[The treatment to esophagus stricture with Ni-Ti shape memory alloy stand(with the report of 19 clinical cases)]

OBJECTIVE

To discuss the use of Ni-Ti shape memory alloy stand in treating the stricture of esophagus.

METHOD

After finding the stricture part of esophagus under X-ray, the metal guide string was put through the esophagoscope. Dilatation of esophagus was performed firstly. Then the inserting instrument, which has the Ni-Ti shape memory alloy stand inside, was put through the stricture part along the metal guide string and the stand which can return to its original shape automatically was released. Barium meal examination of esophagus was performed after the operation to determine the site of the stand and to realize the smooth degree of esophagus.

RESULT

All 19 patients got a successful operation at one time. They swallowed freely after the operation. The effective rate was 100%.

CONCLUSION

Ni-Ti shape memory alloy stand can dilate the stricture of esophagus quickly, improve swallowing function obviously. The operation can be easily performed. The therapeutic effectiveness is reliable, and there is no serious complication. This can be used as a routine method in treating the stricture of esophagus.

[Prevalence of blindness among adults aged 50 years or above in Shunyi county of Beijing]

OBJECTIVE

To estimate the prevalence of blindness among older adults aged >or= 50 years in Shunyi county of Beijing, China.

METHODS

Cluster sampling was used in randomly selecting individuals aged >or= 50 years in 28 villages in Shunyi county in fall, 1996. The survey was preceded by a pilot study where operational methods were refined and quality assurance evaluation was carried out.

RESULTS

5,555 individuals were enumerated. The response rate was 91.5%. In this population, the prevalence of blindness was 1.7% defined as pinhole visual acuity < 0.05 in both eyes; or 2.8% were blind, defined as presenting visual acuity < 6/60 in both eyes. Blindness was associated with older age and female gender. The principal cause of blindness in eyes was cataract.

CONCLUSIONS

The prevalence of blindness was decreased 35.8% after ten year active eye-care program in the survey area. However, cataract blindness continues as a significant problem among elderly, especially females, in this population sample of rural area.

Studies of hydroxypropyl methylcellulose donut-shaped tablets

Simple uncoated compressed tablets with a central hole (donut shape) or multihole tablets were prepared. Theophylline and diltiazem hydrochloride were used as model drugs to investigate in vitro drug release from donut-shaped tablets. The effects of hole size, the number of holes, drug solubility, and stirring rate on release kinetics were investigated. As for the donut-shaped tablets, the duration of zero-order drug release could be up to 80-90%. When the hole size was increased, the release rate increased, and the duration of linear drug release was longer. The durations of linear drug release of two-hole and three-hole tablets were longer than that of the single-hole tablets. As the drug solubility increased, the duration of linear drug release was shortened. However, three stirring rates (50 rpm, 100 rpm, 150 rpm) had little effect on the drug release.

[Neurilemmoma of the nasal cavity and paranasal sinuses (report of 12 cases)]

OBJECTIVE

To further understand the neurilemmoma of nose.

METHOD

12 cases of neurilemmomas of the nasal cavity and paranasal sinuses were treated successfully by operation, 2 cases of malignant change lesions were treated by extensive resection and radiation.

RESULT

11 in 12 cases were followed up. 9 cases were cured and no any serious complications, 2 cases of malignant tumor were died.

CONCLUSION

Early stage diagnosis is important. CT scan should be made as essential examination, complete surgical resection is the choice of treatment for primary lesions; malignant change lesions should be treated by combined operation with radiation.

[Study on the induction of xenogeneic tolerance of rat to mouse bone marrow transplantation]

OBJECTIVE

To establish an effective protocol for potential clinical usage in inducing donor-specific tolerance across xenogeneic barriers.

METHODS

C57BL/6 (B6) mice were conditioned with 5 Gy sublethal total body irradiation (TBI), followed by infusion of 4 x 10(7) Lewis rat bone marrow cells on day 0, then were intraperitonially administered 150 mg/kg cyclophosphamide (CP) on day 2. Recipients were characterized for engraftment with xenogeneic bone marrow cells by using fluorescence activated cell sorter (FACS) to determine the percentage of rat origin cells in the peripheral blood lymphocytes(PBL), splenic and thymic lymphoid cells on day 30, 60 and 90. Mixed lymphocyte reaction (MLR) and delayed type hypersensitivity (DTH) assay were performed on day 30 to examine the tolerance status.

RESULTS

Rat lymphoid chimeras were reliable present in the tolerant B6 mice for more than 3 months. B6 recipients were specifically tolerant to host xenoantigens in MLR and DTH assays, but were still immunocompetent to MHC-disparate third party BALB/c mouse or DA rat stimulator cells.

CONCLUSION

A durable rat to mouse xenogeneic bone marrow transplantation tolerance was achieved in this modal.

Changes of superoxide dismutase, glutathione perioxidase and lipid peroxides in the brain of mice preconditioned by hypoxia

We have developed an animal model of hypoxic preconditioning and assumed that oxygen radicals and their endogenous scavenging enzymes may play an important role in the preconditioning. To test this hypothesis, activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and the content of lipid peroxides (LPO) were measured during the preconditioning. Compared with unpreconditioned control animals, in animals exposed to hypoxia only once, the activities of SOD and GSH-Px in whole brain were found to be significantly decreased while the LPO content in the hippocampus significantly increased. However, those in animals exposed to 4 runs of hypoxia tended to return to control levels and were lower than those in animals exposed to 1 and 2 runs of hypoxia. Our results indicate that the oxygen radicals and their specific scavenging enzymes seem to be involved in the development of tolerance to hypoxia.

Immunologic response to recombinant hirudin in HIT type II patients during long-term treatment

We prospectively investigated 27 patients with heparin-induced thrombocytopenia (HIT) type II who were subsequently treated with r-hirudin. Patients with venous or arterial thromboembolism were treated with activated partial thromboplastin time (aPTT)-controlled intravenous r-hirudin (n = 19; mean 19.3 d) followed by subcutaneous r-hirudin (n = 6; mean 22.5 d) and oral anticoagulation. Patients without thromboembolism were treated with subcutaneous r-hirudin (n = 8; mean 25.9 d). Four patients were readmitted to subcutaneous r-hirudin for a mean duration of 32 d. The incidence of r-hirudin antibodies was 84% for intravenously treated patients and 50% in subcutaneously treated patients. The patients (n = 27) showed a 74% overall incidence of r-hirudin antibodies, mainly of the IgG-subclass, without seroconversion before day 6 and after day 32 of r-hirudin treatment or during r-hirudin treatment. None of the patients showed onset or recurrence of venous or arterial thromboembolism, systemic allergic reactions or IgE-antibody development. During intravenous and subcutaneous administration of r-hirudin the aPTT and the ecarin clotting time was increased in the antibody-positive patients compared to antibody-negative patients. Therefore we assume that r-hirudin antibodies may reduce r-hirudin metabolism.

