Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study

BACKGROUND

No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge.

METHODS

The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing.

FINDINGS

2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7-9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46-0·99]), obesity (0·50 [0·34-0·74]) and invasive mechanical ventilation (0·42 [0·23-0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74-1·00]), at 5 months (0·74 [0·64-0·88]) to 1 year (0·75 [0·62-0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters.

INTERPRETATION

The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Radiogenomic analysis of primary breast cancer reveals [18F]-fluorodeoxglucose dynamic flux-constants are positively associated with immune pathways and outperform static uptake measures in associating with glucose metabolism

BACKGROUND

PET imaging of 18F-fluorodeoxygucose (FDG) is used widely for tumour staging and assessment of treatment response, but the biology associated with FDG uptake is still not fully elucidated. We therefore carried out gene set enrichment analyses (GSEA) of RNA sequencing data to find KEGG pathways associated with FDG uptake in primary breast cancers.

METHODS

Pre-treatment data were analysed from a window-of-opportunity study in which 30 patients underwent static and dynamic FDG-PET and tumour biopsy. Kinetic models were fitted to dynamic images, and GSEA was performed for enrichment scores reflecting Pearson and Spearman coefficients of correlations between gene expression and imaging.

RESULTS

A total of 38 pathways were associated with kinetic model flux-constants or static measures of FDG uptake, all positively. The associated pathways included glycolysis/gluconeogenesis ('GLYC-GLUC') which mediates FDG uptake and was associated with model flux-constants but not with static uptake measures, and 28 pathways related to immune-response or inflammation. More pathways, 32, were associated with the flux-constant K of the simple Patlak model than with any other imaging index. Numbers of pathways categorised as being associated with individual micro-parameters of the kinetic models were substantially fewer than numbers associated with flux-constants, and lay around levels expected by chance.

CONCLUSIONS

In pre-treatment images GLYC-GLUC was associated with FDG kinetic flux-constants including Patlak K, but not with static uptake measures. Immune-related pathways were associated with flux-constants and static uptake. Patlak K was associated with more pathways than were the flux-constants of more complex kinetic models. On the basis of these results Patlak analysis of dynamic FDG-PET scans is advantageous, compared to other kinetic analyses or static imaging, in studies seeking to infer tumour-to-tumour differences in biology from differences in imaging. Trial registration NCT01266486, December 24th 2010.

Parenchymal involvement on CT pulmonary angiography in SARS-CoV-2 Alpha variant infection and correlation of COVID-19 CT severity score with clinical disease severity and short-term prognosis in a UK cohort

AIM

To determine if there is a difference in radiological, biochemical, or clinical severity between patients infected with Alpha-variant SARS-CoV-2 compared with those infected with pre-existing strains, and to determine if the computed tomography (CT) severity score (CTSS) for COVID-19 pneumonitis correlates with clinical severity and can prognosticate outcomes.

MATERIALS AND METHODS

Blinded CTSS scoring was applied to 137 hospital patients who had undergone both CT pulmonary angiography (CTPA) and whole-genome sequencing of SARS-CoV-2 within 14 days of CTPA between 1/12/20–5/1/21.

RESULTS

There was no evidence of a difference in imaging severity on CTPA, viral load, clinical parameters of severity, or outcomes between Alpha and preceding variants. CTSS on CTPA strongly correlates with clinical and biochemical severity at the time of CTPA, and with patient outcomes. Classifying CTSS into a binary value of “high” and “low”, with a cut-off score of 14, patients with a high score have a significantly increased risk of deterioration, as defined by subsequent admission to critical care or death (multivariate hazard ratio [HR] 2.76, p<0.001), and hospital length of stay (17.4 versus 7.9 days, p<0.0001).

CONCLUSION

There was no evidence of a difference in radiological severity of Alpha variant infection compared with pre-existing strains. High CTSS applied to CTPA is associated with increased risk of COVID-19 severity and poorer clinical outcomes and may be of use particularly in settings where CT is not performed for diagnosis of COVID-19 but rather is used following clinical deterioration.

COVID-19 pneumonia imaging follow-up: when and how? A proposition from ESTI and ESR

Abstract

This document from the European Society of Thoracic Imaging (ESTI) and the European Society of Radiology (ESR) discusses the role of imaging in the long-term follow-up of COVID-19 patients, to define which patients may benefit from imaging, and what imaging modalities and protocols should be used. Insights into imaging features encountered on computed tomography (CT) scans and potential pitfalls are discussed and possible areas for future review and research are also included.

Key Points

• Post-COVID-19 pneumonia changes are mainly consistent with prior organizing pneumonia and are likely to disappear within 12 months of recovery from the acute infection in the majority of patients.

