[Comparison between the artificial cochlea signal processing projects]

The four artificial cochlea signal processors are compared with each other in the paper and a new signal processor system is presented.

Cardiac apoptosis in burned rats with delayed fluid resuscitation

Clinical and experimental studies have shown that delayed fluid resuscitation postburn decreases heart function. We hypothesized that apoptosis occurs in the cardiomyocyte in this condition. To investigate this hypothesis, rats were burned, fluid resuscitation was delayed, and the integrity of cardiac genomic DNA in the burned rats was determined with an LM-PCR Ladder Assay kit. DNA fragmentation shown as DNA ladders on gels, the hallmark of apoptosis, was found in the heart tissue of these rats. In the early phase of delayed fluid resuscitation, the nuclear factor kappa B (NF-kappa B) was examined using an electrophoretic mobility shift assay and was found to be activated. In comparison with burned rats with immediate fluid resuscitation, nitric oxide levels in hearts from burned rats with delayed fluid resuscitation were significantly lower (P<0.01). These results suggest that apoptosis may be an important pathway for cardiac injury, which may result from the activation of NF-kappa B and decreased nitric oxide levels.

Novel liquid chromatographic-tandem mass spectrometric methods using silica columns and aqueous-organic mobile phases for quantitative analysis of polar ionic analytes in biological fluids

Use of silica stationary phase and aqueous-organic mobile phases could significantly enhance LC-MS-MS method sensitivity. The LC conditions were compatible with MS detection. Analytes with basic functional groups were eluted with acidic mobile phases and detected by MS in the positive ion mode. Analytes with acid functional groups were eluted with mobile phases at neutral pH and detected by MS in the negative ion mode. Analytes poorly retained on reversed-phase columns showed good retention on silica columns. Compared with reversed-phase LC-MS-MS, 5-8-fold sensitivity increases were observed for basic polar ionic compounds when using silica columns and aqueous-organic mobile phase. Up to a 20-fold sensitivity increase was observed for acidic polar ionic compounds. Silica columns and aqueous-organic mobile phases were used for assaying nicotine, cotinine, and albuterol in biological fluids.

Determination of lysophosphatidic acids by capillary electrophoresis with indirect ultraviolet detection

Lysophosphatidic acid (LPA) is the simplest form of lysophospholipid. Molecular species of LPA have been identified as the potent components in the ovarian cancer activation factor. The elevated plasma LPAs may be used as potential biomarkers for the early detection of ovarian cancer. This paper is the first report on the quantitative analysis of molecular species of LPA using capillary electrophoresis. In this work, the separation of LPAs was achieved within 14 min in an adenosine monophosphate-borate-methanol-water solution, and the measurement was accomplished by indirect UV detection. With LPA (D) as internal standard, the method had linear calibration ranges for LPAs from 2.8 to 75 microM. The detection limits for various molecular species of LPA were from 1.2 to 2.3 microM by the pressure injection at 3.45 kPa for 5 s. The method had been applied to serum fortified with LPA (S), LPA (O), LPA (P), and LPA (M) and the recoveries ranged from 83 to 112%.

[Progress on evaluation criterion of wound healing]

OBJECTIVE

To set up some objective and accurate criteria to evaluate wound healing.

METHODS

Documents about wound healing were reviewed and summarized in detail.

RESULTS

Wound healing rate, wound healing time, histopathology analysis, quantity assay of macrophage, determination of hydroxyproline, proliferation of cell, assay of DNA contents and circle of cells, level of transforming growth factor-alpha, levels of interleukin-1, interleukin-6 and tumor necrosis factor, assay of keratinocyte collagenase-1, level of fibroblast growth factor receptor-1, level of monocyte chemoattractant protein-1 and level of keratinocyte plasminogen activator inhabitor type 2 were selected as the evaluation criteria of wound healing.

CONCLUSION

Wound healing rate, wound healing time and histopathology analysis are direct and efficient criteria of wound healing.

