Checkpoint molecule expression by B and T cell lymphomas in dogs.

Immunotherapies targeting checkpoint molecule programmed cell death 1 (PD-1) protein were shown to be effective for treatment of non-Hodgkin lymphoma in people, but little is known about the expression of PD-1 or its ligand PD-L1 by canine lymphoma. Therefore, flow cytometry was used to analyse expression of PD-1 and PD-L1 in canine lymphoma, using fine-needle aspirates of lymph nodes from 34 dogs with B cell lymphoma (BCL), 6 dogs with T cell lymphoma (TCL) and 11 dogs that had relapsed. Furthermore, fine-needle aspirates were obtained from 17 healthy dogs for comparison. Lastly, the impact of chemotherapy resistance on expression of PD-1 and PD-L1 was assessed in vitro. These studies revealed increased expression of PD-L1 by malignant B cells compared to normal B cells. In the case of TCL, tumour cells and normal T cells both showed low to negative expression of PD-1 and PD-L1. In addition, tumour infiltrating lymphocytes from both BCL and TCL had increased expression of both PD-1 and PD-L1 expression compared to B and T cells from lymph nodes of healthy animals. In vitro, chemotherapy-resistant BCL and TCL cell lines exhibited increases in both PD-1 and PD-L1 expression, compared to non-chemotherapy selected tumour cells. These findings indicate that canine lymphomas exhibit upregulated checkpoint molecule expression, though the impact of checkpoint molecule expression on tumour biological behaviour remains unclear.

Immune regulation of canine tumour and macrophage PD-L1 expression.

Expression of programmed cell death receptor ligand 1 (PD-L1) on tumor cells has been associated with immune escape in human and murine cancers, but little is known regarding the immune regulation of PD-L1 expression by tumor cells and tumor-infiltrating macrophages in dogs. Therefore, 14 canine tumor cell lines, as well as primary cultures of canine monocytes and macrophages, were evaluated for constitutive PD-L1 expression and for responsiveness to immune stimuli. We found that PD-L1 was expressed constitutively on all canine tumor cell lines evaluated, although the levels of basal expression were very variable. Significant upregulation of PD-L1 expression by all tumor cell lines was observed following IFN-γ exposure and by exposure to a TLR3 ligand. Canine monocytes and monocyte-derived macrophages did not express PD-L1 constitutively, but did significantly upregulate expression following treatment with IFN-γ. These findings suggest that most canine tumors express PD-L1 constitutively and that both innate and adaptive immune stimuli can further upregulate PD-L1 expression. Therefore the upregulation of PD-L1 expression by tumor cells and by tumor-infiltrating macrophages in response to cytokines such as IFN-γ may represent an important mechanism of tumor-mediated T-cell suppression in dogs as well as in humans.

Monitoring agricultural rodenticide use and secondary exposure of raptors in Scotland.

Despite the documented risk of secondary poisoning to non-target species by anticoagulant rodenticides there is no statutory post-approval monitoring of their use in the UK. This paper presents results from two Scottish monitoring schemes for the period 2000-2010; recording rodenticide use on arable farms and the presence of residues in raptor carcasses. More than three quarters of arable farms used anticoagulant rodenticides; predominately the second generation compounds difenacoum and bromadiolone. There was widespread exposure to anticoagulant rodenticides in liver tissues of the raptor species tested and the residues encountered generally reflected agricultural use patterns. As found in other studies, Red Kites (Milvus milvus) appeared to be particularly vulnerable to rodenticide exposure, 70 % of those sampled (n = 114) contained residues and 10 % died as a result of rodenticide ingestion. More unexpectedly, sparrowhawks (Accipiter nisus), which prey almost exclusively on birds, had similar exposure rates to species which prey on rodents. Although, with the exception of kites, confirmed mortality from rodenticides was low, the widespread exposure recorded is concerning. Particularly when coupled with a lack of data about the sub-lethal effects of these compounds. This raises questions regarding whether statutory monitoring of use is needed; both to address whether there are deficiencies in compliance with approval conditions or whether the recommended risk management procedures are themselves adequate to protect non-target wildlife.