• At present, with the longest series of follow-up examinations reported not exceeding 12 months, the development of persistent or progressive fibrosis in at least some individuals cannot yet be excluded.

• Residual ground glass opacification may be associated with persisting bronchial dilatation and distortion, and might be termed “fibrotic-like changes” probably consistent with prior organizing pneumonia.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-021-08317-7.

Baseline PET/CT imaging parameters for prediction of treatment outcome in Hodgkin and diffuse large B cell lymphoma: a systematic review

Purpose

To systematically review the literature evaluating clinical utility of imaging metrics derived from baseline fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) for prediction of progression-free (PFS) and overall survival (OS) in patients with classical Hodgkin lymphoma (HL) and diffuse large B cell lymphoma (DLBCL).

Methods

A search of MEDLINE/PubMed, Web of Science, Cochrane, Scopus and clinicaltrials.gov databases was undertaken for articles evaluating PET/CT imaging metrics as outcome predictors in HL and DLBCL. PRISMA guidelines were followed. Risk of bias was assessed using the Quality in Prognosis Studies (QUIPS) tool.

Results

Forty-one articles were included (31 DLBCL, 10 HL). Significant predictive ability was reported in 5/20 DLBCL studies assessing SUVmax (PFS: HR 0.13–7.35, OS: HR 0.83–11.23), 17/19 assessing metabolic tumour volume (MTV) (PFS: HR 2.09–11.20, OS: HR 2.40–10.32) and 10/13 assessing total lesion glycolysis (TLG) (PFS: HR 1.078–11.21, OS: HR 2.40–4.82). Significant predictive ability was reported in 1/4 HL studies assessing SUVmax (HR not reported), 6/8 assessing MTV (PFS: HR 1.2–10.71, OS: HR 1.00–13.20) and 2/3 assessing TLG (HR not reported). There are 7/41 studies assessing the use of radiomics (4 DLBCL, 2 HL); 5/41 studies had internal validation and 2/41 included external validation. All studies had overall moderate or high risk of bias.

Conclusion

Most studies are retrospective, underpowered, heterogenous in their methodology and lack external validation of described models. Further work in protocol harmonisation, automated segmentation techniques and optimum performance cut-off is required to develop robust methodologies amenable for clinical utility.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00259-021-05233-2.

Artificial intelligence and radiomics in pulmonary nodule management: current status and future applications

Artificial intelligence (AI) has been present in some guise within the field of radiology for over 50 years. The first studies investigating computer-aided diagnosis in thoracic radiology date back to the 1960s, and in the subsequent years, the main application of these techniques has been the detection and classification of pulmonary nodules. In addition, there have been other less intensely researched applications, such as the diagnosis of interstitial lung disease, chronic obstructive pulmonary disease, and the detection of pulmonary emboli. Despite extensive literature on the use of convolutional neural networks in thoracic imaging over the last few decades, we are yet to see these systems in use in clinical practice. The article reviews current state-of-the-art applications of AI and in detection, classification, and follow-up of pulmonary nodules and how deep-learning techniques might influence these going forward. Finally, we postulate the impact of these advancements on the role of radiologists and the importance of radiologists in the development and evaluation of these techniques.

Reliability and validity of the World Health Organization reading standards for paediatric chest radiographs used in the field in an impact study of Pneumococcal Conjugate Vaccine in Kilifi, Kenya

BACKGROUND

Radiologically-confirmed pneumonia (RCP) is a specific end-point used in trials of Pneumococcal Conjugate Vaccine (PCV) to estimate vaccine efficacy. However, chest radiograph (CXR) interpretation varies within and between readers. We measured the repeatability and reliability of paediatric CXR interpretation using percent agreement and Cohen's Kappa and the validity of field readings against expert review in a study of the impact of PCV on pneumonia.

METHODS

CXRs were obtained from 2716 children admitted between 2006 and 2014 to Kilifi County Hospital, Kilifi, Kenya, with clinically-defined severe or very-severe pneumonia. Five clinicians and radiologists attended a three-day training course on CXR interpretation using a WHO standard. All CXRs were read once by two local primary readers. Discordant readings and 13% of concordant readings were arbitrated by a panel of three expert radiologists. To assess repeatability, a 5% median random sample was presented twice. Sensitivity and specificity of the primary readers' interpretations was estimated against the 'gold-standard' of the arbitrators' results.

RESULTS

Of 2716 CXRs, 2 were uninterpretable and 159 were evaluated twice. The percent agreement and Kappa for RCP were 89% and 0.68 and ranged between 84-97% and 0.19-0.68, respectively, for all pathological findings. Intra-observer repeatability was similar to inter-observer reliability. Sensitivities of the primary readers to detect RCP were 69% and 73%; specificities were 96% and 95%.

