Characterisation of key proteoglycans in the cranial cruciate ligaments (CCLs) from two dog breeds with different predispositions to CCL disease and rupture.

Cranial cruciate ligament disease and rupture (CCLD/R) is one of the most common orthopaedic conditions in dogs, eventually leading to osteoarthritis of the stifle joint. Certain dog breeds such as the Staffordshire bull terrier have an increased risk of developing CCLD/R. Previous studies into CCLD/R have found that glycosaminoglycan levels were elevated in cranial cruciate ligament (CCL) tissue from high-risk breeds when compared to the CCL from a low-risk breed to CCLD/R. Our objective was to determine specific proteoglycans/glycosaminoglycans in the CCL and to see whether their content was altered in dog breeds with differing predispositions to CCLD/R. Disease-free CCLs from Staffordshire bull terriers (moderate/high-risk to CCLD/R) and Greyhounds (low-risk to CCLD/R) were collected and key proteoglycan/glycosaminoglycans were determined by semi-quantitative Western blotting, quantitative biochemistry, quantitative reverse transcription polymerase chain reaction, and immunohistochemistry. Gene expression of fibromodulin (P = 0.03), aggrecan (P = 0.0003), and chondroitin-6-sulphate stubs (P = 0.01) were significantly increased, and for fibromodulin this correlated with an increase in protein content in Staffordshire bull terriers compared to Greyhound CCLs (P = 0.02). Decorin (P = 0.03) and ADAMTS-4 (P = 0.04) gene expression were significantly increased in Greyhounds compared to Staffordshire bull terrier CCLs. The increase of specific proteoglycans and glycosaminoglycans within the Staffordshire bull terrier CCLs may indicate a response to higher compressive loads, potentially altering their risk to traumatic injury. The higher decorin content in the Greyhound CCLs is essential for maintaining collagen fibril strength, while the increase of ADAMTS-4 indicates a higher rate of turnover helping to regulate normal CCL homeostasis in Greyhounds.

Insulin-like growth factor binding protein (IGFBP6) is a cross-species tendon marker.

The main challenge in tendon injury management is suboptimal tissue healing that fails to re-establish original tendon function. Tissue bioengineering is a promising approach for tendon therapy, with potential to improve its functional outcomes. However, evaluation criteria for tissue-engineered tendon are unclear due to the lack of specific markers of differentiated tendon. The study aim was to identify a panel of genes that characterised tendons in comparison to cartilage or muscles and validate those genes, both in human and key species used as models for tendon diseases. Gene expression profiling of rat tendon and cartilage in whole-tissue samples and primary tenocytes and chondrocytes was undertaken using two independent microarray platforms. Genes that demonstrated high expression correlation across two assays were validated by qRT-PCR in rat tendon relative to cartilage and muscle. Five genes demonstrating the highest tendon-related expression in the validation experiment (ASPN, ECM1, IGFBP6, TNMD, THBS4) were further evaluated by qRT-PCR in ovine, equine and human tissue. The group of tendon markers, identified by unbiased transcriptomic analysis of rat musculoskeletal tissues, demonstrated species-dependent profiles of expression. Insulin-like growth factor binding protein 6 (IGFBP6) was identified as the only universal tendon marker. Further investigation in equine tendon showed that IGFBP6 expression was not affected by ageing or tendon function but decreased in anatomical regions subjected to elevated compressive force. IGFBP6 is a robust cross-species marker of tendon phenotype and may find application in evaluation of tendon physiology and guided differentiation of permissive cells towards functional tenocytes.

A systems biology approach to defining regulatory mechanisms for cartilage and tendon cell phenotypes.

