Prescription of Radix Salvia miltiorrhiza in Taiwan: A Population-Based Study Using the National Health Insurance Research Database

Objective: While radix Salvia miltiorrhiza (Danshen; RSM) is commonly used in Chinese herbal medicine, its current usage has not yet been analyzed in a large-scale survey. This study aimed to investigate the conditions for which RSM is prescribed and the utilization of RSM in Taiwan.

Methods: 1 million beneficiaries enrolled in the Taiwan National Health Insurance Research Database were sampled to identify patients who were prescribed RSM. Next, the diagnoses of these patients based on the International Classification of Diseases 9th Revision Clinical Modification code were analyzed. Logistic regression analysis was employed to estimate the odds ratio (OR) for RSM utilization.

Results: Patients with disorders of menstruation and abnormal bleeding from the female genital tract due to other causes were the diagnostic group most commonly treated with RSM (9.48%), followed by those with general (9.46%) and cardiovascular symptoms (4.18%). Subjects treated with RSM were mostly aged 35–49 years (30.1%). The most common combination of diseases for which RSM was prescribed (0.17%) included menopausal disorders and general symptoms. Women were more likely to receive RSM than men (OR = 1.75, 95% confidence interval = 1.73–1.78). RSM was frequently combined with Yan-Hu-Suo and Jia-Wei-Xiao-Yao-San for clinical use.

Conclusion: To date, this is the first study to identify the most common conditions for which RSM is used in modern Taiwan. The results indicate RSM as a key medicinal herb for the treatment of gynecological diseases, including menstrual disorders, female genital pain, menopausal disorders, etc. The most common combination for which RSM is prescribed is menopausal disorders and general symptoms. Further research is needed to elucidate the optimal dosage, efficacy, and safety of RSM.

Chinese Herbal Products for Non-Motor Symptoms of Parkinson's Disease in Taiwan: A Population-Based Study

Objective: Combinations of Chinese herbal products (CHPs) are widely used for Parkinson’s disease (PD) in Taiwan. Thereby, we investigated the use of CHPs in patients with PD.

Methods: This study was a population-based cohort study that analyzed the data of patients with PD from the National Health Insurance Research Database. A total of 9,117 patients were selected from a random sample of one million individuals included in this database. We used multiple logistic regression models to estimate the adjusted odds ratios of the demographic factors and analyzed the formula and single CHPs commonly used for PD.

Results: Traditional Chinese medicine users were more commonly female, younger, of white-collar status, and residents of Central Taiwan. Chaihu-Jia-Longgu-Muli-Tang was the most commonly used formula, followed by Ma-Zi-Ren-Wan and then Shao-Yao-Gan-Cao-Tang. The most commonly used single herb was Uncaria tomentosa (Willd. ex Schult.) DC., followed by Gastrodia elata Blume and then Radix et Rhizoma Rhei (Rheum palmatum L., Rheum tanguticum Maxim. ex Balf., and Rheum officinale Baill.). Chaihu-Jia-Longgu-Muli-Tang and U. tomentosa (Willd. ex Schult.) DC. have shown neuroprotective effects in previous studies, and they have been used for managing non-motor symptoms of PD.

Conclusion: Chaihu-Jia-Longgu-Muli-Tang and U. tomentosa (Willd. ex Schult.) DC. are the most commonly used CHPs for PD in Taiwan. Our results revealed the preferences in medication prescriptions for PD. Further studies are warranted to determine the effectiveness of these CHPs for ameliorating the various symptoms of PD, their adverse effects, and the mechanisms underlying their associated neuroprotective effects.

Laser acupuncture-induced analgesic effect and molecular alterations in an incision pain model: a comparison with electroacupuncture-induced effects

Low-level laser acupuncture (LLLA) produces photobiomodulation through acupuncture point and is an alternative to low-level laser therapy. Although the analgesic effect of LLLA on chronic pain has been proven, its effect on acute postincisional pain has yet to be investigated. A plantar incision (PI) model was used to mimic human postsurgical pain. Male adult rats received GaAlAs laser irradiation at the right ST36 acupoint immediately after operation and on the following 4 days. Three laser treatment groups (two red laser groups with a 30- or 15-min treatment duration and one 30-min near-infrared laser group) were compared with sham LLLA and naive groups and an electroacupuncture (EA) group (separate study). Behavioral withdrawal thresholds of both hind paws were measured before and after incision. Expression of mitogen-activated protein kinases (p-ERK and p-p38), inducible nitric oxide synthase (iNOS), and tumor necrosis factor (TNF) in the spinal cord was analyzed. All three LLLA treatments attenuated post-PI tactile allodynia in the ipsilateral paw, but only the 30-min red laser treatment affected the contralateral paw and had similar efficacy to that of EA. All laser treatments barely reduced heat hyperalgesia in both hind paws. At 3 days after PI, the 30-min red laser group showed reversed increases of PI-induced p-ERK, p-p38, and iNOS but not TNF expression in the spinal cord. Repetitive LLLA treatments ameliorated PI-induced mechanical pain. The inhibition of multiple sensitization signals highlights the unique clinical role of LLLA. Thus, LLLA is an alternative to EA as an adjuvant for postoperative pain control.

Decreased risk of dementia in migraine patients with traditional Chinese medicine use: a population-based cohort study

Patients with migraine are reportedly at increased risk of developing dementia. We aimed to investigate the association between traditional Chinese medicine (TCM) use and dementia risk in migraine patients. This longitudinal cohort study used the Taiwanese National Health Insurance Research Database to identify 32,386 diagnosed migraine patients aged 20 years and above who received treatment from 1997 to 2010. To balance comparability between TCM users and non-TCM users, we randomly selected equal numbers from each group, and compared subgroups compiled based on combinations of age, sex, index year, and year of migraine diagnosis. All enrollees received follow-up until the end of 2013 to measure dementia incidence. We identified 1,402 TCM users and non-TCM users after frequency matching. A total of 134 subjects were newly diagnosed with dementia during the follow-up period. TCM users were significantly less likely to develop dementia than non-TCM users. The most frequently prescribed formulae and single Chinese herbal products were Jia-Wei-Xiao-Yao-San and Yan-Hu-Suo, respectively. This population-based study revealed a decreased dementia risk in migraine patients with TCM use. These findings may provide a reference for dementia prevention strategies, and help integrate TCM into clinical intervention programs that provide a favorable prognosis for migraine patients.

