Aerobic or Resistance Exercise, or Both, in Dieting Obese Older Adults.

BACKGROUND: Obesity causes frailty in older adults; however, weight loss might accelerate age-related loss of muscle and bone mass and resultant sarcopenia and osteopenia. METHODS: In this clinical trial involving 160 obese older adults, we evaluated the effectiveness of several exercise modes in reversing frailty and preventing reduction in muscle and bone mass induced by weight loss. Participants were randomly assigned to a weight-management program plus one of three exercise programs - aerobic training, resistance training, or combined aerobic and resistance training - or to a control group (no weight-management or exercise program). The primary outcome was the change in Physical Performance Test score from baseline to 6 months (scores range from 0 to 36 points; higher scores indicate better performance). Secondary outcomes included changes in other frailty measures, body composition, bone mineral density, and physical functions. RESULTS: A total of 141 participants completed the study. The Physical Performance Test score increased more in the combination group than in the aerobic and resistance groups (27.9 to 33.4 points [21% increase] vs. 29.3 to 33.2 points [14% increase] and 28.8 to 32.7 points [14% increase], respectively; P=0.01 and P=0.02 after Bonferroni correction); the scores increased more in all exercise groups than in the control group (P<0.001 for between-group comparisons). Peak oxygen consumption (milliliters per kilogram of body weight per minute) increased more in the combination and aerobic groups (17.2 to 20.3 [17% increase] and 17.6 to 20.9 [18% increase], respectively) than in the resistance group (17.0 to 18.3 [8% increase]) (P<0.001 for both comparisons). Strength increased more in the combination and resistance groups (272 to 320 kg [18% increase] and 288 to 337 kg [19% increase], respectively) than in the aerobic group (265 to 270 kg [4% increase]) (P<0.001 for both comparisons). Body weight decreased by 9% in all exercise groups but did not change significantly in the control group. Lean mass decreased less in the combination and resistance groups than in the aerobic group (56.5 to 54.8 kg [3% decrease] and 58.1 to 57.1 kg [2% decrease], respectively, vs. 55.0 to 52.3 kg [5% decrease]), as did bone mineral density at the total hip (grams per square centimeter; 1.010 to 0.996 [1% decrease] and 1.047 to 1.041 [0.5% decrease], respectively, vs. 1.018 to 0.991 [3% decrease]) (P<0.05 for all comparisons). Exercise-related adverse events included musculoskeletal injuries. CONCLUSIONS: Of the methods tested, weight loss plus combined aerobic and resistance exercise was the most effective in improving functional status of obese older adults. (Funded by the National Institutes of Health; LITOE ClinicalTrials.gov number, NCT01065636 .).

Shoulder Electromyography Measurements During Activities of Daily Living and Routine Rehabilitation Exercises.

Study Design Controlled laboratory study. Background The activity of the rotator cuff muscles has not previously been measured with indwelling electromyography (EMG) comparing ambulation and other movements. Knowledge of the relative contribution of these muscles during various tasks may help to guide rehabilitation progression. Objective To measure activity of the rotator cuff muscles and other shoulder muscles during normal ambulation, shirt and sling donning and doffing, and rehabilitation tasks commonly performed after rotator cuff surgery. Methods In 28 volunteers (15 men, 13 women; mean age, 32.2 years), indwelling EMG activity was measured in the supraspinatus, infraspinatus, teres minor, and subscapularis muscles during various tasks; and surface EMG activity was measured in the middle deltoid, biceps, and upper trapezius muscles. Results Using median EMG activity, in general, donning and doffing a shirt or sling recruited the rotator cuff muscles more than the other 7 tasks tested. Self-ranging motion using pulleys, especially in the scapular plane, was also consistently associated with greater recruitment of the shoulder muscles. Pendulum exercises, passive range of motion by a physical therapist, and self-ranging motion with a dowel recruited the shoulder muscles to a lesser extent. Conclusion Our results demonstrate that rehabilitation tasks such as pendulum exercises, passive range of motion by a physical therapist, and self-ranging motion with a dowel show low EMG activity, whereas pulleys in the sagittal plane and scapular plane show greater activity. Scapular plane activity was consistently higher than sagittal plane activity. Of all the tasks assessed, ambulation without a sling and donning and doffing a sling and a shirt consistently showed the highest activity. J Orthop Sports Phys Ther 2016;46(5):375-383. Epub 6 Apr 2016. doi:10.2519/jospt.2016.6090.

