Mechanistic evaluation of the signaling events regulating curcumin-mediated chemosensitization of breast cancer cells to 5-fluorouracil

5-Fluorouracil (5-FU) is the first rationally designed antimetabolite, which achieves its therapeutic efficacy through inhibition of the enzyme thymidylate synthase (TS), which is essential for the synthesis and repair of DNA. However, prolonged exposure to 5-FU induces TS overexpression, which leads to 5-FU resistance in cancer cells. Several studies have identified curcumin as a potent chemosensitizer against chemoresistance induced by various chemotherapeutic drugs. In this study, we report for the first time, with mechanism-based evidences, that curcumin can effectively chemosensitize breast cancer cells to 5-FU, thereby reducing the toxicity and drug resistance. We found that 10 μM 5-FU and 10 μM curcumin induces a synergistic cytotoxic effect in different breast cancer cells, independent of their receptor status, through the enhancement of apoptosis. Curcumin was found to sensitize the breast cancer cells to 5-FU through TS-dependent downregulation of nuclear factor-κB (NF-κB), and this observation was confirmed by silencing TS and inactivating NF-κB, both of which reduced the chemosensitizing efficacy of curcumin. Silencing of TS suppressed 5-FU-induced NF-κB activation, whereas inactivation of NF-κB did not affect 5-FU-induced TS upregulation, confirming that TS is upstream of NF-κB and regulates the activation of NF-κB in 5-FU-induced signaling pathway. Although Akt/PI3kinase and mitogen-activated protein kinase pathways are activated by 5-FU and downregulated by curcumin, they do not have any role in regulating the synergism. As curcumin is a pharmacologically safe and cost-effective compound, its use in combination with 5-FU may improve the therapeutic index of 5-FU, if corroborated by in vivo studies and clinical trials.

Dynamics of mononuclear cadmium beta-lactamase revealed by the combination of NMR and PAC spectroscopy

The two metal sites in cadmium substituted beta-lactamase from Bacillus cereus 569/H/9 have been studied by NMR spectroscopy ((1)H, (15)N, and (113)Cd) and PAC spectroscopy ((111m)Cd). Distinct NMR signals from the backbone amides are identified for the apoenzyme and the mononuclear and binuclear cadmium enzymes. For the binuclear cadmium enzyme, two (113)Cd NMR signals (142 and 262 ppm) and two (111m)Cd PAC nuclear quadrupole interactions are observed. Two nuclear quadrupole interactions are also observed, with approximately equal occupancy, in the PAC spectra at cadmium/enzyme ratios < 1; these are different from those derived for the binuclear cadmium enzyme, demonstrating interaction between the two metal ion binding sites. In contrast to the observation from PAC spectroscopy, only one (113)Cd NMR signal (176 ppm) is observed at cadmium/enzyme ratios < 1. The titration of the metal site imidazole (N)H proton signals as a function of cadmium ion-to-enzyme ratio shows that signals characteristic for the binuclear cadmium enzyme appear when the cadmium ion-to-enzyme ratio is between 1 and 2, whereas no signals are observed at stoichiometries less than 1. The simplest explanation consistent with all data is that, at cadmium/enzyme ratios < 1, the single Cd(II) is undergoing exchange between the two metal sites on the enzyme. This exchange must be fast on the (113)Cd NMR time scale and slow on the (111m)Cd PAC time scale and must thus occur in a time regime between 0.1 and 10 micros.

The value of partial sleep deprivation as a routine measure in pediatric electroencephalography

For more than 50 years it has been known that in patients with epilepsy, sleep markedly increases the diagnostic yield of the electroencephalogram (EEG). Sleep deprivation could have an additional activating role. Many laboratories do not use these methods routinely but reserve them for a second EEG if equivocal or negative findings are present in the initial EEG. We studied a regime of routine partial sleep deprivation without the use of hypnotic agents in 396 children younger than age 17 years who were referred for EEG with a diagnosis of epilepsy or suspected epilepsy. Sleep was achieved for the EEG in 77% (96% in the 1 month to 2 year age group, 78% in the 2 to 8 year age group, and in 64% of those more than 8 years old). In a comparison group of 72 children who had not been sleep-deprived, sleep was achieved in 44% (69% of those less than 2 years old, 27% of those between 2 and 8 years of age, and 33% of those older than 8 years). The differences were highly significant. The regime was well tolerated. Routine partial sleep deprivation is a practical and effective method of obtaining sleep and thus maximizing the information obtained from a single EEG.

