[Expression of matrix metalloproteinase-2, -9 and their inhibitor-1 in hypertrophic scars]

OBJECTIVE

To investigate the gene expression of matrix metalloproteinases (MMP-2, MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in proliferative and mature hypertrophic scars.

METHODS

Total RNA from 8 normal skin samples and from 16 human hypertrophic scar samples of different maturing stage was respectively extracted, and then mRNA was isolated. The gene expressions of MMP-2, MMP-9 and TIMP-1 in these samples were examined with reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

The gray scale ratio of MMP-2, MMP-9 and TIMP-1 transcription in normal skin were (3.8 +/- 0.7)%, (5.8 +/-4.4)%, (30.3 +/- 3.0)%, respectively, which were obviously higher than those in proliferative hypertrophic scar [(14 +/- 5)%, (18 +/- 5)%, (38 +/- 4)%, P < 0.05]. The expression of MMP-2 and MMP-9 genes in mature hypotrophic scar returned to normal level, but that of TIMP-1 remained high when compared with that of normal level (P < 0. 05).

CONCLUSION

The increase in MMP-2, MMP-9 and TIMP-1 gene expression might be involved in the formation of hypertrophic scars, while the lowering of MMP-2 and MMP-9 gene expression might be associated with the maturation of hypertrophic scars.

[RHCE genotyping in Chinese Han from north and Li from south]

OBJECTIVE

To establish a method which processes RHCE genotyping with PCR.

METHODS

Using PCR-SSP to detect RHCE genotype in 200 cases of Han population in north of China and Li population in south of China and detecting 5 samples of parentage testing at the same time.

RESULTS

The results of RHCE genotyping in individuals of two populations are completely accorded with the results of serology typing. And the distribution of RH genotypic frequency in Han population in north China is: RHCCEE 1, RHCCEe 3, RHCCee 88, RHCcEE 4, RHCcEe 20, RHCcee 54, RHccEE 1, RHccEe 22, RHccee; The distribution of RH genotypic frequency in Li populatin in south China is RHCCEE 2, RHCCEe 2, RHCCee 106, RHCcEE 7, RHCcEe 62, RHCcee 10, RHccEE 3, RHccEe 8. The results of RHCE genotype detecting of parentage testing samples are accorded with the results of associated identification of 13 STR loci.

CONCLUSION

PCR-SSP technology can exactly detect RHCE genotype in individuals of Han population in north China and Li population in south China.

[A PCR-RFLP analysis to HLA-B gene among Chinese northern Han populations]

OBJECTIVE

To set up the method for analyzing HLA-B gene polymorphism with PCR-RFLP, and to gain population data among northern Chinese Hans of HLA-B's restricted fragments after NlaIII digestion, and to achieve application in forensic medicine practice.

METHODS

Sample DNA was extracted by the phenol/chloroform extraction method, 943 bp-long fragments containing HLA-B exon 2 and 3 were got by PCR. The endonuclease NlaIII was applied to cut the PCR products into polymorphic fragments shorter than 943bp, then PAGE and silver staining were used to detect the digestion results, finally the digestion sites were assured by DNA sequencing.

RESULTS

Along 943bp-long PCR products, 14 length-different fragments, 20 kinds of fragment combinations were got and 6 cutting site were observed after NlaIII digestion.

CONCLUSION

HLA-B gene was highly polymorphic among Chinese northern Hans. Even with only one endonuclease, 14 restricted fragments were got and the PIC was great. Such a HLA-B PCR-RFLP analysis will have values in forensic medicine applications.

[Experimental study on closing the firearm injured soft tissue defect by skin stretch]

OBJECTIVE

To investigate the availability and effect of skin stretch in closing the firearm injured soft tissue defect.

METHODS

Eight white pigs with firearm injured soft tissue defect were divided into 3 groups. Each group I and group II had 3 pigs which were performed skin stretch. The control group had 2 pigs without stretch. The average diameter of the defect in three groups was (7.3 +/- 0.2) cm, (9.1 +/- 0.3) cm, (7.3 +/- 0.2) cm respectively, and the site of defect was on the lateral thigh and buttock.

RESULTS

Skin stretch could make a visible reduction of the wound. It was possible to close the wound by direct traction when the diameter of the buttock wound was less than 7 cm, and when the diameter of the lateral thigh wound was less than the radius of thigh. The skin stretch should not last more than 7 days and the best effect appeared in 4 to 5 days after performing the skin stretch.

CONCLUSION

The skin stretch can be applied in the repair of the firearm injured soft tissue defect. It has many advantage compared with the tradtional treatment.

[Effect of storage methods on breaking seed dormancy of Trollius chinensis Bge]

OBJECTIVE

Exploring the best seed storage method for Trollius chinensis.

METHOD

Different temperatures were applied to the seed storage in wet sand and dry sand, and the embryo-endosperm ratio and germination rate were inspected.

RESULT

The dormancy of T. chinensis seeds could only be broken in lower temperatures. The newly collected seeds set out to germinate after 75 days of storage at 5-6 degrees C when the embryo-endosperm ratio reached 47%, and the time of seed germination varied with the length of storage time before low-temperature treatment.

CONCLUSION

The best storage method for the seed of T. chinensis is keeping it in dry for 6-8 months with an additional 1 month of low-temperature treatment to follow.

Construction and characterization of a human chromosome 2-specific BAC library

We have constructed a human chromosome 2-specific bacterial artificial chromosome (BAC) library using DNA from the somatic cell hybrid GM10826. The average size of the clones is about 63 kb. The coverage and distribution of the library were estimated by screening with known polymorphic genetic markers and fluorescence in situ hybridization (FISH). Twenty-one markers tested positive when DNA pools prepared from approximately one-sixth of the library were screened with 33 known markers. This is consistent with the theoretical calculation of 63% coverage at one genomic equivalent. This suggested that the coverage of the library is approximately 5-6x. FISH analysis with 54 BACs revealed single site hybridization to chromosome 2, and the clones were distributed randomly on the chromosome. We have also performed direct sequencing of the BAC insert ends to generate sequence-tagged sites suitable for mapping and chromosome walking. This is the first reported human chromosome 2-specific BAC library and should provide a resource for physical mapping and disease searching for this chromosome.

[Clinical significance of cerebrospinal fluid beta 2-microglobulin determination in central nervous system leukemia]

Cerebrospinal fluid (CSF) beta 2-microglobulin (beta 2-MG) level was measured in 72 healthy subjects and the value (means +/- S means) was found to be 1.26 +/- 0.06 mg/L. The CSF beta 2-MG level in 33 patients who had simple acute leukemia without CNS involvement was 1.46 +/- 0.13 mg/L, which was not significantly different from that in the normal controls (P greater than 0.05). In 25 patients who had leukemia with involvement of CNS, the CSF beta 2-MG level (mean +/- S mean) was 3.94 +/- 0.30 mg/L, which was statistically different from that in the healthy controls (P less than 0.01). It is found that beta 2-MG level in CSF was one of the reliable criteria for diagnosis and indication of intrathecal chemotherapy in CNS leukemia.