Risk of Postcolonoscopy Thromboembolic Events: A Real-World Cohort Study

BACKGROUND& AIMS

Although antithrombotic agents could increase the risk of postpolypectomy bleeding, interruption of these agents also increases the risk of thromboembolism (TE). We assessed the risks of postcolonoscopy TE events and their association with the interruption of antithrombotic agents.

METHODS

This was a retrospective cohort study including consecutive patients undergoing colonoscopy between January 2016 and March 2021. We determined the rates of postcolonoscopy TE events in patients taking various antithrombotic agents (with or without interruption), and in different patient groups according to indications for colonoscopy, underlying TE, and bleeding risks.

RESULTS

Of the 6220 patients, 1755 (28.2%) were on antithrombotics. Overall, 20 patients (0.32%) developed TE events, and 25 (0.80%) of 3134 patients with polypectomy experienced major episodes of bleeding. Among all patients on antithrombotic agents, the highest rates of TE events were observed in patients on dual-antiplatelet therapy (4.65%; adjusted odds ratio [aOR], 28.0; 95% CI, 3.77-142.1) and clopidogrel (2.78%; aOR, 12.2; 95% CI, 2.10-57.0), compared with 0.11% among those not on antithrombotics. In patients interrupting anti-thrombotic agents, the risk of TE was increased compared to those on no agent as follows: stopping 2 or more antithrombotic agents (4.55%; aOR, 22.5; 95% CI, 1.09-158.0), monotherapy with clopidogrel (3.06%; aOR, 15.5; 95% CI, 2.86-69.6), warfarin (1.33%; aOR, 6.96; 95% CI, 1.14-33.5), or direct-acting oral anticoagulants (0.87%; aOR, 6.23; 95% CI, 1.22-26.8). Having an underlying high TE risk (aOR, 16.8; 95% CI, 6.33-46.6) was associated with higher postcolonoscopy TE events.

CONCLUSIONS

The risk of post-colonoscopy thromboembolic events is low. However, the temporary interruption of antithrombotic agents, particularly stopping 2 or more agents, clopidogrel, warfarin, or direct-acting oral anticoagulants was associated with higher postcolonoscopy TE events, particularly in high-risk patients.

[Comparison of intraoperative neurophysiological monitoring between patients with arthrogryposis multiplex congenita and adolescent idiopathic scoliosis]

Objective: To compare the intraoperative neurophysiological monitoring (IONM) results between patients with arthrogryposis multiplex congenita (AMC) and adolescent idiopathic scoliosis (AIS) and to analyze the influence of congenital spinal deformity on IONM in AMC patients, thus to evaluate the efficiency of IONM in AMC patients. Methods: A cross-sectional study. The clinical data of 19 AMC patients underwent correction surgery from July 2013 to January 2022 in Nanjing Drum Tower Hospital were retrospectively reviewed. There were 13 males and 6 females with a mean age of (15.2±5.6) years, and the average Cobb angle of main curve was 60.8°±27.7°. And 57 female AIS patients of similar age and curve type with the AMC patients during the same period were selected as the control group, with an average age of (14.6±4.4) years and a mean Cobb angle of 55.2°±14.2°. The latency and amplitude of samatosensory evoked potentials (SSEPs) and transcranial electric motor evoked potentials (TCeMEPs) were compared between the two groups. The difference in IONM data between AMC patients with and without congenital spinal deformity was also evaluated. Results: The success rates of SSEPs and TCeMEPs were 100% and 14/19 for AMC patients, 100% and 100% for AIS patients. The SSEPs-P40 latency, SSEPs-N50 latency, SSEPs-amplitude, TCeMEPs-latency, TCeMEPs-amplitude showed no significant difference between AMC patients and AIS patients (P>0.05 for all). The side-difference of TCeMEPs-amplitude showed an increasing trend in AMC patients when compared with that in AIS patients, but there was no statistical difference between the two groups [(147.0±185.6) μV vs (68.1±311.4) μV, P=0.198]. The SSEPs-amplitude value was (1.4±1.1) μV on concave side in AMC patients with congenital spinal deformity, and it was (2.6±1.2) μV on concave side in AMC patients without congenital spinal deformity (P=0.041). The SSEPs-amplitude value was (1.4±0.8) μV on convex side in AMC patients with congenital spinal deformity, and it was (2.6±1.3) μV on convex side in AMC patients without congenital spinal deformity (P=0.028). Conclusions: The values of SSEPs-P40 latency, SSEPs-N50 latency, SSEPs-amplitude, TCeMEPs-latency and TCeMEPs-amplitude are similar in AMC and AIS patients. The SSEPs-amplitude of AMC patients with congenital spinal deformity is lower than that of AMC patients without congenital spinal deformity.

OCTA biomarkers in adults aged 50 and above: a prospective and cross-sectional community-based study

BACKGROUND/AIMS

To assess the normative values and parameters of optical coherence tomography angiography (OCTA) influencing the best corrected visual acuity (BCVA) in adults aged 50 and above.

METHODS

This was a prospective cross-sectional study from an eye screening programme in Hong Kong for 4188 citizens aged 50 and above. Images were analysed using a validated quantification software calculating vessel density and capillary perfusion density (CPD), along with other OCTA parameters, such as the foveal avascular zone area (FAZ) and circularity. OCTA data was collected from May 2019 to December 2020, including a total of 4188 healthy eyes from 4188 subjects.

RESULTS

Mean superficial vessel density (MSVD) was 14.48 ± 3.60 mm^- 1, while the mean capillary perfusion density (MCPD) was 0.41 ± 0.06. Multivariate analysis revealed ageing (β = 0.321, p < 0.001), being male (β=-0.089, p < 0.001), having a high body mass index (BMI) (β = 0.039, p = 0.006), high FAZ area and low FAZ circularity (β = 0.039 and - 0.034, p = 0.01 and 0.024 respectively), low MSVD in the outer ring (β=-0.513, p < 0.001), specifically in the nasal and temporal outer quadrants (β = -0.226 and - 0.259, p < 0.001 for both), and low MCPD in the outer superior quadrant (β= -0.123, p = 0.016) being independently associated with BCVA.

CONCLUSION

High FAZ area and low FAZ circularity, low MSVD in the outer ring, specifically the nasal and temporal outer quadrants, and low MCPD in the outer superior quadrant can be used as biomarkers in predicting a low visual acuity in adults aged 50 and above.

[The related factors of postoperative recurrence in trigeminalneuralgia patients undergoing fully neuroendoscopic microvascular decompression]

Objective: To evaluate the related factors of postoperative recurrence intrigeminal neuralgia (TN) patients treated with fully neuroendoscopic microvascular decompression (MVD). Methods: The clinical baseline data and preoperative MRI imaging data of 112 patients with TN treated by neuroendoscopic MVD from December 2008 to December 2020 in the Department of Neurosurgery, Beijing Shijitan Hospital Affiliated to Capital Medical University were retrospectively analyzed, including: area ratio of cerebellopontine area (CPA)(healthy side/affected side), trigeminal nerve(TGN)length ratio(healthy side/affected side), TGN angle ratio(healthy side/affected side), and criminal vessel type. Multivariate Cox proportional hazards model was used to analyze the factors affecting postoperative recurrence. Results: Among the 112 patients in this group, there were 49 males and 63 females. The age ranged from 20 to 82 (59±9) years, and the course of disease was 0.05 to 30.00 (5.60±5.15) years. Pain was located on the left side in 43 cases (38.39%) and on the right side in 69 cases (61.61%), respectively. All patients were followed up for more than 1 year, with an average follow-up time of 21.5 months, and 11 cases recurred. Multivariate Cox regression analysis revealed that disease duration≥3 years(HR=9.34, 95%CI:1.12-39.07), CPA area ratio(healthy side/affected side)>1 (HR=27.47, 95%CI:1.69-44.20), criminal vessel type with vein(HR=35.39, 95%CI:1.26-18.60) and criminal vessel type with arteriovenous (HR=46.07, 95%CI: 2.74-27.75) were the main factors influencing recurrence of MVD surgery (all P<0.05). Conclusion: The disease duration≥3 years, CPA area ratio(healthy side/affected side)>1, and criminal vessel type with vein/arteriovenous are the relevant factors that affect the recurrence rate after the fully neuroendoscopic MVD treatment for trigeminal neuralgia.

