Multiscale head anatomy of Megaphragma (Hymenoptera: Trichogrammatidae).

Methods of three-dimensional electron microscopy have been actively developed recently and open up great opportunities for morphological work. This approach is especially useful for studying microinsects, since it is possible to obtain complete series of high-resolution sections of a whole insect. Studies on the genus Megaphragma are especially important, since the unique phenomenon of lysis of most of the neuron nuclei was discovered in species of this genus.

Extremely small wasps independently lost the nuclei in the brain neurons of at least two lineages.

Anucleate animal cells are a peculiar evolutionary phenomenon and a useful model for studying cellular mechanisms. Anucleate neurons were recently found in one genus of miniature parasitic wasps of the family Trichogrammatidae, but it remained unclear how widespread this phenomenon is among other insects or even among different tissues of the same insect species. We studied the anatomy of miniature representatives of another parasitic wasp family (Hymenoptera: Mymaridae) using array tomography and found two more species with nearly anucleate brains at the adult stage.

Anatomy of the miniature four-legged mite Achaetocoptes quercifolii (Arachnida: Acariformes: Eriophyoidea).

Miniaturization is one of the important trends in the evolution of terrestrial arthropods. In order to study adaptations to microscopic sizes, the anatomy of the smallest insects was previously studied, but not the anatomy of the smallest mites. Some of the smallest mites are Eriophyidae.

The 3D ultrastructure of the chordotonal organs in the antenna of a microwasp remains complex although simplified.

Insect antennae are astonishingly versatile and have multiple sensory modalities. Audition, detection of airflow, and graviception are combined in the antennal chordotonal organs. The miniaturization of these complex multisensory organs has never been investigated.

Metamorphosis and denucleation of the brain in the miniature wasp Megaphragma viggianii (Hymenoptera: Trichogrammatidae).

Holometabolan brains undergo structural and allometric changes and complex reorganizations during metamorphosis. In minute egg parasitoids, brain formation is shifted to the late larva and young pupa, due to extreme de-embryonization. The brains of Megaphragma wasps undergo denucleation, the details of which remained unknown.

Regio- and stereoselective (3 + 2)-cycloaddition reactions of nitrones with cyclic allenes.

An effective approach to access functionalized 2-cyclonona(deca)[]isoxazoles and 15-oxo-3,10-methanobenzo[][1]azacyclododecines has been developed by the reaction of -aryl-,-bis(methoxycarbonyl)nitrones with cyclonona(deca)-1,2-dienes in a one-pot fashion. The reaction of -aryl--(phenylcarbamoyl)nitrones with these allenes proceeds strictly regioselectively giving the mixtures of diastereomeric isoxazolidines containing a double bond at the C-position of the isoxazolidine ring. The quantum chemical calculations show that the regioselectivity of these reactions is in good agreement with the reactivity indices of the considered compounds.

Small brains for big science.

As the study of the human brain is complicated by its sheer scale, complexity, and impracticality of invasive experiments, neuroscience research has long relied on model organisms. The brains of macaque, mouse, zebrafish, fruit fly, nematode, and others have yielded many secrets that advanced our understanding of the human brain. Here, we propose that adding miniature insects to this collection would reduce the costs and accelerate brain research.

Protocol for preparation of heterogeneous biological samples for 3D electron microscopy: a case study for insects.

Modern morphological and structural studies are coming to a new level by incorporating the latest methods of three-dimensional electron microscopy (3D-EM). One of the key problems for the wide usage of these methods is posed by difficulties with sample preparation, since the methods work poorly with heterogeneous (consisting of tissues different in structure and in chemical composition) samples and require expensive equipment and usually much time. We have developed a simple protocol allows preparing heterogeneous biological samples suitable for 3D-EM in a laboratory that has a standard supply of equipment and reagents for electron microscopy.

Constant neuropilar ratio in the insect brain.

