Immediate postoperative care on high dependency unit or ward following microvascular free tissue transfer: lessons learnt from a change in practice imposed during the COVID-19 pandemic

The COVID-19 pandemic resulted in sudden changes to the established practice of using the high dependency unit (HDU) for the first night of postoperative care following microvascular free tissue transfer. Patients were managed instead on the head and neck ward. This retrospective case-note review aimed to report outcomes in consecutive patients treated before and during the pandemic, and to reflect on the implications of ward-based rather than HDU care. A total of 235 patients had free tissue transfer between 3 January 2019 and 25 February 2021: 125 before (lockdown 23 March 2020), and 110 during the pandemic (52 ward-managed and 58 HDU-managed). There were subtle case-mix differences during the pandemic, with 92% of ward-treated patients having oral cancers compared with 64% of HDU patients, and 73% of ward patients having a tracheostomy compared with 40% of HDU patients. Ward patients were less likely to receive electrolyte replacement (45% HDU vs 0% ward) and inotropes (12% HDU vs 2% ward). There were fewer returns to theatre for evacuation of a haematoma or re-anastomosis during the pandemic than there were before it. Other than fewer haematoma complications during the pandemic, the nature of complications was similar. In conclusion, the dramatic changes imposed by the pandemic have shown that the ward is a safe place for patients to be cared for immediately postoperatively, and it alleviates the bed pressures experienced in HDU. Careful case selection and clear criteria are required to identify patients who need the HDU.

Outcomes of microvascular composite reconstruction for mandibular osteoradionecrosis

The aim of this retrospective study was to compare outcomes and reconstruction-related complications in patients receiving a composite free flap reconstruction of the mandible for ORN with those reconstructed for other indications. The records of all patients who underwent composite reconstruction of a mandibular defect at Aintree University Hospital, Liverpool, were reviewed and analysed. Based on radiotherapy exposure and ORN history, the study cohort was divided into three separate case-matched groups. Local wound healing issues were markedly more common in the ORN setting, as was infection and subsequent osteosynthesis plate(s) removal. Free flap survival was similar among all three case-matched groups. Advanced mandibular ORN may be safely and predictably reconstructed with composite free flaps, and that while the rate of local complications is greater than non-irradiated, and non-ORN case-matched controls, the free flap survival rate compares favourably.

Characteristics of a protocol to collect objective physical activity/sedentary behaviour data in a large study: Seniors USP (understanding sedentary patterns)

The Seniors USP study measured sedentary behaviour (activPAL3, 9 day wear) in older adults. The measurement protocol had three key characteristics: enabling 24-hour wear (monitor location, waterproofing); minimising data loss (reducing monitor failure, staff training, communication); and quality assurance (removal by researcher, confidence about wear). Two monitors were not returned; 91% (n=700) of returned monitors had 7 valid days of data. Sources of data loss included monitor failure (n=11), exclusion after quality assurance (n=5), early removal for skin irritation (n=8) or procedural errors (n=10). Objective measurement of physical activity and sedentary behaviour in large studies requires decisional trade-offs between data quantity (collecting representative data) and utility (derived outcomes that reflect actual behaviour).

Systematic comparative validation of self-report measures of sedentary time against an objective measure of postural sitting (activPAL)

BACKGROUND

Sedentary behaviour is a public health concern that requires surveillance and epidemiological research. For such large scale studies, self-report tools are a pragmatic measurement solution. A large number of self-report tools are currently in use, but few have been validated against an objective measure of sedentary time and there is no comparative information between tools to guide choice or to enable comparison between studies. The aim of this study was to provide a systematic comparison, generalisable to all tools, of the validity of self-report measures of sedentary time against a gold standard sedentary time objective monitor.

METHODS

Cross sectional data from three cohorts (N = 700) were used in this validation study. Eighteen self-report measures of sedentary time, based on the TAxonomy of Self-report SB Tools (TASST) framework, were compared against an objective measure of postural sitting (activPAL) to provide information, generalizable to all existing tools, on agreement and precision using Bland-Altman statistics, on criterion validity using Pearson correlation, and on data loss.

RESULTS

All self-report measures showed poor accuracy compared with the objective measure of sedentary time, with very wide limits of agreement and poor precision (random error > 2.5 h). Most tools under-reported total sedentary time and demonstrated low correlations with objective data. The type of assessment used by the tool, whether direct, proxy, or a composite measure, influenced the measurement characteristics. Proxy measures (TV time) and single item direct measures using a visual analogue scale to assess the proportion of the day spent sitting, showed the best combination of precision and data loss. The recall period (e.g. previous week) had little influence on measurement characteristics.

CONCLUSION

Self-report measures of sedentary time result in large bias, poor precision and low correlation with an objective measure of sedentary time. Choice of tool depends on the research context, design and question. Choice can be guided by this systematic comparative validation and, in the case of population surveillance, it recommends to use a visual analog scale and a 7 day recall period. Comparison between studies and improving population estimates of average sedentary time, is possible with the comparative correction factors provided.

SERPINE1 and SMA expression at the invasive front predict extracapsular spread and survival in oral squamous cell carcinoma

BACKGROUND

Extracapsular spread (ECS) in cervical lymph nodes is the single-most prognostic clinical variable in oral squamous cell carcinoma (OSCC), but diagnosis is possible only after histopathological examination. A promising biomarker in the primary tumour, alpha smooth muscle actin (SMA) has been shown to be highly prognostic, however, validated biomarkers to predict ECS prior to primary treatment are not yet available.

METHODS

In 102 OSCC cases, conventional imaging was compared with pTNM staging. SERPINE1, identified from expression microarray of primary tumours as a potential biomarker for ECS, was validated through mRNA expression, and by immunohistochemistry (IHC) on a tissue microarray from the same cohort. Similarly, expression of SMA was also compared with its association with ECS and survival. Expression was analysed separately in the tumour centre and advancing front; and prognostic capability determined using Kaplan-Meier survival analysis.

