Persistent symptoms following SARS-CoV-2 infection amongst children and young people: A meta-analysis of controlled and uncontrolled studies

BACKGROUND

Data on the long-term impact of SARS-CoV-2 infection in children and young people (CYP) are conflicting. We assessed evidence on long-term post-COVID symptoms in CYP examining prevalence, risk factors, type and duration.

METHODS

Systematic search of published and unpublished literature using 13 online databases between 01/12/2019 and 31/07/2021. Eligible studies reported CYP ≤19 years with confirmed or probable SARS-CoV-2 with any symptoms persisting beyond acute illness. Random effects meta-analyses estimated pooled risk difference in symptom prevalence (controlled studies only) and pooled prevalence (uncontrolled studies also included). Meta-regression examined study characteristics hypothesised to be associated with symptom prevalence. Prospectively registered: CRD42021233153.

FINDINGS

Twenty two of 3357 unique studies were eligible, including 23,141 CYP. Median duration of follow-up was 125 days (IQR 99-231). Pooled risk difference in post-COVID cases compared to controls (5 studies) were significantly higher for cognitive difficulties (3% (95% CI 1, 4)), headache (5% (1, 8)), loss of smell (8%, (2, 15)), sore throat (2% (1, 2)) and sore eyes (2% (1, 3)) but not abdominal pain, cough, fatigue, myalgia, insomnia, diarrhoea, fever, dizziness or dyspnoea. Pooled prevalence of symptoms in post-COVID participants in 17 studies ranged from 15% (diarrhoea) to 47% (fatigue). Age was associated with higher prevalence of all symptoms except cough. Higher study quality was associated with lower prevalence of all symptoms, except loss of smell and cognitive symptoms.

INTERPRETATION

The frequency of the majority of reported persistent symptoms was similar in SARS-CoV-2 positive cases and controls. This systematic review and meta-analysis highlights the critical importance of a control group in studies on CYP post SARS-CoV-2 infection.

A Sweetpotato Geranylgeranyl Pyrophosphate Synthase Gene, IbGGPS, Increases Carotenoid Content and Enhances Osmotic Stress Tolerance in Arabidopsis thaliana

Sweetpotato highly produces carotenoids in storage roots. In this study, a cDNA encoding geranylgeranyl phyrophosphate synthase (GGPS), named IbGGPS, was isolated from sweetpotato storage roots. Green fluorescent protein (GFP) was fused to the C-terminus of IbGGPS to obtain an IbGGPS-GFP fusion protein that was transiently expressed in both epidermal cells of onion and leaves of tobacco. Confocal microscopic analysis determined that the IbGGPS-GFP protein was localized to specific areas of the plasma membrane of onion and chloroplasts in tobacco leaves. The coding region of IbGGPS was cloned into a binary vector under the control of 35S promoter and then transformed into Arabidopsis thaliana to obtain transgenic plants. High performance liquid chromatography (HPLC) analysis showed a significant increase of total carotenoids in transgenic plants. The seeds of transgenic and wild-type plants were germinated on an agar medium supplemented with polyethylene glycol (PEG). Transgenic seedlings grew significantly longer roots than wild-type ones did. Further enzymatic analysis showed an increased activity of superoxide dismutase (SOD) in transgenic seedlings. In addition, the level of malondialdehyde (MDA) was reduced in transgenics. qRT-PCR analysis showed altered expressions of several genes involved in the carotenoid biosynthesis in transgenic plants. These data results indicate that IbGGPS is involved in the biosynthesis of carotenoids in sweetpotato storage roots and likely associated with tolerance to osmotic stress.

Sentinel node biopsy in papillary thyroid cancer--what is the potential?

PURPOSE

Sentinel node biopsy (SNB) may identify lymph node metastases in patients with papillary thyroid cancer (PTC), enabling selective application of central node dissection (CND). The aim of this study was to assess the feasibility of implementing SNB in patients undergoing thyroidectomy for a cytologically indeterminate/suspicious/malignant thyroid nodule and to determine the potential improvement in clinical outcomes and the costs associated with the SNB technique.

METHODS

The treatment strategies and clinical and pathological outcomes of two retrospective cohorts of patients who underwent preoperative thyroid FNA over a 5-year period in two different centres were studied. The potential for implementing the SNB technique and the benefits and costs associated with implementation were estimated.

RESULTS

In centre 1, in 819 adult patients who had thyroid fine-needle aspiration cytology, the final cytology was indeterminate, suspicious and diagnostic of malignancy in 113, 29 and 28 patients, respectively. One hundred eight patients were 'suitable' for SNB. Twenty-three of these patients had PTC, six of whom underwent CND. Of these six patients, node metastasis was absent in five--the cohort in whom prophylactic CND may have been avoided consequent to a negative 'sentinel node' biopsy. Morbidity attributable to CND may have been avoided in up to four patients over a 5-year period. Costs associated with implementation of SNB outweighed any potential savings. Analysis of 491 patients in centre 2 confirmed that the benefit of SNB in PTC was similarly limited; morbidity attributable to CND may have been avoided in up to seven patients over a 5-year period.

CONCLUSIONS

Even under ideal conditions (assuming 100 % node identification rate and 0 % false negative rate), the potential short- to medium-term benefit of sentinel node biopsy in patients with thyroid cancer in centres implementing a policy of selective or routine prophylactic CND is low.

TaNF-YB3 is involved in the regulation of photosynthesis genes in Triticum aestivum

Nuclear factor Y (NF-Y) transcription factor is a heterotrimer comprised of three subunits: NF-YA, NF-YB and NF-YC. Each of the three subunits in plants is encoded by multiple genes with differential expression profiles, implying the functional specialisation of NF-Y subunit members in plants. In this study, we investigated the roles of NF-YB members in the light-mediated regulation of photosynthesis genes. We identified two NF-YB members from Triticum aestivum (TaNF-YB3 & 7) which were markedly upregulated by light in the leaves and seedling shoots using quantitative RT-PCR. A genome-wide coexpression analysis of multiple Affymetrix Wheat Genome Array datasets revealed that TaNF-YB3-coexpressed transcripts were highly enriched with the Gene Ontology term photosynthesis. Transgenic wheat lines constitutively overexpressing TaNF-YB3 had a significant increase in the leaf chlorophyll content, photosynthesis rate and early growth rate. Quantitative RT-PCR analysis showed that the expression levels of a number of TaNF-YB3-coexpressed transcripts were elevated in the transgenic wheat lines. The mRNA level of TaGluTR encoding glutamyl-tRNA reductase, which catalyses the rate-limiting step of the chlorophyll biosynthesis pathway, was significantly increased in the leaves of the transgenic wheat. Significant increases in the expression level in the transgenic plant leaves were also observed for four photosynthetic apparatus genes encoding chlorophyll a/b-binding proteins (Lhca4 and Lhcb4) and photosystem I reaction centre subunits (subunit K and subunit N), as well as for a gene coding for chloroplast ATP synthase γ subunit. These results indicate that TaNF-YB3 is involved in the positive regulation of a number of photosynthesis genes in wheat.

