760 Investigating Theatre Cancellation Rates in a London Hospital

Aim

Theatre cancellations are a major source of system inefficiency, placing an unnecessary financial burden on the NHS. The aim of this audit was to investigate the reasons for cancellations in elective surgery at a London hospital and to assess the general preoperative process.

Method

We undertook a retrospective audit of all elective theatre cancellations from the day surgery unit over a three-month period in 2021. 78 cancellations were identified, and their cause was investigated. Furthermore, we reviewed theatre lists over one month to calculate the proportion of cancelled procedures per specialty. Also, to gain a further understanding of the present protocol, we reviewed the current preoperative process.

Results

The main reason for cancellations was patients being physiologically unfit for surgery, accounting for 28.2% of all cases. The next biggest reason for cancellation, at 16.7%, was failure to comply with COVID protocol. The specialty with the largest proportion of cancellations was General Surgery, at 17.7%.

Conclusions

We believe many reasons for cancellations were avoidable. Therefore, we propose a change to the preoperative process to target multiple reasons for cancellation. We suggest a more comprehensive pre-admission phone call five days prior to surgery which includes discussions around medication compliance and changes in condition. We also suggest a set of observations and routine bloods are taken when patients come in for their COVID swab. This allows any potential cause of cancellation to be identified and rectified, or the patient could be rescheduled. This should increase efficiency of the day surgery unit.

POS0592 PREDICTING LIVER ENZYME ELEVATION IN PATIENTS WITH RHEUMATOID ARTHRITIS ON TREATMENT WITH METHOTREXATE USING SUPERVISED MACHINE LEARNING

Background

Methotrexate (MTX) is the most used disease-modifying anti-rheumatic drug (DMARD) in the treatment of rheumatoid arthritis (RA). (1) Chronic use of this medication warrants close laboratory monitoring given its propensity for liver damage and myelosuppression. (2) MTX associated hepatic dysfunction is a well-described adverse effect and has been seen in up to a quarter of patients on long term treatment. (3)

Recent advances in health care coupled with the extensive use of electronic health records (EHR) has resulted in the accumulation of large amounts of patient data. Approaches like machine learning (ML) allows us to leverage these large data sets to predict outcomes and support clinical decision making. (4) We hypothesized that a ML model trained on conventionally available EHR data would be able to identify patients at the greatest risk of developing MTX related hepatotoxicity.

Objectives

To develop a machine learning model to accurately predict liver enzyme elevation in rheumatoid arthritis (RA) patients on treatment with methotrexate (MTX) using electronic health record (EHR) data from a real-world RA cohort.

Methods

Demographic, clinical, biochemical, as well as prescription information from 569 RA patients were retrospectively collected. Liver transaminase elevation above the upper limit of normal following initiation of MTX, was the primary outcome. The total dataset was randomly split into a training (80%) and test set (20%) and used to develop a Random Forest Classifier model. The best model was selected after hyper-parameter tuning and fivefold cross-validation.

Results

104 patients (18.2%) developed hepatic dysfunction while on MTX therapy. The best performing predictive model had an accuracy/F1 score of 0.87. The top ten predictive features were then used to create a limited feature model that retained most of the predictive accuracy, with an accuracy/F1 score of 0.86.

Conclusion

Our proof-of-concept study suggests the possibility of building a well-performing ML model to predict liver enzyme elevation in RA patients being treated with MTX. Similar ML models could be used to identify ‘high risk’ patients who can then be potentially targeted for closer monitoring with the aim of preventing these adverse outcomes. Conversely, patients at low risk can avoid extra outpatient visits, thereby reducing costs.

References

[1]OEwierkot J, Szechiñski J. Methotrexate in rheumatoid arthritis. Pharmacological reports Citeseer; 2006;58:473-92.

[2]Whittle S, Hughes R. Folate supplementation and methotrexate treatment in rheumatoid arthritis: a review. Rheumatology Oxford University Press; 2004;43:267-71.

[3]Mori S, Arima N, Ito M, Ueki Y, Abe Y, Aoyagi K, et al. Incidence, predictive factors, and severity of methotrexate-related liver injury in rheumatoid arthritis: A longitudinal cohort study. Rheumatology Advances in Practice 2020;

[4]Panch T, Szolovits P, Atun R. Artificial intelligence, machine learning and health systems. Journal of global health International Society for Global Health; 2018;8.

Disclosure of Interests

None declared.

