A Collagen-Based Scaffold for Promoting Neural Plasticity in a Rat Model of Spinal Cord Injury.

In spinal cord injury (SCI) therapy, glial scarring formed by activated astrocytes is a primary problem that needs to be solved to enhance axonal regeneration. In this study, we developed and used a collagen scaffold for glial scar replacement to create an appropriate environment in an SCI rat model and determined whether neural plasticity can be manipulated using this approach. We used four experimental groups, as follows: SCI-collagen scaffold, SCI control, normal spinal cord-collagen scaffold, and normal control. The collagen scaffold showed excellent in vitro and in vivo biocompatibility. Immunofluorescence staining revealed increased expression of neurofilament and fibronectin and reduced expression of glial fibrillary acidic protein and anti-chondroitin sulfate in the collagen scaffold-treated SCI rats at 1 and 4 weeks post-implantation compared with that in untreated SCI control. This indicates that the collagen scaffold implantation promoted neuronal survival and axonal growth within the injured site and prevented glial scar formation by controlling astrocyte production for their normal functioning. Our study highlights the feasibility of using the collagen scaffold in SCI repair. The collagen scaffold was found to exert beneficial effects on neuronal activity and may help in manipulating synaptic plasticity, implying its great potential for clinical application in SCI.

Correction to: Osteogenic prospective of deriving human dental stem cells in collagen matrix boost.

The original version of this article unfortunately contained a mistake. The country was incorrect in the authors affiliations. It should read as "ROC". The corrected affiliations are given below.

High correlation between skin color based on CIELAB color space, epidermal melanocyte ratio, and melanocyte melanin content.

BACKGROUND: To treat skin color disorders, such as vitiligo or burns, melanocytes are transplanted for tissue regeneration. However, melanocyte distribution in the human body varies with age and location, making it difficult to select the optimal donor skin to achieve a desired color match. Determining the correlations with the desired skin color measurement based on CIELAB color, epidermal melanocyte numbers, and melanin content of individual melanocytes is critical for clinical application. METHOD: Fifteen foreskin samples from Asian young adults were analyzed for skin color, melanocyte ratio (melanocyte proportion in the epidermis), and melanin concentration. Furthermore, an equation was developed based on CIELAB color with melanocyte ratio, melanin concentration, and the product of melanocyte ratio and melanin concentration. The equation was validated by seeding different ratios of keratinocytes and melanocytes in tissue-engineered skin substitutes, and the degree of fitness in expected skin color was confirmed. RESULTS: Linear regression analysis revealed a significant strong negative correlation (r =  - 0.847, R2 = 0.717) between CIELAB L* value and the product of the epidermal melanocyte ratio and cell-based melanin concentration. Furthermore, the results showed that an optimal skin color match was achieved by the formula. DISCUSSION: We found that L* value was correlated with the value obtained from multiplying the epidermal melanocyte ratio (R) and melanin content (M) and that this correlation was more significant than either L* vs M or L* vs R. This suggests that more accurate prediction of skin color can be achieved by considering both R and M. Therefore, precise skin color match in treating vitiligo or burn patients would be potentially achievable based on extensive collection of skin data from people of Asian descent.

Osteogenic prospective of deriving human dental stem cells in collagen matrix boost.

Stem cells derived from oral tissue represent a highly attractive alternative source for clinical bone regeneration because they can be collected by non-invasive or minimally invasive procedures. Herein, we describe the human dental stem cells (DSCs) deriving from buccal fat pads (BFP), dental pulp (DP) of impacted teeth, and periodontal ligaments (PDL) to obtain BFPSCs, DPSCs, and PDLSCs, respectively. Cells were purified with selected medium and expanded through passages in stem cell culture medium. Purified cells were characterized for stemness by their growth rate, immunostaining, and multilineage differentiation ability. They showed plastic adherence, expression of stemness-specific markers, and multilineage differentiation potential. Immunocytochemistry analysis confirmed that DPSCs had more osteogenic potential than BFSCs and PDLSCs. Calcium-rich deposits, evaluated by von Kossa and Alizarin red staining, showed greater mineralization when DPSCs were cultured on collagen type I matrix than without collagen. Furthermore, DPSC-seeded collagen type I matrix maintained consistent osteogenesis and boosted mineral formation by 1-2 weeks over that in DPSCs cultured without collagen. Radiographic analysis of DPSC-seeded collagen type I matrix transplanted into rat cranial defects showed significant bone regeneration after 8 weeks. These results suggested that the redundant oral tissue can be used as a source of adult multipotent stem cells for clinical bone regeneration. Triple overlay images with biomarkers (red), nuclei (blue) and bright field morphology of DPSCs. The specifically osteo-differentiation shown by osteocalcin (left) expression and lack of sox9 (right) expressed in the images below which were cultured with collagen matrix, contrast with no collagen matrix group above.