RESULTS

Immunohistochemistry indicated that both SERPINE1 and SMA expression at the tumour-advancing front were significantly associated with ECS (P<0.001). ECS was associated with expression of either or both proteins in all cases. SMA+/SERPINE1+ expression in combination was highly significantly associated with poor survival (P<0.001). MRI showed poor sensitivity for detection of nodal metastasis (56%) and ECS (7%). Both separately, and in combination, SERPINE1 and SMA were superior to MRI for the detection of ECS (sensitivity: SERPINE1: 95%; SMA: 82%; combination: 81%).

CONCLUSION

A combination of SMA and SERPINE1 IHC offer potential as prognostic biomarkers in OSCC. Our findings suggest that biomarkers at the invasive front are likely to be necessary in prediction of ECS or in therapeutic stratification.

Analysis of time taken to discuss new patients with head and neck cancer in multidisciplinary team meetings

Multidisciplinary team (MDT) meetings have an important role in the management of head and neck cancer. Increasing incidence of the disease and a drive towards centralised meetings on large numbers of patients mean that effective discussions are pertinent. We aimed to evaluate new cases within a single high volume head and neck cancer MDT and to explore the relation between the time taken to discuss each case, the number of discussants, and type of case. A total of 105 patients with a new diagnosis of head and neck malignancy or complex benign tumour were discussed at 10 head and neck cancer MDT meetings. A single observer timed each discussion using a stopwatch, and recorded the number of discussants and the diagnosis and characteristics of each patient. Timings ranged from 15 to 480 s (8 min) with a mean of 119 s (2 min), and the duration of discussion correlated closely with the number of discussants (rs=0.63, p<0.001). The longest discussions concerned patients with advanced T stage (p=0.006) and advanced N stage (p=0.009) disease, the elderly (p=0.02) and male patients (p=0.05). Tumour site and histological findings were not significant factors in the duration of discussion. Most discussions on patients with early stage tumours were short (T1: 58% less than 60s, mean 90) and fewer people contributed. Many patients, particularly those with early stage disease, require little discussion, and their treatment might reasonably be planned according to an agreed protocol, which would leave more time and resources for those that require greater multidisciplinary input. Further studies may highlight extended discussions on patients with head and neck cancer, which may prompt a review of protocols and current evidence.

Validation of a novel diagnostic standard in HPV-positive oropharyngeal squamous cell carcinoma

Background:

Human papillomavirus (HPV) testing in oropharyngeal squamous cell carcinoma (OPSCC) is now advocated. Demonstration of transcriptionally active high-risk HPV (HR-HPV) in fresh tumour tissue is considered to be the analytical ‘gold standard'. Clinical testing has focused on formalin-fixed paraffin-embedded (FFPE) tissue at the expense of sensitivity and specificity. Recently, a novel RNA in situ hybridisation test (RNAscope) has been developed for the detection of HR-HPV in FFPE tissue; however, validation against the ‘gold standard' has not been reported.

Methods:

A tissue microarray comprising FFPE cores from 79 OPSCC was tested using HR-HPV RNAscope. Analytical accuracy and prognostic capacity were established by comparison with the reference test; qRT–PCR for HR-HPV on matched fresh-frozen samples.

Results:

High-risk HPV RNAscope had a sensitivity and specificity of 97 and 93%, respectively, against the reference test. Kaplan–Meier estimates of disease-specific survival (DSS, P=0.001) and overall survival (OS, P<0.001) by RNAscope were similar to the reference test (DSS, P=0.003, OS, P<0.001) and at least, not inferior to p16 immunohistochemistry +/− HR-HPV DNA-based tests.

Conclusion:

HR-HPV RNAscope demonstrates excellent analytical and prognostic performance against the ‘gold standard'. These data suggest that the test could be developed to provide the ‘clinical standard' for assigning a diagnosis of HPV-related OPSCC.

P3-13-08: Survival Analysis and Recurrence Patterns in Locally Advanced Breast Cancer Following Neoadjuvant Chemotherapy and Preoperative Concurrent Chemo Radiotherapy

Introduction: Although not widely used, preoperative concurrent chemo radiotherapy (CCRth) following poor response to neo adjuvant chemotherapy (CT) has been recently associated with an improved prognosis in patients with locally advanced breast cancer (LABC) and high recurrence risk, showing acceptable toxicity profiles, acceptable post surgical complication rates and increases in both clinical and pathologic response rates and local control rates. The objective of this study was to assess disease free survival (DFS), overall survival (OS) and patterns of recurrence in a cohort of patients with LABC treated with pre operative CCRth following poor response to neo adjuvant CT.

Methods: This longitudinal study included a total of 287 patients with LABC treated with pre operative CCRth following poor response to neo adjuvant CT between February 2000 and December 2002. Demographic, clinical/pathologic, therapeutic and follow up data were collected from patient charts to determine DFS, OS and recurrence patterns.

Results: Stages IIB, IIIA and IIIB accounted for 22.3, 37.6 and 40% of the population, respectively. Clinical response rates compared to pathologic response rates following anthracyline based CT and CCRth were minimal or stable in 16% vs 62.4%, partial in 53 vs 76.3% and complete in 30 vs 23.3%. No significant treatment related toxicities were identified. Post surgical complications included flap ischemia in 16%, partial flap necrosis in 18%, both ischemia and partial flap necrosis in 13.2% and partial wound dehiscence in 7.7%. With an average follow up of 64.1 ± 37.2 months, (0-126.3 months), 36.9% of the population relapsed and 55.1% remained disease free. With regard to recurrence patterns, 22.6% presented loco regional relapse, 67.7% recurred at a distant site and 9.8% showed presented both. Median OS was 64.2 months (0-126 months). Five and ten year survival probability was shown to be 75% and 60%, respectively.