The influence of α-coordinating groups of aldehydes on E/Z-selectivity and the use of quaternary ammonium counter ions for enhanced E-selectivity in the Julia-Kocienski reaction

Modified reaction conditions for improved E-selectivity of olefins in the Julia-Kocienski reaction of aldehydes having α-coordinating substituents are demonstrated. The chelating groups in aldehydes are expected to stabilize the syn-transition state with metal ions, whereas the weakly coordinating quaternary ammonium ions are devoid of all possible chelating interactions to enhance E-selectivity. A systematic investigation is presented to study the size of the neighbouring protecting groups of aldehydes and their chelation effect on E/Z-selectivity in the Julia-Kocienski reaction.

Building resilient and responsive research collaborations to tackle antimicrobial resistance-Lessons learnt from India, South Africa, and UK

Research, collaboration, and knowledge exchange are critical to global efforts to tackle antimicrobial resistance (AMR). Different healthcare economies are faced with different challenges in implementing effective strategies to address AMR. Building effective capacity for research to inform AMR-related strategies and policies is recognised as an important contributor to success. Interdisciplinary, intersector, as well as international collaborations are needed to span global to local efforts to tackle AMR. The development of reciprocal, long-term partnerships between collaborators in high-income and in low- and middle-income countries (LMICs) needs to be built on principles of capacity building. Using case studies spanning local and international research collaborations to codesign, implement, and evaluate strategies to tackle AMR, we have evaluated and build upon the ESSENCE criteria for capacity building in LMICs. The first case study describes the local codesign and implementation of antimicrobial stewardship (AMS) in the state of Kerala in India. The second case study describes an international research collaboration investigating AMR surgical patient pathways in India, the UK, and South Africa. We describe the steps undertaken to develop robust, agile, and flexible AMS research and implementation teams. Notably, investing in capacity building ensured that the programmes described in these case studies were sustained through the current severe acute respiratory syndrome coronavirus pandemic. Describing the strategies adopted by a local and an international collaboration to tackle AMR, we provide a model for capacity building in LMICs that can support sustainable and agile AMS programmes.

SAT0538 CLINICAL PROFILE OF AUTOIMMUNE UVEITIS NOT ASSOCIATED WITH HLA B27: A RETROSPECTIVE SINGLE CENTER STUDY

Background:

Autoimmune uveitis is frequently referred to a rheumatologist for evaluation & treatment. While clinical characteristics of HLA B27 associated uveitis are well documented, scanty information is available on non HLA-B27 associated autoimmune uveitis. We have described the clinical characteristics of our patients of non-B27 uveitis and compare the same with patients of Asian Indian HLAB27 uveitis.

Objectives:

To describe and compare the clinical characteristics of non HLA-B27 associated autoimmune uveitis.

Methods:

Retrospective review of records from hospital’s electronic medical record database and included all cases of autoimmune uveitis that were referred to rheumatology from January 2017 and December 2018. Among these, those who did not have HLA B tissue typing record or were HLAB27 positive; were excluded. Pertinent details like age, sex, no. of episodes, unilateral or bilateral, location of uveitis (anterior, posterior or pan uveitis, association of synechiae & vasculitis), baseline CRP & ESR levels along with the HLA B profile(SSP-PCR) & nature of treatment received (systemic steroids, DMARD initiation) were collected. For comparison, clinical features of a HLA B27+ve uveitis series from the same ethnic Asian-Indian population were used1. Subgroup analysis was also done between the common non B27 HLA genotypes. Descriptive statistics were summarized using mean & percentage. Chi square & Fischer’s test was used to compare the groups and subgroups.

Results:

Out of total 210 patients screened, 17 cases were HLA B27 negative on HLA B tissue typing. The key demographic and clinical features of our patients of autoimmune uveitis not associated with HLA B27 in comparison with the B27 +ve uveitis group are given in table 1.

Table 1

Comparison of clinical features of our patients versus B27 +ve uveitis

Non HLA B27 Autoimmune Uveitis (N=17)Ninan et al (N=25)P valueAge (years) at disease onset 16-35 415 More than 3513 70.009 Onset not known 0 3Sex Male 6210.002 Female11 4Region of uveitis anterior 9240.001 posterior & pan-uveitis 8 1Biochemical parameters CRP (mg/L)6.45 + 8.39N.A- ESR (mm/hr)24.75 + 18.80N.AAssociated complications synechiae formation4 of 174 of 250.69 retinal vasculitis4 of 170 of 17-

Recurrent uveitis was seen in 11 out of 17 patients in our patients as compared to 15 out of 22 (p 0.81) in HLA B27 +ve patients.

