[Clinicopathological and molecular genetic analysis in Chinese typical hereditary nonpolyposis colorectal cancer pedigrees]

OBJECTIVE

To investigate the clinicopathological and molecular genetic characteristics of Chinese hereditary nonpolyposis colorectal cancer (HNPCC) pedigrees.

METHODS

Four Chinese HNPCC pedigrees were studied using microdissection, microsatellite instability analysis, immunohistochemistry staining and direct DNA sequencing for hMSH2 and hMLH1 genes.

RESULTS

All five tumor tissues from 4 probands showed high level of microsatellite instability at more than 2 loci(RER + phenotype). Three of 4 cases lost hMSH2 protein expression and one case showed no hMLH1 protein expression. Three pathological germline mutations (2 on hMSH2 and 1 on hMLH1) were identified.

CONCLUSIONS

Chinese typical HNPCC kindreds showed relatively frequent germline mutations of mismatch repair genes. Microsatellite instability analysis and immunohistochemistry staining might be the effective screening methods before direct DNA sequencing for the detection of mismatch repair genes. It is necessary to establish clinical criteria and molecular diagnostic strategies more suitable for Chinese HNPCC kindreds.

[Research and application of drug controlled release technique in tissue engineering]

OBJECTIVE

To investigate protection of biological activity and controlled release of growth factor by means of drug controlled release technique in tissue engineering.

METHODS

Using drug controlled release technique that to embed or microcapsulate the biological drug with biodegradable polymer.

RESULTS

The aliphatic polylactone could be used as drug carrier for each drug including the biological matter. And the release behavior of the drug could be controlled by adjusting the molecular structure of the carrier and the controlled release method. The successful example, that to realize regeneration of rat's sciatic nerve with 5, 10, 15 and 20 mm of gap by using polylactide as nerve guide and the embedding growth factor, had been obtained.

CONCLUSION

It is possible to realize protection of biological activity and sustained release of growth factor by using aliphatic polylactone as drug carrier.

Insights into molecular mechanisms of contact hypersensitivity gained from gene knockout studies

Contact hypersensitivity (CHS), a dendritic-cell (DC)-dependent, T-cell-mediated skin immune response to reactive haptens, has been a subject of intense research for many years. The molecular mechanisms underlying CHS are complicated and are not fully understood. During the past few years, varieties of gene-targeted knockout mice have been used in the study of CHS. Such studies have contributed significantly to our understanding of the mechanisms responsible for the initiation of CHS. This review focuses on insights into molecular requirements for CHS gained from knockout studies.

[Detection mucin gene in cervical lymph nodes in supraglottic cancer by reverse transcription polymerase chain reaction]

OBJECTIVE

To investigate the efficacy of discovery of cervical lymph nodes micrometastasis of supraglottic carcinomas by detection of mucin (MUC1) gene.

METHODS

Twenty-five supraglottic carcinoma patients with clinically negative lymph nodes were performed neck dissection. MUC1 gene mRNA in these resected lymph nodes was detected by reverse transcription polymerase chain reaction (RT-PCR) and histopathological examination to find the potential micrometastasis.

RESULTS

Of all 93 cervical lymph nodes, micrometastasis were found in 23 nodes of 6 case by histopathological examination and RT-PCR. Four of 19 cases with negative lymph nodes pathologically showed MUC1 gene expression and were identified to have metastasis by clinical recurrence and serial-sectioning. Therefore, the rate of detection of micrometastasis by this way was 16% (4/25), higher than that of regular pathologic methods.

CONCLUSION

Detection of lymph nodes micrometastasis with RT-PCR method was more sensitive than that of regular pathologic methods. It is a valuable method to detect early lymph nodes metastasis.

Preparation of microporous aluminium anodic oxide film modified Pt nano array electrode and application in direct measurement of nitric oxide release from myocardial cells

A novel method for fabricating a nano array electrode (NAE) by using micropores of aluminium anodic film as templates was investigated. To evaluate the NAE, cyclic scanning of NAE in Fe(CN)6(3-) solution was performed and a sigmoidal shaped voltammogram was obtained. The NAE was designed to measure nitric oxide (NO) in vitro and in vivo. Studies showed that it was a sensitive and selective NO electrochemical sensor. NO release from myocardial cells was directly measured with this NAE and the results were satisfactory.

[A new algorithm for displaying the cutting isosurface of structures]

The existing algorithms for displaying the cutting isosurface of the structure are not suitable for interactive display because they spend too much time on calculation when a fair amount of data is submitted to processing. This paper presents a new algorithm for accelerating the cutting of structure by using the area partition and the increment calculation to reduce the unnecessary calculation in cutting the structure. It is suitable for real time interactive displaying, especially in the case of a vast amount of data.

Determination of sulfur dioxide in vitriol plant wastewater by using a polyNiMe4TAA electrochemically modified Pt microelectrode

A Pt microelectrode modified with nickel(II) polytetramethyldibenzo[b,i]tetraaza[14]annulene was prepared by electropolymerization of nickel(II) tetramethyldibenzo[b,i]tetraaza[14]annulene monomers and applied to determine sulfur dioxide in vitriol plant wastewater. For determination of SO2 with this electrochemically modified Pt microelectrode, the linear range was from 9.6 x 10(-6) to 2.4 x 10(-4) mol L-1, the sensitivity was 1.8 x 10(-4) A L mol-1, the detection limit was calculated to be 4.8 x 10(-6) mol L-1 (S/N = 3), the response time was less than 20 s and the relative standard deviation was found to be 2.1% on analyzing 4.8 x 10(-5) mol L-1 SO2 solution repeatedly (n = 7). These results demonstrated good accuracy compared with those obtained by the conventional iodimetric method.

[Vowel selection effects on the parameters of acoustic analysis]

OBJECTIVE

To investigate if there is difference about the parameters of acoustic analysis with the different vowel |a|, |i|, |ae| and decide which vowels is best fitted to the acoustic analysis.

METHOD

40 normal and 130 pathologic voice patients accepted acoustic analysis. Each acoustic parameters such as jitter, shimmer, NNE, SDF0, SNR were compared with different vowels.

RESULT

Jitter, shimmer, NNE with |i| were much lower than that with |a| and |ae| in normal cases and light hoarseness group. While the acoustic parameters with |i| were much higher than that with |a| and |ae| in moderate and heavy hoarseness group.

