[Research on the immunological cause of auricular pseudocyst]

OBJECTIVE

To elucidate the relationship between the auricular pseudocyst and the immunological function of patients.

METHOD

The cyst fluid and blood sample had been detected for contents of IgG, IgA, IgM and complement C3 by radial immunodiffusion, immunocomplex (IC) contents by polyethylene glycol turbidimetry in 55 cases, anti-nuclear antibody (ANA) by immuno-fluorescent technique in 23 cases, extractable nuclear antibody (ENA) by immunotransfer technique in 24 cases. The frozen sections of cyst wall tissue of 24 cases had been detected for immunocomplex by immunoenzyme histochemistric method. The reactions were observed separately between the auricle tissue of healthy white rat, human embryo and cyst fluid, serum of patient and normal serum.

RESULT

Contents of IgG, IgA, IgM and C3 in the cyst fluid were lower than the serum significantly (P < 0.01). No IC, ANA and ENA could been found both in serum and cyst fluid, but reactive immunocomplex was discovered on the auricle cartilagous tissue of patient, immunocomplex also be observed on human embryo aurical tissue when it reacted with cyst fluid, but complex hadn't be found when the auricle tissue of white rat and human embryo reacted with serum of patient and normal people.

CONCLUSION

The reason of auricular pseudocyst may be related with the local autoimmune status of patient.

[Clinical study on the using methods of cisplatin in lung cancer chemotherapy]

BACKGROUND

To compare the therapeutic effectiveness and toxicity between 1-day perfusion and 3-day perfusion of high-dose cisplatin combined chemotherapy for lung cancer.

METHODS

Sixty-four cases of pathologically proved lung cancer were randomized into groups A and B. Group A (32 cases) received cisplatin at d1, and group B (32 cases) received cisplatin at d1-3. Total dosages of cisplatin were same for both groups (100 mg/m²).

RESULTS

Delayed vomiting in group B (40.63%) was significantly lower than that of group A (53.13%) (P<0.05); the early nephrotoxicity rate of group B(25.00%) was lower than that of group A (46.88%), but there was no statistically significant difference between two groups (P>0.05). The therapeutical response was 62.50% in group A, and 68.75% in group B. No significant difference of the chemotherapeutical response was observed between the two groups (P>0.05).

CONCLUSIONS

In the combined chemotherapy of lung cancer, the division administration of high-dose cisplatin can not only guarantee the therapeutic response, but also abate the gastrotoxicity and the nephrotoxicity of cisplatin.

Mutual antagonism of calcium entry by capacitative and arachidonic acid-mediated calcium entry pathways

In nonexcitable cells, the predominant mechanism for regulated entry of Ca(2+) is capacitative calcium entry, whereby depletion of intracellular Ca(2+) stores signals the activation of plasma membrane calcium channels. A number of other regulated Ca(2+) entry pathways occur in specific cell types, however, and it is not know to what degree the different pathways interact when present in the same cell. In this study, we have examined the interaction between capacitative calcium entry and arachidonic acid-activated calcium entry, which co-exist in HEK293 cells. These two pathways exhibit mutual antagonism. That is, capacitative calcium entry is potently inhibited by arachidonic acid, and arachidonic acid-activated entry is inhibited by the pre-activation of capacitative calcium entry with thapsigargin. In the latter case, the inhibition does not seem to result from a direct action of thapsigargin, inhibition of endoplasmic reticulum Ca(2+) pumps, depletion of Ca(2+) stores, or entry of Ca(2+) through capacitative calcium entry channels. Rather, it seems that a discrete step in the pathway signaling capacitative calcium entry interacts with and inhibits the arachidonic acid pathway. The findings reveal a novel process of mutual antagonism between two distinct calcium entry pathways. This mutual antagonism may provide an important protective mechanism for the cell, guarding against toxic Ca(2+) overload.

Rat hepatic natural killer cells (pit cells) express mRNA and protein similar to in vitro interleukin-2 activated spleen natural killer cells

Pit cells are liver-specific natural killer (NK) cells that can be divided into high- (HD) and low-density (LD) subpopulations. The characteristics of pit cells were further investigated in this report. LD and HD pit cells express the specific NK-activation markers gp42, CD25, and ANK44 antigen. LD cells and IL-2-activated NK cells have a high mRNA expression of perforin, granzymes, interferon-gamma, and tumor necrosis factor-alpha. LD pit cells, unlike spleen NK cells, have a weak response to IL-2 with regard to proliferation, cytotoxicity, and production of NK-related molecules. The characteristics of HD cells are intermediate between LD and spleen NK cells. These results show that pit cells, especially LD cells, possess characteristics similar to IL-2-activated NK cells. This is the first evidence on a molecular level that pit cells could be considered in vivo activated NK cells.

[Clinical and pathological characteristics of head and neck malignant melanoma]

OBJECTIVE

To investigate the clinical and pathological characteristics of head and neck malignant melanoma.

METHODS

Sixty-eight cases of head and neck malignant melanoma were reviewed. There were 33 patients with melanoma in the nasal cavity and oral cavity, 35 patients with melanoma in the skin. The age fastigium of the patients was from 41 to 60 years. Surgical specimens in 52 cases and biopsy specimens in 16 cases were studied pathologically. S-100, HMB45 and NSE were examined immunohistochemically.

RESULTS

Histopathology studies showed that the cell morphology was pleomorphic as well as polymorphic both in shape and size of the cells. Immunohistochemical studies helped diagnosis as all of the 42 melanoma specimens were posture for S-100 and 90.5% positive for HMB45. In 52 of the 68 cases, the tumor was excised surgically, with additional radiotherapy in 13 cases or chemotherapy in 21 cases. Ten cases were treated with radiotherapy alone. In 56 patients followed-up, 12 survived for 5 years, including 9 cases of skin melanoma and 3 cases of nasal and oral melanoma.

CONCLUSION

The histo-pathological features of malignant melanoma vary significantly. Immunohistochemical staining helps diagnosis and differential diagnosis. The prognosis of malignant melanoma in nasal cavity and oral cavity is poor as compared to that in the skin of head and neck region.

Healthy pregnancy program in a national managed care organization: evaluation of satisfaction and health behavior outcomes

OBJECTIVE

To evaluate satisfaction with the Healthy Pregnancy Program (HPP), which was developed to educate and coordinate the care of pregnant women in a managed care setting.

STUDY DESIGN

Telephone survey.

PATIENTS AND METHODS

A random sample of program participants at 3 large health plans were contacted by telephone to evaluate their satisfaction with the program overall and with its components, including an educational booklet and telephone contact with a HPP nurse as needed. Women also were asked about changes in health behaviors (smoking, alcohol use, diet, and stress) resulting directly from participation in the HPP. Of 1155 eligible women participating in HPP who delivered a baby from April 1997 through March 1998, 684 completed the survey. The response rate was 59%.

RESULTS

Overall satisfaction with the HPP was reported by 96% of the women, and 76% reported the 2 highest ratings of satisfaction (completely or very satisfied). Reports of satisfaction were more likely for women who entered the program early in pregnancy, who read the booklet, and who had more telephone contacts. In general, at least half of the women in each behavior category reported improving their behavior, especially if they were younger, identified as high risk, or having their first child. Verbatim comments supported the high satisfaction levels.

CONCLUSIONS

The HPP is an example of a program that was developed to improve healthcare delivery in a managed care setting and, when evaluated, was found to result in highly satisfied mothers likely to improve their health behaviors.

