Morphometric study of Intratemporal course of facial nerve in relation to pneumatization of temporal bone—An original study

Introduction

Facial nerve (C.N VII) is the nerve of facial expression and communication. The intratemporal part of this nerve comprising tympanic and mastoid segments, is very vulnerable to injury during ear surgeries. Hence to safely navigate around this part of the nerve one has to be very familiar with 3D anatomy of the temporal bone and crucial landmarks present in relation to the nerve. Aim of this study is to know the exact morphometry of Intratemporal part of the facial nerve in relation to Pneumatization of temporal bone.

Computational modelling of phonological dyslexia: how does the DRC model fare?

This paper investigates the patterns of reading impairment in phonological dyslexia using computational modelling with the dual-route cascaded model of reading (DRC, Coltheart, Rastle, Perry, Langdon, & Ziegler, 2001). Systematic lesioning of nonlexical and phonological processes in DRC demonstrates that different lesions and severity of those lesions can reproduce features of phonological dyslexia including impaired reading of nonwords, relatively spared reading of words, an advantage for reading pseudohomophones. Using the same stimuli for model and for patients, lesions to DRC were also used to simulate the reading accuracy shown by three individuals with acquired phonological dyslexia. No single lesion could replicate the reading performance of all three individuals. In order to simulate reading accuracy for one individual a phonological impairment was necessary (addition of noise to the phoneme units), and for the remaining two individuals an impairment to nonlexical reading procedures (increasing the time interval between each new letter being processed) was necessary. We argue that no single locus of impairment (neither phonological nor nonlexical) can account for the reading impairments of all individuals with phonological dyslexia. Instead, different individuals have different impairments (and combinations of impairments) that together provide the spectrum of patterns found in phonological dyslexia.     

Altered thymic activity in early life: how does it affect the immune system in young adults?

The thymus is responsible for the maturation of lymphoid precursors into T cells, and is necessary to establish the T cell pool during prenatal and early postnatal life in humans. With the years, it undergoes a natural shrinking process, referred to as involution, suspected to be central in the decline of immune competence with aging, or immunosenescence. Here, we review the recent studies focusing on the immunological consequences of abnormal thymic development and thymectomy shortly after birth. These works highlight the importance of the thymic function in preserving immune efficacy throughout life, and provide insights into the development of immune aging.     

Proliferative index in phaeochromocytomas: does it predict the occurrence of metastases?

Evaluation of the malignant potential of phaeochromocytomas in the absence of metastases presents a formidable challenge to both clinicians and pathologists. Until now, no widely accepted clinical, histological, immunohistochemical or molecular method has become available to discriminate malignant from benign phaeochromocytomas. In other endocrine tumours, estimation of proliferative activity by MIB-1 immunostaining has emerged as a promising approach for the determination of metastatic potential. In this study, the utility of MIB-1 immunostaining as a predictive marker for the occurrence of metastases in phaeochromocytomas was evaluated. In addition, the density of S100-positive sustentacular cells was studied, since their depletion has been identified as a negative predictive marker in smaller series. Furthermore, several clinicopathological parameters were evaluated. One hundred and ten patients operated on for a total of 99 benign and 37 malignant phaeochromocytomas were studied. All malignant tumours had documented metastases. The histopathological diagnosis of primary tumours and metastases was reviewed and graded for angioinvasion, capsular extension, and intra-tumoural necrosis. The proliferative index (percentage of MIB-1-positive cells) and the density of S100-positive cells were assessed. In addition, age at resection, associated familial tumour syndromes, tumour size, and tumour location were recorded. Univariate analysis revealed statistically significant correlations between malignancy and proliferative index (p<0.0005) and depletion of S100-positive sustentacular cells (p<0.0005). Fifty per cent of the malignant, but none of the benign phaeochromocytomas had a proliferative index greater than 2.5%. Higher age at resection (p=0. 03), sporadic occurrence (p<0.0005), extra-adrenal location (p<0. 0005), tumour size (p<0.0005), and necrosis (p=0.03) were also significantly associated with malignancy. Logistic regression showed that proliferative index (p=0.0072), size (p=0.0022), and extra-adrenal location (p=0.0012) of the primary tumour were independently predictive for malignancy. In conclusion, this study indicates that assessing the proliferative activity of phaeochromocytomas by MIB-1 immunohistochemistry can predict the occurrence of metastases. The predictive value of S100 immunostaining, tumour size, and extra-adrenal location of the tumour was also confirmed.     

Two-dimensional static manipulation tasks: does force coordination depend on change of the tangential force direction?

Coordination of the grip force (GF) with a tangential force (TF, often referred to as load force) exerted along a certain line in space (i.e., one-dimensional tasks) during object manipulation has proved both to be high and based on feed-forward neural control mechanisms. However, GF–TF coordination deteriorates when the TF of one-dimensional task consecutively switches its direction (bidirectional task). In the present study, we aimed to explore GF–TF coordination in the generally neglected multi-dimensional manipulations. We hypothesized that the coordination would depend on the number of unidirectional and bidirectional orthogonal components of a two-dimensional TF exertion. Fourteen subjects traced various circular TF patterns and their orthogonal diameters shown on a computer screen by exerting a static TF. As expected, the unidirectional tasks revealed higher GF–TF coordination than the bidirectional ones (e.g., higher GF–TF correlations and GF gains, and lower GF/TF ratio). Regarding the circular tasks, most of the data were in line with the hypothesis revealing higher coordination associated with higher number of unidirectional components. Of particular importance could be that the circular tasks also revealed prominent time lags of GF with respect to TF, suggesting involvement of feedback mechanisms. We conclude that the force coordination in bidirectional static manipulations could be affected by changes in TF direction along either of its orthogonal components. The time lags observed from the circular tasks could be a consequence of the activity of sensory afferents, rather than of the visual feedback provided or the task complexity.     

