伴随结节性硬化的浸润性视网膜星形细胞瘤4例

众所周知，视网膜星形细胞瘤常伴有结节性硬化的表现。视网膜星形细胞瘤一般是发生在视网膜神经纤维层的无蒂轻度隆起性病变。临床上可以是单侧发生，也可以是双侧发生。可以单个病灶，也可以多个病灶。可以是透明的，也可以是不透明的。可以有钙化，也可以没有钙化。视网膜星形细胞瘤相对固定的伴有眼内结节性硬化，很少表现为浸润性增长。在很少的情况下视网膜星形细胞瘤可以表现出浸润性增长，造成局部严重并发症。     

Oilseed rape and seasonal symptoms: epidemiological and environmental studies.

BACKGROUND--There is widespread concern that the cultivation of oilseed rape leads to seasonal epidemics of respiratory symptoms in populations living in the neighbourhood, and it has been suggested that the plant is a potent allergen. A study was therefore undertaken to determine the prevalence of seasonal symptoms in rural populations close to and far from areas of oilseed rape cultivation, and to measure the levels of allergen and other potentially harmful substances released by the crop. METHODS--Random samples of 1000 adults from the general practice populations of two villages surrounded by oilseed rape fields, and 1000 adults from one village far from such cultivation, were taken. The subjects completed a previously validated questionnaire on respiratory and other symptoms, including questions on symptom seasonality, occupation, and smoking habits. Pollen and fungal spore counts were made around fields of oilseed rape and in the villages. The chemicals released by oilseed rape were measured in the field. RESULTS--Overall, 86.8% of the subjects completed the questionnaires and the populations of the two samples were generally comparable. Spring and summer exacerbations of symptoms occurred equally in the two areas in approximately 25% of the population. There were small but significant excesses of cough, wheeze, and headaches in spring in the oilseed rape area (2.3% v 1.1%, 6.8% v 4.6%, and 4.8% v 2.8%, respectively), and cough, wheeze, and itchy skin were more prevalent in smokers. Counts of oilseed rape pollen were generally low except adjacent to fields, and counts of fungal spores were mostly higher in the rape than the non-rape areas. Oilseed rape was shown to give off terpenes and these were detected close to fields. CONCLUSIONS--While it is likely that a proportion of the spring symptoms occurring in people living in close proximity to oilseed rape is caused by the plant, the excess of such symptoms is small. This, together with the low levels of pollen in the area, suggests that allergy to oilseed rape pollen is uncommon. The general prevalence of seasonal symptoms in rural areas is of interest, and a proportion of these cases is likely to be caused by factors other than allergy. Release of chemicals by plants and natural rises in summer ozone levels may be contributors.     

Chemotherapy for Chagas' disease: a perspective of current therapy and considerations for future research

Our current knowledge of the biology of Trypanosoma cruzi and its relation to the development of chemotherapy for Chagas' disease are reviewed. This includes recent developments in the understanding of kinetoplast DNA and glycosomes; the action of oxygen radicals; intermediary metabolism of purines, pyrimidines, and folic acid; and the formation of microtubules. At this time, these organelles and metabolic pathways appear to be the most promising for potential exploitation for chemotherapeutic purposes. Compounds of current experimental interest also are discussed. These are agents that have shown promise in the laboratory and for which data exist regarding probable mechanisms of action. The activities of these agents correlated, in so far as is possible, with those structures or metabolic pathways in the trypanonsome that are affected by their actions. The compounds are of two general groups: nitro compounds and purine analogues.     

Intercellular adhesion molecule‐1 gene polymorphisms in Behçet’s disease

Intercellular adhesion molecule‐1 (ICAM‐1) gene polymorphisms have been implicated in the susceptibility to inflammatory diseases, including multiple sclerosis and inflammatory bowel disease. The expression of both soluble and tissue ICAM‐1 is increased in Behçet’s disease (BD) but the contribution of ICAM‐1 gene polymorphisms to this disease remains unknown. Associations with BD have been reported for genes within the MHC, including HLA‐B51, TNF and MICA, but the role of non‐MHC genes in BD remains largely unexplored. We have investigated the frequency of the R/G 241 and K/E 469 ICAM‐1 gene polymorphisms in 83 patients with BD disease and 103 healthy controls, all of Palestinian and Jordanian descent, and demonstrated an association between BD and the ICAM‐1 E469 allele (P_c = 0.046, OR = 2.1). Among patients, no association was found between the presence of ocular disease and ICAM‐1 polymorphisms. While the functional correlate of this polymorphism remains unclear, this finding indicates that a genetic polymorphism in the ICAM‐1 gene domain, which is independent of the MHC, may contribute to disease.     

Genetic diversity among clinical isolates of Acremonium strictum determined during an investigation of a fatal mycosis

Primarily saprophytic in nature, fungi of the genus Acremonium are a well-documented cause of mycetoma and other focal diseases. More recently, a number of Acremonium spp. have been implicated in invasive infections in the setting of severe immunosuppression. During the course of routine microbiological studies involving a case of fatal mycosis in a nonmyeloablative hematopoietic stem cell transplant patient, we identified a greater-than-expected variation among strains previously identified as Acremonium strictum by clinical microbiologists. Using DNA sequence analysis of the ribosomal DNA intergenic transcribed spacer (ITS) regions and the D1-D2 variable domain of the 28S ribosomal DNA gene (28S), the case isolate and four other clinical isolates phenotypically identified as A. strictum were found to have <99% homology to the A. strictum type strain, CBS 346.70, at the ITS and 28S loci, while a sixth isolate phenotypically identified only as Acremonium sp. had >99% homology to the type strain at both loci. These results suggest that five out of the six clinical isolates belong to species other than A. strictum or that the A. strictum taxon is genetically diverse. Based upon these sequence data, the clinical isolates were placed into three genogroups.     

