A descriptive analysis of first trimester urinary concentrations of 14 bisphenol analogues in the MIREC Canadian pregnancy cohort.

BACKGROUND: Concern over the health effects of BPA, particularly for the developing fetus, has led to an increasing use of bisphenol analogues in industrial and consumer products, which may be as hormonally active as BPA. Biomonitoring data for many bisphenol analogues, especially in pregnant populations, are limited. METHODS: We measured concentrations of 14 bisphenol analogues in 1st trimester urine samples (n = 1851) from the Maternal-Infant Research on Environmental Chemicals (MIREC) Canadian pregnancy cohort (2008-2011). We examined patterns of exposure according to sociodemographic and sampling characteristics as well as occupation and frequency of consumption of canned fish within the previous 3 months. RESULTS: BPA was detected in 89% of participants with a specific gravity standardized geometric mean concentration of 0.990 µg/L. Biphenol 4,4' (BP 4,4'), 4,4'-dihydroxydiphenyl ether (DHDPE), and bisphenol E (BPE) were detected in >97% of participants. Bisphenol F (BPF) and bisphenol S (BPS) were detected in >60% of participants. Specific gravity standardized geometric mean concentrations of these 5 compounds ranged from 0.024 to 0.564 µg/L. Nine bisphenol analogues were detected in <9% of participants. Concentrations of BP 4,4', DHDPE, and BPE were higher in younger women and those with higher pre-pregnancy BMI, lower household income, lower education, and among smokers. We found a similar pattern of differences in BPF for age, education, and smoking status while BPS similarly differed across categories of pre-pregnancy BMI. Participants who were unemployed or working in the service industry had higher molar sum of 7 bisphenol analogues than those working in healthcare, education, or an office setting. Canned fish consumption was not related to bisphenol analogue concentrations. CONCLUSION: BP 4,4', DHDPE, BPE, BPF, and BPS were highly detected in 1st trimester urine samples in this large pan-Canadian pregnancy cohort. This suggests widespread exposure to these analogues around 2008-2011 and warrants further investigation into associations with health outcomes.

Metastases from gastric cancer presenting as colorectal lesions: a report of two cases and systematic review.

Gastric cancer is common with well-established routes of spread. Metastasis to the colon or rectum is rare; however, we have recently managed two patients with this clinical picture. We present these cases together with a literature review of current practice. A systematic review in PubMed using the terms 'gastric cancer' and 'colorectal metastasis' was performed. The identified papers were screened for relevance and the reference lists of relevant papers were also reviewed to ensure capture of all relevant reports. Twenty-four papers containing 26 cases of gastric cancer with metastasis to the colon or rectum were found. There was wide variation in presentation and practice in these cases, which tended to be in patients with poor histopathological features. Diagnosis is often challenging owing to the unusual radiological appearance and submucosal nature of the metastatic lesions. Treatment ranges from palliative care to radical resection. Colorectal metastases from gastric primary cancer are rare, but cases are reported and should be part of the index of suspicion during the work-up of patients with lower gastrointestinal symptoms and a history of gastric cancer. Treatment options range from aggressive surgical resection to palliative care and should be centred on the patient's fitness and wishes.

Referral practices of recent graduate and experienced physiotherapists working in Australian primary care for people with musculoskeletal conditions.

BACKGROUND: People with musculoskeletal conditions often seek care from physiotherapists. Some, particularly those at risk of poor outcomes, may benefit from referral to physiotherapists with expertise in managing musculoskeletal conditions and/or multidisciplinary care. Understanding referral practices of physiotherapists, and how experience influences those practices, may assist in implementing optimal care pathways in primary care. AIMS: Explore (i) current referral practices of recent graduate and experienced physiotherapists who manage musculoskeletal conditions; (ii) opinions about referral to specialist physiotherapists for people at risk of poor outcomes. METHODS: This qualitative study consisted of 23 semi-structured interviews with recent graduate (n = 9) and experienced physiotherapists (n = 14) working in primary care. Perspectives of participants' current referral practices (to whom, when and why they are referred) and referral to specialist physiotherapists were sought. Interviews were recorded and transcribed verbatim prior to analysis. RESULTS: Referral practices for both groups were influenced by specific diagnoses, complexity of presentations, confidence, self-awareness, the clinical environment and system-related factors. Experienced physiotherapists were more confident and specific in their referrals and had established trusted networks compared with new graduates. Early referral to specialist physiotherapists was more likely when therapists were co-located. Barriers to early referral were lack of awareness, health system factors and impact on the patient (e.g., financial, time, continuity of care). CONCLUSION: Understanding factors influencing referral decisions may improve both intra- and interprofessional care for people with musculoskeletal conditions. Referral of people at risk of poor outcomes to specialist physiotherapists may be improved by greater intraprofessional awareness and clarity of roles.

