Repeated oral administration of capsaicin increases anxiety-like behaviours with prolonged stress-response in rats

This study was conducted to examine the psycho-emotional effects of repeated oral exposure to capsaicin, the principal active component of chili peppers. Each rat received 1 mL of 0.02% capsaicin into its oral cavity daily, and was subjected to behavioural tests following 10 daily administrations of capsaicin. Stereotypy counts and rostral grooming were significantly increased, and caudal grooming decreased, in capsaicin-treated rats during the ambulatory activity test. In elevated plus maze test, not only the time spent in open arms but also the percent arm entry into open arms was reduced in capsaicin-treated rats compared with control rats. In forced swim test, although swimming duration was decreased, struggling increased in the capsaicin group, immobility duration did not differ between the groups. Repeated oral capsaicin did not affect the basal levels of plasma corticosterone; however, the stress-induced elevation of plasma corticosterone was prolonged in capsaicin treated rats. Oral capsaicin exposure significantly increased c-Fos expression not only in the nucleus tractus of solitarius but also in the paraventricular nucleus. Results suggest that repeated oral exposure to capsaicin increases anxiety-like behaviours in rats, and dysfunction of the hypothalamic-pituitary-adrenal axis may play a role in its pathophysiology.     

Two new species (Gustavia johnclarkii and G. hubbardiorum) and other contributions to the systematics of Gustavia (Lecythidaceae)

Gustavia johnclarkii and G. hubbardiorum, two new species from the wet forests of northwestern and Amazonian Ecuador, are described and illustrated. In addition, the two subspecies of both G. speciosa and G. macarenensis are elevated to species, and the new combination Gustavia paucisperma is provided. A justification for these changes is presented.     

Proliferation of Murine Midbrain Neural Stem Cells Depends upon an Endogenous Sonic Hedgehog (Shh) Source

The Sonic Hedgehog (Shh) pathway is responsible for critical patterning events early in development and for regulating the delicate balance between proliferation and differentiation in the developing and adult vertebrate brain. Currently, our knowledge of the potential role of Shh in regulating neural stem cells (NSC) is largely derived from analyses of the mammalian forebrain, but for dorsal midbrain development it is mostly unknown. For a detailed understanding of the role of Shh pathway for midbrain development in vivo, we took advantage of mouse embryos with cell autonomously activated Hedgehog (Hh) signaling in a conditional Patched 1 (Ptc1) mutant mouse model. This animal model shows an extensive embryonic tectal hypertrophy as a result of Hh pathway activation. In order to reveal the cellular and molecular origin of this in vivo phenotype, we established a novel culture system to evaluate neurospheres (nsps) viability, proliferation and differentiation. By recreating the three-dimensional (3-D) microenvironment we highlight the pivotal role of endogenous Shh in maintaining the stem cell potential of tectal radial glial cells (RGC) and progenitors by modulating their Ptc1 expression. We demonstrate that during late embryogenesis Shh enhances proliferation of NSC, whereas blockage of endogenous Shh signaling using cyclopamine, a potent Hh pathway inhibitor, produces the opposite effect. We propose that canonical Shh signaling plays a central role in the control of NSC behavior in the developing dorsal midbrain by acting as a niche factor by partially mediating the response of NSC to epidermal growth factor (EGF) and fibroblast growth factor (FGF) signaling. We conclude that endogenous Shh signaling is a critical mechanism regulating the proliferation of stem cell lineages in the embryonic dorsal tissue.     

Diversity and trophic structure of insects associated with grains of three maize landraces in San Agustín Loxicha,Oaxaca, Mexico

