[Effects of biologics on psychological status and quality of life in patients with inflammatory bowel disease: a multicenter study]

Objective: To investigate the effects of biologics on psychological status and quality of life in patients with inflammatory bowel disease (IBD). Methods: A cross-sectional survey was conducted in 42 hospitals in 22 provinces (autonomous regions and municipalities directly under the central government) from September 2021 to May 2022. General clinical information and the use of biologics were obtained from adult patients diagnosed with IBD who voluntarily participated in the study. Psychological status was evaluated using the Generalized Anxiety Disorder (GAD-7), Patient Health Questionnaire-9 (PHQ-9), Pittsburgh Sleep Quality Index (PSQI), and Inflammatory Bowel Disease Questionnaire (IBDQ) assessment tools. Counts were analyzed via the Chi-square test, and datasets that were not normally distributed were analyzed via nonparametric tests. P<0.05 was considered statistically significant. Results: A total of 2 478 valid questionnaires were collected. The GAD-7 score of the biologics group was significantly lower than that of the non-use group [6 (2, 9) vs. 7 (3, 10), Z=-3.49, P<0.001]. IBDQ scores [183 (158, 204) vs. 178 (152, 198), Z=-4.11, P<0.001], intestinal symptom scores [61 (52, 67) vs. 58 (49, 65), Z=-5.41, P<0.001], systemic symptom scores [28 (24, 32) vs. 27 (23, 31), Z=-2.37, P=0.018], emotional ability scores [69 (58, 77) vs. 67 (56, 75), Z=-3.58, P<0.001] and social ability scores [26 (22, 29) vs. 25 (22, 29), Z=-2.52, P=0.012] in the biologics group were significantly higher than in the non-use group. GAD-7 scores [5 (2, 9) vs. 6 (3, 10), Z=-3.50, P<0.001] and PSQI scores [6 (4, 9) vs. 6 (4, 9), Z=-2.55, P=0.011] were significantly lower in the group using infliximab than in the group not using it. IBDQ scores were significantly higher in patients using vedolizumab than in those not using it [186 (159, 205) vs. 181 (155, 201), Z=-2.32, P=0.021] and were also significantly higher in the group treated with adalimumab than in the group not treated with adalimumab [187 (159, 209) vs. 181 (155, 201), Z=-2.16, P=0.030]. However, ustekinumab had no significant effect on any of the scores. Conclusion: The use of biologics is strongly associated with improvements in anxiety status and quality of life in IBD patients.

Testosterone use and shorter electrocardiographic QT interval duration in men living with and without HIV

OBJECTIVES

Testosterone usage (T-use) may alter risk factors for sudden cardiac death in men living with HIV (MLWH). Electrocardiographic QT interval prolongation, which could potentiate ventricular arrhythmias, has previously been associated with HIV infection and, separately, with low testosterone levels. We investigated whether T-use shortens the QT interval duration in MLWH and HIV-uninfected men.

METHODS

We utilized data from the Multicenter AIDS Cohort Study, a prospective, longitudinal study of HIV infection among men who have sex with men. Multivariable linear regression analyses were used to evaluate associations between T-use and corrected QT interval (QTc) duration.

RESULTS

Testosterone usage was more common in MLWH compared with HIV-uninfected men (19% vs. 9%). In a multivariable regression analysis, T-use was associated with a 5.7 ms shorter QT interval [95% confidence interval (CI): -9.5 to -1.9; P = 0.003). Furthermore, stronger associations were observed for prolonged duration of T-use and recent timing of T-use.

CONCLUSIONS

This study is the first known analysis of T-use and QTc interval in MLWH. Overall, our data demonstrate that recent T-use is associated with a shorter QTc interval. Increased T-use duration above a threshold of ≥ 50% of visits in the preceding 5 years was associated with a shorter QTc interval while lesser T-use duration was not.

[Relationship of DNMT3b expression and SEPT9 methylation in theprogression of colorectal carcinogenesis]

