Comparing the efficacy of therapeutic Thai acupressure on plantar acupoints and laser cane therapy on freezing of gait in Parkinson's disease: a randomized non-inferiority trial

Background

ON-freezing of gait (ON-FOG) in Parkinson's disease (PD), often resistant to medication, is linked to sensory deficits and proprioceptive impairment, and results in falls and reduced life quality. While visual cues from a laser cane (LC), which rapidly accesses the motor cortex, are commonly used to compensate for proprioceptive impairment, increased visual reliance may be affected by disease progression. Emerging evidence suggests that modulation of peripheral sensory processing may alleviate ON-FOG, and therapeutic Thai acupressure (TTA) may be a solution. This study aims to evaluate the effect of TTA in alleviating ON-FOG and compare its effectiveness to LC in patients with PD.

Methods

This open-label, non-inferiority trial randomized 90 PD patients with ON-FOG equally into three arms: TTA for plantar nerve stimulation for 96 s, LC for visual cueing, and sham control (SC). Stride length was the primary non-inferiority endpoint [non-inferiority margin: lower limit of 95% confidence interval (CI) above -10 cm in mean change difference in pre- and immediately post-intervention in TTA versus LC (one-sided)]. Secondary outcomes included FOG episodes, double support time, velocity, cadence, step length, timed up and go (TUG) test, and visual analog scale (VAS) score.

Results

TTA showed non-inferiority to LC in stride length (mean = -0.7 cm; 95% CI: -6.55; 5.15) (one-sided). The improvements with TTA and LC versus SC were comparable between (mean = 13.11 cm; 95% CI: 7.26; 18.96) and (mean = 13.8 cm; 95% CI: 7.96; 19.65) (one-sided). Secondary outcomes favored TTA and LC over SC with improved FOG, velocity, step length, and VAS scores, while only TTA resulted in improved double support time, cadence, and TUG test results. No complications occurred.

Conclusion

The efficacy of TTA, which improves stride length, is non-inferior to that of LC and consequently alleviates FOG comparable to LC. TTA might enhance proprioceptive function and reduce visual dependence. Therefore, TTA, characterized by its non-invasive, simple, and safe techniques, is a potential non-pharmacological alternative for ON-FOG treatment and might enhance overall quality of life. However, further research into the mechanism, efficacy, and utilization of TTA is essential.

Clinical trial registration

https://www.thaiclinicaltrials.org/show/TCTR20200317001, identifier TCTR20200317001.

Identification of Lacrimal Gland Postganglionic Innervation and Its Regulation of Tear Secretion

Tear fluid secreted from the exocrine lacrimal gland (LG) has an essential role in maintaining a homeostatic environment for a healthy ocular surface. Tear secretion is regulated by the sympathetic and parasympathetic components of the autonomic nervous system, although the contribution of each component is not fully understood. To investigate LG innervation, we identified sympathetic and parasympathetic postganglionic nerves, specifically innervating the mouse LG, by injecting a retrograde neuronal tracer into the LG. Interruption of neural stimuli to the LG by the denervation of these postganglionic nerves immediately and chronically decreased tear secretion, leading to LG atrophy along with destruction of the lobular structure. This investigation also found that parasympathetic, but not sympathetic, innervation was involved in these alterations.

Spatiotemporal dynamics of red blood cells in capillaries in layer I of the cerebral cortex and changes in arterial diameter during cortical spreading depression and response to hypercapnia in anesthetized mice

OBJECTIVE

Control of red blood cell velocity in capillaries is essential to meet local neuronal metabolic requirements, although changes of capillary diameter are limited. To further understand the microcirculatory response during cortical spreading depression, we analyzed the spatiotemporal changes of red blood cell velocity in intraparenchymal capillaries.

METHODS

In urethane-anesthetized Tie2-green fluorescent protein transgenic mice, the velocity of fluorescence-labeled red blood cells flowing in capillaries in layer I of the cerebral cortex was automatically measured with our Matlab domain software (KEIO-IS2) in sequential images obtained with a high-speed camera laser-scanning confocal fluorescence microscope system.

RESULTS

Cortical spreading depression repeatedly increased the red blood cell velocity prior to arterial constriction/dilation. During the first cortical spreading depression, red blood cell velocity significantly decreased, and sluggishly moving or retrograde-moving red blood cells were observed, concomitantly with marked arterial constriction. The velocity subsequently returned to around the basal level, while oligemia after cortical spreading depression with slight vasoconstriction remained. After several passages of cortical spreading depression, hypercapnia-induced increase of red blood cell velocity, regional cerebral blood flow and arterial diameter were all significantly reduced, and the correlations among them became extremely weak.

CONCLUSIONS

Taken together with our previous findings, these simultaneous measurements of red blood cell velocity in multiple capillaries, arterial diameter and regional cerebral blood flow support the idea that red blood cell flow might be altered independently, at least in part, from arterial regulation, that neuro-capillary coupling plays a role in rapidly meeting local neural demand.

Functional interactions between transient receptor potential M8 and transient receptor potential V1 in the trigeminal system: Relevance to migraine pathophysiology

Background

Recent genome-wide association studies have identified transient receptor potential M8 (TRPM8) as a migraine susceptibility gene. TRPM8 is a nonselective cation channel that mediates cool perception. However, its precise role in migraine pathophysiology is elusive. Transient receptor potential V1 (TRPV1) is a nonselective cation channel activated by noxious heat. Both TRPM8 and TRPV1 are expressed in trigeminal ganglion (TG) neurons.

