Medical students' perceptions on preparedness and care delivery for patients with autism or intellectual disability

Introduction

To provide competent care to patients with autism spectrum disorder (ASD) or intellectual developmental disorder (IDD), healthcare professionals must recognize the needs of neurodivergent populations and adapt their clinical approach. We assessed the perceived preparedness of medical students to adapt care delivery for patients with ASD/IDD, as well as their perceptions on neurodiversity education.

Methods

We conducted a sequential explanatory mixed-methods study on undergraduate medical students at McGill University during the academic year 2020-2021. We administered an online survey, followed by semi-structured interviews. We analyzed data using descriptive statistics and thematic analysis. We integrated findings at the interpretation level.

Results

We included two-hundred-ten survey responses (~29% of class), and 12 interviews. Few students felt prepared to adjust care for patients with ASD/IDD despite most indicating doing so was important. Ninety-seven percent desired more training regarding care accommodation for neurodivergent patients. Thematic analysis unveiled the perception of current insufficient education, and the value of experiential learning.

Discussion/Conclusions

This study highlights low perceived preparedness of medical students to accommodate care for neurodivergent patients, and a desire for more instruction. Incorporating interactive training in medical school curricula regarding modifying care delivery for neurodivergent individuals may improve the perceived preparedness of medical trainees to work with these patients and care quality.

A Qualitative Study on Dentists' Communication Approaches in Managing Fluoride-Hesitant Caregivers

OBJECTIVES

Guidelines on effective provider-led communication are available but may be underused in dentistry, even if such guidelines could help dentists manage complex clinical scenarios like topical fluoride hesitancy. The purpose of this study was to investigate current chairside communication approaches used by dentists with fluoride-hesitant caregivers.

METHODS

A 27-item semistructured interview script was developed and pretested with 3 dentists, revised, and finalized. One-on-one interviews were conducted with a purposive sample of pediatric dentists and general dentists from April to June 2020. Interviews were digitally recorded, transcribed, and analyzed to identify dentists' communication approaches used during clinical interactions with fluoride-hesitant caregivers. Thematic analyses identified themes and subthemes, and exemplary quotes were provided to illustrate each theme.

RESULTS

Twenty-seven dentists participated (21 pediatric dentists and 6 general dentists). The mean age of participants was 43.0 ± 8.2 y (range, 30-73). Most participants were women (88.9%), white (51.9%), and non-Hispanic (85.2%). Participants had been practicing dentistry for a mean of 13.2 ± 10.5 y (range, 2-40). There were 4 themes: leaving topical fluoride decisions completely up to the caregiver, educating the caregiver about fluoride, insisting that the caregiver accept fluoride, and engaging the caregiver and child.

CONCLUSION

Most communications approaches used by interviewed dentists to manage fluoride hesitancy in clinical settings are not evidence based. Future dental education efforts should ensure that trainees are exposed to and can demonstrate competency in appropriate, evidence-based patient-provider communication strategies.

KNOWLEDGE TRANSFER STATEMENT

The study highlights the need for dentists to apply evidence-based communication strategies when managing difficult clinical scenarios like fluoride hesitancy, which is important in optimizing dentist-patient trust.

Distinct fibroblast progenitor subpopulation expedites regenerative mucosal healing by immunomodulation

Injuries that heal by fibrosis can compromise organ function and increase patient morbidity. The oral mucosal barrier has a high regenerative capacity with minimal scarring, but the cellular mechanisms remain elusive. Here, we identify distinct postnatal paired-related homeobox-1+ (Prx1+) cells as a critical fibroblast subpopulation that expedites mucosal healing by facilitating early immune response. Using transplantation and genetic ablation model in mice, we show that oral mucosa enriched with Prx1+ cells heals faster than those that lack Prx1+ cells. Lineage tracing and scRNA-seq reveal that Prx1+ fibroblasts exhibit progenitor signatures in physiologic and injured conditions. Mechanistically, Prx1+ progenitors accelerate wound healing by differentiating into immunomodulatory SCA1+ fibroblasts, which prime macrophage recruitment through CCL2 as a key part of pro-wound healing response. Furthermore, human Prx1+ fibroblasts share similar gene and spatial profiles compared to their murine counterpart. Thus, our data suggest that Prx1+ fibroblasts may provide a valuable source in regenerative procedures for the treatment of corneal wounds and enteropathic fibrosis.

