Infant parasite rates and immunoglobulin M seroprevalence as a measure of exposure to Plasmodium falciparum during a randomized controlled trial of insecticide-treated bed nets on the Kenyan coast

Repeated cross-sectional surveys among infants sleeping under insecticide-treated bed nets (ITBN) and contemporary control infants were used to estimate changes in Plasmodium falciparum exposure due to ITBN use on the Kenyan coast. Presence of P. falciparum parasites or total P. falciparum Immunoglobulin M (IgM) seropositivity were used independently and in combination in a constant risk catalytic conversion model to estimate the force of infection in ITBN and control communities. Such studies during infancy avoid problems of early saturation of prevalence due to high forces of infection and persistence of infection, minimize problems of self-treatment, and can be conducted among large populations covering a wide geographic area. These contrast previous parasitologic studies of ITBN among older children and the traditional entomologic studies of transmission that are logistically demanding. Our investigations demonstrated that parasite prevalence, IgM seropositivity, and the force of transmission were all significantly reduced by 50%. In addition, more infants under ITBN entered their second year of life without previous exposure to P. falciparum than control infants. These effects upon delayed acquisition of effective immunity require careful monitoring during future vector control programs using ITBN.     

基于多重绘制模型的艺术绘制

为了使得计算机能自动生成表达力丰富的三维场景的艺术绘制，提出了一种基于Shader的多重绘制模型，并采用了多重绘制的协调、参数空间的纹理铺陈、基于色调的表现控制等技术来进行模拟．引入多重绘制可以同时采用对象空间的绘制和图像空间的绘制，通过纹理铺陈描述语言Shader，用户可以定义自己的纹理和笔划来表现三维和二维场景．不同于传统的Shader，基于Shader的多重绘制模型采用光亮度、材质颜色等作为输入，由用户自行决定绘制结果的输入．这一用户可定制性的引入大大增强了艺术绘制的表现能力．该模型已经在一个建筑设计系统中得到实现，以钢笔画为表现媒介的图例表明该模型模拟效果令人满意．     

Bacterial adhesion to bisphosphonate coated hydroxyapatite

Staphylococcus aureus (S. aureus) is commonly associated with microbial infection of orthopaedic implants. Such infections often lead to osteomyelitis, which may result in failure of the implant due to localised bone destruction. Bacterial adhesion and subsequent colonisation of the device may occur as a consequence of contamination during surgery, or by seeding from a distant site through the blood circulation. Coating of the hydroxyapatite (HA) ceramic component of artificial hip joints with the bisphosphonates clodronate (C) and pamidronate (P) has been proposed as a means to minimise osteolysis and thereby prevent loosening of the implant. However, the effect of the bisphosphonate coating on bacterial adhesion to the HA materials must be determined before this approach can be implemented. In this study coated HA materials were incubated with the S. aureus and the number of adherent bacteria determined using the Modified Vortex Device (MVD) method. The number of bacteria adherent to the P coated HA material was significantly greater than that adherent to uncoated HA (60-fold increase) or to the C coated HA (90-fold increase). Therefore, even though earlier studies suggested that P bound to HA may improve osseointegration, the results presented would suggest that the use of this coating may be limited by the potential increased susceptibility of the coated device to infection.     

Clinical results of meniscus repair in patients 40 years and older

The critical role that the meniscus plays in the knee along with the advantages of preserving as much of the meniscus as possible have both been well documented. Whenever possible, meniscus repair has become the procedure of choice for treatment of meniscal tears. However, some researchers have reported less favorable results in older patients. To determine the results of meniscus repair in older patients, patients 40 years and older who underwent arthroscopically assisted meniscus repair were prospectively followed up. Thirty-seven patients were included in the study, all of which had a minimum 2-year follow-up (average, 26.5 months). The average age of the patients at the time of the repair was 44.2 years (range, 40 to 52 years); 26 were males and 11 were females. There were 19 left knees and 18 right knees included in the study. Twenty-two patients had associated anterior cruciate ligament reconstructions. Physical examination at follow-up included swelling, joint line tenderness, locking, and McMurray testing and radiographs. Five of 37 menisci repaired (13.5%) were symptomatic at latest follow-up. All of these patients had joint line tenderness and two had a positive McMurray test. Three of these patients had repeat arthroscopy confirming that the meniscus had not healed. Because of the small number of patients with symptoms at follow-up, the authors feel that meniscus repair in patients 40 years and older is an effective treatment for peripherally located meniscus tears. With 86.5% of the patients having good clinical results, these findings are comparable with other studies with a younger population and signify that repair of peripheral tears is indicated in this age group especially in conjunction with anterior cruciate ligament reconstruction. The findings suggest that the location and meniscal tear, rather than the age of the patient, determine the potential for successful repair.     

