Muscle hypertrophy and fast fiber type conversions in heavy resistance-trained women

Twenty-four women completed a 20-week heavy-resistance weight training program for the lower extremity. Workouts were twice a week and consisted of warm-up exercises followed by three sets each of full squats, vertical leg presses, leg extensions, and leg curls. All exercises were performed to failure using 6-8 RM (repetition maximum). Weight training caused a significant increase in maximal isotonic strength (1 RM) for each exercise. After training, there was a decrease in body fat percentage (p less than 0.05), and an increase in lean body mass (p less than 0.05) with no overall change in thigh girth. Biopsies were obtained before and after training from the superficial portion of the vastus lateralis muscle. Sections were prepared for histological and histochemical examination. Six fiber types (I, IC, IIC, IIA, IIAB, and IIB) were distinguished following routine myofibrillar adenosine triphosphatase histochemistry. Areas were determined for fiber types I, IIA, and IIAB + IIB. The heavy-resistance training resulted in significant hypertrophy of all three groups: I (15%), IIA (45%), and IIAB + IIB (57%). These data are similar to those in men and suggest considerable hypertrophy of all major fiber types is also possible in women if exercise intensity and duration are sufficient. In addition, the training resulted in a significant decrease in the percentage of IIB with a concomitant increase in IIA fibers, suggesting that strength training may lead to fiber conversions.     

Feeding tests with caddis larvae (Insecta: Trichoptera) and amphipods (Crustacea: Amphipoda) on Platanus orientalis (Platanaceae) and other leaf litter

In the southern parts of the Mediterranean region, as in the island of Crete, there are few species of riparian trees and shrubs among the dominant Platanus orientalis. Feeding tests have shown that leaves of Platanus are not eaten by aquatic shredders of continental and Cretean origin. The large quantities of organic matter are therefore not used as a source of food and energy by the stream communities. In addition, the high winter flow shortly after leaf fall, and the short courses of rivers result in loss of most of the leaf litter to the sea. The River Continuum Concept does therefore not apply to this region. Field observations have shown that amphipods and limnephilid larvae are shifting from shredding to scraping habits if no leaf litter except Platanus was available.     

An updated check-list of caddisflies (Insecta,Trichoptera) from Iran,with new records

Abstract

A list of the known species of Trichoptera from Iran is given. Since MALICKY (1986), Hydroptila astraia, H.asteria, Chimarra zagrosensis and Hydropsyche iokaste has been newly described from Iran. New records for the country are Ithytrichia clavata, Pseudoneureclipsis graograman, Hydropsyche bitlis, Micropterna hatatitla and Adicella hakkariensis. The species Hydroptila simulans and Hydropsyche pellucidula could not be confirmed for the fauna of Iran.     

Unterschiede im angriffsverhalten vonFormica-arten (Hymenoptera,Formicidae) gegenüber lycaenidenraupen (Lepidoptera)

Zusammenfassung VonFormica (Serviformica) rufibarbis, F. (S.) cunicularia undF. (Raptiformica) sanguinea werden die sonst an Ameisen angepassten Lycaenidenraupen nur in unmittelbarer Nähe des Nesteinganges eines Ameisennestes angegriffen. BeiF. (F.) rufa ist diese Agressivität nicht raum-, sondern vermutlich stimmungsabhängig. Bei verglichenen anderenFormica-Arten trat sie nicht auf.

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Summary Lycaenid caterpillars which usually are adapted to the aggressive behavior of ants are, despite of their adaptations, attacked byFormica (Serviformica) rufibarbis, F. (S.) cunicularia, F. (Raptiformica) sanguinea, andF. (F.) rufa. In the three first-mentionned species this agression happens only in the immediate neighborhood of the entrance to an ant-hill. On the contrary the aggressivity ofF. rufa seems to depend upon the actual mood of the ants but not upon the distance to an entrance. In other species of the genusFormica compared in experiments with Lycaenid larvae no aggressive behavior was observed.

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Résumé Formica (Serviformica) rufibarbis, F. (S.) cunicularia etF. (Raptiformica) sanguinea n'attaquent les chenilles de Lycénides normalement adaptées aux fourmis qu'à proximité immédiate d'une entrée de la fourmilière. ChezFormica (F.) rufa, cette agressivité ne dépend pas du lieu, mais probablement de l'humeur. Chez les autres fourmis étudiées à titre comparatif, on n'a pas constaté d'agressivité envers les chenilles de Lycénides.

