Indirect fluorescent antibody test (IFAT) using frozen sections of Brugia malayi adult worms as antigen was employed in the diagnosis and epidemiological investigation of human filariasis. Sera were collected from 704 cases with bancroftian or malayan microfilaremia. the positive rate was 92.8-99.1%. Of 150 healthy people from non-endemic areas, only one showed a positive reaction (false positive rate 0.7%) (Table 1). This technique proved to be highly sensitive and specific for the diagnosis of filariasis and the antigen is easy to prepare. It might be used in sero-epidemiological investigation for the assessment of filariasis control.

Objective To detect brain structural difference between children with unexplained mental retardation and children with typically normal development. Methods The high-resolution magnetic MR imaging were obtained from 21 children with unexplained mental retardation and 30 age-matched control children without intellectual disabilities. Voxel-based morphometry analysis with an optimization of spatial segmentation and normalization procedures were applied to compare differences of gray matter volume between the two groups. The total and regional gray matter volume were compared between the two groups with independent t test. Meanwhile, correlation was conducted to analyze the relationship between the total gray matter volume and intelligence quotient (IQ) with partial correlation test. Results The total gray matter volume was significantly increased in the mental retardation children [(1. 012 ±0. 079) × 106 mm3]in relative to the controls [(0. 956 ± 0. 059) × 106 mm3, t = - 2. 80, P ＜ 0. 05]. Compared to controls,children with unexplained mental retardation showed significantly increased gray matter volume in different regions, including the bilateral thalami, the bilateral superior frontal gyri, the bilateral gyri rectus, the bilateral temporal poles, the right inferior frontal gyrus, right parahippocampal gyrus and the right cerebellum. No correlation was detected between the total gray matter volume and IQ in children with mental retardation (r = 0. 078 ,P ＞ 0. 05). Conclusions VBM would detect the gray matter abnormalities that were not founded in routine MR scanning. The increase of gray matter volume in the frontal-thalamus network might indicate the delayed maturation of the brain development. This might be one of the causations of mental retardation in children.

Objective To detect the differences of grey matter volume between the patients with mental retardation (MR) presented clinically as operation deficit (OD) or as language deficit (LD) and the children with typical normal development using optimal VBM.The developmental connections between brain gray matter and language or operation skills were examined.Methods Magnetic resonance imaging was obtained from 9 children with mental retardation presented as OD predominantly and 11 children with mental retardation presented as LD mainly,as well as the age-matched control group (11 and 14 normal children,respectively) on a 1.5 T scanner.Voxel-based morphometry analysis with an optimization of spatial segmentation and normalization procedures was applied to compare the volume of grey matter between the two groups (OD VS.control; LD VS.control).Statistically,the total and local gray matter volumes were compared between the two groups with t test.Results The total gray matter volume of OD group was [(1.030 ± 0.078) × 106 mm3].Compared to that of controls [(0.984 ± 0.058) × 106 mm3],it was increased significantly (t =-2.6,P ＜ 0.05).And the gray matter volume in the posterior cingulated gyrus,left superior prefrontal gyrus,left cuneus,left middle prefrontal gyrus and the body of left caudate nucleus showed significantly increased.Meanwhile,the total gray matter volume of the MR children presented as LD [(1.002 ± 0.068) × 106 mm3] showed significantly increased(t =-3.0,P ＜ 0.05) compared with that of control group [(0.957 ±0.057) × 106 mm3].The gray matter volume in bilateral thalami,the left inferior temporal gyrus,the left inferior frontal gyrus,and the left cerebellum of the LD group was more than that of normal children.Conclusion As revealed by VBM,there are differences in alterations of gray matter volume between MR children presented with OD and with LD relative to control.

Objective To evaluate the values of indirect fluorescent antibody test for the diagnosis and therapeutic evaluation of trichinosis.Methods Indirect fluorescent antibody test using frozen section of the purified Trichinella larvae as antigen was employed on the detection of anti-Trichinella antibodies in sera from the mice infected with T. spiralis and the patients with trichinosis. Sera from patients with trichinosis were collected at different time intervals after the onset of disease and after treatment with albendazole (20 mg/kg per day). Sera from the patients with other parasitic diseases and from healthy individuals were used as control.Results The anti-Trichinella antibodies were detected in the mice as early as 2 weeks after infection. The specific antibodies were observed in 86.38% of the of the patients with trichinosis. All sera from patients with filariasis, schistosomiasis and echinococcosis and from healthy controls were negative. The antibody positive rate of patients with trichinosis was only 70.59% one week after the onset of disease, and increased to 91.30%, 95.83% and 100% in 2, 3 and 4 weeks after the onset respectively. The frozen section antigens could be stored at -20℃ for at least 5 years without the loss of activity. After therapy, the detection time of antibodies was 1 to 2 weeks ahead of time. The antibody positive rate increased from 87.5% before therapy to 100% one week after therapy. Serum antibody titers one week after therapy were also obviously higher than those before therapy. The distinct elevation of serum antibody levels in a short term after therapy could be considered as an objective criterion of effective therapy. The antibody negative conversion rate of the patients was 24% one month after therapy, and increased to 75% four months after therapy.Conclusions Indirect fluorescent antibody test using frozen section of the purified Trichinella larvae as antigens is a higher sensitive, specific and stable technique and can be used to diagnose and evaluate the therapeutic effect of trichinosis.