Repeated evolution of camouflage in speciose desert rodents.

There are two main factors explaining variation among species and the evolution of characters along phylogeny: adaptive change, including phenotypic and genetic responses to selective pressures, and phylogenetic inertia, or the resemblance between species due to shared phylogenetic history. Phenotype-habitat colour match, a classic Darwinian example of the evolution of camouflage (crypsis), offers the opportunity to test the importance of historical versus ecological mechanisms in shaping phenotypes among phylogenetically closely related taxa. To assess it, we investigated fur (phenotypic data) and habitat (remote sensing data) colourations, along with phylogenetic information, in the species-rich Gerbillus genus. Overall, we found a strong phenotype-habitat match, once the phylogenetic signal is taken into account. We found that camouflage has been acquired and lost repeatedly in the course of the evolutionary history of Gerbillus. Our results suggest that fur colouration and its covariation with habitat is a relatively labile character in mammals, potentially responding quickly to selection. Relatively unconstrained and substantial genetic basis, as well as structural and functional independence from other fitness traits of mammalian colouration might be responsible for that observation.

Imaging of Complications After Limb Prostheses Implantation in Children with Bone Tumors.

BACKGROUND: Tumors of the developmental age are an important problem in clinical practice. Primary bone tumors constitute 1-1.5% of all tumors, and 7% of all tumors diagnosed in the developmental age. The aim of the study was to assess the capabilities of imaging methods in diagnosing complications of limb endoprostheses in children with osteoarticular tumors. MATERIAL/METHODS: We included 155 patients with limb endoprostheses, aged 7-26 years. There were 113 patients with knee prostheses, 1 patient with bilateral knee prostheses, 16 patients with shoulder prostheses, 14 patients with hip prostheses, 11 patients with hip and knee prostheses, and 1 patient with a femoral prosthesis. All patients underwent plain radiography and an ultrasound study. RESULTS: Complications were found in 50 patients (32% of all patients). The following complications were seen - inflammatory changes in soft tissues and bones (12 patients, 7.7%), stump fractures (11 patients, 7%), lack of elongation effect or shortening of the prosthesis (7 patients, 4.5%), prosthesis fractures (4 patients, 2.5%), crural fractures (4 patients, 2.5%), loosening of the prosthesis (3 patients, 1.9%), joint dislocation (2 patients, 1.3%), stump and prosthesis fracture (1 patient, 0.6%) and local recurrence (6 patients, 3.9%). Prostheses were exchanged for the following reasons - fractures (5 patients, 3.2%), inflammation (2 patients with 3 exchanges, 1.9%). Local recurrence and inflammation were confirmed by a biopsy. CONCLUSIONS: Radiography and ultrasonography are of crucial importance in monitoring patients after implantation of limb endoprostheses. The findings did not require confirmation in additional studies: CT and MRI. Suspicion of local recurrence and inflammation required a biopsy confirmation.

Circle of Willis abnormalities in children with neurofibromatosis type 1.

BACKGROUND AND PURPOSE: The aim of the study was to assess anatomical variants and abnormalities in cerebral arteries on magnetic resonance angiography in 67 children with neurofibromatosis type 1 (NF1). MATERIALS AND METHODS: The study included 67 children aged 9 months to 18 years (mean 6.6 years). Control group comprised 90 children aged 2-18 years (mean: 11.8 years). All patients were examined at 1.5T scanner. RESULTS: We found cerebral arteriopathy (moyamoya disease) in one child (1.5%) in the study group. No aneurysms were found. Twenty-nine NF1 children (43.3%) had arterial anatomical variants. In 13 of them, more than one variant was diagnosed (44.8% of group with variants, 19.4% of study group). In control group, 19 children (21.1%) had variants, including four children with more than one variant (21% of group with variants, 4.4% of control group). Arterial variants were more common in NF1 patients compared with control group (p=0.026, binomial test for two proportions). Percentage of multiple variants was higher in study group than in control group, but this difference was not significant. Variants were more frequent on left side than on the right one (significant difference in control group; p=0.022, McNemara test). In study group, the number of left-sided anomalies (25) was similar to that of right-sided ones (22). There was no correlation between gender and variants, unidentified bright objects and variants or between optic gliomas and variants. CONCLUSIONS: Occurrence of arterial variants in NF1 patients was twofold higher than in control group. Multiple variants were more frequent in the study group although the difference did not reach statistical significance. Features of cerebral arteriopathy were found in one child with NF1.