Direct, ultrasensitive, and selective optical detection of protein toxins using multivalent interactions

Three highly sensitive, selective, and reagent-free optical signal transduction methods for detection of polyvalent proteins have been developed by directly coupling distance-dependent fluorescence self-quenching and/or resonant-energy transfer to the protein-receptor binding events. The ganglioside GM1, as the recognition unit for cholera toxin (CT), was covalently labeled with fluorophores and then incorporated into a biomimetic membrane surface. The presence of CT with five binding sites for GM1 causes dramatic change for the fluorescence of the labeled GM1. (1) In the scheme using fluorescence self-quenching as a signal-transduction mechanism, the fluorescence intensity drops significantly as a result of aggregation of the fluorophore-labeled GM1 on a biomimetic surface. (2) By labeling GM1 with a fluorescence energy transfer pair, aggregation of the labeled GM1 results in a decrease in donor fluorescence and an increase in acceptor fluorescence, providing a unique signature for selective protein-receptor binding. (3) In the third scheme, using the biomimetic surface as part of signal transduction and combining both fluorescence self-quenching and energy-transfer mechanisms to enhance the signal transduction, a signal amplification was achieved. The detection systems can reliably detect less than 0.05 nM CT with fast response (less than 5 min). This approach can easily be adapted to any biosensor scheme that relies on multiple receptors or co-receptors. The methods can also be applied to investigate the kinetics and thermodynamics of the multivalent interactions.

Advanced glycation in D-galactose induced mouse aging model

It was first reported in China that injection of a low dose of D-galactose into mice could induce changes which resembled accelerated aging. The aging model shows neurological impairment, decreased activity of anti-oxidant enzymes, and poor immune responses. However, the underlining mechanism remains largely unknown. D-galactose is a reducing sugar that can form advanced glycation endproducts (AGE) in vivo. To investigate the role of AGE in this aging model, a group of 5-month-old C57 mice were injected daily with D-galactose, D-galactose modified AGE-lysine (AGE-lysine), L-glucose, L-lysine, or control buffer for 8 weeks. Two additional groups were treated with the AGE formation inhibitor, aminoguanidine. The results show that D-galactose, L-glucose, and AGE-lysine treated mice had a significant increase in serum AGE levels, memory latency time and error rate, and skin hydroxyproline content. Similar to aged controls, these mice also had a significant decrease in motor activity, lymphocyte mitogenesis, interleukin-2 (IL-2) production, and superoxide dismutase (SOD) enzyme activity. The aminoguanidine treated D-galactose-injected mice, however, showed no significant changes in these parameters in comparison with young controls. These data indicate that D-galactose and L-glucose form AGEs in vivo and that elevated AGEs may accelerate the aging process. The fact that both D-galactose and AGE treated mice resemble aged mice suggests that advanced glycation, at least partially, accounts for the mechanism of this aging model.

[Regulation of adherence to serum-coated hydroxyapatite by Streptococcus sanguis]

OBJECTIVE

To investigate the effects of pH and calcium iron on adhesion of Streptococcus sanguis to serum-coated hydroxyapatite.

METHODS

The adhesion model in vitro established by Clark W. B. in 1977 was used to quantify adsorptive cells through [3H] thymidine labelling.

RESULTS

The cpm values between different pH groups showed significant differences. Also, there were significant differences of cpm values between calcium groups and control group.

CONCLUSION

Either pH or calcium iron has obvious effect on adherence of Stroptococcus sanguis to serum-coated hydroxyapatite. The findings suggest that regulating pH and concentration of calcium iron can help to change colonization on teeth surfaces by Streptococcus sanguis in periodontal circumstance.

Antigen changes of monoclonal antibody MSH27 in process of post-testicular maturation (in mice)

An anti-mouse spermatozoon monoclonal antibody, MSH27, as well as its purified antigen, can block sperm-egg membrane fusion. As a candidate protein for sperm-egg membrane fusion, the sperm antigen was investigated in the process of post-testicular maturation (PTM). The molecule was produced in testes and located on the plasma membrane of the postacrosomal area of the spermatozoon. However, the epitope recognized by the MSH27 (MSH27Ep) was not exposed until the occurrence of the acrosome reaction. In the process of fertilization, spermatozoa must complete the acrosome reaction before penetrating across the zona pellucidas (ZPs) to approach the plasma membrane of eggs. The effects of the acrosome reaction and penetration of the ZP on the exposure of the MSH27Ep were also studied. It was shown that the percentage of the spermatozoa with the MSH27Ep exposed increased followed with their mature status in PTM. In fact, it had a linear correlativity with the rate of the acrosome reaction. After spermatozoa had passed ZPs, almost all of them became the MSH27-positive in immuno-staining compared with only a part of the spermatozoa after the acrosome reaction. In a word, the exposure of MSH27Ep was coincident with attaining the ability to penetrate the plasma membrane of eggs.

Immunolocation of antisperm monoclonal antibody 6B10 and corresponding antigen

An antisperm monoclonal antibody 6B10 was produced by hybridoma technique of the isotype IgG. The monoclonal antibody was purified by means of ammonium sulfate precipitation and protein A-Sepharose C1-4B affinity chromatography. SDS polyacrylamide gel electrophoresis was used to evaluate the purity of the antibody. Evaluation of the sperm acrosomal status was determined by chlortetracycline (CTC) staining. It was found that monoclonal antibody 6B10 can inhibit the sperm acrosome reaction induced by progesterone. The corresponding antigen recognized by monoclonal antibody 6B10 was located on the plasma membrane of the sperm acrosome by indirect immunofluorescent microscopy and immunoelectronmicroscopy. Sperm protein was extracted by 1% Triton X-100. The molecular weight of the antigen is 50 ku, detected by Western blot. The antigen is a key protein in the sperm acrosome reaction and may be the receptor of progesterone on the sperm acrosome. It may either be developed as a candidate contraceptive vaccine or be used as a tool in pest/rodent management.

[The application of chopping method for phacoemulsification of hard nucleus cataract]

OBJECTIVE

The study was designed to investigate the application of chopping method for phacoemulsification of hard nucleus cataract.

METHODS

Modified stop and chop technique was used to emulsify the hard nucleus cataract. The degree of nuclear hardness in 80 eyes was grade IV.

RESULTS

Postoperatively, the visual acuity with correction was >or= 0.9 in 76.25% at 3 months. There were mild corneal edema in 8 cases, moderate corneal edema in 2 cases and posterior capsular rupture in 1 case.