Methods

We investigated the functional roles of TRPM8 and TRPV1 in a meningeal inflammation-based migraine model by measuring the effects of facial TRPM8 activation on thermal allodynia and assessing receptor coexpression changes in TG neurons. We performed retrograde tracer labeling to identify TG neurons innervating the face and dura.

Results

We found that pharmacological TRPM8 activation reversed the meningeal inflammation-induced lowering of the facial heat pain threshold, an effect abolished by genetic ablation of TRPM8. No significant changes in the heat pain threshold were seen in sham-operated animals. Meningeal inflammation caused dynamic alterations in TRPM8/TRPV1 coexpression patterns in TG neurons, and colocalization was most pronounced when the ameliorating effect of TRPM8 activation on thermal allodynia was maximal. Our tracer assay disclosed the presence of dura-innervating TG neurons sending collaterals to the face. Approximately half of them were TRPV1-positive. We also demonstrated functional inhibition of TRPV1 by TRPM8 in a cell-based assay using c-Jun N-terminal kinase phosphorylation as a surrogate marker.

Conclusions

Our findings provide a plausible mechanism to explain how facial TRPM8 activation can relieve migraine by suppressing TRPV1 activity. Facial TRPM8 appears to be a promising therapeutic target for migraine.

High-mobility group box 1 is an important mediator of microglial activation induced by cortical spreading depression

Single episodes of cortical spreading depression (CSD) are believed to cause typical migraine aura, whereas clusters of spreading depolarizations have been observed in cerebral ischemia and subarachnoid hemorrhage. We recently demonstrated that the release of high-mobility group box 1 (HMGB1) from cortical neurons after CSD in a rodent model is dependent on the number of CSD episodes, such that only multiple CSD episodes can induce significant HMGB1 release. Here, we report that only multiple CSD inductions caused microglial hypertrophy (activation) accompanied by a greater impact on the transcription activity of the HMGB1 receptor genes, TLR2 and TLR4, while the total number of cortical microglia was not affected. Both an HMGB1-neurtalizing antibody and the HMGB1 inhibitor glycyrrhizin abrogated multiple CSD-induced microglial hypertrophy. Moreover, multiple CSD inductions failed to induce microglial hypertrophy in TLR2/4 double knockout mice. These results strongly implicate the HMGB1-TLR2/4 axis in the activation of microglia following multiple CSD inductions. Increased expression of the lysosomal acid hydrolase cathepsin D was detected in activated microglia by immunostaining, suggesting that lysosomal phagocytic activity may be enhanced in multiple CSD-activated microglia.

Dynamic diameter response of intraparenchymal penetrating arteries during cortical spreading depression and elimination of vasoreactivity to hypercapnia in anesthetized mice

Cortical spreading depression (CSD) induces marked hyperemia with a transient decrease of regional cerebral blood flow (rCBF), followed by sustained oligemia. To further understand the microcirculatory mechanisms associated with CSD, we examined the temporal changes of diameter of intraparenchymal penetrating arteries during CSD. In urethane-anesthetized mice, the diameter of single penetrating arteries at three depths was measured using two-photon microscopy during passage of repeated CSD, with continuous recordings of direct current potential and rCBF. The first CSD elicited marked constriction superimposed on the upstrokes of profound dilation throughout each depth of the penetrating artery, and the vasoreaction temporally corresponded to the change of rCBF. Second or later CSD elicited marked dilation with little or no constriction phase throughout each depth, and the vasodilation also temporally corresponded to the increase of rCBF. Furthermore, the peak dilation showed good negative correlations with basal diameter and increase of rCBF. Vasodilation induced by 5% CO2 inhalation was significantly suppressed after CSD passage at any depth as well as hyperperfusion. These results may indicate that CSD-induced rCBF changes mainly reflect the diametric changes of the intraparenchymal arteries, despite the elimination of responsiveness to hypercapnia.

Purified Human Dental Pulp Stem Cells Promote Osteogenic Regeneration

Human dental pulp stem/progenitor cells (hDPSCs) are attractive candidates for regenerative therapy because they can be easily expanded to generate colony-forming unit-fibroblasts (CFU-Fs) on plastic and the large cell numbers required for transplantation. However, isolation based on adherence to plastic inevitably changes the surface marker expression and biological properties of the cells. Consequently, little is currently known about the original phenotypes of tissue precursor cells that give rise to plastic-adherent CFU-Fs. To better understand the in vivo functions and translational therapeutic potential of hDPSCs and other stem cells, selective cell markers must be identified in the progenitor cells. Here, we identified a dental pulp tissue-specific cell population based on the expression profiles of 2 cell-surface markers LNGFR (CD271) and THY-1 (CD90). Prospectively isolated, dental pulp-derived LNGFR(Low+)THY-1(High+) cells represent a highly enriched population of clonogenic cells--notably, the isolated cells exhibited long-term proliferation and multilineage differentiation potential in vitro. The cells also expressed known mesenchymal cell markers and promoted new bone formation to heal critical-size calvarial defects in vivo. These findings suggest that LNGFR(Low+)THY-1(High+) dental pulp-derived cells provide an excellent source of material for bone regenerative strategies.

