Clinical utility of urinary mulberry bodies/cells testing in the diagnosis of Fabry disease.

Introduction: Variants in the galactosidase alpha (GLA) gene cause Fabry disease (FD), an X-linked lysosomal storage disorder caused by α-galactosidase A (α-GAL) deficiency. Recently, disease-modifying therapies have been developed, and simple diagnostic biomarkers for FD are required to initiate these therapies in the early stages of the disease. Detection of urinary mulberry bodies and cells (MBs/MCs) is beneficial for diagnosing FD. However, few studies have evaluated the diagnostic accuracy of urinary MBs/MCs in FD. Herein, we retrospectively evaluated the diagnostic ability of urinary MBs/MCs for FD. Methods: We analyzed the medical records of 189 consecutive patients (125 males and 64 females) who underwent MBs/MCs testing. Out of these, two female patients had already been diagnosed with FD at the time of testing, and the remaining 187 patients were suspected of having FD and underwent both GLA gene sequencing and/or α-GalA enzymatic testing. Results: Genetic testing did not confirm the diagnosis in 50 females (26.5%); hence, they were excluded from the evaluation. Two patients were previously diagnosed with FD, and sixteen were newly diagnosed. Among these 18 patients, 15, including two who had already developed HCM at diagnosis, remained undiagnosed until targeted genetic screening of at-risk family members of patients with FD was performed. The accuracy of urinary MBs/MCs testing exhibited a sensitivity of 0.944, specificity of 1, positive predictive value of 1, and negative predictive value of 0.992. Conclusions: MBs/MCs testing is highly accurate in diagnosing FD and should be considered during the initial evaluation prior to genetic testing, particularly in female patients.

Sympathetic modulation of hindlimb muscle contractility is altered in aged rats.

It has recently been demonstrated that reflex excitation of muscle sympathetic nerves triggered by muscle contraction contributes to the maintenance of tetanic force (TF) in rat hindlimb muscles. We hypothesized that this feedback mechanism between the contraction of hindlimb muscles and the lumbar sympathetic nerves declines during aging. In this study, we examined the contribution of sympathetic nerves on skeletal muscle contractility in young adult (4-9 months old, n = 11) and aged (32-36 months old, n = 11) male and female rats. The tibial nerve was electrically stimulated to measure the TF of the triceps surae muscles resulting from motor nerve activation before and after cutting or stimulating (at 5-20 Hz) the lumbar sympathetic trunk (LST). The TF amplitude decreased by cutting the LST in the young and aged groups; however, the magnitude of the decrease in TF following transection of the LST in the aged rats (6.2%) was significantly (P = 0.02) smaller compared with that in the young rats (12.9%). The TF amplitude was increased by LST stimulation at ≥ 5 Hz in the young and ≥ 10 Hz in the aged groups. The overall TF response to LST stimulation was not significantly different between the two groups; however, an increase in muscle tonus resulting from LST stimulation, independent of motor nerve stimulation, was significantly (P = 0.03) greater in aged compared with young rats. The sympathetic contribution to support motor nerve-induced muscle contraction declined, whereas sympathetic-mediated muscle tonus, independent of motor nerve activity, was augmented in aged rats. These changes in sympathetic modulation of hindlimb muscle contractility may underlie the reduction of skeletal muscle strength during voluntary contraction and rigidity of motion during senescence.

Involvement of the basal nucleus of Meynert on regional cerebral cortical vasodilation associated with masticatory muscle activity in rats.

We examined the neural mechanisms for increases in regional cerebral blood flow (rCBF) in the neocortex associated with mastication, focusing on the cortical vasodilative system derived from the nucleus basalis of Meynert (NBM). In pentobarbital-anesthetized rats, parietal cortical rCBF was recorded simultaneously with electromyogram (EMG) of jaw muscles, local field potentials of frontal cortex, multi-unit activity of NBM neurons, and systemic mean arterial pressure (MAP). When spontaneous rhythmic EMG activity was observed with cortical desynchronization, an increase in NBM activity and a marked rCBF increase independent of MAP changes were observed. A similar rCBF increase was elicited by repetitive electrical stimulation of unilateral cortical masticatory areas. The magnitude of rCBF increase was partially attenuated by administration of the GABAergic agonist muscimol into the NBM. The rCBF increase persisted after immobilization with systemic muscle relaxant (vecuronium). rCBF did not change when jaw muscle activity was induced by electrical stimulation of the pyramidal tract. The results suggest that activation of NBM vasodilator neurons contributes at least in part to the rCBF increase associated with masticatory muscle activity, and that the NBM activation is induced by central commands from the motor cortex, independently of feedback from brainstem central pattern generator or contracting muscles.