Phenotypic plasticity of adult somatic cells has provided emerging avenues for the development of regenerative therapeutics. In musculoskeletal biology the mechanistic regulatory networks of genes governing the phenotypic plasticity of cartilage and tendon cells has not been considered systematically. Additionally, a lack of strategies to effectively reproduce in vitro functional models of cartilage and tendon is retarding progress in this field. De- and redifferentiation represent phenotypic transitions that may contribute to loss of function in ageing musculoskeletal tissues. Applying a systems biology network analysis approach to global gene expression profiles derived from common in vitro culture systems (monolayer and three-dimensional cultures) this study demonstrates common regulatory mechanisms governing de- and redifferentiation transitions in cartilage and tendon cells. Furthermore, evidence of convergence of gene expression profiles during monolayer expansion of cartilage and tendon cells, and the expression of key developmental markers, challenges the physiological relevance of this culture system. The study also suggests that oxidative stress and PI3K signalling pathways are key modulators of in vitro phenotypes for cells of musculoskeletal origin.

RNA binding proteins regulate anabolic and catabolic gene expression in chondrocytes.

OBJECTIVE: Regulation of anabolic and catabolic factors is considered essential in maintaining the homoeostasis of healthy articular cartilage. In this study we investigated the influence of RNA binding proteins (RNABPs) in this process. DESIGN: Using small interfering RNA (siRNA), RNABP expression was knocked down in SW1353 chondrosarcoma cells and human articular chondrocytes. Gene expression and messenger RNA (mRNA) decay of anabolic (SOX9, Aggrecan) and catabolic (matrix metalloproteinase (MMP)13) factors were analysed using reverse transcription quantitative polymerase chain reaction (RT-qPCR). RNA-electromobility shift assays (EMSAs) were used to investigate RNABP interactions with the SOX9 mRNA 3' untranslated region (UTR). Immunohistochemical localisation of MMP13 and the RNABP human antigen R (HuR) was performed in E13.5 and E16.5 mouse embryo sections. RESULTS: SOX9 mRNA, mRNA half-life and protein expression were increased with siRNA targeting the RNABP tristetraprolin (TTP) in both HACs and SW1353s. TTP knockdown also stimulated aggrecan mRNA expression but did not affect its stability. RNA-EMSAs demonstrated that adenine uracil (AU)-rich elements in the SOX9 mRNA 3'UTR interacted with chondrocyte proteins with three specific elements interacting with TTP. HuR knockdown significantly increased MMP13 expression and also regulated the expression of a number of known transcriptional repressors of MMP13. HuR was ubiquitously expressed within mouse embryos yet displayed regional down-regulation within developing skeletal structures. CONCLUSION: This study demonstrates for the first time how RNABPs are able to affect the balance of anabolic and catabolic gene expression in human chondrocytes. The post-transcriptional mechanisms controlled by RNABPs present novel avenues of regulation and potential points of intervention for controlling the expression of SOX9 and MMP13 in chondrocytes.

Fat pad-derived mesenchymal stem cells as a potential source for cell-based adipose tissue repair strategies.

BACKGROUND: Mesenchymal stem cells are able to undergo adipogenic differentiation and present a possible alternative cell source for regeneration and replacement of adipose tissue. The human infrapatellar fat pad is a promising source of mesenchymal stem cells with many source advantages over from bone marrow. It is important to determine whether a potential mesenchymal stem-cell exhibits tri-lineage differentiation potential and is able to maintain its proliferation potential and cell-surface characterization on expansion in tissue culture. We have previously shown that mesenchymal stem cells derived from the fat pad can undergo chondrogenic and osteogenic differentiation, and we characterized these cells at early passage. In the study described here, proliferation potential and characterization of fat pad-derived mesenchymal stem cells were assessed at higher passages, and cells were allowed to undergo adipogenic differentiation. MATERIALS AND METHODS: Infrapatellar fat pad tissue was obtained from six patients undergoing total knee replacement. Cells isolated were expanded to passage 18 and proliferation rates were measured. Passage 10 and 18 cells were characterized for cell-surface epitopes using a range of markers. Passage 2 cells were allowed to undergo differentiation in adipogenic medium. RESULTS: The cells maintained their population doubling rates up to passage 18. Cells at passage 10 and passage 18 had cell-surface epitope expression similar to other mesenchymal stem cells previously described. By staining it was revealed that they highly expressed CD13, CD29, CD44, CD90 and CD105, and did not express CD34 or CD56, they were also negative for LNGFR and STRO1. 3G5 positive cells were noted in cells from both passages. These fat pad-derived cells had adipogenic differentiation when assessed using gene expression for peroxisome proliferator-activated receptor γ2 and lipoprotein lipase, and oil red O staining. DISCUSSION: These results indicate that the cells maintained their proliferation rate, and continued expressing mesenchymal stem-cell markers and pericyte marker 3G5 at late passages. These results also show that the cells were capable of adipogenic differentiation and thus could be a promising source for regeneration and replacement of adipose tissue in reconstructive surgery.