CONCLUSION

Intra- and inter-observer agreements on interpretations of radiologically-confirmed pneumonia are fair to good. Reasonable sensitivity and high specificity make radiologically-confirmed pneumonia, determined in the field, a suitable measure of relative vaccine effectiveness.

An aerosol challenge model of tuberculosis in Mauritian cynomolgus macaques

Background

New interventions for tuberculosis are urgently needed. Non-human primate (NHP) models provide the most relevant pre-clinical models of human disease and play a critical role in vaccine development. Models utilising Asian cynomolgus macaque populations are well established but the restricted genetic diversity of the Mauritian cynomolgus macaques may be of added value.

Methods

Mauritian cynomolgus macaques were exposed to a range of doses of M. tuberculosis delivered by aerosol, and the outcome was assessed using clinical, imaging and pathology-based measures.

Results

All macaques developed characteristic clinical signs and disease features of tuberculosis (TB). Disease burden and the ability to control disease were dependent on exposure dose. Mauritian cynomolgus macaques showed less variation in pulmonary disease burden and total gross pathology scores within exposure dose groups than either Indian rhesus macaques or Chinese cynomolgus macaques

Conclusions

The genetic homogeneity of Mauritian cynomolgus macaques makes them a potentially useful model of human tuberculosis.

A retrospective validation study of three models to estimate the probability of malignancy in patients with small pulmonary nodules from a tertiary oncology follow-up centre

AIM

To estimate the probability of malignancy in small pulmonary nodules (PNs) based on clinical and radiological characteristics in a non-screening population that includes patients with a prior history of malignancy using three validated models.

MATERIALS AND METHODS

Retrospective data on clinical and radiological characteristics was collected from the medical records of 702 patients (379 men, 323 women; range 19-94 years) with PNs ≤12 mm in diameter at a single centre. The final diagnosis was compared to the probability of malignancy calculated by one of three models (Mayo, VA, and McWilliams). Model accuracy was assessed by receiver operating characteristics (ROC). The models were calibrated by comparing predicted and observed rates of malignancy.

RESULTS

The area under the ROC curve (AUC) was highest for the McWilliams model (0.82; 95% confidence interval [CI]: 0.78-0.91) and lowest for the Mayo model (0.58; 95% CI: 0.55-0.59). The VA model had an AUC of (0.62; 95% CI: 0.47-0.64). Performance of the models was significantly lower than that in the published literature.

CONCLUSIONS

The accuracy of the three models is lower in a non-screening population with a high prevalence of prior malignancy compared to the papers that describe their development. To the authors' knowledge, this is the largest study to validate predictive models for PNs in a non-screening clinically referred patient population, and has potential implications for the implementation of predictive models.

Alternative BCG delivery strategies improve protection against Mycobacterium tuberculosis in non-human primates: Protection associated with mycobacterial antigen-specific CD4 effector memory T-cell populations

Intradermal (ID) BCG injection provides incomplete protection against TB in humans and experimental models. Alternative BCG vaccination strategies may improve protection in model species, including rhesus macaques. This study compares the immunogenicity and efficacy of BCG administered by ID and intravenous (IV) injection, or as an intratracheal mucosal boost (ID + IT), against aerosol challenge with Mycobacterium tuberculosis Erdman strain. Disease pathology was significantly reduced, and survival improved, by each BCG vaccination strategy, relative to unvaccinated animals. However, IV induced protection surpassed that achieved by all other routes, providing an opportunity to explore protective immunological mechanisms using antigen-specific IFN-γ ELISpot and polychromatic flow cytometry assays. IFN-γ spot forming units and multifunctional CD4 T-cell frequencies increased significantly following each vaccination regimen and were greatest following IV immunisation. Vaccine-induced multifunctional CD4 T-cells producing IFN-γ and TNF-α were associated with reduced disease pathology following subsequent M.tb challenge; however, high frequencies of this population following M.tb infection correlated with increased pathology. Cytokine producing T-cells primarily occupied the CD4 transitional effector memory phenotype, implicating this population as central to the mycobacterial response, potentially contributing to the stringent control observed in IV vaccinated animals. This study demonstrates the protective efficacy of IV BCG vaccination in rhesus macaques, offering a valuable tool for the interrogation of immunological mechanisms and potential correlates of protection.