CONCLUSION

The modified stop and chop technique enables the tenacious nuclear plate to rupture easily, thus the stress on the zonules and capsule can be decreased, and in the mean time the technique needs less phaco energy and time.

[Effects of cooking oil fume condensate on cellular immunity and immunosurveillance in mice]

Rapeseed oil fume, soyabean oil fume and salad oil fume condensate were injected respectively to female Kunming mice. The results showed that, compared to control group, in mice exposed to low level of rapeseed oil fume condensate, the delayed hypersensitivity responses were inhibited, while in mice exposed to high level of that, the delayed hypersensitivity responses and the NK cells activity were inhibited. In mice exposed to high level of soyabean oil fume condensate the delayed hypersensitivity responses, the NK cells activity and CaM activity were inhibited. The results of these parameters were all statistically significantly different from those in control mice. In mice exposed to low level of salad oil fume condensation, the delayed hypersensitivity responses and the NK cells activity were significantly inhibited. The results indicated that cooking oil fume could affect immune system of animals.

Mitogen-activated protein kinase is involved in the degradation of p53 protein in the bryostatin-1-induced differentiation of the acute promyelocytic leukemia NB4 cell line

Overexpression of mutant p53 has been reported to promote tumorigenicity in several cancers. However, despite its potential importance, the signals regulating mutant p53 protein expression are not known. Here we show that a form of p53 that is incapable of binding DNA is overexpressed in the acute promyelocytic leukemia NB4 cell line. Our results demonstrate that treatment of NB4 cells with bryostatin-1, which induces differentiation in this cell line, leads to hyperphosphorylation of this DNA binding-impaired form of p53 via mitogen-activated protein kinase. After this phosphorylation, the p53 protein is degraded by the ubiquitin/proteasome pathway. Furthermore, we show that inhibition of p53 hyperphosphorylation blocks p53 protein degradation and cell differentiation. In addition, inhibition of the ubiquitin/proteasome pathway also blocks p53 protein degradation and cell differentiation. These findings suggest a role for mitogen-activated protein kinase in the degradation of the DNA binding-impaired form of p53 protein and in the bryostatin-induced differentiation observed in this cell line. The implications of these results with respect to the functional significance of p53 phosphorylation and degradation in cell differentiation are discussed.

Rapid and genomic biological responses are mediated by different shapes of the agonist steroid hormone, 1alpha,25(OH)2vitamin D3

The hormone 1alpha,25(OH)2vitamin D3 (1,25-D) produces biological responses via both genomic and rapid mechanisms. The genomic responses are linked to a nuclear receptor, while the rapid responses are believed to utilize other signal transduction pathways that are likely linked to a putative cell membrane receptor for 1,25-D. The natural seco-steroid, 1,25-D, is capable of facile rotation about its 6,7 single carbon bond to permit generation of a continuum of potential ligand shapes extending from the 6-s-cis (6C) to the 6-s-trans (6T). To identify the shape of the conformer(s) that can serve as agonists for the genomic and rapid responses, we synthesized two families of analogs that were locked in either the 6T or 6C conformation. We found that 6T-locked analogs were inactive or significantly less active than 1,25-D in both rapid responses (transcaltachia or the rapid stimulation of intestinal Ca2+ absorption in perfused chick intestine, stimulation of whole cell chloride currents in osteoblastic ROS 17/2.8 cells, and stimulation of phosphorylation of mitogen-activated protein kinase in promyelocytic NB4 leukemic cells) and in genomic responses (induction of osteocalcin in human MG-63 osteoblastic cells). For genomic responses, the 6C-locked analogs bound poorly to the nuclear receptor and were much less potent than 1,25-D. In contrast, the 6C-locked analogs were potent agonists of the three rapid responses studied and had activities equivalent to 1,25-D. These results demonstrate that the signal transduction pathways that support rapid and genomic responses can discriminate between different shapes of the conformationally flexible 1,25-D.

Determination of heparin-induced IgG antibody by fluorescence-linked immunofiltration assay (FLIFA)

A fluorescence-linked immunofiltration assay (FLIFA) was developed for the determination of heparin-induced IgG in heparin-induced thrombocytopenia (HIT) type II patients. Protein A was immobilized on a nitrocellulose membrane to bind heparin-induced IgG of HIT type II patients. Fluorescein-5-isothiocynate (FITC)-heparin was added to platelet factor 4 present in normal serum to form the neo-antigen which was captured by heparin-induced IgG. The heparin-induced IgG was quantified by the relative fluorescence intensity (RFI) of bound FITC-heparin. Values were expressed as a RFI ratio (RFI patient / RFI normal) and were 1.965+/-0.413 in HIT type II patients (n = 36) and 1.064+/-0.162 in healthy controls (n = 50, p<0.0001). The intra- and inter-assay coefficients of variation were 4.9 and 10.4%, respectively. The heparin-induced IgG FLIFA will be useful in individual and epidemiological studies in patients during treatment with heparin. The FLIFA technique offers an alternative, rapid and sensitive methodological approach for studies on the interaction between antigen-antibody or ligand-receptor.

Determination of chlorinated acid herbicides and related compounds in water by capillary electrophoresis-electrospray negative ion mass spectrometry

Capillary electrophoresis electrospray negative ion mass spectrometry was investigated for the determination of chlorinated acid herbicides and several phenols in water. Sixteen analytes were separated as their anions in less than 40 min with a buffer consisting of 5 mM ammonium acetate in isopropanol-water (40:60, v/v) at pH 10. A sample stacking technique was used to provide lower detection limits and a fortified drinking water sample was made pH 10 and analyzed without further processing. Quantitative analyses with an internal standard gave recoveries in the 91-124% range and replicate measurements of a calibration standard gave relative standard deviations in the range of 3-10%.

Rhythmicity of torpor in a marsupial hibernator, the mountain pygmy-possum (Burramys parvus), under natural and laboratory conditions

Circadian rhythms have been observed in most mammals, but their importance and function remain controversial with respect to daily cycles during hibernation. We investigated the timing of arousals from and entries into hibernation for both free-living and captive mountain pygmy-possums (Burramys parvus). Under both natural and laboratory conditions most arousals and entries were entrained with the light-dark cycle. Entries occurred mainly during the night and arousals preferably around dusk, which coincides with the onset of the normal activity phase for the nocturnal pygmy-possums. This entrainment prevailed throughout the hibernation season although only the laboratory animals were constantly subjected to photoperiodic stimuli, whereas under natural conditions hibernacula are shielded from photic cues and diurnal temperature fluctuations. Nevertheless, possums left their hibernacula frequently throughout winter and were occasionally trapped close to the snow surface suggesting that during the periods of post-arousal normothermia they can be exposed to environmental stimuli. It thus appears that the synchronisation with the photocycle was governed by a temperature-compensated circadian clock which was reset periodically during short activity periods. For the mountain pygmy-possum, entrainment with the photocycle probably has two functions: 1. Entrainment ensures that foraging bouts during the hibernation season remain synchronised with the dark phase. 2. Information about the prevailing climatic conditions sampled during short activity periods enables them to time final spring emergence from hibernation when snow melt begins and ensures that the breeding season can commence as early as possible.

