Aberrant connectivity is implicated in many neurological and psychiatric disorders, including Alzheimer’s disease and schizophrenia. However, other than a few disease-associated candidate genes, we know little about the degree to which genetics play a role in the brain networks; we know even less about specific genes that influence brain connections. Twin and family-based studies can generate estimates of overall genetic influences on a trait, but genome-wide association scans (GWASs) can screen the genome for specific variants influencing the brain or risk for disease. To identify the heritability of various brain connections, we scanned healthy young adult twins with high-field, high-angular resolution diffusion MRI. We adapted GWASs to screen the brain’s connectivity pattern, allowing us to discover genetic variants that affect the human brain’s wiring. The association of connectivity with the SPON1 variant at rs2618516 on chromosome 11 (11p15.2) reached connectome-wide, genome-wide significance after stringent statistical corrections were enforced, and it was replicated in an independent subsample. rs2618516 was shown to affect brain structure in an elderly population with varying degrees of dementia. Older people who carried the connectivity variant had significantly milder clinical dementia scores and lower risk of Alzheimer’s disease. As a posthoc analysis, we conducted GWASs on several organizational and topological network measures derived from the matrices to discover variants in and around genes associated with autism ( MACROD2 ), development ( NEDD4 ), and mental retardation ( UBE2A ) significantly associated with connectivity. Connectome-wide, genome-wide screening offers substantial promise to discover genes affecting brain connectivity and risk for brain diseases.
Commentary: larazotide acetate ‐ an exciting new development for coeliac patients? Authors’ reply
Summary Background Coeliac disease, an autoimmune disorder triggered by gluten ingestion, is managed by a gluten‐free diet ( GFD ), which is difficult for many patients. Larazotide acetate is a first‐in‐class oral peptide that prevents tight junction opening, and may reduce gluten uptake and associated sequelae. Aim To evaluate the efficacy and tolerability of larazotide acetate during gluten challenge. Methods This exploratory, double‐blind, randomised, placebo‐controlled study included 184 patients maintaining a GFD before and during the study. After a GFD run‐in, patients were randomised to larazotide acetate (1, 4, or 8 mg three times daily) or placebo and received 2.7 grams of gluten daily for 6 weeks. Outcomes included an experimental biomarker of intestinal permeability, the lactulose‐to‐mannitol ( LAMA ) ratio and clinical symptoms assessed by Gastrointestinal Symptom Rating Scale ( GSRS ) and anti‐transglutaminase antibody levels. Results No significant differences in LAMA ratios were observed between larazotide acetate and placebo groups. Larazotide acetate 1‐mg limited gluten‐induced symptoms measured by GSRS ( P = 0.002 vs. placebo). Mean ratio of anti‐tissue transglutaminase IgA levels over baseline was 19.0 in the placebo group compared with 5.78 ( P = 0.010), 3.88 ( P = 0.005) and 7.72 ( P = 0.025) in the larazotide acetate 1‐, 4‐, and 8‐mg groups, respectively. Adverse event rates were similar between larazotide acetate and placebo groups. Conclusions Larazotide acetate reduced gluten‐induced immune reactivity and symptoms in patients with coeliac disease undergoing gluten challenge and was generally well tolerated; however, no significant difference in LAMA ratios between larazotide acetate and placebo was observed. Results and design of this exploratory study can inform the design of future studies of pharmacological interventions in patients with coeliac disease.
Vascular burden and Alzheimer disease pathologic progression
Guidelines for Pathologic Diagnosis of Malignant Mesothelioma: 2012 Update of the Consensus Statement from the International Mesothelioma Interest Group
Context .—Malignant mesothelioma (MM) is an uncommon tumor that can be difficult to diagnose. Objective .—To provide updated practical guidelines for the pathologic diagnosis of MM. Data Sources .—Pathologists involved in the International Mesothelioma Interest Group and others with an interest in the field contributed to this update. Reference material includes peer-reviewed publications and textbooks. Conclusions .—There was consensus opinion regarding (1) distinction of benign from malignant mesothelial proliferations (both epithelioid and spindle cell lesions), (2) cytologic diagnosis of MM, (3) key histologic features of pleural and peritoneal MM, (4) use of histochemical and immunohistochemical stains in the diagnosis and differential diagnosis of MM, (5) differentiation of epithelioid MM from various carcinomas (lung, breast, ovarian, and colonic adenocarcinomas, and squamous cell and renal cell carcinomas), (6) diagnosis of sarcomatoid mesothelioma, (7) use of molecular markers in the diagnosis of MM, (8) electron microscopy in the diagnosis of MM, and (9) some caveats and pitfalls in the diagnosis of MM. Immunohistochemical panels are integral to the diagnosis of MM, but the exact makeup of panels used is dependent on the differential diagnosis and on the antibodies available in a given laboratory. Immunohistochemical panels should contain both positive and negative markers. It is recommended that immunohistochemical markers have either sensitivity or specificity greater than 80% for the lesions in question. Interpretation of positivity generally should take into account the localization of the stain (eg, nuclear versus cytoplasmic) and the percentage of cells staining (>10% is suggested for cytoplasmic membranous markers). These guidelines are meant to be a practical reference for the pathologist.