HLA B7 and HLA B35 were the most frequent genotypes (figure 1). Sub group analysis showed that 87.5% of patients with a component of posterior uveitis were HLA B7 or HLA B35 positive. It was noted none of 5 cases of HLA B35 +ve uveitis needed second line DMARD initiation after a tapering course of systemic steroids. There was no other significant difference in the clinical or treatment parameters noted in the subgroup analysis between the HLA genotypes.

Conclusion:

Autoimmune uveitis not associated with HLA B27 tends to have older age of onset, female predominance, more common involvement of posterior uvea and association of vasculitis than HLAB27 autoimmune uveitis. Among non HLA B27 uveitis, HLA B07 and HLA B35 are the most common serotypes in our Asian south Indian group. Therapeutic stratification for a delayed initiation of second line DMARD therapy needs to be studied further particularly in HLA B35 +ve uveitis.

References:

[1]Ninan F, Mathew J, Philip SS, John D, Danda D, John SS. Uveitis of spondyloarthritis in Indian subcontinent: a cross sectional study. Int J Adv Med 2017;4:1441-6

Disclosure of Interests:

None declared

A nutrigenetic approach for investigating the relationship between vitamin B12 status and metabolic traits in Indonesian women

PURPOSE

Adverse effects of maternal vitamin B12 deficiency have been linked to major clinical outcomes, including increased body mass index and gestational diabetes, however, less is known about vitamin B12 nutrition in non-pregnant women. Hence, the aim of the present study was to explore the relationships between metabolic traits and vitamin B12 status in a cohort of healthy Indonesian women and to investigate whether these relationships were modified by dietary intake using a genetic approach.

METHODS

A total of 117 Minangkabau women (aged 25-60 years), from the city of Padang, West Sumatra underwent anthropometric, biochemical, dietary intake analysis and genetic tests. Genetic risk scores (GRS) based on nine vitamin B12 associated single nucleotide polymorphisms (SNPs) (B12-GRS) and nine metabolic SNPs (metabolic-GRS) were constructed.

RESULTS

The B12-GRS and metabolic-GRS had no effect on vitamin B12 (P > 0.160) and metabolic traits (P > 0.085). However, an interaction was observed between the B12-GRS and dietary fibre intake (g) on glycated haemoglobin (HbA1C) levels (P interaction = 0.042), where among those who consumed a low fibre diet (4.90 ± 1.00 g/day), individuals carrying ≥9 risk alleles for vitamin B12 deficiency had significantly higher HbA1C levels (P = 0.025) compared to those carrying ≤8 risk alleles.

CONCLUSION

Our study showed a significant impact of the B12-GRS on HbA1C concentrations through the influence of a dietary factor, however, our study failed to provide evidence for an impact of metabolic-GRS on lowering B12 concentrations. Further replication studies utilizing larger sample sizes are needed to confirm our findings.

A Review of Recent Advances in Nanoengineered Polymer Composites

This review paper initially summarizes the latest developments in impact testing on polymer matrix composites collating the various analytical, numerical, and experimental studies performed since the year 2000. Subsequently, the scientific literature investigating nanofiller reinforced polymer composite matrices as well as self-healing polymer matrix composites by incorporating core-shell nanofibers is reviewed in-depth to provide a perspective on some novel advances in nanotechnology that have led to composite developments. Through this review, researchers can gain a representative idea of the state of the art in nanotechnology for polymer matrix composite engineering, providing a platform for further study of this increasingly industrially significant material, and to address the challenges in developing the next generation of advanced, high-performance materials.

An update on vitamin B12-related gene polymorphisms and B12 status

Background

Vitamin B12 is an essential micronutrient in humans needed for health maintenance. Deficiency of vitamin B12 has been linked to dietary, environmental and genetic factors. Evidence for the genetic basis of vitamin B12 status is poorly understood. However, advancements in genomic techniques have increased the knowledge-base of the genetics of vitamin B12 status. Based on the candidate gene and genome-wide association (GWA) studies, associations between genetic loci in several genes involved in vitamin B12 metabolism have been identified.

Objective

The objective of this literature review was to identify and discuss reports of associations between single-nucleotide polymorphisms (SNPs) in vitamin B12 pathway genes and their influence on the circulating levels of vitamin B12.

Methods

Relevant articles were obtained through a literature search on PubMed through to May 2017. An article was included if it examined an association of a SNP with serum or plasma vitamin B12 concentration. Beta coefficients and odds ratios were used to describe the strength of an association, and a P < 0.05 was considered as statistically significant. Two reviewers independently evaluated the eligibility for the inclusion criteria and extracted the data.