Seismic evidence for an inner core transition zone

Seismic waves that traverse Earth's inner core along north-south paths produce unusually broad pulse shapes at long periods (compared with waves along east-west paths) and reflections from below the inner core boundary at short periods. The observations provide compelling evidence for a seismic velocity discontinuity along north-south paths about 200 kilometers below the inner core boundary separating an isotropic upper inner core from an anisotropic lower inner core. The triplication associated with such a structure might be responsible for reported waveform complexity of short-period inner core arrivals along north-south paths and, if the depth of the boundary is laterally variable, their large travel-time variation.

The use of a chimera HIV-1/HIV-2 envelope protein for immunodiagnosis of HIV infection: its expression and purification in E. coli by use of a translation initiation site within HIV-1 env gene

A chimera HIV-1/HIV-2 envelope sequence composed of multiple conserved immunodominant epitopes of HIV-1 envelope protein (HIV-1 IIIB: env482-518 + env548-675) and the HIV-2 gp36 immunodominant epitope (env592-603), was constructed and directly over-expressed in E. coli by using a prokaryotic translation initiation sequence contained within the gene of HIV-1 envelope. The recombinant product was purified and applied in antibody-screening assay. The purified chimera antigen reacted with all the thirty-eight HIV-1 positive serum samples, the two HIV-2 serum samples, and had no cross-reaction with all the eighty-eight normal healthy serum sample. The results indicated that this recombinant chimera HIV-1/HIV-2 envelope protein could be useful for diagnostic purposes of HIV infection.

[Nasopharyngeal carcinoma and dermatomyositis (analysis of 12 cases)]

The onset relationship between dermatomyositis (DM) and malignant tumor, especially nasopharyngeal carcinoma (NPC), was approached. Approximately 90 cases of DM were admitted in the hospital. Among them 15 cases were complicated with malignant tumor of which 12 cases were complicated with NPC (account for 80% of DM with complicated carcinoma). In addition to treat these patients with prednisone and antibiotics, radiation therapy has been applied for NPC and metastasis in the neck. During the hospitalizations, one patient died, eleven patients' NPC was controlled, and the DM was completely resolved or improved. There is an obvious relationship between DM and carcinoma. DM may improve or even subside with good short term prognosis, as long as the carcinoma is controlled successfully.

[Phacoemulsification for mature or hypermature cataracts]

OBJECTIVE

To discuss how to choose the methods of capsularhexis and phacoemulsification in cases with mature or hypermature cataract.

METHODS

On fifty-nine mature or hypermature cataract patients, continuous circular capsularhexis or can-opener capsulotomy was performed. The nucleus was emulsified by the method of divide and conquer or phaco chop or rotatory carousel in the bag or at the plane of iris.

RESULTS

Continuous circular capsularhexis was successful in 51 cases, failed or shifted to can-opener in 8 cases. There were posterior capsular rupture in 1 cases, partial dehiscence of the zonule in 1 cases and iris bitten by the phaco tip in 1 cases. Postoperatively, there were mild corneal edema in 6 cases and iris posterior synechia in 1 cases.

CONCLUSION

Continuous circular capsularhexis is the key point to obtain a successful phacoemulsification for mature or hypermature cataract. Hydrodissection is not important before the phacoemulsification. Skillful phaco chop can reduce the surgical manipulation and the postoperative reaction.

Experimental study on the scavenging effects of ginsenosides on oxygen free radicals using model of heterotopic heart transplantation in rats

Oxygen-derived free radicals play an important role in myocardial injury associated ischemia and reperfusion. To investigate whether ginsenosides, as an additive agent of cardioplegic solution, can decrease toxicity of oxygen free radicals in myocardial injury, a heterotopic heart transplantation model in Wistar rats was employed. St. Thomas II cold cardioplegia containing ginsenosides 80 mg/l was used in the experimental group. St. Thomas II cold cardioplegia alone was used in the control group. After global ischemia for 60 minutes and reperfusion for 30 minutes of a transplanted heart, SOD activity in the myocardium treated with ginsenosides was significantly higher than that in the control group (N=10, p< 0.01), whereas the MDA in the myocardium treated with ginsenosides were markedly lower than that of the control group (p< 0.01). The amounts of oxygen free radicals in the myocardium treated with ginsenosides were significantly lower than that of the control group (p <0.001). This study demonstrates that ginsenosides, as a proper additive agent of cardioplegic solution, can decrease toxicity of oxygen free radicals, suggesting one of the mechanisms for its protective effects against myocardial ischemia and reperfusion injury.

Bcl-2 gene and its family genes Bax, Bcl-Xl as well as Fas/Apo-1 and their clinical significance in acute leukemia

OBJECTIVE

To study the suppressing genes of apoptosis, namely Bcl-2, its family genes Bax, Bcl-Xl, and the inducing gene of apoptosis Fas/Apo-1.

METHODS

The techniques of cytoimmuno-histiochemical stains, Western blotting and Northern blotting were used.

RESULTS

It was found that the antigens of Bcl-2 in acute myelogenous leukemia (AML) and acute lymphocytic (ALL) was higher than that in the normal (P < 0.01). At same time, Bcl-2 was obviously lower expression in complete remission (CR) group than that in non-remission (NR) one by retrospective analysis (P < 0.01). Though Bcl-2 was low expression in CR with Western blotting, there was no statistical significance (P > 0.05). In CR group the expression of Bcl-2 mRNA was obviously lower than that of NR one (P < 0.01). Even though leukemia expression of Bax with cytoimmuno-histiochemical stain was also lower than that in the normal people, there was no difference between CR and NR with cytoimmuno-histiochemical, Western blotting and Northern blotting (P > 0.05). There was difference of Bcl-Xl mRNA in two groups (P < 0.01). The expression Fas/Apo-1 in leukemia was lower than that in normal people (P < 0.01). But in CR and NR, there was no difference with cytoimmuno-histiochemical stain and Western blotting.

CONCLUSIONS

The Changes of genes and their proteins are significant theoretically and clinically. The antigen expression of Bcl-2 and the expression of Bcl-2 mRNA may be considered as a prognostic index for AML.