CONCLUSION

|a| and |ae| were the preferred vowels for normal and light hoarseness group, while the |i| could supply some useful suggestion for the moderate and heavy hoarse patients.

[Experimental studies of the protective effects of basic fibroblast growth factor and Radix Salviae Miltiorrhizae on brain injury in rats caused by repeated exposures to +Gz]

Objective. To investigate the preventive and theralseutive (therapeutic) effects of basic fibroblast growth factor (bFGF) and Radix Salviae Miltiorrhizae (RSM) on brain injury caused by repeated +Gz exposures. Method. bFGF and RSM were injected intraperitoneally into SD rats before and after repeated +Gz exposures. The contents of excitatory amino acids (EAAs), nitric oxide (NO) and the number of cell apoptosis in the brain were measured, and were compared to those of the control group and normal saline (NS) group. Result. The contents of EAAs, NO and the number of cell apoptosis were significantly higher in repeated +Gz exposures group than those in control group. The values were markedly lower in bFGF and RSM group than those in repeated +Gz exposures group and NS group. Conclusion. bFGF and RSM showed distinct preventive and therapeutic effect on the brain injury induced by repeated +Gz exposures.

[Detection of enterotoxin genes in Bacillus thuringiensis by PCR]

The presence of hemolysin HblA (hblA), enterotoxin BceT (bceT) and enterotoxin S (entS) genes from 45 strains of B. thuringiensis, 4 strains of B. cereus and B. sphaericus have been detected respectively by multiple PCR. The results showed that 95.6% B. thuringiensis strains contain the B component of hblA gene, 91.1% and 93.3% of them contain bceT and entS genes sequences respectively. The enterotoxin productions in all strains have also been analysis using two commercial immunoassay kits(TECRA and RPLA) and it has proved that most of B. thuringiensis stains and the positive B. cereus strain can produce entero toxins during their growth. However, the two hblA sequence positive stains, DBT007 was negative when tested both by RPLA and Tecra, T24 001 was negative when assayed by Tecra and positive by RPLA. One hblA sequence negative strain Dmu39 was negative when tested by RPLA but positive by Tecra. No enterotoxin and enterotoxin gene could be detected in B. thuringiensis DBT248 and the B. sphaericus strains. The results suggest that the potential risk of using B. thuringiensis, as biopesticide needs to be further evaluated.

[Multi-resolution blending rendering of the medical structure]

This paper presents a new medical data visualization method called multi-resolution blending rendering which has been developed for visualizing the large medical volume data sets. Different from those multi-resolution rendering methods which simplify the structures by polygon mesh optimization technique, the new method uses different resolution levels to represent different parts of a structure at the same time. So, it can preserve the integrality of the structure and emphasize the important part of the structure when simplifying the structure. The new method also takes advantage of the good qualities of the wavelet transform and constructs the multi-resolution blending model of the structure by orthogonal wavelet transform and transition operator. The experiment proves that our method can effectively simplify the model of the structure, enormously reduce the number of the triangle of the structure and speed up the structure rendering. It is especially suitable for interactive observations on a complex medical structure.

Astragali and Angelica protect the kidney against ischemia and reperfusion injury and accelerate recovery

OBJECTIVE

To investigate the role of Astragali and Angelica (A&A) of Chinese herbs in acute renal ischemia/reperfusion injury, and the related intracellular signal transduction mechanism.

METHODS

Acute ischemic renal injury in rats was induced by clamping in renal pedicel for 45 minutes. Rats in therapy group were given a single dose (2 ml/day) of A&A for 3 days before clamping, and then continued for another 3 days. Forty-five minutes after clamping and at different reperfusion time, serum creatinine (Scr) and renal pathological changes were taken and compared in both groups. The proliferating cell nuclear antigen (PCNA) positive cells were detected by immunohistochemistry. Extracelluar regulating kinase (ERK) and c-Jun N-terminal kinase (JNK) activity was assayed by specific substrate phosphorylation with immunoprecipitation.

RESULTS

At the 24th hour of reperfusion, Scr was lower in A&A group than that in the control. Much less necrotic tubular cells, casts, and more PCNA-positive cells were found in A&A group. ERK activity decreased after clamping, and recovered at 5 minutes of reperfusion. There was no difference between the two groups. JNK activity did not change after ischemia, but increased at 5 minutes and peaked at 20 minutes of reperfusion. JNK activity was significantly higher in A&A group than that in the control group.

CONCLUSION

A&A protected kidney against ischemic insult and accelerated both functional and histological recovery after acute renal ischemia/reperfusion injury, which may associate with the change of JNK signaling pathway.

[Chromosome t (8; 21) and t (15; 17) in a patient with acute myeloid leukemia]

OBJECTIVE

To report an acute myeloid leukemia (AML) patient with both chromosome t (8; 21) and t (15; 17).

METHODS

Chromosome specimen was prepared by short-term culture of bone marrow cells, karyotype analyses by R-banding technique, and fusion genes by reverse transcriptase-polymerase chain reaction (RT-PCR).

RESULT

Karyotype analyses showed the appearance of 45, X, -X, t (8; 21), t (15; 17), and RT-PCR assay revealed AML1/ETO and PML-RARalpha fusion gene transcripts.

CONCLUSION

AML with both t (8; 21) and t (15; 17) might be recognized as a a novel subtype of acute leukemias.

Ultrafast formation of nonemissive species via intermolecular interaction in single crystals of conjugated molecules

We investigate the influence of interchain interactions on the photoluminescence processes in a sexithiophene single crystal by applying hydrostatic pressure. We perform transient photoluminescence spectroscopy in the time domain of 100 fs for pressures up to 60 kbar. The combined use of steady-state and time-resolved optical spectroscopies allows us to show that the pressure-induced quenching of the photoluminescence is caused by an ultrafast (approximately 100 fs) formation of intermolecular species.

[The relationship between acoustic analysis and auditory assessment]

OBJECTIVE

To investigate the relationship between acoustic analysis and auditory assessment of hoarseness.

METHOD

24 normal and 154 cases of pathological voice were included in this research. They were divided into 4 groups with different hoarseness and were accepted acoustic analysis. The parameters were analyzed by SPSS statistical software.

RESULT

There were significant difference on acoustical parameters among each group excluding no difference of the jitter between normal and light hoarseness. NNE and SNR were the major parameters in descriptive of hoarseness. There were good correlation between 5 parameters and hoarseness assessment.