Results

From 23 studies which fulfilled the selection criteria, 16 studies identified SNPs that showed statistically significant associations with vitamin B12 concentrations. Fifty-nine vitamin B12-related gene polymorphisms associated with vitamin B12 status were identified in total, from the following populations: African American, Brazilian, Canadian, Chinese, Danish, English, European ancestry, Icelandic, Indian, Italian, Latino, Northern Irish, Portuguese and residents of the USA.

Conclusion

Overall, the data analyzed suggests that ethnic-specific associations are involved in the genetic determination of vitamin B12 concentrations. However, despite recent success in genetic studies, the majority of identified genes that could explain variation in vitamin B12 concentrations were from Caucasian populations. Further research utilizing larger sample sizes of non-Caucasian populations is necessary in order to better understand these ethnic-specific associations.

Abstract P1-08-10: Introduction of H1047R oncogenic mutation of PI3K p110alpha subunit in HER2-overexpressing mammary epithelial cells confers a "stem-like" phenotype and acute sensitivity to HSP90 inhibition

The Human Epidermal Growth Factor Receptor 2 (HER2) oncogene is amplified in one-fifth of breast cancers (BC). However, development of resistance against standard anti-HER2 therapies poses a major clinical challenge. Anti-tumor efficacy of HER2-targeting agents depends on inhibition of the downstream phosphatidylinositol-3 kinase (PI3K) signaling cascade. Gain-of-function somatic mutations in the gene encoding the PI3K catalytic subunit p110alpha (PIK3CA), co-expressed in about 40% of HER2+ BC, have been implicated in conferring resistance to HER2 monoclonal antibody herceptin. The single amino acid alteration H1047R within the kinase domain of PIK3CA is one of three hot spot mutations prevalent in BC.

Previously, we demonstrated that introduction of H1047R mutation in HER2-overexpressing MCF10A mammary epithelial cells enhances cellular transformation and decreases herceptin sensitivity by inducing secretion of endogenous ErbB ligand heregulin. However, genetic ablation of HER3, the major co-receptor for HER2 and the solitary receptor for heregulin, was insufficient for complete inhibition of cell growth, indicating the existence of additional mechanism/s responsible for the heightened aggressiveness and decreased drug sensitivity of HER2/H1047RPI3K cells. In the current study, we looked further into the molecular changes within these cells that might be responsible for these phenomena.

When compared with the HER2/WTPI3K cells, the HER2/H1047RPI3K cells revealed a significant increase in CD44high/CD24low/negative populations, common markers of BC stem cells, as well as molecular and phenotypic changes associated with epithelial-to-mesenchymal transition. These observations are in agreement with previously published report on mouse model of HER2/H1047RPI3K BC. Further analyses demonstrated additional stem cell-associated characteristics in HER2/H1047RPI3K cells, such as expression of angiogenic and inflammatory cytokines, ability to induce chemotaxis and invasion, activation of TGFb and NFKb signaling pathways. Connectivity map (CMap) analysis of the gene expression signatures from HER2/H1047RPI3K cells revealed a negative association with those from BC cells treated with 17AAG, an inhibitor of the heat shock protein 90 (HSP90). In line with this, HER2/H1047RPI3K-expressing cells are found to be more sensitive to HSP90 inhibition compared to the pan-ErbB inhibitor lapatinib.

Cancer stem cells are implicated in drug resistance and tumor recurrence. Enrichment of cell population expressing high levels of stem cell markers and stem cell-related features could be one of major mechanisms by which BC cells co-expressing HER2 and H1047RPI3K adapt to anti-HER2 therapeutic agents. Acute dependence on molecular chaperone HSP90 provides a unique, yet practical opportunity to effectively inhibit tumors harboring both molecular alterations, since HSP90 inhibitors have already shown encouraging clinical activity in herceptin-resistant setting.

Citation Format: Surendran S, Bhola N, Arteaga CL, Chakraborty K, Chakrabarty A. Introduction of H1047R oncogenic mutation of PI3K p110alpha subunit in HER2-overexpressing mammary epithelial cells confers a "stem-like" phenotype and acute sensitivity to HSP90 inhibition [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-08-10.