     

High mobility group box 1 protein regulates osteoclastogenesis through direct actions on osteocytes and osteoclasts in vitro

Old age and Cx43 deletion in osteocytes are associated with increased osteocyte apoptosis and osteoclastogenesis. We previously demonstrated that apoptotic osteocytes release elevated concentrations of the proinflammatory cytokine, high mobility group box 1 protein (HMGB1) and apoptotic osteocyte conditioned media (CM) promotes osteoclast differentiation. Further, prevention of osteocyte apoptosis blocks osteoclast differentiation and attenuates the extracellular release of HMGB1 and RANKL. Moreover, sequestration of HMGB1, in turn, reduces RANKL production/release by MLO-Y4 osteocytic cells silenced for Cx43 (Cx43^def), highlighting the possibility that HMGB1 promotes apoptotic osteocyte-induced osteoclastogenesis. However, the role of HMGB1 signaling in osteocytes has not been well studied. Further, the mechanisms underlying its release and the receptor(s) responsible for its actions is not clear. We now report that a neutralizing HMGB1 antibody reduces osteoclast formation in RANKL/M-CSF treated bone marrow cells. In bone marrow macrophages (BMMs), toll-like receptor 4 (TLR4) inhibition with LPS-RS, but not receptor for advanced glycation end products (RAGE) inhibition with Azeliragon attenuated osteoclast differentiation. Further, inhibition of RAGE but not of TLR4 in osteoclast precursors reduced osteoclast number, suggesting that HGMB1 produced by osteoclasts directly affects differentiation by activating TLR4 in BMMs and RAGE in preosteoclasts. Our findings also suggest that increased osteoclastogenesis induced by apoptotic osteocytes CM is not mediated through HMGB1/RAGE activation and that direct HMGB1 actions in osteocytes stimulate pro-osteoclastogenic signal release from Cx43^def osteocytes. Based on these findings, we propose that HMGB1 exerts dual effects on osteoclasts, directly by inducing differentiation through TLR4 and RAGE activation and indirectly by increasing pro-osteoclastogenic cytokine secretion from osteocytes.     

Untersuchungen über die Höhlenimmigration von Micropterna nycterobia (Trichoptera,Limnephilidae)

Zusammenfassung Die Imagines von Micropterna spp. übersommern, manchmal in großer Abundanz, in Höhlen. Zur Erklärung der sehr großen quantitativen und qualitativen Unterschiede dieser Besiedlung in verschiedenen Höhlen wurden markierte Exemplare von Micropterna nycterobia in verschiedenen Richtungen und Entfernungen (bis zu 3 km) vom Eingang der Eisensteinhöhle (Niederösterreich) freigelassen. Sie fanden sich im Frühsommer zu nur 1–5% in der Höhle ein, aber ziemlich unabhängig von der Entfernung des Aussetzungsortes und vom individuellen Schlüpftermin. Später im Sommer Freigelassene wanderten nicht mehr in die Höhle ein. Es wird daher vermutet, daß die Migration dieser Tiere nicht gezielt auf Höhlen gerichtet ist und Massenansammlungen in bestimmten Höhlen nur dann zustandekommen, wenn in der Nähe ein besonders reich besiedelter Bach fließt. — Obwohl die Tiere scheinbar in völliger Dunkelheit sitzen, ist nicht auszuschließen, daß ihre Gonadenentwicklung von der Tageslänge abhängt, wie es bei Insekten allgemein üblich ist. Durch Exponieren von lichtempfindlichem Material wurde nachgewiesen, daß sich die Tiere in der Höhle nur dort aufhalten, wohin noch geringe Lichtmengen dringen.

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Summary The adults of Micropterna spp. estivate in caves, but there are considerable differences in abundance and species composition among different caves. Marking-recapture experiments were carried out with M. nycterobia near and in the Eisenstein cave in Lower Austria. Individuals released in early summer in distances up to 3 km from the cave returned and were recaptured there at rates of only 1–5%, but more or less independent of the distance from place of release and of the individual date of emergence. Later in the summer released Micropterna no longer immigrated. It is supposed that the migration of the adults of this species is not exclusively directed to caves, and that high abundance in a given cave depends mainly on mass occurrence of the larval stages in a nearby running stream. By exposure to light-sensitive material it was demonstrated that the caddis flies rest in the cave only in the region of weak illumination. They avoid total darkness. Therefore, we have not excluded that the development of their gonads depends, as is usual in insects, on day length.

     

Fauna of Caddisflies (Trichoptera) of Langkawi Island,Malaysia

Entomological Review - The list of the caddisfly species found in the Langkawi Island has 68 species from 31 genus and 15 families, 24 of which are new to the fauna of Malaysia. A new species from...