Function-sparing surgery for desmoid tumors and other low-grade fibrosarcomas involving the brachial plexus

OBJECTIVE: Low-grade fibrosarcomas and desmoid tumors present a surgical challenge in that they have a strong tendency for local invasion, surgical margins are poorly delineated, and complete resections are difficult. Nowhere is this more evident than in those lesions involving the brachial plexus. We review our experience with these difficult lesions. METHODS: From a prospective database of 2900 patients admitted for treatment of sarcoma between 1982 and 1996, we identified 15 patients with involvement of the brachial plexus by a low-grade fibrosarcoma or desmoid tumor. All patients underwent resection, with 13 of 15 receiving adjuvant radiotherapy. The 15 patients had a mean age at initial operation of 47 years. The male-to-female ratio was 8:7. The mean follow-up period was 65 months (median, 53 mo). RESULTS: Gross total resection was achieved in 12 patients (80%), although 11 of these patients had positive surgical margins. Overall, 64% of the tumors have recurred locally. There were no distant metastases, and no patients died as a result of their disease. One patient died as a result of unrelated cancer. An assessment of the functional outcomes revealed seven patients with normal function or mild neurological deficits and eight who were suffering from significant weakness, debilitation, or chronic pain. One patient required forequarter amputation. CONCLUSION: Surgical resection plus postoperative radiotherapy is the treatment of choice for low-grade fibrosarcomas and desmoid tumors involving the brachial plexus. However, aggressive surgical management with the goal of achieving a gross total resection with negative histological margins can produce unnecessary morbidity. Preserving function should be a primary goal of the operations, although this will be associated with residual disease and will risk local recurrence but rarely death resulting from the disease.     

Sonographic borderlands in the fetal abdomen

Ultrasonographic examination of the fetal abdomen is an integral part in all routine fetal sonograms and can provide significant information about the status and prognosis of the fetus. Although many types of fetal anomalies can be identified (i.e., gastroschisis, omphalocele, or congenital diaphragmatic hernia), there are several sonographic findings that are not clearly anomalous, but may be associated with poor fetal outcome. Echogenic fetal bowel, small or absent fetal stomach and fetal intra-abdominal calcifications all fall into this category. This article reviews the recent literature as it relates to these topics, including suggestions regarding the need for further action, and the types of further actions that are available to help identify abnormal fetuses and prevent unnecessary and/or invasive testing of normal ones.     

p53 and thymidylate synthase expression in untreated stage II colon cancer: associations with recurrence, survival, and site

We initiated a retrospective study to determine whether p53 status and thymidylate synthase (TS) protein expression in primary colon tumors influence recurrence and survival for patients with stage II colon cancer. Tumor specimens from 45 consecutive untreated patients with stage II colon cancer were examined for p53 and TS protein expression using immunohistochemistry. The median follow-up was 5.1 years. Eighteen patients had left-sided tumors, and 27 had right-sided tumors. Fourteen of 45 patients (31%) developed recurrence. p53 overexpression was detected in the tumors of 18 patients (40%); 10 patients (55%) with p53 overexpression recurred; and 4 of 27 (15%) without evidence of p53 overexpression recurred (P = 0.002). High TS expression was detected in the tumors of 16 patients (36%): 8 patients (50%) with high TS expression recurred, and 6 patients (21%) with low TS expression recurred (P = 0.027). Patients with p53 overexpression had a significantly poorer survival than did those patients without p53 overexpression (P < 0.001). High TS expression was associated with poor survival (P = 0.004). p53 overexpression and high TS expression were significantly associated with left-sided tumors (P = 0.003 and P = 0.022). Thirteen of 16 patients (81%) with high TS expression also overexpressed p53, and 24 of 29 patients (81%) with low TS expression did not manifest p53 overexpression (P < 0.001). p53 and TS expression in primary stage II colon cancer are associated and appear to influence recurrence and survival. In this pilot study, left-sided tumors demonstrate significantly more p53 overexpression and significantly higher TS expression than do right-sided tumors, which may explain the significantly poorer survival for patients with left-sided tumors.     

