Therapeutic Effects of Anti-PD1 Immunotherapy on Hepatocellular Carcinoma Under Administration of Tacrolimus

BACKGROUND

Liver transplantation (LT) is the treatment of choice for patients with hepatocellular carcinoma (HCC). Recurrence of HCC after LT occurs in 10% to 20% of cases. Preclinical studies to evaluate immune checkpoint inhibitors in conjunction with immunosuppressant treatment in transplant recipients have been lacking. Here, we evaluated the efficacy, safety, and mechanism of programmed cell death-1 (PD1) blockade under tacrolimus treatment in transplant recipients.

METHODS

We used a murine allogeneic skin transplantation model and murine syngeneic subcutaneous and orthotopic HCC models and measured the tumor volume and the change in tumor-infiltrating lymphocytes under PD1 blockade and tacrolimus treatment.

RESULTS

Tacrolimus treatment prolonged allograft survival in the allogeneic transplantation model and enhanced tumor growth in both subcutaneous and orthotopic HCC models. PD1 blockade suppressed tumor growth and lung metastasis in correlation with the number of infiltrating CD8 + T cells. Under tacrolimus treatment, PD1 blockade still resulted in an antitumor effect accompanied by a significant increase in tumor-infiltrating CD8 + T cells, natural killer cells, dendritic cells, and natural killer T cells. Tacrolimus treatment rescued the acceleration of transplant rejection induced by PD1 blockade in the allogeneic transplantation model.

CONCLUSIONS

Our data suggest that treatment with high-dose tacrolimus in conjunction with PD1 blockade has an antitumor effect and reduces transplant rejection in mouse models of allograft skin transplantation and HCC. Thus, these results suggest that a clinical trial of PD1 inhibitors for HCC in LT merits consideration.

Neoantigen vaccination augments antitumor effects of anti-PD-1 on mouse hepatocellular carcinoma

Immune checkpoint inhibitors are groundbreaking resources for cancer therapy. However, only a few patients with hepatocellular carcinoma (HCC) have shown positive responses to anti-PD-1 therapy. Neoantigens are sequence-altered proteins resulting from somatic mutations in cancer. This study identified the neoantigens of Hep-55.1C and Dt81 Hepa1-6 HCCs by comparing their whole exome sequences with those of a normal C57BL/6 mouse liver. Immunogenic long peptides were pooled as peptide vaccines. The vaccination elicited tumor-reactive immune responses in C57BL/6 mice, as demonstrated by IFN-γ ELISPOT and an in vitro killing assay of splenocytes. In the treatment of three mouse HCC models, combined neoantigen vaccination and anti-PD-1 resulted in more significant tumor regression than monotherapies. Flow cytometry of the tumor-infiltrating lymphocytes showed decreased Treg cells and monocytic myeloid-derived suppressor cells, increased CD8⁺ T cells, enhanced granzyme B expression, and reduced exhaustion-related markers PD-1 and Lag-3 on CD8⁺ T cells in the combination group. These findings provide a strong rationale for conducting clinical studies of using neoantigen vaccination in combination with anti-PD-1 to treat patients with HCC.

In situ vaccination followed by intramuscular poly-ICLC injections for the treatment of hepatocellular carcinoma in mouse models

The efficacy of treatment for advanced hepatocellular carcinoma (HCC) has remained limited. Polyinosinic-polycytidylic acid-poly-L-lysine carboxymethylcellulose (poly-ICLC) is a synthetic double-stranded RNA that serves as a viral mimic and induces an immune response. Intratumoral (IT) poly-ICLC injections can induce an autovaccination effect and prime the immune system, whereas intramuscular (IM) injection of poly-ICLC can attract and maintain tumor-specific cytotoxic T lymphocytes in tumors. We found that IT injection of poly-ICLC upregulated the expression of CD83 and CD86 on conventional type 1 dendritic cells in tumors. Combination therapy with IT followed by IM injections of poly-ICLC significantly inhibited tumor growth and increased the tumor-infiltrating CD8⁺ T cells in two syngeneic mouse models of HCC. Depletion of CD8⁺ T cells attenuated the antitumor effect. An IFN-γ enzyme-linked immunospot of purified tumoral CD8⁺ T cells revealed a significant proportion of tumor-specific T cells. Finally, the sequential poly-ICLC therapy induced abscopal effects in two dual-tumor models. This study provides evidence that the sequential poly-ICLC therapy significantly increased infiltration of tumor-specific CD8⁺ T cells in the tumors and induced CD8⁺ T cell-dependent inhibition of tumor growth, as well as abscopal effects.

Silica-based colloid centrifugation enhances sperm quality in cockerel semen

1. Percoll^TM is one of the most widely used colloid for animal sperm preparation. The aim of this study was to evaluate whether Percoll^TM colloid centrifugation could be practical to improve cockerel sperm quality, and to compare the effects of Percoll^TM single layer centrifugation (SLC) and density gradient centrifugation (DGC) in order to obtain the most optimal protocol for cockerel semen.2. In the experiment with Percoll^TM SLC for fresh semen, an increase of motile sperm was seen after Percoll^TM 80% SLC and 90% SLC was conducted, at levels of 28.8% and 30.2% respectively (P < 0.01). The increase of progressively motile sperm after Percoll^TM 80% SLC and 90% SLC was 177.2% and 202.4% respectively (P < 0.01). Meanwhile, for semen stored at 4°C for 24 h, the increase of motile sperm after Percoll^TM 70% SLC and 80% SLC was 41.2% and 44.0% (P < 0.01), and the increase of progressive sperm after Percoll^TM 70% SLC and 80% SLC was 71.3% and 83.1% respectively (P < 0.01). Both the percentage of motile sperm and progressive sperm of the fresh and stored cockerel semen after appropriate Percoll^TM SLC was significantly enhanced.3. Sperm membrane integrity did not show any decrease after Percoll^TM centrifugation compared with non-centrifuged semen, which suggested that the Percoll^TM centrifugation treatment in this study did not cause damage to cockerel sperm membranes.4. In the experiment regarding the comparison of Percoll^TM SLC and DGC with fresh semen, the increase of motile sperm after Percoll^TM 80% SLC, 90% SLC and 40%/80% DGC was 29.5%, 36.4%, and 25.0% respectively; and the increase of progressive sperm was 44.7%, 58.5%, and 54.7%, respectively. For semen stored at 4°C for 24 h, the increase of motile sperm after Percoll^TM 70% SLC, 80% SLC and 35%/70% DGC were 41.2%, 44.0%, and 26.4%; and the increase of progressive sperm was 71.3%, 83.1%, and 43.7%, respectively. There were no significant differences between the increase of sperm motility after Percoll^TM 80%, 90% SLC or Percoll^TM 40%/80% DGC in fresh cockerel semen. There was no significant difference between Percoll^TM 70%, 80% SLC and Percoll^TM 35%/70% in stored cockerel semen. There was a tendency for sperm recovery rates with Percoll^TM SLC to be higher than Percoll^TM DGC, although this did not reach statistical significance in this study.5. It was concluded that Percoll^TM SLC was more suitable for cockerel sperm separation than Percoll^TM DGC. The results suggested that Percoll^TM 80% SLC was the most optimal procedure to separate fresh cockerel sperm and Percoll^TM 70% SLC was the most optimal procedure to separate stored cockerel sperm. Percoll^TM SLC is more simple, user-friendly and economical and less time-consuming than DGC for cockerel semen processing.