Therapeutic antibody targeting of Notch1 in T-acute lymphoblastic leukemia xenografts.

T-acute lymphoblastic leukemia (T-ALL) is characterized by several genetic alterations and poor prognosis in about 20-25% of patients. Notably, about 60% of T-ALL shows increased Notch1 activity, due to activating NOTCH1 mutations or alterations in the FBW7 gene, which confer to the cell a strong growth advantage. Therapeutic targeting of Notch signaling could be clinically relevant, especially for chemotherapy refractory patients. This study investigated the therapeutic efficacy of a novel anti-Notch1 monoclonal antibody by taking advantage of a collection of pediatric T-ALL engrafted systemically in NOD/SCID mice and genetically characterized with respect to NOTCH1/FBW7 mutations. Anti-Notch1 treatment greatly delayed engraftment of T-ALL cells bearing Notch1 mutations, including samples derived from poor responders or relapsed patients. Notably, the therapeutic efficacy of anti-Notch1 therapy was significantly enhanced in combination with dexamethasone. Anti-Notch1 treatment increased T-ALL cell apoptosis, decreased proliferation and caused strong inhibitory effects on Notch-target genes expression along with complex modulations of gene expression profiles involving cell metabolism. Serial transplantation experiments suggested that anti-Notch1 therapy could compromise leukemia-initiating cell functions. These results show therapeutic efficacy of Notch1 blockade for T-ALL, highlight the potential of combination with dexamethasone and identify surrogate biomarkers of the therapeutic response.

Functional expression of KCNQ (Kv7) channels in guinea pig bladder smooth muscle and their contribution to spontaneous activity.

BACKGROUND AND PURPOSE: The aim of the study was to determine whether KCNQ channels are functionally expressed in bladder smooth muscle cells (SMC) and to investigate their physiological significance in bladder contractility. EXPERIMENTAL APPROACH: KCNQ channels were examined at the genetic, protein, cellular and tissue level in guinea pig bladder smooth muscle using RT-PCR, immunofluorescence, patch-clamp electrophysiology, calcium imaging, detrusor strip myography, and a panel of KCNQ activators and inhibitors. KEY RESULTS: KCNQ subtypes 1-5 are expressed in bladder detrusor smooth muscle. Detrusor strips typically displayed TTX-insensitive myogenic spontaneous contractions that were increased in amplitude by the KCNQ channel inhibitors XE991, linopirdine or chromanol 293B. Contractility was inhibited by the KCNQ channel activators flupirtine or meclofenamic acid (MFA). The frequency of Ca²âº-oscillations in SMC contained within bladder tissue sheets was increased by XE991. Outward currents in dispersed bladder SMC, recorded under conditions where BK and KATP currents were minimal, were significantly reduced by XE991, linopirdine, or chromanol, and enhanced by flupirtine or MFA. XE991 depolarized the cell membrane and could evoke transient depolarizations in quiescent cells. Flupirtine (20 µM) hyperpolarized the cell membrane with a simultaneous cessation of any spontaneous electrical activity. CONCLUSIONS AND IMPLICATIONS: These novel findings reveal the role of KCNQ currents in the regulation of the resting membrane potential of detrusor SMC and their important physiological function in the control of spontaneous contractility in the guinea pig bladder.

Absorption of hydrocortisone acetate in human connective tissue using phonophoresis.

