bluuebunny/crossref_metadata_2025_split huggingface dataset:
The fossil carnivores of the Transvaal caves. The Hyaenidae of Kromdraai
Authors: Ewer R. F. 
Published: May 2010

Summary.A brief account of the Transvaal fossiliferous deposits is given. It is noted that the Kromdraai “associated” fauna may not be contemporaneous with the Kromdraai australopithecine, Paranthropus robustus.The hyaenids occurring in the Kromdraai deposit are described; additional details of Crocuta spelaea capensis Broom are given, and two new species, Crocuta ultra and Hyaena bellax are described.It is considered that the damaged mandible described by Broom (1939) as possibly belonging to Hyaena hyaena cannot be accepted as a reliable record of the occurrence of this species in the Kromdraai deposit.
Causes of variation in the haemoglobin content of Daphnia (Crustacea: Cladocera) in nature
Authors: Chandler Ann 
Published: May 2010

Summary.

The haemoglobin content of Daphnia in the ponds studied was found to vary inversely with the oxygen concentration in the water, but not to be proportional to the iron content of the water.
In six ponds Daphnia was found to have a greater haemoglobin concentration in winter than in summer, whereas in one body of water the haemoglobin concentration was greater in summer than in winter.
Haemoglobin may be more concentrated in the blood of one pond‐dwelling species of Daphnia than of another species in the same water.
On Mycophilus roseus Hesse, and other notodelphyoid copepods from Strangford Lough, Co. Down
Authors: Gotto R. V. 
Published: May 2010

The taxonomic position of the notodelphyoid copepod Mycophilus roseus Hesse is discussed and an account is given of its occurrence and general biology in Strangford Lough, Co. Down, with notes on the developmental stages. It has been demonstrated that a difference in external form distinguishes adult females inhabiting Botrylloides leachi (Savigny) from those found in Botryllus schlosseri (Pallas). While not discounting the possibility that this divergence is of a specific or subspecific nature, it is suggested that M. roseus exists in two host‐specific “biological forms”.The occurrence is noted in Strangford Lough of nine other notodelphyoid species, five of which are new to the British fauna.
On the development of the frog, Leiopelma hochstetteri Fitzinger
Authors: Stephenson N. G. 
Published: May 2010

Summary.The development of the chondrocranium and visceral arches of Leiopelma hochstetteri Fitzinger is described.The more important, basic developmental features of the genus, which were first noted in L. archeyi Turbott, are confirmed, while specific differences are indicated.Additional evidence for the theory (Stephenson, 1951 a) of the hyoid nature of the basal connexion between the quadrate and the neurocranium in amphibia is presented and discussed.
The head of the frog, Leiopelma hamiltoni McCulloch
Authors: Stephenson Elsie M. 
Published: May 2010

Summary.The cranial anatomy of the rare Stephens Island frog, Leiopelma hamiltoni, is compared with that of the other two species, L. hochstetteri and L. archeyi. For the most part it agrees closely with the detailed description previously given for these latter species. Although L. hamiltoni and L. archeyi exhibit considerable similarity in external appearance and live under more or less comparable habitat conditions, they show certain internal differences in head anatomy. Of eight characters known to be constant specific differences between L. archeyi and L. hochstetteri, L. hamiltoni agrees with L. archeyi in five and with L. hochstetteri in three.
The pattern of bone fusion in the equine metacarpus and metatarsus
Authors: Mills H. D. 
Published: May 2010

Summary.

The order of bony fusion in the metacarpus and metatarsus of the modern Equidae has been investigated in a series of fifty‐one specimens.
Osseous fusion of the metacarpals and metatarsals frequently occurs without the formation of pathological exostoses. This process, although common in domesticated horses, does not invariably occur with advancing age, and it cannot always be distinguished from the final results of “splints”.
Fusion of a metacarpal precedes fusion of the corresponding metatarsal.
Fusion of the second and fourth metacarpals and metatarsals generally follows a preaxial to postaxial sequence.
The fossil carnivores of the Transvaal caves. The Hyaenidae, other than Lycyaena, of Swartkrans and Sterkfontein
Authors: Ewer R. F. 
Published: May 2010

Summary.A number of fossil hyaenids from the Swartkrans deposit are described, comprising:

The skull mentioned by Broom (Broom & Robinson, 1952) and considered by him to belong to a species of Hyaenictis. Reasons are given for concluding that reference to that genus is incorrect and that this specimen must be placed in the genus Leecyaena Young & Liu. It is accordingly named Leecyaena forfex sp. n.
A new species of Crocuta, C. venustula, allied to Crocuta ultra Ewer.
A new subspecies of Hyaena brunnea Thunb., H. brunnea dispar.
A new subspecies of Crocuta crocuta (Erxl.), C. crocuta angella.