Protracted diagnosis of ACNES: a costly exercise.

This case report summarizes the course of events leading to diagnosis and eventual repair of anterior cutaneous nerve entrapment syndrome (ACNES) in a 58-year-old female. The time period elapsing from initial symptoms to final operative repair was 9 months. The diagnosis was missed by both medical and surgical specialists despite multiple outpatient appointments, investigative procedures and a battery of laboratory tests. The diagnosis of ACNES was first considered when reviewed by a hernia surgeon and subsequently confirmed following open exploration of the anterior abdominal wall. The nerve was released and pain symptoms resolved. Access to the NHS Scotland ISD register permitted an economic analysis of the diagnostic services utilized for this patient and these totalled nearly £11 500. At a time when the NHS is focused on cost effectiveness, this particular sequence of investigations illustrates a protracted and costly diagnostic pathway.

Incidence of cutaneous squamous cell carcinoma in a New Zealand population of chronic lymphocytic leukaemia patients.

BACKGROUND: Chronic lymphocytic leukaemia (CLL) is associated with an increased incidence and aggressiveness of skin cancers, particularly cutaneous squamous cell carcinoma (cSCC), but little is known about cSCC incidence in Australasian CLL patients. AIM: In this retrospective study, we analysed the incidence of cSCC in patients seen at a tertiary hospital in New Zealand (NZ). METHODS: We retrospectively assessed the clinical history and histology data of CLL patients (n = 371) who presented to the Haematology Department, Christchurch Hospital, NZ during the period 1996-2015. Baseline characteristics, incidence of second cancers, treatment details and overall survival were analysed. RESULTS: During follow-up (median = 11.8 years), 221 second cancers were recorded in 88 patients. Of these cancers, 185 were cSCC, removed from 61 patients. In 56% of these patients, >1 cSCC was removed, and the majority of cSCC occurred following the treatment for CLL. The cumulative incidence of a first cSCC was 11% at 5 years, whereas the cumulative incidence of a subsequent cSCC was 88% at 5 years. The incidence of cSCC in male patients was threefold higher than that reported for the general NZ population. CONCLUSION: NZ CLL patients have a high incidence of cSCC relative to the levels observed in the general population, which are themselves among the highest in the world. The careful monitoring of CLL patients is warranted, particularly those who have a progressive disease or have had a first cSCC removed.

Chronic lymphocytic leukaemia cells become both activated and immunosuppressive following interaction with CD3 and CD28 stimulated PBMC.

Chronic lymphocytic leukaemia (CLL) is associated with immunosuppression. The activation of CLL cells induced by interaction with other cell types, particularly activated T-cells, within the tumour micro-environment is thought to be important for CLL progression. However it is unclear whether activated CLL cells (CLL(Act)) have immunosuppressive capacity. We report that co-culture of CLL cells with normal PBMC in the context of CD3/CD28 T-cell activation generates CLL(Act) with increased CD38 expression that are capable of suppressing the proliferative responses of both CD4+ and CD8+ T-cells. The suppression required cell contact but did not involve induction of T-cell apoptosis.

The effect of dihydrotestosterone exposure during or prior to the masculinization programming window on reproductive development in male and female rats.