Abstract A24: Integration of tumor metabolomics, cancer genome sequencing and dynamic functional imaging to assess the metabolic effects of metformin in breast cancer

There is great interest in the effects on cancer metabolism of the diabetes drug, metformin and its potential as a cancer treatment. Despite intense investigation it is still not clear as to its metabolic effects on primary human cancer in vivo. 41 patients with primary breast cancer were recruited to a ‘window of opportunity study’ prior to neoadjuvant chemotherapy. Before and after 2 weeks of metformin, dynamic 18F-FDG PET-CT scans were carried out, breast core biopsies of the primary tumour taken for RNASeq, metabolomics and immunohistochemistry analysis and host serum metabolic markers assessed.

Metabolomic mass spectrometry analysis revealed an increase in the ADP/ATP and AMP/ATP ratio (fold change 8.6 and 24.9, respectively, p = 0.07 and p = 0.14) after metformin treatment.

RNA sequencing of the first 21 paired samples showed upregulation of many genes encoding components of complex 1, and the TCA cycle, glutaminolysis, and glycolysis pathways. Several genes encoding for glucose and glutamine transport were amongst those most consistently upregulated, including GLUT1, SLC38A1 and SLC7A5 (all p&lt;0.0001).

Dynamic PET-CT analysis of the first 17 paired scans demonstrated a trend toward a decrease in the variable K2 post-metformin (an estimate of 18F-FDG efflux from tumour intracellular pool back to blood), but with much variability between paired scans (0.70±0.11 vs 0.51±0.05 (p=0.14)).

There was a decrease in serum C-peptide (0.56±0.04nmol/L vs 0.48±0.02nmol/L, pre- and post-metformin, p=0.003) consistent with reduced host insulin secretion. This is the first study in the clinical setting to show that metformin can cause an energy stress in cancer cells. The effect on mRNA expression was compatible with direct mitochondrial effects on the cancer cell leading to upregulation of the glutaminolysis and glycolysis pathways. The decrease in efflux of radiolabelled glucose may indicate retention of glucose possibly secondary to changes in blood glucose availability. We expect this study will help define biomarker development and future treatment strategies for metformin, in particular potential combination therapy.

Note: This abstract was not presented at the conference.

Citation Format: Simon R. Lord, Nilay Patel, D. Liu, J. Fenwick, C. Frezza, S. Henriques da Costa, E. Gaude, Q. Zhang, M. Wakelam, F. Gleeson, S. Haider, F. Buffa, A. L. Harris. Integration of tumor metabolomics, cancer genome sequencing and dynamic functional imaging to assess the metabolic effects of metformin in breast cancer [abstract]. In: Proceedings of the Thirteenth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2014 Sep 27-Oct 1; New Orleans, LA. Philadelphia (PA): AACR; Can Prev Res 2015;8(10 Suppl): Abstract nr A24.

Establishment of an aerosol challenge model of tuberculosis in rhesus macaques and an evaluation of endpoints for vaccine testing

The establishment of an aerosol challenge model in nonhuman primates (NHPs) for the testing of vaccines against Mycobacterium tuberculosis would assist the global effort to optimize novel vaccination strategies. The endpoints used in preclinical challenge studies to identify measures of disease burden need to be accurate and sensitive enough to distinguish subtle differences and benefits afforded by different tuberculosis (TB) vaccine regimens when group sizes are inevitably small. This study sought to assess clinical and nonclinical endpoints as potentially sensitive measures of disease burden in a challenge study with rhesus macaques by using a new protocol of aerosol administration of M. tuberculosis. Immunological and clinical readouts were assessed for utility in vaccine evaluation studies. This is the first example of TB vaccine evaluation with rhesus macaques where long-term survival was one of the primary endpoints. However, we found that in NHP vaccine efficacy studies with maximum group sizes of six animals, survival did not provide a valuable endpoint. Two approaches used in human clinical trials for the evaluation of the gamma interferon (IFN-gamma) response to vaccination (enzyme-linked immunospot [ELISpot] assay and enzyme-linked immunosorbent assay [ELISA]) were included in this study. The IFN-gamma profiles induced following vaccination were found not to correlate with protection, nor did the level of purified protein derivative (PPD)-specific proliferation. The only readout to reliably distinguish vaccinated and unvaccinated NHPs was the determination of lung lesion burden using magnetic resonance (MR) imaging combined with stereology at the end of the study. Therefore, the currently proposed key markers were not shown to correlate with protection, and only imaging offered a potentially reliable correlate.