Evaluation of cockerel spermatozoa viability and motility by a novel enzyme based cell viability assay

1. The results of spermatozoa assessment by the WST-8 (2-[2-methoxy-4-nitrophenyl]-3-[4-nitrophenyl]-5-[2,4-disulfophenyl]-2H-tetrazolium, monosodium salt) assay, flow cytometry (FC) or computer-assisted sperm analysis (CASA) were compared. 2. Different live/killed ratios of cockerel semen were serially diluted to 120, 60, and 30 × 10⁶ cells/ml, and each sample was analysed by (1) WST-8 assay at 0, 10, 20, 30, 40, 50, 60 min, (2) viability with FC, and (3) motility with CASA. 3. The WST-8 reduction rate was closely correlated with spermatozoa viability and motility. The optimal semen concentration for the WST-8 assay was 120 × 10⁶ cells/ml, and the standard curves for spermatozoa viability and motility predictions, respectively, were y_viability60 = 162.8x + 104.96 (R² = 0.9594) after 60 min of incubation and y_motility40 = 225.09x + 96.299 (R² = 0.8475) after 40 min of incubation. 4. It was concluded that the WST-8 assay is useful for the practical evaluation of cockerel spermatozoa viability and motility. Compared to FC and CASA, the WST-8 assay does not require expensive and complex instrumentation in the lab. Furthermore, one well of the WST-8 reaction can be used to predict spermatozoa viability and motility at the same time, which all lead it to be efficient and economical for semen quality assessment.

Isolated gallbladder rupture following blunt abdominal injury

Isolated traumatic gallbladder rupture subsequent to blunt abdominal injury is rare. Most literatures on the subjects consist of case reports. We reported a rare case of isolated gallbladder rupture and discussed the possible predisposing factors to gallbladder rupture.

25-Hydroxyvitamin D in pregnancy and genome wide cord blood DNA methylation in two pregnancy cohorts (MoBa and ALSPAC)

The aim of the study was to investigate whether maternal mid-pregnancy 25-hydroxyvitamin D concentrations are associated with cord blood DNA methylation. DNA methylation was assessed using the Illumina HumanMethylation450 BeadChip, and maternal plasma 25-hydroxyvitamin D was measured in 819 mothers/newborn pairs participating in the Norwegian Mother and Child Cohort (MoBa) and 597 mothers/newborn pairs participating in the Avon Longitudinal Study of Parents and Children (ALSPAC). Across 473,731CpG DNA methylation sites in cord blood DNA, none were strongly associated with maternal 25-hydroxyvitamin D after adjusting for multiple tests (false discovery rate (FDR)>0.5; 473,731 tests). A meta-analysis of the results from both cohorts, using the Fisher method for combining p-values, also did not strengthen findings (FDR>0.2). Further exploration of a set of CpG sites in the proximity of four a priori defined candidate genes (CYP24A1, CYP27B1, CYP27A1 and CYP2R1) did not result in any associations with FDR<0.05 (56 tests). In this large genome wide assessment of the potential influence of maternal vitamin D status on DNA methylation, we did not find any convincing associations in 1416 newborns. If true associations do exist, their identification might require much larger consortium studies, expanded genomic coverage, investigation of alternative cell types or measurements of 25-hydroxyvitamin D at different gestational time points.

A unique disulfide bridge of the thermophilic xylanase SyXyn11 plays a key role in its thermostability

Based on the hyperthermostable family 11 xylanase (EvXyn11(TS)) gene sequence (EU591743), the gene Syxyn11 encoding a thermophilic xylanase SyXyn11 was synthesized with synonymous codons biasing towards Pichia pastoris. The homology alignment of primary structures among family 11 xylanases revealed that, at their N-termini, only SyXyn11 contains a disulfide bridge (Cys5-Cys32). This to some extent implied the significance of the disulfide bridge of SyXyn11 to its thermostability. To confirm the correlation between the N-terminal disulfide bridge and thermostability, a SyXyn11(C5T)-encoding gene, Syxyn11(C5T), was constructed by mutating the Cys5 codon of Syxyn11 to Thr5. Then, the genes for the recombinant xylanases, reSyXyn11 and reSyXyn11(C5T), were expressed in P. pastoris GS115, yielding xylanase activity of about 35 U per ml cell culture. Both xylanases were purified to homogeneity with specific activities of 363 and 344 U/mg, respectively. The temperature optimum and stability of reSyXyn11(C5T) decreased to 70 and 50°C from 85 and 80°C of reSyXyn11, respectively. There was no obvious change in pH characteristics.

D-galactan II is an immunodominant antigen in O1 lipopolysaccharide and affects virulence in Klebsiella pneumoniae: implication in vaccine design

In the O1 strain of Klebsiella, the lipopolysaccharide (LPS) O-antigen is composed of D-galactan I and D-galactan II. Although the composition of the O1 antigen of Klebsiella was resolved more than two decades, the genetic locus involved in the biosynthesis of D-galactan II and the role of D-galactan II in bacterial pathogenesis remain unclear. Here, we report the identification of the D-galactan II-synthesizing genes by screening a transposon mutant library of an acapsulated Klebsiella pneumoniae O1 strain with bacteriophage. K. pneumoniae strain deleted for wbbY exhibited abrogated D-galactan II production; altered serum resistance and attenuation of virulence. Serologic analysis of K. pneumoniae clinical isolates demonstrated that D-galactan II was more prevalent in community-acquired pyogenic liver abscess (PLA)—causing strains than in non-tissue-invasive strains. WbbY homologs, WbbZ homologs, and lipopolysaccharide structures based on D-galactan II also were present in several Gram-negative bacteria. Immunization of mice with the magA-mutant (K⁻₁ O₁) (that is, with a LPS D-galactan II-producing strain) provided protection against infection with an O1:K2 PLA strain. Our findings indicate that both WbbY and WbbZ homologs are sufficient for the synthesis of D-galactan II. D-galactan II represents an immunodominant antigen; is conserved among multiple species of Gram-negative bacteria and could be a useful vaccine candidate.

Isolation of a bacteriophage and its depolymerase specific for K1 capsule of Klebsiella pneumoniae: implication in typing and treatment

BACKGROUND

Klebsiella pneumoniae causing community-acquired pyogenic liver abscess complicated with metastatic meningitis and endophthalmitis has emerged recently, most frequently associated with the K1 capsular type.

METHODS

A bacteriophage (NTUH-K2044-K1-1) that infects K. pneumoniae NTUH-K2044 (capsular type K1) was isolated and characterized.

RESULTS

The phage infected all K1 strains, and none of the strains with other capsular types. Capsule deletion mutants were not lysed by this phage, suggesting that the capsule was essential for phage infection. Complete genome sequencing revealed the phage was a novel phiKMV-like virus. The gene-encoding capsule depolymerase was identified. The recombinant enzyme demonstrated specific lysis of the K1 capsule. Treatment with the phage or the recombinant enzyme provided significantly increased survival in mice infected with NTUH-K2044 strain, including one treated after the detection of a neck abscess by imaging. No obvious disease was observed after administration of this phage in mice. Phage was retained at detectable levels in liver, spleen, brain, and blood 24 hours after administration in mice.

CONCLUSIONS

These results demonstrate this phage and its capsule depolymerase exhibit specificity for capsular type K1 and can be used for the diagnosis and treatment of K1 K. pneumoniae infections.

Polymorphic microsatellite loci isolated from Cervus unicolor (Cervidae) show inbreeding in a domesticated population of Taiwan Sambar deer

Primers for eight microsatellites were developed; they successfully amplified DNA from 20 domesticated Formosan Sambar deer (Cervus unicolor swinhoei). All loci were polymorphic, with 10-19 alleles per locus. The average observed heterozygosity across loci and samples was 0.310, ranging from 0 to 0.750 at each locus. All loci but one, CU18, deviated from Hardy-Weinberg equilibrium due to excessive homozygosity in these domesticated broodstocks, reflecting inbreeding. These microsatellite loci will be useful, not only for assessment of population structure and genetic variability, but also for conservation of wild deer populations in Taiwan.