A comparison of the delayed outward potassium current between the nucleus ambiguus and hippocampus: sensitivity to paeonol

Whole-cell patch-clamp recordings investigated the electrophysiological effects of 2'-hydroxy-4'-methoxyacetophenone (paeonol), one of the major components of Moutan Cortex, in hippocampal CA1 neurons and nucleus ambiguus (NA) neurons from neonatal rats as well as in lung epithelial H1355 cells expressing Kv2.1 or Kv1.2. Extracellular application of paeonol at 100μM did not significantly affect the spontaneous action potential frequency, whereas paeonol at 300μM increased the frequency of spontaneous action potentials in hippocampal CA1 neurons. Paeonol (300μM) significantly decreased the tetraethylammonium-sensitive outward current in hippocampal CA1 neurons, but had no effect upon the fast-inactivating potassium current (IA). Extracellular application of paeonol at 300μM did not affect action potentials or the delayed outward currents in NA neurons. Paeonol (100μM) reduced the Kv2.1 current in H1355 cells, but not the Kv1.2 current. The inhibitor of Kv2, guangxitoxin-1E, reduced the delayed outward potassium currents in hippocampal neurons, but had only minimal effects in NA neurons. We demonstrated that paeonol decreased the delayed outward current and increased excitability in hippocampal CA1 neurons, whereas these effects were not observed in NA neurons. These effects may be associated with the inhibitory effects on Kv2.1 currents.

Chinese Herbal Products for Ischemic Stroke

Traditional Chinese herbal products (CHPs) have been described in ancient medicine systems as treatments for various stroke-associated ailments. This study is aimed to investigate the prescription patterns and combinations of CHPs for ischemic stroke in Taiwan. Prescriptions of CHPs for ischemic stroke were obtained from the National Health Insurance Research Database (NHIRD) of Taiwan. Every prescription with a leading diagnosis of ischemic stroke made during 2000-2010 was analyzed. Descriptive statistics were applied to the pattern of co-prescriptions. Multiple logistic regression models were used to assess demographic and risk factors that are correlated with CHP use. The dataset of inpatient claims data contained information on 15,896 subjects who experienced ischemic stroke from 2000 to 2010. There was an average of 5.82 CHPs in a single prescription for subjects with ischemic stroke. Bu-yang-huan-wu-tang (BYHWT) (40.32%) was by far the most frequently prescribed formula CHP for ischemic stroke, and the most commonly used combination of two-formula-CHP was BYHWT with Shu-jin-huo-xue-tang (SJHXT) (4.40%). Dan Shen (16.50%) was the most commonly used single CHP for ischemic stroke, and the most commonly used combination of two single CHPs was Shi Chang Pua with Yuan Zhi (4.79%). We found that BYHWT and Dan Shen were the most frequently prescribed formula and single CHP for ischemic stroke, respectively. These results provide information about individualized therapy and may contribute to further pharmacologic experiments and clinical trials.

Phytobeneficial Properties of Bacteria Isolated from the Rhizosphere of Maize in Southwestern Nigerian Soils

Biocontrol agents isolated outside Africa have performed inconsistently under field conditions in Africa. The development of indigenous phytobeneficial microbial strains that suit local environments may help enhance competitiveness with in situ microorganisms and effectiveness at suppressing local pathogen strains. We isolated bacteria from the rhizosphere of maize growing in southwestern Nigeria and assessed them for growth-promoting characteristics. The best isolates were characterized using 16S rRNA genes and were further evaluated in the greenhouse on maize seedlings. Four isolates (EBS8, IGBR11, EPR2, and ADS14) were outstanding in in vitro assays of antagonistic activity against a local strain of Fusarium verticillioides, phosphate solubilization efficiency, chitinase enzyme activity, and indole-3-acetic acid production. Inoculation of maize seeds with these isolates resulted in ≥95% maize seed germination and significantly enhanced radicle and plumule length. In the greenhouse, maize seedling height, stem girth, number of leaves, leaf area, shoot mass (dry matter), and nutrient contents were significantly enhanced. The bioprotectant and phytobeneficial effects were strongest and most consistent for isolate EBS8, which was identified as a Bacillus strain by 16S rRNA gene analysis. As a bacterial strain that exhibits multiple growth-promoting characteristics and is adapted to local conditions, EBS8 should be considered for the development of indigenous biological fertilizer treatments.

Spinal p38 activity and analgesic effect after low- and high-intensity electroacupuncture stimulation in a plantar incision rat model

AIMS

Postoperative pain is a major problem. Electroacupuncture (EA) has been accepted as a useful and low-risk complementary therapy for post-operative pain. Animal studies indicate that surgical incision activates p38 MAPK in the spinal microglia, which critically contributes to post-incisional nociceptive development. How EA affects incision-induced p38 activation is important but yet to be fully elucidated.

METHODS

Male adult rats received plantar incision (PI) at the right hind paw followed by 30-min EA of 4-Hz, one of two intensities (3 and 10mA), and at right ST36 (Zusanli) acupoint immediately after PI and for 3 successive days. EA analgesia was evaluated by von Frey fibers and Hargreaves' tests. Spinal p38 activation was examined by immunostaining. In separate groups, SB203580, a p38 inhibitor, was intrathecally injected alone or with EA to test the combining effect on nociception and spinal phospho-p38.

KEY FINDINGS

EA of 10-mA significantly ameliorated mechanical allodynia, but 3-mA did not. None of them altered thermal hyperalgesia. Repeated EA could not inhibit phospho-p38 in the PI rats, contrarily, EA per se significantly induced phospho-p38 in the normal rats. Intrathecal SB203580 injection dose-dependently prevented PI-induced allodynia. Combination of low-dose SB203580 and 3-mA EA, which were ineffective individually, profoundly reduce post-PI allodynia.

SIGNIFICANCE

We demonstrated that 10-mA EA exerts a significant inhibition against post-PI mechanical hypersensitivity via a p38-independent pathway. Importantly, co-treatment with low-dose p38 inhibitor and 3-mA EA can counteract spinal phospho-p38 to exert strong analgesic effect. Our finding suggests a novel strategy to improve EA analgesic quality.

Laser acupuncture therapy in patients with treatment-resistant temporomandibular disorders

Objective

To investigate the clinical effects of laser acupuncture therapy for temporomandibular disorders (TMD) after ineffective previous treatments.

Methods

A retrospective observational study was conducted in 29 treatment-resistant TMD patients (25 women, 4 men; age range, 17–67 years). Subjects were treated 3 times per week for 4 weeks with the Handylaser Trion (GaAlAs laser diode, 810 nm, 150 mW, pulsed waves), which delivered 0.375 J of energy (5 s) to ST7, ST6, and LI4 and 3 J (40 s) to each Ashi point, 7.5–26.25 J/cm² in total. The visual analog scale (VAS) and maximal mouth opening (MMO) were evaluated before and after treatment.

Results

VAS analysis showed that the patients were free of pain at rest (endpoint) after 5.90±6.08 sessions of laser acupuncture for acute TMD and after 16.21±17.98 sessions for chronic TMD. The VAS score on palpation of the temporomandibular joint reduced to 0.30±0.67 for patients with acute TMD (p = 0.005) and to 0.47±0.84 for those with chronic TMD (p<0.001). The MMO significantly increased in patients with acute TMD (7.80±5.43 mm, p = 0.008) and in patients with chronic TMD (15.58±7.87 mm, p<0.001).

Conclusions

Our study shows that laser acupuncture therapy improves the symptoms of treatment-resistant TMD. Further studies with a more appropriate design, involving long-term follow-up examinations in a larger patient sample, are needed to evaluate its efficacy.

