Search

Introduction: Discrepant data exists regarding the outcomes following total knee arthroplasty (TKA) with a prior anterior cruciate reconstruction (ACLR). The purpose of our study was to compare surgical and medical outcomes in the patients with prior ACLR undergoing TKAs compared to a matched control group of the patients who had undergone TKAs without prior ACLR. We hypothesized that the patients with prior ACLR would have inferior clinical outcomes., Material/methods: We retrospectively queried the PearlDiver-database for patients who underwent TKA following ACLR from 2011 to 2020. We used propensity-score matching to create two cohorts. The two-sided independent t-test and Chi-Squared test were used., Results: We identified 2,174 patients who had prior ACLR before the TKAs. There were another 1,348,870 patients who did not have ACLR before the TKAs. After matching, each group had 2,171 patients. The ACLR-TKA group had significantly lower rates of aseptic revision at 2 years (1.2% vs. 4.0%, OR 0.3, p < 0.01), PJI requiring antibiotic spacer at 2 years (0.3% vs. 0.8%, OR 0.35, p = 0.02), and MUA at 90 days (0.4% vs. 7.5%, OR 0.05, p < 0.01). The rate of wound disruption was lower for the ACLR-TKA group at 90 days (p = 0.03) as were several medical complications including AKI at 90 days (p < 0.01), DVT at 90 days (p < 0.01), pneumonia at 90 days (0.04), and required blood transfusion at 90 days (p < 0.01)., Conclusion: These results differed from our expectations. Within the limitations of the study, we are unable to determine the factors for the lower complications in the ACLR-TKA group. The data from this study are different from what had been reported in the previous studies., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Early dislocation following primary total hip arthroplasty (THA) is a rare but devastating complication and represents a source of patient morbidity and financial burden to the healthcare system. The objective of this study was to identify patient characteristics and comorbidities that are associated with increased early in-hospital dislocation rates following primary THA. Methods: A retrospective cohort study was conducted using patient data from the Nationwide Inpatient Sample (NIS) database; we identified patients who had undergone THA from 2016 to 2019 and compared those with an early periprosthetic dislocation prior to discharge to those without. The patient characteristics and comorbidities were compared using univariate analysis with a subsequent investigation of statistically significant variables using multivariate analysis. The variables were compared using chi square, Fisher's exact test, and independent sample t-tests with data assessed using odds ratio with 95% confidence intervals. Results: A total of 5151 patients sustained an early dislocation compared to 362,743 who did not. Those who sustained an in-hospital dislocation were more likely to share the following characteristics: female sex (OR 1.21, p < 0.01), age > 70 (OR 1.45, p < 0.01), Caucasian ethnicity (OR 1.22, p < 0.01), SLE (OR 1.87, p < 0.01), and Parkinson's disease (OR 1.93, p < 0.01). Certain characteristics were also associated with decreased odds of having an in-hospital dislocation including elective surgery (OR 0.14, p < 0.01), tobacco use (OR 0.8, p < 0.01), diabetes without complications (OR 0.87, p < 0.01), and a history of heart valve replacement (OR 0.81, p < 0.01). The length of stay was significantly longer (4.7 days vs. 2.3 days) as was the total hospital charges (USD $101,517 vs. USD $66,388) for the early in-hospital dislocation group. Conclusions: Several patient characteristics and comorbidities are associated with early in-hospital dislocation episodes following total hip arthroplasty including female sex, age > 70, non-elective surgery, SLE, and Parkinson's. This information may be useful to help guide intraoperative implant selection and/or postoperative protocol in select patient populations to limit early instability as well as decrease the financial burden associated with this postoperative complication.

Objectives: Reverse total shoulder arthroplasty (RTSA) continues to increase in popularity as a surgical operation in the United States. As indications for this procedure expand, more attention is needed to evaluate perioperative risk factors and patient characteristics. Postoperative anemia requiring blood transfusion (BT) is a well-documented risk factor for increased in-house mortality although little has been studied on the relationship between RTSA and postoperative BT. The purpose of this study was to identify comorbidities and patient characteristics as risk factors for BT in patient's undergoing RTSA., Methods: Using the Nationwide Inpatient Sample (NIS) database, 59,925 RTSA patients (2016-2019) were analyzed, with 1.96% requiring postoperative BT. Demographics, comorbidities, and preoperative factors were compared between BT and non-BT groups via univariate and multivariate analyses., Results: Overall prevalence of blood transfusion in all patients was 1.96%. Male sex (OR 1.75, p < 0.001), Asian ethnicity (OR 1.96, p = 0.012), age >80 (OR 1.51, p < 0.001), age >90 (OR 2.26, p < 0.001), CKD (OR 1.94, p < 0.001), and Parkinson's disease (OR 2.08, p < 0.001) were associated with increased BT odds. Cirrhosis exhibited the highest impact (OR 5.7, p < 0.001). Conversely, Caucasian ethnicity (OR 0.76, p = 0.023), uncomplicated DM (OR 0.73, p = 0.002), tobacco-related disorders (OR 0.43, p < 0.001), BMI >30 (OR 0.8, p = 0.011), and elective procedures (OR 0.16, p < 0.001) decreased BT odds., Conclusion: These results were useful with identifying several risk factors that predispose to a higher risk of postoperative BT in patients undergoing RTSA including male sex, people of Asian descent, age > 80, CKD, Parkinson's disease, and cirrhosis. These findings provide clinicians with information that may be helpful with preoperative planning and perioperative management of complex patient populations., Competing Interests: The author(s) do NOT have any potential conflicts of interest for this manuscript., (2024 © BY THE ARCHIVES OF BONE AND JOINT SURGERY.)

