[The expressional characteristics and diagnostic values of TRBC1 in mature T-cell lymphoma].

Objective: To investigate the expression characteristics of TRBC1 protein in mature T-cell lymphoma (TCL) , and compare with T-cell receptor (TCR) -Vß repertoire analysis and TCR gene rearrangement results, to explore the value of TRBC1 in the diagnosis of TCL. Methods: The expression of TRBC1 was detected by multi-parameter flow cytometry in 30 cases of TCL, 40 cases of normal controls and 50 cases of patients without T lymphocyte proliferative diseases (non-TCL) admitted to the Department of Hematology, The First Affiliated Hospital of Nanjing Medical University. The diagnostic value of TCRVß repertoire analysis, TCR gene rearrangement and TRBC1 restricted expression detection in TCL was evaluated. Results: The positive rates of CD4(+)T and CD8(+)T cell subsets TRBC1 in normal control group were (39.6±6.5) % and (39.3±4.4) %. The positive rates of CD4(+)T and CD8(+)T cell subsets TRBC1 in non-TCL were (39.1±3.8) % and (36.0±8.4) %. All 30 cases of TCL were CD3(+)TCRγδ(-), and the positive rate of TRBC1 was >92.3% or <12.7%. All cases showed restrictive expression pattern (monoclonal expression) , which was significantly different from those of the normal control and the non-TCL cases (P<0.001) . In terms of the diagnostic performance of T cell clonality, the sensitivity of TRBC1 was 100%, the positive detection rate of TCR gene rearrangement was 92.8%, and the sensitivity of TCRVß detection was 94.1%. Kappa test showed high consistency among the three detective methods. Conclusion: Multi-parameter flow cytometry detection of TRBC1 expression level can quickly and efficiently diagnose mature T-cell lymphoma, which has good clinical application value.

Influence of disordered packing pattern on elastic modulus of single-stranded DNA film on substrate.

Determining mechanical properties of single-stranded DNA film grafted on gold surface is critical for analysis and design of DNA-microcantilever biosensors. However, it remains an open issue to quantify the relations among the disordered packing patterns of DNA chains, the mechanical properties of DNA film and the resultant biodetection signals. In this paper, first, the bending experiment of microcantilever is carried out to provide the basic data for a refined multi-scale model of microcantilever deflection induced by ssDNA immobilization. In the model, the complicated interactions in DNA film (consisting of DNA, water molecules and salt ions) are simplified as effective interactions among coarse-grained soft cylinders, which can reveal the varieties of DNA structure in the circumstances of different lengths and salt concentrations; Ohshima's distribution of net charge density is employed to incorporate compositional variations of salt ions along the thickness direction into the Strey's mesoscopic empirical potential on molecular interactions in DNA solutions, and the related model parameters for ssDNA film on substrate are obtained from the curve fitting with our microcantilever bending experiment. Second, the effect of nanoscopic distribution of DNA chains on elastic modulus of ssDNA film is studied by a thought experiment of uniaxial compression, and the disordered patterns of DNA chains are generated by Monte Carlo method. Simulation results point out that nanoscale ssDNA film shows size effect, gradient and diversity in elastic modulus and can achieve maximum stiffness by preferring a disordered and energetically favorable packing pattern collectively induced by electrostatic force, hydration force and configurational entropy.

Nanomechanical behaviors of microcantilever-based single-stranded DNA chips induced by counterion osmotic effects.

Experiments show that deflections of microcantilever-DNA chip can be induced by many factors, such as grafting density, hybridization efficiency, concentration, length and sequence of DNA molecules, buffer salt concentration, time, and temperature variation. However, there are few theoretical works on microcantilever-DNA chips. The present paper is aimed to study the influence of counterion effects of single-stranded DNA (ssDNA) polyelectrolyte solution on the nanomechanical behaviors of microcantilever-based ssDNA chips during packing process. First, the effect of osmotic pressure induced by ingress of counterions into DNA brush structures is studied with Hagan's model for a cylindrical polyelectrolyte brush system on the basis of Poisson-Boltzmann distribution hypothesis. Second, Zhang's two-variable method for a laminated cantilever is used to formulate a four-layer energy model for ssDNA chips with weak interactions. Third, the influence of grafting density, ssDNA chain length, and salt concentration on packing deflection is investigated using the principle of minimum energy. The predictive tendency is qualitatively similar to those observed in some related ssDNA chip experiments. The difference between the four-layer model and the simplified two-layer model for ssDNA chips is also discussed.