DPP-4 inhibitor attenuates toxic effects of indoxyl sulfate on kidney tubular cells

Diabetic nephropathy is a common causative factor of chronic kidney disease (CKD). DPP-4 inhibitor has the ability to improve kidney function and renal microvasculature. In the present study, we investigate the deleterious effects of IS on proximal tubular cells and the protective role of DPP-4 inhibitor. Human kidney 2 (HK-2) cells were exposed to IS in the presence or absence of DPP-4 inhibitor. Effects of DPP-4 inhibitor on viability of HK-2 cells were determined by MTT assay. Reactive oxygen species (ROS) production was examined using fluorescent microscopy. Levels of cleaved caspase-3, transforming growth factor-beta (TGF-β), α-smooth muscle actin (α-SMA) and NF-kappaB p65 and phosphorylation of AKT and extracellular signal-regulated kinase (ERK) were detected by immunoblotting. Production of ROS and level of cleaved caspase-3 were increased by IS in a dose-dependent manner. The phosphorylation of AKT and ERK p65 were decreased alongside activation of NF-κB. Expression of TGF-β and α-SMA, were upregulated in IS-treated HK-2 cells. Treatment with DPP-4 inhibitor resulted in a significant increase in cell viability and a decrease of ROS production in IS-treated HK-2 cells. DPP-4 inhibitor restored IS-induced deactivations of AKT and ERK and inhibited activation of NF-κB in IS-treated HK-2 cells. Moreover, DPP-4 inhibitor could also attenuate IS-induced up-regulation of TGF-β and α-SMA expression. These findings suggest that DPP-4 inhibitor possesses anti-apoptotic activity to ameliorate the IS-induced renal damage, which may be partly attributed to regulating ROS/p38MAPK/ERK and PI3K-AKT pathways as well as downstream NF-κB signaling pathway.

Wu-Ling-San Formula Inhibits the Crystallization of Calcium OxalateIn Vitro

Urinary stone disease is a common disease and has a high rate of recurrence. There is no ideal long-term medical treatment to prevent the recurrence of urinary stones. Wu-Ling-San (WLS) formula has been used for centuries in China for long-term treatment of urological diseases. However, no pharmacological studies have been conducted to evaluate its effect on urinary stone disease. Therefore, using a photospectrometer, we studied the effects of WLS on nucleation, growth and aggregation of calcium oxalate in vitro. The results showed that WLS extract significantly slowed the speed of calcium oxalate ( CaOx ) crystal nucleation. WLS extracts at concentrations of 6.25, 12.5, 25, and 50 mg/ml inhibited nucleation of calcium oxalate crystallization by 344, 387, 543, and 943%, respectively. WLS extracts did not inhibit the growth of CaOx crystallization; however, WLS extracts at concentrations of 12.5 and 25 mg/ml significantly inhibited the aggregation of CaOx crystallization by 74.24% and 75.05%, respectively. WLS extract at a concentration of 50 mg/ml inhibited CaOx aggregation by 92.49%. In conclusion, our results indicate that WLS extract inhibited calcium oxalate nucleation and aggregation, and may have the potential to prevent stone recurrence.

Gastrodia elata BL Mediates the Suppression of nNOS and Microglia Activation to Protect Against Neuronal Damage in Kainic Acid-Treated Rats

Our previous studies showed that Gastrodia elata (GE), an herb used in traditional Chinese medicine, has both anti-convulsive and free radical-scavenging activities in kainic acid (KA)-treated rats. The aim of the present study was to further investigate possible physiological mechanisms of GE against activities of neuronal nitric oxide synthase (nNOS) and microglia in KA-treated rats; 0.5 g/kg and 1.0 g/kg of GE extract were administered orally, whereas 20 mg/kg of N-nitro-L-arginine methyl ester (L-NAME) was administered intraperitoneally (ip), both at 30 minutes prior to KA (2 μg/2 μl) being injected into the right hippocampus region of rats. ED1-staining, apoptotic, inducible nitric oxide synthase (iNOS), and nNOS-staining cells were observed in the hippocampus region. The results indicated that 1.0 g/kg of GE and 20 mg/kg of L-NAME reduced the counts of ED1-stained cells, and 0.5 g/kg and 1.0 g/kg of GE, and 20 mg/kg of L-NAME reduced the numbers of apoptotic cells and nNOS-staining cells. In addition, 20 mg/kg of L-NAME also reduced the numbers of iNOS-staining cells, but 0.5 g/kg and 1.0 g/kg of GE did not. This study demonstrated that GE was able to reduce nNOS, microglia activation and apoptosis, suggesting that GE has a protective effect against neuronal damage in KA-treated rats.

Variations of Brain Activities of Acupuncture to TE5 of Left Hand in Normal Subjects

This paper presents the evident effects of acupoint stimulation, using EEG (electroencephalogram) measurements. With acupuncture stimulation and the EEG measurement on the same meridian, EEG is able to accurately detect the effects of acupunctural point stimulation on brain waves.

In this study, 24 subjects without heart or neural diseases were randomly separated into two groups of 12, named test and control groups. Similar procedures are performed; the subjects lay on a bed with eyes closed for ten minutes as the baseline. The test group received acupuncture at their Waiguan points (TE5) on their left hands for 20 minutes, while the control group did not. EEGs are recorded during pre-acupuncture, acupuncture stimulation and post-acupuncture stimulation periods. The EEG electrodes are at the T3, T4, O1 and O2 locations. Continuous wavelet transformation analysis is adopted; therefore, EEGs are divided into the following bands: δ (0.5–4HZ), θ (4–8HZ), α (8–13HZ) and β (13–30HZ).

During acupuncture stimulation, the θ energy is increased and had statistical differences at all electrode points, T3, T4, O1 and O2. Upon removing the needle, the energy at the T3 and T4 points slowly declined and revealed obvious statistical differences. During acupuncture, only α energy has been noted to have statistical difference and it was increased at the T3 point. However, the energy was decreased and had no statistical difference after five minutes.

Acupuncture is proven to be able to affect brain waves, as the stimulation might have changed the tissues between the cranium and scalp; therefore, the brain waves are detected more easily.

IGF-I enhances α5β1 integrin expression and cell motility in human chondrosarcoma cells

Chondrosarcoma is a type of highly malignant tumor with a potent capacity to invade locally and cause distant metastasis. Chondrosarcoma shows a predilection for metastasis to the lungs. Integrins are the major adhesive molecules in mammalian cells and have been associated with metastasis of cancer cells. Insulin-like growth factor-I (IGF)-I plays an important role in regulating cell growth, proliferation, survival, and metabolism. However, the effects of IGF-I in migration and integrin expression in chondrosarcoma cells are largely unknown. In this study, we found that IGF-I increased the migration and the expression of α5β1 integrin in human chondrosarcoma cells. Pretreatment of cells with IGF-I receptor antibody reduced IGF-I-induced cell migration and integrin expression. Activations of phosphatidylinositol 3-kinase (PI3K), Akt, and nuclear factor-κB (NF-κB) pathways after IGF-I treatment were demonstrated, and IGF-I-induced expression of integrin and migration activity was inhibited by the specific inhibitor and mutant of PI3K, Akt, and NF-κB cascades. Taken together, our results indicated that IGF-I enhances the migration of chondrosarcoma cells by increasing α5β1 integrin expression through the IGF-I receptor/PI3K/Akt/NF-κB signal transduction pathway.

