Dentinogenesis imperfecta 1 with or without progressive hearing loss is associated with distinct mutations in DSPP

Dentinogenesis imperfecta 1 (DGI1, MIM 125490) is an autosomal dominant dental disease characterized by abnormal dentin production and mineralization. The DGI1 locus was recently refined to a 2-Mb interval on 4q21 (ref. 1). Here we study three Chinese families carrying DGI1. We find that the affected individuals of two families also presented with progressive sensorineural high-frequency hearing loss (gene DFNA39). We identified three disease-specific mutations within the dentin sialophosphoprotein gene (DSPP) in these three families. We detected a G-->A transition at the donor-splicing site of intron 3 in one family without DFNA39, a mutation predicted to result in the skipping of exon 3. In two other families affected with both DGI1 and DFNA39, however, we identified two independent nucleotide transversions in exons 2 and 3 of DSPP, respectively, that cause missense mutations of two adjacent amino-acid residues in the predicted transmembrane region of the protein. Moreover, transcripts of DSPP previously reported to be expressed specifically in teeth are also detected in the inner ear of mice. We have thus demonstrated for the first time that distinct mutations in DSPP are responsible for the clinical manifestations of DGI1 with or without DFNA39.

Directed evolution of operon of trehalose-6-phosphate synthase/phosphatase from Escherichia coli

Trehalose is a nonspecific protective agent for biomacromolecules. Trehalose-6-phosphate synthase (OtsA)/phosphatase (OtsB), which is encoded by the gene operon otsBA located at -42 of the Escherichia coli genome, is the main enzyme system that catalyzes the synthesis of trehalose in E. coli. We cloned the operon and modified it by directed evolution. Unlike in the previously reported work, we modified the whole operon and screened the positive mutant simultaneously. Thus we believe that the gene complex solves the negative effects between two enzymes if one of them diversifies its structure or functions and finds the form most suitable for trehalose synthesis. It thus mimics the natural process, in which the functional improvement of organisms is related to alterations in coordinated enzymes. The evolution procedure was carried out in a sequence of error-prone PCR, shuffling PCR, and then strict screening of the mutants. After screening of a library of more than 4000 colonies, about 15 positive colonies were analyzed, resulting in a higher concentration of trehalose than control. One of them, E. coli TS7, shows 12.3-fold higher trehalose synthesis ability than E. coli DH5alpha. In contrast, we introduced the cDNA sequence of the tps1 gene from Saccharomyces cerevisiae, which has 54% identity with the gene otsA, as one of the templates in shuffling PCR. By hybrid evolution and screening, we obtained 10 positive colonies with higher concentrations of trehalose than control. E. coli TS22 appears to have 5.3-fold higher trehalose synthesis ability than E. coli DH5alpha and 1.6-fold more than E. coli DEF3(pOTS11). This result demonstrated that coevolution and hybrid evolution, as powerful protocols in protein engineering, are effective in modifying enzyme. It indicates that repeating the process of genomic evolution in nature is feasible.

Blocking intercellular adhesion molecule-1 on human epithelial cells decreases respiratory syncytial virus infection

The respiratory syncytial virus (RSV) causes potentially fatal lower respiratory tract infection in infants. The molecular mechanism of RSV infection is unknown. Our data show that RSV colocalizes with intercellular adhesion molecule-1 (ICAM-1) on the HEp-2 epithelial cell surface. Furthermore, a neutralizing anti-ICAM-1 mAb significantly inhibits RSV infection and infection-induced secretion of proinflammatory chemokine RANTES and mediator ET-1 in HEp-2 cells. Similar decrease in RSV infection is also observed in A549, a type-2 alveolar epithelial cell line, and NHBE, the normal human bronchial epithelial cell line when pretreated with anti-ICAM-1 mAb prior to RSV infection. Incubation of virus with soluble ICAM-1 also significantly decreases RSV infection of epithelial cells. Binding studies using ELISA indicate that RSV binds to ICAM-1, which can be inhibited by an antibody to the fusion F protein and also the recombinant F protein can bind to soluble ICAM-1, suggesting that RSV interaction with ICAM-1 involves the F protein. It is thus concluded that ICAM-1 facilitates RSV entry and infection of human epithelial cells by binding to its F protein, which is important to viral replication and infection and may lend itself as a therapeutic target.

[Decomposition of aqueous sodium pentachlorophenolate (PCP-Na) by using TiO2 coating photocatalyst]

Titanium dioxide (TiO2) photocatalysts were coated on hollow glass beads by sodium silicate (Na2SiO3.9H2O) solution. The coated catalysts were characterized by BET, XRD. Their photoactivity were examined using photocatalytic degradation of sodium pentachlorophenolate(PCP-Na) and glucose solution. The impact of catalysts dosage, PCP-Na initial concentration, initial pH and oxygen concentration on reaction kinetics were also studied in detail. The experiments illustrated that the performance of C3-type catalysts was satisfactory. Conditions of the experiments were following: The initial concentration of PCP-Na and CODCr were 10 mg.L-1 and 400 mg.L-1, respectively, and illumination time was 2 hours and catalysts dosage was 2 g.L-1, the removal rates of CODCr and PCP-Na were above 65% and 92% respectively. Optimum dosage of C3-type catalysts was 2-2.5 g.L-1, DO was no less than 3 mg.L-1.

Pulmonary sequestration: three dimensional dynamic contrast-enhanced MR angiography and MRI

In order to evaluate the diagnostic value of three-dimensional contrast-enhanced MR angiography and MRI for pulmonary sequestration, 5 patients with pulmonary sequestration underwent 3D fast imaging by steady state precession (FISP) with a contrast medium and breath holding following chest radiography, CT and MR scans. The reconstructed MR angiography was performed using maximum intensity projection (MIP) and multiplanar reconstruction (MPR) techniques. It was found that the chest radiography showed pulmonary sequestration as a persistent area of opacity in the posterior basal segment of the left lower lobe, which was close to mediastinum in 2 cases and close to diaphragma in 3 cases. CT revealed a soft issue mass beyond descending aorta and lobar emphysema around the pulmonary sequestration. And the supplying vessel was documented in 2 cases on enhanced CT. MRI demonstrated a hyperintensity mass with respect to normal lung parenchyma on T1WI and T2WI, and the origin of the supplying vessel in 3 cases. The reconstructed CE MRA using MIP or MRP techniques clearly showed the supplying vessel and its course, branches as well as draining vessels. It was concluded that 3D CE MRA of demonstrating the supplying and draining vessels to pulmonary sequestration, together with plain MRI, can provide a diagnosis and aid in surgical planning without the need for DSA.

