Stimulus duration and pain in nerve conduction studies

Introduction: It is generally believed that a shorter stimulus duration is less painful in nerve conduction studies (NCS). We investigated whether a shorter duration stimulus is actually less painful when the same physiological effect, such as supramaximal stimulation, is achieved in motor NCS. Methods: The tibial nerve was stimulated at the ankle in 14 control subjects and the median nerve at the wrist in 20 subjects. Two stimulations of different durations were given blindly, and each subject was asked to report which was more painful. Results: A 0.2‐ms‐duration stimulus was significantly less painful than those with longer or shorter durations for the tibial nerve. For the median nerve, the 0.05‐ and 0.2‐ms durations were equally less painful than a 1‐ms‐duration stimulus. Conclusions: As a common duration for motor NCS, 0.2 ms seems appropriate, because the tibial nerve stimulation was more painful than the median nerve stimulation. Muscle Nerve, 2013     

Dissociations between the horizontal and dorsoventral axes in body‐size perception

Body size can vary throughout a person's lifetime, inducing plasticity of the internal body representation. Changes in horizontal width accompany those in dorsal‐to‐ventral thickness. To examine differences in the perception of different body axes, neural correlates of own‐body‐size perception in the horizontal and dorsoventral directions were compared using functional magnetic resonance imaging. Original and distorted (?30, ?10, +10 and +30%) images of the neck‐down region of their own body were presented to healthy female participants, who were then asked whether the images were of their own body or not based explicitly on body size. Participants perceived body images distorted by ?10% as their own, whereas those distorted by +30% as belonging to others. Horizontal width images yielded slightly more subjective own‐body perceptions than dorsoventral thickness images did. Subjective perception of own‐body size was associated with bilateral inferior parietal activity. In contrast, other‐body judgments showed pre‐supplementary motor and superior parietal activity. Expansion in the dorsoventral direction was associated with the left fusiform gyrus and the right inferior parietal lobule, whereas horizontal expansions were associated with activity in the bilateral somatosensory area. These results suggest neural dissociations between the two body axes: dorsoventral images of thickness may require visual processing, whereas bodily sensations are involved in horizontal body‐size perception. Somatosensory rather than visual processes can be critical for the assessment of frontal own‐body appearance. Visual body thickness and somatosensory body width may be integrated to construct a whole‐body representation.     

Orthognathic treatment for a patient with facial asymmetry associated with unilateral scissors-bite and a collapsed mandibular arch

Subapical mandibular surgeries have been used to correct vertical malocclusion and interdental problems associated with mandibular deformity. Subapical surgery to the anterior part of the mandible is applicable in many patients with anterior open bite and deepbite. Surgery of the posterior part of the mandible is needed less frequently than surgery of the anterior part. This case report describes the surgical-orthodontic treatment of a 21-year-old woman who underwent posterior subapical mandibular surgery. Her chief complaint was facial asymmetry, and she had a collapsed mandibular arch with a scissors-bite of the right premolars and molars. After subapical osteotomy, surgically assisted correction of the collapsed right mandibular arch was performed with a lingual arch appliance. Comprehensive orthodontic treatment was initiated in both arches after this correction. Le Fort I osteotomy and sagittal split ramus osteotomy were used to correct the facial asymmetry. Her facial appearance and temporomandibular problems were markedly improved, and she achieved a functional and stable occlusion after these treatments. This case report demonstrates the efficiency of posterior subapical mandibular surgery for a patient with a collapsed mandibular arch and a scissors-bite.     

Safety and effectiveness of ferric citrate hydrate in serum phosphorus management of patients with chronic kidney disease: a long-term,real-world,observational, post-marketing surveillance study

Clinical and Experimental Nephrology - Ferric citrate hydrate (FC) is an oral iron-based phosphate binder that is used to treat hyperphosphatemia in patients with chronic kidney disease (CKD). This...     

Relationship of physical distress to dizziness in patients with fibromyalgia

Conclusions: The feelings of dizziness and unsteadiness of the patients with fibromyalgia supposed specifically amplified by the hypersensitivity mechanism of CSS (central sensitivity syndrome) of them. The severity of subjective pain and physical distress according to the questionnaires were not correlated with the objective body sway on the stabilometer. Objectives: Fibromyalgia manifests primarily as chronic pain of the entire body, but is also often associated with a variety of physical symptoms including dizziness and unsteadiness. This study assessed whether objective measures of body sway and unsteadiness of them are associated with their subjective dizziness findings. Method: Subjects were 24 patients diagnosed with fibromyalgia, but one patient who had the past history of sudden deafness was excluded. The 23 patients were assessed by a stabilometer as the objective measures of body sway, and JFIQ (Japanese version of the fibromyalgia impact questionnaire), DHI (dizziness handicap inventory) and ABC (activities-specific balance confidence) as the subjective questionnaires. Results: The significant correlations were shown between the scores of JFIQ and DHI, JFIQ and ABC, and DHI and ABC. Then, the body sway index of stabilometer environmental area was significantly correlated with DHI score. However, the stabilometer index was not correlated neither with JFIQ or ABC.     