Determination of lesion volume by MRI and stereology in a macaque model of tuberculosis

Sensitive and reproducible methods are needed to measure the impact on the host following experimental challenge with Mycobacterium tuberculosis, in order to determine the degree of protection conferred by new vaccines. Here we compare how well different clinical and post-mortem measures of disease burden predict the response by the host to increasing doses of M. tuberculosis in rhesus and cynomolgus macaques. The total lung and lesion volume was quantified from magnetic resonance imaging (MRI) digital stacks obtained from lungs of M. tuberculosis infected animals that were formalin fixed and scanned ex-vivo. The total lung lesion volume relative to the fixed whole lung volume was superior at indicating disease burden when compared to thoracic radiography, pathology scores, changes in body weight and temperature, as well as erythrocyte haemoglobin concentrations and sedimentation rate. The total lesion volume accurately reflected differences in challenge doses of M. tuberculosis that ranged from 30 to 500 CFU delivered by aerosol. The determination of total lesion volume from MR images demonstrated a species-dependent difference between rhesus and cynomolgus macaques in susceptibility to M. tuberculosis infection. MR stereology provides an accurate, quantifiable and relatively simple assessment, which can be easily standardized between laboratories and should form an essential component of the clinical assessment of disease progression, or vaccine efficacy.

Routine mobilization of the splenic flexure is not necessary during anterior resection for rectal cancer

PURPOSE

Splenic flexure mobilization is widely considered to be an essential component of anterior resection for rectal cancer. It was our hypothesis that selective splenic flexure mobilization would reduce operative times without increasing morbidity or affecting cure.

METHODS

A total of 100 consecutive patients with rectal cancer (mean 8 (range, 4-15) cm from anal verge) who underwent anterior resection for cure between 1996 and 2002 had splenic flexure mobilization only as required to achieve a tension-free anastomosis. Operative time, postoperative morbidity, pathologic findings, and recurrence rates were recorded.

RESULTS

There were no clinicopathologic differences between those who had splenic flexure mobilization (n = 26) and those who did not (n = 74). Mean operative time in the splenic flexure mobilization group was longer, 167 (range, 130-200) minutes vs. 120 (range, 95-180) minutes in the nonmobilized group (P = 0.023). Mean length of specimen resected was longer in the splenic flexure mobilization group: 36 vs. 18 cm (P = 0.008). Anastomotic complications (4 percent), local recurrence (7 percent, median follow-up, 38 months), perioperative morbidity (32 percent) and mortality (2 percent), and survival did not differ between the two groups.

CONCLUSIONS

Routine splenic flexure mobilization is not required for safe anterior resection in patients with rectal cancer. Avoiding splenic flexure mobilization results in shorter operative times and does not increase postoperative morbidity, anastomotic leakage, or local recurrence.

Endoscopic retrograde cholangiopancreatography catheter and accessory exchange using a short hydrophilic guide wire: a prospective study

BACKGROUND AND STUDY AIMS

Although hydrophilic guide wires can be used to facilitate stricture cannulation during endoscopic retrograde cholangiopancreatography (ERCP), some endoscopists avoid using them because of concerns about wire loss during exchange. There are no data available on the outcomes of using a short hydrophilic guide wire during ERCP. The aim of this study was to assess the outcomes of therapeutic ERCP procedures in which a short, completely hydrophilic guide wire was used exclusively.

PATIENTS AND METHODS

A total of 100 patients undergoing ERCP were studied prospectively. A 0.035-inch, 260-cm long, angled-tip hydrophilic wire (Terumo Glidewire) was used initially. Hydraulic catheter exchange was performed as follows: during catheter withdrawal the assistant advanced all the available wire into the catheter; a 12-ml syringe was then attached to the catheter and water was flushed under pressure to "float the wire" and maintain its position during catheter removal. Variables evaluated included exchange times and wire loss rates.

RESULTS

A total of 223 catheter exchanges were performed, 132 (59%) using the Olympus V-Scope (which held the wire in 62% of cases): 15% of exchanges were with catheters/accessories designed for short-wire use (Boston Scientific Rapid Exchange Biliary System or Rx System), and 85% were with a variety of standard-length accessories. Overall, the mean exchange time was 26 seconds (range 6 - 90 seconds, standard deviation 12 seconds). The mean exchange time was faster with the V-Scope and with non-Rx-System accessories. Wire loss occurred in 5 % of all exchanges. Desired ductal/stricture access was achieved in all the patients.

CONCLUSIONS

Exchange of short hydrophilic wires is quick and reliable. The Olympus V-Scope is able to hold the wire in some cases. Monorail-type devices and accessories slow catheter exchange down slightly because hydraulic exchange cannot be performed using these systems.