Revealing scaling rules is necessary for understanding the morphology, physiology and evolution of living systems. Studies of animal brains have revealed both general patterns, such as Haller's rule, and patterns specific for certain animal taxa. However, large-scale studies aimed at studying the ratio of the entire neuropil and the cell body rind in the insect brain have never been performed.

Metamorphosis of the central nervous system of Trichogramma telengai (Hymenoptera: Trichogrammatidae).

During metamorphosis, the insect CNS undergoes both structural and allometric changes. Due to their extreme de-embryonization and parasitism, the formation of the CNS in egg parasitoids occurs at the late larval stage. Our study provides the first data on the morphological and volumetric changes of the CNS occurring during the pupal development of the parasitic wasp Trichogramma telengai Sorokina, 1987 (Trichogrammatidae).

Morphology and scaling of compound eyes in the smallest beetles (Coleoptera: Ptiliidae).

The coleopteran family Ptiliidae (featherwing beetles) includes some of the smallest insects known with most of the representatives of this family measuring less than 1 mm in body length. A small body size largely determines the morphology, physiology, and biology of an organism and affects the organization of complex sense organs. Information on the organization of the compound eyes of Ptiliidae is scarce.

Between extreme simplification and ideal optimization: antennal sensilla morphology of miniaturized wasps (Hymenoptera: Trichogrammatidae).

One of the major trends in the evolution of parasitoid wasps is miniaturization, which has produced the smallest known insects. spp. (Hymenoptera: Trichogrammatidae) are smaller than some unicellular organisms, with an adult body length of the smallest only 170 µm.

Cognitive abilities with a tiny brain: Neuronal structures and associative learning in the minute Nephanes titan (Coleoptera: Ptiliidae).

Revealing the effect of brain size on the cognitive abilities of animals is a major challenge in the study of brain evolution. Analysis of the effects of miniaturization on brain function in the smallest insects is especially important, as they are comparable in body size to some unicellular organisms and next to nothing is known about their cognitive abilities. We analyse for the first time the structure of the brain of the adult featherwing beetle Nephanes titan, one of the smallest insects, and results of the first ethological experiments on the capacity of learning in this species.

Ultraviolet Radiation Inhibits Mammary Carcinogenesis in an ER-Negative Murine Model by a Mechanism Independent of Vitamin D.

Three decades ago, the Garlands postulated that vitamin D produced in the skin by ultraviolet radiation (UVR)-induced conversion of 7-dehydrocholesterol to pre-D has anticancer effects, thus triggering more than 9,500 publications on D and cancer. Here, we report that UVR treatment of transgenic mice of the well-established C3(1)/SV40 Tag mammary cancer model significantly inhibits both autochthonous carcinogenesis and allograft tumor growth, but in contrast neither dietary nor topical D influences mammary carcinogenesis in this specific mouse model. Furthermore, UVR's inhibitory effects occur irrespective of whether or not the treatment increases circulating D in the mice.

Vitamin D Produced by Skin Exposure to UVR Inhibits Murine Basal Cell Carcinoma Carcinogenesis.

The effect of UVR on human basal cell carcinoma (BCC) epidemiology is complex-the incidence rises until approximately 30,000 hours of lifetime sunlight exposure and then plateaus. We hypothesize that UVR has opposing effects on BCC carcinogenesis-stimulatory via mutagenesis and inhibitory via production of hedgehog-inhibiting vitamin D (D). We find that UVR exposure of ionizing radiation-treated Ptch1 mice accelerates BCC carcinogenesis in male mice, in which UVR does not produce D.

Comparison of Geant4 multiple Coulomb scattering models with theory for radiotherapy protons.

Usually, Monte Carlo models are validated against experimental data. However, models of multiple Coulomb scattering (MCS) in the Gaussian approximation are exceptional in that we have theories which are probably more accurate than the experiments which have, so far, been done to test them. In problems directly sensitive to the distribution of angles leaving the target, the relevant theory is the Molière/Fano/Hanson variant of Molière theory (Gottschalk et al 1993 Nucl.

