[Clinical analysis of 9 cases with Anti-leucine-rich glioma inactivated 1 protein antibody associated limbic encephalitis]

Objective: This study was to describe the clinical characteristics of Anti-leucine-rich glioma inactivated 1 protein(LGI1) antibody associated limbic encephalitis. Methods: Clinical data including clinical features, laboratory and radiological findings, treatment and prognosis of the 9 patients were analyzed. Results: In all 9 cases, 6 cases experienced epileptic seizure, 5 cases had psychosis, 7 cases presented with memory impairment, 4 cases showed faciobrachial dystonic seizure, 2 had refractory hyponatremia. One case presented with typically acute Guillain-Barre syndrome (GBS). Anti-LGI1 antibody was detected in 6 cases in cerebrospinal fluid (CSF) samples and 9 in serum samples. Seven cases out of 9 had brain imaging abnormalities. All 9 cases found no evidence of tumors. Eight cases were given immune therapy. During a 1-16 months follow-up, 1 case had complete recovery, 5cases had various degree of sequelae , among whom 4 had memory disturbance and 1 case had changed personality. 2cases were lost to follow-up. Conclusions: Limbic encephalitis is the most common manifestation of anti-LGI1 antibody associated encephalitis. Faciobrachial dystonic seizure (FBDS) is a specific symptom which favors an early diagnosis. Tumor is uncommon to see. The disease has a relatively favorable prognosis while impaired memory can be seen as a common sequelae.

[Association between single nucleotide polymorphism of adenylyl cyclase 3 and essential hypertension]

OBJECTIVE

To explore the association between the tag single nucleotide polymorphism (tag SNP) of the adenylyl cyclase 3 (ADCY3) and the essential hypertension (EH).

METHODS

From April to July 2013, a total of 1 061 subjects diagnosed with EH and 1 218 control subjects were recruited from Ningbo, Zhejiang Province. Information was collected by face-to-face interview. Twelve tag SNPs were detected by ligase detection reaction technique.

RESULTS

After adjusted for age, gender, body mass index and other related factors, logistic regression analysis showed that 3 loci (rs11689546, rs7593130, rs2241759)were associated with EH. AG genotype of rs11689546 was associated with 0.494 times lower risk of EH (OR=0.494, 95%CI 0.246-0.993; compared with AA genotype). CT genotype of rs7593130 was associated with 1.596 times higher risk of EH (OR=1.596, 95%CI 1.009-2.524; compared with TT genotype), and CT/CC genotype of rs7593130 was associated with 1.627 times higher risk of EH (OR=1.627, 95%CI 1.034-2.559; compared with TT genotype). AG genotype of rs2241759 was associated with 0.669 times lower risk of EH (OR=0.669, 95%CI 0.503-0.891; compared with AA genotype), and CT/CC genotype of rs2241759 was associated with 0.687 times lower risk of EH (OR=0.687, 95%CI 0.518-0.911; compared with TT genotype).

CONCLUSION

The polymorphisms of ADCY3 are associated with lower (G allele of the rs11689546 locus and G allele of the rs2241759 locus) or higher (C allele of the rs7593130 locus) risk of essential hypertension.

[Clinical effect of minimally-Invasive surgical-transforaminal lumbar interbody fusion technique associated with percutaneous pedicle screws in micro endoscopy discectomy]