Unveiling astrocytic control of cerebral blood flow with optogenetics

Cortical neural activities lead to changes in the cerebral blood flow (CBF), which involves astrocytic control of cerebrovascular tone. However, the manner in which astrocytic activity specifically leads to vasodilation or vasoconstriction is difficult to determine. Here, cortical astrocytes genetically expressing a light-sensitive cation channel, channelrhodopsin-2 (ChR2), were transcranially activated with a blue laser while the spatiotemporal changes in CBF were noninvasively monitored with laser speckle flowgraphy in the anesthetised mouse cortex. A brief photostimulation induced a fast transient increase in CBF. The average response onset time was 0.7 ± 0.7 sec at the activation foci, and this CBF increase spread widely from the irradiation spot with an apparent propagation speed of 0.8–1.1 mm/sec. The broad increase in the CBF could be due to a propagation of diffusible vasoactive signals derived from the stimulated astrocytes. Pharmacological manipulation showed that topical administration of a K⁺ channel inhibitor (BaCl₂; 0.1–0.5 mM) significantly reduced the photostimulation-induced CBF responses, which indicates that the ChR2-evoked astrocytic activity involves K⁺ signalling to the vascular smooth muscle cells. These findings demonstrate a unique model for exploring the role of the astrocytes in gliovascular coupling using non-invasive, time-controlled, cell-type specific perturbations.

Temporal profiles of high-mobility group box 1 expression levels after cortical spreading depression in mice

INTRODUCTION

Cortical spreading depression (CSD) has recently been shown to induce the release of the nuclear protein termed high-mobility group box 1 from neurons, causing activation of the trigeminovascular system. Here, we explored the effects of single and multiple cortical spreading depression inductions on high-mobility group box 1 (HMGB1) transcriptional activity relative to high-mobility group box 1 protein expression levels and intracellular localization in cortical neurons and astrocytes.

METHODS

Single or multiple cortical spreading depression inductions were achieved by KCl application to the mouse cerebral cortex. The animals were sacrificed at 30 minutes, 3 hours and 24 hours after cortical spreading depression induction. High-mobility group box 1 expression levels were explored with in situ hybridization, Western blotting and immunostaining.

RESULTS

Cortical spreading depression up-regulated high-mobility group box 1 transcriptional activity in neurons at 3 hours in a manner that was dependent on the number of cortical spreading depression inductions. At 24 hours, the high-mobility group box 1 transcriptional activity had returned to basal levels. Cortical spreading depression induced a reduction in high-mobility group box 1 protein expression at 3 hours, which was also dependent on the number of cortical spreading depression inductions. Following cortical spreading depression, the release of high-mobility group box 1 from the nucleus was observed in a small proportion of neurons, but not in astrocytes.

CONCLUSION

Cortical spreading depression induced translocation of high-mobility group box 1 from neuronal nuclei, driving transcriptional up-regulation of high-mobility group box 1 to maintain protein levels.

Hyperperfusion counteracted by transient rapid vasoconstriction followed by long-lasting oligemia induced by cortical spreading depression in anesthetized mice

Cortical spreading depression (CSD) involves mass depolarization of neurons and glial cells accompanied with changes in regional cerebral blood flow (rCBF) and energy metabolism. To further understand the mechanisms of CBF response, we examined the temporal diametric changes in pial arteries, pial veins, and cortical capillaries. In urethane-anesthetized mice, the diameters of these vessels were measured while simultaneously recording rCBF with a laser Doppler flowmeter. We observed a considerable increase in rCBF during depolarization in CSD induced by application of KCl, accompanied by a transient dip of rCBF with marked vasoconstriction of pial arteries, which resembled the response to pin-prick-induced CSD. Arterial constriction diminished or disappeared during the second and third passages of CSD, whereas the rCBF increase was maintained without a transient dip. Long-lasting oligemia with a decrease in the reciprocal of mean transit time of injected dye and mild constriction of pial arteries was observed after several passages of the CSD wave. These results indicate that CSD-induced rCBF changes consist of initial hyperemia with a transient dip and followed by a long-lasting oligemia, partially corresponding to the diametric changes of pial arteries, and further suggest that vessels other than pial arteries, such as intracortical vessels, are involved.

Microvascular sprouting, extension, and creation of new capillary connections with adaptation of the neighboring astrocytes in adult mouse cortex under chronic hypoxia

The present study aimed to determine the spatiotemporal dynamics of microvascular and astrocytic adaptation during hypoxia-induced cerebral angiogenesis. Adult C57BL/6J and Tie2-green fluorescent protein (GFP) mice with vascular endothelial cells expressing GFP were exposed to normobaric hypoxia for 3 weeks, whereas the three-dimensional microvessels and astrocytes were imaged repeatedly using two-photon microscopy. After 7 to 14 days of hypoxia, a vessel sprout appeared from the capillaries with a bump-like head shape (mean diameter 14 μm), and stagnant blood cells were seen inside the sprout. However, no detectable changes in the astrocyte morphology were observed for this early phase of the hypoxia adaptation. More than 50% of the sprouts emerged from capillaries 60 μm away from the center penetrating arteries, which indicates that the capillary distant from the penetrating arteries is a favored site for sprouting. After 14 to 21 days of hypoxia, the sprouting vessels created a new connection with an existing capillary. In this phase, the shape of the new vessel and its blood flow were normalized, and the outside of the vessels were wrapped with numerous processes from the neighboring astrocytes. The findings indicate that hypoxia-induced cerebral angiogenesis provokes the adaptation of neighboring astrocytes, which may stabilize the blood-brain barrier in immature vessels.