Conclusions Despite improvements in local control rates and overall outcomes with current therapeutic regimens combining chemotherapy, surgery, and radiotherapy, 30 to 40% of patients with locally advanced breast cancer develop post treatment loco regional recurrence and 5 year overall survival remains low (50%). Multimodal treatment integrating pre operative CCRth is therefore a valid alternative in the LABC setting, showing promising results in regard to OS, DFS and recurrence rates. Prospective clinical studies to evaluate its use are warranted.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-13-08.

Inter-rater reliability of the Pediatric Transplant Rating Instrument (P-TRI): challenges to reliably identifying adherence risk factors during pediatric pre-transplant evaluations

The purpose of this study was to assess the inter-rater reliability of the P-TRI, a 17-item instrument developed to identify risk factors associated with poor treatment adherence in pediatric solid organ transplant candidates. Because factors influencing treatment adherence may vary with age, the 89 subject samples were divided into pre-adolescent (0-11 yr) and adolescent (12-19 yr) groups. Each subject received two independent P-TRI ratings based on pretransplant psychosocial assessments separately conducted by a PSYC and a SWTC. Inter-rater reliability was assessed using the delta statistic. Overall, agreement was higher in the pre-adolescent group, with delta>0.70 for five items and delta<0.30 for two items. For the adolescent group, one item had a delta>0.70 and seven items had a delta<0.30. Overall, PSYC P-TRI ratings indicated fewer areas of concern on items assessing family dynamics compared with SWTC P-TRI ratings, whereas the reverse was true for items related to psychiatric history. Results highlight the challenges of conducting a reliable pretransplant assessment of adherence-related risk factors and suggest the need for revisions to the P-TRI prior to its use in clinical practice.

Identification of an abundant allergen from the sheep louse, Bovicola ovis

Infestation of sheep with the louse Bovicola ovis is common worldwide and leads to an allergic dermatitis referred to as 'scatter cockle'. IgE from an infested lamb was used in immunoaffinity chromatography to purify allergens from crude preparations of whole B. ovis and its faeces. SDS-PAGE of the affinity-purified eluates from both preparations showed a dominant band with M(r) of 28.5 kDa. Spleen cells from a mouse immunised with B. ovis faecal antigens were used to produce hybridomas which were screened by ELISA to identify those producing monoclonal antibodies (mAb) to the allergens purified by IgE immunoaffinity chromatography. Western blotting demonstrated that all of the mAbs examined recognised the 28.5 kDa allergen. The allergen, purified using immunoaffinity columns constructed with one of the specific mAbs, was shown to cause immediate and late-phase responses on intradermal skin testing in B. ovis-infested but not in naïve lambs. Levels of serum IgE specific for the purified allergen were significantly higher in infested than in naïve lambs (P < or = 0.0025). N-terminal and internal amino acid (aa) sequences obtained from the purified 28.5 kDa allergen were used to design primers to amplify a partial cDNA probe from B. ovis cDNA by PCR. The amplified probe was radiolabeled and used to screen a B. ovis cDNA library. The complete nucleotide sequence of the allergen was determined from the sequences of the positive clones from the library. The full-length cDNA encodes a 255 aa protein including a secretory leader sequence of 26 aas and a mature protein of 229 aas. The encoded protein showed strong homology to several hypothetical proteins of unknown function from diverse species and weak homology with lipid-binding proteins of Xenopus tropicalis and Galleria mellonella. This is the first allergen to be identified from a louse and it has been designated Bov o 1 in accordance with the criteria of the World Health Organization/International Union of Immunological Societies Allergen Nomenclature Subcommittee.

LKB1 and AMP-activated protein kinase control of mTOR signalling and growth

The AMP-activated serine/threonine protein kinase (AMPK) is a sensor of cellular energy status found in all eukaryotes that is activated under conditions of low intracellular ATP following stresses such as nutrient deprivation or hypoxia. In the past 5 years, work from a large number of laboratories has revealed that one of the major downstream signalling pathways regulated by AMPK is the mammalian target-of-rapamycin [mammalian target of rapamycin (mTOR) pathway]. Interestingly, like AMPK, the mTOR serine/threonine kinase plays key roles not only in growth control and cell proliferation but also in metabolism. Recent work has revealed that across eukaryotes mTOR orthologues are found in two biochemically distinct complexes and only one of those complexes (mTORC1 in mammals) is acutely sensitive to rapamycin and regulated by nutrients and AMPK. Many details of the molecular mechanism by which AMPK inhibits mTORC1 signalling have also been decoded in the past 5 years. AMPK directly phosphorylates at least two proteins to induce rapid suppression of mTORC1 activity, the TSC2 tumour suppressor and the critical mTORC1 binding subunit raptor. Here we explore the molecular connections between AMPK and mTOR signalling pathways and examine the physiological processes in which AMPK regulation of mTOR is critical for growth or metabolic control. The functional conservation of AMPK and TOR in all eukaryotes, and the sequence conservation around the AMPK phosphorylation sites in raptor across all eukaryotes examined suggest that this represents a fundamental cell growth module connecting nutrient status to the cell growth machinery. These findings have broad implications for the control of cell growth by nutrients in a number of cellular and organismal contexts.