BACKGROUND: Therapeutic ultrasound to drive medication (phonophoresis) has been a mainstay in physical therapy. The most common drug used in phonophoresis is hydrocortisone acetate (HA). A number of studies have been done examining phonophoresis in the delivery of HA through the skin to underlying tissues; however, a study has never been done examining the absorption of HA using phonophoresis on human connective tissue. HYPOTHESIS: Phonophoresis will facilitate the transmission of HA in human connective tissue. STUDY DESIGN: Randomized controlled study. METHODS: Twenty-one patients undergoing anterior cruciate ligament reconstruction surgery were randomly assigned to either a sham or true phonophoresis treatment group. The latter group received 6 minutes of 10% HA ultrasound at a point consistent with the gastrocnemius slip of the semitendinosis tendon (treatment site). The sham group received 6 minutes of 10% HA ultrasound to the same area, but the ultrasound was not turned on. The slip and a sample of the distal attachment of the tendon (control) were removed. Samples were analyzed for HA levels. RESULTS: Although the mean and median levels of HA found at the treatment site were greater than those of the control site (means, 34.1 vs 22.9 parts per billion; medians, 7 vs 0 parts per billion), the levels of HA found at the treatment site were not significantly greater than those at the control site (P = 0.15). There were no statistically significant differences between the true and sham phonophoresis groups in HA levels (P = 0.80) nor in age, sex, or skin thickness. CONCLUSION: Phonophoresis does not appear to facilitate the absorption of HA in connective tissue when compared with simple absorption (sham). CLINICAL RELEVANCE: Phonophoresis does not appear to enhance the transmission of HA in human connective tissue; therefore, use of phonophoresis should be reconsidered in inflammatory conditions.

Treatment with the Kv7 potassium channel activator flupirtine is beneficial in two independent mouse models of pulmonary hypertension.

BACKGROUND AND PURPOSE: Voltage-gated potassium (K(v)) channels contribute to resting membrane potential in pulmonary artery smooth muscle cells and are down regulated in patients with pulmonary arterial hypertension (PAH) and a contribution from K(v)7 channels has been recently proposed. We investigated the effect of the K(v)7 channel activator, flupirtine, on PAH in two independent mouse models: PAH induced by hypoxia and spontaneous PAH in mice over-expressing the 5-HT transporter (SERT(+) mice). EXPERIMENTAL APPROACH: Right ventricular pressure was assessed in vivo in mice chronically treated with flupirtine (30 mg.kg(-1).day(-1)). In separate in vitro experiments, pulmonary arteries from untreated mice were mounted in a wire myograph. Relaxations to acute administration of flupirtine and contractions to K(v) channel blocking drugs, including the K(v)7 channel blocker linopirdine, were measured. KEY RESULTS: In wild-type (WT) mice, hypoxia increased right ventricular pressure, pulmonary vascular remodelling and right ventricular hypertrophy. These effects were attenuated by flupirtine, which also attenuated these indices of PAH in SERT(+) mice. In the in vitro experiments, flupirtine induced a potent relaxant response in arteries from untreated WT and SERT(+) mice. The relaxation was fully reversed by linopirdine, which potently contracted mouse pulmonary arteries while other K(v) channel blockers did not. CONCLUSIONS AND IMPLICATIONS: Flupirtine significantly attenuated development of chronic hypoxia-induced PAH in mice and reversed established PAH in SERT(+) mice, apparently via K(v)7 channel activation. These results provide the first direct evidence that drugs activating K(v)7 channels may be of benefit in the treatment of PAH with different aetiologies.

Absorption of dexamethasone sodium phosphate in human connective tissue using iontophoresis.

BACKGROUND: Iontophoresis ostensibly facilitates the delivery of medications through the skin to underlying tissues using a direct electrical current. Dexamethasone is the most commonly used medication with iontophoresis to treat a variety of connective tissue disorders. HYPOTHESIS: Iontophoresis will facilitate the absorption of dexamethasone into connective tissue compared with diffusion. STUDY DESIGN: Controlled laboratory study. METHODS: Twenty-nine adults undergoing anterior cruciate ligament reconstructive surgery using the semitendinosus/gracilis autograft were randomly assigned to either a true iontophoresis (TI) or sham iontophoresis (SI). In the TI group, a 40-mA/min dose of iontophoresis using a 0.4% (4 mg/mL) solution of dexamethasone was used targeting the semitendinosus tendon just before surgery. The SI group underwent the same treatment, but the machine was not turned on. Tissue was extracted within 4 hours of treatment and analyzed for dexamethasone. In addition, 2 control samples were sent to the laboratory for analysis. RESULTS: There was a statistically significant difference in dexamethasone concentrations between the groups (P = .0216). Of the 16 samples in the TI group, 8 had measurable amounts of dexamethasone, with an average concentration of 2.906 ng/g of tendon tissue. In the SI group, 1 of the 13 samples had measurable amounts of dexamethasone with an average concentration of 0.205 ng/g of tendon tissue. The control samples contained no dexamethasone. CONCLUSION: Iontophoresis facilitates the transmission of dexamethasone to connective tissues in humans. CLINICAL RELEVANCE: Iontophoresis can deliver dexamethasone to connective tissues in humans.

