[Treatment of osteonecrosis of femoral head with free vascularized fibula grafting]

OBJECTIVE

To evaluate the effect of the treatment of necrosis of femoral head with the free vascularized fibula grafting.

METHODS

From October 2000 to February 2002, 31 hips in 26 patients with ischemic necrosis of the femoral head were treated with free vascularized fibula graft. Among these patients, 21 patients (25 hips) were followed up for 6-18 months (12 months on average). According to Steinberg stage: II period, 5 hips; III period, 8 hips; IV period, 12 hips.

RESULTS

Among 25 hips, their Harris Hip Score at all satges were improved during the follow-up. The symptom of pain diminished or disappeared after operation. The patient's ability to work and live was not limited or only slightly limited during the follow-up. Radiographic evaluation showed that most femoral heads improved (18 hips) or unchanged (6 hips) and only one worsened.

CONCLUSION

The free vascularized fibular grafting is a valuable method for femoral head necrosis. With this method, we can prevent or delay the process of the disease.

Salt cress. A halophyte and cryophyte Arabidopsis relative model system and its applicability to molecular genetic analyses of growth and development of extremophiles

Salt cress (Thellungiella halophila) is a small winter annual crucifer with a short life cycle. It has a small genome (about 2 x Arabidopsis) with high sequence identity (average 92%) with Arabidopsis, and can be genetically transformed by the simple floral dip procedure. It is capable of copious seed production. Salt cress is an extremophile native to harsh environments and can reproduce after exposure to extreme salinity (500 mm NaCl) or cold to -15 degrees C. It is a typical halophyte that accumulates NaCl at controlled rates and also dramatic levels of Pro (>150 mm) during exposure to high salinity. Stomata of salt cress are distributed on the leaf surface at higher density, but are less open than the stomata of Arabidopsis and respond to salt stress by closing more tightly. Leaves of salt cress are more succulent-like, have a second layer of palisade mesophyll cells, and are frequently shed during extreme salt stress. Roots of salt cress develop both an extra endodermis and cortex cell layer compared to Arabidopsis. Salt cress, although salt and cold tolerant, is not exceptionally tolerant of soil desiccation. We have isolated several ethyl methanesulfonate mutants of salt cress that have reduced salinity tolerance, which provide evidence that salt tolerance in this halophyte can be significantly affected by individual genetic loci. Analysis of salt cress expressed sequence tags provides evidence for the presence of paralogs, missing in the Arabidopsis genome, and for genes with abiotic stress-relevant functions. Hybridizations of salt cress RNA targets to an Arabidopsis whole-genome oligonucleotide array indicate that commonly stress-associated transcripts are expressed at a noticeably higher level in unstressed salt cress plants and are induced rapidly under stress. Efficient transformation of salt cress allows for simple gene exchange between Arabidopsis and salt cress. In addition, the generation of T-DNA-tagged mutant collections of salt cress, already in progress, will open the door to a new era of forward and reverse genetic studies of extremophile plant biology.

[The temporal and spatial distribution of vasoactive intestinal peptide and its receptor in the development of airway hyperresponsiveness]

OBJECTIVE

To determine the possible involvement of vasoactive intestinal peptide (VIP) in the development of airway hyper responsiveness (AHR).

METHODS

Twenty-five rabbits were randomly divided into five groups (5 animals each). Four groups were exposed to 2.0 ppm ozone 1 h/day for 1 (group B(0)), 2 (group B(1)), 4 (group B(2)), and 8 (group B(3)) days, respectively. The control group (group A) breathed only filtered room air. The changes of the VIP level and the mRNA expression of VIP receptor 1 (VIPR1) in the lung were detected at various ozone-stressing time points. In situ hybridization was performed to examine the distribution of VIPR1 in the lung.