A functional analysis of the role of IGF2 in IDDM2-encoded susceptibility to type 1 diabetes

OBJECTIVE: The association of antioxidant nutrients and risk of nuclear opacification was evaluated in the Longitudinal Study of Cataract. DESIGN: Nutritional data were collected at baseline on the 764 participants, which included assessment of dietary intake, use of vitamin supplements, and plasma levels of vitamin E. Ophthalmologic and other data were collected at baseline and at yearly follow-up visits, including lens photographs, which were graded using the Lens Opacities Classification System III protocol. MAIN OUTCOME MEASURES: Analyses examined whether the nutritional factors at baseline were related to increases in nuclear opacification at follow-up. The MULCOX2 approach, an extension of the Cox regression model, was used. Results are presented as relative risks (RRs) and 95% confidence intervals. INTERVENTION: Intervention was not applicable. RESULTS: The risk of nuclear opacification at follow-up was decreased in regular users of multivitamin supplements (RR = 0.69; 0.48-0.99), vitamin E supplements (RR = 0.43; 0.19-0.99), and in persons with higher plasma levels of vitamin E (RR = 0.58; 0.36-0.94). CONCLUSIONS: In regular users of multivitamin supplements, the risk of nuclear opacification was reduced by one third; in regular users of vitamin E supplements and persons with higher plasma levels of vitamin E, the risk was reduced by approximately half. These results are similar to those obtained in our earlier case-control study. Because these data are based on observational studies only, the results are suggestive but inconclusive. The possible effect of nutritional supplements on the lens requires confirmation by ongoing clinical trials.     

Prognostic markers in pheochromocytoma

Annexin II (AII) belongs to a family of glycoproteins that bind negatively charged phospholipids in the presence of calcium. The annexins exert various biological functions. We have previously shown that soluble AII suppresses mitogen-induced lymphoproliferation in vitro. In this study we address the question of whether soluble AII may also affect immunoglobulin secretion. Mononuclear cells from peripheral blood were stimulated with pokeweed mitogen in vitro and immunoglobulin-secreting cells were quantified using an ELISPOT assay. Retroplacental serum and soluble AII significantly inhibited secretion of IgG and IgM when added at concentrations that did not affect lymphoproliferation or cell viability. The inhibitory effect was dose- and time dependent. Significant suppression was observed when soluble AII was added at concentrations of 0.1 and 0.01 microg/ml. The strongest inhibition was observed when soluble AII or retroplacental serum was added initially. The data demonstrate that soluble AII can suppress immunoglobulin secretion in vitro. AII seems to be a potent immunosuppressive substance. The presence of high levels of soluble AII in retroplacental serum may indicate a possible immunomodulatory role in normal pregnancy.     

Characterization and screening for mutations of the growth arrest-specific 11 (GAS11) and C16orf3 genes at 16q24.3 in breast cancer

BACKGROUND: Both fibroblast-mediated cytokine gene therapy and bone marrow transplantation (BMT) have proven to be efficient protocols for the recovery of bone marrow depression. In this report, the effects of fibroblast-mediated interleukin (IL)-6 gene therapy, in combination with BMT, on the recovery of irradiation-induced bone marrow depression were investigated. METHODS: NIH3T3 fibroblast cells engineered to secrete IL-6 (NIH3T3-IL-6) or NIH3T3 cells transduced with the neomycin gene (NIH3T3-Neo), in combination with 10(7), 10(6), or 10(5) syngeneic bone marrow cells, were implanted into irradiated mice. RESULTS: The platelets and white blood cells in the peripheral blood of the irradiated mice increased greatly 12 days after implantation of NIH3T3-IL-6 cells and BMT, the white blood cell counts were restored to a normal level 32 days after the combined therapy, and the platelet number was obviously higher than that in mice implanted with NIH3T3-Neo and BMT. Twenty and 25 days after the combined therapy, the mice showed accelerated recovery of colony-forming unit (CFU)-granulocyte/macrophages and CFU-megakaryocytes when compared with the mice implanted with NIH3T3-Neo cells and BMT. Ten days after lethal irradiation with gamma rays, the spleens formed more CFU-spleen in mice implanted with NIH3T3-IL-6 cells and BMT than in mice injected with phosphate-buffered saline or NIH3T3-Neo cells. Combined therapy with NIH3T3-IL-6 cell implantation and BMT delayed the survival period of the hematopoietic-depressed mice significantly when compared with therapy with NIH3T3-Neo cell implantation and BMT. CONCLUSIONS: These data demonstrated that the combined therapy of fibroblast-mediated IL-6 gene therapy and BMT could significantly promote the recovery of irradiation-induced hematopoietic depression.