A novel form of resistance in rice to the angiosperm parasite Striga hermonthica.

The root hemiparasitic weed Striga hermonthica is a serious constraint to grain production of economically important cereals in sub-Saharan Africa. Breeding for parasite resistance in cereals is widely recognized as the most sustainable form of long-term control; however, advances have been limited owing to a lack of cereal germplasm demonstrating postattachment resistance to Striga. Here, we identify a cultivar of rice (Nipponbare) that exhibits strong postattachment resistance to S. hermonthica; the parasite penetrates the host root cortex but does not form parasite-host xylem-xylem connections. In order to identify the genomic regions contributing to this resistance, a mapping population of backcross inbred lines between the resistant (Nipponbare) and susceptible (Kasalath) parents were evaluated for resistance to S. hermonthica. Composite interval mapping located seven putative quantitative trait loci (QTL) explaining 31% of the overall phenotypic variance; a second, independent, screen confirmed four of these QTL. Relative to the parental lines, allelic substitutions at these QTL altered the phenotype by at least 0.5 of a phenotypic standard deviation. Thus, they should be regarded as major genes and are likely to be useful in breeding programmes to enhance host resistance.

Immune response in silico (IRIS): immune-specific genes identified from a compendium of microarray expression data.

Immune cell-specific expression is one indication of the importance of a gene's role in the immune response. We have compiled a compendium of microarray expression data for virtually all human genes from six key immune cell types and their activated and differentiated states. Immune Response In Silico (IRIS) is a collection of genes that have been selected for specific expression in immune cells. The expression pattern of IRIS genes recapitulates the phylogeny of immune cells in terms of the lineages of their differentiation. Gene Ontology assignments for IRIS genes reveal significant involvement in inflammation and immunity. Genes encoding CD antigens, cytokines, integrins and many other gene families playing key roles in the immune response are highly represented. IRIS also includes proteins of unknown function and expressed sequence tags that may not represent genes. The predicted cellular localization of IRIS proteins is evenly distributed between cell surface and intracellular compartments, indicating that immune specificity is important at many points in the signaling pathways of the immune response. IRIS provides a resource for further investigation into the function of the immune system and immune diseases.

Two-pore domain K channel, TASK-1, in pulmonary artery smooth muscle cells.

Pulmonary vascular tone is strongly influenced by the resting membrane potential of smooth muscle cells, depolarization promoting Ca2+ influx, and contraction. The resting potential is determined largely by the activity of K+-selective ion channels, the molecular nature of which has been debated for some time. In this study, we provide strong evidence that the two-pore domain K+ channel, TASK-1, mediates a noninactivating, background K+ current (IKN), which sets the resting membrane potential in rabbit pulmonary artery smooth muscle cells (PASMCs). TASK-1 mRNA was found to be present in PASMCs, and the membranes of PASMCs contained TASK-1 protein. Both IKN and the resting potential were found to be exquisitely sensitive to extracellular pH, acidosis inhibiting the current and causing depolarization. Moreover, IKN and the resting potential were enhanced by halothane (1 mmol/L), inhibited by Zn2+ (100 to 200 micromol/L) and anandamide (10 micromol/L), but insensitive to cytoplasmic Ca2+. These properties are all diagnostic of TASK-1 channels and add to previously identified features of IKN that are shared with TASK-1, such as inhibition by hypoxia, low sensitivity to 4-aminopyridine and quinine and insensitivity to tetraethylammonium ions. It is therefore concluded that TASK-1 channels are major contributors to the resting potential in pulmonary artery smooth muscle. They are likely to play an important role in mediating pulmonary vascular responses to changes in extracellular pH, and they could be responsible for the modulatory effects of pH on hypoxic pulmonary vasoconstriction.

Two-photon microscopy of fura-2-loaded cardiac myocytes with an all-solid-state tunable and visible femtosecond laser source.

We report a robust and reliable platform source for visible-wavelength multiphoton microscopy that is based on nonlinear optical methods. We demonstrate a synchronously pumped, singly resonant optical parametric oscillator with simultaneous intracavity third-order quasi-phase matching in a single crystal that generates continuously tunable, visible, and femtosecond-pulsed radiation. The application of the system is demonstrated by two-photon laser-scanning fluorescence microscopy of rabbit cardiac myocytes loaded with the fluorescent Ca2+ indicator fura-2.