How common is repeat sudden infant death syndrome?

Recurrence of sudden infant death syndrome (SIDS) is rare but may give rise to confusion and controversy because of the differential diagnoses of familial disease or covert homicide. We examine eight studies of recurrent SIDS published in English since 1970. These studies reported relative risks of recurrence, as compared with the population or with controls, ranging from 1.7 to 10.1. We assess the validity of the studies by three main criteria: accuracy of ascertainment, adequacy of investigation and matching of controls. We found that all the studies failed to meet these criteria, and we think that their flaws would have resulted mainly in overestimation of recurrence risk. We conclude that, although an increase in risk is probable on theoretical grounds, this risk cannot be quantified from the available evidence. We suggest that professionals should be cautious in their pronouncements on the chances of recurrence, and that parents who have lost a baby to SIDS can, with the exception of particularly vulnerable families, be reassured that the risk of recurrence is small.

Genome-wide identification and expression analysis of the NF-Y family of transcription factors in Triticum aestivum

Nuclear Factor Y (NF-Y) is a trimeric complex that binds to the CCAAT box, a ubiquitous eukaryotic promoter element. The three subunits NF-YA, NF-YB and NF-YC are represented by single genes in yeast and mammals. However, in model plant species (Arabidopsis and rice) multiple genes encode each subunit providing the impetus for the investigation of the NF-Y transcription factor family in wheat. A total of 37 NF-Y and Dr1 genes (10 NF-YA, 11 NF-YB, 14 NF-YC and 2 Dr1) in Triticum aestivum were identified in the global DNA databases by computational analysis in this study. Each of the wheat NF-Y subunit families could be further divided into 4-5 clades based on their conserved core region sequences. Several conserved motifs outside of the NF-Y core regions were also identified by comparison of NF-Y members from wheat, rice and Arabidopsis. Quantitative RT-PCR analysis revealed that some of the wheat NF-Y genes were expressed ubiquitously, while others were expressed in an organ-specific manner. In particular, each TaNF-Y subunit family had members that were expressed predominantly in the endosperm. The expression of nine NF-Y and two Dr1 genes in wheat leaves appeared to be responsive to drought stress. Three of these genes were up-regulated under drought conditions, indicating that these members of the NF-Y and Dr1 families are potentially involved in plant drought adaptation. The combined expression and phylogenetic analyses revealed that members within the same phylogenetic clade generally shared a similar expression profile. Organ-specific expression and differential response to drought indicate a plant-specific biological role for various members of this transcription factor family.

Developing critical mass and growing our own academics

Academic paediatrics is an exciting and rewarding career path but is not immune to the problems of recruitment and retention currently affecting most branches of medicine. The Modernising Medical Careers initiative, with its explicit academic training path, offers an unparalleled opportunity to develop novel schemes that promote recruitment and retention. Coordinated action is required to define, publicise and support the new academic training programmes and to attract the best trainees into them.

The occurrence of terminal ileal histological abnormalities in patients with coeliac disease

INTRODUCTION

Coeliac disease causes histological changes throughout the small bowel, but is often a proximal lesion. We wanted to assess whether terminal ileal histological abnormalities occurred more commonly in patients with coeliac disease and if specific assessment of intraepithelial lymphocytes increases the recognition of undiagnosed coeliac disease.

METHODS

Terminal ileal biopsies were prospectively examined over a 3-year period (April 2001-May 2004). Patients were included if they were found to have a synchronous duodenal biopsy that gave a new diagnosis of coeliac disease (n=20). Terminal ileal biopsies taken at colonoscopy during the same period were also examined from four groups of patients: coeliac disease established on a gluten-free diet but with persisting symptoms (n=25), inflammatory bowel disease (n=47), chronic diarrhoea (n=44) and polyp surveillance (n=47). All biopsies were graded according to the Marsh criteria and an intraepithelial lymphocytes count per 100 enterocytes was obtained.

RESULTS

There was only one patient from all five groups who had villous atrophy of the terminal ileal. This patient had a new diagnosis of coeliac disease. The mean intraepithelial lymphocytes count in the coeliac disease group was 23.7 intraepithelial lymphocytes/100 enterocytes. This was significantly higher than the control groups: coeliac disease on a gluten-free diet=17.5 (p<0.012), inflammatory bowel disease=12.3 (p<0.0001), diarrhoea=12.6 (p<0.0001) and polyp=13.7 (p<0.0002). Validating terminal ileal villous intraepithelial lymphocytes counts as a test for coeliac disease using an intraepithelial lymphocytes/100 enterocytes of >25 gives a sensitivity of 45% and a specificity of 97.8%.

CONCLUSION

Routinely quantifying terminal ileal intraepithelial lymphocytes may be of limited clinical value. However, subjective recognition of raised intraepithelial lymphocytes on a terminal ileal biopsy should alert the clinician to the possibility of coeliac disease.

Prognostic and predictive factors in endocrine tumours

This review encompasses the diagnostic features of malignancy, the routinely observable prognostic features and the prognostic and predictive features emerging from research techniques in the principal endocrine neoplasms: pancreatic and extrapancreatic endocrine cell tumours, thyroid and parathyroid neoplasia, adrenal cortical neoplasms and adrenal and extra-adrenal paragangliomas. While each endocrine tissue has its own set of diagnostic features for malignancy, and prognostic features once a diagnosis of malignancy has been established, there are a few common themes. For several endocrine neoplasms, definite recognition of malignancy can be difficult and may depend upon frank invasive or metastatic growth at presentation. Endocrine tissues are dynamic, with hyperplastic and regressive phenomena, some of which may mimic malignancy. Even when unequivocal features of malignancy are available for observation, their distribution in tissue may be very focal, necessitating thorough sampling. The accurate documentation of routinely observable histological features interpreted in the light of current literature has not been superseded by special techniques in the statement of diagnosis or prognosis in the vast majority of endocrine neoplasms.

Change of refractive state and eye size in children of birth weight less than 1701 g

AIMS

To determine the refractive status and ocular dimensions of a cohort of children at age 10-12 years with birth weight below 1701 g, and also the relation between the neonatal ophthalmic findings and subsequent refractive state.

METHODS

293 low birthweight children who had been examined in the neonatal period were assessed at 10-12 years of age. The examination consisted of autorefraction, keratometry, and A-scan. Results of right eyes were compared with published normative data.

RESULTS

293 of the birth cohort of 572 children consented to participate. The average mean spherical equivalent (MSE) in the low birthweight cohort was +0.691 dioptre, significantly higher than the control data (+0.30D, p = 0.02). The average change in MSE over the 10-12 year period was -1.00 dioptre (n = 256), but only 62.1% of cases showed a shift in refractive error of the appropriate magnitude and direction. The presence of any retinopathy of prematurity (ROP) increases the risk of developing anisometropia sixfold.