Promoter methylation of P16, RARbeta, E-cadherin, cyclin A1 and cytoglobin in oral cancer: quantitative evaluation using pyrosequencing

Methylation profiling of cancer tissues has identified this mechanism as an important component of carcinogenesis. Epigenetic silencing of tumour suppressor genes through promoter methylation has been investigated by a variety of means, the most recent of which is pyrosequencing. We have investigated quantitative methylation status in oral squamous cell carcinoma patients. Fresh tumour tissue and normal control tissue from resection margin was obtained from 79 consecutive patients undergoing resection of oral squamous cell carcinoma. DNA was extracted and bisulphite treated. PCR primers were designed to amplify 75-200 bp regions of the CpG rich gene promoters of p16, RARbeta, E-cadherin, cytoglobin and cyclinA1. Methylation status of 4-5 CpG sites per gene was determined by pyrosequencing. Significant CpG methylation of gene promoters within tumour specimens was found in 28% for p16, 73% for RARbeta, 42% for E-cadherin, 65% for cytoglobin and 53% for cyclinA1. Promoter methylation was significantly elevated in tumours compared to normal tissue for p16 (P = 0.048), cytoglobin (P = 0.002) and cyclin A1 (P = 0.001) but not in RARbeta (P = 0.088) or E-cadherin (P = 0.347). Concordant methylation was demonstrated in this tumour series (P = 0.03). Significant differences in degree of methylation of individual CpG sites were noted for all genes except RARbeta and these differences were in a characteristic pattern that was reproduced between tumour samples. Cyclin A1 promoter methylation showed an inverse trend with histological grade. Promoter methylation analysis using pyrosequencing reveals valuable quantitative data from several CpG sites. In contrast to qualitative data generated from methylation specific PCR, our data demonstrated p16 promoter methylation in a highly tumour specific pattern. Significant tumour specific methylation of cyclin A1 promoter was also seen. Cytoglobin is a novel candidate tumour suppressor gene highly methylated in upper aero-digestive tract squamous cancer.

The transfer of maternal IgE and other immunoglobulins specific for Trichostrongylus colubriformis larval excretory/secretory product to the neonatal lamb

The transference of immunoglobulins from six New Zealand Romney ewes to their lambs was examined. Immunoglobulin levels were determined in ewe plasma, colostrum and lamb plasma shortly after birth and before the lambs fed, in lamb plasma 2 days after birth, and lamb plasma, ewe plasma and milk 30 days after parturition. Levels of total IgE, and IgE, IgG1, IgG2, IgM, and IgA with specificity for Trichostronglus colubriformis third stage larval secretory/excretory products (TcL3E/S) were determined. Mean levels of total IgE were three times higher in colostrum than in parturient ewe plasma while only trace amounts were detected in milk at 30 days after birth (107.7, 34.3, and 0.2U ml(-1), respectively, differences between means P< or =0.01). Mean total IgE in lamb plasma rose from being undetectable before suckling to levels comparable to those of the ewes by 2 days after birth (21.7U ml(-1)) and then declined to low levels by 30 days (0.4U ml(-1)). Total IgE levels in lamb plasma were significantly correlated with levels in ewe plasma and colostrum (r=0.91, P< or =0.01; r=0.96, P< or =0.003, respectively). The transference of TcL3E/S-specific IgE, IgG1 and IgA was substantial with mean levels of these antibodies in lamb plasma at 2 days comparable to that in parturient ewe plasma (absorbance levels in lamb plasma of 0.283, 0.537, and 0.334, respectively). Proportionally less maternal IgM and IgG2 appeared to be transferred to the lambs (absorbance of 0.112 and 0.081, respectively). Levels of TcL3E/S-specific IgE and IgG1 in lamb plasma at 2 days were significantly correlated with levels in parturient ewe plasma and colostrum (r=0.89 and 0.82, 0.85 and 0.96; all P< or =0.05, respectively). These results indicate that IgE is concentrated in ewe colostrum and that substantial amounts of maternal IgE are transferred to lambs via colostrum. Further, the results suggest that humoral immunity against gastro-intestinal nematode parasites and potentially other parasites in colostrum-fed lambs may approximate that of the ewe. The implications of the transference of humoral immunity through colostrum in ruminants for the passive protection and the development of active immunity against parasites remains to be fully explored.

Total and nematode-specific IgE responses in intestinal lymph of genetically resistant and susceptible sheep during infection with Trichostrongylus colubriformis

Total and antigen-specific IgE responses in afferent (AIL) and efferent (EIL) intestinal lymph of sheep with a nematode resistant (R) or susceptible (S) genotype during challenge infection with the intestinal nematode parasite Trichostrongylus colubriformis were examined. Within each sheep line, lambs with a nematode naive or nematode field-primed pre-challenge status were used. Total IgE level in AIL and EIL was dependent on nematode infection and was further influenced by genotype or the immune phenotype (nematode immune mean FEC+/-SDM=77+/-179 or non-immune mean FEC+/-SDM=4016+/-4318) of the animal. During T. colubriformis challenge immune animals had higher levels of total IgE in lymph than non-immune sheep, R line sheep had higher concentrations of total IgE than S line sheep, and field-primed animals had higher total IgE levels than nematode naive animals. Concentrations of total IgE were consistently higher in AIL than EIL or serum and were higher in lymph draining the proximal than the distal jejunum demonstrating that polyclonal IgE in AIL was largely derived from the intestinal mucosa of the anatomical compartment where the nematodes reside. The consistently higher concentration of total IgE in AIL was dependent on phenotype or genotype and in S genotype sheep also on the pre-challenge status. Concentrations of nematode specific IgE were significantly higher in EIL than AIL indicating a preference for the production of IgE reacting with excretory secretory products of the infective T. colubriformis larvae in the regional lymph node.

Standards for gene therapy clinical trials based on pro-active risk assessment in a London NHS Teaching Hospital Trust

Conducting gene therapy clinical trials with genetically modified organisms as the vectors presents unique safety and infection control issues. The area is governed by a range of legislation and guidelines, some unique to this field, as well as those pertinent to any area of clinical work. The relevant regulations covering gene therapy using genetically modified vectors are reviewed and illustrated with the approach taken by a large teaching hospital NHS Trust. Key elements were Trust-wide communication and involvement of staff in a pro-active approach to risk management, with specific emphasis on staff training and engagement, waste management, audit and record keeping. This process has led to the development of proposed standards for clinical trials involving genetically modified micro-organisms.