5-ALA loaded self-adhesive patch-PDT is effective and safe in the treatment of actinic keratoses on hands and arms

Photodynamic therapy (PDT) with 5-aminolevulinic acid hydrochloride (ALA) is an established method for the management of AK. PD P 506 A (brand name Alacare®) is an approved medicinal product for the treatment of AK located on scalp and face. It is a self-adhesive, light-proof patch loaded with 5-ALA HCl and was developed for easy handling. AK located on arms, hands or trunk do not respond as well to ALA-PDT as AK lesions on the head do. It has been reported that occlusion during ALA incubation can improve clinical outcome after ALA-PDT for AK on hands and arms. We present the results of a first explorative pilot study involving 20 participants with a total of 145 treated (122 evaluable) AK lesions. The trial investigated the conduct of two ALA-PDTs within 1-2 weeks and involved all severity grades of AK. The model-based percentage of complete clearance on lesion-basis was estimated being 78.0% (95%-CI: [64.6%, 87.3%]), and the by-participant calculation (patient-based clearance) led to similar results (78.7% with a 95%-CI of [67.0%, 90.3%]). The treatment was well tolerated. Local reactions during ALA patch incubation were rare whereas nearly all patients showed the expected reactions during or after the illumination, primarily erythema and pain. The study results indicate that two PD P 506 A-PDT sessions 1-2 weeks apart are an efficacious treatment for AK on hands and arms. Especially mild but also moderate lesions responded very well to PDT treatment involving ALA incubation under occlusion.

Longitudinal analysis reveals age-related changes in the T cell receptor repertoire of human T cell subsets

A diverse T cell receptor (TCR) repertoire is essential for protection against a variety of pathogens, and TCR repertoire size is believed to decline with age. However, the precise size of human TCR repertoires, in both total and subsets of T cells, as well as their changes with age, are not fully characterized. We conducted a longitudinal analysis of the human blood TCRα and TCRβ repertoire of CD4⁺ and CD8⁺ T cell subsets using a unique molecular identifier–based (UMI-based) RNA-seq method. Thorough analysis of 1.9 × 10⁸ T cells yielded the lower estimate of TCR repertoire richness in an adult at 3.8 × 10⁸. Alterations of the TCR repertoire with age were observed in all 4 subsets of T cells. The greatest reduction was observed in naive CD8⁺ T cells, while the greatest clonal expansion was in memory CD8⁺ T cells, and the highest increased retention of TCR sequences was in memory CD8⁺ T cells. Our results demonstrated that age-related TCR repertoire attrition is subset specific and more profound for CD8⁺ than CD4⁺ T cells, suggesting that aging has a more profound effect on cytotoxic as opposed to helper T cell functions. This may explain the increased susceptibility of older adults to novel infections.

Subset distinct richness reduction and clonal expansion of human CD4+ and CD8+ αβ TCR repertoires with aging

A competent T-cell receptor (TCR) repertoire contains TCRs recognizing both novel and experienced antigens. It is widely believed that the human TCR repertoire declines with age, but its precise change in size and clonal distribution with age has not been fully determined. Here, we investigated how the size and content of TCR repertoire changes with age by analyzing the TCR repertoire of human CD4+ and CD8+ T cells and their naïve and memory subsets from 30 healthy adults aged from 25 to 85 at first visit and an average of 9-year follow-up as second visit by RNAseq. First, we calculated abTCR repertoire changes with age and found a profound reduction of the TCRa and TCRb richness in naïve CD8+ T cells and an increase of clonal expansion especially in memory CD8 T cells compared to CD4+ T cells. We also study the degree of overlap of TCRa/b repertoire between naïve and memory T cells in each subject at the same visit and found little overlap of TCRa/b unique sequences between naïve and memory CD4 T cells and ~40% of the total TCRs in CD8 T cells. Moreover, we showed elevated overlap of TCR sequences between two visits in both CD4 and CD8 T cells with memory CD8 T cells as the highest. Finally, we determined the degree of TCR clonotypes shares among different subjects via the analysis of the sharing of TCR sequences in the 30 healthy adults. As results, we observed increased sharing of identical TCR between CD4 and CD8 T cells suggesting that the public clonotypes may share with the common pathogens shared in the population, particularly in the old population. Our findings showed more profound reduction in the CD8+TCR repertoire with age compared to CD4+ TCR repertoire. All together provide evidence of ab TCR sequence-based age-associated changes of T cells and their subsets.

TCR Repertoires of Thymic Conventional and Regulatory T Cells: Identification and Characterization of Both Unique and Shared TCR Sequences

Thymic regulatory T cells (tTreg) are critical in the maintenance of normal T cell immunity and tolerance. The role of TCR in tTreg selection remains incompletely understood. In this study, we assessed TCRα and TCRβ sequences of mouse tTreg and thymic conventional CD4⁺ T cells (Tconv) by high-throughput sequencing. We identified αβ TCR sequences that were unique to either tTreg or Tconv and found that these were distinct as recognized by machine learning algorithm and by preferentially used amino acid trimers in αβ CDR3 of tTreg. In addition, a proportion of αβ TCR sequences expressed by tTreg were also found in Tconv, and machine learning classified the great majority of these shared αβ TCR sequences as characteristic of Tconv and not tTreg. These findings identify two populations of tTreg, one in which the regulatory T cell fate is associated with unique properties of the TCR and another with TCR properties characteristic of Tconv for which tTreg fate is determined by factors beyond TCR sequence.

