Differences in the oxygenation of the forearm muscle during isometric contraction in trained and untrained subjects

The aim of this study was to test a hypothesis that a longer duration of isometric contraction is related to an increased oxygenation status of the muscle. A group of trained rock climbers and untrained subjects performed 15 kp sustained isometric contraction until fatigue set in. The oxygenation status was assessed using near infrared spectroscopy (ISS, USA). The results support the hypothesis. The concentration of relative oxygenated hemoglobin was higher in the rock climbers than in the untrained subjects. The relative total hemoglobin did not differentiate the two groups enough to show that blood volume also strongly influences contraction time.     

The Patentability of Biomolecules – Does Online Bioinformatics Compromise Novelty?

Researchers are becoming increasingly concerned that the confidentiality of their novel biomolecule sequences is being jeopardised, particularly when these sequences are either submitted to sequence databases or uploaded as query terms onto internet-based bioinformatic software suites. The researcher's fears stem from the fact that the actual uploading of their sequences acts as a novelty destroying prior disclosure or publication, and that this may subsequently preclude valid patent protection for the sequences. This article addresses the key issues involved in the analyses of biomolecules, highlighting potential risks taken by many researchers in regard to patent protection and suggests possible ways in which these risks may be mitigated.     

Neuronal differentiation is accompanied by NSP-C expression

Neuroendocrine-specific protein (NSP) reticulons are expressed in neural and neuroendocrine tissues and cell cultures derived therefrom, while most other cell types lack NSP-reticulons. Three major subtypes have been identified so far, designated NSP-A, NSP-B, and NSP-C. We have investigated the correlation between the degree of neuronal differentiation, determined by morphological and biochemical criteria, and NSP-reticulon subtype expression. For this purpose, several human neuroblastoma cell lines, exhibiting different degrees of neuronal differentiation, were examined immuno(cyto) chemically. It became obvious that the expression of NSP-C, as detected by immunofluorescence microscopy and Western blotting, is most prominent in cell lines with a high degree of neuronal differentiation, such as LA-N-5. Such highly differentiated cells also express other neural and neuroendocrine markers, such as neural cell adhesion molecule (NCAM), neurofilament proteins, synaptophysin, and chromogranin. NSP-A was observed in all cell lines to a different extent. However, no clear correlation was observed with the degree of neuronal differentiation as defined by other neuronal and neuroendocrine markers or morphology. NSP-B could not be detected. The induction of neuronal differentiation with nerve growth factor, dbcAMP, and retinoic acid in the rat pheochromocytoma cell line PC12 and the human teratocarcinoma cell line hNT2, respectively, induced the expression of NSP-A and NSP-C in these cell lines parallel to the induction of neurofilament protein expression. It is concluded that NSP-C expression, in particular, is strongly correlated with neuronal differentiation.     

On the evolution of adult head structures and the phylogeny of Hydraenidae (Coleoptera, Staphyliniformia)

External and internal head structures of adults of Orchymontiinae, Prosthetopinae, Hydraeninae and Ochthebiinae were studied and those of Ochthebius semisericeus and Limnebius truncatellus are described in detail. The results are evaluated with respect to their relevance for a reconstruction of hydraenid phylogeny and also compared with structural features found in adults of other staphyliniform families. The monophyly of Hydraenidae is supported by the presence of a plate‐like, trilobed premento‐hypopharyngeal extension, an unusual origin of m. tentoriohypopharyngalis, dorsal tentorial arms firmly fused with the head capsule, modified basal antennomeres, and palpigers connected by a transverse sclerotized bar. Orchymontiinae are monophyletic and the basal sister group of the remaining Hydraenidae. The presence of a ventral transverse genal bulge and of a pubescent antennal club with more than two antennomeres (reversal in some prosthetopines: e.g. Mesoceration abstrictum) are possible apomorphies of Hydraenidae excluding Orchymontiinae. Prosthetopinae are probably monophyletic and the sister group of Ochthebiinae + Hydraeninae. The latter clade is characterized by a distinct cupula formed by antennomere VI, a loose five‐segmented pubescent antennal club, and a modified antennal musculature. The presence of an unusual tentorio‐pharyngeal dilator is a shared derived feature of Ochthebiinae and the genus Davidraena. The monophyly of Ochthebiinae was confirmed and Ochtheosus is the sister group of the remaining ochthebiine genera, which are characterized by a perforated wall‐like structure formed by the posterior tentorial arms. The absence of this tentorial modification and the fimbriate galea are plesiomorphies retained in Ochtheosus. Calobius differs strongly from other subgenera of Ochthebius and a generic status may be appropriate. The monophyly of Hydraeninae is not supported. Hydraena was confirmed as a clade and Laeliaena and Limnebius are sister groups. The latter genus is characterized by several autapomorphies. The basal position of Orchymontiinae and Prosthetopinae suggests a Gondwanan origin of Hydraenidae and a primary preference for life in running water. Important evolutionary changes of head structures are complex transformations of the antennae and related structures. Yet, the use of the antennae as accessory breathing organs is not a groundplan feature of the family. The results of this study strengthen the case of staphylinoid affinities of Hydraenidae.     

Estimation of the proportion of metabolically active mass in the amphipod Gammarus fossarum

1. The proportion of metabolically active mass in the freshwater amphipod Gammarus fossarum was determined using different parameters [chemical oxygen demand (COD), total nitrogen (N_tot), total phosphorus (P_tot) and mass of chitinous cuticle]. 2. The results of linear regressions between body mass and body length, and measured parameters (COD, N_tot, P_tot) show high correlation coefficients for both fresh and the dry animals. The proportion of chitinous mass increased with body size. 3. Chemical analysis of P_tot in individuals appears to be the most appropriate parameter for quantitating the metabolically active tissues in animals. 4. The dependence of the intensity of electron transport system (ETS) activity per protoplasm, calculated from the P_tot and dry mass of animals, shows that large animals have the same ETS activity per unit of protoplasm as smaller ones. 5. We conclude that the chitinous mass is not the only factor which contributes to negative allometry of metabolic activity in G. fossarum.     

The External Structure and Distribution of Sensilla in the Medicinal Leech

Abstract The body of Hirudo medicinalis consists of 32 segments. The quinquannulate midbody segments 3–18 bear 14 sensilla on the central (neural) annulus. Elsewhere segments are represented by fewer than five annuli but sensilla are retained on the neural annulus. From neural sensilla protrude S hairs (cilia from uniciliate cells) which are thought to detect water currents. Two categories of multiciliate cell, of unknown function, are also present within neural sensilla; (i) grouped cilia extending beyond the cuticle (G hairs), and (ii) cilia which radiate out beneath the cuticle. Studies of the entire external surface of leech body wall with a scanning electron microscope revealed the presence of large numbers of sensilla on every annulus including the neural annuli. These sensilla lack S hairs. Our results show: (i) annular sensilla have a significantly smaller surface area than neural sensilla (p < 0.001 Mann-Whitney test, 2 tailed), (ii) The position and number of the small sensilla varies from annulus to annulus, segment to segment and individual to individual, (iii) Significantly higher numbers of small sensilla were found where non-neural annuli remain single and have not undergone a further division during development as happens in the quinquannulate segments. The data suggest that small sensilla continue to be added during the adult life of the leech.