Acid-base and electrolyte evaluation in dogs with upper GI obstruction: 115 dogs (2015-2021)

OBJECTIVES

Metabolic alkalosis, although uncommon in small animals, has been previously associated with gastrointestinal obstructions. Depending on the population and disease process evaluated, previous prevalence of metabolic alkalosis is reported as ranging from 2% to 45% in canine patients. The objective of this study was to determine the prevalence of metabolic alkalosis and other acid-base and electrolyte disorders in a cohort of dogs with a confirmed upper gastrointestinal obstruction.

MATERIALS AND METHODS

Electronic medical records were reviewed to identify dogs who presented for vomiting with evidence of an upper gastrointestinal obstruction from January 2015 to October 2021. Patients were enrolled only if a preoperative venous blood gas was obtained and analysed in house. Traditional acid-base analysis was utilised to determine an acid-base status before relieving the obstruction. When available, post-operative venous acid-base status was determined within 24 hours after surgery, and compared to preoperative results.

RESULTS

A total of 115 dogs were included in the study. Twenty-five out of 115 (22%) dogs displayed either a simple metabolic alkalosis or a mixed acid-base disturbance before surgery. Twenty-seven out of 115 dogs (37%) had a normal acid-base status at entry. Seventy-one dogs had pre- and post-operative venous blood gas results available. Metabolic alkalosis was resolved in nearly all patients post-operatively, with no patients displaying a simple metabolic alkalosis. A mixed metabolic acidosis and respiratory alkalosis was the most common condition post-operatively, found in 25 of 71 (35%) dogs. Severe derangements of electrolytes were infrequent preoperatively (3/115; 2.6%). A majority of patients in this study exhibited hypokalaemia (64.4%), hypochloraemia (72.8%) and hyponatraemia (77.4%) on preoperative venous blood gases. Venous pH, Pv CO2 , bicarbonate and base excess were significantly higher preoperatively when compared to the post-operative results.

CLINICAL SIGNIFICANCE

This study found the prevalence of pre-operative metabolic alkalosis in dogs with a documented upper gastrointestinal obstruction to be lower than previously reported. Surgical or endoscopic alleviation of the upper gastrointestinal obstruction resulted in resolution of metabolic alkalosis in nearly all patients.

Results of the c-TRAK TN trial: a clinical trial utilising ctDNA mutation tracking to detect molecular residual disease and trigger intervention in patients with moderate- and high-risk early-stage triple-negative breast cancer

BACKGROUND

Post-treatment detection of circulating tumour DNA (ctDNA) in early-stage triple-negative breast cancer (TNBC) patients predicts high risk of relapse. c-TRAK TN assessed the utility of prospective ctDNA surveillance in TNBC and the activity of pembrolizumab in patients with ctDNA detected [ctDNA positive (ctDNA+)].

PATIENTS AND METHODS

c-TRAK TN, a multicentre phase II trial, with integrated prospective ctDNA surveillance by digital PCR, enrolled patients with early-stage TNBC and residual disease following neoadjuvant chemotherapy, or stage II/III with adjuvant chemotherapy. ctDNA surveillance comprised three-monthly blood sampling to 12 months (18 months if samples were missed due to coronavirus disease), and ctDNA+ patients were randomised 2 : 1 to intervention : observation. ctDNA results were blinded unless patients were allocated to intervention, when staging scans were done and those free of recurrence were offered pembrolizumab. A protocol amendment (16 September 2020) closed the observation group; all subsequent ctDNA+ patients were allocated to intervention. Co-primary endpoints were (i) ctDNA detection rate and (ii) sustained ctDNA clearance rate on pembrolizumab (NCT03145961).

RESULTS

Two hundred and eight patients registered between 30 January 2018 and 06 December 2019, 185 had tumour sequenced, 171 (92.4%) had trackable mutations, and 161 entered ctDNA surveillance. Rate of ctDNA detection by 12 months was 27.3% (44/161, 95% confidence interval 20.6% to 34.9%). Seven patients relapsed without prior ctDNA detection. Forty-five patients entered the therapeutic component (intervention n = 31; observation n = 14; one observation patient was re-allocated to intervention following protocol amendment). Of patients allocated to intervention, 72% (23/32) had metastases on staging at the time of ctDNA+, and 4 patients declined pembrolizumab. Of the five patients who commenced pembrolizumab, none achieved sustained ctDNA clearance.

CONCLUSIONS

c-TRAK TN is the first prospective study to assess whether ctDNA assays have clinical utility in guiding therapy in TNBC. Patients had a high rate of metastatic disease on ctDNA detection. Findings have implications for future trial design, emphasising the importance of commencing ctDNA testing early, with more sensitive and/or frequent ctDNA testing regimes.

