Molecular and immunohistochemical study of the inactivation of the p16 gene in primary hepatocellular carcinoma

OBJECTIVE

To determine whether p16 gene is involved in the genesis of primary hepatocellular carcinoma (HCC).

METHODS

Twenty-five HCC tumor samples with corresponding non-tumor liver tissue specimens were examined for p16 gene alterations. The identification of deletion of exon 1 and exon 2 in p16 gene was performed using comparative multiplex polymerase chain reaction (PCR) analysis. The point mutation of exon 2 in p16 gene was investigated by single strand conformational polymorphism (SSCP) analysis, and the status of p16 gene methylation was screened using a PCR based methylation analysis. 35 parafin-embedded specimens of HCC with corresponding non-tumor liver tissues, including the 25 cases described above for screening p16 gene alterations, were investigated for p16 protein expression using immunohistochemical analysis.

RESULTS

Among 25 cases, 2 homozygous deletions and 1 hemizygous deletion were found in HCC samples. No point mutation was identified in the remaining 22 tumor samples without p16 gene deletions. Hypermethylation was detected in 24% (6/25) of tumor samples. However, the corresponding non-tumor liver tissue specimens were always unmethylated at the p16 locus. Loss of p16 protein expression occurred in 16 of 35 (45.7%) tumor samples, and all the non-tumor liver tissue specimens showed positive p16 staining. For the 25 cases examined for p16 gene alterations, the loss of p16 protein expression was observed in all tumors with p16 gene alterations and also in 3 tumors without p16 gene alterations.

CONCLUSION

Inactivation of the p16 gene may play an important role in the genesis of primary hepatocellular carcinoma.

[Studies on thymidine kinase gene (TK) and GCV system for treatment of human retinoblastoma (RB)]

The antitumor effect of herpes simplex virus thymidine kinase (HSV-TK)/GCV system on human retinoblastoma (RB) was studied here. A retroviral vector with tk gene (pLXSN-TK) was transduced into packaging cell line PA317. Recombinant retroviral was obtained and employed to infect human RB cells. The in vitro efficacy of TK/GCV was evaluated by survival rate of RB cells with and without TK transduced 5 days after treated with GCV. A nude mouse model with heteroplantation of human RB was established to examine the in vivo efficacy. Mice with RB were given an in situ injection of retrovirus followed by treatment with GCV for 14 days (50 mg/kg). The RB/TK cells in tissue culture dish showed far more sensitive to GCV than RB cells. The tumors in RB mice with TK gene transduced were much smaller than those in control. The results indicate that HSV-TK/GCV system can suppress growth of RB both in vitro and in vivo. It could be a valuable method for treatment of RB patients.

[A study on the inactivation of p16 genes and the expression of P16 protein in primary hepatocellular carcinomas]

The aim of the present study was to determine whether p16 gene is involved in the genesis of primary hepatocellular carcinoma (HCC). Twenty-five primary HCC tumor and corresponding non-tumor liver tissue specimens were examined for P16 gene alterations. The identification of deletion of p16 gene exon 1 and exon 2 was performed using comparative multiplex polymerase chain reaction (PCR) analysis. The point mutation of p16 gene exon 2 was investigated by single strand conformational polymorphism(SSCP) analysis, and the status of p16 gene methylation was screened using PCR-based methylation analysis. Moreover, 35 parafin specimens of primary HCCs with corresponding non-tumor liver tissues, including the 25 cases described above for screening of p16 gene alterations, were investigated also for P16 protein expression by using immunohistochemical analysis. The results of comparative multiplex PCR analysis showed that 12% (3/25) p16 gene deletions, including homozygous deletions in 2 tumors and hemizygous deletion in 1 tumor, were found in the primary HCCs samples. No point mutation was identified in the remaining 22 tumor samples without p16 gene deletions by using SSCP analysis. Hypermethylation was detected in 24% (6/25) of tumor samples by PCR-based analysis. However the corresponding non-tumor liver tissue specimens were always unmethylated at p16 locus. Loss of P16 protein expression, detected by immunohistochemistry, occurred in 16 of 35 (45.7%) tumor samples, whereas all the non-tumor liver tissue specimens showed positive p16 staining. These results indicate that inactivation of p16 gene is relevant to the genesis of HCC.

Self-assembled monolayers of rigid thiols

The preparation, structure, properties and applications of self-assembled monolayers (SAMs) of rigid 4-mercapto-biphenyls are briefly reviewed. The rigid character of the biphenyl moiety results in a molecular dipole moment that affects both the adsorption kinetics on gold surfaces, as well as the equilibrium structure of mixed SAMs. Due to repulsive intermolecular interaction, the Langmuir isotherm model does not fit the adsorption kinetics of these biphenyl thiols, and a new Ising model was developed to fit the kinetics data. The equilibrium structures of SAMs and mixed SAMs depend on the polarity of the solution from which they were assembled. Infrared spectroscopy suggests that biphenyl moieties in SAMs on gold have small tilt angles with respect to the surfaces normal. Wetting studies shows that surfaces of these SAMs are stable for months, thus providing stable model surfaces that can be engineered at the molecular level. Such molecular engineering is important for nucleation and growth studies. The morphology of glycine crystals grown on SAM surfaces depends on the structure of the nucleating glycine layer, which, in turn, depends on the H-bonding of these molecules with the SAM surface. Finally, the adhesion of PDMS cross-linked networks to SAM surfaces depends on the concentration of interfacial H-bonding. This non-linear relationship suggests that the polymeric nature of the elastomer results in a collective H-bonding effect.

Plasminogen activator inhibitor-1 fused with erythropoietin (EPO) mimetic peptide (EMP) enhances the EPO activity of EMP

Erythropoietin (EPO) mimetic peptide (EMP) encoding sequence was inserted into the gene of plasminogen activator inhibitor-1 (PAI-1) between Ala348 and Pro349 (P2'-P3'), generating a novel gene, PAI-1/EMP (PMP). This was cloned into pET32a expression vector, fused with TrxA peptide in the vector, and a 63-kDa protein was expressed in inclusion bodies with an expression level >50%. The TrxA/PMP protein was purified by Ni-NTA-agarose metal-ligand affinity chromatography to a purity >90%, showing a single, silver-stained band on SDS-PAGE. Using a reticulocyte counting assay, the EPO activity of PMP was determined to be 5,000 IU/mg, 2,500-fold that of EMP.

Selective activation of liver X receptor alpha by 6alpha-hydroxy bile acids and analogs

We have found that certain natural 6alpha-hydroxylated bile acids are receptor-specific activators of nuclear liver X receptor alpha (LXRalpha) (NR1H3), a nuclear receptor regulating the expression of the cholesterol 7alpha-hydroxylase gene, coding for the rate-limiting enzyme in the major pathway of bile acid synthesis. The LXR homolog, ubiquitous nuclear receptor (UR/LXRbeta) (NR1H2), was also activated by these bile acids, but at higher concentrations than for LXRalpha. Synthetic 6alpha-hydroxylated bile acid analogs were synthesized with LXRalpha-selective agonistic activity, with potential to modulate cholesterol catabolism in hypercholesterolemia.

Accelerated replicative senescence of medial smooth muscle cells derived from abdominal aortic aneurysms compared to the adjacent inferior mesenteric artery

BACKGROUND

Abdominal aortic aneurysms (AAAs) are associated with aging and atherosclerosis. AAAs arise through a degenerative process characterized in part by depletion of medial smooth muscle cells (SMC), suggesting that generalized aging and SMC senescence represent potential mechanisms contributing to aneurysmal degeneration. It is not yet known whether SMC from AAA tissue exhibit a difference in proliferative capacity compared to SMC from nonaneurysmal vessels or to what extent such differences might be due to aging alone or other patient-specific factors.

MATERIALS AND METHODS

Aneurysm wall tissues were obtained from 15 patients undergoing AAA repair. In each case, a segment of the adjacent (nonaneurysmal) inferior mesenteric artery (IMA) from the same patient was used as a control. Paired AAA- and IMA-derived SMC strains were obtained by explant techniques and their proliferative capacities were compared during serial passage in culture.