Zone II flexor tendons present unique challenges for repair because of their complex anatomy in a confined space. The approach for zone II injuries is often dictated by preexisting traumatic skin lacerations, with a midaxial or volar approach being most common. In some injuries, this approach is not viable, and alternative approaches must be considered. A 45-year-old man presented with a traumatic crush injury that caused complete disruption of the skin, tendon, capsule, collateral ligament, and volar plate and laceration of the flexor digitorum profundus in zone II near the proximal interphalangeal joint. Given the large, near-circumferential zone of injury, we used the traumatic dorsal wound for the flexor tendon for repair. There are no reports of this approach in the literature. Postoperatively, the proximal interphalangeal joint was immobilized for 6 weeks with a K-wire. The patient was followed in the clinic and prescribed occupational therapy. At the 4-month postoperative visit, the patient had a healed incision, no signs of infection, and intact median/radial sensations. Functional testing showed a loose composite fist, improved range of motion, and 2-cm tip-to-palm deficiency of the index finger. Grip strength was 85 lb in the right hand and 60 lb in the left hand. Although patients are not always expected to regain full function, their postoperative course may be further complicated by adhesion and the need for tenolysis. Given these historical complications of tendon repair and our patient's ability to return to work with satisfactory functional outcomes, this approach may be a viable option for treating this unique injury pattern. [ Orthopedics . 2022;45(4):e216-e219.].

Metastatic cutaneous SCC carries a poor prognosis with five-year survival of 25%-57%. The aim of this study is to examine the outcomes following surgery with adjuvant therapy for management of metastatic cSCC in a UK-based population. This is a retrospective review of patients with metastatic cSCC of the head and neck who underwent primary surgery at a regional center during a six-year period. Overall and disease specific survival were calculated using Kaplan-Meier and log-rank tests. Results were reported as hazard ratios (HR) with 95% confidence intervals. Forty-five patients met the inclusion criteria. The mean time to discovery of metastases was 9.3 months (range, 0-40 months). Only two patients (4%) had discovery of metastases after two years, with none after 3.3 years. The overall five5-year survival was 31% (95% CI 15%to 48%) with two-year survival at 48% (95% CI 31%to 63%). The median OS survival was 722 days (95% CI 607to 1359). Patients aged >80 years had a decreased OS. This is the largest UK based study documenting the overall and disease specific survival associated with metastatic cutaneous SCC of the head and neck. Our overall survival is comparable to similar studies, but remains poor. Total number of involved nodes, and lymph node ratio were not statistically significant., (Crown Copyright © 2021. Published by Elsevier Ltd. All rights reserved.)

In this study liver tumours produced in male and female mice of the low spontaneous liver tumour incidence C57BL/10J strain treated for 99 weeks with 1000 ppm in the diet with the model constitutive androstane receptor (CAR) activator sodium phenobarbital (NaPB) were analysed for β-catenin mutations by Western immunoblotting and DNA/RNA analysis. Some gene array analysis was also performed to identify genes involved in CAR activation and in β-catenin and Hras gene mutations. Analysis of 8 male and 2 female NaPB-induced liver tumour samples (comprising 2 adenomas, 6 carcinomas and 2 samples containing separate adenomas and carcinomas) revealed truncated β-catenin forms in just 4 male liver tumour samples, with the presence of the truncated β-catenin forms being confirmed by β-catenin exon 1-3 mutation analysis. Microarray gene expression analysis was performed with three of the NaPB-induced male mouse liver tumour samples where β-catenin mutations had not been identified by Western immunoblotting and DNA/RNA analysis and with three liver samples from both NaPB-induced non-tumour tissue and control animals. Treatment with NaPB resulted in induction of Cyp2b subfamily gene expression in both NaPB-induced mouse liver tumours and in NaPB-treated non-tumour tissue. In addition, the gene expression analysis demonstrated that the β-catenin and Hras pathways were not modified in NaPB-induced mouse liver tumours not exhibiting truncated β-catenin forms. Overall, while chronic administration of the model CAR activator NaPB results in both hepatocellular adenoma and carcinoma in the low spontaneous liver tumour incidence C57BL/10J mouse strain, only 40 % of the liver tumours evaluated in this study had β-catenin mutations. These results are in agreement with previous studies with the CAR activator oxazepam and demonstrate that mouse liver tumours induced by nongenotoxic CAR activators in the absence of initiation with a genotoxic agent are due to a number of mechanisms, including those largely independent of either the Wnt/β-catenin signalling pathway or Hras oncogene mutations., (Copyright © 2019 Elsevier B.V. All rights reserved.)