Evolution of vertebrate respiratory central rhythm generators

Tracing the evolution of the central rhythm generators associated with ventilation in vertebrates is hindered by a lack of information surrounding key transitions. To begin with, central rhythm generation has been studied in detail in only a few species from four vertebrate groups, lamprey, anuran amphibians, turtles, and mammals (primarily rodents). Secondly, there is a lack of information regarding the transition from water breathing fish to air breathing amniotes (reptiles, birds, and mammals). Specifically, the respiratory rhythm generators of fish appear to be single oscillators capable of generating both phases of the respiratory cycle (expansion and compression) and projecting to motoneurons in cranial nerves innervating bucco-pharyngeal muscles. In the amniotes we find oscillators capable of independently generating separate phases of the respiratory cycle (expiration and inspiration) and projecting to pre-motoneurons in the ventrolateral medulla that in turn project to spinal motoneurons innervating thoracic and abdominal muscles (reptiles, birds, and mammals). Studies of the one group of amphibians that lie at this transition (the anurans), raise intriguing possibilities but, for a variety of reasons that we explore, also raise unanswered questions. In this review we summarize what is known about the rhythm generating circuits associated with breathing that arise from the different rhombomeric segments in each of the different vertebrate classes. Assuming oscillating circuits form in every pair of rhombomeres in every vertebrate during development, we trace what appears to be the evolutionary fate of each and highlight the questions that remain to be answered to properly understand the evolutionary transitions in vertebrate central respiratory rhythm generation.

O65: C-MET PROTEIN AS A COLORECTAL CANCER BIOMARKER FOR FLUORESCENCE IMAGE-GUIDED SURGERY

Introduction

The c-Met transmembrane protein is vital for cell differentiation and migration and is overexpressed in many gastrointestinal cancers. This study aimed to investigate a novel c-Met targeted peptide coupled to a fluorophore (EMI-137, Edinburgh Molecular Imaging Ltd.) for use in fluorescence image-guided colorectal cancer (CRC) surgery.

Method

A high c-Met expressing cell-line, HT29, was identified with temporary RNA suppression and used to develop a mouse xenograph CRC model. Tumours were allowed to grow to 10mm. EMI-137 was injected into the tail vein and biodistribution analysed using the IVIS system.

Nine patients undergoing elective surgery for colon cancer received a single IV dose EMI-137 1-3 hours before surgery. Tumour and LN fluorescence was assessed with a prototype Karl Storz laparoscope. Intraoperative fluorescence was correlated with radiological and pathological TNM stage and tissue c-Met expression using immunohistochemistry.

Result

The HT29 xenograph CRC model demonstrated selective EMI-137 uptake and fluorescence 1- 6 hours post administration. Nine participants aged 67-77 years received EMI-137 106 minutes (S.D±17) before surgery. Marked background fluorescence was observed in all patients. 4/9 (44%) patients showed mild increase in tumour fluorescence over background. 5/9 patients had histological LN disease, but no fluorescent nodes were detected intraoperatively. There was no correlation with T-stage. At histopathological assessment 8/9 participants showed moderate or high tumour c-Met expression. 8/8 malignant LNs demonstrated high c-Met expression.

Conclusion

EMI-137 is specific for human c-Met in 2D and xenograph CRC models. EMI-137 is safe for human use but its utility is limited by insufficient tumour-to-background ratios.

Take-home message

This first-in-man study of a novel fluorescent peptide targeted to the c-Met receptor, found EMI-137 lacked the sensitivity and specificity to accurately map the tumour margins and lymph node burden in laparoscopic colonic cancer resection surgery.

Clinical utility of liver biopsies in dogs undergoing splenectomy

OBJECTIVE

To determine the prevalence of neoplasia detected on liver biopsy obtained at the time of splenectomy in dogs with splenic masses.

MATERIALS AND METHODS

Retrospective study of medical records of dogs with splenic masses from which liver biopsies were taken following splenectomy.

RESULTS

Malignant splenic neoplasia was detected in 50 of 113 (44.2%) of the dogs undergoing splenectomy. Neoplastic liver disease was detected on biopsy from 1 of 40 (2.5%) dogs with a grossly normal liver and from 20 of 69 (28.9%) dogs with a grossly abnormal liver. Dogs with a grossly abnormal liver had a ~ 16 times (95% CI: 2.5-170) higher chance of being diagnosed with liver neoplasia on biopsy. Haemoabdomen was also associated with an increased likelihood of liver neoplasia on biopsy at the time of splenectomy.

CLINICAL SIGNIFICANCE

A liver biopsy taken from grossly normal liver is a low-yield diagnostic test but liver biopsy is recommended following splenectomy if the liver appears abnormal at surgery.

Arginine Metabolism in Supragingival Oral Biofilms as a Potential Predictor of Caries Risk

INTRODUCTION

Ammonia production via the arginine deiminase system (ADS) of oral bacteria can function to reduce the cariogenicity of oral biofilms by neutralizing glycolytic acids that cause tooth demineralization.

OBJECTIVES

This cohort study investigated the relationship between ADS activity and bacterial profile changes of supragingival biofilms with caries experience among children over time.

METHODS

A total of 79 children aged 2 to 7 y at baseline were assessed every 6 mo for a period of 18 mo. Children were grouped as caries free (CF), caries active with enamel lesions (CAE), or caries active with dentin lesions (CA). Supragingival plaque samples were collected from caries-free surfaces (PF) and from enamel (PE) and dentin (PD) lesions. Plaque ADS activity was measured by monitoring citrulline production from arginine and compared with ribosomal 16S rRNA-derived taxonomic profiles for the same samples.

RESULTS

At baseline, 37% of the children were CF, 34% CAE, and 29% CA. At 18 mo, 26% were CF, 41% CAE, 23% CA, and 10% were caries experienced (new restorations but no caries activity). Throughout the study period, ADS activity was significantly higher in the CF group than the CA group (P < 0.0001), and ADS activity in the PF samples was significantly higher than in the PE and PD samples (P < 0.0001). Distance-based redundancy analysis showed that the bacterial communities could be differentiated when plaque samples are grouped into levels of high and low ADS activity.

