Changing clinical manifestations of Gaucher disease in Taiwan

BACKGROUND

Gaucher disease (GD) is a lysosomal storage disorder characterized by deficient glucocerebrosidase activity that results from biallelic mutations in the GBA1 gene. Its phenotypic variability allows GD to be classified into 3 subtypes based on the presence and extent of neurological manifestations. Enzyme replacement therapy (ERT) has been available for all patients with GD in Taiwan since 1998. Newborn screening (NBS) for GD has been available since 2015. This study attempted to unveil the clinical features of patients diagnosed with GD during different eras in Taiwan.

MATERIALS AND METHODS

Data from the health records of two tertiary hospitals responsible for two-thirds of the patients with GD in Taiwan were used. The study population included all patients identified as having GD between 1998, and April 2022, in these two hospitals for review. A total of 42 individuals were included, six of whom were diagnosed by NBS.

RESULTS

Our cohort presented a higher proportion of GD3 individuals, both by clinical suspicion and by NBS diagnosis, than that reported worldwide. The major subtypes that were recognized following NBS diagnosis were GD2 and GD3. The majority of GD patients carry at least one p.Leu483Pro variant. The 5-year survival rates were 0% for GD2 patients and 100% for patients with other subtypes. Patients diagnosed during the post-NBS era were free of symptoms on initial presentation, except for those with the GD2 subtype. For those diagnosed earlier, ERT was shown to be effective in terms of improved hemograms and prevented bone crises. However, the neurological symptoms in GD3 patients progressed despite ERT intervention.

CONCLUSION

ERT is essential in reversing the hematological presentations and preventing the skeletal complications of GD. Timely diagnosis of GD with NBS allows for early intervention with ERT to prevent disease progression and complications. However, the need for effective intervention for neurological dysfunction remains unmet.

P–522 Cervical secretion methylation profile is associated with the success of frozen-thawed embryo transfer - a proof-of-concept study

Study question

Is cervical secretion gene methylation profile different between receptive and non-receptive endometrium and associated with implantation outcome in frozen-embryo transfer (FET) cycle?

Summary answer

The combination of candidate genes methylation profiles obtained from cervical secretion showed significant associations with pregnancy outcomes.

What is known already

Implantation failure remains a black box in reproductive medicine, and the exact mechanism of how endometrial receptivity is regulated is still unknown. Epigenetic modifications play a role in the gene expression pattern and may alter the endometrial receptivity in the human endometrium. Cervical secretion containing various implantation-related cytokines, and the gene methylation change can be used as a non-invasive molecular source that reflects the endometrium condition.

Study design, size, duration

In this retrospective case-control study, sixty-two women who entered the FET cycle (30 pregnant and 32 non-pregnant women) were enrolled.

Participants/materials, setting, methods

Cervical secretion was collected before embryo transfer from women enrolled in multicenter university-affiliated reproductive units. The DNA methylation status of six candidate genes was measured using quantitative methylation-specific PCR (qMSP). The correlation between methylation change and the pregnancy outcome was analyzed.

Main results and the role of chance

The candidate genes were selected from that associated with implantation with literature review and the original genome-wide DNA methylation data from NCBI GEO DataSets (GSE90060) which processed using bioinformatics analysis. Six candidate genes whose CpG-level methylation analysis with β-value statistically higher in receptive endometrium than in a pre-receptive endometrium were selected. All six candidate genes showed different degrees of correlation with the pregnancy outcomes. Among them, PRKAG2 methylation changes showed the highest correlation with the pregnancy outcome. A logistic regression model was used to evaluate the performance of a single gene or a combination of genes for implantation prediction. The results showed a statistically significant association between the methylation status of a combination of genes (PRKAG2, KRS1, HAND2) and the pregnancy outcome (p = 0.008), resulting in an optimal AUC of 0.7 (95% CI: 0.57 - 0.81) for implantation prediction.

Limitations, reasons for caution

The results obtained from a relatively small cohort size. A larger study and further comprehensive methylome investigations are warranted.

Wider implications of the findings: This study is the first proof-of-concept study that cervical secretion methylation profile is associated with implantation outcome in a FET cycle, and showed potential as a non-invasive method for implantation prediction.

Trial registration number

non applicable

Imaging Validation of Drug-Eluting Beads Transarterial Chemoembolization of Hepatocellular Carcinomas in Living Donor Liver Transplantation

OBJECTIVE

The aim of this study is to determine whether post-transarterial chemoembolization imaging (computed tomography or magnetic resonance imaging) could accurately predict the tumors' necrosis on pathologic specimens.

BACKGROUND

Transarterial chemoembolization with drug-eluting beads has been proven to be an effective way to bridge patients with hepatocellular carcinomas to liver transplantation.

MATERIALS AND METHODS

From September 2012 to June 2017, 59 patients with a total of 78 hepatocellular carcinomas, who received transarterial chemoembolization with drug-eluting beads before liver transplantation in Kaohsiung Chang Gung Memorial Hospital, were included in the study. All patients and hepatocellular carcinomas have pre-transarterial chemoembolization and post-transarterial chemoembolization images (computed tomography or magnetic resonance imaging) and pathological findings for correlation. Tumor response was evaluated according to modified Response Evaluation Criteria in Solid Tumors. The ranges of necrotic percentage are 100%, 91-99%, 51-90%, and <50%.

RESULTS

The accuracy rate between the imaging and pathology correlation was 40% for computed tomography and 42% for magnetic resonance imaging. The recurrent rate of the complete respond group is 11.5%, the partial respond group is 16.0%, and the stationary group is 28.6%.

CONCLUSION

Computed tomography and magnetic resonance imaging sensitivity is not satisfactory for microscopic evaluation of residual tumors after transarterial chemoembolization with drug-eluting beads. However, survival is good after liver transplantation no matter what the microscopic findings were.