Increased blood mRNA expression of inflammatory and anti-fibrotic markers in dogs with congestive heart failure.

Inflammation and extracellular matrix (ECM) remodeling contribute to the development of congestive heart failure (CHF), but the pathogenesis is still incompletely understood. Therefore, whole blood samples from eight dogs without cardiac disease and eight dogs with CHF were investigated for mRNA expression of IL1ß, IL2, IL4, IL6, IL8, IL10, TNFα, IFNγ, TGFß1-3, MMP1, -2, -3, -9 and TIMP1-4 using quantitative PCR. Dogs with CHF had significantly higher IL1ß (P=0.015), IL2 (P=0.043), MMP1 (P=0.031), TIMP3 (P=0.012) and lower TNFα (P<0.001), TGFß3 (P=0.006), TIMP1 (P=0.015) and TIMP2 (P=0.011) mRNA levels. Increased pro-inflammatory IL1ß and anti-fibrotic MMP1 and reduced pro-fibrotic TGFß and TIMP1 and TIMP2 in dogs with CHF suggest progressive left ventricular remodeling. The reduction of TNFα and increase of immunomodulatory IL2 and TIMP3 might suggest control of the inflammatory response. A better understanding of inflammation and ECM remodeling in cardiac diseases may lead to novel treatment approaches.

Leptin expression in dogs with cardiac disease and congestive heart failure.

BACKGROUND: Leptin belongs to the group of adipokines and has recently attracted attention because of its effects on the cardiovascular system. Increased leptin concentrations are reported in obese dogs but its role in cardiac disease (CD) is not known. Therefore, we investigated leptin expression in blood samples from dogs with congestive heart failure (CHF), and from myocardial samples of dogs with CDs. METHODS: Leptin mRNA was analyzed from blood samples of 8 dogs presented for cardiac screening in which no abnormalities were detected and 8 dogs in CHF. In addition, myocardial samples (interventricular septum, right and left atria, and ventricles) of 10 dogs with no cardiac abnormalities (controls), 7 dogs with acquired and 3 dogs with congenital CDs were investigated using real-time polymerase chain reaction (PCR). RESULTS: Dogs with CHF had significantly higher blood concentrations of leptin mRNA than dogs without CD (P = .013). Myocardial leptin expression was significantly increased in acquired (P = .035) and decreased in congenital CD (P = .016) in comparison to controls. Dogs in heart failure stage D showed higher myocardial leptin concentrations than dogs in stage C3 and B (P = .031). Differences according to myocardial region (P < .05) were detected and higher leptin concentrations were present in the atria in comparison to the ventricles in dogs with CD (P = .005). Comparing male and female dogs with CD revealed higher leptin concentrations in female dogs (P = .001). CONCLUSIONS: These results indicate leptin mRNA concentrations vary with CD, severity of CD, myocardial region, and possibly sex. Therefore, leptin might play a role in canine CD.

Post-transcriptional gene regulation following exposure of osteoarthritic human articular chondrocytes to hyperosmotic conditions.

