DNA damage by OH radicals produced using intense, ultrashort, long wavelength laser pulses.

We probe femtosecond laser induced damage to aqueous DNA, relying on strong-field interaction with water wherein electrons and free radicals are generated in situ; these, in turn, interact with DNA plasmids under physiological conditions, producing nicks. Exposure to intense femtosecond pulses of 1350 and 2200 nm light induces single strand breaks and double strand breaks (DSBs) in DNA. At the longer wavelength (and at higher intensities), rotationally hot OH radicals induce DSBs, producing linear DNA. Strand breaks occur due to single or multiple OH hits on DNA. With 2200 nm light, DSBs are formed mostly by the action of two OH radicals; use of OH scavengers establishes that the probability of a two-hit event reduces much faster than a one-hit event as scavenger concentration is increased. Thermal effects do not induce DSBs with 2200 nm light.

Surgical management of osteochondritis dissecans of the knee in the paediatric population: a systematic review addressing surgical techniques.

PURPOSE: Several case series have been published exploring a variety of surgical treatments for osteochondritis dissecans (OCD) in patients 18 years and younger, but a systematic review is currently lacking. This systemic review identifies the various surgical techniques reported in the literature for treating OCD and assesses the effectiveness of these treatments based on functional outcomes and radiographic healing. METHODS: A search of the EMBASE and MEDLINE databases was performed to identify clinical studies reporting outcomes of surgical management of OCD in the knee. A quality assessment of the included articles was conducted independently by 2 reviewers using a quality assessment tool developed by Yang et al. RESULTS: A total of 25 papers including 470 patients aged ≤18 years (516 lesions) met the eligibility criteria and were reviewed. Surgical techniques for stable lesions included (arthroscopic and open) transarticular drilling, either alone (41%) or with bioabsorbable pin fixation (3%), extra-articular drilling (29%) and fixation with bioabsorbable screws (4%) or bone pegs (4%). For unstable lesions, surgical techniques included (arthroscopic and open) fixation with bioabsorbable pins (9%), metal screws (4%), bone pegs (4 %), osteochondral plugs (3%) or bioabsorbable screws (2%), as well as transarticular drilling with bioabsorbable pin fixation (3%) and drilling with metal screw fixation (2%). CONCLUSION: The most common techniques were transarticular drilling for stable lesions and bioabsorbable pin fixation for unstable lesions. The key findings were that the vast majority of lesions healed postoperatively, regardless of technique, and that high-quality trials are required to more appropriately compare the effectiveness of techniques. LEVEL OF EVIDENCE: Systematic review, Level IV.

Effect of intense, ultrashort laser pulses on DNA plasmids in their native state: strand breakages induced by in situ electrons and radicals.

Single strand breaks are induced in DNA plasmids, pBR322 and pUC19, in aqueous media exposed to strong fields generated using ultrashort laser pulses (820 nm wavelength, 45 fs pulse duration, 1 kHz repetition rate) at intensities of 1-12 TW cm(-2). The strong fields generate, in situ, electrons and radicals that induce transformation of supercoiled DNA into relaxed DNA, the extent of which is quantified. Introduction of electron and radical scavengers inhibits DNA damage; results indicate that OH radicals are the primary (but not sole) cause of DNA damage.

Prioritisation of vascular outpatient appointments cannot be based on referral letters alone.

