[Simultaneous determination of tungsten, molybdenum and titanium by k-factor dual-wavelength standard addition method]

In this paper, a new method for simultaneous spectropthotometric determination of tungsten, molybdenum and titanium is proposed. The method is based on the difference of absorption spectra of the three elements forming coloured complexes with PF in acidic medium and in the presence of nonionic surfactant Tween-80. The absorbance of sample was measured at wavelengths of 503, 530 and 560 nm, and the data were treated by the principle of the k coefficients and dual-wavelength standard addition method. The method has been applied to the determination of tungsten, molybdenum and titanium in steels, and satisfactory results were obtained.

[Cephalometric analysis of the craniofacial bony structures in patients with obstructive sleep apnea]

OBJECTIVE

To explore the craniofacial bony structure abnormalities and their possible contributions to the apneic severity in patients with obstructive sleep apnea (OSA).

METHODS

One-night polysomnographic examination and a lateral cephalogram were performed in 102 male OSA patients and 37 healthy men. Sixteen variables representing craniofacial angle, distances and areas were measured by a computer software (NIH Image).

RESULTS

Compared with normal subjects, OSA patients presented with: a shortened cranial base (71 +/- 4) mm: (74 +/- 3) mm, (P < 0.001), maxillum (52 +/- 5) mm: (55 +/- 4) mm, (P < 0.01), mandible (74 +/- 5) mm: (77 +/- 6) mm, (P < 0.05) and bony nasopharygeal airway dimensions, a more inferiorly and anteriorly placed hyoid bone, and retrognathia deformity. Multiple stepwise regression analysis disclosed that maxilla deficiency, retrognathia and hyoid bone misposition were important contributing factors to the apneic severity (R2 = 0.447, F = 15.471, P < 0.0001).

CONCLUSIONS

OSA patients had certain craniofacial bony structure defects and cephalometric analysis of these defects is useful both in the investigation of the pathogenesis and the selection of an optimel treatment modality for each OSA patients.

[Retreatment after excimer laser photorefractive keratectomy]

OBJECTIVE

To evaluate the efficacy and safety of reoperation of residual myopia because of regression, undercorrection with or without coexisting severe corneal haze after excimer laser photorefractive keratectomy (PRK).

METHODS

A VISK 20/20 excimer laser was used to treat myopia of -1.00 to -16.50 diopters (spherical equivalent) at corneal plane. 35 patients (51 eyes) who had residual myopia because of regression, undercorrection with or without coexisting severe corneal haze after initial PRK were retreated by using PRK and phototherapeutic keratectomy.

RESULTS

At 12 months after retreatment, the rates of uncorrected visual acuity more than or equal to 10/20 or 20/20 were 82.6% and 39.1% respectively, 100.0% and 50.0% in myopia up to -6.00 D, 73.3% and 33.3% in myopia of -6.25 to -16.50 D respectively. 86.3% of eyes were within +/- 1.00 diopters of desired emmetropia. Corneal haze after retreatment was not greater than that observed after initial procedures.

CONCLUSIONS

The residual myopia because of regression, undercorrection with or without severe corneal haze after initial PRK can be successfully retreated. Although the therapeutic result of retreatment of PRK is less successful than that of the initial procedure, retreatment appears to enhance it.

[Clinical analysis of 96 cases with pulmonary disease caused by nontuberculous mycobacteria]

OBJECTIVE

To study the clinical characteristics of nontuberculous mycobacteria (NTM) pulmonary disease.

METHODS

Ninety-six out of 173 cases with NTM pulmonary disease diagnosed through identification of mycobacterium strains isolated from 5,592 sputum acid-fast staining positive cases from 1981-1996 were selected, and a retrospective analysis was made.

RESULTS

According to Runyon classification, there were 14 cases with M. kansasii and 1 with M. marinum in type I, 4 with M. scrofulsceum in type II, 23 with M. intracellulare or M. avium in type III, 24 with M. chelonae and 30 with M. fortuitumin in type IV. Cases whose courses of disease were more than 10 years accounted for 31%. Main clinical symptoms included cough (78%), expectoration (71%), haemoptysis (58%) and fever (26%). Fifty-seven percent cases in X-ray chest film were seen lesions bilaterally, 42% in one side, 27% in the right and 15% in the left. One percent showed no obvious lesion in X-ray chest film. Excluding one case with incomplete data, the total resistance rate of NTM was 96% in other 95 cases, 93% in type I, 50%, 100% and 100% in type II, III, IV respectively. After antituberculous chemotherapy, sputum negative conversion was seen in 14 of 15 cases with type I NTM, 6 of 23 with type III and 14 of 54 with type IV, while definite data in 4 cases with type II were not available.