[A study of hepatitis B virus(HBV) anti-genome and its inhibitory effect on HBV replication]

OBJECTIVE

To study the combination of triplex forming oligodeoxynucleotides (TFO) with hepatitis B virus gene and its effect on replication of HBV.

METHODS

An oligodeoxynucleotide (TFO20) which can form triplex with SP1 sites in HBV core promoter was synthesized and was linked with biotin. Both the liposome-TFO20 and naked TFO20 were transfected to HepG2.2.15 cells, which was detected by SABC assay and showed signals that TFO20 was combined with HBV DNA. ELISA, reverse transcript (RT)-PCR and fluorescence quantitative PCR were used to investigate the change of HBV DNA, 3.5 kb/3.4 kb RNA, 2.4 kb/2.1 kb RNA, HBsAg and HBeAg in HepG2.2.15 cells before and after treatment with TFO20.

RESULTS

The ratio of liposome-TFO20 and naked TFO20 transfected to HepG2.2.15 cells were 80% and 40%, respectively. TFO20 signals mainly distributed in the nucleus and cytoplasm. After treatment with TFO20, the level of HBV DNA was reduced from 10(7.01) to 10(4.94), while 3.5 kb/3.4 kb RNA, 2.4 kb/2.1 kb RNA, HBsAg and HBeAg were also reduced by 70.2%, 31.6%, 37.0%, 78.2% respectively.

CONCLUSIONS

TFO20 can be transfected into cells by packing with liposome and can be combined with HBV DNA. TFO20 can effectively inhibit replication of HBV.

[Histopathological observation of acute facial nerve impairment in rabbits]

OBJECTIVE

To investigate histopathological changes of acute facial nerve impairment.

METHODS

Ligation of facial nerve outside stylomastoid foramen with 3-0 silk, observation of histopathological changes of facial nerve on the 1st day, 3rd day and 5th day after ligation.

RESULTS

The facial nerve showed all kinds and various degrees of histopathological changes, from swelling to degeneration, in myeline and axon respectively.

CONCLUSION

All kinds and various degrees of pathological changes have been observed in myeline and axon after the ligation of facial nerve in rabbits. This study demonstrates that such injuries to the facial nerve become increasingly serious as the ligation lasts day after day.

Measuring continuity of elders' posthospital care

Continuity of care is a critical component of quality patient care, yet the paucity of reliable and valid measures of continuity of care make it difficult to ascertain the extent to which continuity has been achieved. The purpose of this article is to describe the development of an instrument to measure continuity of care that incorporates the perspectives of elders hospitalized for a chronic illness and their family caregivers. The instrument was used, and its reliability and validity examined, in a series of studies related to elders' posthospital transition. Elders in the studies ranged in age from 55 to 94 years. The findings supported content and construct validity, internal consistency reliability, and ability to detect changes in the same subjects at different points in time for the care management and services subscales. With further refinement, the continuity of provider and conflicting information subscales might also facilitate assessment of care continuity.

Signaling pathways underlying muscarinic receptor-induced [Ca2+]i oscillations in HEK293 cells

We have investigated the signaling pathways underlying muscarinic receptor-induced calcium oscillations in human embryonic kidney (HEK293) cells. Activation of muscarinic receptors with a maximal concentration of carbachol (100 microm) induced a biphasic rise in cytoplasmic calcium ([Ca2+]i) comprised of release of Ca2+ from intracellular stores and influx of Ca2+ from the extracellular space. A lower concentration of carbachol (5 microm) induced repetitive [Ca2+]i spikes or oscillations, the continuation of which was dependent on extracellular Ca2+. The entry of Ca2+ with 100 microm carbachol and with the sarcoplasmic-endoplasmic reticulum calcium ATPase inhibitor, thapsigargin, was completely blocked by 1 microm Gd3+, as well as 30-100 microm concentrations of the membrane-permeant inositol 1,4,5-trisphosphate receptor inhibitor, 2-aminoethyoxydiphenyl borane (2-APB). Sensitivity to these inhibitors is indicative of capacitative calcium entry. Arachidonic acid, a candidate signal for Ca2+ entry associated with [Ca2+]i oscillations in HEK293 cells, induced entry that was inhibited only by much higher concentrations of Gd3+ and was unaffected by 100 microm 2-APB. Like arachidonic acid-induced entry, the entry associated with [Ca2)]i oscillations was insensitive to inhibition by Gd3+ but was completely blocked by 100 microm 2-APB. These findings indicate that the signaling pathway responsible for the Ca2+) entry driving [Ca2+]i oscillations in HEK293 cells is more complex than originally thought, and may involve neither capacitative calcium entry nor a role for PLA2 and arachidonic acid.

Study of multi-drug resistant mechanisms in a taxol-resistant hepatocellular carcinoma QGY-TR 50 cell line

Cancer chemotherapy with taxol often fails due to acquired resistance of cancer cells, which is frequently associated with an overexpression of P-gp and alterations of beta-tubulin. A taxol-resistant cell line, QGY-TR50, derived from a human hepatocellular carcinoma (HCC) QGY-7703 cell line was used to investigate the mechanisms of taxol-resistance. QGY-TR50 cells showed more than 250-fold resistance to taxol and exhibited cross-resistance to other drugs including actinomycin D, doxorubicin, vinblastine, and vincristine. P-gp was highly expressed in QGY-TR50 cells. Expression levels of five human beta-tubulin isotypes (betaI-, betaII-,betaIII-, betaIva, and betaIvb-tubulin) were examined by real-time semi-quantitative PCR. Comparing with QGY-7703 cells, QGY-TR50 cells did not show any significant change in the expression levels of betaI-, betaIva, and betaIvb-tubulin. While a 1.2-fold increased in betaII-tubulin and a 0.5-fold decreased in betaIII-tubulin levels were observed. All results suggest that the P-glycoprotein could be one key factor involved in enhancing drug resistance in QGY-TR50 cells.

Hepatitis G viral RNA co-infection in plasma and peripheral blood mononuclear cells in patients with hepatitis C

The incidence of the co-infection of hepatitis G virus (HGV) and hepatitis C virus (HCV) and its clinical implication was investigated and the difference in the positive rate of HGV RNA and HCV RNA between plasma and peripheral blood mononuclear cells (PBMCs) observed. By using reverse transcriptase polymerase chain reaction (RT-PCR) assay, HCV-RNA and HGV-RNA in plasma and PBMCs of 72 patients with hepatitis C was detected. It was showed that HGV RNA was positive in plasma of 11 patients, in PBMCs of 15 patients, and simultaneously in both of plasma and PBMCs of 10 patients with the co-infection rate being 22.2%. Nine patients were both HGV RNA and HCV RNA positive in plasma, 11 patients were both HGV RNA and HCV RNA positive in PBMC, and 6 patients were both HGV RNA and HCV RNA positive in both plasma and PBMC with the positive rate being 12.4%, 15.3% and 8.3% respectively. The positive rate of both HGV RNA and HCV RNA in PBMCs was higher than in plasma. It was concluded that the HGV co-infection rate in the patients with hepatitis C was 22.2%. Simultaneous examination of plasma and PBMC can improve clinically detectable rate.

Molecular epidemiologic study of Mycoplasma genitalium infection in high risk populations of sexually transmitted diseases in China

OBJECTIVE

To detect Mycoplasma genitalium (Mg) infection in high risk populations of sexually transmitted diseases (STDs) from several cities in China and to clarify the possible role of Mg in the pathogenesis of non-gonococcal urethritis.