Thyroxin and calcitonin secretion into thyroid venous blood is regulated by pharyngeal mechanical stimulation in anesthetized rats.

The effects of the pharyngeal non-noxious mechanical stimulation on the secretion of immunoreactive thyroxin (iT4), immunoreactive calcitonin (iCT), and immunoreactive parathyroid hormone (iPTH) into thyroid venous blood were examined in anesthetized rats. Secretion rates of iT4, iCT, and iPTH were calculated from their concentration in thyroid venous plasma and the plasma flow rate. A mechanical stimulation was delivered to the pharynx by a rubber balloon placed on the tongue that was intermittently pushed into the pharyngeal cavity. Pharyngeal stimulation increased iT4 and iCT secretion, but iPTH secretion was unchanged. The secretion responses were abolished by transecting the superior laryngeal nerves (SLNs) bilaterally. The activities of the thyroid parasympathetic efferent nerves and the afferent nerves in the SLN increased significantly during pharyngeal stimulation. These results indicate that pharyngeal mechanical stimulation promotes thyroxin and calcitonin secretion from the thyroid gland by a reflex increase in SLN parasympathetic efferent activity, triggered by excitation of SLN mechanoreceptive afferents.

Age-Related Changes in Neuromodulatory Control of Bladder Micturition Contractions Originating in the Skin.

The brainstem is essential for producing micturition contractions of the urinary bladder. Afferent input from perineal skin evoked by gentle mechanical stimulation inhibits micturition contractions by decreasing both ascending and descending transmissions between the brainstem and spinal cord. Dysfunction of this inhibitory mechanism may be one cause of the increase in the prevalence of overactive bladder in old age. The aim of this study was to examine effect of aging on function of skin afferent fibers that inhibit bladder micturition contractions in rats. We used anesthetized male rats in three different age groups: young adult (4-5 months old), middle aged (6-9 months old), and aged (27-30 months old). The bladder was expanded to produce isovolumetric rhythmic micturition contractions. Skin afferent fibers were activated for 1 min either by electrical stimulation (0.5 ms, 0.2-10 V, 0.1-10 Hz) of the cutaneous branch of the pudendal nerve (CBPN) or by gentle mechanical skin stimulation with an elastomer roller. When skin afferent nerves were activated electrically, micturition contractions were inhibited in a similar manner in all age groups, with long latency inhibition induced by excitation of Aß fibers and short latency inhibition by additional Aδ and C fiber excitation (at 1-10 Hz). On the contrary, when skin afferent nerves were activated mechanically by rolling, latency of inhibition following rolling stimulation was prolonged in aged rats. Single unitary afferent nerve activity of low-threshold mechanoreceptors (LTMs) from the cutaneous nerve was recorded. The discharge rate during rolling was not significantly reduced in Aß units but was much lower in Aδ and C units in aged rats (0.4 and 0.5 Hz, respectively) than in young adult rats (3 and 7 Hz). These results suggest that the neural mechanism that inhibits bladder micturition contractions by skin afferent input is well maintained in old age, but the early inhibition by gentle skin stimulation is decreased because of reduced responses of Aδ- and C-LTMs.

Modulation of Calcitonin, Parathyroid Hormone, and Thyroid Hormone Secretion by Electrical Stimulation of Sympathetic and Parasympathetic Nerves in Anesthetized Rats.