Improvements in sexual quality of life after moderate weight loss.

We evaluated changes in sexual quality of life as they relate to weight loss over a 2-year period in individuals undergoing weight loss treatment. Six dimensions of sexual quality of life were measured using items from the Impact of Weight on Quality of Life questionnaire (feeling sexually unattractive, lacking sexual desire, reluctance to be seen undressed, difficulty with sexual performance, avoidance of sexual encounters and lack of enjoyment of sexual activity). At baseline women were more likely than men to report lack of sexual enjoyment and reluctance to be seen undressed in spite of lower body mass index (BMI). Weight loss averaged 13.1% and was significantly associated with improvements in all sexual quality of life dimensions. A 3-4% regain did not appear to negatively affect sexual quality of life. The greatest improvements for women had occurred by 3 months and were observed in all dimensions, whereas for men only 'not feeling sexually attractive' showed marked improvement in this short time frame.

An evaluation of renal inpatient meals against Renal Nutrition Group standards.

BACKGROUND: The Renal Nutrition Group (RNG) of the British Dietetic Association has developed standards for the nutritional composition of meals provided to renal patients in hospital. However, no data are available as to whether these are achievable. The purpose of this study was to determine whether renal inpatient meals can meet the standards set by the RNG. METHOD: A prospective 10-day weighed food analysis of hospital meals provided to renal patients was undertaken. Two sample meals were analysed at each mealtime to include (1) the most energy dense choice and (2) the most frequent patient choice (FPC). RESULTS: Energy dense choice meals achieved the standard for protein provision on 90% of days, but provided too little energy on 100% of days (for men) and on 30% of days (for women). Although daily standards for potassium were met on 70% of days, those for sodium and phosphate were exceeded. FPC meals met the daily standards for potassium, sodium and phosphate on at least 80% of days, but provided too little protein on 40% of days and too little energy on 100% of days (for men and women). CONCLUSION: The majority of hospital meals fail to meet the RNG standards. Problems exist in providing sufficient energy and protein whilst restricting sodium, potassium and phosphate.

Temporal host-parasite relationships of the wild rabbit, Oryctolagus cuniculus (L.) as revealed by stable isotope analyses.

Natural abundances of the stable isotopes, 15N/14N (delta15N) and 13C/12C (delta13C), were used to study temporal host-parasite relationships of the wild rabbit, Oryctolagus cuniculus (L.). During the 12-month sampling period, temporal isotopic shifts in delta15N were noted for dietary vegetation, host rabbit faeces and fur, but not for muscle or stomach contents. delta15N varied temporally for the parasitic cestode species, Mosgovoyia pectinata but not for Cittotaenia denticulata. Similarly, intestinal parasitic nematodes had apparent species-specific delta15N patterns. Only rabbit fur and intestinal parasitic nematodes did not exhibit temporal shifts in delta13C. Overall, host faeces and stomach contents were isotopically indistinct as a likely consequence of coprophagy. Relative to their host, parasitic nematodes were 15N-enriched, consistent with an increase in trophic level status. Conversely, cestodes were 15N-depleted. Isotopically, each parasite reflected a species-specific relationship with their rabbit host. This technique could be utilized to integrate parasites into food-web studies.

Is decreased treatment time in hemodialysis patients harmful if solute clearance is maintained?

An association between decreased duration of hemodialysis and increased morbidity and mortality in patients has been suggested. Whether this is due only to decreased solute clearance is unclear. In this prospective randomised study the effect of reducing treatment time whilst maintaining constant solute clearance was examined in fourteen patients. The study lasted for a period of 36 weeks (3x12 week study periods) and used a crossover design. The patients dialysis prescription (KW) was not changed on entering the study and was maintained during short (150 minutes) and long dialysis (240 minutes) by varying blood flow, dialysate flow and dialyzer surface area. The delivered KW was kinetically assessed. Fractional urea clearance was also measured during each treatment period by measurement of urea concentration in spent dialysate and total body water using 3H2O. At the end of each treatment period a full biochemical and hematological profile, nutritional intake and status, 24 h ambulatory blood pressure, nerve conduction studies, and quality of life questionnaire were performed. Within patients the delivered single pool KW was uniform throughout the 3 treatment periods and fractional urea clearance did not vary. However, Kt/W assessed using equilibrated models (Daugardis and Smye) was significantly lower in the short dialysis period. No differences between short and long dialysis sessions were noted in any of the measured variables. Thus, over a 36 week period there is no evidence to suggest that hemodialysis patients are adversely affected by decreased duration of treatment provided that solute clearance is maintained.