[Role and mechanism of hydrogen sulfide in cigarette smoke induced chronic obstructive pulmonary disease related pulmonary vascular remodeling in rats]

Objective: To investigate the role and mechanism of hydrogen sulfide (H2S) in rats with chronic obstructive pulmonary disease (COPD) related pulmonary vascular remodeling. Methods: Twenty four healthy male Sprague-Dawley rats were randomly divided into 4 groups: control group, cigarette smoke (CS) group, CS+ Sodium hydrosulfide (NaHS) group and CS+ DL-propargylglycine (PPG) group. Rats in control group were fed normally and breathed clear air, and for the rest groups, passive cigarette smoke inhalation method were adopted to establish COPD model. After 8 weeks, the rats in corresponding groups were treated by NaHS or PPG. After 16 weeks, the markers of pulmonary vascular remodeling in all groups were measured. Proliferation marker proliferative cell nuclear antigen (PCNA) and oxidative stress marker 3-neurotrophin (3-NT) in all groups were measured by immunohistochemistry (IHC). Results: Compared with control group, the airway resistance was increased (0.859±0.283 vs 0.578±0.088, P<0.05) and the pathological scores was much higher in CS group, which suggested that the COPD model was successful. The degree of small resistance pulmonary artery medial wall thickness and full vascular muscularization of CS group were much higher (0.54±0.20 vs 0.37±0.12, 0.39±0.08; 0.61±0.16 vs 0.20±0.12, 0.34±0.13, all P<0.01)than control group and CS+ NaHS group, there was no significant difference between CS+ PPG group and CS group. In accordance with the results of morphometric analysis, the proliferation marker PCNA was more in CS group when compared with control group and CS+ NaHS group (0.27±0.08 vs 0.12±0.06, 0.14±0.06, both P<0.05), there was no significant difference between CS+ PPG group and CS group. Furthermore, the IHC also showed that 3-NT significantly increased in CS group compared with control group and CS+ NaHS group (0.26±0.08 vs 0.18±0.04, 0.19±0.06, both P<0.01), there was no significant difference between CS+ PPG group and CS group as well. In addition, the small resistance pulmonary artery medial wall thickness had strong correlation with the expression level of oxidative stress marker 3-NT (r=0.906, P<0.001). Conclusion: H2S significantly attenuates cigarette smoke induced COPD related pulmonary vascular remodeling, which could be related to its ability to decrease oxidative stress.

Providing instrumental social support is more beneficial to reduce mortality risk among the elderly with low educational level in Taiwan: a 12-year follow-up national longitudinal study

BACKGROUND

To evaluate whether the effects of providing or receiving social support are more beneficial to reduce mortality risk among the elderly with different educational levels.

METHODS

In this long-term prospective cohort study, data were retrieved from the Taiwan Longitudinal Study on Aging. This study was initiated from 1996 until 2007. The complete data from 1492 males and 1177 females aged ≥67 years were retrieved. Participants received financial, instrumental, and emotional support, and they actively provided instrumental and emotional support to others and involved in social engagement. Education attainment was divided into two levels: high and low. The low education level included illiterate and elementary school. The high education level included junior high school to senior high school and above college. Cox regression analysis was used to examine the association between providing or receiving social support on mortality with different educational levels.

RESULTS

The average age of the participants in 1996 was 73.0 (IQR=8.0) years, and the median survival following years (1996-2007) of participants was 10.3 (IQR=6.7) years. Most participants were low educational level including illiterate (39.3%) and elementary school (41.2%). Participants with high educational level tend to be younger and more male significantly. On the contrary, participants with low educational level tend to have significant more poor income, more depression, more cognition impairment, more with IADL and ADL disability than high educational level. Most participants received instrumental support from others (95.5%) and also provided emotional support to others (97.7%). Providing instrumental support can reduce 17% of mortality risk among the elderly with a low level of education after adjusting several covariates [Hazard ratio (HR) = 0.83; 95% confidence interval (CI) = 0.70-0.99; p = 0.036].

CONCLUSIONS

Providing instrumental social support to others confer benefits to the giver and prolong life expectancy among the elderly with low educational levels.

Improved identification of multiple drugs of abuse and relative metabolites in urine samples using liquid chromatography/triple quadrupole mass spectrometry coupled with a library search

RATIONALE

Although two multiple reaction monitoring (MRM) transitions per compound are used for identification performed using liquid chromatography/triple quadrupole mass spectrometry (LC/QqQ-MS/MS), differences in identification criteria among several regulations may lead to misidentification. We demonstrated that the use of two MRM transitions and product ion spectra improves compound identification.

METHODS

The scan cycle time was reduced using time-scheduled MRM (tMRM), data-dependent product ion scanning, and dynamic exclusion. The quantification and identification performance for 13 drugs of abuse and their metabolites were evaluated.

RESULTS

Deuterated internal standards compensated for ion suppression. All analytes exhibited intra- and interday precision <12.11%, accuracy of -10.31% to +10.10%, and no carryover. The LC/QqQ-MS/MS and reference gas chromatography/MS methods were equally precise, accurate, and specific. Several regulatory organizations include two MRM transitions, their ratio, and retention time as identification criteria. In 28 samples, the relative ion ratio variation was >10% and product ion spectral matches with >94% probabilities improved drug and metabolite identification.

CONCLUSIONS

The LC/QqQ-MS/MS method is a comprehensive assay in which tMRM and the product ion scan are combined in a single run by using a QqQ mass analyzer to simultaneously quantify amphetamine, ketamine, morphine, and their relative metabolites in urine. The proposed method can be applied in forensic science.

Outcomes after surgery in patients with previous stroke

BACKGROUND

Limited information is available on the association between a medical history of stroke and postoperative outcomes. This study investigated the outcomes following non-neurological surgery in patients with previous stroke.