CONCLUSIONS

There is a positive correlation between caries activity and low arginolytic capacity of the supragingival oral biofilms of children and tooth surfaces over time. Measurements of arginine metabolism via ADS may be useful to differentiate the caries risk of individuals and tooth surfaces.

KNOWLEDGE TRANSFER STATEMENT

Findings from this study support the development of new strategies for caries risk assessment and prevention based on modulation of the virulence of the oral microbiome through arginine metabolism in supragingival biofilms.

Abstract GS3-02: PALLET: A neoadjuvant study to compare the clinical and antiproliferative effects of letrozole with and without palbociclib

Background: CDK4/6 inhibitors, such as palbociclib, are used to treat ER+ metastatic breast cancer in combination with endocrine therapy with trials ongoing in patients with primary disease. No biomarkers exist to identify those who do/do not benefit from added CDK4/6 inhibition. PALLET is an investigator-initiated/led phase II randomized trial collaboration between UK and NSABP investigators evaluating the biological and clinical effects of palbociclib with letrozole combination as neoadjuvant therapy.

Methods: Postmenopausal women with ER+ primary breast cancer and tumors &gt;2.0cm (ultrasound) were randomized to one of 4 treatment groups (3:2:2:2 ratio): Group A: letrozole (2.5mg/d) for 14 weeks; Group B: letrozole for 2 weeks followed by letrozole + palbociclib to 14 weeks; Group C: palbociclib for 2 weeks followed by letrozole + palbociclib to 14 weeks; Group D: letrozole + palbociclib for 14 weeks. Palbociclib was given 125mg/d PO on a 21 days on, 7 days off schedule. Post-14 week treatment was at the discretion of the treating clinician including letrozole until surgery. Core-cut biopsies were taken at baseline, 2 weeks and 14 weeks. Co-primary endpoints for letrozole alone vs palbociclib groups (Group A vs Groups B+C+D) were: (i) change in Ki67 (IHC) between baseline and 14 weeks (log-fold change, Mann-Whitney test); (ii) clinical response (ultrasound) after 14 weeks (4 group, ordinal, Mann-Whitney test). Complete cell-cycle arrest (CCCA) (Ki67≤2.7%) was analyzed using a logistic regression model adjusting for recruitment region. Pre-specified exploratory biomarkers included c-PARP (apoptosis).

Results: 307 patients were recruited between 27 Feb 2015 and 08 Mar 2018; 103 were randomized to letrozole alone and 204 to letrozole + palbociclib. 279 (90.9%) patients were evaluable for 14 week clinical response. Clinical response was not significantly different between letrozole vs letrozole + palbociclib groups [(p=0.20; CR+PR 49.5% (46/93) vs 54.3% (101/186) and PD 5.4% (5/93) vs 3.2% (6/186)] nor was the small proportion of patients with pathological CR (1/87, 1.1% vs 6/180, 3.3%; p=0.43). 190 (61.9%) patients were evaluable for 14 week change in Ki67. The median log-fold change in Ki67 was greater with letrozole + palbociclib vs letrozole alone (-4.1 vs -2.2; p&lt;0.001) corresponding to a geometric mean change of -97.4% vs -88.5%. Similarly, a greater proportion of patients who received letrozole + palbociclib achieved CCCA (90% vs 59%, p&lt;0.001). 146 (47.6%) patients were evaluable for c-PARP and the log-fold change (suppression) was greater with letrozole + palbociclib vs letrozole alone (-0.80 vs -0.42; p=0.003) corresponding to a geometric mean change of -56.8% vs -31.4%. Other biomarkers of response / resistance are being evaluated. A higher proportion of patients had a grade ≥3 toxicity on letrozole + palbociclib than letrozole alone (49.8% vs 17.0%; p&lt;0.001) mainly due to asymptomatic neutropenia.

Conclusion: Adding palbociclib to letrozole markedly enhanced the suppression of malignant cell proliferation as assessed by Ki67 but did not substantially increase the clinical response of primary ER+ breast cancer over a 14-week period. Concurrent reductions in cell death may have reduced the speed of tumor shrinkage.

Citation Format: Dowsett M, Jacobs S, Johnston S, Bliss J, Wheatley D, Holcombe C, Stein R, McIntosh S, Barry P, Dolling D, Snowdon C, Perry S, Batten L, Dodson A, Martins V, Modi A, Cornman C, Puhalla S, Wolmark N, Julian T, Pogue-Geile K, Robidoux A, Provencher L, Boileau JF, Shalaby I, Thirlwell M, Fisher K, Huang Bartlett C, Koehler M, Osborne K, Rimawi M. PALLET: A neoadjuvant study to compare the clinical and antiproliferative effects of letrozole with and without palbociclib [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr GS3-02.

Factors influencing medical student self-competence to provide weight management services

This study aimed to identify factors associated with high obesity care self-competence among US medical students. The authors performed a cross-sectional analysis of 2014 survey data on fourth year medical students collected online as part of the Medical Student Cognitive Habits and Growth Evaluation Study (CHANGES). Independent variables included quality and quantity of interaction with patients and peers with obesity; hours of communication and partnership skills training; negative remarks against patients with obesity by supervising physicians, and witnessed discrimination against patients with obesity. The dependent variable was self-competence in providing obesity care. Of 5823 students invited to participate, 3689 (63%) responded and were included in our analyses. Most students were white (65%), half were women and 42% had high self-competence in caring for patients with obesity. Factors associated with high self-competence included increased interaction with peers with obesity (39% vs. 49%, P < 0.001) and increased partnership skills training (32% vs. 61%, P < 0.001). Increased partnership skills training and quantity of interactions with peers with obesity were associated with high student self-competence in providing obesity-related care to patients. Medical schools might consider increasing partnership skills training to improve students' preparedness and skill in performing obesity-related care.

