Nicotine inhibits apoptosis induced by cisplatin in human oral cancer cells

Oral cancer demonstrates a strong epidemiological association with smoking, but little is known about the effect of nicotine on oral cancer cell apoptosis. Nicotine, a major component of cigarette smoke, can regulate cell proliferation and angiogenesis and suppress apoptosis induced by chemotherapeutic drugs. The main aim of this study was to investigate the effects of nicotine on apoptosis induced by cisplatin, which is commonly used to treat advanced oral cancers, in the human oral cancer cell line Tca8113. The cells were stimulated with nicotine in the presence or absence of cisplatin, and apoptosis was assayed. The results showed that nicotine inhibited apoptosis induced by cisplatin. It was also observed that survivin played a role in the inhibitory effect of nicotine on apoptosis. Depletion of survivin reduced the protective effect of nicotine against cisplatin-induced apoptosis. Akt, a physiological survivin kinase, is activated by nicotine. Treatment of Tca8113 cells with the phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 blocked nicotine-induced survivin expression and enhanced cell apoptosis. These studies suggest that exposure to nicotine might negatively impact on the apoptotic potential of chemotherapeutic drugs, and that survivin plays a key role in the anti-apoptotic effect of nicotine. The Akt pathway may be required for nicotine function.

Phase II trial of the epidermal growth factor receptor (EGFR) inhibitor erlotinib (E) in patients (pts) with advanced papillary renal cell carcinoma (pRCC)—SWOG S0317

15516

Background: Clear cell RCC often has mutations of the von Hippel-Lindau (vHL) gene and over expression of vascular endothelial growth factor (VEGF). pRCC has mutations of c-met and not vHL. Pre-clinically, normal vHL expression is associated with greater activity of EGFR inhibitors in clear cell RCC (Clin Can Res 6:1518, 2000). PRCC has no effective treatment. Given the absence of vHL mutations we undertook a study of E in pts with pRCC. Methods: Pts with histologically confirmed advanced or metastatic pRCC with measurable disease received E 150 mg PO QD from day 1 to disease progression, pt refusal, unacceptable toxicity, or a delay of therapy >3 wks. Central path review and tissue submission for vHL gene analysis were required. The primary endpoint was response. Further study of this regimen would be considered if the observed response rate (RR) was =20% (i.e. 5+ observed responses). Results: 52 pts from 27 SWOG and 2 ECOG institutions were registered. 7 pts were ineligible (no path submission-3; incorrect histology-1; no measurable disease-2; scans outside timeframe-1). Central path review is ongoing for 7 pts, leaving 39 pts evaluable for response including 30M/9F with a median age of 60.2 y (range 27.9 to 82.3). Median follow-up was 12.8 months (range 1.5 to 35.4 m). 4 pts had confirmed PRs for a RR of 10% (95% CI: 3 - 24%). Five evaluable patients with inadequate response assessment were assumed to be non-responders. Median OS was 26.9 months (95% CI lower limit 12.8 m, upper limit not yet estimable). Probability of freedom from treatment failure at 6 m is 30% (95% CI: 15–45%). There was one Grade 5 adverse event (AE) of pneumonitis thought to be possibly drug-related and one Grade 4 thrombotic AE. 8 pts experienced Grade 3 AEs common to E including rash, anorexia, diarrhea and fatigue. vHL mutation was observed in two patients with stable disease. Conclusions: Though the observed RR in pts with pRCC receiving E is similar to pts with clear cell RCC we did not see enough responses to warrant further study. As this is the first phase II trial reported (to our knowledge) for the subset of pts with pRCC we have demonstrated that less common and distinct histological subtypes can be independently studied in the cooperative group setting.

[Table: see text]

Dual AKT inhibition with perifosine and GCP enhances apoptosis in prostate cancer: Clinical implications

14096

Background: Genistein combined polysaccharide (GCP) has been shown to exhibit anti-cancer properties in both experimental and clinical models of prostate cancer (CaP). Perifosine is an alkylphospholipid with clinical anti-neoplastic activity. Both agents inhibit the AKT signaling pathway. Methods: Prostate cancer cell lines (LNCaP, LNCaP stably transfected with R273H or P151S p53 mutant allele, cds1, and PC3) were treated with GCP, perifosine, or both. IC50 values were established using the MTT assay. Apoptosis was assessed by flow cytometry, Western blot of PARP cleavage, and caspase activity. Clonogenic potential was assessed by colony assay. Status of AKT, p53, p21, AR and PSA was determined by Western blot. All experiments were performed in triplicate. Results: Perifosine inhibited AKT activity in all the cell lines. GCP had little or no effect on AKT activity but reduced AR and PSA levels. The combination of GCP and perifosine further increased the level of AKT inhibition and maintained inhibition for longer when compared to treatment with perifosine alone. Flow cytometric analysis of LNCaP revealed that combination treatment dramatically increased SubG1 levels (23-fold increase versus a 4.4-fold increase for GCP alone and a 6.5% increase for perifosine alone). Apoptosis was confirmed by PARP and caspase analysis. As single agents, the main effect of GCP or perifosine was to induce growth arrest as shown by a decrease in S-phase and increased p21. The cds1 cell line responded similarly to LNCaP, however, cell lines that expressed mutant p53 or were p53 null were not susceptible to GCP/perifosine-induced apoptosis. Combination treatment further decreased the clonogenic potential in all of the cell lines assessed when compared to treatment with the single agents alone. Conclusions: Treatment with a combination of the AKT inhibitors GCP and perifosine dramatically increases apoptosis and/or inhibits clonogenic potential in several CaP cell lines. The effect of the combination treatment on apoptosis appears to be dependent on p53 status. Clinical validation of these findings is warranted. A clinical trial of hormone therapy with or without GCP/perifosine is presently in development.