CONCLUSIONS

Low birth weight and ROP both significantly impact the refractive state in the long term. At age 10-12 years children born preterm have an increased prevalence of all refractive errors. In low birthweight children refractive state is relatively stable over the first decade of life with a shift towards myopia of 1 dioptre.

HER2 amplification status in breast cancer: a comparison between immunohistochemical staining and fluorescence in situ hybridisation using manual and automated quantitative image analysis scoring techniques

AIMS

To compare the results of breast cancer sections with HercepTesttrade mark immunohistochemistry (IHC) scores ranging from 0 to 3+ with fluorescence in situ hybridisation (FISH) for HER2 amplification. The HER2 digital scoring application of the Micrometastasis Detection System (MDS) was used, together with manual scoring of FISH and HercepTest, to determine whether this system provides an accurate alternative.

METHODS

Paraffin wax embedded sections were stained using HercepTest and analysed by eye and automated quantitative image analysis. FISH was performed using the PathVysion fluorescent probe and scored by eye and automated quantitative image analysis using MDS.

RESULTS

Of 114 cases, 26% were amplified by FISH, whereas only 18% scored 3+; 32% of IHC 2+ cases were amplified by FISH, and one showed borderline amplification. Six percent of IHC negative cases (0 or 1+) were amplified by FISH, and one showed borderline amplification. Of IHC 3+ cases, 10% were non-amplified by FISH. Classification discrepancies were seen in 18% of HercepTest cases scored by eye and using the MDS system. MDS was consistent with visual FISH scoring and correctly differentiated most ambiguous visual IHC scores.

CONCLUSIONS

FISH provides a more accurate and consistent scoring system for determining HER2 amplification than HercepTest. The MDS system provides a reliable, consistent alternative to visual IHC and FISH scoring. IHC is still a valuable technique to aid in identification of isolated or heterogeneous tumour populations for subsequent FISH analysis, and a combined FISH and HercepTest approach to all breast cancer cases may be the most efficient strategy.

Effect of soy protein-rich diet on renal function in young adults with insulin-dependent diabetes mellitus

BACKGROUND

Diabetic nephropathy is the most frequent cause of end-stage renal disease in the Western world. Dietary intake, including protein amount and type, seems to affect the progression of renal disease. This pilot study tested the hypothesis that substituting soy protein for animal protein in the diets of diabetics would help correct glomerular hyperfiltration.

METHODS

Twelve young adults (aged 29.9 +/- 2.4 years) with type 1 diabetes mellitus (duration of diabetes 15.1 +/- 2.3 years) and hyperfiltration (glomerular filtration rate, GFR > 120 ml/min/1.73 m2) completed a crossover, dietary intervention trial. After a four-week assessment of baseline characteristics and dietary habits, subjects were assigned to either a control or soy diet for eight weeks after which each subject was crossed over to the alternative diet for another eight-week period.

RESULTS

Mean GFR was significantly reduced (p < 0.02) after eight weeks on the soy diet (143 +/- 7.4 ml/min/1.73 m2) compared with baseline (159 +/- 7.7 ml/min/ 1.73 m2) and control diets (161 +/- 10.0 ml/min/1.73 m2). Urinary excretion of the soy isoflavones was significantly higher (p < 0.01) at the end of the soy diet (genistein 1,014.6 +/- 274.1 nmol/h, daidzein 2,645.1 +/- 989.6 nmol/h) compared with baseline (genistein 53.7 +/- 31.1 nmol/h, daidzein 151.1 +/- 74.1 nmol/h) and control diets (genistein 41.1 +/- 13.3 nmol/h, daidzein 127.5 +/- 54.0 nmol/h). The soy diet significantly reduced total and LDL cholesterol by 7% and 9%, respectively.

CONCLUSIONS

Implementation of a soy-based diet appears to reduce the GFR and total and LDL cholesterol of young adults with type 1 diabetes and glomerular hyperfiltration, thus affecting positively their clinical profile.

Endoscopic ablation of Barrett's oesophagus: a randomized-controlled trial of photodynamic therapy vs. argon plasma coagulation

BACKGROUND

Barrett's oesophagus is the major risk factor for oesophageal adenocarcinoma. 5-Aminlevulinic acid-induced photodynamic therapy and argon plasma coagulation have been shown to be effective for ablating Barrett's oesophagus, but a comparative trial of these two modalities has not been reported.

AIMS

To compare photodynamic therapy and argon plasma coagulation for the ablation of Barrett's oesophagus.

METHODS

A total of 68 patients (54 male, 14 female; median age 61) with Barrett's oesophagus were randomized to photodynamic therapy (n = 34) or argon plasma coagulation (n = 34). Photodynamic therapy was performed using 5-aminlevulinic acid (30 mg/kg) and red light. Argon plasma coagulation was administered at a power setting of 65 W. Multiple treatment sessions were performed, with follow-up to 24 months.

RESULTS

All patients showed a macroscopic reduction in the area of Barrett's oesophagus. This was greatest in the argon plasma coagulation group with 33 of 34 (97%) ablated, compared with 17 of 34 (50%) in the photodynamic therapy group; in the remainder, there was a reduction in the length of Barrett's oesophagus (median 50%, range: 5-90). Buried glands were found in 24% of photodynamic therapy patients, and in 21% of argon plasma coagulation patients. The median follow-up is 12 months (range: 6-24).

CONCLUSIONS

Photodynamic therapy and argon plasma coagulation are both effective for ablating Barrett's oesophagus. Argon plasma coagulation appears more effective than photodynamic therapy, but the impact of both on carcinoma development requires larger studies with long-term follow-up.

Visual function in low birthweight children

AIM

To determine the visual functions, at age 10-12 years, of a geographically based cohort of children of birth weight less than 1701 g. The results were compared to a group of children born at full term.

METHODS

572 low birthweight (LBW) "low birthweight cohort" children who had been examined in the neonatal period were invited for review at 10-12 years of age. 169 11 year old schoolchildren born at full term were also recruited, "school cohort." Visual acuity (at distance and near), contrast sensitivity, colour vision, and visual fields were measured.

RESULTS

293 of the original 572 participants consented to a further examination. Compared to the school cohort of children born at term the low birthweight cohort showed significantly lower near and distance acuities and contrast sensitivity (p<0.001 for all uniocular and binocular measures). Retinopathy of prematurity (ROP) was a very poor predictor of outcome and multivariate analysis did not identify any key neonatal factors as predictors of long term visual outcome.

CONCLUSIONS

Low birthweight children have a small but statistically significant deficit in both visual acuity and contrast sensitivity. Low birth weight and ROP both impact on long term visual functions.

A comparison of findings on parents' and teachers' questionnaires, and detailed ophthalmic and psychological assessments

BACKGROUND

Questionnaires are important tools used to gain information about health and level of function in different domains.

AIMS AND METHODS

To determine the degree of agreement between questionnaires, administered to parents and teachers, and ophthalmic and psychological examinations in a cohort of 309 low birth weight children (<1701 g) at age 10-13 years.