Anti-viral activity of hairpin ribozyme directed against HBV core region in vitro

To study the preparation and cleavage of hairpin ribozyme (HpRz) directed against the transcript of HBV core region in vitro, HRz gene designed by computer targeting the transcript of HBV core gene was cloned into the vector p1.5 between 5'-cis-Rz and 3'-cis-Rz. 32P-labeled HpRz transcript proved whether the vector fit for the preparation of hairpin ribozyme. 32P-labeled pKC transcript containing HBV core region as targets-RNA was transcribed by using T7 RNA polymerase and purified by PAGE. Cold HpRz transcript was incubated with 32P-labeled target-RNAs under different conditions and radioautographed after denaturing polyacrylamide gel electrophoresis. The results showed that HpRz had the ability of cleavage at 37 degrees C and 12 mmol/L MgCl2 and the design of ribozyme was correct. It is concluded that HpRz prepared in vitro possesses specific catalytic activity, indicating that it is possible for HpRz to intracellularly inhibit the replication of HBV. It may be developed into a nucleic acid drug in the treatment of hepatitis B in the future.

Determination of internucleotide (h)J(HN) couplings by the modified 2D J(NN)-correlated [(15)N, (1)H] TROSY

Recent developments in the direct observation of J couplings across hydrogen bonds in proteins and nucleic acids provide additional information for structure and function studies of these molecules by NMR spectroscopy. A J(NN)-correlated [(15)N, (1)H] TROSY experiment proposed by Pervushin et al. (Proc. Natl. Acad. Sci. USA 95, 14147-14151, 1998) can be applied to measure (h)J(HN) in smaller nucleic acids in an E.COSY manner. However, it cannot be effectively applied to large nucleic acids, such as tRNA(Trp), since one of the peaks corresponding to a fast relaxing component will be too weak to be observed in the spectra of large molecules. In this Communication, we proposed a modified J(NN)-correlated [(15)N, (1)H] TROSY experiment which enables direct measurement of (h)J(HN) in large nucleic acids.

Near-infrared spectrophotometric determination of tri- and tetrapeptides

A new method based on the near infrared technique has been developed for the noninvasive and nondestructive determination of the identity and sequences of amino acid residues in small peptides. The method is capable of distinguishing not only peptides with very similar structures (e.g., Gly-Ala-Ala, Gly-Ala-Leu, Leu-Gly-Gly and Gly-Leu-Leu-Gly, Gly-Leu-Gly-Gly, Gly-Gly-Ala-Gly) but also peptides with the same amino acid residues but different sequences (e.g., Gly-Ala-Ala, Ala-Gly-Ala, Ala-Ala-Gly and Gly-Gly-Gly-Ala, Gly-Gly-Ala-Gly).

[Influence of mannitol on early enlargement of hematoma in hypertensive cerebral hemorrhage]

OBJECTIVE

To probe into the influence of mannitol on early enlargement of hematoma in hypertensive cerebral hemorrhage, and to discuss how to use mannitol correctly.

METHODS

93 patients with hypertensive supratentorial non-thalamic cerebral hemorrhage and light intracranial hypertension, and with less than 30 ml of hematoma volume determined by cranial CT within 6 h after the onset were randomly divided into a group in which mannitol was used (n = 46) or a group in which mannitol was not used (n = 47) within 24 h. Cranial CT was redone at 48 h. If the volume of hematoma increased by 33%, it was named early enlargement of hematoma. The influence of using mannitol within 24 h after the onset on early enlargement of hematoma was analyzed.

RESULTS

14(14/46) patients in the group in which mannitol was used within 24 h after the onset had early enlargement of hematoma, yet 4(4/47) patients in the group without mannitol had hematoma enlargement. There was significant difference between them (P < 0.01). No significant difference was seen between the integral of nerve function defect in the two groups when CT was done at the first time (P > 0.05). When CT was redone, the integral of nerve function defect in the group with mannitol used within 24 h was markedly higher than that in the group without mannitol (P < 0.05). 5(5/46) patients died in the former group and 1(1/47) in the latter.

CONCLUSION

Improper use of mannitol within 24 h after the onset may increase the incidence of early enlargement of hematoma in patients with hypertensive cerebral hemorrhage, and exacerbate the patient's condition. For patients with hypertensive cerebral hemorrhage with light intracranial hypertension, especialy those within 24 h after the onset, mannitol should not be used blindly, in case that it enlarges the hematoma and exacerbates patient's condition.

[Determination of the composition distribution of polymer blend films by using microscopic FTIR]

In this paper, PS/PC blend film (about 120 microns thick) and PS/PMMA (about 90 microns thick) blend film were prepared by evaporation the solvent very slowly from polymer blend solution. Different FTIR methods were used to determine the composition distribution along the vertical direction of the films. PS/PC film was firstly sectioned by ultramicrotomy, then the vertical section was measured to determine the composition of every 16 microns width unit from the surface-side to the bottom-side by Microscopic transmission-FTIR. The results showed that the concentration of PS was significantly greater in the vicinity of the surface of the film than that in the bulk, i.e., the component of PS enriched to the surface. Focusing the reflecting infrared light on different layer of the film, we can detect the composition of the different depth region in the PS/PMMA blend film. As the result, PMMA aggregated to the bottom of the film. It was considered that this effect was related to the different affinity and wetting prosperities of the blend component to the substrate or air.