METHODS

Polymerase chain reaction (PCR) based on 2 pairs of primers, one for Mg-Pa (adhesion protein) and the other for 16S-rRNA (Mycoplasma genera) was used to detect Mg infection. Urogenital specimens of different high risk populations and urethritis patients, were collected from the Guangdong, Kunming, Shanghai, Nanjing, and Changzhou areas.

RESULTS

The positive detection rate of Mg-DNA in high risk populations of STDs was significantly higher than that of the control group (chi 2 = 7.82, P < 0.01). The positive detection rates in Guangdong STD clinics and promiscuous persons from Kunming were higher than those from the Shanghai, Nanjing, and Changzhou areas (chi 2 = 8.54, P < 0.01 and chi 2 = 5.89, P < 0.05). Mg DNA could be detected in those patients without other relevant pathogens. Some patients were simultaneously infected with Mg and other microbes, such as Chlamydia trachomatis and/or Ureaplasma urelyticum. The positive Mg-DNA detection rate in patients with urethritis symptoms was higher than in patients without the symptoms (chi 2 = 11.68, P < 0.01).

CONCLUSION

Mg infection exists in high risk populations of STDs in China, and the Mg infection rate is different among different high risk groups.

Effects of Bcl-2 and Bcl-XL protein levels on chemoresistance of hepatoblastoma HepG2 cell line

The ratio between apoptotic promoters and repressors in the Bcl-2 family determines the chemosensitivity of cells to apoptotic stimuli. This study examines the chemoresistance of a transfected human hepatoblastoma HepG2 cell-line during Taxol and Doxorubicin application. Sense bcl-2, and anti-sense bcl-XL gene fragments were separately inserted into HepG2 cells via stable transfection. The expression profile of the Bcl-2 family proteins was determined by Western blot analysis. Chemosensitivity of the transfected cells was measured by Trypan blue exclusion assay and XTT reduction assay during drug application. In the absence of Bax protein, HepG2 cells with elevated Bcl-2 protein levels did not exhibit any significant increase in chemosensitivity towards the drugs. Transfected cells with reduced Bcl-XL levels became more sensitive to the drugs, and a significant difference in IC50 values was observed. The chemosensitivity of HepG2 cells to Taxol and Doxorubicin was not affected by Bcl-2 levels, while reduction of Bcl-XL levels rendered the cells more sensitive to the drugs. This suggests that the Bcl-2 protein alone could not protect HepG2 cells from drug-induced apoptosis, and that the Bcl-XL protein may be a target for gene therapy in hepatoblastoma treatment.

Molecular mimicry of human tumor antigen by heavy chain CDR3 sequence of the anti-idiotypic antibody

We isolated and characterized an anti-idiotype monoclonal antibody (AR42.1) which is capable of mimicking a distinct and specific epitope of MUC-1 antigen. The cDNA sequences coding for the AR42.1 variable regions were determined. We found significant amino acid homology between complementary determining regions 3 (CDR3) in the heavy chain of AR42.1 and the determinant epitope sequence of MUC-1. This 10 amino acid sequence may represent an "internal image" of the anti-idiotype antibody to the MUC-1 antigen, and could be used for development of a MUC-1 surrogate for immunotherapy.

Stain removal efficacy of two new fluoride dentifrices containing essential oils

PURPOSE

To assess in vitro the stain removal efficacy of two new antiplaque/antigingivitis dentifrices utilizing a modification of a previously validated Stookey method.

MATERIALS AND METHODS

The modifications to the original Stookey method are the following: (1) study design; three 5 x 5 Latin Squares were employed to minimize bias stemming from position or test run in the study. (2) statistical success criteria; a test formulation was judged to be effective if the lower one-sided 95% confidence limit was "equal to or higher than" 50 since a minimum PCR (pellicle cleaning ratio) score of 50 is needed for a dentifrice to show clinical efficacy. The two test dentifrice formulations contained a fluoride source, a silica abrasive system, and four essential oils. The ADA reference abrasive material (calcium pyrophosphate) and placebo toothpaste were included as positive and negative controls, respectively.

RESULTS

Compared to the negative control, the positive control exhibited a statistically higher PCR score; therefore, the validity of this modified Stookey method was confirmed. Additionally, the lower limits of the one-sided 95% confidence interval for the two dentifrice formulations were above the threshold PCR of 50; therefore, this modified Stookey method should predict that both essential oil-containing dentifrices possess acceptable stain removal power.

Caries inhibition efficacy of an antiplaque/antigingivitis dentifrice

PURPOSE

To evaluate the efficacy of a fluoride dentifrice containing a fixed combination of essential oils (Thymol, Menthol, Eucalyptol, and Methyl Salicylate) in preventing caries in Sprague Dawley rats.

MATERIALS AND METHODS

The dentifrice contains 0.76% sodium monofluorophosphate (SMFP) as the fluoride source and a silica abrasive system. A fluoride-free placebo and a clinically proven USP dentifrice reference standard for SMFP/silica were included as controls. Three groups of 45 SDV-free Sprague Dawley weanlings were infected by a cariogenic strain of Streptococcus sobrinus and fed cariogenic diet NIH 2000 ad libitum. Animals were treated twice daily (once on weekends) with the assigned dentifrice using a cotton-tipped applicator, for 5 wks, after which they were terminated and caries scored using Larson's modification of the Keyes method.

RESULTS

Analyses of variance were used to compare inter-group means, the total E lesion score was the primary efficacy variable. Compared with the fluoride-free vehicle control, the experimental dentifrice and USP reference standard dentifrice produced a statistically significant reductions of 18.3% and 12.2% respectively for total caries score (P<0.001). Compared with the clinically tested USP positive control dentifrice, the experimental dentifrice produced a statistically significant reduction in the total caries score of 6.9% (P=0.028). The results of this study show that 1) both the new dentifrice containing essential oils and USP dentifrice are statistically significantly effective in reducing caries in the rat model, 2) the anticaries activity of the SMFP dentifrice is not adversely affected with the addition of essential oils.

Enhancement of transfection by physical concentration of DNA at the cell surface

Efficient DNA transfection is critical for biological research and new clinical therapies, but the mechanisms responsible for DNA uptake are unknown. Current nonviral transfection methods, empirically designed to maximize DNA complexation and/or membrane fusion, are amenable to enhancement by a variety of chemicals. These chemicals include particulates, lipids, and polymer complexes that optimize DNA complexation/condensation, membrane fusion, endosomal release, or nuclear targeting, which are the presumed barriers to gene delivery. Most chemical enhancements produce a moderate increase in gene delivery and a limited increase in gene expression. As a result, the efficiency of transfection and level of gene expression after nonviral DNA delivery remain low, suggesting the existence of additional unidentified barriers. Here, we tested the hypothesis that DNA transfection efficiency is limited by a simple physical barrier: low DNA concentration at the cell surface. We used dense silica nanoparticles to concentrate DNA-vector (i.e. DNA-transfection reagent) complexes at the surface of cell monolayers; manipulations that increased complex concentration at the cell surface enhanced transfection efficiency by up to 8.5-fold over the best commercially available transfection reagents. We predict that manipulations aimed at optimizing DNA complexation or membrane fusion have a fundamental physical limit; new methods designed to increase transfection efficiency must increase DNA concentration at the target cell surface without adding to the toxicity.