Some hyaenid remains from the Sterkfontein Type Site, too incomplete for definite identification, are also described. These include a species of Hyaena, it trifle larger than the living H. brunnea, and a species of Crocuta, possibly identical with C. spelaea (Goldf.). The latter is very lightly fossilized and appears to be of more recent date than the rest of the material from the Sterkfontein Type Site.
The fossil carnivores of the Transvaal caves. The Lycyaenas of Sterkfontein and Swartkrans, together with some general considerations of the Transvaal fossil Hyaenids
Authors: Ewer R. F. 
Published: May 2010

Summary.Two further specimens of Lycyaena silberbergi Broom have been found, one from the Sterkfontein Type Site and the other from Swartkrans. These include regions of the mandible anterior to what was present in Broom's type specimen, and permit the addition of some further details of the structure of this species.A new species, Lycyaena nitidula, is described from Swartkrans. One fragment from the Sterkfontein Type Site probably also belongs to this species.All the species of hyaenid at present known from the three sites, Kromdraai, Swartkrans and the Sterkfontein Type Site are tabulated. Their relationships to other hyaenids are discussed, and their implications as to the relative and absolute dates of the three deposits are considered. It is concluded that of the three deposits the Sterkfontein Type Site is the oldest, separated by only a short time interval from Swartkrans, with Kromdraai later still and separated from Swartkrans by a rather longer time interval. Kromdraai is estimated to be of early Pleistocene age, and Swartkrans and the Sterkfontein Type Site are considered to belong to the top of the upper Pliocene.
The structure and function of the British Pholadidae (Rock‐Boring Lamellibranchia)
Authors: Purchon R. D. 
Published: May 2010

Summary.A detailed investigation has been made into the structure of the principal organ systems and the ciliary mechanisms of the mantle cavity and of the interior of the stomach, in the five British species of Pholadidae (Lamellibranchia).Tabulations have been made of the features characteristic of themajorityof British Pholadidae.In the Pholadidae two anatomical features were noted, which may ultimately be of systematic value: –the presence of an accessory visceral ganglion.the presence of an appendix on the side of the stomach.It was shown that the appendix of the Pholadidae was homologous with the postero‐dorsal caecum of the Tellinacea, and probably also with the wood‐storing caecum of the Teredinidae and ofXylophaga.InXylophaga dorsalis, the absence of a shell apophysis is primitive, and in a number of the Pholadidae a ligament is present. It was concluded that the characteristic (but not diagnostic) features of the Adesmacea may have evolvedprogressivelyin response to the assumption of a rock‐boring habit, and that these characteristics may therefore be lacking in certain congeners which diverged at an early stage from the main stock of the Adesmacea.It is therefore suggested that careful anatomical comparisons should be made between the Pholadidae and other rock‐boring genera such asGastrochaena, to investigate the possibility that such genera might be early offshoots from the parent stock of the Adesmacea.Among the burrowing Lamellibranchia various genera show similarities with the Pholadidae, which could be regarded as pre‐adaptive in nature towards the rock‐boring mode of life.It was found that the cilia in the proximal oral groove of the Pholadidae were typically inactive under experimental conditions. Various reasons for this ciliary inactivity have been offered.It was concluded that the ciliary mechanisms in the stomachs of all five species here considered are primarily concerned with preventing particles from entering the ducts of the digestive diverticula.It was suggested that, most particles having been eliminated from the stomach, the stomach contents are then injected or sucked into the digestive diverticula by volumetric changes brought about primarily by movements of the shell valves and foot, and perhaps by muscles in the stomach wall.The progressive treatment of the stomach contents as outlined above would be assisted by intermittent refusal of food in the proximal oral groove.
Photoperiodism and the testicular refractory period in the mallard
Authors: Lofts B. , Coombs C. J. F. 
Published: May 2010