Novel sources of resistance to Striga hermonthica in Tripsacum dactyloides, a wild relative of maize.

• The parasitic weed Striga hermonthica lowers cereal yield in small-holder farms in Africa. Complete resistance in maize to S. hermonthica infection has not been identified. A valuable source of resistance to S. hermonthica may lie in the genetic potential of wild germplasm. • The susceptibility of a wild relative of maize, Tripsacum dactyloides and a Zea mays-T. dactyloides hybrid to S. hermonthica infection was determined. Striga hermonthica development was arrested after attachment to T. dactyloides. Vascular continuity was established between parasite and host but there was poor primary haustorial tissue differentiation on T. dactyloides compared with Z. mays. Partial resistance was inherited in the hybrid. • Striga hermonthica attached to Z. mays was manipulated such that different secondary haustoria could attach to different hosts. Secondary haustoria formation was inhibited on T. dactyloides, moreover, subsequent haustoria formation on Z. mays was also impaired. • Results suggest that T. dactyloides produces a signal that inhibits haustorial development: this signal may be mobile within the parasite haustorial root system.

Regional variation in P2 receptor expression in the rat pulmonary arterial circulation.

The P2 receptors that mediate contraction of the rat isolated small (SPA, 200-500 micro m i.d.) and large (LPA, 1-1.5 mM i.d.) intrapulmonary arteries were characterized. 2 In endothelium-denuded vessels the contractile order of potency was alpha,beta-methyleneATP (alpha,beta-meATP)>>UDP=UTP=ATP=2-methylthioATP>ADP in the SPA and alpha,beta-meATP=UTP>or=UDP>2-methylthioATP, ATP>>ADP in the LPA. alpha,beta-meATP, 2-methylthioATP and ATP had significantly greater effects in the SPA than the LPA (P<0.001), but there was no difference in the potency of UTP or UDP between the vessels. 3 In the SPA, P2X1 receptor desensitisation by alpha,beta-meATP (100 microM) inhibited contractions to alpha,beta-meATP (10 nM-300 microM), but not those to UTP or UDP (100 nM-300 microM). In the LPA, prolonged exposure to alpha,beta-meATP (100 microM) did not desensitize P2X receptors. 4 Pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS), suramin and reactive blue 2 (RB2) (30-300 microM) inhibited contractions evoked by alpha,beta-meATP. UTP and UDP were potentiated by PPADS, unaffected by RB2 and inhibited, but not abolished by suramin. 1 and 3 mM suramin produced no further inhibition, indicating suramin-resistant components in the responses to UTP and UDP. 5 Thus, both P2X and P2Y receptors mediate contraction of rat large and small intrapulmonary arteries. P2Y agonist potency and sensitivity to antagonists were similar in small and large vessels, but P2X agonists were more potent in small arteries. This indicates differential expression of P2X, but not P2Y receptors along the pulmonary arterial tree.

Saline containing phosphatidylcholine liposomes possess the ability to restore endothelial function damaged resulting from gamma-irradiation.

The protective action of passive saline filled ("empty") phosphatidylcholine liposomes (PCL) on endothelial function was examined in thoracic aortas obtained from gamma irradiated (6 Gy) Chinchilla rabbits, and then verified in experiments on non-anesthetized and anesthetized rats. Acetylcholine (ACh)-induced vascular relaxant responses in isolated vascular tissues rats were used as the test of endothelial integrity and its functional ability. It was shown that when added to the bath solution (100 microg/ml), PCL effectively restored endothelium-dependent ACh relaxations of isolated vascular rings damaged resulting from gamma-irradiation but had no effect on endothelium-independent vascular responses to therapeutic nitric oxide (NO) donors. The liposomes were also without protective effect when injected to the rabbits intraperitoneally (30 mg/kg) 1 hour before irradiation. In contrast, PCL, being injected at the same dose 1 hour after radiation impact, promote normalization of both endothelium-dependent vascular responses to ACh and nitric oxide (NO) donors. PCL restored also the sensitivity of vascular tissues to authentic NO (aqueous NO solution) that was surprisingly increased after irradiation, and normalized relationship between ACh-stimulated NO release and relaxant response amplitudes in irradiated aortas. Experiments on non-anesthetized and anesthetized rats demonstrated that irradiation led to significant elevation in the level of arterial blood pressure without any changes in cardiac contractility. PCL administration (25 mg/kg, i.v.) effectively normalized an increased arterial blood pressure in irradiated animals. In conclusion, it appears that PCL due to its ability to normalize NO-dependent vascular tone control mechanisms might be worthwhile therapeutic approach in case of ionizing irradiation accident. These result support the concept that the depression of endothelium-dependent vascular responses after irradiation may be result of decreased NO bioavailability due to its conversion to less potent vasodilators during irradiation-induced oxidative attack.