Refinement of the locus for autosomal dominant hereditary gingival fibromatosis (GINGF) to a 3.8-cM region on 2p21

Hereditary gingival fibromatosis (HGF, MIM 135300; approved gene symbol GINGF) is an oral disease characterized by enlargement of gingiva. Recently, a locus for autosomal dominant HGF has been mapped to an 11-cM region on chromosome 2p21. In the current investigation, we genotyped four Chinese HGF families using polymorphic microsatellite markers on 2p21. The HOMOG test provided evidence for genetic homogeneity, with evidence for linkage in four families (heterogeneity versus homogeneity test HOMOG, chi(2) = 0. 00). A cumulative maximum two-point lod score of 5.04 was produced with marker D2S390 at a recombination frequency of &theta; = 0 in the four linked families. Haplotype analysis localized the hereditary gingival fibromatosis locus within the region defined by D2S352 and D2S2163. This region overlaps by 3.8 cM with the previously reported HGF region. Single-strand conformation polymorphism and sequence analysis of the coding region of cytochrome P450 1B1 (CYP1B1) excluded it as a likely candidate gene.

[Study on typing of respiratory syncytial viruses]

OBJECTIVE

To determine the epidemiologic patterns of subgroups A and B and genotypes of respiratory syncytial viruses (RSV) during two uncontinuously epidemic years from 1990 to 1991 and 1997 to 1998 in Beijing.

METHODS

Nasopharyngeal secretion (NPS) samples of RSV positive or BSV isolates tested by indirect immunofluorescent (IIF) assay were classified into subgroups A and B. Also, isolates of RSV were divided into at least six different lineages, designated NPl-6, by restriction mapping of the N gene. NP l, 3 and 6 were given by subgroup B isolates, while NP2, 4 and 5 were given by subgroup A isolates. Strains of subgroup A were further subdivided into six lineages SHL 1-6 on the basis of the SH gene sequence. SH lineages were closely related to each other and to NP 1-6. Strains of SHL 1,3, and 4 were closely related and belonged to NP2, SHL 2 and 6 to NP4 and SHL5 to NP5.

RESULTS

Of 145 RSV NPS samples from the winter 1997 to the spring 1998, 83(57.2%) were subgroup B strains, 62(42.8%) were sub-group A strains, the rate of occurrence of subgroup A to B strains was about 1:1.3. Two of 10 isolates of 1997-1998 offered by viral department of research institute of Pediatrics were subgroup A strains, whereas 8 were subgroup B strains, the rate of occurrence of subgroup A to B strains was 1:4. Eight subgroup A strains of 10 isolates from the 1990-1991 epidemic were dominant, the proportion of subgroup A to B strains was 4:1. of 10 BSV isolates in 1997-1998, all 2 subgroups A strains gave N gene fragment restriction pattern NP4, and fell into SH lineage SHL2, whereas 8 subgroup B strains all belonged to NP3. All 8 subgroup A isolates from the 1990-1991 epidemic gave pattern NP4, and fell into SHL2, while 2 subgroups B strains all belonged to NP3. The classification of subgroups A and B deduced from NP patterns was corresponded to the definition of these subgroups by monoclonal antibodies.

CONCLUSIONS

These observations confirmed that subgroups A and B or multiple lineages of BSV co-circulated in Beijing, but different genomic types predominated each year. Moreover, very similar viruses were isolated up to more than 5 years ago, indicating that despite apparent diversity of the subgroup A strains, the separate lineages might be relatively stable.

A J-multiplied HMQC (MJ-HMQC) experiment for measuring (3)J(HNHalpha) coupling constants

The J-multiplied HSQC experiment (MJ-HSQC: S. Heikkinen et al., J. Magn. Reson 137, 243 (1999)) amplifies J coupling constants m times and allows direct observation of the (3)J(HNHalpha) coupling constants of peptides and proteins (<10 kDa). The drawbacks to this method are line broadening in the f(1)-dimension and lower sensitivity. In the J-multiplied HMQC (MJ-HMQC) experiment described here, the PEP-HSQC pulse sequence is replaced by a sensitivity-enhanced HMQC section, and the total decay time for the J-coupling and the chemical shift evolution is shortened by a period of t(1). This experiment affords narrower linewidth and enhances the sensitivity by 34%, on an average of 105 well-isolated peaks, when compared with the MJ-HSQC experiment.

Injury detection for central nervous system via EEG with higher order crossing-based methods

Higher order crossing (HOC) is a powerful tool for time series analysis. Two HOC-based EEG analysis methods are developed for brain injury detection and quantification. The first method explores EEG spectrum characteristics via an estimate of the dominant frequency of a pre-processed EEG signal. The second method is based on the norm of the AHOC, an HOC obtained from the alpha-filter prefiltered EEG signal. Both methods are shown to be effective in detecting hypoxic/asphyxic injuries as well as assessing the severity of the injury.

Sensitivity enhancement of HCACO by using an HMQC magnetization transfer scheme

Previous theoretical calculations have demonstrated that the multiquantum relaxation rate of (1)H(alpha)-(13)C(alpha)(R(MQ)) is, on average, 1.3 +/- 0.4 or 1.7 +/- 0.6 times slower than the single-quantum relaxation rate of (13)C(alpha)(R(C)) for a sample with or without, respectively, amide protons. By taking advantage of this fact and by using the PEP sensitivity enhancement scheme, an HMQC version of the HCACO experiment has been developed. We demonstrate that this new experiment is 23 and 55% more sensitive than the original HSQC version of the HCACO experiment, at constant times of 7 and 27 ms, respectively, for a sample of the BC domain of the ciliary neurotrophic factor receptor protein dissolved in D(2)O at 20 degrees C.

The value of in-phase and opposed-phase T1-weighted breath-hold FLASH sequences for hepatic imaging

The value of the combined in-phase (IP) and opposed-phase (OP) T1-weighted (T1-W) breath-hold FLASH sequences for hepatic imaging, especially for fat content, was evaluated. Non-contrast-enhanced IP and OP T1-W GRE breath-hold images were obtained in 76 patients refereed for abdominal MRI at 1.5T. 76 patients were divided into three groups for analysis: (1) liver without mass (n = 8); (2) liver with hepatoma (n = 34); (3) liver with haemangioma or cyst (n = 34). Liver/spleen and liver/lesion signal-to-noise (SNR) and contrast-to-noise ratio (CNR) were assessed for lesion detection. Images between IP and OP sequences were compared quantitatively. The results showed that there was not statistically significant difference in liver/spleen and liver/lesion SNR between IP and OP sequences. In the patients with fatty infiltration, the OP sequences yielded substantially lower values for liver/spleen and liver/lesion SNR than those of the IP sequences. Furthermore, OP imaging showed fatty infiltration in 14 cases and demonstrated hyperintense peritumor rim in 4 cases. In 14 cases of fatty infiltration, many lesions were identified using IP images. The use of IP and OP GRE sequences provides complementary diagnostic information for hepatic lesions and fat content. Focal hepatic lesions may be obscured in the setting of fatty infiltration if only OP sequences are employed. A complete assessment of the liver with MR should include both IP and OP imaging.