No significant financial relationships to disclose.

Regional energetic dysfunction in hippocampal epilepsy

OBJECTIVES

There is increasing evidence for a dysfunctional metabolic network in human mesial temporal lobe epilepsy (MTLE). To further describe this, we evaluated the bioenergetic status in unilateral MTLE inter-regionally and in relation to neuropathology.

MATERIALS AND METHODS

We used whole brain high field (4 T) 31P MR spectroscopic imaging to determine in vivo PCr and ATP, studying n=22 patients (all candidates for hippocampal resection) and n=14 control volunteers. The degree of bioenergetic impairment was assessed by calculating the ratio of PCr to ATP.

RESULTS

Compared to controls, patients demonstrated significant decreases in PCr/ATP from the ipsilateral amygdala and pes (0.84 +/- 0.14, 0.87 +/- 0.10, respectively, patients vs 0.97 +/- 0.15, 0.98 +/- 0.16, controls). In patients, the ipsilateral thalamic energetics positively correlated with contralateral hippocampal energetics. In addition, the ipsilateral thalamic and striatal energetics negatively correlated with hippocampal total glial counts.

CONCLUSIONS

These data are consistent with a view that in MTLE, the bilateral hippocampi, ipsilateral thalamus and striatum are linked in their energetic depression, possibly reflecting the propagation of seizures throughout the brain.

Pore-scale modeling of saturated permeabilities in random sphere packings

We use two pore-scale approaches, lattice-Boltzmann (LB) and pore-network modeling, to simulate single-phase flow in simulated sphere packings that vary in porosity and sphere-size distribution. For both modeling approaches, we determine the size of the representative elementary volume with respect to the permeability. Permeabilities obtained by LB modeling agree well with Rumpf and Gupte's experiments in sphere packings for small Reynolds numbers. The LB simulations agree well with the empirical Ergun equation for intermediate but not for small Reynolds numbers. We suggest a modified form of Ergun's equation to describe both low and intermediate Reynolds number flows. The pore-network simulations agree well with predictions from the effective-medium approximation but underestimate the permeability due to the simplified representation of the porous media. Based on LB simulations in packings with log-normal sphere-size distributions, we suggest a permeability relation with respect to the porosity, as well as the mean and standard deviation of the sphere diameter.

[Study on different responses of rats' small intestine mucous membrane and bladder transitional epithelium in the same carcinogenic urine environment]

OBJECTIVE

To preliminarily verify the tentative idea of replacement of bladder transitional epithelium with small intestine mucous membrane to prevent recurrence of carcinoma of bladder.

METHODS

A certain segment of small intestine was transplanted to the urinary bladder of the same body in 17 rats. Then N-butyl-N-(4-hydroxy-butyl) nitrosamine (BBN) was used to induce carcinoma of bladder. BBN was used to 11 control rats that did not undergo operation.

RESULTS

Bladder carcinoma failed to be found in the transplanted small intestine mucous membrane in all experimental rats except one. After stimulation of BBN, carcinoma of urinary bladder occurred in all rats' bladder transitional epithelium.

CONCLUSION

1) The carcinogenic substances in the urine of rats suffering from BBN-induced bladder carcinoma are carcinogenic only to bladder transitional epithelium and have no effect on small intestine epithelium. 2) Bladder transitional epithelium may be more sensitive to the urine carcinogenic substances and easier to be cancerized than small intestine epithelium. 3) The tentative idea of substitution of small intestine mucous membrane for bladder transitional epithelium to prevent the recurrence of bladder carcinoma is worth further studying.

Tissue tracking allows rapid and accurate visual evaluation of left ventricular function

AIMS

To evaluate the ability of tissue tracking for rapid assessment of left ventricular function by determination of the systolic mitral annular displacement. Tissue tracking is a new echocardiographic modality based on Doppler Tissue imaging allowing rapid visual assessment of the systolic baso-apical displacement of each myocardial segment in apical views by a graded colour display.

METHODS AND RESULTS

We studied 90 patients (69 male, age 60.4 +/- 10.1 years) with different left ventricular function (25 subjects with normal left ventricular function, 25 patients with homogeneous depression of left ventricular function and 40 patients with prior myocardial infarction). Systolic mitral annular displacement was determined by tissue tracking and M-mode echocardiography. Apical two-, three- and four-chamber views were used to determine the mitral annular displacement of six sites. Left ventricular ejection fraction was determined by two-dimensional echocardiography using Simpson's rule. Tissue tracking was possible in all patients. In the 50 patients with normal left ventricular function or homogeneous depression of left ventricular function, mean mitral annular displacement correlated closely with mitral annular displacement determined by M-mode (r=0.99,P <0.001) and with left ventricular ejection fraction (r=0.97, P<0.001). Left ventricular ejection fraction < or = 30% could be predicted with a sensitivity of 98% and a specificity of 78% using a cut-off value of 4.8mm for the mitral annular displacement determined by tissue tracking. In patients with prior myocardial infarction correlation between the mean mitral annular displacement and left ventricular ejection fraction was lower (r=0.87, P<0.001).