CONCLUSION

Acoustic analysis is a useful method in clinical application to assess hoarseness with objective and simple advantage.

Cloning and Expression of the Binary Toxin Gene from Bacillus sphaericus IAB872 in a Crystal-Minus Bacillus thuringiensis subsp. israelensis

Bacillus sphaericus IAB872 has high toxicity against susceptible Culex spp. and medium larvicidal activity against binary toxin-resistant Culex spp. Sequence analysis revealed that the sequence of the binary toxin gene from IAB872 was totally identical to that of the reference strain 2362. The recombinant plasmids were introduced into an acrystalliferous B. thuringiensis strain 4Q7, and the resulting transformants produced parasporal inclusion composed of 51 kDa and 42 kDa proteins during sporulation. SDS-PAGE and Western blot further confirmed that B. thuringiensis transformants were able to express the binary toxin in a high level. Toxicity bioassays showed that they performed high toxicity to susceptible Culex spp. larvae, but no toxicity to resistant Culex larvae. It was, therefore, suggested that other unknown toxins perhaps existed in the wild strain IAB872 except the binary toxin. Their modes of action might be different from that of binary toxin, and they were possibly responsible for the activity of the wild strain IAB872 against resistant mosquito larvae.

Association of coagulation factor VII with the risk of myocardial infarction in the Chinese

OBJECTIVE

To elucidate the association of plasma factor VII coagulant activity (FVIIc) with the risk of myocardial infarction (MI) and to assess the influence of factor VII gene MspI polymorphism and lipid metabolism on FVIIc in the Chinese.

METHODS

A total of 137 patients with angiographically confirmed MI and 125 healthy individuals were evaluated retrospectively. Plasma FVIIc was measured by one-stage prothrombin time, and FVII genotype was determined after MspI digestion of polymerase chain reaction-amplified genomic DNA. Serum lipid levels were assessed by routine methods.

RESULTS

MI patients had significantly higher levels of FVIIc (119.5% +/- 22.7% vs 99.9% +/- 21.8%, P < 0.01) and total serum cholesterol (5.80 +/- 1.06 mmol/L vs 5.53 +/- 1.08 mmol/L, P < 0.05) than controls, but only FVIIc independently correlated with the risk of MI (OR = 1.04, P < 0.01). There were no significant differences in FVII genotype or allele frequency between patients and controls (P > 0.05). Subjects with the Gln353 allele were associated with significantly lower FVIIc levels than Arg353 homozygotes (99.7% +/- 19.3% vs 111.4% +/- 24.6%, P < 0.05). Serum triglyceride was positively correlated with plasma FVIIc in both control (r = 0.25, P < 0.01) and case (r = 0.87, P < 0.01) groups, but this correlation was restricted to Arg/Arg genotype (r = 0.68, P < 0.01). A significant correlation of total serum cholesterol with FVIIc only appeared in Arg/Arg homozygotes (r = 0.17, P < 0.01).

CONCLUSIONS

Our findings support the role of plasma FVIIc as a risk factor for MI in Chinese. Plasma triglyceride and FVII gene MspI polymorphism are two independent determinants of FVIIc. Assay of this polymorphism will be helpful in determining who will benefit most from lipid-lowing therapy.

Lymphangiogenesis in tumor tissues and 5'-Nase, Flt-4, Flk-1 expressions

OBJECTIVE

To investigate lymphangiogenesis in tumor tissues and 5'-Nase, Flt-4, Flk-1 expressions.

METHODS

5'-Nase and Aplase expressions and the morphology of lymphatics in gastric carcinoma tissues were observed with enzyme histochemistry. Flt-4 and Flk-1 expression in gastric carcinoma and sarcoma tissues was studied by immunohistochemistry. CNE-2z cells were implanted into the subdermal layer of nude mice and hyaluronic acid was injected at the same sites. After 4 or 5 weeks, nasopharyngeal carcinoma (NPC) xenograft tissues were cut for immunohistochemistry and enzyme histochemistry, and lymphangiogenesis, 5'-Nase, Alpase, Flt-4 and Flk-1 expression in NPC tissues was studied. Hyaluronic acid contents in sera of the patients with NPC and mice with NPC xenografts were measured by radioimmunoassay.

RESULTS

There were a lot of lymphatics and solid strip-like tissues in gastric carcinoma and NPC xenograft treated with hyaluronic acid. The total number of lymphatics (26.9 +/- 14.2/HP) increased significantly in gastric carcinoma tissues. Flt-4 and Flk-1 positive expression was found in gastric carcinoma, sarcoma tissues and NPC xenograft. Most of the vessels with positive Flt-4 were lymphatics. Flk-1 expression was only found in the walls of blood vessels. Hyaluronic acid content (363.52 +/- 98.15 ng/ml) in sera of patients with NPC was higher than that of the patients with chronic nasopharyngeal inflammation (306.29 +/- 27.15 ng/ml), with a significant difference (P = 0.039). The hyaluronic acid content in sera of nude mice with NPC (2120.59 +/- 490.22 ng/ml) was markedly higher than that in normal mice (1588.99 +/- 502.12 ng/ml), with a significant difference between them (P = 0.007).

CONCLUSION

There are a lot of lymph capillaries with positive 5'-Nase in gastric carcinoma and NPC xenograft treated with hyaluronic acid. Flt-4 positive expression is shown in gastric carcinoma, sarcoma tissues and NPC xenografts. The results suggest there is lymphangiogenesis in these malignant tumor tissues. Hyaluronic acid contents in sera of patients with NPC and nude mice with NPC increase, which may promote the formation of lymphatics.

Synthesis and degradation of a tri-component copolymer derived from glycolide, L-lactide, and epsilon-caprolactone

A series of tri-component copolymers was synthesized by ring opening copolymerization of cyclic lactones, i.e. glycolide, L-lactide, and caprolactone, using stannous octoate as a catalyst. Various techniques, including FT-IR, 1H NMR, DSC, X-ray diffraction, tensile strength, and contact angle measurements, were used to elucidate structural characteristics, thermal behavior, mechanical properties, and hydrophilicity of the resulting copolymers. Data showed that the properties of these copolymers could be modulated by adjusting the composition of the copolymers. The DSC and X-ray analysis demonstrated amorphous structures for most of the PGLC copolyesters. The degradation behavior of these PGLC copolymers had been studied in vitro, i.e. in 0.10 M pH 7.4 phosphate buffer solution (PBS). The degradation was monitored by intrinsic viscosity and weight loss measurements. SEM and GPC were also used to monitor the morphology and molecular weight change during degradation. The PGLC copolymers were shown to have variable degradation rates, and most of them could disappear within a few months due to their amorphous structure and low glass transition temperature.