Histochemical and functional improvement of adipose-derived stem cell-based tissue-engineered cartilage by hyperbaric oxygen/air treatment in a rabbit articular defect model.

Cartilage is exposed to compression forces during joint loading. Therefore, exogenous stimuli are frequently used in cartilage tissue engineering strategies to enhance chondrocyte differentiation and extracellular matrix (ECM) secretion. In this study, human adipose-derived stem cells were seeded on a gelatin/polycaprolactone scaffold to evaluate the histochemical and functional improvement of tissue-engineered cartilage after hyperbaric oxygen/air treatment in a rabbit articular defect model. Behavior tests showed beneficial effects on weight-bearing and rear leg-supporting capacities after treatment of tissue-engineered cartilage with 2.5 ATA oxygen or air. Moreover, positron emission tomography images and immunohistochemistry staining demonstrated hydroxyapatite formation and increased ECM synthesis, respectively, at the tissue-engineered cartilage graft site after high pressure oxygen/air treatment. Based on these results, we concluded that hyperbaric oxygen and air treatment can improve the quality of tissue-engineered cartilage in vivo by increasing the synthesis of ECM.

siRNA-targeting transforming growth factor-ß type I receptor reduces wound scarring and extracellular matrix deposition of scar tissue.

Hypertrophic scarring is related to persistent activation of transforming growth factor-ß (TGF-ß)/Smad signaling. In the TGF-ß/Smad signaling cascade, the TGF-ß type I receptor (TGFBRI) phosphorylates Smad proteins to induce fibroblast proliferation and extracellular matrix deposition. In this study, we inhibited TGFBRI gene expression via TGFBRI small interfering RNA (siRNA) to reduce fibroblast proliferation and extracellular matrix deposition. Our results demonstrate that downregulating TGFBRI expression in cultured human hypertrophic scar fibroblasts significantly suppressed cell proliferation and reduced type I collagen, type III collagen, fibronectin, and connective tissue growth factor (CTGF) mRNA, and type I collagen and fibronectin protein expression. In addition, we applied TGFBRI siRNA to wound granulation tissue in a rabbit model of hypertrophic scarring. Downregulating TGFBRI expression reduced wound scarring, the extracellular matrix deposition of scar tissue, and decreased CTGF and α-smooth muscle actin mRNA expression in vivo. These results suggest that TGFBRI siRNA could be applied clinically to prevent hypertrophic scarring.

The effects of microenvironment on wound healing by keratinocytes derived from mesenchymal stem cells.

Embryonic stem cells (ESCs) are pluripotent cells that can differentiate into various cell types, including keratinocyte-like cells, within suitable microniches. In this study, we aimed to investigate the effects of culture media, cell coculture, and a tissue-engineering biocomposite on the differentiation of mouse ESCs (MESCs) into keratinocyte-like cells and applied these cells to a surgical skin wound model. MESCs from BALB/c mice (ESC26GJ), which were transfected using pCX-EGFP expressing green fluorescence, were used to track MESC-derived keratinocytes. Weak expression of the keratinocyte early marker Cytokeratin 14 (CK-14) was observed up to 12 days when MESCs were cultured in a keratinocyte culture medium on tissue culture plastic and on a gelatin/collagen/polycaprolactone (GCP) biocomposite. MESCs cocultured with human keratinocyte cells (HKCs) also expressed CK-14, but did not express CK-14 when cocultured with human fibroblast cells (HFCs). Furthermore, CK-14 expression was observed when MESCs were cocultured by seeding HKCs or HFCs on the same or opposite side of the GCP biocomposite. The highest CK-14 expression was observed by seeding MESCs and HKCs on the same side of the GCP composite and with HFCs on the opposite side. To verify the effectiveness of wound healing in vivo, adipose-derived stem cells were applied to treat surgical wounds in nude mice. An obvious epidermis multilayer and better collagen deposition during wound healing were observed, as assessed by Masson staining. This study demonstrated the potential of keratinocyte-like differentiation from mesenchymal stem cells for use in promoting wound closure and skin regeneration.

