Sperm storage by females across the animal phyla: A survey on the occurrence and biomolecules involved in sperm storage.

Long-term sperm storage by females in various regions of the oviduct is documented across many invertebrate and vertebrate species. Although, many reports emphasize on the histology, histochemistry and ultrastructural features of sperm storage, very little is known about the mechanisms underlying the sperm storage. The current review documents the occurrence of sperm storage by females in a wide array of invertebrate and vertebrate species. This review also provides an insight on the presence of various molecular factors of the sperm storage tubules presumably responsible for the prolonged sperm storage with an emphasis on a model reptile, the Indian garden lizard, Calotes versicolor which contains a unique approximately 55-kDa protein in its utero-vaginal lavage and found to inhibit washed epididymal sperm motility in a concentration and time-dependent manner in a reversible fashion.

Constraining the Neutron Star Compactness: Extraction of the

The ^{23}Al(p,γ)^{24}Si reaction is among the most important reactions driving the energy generation in type-I x-ray bursts. However, the present reaction-rate uncertainty limits constraints on neutron star properties that can be achieved with burst model-observation comparisons. Here, we present a novel technique for constraining this important reaction by combining the GRETINA array with the neutron detector LENDA coupled to the S800 spectrograph at the National Superconducting Cyclotron Laboratory. The ^{23}Al(d,n) reaction was used to populate the astrophysically important states in ^{24}Si. This enables a measurement in complete kinematics for extracting all relevant inputs necessary to calculate the reaction rate. For the first time, a predicted close-lying doublet of a 2_{2}^{+} and (4_{1}^{+},0_{2}^{+}) state in ^{24}Si was disentangled, finally resolving conflicting results from two previous measurements. Moreover, it was possible to extract spectroscopic factors using GRETINA and LENDA simultaneously. This new technique may be used to constrain other important reaction rates for various astrophysical scenarios.

HD-Zip Proteins GL2 and HDG11 Have Redundant Functions in Arabidopsis Trichomes, and GL2 Activates a Positive Feedback Loop via MYB23.

The class IV homeodomain leucine zipper transcription factor GLABRA2 (GL2) acts in a complex regulatory circuit that regulates the differentiation of trichomes in Arabidopsis thaliana. We describe a genetic interaction with HOMEODOMAIN GLABROUS11 (HDG11), previously identified as a negative regulator of trichome branching. gl2 hdg11 double mutants display enhanced trichome cell-type differentiation defects. Transgenic expression of HDG11 using the GL2 promoter partially suppresses gl2 trichome phenotypes. Vice versa, expression of GL2 under the control of its native promoter partially complements hdg11 ectopic branching. Since gl2 hdg11 and gl2 myb23 double mutants and the triple mutant display similar trichome differentiation defects, we investigated a connection to the R2R3-MYB transcription factor MYB23. We show that MYB23 transcript levels are significantly reduced in shoots from gl2 mutants and that GL2 can drive the expression of a MYB23-promoter fusion to green fluorescent protein. Yeast one-hybrid, chromatin immunoprecipitation, and in planta reporter gene experiments indicate that an L1-box in the MYB23 promoter acts as a GL2 binding site. Taken together, our findings reveal a functional redundancy between GL2 and HDG11, two homeodomain leucine zipper transcription factors previously thought to mediate opposing functions in trichome morphogenesis. A model is proposed in which GL2 transcript levels are maintained through a positive feedback loop involving GL2 activation of MYB23.

Effect of Amphotericin B Nanodisks on Leishmania major Infected Mice.

OBJECTIVE: To assess the efficacy of a novel formulation of the polyene antibiotic, amphotericin B (AMB), as therapy for cutaneous leishmaniasis in different mouse strains. METHODS: (AMB), was formulated into water-soluble transport particles, termed nanodisks (ND). Balb/c and CH3 mice infected with Leishmania major on Day 0 were administered vehicle alone, empty ND or AMB-ND on Day 1 and day 7, via the tail vein. Mice were sacrificed 25 or 50 days post inoculation and tissue histology evaluated. Balb/c mice treated with vehicle or empty ND showed signs of severe infection while CH3 mice had less inflammation and fewer parasites. AMB-ND treatment (2 mg/kg) had a marked therapeutic effect on L. major infected Balb/c mice and a discernable therapeutic benefit on CH3 mice. CONCLUSIONS: AMB-ND is efficacious in the treatment of cutaneous leishmaniasis in both susceptible and resistant mouse strains. It may be inferred that AMB-ND may be useful for prophylactic and/or treatment of early stage Leishmania spp. infection.