Masculinization is programmed by androgen exposure during a masculinization programming window (MPW). Deficiency in MPW androgen action results in reduced size of all reproductive organs and anogenital distance (AGD) and reproductive disorders. Although timing of MPW closing has been defined, what determines 'opening' and 'closing' of the MPW remains unknown. To test whether initiation of testosterone production/action defines the opening of the window, we first demonstrated that androgen receptor mRNA and protein are expressed prior to the MPW, and then investigated whether masculinization could be advanced or enhanced by treating pregnant rats with either 1 or 10 mg/kg/day dihydrotestosterone (DHT) prior to (early window, EW; e11.5-e14.5) or during the MPW (e15.5-e18.5), and then evaluating offspring in foetal life (e18.5, e21.5), early puberty (day 25) or adulthood (∼day 75). DHT treatment did not affect pregnancy duration, birth, litter or pup size. DHT exposure in either time window did not advance foetal male development (Wolffian duct coiling) and had no effect on AGD, testis, penis and ventral prostate (VP) size at any age when measured; there was a tendency towards smaller penis size. In contrast, exposure of females to 10 mg DHT in either time window induced varying degrees of masculinization, including stabilization of the Wolffian duct and increased AGD (e21.5, Pnd25), VP formation, more male-like phallus structure, absence of nipples and vaginal opening and, in some adult females, gross fluid distension of the uterus (hydrometrocolpos); these effects were generally more pronounced after exposure in the MPW than in the EW. In conclusion, exposure of the male rat foetus to additional androgens prior to or during the MPW does not advance or enhance any measured parameter of reproductive development. Therefore, androgen availability plays no role in determining timing of the MPW. Susceptibility of the female reproductive system to androgens may precede the MPW.

Left prefrontal cortex control of novel occurrences during recollection: a psychopharmacological study using scopolamine and event-related fMRI.

Recollection and familiarity represent two processes involved in episodic memory retrieval. We investigated how scopolamine (an antagonist of acetylcholine muscarinic receptors) influenced brain activity during memory retrieval, using a paradigm that separated recollection and familiarity. Eighteen healthy volunteers were recruited in a randomized, placebo-controlled, double-blind design using event-related fMRI. Participants were required to perform a verbal recognition memory task within the scanner, either under placebo or scopolamine conditions. Depending on the subcondition, participants were required to make a simple recognition decision (old/new items) or base their decision on more specific information related to prior experience (target/non-target/new items). We show a drug modulation in left prefrontal and perirhinal cortex during recollection. Such an effect was specifically driven by novelty and showed an inverse correlation with accuracy performance. Additionally, we show a direct correlation between drug-related signal change in left prefrontal and perirhinal cortices. We discuss the findings in terms of acetylcholine mediation of the familiarity/novelty signal through perirhinal cortex and the control of the relative signal strength through prefrontal cortex.

The learning environment for junior doctor training--what hinders, what helps.

As part of a larger study on learning outcomes for the first year of postgraduate medical training (already reported), semi-structured interviews with middle grade trainees were used to explore their perceptions of trainee development during this first training year. Data generated focused not only on learning outcomes, but also on important process issues. Dissatisfaction was expressed with formal and informal teaching and learning opportunities. Factors that enhance the learning environment were identified. These included being supported, a feeling of being a valued member of the team, being stretched but not over stretched, having a broad range of experiences, knowing the system, having a clear remit and being well organized. Factors inhibiting the learning environment included fractured working patterns, insufficient time with patients and seniors, as well as the converse of many of the enhancing factors. The process issues gathered in this paper will be of interest to those involved in the delivery of training for junior doctors.

Extranodal follicular lymphoma: a clinicopathological and genetic analysis of 15 cases arising at non-cutaneous extranodal sites.

AIMS: Recent studies of primary cutaneous follicular lymphoma suggest that it represents a clinicopathological entity distinct from nodal follicular lymphoma (FL). The purpose of this study was to determine if FL arising at other extranodal sites is more closely related to FL occurring in the skin or in lymph nodes. METHODS AND RESULTS: Fifteen cases of non-cutaneous extranodal follicular lymphoma (ENFL) were identified from the Scotland and Newcastle Lymphoma Group (SNLG) database. All were stage 1E at presentation and involved the tonsil (n = 3), palate (n = 3), skeletal muscle (n = 2), ileum (n = 2), duodenum (n = 1), stomach (n = 1), thyroid gland (n = 1), submandibular gland (n = 1) and fallopian tube (n = 1). Polymerase chain reaction for t(14;18) using primers to the major breakpoint cluster region was performed on 14 cases of ENFL and the incidence of the translocation compared with that found in 16 cases of stage 1 nodal FL. Clinical and follow-up data were obtained from the SNLG database for the 15 cases of ENFL and 87 cases of stage 1 nodal FL, and a comparison of outcomes made. Only 2/14 cases of ENFL had detectable t(14;18) compared with 9/16 stage 1 nodal FL (P < 0.01). Freedom from progression and disease-specific survival was similar for the 15 cases of ENFL and 87 cases of stage 1 nodal FL. However, 13/15 patients with ENFL were disease free at the end of follow-up compared with 49/87 stage 1 nodal FL (P < 0.02). CONCLUSIONS: The low incidence of t(14;18) and favourable outcome encountered in ENFL in this study is similar to that previously found for primary cutaneous FL. These results support the concept of a subtype of FL lacking t(14;18) involving the major breakpoint cluster region, and with a propensity to arise at extranodal sites. Despite a high relapse rate, patients with ENFL are more likely to achieve complete remission and may ultimately have a more favourable long-term prognosis than those with equivalent nodal disease.