Survival of a free flap after arterial disconnection at six days

We know of no definition of how long it takes for a free flap to develop its own independent blood supply from its recipient bed. In this case report, we describe survival of a free flap after loss of the arterial anastomosis at 6 days.

Changes in brain intracellular pH and membrane phospholipids on oxygen therapy in hypoxic patients with chronic obstructive pulmonary disease

Chronic hypoxia due to chronic obstructive pulmonary disease (COPD) constitutes a stress to cerebral metabolic homeostasis. Previous studies using phosphorus-31 magnetic resonance spectroscopy (31P MRS) have suggested that the brains of such patients utilize anaerobic glycolysis, which in neonatal, animal, and in vitro studies is associated with a protective intracellular alkalosis. To identify such a compensatory intracellular alkalosis in hypoxic COPD patients, in vivo cerebral 31P MRS was performed in eight patients and eight controls. The mean intracellular pH (pHi) in patients with COPD was similar to that of age-matched controls, but decreased in the patients with COPD by a mean pHi of 0.02 (p = 0.04), following supplemental oxygen. There was no change in cerebral pHi in normal subjects following oxygen administration. The broadband component of the MR spectrum increased in all the patients with COPD (p = 0.01), suggesting altered phospholipid membrane fluidity in the brain associated with the change in pHi following oxygen administration. The change in the broadband resonance was strongly correlated with the change in pHi (r = -0.68, p = 0.014). This study suggests that patients with COPD exhibit a compensatory change in pHi and abnormalities in cerebral membrane phospholipid conformation in the face of chronic hypoxia.

Immune rejection of Trichostrongylus colubriformis in sheep; a possible role for intestinal mucus antibody against an L3-specific surface antigen

Sheep that have been immunized by multiple truncated infections with the parasitic nematode Trichostrongylus colubriformis contain anti-larval activity in their intestinal mucus and high-speed mucus supernatants. This activity induces T. colubriformis L3 to clump in vitro and causes a significant reduction in larval establishment in naive sheep after infusion of larvae and mucus into the intestinal lumen via a duodenal cannula. In this report, we provide evidence that one factor contributing to the anti-larval activity of immune mucus is antibody against a 35-kDa L3-specific cuticular antigen. The anti-larval activity in mucus is > 100 kDa by membrane filtration, is heat labile and sensitive to either protease digestion or reduction with DTT. Immunoblotting showed that mucus and supernatants of ultracentrifuged mucus from immune sheep contained IgG1 and IgA antibodies that recognized predominantly a larval antigen with an estimated molecular weight of 35 kDa on SDS-PAGE. Antibodies eluted from the surface of washed larvae that had been incubated in immune mucus also reacted specifically with the 35 kDa antigen on blots of larval homogenate. Immunofluorescence and immunogold electron microscopy showed that the 35 kDa antigen is present on the epicuticle of L3 and is shed during the moult to L4. The antigen is not present in eggs, L1, L2, L4 or adult worms and is found only in extracts of sheaths and L3 before infection and up to 4 days after infection. We hypothesize that the binding of antibody to the larval surface prevents larvae from establishing at their preferred site, causing them to be eliminated from the intestine. Monoclonal antibody PAB-1 recognizes the 35 kDa T. colubriformis larval antigen and also cross-reacts with antigens of similar molecular weight on blots of L3 extracts of the parasitic nematodes Haemonchus contortus and Ostertagia circumcincta; and with a 22-kDa antigen on blots of L3 extracts from Cooperia curticei and Nematodirus spathiger. This indicates that an antigenically related surface antigen with immunizing potential is present on several nematode species and can be identified by mAb PAB-1. The 35 kDa T. colubriformis larval antigen and related molecules in other nematodes are potential novel targets for stimulating host-protective immunity against nematode infections.

The molecular epidemiology of tuberculosis in inner London

The study used DNA fingerprint typing (spoligotyping and Heminested-lnverse-PCR) of Mycobacterium tuberculosis from all culture-confirmed inner London patients over a 12-month period to describe transmission. The methodology was evaluated by comparison with standard IS6110 typing and by examining its ability to identify known household clusters of cases. Isolates sharing indistinguishable typing patterns using both techniques were defined as clustered. Clusters were investigated to identify epidemiological links. The methodology showed good discriminatory power and identified known household clusters of cases. Of 694 culture-confirmed cases, 563 (81%) were typed. Eleven (2%) were due to laboratory cross-contamination and were excluded. Of the remaining 552 isolates 148 (27%) were clustered. Multivariate analysis indicated that clustering was more common in those with pulmonary smear positive disease (P < 0.02); those born in the United Kingdom (P < 0.0003) and in patients living in south London (P = 0.02). There was also a trend towards clustering being more common in those not known to have HIV infection (P = 0.051). The results suggest that in inner London, recent local transmission makes an important contribution to notification rates.

The role of small airways in lung disease

The small airways constitute one of the least understood areas of the lungs. They play a role in many lung diseases, and small airway pathology results in significant morbidity New approaches to their evaluation may provide insights into this major area of lung disease. Asthma is well recognized as a disease of both large and small airways. Physiological and pathological evidence, from techniques such as post-mortem tissue histological analysis, induced sputum and transbronchial biopsies, has reinforced the concept of the involvement of the entire bronchial tree n the inflammatory process in asthma, In addition to describing the airway pathology in asthma, th s review focuses on the pathogenesis and role of small airway obstruction n other diseases, including chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF), sarcoidosis and obliterative bronchiolitis (OB). COPD is characterized by the presence of airflow obstruction resulting from lesions in the small airways. In addition, features compatible with small airways disease are common in IPF, sarcoidosis and OB. Recent advances in pulmonary imaging, such as high-resolution computed tomography (HRCT) and magnetic resonance imaging (MRI) with hyperpolarized 3He, have allowed non-invasive reproducible measurements of structure-function relationships to be made for the small airways. These techniques have great potential for diagnosing changes in small airway function and for assessing responses to treatment. New insights into the contribution of small airways to a range of lung diseases may lead to the development of therapies targeted at this part of the bronchial anatomy.