CONCLUSIONS

NTM pulmonary disease is characterized by long course of disease, nonspecific symptoms, high resistance rate and unsatisfactory therapeutic efficacy.

[Photorefractive keratectomy to correct myopic astigmatism]

The VISX 20/20 excimer laser was used to treat 260 eyes with myopia and myopic astigmatism of 166 patients. All patients were followed up for one year. The diopter of preoperative astigmatism was from -0.25-(- 4.00 D (-1.00 +/- 0.62 D). The diopter was lowered to -0.07 +/- 0.40 D at 6 months postoperatively (P < 0.05) and -0.06 +/- 0.39 D at 12 months postoperatively (P < 0.01). Photorefractive keratectomy (PRK) is effective and safe for myopic astigmatism.

[One-year-result of excimer laser for photorefractive keratectomy in very high myopia]

We corrected 53 cases (84 eyes) of very high myopia using photorefractive keratectomy (PRK) with VISX 20/20 excimer laser, and followed up the cases more than one year. The rates of visual acuity more than or equal to 0.5 or 1.0 were 81.0% and 23.9%, 75.0% eyes were within +/- 2.00 diopter of the desired emmetropia. Grade 2 or more severe corneal haze were presented in 13.1% eyes. PRK with VISX 20/20 excimer laser may be an effective method to correct very high myopia from -10.00 to -16.00 diopters.

[A clinical study on vaccine of Mycobacterium vaccae in treating pulmonary tuberculosis]

OBJECTIVE

To study the effect of vaccine of Mycobacterium vaccae on cell-mediated immunity and on treating patients with pulmonary tuberculosis.

METHODS

Seventy cases of pulmonary tuberculosis with smear positive and initial treatment were classified randomly into group I (35 cases) and group II (35 cases), receiving 2HRZS/4HR and 2HRZS/4HR plus vaccine of Mycobacterium vaccae regimens respectively. Thirty-one multi-drug resistant pulmonary tuberculosis cases were classified into group III, receiving 4 - 6 sensitive antituberculous drugs and vaccine of Mycobacterium vaccae. Improvement of clinical symptoms, resolution of pulmonary lesions, negative conversion of sputum and changes of immunological functions were observed.

RESULTS

No significant difference in improvement of symptoms was found in group I and group II (P > 0.05), and the improvement rate of clinical symptoms in group III was found more than 50%. X-ray resolution rates in 4th month were 83% and 89%, and cavity reducing rates 40% and 50% respectively in group I and group II, and no significant differences were found (P > 0.05). X-ray resolution rate was 29%, cavity reducing rate 7% and no deteriorated case was found in group III. Sputum negative conversion rates in 1st, 2nd, 3rd and 4th month were 23%, 51%, 83% and 97% respectively in group I, while 31%, 77%, 89% and 100% in group II, and 3%, 16%, 29% and 32% in group III. Significant difference was found between group I and group II in sputum negative conversion rate in 2nd month after treatment (P < 0.05). After treatment, values of lymphocyte transformation test (LTT), CD(3), CD(4) and CD(4)/CD(8) of the above 3 groups were all higher than that before the treatment (P < 0.05), level of tumor necrosis factor decreased in group II and IL-2, IL-6 increased in group III.

CONCLUSIONS

Vaccine of Mycobacterium vaccae is a good immunotherapy preparation, which promotes sputum negative conversion and activation of cell-mediated immunity.

[Immunophenotype and P-glycoprotein expression in CD7 positive adult acute myeloid leukemia]

OBJECTIVE

To study the immunophenotype and P-glycoprotein expression in CD7 positive adult acute myeloid leukemia (CD7+ AML).

METHODS

Morphology, P-glycoprotein, cytogenetics and immunophenotype were examined in 30 previously untreated CD7+ AML patients.