Marine Carbonates in the Mantle Source of Oceanic Basalts: Pb Isotopic Constraints

For almost fifty years, geochemists have been interpreting the clues from Pb isotopic ratios concerning mantle composition and evolution separately. The Pb isotopes of ocean island basalts (OIB) indicate that their mantle source is heterogeneous, most likely due to the presence of end-components derived from recycled crust and sediment. Some OIB have unusually high 206Pb/204Pb coming from one of the end-components with a long time-integrated high 238U/204Pb or μ (HIMU). Most OIB and many mid-ocean ridge basalts (MORB) also have high 206Pb/204Pb, indicating a HIMU-like source. Moreover, measured 232Th/238U (κ) for most MORB are lower than those deduced from their 208Pb/204Pb and 206Pb/204Pb. Such high μ and low κ features of oceanic basalts are inconsistent with the known geochemical behavior of U, Pb and Th and temporal evolution of the mantle; these have been respectively termed the 1st and 2nd Pb paradox. Here we show that subducted marine carbonates can be a source for HIMU and a solution to the Pb paradoxes. The results are consistent with the predictions of the marine carbonate recycling hypothesis that posits the Pb isotopes of oceanic basalts indicate a common origin and/or magma generation process.

Young patients and gastrointestinal (GI) tract malignancies - are we addressing the unmet needs?

Background

Recent epidemiological studies indicate the rate of gastrointestinal (GI) malignancies among younger patients is increasing, mainly due to colorectal cancer. There is a paucity of data regarding the magnitude of treatment-related symptoms, psychosocial issues and potential unmet needs in this population. We aimed to characterize the needs of this population to evaluate whether unmet needs could be targeted by potential intervention.

Methods

Female and male patients diagnosed with cancer of the gastrointestinal tract <40y retrospectively completed a questionnaire to evaluate symptoms, daily function and unmet needs at pre-treatment, during and post-treatment. Comparisons were made by gender, disease stage and treatment modality. Multiple linear regression models evaluated effects of demographics, symptoms and needs on multiple domains of health-related-quality-of-life (using Short-Form Health Survey-12 and CARES).

Results

Fifty patients were enrolled (52 % female) to a pilot study. Median age at diagnosis was 35.5y (range, 21-40y). The symptoms that significantly increased from baseline to during and post-treatment were: diarrhea (37 %), sleeping disorder (32 %) and sexual dysfunction (40 %). Patients also reported significant deterioration in occupational activities and coping with children compared with baseline. Female patients reported significant unmet need for nutritional counseling and psychosocial support compared to male patients (p < 0.05). Patients treated with multimodality-treatment presented higher rates of unmet needs (p = 0.03).

Conclusions

Young patients with GI cancers represent a group with unique characteristics and needs compared with published evidence on other young-onset malignancies. The distinctive symptoms and areas of treatment-related functional impairments indicate there are unmet needs, especially in the area of psychosocial support and nutritional counseling.

Oral arginine metabolism may decrease the risk for dental caries in children

Arginine metabolism by oral bacteria via the arginine deiminase system (ADS) increases the local pH, which can neutralize the effects of acidification from sugar metabolism and reduce the cariogenicity of oral biofilms. To explore the relationship between oral arginine metabolism and dental caries experience in children, we measured ADS activity in oral samples from 100 children and correlated it with their caries status and type of dentition. Supragingival dental plaque was collected from tooth surfaces that were caries-lesion-free (PF) and from dentinal (PD) and enamel (PE) caries lesions. Regardless of children's caries status or type of dentition, PF (378.6) had significantly higher ADS activity compared with PD (208.4; p < .001) and PE (194.8; p = .005). There was no significant difference in the salivary arginolytic activity among children with different caries status. Mixed-model analysis showed that plaque caries status is significantly associated with ADS activity despite children's age, caries status, and dentition (p < .001), with healthy plaque predicting higher ADS activity compared with diseased plaque. Plaque arginine metabolism varies greatly among children and tooth sites, which may affect their susceptibility to caries.

Chronic fatigue syndrome in the UK armed forces

Chronic Fatigue Syndrome (CFS) is a debilitating condition that can have a significant impact on the lives of patients and those who care for them. In the UK Armed Forces this condition can also have a marked impact on a patient's career and their ability to function in the deployed environment. In this article the recognition and management of CFS will be discussed, as well as the occupational considerations within the UK Armed Forces.