Identifying barriers to healthcare delivery and access in the Circumpolar North: important insights for health professionals

Lack of access to healthcare services for people living in the Circumpolar North may have important consequences for their health and well-being, both in terms of the actual treatment and other possible health-related consequences intertwined with their life situation. The aim of the present study was to identify the specific challenges to healthcare service delivery and access for populations in the Circumpolar North that are addressed in contemporary literature. A scoping review of literature published between 2005 and 2016 was conducted and 43 articles were selected for inclusion into the review. The review findings address 4 main themes identified in the literature: (1) the influence of physical geography, (2) healthcare provider-related barriers, (3) the importance of culture and language and (4) the impact of systemic factors. The review of the literature enabled us to identify existing gaps in both health service access and issues discussed in the available literature, particularly for informing healthcare services in the Circumpolar North, as well as point towards opportunities for future research. The thematic findings drawn from interdisciplinary and international literature inform understandings of the impact of health system barriers on healthcare services and the opportunities for Northern residents to support their own health.

Comparison of the diagnostic performance of the 2017 and 2018 versions of LI-RADS for hepatocellular carcinoma on gadoxetic acid enhanced MRI

AIM

To compare the diagnostic performance of the 2017 (v2017) and 2018 versions (v2018) of the Liver Imaging-Reporting and Data System (LI-RADS) for hepatocellular carcinoma (HCC) using gadoxetic acid-enhanced magnetic resonance imaging (Gd-EOB-MRI) and to evaluate the effect in v2018.

MATERIALS AND METHODS

Treatment-naive patients at high-risk for HCC who underwent Gd-EOB-MRI were included. The LI-RADS categories were assigned according to v2017 and v2018. The diagnostic performances were compared between v2017 and v2018 according to the size and combination of imaging features.

RESULTS

A total of 117 patients with 137 observations were identified, including 89 HCCs; 76.2% (64/84) of observations with threshold growth were re-classified as subthreshold growth when using v2018 instead of v2017. The final categories changed in nine (14%) cases. For the combination of LR-5/LR-5V, there were no significant differences in sensitivity and specificity between the two versions (sensitivity, 64% versus 58.4%; specificity, 87.5% versus 85.4%; all p>0.05). For the combination of LR-4 and LR-5/5V, the diagnostic performance of v2018 was inferior to that of v2017 when considering only major features (accuracy, 86.1% versus 80.3%, respectively; p=0.013), particularly in observations measuring 10-20 mm, but was comparable after adding the ancillary features (accuracy, 86.9% versus 86.1%, respectively; p=1.00).

CONCLUSION

In LI-RADS v2018, although a considerable number of observations re-classified subthreshold growth, changes in the assigned categories were insignificant; overall diagnostic performance was comparable to that of v2017, but v2018 might emphasise the value of ancillary features in combination with major features for determining the probability of HCC.

Sequence and Structural Analyses Reveal Distinct and Highly Diverse Human CD8+ TCR Repertoires to Immunodominant Viral Antigens

A diverse T cell receptor (TCR) repertoire is essential for controlling viral infections. However, information about TCR repertoires to defined viral antigens is limited. We performed a comprehensive analysis of CD8⁺ TCR repertoires for two dominant viral epitopes: pp65_495-503 (NLV) of cytomegalovirus and M1_58-66 (GIL) of influenza A virus. The highly individualized repertoires (87-5,533 α or β clonotypes per subject) comprised thousands of unique TCRα and TCRβ sequences and dozens of distinct complementary determining region (CDR)3α and CDR3β motifs. However, diversity is effectively restricted by preferential V-J combinations, CDR3 lengths, and CDR3α/CDR3β pairings. Structures of two GIL-specific TCRs bound to GIL-HLA-A2 provided a potential explanation for the lower diversity of GIL-specific versus NLV-specific repertoires. These anti-viral TCRs occupied up to 3.4% of the CD8⁺ TCRβ repertoire, ensuring broad T cell responses to single epitopes. Our portrait of two anti-viral TCR repertoires may inform the development of predictors of immune protection.

Distinct features of human CD8 T cell TCR repertoire specific to influenza A virus matrix protein M1

CD8 T cells play a vital role in the immune response to viral infection. Diversity of the T cell antigen receptor (TCR) is believed to be essential for the host to survive in this microorganism-rich world. However, there is limited information regarding the characteristics of the TCR repertoire to defined viral antigens in humans. Here, we report a comprehensive analysis of CD8 TCR repertoire diversity (size, V and J gene usage), the consensus binding motifs in CDR3, affinity, and structure of selected a/b paired TCRs to influenza A virus matrix protein M1 (GILGFVFTL, GIL) on HLA-A2+ healthy individuals. Using high-throughput sequencing coupled with the unique molecular identifier (UMI) method, we identified several hundred GIL-binding TCRa and TCRb. TRAV13-1 (63.2%) and TRAJ42 (72.5%) were most frequently found in alpha chain whereas TRBV19 (94.9%) and TRBJ2-5 (54.8%) were frequently found in beta chain. Furthermore, the length of the CDR3 amino acid region was highly restricted with over 70% of alpha (10) and of beta (11). CDR3 sequence analysis revealed shared motifs among different TCRs (a and b chains). We isolated paired expressed TCRa/b from single cells for further structural analysis. The affinity between TCRs and GIL-HLA-A2 complexes showed a wide range (1.8–191 mM). Finally, we resolved two crystal structures of TCRs-GIL-HLA-A2 complexes and found that the TCRs exhibited similar patterns of interactions with the antigen, even though the V, J, and CDR3 lengths were different. Together, our findings revealed the size of the antigen-specific CD8 TCR repertoire, the consensus binding motifs in CDR3, binding affinity of TCR and pMHC, and shared patterns of TCR-pMHC interactions.

