Basic fibroblast growth factor: effects on matrix remodeling, receptor expression, and transduction pathway in human periosteal fibroblasts with FGFR2 gene mutation.

The Crouzon syndrome, which is associated with fibroblast growth factor receptor (FGFR2) mutations, is characterized by premature fusion of cranial sutures. We used an in vitro model of cultured periosteal fibroblasts from normal subjects and from Crouzon patients with FGFR2 mutation. We analyzed the matrix turnover rate and the effects of adding FGF2 by evaluating fibronectin synthesis and the activity of some proteolytic enzymes. To assess the role of some FGF signaling molecules involved in FGFR2 regulation, we studied Grb2 tyrosine phosphorylation and the phosphotyrosine proteins associated with Grb2. The iodinate FGF binding assay was performed to quantify FGFR expression. Compared with normal fibroblasts, fibronectin synthesis was decreased in Crouzon fibroblasts, and protease activities in cells and medium were enhanced, suggesting that excess fibronectin catabolism is present. Differences were more marked when FGF2 was added. Very few phosphoproteins were visible in anti-Grb2 immunoprecipitations from Crouzon fibroblasts, which showed a significant increase in the number of high-affinity and low-affinity FGF2 receptors. These results suggest that the abnormal genotype and the Crouzon cellular phenotype are related. To compensate the low levels of tyrosine phosphorylation, Crouzon cells might increase the numbers of FGFR2, thus increasing the cell surface binding sites for FGF2.     

Cancer‐associated somatic DICER1 hotspot mutations cause defective miRNA processing and reverse‐strand expression bias to predominantly mature 3p strands through loss of 5p strand cleavage

Our group recently described recurrent somatic mutations of the miRNA processing gene DICER1 in non‐epithelial ovarian cancer. Mutations appeared to be clustered around each of four critical metal‐binding residues in the RNase IIIB domain of DICER1. This domain is responsible for cleavage of the 3′ end of the 5p miRNA strand of a pre‐mRNA hairpin. To investigate the effects of these cancer‐associated 'hotspot' mutations, we engineered mouse DICER1‐deficient ES cells to express wild‐type and an allelic series of the mutant DICER1 variants. Global miRNA and mRNA profiles from cells carrying the metal‐binding site mutations were compared to each other and to wild‐type DICER1. The miRNA and mRNA profiles generated through the expression of the hotspot mutations were virtually identical, and the DICER1 hotspot mutation‐carrying cells were distinct from both wild‐type and DICER1‐deficient cells. Further, miRNA profiles showed that mutant DICER1 results in a dramatic loss in processing of mature 5p miRNA strands but were still able to create 3p strand miRNAs. Messenger RNA (mRNA) profile changes were consistent with the loss of 5p strand miRNAs and showed enriched expression for predicted targets of the lost 5p‐derived miRNAs. We therefore conclude that cancer‐associated somatic hotspot mutations of DICER1, affecting any one of four metal‐binding residues in the RNase IIIB domain, are functionally equivalent with respect to miRNA processing and are hypomorphic alleles, yielding a global loss in processing of mature 5p strand miRNA. We further propose that this resulting 3p strand bias in mature miRNA expression likely underpins the oncogenic potential of these hotspot mutations. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Parenchymal sparing operations for bronchogenic carcinoma

By the end of the 1950s, the principles of tracheobronchial and pulmonary artery (PA) reconstruction had been established, and their successful clinical application had taken place. It was not until very recently, however, that these techniques aroused widespread interest among thoracic surgeons as a means to achieve complete cancer resection while preserving functioning lung parenchyma. At the present time, sleeve resection of the bronchus and/or PA has a definite role in the surgical management of lung cancer. Growing interest in this field is evidenced by an increasing number of technical variations intended to adapt the basic technique to the different anatomical settings. Also pitfalls, complications, and their prevention and treatment are being extensively described. Last but not least, functional and oncological long-term results, comparing favorably with those of more extended resections, are being reported by many groups. This demonstrates that sleeve lobectomy is no longer reserved only for particularly skillful surgeons. Sleeve lobectomy has achieved its rightful position among the techniques commonly used in thoracic surgery after 40 years of improving understanding and alternating enthusiasm and legitimate doubts.     

Exercise renal scintigraphy shows renal ischemia in a transplanted kidney

Exercise renography is essentially a research method to investigate hypertension and has very limited clinical application. Captopril renography has long been used to study renal artery stenosis causing hypertension with good results. The authors describe a patient with a transplanted kidney supplied by reversal of flow via the external iliac artery. A "steal phenomenon" of the kidney related to ambulation was considered likely. Ischemia of the transplanted kidney was revealed by exercise renography, which showed parenchymal trapping of radiotracer as a result of exercise.     