[Expression of VEGF and tumor angiogenesis in bladder cancer]

OBJECTIVE

To evaluate expression of vascular endothelial growth factor (VEGF) and its relation to angiogenesis in bladder cancer.

METHODS

The expression of VEGF by immunohistochemical staining was examined in 68 cases of primary transitional carcinoma (TCC) and 7 subjects with normal urothelium. Microvessel density (MVD) in 40 cases of invasive bladder cancer was determined by Factor VIII immunohistochemical staining.

RESULTS

The expression of VEGF was negative or low level in all normal bladder tissue but high in bladder cancer. VEGF and MVD were closely related to tumor cell nuclear grade and clinical stage. The average MVD was higher in the cases with the high level expression of VEGF, than in those with the low level expression of VEGF.

CONCLUSIONS

This study indicates that VEGF is positively correlated with the occurrence and progression of bladder cancer. VEGF is one of the primary angiogenic factors for bladder cancer, and is able to induce tumor angiogenesis and accelerate tumor growth. Quantification of VEGF may provide a valuable marker for a poorer prognosis of patients.

Effect of integrin on procollagen synthesis by fibroblasts from scleroderma

OBJECTIVE

To investigate the effect of integrin on fibroblasts from scleroderma in the production of procollagen.

METHODS

Phosphorothioate modified antisense oligonucleotides were used to interfere with the expression of integrin alpha 5 or beta 1 subunit on fibroblasts from 10 cases of scleroderma, and then the changes of procollagen mRNA due to the decline in level of integrin were observed by using RT-PCR.

RESULTS

Expression of integrin alpha 5 or beta 1 subunit was specifically inhibited by their corresponding antisense oligonucleotides. Fibroblasts with decreased expression of alpha 5 or beta 1 subunit produced lower level of procollagen alpha 1 (I), alpha 1 (III) mRNA in comparison to the control.

CONCLUSION

Overproduction of procollagen may be inhibited at the level of transcription by lowering the expression of integrin alpha 5 or beta 1 subunit on fibroblasts in scleroderma.

Context-based lossless and near-lossless compression of EEG signals

In this paper, we study compression techniques for electroencephalograph (EEG) signals. A variety of lossless compression techniques, including compress, gzip, bzip, shorten, and several predictive coding methods, are investigated and compared. The methods range from simple dictionary-based approaches to more sophisticated context modeling techniques. It is seen that compression ratios obtained by lossless compression are limited even with sophisticated context-based bias cancellation and activity-based conditional coding. Though lossy compression can yield significantly higher compression ratios while potentially preserving diagnostic accuracy, it is not usually employed due to legal concerns. Hence, we investigate a near-lossless compression technique that gives quantitative bounds on the errors introduced during compression. It is observed that such a technique gives significantly higher compression ratios (up to 3-bit/sample saving with less than 1% error). Compression results are reported for EEG's recorded under various clinical conditions.

Adaptive estimation of latency change in evoked potentials by direct least mean p-norm time-delay estimation

Evoked potentials (EP) have been widely used to quantify neurological system properties. Changes in EP latency may indicate impending neurological injury. Traditional EP analyses are developed under the condition that the background noise in EP analysis are Gaussian distributed. This paper proposes a latency change detection and estimation algorithm under alpha-stable noise condition, a generalization of Gaussian noise assumption. An analysis shows that the alpha-stable model fits the noises found in the impact acceleration experiment under study better than the Gaussian model. The robustness of the proposed algorithm is demonstrated through computer simulations and experimental data analysis under both Gaussian and alpha-stable noise environments.

Latency change estimation for evoked potentials via frequency selective adaptive phase spectrum analyzer

This paper addresses the problem of detecting and estimating latency changes in evoked potentials (EP's). EP's have been widely used to quantify neurological system properties. Transient and time-varying changes in latency may indicate impending neurological injury. Traditional time averaging and correlation methods for EP latency estimation are inefficient under low signal-to-noise ratio (SNR) and/or strong periodic interference conditions. This paper proposes an adaptive phase spectral time delay estimation method to detect and estimate the time-varying latency changes when both the SNR and the signal-to-interference ratio (SIR) are low. A theoretical analysis and computer simulation demonstrate that the proposed method can track the time-varying latency changes effectively and accurately when both the SNR and the SIR are as low as -5 dB. The method is also suitable for real time detection and estimation of the latency changes.

Quantification of injury-related EEG signal changes using distance measures

Novel indicators based on distance measures are developed and compared to quantify changes in electroencephalogram signal resulting from hypoxic-asphyxic injury. An injury index is derived based on the measures. The Itakura distance-based index is found to have the highest correlation with the long-term outcome as measured by the neurological deficit scores.

[Clinicopathologic study of 11 patients with Paget's disease of scrotum]

OBJECTIVE

To probe the relationship of clinicopathologic presentations and prognosis of Paget's disease primarily involving the scrotum.

METHODS

11 cases of scrotal Paget's disease were studied retrospectively from 1984 to 1997. PAS was stained and EMA, S-100, HMB45, CEA and CA15-3 were immunostained in all cases for the differential diagnosis from Bowen's disease and malignant melanoma.

RESULTS

Six of 11 cases involved hair follicle and/or sweat glands, and 3 cases involved dermis (one had metastasis of left superficial and deep inguinal lymph nodes, and left internal iliac lymph nodes). Paget's cells were positive for PAS (11/11), EMA (11/11), CEA (6/11), CA15-3 (11/11), and negative for S-100, HMB45. Wide local excision of the lesions was performed in 10 of 11 patients both for primary disease and recurrent disease. 3 of the 10 patients underwent lymph nodes resection and metastasis was found in 1 case pathologically. One patient accepted chemotherapy and died, from respiratory insufficiency after one month. The other 10 patients were followed up for 6 to 127 months and no patient died of Paget's disease.

