Mapping of multiple muscles with transcranial magnetic stimulation: absolute and relative test–retest reliability

The spatial accuracy of transcranial magnetic stimulation (TMS) may be as small as a few millimeters. Despite such great potential, navigated TMS (nTMS) mapping is still underused for the assessment of motor plasticity, particularly in clinical settings. Here, we investigate the within‐limb somatotopy gradient as well as absolute and relative reliability of three hand muscle cortical representations (MCRs) using a comprehensive grid‐based sulcus‐informed nTMS motor mapping. We enrolled 22 young healthy male volunteers. Two nTMS mapping sessions were separated by 5–10 days. Motor evoked potentials were obtained from abductor pollicis brevis (APB), abductor digiti minimi, and extensor digitorum communis. In addition to individual MRI‐based analysis, we studied normalized MNI MCRs. For the reliability assessment, we calculated intraclass correlation and the smallest detectable change. Our results revealed a somatotopy gradient reflected by APB MCR having the most lateral location. Reliability analysis showed that the commonly used metrics of MCRs, such as areas, volumes, centers of gravity (COGs), and hotspots had a high relative and low absolute reliability for all three muscles. For within‐limb TMS somatotopy, the most common metrics such as the shifts between MCR COGs and hotspots had poor relative reliability. However, overlaps between different muscle MCRs were highly reliable. We, thus, provide novel evidence that inter‐muscle MCR interaction can be reliably traced using MCR overlaps while shifts between the COGs and hotspots of different MCRs are not suitable for this purpose. Our results have implications for the interpretation of nTMS motor mapping results in healthy subjects and patients with neurological conditions.     

Fatal immune dysregulation due to a gain of glycosylation mutation in lymphocyte perforin

Mutations in the perforin gene (PRF1) are a common cause of the fatal immune dysregulation disorder, familial hemophagocytic lymphohistiocytosis (type 2 FHL, FHL2). Here we report a female infant born with biallelic PRF1 mutations: a novel substitution, D49N, and a previously identified in-frame deletion, K285del. We assessed the effects of each mutation on the cytotoxicity of human NK cells in which the expression of endogenous perforin was ablated with miR30-based short hairpin (sh) RNAs. Both mutations were detrimental for function, thereby explaining the clinically severe presentation and rapidly fatal outcome. We demonstrate that D49N exerts its deleterious effect by generating an additional (third) N-linked glycosylation site, resulting in protein misfolding and degradation in the killer cell. Our data provide a rationale for treating some cases of type 2 familial hemophagocytic lymphohistiocytosis, based on the pharmacologic inhibition or modification of glycosylation.     

Diversity,frequency and antifungal resistance of Candida species in patients with type 2 diabetes mellitus

Objective: To determine number, species of Candida and Candida resistance to antifungal therapy according to the metabolic control state and the associated salivary changes in patients with type 2 diabetes mellitus (DM2).

Materials and methods: Samples of non-stimulated saliva were collected from 52 patients with DM2. Salivary pH was measured and cultured on Sabouraud glucose agar and the values of CFU/ml were calculated. The species were presumptively identified using CHROMagar Candida^® plates, and identification was confirmed by polymerase chain reaction (PCR). C. albicans isolates were cultured on SGA tetracycline agar with nystatin and fluconazole diffusion disks to measure susceptibility.

Results: Sixty six percent of the yeasts isolated were Candida albicans, followed by C. glabrata (20.7%). In patients with decompensated DM2, there was an inverse association between HbA1c value and salivary pH. At higher levels of salivary acidification, a greater diversity and quantity of yeasts of the genus Candida were observed. With nystatin, higher inhibition was observed at lower pH.

Conclusions: The antifungal therapies could be more effective if it consider, qualitative salivary characteristics as pH, that could determine the susceptibility of species of Candida to at least to nystatin, which is the most used antifungal for treatment to oral candidiasis in patients with DM2.     

The clinical significance of cyclic citrullinated peptide antibodies: new data

Early diagnosis of rheumatoid arthritis (RA) is a challenge due to an insufficient specificity of its clinical signs and a low sensitivity of presently used clinico-laboratory criteria. Cyclic citrullinated peptide antibodies (CCPA) are nowadays considered the most promising diagnostic and prognostic RA marker. A heterogeneous group of citrullinated peptides are the target for CCPA. The sensitivity of CCPA is comparable to that of the rheumatoid factor (RF), while its specificity for this disease is much higher. CCPA detection may be very useful for diagnostics of early sero-negative RA, differential diagnosis between RA and other rheumatic diseases, and for the prognosis of severe erosive articular lesion. Simultaneous detection of RF and CCPA allow for early RA diagnostics, which is important for timely administration of a more aggressive basic antirheumatic therapy.     

Structure-Based Neuron Retrieval Across Drosophila Brains

Comparing local neural structures across large sets of examples is crucial when studying gene functions, and their effect in the Drosophila brain. The current practice of aligning brain volume data to a joint reference frame is based on the neuropil. However, even after alignment neurons exhibit residual location and shape variability that, together with image noise, hamper direct quantitative comparison and retrieval of similar structures on an intensity basis. In this paper, we propose and evaluate an image-based retrieval method for neurons, relying on local appearance, which can cope with spatial variability across the population. For an object of interest marked in a query case, the method ranks cases drawn from a large data set based on local neuron appearance in confocal microscopy data. The approach is based on capturing the orientation of neurons based on structure tensors and expanding this field via Gradient Vector Flow. During retrieval, the algorithm compares fields across cases, and calculates a corresponding ranking of most similar cases with regard to the local structure of interest. Experimental results demonstrate that the similarity measure and ranking mechanisms yield high precision and recall in realistic search scenarios.     

Breast Conservation After Neoadjuvant Chemotherapy

Background Tumor downstaging by preoperative neoadjuvant chemotherapy in patients with locally advanced breast tumors allows breast conservation in women who were previously candidates for mastectomy. Nevertheless, lumpectomy success in such cases cannot be fully achieved. The aim of this study was to create a quantitative tool for preoperative evaluation of the success of breast conservation in such patients.Methods The study population included 100 consecutive patients with stage II and III breast cancer who were designated for lumpectomy and 19 patients who were designated for mastectomy. All patients received neoadjuvant therapy. Breast-conserving surgery was offered in accordance with clinical and esthetic criteria. Demographic details and clinical, imaging, and pathologic information were collected from medical files. A decision protocol for classifying patients to lumpectomy or mastectomy was built by using the Classification and Regression Trees procedure based on preoperative characteristics.Results Three factors were found to be the main predictors for successful breast conservation: absence of diffuse microcalcifications as seen in the pretreatment mammogram, a postchemotherapy tumor size of < 25 mm, and the existence of a circumscribed lesion on mammography.Conclusions The use of these criteria as a basis for decision on the type of surgery may decrease the performance of unnecessary procedures.