Capsular types of Klebsiella pneumoniae revisited by wzc sequencing

Capsule is an important virulence factor in bacteria. A total of 78 capsular types have been identified in Klebsiella pneumoniae. However, there are limitations in current typing methods. We report here the development of a new genotyping method based on amplification of the variable regions of the wzc gene. Fragments corresponding to the variable region of wzc were amplified and sequenced from 76 documented capsular types of reference or clinical strains. The remaining two capsular types (reference strains K15 and K50) lacked amplifiable wzc genes and were proven to be acapsular. Strains with the same capsular type exhibited ≧94% DNA sequence identity across the variable region (CD1-VR2-CD2) of wzc. Strains with distinct K types exhibited <80% DNA sequence identity across this region, with the exception of three pairs of strains: K22/K37, K9/K45, and K52/K79. Strains K22 and K37 shared identical capsular polysaccharide synthesis (cps) genes except for one gene with a difference at a single base which resulted in frameshift mutation. The wzc sequences of K9 and K45 exhibited high DNA sequence similarity but possessed different genes in their cps clusters. K52 and K79 exhibited 89% wzc DNA sequence identity but were readily distinguished from each other at the DNA level; in contrast, strains with the same capsular type as K52 exhibited 100% wzc sequence identity. A total of 29 strains from patients with bacteremia were typed by the wzc system. wzc DNA sequences confirmed the documented capsular type for twenty-eight of these clinical isolates; the remaining strain likely represents a new capsular type. Thus, the wzc genotyping system is a simple and useful method for capsular typing of K. pneumoniae.

Partial hepatectomy for ruptured hepatocellular carcinoma

BACKGROUND

Improvements in surgical technique and perioperative care have made partial hepatectomy a safe and effective treatment for hepatocellular carcinoma (HCC), even in the event of spontaneous HCC rupture.

METHODS

A consecutive cohort of patients who underwent partial hepatectomy for HCC between 2000 and 2009 was divided into a ruptured group and a non-ruptured group. Patients with ruptured HCC were further divided into emergency and staged hepatectomy subgroups. Mortality and morbidity, overall survival and recurrence-free survival (RFS) were compared. Prognostic factors for overall survival and RFS were identified by univariable and multivariable analyses.

RESULTS

A total of 1233 patients underwent partial hepatectomy for HCC, of whom 143 had a ruptured tumour. The morbidity and mortality rates were similar in the ruptured and non-ruptured groups, as well as in the emergency and staged subgroups. In univariable analyses, overall survival and RFS were lower in the ruptured group than in the non-ruptured group (both P < 0·001), and also in the emergency subgroup compared with the staged subgroup (P = 0·016 and P = 0·025 respectively). In multivariable analysis, spontaneous rupture independently predicted poor overall survival after hepatectomy (hazard ratio 1·54, 95 per cent confidence interval 1·24 to 1·93) and RFS (HR 1·75, 1·39 to 2·22). Overall survival and RFS after hepatectomy for ruptured HCC in the emergency and staged subgroups were not significantly different in multivariable analyses.

CONCLUSION

Spontaneous rupture predicted poor long-term survival after hepatectomy for HCC, but surgical treatment seems possible, safe and appropriate in selected patients.

Klebsiella pneumoniae peptidoglycan-associated lipoprotein and murein lipoprotein contribute to serum resistance, antiphagocytosis, and proinflammatory cytokine stimulation

BACKGROUND

Peptidoglycan-associated lipoprotein (Pal), murein lipoprotein (LppA), and outer membrane protein A (OmpA) are dominant outer membrane proteins (OMPs) that are released by gram-negative bacteria during sepsis. OMPs are implicated in the maintenance of cell envelope integrity. Here, we characterize the roles of these OMPs in pathogenesis during bacteremia caused by Klebsiella pneumoniae.

METHODS

pal-, lppA-, and ompA-deficient K. pneumoniae strains were constructed using an unmarked deletion method. Serum sensitivity, antiphagocytosis activity, outer membrane permeability, and sensitivity to anionic detergents and antimicrobial polypeptides were determined for these OMP gene deletion mutants. The ability of these OMP gene deletion mutants to induce immune responses was compared with that of the wild-type strain in a bacteremic mouse model.

RESULTS

Klebsiella pneumoniae strains deleted for pal or lppA exhibited reduced protection from serum killing and phagocytosis; perturbation to the outer membrane permeability barrier and hypersensitivity to bile salts and sodium dodecyl sulfate. The strain mutated for lppA had reduced ability to activate Toll-like receptor 4. Immunization of mice with the pal or lppA mutant provided protection against infection by the wild-type strain.

CONCLUSIONS

Our findings indicate that K. pneumoniae Pal and LppA proteins are important in the maintenance of cell integrity, contribute to virulence, and could be used as attenuated vaccines.

Cloning and bioinformatic analysis of an acidophilic beta-mannanase gene, Anman5A, from Aspergillus niger LW-1

Using 3' and 5' rapid amplification of cDNA ends (RACE) techniques, the full-length cDNA sequence of the AnmanSA, a gene that encodes an acidophilic beta-mannanase of Aspergillus niger LW-1 (abbreviated to AnMan5A), was identified from the total RNA. The cDNA sequence was 1417 bp in length, harboring 5'- and 3'-untranslated regions, as well as an open reading frame (ORF) which encodes a 21-aa signal peptide, a 17-aa propeptide and a 345-aa mature peptide. Based on the topology of the phylogenetic tree of beta3-mannanases from glycoside hydrolase (GH) family 5, the AnMan5A belongs to the subfamily 7 of the GH family 5. Its 3D structure was modeled by the bitemplate-based method using both MODELLER 9.9 and SALIGN programs, based on the known beta-mannanase crystal structures of Trichoderma reesei (1QNO) and Lycopersicon esculentum (1RH9) from the GH family 5. In addition, the complete DNA sequence of the Anman5A was amplified from the genomic DNA using the pUCm-T vector-mediated PCR and conventional PCR methods. The DNA sequence was 1825 bp in length, containing a 5'-flanking regulatory region, 2 introns and 3 exons when compared with the full-length cDNA.

Lipopolysaccharide O1 antigen contributes to the virulence in Klebsiella pneumoniae causing pyogenic liver abscess

Klebsiella pneumoniae is the common cause of a global emerging infectious disease, community-acquired pyogenic liver abscess (PLA). Capsular polysaccharide (CPS) and lipopolysaccharide (LPS) are critical for this microorganism's ability to spread through the blood and to cause sepsis. While CPS type K1 is an important virulence factor in K. pneumoniae causing PLA, the role of LPS in PLA is not clear. Here, we characterize the role of LPS O antigen in the pathogenesis of K. pneumoniae causing PLA. NTUH-K2044 is a LPS O1 clinical strain; the presence of the O antigen was shown via the presence of 1,3-galactan in the LPS, and of sequences that align with the wb gene cluster, known to produce O-antigen. Serologic analysis of K. pneumoniae clinical isolates demonstrated that the O1 serotype was more prevalent in PLA strains than that in non-tissue-invasive strains (38/42 vs. 9/32, P<0.0001). O1 serotype isolates had a higher frequency of serum resistance, and mutation of the O1 antigen changed serum resistance in K. pneumoniae. A PLA-causing strain of CPS capsular type K2 and LPS serotype O1 (i.e., O1:K2 PLA strain) deleted for the O1 synthesizing genes was profoundly attenuated in virulence, as demonstrated in separate mouse models of septicemia and liver abscess. Immunization of mice with the K2044 magA-mutant (K(1) (-) O(1)) against LPS O1 provided protection against infection with an O1:K2 PLA strain, but not against infection with an O1:K1 PLA strain. Our findings indicate that the O1 antigen of PLA-associated K. pneumoniae contributes to virulence by conveying resistance to serum killing, promoting bacterial dissemination to and colonization of internal organs after the onset of bacteremia, and could be a useful vaccine candidate against infection by an O1:K2 PLA strain.