BACKGROUND: Vascular referrals include patients with conditions varying from varicose veins of cosmetic nuisance to patients with critical ischaemia, transient ischaemic attacks and abdominal aortic aneurysms. A large number of such referrals are received each week from general practitioners. It is important to prioritise patients with conditions that need to be dealt with quickly. OBJECTIVE: We prospectively reviewed referral letters to two vascular units, one in South Wales and one in the Oxford region to assess whether prioritisation can be made on the basis of referral letters. MATERIAL AND METHODS: All GP referral letters were studied for four months. Only patients with lower limb ischaemic symptoms were included. Degree of urgency requested by the GP was also noted. RESULTS: Of 174 referrals for potential lower limb ischaemia analysed, 145 (83%) proved to be due to peripheral vascular disease. Of these 145 referrals, 72% were referred for claudication. Only 37% and 13% respectively mentioned claudication distance and/or rest pain. Risk factors with reference to diabetes, hypertension, hyperlipidaemia, ischaemic heart disease, atrial fibrillation, cerebrovascular disease and smoking were made in 19%, 43%, 23%, 23%, 10%, 14%, 31% of letters respectively. Clinical signs were poorly documented, with 90% of referrals failing to mention presence or absence of critical ischaemic signs. The GP's own assessment of urgency was not stated in 66% of letters, without which only 3% of patients were seen in the clinic within four weeks, compared with 22% in those in whom urgency was stated. Six per cent of patients when reviewed in outpatients were found to have sufficiently severe symptoms to warrant immediate admission. Regional variation was observed with 57% of Royal Glamorgan Hospital referral letters documenting degree of urgency compared with only 23% of Royal Berkshire Hospital letters (p = < 0.0001). CONCLUSION: Most referral letters were poorly documented with regard to key symptoms, risk factors and clinical signs. The degree of urgency was often not stated. The creation of referral protocols is now being considered.

Management of cardiovascular risk factors by primary care physicians in patients with peripheral arterial disease.

BACKGROUND: Patients with significant coronary artery disease (CAD) are now intensively treated by primary care physicians predominantly because of government pressure and remuneration to prescribe anti-platelet and anti-hyperlipidaemic drugs. Peripheral arterial disease (PAD) with the identical risk factors appeared to us to be less intensively investigated and treated by primary care physicians. OBJECTIVE: To review the treatment of risk factors in all patients referred to two vascular clinics with a diagnosis of suspected PAD. DESIGN: Cross-sectional survey. SETTING: Vascular outpatient clinic in two district general hospitals. PARTICIPANTS: 124 consecutive new patients were studied to determine risk factors and appropriate treatment. RESULTS: Of the 124 patients, 85 (68%) were confirmed to have PAD without evidence of symptomatic CAD. In the PAD alone group, less than 25% received anti-smoking advice (p < 0.0001) and only 36% were prescribed anti-platelet drugs (p = 0.016). Seventy-three per cent of the overall referred patients with hypertension had been treated for this condition and the blood pressure was normal in 71% of the patients with PAD. In patients with hyperlipidaemia, statins had been prescribed in 92% of patients with coexistent symptomatic CAD, but only in 64% of patients with PAD alone (p = 0.009). In the patients with diabetes, only 66% of the PAD alone group had adequate control of their blood sugar (p = 0.185). CONCLUSIONS: It would appear that patients with CAD and PAD are being treated successfully for their risk factors, but patients with PAD alone, sharing the same common risk factors, are being less than optimally treated.

Psychogenic coma after dental surgery under general anaesthesia.

Delayed awakening after general anaesthesia due to psychogenic coma is a phenomenon that rarely presents to the oral and maxillofacial surgeon. A case of psychogenic coma following general anaesthesia for dental extractions is presented here. It is recommended that patients at risk of conversion disorder should be counselled about the risks of psychogenic coma. Early diagnosis of this condition could lead to better patient management.

The influence of hyperbaric oxygen on the outcome of patients treated for osteoradionecrosis: 8 year study.

This study was a retrospective review of treatment outcomes of osteoradionecrosis (ORN) of the mandible over an 8-year period, with specific reference to the role of hyperbaric oxygen therapy (HBOT). The presentation and management of 23 patients treated for ORN was studied by categorising them into three grades according to the severity of clinical and radiographic involvement. At presentation there were 13 patients with grade I ORN, six patients with grade II ORN and four patients with grade III ORN. HBOT was given to 10 patients in the grade I group, four patients in the grade II group and two patients in the grade III group. Overall eight patients (62%) with grade I, three patients (50%) with grade II and two patients (50%) with grade III were cured. In the patients who received HBOT the cure rate was 12.5% whilst in those without HBOT it was 86%. Although the cohort was small it seems that HBOT was of little benefit. HBOT is demanding for patients and has cost implications for the NHS; hence further clinical outcome data are urgently required with regard to its role in the management of ORN.

Non Surgical Management of Pseudoaneurysms.