Chronic experimental allergic neuritis. An electrophysiological and histological study in the rabbit

Ten adult outbred New Zealand white rabbits were inoculated with a single multiportal dose of purified bovine peripheral nerve myelin and Freund's adjuvant containing 500 mg of nerve antigen. Seven animals developed chronic relapsing or progressive disease which was followed by clinical examination for 14 months. Electrophysiological studies showed marked slowing of motor conduction velocity, dispersion of the evoked muscle action potential (MAP) and reduction in amplitude of the MAP derived from distal stimulation. Histological examination of the peripheral nervous system showed at 12 months a marked hypertrophic neuropathy in the nerve roots with well developed onion bulbs, active demyelination and a moderate nerve fibre loss. It is suggested that these animals provide a reliable and predictable model for human chronic inflammatory demyelinating polyneuropathy (CIDP) which should prove valuable for therapeutic trials and studies of pathogenetic mechanisms.

Benign intracranial hypertension in childhood: a review of 23 patients

Twenty-three patients with benign intracranial hypertension (BIH) were seen at the Royal Alexandra Hospital for Children, Sydney over an 18 year period to 1988. Age at presentation ranged from 6 months to 13 years and 5 months. The female to male ratio was 2.3:1. The aetiological factors (sometimes multiple) included: chronic middle ear infection, 30%; dural sinus thrombosis, 22%; head injury, 13%; Vitamin A overdosage, 4%; tetracycline exposure, 4%; and no apparent cause, 43%. Headache was the most common presenting symptom occurring in 91% of patients, followed by vomiting in 65% and blurred or double vision in 57%. Papilloedema occurred in 96% of patients, abducens palsy was noted in 48% and visual impairment in 45%. All patients improved clinically after treatment, one with lumbar puncture only. Of 17 patients treated with steroids, 10 patients recovered and seven patients went on to lumboperitoneal shunt. Two patients recovered with steroid and diuretic treatment. Of two patients initially treated with diuretics only, one recovered and one subsequently required a shunt. Only one patient was initially treated with a lumboperitoneal shunt. Three of the shunted patients had shunt block requiring revision. None had permanent visual loss or other significant sequelae. The visual prognosis of BIH in childhood is good. In view of the relatively high complication rate of steroids and shunting, a controlled comparison of steroid vs acetazolamide/diuretic therapy should be undertaken.

Acute flaccid paralysis in Australian children

OBJECTIVES

To describe the epidemiology and causes of acute flaccid paralysis (AFP) in Australian children, and the clinical features of the two most common causes of AFP, Guillain-Barré syndrome and transverse myelitis.

METHODS

Monthly active surveillance for AFP was carried out through the Australian Paediatric Surveillance Unit, with AFP defined as 'acute onset of flaccid paralysis in one or more limbs or of bulbar paralysis in any child less than 15 years of age'.

RESULTS

Between March 1995 and December 1999, 143 cases of AFP were reported (approximately 0.8 per 100000 children < 15 years of age per annum). The age range was 2 months-14 years and 59% were boys. Out of these children, 137 (96%) were hospitalized and 47 required intensive care. No case of wild or vaccine-associated poliomyelitis was identified. The most common causes of AFP were Guillain-Barré syndrome in 67 (47%) and transverse myelitis in 27 (19%). Other diagnoses included acute disseminated encephalomyelitis, trauma, tick-bite paralysis and infantile botulism.

CONCLUSION

The participation of paediatricians in AFP surveillance contributed to the accreditation of Australia (along with the other 36 countries of the western Pacific region) as 'polio free' by the World Health Organization in October 2000. The surveillance also provided data on the frequency of AFP and identified Guillain-Barré syndrome and transverse myelitis as the most common diagnoses. In this large national series, many other conditions that may present as non-polio AFP were identified.