The thyroid and parathyroid glands are dually innervated by sympathetic (cervical sympathetic trunk [CST]) and parasympathetic (superior laryngeal nerve [SLN]) nerve fibers. We examined the effects of electrical stimulation of efferent or afferent nerve fibers innervating the thyroid and parathyroid glands on the secretion of immunoreactive calcitonin (iCT), parathyroid hormone (iPTH), 3,3',5-triiodothyronine (iT3), and thyroxine (iT4) from the thyroid and parathyroid glands. In anesthetized and artificially ventilated rats, thyroid venous blood was collected. The rate of hormone secretion from the glands was calculated from plasma hormone levels, measured by ELISA, and the flow rate of thyroid venous plasma. SLNs or CSTs were stimulated bilaterally with rectangular pulses with a 0.5-ms width. To define the role of unmyelinated nerve fibers (typically efferent), the cut peripheral segments were stimulated at various frequencies (up to 40 Hz) with a supramaximal intensity to excite all nerve fibers. The secretion of iCT, iT3, and iT4 increased during SLN stimulation and decreased during CST stimulation. iPTH secretion increased during CST stimulation, but was not affected by SLN stimulation. To examine the effects of selective stimulation of myelinated nerve fibers (typically afferent) in the SLN, intact SLNs were stimulated with a subthreshold intensity for unmyelinated nerve fibers. iCT, iT3, and iT4 secretion increased during stimulation of intact SLNs at 40 Hz. These results suggest that excitation of myelinated afferents induced by low intensity and high frequency stimulation of intact SLNs promotes secretion of CT and thyroid hormones from the thyroid gland, potentially via reflex activation of parasympathetic efferent nerve fibers in the SLN.

Stimulus frequency-dependent inhibition of micturition contractions of the urinary bladder by electrical stimulation of afferent Aß, Aδ, and C fibers in cutaneous branches of the pudendal nerve.

We aimed to examine the afferent mechanisms for the reflex inhibition of the rhythmic micturition contractions (RMCs) of the urinary bladder induced by stimulation of the perineal skin afferents in urethane-anesthetized rats. Electrical stimulation (pulse duration: 0.5 ms) was applied to the cutaneous branches of the pudendal nerve (CBPN) at frequencies of 0.1, 1, and 10 Hz for 1 min. Nerve fiber groups were defined by recording compound action potentials from CBPN. Activation of only Aß fibers (0.2 V) produced an inhibition of RMCs at 7-11 min after the onset of stimulation (late inhibition), at any tested frequency. Additional activation of Aδ fibers (1 V) produced additional early inhibition (immediately after stimulation) at 1 and 10 Hz. Furthermore, additional activation of C fibers (10 V) at 10 Hz completely stopped RMCs for >10 min. This strong inhibition persisted after local application of capsaicin to the stimulating CBPN. We conclude that activities of Aß, Aδ, and C afferent fibers, without capsaicin-sensitive channels, can contribute to the inhibition of bladder contractions.

Motion of the drawing hand induces a progressive increase in muscle activity of the non-dominant hand in Ramachandran's mirror-box therapy.

OBJECTIVE: To observe the real-time muscle activity of bilateral hands while subjects draw circles under 2 conditions: with and without using Ramachandran's mirror-box. SUBJECTS: A total of 24 healthy volunteers. METHODS: Subjects drew 4 circles sequentially using their dominant hand with the other hand at rest, both with and without looking at a mirror image. Circles were marked by 8 dots on the paper, which subjects connected up to draw the shape. The activity of the bilateral first dorsal interosseus muscles was recorded using surface electromyography. RESULTS: Muscle activity of the dominant hand remained constant during each task. In contrast, muscle activity of the non-dominant hand increased under the condition of watching the image in the mirror, but was low under the non-watching condition. Furthermore, muscle activity of the non-dominant hand increased over the duration of the task. However, wide variation between subjects was observed under the mirror-image condition. CONCLUSION: Increased muscle action potential of the non-dominant hand may be induced by the circle drawing task of the dominant hand during Ramachandran's mirror-box therapy, which supports previous observations of increased brain activity caused by watching a mirror image.

Treatment of melanocytic nevi.

Pigmented nevi are a heterogeneous group of lesions that range from uniquely curable with laser treatment, to partially responsive, to unresponsive or dangerous. This article presents laser and IPL treatment strategies from a clinical perspective for nevi organized by their typical responsiveness. A rationale for surgical excision, laser, and/or medical therapy in individual patients is also presented. Despite significant recent progress, it is clear that much understanding are still lacking about optimal laser treatment for pigmented lesions.