Brain proteomics supports the role of glutamate metabolism and suggests other metabolic alterations in protein l-isoaspartyl methyltransferase (PIMT)-knockout mice

Protein l-isoaspartyl methyltransferase (PIMT) repairs the isoaspartyl residues (isoAsp) that originate from asparagine deamidation and aspartic acid (Asp) isomerization to Asp residues. Deletion of the gene encoding PIMT in mice (Pcmt1) leads to isoAsp accumulation in all tissues measured, especially in the brain. These PIMT-knockout (PIMT-KO) mice have perturbed glutamate metabolism and die prematurely of epileptic seizures. To elucidate the role of PIMT further, brain proteomes of PIMT-KO mice and controls were analyzed. The isoAsp levels from two of the detected 67 isoAsp sites (residue 98 from calmodulin and 68 from glyceraldehyde-3-phosphate dehydrogenase) were quantified and found to be significantly increased in PIMT-KO mice (p < 0.01). Additionally, the abundance of at least 151 out of the 1017 quantified proteins was found to be altered in PIMT-KO mouse brains. Gene ontology analysis revealed that many down-regulated proteins are involved in cellular amino acid biosynthesis. For example, the serine synthesis pathway was suppressed, possibly leading to reduced serine production in PIMT-KO mice. Additionally, the abundances of enzymes in the glutamate-glutamine cycle were altered toward the accumulation of glutamate. These findings support the involvement of PIMT in glutamate metabolism and suggest that the absence of PIMT also affects other processes involving amino acid synthesis and metabolism.

A diagnostic dilemma: drug-induced aseptic meningitis in a 45-year-old HIV-positive man

We describe a case of aseptic meningitis following the administration of moxifloxacin in a 45-year-old man with human immunodeficiency virus (HIV). At presentation he was receiving tuberculosis treatment on a modified regimen following severe hepatotoxicity; this included moxifloxacin, started 8 days previously. Initial cerebrospinal fluid (CSF) analysis was grossly abnormal. Anti-viral and -bacterial treatments were started. All microbiological tests proved negative and his moxifloxacin was withheld resulting in a complete normalisation of CSF. Drug-induced aseptic meningitis is a diagnosis of exclusion and presents a serious diagnostic dilemma. The decision to withhold medication cannot be taken lightly.

MeV-energy x rays from inverse compton scattering with laser-wakefield accelerated electrons

We report the generation of MeV x rays using an undulator and accelerator that are both driven by the same 100-terawatt laser system. The laser pulse driving the accelerator and the scattering laser pulse are independently optimized to generate a high energy electron beam (>200  MeV) and maximize the output x-ray brightness. The total x-ray photon number was measured to be ∼1×10(7), the source size was 5  μm, and the beam divergence angle was ∼10  mrad. The x-ray photon energy, peaked at 1 MeV (reaching up to 4 MeV), exceeds the thresholds of fundamental nuclear processes (e.g., pair production and photodisintegration).

Quantum dots as phototoxic drugs and sensors of specific metabolic processes in living cells

When conjugated to CdSe/ZnS nanocrystals (quantum dots), the nucleobase adenine and the neurotransmitter dopamine quench fluorescence emission from in a manner strongly dependent upon the size of the quantum dot. The degree of quenching serves to predict the efficiency with which the conjugates are able to enter living cells. Along with quenching, the presence of specific receptors on the cells is necessary for QD binding, entry, and phototoxicity. Toxicity is manifested by opening of large membrane pores and by oxidative DNA damage, and does not require the release of Cd⁺². In bacterial cells, light exposure is necessary for uptake, and procedures to reduce toxicity eliminate labeling. In mammalian cells, antioxidants prevent toxicity but not QD uptake, leading to QD-loaded cells that are nonfluorescent before light exposure. These findings provide a general procedure for rational design of nanoparticle-based photosensitizing drugs and for "off-on" fluorescent labels.