CONCLUSION

Systolic mitral annular displacement determined by tissue tracking correlates closely with mitral annular displacement determined by M-mode and with left ventricular ejection fraction. Thus, tissue tracking allows rapid semiquantitative evaluation of global left ventricular function by assessment of systolic mitral annular displacement.

Ligand-stabilized ruthenium nanoparticles: synthesis, organization, and dynamics

The decomposition of the ruthenium precursor Ru(COD)(COT) (1, COD = 1,5-cyclooctadiene; COT = 1,3,5-cyclooctatriene) in mild conditions (room temperature, 1--3 bar H(2)) in THF leads, in the presence of a stabilizer (polymer or ligand), to nanoparticles of various sizes and shapes. In THF and in the presence of a polymer matrix (Ru/polymer = 5%), crystalline hcp particles of uniform mean size (1.1 nm) homogeneously dispersed in the polymer matrix and agglomerated hcp particles (1.7 nm) were respectively obtained in poly(vinylpyrrolidone) and cellulose acetate. The same reaction, carried out using various concentrations relative to ruthenium of alkylamines or alkylthiols as stabilizers (L = C(8)H(17)NH(2), C(12)H(25)NH(2), C(16)H(33)NH(2), C(8)H(17)SH, C(12)H(25)SH, or C(16)H(33)SH), leads to agglomerated particles (L = thiol) or particles dispersed in the solution (L = amine), both displaying a mean size near 2--3 nm and an hcp structure. In the case of amine ligands, the particles are generally elongated and display a tendency to form worm- or rodlike structures at high amine concentration. This phenomenon is attributed to a rapid amine ligand exchange at the surface of the particle as observed by (13)C NMR. In contrast, the particles stabilized by C(8)H(17)SH are not fluxional, but a catalytic transformation of thiols into disulfides has been observed which involves oxidative addition of thiols on the ruthenium surface. All colloids were characterized by microanalysis, infrared spectroscopy after CO adsorption, high-resolution electron microscopy, and wide-angle X-ray scattering.

Effect of benzene, toluene, xylene on the semen quality and the function of accessory gonad of exposed workers

The effects on semen and the function of accessory gonad of workers after short and long term exposure to benzene, toluene, and xylene were examined. The semen and blood of 24 married workers exposed to benzene, toluene, and xylene were collected. Routine sperm characteristic, acrosin activity, and Lactate dehydrogenase C4 (LDH-C4) relative activity were detected. The results showed that benzene, toluene, and xylene were found in the blood and semen of some ex-workers at workplaces where the air concentration of benzene, toluene, and xylene exceeded the maximum allowable concentration (MAC). No such solvents were detected in the blood and semen of workers of the control group. The sperm vitality and sperm motility decreased in the exposed workers. The mean acrosin activity, gamma-GT activity and LDH-C4 relative activity in the exposed workers were lower, and fructose concentration was higher than those in the control. There were negative correlations between sperm vitality, sperm activity, acrosin activity, or LDH-C4 relative activity and working history. These results suggest that the mixture of these solvents could affect the sperm and the function of accessory gonad. This might be one reason of the abnormal pregnancy outcome among the wives of workers exposed to benzene, toluene, and xylene.

[Coarse woody debris and its function in forest ecosystem]

Coarse woody debris (CWD) is an important structural and functional element in forest ecosystem. In this paper, the definition, dynamics, and role of CWD in a forest ecosystem were overviewed. CWD include all woody debris above and under the ground with a diameters > or = 2.5 cm, and mainly comes from the dead trees resulted from competition and disturbances. The biomass of CWD changes like "U" form along with the development of a forest community. The decay rate of CWD is determined by the compound course of the respiration and natural fragmentation. Insects and microorganisms play an important role in the course. CWD basically has two functions in an ecosystem. One is as the nutrition pool for some living creatures, and the other is that the large CWD can form some special habitats for animals and plants. Conclusively these two functions are helpful to reserve the biodiversity and the integrity of ecological process in a natural ecosystem. Gaps are formed while dead trees falling down, and all gaps in a forest succeed one another randomly in the development of a forest ecosystem, which pushes the inner circulation of the forest. Because of the vital roles of CWD in a forest ecosystem, much more attention should be paid in the management of forest ecosystem.

Monte Carlo simulation of morphologies of self-assembled amphiphilic diblock copolymers in solution

The Monte Carlo method has been applied to simulate the process of the self-assembling of amphiphilic diblock copolymers in a selective solvent. The simulations illustrated that the aggregates morphologies of A-b-B diblock copolymers in solution strongly depend on the length of corona-forming segments, i.e., with the decrease of the corona-forming segments, the transition of spherical micelles to rodlike aggregates occurs, which are in accord with the experimental results of Eisenberg and co-workers [Science 268, 1728 (1995); Macromolecules 32, 2239 (1999); 31, 3509 (1998); 29, 6359 (1996); 31, 9399 (1998)].

Identification of CD72 as a lymphocyte receptor for the class IV semaphorin CD100: a novel mechanism for regulating B cell signaling

We have identified the lymphocyte semaphorin CD100/Sema4D as a CD40-inducible molecule by subtractive cDNA cloning. CD100 stimulation significantly enhanced the effects of CD40 on B cell responses. Administration of soluble CD100 markedly accelerated in vivo antigen-specific antibody responses. CD100 receptors with different binding affinities were detected on renal tubular cells (K(d) = approximately 1 x 10(-9)M) and lymphocytes (K(d) = approximately 3 x 10(-7)M). Expression cloning revealed that the CD100 receptor on lymphocytes is CD72, a negative regulator of B cell responsiveness. CD72 thus represents a novel class of semaphorin receptors. CD100 stimulation induced tyrosine dephosphorylation of CD72 and dissociation of SHP-1 from CD72. Our findings indicate that CD100 plays a critical role in immune responses by the novel mechanism of turning off negative signaling by CD72.