CA19-9 decrease at 8 weeks as a predictor of overall survival in a randomized phase III trial (MPACT) of weekly nab-paclitaxel plus gemcitabine versus gemcitabine alone in patients with metastatic pancreatic cancer

Any CA19-9 decline at week 8 and radiologic response by week 8 each predicted longer OS in both treatment arms. In the nab-P + Gem arm, the higher proportion of patients with week 8 CA19-9 decrease [82% (206/252); median OS 13.2 months] than a RECIST-defined response [16% (40/252); median OS 13.7 months] suggests that CA19-9 decline is a predictor of OS applicable to a larger population.

Background

A phase I/II study and subsequent phase III study (MPACT) reported significant correlations between CA19-9 decreases and prolonged overall survival (OS) with nab-paclitaxel plus gemcitabine (nab-P + Gem) treatment for metastatic pancreatic cancer (MPC). CA19-9 changes at week 8 and potential associations with efficacy were investigated as part of an exploratory analysis in the MPACT trial.

Patients and methods

Untreated patients with MPC (N = 861) received nab-P + Gem or Gem alone. CA19-9 was evaluated at baseline and every 8 weeks.

Results

Patients with baseline and week-8 CA19-9 measurements were analyzed (nab-P + Gem: 252; Gem: 202). In an analysis pooling the treatments, patients with any CA19-9 decline (80%) versus those without (20%) had improved OS (median 11.1 versus 8.0 months; P = 0.005). In the nab-P + Gem arm, patients with (n = 206) versus without (n = 46) any CA19-9 decrease at week 8 had a confirmed overall response rate (ORR) of 40% versus 13%, and a median OS of 13.2 versus 8.3 months (P = 0.001), respectively. In the Gem-alone arm, patients with (n = 159) versus without (n = 43) CA19-9 decrease at week 8 had a confirmed ORR of 15% versus 5%, and a median OS of 9.4 versus 7.1 months (P = 0.404), respectively. In the nab-P + Gem and Gem-alone arms, by week 8, 16% (40/252) and 6% (13/202) of patients, respectively, had an unconfirmed radiologic response (median OS 13.7 and 14.7 months, respectively), and 79% and 84% of patients, respectively, had stable disease (SD) (median OS 11.1 and 9 months, respectively). Patients with SD and any CA19-9 decrease (158/199 and 133/170) had a median OS of 13.2 and 9.4 months, respectively.

Conclusion

This analysis demonstrated that, in patients with MPC, any CA19-9 decrease at week 8 can be an early marker for chemotherapy efficacy, including in those patients with SD. CA19-9 decrease identified more patients with survival benefit than radiologic response by week 8.

Autophagy inhibition radiosensitizes in vitro, yet reduces radioresponses in vivo due to deficient immunogenic signalling

Clinical oncology heavily relies on the use of radiotherapy, which often leads to merely transient responses that are followed by local or distant relapse. The molecular mechanisms explaining radioresistance are largely elusive. Here, we identified a dual role of autophagy in the response of cancer cells to ionizing radiation. On one hand, we observed that the depletion of essential autophagy-relevant gene products, such as ATG5 and Beclin 1, increased the sensitivity of human or mouse cancer cell lines to irradiation, both in vitro (where autophagy inhibition increased radiation-induced cell death and decreased clonogenic survival) and in vivo, after transplantation of the cell lines into immunodeficient mice (where autophagy inhibition potentiated the tumour growth-inhibitory effect of radiotherapy). On the other hand, when tumour proficient or deficient for autophagy were implanted in immunocompetent mice, it turned out that defective autophagy reduced the efficacy of radiotherapy. Indeed, radiotherapy elicited an anti-cancer immune response that was dependent on autophagy-induced ATP release from stressed or dying tumour cells and was characterized by dense lymphocyte infiltration of the tumour bed. Intratumoural injection of an ecto-ATPase inhibitor restored the immune infiltration of autophagy-deficient tumours post radiotherapy and improved the growth-inhibitory effect of ionizing irradiation. Altogether, our results reveal that beyond its cytoprotective function, autophagy confers immunogenic properties to tumours, hence amplifying the efficacy of radiotherapy in an immunocompetent context. This has far-reaching implications for the development of pharmacological radiosensitizers.