COVID-19 vaccination in patients with rheumatic diseases: Vaccination rates, patient perspectives, and side effects

INTRODUCTION

To investigate the vaccination rate, reported side effects, and patient concerns for COVID-19 vaccination in patients with rheumatic diseases.

METHODS

A multicentre cross-sectional study from rheumatology clinics in two major hospitals in Hong Kong was conducted between June 3, 2021 and October 8, 2021. Patient interviews for demographics, clinical characteristics, vaccination status, reported side effects, and factors influencing decisions about vaccination were supplemented with structured questionnaires.

RESULTS

Out of 1367 patients, 413 (30.2%) had received COVID-19 vaccination. Side effects were reported in 335 (81.1%) of patients, of which the most common were injection site pain or swelling (66.3%), fatigue (57.1%), fever (19.9%), and headache (19.6%). Multivariate logistic regression models showed that males (odds ratio [OR] = 1.80; p < .001), higher education level (OR = 1.64; p < .001) and healthcare professionals (OR = 4.5; p < .001) were significantly more likely to have received the vaccine. In contrast, patients with hypertension (OR = 0.73; p = .04), systemic lupus erythematous (OR = 0.53; p < .001), stroke (OR = 0.29; p = .01), steroid therapy (OR = 0.59; p = .01), and leflunomide therapy (OR = 0.45; p = .05) were significantly less likely to be vaccinated. Younger age (age, OR = 0.96; p = .003) and messenger RNA (mRNA) vaccines (OR = 4.79; p < .001) were associated with more side effects. There was no difference in risk of side effects between specific rheumatic diseases or drug therapies.

CONCLUSION

COVID-19 vaccination is associated with no increased risk of side effects in any particular disease or drug therapy, therefore vaccination should be encouraged in patients with rheumatic disease. In addition, younger age is associated minimally, while mRNA vaccine is associated with increased side effects.

A prospective study of the impact of glycaemic status on clinical outcomes and anti-SARS-CoV-2 antibody responses among patients with predominantly non-severe COVID-19

AIMS

We carried out this prospective study of predominantly non-severe COVID-19 patients, to evaluate the influence of glycaemic status on clinical outcomes and neutralising antibody (Nab) responses, potentially relevant to the COVID-19 vaccination programme.

METHODS

We included consecutive adults admitted to Queen Mary Hospital for COVID-19 from July 2020-May 2021. Glycaemic status was defined by admission HbA1c. Clinical deterioration was defined by radiological progression/new oxygen requirement/intensive care requirement/death. COVID-19 survivors had Nab measurements at 1-month, 2-month, 3-month and 6-month post-discharge.

RESULTS

Among 605 patients (96.9% non-severe COVID-19; 325 normoglycaemia, 185 prediabetes, 95 diabetes), 74 (12.2%) had clinical deterioration, more likely with worse glycaemic status and higher HbA1c (p < 0.001). Older age (p < 0.001), higher viral loads (p < 0.001), higher C-reactive protein (CRP) (p < 0.001) and symptomatic presentation (p = 0.008), but not glycaemic status/HbA1c, independently predicted clinical deterioration. Older age (p = 0.001), higher CRP (p = 0.038), elevated lactate dehydrogenase (p = 0.046) and interferon treatment (p = 0.001), but not glycaemic status/HbA1c, independently predicted Nab titres. Rate of Nab titre decline was comparable across glycaemic status.

CONCLUSIONS

COVID-19 patients with worse glycaemic status were more likely to deteriorate clinically, mediated through the association of worse glycaemic status with older age, more severe inflammation and higher viral loads. Importantly, Nab responses did not differ across glycaemic status.

[Methylation detection of phosphatase and tensin homolog deleted on chromosome ten gene promoter in hepatocellular carcinoma samples by next-generation sequencing]

Objective: The purpose of this study is to use the next-generation sequencing (NGS) technology platform to detect the methylation rate of phosphatase and tensin homolog deleted on chromosome ten (PTEN) promoter region in hepatocellular carcinoma (HCC) tissue samples, and to analyze the clinical significance of its correlation with the prognosis of patients receiving sorafenib treatment. Methods: The 52 pairs of tumor tissue and para-cancerous tissue samples from HCC patients treated with sorafenib alone, which were collected and preserved in the Liver Tumor Diagnosis and Research Center of the former 302 Hospital of the People's Liberation Army by the National Natural Science Foundation of China Youth Project with the project batch number 81702986 in 2018, were extracted total DNA from the samples. Then the DNA samples were treated with bisulfite and specific primers were designed to amplify the PTEN promoter region. Finally, the amplified products were analyzed by second-generation sequencing. In the analysis of clinical significance of PTEN methylation, log-rank statistical analysis was used to calculate whether there was a statistical difference in survival between the patient groups. Results: The methylation rate of PTEN promoter region in tumor tissues (29.17%±9.58%) was significantly higher than that in paracancer tissues (4.17%±2.86%)(t=19.970,P<0.05). At the same time, in HCC tissues, the methylation rate of the PTEN promoter region is negatively correlated with its expression (F=47.270,P<0.000 1;Y=-1 800×X+38.03), and the PTEN methylation rate is negatively correlated with the prognosis of patients receiving the molecularly targeted drug Sorafenib (χ²=4.313,P<0.05). Conclusion: This study successfully established a new method for detecting methylation in the promoter region of PTEN, and the methylation rate of PTEN can be used as one of the targets of HCC diagnosis and targeted therapy.

[A challenge for colorectal surgeons: pathogenesis, progression and management of the secondary tumors of the ovary]

A common clinical problem encountered by colorectal surgeons is the secondary tumors of the ovary (STO), particularly in young female patients. Most STO are from the digestive tract, and the known possible metastatic mechanisms include lymphatic, hematogenous, and intraperitoneal spreading. The molecular and histopathological characteristics of STO from different sites are diverse. It is particularly important to correctly identify the origin and feature of STO, which should be clarified by combining medical history, histopathology, immunohistochemistry, molecular biology, imaging and other means. The prognosis of patients with STO is poor in general. Comprehensive therapies based on surgical resection can benefit some patients. There is no specific treatment for STO at present, but not giving up easily on these patients is the right choice that every surgeon should understand.