[Changes of mRNA expression of IL-1beta and TNF-alpha in rat brains after repeated exposures to +Gz]

Objective. To study changes of mRNA expression of IL-1beta and TNF-alpha in rat brains after repeated exposures to +Gz. Method. Twenty conscious SD rats served as the subjects. They were randomly divided into 5 groups. Using an animal centrifuge, control rats (n = 4) were exposed to +1 Gz and experimental rats (n = 16) were exposed to +14 Gz three times, each for 45 s with 30 min interval in between. The rat brains were taken 30 min, 6 h, 24 h and 48 h after the last centrifuge run and total RNA was isolated. mRNA expression levels of IL-1beta and TNF-alpha in rat brain were measured by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). Result. mRNA expression levels of IL-1beta and TNF-alpha in rat brains taken 30 min, 6 h and 24 h after repeated +Gz exposures were significantly higher than those in control rats, but returned to normal after 48 h. Conclusion. It suggested that mRNA expressions of IL-1beta and TNF-alpha in rat brains can be stimulated by repeated +Gz exposures and the increased expression of IL-1beta and TNF-alpha may play a role in the pathologic course of brain damage induced by +Gz exposures, but the damage is reversible.

Interleukin-12 and Flt3 ligand differentially promote dendropoiesis in vivo

Interleukin-12 (IL-12) and Flt3 ligand (FL) regulate hematopoiesis by stimulating proliferation, differentiation and migration of progenitor and/or stem cells. In this study, we evaluated the in vivo effect of IL-12 alone or in combination with FL on dendritic cell (DC) generation and accumulation in murine spleen, lymph node, thymus, liver, and tumor tissues. Both cytokines induced accumulation of functional DC in lymphoid and non-lymphoid tissues. IL-12 promoted predominantly myeloid dendropoiesis, while FL induced both myeloid and lymphoid dendropoiesis. Combination treatment resulted in a dramatic increase in CD86+, and particularly, NLDC-145+ cells within the liver, which was largely due to cell proliferation. Combination therapy also revealed the ability of FL to protect bone marrow cell populations from IL-12-induced depletion in vivo. In vitro, we found a significant FL-induced up-regulation of IL-12 production by DC at both mRNA and protein levels. Thus, our study suggests that (i) the antitumor activity of IL-12 may, at least in part, be mediated by the stimulation of dendropoiesis and (ii) IL-12 might contribute to the antitumor activity of FL. Furthermore, induction of DC generation in vivo by a combination of IL-12 and FL might become a new approach for immunotherapy of cancer.

[A study of apoptosis and related gene bcl-2 and p53 expression in hippocampus of rats exposed to repeated +Gz]

Objective. To investigate the role of apoptosis in mechanisms of brain damage induced by +Gz exposures. Method. Twenty conscious SD rats were randomly divided into 5 groups. Rats in the control group (n=4) were exposed to +1 Gz and rats in the 4 experimental groups (n=16) were exposed to +14 Gz for three times, each for 45 seconds with 30 min interval in between. All the +Gz exposured were on an animal centrifuge. The rat brains were taken 30 min, 6 h, 24 h and 48 h after the last centrifuge run and fixed and embedded. The apoptosis and expression changes of related gene bcl-2 and p53 were detected by terminal deoxynucleotide (correction of deoxynuleotide) transferase-mediated dUTP nick end labeling (TUNEL) technique and immunohistochemical method, respectively. Result. Apoptotic cells and expression changes of bcl-2 and p53 were observed in CA1 subregion of rat hippocampus taken 6 h after repeated +Gz exposures, but returned to normal after 24-48 h. Conclusion. It suggests that apoptosis and expression changes of bcl-2 and p53 in rats hippocampus can be induced by repeated +Gz exposures and the apoptosis is one of the molecular mechanisms of brain damage induced by repeated +Gz exposures.

Cytokine-mediated protection of human dendritic cells from prostate cancer-induced apoptosis is regulated by the Bcl-2 family of proteins

Prostate cancer is the most common cancer in men in the United States, and second in cancer-induced mortality. It is likely that tumour-induced immunosuppression is one of the reasons for low treatment efficacy in patients with advanced prostate cancer. It has been recently demonstrated that prostate cancer tissue is almost devoid of dendritic cells (DC), the major antigen-presenting cells responsible for the induction of specific antitumour immune responses. In this study, we have tested the hypothesis that prostate cancer induces progressive suppression of the DC system. We found that co-incubation of human DC with three prostate cancer cell lines led to the high levels of premature apoptosis of DC, which were significantly higher than in DC cultures co-incubated with normal prostate cells or blood leucocytes. Stimulation of DC for 24 hours with CD40 ligand (CD154), IL-12 or IL-15 prior to their co-incubation with prostate cancer cells resulted in a significant increase in DC survival in the tumour microenvironment. Furthermore, activation of DC with these cytokines was also accompanied by increased expression of the anti-apoptotic protein Bcl-x(L) in DC, suggesting a possible mechanism involved in DC protection from apoptotic death. In summary, our data demonstrate that prostate cancer induces active elimination of DC in the tumour microenvironment. Stimulation of DC by CD154, IL-12 or IL-15 leads to an increased expression of the anti-apoptotic protein Bcl-x(L) and increased resistance of DC to prostate cancer-induced apoptosis. These results suggest a new mechanism of tumour escape from immune recognition and demonstrate the cytokine-based approaches which might significantly increase the efficacy of DC-based therapies for cancer.

[Effect of plumular axis-cutted cotton on growth and development of cotton bollworm]

The method of plumular axis cutting was used to induce the resistance of cotton plants to cotton bollworms(Heliothis armigera). The bollworm was cultured in the laboratory, and the effect of induced cotton on the duration of larval development and weights of larvae and pupae was studied. In the treatments of infection and control, the lengths of larval period were delayed by 3 days and 0.5 days, the weights of larvae were decreased by 19.60% and 11.45%, and the pupae weights were decreased by 10.81% and 6.54%, respectively. After the 8 days old larvae were reared with induced cotton leaves for 3 days, the infected and uninfected cutted plants resulted in a decrease of the relative growth rates of larvae by 22.9% and 17.2% respectively, and in a decrease of the relative feeding rates by 26.1% and 21.4% respectively. It is suggested that plumular axis cutting could induce the resistance of cotton plants to bollworm, and influence the growth and development speed of bollworms through retarding their feeding and digestion. Combining with the treatment of Pseudomona gladioli D-2251 strain could obviously increase the insect-resistance of cotton plants.