Cutaneous sarcoidosis in southern Taiwan: clinicopathologic study of a series with high proportions of lesions confined to the face and angiolupoid variant

BACKGROUND

Sarcoidosis is a multisystem granulomatous disorder of unknown aetiology. Our clinical experience suggests that facial involvement and the angiolupoid variant appear more common in our patients compared with series reported from the western countries.

OBJECTIVE

To characterize the clinicopathologic features of cutaneous sarcoidosis diagnosed in our department and to compare our data with those in the literature.

METHODS

We conducted a clinicopathologic review of biopsy-proved cases of cutaneous sarcoidosis diagnosed during January 2002-December 2010.

RESULTS

Our study consisted of 37 patients, ages 26-84 years (mean 54.3 years), of whom 84% were females. Systemic involvement was detected in 73%, affecting the lung in 57%, lymph nodes in 65% and eyes in 43%. Most skin lesions were the papulonodular type (70%) and confined to the face (54%). The angiolupoid variant, while rare in Europe and America, was the most common variant (38%) in our series and often associated with eye involvement. The histology was characterized by infiltration of naked sarcoidal granulomas, mostly (86%) mixed with variable amounts of tuberculoid granulomas in the dermis and/or the subcutis. Other findings included fibrinoid necrosis (23%), foreign bodies (16%), osteoclast-like cells (14%) and granuloma annulare-like and necrobiosis lipoidica-like features.

CONCLUSION

The present series of cutaneous sarcoidosis was characterized by a marked female predominance and by high proportions of facial involvement and the angiolupoid variant. Angiolupoid sarcoidosis was often associated with eye involvement. A complete dermatologic examination and biopsy of suspicious skin lesions should be routinely performed to facilitate early diagnosis of sarcoidosis.

Cloning and sequence analysis of complete gene encoding an alkaline lipase from Penicillium cyclopium

The complete gene (PG37 lipI) encoding an alkaline lipase (PG37 LipI) was cloned from the genomic DNA of Penicillium cyclopium PG37. The cloned PG37 lipI is 2020 bp in length, consisting of 632 bp of the 5' flanking promoter region and 1388 bp of the downstream fragment that contains 6 exons and 5 short introns. The promoter region harbors putative TATA box, CAAT box and several transcription factor binding sites. The open reading frame (ORF) encodes a PG37 LipI of 285 amino acid residues, which was predicted to contain a 20-aa signal peptide, a 7-aa propeptide and a 258-aa mature peptide with a conserved motif Gly-X-Ser-X-Gly. However, PG37 LipI shows only 32%, 30%, 28% and 26% identity with lipases of Aspergillus parasiticus, Penicillium camembertii, Thermomyces lanuginosus and Rhizomucor miehei, respectively. It was predicted that the main secondary structures of PG37 LipI are alpha-helix and random coil. Three amino acid residues, Ser132-Asp188-His241, compose the enzymatic active center in the tertiary structure.

Isolation of genes involved in biofilm formation of a Klebsiella pneumoniae strain causing pyogenic liver abscess

BACKGROUND

Community-acquired pyogenic liver abscess (PLA) complicated with meningitis and endophthalmitis caused by Klebsiella pneumoniae is an emerging infectious disease. To investigate the mechanisms and effects of biofilm formation of K. pneumoniae causing PLA, microtiter plate assays were used to determine the levels of biofilm formed by K. pneumoniae clinical isolates and to screen for biofilm-altered mutants from a transposon mutant library of a K. pneumoniae PLA-associated strain.

METHODOLOGY/PRINCIPAL FINDINGS

The biofilm formation of K. pneumoniae was examined by microtiter plate assay. Higher levels of biofilm formation were demonstrated by K. pneumoniae strains associated with PLA. A total of 23 biofilm-decreased mutants and 4 biofilm-increased mutants were identified. Among these mutants, a biofilm-decreased treC mutant displayed less mucoviscosity and produced less capsular polysaccharide (CPS), whereas a biofilm-increased sugE mutant displayed higher mucoviscosity and produced more CPS. The biofilm phenotypes of treC and sugE mutants also were confirmed by glass slide culture. Deletion of treC, which encodes trehalose-6-phosphate hydrolase, impaired bacterial trehalose utilization. Addition of glucose to the culture medium restored the capsule production and biofilm formation in the treC mutant. Transcriptional profile analysis suggested that the increase of CPS production in ΔsugE may reflect elevated cps gene expression (upregulated through rmpA) in combination with increased treC expression. In vivo competition assays demonstrated that the treC mutant strain was attenuated in competitiveness during intragastric infection in mice.

CONCLUSIONS/SIGNIFICANCE

Genes important for biofilm formation by K. pneumoniae PLA strain were identified using an in vitro assay. Among the identified genes, treC and sugE affect biofilm formation by modulating CPS production. The importance of treC in gastrointestinal tract colonization suggests that biofilm formation contributes to the establishment and persistence of K. pneumoniae infection.

Angle-independent plasmonic infrared band-stop reflective filter based on the Ag/SiO₂/Ag T-shaped array

A plasmonic infrared (IR) filter assisted by localized surface plasmon polaritons (LSPPs) in a Ag/SiO₂/Ag T-shaped array was theoretically and experimentally investigated. By using a Fourier transform infrared (FTIR) spectrometer, an angle-independent LSPP resonant mode caused by a Fabry-Pérot resonance in the structure was observed in agreement with the prediction from the rigorous coupled-wave analysis (RCWA) simulation. The resonant wavelength of the mode can also be controlled by modifying the geometry of the T-shaped structure. Such LSPP property can be used as an IR reflection-type band-stop filter with a single spectral bandwidth and an ultrahigh immunity to incident angles.

Compact optical curvature sensor with a flexible microdisk laser on a polymer substrate

We demonstrate a chip-scale compact optical curvature sensor. It consists of a low threshold InGaAsP microdisk laser on a flexible polydimethylsiloxane polymer substrate. The curvature dependence of lasing wavelength was characterized by bending the cavity at different bending radii. The measurements showed that the lasing wavelength decreases monotonously with an increasing bending curvature. A good agreement between experiment and three-dimensional finite-difference time-domain simulation was also obtained. The sensitivity of the compact device to the bending curvature is -23.7 nm/mm from the experiment.

Joint report of the Third International Bovine Lymphocyte Antigen (BoLA) Workshop, Helsinki, Finland, 27 July 1986

Two hundred and eighty-two alloantisera were submitted by 20 participating laboratories from 13 countries and tested against lymphocytes of 1298 cattle. The cell panel consisted of samples from 38 Bos taurus breeds, 11 Bos taurus crossbreeds, 4 Bos indicus breeds, 6 Bos taurus x Bos indicus, and a variety of other crossbred populations. Using a standardized lymphocytotoxicity test, all 17 previously identified BoLA specificities were confirmed. The workshop produced agreement on 16 new lymphocyte alloantigenic specificities. Three of the new specificities behaved as splits of previously identified BoLA specificities. Four of the new specificities behaved as alleles at the agreed BoLA-A locus. Seven new specificities are tentatively assigned to the BoLA-A locus but require further definition. Two new specificities may represent products of a second closely-linked BoLA locus.

Inhibitions of vascular endothelial growth factor expression and foam cell formation by EGb 761, a special extract of Ginkgo biloba, in oxidatively modified low-density lipoprotein-induced human THP-1 monocytes cells

It has been reported that oxidatively modified low-density lipoprotein (Ox-LDL) involvement with vascular endothelial growth factor (VEGF) and foam cell formation play an important role in atherosclerosis (AS). Protective effects of Ginkgo biloba extract (EGb 761) have been identified for some cardiovascular and neurological disorders. The aim of this study was to investigate whether Ox-LDL regulates VEGF expression in human THP-1 monocytes, as well as the effect of EGb 761 on VEGF expression and the formation of foam cells. After exposure to Ox-LDL alone or in combination with EGb 761 for up to 48h, cell viability was measured using the MTT assay. VEGF protein content in the supernatant was analyzed by enzyme-linked immunosorbent assay (ELISA). VEGF mRNA was determined by real-time PCR. To determine the effect of EGb 761 on foam cell formation, an Ox-LDL-induced foam cell model was used. Ox-LDL inhibited the growth of THP-1 cells and EGb 761 increased the cell survival rate. Ox-LDL markedly increased VEGF expression in THP-1 cells in a time- and concentration-dependent manner, which was significantly suppressed by EGb 761. EGb 761 also inhibited monocyte/macrophage-derived foam cell formation. These results suggest that Ox-LDL is involved in the development of human AS through VEGF induction in monocytes, and that EGb 761 prevents in vitro atherogenesis, probably via downregulation of VEGF expression in monocytes and inhibition of monocyte/macrophage-derived foam cell formation. The findings suggest a mechanism for the in vivo anti-AS effect of EGb 761 and support its potential clinical use in AS.