Objective: To evaluate the clinical efficacy between the minimally-Invasive surgical (MIS)-transforaminal lumbar interbody fusion (TLIF) technique associated with percutaneous pedicle screws in micro endoscopy discectomyand MIS-TLIF technique associated with both sides of the lower lumbar spine Wiltse approach in Quadrant channel with treatment of single segment herniation associated with lumbar instability syndrome. Methods: From January 2012 to January 2015, 75 cases that meet the inclusion and exclusion criteria were treated by retrospective study method, which were divided into two groups in Department of Orthopedics, the Affiliated Hospital of Putian University.Experimental group(30 patients) were treated with MIS-TLIF technique associated with percutaneous pedicle screws in microendoscopy discectomy, control group were treated with MIS-TLIF technique associated with both sides of the lower lumbar spine Wiltse approach in Quadrant Chanel.Compare operation time, blood loss, postoperativehospital stay, clinical efficacy, nailing accuracy, fusion rate, postoperative pain scoring of two groups. Results: The blood loss[(102.1±5.5) min vs(103.7±7.7) min, t=-0.586, P>0.05], postoperative blood loss, hospital stay[(44.6±5.2) ml and(57.2±5.3) ml, (7.3±1.6) d and(9.3±1.9) d; t=-5.813, -2.774, P<0.05], JOA score before and after surgery in same group were statistically significant(P<0.05), respectively.Patients of two groups compared with operation time, clinical efficacy, nailing accuracy[group A: 97.5%, group B: 95.7%; χ(2)=3.00, P>0.05.Postoperative 3 month , group A: 96.7%(29/30), group B: 94.3%(33/35; χ(2)=0.79, P>0.05], fusion rate[group A: 96.7%(29/30), group B: 94.3%(33/35), χ(2)=0.79, P>0.05], preoperative JOA score[(20.4±2.4)score and(7.9±1.0), (19.1±2.7)score and(7.8±1.2)score], postoperative JOA score were no statistically significant respectively, P>0.05. JOA score of both groups were statistically significant respectively Before and after operate.Excellent rate: group A; 84.4%(25/30), group B: 80.0%(28/35), χ(2)=0.43, P>0.05. Conclusion: MIS-TLIF technique associated with percutaneous pedicle screws in micro endoscopy discectomy relative to conventional minimally invasive spine surgery had many advantages: minimal damage, operation conveniently, precisely clinical effect, that is a kind of feasible and reliable minimally invasive surgery which is worth promoting.

NMR investigation of magnesium chelation and cation-induced signal shift effect of testosterone

We have previously reported that testosterone (Tes) is able to interact with magnesium chloride dissolved in methanol. In this study, we have applied ¹H and ¹³C NMR spectroscopies to a series of Tes solutions containing Mg²⁺ at various concentrations. High-resolution ¹³C NMR spectra of Tes/Mg²⁺ revealed well-resolved ¹³C signals, and the intensities of those arising from C3, C5, C16, and C17 decreased linearly with increasing Mg²⁺ concentration. The magnitude of the chelation affinity could be deduced from the slopes of the ¹³C intensity variations; typically, the greater the slope the higher the chelation affinity. The results revealed Tes/Mg²⁺ chelation to be mediated by the oxygen atom attached to C3 in ring A, and the hydroxyl group attached to C17 in ring D. With regard to the chelation specificity, we showed that Tes chelates Mg²⁺, but not Ca²⁺ or Zn²⁺. We also explored the cation-induced signal shift effects of Tes in the presence of Mg²⁺, Ca²⁺, or Zn²⁺. We demonstrate that high-resolution ¹³C NMR spectroscopy provides a better probe than ¹H NMR for the detection of cation chelation and cation-induced signal shift effects for steroid compounds such as Tes.

A novel Al matrix composite reinforced by nano-AlNp network

In pursuit of lightweighting of automobiles and low emission of transportation, the efforts to develop high-strength, heat-resistant and fatigue-resistant Al alloys and/or composites have been ongoing. Here we report a novel Al matrix composite with ultrahigh strength reinforced by a three dimensional network of nano-AlN particles for the first time. The in-situ synthesized AlN particles are connected by twinning bonding chains and built up a three dimensional network strengthening Al matrix enormously like the skeleton to human body. The composite containing 16.4wt.% AlN particles shows excellent properties: the ultimate tensile strengths can be up to 518MPa at room temperature and 190MPa at 350 °C. This peculiar performance results from the novel spatial distribution of nano-scale AlN particles. Our findings in this work would help to develop a potential candidate for high-performance heat resistance light-metal based materials.