[Changes of plasma nitric oxide and tumor necrosis factor-alpha in lung elastase injury induced inflammatory response of hamster]

OBJECTIVE

To investigate the role of the NO and TNF-alpha in lung elastase injury induced inflammatory response of hamster.

METHODS

Lung elastase injury induced inflammatory hamster model was established. NOS activity in airway epithelial cells and lung monocytes/macrophage, as well as the serum content of NO and TNF-alpha were measured respectively.

RESULTS

The results indicated that iNOS activity in epithelium and monocytes/macrophages were significantly enhanced. In the early period of inflammation the NO and TNF-alpha content in serum increased obviously and maintained in a high level (P < 0.001).

CONCLUSIONS

This Study suggested that both NO and TNF-alpha are important mediators participating in the lung elastase injury-induced inflammatory response. Our data suggested NO might play a regulatory role in the release of TNF-alpha.

[Utilization of municipal sludge in agriculture and sustainable development]

Based on the ideas of sustainable development, this paper analyzed the features and disposal situations of municipal sludge and its influence on agricultural and urban development. It is suggested that the land application of municipal sludge is significant and urgent for urban and agricultural sustainable development. Land application of sludge will also be basic outlet for sludge disposal in the future. The key of land application of sludge lies in controlling the content of toxic pollutants in sludge and utilizing sludge scientifically.

Double labeling immunoelectron microscopic study on the synaptic connections between glutamic acid neurons and GABA neurons in the hippocampus of rats

In order to explore the roles of different neurotransmitters in epileptic pathogenesis, the synaptic connections between glutamic acid (Glu) neurons and GABA neurons in normal rat hippocampus were studied by pre-embedding double labeling immunoelectron microscopy. The GABA immunoreaction was first demonstrated by chromogen DAB, then the Glu immunoreaction was demonstrated by molybdic acid-TMB method. After being stabilized by DAB-cobalt chloride, the sections were processed for electron microscopic embedding. Under electron microscope, there were many Glu immunoreaction-positive neurons in the pyramidal layer of hippocampal CA1 area and some GABA immunoreaction-positive neurons with pyramidal or polygonal perikarya in the pyramidal, polymorphic and radiant layer of CA1 area. There were also symmetric dendro-axonic synapses formed by GABA-positive dendrites and Glu-positive axons in the polymorphic layer and symmetric axo-dendrites synapses formed by GABA-positive axons and Glu-positive dendritic in the radiant layer. In addition, there were symmetric autoregulatory axo-dendritic synapses between Glu-positive axons and dendrites and autoregulatory axo-axonic synapses (both symmetric and asymmetric) between GABA-positive axons. Above mentioned results, for the first time, showed that there were complex synaptic regulatory relationships between excitatory Glu neurons and inhibitory GABA neurons in the hippocampal CA1 area, thereby, providing ultrastructural evidence for different neurotransmitters participating in epileptic pathogenesis.

Anthropogenic impacts to large lakes in China: the Tai Hu example

The objective of this study is to summarise limnological effects of cultural eutrophication in some Chinese lakes. Detailed data are shown for Lake Tai Hu as an example for a very large shallow lake affected by anthropogenic impacts. Urban and industrial waste water discharged to the lake result in high nutrient concentrations, large algal blooms dominated by cyanobacteria, mainly species of Microcystis and strong horizontal gradients. Algal growth in this lake is mainly ligh and/or phosphorus limited. This situation is typical for most of the lakes included in this review although some of the large deep lakes seem to be nitrogen deficient. In some cases toxicological effects may be the reason for observed discrepancies. Lakes are of vital importance for populations in China as drinking water and nutritional resources. To prevent water shortage because of conflicting usage, anticipation, control and management of water pollution is urgently needed. Moreover, efforts must be taken to rehabilitate deteriorated freshwater ecosystems.

Tamoxifen-induced transient multifocal hepatic fatty infiltration

Tamoxifen is one of the most commonly used anticancer medications. Hepatic damage secondary to tamoxifen treatment is rare. Tamoxifen-induced multifocal hepatic fatty infiltration has not been reported previously. This report describes one case of steatohepatitis caused by tamoxifen in an elderly woman with a history of breast cancer. The patient had multifocal hepatic fatty infiltration secondary to tamoxifen therapy. After tamoxifen was discontinued, the features of multifocal hepatic fatty infiltration on CT improved dramatically, and hepatic transaminases normalized.

Antitumor activity and pharmacokinetics of a mixed-backbone antisense oligonucleotide targeted to the RIalpha subunit of protein kinase A after oral administration

Overexpression of the RIalpha subunit of cAMP-dependent protein kinase (PKA) has been demonstrated in various human cancers. PKA has been suggested as a potential target for cancer therapy. The goal of the present study was to evaluate an anti-PKA antisense oligonucleotide (mixed-backbone oligonucleotide) as a therapeutic approach to human cancer treatment. The identified oligonucleotide inhibited the growth of cell lines of human colon cancer (LS174T, DLD-1), leukemia (HL-60), breast cancer (MCF-7, MDA-MB-468), and lung cancer (A549) in a time-, concentration-, and sequence-dependent manner. In a dose-dependent manner, the oligonucleotide displayed in vivo antitumor activity in severe combined immunodeficient and nude mice bearing xenografts of human cancers of the colon (LS174T), breast (MDA-MB-468), and lung (A549). The routes of drug administration were intraperitoneal and oral. Synergistic effects were found when the antisense oligonucleotide was used in combination with the cancer chemotherapeutic agent cisplatin. The pharmacokinetics of the oligonucleotide after oral administration of (35)S-labeled oligonucleotide into tumor-bearing mice indicated an accumulation and retention of the oligonucleotide in tumor tissue. This study further provides a basis for clinical studies of the antisense oligonucleotide targeted to the RIalpha subunit of PKA (GEM 231) as a cancer therapeutic agent used alone or in combination with conventional chemotherapy.

