Search

Objective: To study cellular mechanism of cardiomyocytes injury in the early stage of crush injury by observing some effects of crush injury rat sera on cultured neonatal rat cardiomyocytes., Methods: One to three days old neonatal rat cardiomyocytes were cultured in vitro and some effects of crush injury rat sera on beating rate, cell surface area, total protein content, 3H-Leu incorporation, intracellular calcium concentration ([Ca2+]i) and Fos protein expression were observed in cultured rat cardiomyocytes., Results: Compared with normal rat serum group, crush injury rat sera decreased beating rate(beats/min) of cardiomyocytes from 88.3 to 26.4, cell surface area, total protein content, 3H-Leu incorporation, [Ca2+]i (nmol/L) and PI of Fos protein expression were increased., Conclusion: Crush injury rat sera suppress cell beating, increase intracellular calcium, induce Fos protein synthesis and cause cell hypertrophy, which may cause cardiac injury in the early stage of rush injury.

Objective: To study the relationship between DNA degradation and postmortem interval of corrupt corpse., Methods: By determining the marrow DNA content with histochemical technique and image analysis., Results: The content of marrow DNA decreased gradually with prolongation of postmortem interval, and it evencould be detected till 14 days after death., Conclusion: There was a linear relationship between the degradation rate of the nuclear DNA and postmortem interval.

LLA23, an abscisic acid-, stress-, and ripening-induced protein, was previously isolated from lily (Lilium longiflorum) pollen. The expression of LLA23 is induced under the application of abscisic acid (ABA), NaCl, or dehydration. To provide evidence on the biological role of LLA23 proteins against drought, we used an overexpression approach in Arabidopsis (Arabidopsis thaliana). Constitutive overexpression of LLA23 under the cauliflower mosaic virus 35S promoter confers reduced sensitivity to ABA in Arabidopsis seeds and, consequently, a reduced degree of seed dormancy. Transgenic 35SLLA23 seeds are able to germinate under unfavorable conditions, such as inhibitory concentrations of mannitol and NaCl. At the molecular level, altered expression of ABA/stress-regulated genes was observed. Thus, our results provide strong in vivo evidence that LLA23 mediates stress-responsive ABA signaling. In vegetative tissues, it is intriguing that Arabidopsis 35SLLA23 stomata remain opened upon drought, while transgenic plants have a decreased rate of water loss and exhibit enhanced drought and salt resistance. A dual function of the lily abscisic acid-, stress-, and ripening-induced protein molecule is discussed.

Objective: To observe the degradation of actin and tubulin in the liver tissue of rats after death and to find an objective indicator of the postmortem interval (PMI)., Methods: Female rats were killed under anesthesia by ether and incubated at 21 degrees C in a temperature controlled system to simulate postmortem changes for 18 days postmortem. Protein in the hepatic tissue was extracted, actin and tubulin were then examined by western blot. Thereafter, the semi-quantitative analysis of the image of western blot was performed., Results: Actin in the liver tissue of rats could be detected at 8 days postmortem, but could not be examined after 10 days postmortem. beta-tubulin rather than alpha-tubulin could be examined after 2 days postmortem, and beta-tubulin could not be examined at 4 days postmortem., Conclusion: There is some difference in the degradation between actin and tubulin, their different preservation period postmortem may be used as a parameter for PMI estimation.

Objective: In order to find a new parameter to estimate the postmortem interval, beta-actin mRNA in lung and thoracic muscle of rats was detected at different time point postmortem., Methods: Rats were killed by neck dislocation and left in a temperature controlling system at 21 degrees C for 12 days postmortem. Total RNA in lung and thoracic muscle at different time point was extracted and beta-actin mRNA expression was examined by RT-PCR. Semi-quantification analysis of the image of electrophoresis was performed to confirm the changes of beta-actin mRNA expression., Results: beta-actin mRNA in lung of rats still could be detected at 12 days postmortem, but-disappeared in thoracic muscle at 8 days postmortem., Conclusion: The expression of beta-actin mRNA in lung and thoracic muscle could be a new parameter for estimation of PMI.

Aim: To prepare human anti-HBs Fab by bioengineering technique., Methods: The specific human anti-HBs Fab gene screened from combinatorial library was cloned into plasmid pBAD/g IIIA, then positive clone was transformed into E.coli Top10. After the fermentation and expression processes, the soluble Fab fragment in the periplasm were purified by Ni-NTA-agarose affinity chromatography,and the inclusion bodies were in turn denatured, solubilized, purified and renatured. The specificity of Fab protein was confirmed by Western blot, and binding activity to HBsAg was verified by Dot blot., Results: The quantity of soluble Fab protein purified from periplasm with Ni-NTA-Agarose which possessed good specificity as well as excellent binding activity to antigens was up to 80 mg per liter, but the biologically active protein acquired after renaturation of the inclusion bodies was quite small., Conclusion: Using pBAD/g IIIA-Top10 expression system, the soluble Fab protein with biological activity could be produced from periplasm of the E.coli Top10, and the strategy is available to prepare human anti-HBsAg Fab fragments in large quantity by gene engineering technique.