Exit learning outcomes for the PRHO year: an evidence base for informed decisions.

OBJECTIVE: To evaluate potential learning outcomes for pre-registration house officer (PRHO) training and develop an evidence base for informed decision making. DESIGN AND SETTING: A 2-stage Delphi process was employed to establish the opinions of Scottish stakeholders with regard to learning outcomes for the PRHO year. PARTICIPANTS: Doctors involved in the provision of PRHO training, including deans, postgraduate tutors and general practitioners (GPs) with trainees, were invited to participate in the study. MAIN OUTCOME MEASURES: Respondents rated a range of outcomes according to which they believed should be included or excluded from the PRHO training year. RESULTS: Learning outcomes identified for PRHOs were grouped under the 12-domain framework of the 3-circle model: 'What the doctor can do', 'How they approach their practice' and 'Their professionalism'. Based on the consensus opinions gained in the Delphi study, the ratings were classified into priority groupings. Priority 1 contained 45 of the original 81 learning outcomes, representing each area of the 3-circle model, with emphasis on the domains of clinical skills, patient investigation/management, communication, appropriate attitudes and personal development. Health promotion and disease prevention was the only domain not represented at priority 1. Priority 2 contained 24 outcomes with emphasis on the understanding of clinical skills, patient management and personal development. Priority 3 contained 12 outcomes indicating a lack of emphasis for some outcomes, particularly the role of the doctor and health promotion. CONCLUSION: Consensus on the learning outcomes for PRHO training has been achieved, providing an evidence base for curriculum planning. The relative priority assigned to these outcomes can facilitate the use of the evidence. This evidence base should be referred to when reviewing any PRHO training programme.

Human 'testicular dysgenesis syndrome': a possible model using in-utero exposure of the rat to dibutyl phthalate.

BACKGROUND: The disorders comprising human 'testicular dysgenesis syndrome' (TDS) may be increasing in incidence. TDS originates in fetal life but the mechanisms are not known, and discerning them requires an animal model. METHODS AND RESULTS: The study investigated whether male rats exposed in utero to dibutyl phthalate [DBP; 500 mg/kg on gestational days (GD) 13-21] would provide a suitable model for human TDS. DBP induced a high rate (>60%) of cryptorchidism (mainly unilateral), hypospadias, infertility and testis abnormalities, similar to those in human TDS. Cell-specific immunohistochemistry and confocal microscopy were used to track development of Sertoli [anti-Müllerian hormone (AMH), Wilm's tumour (WT-1) protein, p27(kip)], Leydig [3beta-hydroxysteroid dehydrogenase (3beta-HSD)], germ (DAZL protein) and peritubular myoid (smooth muscle actin) cells from fetal life to adulthood. In scrotal and cryptorchid testes of DBP-exposed males, areas of focal dysgenesis were found that contained Sertoli and Leydig cells, and gonocytes and partially formed testicular cords; these dysgenetic areas were associated with Leydig cell hyperplasia at all ages. Suppression ( approximately 90%) of testicular testosterone levels on GD 19 in DBP-exposed males, coincident with delayed peritubular myoid cell differentiation, may have contributed to the dysgenesis. Double immunohistochemistry using WT-1 (expressed in all Sertoli cells) and p27(kip) (expressed only in mature Sertoli cells) revealed immature Sertoli cells in dysgenetic areas. DBP-exposed animals also exhibited Sertoli cell-only (SCO) tubules, sporadically in scrotal and predominantly in cryptorchid, testes, or foci of SCO within normal tubules in scrotal testes. In all SCO areas the Sertoli cells were immature. Intratubular Leydig cells were evident in DBP-exposed animals and, where these occurred, Sertoli cells were immature and spermatogenesis was absent. Abnormal Sertoli cell-gonocyte interaction was evident at GD 19 in DBP-exposed rats coincident with appearance of multinucleated gonocytes, although these disappeared by postnatal day 10 during widespread loss of germ cells. CONCLUSIONS: Abnormal development of Sertoli cells, leading to abnormalities in other cell types, is our hypothesized explanation for the abnormal changes in DBP-exposed animals. As the testicular and other changes in DBP-exposed rats have all been reported in human TDS, DBP exposure in utero may provide a useful model for defining the cellular pathways in TDS.

