[Induction of skin immune tolerance of mouse to rat xenogeneic transplantation]

OBJECTIVE

To explore a moderate and effective project which will be clinically suitable to induce donor-specific tolerance across xenogeneic barriers.

METHODS

4 x 10(7) Lewis rat bone marrow cells were infused to 300 rad total body irradiated (TBI) C57BL/6 (B6) mice, combined with intraperitoneal administration of cyclophosphamide (CTX) and intravenous injection of anti-mouse CD4 monoclonal antibody. Recipient B6 mice were characterized for the tolerance status with donor Lewis rat skin graft, mixed lymphocyte reaction (MLR), and delayed-type hypersensitivity (DTH) assays after 30 days. Adoptive transfer and the effect of IL-2 on MLR were detected to further explore the tolerance mechanism.

RESULTS

Survival time of donor rat skin grafts was specifically prolonged in the tolerant B6 mice. The results of MLR and DTH assays showed donor-specific hyporeactivity, while the tolerant B6 mice were still immunocompetent to MHC-disparate third party BALB/c mouse or DA rat stimulator cells.

CONCLUSIONS

A reliable xenogeneic transplantation tolerance of mouse to rat was achieved by this project of tolerance induction. The result of in vitro and in vivo adoptive transfer of spleen cells from tolerant B6 mice demonstrated that the suppressor cells were unlikely to exert effect in the tolerance. The inhibition of specific MLR could be reversed by adding IL-2, indicating that clonal anergy instead of clonal deletion is responsible for the tolerant maintenance.

Dielectric response of a polarizable system with quenched disorder

We present and analyze a lattice model of a disordered dielectric material. In the model, the local polarizability is a quenched statistical variable. Using a reaction field approach, the dielectric response of the model can be cast in terms of an effective Hamiltonian for a finite primary system coupled to its effective average medium determined self-consistently. A real space renormalization group analysis is carried out by recursively increasing the size of the primary system. The analysis determines the length scale dependence of the local polarizability distribution. For the case of isotropic disorder considered in this paper, we show that the width of the distribution decays algebraically with increasing lattice spacing. We also compute the distribution of solvation and reorganization energies pertinent to kinetics of electron transfer.

[Trabeculectomy combined with phacoemulsification for treatment of glaucoma complicated with cataract]

OBJECTIVE

To evaluate the effectiveness of small-incision triple procedure, including phacoemulsification, posterior chamber intraocular lens implantation and trabeculectomy, in patients with coexisting glaucoma and cataract.

METHODS

Twenty patients (26 eyes) with coexisting glaucoma and cataract underwent 3.5 mm-incision triple procedure. The mean follow-up was 16.1 months (3 - 41 months).

RESULTS

The mean preoperative intraocular pressure (IOP) was (23.01 +/- 2.63) mm Hg (1 mm Hg = 0.133 kPa) which decreased to a mean postoperative IOP of (13.93 +/- 1.85) mm Hg (P < 0. 001). Seventeen (65%) of 26 eyes had a best-corrected visual acuity of >or= 0.6 at the last follow-up (range, 0.05 - 1.0). The mean magnitude of astigmatism was 0.81 D (range, 0 - 3.00 D), 4 eyes had no astigmatism. Although 2 eyes used antiglaucoma medications shortly after the surgery, no eyes used any medications at the last follow-up. The early postoperative complications included corneal edema in 5 eyes (19%) and shallow anterior chamber in 3 eyes (12%). The late complication was mainly the after cataract in 6 eyes (23%).

CONCLUSIONS

The small-incision triple procedure appears effective for treating selected patients with coexisting cataract and glaucoma, improving the valid visual acuity rapidly, reducing intraocular pressure with less medications and having less postoperative complications.

[The clinical study of tongue flaps repairing after resecting pharyngeal neoplasm and laryngeal neoplasm]

OBJECTIVE

To study the repair methods of the defect after resecting pharyngeal neoplasm and laryngeal neoplasm.

METHODS

Four kinds of tongue flap, such as 1/3 tongue flap, 1/2 tongue base flap, tongue base flap and transverse tongue flap were devised and applied in 15 patients with pharyngeal neoplasm and laryngeal neoplasm.