Objective: To investigate the relationship between the expression of DNA methyltransferase 3b (DNMT3b) and the methylation of SEPT9 gene, and their application prospects in the diagnosis and treatment of colorectal cancer. Methods: Seventy-five cases of colorectal cancer and adjacent tissues, 68 cases of colorectal high-grade internal neoplasia tissues (referred to as precancerous tissues) and high-grade internal adjacent neoplasia tissues (referred to as adjacent precancerous tissues) were collected. Pyrosequencing was used to detect the methylationlevel of SETP9. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to examine the mRNA expressionof SEPT9 and immunohistochemistry(IHC) was applied to detect the protein expressions of SETP9 and DNMT3b. Liposome-mediated method was used to transfect DNMT3b siRNA and negative control siRNA into HT-29 cells. Five groups including DNMT3b siRNA 15 nmol/L group, DNMT3b siRNA 30 nmol/L group, negative control siRNA 15 nmol/L group, negative control siRNA 30 nmol/L group and blank control group were set up. Pyrosequencing was applied to determine the methylation level of SEPT9 and mRNA expression of DNMT3b in each group. Results: The methylation rates of SEPT9 gene in colorectal cancer tissues, adjacent tissues, precancerous tissues and adjacent precancerous tissues were (76.8±6.5)%, (14.4±2.6)%, (34.6±5.0)% and (7.4±1.2)%, respectively, which was highest in colorectal cancer tissue (P<0.001). The relative expressions of SEPT9 mRNA were 0.18±0.03, 0.89±0.41, 0.69±0.41 and 1.01±0.21, respectively, which was lowest in colorectal cancer tissue (P<0.001), while there were no statistically significant differences in adjacent tissues, precancerous tissues and adjacent precancerous tissues (P>0.05). The positive rates of SEPT9 protein expression were 12.0% (9/75), 53.3% (40/75), 55.1% (38/69) and 62.3% (43/69), which was lowest in the colorectal cancer tissue (P<0.001), while there were no statistically significant differences in the adjacent group, precancerous group and adjacent precancerous group (P>0.016 7). The positive rates of DNMT3b protein expression were 56.3% (45/75), 26.7% (20/75), 46.4% (32/69) and 33.3% (23/69), respectively, which was highest in colorectal cancer tissue (P<0.001), while without statistically significant difference from the precancerous tissue (P>0.016 7). Experiments in vitro showed that DNMT3b mRNA expression was lowest in DNMT3b siRNA 30 nmol/L group among five groups and was statistically different from other groups (all P<0.05). Meanwhile, the methylationrate of SEPT9 gene was lowest in this group, but without statistically significant difference from the DNMT3b siRNA 15 nmol/L group (P>0.05). Conclusions: The expression of DNMT3b is significantly correlated with the methylation level of SEPT9 gene in different stages of colorectal cancer. The high expression of DNMT3b may be an important molecular event before SEPT9 gene methylation and it may have an important potential application value in the diagnosis and treatment of early colorectal cancer.

Enhancing Efficiency and Stability of Photovoltaic Cells by Using Perovskite/Zr-MOF Heterojunction Including Bilayer and Hybrid Structures

In this study, the effectiveness of using a perovskite/Zr-metal-organic frameworks (MOFs) heterojunction in realizing efficient and stable inverted p-i-n perovskite solar cells (PVSCs) is demonstrated. Two types of Zr-MOFs, UiO-66 and MOF-808, are investigated owing to their respectable moisture and chemical stabilities. The MOFs while serving as an interlayer in conjunction with the perovskite film are shown to possess the advantages of UV-filtering capability and enhancing perovskite crystallinity. Consequently, the UiO-66/MOF-808-modified PVSCs yield enhanced power conversion efficiencies (PCEs) of 17.01% and 16.55%, outperforming the control device (15.79%). While further utilizing a perovskite/Zr-MOF hybrid heterojunction to fabricate the devices, the hybrid MOFs are found to possibly distribute over the perovskite grain boundary providing a grain-locking effect to simultaneously passivate the defects and to reinforce the film's robustness against moisture invasion. As a result, the PCEs of the UiO-66/MOF-808-hybrid PVSCs are further enhanced to 18.01% and 17.81%, respectively. Besides, over 70% of the initial PCE is retained after being stored in air (25 °C and relative humidity of 60 ± 5%) for over 2 weeks, in contrast to the quick degradation observed for the control device. This study demonstrates the promising potential of using perovskite/MOF heterojunctions to fabricate efficient and stable PVSCs.

Enhanced Charge Collection in MOF-525-PEDOT Nanotube Composites Enable Highly Sensitive Biosensing

With the aim of a reliable biosensing exhibiting enhanced sensitivity and selectivity, this study demonstrates a dopamine (DA) sensor composed of conductive poly(3,4-ethylenedioxythiophene) nanotubes (PEDOT NTs) conformally coated with porphyrin-based metal-organic framework nanocrystals (MOF-525). The MOF-525 serves as an electrocatalytic surface, while the PEDOT NTs act as a charge collector to rapidly transport the electron from MOF nanocrystals. Bundles of these particles form a conductive interpenetrating network film that together: (i) improves charge transport pathways between the MOF-525 regions and (ii) increases the electrochemical active sites of the film. The electrocatalytic response is measured by cyclic voltammetry and differential pulse voltammetry techniques, where the linear concentration range of DA detection is estimated to be 2 × 10-6-270 × 10-6 m and the detection limit is estimated to be 0.04 × 10-6 m with high selectivity toward DA. Additionally, a real-time determination of DA released from living rat pheochromocytoma cells is realized. The combination of MOF5-25 and PEDOT NTs creates a new generation of porous electrodes for highly efficient electrochemical biosensing.

Ultrasound-Guided Percutaneous Radiofrequency Lesioning When Treating Recalcitrant Plantar Fasciitis: Clinical Results

PURPOSE

We evaluated the effects of ultrasound (US)-guided percutaneous radiofrequency thermal lesioning (RTL) and the impact of obesity when treating patients with recalcitrant plantar fasciitis.

MATERIALS AND METHODS

30 consecutive patients were enrolled. The visual analog scale (VAS), American Orthopedic Foot-Ankle Society (AOFAS) Ankle-Hindfoot Score, and plantar fascia thickness measured using US were recorded at baseline and at follow-up 1, 3, 6, and 12 months after surgery under local anesthesia.

