Development of polymorphic SSR markers in the razor clam (Sinonovacula constricta) and cross-species amplification

Next-generation sequencing provides large-scale sequencing data with relative ease and at a reasonable cost, making it possible to identify a large amount of SSR markers in a timely and cost-effective manner. On the basis of the transcriptome database of Sinonovacula constricta obtained by Illumina/Solexa pyrosequencing, 60 polymorphic SSR markers were developed and characterized in 30 individuals. The number of alleles per polymorphic locus ranged from 2 to 7 with an average of 3.75 alleles. The observed and expected heterozygosities varied from 0.050 to 1.000 and from 0.050 to 0.836, respectively. Nineteen loci significantly deviated from Hardy-Weinberg equilibrium (P < 0.01) after Bonferroni's correction for multiple tests. In addition, interspecific transferability revealed that 20 polymorphic loci in Solen linearis were first characterized in this study. To the best of our knowledge, this is the highest number of SSRs in S. constricta and the first report of cross-species amplification. These novel polymorphic SSR markers will be particularly useful for conservation genetics, evolutionary studies, genetic trait mapping, and marker assisted selection in the species.

Hydroxycamptothecin shows antitumor efficacy on HeLa cells via autophagy activation mediated apoptosis in cervical cancer

OBJECTIVES

To investigate the effect and the mechanism of anti-tumor agent hydroxycamptothecin (HCPT) on HeLa cells in cervical cancer.

MATERIALS AND METHODS

Autophagy and apoptosis were detected by western blotting and the transfection of GFP-LC3 shRNA as well as Hoechst staining.

RESULTS

The authors found that the expression of the regulators of Beclin-1, p62, and microtubule-associated protein 1 light chain 3 (LC3) upregulated and then triggered the occurrence of cell autophagy. On the other hand, HCPT could induce to the formation of autophagy and resulted in cell apoptosis after autophagy.

CONCLUSION

HCPT can alter cell autophagy and then trigger cell apoptosis to achieve antitumor effects.

Metabolic response of maize plants to multi-factorial abiotic stresses

Clarification of the metabolic mechanisms underlying multi-stress responses in plants will allow further optimisation of crop breeding and cultivation to obtain high yields in an increasingly variable environment. Using NMR metabolomic techniques, we examined the metabolic responses of maize plants grown under different conditions: soil drought, soil salinity, heat and multiple concurrent stresses. A detailed time-course metabolic profile was also performed on maize plants sampled 1, 3 and 7 days after initiation of soil drought and heat stress. The metabolic profile of maize plants subjected to soil drought was more similar to plants exposed to salt stress than to heat-stressed plants. Drought-stressed maize plants subjected to salt or heat stress showed distinct integrated metabolic profiles compared with those exposed to either stressor individually. These differences show the considerable metabolic plasticity of maize in response to different growth conditions. Moreover, glucose, fructose, malate, citrate, proline, alanine, aspartate, asparagine, threonine and one unknown compound fluctuated obviously between maize plants grown in controlled growth cabinet and a natural regime. These changes were associated with the TCA cycle and core nitrogen metabolism, and could be related to their multiple functions during plant growth. The evident stress-induced trajectory of metabolic changes in maize indicated that the primary metabolic responses to soil drought, heat and combined drought and heat stresses occurred in a time-dependent manner. Plasticity at the metabolic level may allow maize plants to acclimatise their metabolic ranges in response to changing environmental conditions.

Effect of siRNA targeting HER2/neu on the proliferation and viability of prostate cancer PC-3M cells

The aim of this study was to investigate the effect of a small interfering RNA (siRNA) targeting human epidermal growth factor receptor 2 (HER2/neu) on the proliferation and viability of prostate cancer PC-3M cells. Chemically synthesized siRNA targeting HER2/neu was transfected into PC-3M cells by using liposomes, and cells transfected with empty liposomes, a negative siRNA sequence, or nothing (untransfected) were used as controls. mRNA and protein levels of HER2/neu were detected using reverse transcription-polymerase chain reaction and western blot, respectively. The inhibitory action of HER2/neu siRNA on the in vitro growth of PC-3M cells was assessed by the cholecystokinin 8 assay and apoptosis was detected using flow cytometry. Cells transfected with HER2/neu siRNA showed decreased mRNA and protein levels of HER2/neu compared to control groups (P < 0.05). The survival rate of PC-3M cells decreased significantly after transfection with HER2/neu siRNA compared to that of untransfected cells (55.39 ± 1.60 and 81.42 ± 0.80%, respectively; P < 0.05). The apoptosis rate in cells transfected with HER2/neu siRNA was quite high (45.60 ± 0.70%) compared to that of blank control, empty liposome, and negative siRNA sequence groups (P < 0.05). In conclusion, siRNA targeting HER2/neu inhibits HER2/neu expression in PC-3M cells, resulting in an inhibition in proliferation and an induction of apoptosis.