[Mutations of Q20L and G247D improved the specific-activity and optimum pH of glucose isomerase]

The mutants of Q20L and G247D of glucose isomerase (GI) were constructed by in vitro site-directed mutagenesis of GI gene with double-primersmethod. The recombinant plasmids pTKD-GIQ20L and pTKD-GIG247D were expressed in E. coli K38 strain. The comparison experiments of mutant enzymes with wild-type GI showed that: (1) the optimum temperature of GIQ20L was decreased by 5 degrees C. Its thermostability was only 78% half-time of the wild type. But its substrate affinity was enhanced. (2) The specific-activity of GIG247D was increased by 33%, and the optimum pH was lowered by 0.6 unit. However, the thermostability of GIG247D was decreased. We supposed, based on the above facts and 0.19 nm resolution crystal structure of SM33GI, that Gln20 locates between alpha 0-helix and alpha 1-helix, the substitution of hydrophobic side chain of Leu for hydrophilic side chain of Gln may enhance the hydrophobic interaction of the molecular surface, leading to the decrease of the stability and thermostability of GIQ20L. Gly247 which is the last amino acid of a beta-sheet from 242 to 247 residues locates in the active core of GI. After replacement, Asp247 which has strong negative electricity may change the electrostatic distribution and influence the charge transfer processes of the active core. So the specific-activity of GIG247D was increased. The introduced charge could alter the pKa of dissociable groups and make the optimum pH lower. In addition, the side chain of Asp247 seems to be very crowded in the surrounding space conformation and is easy to exclude with the other side chains, therefore influences the stability of beta-sheet. Furthermore, Asp247 is in the vicinity of the interface of subunits, so it could interfere with the stability of the interaction between subunits. Thus, the GIG247D decreased the thermostability of SM33GI. The higher enzyme activity and the lower optimum pH will be very useful for industrial production of GI.

Characterization and transcriptional profiles of two rice MADS-box genes

The plant MADS-box gene family plays a key role in plant development, especially in flower development. We designed degenerate primer according to the MADS-box conserved region and isolated two cDNA from rice, FDRMADS6 and FDRMADS7, which are homologous to AP1. RT-PCR expression analyses by using total RNA isolated from root, shoot and flower showed that the FDRMADS6 transcript was detectable only in flower while FDRMADS7 was expressed in all three tissues. In situ hybridization experiments indicated that at the early stage of rice flower development, the transcripts of FDRMADS6 and FDRMADS7 were detected in the spikelet apical meristem, which were same as AP1. At the late stage, when flower organ primordia started differentiating, the expression of FDRMADS6 appeared to be specifically localized in developing stamens and the pistil primordia, while the transcripts of FDRMADS7 were detectable abundantly throughout the organ primordia. Our results suggest the two MADS-box genes may be members of the AP1 family, but may have different functions.

[A study on the relationship between the expression of Bax gene products and prognosis in patients with human non-small cell lung cancer]

BACKGROUND

To explore the relationship between the expression of Bax gene and oncogenesis , development and prognosis of lung cancer.

METHODS

The expression level of Bax gene products was detected in 124 human non-small cell lung cancer by immunohistochemistry labelled-streptavidin-biotin methods.

RESULTS

The expressional level of Bax products in lung cancer tissues (53. 76 %) was significantly lower than that in the normal tissues adjacent to lung cancer (75. 51 %) and normal lung tissues (74. 97 %) ( P < 0. 01) . The expressional level of Bax products was closely related with P-TNM stage , the size of primary tumor and lymph node metastasis ( P < 0. 01 or P < 0. 05) ; but not to histological classification , cell differentiation and site of the cancer , and age , sex of the patients and smoking or not ( P > 0. 05) . The five-year survival rate in patients with high Bax expression was significantly higher than that in patients with low Bax expression ( P < 0. 01) .

CONCLUSIONS

Abnormal expression of Bax gene may play an important role in the oncogenesis , development and prognosis of lung cancer. Bax gene may be involved in the oncogenesis , development and metastasis of lung cancer.

[A multicenter randomized phase II trial of domestic product of rhG-CSF(Rui Xue Xin) in preventing leukopenia caused by chemotherapy in patients with lung cancer]

BACKGROUND

To evaluate the effect and toxicity of the domestic product of rhG-CSF (Rui Xue Xin) in preventing leukopenia caused by chemotherapy in patients with lung cancer.

METHODS

67 patients in multicenter were randomly devided into AB group and BA group. The first cycle was a trial cycle (chemotherapy plus injection of Rui Xue Xin) , and the second cycle was a control cycle (chemotherapy alone) in AB group. On the contrast , the first cycle was a control cycle , and the second cycle was a trial cycle in BA group. The changes of white blood cell (WBC) and absolute neutrophil counts (ANC) , and the side effect of Rui Xue Xin were observed and compared between the trial cycle and control cycle.

RESULTS

Of the 67 patients , 6 cases were out of the trial because of patient compliance , and the another one case due to fever , and the other 61 cases could be used to analyze and to evaluate the effects and toxicity of Rui Xue Xin. The duration of leukopenia and neutropenia in cycle A was significantly shorter than that in cycle B ( P < 0. 01) . The nadirs of WBC and ANC following chemotherapy were remarkably higher in cycle A than those in cycle B ( P < 0. 01) . The incidence of chemotherapy delay due to WBC < 4. 0 *109 /L on the 21st day after chemotherapy in cycle A was also significantly lower than that in cycle B ( P < 0. 01) . The total rate of side effects of Rui Xue Xin was 26. 2 % , including pain and scleroma on the injection sites , weakness , fever. But , all of them were mild and didn't need to give any treatment.

CONCLUSIONS

The results demonstrate that Rui Xue Xin is able to reduce the degree of leukopenia and neutropenia , and to shorten the duration of leukopenia and neutropenia caused by chemotherapy in patients with lung cancer. The toxicity is also slight.

Anti-hepatoma activity of taxol in vitro

AIM

To investigate the in vitro anti-hepatoma activity of taxol against SMMC-7721 human hepatoma cells.

METHODS

The hepatoma cell growth was measured by MTT-microculture tetrazolium assay. Cell-cycle kinetics and apoptosis were analyzed by flow cytometry and microscopic examination.

RESULTS

Taxol inhibited the hepatoma cell growth in concentration- and time-dependent manners with IC50 of 18.96 nmol.L-1. Marked cell accumulation in G2/M phase and multinucleated cells were also observed after treatment with taxol 10 nmol.L-1. In addition, taxol at 10 nmol.L-1 could induce the apoptosis of hepatoma cells.

CONCLUSION

Taxol suppresses the growth of SMMC-7721 human hepatoma cells in vitro by causing cell-cycle arrest, aberrant mitosis, and apoptosis of the human hepatoma cells.

Expression of Bcl-2 family proteins during chemotherapeutic agents-induced apoptosis in the hepatoblastoma HepG2 cell line

This study demonstrates that two anticancer drugs, taxol and doxorubicin (Dox), can kill human hepatoblastoma HepG2 cells in a dose-dependent manner via the induction of apoptosis. Characteristic events, including externalization of phosphatidylserine, cytoplasmic shrinkage, chromatin condensation and DNA degradation, were observed in a large majority of the drug-treated cells. DNA fragmentation showed that a ladder of DNA fragments of approximately 200 bp multiples was observed in taxol-treated, but not in Dox-treated, cells. In addition, the expression patterns of Bcl-2 family members during taxol or Dox treatment were investigated. Results from Western blot analysis indicated that HepG2 cells did not express either the death repressor Bcl-2, or the death promoters Bcl-XS and Bax. However, during the apoptotic process one death repressor, Bcl-XL, and two death promoters, Bak and Bad, were expressed. The expression levels of Bcl-XL and Bak remained unchanged, whereas the level of Bad was down-regulated. As the ratio between death repressors and death promoters in the Bcl-2 family will determine the sensitivity of cells to apoptotic stimuli, the findings suggest that the changed expression patterns of Bcl-2 family proteins caused by anticancer drugs in liver cancer cells may be involved in chemoresistance.

