[Cloning and sequence analysis of a pseudogene of liver regeneration augmenter in rats]

OBJECTIVE

To investigate the status of the augmenter of liver regeneration (ALR) in rat's genome.

METHODS

Polymerase chain reaction (PCR) was used to amplify the genomic DNA of rat, with a set of specific primers designed according to the cDNA sequence of ALR. The products were ligated into pGEM Teasy vector. Two positive clones were sequenced separately.

RESULTS

Two products were amplified from the rat's genome by PCR. After sequencing, one pseudogene was identified. The homology of the amino acid sequence between the ALR and its pseudogene was 88.8%.

CONCLUSIONS

ALR pseudogene is found in rat's genome, implying that there is an ALR multigene family. This finding lays a foundation for further study of ALR molecular evolution mode.

[Effects of lead on neurobehavior and neurochemistry in rats]

Effects of exposure to lead on neurobehavioral function, content of monoamine neurotransmitter in hippocampus, and brain level of lipid peroxide were studied in 45 SD rats. Results showed learning and memory abilities of the rats were affected in exposure to lead of 1333.3 mg/kg (with their blood lead level of 6.23 mumol/L), their motor activities changed and emotional status became unsteady with 266.7 mg/kg of lead (with blood lead of 4.20 mumol/L) and 1333.3 mg/kg of lead, respectively, and levels of dopamine neurotransmitter and its metabolites declined and those of lipid peroxide increased with increasing exposure to lead. It is postulated changes in levels of neurotransmitter, such as monoamine and lipid peroxide, could explain the mechanism for damage in neurobehavioral function caused by lead exposure.

[Studies on voice identification]

The spectrographic method of voice identification was investigated and its application in forensic sciences was discussed.

[Histomorphometry of silicon nitride composite endosteal implant in dogs]

OBJECTIVE

To study the dynamic changes of bone interface with silicon nitride (Si3N4) composite implants.

METHODS

4 Beagle dogs were experimental animals, Si3N4-HA and pure Si3N4 implant were experimental group, and Ti and Ti-HA were used as comparisons. They were implanted into dogs' femurs by stages. Histomorphometry was used to analyse and compare bone growth metabolism of bone interface with implant as well as evaluation of biocompatibility from quantitative and dynamic aspects.

RESULTS

Parameters expressing mineralization and speed of deposition at the Si3N4-HA bone interface were higher than comparisions' at the first month. After 6 months, pure Si3N4's bone histomorphometic parameters had no notable difference with others.

CONCLUSION

New implant material is useful to the clinic. The histomorphometry is of much value for the study of interface bone metabolism from quantitative and dynamic point of view.

A study of the relationship between caries activity and the status of dental caries: application of the Dentocult LB method

OBJECTIVE

To clarify the relationship between caries activity and the status of caries of primary teeth and the relationship between the quantity of Lactobacillus in the oral cavity and the status of dental caries.

METHODS

The status of caries of primary teeth in 164 children ages 3 to 5 was examined. Caries incidence, mean DFT, and Caries Severity Index (CSI) were calculated. Based on the quantity of Lactobacilli in the saliva of preschool children detected with the Dentocult LB method of caries activity, four grades were classified: Grade 0 = 10(3) CFU/mL, Grade I = 10(4) CFU/mL, Grade II = 10(5) CFU/mL, and Grade III = 10(6) CFU/mL.

RESULTS

The results showed that 34.15% of the children had caries status beyond Grade I. There were significant differences of caries status, DFT, and CSI among different grades, all of which increased with grades. There was a high correlation between grades and caries incidence, DFT, and CSI in the 164 preschool children.

CONCLUSION

As a Caries Activity Test (CAT), detection of Lactobacilli may reveal the status of dental caries and provide valuable information for the prevention and treatment of dental caries.

[Characteristics of N2O emissions from vegetal soils on Fildes peninsula, Antarctica]

The N2O fluxes from the vegetal soils were first measured on the Fildes peninsula, Antarctica, and the total N2O emission was also estimated in the summer 2 months. The daily variations of N2O fluxes appeared single-peak trend under the sunshine or rainy weather conditions but they were irregular under the snow weather conditions and inconsistent with the atmospheric temperatures. The seasonal variations of the N2O fluxes were affected by the temperature and rainfall. The conditions during the transitions between dry and wet seasons improved the N2O emission. The total N2O emissions from moss and lichen soils were 3.7152 kg and 2.5344 kg, respectively. It follows that the vegetal soils are the sources for the atmospheric N2O on the Fildes peninsula, Antarctica.