Systemic exposure to irradiated apoptotic cells induces autoantibody production

During apoptotic cell death, cell surface ligands initiate phagocytosis of the dying cell. Clearance of these apoptotic cells is thought to occur without an immune response. Since a number of autoantigens are located at the cell surface or within apoptotic blebs, we examined whether exposure of mice to syngeneic apoptotic cells by the intravenous route could induce autoantibody production. Normal mice injected with syngeneic apoptotic thymocytes developed antinuclear autoantibodies and anticardiolipin and anti-ssDNA antibodies. The autoantibody levels were generally lower than those observed in MRL/Faslpr mice and were transient. Surprisingly, six out of six immunized mice demonstrated immunoglobulin G deposition in the glomeruli several months after immunization. These findings indicate that systemic exposure to apoptotic cells can induce an immune response in normal mice, and may help to explain antigen selection and initiation of the immune response in diseases characterized by increased rates of apoptosis such as AIDS and, possibly, systemic lupus erythematosus.

Temperature selection and use of torpor by the marsupial Sminthopsis macroura

Many small mammals display daily torpor to minimize energy expenditure during the rest phase when faced with unfavorable environmental conditions. However, given a choice of thermal environments, it is not clear whether these daily heterotherms select ambient temperatures that minimize metabolic rates during torpor or ambient temperatures that minimize metabolic rates during normothermia. It is also not clear whether they prefer being normothermic or torpid. In this study, we investigated temperature selection, activity patterns, body temperature patterns, and the use of torpor in Sminthopsis macroura in a thermal gradient when food was freely available or restricted. Animals employed torpor regularly immediately after cessation of activity even when excess food was provided. Nevertheless, they selected high ambient temperature near the zone of thermoneutrality during both normothermia and torpor. Reduced food supply did not affect either temperature preference or total activity, but it did result in significantly prolonged torpor bouts. In addition, it lowered the daily minimum body temperature during torpor by about 2 degrees C. Our study shows that S. macroura selected a high ambient temperature to reduce energy costs during normothermia. Nevertheless, daily torpor was frequently employed at the high temperature, especially when food was restricted.

Modeling the developmental neurotoxicity of chlorpyrifos in vitro: macromolecule synthesis in PC12 cells

Exposure to apparently subtoxic doses of chlorpyrifos during late stages of brain development affects cell acquisition through a mixture of cholinergic and noncholinergic mechanisms. In the current study, we modeled these effects in vitro using rat pheochromocytoma (PC12), a cell line that, upon nerve-growth factor (NGF)-induced differentiation, develops the appearance and function of cholinergic target neurons, including the expression of cholinergic receptors. In the undifferentiated state (no NGF), chlorpyrifos evoked an immediate (1 h), robust, concentration-dependent inhibition of DNA synthesis as evaluated by [3H]thymidine incorporation, with a threshold of 0.5-1.5 microg/ml. Continuous exposure for up to 24 h maintained the same degree of inhibition. The effects were selective for DNA synthesis, as much smaller inhibitions were found for synthesis of RNA or protein. In contrast, direct cholinergic stimulation of the cells by 100 microM nicotine had much smaller effects on DNA synthesis. Moreover, the effects of chlorpyrifos on DNA synthesis could not be blocked by nicotinic or muscarinic antagonists, confirming that the effects were not mediated primarily through cholinergic hyperstimulation consequent to cholinesterase inhibition or to direct receptor-mediated effects. When PC12 cells underwent NGF-induced differentiation, the rate of cell replication fell dramatically and neurite extension was evident both from morphological examination and from biochemical markers (increased protein:DNA ratio). After introduction of NGF, chlorpyrifos maintained its ability to inhibit DNA synthesis acutely. However, the ability to inhibit RNA and protein synthesis initially intensified and then disappeared, indicating a shift in macromolecular targets as differentiation proceeded. We also tested the effects of long-term exposure to chlorpyrifos during the process of NGF-induced differentiation. Continuous chlorpyrifos exposure resulted in severe reductions in macromolecule synthesis and a deficit in the total number of cells, effects similar to those seen with chlorpyrifos treatment in vivo. At the highest concentrations, neurite extension was also inhibited. Our results suggest that chlorpyrifos can interact directly with developing neural cells to inhibit replication and neuritic outgrowth.

[Correlation of interleukin 1 beta-converting enzyme(ICE) gene expression with gut epithelial cell apoptosis in septic mice]

OBJECTIVE

To investigate the correlation of gut epithelial cell apoptosis with ICE, IL1 beta gene expression in septic mice.

METHODS

Sepsis was induced in mice by cecal ligation and puncture(CLP). Sham-operation group underwent the same manipulation but without CLP. 1, 3, 6 hours after CLP, gut epithelial cells, were isolated. IL1 beta, ICE gene expression was detected quantitatively by RT-PCR. Epithelial cell apoptosis was assessed by flow cytometric method and biochemically by DNA electrophoresis.

RESULTS

The survival rate of CLP mice was 1/10 as compared to 10/10 of sham-operation mice. IL1 beta, ICE mRNA expression in CLP mice was significantly higher than that in the sham-operation group(P < 0.01); IL1 beta mRNA expression was parallel to ICE mRNA expression. The number of epithelial cell apoptosis was correlated excellently to the level of ICE, IL1 beta mRNA expression. Epithelial cell apoptosis could not be detected in sham-operation group at the indicated time points.

CONCLUSION

ICE, IL1 beta gene overexpression may be involved in the vulnerability of epithelial cell apoptosis in septic mice.

[Detection of human papillomavirus infection in cervical Pap smears by computer-assisted cytologic test]

OBJECTIVE

The sensitivity and accuracy of cytologic computer-assisted test (CCT) in diagnosis of human papillomavirus (HPV) infection in cervical Pap smear were evaluated.

METHODS

Cervical Pap smears obtained from 158 patients with vulva condyloma acuminata were examined by CCT. The diagnostic criteria were based on The Bethesda System (TBS). Simultaneously HPV DNA in cervical mucus was examined by polymerase chain reaction (PCR) technique and cervical biopsy taken under the guidance of colposcopy for pathological examination.

RESULTS

The sensitivity and accuracy of CCT in diagnosis of cervical HPV infection were 74.62% and 67.72% compared with pathological results whereas 69.11% and 70.88% compared with PCR results respectively.

CONCLUSION

The results indicates that CCT, a cytologic pathological technique, is a useful method in diagnosis of clinical and subclinical cervical HPV infection.