Adeno-associated virus-mediated human acidic fibroblast growth factor expression promotes functional recovery of spinal cord-contused rats.

BACKGROUND: Following spinal cord injury, the delivery of neurotrophic factors to the injured spinal cord has been shown to promote axonal regeneration and functional recovery. In previous studies, we showed that acidic fibroblast growth factor (aFGF) is a potent neurotrophic factor that promotes the regeneration of axotomized spinal cord or dorsal root ganglion neurones. METHODS: We constructed a recombinant adeno-associated virus (AAV) vector to express human aFGF and evaluated aFGF expression and function in AAV-aFGF-infected PC12 cells. We analyzed AAV-green fluorescent protein (GFP) tropism and AAV-mediated aFGF expression in contused spinal cords. Animals received behavioural testing to evaluate the functional recovery. RESULTS: Overexpression of aFGF was shown in AAV-aFGF-infected PC12 cells in a dose-dependent manner. Concurrently, neurite extension and cell number were significantly increased in AAV-aFGF infected cells. AAV-mediated GFP expression persisted for at least 5 weeks in contused spinal cords, and the most prominently transduced cells were neurones. Contusive injury reduced endogenous aFGF expression in spinal cords. Overexpression of aFGF was demonstrated in AAV-aFGF transduced spinal cords compared to AAV-GFP transduced spinal cords at 3 and 14 days post-injury. Evaluation of motor function revealed that the improvement of AAV-aFGF-treated rats was prominent. Both AAV-aFGF- and recombinant human aFGF-treated rats revealed significantly better recovery at 5 weeks post-injury, compared to vehicle- and AAV-GFP-treated rats. CONCLUSIONS: These data suggest that supplement of aFGF improve the functional recovery of spinal cord-contused rats and that AAV-aFGF-mediated gene transfer could be a clinically feasible therapeutic approach for patients after nervous system injuries.

Gait analysis of spinal cord injured rats after delivery of chondroitinase ABC and adult olfactory mucosa progenitor cell transplantation.

Chondroitin sulfate proteoglycan (CSPG) is a major component of glial scar to restrict axonal regeneration in the lesion site after spinal cord injury (SCI). Chondroitinase ABC (ChABC), a bacteria enzyme, which has been demonstrated to digest the glycosaminoglycan (GAG) side chain of CSPG to promote axonal re-growth across the injured site. Our previous study suggested that long-term delivery of ChABC (1U/ml, injection volume 0.6 microl for one animal) via intrathecal catheter could decrease the inhibitory effect of limiting axonal re-growth after SCI. The functional behavior has been shown to improve following ChABC treatment. Little axons re-grow across the lesion site of the spinal cord but not enough to support axon innervations to targets. In this article, we show that ChABC administration combining olfactory mucosa progenitor cell (OMPC) transplantation can promote axonal re-growth across the lesion site and enhance the consistency of stepping in spinally transected rats. These OMPCs generated NG2(+) cell lineages after transplanting into the spinal cord parenchyma, and OMPCs were found to spread and migrate toward the lesion region of spinal cord. Moreover, the spatial and temporal characteristics of the step cycle in rats that receive a complete spinal cord transaction following continuous ChABC supply and OMPC transplantation. The gait characteristics of treated rats on a treadmill were consistent and approached that of intact rats. In future, the mechanism of restoring the injured spinal cord will be further investigated.

Study on the neuroprotective effect of fluoxetine against MDMA-induced neurotoxicity on the serotonin transporter in rat brain using micro-PET.

