X-ray imaging and microspectroscopy of plants and fungi

X-ray fluorescence microscopy and microspectroscopy with micrometre spatial resolution and unprecedented capabilities for the study of biological and environmental samples are reported. These new capabilities are a result of both the combination of high-brilliance synchrotron radiation and high-performance X-ray microfocusing optics and the intrinsic advantages of X-rays for elemental mapping and chemical-state imaging. In this paper, these capabilities are illustrated by experimental results on hard X-ray phase-contrast imaging, X-ray fluorescence (XRF) imaging and microspectroscopy of mycorrhizal plant roots and fungi in their natural hydrated state. The XRF microprobe is demonstrated by the simultaneous mapping of the elemental distributions of P, S, K, Ca, Mn, Fe, Ni, Cu and Zn with a spatial resolution of approximately 1 x 3 micron and with an elemental sensitivity of approximately 500 p.p.b. Microspectroscopy with the same spatial resolution is demonstrated by recording near-edge X-ray absorption (XANES) spectra of Mn at a concentration of approximately 3 p.p.m.

[Effects of extraneous wild type p53 on malignant growth of human lung cancer cell line.]

BACKGROUND

To study the effects of extraneous wild type p53 on malignant phenotype of human lung cancer cell line (801-D) with mutant type p53 gene.

METHODS

The human lung cancer line (801-D) with mutant type p53 was selected and characterized with PCR-SSCP and DNA sequence analysis. Recombinant plasmid PZiPp53 was constructed , which expressed wild type p53. A transfected cell line , 801-D-p53 was obtained after transfering the plasmid into 801-D cell line by gene gun mediated and selected by G418. The wild type p53 and the alteration of malignant phenotype were detected in the transfected cell line by PCR method and cell line culture and heteroplastic transplant study.

RESULTS

The extraneous wild type p53 gene was detected in 801-D-p53 cell line cultured in vitro one year after transfection. The growth of the transfected cell line was inhibited comparing the parent cell line. The colony formation inhibition rate of the cell line was 96% and the tumorigenicity in nude mice was suppressed. The tumor growth significantly slow and the average volume of the transplant tumor was 1/28 of that of the parent cell line.

CONCLUSIONS

Extraneous wild type p53 gene may stably exist in the human lung cancer cell line with mutant type p53 after wild type p53 transfection and suppress the malignant phenotype of the transfected cell line. These results indicate that the recombinant plasmid expressing wild type p53 may be useful for gene therapy of human lung cancer.

[Effects of exogenous wild type p53 on malignant growth of human lung cancer cell line]

OBJECTIVE

To study the effects of exogenous wild type p53 suppressor gene on malignant growths of human lung cancer cell line with mutant type p53 gene.

METHOD

Four human lung cancer cell line were screened for mutations in the exon 5 through exon 8 of the p53 tumor suppressor gene with immunohistochemistry, polymerase chain reaction (PCR)/single strand conformation polymorphism (SSCP) and DNA sequence analysis. The recombinent plasmid PZIPneoSV-p53 was constructed, which express wild type p53 gene. A transfected cell line, 801-D-p53, was obtained after transferred the plasmid into 801-D cell line by gene gun mediated and selected by G418. The exogenous p53 in the transfected cell line 801-D-p53 were inspected with PCR, and the alteration of growths of the transfected cell line in vitro and in vivo was observed.

RESULT

The point mutation were CGG to CTT transversion at codon 248 in exon 7 was found in human lung cancer cell line 801-D by PCR-SSCP and DNA sequence analysis and nuclear accumulation of the p53 protein was observed. The neo gene and exogenous wild type p53 gene were detected in the transfected cell line 801-D-p53. The cell growth experiment in vitro showed that the parent cell line 801-D growth was very fast, from 1 x 10(5)/ml to 2.5 x 10(5)/ml within 6 days, the transfected PZIP-neo-SV cell line (plasmid without p53) growth as fast as 801-D, but the transfected cell line 801-D-p53 growth was inhibited seriously. The clonogenic formation rate of the parent cell line 801-D, transfected cell line 801-D-PZIP and the transfected cell line 801-D-p53 were 11.2%, 11.4% and 0.46% respectively. The clononogenic formation inhibition rate of the transfected 801-D-p53 was 96% comparing with the parent 801-D cell line. In the experiment of xenogenic tumor transplantation, each cell line was injected subcutaneously into four mice and the growth of xenogenic tumor transplant in nude mice was observed. xenograft growth in all 4 mice in both 801-D and 801-D-PZIP groups, but only 1 xenograft growth among 4 mice of 801-D-p53 group during 2 months. The average volume of xenogenic tumor transplant of 801-D and 801-D-PZIP groups were 6.500 cm3 and 2.231 cm3 respectively and the only xenograft volume of 801-D-p53 group was 0.940 cm3. The tumorigenicity of 801-D-p53 in nude mice was significantly suppressed.

