Use of antimicrobials for food animals in New Zealand: updated estimates to identify a baseline to measure targeted reductions

AIM

To describe the use of antimicrobial drugs for food animals in New Zealand, based on sales data reported to government for 2005-2018, to provide a baseline to determine the success of measures to reduce antimicrobial use for food animals and to compare usage to selected European countries.

METHODS

Data were sourced from official government and industry reports to update previous estimates of use (as amount sold) of antimicrobial products applied to animals in New Zealand. The data included antimicrobial sales and animal populations, weighted where appropriate by breed and age class. Antimicrobial use was estimated based on the amount of active ingredient sold, per kg of animal biomass standardised to the probable weight at time of treatment or lifetime average but not slaughter weight (population correction unit; PCU). New Zealand data for 2017 and 2018 were adjusted to account only for antimicrobials used for farm animals by discounting horticulture use, companion animal use and export.

RESULTS

Between 2014 and 2018 the estimated usage of antimicrobials in animals flattened to a 5-year rolling average of 10.40 mg/PCU. New data on use for companion animals and on exports of zinc bacitracin and tylosin, included previously in the gross New Zealand values, allow a more refined estimate of use of antimicrobials in food animals of 10.21 mg/PCU in 2018, the third lowest rate of use for countries reporting by the same methodology. The intensive industries of pigs and poultry combined use more than 500 mg/PCU whereas the extensive red meat and dairy industries use an estimated 6.25 mg/PCU. New Zealand uses proportionally more cephalosporins and macrolides, two of the critically important antimicrobial groups, when compared with European countries, but less quinolones. The most obvious difference is the extensive use of zinc bacitracin and tylosin fed to pigs and poultry in New Zealand but not in the European Union.

CONCLUSIONS

Use of antimicrobials in food animals has stabilised to a rate of approximately 10.2 mg/PCU. This baseline should be used by the animal health industry to measure future success in its efforts to reduce and make more refined use of antimicrobial drugs as New Zealand works to deliver the government's Antimicrobial Resistance Action Plan. High rates of use of zinc bacitracin and some critically important macrolides represent clear targets in attempts to reduce usage.

COMT polymorphism modulates the resting-state EEG alpha oscillatory response to acute nicotine in male non-smokers

Performance improvements in cognitive tasks requiring executive functions are evident with nicotinic acetylcholine receptor (nAChR) agonists, and activation of the underlying neural circuitry supporting these cognitive effects is thought to involve dopamine neurotransmission. As individual difference in response to nicotine may be related to a functional polymorphism in the gene encoding catechol-O-methyltransferase (COMT), an enzyme that strongly influences cortical dopamine metabolism, this study examined the modulatory effects of the COMT Val158Met polymorphism on the neural response to acute nicotine as measured with resting-state electroencephalographic (EEG) oscillations. In a sample of 62 healthy non-smoking adult males, a single dose (6 mg) of nicotine gum administered in a randomized, double-blind, placebo-controlled design was shown to affect α oscillatory activity, increasing power of upper α oscillations in frontocentral regions of Met/Met homozygotes and in parietal/occipital regions of Val/Met heterozygotes. Peak α frequency was also found to be faster with nicotine (vs. placebo) treatment in Val/Met heterozygotes, who exhibited a slower α frequency compared to Val/Val homozygotes. The data tentatively suggest that interindividual differences in brain α oscillations and their response to nicotinic agonist treatment are influenced by genetic mechanisms involving COMT.

Vascular remodelling in the pathogenesis of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive and irreversible fibrosing interstitial pneumonia of unknown aetiology that usually leads to respiratory failure and death within 5 years of diagnosis. Alveolar epithelial cell injury, disruption of alveolar capillary membrane integrity and abnormal vascular repair and remodelling have all been proposed as possible pathogenic mechanisms. This review summarizes our current knowledge of the abnormalities in vascular remodelling observed in IPF and highlights several of the cytokines thought to play a pathogenic role, which may ultimately prove to be future therapeutic targets.