Attenuation of UVR-induced vitamin D synthesis in a mouse model deleted for keratinocyte lathosterol 5-desaturase.

The lower risk of some internal cancers at lower latitudes has been linked to greater sun exposure and consequent higher levels of ultraviolet radiation (UVR)-produced vitamin D (D). To separate the experimental effects of sunlight and of all forms of D, a mouse in which UVR does not produce D would be useful. To this end we have generated mice carrying a modified allele of sterol C5-desaturase (Sc5d), the gene encoding the enzyme that converts lathosterol to 7-dehydrocholesterol (7-DHC), such that Sc5d expression can be inactivated using the Cre/lox site-specific recombination system.

The scaling and allometry of organ size associated with miniaturization in insects: A case study for Coleoptera and Hymenoptera.

The study of the influence of body size on structure in animals, as well as scaling of organs, is one of the key areas of functional and evolutionary morphology of organisms. Most studies in this area treated mammals or birds; comparatively few studies are available on other groups of animals. Insects, because of the huge range of their body sizes and because of their colossal diversity, should be included in the discussion of the problem of scaling and allometry in animals, but to date they remain insufficiently studied.

Validation of nuclear models in Geant4 using the dose distribution of a 177 MeV proton pencil beam.

A proton pencil beam is associated with a surrounding low-dose envelope, originating from nuclear interactions. It is important for treatment planning systems to accurately model this envelope when performing dose calculations for pencil beam scanning treatments, and Monte Carlo (MC) codes are commonly used for this purpose. This work aims to validate the nuclear models employed by the Geant4 MC code, by comparing the simulated absolute dose distribution to a recent experiment of a 177 MeV proton pencil beam stopping in water.

Comparative morphological analysis of compound eye miniaturization in minute hymenoptera.

Due to their small size, diminutive parasitic wasps are outstanding subjects for investigating aspects of body miniaturization. Information on minute compound eyes is still scarce, and we therefore investigated eye morphology in one of the smallest known hymenopteran species Megaphragma mymaripenne (body size 0.2 mm) relative to Anaphes flavipes (body size 0.

Urokinase-type plasminogen activator (uPA) induces pulmonary microvascular endothelial permeability through low density lipoprotein receptor-related protein (LRP)-dependent activation of endothelial nitric-oxide synthase.

Urokinase plasminogen activator (uPA) and PA inhibitor type 1 (PAI-1) are elevated in acute lung injury, which is characterized by a loss of endothelial barrier function and the development of pulmonary edema. Two-chain uPA and uPA-PAI-1 complexes (1-20 nM) increased the permeability of monolayers of human pulmonary microvascular endothelial cells (PMVECs) in vitro and lung permeability in vivo. The effects of uPA-PAI-1 were abrogated by the nitric-oxide synthase (NOS) inhibitor L-NAME (N(D)-nitro-L-arginine methyl ester).

How immune peptidases change specificity: cathepsin G gained tryptic function but lost efficiency during primate evolution.

Cathepsin G is a major secreted serine peptidase of neutrophils and mast cells. Studies in Ctsg-null mice suggest that cathepsin G supports antimicrobial defenses but can injure host tissues. The human enzyme has an unusual "Janus-faced" ability to cleave peptides at basic (tryptic) as well as aromatic (chymotryptic) sites.

Alpha 2-macroglobulin capture allows detection of mast cell chymase in serum and creates a reservoir of angiotensin II-generating activity.

Human chymase is a highly efficient angiotensin II-generating serine peptidase expressed by mast cells. When secreted from degranulating cells, it can interact with a variety of circulating antipeptidases, but is mostly captured by alpha(2)-macroglobulin, which sequesters peptidases in a cage-like structure that precludes interactions with large protein substrates and inhibitors, like serpins. The present work shows that alpha(2)-macroglobulin-bound chymase remains accessible to small substrates, including angiotensin I, with activity in serum that is stable with prolonged incubation.