CONCLUSION

Exogenous wild type p53 gene may stably exist in the human lung cancer cell line with mutant type p53 after plasmid transfection and suppressed the malignant growth of the transfected cell line 801-D-p53 in vitro and in vivo. These results indicate that the recombinent plasmid expressing wile type p53 may be useful for gene therapy of human lung cancer.

Molecular nature of a sperm acrosomal antigen recognized by HS-13 monoclonal antibody

Among the numerous monoclonal antibodies generated against human sperm antigens, HS-13 monoclonal antibody was shown to react with an intra-acrosomal antigen from human, mouse and rat. In this study, HS-13 was used as the affinity ligand for the purification of the cognate antigen from human sperm by immunoaffinity chromatography. The purified cognate antigen from human sperm, designated as HSAg-13, was found to be a protein with a molecular weight of approximately 80 kDa on SDS-PAGE in the presence of reducing reagents. This monoclonal antibody was used as the probe to study the tissue distributions and developmental expression of the cognate antigen from human, mouse and rat by immunohistochemical assays. It was concluded that the antigen recognized by HS-13 antibody is highly sperm specific and found only in sperm and mature testis, but not in any other somatic tissues examined in human and mouse. The antigen was shown to be expressed at the postmeiotic stages of spermatogenesis in mouse and rat. By using indirect immunofluorescent staining assay, HS-13 was shown to react only with the methanol-fixed acrosome-intact sperm but not with the live sperm. Following calcium ionophore A23187 treatment, acrosome-reacted sperm showed either negative staining or residual staining in the equatorial region, suggesting the intra-acrosomal location of HSAg-13. The spontaneous acrosome reaction following overnight incubation in BWW medium resulted in a statistically significant decrease of antibody-stained human sperm. In view of excellent correlations for the scoring of acrosome-intact sperm with that of fluorescence-labeled Pisum sativum agglutinin (PSA) probe, HS-13 monoclonal antibody can be routinely used for monitoring sperm capacitation and acrosome reaction.

A study on cholangitis after hepatic portoenterostomy for biliary atresia

OBJECTIVE

To investigate the clinical manifestations and factors relating to prognosis in biliary atresia (BA).

METHODS

Twenty-four cases were reviewed on clinical manifestations and bile flow after operation. All patients underwent hepatic portoenterostomy.

RESULTS

Twenty-three cases (95%) got bile flow postoperatively. Sixteen (69%) of 23 patients had 27 episodes of cholangitis. There were significant differences (P < 0.05) in the amount and bilirubin concentration of bile flow before and after cholangitis. Cholangitis also affected the life quality of BA patients.

CONCLUSION

We consider that early finding and prevention of cholangitis can improve the prognosis of BA patients.

Measurements of emittance and absolute spectral flux of the PETRA undulator at DESY Hamburg

The first synchrotron radiation beamline using a 4 m-long undulator at the 12 GeV storage ring PETRA delivers hard X-ray photons usable up to 300 keV. The photon intensity is measured on an absolute scale in the energy range between 16 and 60 keV and compared with calculated intensities. The experimental set-up described is also used to measure the horizontal and vertical emittance of the source.

Soft x-ray instrumentation and its applications at the advanced photon source

Knowledge of the intermediate energy range from 0.5-4 keV, bridging the "soft" and "hard" x-ray regions, is relatively underdeveloped. However, recent developments in the techniques of microscopy and magnetic circular dichroism have emphasized the need to operate in this energy range for microelectronic, biological, and materials science related experiments. The strong dipole-allowed 3d to 4f transitions in rare-earth magnetic materials fall in this region, as do the K-shells of many of the second and third row elements of the periodic table. Two beamlines to be constructed at the Advanced Photon Source (APS) have been designed to cover this energy region. The proposed undulator source, the beamline layout, and the experimental programs for these beamlines are described.

Oesophageal perforation caused by a coin

An unusual consequence of an initially asymptomatic coin ingestion is described to alert paediatricians that coins are not always innocuous. The case illustrates the need to investigate subtle but persistent symptoms, and also describes the surgical approach to coins that erode through the oesophageal wall.

Assessing psychopathology in Chinese psychiatric patients in Hong Kong using the Brief Psychiatric Rating Scale

This study investigated the use of the Brief Psychiatric Rating Scale (BPRS) in a sample of 155 Chinese psychiatric patients in Hong Kong. The commonly rated symptoms were those related to the spectrum of anxiety-depression, and the symptom dimensions differed only slightly from those symptom clusters reported in past studies with the BPRS. Although symptoms were rated regardless of psychiatric diagnoses, the BPRS profiles of these patients were sensitive to diagnostic distinctions. In addition, these patients were also classifiable into the 8 phenomenological types. However, the less elevated BPRS profiles across types raised the question of whether there was a tendency to under-present symptoms on the part of the patients or to under-rate symptoms on the part of the clinicians. These results were discussed in terms of the use of the BPRS for descriptive and classification studies in the Chinese setting as well as for cross-cultural research.