Detection of pneumococci in respiratory secretions: clinical evaluation of gentamicin blood agar.

The use of sheep blood agar containing 5 microng of gentamicin per ml has been suggested as a means of selectively isolating Streptococcus pneumoniae from respiratory secretions. We have tested this method, in parallel with standard methods, on 844 respiratory specimens in a clinical laboratory and have confirmed that the yield of pneumococci can be increased approximately 40% by using agar containing gentamicin. However, since the antibiotic suppresses the growth of staphylococci, group A streptococci, and gram-negative bacilli, gentamicin agar cannot be used as a replacement for the standard method. The requirement for duplicate plating raises the cost per additional pneumococcal isolate to prohibitive amounts. Although the method is useful in studies designed to isolate only pneumococci, it cannot be recommended for the routine clinical laboratory. An unanticipated observation from our study is that the yield of pneumococci in respiratory secretions can be increased 10-fold simply by screening sputum for the presence of leukocytes using the Gram stain. This is in agreement with results reported from other laboratories.     

Transfer of Tumor Necrosis Factor-α to Rat Lung Induces Severe Pulmonary Inflammation and Patchy Interstitial Fibrogenesis with Induction of Transforming Growth Factor-β1 and Myofibroblasts

Tumor necrosis factor-α is up-regulated in a variety of different human immune-inflammatory and fibrotic pulmonary pathologies. However, its precise role in these pathologies and, in particular, the mechanism(s) by which it may induce fibrogenesis are not yet elucidated. Using a replication-deficient adenovirus to transfer the cDNA of tumor necrosis factor-α to rat lung, we have been able to study the effect of transient but prolonged (7 to 10 days) overexpression of tumor necrosis factor-α in normal adult pulmonary tissue. We have demonstrated that local overexpression resulted in severe pulmonary inflammation with significant increases in neutrophils, macrophages, and lymphocytes and, to a lesser extent, eosinophils, with a peak at day 7. By day 14, the inflammatory cell accumulation had declined, and fibrogenesis became evident, with fibroblast accumulation and deposition of extracellular matrix proteins. Fibrotic changes were patchy but persisted to beyond day 64. To elucidate the mechanism underlying this fibrogenesis, we examined bronchoalveolar fluids for the presence of the fibrogenic cytokine transforming growth factor-β1 and tissues for induction of α-smooth muscle actin-rich myofibroblasts. Transforming growth factor-β1 was transiently elevated from day 7 (peak at day 14) immediately preceding the onset of fibrogenesis. Furthermore, there was a striking accumulation of myofibroblasts from day 7, with the most extensive and intense immunostaining at day 14, ie, coincident with the up-regulation of transforming growth factor-β1 and onset of fibrogenesis. Thus, we have provided a model of tumor necrosis factor-α-mediated pulmonary inflammation and fibrosis in normal adult lung, and we suggest that the fibrogenesis may be mediated by the secondary up-regulation of transforming growth factor-β1 and induction of pulmonary myofibroblasts.     

Use of the PATH Alliance database to measure adherence to IDSA guidelines for the therapy of candidemia

Candidemia is an increasing complication of the care of complex patients. Adherence to Infectious Diseases Society of America (IDSA) guidelines for the treatment of candidemia was investigated to assess the impact of compliance on outcomes of therapy. Data on the epidemiology, diagnosis, and treatment of patients with invasive fungal infections (IFIs) was extracted from the PATH Alliance registry, a prospective, multicenter, observational database of invasive fungal infections. Patients with proven candidemia were evaluated for adherence to the IDSA guidelines in terms of choice, dosage, and duration of antifungal therapy. Removal of central venous catheters and time to treatment initiation were assessed. Four-week survival data were compared. Of the 418 patients with candidemia who were included in the study, 361 patients with the necessary data sets were identified, of whom 262 (72.6%) were treated within the IDSA guidelines for the treatment of candidemia (IDSA group); the remaining 99 (27.4%) patients received treatment different from the guidelines (non-IDSA group). Kaplan-Meier (KM) survival analysis for patients in the IDSA and non-IDSA group showed mortality rates of 21.9 and 13.6%, respectively; the difference between the two groups was not statistically significant (P = 0.093). Following the exclusion of patients requiring mechanical ventilation or acute cardiac support, the modified survival KM curves were similar between the two groups. Significantly more patients in the IDSA group required mechanical ventilation and tunneled central catheters, had a concomitant IFI, and received caspofungin. The duration of treatment and inappropriate dosing did not appear to have had a significant impact on survival. Most of the deviations from IDSA guidelines were due to the inappropriate duration and dosing of therapy. No significant difference in mortality was noted between the IDSA and non-IDSA groups. The basis of these differences merit further study. Presented in part at the 44th Annual Meeting of Infectious Disease Society of America, Toronto, Canada, 2006.