[A study on the secondary infection in families in which hepatitis A patients were isolated and treated in hospitals and those in which patients stayed at home]

This study was conducted during the epidemic season in Hang Zhou, zhejiang in the spring of 1988. HAV infection rates were compared between close contacts of the hepatitis A patients isolated in hospitals and those stayed at home. It was found that there was significant difference between the HAV infection rates in the group of close contacts of hepatitis A patients who have been hospitalized within 5 days and those in the group stayed at home or those in other groups. Whereas the HAV infection rates in the group of close contacts of HA patients remained at home were not significantly different from those in other groups. The results showed that HA patients had to be isolated and treated in hospital early. HAV inapparent infection rate was 86.21% in this study. The ratio between HAV apparent infection and inapparent infection was 1:6.25.

[Study on blood coagulant/fibrinolytic activity at plasma and monocytic levels in coronary heart disease patients with Blood-Stasis Syndrome of traditional Chinese medicine]

OBJECTIVE

To explore and compare the changes of coagulant/fibrinolytic activity in coronary heart disease (CHD) patients with Blood Stasis Syndrome of TCM and evaluate the roles of these changes.

METHODS

Eighty patients of CHD were divided into two groups by Syndrome Differentiation of TCM, the Blood-Stasis (BS) group (30 cases) and the non-Blood-Stasis (NBS) group (50 cases, including 27 cases of Phlegm-Dampness Syndrome and 23 cases of Qi-Stagnation Syndrome); and 20 healthy persons were enrolled as normal control group. Tissue type plasminogen activator (t-PA) and its inhibitor (PAI-1) in plasma and in human peripheral blood monocyte cell (PBMC), as well as the procoagulant activity (PCA) in PBMC were measured by chromogenic substrate method.

RESULTS

The plasma PAI-1 activity and PCA of PBMC in the BS group were significantly higher than those in the NBS group and the normal control group (P < 0.01). PAI-1 activity of PBMC in the two groups of CHD patients was higher than those in the normal control group significantly (P < 0.01), but no significant difference was found between the BS group and the NBS group (P > 0.05). The difference of plasma t-PA activity between the two groups of CHD was insignificant. The PBMC t-PA activity in the BS group was lower than that in the NBS and normal control groups (P < 0.01).

CONCLUSION

In the CHD patients with BS, the PBMC PCA was increased and the fibrinolytic activity at both plasma and monocyte levels lowered significantly, these changes in coagulant/fibrinolytic activity may be the important pathologic factors in forming BS which suggests that CHD patients with BS were in the prothrombotic state.

[A study on the change of caries activity of children with fixed orthodontic treatment]

OBJECTIVE

To investigate the change of caries activity in children with fixed appliance.

METHODS

30 children of permanent dentition were treated with edgewise appliance. CAT was used to test the degree of caries activity before the orthodontic treatment, at the first week, at the first month, at the third month and at the sixth month of appliance bonding respectively.

RESULTS

Compared with pre-treatment, there was a significant difference of CAT at the first, third and sixth month of treatment; compared with the first week of treatment, there was also a significant difference of CAT at the third and sixth month of treatment.

CONCLUSIONS

The CAT degree increases in children with fixed orthodontic appliance and these children are more sensitive to dental caries.

[Clinical significance of changes of interleukin 6 level in pregnancy induced hypertension]

OBJECTIVE

To assess the clinical significance of changes of interleukin-6 (IL-6) level in patients with pregnancy induced hypertension (PIH).

METHODS

IL-6 level in urine and blood were measured by sandwich enzyme labeled immunosorbent assay (ELISA) in 82 patients with PIH and 30 normal pregnant women.

RESULTS

Blood IL-6 level in severe PIH patients was significantly higher than that in mild PIH patients and normal pregnant women. IL-6 level of urine in PIH patients were significantly higher than that in normal pregnant women and was associated with the severity of disease. There was a positive correlation between urinary IL-6 level and severity of renal damage in PIH.