Abnormal Expression of Genes Associated with Development and Inflammation in the Heart of Mouse Maternal Phenylketonuria Offspring

This study descibes gene expression in the fetus hearts obtained from mouse model for Phenylketonuria. These hearts have cardiovascular disease (CVD). Therefore genes involved in CVD were examined. Several genes associated with heart development and inflammation were found to be altered. In order to investigate whether the abnormal gene expression alters transcription and translation, the levels of troponin mRNA and protein were determined. One step real time RT-PCR showed a reduction in cardiac troponin I, troponin T2 and ryanodine receptor 2. Determination of troponin I and T protein levels showed reduced levels of these proteins. Our results suggest that altered gene expression affects protein production. These changes are likely involved in the cardiovascular defects seen in the mouse.

Studies on the electrochemical intercalation/de-intercalation mechanism of NiMn2O4 for high stable pseudocapacitor electrodes

Sub-micron sized polyhedral shaped NiMn₂O₄ particles were successfully prepared by a glycine assisted solution combustion method.

Effect of pH on the sonochemical synthesis of BiPO4 nanostructures and its electrochemical properties for pseudocapacitors

Using sonochemical method, BiPO4 nanocrystals were prepared at different pH conditions (pH-1, 3, 5, 7, 9 & 12) for the possible applications of pseudocapacitor electrodes. The prepared BiPO4 nanocrystals belong to monoclinic structure with P21 space group. The SEM image revealed that the particles changed from irregular coarse shape into rod like structure (pH-1 to 7) which finally collapsed into irregular aggregates (pH-9 to pH-12). The observed spot patterns from SAED inferred the polycrystalline nature of the material. The electrochemical performance of the synthesized BiPO4 in various ultrasound irradiation conditions such as irradiation time (30min, 1h, 2h and 3h) and ultrasonication power (40%, 50%, 60% and 70% of instrumental power) was studied. A maximum specific capacitance of 1052F/g (pH-7 at 2mV/s) was observed for the BiPO4 prepared in the ultrasonication reaction condition of 2h with 60% power. Also the obtained specific capacitance was high compared with the conventional precipitation method (623F/g at 2mV/s) that revealed the prominence of sonication method. Similarly, BiPO4 prepared at pH-7 delivered a maximum specific capacitance of 302F/g at 2mA/cm(2) calculated from galvanostatic charge-discharge (GCD) method than the other pH conditions. However, the cycling stability of BiPO4 (pH-7) was not appreciable even for 200 cycles. So, attempts were taken to enhance the cycling stability of the material by employing various carbon matrices such as acetylene black, activated carbon and MWCNT instead of carbon black during electrode preparation. BiPO4 material with activated carbon delivered good capacitance retention compared with other carbon matrices. This enhanced electrochemical performance of BiPO4 (pH-7) using activated carbon matrix inferred that it could be utilized as efficient negative electrode material for pseudocapacitors.

In vitro and in vivo hepatoprotective activity of Cissampelos pareira against carbon-tetrachloride induced hepatic damage

Administration of hydroalcoholic extract of Cissampelos pareira roots (CPRE) and standard drug silymarin in rats showed significant hepatoprotective action against CCl4 induced hepatotoxicity. Elevated serum marker enzymes of AST, ALT, ALP and serum bilirubin were significantly reduced to near normal level in CPRE treated rats. Lipid peroxidation level was decreased significantly in CPRE 100, 200, 400 mg/kg doses treatment groups. In case of antioxidant enzymes SOD, catalase levels were increased significantly after CPRE 200, 400 mg/kg doses, similarly it increased the enzyme levels of GST, GPx, and GSH. CPRE 200, 400 mg/kg decreased cholesterol level, and increased triglyceride level. In vitro hepatoprotective activity of the extract was evaluated at 20, 40, 60, 80 and 100 microg/ml concentration against CCl4 (1%) induced toxicity in freshly isolated rat hepatocytes. HepG2 cells showed significant dose dependent increase in percentage viability at the doses 20, 40, 60, 80 and 100 microg/ml of CPRE compared to CCl4 exposed HepG2 cells. Results of this study strongly demonstrate Cissampelos pariera having good hepatoprotective potential.

Gastroprotective activity of Cinnamomum tamala leaves on experimental gastric ulcers in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Cinnamomum tamala T. Nees & Eberm (Family Lauraceae) is used traditionally in Indian System of Medicine as carminative, anthelmintic, diuretic, and used in colic, dyspepsia, and diarrhea.

AIM OF THE STUDY

This study was aimed to evaluate the gastroprotective effects of Cinnamomum tamala leaves.