Flexible compact microdisk lasers on a polydimethylsiloxane (PDMS) substrate

Compact microdisk cavities were fabricated on a polydimethylsiloxane substrate. The lasing of the flexible compact cavity was achieved with a low threshold power. The whispering-gallery mode of the microdisk was also characterized with three-dimensional finite-difference time-domain simulation. The curvature dependence in output power and threshold was also demonstrated by bending the microdisk cavity.

Structural and functional analysis of nanopillar spin electronic devices fabricated by 3D focused ion beam lithography

We discuss the fabrication of nanopillar spin electronic devices from metal multilayered heterostructures, utilizing a novel three-dimensional focused ion beam lithography process. Finite element simulation was performed to optimize the geometry of the nanopillar device and to demonstrate that current flow is perpendicular to the plane within the active region of the device. Clear zero-field current induced magnetization switching is observed in our nanopillar devices at room temperature.

In vitro effects of preservatives in nasal sprays on human nasal epithelial cells

BACKGROUND

The preservatives benzalkonium chloride and potassium sorbate are widely used in nasal drops and sprays. Recently, side effects resulting from mucosal damage caused by benzalkonium chloride and potassium sorbate were reported.

METHODS

We investigated the toxicity of benzalkonium chloride and potassium sorbate on human nasal epithelial cells in vitro. Using primary human nasal epithelial cells, different concentrations of benzalkonium chloride, potassium sorbate, or phosphate-buffered saline (PBS; control group) solutions were cocultured with nasal epithelial cells for 15 minutes. Then, the viability of the cells and the cell morphology were assessed.

RESULTS

Nasal epithelial cells were more severely damaged with use of clinical preparations or higher concentrations of benzalkonium chloride than in the control group. In addition, nasal epithelial cell membrane lysis was seen on electronic microscopy in the benzalkonium chloride groups. In contrast, there was no significant cell damage seen in the potassium sorbate groups compared with the control group, even with higher concentrations than clinically used.

CONCLUSION

Potassium sorbate appears to be a relatively safer preservative than benzalkonium chloride for use in nasal sprays and drops in vitro study.

Quantification of pre-parturition restlessness in crated sows using ultrasonic measurement

This study presents the non-video, noninvasive, automatic, and on-site monitoring system employing ultrasonic transducers to detect the behavior in sows before, during and after parturition. An ultrasonic transmitting/receiving (T/R) circuit of 40kHz is mounted above a conventional parturition bed. The T/R units use ultrasonic time-of-flight (TOP) ranging technology to measure the height of the confined sows at 8 predetermined locations. It is suggested that the system could be applied to automatic prediction of sow parturition, with automatic notification of remote management personnel so human attendance at the birth could reduce rates of sow and piglet mortality.

Impaired clearance of phenacetin in hepatic cirrhosis and fibrosis

OBJECTIVE

CYP450 1A2 is constitutively expressed in liver. Phenacetin O-de-ethylation is a marker reaction for CYP450 1A2 activity. In this paper, the metabolism of phenacetin has been studied in patients with chronic hepatitis B or cirrhosis secondary to a hepatitis B virus infection. The possibility of using the phenacetin test in the evaluation of liver function in these subjects has also been tested.

SUBJECTS AND METHODS

Phenacetin pharmacokinetics and the recovery of its urinary metabolites were studied in 8 normal subjects, 16 patients with chronic hepatitis B and 12 patients with cirrhosis. The phenacetin test was performed in 18 normal subjects and 52 hepatocellular carcinoma (HCC) patients. The test was repeated in HCC patients after treatment with transcatheter arterial chemoembolization (TACE).

RESULTS

Compared with normal controls, phenacetin apparent clearance decreased by 47.0% (p < 0.05) and 78.7% (p < 0.01) in patients with chronic hepatitis B and cirrhosis, respectively. The recovery of phenacetin O-de-ethylated metabolites decreased by 24.6 and 72.4% (p < 0.01). 46 of 52 HCC patients (88.4%) had an abnormal phenacetin test before TACE, where the ratio of plasma total acetaminophen to phenacetin was below the lower limit of the normal control range. The ratio was less than 50% of normal controls in 6 HCC patients who had a deterioration in liver function from Child-Pugh class A to Child-Pugh class B after TACE.

CONCLUSION

The metabolism of phenacetin is impaired in patients with chronic hepatitis B and cirrhosis. The phenacetin test can predict the susceptibility of liver function to TACE in HCC patients.

In vitro andin vivo biological responses of plasma-sprayed hydroxyapatite coatings with posthydrothermal treatment

This study was undertaken to evaluate the effect of post-hydrothermal treatment on the biological responses of the plasma-sprayed hydroxyapatite (HA)-coated Ti-6Al-4V implant system both in vitro and in vivo. After hydrothermal treatment, the HA coating (HAC) shows the high mechanical strength and indices-of-crystallinity, denser microstructure, lower concentrations of amorphous and impurity phases, when compared with the as-sprayed HAC. The in vitro cell-culture studies, using UMR106 osteoblast-like cell, demonstrated no signifiacnt cell growth on both surface of as-sprayed and hydrothermal-treated HACs during 10-day culture. The in vivo studies, using the transcortical implant model in the femora of goats, evaluated the histological responses of two coatings. After 6 week of implantation, using backscattered electron images, no substantial histological variations in the extents of new bone apposition and new bone healing between the two HACs were observed. However, the as-sprayed HAC, owing to the dissolution induced the granular particles dissociated from the HAC, showed the statically lower extent of new bone apposition than hydrothermal-treated HAC at 12 weeks. The results suggest that hydrothermal treatment could be used to improve the mechanical strength, crystallinity, and phase composition of HAC, which are important factors of long-term fixation and stability of implant. Besides, the treated HAC could also achieve the initial fixation of implant in clinical use.

Characterization of the uracil-DNA glycosylase activity of Epstein-Barr virus BKRF3 and its role in lytic viral DNA replication

Uracil-DNA glycosylases (UDGs) of the uracil-N-glycosylase (UNG) family are the primary DNA repair enzymes responsible for removal of inappropriate uracil from DNA. Recent studies further suggest that the nuclear human UNG2 and the UDGs of large DNA viruses may coordinate with their DNA polymerase accessory factors to enhance DNA replication. Based on its amino acid sequence, the putative UDG of Epstein-Barr virus (EBV), BKRF3, belongs to the UNG family of proteins, and it was demonstrated previously to enhance oriLyt-dependent DNA replication in a cotransfection replication assay. However, the expression and enzyme activity of EBV BKRF3 have not yet been characterized. In this study, His-BKRF3 was expressed in bacteria and purified for biochemical analysis. Similar to the case for the Escherichia coli and human UNG enzymes, His-BKRF3 excised uracil from single-stranded DNA more efficiently than from double-stranded DNA and was inhibited by the purified bacteriophage PBS1 inhibitor Ugi. In addition, BKRF3 was able to complement an E. coli ung mutant in rifampin and nalidixic acid resistance mutator assays. The expression kinetics and subcellular localization of BKRF3 products were detected in EBV-positive lymphoid and epithelial cells by using BKRF3-specific mouse antibodies. Expression of BKRF3 is regulated mainly by the immediate-early transcription activator Rta. The efficiency of EBV lytic DNA replication was slightly affected by BKRF3 small interfering RNA (siRNA), whereas cellular UNG2 siRNA or inhibition of cellular and viral UNG activities by expressing Ugi repressed EBV lytic DNA replication. Taking these results together, we demonstrate the UNG activity of BKRF3 in vitro and in vivo and suggest that UNGs may participate in DNA replication or repair and thereby promote efficient production of viral DNA.