B7-H3 regulates the development of experimental allergic conjunctivitis in mice

B7-H3 negatively regulates Th1-mediated immune responses. Here, we aimed to investigate whether B7-H3 is involved in the development of murine experimental allergic conjunctivitis (EC), which is predominantly mediated by Th2 cells. Intraperitoneal injection of anti-B7-H3 Ab during the induction phase of EC significantly augmented the severity of EC evaluated as conjunctival eosinophil numbers and Ag-induced IL-5 production by splenocytes. Injection of anti-B7-H3 Ab during the effector phase of EC did not significantly affect the severity of EC. In addition, transfer of Ag-primed splenocytes treated with anti-B7-H3 Ab in vitro did not significantly affect the severity of EC, compared to the splenocytes treated with the control Ab. Thus, regulation of EC by blocking of B7-H3 was observed during the induction phase but not the effector phase. Moreover, this study provides a new notion that B7-H3 regulates not only Th1-mediated but also Th2-mediated immune reactions.     

Protein kinase A activation down-regulates, whereas extracellular signal-regulated kinase activation up-regulates sigma-1 receptors in B-104 cells: Implication for neuroplasticity

The sigma-1 receptor (Sig-1R) can bind psychostimulants and was shown to be up-regulated in the brain of methamphetamine self-administering rats. Up-regulation of Sig-1Rs has been implicated in neuroplasticity. However, the mechanism(s) whereby Sig-1Rs are up-regulated by psychostimulants is unknown. Here, we employed a neuroblastoma cell line B-104, devoid of dopamine receptors and transporter, and examined the effects of psychostimulants as well as cAMP on the expression of Sig-1Rs in this cell line, with a specific goal to identify signal transduction pathway(s) that may regulate Sig-1R expression. Chronic treatments of B-104 cells with physiological concentrations of cocaine or methamphetamine failed to alter the expression of Sig-1Rs. N6,2'-O-Dibutyryl-cAMP (dB-cAMP), when used at 0.5 mM, caused a down-regulation of Sig-1Rs that could be blocked by a protein kinase A (PKA) inhibitor, N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide dihydrochloride (H-89). However, dB-cAMP, when used at 2 mM, caused an up-regulation of Sig-1Rs that was insensitive to the H-89 blockade but was partially blocked by an extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase inhibitor PD98059 (2'-amino-3'-methoxyflavone). Furthermore, 2 mM dB-cAMP induced an ERK phosphorylation lasting at least 90 min, at which time the phosphorylation caused by 0.5 mM dB-cAMP had already diminished. PD98059, applied 90 min after addition of 2 mM dB-cAMP, attenuated the Sig-1R up-regulation. Our results indicate that cAMP is bimodal in regulating Sig-1R expression: a down-regulation via PKA and an up-regulation via ERK. Results also suggest that psychostimulants may manipulate the cAMP-PKA-Sig-1R and/or the cAMP-ERK-Sig-1R pathways to achieve a neuroplasticity that favors addictive behaviors.     

Middle-preserving pancreatectomy with reversed pancreaticogastrostomy: report of a case

Parenchyma-sparing pancreatic resections have been reported increasingly in recent years; however, for multifocal diseases involving the head and the tail of the pancreas, total pancreatectomy is still the preferred procedure. The possible consequence of this procedure is loss of normal pancreatic parenchyma, resulting in insufficiency of pancreatic exocrine and endocrine functions. Various types of limited resection have been introduced for isolated or multiple pancreatic lesions, depending on the location of the tumor. Even for multifocal diseases, if the pancreatic body is spared, a middle-preserving pancreatectomy (MPP) can be performed to assure maximal pancreatic function and uncompromised quality of life. Yet, few papers have introduced the feasibility of MPP for a better outcome. This report describes a new surgical technique for MPP using an alternative approach for the remnant pancreas anastomosis. We used this technique successfully to remove a bifocal neoplasm: adenocarcinoma of the distal bile duct and mucinous cyst adenoma in the tail of the pancreas.     

Interaction of magnesium oxide with gastric acid secretion inhibitors in clinical pharmacotherapy

Purpose

Magnesium oxide (MgO), a short-term osmotic laxative, is converted into MgCl₂ under acidic condition in the stomach and then Mg(HCO₃)₂ in the intestinal tract, where Mg(HCO₃)₂ induces the water exudation into the intestine. This indicates that the laxative effect of MgO could be attenuated under the suppressed gastric acid secretion. In this study, the possible interaction of MgO with gastric acid secretion inhibitors was evaluated by using electronic patient records of MgO dosage levels.

Methods

Defecation was controlled with MgO alone in some patients after colon surgery (n?=?67) and after total gastric resection (n?=?4). Some other patients were treated with a combination use of MgO and H₂ receptor antagonist (H₂RA) (n?=?14) or proton pump inhibitor (PPI) (n?=?27). The possible drug interaction of MgO with H₂RA or PPI was evaluated by comparing dosage levels of MgO used in controlling defecation.

Results

In controlling defecation, the daily dosage levels of MgO in patients taking H₂RA or PPI and patients with total gastric resection were significantly higher than those patients taking MgO alone after colon surgery. The ratios of good constipation control (controlled well at the dosing level of 1,000 mg MgO) in patients taking H₂RA or PPI were significantly lower than that in patients treated with MgO alone. In an in vitro study, the solubility of MgO at pH 4.5 was quite low, as compared with that at pH 1.2.

Conclusions

When patients received H₂RA or PPI, the laxative effect of MgO is decreased possibly due to the low solubility of MgO at the higher gastric pH and less generation of MgCl₂ and Mg(HCO₃)₂. Higher dosing level of MgO or another laxative should be used in patients taking H₂RA or PPI, as well as the case of patients with total gastric resection.