Expression of HSP70 gene in rat brain after exposures to repeated +Gz

OBJECTIVE

To study the changes of mRNA expression of heat shock protein 70 (HSP70) in the rat brain exposed to repeated +Gz.

METHOD

The mRNA expression levels of HSP70 in rat brain were measured by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR).

RESULT

The HSP70 mRNA expression levels in rat brains taken 30 min and 6 h after repeated +Gz exposures were significantly higher than those in control group, while the difference between the levels of control group and those of experimental rat brains taken 24 h after +Gz exposure was not significant.

CONCLUSION

It is suggested that HSP70 mRNA expression in rat brain can be induced by repeated +Gz exposures and the increased HSP70 mRNA expression may play an important role in self-protection against brain damage induced by +Gz exposures.

[Determination of columbianetin, columbianetin acetate and osthol in Angelica pubescens Maxim. f. biserrata Shan et Yuan by HPLC]

OBJECTIVE

To develop a method for the determination of columbianetin, columbianetin acetate and osthol in Angelica pubescens f. biserrata

METHOD

HPLC method, ODS column (6.0 mm x 150 mm) with a mobile phase of methanol-acetonitrile-0.025 mol.L-1 phosphoric acid (32:20:48), and wave length detection at 320 nm.

RESULT AND CONCLUSION

The method can be used for the quality control of raw medicinal materials.

[Effects of EB virus LMP on the differentiation and growth of human nasopharyngeal carcinoma cell line CNE1]

OBJECTIVE

To study the effects of EBV-LMP gene on differentiation and growth of human nasopharyngeal carcinoma (NPC) cell.

METHODS

With NPC cell line (CNE1) as target, electroporation was used to transfect EBV-LMP gene and the vector into CNE1 cells. The proliferation changes of transfectants were measured in vitro by proliferation experiment. FCM method and transplantation in nude mice were used.

RESULTS

LMP promoted the growth ability of NPC CNE1 cells in vitro. The average A ratio (3.98 +/- 0.11) in the treatment group was higher than in the control group (2.36 +/- 0.05) and also in the negative control group (2.75 +/- 0.07, P < 0.01). Clone forming test (25.2%, 378/1 500) in the treatment group was higher than in the control groups (11.2%, 168/1 500) and negative control groups (13.4%, 201/1 500). When FCM method was used, the keratin positive rate (82.7%) in the treatment group was markedly decreased as compared with the control (92.5%) and negative control groups (95.7%, P < 0. 05). Latent period (26.6 +/- 7.7) days and internal double time (2.51 +/- 0.18) days of transplant tumor of the treatment group were markedly shortened, tumor take rate (5/6) was increased, cells of the transplant tumor in the treatment group showed an image of small size, great allotype, and a trend of low differentiation.

CONCLUSION

The EBV-LMP can promote the growth and inhibit the differentiation of NPC CNE1 cells. EBV-LMP may play an important role in the development of NPC and in studying its mechanism.

Acute hepatitis due to fluoxetine therapy

Fluoxetine-induced hepatotoxicity is generally considered of minimal clinical importance and is not well recognized. Asymptomatic increases in liver enzyme values have been observed in 0.5% of patients who take long-term fluoxetine therapy. This report details 2 cases of acute hepatitis believed to be caused by fluoxetine. Three cases of acute hepatitis caused by fluoxetine have been reported previously. The mechanism of fluoxetine-induced hepatotoxicity is unknown. Although routine monitoring of liver function may not be cost-effective, physicians should be alert to the possibility of fluoxetine-associated hepatitis and consider early discontinuation of the drug if this condition is suspected.

Effect of aspirin on protein binding and tissue disposition of oligonucleotide phosphorothioate in rats

Pharmacokinetic studies of phosphorothioate oligodeoxynucleotides (PS-oligonucleotides) in animals show that following intravenous administration, PS-oligonucleotide clears out rapidly from the plasma and is distributed to majority of the organs. PS-oligonucleotides are bound to plasma proteins extensively. This study was aimed to determine the effect of aspirin, a commonly used drug, on pharmacokinetics of PS-oligonucleotides. In the present study, PS-oligonucleotide was administered to rats that had received aspirin by gavage. Pharmacokinetic study shows that if PS-oligonucleotide was administered following aspirin administration in rats, a) plasma pharmacokinetic parameters (t1/2alpha?, t1/2beta, AUC, etc.) had lower values, b) tissue disposition was different, and c) rate and route of elimination was affected in animals compared to rats receiving PS-oligonucleotide alone. This finding suggests that pharmacokinetics of PS-oligonucleotides can be affected with certain class of drugs, which may have direct impact on biological activity and safety.

Alterations of antioxidant enzymes and oxidative damage to macromolecules in different organs of rats during aging

Oxygen free radicals have been hypothesized to play an important role in the aging process. To investigate the correlation between the oxidative stress and aging, we have determined the levels of oxidative protein damage and lipid peroxidation in the brain and liver, and activities of antioxidant enzymes in the brain, liver, heart, kidney, and serum from the Fisher 344 rats at ages of 1, 6, 12, 18, and 24 months. The results showed that the level of oxidative protein damage (measured as carbonyl content) in the brain and liver was significantly higher in older animals than in young animals. No statistical difference was observed in the lipid peroxidation of the liver and brain between young and old animals. The activities of antioxidant enzymes in most tissues displayed an age-dependent decline. Superoxide dismutases in the heart, kidney, and serum, glutathione peroxidase activities in the serum and kidney, and catalase activities in the brain, liver, and kidney, significantly decreased during aging. Cytochrome c oxidase, an enzyme involved in electron transport in mitochondria, initially increased, but subsequently decreased in the aged brain, whereas no significant alteration was observed in the liver mitochondrial antioxidant enzymes. The present studies suggest that the accumulation of oxidized proteins during aging is most likely to be linked with an age-related decline of antioxidant enzyme activities, whereas lipid peroxidation is less sensitive to predict the aging process.