BACKGROUND: The incidence of pseudoaneurysm has increased due to the large number of vascular procedures performed and the widespread use of anticoagulation therapy during procedures. Non-invasive methods for management of pseudoaneurysms comprise of ultrasound guided compression (USGC), thrombin therapy, arterial embolisation and endovascular stent graft insertion. We discuss our experience in the management of fourteen cases of pseudoaneurysms using non surgical techniques. METHODS: During a two year period, fourteen patients presenting with pseudoaneurysms of different regions were treated. RESULT: Of the fourteen patients, eleven were iatrogenic and three were attributable to trauma. There were six cases of pseudoaneurysms of the femoral artery following coronary angiography studies. One patient developed pseudoaneurysm of right popliteal artery after external fixation of fracture right tibia and fibula. Three cases of renal artery pseudoaneurysms occurred following percutaneous nephrolithotomy (PCNL). The cases were evaluated using a varying combination of color doppler, multidetector computerised tomography (CT) and angiography. These cases were treated with ultrasound guided compression (USGC), stent graft and coil embolisation. The selection of method was based on the location and size of pseudoaneurysms besides the efficacy of the technique. USGC was performed in seven, of which six were in the femoral artery and one supraorbital. The technique was unsuccessful in three of the seven, wherein stent graft was deployed in the femoral artery. Coil embolisation was utilised in three cases of renal artery pseudoaneurysms following PCNL. CONCLUSION: Follow up with color doppler and CT angiography within a week, 6 and 12 months period showed successful regression of pseudoaneurysms in all cases.

Enhanced recovery in patients having free tissue transfer for head and neck cancer: does it make a difference?

Programmes for Enhanced Recovery after Surgery (ERAS) accelerate recovery, reduce morbidity, and shorten hospital stay in a wide range of surgical specialties. We established a standardised multimodal ERAS pathway for patients who were being treated by free tissue transfer for head and neck cancer to evaluate its benefit. Our primary outcome was duration of hospital stay, and secondary outcomes included complications, number of days to first mobilisation, and readmission rates. We compared 100 consecutive patients who followed the ERAS programme with a control group of 40 consecutive patients who had free tissue transfer before the ERAS programme was introduced. There was a significantly reduced median duration of stay from 14days in the control group to 10days in the ERAS group. Patients in the ERAS group who were aged over 60 years, or had tracheostomies, or who required bone resection also had a significantly reduced duration of stay. There was no difference between morbidity and readmission rates, although patients in the ERAS group were mobilised significantly earlier. The ERAS programme is safe and effective for patients who are treated by free tissue transfer for head and neck cancer, and potentially reduces their duration of stay in hospital.

Biotechnological Applications of Marine Enzymes From Algae, Bacteria, Fungi, and Sponges.

Diversity is the hallmark of all life forms that inhabit the soil, air, water, and land. All these habitats pose their unique inherent challenges so as to breed the "fittest" creatures. Similarly, the biodiversity from the marine ecosystem has evolved unique properties due to challenging environment. These challenges include permafrost regions to hydrothermal vents, oceanic trenches to abyssal plains, fluctuating saline conditions, pH, temperature, light, atmospheric pressure, and the availability of nutrients. Oceans occupy 75% of the earth's surface and harbor most ancient and diverse forms of organisms (algae, bacteria, fungi, sponges, etc.), serving as an excellent source of natural bioactive molecules, novel therapeutic compounds, and enzymes. In this chapter, we introduce enzyme technology, its current state of the art, unique enzyme properties, and the biocatalytic potential of marine algal, bacterial, fungal, and sponge enzymes that have indeed boosted the Marine Biotechnology Industry. Researchers began exploring marine enzymes, and today they are preferred over the chemical catalysts for biotechnological applications and functions, encompassing various sectors, namely, domestic, industrial, commercial, and healthcare. Next, we summarize the plausible pros and cons: the challenges encountered in the process of discovery of the potent compounds and bioactive metabolites such as biocatalysts/enzymes of biomedical, therapeutic, biotechnological, and industrial significance. The field of Marine Enzyme Technology has recently assumed importance, and if it receives further boost, it could successfully substitute other chemical sources of enzymes useful for industrial and commercial purposes and may prove as a beneficial and ecofriendly option. With appropriate directions and encouragement, marine enzyme technology can sustain the rising demand for enzyme production while maintaining the ecological balance, provided any undesired exploitation of the marine ecosystem is avoided.