The development of a closed-loop controlled functional electrical stimulation (FES) in gait training

A closed-loop functional electrical stimulation (FES) system is developed to provide hemiplegic patients with a real-time stimulation to their muscles to prevent the drop-foot and the quadriceps weakness from happening during gait training. The FES is controlled by position sensors (ps) and triggered by footswitches (f) with real-time feedback. As the FES receives the signals from these sensors, it adjusts and outputs an optimum set of stimulation parameters automatically. One hemiplegic patient was recruited to conduct clinical evaluation and treated by using the new closed-loop FES system. It was revealed that the mean velocity, cadence, stride length, active ankle motion range, and functional ambulation category (FAC) improved significantly from 0.12 +/- 0.07 ms-1, 40.3 +/- 18.3 steps min-1, 0.35 +/- 0.10 m, 15 degrees, level 2 to 0.42 +/- 0.23 ms-1, 68.2 +/- 19.0 steps min-1, 0.70 +/- 0.22 m, 40 degrees, level 4 respectively for the patient. A paired t-test indicated that differences in the electromyography (EMG) of the tibialis anterior and the quadriceps muscles between the patient's disabled (affected side) foot and normal (unaffected side) foot are not significant (p > 0.05) after 12 weeks of training. It is concluded that this new closed-loop FES system is capable of providing this hemiplegic patient with restoration to regular walking after appropriate gait training. Future studies, including randomized-controlled study, should be implemented to document the efficacy of this system.

Self-induced phase matching in stimulated four-wave mixing in a nonbirefringent single-mode optical fiber

Self-induced phase matching in stimulated four-wave mixing in a nonbirefringent single-mode optical fiber has been observed. It is shown that in a nonbirefringent single-mode fiber the phase matching that is necessary for stimulated four-wave mixing can be accomplished with a combination of self-phase modulation and cross-phase modulation induced by a pump-laser pulse.

A salvianolic acid B-rich fraction of Salvia miltiorrhiza induces neointimal cell apoptosis in rabbit angioplasty model

Apoptosis has been suggested to participate in stabilizing cell number in restenosis. Salvia miltiorrhiza (SM) Bunge which is a Chinese herb widely used for the treatment of cardiovascular disorders contains a potent antioxidant, Salvianolic acid B. To determine whether the antioxidant affects vascular apoptosis, the present study examined the frequency of apoptotic cell death in atherosclerotic plaques and in restenotic lesions of cholesterol-fed rabbits. New Zealand White rabbits were treated with a normal diet (normal), a 2% cholesterol diet (HC), a 2% cholesterol diet and endothelial denudation (HC-ED), a 2% cholesterol diet with 5% water-soluble extract of SM (4.8 g/Kg B.W./day) and endothelial denudation (HC-ED-SM), or with a 2% cholesterol diet containing probucol (0.6 g/kg B.W./day) and endothelial denudation (HC-ED-probucol). Apoptosis and associated cell types were examined in serial paraffin sections by in situ terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling and immunohistochemistry. The expression of p53, an apoptosis-related protein, was also examined. Apoptosis was mainly detected in the neointima of the three groups with endothelial denudation. The percentage of apoptotic cells in SM-treated group (68.5+/-5.9%) was significantly higher than that of normal (0%), HC (1.9+/-1.2%), HC-ED (46.1+/-5.4%), and probucol-treated (32.8+/-3.9%) groups. The SM treatment markedly reduced the thickness of the neointima which was mainly composed of smooth muscle cells with few macrophages. In accordance with the apoptotic cell counts, positive immunoreactivity for p53 was observed in restenotic lesions from HC-ED, SM-treated and probucol-treated groups but not in the intima of the other two groups. These results suggest that the treatment with salvianolic acid B-rich fraction of SM induces apoptosis in neointima which in turn may help prevent the neointimal thickening.

Functional analysis of androgen receptor N-terminal and ligand binding domain interacting coregulators in prostate cancer

Several new androgen receptor (AR) coregulators, including ARA70, ARA55, ARA54, ARA160 and ARA24, associated with the N-terminal or the ligand-binding domain (LBD) of AR, have been identified by our group. We first identified the AR-LBD coregulators ARA70, ARA55, and ARA54. Our previous reports suggest that ARA70 can enhance the androgenic activity of 17 beta-estradiol (E2) and antiandrogens toward AR. It is of interest to compare and determine if the specificity of sex hormones and antiandrogens can be modulated by different coregulators. Our results indicate that, ARA70 is the best coregulator for increasing the androgenic activity of E2. Only ARA70 and ARA55 were able to significantly increase the androgenic activity of hydroxyflutamide, the active metabolite of a widely-used antiandrogen for the treatment of prostate cancer. Furthermore, our results suggest that among the LBD coregulators, ARA70 has a relatively high specificity for AR in the human prostate cancer cell line DU145. Together, our data suggest that the androgenic activity of some sex hormones and antiandrogens can be modulated by selective AR coactivators. In addition to the AR-LBD associated proteins, ARA24 and ARA160 have been identified as AR coregulators, interacting with the AR N-terminal instead of the LBD. Functional analysis revealed that the AR N-terminal coregulator ARA160 could cooperate with the AR LBD-associated coregulator ARA70. Our data indicate that ARA24 could also interact with AR, and that this binding is decreased by an expanding poly-glutamine (Q) length within AR. The length of the poly-Q stretch in the AR N-terminal domain is inversely correlated with the transcriptional activity of AR. Our data suggest that optimal AR transactivation may require interaction of AR with AR coregulators. The identification of factors or peptides that can interrupt androgen-mediated AR-ARA interactions may be useful in the development of better antiandrogens for treating androgen-related diseases, such as prostate cancer.