Outcome of accident and emergency room triaged patients with low risk non-variceal upper gastrointestinal haemorrhage

An acute upper gastrointestinal haemorrhage (UGIH) is an expensive healthcare problem estimated to cost more than 2.5 billion dollars per annum in the United States. Recent British Society of Gastroenterology (BSG) guidelines (2002) advise that patients with low risk non variceal UGIH have a benign outcome and may be suitable for a relatively short hospital stay with attendant economic saving. We evaluated current clinical experience, endoscopy findings and length of hospital stay in our hospital. We carried out a two year retrospective data analysis of 395 Accident and Emergency Room triaged patients admitted with a low risk non variceal UGIH. Data variables included age, sex, presence of co morbid illness, endoscopic findings, Rockall Risk Score, mortality within the hospitalisation period and length and cost of hospital stay. Of the 395 haemodynamically stable patients identified, requiring 1,644 hospitalisation days, 320/395 (85.8%) had a Rockall Score < or =3. No endoscopic intervention was required in 366/395 (92.7%) of patients with a 2% overall mortality. The mean hospital length of stay (LOS) was 4.16, costing in excess of 1002,840 Euro. Following routine clinical practice for low risk non variceal UGIH, the subsequent duration of hospital stay was unnecessarily prolonged and costly. This highlights the need to initiate change, to monitor resource utilisation and implement early hospital discharge in appropriate patients.

Juvenile hemochromatosis due to G320V/Q116X compound heterozygosity of hemojuvelin in an Irish patient

Hemojuvelin (HJV) is a recently discovered gene responsible for 1q-linked juvenile hemochromatosis. The majority of mutations characterized in this gene are rare and private, except G320V, identified in patients from different countries. Here, we report the clinical features and the molecular study of a young Irish patient presenting with severe cardiac disease related to iron overload. We sequenced the coding region and the exon-intron boundaries of genes associated with juvenile hemochromatosis, HAMP and HJV encoding hepcidin and hemojuvelin respectively. Two heterozygous HJV mutations were identified: the G320V mutation and the new Q116X mutation that cause a premature stop codon in the protein. This finding increases the number of mutations identified in HJV gene and underlines that the G320V is a recurrent mutation, even in Northern Europe.

Duodenal Dcytb and hephaestin mRNA expression are not significantly modulated by variations in body iron homeostasis

BACKGROUND AND AIMS

While the upregulation of duodenal cytochrome b (Dcytb) within duodenal enterocytes is reported in patients with iron deficiency, the expression of hephaestin (Hp) remains controversial in altered iron metabolism states, including HFE associated hereditary hemochromatosis (HH). The effect of iron depletion therapy on the expression of these molecules is unclear. This study examines the duodenal expression of these two molecules in HH patients (prior to and following phlebotomy), in patients with iron deficiency (ID) and in healthy controls.

METHODS

Using quantitative real-time polymerase chain reaction (qRT-PCR), Dcytb and Hp mRNA expression levels were measured in duodenal tissue of C282Y homozygous HH patients, in ID patients negative for the C282Y mutation with a serum ferritin concentration less than 20 mug/l, and in controls negative for C282Y and H63D mutations with normal iron indices.

RESULTS

Dcytb and Hp mRNA expression levels were not significantly different in either non-phlebotomized and phlebotomized HH patients or individuals with iron deficiency when compared with controls. There was no significant correlation between the gene expression levels and their respective serum ferritin or TS% values in any of the investigated groups. In HH patients, there was no significant association between gene expression and the degree of hepatic parenchymal siderosis identified by Perl's iron stain. Dcytb and Hp mRNA levels were significantly correlated to each other when all cohorts were analyzed together and separately.

CONCLUSIONS

These findings demonstrate that the duodenal ferroreductase Dcytb and ferroxidase Hp mRNA expression are not significantly altered by variations in iron homeostasis. The effect of phlebotomy-induced erythropoiesis did not alter either gene transcript mRNA expression.

Clinical expression of haemochromatosis in Irish C282Y homozygotes identified through family screening

BACKGROUND

In Ireland, the homozygote frequency of the C282Y mutation in the HFE gene is 1/83. The biochemical expression of this mutation is high in haemochromatosis (HH) individuals identified through family screening, but the clinical expression of the mutation in Irish HH subjects to date has not been investigated fully.

OBJECTIVES

To determine the clinical, biochemical and histological penetrance of the C282Y mutation in Irish C282Y homozygotes identified through family screening.

METHOD

Two hundred and nine C282Y homozygous individuals comprising of 172 first-degree relatives, 31 second-degree relatives and four unrelated individuals were identified following HFE mutation analysis of 167 families. The following variables were analysed: age at identification, gender, fasting transferrin saturation, fasting serum ferritin, liver enzymes, clinical symptomatology, liver histopathology and histochemical iron staining.