Tamoxifen reduces endogenous and UV light-induced oxidative damage to DNA, lipid and protein in vitro and in vivo

We have investigated the effect of tamoxifen (TAM) on endogenous or ultraviolet radiation (UVR)-induced oxidative damage to macromolecules in vitro and in vivo. In a system containing calf thymus DNA exposed to a germicidal UV lamp, both TAM and 4-hydroxytamoxifen (4-OH-TAM) inhibited UVR-induced the formation of 8-hydroxy-2'-deoxyguanosine (8-OHdG) in DNA in a dose-dependent manner. At low concentrations, 4-OH-TAM quenched 8-OHdG more potently than TAM. However, the reduction of 8-OHdG by TAM and 4-OH-TAM became similar at a concentration of 10 microM. In contrast, ascorbic acid had the similar effect to TAM, whereas glutathione exhibited little effect on UVR-induced 8-OHdG. The order of quenching efficacy was: 4-OH-TAM > TAM approximately = ascorbic acid > glutathione. We have further determined the effect of TAM on endogenous 8-OHdG formation, lipid peroxidation, and protein oxidation in the skin of SENCAR mice. Topical application of 5 micromol TAM significantly reduced the level of 8-OHdG in mouse epidermis by approximately 27% (P < 0.05). Endogenous lipid peroxidation and protein oxidation, measured as malondialdehyde (MDA) and carbonyl groups, were also substantially reduced by topical TAM. Further study was conducted to evaluate the effect of TAM on UVR-induced 8-OHdG and MDA in skin of hairless mice. In mice subacutely exposed to low dose (3.4 kJ/m2 x six doses) and high dose (16.8 kJ/m2 x three doses) of UVB irradiation, TAM significantly blocked the formation of 8-OHdG in mouse epidermis by 57-81% and MDA by 37-65%, respectively. Our studies suggest that reduction of oxidative damages to biological macromolecules in vitro and in vivo may at least in part explain the anti-carcinogenic and chemopreventive actions of tamoxifen.

Sporadic cases of hemorrhagic colitis associated with Escherichia coli O157:H7 in rural Wisconsin

The epidemiology and clinical aspects of Escherichia coli O157:H7 (E. coli O157:H7) infections in rural Wisconsin have rarely been reported. In the last six years, 66 cases of E. coli O157:H7 infection were encountered at our institution. Bloody diarrhea was the universal presentation and all cases represented apparent sporadic infection as institutional or community-wide outbreaks were not found in our study. The mean age was 31 (range 7 months to 86 years), 25% less than 10 years old and 60% were female. Most cases were seen in summer and early autumn (88%). Two patients (3%) developed hemolytic-uremic syndrome. Case-fatality rate in this study was 1.5%. Antibiotic treatment and hospitalization did not change the course and outcome of the infection. Routine screening of E. coli O157:H7 during winter time (December and January) may not be necessary in our rural area. The understanding gained from our study might foster better infection control.

Preclinical pharmacology of the natural product anticancer agent 10-hydroxycamptothecin, an inhibitor of topoisomerase I

PURPOSE

10-Hydroxycamptothecin (HCPT) is an indole alkaloid isolated from a Chinese tree, Camptotheca acuminata, and has a wide spectrum of anticancer activity in vitro and in vivo mainly through inhibitory effects on topoisomerase I. HCPT has been shown to be more potent and less toxic than camptothecin and has recently undergone clinical trials. To determine how HCPT might be best used as an anticancer agent, preclinical studies of the pharmacokinetics, tissue distribution, metabolism and elimination of HCPT in rats were undertaken.

METHODS

HCPT was administered to rats by i.v. bolus injection at doses of 1, 3, and 10 mg/kg body weight. HCPT (lactone and carboxylate) and its metabolites in plasma, urine, feces, and various tissues were quantitated by reversed-phase HPLC. Pharmacokinetic parameters were then estimated.

RESULTS

Following i.v. administration at doses of 3 or 10 mg/kg, the plasma concentration-time profile for lactone HCPT could be best described by a three-compartment model, with terminal elimination half-lives of 140.4 and 428.6 min, respectively. A two-compartment model was used to fit the plasma concentration-time curve at 1 mg/kg, with a terminal elimination half-life of 30.5 min. Carboxylate HCPT had a longer half-life than the lactone form of HCPT. During the initial 6 h after dosing, urinary excretion was the major route of elimination, and fecal excretion became the major route of elimination thereafter. HCPT was widely distributed to various tissues including the enterohepatic system, kidney, and bone marrow. The lactone form of HCPT was detectable in various tissues examined up to 72 h after dosing at all the three test doses. HCPT glucuronides were present in plasma, urine, feces and various tissues. No significant toxicity was observed at doses of 1 or 3 mg/kg. Polyuria and hematuria were observed only during the initial 3 h after dosing at 10 mg/kg.

CONCLUSIONS

Prolonged elimination of HCPT in vivo may have a significant impact on its therapeutic effects. HCPT is metabolized to its carboxylate form and glucuronides. Dose-dependent toxicity was observed with i.v. administration of HCPT. The results of this study should be useful in the design of future human trials with this anticancer drug.

IFN-gamma-inducing factor/IL-18 administration mediates IFN-gamma- and IL-12-independent antitumor effects

We evaluated the mechanism of the antitumor effects of mouse rIFN-gamma-inducing factor/IL-18 protein on the growth of mouse tumor cell lines in vivo. Mice received IL-18 before or after challenge with CL8-1, a mouse melanoma cell line. Both regimens significantly suppressed tumor growth and reduced the number of mice with growth of tumor from 60% (3/5) to 20% (1/5). Furthermore, IL-18 administered before and after tumor inoculation completely abrogated the establishment of CL8-1 in all animals. IL-18 administration also significantly suppressed the growth of MCA205, a sarcoma cell line, even when treatment was delayed to 7 days following tumor inoculation. Although IL-18/IL-12 combination therapy had the most significant and immediate antitumor effects, many mice so treated succumbed with markedly elevated serum IFN-gamma levels. The antitumor effects of IL-18 were abrogated almost completely when NK cells were eliminated using anti-asialo GM1 Ab administration, but only marginally impaired in IFN-gamma or IL-12 gene-disrupted mice. Immunohistochemical staining revealed that the number of the CD8+ T cells, but not CD4+ T cells, found at the tumor site was reduced in animals treated with IL-18. These results indicate that IL-18 has potent antitumor effects mediated by CD4+ T cells and NK cells, but in IFN-gamma- and IL-12-independent pathways.