The novel benzimidazole derivative, MPTB, induces cell apoptosis in human chondrosarcoma cells

Chondrosarcoma is a malignant primary bone tumor that responds poorly to both chemotherapy and radiation therapy. This study is the first to investigate the anti-cancer effects of the new benzimidazole derivative (5-methyl-2(pyridine-3-yl)-1-(3,4,5-trimethoxybenzyl)benzimidazole; MPTB) in human chondrosarcoma cells. MPTB-induced cell apoptosis in two human chondrosarcoma cell lines, JJ012 and SW1353 but not in primary chondrocytes. MPTB-induced upregulation of Bax and Bak and dysfunction of mitochondria in chondrosarcoma. MPTB triggered endoplasmic reticulum (ER) stress, as indicated by changes in cytosol calcium levels, and increased glucose-regulated protein (GRP) expression. MPTB also increased calpain expression. Transfection of cells with GRP78 or calpain siRNA reduced MPTB-mediated cell apoptosis in JJ012 cells. Importantly, animal studies have revealed a dramatic 44% reduction in tumor volume after 21 d of treatment. This study demonstrates novel anti-cancer activity of MPTB against human chondrosarcoma cells and in murine tumor models.

DNIC-mediated analgesia produced by a supramaximal electrical or a high-dose formalin conditioning stimulus: roles of opioid and alpha2-adrenergic receptors

Background

Diffuse noxious inhibitory controls (DNIC) can be produced by different types of conditioning stimuli, but the analgesic properties and underlying mechanisms remain unclear. The aim of this study was to differentiate the induction of DNIC analgesia between noxious electrical and inflammatory conditioning stimuli.

Methods

First, rats subjected to either a supramaximal electrical stimulation or an injection of high-dose formalin in the hind limb were identified to have pain responses with behavioral evidence and spinal Fos-immunoreactive profiles. Second, suppression of tail-flick latencies by the two noxious stimuli was assessed to confirm the presence of DNIC. Third, an opioid receptor antagonist (naloxone) and an α2-adrenoreceptor antagonist (yohimbine) were injected, intraperitoneally and intrathecally respectively, before conditioning noxious stimuli to test the involvement of descending inhibitory pathways in DNIC-mediated analgesia.

Results

An intramuscular injection of 100 μl of 5% formalin produced noxious behaviors with cumulative pain scores similar to those of 50 μl of 2% formalin in the paw. Both electrical and chemical stimulation significantly increased Fos expression in the superficial dorsal horns, but possessed characteristic distribution patterns individually. Both conditioning stimuli prolonged the tail-flick latencies indicating a DNIC response. However, the electrical stimulation-induced DNIC was reversed by yohimbine, but not by naloxone; whereas noxious formalin-induced analgesia was both naloxone- and yohimbine-reversible.

Conclusions

It is demonstrated that DNIC produced by different types of conditioning stimuli can be mediated by different descending inhibitory controls, indicating the organization within the central nervous circuit is complex and possibly exhibits particular clinical manifestations.

Bradykinin enhances cell migration in human chondrosarcoma cells through BK receptor signaling pathways

Bradykinin (BK) is an inflammatory mediator, and shows elevated levels in regions of severe injury and inflammatory diseases. BK has recently been shown to be involved in carcinogenesis and cancer progression. In this study, we found that BK increased the migration and the expression of alpha2beta1 integrin in human chondrosarcoma cells. We also found that human chondrosarcoma tissues had significantly higher expression of the B1 and B2 receptors comparing to normal cartilage. BK-mediated migration and integrin up-regulation was attenuated by B1 and B2 BK receptor siRNA or antagonist. Activations of phospholipase C (PLC), protein kinase Cdelta (PKCdelta), and NF-kappaB pathways after BK treatment was demonstrated, and BK-induced integrin expression and migration activity was inhibited by the specific inhibitor of PLC, PKCdelta, and NF-kappaB cascades. Taken together, our results indicated that BK enhances the migration of chondrosarcoma cells by increasing alpha2beta1 integrin expression through the BK receptors/PLC/PKCdelta/NF-kappaB signal transduction pathway.

Cyr61 increases migration and MMP-13 expression via alphavbeta3 integrin, FAK, ERK and AP-1-dependent pathway in human chondrosarcoma cells

Cysteine-rich 61 (Cyr61), from the CCN gene family, is a secreted and matrix-associated protein, which is involved in many cellular activities such as growth and differentiation. However, the effect of Cyr61 on migration activity in human chondrosarcoma cells is mostly unknown. Here, we found that Cyr61 increased the migration and expression of matrix metalloproteinase (MMP)-13 in human chondrosarcoma cells (JJ012 cells). RGD peptide, alphavbeta3 monoclonal antibody and mitogen-activated protein kinase (MEK) inhibitors (PD98059 and U0126) but not RAD peptide inhibited the Cyr61-induced increase of the migration and MMP-13 upregulation of chondrosarcoma cells. Cyr61 stimulation increased the phosphorylation of focal adhesion kinase (FAK) and extracellular signal-regulated kinase (ERK). In addition, activator protein-1 (AP-1) decoy oligodeoxynucleotide also suppressed the MMP-13 messenger RNA and enzyme activity enhanced by Cyr61. Moreover, Cyr61 increased the binding of c-Fos and c-Jun to the AP-1 element on the MMP-13 promoter. Taken together, our results indicated that Cyr61 enhances the migration of chondrosarcoma cells by increasing MMP-13 expression through the alphavbeta3 integrin receptor, FAK, ERK, c-Fos/c-Jun and AP-1 signal transduction pathway.

Osteopontin increases lung cancer cells migration via activation of the alphavbeta3 integrin/FAK/Akt and NF-kappaB-dependent pathway

Tumor malignancy is associated with several features such as proliferation ability and frequency of metastasis. Osteopontin (OPN), which is abundantly expressed in bone matrix, is involved in cell adhesion, migration, invasion and cell proliferation via interaction with its receptor, alphavbeta3 integrin. However, the effect of OPN on migration activity in human lung cancer cells is mostly unknown. Here we found that OPN increased the migration via activation of alphavbeta3 integrin in human lung cancer cells (A549 cells). Phosphatidylinositol 3-kinase inhibitor (PI3K; Ly294002), Akt inhibitor or ERK inhibitor (PD98059) inhibited the OPN-induced increase in the migration of lung cancer cells. OPN stimulation increased the phosphorylation of focal adhesion kinase (FAK), p85 subunit of PI3K, serine 473 of Akt and ERK. In addition, treatment of A549 cells with NF-kappaB inhibitor (PDTC) or IkappaB protease inhibitor (TPCK) inhibited OPN-induced migration of lung cancer cells. Stimulation of A549 cells with OPN also induced IkappaB kinase alpha/beta (IKK alpha/beta) phosphorylation, IkappaBalpha phosphorylation, p65 Ser(536) phosphorylation, and kappaB-luciferase activity. The OPN-mediated increases in IKK alpha/beta, IkappaBalpha and p65 Ser(536) phosphorylation were inhibited by Ly294002, Akt inhibitor and PD98059. Co-transfection with FAK, p85, Akt and ERK mutants also reduced the OPN-induced kappaB-luciferase activity. Taken together, these results suggest that OPN acts through alphavbeta3 integrin, which in turn activates the FAK, PI3K, Akt, ERK and NF-kappaB pathways, contributing to the migration of lung cancer cells.