RESULTS

12 patients in the obese (BMI ≥ 30 kg/m(2)) group and 18 patients in the non-obese group. There were significant postoperative decreases in VAS scores and in fascial thickness, and an increase in the AOFAS scores (all p < 0.001). The obese group showed delayed pain and functional improvement within the first 3 months after the index procedure (p < 0.01). Significant pain reduction and functional improvement were apparent earlier (after 1 month, p < 0.001) in the non-obese group than in the obese group (after 3 months, p < 0.05). Fascia thickness was positively correlated with the VAS score and negatively correlated with the AOFAS score (both p < 0.001).

CONCLUSION

US should be regarded as a useful objective tool to guide RTL and to monitor the effectiveness of treatment. US-guided percutaneous RTL for recalcitrant PF is a minimally invasive treatment option that yields satisfactory results. Therefore, it should at least be considered before using more invasive procedures. Moreover, obesity leads to delayed improvement but does not affect overall outcome after 12 months. Plantar fascial thickness was correlated with VAS and AOFAS scores.

Screening and identification of peritoneal metastasis-related genes of gastric adenocarcinoma using a cDNA microarray

With the aim of identifying peritoneal metastasis-related genes in gastric cancer, we performed a broad analysis of differential gene expression between the parental cell line GC9811 and its highly metastatic peritoneal counterpart, cell line GC9811-P. Two fluorescent cDNA probes, labeled with Cy3 and Cy5 dyes, were prepared from GC9811 and GC9811-P mRNA samples by the reverse transcription method. The two color probes were then mixed and hybridized to a cDNA chip constructed with double-dots from 11,901 human genes; this was scanned at two wavelengths. The experiment was repeated twice. In GC9811-P cells, 218 genes were upregulated and 30 genes were downregulated compared with the parental cell lines. Some selected genes were confirmed by RT-PCR and Western blot; we found that S100A4 and CTNNB1 were upregulated and PTEN was downregulated in GC9811-P cells. Identification of these differentially expressed genes could contribute to disclose the molecular mechanisms involved and provide new targets for therapeutic intervention to avoid peritoneal dissemination of gastric adenocarcinoma.

Biostabilization assessment of MSW co-disposed with MSWI fly ash in anaerobic bioreactors

Municipal solid waste incinerator (MSWI) fly ash has been examined for possible use as landfill interim cover. For this aim, three anaerobic bioreactors, 1.2m high and 0.2m in diameter, were used to assess the co-digestion or co-disposal performance of MSW and MSWI fly ash. Two bioreactors contained ratios of 10 and 20 g fly ash per liter of MSW (or 0.2 and 0.4 g g(-1) VS, that is, 0.2 and 0.4 g fly ash per gram volatile solids (VS) of MSW). The remaining bioreactor was used as control, without fly ash addition. The results showed that gas production rate was enhanced by the appropriate addition of MSWI fly ash, with a rate of approximately 6.5l day(-1)kg(-1)VS at peak production in the ash-added bioreactors, compared to approximately 4l day(-1)kg(-1)VS in control. Conductivity, alkali metals and VS in leachate were higher in the fly ash-added bioreactors compared to control. The results show that MSW decomposition was maintained throughout at near-neutral pH and might be improved by release of alkali and trace metals from fly ash. Heavy metals exerted no inhibitory effect on MSW digestion in all three bioreactors. These phenomena indicate that proper amounts of MSWI fly ash, co-disposed or co-digested with MSW, could facilitate bacterial activity, digestion efficiency and gas production rates.

Solubility of heavy metals added to MSW

This paper aims to investigate the six heavy metal levels (Cd, Cr, Cu, Pb, Ni and Zn) in municipal solid waste (MSW) at different pHs. It intends to provide the baseline information of metals solubility in MSW co-disposed or co-digested with MSW incinerator ashes in landfill or anaerobic bioreactors or heavy metals contaminated in anaerobic digesters. One milliliter (equal to 1mg) of each metal was added to the 100ml MSW and the batch reactor test was carried out. The results showed that higher HNO3 and NaOH were consumed at extreme pH of 1 and 13 compared to those from pH 2 to 11 due to the comparably higher buffer capacity. Pb was found to have the least soluble level, highest metal adsorption (%) and highest partitioning Kd (lg(-1)) between pH 3 and 12. In contrast, Ni showed the highest soluble level, lowest metal adsorption (%) and lowest Kd (lg(-1)) between pH 4 and 12. Except Ni and Cr, other four metals seemed to show the amphibious properties as comparative higher solubility was found in the acidic and basic conditions.