[Sonography of small bowel, colon and appendix in children with cystic fibrosis]. / Ocena ultrasonograficzna jelita cienkiego, grubego i wyrostka robaczkowego u pacjentów z mukowiscydoza.

AIM: To assess the utility of sonographic examination in estimation of the incidence and character of pathological changes in different parts of the intestine and other abdominal organs in children with cystic fibrosis (CF). MATERIAL AND METHOD: The study group consisted of 182 children (94 girls, 88 boys), aged from 2 months up to 22 yrs, with diagnosed cystic fibrosis or its suspicion, confirmed later. The control group consisted of 20 children with mean age 8 yrs. Sonography was performed with Philips equipment: 4000 HDI and iU 22 using convex, microconvex and linear probes. 329 examinations were performed in 182 children in 2.5 years, 109 underwent second US and 38 patients were examined for the third time. RESULTS: In children with CF, changes in the intestines were observed in 108 patients (59.3%), in the colon in 97 patients (53.3%), and in the small intestine in 49 patients (26.9%). In the control group the wall thickness of large intestine did not surpass 1.6 mm, of small intestine--1.4 mm. In the tested group the maximum thickness of large intestine wall was 7 mm and of small intestine--4.3 mm. Layer structure of the ileum wall was found in 46 children (25%), enlarged appendix in 21 patients (11.6%). Enlarged mesenteric lymph nodes were observed in 84 pts (46%). Hyperaemia of the bowel wall was not observed on Power Doppler examination. In 71 patients (39%) changes in the structure of the liver were observed (cirrhosis, steatosis, enlargement) and in 114 (62.6%) there were changes in the pancreas. CONCLUSIONS: Sonographic examination in patients with cystic fibrosis revealed a high frequency of intestinal changes which confirms the need of including this examination in the annual follow-up of children with CF. In cases of unidentified CF, abdominal sonography leads to the diagnosis.

Development of a VX2 pancreatic cancer model in rabbits: a pilot study.

PURPOSE: An animal model of pancreatic cancer that is large enough to permit imaging and catheterization would be desirable for interventional radiologists to develop novel therapies for pancreatic cancer. The purpose of this study was to test the hypothesis that the VX2 rabbit model of pancreatic cancer could be developed as a suitable platform to test future interventional therapies. MATERIALS AND METHODS: The authors implanted and grew three pancreatic VX2 tumors per rabbit in six rabbits. Magnetic resonance (MR) imaging was performed at 2 weeks to confirm tumor growth. At 3 weeks, the authors selectively catheterized the gastroduodenal artery under guidance of x-ray digital subtraction angiography (DSA). T2-weighted anatomic imaging, diffusion-weighted MR imaging, and transcatheter intraarterial perfusion (TRIP) MR imaging were then performed. After imaging, tumors were confirmed at necropsy and histopathologically. Tumor sizes at 2 and 3 weeks were compared with a paired t test (P = .05). RESULTS: VX2 pancreatic tumors were grown in all six rabbits. The difference between tumor sizes at 2 and 3 weeks (1.29 cm +/- 0.39 vs 1.91 cm +/- 0.50, respectively) was significant (P < .001). All tumors were confirmed to be located within pancreatic tissue via histopathologic analysis. DSA and TRIP MR imaging were successful in five rabbits. Diffusion-weighted and anatomic MR imaging were successful in all six rabbits. CONCLUSIONS: The VX2 rabbit model of pancreatic cancer is feasible, as verified by imaging and pathologic correlation, and may be a suitable platform to test future interventional therapies.

Comparison of hypoxia-inducible factor-1alpha expression before and after transcatheter arterial embolization in rabbit VX2 liver tumors.