[Feasibility study of transplantation of penile corpus cavernosum and major pelvic ganglion in renal subserous region]

OBJECTIVE

To study the feasibility of transplantation of normal rat penile corpus cavernosum and major pelvic ganglion (MPG) into the renal subserous region of a Nu/Nu mouse based on allograft technology.

METHODS

Penile corpus cavernosum and MPG, harvested from Sprague-Dawley (SD) rats under sterile condition, were transplanted underneath the kidney capsule of Nu/Nu mice through the microsurgery instruments and surgery microscope. The histopathologic changes and cellular proliferation in the transplanted penile corpus cavernosum and MPG were then analyzed at the end of 1week and 4 weeks after transplantation. Histological staining and immunohistochemical staining were used to evaluate the main outcome measures.

RESULTS

After 1 week, the tissue morphology of the transplanted corpus cavernosum underneath the kidney capsule of Nu/Nu mice was consistent with normal penile corpus cavernosum, and blood could be observed in the penis cavernous sinus of the graft; after 4 weeks, the mophorlogy of the tranplanted corpus cavernosum near the kidney was consistent with normal penile corpus cavernosum, while fibrosis was noteworthy in the graft away from the kidney, but blood could still be seen in the penis cavernous sinus. After 1 week, the tissue morphology of the transplanted MPG was consistent with normal MPG, multiple islet-like cell clusters could be seen in the transplanted MPG in the renal subserous region, and angiogenesis could be observed near the kidney; after 4 weeks, a network of blood vessels was clearly visible away from the kidney, and islet-like cell clusters were still clearly observed in the transplanted MPG. In addition, ki67 positive cells were observed in the transplanted penile corpus cavernosum and MPG after 4 weeks of transplantation, which indicated that there was still cell proliferation activity in the grafts.

CONCLUSION

The transplanted corpus cavernosum and MPG underneath the kidney capsule of Nu/Nu mice could survive at least 4 weeks. Moreover, the inner structure of the transplanted corpus cavernosum and MPG was close to the normal tissue. The underlining mechanism may be related to the local microenvironment underneath the kidney capsule of Nu/Nu mice and the neovascularization in the transplanted grafts.

Population structure analysis and association mapping of blast resistance in indica rice (Oryza sativa L.) landraces

Rice blast caused by Magnaporthe oryzae is one of the most devastating rice diseases worldwide. To understand the genetic diversity of indica landrace accessions and identify simple sequence repeat (SSR) markers that are associated with blast resistance, a population of 276 indica landraces from across the world was constructed. This population was then used to evaluate the blast-resistance phenotype through artificial inoculation under controlled conditions in 2012 and 2013. The genetic diversity and association of the population with resistance were analyzed by examining the phenotype for 160 SSR markers distributed on 12 rice chromosomes. The 276 accessions were classified into seven groups using model- and distance-based cluster analyses. Associations between SSR markers and blast resistance showed that 26 SSR markers were significantly associated with blast resistance in 2012 and 2013 (P < 0.01) and that the phenotypic variation ranged from 2.68 to 13.11%. Nineteen of the markers associated with blast resistance were located in regions where genes or quantitative trait loci (QTLs) have been previously reported, and seven were newly identified in this study. These results indicate that marker-trait association has potential advantages over classical linkage analysis and QTL mapping, and that these markers could be used for marker-assisted selection in rice blast-resistance-breeding programs.

Analysis of genetic diversity and population structure in a tomato (Solanum lycopersicum L.) germplasm collection based on single nucleotide polymorphism markers

Knowledge of genetic diversity is important to assist breeders in the selection of parental materials and in the design of breeding programs. In this study, we genotyped 348 inbred tomato lines, representing vintage and contemporary fresh-market varieties, by using 52 single nucleotide polymorphisms (SNPs); 45 of these were found to be polymorphic. The average minor allele frequency and unbiased expected heterozygosity were 0.315 and 0.356, respectively. Population structure analysis revealed that contemporary germplasm could be distinctly divided into six subpopulations representing three market classes and breeding programs (pink, green, and red). Vintage germplasm could be separated into at least two subpopulations, and more admixtures were found in vintage lines than in contemporary lines. These findings indicate that contemporary inbred lines are more diversified than vintage inbred lines. AMOVA of vintage and contemporary lines was performed. A significant difference was found (P < 0.01), which explained 17.4% of the total genetic variance. Subsequently, we constructed a core collection using 45 polymorphic SNP markers. The data showed that all alleles were captured by only 2% of lines, indicating that more alleles, as well as rare alleles, could enable more variation to be captured in the core collection. These data allow us to discard redundant inbred tomato lines and to select elite inbred lines, which will accelerate the breeding process.