CONCLUSIONS

Involvement of hair follicles and sweat glands by Paget's cell does not influence the prognosis.However, invasion of dermis by Paget's cells may suggest possible metastasis.

Flow cytometric analysis of BHRF1 expression prohibiting apoptosis induced by radiation

The Epstein-Barr virus gene BHRFI has homology with proto-oncogene bcl-2, which can protect cells from apoptosis. In order to investigate the effect of BHRF1 expression on the anti-apoptotic ability of nasopharyngeal carcinoma (NPC) cells after irradiation, a high-BHRF1 expression vector was constructed and transfected into the NPC cell line CNE2. Then, the alteration of proliferation and apoptosis in the cells was tested by flow cytometry after cobalt 60 irradiation. The results showed that BHRF1 expression could increase G1 delay and decrease the cell percentage in S phase before irradiation, and reduce the apoptotic rate of CNE2 cells and increase the cell percentage in S phase after irradiation. The results suggest that BHRF1 expression is able to alter the cell cycle and protect CNE2 cells from apoptosis induced by radiation.

Study of activity of promoter from mouse alpha 2(I) procollagen gene

OBJECTIVE

To clarify the segment and sequence in mouse alpha 2(I) procollagen gene which are responsible for high transcriptional activity during fibrogenesis.

METHODS

This study was focused on further fractional analysis of 2 kb-length mouse alpha 2(I) procollagen gene promoter activity. Six chimeric genes were constructed in which various lengths of sequences between 2000 bp upstream of the start of transcription of the mouse alpha 2 (I) procollagen gene and 54 bp downstream of this site were fused to chloramphenicol acetyltransferase (CAT) reporter gene. These recombinant plasmids were transfected transiently to collagen-producing cells (NIH/3T3) and non-collagen-producing cells (COS7) with liposomal transfection method. The activities of putative promoters were observed and compared by means of CAT measurement in the transfected cells.

RESULTS

The highest and partial cell specific CAT expression was observed in construction driven by -780 to bp fragment. The construction containing sequence deleted the proximal 500 bp from the transcription start site and part of exon I, and resulted in the lowest CAT expression.

CONCLUSIONS

Some essential elements might exist in the 500 bp fraction proximal to transcription start site and part of exon I in mouse alpha 2(I) procollagen gene. The high potential promoter sequence between -780 bp from the start of transcription site and bp from this site is of great significance in our following study of searching for specific DNA-binding proteins in activated collagen-producing cells.

A contiguous 3-Mb sequence-ready map in the S3-MX region on 21q22.2 based on high- throughput nonisotopic library screenings

Progress in complete genomic sequencing of human chromosome 21 relies on the construction of high-quality bacterial clone maps spanning large chromosomal regions. To achieve this goal, we have applied a strategy based on nonradioactive hybridizations to contig building. A contiguous sequence-ready map was constructed in the Down syndrome congenital heart disease (DS-CHD) region in 21q22.2, as a framework for large-scale genomic sequencing and positional candidate gene approach. Contig assembly was performed essentially by high throughput nonisotopic screenings of genomic libraries, prior to clone validation by (1) restriction digest fingerprinting, (2) STS analysis, (3) Southern hybridizations, and (4) FISH analysis. The contig contains a total of 50 STSs, of which 13 were newly isolated. A minimum tiling path (MTP) was subsequently defined that consists of 20 PACs, 2 BACs, and 5 cosmids covering 3 Mb between D21S3 and MX1. Gene distribution in the region includes 9 known genes (c21-LRP, WRB, SH3BGR, HMG14, PCP4, DSCAM, MX2, MX1, and TMPRSS2) and 14 new additional gene signatures consisting of cDNA selection products and ESTs. Forthcoming genomic sequence information will unravel the structural organization of potential candidate genes involved in specific features of Down syndrome pathogenesis.

[The effect of combined endocrine therapy on prostate and testis]

OBJECTIVE

To study the pathological changes of the effect of combined endocrine therapy on normal prostate, benign prostatic hyperplasia, prostatic adenocarcinoma and testis.

METHODS

11 radical prostatectomy specimens, 3 core-needle biopsies of prostate and 3 testes obtained after at least 3 months of enatone-flutamide inhibition therapy were studied. Step-section was performed on radical specimens and average 16 sections per case were reviewed. PSA, PSAP and AE1/AE3 were immunostained on 14 cases of prostate cancer and a comparative study pre- and post-treatment was made.

RESULTS

No residual tumor was recognized in 2 cases. Such characteristic changes were found in 9 cases as prominent acinar atrophy, decreased ratio of acini to stroma, stromal fibrosis, squamous metaplasia of carcinoma, cytoplasmic vaculation, nuclear shrinkage, and nucleolar shrinkage. No apparent change was discovered in 3 cases. Secretory epithelial atrophy and basal cell hyperplasia were the popular change in BPH and normal prostate. The expressions of both PSA and PSAP were markedly reduced in prostate carcinoma and nonneoplastic glands. Pathological downstaging of the tumor was not found statistically. Epithelial atrophy also existed in seminal vesicles and Leydig cells of the testes after hormone therapy.

CONCLUSIONS

Combined endocrine therapy results in histologically distinctive changes that can be found in both nonneoplastic and neoplastic prostate tissue. However, the drugs can not eradicate prostate cancer completely. Testis atrophy is the direct action of the therapy.

New axonemal dynein heavy chains from Tetrahymena thermophila

Two dyneins can be extracted from Tetrahymena ciliary axonemes. The 22S dynein contains three heavy chains (HC), sediments at 22S in a sucrose gradient, and makes up the outer arms. The 14S dynein contains two to six HCs, sediments at 14S, and is thought to contribute to formation of the inner arms. We have identified two large proteins that are extracted from Tetrahymena axonemes with high salt and that sediment together at approximately 18S. The two large proteins cleave when subjected to UV light in the presence of ATP and vanadate, suggesting both proteins are dynein HC. Antibodies against one of the 18S HCs do not recognize 22S dynein HCs. Antibodies to 22S dynein HC do not bind appreciably to 18S dynein photocleavage fragments. Taken together, these results indicate that the large proteins that sediment at 18S are axonemal dynein heavy chains.