[Clinical significance of ascitic interleukin-7 expression levels in cirrhotic patients complicated with spontaneous bacterial peritonitis]

Objective: To observe ascitic interleukin-7 expression level in cirrhotic patients complicated with spontaneous bacterial peritonitis, and to detect the effect of recombinant human IL-7 on CD4(+) and CD8(+)T lymphocyte function. Methods: A total of 84 patients with liver cirrhosis who were hospitalized from August 2017 to April 2018 were selected. Among them, 51 cases were complicated with cirrhosis and untainted ascites, and 33 cases were cirrhosis complicated with spontaneous bacterial peritonitis. Peripheral blood and ascites were collected routinely. The levels of IL-7 in peripheral blood and ascites were measured by enzyme-linked immunosorbent assay. CD4(+)T cells and CD8(+)T cells were purified from ascites, and were stimulated with recombinant IL-7. Cellular proliferation, key transcription factors for mRNA, and cytokines production by CD4(+)T cells in response to IL-7 stimulation was measured. mRNA expression corresponding to perforin, granzyme B, and granulysin as well as cytokines production by CD8(+)T cells was also measured in response to IL-7 stimulation. Cytolytic and non-cytolytic activity of CD8(+)T cells in response to IL-7 stimulation was also investigated in both direct and indirect contact co-culture system. Measurement data of the normal distribution were compared between the two groups by Student's t-test and the data before and after stimulation were compared by paired t-test. Measurements that did not conform to normal distribution were compared between the two groups using Mann-Whitney U test, and data before and after stimulation were compared using Wilcoxon paired test. Results: There was no significant statistical difference in serum IL-7 levels between the two groups [(5 001 ± 1 458) pg/ml vs. (4 768 ± 1 128) pg/ml, P = 0.41]. The level of ascitic IL-7 in cirrhotic patients complicated with SBP was significantly lower than cirrhosis patients with untainted ascites [(966.4 + 155.8) pg/ml vs. (792.1 + 126.4) pg/ml, P < 0.01]. Recombinant IL-7 stimulation promoted the proliferation of CD4(+) and CD8(+)T cells from ascites in patients with liver cirrhosis complicated by SBP. T-bet mRNA relative expression and IFN-γ secretion in CD4(+)T cells was also elevated in response to IL-7 stimulation in vitro. Moreover, IL-7 stimulation also increased the mRNA expressions of perforin, granzyme B, and granulysin as well as productions of IFN-γ and TNF-α by CD8(+)T cells. Recombinant IL-7 stimulation elevated cytolytic and non-cytolytic activity of CD8(+)T cells from ascites in patients with liver cirrohosis complicated by SBP, which manifested as increased target cell death and IFN-γ production in both direct and indirect contact co-culture system. Conclusion: Ascitic IL-7 promotes T lymphocyte function in patients with liver cirrhosis complicated with SBP.

[Hepatitis B core antigen promotes invasion of hepatocellular carcinoma cell line HepG2.2.15 via Toll-like receptor 4]

Objective: To investigate the effect of hepatitis B core antigen (HBcAg) in promoting the invasion of hepatitis B virus (HBV)-related hepatocellular carcinoma cell line HepG2.2.15 and the role of Toll-like receptor 4 (TLR4) in the mechanism. Methods: TLR4 mRNA and protein expression in HepG2 cells and HepG2.2.15 cells was measured by reverse transcription real-time PCR and Western blot analysis, respectively. HepG2.2.15 cells were transfected with TLR4 specific small interfering RNA (siRNA) to silence TLR4 expression, and stimulated by recombinant HBcAg in culture. The invasion of cells was measured by Transwell invasion assay. The expression of TLR4 signaling pathway-related proteins in the cultured cells and proinflammatory cytokines in the supernatant was also determined. The student's t-test, one-way ANOVA, and SNK-q test were used for statistical analysis. Results: TLR4 mRNA and protein expression in HepG2.2.15 cells was significantly higher than that in HepG2 cells. TLR4 siRNA transfection remarkably down-regulated TLR4 expression in HepG2.2.15 cells. Inhibiting TLR4 expression and/or HBcAg stimulation did not affect the proliferation of HepG2.2.15 cells. However, HBcAg stimulation significantly increased the invasion ability of HepG2.2.15 cells and the secretion of proinflammatory cytokines [including interferon (IFN)-γ, interleukin (IL)-6, IL-8, and tumor necrosis factor (TNF)-α]. Inhibiting TLR4 expression significantly reduced HBcAg-induced cellular invasion. Meanwhile, HBcAg stimulation elevated the expression of MyD88 and TRIF in HepG2.2.15 cells. TLR4 silencing inhibited HBcAg-induced increase in the expression of MyD88, while it showed no significant impact on TRIF expression. Conclusion: HBcAg can promote the invasion of HepG2.2.15 cells. The TLR4/MyD88 signaling pathway may be involved in this process by inducing the expression of proinflammatory cytokines.

[Relationships between serum cystatin C, chemerin levels and subclinical atherosclerosis in type 2 diabetes mellitus patients]

Objective: To investigate the relationships between serum cystatin C (Cys C), chemerin levels and subclinical atherosclerosis in type 2 diabetes mellitus (T2DM) patients. Methods: A cross-sectional study was carried out between January 2016 and January 2018, and T2DM patients with carotid intima-media thickness (IMT) less than 1.1 mm were selected as subjects (100 males and 80 females, aged 40-60 years). The brachial-ankle pulse wave velocity (baPWV) ≥ 1 700 cm/s was set as the observation group (subclinical atherosclerosis) and baPWV<1 700 cm/s as the control group (non-subclinical atherosclerosis). Physical and blood examination were performed in both groups. Serum Cys C and chemerin levels were measured and their relationship with subclinical atherosclerosis was analyzed. Results: There was a statistically significant correlation between serum creatinine (r=0.167, P=0.011) and baPWV in the observation group, but not in the control group (r=0.105, P=0.070). Multiple linear regression analysis showed that age, duration of diabetes, serum creatinine, estimated glomerular filtration rate (eGFR), Cys C and chemerin were independently associated with baPWV, while high sensitive C reactive protein (hsCRP) and glycosylated hemoglobin (HbA1c) were not associated with baPWV. The elevation of serum Cys C (β'=0.393, P=0.003) and chemokine (β'=0.340, P=0.007) were correlative factors for atherosclerosis. Conclusion: The level of serum Cys C and chemerin is possibly related to the occurrence and development of subclinical atherosclerosis in T2DM patients.

A Lady with Confusion and Seizure after Ingestion of Lidocaine for Dyspepsia

We report a 29-year-old lady who developed confusion, agitation and seizure after the ingestion of a self-mixture of 3 grams of lidocaine with antacid for treatment of dyspepsia. She developed two episodes of seizure requiring diazepam, propofol and intubation. There was no significant cardiac toxicity and she was discharged on day 3. This is the first reported adult case of seizure in the literature after intentional ingestion of lidocaine for treatment of dyspepsia. The use of local anaesthetic in gastrointestinal cocktail for dyspepsia and its safety are highlighted. Advances in the management of local anaesthetic overdose are also discussed.

Acute Urinary Retention: How Useful is an Ambulatory Care Protocol?

Introduction

Acute urinary retention (AUR) is a common urological presentation to emergency departments (ED). An ambulatory care protocol had been developed allowing trial without catheterization (TWOC) instead of admission to hospital after catheterization in the ED. This study aimed to evaluate the efficacy of the ambulatory care protocol for patients with AUR. The secondary aim was to identify any independent predictor(s) for successful weaning of urinary catheter in a short duration.

Methods

This was a prospective cohort study. A total of 143 male patients presenting with an episode of AUR underwent urinary catheterization once. Those who were unable to pass urine afterwards were catheterized again and discharged home with a urinary catheter in-situ (Day 0). On Day 3, ability of spontaneous urination was assessed. If failed, spontaneous urination was assessed again on Day 6.

Results

Successful TWOC was recorded in 50.3% of the 143 patients after first catheterization. The cumulative successful rates for first (Day 3) and second (Day 6) follow-ups were 76.9% and 79.0%, respectively. Among the associated predictors, only the urine retention volume on first catheterization was found to be independently associated with successful TWOC, using binary logistic regression (p=0.001).

Conclusion

The ambulatory care protocol was successful in weaning off urinary catheter for 50.3% of patients with AUR after first catheterization and a further 26.6% on Day 3, making a cumulative success rate of 76.9%. Those who failed TWOC on Day 3 would get little benefit on further trials. The first catheterization volume was independently associated with the chance of successful TWOC.