Effects of three different Ca(2+) pump ATPase inhibitors on evoked contractions in rabbit aorta and activities of Ca(2+) pump ATPases in porcine aorta

Using vascular smooth muscle, we describe the actions of three pharmacological tools, cyclopiazonic acid (CPA), thapsigargin (TG) and 2,5-di-(tert-butyl)-1,4-benzohydroquinone (tBHQ), which are presumed to act as selective inhibitors of the sarco-endoplasmic reticulum Ca(2+)-ATPases (SERCAs). In porcine aortic smooth muscle microsomes two Ca(2+)-ATPase activities have been described, one vanadate-sensitive and one vanadate-resistant, representing the Ca(2+)-ATPase activities of the plasma membrane and SERCAs, respectively. In agreement, CPA, TG and tBHQ, in the concentration range 0.1 microM to 0.1 mM, dose-dependently inhibit the Ca(2+)-ATPase activity only in the vanadate-resistant microsomes. However, 0.1 mM tBHQ also significantly inhibited the Ca(2+)-ATPase activity of vanadate-sensitive microsomes. In rabbit aortic rings, all three SERCA inhibitors produced a dose-dependant inhibition of contractions evoked by 20 mM caffeine or 1 microM phenylephrine (PE) in a Ca(2+)-free physiological solution. However, in PE-contracted rings, tBHQ (> or =30 microM) also significantly inhibited the ability of cromakalim to induce relaxation. In conclusion, the data suggest that CPA, TG and tBHQ can all act as selective SERCA inhibitors in both porcine and rabbit aortic smooth muscle. However, in contrast to CPA and TG, high concentrations of tBHQ can exhibit some nonspecific effects, which include inhibition of the plasma membrane Ca(2+)-ATPase and possibly K(+) channels regulated by cromakalim.

In vitro expression of hepatitis C virus non-structure 5 antigen in the HepG2 cell line

To establish a cell line as a model system for HCV infection and propagation in vitro, a human HepG2 cell line was incubated with a HCV RNA positive serum. The sABC immunological techniques and gold-labeled colloid electron microscopy method were employed to examine the viral proteins in those cells. The HCV non-structure 5 antigen was first detected in the HepG2 cells 72 h after incubation. The antigen was continuously observed in the cytoplasm as well on the membrane of the HepG2 cells even after 1, 2, 3 and 4 weeks after incubation. The observation of HCV non-structure 5 antigen continuously expressed in the HepG2 cells strongly indicates that the cells may have been infected by HCV virus. Therefore, the HepG2 cell line may serve as a potential host for establishment of HCV infection and propagation in vitro.

Study on biologic activity for membrane of normal bone marrow cells with infection of epidemic hemorrhagic fever virus

Using DPH fluorescence probe, the membrane of normal bone marrow cells with infection of epidemic hemorrhagic fever virus (EHFV) was labeled. The membrane lipid fluidity was obviously decreased from the membrane lipid fluorescence polarization. The membrane lipid fluidity of lymphocyte, monocyte and neutrophilic granulocyte was dynamically observed. After culturing the cells for 1, 6, 24 and 72 h, it was found that all the membrane lipid fluidity of the infected cells was decreased obviously with the longer the culturing time, the more obvious it. Compared with the normal control groups, there was a significant difference statistically (P < 0.05-0.01). It was suggested that the decrease of the membrane lipid fludity of normal bone marrow cell with infection of EHFV had correlation with the degree of virus invading and cell-function injury.

Synthetic DNA delivery systems

The ability to safely and efficiently transfer foreign DNA into cells is a fundamental goal in biotechnology. Toward this end, rapid advances have recently been made in our understanding of mechanisms for DNA stability and transport within cells. Current synthetic DNA delivery systems are versatile and safe, but substantially less efficient than viruses. Indeed, most current systems address only one of the obstacles to DNA delivery by enhancing DNA uptake. In fact, the effectiveness of gene expression is also dependent on several additional factors, including the release of intracellular DNA, stability of DNA in the cytoplasm, unpackaging of the DNA-vector complex, and the targeting of DNA to the nucleus. Delivery systems of the future must fully accommodate all these processes to effectively shepherd DNA across the plasma membrane, through the hostile intracellular environment, and into the nucleus.

[Comparison between carboplatin and cisplatin plus etoposide and carboplatin plus etoposide in the treatment of small cell lung cancer.]

BACKGROUND

To evaluate the effect and toxicity of combination chemotherapy with carboplatin and cisplatin plus etoposide (CPE regimen) and carboplatin plus etoposide (CE regimen) in the treatment of small cell lung cancer (SCLC) .

METHODS

Thirty-two patients with SCLC were treated with CPE and CE regimens , and each regimen had 16 cases respectively. There were 10 retreated cases in CPE group and 7 retreated cases in CE group.

RESULTS

The total response rate (CR + PR) was 81. 3 %(13/ 16) in CPE group , and 87. 5 %(14/ 16) in CE group ( P > 0. 05) respectively. The response rate of the retreated cases in CPE group was 60 %(6/ 10) , and 42. 9 %(3/ 7) in CE group ( P < 0. 05) . The bone marrow suppression rate was 71. 9 % in CPE group and 93. 8 % in CE group ( P < 0. 05) . There were no significant differences between other toxicity in both groups ( P > 0. 05) .

CONCLUSIONS

The therapeutic effect of CPE regimen in SCLC is similar to that of CE regimen , but the bone marrow suppression rate of CPE regimen is less severe than that of CE regimen. The therapeutic effect of CPE regimen is better than that of CE regimen for the retreated cases.

Transcriptional induction of stromelysin-3 in mesodermal cells is mediated by an upstream CCAAT/enhancer-binding protein element associated with a DNase I-hypersensitive site

Stromelysin-3 (ST3) is a matrix metalloproteinase whose synthesis is markedly increased in stromal fibroblasts of most invasive human carcinomas. In the present study, we have investigated the molecular mechanisms by which high levels of ST3 expression can be induced. In contrast to the early and transient induction of interstitial collagenase by 12-O-tetradecanoylphorbol-13-acetate (TPA), the fibroblastic induction of ST3 was found to be delayed and to require protein neosynthesis. We demonstrated that this induction is transcriptional and does not result from changes in RNA stability. By looking next to promoter regions accessible to DNase I upon gene induction, we have identified two distal elements and have characterized their role in the transcriptional regulation of ST3. The first one is a TPA-responsive element that controls the base-line ST3 promoter activity but is not required for its activation. We demonstrate that ST3 gene induction is actually mediated by the second element, a C/EBP-binding site, by showing: (i) that this element becomes accessible in cells induced to express ST3, (ii) that endogenous C/EBPbeta binds to the ST3 promoter, and (iii) that this binding leads to ST3 transcriptional activation. Our study provides new insights into the regulation of ST3 and suggests an additional role for C/EBP transcription factors in tissue remodeling processes associated with this MMP.

Genetic control of trichome branch number in Arabidopsis: the roles of the FURCA loci

We are using trichome (hair) morphogenesis as a model to study how plant cell shape is controlled. During a screen for new mutations that affect trichome branch initiation in Arabidopsis, we identified seven new mutants that show a reduction in trichome branch number from three branches to two. These mutations were named furca, after the Latin word for two-pronged fork. These seven recessive mutations were placed into four complementation groups that define four new genes: FURCA1, FURCA2, FURCA3 and FURCA4. The trichome branch number phenotype indicates that the FURCA genes encode positive regulators of trichome branch initiation. Analysis of double mutants suggests that primary and secondary branch initiation events are not genetically distinct, but rely on the levels of partially redundant groups of regulators of trichome branch initiation. Based on the analysis of both epistatic and additive genetic interactions between the FURCA genes and other genes that control trichome branch number, we propose a model that explains how these genes interact to control trichome branch initiation. This model successfully predicts the phenotypes of all the single and double mutants examined and suggests points of control of the trichome branch pathway.