Asia Pacific consensus recommendations for colorectal cancer screening

Colorectal cancer (CRC) is rapidly increasing in Asia, but screening guidelines are lacking. Through reviewing the literature and regional data, and using the modified Delphi process, the Asia Pacific Working Group on Colorectal Cancer and international experts launch consensus recommendations aiming to improve the awareness of healthcare providers of the changing epidemiology and screening tests available. The incidence, anatomical distribution and mortality of CRC among Asian populations are not different compared with Western countries. There is a trend of proximal migration of colonic polyps. Flat or depressed lesions are not uncommon. Screening for CRC should be started at the age of 50 years. Male gender, smoking, obesity and family history are risk factors for colorectal neoplasia. Faecal occult blood test (FOBT, guaiac-based and immunochemical tests), flexible sigmoidoscopy and colonoscopy are recommended for CRC screening. Double-contrast barium enema and CT colonography are not preferred. In resource-limited countries, FOBT is the first choice for CRC screening. Polyps 5-9 mm in diameter should be removed endoscopically and, following a negative colonoscopy, a repeat examination should be performed in 10 years. Screening for CRC should be a national health priority in most Asian countries. Studies on barriers to CRC screening, education for the public and engagement of primary care physicians should be undertaken. There is no consensus on whether nurses should be trained to perform endoscopic procedures for screening of colorectal neoplasia.

Cloning and nucleotide sequencing of the second internal transcribed spacer of ribosomal DNA for three species of Eimeria from chickens in Taiwan

Coccidiosis of chickens caused by protozoan parasites of the genus Eimeria (Coccidia: Eimeriidae) is an enteric disease that results in great economic losses throughout the world, including Taiwan. Using polymerase chain reaction (PCR) with primers specific for the second internal transcribed spacer (ITS-2) of ribosomal DNA (rDNA), three species of Eimeria, E. tenella, E. maxima, and E. acervulina have been successfully characterised from chickens in Taiwan. The sizes of PCR products from various isolates representing these three species were between 370 and 580 base pairs (bp). After cloning and sequencing of the PCR products, high nucleotide sequence identity (96.8-100%) was observed within a species. In addition, ITS-2 nucleotide sequences for E. tenella had higher homology (98.5-99.3%) than E. maxima (81.6-96.5%) when compared with appropriate sequences deposited in GenBank. To our knowledge, this is the first report of a 412-bp ITS-2 sequence for E. acervulina from chickens.

Predicting postoperative nausea and vomiting with the application of an artificial neural network

BACKGROUND

Several medications have proved to be useful in preventing postoperative nausea and vomiting (PONV). However, routine antiemetic prophylaxis is not cost-effective. We evaluated the accuracy and discriminating power of an artificial neural network (ANN) to predict PONV.

METHODS

We analysed data from 1086 in-patients who underwent various surgical procedures under general anaesthesia without antiemetic prophylaxis. Predictors used for ANN training were selected by computing the value of chi(2) statistic and information gain with respect to PONV. The configuration of the ANN was chosen by using a software tool. Then the training of the ANN was performed based on data from a training set (n=656). Testing validation was performed with the remaining patients (n=430) whose outcome regarding PONV was unknown to the ANN. Area under the receiver operating characteristic (ROC) curves were used to quantify predictive performance. ANN performance was compared with those of the Naïve Bayesian classifier model, logistic regression model, simplified Apfel score and Koivuranta score.

RESULTS

ANN accuracy was 83.3%, sensitivity 77.9% and specificity 85.0% in predicting PONV. The areas under the ROC curve follow: ANN, 0.814 (0.774-0.850); Naïve Bayesian classifier, 0.570 (0.522-0.617); logistic regression, 0.669 (0.623-0.714); Koivuranta score, 0.626 (0.578-0.672); simplified Apfel score, 0.624 (0.576-0.670). ANN discriminatory power was superior to those of the other predicting models (P<0.05).

CONCLUSIONS

The ANN provided the best predictive performance among all tested models.

Effects of somatostatin, octreotide and pitressin plus nitroglycerine on systemic and portal haemodynamics in the control of acute variceal bleeding

To examine the haemodynamic effects of somatostatin (SS) and octreotide (OC) versus pitressin plus nitroglycerine (PN) in the control of variceal bleeding, 224 patients with acute oesophageal and gastric variceal haemorrhage were randomly divided into three groups and treated with SS, OC and PN; they also had their Doppler ultrasound parameters measured before, during and after treatment. The success rates of bleeding control in the SS (80.9%, 86.8% and 89.7%, p<0.001) and OC (75.3%, 80.8% and 84.9%, p<0.01) groups were significantly higher than in the PN group (51.8%, 59.0% and 65.1%) at 24, 48 and 72 hours respectively, and the average duration of SS (12.7 + 6.8 h) and OC (13.8 + 8.0 h) was significantly lower than that of PN (24.6 + 15.4 h, p<0.001). Side-effects of SS (7.4%) and OC (8.2%) were less than those of PN (41.0%, p<0.001 and p<0.01). The diameter of portal vein (PVD), velocity of portal vein (PVV), volume of portal blood flow (PVF) and hepatic artery pulsatility index (HA-PI) in all three groups decreased significantly during initial treatment, but recovered when treatment was stopped. Heart rate and cardiac output decreased significantly in patients treated with SS and OC; mean arterial pressure was unchanged. However, heart rate and mean arterial pressure increased, and cardiac output decreased, with PN. Somatostatin and octreotide were more effective than pitressin plus nitroglycerine in patients with acute variceal haemorrhage, with fewer side-effects, and may decrease PVF and portal vein pressure through reduction of cardiac output and dilatation of the visceral blood vessels.