Activation of extracellular signal-regulated kinase in the trigeminal ganglion following both treatment of the dura mater with capsaicin and cortical spreading depression

Extracellular signal-regulated kinase (ERK) is known to be phosphorylated after exposure to noxious stimuli. In this study, we investigated the response in the dura mater to nociceptive stimulation, which is thought to be responsible for the pathogenesis of headaches, including migraines. We also examined the level of ERK phosphorylation in the trigeminal ganglion following cortical spreading depression (CSD), which is thought to play an important role in migraine pathophysiology. Western blot and immunohistochemical analyses showed a significant increase in the ERK phosphorylation levels 3 min following an application of 10mM capsaicin to the dura mater. This increase was inhibited after an application of the TRPV1 antagonist capsazepine or a MEK inhibitor. An immunohistochemical analysis revealed that most of the small-sized trigeminal ganglion neurons with TRPV1-immunoreactivity that innervate the dura mater exhibited pERK-immunoreactivity, suggesting that these neurons had responded to nociceptive stimulation. CSD increased the level of ERK phosphorylation 30 min after its elicitation, and this response was inhibited by a prior intraventricular administration of TRPV1 antagonist. These results indicate that CSD can activate dural TRPV1 to send nociceptive signals to the trigeminal system, and they provide important clues regarding the relationship between CSD and the trigeminovascular system.

Differential cellular localization of antioxidant enzymes in the trigeminal ganglion

Because of its high oxygen demands, neural tissue is predisposed to oxidative stress. Here, our aim was to clarify the cellular localization of antioxidant enzymes in the trigeminal ganglion. We found that the transcriptional factor Sox10 is localized exclusively in satellite glial cells (SGCs) in the adult trigeminal ganglion. The use of transgenic mice that express the fluorescent protein Venus under the Sox10 promoter enabled us to distinguish between neurons and SGCs. Although both superoxide dismutases 1 and 2 were present in the neurons, only superoxide dismutase 1 was identified in SGCs. The enzymes relevant to hydrogen peroxide degradation displayed differential cellular localization, such that neurons were endowed with glutathione peroxidase 1 and thioredoxin 2, and catalase and thioredoxin 2 were present in SGCs. Our immunohistochemical finding showed that only SGCs were labeled by the oxidative damage marker 8-hydroxy-2'-deoxyguanosine, which indicates that the antioxidant systems of SGCs were less potent. The transient receptor potential vanilloid subfamily member 1 (TRPV1), the capsaicin receptor, is implicated in inflammatory hyperalgesia, and we demonstrated that topical capsaicin application causes short-lasting mechanical hyperalgesia in the face. Our cell-based assay revealed that TRPV1 agonist stimulation in the presence of TRPV1 overexpression caused reactive oxygen species-mediated caspase-3 activation. Moreover, capsaicin induced the cellular demise of primary TRPV1-positive trigeminal ganglion neurons in a dose-dependent manner, and this effect was inhibited by a free radical scavenger and a pancaspase inhibitor. This study delineates the localization of antioxidative stress-related enzymes in the trigeminal ganglion and reveals the importance of the pivotal role of reactive oxygen species in the TRPV1-mediated caspase-dependent cell death of trigeminal ganglion neurons. Therapeutic measures for antioxidative stress should be taken to prevent damage to trigeminal primary sensory neurons in inflammatory pain disorders.

Suppressive effect of chronic peroral topiramate on potassium-induced cortical spreading depression in rats

OBJECTIVE

To evaluate the chronic effect of topiramate (TPM) on cortical spreading depression (CSD), which is thought to be related to migraine aura.

METHODS

Male rats (n = 30) were randomized to once-daily peroral treatment with TPM (50, 100, 200 or 600 mg/kg) or vehicle for 6 weeks. We evaluated the characteristics of CSD induced by topical application of KCl under isoflurane anesthesia and the changes in plasma level of TPM in each group. The effect of single administration of TPM on CSD was also evaluated.

RESULTS

After the final administration of TPM, when the plasma level of TPM was high, KCl-induced CSD frequency and CSD propagation velocity were dose-dependently reduced and the interval between CSD episodes was elongated, compared with the vehicle control. However, before the final administration of TPM, when the plasma level was very low, the KCl-induced CSD profile was the same as that in the vehicle control. Single administration of TPM did not alter the CSD profile. Local cerebral blood flow was not significantly altered by chronic administration of TPM.

CONCLUSION

TPM suppressed the frequency and propagation of CSD along the cerebral cortex, and might be a candidate for relief of migraine.

