CIB1 deficiency results in impaired thrombosis: the potential role of CIB1 in outside-in signaling through integrin alpha IIb beta 3

Agonist-induced inside-out signaling activates platelet integrin alpha(IIb)beta(3), rendering it to bind plasma fibrinogen (Fg). Fg binding induces outside-in signaling that culminates in platelet aggregation, leading to physiological hemostasis and pathological thrombosis. How outside-in signaling through alpha(IIb)beta(3) regulates hemostasis and thrombosis is not well understood. We have previously shown that CIB1 is involved in regulating alpha(IIb)beta(3) function.

OBJECTIVE

To determine the in vivo role of CIB1 in the process of hemostasis and thrombosis.

METHODS AND RESULTS

Genetic ablation of Cib1 significantly increased mouse tail bleeding time. Greater than 50% of the Cib1 null mice showed a rebleeding phenotype. Time taken for complete occlusion of carotid artery upon 10% FeCl(3)-induced injury was significantly delayed in the absence of Cib1. This was also associated with unstable thrombus formation. The inside-out signaling appears normal as ADP-, collagen- and PAR4 peptide-induced aggregation and fibrinogen binding was unaffected. The absence of Cib1 also affected the ability of platelets to spread on immobilized Fg, but not filopodia formation. Spreading could be restored in Cib1 null platelets by the addition of exogenous ADP. Outside-in signaling-dependent tyrosine phosphorylation of the integrin beta(3) subunit was significantly reduced in the absence of Cib1 as determined by Western blot analysis.

CONCLUSION

Using gene knockout mice, we show for the first time that lack of Cib1 results in impaired thrombosis. CIB1 regulates these processes by affecting platelet spreading, but not platelet filopodia formation. These in vivo and in vitro results clearly show that CIB1 is a key regulator of thrombosis.

Radiographic anatomy of the rabbit skull, with particular reference to the tympanic bulla and temporomandibular joint. Part 2: Ventral and dorsal rotational angles

This is the second part of a two-part study to document rabbit skull radiographic anatomy with particular reference to the temporomandibular joint (TMJ) and tympanic bulla (TB), and identify views that allowed their optimal visualisation. Equipment was used that allowed repeatable positioning of skulls at known rotational angles in ventral (rostrocaudal to ventrodorsal) with the mouth closed and open, and dorsal (rostrocaudal to dorsoventral position) directions. The views were repeated with lead markers attached to anatomical features and cadaver heads. The TBs were visible between 40° and 90° from rostrocaudal in both directions, but opening the mouth did not improve visualisation. The TMJs were visible until 40° in a ventral direction, but only 20° in a dorsal one. Opening the mouth slightly altered the regions of the joint being skylined, but did not otherwise enhance imaging of this region.

Intermittent marijuana use is associated with improved retention in naltrexone treatment for opiate-dependence

Naltrexone is a theoretically promising alternative to agonist substitution treatment for opioid dependence, but its effectiveness has been severely limited by poor adherence. This study examined, in an independent sample, a previously observed association between moderate cannabis use and improved retention in naltrexone treatment. Opioid dependent patients (N = 63), admitted for inpatient detoxification and induction onto oral naltrexone, and randomized into a six-month trial of intensive behavioral therapy (Behavioral Naltrexone Therapy) versus a control behavioral therapy (Compliance Enhancement), were classified into three levels of cannabis use during treatment based on biweekly urine toxicology: abstinent (0% cannabis positive urine samples); intermittent use (1% to 79% cannabis positive samples); and consistent use (80% or greater cannabis positive samples). Intermittent cannabis users showed superior retention in naltrexone treatment (median days retained = 133; mean = 112.8, SE = 17.5), compared to abstinent (median = 35; mean = 47.3, SE = 9.2) or consistent users (median = 35; mean = 68.3, SE = 14.1) (log rank = 12.2, df = 2, p = .002). The effect remained significant in a Cox model after adjustment for baseline level of heroin use and during treatment level of cocaine use. Intermittent cannabis use was also associated with greater adherence to naltrexone pill-taking. Treatment interacted with cannabis use level, such that intensive behavioral therapy appeared to moderate the adverse prognosis in the consistent cannabis use group. The association between moderate cannabis use and improved retention on naltrexone treatment was replicated. Experimental studies are needed to directly test the hypothesis that cannabinoid agonists exert a beneficial pharmacological effect on naltrexone maintenance and to understand the mechanism.