RESULTS

A total of 90.9% of cases showed agreement between the question on distance vision and clinical assessment, and agreement for the near vision question was 83%. However, the correlation on an individual basis was only fair (kappa = 0.46, distance vision) to poor (kappa = 0.2, near vision). The overall agreement for the questions on cognitive ability was better than the correlation, whereas the questions on reading and mathematical ability showed low agreement and low correlation.

CONCLUSION

Questionnaire assessment of vision and cognitive ability is more suitable for studying the outcome of a large population than for identifying deficits in individuals.

Systemic exposure, tolerability, and efficacy of pimecrolimus cream 1% in atopic dermatitis patients

AIMS

To measure pimecrolimus blood concentrations and to evaluate tolerability and efficacy in children and infants treated topically for atopic dermatitis with pimecrolimus cream 1% for three weeks.

METHODS

Three open label, non-controlled, multiple topical dose studies were conducted in children aged 8-14 years (study A, ten patients), and in infants aged 8-30 months (study B, eight patients) and 4-11 months (study C, eight patients). Pimecrolimus blood concentrations were determined on days 4 and 22 of treatment, and at end of study. Efficacy was assessed using the Eczema Area and Severity Index (EASI).

RESULTS

Pimecrolimus blood concentrations were consistently low, typically (81%) below 1 ng/ml, with more than half of the measurements below the assay limit of quantitation (0.5 ng/ml) in studies A and B. The highest blood concentration measured throughout the three studies was 2.6 ng/ml. The cream was well tolerated, locally and systemically. The most common adverse event suspected to be related to study medication was a transient mild to moderate stinging sensation at the application site in 5/26 patients. There was no indication of any systemic adverse effect. The patients responded well to therapy with a rapid onset of action, usually within four days. Median reductions of EASI from baseline at day 22 were 55% (study A), 63% (study B), and 83% (study C).

CONCLUSION

Three weeks treatment of children and infants with extensive atopic dermatitis, using pimecrolimus cream 1% twice daily, is well tolerated and results in minimal systemic exposure, at which no systemic effect is expected.

Eradication of dysplastic Barrett's oesophagus using photodynamic therapy: long-term follow-up

BACKGROUND AND STUDY AIMS

Barrett's oesophagus is a major risk factor for oesophageal adenocarcinoma, a condition which is rapidly increasing in incidence. Photodynamic therapy (PDT) is a developing treatment in which tissue damage is caused by the action of light on a previously administered photosensitizing agent. We present the results of long-term follow-up of its efficacy in patients with dysplastic Barrett's oesophagus.

PATIENTS AND METHODS

A total of 40 patients with low-grade dysplasia in Barrett's oesophagus were treated with oral 5-aminolaevulinic acid (ALA) at a dose of 30 mg/kg, followed by laser endoscopy 4 hours later. Patients were treated between December 1995 and December 1998, and all were followed up regularly with endoscopy and biopsies in our surveillance programme.

RESULTS

Among the patients, 35 (88%) showed a macroscopic reduction in the area of the columnar epithelium, and in all 40 patients dysplasia was found to be eradicated at 1 month. The effect has been maintained for a median follow-up of 53 months (range 18-68 months), although one patient developed a late carcinoma in an untreated area of Barrett's oesophagus 3 years after the intervention.

CONCLUSIONS

Safe and effective ablation of low-grade dysplastic Barrett's oesophagus can be achieved with the use of ALA-induced PDT, and the effects are maintained in the long term.

Low frequency electrical bioimpedance for the detection of inflammation and dysplasia in Barrett's oesophagus

Biological tissues undergoing inflammation and dysplasia seem to exhibit changes in the intercellular space that can be sensed using low frequency electrical impedance methods. Basically, low frequency electric current flows through this space and its widening as well as the disruption of the tight junction decrease the resistance, facilitating current flow. The electrical changes accompanying structural changes from columnar tissue to adenocarcinoma in Barrett's metaplastic mucosa and gastric tissue are illustrated using resected tissue from 32 patients. Two hundred and fifty-eight biopsies were analysed, correlating their electrical resistivity (R) at 9.6 kHz and their histopathological interpretation. Compared to non-inflamed non-dysplastic columnar tissue (R = 4.9 ohms m), the results suggest a small but statistically significant decrease of electrical impedance in columnar tissue showing inflammation (R = 4.2 ohms m, p = 0.016) and a larger decrease when dysplasia is present (R = 3.4 ohms m, p = 0.040). If this method is validated further, this technique could be used to obtain guided biopsies from patients undergoing surveillance programmes for Barrett's oesophagus. We aim to refine this technique using a new system with lower frequencies and, possibly, in vitro (cultured cells) and in vivo (rats) models of Barrett's oesophagus.

Photodynamic therapy for dysplastic Barrett's oesophagus: long-term follow-up

Background

Photodynamic therapy (PDT) is a novel treatment in which tissue damage is caused by the action of light on a previously administered photosensitizing agent. The results of long-term follow-up of the use of PDT in patients with dysplastic Barrett's oesophagus are presented.

Methods

Thirty-seven patients with low-grade dysplastic Barrett's oesophagus were treated with oral 5-aminolaevulinic acid (ALA) 30 mg kg1, followed by laser endoscopy 4 h later. Patients were treated between December 1995 and December 1998, and all were followed regularly with endoscopy and biopsies in the authors' surveillance programme.

Results

All patients initially showed eradication of dysplasia, and 32 of 37 had a macroscopic reduction in the length of columnar epithelium. The effect was maintained for a median of 43 (range 18–54) months, although one patient developed a late carcinoma.

Conclusion

ALA-induced PDT can provide safe and effective ablation of low-grade dysplastic Barrett's oesophagus, and the effects appear to be maintained for a protracted period of time.

Expression of proteinases and inhibitors in human breast cancer progression and survival

AIMS

The expression of proteinases and their inhibitors determines the extracellular matrix (ECM) turnover in normal and pathological processes. In cancer, proteolysis is abnormally regulated, favouring ECM degradation, which aids tumour invasion and metastasis. Previous studies have determined the expression of proteinases and inhibitors in breast cancer using a variety of techniques, including immunohistochemistry; however, most have looked at the expression of individual proteinases and/or inhibitors. Therefore, the aim of the current study was to determine the simultaneous cellular expression of matrix metalloproteinases (MMPs), plasminogen activators (PAs), and tissue inhibitors of metalloproteinases (TIMPs) in patients with breast cancer and correlate this with clinical pathological staging and survival.

METHODS

Immunohistochemistry was used to determine the expression of proteinases (MMP-1, MMP-2, MMP-3, MMP-9, urokinase-type PA, and tissue-type PA) and inhibitors (TIMP-1 and TIMP-2) in 44 patients with breast cancer.