OBJECTIVE: Osmolarity is a major biophysical regulator of chondrocyte function. Modulation of chondrocytic marker gene expression occurs at the post-transcriptional level following exposure of human articular chondrocytes (HAC) to hyperosmotic conditions. This study aims to further characterise the post-transcriptional response of HAC to hyperosmolarity. METHODS: Gene expression and microRNA (miRNA) levels in freshly isolated HAC after 5h under control or hyperosmotic conditions were measured using microarrays. Regulated genes were checked for the presence of AU rich elements (AREs) in their 3' untranslated regions (3'UTR), whilst gene ontology was examined using Ingenuity Pathway Analysis (IPA). RNA decay rates of candidate ARE-containing genes were determined in HAC using actinomycin D chase experiments and the involvement of the p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinases 1 and 2 (ERK1/2) pathways were investigated using pharmacological inhibitors. RESULTS: Hyperosmolarity led to the regulation of a wide variety of genes. IPA identified enrichment of genes involved with cell stress responses, cell signalling and transforming growth factor ß (TGFß) signalling. Importantly, upregulated genes were over-represented with those containing AREs, and RNA decay analysis demonstrated that many of these were regulated post-transcriptionally by hyperosmolarity in HAC. Analysis of miRNA levels in HAC indicated that they are only modestly regulated by hyperosmotic conditions, whilst inhibitor studies showed that p38 MAPK and ERK1/2 were able to block hyperosmotic induction of many of these genes. CONCLUSION: Through microarray and bioinformatics analysis we have identified genes which are post-transcriptionally regulated in HAC following exposure to hyperosmotic conditions. These genes have a range of functions, and their regulation involves transduction through the p38 MAPK and ERK1/2 pathways. Interestingly, our results suggest that miRNA regulation is not key to the process. Overall, this work illustrates the range of processes regulated in chondrocytes by changes in their osmotic environment, and underlines the importance of post-transcriptional mRNA regulation to chondrocyte function.

Regulation of SOX9 in normal and osteoarthritic equine articular chondrocytes by hyperosmotic loading.

OBJECTIVES: SOX9 is a transcription factor that is essential for cartilage extracellular matrix (ECM) formation. Osteoarthritis (OA) is characterised by a loss of cartilage ECM. In chondrocytes SOX9 gene expression is regulated by osmotic loading. Here we characterise SOX9 mRNA regulation through static and cyclical application of hyperosmotic conditions in normal and OA monolayer equine chondrocytes. Furthermore, we investigate whether extracellular signal-regulated protein kinase (ERK)1/2 mitogen-activated protein kinases (MAPK) pathways have a role in this regulation of SOX9. METHODS: Equine chondrocytes harvested from normal or OA joints were subjected to different osmotic loading patterns as either primary (P0) or passaged (P2) cells. The involvement of MEK-ERK signalling was demonstrated by using pharmacological inhibitors. In addition SOX9 gene stability was determined. Levels of transcripts encoding SOX9, Col2A1 and aggrecan were measured using qRT-PCR. De novo glycosaminoglycan synthesis of explants was determined with (35)S sulphate during static hyperosmolar loading. RESULTS: MEK-ERK signalling increases glycosaminoglycans (GAG) synthesis in explants. Static hyperosmotic conditions significantly reduced SOX9 mRNA in normal P2 and OA P0 but not normal P0 chondrocytes. SOX9 mRNA was stabilised by hyperosmotic conditions. Cyclical loading of normal P2 and OA P0 but not normal P0 cells led to an increase in SOX9 gene expression and this was prevented by MEK1/2 inhibition. CONCLUSIONS: The response to osmotic loading of SOX9 mRNA is dependent on the nature of the osmotic stimulation and the chondrocyte phenotype. This variation may be important in disease progression.

Critical heat stress evaluation of clothing ensembles with different levels of porosity.