Differential stimulation of monocytic cells results in distinct populations of microparticles

BACKGROUND

Microparticles (MPs), small vesicles shed from stimulated cells, permit cross-talk between cells within a particular environment. Their composition is thought to reflect their cell of origin, and differs according to whether they are produced by stimulation or by apoptosis. Whether MP properties vary according to stimulus is not yet known.

METHODS

We studied the characteristics of MPs produced from monocytic THP-1 cells upon stimulation with lipopolysaccharide or a soluble P-selectin chimera, using proteomics, flow cytometry, western blotting, and electron microscopy.

RESULTS

Utilizing a novel criterion of calcein-AM staining to define MPs, we found that MP populations were similar with respect to size, presence and organization of cytoskeleton, and expression of certain antigens. The MPs shared the same level of procoagulant activity. We found that MPs also have distinct characteristics, depending on stimuli. These include differences in phosphatidylserine expression and expression of proteins from specific subcellular locations such as the mitochondria, and of unique antigens such as leukocyte-associated immunoglobin-like-receptor (LAIR)-1, which was found only upon stimulation with the soluble P-selectin chimera.

CONCLUSION

We found that the properties of MPs depend on the stimulus that produced them. This supports the concept that monocytic MPs differentially modulate thrombosis, inflammation and immune regulation according to stimulus.

Clinical and pathological findings associated with congenital hypovitaminosis A in extensively grazed beef cattle

OBJECTIVE

To determine the cause of exceptionally high mortality (41.4%) in perinatal calves on a beef cattle property 50 km south-west of Julia Creek in north-western Queensland.

DESIGN

Investigations were based on clinical assessment of affected calves and laboratory analysis of pre- and postmortem specimens taken from 12 calves aged from 6 to 36 h of age.

METHODS

Associations between gross and histopathological findings and biochemical analyses conducted on serum and tissue samples were examined in relation to clinical observations.

RESULTS

Clinical signs varied, but commonly included mild to severe ataxia, difficulty finding a teat and sucking, blindness (partial or complete, as judged by avoidance of obstacles) and depression with prominent drooping of the head. Gross and histopathological findings included herniation of the cerebellar vermis through the foramen magnum, squamous metaplasia of interlobular ducts in the parotid salivary glands and Wallerian degeneration of the optic nerves. Biochemical analysis of serum and liver samples available from four of the calves revealed low or undetectable levels of both vitamin A and vitamin E.

CONCLUSION

Although vitamin E is known to have a sparing effect on vitamin A, the role (if any) played by deficiency of this vitamin was uncertain. The combination of clinical signs, postmortem findings, histopathological features and biochemical findings indicate that gestational vitamin A deficiency was highly likely to have been an important contributor to perinatal calf mortalities in this herd.

The stability of the reactive oxygen metabolites (d-ROMs) and biological antioxidant potential (BAP) tests on stored horse blood

Increasing interest in the role of oxidative stress (OS) in equine medicine has highlighted the need to develop reliable methods to quantify it. In this study we describe the effect of refrigeration (at 4 degrees C) on the stability of the reactive oxygen metabolites (d-ROMs) and biological antioxidant potential (BAP) tests carried out on 15 healthy horses. Blood samples, collected from the jugular vein, were immediately placed on ice and analysed using both the d-ROMs and BAP tests. Samples were also refrigerated at 4 degrees C and tested after 3, 7 and 24 h. The average results were similar for up to 24 h and minimal variations were found for each horse. The findings suggest that refrigeration is suitable for preserving equine blood samples for these assays and this approach will provide veterinarians with a technically simple, reliable test to measure OS under field conditions.