CD72, a negative regulator of B-cell responsiveness

The ability of lymphocytes to respond to antigenic or mitogenic stimulation is regulated not only by specific receptor proteins, but also by both positive and negative regulatory proteins that set or fine-tune the threshold for responsiveness. CD72 is one such regulatory protein on B lymphocytes. It is a member of the C-type lectin superfamily and is expressed on the surface of B cells from the pro-B through the mature B-cell stage. Studies with anti-CD72 antibodies have suggested a positive regulatory role for CD72 in B-cell activation. However, the cytoplasmic tail of CD72 contains two potential immunoreceptor tyrosine-based inhibitory motifs, one of which has been shown to recruit the tyrosine phosphatase SHP- 1. These features suggest a negative regulatory role for CD72. We have generated CD72-deficient mice to elucidate the physiological role of CD72 in B-lymphocyte development and activation. Our analyses of these mice and their B-cell compartment demonstrate that CD72 is a nonredundant regulator of B-cell development and a negative regulator of B-cell responsiveness.

4-[3-(5,6,7,8-Tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)phenyl]benzoic acid and heterocyclic-bridged analogues are novel retinoic acid receptor subtype and retinoid X receptor alpha agonists

Aromatic retinoids having a meta-substituted aromatic ring bridge, such as 4-[3-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)phenyl]benzo ic acid and its 3,5-diaryl-substituted 4,5-dihydroisoxazole analogue, function as retinoid receptor panagonists by activating both retinoic acid and retinoid X receptors to induce gene transcription, and thereby provide novel scaffolds for retinoid drug development. Both classes of these ligand-inducible transcription factors are involved in mediating the inhibitory effects of retinoids on cancer cell growth.

sp2-bridged diaryl retinoids: effects of bridge-region substitution on retinoid X receptor (RXR) selectivity

RXR class selectivity and RXR transcriptional activation activity compared to those for the retinoic acid receptor subtypes were enhanced on the 4-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenylethenyl)be nzoic acid scaffold and its 3-methyl analogue by replacing their 1,1-ethenyl bridge by a 1,1-(2-methylpropenyl) or cyclopropylidenylmethylene group.

[A study of the relation between ventricular repolarization duration and autonomic nervous system]

Cardiovascular disease is a growing problem recently. There has been a few attention in the study of ventricular repolarization duration variability. RDV is associated with some cardiac diseases. We studied vagal blockade effects on RDV in urethane-anesthetized rats. To study the relation between ventricular repolarization duration and autonomic nervous system in subjects, we changed the balance of autonomic nervous system by body posture. The HRV and RDV spectral analysis showed that HF peak was modulated by the frequency of controlled respiration. We also found a significant decrease in HFnu and increase in LF/HF in HRV and RDV during vagal blockade. There is a significant increase of LF/HF of subjects in HRV and RDV from supine to tilt, which is consistent with the state of autonomic nervous system. The result of our study is that the ventricular repolarization duration is dependent on the autonomic nervous system. The RDV analysis will be more helpful in the clinic. This approach will provide a more useful noninvasive evaluation of cardiac disease and function.

[Analysis of influence of axial length and keratometric value on the curative effects of excimer laser photorefractive keratectomy for myopia]

OBJECTIVE

To evaluate the influence of axial length (AL) and keratometric value (KV) on the curative effects of excimer laser photorefractive keratectomy (PRK) for myopia.

METHOD

A Keracor-17 excimer laser was used to treat 80 patients (121 eyes) with myopia. The cases were divided into three groups according to the AL and KV: The first group AL > 26 mm, KV <or= 45 D, 49 eyes; the second group AL <or= 26 mm, KV > 45 D, 36 eyes; the third group AL <or= 26 mm, KV <or= 45 D, 36 eyes. The curative effects were investigated.

RESULTS

The mean uncorrected visual acuity was 1.05 +/- 0.31, which had no significant difference among three groups (P > 0.05). The cases with uncorrected visual acuity >or= 0.5 had significant difference between the first and the second group and between the first and the third group (chi(2) = 6.30, P < 0.05). Multiple linear regression and correlative analysis showed that the increase in ocular axis was an unfavorable factor to visual acuity, while the increase in keratometric value was a favorable factor to visual acuity.

CONCLUSION

PRK for treatment of myopia is an effective and safe refractive surgery. When the myopic degrees are identical, the postoperative outcome of myopia with increase in keratometric value as the main pathogeny is better than the myopia with increase in axial length as the main pathogeny.

[A study of ventricular repolarization duration variability and dependence of RTm/RR]

As an important electrophysiological parameter that reflects cardiac depolarization and repolarization process, ventricular repolarization duration has been drawing growing attention. It is influenced by several physiological and pathological factors and associated with several cardiac diseases. We studied repolarization duration variability (RDV) and dependence of RTm/RR among normal subjects of different age-groups, as well as between normal subjects and subjects with cardiac diseases. It was found that RDV and dependence of RTm/RR are related to age. There are significant differences in the slope of RTm/RR, coherence, CV ratio and RDV between normal subjects and subjects with cardiac diseases. The RDV and dependence of RTm/RR can be employed in providing a more useful evaluation of cardiac disease and function in clinical care.