The relationship between health-related quality of life and weight loss.

OBJECTIVE: This is a report of health-related quality of life (HRQOL) changes in obese patients completing at least 1 year of outpatient treatment in a weight reduction program combining phentermine-fenfluramine and dietary counseling. RESEARCH METHODS AND PROCEDURES: Participants were 141 women (87.6%) and 20 men (12.4%) who had an average body mass index at intake of 41.1 kg/m(2) (SD = 7.0, range = 29.5 to 67.0 kg/m(2)) and an average age of 44.9 years (SD = 9.3, range = 23 to 65 years). HRQOL was assessed at intake and at 1-year follow-up using the Impact of Weight on Quality of Life (IWQOL)-Lite questionnaire. The relationship between HRQOL changes and weight loss was examined using Pearson correlations. Clinically meaningful change in HRQOL was defined as a 1.96 SEM reduction in IWQOL-Lite total score. RESULTS: On average, participants lost 20.2 kg or 17.6% of their weight over the 1-year period. Of the participants, 15.5% lost <10% of their weight, 24.2% lost 10% to 14.9%, 23.6% lost 15% to 19.9%, and 36.6% lost 20% or more. All five IWQOL-Lite scales and total score showed statistically significant improvement over the 1-year period. Changes in IWQOL-Lite scores from intake to 1 year showed statistically significant correlations with percentage of weight loss for all subscales and total score. Subscale correlations with weight loss ranged from 0.166 (Public Distress) to 0.396 (Physical Function) and was 0.370 for the total score. Forty-four percent of participants losing <10% met the criterion of clinically meaningful change, compared with 51.3% losing 10% to 14.9%, 55.3% losing 15% to 19.95%, and 76.3% losing >20%. For total score and for three of the five IWQOL-Lite scales (Physical Function, Self-Esteem, and Sexual Life), the relationship between weight loss and clinically meaningful change was linear and was significant at p < 0.05. Physical Function and Self-Esteem were most strongly affected by weight loss. DISCUSSION: HRQOL changes, as measured by an obesity-specific instrument (IWQOL-Lite), are strongly related to weight reduction.

Nutritional status, delaying progression and risks associated with protein restriction.

Low protein diets (LPD), providing < or = 0.6 g protein/kg body weight daily, have traditionally been used in the nutritional management of chronic renal failure (CRF). Initially they were advocated when dialysis availability was limited. More recently LPD have been proposed as a means of delaying the rate of CRF progression. Despite much research in this area, the value of protein restriction remains contentious. A major concern over their use is that they may induce malnutrition. This is of critical importance since mortality rates are significantly increased in individuals who are malnourished when dialysis is initiated. Other approaches to the nutritional management of CRF may be more appropriate. The primary goal of any nutritional therapy should be to optimise the patient's nutritional status. In the UK LPD are used in a minority of units. An alternative approach to the use of these diets is to view the prevention of malnutrition as being of paramount importance. For uraemic patients, dialysis is the best treatment.

Rectal bleeding.

BACKGROUND: Rectal bleeding, although common, is frequently alarming to patients because of its association with bowel cancer. An understanding of the causes of rectal bleeding and a systematic approach to diagnosis provides the basis for preventive measures and appropriate treatment. OBJECTIVE: This article discusses the causes, history, examination and investigation of rectal bleeding according to the age of the patient. Treatment of the various conditions is outlined. DISCUSSION: Although haemorrhoids are the commonest cause of rectal bleeding, most patients over 40 years old presenting with this symptom require colonoscopy in order to screen for and treat premalignant polyps and colorectal cancer.