RESULTS

The CD7 positive rate was 11.4% in 262 AML patients. CD7+ AML patients had a significantly higher incidence of peripheral leukocytosis and blasts and FAB M1 subtype and were associated with CD34 and P-glycoprotein expression. 42.3% of CD7+ AML achieved complete remission with a median remission duration of 4 months, and a median time to CR of 48 days.

CONCLUSION

Patients with CD7+ AML are usually CD34 and P-glycoprotein positive. These patients had a lower CR rate and a shorter remission duration.

[The clinical and biological significance of megakaryocytic antigen expression in acute myeloid leukemia]

OBJECTIVE

To explore megakaryocytic (MK) antigen expression in previously untreated adult acute myeloid leukemia (AML) and its relation to the clinical and biological characteristics.

METHODS

Two hundred and eleven cases of AML were detected with flow cytometric immunofluorescence assay.

RESULTS

Twenty-seven cases (12.8%) were MK antigen positive with the higher positive rates in hybrid acute leukemia (45.5%) and acute monoblastic leukemia (24.1%). MK antigen expression was significantly correlated with CD34 antigen expression, high white cell count, high P-glycoprotein positivity and had no correlation with chromosome aberration. 33.3% of MK positive AML patients achieved complete remission which was significantly lower than that (71.9%) in MK negative cases.

CONCLUSION

MK antigen positive AML might derived from malignant transformation of hemotopoietic stem cell at earlier stage and the detection of MK expression was of values in predicting treatment effect and prognosis for adult AML.

Protein structure prediction in a 210-type lattice model: parameter optimization in the genetic algorithm using orthogonal array

We have applied the orthogonal array method to optimize the parameters in the genetic algorithm of the protein folding problem. Our study employed a 210-type lattice model to describe proteins, where the orientation of a residue relative to its neighboring residue is described by two angles. The statistical analysis and graphic representation show that the two angles characterize protein conformations effectively. Our energy function includes a repulsive energy, an energy for the secondary structure preference, and a pairwise contact potential. We used orthogonal array to optimize the parameters of the population, mating factor, mutation factor, and selection factor in the genetic algorithm. By designing an orthogonal set of trials with representative combinations of these parameters, we efficiently determined the optimal set of parameters through a hierarchical search. The optimal parameters were obtained from the protein crambin and applied to the structure prediction of cytochrome B562. The results indicate that the genetic algorithm with the optimal parameters reduces the computing time to reach a converged energy compared to nonoptimal parameters. It also has less chance to be trapped in a local energy minimum, and predicts a protein structure which is closer to the experimental one. Our method may also be applicable to many other optimization problems in computational biology.

Inhibition of adipose differentiation by phosphatidylinositol 3-kinase inhibitors

Phosphatidylinositol (PI) 3-kinase plays an important role in various cellular signaling mechanisms in several cell systems. The role of PI 3-kinase in adipose differentiation was investigated. For this purpose, we examined the effect of specific inhibitors of PI 3-kinase on the differentiation of two adipogenic cell lines, 1246 and 3T3-L1. The results show that two structurally different inhibitors of PI 3-kinase, i.e., LY294002 and wortmannin, blocked adipose differentiation in a time and dose-dependent fashion. The results from time- course studies indicated that PI 3-kinase activity is most important in the early phase (day 4 to day 6) of the differentiation program. The effect of PI 3-kinase inhibitor on the expression of the peroxisome proliferator-activated receptor (PPAR) gamma, a master regulator in adipogenesis induced during the differentiation process, was also examined. LY294002 significantly inhibited the induction of PPARgamma mRNA expression. During the initiation phase of adipogenesis (day 4 to day 6), the expression of PPARgamma was induced and LY294002 blocked the increase of expression of PPARgamma mRNA. The inhibition of expression of PPARgamma may provide a molecular mechanism for the action of PI 3-kinase inhibitors on adipose differentiation.

[Multiple factors analysis of formation of corneal haze after photorefractive keratectomy]

VISX 20/20 excimer laser was used to correct myopia from 1.00 to 16.00 diopters on 529 myopia eyes in 306 patients. All the patients were followed up for 3 to 12 months (8.1 +/- 3.1 months). At the 12th postoperative month, 0.5-3 grade corneal haze occurred in 62.1% of eyes in high myopia eyes, and only 8.8% in low and moderate myopia eyes (P < 0.01). The factors of formation of the corneal haze were the central corneal thickness, methods of removing epithelium and the number of laser pulses. The results suggest that the photorefractive keratectomy is regarded safe in correction of low and moderate myopia, but not in high myopia.