Application of biomarkers in the development of drugs intended for the treatment of osteoarthritis

OBJECTIVE

Osteoarthritis (OA) is a chronic and slowly progressive disease for which biomarkers may be able to provide a more rapid indication of therapeutic responses to therapy than is currently available; this could accelerate and facilitate OA drug discovery and development programs. The goal of this document is to provide a summary and guide to the application of in vitro (biochemical and other soluble) biomarkers in the development of drugs for OA and to outline and stimulate a research agenda that will further this goal.

METHODS

The Biomarkers Working Group representing experts in the field of OA biomarker research from both academia and industry developed this consensus document between 2007 and 2009 at the behest of the Osteoarthritis Research Society International Federal Drug Administration initiative (OARSI FDA initiative).

RESULTS

This document summarizes definitions and classification systems for biomarkers, the current outcome measures used in OA clinical trials, applications and potential utility of biomarkers for development of OA therapeutics, the current state of qualification of OA-related biomarkers, pathways for biomarker qualification, critical needs to advance the use of biomarkers for drug development, recommendations regarding practices and clinical trials, and a research agenda to advance the science of OA-related biomarkers.

CONCLUSIONS

Although many OA-related biomarkers are currently available they exist in various states of qualification and validation. The biomarkers that are likely to have the earliest beneficial impact on clinical trials fall into two general categories, those that will allow targeting of subjects most likely to either respond and/or progress (prognostic value) within a reasonable and manageable time frame for a clinical study (for instance within 1-2 years for an OA trial), and those that provide early feedback for preclinical decision-making and for trial organizers that a drug is having the desired biochemical effect. As in vitro biomarkers are increasingly investigated in the context of specific drug treatments, advances in the field can be expected that will lead to rapid expansion of the list of available biomarkers with increasing understanding of the molecular processes that they represent.

Hdm2 negatively regulates telomerase activity by functioning as an E3 ligase of hTERT

In this study, we identified posttranslational regulation of human telomerase reverse-transcriptase (hTERT) by the E3 ligase Hdm2. The telomerase activity generated by exogenous hTERT in U2OS cells was reduced on adriamycin treatment. The overexpressed levels of hTERT were also decreased under the same conditions. These processes were reversed by treatment with a proteasome inhibitor or depletion of Hdm2. Furthermore, intrinsic telomerase activity was increased in HCT116 cells with ablation of Hdm2. Immunoprecipitation analyses showed that hTERT and Hdm2 bound to each other in multiple domains. Ubiquitination analyses showed that Hdm2 could polyubiquitinate hTERT principally at the N-terminus, which was further degraded in a proteasome-dependent manner. An hTERT mutant with all five lysine residues at the N-terminus of hTERT that mutated to arginine became resistant to Hdm2-mediated ubiquitination and degradation. In U2OS cells, depletion of Hdm2 or addition of the Hdm2-resistant hTERT mutant strengthened the cellular protective effects against apoptosis. Similar results were obtained with the Hdm2-stable H1299 cell line. These observations indicate that Hdm2 is an E3 ligase of hTERT.

Rescue of a living donor with liver transplantation

Postoperative liver failure is a rare complication after living donor liver resection. This is a case report of a 22-year-old healthy donor who was rescued with liver transplantation 11 days after right hemihepatectomy. Nine months later the patient is alive, and has fully recovered from his multiple organ failure. According to a review of the literature, there are four additional living liver donors, who received a liver transplant. Our own patient is the only survivor, so far. This case demonstrates that even in supposedly healthy living donors postoperative complications cannot be completely prevented. Although liver failure is rare in these patients, timely transplantation may need to be considered as the only life-saving treatment.

A randomized placebo-controlled trial comparing the efficacy of etoricoxib 30 mg and ibuprofen 2400 mg for the treatment of patients with osteoarthritis

OBJECTIVE

We compared the efficacy of etoricoxib 30 mg to placebo and ibuprofen 2400 mg for the treatment of osteoarthritis (OA) of the hip and knee.

DESIGN

In this 12-week, randomized, double-blind, placebo- and active-comparator-controlled trial, 548 patients (median age 63 years) with OA of the hip or knee were randomized to receive placebo, etoricoxib 30 mg q.d., or ibuprofen 800 mg t.i.d. Demonstration of etoricoxib's efficacy vs placebo and comparison of its efficacy to ibuprofen were assessed using three co-primary endpoints: Western Ontario and McMaster's University Osteoarthritis Index (WOMAC) Pain Subscale (WOMAC-PS); WOMAC Physical Function Subscale (WOMAC-PFS); and Patient Global Assessment of Disease Status (PGADS). Each primary endpoint utilizes a 0-100 mm visual analog scale. To demonstrate comparable efficacy of etoricoxib vs ibuprofen, the 95% confidence intervals (CIs) for the difference in the least squares (LS) mean change over 12 weeks for all three co-primary endpoints had to fall within +/-10 mm. Safety and tolerability data were collected throughout the study.