Effects of electrical stimulation at different frequencies on regeneration of transected peripheral nerve

BACKGROUND

Electrical stimulation of damaged peripheral nerve may aid regeneration.

OBJECTIVE

The purpose of this study was to determine whether 1 mA of percutaneous electrical stimulation at 1, 2, 20, or 200 Hz augments regeneration between the proximal and distal nerve stumps.

METHODS

A10-mm gap was made in rat sciatic nerve by suturing the stumps into silicone rubber tubes. A control group received no stimulation. Starting 1 week after transection, electrical stimulation was applied between the cathode placed at the distal stump and the anode at the proximal stump every other day for 6 weeks.

RESULTS

Higher frequency stimulation led to less regeneration compared to lower frequencies. Quantitative histology of the successfully regenerated nerves revealed that the groups receiving electrical treatment, especially at 2 Hz, had a more mature structure with a smaller cross-sectional area, more myelinated fibers, higher axon density, and higher ratio of blood vessel to total nerve area compared with the controls. Electrophysiology showed significantly shorter latency, longer duration, and faster conduction velocity.

CONCLUSION

Electrical stimulation can have either a positive or negative impact on peripheral nerve regeneration. Clinical trials that combine stimulation with rehabilitation must determine the parameters that are most likely to be safe and effective.

Transforming growth factor-beta1 increases cell migration and beta1 integrin up-regulation in human lung cancer cells

Transforming growth factor-beta1 (TGF-beta1) plays a crucial role in adhesion and migration of human cancer cells. Besides, integrins are the major adhesive molecules in mammalian cells. Here we found that TGF-beta1 increased the migration and cell surface expression of beta1 integrin in human lung cancer cells (A549 cells). TGF-beta1 stimulation increased phosphorylation of p85alpha subunit of phosphatidylinositol 3-kinase (PI3K) and Ser(473) of Akt was determined. Besides, we performed that PI3K inhibitor (Ly294002) or Akt inhibitor suppressed the TGF-beta1-induced migration activities of A549 cells. Treatment of A549 cells with NF-kappaB inhibitor (PDTC) or IkappaB protease inhibitor (TPCK) also repressed TGF-beta1-induced cells migration and beta1 integrins expression. In addition, treatment of A549 cells with TGF-beta1 induced IkappaB kinase alpha/beta (IKKalpha/beta) phosphorylation, IkappaB phosphorylation, p65 Ser(536) phosphorylation, and kappaB-luciferase activity. Furthermore, the TGF-beta1-mediated increases in IKKalpha/beta, IkappaBalpha phosphorylation and p65 Ser(536) phosphorylation were inhibited by Ly294002 and Akt inhibitor. Co-transfection with p85alpha and Akt mutants also reduced the TGF-beta1-induced kappaB-luciferase activity. Taken together, our results suggest that TGF-beta1 acts through PI3K/Akt, which in turn activates IKKalpha/beta and NF-kappaB, resulting in the activations of beta1 integrins and contributing the migration of human lung cancer cells.

2-methoxyestradiol induces apoptosis and cell cycle arrest in human chondrosarcoma cells

2-Methoxyestradiol (2ME) is an endogenous metabolite with estrogen receptor-independent anti-tumor activity. The current study seeks to determine the mechanism of anti-tumor activity of 2ME on human chondrosarcoma. 2ME caused a time- and dose-dependent cytotoxity in chondrosarcoma cells, while primary chondrocytes were minimally affected. Cells accumulated in G0/G1 phase in response to 2ME and DAPI stain indicated an induction of apoptosis. Bax, Cytochrome C, and Caspase-3 protein expression were increased, while p53 expression was decreased. A higher Bax/Bcl-2 ratio followed 2ME treatment. 2ME has a potentially promising role as a systemic therapy of chondrosarcoma when the mechanism of action is better delineated.

Ultrasound induces cyclooxygenase-2 expression through integrin, integrin-linked kinase, Akt, NF-kappaB and p300 pathway in human chondrocytes

It has been shown that ultrasound (US) stimulation accelerates fracture healing in the animal models and in clinical studies. However, the precise molecular events generated by US in chondrocytes have not been clarified well. Here we found that US stimulation transiently increased the surface expression of alpha2, alpha5, beta1 or beta3 but not alpha3 or alpha4 integrins in human chondrocytes, as shown by flow cytometric analysis. US stimulation increased prostaglandin E(2) formation as well as the protein and mRNA levels of cyclooxygenase-2 (COX-2). At the mechanistic level, anti-integrin beta1 and beta3 antibodies or beta1 and beta3 integrin small interference RNA attenuated the US-induced COX-2 expression. Integrin-linked kinase (ILK) inhibitor (KP-392), Akt inhibitor, NF-kappaB inhibitor (PDTC) or IkappaB protease inhibitor (TPCK) also inhibited the potentiating action of US. US stimulation promotes kinase activity of ILK, phosphorylation of Akt. In addition, US stimulation also induces IKKalpha/beta phosphorylation, IkappaBalpha phosphorylation, IkappaBalpha degradation, p65 phosphorylation at Ser(276), p65 and p50 translocation from the cytosol to the nucleus, and kappaB-luciferase activity. The binding of p65 to the NF-kappaB element, as well as the recruitment of p300 and the enhancement of p50 acetylation on the COX-2 promoter was enhanced by US. Taken together, our results provide evidence that US stimulation increases COX-2 expression in chondrocytes via the integrin/ILK/Akt/NF-kappaB and p300 signaling pathway.

Effect of low-power pulsed laser on peripheral nerve regeneration in rats

The purpose of this study was to determine whether low-power pulsed laser irradiation could affect the regeneration of a 10-mm gap of rat sciatic nerve created between the proximal and distal nerve stumps, which were sutured into silicone rubber tubes. After 8 weeks of recovery, pulsed laser-irradiated groups at frequencies of 5 kHz and 20 kHz both had significantly lower success percentages of regeneration (50% and 44%, respectively) compared to sham-irradiated controls (100%). In addition, qualitative and quantitative histology of the regenerated nerves revealed a less mature ultrastructural organization with a smaller cross-sectional area and a lower number of myelinated axons in both pulsed laser-irradiated groups than in controls. These results suggest that pulsed laser irradiation could elicit suppressing effects on regenerating nerves.

