[Development and validation of an individual risk prediction tool for severe respiratory syncytial virus infection among children under five years in China].

Objective: To construct a predictive model to assess the risk of severe respiratory syncytial virus infection among children under five years in China, conduct preliminary validation of this model by using external data, and develop an individual risk assessment tool available for their parents. Methods: The admission after RSV infection was used as a marker of severe infection. Based on the evidence of RSV hospitalization-related risk factors and real-world data, such as the prevalence of various risk factors in children under five years old in China, a Monte Carlo-based individual RSV hospitalization risk prediction model for children under five years old was constructed. Taking Suzhou City as an example, the model was externally validated, and an interactive risk prediction tool (RSV HeaRT) was developed on the WeChat mini-program platform. Results: The estimation model showed that in children under five years old in China if the population did not have any risk factors for severe RSV infection, the RSV annual hospitalization rate was 2.2/1 000 (95%CI: 0.9/1 000-7.5/1 000). Based on this baseline hospitalization rate and the prevalence of related risk factors in Suzhou, the model predicted an RSV hospitalization rate of 8.0/1 000 (95%CI: 4.6/1 000-24.4/1 000) for children under five years old annually in Suzhou, which was close to the reported RSV hospitalization rate in literature (10/1 000-20/1 000). In the developed RSV HeaRT WeChat mini-program, target users (such as parents of children) could input basic information, disease history, and social environmental factors of the child into the mini-program, and the tool could provide real-time feedback on the following predicted results: First, the relative risk of hospitalization due to RSV infection in current children compared to general children; Second, the probability of hospitalization due to RSV infection within the next year; Third, the relative risk of adverse outcomes during hospitalization in the event of RSV infection. Conclusion: This study is based on real-world evidence related to RSV hospitalization risk and constructs an RSV hospitalization risk prediction model suitable for Chinese children based on the combination of the current prevalence of risk factors in children under five years old in China. The accuracy of the prediction model results has been preliminarily demonstrated. Based on this design, the RSV HeaRT developed can facilitate parents to evaluate the hospitalization risk of children.

[Establishment of a nomogram for predicting the high frequency hearing loss of workers exposed to noise].

Objective: To explore the related influencing factors of high frequency hearing loss (HFHL) in workers exposed to noise and establish a prediction nomogram for HFHL. Methods: A total of 822 workers exposed to noise from 46 enterprises were included. A questionnaire survey and a pure-tone hearing test were conducted for the workers. The data of noise level of the workers exposed was also collected. After single factor analysis of related influencing factors, the multivariate Logistic regression analysis was performed to identify the final independent influencing factors of HFHL. Finally, a nomogram model was established by R software to achieve individual prediction of HFHL. Results: Among the 822 workers exposed to noise, 166 (20.2%) workers had HFHL. In multivariate Logistic regression analysis, increasing age, men, increasing wearing earphone time, less wearing earplugs, and high noise level were the independent risk factors for HFHL. The C-index of the nomogram model for predicting HFHL was 0.834 (95%CI: 0.748~0.903) . The area under the predictive power curve of nomogram model was 0.834 (95%CI: 0.799~0.869, P<0.001) . Conclusion: Age, sex, wearing earphone time, wearing earplugs, and noise level are independent influence factors for HFHL. The nomogram model is successfully established as a accurate and visible tool for individually predicting the HFHL risk in workers exposed to noise.

Quantum size effect on surface photovoltage spectra: alpha-Fe(2)O(3) nanocrystals on the surface of monodispersed silica microsphere.

A new method for the preparation of Fe(2)O(3) nanoparticle/SiO(2) microsphere composites is described, in which fine alpha-Fe(2)O(3) nanocrystals were prepared by forced hydrolysis of FeCl(3) aqueous solution. The structure and optical spectra of these alpha-Fe(2)O(3) nanocrystals have been studied. Their visible optical absorption can be enhanced by their adsorptions on the surface of SiO(2) microspheres and thereafter simple packing of these microspheres to the aggregated structures. The size-dependent photogenerated surface photovoltage spectra (SPS) of these composites were studied, and quantum confinement effects of the SPS properties were observed. The transport of photoinduced charges between nanocrystals with intrinsic electronic nature of confined states accounts for this phenomenon. These results are helpful in understanding the relationship among d-d transition and charge-transfer transition in transition metal oxides and find applications in photovoltaic devices.

Colonic variceal bleeding in a patient with mesenteric venous obstruction due to an ileal carcinoid tumour.

Colonic varices are a recognized cause of rectal bleeding in portal hypertension. We report here a patient who presented with melaena several months after resection of an ileal carcinoid tumour. Subsequent colonoscopy for continued episodes of rectal bleeding demonstrated extensive colonic varices. In the absence of portal hypertension, the varices appeared to be related to mesenteric venous obstruction. The management of bleeding colonic varices, in these circumstances, is discussed.

Management of protozoal diarrhoea in HIV disease.

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.

Alterations in blood leucocyte adhesion molecule profiles in HIV-1 infection.