Examination of the law of grotthus-draper: does ultrasound penetrate subcutaneous fat in humans?

One benefit of ultrasound over infrared modalities is its ability to penetrate subcutaneous fat. The purpose of this study was to compare tissue temperature rise during ultrasound treatments in humans with various thicknesses of subcutaneous fat in the medial gastrocnemius. Twenty males served as subjects. A 23-gauge hypodermic needle microprobe was inserted 3-cm deep into the medial portion of the anesthetized gastrocnemius, and connected to a thermocouple temperature gauge. We applied 15 ml of ultrasound gel, preheated to body temperature (37°C), to a 10-cm-diameter target area. Continuous ultrasound was delivered topically at 1.5 W/cm² for 10 minutes. During this time, the soundhead was moved at a speed of 4 cm per second, and the temperature was recorded every 30 seconds. The mean baseline temperature for all subjects was 35.4°C. The mean temperature increase was 4.9°C. We performed a regression analysis to test for correlation between fat thickness and tissue temperature rise of subjects. There was a small positive but insignificant correlation (r=.128). This supports the claim of Grotthus and Draper. Since subcutaneous fat does not serve as a barrier to therapeutic ultrasound, athletic trainers and physical therapists can expect comparable increases in muscle temperature when using this modality on people with varying thicknesses of adipose tissue.     

Physiology of the fasciculation potentials in amyotrophic lateral sclerosis: which motor units fasciculate?

We set out to study whether in amyotrophic lateral sclerosis (ALS) fasciculation potentials (FPs) arise from the most excitable motor units (MUs). We studied 70 patients with ALS and 18 subjects with benign fasciculation syndrome (BFS). Of the 56 eligible ALS patients, 31 had signs of reinnervation in the right first dorsal interosseous muscle selected for study, and 25 did not. Two needle electrodes were placed in different MUs in each studied muscle. We defined the most excitable MU as that first activated by minimal voluntary contraction. In muscles without reinnervation, the recording site with most frequent FPs had a higher probability of showing the first recruited MU (p < 0.001). No significant difference was found in other patients or in BFS subjects. In very early affected muscles, fasciculating MUs are the most likely to be recruited volitionally. This probably represents hyperexcitability at lower motor neuronal level.     

Just how does the cII selection system work in Muta™Mouse?

The lambda CII protein is an essential component in the lytic vs. lysogeny decision a bacteriophage makes upon infection of a host at low temperatures. The protein interacts with numerous phage promoters modulating the expression of the CI repressor, thus providing the mechanism for lysogenization soon after infection. The Big Blue and Muta Mouse are two widely used in vivo mutational model systems. The assays rely on retrievable lambda-based transgenes housing mutational targets (lacI or lacZ, respectively). The transgenes provide an elegant vehicle for the quantification of mutations sustained in virtually any tissue of the rodent. The use of the bacteriophage cII locus as an alternative, or additional mutational target for use with the Big Blue rodent system was first reported by Jakubczak et al. ([1996]: Proc Natl Acad Sci USA 93:9073-9078). More recently, this selection assay has been applied successfully to the Muta Mouse (Swiger et al. [1999]: Environ Mol Mutagen 33:201-207). The use of an Hfl bacterial strain and low temperature allows the determination of mutations sustained at the cII locus in either system, with high fidelity. The cII selection assay in the Big Blue relies on the presence of the lambda repressor protein CI. In contrast, the recombinant construct used to make the Muta Mouse transgene lacks functional CI protein. Nevertheless, we report an excellent system for quantifying mutations at the cII locus in Muta Mouse. Just how does cII selection work in the Muta Mouse? Written in the context of lambda recombinant genetics, this paper explores the question further.     

Retrospective evaluation of the treatment for breast cancer: how does the patient's personal experience of the treatment affect later adjustment to the illness?

The aim of the present study was the evaluation of patients' treatment experience for breast cancer and its possible associations with the illness adjustment process. To examine perception and experience of treatment during the diagnostic and the inpatient phase, as well as during chemo-and radiotherapy and during after-care, a self-compiled questionnaire was employed. To assess illness adjustment, the German version of the Hospital Anxiety and Depression Scale, the "Freiburger Fragebogen zur Krankheitsverarbeitung" and the "Ver?nderungsfragebogen des Erlebens und Verhaltens" were used. 126 patients participated in the study, all diagnosed for breast cancer during the past 5 years. We found an association between negative experience of all treatment phases (doctor-patient relationship, communication) and impaired adjustment process reflected by high anxiety and depression scores and more problematic coping strategies.     

Autoantibodies in the grocery shop: does quantity matter?

Testing for autoantibodies is an integrated part in the diagnostic process of many autoimmune diseases. As a consequence, the detection of autoantibodies is increasingly recognized in classification criteria and diagnostic guidelines. In this review, the question is addressed whether quantification of autoantibodies is clinically useful, not only in the diagnostic stage, but also during follow-up of patients with autoimmune diseases. It can be concluded that for a multitude of autoantibodies, there is sufficient evidence that the higher the amount of autoantibodies, the more likely that the patient has the respective autoimmune disease. Quantification is also of added value for monitoring therapeutic efficacy, although this depends on the type of therapy that is installed. The relation between rises in autoantibody levels and the occurrence of subsequent disease relapses, however, is far from absolute. Obviously, if quantification of autoantibodies is performed in the laboratory, results should also be reported quantitatively together with an appropriate interpretation for the clinician.