Interferon release does not add discriminatory value to smear-negative HIV-tuberculosis algorithms.

Clinical algorithms for evaluating HIV-infected individuals for tuberculosis (TB) prior to isoniazid preventive therapy (IPT) perform poorly, and interferon-γ release assays (IGRAs) have moderate accuracy for active TB. It is unclear whether, when used as adjunct tests, IGRAs add any clinical discriminatory value for active TB diagnosis in the pre-IPT assessment. 779 sputum smear-negative HIV-infected persons, established on or about to commence combined antiretroviral therapy (ART), were screened for TB prior to IPT. Stepwise multivariable logistic regression was used to develop clinical prediction models. The discriminatory ability was assessed by receiver operator characteristic area under the curve (AUC). QuantiFERON-TB Gold in-tube (QFT-GIT) was evaluated. The prevalence of smear-negative TB by culture was 6.4% (95% CI 4.9-8.4%). Used alone, QFT-GIT and the tuberculin skin test (TST) had comparable performance; the post-test probability of disease based on single negative tests was 3-4%. In a multivariable model, the QFT-GIT test did not improve the ability of a clinical algorithm, which included not taking ART, weight <60 kg, no prior history of TB, any one positive TB symptom/sign (cough ≥ 2 weeks) and CD4+ count <250 cells per mm(3), to discriminate smear-negative culture-positive and -negative TB (72% to 74%; AUC comparison p=0.33). The TST marginally improved the discriminatory ability of the clinical model (to 77%, AUC comparison p=0.04). QFT-GIT does not improve the discriminatory ability of current TB screening clinical algorithms used to evaluate HIV-infected individuals for TB ahead of preventive therapy. Evaluation of new TB diagnostics for clinical relevance should follow a multivariable process that goes beyond test accuracy.

Multi-camera real-time three-dimensional tracking of multiple flying animals.

Automated tracking of animal movement allows analyses that would not otherwise be possible by providing great quantities of data. The additional capability of tracking in real time--with minimal latency--opens up the experimental possibility of manipulating sensory feedback, thus allowing detailed explorations of the neural basis for control of behaviour. Here, we describe a system capable of tracking the three-dimensional position and body orientation of animals such as flies and birds. The system operates with less than 40 ms latency and can track multiple animals simultaneously. To achieve these results, a multi-target tracking algorithm was developed based on the extended Kalman filter and the nearest neighbour standard filter data association algorithm. In one implementation, an 11-camera system is capable of tracking three flies simultaneously at 60 frames per second using a gigabit network of nine standard Intel Pentium 4 and Core 2 Duo computers. This manuscript presents the rationale and details of the algorithms employed and shows three implementations of the system. An experiment was performed using the tracking system to measure the effect of visual contrast on the flight speed of Drosophila melanogaster. At low contrasts, speed is more variable and faster on average than at high contrasts. Thus, the system is already a useful tool to study the neurobiology and behaviour of freely flying animals. If combined with other techniques, such as 'virtual reality'-type computer graphics or genetic manipulation, the tracking system would offer a powerful new way to investigate the biology of flying animals.

The immunomodulatory factors of arthropod saliva and the potential for these factors to serve as vaccine targets to prevent pathogen transmission.

In general, attempts to develop vaccines for pathogens transmitted by arthropods have met with little or no success. It has been widely observed that the saliva of arthropods that transmit disease enhances the infectivity of pathogens the arthropod transmits to the vertebrate host. Indeed, it has been observed that vaccinating against components of the saliva of arthropods or against antigens expressed in the gut of arthropods can protect the host from infection and decrease the viability of the arthropod. These results suggest that multi-subunit vaccines that target the pathogen itself as well as arthropod salivary gland components and arthropod gut antigens may be the most effective at controlling arthropod-borne pathogens as these vaccines would target several facets of the lifecycle of the pathogen. This review covers known immunomodulators in arthropod salivary glands, instances when arthropod saliva has been shown to enhance infection and a limited number of examples of antiarthropod vaccines, with emphasis on three arthropods: sandflies, mosquitoes and hard ticks.