3, 4-Methylenedioxymethamphetamine (MDMA, "ecstasy") has toxic effects on serotonergic neurons in the brain. Our aim was to determine whether N,N-dimethyl-2-(2-amino-4-[(18)F]-fluorophenylthio) benzylamine (4-[(18)F]-ADAM; a serotonin transporter imaging agent) and micropositron emission tomography (micro-PET) can be used to examine in vivo the effect of fluoxetine on MDMA-induced loss of serotonin transporters in rat brain. Male Sprague-Dawley rats were injected with fluoxetine [1 dose, 5 mg/kg, subcutaneously (s.c.)] followed by MDMA (twice a day for 4 consecutive days, 10 mg/kg, s.c.). Micro-PET with 4-[(18)F]-ADAM was performed on days 4, 10, 17, 24, and 31. In addition, the time course of occupancy by fluoxetine at 4-[(18)F]-ADAM sites was measured. Specific 4-[(18)F]-ADAM uptake ratios (SURs) were calculated from the micro-PET imaging data for various brain regions. Immunohistochemistry was performed 7 days after the last micro-PET scan. From day 4 to day 31, SURs were markedly decreased (by approximately 55-75% compared to control values) in all brain regions in MDMA-treated rats. The effect of MDMA was markedly attenuated (approximately 30-50%) by fluoxetine. The fluoxetine-induced decrease in uptake in different brain regions was 40-75% at 90-min postinjection, and this decrease returned to baseline values in most brain regions by day 31. The distribution and intensity of serotonin transporter (SERT) immunostaining in the brain paralleled the PET imaging results, suggesting that a single dose of fluoxetine provides long-lasting protection against MDMA-induced loss of SERT and that such neuroprotection is detectable in vivo by 4-[(18)F]-ADAM micro-PET.

Effects of interleukin-15 on neuronal differentiation of neural stem cells.

Interleukin-15 (IL-15) signaling has pleiotropic actions in many cell types during development and has been best studied in cells of immune system lineage, where IL-15 stimulates proliferation of cytotoxic T cells and induces maturation of natural killer cells. A few reports have indicated that IL-15 and the IL-15 receptor are expressed in central nervous system tissues and neuronal cell lines. Because this aspect of IL-15 action is poorly studied, we used cultured rat neural stem cells (NSCs) to study IL-15 signal transduction and activity. Primary cultures of rat NSCs in culture will form neurospheres and will differentiate into neuron, astrocyte, and oligodendrocyte progenitors under permissive conditions. We found by immunofluorescence that the IL-15Ralpha subunit of the IL-15 receptor was expressed in NSCs and differentiating neurons, but not astrocyte or oligodendrocyte progenitors. We also showed that IL-15 treatment reduced MAP-2 protein levels in neurons and could reduce neurite outgrowth in differentiating neurons but did not affect NSC proliferation, and cell proportions and viability of the corresponding lineage cells. In the presence of a STAT3 inhibitor, Stattic, IL-15 no longer reduced MAP-2 protein levels. IL-15 treatment caused STAT3 phosphorylation. Furthermore, using anti-IL-15Ralpha antibody to block IL-15 signaling completely inhibited IL-15-induced phosphorylation of STAT3 and prevented IL-15 from decreasing neurite outgrowth. In conclusion, IL-15 may influence neural cell differentiation through a signal transduction pathway involving IL-15Ralpha and STAT3. This signal transduction modifies MAP-2 protein levels and, consequently, the differentiation of neurons from NSCs, as evidenced by reduced neurite outgrowth.

Dual-isotope single-photon emission computed tomography for dopamine and serotonin transporters in normal and Parkinsonian monkey brains.

INTRODUCTION: Parkinson's disease (PD) affects both dopaminergic and serotonergic systems. In this study, we simultaneously evaluated dopamine and serotonin transporters in primates using dual-isotope single-photon emission computed tomography (SPECT) imaging and compared the results with traditional single-isotope imaging. METHODS: Four healthy and one 6-OHDA-induced PD monkeys were used for this study. SPECT was performed over 4 h after individual or simultaneous injection of [(99m)Tc]TRODAT-1 (a dopamine transporter imaging agent) and [(123)I]ADAM (a serotonin transporter imaging agent). RESULTS: The results showed that the image quality and uptake ratios in different brain regions were comparable between single- and dual-isotope studies. The striatal [(99m)Tc]TRODAT-1 uptake in the PD monkey was markedly lower than that in normal monkeys. The uptake of [(123)I]ADAM in the midbrain of the PD monkey was comparable to that in the normal monkeys, but there were decreased uptakes in the thalamus and striatum of the PD monkey. CONCLUSIONS: Our results suggest that dual-isotope SPECT using [(99m)Tc]TRODAT-1 and [(123)I]ADAM can simultaneously evaluate changes in dopaminergic and serotonergic systems in a PD model.

