Continuous spermatogenesis and the germ cell development strategy within the testis of the Jamaican Gray Anole, Anolis lineatopus.

Testicular tissues from Anolis lineatopus were examined histologically to determine testicular structure, germ cell morphologies, and the germ cell development strategy employed during spermatogenesis. Anoles (N=36) were collected from southern Jamaica from October 2004 to September 2005. Testes were extracted and fixed in Trump's fixative, dehydrated, embedded in Spurr's plastic, sectioned, and stained with basic fuchsin/toluidine blue. The testes of Jamaican Anoles were composed of seminiferous tubules lined with seminiferous epithelia, similar to birds and mammals, and were spermatogenically active during every month of the year. However, spermatogenic activity fluctuated based on morphometric data for February, May and June, and September-December. Sequential increases for these months and decreases in between months in tubular diameters and epithelial heights were due to fluctuations in number of elongating spermatids and spermiation events. Cellular associations were not observed during spermatogenesis in A. lineatopus, and three or more spermatids coincided with mitotic and meiotic cells within the seminiferous epithelium. Although the germ cell generations were layered within the seminiferous epithelium, similar to birds and mammals, the actual temporal development of germ cells and bursts of sperm release more closely resembled that reported recently for other reptilian taxa. All of these reptiles were temperate species that showed considerable seasonality in terms of testis morphology and spermatogenesis. The Jamaican Gray Anole has continuous spermatogenesis yet maintains this temporal germ cell development pattern. Thus, a lack of seasonal spermatogenesis in this anole seems to have no influence on the germ cell development strategy employed during sperm development.

Eggs of the stink bug Acrosternum (Chinavia) marginatum (Hemiptera: Pentatomidae): a scanning electron microscopy study.

The morphology of the outer face of the eggshell, its appearance in cross fractures and the surface morphology of the inner face are described in the green stink bug Acrosternum (Chinavia) marginatum (Hemiptera: Pentatomidae) using scanning electron microscopy. Deposited eggs are barrel-shaped and the surface consists of hexagonally arranged, funnel-shaped pits that possess transverse diaphragms in their slender, basal portions. Only minor differences are detectable between the central portion of the anterior plate (the operculum) and the lateral wall together with the basal portion of the eggshell. The rim at the anterior pole of the egg carries processes with a bulbous end, the aero-micropylar processes. A narrow band of the anterior plate bordering these processes shows hexagonally arranged elements. These differ from those of the operculum and the lateral wall, in that cylindrical pits are abundant. During hatching, the operculum is lifted precisely at the rim of this area. Inspection of the periphery of the inner face of the operculum reveals slender, radially arranged grooves. Their arrangement and spacing indicate that they bear a spatial relationship with the aero-micropylar processes. Their role may lie in guiding the sperm to the site where fertilization occurs and in facilitating the gas exchange of the embryo. The remainder of the eggshell carries shallow elevations at its inner face. Exterior and interior features of the eggshell, as well as its appearance in cross-fractures, are discussed.

Fractional Fourier transforms in two dimensions.

We analyze the fractionalization of the Fourier transform (FT), starting from the minimal premise that repeated application of the fractional Fourier transform (FrFT) a sufficient number of times should give back the FT. There is a qualitative increase in the richness of the solution manifold, from U(1) (the circle S1) in the one-dimensional case to U(2) (the four-parameter group of 2 x 2 unitary matrices) in the two-dimensional case [rather than simply U(1) x U(1)]. Our treatment clarifies the situation in the N-dimensional case. The parameterization of this manifold (a fiber bundle) is accomplished through two powers running over the torus T2 = S1 x S1 and two parameters running over the Fourier sphere S2. We detail the spectral representation of the FrFT: The eigenvalues are shown to depend only on the T2 coordinates; the eigenfunctions, only on the S2 coordinates. FrFT's corresponding to special points on the Fourier sphere have for eigenfunctions the Hermite-Gaussian beams and the Laguerre-Gaussian beams, while those corresponding to generic points are SU(2)-coherent states of these beams. Thus the integral transform produced by every Sp(4, R) first-order system is essentially a FrFT.

The architecture of the anterior appendage in the egg of the assassin bug, Zelus longipes (Hemiptera: Reduviidae).