The impact of mucosal infections on acquisition and progression of tuberculosis

More than one-third of the world's population, or over 2 billion people, are infected with Mycobacterium tuberculosis, the causative pathogen of tuberculosis in humans. Why only 10% of those infected develop active disease while the remainder harbor latent infection remains one of the greatest scientific and public health mysteries. Bacterial persistence is characterized by a dynamic state of immunological tolerance between pathogen and host. The critical role of CD4(+) T cells in defense against intracellular pathogens became evident during epidemiological studies of HIV-1 infection, which showed a clear inverse relationship between CD4(+) T-cell count in peripheral blood and increased risk of infection with M. tuberculosis, pneumocystis and Toxoplasma gondii. There is also growing evidence of a common mucosal immune system, whereby immune cells activated at one mucosal site may disseminate to remote effector sites. In this commentary, we review emerging evidence from human studies that the outcome of M. tuberculosis infection is influenced by concurrent mucosal infections, using Helicobacter pylori and geohelminths as examples. Understanding how the complexity of microbial exposures influences host immunity may have important implications for vaccine development and therapeutic interventions.

The systemic inflammatory response following femoral canal reaming using the reamer-irrigator-aspirator (RIA) device

We evaluated the peripheral release of inflammatory mediators after femoral fracture and subsequent intramedullary reaming using the RIA reamers. IL-6 was elevated after trauma, and reaming with RIA induced a measurable second hit response. However, despite a higher ISS, the levels of IL-6 in the RIA group were similar to the levels measured in a group of patients where reaming of the femoral canal was performed using conventional reamers. There was one death related to fat embolism syndrome in the conventional reamers group. However, the overall incidence of complications was low and similar between the 2 groups of studied patients. In polytrauma patients, large scale studies are desirable to evaluate further the immuno-inflammatory response using the RIA reamers prior to the instrumentation of the femoral canal.

Psychological distress among male patients and male spouses: what do oncologists need to know?

BACKGROUND

The aim of the current study was to strengthen the knowledge of oncologists concerning psychological distress and social support among married and unmarried male cancer patients and healthy male spouses of female cancer patients.

PATIENTS AND METHODS

Three groups of men were recruited from three major cancer centers in Israel: 185 married colon and rectal cancer patients, 54 single (unmarried) colon and rectal cancer patients, and 153 male spouses of female cancer patients. Participants were evaluated on four standardized instruments measuring psychological distress, coping, and social support.

RESULTS

About 42.6% of the participants reported on a clinical level of psychological distress, with the highest rates (61.1%) among the single (unmarried) patients. Distress was negatively correlated to Karnofsky score and coping variables among all study groups. Distress was significantly and negatively correlated to social support variables among the spouses and married patients but not among the single patient groups.

CONCLUSIONS

Social support received by male cancer patients from friends and family may be mediated by spouse support. As a result, single male patients are at higher risk for psychological distress. Male spouses were also found to have high rates of distress. These two groups need special attention by oncologists.

Temozolomide (TMZ) and bevacizumab (BV) as initial treatment for unresectable or multifocal glioblastoma multiforme (GBM)

e13025

Background: GBMs are vascular tumors and inherently resistant to therapy. The prognosis for patients is poor with a median survival of 9–15 months. Patients with unresectable or multifocal GBMs have an even poorer prognosis, with a median survival of 6–8 months. Given the angiogenic phenotype of GBM, we conducted a phase II trial of upfront BV and 5-day TMZ in newly diagnosed unresectable or multifocal GBMs. Methods: Patients had histologically documented newly diagnosed GBMs that were unresectable or multifocal. Patients received up to 4 cycles of temozolomide at 200 mg/m2/d days 1–5 and BV at 10 mg/kg on days 1 and 14 in a 28 day cycle. An MRI was performed after every cycle and patients continued on therapy as long as there was no tumor progression, grade 4 non-hematologic toxicity or recurrent grade 4 hematologic toxicity after a dose reduction to 150 mg/m2/d. The primary endpoint was tumor response using the modified MacDonald criteria plus FLAIR and T2 sequences to evaluate non-enhancing tumor. Results were evaluated by two independent reviewers. Results: 41 patients were enrolled between October 2007 and September 2008 and 31 patients were analyzed after completion of cycle 2. As the best response, there were 8 (25.8%) partial responses, 19 (61.3 %) patients with stable disease, and 4(12.9 %) had disease progression. 19 of the 41 patients enrolled completed four cycles without tumor progression. The regimen was tolerable, with 3 grade 4 hematologic toxicities including neutropenia and thrombocytopenia. There were 2 grade 4 non-hematologic toxicities, including pulmonary embolism. There were two CNS hemorrhages. The median PFS was 3.6 months (2.9 months, 4.4 months) and the median OS was 4.5 months (3.7 months, 5.3 months). Conclusions: Upfront temozolomide and bevacizumab was well tolerated, but synergistic chemotherapy or growth factor inhibitors need to be added to produce meaningful clinical benefit, particularly for unresectable or multifocal GBM.

No significant financial relationships to disclose.

Cognitive development in macaques: Attentional set-shifting in juvenile and adult rhesus monkeys

In humans and nonhuman primates, the structure and function of frontal cortical regions of the brain are not completely developed until early adulthood. How this cortical development affects cognitive function continues to be elucidated. To that end, this experiment tested the ability of juvenile and adult rhesus monkeys to perform a cognitive task that is dependent upon intact frontal cortical function for optimal performance. Twenty-four juvenile (mean age 2.3 years) and 16 adult (mean age 10.3 years) rhesus monkeys were tested on the Cambridge Neuropsychological Test Automated Battery intradimensional/extradimensional set-shifting (ID/ED) task. Performance on the ID/ED task has been shown to be dependent upon frontal cortical function in both humans and nonhuman primates. Compared with adults, juveniles were impaired on the reversal of simple discrimination, intradimensional shift, reversal of intradimensional shift, and the extradimensional shift stages of the task. These results indicate juveniles committed more perseverative errors and more errors on the set-formation and set-shifting components of the ID/ED task. The developmental stage of the juvenile monkeys corresponds to roughly 5 to 6-year-old children, and these results are consistent with performance of human children and adults on similar ID/ED tests and on several other tests of attentional set-shifting or attentional flexibility. Furthermore, these results are consistent with the ongoing development of frontal cortical structures relating to ongoing cognitive development in nonhuman primates.