Genetic diversity among Mycobacterium bovis isolates: a preliminary study of strains from animal and human sources

Mycobacterium bovis has the broadest host range of species in the Mycobacterium tuberculosis complex and is responsible for disease in humans and diverse animal species. We report on genotypic differences at multiple loci among 13 isolates derived from a range of human and animal infections. All isolates were classified as M. bovis by phenotypic analysis but could be subdivided into five distinct genotypes based on polymorphisms at the pncA and oxyR loci, the status of the RD5 deletion region, and the spoligotype pattern. These findings suggest the existence of a spectrum of strains with genotypic characteristics between those of M. tuberculosis and M. bovis.

Enhanced antimycobacterial response to recombinant Mycobacterium bovis BCG expressing latency-associated peptide

With a view to exploring the role of transforming growth factor beta (TGF-beta) during mycobacterial infection, recombinant clones of bacillus Calmette-Guérin (BCG) were engineered to express the natural antagonist of TGF-beta, latency-activated peptide (LAP). Induction of TGF-beta activity was reduced when macrophages were infected with BCG expressing the LAP construct (LAP-BCG). There was a significant reduction in the growth of LAP-BCG in comparison to that of control BCG following intravenous infection in a mouse model. The enhanced control of mycobacterial replication was associated with an increase in the production of gamma interferon by splenocytes challenged during the acute stage of infection but with a diminished recall response assessed after 13 weeks. Organ weight and hydroxyproline content, representing tissue pathology, were also lower in mice infected with LAP-BCG. The results are consistent with the hypothesis that TGF-beta has a detrimental effect on mycobacterial immunity. While a reduction in TGF-beta activity augments the initial response to BCG vaccination, early bacterial clearance may adversely affect the induction of a long-term memory response by LAP-BCG.

The mere exposure effect in patients with schizophrenia

The mere exposure effect refers to the development of an emotional preference for previously unfamiliar material because of frequent exposure to that material. This study compared schizophrenia subjects (n = 20) to normal controls (n = 21) to determine whether implicit memory, as demonstrated by the mere exposure effect, was intact. Patients with schizophrenia demonstrated a normal preference for both verbal and visual materials seen earlier relative to novel materials, despite impaired performance on a recognition task for explicit memory using similar materials. Previous studies of schizophrenia subjects have shown a dissociation between implicit and explicit memory on verbal tasks. We found a similar dissociation demonstrated by normal functioning on an implicit memory task and impaired functioning on an explicit memory task. Potential implications of these findings are discussed with regard to treatment and rehabilitation.

The characterization of novel, dual ErbB-2/EGFR, tyrosine kinase inhibitors: potential therapy for cancer

The type I receptor tyrosine kinases constitute a family of transmembrane proteins involved in various aspects of cell growth and survival and have been implicated in the initiation and progression of several types of human malignancies. The best characterized of these proteins are the epidermal growth factor receptor (EGFR) and ErbB-2 (HER-2/neu). We have developed potent quinazoline and pyrido-[3,4-d]-pyrimidine small molecules that are dual inhibitors of ErbB-2 and EGFR. The compounds demonstrate potent in vitro inhibition of the ErbB-2 and EGFR kinase domains with IC(50)s <80 nM. Growth of ErbB-2- and EGFR-expressing tumor cell lines is inhibited at concentrations <0.5 microM. Selectivity for tumor cell growth inhibition versus normal human fibroblast growth inhibition ranges from 10- to >75-fold. Tumor growth in mouse s.c. xenograft models of the BT474 and HN5 cell lines is inhibited in a dose-responsive manner using oral doses of 10 and 30 mg/kg twice per day. In addition, the tested compounds caused a reduction of ErbB-2 and EGFR autophosphorylation in tumor fragments from these xenograft models. These data indicate that these compounds have potential use as therapy in the broad population of cancer patients overexpressing ErbB-2 and/or EGFR.

Emergency airway management in a case of lingual haematoma

A previously unreported cause of acute tongue swelling is presented and the airway issues discussed. Cases with different aetiology have been sporadically published however the consequent, and sometimes fatal, airway obstructions have been dealt with somewhat variably. The aetiogy of acute tongue swelling and modern emergency airway algorithms are discussed with reference to the literature.

Analysis of an essential requirement for the poly(A) binding protein function using cross-species complementation

Poly(A) binding protein (PABP) is an essential, well-conserved, multifunctional protein involved in translational initiation, mRNA biogenesis, and degradation [1--5]. We have used a cross-species complementation approach to address the nature of the essential requirement for PABP in yeast. The expression of Pab3p, a member of the Arabidopsis thaliana PABP multigene family, rescues the lethal phenotype associated with the loss of the yeast Pab1p. However, Pab3p neither protects the mRNA 5' cap from premature removal, nor does it support poly(A)-dependent translational initiation or the synergistic enhancement of translation by the poly(A) tail and 5' cap in yeast. However, Pab3p corrects the temporal lag prior to the entry of the mRNA into the degradation pathway characteristic of pab1 Delta yeast strains. Furthermore, this lag correction by Pab3p requires Pan3p, a subunit of poly(A) nuclease, an enzyme involved in the mRNA 3'-end processing. Importantly, the substitution of Pab3p for the yeast Pab1p is synthetically lethal with the PAN3 gene deletion. These results show that the function of PABP in mRNA biogenesis alone could be sufficient to support cell viability in yeast.