RESULTS

These tongue flaps were alive in all patients. The wound of 13 patients healed in I stage. Two patients dehiscenced because of infection and healed after treatment. All the patients deglutited well. One-year, 3-year, disease-free survive rate were 92.9% (13/14), 72.7% (8/11) respectively.

CONCLUSION

Tongue flaps are obtained easily, with enough blood flow, adapted to pharyngeal environment, easily alive and low complication in repairing the pharyngeal defect. We think that these tongue flaps should be applied in clinic.

Polarizability fluctuations in dielectric materials with quenched disorder

We study a model of dielectric response for spatially disordered materials. In this model the local polarizability alpha(r) is a quenched random variable. From a one-loop level renormalization-group analysis, we predict that with increasing length scale L, the dimensionless fluctuation strength alpha;sigma, where 1/alpha; and sigma(2) are the average and the variance of the distribution for 1/alpha(r), decays as 1/L(2) universally at large length scales. The interplay of the random polarizability and the long-range dipole-dipole interaction is discussed.

[A review on the eco-physiological study of poplars in oasis and its prospect]

Poplar is the main component species in shelter forest subsystem, which forms a special kind of ecosystem in oasis with particular structure and function. Based on the studies on the ecophysiological characteristics of poplars in the Cele oasis, a preliminary comment was given on the experimental methods used at home and abroad, aim ed to facilitate the further studies on the characteristics of ecophysiology of poplars in the oasis. In order to sustain the oasis ecosystem management, the theoretical bases were also discussed on the optimization of shelter-forest structure and the selection of proper tree species.

Negative ion electrospray of bromo- and chloroacetic acids and an evaluation of exact mass measurements with a bench-top time-of-flight mass spectrometer

The negative ion electrospray mass spectra of six bromo- and chloroacetic acids were measured using two different electrospray interfaces and single quadrupole and bench-top time-of-flight mass spectrometers. With each acid at 50 microg/mL in aqueous methanol at pH 10, the anions observed included deprotonated molecules, adducts, and fragment ions. With each acid at 100 ng/mL in aqueous acetonitrile at pH 10, mainly deprotonated molecules are observed. The exact m/z measuring capability of the time-of-flight mass spectrometer was evaluated to assess the potential for the determination of the individual acids in mixtures without an on-line separation. Mean measurement errors were nearly always less than +/- 9 ppm and the majority were less than +/- 5 ppm. Potential interferences by substances having similar exact masses and the ability to form anions in aqueous solutions were evaluated. The estimated detection limits of the five regulated haloacetic acids in drinking water, without a sample preconcentration step, are in the range of 24-86 ng/mL, which is within about a factor of 10 of the levels required for routine monitoring of the acids. Actual drinking water samples were not analyzed pending the development of slightly more sensitive techniques and quantitative analytical procedures.

Flow cytometry-based biosensor for detection of multivalent proteins

Microsphere-based flow cytometric detection of cholera toxin (CT) through distance-dependent fluorescence resonant energy transfer (FRET) has been developed. Simultaneous double-fluorescence changes induced by multivalent interactions between CT and fluorophore (both fluorescence donor and acceptor)-labeled ganglioside GM1 on a biomimetic membrane surface (supported bilayers of phospholipids) can be measured by a commercial flow cytometer, providing a convenient and sensitive detection method for CT. The flow cytometry-based biosensor is capable of detecting less than 10 pM CT within 30 min. The signal generation strategy coupled with flow cytometry also provides a convenient method for kinetic studies of multivalent interactions. The surface density and the ratio of donor/acceptor-labeled GM1 on the surfaces of phospholipid bilayers are optimized to achieve high sensitivity.