Visual working memory deterioration preceding relapse in psychosis

BACKGROUND

Relapse is distressingly common after the first episode of psychosis, yet it is poorly understood and difficult to predict. Investigating changes in cognitive function preceding relapse may provide new insights into the underlying mechanism of relapse in psychosis. We hypothesized that relapse in fully remitted first-episode psychosis patients was preceded by working memory deterioration.

METHOD

Visual memory and verbal working memory were monitored prospectively in a 1-year randomized controlled trial of remitted first-episode psychosis patients assigned to medication continuation (quetiapine 400 mg/day) or discontinuation (placebo). Relapse (recurrence of positive symptoms of psychosis), visual (Visual Patterns Test) and verbal (Letter-Number span test) working memory and stressful life events were assessed monthly.

RESULTS

Remitted first-episode patients (n = 102) participated in the study. Relapsers (n = 53) and non-relapsers (n = 49) had similar baseline demographic and clinical profiles. Logistic regression analyses indicated relapse was associated with visual working memory deterioration 2 months before relapse [odds ratio (OR) 3.07, 95% confidence interval (CI) 1.19-7.92, P = 0.02], more stressful life events 1 month before relapse (OR 2.11, 95% CI 1.20-3.72, P = 0.01) and medication discontinuation (OR 5.52, 95% CI 2.08-14.62, P = 0.001).

CONCLUSIONS

Visual working memory deterioration beginning 2 months before relapse in remitted first-episode psychosis patients (not baseline predictor) may reflect early brain dysfunction that heralds a psychotic relapse. The deterioration was found to be unrelated to a worsening of psychotic symptoms preceding relapse. Testable predictors offer insight into the brain processes underlying relapse in psychosis.

The Nutritive Values in Different Varieties of Corn Planted in One Location Fed to Growing Pigs over Three Consecutive Years

This experiment was conducted to determine the effect of variety and planting year on the nutritive values of corn fed to growing pigs. Four corn varieties examined in this experiment were planted in the same village located in Longhua County, Heibei Province, China, in 2012, 2013, and 2014, respectively. During each year, corn was hand-harvested in early October and sun dried to about 14% moisture content. Three batches of twenty-four barrows (33.27±4.30, 31.88±2.93, 34.21±3.81 kg body wight [BW] in 2012, 2013, and 2014, respectively) were used and allotted to a complete block design with 4 diets and 6 replicate pigs per diet. Pigs were individually placed in metabolic crates. The four experimental diets were formulated by mixing each variety of corn and vitamins and minerals, respectively. A five-day collection period followed a seven-day diet acclimation period. The results indicated that variety of corn significantly influenced the available energy content (digestible energy [DE] on dry matter basis, p<0.05; metabolizable energy (ME) on dry matter basis, p<0.05, respectively), and the apparent total tract digestibility (ATTD) of organic matter (p<0.01), dry matter (p<0.05), gross energy (p<0.05), neutral detergent fiber (p<0.01), acid detergent fiber and ether extract (p<0.05). The planting year also significantly influenced the available energy contents (DE on dry matter basis, p<0.05; ME on dry matter basis, p<0.01, respectively) and the ATTD of neutral detergent fiber (p<0.01), acid detergent fiber (p<0.01), crude protein (p<0.01), and ether extract (p<0.01). No interaction was observed between the variety and planting year in DE and ME contents in corn. In conclusion, the variety and planting year significantly influenced the available energy and nutrient digestibility of corn fed to growing pigs.

Efficient construction of recombinant adenovirus expression vector of the Qinchuan cattle LYRM1 gene

In this study, we cloned the coding DNA sequence (CDS) region of Qinchuan cattle LYR motif-containing 1 (LYRM1) and constructed a recombinant adenovirus expression vector to examine the function of LYRM1 on the cellular level. Total RNA was extracted from the adipose tissue of Qinchuan cattle, cDNA was obtained by reverse transcription, and polymerase chain reaction was used to amplify the CDS region of the LYRM1 gene. The CDS-containing fragment was inserted into the shuttle vector pAdTrack-CMV to construct pAdTrack-CMV-LYRM1 vector. After linearization of pAdTrack-CMV-LYRM1 and the negative control vector pAdTrack-CMV by restriction endonuclease PmeI, the vectors were transformed into Escherichia coli BJ5183 containing pAdEasy-1 to obtain the recombinant adenovirus vector pAd-LYRM1 and pAd-CMV through homologous recombination. pAd-LYRM1 and pAd-CMV were then digested by PacI and transfected into the 293A cell line. The recombinant adenovirus Ad-LYRM1 and Ad-CMV was obtained at a concentration of 7 x 108 and 1.3 x 109 green fluorescent units/mL, respectively. Preadipocytes derived from Qinchuan cattle were separately infected with Ad-LYRM1 and Ad- CMV. Quantitative real-time polymerase chain reaction demonstrated that the expression of LYRM1 was increased by approximate 28,000-folds after the infection with recombinant adenovirus for 48 h. In conclusion, we successfully cloned the CDS region of the Qinchuan cattle LYRM1 gene, constructed the recombinant adenovirus expression vector, and obtained the adenovirus with high titer, providing valuable materials for studying the function of LYRM1 at the cellular level.

Osteoblast proliferation is enhanced upon the insulin receptor substrate 1 overexpression via PI3K signaling leading to down-regulation of NFκB and BAX pathway

The insulin receptor substrate 1 (IRS1) promotes bone formation via osteoblast proliferation mediated by PI3K/Akt signaling. A reduction in NFκB activity in osteoblasts results in an increase in bone formation. The NFκB signaling pathway leads to increased expression of BAX, which contributes to osteoblast apoptosis. The purpose of this study was to investigate the expression of recombinant plasmid enhanced green fluorescent protein-N1 (pEGFP-N1) that transferred IRS1 gene into osteoblasts in vitro and evaluate the effects of IRS1 overexpression on NFκBp65 and on BAX. Osteoblasts were transfected with pEGFP-N1 or pEGFP-N1 encoding wild-type IRS1 (pEGFP-N1-IRS1). Cell cycle analysis was performed using flow cytometry. The expression levels of NFκBp65 and BAX were measured by Western blotting. Our results revealed that overexpression of IRS1 stimulated osteoblast proliferation, as evidenced by an increase in the number of cells in the S phase compared to controls. IRS1 overexpression in osteoblasts activated the PI3K/Akt pathway, and inhibited expression of NFκBp65 and BAX. When osteoblasts transfected with pEGFP-N1-IRS1 were exposed to a PI3K inhibitor (LY294002), the effects of IRS1 overexpression were reversed. On the basis of our study, it seems that osteoblasts proliferated upon IRS1 overexpression due to inhibition of the NFκB pathway and downregulation of BAX through PI3K/Akt signaling.

Effects of bovine SMO gene polymorphisms on the body measurement and meat quality traits of Qinchuan cattle

Beef cattle breeding programs focus on improving important economic traits, including growth rates, and meat quantity and quality. Molecular marker-assisted selection based on genetic variation represents a potential method for breeding genetically improved livestock with better economic traits. Smoothened (SMO) protein is a signal transducer that contributes to the regulation of both osteogenesis and adipogenesis through the hedgehog pathway. In this study, we detected polymorphisms in the bovine SMO gene of Qinchuan cattle, and we analyzed their associations with body measurement traits (BMTs) and meat quality traits (MQTs). Using DNA sequencing and polymerase chain reaction-restriction fragment length polymorphism, 3 novel single nucleotide polymorphisms were identified in the SMO gene of 562 cattle: 1 G > C mutation on exon 9 (G21234C) and 2 C > T mutations on exon 11 (C22424T and C22481T). Association analysis showed that polymorphisms on both the G21234C and C22424T loci significantly affected certain BMTs and MQTs (P < 0.05 or P < 0.01), whereas those on the C22481T locus did not (P > 0.05). Therefore, the SMO gene could be used as a candidate gene to alter BMTs and MQTs in Qinchuan cattle or for marker-assisted selection to breed cattle with superior BMTs and MQTs.