Aquaporins and the surgeon: cautionary tales

Nephrogenic diabetes insipidus (NDI) presents an uncommon but formidable clinical challenge in the surgical patient. Two recent cases of NDI with differing aetiology are presented. These cases and a review of the literature illustrate well the diagnosis, fluid and electrolyte imbalances seen and the strategy of treatment required in the post-operative setting. The central role of the recently discovered aquaporin channels in this condition is briefly outlined. Nephrogenic diabetes insipidus has a diverse aetiology and many of the hazards of the condition are peculiar to the surgical setting. The importance of management in a high dependency environment is highlighted.

The Nf2 tumor suppressor, merlin, functions in Rac-dependent signaling

Mutations in the neurofibromatosis type II (NF2) tumor suppressor predispose humans and mice to tumor development. The study of Nf2+/- mice has demonstrated an additional effect of Nf2 loss on tumor metastasis. The NF2-encoded protein, merlin, belongs to the ERM (ezrin, radixin, and moesin) family of cytoskeleton:membrane linkers. However, the molecular basis for the tumor- and metastasis- suppressing activity of merlin is unknown. We have now placed merlin in a signaling pathway downstream of the small GTPase Rac. Expression of activated Rac induces phosphorylation and decreased association of merlin with the cytoskeleton. Furthermore, merlin overexpression inhibits Rac-induced signaling in a phosphorylation-dependent manner. Finally, Nf2-/- cells exhibit characteristics of cells expressing activated alleles of Rac. These studies provide insight into the normal cellular function of merlin and how Nf2 mutation contributes to tumor initiation and progression.

Contribution of Th1 and Th2 cells to protection and pathology in experimental models of granulomatous lung disease

Mice that had received adoptive transfer of DO11.10 TCR transgenic T cells polarized toward a Th1 or a Th2 phenotype were challenged with Ag-coated beads or with recombinant Mycobacterium tuberculosis expressing the OVA determinant. The resulting bead-induced pulmonary granulomas reflected the phenotype of the adoptively transferred T cells, with the Th2 cells promoting a fibrotic reaction. Mice receiving Th1 cells mounted an epitope-specific protective response to challenge with recombinant M. tuberculosis. Th2 recipients were characterized by enhanced weight loss and lung fibrosis during acute high-dose infection. The combination of TCR transgenic T cells and epitope-tagged mycobacteria provides a novel experimental model for investigation of the pathogenesis of tuberculosis.

Linguistic analysis to assess medically related posttraumatic stress symptoms

The authors examined the presence of posttraumatic stress symptoms (PTSS) in 20 patients requiring ventilation after acute respiratory distress. The subjects completed a semistructured interview about their ventilation experience that was subject to content and linguistic analysis. Subjects also completed two self-report measures to assess PTSS and socioemotional adjustment. Subjects who endorsed PTSS were more likely to use a narrative style suggesting emotional involvement in their recall of the stressful event. The authors indicate that the presence of PTSS is a common consequence of traumatic medical experiences and that denial of distress may be an adaptive short-term coping strategy.

Prosody and lexical accuracy in flat affect schizophrenia

To test the hypothesis that flat affect in schizophrenia involves a motor-expressive deficiency, but not an emotional deficiency, we compared the acoustic properties of speech that are used to express emotion with the emotional content of the words. DSM-III-R schizophrenic patients were divided into flat (N=20) and non-flat affect (N=26) groups on the basis of rating-scale scores. Twenty normal subjects also were included. Subjects were recorded on audio tape as they described a happy and a sad experience for about 10 min. The recordings were analyzed acoustically for fluency and for two types of prosody: inflection and emphasis. Words from transcriptions of the recordings were sorted by content analysis software into psychologically meaningful categories; we compared 'pleasure' and 'distress' word categories. Patients with flat affect spoke with less inflection, and were less fluent. However, they were similar to the other groups in the rate at which they used 'pleasure' words to describe happy experiences and 'distress' words to describe sad experiences. The behavioral deficiency in flat affect appears to be restricted to reduced activity in communicative motor channels. Other aspects of emotion processing seem intact.

Increased cortisol: cortisone ratio in acute pulmonary tuberculosis

To evaluate a possible role for altered cortisol metabolism in mediating the immunoparesis associated with progressive tuberculosis (TB), we have studied the hypothalamic-pituitary-adrenal axis, and the activities of the 11beta-hydroxysteroid dehydrogenases (11-HSDs) that interconvert active cortisol and inactive cortisone. In active pulmonary tuberculosis (PTB), the ratio of cortisol/cortisone metabolites in 24-h urine showed a shift towards active cortisol (ratio, 1.19 +/- 0.1, n = 16 versus 0. 89 +/- 0.05 in cured pulmonary tuberculosis (CTB), n = 13, p < 0. 01; and 0.78 +/- 0.04 healthy volunteers (HV), n = 11, p < 0.005). Conversion of cortisone (administered as 25 mg orally) to cortisol in peripheral plasma was higher in PTB (peak 1,157 +/- 55 nM, n = 14 versus 862 +/- 50 nM in CTB, n = 10, p < 0.005, and 882 +/- 73 nM in HV, n = 10; p < 0.005). Cortisol/cortisone ratio was increased in bronchoalveolar lavage fluid in PTB (7.73 +/- 1.48, mean +/- SE, n = 13) compared with HV (4.05 +/- 0.38, n = 11, p < 0.05) but was not different in plasma (PTB, 3.25 +/- 0.68; HV, 4.01 +/- 0.92). Responses of plasma cortisol to dexamethasone, CRH stimulation, and multidose ACTH stimulation were not different. These data suggest that in pulmonary tuberculosis, central control of glucocorticoid production is normal but that peripheral metabolism, in particular in the lung, is deviated in favor of the active metabolite cortisol. This offers a possible mechanism to explain the immunoparesis observed in progressive pulmonary tuberculosis.