[Iatrogenic peripheral nerve injuries and its repair]

In order to investigate the causes, diagnosis, treatment, outcome and prevention of iatrogenic nerve injury in the neck, 8 cases with iatrogenic nerve injuries were analyzed. Among them, 5 cases were accessory nerve injury, 3 cases were brachial plexus injury. All of the cases were treated by surgical methods, including neurolysis, repair by direct suture, nerve graft and transposition. After 1-3 years follow up the effect was excellent in 2 cases who were accessory nerve injury, good in 5 cases, and poor in 1 case who was brachial plexus injury. It was concluded that high responsibility of surgeons and careful manipulation during operation were the key to prevention of nerve injuries.

Alterations of cytoskeletal tau protein of SH-SY5Y human neuroblastoma cells after exposure to MPTP

In this study, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP, 10(-3) to 10(-4) M for 2 to 5 days) increased the expression of microtubule-associated tau protein in both the supernatant and pellet fractions of lysed SH-SY5Y human neuroblastoma cells. The western blot using anti-tau-1 antibodies demonstrated that the cells contained at least six isoforms of tau proteins, five with molecular weights from 45 to 62 kD. Reverse transcriptase polymerase chain reaction (RT-PCR) using primers coding whole length tau protein further confirmed the presence of tau in SH-SY5Y cells. The PCR product of tau in SH-SY5Y cells had approximately 1050 base pairs. MPTP caused an increased expression of the PCR product of tau, suggesting that the toxicant caused an increase in mRNA coding the tau protein. The expression of cytoskeletal tau protein may, therefore, provide a marker for MPTP neurotoxicity in SH-SY5Y cells.

Stimulation of phosphorylation of mitogen-activated protein kinase by 1alpha,25-dihydroxyvitamin D3 in promyelocytic NB4 leukemia cells: a structure-function study

Recent studies have shown that 1alpha,25-dihydroxyvitamin D3 [1alpha,25-(OH)2D3] actions in cell growth and differentiation are mediated by both its nuclear receptor (VDRnuc) and its rapid membrane-related effects. In the present study, we investigated the effect of 1alpha,25-(OH)2D3 on p42mapk phosphorylation using human acute promyelocytic leukemia cells (NB4). 1Alpha,25-(OH)2D3 (10[-8] M) significantly increased p42mapk phosphorylation in a time- and dose-dependent manner, with the earliest response detectable at 30 sec. Because 1alpha,25-(OH)2D3 is a conformationally flexible molecule, we have used a series of conformationally locked (6-s-cis vs. 6-s-trans) analogs to evaluate which shape is optimal for activation. Four 6-s-cis-locked analogs (HF, JM, JN, and JP) and two 6-s-trans-locked analog (JB and JD) were studied. HF, JM, JN, and JP all increased p42mapk phosphorylation at 1 and 5 min (10[-8] M), but JB and JD had little effect. Analog HL [1beta,25-(OH)2D3], a specific antagonist for only the rapid effects of 1alpha,25-(OH)2D3, attenuated 1alpha,25-(OH)2D3-induced p42mapk phosphorylation 65-90%. To assess the potential involvement of the VDRnuc in mediating the analog's action, the relative abilities of the analogs to compete with [3H]1alpha,25-(OH)2D3 for binding in vitro to the VDRnuc of NB4 cells was measured. All 6-s-cis analogs bound poorly to VDRnuc (relative competitive index, 0.5-2%) compared with 1alpha,25-(OH)2D3 (relative competitive index, 100%). The present studies demonstrate for the first time that in NB4 cells 1alpha,25-(OH)2D3 rapidly activates the p42mapk pathway, and that this effect can be selectively mediated by analogs that can assume a 6-s-cis conformation.

Modified bilateral cleft lip repair with orbicularis reconstruction and prolabial self-elongation

PURPOSE

This article describes the details of a modified method for bilateral cleft lip repair and presents some examples of patients whose condition was repaired by this technique.

PATIENTS AND METHODS

Sixty-five patients ranging in age from 2 to 5 years were treated with this modified procedure. The method was characterized by prolabial lengthening and reconstruction of the orbicularis oris muscle in one stage.

RESULTS

Satisfactory results were achieved with this method. The Cupid's bow and the central tubercle appeared more natural. None of the patients developed dehiscence of the wound.

CONCLUSIONS

This modified procedure is of special value for complete bilateral cleft lip patients with a short prolabium. The long-term effect of muscle reconstruction on maxillary growth remains to be evaluated.

1Alpha,25-dihydroxyvitamin D3 and phorbol ester mediate the expression of alkaline phosphatase in NB4 acute promyelocytic leukemia cells

Both 1alpha,25-dihydroxyvitamin D3 [1alpha,25(OH)2D3] and phorbol 12-myristate 13-acetate [PMA] are cytodifferentiation agents regulating myeloid cell line differentiation along the monocyte/macrophage pathway. Alkaline phosphatase (ALP) activity has been reported to be absent or present at low levels in monocytes/macrophages. In the present study, the acute promyelocytic leukemia cell line (NB4) was found to undergo monocyte/macrophage differentiation and strongly express ALP activity after exposure to the combination of 1alpha,25(OH)2D3 and PMA treatment. The ALP stimulation was both dose- and time-dependent with the ED50 doses for 1alpha,25(OH)2D3 and PMA at 2 x 10(-10) M and 4 x 10(-11) M, respectively. Assessment of the cell morphology via cell adherence, phagocytosis and ALP staining confirmed that NB4 cells treated by 1alpha,25(OH)2D3 plus PMA showed macrophage characteristics, but were also strongly stained with ALP. The present study is the first report that NB4 cells express ALP activity as a consequence of combination treatment with 1alpha,25(OH)2D3 and PMA.

[Studies on anti-inflammatory and immune effects of moxibustion]

An animal model of adjuvant arthritis in rats was established, and the effects of anti-inflammatory and immune regulation of moxibustion at "Shenshu" point were investigated. The results showed that it could lighten a local inflammatory reaction, eliminate swelling of the metatarsal and reduce it's girth, prevent or reduce the polyarthritises, maintain the weight and shorten the course of the disease. The results also showed that moxibustion could recover and promote the effects of the Concanavalin A (ConA) inducing splenic lymphocyte proliferation in rats, promote interleukin 2 (IL-2) production, decrease IL-1 contents. The indexes mentioned above were significantly different as compared with contral group. Above results indicated that moxibustion had directly anti-inflammatory and subsidence of swelling effects, through enhancing the ability of immune response the immune functions were lightened and regulated. Therefore, the anti-inflammatory and immune and anti-allergy effects of body were enhanced.