METHODS

Using Taiwan's National Health Insurance Research Database, a nationwide cohort study was conducted of patients who underwent non-neurological surgery between 2008 and 2010 with a medical history of stroke in the 24-month period before operation. Patients who had non-neurological surgeries without previous stroke were selected as controls by the propensity score-matched pair method. Thirty-day postoperative complications and in-hospital mortality were compared between the two groups.

RESULTS

Some 1 426 795 adults underwent major inpatient non-neurological surgery, of whom 45 420 had a medical history of previous stroke. Patients with previous stroke who underwent surgery had an increased risk of postoperative pneumonia, septicaemia, acute renal failure, acute myocardial infarction, pulmonary embolism and 30-day in-hospital mortality (adjusted rate ratio (RR) 1·79, 95 per cent c.i. 1·61 to 1·99). Compared with controls, patients with previous stroke due to intracerebral haemorrhage (RR 3·41, 2·97 to 3·91), and those who were treated in intensive care (RR 2·55, 2·24 to 2·90) or underwent neurosurgery (RR 2·49, 2·12 to 2·92), had an increased 30-day in-hospital mortality rate. Postoperative mortality also increased with stroke-related co-morbidities, and with stroke 1-6 months before surgery (RR 3·31, 2·91 to 3·75).

CONCLUSION

Patients with previous stroke had a higher risk of adverse postoperative outcomes; their 30-day in-hospital mortality rate was nearly twice that of patients without previous stroke.

Density-driven spontaneous streak segregation patterns in a thin rotating drum

Granular mixtures may segregate because of external driving forces, which play an important role in industry and geophysics. We investigate experimentally the mechanism of density-driven spontaneous streak segregation patterns in a thin rotating drum. We find that a spontaneous streak segregation pattern can occur in such a system, which we call a D-system. A phase diagram identifies three segregation pattern regimes in this study: the mixing regime, the core segregation regime, and the streak segregation regime.

The acoustic radiation force impulse elastography evaluation of liver fibrosis in posttransplantation dysfunction of living donor liver transplantation

BACKGROUND

The acoustic radiation force impulse elastography (ARFI) is a new technology of elastography integrated into B-mode ultrasonography. It has been a reliable method to evaluate liver fibrosis of chronic liver disease in recent years, but less applied in the posttransplantation liver. The aim of the study was to evaluate liver fibrosis by the ARFI with correlation of pathological stages in living donor liver transplantation (LDLT).

MATERIALS AND METHODS

From August 2010 to August 2012, there were 57 LDLT patients with liver biopsy (LB) due to posttransplantation dysfunction; all patients also received posttransplantation ARFI liver stiffness measurement (LSM) after transplantation for liver fibrosis staging. The ARFI elastography was performed using a Siemens Acuson S2000 ultrasound system with 4V1 transducers (Acusion, Siemens Medical Systems Co. Ltd. Erlangen, Germany). The ARFI LSM value was presented by shear wave velocity (SWV, m/s). The fibrosis staging as F0 to F4 was in accordance with the Metavir scoring system.

RESULTS

A total of 57 patients had both posttransplantation LB and effective ARFI fibrosis staging for correlation. The ARFI LSM value increased with severity of liver fibrosis and had significant linear correlation with the results of histological fibrosis staging. The ARFI LSM sensitivities (Se), specificities (Sp), and cutoff values based on receiver-operator characteristic curve were F0: 0.75 m/s (Se: 93.8%, Sp: 4%), F1: 1.06 m/s (Se: 95.5%, Sp: 25.7%), F2: 1.81 m/s (Se: 50%, Sp: 83.6%) and F3: 2.33 m/s (Se: 100%, Sp: 92.9%). Predictive value of ARFI LSM reported a significant difference between early fibrosis stage (F0-F1) and advanced fibrosis stage (F ≧ 2) (P < .05).

CONCLUSION

In this study, ARFI demonstrated a strong linear correlation and severity of liver fibrosis with LB pathologic staging. ARFI can be an alternative and compensatory method for frequent LB in the posttransplantation liver.

Postoperative adverse outcomes after non-hepatic surgery in patients with liver cirrhosis

BACKGROUND

Postoperative adverse outcomes in patients with liver cirrhosis are not completely understood. This study evaluated the association between liver cirrhosis and adverse outcomes after non-hepatic surgery.

METHODS

Reimbursement claims were used to identify patients with preoperative liver cirrhosis who underwent non-hepatic surgery from 2004 to 2007. Control patients without cirrhosis were matched by age, sex, type of surgery and anaesthesia. The adjusted odds ratios (ORs) and 95 per cent confidence intervals (c.i.) of postoperative adverse events associated with liver cirrhosis were analysed by multivariable logistic regression.

RESULTS

Thirty-day mortality rates among 24 282 patients with cirrhosis and 97 128 control patients were 1·2 per cent (299 deaths) and 0·7 per cent (635 deaths) respectively. Liver cirrhosis was associated with postoperative 30-day mortality (OR 1·88, 95 per cent c.i. 1·63 to 2·16), acute renal failure (OR 1·52, 1·34 to 1·74), septicaemia (OR 1·42, 1·33 to 1·51) and intensive care unit admission (OR 1·39, 1·33 to 1·45). Postoperative mortality increased in patients who had liver cirrhosis with viral hepatitis (OR 2·87, 1·55 to 5·30), alcohol dependence syndrome (OR 3·74, 2·64 to 5·31), jaundice (OR 5·47, 3·77 to 7·93), ascites (OR 5·85, 4·62 to 7·41), gastrointestinal haemorrhage (OR 3·01, 2·33 to 3·90) and hepatic coma (OR 5·11, 3·79 to 6·87).

CONCLUSION

Patients with liver cirrhosis had increased mortality and complications after non-hepatic surgery, particularly those with cirrhosis-related clinical indicators.