CONCLUSION

Determination of IL-6 level is useful to understand the severity of PIH and its renal damage.

Expression and deletion analysis of EcoRII endonuclease and methylase gene

OBJECTIVE

To clone complete EcoRII restriction endonuclease gene (ecoRIIR) and methyltransferase gene (ecoRIIM) in one vector and to analyze the coordinating expression of this whole R-M system.

METHODS

Unidirectional deletion subclones were constructed with ExoIII. ecoRIIR/ M genes were preliminarily located in the cloned fragment according to the enzyme activities of subclones. Exact deletion sites were determined by sequencing, and transcriptional start sites were determined by S1 mapping.

RESULTS

The DNA fragment which was cloned into pBluescript SK + contained intact ecoRIIR gene and ecoRIIM gene, and two transcriptional start sites of ecoRIIR gene were determined. 132bp to 458bp from 3'end of ecoRIIR gene are indispensable to enzyme activities and deletion of 202bp from 3' end of ecoRIIM gene made enzyme lose the capability in DNA protection to resist specific cut with EcoRII endonuclease (EcoRII. R). Deletion of the coding and flanking sequences of one gene did not affect the expression of the other gene, and the recombinants only containing ecoRIIR gene appeared to be lethal to dcm+ host.

CONCLUSION

ecoRIIM gene linking closely to ecoRIIR gene is very important for the existence of the R-M system in process of evolution, but the key to control EcoRII R-M order may not exist in transcriptional level .

[Impact of neoadjuvant therapy on the perioperative complications of pancreatic cancer]

Pancreatic cancer is one of the most malignant digestive tract tumors with a 5-year survival rate of less than 10%. Surgery remains the basis of long-term survival of pancreatic cancer patients. With the progress of chemotherapy, neoadjuvant therapy has been gradually carried out in pancreatic cancer. There are more and more studies on the effects of neoadjuvant therapy on perioperative complications of pancreatic cancer, but the results are not consistent. This article reviews the recent studies on neoadjuvant therapy for pancreatic cancer and analyzes the impact of some key factors on perioperative complications.

Plaster board waste (PBW) - A potential fluoride leaching source in soil/water environments and, fluoride immobilization studies using soils

Plaster board waste generated from industries, usually contains major proportion of calcium as calcium sulfate. In addition, fluoride is remarkably one among the constituents of this waste material which leaches off into the soil and aquatic environments and causes fluoride pollution. In order to simulate how the dumping of PBW causes fluoride contamination in soil and water sources, shaking and stirring based batch-mode leaching studies were conducted. These studies explored the leaching of fluoride as a function of particle size, agitation time, pH of the leaching solvent (distilled water), L/S (water: PBW) ratio, temperature and electrolytes. It was explored that 1 g of plaster board waste contains18.54 mg F per gram of PBP. High leaching of 3.72 mg F per liter was studied at pH 6.02 with Ca²⁺ and TDS contents of 1050 mg L^-1 and1640 mg L^-1 respectively. The influence of sodium electrolytes such as chloride, nitrate, hydrogen carbonate, carbonate, sulfate, borate, phosphate and acetate on the leaching of fluoride from PBW was studied. The influence of fluoride leaching by sodium phosphate recorded a high value of 12.75 mg L^-1 with no detectable amount of calcium ions. The influence of eight electrolytic mixtures each containing five sodium electrolytes on fluoride leaching corroborated the highest leaching in mixtures containing phosphate followed by hydrogen carbonate/carbonate. Solutions of calcium and aluminium chloride and their mixture were used to measure the rate of leachable fluoride in solution. Furthermore, the fluoride leaching at different temperatures and acids was studied. Naturally occurring soils when blended with PBW were observed to immobilize fluoride and lessened the amount of leaching fluoride in water. Various characterization studies such as FTIR, Raman, FESEM (with EDS), XRD and XPS were carried out for PBW and its treated samples using different electrolytes. Fluoride leaching proportionate to the precipitation of carbonate and phosphate was recorded in the case of appropriate electrolyte and mixtures.