Optical control of filamentation-induced damage to DNA by intense, ultrashort, near-infrared laser pulses.

We report on damage to DNA in an aqueous medium induced by ultrashort pulses of intense laser light of 800 nm wavelength. Focusing of such pulses, using lenses of various focal lengths, induces plasma formation within the aqueous medium. Such plasma can have a spatial extent that is far in excess of the Rayleigh range. In the case of water, the resulting ionization and dissociation gives rise to in situ generation of low-energy electrons and OH-radicals. Interactions of these with plasmid DNA produce nicks in the DNA backbone: single strand breaks (SSBs) are induced as are, at higher laser intensities, double strand breaks (DSBs). Under physiological conditions, the latter are not readily amenable to repair. Systematic quantification of SSBs and DSBs at different values of incident laser energy and under different external focusing conditions reveals that damage occurs in two distinct regimes. Numerical aperture is the experimental handle that delineates the two regimes, permitting simple optical control over the extent of DNA damage.

Optically-controllable, micron-sized motor based on live cells.

We demonstrate rotation of live Chlamydomonas reinhardtii cells in an optical trap; the speed and direction of rotation are amenable to control by varying the optical trapping force. Cells rotate with a frequency of 60-100 rpm; functional flagella are shown to play a decisive role in rotation. The rotating cells generate torque (typically ~7500-12000 pN nm) that is much larger than that generated chemically by a dynein head in vitro (40 pN nm). The total force associated with a rotating live cell (~10 pN) suggests that activity of only a small fraction (~5%) of dynein molecules per beat cycle is sufficient to generate flagellar motion.

A comparison of three modelling approaches for quantitative risk assessment using the case study of Salmonella spp. in poultry meat.

A comprehensive review of both the scientific literature and industry practices was undertaken to identify and quantify all sources of contamination throughout the entire poultry meat production chain by Salmonella spp. This information was used to develop a quantitative risk assessment (QRA) model for Salmonella in the production chain from the breeder farm to the chilled carcass. This was subsequently used as the basis on which to compare the merits of three approaches to QRA modelling in such systems. The original model used a Bayesian Network (BN). The second method was a Markov chain Monte Carlo (MCMC) approach, a numerical Bayesian technique which retained a similar network structure but allowed further development, such as the separation of variability and uncertainty. The third method was a more detailed simulation model. The BN responds immediately to changes, such as entering evidence, because it does not use simulation and can propagate information from any point in the network to all others by Bayesian inference. However, it requires all the variables to be discrete, which introduces errors if continuous variables have to be discretized. These errors can accumulate. The MCMC approach does not require discrete variables while retaining some of the properties of the BN model, such as the ability to draw inferences from evidence. Finally, the simulation offers greater flexibility, such as consideration of the individual carcass, but may be more complex to implement as a result and sacrifices the ability to propagate evidence.

Oxcarbazepine (Trileptal) as monotherapy in patients with partial seizures.

OBJECTIVE: To evaluate the efficacy and safety of oxcarbazepine (OXC) as monotherapy for patients with uncontrolled partial seizures. METHODS: A multicenter, double-blind, randomized, parallel-group, dose-controlled monotherapy trial compared OXC at 2400 mg/day with OXC at 300 mg/day in patients with uncontrolled partial-onset seizures previously receiving carbamazepine (CBZ) monotherapy. During a 28-day open-label conversion phase, patients were tapered off CBZ and titrated to OXC 2400 mg/day. After a 56-day open-label baseline phase on OXC 2400 mg/day, patients entered a 126-day double-blind treatment phase in which they were randomized to continue OXC at 2400 mg/day or were down titrated over 6 weeks to OXC at 300 mg/day. Patients met the efficacy endpoint by completing the double-blind treatment phase or by meeting one of four predefined exit criteria. The primary efficacy variable was time to meeting one of the exit criteria. The secondary efficacy variable was the percentage of patients meeting one of the exit criteria in each of the two treatment groups. RESULTS: Of the 143 patients enrolled, 96 were randomized in the double-blind treatment phase. Time to meeting an exit criterion was significantly in favor of the OXC 2400 mg/day group (p = 0.0001). The median time to meeting an exit criterion was 68 days for the OXC 2400 mg/day Group and 28 days for the OXC 300 mg/day Group. In addition, the percentage of patients meeting one of the exit criteria was significantly lower for the OXC 2400 mg/day Group (p = 0.0001). Overall, OXC was well tolerated with the most common adverse events consisting of fatigue, nausea, ataxia, and headache. CONCLUSION: This trial demonstrated that OXC at 2400 mg/day is well tolerated and efficacious when administered as monotherapy in patients with uncontrolled partial onset seizures.