The effects of winter daylengths on the duration of pituitary refractoriness to photostimulation are described.The mallard, as do probably all wild avian species, enters a postnuptial refractory period during which the gonads display no gametogenesis and the anterior pituitary becomes seasonally unresponsive to photostimulation so far as gonadotrophin secretion is concerned. This phase lasts about three months and is an important synchronizer of the breeding cycles.Refractory specimens kept under a summer daylength of 16.5 hours remain unresponsive to photostimulation at a time when birds in their natural environment are emerging from their refractory period. When, however, such birds are subjected to a period of eight hours daylengths there is a shortening of the refractory phase and they display a gonadotrophic response to photostimulation.There is some indication that a phase of winter daylengths is not, however, a necessary pre‐requisite for birds to be capable of emerging from the refractory period and recovering some degree of spermatogenetic activity. Thus, even in some specimens kept under the long photoperiods there were spermatogonia multiplications occurring when the experiment was terminated.
Abundance, vertical distribution and taxonomy of calanoid copepods at selected stations in the northeast Atlantic
Authors: Grice George D. , Hulsemann Kuni 
Published: May 2010

An analysis is made of the abundance, vertical occurrence and taxonomy of calanoid copepods from 29 samples. The samples were obtained in the northeast Atlantic between approximately 30° and 60°N and at intervals from the surface to a depth of 5000 m.The zooplankton is found to be more abundant in the upper 1000 m of the water column and below 2000 m the concentration is extremely small. The mean size of adult copopods is greater between 500 and 2000 m than in other depth intervals and the greatest number of species occurs in the upper 1000 m. Two new genera, 17 new species and the previously unknown males of three species are described and illustrated. Twenty‐one other species are discussed and five species are reported for the first time from the Atlantic Ocean.
The heart of the Tuatara Sphenodon punctatus
Authors: Simons J. R. 
Published: May 2010

A description of the heart of Sphenodon punctatus (Gray) based on gross dissection, serial sections and wax plate reconstruction of six specimens is given. They were found to resemble most the hearts of lacertilian reptiles. The bulbar region is only partially absorbed into the ventricle. A primary, oblique septum is present, dividing the cavity of the ventricle into a cavum dorsale and a cavum ventrale. Both of these have the same relationship to the various arterial trunks as in other non‐crocodilian reptiles. Of the numerous muscle trabeculae and ridges in the cuvum dorsale none is developed to a greater extent than the others. There is, therefore, no secondary septum in the ventricle. The coronary arteries originate from the left systemic arch to supply the bulbus and ventricle. A gubernaculum cordis is not always present but, if it is, apical coronary vessels pass through it to the ventricle.Consideration of the comparative anatomy of the heart of Sphenodon and those of other existing reptiles leads to the conclusion that it is the most primitive.
Bcl‐2 is a negative regulator of interleukin‐1β secretion in murine macrophages in pharmacological‐induced apoptosis
Authors: Escandell JM , Recio MC , Giner RM , Máñez S , Ríos JL 
Published: May 2010

BACKGROUND AND PURPOSECucurbitacin R, a natural anti‐inflammatory product, has been shown to exhibit activity against both adjuvant‐induced arthritis and delayed‐type hypersensitivity reactions induced by various agents. Previous studies have demonstrated that the effects of cucurbitacin R stem from its inhibition of both cytokine production and lymphocyte proliferation.EXPERIMENTAL APPROACHESEffects of cucurbitacin R were investigated on lipopolysaccharide‐stimulated RAW 264.7 cells. Cell cycle evolution was analysed by flow cytometry, detection of apoptosis by DNA ladder, Bcl‐2, p21, p53, Bax, cleaved caspase‐1 (p10), caspase‐9, and caspase‐3, cleaved caspase (p17) and interleukin‐1β detection was followed by Western blot analysis and mRNA expression with quantitative real time reverse transcription‐polymerase chain reaction (qRT‐PCR).KEY RESULTSCucurbitacin R was found to induce apoptosis in lipopolysaccharide‐stimulated RAW 264.7 macrophages through the inhibition of Bcl‐2 expression, which regulates pro‐inflammatory caspase‐1 activation and interleukin‐1β release. Also, cucurbitacin R arrested the cell cycle in the G2/M phase and increased the subG0 population in lipopolysaccharide‐stimulated RAW 264.7 macrophages. Moreover, it increased the expression of proteins p53 and p21, down‐regulated the expression of Bcl‐2, activated the activity of caspase‐1 and augmented the production of interleukin‐1β. Finally, the transfection of RAW 264.7 macrophages with a Bcl‐2 expression plasmid produced the inhibition of apoptosis and caspase‐1 activation/interleukin‐1β release induced by cucurbitacin R in RAW 264.7 cells.CONCLUSIONS AND IMPLICATIONSTaken together, these results point to a new apoptotic process in which interleukin‐1β release is directly regulated by Bcl‐2 status; this contributes to the evidence that apoptotic processes do not induce inflammation.
Exposing rodents to a combination of tobacco smoke and lipopolysaccharide results in an exaggerated inflammatory response in the lung
Authors: Hardaker EL , Freeman MS , Dale N , Bahra P , Raza F , Banner KH , Poll C 
Published: May 2010