Synovial tissue in rheumatoid arthritis is a source of osteoclast differentiation factor

OBJECTIVE

Osteoclast differentiation factor (ODF; also known as osteoprotegerin ligand, receptor activator of nuclear factor kappaB ligand, and tumor necrosis factor-related activation-induced cytokine) is a recently described cytokine known to be critical in inducing the differentiation of cells of the monocyte/macrophage lineage into osteoclasts. The role of osteoclasts in bone erosion in rheumatoid arthritis (RA) has been demonstrated, but the exact mechanisms involved in the formation and activation of osteoclasts in RA are not known. These studies address the potential role of ODF and the bone and marrow microenvironment in the pathogenesis of osteoclast-mediated bone erosion in RA.

METHODS

Tissue sections from the bone-pannus interface at sites of bone erosion were examined for the presence of osteoclast precursors by the colocalization of messenger RNA (mRNA) for tartrate-resistant acid phosphatase (TRAP) and cathepsin K in mononuclear cells. Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to identify mRNA for ODF in synovial tissues, adherent synovial fibroblasts, and activated T lymphocytes derived from patients with RA.

RESULTS

Multinucleated cells expressing both TRAP and cathepsin K mRNA were identified in bone resorption lacunae in areas of pannus invasion into bone in RA patients. In addition, mononuclear cells expressing both TRAP and cathepsin K mRNA (preosteoclasts) were identified in bone marrow in and adjacent to areas of pannus invasion in RA erosions. ODF mRNA was detected by RT-PCR in whole synovial tissues from patients with RA but not in normal synovial tissues. In addition, ODF mRNA was detected in cultured adherent synovial fibroblasts and in activated T lymphocytes derived from RA synovial tissue, which were expanded by exposure to anti-CD3.

CONCLUSION

TRAP-positive, cathepsin K-positive osteoclast precursor cells are identified in areas of pannus invasion into bone in RA. ODF is expressed by both synovial fibroblasts and by activated T lymphocytes derived from synovial tissues from patients with RA. These synovial cells may contribute directly to the expansion of osteoclast precursors and to the formation and activation of osteoclasts at sites of bone erosion in RA.

CD72-deficient mice reveal nonredundant roles of CD72 in B cell development and activation

CD72, a B cell surface protein of the C-type lectin superfamily, recruits the tyrosine phosphatase SHP-1 through its ITIM motif(s). Using CD72-deficient (CD72-/-) mice, we demonstrate that CD72 is a nonredundant regulator of B cell development. In the bone marrow of CD72-/- mice, there was a reduction in the number of mature recirculating B cells and an accumulation of pre-B cells. In the periphery of CD72-/- mice, there were fewer mature B-2 cells and more B-1 cells. In addition, CD72 is a negative regulator of B cell activation, as CD72-/- B cells were hyperproliferative in response to various stimuli and showed enhanced kinetics in their intracellular Ca2+ response following IgM cross-linking.

Effect of benzene, toluene, xylene on the semen quality of exposed workers

OBJECTIVE

To examine the effects on semen and sperm quality of workers after a short and long term exposure to benzene, toluene, and xylene.

METHODS

The semen and blood of 24 married workers exposed to benzene, toluene, and xylene from shoemaking, spray painting, or paint manufacturing factories were collected. The concentration of benzene, toluene, and xylene in the blood and semen was determined by using headspace chromatographic method. Routine sperm test was carried out and acrosin activity detected.

RESULTS

The results showed that benzene, toluene, and xylene were found in the blood and semen of some ex-workers in a working environment where the air concentration of benzene, toluene, and xylene exceeded the maximum allowable concentration (MAC). This result was not found in workers of the control group. There were also some effects on the quality of semen in the exposed workers. For example, the percentage of semen with liquefaction time exceeding 30 minutes increased. The sperm vitality, motility and acrosin activity decreased. At the same time, there were a positive correlation between liquefaction time and the level of toluene in semen, and a negative correlation between sperm vitality, sperm activity or acrosin activity and working history.

CONCLUSIONS

The results suggested that the mixture could affect the quality of semen and sperm, which might be the main reason of the abnormal pregnancy outcome among the wives of workers exposed to benzene, toluene, and xylene. Further studies are, however, required to confirm these findings.

Three-dimensional pharmacophore hypotheses for the locust neuronal octopamine receptor (OAR3). Part 2: agonists

Three-dimensional pharmacophore hypotheses were built from a set of 43 agonists against octopamine receptor class 3 (OAR3) in locust nervous tissue. Among the 10 chemical-featured models generated by program Catalyst/Hypo, a hypothesis including hydrogen-bond acceptor (HBA), hydrophobic (Hp), and hydrophobic aliphatic (HpA1) features was considered to be important and predictive in evaluating OAR3 agonists. While the ideal and null hypotheses had a cost of 156.40 and 239.20, respectively, the 10 resulting hypotheses possessed costs from 169.89 to 175.81. The best hypothesis that was confirmed to have a 95% chance of true correlation yielded a low RMS of 0.757 and high regression r of 0.933. Active agonists mapped well onto all the features of the hypothesis such as HBA, Hp, and HpA1. On the other hand, inactive compounds were shown to be difficult to achieve the energetically favorable conformation which is found in the active molecules in order to fit the 3-D chemical feature pharmacophore models.