Anorectal atresia with gross terminal colonic distension in Africa

Anorectal malformation (ARM) is a group of significant birth defects with geographic variation in incidence, individual phenotypes and regional geographic subtypes occurring in approximately 1:5,000 live births. Anorectal atresia with gross terminal colonic distension in the presence of an absent anal canal has also been known as 'pouch colon' which is mainly associated with the Indian subcontinent. Its prevalence is unknown but it is rare, possibly representing a fraction of 1 % of ARM. The problem seems to revolve around the gross terminal distension of the distal pouch which remains a significant surgical challenge to surgeons resulting in poorer postoperative continence in many instances.

AIM

This study set out to collate data on ARM patients with gross terminal distension of the distal pouch from Africa to evaluate its epidemiology and outcome in African patients.

METHODS

Fifteen African paediatric surgical centres (7 South African and 8 African centres) were polled on the occurrence of anorectal atresia with gross terminal distension of the terminal bowel, an ARM variant. Data included ethnic group, age, gender as well as the anatomical pathology, classification and presence or absence of associated anomalies.

RESULTS

Of 12 respondents, 8 (67 %) responded and sufficient data to classify and analyse were obtained from six of the eight positive replies (7 new cases). Abdominal X-ray showed a grossly dilated terminal portion of the colon in the presence of an imperforate anus. A colovesical fistula was observed in four (three males and one female cloaca). Three were associated with a colonic atresia, of which two were in the transverse colon and one in the sigmoid colon. Surgical corrective procedures were carried out in six, but one patient, with a cloaca, died prior to surgical correction.

CONCLUSIONS

In this survey of 15 African centres, we have attempted to document the occurrence and presentation of anorectal atresia with gross terminal distension in Africa and report seven additional new cases. A possible association with associated conditions like colonic atresia requires further investigation.

Effects of COMT genotype on sensory gating and its modulation by nicotine: Differences in low and high P50 suppressors

Elevated smoking rates seen in schizophrenia populations may be an attempt to correct neuropathologies associated with deficient nicotinic acetylcholine receptors and/or dopaminergic systems using exogenous nicotine. However, nicotine's effects on cognitive processing and sensory gating have been shown to be baseline-dependent. Evidence of a restorative effect on sensory gating deficits by nicotine-like agonists has been demonstrated, however, its underlying mechanisms in the context of dopamine dysregulation are unclear. Catechol-O-methyltransferase (COMT), a key dopamine regulator in the brain, contains a co-dominant allele in which a valine-to-methionine substitution causes variations in enzymatic activity leading to reduced synaptic dopamine levels in the Val/Val genotype. Using a randomized, double-blind, placebo-controlled design with 57 non-smokers, this study examined the effects of COMT genotype on sensory gating and its modulation by nicotine in low vs. high suppressors. The results were consistent with the hypothesis that increased dopamine resulting from nicotine stimulation or Met allelic activity would benefit gating in low suppressors and impair gating in high suppressors, and that this gating improvement with nicotine would be more evident in Val carriers who were low suppressors, while the gating impairment would be more evident in Met carriers who were high suppressors. These findings reaffirm the importance of baseline-dependency and suggest a subtle relationship between COMT genotype and baseline-stratified levels of sensory gating, which may help to explain the variability of cognitive abilities in schizophrenia populations.

The moderating role of the dopamine transporter 1 gene on P50 sensory gating and its modulation by nicotine

Although schizophrenia has been considered primarily a disease of dopaminergic neurotransmission, the role of dopamine in auditory sensory gating deficits in this disorder and their amelioration by smoking/nicotine is unclear. Hypothesizing that individual differences in striatal dopamine levels may moderate auditory gating and its modulation by nicotine, this preliminary study used the mid-latency (P50) auditory event-related potential (ERP) to examine the single dose (6 mg) effects of nicotine (vs. placebo) gum on sensory gating in 24 healthy nonsmokers varying in the genetic expression of the dopamine transporter (DAT). Consistent with an inverted-U relationship between dopamine level and the drug effects, individuals carrying the 9R (lower gene expression) allele, which is related to greater striatal dopamine levels, tended to evidence increased baseline gating compared to 10R (higher gene expression) allele carriers and showed a reduction in gating with acute nicotine. The present results may help to understand the link between excessive smoking and sensory gating deficits in schizophrenia and to explain the potential functional implications of genetic disposition on nicotinic treatment in schizophrenia.