PURPOSE: To test the hypothesis that transcatheter arterial embolization (TAE) induces expression of hypoxia-inducible factor-1alpha (HIF-1alpha) within the same rabbit VX2 liver tumor. MATERIALS AND METHODS: Seven VX2 tumors were grown in the livers of five New Zealand white rabbits. Ultrasonography-guided biopsy was performed before and 10 minutes after TAE in all tumors. Pre- and post-TAE tumor biopsy specimens along with post-TAE whole liver tumor sections were stained with HIF-1alpha antibody and analyzed for percentage of HIF-1alpha-positive nuclei by using a spectral unmixing system mounted on a high-powered microscope. Statistical data comparisons were performed with the Wilcoxon signed-rank test (alpha = 0.05). RESULTS: TAE of liver tumors resulted in a statistically significant increase in the mean percentage of HIF-1alpha expression. The mean percentage of HIF-1alpha-positive stained nuclei increased from 23% +/- 3.5 in pre-TAE biopsy specimens to 41% +/- 8.7 in post-TAE biopsy specimens (P < .02). The increase was even more significant when the mean percentage of HIF-1alpha-positive stained nuclei from the same pre-TAE biopsy specimens was compared with sections from post-TAE whole tumor specimens (60% +/- 8.9, P < .02). CONCLUSIONS: The results of this study revealed that hypoxia caused by TAE of VX2 liver tumors activates HIF-1alpha, a transcription factor that in turn regulates other pro-angiogenic factors.

MR tracking of iron-labeled glass radioembolization microspheres during transcatheter delivery to rabbit VX2 liver tumors: feasibility study.

PURPOSE: To prospectively test the hypothesis that iron labeling of radioembolization microspheres permits their visualization by using magnetic resonance (MR) imaging for in vivo tracking during transcatheter delivery to liver tumors. MATERIALS AND METHODS: All experiments were approved by the Institutional Animal Care and Use Committee. Phantom studies were performed to quantify microsphere relaxivity and volume susceptibility properties and compare image contrast patterns resulting from aggregate deposition of unlabeled and iron-labeled microspheres. In seven rabbits in which nine VX2 liver tumors were implanted, T2*-weighted gradient-echo (GRE) MR images with negative image contrast (NC), white-marker (WM) GRE images with positive image contrast (PC), and on-resonance water-suppression turbo spin-echo (SE) images with PC were obtained before and after catheter-directed administration of microspheres into the hepatic artery. During each injection, serial GRE acquisitions were performed for real-time visualization of microsphere delivery. Contrast-to-noise ratios (CNRs) were measured between regions of microsphere accumulation and regions of normal liver parenchyma that demonstrated no apparent microsphere accumulation. Pre- and postinjection CNR measurements at identical spatial positions were compared by using paired t test (alpha = .05). RESULTS: Conventional microspheres did not produce detectable image contrast in phantoms. Iron-labeled microspheres produced susceptibility-induced dipole patterns with spatial extent of image contrast increasing with increasing microsphere dose. Real-time image series depicted both preferential delivery to tumor tissues and nontargeted delivery to adjacent organs. T2*-weighted GRE, WM GRE, and on-resonance water-suppression turbo SE each permitted in vivo visualization of the microsphere deposition, with postinjection CNR values (mean, 14.29 +/- 3.98 [standard deviation], 1.87 +/- 0.93, and 19.30 +/- 8.72, respectively) significantly greater than corresponding preinjection CNR values (mean, 2.02 +/- 4.65, 0.02 +/- 0.27, 0.85 +/- 2.65, respectively) (P < .05). CONCLUSION: Microsphere tracking during radioembolization may permit real-time verification of delivery and detection of extrahepatic shunting.

Four-dimensional transcatheter intraarterial perfusion (TRIP)-MRI for monitoring liver tumor embolization in VX2 rabbits.

Transcatheter intraarterial perfusion (TRIP)-MRI is an intraprocedural technique to iteratively monitor liver tumor perfusion changes during transcatheter arterial embolization (TAE) and chemoembolization (TACE). However, previous TRIP-MRI approaches using two-dimensional (2D) T(1)-weighted saturation-recovery gradient-recalled echo (GRE) sequences provided only limited spatial coverage and limited capacity for accurate perfusion quantification. In this preclinical study, a quantitative 4D TRIP-MRI technique (serial iterative 3D volumetric perfusion imaging) with rigorous radiofrequency (RF) B(1) field calibration and dynamic tissue longitudinal relaxation rate R(1) measurement is presented for monitoring intraprocedural liver tumor perfusion during TAE. 4D TRIP-MRI and TAE were performed in five rabbits with eight VX2 liver tumors (N = 8). After B(1) calibrated baseline and dynamic R(1) quantification, subsequent tissue contrast agent concentration time curves were derived. A single-input flow-limited pharmacokinetic model and peak gradient method were applied for perfusion analysis. The perfusion Frho reduced significantly from pre-TAE 0.477 (95% confidence interval [CI]: 0.384-0.570) to post-TAE 0.131 (95% CI: 0.080-0.183 ml/min/ml, P < 0.001).