[The influences of interleukin-1 beta converting enzyme expression on the biologic characteristics of ovarian cancer cells]

OBJECTIVE

To investigate the effects of interleukin-1 beta converting enzyme (ICE) gene on the biologic characteristics of ovarian cancer cells.

METHODS

A 1.3 Kilobase human ICE cDNA with 5' and 3' untranslated sequences was cloned into the EcoR I site of pLXSN retrovirus vector in sense orientation. After that, the recombinant plasmid pLXSN-ICE was transferred to virus-packing cell PA317 by electroporation method. And then the retrovirus containing human ICE cDNA generated by these PA317 cells were used to transfect human ovarian cancer cell lines, AO and 3AO.

RESULTS

After being transfected with these retrovirus, the number of the clones obtained after G418 resistance selection is far less than that of controlled groups with plasmid pLXSN. The growth rate of these transfected cells was significantly suppressed in comparison with the parental cell line. Apoptosis was also found in these cells. After the transfection cancer cells were inoculated subcutaneously in nude mice, the tumor growth was significantly inhibited.

CONCLUSION

It suggest that human ICE gene can suppress the phenotype and tumorigenicity in nude mice of ovarian cancer cell lines AO and 3AO.

Preliminary clinical application of contrast-enhanced MR portography

The clinical application of contrast enhanced (CE) MR was evaluated. A total of 66 CE MR portograms were obtained by performing fast imaging with steady procession (FISP) technique on a 1.5-T Siemens magnetom vision. A maximum intensity projection algorithm was also employed to include all vessels in a single image. The patency of portal venous system, the presence and extent of varices were also evaluated. The results showed that all images had diagnostic quality. Main portal vein (MPV) and its 4th-6th level intrahepatic branches were visualized in 10 normal persons serving as control. The diameter of MPV, splenic vein and superior mesenteric vein was 1.02 +/- 0.21, 0.8 +/- 0.15, 0.8 +/- 0.26 cm respectively, which were significantly lower than that in portal hypertension patients (1.38 +/- 0.27, 1.26 +/- 0.18, 1.24 +/- 0.18 cm, respectively). In 23 preoperative cases of portal hypertension, dilated portal vein and tortuous enlarged splenic vein were found in 23 cases; esophageal and coronary varices in 12 and 19 cases, respectively. In 7 postoperative re-examined cases with portal hypertension, the flow velocity and flow of MPV were decreased in all cases and esophageal varices could still be observed in 3 cases. New vessels appeared in the great curvature of stomach in 2 cases. In 20 cases of liver carcinoma, occlusion of MPV or its intrahepatic branches were showed in 14, compression and dislocation of intrahepatic portal vein were found in 6. In other 6 cases, 2 were splenic venous thrombosis and 4 were tumors in the intestine or retro-peritoneum. It is concluded that three-dimensional CE MR portography is an accurate technique for evaluating the portal venous system. It is a reliable and noninvasive technique that can provide important information for the evaluation of patients' condition before TIPSS and liver transplantation.

Gradient- and sensitivity-enhanced heteronuclear multiple-quantum correlation spectroscopy

A gradient- and sensitivity-enhanced HMQC experiment has been developed. The sensitivity of the experiment is increased by factors of the square root of 2 and 2 over the conventional and gradient-enhanced HMQC experiments, respectively. This improvement is achieved by retaining both the x and the y magnetization components in the indirectly detected dimension. This experiment will be particularly useful in NMR studies of large biomolecules as the relaxation time of the multiple-quantum coherence is much longer than that of the single-quantum coherence in the slow motion limit.

Structure of the E2 DNA-binding domain from human papillomavirus serotype 31 at 2.4 A

The papillomaviruses are a family of small double-stranded DNA viruses which exclusively infect epithelial cells and stimulate the proliferation of those cells. A key protein within the papillomavirus life-cycle is known as the E2 (Early 2) protein and is responsible for regulating viral transcription from all viral promoters as well as for replication of the papillomavirus genome in tandem with another protein known as E1. The E2 protein itself consists of three functional domains: an N-terminal trans-activation domain, a proline-rich linker, and a C-terminal DNA-binding domain. The first crystal structure of the human papillomavirus, serotype 31 (HPV-31), E2 DNA-binding domain has been determined at 2.4 A resolution. The HPV DNA-binding domain monomer consists of two beta-alpha-beta repeats of approximately equal length and is arranged as to have an anti-parallel beta-sheet flanked by the two alpha-helices. The monomers form the functional in vivo dimer by association of the beta-sheets of each monomer so as to form an eight-stranded anti-parallel beta-barrel at the center of the dimer, with the alpha-helices lining the outside of the barrel. The overall structure of HVP-31 E2 DNA-binding domain is similar to both the bovine papillomavirus E2-binding domain and the Epstein-Barr nuclear antigen-1 DNA-binding domain.

Regulation of classic and alternative bile acid synthesis in hypercholesterolemic rabbits: effects of cholesterol feeding and bile acid depletion

The effect of cholesterol feeding (3 g/day) on bile acid synthesis was examined in 10 New Zealand white rabbits (NZW), 8 Watanabe heterozygous and 10 homozygous rabbits with partial and complete deficiencies of LDL receptors. After 10 days of cholesterol feeding, bile fistulas were constructed and bile acid pool sizes were measured. Cholesterol feeding increased plasma and hepatic cholesterol levels in all rabbit groups. Baseline bile acid pool sizes were smaller (P < 0.01) in heterozygotes (139 +/- 3 mg) and homozygotes (124 +/- 30 mg) than NZW rabbits (254 +/- 44 mg). After feeding cholesterol, bile acid pool sizes doubled with increased cholic acid synthesis in NZW and, to a lesser extent, in Watanabe heterozygous rabbits but not in homozygotes. Baseline cholesterol 7alpha-hydroxylase activity in NZW and heterozygotes declined 69% and 53% (P < 0.001), respectively, after cholesterol feeding. Sterol 27-hydroxylase activity reflecting alternative bile acid synthesis increased 66% (P < 0.01) in NZW and 37% in Watanabe heterozygotes but not in homozygotes after feeding cholesterol. Bile fistula drainage stimulated cholesterol 7alpha-hydroxylase activity but not sterol 27-hydroxylase activity in all three rabbit groups. These results demonstrated that dietary cholesterol increased hepatic sterol 27-hydroxylase activity and alternative bile acid synthesis to expand the bile acid pool and inhibited cholesterol 7alpha-hydroxylase in NZW and in Watanabe heterozygous rabbits but not in homozygotes with absent hepatic LDL receptor function. Thus, in rabbits, sterol 27-hydroxylase is up-regulated by the increased hepatic cholesterol that enters the liver via LDL receptors whereas cholesterol 7alpha-hydroxylase is controlled by the circulating hepatic bile acid flux.