Diabetes disease stage predicts weight loss outcomes with long-term appetite suppressants.

OBJECTIVES: Characterize degree of weight loss with stage of diabetes and describe its effect on cardiovascular disease risk factors in obese patients with and without diabetes. RESEARCH METHODS AND PROCEDURES: Retrospective cohort analysis from patients participating in a long-term weight management protocol using diet, exercise, behavioral modification, and appetite-suppressant therapy. Patient groups, with (n = 19) and without diabetes (n = 19) were matched for age, gender, and weight before weight loss therapy. The effect of 12 months of therapy on weight, blood pressure, glycemic control, lipid profile, and medication requirements were tested. Additionally, patients were grouped or staged based upon therapy required for control of diabetes at the beginning of weight loss intervention. Analysis of covariance described relationships between diabetes disease stage and weight loss at 12 months. RESULTS: Nondiabetic patients had greater mean reduction in BMI than the diabetic group (7.98 kg/m2 vs. 4.77 kg/m2, p<0.01). A significant linear trend (p<0.001) for decreasing weight loss with stage of diabetes was observed. Blood pressure, lipid profile, and glycemia improved significantly. The average daily glyburide-equivalent dose decreased from 9.4 to 3.0 mg (p<0.01). DISCUSSION: Patients with diabetes lost less weight than similarly obese patients without diabetes. Regardless of differential weight loss between groups, cardiovascular disease risk factors improved. Hypoglycemic medication requirements decreased with weight loss therapy. A predictive relationship may exist between diabetes disease stage before weight loss therapy and future weight loss potential.

Evaluation of an opiate-weaning protocol using methadone in pediatric intensive care unit patients.

OBJECTIVE: To evaluate the efficacy of a standardized opiate-weaning protocol using methadone compared with methadone weaning before protocol development. DESIGN: Time series, prospective study with comparison to historical controls. SETTING: Twenty-bed medical-surgical intensive care unit in an academic children's hospital. PATIENTS: Ten children, aged 6 months to 18 yrs, who received methadone for weaning from continuous opiate infusions for >or=7 days compared with ten patients undergoing weaning by standardized protocol. INTERVENTIONS: Institution of standardized opiate-weaning protocol. MEASUREMENTS AND MAIN RESULTS: Patient age, gender, and diagnosis were similar in both nonprotocol (NP) and protocol (P) groups (p = NS). Days of opiate use were also similar between groups. Nine of ten NP and seven of ten P patients were on continuous fentanyl infusions, and the remainder were on continuous morphine infusions. P patients were weaned significantly faster than NP patients (median, 9 days and 20 days, respectively; p <.001). P patients requiring short-term opiate use also weaned significantly faster than short-term NP patients (median, 5 days and 21.5 days, respectively; p <.001). Withdrawal complications were seen in three NP patients with weaning delayed in two. Two P patients had withdrawal complications with no delay in weaning (p = NS). Significant methadone calculation discrepancy occurred in one NP patient but in no P patients. CONCLUSIONS: Pediatric intensive care unit patients requiring prolonged opiate use can be weaned by using methadone with minimal signs of withdrawal. Use of a standardized weaning protocol decreased time for weaning without increasing the frequency rate of withdrawal symptoms.

Comparison of air tonometry with gastric tonometry using saline and other equilibrating fluids: an in vivo and in vitro study.

OBJECTIVE: 1) To compare saline gastric tonometry monitoring with air tonometry (Tonocap) in a group of general ICU patients. 2) An in vitro investigation of the performance of other fluids used in gastric tonometry and to assess the effects of variation of temperature and carbon dioxide concentration within the range encountered in clinical use. DESIGN: a) A prospective, observational study in ICU patients b) A comparative laboratory study. SETTING: The general Intensive Care Unit (ICU) and the laboratory at Leeds General Infirmary. PATIENTS AND PARTICIPANTS: Nine patients in the general ICU with severe sepsis or septic shock. MEASUREMENTS AND RESULTS: In vivo comparison of saline and air tonometry demonstrated a difference between the two techniques. Bland & Altman analysis showed a mean bias in the measurement of gastric PCO2 of 1.88 kPa with a precision of 1.22 kPa, with saline giving the lower result. In vitro, saline, air (Tonocap), gelatin and heparinised blood were used, at temperatures of 33-42 degrees C and at carbon dioxide concentrations of 4-8 kPa. While gelatin and blood gave unpredictable results, dependent on temperature and carbon dioxide concentration, air tonometry gave highly reproducible results. A consistent bias between the results with saline and air tonometry was seen over the range of temperatures and carbon dioxide (CO2) concentrations studied. The mean bias was 0.85 kPa with a precision of 0.40 kPa, saline consistently giving lower results. CONCLUSIONS: There are clinically significant differences in values for gastric mucosal PCO2 measured by air tonometry and saline tonometry both in vivo and in vitro.