Cytochrome P450-dependent metabolism of gefitinib

The in vitro metabolism of [(14)C]-gefitinib (1-3 microM) was investigated using human liver microsomes and a range of expressed human cytochrome P450 enzymes, with particular focus on the formation of O-desmethyl-gefitinib (M523595), the major metabolite observed in human plasma. High-performance liquid chromatography with ultraviolet light, radiochemical and mass spectral analysis, together with the availability of authentic standards, enabled quantification and structural identification of metabolites. On incubation with pooled human liver microsomes, [(14)C]-gefitinib underwent rapid and extensive metabolism to a number of metabolites, although M523595 was only a minor microsomal product. Formation of most metabolites was markedly decreased by ketoconazole, but M523595 production was inhibited only by quinidine. Gefitinib was metabolized extensively by expressed CYP3A4, producing a similar range of metabolites to liver microsomes, but M523595 was not formed. CYP1A2, 2C9 and 2C19 produced no measurable metabolism of gefitinib, while CYP3A5 produced a range of metabolites similar to CYP3A4, but to a much lower degree. In contrast, CYP2D6 catalysed rapid and extensive metabolism of gefitinib to M523595. While formation of M523595 was CYP2D6 mediated, the overall metabolism of gefitinib was dependent primarily on CYP3A4, and this was not obviously diminished in liver microsomes from CYP2D6 poor metabolizers.

Nicotine and smoker status moderate brain electric and mood activation induced by ketamine, an N-methyl-d-aspartate (NMDA) receptor antagonist

As the increased smoking prevalence in schizophrenics may be interpreted as an adaptive response to an underlying biological defect, investigations into nicotine's actions within N-methyl-d-aspartate (NMDA) antagonist drug models of schizophrenia may improve our understanding of the role of glutamatergic neurotransmission in initiating and maintaining nicotine dependence in this disorder. In this double-blind, placebo-controlled, randomized study, the electroencephalographic (EEG) and subjective response to a sub-psychotomimetic intravenous dose of the NMDA antagonist ketamine was examined in 20 regular smokers and 20 non-smokers pretreated with placebo or nicotine gum. Although nicotine increased EEG arousal, ketamine produced electrocerebral signs of brain activation (decreased slow wave power) and sedation (decreased fast wave power and frequency), which were not affected by nicotine pretreatment and were evident only in non-smokers. Ketamine increased a number of self-report indices of subjective arousal, some of which were attenuated and potentiated by nicotine in smokers and non-smokers, respectively. These findings suggest that long-term (evidenced by smoker vs. non-smoker comparisons) and short-term (acute) nicotine exposure may alter NMDA receptor-mediated arousal and mood systems in a way that promotes nicotine dependence in smokers, and addresses neurobiological deficiencies in smokers with schizophrenia.

Regulation of vascular endothelial growth factor bioactivity in patients with acute lung injury

BACKGROUND

Reduced bioactive vascular endothelial growth factor (VEGF) has been demonstrated in several inflammatory lung conditions including the acute respiratory distress syndrome (ARDS). sVEGFR-1, a soluble form of VEGF-1 receptor, is a potent natural inhibitor of VEGF. We hypothesised that sVEGFR-1 plays an important role in the regulation of the bioactivity of VEGF within the lung in patients with ARDS.

METHODS

Forty one patients with ARDS, 12 at risk of developing ARDS, and 16 normal controls were studied. Bioactive VEGF, total VEGF, and sVEGFR-1 were measured by ELISA in plasma and bronchoalveolar lavage (BAL) fluid. Reverse transcriptase polymerase chain reaction for sVEGFR-1 was performed on BAL cells.

RESULTS

sVEGFR-1 was detectable in the BAL fluid of 48% (20/41) of patients with early ARDS (1.4-54.8 ng/ml epithelial lining fluid (ELF)) compared with 8% (1/12) at risk patients (p = 0.017) and none of the normal controls (p = 0.002). By day 4 sVEGFR-1 was detectable in only 2/18 ARDS patients (p = 0.008). Patients with detectable sVEGFR-1 had lower ELF median (IQR) levels of bioactive VEGF than those without detectable sVEGFR-1 (1415.2 (474.9-3192) pg/ml v 4761 (1349-7596.6) pg/ml, median difference 3346 pg/ml (95% CI 305.1 to 14711.9), p = 0.016), but there was no difference in total VEGF levels. BAL cells expressed mRNA for sVEGFR-1 and produced sVEGFR-1 protein which increased following incubation with tumour necrosis factor alpha.