Oxcarbazepine monotherapy for partial-onset seizures: a multicenter, double-blind, clinical trial.

OBJECTIVE: To evaluate the safety and efficacy of oxcarbazepine (OXC) 2,400 mg/day versus OXC 300 mg/day monotherapy in patients with medically refractory partial epilepsy. BACKGROUND: OXC is primarily metabolized by reductase enzymes and, consequently, has a low propensity to inhibit or induce oxidative enzymes and a minimal potential for drug-drug interactions. The efficacy of OXC as monotherapy was shown in several comparative trials in patients with newly diagnosed epilepsy and in hospitalized patients undergoing evaluation for epilepsy surgery. METHODS: A multicenter, double-blind, randomized, parallel-group trial design was chosen to assess the antiepileptic efficacy of OXC as monotherapy in a refractory epilepsy patient population. Outpatients aged 12 years or older with inadequately controlled partial seizures, with or without secondarily generalized seizures, were enrolled. Patients finished the trial by completing the double-blind phase or by meeting one of four predefined exit criteria: a twofold increase in partial seizure frequency in any 28-day period relative to baseline; a twofold increase in the highest consecutive 2-day partial seizure frequency relative to baseline; occurrence of a single generalized seizure if none occurred during the 6 months prior to randomization; or prolongation or worsening of generalized seizure duration or frequency requiring intervention. Adverse events (AEs), vital signs, and clinical laboratory tests were evaluated. RESULTS: The percentage of patients meeting one of the exit criteria was significantly lower (p < 0.0001) for the OXC 2400 mg/day group (14/34; 41%) than the OXC 300 mg/day group (42/45; 93%). In addition, there was a significant difference in time to exit in favor of the OXC 2400 mg/day group (p = 0.0001). In the intent-to-treat analysis, 12% of patients in the OXC 2400 mg/day group were seizure-free compared with none in the 300 mg/day group. OXC was well-tolerated, with dizziness, fatigue, somnolence, and nausea being the most frequent AEs. Most of these AEs were transient and rated as mild to moderate in intensity. CONCLUSION: OXC is safe and effective in the treatment of patients with partial epilepsy previously receiving treatment with other antiepileptic drugs. The results of this trial are consistent with previous monotherapy trials with OXC.

Adjunctive therapy with oxcarbazepine in children with partial seizures. The Oxcarbazepine Pediatric Study Group.

OBJECTIVE: To evaluate the safety and efficacy of oxcarbazepine (OXC) as adjunctive therapy in children with inadequately controlled partial seizures on one or two concomitant antiepileptic drugs (AEDs). BACKGROUND: OXC has shown antiepileptic activity in several comparative monotherapy trials in newly diagnosed patients with epilepsy, and in a placebo-controlled monotherapy trial in hospitalized patients evaluated for epilepsy surgery. DESIGN: A total of 267 patients were evaluated in a multicenter, randomized, placebo-controlled trial consisting of three phases: 1) a 56-day baseline phase (patients maintained on their current AEDs); 2) a 112-day double-blind treatment phase (patients received either OXC 30-46 mg/kg/day orally or placebo); and 3) an open-label extension phase. Data are reported only from the double-blind treatment phase; the open-label extension phase is ongoing. METHODS: Children (3 to 17 years old) with inadequately controlled partial seizures (simple, complex, and partial seizures evolving to secondarily generalized seizures) were enrolled. RESULTS: Patients treated with OXC experienced a significantly greater median percent reduction from baseline in partial seizure frequency than patients treated with placebo (p = 0.0001; 35% versus 9%, respectively). Forty-one percent of patients treated with OXC experienced a > or =50% reduction from baseline in partial seizure frequency per 28 days compared with 22% of patients treated with placebo (p = 0.0005). Ninety-one percent of the group treated with OXC and 82% of the group treated with placebo reported > or =1 adverse event; vomiting, somnolence, dizziness, and nausea occurred more frequently (twofold or greater) in the group treated with OXC. CONCLUSION: OXC adjunctive therapy administered in a dose range of 6 to 51 mg/kg/day (median 31.4 mg/kg/day) is safe, effective, and well tolerated in children with partial seizures.