RESULTS

Mean baseline values for the three co-primary endpoints ranged from 62.52 to 70.14 mm. Both etoricoxib and ibuprofen demonstrated superior (P< or =0.002) efficacy for all primary endpoints. The LS mean (mm) changes (95% CI) over 12 weeks for etoricoxib and ibuprofen, respectively, compared to placebo were given as follows: WOMAC-PS: -11.66 (-16.31, -7.01) and -7.62 (-12.30, -2.94); WOMAC-PFS: -10.15 (-14.74, -5.57) and -7.23 (-11.85, -2.61); PGADS: -11.65 (-16.81, -6.50) and -8.11 (-13.30, -2.92). The efficacy of etoricoxib 30 mg was comparable to ibuprofen 2400 mg. All treatments were similarly well tolerated.

CONCLUSION

Treatment with etoricoxib 30 mg q.d. provides superior efficacy vs placebo and comparable clinical efficacy vs ibuprofen 2400 mg (800 mg t.i.d.) for the treatment of OA of the hip and knee.

Effects of ibuprofen on molecular markers of cartilage and synovium turnover in patients with knee osteoarthritis

OBJECTIVE

The aim of this study was to evaluate the effect of ibuprofen on the urinary excretion of C-terminal crosslinking telopeptide of type II collagen (CTX-II) and urinary glucosyl galactosyl pyridinoline (Glc-Gal-PYD), two new molecular markers of cartilage and synovial tissue metabolism, respectively, in patients with knee osteoarthritis (OA).

METHODS

We studied 201 patients with knee pain and radiographic evidence of knee OA who were on treatment with non-steroidal anti-inflammatory drugs (NSAIDs) prior to study initiation. After an initial screening visit, patients were withdrawn from their pre-study NSAID and, following a flare of their OA symptoms, were randomised to ibuprofen (2400 mg/day) or placebo. Urinary CTX-II and Glc-Gal-PYD levels were measured at time of randomisation (baseline) and after 4-6 weeks of treatment.

RESULTS

After 4 to 6 weeks, urinary CTX-II (+17%, p = 0.023) and Glc-Gal-PYD (+10%, p = 0.020) increased significantly from baseline in the placebo group whereas marginal or no increase was observed in the ibuprofen group (CTX-II +2%, NS and Glc-Gal-PYD +4%, p = 0.045). For urinary CTX-II, the difference in the change from baseline between placebo and ibuprofen treated groups was significant (13%, p = 0.017). At baseline, urinary levels of CTX-II and Glc-Gal-PYD were higher in patients with knee swelling (n = 127) than in those without (n = 74) (p<0.02 for both markers). When patients were stratified according to presence or absence of knee swelling at baseline, the increases over 4-6 weeks of urinary CTX-II and Glc-Gal-PYD in the placebo group were restricted to patients with knee swelling (+22% from baseline, p = 0.001 and +12%, p = 0.011, for urinary CTX-II and Glc-Gal-PYD respectively). In patients with knee swelling who were treated with ibuprofen this increase was not observed and the difference from placebo was significant for urinary CTX-II (p = 0.014).

CONCLUSION

In patients with a flare of knee OA, specifically in patients with evidence of joint inflammation documented by knee swelling, there was a significant increase in markers reflecting cartilage and synovium metabolism that could partly be prevented by high doses of ibuprofen. These data suggest that patients with a flare of knee OA are characterised by increased cartilage and synovial tissue degradation, which may be partly prevented by high doses of NSAIDs.

Results of a randomized, dose-ranging trial of etoricoxib in patients with osteoarthritis

OBJECTIVES

To evaluate the clinical efficacy and tolerability of etoricoxib in the treatment of osteoarthritis (OA) of the knee and define the clinically active dose range for further clinical trials.

METHODS

This two-part, randomized, double-blind, placebo- and active comparator-controlled trial was conducted in 617 adults with knee OA. In Part 1 (6 weeks), patients received placebo, etoricoxib 5, 10, 30, 60 or 90 mg q.d. In Part 2 (8 weeks), patients received etoricoxib 30, 60 or 90 mg q.d. or diclofenac 50 mg t.i.d., predetermined at Part 1 allocation. Efficacy and safety were evaluated. Primary efficacy end-points were the Western Ontario and McMaster's University Osteoarthritis Index (WOMAC) Pain subscale, Patient Global Assessment of Response to Therapy, and Investigator Global Assessment of Disease Status.

RESULTS

At 6 weeks, etoricoxib 5, 10, 30, 60 and 90 mg each demonstrated clinical efficacy superior to placebo. Maximal efficacy was seen with 60 mg. In Part 2, etoricoxib 30, 60 and 90 mg were generally similar to diclofenac. Patients receiving etoricoxib 30, 60 or 90 mg in Parts I and II had sustained effects over 14 weeks. All treatments were well tolerated.

CONCLUSIONS

Etoricoxib 60 mg once daily showed maximal efficacy in treating OA in this study. Etoricoxib 5-90 mg once daily was generally well tolerated in OA patients for up to 14 weeks.

Pulmonary embolism presenting as disseminated intravascular coagulation

We report an unusual case of disseminated intravascular coagulation. Occult pulmonary embolism is a recognised cause of disseminated intravascular coagulation. Unexplained shock should prompt the physician to search for a thrombotic cause such as pulmonary thromboembolism.