[Correlation of occupational stress with serum levels of immunoglobulins and complement in police]

OBJECTIVE

To investigate the correlation of occupational stress with the serum levels of immunoglobulins(IgG, IgM, and IgA) and complement(C3 and C4).

METHODS

In May 2011, convenience sampling and cluster sampling were used to select 225 policemen from a local police station as study subjects. A questionnaire was used to investigate demographic features and occupational stress, and the immunoturbidimetric assay was applied to measure the serum levels of IgG, IgM, IgA, and complement C3 and C4.

RESULTS

Positive affectivity was positively correlated with the concentration of IgG(r=0.084, P<0.01); positive affectivity, coping strategy, and sleep quality were positively correlated with the concentration of IgM(r= 0.146, 0.155, and 0.203, all P<0.05); negative affectivity was negatively correlated with the concentration of IgM(r=-0.185, P<0.05). Reward and sleep quality were positively correlated with the concentration of C3(r= 0.172 and 0.285, both P<0.05), and negative affectivity was negatively correlated with the concentration of C3 (r=-0.174, P<0.05); sleep quality was positively correlated with the concentration of C4(r= 0.173, P<0.05), and negative affectivity was negatively correlated with the concentration of C4(r=-0.164, P<0.05). The logistic regression analysis revealed that the risks for a reduced concentration of IgG in the groups with high scores of social support and positive affectivity were 0.460 and 0.495 times those in the groups with low scores, while the risk for a reduced concentration of IgM in the group with a high score of coping strategy was 0.482 times that in the group with a low score.

CONCLUSION

Occupational stress is correlated with the serum levels of immunoglobulins and complement.

[Feasibility study of transplantation of penile corpus cavernosum and major pelvic ganglion in renal subserous region]

OBJECTIVE

To study the feasibility of transplantation of normal rat penile corpus cavernosum and major pelvic ganglion (MPG) into the renal subserous region of a Nu/Nu mouse based on allograft technology.

METHODS

Penile corpus cavernosum and MPG, harvested from Sprague-Dawley (SD) rats under sterile condition, were transplanted underneath the kidney capsule of Nu/Nu mice through the microsurgery instruments and surgery microscope. The histopathologic changes and cellular proliferation in the transplanted penile corpus cavernosum and MPG were then analyzed at the end of 1week and 4 weeks after transplantation. Histological staining and immunohistochemical staining were used to evaluate the main outcome measures.

RESULTS

After 1 week, the tissue morphology of the transplanted corpus cavernosum underneath the kidney capsule of Nu/Nu mice was consistent with normal penile corpus cavernosum, and blood could be observed in the penis cavernous sinus of the graft; after 4 weeks, the mophorlogy of the tranplanted corpus cavernosum near the kidney was consistent with normal penile corpus cavernosum, while fibrosis was noteworthy in the graft away from the kidney, but blood could still be seen in the penis cavernous sinus. After 1 week, the tissue morphology of the transplanted MPG was consistent with normal MPG, multiple islet-like cell clusters could be seen in the transplanted MPG in the renal subserous region, and angiogenesis could be observed near the kidney; after 4 weeks, a network of blood vessels was clearly visible away from the kidney, and islet-like cell clusters were still clearly observed in the transplanted MPG. In addition, ki67 positive cells were observed in the transplanted penile corpus cavernosum and MPG after 4 weeks of transplantation, which indicated that there was still cell proliferation activity in the grafts.