Regressionally determined vertebral inclination angles of the lumbar spine in static lifts

OBJECTIVE

Our previous study has developed the non-invasive models to predict the vertebral inclination angles by relating the external stick marker angles and radiographic measurements during trunk flexion. Based on these models, the present study attempted to further predict the inclination angles using externally measured body posture (i.e., lumbar posture, trunk flexion angle, knee angle) as well as load handling.

DESIGN

Prediction models of the vertebral inclination angles were developed with a stepwise regression technique. This was done by selecting related postural variables as well as load handling as predictors.

BACKGROUND

The technique of skin-surface stick marker has been investigated for measuring vertebral inclination angles. This technique, however, is rarely systematically validated by radiographic measurement because of concerns over radiation exposure, especially for ergonomical purposes.

METHODS

Twelve healthy men aged 22-31 years were recruited in the experiment. The angles of the vertebral markers and subject's posture were recorded videographically as the subject performed a given task. Prediction models were then developed to express the relationships between the vertebral inclinations and the lifting postures.

RESULTS

The prediction models revealed that the lumbar posture (lordosis or kyphosis) had a statistically significant effect on these inclination angles. Non-linear first-order regression models of the torso angle and the pelvic angle were fit to the transformed vertebral inclination angles (transformed from external stick marker angle), with resulting R(2) values between 0. 86 and 0.92.

CONCLUSIONS

These findings indicate that the vertebral inclination angles can be calculated easily and with relative accuracy on the basis of the externally measured torso and pelvis angles.

RELEVANCE

Measurements of lumbosacral vertebral inclination angles are important in assessing low back stress during lifting. In this study, we used a regression approach to model these angles of the lumbar/sacrum spine in different lumbar postures in the sagittal plane. Our data suggest that the vertebral inclination angles can be calculated easily. These models may be useful to the low back stress evaluation and job design through a biomechanical analysis.

Bacillus cereus group strains, their hemolysin BL activity, and their detection in foods using a 16S RNA and hemolysin BL gene-targeted multiplex polymerase chain reaction system

Hemolysin BL (HBL) is a major virulence factor for Bacillus cereus group strains. It is also a target enterotoxin for the most commonly used B. cereus detection kit, i.e., the B. cereus enterotoxin (diarrheal type) reversed passive latex agglutination (BCET-RPLA) test kit. A survey of the HBL activities and the cytotoxicities to the Chinese hamster ovary (CHO) cells for the B. cereus group strains, however, showed that although only part of the B. cereus group strains are HBL active, all strains show cytotoxicity to the CHO cells. Thus, methods that allow the detection of not only the HBL but also of the B. cereus group strains are important. In this study, by comparison of the gene sequences of the 16S rRNA for B. cereus group and other bacteria strains, we designed primers B16S1 and B16S2 specific to all the B. cereus group strains. In addition, because HBL is a major enterotoxin, we also designed HBL gene-specific polymerase chain reaction (PCR) primers, i.e., Hm1 and Hm2, that generated the same results as those of the hemolysis and BCET-RPLA assays. Primers B16S1/B16S2 and Hm1/Hm2 could be combined into a multiplex PCR system for the simultaneous detection of B. cereus group cells and the possible presence of their HBL enterotoxins. Also, all these PCR systems allowed the detection of n x 10(0) CFU B. cereus cells per g of food sample if an 8-h enrichment step was performed prior to the PCR.