CONCLUSION

This study shows for the first time the presence of sVEGFR-1 in the BAL fluid of patients with ARDS. This may explain the presence of reduced bioactive VEGF in patients early in the course of ARDS.

Morphological and morphometric attributes of epididymal and testicular spermatozoa following surgical sperm retrieval for obstructive and nonobstructive azoospermia

Whilst the morphological (shape) and morphometric (sperm head size) attributes of ejaculated spermatozoa have been well studied, the morphological and morphometric qualities of testicular and epididymal spermatozoa retrieved from males with obstructive and nonobstructive azoospermia is much less documented. We wished to examine the effect of aetiology of azoospermia and site of retrieval on the attributes of retrieved spermatozoa. This was a prospective observational study of 30 consecutive successful sperm retrievals, six for nonobstructive azoospermia and 24 for obstructive, of which five were retrieved from the epididymis and the remainder from the testis. The proportion of morphologically normal testicular spermatozoa in patients with obstructive and nonobstructive azoospermia was not significantly different (7% versus 7.6%, P = 0.97). Testicular spermatozoa from males with obstructive azoospermia showed an increase in frequency of sperm with small heads [47/180 (26%) versus 97/909 (11%), P = 0.036] as well as small acrosome and increasing vacuole formation over nonobstructive spermatozoa. Similarly, there was a significant increase in tail deformities and decreases in tail lengths in sperm from males with nonobstructive azoospermia. Epididymal spermatozoa showed significantly greater proportion of morphologically normal spermatozoa than testicular (20% versus 13%, P = 0.001) as well as a significant increase in acrosome vacuoles. Furthermore, morphometrically epididymal spermatozoa displayed with smaller head length, width and area than testicular spermatozoa. Testicular spermatozoa from obstructive azoospermia displayed significantly less tail defects (35% versus 57%, P = 0.003) as well as significantly longer tail lengths (30.6 microm versus 10.7 microm). These morphological and morphometric differences between epididymal and testicular and obstructive and nonobstructive spermatozoa may represent part of the natural maturation process. There were no associations between any morphological or morphometric abnormality with any significant parameter in subsequent use in ICSI.

A novel precursor ion discovery method on a hybrid quadrupole orthogonal acceleration time-of-flight (Q-TOF) mass spectrometer for studying protein phosphorylation

A tandem quadrupole time-of-flight (Q-TOF) mass spectrometer has been programmed such that phosphorylated peptides can automatically be discovered and identified in a way similar to that of the use of precursor ion or neutral loss scanning, but without the need to scan the quadrupole mass filter. Instead, the method capitalizes on the innate capability of the Q-TOF to record mass spectra and product ion spectra quickly, with good sensitivity and with good mass accuracy. Alternate mass spectra, with and without fragmentation, are recorded at high and low collision energy with the quadrupole operating in wideband mode. The method of analysis is both compatible with and dependant on liquid chromatography for separation of complex mixtures. The method has been demonstrated by searching for the neutral loss of 98 Da (H3PO4) from phosphoserine and phosphothreonine residues, or for the phosphorylated immonium ion at m/z 216 from phosphotyrosine. The method also incorporates acquisition of the product ion spectrum from any candidate precursor ions, thereby allowing confirmation of the neutral loss or product ion and providing additional sequence information to assist identification of the protein and assign the site of phosphorylation.

The quality of life impact of dysphonia

Dysphonia can affect social life and employment, but formal studies of its general health impact are lacking. The aims of this study were (i) to compare self-rated general health status as measured by the SF-36 in a large cohort of dysphonic patients with those from normative groups; and (ii) to examine the differential impact of dysphonia on the various health status domains. The 163 dysphonic voice clinic attendees (38 men, 125 women) were drawn from recruits to a prospective trial of speech therapy efficacy. The Short-Form 36 (SF-36) scores were compared with published data on 744 age-matched healthy controls. Patients with dysphonia had significantly poorer self-reported health than the controls on all eight SF-36 subscales (limitation of physical activity P < 0.05; other seven, all P < 0.001, Student's t-test). We thus conclude that dysphonia in patients without obvious laryngeal disease has an adverse impact on all health status subscales as measured by the SF-36. The study provides further evidence for the inclusion quality of life measures in otolaryngology baseline and outcome assessments.