Use of acupressure to improve gastrointestinal motility in women after trans-abdominal hysterectomy

The purpose of this study was to evaluate the effectiveness of acupressure on gastrointestinal (GI) motility in women after trans-abdominal hysterectomy (TAH). Patients were randomly assigned into two groups of 21 and 20 patients each. The experimental group received acupressure for 3 minutes at each of three meridian points: Neiguan (PC-6), Zusanli (ST-36) and Sanyinjiao (SP-6). The control group received 3 minutes of acupressure on sham points. Acupressure was performed twice a day. A questionnaire was used to determine patients' satisfaction prior to and after afternoon acupressure. GI contractions were measured with a multifunctional stethoscope before and after acupressure. Acupressure of these three meridian points significantly (p < 0.05) increased GI motility in the experimental group, but there was little change in the control group (p > 0.05). Our conclusions are that non-invasive acupressure of these meridian points can significantly improve GI motility and can be incorporated into the technical curriculum and clinical education program of nursing schools. Patients and their family members can be taught to continue this procedure at home to enhance GI motility in patients who have undergone TAH.

Activation of activator protein-1 in cells exposed to electrical stimulation of various parameters used in electroacupuncture therapy

The aim of this study was to investigate the effect of electrical stimulation on activator protein-1 (AP-1) in recombinant liver cells. In order to elucidate the molecular effects of electrical stimulation on cells, AP-1 expression was detected by a luciferase assay. The parameters used were taken from clinical electroacupuncture (EA) therapy as follows: biphasic rectangular symmetrical pulses (frequency: 2, 10 and 100 Hz; pulse width: 50, 80, 130 and 250 microsec; intensity: 1, 2, 5 and 10 mA; time: 5, 10, 20 and 30 minutes). S (10% fetal bovine serum in medium), SF (serum free medium) and 12-O-tetradecanoylphorbol-13-acetate (TPA) treatment represented the experimental, negative and positive groups, respectively. We found that electrical stimulation with 10 Hz, a pulse width of 130 microsec, and a duration of 30 minutes gave a significant increase in AP-1 activity. In contrast, the intensity of the stimulation had no significant effect on AP-1 activity. In conclusion, our data suggest that electrical stimulation with an appropriate frequency, duration and pulse width could cause an increase in AP-1 activity in cells.

Study on hydrogen production with hysteresis in UASB

This paper uses a 10-l UASB (upflow anaerobic sludge blanket) bench-scale reactor to treat the esterification wastewater of a polyethylene terephthalate manufacturing plant. Two organic loading rates are used to evaluate the effect on H2 production of temperature gradually step-down and step-up in the range of 11-25 degrees C. Experimental results show that H2 production is positively related to temperature. H2 production increases with temperature at the higher organic loading rate (4.5 kg COD m(-3)d(-1)). However, the H2 produced does not go back to its original concentration but rather follows a hysteresis curve. This hysteresis also occurs in the corresponding concentrations of COD, acetate, propionate and butyrate. As in the H2 profiles, these parameter curves return clockwise during the temperature step-up. At the lower organic loading rate (2.2 kg COD m(-3)d(-1)), no obvious hysteresis is observed for H2 curve. The pattern of other parameters, except for the propionate, returns counterclockwise resulting in the hysteresis phenomena.

Effector mechanisms of norcantharidin-induced mitotic arrest and apoptosis in human hepatoma cells

NCTD is a demethylated form of cantharidin with antitumor properties, which is now in use as a routine anticancer drug against hepatoma. However, there is limited information on the effect of NCTD on human cancer cells. In the present study, NCTD inhibited proliferation, caused mitotic arrest, then progressed to apoptosis within 96 hr in 3 human hepatoma cell lines: HepG2, Hep3B and Huh-7. NCTD treatment (5 microg/ml) enhanced the expression of Cdc25C and p21(Cip1/Waf1), increasing the phosphorylation of these 2 proteins. In addition, NCTD treatment induced an earlier increase in cyclin B1-associated histone H1 kinase activity within 48 hr, but an approximately 70% reduction of both protein level and kinase activity of cyclin B1 was observed at 72 hr. Treatment with NCTD significantly decreased the expression of p53 protein but did not affect the expression of Cdk1 and p27(Kip1). Moreover, NCTD treatment also increased the phosphorylation of Bcl-2 and Bcl-X(L) but did not affect the expression of Bax or Bad. Bcl-2 phosphorylation appears to inhibit its binding to Bax since less Bax was detected in immunocomplex with Bcl-2 in NCTD-treated HepG2 cells. In addition, NCTD treatment caused activation of caspase-9 and caspase-3, preceding DNA fragmentation and morphologic features of apoptosis. Pretreatment with the broad-spectrum caspase inhibitor z-VAD-fmk markedly inhibited NCTD-induced caspase-3 activity and cell death. These results suggest that phosphorylation of p21(Cip1/Waf1) and Cdc25C and biphasic regulation of cyclin B1-associated kinase activity may contribute to NCTD-induced M-phase cell-cycle arrest. Furthermore, the increase of p21(Cip1/Waf1), phosphorylation of Bcl-2 and Bcl-X(L), activation of caspase-9 and caspase-3 may be the molecular mechanism through which NCTD induces apoptosis.

The effectiveness of Tsu-San-Li (St-36) and Tai-Chung (Li-3) acupoints for treatment of acute liver damage in rats

This study investigated the effects of acupuncture on carbon tetrachloride (CCl4) induced acute liver injury in male rats (n=36). The experimental groups were injected with CCl4 before, during, or after acupuncture therapy. Acupoints similar to the human Tsu-San-Li (St-36) and Tai-Chung (Li-3) were needled bilaterally. Rats treated with CCl4 had higher levels of serum glutamate-oxalate-transaminase (sGOT) and serum glutamate-pyruvate-transaminase (sGPT). Comparing the experimental groups, biochemical and pathological parameters of liver injury were significantly reduced when rats were acupunctured after, not before, CCl4-induced hepatotoxicity. Acupuncture at the Tsu-San-Li and Tai-Chung acupoints cannot prevent acute liver injury but may be effective in treating liver injury induced by carbon tetrachloride in rats.

Induction of persistent sodium current by exogenous and endogenous nitric oxide

Most voltage-gated Na(+) channels inactivate almost completely at depolarized membrane potentials, but in some cells a residual Na(+) current is seen that is resistant to inactivation. This persistent Na(+) current can have a profound impact on the electrical behavior of excitable cells, and the regulation of this property could have important biological consequences. However, the biological signaling mechanisms that regulate the persistence of Na(+) channels are not well understood. This study showed that in nerve terminals and ventricular myocytes nitric oxide (NO) reduced the inactivation of Na(+) current. This effect was independent of cGMP, was blocked by N-ethylmaleimide, and could be elicited in cell-free outside-out patches. Thus, a reactive nitrogen species acts directly on the channel or closely associated protein. Persistent Na(+) current could also be induced by endogenous NO generated enzymatically by NO synthase (NOS). Application of ionomycin to raise the intracellular Ca(2+) concentration in myocytes activated NOS. The NO produced in response to ionomycin was detected with an NO-sensitive fluorescent dye. Persistent Na(+) current was enhanced by the same treatment, and NOS inhibitors abolished both the elevation of NO and the induction of persistent Na(+) current. These experiments show that NO is a potential endogenous regulator of persistent Na(+) current under physiological and pathophysiological conditions.