Spinal deformation in commercially cultured Atlantic salmon, Salmo salar L.: a clinical and radiological study

A clinical and radiographic study was carried out on 2016 randomly selected Atlantic salmon parr from six farms, which weighed between 55 and 100 g. In addition, 86 fish from six marine farms were similarly studied. Radiographically detectable vertebral lesions were found in 3.8-8.8% of the parr. The changes ranged from a single vertebra showing features, such as demineralization, increased density and slight loss of structure, to fish with multiple vertebrae affected by collapse, fusion and change in intervertebral space that could give rise to lordosis or kyphosis or abnormal vertebrae at several locations. The predominant location was the vertebral region V21-27, and rarely V44 caudad. The radiographic changes in seawater salmon mirrored those found in parr, but vertebrae V35 caudad were more frequently involved. Very few parr were found to have abnormal vertebrae in the peduncle area which suggests that the development of lesions at this location occurs de novo in the seawater phase, given that 'stumpy' fish are most frequent reported deformity at slaughter. It was concluded that minor vertebral change could be detected radiographically in many parr with no observable effect on external morphology. Whether such minor radiographic alteration would proceed to observable morphological change at slaughter weight is open to question.

The aetiology of spinal deformity in Atlantic salmon, Salmo salar L.: influence of genetic factors on the frequency and severity in freshwater stages

A radiographic study was carried out on 2-year groups of pre-smolt parr to detect the comparative frequency of vertebral change in a range of defined pedigreed families of high growth rate of Atlantic salmon, Salmo salar L., reared under identical conditions. The observed frequency of deformity was related to the observed deformity level in the seawater parental generation, and to a potentially uncontrolled environmental determinant, i.e. stripping date. High and low parental deformity groups of families were found to produce offspring that had very similar levels of radiographically detectable spinal deformities in the pre-smolt parr, suggesting no genetic link. With regard to stripping date, the overall incidence was nearly half that seen in the preceding year (8.7% cf 16.6%). However, a non-significant trend to fewer radiographic spinal deformities was seen in the later stripping period.

The aetiology of spinal deformity in Atlantic salmon, Salmo salar L.: influence of different commercial diets on the incidence and severity of the preclinical condition in salmon parr under two contrasting husbandry regimes

A large-scale trial of the effect of different commercial diets on the incidence of preclinical spinal deformation, as assessed by radiography, and the influence of two contrasting rearing systems was carried out. Two sets of three populations of Atlantic salmon, each of 20 000 first feeding fry of identical hatchery origin, created from equal numbers of eggs from 15 different families, were reared under commercial conditions on two different farms. Three commercial (closed formula) extruded fish meal-based diets were used in this study (diets A, B & C). Each diet was fed to one population of 20 000 fish at each site. Fish were fed a percentage of their body weight per day, with feeding rates set at commercial levels, based on water temperature, day length and fish biomass. Additional hand feeding was used to ensure satiation in all tanks. Fish in each tank were bulk-weighed and counted at the beginning and at 2-week intervals throughout the study. The fish were grown for 30 weeks. In addition, phosphorus (P) digestibility was evaluated by in-feed absorption testing in rainbow trout. The morphology of the radiographic lesions conformed to those described previously. Statistical analysis using multivariate regression analysis showed that date of sampling, site and diet were all statistically significant (P < 0.001) on univariable analysis. Farm A had significantly more affected fish than farm B (P < 0.001), which may have been attributable to variation in dissolved oxygen levels. The available dietary P levels were low in each diet. The number of fish affected in the group of fish being fed diet B was significantly lower than in the groups being fed diets A or C (P < 0.001). It appears most likely that the occurrence of preclinical radiographically apparent defects in parr which are believed to lead to the condition known as 'spinal deformity' is predominantly caused by a deficiency of available dietary P in first-feeding fry. The availability of dietary P may also vary considerably between diets formulated using different ingredients. Phytate-P associated with plant ingredients may affect the availability of P as well as other essential dietary nutrients. Additionally, diets for the production of salmonids in fresh water are currently formulated to keep P effluent to a minimum compatible with healthy spinal development. These various factors combine to make it crucial that small Atlantic salmon, especially first-feeding fry, are provided with carefully formulated diets fortified to an adequate level with a high quality source of available P.