METHODS

Cinnamomum tamala leaves extract (CTE; 50,100 and 200mg/kg body weight) was administered orally, twice daily for 5 days for prevention from ethanol (EtOH)-, cold-restraint stress (CRS)- and pylorus ligation (PL)-induced ulcers. Estimation of H(+)K(+)ATPase activity and gastric wall mucous were performed in EtOH-induced ulcer model, antioxidant enzyme activities was carried out in CRS-induced ulcer model, and various gastric secretion parameters like volume of gastric juice, acid output, and pH value were estimated in PL-induced ulcer model.

RESULTS

A significant reduction in lesion index was observed in ulcer-induced animals treated with CTE at different doses when compared with ulcerated rats in all models. A significant decrease occurred in the level of H(+)K(+)ATPase, volume of gastric juice, and acid output. Simultaneously the level of gastric wall mucus and pH were increased significantly. These showed dose-dependent action of CTE. The antioxidant enzyme levels of LPO and SOD were decreased while administering CTE at different doses, compared with their control values. Contrary to this the level of CAT enzyme showed significant increase.

CONCLUSIONS

The results of our study showed that Cinnamomum tamala possess significant gastroprotective activity, probably due to its free radical scavenging activity.

Rare anatomical variant: arterial circle in palm and at the base of the thumb

In this article, we describe anomalous formation, distribution of superficial palmar arch and an arterial circle at the base of the thumb found during routine dissection classes in the right hand of a 45-year-old male cadaver. These variations are unique and provide significant information to surgeons dissecting the hand region.

The branching pattern and communications of the musculocutaneous nerve

Anatomical variations of peripheral nerves are important and can help explain otherwise incomprehensible clinical findings. A study of 26 right and 18 left formalin-preserved upper limbs identified the fact that the musculocutaneous nerve is subject to considerable anatomical variation, including communication with the median nerve. A study of its branching pattern made us aware of why debility after trauma to the lateral aspect of the upper arm may be more than expected, and this study considers the clinical and surgical importance of these variations of the musculocutaneous nerve.

Circulus arteriosus cerebri: a study of variation in the fetal and adult human brains of south Indians

The Circle of Willis or Circulus Arteriosus Cerebri and its branches are subject to many variations. The Circle of Willis with a classical description is very rare. The constituent arteries forming the circle vary greatly in size in different individuals and on two sides in the same subject. Study by dissection or by angiographic methods by several workers has shown that deviations from the normal pattern occur in a very high proportion of cases. There are differing views regarding the variations in the circle. Thus, this study was done to compare our findings with the others. In the present study, each artery taking part in the circle has been described in relation to the length, size and its origin separately and the findings have been compared.

Anti-apoptotic Bcl-2 gene transfection of human articular chondrocytes protects against nitric oxide-induced apoptosis

We stably transfected early passage chondrocytes with an anti-apoptotic Bcl-2 gene in vitro using a retrovirus vector. Samples of articular cartilage were obtained from 11 patients with a mean age of 69 years (61 to 75) who were undergoing total knee replacement for osteoarthritis. The Bcl-2-gene-transfected chondrocytes were compared with non-transfected and lac-Z-gene-transfected chondrocytes, both of which were used as controls. All three groups of cultured chondrocytes were incubated with nitric oxide (NO) for ten days. Using the Trypan Blue exclusion assay, an enzyme-linked immunosorbent assay and flow cytometric analysis, we found that the number of apoptotic chondrocytes was significantly higher in the non-transfected and lac-Z-transfected groups than in the Bcl-2-transfected group (p < 0.05). The Bcl-2-transfected chondrocytes were protected from NO-induced impairment of proteoglycan synthesis.

We conclude that NO-induced chondrocyte death involves a mechanism which appears to be subject to regulation by an anti-apoptotic Bcl-2 gene. Therefore, Bcl-2 gene therapy may prove to be of therapeutic value in protecting human articular chondrocytes.

Ultrafast far-infrared dynamics probed by terahertz pulses: A frequency domain approach. I. Model systems

Time-resolved terahertz spectroscopy has become a widely used experimental tool for the investigation of ultrafast dynamics of polar systems in the far infrared. We have recently proposed an analytical method for the extraction of a transient two-dimensional susceptibility from the experimental data [Nĕmec, Kadlec, and Kuzel, J. Chem. Phys. 117, 8454 (2002)]. In the present paper the methodology of optical pump-terahertz probe experiments is further developed for direct application in realistic experimental situations. The expected two-dimensional transient response function is calculated for a number of model cases (including Drude dynamics of free carriers, harmonic and anharmonic oscillator modes); these results serve as a basis for the interpretation of experimental results. We discuss also the cases where only partial (one-dimensional) information about the system dynamics can be experimentally obtained.