[The clinical effect after locally using mitomycin C during trabeculectomy in glaucoma]

To improve the function of filtering blebs after trabeculectomy, we divided randomly 44 patients (60 eyes) with moderate or late glaucoma into mitomycin C and control groups (30 eyes per group). Two small surgical sponges were soaked with 0.2 mg.ml-1 mitomycin C solution. One sponge was put on the top of the superficial scleral flap, the other was placed underneath the scleral flap and contacted with the bed of the scleral flap. After 5 minutes the wound was then irrigated with normal saline. All patients were followed up from 1 to 12 months (7.9 +/- 4.0 months). We found that: (1) functional filtering blebs were 92.9% in the mitomycin C group and 55.2% in the control group (P < 0.01), (2) the decreasing percentage of intraocular pressure (IOP) in the mitomycin C group was much more than that in the control group (P < 0.05), (3) the successful rates of the operation in MMC group were higher than that of the control group, and the visual field was effectively maintained in MMC group.

[Mitomycin C concentrations in rabbit ocular tissues after topical administration during glaucoma filtration surgery]

Using high-performance liquid chromatography, we measured Mitomycin C (MMC) concentrations in conjunctiva, sclera and aqueous of 22 rabbit eyes after single topical administration of 0.2 mg.ml-1 MMC during glaucoma filtration surgery. The peaks of MMC concentrations in conjunctiva, sclera, aqueous were 2.01 micrograms.g-1, 2.95 micrograms.g-1 and 0.16 microgram.ml-1 with half life of 0.63, 0.35 and 0.84 hours respectively. Irrigating the ocular surface with 20 ml of normal saline after MMC application reduced the peak drug concentration to 1/8 in conjunctiva, to 1/5 in sclera and to 1/3 in aqueous. The results showed that the MMC concentrations in conjunctiva and sclera were well above the ID50 of rabbit subconjunctival fibroblast (0.1 microgram.ml-1), and the concentration in aqueous was well below the level known to cause endothelium toxicity (approximately 0.2 mg.ml-1) and retinal toxicity (> 1.3 micrograms.ml-1). Therefore, 0.2 mg.ml-1 MMC can inhibit subconjunctival fibroblast effectively and has no side effect on visual function.

A gas chromatographic method for the sugar analysis of 3,6-anhydrogalactose-containing algal galactans

This paper describes a new gas chromatographic method for the compositional analysis of algal galactans containing 3,6-anhydrogalactose, which is readily destroyed in usual acid hydrolysis and methanolysis. Mercaptolysis of galactans was carried out under an anhydrous condition using the newly developed solvent system, an ethanethiolic HCl solution which had been prepared by blowing dry HCl gas into ethanethiol. By heating galactans in 0.5 N HCl/ethanethiol at 60 degrees C for 12 h, component sugars including 3,6-anhydrogalactose were released quantitatively as their diethyl mercaptals. The monosaccharide diethyl mercaptals were trimethylsilylated and analyzed by gas-liquid chromatography. Each component monosaccharide was detected as a single peak since neither anomeric nor structural isomers can be produced by mercaptolysis. Furthermore, the solvent system was improved by the addition of methanol in a ratio (2/1, v/v) of ethanethiol to methanol. Heating of galactans at 60 degrees C in 0.5 N HCl/[ethanethiol:methanol (2/1, v/v)] released more rapidly and quantitatively monosaccharide diethyl mercaptals without any formation of monosaccharide methyl glycosides. The present method was applicable to not only algal galactans but also algal powders.

What amino acid properties affect protein evolution?

We studied 10 protein-coding mitochondrial genes from 19 mammalian species to evaluate the effects of 10 amino acid properties on the evolution of the genetic code, the amino acid composition of proteins, and the pattern of nonsynonymous substitutions. The 10 amino acid properties studied are the chemical composition of the side chain, two polarity measures, hydropathy, isoelectric point, volume, aromaticity, aliphaticity, hydrogenation, and hydroxythiolation. The genetic code appears to have evolved toward minimizing polarity and hydropathy but not the other seven properties. This can be explained by our finding that the presumably primitive amino acids differed much only in polarity and hydropathy, but little in the other properties. Only the chemical composition (C) and isoelectric point (IE) appear to have affected the amino acid composition of the proteins studied, that is, these proteins tend to have more amino acids with typical C and IE values, so that nonsynonymous mutations tend to result in small differences in C and IE. All properties, except for hydroxythiolation, affect the rate of nonsynonymous substitution, with the observed amino acid changes having only small differences in these properties, relative to the spectrum of all possible nonsynonymous mutations.