Conservation of Pitx1 expression during amphibian limb morphogenesis

In contrast to the pattern of limb emergence in mammals, chicks, and the newt N. viridescens, embryos such as Xenopus laevis and Eleutherodactylus coqui initiate pelvic limb buds before they develop pectoral ones. We studied the expression of Pitx1 in X. laevis and E. coqui to determine if this paired-like homeodomain transcription factor directs differentiation specifically of the hindlimb, or if it directs the second pair of limbs to form, namely the forelimbs. We also undertook to determine if embryonic expression patterns were recapitulated during the regeneration of an amputated limb bud. Pitx1 is expressed in hindlimbs in both X. laevis and E. coqui, and expression is similar in both developing and regenerating limb buds. Expression in hindlimbs is restricted to regions of proliferating mesenchyme.

Relationship between biological and self-reported measures of stress among informal caregivers of patients with prostate cancer

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Background: Informal caregivers of prostate cancer patients often experience chronic psychological stress that may adversely impact their physical and mental health, and their ability to care for their families and the patient. This study aims to determine the association between perceived and biological stress among informal caregivers of prostate cancer patients. Methods: A total of 24 informal caregivers of prostate cancer patients were recruited from both the Jesse Brown VA Center (Lakeside and Westside, Chicago) and the Robert H. Lurie Comprehensive Cancer Center at Northwestern University. Caregivers completed self-reported measures of stress, somatization, life events, burden, health status (SF-36) and mental health. Capillary blood spot samples from caregivers were used to examine two measures of biological stress, Epstein-Barr virus antibody titer and C-reactive protein. Results: Informal caregivers had a mean age of 63 years and were mostly female and spouses of patients with prostate cancer. Many had preexisting co-morbidities, including 45.8% with hypertension, 45.8% with arthritis, and 33.3% with diabetes. Nearly 30% had been hospitalized in the last 12 months. 33.3% of caregivers experienced at least one major life event in the last year and 62.5% had symptoms of somatization illness. Caregivers with symptoms of somatization illness had higher mean Epstein-Barr antibody titers as compared with those without symptoms (Mean EBV antibody titer: 198.3 versus 141.8, respectively (p < 0.05)). Caregiver-reported measures were not correlated with C-reactive protein levels. Caregivers with higher levels of strain perceived more stress in their lives (p < 0.05), but showed relatively high self-esteem (mean = 30.6, SD = 2.8, on a 7–35 scale). Conclusions: These preliminary findings suggest that informal caregivers who report symptoms of somatization illness exhibit signs of relative suppression of the cell-mediated immune processes as a result of the reactivation of the Epstein-Barr virus. Final analyses will be conducted that control for potential confounders and will further elucidate if caregiver stress is associated with suppression of the immune system.

No significant financial relationships to disclose.

Malaria prevention practices in Mopti region, Mali

OBJECTIVES

To assess insecticide-treated nets (ITNs) use, other malaria prevention measures, knowledge of malaria and diffusion of information about ITNs by the National Malaria Control Programme (NMCP) in Mali.

DESIGN

A descriptive cross-sectional study.

SETTING

Four villages in Mopti region, Mali that had participated in the Mopti Regional Malaria Control Program (MRMCP) ITN Education Programme five years prior.

PARTICIPANTS

Three hundred thirty nine randomly-selected households. Within each household, mothers of children one to nine years of age were interviewed regarding knowledge of malaria and prevention practices.

RESULTS

Overall, 11% of households used ITNs, with 97% of these in two villages. Ninety eight percent of households used bednets, 22% used insecticide sprays and 39% used mosquito coils. Significant predictors of ITNs use were: head of household literacy, larger family size, Bambara ethnicity, hearing about the NMCP and hearing about ITNs from health agents. Reasons why ITNs were not used included not knowing anything about ITNs, cost and not having net impregnation services readily available in the village. Levels of knowledge concerning malaria disease, transmission and prevention varied amongst the four villages. ITN households had significantly higher levels of knowledge about malaria and its prevention.

CONCLUSION

Five years after the implementation of the MRMCP, ITNs use was low and diffusion of malaria prevention information was unequal among villages. Future efforts in improving the programme must recognise these differences in knowledge and ITNs utilisation and make village-specific changes that are acceptable for each village.

Integration of microscopy and serodiagnostic tests to screen for active tuberculosis

SETTING

University of California San Diego Medical Center, USA.

OBJECTIVE

To create a simple screening strategy for tuberculosis (TB) that includes antibody detection assays to improve the accuracy of microscopic examination of sputum for acid-fast bacilli (AFB smear).

METHODS

Serum samples were obtained from 190 patients suspected of having active TB. TB diagnosis was established by Mycobacterium tuberculosis culture. HIV status was determined by commercial serologic tests. IgG antibody levels were measured by ELISA using purified M. tuberculosis antigens. Data from 130 randomly selected patients were used to develop a screening strategy; data from the remaining 60 patients were used for validation.