Nineteenth century research on cell death

This paper reviews research on cell death in the 19th C. The first report of cell death was by Vogt in 1842, which was remarkably soon after the establishment of the cell theory by Schleiden and Schwann between 1838 and 1842. Initial studies on cell death, including that of Vogt, focused on its occurrence in metamorphosis (Vogt, 1842; Prévost and Lebert, 1844; Weismann, 1863-1866) or in blatant pathology (Virchow, 1858), but as histological techniques improved it was found to be involved in more subtle roles in numerous situations including endochondral ossification (Stieda, 1872), ovarian follicle atresia (Flemming, 1885), cell turnover (Nissen, 1886), the wholesale loss of a population of sensory neurons in fish (Beard, 1889), and the naturally occurring histogenetic death of myocytes (Felix, 1889) and neurons (Collin, 1906). The current categorization of cell death into about three main morphological types has 19th century roots in that apoptosis was well described by Flemming (1885), who called it chromatolysis, and various authors including Noetzel (1895) proposed a threefold classification. This article is part of a Special Issue entitled "Apoptosis: Four Decades Later".

Long-term neurological follow-up of HIV-positive patients diagnosed with syphilis

No cerebrospinal fluid (CSF) abnormalities are found in HIV-positive patients in long-term follow-up after standard syphilis treatment. Syphilis has been reported to have immunological effects on HIV infection and HIV is known to modulate both the manifestations of syphilis and the serological response to therapy. HIV-positive patients who had been diagnosed with and treated for syphilis prior to 2007 were identified. Patients were consented for lumbar puncture. Serum HIV viral load, CD4 count and CSF were recorded. Thirty-five patients with previously diagnosed and treated syphilis underwent lumbar puncture. Thirty-four patients had a normal neurological exam. Only one patient had an abnormal mean white cell count (10.7 cells per high-power field). The finding that those with previously diagnosed syphilis had normal CSF and clinical findings is reassuring and supports the practice of using standard syphilis therapy in HIV-positive patients.

A multi-centre randomized, open-label phase II trial of continuous erlotinib plus gemcitabine or gemcitabine as first-line therapy in ECOG PS2 patients with advanced non-small cell lung cancer

Erlotinib and gemcitabine are active in NSCLC and have synergy in other cancers. This study investigated the activity and tolerability of this combination as first-line therapy in ECOG PS 2 patients. Chemotherapy-naïve patients with NSCLC, either stage IIIB (with plural effusion) or stage IV, with measurable disease and ECOG PS 2, and adequate organ function were randomized to receive either erlotinib (150 mg/day p.o.) plus gemcitabine (1000 mg/m2, days 1, 8, 15, every 4 weeks) in Arm A or gemcitabine monotherapy (Arm B). The primary end-point was progression-free survival. Seventeen patients of a planned 120 patients were randomized (12 males; 16 Caucasians, 4 large cell, 9 adenocarcinoma; 13 former and 1 never smokers); 16 patients received treatment (8 in each arm). The incidence of treatment-related adverse events (AEs) was 8/8 in Arm A and 6/8 in Arm B; most AEs were grade 1 or 2. The most common treatment-related non-hematological AEs were grade 1 or 2 rash (7/8) and diarrhea (7/8) in Arm A. Two patients in Arm A had partial responses, with durations of 16 and 47 weeks, respectively. Overall disease control rate (N=15) was 86% in Arm A versus 50% for the control arm. Erlotinib plus gemcitabine for the treatment of ECOG 2 NSCLC patients warrants further investigation including intermittent erlotinib regimens.

Long-term outcomes of isolated liver transplantation for short bowel syndrome and intestinal failure-associated liver disease

BACKGROUND AND AIM

A select group of children with short bowel syndrome (SBS) and intestinal failure-associated liver disease (IFALD) fulfill the criteria for isolated liver transplantation (iLTx). Long-term results in this group of patients have not been reported.