[Internalization and replication of Edwardsiella tarda in HEp-2 cells]

It is demonstrated that Edwardsiella tarda possesses the ability to invade cultured epithelial HEp-2 cells by both lysis-counting assay and thin-section electron microscopy. Among fifteen strains of E. tarda, 6 strains internalized into HEp-2 cells and located mainly in vesicles. After internalization, the bacteria replicated in the host cells and then released into medium. Pretreatment of the HEp-2 cells with various concentration of cytochalasin D (0.1-5.0 micrograms/ml) or cytochalasin B (2.5-10.0 micrograms/ml) significantly reduced the amount of internalized bacteria in a dose-dependent manner. While pretreatment of HEp-2 cells with 0.25-100 mumol/L colchicine did not show any effect on the invasiveness of E. tarda. This strongly indicates that microfilaments are required for the internalization of E. tarda into HEp-2 cells and that microtubules are not involved in the entrance of E. tarda into HEp-2 cells.

Regulation of mouse colony-stimulating factor-1 gene promoter activity by AP1 and cellular nucleic acid-binding protein

Macrophage colony-stimulating factor (M-CSF; CSF-1) is a member of a complex network of cytokines that regulate monocytic cell development and activity. It is produced in nearly all organs by cell types commonly found in connective tissue, including fibroblasts and monocytes. Whether different cell types share common or have divergent mechanisms for regulating CSF-1 gene expression is not known. To address this question, the identity of cis-acting elements and cognate trans-acting factors was characterized in a region of the CSF-1 promoter known to be more active in monocytes than in fibroblasts. The results of DNase I protection assays performed with fibroblast- or monocyte-derived nuclear extracts revealed a difference in the pattern of DNA-binding proteins. One protected region, common to both fibroblasts and monocytes, spans a putative phorbol ester-responsive element (TRE), and binding to the TRE by AP1 was verified with antibodies directed against c-fos and c-jun family members. Mutational analysis revealed that the TRE is required for CSF-1 gene expression in proliferating fibroblasts and monocytes. Binding of a second putative trans-acting factor, preferentially expressed in fibroblasts, to the region immediately upstream of the TRE was also detected. Screening a mouse expression library with oligonucleotides spanning the putative cis-acting element identified cellular nucleic acid-binding protein (CNBP) as the cognate binding activity, and antiserum to CNBP disrupted the electromobility shift assay complex. Mutational analysis revealed that loss of CNBP binding leads to a decrease in CSF-1 promoter activity in fibroblasts but has no effect on CSF-1 promoter activity in monocytes. Our results demonstrate that control of CSF-1 gene expression in monocytes and fibroblasts is mediated by common and cell type-specific trans-acting factors.

[Effects of polysaccharide of Polygala aureocauda on the immunnity functions of normal mouse]

The effects of polysaccharide of polygala aureocauda on the immunity functions of the normal mouse were researched by the tests of clearing away carbon granules, hemolysin antibodies production and lymphocyte transformation. The results showed that the polysaccharide of polygala aureocauda Dunn. (PADTP) could strengthen the phagocytosis of the single nucleus phagocytes, promote the production of the antibodies, and raise the transformable rate of the lympocytes. That proved the PADTP could strengthen immunity function of the normal mouse.

[Investigation on the epidemiology of Histoplasma capsulatum infection in Nanjing district]

Two hundred and ninety-two permanent or temporary residents in Nanjing district were tested with histoplasmin (Histolyn-CYL, ALK/Berkeley Laboratories, USA) and PPD. Forty-nine (16.78%) subjects reacted to histoplasmin with 5.0-23.0 (9.5 +/- 4.2) mm induration. Positive reaction rate among people without pulmonary diseases (normal group) was 15.10% comparing to 17.74% to patients with pulmonary diseases. Positive reaction to PPD with 5-50 (14.2 +/- 4.7) mm induration was 56.16%, with 59.43% in normal group and 54.30% in patients with pulmonary diseases while 8.90% subjects reacted to both histoplasmin and PPD, 7.88% of the research subjects reacted to histoplasmin but not to PPD. Result suggested that there was herd infection of Histoplasma capsulatum in Nanjing district.