In vivo toxicity of nano-alumina on mice neurobehavioral profiles and the potential mechanisms

The rapid development and expanding applications of nanotechnology have led to enhanced exposure of human body to nanoparticles. It is, therefore, necessary to address the safety issue via rigorous toxicological evaluation and to understand the underlying interaction mechanism. However, only a few studies to date have evaluated the safety of nano-sized materials and their potential adverse effects on biological systems. In this study, we sought to investigate the potential toxicity of aluminum oxide (alumina) nanoparticles in ICR strained mice, focusing on potential neurobehavioral defects and the possible mechanisms. The results demonstrated that nano-alumina impaired neurobehavioral functions, including lengthened escape latency, shorter time spent in the target quadrant and reductions in the number of platform crossing. In addition, it induced cell necrosis and apoptosis, which were likely mediated by the reduction of MMP and ROS, and the induction of the caspase-3 gene. Our results implicated that mitochondrial impairment plays a key role in neurotoxicity of nano-alumina, sequent oxidative damage and neural cell loss, especially necrosis, may be direct causes for the neurobehavioral defects. Collectively, nano-alumina presents a strong pro-cell death effect on ICR mice in vivo, suggesting that nano-alumina may serve as an inducer for neural toxicology. Findings in the present study indicating that surface chemical characteristics and nanoscale sizes of nano-alumina could co-contribute significantly to neurotoxicity. The impaired neurobehavioral patterns indicate that nano-alumina particles are more toxic to the cerebrum than those of nano-carbon with the same nanoparticle size and micro-alumina with the same surface chemical characteristics.

Congenital lumbosacral limb duplication: a case report

We report a case of congenital lumbosacral limb duplication at the pelvis, lower limb, and foot of a 4-year-old boy. The patient presented with a supernumerary lower limb joined at the lumbosacral region by a bony connection. A pseudo-navel and a pseudo-penis were found on the supernumerary limb and foot duplication was noted at the end. Radiography and a 3-dimensional computed-tomography reconstruction revealed duplication of an inversely oriented pelvis dorsal to the normal pelvis, semi-vertebrae in T7 to T9, thoracolumbar scoliosis, lumbosacral vertebral dysplasia, and dislocation of the left hip. Magnetic resonance imaging demonstrated a tethered spinal cord and an adipoma in the sacral canal. Motor conduction velocity was reduced in the left peroneal nerve. Surgery to remove the supernumerary limb was successfully performed. The patient recovered well and further surgery is planned for functional reconstruction of the left lower limb.

Anti-proliferative Effects of Oridonin on SPC-A-1 Cells and its Mechanism of Action

Oridonin, an extract from the Chinese herb Rabdosia rubescens, is currently one of the most important traditional Chinese herbal medicines. We investigated the anti-proliferative effect of oridonin on the lung cancer cell line SPC-A-1 and its mechanism of action. Growth inhibition was measured using a microculture tetrazolium assay and apoptosis was measured by several standard methods. Western blot analysis measured the expression of bcl-2 and bax proteins. Oridonin (> 28 μmol/l) inhibited the growth of SPC-A-1 cells and induced apoptosis. Marked morphological changes indicative of apoptosis were observed, especially in cells treated with oridonin for 48–60 h. Western blot analysis revealed downregulation of bcl-2 and upregulation of bax proteins following treatment with oridonin for 48 h. We conclude that oridonin demonstrated anti-proliferative and apoptosis-inducing effects on SPC-A-1 cells in vitro, and that changes in bcl-2 and bax protein levels may play an important role in its mechanism of action.

Nanoscale analysis of biofunctional molecules and components

In basic medical research, as well as in concrete clinical applications, the nanoscale analysis of biofunctional units is of strongly increasing relevance. Dedicated investigations on molecules, molecular composites or functional units can efficiently be performed ex or in situ by scanning probe methods and, namely, by scanning force microscopy. In the following investigations, the folding behavior of DNA is presented as an example of basic research in medicine. In contrast, the investigation of bioadsorption phenomena in systems on which apheresis therapies are based provides a real contribution to applied medicine.

[Allografting for massive bone defect: bone and soft tissue reconstruction and postoperative rehabilitation]

OBJECTIVE

To evaluate the results of limb function and the methods of bone and soft tissue reconstruction of patients treated with allografting.

METHODS

From May 1992 to January 1999, 90 patients suffered from bone malignant tumor were treated with allografting in different methods of internal fixations. The average follow-up was 37.5 months. The limb postoperative function, complications related to different surgical methods were compared according to Enneking evaluation system.