RESULTS

Sustainable SMC cultures were established from all IMA explants but from only 9 of 15 AAAs (P < 0.05). The interval required to achieve primary explant growth was longer for AAAs than IMAs (16.4 +/- 2 vs 6.4 +/- 1 days; P < 0.001), but it was unrelated to patient age, gender, or aneurysm size. AAA-derived SMC appeared larger and rounder than the corresponding IMA-derived SMC, even after repeated passage in culture, and their maximal proliferation was reduced by 44.2 +/- 8% (n = 5 pairs, P < 0.05). Serum-stimulated [(3)H]thymidine uptake in AAA-derived SMC was also reduced by 54.9 +/- 7% (n = 5 pairs, P < 0.01), but flow cytometry revealed no differences in SMC viability, apoptosis, or necrosis. While IMA-derived SMC continued to proliferate beyond passage 20 during serial subculture, all AAA-derived SMC developed replicative senescence by passage 12.

CONCLUSIONS

AAA-derived SMC exhibit a distinct morphologic appearance in culture, a diminished proliferative capacity compared to SMC from the adjacent IMA, and a limited in vitro life span. These differences reflect an intrinsic alteration in SMC growth capacity independent of age alone. Tissue-specific processes leading to accelerated replicative senescence may therefore contribute to the selective medial SMC depletion observed in AAAs.

[Clinical observation on treatment of thyrotoxic exophthalmos with jiayanxiao plus tapazole]

OBJECTIVE

To study the therapeutic effect of Jiayanxiao (JYX) on thyrotoxic exophthalmos.

METHODS

Forty-three patients were divided randomly into two groups, the 31 Patients in the treated group were treated with JYX plus tapazole, and the 12 patients in the control group were treated with prednisone plus tapazole. The therapeutic course of both groups was 3 months. The symptoms, eye signs, thyroxin level, and other routine laboratory parameters as well as the adverse effect of the therapy were observed and compared between two groups.

RESULTS

The total effective rate in the treated group was 80.6%, which was obviously higher than that in the control group (50.0%, P < 0.05). Effect of the treated group in lowering degree of exophthalmos was superior to that of the control group. Effects in elevating vision, decreasing palpebral fissure altitude and lowering serum T3, T4 contents in the two groups were similar (P > 0.05). Moreover, the treated group showed better efficacy in improving clinical symptoms with less adverse effect.

CONCLUSION

The therapeutic effect of JYX in treating thyrotoxic exophthalmos is ensured.

[The effects of cyclin E on the growth and other cell cycle related genes of breast carcinoma cells MCF-7]

OBJECTIVE

To investigate the effects of cyclin E in high and low expression on the cell growth and other cell cycle associated genes of MCF-7 cells.

METHODS

Eukaryotic expression vehicles of sense and antisense cyclin E were constructed and transferred into the MCF-7 cell line using lipofectAMINE. The integration and expression of cyclin E were conformed by Southern and Western blot. The cells growth was observed and the changes in cell cycle were analyzed by flow cytometry. The expression of other cell cycle associated genes was assayed using Western blot.

RESULTS

A high expression of cyclin E enabled to promote the cell growth and DNA synthesis and accelerated the proceeding of G(1) phase to S phase, It also promoted the phosphorylatin of pRB and up-regulate the expression of p27 while a low expression of cyclin E showed an opposite effect.

CONCLUSION

Different expression of cyclin E enables to affect growth of MCF-7 cell by the changes of cell cycle related genes.

A three-dimensional model of the delta-opioid pharmacophore: comparative molecular modeling of peptide and nonpeptide ligands

A comparative molecular modeling study of delta-opioid ligands was performed under the assumption that potent peptide and nonpeptide agonists may have common three-dimensional (3D) arrangement of pharmacophore groups upon binding to the delta-receptor. Low-energy conformations of the agonists 7-spiroindanyloxymorphone (SIOM) and 2-methyl-4a-alpha-(3-hydroxyphenyl)-1,2,3,4,4a,5,12, 12a-alpha-octahydro-quinolino[2,3,3-g]isoquinoline (TAN-67), and a partial agonist oxomorphindole (OMI) were determined by high-temperature molecular dynamics (MD). A good spatial overlap was found for the pharmacophore groups of SIOM, TAN-67, and OMI, including the basic nitrogen, phenol hydroxyl, and two aromatic ring. Based on this overlap we proposed a 3D pharmacophore model for nonpeptide delta-opioid agonists with a distance of 7.0 +/- 1.3 A between the two aromatic rings and of 8.2 +/- 1.0 A between the nitrogen and phenyl ring. The potent and highly delta-opioid receptor selective agonist [(2S,3R)-TMT(1)]DPDPE, which shares global backbone constraints of the 14-membered disulfide cycle and a strong preference for the trans rotamer of the TMT(1) side chain, was chosen as a peptide template of the delta-opioid pharmacophore. Extensive MD simulations at 300 K with the AMBER force field were performed for [(2S,3R)-TMT(1)]DPDPE and the less potent [(2S, 3S)-TMT(1)]DPDPE analogue. Multiple MD trajectories were collected for each peptide starting from the x-ray structures of DPDPE and [L-Ala(3)]DPDPE and from models proposed in the literature. Low-energy MD conformations were filtered by the nonpeptide pharmacophore query and then directly superimposed with SIOM, OMI, and TAN-67. Two conformers of [(2S,3R)-TMT(1)]DPDPE that showed the best overlap with the nonpeptide pharmacophore (rms deviation </= 1. 0 A for N,O atoms and centroids of two aromatic rings) were selected as possible delta-receptor binding conformations. These conformations have similar backbone structures, and trans rotamers of the TMT(1) side-chain group. They are reasonably close to the crystal structure of [L-Ala(3)]DPDPE, and differ significantly from the crystal structure of DPDPE. The conformer with a gauche(-) rotamer of Phe(4) is most consistent with structure-activity relationships of delta-opioid peptides. The proposed 3D models were used for rational design of new nonpeptide delta-receptor ligands.

Fatigue in an older population

OBJECTIVES

Fatigue is a common symptom that has not been studied well in the older populations. The purpose of this pilot study was to examine the epidemiology of fatigue symptoms in relation to demographic and medical characteristics of older patients in a long-term care setting.

DESIGN

A cross-sectional interviewer-assisted survey.

PARTICIPANTS/SETTING

A total of 199 ambulatory older residents of a single residential care facility.

MEASUREMENTS

Along with medical and demographic characteristics, the survey included mental status (Folstein), activities of daily living (Katz and Lawton), depression (Yesavage GDS), a 3-minute walk, a 7-item pain scale, and the modified Piper Fatigue Scale.

RESULTS

One-hundred ninety-nine (65%) of 308 potential subjects completed the study (mean age 88 years, 82% female). Of these 199 subjects, 195 (98%) reported some fatigue symptoms (median duration 44 weeks). Significant (P < .0005) relationships were found between fatigue and GDS (r = 0.57), 3-minute walk (r = -0.29), Lawton IADLs (r = 0.31), pain (r = 0.36), and number of medications (r = 0.26). No significant relationships were found between fatigue and age, sex, Folstein score, or number of medical diagnoses. Multivariate regression analysis identified GDS, pain, number of medications and 3-minute walk as significant predictors of fatigue intensity (multiple R = 0.68, r2 = 0.46, P < .02).

CONCLUSIONS

Fatigue is a symptom often found among older residents of a residential facility and has important implications for quality of life. Fatigue is poorly recognized and probably undertreated in older people.

Modulation of endocrine systems and food intake by green tea epigallocatechin gallate

Green tea polyphenols, especially the catechin, (-)-epigallocatechin gallate (EGCG), have been proposed as a cancer chemopreventative based on a variety of laboratory studies. For clear assessment of the possible physiological effects of green tea consumption, we injected pure green tea catechins ip into rats and studied their acute effects on endocrine systems. We found that EGCG, but not related catechins, significantly reduced food intake; body weight; blood levels of testosterone, estradiol, leptin, insulin, insulin-like growth factor I, LH, glucose, cholesterol, and triglyceride; as well as growth of the prostate, uterus, and ovary. Similar effects were observed in lean and obese male Zucker rats, suggesting that the effect of EGCG was independent of an intact leptin receptor. EGCG may interact specifically with a component of a leptin-independent appetite control pathway. Endocrine changes induced by parenteral administration of EGCG may relate to the observed growth inhibition and regression of human prostate and breast tumors in athymic mice treated with EGCG as well as play a role in the mechanism by which EGCG inhibits cancer initiation and promotion in various animal models of cancer.