Mental retardation and hypotonia seen in the knock out mouse for Canavan disease is not due to succinate semialdehyde dehydrogenase deficiency

Canavan disease (CD) is an autosomal recessive disorder caused by aspartoacylase deficiency leading to accumulation of N-acetylaspartic acid and spongy degeneration of the brain. The mouse model for CD showed low levels of glutamate and gamma-aminobutyric acid (GABA) in the brain. Whether the low levels of glutamate and GABA observed in the CD mouse brain lead to abnormal production of glutamate-GABA associated enzymes and resulting succinate production is not obvious. While glutamate dehydrogenase and alpha-ketoglutarate dehydrogenase complex activities are lower in the cerebellum and brain stem of the CD mouse, alanine aminotransferase and succinate semialdehyde dehydrogenase (SSADH) activities and succinate level are similar to the levels observed in the wild type. Deficiency of SSADH has been suggested to be associated with mental retardation and hypotonia, similar to the clinical features of CD. The normal SSADH activity in the CD mouse brain suggests that mental retardation and hypotonia seen in the CD mouse is not due to SSADH activity and if documented also in patients with CD.

Closed reduction of colles fractures: comparison of manual manipulation and finger-trap traction: a prospective, randomized study

BACKGROUND

An optimal outcome of closed treatment of a Colles fracture may depend on accurate reduction and adequate immobilization. It has been suggested that the use of finger-trap traction results in a better reduction and a lower rate of redisplacement than manual manipulation does, but to our knowledge these concepts have never been evaluated scientifically. We compared these two methods in a prospective, randomized controlled trial.

METHODS

Two hundred and twenty-three patients with 225 displaced Colles-type fractures were randomized to treatment with closed reduction with either finger-trap traction (112 patients) or manual manipulation (111 patients). The fractures were assessed radiographically by measurement of the radial angle, dorsal tilt, and radial shortening before reduction, immediately after reduction, and at one and five weeks after reduction.

RESULTS

The groups were comparable with regard to age, sex, side of injury, fracture grade, and amount of displacement at presentation. No significant differences were found between the alignment of the fractures in the two treatment groups at any time. With dorsal tilt of <10 degrees and radial shortening of <5 mm considered acceptable, the two techniques both produced an 87% rate of satisfactory reductions. However, the percentages of fractures in an acceptable alignment were only 57% and 50% at one week after finger-trap traction and manual manipulation, respectively, and only 27% and 32% at five weeks. The failure rates did not differ significantly between the two groups.

CONCLUSIONS

The two methods of fracture reduction did not differ with regard to the eventual position of the fracture or the rate of failure. Although closed reduction was successful for the majority of fractures, most redisplaced substantially during the period of cast immobilization.

Possible role of prostaglandin E2 in human amniotic epithelial cell death: an in vitro study

OBJECTIVE AND DESIGN

To understand the optimal conditions necessary for successful transplantation of normal human amniotic epithelial (HAE) cells in vivo, the factors which influence the cell death were investigated. In this study, the role of prostaglandin E2 (PGE2) in HAE cells in vitro was examined.

MATERIAL OR SUBJECTS

Normal HAE cells.

TREATMENT

The HAE cells were incubated with PGE2 100 nM, 500 nM or 1,000 nM for 8 h.

METHODS

The PGE2 treated and untreated cells were collected at 2 h, 4 h and 8 h intervals and stained using trypan blue and terminal deoxynucleotidyl transferase mediated dUTP-biotin nick end labeling (TUNEL) methods to detect necrosis and apoptosis respectively.

RESULTS

Prostaglandin E2 induced more HAE cell death at 8 h treatment. The percentages of cell death induced by PGE2 100 nM, 500 nM and 1,000 nM at 8 h were 14.0 +/- 0.35 (n=9), 14.9 +/- 0.64 (n=9) and 18.3 +/- 0.65 (n=9) respectively compared to the control (7.0 +/- 0.35; n = 9) (P < 0.001) determined using trypan blue staining method. The apoptotic cell death induced by the above doses of PGE2 at 8 h were 5.7 +/- 0.6 (n=9), 7.14 +/- 0.84 (n=9) and 8.6 +/- 0.67 (n=9) respectively compared to the control (0.86 +/- 0.05; n=9) (P<0.001) determined using TUNEL method. The PGE2 induced high level cell death was via necrosis rather than apoptosis.