Polymorphisms in the delta-like 2 homolog gene and their association with growth and meat-quality traits in Qinchuan cattle

The delta-like 2 homolog (DLK2) modulates adipogenesis, hematopoiesis, osteogenesis, and other cell-differentiation processes. In the present study, we detected potential polymorphisms in the DLK2 gene in 604 individuals of Qinchuan cattle by using PCR-RFLP and DNA-sequencing methods. Herein, we identified five novel single-nucleotide polymorphisms (SNPs) (g.888G>A, g.910A>G, g.995G>A, g.4321A>G, g.4850A>G) and analyzed their association with measured traits. Four of the five analyzed polymorphisms were associated with at least one of the following traits: body weight (BW), chest depth (CD), chest circumference (CC), back fat thickness (BT), and rib-eye area (REA). To the best of our knowledge, our research is the first to report the association of DLK2 gene polymorphisms with growth and meat quality traits in Qinchuan cattle. In summary, the results of our study suggest that the DLK2 gene can be used as a candidate gene in beef cattle breeding.

New polymorphisms in the novel LYRM1 gene are associated with body measurement and meat quality traits in Qinchuan cattle

Body measurement and meat quality traits play important roles in the evaluation of productivity in cattle; they are influenced by genetic and environmental factors. Recent studies have shown that LYRM1 is a novel gene related to obesity and may influence fat deposition. We screened for new polymorphisms in the bovine LYRM1 gene and analyzed their association with body measurement and meat quality traits in cattle. DNA samples were obtained from 572 Qinchuan cattle aged from 18 to 24 months. DNA sequencing was used to find the LYRM1 single nucleotide polymorphisms (SNPs). Sequence analysis of LYRM1 revealed four novel SNPs in exon 3: G50A in coding region, C126A, A127T, and T128A in a 3'-untranslated region. G50A, A127T and T128A showed two genotypes: AG and GG, AA and AT, AT and TT, respectively; while C126A showed three genotypes: AA, AC and CC. Analysis showed that these four polymorphisms were significantly associated with body measurement and meat quality traits in the Qinchuan cattle population. We suggest that the LYRM1 gene can be used for marker-assisted selection to improve body measurement and meat quality traits in the Qinchuan cattle population.

Who are Prone to Develop Adverse Effects with Oral Tramadol? a Retrospective Cohort Study

Objective

Oral tramadol is a commonly prescribed analgesic in Hong Kong. Significant adverse effects are frequently observed in our locality. Our study aims to describe the rate of significant adverse effect that warrant discontinuation of oral tramadol and identify the risk factors for development of adverse effect.

Design

Retrospective cohort study.

Methods

Adult patients aged greater than 18 years old admitted to the emergency medicine ward of a large-scale local hospital in Hong Kong being prescribed with oral tramadol during in-hospital stay were recruited. Significant adverse effects during the hospital stay were observed as the outcome of interest.

Results

A total of 575 subjects were recruited. 29.9% experienced significant adverse effects likely related to tramadol. Age (p=0.006; odds ratio [OR] = 1.017, 95% confidence interval [CI] = 1.005-1.029) and sex (p=0.006; OR=1.696, 95% CI= 1.166-2.465) were statistically significant predictors of adverse effects after oral tramadol.

Conclusion

Our study suggests that female and increasing age patients are significant predictors for the development of adverse effect after taking oral tramadol. Possible adverse effects should be explained to the patients careful especially the higher risk groups. (Hong Kong j. emerg.med. 2014;21:3-9)

Novel SNPs in the exon region of bovine DKK4 gene and their association with body measurement traits in Qinchuan cattle

The aim of this study was to determine whether single nucleotide polymorphisms (SNPs) of bovine Dickkopf homolog 4 (DKK4) are associated with body measurement traits in Qinchuan cattle. By using PCR-SSCP technology and DNA sequencing, we discovered 5 DKK4 SNPs in Qingchuan cattle, including -65G>A and -77G>T in the 5'-untranslated region, 1532C>G and 1533T>C in exon 2, and 2088C>T in exon 3. The sequencing map showed that 1532C>G and 1533T>C were in close linkage disequilibrium and were treated as 1532C>G-1533T>C in this study. Allele frequencies were calculated and analyzed by the chi-square test, which showed that -65G>A and 1532C>G-1533T>C were in Hardy-Weinberg equilibrium (P > 0.05), whereas -77G>T and 2088C>T were not in all 633 tested Qinchuan cattle individuals (P < 0.01). Gene heterozygosity (HE), effective allele number (NE), and polymorphism information content (PIC) were 0.407, 1.686, and 0.324 at -65G>A; 0.472, 1.894, and 0.361 at -77G>T; 0.476, 1.908, and 0.363 at 1532C>G-1533T>C; and 0.218, 1.279, and 0.195 at 2088C>T. We also evaluated the potential association of these SNPs with body measurement traits in all 633 individuals; the results suggest that several SNPs in Qinchuan cattle DKK4 were significantly associated with body length, hip height, rump length, hip width, heart girth, and pin bone width (P < 0.05 and P < 0.01). These results suggest that bovine DKK4 could be used as candidate gene for Qinchuan cattle breeding.

Effect of Zn impurity in K0.8Fe(2-δ-x)Zn(x)Se2

A series of K(0.8)Fe(2-δ-x)Zn(x)Se(2) single-crystal samples with nominal compositions 0 ≤ x ≤ 0.05 were grown and their physical properties were measured in order to study the effect of Zn impurity. It is found that the Zn impurity (x ≤ 0.02) does not affect the superconducting transition temperature T(c) significantly. Meanwhile the hump in resistivity which corresponds to the transition from the insulating to metallic phase quickly shifts towards low temperatures. The results imply that there should be a phase separation in this system and Zn impurity causes the enhancement of the insulating phase. The negligible effect of Zn impurity on T(c) suggests an s-wave pairing in the superconducting phase. Meanwhile there is a possibility that the Zn impurity may selectively enter into the insulting phase.

Superconductivity induced by Ni doping in SmFe(1-x)Ni(x)AsO

Superconductivity with a T(c) of about 10 K is observed in the Ni-doped SmFe(1-x)Ni(x)AsO system. The measurements of resistivity and magnetic susceptibility show that the spin-density wave (SDW) order is quickly suppressed with increasing Ni content, and superconductivity emerges as x≥0.04. T(c)(mid) shows a maximum of 10.8 K at x = 0.06, and it drops to lower than 2 K as x>0.12. Meanwhile, the upper critical field (H(c2)(0)) is estimated to be about 40 T for the optimally-doped sample (x = 0.06). The normal state thermopower is negative for all the Ni-doped samples, indicating that an electron-type charge carrier dominates in the transport properties. Moreover, the magnitude of the room-temperature thermopower increases with increasing Ni content, and then shows a broad peak around x = 0.06. We found that there is an obvious correlation between the anomalously enhanced thermopower and superconductivity. A phase diagram is derived based on the transport measurements and a dome-like T(c)(x) curve is established.

Early diffusion weighted imaging and expression of heat shock protein 70 in newborn pigs with hypoxic ischaemic encephalopathy

OBJECTIVE

To establish a cerebral hypoxia ischaemic model in piglets and to explore the early diffusion weighted imaging (DWI) as well as the expression of heat shock protein 70 (HSP70) with hypoxic ischaemic encephalopathy (HIE).