Repeated longitudinal in vivo imaging of neuro-glio-vascular unit at the peripheral boundary of ischemia in mouse cerebral cortex

Understanding the cellular events evoked at the peripheral boundary of cerebral ischemia is critical for therapeutic outcome against the insult of cerebral ischemia. The present study reports a repeated longitudinal imaging for cellular-scale changes of neuro-glia-vascular unit at the boundary of cerebral ischemia in mouse cerebral cortex in vivo. Two-photon microscopy was used to trace the longitudinal changes of cortical microvasculature and astroglia following permanent middle cerebral artery occlusion (MCAO). We found that sulforhodamine 101 (SR101), a previously-known marker of astroglia, provide a bright signal in the vessels soon after the intraperitoneal injection, and that intensity was sufficient to detect the microvasculature up to a depth of 0.8 mm. After 5-8 h from the injection of SR101, cortical astroglia was also imaged up to a depth of 0.4 mm. After 1 day from MCAO, some microvessels showed a closure of the lumen space in the occluded MCA territory, leading to a restructuring of microvascular networks up to 7 days after MCAO. At the regions of the distorted microvasculature, an increase in the number of cells labeled with SR101 was detected, which was found as due to labeled neurons. Immunohistochemical results further showed that ischemia provokes neuronal uptake of SR101, which delineate a boundary between dying and surviving cells at the peripheral zone of ischemia in vivo. Finally, reproducibility of the MCAO model was evaluated with magnetic resonance imaging (MRI) in a different animal group, which showed the consistent infarct volume at the MCA territory over the subjects.

Capillary remodeling and collateral growth without angiogenesis after unilateral common carotid artery occlusion in mice

OBJECTIVE

To clarify the mechanisms of blood flow restoration after major artery occlusion, we presented first dynamic changes in cortical vessel morphology observed through a cranial window in mice after unilateral common carotid artery (CCA) occlusion.

METHODS

The density and diameter of capillaries, as well as diameters of pial arteries, were measured by confocal laser-scanning microscopy and fluorescent microscopy, respectively. Possible angiogenesis was evaluated by detecting any outgrowth of endothelial cells from pre-existing vessels or intussusception in Tie2-GFP mice.

RESULTS

Immediately after unilateral CCA occlusion, cerebral blood flow (CBF) index, the reciprocal of mean transit time, reduced significantly and returned to the previous level after 14 days. Repeated observation of the cortical vessels did not reveal any angiogenesis, whereas the cortical capillary diameter increased by 74% after 14 days. The anterior cerebral artery (ACA) and collateral vessels connecting ACA and middle cerebral artery also dilated significantly. The capillary dilatation to the size of arteriole in the settings of collateral growth and CBF restoration suggested capillary remodeling.

CONCLUSIONS

Our results indicate that capillary remodeling, pial artery dilatation and collateral growth without angiogenesis are sufficient mechanisms to restore normal cerebral blood flow after unilateral CCA occlusion.

Developmental and circulatory profile of the diploic veins

To examine the development of the diploic veins in the calvarium, FITC-dextran was injected into the tail vein. The total area of the diploic veins showed a continuous, age-dependent development. We also measured the red blood cell (RBC) velocities in the diploic veins using an in vivo imaging technique and revealed RBCs with a significantly high velocity and unidirectional characteristics at the entrance route. The route passed from the basal periosteum of the cranial bone via the dura mater and into the diploic veins. Our findings indicate the existence of communications between intra- and extra-cranial circulation.

Resident endothelial cells surrounding damaged arterial endothelium reendothelialize the lesion

OBJECTIVE

To evaluate endothelial repair processes in denuded pial vessels to clarify mechanisms for reconstructing endothelium (because endothelial repair of the cerebral artery after its damage is critical for the prevention of thrombosis, the maintenance of vascular tone, and the protection of the brain by the blood-brain barrier).

METHODS AND RESULTS

Endothelial cells (ECs) in a 350-microm-long segment of the middle cerebral artery were damaged through a photochemical reaction. Tie2-green fluorescent protein transgenic mice were used for the identification of ECs. Six hours after the endothelial damage, ECs were detached from the luminal surface of the damaged artery, which was then covered with a platelet carpet. Within 24 hours, recovery of the denuded artery started at both edges, with EC elongation and migration. The repair rate was faster at the proximal edge than at the distal edge. Reendothelialization with EC proliferation peaked at 2 to 3 days and ended at 5 days, together with normalization of EC length, with no apparent involvement of foreign progenitor cells.

CONCLUSIONS

Our in vivo study demonstrated a stepwise reendothelialization process by resident ECs of the pial artery. The prevention of thrombosis, vasospasm, and treatment for blood-brain barrier dysfunction should be considered during the reendothelialization period.

RBC velocities in single capillaries of mouse and rat brains are the same, despite 10-fold difference in body size

Employing high-speed camera laser-scanning confocal microscopy with RBC-tracking software, we previously showed that RBC velocities in intraparenchymal capillaries of rat cerebral cortex are distributed over a wide range. In the present work, we measured RBC velocities in mice, whose body weights are less than one-tenth of that of rats. In an isoflurane-anesthetized mouse, a cranial window was opened in the left temporo-parietal region. Intravenously administered FITC-labeled RBCs were automatically recognized and tracked frame-by-frame at 500fps, and the velocities of all RBCs recognized were calculated with our Matlab-domain software, KEIO-IS2. Among 15241 RBCs detected in the ROI in 21 mice, 1655 were identified as flowing in capillaries. The velocities of these RBCs ranged from 0.15 to 8.6mm/s, with a mean of 2.03+/-1.42mm/s. A frequency distribution plot showed that RBC velocities were clustered at around 1.0mm/s, tailing up to 8.6mm/s, and 59% of the RBCs in capillaries showed velocities within the range of 0.5 to 2.0mm/s. Unexpectedly, these characteristics of RBC velocities in mice were very similar to those of rats, despite differences in RBC diameter (6.0 vs. 6.5microm), body size (25 vs. 327g), heart rate (461 vs. 319bpm) and arterial blood pressure (86 vs. 84mmHg). We speculate that physical factors relating to oxygen exchange may constrain general RBC velocity in capillaries to a certain range for optimum oxygen exchange, regardless of species.