Infection with Leishmania major stimulates haematopoiesis in susceptible BALB/c mice and suppresses haematopoiesis in resistant CBA mice.

Cytokine responses to Leishmania infection begin very early in infection, and differ between susceptible and resistant mice. Susceptibility to chronic Leishmania infection has been associated with increased haematopoiesis. To analyse the effect that acute infection with L. major has on bone-marrow haematopoiesis in susceptible (BALB/c) and resistant (CBA) mice, we enumerated erythroid progenitors and granulocyte-monocyte progenitors 3 days after infection. We found that haematopoiesis was stimulated in BALB/c mice infected with L. major, while haematopoiesis was inhibited in CBA mice. We found that this effect could be partially explained by cytokine production: interleukin-4 was involved in stimulation of BALB/c haematopoiesis and tumour necrosis factor-alpha was involved in inhibition of CBA haematopoiesis. Our conclusions are that haematopoietic changes occur shortly after L. major infection, and may be related to disease outcome.

Palmar dislocation of the trapezoid.

Palmar dislocation of the trapezoid is a rare injury, which results from substantial trauma to the wrist. It is associated with other bony or ligamentous injuries in the wrist. If unrecognized, loss of function of the hand and early osteoarthritis may result. Treatment of choice is open reduction and internal fixation, which generally achieves good functional results. We describe a new case of palmar dislocation of the trapezoid and review the world literature with emphasis on the radiographic findings.

Radiation injury of the lung after three-dimensional conformal radiation therapy.

OBJECTIVE: The objective of this study is to describe the CT patterns of radiation injury in the lungs of patients who have undergone three-dimensional (3D) conformal radiation therapy (CRT). MATERIALS AND METHODS: Over a 36-month period, the chest CT scans of 19 patients with non-small cell lung cancer who were treated with 3D CRT were reviewed. CT scans were evaluated for findings of radiation injury (ground-glass opacities, consolidation, bronchiectasis, and volume loss). The presence, extent, and distribution of these findings were reached by consensus. RESULTS: Radiation pneumonitis limited to a small area immediately around the tumor was present in all patients who were imaged within 3 months after completion of the treatment (n = 7). Radiation-induced fibrosis occurred in all patients (n = 19). Three distinct patterns of fibrosis were consistently present, and these were classified as modified conventional, masslike, and scarlike. Modified conventional fibrosis (consolidation, volume loss, and bronchiectasis similar to, but less extensive than, conventional radiation fibrosis) was seen in five patients. Masslike fibrosis (focal consolidation with traction bronchiectasis limited to the site of the original tumor) was seen in eight patients. Scarlike fibrosis (linear opacity in the region of the original tumor associated with moderate to severe volume loss) was seen in six patients. CONCLUSION: Three-dimensional conformal radiation therapy results in three patterns of radiation fibrosis that differ from the conventional radiation-induced lung injury. Knowledge of the full spectrum of these manifestations is useful in the correct interpretation of CT scans after 3D CRT.

Radiation injuries after fluoroscopic procedures.

Fluoroscopically guided diagnostic and interventional procedures have become much more commonplace over the last decade. Current fluoroscopes are easily capable of producing dose rates in the range of 0.2 Gy (20 rads) per minute. The dose rate often changes dramatically with patient positioning and size. Most machines currently in use have no method to display approximate patient dose other than the rough surrogate of total fluoroscopy time. This does not include patient dose incurred during fluorography (serial imaging or cine runs), which can be considerably greater than dose during fluoroscopy. There have been over 100 cases of documented radiation skin and underlying tissue injury, a large portion of which resulted in dermal necrosis. The true number of injuries is undoubtedly much higher. The highest dose procedures are complex interventions such as those involving percutaneous angioplasties, stent placements, embolizations, and TIPS. In some cases skin doses have been in excess of 60 Gy (6000 rads). In many instances the procedures have been performed by physicians with little training in radiation effects, little appreciation of the radiation injuries that are possible or the strategies that could have been used to reduce both patient and staff doses. Almost all of the severe injuries that have occurred were avoidable.