A canine model of gastroesophageal reflux disease (GERD)

BACKGROUND

Although a variety of antireflux procedures and medications are used to treat gastroesophageal reflux disease (GERD), reliable large-animal models of GERD that can be used to objectively compare the efficacy of these treatments are lacking.

METHODS

Esophageal manometry and 24-h gastroesophageal pH monitoring with event data were performed in 18 mongrel dogs with a cervical esophagopexy. We then calculated a modified DeMeester score: The Duke Canine reflux score (DCR). Thereafter, the animals underwent a 4-cm anterior distal esophageal myotomy, incision of the left diaphragmatic crus, and intrathoracic gastric cardiopexy. Postoperative 24-h pH and manometry were obtained 2 weeks later.

RESULTS

The postoperative 24-h pH results showed a significant increase in the mean DCR score (5.9 +/- 4.5 vs 84.9 +/- 56.1, p < 0.0002), and manometry indicated a significant decrease in mean lower esophageal sphincter (LES) pressure (7.1 +/- 2.9 vs 3.2 +/- 2.5 mmHg, p < 0.0001).

CONCLUSION

This technique reliably creates a canine model of GERD.

Radiation after mastectomy in high-risk patients: is it necessary?

A retrospective review of cases from 1988 through 1992 was performed examining high-risk breast cancer patients treated with modified radical mastectomy without postoperative radiation at a single institution. Locoregional recurrence, distant metastases, overall survival, and number of lymph nodes removed were examined. This was compared with recent Danish and Canadian studies. Thirty-three premenopausal node-positive breast cancer patients had a 9 per cent locoregional recurrence rate. In the Danish and Canadian studies the locoregional recurrence rates were 32 and 21 per cent. These were reduced to 9 per cent and 10 per cent respectively in the radiated arms. Our locoregional recurrence in nonradiated patients was similar to that in the radiated arms of the studies and improved when compared with recurrence in their non-radiated controls. The adequacy of the axillary lymph node dissection was examined. In the current study a median of 18 lymph nodes were recovered with only 3 per cent containing less than 12 nodes. In the Danish study a median of seven lymph nodes were removed. Similarly in the Canadian trial a median of 11 nodes were removed. With complete axillary dissection results equivalent to those of postoperative adjuvant radiation is achieved. Further randomized controlled studies with standard axillary dissections are needed before the recommendation of routine postoperative radiotherapy.

Histologic evaluation of fetal brains following maternal pneumoperitoneum

BACKGROUND

The purpose of this study was to determine if maternal pneumoperitoneum with carbon dioxide (CO2) produces evidence of central nervous system (CNS) injury in preterm fetal guinea pigs.

METHODS

Thirty pregnant guinea pigs at gestational day (GD) 45 were assigned at random to one of three treatment groups: anesthesia only, CO2 pneumoperitoneum (5 mmHg), or laparotomy. Dams were killed 3 or 5 days postprocedure and fetal brains (83 total) harvested and fixed for subsequent histopathologic evaluation. For comparative purposes, histologic features of fetal guinea pig brain injury were defined from examination of fetal brains harvested from an additional dam that underwent laparotomy with 20 min of uterine arterial occlusion.

RESULTS

Carbon dioxide pneumoperitoneum did not increase maternal/fetal morbidity. No evidence of brain injury was found in fetuses from any of the treatment groups.

CONCLUSION

Carbon dioxide pneumoperitoneum at 5 mmHg for 40 min in the pregnant guinea pig does not produce evidence of fetal brain injury.

A canine model of gastroesophageal reflux disease (GERD)

BACKGROUND

Although a variety of antireflux procedures and medications are used to treat gastroesophageal reflux disease (GERD), reliable large-animal models of GERD that can be used to objectively compare the efficacy of these treatments are lacking.

METHODS

Esophageal manometry and 24-h gastroesophageal pH monitoring with event data were performed in 18 mongrel dogs with a cervical esophagopexy. We then calculated a modified DeMeester score: The Duke Canine reflux score (DCR). Thereafter, the animals underwent a 4-cm anterior distal esophageal myotomy, incision of the left diaphragmatic crus, and intrathoracic gastric cardiopexy. Postoperative 24-h pH and manometry were obtained 2 weeks later.

RESULTS

The postoperative 24-h pH results showed a significant increase in the mean DCR score (5.9 +/- 4.5 vs 84.9 +/- 56.1, p < 0.0002), and manometry indicated a significant decrease in mean lower esophageal sphincter (LES) pressure (7.1 +/- 2.9 vs 3.2 +/- 2.5 mmHg, p < 0.0001).

CONCLUSION

This technique reliably creates a canine model of GERD.