RESULTS

Skin necrosis, infection, non-union, fracture of allograft were the main complications which affect patients' limb postoperative functions. Of the 90 fresh-frozen allografting procedures, the final results of operation showed that hip joints and knee joints were better than the shoulder joints. More than 80% of the patients treated with interlocked intramedullary nail and allograft-prosthesis combination led to an over-all result that was excellent and good. Interlocked intermedullary nail was of recommended method of internal fixation. Early exercises of operative limbs could promote function recovery.

CONCLUSION

Using of interlocked intramedullary nail and allograft-prosthesis combination are of recommended operation method and can be applied with better results, and early exercises of operative limbs will lead to better functions.

[Resolution of overlapping mass spectra of azobiphenyl dyes by subwindow factor analysis technique]

Subwindow factor analysis(SWFA) has been proven to be an effective data processing technique. In this paper, it is applied to the resolution of overlapping GC-MS peaks. A two-component sample of azobiphenyl dyes (3,3'-dichlorobenzidine, 4,4'-methylene-bis-(2-chloroaniline)) was prepared and a data set from a mixture of azobiphenyl dyes recorded by GC-MS was obtained. Then the overlapping GC-MS data were resolved by SWFA. The results show that both mass spectrum and chromatogram of components can be resolved from multicomponent overlapping data. The resolved spectra were in good consistence with the mass spectra of standard samples. At the same time, overlapping GC-MS data were also resolved by WFA. In Comparing with WFA technique, SWFA is more convenient, and the speed of resolution could be increased.

The structure of the nucleosome core particle of chromatin in chicken erythrocytes visualized by using atomic force microscopy

The structure of the nucleosome core particle of chromatin in chicken erythrocytes has been examined by using AFM. The 146 bp of DNA wrapped twice around the core histone octamer are clearly visualized. Both the ends of entry/exit of linker DNA are also demonstrated. The dimension of the nucleosome core particles is approximately 1-4 nm in height and approximately 13-22 nm in width. In addition, superbeads (width of approximately 48-57 nm, height of approximately 2-3 nm) are occasionally revealed, two turns of DNA around the core particles are also detected.

Visualization of chromatin folding patterns in chicken erythrocytes by atomic force microscopy (AFM)

The organization of the higher order structure of chromatin in chicken erythrocytes has been examined with tapping-mode scanning force microscopy under conditions close to their native environment. Reproducible high-resolution AFM images of chromatin compaction at several levels can be demonstrated. An extended beads-on-astring (width of approximately 15-20 nm, height of approximately 2-3 nm for each individual nucleosome) can be consistently observed. Furthermore, superbeads (width of approximately 40 nm, height of approximately 7 nm) are demonstrated. Visualization of the solenoid conformation at the level of 30 nm chromatin fiber is attained either by using AFM or by using electron microscopy. In addition, tightly coiled chromatin fibers (approximately 50-60 nm and approximately 90-110 nm) can be revealed. Our data suggest that the chromatin in the interphase nucleus of chicken erythrocyte represents a high-order conformation and AFM provides useful high-resolution structural information concerning the folding pattern of interphase chromatin fibers.

[The surgical treatment of partial atrioventricular canal defect]

This paper reports 11 cases of partial atrioventricular canal defect in our hospital. It also discusses the diagnosis of complication prevention and treatment with patient and the disposal during operation term, emphasizes that once definite diagnosis has been made, operation must be taken as soon as possible. Skillfully grasp surgery anatomy and exact suture techniques is the key to avoid conduction damage.

Interaction between HMG proteins (1 + 2) and the negative regulatory region 1 (NCR1) in the 5'-flanking sequence of the human beta-globin gene

The pattern of high mobility group proteins 1 and 2 (HMG1,2) interaction with the 5'-flanking sequence of the human beta-globin gene has been analyzed by scanning tunnelling microscopy (STM). A 200 bp negative regulatory region in the 5'-flanking sequence of the human beta-globin gene can be folded by HMG proteins 1 and 2 into a circular structure (diameter 70 +/- 6 A) with a linear tail which seems to be a left-handed double helix structure.

Atomic force microscopy of uncoated plasmid DNA: nanometer resolution with only nanogram amounts of sample

Reproducible, high-contrast, nanometer-resolution AFM images of uncoated plasmid DNA can be obtained with nanogram quantities of DNA with the help of two advances in sample preparation: (1) Heating a DNA solution at 35 degrees C for 10 to 20 minutes before deposition on mica helps separate and spread the DNA, and (2) Using 5 microliter drops of the heated DNA solution in the concentration range of 2 to 10 nanogram/microliter in contact with a specially prepared mica surface for 5 to 10 minutes gives optimal coverage with only nanograms of DNA.