Thermal relations of metabolic rate reduction in a hibernating marsupial

We tested whether the reduction of metabolic rate (MR) in hibernating Cercartetus nanus (Marsupialia, 36 g) is better explained by the reduction of body temperature (Tb), the differential (delta T) between Tb and air temperature (Ta), or thermal conductance (C). Above the critical Ta during torpor (Ttc) of 4.8 +/- 0.7 degrees C where the Tb was not regulated, the steady-state MR was an exponential function of Tb (r2 = 0.92), and the overall Q10 was 3.3. However, larger Q10 values were observed at high Tb values during torpor, particularly within the thermoneutral zone (Q10 = 9.5), whereas low Q10 values were observed below Tb 20 degrees C (Q10 = 1.9). The delta T did not change over Ta 5-20 degrees C, although MR fell, and therefore the two variables were not correlated. Below the Ttc, Tb was regulated at 6.1 +/- 1.0 degrees C and MR increased proportionally to delta T. Our study suggests that MR in torpid C. nanus is largely determined by temperature effects and metabolic inhibition. In contrast, delta T explains MR only below the Ttc and C appears to affect MR only indirectly via changes of Tb, suggesting that delta T and C play only a secondary role in MR reduction during hibernation.

Elevation of protein kinase C in thyrocytes isolated from a Lewis rat model of autoimmune thyroiditis prevents assembly of immunodetectable connexin43 gap junctions and reduces intercellular communication

In the Lewis rat model of experimental autoimmune thyroiditis (EAT), decreased immunodetectable connexin assembly into gap junctions and diminished intercellular communication are associated with the loss of thyroid function (hypothyroidism) that occurs prior to significant tissue destruction. The current study explores the hypothesis that the loss of connexin 43 (Cx43)-mediated intercellular communication in these cells is caused by upregulation of protein kinase C (pKC) activity. Thyrocytes isolated from EAT rats exhibited a 78% increase in basal pKC activity; whereas, basal protein kinase A (pKA) activity was unchanged. Increased pKC activity was a result of increased isozyme protein levels. Thyroid cells expressed pKC isozymes gamma and lambda and had elevated levels of alpha (40%), beta (30%), delta (31%), and epsilon (25%) as quantified by western blot analyses. Furthermore, modulation of pKC activity inversely altered Cx43 assembly and function in monolayer thyrocytes. For example, octoacetyl glycerol (OAG) treatment of normal thyrocyte monolayers to increase pKC activity resulted in deficient Cx43 gap junction assembly and reduced intercellular communication indistinguishable from the deficits in EAT thyrocytes. Conversely, calphostin C inhibition of pKC activity in EAT thyrocyte monolayers restored these parameters to normal. Thus, pharmacological modulations of pKC activity in cultured thyrocytes support a causal relation between the changes in pKC activity and Cx43-mediated intercellular communication. Abnormalities in autoimmune diseased thyroid tissue (eg, increased pKC) appear to contribute to reduced intercellular coordination of thyroid follicles and thereby can affect subsequent thyroid function. The persistence of target cell abnormalities in the absence of infiltrating lymphocytes and their products supports an alternative mechanism by which thyroid function can be affected that does not depend on the loss of thyroid glandular epithelium.

[Image analysis of the microvascular permeability to various molecular weight of flucrescein in rat mesentery]

An intravital fluorescence microscopic method and digital image analysis were established for measuring the changes of fluorescein sodium (FINa, MW 376) and FITC-Dextrans (FD-4, MW4000, FD-150, MW150000) permeability in mesenteric microvessels. The transport of various molecular fluorescent tracer within the blood vessels and through the vessel walls into the perivascular tissue of the rat mesentery was studied using a highly sensitive CCD camera, the fluorescence intensities were transformed into video signals and recorded for subsequent analysis. The results showed that FINa could pass through the wall of microvessels very quickly. The diffusion constant was 3.362 x 10(-8) cm2/s with FINa, and FD-4 was 1.718 x 10(-8) cm2/s, FD-150 was 0.0486 x 10(-8) cm2/s. The diffusion constant depended very strongly on the molecular weight and showed no difference between capillary and vessels of the venous part of the microcirculation, but in vessels of the arterial part of microcirculation no diffusion was found. That was to say that diffusion occurred in capillary and microvenous, but not in microarterial. It is expected that this method would be very useful for the quantitive analysis in various molecular weights and in monolayer endothelial cell permeability.

Relative functions of the alpha and beta subunits of the proteasome activator, PA28

PA28 is a 180,000-dalton protein that activates hydrolysis of small nonubiquitinated peptides by the 20 S proteasome. PA28 is composed of two homologous subunits, alpha and beta, arranged in alternating positions in a ring-shaped oligomer with a likely stoichiometry of (alphabeta)3. Our previous work demonstrated that the carboxyl terminus of the alpha subunit was necessary for PA28 to bind to and activate the proteasome. The goals of this work were to define the exact structural basis for this effect and to determine the relative roles of the alpha and beta subunits in proteasome activation. Each subunit and various mutants of the alpha subunit were expressed in Escherichia coli and purified. PA28alpha stimulated the proteasome, but had a much greater Kact than native heteromeric PA28. In contrast, PA28beta was unable to stimulate the proteasome. Mutants of the alpha subunit in which the carboxyl-terminal tyrosine residue was deleted or substituted with charged amino acids could neither bind to nor activate the proteasome. However, substitution of the carboxyl-terminal tyrosine with other amino acids resulted in proteins which could stimulate the proteasome to various extents. Tryptophan mutants stimulated the proteasome as well as did native PA28, whereas serine or phenylalanine mutants stimulated the proteasome much poorer than did wild type PA28alpha. Deletion of the "KEKE" motif, a 28-amino acid domain near the amino terminus of PA28alpha, had no effect on proteasome stimulatory activity. Hetero-oligomeric PA28 proteins were reconstituted from isolated wild type and mutant subunits. PA28 reconstituted from wild type subunits had structural and functional properties that were indistinguishable from those of the native hetero-oligomeric protein. PA28 molecules reconstituted from inactive alpha subunits and wild type beta subunits remained inactive. However, PA28 molecules reconstituted from suboptimally active alpha mutants and wild type beta subunits had the same activity as native heteromeric PA28. These results indicate that the beta subunit modulates PA28 activity, perhaps by influencing the affinity of PA28 for the proteasome.

[The prognostic values of FCM determination of primary tumor and axillary lymph node of the patients with breast cancer]

Using Flow cytometry, we determined the ploidy and SPF on the primary tumor and axillary lymph node of 58 patients with breast cancer. Follow up for 5 years evealed that 23 patients had recurrence. 21 of them died. We conclude that the patients with aneuploid and high SPF have a higher relapce rate than those with diploid and low SPF, especially in those with advanced stage tumor or metastatic lymph node. It seems that ploidy and SPF of primary tumors affect more strong the prognosis of the patient than those of axillary lymph node. The probable cause of the recurrence of diploid tumor patients suggest post operation treatment for the patients with aneuploid cancer.