Dural tears associated with lumbar burst fractures

A retrospective review of 817 spinal fracture patients revealed a 7.7% (20 of 258) incidence of dural tears in surgically treated patients. Dural tears were most common in the lumbar burst fractures (10 of 85). Twenty-five percent of patients with lumbar spine burst fractures and a neurologic deficit had a dural tear requiring repair. Eighty-six percent of patients with lumbar burst injuries and dural tears had a neurologic deficit. An initial posterior approach with inspection of the dura and stabilization of the fracture is recommended when treating lumbar burst fractures with a neural deficit.

Modulation of linguistic prediction by TDCS of the right lateral cerebellum

It has been postulated recently that the cerebellum contributes the same prediction and learning functions to linguistic processing as it does towards motor control. For example, repetitive TMS over posterior-lateral cerebellum caused a significant loss in predictive language processing, as assessed by the latency of saccades to target items of spoken sentences, using the Visual World task. We aimed to assess the polarity-specific effects of cerebellar TDCS, hypothesising that cathodal TDCS should impair linguistic prediction, and anodal TDCS facilitate it. Our design also tested whether TDCS modulated associative learning in this task. A between groups (sham, anodal, cathodal) design was used, with concurrent stimulation during performance of a manual variation of the Visual World paradigm, and with assessment of latency reduction over repeated presentations of the spoken sentences. Mixed model ANOVA was used to analyse change in response latency. Cathodal TDCS decreased participants' response time advantage for the predictable sentence items without change for non-predictable items, consistent with the previous TMS results. Furthermore, anodal stimulation enhanced the response time advantage for the predictable items, again without change in latencies for non-predictive items. We found a clear practice-based effect over 4 blocks. However, this difference was not significantly modulated by either anodal or cathodal stimulation. Our results therefore support the hypothesis that cerebellum contributes to predictive language processing, mirroring its predictive role in motor control, but we do not yet have evidence that the learning process was affected by cerebellar TDCS.

Improving the process quality using statistical design of experiments: a case study

A technique known as Statistical design of experiments is a powerful technique for process characterization, optimization, and modeling. It has been widely accepted in manufacturing industry for improving product performance and reliability, process capability, and yield. This article illustrates the application of statistical design of experiments based on the Taguchi approach in a certain company that manufactures electromagnetic clutch coils. The objective of the study was to improve the quality of the existing process and thereby achieve heightened customer satisfaction for the product. An eight-trial experiment was conducted with the aim of reducing the number of rejects from the process. The expected savings per month was estimated to be over $11,500. The results of the study have provided a greater stimulus for the wider application of statistical design of experiments in other core processes within the company.

The assessment of quality in medical diagnostic tests: a comparison of ROC/Youden and Taguchi methods

Diagnostic tests are widely used in many areas of modern technological society, but they are of particular importance in medicine, where early and accurate diagnosis can decrease morbidity and mortality rates of disease. How the quality of diagnostic information and decisions should be measured in a meaningful way has become increasingly important in recent years as an abundance of new diagnostic tests have been introduced. A number of seemingly independent indices are studied for evaluating diagnostic performance such as the receiver operating characteristic curves and signal-to-noise ratios. Designing robustness into diagnostic tests can only be achieved by minimizing the variation in the total number of false diagnosis. This article has undertaken a comparison of signal-to-noise ratios developed by Taguchi in quality engineering and system performance in manufacturing industry. A hybrid is also computed and its relevance to physicians as an efficient assessment method is proposed and strongly encouraged.

Gauge Capability Analysis: classical versus ANOVA

In order to use Statistical Process Control (SPC) efficiently and effectively in today's modern industrial environment, it is essential to analyze and determine the extent of gauge variability. The variation that occurs on a control chart is essentially a combination of product and gauge variation. Studies of measurement or gauge variation are absolutely a waste of resources unless they can lead to a substantial reduction in process variability or to an improvement in process and product quality. The goal of gauge capability analysis is an understanding and quantification of the various sources of variability present in the measurement process. The purpose of this paper is to illustrate the fundamental difference between Classical Gauge Capability Analysis (CGCA) and the use of a more powerful approach based on the Analysis of Variance (ANOVA). The author recommends that the latter approach is more useful and powerful in the presence of an interaction between the parts and the operators involved in the measurement process. An example is illustrated in the paper to demonstrate the two approaches.