To develop a fed-batch fementation process of E. coli TOP10 containing a recombinant plasmid pBAD/HBs Fab. Cells were grown in semi-defined medium at 37 degrees C, and the feed operation using glycerol as carbon source was performed when dissolved oxygen increased. When the target cell concentration reached to 64g/L, arabinose was added to a final concentration of 0.02%. Cells were grown for another 5h with the culture temperature decreased from 37 degrees C to 30 degrees C. In the whole process, cell growth was monitored by measuring OD600 of samples taken at 1/2h intervals and the dissolved oxygen was kept above 30%. After the fementation, E. coli pellets were collected for purification of Fab protein. The specificity of Fab protein was confirmed by Western blot, and binding activity to HBsAg was verified by Dot blot. Cell concentration we got is 96g wet bacteria per liter, the Fab protein is about 6% of total protein of the host, that is 80mg per liter. Stable fermentation parameters were obtained for fermentation to improve productivity of the Fab protein. The Fab protein was produced in the form of soluble biologically active protein, it's better than inclusion bodies from which biologically active protein can only be recovered by complicated and costly denaturation and refolding process.

Objective: To study the feature of sudden manhood death syndrome(SMDS) in Dongguan city., Methods: The data of 284 cases of SMDS were analysized by retrospective study., Results: The distribution of age, sex, the time of death and hometown of the dead in SMDS were described. The clinical or anatomical characters of SMDS were also discussed., Conclusion: These data will contribute to the late epidemical study.

Objective: To study the relationship between degradation of marrow DNA and late postmortem interval (PMI)., Methods: Marrow were left on natural condition for 0,1,3,5,7 day after death respectively, Marrow DNA were detected by using Feulgen staining and computerized image analysis., Results: The content of marrow DNA could be detected till 7 days after death yet., Conclusion: The degradation of marrow DNA may be used on estimation the late PMI.

This article review the advance in interpretation of mixed forensic stains using DNA profiling, including autosome STR profiling, sex profiling determined by PCR, Y-specific STR profiling, mitochondrial DNA profiling and single nucleotide polymorphism profiling. The statistics methods for mixed stain has also been reviewed.

Short tandem repeats (STRs) have been widely used in forensic sciences such as stain analysis and paternity testing. Although most of STR typing could give the reliable and clear results, some unusual typing have been observed in forensic practice. The anomalous typing could result from a lot of causes, including DNA genetic variation, poor quality or quantity of DNA template, different typing system or method, nonspecific reaction in PCR or anomalous electrophoresis migration. The unusual results may disturb the right interpretation of STR typing.

Objective: To observe the changes of electrocardiogram and serum cardiac troponin I at the early stage of severe crush injury in rats., Methods: Crush injury was produced in Sprague-Dawley rats. The changes of electrocardiogram were recorded with the standard II, the serum levels of cardiac troponin I were studied by automated chemiluminescence assay., Results: The ST segment elevated considerably after crush injury and lasted 24 h, the levels of serum cTnI were much higher than those of the control groupes after 6 h of injury., Conclusion: Cardiomyocyte injury was induced in the early phase of crush injury.

Objective: To study the distribution and proportion of neuropeptide containing nervers in the sinus node in cases of sudden manhood death syndrome (SMDS) and to explore the mechanism of SMDS., Methods: Immunohistochemical staining and quantitative analysis of neuropeptide Y (NPY) and vasoactive intestinal peptide(VIP) in the sinus node in 6 cases of SMDS and in 12 cases of non-cardiac death(control group) were achieved by LSAB method and computerized image system., Results: As for NPY positive materials, VIP positive materials and the ratio of VIP/NPY in the sinus nodes, there were no significant difference between the control group and SMDS group., Conclusion: The mechanism of SMDS and the abnormality of autonomic nervous innervation in the sinoatrial nodes maybe incorrelation.

Objective: To study the depletion of cardiac troponin T in Rats of early myocardial ischaemia., Methods: Immunohistochemical method (LSAB) was used and the depletion area of CTnT in myocardial ischaemia were measured by the computer image analysis., Results: There is obviously depletion of CTnT after 15 min in myocardial ischaemia of rats, the mean of CTnT depletion of myocardial ischaemic group is significant difference compared with that of the control group (P < 0.01), and the depletion area increased with the prolongagtion of ischaemic time., Conclusion: The depletion of CTnT is one of sensitive signs of early myocardial ischaemia.

As the technologic sophistication of generation and distribution of electrical energy has grown, so has the general concern about the effects of electric fields on human health. There can be no doubt that the significance of electrical trauma will continue to grow with our increasing use of power. It is apparent that our understanding of the various forms of electric trauma must increase, while we continue to promote safety near electrical hazards and develop effective medical therapies. Tissue damage as a result of electrical injury occurs by two mechanisms which are summative in action and have a variable degree of contribute to the ultimate damage produced. Thermal tissue damage occurs as a result of heat generated within the tissue (which offer an electrical resistance) secondary to the passage of the electrical current. High temperatures can also lead to cell membrane components, e.g., phospholipids, to dissolve. Electroportation damage is the tissue damage induced secondary to the strong electric field. Transmembrane potentials caused by electrical current result in the formation of pore in the phospholipid component of the cell membrane resulting in loss of function of the cell membrane with consequent cell death.