Objective To analyze the genetic diversity of Psammosilene tunicoides,an endangered and endemic medicinal plant,in southwest China.Methods The genetic diversity of seven representational populations of P.tunicoides including 137 individuals had been investigated by amplified fragment length polymorphisms(AFLP)maker technique.Results The genetic diversity had been revealed as follow:the Nei's genetic diversity index(He),Shannon's information index(I),percentage of polymorphic loci(PPB)were 0.243 4?0.179 1,0.373 5?0.248 5,and 82.30%,respectively at the species level;and 0.091 8?0.161 0,0.140 2?0.236 2,and 30.48%,respectively at population level.The genetic differentiation index(Gst)was 0.624 6 and genetic differentiation coefficient by Shannon's diversity(Ist)was 0.624 6.The result of dendrogram of seven populations indicated that Lijiang and Gejiu of Yunnan populations shared the maximum genetic identity,though they distributed in a relatively great geographical distance;Kunming population of Yunnan had the greater genetic distance from other populations.Nine characteristic fingerprint bands that can distinguish the different populations had been acquired.Conclusion The genetic diversity of P.tunicoides is relatively higher at the species levels,while lower within population levels,and a significant degree of genetic differentiation occurrs among the populations.There is little relativity between the relationship of populations and geographical distance.The combination of characteristic fingerprint bands between intraspecies and populations provide important basis data for germplasm resources diagnostics and plant breeding by AFLP maker technique.

Objective To investigate the effect of thymosin ?1 (T?1) on cellular immune function in gastric cancer patients through observing its treatment on the differentiation of T-lymphocyte subsets from screened peripheral blood mononuclear cells (PBMCs). Methods PBMCs were obtained by centrifugation of blood samples from 18 healthy subjects and 32 patients with gastric cancer,and then cultured in the presence of culture medium with addition of T?1 at 50,10 and 1 ?g/ml for 2 d. T lymphocyte subsets (such as CD4+,CD8+ and CD4+ CD25+ Foxp3+ T cells) and Th1/Th2 multiplex cytokines were detected by flow cytometry (FCM). Results After PBMCs isolated from healthy people and patients were incubated with or without T?1,there was no significant change in percentage of CD4+,CD8+ peripheral lymphocyte subsets and ratio of CD4+/CD8+. There was no obvious change in the percentage of CD4+ CD25+ Foxp3+ T lymphocyte subsets in the normal control,but a significant increase was observed in the cells from patients with gastric cancer after treatment (P

The genus Letrouitia is newly recorded for Cambodia, including the four species as L. domingensis, L. leprolytoides, L. sayeri, and L. subvulpina. A brief description and illustrations are provided.
Cambodia* ; Lichens*

Objective To investigate the CT and MRI findings of different types of small round cell tumor(SRCT)in the nasal cavity and sinuses.Methods A retrospective analysis was conducted on the imaging data and clinical data of 35 SRCT patients confirmed by pathology.Thirty-one SRCT patients underwent CT examination,and 19 SRCT patients underwent MRI examination.Results There were 20 cases of tumors that invaded the nasal cavity and 19 cases involved the sinuses,including 11 cases of the maxillary sinus,7 cases of the ethmoid sinus,2 cases of the sphenoid sinus,and 1 case of the frontal sinus.CT findings of SRCT were all soft tissue masses.Lymphoma was relatively homogeneous with mild bone destruction,and usually involved nasal vestibular skin.Rhabdomyosarcoma(embryonic type)happened at an early age and easily caused bone destruction and metastasis.Melanoma generally occurred in the nasal septum and nasal cavity,which was prone to bleeding.Small cell neuroendocrine carcinoma was heterogeneous,with moderate to significant enhancement,bone absorption and destruction were often noticed.The MRI manifestations of SRCT were equal or long signal on T1WI,high signal on T2WI,and significant diffusion limitation on diffusion weighted imaging(DWI)and apparent diffusion coefficient(ADC)except for melanoma.On contrast-enhanced images,lymphoma showed mild to moderate enhancement,rhabdomyosarcoma showed typical"grape sign",and small cell neuroendocrine carcinoma showed"sieve"and"map-like"obvious enhancement.Typical melanoma showed a high signal on T1WI and a low signal on T2WI and usually caused bleeding.The MRI findings were related to the presence of melanoma and hemorrhage within the lesion.Conclusion SRCT of the nasal cavity and sinuses have a high degree of malignancy and poor prognosis,CT and MRI have many similar manifestations.Combining clinical data,bone destruction,MRI enhancement,and DWI sequence can effectively distinguish different types of SRCT,as well as squamous cell carcinoma of the nasal cavity and sinuses and adenoid cystic carcinoma.