Forced expression of murine IL-17E induces growth retardation, jaundice, a Th2-biased response, and multiorgan inflammation in mice.

IL-17 is a proinflammatory cytokine, and its in vivo expression induces neutrophilia in mice. IL-17E is a recently described member of an emerging family of IL-17-related cytokines. IL-17E has been shown to bind IL-17Rh1, a protein distantly related to the IL-17R, suggesting that IL-17E probably possesses unique biological functions. In this study, we have identified the murine ortholog of IL-17E and developed transgenic mice to characterize its actions in vivo. Biological consequences of overexpression of murine (m)IL-17E, both unique to IL-17E and similar to IL-17, were revealed. Exposure to mIL-17E resulted in a Th2-biased response, characterized by eosinophilia, increased serum IgE and IgG1, and a Th2 cytokine profile including elevated serum levels of IL-13 and IL-5 and elevated gene expression of IL-4, IL-5, IL-10, and IL-13 was observed in many tissues. Increased gene expression of IFN-gamma in several tissues and elevated serum TNF-alpha were also noted. In addition, IL-17E induces G-CSF production in vitro and mIL-17E-transgenic mice had increased serum G-CSF and exhibit neutrophilia, a property shared by IL-17. Moreover, exposure to mIL-17E elicited pathological changes in multiple tissues, particularly liver, heart, and lungs, characterized by mixed inflammatory cell infiltration, epithelial hyperplasia, and hypertrophy. Taken together, these findings suggest that IL-17E is a unique pleiotropic cytokine and may be an important mediator of inflammatory and immune responses.

Store-operated channels mediate Ca(2+) influx and contraction in rat pulmonary artery.

Cation channels activated by Ca(2+) store depletion have been proposed to mediate Ca(2+) influx in vascular smooth muscle cells. The aim of this study was to determine if store-operated channels have a functional role in pulmonary artery smooth muscle cells (PASMCs). In intact rat pulmonary artery rings, cyclopiazonic acid (CPA) produced a sustained contraction that was resistant to inhibition by nifedipine, but abolished in Ca(2+)-free solution and 50% blocked in the presence of 6 micromol/L Cd(2+), 10 micromol/L Ni(2+), 600 micromol/L La(3+), and 7 micromol/L SKF96365. In freshly isolated PASMCs loaded with fura-2, CPA increased the intracellular Ca(2+) concentration by stimulating dihydropyridine-resistant Ca(2+) influx, which was approximately 50% blocked by 10 micromol/L Ni(2+) and 7 micromol/L SKF96365. In perforated-patch recordings, CPA activated a sustained inward current at negative membrane potentials, which persisted in cells dialyzed with BAPTA, showed a near linear dependence on membrane potential when Cs(+) was the main intracellular cation, and was blocked by Ni(2+), Cd(2+), and SKF96365 at concentrations preventing contraction. The current showed a bimodal dependence on extracellular Ca(2+), being enhanced 2-fold in the absence of Ca(2+) and around 10-fold on reducing Ca from 1.8 to 0.2 mmol/L. RT-PCR revealed the expression of Trp1, Trp3, Trp4, Trp5, and Trp6 mRNA, whereas immunostaining identified Trp1, Trp3, Trp4, and Trp6 channel proteins in isolated PASMCs. At least one of these subunits may contribute to cation channels in PASMCs, which are activated by store depletion to bring about Ca(2+) influx and contraction.

Mechanisms of hydralazine induced vasodilation in rabbit aorta and pulmonary artery.