CONCLUSION

The transplanted corpus cavernosum and MPG underneath the kidney capsule of Nu/Nu mice could survive at least 4 weeks. Moreover, the inner structure of the transplanted corpus cavernosum and MPG was close to the normal tissue. The underlining mechanism may be related to the local microenvironment underneath the kidney capsule of Nu/Nu mice and the neovascularization in the transplanted grafts.

Dihydromyricetin induces cell apoptosis via a p53-related pathway in AGS human gastric cancer cells

The aim of the present study was to determine the anti-proliferative and pro-apoptotic effects of dihydromyricetin (DHM) on the AGS human gastric cancer cells and their underlying mechanisms. The effects of DHM on AGS cells were evaluated by using 3-(4, 5-di-methylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), lactate dehydrogenase, and Annexin V/propidium iodide (PI) double-staining assays. The underlying mechanisms were determined by using quantitative real-time polymerase chain reaction. The results demonstrated that DHM significantly (P < 0.05) inhibited AGS cell proliferation and induced cell cytotoxicity in a dose- and time-dependent manner. Additionally, Annexin V/PI double-staining assay showed that DHM promoted cell apoptosis in both, early and late stages. Furthermore, DHM also regulated the expression of apoptotic genes such as p53 and B-cell lymphoma-2 (bcl-2) in a dose- and time-dependent manner. In conclusion, this is the first report demonstrating the anticancer and pro-apoptosis effects of DHM on AGS human gastric cancer cells. The results strongly suggest that DHM may be a potential therapeutic candidate for the treatment of gastric cancer.

miR-71b regulation of insulin/IGF-1 signaling during starvation in planarians

Planarians, which have a large population of stem cells called neoblasts, are molecularly tractable model systems used in the study of regeneration. However, planarians have strong resistance to hunger and have developed growth arrest strategies. For example, they can change their size and undergo growth regression during starvation periods. The results of the current study show that the microRNA, miR-71b, and the insulin/IGF-1 signaling pathway have important functions in the development of starvation-induced planarians. We demonstrate tissue-specific expression of miR-71b using in situ hybridization. By employing real-time polymerase chain reaction, we provide evidence that miR-71b is upregulated in starvation-induced planarians. Furthermore, we validate and verify the target genes of miR-71b.

Allergy in Hong Kong: an unmet need in service provision and training

Many children in Hong Kong have allergic diseases and epidemiological data support a rising trend. Only a minority of children will grow out of their allergic diseases, so the heavy clinical burden will persist into adulthood. In an otherwise high-quality health care landscape in Hong Kong, allergy services and training are a seriously unmet need. There is one allergy specialist for 1.5 million people, which is low not only compared with international figures, but also compared with most other specialties in Hong Kong. The ratio of paediatric and adult allergists per person is around 1:460 000 and 1:2.8 million, respectively, so there is a severe lack of adult allergists, while the paediatric allergists only spend a fraction of their time working with allergy. There are no allergists and no dedicated allergy services in adult medicine in public hospitals. Laboratory support for allergy and immunology is not comprehensive and there is only one laboratory in the public sector supervised by accredited immunologists. These findings clearly have profound implications for the profession and the community of Hong Kong and should be remedied without delay. Key recommendations are proposed that could help bridge the gaps, including the creation of two new pilot allergy centres in a hub-and-spoke model in the public sector. This could require recruitment of specialists from overseas to develop the process if there are no accredited allergy specialists in Hong Kong who could fulfil this role.

Identification of quantitative trait loci conferring blast resistance in Bodao, a japonica rice landrace

Bodao, a japonica landrace from the Taihu Lake region of China, is highly resistant to most Chinese isolates of Magnaporthe oryzea, a form of rice blast. To effectively dissect the influence of genetics on this blast resistance, a population of 155 recombinant inbred lines (F2:8) derived from a cross of Bodao x Suyunuo was inoculated with 12 blast isolates. Using a quantitative trait locus (QTL) mapping approach, 13 QTL on chromosomes 1, 2, 9, 11, and 12 were detected from Bodao. Five QTL, including qtl11-1-1, qtl11-3-7, qtl11-4-9, qtl12-1-1, and qtl12-2-3, have not been previously reported. The qtl11-3-7 and qtl11-4-9 may be the two main effective QTL and resistant to 7 and 9 isolates, respectively. The results of the present study will be valuable for the fine mapping and cloning of these two new resistance genes.