The value of MG7 antigen in predicting cancerous change in dysplastic gastric mucosa

The aim of this study was to ascertain whether MG7Ag is a useful predictor of evolution of gastric dysplasia to carcinoma. A total of 1090 patients with confirmed dysplasia were stained immunohistochemically with MG7 monoclonal antibody by the ABC method. A prospective follow-up study was undertaken on 19 patients with MG7Ag positive staining and 16 with MG7 negative staining over a period of 10-78 months. The expression of MG7Ag was also compared in another two groups by conducting retrospective studies. One group showed an evolution into gastric cancer over 2-4 years, the other did not. Quantitative analysis of MG7Ag expression was carried out on the last two groups. The receiver operating characteristic curve and Youden index were used to assess the best critical value for MG7Ag. MG7Ag was found positive in 456/1090 cases (41.8%) with dysplasia. Prospective follow-up of 35 patients showed that 6/19 patients with MG7Ag positive staining developed gastric cancer, but there were no carcinomatous changes in 16 patients with MG7 negative staining. The results of MG7Ag expression in 72 cases with retrospective follow-up showed there were 24 with positive immunostaining among 34 cancerous cases (70.6%), and only 7 in 38 non-cancerous cases (18.4%) (p<0.01). Image analysis showed that an average MG7Ag density index ++0.19 could be regarded as the critical value for high risk of gastric mucosa with dysplasia evolving to cancer. Positive MG7Ag expression in gastric mucosa of patients with dysplasia, especially in cases with a density index ++0.19, was an indicator of high risk of malignant change.

Characteristics of community-acquired methicillin-resistant Staphylococcus aureus in infants and children without known risk factors

This retrospective study sought to determine the characteristics of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infections in patients younger than 18 years without known risk factors who were treated at a teaching hospital in central Taiwan. Epidemiological and clinical data were collected from medical charts. Possible risk factors included hospitalization within the past 6 months, transfer from other hospitals or nursing homes, and having underlying illness. A total of 173 isolates of community-acquired S. aureus were analyzed. Seventeen (9.8%) of these 173 isolates were methicillin-resistant S. aureus collected from patients without risk factors, 31 (17.9%) were methicillin-resistant S. aureus from patients with risk factors, and the other 125 (72.3%) were methicillin-susceptible S. aureus. Most isolates of community-acquired methicillin-resistant S. aureus collected from patients without risk factors (14/17, 82.4%) were obtained from the infected wounds of skin or soft tissues. Only 4 (23.5%) in 17 patients with isolates resistant to methicillin were prescribed antimicrobial therapy with glycopeptides. Nevertheless, all patients recovered without any long-term sequelae. These results highlight the fact that community-acquired methicillin-resistant S. aureus infections occur frequently in Taiwan among patients who have no established risk factors for this infection.

Polymorphism of flagellin A gene in Helicobacter pylori

AIM: To study the polymorphism of flagellin A genotype and its significance in Helicobacter pylori (H. pylori).

METHODS: As the template, genome DNA was purified from six clinical isolates of H. pylori from outpatients, and the corresponding flagellin A fragments were amplified by polymerase chain reaction. All these products were sequenced. These sequences were compared with each other, and analyzed by software of FASTA program.

RESULTS: Specific PCR products were amplified from all of these H. pylori isolates and no length divergence was found among them. Compared with each other, the highest ungapped identity is 99.10%, while the lowest is 94.65%. Using FASTA program, the alignments between query and library sequences derived from different H. pylori strains were higher than 90%.

CONCLUSION: The nucleotide sequence of flagellin A in H. pylori is highly conservative with incident divergence. This information may be useful for gene diagnosis and further study on flagellar antigen phenotype.

Relationship between genotype and phenotype of flagellin C in Salmonella

AIM: To discover the relationship between the genotype and antigen serotype of flagellin C among Salmonella strains.

METHODS: Fragment of Salmonella flagellin C in plasmid pLS408 was cloned, sequenced and compared with the corresponding sequence in other strains. Salmonella strains including two typhi strains, one paratyphoid strain, one enteritidis and one typhimurium strain were isolated from outpatients. Genome DNA was purified respectively from these clinical isolates, then the corresponding flagellin C fragment was amplified by polymerase chain reaction, and the amplification products were analyzed by agarose gel electrophoresis.

RESULTS: The cloned fragment includes 582 nucleotides encoding the variable region and partial conservative region of Salmonella flagellin C in plasmid pLS408. With comparison to the corresponding sequences reported previously, there is only a little difference from other strains with the same flagellar serotype in both nucleotide and amino acid level. Specific PCR products were amplified in Salmonella strains with flagellar serotype H-1-d including S. muenchen, typhi and typhimurium, but not in S. paratyphoid C or S. enteritidis strains.

CONCLUSION: In this experiment, the specificity of nucleotide sequence could be found in flagellin C central variable regions as it exists in flagellar serotypes in Salmonella. It may be helpful to developing a rapid, sensitive, accurate and PCR-based method to detect Salmonella strains with serotype H-1-d.