RESULTS

The expression of all the factors studied was stronger or equivalent in tumour cells than in fibroblasts or inflammatory cells within the tumour section. Both positive and negative trends have emerged in the correlation between the cellular expression of proteinases and inhibitors and breast tumour pathology (tumour grade, lymphovascular invasion, and Nottingham prognostic index).

CONCLUSIONS

The interactions between proteinases and their inhibitors in breast cancer progression are complex. Although there are differences in the expression of these factors that relate to differences in breast cancer pathology, there are no outstanding individual factors that consistently correlate with prognosis. Therefore, different factors are probably important at different stages of the process, and the balance in the relative concentrations of proteinases and inhibitors probably determines ECM degradation in breast tumour invasion and metastasis in vivo.

Offline telepathology diagnosis of colorectal polyps: a study of interobserver agreement and comparison with glass slide diagnoses

BACKGROUND/AIMS

Technological advances have produced telepathology systems with high quality colour images and reasonable transmission times. Most applications of telepathology have centred on the remote diagnosis of frozen sections or remote real time expert opinions. This study investigates the reproducibility and accuracy of offline telepathology as a primary diagnostic medium for routine histopathology specimens.

METHODS

One hundred colorectal polyps (50 hyperplastic, 50 adenomatous) were presented in a randomised order to five histopathologists as offline images on a telepathology workstation. Six images of each case were used: the slide label, a low power scan of all material on the slide, and four higher magnification views. The times taken to prepare the images, and to make the diagnoses, were recorded. Interobserver agreement was measured with kappa statistics and compared with the glass slide diagnoses.

RESULTS

The kappa statistics for the interobserver agreement on the telepathology images lay in the range of 0.90-1.00, which is interpreted as excellent agreement, and were significantly higher than those for the glass slide diagnoses (range, 0.84-0.98; p = 0.001). The median time taken to capture the images for a case was 210 seconds. The median time taken to make a diagnosis from the telepathology images was five seconds, which was significantly shorter than for the glass slide diagnoses (median, 13 seconds; p < 0.0005).

CONCLUSIONS

Offline telepathology has the potential to be a primary diagnostic medium for routine histopathology with a high degree of reproducibility and short diagnosis times. Further studies are required to validate offline telepathology for different types of specimens and different operators of the image capture system.

Are clinicians failing to supply adequate information when requesting a histopathological investigation?

AIMS

There is a perception among histopathologists that specimens are often received without adequate clinical details. This is the first study to determine the adequacy of information provided when histopathological investigations are requested.

METHODS

Two thousand sequential requests for histological examination were assessed for adequacy and completeness.

RESULTS

There was no significant difference in the demographic details supplied by physicians and surgeons. Clinical details were inadequate in 6.1% of cases: those from physicians were significantly more often adequate (98.7% v 90.6%) and more often included a diagnosis (74.4% v 38.8%) than those from surgeons. Physicians were more likely to supply their name and contact number but requests frequently lacked details of the sender.

CONCLUSIONS

Specimens are infrequently received with inadequate demographic details, but clinical details and details of the sender are more often lacking. Education of clinical colleagues is required if pathologists are to manage the demand for the service.

Aminolevulinic acid-induced photodynamic therapy: safe and effective ablation of dysplasia in Barrett's esophagus

Photodynamic therapy (PDT) is a treatment in which cell damage is achieved by the action of light on a photosensitizer. The aim of this study was to assess the value of PDT in the treatment of Barrett's esophagus with low-grade dysplasia (LGD). Forty patients with dysplastic Barrett's esophagus were given aminolevulinic acid (ALA) 30 mg/kg orally followed 4 h later by laser endoscopy. Follow-up endoscopy and biopsies were performed at 1, 6 and 12 months. A macroscopic response was seen in 33 out of 40 patients, with a median decrease in columnar epithelial area of 30% (range 0-90%). Post-treatment biopsies showed no dysplasia in 39 out of 40 patients, with LGD remaining in one case. This was maintained at 6 and 12 months. There were no significant side-effects. This study demonstrates that ALA-induced PDT provides safe and effective ablation therapy for Barrett's esophagus and is particularly useful against dysplasia.

The long term ophthalmic morbidity of low birth weight children: a review

Low birth weight infants are at greater risk of ophthalmic morbidity compared to children born at term. There are numerous studies detailing the outcome of low birth weight infants and the purpose of this paper is to discuss and summarize these studies, focusing on the long term effects on visual function and the prevalence of strabismus. The variation in study design will be discussed with regard to the subsequent effect on results. Despite the significant variation between studies, they all report an increase in the prevalence of strabismus and reduced visual acuity. This increase in ophthalmic morbidity is due in part to retinopathy of prematurity (ROP), but not all ophthalmic morbidity can be attributed to ROP.

Maternal nutrition alters the expression of insulin-like growth factors in fetal sheep liver and skeletal muscle

We investigated the influence of maternal dietary restriction between days 28 and 80 of gestation followed by re-feeding to the intake of well-fed ewes up to 140 days of gestation (term is 147 days) in sheep, on expression of mRNA for insulin-like growth factor (IGF)-I, IGF-II and growth hormone receptor (GHR) in fetal liver and skeletal muscle. Singleton bearing ewes either consumed 3.2-3.8 MJ/day of metabolisable energy (ME) (i.e. nutrient restricted - approximately 60% of ME requirements, taking into account requirements for both ewe maintenance and growth of the conceptus) or 8.7-9.9 MJ/day (i.e. well fed - approximately 150% of ME requirements) between days 28 and 80 of gestation. All ewes were then well fed (150% of ME requirements) up to day 140 of gestation and consumed 8-10.9 MJ/day. At days 80 and 140 of gestation, five ewes were sampled from each group and fetal tissues taken. There was no difference in fetal body weight or liver weights between groups at either sampling date, or skeletal muscle (quadriceps) weight at 140 days. IGF-I mRNA abundance was lower in livers of nutrient-restricted fetuses at day 80 of gestation (nutrient restricted 2.35; well fed 3.70 arbitrary units), but was higher than well-fed fetuses at day 140 of gestation, after 60 days of re-feeding (restricted/re-fed 4.27; well fed 2.83;s.e.d. 0.98 arbitrary units, P=0.061 for dietxage interaction). IGF-II mRNA abundance was consistently higher in livers of nutrient-restricted fetuses (80 days: nutrient restricted 7.78; well fed 5.91; 140 days: restricted/re-fed 7.23; well fed 6.01;s.e.d. 1.09 arbitrary units, P=0.061 for diet). Nutrient restriction had no effect on hepatic GHR mRNA abundance, but re-feeding of previously nutrient-restricted fetuses increased GHR mRNA compared with continuously well-fed fetuses (80 days: nutrient restricted 70.6; well fed 75.1; 140 days: restricted/re-fed 115.7; well fed 89.4;s.e.d. 10.13 arbitrary units, P=0.047 for dietxage interaction). In fetal skeletal muscle, IGF-I mRNA abundance was not influenced by maternal nutrition and decreased with gestation age (P<0.01). IGF-II mRNA abundance was higher in skeletal muscle of nutrient-restricted fetuses compared with well-fed fetuses at day 80 of gestation (nutrient restricted 16.72; well fed 10.53 arbitrary units), but was lower than well-fed fetuses after 60 days of re-feeding (restricted/re-fed 7.77; well fed 13.72;s.e.d. 1.98 arbitrary units, P<0.001 for dietxage interaction). There was no effect of maternal nutrition or gestation age on fetal skeletal muscle GHR expression. In conclusion, maternal nutrient restriction in early to mid gestation with re-feeding thereafter results in alterations in hepatic and skeletal muscle expression of IGF-I, IGF-II and/or GHR in the fetus which may subsequently relate to altered organ and tissue function.