Three-dimensional molecular field analyses of octopaminergic agonists and antagonists for the locust neuronal octopamine receptor class 3

The quantitative structure-activity relationship (QSAR) of a set of 70 octopaminergic agonists and 20 antagonists against octopamine receptor class 3 (OAR3) in locust nervous tissue was analyzed by molecular field analysis (MFA). MFA of these compounds evaluated effectively the energy between a probe and a molecular model at a series of points defined by a rectangular grid. Contour surfaces for the molecular fields are presented. These results provide useful information in the characterization and differentiation of octopaminergic receptor types and subtypes.

[Clinical and experimental study of jianruling in treating hyperplasia of mammary gland]

OBJECTIVE

To observe the therapeutic effect of Jianruling (JRL) on hyperplasia of mammary gland (HMG) and to explore its mechanism in regulating sex hormones.

METHODS

Clinical changes of HMG were observed and serum sex hormones measured before and after JRL treatment. In experimental study, the effect of JRL was estimated by using electron microscope, pathologic and radioimmunoassay.

RESULTS

JRL could not only cure HMG, but also regulate the sex hormone secretion both in HMG patients and in rats. Clinical study showed that the clinical cure rate was 72.5%, and the total effective rate was 90.8%, it demonstrated a significant difference in comparing with the control group, P < 0.01. The estradiol and prolactin levels of patients lowered significantly after JRL treatment, P < 0.05, while progestogen and testosterone increased significantly, P < 0.05, but no significantly change of follicle-stimulating hormone and luteinizing hormone was found. JRL showed marked effect in treating and preventing experimental HMG in rats, it could modulate the secretive function of sex hormone, and improve the construction of mammary gland.

CONCLUSION

JRL has significant effect in treating HMG, it can adjust the endogenous sex hormone level, delay the development of chronic cystic hyperplasia of mammary gland.

[Analysis of T cell subgroup in children with allergic rhinitis]

OBJECTIVE

To observe the different distribution of T cell in peripheral blood between normal children and children with allergic rhinitis.

METHOD

We use the indirect immunofluorescence to make a statistical analysis randomly in 16 children with allergic rhinitis and 20 in control group.

RESULT

CD3, CD4, CD8 in peripheral blood of patients are a lot less than those in normal children.

CONCLUSION

The change of T cell subgroup's distribution is an important process of immune mechanism disturbance and can be used as a monitoring standard in allergic diseases.

[Heat strain for personnel wearing three levels of protective ensembles at moderate and heavy workloads]

The effects of individual protective ensembles and workloads on personnel's physiological heat strain were experienced by personnel in a hot environment (35 degrees C, 55% relative humidity). Six young males performed treadmill tests at both moderate (ML: 1.11 m/s, 5% grade) and heavy (HL: 1.34 m/s, 5% grade) workloads. They wore three levels of protective ensembles: protective mask only (PM), protective clothing only (PC), and full protective ensembles (FP). Tests lasted 60 min and 45 min, respectively, for ML and HL. Physiological measurements included heart rate (HR), rectal (Tre) and skin (Tsk) temperature, sweat rate (SR), and sweat evaporative rate (ER). Differences between the ensembles and the workloads were significant for HR responses. The increase rate in Tre and Tsk, and SR, ER were significantly reduced from PM and PC to FP condition during ML and Hl tests. The sweat evaporation restriction of ensembles and the increase of heat production from exercise are the main factors of enhancing the heat strain.

[Correlations between factors and intraocular pressure following photorefractive keratectomy]

OBJECTIVE

To evaluate the factors related to intraocular pressure (IOP) after excimer laser photorefractive keratectomy (PRK).

METHODS

86 cases 150 eyes of myopia followed over six months after PRK were studied with noncontact tonometer (NCT).

RESULT

After PRK, a decrease in the IOP was observed. Post-operatively, the IOP reading at 1st month was the highest. The reduction of IOP may be related to the decrease in corneal thickness and corneal curvature (r = 0.361, P < 0.01; r = 0.188, P < 0.05). Regression equation for IOP drop (kPa) = - 0.059 - 0.038X(1) + 0.009X(2)[X(1) = ablation depth (microm), X(2) = decrease in corneal curvature (D)].

CONCLUSION

IOP readings after PRK are influenced by corneal thickness, corneal curvature and eye drug times.

[The treatment of rat fulminant hepatic failure by auxiliary partial heterotopic liver transplantation: experimental study]

OBJECTIVE

To confirm the effect of auxiliary partial heterotopic liver transplantation (APHLT) in the treatment of fulminant hepatic failure (FHF).

METHOD

On 30 rat models of FHF, 62% of partial liver grafts were implanted below the host residual liver with 28 successful operations. The survival rate, biochemical test for liver function, (99m)Tc-HIDA liver scintigraphy and pathological changes of the grafts and host livers were studied.

RESULT

The survival rate in 48 hours was 71.4% compared with 0% in 15 FHF animals. 14 days after the operation, the host liver regenerated obviously and the liver function recovered while the graft shrank gradually. 30 days later, the graft became fibrosis completely.

CONCLUSION

Depending on the temporary function support of the graft, the native residual liver could regenerate and restore its function while the graft tended to atrophy.