Towards more active biocatalysts in organic media: increasing the activity of salt-activated enzymes

The activation of freeze-dried subtilisin Carlsberg (SC) in hexane has been systematically studied and partially optimized with respect to the freezing method, the addition of inorganic salts and lyoprotectants, the initial concentration and final weight percent of additives, and the amount of water added to the organic solvent. Activity and water content were found to correlate directly with the kosmotropicity of the activating salt (kosmotropic salts bind water molecules strongly relative to the strength of water-water interactions in bulk solution). Combinations of kosmotropic salts with known lyoprotectants such as poly(ethylene glycol) (PEG) and sugars did not yield an appreciably more active catalyst. However, the combination of the kosmotropic sodium acetate with the strongly buffering sodium carbonate activated the enzyme more than the individual additives alone. Enzyme activity was enhanced further by the addition of small amounts of water to the organic solvent. Under optimal conditions, enzyme activity in hexane was improved over 27,000-fold relative to the salt-free enzyme, reaching a catalytic efficiency that was within one order of magnitude of k(cat)/K(m) for hydrolysis of the same substrate in aqueous buffer. Further activation to attain even higher catalytic efficiencies may be possible with additional optimization.

Role of motility in embryonic development I: Embryo movements and amnion contractions in the chick and the influence of illumination

This study provides a quantitative analysis of the active movements of the chick embryo and of the contractions of the amnion over the entire developmental period of 21 days. Four types of embryo movements are distinguished. The motor activity of the embryo shows two characteristic peaks, with maximum contraction frequencies on the 12th and on the 16th day. In contrast, the amnion activity is higher at earlier stages and decreases as the body activity increases. The amnion activity is largely independent of the body activity. Illumination has a strong influence on embryo movements. It is shown that increases of light intensity affect the patterns of activity of both the embryo and the amnion. While the effect of light on the embryo can be interpreted as being transmitted via the optic system, the mechanism of the amniotic response is unclear. The results suggest that the amnion itself may be sensitive to light. J. Exp. Zool. (Mol. Dev. Evol.) 291:186-194, 2001.

Cryopreservation of gander semen

1. The effect of dimethylacetamide (DMA) and dimethyl sulphoxide (DMSO) on the cryopreservation of gander semen were investigated. An improved survival rate of spermatozoa after freeze-thawing was obtained when semen was frozen by a fast-freezing procedure on dry ice with 9% DMA as the cryoprotectant. 2. Gander semen, which was frozen during mid season, was tested for fertilising ability in different times of the season. The percentage of fertility during d 3 to d 9 after 2 consecutive inseminations was 68% to 95%, depending on the date of artificial insemination.

The surface motion due to a line force or dislocation within an anisotropic elastic half-space

An explicit solution of the surface displacements due to a line force or a line dislocation within an anisotropic half-space is presented. The surface displacements are derived from the solution corresponding to a suddenly applied surface line force using the reciprocal theorem. The solution is in a closed form for isotropic media. For anisotropic solids, only an eigenvalue problem needs to be solved numerically for a given time and position to calculate the surface response. Numerical results are given for silicon.

Residues in the 1A rod domain segment and the linker L2 are required for stabilizing the A11 molecular alignment mode in keratin intermediate filaments

Both analyses of x-ray diffraction patterns of well oriented specimens of trichocyte keratin intermediate filaments (IF) and in vitro cross-linking experiments on several types of IF have documented that there are three modes of alignment of pairs of antiparallel molecules in all IF: A11, A22 and A12, based on which parts of the major rod domain segments are overlapped. Here we have examined which residues may be important for stabilizing the A11 mode. Using the K5/K14 system, we have made point mutations of charged residues along the chains and examined the propensities of equimolar mixtures of wild type and mutant chains to reassemble using as criteria: the formation (or not) of IF in vitro or in vivo; and stabilities of one- and two-molecule assemblies. We identified that the conserved residue Arg10 of the 1A rod domain, and the conserved residues Glu4 and Glu6 of the linker L2, were essential for stability. Additionally, conserved residues Lys31 of 1A and Asp1 of 2A and non-conserved residues Asp/Asn9 of 1A, Asp/Asn3 of 2A, and Asp7 of L2 are important for stability. Notably, these groups of residues lie close to each other when two antiparallel molecules are aligned in the A11 mode, and are located toward the ends of the overlap region. Although other sets of residues might theoretically also contribute, we conclude that these residues in particular engage in favorable intermolecular ionic and/or H-bonding interactions and thereby may play a role in stabilizing the A11 mode of alignment in keratin IF.

Cyclooxygenase (COX) 1 and 2 in normal, inflamed, and ulcerated human gastric mucosa

BACKGROUND AND AIMS

Constitutive cyclooxygenase (COX) 1 is believed to mediate prostaglandin dependent gastric protection. However, gastric mucosa contains cells capable of expressing inducible COX-2. We therefore investigated COX-1 and COX-2 expression, localisation, and activity in normal and abnormal human gastric mucosa.

METHODS

COX-1 and COX-2 distribution was investigated by light and electron microscopic immunohistochemistry and by western blot analysis, and their contribution to prostaglandin (PG)E(2) synthesis using selective enzyme inhibitors.