Adverse postoperative outcomes in surgical patients with immune thrombocytopenia

Background

Patients with immune thrombocytopenia (ITP) are likely to have various medical co-morbidities, yet their global features regarding adverse postoperative outcomes and use of medical resources when undergoing major surgery are unknown. The objective of this study was to validate whether ITP is an independent risk factor for adverse postoperative outcomes, and to explore the potential clinical predictors of outcomes after major surgery among patients with ITP.

Methods

A retrospective population-based cohort study was conducted using Taiwan's National Health Insurance Research Database, controlling for preoperative co-morbidities by means of multiple logistic regression. Major postoperative complication and mortality rates, and in-hospital medical costs were analysed.

Results

The study included 11 085 surgical patients with ITP and 44 340 controls without ITP matched for sex, age, and type of surgery and anaesthesia. Surgical patients with ITP had a higher risk of postoperative death (odds ratio (OR) 1·89, 95 per cent confidence interval 1·57 to 2·27), and overall postoperative complications (OR 1·47, 1·39 to 1·56), and increased hospital stay (OR 1·90, 1·80 to 2·01), admission to the intensive care unit (OR 1·73, 1·63 to 1·83) and medical costs (OR 1·89, 1·79 to 1·99). Amount of preoperative platelet and/or red blood cell transfusion, emergency visits and admission to hospital for ITP care were identified as risk factors for adverse postoperative outcomes.

Conclusion

Patients with ITP undergoing surgery are at increased risk of adverse perioperative events, particularly if blood or blood product transfusion are required preoperatively, or the procedure is done as an emergency.

Using mass spectrometry to detect buffalo salivary odorant-binding protein and its post-translational modifications

A large number of mammalian odorant-binding proteins, which are lipocalins, have been studied. These proteins participate in peri-receptor events by selecting and carrying odorant molecules. The present study aimed at identifying the buffalo salivary odorant-binding protein (sOBP), and to determine its post-translational modification using mass spectrometry. The buffalo salivary 21  kDa protein was initially separated adopting sodium dodecyl sulfate-polyacrylamide gel electrophoresis and it was identified as sOBP with high statistical reliability using liquid chromatography/tandem mass spectrometry (LC/MS/MS) and SEQUEST, for the first time. Further, the post-translationally modified peptides were screened adopting MS/MS. A total of four post-translational modifications, namely glycation at lysine-(59), hydroxylation at lysine-(134), ubiquitination at lysine-(121), and dihydroxylation in lysine-(108), were recorded. Moreover, these modifications have not been identified in buffalo salivary odorant-binding protein.

Granular dynamics of a slurry in a rotating drum

We study the effects of interstitial fluid viscosity on the rates of dynamical processes in a thin rotating drum half-filled with monodisperse glass beads. The rotating speed is fixed at the rolling regime such that a continuously flowing layer of beads persists at the free surface. While the characteristic speed of a bead in the flowing layer decreases with the fluid viscosity μ, the mixing rate of the beads is found to increase with μ. These findings are consistent to a simple model related to the thickness of the flowing layer. In addition, our results indicate a possible transition from the inertial limit regime to the viscous limit regime (reported previously by S. Courrech du Pont [Phys. Rev. Lett. 90, 044301 (2003)]) when the Stokes number is reduced.

Dose reconstruction for residents living in buildings with moderate and minor 60Co contamination in rebar

Previously, we have reconstructed cohort dependent individual doses for residents living in rebar buildings of high 60Co contamination. These reconstructions were carried out using intensively collected TLD data on exposure rates at locations of 1 m height and 1 m x 1 m intersections. The present work deals with dose reconstructions for residents living in rebar buildings of moderate and minor 60Co contamination. Since only limited data on exposure rates from survey meters were available, dose reconstructions were based on these data using interpolations. To utilize such data, we examined them with respect to all factors that influenced the dose uncertainties. The interpolated results were given in terms of contour plots (isodose curves) and compared with corresponding results derived from TLD data and Monte Carlo simulations. The comparison revealed that survey meter data could be used to provide reasonable and conservative estimates of residential doses. By applying the cohort-dependent room occupancy factor and the site-dependent area occupancy factor, we reconstructed cohort dependent individual doses and associated uncertainties. Results of dose reconstructions for all residents living in contaminated rebar buildings were provided to the Atomic Energy Council and health authorities for epidemiologic and medical uses.

Laser-induced reorientation effect and ripple structure in dye-doped liquid-crystal films

The effects of light-induced reorientation on a homeotropical dye-doped liquid crystal (DDLC) cell are discussed. The photoexcited azo dye Methyl Red (MR) is diffused and adsorbed onto the substrate, thus forming a ripple structure. The adsorbed dye and the laser-induced ripple structure then reorient the liquid-crystal molecules and induce a holographic grating. Initially, the liquid-crystal directors are reoriented primarily by the adsorbed dye. However, given a sufficiently large ripple groove amplitude, the torque imposed by the ripple grooves overcomes that which is due to the adsorbed dyes, and the liquid crystals are realigned along the groove direction.

Dynamic studies of holographic gratings in dye-doped liquid-crystal films

The dynamic behavior of a holographic grating induced in a homeotropically aligned dye-doped liquid-crystal film is investigated. In the presence of an applied dc voltage, photoexcited azo dyes induce a photorefractive grating and then diffuse and are adsorbed onto cell substrates. The reorientation of liquid crystals as a result of adsorbed dyes leads to a phase grating that is phase shifted 90 degrees from the photorefractive grating. Competition of these two gratings induces two-beam coupling of the writing beams, initially transferring energy from beam 1 to beam 2 and then, after a pause, from beam 2 to beam 1.

The hetero Diels-Alder reactions of masked o-benzoquinones with nitroso compounds

The first examples of hetero Diels-Alder reaction of masked o-benzoquinones with nitroso dienophiles leading to novel and highly functionalized heterocycles, which are potential intermediates for nitrogenous natural products are reported.