A common metric of assessing the evaporative cooling potential of protective clothing is to assess the rate of diffusion of water vapour through the fabric. Another mechanism that supports evaporative cooling is convective transfer. Prototype porous coveralls were constructed to promote convective air flow with 0.0024 mm (0.06 inch) holes representing nominal openings of 0, 1, 2, 5, 10 and 20% of the garment surface area (called P00, P01, P02, P05, P10 and P20). The purpose of this study was to evaluate the ability of these porous coverall configurations to support evaporative cooling. The assessment measures were critical wet bulb globe temperature (WBGT) and apparent evaporative resistance via a progressive heat stress protocol. There was a progressive increase in critical WBGT with increases in convective permeability for P00, Saratoga Hammer, P01, work clothes and P02. There was no further increase for P05, P10 and P20. A similar pattern was found for diffusive permeability, with the exception of Saratoga Hammer, which suggested that the convective permeability could explain evaporative cooling better than diffusive permeability. STATEMENT OF RELEVANCE: Protective clothing often interferes with evaporative cooling and thus increases the level of heat stress. While increased diffusion of water vapour is associated with lower evaporative resistances, the convective movement of water vapour is a dominant mechanism and better explains the role of the clothing in heat stress.

The epitope characterisation and the osteogenic differentiation potential of human fat pad-derived stem cells is maintained with ageing in later life.

Some clinical settings are deficient in osteogenic progenitors, e.g. atrophic nonunited fractures, large bone defects, and regions of scarring and osteonecrosis. These benefit from the additional use of bone marrow-derived mesenchymal stem cells, but these cells exhibit an age-related decline in lifespan, proliferation and osteogenic potential. Therapeutic approaches for the repair of bone could be optimised by the identification of a stem cell source that does not show age-related changes. Fat pad-derived stem cells are capable of osteogenesis, but a detailed study of the effect of ageing on their epitope profile and osteogenic potential has so far not been performed. Fat pad-derived cells were isolated from 2 groups of 5 patients with a mean age of 57 years (S.D. 3 years) and 86 years (S.D. 3 years). The proliferation, epitope profile and osteogenic differentiation potential of cells from the 2 groups were compared. Cells isolated from the fat pad of both groups showed similar proliferation rates and exhibited a cell surface epitope profile similar but not identical to that of bone marrow-derived stem cells. The cells from both groups cultured in osteogenic medium exhibited osteogenesis as shown by a significant upregulation of alkaline phosphatase and osteocalcin genes, and significantly greater alkaline phosphatase enzyme activity compared to cells cultured in the control medium. The cells cultured in the osteogenic medium also showed greater calcium phosphate deposition on alizarin red staining. There was no significant difference between the osteogenic potential of the two age groups for any of the parameters studied. The fat pad is a consistent and homogenous source of stem cells that exhibits osteogenic differentiation potential with no evidence of any decline with ageing in later life. This has many potential therapeutic tissue engineering applications for the repair of bone defects in an increasingly ageing population.

Differences in repair responses between immature and mature cartilage.

Cartilage has a poor reparative capacity although it is unclear as to what extent this may be dependent on age or maturation. In the current study, the cellular responses of chondrocytes to experimental wounding in vitro using embryonic, immature, and mature cartilage have been compared. In all cases, the response was consistent (a combination of cell death that included apoptosis and proliferation). The speed of response varied in terms of cell death with embryonic cartilage showing the most rapid response and mature cartilage showing the slowest response. Intrinsic repair as assessed by the ability to heal the lesion was not detected in any of the culture systems used. It was concluded that the poor repair potential of cartilage is not maturation dependent in the systems studied.

Belching and bloating: facts and fantasy after antireflux surgery.

BACKGROUND: Fundoplication is commonly complicated by belching difficulty and abdominal bloating. Postoperative belching ability, however, is difficult to assess; subjective patient reporting is often used but may be unreliable. Manometric measurement of the gastro-oesophageal 'common cavity' is an objective marker of gastro-oesophageal gas reflux. METHODS: Twenty patients who had undergone Nissen fundoplication and 11 healthy controls underwent oesophageal manometry at rest and during gastric distension for 10 min with 750 ml of gas. RESULTS: Half of the patients reported an inability to belch; the other half reported varying degrees of belching difficulty, most of whom were rarely able to relieve bloating by belching. During gastric distension, none of the patients had transient lower oesophageal sphincter relaxation, while the controls had a median of 1 (range 0-1). Patients had fewer common cavities than controls; however, none of the belch urges experienced during gastric distension in patients was associated with a common cavity, compared with 48 per cent in controls. CONCLUSION: After fundoplication, patients do not belch as a result of gastro-oesophageal gas reflux; rather it may be due to oesophagopharyngeal reflux of swallowed air. Subjective reporting of belching ability is inaccurate and manometric measurement of common cavities provides a better means of assessment.