Induction of antitumor immunity with combination of HER2/neu DNA vaccine and interleukin 2 gene-modified tumor vaccine

The therapeutic effects of both cytokine-secreting tumor vaccine and DNA vaccine were studied using mouse MBT-2 bladder cancer cells as a model. Cytokine-secreting MBT-2 cells were obtained by infecting cells with retroviral particles containing interleukin (IL) 2-, IL-4-, or granulocyte-macrophage colony-stimulating factor (GM-CSF)-expression vector. The MBT-2-IL-2 cells were not tumorigenic in syngenic C3H mice at all. Tumor formation decreased significantly for the MBT-2-GM-CSF cells. MBT-2-IL-2, -IL-4, and -GM-CSF cells were killed by irradiation and tested as tumor vaccines. The irradiated MBT2-IL-2 cells could complete protect mice from the growth of the preexisting tumor cells, and the immune memory lasted for 8 months. On the other hand, irradiated MBT-2-IL-4 and MBT-2-GM-CSF cells were less effective. When the loading tumor mass increased, all tumor vaccines lost protective effects. DNA vaccine encoding the tumor antigen neu was additionally tested to improve the therapeutic efficacy. Coinjection of 60 microg pSV-neu DNA was effective in enhancing the antitumor effects of MBT2-IL-2; however, DNA vaccine alone cannot prevent the progression of the preexisting tumor. Immunohistochemical analysis of tumor infiltrate revealed massive increase of CD4+ lymphoid cells in the group of mice treated with both DNA vaccine and IL-2-secreted tumor vaccine. Western blotting demonstrated the presence of anti-neu antibody in the serum from immunized mice. In contrast, combination of DNA vaccine and MBT-2-GM-CSF has no additive effect. The results indicate the combination of DNA vaccine and IL-2-secreting tumor vaccine can additionally improve therapeutic efficacy, and the efficacy is correlated with the increase of CD4+ T lymphocytes and anti-neu antibody.

The cytotoxicity of corrosion products of nitinol stent wire on cultured smooth muscle cells

Although nitinol is one of most popular materials of intravascular stents, there are still few confirmative biocompatibility data available, especially in vascular smooth muscle cells. In this report, the nitinol wires were corroded in Dulbecco's modified Eagle's medium with constant electrochemical breakdown voltage and the supernatant and precipitates of corrosion products were prepared as culture media. The dose and time effects of different concentrations of corrosion products on the growth and morphology of smooth muscle cells were evaluated with [(3)H]-thymidine uptake ratio and cell cycle sorter. Both the supernatant and precipitate of the corrosive products of nitinol wire were toxic to the primary cultured rat aortic smooth muscle cells. The growth inhibition was correlated well with the increased concentrations of the corrosion products. Although small stimulation was found with released nickel concentration of 0.95 +/- 0.23 ppm, the growth inhibition became significant when the nickel concentration was above 9 ppm. The corrosion products also altered cell morphology, induced cell necrosis, and decreased cell numbers. The cell replication was inhibited at the G0-G1 to S transition phase. This was the first study to demonstrate the cytotoxicity of corrosion products of current nitinol stent wire on smooth muscle cells, which might affect the postimplantation neointimal hyperplasia and the patency rate of cardiovascular stents.

Increased corrosion resistance of stent materials by converting current surface film of polycrystalline oxide into amorphous oxide

Current efforts of new stent technology have been aimed largely at the improvement of intravascular stent biocompatibility. Among the chemical characteristics of metallic stents, surface oxide corrosion properties are paramount. Using our unique technique, the currently marketed 316 L stainless steel and nitinol stent wires covered with polycrystalline oxide were chemically etched and then passivated to form amorphous oxide. Excellent metallic-stent corrosion resistance with an amorphous oxide surface was demonstrated in our previous in vitro study. For in vivo validation, we compared the corrosion behavior of different oxide surfaces on various forms of test wires in the abdominal aorta of mongrel dogs using open-circuit potential and cyclic anodic polarization measurements. After conduction, the retrieved test wires were observed under scanning electron microscope. No passivity breakdown was found for wires covered with amorphous oxide, while wires with polycrystalline oxide showed breakdown at potentials between +0.2 to + 0.6 V. It has been proven that severe pitting or crevice corrosion occurred on the surface of polycrystalline oxide, while the surface of amorphous oxide was free of degradations in our experiment. We have demonstrated that this amorphous oxide coating on metallic material provides better corrosion resistance, not only in vitro but also in vivo, and it is superior not only in strength safety but also in medical device biocompatibility.