Control of organ asymmetry in flowers of Antirrhinum

Organ asymmetry is thought to have evolved many times independently in plants. In Antirrhinum, asymmetry of the flower and its component organs requires cyc and dich gene activity. We show that, like cyc, the dich gene encodes a product belonging to the TCP family of DNA-binding proteins that is first expressed in the dorsal domain of early floral meristems. However, whereas cyc continues to be expressed throughout dorsal regions, expression of dich eventually becomes restricted to the most dorsal half of each dorsal petal. This correlates with the effects of dich mutations and ectopic cyc expression on petal shape, providing an indication that plant organ asymmetry can reflect subdomains of gene activity. Taken together, the results indicate that plant organ asymmetry can arise through a series of steps during which early asymmetry in the developing meristem is progressively built upon.

Muscarinic receptor-mediated calcium signaling in spiral ganglion neurons of the mammalian cochlea

Using indo-1 microspectrofluorometry, we examined the effects of cholinergic agonists on the concentration of intracellular Ca(2+) ions ([Ca(2+)](i)) in spiral ganglion neurons, isolated from rat cochleae at different stages of post-natal development (from P3 to P30). Extracellular application of acetylcholine (ACh) or carbamylcholine generated a rapid and transient increase in [Ca(2+)](i). The ACh concentration-response curve indicated an apparent dissociation constant (K(d)) of 8 microM and a Hill coefficient of 1.0. Removing extracellular free Ca(2+) did not suppress the ACh-induced Ca(2+) responses suggesting an intracellular Ca(2+)-release mechanism. When we compared the cholinergic response at different stages of postnatal development, there were no significant differences on the aspect of the Ca(2+) response and the percentage of responsive neurons, which ranged between 50 and 65% per cochlear preparation. The application of muscarine triggered reversible Ca(2+) responses similar to those observed with ACh, with an apparent K(d) of 10 microM and a Hill coefficient of 1.0. The cholinergic-induced Ca(2+)pirenzepine. Nicotine (10 to 100 microM) did not evoke Ca(2+) responses and the nicotinic antagonist curare (10 microM) did not block the ACh-evoked responses. The present study is the first direct demonstration of functional muscarinic receptors (mAChRs) in spiral ganglion neurons. These mAChRs activated by the cholinergic lateral efferent system may participate in the regulation of the electrical activity of the afferent auditory fibers contacting the inner hair cells.

Chemosensitivity of human hepatocellular carcinoma cell line QGY-7703 is related to bcl-2 protein levels

Bcl-2 protein is one of the major apoptosis regulators. The study examines the effect of Bcl-2 protein on the chemosensitivity of a human hepatocellular carcinoma cell line, QGY-7703. Western blot analysis showed that Bcl-2 and Bax proteins were expressed in QGY-7703 cells. Characteristic features of Taxol- and doxorubicin-induced apoptosis were evidenced by the Annexin-V binding assay, TUNEL and DAPI staining. At constant Bax protein levels, stable sense and antisense gene-transfected QGY-7703 cells showed that constitutive expression of Bcl-2 could render the cells more resistant to Taxol and doxorubicin. Contrarily, decreased Bcl-2 levels caused the cells to be more sensitive to the drugs. As Bcl-2 levels are directly proportional to the resistance of QGY-7703 cells to Taxol and doxorubicin, manipulation of Bcl-2 could be performed to enhance the sensitivity of liver cancer to chemotherapeutic agents.

[Correlation of conformational change with enzyme activity of glucose isomerase in denaturants monitored with high performance liquid chromatography]

Glucose isomerase (GI) can catalyze in vitro the isomerization of D-glucose to D-fructose. So it is an extremely important industrial enzyme in the commercial conversion of starch to high fructose syrups. In the previous papers, we have purified and characterized the enzyme from streptomyces diastaticus M1033 of China and obtained the crystal structures by X-ray. In this paper, a method for measurement of the dynamic conformational change procedure of glucose isomerase in various concentrations of denaturants by HPLC has been established. At first the relative molecular mass of GI in solution is measured by HPLC on PROTEIN PAK 300SW (7.5 mm i.d. x 30 cm) column. The relative molecular mass of GI is about 150,000. So GI exists as tetramer in the solution without denaturants. In 0-5 mol/L guanidine hydrochloride, incubated at 30 degrees C for 30 min, GI is gradually dissociated into monomer, and at the same time its activity gradually disappears. In various concentrations of urea and incubation at 30 degrees C for 30 min (or 60 degrees C for 1 h), the results are different from that in guanidine, because the monomers peaks of GI is not found. Only in certain concentrations of urea, the small dimer peaks of GI is found, but the activity of GI significantly disappears. Moreover as the increase of the urea concentration, the retention time of tetramer peak is gradually decreases. From the fluorescence spectra, we found the conformation of GI changed in the solution of urea. So perhaps in urea, the conformation of GI become a little unfolded, and the active region is partly damaged, which makes GI partly inactive. Dissociation into inactive monomers and conformation partly unfolding are all the reason of GI inactivation in denaturants.

Clinical outcomes in statin treatment trials: a meta-analysis

OBJECTIVE

To determine the risk of cardiovascular events and death in patients receiving statin treatment for cholesterol regulation.

METHODS

Systematic review and meta-analysis of all randomized controlled trials that were published as of April 15, 1997. Primary or secondary prevention trials or regression trials were eligible.

MAIN OUTCOME MEASURES

All-cause mortality, fatal myocardial infarction (MI) or stroke, nonfatal MI or stroke, angina, and withdrawal from the studies. Both random- and fixed-effects models were run for the outcomes of interests, and results are expressed as odds ratios (ORs). Sensitivity analyses tested the impact of the study type and duration, statin treatment type, and control arm event rates. Intent-to-treat denominators were used whenever they were available, and the number needed to treat was calculated when appropriate.

RESULTS

Seventeen studies (21 303 patients) were included (2 secondary prevention studies, 5 mixed primary-secondary prevention population studies, and 10 regression trials). Treatment groups included lovastatin (t = 5), pravastatin (t = 10), and simvastatin (t = 3). For all-cause mortality, the OR was 0.76 (95% confidence interval [CI], 0.67-0.86) in favor of receiving statin treatment; for fatal MI, the OR was 0.61 (95% CI, 0.48-0.78); for nonfatal MI, the OR was 0.69 (0.54-0.88); for fatal stroke, the OR was 0.77 (95% CI, 0.57-1.04); for nonfatal stroke, the OR was 0.69 (95% CI, 0.54-0.88); and for angina, the OR was 0.70 (95% CI, 0.65-0.76).

CONCLUSIONS

Patients who received statin treatment demonstrated a 20% to 30% reduction in death and major cardiovascular events compared with patients who received placebo. This advantage was generally present across study types and statin treatment types and for patients with less severe dyslipidemias. The benefit in clinical outcomes was noticeable as early as 1 year.