Study on the secondary structure of protein in amide I band from human colon cancer tissue by Fourier-transform infrared spectroscopy

BACKGROUND

Fourier-transform infrared spectroscopy (FT-IR) is a powerful tool for study of the secondary conformation of intact protein in biological tissues and for diagnosis of disease states. The purpose of this study is to utilize FT-IR as a diagnostic tool to estimate the secondary structure of amide I in normal and cancer tissue of human colon.

METHODS

Pairs of tissue samples from colon cancer and histologically normal mucosa tissue 5-10 cm from the tumor were obtained from a patient who underwent partial colectomy. In the present study we investigated the changes in the secondary structure of amide I of normal and malignant human colon tissue using FT-IR microspectroscopy with attenuated total reflectance. Secondary-derivative analysis relative to the original and curve-fitting analysis infrared spectra were also carried out.

RESULTS

The conformational changes of the secondary structure of protein in normal and cancerous human colon tissue were (1) the composition of alpha-helixes increased in human cancerous colon tissue (15.30%) compared to normal colon tissue (11.72%); (2) beta-sheets which were 46.8% in healthy tissue decreased to 30.71% in cancer tissue; (3) beta-turns increased from 26.28% in normal tissue to 38.48% in cancer tissue; and (4) the composition of random coils was not significantly different between normal tissue (15.12%) and cancer tissue (15.51%).

CONCLUSION

Our data demonstrate that protein in colon cancer displays abnormal FT-IR spectra. The conformational changes of the secondary structure of this protein in terms of alpha-helixes, beta-sheets and beta-turns were observed in normal and cancerous tissue from the same individual were compared.

Processing of DNase domain during translocation of colicin E7 across the membrane of Escherichia coli

Translocation of colicin across the membrane of sensitive cells has been studied extensively. However, processing of the toxicity domain of colicin during translocation has been the subject of much controversy. To investigate the final translocation product of colicin across the membrane of Escherichia coli, an endogenously expressed His-tagged Im7 protein was constructed to detect any translocation product containing the DNase domain traversed the inner membrane into cytoplasm of the E. coli cells. As a result, a final processed DNase domain of ColE7 was identified in the intracellular space of the cells treated with Col-Im complex. In the presence of periplasmic extracts, in vitro processing of DNase domain of ColE7 was also observed. These results suggest that the processing of ColE7 has occurred for translocation of the DNase-type colicin across the membrane and the process is probably taking place in the periplasmic space of the membrane.

Low tibial osteotomy for moderate ankle arthritis

Low tibial osteotomy is one of the significant advances of ankle reconstruction techniques that has been made recently in an effort to halt arthritis in its early stages and leave fusion as the last, not the only, alternative treatment of ankle arthritis. From 1989 to 1995, we performed 18 low tibial osteotomies which included 6 cases of post-traumatic arthritis and 12 cases of degenerative arthritis. The ages of the 7 male and 11 female patients ranged from 18 to 78 years with an average of 41.9 years. The follow-up period lasted a mean of 47.7 months, ranging from 25 to 82 months. The average functional score changed from 49.6 pre-operatively to 88.5 at the last follow up, and showed yearly improvement. Complications included one case of late infection and two cases of implant failure, none of which led to nonunion. The indication for low tibial osteotomy is the intermediate stage of moderate ankle arthritis with a medial joint lesion and intact lateral facet. Using pressure redistribution on the joint surface, this procedure is an alternative treatment for ankle arthritis which may save an arthritic ankle from the fate of fusion or at least postpone fusion surgery.

Fast optical recording in dye-doped polymer-dispersed liquid-crystal films

We describe a fast optical recording material based on a dye-doped polymer-dispersed liquid-crystal film. A holographic grating is written in this film with a single Q -switched Nd:YAG laser pulse that has a duration of ~6 ns . Such a grating is due to the reorientation effect of the liquid-crystal molecules through interaction with the photoinduced adsorption of the doped azo dyes. Experimental results indicate that the grating thus formed is permanent but electrically switchable.

The first total synthesis of (+/-)-eremopetasidione

[figure: see text] The total synthesis of racemic eremopetasidione, a norsesquiterpenoid, has been achieved in nine steps and 30% overall yield starting from creosol (5). Diels-Alder reaction of masked o-benzoquinone 6 and ethyl vinyl ketone and Cope rearrangement of 2-silyloxy-1,5-dienone 3 are the key steps.

Highly functionalized Bicyclo[2.2.2]octenone-fused [60]fullerenes from masked o-benzoquinones and C(60)

[reaction: see text] The Diels-Alder reactions of masked o-benzoquinones (MOBs) with [60]fullerene, affording novel and highly functionalized bicyclo[2.2. 2]octenone-fused [60]fullerene derivatives, are described.

Landmarks in burn prevention

The objective of this paper is to highlight landmarks in burn prevention. Novel strategies in the areas of law and regulation, environmental and consumer product design, and educational programs are identified and discussed. Notwithstanding marked reductions in burn morbidity and mortality, especially in economically developed countries, burn injuries remain an important public health concern throughout the world. More, and more effective, burn prevention programs coupled with renewed efforts to reduce the social and environmental correlates of burn injuries (poverty, overcrowding, family stress, and educational deficits) are needed to further reduce burn incidence and its long-term sequelae.

One-pot stereoselective synthesis of tricyclic bislactones from 2-pyrones and 2-methoxyfuran

[reaction: see text] A one-pot synthesis of the title compounds via highly chemo-, regio-, and stereoselective Diels-Alder reactions of 2-pyrones with 2-methoxyfuran is described.

Landmarks in burn prevention

The objective of this paper is to highlight landmarks in burn prevention. Novel strategies in the areas of law and regulation, environmental and consumer product design, and educational programs are identified and discussed. Notwithstanding marked reductions in burn morbidity and mortality, especially in economically developed countries, burn injuries remain an important public health concern throughout the world. More, and more effective, burn prevention programs coupled with renewed efforts to reduce the social and environmental correlates of burn injuries (poverty, overcrowding, family stress, and educational deficits) are needed to further reduce burn incidence and its long-term sequelae.