Synthesis, antibacterial, and cytotoxic evaluation of certain 7-substituted norfloxacin derivatives

We report herein the synthesis and biological evaluation of two series of 7-substituted norfloxacin derivatives. Most compounds tested in this study demonstrated better activity against methicillin-resistant Staphylococcus aureus than norfloxacin. Preliminary in vitro evaluation indicated that the 7-[4-(2-hydroxyiminoethyl)piperazin-1-yl] derivatives 3b-e possess distinct cytotoxicity profiles as compared with their alpha-methylene-gamma-butyrolactone counterparts, 4b,e: i.e., excellent activities against the renal cancer subpanel. Among them, 1-ethyl-6-fluoro-7-¿4-[2-(4-chlorophenyl)-2-hydroxyiminoethyl]-1-p ipe razinyl¿-4-oxo-1,4-dihydro-3-quinolinecarboxylic acid (3d) demonstrated the most significant activities against renal cancer cell lines, with log GI(50) values of -6.40 against CAK-1, -6.14 against RXF 393, and -7.54 against UO-31, compared with a mean log GI(50) value of -5.03.

A comprehensive neurobehavioral and neurophysiological study for low level lead-exposed workers

A comprehensive neurobehavioral and neurophysiological study was performed to evaluate the adverse effect of low level lead-exposure, and to compare the sensibility, easiness of the test methods utilized. The tests were: WHO recommended Neurobehavioral Core Test Battery (NCTB), Autonomic Nouvers System Function (ANS) Test Battery, Brain Electricity Active Mapping (BEAM), and Nerve Conduction Velocity. 44 lead-exposed workers were selected, with 34 age, education degree, family economic level, smoking and drinking matched referents.

RESULT

The mean blood lead concentration of lead-exposed workers was 1.3870 mumol/L, whereas that of referents was 0.6080 mumol/L, the difference was very significant. The negative Profile of Mood State (POMS) score of lead-expose workers was higher than that of referents, whereas the positive POMS score of the referents was higher than that of lead-exposed group, with a covariance analysis. The lead-exposure affected some NCTB test items, such as simple reaction time (SRT), digital symbol (DSY), correct dots (PAC) and total dots (PA). The heart-rate response to Valsalva manoeuvre (HR-V), heart-rate response to deep breathing (HR-DB), and blood-pressure response to immediate standing (BP-IS) were lowered in lead-exposed workers significantly. Some abnormal brain electric waves (dominant beta frequency, semetry-diffuse abnormal and non semetry-diffuse abnormal wave distribution, dominant low wave amplitude) appeared in lead-exposed workers. Left ulnar nerve maximal conduction velocity was significantly lowered in lead-exposed group.

CONCLUSION

The NCTB (including POMS), and ANS function test should be the regular screening battery for low level lead-exposed workers. The threshold blood lead concentration for health surveillance should be 30 micrograms/dL, or 1.4 mumol/L.

Polymorphic CAG and GGN repeat lengths in the androgen receptor gene and prostate cancer risk: a population-based case-control study in China

The length of the polymorphic CAG trinucleotide repeat in the polyglutamine region of the androgen receptor (AR) gene is inversely correlated with the transactivation function of the AR. Because increased androgenic activity has been linked to prostate cancer and because an ethnic variation exists in the CAG repeat length, this polymorphism has been suggested to explain part of the substantial racial difference in prostate cancer risk. We conducted a population-based case-control study in China to investigate whether CAG and other polymorphisms of the AR gene are associated with clinically significant prostate cancer in this low-risk population. Genomic DNA from 190 prostate cancer patients and 304 healthy controls was used for direct sequencing to evaluate the relationship of CAG and GGN (polyglycine) repeat length in the AR gene. Relative to western men, our study subjects had a longer CAG repeat length, with a median of 23 and only 10% of the subjects having a CAG repeat length shorter than 20. Men with a CAG repeat length shorter than 23 (median length) had a 65% increased risk of prostate cancer (odds ratio, 1.65; 95% confidence interval, 1.14-2.39), compared with men with a CAG repeat length of 23 or longer. For the GGN tract (GGT3GGG1GGT2GGCn), based on the sequencing results from 481 samples, we are the first to show that although GGC regions in the polyglycine tract are highly variable, there are no mutations or polymorphisms in the GGT and GGG regions. More than 72% of the subjects had a GGN repeat length of 23, and those with a GGN repeat length shorter than 23 had a 12% increased risk of prostate cancer (95% confidence interval, 0.71-1.78), compared with those with > or = 23 GGN repeats. Our study not only confirms that Chinese men do have a longer CAG repeat length than western men but also represents the first population-based study to show that even in a very low-risk population, a shorter CAG repeat length confers a higher risk of clinically significant prostate cancer. These results imply that CAG repeat length can potentially serve as a useful marker to identify a subset of individuals at higher risk of developing clinically significant prostate cancer. Larger studies are needed to evaluate the combined effect of CAG and GGN repeats. Because of the significance of AR in prostate cancer, investigation of factors that interact with the polyglutamine region of the AR gene to alter AR function and modulate prostate cancer risk is an important area for future research.