Sandfly maxadilan exacerbates infection with Leishmania major and vaccinating against it protects against L. major infection.

Bloodfeeding arthropods transmit many of the world's most serious infectious diseases. Leishmania are transmitted to their mammalian hosts when an infected sandfly probes in the skin for a bloodmeal and injects the parasite mixed with its saliva. Arthropod saliva contains molecules that affect blood flow and modulate the immune response of the host. Indeed, sandfly saliva markedly enhances the infectivity of L. major for its host. If the salivary molecule(s) responsible for this phenomenon was identified, it might be possible to vaccinate the host against this molecule and thereby protect the host against infection with Leishmania. Such an approach represents a novel means of controlling arthropod-borne disease transmission. Here, we report that a single molecule, maxadilan, in sandfly saliva can exacerbate infection with L. major to the same degree as whole saliva, and that vaccinating against maxadilan protects mice against infection with L. major.

Interleukin-6 deficiency influences cytokine expression in susceptible BALB mice infected with Leishmania major but does not alter the outcome of disease.

Since interleukin-6 (IL-6) may promote Th2 responses, we infected BALB IL-6-deficient (IL-6(-/-)) mice with Leishmania major. There was not a significant difference between the courses of infection (lesion size and parasite burden) in IL-6(-/-) and wild-type mice, but IL-6(-/-) mice expressed lower levels of Th2- and Th1-associated cytokines.

Leishmania major induces differential expression of costimulatory molecules on mouse epidermal cells.

Levels of expression of costimulatory molecules have been proposed to influence the outcome of antigen-specific T cell priming. We found that Leishmania major selectively modulated the expression of costimulatory molecules on various populations of epidermal cells. B7.2 expression was down-regulated on Thy1.2+ epidermal cells (keratinocytes) from disease-resistant C3H mice, but not from disease-susceptible BALB/c mice. In addition, epidermal cells from BALB/c mice showed a down-regulation of B7.1 expression on NLDC 145+ Langerhans cells. In vitro T cell priming experiments, using syngeneic epidermal cells as antigen-presenting cells (APC), showed that the production of IFN-gamma was inhibited when either B7.1 or B7.2 signaling pathways were blocked. Blockade of B7.2, but not B7.1, significantly inhibited the ability of epidermal cells to induce IL-4 production from CD4+ T cells. In addition, C3H CD4+ T cells, which were unable to secrete detectable levels of IL-4 in cultures with syngeneic APC, were now able to secrete IL-4 following presentation of L. major antigens by congenic BALB/K epidermal cells. Conversely, C3H epidermal cells supported the priming of BALB/K CD4+ T cells for IL-4 production in vitro. Thus, the differential expression of B7 molecules on epidermal cells may not represent the sole factor governing the polarization of L. major-specific CD4+ T cells in vitro.

Regulation of differentiation to the infective stage of the protozoan parasite Leishmania major by tetrahydrobiopterin.

A critical step in the infectious cycle of Leishmania is the differentiation of parasites within the sand fly vector to the highly infective metacyclic promastigote stage. Here, we establish tetrahydrobiopterin (H4B) levels as an important factor controlling the extent of metacyclogenesis. H4B levels decline substantially during normal development, and genetic or nutritional manipulations showed that low H4B caused elevated metacyclogenesis. Mutants lacking pteridine reductase 1 (PTR1) had low levels of H4B, remained infectious to mice, and induced larger cutaneous lesions (hypervirulence). Thus, the control of pteridine metabolism has relevance to the mechanism of Leishmania differentiation and the limitation of virulence during evolution.

Major histocompatibility complex class II-independent generation of neutralizing antibodies against T-cell-dependent Borrelia burgdorferi antigens presented by dendritic cells: regulation by NK and gammadelta T cells.

