Online repetitive transcranial magnetic stimulation (TMS) to the parietal operculum disrupts haptic memory for grasping

The parietal operculum (OP) contains haptic memory on the geometry of objects that is readily transferrable to the motor cortex but a causal role of OP in memory‐guided grasping is only speculative. We explored this issue by using online high‐frequency repetitive transcranial magnetic stimulation (rTMS). The experimental task was performed by blindfolded participants acting on objects of variable size. Trials consisted in three phases: haptic exploration of an object, delay, and reach‐grasp movement onto the explored object. Motor performance was evaluated by the kinematics of finger aperture. Online rTMS was applied to the left OP region separately in each of the three phases of the task. The results showed that rTMS altered grip aperture only when applied in the delay phase to the OP. In a second experiment a haptic discriminative (match‐to‐sample) task was carried out on objects similar to those used in the first experiment. Online rTMS was applied to the left OP. No psychophysical effects were induced by rTMS on the detection of explicit haptic object size. We conclude that neural activity in the OP region is necessary for proficient memory‐guided haptic grasping. The function of OP seems to be critical while maintaining the haptic memory trace and less so while encoding it or retrieving it. Hum Brain Mapp 36:4262–4271, 2015. © 2015 Wiley Periodicals, Inc .     

LYM2-dependent chitin perception limits molecular flux via plasmodesmata

Chitin acts as a pathogen-associated molecular pattern from fungal pathogens whose perception triggers a range of defense responses. We show that LYSIN MOTIF DOMAIN-CONTAINING GLYCOSYLPHOSPHATIDYLINOSITOL-ANCHORED PROTEIN 2 (LYM2), the Arabidopsis homolog of a rice chitin receptor-like protein, mediates a reduction in molecular flux via plasmodesmata in the presence of chitin. For this response, lym2-1 mutants are insensitive to the presence of chitin, but not to the flagellin derivative flg22. Surprisingly, the chitin-recognition receptor CHITIN ELCITOR RECEPTOR KINASE 1 (CERK1) is not required for chitin-induced changes to plasmodesmata flux, suggesting that there are at least two chitin-activated response pathways in Arabidopsis and that LYM2 is not required for CERK1-mediated chitin-triggered defense responses, indicating that these pathways are independent. In accordance with a role in the regulation of intercellular flux, LYM2 is resident at the plasma membrane and is enriched at plasmodesmata. Chitin-triggered regulation of molecular flux between cells is required for defense responses against the fungal pathogen Botrytis cinerea, and thus we conclude that the regulation of symplastic continuity and molecular flux between cells is a vital component of chitin-triggered immunity in Arabidopsis.     

Efficacy of spectacles in persons with albinism

INTRODUCTION: Patients with albinism have varying degrees of reduced vision, strabismus, iris transillumination, nystagmus, fundus hypopigmentation, and foveal hypoplasia. High refractive errors are common, but reduced vision persists due to nonrefractive factors, causing reluctance by some clinicians to prescribe spectacles. We sought to evaluate the effect of spectacle correction of refractive error on clinical findings and recorded compliance with refractive corrections, as little detailed data exist. METHODS: We prospectively examined 35 consecutive patients with albinism for whom glasses had been prescribed to determine if objective improvement in recognition visual acuity (VA), strabismus, anomalous head posture (AHP), fusion, or stereoacuity occurred with refractive correction. Parents or patients reported compliance with glasses wear (excellent: >75% of awake hours; good: 50-75% of awake hours; fair: 26-50% of awake hours; poor: <25%). RESULTS: Median age was 9.5 years (range: 3 to 30). Median refractive correction was 1.875 D spherical equivalent (range: -9.75 to +8.88 D). Glasses wear was initiated at a median age of 14 months (range: 3 months to 14 years). Mean binocular VA at distance was 20/80.9 corrected and 20/107.6 uncorrected ( P < 0.001). Mean VA at near was 20/28.4 corrected and 20/41 uncorrected ( P < 0.001). Mean strabismic deviation was 7.2 PD with glasses and 10.0 PD without glasses at distance ( P = 0.006) and 10.8 PD with glasses and 14 PD without glasses at near ( P = 0.042). Mean AHP at distance was 8.3 degrees with glasses and 7.3 degrees without glasses at distance ( P = 0.327) and 4.7 degrees both with and without glasses at near ( P = 0.308). Twenty-one patients had fusion with or without glasses, two had fusion only with glasses, and one patient had fusion only without glasses. The other patients did not have any detectable degree of fusion. Twenty-seven individuals had no stereoacuity with or without glasses, five had gross stereoacuity of 3000 seconds of arc both with and without glasses, and three had gross stereoacuity only while wearing glasses. Compliance was excellent in 29 patients, fair in four, and poor in two. CONCLUSION: This prospective study showed a significant improvement in corrected VA and alignment in persons with albinism, despite overall subnormal acuity. Some individuals also experienced improvement in binocular alignment and AHP. Compliance with spectacles was generally good. Therefore, refractive correction should be encouraged in persons with albinism as improvement in visual function is likely to occur.     