METHODS

A retrospective study of the medical records of 8 survivors of 14 children who underwent iLTx for SBS and IFALD from 1998 to 2005, managed by a multidisciplinary intestinal rehabilitation team at our institution.

RESULTS

Median follow-up is 107.5 months (range 89-153 months). Five of 8 children were weaned from parenteral nutrition (PN) to enteral nutrition (EN) in a median of 10 months after iLTx (range 3-32 months). Three of 5 children were subsequently weaned from EN to full oral feeding in 13, 24, and 53 months after stopping PN, whereas the remaining 2 are still receiving EN 118 and 74 months after stopping PN. These 5 children maintain their weight median z scores with a median increase of 1.59 (range 1.24-1.79) compared with the pretransplant z score, whereas the height z scores show fluctuations through the years with a median change of 0.12 (range -0.29 to 0.36). The other 3 of 8 children developed progressive intestinal failure; 2 underwent isolated small bowel transplantation 112 and 84 months after iLTx and the third is receiving PN.

CONCLUSIONS

Children with SBS and IFALD who have the potential for adaptation in the residual bowel can undergo iLTx, but it is a treatment option to be exercised with extreme caution. These children need close follow-up with an experienced multidisciplinary team to monitor nutritional outcomes and may need consideration for transplant or nontransplant surgery in the long term.

Identification of factors influencing shark catch and mortality in the Marshall Islands tuna longline fishery and management implications

Recent average annual catches of sharks by tuna longline vessels fishing in the Republic of the Marshall Islands (RMI) are estimated to be between 1583 and 2274 t. Although 22 shark species have been recorded by the observer programme for this fishery, 80% of the annual catch comprises only five species: blue shark Prionace glauca, silky shark Carcharhinus falciformis, bigeye thresher shark Alopias superciliosus, pelagic thresher shark Alopias pelagicus and oceanic whitetip shark Carcharhinus longimanus. Wire leaders (i.e. branch lines or traces) were also used by nearly all observed vessels. Generalized additive model (GAM)-based analyses of catch rates indicated that P. glauca and A. superciliosus are caught in higher numbers when vessels fish in relatively cooler waters, at night, close to the full moon, when the 27° C thermocline is close to the surface and during El Niño conditions. In contrast, C. falciformis, A. pelagicus and C. longimanus are caught in higher numbers when shark lines are used (all three species) or hooks are set at a shallow depth (A. pelagicus and C. longimanus and, also, P. glauca). These findings are generally consistent with current knowledge of these species' habitat preferences, movement and distribution. The results of these analyses were combined with information pertaining to shark condition and fate upon capture to compare the likely effectiveness of a range of potential measures for reducing shark mortality in the longline fishery. Of the options considered, the most effective would be to combine measures that reduce the catch rate (e.g. restrictions on the use of wire leaders, shark baits and shark lines) with measures that increase survival rates after post-capture release (e.g. finning bans).

Malignant mesothelioma

Malignant mesothelioma (MM) is an aggressive tumour that commonly affects the mesothelial surfaces of the pleural and peritoneal cavities, and occasionally, the tunica vaginalis and the pericardium. Formerly a rare tumour, MM is increasing in incidence in Australia due to the heavy nationwide use of asbestos from 1940 until the 1980s. The incidence is expected to peak in Australia in the next decade, mirroring the long latency period between asbestos exposure and development of MM. Diagnosis of MM can be difficult. Definitive pathological diagnosis is required and it often requires an experienced pathologist to differentiate MM from other benign or malignant processes. Treatment of MM requires a multidisciplinary approach, regardless of palliative or curative intent. Treatment options, such as surgery, chemotherapy, radiotherapy and active symptom control or a combination of these, may be used. Further research is needed to advance the therapeutic options for MM, and strategies to realize personalisation of therapy through discovery of predictive markers. In the Australian society where asbestos contamination of the built environment is very high, education and stringent public health measures are required to prevent a second wave of increased MM incidence.