METHODS

Twenty four 3 day old piglets were permanently ligated common carotid arteries bilaterally and ventilated with 3% oxygen for 30 minutes, and their brains were examined at three hours, six hours, and 24 hours after hypoxic ischaemia with T2 weighted images and diffusion weighted images. Apparent diffusion coefficient (ADC) values were measured and HSP70 expression was detected in the central and peripheral regions of lesions.

RESULTS

Abnormal signal intensity was detected on DWI and ADC maps in three hypoxic ischaemic groups. ADC values in the central lesions rapidly decreased, whereas ADC values in the peripheral regions reduced prominently at 24 hours after hypoxic ischaemia. There were significant differences (p<0.01) between ADC values of the central regions and the peripheral regions of lesions. The number of HSP70 positive cells was low at three hours, raised at the highest peak at six hours, and then rapidly decreased. There was statistical difference between HSP70 positive cells in the central regions and those in peripheral regions (p<0.01).

CONCLUSION

DWI may identify more early lesions, and improve conspicuity in the acute setting. ADC values can be used as an objective measure for hypoxic ischaemic injury. Tissue reversibility can be further reflected according to the information of ADC values and HSP70 immunohistochemical staining.

Catalytic mechanism of a family 3 beta-glucosidase and mutagenesis study on residue Asp-247

A family 3 beta-glucosidase (EC 3.2.1.21) from Flavobacterium meningosepticum has been cloned and overexpressed. The mechanistic action of the enzyme was probed by NMR spectroscopy and kinetic investigations, including substrate reactivity, secondary kinetic isotope effects and inhibition studies. The stereochemistry of enzymic hydrolysis was identified as occurring with the retention of an anomeric configuration, indicating a double-displacement reaction. Based on the k(cat) values with a series of aryl glucosides, a Bronsted plot with a concave-downward shape was constructed. This biphasic behaviour is consistent with a two-step mechanism involving the formation and breakdown of a glucosyl-enzyme intermediate. The large Bronsted constant (beta=-0.85) for the leaving-group-dependent portion (pK(a) of leaving phenols >7) indicates substantial bond cleavage at the transition state. Secondary deuterium kinetic isotope effects with 2,4-dinitrophenyl beta-D-glucopyanoside, o-nitrophenyl beta-D-glucopyanoside and p-cyanophenyl beta-D-glucopyanoside as substrates were 1.17+/-0.02, 1.19+/-0.02 and 1.04+/-0.02 respectively. These results support an S(N)1-like mechanism for the deglucosylation step and an S(N)2-like mechanism for the glucosylation step. Site-directed mutagenesis was also performed to study essential amino acid residues. The activities (k(cat)/K(m)) of the D247G and D247N mutants were 30000- and 200000-fold lower respectively than that of the wild-type enzyme, whereas the D247E mutant retained 20% of wild-type activity. These results indicate that Asp-247 is an essential amino acid. It is likely that this residue functions as a nucleophile in the reaction. This conclusion is supported by the kinetics of the irreversible inactivation of the wild-type enzyme by conduritol-B-epoxide, compared with the much slower inhibition of the D247E mutant and the lack of irreversible inhibition of the D247G mutant.

Rapid process for purification of an extracellular beta-xylosidase by aqueous two-phase extraction

A rapid process for purification of an extracellular beta-xylosidase with high purity was developed. The manipulation involved the precipitation of protein from culture medium and the extraction of enzyme from the resuspended crude protein solution by an aqueous-two phase separation. A linear random copolymer, PE62, with 20% ethylene oxide and 80% propylene oxide was employed in both stages of the purification. The enzyme was precipitated effectively by using 10% (w/v) PE62 and 5% (w/v) Na2HPO4. The aqueous two-phase extraction was performed with PE62 (10%)-NaH2PO4 (15%) as phase-forming reagent. SDS-PAGE analysis revealed that the purified enzyme is near homogeneity. The yield is about 100% with a purification factor of 8.8-fold. The whole process can be completed within an hour without any column chromatography.

Pulmonary haemorrhage in a patient with Kikuchi disease

Kikuchi disease is an immunologic disease and most commonly presents with cervical lymphadenopathy. It is usually self-limiting [1]. It is sometimes associated with systemic lupus erythematosus (SLE) [2], and can be associated with many complications including aseptic meningitis, neuropathy, brachial neuritis. It can also be associated with lymphoma, and may sometimes be misdiagnosed as such [3]. The following is the first reported case of Kikuchi disease associated with pulmonary haemorrhage. The patient died and no other cause of the pulmonary haemorrhage could be identified at post mortem.

An Aspergillus chitosanase with potential for large-scale preparation of chitosan oligosaccharides

A chitosan-degrading fungus, designated Aspergillus sp. Y2K, was isolated from soil. The micro-organism was used for producing chitosanase (EC 3.2.1.132) in a minimal medium containing chitosan as the sole carbon source. The induced chitosanase was purified to homogeneity from the culture filtrate by concentration and cationic SP-Sepharose chromatography. The purified enzyme is a monomer with an estimated molecular mass of 25 kDa by SDS/PAGE and of 22 kDa by gel-filtration chromatography. pI, optimum pH and optimum temperature values were 8.4, 6.5 and 65-70 degrees C, respectively. The chitosanase is stable in the pH range from 4 to 7.5 at 55 degrees C. Higher deacetylated chitosan is a better substrate. Chitin, xylan, 6-O-sulphated chitosan and O-carboxymethyl chitin were indigestible by the purified enzyme. By endo-splitting activity, the chitosanase hydrolysed chitosan to form chitosan oligomers with chitotriose, chitotetraose and chitopentaose as the major products. The enzyme hydrolyses chitohexaose to form chitotriose, while the chitopentaose and shorter oligomers remain intact. The N-terminal amino acid sequence of the enzyme was determined as YNLPNNLKQIYDDHK, which provides useful information for further gene cloning of this enzyme. A 275 g-scale hydrolysis of chitosan was performed. The product distribution was virtually identical to that of the small-scale reaction. Owing to the simple purification process and high stability of the enzyme, it is potentially valuable for industrial applications.

Effective induction, purification and characterization of Trichoderma koningii G-39 beta-xylosidase with high transferase activity

A beta-xylosidase was induced and purified from the culture filtrate of Trichoderma koningii G-39, grown in a medium containing 1% oat spelts xylan and 0.1% xylose. The presence of xylose unequivocally enhanced the induction of beta-xylosidase. The purified enzyme, which exhibited a significant alpha-arabinosidase activity, was obtained with high yield simply via ethanol precipitation and a single anion-exchange chromatography and was characterized as a monomeric glycoprotein with an estimated molecular mass of 104 kDa and a pI of 4.6. The K(m) values towards p-nitrophenyl beta-D-xylopyranoside and p-nitrophenyl alpha-L-arabinopyranoside are 0.04 and 7.5 mM, respectively. It is stable at pH 2.5-7.4, 37 degrees C. The pH and temperature optima are in the range of 3.5-4.0 and 55-60 degrees C, respectively. Contrary to most beta-xylosidases from other sources, Hg(2+) (up to 25 mM) has no effect on enzyme activity. Xylose was shown to inhibit the purified enzyme with a moderate K(i) value of 5 mM. The enzyme exhibited transxylosylation activity and was characterized as a 'retaining' enzyme, catalysing the hydrolysis of substrate with the retention of anomeric configuration.