Validation of 4-[18F]-ADAM as a SERT imaging agent using micro-PET and autoradiography.

Serotonin transporters (SERTs) have been implicated in various neuropsychiatric disorders. We aim to validate 4-[(18)F]-ADAM (N,N-dimethyl-2-(2-amino-4-[(18)F]fluorophenylthio)benzylamine) as a SERT imaging agent in rats using micro-positron emission tomography (micro-PET) and autoradiography. Sixty to ninety min after injecting 4-[(18)F]-ADAM, specific uptake ratios (SURs) were determined by micro-PET measurements in various brain regions of normal control rats. For n=3, the SUR in the midbrain was 4.94+/-0.16, for the hypothalamus it was 4.39+/-0.031 and for the caudate it was 4.18+/-0.53. The retention of 4-[(18)F]-ADAM in the hypothalamus and midbrain regions increased rapidly between 5 to 10 min after injection and declined thereafter. The SURs determined by autoradiography were: 9.31+/-1.41 for the midbrain, 7.15+/-1.45 for the hypothalamus and 5.22+/-1.14 for the caudate putamen. Both micro-PET and autoradiography studies revealed a dose-dependent progressive inhibition of radioligand uptake in the frontal cortex, caudate putamen and hypothalamus in rats treated with 0.01 to 0.25 mg/kg paroxetine. A decrease in 4-[(18)F]-ADAM uptake of approximately 84% was observed in the midbrain of rats pretreated with 0.25 mg/kg paroxetine as compared to controls (4.94+/-0.16 versus 0.80+/-0.17, n=3). Both 5,7-dihydroxytryptamine and p-chloroamphetamine-treated rats showed pronounced reduction in 4-[(18)F]-ADAM binding when compared to normal controls. Rats pretreated with p-chloroamphetamine exhibited significant inhibition of 4-[(18)F]-ADAM uptake in brain regions rich in SERT over a period of four weeks. Thus, 4-[(18)F]-ADAM is a SERT-specific radioligand that may be useful for evaluating neuropsychiatric conditions involving serotonergic dysfunction.

Simultaneous [99mTc]TRODAT-1 and [123I]ADAM brain SPECT in nonhuman primates.

PURPOSE: This study examined the feasibility of simultaneous dopamine and serotonin transporter imaging using [(123)I]ADAM and [(99m)Tc]TRODAT-1 single photon emission computed tomography (SPECT). PROCEDURES: Simultaneous [(123)I]ADAM (185 MBq) and [(99m)Tc]TRODAT-1 (740 MBq) SPECT was performed in three age-matched female Formosan rock monkeys. An asymmetric energy window was used for dual, and symmetric energy windows were used for single-isotope imaging. Oral fluoxetine (20 mg) and intravenous methylphenidate HCl (1 mg/kg) were given 24 h and 10 min, respectively, before dual-isotope SPECT to test imaging specificities of [(123)I]ADAM and [(99m)Tc]TRODAT-1. RESULTS: Comparable image quality and uptake ratios between dual- and single-isotope SPECT scans were found. Dual-isotope SPECT in fluoxetine-pretreated monkeys showed decreased uptake of [(123)I]-ADAM, but not of [(99m)Tc]TRODAT-1. Dual-isotope SPECT in methylphenidate-pretreated monkeys showed decreased [(99m)Tc]TRODAT-1 uptake without affecting [(123)I]-ADAM uptake. CONCLUSION: Simultaneous [(123)I]-ADAM and [(99m)Tc]TRODAT-1 SPECT appears promising in nonhuman primates and may provide a suitable preclinical model with further clinical implications.

Imaging serotonin transporters using [123I]ADAM SPECT in a parkinsonian primate model.