Plasma glucose-lowering action of Hon-Chi in streptozotocin-induced diabetic rats

Hon-Chi was used for anti-hyperglycemic activity screening in streptozotocin-induced diabetic rats (STZ-diabetic rats) in an attempt to develop new substances for handling diabetes. Mandarin Hon-Chi is red yeast rice fermented with Monascus pilous and Monascus purpureus. Single oral administration of Hon-Chi decreased plasma glucose in STZ-diabetic rats in a dose-dependent manner from 50 mg/kg to 350 mg/kg. Similar treatment with Hon-Chi also lowered the plasma glucose in normal rats as effectively as that produced in STZ-diabetic rats. In addition, oral administration of Hon-Chi at the highest dose (350 mg/kg) attenuated the elevation of plasma glucose induced by an intravenous glucose challenge test in normal rats. Moreover, mRNA levels of phosphoenolpyruvate carboxykinase (PEPCK) in liver from STZ-diabetic rats were reversed in a dose-dependent manner by the repeated oral treatment of Hon-Chi three times daily for two weeks. Otherwise, hyperphagia in STZ-diabetic rats was markedly reversed by similar repeated treatment of Hon-Chi. The obtained results suggest that oral administration of Hon-Chi could decrease hepatic gluconeogenesis to lower plasma glucose in diabetic rats lacking insulin.

Increase of insulin sensitivity by stevioside in fructose-rich chow-fed rats

The intake of dietary fructose has undergone a marked increase around the world, especially the developed countries, in recent times. Stevioside, a glycoside contained in the leaves of Stevia rebaudiana Bertoni (Compositae), was used to screen the effect induced by a diet containing 60% fructose on insulin resistance in rats. Single oral administration of stevioside for 90 min decreased plasma glucose concentrations in a dose-dependent manner in rats receiving fructose-rich chow for four weeks. In addition, insulin action on glucose disposal rate was measured using the glucose-insulin index, the product of the areas under the curve of glucose, and insulin during the intraperitoneal glucose tolerance test. Oral administration of stevioside (5.0 mg/kg) in rats given four weeks of fructose-rich chow for 90 min reversed the value of glucose-insulin index, indicating that stevioside has the ability to improve insulin sensitivity in this insulin-resistant animal model. Time for the loss of plasma glucose lowering response to tolbutamide (10.0 mg/kg, i. p.) in fructose-rich chow fed rats was also markedly delayed by repeated stevioside treatment three times daily compared to the vehicle-treated group. The plasma glucose-lowering activity of tolbutamide was introduced to account for varying levels of endogenous insulin secretion, and is widely used as the indicator of insulin resistance development. Thus, it provided the supportive data that repeated oral administration of stevioside delayed the development of insulin resistance in rats on a high-fructose diet. Increased insulin sensitivity by stevioside administration was further identified using the plasma glucose-lowering action of exogenous insulin in streptozotocin-induced diabetic rats (STZ-diabetic rats). Oral administration of stevioside at 0.2 mg/kg three times daily into STZ-diabetic rats for ten days increased the response to exogenous insulin. Taken together, this demonstrated that oral administration of stevioside improves insulin sensitivity, and seems suitable as an adjuvant for diabetic patients and/or those that consume large amounts of fructose.

Conjugation metabolism of acetaminophen and bilirubin in extrahepatic tissues of rats

An anhepatic rat model was used to explore the extrahepatic conjugating metabolism of acetaminophen and serum bilirubin. The recovery of glucuronide- and sulfate-acetaminophen was 47.5% in normal control and 13.4% in model rats in the urine collected for 6 h after administration of acetaminophen 20 mg kg(-1). Following the increase of acetaminophen dose to 150 mg kg(-1), the recovery of urinary glucuronide-acetaminophen increased by 53.9% in normal control; but it decreased by 36.4% in model rats. In contrast to normal control, the pretreatment with phenobarbital did not affect acetaminophen and its metabolite levels in plasma and urine in model rats. After the establishment of anhepatic model the serum direct bilirubin rose dramatically. Urinary bilirubin test was positive in model rats, but not in normal control. No changes were observed in serum total bilirubin and ratio of direct/total bilirubin after the pretreatment with ranitidine or phenobarbital 50 mg kg (-1), i.p. for 5 days in model rats. The results indicate that the glucuronide- and sulfate-acetaminophen formed in the extrahepatic tissues of model rats is 28.2% of normal control, serum free bilirubin can be transformed into conjugated bilirubin in extrahepatic tissues, and the regulation mechanism of phase II conjugating enzymes is different between the hepatic and extrahepatic tissues.

Polymorphisms of the interleukin-4 gene in chinese patients with systemic lupus erythematosus in Taiwan

We aimed to evaluate the relationship between two polymorphisms of the IL4 gene (-590T/C and intron 3) and systemic lupus erythematosus in Chinese patients in Taiwan. This study included 91 patients with systemic lupus erythematosus (SLE) and 163 unrelated, age matched healthy controls living in the same area. The typing of -590T/C and intron 3 VNTR (variable number of tandem repeats) polymorphisms were performed by PCR-RFLP and PCR, respectively. Allelic frequencies and carriage rates between SLE patients and controls were compared, and the relationship between allelic frequencies and clinical manifestations of SLE was evaluated. The genotype frequencies of IL-4 intron 3 were found to differ significantly between SLE patients with and without discoid rash (chi-square test, P = 0.03 5). The allelic frequency of intron 3 RP1 was significant different in the patients with discoid rash when compared to patients without this clinical feature (OR = 3.70, 95% CI 2.04-6.72, chi2 test, P = 0.029). The RP1/RP1 homozygous carriage was significantly associated with patients with discoid rash when compared to patients without this clinical feature (OR = 6.04, 95% CI 2.81-12.95, P = 0.01). The allelic frequency of -590T was significant different in the patients with discoid rash when compared to patients without this clinical feature (OR = 3.44, 95% CI 1.88-6.31, chi-square test, P=0.04). The T/T homozygous carriage was significantly associated with patients with discoid rash when compared to patients without this clinical feature (OR = 5.41, 95% CI 2.50-11.68, P = 0.02). We describe a novel association between RPI/RPI and T/T homozygous carriage and patients with discoid rash. The role of the intron 3 polymorphism of the IL4 gene in SLE remains unclear and further substantiation based on larger patient samples is needed.

Association of vitamin D receptor gene BsmI polymorphisms in Chinese patients with systemic lupus erythematosus

The purpose of this study was to evaluate whether vitamin D receptor (VDR) genes BsmI polymorphisms were markers for susceptibility to or severity of systemic lupus erythematosus (SLE) in Chinese patients in Taiwan. The study included 47 Chinese patients with SLE. In addition, 90 unrelated, healthy individuals living in central Taiwan served as control subjects. Each polymorphism was detected as a result of polymerase chain reaction (PCR)-based restriction analysis. A PCR product length was determined to be 580bp (BB) whereas two fragments of 405 and 175bp were determined to be excisable lengths (bb) by BsmI endonuclease. The relationship between Bsm polymorphisms and clinical manifestations of SLE was evaluated. We found that BB was significantly more common and bb less common in SLE than in control group (chi2 = 54.2, P < 0.0001). In addition, the frequency of B allele was also significantly more common in patients with SLE than in the healthy control subjects (chi2 = 38.7, P < 0.0001), giving an odds ratio of 7.14 (95% confidence interval 3.53-14.4). In the SLE patients, we did not detect any associations of VDR genotype with the clinical, laboratory profiles, or lupus nephritis (chi2 = 2.34, P = 0.3). This study indicated an increased distribution of VDR BB genotype and B allelic frequencies in the Chinese SLE patients in Taiwan. However, there were no associations between the frequency of VDR allelic variations and clinical manifestations, laboratory profiles, or lupus nephritis.