CONCLUSIONS

These results indicate that PGE2 is an important mediator in HAE cell death.

Malonyl CoA decarboxylase deficiency: C to T transition in intron 2 of the MCD gene

Malonyl CoA decarboxylase (MCD) is an enzyme involved in the metabolism of fatty acids synthesis. Based on reports of MCD deficiency, this enzyme is particular important in muscle and brain metabolism. Mutations in the MCD gene result in a deficiency of MCD activity, that lead to psychomotor retardation, cardiomyopathy and neonatal death. To date however, only a few patients have been reported with defects in MCD. We report here studies of a patient with MCD deficiency, who presented with hypotonia, cardiomyopathy and psychomotor retardation. DNA sequencing of MCD revealed a homozygous intronic mutation, specifically a -5 C to T transition near the acceptor site for exon 3. RT-PCR amplification of exons 2 and 3 revealed that although mRNA from a normal control sample yielded one major DNA band, the mutant mRNA sample resulted in two distinct DNA fragments. Sequencing of the patient's two RT-PCR products revealed that the larger molecular weight fragments contained exons 2 and 3 as well as the intervening intronic sequence. The smaller size band from the patient contained the properly spliced exons, similar to the normal control. Western blotting analysis of the expressed protein showed only a faint band in the patient sample in contrast to a robust band in the control. In addition, the enzyme activity of the mutant protein was lower than that of the control protein. The data indicate that homozygous mutation in intron 2 disrupt normal splicing of the gene, leading to lower expression of the MCD protein and MCD deficiency.

Possible role of fas antigen (CD 95) in human amniotic epithelial cell death: an in vitro study

Treatment of human amniotic epithelial (HAE) cells with anti-Fas monoclonal antibody (CH 11) at 100 ng/ml or 1 microg/ml for 12 or 24 h increased necrotic cell death. Apoptotic cell death induced by this antibody was significantly increased, although far fewer cells underwent apoptosis, as determined by the TUNEL method. This study suggests that Fas antigen is an important mediator in HAE cell death.

Knock-out mouse for Canavan disease: a model for gene transfer to the central nervous system

BACKGROUND

Canavan disease (CD) is an autosomal recessive leukodystrophy characterized by deficiency of aspartoacylase (ASPA) and increased levels of N-acetylaspartic acid (NAA) in brain and body fluids, severe mental retardation and early death. Gene therapy has been attempted in a number of children with CD. The lack of an animal model has been a limiting factor in developing vectors for the treatment of CD. This paper reports the successful creation of a knock-out mouse for Canavan disease that can be used for gene transfer.

METHODS

Genomic library lambda knock-out shuttle (lambdaKOS) was screened and a specific pKOS/Aspa clone was isolated and used to create a plasmid with 10 base pair (bp) deletion of exon four of the murine aspa. Following linearization, the plasmid was electroporated to ES cells. Correctly targeted ES clones were identified following positive and negative selection and confirmed by Southern analysis. Chimeras were generated by injection of ES cells to blastocysts. Germ line transmission was achieved by the birth of heterozygous mice as confirmed by Southern analysis.

RESULTS

Heterozygous mice born following these experiments have no overt phenotype. The homozygous mice display neurological impairment, macrocephaly, generalized white matter disease, deficient ASPA activity and high levels of NAA in urine. Magnetic resonance imaging (MRI) and spectroscopy (MRS) of the brain of the homozygous mice show white matter changes characteristic of Canavan disease and elevated NAA levels.

CONCLUSION

The newly created ASPA deficient mouse establishes an important animal model of Canavan disease. This model should be useful for developing gene transfer vectors to treat Canavan disease. Vectors for the central nervous system (CNS) and modulation of NAA levels in the brain should further add to the understanding of the pathophysiology of Canavan disease. Data generated from this animal model will be useful for developing strategies for gene therapy in other neurodegenerative diseases.

Improved Weather and Seasonal Climate Forecasts from Multimodel Superensemble

A method for improving weather and climate forecast skill has been developed. It is called a superensemble, and it arose from a study of the statistical properties of a low-order spectral model. Multiple regression was used to determine coefficients from multimodel forecasts and observations. The coefficients were then used in the superensemble technique. The superensemble was shown to outperform all model forecasts for multiseasonal, medium-range weather and hurricane forecasts. In addition, the superensemble was shown to have higher skill than forecasts based solely on ensemble averaging.