Parkinson's disease (PD) affects multiple neurotransmitter systems. The purpose of this study was to investigate differences in the serotonin transport system between normal and parkinsonian monkeys using 2-([2-([di-methylamino]methyl)phenyl]thio)-5-[(123)I] iodophenyl-amine([(123)I]ADAM), a serotonin transporters (SERT) radioligand. The brain single photon emission computed tomography (SPECT) was performed on two normal and one parkinsonian monkey. The parkinsonian monkey was induced by bilateral injection of 6-hydroxydopamine (6-OHDA) into the medial forebrain bundle under magnetic resonance imaging (MRI) guidance. Each monkey underwent two [(99m)Tc] TRODAT-1 (a dopamine transporters imaging agent) and two [(123)I] ADAM brain SPECT scans. After a bolus injection of the radioligand, the SPECT data were acquired over 4h using a dual-head gamma camera equipped with ultra-high resolution fan-beam collimators. The striatal uptake of [(99m)Tc]TRODAT-1 was 46% lower in the parkinsonian monkey than those of normal monkeys at 210-240 min post-injection. [(123)I]ADAM uptake in the midbrain of the parkinsonian monkey was comparable to those of the controls. The uptakes of [(123)I]ADAM in the striatum, thalamus, and frontal cortex of the parkinsonian monkey, were 31%, 31%, and 23% lower than those of normal monkeys at 210-240 min post-injection, respectively. Our results suggest that [(123)I]ADAM SPECT has potential for evaluating the serotonin transporter changes in human PD.

Surgical anatomy of the gastroduodenal artery in Chinese adults and its clinical applications.

BACKGROUND/AIMS: Hemorrhage occurs in 15-25% of duodenal ulcers, mostly on the posterior wall of the proximal duodenum. Erosion of the gastroduodenal artery is responsible for serious hemorrhages. Therefore, the relationship between bile duct and gastroduodenal artery should be discerned to prevent bile duct injury. METHODOLOGY: Cadavers from 52 Chinese adults (44 males, 8 females) were dissected for the anatomic relationships of the GDA and bile duct. RESULTS: The gastroduodenal artery has many possible origins, with the common hepatic artery (92.3%) the most common. The mean distance between gastroduodenal artery and pylorus was 2.7 cm; arterial length (from its origin) was 1.2 cm. The relationships between gastroduodenal artery and bile duct could be divided into 4 anatomic types according to Prudhomme's classification. We found 22 samples (42%) of Type 1; 10 samples (19%) of Type 2; 14 samples (27%) of Type 3 (in 8 samples of Type 3, there was about 8mm thickness of pancreatic tissue between the artery and the bile duct); 6 samples (12%) of Type 4. In 12 cases (24%) there was no interposed pancreatic tissue. CONCLUSIONS: These anatomic variations could lead to injury during surgical intervention. Our study provides detailed information about anatomic variability in Chinese adults that may help avoid such injury to the common bile duct during duodenal bleeding hemostasis.

Chondroitinase ABC promotes axonal re-growth and behavior recovery in spinal cord injury.

In spinal cord injury, the injury could trigger some inhibitory signal cascades to promote chondroitin sulfate proteoglycans (CSPGs), the structures of scar tissues, formation. CSPGs could limit axonal regeneration mainly through the glycosaminoglycan (GAG) chain in the lesion site were suggested. We hypothesized that the digestion of CSPGs by chondroitinase ABC (ChABC) might decrease the inhibitory effects of limiting axonal re-growth after spinal cord injury. We compared the digesting products of CSPGs such as 2B6 by ChABC with the untreated control group and found no immunostaining of 2B6 in control group. The smaller size scars of ChABC-treatment were observed via CS-56, a type of CSPGs, 8 weeks after transection by immunohistochemistry. The inhibitory effects of CSPGs withdraw GAGs following ChABC-treatment would reduce, and immunopositive GAP-43 newly outgrown fibers were identified. In the animal trials, ChABC-treatment could improve motor function through BBB locomotor's test and reduce limiting ability of scar tissues to promote axonal regeneration via changing the structure of CSPGs by immunohistochemistry with GAP-43.

Surgical anatomy of the recurrent laryngeal nerves and its clinical applications in chinese adults.