Direct actions of nitric oxide on rat neurohypophysial K+ channels

1. Nitric oxide (NO) has been shown to modulate neuropeptide secretion from the posterior pituitary. Here we show that NO activates large-conductance Ca2+-activated K+ (BK) channels in posterior pituitary nerve terminals. 2. NO, generated either by the photolysis of caged-NO or with chemical donors, irreversibly enhanced the component of whole-terminal K+ current due to BK channels and increased the activity of BK channels in excised patches. NO also inhibited the transient A-current. The time courses of these effects on K+ current were very different; activation of BK channels developed slowly over several minutes whereas inhibition of A-current immediately followed NO uncaging. 3. Activation of BK channels by NO occurred in the presence of guanylyl cyclase inhibitors and after removal of ATP or GTP from the pipette solution, suggesting a cGMP-independent signalling pathway. 4. The sulfhydryl alkylating agent N-ethyl maleimide (NEM) increased BK channel activity. Pretreatment with NEM occluded NO activation. 5. NO activation of BK channels occurred independently of voltage and cytoplasmic Ca2+ concentration. In addition, NO removed the strict Ca2+ requirement for channel activation, rendering channels highly active even at nanomolar Ca2+ levels. 6. These results suggest that NO, or a reactive nitrogen byproduct, chemically modifies nerve terminal BK channels or a closely associated protein and thereby produces an increase in channel activity. Such activation is likely to inhibit impulse activity in posterior pituitary nerve terminals and this may explain the inhibitory action of NO on secretion.

Ultra-violet light-induced changes in membrane properties in secretory cells

Illumination with ultra-violet is used widely in physiological experiments for the photolysis of caged compounds. In the peptidergic cells of the pituitary gland, as well as cultured PC12 cells, ultra-violet light was found to produce changes in a number of membrane properties. Light of sufficient intensity to produce rapid photolysis of commonly used caged compounds induced changes in K+ and Ca2+ current, as well as changes in membrane capacitance. All responses to light showed a rapid timecourse, activating in a few ms and decaying within 10-50 ms after illumination ended. Experiments with radical scavengers and with inhibitors of cytochrome p450 and phospholipase A2 failed to block the light responses. These rapid responses to light emphasize that experiments employing ultra-violet light in the photorelease of physiological and pharmacological agents require special care for control of light artifacts.

Production and characterization of monoclonal antibodies against Tal1 oncoprotein

TAL1 (or SCL) oncogene functions as a transcription regulatory factor that is necessary for the early development of all hematopoietic lineages. Aberrant expression of Tall protein in T cells is the cause of T-cell acute lymphoblastic leukemia (T-ALL) in children. We generated two hybridomas that secreted monoclonal antibodies (MAbs) that reacted strongly with GST-TAL(1-210) but not with GST fusion protein in ELISA assay. These two MAbs, TWN3 and TWN60, recognized TALI oncoprotein expressed in transfected COS-1 cells by Western blotting. In addition, both MAbs were also effective in detecting TAL1 oncoprotein in leukemic cells by immunoprecipitation and immunocytochemistry. Therefore, they should be useful in the studies of Tall protein functions in both hematopoietic development and oncogenesis.

Dopamine D4 receptor mediated inhibition of potassium current in neurohypophysial nerve terminals

Dopamine influences the release of neurohypophysial peptides in vivo. However, the extent to which this effect is caused by a direct dopaminergic action within the neurohypophysis remains unclear. With use of the patch-clamp technique on thin slices of rat posterior pituitary glands, we now provide evidence that dopaminergic agonists inhibit potassium current (IK) in neurohypophysial nerve terminals. Superfusion with the dopamine receptor agonist, (+/-)-2-(N-phenylethyl-N-propyl)-amino-5-hydroxytetralin (PPHT), causes a reversible inhibition of whole-terminal IK under voltage clamp. This effect is concentration-dependent, with a maximal inhibition of 40 +/- 5% and an EC50 of 1.8 +/- 1.0 microM. It can be blocked with either a nonselective D2-like antagonist (100 microM eticlopride) or with the highly selective D4 antagonist, RBI-257 (10 microM). U101958 (a derivative of RBI-257) exhibits agonist activity similar to PPHT. Neither SKF 38393 (a D1/D5 agonist) nor quinpirole (a D2/D3 agonist) had any effect on whole-terminal IK in this preparation. Kinetic analysis demonstrated that the amplitude of both the rapidly and slowly inactivating phases of neurohypophysial IK are reduced by D4 receptor activation. These two separate current components have previously been shown to represent current through two distinct potassium channels, an A-current channel and a high-conductance Ca++-activated K+ channel. Thus, both channel types can be modulated by D4 receptors. This effect is likely to enhance the release of neurohypophysial peptides in vivo.

Membrane excitability and secretion from peptidergic nerve terminals

1. Thin slices of the posterior pituitary can be used as a preparation for the study of biophysical mechanisms underlying neuropeptide secretion. Patch-clamp techniques in this preparation have revealed the properties of ion channels that control the excitability of the nerve terminal membrane and have clarified the relation between Ca2+ and exocytosis. 2. Repetitive electrical activity at high frequencies broadens action potentials to allow more Ca2+ entry and thus enhance exocytosis. Action potential broadening results from the inactivation of a voltage-dependent K+ channel. 3. When repetitive electrical activity is sustained, secretion is depressed. This depression can be attributed in part to action potential failure caused by the opening of a Ca(2+)-activated K+ channel. This channel can be modulated by protein kinases, phosphatases, and G-proteins. 4. The inhibitory neurotransmitter GABA activates a GABAA receptor in the nerve terminal membrane. The gating of the associated Cl- channel depolarizes the membrane slightly to inactivate voltage-gated Na+ channels and block action potential propagation. 5. The response of the nerve terminal GABAA receptor is enhanced by neuroactive steroids and this can potentiate the inhibition of neurosecretion by GABA. The action of neurosteroids at this site could play a role in changes in neuropeptide secretion associated with reproductive transitions. 6. Ca2+ channels in the nerve terminal membrane are inactivated by sustained depolarization and by trains of brief pulses. Ca2+ entry promotes Ca2+ channel inactivation during trains by inhibiting the recovery of Ca2+ channels from inactivation. The inactivation of Ca2+ channels can play a role in defining the optimal frequency and train duration for evoking neuropeptide secretion. 7. Measurements of membrane capacitance in peptidergic nerve terminals have revealed rapid exocytosis and endocytosis evoked by Ca2+ entry through voltage-gated Ca2+ channels. Exocytosis is too rapid to account for the delays in neuropeptide secretion evoked by trains of action potentials. Endocytosis sets in rapidly after exocytosis with a time course comparable to that of the rapid endocytosis observed in nerve terminals at rapid synapses. Our results support the finding in rapid synaptic nerve terminals that endocytosis is inhibited by intracellular Ca2+. Multiple pools of vesicles were revealed, and these pools may reflect different stages in the mobilization and release of neuropeptide.