Quantitation of Chlamydia trachomatis 16S rRNA using NASBA amplification and a bioluminescent microtiter plate assay

We developed a nucleic acid sequence based amplification (NASBA) assay which employs the recombinant photoprotein Aequorin in a microtiter plate format for detection and quantitation of C. trachomatis that may be useful in large scale epidemiological studies aimed at improving our understanding of factors affecting transmission of this sexually transmitted pathogen. The conditions for NASBA amplification of the16S rRNA target were optimized (90 mM KCl, 12 mM MgCl(2), 0.2 microM P1 and P2 primers), amplified RNA was captured by a biotin-labelled capture probe immobilized onto streptavidin coated microtiter plates and detected with an FITC-labelled oligonucleotide probe and Aequorin-anti-FITC antibody conjugate. The analytical sensitivity of NASBA was 1,000 in vitro generated RNA transcripts and 1.6 IFU of C. trachomatis. The sensitivity of NASBA using the bioluminescent assay was 10 fold higher than Northern blotting. Time course amplification experiments performed with 10 fold serial dilutions of target established that amplification was linear at 75 min and extended over a range of five log units of input RNA copy number. Linear regression analysis confirmed a linear fit for the data with r(2) = 0.959 (p < 0.004). A double log plot of RLU signal versus copy number was linear; analysis of residuals from a series of runs tests confirmed a fit with a linear model (number of runs = 3, p = 0.5 where p < 0.05 indicates statistical deviation from a linear model). NASBA amplification coupled with bioluminescent detection in a microtiter plate format should provide a useful tool for quantitation of C. trachomatis in clinical specimens for use in epidemiological studies.

[Adjustable interatrial communication in management of severe congenital heart disease]

OBJECTIVE

To assess the use of adjustable interatrial communication in patient with severe congenital heart disease undergoing open heart surgery.

METHODS

From February 1998 to June 1999, 13 patients with severe and complex congenital heart disease underwent open heart surgery. Seven patients underwent total cavopulmonary connection, five patients repair of Ebstein's anomaly, and one patient right atrial-pulmonary connection. Adjustable interatrial communication was made in all patients. Four patients had the communication closed at the time of operation, 4 patients had the communication opened at the time of operation, and 5 patients had the communication adjusted and closed postoperatively.

RESULTS

All patients had a smooth postoperative process. There were no postoperative death and no severe postoperative complications.

CONCLUSION

Adjustable interatrial communication for the patients undergoing modified Fontan procedure or correction of Ebstein's anomaly may be advantageous.

[The effect of fluoride-arsenic exposure on the lipid peroxidation and antioxidation of the offspring of rats]

OBJECTIVE

To provide information on the effects of the offspring of rats exposed to fluoride-arsenic.

METHODS

The levels of lipid peroxidation and the abilities of antioxidation were determined in the blood of the rats and their offsprings under two generations-one nest reproductive test.

RESULTS

The activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the blood decreased with the increase of exposure dose. For example, the activity of SOD, was 14.56, 13.74, 11.89 and 11.21 micromol x min(-1) x mg Hb(-1) in different dose groups of F(2), respectively. In contrast, the concentration of lipid peroxides (LPO) increased. Eight weeks after exposure, the activities of SOD and GSH-Px increased, the activity of SOD was 13.97, 13.55, 13.47 and 12.76 micromol x min(-1) x mg Hb(-1), respectively, and the concentration of LPO returned to normal level.

CONCLUSION

Fluoride-arsenic exposure can cause oxidative damage of the rat's offspring.

[Clinical observation on effect of changmaishu in treating patients of coronary heart disease complicated with hyperviscosity]

OBJECTIVE

To explore the therapeutic effect and mechanism of Changmaishu (CMS) in treating coronary heart disease (CHD).

METHODS

Eighty patients with CHD complicated with hyperviscosity were treated with CMS for a period of 30 days as the CMS group, and the 40 patients treated with Salvia injection and Di'ao Xinxuekang were taken as the control group. The therapeutic efficacy and effect of treatment on plasma lipid peroxide (LPO) content, superoxide dismutase (SOD) activity, blood lipids, hemorrheologic indexes were observed.

RESULTS

The CMS group was better in clinical total effective rate, ECG improvement and concomitant symptoms relieved than those in the control group (P < 0.05 or P < 0.01). Markedly improvement of laboratory findings occurred in both groups (P < 0.05 or P < 0.01), but the changes of some parameters, such as LPO, SOD, total cholesterol, low-shear blood viscosity in the CMS group were more significant than those in the control group (P < 0.05).