Validation of a decision support system for the cytodiagnosis of fine needle aspirates of the breast using a prospectively collected dataset from multiple observers in a working clinical environment

We have used a 692 case dataset, collected retrospectively by a single observer, to develop decision support systems for the cytodiagnosis of fine needle aspirates of breast lesions. In this study, we use a 322 case dataset that was prospectively collected by multiple observers in a working clinical environment to test two predictive systems, using logistic regression and the multilayer perceptron (MLP) type of neural network. Ten observed features and the patient age were used as input features. The systems were developed using a training set and test set from the single observer dataset and then applied to the multiple observer dataset. For the independent test cases from the single observer dataset, with a threshold set for no false positives on the training set, logistic regression produced a sensitivity of 82% (95% confidence interval 73-91) and a predictive value of a positive result (PV +) of 98% (95-99), the values for the MLP were 79% (69-89) and 100%, respectively. However the performance on the prospective multiple observer dataset was much worse, with a sensitivity of 72% (65-80), and PV + of 97% (94-99) for logistic regression and 67% (60-75) and 91% (85-97) for the MLP. These results suggest that there is considerable interobserver variability for the defined features and that this system is unsuitable for further development in the clinical environment unless this problem can be overcome.

Photodynamic therapy for dysplastic Barrett's oesophagus: a prospective, double blind, randomised, placebo controlled trial

BACKGROUND AND AIMS

Photodynamic therapy (PDT) is a treatment in which cell damage is achieved by the action of light on a photosensitizing agent. We have assessed the potential use of PDT in the ablation of Barrett's oesophagus.

METHODS

Thirty six patients with dysplastic Barrett's oesophagus receiving acid suppression medication with omeprazole were randomised to receive oral 5-aminolaevulinic acid (ALA) 30 mg/kg or placebo, followed four hours later by laser endoscopy. Follow up endoscopy was performed at one, six, 12, and 24 months.

RESULTS

Of 18 patients in the ALA group, a response was seen in 16 (median decrease in area in the treated region 30%; range 0-60%). In the placebo group, a decrease in area of 10% was observed in two patients with no change in 16 (median 0%; range 0-10%; treatment v placebo, p<0.001). No dysplasia was seen in the columnar epithelium within the treatment area of any patient in the PDT group. However, in the placebo group, persistent low grade dysplasia was found in 12 patients (p<0.001). There were no short or long term major side effects. The effects of treatment were maintained for up to 24 months.

CONCLUSIONS

This is the first randomised controlled trial of PDT for Barrett's oesophagus. It demonstrates that ALA induced PDT can provide safe and effective ablation of low grade dysplastic epithelium.

What levels of agreement can be expected between histopathologists assigning cases to discrete nominal categories? A study of the diagnosis of hyperplastic and adenomatous colorectal polyps

AIMS

To assess the levels of agreement between histopathologists for a two-class nominal categorization process--the discrimination between hyperplastic and adenomatous colorectal polyps.

METHODS

Fifty hyperplastic and 50 adenomatous polyps received consecutively in the laboratory were categorized by nine histopathologists, and the level of agreement between all observers and the original diagnosis was assessed using kappa statistics.

RESULTS

For the eight observers with 11 months or more experience in histopathology, there was a high level of agreement with kappa statistics ranging from 0.84 to 0.98. This process was performed rapidly with an average of 13 to 22 seconds spent on each case. One observer with only 6-weeks' experience of histopathology had a lower overall level of agreement with kappa statistics ranging from 0.46 to 0.54, but the performance on the later cases was much higher.

CONCLUSIONS

The level of agreement in the distinction between hyperplastic and adenomatous colorectal polyps is high among histopathologists with at least moderate amounts of experience in histopathology. The one virtually naïve observer showed a marked learning response during the study without feedback on case outcome. This suggests that histopathologists are very reliable in assigning cases to distinct nominal categories and that learning of these processes occurs early in a histopathologist's career.

Assessing the conditions for in vivo electrical virtual biopsies in Barrett's oesophagus

It has previously been shown that it is possible to differentiate between squamous and columnar epithelia in rat and resected human tissues using an impedance probe to make in vitro measurements. This probe can be passed down an endoscope allowing measurements to be made in patients. However, the probe emerges parallel to the oesophageal wall, with little room to manoeuvre. The conditions of control required to give reliable readings have been investigated. The importance of pressure applied and the angle of approach to the oesophagus was assessed. Pressures in the range 26.6 Pa to 46.3 kPa and angles in the range 15-90 degrees were considered. In in vitro studies it was observed that it was possible to obtain consistent readings with pressures greater than 2.9 kPa and with angles greater than 15 degrees between the probe and the oesophagus. These conditions can be achieved in vivo, and readings obtained from twelve patients are shown (45 readings on normal squamous, 34 on Barrett's oesophagus and 22 on stomach). At low frequencies (9.6-153.2 kHz), a Mann-Whitney test shows a significant difference (p < 0.001) when comparing the means from squamous and columnar, and also when readings from Barrett's and normal gastric epithelia are compared (p < 0.001).

Proteolysis in human breast cancer

BACKGROUND

The process of proteolysis is important at several stages of the metastatic cascade. A balance between the expression of the genes encoding endogenous proteinases and inhibitors exists and when the production of proteinases exceeds that of inhibitors proteolysis occurs.

AIMS

To determine whether differences in the profile and activity of proteinases and inhibitors exist within breast tumour tissue (n = 51), surrounding background breast tissue (n = 43), normal breast tissue from breast reduction mammoplasty operations (n = 10), and cells of the breast cancer cell line, MCF-7.

METHODS

Proteinase (matrix metalloproteinase 1 (MMP-1), MMP-2, MMP-3, MMP-9, urokinase-type plasminogen activator (uPA), and tissue-type PA (tPA)) and inhibitor (tissue inhibitor of metalloproteinases; TIMP-1 and TIMP-2) expression and proteinase activity were compared using substrate zymography, western blotting, immunohistochemistry, and quenched fluorescent substrate hydrolysis.

RESULTS

The presence of all proteinases and inhibitors was greater in breast tumour tissue when compared with all other types of breast tissue (p < 0.05). The activity of total MMPs as determined by quenched fluorescent substrate hydrolysis was also greater in breast tumours (p < 0.05).