Gadolinium-conjugated TiO2-DNA oligonucleotide nanoconjugates show prolonged intracellular retention period and T1-weighted contrast enhancement in magnetic resonance images.

Nanoconjugates composed of titanium dioxide (TiO2) nanoparticles, DNA oligonucleotides, and a gadolinium (Gd) contrast agent were synthesized for use in magnetic resonance imaging. Transfection of cultured cancer cells with these nanoconjugates showed them to be superior to the free contrast agent of the same formulation with regard to intracellular accumulation, retention, and subcellular localization. Our results have shown that 48 hours after treatment, the concentration of Gd in nanoconjugate-treated cells was 1000-fold higher than in cells treated with contrast agent alone. Consequently, T1-weighted contrast enhancements were observed in cells treated with nanoconjugates but not in cells treated by the contrast agent alone. This type of nanoconjugate with increased retention time, Gd accumulation, and intracellular delivery may find its use in Gd neutron-capture cancer therapy.

Comparison of two different methods for inoculating VX2 tumors in rabbit livers and hind limbs.

PURPOSE: To compare two methods to (a) propagate VX2 cell strain in rabbit hind limbs and (b) inoculate liver parenchymal tumors in rabbits. MATERIALS AND METHODS: One hundred forty-two New Zealand white rabbits were used for this study (60 with hind limb tumor [donors] and 82 with liver tumors [recipients]). In the donor group, nine rabbits received frozen VX2 cell suspension and 51 were injected with freshly prepared VX2 cell suspension. In the recipient group, 32 rabbits were injected with VX2 tumor cells and 50 were implanted with a small tumor fragment in the liver parenchyma. Success rates in terms of tumor growth were compared by using chi(2) or Fisher exact tests, with alpha = .05. RESULTS: Hind limb and liver tumors were successfully grown in 48 of the 60 rabbits in the donor group (80%) and 57 of the 82 rabbits in the recipient group (70%). The success rate of growing hind limb tumors increased from 33% (three of nine rabbits) to 88% (45 of 51 rabbits) when fresh VX2 cells instead of frozen were injected percutaneously (P < .0011). Similarly, the success rate for VX2 liver tumors almost doubled from 47% (15 of 32 rabbits) to 84% (42 of 50 rabbits) when a tumor fragment instead of VX2 cell suspension was used (P < .00036). This also significantly reduced the frequency of metastasis (P < .005). CONCLUSIONS: The authors recommend (a) the use of fresh VX2 cell suspension for percutaneous injection in the hind limbs of rabbits to maintain the VX2 cell strain and (b) the surgical implantation of freshly harvested VX2 tumor fragment into the liver parenchyma to establish liver tumors.

Comparison of transcatheter intraarterial perfusion MR imaging and fluorescent microsphere perfusion measurements during transcatheter arterial embolization of rabbit liver tumors.

PURPOSE: Transcatheter intraarterial perfusion (TRIP) magnetic resonance (MR) imaging is clinically used in the interventional MR imaging setting to verify distribution of injected embolic or chemoembolic material during liver-directed transcatheter therapies and to monitor reductions in perfusion. The accuracy of this technique remains unknown. In the present study, rabbit VX2 liver tumors were used to test the hypothesis that TRIP MR imaging accurately measures changes in tumor perfusion during transcatheter arterial embolization (TAE), with injection of fluorescent microspheres used as the gold-standard technique. MATERIALS AND METHODS: Five New Zealand White rabbits were used for this study (two donor rabbits and three with VX2 liver tumors). In three rabbits with implanted VX2 liver tumors, catheters were superselectively placed under digital subtraction angiographic guidance into the left hepatic artery supplying the targeted tumor. Fluorescent microspheres were injected into each rabbit's left ventricle before and after TAE. TRIP MR images were obtained at baseline and after embolizations for all rabbits with intraarterial injections of 2.5% gadopentetate dimeglumine solution. Linear regression was used to compare relative reductions in tumor perfusion between TRIP MR imaging and fluorescent microspheres. Results were considered statistically significant at a P value less than .05. RESULTS: There was good correlation between TRIP MR imaging and fluorescent microsphere measurements of reduction in tumor perfusion (r = 0.722, P < .012). CONCLUSIONS: TRIP MR imaging provides accurate semiquantitative measurement of perfusion reduction during TAE in rabbit liver tumors.