Optimal lifting techniques adopted by Chinese men when determining their maximum acceptable weight of lift

The purpose of this study was to identify biomechanically the mechanisms adopted by Chinese men when they psychophysically determined their MAWLs (maximum acceptable weights of lift) in different tasks. Twenty-two healthy Chinese men determined their MAWLs at two lifting vertical ranges and three lifting frequencies. Peak L5/S1 compressive forces, elbow and shoulder peak reactive moments, acceleration effects, and postures were analyzed throughout the lifting acts. The results showed that different lifting techniques were adopted when determining the MAWL at different vertical ranges and frequencies of lifting. Posture analyses showed that a more stooped technique was used in frequent tasks, which would minimize the metabolic cost. For infrequent tasks, subjects accelerated and lifted the load upward and then shortened the moment arm by flexing the elbow and shoulder joints during landing, to compensate for weakness of the upper extremities. The high prelifting acceleration used during the infrequent tasks caused high compressive forces on the L5/S1 disc. These results emphasize the importance of considering the roles of upper extremity strength when designing lifting tasks for Chinese workers.

[Modulation of nerve growth factor on wound healing of burn]

OBJECTIVE

To investigate the effect of nerve growth factor(NGF) on the burn wound healing and to study the mechanism of burn wound healing.

METHODS

Six domestic pigs weighting around 20 kg were used as experimental animals. Twenty-four burn wound, each 2.5 cm in diameter, were induced on every pigs by scalding. Three different concentrations of NGF, 1 microgram/ml, 2.5 micrograms/ml, 5 micrograms/ml were topically applied after thermal injury, and saline solution used as control group. Biopsy specimens were taken at 3, 5 and 9 days following treatment and immunohistochemistry method was used to detect the epidermal growth factor(EGF), EGF receptor (EGF-R), NGF, NGF receptor (NGF-R), NGF, NGF-R, CD68 and CD3.

RESULTS

The expression of EGF, EGF-R, NGF, NGF-R CD68 and CD3 were observed in the experimental group, especially at 5 and 9 days, no expression of those six items in the control group.

CONCLUSION

NGF can not only act directly on burn wound, but also modulate other growth factors on the burn wound to accelerate the healing of burn wound.

Semantic verbal fluency deficit as a familial trait marker in schizophrenia

This study examined neurocognitive deficits as familial vulnerability factors to schizophrenia. Twenty-three Chinese schizophrenic patients, 21 of their non-psychotic siblings and 26 healthy volunteers, matched for age, sex and education, were assessed by using a battery of neurocognitive tests including: Wisconsin Card Sorting Test (WCST), semantic verbal fluency, logical memory, digit span, information, comprehension and similarity. The results showed that siblings had significantly less word output in the verbal fluency test as compared to controls. No significant difference was found between siblings and controls for other tests except that a trend difference was noted for the performance on the similarity test and number of categories completed on the WCST. The verbal fluency abnormality can be considered as a familial trait marker for schizophrenia. Relationships between the residual symptoms after an acute psychotic episode and the magnitude of familial risk were examined. More severe residual symptoms of probands at clinical remission could be predicted by their older age of onset and by better verbal fluency performance in their non-psychotic siblings. This tentatively suggests that patients with a milder genetic form of schizophrenic illness may have a more severe environmental contribution to cerebral insult according to the multifactorial/threshold model. The environmental cerebral insult may cause structural abnormalities leading to incomplete remission of clinical symptoms.