Promoter hypomethylation and increased maspin expression in preeclamptic placentas in a Chinese population

OBJECTIVE

Preeclampsia is thought to begin with shallow trophoblast invasion and inadequate spiral artery remodeling. Maspin, a tumor-suppressor gene, plays a regulatory role in trophoblast invasion and motility. The tissue-specific methylation of the maspin promoter can regulate maspin gene expression in various cancers. We sought to detect maspin gene expression and assess the degrees of methylation of maspin promoter regions in preeclamptic placentas in the Han Chinese population and to investigate the potential role of maspin in the pathophysiology of preeclampsia.

METHODS

We conducted RT-PCR, immunohistochemistry and western blotting to characterize maspin gene expression and protein levels in the placentas from normal and preeclamptic pregnancies. Finally, using methylation-specific PCR and bisulfite sequencing PCR, we detected the degrees of methylation of the promoter regions of maspin in each of the two studied groups.

RESULTS

Maspin expression was increased at the mRNA and protein levels in the preeclamptic placentas compared to the control group. Maspin immunohistochemical staining revealed positive staining in the syncytio-cytotrophoblast layers and more diffuse staining in the preeclamptic group. The mean methylation level of the analyzed promoter region was significantly hypomethylated in the preeclamptic placentas compared to the control placentas, pointing to a negative relationship between maspin promoter methylation and gene expression.

DISCUSSION

Hypomethylation of the maspin promoter results in increased expression of maspin in preeclamptic placentas, which suggests a negative relationship between maspin methylation and maspin expression in this Han Chinese population. Thus, maspin is likely involved in the etiology of preeclampsia.

Effects of fluoride and chloride on the growth of Chlorella pyrenoidosa

To compare the toxic action of fluoride (F(-)) and chloride (Cl(-)) on freshwater algae, effects of F(-) and Cl(-) on Chlorella pyrenoidosa growth were investigated by determination of the algal biomass and model analysis. Results showed that the exponential growth equation (D = D0 + ae(bT)) may be used to fit the relationship between cell density (D) of C. pyrenoidosa and exposure time (T), but F(-) and Cl(-) have significantly different effects on parameters a (initial quantity of algae at the exponential growth stage) and b (growth constant). In the range of experimental concentrations, F(-) inhibited C. pyrenoidosa growth, and percent inhibition increased with increasing exposure time and F(-) concentration. By contrast, Cl(-) either inhibited or enhanced C. pyrenoidosa growth depending on Cl(-) concentration and exposure time, and percent inhibition increased with increasing Cl(-) concentration but decreased with increasing exposure time. The dose-response equation: I = min + (max - min)/(1 + 10(lgEC50-lgC)) may be used to fit the relationship between percent inhibition (I) and F(-) or Cl(-) concentration (C); however, F(-) was distinct from Cl(-) in terms of effects on parameter 'min'. The EC50 values of F(-) and Cl(-) ranged from 118 to 170 mg/L and 19.73 to 36.33 g/L, respectively; the latter is much higher than the former. Thus F(-) has higher toxicity than Cl(-).

Comparison of the efficacy and complications of different surgical methods for cervical intraepithelial neoplasia

OBJECTIVE

The aim of this was study to offer some reference for the treatment of cervical intraepithelial neoplasia (CIN) by comparing complication rates and treatment failure rates of different surgical methods of CIN.

METHODS

1,256 cases of CIN diagnosed by punch biopsy and pathological confirmation of postoperative specimens between January 2002 and June 2007 were reviewed and analyzed, in which 74 cases underwent the loop electrosurgical excision procedure (LEEP), 869 patients adopted cold knife conization (CKC), 49 patients received vaginal enlarged amputation of cervix, and 264 patients accepted extrafascial hysterectomy. The chi-square test was used to compare the rate of complication and treatment failure of different surgical methods.