Distribution and origin of TRPV1 receptor-containing nerve fibers in the dura mater of rat

We examined the distribution and origin of the nerve fibers innervating the dura mater of the rat that show immunoreactivity for the TRPV1 receptor (TRPV1-IR). Nearly 70% of the nerve fibers showing TRPV1-IR in the dura mater also exhibited CGRP-IR. Using a combination of immunohistochemistry and a retrograde tracer technique, we detected tracer accumulation in 0.6% of the neurons in the trigeminal ganglion and a few neurons in the dorsal root ganglion; half of the neurons in the trigeminal ganglion were small- and medium-sized (<or=1000 microm2). Among the tracer-accumulated neurons in the trigeminal ganglion, approximately 25% exhibited TRPV1-IR. Furthermore, nearly 80% of the tracer-accumulated small- and medium-sized neurons in the trigeminal ganglion that exhibited TRPV1-IR also exhibited CGRP-IR. Our findings indicate that the TRPV1 receptor in the dura mater and sensory ganglia may contribute to the pathophysiology of migraine, providing an important clue for the development of therapeutic strategies for migraine.

Ultrastructural study of upper surface layer in rat articular cartilage by "in vivo cryotechnique" combined with various treatments

The ultrastructures of the upper surface layer of rat articular cartilage were studied with our "in vivo cryotechnique" followed by freeze-substitution method for scanning electron microscopy (SEM) or transmission electron microscopy (TEM). Rat hip or knee articular cartilage was quickly frozen by the in vivo cryotechnique with liquid isopentane-propane cryogen (-193 degrees C), and surface areas of some frozen specimens were freeze-fractured with a scalpel in liquid nitrogen. They were freeze-substituted and freeze-dried, ion-sputtered, and then observed in SEM. Other frozen specimens were routinely freeze-substituted and embedded in epoxy resin for TEM. Many globular structures were detected in the thick upper surface layer that had not been revealed by the conventional fixation methods. Their sizes were reduced by Triton X-100 treatment, and their localization was also detected in synovial fluid, as revealed by SEM. Such globular lipid-like structures in the upper surface layer of hip or knee articular cartilage might contribute to joint lubrication.

Postoperative nerve conduction changes after open and endoscopic carpal tunnel release

OBJECTIVE

To assess the improvement of motor distal latency (MDL), sensory nerve conduction velocity (SCV) of the median nerve and the amplitudes of compound muscle action potential (CMAP) and sensory nerve action potential (SNAP) in patients with idiopathic carpal tunnel syndrome subjected to surgical treatment according to the open carpal tunnel release method and the endoscopic carpal tunnel release.

METHODS

Sixty-six hands of sixty-six patients were divided into two groups: the ECTR group and the OCTR group. The patients were evaluated preoperatively, and at 1, 3, 6, and 12 months postoperatively.

RESULTS

Although no statistically significant difference of the recovery of MDL and the amplitude of CMAP and SNAP was detected between the two groups at any time point during follow-up, one patient in the ECTR group in whom the operation had been converted to OCTR, showed delay of MDL and decrease in the amplitude of CMAP.

CONCLUSIONS

There is a risk of nerve damage in patients undergoing ECTR. Although statistical analysis suggests that nerve conduction improves by about the same degree 12 months after ECTR or OCTR, slightly faster improvement after OCTR cannot be excluded.

Anionic sites in articular cartilage revealed by polyethyleneimine staining

Articular cartilage is a unique tissue that contains neither blood vessels nor nerves, and that performs mechanical loading during joint movement. These properties are endowed by abundant glycosaminoglycans (GAGs), which are capable of retaining water-soluble substances. The GAGs attach to core proteins and form proteoglycans. Although many studies have focused on proteoglycans and collagen fibrils in cartilage, little is known about the nature of the negative charge of GAGs. Recently, we investigated this subject using a cationic dye, polyethyleneimine (PEI), with several different techniques such as pre-embedding, post-embedding, and quick-freezing and deep-etching methods. In addition, we investigated whether the anionic charge is altered at low pH, using PEI and cationic colloidal gold (CCG) labeling. The shapes of PEI-positive structures revealed by the pre-embedding method varied at different pHs. Three-dimensional analysis using the quick-freezing and deep-etching method demonstrated that meshwork structures composed of fine filaments were decorated with tiny PEI granules. Additionally, the meshwork structure was broken down after chondroitinase ABC digestion. These data indicate that the large PEI deposits observed in pre-embedding preparations are, at least in part, artificial images, and that the meshwork structure consists of chondroitin sulfate-retaining anionic sites. Low pH conditions changed PEI or CCG labeling patterns, showing that negative charges of GAGs in articular cartilage are altered under environmental pH conditions. These findings demonstrate that binding capacities of anionic sites to water-soluble or ionic substances are greatly affected by pH alterations without actually decreasing the number of anionic sites. Therefore, to understand cartilage dynamics and the pathogenesis of joint diseases in greater detail, alterations of anionic charge during mechanical loading or under pathological conditions should be examined in future studies.