RESULTS

An elevated transferrin saturation in combination with an elevated ferritin was present in 43.4% of males and 23.3% of females. Abnormal liver enzymes were found in 32.3% of males. Diabetes, a haemochromatosis-specific association, was noted in 2.8% of males. Of those individuals requiring liver histopathology evaluation, 38% had moderate-to-severe iron staining, and 42% had fibrosis; 2.8% of the biopsied cohort had cirrhosis. Thus, HH cirrhotics were identified in less than 1% of the screened population.

CONCLUSION

Although the homozygote frequency in Ireland is very high, the prevalence of advanced liver disease was less than 1% of the family members screened. Nevertheless, 42% of biopsied patients had histological evidence of iron overload-related architectural change and 2.8% had cirrhosis. This cohort of young people had previously unrecognized biochemical iron overload and histopathological change. This emphasizes the importance and value of both genetic and biochemical screening in first-degree relatives of identified homozygotes.

Aetiology, outcome, and risk factors for mortality among adults with acute pneumonia in Kenya

BACKGROUND

Despite a substantial disease burden, there is little descriptive epidemiology of acute pneumonia in sub-Saharan Africa. We did this study to define the aetiology of acute pneumonia, to estimate mortality at convalescence, and to analyse mortality risk-factors.

METHODS

We studied 281 Kenyan adults who presented to two public hospitals (one urban and one rural) with acute radiologically confirmed pneumonia during 1994-96. We did blood and lung-aspirate cultures, mycobacterial cultures, serotype-specific pneumococcal antigen detection, and serology for viral and atypical agents.

FINDINGS

Aetiology was defined in 182 (65%) patients. Streptococcus pneumoniae was the most common causative agent, being found in 129 (46%) cases; Mycobacterium tuberculosis was found in 26 (9%). Of 255 patients followed up for at least 3 weeks, 25 (10%) died at a median age of 33 years. In multivariate analyses, risk or protective factors for mortality were age (odds ratio 1.51 per decade [95% CI 1.04-2.19]), unemployment (4.42 [1.21-16.1]), visiting a traditional healer (5.26 [1.67-16.5]), visiting a pharmacy (0.30 [0.10-0.91]), heart rate (1.64 per 10 beats [1.24-2.16]), and herpes labialis (15.4 [2.22-107]). HIV-1 seropositivity, found in 52%, was not associated with mortality. Death or failure to recover after 3 weeks was more common in patients with pneumococci of intermediate resistance to benzylpenicillin, which comprised 28% of pneumococcal isolates, than in those infected with susceptible pneumococci (5.60 [1.33-23.6]).

INTERPRETATION

We suggest that tuberculosis is a sufficiently common cause of acute pneumonia in Kenyan adults to justify routine sputum culture, and that treatment with benzylpenicillin remains appropriate for clinical failure due to M. tuberculosis, intermediate-resistant pneumococci, and other bacterial pathogens. However, interventions restricted to hospital management will fail to decrease mortality associated with socioeconomic, educational, and behavioural factors.

Onset of sucrase-isomaltase deficiency in late adulthood

Sucrase-isomaltase deficiency is a rare disorder usually manifested as diarrhea in infancy. The presentation of such a deficiency in adulthood is even more rare, particularly when the individual has no history of childhood diarrhea. After a literature search, the 59-yr-old patient we report is the oldest to have been identified with this condition. The difficulties encountered in diagnosis when such a case occurs at this age that have not previously been reported are highlighted.

Phase I study of intrapleural batimastat (BB-94), a matrix metalloproteinase inhibitor, in the treatment of malignant pleural effusions

Tumor cells and associated stromal cells secrete matrix metalloproteinases (MMPs), contributing to invasion, angiogenesis, and metastasis. Batimastat (BB-94) is a broad-spectrum MMP inhibitor that causes resolution of ascites and/or tumor growth delay in animal models of breast, ovarian, and colorectal cancer. We recruited 18 patients with cytologically positive malignant pleural effusions into a Phase I study of intrapleural BB-94. Three patients received single doses of BB-94 at each dose level: 15, 30, 60, 105, 135, and 300 mg/m2. Two patients were retreated with a second course at 60 and 105 mg/m2. BB-94 was detectable in plasma 1 h after intrapleural administration, and peak levels of 20-200 ng/ml occurred after 4 h to 1 week. BB-94 persisted in the plasma for up to 12 weeks, at levels exceeding the IC50s for target MMPs. Peak values were higher, and persistence in the plasma was longer after higher doses of BB-94. The treatment was well tolerated. Toxic effects included low-grade fever for 24-48 h (6 of 18 patients, 33%) and reversible asymptomatic elevation of liver enzymes (8 patients, 44%). Toxicity seemed unrelated to BB-94 dose or plasma levels. Sixteen patients evaluable for response required significantly fewer pleural aspirations in the 3 months after BB-94 compared with the 3 months before. Seven patients (44%) required no further pleural aspiration until death/last follow-up. After 1 month, patients treated with 60-300 mg/m2 BB-94 had significantly better dyspnea scores, indicating improved exercise tolerance, compared with baseline scores the day after BB-94. The maximum tolerated intrapleural dose remains to be defined, but it is clear that intrapleural BB-94 is well tolerated, with evidence of local activity.