CONCLUSION

CMS could reduce the blood hyperviscosity, increase antioxidative energy and improve symptoms of CHD effectively.

Acute effects of light on body temperature and activity in Syrian hamsters: influence of circadian phase

Light exposure at night causes an acute increase in human body temperature, which normally falls during the night. This change is largely attributable to the suppression by light of the nocturnal rise in melatonin levels. Little is known, however, about the effects of light on body temperature in nocturnally active mammals in which the nightly peak in melatonin secretion coincides with the circadian phase of elevated, rather than decreased, body temperature. We investigated the effects of a 1-h exposure to light on body temperature and activity of Syrian hamsters, Mesocricetus auratus, at two phases during the night and at two phases during the projected day. Brain or abdominal temperature was recorded continuously using implanted radio transmitters while locomotor activity was monitored simultaneously using a passive infrared movement detector. Responses to light exposure were strongly circadian phase dependent; light during the night caused elevations in both brain and core body temperature, whereas light during the projected day did not. Temperature increases at night could not be attributed solely to activity increases at the onset of light pulses, indicating a contribution from nonbehavioral mechanisms of thermogenesis. These results provide the first evidence for circadian modulation of acute temperature responses to light in a nocturnal mammal.

[Apoptosis of endothelial cells in alteration of microvascular permeability in lung during sepsis]

OBJECTIVE

To investigate the apoptosis of endothelial cells in the alteration of microvascular permeability in lung during sepsis.

METHODS

Twenty-four male NIH mice were subjected to cecal ligation and puncture (CLP) or sham operation (SO). The microvascular endothelial cells of the lungs were harvested at 3 hours and 12 hours after operation. The apoptosis of endothelial cells (VIII factor related antigen positive cells) in the lungs was determined by 2-color flow cytometry (FITC-labeled VIII factor related antigen and PI) and Apop Tag) in situ apoptosis detection kit in situ. The apoptosis related gene (bcl-2) was detected by RT-PCR. The microvascular permeability in lung tissue was also examined.

RESULTS

The apoptosis of microvascular endothelial cells was increased significantly at 12 hours after CLP (5.03 +/- 0.92 vs. 3.48 +/- 1.21, P < 0.05). The increased apoptosis was paralleled with the decrease in bcl-2 gene expression. The microvascular permeability in lung tissue was slightly increased at 3 hours after CLP, but significantly increased at 12 hours after CLP (0.106 +/- 0.008 vs 0.047 +/- 0.003, P < 0.01).

CONCLUSIONS

Apoptosis in microvascular endothelial cells seems to be an important reason for the alteration of microvascular permeability.

[Pathogenic microbes of biliary infection and their resistance to antibiotics]

OBJECTIVE

To understand the change of the main pathogenic microbes of biliary infection and their resistance rates to 12 antibiotics so as to instruct rational application of antibiotics clinically.

METHODS

All isolates were identified by analytic products incorporation (API) bioMerieux. The susceptibility of antibiotics to 470 pathogenic microbes was tested by minimal inhibition concentration (MIC).

RESULTS

There were 470 pathogenic microbes with positive biliary culture. The percentage of Escherichia coli, intestinal cocci and Klebsiella pneumoniae was 129 (27.4%), 82 (17.4%) and 76 (16.2%), respectively. In the resistance rates of the gram negative bacilli to 12 antibiotics, the lowest was 4.0% for imipenem followed by. 14.1% Ceftazidime and 16.9% amikacin. In the resistant rates of the gram positive cocci to 12 antibiotics, and had the lowest rate was 6.0% for vancomycin and 16.4% for imipenem.

CONCLUSIONS

The main pathogenic microbes of biliary infection were Escherichia coli, intestinal cocci and Klebsiella pneumoniae. Imipenem is the first used for biliary infection in dealing with multiresistant intestinal cocci.