UBQLN2 450-624 oligomerizes and undergoes temperature-responsive liquid-liquid phase transitions following a closed-loop temperature-concentration phase diagram. We recently showed that disease-linked mutations to UBQLN2 450-624 impart highly varying effects to its phase behavior, ranging from little change to significant decrease of saturation concentration and formation of gels and aggregates. However, how single mutations lead to these properties is unknown. Here, we use UBQLN2 450-624 as a model system to study the sequence determinants of phase separation. We hypothesized that UBQLN2 450-624 regions previously identified to promote its oligomerization are the "stickers" that drive interchain interactions and phase separation. We systematically investigated how phase behavior is affected by all 19 possible single amino acid substitutions at three sticker and two "spacer" (sequences separating stickers) positions. Overall, substitutions to stickers, but not spacers, substantially altered the shape of the phase diagram. Within the sticker regions, increasing hydrophobicity decreased saturation concentrations at low temperatures and enhanced oligomerization propensity and viscoelasticity of the dense phase. Conversely, substitutions to acidic residues at all positions greatly increased saturation concentrations. Our data demonstrate that single amino acid substitutions follow a molecular code to tune phase transition behavior of biopolymers.

The distribution, metabolism, excretion and hepatic effects of the human hepatotoxin fenclozic acid were investigated following single oral doses of 10 mg/kg to normal and bile duct-cannulated male C57BL/6J mice. Whole body autoradiography showed distribution into all tissues except the brain, with radioactivity still detectable in blood, kidney and liver at 72 h post-dose. Mice dosed with [ 14 C]-fenclozic acid showed acute centrilobular hepatocellular necrosis, but no other regions of the liver were affected. The majority of the [ 14 C]-fenclozic acid-related material recovered was found in the urine/aqueous cage wash, (49%) whilst a smaller portion (13%) was eliminated via the faeces. Metabolic profiles for urine, bile and faecal extracts, obtained using liquid chromatography and a combination of mass spectrometric and radioactivity detection, revealed extensive metabolism of fenclozic acid in mice that involved biotransformations via both oxidation and conjugation. These profiling studies also revealed the presence of glutathione-derived metabolites providing evidence for the production of reactive species by mice administered fenclozic acid. Covalent binding to proteins from liver, kidney and plasma was also demonstrated, although this binding was relatively low (less than 50 pmol eq./mg protein).

Hepatic NADPH-cytochrome P450 oxidoreductase null (HRN™) mice exhibit no functional expression of hepatic cytochrome P450 (P450) when compared to wild type (WT) mice, but have normal hepatic and extrahepatic expression of other biotransformation enzymes. We have assessed the utility of HRN™ mice for investigation of the role of metabolic bioactivation in liver toxicity caused by the nonsteroidal anti-inflammatory drug (NSAID) fenclozic acid. In vitro studies revealed significant NADPH-dependent ( i.e. P450-mediated) covalent binding of [ 14 C]-fenclozic acid to liver microsomes from WT mice and HRN™ mice, whereas no in vitro covalent binding was observed in the presence of the UDP-glucuronyltransferase cofactor UDPGA. Oral fenclozic acid administration did not alter the liver histopathology or elevate the plasma liver enzyme activities of WT mice, or affect their hepatic miRNA contents. Livers from HRN™ mice exhibited abnormal liver histopathology (enhanced lipid accumulation, bile duct proliferation, hepatocellular degeneration, necrosis, inflammatory cell infiltration) and plasma clinical chemistry (elevated alanine aminotransferase, glutamate dehydrogenase and alkaline phosphatase activities). Modest apparent improvements in these abnormalities were observed when HRN™ mice were dosed orally with fenclozic acid for 7 days at 100 mg kg -1 day -1 . Previously we observed more marked effects on liver histopathology and integrity in HRN™ mice dosed orally with the NSAID diclofenac for 7 days at 30 mg kg -1 day -1 . We conclude that HRN™ mice are valuable for assessing P450-related hepatic drug biotransformation, but not for drug toxicity studies due to underlying liver dysfunction. Nonetheless, HRN™ mice may provide novel insights into the role of inflammation in liver injury, thereby aiding its treatment.

Gram-negative pathogens often use conserved type three secretion systems (T3SS) for virulence. The Shigella type three secretion apparatus (T3SA) penetrates the host cell membrane and provides a unidirectional conduit for injection of effectors into host cells. The protein Spa47 localizes to the base of the apparatus and is speculated to be an ATPase that provides the energy for T3SA formation and secretion. Here, we developed an expression and purification protocol, producing active Spa47 and providing the first direct evidence that Spa47 is a bona fide ATPase. Additionally, size exclusion chromatography and analytical ultracentrifugation identified multiple oligomeric species of Spa47 with the largest greater than 8 fold more active for ATP hydrolysis than the monomer. An ATPase inactive Spa47 point mutant was then engineered by targeting a conserved Lysine within the predicted Walker A motif of Spa47. Interestingly, the mutant maintained a similar oligomerization pattern as active Spa47, but was unable to restore invasion phenotype when used to complement a spa47 null S. flexneri strain. Together, these results identify Spa47 as a Shigella T3SS ATPase and suggest that its activity is linked to oligomerization, perhaps as a regulatory mechanism as seen in some related pathogens. Additionally, Spa47 catalyzed ATP hydrolysis appears to be essential for host cell invasion, providing a strong platform for additional studies dissecting its role in virulence and providing an attractive target for anti-infective agents., (© 2016 The Protein Society.)

Background: A quality improvement initiative was created during the 2014 Africa Goal campaign, which uses live screenings of FIFA World Cup football matches as a platform for local organizations to provide HIV outreach and services in East and Southern Africa., Materials and Methods: Survey data assessed attendees' baseline knowledge of HIV and prevalence of prior testing., Results: The data showed a high level of knowledge and prior testing among both men and women, with no statistical differences based on gender., Conclusion: The level of knowledge about HIV may be higher than previously thought in some parts of East and Southern Africa and this should inform future HIV outreach efforts.