[Effects of ligustrazine on myocardium and coronary artery]

OBJECTIVE

To study the effects of ligustrazine on mechanical electricity in guinea pig ventricular papillary muscles and on contraction of pig coronary artery.

METHOD

Standard glass microelectrode technology; electrophysiological method; and blood vessel perfusion were used.

RESULT

1. ligustrazine(3-100 mumol/L) suppressed the action potential duration (APD) and the force of contraction (FC) of the fast action potentials (FAP), as well as the action potential amplitude (APA), APD, FC and the maximal upstroke velocity(Vmax) of the slow action potentials (SAP). 2. ligustrazine (3.0 mmol/L) induced SAP and contraction, but failed in beta-adrenoreceptor blocked muscles. Elevation of[Ca2+]o increased the action potential amplitude (APA). 3. ligustrazine(10(-5)-5 x 10(-3) mol/L) decreased the contractile response to high KCl in pig coronary artery.

CONCLUSION

Ligustrazine might affect the inward current of myocardial cells through beta-adrenoreceptor, and the diastolizing effect of ligustrazine on coronary artery might have nothing to do with the exciting beta-adrenoreceptor.

[Expression and significance of Fas/APO-1 and bcl-2 protein in renal cell carcinoma]

OBJECTIVE

To investigate the role of Fas/APO-1 and bcl-2 in occurrence and progression of renal cell carcinoma.

METHOD

Immunohistochemistry method was used to detect the expression of Fas/APO-1 and bcl-2 protein in 35 cases of renal cell carcinoma tissues and 26 cases of normal renal tissues.

RESULT

The expression rate of Fas/APO-1 protein in renal cell carcinoma tissues was 57.14%, significantly lower than that in normal renal tissues (84.62%) (P < 0.05), and the intensity of expression was also lower. The expression rate of bcl-2 protein reached 80.00%, much higher than that in normal renal tissues (53.85%) (P < 0.05).

CONCLUSION

Both Fas/APO-1 and bcl-2 take part in the occurrence and progression of renal cell carcinoma.

[Effects of excessive zinc in fodder on brain development and abilities of learning and memory and their mechanisms in young rats]

OBJECTIVE

To study the effects of excessive zinc in fodder on brain development and abilities of learning and memory and to explore their mechanisms in young rats.

METHODS

Animal models with excessive zinc were established in young Wistar rats during their lactation period. Rats were divided into five groups, Groups ZE1 and ZE2 were fed with excessive zinc, Group AL was freely fed with Flanagna fomula fodder added with zinc sulfate, Group PF was matched pair of Group ZE2 and Group ZE2R was fed with fodder same as Group AL after weaning. Ultrastructure was observed with electron microscopy, their free amino acids, nitrous oxide and somatostatin were measured with neurobiochemical methods, and their abilities to learn and memorize were examined.

RESULTS

Weight of cerebrum and hippocampus in the rats reduced and zinc levels in their serum and hippocampus raised with the increase of zinc content in their fodder. Acute avoidance response (AAR) and movement in the young rats fed with excessive zinc in Groups ZE1 and ZE2 were obviously lower than in Groups AL and PF. AAR was significantly lower in Group ZE2R than that in Groups AL and PF, but significantly higher than that in Group ZE2. There was no significant difference in AAR between Groups PF and AL, but more movement was observed in them. Nitrous oxide in hippocampus raised and somatostatin decreased in Group ZE2, and total amount of excitatory and inhibitory amino acids in brain tissues raised, especially for glutamic acid. Neurones, gliocytes and organella in the CA1 region of hippocampus in the Group ZE2 showed degeneration, necrosis and rupture of synaptic bolus to varied extent.

CONCLUSION

Excessive zinc in fodder could significantly affect brain development and functions in young rats with multiple mechanisms.

[Apoptosis of renal cell carcinoma and apoptotic related genes bcl-2 and bax]

OBJECTIVE

To explore the mechanism of renal cell carcinoma (RCC).

METHOD

We detected the apoptotic status and the expression of apoptotic related gene bcl-2 and bax protein in 48 cases of RCC with TdT-mediated dUTP-biotin nick end labeling (TUNEL) and immunohistochemistry methods.

RESULT

22 cases showed low expression of bcl-2 protein with an average apoptotic index (AI) of 1.35 and 26 cases had high expression of bcl-2 with an AI of 1.04 (P < 0.05). 34 cases showed low expression of bax protein with average AI of 1.03 and 14 cases had high expression of bax protein with an average AI of 1.63 (P < 0.01). The stronger bcl-2 expression, the weaker bax expression and the less number of apoptotic cells.

CONCLUSION

both bcl-2 and bax take part in the occurrence and progression of RCC.

[Primary epididymal tumors]

OBJECTIVE

To improve the diagnosis of primary epididymal tumors.

METHOD

In 23 primary epididymal tumors (22 benign and 1 malignant), 14 were adenomatoid tumors, 6 were leiomyomas, 1 was multiple fibrous pseudomonas and 1 was sclerosing hemangioma. Epididymal adenocarcinoma was seen in a 57-year-old man.

RESULT

Epididymal tumors might be easily misdiagnosed as epididymal tuberculosis, chronic epididymis and spermatocele. Apart from certain benign clinical characteristics, benign epididymal tumors could be diagnosed by B-ultrasonography and aspiration biopsy. Most malignant tumors of epididymis presented as rapidly growing scrotal masses and cured by the removal of tumors or the whole epididymis of the same side. 19 of 22 cases were free from recurrence.