Mechanistic study of beta-xylosidase from Trichoderma koningii G-39

The catalytic mechanism of the beta-xylosidase purified from the culture filtrate of Trichoderma koningii G-39 was investigated. By NMR spectroscopy, the stereochemistry of the enzyme catalyzing the hydrolysis of 2,4-dinitrophenyl and p-nitrophenyl-beta-D-xylosides was found unequivocally to involve retention of the anomeric configuration. Based on the k(cat) values of a series of arylxylosides with leaving group pK(a)s in the range of 4-10, an extended Bronsted plot was constructed with a slope (beta(lg)) near zero. Enzymatic hydrolysis of aryl-beta-D-xylosides in acetate buffer (pH 4.0) containing 3 or 5% methanol showed a constant product ratio (methylxyloside/xylose), indicating the presence of a common intermediate, probably the xylosyl-enzyme intermediate. In the presence of DTT, the k(cat) values of p-cyanophenyl-beta-D-xylopyranoside and p-nitrophenyl-beta-D-xylopyranoside increased greatly. A two-step mechanism involving the formation and breakdown of the xylosyl-enzyme intermediate was therefore proposed. The rate-limiting step is the breakdown of the intermediate. The secondary deuterium kinetic isotope effect (k(H)/k(D)) measured for 2,4-dinitrophenyl-beta-D-xyloside was 1.02+/-0.01, suggesting that the transition state for breakdown of the xylosyl-enzyme intermediate is S(N)2-like.

Changes and implications of blood flow velocity of the vertebral artery during rotation and extension of the head

OBJECTIVE

To study the effects of extension and extension-rotation of the head on the blood flow velocity of the vertebral artery experimentally and clinically.

DESIGN

Randomized experimental clinical study.

SETTING

Institute of Clinical Anatomy and Biomechanics and the Department of Ultrasound, NanFang Hospital of the First Military Medical University, Guangzhou, China.

SUBJECTS

The fresh spines from T1-2 to the occipital bone were obtained from persons who died of acute brain death (n = 10). For the transcranial Doppler measurement, 27 asymptomatic subjects with routine physical examination results and 23 students from the above-mentioned university took part in the test.

INTERVENTIONS

The instillation experiment in the cadavers was made. Clinical measurements of blood flow velocity in the vertebral artery in the subjects and students were taken and recorded.

MAIN OUTCOME MEASURES

Changes in the drop of the vertebral artery were measured by the instillation test in the experimental sample. The blood flow velocity was measured with transcranial Doppler sonography during extension and extension-rotation of the head.

RESULTS

During one-sided rotation of the head with extension of the head, measurements in the contralateral vertebral artery and the bilateral vertebral arteries were both reduced in the instillation experiment. The blood flow velocity in the bilateral vertebral arteries decreased during extension and extension-rotation of the head in the subjects and the students. The pulsatility index in the right vertebral arteries increased more than that in the left in extreme extension and that in the bilateral vertebral arteries in neutral position.

CONCLUSIONS

Extreme rotation and extension are dangerous to patients who have abnormal vertebral arteries when extreme rotatory and extension manipulations are applied. Doctors should be very careful when rotating the patient's head to the right side.

Diagnostic value on signs of subluxation of cervical vertebrae with radiological examination

OBJECTIVE

To investigate the relationship between radiographic signs of subluxation in the cervical vertebrae and their clinical diagnostic value.

DESIGN

Controlled, clinical study.

SETTING

Institute of Clinical Anatomy and Biomechanics and NanFang Hospital of the First Military Medical University, Guangzhou, China.

SUBJECTS

Eighty-seven subjects with cervicodynia and 21 asymptomatic volunteers.

INTERVENTIONS

Radiological signs of subluxation from anteroposterior, lateral, open-mouth and dynamic radiographs of the cervical vertebrae of the subjects were measured and analyzed.

MAIN OUTCOME MEASURES

The right and left odontoid lateral mass interspace, divergence of the spinous processes, sign of double contour and position of odontoid process were studied.

RESULTS

The bilateral odontoid lateral mass interspaces were asymmetrical in most cases, and the divergence of spinous processes, sign of double contour and position of odontoid process were also common. Cervical vertebrae C5, C4 and C6 showed no special variations.

CONCLUSION

There was little evidence to support the contention that signs of subluxation in the cervical vertebrae are of diagnostic significance. Subluxation should be defined in two ways: as a purely roentgenological diagnosis and as a combination of roentgenological signs with clinical signs.

Spinal manipulation in China

BACKGROUND

Although there is a long history of the use spinal manipulation in China, little has been formally written on this topic.

OBJECTIVE

To discuss the history and status of Chinese spinal manipulation.

DISCUSSION

This article describes the history of Chinese spinal manipulation as revealed through past formal textbook publications on this topic, along with journal articles describing both the basic science foundation and clinical applications of such manipulation. In addition, the current status of Chinese spinal manipulation is described.

CONCLUSION

There is a long history of the use of spinal manipulation throughout China, though some basic problems of application remain. Current research may help to resolve these problems.

New imidazoles as probes of the active site topology and potent inhibitors of beta-glucosidase

Series of 4-arylimidazoles, omega-N-acylhistamines and 4-(omega-phenylalkyl)imidazoles were synthesized in order to probe the active site topology of sweet almond beta-glucosidase. These imidazole derivatives were shown to be very powerful competitive inhibitors. Among the 20 tested compounds, omega-N-benzoylhistamine and 4-(3'-phenylpropyl)imidazole are the most potent inhibitors of the enzyme, with pH-independent Ki values of 0.06 and 0.07 microM, respectively. The inhibition of 4-(omega-phenylalkyl)imidazoles exhibited an interesting trend as to Ki values: 4-phenylimidazole (6.6 microM)>4-benzylimidazole (1.4 microM)>4-(2'-phenylethyl)imidazole (0.82 microM)>4-(3'-phenylpropyl)imidazole (0.07 microM)<4-(4'-phenylbutyl)imidazole (0.13 microM)<4-(5'-phenylpentyl)imidazole (0.3 microM). This revealed that the imidazole and aryl binding sites (which result from favorable interactions within the corresponding glycone and aglycone binding subsites) are separated by the optimal distance equivalent to the length of a -CH2-CH2-CH2- group. Substitutions of the phenyl moieties of 4-phenylimidazole and 4-benzoylhistamine result in weaker inhibition. These classes of imidazoles are particularly powerful inhibitors of sweet almond beta-glucosidase.

The effect of cervical traction combined with rotatory manipulation on cervical nucleus pulposus pressures

OBJECTIVE

To study experimentally the effect of cervical traction combined with rotatory manipulation on the pressure of the cervical nucleus pulposus.

DESIGN

Randomized experimental study.

SETTING

Institute of Clinical Anatomy and Biomechanics, the First Military Medical University, GuangZhou, China.

SUBJECTS

Twelve fresh cervical spines, from C7 to occipital bone, were obtained from cadavers of patients who had died from acute brain death.

INTERVENTION

State A: under different traction forces, the cervical spine was rotated. State B: the cervical spine was rotated first and then tractioned. State C: the cervical spine was tractioned and rotated simultaneously.

MAIN OUTCOME MEASURES

The cervical spine was tractioned and rotated by the Material Test System (MTS), and pressures of the cervical nucleus pulposus of C3-4, C4-5 and C5-6 were measured using pressure sensors.

RESULTS

(a) When the traction force increased, the pressure fell continuously in the 200-N tractioned spines; the pressure increased slightly when the sample was rotated. (b) The pressure fell to a certain extent when the state of cervical spine was restored. (c) In state A, the pressure fell obviously and increased slightly under a 200-N traction force and then the sample was rotated; in state B, the pressure first increased to a certain extent and then fell slightly and in state C, the pressure underwent no change in the main.

CONCLUSIONS

The results of this research suggest that rotatory manipulation of cervical spine under traction was the safest of the three procedures and the traction force used in clinical treatment may be a little smaller.