The cyclooxygenase-2 inhibitor celecoxib induces apoptosis by blocking Akt activation in human prostate cancer cells independently of Bcl-2

This study investigates the apoptotic activity of the cyclooxygenase-2 (COX-2) inhibitor celecoxib in prostate carcinoma cells. COX-2 is constitutively expressed in androgen-responsive LNCaP and androgen-nonresponsive PC-3 cells. Exposure of these cells to celecoxib induces characteristic features of apoptosis, including morphological changes, DNA laddering, and caspase-3 activation, whereas piroxicam, a COX-1-specific inhibitor, displays no appreciable effect on either cancer cell line even after prolonged exposure. Moreover, the potency of celecoxib in apoptosis induction is significantly higher than that of other COX-2 inhibitors examined despite the observation that these inhibitors exhibit similar IC(50) in COX-2 inhibition. It is noteworthy that normal human prostate epithelial cells, expressing a marginally detectable level of COX-2, are insensitive to the induction of apoptosis by celecoxib. These data suggest a correlation between COX-2 expression and sensitivity to the apoptotic effect of the COX-2 inhibitor. In an effort to delineate the underlying mechanism, we examined the effect of celecoxib on the expression of Bcl-2 as well as the activation of the key anti-apoptotic kinase Akt. In contrast to an earlier report that attributed the apoptotic activity of NS398 in LNCaP cells to Bcl-2 down-regulation, we provide evidence that the induction of apoptosis by celecoxib in LNCaP and PC-3 cells is independent of Bcl-2. First, treatment with celecoxib does not alter the cellular Bcl-2 level in both cell lines. Second, enforced Bcl-2 expression in PC-3 cells does not confer protection against the induction of apoptosis by celecoxib. Our data show that celecoxib treatment blocks the phosphorylation of Akt. This correlation is supported by studies showing that overexpression of constitutively active Akt protects PC-3 cells from celecoxib-induced apoptosis. Nevertheless, how celecoxib down-regulates Akt is not clear because the drug does not adversely affect phosphoinositide 3-kinase activity in vivo and okadaic acid, a protein phosphatase 2A inhibitor, cannot rescue the inhibition. In summary, our data demonstrate that inhibition of Akt activation may play a crucial role in the induction of apoptosis by celecoxib.

[Cause and management of dislocated nuclear fragments during phacoemulsification]

OBJECTIVE

To investigate the cause and management of posteriorly dislocated lens nucleus in the vitreous cavity during phacoemulsification.

METHODS

The authors performed a retrospective study of 18 patients with dislocation of nuclear fragment into vitreous cavity during phacoemulsification at Tong Ren Hospital from August 1994 to January 1999.

RESULTS

4 cases with dislocated nuclei floated in the anterior vitreous were removed by a lens loop from limbal extensive incision. 2 cases with their dislocated nuclei less than 1/4 of the normal size were under follow-up for 3 - 4 years, and no complications were observed. The final outcome in 1 case with a dislocated nucleus half of its normal size was ocular atrophy as a result of phacoanaphylactic endophthalmitis. 11 cases underwent pars plana vitrectomy. In the operation the nuclei were floated anteriorly by injection of perfluoro-1, 3-dimethylcyclohexane, then they were removed by a lens loop through the limbus and in 2 cases they were fragmented by ultrasound. The main post-operative complication was corneal edema. The final visual acuities generally were improved in varying degrees in 1 month to 4 years of follow-up.

CONCLUSIONS

During phacoemulsification, the dislocation of a nucleus is liable to first occur in the peripheral sculpting stage, and secondly in central sculpting stage. A radial tear extending posteriorly from a discontinuous anterior capsulorrhexis is the major risk factor predisposing to posterior dislocation of the nucleus or nuclear fragment. During phacoemulsification, vitrectomy should be performed as soon as possible for a nucleus dislocated into middle or posterior vitreous cavity, and it is a safe and effective method for management of dislocated nucleus.

[The ultrastructure of human and mouse cataractous lens epithelial cell apoptosis]

OBJECTIVE

To observe the relation between human senile cataract, mouse congenital cataract and lens epithelial cell apoptosis.