Longitudinal Median Nerve Conduction Studies After Endoscopic Carpal Tunnel Release

Forty hands of 36 patients who had undergone endoscopic carpal tunnel release (ECTR), utilising Chow's two-portal technique after being diagnosed with idiopathic carpal tunnel syndrome, were subjected to longitudinal median nerve conduction studies. The distal motor latency (DML) was examined pre-operatively on all the hands, which were re-examined at the post-operative 1st, 3rd, 6th and 12th months. Rapid improvement of DML was observed post-operatively in the first three months. These improvements patterns are not much different from those after open carpal tunnel release (OCTR) reported in the literatures. We consider that the data reported herein can be used as standards of DML course after ECTR.

Nucleocapsid formation and/or subsequent conformational change of rabies virus nucleoprotein (N) is a prerequisite step for acquiring the phosphatase-sensitive epitope of monoclonal antibody 5-2-26

We investigated the antigenic maturation of rabies virus N protein, for which we used some conformational epitope-specific monoclonal antibodies (MAbs) and an MAb (5-2-26) against a phosphorylation-dependent linear epitope. Infected cells were lysed with a deoxycholate-free lysis buffer and separated by ultracentrifugation into the soluble top and the nucleocapsid fractions. None of the study MAbs recognized N proteins in the top fraction, whereas nucleocapsid-associated N proteins were recognized by all of the MAbs. Immunoprecipitation with polyclonal anti-N antibodies coprecipitated the P proteins from the top fraction, indicating that soluble N proteins are mostly associated with the P protein. The N proteins dissociated from both the N-P complex and nucleocapsids were recognized by none of the study MAbs, whereas the MAb 5-2-6 recognized the SDS-denatured N proteins of the nucleocapsid but not of the top fraction. In addition, the phosphorylation-deficient mutant N proteins were shown to be similarly accumulated as the wild-type N proteins into the viral inclusion bodies, defined as the virus-specific structures composed of viral nucleocapsids, that are produced in the cytoplasm of the infected cells. Based on these results, we believe that newly synthesized N proteins are not immediately phosphorylated at serine-389 (a common phosphorylation site) but are first associated with the P protein. After being used for encapsidation of the viral RNA, the N proteins undergo conformational changes, whereby epitopes for the conformation-specific MAbs are formed and become phosphorylated at serine-389.

Studies on the rabies virus RNA polymerase: 2. Possible relationships between the two forms of the non-catalytic subunit (P protein)

We investigated the relationship between the two forms of rabies virus P protein, a non-catalytic subunit of rabies virus RNA polymerase. The two displayed different electrophoretic mobilities as 37- and 40-kDa polypeptides, hence termed as p37 and p40, respectively. Double labeling experiments with [3H]leucine and [32P]orthophosphate demonstrated that p40 was much more phosphorylated than p37. Treatment of the virion proteins with alkaline phosphatase eliminated only p40, and not 37-kDa polypeptide. The p37 was a major product of the P gene, and was accumulated in the infected cell and incorporated into the virion. On the other hand, p40 was apparently detected only in the virion, and little detected in the cells. Treatment of infected cells with okadaic acid, however, resulted in significant accumulation of p40 in the cell, suggesting that p40 was continuously produced in the cell but dephosphorylated quickly. We detected both 37- and 40-kDa products in P cDNA-transfected animal cells, while only a 37-kDa product was produced in Escherichia coli. Incubation of 37-kDa products from E. coli with the lysates of animal cells in vitro resulted in the production of a 40-kDa product, which was also shown to be suppressed by the heparin. From these results, it is suggested that p40 is produced by the hyperphosphorylation of a 37-kDa polypeptide, which depends on certain heparin-sensitive cellular enzyme(s) and occurs even in the absence of the other viral gene products, and that p40 is reverted quickly to p37 in the infected cells, probably being dependent on some virus-induced factor(s).

Nontraumatic bilateral first rib fractures

The authors report the case of a 21-year old woman who presented bilateral spontaneous fractures of the first ribs, in the posterior portion on the right side, in the anterior portion on the left side. The pathogenesis of spontaneous fractures of the first rib is discussed.

Utilization of a partially threaded Kirschner wire in the treatment of femoral neck fractures

OBJECTIVE

This report introduces a new type of pin for treatment of femoral neck fractures.

DESIGN

Retrospective analysis.

METHODS

The pin used in this study has a tapered thread in its middle portion to facilitate fixation in the lateral femoral cortex, as well as a simple tip that allows percutaneous pinning without displacement of the reduced position. Between 1978 and 1993, we used our pins on 218 hips in 214 patients, all age sixty years or more. We were able to observe postoperative osteosynthesis in 176 hips (172 patients) during a mean follow-up period of thirty-two months; the incidence of osteosynthesis and local postoperative complications was also charted.

RESULTS

Osteosynthesis was obtained in 153 hips (87 percent); for groups based on Garden's classification, results were as follows: twenty-four of twenty-four hips in type 1, fifteen of sixteen in type 2, sixty-three of seventy-one in type 3, and fifty-one of sixty-five in type 4. Some local postoperative complications were observed, including second fractures at the pin insertion point (three hips), pin penetration of the femoral head (twenty-four hips), and pin slippage (three hips).

CONCLUSION

This pin is effective in the treatment of femoral neck fractures and has the added benefits of being minimally invasive and low in cost.