Controlled DNA delivery systems

PURPOSE

Genes are of increasing interest as pharmaceuticals, but current methods for long-term gene delivery are inadequate. Controlled release systems using biocompatible and/or biodegradable polymers offer many advantages over conventional gene delivery approaches. We have characterized systems for controlled delivery of DNA from implantable polymer matrices (EVAc: poly (ethylene-co-vinyl acetate)) and injectable microspheres (PLGA and PLA: poly (D, L-lactide-co-glycolide) copolymer and poly (L-lactide), respectively).

METHODS

Herring sperm DNA and bacteria phage lambda DNA were encapsulated as a model system. Released DNA concentration was determined by fluoroassays. Agarose electrophoresis was used to determine the dependence of release rate on DNA size. The Green Fluorescent Protein (GFP) gene was used to determine the integrity and functionality of released DNA.

RESULTS

Both small and large DNA molecules (herring sperm DNA, 0.1-0.6 kb; GFP, 1.9 kb; lambda DNA, 48.5 kb) were successfully encapsulated and released from EVAc matrices, and PLGA or PLA microspheres. The release from DNA-EVAc systems was diffusion-controlled. When co-encapsulated in the same matrix, the larger lambda DNA was released more slowly than herring sperm; the rate of release scaled with the DNA diffusion coefficient in water. The chemical and biological integrity of released DNA was not changed.

CONCLUSIONS

These low cost, and adjustable, controlled DNA delivery systems, using FDA-approved biocompatible/biodegradable and implantable/injectable materials, could be useful for in vivo gene delivery, such as DNA vaccination and gene therapy.

Involvement of LFA-1 in hepatic NK cell (pit cell)-mediated cytolysis and apoptosis of colon carcinoma cells

BACKGROUND/AIMS

Previous studies have shown that hepatic natural killer (NK) cells, also called pit cells, have a higher cytotoxicity against certain tumor cells and have a higher expression of the cell adhesion molecule CD11a as compared with blood NK cells. We further investigated the involvement of the adhesion molecules, reported to be involved in target cell killing by blood NK cells, in pit cell-mediated colon carcinoma cell killing.

METHODS

51Cr-release and DNA fragmentation were used to quantify target cell lysis and apoptosis, respectively. Adhesion of pit cells to CC531s monolayers was quantitated.

RESULTS

Flow cytometric analysis showed that pit cells expressed CD2, CD11a, CD18 and CD54. CC531s cells expressed only CD54. Treatment of freshly isolated pit cells with monoclonal antibodies (mAbs) to CD11a and CD18 inhibited not only the pit cell-mediated CC531s cytolysis but also the pit cell-induced apoptosis of CC531s cells. The combination of mAbs to CD11a, CD18 and CD54 further increased the inhibition of pit cell-mediated CC531s cytolysis and apoptosis. Anti-CD2 mAb did not affect these processes. The binding of pit cells to CC531s cells was also inhibited by anti-CD11a, and CD18 mAbs, but not by anti-CD2 mAb. Anti-CD54 mAb reduced the target cell killing and the binding only slightly.

CONCLUSIONS

These results indicate that CD11a/CD18 (LFA-1) present on pit cells plays an important role in pit cell-mediated target cell adhesion, lysis and apoptosis. This finding might explain why pit cells, which have a higher expression of LFA-1 as compared to blood NK cells, are more cytotoxic against tumor cells as compared to blood NK cells.

L-selectin expression enhances clonogenesis of CD34+ cord blood progenitors

L-selectin, a surface adhesion glycoprotein expressed on leukocytes, has a well-established role in mediating inflammation and lymphocyte recirculation. Recent evidence suggests that L-selectin may also influence hematopoiesis. We observed that a greater proportion of CD34+ cells express L-selectin in cord blood compared with adult bone marrow, and we hypothesized that L-selectin expression is associated with enhanced clonogenic properties. To test this, we compared CD34+/L-selectin+ cells with CD34+/L-selectin- cells in hematopoietic clonogenic assays. From CD34+/L-selectin+ cell cultures, we observed a 3-fold increase of d 12-14 colony-forming unit-granulocyte/macrophage and multipotent progenitor cells, and a 5-fold enhancement of primitive d 21 high proliferative potential colony-forming cells compared with the progeny of CD34+/L-selectin- cells. We conclude that CD34+ cord blood cells expressing L-selectin are enriched in their clonogenic activity compared with cell fractions lacking L-selectin expression.

Isolation and identification of Mycoplasma genitalium from high risk populations of sexually transmitted diseases in China

OBJECTIVE

To investigate Mycoplasma genitalium (Mg) infection in high risk populations of sexually transmitted diseases (STDs) in China by means of culture, Mg-DNA detection, observation under an electron microscope (EM) and an atomic force microscope (AFM).

METHODS

227 urogenital specimens taken from both patients in clinics and high risk populations of STDs in Beijing, Nanjing and Shanghai areas were cultured in SP-4 medium for isolation of Mg. Suspicious positive strains were identified first by PCR technique which could amplify the special DNA fragments of Mg adhesion protein (Mg-Pa) and 16S-rRNA sequences. The morphologic features of Mg were observed under EM and AFM.

RESULTS

Eight strains were isolated from the 227 specimens, the total positive rate was 3.52%. The isolated strains met the criteria of growth and metabolic conditions required by Mg. Specific fragments of Mg-DNA (374 bp based on Mg-Pa and 402 bp on 16S-rRNA primers, respectively) could be amplified from both the isolates and the genital secretions. Under EM and AFM, Mg showed different shapes, including flask, pear, spindle and globe shape. The typical shape of Mg was flask or pear shape with projecting neck portion and broadened terminal structure under EM and with constrictive ring between the neck and body under AFM.

CONCLUSION

Mg infection exists in high risk populations of STDs in China. We highly suggest the use of AFM in dermatological study.

[The expression of p16, CDK4 and pRb in hepatocellular carcinomas]

OBJECTIVE

To make an analysis of the expression of p16 gene, CDK4 and retinoblastoma protein(pRb) in human hepatocellular carcinoma(HCC).

METHODS

Application of immunohistochemistry to 40 cases of HCC and their adjacent liver tissues.

RESULTS

The abnormal expressions of p16, CDK4 and pRb were 94.44%(34/36), 40.00%(16/40) and 45.71%(16/35) respectively. Rb protein was strongly stained in 13/34(38.23%) cases lacking or weak staining with p16, which showed a negative relation between the expressions of Rb and p16. The abnormal expressions of both p16 and Rb were 15/34(44.11%) cases, indicating that except p16, there are some other ways to regulate Rb. In 14 cases of CDK4 overexpression, most of them (92.85%) presented p16 aberration, 50.00% of them were observed with pRb abnormal expression, 46.15% of them were along with the alterations of both p16 and pRb. There was no significant correlation between p16 or CDK4 or pRb abnormal expression and HCC malignant grade.

CONCLUSION

The data show that the aberrant expression of p16, CDK4 and pRb may play a role in the carcinogenesis of HCC. The changes of p16 expression is prominent.

[A clinical study on PA-MSHA vaccine in adjuvant therapy of lung cancer.]

BACKGROUND

To evaluate the effectiveness and safety of pseudomonas aeruginosa MSHA vaccine (PA-MSHA vaccine) used as immune modulator.

METHODS

The study was carried out by non-blinded randomized control trial. The lung cancer patients were divided into experimental group (44 cases) and control group (45 cases) . Both groups were given same chemotherapy , and the experimental group was injected PA-MSHA vaccine subdermally. After finishing the treatment , tumor response and infection rate were evaluated. Immune function was measured before , during and after the treatment respectively.