Quantitative structure-activity studies of octopaminergic agonists and antagonists against nervous system of Locusta migratoria

The quantitative structure activity relationship (QSAR) of octopaminergic agonists and antagonists against the thoracic nerve cord of the migratory locust, Locusta migratoria L., was analyzed using physicochemical parameters and regression analysis. The hydrophobic effect, dipole moment, and shape index were important in terms of Ki: the more hydrophobic, the greater dipole moment, and the smaller shape index of the molecules, the greater the activity. A receptor surface model (RSM) was generated using some subset of the most active structures. Three-dimensional energetics descriptors were calculated from RSM/ligand interaction and these three-dimensional descriptors were used in QSAR analysis. This data set was studied further using molecular shape analysis.

[Expression of nitric oxide synthase in squamous cell carcinoma of tongue and its prognosis]

OBJECTIVE

To study the expression of nitric oxide synthase (NOS) in squamous cell carcinoma of tongue and its prognosis.

METHODS

The NOSI, NOSII and NOSIII of 55 cases of squamous cell carcinoma of tongue were detected by immunohistochemistry.

RESULTS

The expressive rates of NOSI, NOSII and NOSIII were 30.9%, 40.0% and 38.2% respectively. There were significant differences between the patients with and without neck nodal metastasis, and between the patients survival more than 5 years and less than 5 years (P < 0.01), There were differences between G1, G2 and G3 and the clinical stages in NOSII (P < 0.05).

CONCLUSION

The expression of the NOSI, NOSII and NOSIII in squamous cell carcinoma of tongue is raleted to its prognosis and the NOSII plays a more important role in growth, differentiation, metastatic capability and prognosis of the tumor.

[Effect of interleukin-1, interleukin-6 on the intercellular communication of rat thyroid FRTL-5 cells]

We observed the effects of thyrotropin (TSH), interleukin (IL)-1 beta and IL-6 on the intercellular communication of FRTL-5 cells with fluorenscence redistribution after photobleaching (FRAP) analysis. FRTL-5 cells were cultured and exposed to the different concentrations of TSH, IL-1 beta and IL-6 for 12 hours. The mean fluorescence recovery rate (MFRR, %/min) of the cells labelled with carboxyfluocein diacetate (CFDA) after photobleaching was measured with laser scanning cytometry. The MFRR (%/min) of the cells after exposure to TSH was 0.445 +/- 0.033 at the control group, 0.679 +/- 0.054 at the group of 0.1 U/L, 0.950 +/- 0.073 at the group of 1 U/L, and 0.799 +/- 0.082 at the group of 5 U/L, respectively (F = 11.44, P < 0.01). The indicated that TSH could enhance the intercellular communication of FRTL-5 cells. The MFRR after exposure to IL-1 beta was 0.564 +/- 0.032 at the control group, 0.485 +/- 0.042 at the group of 10(3) U/L, 0.445 +/- 0.043 at the group of 10(4) U/L and 0.405 +/- 0.029 at the group of 10(5) U/L, respectively (F = 3.58, P < 0.01). The suggested that IL-1 beta could inhibite the intercellular communication of FRTL-5 cells. IL-6 had no obvious effect on the intercellular communication of FRTL-5 cells.

[The preparing of Bacillus penetrans preparation and their controlling to root-knot nematodes]

In order to make use of B. penetrans the preparation of these bacteria was prepared successfully. Each gram of the specimen contains more than 3.1 x 10(8) spores according to determination by bloodcount plate. The method of its production are: First, infect the larvae of root-knot nematodes with the spores of B. penetrans. Second, inoculate infectable plants with the infected larvae. Third, beat the root-systems of inoculated plants after adding some water. The flowed liquid from a bronze sieve was mixed with the clear water, filtered, precipitated, air-dried under 5-10 degrees C, and grinded into fine powder, When these powder was added into the water which contained the larvae of root-knot nematodes, the spores of B. penetrans adhered to the cuticles of these larvae in 24 h. The pot experiments of tomato, chilli and cockscomb showed that the galls, egg-sacs, females, males and all-stages of larvae produced by the plant inoculated with the larvae infected with B. penetrans are about 75%-80% less than that without these bacteria. Thus it can be seen that the spores of B. penetrans can depress the populations of root-knot nematodes obviously. Therefore, it is a promising preparation for biological control.

Quantitative structure-activity studies of octopaminergic 2-(arylimino)thiazolidines and oxazolidines against the nervous system of Periplaneta americana L

The quantitative structure-activity relationship (QSAR) of octopaminergic 2-(arylimino)thiazolidines (AITs) and 2-(arylimino)oxazolidines (AIOs) against the thoracic nerve cord of the American cockroach, Periplaneta americana L., was analysed using reported physicochemical parameters and regression analysis. The more electron-donating, the less bulky at m-position, and the more hydrophobic the substituent, the greater the activity. The plots of observed log Vmax values against calculated log Vmax values having substituents on the m-position deviated downwards from those of compounds having substituents at the 0- and/or p-positions. The more hydrophobic and the more electron-withdrawing the substituent, the greater the activity. AIO with a 2, 3, 4-trichlorophenyl group (58) was more active than its thiazolidine derivative, 2-(2,3,4-trichlorophenylimino)thiazolidine (38) in terms of Vmax:Vmax of 58 was 30% relative to octopamine (OA), whereas that of 38 has been 9% relative to OA, respectively. Superimposition of energy-minimized OA and 58 revealed structural and conformational similarities that might account for the high activity of 58.