METHODS

Transmission electron microscope was used to observe the apoptotic morphology of the lens epithelial cells in 4 cases with senile cataract and in 2 mice with congenital cataract. The comparisons were made between the cataractous and normal transparent lens epithelial cells in human being and mice.

RESULTS

The apoptotic cells were found in senile cataract and mouse congenital cataract lens epithelial cells, while in all control lens epithelial cells they were few.

CONCLUSION

Lens epithelial cells apoptosis is related to senile cataract and mouse congenital cataract formation.

[Study on the DNA gyrA gene mutation with resistance to fluoroquinolones in Staphylococcus aureus isolated from patients]

This study was aimed at the mechanism of resistance to fluoroquinolones in Staphylococcus aureus isolated from patients in Chengdu. The relationship between the point mutations in the gyrA genes and the resistance of 63 strains (57 fluoroquinone-resistant strains and 6 wild types) isolated clinically in Chengdu were investigated by a combination of restriction fragment length polymorphism analysis. The results revealed that there are 67.27%-92.5% of the fluoroquinolone-resistant strains against norfloxacin, fleroxacin, tosufloxacin, cipofloxacin, ofloxacin and sparfloxacin had a Hinf I site mutation in the gyrA genes, and most of such strains with such mutation in the gyrA genes showed high-level resistance. These indicate that Hinf site mutation in gyrA genes is the mainly cause of the resistance of fluoroquinolone-resistant strains of Staphylococcus aureus in Chengdu region.

[The treatment of stricture of larynx and trachea with Ni-Ti shape memory alloy stand]

OBJECTIVE

To evaluate the use of Ni-Ti shape memory alloy stand in the treatment of stricture of larynx and trachea.

METHODS

The clinical materials of 14 patients were analyzed. All patients had stricture of larynx and trachea and accepted the treatment with Ni-Ti shape memory alloy stand.

RESULTS

All patients breathed freely after the operation, and the trachea fistula was closed at the time of operation. The follow-up survey for these patients lasted for 2 to 12 months. None of the patients had signs of the stricture of the respiratory tract. The short-term effective rate was 100%.

CONCLUSION

Ni-Ti shape memory alloy stand can expand the stricture of larynx and trachea quickly and thus improve the breath effectively. It can be used as a routine method in the treatment of stricture of larynx and trachea.

Childhood-onset primary open angle glaucoma in a Canadian kindred: clinical and molecular genetic features

OBJECTIVE

To describe the clinical features and identify the molecular etiology of childhood-onset primary open angle glaucoma (POAG) in a Canadian kindred.

METHODS

Members of a Canadian Caucasian family with POAG were examined and DNA obtained. Single-strand conformation polymorphism analysis was performed using reported primers from exon 3 of the myocilin gene. A single-stranded conformation polymorphism was characterized by polymerase chain reaction-based sequencing.

RESULTS

Two affected half-sibs had onset of severe glaucoma at age 3 and 9. Their mother had lost vision in one eye from glaucoma by age 17. All three affected subjects had undergone bilateral glaucoma filtering surgery. Both fathers were unaffected. A single-stranded conformation polymorphism was identified in the mother and the two affected daughters and was absent in one father. A single base change from C-->T at nucleotide position 1109 was identified in the affected members of the family by direct sequencing. This mutation, which causes a nonconservative amino acid change (Pro370Leu), was not found on 192 normal chromosomes from Caucasian individuals.

CONCLUSION

We report a Canadian family with childhood-onset, severe POAG due to a mutation in the myocilin gene.

Integrated optical biosensor for detection of multivalent proteins

We have developed a simple, highly sensitive and specific optical waveguide sensor for the detection of multivalent proteins. The optical biosensor is based on optically tagged glycolipid receptors embedded within a fluid phospholipid bilayer membrane formed upon the surface of a planar optical waveguide. Binding of multivalent cholera toxin triggers a fluorescence resonance energy transfer that results in a two-color optical change that is monitored by measurement of emitted luminescence above the waveguide surface. The sensor approach is highly sensitive and specific and requires no additional reagents and washing steps. Demonstration of protein-receptor recognition by use of planar optical waveguides provides a path forward for the development of fieldable miniaturized biosensor arrays.