Sensitization of a tumor, but not normal tissue, to the cytotoxic effect of ionizing radiation using Panax notoginseng extract

The aim of the present study was to investigate any sensitization effect of the Panax notoginseng extract (PNE) and the purified Saponin (Rb1) on the radiation response of an experimental tumor (KHT sarcoma) in mice, in comparison with any effects on a normal tissue (bone marrow). PNE at a concentration of 0.1-100 mg/kg produced an increase in tumor radiosensitivity. The sensitization effect was maximal at 10 mg/kg and at 30 minutes after injection. Higher doses were toxic to the bone marrow stem cells. Similarly Rb1 at a concentration 0.001 to 1 mg/kg also produced an increase in tumor radiosensitivity, with maximum effect at 1 mg/kg. Higher doses were not toxic to the bone marrow stem cells in this case. Radiosensitization factors were calculated as ratios of D0 (the radiosensitivity parameter), and these were highly significant for the tumor and very similar for both compounds at the doses used, namely 1.18-1.19. There was no significant effect for bone marrow stem cells (sensitization factors of 0.99 +/- 0.01 for both compounds). The differential effect on tumor, and the magnitude of the radiosensitization, suggest that further purified or synthetic versions of this extract may be useful not only in vascular-related diseases but also in cancer therapy.

Phenacetin O-deethylation in extrahepatic tissues of rats

Phenacetin O-deethylation is a marker reaction of CYP450 1A2 activity. The drug-metabolizing enzyme is constitutively expressed in liver. In this study, an in vivo rat model for assessment of extrahepatic metabolism was used to investigate phenacetin O-deethylation and the alterations in the disposition of phenacetin due to the loss of liver function. Rats were divided into the model and normal control groups. The model was established according to our previously described method. The concentrations of phenacetin and its major metabolites acetaminophen, glucuronate-acetaminophen and sulfate-acetaminophen in plasma and urine were determined by HPLC. 30 min after intravenous administration of 0.16% phenacetin 10 mg x kg(-1), plasma acetaminophen in the model group was only 3.6% of that in the control group (0.09+/-0.04 microg x mL(-1) vs 2.49+/-0.85 microg x mL(-1), n = 8). 30 min after intragastric injection of 0.4% phenacetin 30 mg x kg(-1), plasma acetaminophen formation was very slight, about 8.6% of plasma phenacetin in the model group (0.74+/-0.43 microg x mL(-1) acetaminophen vs 8.57+/-8.42 microg x mL(-1) phenacetin) and 6.8% in the control group (1.06+/-0.59 microg x mL(-1) acetaminophen vs 15.47+/-7.21 microg x mL(-1) phenacetin, n = 8); no significant differences were observed in plasma phenacetin, total acetaminophen and the ratio of acetaminophen to phenacetin between control and model groups. In the urine collected for 3 h after intravenous administration of 0.16% phenacetin 10 mg x kg(-1), the total recovery of acetaminophen (as free, glucuronate- and sulfate-acetaminophen ) in the model group was 4.6% of that in the control group (4.47+/-4.27 microg vs 96.63+/-8.50 microg, n = 6), but phenacetin recovery in the model group was 9 times higher than that in the control group (15.03+/-17.72 microg vs 1.66+/-0.50 microg). The results indicate that phenacetin O-deethylation in the extrahepatic tissues and the first-pass metabolism of the probe compound seem to be negligible in rats, but the renal excretion of phenacetin, as a compensation, dramatically increases in model rats.

Tomographic Small-Animal Imaging Using a High-Resolution Semiconductor Camera

We have developed a high-resolution, compact semiconductor camera for nuclear medicine applications. The modular unit has been used to obtain tomographic images of phantoms and mice. The system consists of a 64 x 64 CdZnTe detector array and a parallel-hole tungsten collimator mounted inside a 17 cm x 5.3 cm x 3.7 cm tungsten-aluminum housing. The detector is a 2.5 cm x 2.5 cm x 0.15 cm slab of CdZnTe connected to a 64 x 64 multiplexer readout via indium-bump bonding. The collimator is 7 mm thick, with a 0.38 mm pitch that matches the detector pixel pitch. We obtained a series of projections by rotating the object in front of the camera. The axis of rotation was vertical and about 1.5 cm away from the collimator face. Mouse holders were made out of acrylic plastic tubing to facilitate rotation and the administration of gas anesthetic. Acquisition times were varied from 60 sec to 90 sec per image for a total of 60 projections at an equal spacing of 6 degrees between projections. We present tomographic images of a line phantom and mouse bone scan and assess the properties of the system. The reconstructed images demonstrate spatial resolution on the order of 1-2 mm.

Expression of liver cancer associated gene HCCA3

AIM: To study and clone a novel liver cancer related gene, and to explore the molecular basis of liver cancer genesis.

METHODS: Using mRNA differential display polymerase chain reaction (DDPCR), we investigated the difference of mRNA in human hepatocellular carcinoma (HCC) and paired surrounding liver tissues, and got a gene probe. By screening a human placenta cDNA library and genomic homologous extend, we obtained a full-length cDNA named HCCA3. We analyzed the expression of this novel gene in 42 pairs of HCC and the surrounding liver tissues, and distribution in human normal tissues by means of Northern blot assay.

RESULTS: A full-length cDNA of liver cancer associated gene HCCA3 has been submitted to the GeneBank nucleotide sequence databases (Accession No. AF276707). The positive expression rate of this gene was 78.6% (33/42) in HCC tissues, and the clinical pathological data showed that the HCCA3 was closely associated with the invasion of tumor capsule (P = 0.023) and adjacant small metastasis satellite nodules lesions (P = 0.041). The HCCA3 was widely distributed in the human normal tissues, which was intensively expressed in lungs, brain and colon tissues, while lowly expressed in the liver tissues.

CONCLUSION: A novel full-length cDNA was cloned and differentiated, which was highly expressed in liver cancer tissues. The high expression was closely related to the tumor invasiveness and metastasis, that may be the late heredited change in HCC genesis.

Determination of random- and blockwise-type de-esterified pectins by capillary zone electrophoresis

Capillary zone electrophoresis (CZE) was employed to determine the correlations between migration time and degree of esterification (DE) of pectinesterase-de-esterified pectins (PDPs) and alkaline-de-esterified pectins (ADPs) using 50 mM phosphate buffer (pH 6.5) as carrier electrolyte solution and 15 KV as applied voltage. Results showed that pectins with higher DEs exhibited shorter migration times. Linear correlation (r = 0.995) between migration time and DE of ADPs was observed, whereas down-curve correlation in PDPs was observed, regardless of the capillary length used (effective length, 30 and 60 cm). In addition, PDP appeared to migrate faster than ADP with the same DE under the same experimental conditions.

Interleukin-1beta and interleukin-1 receptor antagonist gene polymorphisms in rheumatoid arthritis

The purpose of this study was to evaluate if IL-1beta (IL-1beta promoter and IL-1beta exon 5) and IL-1receptor antagonist (IL-1Ra) gene polymorphisms act as markers of susceptibility to or severity of RA. The study included 104 RA patients and 103 normal controls. No significant difference was observed in the cytokine allelic frequencies of IL-1beta promoter and IL-1beta exon 5 between patients with RA and healthy controls. In addition, there was no significant association in the cytokine carriage rates of I and II allele of IL-1Ra between RA patients and healthy controls. In contrast, the IV allele of IL-1Ra was significantly increased in RA patients with low inflammatory activity (P=0.03). This study indicated that allelic frequency and carriage rate of IL-1beta (IL-1beta promoter and IL-1beta exon 5) and IL-1Ra (I and II allele) do not differ significantly between normal controls and RA patients in Taiwan. However, the carriage rate of IV allele of IL-1Ra was high in the RA patients with low inflammatory activity.