How many camels are there in Italy? Cognitive estimates standardised on the Italian population.

OBJECTIVE: We provided the standardisation of a new Cognitive Estimation Task (CET). PARTICIPANTS: the test was administered to 175 healthy subjects. RESULTS: performance on the Cognitive Estimation Task (CET) is associated with gender (where women show poorer performance than men) and education (where more highly educated individuals show better performance compared to individuals with lower levels of education). However,CET performance is not associated with age. DISCUSSION: the lack of age effects on the CET may be explained by the task dependence on "crystallised intelligence", which is less affected by healthy adult ageing than "fluid intelligence".

New doctors' perceptions of their educational development during their first year of postgraduate training.

The General Medical Council (GMC) in the UK describes a wide range of competences in which the new medical graduate should develop during the first postgraduate year. New graduates are known as pre-registration house officers (PRHOs). In this study, semi-structured open interviews with PRHOs approaching the end of their first postgraduate year were used to explore the trainees' perceptions of their development. After the interview their views on the importance given in their experience to the GMC's competences were explored though a questionnaire. Most noticeable from the interview data was the PRHOs'emphasis in the development of generic skills required of working in the 'real world'--skills such as communication, team working and the ability to cope with responsibility. In some outcomes, their noticeable progression, e.g. communication, or lack of progression, e.g. health promotion, reflected their views on the importance given. With other outcomes there was a paradox, e.g. practical skills were rated highly but were not noticeably developed; the role of the doctor was noticeably developed but was not highly rated. Overall the PRHOs developed most strongly in the 'professionalism' domain with not all the skills in the 'tasks' domain being similarly developed. This study helps to define the benefits and opportunities of the PRHO year, as currently perceived by the trainees, and should be of interest to those involved in the planning and delivery of postgraduate training.

The Scottish doctor--learning outcomes for the medical undergraduate in Scotland: a foundation for competent and reflective practitioners.

This paper describes a set of learning outcomes that clearly define the abilities of medical graduates from any of the five Scottish medical schools. The outcomes are divided into 12 domains that fit into one of three essential elements for the competent and reflective medical practitioner.

Expression of oestrogen receptor beta (ERbeta1) protein in human breast cancer biopsies.

Oestrogen action is mediated via specific receptors that act as ligand-activated transcription factors. A monoclonal antibody specific to the C-terminus of human oestrogen receptor beta has been characterized and the prevalence of expression of oestrogen receptor beta protein investigated in a well defined set of breast cancers. Reverse transcription-polymerase chain reaction analysis of RNA from tissue biopsies detected oestrogen receptor beta in all samples examined. The anti-oestrogen receptor beta antibody cross reacted specifically with both long (approximately 59 Kd) and short (approximately 53 Kd) forms of recombinant oestrogen receptor beta. Western blot analysis of breast tumours contained both forms of oestrogen receptor beta protein although in some samples lower molecular weight species (32--45 Kd) were identified. Fifty-one breast cancer biopsies were examined using immunohistochemistry; 41 (80%) were immunopositive for oestrogen receptor alpha, 48 (94%) were immunopositive for oestrogen receptor beta and 38 (74.5%) co-expressed both receptors. Expression of oestrogen receptor beta was exclusively nuclear and occurred in multiple cell types. There was no quantitative relationship between staining for the two ERs although in tumours in which both receptors were present immunoexpression of oestrogen receptor alpha was invariably more intense. The significance of oestrogen receptor beta protein expression in breast cancers to therapy remains to be determined but the availability of a well characterized antibody capable of detecting oestrogen receptor beta in archive material will facilitate the process.

Development and validation of a new monoclonal antibody to mammalian aromatase.