Molecular cloning and characterization of a unique 60 kDa/72 kDa antigen gene encoding enzyme I of the phosphoenolpyruvate: sugar phosphotransferase system (PTS) of Mycoplasma hyopneumoniae

The recombinant clone expressing a 60 kDa (P60) antigen was isolated from Escherichia coli by screening a lambda EMBL3 genomic library using rabbit produced antiserum against Mycoplasma hyopneumoniae. Sequence analysis revealed that an interrupted (by a UGA codon) open reading frame coding for a 72 kDa protein (P72) may contain the P60 antigen gene. Western blot analysis with an anti-P60 monospecific antibody confirmed the presence of a P72 antigen from the total protein of M. hyopneumoniae, and a 72 kDa protein was also expressed in E. coli after changing the codon (UGA to UGG) by site-directed mutagenesis. BLAST (Basic Local Alignment Search Tool) comparison showed that the amino acid sequences of P72 share approximately 70% homology with the phosphotransferase enzyme I (PTSI) of bacteria and other mycoplasma species. The biological function of the P72 cytosolic protein was further confirmed by complementation using an E. coli ptsI mutant. The bacterial phosphoenolpyruvate-sugar phosphotransferase system (PTS) is known to mediate the uptake and phosphorylation of carbohydrates and to be involved in signal transduction. The immune responses of specific pathogen free (SPF) pigs and farm animals toward this unique antigen were observed. The transcription start positions of the PTSI gene were determined in M. hyopneumoniae and E. coli by primer extension experiments and the promoter site was also predicted.

Effects of areca nut extracts on the functions of human neutrophils in vitro

Aqueous extracts of ripe areca nut without husk (ripe ANE) and fresh and tender areca nut with husk (tender ANE) were examined for their effects on the defensive functions of human neutrophils. Exposure of peripheral blood neutrophils to ripe ANE and tender ANE inhibited their bactericidal activity against oral pathogens, including Actinobacillus actinomycetemcomitans and Streptococcus mutans, in a dose-dependent manner. At the concentrations tested, ripe and tender ANEs did not significantly affect the viability of neutrophils as verified by their ability to exclude trypan blue dye. However, both ANEs inhibited the production of bactericidal superoxide anion by neutrophils as measured by cytochrome c reduction. Moreover, the ripe ANE inhibited neutrophils more effectively than did tender ANE. Arecoline, a major alkaloid of areca nut, only exhibited an inhibitory effect on the functions of neutrophils when high concentrations were used. Therefore, arecoline could not be used to explain the inhibitory effects observed for ANEs. In conclusion, our results demonstrated that ripe and tender ANEs reduced the antibacterial activity and the superoxide anion production of neutrophils. This effect may contribute to a less efficient elimination of bacteria from the periodontal environment. Inhibition of the antimicrobial functions of neutrophils may alter the microbial ecology of the oral cavity, and this may be one possible mechanism by which areca nut compromises the oral health of users of areca nut products.

Activity of the caspase-3/CPP32 enzyme is increased in "early stage" myelodysplastic syndromes with excessive apoptosis, but caspase inhibition does not enhance colony formation in vitro

OBJECTIVE

Excessive apoptosis may have a role in the ineffective hematopoiesis and cytopenias observed in myelodysplastic syndromes. The goals of this study were 1) to quantify apoptosis in patients with "early stage" myelodysplasia [including patients with refractory anemia (RA), RA with ringed sideroblasts (RARS), RA with excess blasts and with less than 10% blasts (RAEB(<10))], and in patients with "late stage" myelodysplasia [including RAEB with more than 10% blasts (RAEB(>10)), RAEB in transformation (RAEB-t), and acute myeloid leukemia secondary to myelodysplasia (LAM2)]; 2) to study the activation of the caspase-3/CPP32 enzyme, a major "effector" caspase in hematopoiesis, in patients with "early stage" myelodysplasia, and 3) to evaluate the effect of caspase inhibition on the apoptotic phenotype and clonogenicity of hematopoietic progenitors in vitro in these patients.

MATERIALS AND METHODS

PATIENTS

Fifty-four patients with myelodysplastic syndromes, including 30 with "early stage" myelodysplasia and 24 with "late stage" myelodysplasia were studied. Study of apoptosis: TUNEL assay performed on bone marrow smears and/or quantification of annexin V positive bone marrow mononuclear cells by flow cytometric analysis. Caspacse-3/CPP32 activity: Quantitative measurement of caspase-3/CPP32 activity on total bone marrow mononuclear cells using a fluorogenic substrate. Effect of the caspase-inhibitor Z-VAD-FMK: 1) on the apoptotic phenotype of total bone marrow mononuclear cells and 2) on the clonogenicity of hematopoietic progenitor cells.