Comparison of the Canadian CT Head Rule and the New Orleans Criteria in patients with minor head injury

Context  Current use of cranial computed tomography (CT) for minor head injury is increasing rapidly, highly variable, and inefficient. The Canadian CT Head Rule (CCHR) and New Orleans Criteria (NOC) are previously developed clinical decision rules to guide CT use for patients with minor head injury and with Glasgow Coma Scale (GCS) scores of 13 to 15 for the CCHR and a score of 15 for the NOC. However, uncertainty about the clinical performance of these rules exists. Objective  To compare the clinical performance of these 2 decision rules for detecting the need for neurosurgical intervention and clinically important brain injury. Design, Setting, and Patients  In a prospective cohort study (June 2000-December 2002) that included 9 emergency departments in large Canadian community and university hospitals, the CCHR was evaluated in a convenience sample of 2707 adults who presented to the emergency department with blunt head trauma resulting in witnessed loss of consciousness, disorientation, or definite amnesia and a GCS score of 13 to 15. The CCHR and NOC were compared in a subgroup of 1822 adults with minor head injury and GCS score of 15. Main Outcome Measures  Neurosurgical intervention and clinically important brain injury evaluated by CT and a structured follow-up telephone interview. Results  Among 1822 patients with GCS score of 15, 8 (0.4%) required neurosurgical intervention and 97 (5.3%) had clinically important brain injury. The NOC and the CCHR both had 100% sensitivity but the CCHR was more specific (76.3% vs 12.1%, P<.001) for predicting need for neurosurgical intervention. For clinically important brain injury, the CCHR and the NOC had similar sensitivity (100% vs 100%; 95% confidence interval [CI], 96%-100%) but the CCHR was more specific (50.6% vs 12.7%, P<.001), and would result in lower CT rates (52.1% vs 88.0%, P<.001). The values for physician interpretation of the rules, CCHR vs NOC, were 0.85 vs 0.47. Physicians misinterpreted the rules as not requiring imaging for 4.0% of patients according to CCHR and 5.5% according to NOC (P = .04). Among all 2707 patients with a GCS score of 13 to 15, the CCHR had sensitivities of 100% (95% CI, 91%-100%) for 41 patients requiring neurosurgical intervention and 100% (95% CI, 98%-100%) for 231 patients with clinically important brain injury. Conclusion  For patients with minor head injury and GCS score of 15, the CCHR and the NOC have equivalent high sensitivities for need for neurosurgical intervention and clinically important brain injury, but the CCHR has higher specificity for important clinical outcomes than does the NOC, and its use may result in reduced imaging rates.      

Ultrastructural ciliary findings in nasal obstructive diseases

Specific ultrastructural findings have widely been described in case of obstructive nasal diseases due to congenital defects. Ciliary impairment has in particular been observed as the main pathological feature in these conditions. In this study, nasal mucosal samples from different pathologies have been collected via the "brushing" technique and analysed by transmission electron microscopy. TEM analysis was focused on specific features, such as the numerical array of peripheral and central doublets of the cilium axoneme, including eventual microtubular disarrangement; partial or total loss of inner and/or outer dynein arms; defects of radial spokes and nexin links; disorientation of the ciliary axis in closely adjacent cilia, calculating the angle between the line crossing the central microtubular core and the horizontal ciliary axis and compound cilia (CC). Statistical comparison was carried out between study and control groups. A significant incidence of organic ciliary defects was found not only in patients with inflammatory processes, but mostly in those supposed to have a long-lasting nasal respiratory disease due to mechanical stenosis in relation to septum deviation and turbinate hypertrophy. Prevalence and percentage of compound cilia were instead more related to inflammatory conditions. The "brushing" technique can be considered an easy and reliable method for the assessment of the condition of the nasal mucosa. According to the findings derived from this study, mechanical nasal obstruction seems to cause major alterations on the nasal ciliary arrangement, thus determining a functional impairment on the whole nasal function.     

Phenylbutyrate increases SMN gene expression in spinal muscular atrophy patients

Spinal muscular atrophy (SMA) is caused by insufficient levels of survival motor neuron (SMN) protein. Recently, we found that sodium 4-phenylbutyrate (PB), a well-tolerated FDA approved drug, enhances SMN gene expression in vitro. We provide here the first evidence that oral administration of PB (triButyrate significantly increases SMN expression in leukocytes of SMA patients. This finding provides a strong rationale to further investigate the effects of PB as also supported by preliminary clinical data.     

Apolipoprotein E epsilon4 allele differentiates the clinical response to donepezil in Alzheimer's disease

The existence of an association between apolipoprotein E (APOE) and Alzheimer's disease (AD) has been reported in several studies. The possession of an ApoE epsilon4 allele is now considered a genetic risk factor for sporadic AD. There has been a growing agreement about the role exerted by the ApoE epsilon4 allele on the neuropsychological profile and the rate of cognitive decline in AD patients. However, a more controversial issue remains about a possible influence of the APOE genotype on acetylcholinesterase inhibitor therapy response in AD patients. In order to address this issue, 81 patients diagnosed as having probable AD were evaluated by a complete neuropsychological test battery at the time of diagnosis (baseline) and after 12-16 months (retest). Patients were divided into two subgroups: (1) treated with donepezil at a dose of 5 mg once a day (n = 41) and (2) untreated (n = 40). Donepezil therapy was started after baseline evaluation. The APOE genotype was determined according to standardized procedures. We evaluated the possible effect of the APOE genotype on the neuropsychological tasks in relation to donepezil therapy. The statistical analysis of the results showed a global worsening of cognitive performances for all AD patients at the retest. Differences in the clinical outcome were analysed in the four subgroups of AD patients for each neuropsychological task. ApoE epsilon4 carriers/treated patients had improved or unchanged scores at retest evaluation for the following tasks: visual and verbal memory, visual attention and inductive reasoning and Mini Mental State Examination. These results indicate an effect of donepezil on specific cognitive domains (attention and memory) in the ApoE epsilon4 carriers with AD. This might suggest an early identification of AD patients carrying at least one epsilon4 allele as responders to donepezil therapy.