Diversity and trophic structure of grain insect communities were examined in Olotillo, Nal‐Tel and Comiteco maize landraces cultivated within a milpa agroecosystem by Zapotec ethnic groups in Mexico. Higher insect diversity was expected in Olotillo, whose cultivation comprises a wide variety of agroecosystems, and low insect abundance in Nal‐Tel with small grains and thick testa. Forty Olotillo cobs were collected at low, medium and high elevations, and 40 each of Nal‐Tel at low elevation and Comiteco at high elevation. Cobs were monitored for 30 days under controlled laboratory conditions until all insects emerged. Thickness of testa of 400 grains from each landrace was measured. Community composition and trophic structure were described and standard diversity indices were estimated. A total of 9,708 insects, corresponding to five orders, 24 families and 36 species, were recorded, with six species not previously reported in this region. Insect guilds were composed of 70% phytophages, 22% parasitoids and 8% predators. Species richness was S = 27, 16 and 8 in Olotillo, Comiteco and Nal‐Tel, respectively. Nal‐Tel and Olotillo had the highest diversity index values (H′ = 1.32 and 1.2, respectively) and no significant differences; Comiteco had the lowest value (H′ = 0.65) and differed significantly from the other landraces. Comiteco and Olotillo, which have large grains and thin testa, showed higher insect abundance than Nal‐Tel, which has small grains and thick testa and showed lower abundance. Results support our hypotheses and highlight the role of traditional crop management in insect agrobiodiversity maintenance and conservation.     

Studies in the Capparaceae XXX: Capparicordis, a new genus from the neotropics

Capparicordis, genus novum is established for Capparicordis crotonoides, C. tweediana, and C. yunckeri, all new combinations here established for three former species of the New World Capparis, Sect. Colicodendron. The first two are xerophytic shrubs or small trees easily separated by flower color, and the last is a grapple-hook scrambler of which flowers are unknown. They have allopatric distributions: C. crotonoides is found in Peru and Ecuador west of the Andes, C. tweediana from Argentina to Bolivia and Paraguay east of the Andes, whereas C. yunckeri is a rare, local endemic from the arid woodlands near Coyoles in northern Honduras. All have stellate pubescence, broadly cordate to subrotund-reniform leaves with (sub)palmate venation at the leaf blade base; a valvate calyx with closed aestivation; baccate subspherical fruits dehiscent by 2–4 valves (indehiscent in C. yunckeri?); cochleate-reniform seeds surrounded by a pulp-derived sarcotesta densely infiltrated by unbranched, unicellular hairs from the testa; and snow-white embryos. Capparicordis crotonoides has n=8 chromosomes.     

An arachidonic acid generation/export system involved in the regulation of cholesterol transport in mitochondria of steroidogenic cells

Recent studies demonstrated the importance of the mitochondrial ATP in the regulation of a novel long-chain fatty acid generation/export system in mitochondria of diabetic rat heart. In steroidogenic systems, mitochondrial ATP and intramitochondrial arachidonic acid (AA) generation are important for steroidogenesis. Here, we report that mitochondrial ATP is necessary for the generation and export of AA, steroid production and steroidogenic acute regulatory protein induction supported by cyclic 3'-5'-adenosine monophosphate in steroidogenic cells. These results demonstrate that ATP depletion affects AA export and provide new evidence of the existence of the fatty acid generation and export system involved in mitochondrial cholesterol transport.     

Intrinsically bent DNA in the promoter regions of the yeast GAAL1-10 and GAL80 genes

Circular permutation analysis has detected fairly strong sites of intrinsic DNA bending on the promoter regions of the yeast GAL1-10 and GAL80 genes. These bends lie in functionally suggestive locations. On the promoter of the GAL1-10 structural genes, strong bends bracket nucleosome B, which lies between the UAS(G) and the GAL1 TATA. These intrinsic bends could help position nucleosome B. Nucleosome B plus two other promoter nucleosomes protect the TATA and start site elements in the inactive state of expression but are completely disrupted (removed) when GAL1-10 expression is induced. The strongest intrinsic bend ( approximately 70 degrees ) lies at the downstream edge of nucleosome B; this places it approximately 30 base pairs upstream of the GAL1 TATA, a position that could allow it to be involved in GAL1 activation in several ways, including the recruitment of a yeast HMG protein that is required for the normally robust level of GAL1 expression in the induced state (Paull, T., Carey, M., and Johnson, R. (1996) Genes Dev. 10, 2769-2781). On the regulatory gene GAL80, the single bend lies in the non-nucleosomal hypersensitive region, between a GAL80-specific far upstream promoter element and the more gene-proximal promoter elements. GAL80 promoter region nucleosomes contain no intrinsically bent DNA.     