Hexanucleotide repeat expansions in
C9ORF72
in the spectrum of motor neuron diseases
Abstract Purpose: PACS 01 trial demonstrated that the sequential adjuvant chemotherapy with FEC100 followed by docetaxel (D) significantly improves disease-free and overall survival in node-positive(N+) early breast cancer (BC). However, Triple negative (TN) and ER+/ PR-/HER2− subgroups are significantly associated to a worse prognosis even after adjunction of D. As Ixabepilone (Ixa) has notable preclinical and clinical activity in these subgroups, the PACS 08 trial aims to compare standard FEC100-D regimen to 3 cycles of FEC100 followed by 3 cycles of Ixa. We report the preliminary results of the toxicity profile. Patients and methods: Patients (pts) had localized resectable unilateral ER-/PR-/HER2− or ER+/PR-/HER2− BC. Main inclusion criteria were: age<70 years, normal cardiac, hepatic, haematological and renal functions. Arm A: pts received 3 cycles of FEC100 (F and C, each at 500 mg/m2, E 100 mg/m2, every 3 weeks) followed by 3 cycles of D (100 mg/m2 every 3 weeks); Arm B, Ixa 40 mg/m2 replaced D. Radiotherapy was mandatory after conservative surgery and endocrine therapy was given to ER+ pts. A 5% absolute difference in disease-free survival at 5 years is the main statistical end-point. Results: Between October 2007 and September 2010, 762 pts with TNBC or ER+/PR-/HER2− BC were enrolled. Recruitment was interrupted due to BMS decision to stop Ixa development in adjuvant setting. Main pts characteristics were well balanced between the 2 arms: median age 53 years, postmenopausal 57.8%, conservative surgery 68.4%, node positive 59.5%. A total of 755 pts were evaluable for safety. Treatment was completed for 93.4% and 86.1% of pts in arms A and B, respectively. During FEC100 sequence, toxicities were well balanced between the two arms. From cycle 4, whereas Gr3/4 sensory neurotoxicity (12pts; 3.5%) and thrombopenia (7pts; 2%) were reported in Ixa arm, none of these toxicities was reported in the D arm (p0.001). There were significantly more Gr3/4 neutropenia on day 21 in Ixa arm (13pts, 6.6% vs 4pts, 1.9%; p<10.005). No significant difference was observed for febrile neutropenia. Fewer cutaneous toxicities were observed in Ixa arm (2pts, 0.6% vs 10pts, 2.6%; p<0.05). No significant difference was observed neither for motor neurotoxicity or hepatic function between two arms. More pts discontinued treatment in Ixa arm compared to D arm (49pts (13%) vs 26pts (7%), p<0.05). Main reasons were Gr3/4 haematological adverse events (AE) and Gr3/4 neurotoxicities for Ixa arm and due to GR3/4 haematological AE for D arm. One non expected Gr4 bullous dermatitis was reported during the first Ixa cycle. 2 deaths due to septic shock occured in Ixa arm (both at cycle 4 for a 56- and a 66-year-old woman). However, according to the IDMC no obvious precipitating factor questioning the Ixa arm was identified. Conclusion: Our results indicate that D arm is more often associated to significant haematological toxicities, whereas both neurotoxicities and haematological toxicities are reported in the Ixa arm. Although significantly more pts discontinued treatment due to adverse events in Ixa arm compared to D arm, Ixa may still represent a promising therapeutic option for pts in the adjuvant setting especially for poor prognosis BC. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-18-04.
Detection and Measurement of Experimentally Produced Aortic Regurgitation by Means of Indicator-Dilution Curves Recorded from the Left Ventricle
In dogs studied without thoracotomy the detection of immediately appearing indicator in the left ventricle following its injection approximately 1 cm downstream from the aortic valve can be used as a reliable index of the presence or absence of aortic regurgitation. With this type of injection and under the conditions of these experiments, the ratio of the area encompassed by the immediately appearing portion of the dilution curve recorded from the left ventricle to the area encompassed by the primary portion of the curve recorded at the femoral artery bears a close positive correlation (correlation coefficient: 0.9) to the severity of aortic regurgitation as estimated by back perfusion of the valve at necropsy. Within limitations, the position of the tip of the sampling catheter in the left ventricle in dogs with aortic regurgitation is not an important determinant of the amount of immediately appearing indicator detected in this chamber. Furthermore, although the amount of indicator detected in the left ventricle following injections of very short duration is time-dependent, if the duration of the injection is extended to cover the full systolic or diastolic phase of one heartbeat or continues over one or more heartbeats, the exact timing of this injection in relation to the cardiac cycle is not an important determinant of this variable. It is concluded that under these conditions the positive correlation established between the amount of immediately appearing dye detected in the left ventricle (expressed as the regurgitant fraction) and the severity of aortic regurgitation determined by back perfusion at necropsy can be used as a valid means of estimating the severity of aoritic regurgitation in dogs. The applicability of this indicator-dilution method to the study of clinical aortic reguragitation merits further study.
Physiologic consequences of total hemispherectomy in the monkey