The prevalence of cardiac valvular insufficiency assessed by transthoracic echocardiography in obese patients treated with appetite-suppressant drugs.

BACKGROUND: After case reports of cardiac-valve abnormalities related to the use of appetite suppressants were published, we undertook a study to determine the prevalence of the problem using transthoracic echocardiography. METHODS: We examined patients who had taken dexfenfluramine alone, dexfenfluramine and phentermine, or fenfluramine and phentermine for various periods. We enrolled obese patients who had taken or were taking these agents during open-label trials from January 1994 through August 1997. We also recruited subjects who had not taken appetite suppressants and who were matched to the patients for sex, height, and pretreatment age and body-mass index. The presence of cardiac-valve abnormalities, defined by the Food and Drug Administration and Centers for Disease Control and Prevention as at least mild aortic-valve or moderate mitral-valve insufficiency, was determined independently by at least two cardiologists. Multivariate logistic-regression analysis was used to identify factors associated with cardiac-valve abnormalities. RESULTS: Echocardiograms were available for 257 patients and 239 control subjects. The association between the use of any appetite suppressant and cardiac-valve abnormalities was analyzed in a final matched group of 233 pairs of patients and controls. A total of 1.3 percent of the controls (3 of 233) and 22.7 percent of the patients (53 of 233) met the case definition for cardiac-valve abnormalities (odds ratio, 22.6; 95 percent confidence interval, 7.1 to 114.2; P<0.001). The odds ratio for such cardiac-valve abnormalities was 12.7 (95 percent confidence interval, 2.9 to 56.4) with the use of dexfenfluramine alone, 24.5 (5.9 to 102.2) with the use of dexfenfluramine and phentermine, and 26.3 (7.9 to 87.1) with the use of fenfluramine and phentermine. CONCLUSIONS: Obese patients who took fenfluramine and phentermine, dexfenfluramine alone, or dexfenfluramine and phentermine had a significantly higher prevalence of cardiac valvular insufficiency than a matched group of control subjects.

Platelet deposition after angioplasty is abolished by restoration of the endothelial cell monolayer.

PURPOSE: Percutaneous transluminal angioplasty of an atheromatous plaque causes endothelial desquamation and intimal dissection with the consequent formation of a thrombogenic flow surface. In this study we investigated the hypothesis that platelet deposition after balloon angioplasty may be decreased by rapid restoration of the endothelial cell monolayer, achieved by transluminally seeding angioplasty sites with endothelial cells. METHODS: Bilateral external iliac angioplasty was performed in eight New Zealand white rabbits. One angioplasty site was isolated from the circulation and incubated with a supraconfluent endothelial cell suspension with a double balloon catheter; the contralateral angioplasty site was sham seeded with culture medium. The deposition of autologous indium 111-labeled platelets on the angioplasty sites was quantified 30 minutes after restoration of flow and was referenced to an undamaged segment of aorta that acted as a negative control. RESULTS: Platelet deposition on the nonseeded angioplasty site (13.1 x 10(4) platelets/mm2) was significantly higher than on nondilated segments (3.4 x 10(4) platelets/mm2; p = 0.014). Restorationof endothelial cell coverage by endothelial seeding significantly reduced platelet deposition on dilated arterial segments to levels not significantly higher than in controls (3.6 x 10(4) platelets/mm2; p = 0.014). CONCLUSIONS: These results illustrate that rapid reendothelialization of angioplasty sites decreases subsequent platelet deposition and may reduce the rate of acute arterial reocclusion complicating endovascular techniques.