[Study on the physiological activities of the metabolites from Paecilomyces arovirens]

The metabolites of Paecilomyces arovirens exhibited insecticidal activities to many inscct pcsts, including cotton aphid, Aphis gossypii, hawthorn Ispidcr mitc, Tetranychus viennensis and larvae of imported cabbage worm, Pietis rapae. A comparison was made between the metabolites of P. arovirens and naphthyl acetic acid (NAA) in wheat (Triticum aestivum) and water melon (Cucumis sativus) bioassays on their physiological effects. Results demonstrated that some of the metabolites physiological activities of P. arovirens are same to that of NAA, some are different between them. It indicate that there is a new kind or many kinds of plant growth regulator in the metabolites and need further analysized. The results can offer reference for exploiting a new insecticid which not only can control insect pests, but also increase plant growth.

[Antiepileptic effects of nimodipine on penicillin-induced seizures in rats]

Injecting penicillin (PNC) intraperitoneally in Wistar rats, we observed their epileptic behaviour and electroencephalographys. The results showed that nimodipine (NIM), a calcium antagonist, could inhibit the seizures and epileptic discharges significantly. No epileptic action was noted while NIM was injected before PNC. It supports our consideration of NIM as a new sort of nonsedative anticonvulsant in clinical practice.

Upregulation of a novel gene by freezing exposure in the freeze-tolerant wood frog (Rana sylvatica)

A novel gene responsive to freezing exposure was identified among five cDNA clones obtained through differential screening of a cDNA library constructed from liver of frozen wood frogs. The cDNA sequence of this gene, cloned in the recombinant plasmid, pBfFR14, showed no homology to any genes available in the Genbank database. The clone, designated as Fr10, carried a 457 bp cDNA sequence and contained a single open reading frame that could potentially encode a small protein of 90 amino acids with a molecular weight of about 10 kDa, named FR10. The putative protein contained a highly hydrophobic N-terminal region (21 residues) that carries a potential nuclear exporting signal (NES) sequence, LALVVLVIAISGL, similar to the NES found in PKI, an inhibitor of protein kinase A (PKA). A single mRNA transcript with a size of 550 nt was detected when the insert of the pBfFR14 was used as a probe against the Northern blot containing total RNA isolated from wood frog organs. RNA blotting analysis for gene expression in eight organs showed that transcription of the gene was highly induced by 24 h of freezing exposure at -2.5 degrees C in liver and gut, moderately elevated in heart, lung, brain and bladder but showed no change in skeletal muscle and decreased in kidney. A time-course analysis for freezing regulation of gene expression in liver showed that transcript levels were increased by 2-fold in 1 h of freezing exposure and the levels continued to increase up to 3.5-fold over the control after 24 h of freezing exposure, but had returned to control levels after 24 h thawing at 5 degrees C. Gene expression in liver was also up-regulated by whole animal dehydration at 5 degrees C but strongly down-regulated by anoxia exposure, indicating that the gene may respond to cell volume regulatory signals in vivo during natural freezing.

[Study on the molecular epidemiology of diarrhea caused by enterotoxigenic Escherichia coli, using polymerase chain reaction with multiple primer pairs]

A Polymerase Chain Reaction (PCR) method has been developed for detecting Enterotoxigenic Escherichia coli (ETEC). Three different sets of oligonucleotide primer were simultaneously used to amplify the enterotoxin genes of heat-labile (LTh) and heat-stable (STIa and STIb) enterotoxins of ETEC. These primers amplified the 627, 240 or 169 base pair DNA fragments from LTh, STIa and STIb genes of the reference ETEC strains, respectively. Five types of ETEC strains corresponding to the LTh, STIa, STIb, LTh-STIa, or LTh-STIb genotypes were distinguished by a single procedure of PCR, using the mixture of the three sets of primers. There was no cross-reaction with the non-ETEC strains. The lowest detection level was 10 cfu. A total number of 623 stool specimens of diarrheal patients from Shangdong Province induced by E. coli were examined by PCR and the positive rate of ETEC was 40.3%. The results indicated that PCR is a rapid, sensitive and specific method for detecting ETEC.

A novel RNA species from the turtle mitochondrial genome: induction and regulation of transcription and processing under anoxic and freezing stresses

The present study identifies a previously cloned cDNA, pBTaR914, as homologous to the mitochondrial WANCY (tryptophan, alanine, asparagine, cysteine, and tyrosine) tRNA gene cluster. This cDNA clone has a 304-bp sequence and its homologue, pBTaR09, has a 158-bp sequence with a long poly(A)+ tail (more than 60 adenosines). RNA blotting analysis using pBTaR914 probe against the total RNA from the tissues of adult and hatchling turtles revealed five bands: 540, 1800, 2200, 3200, and 3900 nucleotides (nt). The 540-nt transcript is considered to be an intact mtRNA unit from a novel mtDNA gene designated WANCYHP that overlaps the WANCY tRNA gene cluster region. This transcript was highly induced by both anoxic and freezing stresses in turtle heart. The other transcripts are considered to be the processed intermediates of mtRNA transcripts with WANCYHP sequence. All these transcripts were differentially regulated by anoxia and freezing in different organs. The data suggest that mtRNA processing is sensitive to regulation by external stresses, oxygen deprivation, and freezing. Furthermore, the fact that the WANCYHP transcript is highly induced during anoxic exposure suggests that it may play an important role in the regulation of mitochondrial activities to coordinate the physiological adaptation to anoxia.

Differential regulation of the mitochondrial ADP/ATP translocase gene in wood frogs under freezing stress

The gene Aat coding for ADP/ATP translocase (AAT) was cloned from liver of the freeze-tolerant wood frog, Rana sylvatica, via differential screening of a cDNA library from liver of frozen frogs and using probes from control versus frozen frogs. Sequence analysis showed that clone pBfFR07 bearing the AAT cDNA contained a 1318-bp insert with one full-length open reading frame. The deduced amino acid sequence included 317 residues, with 81-86% identities to mammalian AAT. A 1750-nt transcript from the Aat gene was detected using pBfFR07 probe and a putative frog AAT of over 30 kDa was visualized by immunoblotting using a polyclonal antibody raised against chicken AAT. Analysis of liver samples from a time course of freezing showed a maximal 4.5-fold increase in mRNA after 8 h with AAT protein peaking in 24-h frozen frogs. Freezing also induced Aat expression in bladder and lung. In liver, mRNA expression also responded positively to anoxia stress but not to experimental dehydration of the animals. These results suggest that AAT induction during freezing may be stimulated by the ischemia that develops when plasma freezes; changes in AAT may contribute to stabilizing energetics in mitochondrial versus cytosolic pools over freeze/thaw cycles.