Hepatic NADPH-cytochrome P450 oxidoreductase null (HRN™) mice exhibit normal hepatic and extrahepatic biotransformation enzyme activities when compared to wild-type (WT) mice, but express no functional hepatic cytochrome P450 activities. When incubated in vitro with [(14)C]-diclofenac, liver microsomes from WT mice exhibited extensive biotransformation to oxidative and glucuronide metabolites and covalent binding to proteins was also observed. In contrast, whereas glucuronide conjugates and a quinone-imine metabolite were formed when [(14)C]-diclofenac was incubated with HRN™ mouse liver, only small quantities of P450-derived oxidative metabolites were produced in these samples and covalent binding to proteins was not observed. Livers from vehicle-treated HRN™ mice exhibited enhanced lipid accumulation, bile duct proliferation, hepatocellular degeneration and necrosis and inflammatory cell infiltration, which were not present in livers from WT mice. Elevated liver-derived alanine aminotransferase, glutamate dehydrogenase and alkaline phosphatase activities were also observed in plasma from HRN™ mice. When treated orally with diclofenac for 7 days, at 30 mg/kg/day, the severities of the abnormal liver histopathology and plasma liver enzyme findings in HRN™ mice were reduced markedly. Oral diclofenac administration did not alter the liver histopathology or elevate plasma enzyme activities of WT mice. These findings indicate that HRN™ mice are valuable for exploration of the role played by hepatic P450s in drug biotransformation, but poorly suited to investigations of drug-induced liver toxicity. Nevertheless, studies in HRN™ mice could provide novel insights into the role played by inflammation in liver injury and may aid the evaluation of new strategies for its treatment.

Dispersal plays a crucial role in many aspects of species' life histories, yet is often difficult to measure directly. This is particularly true for many insects, especially nocturnal species (e.g. moths) that cannot be easily observed under natural field conditions. Consequently, over the past five decades, laboratory tethered flight techniques have been developed as a means of measuring insect flight duration and speed. However, these previous designs have tended to focus on single species (typically migrant pests), and here we describe an improved apparatus that allows the study of flight ability in a wide range of insect body sizes and types. Obtaining dispersal information from a range of species is crucial for understanding insect population dynamics and range shifts. Our new laboratory tethered flight apparatus automatically records flight duration, speed, and distance of individual insects. The rotational tethered flight mill has very low friction and the arm to which flying insects are attached is extremely lightweight while remaining rigid and strong, permitting both small and large insects to be studied. The apparatus is compact and thus allows many individuals to be studied simultaneously under controlled laboratory conditions. We demonstrate the performance of the apparatus by using the mills to assess the flight capability of 24 species of British noctuid moths, ranging in size from 12-27 mm forewing length (~40-660 mg body mass). We validate the new technique by comparing our tethered flight data with existing information on dispersal ability of noctuids from the published literature and expert opinion. Values for tethered flight variables were in agreement with existing knowledge of dispersal ability in these species, supporting the use of this method to quantify dispersal in insects. Importantly, this new technology opens up the potential to investigate genetic and environmental factors affecting insect dispersal among a wide range of species.

Understanding the complex movement patterns of animals in natural environments is a key objective of 'movement ecology'. Complexity results from behavioural responses to external stimuli but can also arise spontaneously in their absence. Drawing on theoretical arguments about decision-making circuitry, we predict that the spontaneous patterns will be scale-free and universal, being independent of taxon and mode of locomotion. To test this hypothesis, we examined the activity patterns of the European honeybee, and multiple species of noctuid moth, tethered to flight mills and exposed to minimal external cues. We also reanalysed pre-existing data for Drosophila flies walking in featureless environments. Across these species, we found evidence of common scale-invariant properties in their movement patterns; pause and movement durations were typically power law distributed over a range of scales and characterized by exponents close to 3/2. Our analyses are suggestive of the presence of a pervasive scale-invariant template for locomotion which, when acted on by environmental cues, produces the movements with characteristic scales observed in nature. Our results indicate that scale-finite complexity as embodied, for instance, in correlated random walk models, may be the result of environmental cues overriding innate behaviour, and that scale-free movements may be intrinsic and not limited to 'blind' foragers as previously thought.

Diacylglycerol O-acyltransferase 1 (DGAT1) plays an important role in synthesizing lipids, and inhibitors of DGAT1 have been investigated as potential treatments for diabetes and metabolic diseases. DGAT1 knockout (-/-) mice are resistant to obesity, have increased sensitivity to insulin, and exhibit sebaceous gland atrophy and alopecia. Prolonged pharmacological inhibition of DGAT1 with AZD7687 in mice results in the same skin phenotype, including sebaceous gland atrophy and alopecia, as seen in the skin of DGAT1 (-/-) mice. AZD7687-mediated effects on the skin were dose- and time-dependent and reversible. They occurred only at substantial levels of continuous DGAT1 inhibition. Prolonged treatment of dogs with AZD7687 also resulted in sebaceous gland atrophy but did not result in the more adverse skin changes of hair loss and skin lesions. Our findings highlight a significant risk of generating the same lesions that were seen in mouse skin during clinical development of DGAT1 inhibitors in humans and also reveal a species difference in the effects on the skin, indicating that the mouse may be an especially sensitive species. Therefore, although human therapeutic doses may not have the same influence on skin morphology as seen in mice, monitoring of skin changes will be essential in clinical trials with DGAT1 inhibitors., (© 2014 by The Author(s).)