Study of stabilizing CaF2:Dy ultraviolet sensitivity by double annealing treatment

The intrinsic thermoluminescent response to ultraviolet radiation of CaF2:Dy phosphor is enhanced by pre-irradiation high-temperature annealing treatment. The thermoluminescent response is stabilized by adding a medium temperature annealing treatment after the previous annealing. The experimental results show that the annealing treatment of 1 h 850 degrees C high-temperature annealing followed by 1 h 350 degrees C medium-temperature annealing is the optimum treatment to have high thermoluminescent response and good stability. The results also show that (1) the thermoluminescent response to 253.7 nm ultraviolet radiation is increased and stabilized, (2) the thermoluminescent sensitivity and glow curve distribution to 235.7 nm ultraviolet radiation are retained, and (3) the thermoluminescent response to 253.7 nm ultraviolet is linear from 3 to 1 x 10(3) Jm(-2), but there is no linear response with respect to 365 nm ultraviolet.

Symptomatic ossification of the posterior longitudinal ligament of the lumbar spine. Case report

The authors report a case of focal ossification of the posterior longitudinal ligament (OPLL) behind the L-3 vertebral body. This is relatively rare among previously reported cases in the literature. Magnetic resonance (MR) imaging revealed that the ossifying portion of the PLL was impinging on the left L-3 nerve root. Contrast enhancing hypertrophic PLL was also demonstrated around the ossification and along the lumbosacral PLL. Via a laminectomy and wide excision of the PLL the lesion was removed. Pathological examination revealed a nodule composed of fibrous cartilage, lamina bone, and mature fat marrow. Enchondral ossification could be identified under a microscope. The authors believe that preoperative MR imaging evaluation is important for the detection of the relationship between an OPLL and the neural structure. Excision of the symptomatic OPLL should be performed when needed to obtain adequate nerve root decompression.

The crystal structure of the DNase domain of colicin E7 in complex with its inhibitor Im7 protein

BACKGROUND

Colicin E7 (ColE7) is one of the bacterial toxins classified as a DNase-type E-group colicin. The cytotoxic activity of a colicin in a colicin-producing cell can be counteracted by binding of the colicin to a highly specific immunity protein. This biological event is a good model system for the investigation of protein recognition.

RESULTS

The crystal structure of a one-to-one complex between the DNase domain of colicin E7 and its cognate immunity protein Im7 has been determined at 2.3 A resolution. Im7 in the complex is a varied four-helix bundle that is identical to the structure previously determined for uncomplexed Im7. The structure of the DNase domain of ColE7 displays a novel alpha/beta fold and contains a Zn2+ ion bound to three histidine residues and one water molecule in a distorted tetrahedron geometry. Im7 has a V-shaped structure, extending two arms to clamp the DNase domain of ColE7. One arm (alpha1(*)-loop12-alpha2(*); where * represents helices in Im7) is located in the region that displays the greatest sequence variation among members of the immunity proteins in the same subfamily. This arm mainly uses acidic sidechains to interact with the basic sidechains in the DNase domain of ColE7. The other arm (loop 23-alpha3(*)-loop 34) is more conserved and it interacts not only with the sidechain but also with the mainchain atoms of the DNase domain of ColE7.

CONCLUSIONS

The protein interfaces between the DNase domain of ColE7 and Im7 are charge-complementary and charge interactions contribute significantly to the tight and specific binding between the two proteins. The more variable arm in Im7 dominates the binding specificity of the immunity protein to its cognate colicin. Biological and structural data suggest that the DNase active site for ColE7 is probably near the metal-binding site.

Preliminary study of dose equivalent evaluation for residents in radioactivity contaminated rebar buildings

It has recently been found that several resident and office buildings in Taiwan were constructed with 60Co-contaminated reinforcing steel bar (rebar). Both governmental officials and the residents of such buildings have been concerned about this finding. In order to respond to the situation, the government has adopted a number of remedial measures, including full-scale radiation survey, dose evaluation and physical examinations of residents. This article presents three methods for evaluating the dose equivalents of the residents living in the contaminated rebar buildings by means of gamma-ray survey, necklace-type thermoluminescence dosimeters (TLDs) and the human lymphocyte chromosome aberration analyses. The results reveal that the dose evaluation by gamma-ray survey is rather conservative. Generally for the residents whose annual dose equivalents are greater than 5 mSv (0.5 rem) by gamma-ray survey, the dose equivalents from necklace-type TLDs are only within the range of 20 to 50% of the evaluated values mentioned above. For chromosome analyses, at least 500 lymphocyte cells were scored and analyzed for each resident. Most of the chromosome analysis data show that the dose equivalents received by residents are lower than the detection limit of the method (100 mSv) and quite different from the estimated dose obtained from either gamma-ray survey or necklace-type TLD measurements.

Change of thermal stability of colicin E7 triggered by acidic pH suggests the existence of unfolded intermediate during the membrane-translocation phase

Purified colicin E7 was analyzed by CD spectrum and gel filtration chromatography in a mimicking membrane-translocation phase. It was found that the CD spectra of colicin E7 at pH 7 and pH 2.5 were similar. Although the melting temperature of the protein shifted from 54.5 degrees C to 34 degrees C at low pH, the thermal denaturation curves of colicin E7 at different pH conditions still fit a two-state model. These experimental results imply that a minor structural change, triggered by acidic pH, for instance, may reduce the energy required for protein melting. In contrast to the minor change in secondary structure at different pH conditions, we observed that, in vitro, all monomeric colicin E7s converted into multimer-like conformations after recovering from the partial unfolding process. This multimeric form of colicin can only be dissociated by formamide and guanidine hydrochloride, indicating that this protein complex is indeed formed by aggregation of the monomeric colicins. Most interestingly, the aggregated colicins still perform in vivo bacteriocidal activity. We suggest that in a partial unfolding state the colicin is prepared for binding to the specific targets for translocation through the membrane. However, in the absence of specific targets in vitro these unfold intermediates may therefore aggregate into the multimeric form of colicins.