Escherichia coli Heat-Stable Enterotoxin Mediates Na+/H+ Exchanger 4 Inhibition Involving cAMP in T84 Human Intestinal Epithelial Cells

The enterotoxigenic Escherichia coli strains lead to diarrhoea in humans due to heat-labile and heat-stable (STa) enterotoxins. STa increases Cl^-release in intestinal cells, including the human colonic carcinoma T₈₄ cell line, involving increased cGMP and membrane alkalization due to reduced Na⁺/H⁺ exchangers (NHEs) activity. Since NHEs modulate intracellular pH (pH_i), and NHE1, NHE2, and NHE4 are expressed in T₈₄ cells, we characterized the STa role as modulator of these exchangers. pH_i was assayed by the NH₄Cl pulse technique and measured by fluorescence microscopy in BCECF–preloaded cells. pH_i recovery rate (dpHi/dt) was determined in the absence or presence of 0.25 μmol/L STa (30 minutes), 25 μmol/L HOE-694 (concentration inhibiting NHE1 and NHE2), 500 μmol/L sodium nitroprusside (SNP, spontaneous nitric oxide donor), 100 μmol/L dibutyryl cyclic GMP (db-cGMP), 100 nmol/L H89 (protein kinase A inhibitor), or 10 μmol/L forskolin (adenylyl cyclase activator). cGMP and cAMP were measured in cell extracts by radioimmunoassay, and buffering capacity (ßi) and H⁺ efflux (J _H ⁺) was determined. NHE4 protein abundance was determined by western blotting. STa and HOE-694 caused comparable reduction in dpHi/dt and J _H ⁺ (~63%), without altering basal pH_i (range 7.144–7.172). STa did not alter ßi value in a range of 1.6 pH_i units. The dpHi/dt and J _H ⁺ was almost abolished (~94% inhibition) by STa + HOE-694. STa effect was unaltered by db-cGMP or SNP. However, STa and forskolin increased cAMP level. STa–decreased dpHi/dt and J _H ⁺ was mimicked by forskolin, and STa + HOE-694 effect was abolished by H89. Thus, incubation of T₈₄ cells with STa results in reduced NHE4 activity leading to a lower capacity of pH_i recovery requiring cAMP, but not cGMP. STa effect results in a causal phenomenon (STa/increased cAMP/increased PKA activity/reduced NHE4 activity) ending with intracellular acidification that could have consequences in the gastrointestinal cells function promoting human diarrhoea.     

A species-specific real-time PCR assay for identification of three lichen-forming fungi, Lobaria pulmonaria, Lobaria immixta and Lobaria macaronesica

We present a multiplex real-time PCR assay for the simultaneous identification of three morphologically similar species of lichen-forming fungi, Lobaria pulmonaria, Lobaria immixta and Lobaria macaronesica. Based on TaqMan MGB (minor groove binding) probes targeting the fungal internal transcribed spacer (ITS nrDNA) region, our assay unambiguously identifies known samples from all the three species, thus providing a powerful alternative to the more expensive DNA-sequencing techniques.     

Effects of general,specific and combined warm-up on explosive muscular performance

The purpose of this study was to compare the acute effects of general, specific and combined warm-up (WU) on explosive performance. Healthy male (n = 10) subjects participated in six WU protocols in a crossover randomized study design. Protocols were: passive rest (PR; 15 min of passive rest), running (Run; 5 min of running at 70% of maximum heart rate), stretching (STR; 5 min of static stretching exercise), jumping [Jump; 5 min of jumping exercises – 3x8 countermovement jumps (CMJ) and 3x8 drop jumps from 60 cm (DJ60)], and combined (COM; protocols Run+STR+Jump combined). Immediately before and after each WU, subjects were assessed for explosive concentric-only (i.e. squat jump – SJ), slow stretch-shortening cycle (i.e. CMJ), fast stretch-shortening cycle (i.e. DJ60) and contact time (CT) muscle performance. PR significantly reduced SJ performance (p =0.007). Run increased SJ (p =0.0001) and CMJ (p =0.002). STR increased CMJ (p =0.048). Specific WU (i.e. Jump) increased SJ (p =0.001), CMJ (p =0.028) and DJ60 (p =0.006) performance. COM increased CMJ performance (p =0.006). Jump was superior in SJ performance vs. PR (p =0.001). Jump reduced (p =0.03) CT in DJ60. In conclusion, general, specific and combined WU increase slow stretch-shortening cycle (SSC) muscle performance, but only specific WU increases fast SSC muscle performance. Therefore, to increase fast SSC performance, specific fast SSC muscle actions must be included during the WU.