Oxcarbazepine: double-blind, randomized, placebo-control, monotherapy trial for partial seizures.

OBJECTIVE: To evaluate the efficacy and safety of oxcarbazepine in a placebo-control trial. METHODS: A multicenter, double-blind, randomized, placebo-control, two-arm parallel group, monotherapy design was used to compare oxcarbazepine administered 1,200 mg twice daily to placebo in hospitalized patients with refractory partial seizures, including simple and complex partial seizures and partial seizures evolving to secondarily generalized seizures. Patients exited the trial after completing the 10-day double-blind treatment phase or after experiencing four partial seizures, two new-onset secondarily generalized seizures, serial seizures, or status epilepticus, whichever came first. RESULTS: Analysis of the primary efficacy variable--time to meeting one of the exit criteria--showed a statistically significant effect in favor of oxcarbazepine (p = 0.0001). The secondary efficacy variables--percentage of patients who met one of the exit criteria (p = 0.0001) and total partial seizure frequency per 9 days during the double-blind treatment (p = 0.0001)--were also statistically significant in favor of oxcarbazepine. CONCLUSION: These results demonstrate that oxcarbazepine given as monotherapy is effective and safe for the treatment of partial seizures in this paradigm.

Clinical trials in cognitively impaired older adults: home versus clinic assessments.

OBJECTIVE: To compare the reliability of instruments used in clinical trials involving cognitively impaired older adults when the instruments are administered in-home rather than in-clinic and to compare withdrawal rates is these two groups. DESIGN: This study was part of a larger n-of-1 clinical trial to investigate the efficacy and safety of a MAO/A inhibitor (Brofaromine) in patients with Alzheimer's disease. Participants were initially assessed at the clinic (baseline) and then randomly allocated to in-home or in-clinic assessments for the remainder of the trial. The baseline and second assessment (performed before initiation of the treatment) were used for the reliability analysis. Withdrawal rates were examined over the course of the 6-month trial. SETTING: Assessments took place at a geriatric clinic in an urban university teaching hospital and at residences of some of the patients. PARTICIPANTS: Forty-six Alzheimer's disease patients participated in the study, of which, 22 were randomized to in-home assessments and 24 to in-clinic assessments. MEASUREMENTS: Test-retest reliability was measured for all five instruments used in the study and was based on the first two assessments. Sample size requirements, based on within-group variance, were calculated. Withdrawal rates were obtained for the total duration of the trial. RESULTS: Test-retest reliability of the instruments, as determined by intraclass correlations, was good in both groups but favored in-clinic for all but one instrument (range: 0.47-0.90 for in-home vs 0.57-0.92 for in-clinic). Sample size requirements based on reliability assessment data were found to be larger for some instruments when administered in-home. Only four in-home patients withdrew before completion of the study, compared with eight in-clinic patients. CONCLUSION: The results suggest the in-home assessments in cognitively impaired older adults may result in lower withdrawal rates but may necessitate larger sample sizes to offset larger test-retest variability.

Monoclonal evolution of angioimmunoblastic lymphadenopathy.

A patient with angioimmunoblastic lymphadenopathy diagnosed on initial lymph node biopsy was found on rebiopsy two months later to have immunoblastic lymphoma as well. At presentation she had polyclonal hypergammaglobulinemia with polyclonal (kappa and lambda light chains) immunoblasts demonstrated by the immunoperoxidase stain. During the course of her illness, a monoclonal IgM kappa gammaglobulinemia developed, accompanied by monoclonal (kappa light chains only) immunoblasts demonstrated by the immunoperoxidase method. These findings were unique in that lymphomatous transformation and clinical deterioration are shown to be accompanied by a monoclonal evolution of immunoblasts. This constitutes further evidence for the heterogeneous nature of patients who have angioimmunoblastic lymphadenopathy and the malignant potential of this disease.