RESULTS

The group of 30 patients with "early stage" myelodysplasia had statistically increased apoptosis compared to the group of 24 patients with "late stage" myelodysplasia (44.1% +/- 4.8 vs 21.8% +/- 3.6; p = 0.02) using the TDT-mediated dUTP nick-end labeling (TUNEL) assay. In the group of patients with RAEB, those with MDS(RAEB<10) had excessive apoptosis compared to those with MDS(RAEB>10) (44.0% +/- 3.5% vs 29.5% +/- 3.6%;p = 0.042) The median caspase-3 activity in 20 "early stage" myelodysplasia patients was 19,000 U (range 3,460-41,000) and significantly increased compared to normal individuals (4,256 U, range 3,200-5,200; p = 0.032) Bone marrow mononuclear cells from 12 "early stage" MDS patients (including 11 from the 20 studied for caspase-3 activity) were incubated with or without the broad-spectrum caspase inhibitor Z-VAD-FMK. In 4 of 9 evaluable patients (44.4%) with excessive apoptosis, the number of annexin V positive cells decreased in a dose-dependent manner in the presence of Z-VAD-FMK. However, in none of these patients was caspase inhibition with Z-VAD-FMK able to enhance colony formation in vitro.

CONCLUSION

These results confirm that a major characteristic of patients with "early stage" myelodysplasia is increased apoptosis. The results also indicate that excessive apoptosis in these patients is accompanied by increased caspase-3/CPP32 activity. However, caspase inhibition with the broad-spectrum inhibitor Z-VAD-FMK cannot improve hematopoiesis in this group of patients, even when apoptosis is attenuated.

Synthesis and cytotoxic evaluation of a series of gamma-substituted gamma-aryloxymethyl-alpha-methylene-gamma-butyrolactones against cancer cells

PURPOSE

The main objective of this investigation was to explore the cytotoxic structure-activity relationships of gamma-substituted gamma-aryloxymethyl-alpha-methylene-gamma-butyrolactones against cancer cells.

METHODS

The target compounds were synthesized in two steps commencing with aryl-OH which was treated with a bromomethyl ketone followed by the Reformatsky-type condensation.

RESULTS

Seven types of alpha-methylene-gamma-butyrolactones were evaluated in vitro against 60 human cancer cell lines derived from nine cancer cell types. The average values of log GI50 indicated that for the aryl portion, potencies of these alpha-methylene-gamma-butyrolactones are in a decreasing order of quinolin-2(1H)-one (or 2-hydroxyquinoline, 21, -5.89) > quinoline (19, -5.79) > 2-methylquinoline (20, -5.69) >8-hydroxyquinoline (17,-5.64) > 2-naphthalene (16, -5.59) > benzene (15, -4.90). The same order was obtained for both log TGI and log LC50. However, for the gamma-substituent, the potencies are in a decreasing order of biphenyl (16f-21f) > phenyl and 4-substituted phenyl (16b-e-21b-e) > methyl (16a-21a).

CONCLUSIONS

Unlike cardiovascular activities of alpha-methylene-gamma-butyrolactones in which a gamma-methyl substituent is necessary for vasorelaxing effect while a phenyl or a halogen-substituted phenyl is prefer for the antiplatelet activities, a gamma-biphenyl substituent proved to be the best for their cytotoxicities against various cancer cell lines tested.

Predicting the vertebral inclination of the lumbar spine

The objectives of this study were to examine the accuracy of the external stick marker method in the assessment of sagittal plane vertebral inclination (L1 to S1) during trunk flexion and to develop regression equations for predicting vertebral inclinations of the lumbar spine. Lateral radiographs of 16 subjects were taken from the upright position to a trunk flexion of 90 degrees, in 30 degrees increments. Each subject was radiographed in only three of the four torso positions to minimize the risks of radiation. The inclinations of the vertebrae in the radiographic view were then obtained. The results show that the stick marker technique is a poor protocol for measuring vertebral inclination of the lumbar spine. During trunk flexion, the upper vertebrae incline linearly and the lower vertebrae incline exponentially. This is verified by the finding that the best-fit equations selected by regression techniques were linear at the upper vertebrae (L1, L2 and L3) and non-linear at the lower ones (L4, L5 and S1), with a mean R2 value of 0.964. The inherent difference in motion pattern between the vertebrae of the lumbar spine during trunk flexion is discussed for clinical and ergonomic purposes.