RESULTS

There was strong parietal cell COX-1 and COX-2 immunoreactivity in all sections and isolated cells, with macrophage and myofibroblast reactivity in some sections. Immunostaining was specifically abolished by antigen absorption. Western blot analysis confirmed COX-1 and 2 expression. COX-1 and COX-2 immunostaining was increased in Helicobacter pylori gastritis, particularly the mid glandular zone and lamina propria inflammatory cells. This was associated with increased ex vivo PGE(2) synthesis (62.4 (13.5) pg/mg v 36.3 (15.5) pg/mg in uninflamed mucosa; p=0. 017) which was significantly inhibited by COX-1 but not COX-2 inhibition. Increased COX-2 immunostaining in macrophages, endothelial cells, and myofibroblasts (with reduced epithelial expression) was seen at the rim of ulcers.

CONCLUSION

COX-2, as well as COX-1, is expressed by normal human gastric mucosa and is increased at the rim of ulcers. Although both are increased with H pylori, COX-1 contributes more than COX-2 to gastric PGE(2) production.

Coiled-coil trigger motifs in the 1B and 2B rod domain segments are required for the stability of keratin intermediate filaments

Many alpha-helical proteins that form two-chain coiled coils possess a 13-residue trigger motif that seems to be required for the stability of the coiled coil. However, as currently defined, the motif is absent from intermediate filament (IF) protein chains, which nevertheless form segmented two-chain coiled coils. In the present work, we have searched for and identified two regions in IF chains that are essential for the stability necessary for the formation of coiled-coil molecules and thus may function as trigger motifs. We made a series of point substitutions with the keratin 5/keratin 14 IF system. Combinations of the wild-type and mutant chains were assembled in vitro and in vivo, and the stabilities of two-chain (one-molecule) and two-molecule assemblies were examined with use of a urea disassembly assay. Our new data document that there is a region located between residues 100 and 113 of the 2B rod domain segment that is absolutely required for molecular stability and IF assembly. This potential trigger motif differs slightly from the consensus in having an Asp residue at position 4 (instead of a Glu) and a Thr residue at position 9 (instead of a charged residue), but there is an absolute requirement for a Glu residue at position 6. Because these 13 residues are highly conserved, it seems possible that this motif functions in all IF chains. Likewise, by testing keratin IF with substitutions in both chains, we identified a second potential trigger motif between residues 79 and 91 of the 1B rod domain segment, which may also be conserved in all IF chains. However, we were unable to find a trigger motif in the 1A rod domain segment. In addition, many other point substitutions had little detectable effect on IF assembly, except for the conserved Lys-23 residue of the 2B rod domain segment. Cross-linking and modeling studies revealed that Lys-23 may lie very close to Glu-106 when two molecules are aligned in the A(22) mode. Thus, the Glu-106 residue may have a dual role in IF structure: it may participate in trigger formation to afford special stability to the two-chain coiled-coil molecule, and it may participate in stabilization of the two-molecule hierarchical stage of IF structure.

Microvascular obstruction and left ventricular remodeling early after acute myocardial infarction

BACKGROUND

The presence of microvascular obstruction (MO) within infarcted regions may adversely influence left ventricular (LV) remodeling after acute myocardial infarction. This study examined whether the extent of MO directly alters the mechanical properties of the infarcted myocardium.

METHODS AND RESULTS

Seventeen dogs underwent 90 minutes of balloon occlusion of the left anterior descending coronary artery, followed by reperfusion. Gadolinium-enhanced perfusion MRI and 3D-tagging were performed 4 to 6 and 48 hours (8 animals) and 10 days (9 animals) after reperfusion. Early increase in LV end-diastolic volume (from 42+/-9 to 54+/-14 mL, P<0.05) between 4 to 6 and 48 hours after reperfusion was predicted by both extent of MO (r=0.89, P<0.01) and infarct size (r=0.83, P<0.01), defined as MRI hypoenhanced and hyperenhanced regions, respectively. Multivariate analysis demonstrated that extent of MO had better and independent value to predict LV volume than overall infarct size. A strong inverse relationship existed between magnitude of first principal strain (r=-0.80, P<0.001) and relative extent of MO within infarcted myocardium. Also, infarcted myocardium involved by extensive areas of MO demonstrated reductions of circumferential (r=-0.61, P<0.01) and longitudinal (r=-0.53, P<0. 05) stretching. Furthermore, significant reductions of radial thickening (9+/-6% versus 14+/-3%, P<0.01) occurred in noninfarcted regions adjacent to infarcts that had increased (>35%) amounts of MO.

CONCLUSIONS

In the early healing phase of acute myocardial infarction, the extent of MO in infarcted tissue relates to reduced local myocardial deformation and dysfunction of noninfarcted adjacent myocardium. Such strain alterations might explain the increased remodeling observed in patients with large regions of MO.