CD4 and CD8 lymphocyte numbers in the gut lamina propria are grossly altered in HIV-1 infection, out of proportion to alterations in the circulation. Such alterations in lymphocyte counts in the tissues may be due to altered leucocyte migration from the blood. One factor affecting leucocyte migration is adhesion molecule expression. Levels of adhesion molecule expression on peripheral CD4 and CD8 lymphocytes, monocytes and neutrophils from HIV-1-infected (AIDS and non-AIDS) and low-risk control individuals were compared. CD11a, CD62L, CD44, CD49d and beta7 integrin expression were examined by FACS analysis of fresh whole blood. Significant alterations in adhesion molecule expression were detected in HIV infection. The most striking alterations were observed in the CD8 lymphocyte population. CD11a expression was increased and CD62L and CD44 decreased. The CD4 lymphocyte population followed a similar, though less striking, pattern of alteration in adhesion molecule expression. Neutrophils displayed significantly reduced expression of both CD11a and CD62L, but only after onset of AIDS. Monocytes from infected individuals without AIDS displayed a different pattern of altered adhesion molecule expression compared with individuals with AIDS. These findings suggest that in HIV infection, leucocyte functions, such as migration, which require adhesion molecules are abnormal.

A prospective single centre study comparing computed tomography pneumocolon against colonoscopy in the detection of colorectal neoplasms.

BACKGROUND AND AIMS: To determine the sensitivity and specificity of computed tomography (CT) pneumocolon in the detection of colorectal neoplasms. METHODS: A total of 201 consecutive patients with colorectal symptoms or requiring surveillance for colorectal neoplasms underwent both conventional colonoscopy and CT pneumocolon. RESULTS: On conventional colonoscopy 13 invasive colorectal carcinomas were detected in 13 patients, and 118 polyps in 63 patients (14 polyps were > or =1 cm in diameter, 25 were 6-9 mm, and 79 were < or =5 mm). CT pneumocolon detected all 13 cancers, two false positive cancers, but only 20 polyps (seven were > or =1 cm). This resulted in a sensitivity of 100% (95% confidence interval (CI) 87-100%) and specificity of 99% (95% CI 97-100%) for detection of invasive carcinoma, and a sensitivity of 73% (95% CI 56-90%) and specificity of 94% (95% CI 91-98%) for detection of invasive carcinoma and/or > or =1 cm polyps. CT pneumocolon also identified invasive carcinoma not seen at colonoscopy because of incomplete examination in three patients, and detected metastases in six colorectal carcinoma patients and extracolonic carcinoma in a further seven patients. CONCLUSIONS: CT pneumocolon had a high sensitivity and specificity for detection of invasive colorectal carcinoma but not colorectal polyps. CT pneumocolon may be suitable for initial investigation of patients with symptoms of colorectal malignancy.

Eradication of cryptosporidia and microsporidia following successful antiretroviral therapy.

OBJECTIVES: Incidence of opportunistic protozoal infections causing diarrheal illnesses in patients with HIV has decreased since the introduction of highly active antiretroviral therapy (HAART). The objective of this study was to determine whether the parasites, cryptosporidia, and microsporidia were effectively eradicated or only suppressed following treatment. DESIGN: Six HIV-positive patients with diarrheal symptoms caused by cryptosporidia or microsporidia were prospectively followed up with stool samples and duodenal biopsies. Samples were taken before HAART, between 1 to 3 months, and 6 months post-HAART. METHODS: Duodenal samples were analyzed using routine histology and transmission electron microscopy. Stool samples were analyzed by both light microscopy and polymerase chain reaction (PCR) techniques. RESULTS: Patients who responded successfully to HAART eradicated both cryptosporidial and microsporidial organisms. Symptoms improved within 1 month of therapy but complete eradication of the organisms was only observed after 6 months of treatment. CONCLUSIONS: AIDs-related cryptosporidiosis and microsporidiosis can be cured following successful antiretroviral therapy.

Ultrasound and magnetic resonance imaging assessmentof active bowel segments in Crohn's disease.

AIM: Determining bowel disease activity in Crohn's patients can be difficult on clinical and laboratory assessment. Endoscopy is invasive and barium studies use ionising radiation. The aim of this study was to compare ultrasound and magnetic resonance imaging (MRI) in detecting Crohn's disease activity in the small or large bowel. MATERIALS AND METHODS: Thirty patients, previously diagnosed with Crohn's disease, had bowel ultrasound and MR imaging, and were deemed active or inactive on each test. The 'gold standard' was based on clinical assessment and one or more of the following: endoscopy, barium studies or surgery. RESULTS: For determining Crohn's disease activity, the sensitivities and specificities of bowel ultrasound and MRI were 87 percent and 100 percent, and 87 percent and 71 percent, respectively. Significant parameters that defined disease activity were bowel wall thickening on ultrasound and MRI, and contrast enhancement of the bowel wall and mesenteric vascularity/stranding on MRI. CONCLUSION: Ultrasound and MRI were both sensitive for determining Crohn's disease activity in the bowel, but MRI with gadolinium enhancement was less specific.