Identification and characterization of a novel human hepatocellular carcinoma-associated gene

To investigate liver cancer-associated genes and to explore the molecular basis of liver cancer genesis, we have cloned a novel hepatocellular carcinoma (HCC)-related gene with a transcript of 2520 base pairs in length named HCCA2 by mRNA differential display polymerase chain reaction (DDPCR) and screening a placenta cDNA library. No significant homologous protein with known genes was found. Western blot analysis showed that HCCA2 could be expressed in transfected 293 cells. Northern hybridization analysis showed that HCCA2 mRNA was expressed in 79% (34/43) patients with HCC, most of whom had significantly high expression in HCC tissues, while not expressed in corresponding noncancerous liver tissues. The clinical pathological data showed that the HCCA2 was significantly associated with the invasion of tumour capsule (P = 0.0007) and the expression of ki-67 protein (P = 0.0022). Immunohistochemical staining confirmed that the HCCA2 protein was localized in cytoplasm of liver cancer tissues. According to amino acid analysis of the protein and its localization, it may play a role in a cascade of intracellular signal transduction because the protein was characterized with two Src homology 3 (SH3) binding-domains and several functional motifs of phosphorylation.

Flow cytometry compared with indirect immunofluorescence for rapid detection of dengue virus type 1 after amplification in tissue culture

Dengue virus (DV) was detected early in infected mosquito C6/36 cells by using indirect immunofluorescence (IF) in conjunction with flow cytometry. Three fixation-permeabilization methods and three DV serotype 1 (DEN-1)-specific monoclonal antibodies, 8-8 (anti-E), 16-4 (anti-NS1), and 15F3-1 (anti-NS1), were evaluated for the detection of DEN-1 in infected C6/36 cells. We found that these three monoclonal antibodies were capable of detecting DV in C6/36 cells as early as 24 h postinoculation by using a conventional indirect IF stain. Both 8-8 and 16-4 detected DV earlier and showed a greater number of DV-positive cells than 15F3-1. In flow cytometry, 3% paraformaldehyde plus 0.1% Triton X-100 with 16-4, the best fixation-permeabilization method for testing DV, showed higher sensitivity (up to 1 PFU) than indirect IF stain. The higher sensitivity of 16-4 in detecting DEN-1 was found with both IF and flow cytometry. Flow cytometry, which had a sensitivity similar to that of nested reverse transcription-PCR, was more sensitive in detecting DV in the infected mosquito cells 10 h earlier than the conventional IF stain. When clinical specimens were amplified in mosquito C6/36 cells and then assayed for DV using flow cytometry and conventional virus isolation at day 7 postinfection, both methods had 97.22% (35 out of 36) agreement. Moreover, among 12 positive samples which were detected by conventional culture method, the flow cytometry assay could detect DV in 58.33% (7 out of 12) of samples even at day 3 postinfection. In conclusion, both monoclonal antibodies 8-8 and 16-4 can be used for the early detection of DEN-1-infected C6/36 cells, with 16-4 (anti-NS1) being the best choice for the rapid diagnosis of DV by both the IF staining and flow cytometry methods.

Interleukin-1beta gene and receptor antagonist gene polymorphisms in patients with calcium oxalate stones

Interleukin-1 (IL-1) might play a role in the process of bone loss and hypercalciuria and is therefore considered to be involved in the formation of urinary stones. The aim of this study is to test whether the IL-1beta promoter region, exon 5 region and IL-1 receptor antagonist gene intron 2 polymorphisms could be genetic markers for the susceptibility to the formation of urinary stones. A control group of 152 healthy people and a group of 105 patients with recurrent calcium oxalate stone were examined in this study. Polymerase chain reaction (PCR) analyzed the variable number tandem repeats at intron 2 of the IL-1Ra gene for the polymorphisms. PCR-based restriction analysis was done for the IL-1beta gene polymorphisms of the promoter region and exon 5 by the endonucleases Ava I and Taq I, respectively. The polymorphisms studied in the IL-1beta genes did not reveal a strong association with calcium oxalate stone disease when compared with the control group (promoter region by chi-square test, P=0.627: exon 5 region by Fisher's exact test, P = 0.403). Only two frequent alleles of the IL-1Ra gene corresponding to one and two copies of an 86-bp sequence repeat were identified by PCR. The result revealed significant differences between control individuals and stone patients (P < 0.01. Fisher's exact test). In addition, the frequency of the type I allele in the stone group (99.0%) was higher than in the control group (94.0%). The odds ratio for the type I allele of the IL-1Ra gene in calcium oxalate stone disease is 6.041 (95% CI: 1.683 approximately 21.687). There is an association between urolithiasis and polymorphism in the IL-1Ra gene. No significant difference was found when dividing the stone patients into groups with normocalciuria and hypercalciuria in relation to these genetic polymorphisms. Further studies of the type I allele of the IL-IRa gene are worthwhile because of its correlation with stone disease. In our study, neither the IL-1beta promoter region nor the exon 5 polymorphisms were significantly different when comparing control subjects and calcium oxalate stone patients.

The association of androgen- and oestrogen-receptor gene polymorphisms with urolithiasis in men

OBJECTIVE

To evaluate the association of urolithiasis with polymorphic microsatellite (encoding cytosine, adenine, and guanine, CAG) repeats in the exon 1 region of the androgen receptor (AR) gene and thymine/adenine (TA) repeats in the oestrogen receptor (ER).

PATIENTS AND METHODS

Patients with urolithiasis (149) and a group of normal controls (102) were examined and compared. The CAG repeats of the AR gene and TA repeats of the ER gene were detected by polymerase chain reaction. The CAG repeats ranged from 171 bp (10 CAG repeats with 141 bp of amplified flanking sequences) to 270 bp (43 CAG repeats). The TA repeats ranged from 160 bp to 194 bp. Associations between calcium oxalate stone disease and the CAG repeats in AR gene and TA repeats in ER gene were then evaluated. The results were classified according to sex and peaks in allelic frequency distribution.

RESULTS

There was a significant difference between the male stone patients and the normal controls in the distribution of CAG repeats in the AR gene. Both groups showed a high percentage of 21-repeats in the allelic distribution, at 17 (16%) and 20 (37%) in stone patients and normal controls, respectively. The results indicate that 21-CAG repeats might be related to a lower risk of stone formation in men (P < 0.05). In the ER gene, the peak allelic distribution of TA repeats was 14, showing a significant difference between male stone patients and the normal control subjects (P < 0.01). There were no statistical differences between female stone patients and the control subjects in either the AR or the ER gene.

CONCLUSION

Urolithiasis among men appears to be associated with AR gene CAG repeat and ER gene TA repeat polymorphisms, whereas there was no significant association among female stone patients. These sex hormone receptors seem to be related to the higher incidence of stone formation among men.

Change in particle size of pectin reacted with pectinesterase isozymes from pea (Pisum sativum L.) sprout

Four pectinesterase (PE) isozymes were isolated by CM-Sepharose CL-6B chromatography from etiolated pea (Pisum sativum L.) sprouts and then reacted with citrus pectin (degree of esterification = 68%, 30-100 kDa) to observe the change in pectin particle size using a laser particle size analyzer. After incubation of a pectin-PE mixture (pH 6.5) at 30 degrees C for 4 h, PE 1 was observed to catalyze the transacylation reaction most remarkably, increasing the particle size from approximately 50-70 to approximately 250-350 nm, followed by PE 3, PE 2, and PE 4.