CONCLUSIONS

There is increased proteolysis in human breast tumours when compared with other breast tissues.

Differences in hair follicle dermal papilla volume are due to extracellular matrix volume and cell number: implications for the control of hair follicle size and androgen responses

The size of a hair follicle is thought to be determined by the volume of its dermal papilla. The volume of the dermal papilla depends on the number of cells it contains and on the volume of the extracellular matrix. To establish which of these two variables is related to differences in hair follicle size we performed a stereologic study on 235 hair follicles from different sites, including male facial skin (beard), female facial skin, and scalp. In facial follicles there was a strong correlation between the area of the hair cortex and the volume of the dermal papilla. The area of the hair cortex also correlated with the number of cells in the dermal papilla and with the volume of dermal papilla per cell. In scalp hair follicles, where there was a smaller range of sizes, the correlations between these variables were weaker. In large male facial follicles the mean total dermal papilla volume was almost 40-fold higher than in vellus follicles from female facial skin. This difference was associated with a mean 17-fold greater number of cells in the dermal papilla and a 2.4-fold greater volume associated with each cell. Intermediate results were obtained in scalp follicles. In many regions of the skin hair follicles enlarge in response to androgens during adult life hair. Our results imply that the increase in the volume of the dermal papilla in these follicles is due to an increase in the number of cells, either through proliferation or through the migration of cells from the follicular dermal sheath, and to an increase in the amount of extracellular matrix per cell. As androgens are thought to act primarily on the dermal papilla, these changes may have a direct bearing on the mechanism of androgen-mediated alterations in hair follicle size.

Ablation treatment for Barrett oesophagus: what depth of tissue destruction is needed?

AIM

To establish the depth of Barrett's columnar epithelium and normal squamous oesophageal epithelium, in order to determine the depth of destruction required in ablation treatment for Barrett oesophagus.

METHODS

Histological specimens from 100 cases of Barrett oesophagus and 100 samples of normal squamous oesophageal epithelium were studied. Using a system of multiple measurements until the change in cumulative mean values varied by less than 5%, the overall mean and normal range of depth was calculated for each type of epithelium.

RESULTS

Barrett columnar epithelium is minimally thicker (mean (SEM) 0.50 (0.004) mm; range 0.39 to 0.59 mm) than normal squamous epithelium (0.49 (0.003) mm; 0.42 to 0.58 mm), although this difference is probably too small to be of clinical relevance.

CONCLUSIONS

Although there are numerous clinical reports of various methods of ablation treatment for Barrett oesophagus, little attention has been paid to the depth of tissue destruction required. This is the first study to look specifically at this issue, and it provides information on the necessary depth of epithelial ablation.

A simple method for PCR based analyses of immunohistochemically stained, microdissected, formalin fixed, paraffin wax embedded material

Microdissection was performed on sections cut from formalin fixed, paraffin wax embedded archival material, which had been subjected to conventional immunohistochemistry. Crude DNA extracts, which were obtained from these microdissected samples by a simple microwave step, were then added directly to amplification reactions. Analyses using a range of polymerase chain reaction (PCR) based techniques, including microsatellite repeat polymorphism analysis at the NM23-H1 locus and sequencing of exons 5, 7, and 8 of the p53 gene, were performed successfully. Universal PCR amplification was also carried out on the microdissected material and probes suitable for use in comparative genomic hybridisation (CGH) were obtained in all cases. This technique will enable a range of effective genetic analyses to be carried out on specific subsets of cells that have been characterised previously by immunohistochemistry.

The influence of maternal nutrient restriction in early to mid-pregnancy on placental and fetal development in sheep

Placental weight is a primary factor determining size at birth in many species. In sheep, placental weight peaks at approximately mid-gestation, with structural remodelling occurring over the second half of pregnancy to meet the increasing nutritional demands of the growing fetus. Numerous factors influence placental growth and development in sheep, and many workers (see Kelly, 1992) have investigated the role of maternal nutrition as a regulator of placental and fetal size. We have studied the effects of feeding ewes approximately 50% of their recommended energy requirements during early to mid-pregnancy on fetal and placental indices measured at mid-gestation (i.e. 80 d) and close to term (i.e. 145 d). Maternal nutrient restriction is associated with a reduction in placental weight at 80 d, but an increase in placental weight at 145 d of gestation, compared with ewes fed adequately in early pregnancy. No significant effect on fetal weight was observed at either 80 or 145 d gestation, although differences in body dimensions and the insulin-like growth factor-1 axis were found in lambs from nutrient-restricted ewes delivered close to term. Maternal nutrition during pregnancy plays a pivotal role in the regulation of fetal and placental development in sheep, and therefore has the potential to influence both short- and longer-term health outcomes.

Virtual biopsies in Barrett's esophagus using an impedance probe

Preliminary results of electrical impedance measurements in squamous and columnar epithelia in rat and human tissues are presented. The aim of this work is to show the possibility of differentiating these two types of epithelia in terms of their electrical characteristics. For the measurements, we employed a 1.95-m-long, 3.2-mm-diameter, four-electrode probe designed to be used transendoscopically in the diagnosis of Barrett's esophagus (BE). BE is a condition in which the normal squamous epithelium of the esophagus is replaced by columnar epithelium of the intestinal type. This metaplasia is considered as a premalignant condition that puts patients at a 30-125-fold risk of developing adenocarcinoma of the esophagus. The diagnosis and surveillance of BE involve taking multiple biopsies, an expensive and time-consuming procedure. This study constitutes the first stage in the replacement of tissue biopsy by "virtual biopsies".

Audit of neonatal intensive care transport--closing the loop

To audit the effectiveness of changes in transport arrangements, data on babies ventilated during transfer into a neonatal unit were compared between two periods. During the first period, August 1991-February 1993, an ad hoc transport team operated. Transport practice was changed in 1993 by forming a nine-person nursing transport team, improving training and upgrading monitoring. The second audit period was January 1994-July 1995. The groups were not significantly different for birthweight, gestation or levels of ventilation. Physiological variables were assessed with a "transport score". Improved scores for temperature and pH were achieved on completion of transfer in 1994-95 compared to 1991-93. Stabilizing prior to transfer took longer in the 1994-95 period. No serious deteriorations occurred in transit in the 1994-95 period, three in 1991-93. Audit facilitates identification of problems in transport. Staff, education and equipment changes were associated with improved audited outcomes.