RESULTS

AFB smear had 70% sensitivity and 88% specificity. In algorithms integrating single or multi-antigen ELISA with AFB smear and HIV results, the sensitivity improved over each test alone. The algorithm that included a four-antigen ELISA (38 kDa antigen, lipoarabinomannan, MPT-64 and glutamine synthase) had a sensitivity of 93% and a specificity of 76%. Compared to AFB smear, the sensitivity of the algorithm was significantly higher, while the specificity was not statistically different.

CONCLUSION

This study demonstrates that a screening strategy can be created by integrating multi-antigen ELISA with AFB smear and HIV testing.

QuantiFERON-TB predicts tuberculin skin test boosting in U.S. foreign-born

SETTING

Santa Clara County, Northern California.

OBJECTIVE

To characterize agreement of tuberculin skin test (TST) and QuantiFERON-TB (QFT) with repeated testing.

DESIGN

Fifty-two subjects participating in an ongoing prospective study of infectious disease transmission were tested by TST and QFT at two home visits 3 months apart. Boosting was defined as reclassification of TST from negative to positive. Agreement and reproducibility of TST and QFT were assessed using kappa and McNemar statistics.

RESULTS

Of 48 individuals completing all tests, 75% were foreign-born (92% Latin America) and 58% were BCG-vaccinated. Initial TST and QFT were positive in 13 (27%) and 21 (44%), respectively, with an overall agreement of 67% (K = 0.29). Ten (29%) of 35 initial TST-negative reactions boosted, nine of whom were BCG-vaccinated subjects. Boosting occurred in eight (67%) of 12 subjects who were initially QFT-positive/TST-negative. Compared to the second TST, initial QFT had a relative post-test probability of 76% (95% CI 0.58-0.95); boosting accounted for 8/16 (50%) of initial testing discordances.

CONCLUSION

Positive QFT in the setting of negative TST frequently anticipates a TST boost. This finding helps explain discordance between the two tests and may provide an alternative to serial TST testing.

The facilitating factors and barriers influencing change in dental practice in a sample of English general dental practitioners

AIM

The objective of this study was to investigate the barriers and facilitators to change in dental practices among a sample of general dental practitioners (GDPs) from three regions of England.

METHOD

In-depth face-to-face interviews with 60 GDPs were undertaken. The sample was selected from a group of 317 GDPs who had completed a questionnaire in the first phase of this study. The participants were selected to reflect diversity regarding the number and extent of self-reported changes reported in the questionnaire, and personal and practice characteristics. Of the 92 attempted contacts, 60 (65%) of the interviews were successfully completed. The interview schedule formed the basis of the interview. All the interviews and notes were transferred on to NUD*IST QSR version 4, a qualitative analysis package.

RESULTS

No single factor was identified as being more important than another in facilitating change. The main facilitators for change were: financial factors, regular patient attendance, particularly a core patient group, staff loyalty, having regular staff meetings and open communication and having access to peer support. The main barriers to change were the reverse of the facilitators plus not having a financial stakehold in the practice.

CONCLUSIONS

A range of factors were identified as influencing change in general dental practice. These include GDPs' attitudes and experience of change, patient factors, organisational issues, contact with peers and access to appropriate training courses.

The prevalence and nature of recent self-reported changes in general dental practice in a sample of English general dental practitioners

OBJECTIVE

To determine the extent and types of change in seven domains of dental practice in a sample of English general dental practitioners (GDPs).

METHODS

A postal questionnaire was sent to 561 GDPs on the dental lists of three health authorities in diverse regions of England. Information collected included demographic details on personal and practice characteristics, self-rating of amount of change in the seven domains of practice and factors influencing change.

RESULTS

The response rate was 60%. Fifty-six per cent of the sample were under 40 years old. Over a third of respondents reported "changing a lot or completely" certain clinical activities, practice management arrangements and practice amenities. The highest self-reported level of change was in clinical activities. Of the GDPs who reported changing their clinical activities, 56% reported an increase in preventive care, followed by crown and bridge (44%), periodontics (44%) and endodontics (43%). Practice management rated second in the mean rank scores for self-reported change. The main changes reported were the introduction of computer systems and employment of practice managers. A sizeable percentage (66%) reported increasing the amount of information they provided to patients and the time spent discussing care. Quality assurance activities were the area of practice least likely to have changed over a 5-year period. Over half the sample reported not being involved in any quality assurance activities in the previous 5 years. Those respondents who were younger, had a postgraduate qualification and earned more than 20% of their income from private practice reported higher levels of change.

CONCLUSIONS

General dental practitioners' work patterns are dynamic and appear to be responding to changing needs and demands on their service. The main changes were in the types of clinical procedures being carried out. The low prevalence of changes reported in auditing and peer review activities needs to be investigated further.

Reliability and validity of the SF-36 in HIV-infected homeless and marginally housed individuals

OBJECTIVE

To assess the reliability and validity of the Short-Form 36 (SF-36) health survey as a health status indicator among HIV-infected homeless and marginally housed (HMH) individuals.

METHODS

Between July 1996 and May 2000, a sample of HMH individuals completed interviews that included the SF-36. Responses to the SF-36 were analyzed for missing data, range, internal consistency, and construct validity.