A method for the amidation of recombinant peptides expressed as intein fusion proteins in Escherichia coli

The increasing use of peptides as pharmaceutical agents, especially in the antiviral and anti-infective therapeutic areas, requires cost-effective production on a large scale. Many peptides need carboxy amidation for full activity or prolonged bioavailability. However, this modification is not possible in prokaryotes and must be done using recombinant enzymes or by expression in transgenic milk. Methods employing recombinant enzymes are appropriate for small-scale production, whereas transgenic milk expression is suitable for making complex disulfide-containing peptides required in large quantity. Here we describe a method for making amidated peptides using a modified self-cleaving vacuolar membrane ATPase (VMA) intein expression system. This system is suitable for making amidated peptides at a laboratory scale using readily available constructs and reagents. Further improvements are possible, such as reducing the size of the intein to improve the peptide yields (the VMA intein comprises 454 amino acids) and, if necessary, secreting the fusion protein to ensure correct N-terminal processing to the peptide. With such developments, this method could form the basis of a large-scale cost-effective system for the bulk production of amidated peptides without the use of recombinant enzymes or the need to cleave fusion proteins.

Is voice therapy an effective treatment for dysphonia? A randomised controlled trial

OBJECTIVES

To assess the overall efficacy of voice therapy for dysphonia.

DESIGN

Single blind randomised controlled trial.

SETTING

Outpatient clinic in a teaching hospital.

PARTICIPANTS

204 outpatients aged 17-87 with a primary symptom of persistent hoarseness for at least two months.

INTERVENTIONS

After baseline assessments, patients were randomised to six weeks of either voice therapy or no treatment. Assessments were repeated at six weeks on the 145 (71%) patients who continued to this stage and at 12-14 weeks on the 133 (65%) patients who completed the study. The assessments at the three time points for the 70 patients who completed treatment and the 63 patients in the group given no treatment were compared.

MAIN OUTCOME MEASURES

Ratings of laryngeal features, Buffalo voice profile, amplitude and pitch perturbation, voice profile questionnaire, hospital anxiety and depression scale, clinical interview schedule, SF-36.

RESULTS

Voice therapy improved voice quality as assessed by rating by patients (P=0.001) and rating by observer (P<0.001). The treatment effects for these two outcomes were 4.1 (95% confidence interval 1.7 to 6.6) points and 0.82 (0.50 to 1.13) points. Amplitude perturbation showed improvement at six weeks (P=0.005) but not on completion of the study. Patients with dysphonia had appreciable psychological distress and lower quality of life than controls, but voice therapy had no significant impact on either of these variables.

CONCLUSION

Voice therapy is effective in improving voice quality as assessed by self rated and observer rated methods.

Genetic predisposition and pathogenetic mechanisms of interstitial lung diseases of unknown origin

Understanding of the cellular and cytokine interactions associated with inflammation and fibrosis in interstitial lung diseases (ILDs) has increased substantially during the past few years. Presently, many agents are known to have the ability to induce ILDs, although only a small percentage of exposed individuals will develop the disease. In addition, the majority of ILDs are of unknown origin and many are labelled "idiopathic". Therefore, host susceptibility, genetic factors and, possibly, environmental cofactors may be important for the clinical expression of ILDs. The present review reports evidence of the genetic predisposition to develop ILDs of unknown origin, more specifically sarcoidosis, idiopathic pulmonary fibrosis (IPF), lymphangioleio-myomatosis and ILDs, in systemic sclerosis. For instance, for sarcoidosis and IPF several histocompatibility antigens have been associated with the development and/or the clinical presentation of the disease. Furthermore, there are also several types of ILD that are associated with inherited disorders, of which the tuberous sclerosis complex is only one example. This clearly indicates that pulmonary fibrosis can be influenced by genetic factors. Familial occurrence of sarcoidosis and IPF is also well known, although the exact modes of inheritance are debatable. Several studies have shown that extrinsic factors, such as single or multiple fibrosing agents, probably contribute to the development of clinical ILDs of unknown origin. It is probable that some of these studies deal with patients who do not have classical IPF, as recently defined by the American Thoracic Society (ATS)/European Respiratory Society (ERS) consensus. Therefore, the true role of these extrinsic factors in the development of IPF, or even sarcoidosis, remains speculative. With the help of animal studies and, more specifically, by using knock-out mice, it may be possible in the near future to unravel at least some of the genes that are responsible for the increased susceptibility of the development of interstitial lung diseases.