The reactions of articular cartilage to experimental wounding: role of apoptosis.

OBJECTIVE: To determine the cellular and matrix responses to experimental wounding of articular cartilage. METHODS: Immature and mature bovine articular cartilage was used as an in vitro model system to study the cellular responses to cartilage wounding. Explant cultures were wounded centrally with a trephine and maintained for up to 10 days. TUNEL labeling together with ultrastructural analyses were used to assess the nature of the observed cell death. In vitro labeling with 3H-thymidine was used to detect cell proliferation, and 2 antibodies (COL2-3/4M and BC-13) were used to detect changes in matrix turnover. RESULTS: Cell death was observed as a response to wounding and was considered to be a combination of necrosis and apoptosis. In immature tissue, cell death was more pronounced, particularly in the articular surface region. Within the area of cell death, many cells that did not die subsequently underwent proliferation. The collagenous network showed evidence of denaturation in the area of the wound, but "aggrecanase" activity was not detected. CONCLUSION: There are 2 contrasting, but related, responses to cartilage wounding--apoptosis and proliferation. In order to improve cartilage repair, future studies need to elucidate the regulatory mechanisms that determine these responses.

Fine-needle aspiration biopsy of parotid lesions: comparison with frozen section.

BACKGROUND: Opinions vary as to the necessity for fine-needle aspiration biopsy (FNAB) in parotid tumours. The present study reflects the experience gained over a 12-year period and shows the accuracy of a diagnostic FNAB, and improved results with experience. METHODS: Between 1983 and 1995, 201 parotid lesions were excised by one surgeon(AGP) and a prospective database was established. Fine-needle aspiration biopsy was performed prior to surgery in 195 lesions and frozen section was performed in 159 lesions. RESULTS: The FNAB was diagnostic in 129 (66%) specimens and its sensitivity for malignancy was 90% and specificity was 100% (excluding non-diagnostic FNAB, where there was insufficient cellular material for reliable diagnosis or where specific tissue diagnosis could not be given). The positive predictive value was 100% and the negative predictive value was 98%. Of interest, the positive predictive value of diagnostic FNAB for pleomorphic adenomas was 99%. A specific tumour diagnosis could not be made on the FNAB sample in 37 specimens; 11 of these lesions were histologically confirmed as malignant after excision. Frozen section was diagnostic in 144 specimens (91%). Its sensitivity for malignancy was 96% and specificity was 99%. The positive predictive value was 96% and negative predictive value 99%. A specific tumour diagnosis could not be made on frozen section in 15 specimens including six cases in which malignancy was finally reported. The positive predictive value of diagnostic frozen section for pleomorphic adenomas was 99%. CONCLUSIONS: A diagnostic FNAB is an accurate and useful tool in the management of parotid lesions. An FNAB diagnosis of pleomorphic adenoma obviates the need for frozen section. The performance of FNAB in parotid tumours does not in any way preclude the necessity of surgical removal of such lesions except in exceptional circumstances.

The illness behavior of patients with gastroesophageal reflux disease with and without endoscopic esophagitis.