Carcinoma-associated antigens MK-1 and CEA in urological cancers

BACKGROUND

The MK-1 antigen, recognized by monoclonal antibody FU-MK-1, is widely associated with human carcinomas. However, the expression and distribution of MK-1 in urological cancers is not well known.

MATERIALS AND METHODS

We examined the expression of MK-1 in 10 urological tumor cell lines using flow cytometry and reverse transcription-polymerase chain reaction (RT-PCR) and in 15 cancer tissue specimens by immunohistochemical staining, and then compared it with that of carcinoembryonic antigen (CEA).

RESULTS

When analyzed by flow cytometry, MK-1 was positive in 2 out of 3 bladder, 3 out of 3 prostate and one out of 4 renal tumor cell lines, whereas CEA was negative in all the 10 tumor cell lines. RT-PCR confirmed the presence of MK-1 mRNA in all the six MK-1-positive tumor cell lines. An immunohistochemical study demonstrated that MK-1 was positive in 2 out of 5 bladder, 2 out of 5 prostate and one out of 5 renal cancer tissues. Again, however, CEA was negative in all the 15 urological cancer tissues tested.

CONCLUSION

These findings suggest that MK-1 seems to be a useful biological marker for malignant urological tumors, especially in cases of bladder and prostate cancer.

Establishment and pathological study of models of chronic obstructive pulmonary disease by SO2 inhalation method

OBJECTIVE

To establish rat models of chronic obstructive pulmonary disease (COPD) and study the pathological characteristics of airflow obstruction.

METHOD

SO2 inhalation method was used to establish rat models. After exposure to SO2 for 7 weeks, peak expiratory flow (PEF), peak inspiratory flow (PIF), intratracheal pressure (IP) and IP slope in rat were measured by Maclab data recording and analysis system. Experimental rats with PEF less than 80% of the mean of the normal rats were classified as airflow obstructed, while those with PEF greater than 80% of mean of normal rats were non-obstructed. Pathological changes in airway and lung tissue were compared between these two groups.

RESULT

In experimental animals, PEF was significantly decreased (P < 0.005) and IP slope increased (P < 0.001) as compared with normal rats. Epithelial damage, goblet cell hyperplasia and inflammatory cell infiltration in cartilaginous bronchi were more remarkable in experimental rats with airflow obstruction than those without airflow obstruction (P < 0.001, < 0.01, < 0.001, respectively). Furthermore, pathological changes in airway lumen, epithelium and airway wall in membranous and respiratory bronchioles were more marked in experimental rats with airflow obstruction than those without airflow obstruction (P < 0.001 or P < 0.05). There was a negative correlation between PEF values and epithelial hyperplasia, goblet cell hyperplasia, inflammatory cell infiltration, smooth muscle hyperplasia and mucous plug in membranous and respiratory bronchioles (P < 0.001 or P < 0.05).

CONCLUSION

SO2 inhalation may cause chronic bronchitis with airflow obstruction, i.e. COPD in rats. COPD was induced in 64% (16 of 25) of the experimental group rats.

Antidiuretic effects of a factor in brain/corpora cardiaca/corpora allata extract on fluid reabsorption across the cryptonephric complex of Manduca sexta

Extracts of the brain/corpora cardiaca/corpora allata (Br/CC/CA) complex of Manduca sexta larvae elicit an antidiuretic effect, measured by an increase in fluid reabsorption across the cryptonephric complex of larval M. sexta. Separation of the extract by reversed-phase liquid chromatography gave two fractions with antidiuretic effects. The more potent of these two factors was further characterized for its effects on the cryptonephric complex. Its antidiuretic effect is not inhibited by bumetanide, a drug that inhibits M. sexta diuretic hormone (Mas-DH)-stimulated fluid reabsorption. These data indicate that the mechanism of the antidiuretic effect of the factor is different from that of Mas-DH on the cryptonephric complex. The basal reabsorption of the cryptonephric complex is blocked when treated on the lumen side with bafilomycin A(1), an inhibitor of the H(+)-ATPase, or with amiloride, an inhibitor of the H(+)/K(+) antiporter. However, the antidiuretic-factor-stimulated fluid reabsorption is not affected by either bafilomycin A(1) or amiloride. The increase in reabsorption triggered by the semi-purified factor can be inhibited by Cl(−) channel blockers or by removing Cl(−) from the lumen side of the cryptonephric complex. It appears that this factor activates a Cl(−) pump associated with the cryptonephric complex. Forskolin mimics the effect of this factor on fluid reabsorption, and the effect of forskolin is not inhibited by bumetanide. A selective and potent inhibitor of protein kinase A, H-89, also inhibits antidiuretic-factor-stimulated fluid reabsorption. Addition of the factor to cryptonephric complexes maintained in vitro caused a significant increase in cyclic AMP levels extracted from these tissues compared with values for controls. These data suggest that the antidiuretic effect of the factor in Br/CC/CA extract is mediated by cyclic AMP.

[The gene expression of some cytokines and collagen proteins in rat bone tissue is related to estradiol (E2) and age]

30 female SD rats (3 months old) are equally divided into three groups: ovariectomy (OVX) rats, sham-operated (SHO) rats and 17 beta estradiol (E2) treated OVX rats. For each group, mRNA was isolated from long bone at one month and three months after surgery, respectively. mRNA was reverse transcribed into single strand cDNA and then used as a probe hybridizing to the DNA fragments of col I alpha(1), col I alpha(2), col III, col V, fibronectin, IL-1, IL-6, TGF-beta, LIF, TNF-alpha, TNF-beta by reverse northern and dot blot hybrization. The housekeeping gene, gapdh, was used as an internal control. The results show that in bone of rat, the stable expression of col I alpha (1), col I alpha(2) and col III are related to age not ovariectomy, while supplement with E2 can inhibit the expression of col III and col I alpha(2) completely. The expression of col V, IL-1, IL-6 can be inhibited by estrogen and recovered by removal of estrogen by OVX, then addition of E2 decreased it to the normal level. The expression of TGF-beta is also inhibited by estrogen. It increased during one month after overiectomy, and partially decreased in E2 complemented rat. Three months after surgery, the level of increasing and decreasing is less evident as two months ago. It seems that in young SD rat, the expression of TGF-beta is related to both estrogen and age.

[A study on relationship between hypertension and polymorphism of ACE gene in male Yi people in Liangshan Yi autonomous prefecture, Sichuan]

OBJECTIVE

To explore relationship between polymorphism of ACE gene and hypertension.

METHODS

A cross-sectional study was conducted and PCR technique was used to analyze gene polymorphism.

RESULTS

Genotypes DD, ID and II of ACE gene accounted for 13.0% and 9.7%, 50.9% and 48.4%, and 36.1% and 41.9%, respectively, in the normotensives and hypertensives. Frequencies of I and D alleles for ACE gene were 61.6% and 66.1%, and 38.4% and 33.9%, respectively, in the normotensives and hypertensives. There was no significant difference in distribution of II, ID and DD genotypes and I/D allele frequencies of ACE gene between the hypertensives and normotensives in male Yi people.

CONCLUSION

Association between polymorphism of ACE gene and hypertension was uncertain.

Changes of superoxide dismutase in cultured rat aortic smooth muscle cells (A7r5) by an incubation of vitamin E

Supplementation of antioxidants such as vitamin E and vitamin C as health promotion food is popular recently. Epidemiological studies supported the beneficial effect of these antioxidants because oxygen free radicals have been linked to the process of diseases and aging. The present study evaluated the effect of alpha-tocopherol (vitamin E) on the changes of superoxide dismutase (SOD) in cultured rat aortic smooth muscle cells (A7r5) after a short-term (2 days) or long-term (7 days) incubation. Incubation of A7r5 cells with vitamin E at a concentration of 50 micromol/l for 2 days caused an increase of both the activity and mRNA level of SOD. At higher concentrations, such as 100 or 200 micromol/l, vitamin E failed to enhance SOD more effectively. However, after incubation for 7 days, vitamin E caused a decrease in both the activity and mRNA level of SOD in a concentration-dependent manner. Otherwise, the protein amount of SOD remained the same in these samples regardless of the concentration of vitamin E or the duration of incubation. The obtained results suggest that vitamin E can increase the effect of SOD to result in the beneficial influence of this antioxidant only at low concentration under a short-term supplementation because a down-regulation of SOD was observed in cells receiving a long-term incubation.