Anti-beta2 glycoprotein I and anticardiolipin antibodies in leptospirosis, syphilis and Kala-azar

OBJECTIVE

Reports have shown that anticardiolipin (aCL) antibodies present in patients with autoimmune diseases are dependent on the cofactor,beta2 glycoprotein I (beta2 GPI), as opposed to aCL antibodies seen in infectious diseases such as syphilis, HIV hepatitis C, etc. The assay for anti-beta2GPI antibodies has been reported to be more specific for antiphospholipid syndrome (APS). However, the prevalence of these antibodies in diseases such as leishmaniasis and leptospirosis remains unknown. The aim of the present study was determine the prevalence of antibodies to cardiolipin and to beta2GPI in patients with different infectious diseases, including leptospirosis, syphilis and leishmaniasis.

METHODS

Samples from patients with Kala-azar (visceral leishmaniasis), syphilis or leptospirosis were tested for IgG and IgM anticardiolipin and IgG anti-beta2GPI antibodies by ELISA.

RESULTS

In patients with Kala-azar the prevalence of IgG aCL, IgM aCL and anti-beta2GPI was 6% (2/30), 3% (1/30) and 53% (16/30), respectively. In syphilis the prevalence was 18% (14/74), 13% (10/74) and 10% (8/70), respectively. In leptospirosis the frequency of these antibodies was 23% (9/39), 10% (4/39) and 17% (6/34), respectively. There was no statistical correlation between aCL and anti-beta2GPI antibodies in these diseases.

DISCUSSION

This study clearly shows a significant prevalence of anti-beta2GPI antibodies in leptospirosis and leishmaniasis and syphilis. This indicates that the assay for antibeta2GPI antibodies should be thoroughly validated before it is introduced as a definitive tool for the diagnosis of APS, testing a larger number of sera from patients with a wider range of clinical conditions.

CTLA-4 blockade enhances the CTL responses to the p53 self-tumor antigen

p53 is an attractive target for cancer immunotherapy because it is overexpressed in a high proportion of many different types of tumors. However, it is also expressed in normal tissues and acts as a toleragen in vivo. Previously, detailed examination of the repertoire specific for the murine p53(261-269) epitope in conventional and p53-deficient mice demonstrated that because of expression of p53, the CD8(+) T cells that respond to this epitope express low-affinity TCRs. It has been reported that tolerance to tumor Ags can be broken by in vivo administration of anti-CTLA-4 mAb. With the goal of overriding tolerance and achieving optimal activation of p53-specific CTL, the current study has assessed the effect of anti-CTLA-4 mAb on the p53-specific repertoire. It was found that blockade of CTLA-4 engagement at the time of antigenic stimulation induced a vigorous amplification of the CTL responses to p53 as well as proportionate expansion of the memory T cell pool. This effect was dependent on the presence of CD4(+) T cell help and correlated with an enhancement of helper function. However, anti-CTLA-4 treatment did not enhance the avidity of the resultant p53-specific CTL populations and, therefore, could not reverse this important consequence of tolerance.

The effect of rofecoxib on the pharmacodynamics and pharmcokinetics of warfarin

OBJECTIVE

The objective of this study was to examine the effect of 3 doses of rofecoxib (12.5, 25, and 50 mg) on the pharmacodynamics and pharmacokinetics of warfarin.

METHODS

Two single-dose (12.5 or 50 mg of rofecoxib with 25 mg or 30 mg of oral warfarin, respectively, on day 7 of each period) trials (N = 12 men) and 1 steady-state warfarin trial (25 mg rofecoxib; N = 15, 13 men and 2 women) were completed as two-period, randomized, balanced, crossover, double-blind designs. The prothrombin time international normalized ratio (INR) and S(-) and R(+) warfarin enantiomers were assessed during 144 hours after the single warfarin doses. In the steady-state warfarin trial, after the attainment of a stable INR (1.4-1.7), the stable warfarin dose was co-administered with rofecoxib (25 mg) and placebo over two 21-day periods. After the dose of warfarin on day 21, INR and S(-) and R(+) warfarin were assessed during 24 hours.

RESULTS

Compared with placebo, rofecoxib slightly increased the INR by approximately 5% (90% confidence interval on the geometric ratio, 1.03, 1.08) and 11% (1.04, 1.19) for the two single-dose warfarin trials with 12.5 and 50 mg of rofecoxib, respectively. In the steady-state warfarin study with 25 mg of rofecoxib, the INR was increased by 8% (1.02, 1.15). Rofecoxib had no significant effect (versus placebo) on the pharmacokinetics of S(-) warfarin. However, in the 3 studies, treatment with 12.5, 25, and 50 mg of rofecoxib was associated with a 27%, 38%, and 40% increase in the area under the plasma concentration-time curve of the biologically less active R(+) warfarin.

CONCLUSIONS

Rofecoxib increased plasma concentrations of the biologically less active R(+) warfarin, which accounted for a small increase in INR. The approximately 8% increase in INR at steady state with warfarin co-administered with 25 mg of rofecoxib is not likely to be clinically important in most patients taking warfarin. However, standard monitoring of INR values should be conducted when therapy with rofecoxib is initiated or changed, particularly in the first few days, for patients receiving warfarin.