RESULTS

(1) The concentration of VIP in the lung increased slowly and were maximal at day 4, then returned to the normal level. (2) The changing pattern of the VIPR1 mRNA in the lung was similar to those observed for VIP. Increases in VIPR1 mRNA were detectable by 1 day and maximal by 2 - 4 days, and then decreased slowly. (3) In group A, VIPR1 was expressed on airway epithelium, in pulmonary interstitial and focal areas of airways and vascular smooth muscles. By days 2 to 4, hybridization staining increased and the majority of VIPR1-positive cells was located in the perivascular and peribronchiolar area. On day 8, very few positive cells were seen in the lung.

CONCLUSION

VIP may play an important role in the development of AHR by binding with VIPR1.

Transgenic evaluation of activated mutant alleles of SOS2 reveals a critical requirement for its kinase activity and C-terminal regulatory domain for salt tolerance in Arabidopsis thaliana

In Arabidopsis thaliana, the calcium binding protein Salt Overly Sensitive3 (SOS3) interacts with and activates the protein kinase SOS2, which in turn activates the plasma membrane Na(+)/H(+) antiporter SOS1 to bring about sodium ion homeostasis and salt tolerance. Constitutively active alleles of SOS2 can be constructed in vitro by changing Thr(168) to Asp in the activation loop of the kinase catalytic domain and/or by removing the autoinhibitory FISL motif from the C-terminal regulatory domain. We expressed various activated forms of SOS2 in Saccharomyces cerevisiae (yeast) and in A. thaliana and evaluated the salt tolerance of the transgenic organisms. Experiments in which the activated SOS2 alleles were coexpressed with SOS1 in S. cerevisiae showed that the kinase activity of SOS2 is partially sufficient for SOS1 activation in vivo, and higher kinase activity leads to greater SOS1 activation. Coexpression of SOS3 with SOS2 forms that retained the FISL motif resulted in more dramatic increases in salt tolerance. In planta assays showed that the Thr(168)-to-Asp-activated mutant SOS2 partially rescued the salt hypersensitivity in sos2 and sos3 mutant plants. By contrast, SOS2 lacking only the FISL domain suppressed the sos2 but not the sos3 mutation, whereas truncated forms in which the C terminus had been removed could not restore the growth of either sos2 or sos3 plants. Expression of some of the activated SOS2 proteins in wild-type A. thaliana conferred increased salt tolerance. These studies demonstrate that the protein kinase activity of SOS2 is partially sufficient for activation of SOS1 and for salt tolerance in vivo and in planta and that the kinase activity of SOS2 is limiting for plant salt tolerance. The results also reveal an essential in planta role for the SOS2 C-terminal regulatory domain in salt tolerance.

[Experimental study on effect of platelet-rich plasma in repair of bone defect]

OBJECTIVE

To study the effect of platelet-rich plasma in the repair of bone defect.

METHODS

Segmental bone defects of 1 cm were created in the mid-upper part of bilateral radius of 24 New Zealand white rabbits. One side was randomly chosen as the experimental side, which was filled with artificial bone with platelet-rich plasma (PRP). The other side filled with artificial bone without PRP as the control. After 2, 4, 8 and 12 weeks of implantation, the gross, radiological, histological observations, and computer graphic analysis were performed to investigate the bone healing of the defect in both sides.

RESULTS

Two weeks after operation, new bone and fibrous tissue formation in both the experimental and the control sides were observed only in the areas adjacent to the cut ends of the host bone, but the amount of new tissue in the experimental side was much more than that in the control side. In the 4th and 8th weeks, the surface of the artificial bone was covered with a large amount of new bones, the artificial bone was bridged tightly with the host bone by callus in the experimental side, while new bone was limited mainly in the cut ends and was less mature in the control side. In the 12th weeks, bone defects were entirely healed in the experimental side, which were covered completely with cortical bone, while new bone formation was only observed in the ends of artificial bone and there were not continuous bone callus on the surface in the control side.

CONCLUSION

Artificial bone with PRP is effective in the repair of segmental bone defects, and PRP could improve the healing of bone defect.