Pharmaceutical therapies for non-insulin-dependent diabetes mellitus (NIDDM) include plasma glucose lowering by enhancing glucose utilization. The mitochondrial pyruvate dehydrogenase (PDH) complex is important in controlling the balance between glucose and fatty acid substrate oxidation. Administration of pyruvate dehydrogenase kinase inhibitors (PDHKIs) to rats effectively lowers plasma glucose but results in myocardial steatosis that in some instances is associated primarily with atrial and to a lesser degree with ventricular pathology. Induction of myocardial steatosis is not dose-dependent, varies from minimal to moderate severity, and is either of multifocal or diffuse distribution. Ventricular histopathology was restricted to few myocardial degenerative fibers, while that in the atrium/atria was of either acute or chronic appearance with the former showing myocardial degeneration/necrosis, acute myocarditis, edema, endothelial activation (rounding up), endocarditis, and thrombosis associated with moderate myocardial steatosis and the latter with myocardial loss, replacement fibrosis, and no apparent or minimal association with steatosis. The evidence from these evaluations indicate that excessive intramyocardial accumulation of lipid may be either primarily adverse or represents an indicator of other adversely affected cellular processes., (© 2014 by The Author(s).)

Background and Purpose: Pharmacological activation of glucokinase (GK) lowers blood glucose in animal models and humans, confirming proof of concept for this mechanism. However, recent clinical evidence from chronic studies suggests that the glucose-lowering effects mediated by glucokinase activators (GKAs) are not maintained in patients with type 2 diabetes (T2D). Existing preclinical data with GKAs do not explain this loss of sustained glucose-lowering efficacy in patients. Here, we have assessed the effects of chronic (up to 11 months) treatment with two different GKAs in two models of T2D., Experimental Approach: Two validated animal models of T2D, insulin-resistant obese Zucker rats and hyperglycaemic gk(wt/del) mice, were treated with two different GKAs for 1 or 11 months respectively at exposures that translate to clinical exposures in humans. Blood glucose, cholesterol, triglycerides and insulin were measured. GKA pharmacokinetics were also determined., Key Results: Treatment with either GKA provided sustained lowering of blood glucose for up to 1 month in the Zucker rat and up to 11 months in hyperglycaemic gk(wt/del) mice, with maintained compound exposures. This efficacy was achieved without increases in plasma or hepatic triglycerides, accumulation of hepatic glycogen or impairment of glucose-stimulated insulin secretion., Conclusions and Implications: Chronic treatment with two GKAs in two animal models of diabetes provided sustained lowering of blood glucose, in marked contrast to clinical findings. Therefore, either these animal models of T2D are not good predictors of responses in human T2D or we need a better understanding of the consequences of GK activation in humans.

Malignancy within a thyroglossal duct cyst is rare (1.5% of cases), and most diagnoses are made postoperatively as clinically they are difficult to distinguish from benign neoplasms. We present a case in which a preoperative ultrasound scan showed the presence of a central solid component in a thyroglossal duct cyst, which contained papillary thyroid carcinoma., (Copyright © 2013 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Antagonism of the effects of glucagon as an adjunct therapy with other glucose-lowering drugs in the chronic treatment of diabetes has been suggested to aggressively control blood glucose levels. Antagonism of glucagon effects, by targeting glucagon secretion or disabling the glucagon receptor, is associated with α-cell hyperplasia. We evaluated the influence of total glucagon withdrawal on islets of Langerhans using prohormone convertase-2 knockout mice (PC2-ko), in which α-cell hyperplasia is present from a young age and persists throughout life, in order to understand whether or not sustained glucagon deficit would lead to islet tumorigenesis. PC2-ko and wild-type (WT) mice were maintained drug-free, and cohorts of these groups sampled at 3, 12 and 18 months for plasma biochemical and morphological (histological, immunohistochemical, electron microscopical and image analytical) assessments. WT mice showed no islet tumours up to termination of the study, but PC2-ko animals displayed marked changes in islet morphology from α-cell hypertrophy/hyperplasia/atypical hyperplasia, to adenomas and carcinomas, these latter being first encountered at 6-8 months. Islet hyperplasias and tumours primarily consisted of α-cells associated to varying degrees with other islet endocrine cell types. In addition to substantial increases in islet neoplasia, increased α-cell neogenesis associated primarily with pancreatic duct(ule)s was present. We conclude that absolute blockade of the glucagon signal results in tumorigenesis and that the PC2-ko mouse represents a valuable model for investigation of islet tumours and pancreatic ductal neogenesis., (© 2014 The Authors. International Journal of Experimental Pathology © 2014 International Journal of Experimental Pathology.)