[Effects of 3 Chinese medical prescriptions on alkaline reflux gastritis in rats]

The experimental alkaline reflux gastritis in rats was established after 9 weeks of anastomosis between stomach and jejunum. The experiment shows that xiangsha liujunzi decoction, xiaochaihu decoction and dahuang gancao decoction all help to inhibit edema, hyperamia and extravasted blood, as well as depress inflammatory infiltration and hyperplasia. The number of intestinal metaplasia in the group treated with xiangsha liujunzi decoction is decreased. All the three prescriptions are not able to lower the contents of bile acid in the stomach.

An occupational hygiene survey in a Chinese viscose rayon factory

The retinopathy (microaneurysm/small dot hemorrhage) is an early and specific biological indicator to quantitatively evaluate the CS2 exposure. The appearance of retinal lesions was observed among Yugoslavian, German and American workers exposed to CS2. However, among Finnish CS2 workers a positive result was not obtained. We suggested a different response to CS2 exposure between two ethnic populations. We had an opportunity to do a cross-sectional medical and occupational hygiene survey in a Chinese rayon staple plant. Cross-sectional medical examinations failed to show any chronic CS2 effects on the Chinese workers.

Atomic force microscopy of single- and double-stranded DNA

A method has been developed for imaging single-stranded DNA with the atomic force microscope (AFM). phi X174 single-stranded DNA in formaldehyde on mica can be imaged in the AFM under propanol or butanol or in air. Measured lengths of most molecules are on the order of 1 mu, although occasionally more extended molecules with lengths of 1.7 to 1.9 mu are seen. Single-stranded DNA in the AFM generally appears lumpier than double-stranded DNA, even when extended. Images of double-stranded lambda DNA in the AFM show more sharp kinks and bends than are typically observed in the electron microscope. Dense, aggregated fields of double-stranded plasmids can be converted by gentle rinsing with hot water to well spread fields.

Parallel stranded DNA under the scanning tunnelling microscope

Using scanning tunnelling microscopy, we have directly observed parallel stranded DNA helixes of 43 nucleotides in length. The double helix is right-handed and has an average spacing, 17.43 A (+/- 1 S.D.: 2.30 A), and an average apparent depth, 4.79 A (+/- 1 S.D.: 1.04 A) for each groove. The average pitch of the helical turn is 34 A (+/- 1 S.D.: 3.35 A) and consists of no more than ten base pairs. The diameter of the helix is approx. 17-20 A. Our results provide direct evidence for the existence of a parallel structure of DNA in vitro and some details of its fine structure.

Conformation of DNA-DNA polymerase I complex observed by scanning tunneling microscopy

The conformation of a complex of a 41 mer/31 mer DNA fragment and the Klenow fragment of DNA polymerase I of Escherichia coli was studied by scanning tunnelling microscopy (STM). The results shows that near two turns of double helix of this DNA fragment was outside of enzyme while another part containing more than one turn of helix and 10 nucleotides single strand was combined with enzyme. The dimension and shape of DNA polymerase I (KF) in complex were different from that of free enzyme. The conformation of DNA-DNA polymerase I (KF) complex and the application of STM in studying structure of complex of DNA polymerase with DNA were discussed.

Determination of eight elements in six human cancer cell lines and two human normal cell lines by PIXE

Gastric, hepatic, and pulmonary cancer cell lines, and the third passage of normal gastric and pulmonary cell lines were analyzed by proton induced X-ray emission (PIXE) method. The contents of element Sr, Ca, Fe, Zn, P, K, Cu, and As in the cell lines were determined. The Sr, Ca, Fe, Zn, and As contents in cancer cell lines were significantly lower than those in the normal cell lines (p less than 0.05), whereas there were no significant differences for the P, K, and Cu contents (p greater than 0.1). The results suggest that the need of some essential elements has been diminished in cancer cell proliferation.

An epidemiological study on carbon disulfide angiopathy in a Chinese viscose rayon factory

To assess long-term vascular effects of occupational carbon disulfide (CS2) exposure, we examined 376 exposed and 325 unexposed Chinese workers with a medical and work-history questionnaire, a chest-pain questionnaire, blood pressure and blood cholesterol measurements, routine urinary tests, monochromatic fundus photography and other tests. Data from 354 exposed and 177 age- and sex-matched reference workers were evaluated. Personal exposure monitorings were performed simultaneously with a passive dosimeter using gas chromatography. Monochromatic fundus photography revealed no CS2-retinopathy characterized by microaneurysms and/or small dot hemorrhages, and no effects of CS2 on blood pressure and blood cholesterol were found. These negative results may have been due to the low daily exposure averages, which varied between 0.01 and 12.8, with a mean of 1.5 ppm. The present study suggested that the no-effect level of CS2 exposure on the development of retinopathy was around 2 ppm (8-h time weighted average), and the absence of adverse CS2 effects among the workers studied supported the current standard for occupational CS2 exposure of 10 mg m-3 in China.