OSM1/SYP61: a syntaxin protein in Arabidopsis controls abscisic acid-mediated and non-abscisic acid-mediated responses to abiotic stress

To identify the genetic loci that control salt tolerance in higher plants, a large-scale screen was conducted with a bialaphos marker-based T-DNA insertional collection of Arabidopsis ecotype C24 mutants. One line, osm1 (for osmotic stress-sensitive mutant), exhibited increased sensitivity to both ionic (NaCl) and nonionic (mannitol) osmotic stress in a root-bending assay. The osm1 mutant displayed a more branched root pattern with or without stress and was hypersensitive to inhibition by Na(+), K(+), and Li(+) but not Cs(+). Plants of the osm1 mutant also were more prone to wilting when grown with limited soil moisture compared with wild-type plants. The stomata of osm1 plants were insensitive to both ABA-induced closing and inhibition of opening compared with wild-type plants. The T-DNA insertion appeared in the first exon of an open reading frame on chromosome 1 (F3M18.7, which is the same as AtSYP61). This insertion mutation cosegregated closely with the osm1 phenotype and was the only functional T-DNA in the mutant genome. Expression of the OSM1 gene was disrupted in mutant plants, and abnormal transcripts accumulated. Gene complementation with the native gene from the wild-type genome completely restored the mutant phenotype to the wild type. Analysis of the deduced amino acid sequence of the affected gene revealed that OSM1 is related most closely to mammalian syntaxins 6 and 10, which are members of the SNARE superfamily of proteins required for vesicular/target membrane fusions. Expression of the OSM1 promoter::beta-glucuronidase gene in transformants indicated that OSM1 is expressed in all tissues except hypocotyls and young leaves and is hyperexpressed in epidermal guard cells. Together, our results demonstrate important roles of OSM1/SYP61 in osmotic stress tolerance and in the ABA regulation of stomatal responses.

Constitutive activation and transgenic evaluation of the function of an arabidopsis PKS protein kinase

A novel family of SOS2 (salt overly sensitive 2)-like protein kinase genes (designated PKSes) have been recently identified in Arabidopsis. The biochemical characteristics as well as in vivo roles of most of the PKSes are unclear at present. In this work, we isolated and characterized one of the PKSes, PKS18. PKS18 was expressed in leaves of mature Arabidopsis plants. The glutathione S-transferase (GST)-PKS18 fusion protein was inactive by itself in substrate phosphorylation. An activation loop Thr(169) to Asp mutation, however, highly activated this kinase in vitro (designated PKS18T/D). Kinase activity of the PKS18T/D preferred Mn(2+) to Mg(2+). The activated kinase showed a substrate specificity, and high catalytic efficiency for a peptide substrate p3 and for ATP. Interestingly, PKS18T/D transgenic plants were hypersensitive to the phytohormone abscisic acid (ABA) in seed germination and seedling growth, whereas silencing the kinase gene by RNA interference (RNAi) conferred ABA-insensitivity, indicating the involvement of PKS18 in plant ABA signaling.

[Influence of preoperative transcatheter arterial chemoembolism on immunity after hepatectomy in patients with liver cancer]

BACKGROUND & OBJECTIVE

Transcatheter arterial chemoembolism (TACE) is one of important therapeutic method for hapatocarcinoma. Post-operative TACE could reduce recurrent rate definitely. However, there were much debate about the function and effect of preoperative TACE. This study was conducted to evaluate the effect of preoperative TACE on immunity of the patients with recurrent hepatocarcinoma who performed combined treatment.

METHODS

The patients with primary hepatocarcinoma who performed operative TACE were collected. The dynamic changes of cellular immunity and humoral immunity in pre-intervention, pre-operation, combined treatment after recurrence periods were determined by flow cytometry and ELISA, and were compared with the data of the recurrent patients after simple operation.

RESULTS

In TACE group: CD3, CD4, CD56 decreased slightly; serum IgM increased slightly, with no significant difference compared to pre-intervention (P < 0.05); At the time of combined treatment after recurrence, CD8 increased and CD4/CD8 decreased (0.8 +/- 0.3%), the immune suppression was slight. In sample operation group, CD3, CD4, CD56 were 49.0 +/- 9.1%, 19.0 +/- 4.8%, 18.6 +/- 9.9%; the immune suppression was severe. The operation significantly decreased the patients' CD3, CD4, and CD19. The pathologic results showed that the tumor capsule, intrahepatic daughter foci, tumor thrombus, and the radical degree in preoperative group were much better than those in simple operation group.