A histochemical study of anionic sites in the intermediate layer of rat femoral cartilage using polyethyleneimine at different pH levels

Anionic sites in the intermediate layer of young rat hyaline cartilages were examined using a cationic dye, polyethyleneimine (PEI), at different pH levels. Femoral heads were resected and fixed in 2.5% glutaraldehyde and treated with 0.5% PEI at pH 7.4, pH 2.5 or pH 1.0. Some cartilage samples were first digested with chondroitinase ABC or hyaluronidase. The PEI deposits at pH 7.4 appeared to be irregular shapes. Their sizes seemed to be larger than those at pH 2.5 or pH 1.0. The PEI deposits were also found on the surface of collagen fibrils at both pH 7.4 and pH 2.5 even after the chondroitinase ABC digestion, but were not found at pH 1.0. Moreover, they disappeared after hyaluronidase digestion. Accordingly, it is suggested that PEI-positive structures varied depending on pH levels. In addition, hyaluronan may be localized near collagen fibrils, but most sulphated proteoglycans may not.

Proteoglycans in articular cartilage revealed with a quick freezing and deep etching method

OBJECTIVES

To clarify the three dimensional ultrastructure of proteoglycans, and their relationship with other matrix components in articular cartilage.

METHODS

Specimens from rat femoral heads were examined using three techniques: (1) Histochemical staining with cationic polyethyleneimine (PEI), using a pre-embedding or a postembedding method. Some tissues were pretreated with chondroitinase ABC or hyaluronidase. (2) Quick freezing and deep etching (QF-DE). Some specimens were fixed with paraformaldehyde and washed in buffer solution before quick freezing; others were frozen directly. (3) Ultrathin sections were studied after conventional preparation.

RESULTS

Proteoglycans were observed as aggregated clumps with PEI staining by the pre-embedding method, but as fine filaments by the postembedding method. They were lost with enzyme digestion; this was also demonstrated by the QF-DE method. The ultrastructure was well preserved by the QF-DE method when fixation and washing procedures were included, but not without these procedures. A fine mesh-like structure was connected to the cell membrane in the pericellular matrix. Filamentous structures suggestive of aggrecans were observed among collagen fibrils. They had side chains, approximately 50 nm in length, which branched from the central filaments at intervals of 10-20 nm, and were occasionally linked to other structures. Many thin filaments were also attached to the collagen fibrils.

CONCLUSIONS

The QF-DE method incorporating paraformaldehyde fixation and buffer washing procedures revealed three dimensional, extended structures suggestive of proteoglycans.

Radiographic factors predicting non-union of displaced intracapsular femoral neck fractures

After 82 patients underwent osteosynthesis with multiple pinning for a displaced intracapsular femoral neck fracture, 58 fractures were united, and 24 were not. These 82 patients were included in a discriminant analysis. Union and non-union groups were the dependent variables. Eleven presumably predictive factors measured on X-ray films obtained from these patients before and immediately after operation were taken as independent variables. Three radiographic factors were selected by a stepwise method according to the effect they had on union. These were: the distance of medial displacement between fragments before reduction; the varus angle after reduction; and the distance of medial displacement between fragments after reduction. The distance of medial displacement between fragments before reduction proved the most important factor in making a choice between osteosynthesis and primary arthroplasty, and it was revealed that osteosynthesis could not be expected to provide union if the distance was 20 mm or more. It was also confirmed that union was promoted, if the cranial fragment was reduced to a valgus position and the medial cortical bones were aligned as much as possible at the time of osteosynthesis.

Efficacy of ivermectin against live mites and eggs of Sarcoptes scabiei in pigs

Sows infested with Sarcoptes scabiei var. suis (ssvs) were treated with 75, 150 and 300 micrograms/kg of ivermectin by a single subcutaneous injection at the neck region. Compared to the numbers of mites and eggs just before injection, those on post treatment weeks (PTW) 1, 2 and 4 showed significant decreases. Especially at 300 micrograms/kg, the counts showed almost all mites and eggs were eradicated on PTW 1, manifesting ivermectin to possess potential effect on ssve without apparent abnormal side effect. Potential mitocide effect of ivermectin on ssvs was revealed.

Effects of smoking on spontaneous and induced sister chromatid exchanges in lymphocytes

Spontaneous and mitomycin C-induced sister chromatid exchanges (SCEs) in lymphocytes were analyzed in 24 non-smokers and 24 sex- and age-matched smokers. Mean spontaneous SCE frequency for non-smokers was 9.8 SCEs/cell, and that for smokers was 11.5 SCEs/cell. The difference was statistically significant (P less than 0.001 by t-test). These results suggest that spontaneous SCE frequency in lymphocytes is useful for evaluation of biological effects of environmental mutagens. However, we could not find any effects of smoking on the sensitivities of lymphocytes to mitomycin C in vitro. The effects of mutagens on humans may be independent of one another.

Home lead-work as a potential source of lead exposure for children

Health examinations for lead poisoning were made on 62 family members from 15 families of homes carrying on lead work, such as quench-hardening in a molten lead bath and type-printing, as work at home. The most interesting findings concern the occurrence of cases with an unduly high lead absorption among children, but not among adult family members other than home lead-workers. The home environments of the children with an unduly high lead absorption represented contamination with housedust high in lead contents. The ingestion of the contaminated housedust by hand-to-mouth is probably responsible for the excessive lead exposure of the affected children. The results of the present study suggest that contamination of housedust with lead due to home lead-work constitutes a possible hazardous source of lead exposure for children.