[Recent advances of heterologous gene expression in E. coli].

In recent years, along with the rapid development of genetic engineering technologies, a vast amount of valuable proteins have been expressed in E. coli with high productivity. The problems concerning the productivity and purity of the heterologous proteins are no longer the major ones, as many expression system and protein purification schemes have been developed and perfected. More attention is being payed to the activity, specific activity, correct folding and intactness of the heterologous proteins. Perhaps it is the solutions to such problems that will finally lead to the maturity of the application of recombinant proteins.

Distribution of glutamine-like immunoreactivity in the cerebellum of rat and baboon (Papio anubis) with reference to the issue of metabolic compartmentation.

The cellular and subcellular localization of glutamine, a major glutamate precursor, was studied by means of an antiserum raised against glutaraldehyde-fixed glutamine. Ultrathin sections from the cerebellar cortex of rat and baboon (Papio anubis) were incubated sequentially in the primary antiserum and in a secondary antibody coupled to colloidal gold particles. The labelling intensity was quantified by computer-aided calculation of gold particle densities. High levels of immunoreactivity occurred in glial cells (Bergmann fibres, astrocytes, and oligodendrocytes), intermediate levels in cell bodies and processes of granule cells, and low levels in terminals of presumed GABAergic or glutamatergic fibres (terminals of basket and Golgi cells, and of parallel, mossy, and climbing fibres). The labelling intensity of Purkinje cells showed some variation, but never exceeded that in glial cells. Within the nerve fibre terminals, the glutamine-like immunoreactivity showed some preference for mitochondria, but was otherwise evenly distributed. The predominant glial localization of glutamine was also obvious in light microscopic preparations processed according to the postembedding peroxidase-antiperoxidase procedure. Gold particle densities over different types of profile in glutamine immunolabeled sections were compared with particle densities over the corresponding types of profiles in neighbouring sections labelled with an antiserum to glutaraldehyde-fixed glutamate. The glutamate/glutamine ratio, expressed arbitrarily by the ratio between the respective gold particle densities, varied by a factor of about 6, with the highest ratio in the putative glutamatergic mossy and parallel fibre terminals, and the lowest ratio in glial elements. The remaining tissue components displayed intermediate ratios. The present study provides direct morphological evidence for the existence in the brain of distinct compartments with differing glutamate/glutamine ratios.

Maternity care in China.

PIP: China's 1-child policy has intensified couple's desire for the safe delivery of a healthy infant and necessitated improvements in maternity care. Since the late 1970s, systematic maternity care has been available to women in China from early pregnancy to 42 days after delivery. In addition, over 50 major cities offer sophisticated perinatal care services, including prenatal intrauterine diagnosis and genetic consultations. The maternal mortality rate has declined from 15/1000 in 1949 to the present rate of 0.5/1000 while infant mortality dropped from about 200/1000 to 35/1000 in this same period. 15-20% of current deliveries are by cesarean section, often through the use of acupuncture which minimizes blood loss. To encourage rural women to deliver in hospitals, a 50% discount is provided for surgical costs. To encourage better infant care and raise the breast-feeding rate among working mothers, the Ministry of Labor and Personnel has proposed a 90-day maternity leave regulation. The Chinese Government pays a 5-yuan allowance to only children until they reach the age of 15 years and 1-child families are given priorities in kindergarten, school, housing, and employment assignments. China's well-organized maternity care network consists of 3 levels: on-the-street stations, clinics that keep detailed records on pregnant patients, and hospitals that handle high-risk pregnancies.^ieng