The biosynthesis of oestrogens from androgens is catalysed by the aromatase complex, an essential component of which is the aromatase cytochrome P450 (P450 arom) protein. Expression of a functional P450 arom is essential for normal fertility in males and females and the sequence of the protein is highly conserved. We have raised a new monoclonal antibody against a conserved peptide and validated it on fixed tissue sections of the rat, common marmoset (Callthrix jacchus) and human. The monoclonal antibody was used successfully for Western analysis and specifically reacted with a 55 kDa protein in microsomal extracts. On sections of ovaries in all three species, expression in follicles was specific to the mural granulosa cells of antral follicles and was present in corpora lutea. In the human and marmoset, staining of luteal cells was markedly heterogeneous and did not appear to vary consistently with the stage of the cycle. The intensity of immunostaining was elevated in corpora lutea from pregnant rats and following human chorionic gonadotropin rescue in the human. In the testis, the highest levels of expression were observed in the Leydig cells within the interstitium. In adult rat and marmoset, and possibly also in the human, some P450 arom was associated with the cytoplasm surrounding elongate spermatids but other germ cells were immunonegative. In conclusion, a new monoclonal antibody specific for P450 arom recognises the protein in rodent, primate and human. Its ability to work on fixed tissue sections will facilitate identification of individual cells expressing P450 arom within complex tissues.

RNA binding protein Musashi1 is expressed in sertoli cells in the rat testis from fetal life to adulthood.

The Musashi1 (Msi1) gene identified in mouse is a member of a subfamily of RNA binding proteins that are highly conserved across species. Msi1 expression is highly enriched in proliferative cells within the developing central nervous system. Within the testis, proliferation and differentiation of germ cells takes place within the seminiferous epithelium, where these cells are supported physically and functionally by Sertoli cells that do not themselves proliferate following the onset of puberty. RNA binding proteins expressed in testicular germ cells are essential for normal fertility. Preliminary data suggested the mRNA for Msi1 was present in ovary; therefore, we used an Msi1-specific cRNA and monoclonal antibody to investigate whether Msi1 was expressed in the testis. Msi1 mRNA was expressed in rat testis from birth until adulthood; in situ hybridization revealed silver grains within the seminiferous epithelium. Immunohistochemical studies demonstrated that at all ages examined (from Fetal Day 14.5 until adulthood) Msi1 protein was expressed in Sertoli cells. In fetal and adult rat ovaries, Msi1 was detected in granulosa cells and their precursors. In Sertoli cells, protein was detected in both cytoplasmic and nuclear compartments; in adult testes, the immunointensity of the nuclear staining was stage dependent, with highest levels of expression in Sertoli cells at stages I-VI. In rat gonads, the RNA binding protein Msi1 is expressed in both proliferating and nonproliferating Sertoli and granulosa cells.

The development of articular cartilage: evidence for an appositional growth mechanism.

It is well-established that cartilage grows by a combination of matrix secretion, cell hypertrophy and cell proliferation. The extent to which this growth is by appositional, as opposed to interstitial mechanisms, however, remains unclear. Using the knee joints of the marsupial Monodelphis domestica to study cartilage growth, we have combined an immunohistochemical study of the TGF-beta family of cartilage growth and differentiation factors between 30 days postpartum to 8 months, together with a stereological analysis of cartilage morphology during growth. Furthermore, to gain an insight into the generation of the characteristic zones within cartilage, we have examined the effects of intra-articular administration of bromodeoxyuridine, an agent that is incorporated into DNA during cell division and blocks further cell cycling. During early growth, TGF-beta2 and -beta3 were widely expressed but TGF-beta1 was less so. After the formation of the secondary centre of ossification, all isoforms became more restricted to the upper half of the tissue depth and their distribution was similar to that previously described for IGFs, and PCNA-positive cells. Stereological analysis of tissue sections from the femoral condylar cartilage at 3 and 6 months showed that there was a 17% increase in total cartilage volume but a 31% decrease in cell density on a unit volume basis. Finally, cell-cycle perturbation with BrDU, which was injected into the knee joints of 3-month-old animals and analysed 1 and 4 months post-injection, revealed that the chondrocytes occupying the transitional zone were depleted 1 month post-injection, resulting in thinning of the articular cartilage. This effect was reversed 4 months post-injection. Immunohistochemical analysis revealed that BrDU-treatment altered the expression patterns of all TGF-beta isoforms, with a marked reduction in labelling of TGF-beta1 and -beta3 isoforms in the upper half of the cartilage depth. Overall, the data lends further support to the notion of articular cartilage growing by apposition from the articular surface rather than by interstitial mechanisms.