RESULTS

The rates of surgical complications for LEEP, CKC, vaginal enlarged amputation of the cervix and extrafascial hysterectomy were, respectively, 8.1% (6/74) 6.2% (54/869) 6.1% (3/49) and 2.3% (8/264), but this difference was not statistically significant. The treatment failure incidences for LEEP, CKC, vaginal enlarged amputation of cervix and external fascia hysterectomy were, respectively, 4.1% (3/74), 0.2% (2/869), 0.0% (0/49) and 0.4% (1/264). When comparing among the groups, the treatment failure incidence was higher in LEEP than that in CKC (p = 0.004) and extrafascial hysterectomy (p = 0.034); there was no statistically significant difference between CKC and extrafascial hysterectomy, and no significant difference was revealed between vaginal enlarged amputation of cervix and any other group.

CONCLUSION

LEEP, CKC, vaginal enlarged amputation of cervix and extrafascial hysterectomy are all secure and effective procedures for patients with CIN, and patients can make their own individual choice depending on different conditions.

A novel metalloprotease from the wild basidiomycete mushroom Lepista nuda

A 20.9-kDa metalloprotease was isolated from dried fruiting bodies of the wild basidiomycete mushroom Lepista nuda. The N-terminal amino acid sequence of the protease was seen to be ATFVLTAATNTLFTA, thus displaying no similarity with the sequences of previously reported metalloproteases. The protease was purified using a procedure that entailed ion-exchange chromatography on CM-Cellulose, Q-Sepharose, and Mono S, and FPLC-gel filtration on Superdex 75. The protease functioned at an optimum pH of 7.0 and an optimum temperature of 50 degrees C. It was also noted that the protease demonstrated a proteolytic activity of 1,756 U/mg toward casein. The Km of the purified protease toward casein was 6.36 mg/ml at a pH of 7.0 and with a temperature of 37 degrees C, whereas the Vmax was 9.11 microgram ml(-1) min(-1). The activity of the protease was adversely affected by EDTA-2Na, suggesting that it is a metalloprotease. PMSF, EGTA, aprotinin, and leupeptin exerted no striking inhibitory effect. The activity of the protease was enhanced by Fe2+, but was curtailed by Cd2+, Cu2+, Hg2+, Pb2+, Zn2+, and Fe3+ ions. The protease also exhibited inhibitory activity against HIV-1 reverse transcriptase with an IC50 value of 4.00 micrometer. The IC50 values toward hepatoma Hep G2 and leukemia L1210 cells in vitro were 4.99 micrometer and 3.67 micrometer, respectively.

Stable silver(I) hydride complexes supported by diselenophosphate ligands

The first stable structure of silver(I) cluster cations [Ag(8)(mu(4)-H){Se(2)P(OR)(2)}(6)](+) [R = (i)Pr, 1; Et, 2] containing Ag(I)-hydride bridges (Ag-mu-H-Ag) in T symmetry was reported. The clusters having an interstitial hydride were composed of an octanuclear silver core in tetracapped tetrahedral geometry, which was inscribed within a Se(12) icosahedron represented by six dialkyl diselenophosphate ligands in a tetrametallic-tetraconnective (mu(2), mu(2)) bonding mode. The presence of hydride was unequivocally corroborated by both (1)H and (109)Ag NMR spectroscopies of which a nonet in the (1)H NMR spectrum for the hydride resonance coupled with a doublet peak observed in the (109)Ag NMR spectrum clearly suggests that eight silver nuclei are equivalent in the NMR time scale and a fast exchange of the positions between the vertex and capping silver atoms in solution must occur. The hypothesis was also supported by a density functional theory (DFT) investigation on a simplified model [Ag(8)(H)(Se(2)PH(2))(6)](+), which confirmed that the Ag(8)H cubic core of T(h) symmetry may not be formed as it is energetically highly unfavorable (0.67 eV less stable than the T structure).