The differential transforming activities of Tal1 oncoproteins

TAL1 (Or SCL) oncogene produces both full-length pp42 and truncated pp22 phosphoproteins in T-cell acute lymphoblastic leukemia cells. To investigate the transforming properties of these two oncoproteins, permanent transfected NIH3T3 cell lines were generated that constitutively express either pp42 or pp22. Both cell lines exhibited similar morphology as parental NIH3T3 cells. However, they showed differential anchorage independent growth in soft-agar. The clonogenicity of pp22 expressing cells was ten folds higher than that of pp42 expressing cells. This result might implicate the differential transformation potential of the two Tal1 oncoproteins.

Aplasia cutis congenita: report of one case

We present a female newborn with a skin defect on the vertex. Aplasia cutis congenita was diagnosed. No associated anomaly was found. There was no family or drug history noted. At one-year follow-up, the lesion tended to contract and became epithelialized. We report this case and also review the literature, and then we suggest a checklist for aplasia cutis congenita.

Adaptation of Ca(2+)-triggered exocytosis in presynaptic terminals

Rapid increases in Ca2+ concentration, produced by photolysis of caged Ca2+, triggered exocytosis in squid nerve terminals. This exocytosis was transient in nature, decaying with a time constant of approximately 30 ms. The decay could not be explained by a decline in presynaptic Ca2+ concentration, depletion of synaptic vesicles, or desensitization of postsynaptic receptors. Experiments in which Ca2+ was increased either in a series of steps or continuously at different rates suggested that the decay is caused by adaptation of the exocytotic Ca2+ receptor to higher levels of Ca2+. This adjustable sensitivity to Ca2+ represents a novel property of the triggering mechanism that can be used to evaluate molecular models of exocytosis. Adaptation can limit the amount of transmitter released by a nerve terminal and permit the speed of a presynaptic Ca2+ rise to serve as a critical determinant of synaptic efficacy.

Rapid exocytosis and endocytosis in nerve terminals of the rat posterior pituitary

1. Ca(2+)-induced exocytosis and endocytosis were studied by measuring the membrane capacitance of voltage-clamped peptidergic nerve terminals in slices prepared from the rat posterior pituitary. 2. Depolarizing pulses produced rapid increases in capacitance. These increases varied in parallel with Ca2+ current as voltage was varied. Elimination of Ca2+ current blocked depolarization-induced capacitance changes. 3. Depolarization-induced capacitance changes increased with pulse duration. Capacitance changes also increased with integrated Ca2+ influx, but saturated at high levels of Ca2+ entry. This saturation allowed us to estimate a pool size of 190 vesicles, assuming each vesicle has a capacitance of 1 fF. Vesicles from this pool fused with a time constant of 0.43 s. The capacitance change increased with the first power of integrated Ca2+ influx. 4. Experiments with briefer pulses revealed a rapid component of exocytosis comprising a pool of forty vesicles that fuse with a time constant of 14 ms. This rapid process may reflect a final Ca(2+)-regulated triggering step, which is distinct from the slower kinetic step revealed by longer duration pulses. The slower step may reflect a priming of vesicles prior to exocytosis. 5. Depolarization-induced capacitance increases in most cases were followed by a rapid decay in capacitance, reflecting membrane reuptake tightly coupled to exocytosis. A variable amount of rapid endocytosis followed depolarization-induced capacitance increases. The time constant for rapid endocytosis to baseline was 0.44 s. Excess endocytosis was occasionally observed, with capacitance decaying below the pre-stimulus baseline with a time constant of 2.1 s. 6. Rapid endocytosis was slower after pulses that produced greater increases in intracellular Ca2+, consistent with the hypothesis that intracellular Ca2+ inhibits rapid endocytosis. 7. Exocytosis follows depolarization with no detectable delay, indicating that Ca2+ triggers neuropeptide secretion from nerve terminals with kinetics comparable to that observed in other rapidly secreting systems.

The effect of amphotericin B on the K-channel activity of MDCK cells

By using the whole-cell patch technique, it is shown that the total outward current is increased, as a function of time, after the addition of amphotericin B to the bathing solution. The whole-cell current is shown to be primarily a K-channel current by the blockage of this current upon application of TEA to the bathing solution. Single K-channel studies, using the outside-out patch-clamp technique, reveal that the single K-channel opening probability increases by a factor of six after the addition of amphotericin B. In addition, single K-channel voltage dependent studies, using the inside-out patch-clamp technique, demonstrate that this increase in opening probability is due to an increase in the amplitude of Po(v). In contrast to the present belief that amphotericin B simply creates pores in a cell's membrane, these results suggest that amphotericin B can also influence the function of the cell's K-channel proteins.

Oesophageal trauma in patients with spinal cord injury

Oesophageal perforations associated with cervical fractures occur from a variety of injuries. Fractures of the cervical spine, blunt trauma and penetrating injuries such as gunshot wounds, knives and missiles, perforate the cervical oesophagus. This retrospective study consists of 24 patients with an oesophageal perforation and cervical fracture. Motor vehicle accidents were responsible for 54% of the oesophageal perforations. The other oesophageal injuries were related to anterior spine surgery, gunshot wounds and sports-related activities. The clinical features related to these injuries included the obvious signs of an oesophageal perforation as well as fever of unknown origin, leukocytosis and unexplained persistent tachycardia. A variety of techniques was used to establish the diagnosis. All the patients had treatment for the cervical fracture and 20 patients required surgical repair of the oesophagus. The most common oesophageal complications were stricture of the oesophagus (54%) and oesophageal diverticulum (10%). The other complications were atelectasis, pneumonia, tracheobronchitis, pulmonary embolism, cervical osteomyelitis, cervical abscess, mediastinitis, septicemia and cervical fistulae. These patients have a serious life-threatening illness that may be difficult to diagnose and treat.

A quantitative electromyographic index that is independent of the force of contraction

Quantitative EMG has been used to improve the accuracy of the diagnosis of myopathy. Equipment is available commercially that utilizes the Willison method of quantification, but the technique has not been widely used because of the necessity of measuring muscle contraction force. An analysis of the basic parameters of the Willison method of quantification was performed for forces of 10, 20, 40 and 60% of maximum for 16 normal subjects for the deltoid muscle. An index was derived from the basic parameters that is independent of the force of contraction. The index is a standardized value for turns/sec expressed as a logarithm. The index has a mean of 1.171 with a standard error of 0.059 for a sample size of 10 muscle sites. Quantitative EMG can be utilized in routine clinical examinations by applying mild to moderate resisting forces to patients, and the proposed index can be determined graphically. The force applied to patients can be maintained within the range of the forces investigated by estimating the force of contraction, evaluating patient effort and fatigue, and monitoring the parameter of total amplitude per second.