoea will hopefully be a thing of the past. Significant advances in the knowledge of the pathogenesis of HIV disease, earlier detection and thus treatment of the virus, and availability of improved diagnostic techniques and HAART have transformed the way HIV-associated diarrhoea is managed. In this review, we look specifically at the management of protozoa-induced diarrhoea.     

Chronic erosive herpes simplex virus infection of the penis, a possible immune reconstitution disease

Objective To report a novel clinical presentation: a chronic erosive herpes simplex virus (HSV) infection of the penis which developed in AIDS patients following the commencement of highly active antiretroviral therapy (HAART). The lesions were unresponsive to antiviral treatments which had previously been effective, and this could not be accounted for in terms of increased antiviral resistance.
Design Detailed case-note review and investigation of three cases which presented at two large HIV units in London.
Methods Review of all histology with immunohistochemistry for HSV, HSV drug susceptibility assays, tissue typing and measurement of in vitro lymphocyte functional activity against HSV.
Results The histology of the lesions was the same in each case, with the presence of HSV on immunohistochemistry and an unusual prominence of plasma cell and eosinophils in the inflammatory infiltrate. HSV-specific lymphoproliferative responses were normal in two cases, but subnormal in a third case. All individuals shared the HLA class I molecules B72 and Cw0202 and the class II allele DRB4.
Conclusion We believe this to be a previously unreported adverse consequence of HAART, the result of partial immune restoration, reminiscent of the the recently described syndrome of immune recovery vitritis.     

Enteric viral infections as a cause of diarrhoea in the acquired immunodeficiency syndrome

Background and aims The role of non-cytomegalovirus (CMV) enteric viral infection in causing diarrhoea in patients with human immunodeficiency virus (HIV) is poorly understood. We aimed to investigate the prevalence of these infections in acute and chronic diarrhoea. Methods Stool specimens from 377 HIV-infected patients presenting with diarrhoea were studied prospectively for evidence of non-CMV enteric viral infection. Patients with diarrhoea underwent investigation for gastrointestinal pathogens, including electron microscopic examination of stool for enteric viruses. We collected data on patients in whom enteric virus was identified and examined the association of enteric virus infection with diarrhoeal symptomatology. Results Eighty-nine (10.3%) stool specimens from 60 (15.9%) HIV⁺ individuals were positive for coronavirus (n = 13, 22%), rotavirus (n = 11, 18%), adenovirus (n = 30, 50%) and small round structured viruses (n = 5, 8%) or dual infection (n = 2, 3%). Thirty-four of 52 (65%) patients available for analysis had acute diarrhoea, and 18/52 (35%) had chronic diarrhoea. Twenty-three of 52 (44%) patients had a concurrent gut pathogen. After exclusion of concurrent pathogens enteric viral infections were found to be significantly associated with acute as opposed to chronic diarrhoea (P = 0.004). The presence of adenovirus colitis was significantly more likely to be associated with chronic diarrhoea (15/21 cases) than adenovirus isolated from stool alone (9/23 cases) (P = 0.03). There was a trend towards an association between adenovirus colitis and colonic cytomegalovirus infection (P = 0.06). Conclusion Enteric viral infection is strongly associated with acute diarrhoea in patients with HIV. Light microscopic examination of large bowel biopsies can identify adenovirus colitis which is significantly associated with chronic diarrhoea, and in addition may facilitate gastrointestinal co-infection with CMV.     

Trends in tuberculosis incidence and their determinants in 134?countries

Objective

To determine whether differences in national trends in tuberculosis incidence are attributable to the variable success of control programmes or to biological, social and economic factors.

Methods

We used trends in case notifications as a measure of trends in incidence in 134 countries, from 1997 to 2006, and used regression analysis to explore the associations between these trends and 32 measures covering various aspects of development (1), the economy (6), the population (3), behavioural and biological risk factors (9), health services (6) and tuberculosis (TB) control (7).

Findings

The TB incidence rate changed annually within a range of ±10% over the study period in the 134 countries examined, and its average value declined in 93 countries. The rate was declining more quickly in countries that had a higher human development index, lower child mortality and access to improved sanitation. General development measures were also dominant explanatory variables within regions, though correlation with TB incidence trends varied geographically. The TB incidence rate was falling more quickly in countries with greater health expenditure (situated in central and eastern Europe and the eastern Mediterranean), high-income countries with lower immigration, and countries with lower child mortality and HIV infection rates (located in Latin America and the Caribbean). The intensity of TB control varied widely, and a possible causal link with TB incidence was found only in Latin America and the Caribbean, where the rate of detection of smear-positive cases showed a negative correlation with national incidence trends.

Conclusion

Although TB control programmes have averted millions of deaths, their effects on transmission and incidence rates are not yet widely detectable.     

Malignant biliary obstruction: intracavitary treatment with a high-dose- rate remote afterloading device

A new technique of intracavitary brachytherapy for malignant biliary obstruction is presented. The technique involves the use of a high-dose-rate remote afterloading device, which offers all the advantages of conventional brachytherapy with the added benefit that the dose can be delivered in a single treatment over a few minutes. The potential problems associated with conventional brachytherapy are thereby minimized.