Soluble TNF-alpha receptor and IL-1 receptor antagonist elevation in BAL in active pulmonary TB

Accumulating evidence suggests that patients with active pulmonary tuberculosis (TB) have an alveolar inflammation resulting in the release of tumour necrosis factor (TNF)-alpha and interleukin (IL)-1beta in bronchoalveolar epithelial fluid. It was proposed that the levels of these cytokines would correlate with clinical status parameters (extent of pulmonary involvement, fever, and body weight loss) and that their naturally occurring inhibitors would be concomitantly released in the local inflammatory sites. To test this hypothesis lung epithelial lining fluid (ELF) obtained by bronchoalveolar lavage and serum were collected from 29 patients with active pulmonary TB and 15 healthy subjects to determine the levels of these variables using a sandwich enzyme-linked immunosorbent assay (ELISA). ELF levels of TNF-alpha, soluble (s)TNF receptor I (RI), sTNF-receptor II (RII) and interleukin-1 receptor antagonist (IL-1RA) but not IL-1beta, and their serum levels except for sTNF-RII and IL-1beta were significantly higher in TB patients. Nevertheless, only ELF levels of TNF-alpha and IL-1beta were significantly correlated with disease status. No correlation was found between TNF-alpha levels and those of sTNF-RI and sTNF-RII, nor between IL-1beta and IL-1RA in ELF and serum of TB patients, although there was a significant correlation between sTNF-RI and sTNF-RII levels both in ELF and serum. These findings suggest local release of tumour necrosis factor-alpha and interleukin-1beta and a correlation with disease status. Soluble tumour necrosis factor-alpha receptors and interleukin-1beta receptor antagonist, although increased in lung epithelial lining fluid and serum in tuberculosis patients, were not correlated with tumour necrosis factor-alpha and interleukin-1beta or with disease status.

[Studies on chemical constituents of the stem bark of Taxus cuspidata]

In order to study the active constituents in the stem barks of Taxus cuspidata Sieb. et Zucc., led to the isolation and structural determination of three compounds. On the basis of chemical evidences and spectral analysis (UV, IR, 1HNMR, 13CNMR and FAB-MS,) the structures of I, II and III were elucidated as baccatin I 1-hydroxy, taxinine J 2-deacetoxy and beta-sitosterol. Compound I was found from this plant for the first time.

[A study on homozygous deletion, hypermethylation, mutation and expression of p16 gene in human breast cancer]

OBJECTIVE

To investigate the homozygous deletion (HZD), hypermethylation and mutation of p16 gene in human breast cancer and the relationship between the structural alterations of p16 gene and its expression.

METHODS

PCR and PCR-methylation assay with silver staining (PCR-MASS) were used to detect HZD and hypermethylation of p16 gene exon 1 in 60 fresh breast cancers and 24 normal breast tissues adjacent to cancer (as control tissues). PCR-SSCP and DNA sequencing were used for the analysis of p16 gene mutation. Moreover, p16 gene and mRNA were also detected in the 60 cases.

RESULTS

Of the 60 breast cancers, HZD was found in 7 cases, hypermethylation and mutation were found in 16 and 4 cases respectively, and the difference was statistically significant. The positive rates of p16 protein and mRNA in breast cancer were 28/60 and 39/60 respectively.

CONCLUSION

The results demonstrate that several kinds of p16 gene structural changes exist in breast cancer. The structural changes of p16 gene cause abnormal p16 expression, the main mechanisms are hypermethylation, while HZD or mutation are the secondary causes. Abnormal expression of p16 gene then becomes involved in the development and metastasis of breast cancer.

Suppression of experimental abdominal aortic aneurysms by systemic treatment with a hydroxamate-based matrix metalloproteinase inhibitor (RS 132908)

BACKGROUND

Abdominal aortic aneurysms (AAAs) are associated with chronic inflammation, disruption of medial elastin, and increased local production of elastolytic matrix metalloproteinases (MMPs). The purpose of this study was to investigate how treatment with a hydroxamate-based MMP antagonist (RS 132908) might affect the development of experimental AAAs.

METHODS

Male Wistar rats underwent intraluminal perfusion of the abdominal aorta with 50 units of porcine pancreatic elastase followed by treatment for 14 days with RS 132908 (100 mg/kg/day subcutaneously; n = 8) or with vehicle alone (n = 6). The external aortic diameter (AD) was measured in millimeters before elastase perfusion and at death, with AAA defined as an increase in AD (DeltaAD) of at least 100%. Aortic wall elastin and collagen concentrations were measured with assays for desmosine and hydroxyproline, and fixed aortic tissues were examined by light microscopy.

RESULTS

AAAs developed in all vehicle-treated rats, with a mean AD (+/- SE) that increased from 1.60 +/- 0.03 mm before perfusion to 5.98 +/- 1.02 mm on day 14 (DeltaAD = 276.4 +/- 67.7%). AAAs developed in only five of eight animals (62.5%) after MMP inhibition, with a mean AD that increased from 1.56 +/- 0.05 mm to 3.59 +/- 0.34 mm (DeltaAD = 128.1 +/- 18.7%; P <.05, vs vehicle). The overall inhibition of aortic dilatation attributable to RS 132908 was 53.6 +/- 6.8%. Aortic wall desmosine fell by 85.4% in the vehicle-treated rats (1210.6 +/- 87.8 pmol/sample to 176.7 +/- 33.4 pmol/sample; P <.05) but only by 65.6% in the animals treated with RS 312908 (416.2 +/- 120.5 pmol/sample). In contrast, hydroxyproline was not significantly affected by either elastase perfusion or drug treatment. Microscopic examination revealed the preservation of pericellular elastin and a greater degree of fibrocollagenous wall thickening after MMP inhibition, with no detectable difference in the extent of inflammation.

CONCLUSIONS

Systemic MMP inhibition suppresses aneurysmal dilatation in the elastase-induced rodent model of AAA. Consistent with its direct inhibitory effect on various MMPs, RS 132908 promotes the preservation of aortic elastin and appears to enhance a profibrotic response within the aortic wall. Hydroxamate-based MMP antagonists may therefore be useful in the development of pharmacologic approaches to the suppression of AAAs.

Analysis of the steroid binding domain of rat steroid 5alpha-reductase (isozyme-1): the steroid D-ring binding domain of 5alpha-reductase

We have previously shown that the photoactive 4-azasteroid, [1,2 3H]N-4(benzylbenzoyl)-3-oxo-4-aza-4-methyl-5alpha-androst an-17beta-carboxamide is an effective probe of rat steroid 5alpha-reductase (isozyme-1) (5alphaR-1). In the current investigation, PEG-fractionated (6.5%) detergent-solubilized preparations containing 5alphaR-1 activity were ultraviolet (UV)-photolyzed with [3H]-4MABP and subsequently purified by 8.75% preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The fractions corresponding to the radioactive peak following the dye front were analyzed by 10% sodium dodecyl sulfate-polyacrylamide gel electrophoresis and showed the presence of a single, labeled, 26 KDa protein band, the apparent molecular weight of 5alphaR-1. TCA precipitation of the labeled fractions, followed by long-term digestion of the TCA pellet with chymotrypsin and high-performance liquid chromatography analysis, indicated that the majority of the radioactivity eluted with a peak retention time of 55-56 min. Rechromatography of this fraction using a modified gradient (elution 54-55 min), followed by sequence analysis, yielded a single N-terminal tetrapeptide with the sequence, -L-E-G-F-, corresponding to residues 15-18 of the 5alphaR-1 sequence. Site-directed mutagenesis studies indicated that mutant F18L showed an approximately 12-fold increase in the Km for testosterone, whereas the Km for reduced nicotinomide adenine dinucleotide phosphate remained virtually unaltered.

Source of elastin-degrading enzymes in mycotic aortic aneurysms: bacteria or host inflammatory response?