Terbinafine-induced hepatic dysfunction

A 41-year-old man developed severe hepatic dysfunction following a 3.5-week course of terbinafine (250 mg/day). He suffered marked pruritus, jaundice, malaise, anorexia and loin pain. Serum bilirubin rose to a peak value of 718 micromol/l with alkaline phosphatase at 569 U/l, alanine aminotransferase at 90 U/l, aspartate aminotransferase at 63 U/l and a prolonged prothrombin time of 21 s, unresponsive to vitamin K. Transjugular liver biopsy showed canalicular cholestasis consistent with a drug reaction. Symptoms resolved 11 months after drug cessation, with liver function tests returning to normal values after 15 months. This case represents the most severe cholestatic reaction reported to date, resulting in patient recovery without liver transplantation. A comprehensive literature review is provided.

Metallic cough and pyogenic liver abscess

The curious symptom of a metallic cough in association with a pyogenic hepatic abscess should heighten awareness of a fistula. We describe a 78-year-old female with severe diverticular disease, on long-term steroid treatment for polymyalgia rheumatica. She developed a pyogenic liver abscess, treated initially by antimicrobial therapy, and subsequently drained by ultrasound and computed tomography-guided percutaneous transhepatic pigtail catheterization. This was complicated by a fistulous communication between the abscess cavity and the bronchus, confirmed by radiology. After repeated attempts at drainage and antimicrobial therapy the abscess cavity, including the hepatobronchial fistula, resolved.

Regioselective palladium-catalyzed arylation of 2-furaldehyde

An efficient regioselective method for the direct arylation of 2-furaldehyde to provide a range of pi-diverse 5-aryl-2-formylfuran derivatives is described. The method employs functionalized aryl halides and a catalytic amount of palladium(II) chloride under relatively mild conditions.

DNA-bound transcription factor complexes analysed by mass-spectrometry: binding of novel proteins to the human c-fos SRE and related sequences

Transcription factors control eukaryotic polymerase II function by influencing the recruitment of multiprotein complexes to promoters and their subsequent integrated function. The complexity of the functional 'transcriptosome' has necessitated biochemical fractionation and subsequent protein sequencing on a grand scale to identify individual components. As a consequence, much is now known of the basal transcription complex. In contrast, less is known about the complexes formed at distal promoter elements. The c-fos SRE, for example, is known to bind Serum Response Factor (SRF) and ternary complex factors such as Elk-1. Their interaction with other factors at the SRE is implied but, to date, none have been identified. Here we describe the use of mass-spectrometric sequencing to identify six proteins, SRF, Elk-1 and four novel proteins, captured on SRE duplexes linked to magnetic beads. This approach is generally applicable to the characterisation of nucleic acid-bound protein complexes and the post-translational modification of their components.

Drinking and driving: explaining beverage-specific risks

OBJECTIVE

This study tested whether the association of beer drinking with drinking and driving is due to cultural norms or is an artifact arising from the demographic profile of beer drinkers (young and male), the drinking patterns of this subpopulation (frequent and heavy), and the venues in which they prefer to drink (bars and restaurants).

METHOD

Telephone survey data from six U.S. communities were used to establish the demographic characteristics of drinkers, their consumption patterns, beverage preferences, preferred drinking venues and self-reported drinking and driving rates. The survey completion rate was 64.6%. A total sample of 5,231 drinkers was divided into test and validity samples. After deletion of cases with missing data, the test sample included 2,275 drinkers, of whom 985 had driven after drinking.

RESULTS

Controlling for a broad set of covariates, the analyses showed that frequent consumers were more likely to drink outside the home, preferred beer and spirits to wine, and were more likely than others to drink and drive. Beverage preferences were not directly associated with drinking and driving. Beer drinkers, however, were from the subpopulation most likely to drink and drive: heavier drinking younger men, who prefer to drink at bars and restaurants.