1. The distribution, metabolism, excretion and hepatic effects of fenclozic acid were investigated following a single oral dose of 10 mg/kg to hepatic reductase null (HRN) mice. 2. The majority of the [(14)C]-fenclozic acid was eliminated via the urine/aqueous cage wash, (55%) with a smaller portion excreted in the faeces, (5%). The total recovery of radioactivity in the excreta over the 72 h period studied was ca. 60%. 3. Metabolism of fenclozic acid in the HRN mice was entirely to the carboxylic acid function and was dominated by amino acid conjugation to glycine and taurine, with lesser amounts of an acyl glucuronide. 4. Whole body autoradiography of mice showed general distribution into all tissues except the brain. Radioactivity was still detectable in the kidney and liver of the HRN mice at 72 h post-dose. Covalent binding studies showed evidence of binding to kidney, liver and plasma proteins however, the degree of binding was less than 50 pmol equiv/mg protein for all tissues. 5. The HRN mouse appears to be a useful in vivo model for the study of the Phase II conjugation metabolism of fenclozic acid in the absence of hepatic cytochrome P450-related oxidative metabolism.

In recent years, there has been considerable activity to identify urinary biomarkers of nephrotoxicity as noninvasive measurements with greater sensitivity and specificity than traditional biomarkers, such as serum creatinine and blood urea nitrogen. Our study aimed to use cisplatin-treated rats to evaluate the use of immunohistochemistry directed at multiple urinary biomarkers in kidney tissue. Tissue levels were compared to urinary levels of these biomarkers to demonstrate tissue specificity and sensitivity. These techniques could also be used in studies where urine samples are not available, such as retrospective studies in drug safety testing, to demonstrate the potential utility of using these biomarkers in future preclinical or clinical studies. All of the biomarkers investigated showed either an increase (kidney injury molecule [KIM-1], osteopontin [OPN], and, clusterin) or a decrease (alpha-glutathione S-transferase and trefoil factor 3) except beta 2 microglobulin (β2MG) that showed no significant changes 5 days after 1.0 mg/kg or 2.5 mg/kg cisplatin treatment. All of the biomarkers except β2MG showed utility as tissue biomarkers, but KIM-1 and OPN expression correlated closely with urinary biomarker measurements and reflect tissue damage. Future studies are needed to determine the wider application of these two markers for detecting renal toxicity following administration of other nephrotoxicants.

Drug-induced liver injury (DILI) is a clinically important adverse drug reaction, which prevents the development of many otherwise safe and effective new drugs. Currently, there is a lack of sensitive and specific biomarkers that can be used to predict, assess and manage this toxicity. The aim of this work was to evaluate gadoxetate-enhanced MRI as a potential novel biomarker of hepatobiliary transporter inhibition in the rat. Initially, the volume fraction of extracellular space in the liver was determined using gadopentetate to enable an estimation of the gadoxetate concentration in hepatocytes. Using this information, a compartmental model was developed to characterise the pharmacokinetics of hepatic uptake and biliary excretion of gadoxetate. Subsequently, we explored the impact of an investigational hepatobiliary transporter inhibitor on the parameters of the model in vivo in rats. The investigational hepatobiliary transporter inhibitor reduced both the rate of uptake of gadoxetate into the hepatocyte, k1 , and the Michaelis-Menten constant, Vmax , characterising its excretion into bile, whereas KM values for biliary efflux were increased. These effects were dose dependent and correlated with effects on plasma chemistry markers of liver dysfunction, in particular bilirubin and bile acids. These results indicate that gadoxetate-enhanced MRI provides a novel functional biomarker of inhibition of transporter-mediated hepatic uptake and clearance in the rat. Since gadoxetate is used clinically, the technology has the potential to provide a translatable biomarker of drug-induced perturbation of hepatic transporters that may also be useful in humans to explore deleterious functional alterations caused by transporter inhibition., (Copyright © 2013 John Wiley & Sons, Ltd.)

We evaluated immunohistochemistry (von Willebrand Factor [vWF] or fibrinogen) and systemic and coronary arterial physiological parameters in beagle dogs to investigate early arterial lesions induced by the potassium channel opener, ZD6169, or the endothelin receptor antagonist, ZD1611. Dogs given an oral dose of ZD6169 (experiment 1) were terminated 1 day later and showed arterial and myocardial lesions. Minimal arterial lesions exhibited few condensed medial smooth muscle cells only, with others showing segmental medial necrosis occasionally with medial/adventitial acute inflammation. Intercellular immunostaining was seen in ostensibly normal tissue, where no pathology was present in conventionally stained sections. vWF and fibrinogen are valuable tools for detecting disruption of arterial integrity. In experiment 2, 2 dogs were given a single high dose of ZD6169 or ZD1611 and BP/HR monitored by conventional measures or telemetry. Substantially reduced systolic/diastolic BP and increased HR occurred within 10 min of ZD6169 infusion: ZD1611 caused minor BP decrease and HR increase. In experiment 3, both drugs given to anaesthetized dogs induced markedly exaggerated systolic phasic forward and reverse flow in left descending and right coronary arteries. Diastolic coronary artery flows were unaffected with ZD1611 and increased slightly with ZD6169. In both coronary arteries, the ZD1611-induced increase in flows paralleled decreased resistance.