CONCLUSION

The preoperative TACE do not obviously influence the immunity; furthermore, it can relieve the immune depression after operation and is a remedy of the surgical treatment. It is important to grasp the indication of preoperative TACE.

Enhancing the efficiency of Epstein-Barr viral serologic test in the diagnosis of nasopharyngeal carcinoma

OBJECTIVE

To investigate the efficiency of concurrent application of VCA-IgA, EA-IgA and EA-IgG serological tests in diagnosing nasopharyngeal carcinoma (NPC).

METHODS

The sera of 266 untreated NPC patients and 347 healthy adults were collected. In addition to the conventional immunoenzymatic method of VCA-IgA test, enzyme-linked immunosorbent assay (ELISA) was adopted as an alternative to test the antibody level of EA-IgG and EA-IgA. A new statistical formula was used to evaluate the odds ratio of different combinations of these three tests.

RESULTS

The sensitivity and specificity of VCA-IgA, EA-IgG and EA-IgA concurrently were as high as 95.11% and 97.41%, respectively, which were higher than those of single test (90.60% and 94.52% for VCA-IgA, 93.98% and 93.66% for EA-IgG, 89.84% and 88.18% for EA-IgA). Furthermore, the odds ratio of 3-test positivity (1 912.5) was higher than those of 2-test positivity (27.903 2 for VCA-IgA and EA-IgG, 11.169 0 for EA-IgG and EA-IgA, 8.032 8 for VCA-IgA and EA-IgA), which were even higher than those of 1-test positivity (0.121 4 for VCA-IgA, 0.170 5 for EA-IgG and 0.048 8 for EA-IgA).

CONCLUSION

ELISA is more accurate in reflecting the antibody level of EA-IgG and EA-IgA than the conventional immunoenzymatic method. The concurrent application of VCA-IgA, EA-IgG and EA-IgA test can markedly improve the sensitivity, specificity and odds ratio as well, thus resulting in enhancing the efficiency of diagnosing nasopharyngeal carcinoma serologically.

[Stimulation of ozone stress on the adhesion of inflammatory cells to bronchial epithelial cells]

OBJECTIVE

To determine into the inflammation process of bronchial epithelial cells (BECs) and observe the modulatory effect of some protective factors on BECs.

METHODS

We built the cell injury model with ozone and observed the effect of ozone stress on polymorphonuclear loeukocyte (PMNs) and eosinophil (EOS) adhesion to BECs. The effect of intercellular adhesion molecule (ICAM-1) antibody on the adhesion and ICAM-1 protein expression of BECs was observed at the same time.

RESULTS

O3 increased the adhesion of BECs to PMNs and EOS. Adhesion could be blocked by ICAM-1 antibody, suggesting ICAM-1 was the principal molecule leading PMNs and EOS adhesion to BECs. The immunocytochemistry assay indicated that O3 increased the expression of ICAM-1 protein of BECs.

CONCLUSION

Ozone stress leads to inflammation, and the principal adhesion molecule is ICAM-1 resulting in adhesion between BECs and PMNs, and between BECs and EOS.

[Micrometastasis distribution in liver tissue surrounding hepatocellular carcinoma]

OBJECTIVE

To study the micrometastasis distribution in liver tissue surrounding hepatocellular carcinoma (HCC), and provide reference for appropriate surgical safety margin.

METHODS

Thirty-six patients with HCC but without clinical metastasis underwent hepatectomy. Their specimens showing ample surgical margin were made into giant sections. Tumor micrometastasis in liver tissue around the primary tumor were examined microscopically. In each specimen, the surrounding tissue was divided into proximal(p) and distal(d) areas. In either area, three lines of demarcation 0.5 cm, 1.0 cm, and 2.0 cm away from the margin of the primary tumor were designated as L(0.5), L(1.0) and L(2.0). Therefore, the surrounding tissue was divided into six zones - Z(p0.5), Z(p1.0), Z(p2.0) and Z(d0.5), Z(d1.0), Z(d2.0). The maximum micrometastasis spread distance (MMSD) and density (D(p0.5), D(p1.0), D(p2.0) and D(d0.5), D(d1.0), D(d2.0)) in each zone were analyzed after search for micrometastasis in the giant sections.