Elastolytic matrix metalloproteinases play a central role in the development of chronic atherosclerotic aortic aneurysms, but mycotic aortic aneurysms are a distinct and unusual form of aneurysm disease caused by bacterial infection. Mycotic aortic aneurysms follow a more rapid and unpredictable course than chronic aneurysm disease and they exhibit a predilection for the suprarenal aorta, further implying unique pathophysiologic mechanisms. The purpose of this study was to examine the nature and source of elastin-degrading enzymes in mycotic aortic aneurysm. Bacterial isolates and aortic tissues were obtained from four consecutive patients undergoing surgical repair of suprarenal mycotic aortic aneurysm. Using an in vitro 3H-labeled elastin degradation assay, elastin-degrading enzyme activity was only observed in the bacteria-conditioned medium from an isolate of Pseudomonas aeruginosa. Elastin-degrading enzyme activity in the aortic tissue homogenate of this patient was abolished by the serine protease inhibitor, phenylmethylsulfonyl fluoride, but it was not suppressed by the metalloproteinase inhibitor, ethylenediamine tetraacetic acid (EDTA). In contrast, elastin-degrading enzyme activity in the bacterial-conditioned medium was decreased by about half by both phenylmethylsulfonyl fluoride and EDTA. Elastin substrate zymography revealed two phenylmethylsulfonyl fluoride-inhibitable elastin-degrading enzyme activities in the aortic tissue homogenate that corresponded to human neutrophil elastase (approximately 30 kDa) and its stable complex with alpha 1-proteinase inhibitor (approximately 80 kDa), but no activity attributable to Pseudomonas elastase, a 33-kDa metal-dependent enzyme. Human neutrophil elastase was readily detected throughout mycotic aortic aneurysm tissues by immunohistochemistry, but elastolytic metalloproteinases were only occasionally observed. The results of this study suggest that the elastin-degrading enzyme produced in mycotic aortic aneurysm are largely serine proteases of host neutrophil origin, rather than elastases produced by the infecting microorganisms or the macrophage-derived metalloproteinases typically observed in atherosclerotic aneurysm disease. Further studies will be needed to extend these findings to a larger number of patients with mycotic aortic aneurysm and those caused by additional microorganisms.

Pharmacologic suppression of experimental abdominal aortic aneurysms: acomparison of doxycycline and four chemically modified tetracyclines

BACKGROUND

Matrix metalloproteinases (MMPs) likely contribute to the degradation of medial elastin in abdominal aortic aneurysms (AAAs), and tetracycline antibiotics exhibit MMP-inhibiting properties. The purpose of this study was to compare the effects of doxycycline and several non-antibiotic chemically modified tetracyclines (CMTs) in a rat model of elastase-induced AAA.

METHODS

Fifty-two male Wistar rats underwent intraluminal perfusion of the abdominal aorta with porcine pancreatic elastase. The rats then were treated for 7 days with subcutaneous injections of saline solution, different doses of doxycycline, or 1 of 4 different CMTs. The aortic diameters were measured with microcalipers, and the fixed tissues were examined by means of light microscopy. Gelatin zymography was used to assess the MMP activity in the aortic tissue extracts.

RESULTS

The mean aortic diameter in the control group increased by 126% +/- 14% on day 7 (from 1.57 +/- 0.04 mm to 3.54 +/- 0.27 mm; P <.05), and 5 of 6 animals (83%) had AAAs. Doxycycline appeared to inhibit aortic dilatation in a dose-dependent manner, and AAAs did not develop in any animals. Half-maximal effects were observed at a dose of approximately 6 mg/kg/day, and maximal effects were noted at greater than 30 mg/kg/day. No AAAs were observed in the animals that were treated with CMTs at 15 mg/kg/day. Each of the following CMTs exhibited an efficacy that was similar to that of doxycycline (percent inhibition of aortic dilatation vs control; all P <.05): CMT-3 (47.6%), CMT-4 (38.9%), CMT-7 (47.6%), CMT-8 (54.0%), and doxycycline (51.6%). Tissues from saline solution-treated controls exhibited a transmural inflammatory response and marked destruction of the medial elastic lamellae. Tetracycline derivatives limited the disruption of medial elastin without appearing to alter either the inflammatory response or the rat aortic wall production of metallogelatinases.

CONCLUSION

Tetracycline derivatives suppress the development of AAAs after elastase-induced aortic injury in the rat. The aneurysm-suppressing effects of doxycycline appear to be dose-dependent and distinct from its antibiotic activities, and they coincide with the structural preservation of medial elastin fibers. Further studies are needed to explore the potential of MMP-inhibiting tetracyclines as a novel pharmacologic strategy for the suppression of aortic aneurysms.

[The clinical and enzymatic changes in patients with viral hepatitis G infection]

For the purpose of making sure the clinical significance of hepatitis G virus, RT-nested PCR was applied to detect HGV RNA in 165 hepatitis patients, which included 24 acute hepatitis, 78 chronic hepatitis, 18 hepatitic cirrhosis, 4 hepatocellularcarcinom and 41 HBV and HCV carriers. The results showed that the infection of HGV existed in all kinds of hepatitis patients. Among the acute hepatitis 12.5% (3/24) was HGV RNA positive. 19 (24.4%) cases were HGV RNA positive in chronic hepatitis, among which 4 cases were simply HGV RNA positive (5.13%). The serum ALT level in 3 cases of simple acute HGV patients was between 488 +/- 65 U/L, the value of AST between 452 +/- 71 U/L, the TBiL at about 77.1 +/- 14.3 mumol/L. All these showed that only HGV infection could lead to acute hepatitis. The rising enzyme dropped to normal about a month later in acute hepatitis while HGV RNA would remain. The problem whether HGV infection is caused by simple acute and chronic hepatitis infection is under investigation.

Expression and localization of macrophage elastase (matrix metalloproteinase-12) in abdominal aortic aneurysms

Elastolytic matrix metalloproteinases (MMPs) have been implicated in the pathogenesis of abdominal aortic aneurysms (AAA), a disorder characterized by chronic aortic wall inflammation and destruction of medial elastin. The purpose of this study was to determine if human macrophage elastase (HME; MMP-12) might participate in this disease. By reverse transcription-polymerase chain reaction, HME mRNA was consistently demonstrated in AAA and atherosclerotic occlusive disease (AOD) tissues (six of six), but in only one of six normal aortas. Immunoreactive proteins corresponding to proHME and two products of extracellular processing were present in seven of seven AAA tissue extracts. Total HME recovered from AAA tissue was sevenfold greater than normal aorta (P < 0.001), and the extracted enzyme exhibited activity in vitro. Production of HME was demonstrated in the media of AAA tissues by in situ hybridization and immunohistochemistry, but HME was not detected within the media of normal or AOD specimens. Importantly, immunoreactive HME was specifically localized to residual elastin fragments within the media of AAA tissue, particularly areas adjacent to nondilated normal aorta. In vitro, the fraction of MMP-12 sequestered by insoluble elastin was two- to fivefold greater than other elastases found in AAA tissue. Therefore, HME is prominently expressed by aneurysm-infiltrating macrophages within the degenerating aortic media of AAA, where it is also bound to residual elastic fiber fragments. Because elastin represents a critical component of aortic wall structure and a matrix substrate for metalloelastases, HME may have a direct and singular role in the pathogenesis of aortic aneurysms.

De novo design, synthesis, and biological activities of high-affinity and selective non-peptide agonists of the delta-opioid receptor

On the basis of the structure-activity relationships of delta-opioid-selective peptide ligands and on a model of the proposed bioactive conformation for a potent and selective, conformationally constrained delta-opioid peptide ligand [(2S, 3R)-TMT1]DPDPE, a series of small organic peptide mimetic compounds targeted for the delta-opioid receptor have been designed, synthesized, and evaluated in radiolabeled ligand binding assays and in vitro bioassays. The new non-peptide ligands use piperazine as a template to present the most important pharmacophore groups, including phenol and phenyl groups and a hydrophobic moiety. This hydrophobic group was designed to mimic the hydrophobic character of the D-Pen residues in DPDPE, which has been found to be extremely important for increasing the binding affinity and selectivity of these non-peptide ligands for the delta-opioid receptor over the mu-opioid receptor. Compound 6f (SL-3111) showed 8 nM binding affinity and over 2000-fold selectivity for the delta-opioid receptor over the mu-opioid receptor. Both enantiomers of SL-3111 were separated, and the (-)-isomer was shown to be the compound with the highest affinity for the delta-opioid receptor found in our study (IC50 = 4.1 nM), with a selectivity very similar to that observed for the racemic compound. The phenol hydroxyl group of SL-3111 turned out to be essential to maintain high affinity for the delta-opioid receptor, which also was observed in the case of the delta-opioid-selective peptide ligand DPDPE. Binding studies of SL-3111 and [p-ClPhe4]DPDPE on the cloned wild-type and mutated human delta-opioid receptors suggested that the new non-peptide ligand has a binding profile similar to that of DPDPE but different from that of (+)-4-[((alphaR)-alpha(2S,5R)-4-allyl-2, 5-dimethyl-1-piperazinyl)-3-methoxybenzyl]-N,N-diethylbenzamide (SNC-80), another delta-opioid-selective non-peptide ligand.