Acyl-coenzyme A: cholesterol O-Acyltransferase (ACAT) and Acyl-coenzyme A: diacylglycerol O-acyltransferase (DGAT) enzymes play important roles in synthesizing neutral lipids, and inhibitors of these enzymes have been investigated as potential treatments for diabetes and other metabolic diseases. Administration of a Acyl-coenzyme A: diacylglycerol O-acyltransferase 1 (DGAT1) inhibitor with very limited cellular selectivity over ACAT resulted in significant adrenocortical degenerative changes in dogs. These changes included macrosteatotic vacuolation associated with adrenocyte cell death in the zonae glomerulosa and fasciculata and minimal to substantial mixed inflammatory cell infiltration and were similar to those described previously for some ACAT inhibitors in dogs. In the mouse, similar but only transient adrenocortical degenerative changes were seen as well as a distinctive nondegenerative reduction in cortical fine vacuolation. In the marmoset, only the distinctive nondegenerative reduction in cortical fine vacuolation was observed, suggesting that the dog, followed by the mouse, is the most sensitive species for cortical degeneration. Biochemical analysis of adrenal cholesterol and cholesteryl ester indicated that the distinctive reduction in cortical fine vacuolation correlated with a significant reduction in cholesteryl ester in the mouse and marmoset, whereas no significant reduction in cholestryl ester, but an increase in free cholesterol was observed in dogs. Administration of a DGAT1 inhibitor with markedly improved selectivity over ACAT to the marmoset and the mouse resulted in no adrenal pathology at exposures sufficient to cause substantial DGAT1 but not ACAT inhibition, thereby implicating ACAT rather than DGAT1 inhibition as the probable cause of the observed adrenal changes. Recognizing that the distinctive nondegenerative reduction in cortical fine vacuolation in the mouse could be used as a histopathological biomarker for an in vivo model of the more severe changes observed in dogs, the mouse has subsequently been used as a model to select DGAT1 inhibitors free of adrenocortical toxicity.

Islets of Langerhans represent a heterogeneous population in insulin resistant and diabetic animals and humans as histological appearances and function vary substantially. Mathematical representation that reflects this morphological diversity will assist in assessment of degeneration and regeneration, enabling comparisons between species, strains, and experimental investigations. Our investigative approach used a model of islet degeneration in diabetic male obese Zucker Diabetic Fatty (ZDF) rats and evaluated its prevention using rosiglitazone treatment. Immunohistochemical staining (insulin and collagens I/III) with automated image analysis reliably measured numbers, area, clustering, and staining intensity of β-cells and degree of islet fibrosis. Finite mixture mathematical modeling for the joint probability distribution of seven islet parameters to represent islet numerical data variation provided an automatic procedure for islet category allocations as normal or abnormal. Allocations for obese ZDF controls and rosiglitazone-treated animals were significantly different, with no significant difference between the latter and lean ZDF controls, indicative of differences within islet populations of individual animals, between lean and obese rat strains and following drug treatment. Islet morphology showed clear association with mathematical characterization. Information on islet morphology obtained by histopathological assessment of single pancreatic tissue sections was confirmed by this method showing drug-induced retardation of islet of Langerhans degeneration.

A number of novel urinary biomarkers have been identified and partially qualified for use as markers for renal injury in rats. We use two novel multiplex assays to quantify biomarker concentration in multiple urine collections made prior to and following administration of cisplatin, a common nephrotoxicant, to rats. We investigate the correlation of the magnitude of biomarker changes with the severity of histopathological observations and explore the relationship of these to both dose and sex. The novel biomarkers evaluated are urinary albumin, alpha glutathione s-transferase (α-GST), glutathione S-transferase-yb1 (GSTYb1), lipocalin-2, kidney injury molecule-1 (KIM-1), osteopontin, and renal papillary antigen 1 (RPA-1) and plasma cystatin C, alongside the traditional biomarkers of plasma urea, creatinine, and urinary n-acetyl-beta-d-glucosaminidase (NAG), total protein, and glucose. We show for all time points, and for almost all doses, that male rats consistently had either more severely graded or a higher incidence of histologically observed lesions than females; that changes in urinary glucose, total urinary protein, NAG, and the novel urinary biomarkers albumin, osteopontin, and KIM-1 are clearly temporally associated; and that changes are related to the severity of injury. We also found that receiver operating characteristic curve analysis and area under the curve are significantly higher than urea or creatinine for all new biomarkers except aGST, GSTYb1, cystatin c, and total protein in both sexes.

The distribution, metabolism, excretion and hepatic effects of diclofenac were investigated following a single oral dose of 10 mg/kg to wild type and hepatic reductase null (HRN) mice. For the HRN strain the bulk of the [(14)C]-diclofenac-related material was excreted in the urine/aqueous cagewash within 12 h of administration (~82%) with only small amounts eliminated via the faeces (~2% in 24 h). Wild type mice excreted the radiolabel more slowly with ca. 52 and 15% of the dose recovered excreted in urine and faeces, respectively, by 24 h post dose. The metabolic profiles of the HRN mice were dominated by acyl conjugation to either taurine or glucuronic acid. Wild type mice produced relatively small amounts of the acyl glucuronide. Whole Body Autoradiography (WBA) of mice sacrificed at 24 h post dose indicated increased retention of radioactivity in the livers of HRN mice compared to wild type mice. Covalent binding studies showed no differences between the two strains. Metabolism of diclofenac in HRN mice involved mainly acyl glucuronide formation and taurine amide conjugation. This mouse model may find utility in understanding the impact of reactive metabolite formation via routes that involve the production of acyl-CoA or acyl glucuronides of acidic drugs.