The eggshell of Zelus longipes, a Hemiptera species of the family Reduviidae (assassin bugs), has been studied using Scanning Electron Microscopy (SEM). The emphasis was on the architecture of an anterior appendage connected to the main eggshell of both ovarian and deposited eggs. The analysis of eggs fractured at various angles and levels reveals a relatively complex organization of this appendage. There is a cylindrical outer layer, the veil, of roughly the same diameter as, and continuous with, the main eggshell. At its anterior pole, the veil folds inwards and forms an hourglass-shaped tube that is attached through slender extensions to a curved plate oriented at right angles to the long axis of the egg and spanning the internal diameter of the veil. The plate is solid at the center, shows honeycomb-shaped perforations in its mid-section and contains a very delicate meshwork along its circumference. Underneath the plate lies a hollow cylinder oriented at right angles to the long axis of the egg and attached to the anterior plate of the egg, the operculum. The outer openings of aeropyles lie at the inner face of the veil and at its base. While the outer surface of the entire eggshell appears smooth, the inner face of the anterior appendage is highly and diversely sculptured. The eggs are deposited in batches of at least 15 and completely surrounded by viscous secretion. This substance does not encroach on the anterior appendage. The major function of this appendage may lie in the protection of the aeropyles and particularly in preventing their being clogged by the viscous material.

Two novel alpha-neurotoxins isolated from the taipan snake, Oxyuranus scutellatus, exhibit reduced affinity for nicotinic acetylcholine receptors in brain and skeletal muscle.

Three novel toxic peptides were purified to homogeneity from the venom of the Australian taipan snake, Oxyuranus scutellatus scutellatus. On the basis of complete amino acid sequence analyses, two of these toxins belong to the family of short-chain alpha-neurotoxins found in elapid and hydrophid snake venoms and are the first postsynaptic neurotoxins identified in taipan venom. Radioligand binding studies confirm that taipan toxins 1 and 2 inhibit the binding of [125I]-alpha-bungarotoxin to nicotinic acetylcholine receptors in skeletal muscle with IC50 values of 2.4-2.5 nM but are 5-fold less potent in this assay than alpha-bungarotoxin or the two short-chain alpha-neurotoxins erabutoxin a and erabutoxin b. Taipan toxins 1 and 2 do not antagonize [125I]-alpha-bungarotoxin binding to central neuronal nicotinic receptors at concentrations up to 3 microM. We find that erabutoxin a and erabutoxin b do inhibit the binding of [125I]-alpha-bungarotoxin to central neuronal nicotinic receptors but are over 350-fold less potent than long-chain alpha-neurotoxins at these receptors. The novel alpha-neurotoxins from taipan venom do not inhibit the binding of [3H]nicotine to high-affinity nicotine receptors in brain, a property they share with alpha-bungarotoxin and the erabutoxins. The results demonstrate that at least two neuromuscular junction-blocking peptides are present in taipan venom. Nonconservative substitutions at position 32 in both taipan toxin 1 and 2 may be responsible for the observed decreases in affinities of the toxins of 5-fold for muscle receptors (compared to alpha-bungarotoxin) and over 10-fold for alpha-bungarotoxin-sensitive nicotinic receptors in brain (compared to the structurally similar short-chain alpha-neurotoxins erabutoxin a and erabutoxin b).

Prolonged delirium tremens requiring massive doses of medication.

Delirium tremens might last for weeks and treatment requires massive benzodiazepine doses, yet it is possible to manage patients with this condition successfully. In this case of delirium tremens, standard agents at the usual recommended doses were not sufficient to achieve control of confusion and agitation or to stabilize neurologic and cardiovascular parameters. The patient required extraordinarily high doses of central nervous system depressants for an extended period. Midazolam, a short-acting benzodiazepine, was used but was associated with metabolic acidosis and was extremely expensive. Although high-dose midazolam should probably be avoided, extremely high dose benzodiazepine use for an extended period might be necessary in some cases. In this circumstance we advise diazepam because of its low cost and relative safety. The tendencies to withhold large doses for fear of side effects or to give up in cases requiring prolonged intensive support must be resisted to minimize the mortality from this severe illness.

Cutaneous angiosarcoma. A literature review and case report.

A case of angiosarcoma of the lower extremity was presented. This rare but highly malignant soft tissue tumor usually presents as a raised pigmented lesion. Wide surgical excision or amputation is the treatment of choice. Radiotherapy may offer some relief in cases that are inoperable.