CONCLUSION

Malignant epididymal tumors should be treated as malignant tumors of testis and their prognosis is extremely poor.

[Low semi-cystectomy in treating trigone of bladder neck carcinoma]

OBJECTIVE

To resect the tumor in trigone and bladder neck and remain urination function.

METHOD

A new procedure low segmental-cystectomy which includes resection of the trigone of bladder, prostate, seminal vesicles, extremity of ureter, was performed on 8 patients aged 28 to 57 years.

RESULT

The patients were followed up for 6 months to 3 years. No recurrent tumor and metastasis were found, and urination function was normal.

CONCLUSION

This procedure is superior to Bricker's operation, Kock pouch bladder and ileal neo-bladder. The patients enjoy good life quality after operation.

Identification of conserved amino acids in murine B7-1IgV domain critical for CTLA4/CD28:B7 interaction by site-directed mutagenesis: a novel structural model of the binding site

The B7: CD28/CTLA4 interaction plays a major role in T cell responses. Immune intervention targeted at this interaction has demonstrated a vast potential in enhancing tumor immunity and blocking autoimmunity and transplant rejection. However, the structural basis for this interaction is unclear. While we and others have performed site-directed mutagenesis to define amino acids involved in binding CD28 and CTLA4, these residues are localized in different regions, and it is unlikely for all of them to be directly involved. In addition, the effect of the mutations on the overall conformation of B7 has not been systematically evaluated. In this study, we have carried out site-directed mutagenesis to define the amino acids within B7-1 IgV-like domain which participate B7:CD28/CTLA4 interaction. Four anti-B7-1 mAbs that recognize three independent antigenic epitopes on B7-1 were used to monitor the effect of mutations on the overall conformation of B7-1. Of the five mutations in the IgV domain that we have produced, D113 > A appears to interfere with cell surface expression and/or overall conformation of B7-1. while four others do not significantly affect the overall conformation and cell surface expression of B7-1. Among them, G115 > A and Y91 > A eliminated B7-1 binding to both CD28Ig and CTLA4Ig; our previously reported mutants L109 > A and W88 > A selectively affect the B7-1 binding to either CD28Ig or CTLA4Ig. Structural modeling of B7-1 based on the structure of immunoglobulin revealed that these four and other previously identified critical amino acids in both IgV- and IgC-like domains can form a localized structure.

[The study of radioresistance of BHRF1 gene]

In order to learn relationship between the expression of BHRF1 gene and radiative sensitivity of cells of nasopharyngeal carcinoma. High BHRF1 expressive vector was set up and transfected in the cell line of nasopharyngeal carcinoma, CNE2. Then the cells were radiated to test its ability of clone formation in nude mice. The results showed that the tumors formed by BHRF1-CNE2 cells were lighter before radiation and weighter after radiation (P < 0.01), and apoptotic index of BHRF1-CHE2 was less than control groups (P < 0.01). So, it suggests that the BHRF1 expression could prevent apoptosis by enhancing the resistibility of the tumor cells to radiation.

Nucleotide sequence homology to bovine viral diarrhea virus 2 (BVDV 2) in the 5' untranslated region of BVDVs from cattle with mucosal disease or persistent infection in Japan

Cytopathogenic and non-cytopathogenic bovine viral diarrhea viruses (BVDVs) were isolated from cattle with mucosal disease or persistent infection in Japan. These isolates were compared for antigenic properties by cross-neutralization tests with Japanese reference strains of BVDV belonging to classical type 1. Significantly low cross-reactivity to reference strains was noted, indicating the viruses to possibly represent a new serotype in Japan. Thus, to determine the genotype of the isolates, nucleotide sequences of the 5' untranslated region were determined and compared with those of previously reported BVDV 1 and 2. The isolates were clearly shown to belong to BVDV 2, not to BVDV 1.

[Multilocular cyst of kidney]

OBJECTIVE

Multilocular cyst of kidney is a rare, unique and characteristic renal lesion with benign biologic behavior. We report a case of the disease.

METHODS

It was confirmed by operation and pathology.

RESULTS

It is difficult to distinguish radiologically multilocular cyst of kidney from cystic renal carcinoma and wilms tumor.

CONCLUSION

Surgical intervention is the only effective treatment and method to differentiate multilocular cyst of kidney from a malignant lesion of the kidney.

An adenosine deaminase (ADA) allele contains two newly identified deleterious mutations (Y97C and L106V) that interact to abolish enzyme activity

Genetic deficiency of the purine salvage enzyme adenosine deaminase (ADA) results in varying degrees of immunodeficiency, ranging from neonatal onset Severe Combined Immunodeficiency (SCID) to an adult onset immunodeficiency disorder. Multiple different mutations have now been identified in these immunodeficient patients. Additional mutations, initially identified in healthy individuals, abolish ADA in erythrocytes but retain 10-80% of activity in non-erythroid cells ('partial deficiency mutations'). In general, severity of disease correlates inversely with the amount of residual ADA expressed by the mutant enzymes and directly with the accumulation of the toxic metabolites deoxyATP and deoxyadenosine. We report two newly identified mutations (Y97C and L106V), both carried on the same allele of an immunodeficient patient who was diagnosed prenatally and successfully transplanted with haploidentical bone marrow. Based on the ability of mutant cDNAs to express ADA in vitro , the L106V mutation resulted in activity similar to 'partial' mutations (30% of normal) while the Y97C mutation resulted in detectable but markedly reduced activity (1.5% of normal). However, the presence of both mutations on the same allele virtually abolished detectable enzyme activity. Analysis of the crystallographic structure of ADA to understand the marked deleterious effect of the Y97C mutation suggested a previously unappreciated role of salt bridges in the catalytic mechanism of ADA. The patient was also heteroallelic for a previously described deletion of the promoter and exon 1. Testing of additional patients in whom we had not identified a mutation on the second allele revealed presence of this deletion in three of four patients tested. This deletion is therefore relatively common, accounting for 10% of almost 100 chromosomes studied by this and other laboratories, but is easily missed by currently used methods of mutation detection. Lastly, the finding of two mutations on the same allele that interact to reduce residual enzyme function emphasizes hazards in evaluating potential genotype-phenotype correlations in individuals analyzed only for the presence of single specific mutations.