Diabetic nephropathy (DN) is a major cause of end-stage renal disease. Yet the pathogenic mechanisms underlying the development of DN are not fully defined, partially due to lack of suitable models that mimic the complex pathogenesis of renal disease in diabetic patients. In this study, we describe early and late renal manifestations of DN and renal responses to long-term treatments with rosiglitazone or high-dose enalapril in ZSF1 rats, a model of metabolic syndrome, diabetes, and chronic renal disease. At 8 weeks of age, obese ZSF1 rats developed metabolic syndrome and diabetes (hyperglycemia, glucosuria, hyperlipidemia, and hypertension) and early signs of renal disease (proteinuria, glomerular collagen IV deposition, tubulointerstitial inflammation, and renal hypertrophy). By 32 weeks of age, animals developed renal histopathology consistent with DN, including mesangial expansion, glomerulosclerosis, tubulointerstitial inflammation and fibrosis, tubular dilation and atrophy, and arteriolar thickening. Rosiglitazone markedly increased body weight but reduced food intake, improved glucose control, and attenuated hyperlipidemia and liver and kidney injury. In contrast, rosiglitazone markedly increased cardiac hypertrophy via a blood pressure-independent mechanism. High-dose enalapril did not improve glucose homeostasis, but normalized blood pressure, and nearly prevented diabetic renal injury. The ZSF1 model thus detects the clinical observations seen with rosiglitazone and enalapril in terms of primary and secondary endpoints of cardiac and renal effects. This and previous reports indicate that the obese ZSF1 rat meets currently accepted criteria for progressive experimental diabetic renal disease in rodents, suggesting that this may be the best available rat model for simulation of human DN.

Dopaminergic agents are commonly used and effective treatments for restless legs syndrome (RLS), a disabling sensorimotor disorder. Less known are some of the potentially disabling side effects of these treatments, particularly iatrogenic gambling addiction, as is described here. Here the authors present a 62-year-old man, with a 20-year history of RLS, who developed gambling addiction while on dopaminergic treatment. He was not forewarned of this side effect, nor was he ever screened for gambling behaviours prior to or during treatment. Eight months after discontinuation of dopaminergic treatment and after 10 sessions of cognitive-behavioural therapy for gambling addiction, his gambling behaviours have partially resolved. To our knowledge, this is the first ever first person account of this condition. To prevent the devastating consequences of gambling addiction or to minimise its impact by early intervention, the authors call for clinicians involved in treatment of RLS to follow these simple measures: screen patients for gambling behaviours prior to the onset and during dopaminergic treatment; forewarn patients of this potential side effect; and if patients screen positive, refer them to specialist gambling treatment services, in addition to making necessary changes to their medication regime.

Introduction: Population demographics and disease epidemiology is resulting in more elderly patients presenting with regional metastases from cutaneous malignancy of the head and neck region. Surgery remains the most appropriate primary treatment option., Patients and Methods: We analysed consecutive patients aged 80 and over who developed regional metastases from cutaneous cancers of head and neck and underwent a neck dissection over a two-and-a-half-year period. Data were obtained from the cancer database and patients' notes. A Kaplan-Meier survival graph was constructed., Results: Our study demonstrated a low postoperative morbidity but one patient died from medical complications with in the first 30 days post surgery. The median survival time following surgery is nearly two years., Conclusions: We continue to advocate primary surgery for cutaneous metastatic malignancy from the head and neck area but patients need multidisciplinary team discussions, thorough assessment and counselling.

Aims: To investigate whether glucose lowering with the selective sodium glucose transporter 2 (SGLT2) inhibitor dapagliflozin would prevent or reduce the decline of pancreatic function and disruption of normal islet morphology., Methods: Female Zucker diabetic fatty (ZDF) rats, 7-8 weeks old, were placed on high-fat diet. Dapagliflozin (1 mg/kg/day, p.o.) was administered for ∼33 days either from initiation of high-fat diet or when rats were moderately hyperglycaemic. Insulin sensitivity and pancreatic function were evaluated using a hyperglycaemic clamp in anaesthetized animals (n = 5-6); β-cell function was quantified using the disposition index (DI) to account for insulin resistance compensation. Pancreata from a matched subgroup (n = 7-8) were fixed and β-cell mass and islet morphology investigated using immunohistochemical methods., Results: Dapagliflozin, administered from initiation of high-fat feeding, reduced the development of hyperglycaemia; after 24 days, blood glucose was 8.6 ± 0.5 vs. 13.3 ± 1.3 mmol/l (p < 0.005 vs. vehicle) and glycated haemoglobin 3.6 ± 0.1 vs. 4.8 ± 0.26% (p < 0.003 vs. vehicle). Dapagliflozin improved insulin sensitivity index: 0.08 ± 0.01 vs. 0.02 ± 0.01 in obese controls (p < 0.03). DI was improved to the level of lean control rats (dapagliflozin 0.29 ± 0.04; obese control 0.15 ± 0.01; lean 0.28 ± 0.01). In dapagliflozin-treated rats, β-cell mass was less variable and significant improvement in islet morphology was observed compared to vehicle-treated rats, although there was no change in mean β-cell mass with dapagliflozin. Results were similar when dapagliflozin treatment was initiated when animals were already moderately hyperglycaemic., Conclusion: Sustained glucose lowering with dapagliflozin in this model of type 2 diabetes prevented the continued decline in functional adaptation of pancreatic β-cells., (© 2010 AstraZeneca UK Ltd.)