Complete duplication of female urethra with vaginal atresia and supernumerary kidney

Supernumerary kidney is the rarest of renal anomalies and complete duplication of the female urethra with a single bladder is even more unusual. A case of a supernumerary kidney associated with complete urethral duplication in a female patient with vaginal atresia is reported.

A novel computer-assisted technique for pedicle screw insertion

BACKGROUND

Commercially available systems for computer-assisted pedicle screw placement are prohibitively expensive, even in advanced countries. The advantage of the great accuracy of computer-assisted systems for pedicle screw insertion makes them highly desirable and essential for current spinal surgeries.

METHODS

We have tried to develop a new software for pedicle screw placement, based on paired point matching.

RESULTS

The newly developed software is much less expensive and is an excellent educational tool. Its accuracy has been established by a cadaveric study, described in this paper.

CONCLUSIONS

The cadaveric study supports the view that computer-assisted pedicle screw fixation using the newly developed software is superior to the conventional fluoroscopic method, especially with regard to the thoracic spine, where a higher degree of accuracy is needed. Further clinical studies are planned and the software needs further refinement for complex clinical situations.

Tips, Tricks, and Potential Pitfalls of CRISPR Genome Editing in Saccharomyces cerevisiae

The versatility of clustered regularly interspaced short palindromic repeat (CRISPR)-associated (Cas) genome editing makes it a popular tool for many research and biotechnology applications. Recent advancements in genome editing in eukaryotic organisms, like fungi, allow for precise manipulation of genetic information and fine-tuned control of gene expression. Here, we provide an overview of CRISPR genome editing technologies in yeast, with a particular focus on Saccharomyces cerevisiae. We describe the tools and methods that have been previously developed for genome editing in Saccharomyces cerevisiae and discuss tips and experimental tricks for promoting efficient, marker-free genome editing in this model organism. These include sgRNA design and expression, multiplexing genome editing, optimizing Cas9 expression, allele-specific editing in diploid cells, and understanding the impact of chromatin on genome editing. Finally, we summarize recent studies describing the potential pitfalls of using CRISPR genome targeting in yeast, including the induction of background mutations.

A method of repair of recurrent recto-vesico-prostatic fistula following prostatectomy

A recto-vesico-prostatic fistula is a rare complication of prostatectomy. Because of its rarity the literature on the subject is scanty and an individual surgeon's experience in the field is limited. Recurrence of such fistulas are common after repair, posing a difficult problem for the surgeon. A method of repair is presented, which is a combination of procedures based on sound surgical principles. This repair also holds a promise of cure for recurrent fistulas.

Systematic review and meta-analysis of external ventricular drain placement accuracy and narrative review of guidance devices

BACKGROUND

Insertion of external ventricular drain (EVD) is one of the most common neurosurgical procedures performed worldwide. This is generally performed freehand, on the basis of anatomical landmarks. There is significant variability in the reported accuracy of freehand placement, lacking Level I evidence. We present the first meta-analysis of freehand EVD placement accuracy and technologies or techniques to enhance accuracy.

METHODS

We report a systematic review of the Pubmed, Embase, and Cochrane Central databases according to MOOSE (Meta-analysis Of Observational Studies) guidelines. 37 studies were included for qualitative analysis and 19 studies (2983 cases) for quantitative analysis.

RESULTS

There is substantial heterogeneity in the outcome measures used to report EVD placement accuracy. Of those nineteen studies reporting accuracy using the Kakarla grading system the mean rate of ideal ipsilateral frontal horn placement was 73% (standard deviation ±7%). The use of formal stereotaxic guidance is consistently reported to improve accuracy to >90%, although with variable outcome measures. However, the reported efficacy of other guidance devices or techniques is highly variable. The quality of studies directly comparing all existing non-stereotaxic devices with freehand EVD placement is poor and precludes any assertion of superiority to freehand insertion.

CONCLUSIONS

We provide the first meta analysis of freehand placement accuracy. There is insufficient data to perform a meta-analysis of the relative efficacy of interventions to improve accuracy. Qualitative synthesis of reports of stereotaxic guidance is suggestive of higher accuracy than freehand placement.