[Electroporation of sperm to introduce foreign DNA into the genome of Pinctada maxima (Jameson)]

Gene transfer was investigated in marine molluscs via electroporated sperm. Sperm of P. maxima (J.) was incubated with linear "all-fish" growth hormone gene (pCAgcGH and pCAgcGHc) for 30 min. Then, mature eggs were in-vitro fertilized with the sperm cells treated with electroporation at 10 kV and 2(7) pulses of six cycles. DNA was extracted from spat and analyzed by PCR and southern blot. The results indicated that the foreign DNA had been transferred into the genome of experimental molluscs. The transgenetic ration was 5.6%, 20% and 50% when 2 micrograms/mL, 6 micrograms/mL and 18 micrograms/mL of foreign DNA was used, respectively. It is suggested that the transferred efficiency is correlated with the amount of the foreign DNA.

Effects of fenoterol and ipratropium on respiratory resistance of asthmatics after tracheal intubation

We have studied the effects of a beta-agonist, fenoterol, and a cholinergic antagonist, ipratropium, on post-intubation total respiratory system resistance (Rrs) in asthmatics who developed increased Rrs after tracheal intubation. Sixteen stable asthmatics in whom Rrs increased after intubation were allocated randomly to receive either 10 puffs of fenoterol (group F) or 10 puffs of ipratropium (group IB) via a metered dose inhaler 5 min after intubation. Anaesthesia was induced and maintained with propofol i.v. Rrs was recorded before treatment and again 5, 15 and 30 min after treatment. Rrs decreased significantly from pretreatment values by mean 53 (SD 8)%, 53 (7)% and 58 (6)% at 5, 15 and 30 min, respectively, in group F, but declined by only 12 (6)%, 15 (4)% and 17 (5)% in group IB. At all times after treatment, patients in the fenoterol group had significantly lower Rrs values than those in the ipratropium group. We conclude that increased Rrs after tracheal intubation in asthmatics can be reduced effectively by treatment with fenoterol. A secondary finding of our study was that even after induction of anaesthesia with propofol, patients with a history of asthma may develop high Rrs.

The mutant growth hormone-releasing hormone (GHRH) receptor of the little mouse does not bind GHRH

The little mouse is a dwarf strain characterized by low levels of GH, pituitary hypoplasia, and an unresponsiveness to treatment with exogenous GHRH. The defect has been mapped to a missense mutation in the GHRH receptor gene that abolishes the function of the receptor, but the mechanism of this inactivation is unknown. Receptor function might be affected at the level of protein expression, maturation and processing, localization to the cell surface, ligand binding, or signaling. In this study, Western blots, using antiserum raised against the GHRH receptor and immunoprecipitation analysis of epitope-tagged receptors, demonstrate that both wild-type and mutant receptor proteins are expressed at equivalent levels in transfected cells. Immunofluorescence analysis of intact and permeabilized cells expressing the epitope-tagged receptors suggests that wild-type and little mouse receptors are similarly localized to the cell surface. A species homologous binding assay was developed and used to show that 125I-mouse GHRH binds with high affinity to the wild-type mouse receptor but not to the little mutant receptor. Consistent with this, the mutant receptor fails to stimulate intracellular cAMP accumulation. Our results demonstrate that the little mutation does not dramatically affect the expression level, glycosylation, or cellular localization of the receptor protein but that it blocks specific GHRH binding, and therefore, signaling does not take place.

Magnetic resonance imaging in acute myocardial infarction

Advances in magnetic resonance imaging (MRI) have led to more widespread utilization of this diagnostic imaging modality in the diagnosis of coronary artery disease. With MRI, the complexity and heterogeneity of myocardial infarcts can be demonstrated. By using this technique, much insight has been gained into the pathophysiologic mechanisms of acute coronary thrombosis and reperfusion. MRI has significant diagnostic potential, particularly if one can combine studies of myocardial function, perfusion, and sodium metabolism with the noninvasive assessment of coronary anatomy and epicardial coronary artery blood flow.

A high molecular weight intermediate filament-associated protein in BHK-21 cells is nestin, a type VI intermediate filament protein. Limited co-assembly in vitro to form heteropolymers with type III vimentin and type IV alpha-internexin

BHK-21 fibroblasts contain type III vimentin/desmin intermediate filament (IF) proteins that typically co-isolate and co-cycle in in vitro experiments with certain high molecular weight proteins. Here, we report purification of one of these and demonstrate that it is in fact the type VI IF protein nestin. Nestin is expressed in several fibroblastic but not epithelioid cell lines. We show that nestin forms homodimers and homotetramers but does not form IF by itself in vitro. In mixtures, nestin preferentially co-assembles with purified vimentin or the type IV IF protein alpha-internexin to form heterodimer coiled-coil molecules. These molecules may co-assemble into 10 nm IF provided that the total amount of nestin does not exceed about 25%. However, nestin does not dimerize with types I/II keratin IF chains. The bulk of the nestin protein consists of a long carboxyl-terminal tail composed of various highly charged peptide repeats. By analogy with the larger neurofilament chains, we postulate that these sequences serve as cross-bridgers or spacers between IF and/or other cytoskeletal constituents. In this way, we propose that direct incorporation of modest amounts of nestin into the backbone of cytoplasmic types III and IV IFs affords a simple yet flexible method for the regulation of their dynamic supramolecular organization and function in cells.