RESULTS

Among 330 individuals interviewed, 83% were male, 43% were African-American, and the median age was 39 years. All internal consistency reliability coefficients exceeded 0.70, all item-scale correlations exceeded 0.40, all items were more strongly correlated with their hypothesized scale than any other scale, and all reliability coefficients exceeded inter-scale correlations for the same scale. Three of four physical health scales were significantly associated with CD4 cell count and HIV viral load. All scales were significantly associated with depression.

DISCUSSION

We found that scales were internally consistent, items correlated to an acceptable degree with their hypothesized scales, items were distinct from other scales, physical scales were associated with CD4 cell count and viral load, and all scales were associated with depression. These analyses provide evidence for the reliability and validity of the SF-36 as a measure of health status in HIV-positive HMH individuals.

Technology Assessment at the National Level in the US

At one time, the US Government's health technology assessment programs [i,e., the evaluation of drugs, devices, and procedures used in health care for their safety, effectiveness, cost, and social implications) were models for both the public and private sector agencies and for the rest of the world. This time is no more. Three years has passed since the most prominent technology assessment program in this country, if not the world, was terminated by the US Congress.

The strong ion gap does not have prognostic value in critically ill patients in a mixed medical/surgical adult ICU

OBJECTIVE

To examine whether the strong ion gap (SIG) or standard base excess corrected for abnormalities of serum chloride and albumin (BE(UA)) can predict outcome and to compare the prognostic abilities of these variables with standard base excess (SBE), anion gap (AG), pH, and lactate, the more traditional markers of acid-base disturbance.

DESIGN

Prospective, observational study.

SETTING

University teaching hospital, general adult ICU.

PATIENTS

One hundred consecutive patients on admission to the ICU.

MEASUREMENTS AND RESULTS

The anion gap (AG) was calculated and corrected for abnormal serum albumin (AG(corrected)). Serum lactate was measured and SBE, BE(UA), SIG, and APACHE II scores calculated for each patient. 28-day survival was recorded. There was a significant difference between the mean APACHE II (P < 0.001), SBE (P < 0.001), lactate (P = 0.008), AG (P = 0.007), pH (P < 0.001), and BE(UA) (P = 0.009) of survivors and non-survivors. There was no significant difference between the mean SIG (P = 0.088), SIDeff (P = 0.025), and SID app (P = 0.254) between survivors and non-survivors. The pH and SBE demonstrated the best ability of the acid-base variables to predict outcome (AUROC curves 0.72 and 0.71, respectively). Neither of these were as good as the APACHE II score (AUROC 0.76)

CONCLUSION

Traditional indices of SBE, BE(UA,) lactate, pH, AG, and APACHE II all discriminated well between survivors and non-survivors. In this group of patients the SIG, SIDeff, and SIGapp appear to offer no advantage in prediction of outcome and their use as prognostic markers can therefore not be advocated.

Prevalence of faecal incontinence in adults aged 40 years or more living in the community

BACKGROUND

Prevalence studies of faecal incontinence in the general population are rare and the impact of faecal incontinence on quality of life has not been previously addressed.

AIMS

To establish the prevalence of faecal incontinence in adults in terms of frequency of leakage, degree of soiling, and level of impact on quality of life.

METHODS

In a cross sectional postal survey, 15 904 adults aged 40 years or more (excluding residents of nursing and residential homes) were selected randomly by household from the Leicestershire Health Authority patient register. Participants were asked to complete a confidential health questionnaire. Major faecal incontinence was defined as soiling of underwear or worse with a frequency of several times a month or more. Respondents were also asked if bowel symptoms had an impact on their quality of life.

RESULTS

From a total sample of 10 116 respondents, 1.4% reported major faecal incontinence and 0.7% major faecal incontinence with bowel symptoms that had an impact on quality of life. Major faecal incontinence was significantly associated with a lot of impact on quality of life (odds ratio 12.4, 95% confidence interval 7.5-20.6). Incontinence was more prevalent and more severe in older people but there was no significant difference between men and women.

CONCLUSIONS

This study has confirmed that faecal incontinence is a fairly common symptom, particularly in older people. Faecal incontinence in men has received little attention in the past and the results from this study indicate that it is as much of a problem in men as it is in women while the level of unmet need in this group is high. Estimates of need for health care for this symptom should be multidimensional and assess both the severity of symptoms and the impact it has on quality of life.

Discrimination functions: can they be used to classify singing voices?

Researchers long have searched for invariant acoustic features that can be used to identify singing voice categories or even individual singers. Few researchers have examined how listeners perceive singing voice categories or individual voices. Timbre, the most studied perceptual dimension of the singing voice, is generally believed to vary systematically between singing voice categories but is often assumed to be invariant with an individual singer. To test this assumption, 2 mezzo-sopranos and 2 sopranos were recorded singing the vowel /a/ on the pitches A3, C4, G4, B4, F5, and A5. Trials of three stimuli were constructed. Two of the three stimuli in each trial were produced by the same singer at two different pitches (X1 and X2), while the third stimulus was produced by a different singer (Y). Three X1X2 conditions were created: (1) G4, B4; (2) C4, F5; and (3) A3, A5. For each singer and each condition, Y was varied across the three remaining singers and across all six pitches. Experienced and inexperienced listeners were asked to identify which stimulus was produced by the "odd" person. The ability to correctly choose the odd person varied greatly depending on pitch factors, suggesting that the traditional concept of an invariant timbre associated with a singer is inaccurate and that vocal timbre must be conceptualized in terms of transformations in perceived quality that occur across an individual singer's range and/or registers.