BACKGROUND AND PURPOSEAcute exacerbations of chronic obstructive pulmonary disease (COPD), which are often associated with respiratory infections, are defined as a worsening of symptoms that require a change in medication. Exacerbations are characterized by a reduction in lung function, quality of life and are associated with increased pro‐inflammatory mediators in the lung. Our aim was to develop an animal model to mimic aspects of this exaggerated inflammatory response by combining key etiological factors, tobacco smoke (TS) and bacterial lipopolysaccharide (LPS).EXPERIMENTAL APPROACHRats were exposed to TS for 30 min twice a day for 2 days. On day 3 animals were exposed to LPS for 30 min followed by exposure to TS 5 h later. Inflammation, mucus and lung function were assessed 24 h after LPS.KEY RESULTSNeutrophils, mucus, oedema and cytotoxicity in lung and/or bronchoalveolar lavage was increased in animals exposed to combined LPS and TS, compared with either stimulus alone. Lung function was impaired in animals exposed to combined LPS and TS. Inflammatory cells, oedema and mucus were unaffected by pretreatment with the corticosteroid, budesonide, but were reduced by the phosphodiesterase 4 selective inhibitor roflumilast. Additionally, lung function was improved by roflumilast.CONCLUSIONS AND IMPLICATIONSWe have established an in vivo model mimicking characteristic features of acute exacerbations of COPD including lung function decline and increased lung inflammation. This model may be useful to investigate molecular and cellular mechanisms underlying such exacerbations, to identify new targets and to discover novel therapeutic agents.
Effect of the Itoactivator NS5806 on cloned Kv4 channels depends on the accessory protein KChIP2
Authors: Lundby A , Jespersen T , Schmitt N , Grunnet M , Olesen S‐P , Cordeiro JM , Calloe K 
Published: May 2010

BACKGROUND AND PURPOSEThe compound NS5806 increases the transient outward current (Ito) in canine ventricular cardiomyocytes and slows current decay. In human and canine ventricle, Itois thought to be mediated by KV4.3 and various ancillary proteins, yet, the exact subunit composition of Itochannels is still debated. Here we characterize the effect of NS5806 on heterologously expressed putative Itochannel subunits and other potassium channels.EXPERIMENTAL APPROACHCloned KV4 channels were co‐expressed with KChIP2, DPP6, DPP10, KCNE2, KCNE3 and KV1.4 inXenopus laevisoocytes or CHO‐K1 cells.KEY RESULTSNS5806 increased KV4.3/KChIP2 peak current amplitudes with an EC50of 5.3 ± 1.5µM and significantly slowed current decay. KCNE2, KCNE3, DPP6 and DPP10 modulated KV4.3 currents and the response to NS5806, but current decay was slowed only in complexes containing KChIP2. The effect of NS5806 on KV4.2 was similar to that on KV4.3, and current decay was only slowed in presence of KChIP2. However, for KV4.1, the slowing of current decay by NS5806 was independent of KChIP2. KV1.4 was strongly inhibited by 10 µM NS5806 and KV1.5 was inhibited to a smaller extent. Effects of NS5806 on kinetics of currents generated by KV4.3/KChIP2/DPP6 with KV1.4 in oocytes could reproduce those on cardiac Itoin canine ventricular myocytes. KV7.1, KV11.1 and Kir2 currents were unaffected by NS5806.CONCLUSION AND IMPLICATIONSNS5806 modulated KV4 channel gating depending on the presence of KChIP2, suggesting that NS5806 can potentially be used to address the molecular composition as well as the physiological role of cardiac Ito.
Valerenic acid derivatives as novel subunit‐selective GABAAreceptor ligands –in vitroandin vivocharacterization
Authors: Khom S , Strommer B , Ramharter J , Schwarz T , Schwarzer C , Erker T , Ecker GF , Mulzer J , Hering S 
Published: May 2010