RESULTS

72.5% (111/153) micrometastases were found in form of microscopic tumor emboli. Their spread distance could be up to 6.1 cm. In 66.7% (24/36) specimens, micrometastases were found in the surrounding tissue. In 91.7% (22/24) of them, the distal MMSD was less than 3 cm. The proximal MMSD was less than 1.5 cm in 92.3% (12/13). The comparison of micrometastasis density in the different zones were D(d0.5) > D(d1.0) > D(d 2.0); D(p0.5) > D(p1.0) > D(p2.0); D(d1.0) > D(p1.0); D(d2.0) > D(p2.0) with significant differences.

CONCLUSION

(1) Micrometastases of HCC exist mainly in form of microscopic tumor emboli, (2) The longer the distance from the primary focus, the lower the micrometastasis incidence, (3) In zones more than 0.5 cm away from the primary focus, tumor micrometastasis incidence is significantly lower in the proximal zones than that in the distal zones and (4) For HCC patients without clinical metastasis, a surgical margin of 3 cm wide in the distal area and 1.5 cm wide in the proximal area may reduce the rate of postoperative recurrence.

[Relationship between expressions of p53, c-erbB2 genes, proliferating cell nuclear antigen and prognosis of patients with ovarian epithelial carcinoma]

BACKGROUND & OBJECTIVE

There were a few reports about the relationship between the expressions of p53, c-erbB2 Genes, and proliferating cell nuclear antigen (PCNA) with the prognosis from the patients with ovarian epithelial carcinoma(EOC). But conclusions were difference because of various methods and samples. This study was designed to investigate the relationship between the expressions of p53, c-erbB2 Genes, and PCNA with the prognosis from the patients with EOC.

MATERIALS & METHODS

A total of 84 female patients with EOC were enrolled in this study, who were hospitalized in Department of Gynecology, Cancer Center, Sun yat-sen University from March 1 1990 to March 31 1994. The expressions of p53, c-erbB-2, and PCNA from the tumor samples were detected by Labelling-streptavidin-biotin (LSAB) immunohistochemistry assay. The relationship between the expression of the above marks and the prognosis of the patients were then analyzed. Statistical analyses were performed using SPSS 8.0 softwave.

RESULTS

Forty-nine tumor samples (58.3%) exhibited p53 overexpression, 65 (77.4%) exhibited c-erbB2 overexpression, and all (100%) exhibited PCNA overexpression. In univariate analysis, there was marginally significant difference in the mean survival, the 5 years survival between the patients exhibited no c-erbB2 overexpression and the patients exhibited any c-erbB2 overexpression (P = 0.05). There was significant difference in the mean survival, the 5 years survival between the patients showed lower expression of PCNA and those showed higher expression of PCNA (P < 0.01), and there was no significant difference in the mean survival, the 5 years survival between the patients with overexpression of p53 and without overexpression of p53 (P > 0.05). In multivariate analysis, only stage and histological grade were the important significant prognostic factors of the patients with EOC, and there was no statistical significance between the overexpression of c-erbB-2 and PCNA with the prognosis.

CONCLUSIONS

There was no significant correlation between the overexpression of p53 gene and the prognosis of the patients with EOC. The expression of c-erbB2 or PCNA was not an independent prognostic factor for prognosis of the patients with EOC. Stage and histological grade were still the independent significant prognostic factors of EOC.