Rabbit VX2 tumors as an animal model of uterine fibroids and for uterine artery embolization.

PURPOSE: To determine the suitability of the rabbit VX2 tumor animal model for uterine fibroids and uterine artery embolization (UAE). MATERIALS AND METHODS: The authors implanted and grew one uterine VX2 tumor per rabbit in six rabbits. UAE was performed by using 100-300 microm embolic particles and confirmed with x-ray digital subtraction angiography, magnetic resonance (MR) imaging, and necropsy. Unenhanced and contrast medium-enhanced MR images of VX2 tumors were obtained before and after UAE. Relative MR signal-to noise-ratio (SNR) was measured in the uterine VX2 tumor and in normal uterine tissue before and after UAE and compared by using a paired t-test (P = .05). RESULTS: VX2 uterine tumors were successfully grown, and both VX2 tumor presence in the uterus and UAE were seen angiographically and confirmed with necropsy in all six rabbits. Statistically significant reductions in relative SNRs were measured in tumors (SNR before UAE, 15.3 +/- 5.15; SNR after UAE, 3.84 +/- 3.94; P < .0001). No statistically significant decrease in SNR was measured in normal uterine tissue before and after UAE (P = .63 for the right uterine horn and P = .93 for the left uterine horn). CONCLUSION: Rabbit VX2 uterine tumors may be a suitable animal model of uterine fibroids and UAE.

Neurocognitive abilities in children with adenotonsillar hypertrophy.

OBJECTIVE: Sleep apnea is one of the most deleterious disorders in children with adenotonsillar hypertrophy because it can induce hypoxemia of brain. Sleep apnea may lead to failure to thrive or to physical and mental delay in development, including cognitive disturbances. The aim of this study was to analyze the influence of adenotonsillar hypertrophy, causing obstructive sleep apnea on neurocognitive abnormalities. We were interested in sensorimotor coordination, perception, memory, learning ability, concentration, focused attention and language reception. MATERIALS AND METHODS: We examined 221 children. One-hundred and seventeen children had sleep apnea caused by adenotonsillar hypertrophy: 87 children aged 6-9 years and 34 children aged 10-13 years. The control group, without adenotonsillar hypertrophy, consisted of 104 healthy children. Both groups of children with and without apnea were examined psychologically to determine abilities and minor neurocognitive deficit. The token test (TT), diagnosis test of brain dysfunction (DCS-test), Luria auditory verbal learning test (LAVLT) and Rey complex figure test (RCFT) were applied to both groups. The tests: TT, DCS-test, RCFT were used to investigate the level of sensorimotor integration and perception processes. Memory and learning abilities were measured using LAVLT. The TT assessed language dysfunction in children. RESULTS: This study shows that adenotonsillar hypertrophy in children aged 6-9 years is associated with neurocognitive abnormalities such as: memory problems, concentration of attention deficits, learning disability, language dysfunction, lower sensorimotor integration and perception. The older children (aged 10-13 years) with adenotonsillar hypertrophy had memory problems and learning disabilities. They are likely to be caused by of concentration of attention deficits. The older children were found to have more severe language dysfunction. CONCLUSIONS: Our study shows that sleep apnea may lead to neurocognitive deficits. The results may be helpful in the process of making decision for or against surgery in doubtful cases. It is important to know the problems connected with apnea in order to recognize them and help the child develop by providing adequate treatment and cognitive stimulation.

Autologous hematopoietic stem cell transplantation in patients with refractory Crohn's disease.