Therapeutic potential of tetracycline derivatives to suppress the growth of abdominal aortic aneurysms

Abdominal aortic aneurysms (AAA) represent a potentially lethal disorder associated with aging and atherosclerosis. Although current management of AAA is predicted on early detection and elective surgical repair, routine screening for AAA is infrequent, because most AAA are too small to warrant repair when first detected and because there are no therapeutic approaches proven to suppress aneurysm expansion. Basic research on this problem suggests that chronic inflammation and increased local production of elastin-degrading proteinases play prominent roles in the process of aneurysmal degeneration. Members of the matrix metalloproteinases (MMP) family appear to be the most prominent elastases produced in human AAA, suggesting that unique therapeutic targets might exist for aneurysm disease. Studies using a representative animal model for AAA support this view, providing a means for further development of pharmacological approaches to suppress aneurysm expansion. Indeed, recent work indicates that tetracycline derivatives have the potential to interrupt the progressive connective tissue destruction that occurs in AAA, by virtue of their non-antimicrobial properties as MMP inhibitors, and they do so at clinically achievable dose schedules. These findings support the view that MMPs are potentially important pharmacotherapeutic targets in AAA and, moreover, that tetracyclines might be useful in suppressing aneurysm expansion in vivo. Because tetracycline derivatives offer a number of distinct advantages as MMP inhibitors for patients with small AAA, prospective clinical trials of this novel therapeutic strategy can be anticipated in the near future.

Molecular mechanism of androgen action

Androgens affect the growth and development of a wide variety of cell types in both males and females and produce their effects by binding to androgen receptors, which modulate the transcription of specific genes. Testosterone is the major active androgen circulating in blood, but in many tissues it is metabolized by 5alpha-reductase to 5alpha-dihydrotestosterone, which binds to and activates the androgen receptor. Androgen receptors are members of the nuclear receptor family of transcription factors, and these nuclear receptors control transcription by recruitment of a variety of co-activators and co-repressors. Mutations in the androgen receptor and 5alpha-reductase can affect male sexual development. 5alpha-Reductase is also critical for parturition and fetal survival in mice. Inhibitors of 5alpha-reductase are being used increasingly to treat some androgen-dependent disorders. Because androgens also suppress the growth of certain cancer cells, they might also have a role in treating prostate cancer.

[A study on the coverage, strategy and cost of hepatitis B vaccination in China, 1996]

To understand the coverage, strategy and cost of hepatitis B (HB) vaccination of China in recent years, a randomized two-stage household sampling survey was carried out at 112 Disease Surveillance Points(DSPs) from 25 provinces, autonomous regions and municipalities of China in 1996. Results showed that the rates of HB vaccination coverage among neonates were 96.9% in the urban DSPs and 50.8% in the rural DSPs in 1993-1994, while in 7-9 year-old students both rates were 85.8% and 31.5% in 1994, respectively. Up to 1994, 97.5% of the urban DSPs and 73.9% of the rural DSPs had a neonates vaccination against HB program integrated with routine EPI. Some of the DSPs had a lower neonates coverage due to insufficient amountad unreasonable distribution of the vaccine (used for adults) and high cost. It seems necessary to evaluate the maternal prescreening program regarding the quality of serological testing to HBVMs. Remarkable achievements have been made in terms of strategy development and planning on HB immunization in China.

Progression of LNCaP prostate tumor cells during androgen deprivation: hormone-independent growth, repression of proliferation by androgen, and role for p27Kip1 in androgen-induced cell cycle arrest

The molecular mechanism of androgen-independent growth of prostate cancer after androgen ablation was explored in LNCaP cells. An androgen-dependent clonal subline of the LNCaP human prostate carcinoma cell line, LNCaP 104-S, progressed to a slow growing stage (104-R1) and then to a faster growing stage (104-R2) during more than 2 yr of continuous culture in the absence of androgen. Androgen-induced proliferation of 104-S cells is inhibited by the antiandrogen Casodex, while proliferation of 104-R1 and 104-R2 cells is unaffected by Casodex. This indicates that proliferation of 104-R1 and 104-R2 cells is not supported by low levels of androgen in the culture medium. Compared with LNCaP 104-S cells, both 104-R1 and 104-R2 cells express higher basal levels of androgen receptor (AR), and proliferation of these two cell lines is paradoxically repressed by androgen. After continuous passage in androgen-containing medium, 104-R1 cells reverted back to an androgen-dependent phenotype. The mechanism of androgenic repression of 104-R1 and 104-R2 sublines was further evaluated by examining the role of critical regulatory factors involved in the control of cell cycle progression. At concentrations that repressed growth, androgen transiently induced the expression of the cyclin-dependent kinase (cdk) inhibitor p21waf1/cip1 in 104-R1 cells, while expression of the cdk inhibitor p27Kip1 was persistently induced by androgen in both 104-R1 and 104-R2 cells. Induced expression of murine p27Kip1 in 104-R2 cells resulted in G1 arrest. Specific immunoprecipitates of Cdk2 but not Cdk4 from androgen-treated 104-R1 cells contained both p21waf1/cip1 and p27Kip1. This observation was confirmed by in vitro assay of histone H1 and Rb (retinoblastoma protein) phosphorylation by the proteins associated with the immune complex. Furthermore, inhibition of Cdk2 activity correlated with the accumulation of p27Kip1 and not p21waf1/cip1. From these results we conclude that androgenic repression of LNCaP 104-R1 and 104-R2 cell proliferation is due to the induction of p27Kip1, which in turn inhibits Cdk2, a factor critical for cell cycle progression and proliferation.

[In situ hybrid detection of p16 mRNA in primary breast carcinoma: its clinicopathologic significance]

OBJECTIVE

To investigate the expression of p16 mRNA in primary breast carcinoma and its clinicopathological significance.

METHODS

In vitro transcriptional RNA probe labeled with biotin and in situ hybridization method were used in this study to detect p16 mRNA in the paraffin embedded tissue of human primary breast carcinoma from 120 cases.

RESULTS

85 breast carcinomas showed expression of p16 mRNA with a positive rate of 70.8%. The p16 mRNA expression was not obviously correlated with patient age, tumor size, estrogen and progesterone receptor status (P > 0.05), but the positive rate of 54.4% for the lymph node metastasis group was significantly lower than 85.7% of the non-metastasis group (P < 0.001). Moreover, the positive rate of 58.3% for the poor differentiate invasive duct carcinoma was also lower than that 89.7% for the well differentiated (P < 0.05). The patients after operation were followed up. The mortality of 25% (21/85) in the p16 mRNA positive group was significantly lower than that of the negative group 57% (20/35) (P < 0.01).

CONCLUSION

Abnormal expression of p16 mRNA may play an important role in the development of human breast carcinoma.

[Long-term efficacy of plasma-derived hepatitis B vaccine among Chinese children--a 12-year follow-up]

OBJECTIVE

To evaluate protective efficacy of a plasma-derived hepatitis B vaccine during 12 years after vaccination.

METHODS

A 12-year follow-up of 350 children who participated a randomized, double blind, placebo-controlled trial in 1982.

RESULTS

During the 12 years after vaccination, more vaccinated children had anti-HBs of 10 S/N ratios or more than did the controls. At the 12 years 46.1% of the vaccinated and 33.9% of the controls retained anti-HBs levels of S/N ratios > or = 10 (P < 0.05). However, at 12 years median S/N ratio of anti-HBs of the vaccinated children with detectable anti-HBs was lower than that of the controls (15 vs 36, P < 0.0001). Protective efficacy against HBsAg carriage status at 5-10 years after vaccination varied from 83% to 100%. At 12 years, 14 chronic HBsAg carriers were identified among the controls, whereas only 1 case was noted in the vaccinated group (7.6% vs 0.6%, P < 0.01), account for an efficacy of 92%.