Cytotoxic effects of MPTP on SH-SY5Y human neuroblastoma cells

Morphological and metabolic endpoints were used to evaluate MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) toxicity to SH-SY5Y human neuroblastoma cells. After 8 hours of exposure, MPTP was found to affect cell viability only at a very high concentration (3 x 10(-3) M), but its metabolite MPP+ could decrease viability at 10(-4) M. MPTP, via its metabolite MPP+, inhibited NADH dehydrogenase activity when concentrations exceeded 10(-4) M (for MPP+ 10(-5)M). The Ki were 2.4 x 10(-3) M and 3 x 10(-4)M for MPTP and MPP+, respectively. MPTP at concentrations greater than 10(-4) M altered cell morphology as early as one hour after exposure. These changes included formation of cell surface blebs and attenuated neurites. After 8 hours at 10(-3) M and 24 hrs at 10(-4) M, MPTP caused ultrastructural changes of mitochondria with increased electron-density of the matrix and disorganization of cristae, as well as abnormal aggregation of filamentous material of the cytoskeleton. Because these changes of structure and function took place at concentrations lower than those needed to affect cell viability, they may play a role in MPTP neurotoxicity in SH-SY5Y cell culture.

Tumor necrosis factor alpha plays a central role in immune-mediated clearance of adenoviral vectors

Adenovirus (Ad) gene transfer vectors are rapidly cleared from infected hepatocytes in mice. To determine which effector mechanisms are responsible for elimination of the Ad vectors, we infected mice that were genetically compromised in immune effector pathways [perforin, Fas, or tumor necrosis factor alpha (TNF-alpha)] with the Ad vector, Ad5-chloramphenicol acetyl transferase (CAT). Mice were sacrificed at 7-60 days postinfection, and the levels of CAT expression in the liver determined by a quantitative enzymatic assay. When the livers of infected mice were harvested 28 days postinfection, the levels of CAT expression revealed that the effectors most important for the elimination of the Ad vector were TNF-alpha > Fas > perforin. TNF-alpha did not have a curative effect on infected hepatocytes, as the administration of TNF-alpha to infected severe combined immunodeficient mice or to infected cultures in vitro had no specific effect on virus persistence. However, TNF-alpha-deficient mice demonstrated a striking reduction in the leukocytic infiltration early on in the infection, suggesting that TNF-alpha deficiency resulted in impaired recruitment of inflammatory cells to the site of inflammation. In addition, the TNF-deficient mice had a significantly reduced humoral immune response to virus infection. These results demonstrate a dominant role of TNF-alpha in elimination of Ad gene transfer vectors. This result is particularly important because viral proteins that disable TNF-alpha function have been removed from most Ad vectors, rendering them highly susceptible to TNF-alpha-mediated elimination.

[Preparation of liposomes of superoxide dismutase]

The liposomes of SOD were prepared by reverse-phase evaporation. By examining the important effects on preparation we obtained the liposomes of SOD. The encapsulation of SOD was more than 60%, and the stability of the liposomes was excellent.

[The relationship between the prognosis of retinoblastoma and proliferating cell nuclear antigen and argyrophilic protein at nucleolus organizer regions]

OBJECTIVE

To investigate the relationship between the proliferative activity of retinoblastoma (Rb) cells and the prognosis of the tumor.

METHODS

Proliferating cell nuclear antigen (PCNA) and argyrophilic nucleolar organizer regions (AgNORs) in paraffin-embedded Rb specimens from 48 cases were detected by LSAB immunohistochemical method using an anti-PCNA monoclonal antibody and the technique of ploton.

RESULTS

The PCNA labeling index (PCNALI) and the AgNORs counts were well correlated (r = 0.647, P < 0.001). In 29 patients of the 48 cases receiving simple eyeball extirpation and being followed up for 5 years, the mean PCNALI and the mean numbers of AgNORs per nucleus in 19 patients surviving > or = 5 years after operation were markedly lower than that in 10 patients surviving < 5 years after operation (P < 0.01, P < 0.05).

CONCLUSION

It is indicated that the PCNALI or the AgNOR count is negatively related with the clinical prognosis of Rb patients, and can be useful in judging the prognosis.

Cellular mechanisms for developmental toxicity of chlorpyrifos: targeting the adenylyl cyclase signaling cascade

Developmental neurotoxicity caused by chlorpyrifos exposure is generally thought to target cholinesterase but chlorpyrifos may also act on cellular intermediates, such as adenylyl cyclase, that serve global functions in the coordination of cell development. In the current study, neonatal rats were exposed to apparently subtoxic doses of chlorpyrifos (no weight loss, no mortality) either on Postnatal Days 1-4 or on Postnatal Days 11-14, and the effects on components of the adenylyl cyclase cascade were evaluated in brain regions that are enriched (forebrain) or sparse (cerebellum) in cholinergic innervation, as well as in a nonneural tissue (heart). In all three, chlorpyrifos evoked deficits in multiple components of the adenylyl cyclase cascade: expression and activity of adenylyl cyclase itself, functioning of G-proteins that link neurotransmitter and hormone receptors to cyclase activity, and expression of neurotransmitter receptors that act through this cascade. Disruption of signaling function was not restricted to transduction of cholinergic signals but rather extended to adrenergic signals as well. In most cases, the adverse effects were not evident during the immediate period of chlorpyrifos administration, but appeared after a delay of several days. These results suggest that chlorpyrifos can affect cell development by altering the activity and reactivity of the adenylyl cyclase signaling cascade, a major control point for trophic regulation of cell differentiation. The effects are not restricted to cholinergic targets, nor even to the central nervous system. Hence, disruption of cell development by chlorpyrifos is likely to be more widespread than previously thought.

[Vitrectomy for extraction of intraocular foreign bodies]

OBJECTIVE

To evaluate the effect of treatment of intraocular foreign bodies (IOFBs) with vitrectomy and its influential factors.

METHODS

A retrospective research was done on 517 in-patients having undergone extraction of IOFBs with vitrectomy.

RESULTS

Postoperatively, the successful rate of the extraction of IOFBs was 97.6%, the rate of cases with useful vision (0.05 to 0.4) increased from preoperative 12.5% to 23.2% and that with good vision (0.5 and better) from 7.2% to 17.0% (P < 0.005). When IOFBs were located in anterior segment, vitreous and retina, the increasing rates of cases with useful vision respectively were 44.4%, 25.1% and 10.7%, and that of good vision were 26.3%, 12.7% and 2.7%.

CONCLUSIONS

Vitrectomy is favorable for the extraction of IOFBs, the increase of postoperative vision and the management of complications.