PURPOSE: When removing the thyroid gland, great care must be taken to avoid damaging the recurrent laryngeal nerves (RLNs). The present study aims to present a clear picture of certain anatomical features of the RLNs in relation to the inferior thyroid artery (ITA), the tracheoesophageal groove (TE), Berry's ligament, and the inferior cornu of the thyroid cartilage in Chinese adults. METHODS: We removed a collective 120 RLNs from 60 Chinese adult cadavers (52 men and 8 women), and examined their anatomic course and relationship on both sides. RESULTS: The right and left RLNs were found in the tracheoesophageal groove in 78.3% and 91.3% of cases, respectively. Both RLNs were found posterior to and to the right of the ITA in 80% of cases, and one was found on the left side of the ITA in 91.7%. Most of the RLNs were within 3 mm of Berry's ligament, with a laryngeal entry point about 0.8 cm below and just anterior to the inferior horn of the thyroid cartilage. CONCLUSIONS: The inferior cornu of the thyroid cartilage is a reliable landmark in identifying the RLNs. Racial variations between Caucasians and Chinese may explain some anatomic differences.

Horseradish peroxidase localization of sympathetic postganglionic and parasympathetic preganglionic neurons innervating the monkey heart.

The localization of the sympathetic postganglionic and parasympathetic preganglionic neurons innervating the monkey heart were investigated through retrograde axonal transport with horseradish peroxidase (HRP). HRP (4 mg or 30 mg) was injected into the subepicardial and myocardial layers in four different cardiac regions. The animals were euthanized 84-96 hours later and fixed by paraformaldehyde perfusion via the left ventricle. The brain stem and the paravertebral sympathetic ganglia from the superior cervical, middle cervical, and stellate ganglia down to the T9 ganglia were removed and processed for HRP identification. Following injection of HRP into the apex of the heart, the sinoatrial nodal region, or the right ventricle, HRP-labeled sympathetic neurons were found exclusively in the right superior cervical ganglion (64.8%) or in the left superior cervical ganglion (35%). Fewer labeled cells were found in the right stellate ganglia. After HRP injection into the left ventricle, labeled sympathetic cells were found chiefly in the left superior cervical ganglion (51%) or in the right superior cervical ganglion (38.6%); a few labeled cells were seen in the stellate ganglion bilaterally and in the left middle cervical ganglion. Also, in response to administration of HRP into the anterior part of the apex, anterior middle part of the right ventricle, posterior upper part of the left ventricle, or sinoatrial nodal region, HRP-labeled parasympathetic neurons were found in the nucleus ambiguus on both the right (74.8%) and left (25.2%) sides. No HRP-labeled cells were found in the dorsal motor nucleus of the vagus on either side.

Alteration in cardiovascular function and body surface temperature during percutaneous stereotactic upper thoracic ganglionectomy and sympathectomy in palmar hyperhidrotic patients.

We assessed changes in cardiovascular function, specifically arterial blood pressure and heart rate in 6 palmar hyperhidrotic patients before, during, and after T2 and T3 ganglionectomy and sympathectomy. We also assessed changes in skin temperature, specifically at the forehead, axilla, thumb, loin, and sole of the foot (all bilaterally) in 10 palmar hyperhidrotic patients before, during, and after T2 ganglionectomy and sympathectomy. In both methods, ganglionectomy and sympathectomy were done by percutaneous stereotactic thermocoagulation, under local anesthesia, at room temperature 21.4 +/- 0.6 degrees C. During the procedure we found a significant acute decrease in systolic and pulse pressures, from 153 +/- 10 to 127 +/- 9 and from 80 +/- 7 to 56 +/- 4mmHg respectively, and a lesser decrease in diastolic pressure; heart rate showed no statistically significant changes. We also noted a marked increase in thumb temperature, from 21.2 +/- 0.6 to 36.0 +/- 0.1 degrees C, with a mean increase of 14.8 degrees C, at a room temperature 21.4 +/- 0.6 degrees C, after complete bilateral T2 ganglionectomy and sympathectomy. Skin temperature at the forehead, axilla, loin, and sole of the foot, all measured bilaterally, showed no significant increase, although there was a decrease in sweating in both forehead and axillary regions. The decrease in systolic and pulse pressures observed during the thermocoagulation procedure were temporary effects. The increase in thumb temperature, however, appears to be a permanent effect for palmar hyperhidrotic patients. Finally, the data indicate that the sympathetic innervation of the blood vessel in the periphery presents a segmental organization.