RESULTS

Clinical effective rate (CR + PR) was 59. 09 % in the experimental group , and 42. 23 % in the control group ( P < 0. 01) . Infection rate was 15. 91 % in the experimental group and 40 % in the control group ( P < 0. 05) . After the treatment , C3 and C4 , the ratio of CD4 to CD8 , NKcell activity and IL-2 level in the experimental group were significantly higher than those in the control group ( P < 0. 05) . Three cases in the experimental group had adverse reactions. One case had fever and was treated with antibiotics , while the other two with swelling in the injection site recovered automatically.

CONCLUSIONS

As a new kind of immune modulator , PA-MSHA vaccine can enhance immune function of lung cancer patient and prevent infection. It may improve chemotherapeutic effectiveness in adjuvant therapy of lung cancer with low adverse reaction rate.

Smoking hygiene: a study of attitudes to passive smoking

AIM

To study the attitudes and knowledge of adults in the Wellington area about the effects of passive smoking and measures to reduce exposure to smoke.

METHODS

A sample of 200 people, randomly selected in the Wellington area, answered a telephone survey on passive smoking.

RESULTS

Of the 200 respondents, 160 (80%) were males, 40 (20%) were females and approximately one-third (30%) were smokers. Most people (85.5%) thought public and private areas should be smoke-free when there were children around, but only half (53.5%) thought that smoking should be banned in cars when there are passengers. Most people (92.5%) correctly defined passive smoking. Half were aware that passive smoking negatively contributed to all the following diseases (asthma, cancer, heart disease, respiratory problems) and cot death but a higher percentage identified cancer (75.5%) and cot deaths (68.5%) specifically. Most smokers reported that they smoke at home or in their cars rather than in public places. Half the smokers (50.9%) did not smoke in front of children; a further 17.3% reported that they smoked less.

CONCLUSIONS

In this sample there was a relatively low level of awareness of the effects of passive smoking on health and a high prevalence of smoking in the presence of children. Smokers and non-smokers were almost equally divided on whether there should be a law restricting smoking in private cars, although the majority agreed that cars carrying children should be smoke-free. Public health efforts to reduce the harm from passive smoking should be focused on discouraging smoking, in settings in which children are exposed, including private cars when children are passengers.

Pit cells (Hepatic natural killer cells) of the rat induce apoptosis in colon carcinoma cells by the perforin/granzyme pathway

The high mortality of colon cancer is to a large extent caused by the frequent occurrence of liver metastasis. This is remarkable, because the liver harbors two distinct cell populations that can eliminate invading cancer cells, namely hepatic natural killer (NK) cells and Kupffer cells. These hepatic NK cells, known as pit cells, are the most cytotoxic cells of the naturally occurring NK cells. However, the mechanism by which pit cells eliminate tumor cells is largely unknown. Because we recently found an indication that apoptosis is involved, we tried to assess the role of this mode of cell death using an in vitro system with isolated pure pit cells (>90%) and CC531s cells, a rat colon carcinoma (CC) cell line. Pit cells induced apoptosis in CC531s cells as shown by quantitative DNA fragmentation, agarose gel electrophoresis, and different modes of microscopy. When extracellular Ca2+ was chelated by ethylene glycol-bis(beta-aminoethyl ether)-N,N,-tetraacetic acid (EGTA) during coincubation or when the pit cells were preincubated with the granzyme inhibitor 3,4-dichloroisocoumarin (DCI), the induction of apoptosis was abolished. These results show that pit cells use the Ca2+-dependent perforin/granzyme pathway to induce apoptosis in the CC531s cells, and not the alternative Ca2+-independent Fas pathway. To further exclude the possibility of the involvement of the Fas pathway, we treated CC531s cells with recombinant Fas ligand. This treatment did not result in the induction of apoptosis, indicating that CC531s cells are resistant to Fas-mediated apoptosis. We conclude therefore that pit cells induce apoptosis in CC cells in vitro by the perforin/granzyme pathway.

[Prevention and treatment of eyelid retraction and ectropion following lower eyelid blepharoplasty with tarsal tuck procedure]

OBJECTIVE

To prevent or decrease eyelid retraction and ectropion following lower eyelid blepharoplasty.

METHODS

The tarsal tuck procedure was performed during lower eyelid blepharoplasty to tighten the lower eyelid. This method had been used since 1991.

RESULTS

After the operation, the lower eyelid was tensional and steady. The complications of eyelid retraction and ectropion were diminished.

CONCLUSION

The pathologic basis of the eyelid bag is that the supporting tissues become lax so that the lower eyelid and lateral canthus move downwards. The exact aim of the tarsal tuck procedure is to correct these pathologic changes.

Safety of nifedipine in angina pectoris: a meta-analysis

-Our objective was to compare cardiovascular event rates in patients with stable angina receiving nifedipine as monotherapy or combination therapy and in active drug controls. A MEDLARS search of published articles from 1966 to 1995 in English, French, German, Italian, or Spanish, supplemented by a manual search of bibliographies, identified 60 randomized controlled trials that met protocol criteria. Blinded articles were extracted by 2 physicians. The pooled risks of death, withdrawal, and cardiovascular event were computed and expressed as odds ratios (ORs) for all nifedipine formulations and relative to same study control drug regimens. Thirty cardiovascular events were reported in 2635 nifedipine exposures (1.14%) and 19 events in 2655 other active drug exposures (0.72%). Unadjusted ORs for nifedipine versus controls were 1.40 (95% CI, 0.56 to 3.49) for major events (death, nonfatal myocardial infarction, stroke, revascularization procedure), 1.75 (95% CI, 0.83 to 3.67) for increased angina, and 1.61 (95% CI, 0.91 to 2.87) for all events (major events plus increased angina). Episodes of increased angina were more frequent on immediate-release nifedipine (OR, 4.19 [95% CI, 1.41 to 12.49]) and on nifedipine monotherapy (OR, 2.61 [95% CI, 1.30 to 5.26]). The OR for immediate-release nifedipine was significantly higher than that for sustained-release/extended-release nifedipine (P=0.001), and the OR for nifedipine monotherapy was higher than that for nifedipine combination therapy (P=0.03). Increased risks of cardiovascular events in patients with stable angina on nifedipine were due primarily to more episodes of increased angina, confined to the immediate-release formulation and to nifedipine monotherapy.

In vitro and in vivo secondary structure probing of the thrS leader in Bacillus subtilis

The Bacillus subtilis thrS gene is a member of the T-box gene family in Gram-positive organisms whose expression is regulated by a tRNA-mediated transcriptional antitermination mechanism involving a direct tRNA:mRNA interaction. The complex leader sequences of these genes share only short stretches of primary sequence homology, but a common secondary structure has been proposed by comparing the leaders of many genes of this family. The proposed mechanism forthe tRNA:mRNA interaction depends heavily on the secondary structure model, but is so far only supported by genetic evidence. We have studied the structure of the B.subtilis thrS leader in solution, in protection experiments using both chemical and enzymatic probes. The thrS leader structure was also probed in vivo using dimethylsulphate and the in vitro and in vivo data are in good accordance. We have organized the thrS leader into three major domains comprising six separate stem-loops. All but one of the short sequences conserved in this gene family are present in loop structures. The ACC specifier codon proposed to interact with the tRNAThrGGUisoacceptor is present in a bulge and probably exists in a stacking conformation. The proposed antiterminator structure is not visible in transcripts containing the terminator, but was probed using a transcript with the 3'-half of the terminator deleted and its folding appears consistent with the regulatory model. The leader sequences, and in particular the specifier domains, of the other genes of this family can be folded similarly to the experimentally solved thrS structure.