CONCLUSIONS

These results suggest that the association of beer consumption with drinking-driving arises from the circumstances in which the subpopulation of beer drinkers more commonly find themselves (as a result of their efforts to maximize, within economic constraints, the social and amenity value of drinking), as opposed to any culturally induced disposition beer drinkers may have to drink and drive.

Cp50 of propofol with and without nitrous oxide 67%

The target concentration of propofol required to prevent response to surgical incision was determined in 60 unpremedicated ASA I or II patients, who breathed either oxygen-enriched air or nitrous oxide 67% in oxygen. Propofol was infused using a target-controlled infusion system incorporating the standard 'Diprifusor' pharmacokinetic model, with the target concentration for each patient decided by up/down sequential allocation. Presence or absence of movement in response to a groin incision was determined by the surgeon. The calculated blood concentration at which 50% of patients responded (Cp50calc), determined by probit analysis, was 6.8 micrograms ml-1 for patients who breathed oxygen-enriched air and 4.9 micrograms ml-1 for those who breathed nitrous oxide 67% in oxygen.

Anti-cytokine therapy in fibrosing alveolitis: where are we now?

Idiopathic pulmonary fibrosis (IPF) is a condition that has a poor prognosis, with a median survival of 4-5 years irrespective of treatment. Ziesche et al (N Engl J Med 1999, 341: 1264-1269) describe an open randomised trial of 18 patients with IPF, unresponsive to corticosteroid treatment at high dose. Nine patients were treated with continued corticosteroid and nine with prednisolone plus interferon-gamma 1b (IFN-gamma). Significant benefits in physiological parameters are reported in the IFN-gamma-treated group. An analysis of lung tissue by reverse-transcriptase-mediated polymerase chain reaction showed corresponding decreases in the transcription of transforming growth factor-beta1 and connective tissue growth factor. This is the first report of treatment showing efficacy in this disease, albeit in a very preliminary study, but the data should be viewed with caution. This study is discussed in the context of other published studies of treatment for IPF and the scientific rationale on which it was based.

Identification of proteins from one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis using electrospray quadrupole-time-of-flight tandem mass spectrometry

The potential of electrospray tandem mass spectrometry using a quadrupole-time-of-flight tandem mass spectrometer was evaluated for the identification of two unknown proteins from one-dimensional polyacrylamide gel electrophoresis (1-D-PAGE). Two proteins from cellular cultures of mammary epithelia were purified by 1D-PAGE. Their identification was achieved using peptide sequence tags generated by LC/Q-TOF-MS/MS, whereas MALDI-TOF mass mapping failed for these proteins obtained from simple 1D-PAGE separation.

Immunohistochemistry for hMLH1 and hMSH2: a practical test for DNA mismatch repair-deficient tumors

Inactivation of deoxyribonucleic acid (DNA) mismatch repair genes, most commonly human mutL homologue 1 (hMLH1) or human mutS homologue 2 (hMSH2), is a recently described alternate pathway in cancer development and progression. The resulting genetic instability is characterized by widespread somatic mutations in tumor DNA, and is termed high-frequency microsatellite instability (MSI-H). Although described in a variety of tumors, mismatch repair deficiency has been studied predominantly in colorectal carcinoma. Most MSI-H colorectal carcinomas are sporadic, but some occur in patients with hereditary nonpolyposis colorectal cancer (HNPCC), and are associated with germline mutations in mismatch repair genes. Until now, the identification of MSI-H cancers has required molecular testing. To evaluate the role of immunohistochemistry as a new screening tool for mismatch repair-deficient neoplasms, the authors studied the expression of hMLH1 and hMSH2, using commercially available monoclonal antibodies, in 72 formalin-fixed, paraffin-embedded tumors that had been tested previously for microsatellite instability. They compared immunohistochemical patterns of 38 MSI-H neoplasms, including 16 cases from HNPCC patients with known germline mutations in hMLH1 or hMSH2, with 34 neoplasms that did not show microsatellite instability. Thirty-seven of 38 MSI-H neoplasms were predicted to have a mismatch repair gene defect, as demonstrated by the absence of hMLH1 and/or hMSH2 expression. This included correspondence with all 16 cases with germline mutations. All 34 microsatellite-stable cancers had intact staining with both antibodies. These findings clearly demonstrate that immunohistochemistry can discriminate accurately between MSI-H and microsatellite-stable tumors, providing a practical new technique with important clinical and research applications.