Two new species of <Emphasis Type="Italic">Parspina</Emphasis> Pearse, 1920 (Digenea: Cryptogonimidae) from freshwater fishes (Gymnotiformes) of the Paraná River basin in Argentina

Two new species of the cryptogonimid genus Parspina Pearse, 1920 are described from gymnotiform fishes of the Paraná River basin, P. carapo n. sp. from the banded knifefish Gymnotus carapo Linnaeus and P. virescens n. sp. from the glass knifefish Eigenmannia virescens (Valenciennes). Parspina carapo differs from P. virescens in the number of oral spines (32–39 vs 30–33) and their length (28–47 vs 16–28 μm), the distribution of tegumental spines and their anchorage, the types of sensory papillae on the body surface (three vs two types), the extent of body length posterior to the caeca (5 vs 13% of the total body length), the dimensions of the pars prostatica (52 × 34 vs 24 × 10 μm), and in the absence of a gonotyl (vs presence). Both P. carapo and P. virescens differ from P. bagre Pearse, 1920 and P. argentinensis (Szidat, 1954) in the number of oral spines (20–21 and 21–28 in the latter pair) and their length (28–32 and 35–60 μm), and in total body length. Additionally, the two new species differ from P. argentinensis in the arrangement of the vitelline follicles (one continuous band vs two groups on each side of the body) and in having a smaller pars prostatica (149 × 49 μm in the latter). Parspina carapo is the fifth intestinal helminth found in G. carapo, and P. virescens is the first found in E. virescens.     

Bacterial Ghosts as antigen and drug delivery system for ocular surface diseases: Effective internalization of Bacterial Ghosts by human conjunctival epithelial cells

The purpose of the presented investigation was to examine the efficiency of the novel carrier system Bacterial Ghosts (BGs), which are empty bacterial cell envelopes of Gram-negative bacteria to target human conjunctival epithelial cells, as well as to test the endocytic capacity of conjunctival cells after co-incubation with BGs generated from different bacterial species, and to foreclose potential cytotoxic effects caused by BGs. The efficiency of conjunctival cells to internalize BGs was investigated using the Chang conjunctival epithelial cell line and primary human conjunctiva-derived epithelial cells (HCDECs) as in vitro model. A high capacity of HCDECs to functionally internalize BGs was detected with the level of internalization depending on the type of species used for BGs generation. Detailed analysis showed no cytotoxic effect of BGs on HCDECs independently of the used bacterial species. Moreover, co-incubation with BGs did not enhance expression of both MHC class I and class II molecules by HCDECs, but increased expression of ICAM-1. The high rates of BG's internalization by HCDECs with no BG-mediated cytotoxic impact designate this carrier system to be a promising candidate for an ocular surface drug delivery system. BGs could be useful for future therapeutic ocular surface applications and eye-specific disease vaccine development including DNA transfer.     

Testicular Histomorphometry and Ultrastructure of Rats Treated with Cadmium and Ginkgo biloba

The aim of this study is to investigate the association of a single low dose of Cd and daily doses of Ginkgo biloba extract (GbE) on the testis and accessory glands of rats. The animals were treated with a single dose of 3 µmol/kg body weight of cadmium chloride (CdCl₂) and/or 100 mg/kg body weight of GbE. The plasma testosterone levels; corporal, testicular, and accessory glands weight; gonadosomatic index, volumetric proportion; and absolute volume of testicular components did not change after the treatments. CdCl₂ caused significant reduction in Leydig cells volume and altered Leydig cell morphology, as well as vacuolated Sertoli cells cytoplasm, irregular chromatin condensation of late spermatids, and modified acrosome formation. However, animals that received GbE did not show these alterations. The reversal of Cd-induced alterations by the extract is a strong indication that G. biloba is helpful in diminishing the effect of Cd toxicity.     

La unidad de ortogeriatría de agudos. Evaluación de su efecto en el curso clínico de los pacientes con fractura de cadera y estimación de su impacto económico

Objective

To study the effects of the management of hip fracture patients in an acute orthogeriatric unit shared between the departments of Orthopedic Surgery and Geriatrics compared with the usual hospital care, and to analyse financial differences in both systems of care.

Method

Prospective quasy-experimental randomized intervention study in 506 patients admited to a terciary hospital with an osteoporotic hip fracture. The usual model of care was the admission to the orthopedic ward with a request to Geriatrics (RC) and the study model consisted of the admission to an orthogeriatric unit (OGU) for the shared co-management between orthopaedic surgeons and geriatricians. This model included the appointment of one spokesperson from each department, the specialist geriatric nurse management, early geriatric assessment, shared daily clinical care, weekly joint ward round and coordinated planning of the surgery schedule, the start of the ambulation and the time and setting of patient discharge.