Poly(A) tail-dependent exonuclease AtRrp41p from Arabidopsis thaliana rescues 5.8 S rRNA processing and mRNA decay defects of the yeast ski6 mutant and is found in an exosome-sized complex in plant and yeast cells

Eukaryotic 3'-->5' exonucleolytic activities are essential for a wide variety of reactions of RNA maturation and metabolism, including processing of rRNA, small nuclear RNA, and small nucleolar RNA, and mRNA decay. Two related but distinct forms of a complex containing 10 3'-->5' exonucleases, the exosome, are found in yeast nucleus and cytoplasm, respectively, and related complexes exist in human cells. Here we report on the characterization of the AtRrp41p, an Arabidopsis thaliana homolog of the Saccharomyces cerevisiae exosome subunit Rrp41p (Ski6p). Purified recombinant AtRrp41p displays a processive phosphorolytic exonuclease activity and requires a single-stranded poly(A) tail on a substrate RNA as a "loading pad." The expression of the Arabidopsis RRP41 cDNA in yeast rescues the 5.8 S rRNA processing and 3'-->5' mRNA degradation defects of the yeast ski6-100 mutant. However, neither of these defects can explain the conditional lethal phenotype of the ski6-100 strain. Importantly, AtRrp41p shares additional function(s) with the yeast Rrp41p which are essential for cell viability because it also rescues the rrp41 (ski6) null mutant. AtRrp41p is found predominantly in a high molecular mass complex in Arabidopsis and in yeast cells, and it interacts in vitro with the yeast Rrp44p and Rrp4p exosome subunits, suggesting that it can participate in evolutionarily conserved interactions that could be essential for the integrity of the exosome complex.

Saccharomyces cerevisiae transcription elongation mutants are defective in PUR5 induction in response to nucleotide depletion

IMP dehydrogenase (IMPDH) is the rate-limiting enzyme in the de novo synthesis of guanine nucleotides. It is a target of therapeutically useful drugs and is implicated in the regulation of cell growth rate. In the yeast Saccharomyces cerevisiae, mutations in components of the RNA polymerase II (Pol II) transcription elongation machinery confer increased sensitivity to a drug that inhibits IMPDH, 6-azauracil (6AU), by a mechanism that is poorly understood. This phenotype is thought to reflect the need for an optimally functioning transcription machinery under conditions of lowered intracellular GTP levels. Here we show that in response to the application of IMPDH inhibitors such as 6AU, wild-type yeast strains induce transcription of PUR5, one of four genes encoding IMPDH-related enzymes. Yeast elongation mutants sensitive to 6AU, such as those with a disrupted gene encoding elongation factor SII or those containing amino acid substitutions in Pol II subunits, are defective in PUR5 induction. The inability to fully induce PUR5 correlates with mutations that effect transcription elongation since 6AU-sensitive strains deleted for genes not related to transcription elongation are competent to induce PUR5. DNA encompassing the PUR5 promoter and 5' untranslated region supports 6AU induction of a luciferase reporter gene in wild-type cells. Thus, yeast sense and respond to nucleotide depletion via a mechanism of transcriptional induction that restores nucleotides to levels required for normal growth. An optimally functioning elongation machinery is critical for this response.

Bronchopulmonary and mediastinal leishmaniasis: an unusual clinical presentation of Leishmania donovani infection

We describe a case of unusual leishmaniasis in a Sudanese man with a history of progressively enlarging granulomatous mediastinal lymphadenopathy, worsening hemoptysis, and an intense mucosal granulomatous inflammatory response in the large bronchi. Leishmania donovani DNA was detected in bronchial biopsies by polymerase chain reaction. This is a novel description of human leishmanial infection in an immunocompetent patient involving this anatomical site. The patient's condition improved clinically, spirometrically, and radiologically after a course of treatment with amphotericin B. The cell-mediated immune response was analyzed before, during, and after successful antileishmanial chemotherapy.

Tumour necrosis factor-alpha production in human alveolar macrophages: modulation by inhaled corticosteroid

Using an ex vivo alveolar macrophage model, the hypothesis that inhaled preparations of corticosteroids might have important anti-inflammatory effects on cells of the peripheral airway was tested. The tumour necrosis factor (TNF)-alpha-inducing potential of three glycolipid preparations from nonpathogenic (arabinofuranasyl lipoarabinomannan (LAM (Ara-LAM)) and virulent (mannase LAM (ManLAM)) mycobacteria and Gram-negative bacteria (lipopolysaccharide (LPS)), in primary alveolar macrophage preparations was investigated. A novel inhaled chlorofluorocarbon (CFC)-free preparation of beclomethasone dipropionate (hydrofluoroalkane 134a (HFA)-BDP) with increased peripheral lung deposition was investigated for its ability to modulate glycolipidinduced TNF-alpha production by human alveolar macrophages, in comparison with a CFC-containing preparation and placebo. Compared to the basal TNF-alpha bioactivity of 0.72 ng x mL-1 (geometric mean), the TNF-alpha bioactivity in the macrophage preparation increased following incubation with LPS (138 ng x mL-1, p<0.001), AraLAM (12.6 ng-mL-1, p<0.001) and ManLAM (1.42 ng x mL-1, p=0.02). HFA-BDP, administered in vivo, significantly reduced LPS- and ManLAM-induced TNF-alpha production by alveolar macrophages cultured ex vivo. No change in glycolipid-induced TNF-alpha production was observed following in vivo administration of CFC-BDP or HFA-placebo. This is the first demonstration of an immunomodulatory effect on alveolar cells of corticosteroid delivered via metered dose inhaler. The present findings suggest that alveolar deposition of beclomethasone dipropionate is capable of modulating the inflammatory potential of the alveolar macrophage population.