The effect of preformed confluent endothelial cell monolayers on the patency and thrombogenicity of small calibre vascular grafts.

Endothelial cell seeding has been proposed as a method to improve the patency rates in small calibre prosthetic vascular grafts. The seeding methods used at present leave much of the graft luminal surface devoid of endothelial cells and thus still significantly thrombogenic. We have developed a method to preform confluent endothelial cell monolayers, on the grafts prior to implantation, and this study investigates the effect of these monolayers on the early thrombogenicity and patency of polytetrafluoroethylene (PTFE) grafts. Small diameter PTFE grafts were seeded with canine endothelial cells obtained from the external jugular vein. Each of five dogs then received a graft seeded with its own cells and a contralateral, non-seeded control graft. At 1 and 10 weeks after graft implantation graft thrombogenicity was assessed by the use of Indium labelled platelets. The thrombogenicity index (TI) of each graft was determined from counts of gamma activity recorded over a period of 7 days. Grafts were subsequently removed at 12 weeks. At 1 week the mean TI for the seeded grafts was 0.123 (SD 0.019) and that for the controls 0.183 (SD 0.017) (p = 0.005). At 10 weeks only the seeded grafts could be assessed because all of the control grafts had occluded. At this point in time the seeded grafts had a mean TI of 0.159 (SD 0.011) (p = 0.047 vs. seeded at 1 week). By the time of removal at 12 weeks, all control grafts were occluded but only one of the seeded grafts had occluded (p = 0.025). In conclusion, the use of preformed, confluent endothelial cell monolayers for seeding prosthetic grafts significantly reduces the early graft thrombogenicity and improves graft patency. It does not, however, completely halt the increase in thrombogenicity which occurs during the early post-implantation period.

Comparative anatomic study of anterior and posterior iliac crests as donor sites.

Ten fixed human cadaver iliums from elderly persons were studied to compare the amounts of graft material present in the anterior and posterior ilium. Average intracortical volume of surgically accessible marrow space was 15.75 mL for the anterior and 39.24 mL for the posterior ilium. Comparison of marrow volume underlying equal surface areas revealed values of 8.4 mL for the anterior and 14.8 mL for the posterior ilium. The average total volume of compressed cancellous bone obtained was 12.87 mL for the anterior and 30.31 mL for the posterior ilium. The ratio of cortical bone window surface area to resultant immediately accessible graft material was 1:0.49 for the anterior and 1:0.75 for the posterior ilium. These results confirm the greater availability of cancellous bone in the posterior ilium.

Blood pressure, heart rate and neuroendocrine responses to a high carbohydrate and a high fat meal in healthy young subjects.

1. The responses of blood pressure, heart rate, autonomic function and plasma insulin to a high carbohydrate and a high fat meal of equivalent energy value were studied in nine young volunteers. 2. Neither meal produced a significant change in supine or erect blood pressure. The high carbohydrate meal, however, resulted in an overall rise in both supine (6 beats/min) and erect (6 beats/min; P less than 0.05) heart rate, no such changes being seen after the high fat meal. 3. Plasma noradrenaline levels increased by a maximum of 126% at 90 min (0.98 to 2.22 nmol/l) after the high carbohydrate meal but were virtually unchanged after the high fat meal (P less than 0.01). Parasympathetic function showed no between-meal differences. Plasma insulin and glucose levels were significantly higher after the high carbohydrate meal than after the high fat meal. No postprandial difference in packed cell volume was found between meal types. 4. We conclude that, in young subjects, the postprandial blood pressure after a high carbohydrate meal is maintained by an increase in heart rate associated with increased sympathetic nervous system activity. These changes are at variance with the blood pressure and heart rate responses seen in the elderly after a high carbohydrate meal. A high fat meal has no significant cardiovascular or neuroendocrine effects in the young or old. The nutrient composition of meals has to be taken into account when studying the postprandial cardiovascular and neuroendocrine responses in the young.