The aim of this study was to determine if patients who experience heartburn but have no objective evidence of gastroesophageal reflux disease are responding appropriately to their symptoms. One hundred and forty patients who had been referred for investigations of heartburn (75 males, 65 females, mean age 48 years) answered an Illness Behavior Questionnaire. All patients underwent pH monitoring tests, and endoscopy results were obtained for 119 patients. There was objective evidence of reflux disease on endoscopy or pH monitoring in 105 patients and no objective evidence of reflux in 35 patients. Sixty-six patients were endoscopy-'positive' while 53 patients were endoscopy-'negative'. The Illness Behavior Questionnaires for the four groups were analysed for seven scales of illness behavior and these were compared with reference populations. Patients with heartburn but no objective reflux were similar to those with heartburn and objective reflux on all scales of the Illness Behavior Questionnaire. The reflux group without endoscopic esophagitis also responded to their symptoms in the same way as those with endoscopic esophagitis. It is concluded that a patient's perception of symptoms in gastroesophageal reflux is probably not related to the degree of esophageal mucosal damage.

A prospective study of the effect of fundoplication on primary and secondary peristalsis in the esophagus.

We studied 13 patients before and after Nissen fundoplication and compared them with 11 healthy volunteers and 12 other patients with dysphagia after fundoplication. Esophageal manometry was performed to assess primary and secondary peristalsis induced by esophageal distention with air and water boluses. In patients with reflux disease, secondary peristalsis was initiated at a median rate of 60% of distending episodes, propagation of the secondary peristaltic wave occurred in 40% and lower oesophageal sphincter relaxation occurred with 70% of secondary peristaltic waves. Fundoplication did not alter the initiation or propagation rate of secondary peristalsis but it decreased the median lower esophageal sphincter relaxation rate to 45% (P < 0.03). Fundoplication was not associated with a change in the amplitude of primary peristaltic waves even in patients complaining of dysphagia. In post-fundoplication patients, successful secondary peristaltic waves had significantly lower (P < 0.005) proximal and distal amplitude than primary peristaltic waves. We conclude that there is no improvement in primary or secondary peristalsis after fundoplication and dysphagia after fundoplication is not due to altered peristalsis.

Papillary thyroid carcinoma arising in thyroglossal duct cysts: incidence and management.

The incidence and pathological features of papillary thyroid carcinoma arising in the thyroglossal duct cysts were reviewed and compared with papillary thyroid carcinoma arising elsewhere in the thyroid gland. In the 30 year period 1964 to 1993 there were 90 thyroglossal duct nodules or cysts treated surgically at the Endocrine Surgical Unit, Royal North Shore Hospital, Sydney, Australia. There were four cases of papillary thyroid carcinoma in this group (4.4%). In the same period 2814 cases presented with clinical single thyroid nodules which were treated surgically. There were 182 cancers in this group of which 121 were papillary thyroid carcinomas (4.3% of total cases). This is identical to the incidence seen in the thyroglossal duct. We conclude that the incidence of papillary thyroid carcinoma arising in the thyroglossal duct is no different to that arising elsewhere in the gland. The difference in number of carcinomas related only to the volume of follicular thyroid tissue present in the gland proper. That being the case, there is no reason to treat these cancers differently from papillary thyroid carcinoma elsewhere in the gland.

Reoperation after failed antireflux surgery.

Between 1978 and 1992, 61 patients were operated on for new or recurrent problems after antireflux surgery. Indications for reoperation were recurrent reflux in 50 patients (associated with dysphagia in 14), dysphagia alone in six and postprandial pain in five. At reoperation the cause of the problem was apparent as anatomical breakdown of the repair in 19 patients, gastric pull-through (slipped Nissen procedure) in 14 and paraoesophageal hernia in six. In 18 patients the cause of the symptoms was not readily apparent. Reoperation consisted of fundoplication alone in 27 patients, fundoplication with pyloroplasty in eight, fundoplication with proximal gastric vagotomy in four, a Collis-Nissen procedure in 11 (four also had pyloroplasty), a Roux-en-Y procedure in four, total gastrectomy in one and reduction of a paraoesophageal hernia in six. Of the 20 patients with some form of destruction of the gastric outlet six experienced troublesome dumping symptoms and in two this was severe. Two patients died from cardiac causes after surgery. Of the remaining 59 patients, 51 rated the procedure as successful. Repeat antireflux procedures can give results almost as good as those of primary antireflux surgery. However, pyloroplasty and gastric resection should be avoided if at all possible.