[24 hours ambulatory blood pressure in impaired glucose tolerance patients]

We investigated the change of 24 hours ambulatory blood pressure (ABPM) in impaired glucose tolerance (IGT) patients. 40 IGT patients were divided into two group: normotension and hypertension groups. Each group was matched with normal glucose tolerance (NGT) and non-insulin-dependent diabetes mellitus (NIDDM) group. All the patients were subjected to ABPM and biochemical index examination. The profile of ABPM in IGT patients with or without hypertension was investigated. The change of the 24 hours blood pressure in both normotensive and hypertensive IGT patients was similar with NGT, but there was a tendency that night blood pressure was increased and nocturnal blood pressure was decreased in IGT. The change of ABPM in those with abnormal circadian rhythm was elevated night blood pressure.

Adaptive modification of treatment planning to minimize the deleterious effects of treatment setup errors

PURPOSE

Using daily setup variation measured from an electronic portal imaging device (EPID), radiation treatment of the individual patient can be adaptively reoptimized during the course of therapy. In this study, daily portal images were retrospectively examined to: (a) determine the number of initial days of portal imaging required to give adequate prediction of the systematic and random setup errors; and (b) explore the potential of using the prediction as feedback to reoptimize the individual treatment part-way through the treatment course.

METHODS AND MATERIALS

Daily portal images of 64 cancer patients, whose treatment position was not adjusted during the course of treatment, were obtained from two independent clinics with similar setup procedures. Systematic and random setup errors for each patient were predicted using different numbers of initial portal measurements. The statistical confidence of the predictions was tested to determine the number of daily portal measurements needed to give reasonable predictions. Two treatment processes were simulated to examine the potential opportunity for setup margin reduction and dose escalation. The first process mimicked a conventional treatment. A constant margin was assigned to each treatment field to compensate for the average setup error of the patient population. A treatment dose was then prescribed with reference to a fixed normal tissue tolerance, and then fixed in the entire course of treatment. In the second process, the same treatment fields and prescribed dose were used only for the initial plan and treatment. After several initial days of treatments, the treatment field shape and position were assumed to be adaptively modified using a computer-controlled multileaf collimator (MLC) in light of the predicted systematic and random setup errors. The prescribed dose was then escalated until the same normal tissue tolerance, as determined in the first treatment process, was reached.

RESULTS

The systematic setup error and the random setup error were predicted to be within +/-1 mm for the former and +/-0.5 mm for the latter at a > or = 95% confidence level using < or = 9 initial daily portal measurements. In the study, a large number of patients could be treated using a smaller field margin if the adaptive modification process were used. Simulation of the adaptive modification process for prostate treatment demonstrates that additional treatment dose could be safely applied to 64% of patients.

CONCLUSION

The adaptive modification process represents a different approach for use of on-line portal images. The portal imaging information from the initial treatments is used as feedback for reoptimization of the treatment plan, rather than adjustment of the treatment setup. Results from the retrospective study show that the treatment of individual patient can be improved with the adaptive modification process.

Functional analysis of ribosomal protein L2 in yeast mitochondria

The yeast nuclear gene RML2, identified through genomic sequencing of Saccharomyces cerevisiae chromosome V, was shown to encode a mitochondrial homologue of the bacterial ribosomal protein L2. Immunoblot analysis showed that the mature Rml2p is a 37-kDa polypeptide component of the mitochondrial 54 S large ribosomal subunit. Null mutants of RML2 are respiration-deficient and convert to [rho-] or [rho degrees ] cytoplasmic petites, indicating that Rml2p is essential for mitochondrial translation. RML2 is regulated transcriptionally in response to carbon source and the accumulation of Rml2p is dependent on the presence of the 21 S large rRNA. Site-directed mutagenesis showed that a highly conserved 7-amino acid sequence (Val336 to Asp342) of Rml2p is essential for function. Substitution of Gln for His-343, the most highly conserved histidine in the L2 protein family, caused cold-sensitive respiratory growth but did not affect the assembly of 54 S ribosomal subunits. Mitochondrial protein synthesis was normal in the His343 to Gln (H343Q) mutant grown at the permissive temperature (30 degrees C) and was severely impaired after growth at the nonpermissive temperature (18 degrees C). His343 corresponds to His229 in Escherichia coli L2, which has been implicated in a direct involvement in peptidyl transferase activity. The conditional phenotype of the H343Q mutant indicates that His343 is not essential for peptidyl transferase activity in yeast mitochondria.

Changes in telomerase activity and telomere length during human T lymphocyte senescence

It has been proposed that telomeres shorten with every cell cycle because the normal mechanism of DNA replication cannot replicate the end sequences of the lagging DNA strand. Telomerase, a ribonucleoprotein enzyme that synthesizes telomeric DNA repeats at the DNA 3' ends of eukaryotic chromosomes, can compensate for such shortening, by extending the template of the lagging strand. Telomerase activity has been identified in human germline cells and in neoplastic immortal somatic cells, but not in most normal somatic cells, which senesce after a certain number of cell divisions. We and others have found that telomerase activity is present in normal human lymphocytes and is upregulated when the cells are activated. But, unlike the immortal cell lines, presence of telomerase activity is not sufficient to make T cells immortal and telomeres from these cells shorten continuously during in vitro culture. After senescence, telomerase activity, as detected by the TRAP technique, was downregulated. A cytotoxic T lymphocyte (CTL) cell line that was established in the laboratory has very short terminal restriction fragments (TRFs). Telomerase activity in this cell line is induced during activation and this activity is tightly correlated with cell proliferation. The level of telomerase activity in activated peripheral blood T cells, the CTL cell line, and two leukemia cell lines does not correlate with the average TRF length, suggesting that other factors besides telomerase activity are involved in the regulation of telomere length.