Bulbar and pseudobulbar palsy complicating therapy with high-dose cytosine arabinoside in children with leukemia

Three of 38 children given high-dose cytosine arabinoside therapy developed a previously undescribed complication. Neurological problems are a frequent occurrence in patients given this therapy, particularly cerebellar ataxia, but the development of bulbar and pseudobulbar palsy has not been reported. In two of these cases, it was sufficiently marked for the course of treatment to be curtailed and occurred at a relatively low cumulative dose of the drug. Neurotoxicity can occur at any time using high-dose cytosine therapy.

Surveillance of acute flaccid paralysis in Australia, 1995-97. Australian Paediatric Surveillance Unit

OBJECTIVE

Acute flaccid paralysis (AFP) surveillance in Australia as part of the World Health Organization (WHO) certification process for polio eradication in the Western Pacific region.

METHODS

Active monthly AFP surveillance through the Australian Paediatric Surveillance Unit, from March 1995 to December 1997.

RESULTS

Based on 80 cases, the reported overall rate of AFP was 0.73 per 10(5) children < 15 years (below the expected 1 per 10(5)). The major causes of AFP were Guillain-Barré syndrome (51%) and transverse myelitis (19%). According to the WHO virological classification, there was no case of poliomyelitis, 37.5% were 'non-polio' and 62.5% cases were 'polio compatible' due to inadequate stool testing and follow-up. However, case review by an expert panel enabled 95% to be classified as 'non-polio'.

CONCLUSION

Australia must improve AFP surveillance to confirm absence of wild poliovirus. Paediatricians can help Australia meet its certification requirements and contribute to the global eradication effort by reporting and investigating all cases of AFP.

Teaching fractional factorial experiments via course delegate designed experiments

Industrial experiments are fundamental in enhancing the understanding and knowledge of a process and product behavior. Designed industrial experiments assist people in understanding, investigating, and improving their processes. The purpose of a designed experiment is to understand which factors might influence the process output and then to determine those factor settings that optimize the process output. Teaching "design of experiments" using textbook examples does not fully shed light on how to identify and formulate the problem, identify factors, and determine the performance of the physical experiment. Presented here is an example of how to teach fractional factorial experiments in a course on designed experiments. Also presented is a practical, hands-on experiment that has been found to be extremely successful in instilling confidence and motivation in course delegates. The experiment provides a great stimulus to the delegates for the application of experimental design in their own work environment.

A practical methodology for analysing and improving the measurement system

Measurement systems are used widely in manufacturing organisations in order to make many important decisions. These decisions range from the acceptability of a given product against tolerance requirements to the level of statistical control of a process or its capability to consistently perform a given task. In most situations, however, little thought is given to the quality of the data generated by such measurement processes. By using potentially flawed data in making fundamental manufacturing decisions, organisations undermine the quality of the decision-making process itself. This paper reviews the approaches presently available from both a technical and a practical point of view, based on the priorities of process improvement practitioners. The conclusion of the paper is that the Evaluation of the Measurement Process proposed by Wheeler and Lyday offers the best balance of accuracy and utility.

Vascular access for extracorporeal therapy in the rabbit

A technique allowing short-term blood access for extracorporeal therapy in rabbits is described. The technique utilizes silicone rubber cannulae and teflon vessel tips to construct an externalized carotid-jugular arteriovenous shunt. The insertion procedure takes 1 h and extracorporeal blood flows in excess of 10 ml/min are obtainable for up to 7 days. Blood flow may still be obtained following shunt clotting by insertion of smaller diameter catheters through the arterial cannula. This technique has been successfully used for extracorporeal therapy in rabbit disease models.

A new insight into the Taguchi method

To obtain high quality products at low cost and in a short time is an economical and technological challenge to today's engineering community. Design of Experiments based on the Taguchi approach is a powerful technique to attain this objective. In some processes, it is necessary to consider not only two factors but also the ratio of their levels 'as a factor.' This paper introduces a new look at the Taguchi method that makes it possible, by choosing the proper levels, to evaluate the ratio of two factors as a new factor in the same orthogonal array. An experiment to study four three-level factors was designed, and a case study is presented to illustrate the ratio of the two three-level factors as a new factor using the same L9 orthogonal array.