[Resisting injury and protective effect of fibronectin on bronchial epithelial cells]

AIM AND METHODS

To test the hypothesis that activation of integrin molecules play a role on protecting bronchial epithelial cells (BEC) from oxidant injury. Based on a cell-injury model made by ozone (1.5 x 10(-6)) exposure, the present study investigated the protective effect of fibronectin (Fn), a kind of ligand of integrin, and it's specific sequence Arg-Gly-Asp (RGD peptide) which is a recognizable domain for integrin on BEC. 3H release, LDH and MDA were measured as indexes for damage.

RESULTS

(1) Ozone exposure induced a significant increase of 3H release and LDH release from BEC and elevation of MDA. (2) Pretreatment with Fn or RGD before ozone exposure markedly attenuated the release of 3H, LDH and MDA, and the effects of Fn were reversed by W7, a calmodulin inhibitor. (3) Either Fn or RGD up-regulated activity of catalase in BEC and promoted GSH synthesis in BEC.

CONCLUSION

These suggests that the binding of integrin with Fn improve the antioxidant ability of BEC and lighten the damage induced by oxidant attack. The protective mechanism of Fn-integrin binding may be related with calmodulin.

Genome-wide analyses on loss of heterozygosity in hepatocellular carcinoma in Southern China

BACKGROUND/AIMS

To conduct a genome-wide analysis of loss of heterozygosity (LOH) and its clinical significance in hepatocellular carcinoma (HCC) in Southern China where high incidence of HCC was documented.

METHODS

LOH of 382 microsatellite loci on all autosomes were detected with polymerase chain reaction-based microsatellite polymorphism analyses in 104 HCC tumor tissues.

RESULTS

High frequency of LOH (>55.7%) was observed on chromosome 1p, 1q, 2q, 3p, 4q, 6q, 8p, 9p, 13q, 16q, and 17p. LOH rates on loci D4S2964 (4q21.21), D8S277 (8p23.1-pter) and D17S938 (17p13.1-p13.3) were significantly higher in cases with positive HBsAg than in those with negative HBsAg. Similarly, LOH on loci D1S214 (lp36.3), D1S2797 (1p34) and D3S3681 (3p11.2-p14.2) were more frequently detected in tumors with intrahepatic metastasis than in those without.

CONCLUSIONS

Status of LOH in HCC in Southern China is similar to that reported previously in other countries and areas. However, we firstly identified high-frequency LOH on chromosome 3p in HCC. Furthermore, HBV infection, as well as tumor intrahepatic metastasis, may be correlated with allelic losses on certain chromosome regions.

[Integrin-ligands binding reaction upregulates the antioxidant activity of rabbit bronchial epithelial cells]

Antioxidant activity of bronchial epithelial cells (BECs) plays an essential role in preventing the airway epithelium integrity from damage in structure and function. Integrin expressed by BECs is the receptor of extracellular matrix such as fibronectin (Fn), and it is involved in modulation of proliferation, differentiation and metabolism of the cells. In order to test the hypothesis that integrin-ligand binding reaction supports the ability of cells to withstand oxidant attack, the present study evaluated the antioxidant activity of primary cultured rabbit BECs treated with fibronectin or its sequence Arg-Gly-Asp (RGD peptide), by determining changes in the activity of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT) and in the level of glutathione (GSH). The results are as follows: (1) Fn (10 micrograms/ml) increased significantly the activity unit of GSH-Px (P < 0.05, n = 5), which was inhibited by calmodulin-inhibitor W7 (10(-5) mol/L) (P < 0.05). Both Fn (5-20 micrograms/ml) and RGD (15-60 micrograms/ml) showed a dose-dependent upregulatory effect (respectively r = 0.93 and r = 0.73). (2) Treatment with Fn increased SOD activity (P < 0.01, n = 7), which was abolished by W7 (P < 0.01). (3) Catalase activity was also stimulated by Fn (P < 0.05, n = 6) and reversed by W7 (P < 0.01). (4) A dose-dependent increase of GSH level was observed in both Fn (r = 0.82) and RGD treatment (r = 0.84). The data suggest that the binding of integrin with extracellular matrix can upregulate activity of antioxidant enzymes, and increase the content of GSH and improve the ability of BECs to resist oxidant injury.

