Blockade of Plasmodium falciparum erythrocyte invasion: New assessment of anti-Plasmodium falciparum reticulocyte-binding protein homolog 5 antibodies.

There is great interest in any new discoveries in malaria vaccine research. Plasmodium falciparum reticulocyte-binding protein homolog 5 (PfRH5) shows promise in this area and may be used together with other merozoite antigens as a potential vaccine. In the present study, a bioinformatics prediction approach was applied to a PfRH5 B-cell epitope, and two B-cell epitope distributions were selected. Antibodies against the two PfRH5 distributions were obtained and the growth activity inhibition was measured. No inhibition of the P. falciparum CY strain was found, but the growth of the P. falciparum 3D7 strain was inhibited by all of the antibodies, in contrast to the results of other studies. It was additionally found that certain quantities of protein led to the inhibition of the parasitic invasion. Equally noteworthy was that the survival time of the group immunized with a portion of PfRH5 was significantly longer than that of the group immunized with the full-length protein, following infection by P. berghei ANKA. The present study produced conflicting results in in vitro and in vivo experiments, although the accuracy of the evaluation may be lessened due to the use of a murine malaria model. The findings of the present study may indicate that PfRH5 may not be suitable in malaria vaccine research.

Effects of CD3McAb and rhIL-2 activated bone marrow on the killing and purging of leukemia cells.

We investigated the roles of CD3McAb and rhIL-2 activated bone marrow in the killing and purging of leukemia cells. Cytotoxicity of activated bone marrow was detected with MTT assay. CFU-GM level in activated bone marrow and the destruction of leukemia cells were measured using the semi-solid cell culture. Immune activation markers in activated bone marrow were detected by indirect immunofluorescence assay. Bone marrow activated by CD3McAb and rhIL-2 displayed significantly upregulated the killing and purging abilities on the leukemia cell line K562 and HL-60. Such effects were superior to that of bone marrow activated by rhIL-2 or CD3McAb alone (P < 0.05, P < 0.01). Activation by rhIL-2 and (or) CD3McAb exerted no obvious influence on CFU-GM level in bone marrow. Compared with bone marrow activated by rhIL-2 or CD3McAb alone, the synergistic effect of both CD3McAb+ and hIL-2 caused significant increase of CD3(+), CD8(+), CD19(+), CD25(+), CD38(+), and CD56(+) levels. Our study indicates that CD3McAb enhanced the killing and purging effects of rhIL-2 activated bone marrow on leukemia cells.

Confocal laser endomicroscopy for superficial esophageal squamous cell carcinoma.

BACKGROUND AND STUDY AIMS: Confocal laser endomicroscopy (CLE) allows subsurface imaging of gastrointestinal mucosa in vivo. The goal of the present study was to compare the endomicroscopic characteristics of cells and intrapapillary capillary loops (IPCLs) in normal and superficial esophageal squamous cell carcinoma (SESC). PATIENTS AND METHODS: We recruited consecutive patients with SESC diagnosed by conventional endoscopy and confirmed by histopathology between July 2006 and May 2008. The confocal endoscopic images of these patients were collected and compared with the corresponding histology. The characteristic patterns of cells and IPCLs was then analyzed from these images of malignant and normal mucosa. The quality of images and interobserver variations of two endoscopists were also evaluated. RESULTS: Overall, 64 samples from 57 subjects (27 SESCs, 30 controls) were examined by CLE. The confocal images corresponded to the hematoxylin and eosin staining from the same sites. The confocal images showed that there was a significantly higher proportion of squamous epithelial cells with irregular arrangement (79.4 % vs. 10.0 %, P < 0.001), increased diameter of IPCLs (26.0 microm vs. 19.2 microm, P < 0.001), and irregular shape IPCLs (82.4 % vs. 36.7 %, P = 0.0002) in the SESC group compared with the controls. Massive IPCLs with tortuous vessels (44.1 % vs. 0 %, P < 0.0001), and long branching IPCLs (23.5 % vs. 3.3 %, P = 0.0204) were frequently observed in the SESC group. In this study, about 35.5 % of images were graded as good quality, and the interobserver agreement for the prediction of cancerous mucosa was graded as substantial. CONCLUSIONS: CLE can be used to distinguish cancerous from normal epithelium, which gives it potential value for early detection of esophageal carcinoma. The difficulty in obtaining good images in the esophagus by CLE is a latent problem.

Diagnosis of gastric intestinal metaplasia with confocal laser endomicroscopy in vivo: a prospective study.

BACKGROUND AND STUDY AIMS: Gastric intestinal metaplasia (GIM) is a risk factor for development of intestinal-type gastric cancer. We aimed to assess the usefulness of confocal laser endomicroscopy (CLE) in diagnosing GIM. PATIENTS AND METHODS: 28 patients with known GIM underwent CLE, and CLE criteria for diagnosis of GIM were developed. In addition, 53 consecutive patients with known or suspected GIM were prospectively evaluated. RESULTS: GIM was identified if any of the following three features were present in an image field: goblet cells, columnar absorptive cells and brush border, and villiform foveolar epithelium. GIM was then classified as complete or incomplete according to the shape of the goblet cells, the presence of absorptive cells or brush border, and the architecture of vessels and crypts. In a prospective study, a total of 13 670 CLE images were obtained. Among 267 sites from 53 patients, 160 from 36 patients were diagnosed histopathologically as GIM. The sensitivities of conventional endoscopy and CLE for GIM were 36.88 % vs. 98.13 %, and the specificities were 91.59 % vs. 95.33 %, respectively. The kappa value for the correlation with histological findings was 0.25 for conventional endoscopy vs. 0.94 for CLE. The sensitivity and specificity of CLE were 68.03 % and 89.66 %, respectively, for the diagnosis of complete GIM, and 68.42 % and 83.41 %, respectively, for incomplete GIM; the kappa value for the correspondence between CLE and histological findings was 0.67. CONCLUSION: CLE is a useful and potentially important method for the diagnosis and classification of GIM in vivo.