CONCLUSIONS

Protective efficacy against chronic HBsAg carriage was satisfactory at 12 years after vaccination. No evidence was showed to support a booster of hepatitis B vaccine at this time.

Epidermal growth factor receptor activation in androgen-independent but not androgen-stimulated growth of human prostatic carcinoma cells

These studies were undertaken to assess the relative expression and autocrine activation of the epidermal growth factor receptor (EGFR) in normal and transformed prostatic epithelial cells and to determine whether EGFR activation plays a functional role in androgen-stimulated growth of prostate cancer cells in vitro. EGFR expression was determined by Western blot analysis and ELISA immunoassays. Immunoprecipitation of radiophosphorylated EGFR and evaluation of tyrosine phosphorylation was used to assess EGFR activation. The human androgen-independent prostate cancer cell lines PC3 and DU145 exhibited higher levels of EGFR expression and autocrine phosphorylation than normal human prostatic epithelial cells or the human androgen-responsive prostate cancer cell line LNCaP. PC3 and DU145 cells also showed higher levels of autonomous growth under serum-free defined conditions. Normal prostatic epithelial cells expressed EGFR but did not exhibit detectable levels of EGFR phosphorylation when cultured in the absence of exogenous EGF. Addition of EGF stimulated EGFR phosphorylation and induced proliferation of normal cells. LNCaP cells exhibited autocrine phosphorylation of EGFR but did not undergo significant proliferation when cultured in the absence of exogenous growth factors. A biphasic growth curve was observed when LNCaP cells were cultured with dihydrotestosterone (DHT). Maximum proliferation occurred at 1 nM DHT with regression of the growth response at DHT concentrations greater than 1 nM. However, neither EGFR expression nor phosphorylation was altered in LNCaP cells after androgen stimulation. In addition, DHT-stimulated growth of LNCaP cells was not inhibited by anti-EGFR. These studies show that autocrine activation of EGFR is a common feature of prostatic carcinoma cells in contrast to normal epithelial cells. However, EGFR activation does not appear to play a functional role in androgen-stimulated growth of LNCaP cells in vitro.

[Persistence of HB vaccine immune protection and response to hepatitis B booster immunization]

OBJECTIVE

To determine the persistence of immune protection of China-made, plasma-derived HBV vaccine in infants and the time table of booster immunization.

METHODS

Serological effect of 7-year follow-up study and antibody response of an experimental study on booster were detected using radioimmunoassay.

RESULTS

The protective anti-HBs positive rates of 1,018 children, who were vaccinated according to the regimen of three doses of 10 micrograms HBV vaccine, declined from 75.0% during the first two years to 48.2% at 7 years after the first dosages, however, the positive rates for HBsAg and anti-HBc always fluctuated at low frequency. 144 children aged 6 or 7 years old, who received the HBV vaccine in their infancy and were negative for both HBsAg and anti-HBc before booster, were selected from 1,018 children of the follow-up study and boosted with 1 microgram (intradermally) or 2 micrograms (hypodemically) HBV vaccine. Their anti-HBs GMT and anti-HBs positive rate were 190.6 mIU/ml and 89.6% at one month after booster, significantly higher than 14.7 mIU/ml and 54.9% before booster (P < 0.01), and declined back to 25.3 mIU/ml and 75.5% at 12th month; among 65 children with the anti-HBs negative before booster, 40 of them had the level of anti-HBs > or = 100 mIU/ml one month after booster, suggesting the retention of immunological memory in most of them.

CONCLUSIONS

No need for revaccination against hepatitis B at 7th year after the initial immunization due to better persistence of immune protection of the vaccine.

Allele-specific adaptation of poliovirus VP1 B-C loop variants to mutant cell receptors

Previous work has shown that three different mutations in domain 1 of the poliovirus receptor (Pvr), two in the predicted C'-C" ridge and one in the D-E loop, abolish binding of the P1/Mahoney strain. All three receptor defects could be suppressed by a mutation in the VP1 B-C loop of the viral capsid that was present in all 16 P1/Mahoney isolates adapted to the mutant receptors. To identify allele-specific mutations that enable poliovirus to utilize mutant receptors, and to understand the role of the VP1 B-C loop in adaptation, we selected mutant receptor-adapted viruses derived from two P1/Mahoney variants, one which lacks the VP1 B-C loop and one in which the VP1 B-C loop is replaced with the corresponding sequence from the P2/Lansing strain. Six adapted viral isolates were obtained after passage on mutant receptor-expressing cell lines. Sequence analysis revealed that each virus contained three to five mutations, and a total of 18 amino acid changes at 17 capsid residues were identified. Site-directed mutagenesis was used to evaluate the role of these mutations in adaptation to mutant Pvr. The results demonstrate that mutations in the viral canyon floor and rim are allele specific and compensate only for receptor defects in the C'-C" ridge of Pvr, suggesting that these sites interact in the virus-receptor complex. Furthermore, mutations in the VP1 E-F loop suppressed Pvr D-E loop defects, implying that the Pvr D-E loop contacts the VP1 E-F loop. Most of the other mutations mapped to interior capsid residues, some interacting with the fivefold- or threefold-related protomers. These mutations may regulate receptor interaction by controlling the structural flexibility of the viral capsid. In viruses lacking the VP1 B-C loop, single mutations were not sufficient to confer the adapted phenotype, in contrast to the 414 virus, which contains the B-C loop. Although the VP1 B-C loop appeared to be dispensable for adaptation, it may have provided a selective advantage in adaptation of P1/Mahoney to mutant Pvr.

[AFP, uE3, beta-hCG levels applied for prenatal diagnosis of Down's syndrome]

OBJECTIVE

To investigate the relationship between fetal trisomy 21 and alpha fetoprotein (AFP), unconjugated oestriol (uE3) and beta human chorionic gonadotropin (beta-hCG) levels in maternal serum, amniotic fluid and fetal serum.

METHOD

AFP, uE3 and beta-hCG levels in maternal serum, amniotic fluid and fetal serum from 17 pregnancies with fetal trisomy 21 and 131 unaffected control pregnancies were measured between 16 to 28 weeks gestation using radioimmunoassay.

RESULTS

In these pregnancies with fetal trisomy 21, the AFP and uE3 levels in maternal serum, amniotic fluid and fetal serum were lower than those in controls; but beta-hCG levels were higher (P < 0.05).

CONCLUSION

To measure maternal serum AFP, uE3 and beta-hCG levels will be useful in prenatal detection of trisomy 21.

Preputial sebocyte 5alpha-reductase isoform specificity

We determined whether the 5alpha-reductase (5alpha-R) isozyme specificity in rat preputial sebocytes is in accordance with that of sebaceous glands (type 1 isoform) or with that of other genital tract androgen-dependent organs (type 2). Immunostaining indicated expression of type 1 5alpha-R in preputial epithelial cells in the gland as well as in culture. Northern blots and ribonuclease protection assays both showed the presence of the type 1 isozyme in preputial sebocytes, with little if any expression of the type 2 messenger RNA. Ribonuclease protection assay demonstrated that both homogenized preputial gland and freshly dispersed preputial cells express 2-fold more 5alpha-R type 1 messenger RNA than does skin and 7-fold more than cultured preputial cells. Since cultured preputial cells do not fully differentiate in monolayer culture, these findings suggest that 5alpha-R is increasingly expressed as sebaceous cells differentiate. The predominance of the type 1 isoform in preputial sebocytes is important because it indicates programming by a skin- and sebocyte-specific signal in the midst of the genital tract where the type 2 isoform otherwise predominates.