1. The directly acting vasodilator hydralazine has been proposed to act at an intracellular site in vascular smooth muscle to inhibit Ca(2+) release. 2. This study investigated the mechanism of action of hydralazine on rabbit aorta and pulmonary artery by comparing its effects on the tension generated by intact and beta-escin permeabilized vessels and on the cytoplasmic Ca(2+) concentration, membrane potential and K(+) currents of isolated vascular smooth muscle cells. 3. Hydralazine relaxed pulmonary artery and aorta with similar potency. It was equally effective at inhibiting phasic and tonic contractions evoked by phenylephrine in intact vessels and contractions evoked by inositol 1,4,5 trisphosphate (IP(3)) in permeabilized vessels. 4. Hydralazine inhibited the contraction of permeabilized vessels and the increase in smooth muscle cell Ca(2+) concentration evoked by caffeine with similar concentration dependence, but with lower potency than its effect on IP(3) contractions. 5. Hydralazine had no effect on the relationship between Ca(2+) concentration and force generation in permeabilized vessels, but it slowed the rate at which maximal force was developed before, but not after, destroying sarcoplasmic reticulum function with the calcium ionophore, ionomycin. 6. Hydralazine had no effect on membrane potential or the amplitudes of K(+) currents recorded from isolated smooth muscle cells over the concentration range causing relaxation of intact vessels. 7. The results suggest that the main action of hydralazine is to inhibit the IP(3)-induced release of Ca(2+) from the sarcoplasmic reticulum in vascular smooth muscle cells.

IL-17s adopt a cystine knot fold: structure and activity of a novel cytokine, IL-17F, and implications for receptor binding.

The proinflammatory cytokine interleukin 17 (IL-17) is the founding member of a family of secreted proteins that elicit potent cellular responses. We report a novel human IL-17 homolog, IL-17F, and show that it is expressed by activated T cells, can stimulate production of other cytokines such as IL-6, IL-8 and granulocyte colony-stimulating factor, and can regulate cartilage matrix turnover. Unexpectedly, the crystal structure of IL-17F reveals that IL-17 family members adopt a monomer fold typical of cystine knot growth factors, despite lacking the disulfide responsible for defining the canonical "knot" structure. IL-17F dimerizes in a parallel manner like neurotrophins, and features an unusually large cavity on its surface. Remarkably, this cavity is located in precisely the same position where nerve growth factor binds its high affinity receptor, TrkA, suggesting further parallels between IL-17s and neurotrophins with respect to receptor recognition.

Identification of an angiogenic mitogen selective for endocrine gland endothelium.

The known endothelial mitogens stimulate growth of vascular endothelial cells without regard to their tissue of origin. Here we report a growth factor that is expressed largely in one type of tissue and acts selectively on one type of endothelium. This molecule, called endocrine-gland-derived vascular endothelial growth factor (EG-VEGF), induced proliferation, migration and fenestration (the formation of membrane discontinuities) in capillary endothelial cells derived from endocrine glands. However, EG-VEGF had little or no effect on a variety of other endothelial and non-endothelial cell types tested. Similar to VEGF, EG-VEGF possesses a HIF-1 binding site, and its expression is induced by hypoxia. Both EG-VEGF and VEGF resulted in extensive angiogenesis and cyst formation when delivered in the ovary. However, unlike VEGF, EG-VEGF failed to promote angiogenesis in the cornea or skeletal muscle. Expression of human EG-VEGF messenger RNA is restricted to the steroidogenic glands, ovary, testis, adrenal and placenta and is often complementary to the expression of VEGF, suggesting that these molecules function in a coordinated manner. EG-VEGF is an example of a class of highly specific mitogens that act to regulate proliferation and differentiation of the vascular endothelium in a tissue-specific manner.

IL-17E, a novel proinflammatory ligand for the IL-17 receptor homolog IL-17Rh1.

We report identification of interleukin (IL)-17E, a novel member of the IL-17 family of cytokines. IL-17E is a ligand for the recently identified protein termed EVI27/IL-17BR, which we term IL-17 receptor homolog 1 (IL-17Rh1) in light of the multiple reported ligand-receptor relationships. Murine EVI27 was identified through its location at a common site of retroviral integration in BXH2 murine myeloid leukemias. IL-17Rh1 shows highest level expression in kidney with moderate expression in multiple other organs, whereas IL-17E mRNA was detected at very low levels in several peripheral tissues. IL-17E induces activation of NF-kappaB and stimulates production of the proinflammatory chemokine IL-8.