[Appllcation of PYGC and the hierarchical clustering analysis to recognization of viruses]

The pyrolysis gas chromatography of 29 strains nuclear polyhedrosis viruses, 11 strains cytoplasmic polyhedrosis viruses and 16 strains granulosis viruses were performed on a shimadzu GV-9A capillary gas chromatography equipped with a pyrolyser model PYR-2A. The differences among the inclusion bodies of NPV, CPV and GV could clearly be distinguished and also beidentified through analysis of fingerprinting the hierarchical clustering analysis of GC, This procedure has provided a usefel method for the classification and identification of viruses.

Pea polyubiquitin genes: (I) structure and genomic organization

Four polyubiquitin genes, PUB1, PUB2, PUB3 and PUB4, were isolated from a pea (Pisum sativum L. cv Alaska) genomic library and completely sequenced. They represent all of the four polyubiquitin genes of the ubiquitin gene family in pea. The coding regions of the genes contain five or six coding units arranged as tandem repeats. The different coding repeats of the four genes share homologies between 75 and 97%, encoding the same protein of 76 amino acids identical to those from other higher plants. The open reading frames of PUB1, PUB2 and PUB4 terminate in the additional amino acid, phenylalanine (F), and PUB3 terminates in isoleucine (I). The polyubiquitin genes all contain intron sequences ranging from 584 to 1114 bp immediately 5' to the ATG initiation codon of the first coding sequence. Of the four genes, three are associated with long AT-rich (85.4-89.4% A+T) sequences ranging from about 331 to 478 bp at their 5' or 3' ends. The PUB4 gene was found to be linked to a moderate to highly repetitive DNA at its 5' flanking sequence. The greater sequence homology between different genes than among individual repeating units of a gene suggests that the polyubiquitin genes may have arisen by gene duplication of a single gene sequence.

[Prognostic significance of P-glycoprotein expression in acute leukemia in adults]

OBJECTIVE

To explore the prognostic significance of P-glycoprotein (P-gp) expression in previously untreated acute leukemia in adults.

METHODS

P-gp expression in 151 acute myeloblastic leukemia (AML) and 47 acute lymphoblastic leukemia (ALL) was determined by monoclonal antibody UIC2 and flow cytometry.

RESULTS

The rate of complete remission (CR) differed between P-gp+ and P-gp- AML (20.5% vs 78.5%, P < 0.001), but the CR rate did not significantly differ between P-gp+ and P-gp- ALL(66.7% vs 80%, P > 0.05). The six-month relapse rate was significantly higher in P-gp+ group than that of P-gp- group (AML: 66.7% vs 8.7%, P < 0.001; ALL: 50% vs 9.5%, P < 0.05). The median disease-free survival time was shorter in P-gp+ group than in P-gp- group (AML: 5 months vs 13 months; ALL: 4 months vs 13 months).

CONCLUSION

Overexpression of P-gp is a poor prognostic factor in adult acute leukemia and P-gp detection is useful for the prediction of treatment response and early relapse.

[Effect of AHMED valve implantation surgery for the treatment of neovascular glaucoma]

PURPOSE

To evaluate the efficacy of the valve implantation for the treatment of neovascular glaucoma.

METHODS

15 cases (15 eyes) neovascular glaucoma were treated with AHMED valve implantation surgery, and followed up for 6 to 42 months.

RESULTS

The IOP of the cases is lowered from 6.01 +/- 1.28 kPa (1 kPa = 7.5 mmHg) preoperatively to 1.96 +/- 0.68 kPa postoperatively. The success rate was 80.0% (The criteria of success is 0.80 kPa < or = IOP < or = 2.80 kPa and without severe complication that influence the visual acuity). The common postoperative complications included hyphema, shallow anterior chamber.

CONCLUSION

The AHMED valve implantation surgery can lower the IOP, increase the operative success rate and preserve the visual function effectively. It is regarded to be an effective, safe method to treat neovascular glaucoma.