Culture-amplified detection of dengue virus from serum in an outbreak of dengue fever

An outbreak of dengue type 2 occurred in North Queensland, Australia, between December 1996 and April 1997. Culture of serum in the Aedes albopictus C6/36 cell line with detection using immunofluorescent staining was compared with a culture-amplified detection system using an immunoperoxidase staining method in a microtiter plate format. A total of 374 serum specimens from individuals during the outbreak were tested. Ninety-five specimens were positive using immunofluorescence and ninety-two were positive using the immunoperoxidase method (sensitivity 91.6%; specificity 98.2%). The immunoperoxidase method is quicker, easier to perform, and does not require the use of an immunofluorescent microscope. The method is more suited to the processing of large numbers of specimens in an outbreak and could be used in endemic areas with limited virological resources.

Capturing discovery

The Canadian Medical Discoveries Fund offers Canadian researchers the capital and business expertise to protect and market new medical discoveries. The fund allows Canadians to capitalize upon their public investment in research by creating jobs and wealth. This generates confidence and investment in Canadian research and development, which will help to protect our healthcare system as a whole by demonstrating its value as a financial asset.

Review article: current indications for high resolution computed tomography scanning of the lungs

High resolution computed tomography (HRCT) is an effective technique for demonstrating the lung parenchyma in detail and overcomes many of the inadequacies of chest radiography in the diagnosis of diffuse lung disease. This article reviews the role of HRCT in the management of patients with chronic infiltrative lung disease, occupational lung disease, airways disease and acute and sub-acute lung disease.

Food and nutrient intakes and eating patterns in functional and organic dyspepsia

Forty organic dyspepsia patients and 40 functional dyspepsia patients, endoscopically diagnosed, were recruited from a gastroenterology outpatient unit and were age- and sex-matched with an equal number of patient controls. A diet history of typical eating patterns for a 7-day period was taken and food portions quantified using a photographic atlas. An interviewer-assisted questionnaire was used to identify present eating habits, dietary patterns reported to exacerbate or relieve symptoms and alterations in eating habits as a result of symptoms. Females with organic or functional dyspepsia reported significantly lower energy intakes (P < 0.01) than controls. Females with organic dyspepsia had significantly lower intakes of fat, carbohydrate, fibre and a wide range of micronutrients compared to controls. Females with functional dyspepsia had significantly lower intakes of fat, sugars and vitamin C (P < 0.05) than controls. Organic dyspepsia patients (male and female) had significantly lower intakes of alcohol and vitamin C than controls (P < 0.05). Patients with organic dyspepsia had higher intakes of milk and lower intakes of fresh fruit and/or fruit juice than controls. The main difference in eating pattern noted was that a significantly lower percentage (P < 0.05) of functional dyspepsia patients than controls regularly ate three meals per day. Large numbers of dyspepsia patients in both groups associated certain eating habits and the consumption of specific foods with exacerbation of dyspeptic symptoms and over 80% of both groups reported food avoidance as a result of this.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of irreversible image compression on diagnostic accuracy in thoracic imaging

RATIONALE AND OBJECTIVES

Digital image compression reduces the storage requirements and network traffic on picture archiving and communications systems. Full-frame bit-allocation (FFBA) is an irreversible image-compression method based on the discrete cosine transform that provides for high compression ratios with a high degree of image fidelity.

METHODS

One hundred twenty-two posteroanterior chest radiographs were obtained on patients in an ambulatory patient setting, including 30 cases of interstitial lung disease, 45 images containing combinations of lung nodules (N = 37) or mediastinal masses (N = 39), and 47 normal images containing none of the pathology for which we were testing. The images were digitized (nominal 2 K x 2 K x 12-bit resolution), printed on a 35 x 35-cm hard copy format, and compressed at an approximate compression ratio of 20:1. Observer performance tests were conducted with five radiologists using receiver operating characteristics analysis on digitized uncompressed and compressed hard copy images.

RESULTS

There were no significant differences between the two display conditions for the detectability of any of the thoracic abnormalities.

CONCLUSIONS

Our preliminary results suggest that irreversible image compression at ratios of 20:1 may be acceptable for use in digital thoracic imaging.