Results

Two hundred fifty five consecutive patients admitted to the OGU and 251 patients managed simultaneusly by the RC model were included. Except for a mean age slightly lower in the OGU group, there were no differences neither in the baseline patients characteristics nor in the surgical rates between the two groups. Among the OGU patients group it was more frequent to receive rehabilitation in the acute setting, to be able to walk at discharge and to be referred to a geriatric rehabilitation unit (all with P<.05). The OGU patients received geriatric assessment and were operated on earlier than the RC patients (P<.001). The length of stay in the acute ward was 34% shorter in the OGU patients (mean 12.48±5 vs 18.9±8.6 days, P<.001) (median 12 [9-14] vs 17 [13-23] days, P<.001). The whole hospital length of stay, including the days spent in the geriatric rehabilitation units, was 11% shorter in the OGU patients (mean 21.16 ±14.7 vs 23.9 ±13.8 days, P<0.05) (median 14 [10-31] vs 20 [14-30] days, P<.001). The OGU saved 1,207 € to 1,633 € per patient when estimated by the costs for process model, and 3,741 € when estimated by the costs for stay model.

Conclusions

The OGU is a hospital setting that provides an improvement in the patients functional outcome and a reduction in the hospital length of stay. Therefore it saves health care resources. These findings show the OGU as an advisable setting for the acute care of hip fracture patients.     

Light acclimation at the end of the growing season in two broadleaved oak species

The ability of plants to increase their net CO₂ assimilation rate in response to increased irradiance is due to morphological and physiological changes, which might be related to their shade tolerance and leaf ontogeny, but few studies have considered morphology and physiology. Two sympatric oak species (the shade-tolerant Q. petraea and the comparatively shade-intolerant Q. pyrenaica) were grown in hydroponic solution in low-light (LL) and high-light (HL) conditions. 5 months after leaf expansion under these conditions, half of the LL plants were transferred to high light (TLH). Transfer of Q. pyrenaica, from low- to high light led to photoinhibition and after 21 days in higher light there was little acclimation of the maximum rate of carboxylation (V_Cmax) or the maximum rate of electron transport (J_max). Q. pyrenaica TLH plants showed lower stomatal conductance at all times compared to plants growing in LL. Stomatal closure was the main limitation to photosynthesis after transfer in Q. pyrenaica. The increase in evaporative demand upon TLH did not affect hydraulic conductivity of Q. pyrenaica. In contrast, the more shade-tolerant Q. petraea showed a greater degree of acclimation of gas exchange in TLH than Q. pyrenaica and two weeks after transfer gas-exchange rates were as high as in LL plants. In Q. petraea, the most important changes occurred at the level of leaf biochemistry with significant increase in V_Cmax that decreased the J_max/V_Cmax ratio below values recorded in HL plants. However, this potential increase in photosynthesis was at least partially hamstrung by a decrease in internal conductance, which highlights the importance of internal conductance in acclimation to higher light in mature leaves. Neither oak species reached the photosynthetic rates of HL plants; however a trend towards leaf acclimation was observed in Q. petraea while the transfer was harmful to the leaves of Q. pyrenaica developed in the shade.     

Daxx mediates activation-induced cell death in microglia by triggering MST1 signalling

Microglia, the resident macrophages of the mammalian central nervous system, migrate to sites of tissue damage or infection and become activated. Although the persistent secretion of inflammatory mediators by the activated cells contributes to the pathogenesis of various neurological disorders, most activated microglia eventually undergo apoptosis through the process of activation-induced cell death (AICD). The molecular mechanism of AICD, however, has remained unclear. Here, we show that Daxx and mammalian Ste20-like kinase-1 (MST1) mediate apoptosis elicited by interferon-γ (IFN-γ) in microglia. IFN-γ upregulated the expression of Daxx, which in turn mediated the homodimerization, activation, and nuclear translocation of MST1 and apoptosis in microglial cells. Depletion of Daxx or MST1 by RNA interference also attenuated IFN-γ-induced cell death in primary rat microglia. Furthermore, the extent of IFN-γ-induced death of microglia in the brain of MST1-null mice was significantly reduced compared with that apparent in wild-type mice. Our results thus highlight new functions of Daxx and MST1 that they are the key mediators of microglial cell death initiated by the proinflammatory cytokine IFN-γ.     

Light and scanning electron microscopic study of the tongue in the estuarine dolphin (Sotalia guianensis van Bénéden, 1864)

The importance of the tongue during feeding, and the limited information on the tongue of most aquatic mammals led us to investigate its morphological aspects in sexually immature and mature Sotalia guianensis. Six tongues were measured and photo-documented after their removal from the oral cavity. The samples were divided into rostral, middle, and caudal regions, and examined using light microscopy and scanning electron microscopy (S.E.M.). Sotalia guianensis tongue presented lateral grooves from the apex to the middle portion, while the anterolateral region presented marginal papillae. Histological characteristics revealed the presence of a keratinized stratified epithelium, salivary glands in the middle and caudal portions of the tongue, and filiform papillae in the caudal region. S.E.M. images revealed the presence of filiform papillae and ducts of salivary glands in the middle and caudal portions of the tongue. We can conclude that the characteristics found in this study may reflect an adaptation to changes in diet after weaning.     