Dose reconstruction for residents living in 60Co-contaminated rebar buildings

The first 60Co-contaminated rebar building was discovered in Taipei city in 1992. As of 18 July 1997, 144 buildings with 1,327 housing units were confirmed to contain 60Co-contaminated rebars. All these reinforced concrete buildings were constructed between 1982 and 1984. Thousands of residents have been exposed to ionizing radiation of various degrees. Preliminary assessments by the Atomic Energy Council showed that the accumulated maximal doses ranged from a few mSv to several Sv. The purpose of this work was to reconstruct more reliable individual doses for epidemiologic and medical uses. This reconstruction provided the best estimated doses as well as conceivable upper and lower bounds. The variation of residential day-life activities by individual members in a family was considered according to their sex, age, profession, etc. Intensive data on exposure rates were collected using thermoluminescent dosimeters positioned at 1 m height and 1 m x 1 m intersections with additional measurements at special locations such as bed, sofa, dining table, etc. Thermoluminescent dosimeter measurements were performed in all 24 residences studied in this work. This showed that the Atomic Energy Council maximal doses were 2-6 times higher than the present best estimated doses. Among all family members, elders and housewives received the highest doses; children received the lowest doses. The difference in doses among all family members belonging to different cohort categories is within a factor of two.

Experimental study of steady and pulsatile flows in cerebral aneurysm model of various sizes at branching site

Pulsatile and steady flow fields in cerebrovascular aneurysm models of various sizes are presented in terms of laser-Doppler velocimetry measurements and flow visualization. The bifurcation angle was 140 deg and volume flow rate ratio between the branches was 3:1. The mean, peak, and minimal Reynolds numbers based on the bulk average velocity and diameter of the parent vessel were 600, 800, and 280, respectively. It is found that among the tested sizes there exists a middle range of aneurysm sizes, above and below which the forced-vortex inside the aneurysmal model is weaker and lacking, respectively, whereas in the middle range of the tested sizes the forced vortex is stronger and the fluctuation level is higher near the dome. The present results also identify the major fluid dynamic factors of the aneurysmal promotion or rupture for the medium and larger aneurysms, respectively. Furthermore, the maximum fluctuation intensity is found to increase with aneurysm size. The locations of the maximum fluctuation intensity are found to occur in the bifurcation area or at the neck instead of intra-aneurysm.

Site-directed mutagenesis of the aspartokinase gene lysC and its characterization in Brevibacterium flavum

Using overlap extension polymerase chain reaction (PCR), five transformants of Escherichia coli containing site-directed mutagenized lysC beta gene were generated and analysed. Exchange of C to A and C to T at nucleotide 1118 of the mutated lysC beta gene causes a substitution of serine301 in the wild-type enzyme for tyrosine301 and phenylalanine301 in the mutant enzymes, respectively. Enzyme assays showed that Brevibacterium flavum cells harbouring pSUMN18 with mutated lysC beta genes exhibited 16-20 fold lower specific activities of aspartokinase as compared to that of host containing wild-type lysC gene. The mutation introduced into lysC beta of B. flavum CCRC 18271 resulted in partial feedback-resistant aspartokinase activity.

[Methicillin-resistant Staphylococcus aureus: an alarming problem in Chang Gung Memorial Hospital]

Strains of methicillin-resistant Staphylococcus aureus (MRSA) have become increasingly common in the United States and in many other countries since 1975. The prevalence of MRSA colonization and infection has increased in acute-care and chronic-care facilities, outpatient clinics, and in the community. We reviewed the sensitivity test of antibiotics in Chang Gung Memorial Hospital system, and revealed a steady decrease in sensitivity to Cephalothin, Oxacillin and Clindamycin during the past 10 years. It is still sensitive to Vancomycin. However, the amount of Vancomycin prescribed in the hospital system has increased three-folds during the recent 4 years. The purpose of this article is to review the MRSA in this hospital and to describe measures used to control MRSA transmission.

The cloning and nucleotide sequence of a Corynebacterium glutamicum 3-deoxy-D-arabinoheptulosonate-7-phosphate synthase gene

The aro gene of Corynebacterium glutamicum CCRC 18310 encoding 3-deoxy-D-arabinoheptulosonate-7-phosphate (DAHP) synthase was isolated by complementation of a DAHP synthase-deficient mutant of Escherichia coli AB3257. The specific activity of DAHP synthase was increased four-fold in a C. glutamicum strain harboring the cloned aro gene. The complete nucleotide sequence of the aro gene and its 5' and 3' flanking regions has been determined. The sequence contained an open reading frame of 368 codons, from which a protein with a molecular mass of 39,340 Da could be predicted. The deduced amino acid sequence shows high identity with the aro gene products of E. coli and Salmonella typhimurium.

Gallbladder mucosal blood flow increases during early cholesterol gallstone formation

Gallbladder absorption increases during early cholesterol gallstone formation and is influenced by the intraluminal presence of lithogenic bile. The effect of lithogenic bile on gallbladder mucosal blood flow is unknown. The current study tested the hypothesis that the presence of lithogenic gallbladder and hepatic bile enhances gallbladder mucosal blood flow in cholesterol-fed (0.4%) prairie dogs, as determined by hydrogen gas clearance. Gallbladder mucosal blood flow in control animals was 35.57 +/- 3.9 mL.min-1.100 g-1. In contrast, basal gallbladder mucosal blood flow in cholesterol-fed animals was significantly (P less than 0.01) increased to 64.94 +/- 8.7 mL.min-1.100 g-1. In crossover studies, the addition of lithogenic gallbladder bile to control animals (n = 6) resulted in a significant (P less than 0.025) 26% increase in gallbladder mucosal blood flow, whereas the addition of nonlithogenic gallbladder bile into gallbladders of cholesterol-fed prairie dogs resulted in a significant (P less than 0.025) 58% decrease in gallbladder mucosal blood flow. Similarly, hepatic bile crossover studies showed that the addition of lithogenic hepatic bile to control gallbladders significantly increased (P less than 0.025) gallbladder blood flow by 30%, whereas instillation of nonlithogenic hepatic bile in gallbladders of cholesterol-fed animals significantly (P less than 0.025) decreased gallbladder mucosal blood flow by 29%. These results suggest that alterations in gallbladder mucosal blood flow, influenced by the presence and absence of lithogenic bile, may play a role in cholesterol gallstone formation.