Bisphosphonate-induced osteonecrosis of the jaw: Risk factors and diagnostic utility of bone scans

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Background: Osteonecrosis of the jaw (ONJ) is a serious long-term effect of intravenous bisphosphonates. We report characteristics of patients with ONJ at Roswell Park Cancer Institute (RPCI) and utility of bone scans in its diagnosis. Methods: Patients were identified using RPCI database. ONJ diagnosed was staged using the system used for jaw osteoradionecrosis (Schwartz et al, Am J Clin Oncol, 2002). Controls included patients receiving bisphosphonates between July 2002 and 2006. Routine whole body bone scans were reviewed for jaw uptake. Statistical analysis was done using SAS 9.1. Results: Three hundred and fifty-four patients received intravenous bisphosphonates between July 2002 and 2006. Twenty-four (7%) were diagnosed with ONJ. Among patients with ONJ, fifteen (63%) had breast cancer, eight (33%) had multiple myeloma and one (4%) had lung cancer. Mean age was 56.8 years. (SD= 9.1) Thirteen patients (54%) had tobacco use, five (21%) had diabetes, nine (37.5%) had hypertension and twenty-three patients (96%) received chemotherapy. Five patients (21%) had caries, three (12.5%) had dental surgery, nine (37.5%) had periodontal disease, thirteen (54%) had extractions and one (4%) had prior dental trauma. Twenty-two patients (92%) presented with pain. Twelve patients (50%) had ONJ Stage 1, eight (33%) Stage 2 and four (17%) Stage 3. Median duration of exposure to bisphosphonates was 39 months. The difference between the average number of infusions in the ONJ group (11.2, CI: 11.3, 20.3) and control group (7.2, CI: 6.2, 8.2) was found to be significant (p<0.0009). Three patients (12.5%) had progressive ONJ. Thirteen patients with ONJ had bone scans and twelve (92%) showed jaw uptake. Among controls, one hundred and eighty-three had bone scans and one hundred and twenty-eight (70%) showed jaw uptake. This difference was not significant. (p=0.114, two-tailed Fisher's exact test). Conclusions: In our study, chemotherapy, smoking, prior dental extractions and the number of bisphosphonate infusions appear to be risk factors for ONJ. It has been recently reported (Chiandussi et al., Dentomaxillofacial Radiol. 2006) that bone scans can be used as a screening tool for ONJ, however, in our series jaw uptake on bone scan was not a reliable predictor for the development of ONJ.

No significant financial relationships to disclose.

The VHL tumor suppressor inhibits expression of the IGF1R and its loss induces IGF1R upregulation in human clear cell renal carcinoma

Clear cell renal cell cancer (CC-RCC) is a highly chemoresistant tumor characterized by frequent inactivation of the von Hippel-Lindau (VHL) gene. The prognosis is reportedly worse in patients whose tumors express immunoreactive type I insulin-like growth factor receptor (IGF1R), a key mediator of tumor cell survival. We aimed to investigate how IGF1R expression is regulated, and found that IGF1R protein levels were unaffected by hypoxia, but were higher in CC-RCC cells harboring mutant inactive VHL than in isogenic cells expressing wild-type (WT) VHL. IGF1R mRNA and promoter activities were significantly lower in CC-RCC cells expressing WT VHL, consistent with a transcriptional effect. In Sp1-null Drosophila Schneider cells, IGF1R promoter activity was dependent on exogenous Sp1, and was suppressed by full-length VHL protein (pVHL) but only partially by truncated VHL lacking the Sp1-binding motif. pVHL also reduced the stability of IGF1R mRNA via sequestration of HuR protein. Finally, IGF1R mRNA levels were significantly higher in CC-RCC biopsies than benign kidney, confirming the clinical relevance of these findings. Thus, we have identified a new hypoxia-independent role for VHL in suppressing IGF1R transcription and mRNA stability. VHL inactivation leads to IGF1R upregulation, contributing to renal tumorigenesis and potentially also to chemoresistance.

Anatomy and ultrasonographic appearance of the tympanic bulla and associated structures in the rabbit

Otitis media is a relatively common condition in the rabbit although it can be difficult to evaluate clinically. Diagnostic imaging of the rabbit has traditionally involved radiography and there are few reports regarding the use of ultrasound. The aim of this study was to determine if the tympanic bulla (TB) and associated structures could be evaluated in the rabbit using currently available ultrasound equipment. The normal anatomy of the region was established using gross dissection and emascerated specimens and compared with the dog and cat. Ten New Zealand white rabbit cadavers were examined using two ultrasound machines and four transducers from a variety of locations. A 12 MHz linear transducer was found to be most appropriate. From a lateral approach the external ear canal could be visualized to the level of the external acoustic meatus while the TB itself could only be visualized from a ventral approach. The jugular and mastoid processes in the rabbit are very prominent and interfered with imaging of the TB from all approaches. Water-soluble lubricant introduced into the TB could be identified through the ventral bone wall of the TB and allowed the lumen and far wall to be visualised. Further work is required to determine whether ultrasound examination of the TB can be performed in live rabbits and to evaluate its benefits in the evaluation of clinical cases of otitis media.