The Aspergillus fumigatus sialidase is a 3-deoxy-D-glycero-D-galacto-2-nonulosonic acid hydrolase (KDNase): structural and mechanistic insights

Aspergillus fumigatus is a filamentous fungus that can cause severe respiratory disease in immunocompromised individuals. A putative sialidase from A. fumigatus was recently cloned and shown to be relatively poor in cleaving N-acetylneuraminic acid (Neu5Ac) in comparison with bacterial sialidases. Here we present the first crystal structure of a fungal sialidase. When the apo structure was compared with bacterial sialidase structures, the active site of the Aspergillus enzyme suggested that Neu5Ac would be a poor substrate because of a smaller pocket that normally accommodates the acetamido group of Neu5Ac in sialidases. A sialic acid with a hydroxyl in place of an acetamido group is 2-keto-3-deoxynononic acid (KDN). We show that KDN is the preferred substrate for the A. fumigatus sialidase and that A. fumigatus can utilize KDN as a sole carbon source. A 1.45-Å resolution crystal structure of the enzyme in complex with KDN reveals KDN in the active site in a boat conformation and nearby a second binding site occupied by KDN in a chair conformation, suggesting that polyKDN may be a natural substrate. The enzyme is not inhibited by the sialidase transition state analog 2-deoxy-2,3-dehydro-N-acetylneuraminic acid (Neu5Ac2en) but is inhibited by the related 2,3-didehydro-2,3-dideoxy-d-glycero-d-galacto-nonulosonic acid that we show bound to the enzyme in a 1.84-Å resolution crystal structure. Using a fluorinated KDN substrate, we present a 1.5-Å resolution structure of a covalently bound catalytic intermediate. The A. fumigatus sialidase is therefore a KDNase with a similar catalytic mechanism to Neu5Ac exosialidases, and this study represents the first structure of a KDNase.     

Activation of NLRC4 by flagellated bacteria triggers caspase-1-dependent and -independent responses to restrict Legionella pneumophila replication in macrophages and in vivo

Although NLRC4/IPAF activation by flagellin has been extensively investigated, the downstream signaling pathways and the mechanisms responsible for infection clearance remain unclear. In this study, we used mice deficient for the inflammasome components in addition to wild-type (WT) Legionella pneumophila or bacteria deficient for flagellin (flaA) or motility (fliI) to assess the pathways responsible for NLRC4-dependent growth restriction in vivo and ex vivo. By comparing infections with WT L. pneumophila, fliI, and flaA, we found that flagellin and motility are important for the colonization of the protozoan host Acanthamoeba castellanii. However, in macrophages and mammalian lungs, flagellin expression abrogated bacterial replication. The flagellin-mediated growth restriction was dependent on NLRC4, and although it was recently demonstrated that NLRC4 is able to recognize bacteria independent of flagellin, we found that the NLRC4-dependent restriction of L. pneumophila multiplication was fully dependent on flagellin. By examining infected caspase-1(-/-) mice and macrophages with flaA, fliI, and WT L. pneumophila, we could detect greater replication of flaA, which suggests that caspase-1 only partially accounted for flagellin-dependent growth restriction. Conversely, WT L. pneumophila multiplied better in macrophages and mice deficient for NLRC4 compared with that in macrophages and mice deficient for caspase-1, supporting the existence of a novel caspase-1-independent response downstream of NLRC4. This response operated early after macrophage infection and accounted for the restriction of bacterial replication within bacteria-containing vacuoles. Collectively, our data indicate that flagellin is required for NLRC4-dependent responses to L. pneumophila and that NLRC4 triggers caspase-1-dependent and -independent responses for bacterial growth restriction in macrophages and in vivo.     

Identification of phenolic compounds in isolated vacuoles of the medicinal plant Catharanthus roseus and their interaction with vacuolar class III peroxidase: an H₂O₂ affair?

Class III peroxidases (Prxs) are plant enzymes capable of using H(2)O(2) to oxidize a range of plant secondary metabolites, notably phenolic compounds. These enzymes are localized in the cell wall or in the vacuole, which is a target for secondary metabolite accumulation, but very little is known about the function of vacuolar Prxs. Here, the physiological role of the main leaf vacuolar Prx of the medicinal plant Catharanthus roseus, CrPrx1, was further investigated namely by studying its capacity to oxidize co-localized phenolic substrates at the expense of H(2)O(2). LC-PAD-MS analysis of the phenols from isolated leaf vacuoles detected the presence of three caffeoylquinic acids and four flavonoids in this organelle. These phenols or similar compounds were shown to be good CrPrx1 substrates, and the CrPrx1-mediated oxidation of 5-O-caffeoylquinic acid was shown to form a co-operative regenerating cycle with ascorbic acid. Interestingly, more than 90% of total leaf Prx activity was localized in the vacuoles, associated to discrete spots of the tonoplast. Prx activity inside the vacuoles was estimated to be 1809 nkat ml(-1), which, together with the determined concentrations for the putative vacuolar phenolic substrates, indicate a very high H(2)O(2) scavenging capacity, up to 9 mM s(-1). Accordingly, high light conditions, known to increase H(2)O(2) production, induced both phenols and Prx levels. Therefore, it is proposed that the vacuolar couple Prx/secondary metabolites represent an important sink/buffer of H(2)O(2) in green plant cells.