Macromolecule synthesis in temperature-sensitive mutants of methanol-utilizing Hansenula polymorpha

Temperature sensitive (ts) mutants of methanol-utilizing Hansenula polymorpha NTU-AM-P5 were isolated by UV irradiation, EMS and/or NTG treatment. They grow normally at permissive temperature (PT) 38 degrees C, but can not grow at restrictive temperature (RT) 46 degrees C. From chemical composition analysis, it was found that ts mutants NTU-AM-L2 and NTU-AM-L3 had higher RNA content than the others; while ts mutant NTU-AM-E19 had the highest protein content among the isolated strains. Leucinyl-tRNA synthetases activity was the highest among the twenty aminoacyl-tRNA synthetases in both wild type and their ts mutants. When the cells were shifted from PT to RT for 12 h, total aminoacyl-tRNA synthetase activity decreased in all tested strains. Leucinyl-tRNA synthetase of ts mutant NTU-AM-E10 decreased 91.23%. At RT, it was found that ts mutants NTU-AM-E10 and NTU-AM-E20 were defective in DNA synthesis; ts mutants NTU-AM-E15, NTU-AM-E20, NTU-AM-N37 and NTU-AM-m5 were defective in RNA synthesis; ts mutants NTU-AM-E10, NTU-AM-E20 and NTU-AM-m5 were somewhat defective in protein synthesis; while ts mutants NTU-AM-L2 and NTU-AM-L3 did not belong to any one of the above classifications.

Purification and characterization of a benzodiazepine-like substance from mammalian brain

An endogenous brain ligand which competes with [3H]-flunitrazepam for the binding to benzodiazepine receptor has been isolated and purified to homogeneity. The purification procedures involve the extraction of the endogenous ligand by homogenizing the brain tissue in water containing various protease inhibitors followed by filtration through a PM 10 membrane (exclusion limit: 10,000-dalton), column chromatographies on Sephadex G-50, Bio-Rad P2 and a series of C18 reverse phase HPLC columns. The purified endogenous ligand was eluted as a single and symmetrical peak monitored at either 220 or 280 nm. Furthermore, the ligand activity coincided with the absorption peak. The purified endogenous ligand is thermostable, insensitive to various peptidases and proteolytic enzymes, resistant to DNAse, RNAse, and carbohydrate enzyme e.g. neuraminidase (EC 3.2.1.18) and acid treatment. It has a major absorption peak at 220 nm and a minor one at 313 nm. The endogenous ligand appears to be quite specific since it only inhibits the binding of ligand to the central type benzodiazepine receptor but not to other receptors, e.g. peripheral type benzodiazepine receptor, alpha 1-adrenoceptor, alpha 2-adrenoceptor, beta-adrenoceptor and muscarinic cholinergic receptor. Furthermore, the inhibition of the receptor binding by the endogenous ligand is enhanced by GABA suggesting that the endogenous ligand is a benzodiazepine receptor agonist. The structure of the endogenous ligand is unknown.

Isolation and characterization of temperature-sensitive mutants of Hansenula

For investigation of the feasibility of obtaining yeast strains with high protein and low nucleic acid content or high nucleic acid and low protein content for industrial production of single cell protein or nucleotide, the methanol-utilizing Hansenula polymorpha NTU-AM-P5 was chosen for isolation of temperature-sensitive mutants. Approximately 70 temperature-sensitive (ts) mutants were obtained. All of the ts mutants increased in cell size and aggregated when they were cultivated at permissive temperature and shifted to restrictive temperature in the late log phase or in the stationary phase. 86.1% of ts mutants had a lower growth rate than that of their wild-type. Only ts mutants, NTU-AM-L2, NTU-AM-E10, NTU-AM-E19, NTU-AM-E25 and NTU-AM-E30 had same or slightly higher than that of their wild-type strain. Cycloheximide at 1 mg/ml inhibited the growth of ts mutant NTU-AM-E19, but inhibited one-third of the other ts mutants, and their wild-type strain. Rifampicin at 0.1 mg/ml had an inhibitory activity on wild-type strain but not on ts mutant NTU-AM-E1. ts mutants NTU-AM-L2 and NTU-AM-E19 converted methanol to cell mass more efficiently than others. The ts mutants divided into two groups. One included absolute ts mutants, such as NTU-AM-E15 and NTU-AM-E20, which did not grow even in enriched media at restrictive temperature; the other group, such as NTU-AM-L2, NTU-AM-L3, NTU-AM-E10, NTU-AM-E19, NTU-AM-N37 and NTU-AM-m5, was auxotrophic ts mutants, which grew slightly in enriched media at restrictive temperature.

Dissolution rates of corticoid solutions dispersed on silicas

Two nonporous and three porous amorphous silicas were used as dispersion media to convert corticoid solutions into free-flowing powders. The corticoids (prednisone, prednisolone, and hydrocortisone) were dissolved in N,N-dimethylacetamide-polyethylene glycol 400 (7:3 v/v) and their 10% (w/v) solutions were mixed with the silicas (1:3 v/w). Dissolution rates of the corticoids from such powdered solutions were more rapid than their micronized powders in various aqueous media.