Comparison of ultrasonography, radiography and a single computed tomography slice for fluid identification within the feline tympanic bulla

Evaluation of the tympanic bulla (TB) in cases of acute feline otitis media can be a diagnostic challenge, although a feature often associated with this condition is the accumulation of fluid or material within the middle ear cavity. A technique is reported allowing optimum imaging of the feline TB using ultrasound (US) and recording of the appearance of gas and fluid-filled TB. A random number of bullae in 42 feline cadavers were filled with lubricant and rostroventral-caudodorsal oblique radiographs, single slice computed tomography (CT) images and US images were created and interpreted by blinded operators. The content (fluid or gas) of each TB was determined using each technique and the cadavers were then frozen and sectioned for confirmation. CT remained the most accurate diagnostic method, but US produced better results than radiology. Given the advantages of US over other imaging techniques, these results suggest that further work is warranted to determine applications of this modality in the evaluation of clinical cases of feline otitis media.

Assessment of middle ear disease in the dog: a comparison of diagnostic imaging modalities

OBJECTIVES

To compare radiography and ultrasound for the assessment of the tympanic bulla against computed tomography results.

METHODS

Thirty-one dogs had dorsoventral, left and right lateral oblique and rostrocaudal open mouth radiographs compared with ultrasound images and computed tomography scans of the tympanic bullae.

RESULTS

Radiography was superior to ultrasonography for the evaluation of the middle ear. However, computed tomography assessment was best predicted by a combination of radiographic and ultrasonographic findings.

CLINICAL SIGNIFICANCE

A combination of radiography and ultrasound can provide a more accurate assessment of the bulla than either of them alone. Ultrasound may have a role in the evaluation of middle ear disease in the dog. Results are operator dependent and not reproducible with current recording techniques.

Ten-year trends in health-related quality of life after surgical and conventional treatment for severe obesity: the SOS intervention study

OBJECTIVE

To examine trends and effects of weight loss treatment on health-related quality of life (HRQL) in the severely obese over 10 years.

DESIGN

Swedish obese subjects (SOS) intervention study is a controlled, longitudinal trial of the health effects of weight loss in the severely obese.

SUBJECTS

A total of 655 of 851 surgically treated and 621 of 852 conventionally treated obese men (body mass index, BMI>or=34) and women (BMI>or=38) who completed 10 years of the study.

MEASUREMENTS

HRQL was assessed before treatment and after 0.5, 1, 2, 3, 4, 6, 8 and 10 years.

RESULTS

HRQL change during the 10-year observation period largely followed phases of weight loss, weight regain and weight stability. Improvements and deteriorations in HRQL were associated with the magnitude of weight loss or regain, except regarding anxiety. Peak improvements in the surgical group were observed during the first year of weight loss, whereas the weight regain phase (mainly between 1- and 6-year follow-up) was accompanied by a gradual decline in HRQL. The period from 6- to 10-year follow-up was characterized by relatively stable observations in both weight and HRQL. At 10 years, net gains were noted in all HRQL domains compared to baseline. Comparisons of treatment effects on HRQL in the surgical vs conventional group after 10 years showed significantly better outcome in the surgical group on current health perceptions, social interaction, psychosocial functioning and depression, whereas no significant differences were found for overall mood and anxiety. Long-term results of the study suggest that a maintained weight loss of about 10% is sufficient for positive long-term effects on HRQL, a limit that was reached in about two-thirds of the surgically treated patients who completed 10 years of the study.

CONCLUSION

Long-lasting weight reduction in the severely obese has a general long-standing positive outcome on HRQL. Bariatric surgery is a favorable option for the treatment of severe obesity, resulting in long-term weight loss and HRQL improvements in a majority of patients. However, difficulties among some surgical patients to control and maintain weight loss over time should not be ignored. Future research should study if the long-term efficacy of bariatric surgery may be further enhanced by implementing lifestyle modification techniques in the postoperative management of patients.