Image analysis of low magnification images of fine needle aspirates of the breast produces useful discrimination between benign and malignant cases

Fine needle aspirates of the breast (FNAB) (n = 362; 204 malignant, 158 benign), prepared by cytocentrifuge methods and stained by the Papanicolaou technique, were analysed using a semi-automated image analysis system at a low magnification which precluded resolution of nuclear detail. The measured parameters were integrated optical density, fractal textural dimension, number of cellular objects (single cells and contiguous groups of cells), distance between cellular objects (mean, s.d., skewness and kurtosis), area of cellular objects (mean, s.d., skewness, kurtosis) and the nearest neighbour statistic. The cases were divided into a 200-case training set and a 162-case test set. Analysis was performed by logistic regression and the multi-layer Perceptron type of artificial neural network. Logistic regression and the neural network produced similar performances with a sensitivity of 82-83%, specificity 85% and a positive predictive value for a malignant result of 85%. A non-parametric analysis of all the predictor variables showed that all except the mean area of cellular objects and the s.d. of this measurement were significant discriminants (P < 0.05), but most were highly interrelated and this was reflected in the selection of only three predictor variables by forward and backward conditional logistic regression. This study shows that much diagnostic information is present in low power views of FNAB, and that image analysis could form the basis of a semi-automated decision-support aid.

Chemical ablation of the gallbladder

BACKGROUND

Chemical ablation of the gallbladder might avoid the need for surgery in elderly, unfit patients. This study examined the efficacy of various chemicals in destroying gallbladder mucosa.

METHODS

Ninety-five per cent ethanol, 3 per cent sodium tetradecyl sulphate (STD), trifluoroacetic acid (TFA) 2 mol/l, tetracycline 50 mg/ml, 30 and 50 per cent phenol, and a mucosal exfoliant solution (compound ethylene diamine tetra-acetic acid) were tested for gallbladder ablation in rabbits. Histology was obtained 8 weeks after exposure to these chemicals.

RESULTS

Thirty per cent phenol, tetracycline, TFA and ethanol when used as single agents were moderately effective in causing complete gallbladder mucosal obliteration, 50 per cent phenol caused a macroscopic burn of the entire gallbladder. The mucosal exfoliant solution and STD on their own did not cause mucosal destruction but had significantly enhanced efficacy when combined with 95 per cent ethanol, allowing reliable mucosal destruction with a 5-min contact duration.

CONCLUSION

Ninety-five per cent ethanol and STD after pretreatment with a mucosal exfoliant solution may be the combination of choice for in situ gallbladder mucosal ablation.

Cytokine and chemokine regulation of proMMP-9 and TIMP-1 production by human peripheral blood lymphocytes

The production and activation of matrix-degrading proteinases such as the matrix metalloproteinases (MMP) by lymphocytes is likely to be an important factor in facilitating lymphocyte trafficking through the endothelial barrier and the extracellular matrix. Leukocyte infiltration into inflammatory sites occurs as a response to members of the chemokine superfamily and other inflammatory mediators. In the present study, highly purified leukocyte subpopulations were cultured with or without chemokines or cytokines, and their ability to express gelatinolytic MMPs and their inhibitors, the tissue inhibitors of metalloproteinase (TIMPs), was analyzed. In the absence of exogenous stimuli, purified CD4+ T lymphocytes produced similar quantities of proMMP-9 and elevated levels of TIMP-1 compared with PBMC, while purified CD8+ and CD3+ populations exhibited less MMP-9 and TIMP-1 activity. In comparison, CD56+ (NK) cells secreted barely detectable levels of proMMP-9 and TIMP-1. The secretion of proMMP-9 by PBMC and purified CD3+, CD4+, and CD8+ lymphocytes was selectively modulated by beta chemokines and proinflammatory cytokines. ProMMP-9 secretion by CD3+ and CD4+, but not by CD8+ T cells was augmented in response to TNF-alpha and IL-1, and down-regulated by IFN-gamma, while macrophage inflammatory protein (MIP)-1alpha, MIP-1beta, and RANTES (regulated upon activation and normally T cell expressed and secreted) (beta chemokines) up-regulated the secretion of proMMP-9 by all of the lymphocyte subsets tested. These results demonstrate that a number of proinflammatory cytokines and chemokines differentially regulate proMMP-9 secretion from purified CD4+ and CD8+ lymphocytes, while for purified CD3+ T cells (consisting of CD4+ and CD8+ cells in approximately a 2:1 ratio), a predominantly CD4+ lymphocyte response profile was demonstrated.

Cytokine and chemokine regulation of proMMP-9 and TIMP-1 production by human peripheral blood lymphocytes

The production and activation of matrix-degrading proteinases such as the matrix metalloproteinases (MMP) by lymphocytes is likely to be an important factor in facilitating lymphocyte trafficking through the endothelial barrier and the extracellular matrix. Leukocyte infiltration into inflammatory sites occurs as a response to members of the chemokine superfamily and other inflammatory mediators. In the present study, highly purified leukocyte subpopulations were cultured with or without chemokines or cytokines, and their ability to express gelatinolytic MMPs and their inhibitors, the tissue inhibitors of metalloproteinase (TIMPs), was analyzed. In the absence of exogenous stimuli, purified CD4+ T lymphocytes produced similar quantities of proMMP-9 and elevated levels of TIMP-1 compared with PBMC, while purified CD8+ and CD3+ populations exhibited less MMP-9 and TIMP-1 activity. In comparison, CD56+ (NK) cells secreted barely detectable levels of proMMP-9 and TIMP-1. The secretion of proMMP-9 by PBMC and purified CD3+, CD4+, and CD8+ lymphocytes was selectively modulated by beta chemokines and proinflammatory cytokines. ProMMP-9 secretion by CD3+ and CD4+, but not by CD8+ T cells was augmented in response to TNF-alpha and IL-1, and down-regulated by IFN-gamma, while macrophage inflammatory protein (MIP)-1alpha, MIP-1beta, and RANTES (regulated upon activation and normally T cell expressed and secreted) (beta chemokines) up-regulated the secretion of proMMP-9 by all of the lymphocyte subsets tested. These results demonstrate that a number of proinflammatory cytokines and chemokines differentially regulate proMMP-9 secretion from purified CD4+ and CD8+ lymphocytes, while for purified CD3+ T cells (consisting of CD4+ and CD8+ cells in approximately a 2:1 ratio), a predominantly CD4+ lymphocyte response profile was demonstrated.

The association between nm23 gene expression and survival in patients with sarcomas

The relationship between the expression of nm23, a putative metastasis-suppressor gene and prognosis was determined for 88 patients with sarcomas. Immunohistochemistry using immunopurified anti-nm23 peptide antibodies was performed and the results of each case graded according to the degree of staining. Univariate and multivariate analyses were carried out to determine the prognostic significance of nm23 staining for sarcoma patients. Expression of nm23 was found to increase in line with metastatic potential in many cases but this did not reach significance for the study as a whole. However, the possibility of nm23 loss occurring in association with metastasis cannot be ruled out in some more aggressive sarcomas, as was demonstrated for six patients with low-scoring, unclassified and synovial sarcomas that had metastasized. The time to metastasis was longer for patients with grade 3 sarcomas (50-75% of tumour cells staining) than similar patients in other staining groups. These results suggest that expression of nm23 genes in sarcomas is variable and has no value as a prognostic indicator for these mesenchymal tumours.

Blood culture is poor method of confirming pneumococcus as cause of childhood pneumonia

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