We previously showed that adoptive transfer of Borrelia burgdorferi-pulsed dendritic cells (DCs) into syngeneic mice protects animals from challenge with tick-transmitted spirochetes. Here, we demonstrate that the protective immune response is antibody (Ab) dependent and does not require the presence of major histocompatibility complex (MHC) class II molecules on DCs. Mice sensitized with B. burgdorferi-pulsed MHC class II-deficient (MHC class II(-/-)) DCs mounted a humoral response against protective antigens, including B. burgdorferi outer surface protein A (OspA) and OspC. B-cell help for the generation of neutralizing anti-OspC immunoglobulin G Abs could be provided by gammadelta T cells. In contrast, anti-OspA Ab production required the presence of alphabeta T cells, although this pathway could be independent of MHC class II molecules on antigen-presenting cells. Moreover, depletion of NK cells prior to transfer of antigen-pulsed MHC class II(-/-) DCs resulted in significant increases in the levels of neutralizing Abs induced by DCs. Altogether, these data suggest that the initial interactions between DCs and innate immune cells, such as gammadelta and NK cells, can influence the generation of a protective humoral response against B. burgdorferi antigens.

Identification of an IL-2 binding protein in the saliva of the Lyme disease vector tick, Ixodes scapularis.

A potent inhibitor of mitogen-stimulated T cell proliferation exists in the saliva of several species of hard ticks, including the Lyme disease vector tick, Ixodes scapularis. Our characterization of this phenomenon has led to the identification of a possible mechanism for the T cell inhibitory activity of I. scapularis saliva. The T cell inhibitor can overcome stimulation of mouse spleen cells with anti-CD3 mAb; however, a direct and avid interaction with T cells does not appear to be necessary. Tick saliva inhibits a mouse IL-2 capture ELISA, suggesting that a soluble IL-2 binding factor is present in the saliva. This hypothesis was verified by using a direct binding assay in which plate-immobilized tick saliva was shown to bind both mouse and human IL-2. Elimination of the IL-2 binding capacity of saliva in the in vitro assays by trypsin digestion demonstrated that the IL-2 binding factor is a protein. These experiments comprise the first demonstration of the existence of such a secreted IL-2 binding protein from any parasite or pathogen. This arthropod salivary IL-2 binding capacity provides a simple mechanism for the suppression of T cell proliferation as well as for the activity of other immune effector cells that are responsive to IL-2 stimulation. Relevance of the tick T cell inhibitory activity to the human immune system is demonstrated by the ability of tick saliva to inhibit proliferation of human T cells and CTLL-2 cells grown in the presence of human IL-2.

Influence of costimulatory molecules on immune response to Leishmania major by human cells in vitro.

The importance of CD40, CD80, and CD86 costimulatory molecules in anti-Leishmania immune responses has been established in murine models. A role for these costimulatory molecules in human anti-Leishmania immune responses was investigated in this study. Autologous macrophages and peripheral blood leukocytes (PBL) were prepared from peripheral blood mononuclear cells of Leishmania-naive donors and cultured with or without Leishmania major in various combinations. After 7 days of culture, high levels of CD40 and CD86 were expressed on macrophages in the presence or absence of L. major. When macrophages were cultured for an additional 7 days with PBL, expression of all three costimulatory molecules was detected. When L. major was present in these cultures, the expression of CD80, and to a lesser extent CD40, on macrophages was enhanced. Blockade of CD80, CD86, or both molecules (in the order of greatest effect) in cultures containing macrophages, PBL, and L. major significantly inhibited the production of gamma interferon, interleukin-5 (IL-5), and IL-12. Blockade of CD40-CD154 interactions also significantly inhibited production of these cytokines in response to L. major. Production of IL-10 was unaltered by the blockade of these costimulatory molecules. Thus, these data suggest that CD40, CD80, and CD86 expression and regulation may significantly impact anti-Leishmania immune responses in humans.

Artificial systems as models in biological cybernetics.

From the perspective of biological cybernetics, "real world" robots have no fundamental advantage over computer simulations when used as models for biological behavior. They can even weaken biological relevance. From an engineering point of view, however, robots can benefit from solutions found in biological systems. We emphasize the importance of this distinction and give examples for artificial systems based on insect biology.