Resuscitation feedback and targeted education improves quality of pre-hospital resuscitation in Scotland

BACKGROUND

Out-of-hospital cardiac arrest (OHCA) is a leading cause of mortality and serious neurological morbidity in Europe. Recent studies have demonstrated the adverse physiological consequences of poor resuscitation technique and have shown that quality of cardiopulmonary resuscitation (CPR) is a critical determinant of outcome from OHCA. Telemetry of the defibrillator transthoracic impedance (TTI) trace can objectively measure quality of pre-hospital resuscitation. This study aims to analyse the impact of targeted resuscitation feedback and training on quality of pre-hospital resuscitation.

METHODS

Prospective, single centre, cohort study over 13 months (1st December 2009-31st December 2010). Baseline pre-hospital resuscitation data was gathered over a 3-month period. Modems (n=40) were fitted to defibrillators on ambulance vehicles. Following a resuscitation attempt, the event was sent via telemetry and the TTI trace analysed. Outcome measures were time spent performing chest compressions, compression rate, the interval required to deliver a defibrillator shock and use of automatic or manual cardiac rhythm analysis. Targeted resuscitation classes were introduced and all ambulance crews received feedback following a resuscitation attempt. Pre-hospital resuscitation quality pre and post intervention were compared.

RESULTS

111 resuscitation traces were analysed. Mean hands-on-chest time improved significantly following feedback and targeted resuscitation training (73.0% vs 79.3%, p=0.007). There was no significant change in compression rate during the study period. There was a significant reduction in median time-to-shock interval from 20.25s (IQR 15.50-25.50s) to 13.45 s (IQR 2.25-22.00 s) (p=0.006). Automatic rhythm recognition fell from 50% to 28.6% (p=0.03) following intervention.

CONCLUSION

Telemetry and analysis of the TTI trace following OHCA allows objective evaluation of the quality of pre-hospital resuscitation. Targeted resuscitation training and ambulance feedback improves the quality of pre-hospital resuscitation. Further studies are required to establish possible survival benefit from this technique.

XELOX vs FOLFOX-4 as first-line therapy for metastatic colorectal cancer: NO16966 updated results

Background:

We report updated overall survival (OS) data from study NO16966, which compared capecitabine plus oxaliplatin (XELOX) vs 5-fluorouracil/folinic acid plus oxaliplatin (FOLFOX4) as first-line therapy in metastatic colorectal cancer.

Methods:

NO16966 was a randomised, two-arm, non-inferiority, phase III comparison of XELOX vs FOLFOX4, which was subsequently amended to a 2 × 2 factorial design with further randomisation to bevacizumab or placebo. A planned follow-up exploratory analysis of OS was performed.

Results:

The intent-to-treat (ITT) population comprised 2034 patients (two-arm portion, n=634; 2 × 2 factorial portion, n=1400). For the whole NO16966 study population, median OS was 19.8 months in the pooled XELOX/XELOX-placebo/XELOX-bevacizumab arms vs 19.5 months in the pooled FOLFOX4/FOLFOX4-placebo/FOLFOX4-bevacizumab arms (hazard ratio 0.95 (97.5% CI 0.85–1.06)). In the pooled XELOX/XELOX-placebo arms, median OS was 19.0 vs 18.9 months in the pooled FOLFOX4/FOLFOX4-placebo arms (hazard ratio 0.95 (97.5% CI 0.83–1.09)). FOLFOX4 was associated with more grade 3/4 neutropenia/granulocytopenia and febrile neutropenia than XELOX, and XELOX with more grade 3 diarrhoea and grade 3 hand-foot syndrome than FOLFOX4.

Conclusion:

Updated survival data from study NO16966 show that XELOX is similar to FOLFOX4, confirming the primary analysis of progression-free survival. XELOX can be considered as a routine first-line treatment option for patients with metastatic colorectal cancer.