BACKGROUND AND PURPOSESubunit‐specific modulators of γ‐aminobutyric acid (GABA) type A (GABAA) receptors can help to assess the physiological function of receptors with different subunit composition and also provide the basis for the development of new drugs. Valerenic acid (VA) was recently identified as a β2/3subunit‐specific modulator of GABAAreceptors with anxiolytic potential. The aim of the present study was to generate VA derivatives as novel GABAAreceptor modulators and to gain insight into the structure–activity relation of this molecule.EXPERIMENTAL APPROACHThe carboxyl group of VA was substituted by an uncharged amide or amides with different chain length. Modulation of GABAAreceptors composed of different subunit compositions by the VA derivatives was studied inXenopusoocytes by means of the two‐microelectrode voltage‐clamp technique. Half‐maximal stimulation of GABA‐induced chloride currents (IGABA) through GABAAreceptors (EC50) and efficacies (maximal stimulation ofIGABA) were estimated. Anxiolytic activity of the VA derivatives was studied in mice, applying the elevated plus maze test.KEY RESULTSValerenic acid amide (VA‐A) displayed the highest efficacy (more than twofold greaterIGABAenhancement than VA) and highest potency (EC50= 13.7 ± 2.3 µM) on α1β3receptors. Higher efficacy and potency of VA‐A were also observed on α1β2γ2sand α3β3γ2sreceptors. Anxiolytic effects were most pronounced for VA‐A.CONCLUSIONS AND IMPLICATIONSValerenic acid derivatives with higher efficacy and affinity can be generated. Greaterin vitroaction of the amide derivative correlated with a more pronounced anxiolytic effectin vivo. The data give further confidence in targeting β3subunit containing GABAAreceptors for development of anxiolytics.
Enhanced oxidative stress and increased mitochondrial mass during Efavirenz‐induced apoptosis in human hepatic cells
Authors: Apostolova N , Gomez‐Sucerquia LJ , Moran A , Alvarez A , Blas‐Garcia A , Esplugues JV 
Published: May 2010

BACKGROUND AND PURPOSEEfavirenz (EFV) is widely used in the treatment of HIV‐1 infection. Though highly efficient, there is growing concern about EFV‐related side effects, the molecular basis of which remains elusive.EXPERIMENTAL APPROACHIn vitro studies were performed to address the effect of clinically relevant concentrations of EFV (10, 25 and 50 µM) on human hepatic cells.KEY RESULTSCellular proliferation and viability were reduced in a concentration‐dependent manner. Analyses of the cell cycle and several cell death parameters (chromatin condensation, phosphatidylserine exteriorization, mitochondrial proapoptotic protein translocation and caspase activation) revealed that EFV triggered apoptosis via the intrinsic pathway. In addition, EFV directly affected mitochondrial function in a reversible manner, inducing a decrease in mitochondrial membrane potential and an increase in mitochondrial superoxide production, followed by a reduction in cellular glutathione content. The rapidity of these actions rules out any involvement of mitochondrial DNA replication, which, until now, was thought to be the main mechanism of mitochondrial toxicity of antiretroviral drugs. Importantly, we also observed an increase in mitochondrial mass, manifested as an elevated cardiolipin content and enhanced expression of mitochondrial proteins, which was not paralleled by an increase in the mtDNA/nuclear DNA copy number ratio. The toxic effect of EFV was partially reversed by antioxidant pretreatment, which suggests ROS generation is involved in this effect.CONCLUSION AND IMPLICATIONSClinically relevant concentrations of EFV were shown to be mitotoxic in human hepatic cells in vitro, which may be pertinent to the understanding of the hepatotoxicity associated with this drug.