[Fibronectin or RGD peptide promotes nitric oxide synthesis of rabbit bronchial epithelial cells]

To find out whether the extracellular matrix component fibronectin plays a regulatory and protective role in bronchial epithelial cells, the present study was undertaken to detect the NO released from primary cultured rabbit bronchial epithelial cells (BEC) and the activity of NO synthesase (NOS) in cells. Stress with ozone was taken as the positive control, and the effects of fibronectin (Fn) or its specific sequence Arg-Gly-Asp (RGD peptide) was observed. The results showed: (1) Ozone stress enhanced NO release from BEC, and treatment with Fn also promoted the NO production. The effect of Fn could be blocked by calmodulin inhibitor W(7). (2) Both Fn and RGD showed a dose-dependent promotion on NO release. (3) The NOS activity was significantly elevated in Fn treated group and the effect of Fn was abolished by W(7). A dose-response relation in NOS activity was observed in either Fn treated or RGD treated group. It is concluded that the binding of fibronectin or its specific sequence RGD peptide with integrins of BEC plays a role in upregulating the NOS activity and the NO release, and calmodulin may take part in the pathway of signal transduction.

Elevation of serum vascular endothelial growth factor in male patients with metastatic nasopharyngeal carcinoma

BACKGROUND

Angiogenesis is essential for tumor growth and metastasis. Vascular endothelial growth factor (VEGF) is the most potent angiogenic factor identified to date. The authors investigated the correlation between the levels of serum VEGF (S-VEGF) in patients with nasopharyngeal carcinoma (NPC) and disease progression.

METHODS

The sera from 65 male patients with nonmetastatic NPC, 22 male patients with metastatic NPC, and 27 healthy male volunteers were obtained. A quantitative enzyme-linked immunosorbent assay was performed to measure the concentrations of S-VEGF in the sera.

RESULTS

The mean S-VEGF levels were 371.0 pg/mL(-1) (range, 128.5-691.1 pg/mL(-1)) for healthy controls, 375.6 pg/mL(-1) (range, 72.9-1202.5 pg/mL(-1)) for patients with nonmetastatic NPC, and 958.6 pg/mL(-1) (range, 264.4-3744.9 pg/mL(-1)) for patients with metastatic NPC. The mean S-VEGF level in patients with metastatic NPC was significantly higher than in either patients with nonmetastatic NPC (P < 0.001) or healthy controls (P < 0.001). However, there was no statistical difference between these results for healthy controls and patients with nonmetastatic NPC. At the level of 900 pg/mL(-1), S-VEGF indicated distant dissemination of NPC with a specificity of 95.4%, a sensitivity of 31.8%, a positive predictive value of 70.0%, and a negative predictive value of 80.5%. No significant differences in the levels of S-VEGF were found among various T classifications, N classifications, and clinical stages of nonmetastatic NPC.

CONCLUSIONS

The levels of S-VEGF were significantly elevated in male patients with metastatic NPC. These levels did not correlate with locoregional progression of NPC. The usefulness of detecting S-VEGF in the early diagnosis of NPC appears to be limited.

Study on early frozen section after nerve repair with "cell surgery" technique

OBJECTIVE: To observe the early histological change at the nerve anastomotic sites after using "cell surgery" with conventional microsuture. METHODS: Twenty-two Sprague Dawley rats were divided into three groups: the first group as the control group n=6. The left sciatic nerves were cut using conventional cut method and repaired by either two (n=2) or four (n=4) epineurial stitches of 11-0 monofilament nylon. In the second group of rats, all the experimental procedures were undertaken freezingly and trimingly with a razor blade using sawing movements (n=4) or guillotine-like movements (n=4). The nerve stumps were then brought into apposition and aligned after thawing. A drop of fibrin glue was spread over each of the sites of anastomosis under an operating microscope. For the third group of 8 rats, all the procedures were similar to those of the second group except that glue welding was done after thawing. RESULTS: After the frozen nerves were cut and thawed, the alignment of the disorganized axon became much better at anastomotic sites after fibrin glue welding. Histological sections found that the axonal alignment was good, especially at the central part of the anastomotic sites except a slight disorganization of the peripheral part. The method of glue coaptation before thawing seems to be a better method than that after thawing. CONCLUSIONS: "Cell surgery" technique can improve the nerve repair at the astomotic sites. When we weld the nerve with fibrin glue, coaptation before thawing should be achieved soon.