Vascular smooth muscle cell apoptosis in abdominal aortic aneurysms

Apoptosis is a naturally occurring mechanism of cell death that plays an important role in both normal and pathological remodeling of the vessel wall. Abdominal aortic aneurysms (AAA) represent a unique and dramatic example of vessel wall remodeling characterized by degeneration of the elastic media. Although much attention has been focused on the proteolytic mechanisms that underlie elastin and collagen degradation in AAA, recent studies suggest that depletion of medial smooth muscle cells (SMC) makes an important contribution to this disease by eliminating a cell population capable of directing connective tissue repair. As described in this review, these investigations have revealed that SMC depletion in human aneurysm tissues is accompanied by biochemical, morphological and molecular changes consistent with SMC apoptosis. The exact mechanisms responsible for SMC apoptosis in AAA remain to be elucidated, but current evidence indicates that elevated cellular production of p53 and p21 participates in the process. These findings provide an important new starting point for further investigations on the cellular and molecular mechanisms underlying SMC depletion in AAA and how this process might trigger the accelerated progression of aneurysm disease.

Written language production and neuropsychological function in children with traumatic brain injury

OBJECTIVE

To establish the early consequences of traumatic brain injury (TBI) on spontaneous written language production in children by examining writing deficits as a function of injury severity and correlating written performance with neuropsychological data.

DESIGN

Case-control cohort study.

SETTING

Two regional medical centers.

PATIENTS

Seventy-six children, aged 8 to 15 years, with mild, moderate, or severe closed head injury were compared with controls who were individually matched on the premorbid characteristics of age, gender, school grade, behavior, and academic performance.

MAIN OUTCOME MEASURES

Assessment of written language production and neuropsychological function was undertaken approximately 1 month following resolution of posttraumatic amnesia. Case-control differences on 16 measures of spontaneous written narratives were computed.

RESULTS

Factor analysis and conceptual similarities suggested that the measures of written language fell into five domains: Efficiency, Completeness, General Readability, Error, and Vocabulary. A highly significant, moderate correlation between these measures and severity of injury was found. The highest correlations were found for the written language domains of Efficiency and Completeness and the lowest for the Vocabulary domain. Moderate correlations were also found between measures of written language and neuropsychological function.

CONCLUSIONS

At 1 month after resolution of posttraumatic amnesia, written language production in children with TBI is negatively correlated with severity of injury. Some aspects of written language production are affected to a greater extent than others. Considerable common ground was found between written language production and neuropsychological function.

Extremely low awareness of AIDS, sexually transmitted diseases and condoms among Dai ethnic villagers in Yunnan province, China

OBJECTIVE

To assess the awareness of AIDS, other sexually transmitted diseases (STDs), condoms, sources of health information and HIV-related societal risks among Dai villagers in southern Yunnan Province, China.

SUBJECTS AND METHODS

In November-December 1994, a cross-sectional descriptive study, comprising a questionnaire-based survey and focus group discussions, was conducted in three Dai villages in Mengla county; a total of 177 Dai villagers were interviewed in the survey and eight focus group discussions were held. Ethnographic observations provided a composite picture of HIV risks in the area.

RESULTS

Only 18% of respondents had heard of AIDS, and only 25 and 28%, respectively, had heard of STDs or condoms. Furthermore, among these more aware groups, the level of knowledge was low and misconceptions were common. An ability to understand the official language (Mandarin) was the most important predictor of awareness of AIDS, other STDs or condoms. The sources of information in the three Dai villages sampled included TV, videos, radio and magazines, but only TV and videos had a large audience. Even so, these media were mostly in Mandarin and were not used in AIDS education. Travel outside of China was frequent; most villagers (77%) had traveled to Laos and 9% had traveled to Thailand. Societal risks of HIV transmission, such as an increasing incidence of STDs and an active sex industry, were observed in this area.

CONCLUSIONS

Dai villagers in southern Yunnan Province had an extremely low awareness and knowledge of AIDS, other STDs and condoms. Given the high mobility of ethnic villagers to neighboring countries in Southeast Asia and the societal risks of HIV transmission in this area, there is an urgent need to provide accessible education about AIDS and other STDs. Suggestions regarding such health education and the implications of HIV policy-making are discussed.

[Dynamic changes of serum antibody titer and liver ultrastructural pathology in acute sporadic hepatitis E virus infected patients]

7 acute hepatitis E patients were tested for anti-HEV IgM and IgG antibodies by EIA. It revealed that anti-HEV IgM and IgG antibody titers were the highest at day 10-45 of the illness, and anti-HEV IgM declined gradually and totally lost within 2 months. Anti-HEV IgG had a similar condition to anti-HEV IgM, but at 7th month there still had 3 cases (40%) remained to be antibody positive. One case was examined for ultrastructural pathology. The swelling of liver cells on the fortieth day of illness was still to be found, the vacuolation of cytoplasm and condensation of mitochondria were present in liver cells.

Growth suppression of hamster flank organs by topical application of gamma-linolenic and other fatty acid inhibitors of 5alpha-reductase

Certain unsaturated aliphatic fatty acids, such as gamma-linolenic acid, inhibit 5alpha-reductase activity in vitro and in vivo. Hamster flank organ growth, as measured by the increase in the area of pigmented macule, is dependent on androgen. When one of the paired flank organs of a castrated hamster was treated topically with testosterone, the treated organ, but not the contralateral flank organ, became larger and darker. Topical application of gamma-linolenic acid to the testosterone-treated flank organ suppressed this testosterone effect. Other fatty acids that were not inhibitors of 5alpha-reductases were not active. Topical treatment of hamster flank organs with 5alpha-dihydrotestosterone also stimulated the growth of the organ. This 5alpha-dihydrotestosterone-dependent activity, however, was not significantly affected by gamma-linolenic acid, suggesting that flank organ growth was dependent on 5alpha-dihydrotestosterone and that gamma-linolenic acid acted by inhibiting 5alpha-reductase. With intact male hamsters, the endogenous androgen-dependent growth of flank organs is also suppressed by topical treatment with gamma-linolenic acid. The effect of gamma-linolenic acid is localized at the site of its application; topical application of gamma-linolenic acid did not affect the androgen-dependent growth of other organs such as testis, epididymis, seminal vesicle, and prostate. gamma-Linolenic acid, with low toxicity and absence of systemic effect, therefore may be potentially useful for treatment of androgen-dependent skin disorders.

Both lumenal and cytosolic gating of the aqueous ER translocon pore are regulated from inside the ribosome during membrane protein integration

Portions of the nascent chain are exposed to the lumen, the cytosol, or neither at different stages during the cotranslational integration of a protein into the ER membrane, as shown by compartment-specific collisional quenching of fluorophores incorporated into the polypeptide. The opening or closing of each end of the aqueous translocon pore is tightly controlled and occurs in a sequence that does not compromise the membrane's permeability barrier. Surprisingly, these structural changes at the membrane are effected by the transmembrane segment in the nascent protein from inside the ribosome. Thus, the ribosome, not the translocon, first recognizes the transmembrane segment and triggers long-range structural changes at the translocon that may be involved in shifting its function from translocation to integration.

[Mulivariate analysis of prognostic factors in non-small cell lung cancer]

OBJECTIVES

To find independent prognostic factor of non-small cell lung cancer (NSCLC), identify the population with "high-risk" of recurrence and death in resected NSCLC, and direct adjuvant therapy for clinical doctors.

METHODS

85 resected patients from NSCLC were followed up. All patients were subjected to the study by light microscope, immunochemistry, PCR-SSCP method, and DNA image analysis. Thirteen clinical, pathological, and biological factors were analysed by Cox regression model.

RESULTS

The median follow-up period was 47 months. The overall 3-year survival rate was 66% and the overall 5-year survival rate 61%. Cox regression showed significant univariate predictors (P < 0.05) of early recurrence and death for NSCLC were lymphnode status, pTNM, tumor emboli, microvessel count, Ki-67 antigen labeling, DNA relative content and p53 gene mutation. Microvessel count (P < 0.001) and pTNM (P = 0.006) were independent predictors of early recurrence and cancer-death. According to the multivariate model for predicting early recurrence and cancer death, prognostic index (PI) was calculated.

CONCLUSION

The PI may be a useful clinical tool for evaluating prognosis of patients and identifying the population with "high-risk" of recurrence and death in NSCLC.

Synthesis of oligopeptide and peptidomimetic libraries

The elaboration of peptide libraries prepared by either chemical or biological methods in a format useful for discovery of peptides with specific biological activities was first introduced in the 1980s. A virtual explosion of activity in this area has occurred recently, and the basic approaches have been applied to a wide variety of chemistries and for all manner of biological, chemical and physical targets. Recent advances include new synthetic methodologies, new analytical methods, new design methods and new assay procedures.