A review of Ontario's revised drug cost programs.

Ontario's PARCOST program was introduced in 1970. This paper examines the changes wrought in the program since its inception and the economic and political reasons for those changes. It describes the components of the pharmacist's claim, the nature of price controls, and the problems with formulary decisions. The authors suggest that the driving force behind budget restraints is cost containment through lower drug prices with little emphasis on therapeutic considerations.     

Synthesis and beta-adrenergic antagonism of 2-(aryloxy)-1-(2-piperidyl)ethanols

A series of erythro- and threo-2-(aryloxy)-1-(2-piperidyl)ethanol derivatives (3) was synthesized from 2-(2-oxiranyl)pyridine for evaluation as beta-antagonists. Most compounds displayed high competitive beta-blocking potency, but they lacked significant beta 1/beta 2 selectivity. The 1-naphthoxy derivative erythro-3b was 17 (beta 1) and 33 (beta 2) times more potent than its open-chain analogue, propranolol. Within the whole series, erythro-3 diastereomers were more potent beta-blockers than the threo-3 isomers, and the potency of the latter seems to be rather insensitive to structural modification. The effect of N-methylation and of interposition of an alkyl chain between the aromatic ring and the side chain, while being detrimental to beta-blocking activity, was less marked than in the classic (aryloxy)propanolamine blockers.     

Primary cardiac amyloidosis: an angiocardiographic clue to early diagnosis

Restrictive cardiomyopathy produced by primary cardiac amyloidosis may have a clinical syndrome identical to noncalcific constrictive pericarditis. We report two patients with amyloidosis and restrictive physiology who had enlarged papillary muscles shown on left ventricular angiocardiogram. Rapid volume expansion with normal saline failed to produce ventricular filling pressure equilibration as in occult constrictive pericarditis. The absence of diastolic pressure equilibration and enlarged papillary muscles may permit early diagnosis of cardiac amyloidosis.     

Pseudoaneurysms complicating organ transplantation: roles of CT, duplex sonography, and angiography

In a retrospective study of proved pseudoaneurysms (PAs) in 15 patients with transplanted organs (11 liver, three kidney, one pancreas), the results of computed tomography (CT), duplex sonography, and angiography were reviewed. Of the 15 cases of PA, eight occurred at the arterial anastomosis and seven were nonanastomotic. Three of the eight anastomotic PAs were caused by infection. Of the seven nonanastomotic PAs, four were caused by percutaneous biopsy, two were caused by infection, and one was of undetermined cause. In nine (60%) of the 15 patients the PAs were incidentally detected at imaging studies performed for other reasons. Diagnosis requires a high degree of suspicion. CT was performed in nine cases and duplex sonography in ten. The diagnosis of PA was made with CT in six (67%) patients and with duplex sonography in five (50%). CT and duplex sonography could not enable diagnosis when the PA was small, when the arterial anastomosis was not included in the field of study, or when enhancement with intravenously administered contract material was suboptimal. Angiography depicted the PAs in all 15 patients. In three liver transplant recipients with gastrointestinal tract bleeding, the causative PAs were detected only with angiography.