[Cytoprotective effect of epidermal growth factor on cultured rabbit airway epithelial cells exposed to ozone]

In this study, it was observed that ozone (O3) exposure has cytotoxic effects on cultured airway epithelial cells, which was positively related with exposure duration. Both the production of malondialdehyde (MDA) and the 3H release in the exposure group were much higher than the control (P < 0.01), suggesting that lipoperoxidation occurring in the cell membrane was responsible for the cellular injury observed under O3 attack. EGF at low concentration (5 ng/ml) showed cytoprotective effect on airway epithelial cells exposed to O3 as shown by attenuated MDA production and decrease of 3H release and cytotoxic index (P < 0.01). Pretreatment with EGF could reverse the depletion of intracellular GSH content as a result of O3 exposure and increase the total glutathionein the cells. The above results suggest that the cytoprotection of EGF on airway epithelial cells may be related to its promotive effect on GSH synthesis.

Nonlinear system identification using a Gabor/Hopfield network

This paper presents a method of nonlinear system identification using a new Gabor/Hopfield network. The network can identify nonlinear discrete-time models that are affine linear in the control. The system need not be asymptotically stable but must be bounded-input-bounded-output (BIBO) stable for the identification results to be valid in a large input-output range. The network is a considerable improvement over earlier work using Gabor basis functions (GBF's) with a back-propagation neural network. Properties of the Gabor model and guidelines for achieving a global error minimum are derived. The new network and its use in system identification are investigated through computer simulation. Practical problems such as local minima, the effects of input and initial conditions, the model sensitivity to noise, the sensitivity of the mean square error (MSE) to the number of basis functions and the order of approximation, and the choice of forcing function for training data generation are considered.

[Effect of prolactin on production of acid phosphatase in rat prostatic cells and its mechanism]

The present study revealed the effect of prolactin (PRL) and sex steroid hormones on production of prostatic acid phosphatase (PAP) of the immature rat prostatic epithelial cells in serum-free medium. The results showed that PRL significantly stimulated synthesis and secretion of PAP, but failed to synergize with dihydrotestosterone or estradiol. Dihydrotestosterone or estradiol alone did not promote PAP production. Studies on the mechanism of PRL action indicated that adenyl cyclase was not activated in the action of PRL: Synergistic effect between PRL and prostaglandin E2 and F2 alpha was revealed in the stimulation of PAP production, and the effect of PRL could be blocked by indomethacin (a prostaglandin synthesis inhibitor). In conclusion, PRL directly stimulated PAP production of the cultured rat prostatic epithelial cells in serum-free medium and prostaglandin was involved in PRL action.

Infiltrating lymphocytes and accessory cells in nasopharyngeal carcinoma

The infiltrating lymphocytes (LCs) and accessory cells (ACs) including dendritic cells (DCs) and monocytes/macrophages in nasopharyngeal biopsies taken from 4 groups of nasopharyngeal carcinoma (NPC) patients were observed by using an immunostaining technique and the correlation of the results to the clinical manifestations and follow-up data was examined. The findings were as follows. (1) NPCs without lymph node metastasis always had marked infiltrating LCs and DCs as compared with those with lymph node(s) metastasis. (2) Advanced NPCs with lymph node(s) involvement (T1-4N1-3M0) and a rapid development of distant metastasis followed by death within 1 year after radiotherapy always showed fewer infiltrating LCs and DCs as compared with those with lymph node(s) metastasis (T1-4N1-3M0) and having longer than 5-year survival after radiotherapy. The amount of both LCs and ACs, especially DCs, infiltrating in NPC tissues appears to be an indicator of the activity of host immune defence mechanisms against cancer and influences the progression of the neoplasm as well as the prognosis.