[The epidemiologic value of polymerase chain reaction to the diagnosis of brucellosis patients]

PCR was used to test fifty-four brucellasis patients and thirty-six healthy people as controls, who were all from Man Tang Chuan and Yi He communities, Sui De county, Shan Xi Province, where brucellosis out-break was occurred in 1996. The diagnostic titres of SAT for brucellasis patients was set 1:100++. The positive rates of PCR in patients and controls were 75% and 65.7% respectively, comparing with the positive rates of RBPT 96.3% and 30.6% in the same two groups. At the same time, we also detected eight people who had received immunization one month to thirty-two years ago, with positive rates for PCR and RBPT 100% and 87.5% respectively. The results showed that there was no significant diversity of PCR results among acute, subacute and chronic brucellosis patients. It was revealed that the serological results were related to the course of disease, but the results came out of PCR method which was used to detect target DNA was not influenced by the course of disease.

[Clinical studies on liangxue piyan granule no. 2 in treating psoriasis]

OBJECTIVE

To observe the effect of Liangxue Piyan granule No. 2 (LPG) on psoriasis.

METHODS

Ninety-six cases of psoriasis patients were treated with LPG and a control group of 32 cases was set up, which was treated with Fufang Qingdai Capsule (FQC).

RESULTS

The total effective rate of LPG was 84.7%, that of the control group was 71.9% (P > 0.05), there was no significant difference between two drugs in treatment of psoriasis. The recurrent rate of LPG group (3.6%) was lower than that of control (21.7%), P < 0.01.

CONCLUSION

This granule provides a better drug for treatment of psoriasis.

Ultraviolet spectroscopic evidence for decreased motion of the active site tyrosine residue of delta 5-3-ketosteroid isomerase by steroid binding

delta 5-3-Ketosteroid isomerase (EC 5.3.3.1) from Pseudomonas testosteroni catalyzes the highly efficient conversion of delta 5-3-ketosteroids to delta 4-3-ketosteroids by a stereoselective and intramolecular transfer of the 4 beta-proton to the 6 beta-position. Tyr-14 is the critical general acid and Asp-38 is the general base involved in catalysis. The UV absorption bandwidths of Tyr-14 were much narrower than those of the other two tyrosines (Tyr-55 and Tyr-88) of isomerase or of the N-acetyltyrosine ethyl ester in aqueous solution, suggesting that Tyr-14 is restricted in its mobility. Further immobilization of this residue occurs upon steroid binding. Thus, 5 alpha-estrane-3,17-dione, an A-ring saturated steroid, induces significant narrowing of the tyrosine absorption bands (pi-->pi*) of the main peak (279.5 nm) and the shoulder (285.5 nm) of Tyr-14, with no significant changes in lambda max. No effects of steroid binding were found on the absorption bandwidths of Tyr-55, Tyr-88, or the phenylalanine residues. The ratio of the absorbance (Amax) at the absorption maximum (lambda max) to that at lambda max plus 4 nm (Amax +4) was used as a measure of peak sharpness. Specifically, the ratios of A279.5/A283.5 (main peak) and A285.5/A289.5 (shoulder) of Tyr-14 of the free enzyme at 25 degrees C were 1.25 and 1.89, respectively, and they increased to 1.41 and 2.70, respectively, in the complex. A more precise measurement of the band narrowing from 4.2 to 3.1 nm between the inflection points was obtained from the derivative spectra. The absorption bands of free and steroid-bound isomerase were narrowed significantly by lowering the temperature and were broadened by denaturation, suggesting that the unusual peak-sharpening effects induced by steroid binding arise from the restricted motion of Tyr-14, as well as from more directional hydrogen bonding resulting from the displacement of water molecules from the active site and decreased flexibility of the protein. Larger enthalpy of the sharpening effects was observed for the steroid-bound enzyme (-0.527 +/- 0.016 kcal/mol) than for the free enzyme (-0.250 +/- 0.018 kcal/mol) by lowering the temperature, indicating that interactions of Tyr-14 with its environment, which restrain its motion, are stronger in the steroid-bound enzyme than in the free enzyme. Hydrogen-bonding modes of Tyr-14, mobility of the active site, and protein flexibility are the environmental factors determining the absorption bandwidths of the critical Tyr-14 residue.

[The morphological changes in trabecular architecture of bone in severe primary hyperparathyroidism]

By histomorphometry bone biopsy specimens were evaluated from 10 patients with severe primary hyperparathyroidism (PHPT). The data suggest that the mean trabecular width and trabecular bone volume were slightly, but not significantly increased. As indices of bone remodeling activity, both trabecular osteoid surface and trabecular resorption surface were significantly increased indeed, indicating high bone turn-over occurred in PHPT. The dynamic study showed that much more trabecular bone surface was covered either with single or double tetracycline labels in PHPT than in control. The overproduction of osteoid in the patients leads to the accumulation of osteoid on the trabecular surface. Moreover, the mean osteoid width seemed to be thicker in PHPT than in control, suggesting the co-existence of osteomalacia, which might be a possible explanation for eucalcemia usually seen in the majority. Part of chinese PHPT patients.

[Trabecular connectivity in primary hyperparathyroidism]

By bone histomorphometry, 10 cases of primary hyperparathyroidism (PHPT) were used to study the trabecular connectivity, which in a few literatures was mentioned to be reserved somehow. Our data suggest that in comparison with the normal control (10 subjects) the nodes (N.Nd), the number of terminus (N.Tm), the total strut length (TSL), the length between the nodes (Nd.Nd), trabecular separation (Tb.Sp) and trabecular thickness (Tb.Th) were significantly increased while no significance was found in N.Nd/N.Tm, Tm.Tm and TBV. The correlation analyses indicate that there is no correlation between the variables in the normal controls. In contrast, however, TBV and Tb.Th showed negative correlations with N.Tm and Tm.Tm. Besides these, there were positive correlations between N.Nd/N.Tm and TBV or Tb.Th, and a negative correlation between N.Nd/N.Tm and Tb.Sp. The results suggest that to certain degree the trabecular connectivity in PHPT be destructed while the three dimensional architecture be reserved. Our data seem to be different from those reported previously. It may be due to the severity of PHPT in our patients.

Characterization of the three tyrosine residues of delta 5-3-ketosteroid isomerase by time-resolved fluorescence and circular dichroism

delta 5-3-Ketosteroid isomerase (EC 5.3.3.1) of Pseudomonas testosteroni converts delta 5-3-ketosteroids to delta 4-3-ketosteroids via an enolic intermediate. Site-specific mutagenesis has identified Tyr-14 and Asp-38 as the catalytically essential general acid and base, respectively. Three tyrosine residues (Tyr-14, Tyr-55, and Tyr-88) are the only significant fluorophores in the wild-type isomerase. Recent studies of the steady-state fluorescence of the wild-type enzyme and all six mutant enzymes in which one or two tyrosine residues have been mutated to phenylalanine show that the fluorescence intensity of Tyr-14 is very high, that of Tyr-88 is very low, and that of Tyr-55 is intermediate and comparable to that of N-acetyltyrosine amide in solution (Li, Y.-K., Kuliopulos, A., Mildvan, A.S., & Talalay, P. (1993) Biochemistry 32, 1816-1824). Extension of these experiments by time-resolved fluorescence and fluorescence anisotropy measurements demonstrates that Tyr-14, which is in a hydrophobic environment, has an unusually long fluorescence lifetime (4.6 ns) as compared to Tyr-55 (2.0 ns) or Tyr-88 (0.8 ns) and to most protein tyrosine residues (0.2-2 ns). The Förster distances obtained from the absorption and emission of these tyrosines predict that total quenching of Tyr-14 fluorescence by Tyr-55, and to a lesser degree by Tyr-88, would occur if their orientations were favorable.(ABSTRACT TRUNCATED AT 250 WORDS)