BACKGROUND & AIMS: Crohn's disease (CD) is an immunologically mediated inflammatory disease of the gastrointestinal tract. Due to a high morbidity and/or an increase in mortality in refractory cases, a new treatment approach is needed. In theory, maximum immune ablation by autologous hematopoietic stem cell transplantation (HSCT) can induce a remission. METHODS: We conducted a phase 1 HSCT study in 12 patients with refractory CD. Candidates were younger than 60 years of age with a Crohn's Disease Activity Index (CDAI) of 250-400 despite conventional therapies including infliximab. Peripheral blood stem cells were mobilized with cyclophosphamide and granulocyte colony-stimulating factor and CD34 + enriched. The immune ablative (conditioning) regimen consisted of 200 mg/kg cyclophosphamide and 90 mg/kg equine antithymocyte globulin. RESULTS: The procedure was well tolerated with anticipated cytopenias, neutropenic fever, and disease-related fever, diarrhea, anorexia, nausea, and vomiting. The median days for neutrophil and platelet engraftment were 9.5 (range, 8-11) and 9 (range, 9-18), respectively. The initial median CDAI was 291 (range, 250-358). Symptoms and CDAI improved before hospital discharge, whereas radiographic and colonoscopy findings improved gradually over months to years following HSCT. Eleven of 12 patients entered a sustained remission defined by a CDAI < or =150. After a median follow-up of 18.5 months (range, 7-37 months), only one patient has developed a recurrence of active CD, which occurred 15 months after HSCT. CONCLUSIONS: Autologous HSCT may be performed safely and has a marked salutary effect on CD activity. A randomized study will be needed to confirm the efficacy of this therapy.

[Thoracic sympathectomy performed by videothoracoscopic technique]. / Zabiegi sympatektomii piersiowej wykonywane metoda wideotorakoskopowa.

UNLABELLED: Thoracic sympathectomy is a method for a segmental elimination of functions of the sympathetic system by the excision of its Th2-Th3 ganglia. The procedure can be performed both using open and videoscopic technique. OBJECTIVE: The purpose of the study was the evaluation of efficacy of videoscopic thoracic sympathectomy. MATERIAL AND METHOD: From 1993 to 2003 we performed 53 videoscopic thoracic sympathectomies in patients with Raynaud's syndrome and upper limb hyperhidrosis. RESULTS: In all patients that underwent thoracic sympathectomy we obtained a positive reaction to a segmental excision of the sympathetic trunk. Patients with Raynaud's showed a significant improvement in symptoms in 76% of cases after a 4-year observation while patients with hyperhidrosis in 100%. The time of hospitalisation was 3.5 days in average. Postoperative complications were observed in two patients (3.7%). Videoscopic thoracic sympathectomy provides good therapeutic and cosmetic results and deserves more common use compared with open technique.

[CD11b and CD62L receptors expression on neutrophils after laparoscopic versus open cholecystectomy]. / Ekspresja receptorów CD11b i CD62L na powierzchni neutrofilów obojetnochlonnych po cholecystektomii laparoskopowej w porównaniu z cholecystektomia klasyczna.

UNLABELLED: The development of immunology correlated with surgery enables close recognition of multiple mechanisms responsible for more frequent complications observed after open surgical procedures than after minimally invasive operations. OBJECTIVE: Evaluation of selected elements of non-specific immunity in patients undergoing open cholecystectomy (OC) versus laparoscopic cholecystectomy (LC). MATERIAL AND METHODS: 30 postmenopausal females with non-complicated cholecystolithiasis were analysed. Both OC and LC was performed in 15 cases. Blood samples for an analysis were collected 24 hours before surgery and 24 and 72 hours postoperatively. Qualitative changes of neutrophils measured by the expression of CD11b and CD62L receptors on their surface without or with formyl-methionyl-leucyl-phenylalanine (fMLP) stimulation were evaluated. RESULTS: The expression of CD11b and CD62L receptors show no significant changes in patients that underwent LC while patients that underwent OC had significant changes 24 hours postoperatively compared both with their preoperative values and values observed in patients after LC. CONCLUSION: The activation of neutrophils measured by changes of the expression of CD11b and CD62L receptors on their surface is connected with the magnitude of trauma and is only observed in patients after OC.