The Cuticles of (?) Thylacocephalan Arthropod from the Basal Choteč Event (Choteč Formation, Eifelian; Barrandian Area, Czech Republic)

Small fragments of phosphatic cuticle have been observed in dark limestone of the early Eifelian age (Choteč Formation) in the interval of the Basal Choteč Event. The cuticle is two-layered, primarily folded, with a chamber between outer and inner walls. Fragments likely represent small cuticle pieces from the margins of the carapace. The exterior of the cuticle is nearly smooth bearing irregular network of wrinkled polygons or shallow pits. Low conical mound-like to high thorn-like spines with annular structure extend from both outer and inner surface of cuticle. Wrinkled and folded bases of these spines indicate moderate flexibility of cuticle. Spines are hollow, the higher ones often with apical opening. The inner surface of carapace carries smaller spines or is nearly smooth. Chamber walls inside the cara-pace are with folds and other structures supporting stiffness of the cuticle. The internal walls of the cuticle are covered by polygonal bumps. These uniformly sized and shaped bumps are about 1 μm sized and likely represents imprints of the epithelial cells adjoined to the basal membranous layer of endocuticle.Biological affinity of cuticle fragments is unclear. They surely represent pieces of the arthropod cara-pace, the most probably a thylacocephalan. Associated fossils indicate a deeper marine environment. Bloom of prasinophytes, abundance of dacryoconarids and organophosphatic brachiopods, and striking rarity and diminutive size of other fauna indicate eutrophic conditions in a neritic sea, likely with hypoxic bottom water. Nectonic mode of life in open sea can be suggested for an animal bearing this cuticle.

Forces Required to Pull the Superficial Fascia in Facelifts

Purpose: The aims of this study were to characterize the histology of the sideburn and cheek area and to measure the force required to pull the superficial fascia (SF) of Asians in facelift procedures. Methods: The hemiface of a formalin-fixed Korean male adult cadaver (77 years old) was used to study the histology of the sideburn and cheek area. In 42 patients during facelift procedures, the force needed to pull the overlying skin at the midpoint between the sideburn and nasolabial fold 2 mm was measured using a tensiometer. Results: In the cheek, the superficial fatty layer of the superficial fascia (SFS) was found to maintain its thickness throughout the region between the dermis and the membranous layer of the superficial fascia (MSF). The MSF was continuous with the superficial temporal fascia (STF). In the sideburn, the MSF and parotid fascia closely adhered to each other. The force required to move the overlying skin 2 mm when pulling the MSF (10.27 ± 3.64 N) was more than twice as great (217%) as the force required when pulling the SFS (4.73 ± 2.15 N; P < .001). The forces required when pulling the MSF and SFS to move the overlying skin 2 mm were significantly greater in the sideburn area (11.56 ± 3.37 N and 5.52 ± 2.08 N, respectively) than in the cheek area (8.97 ± 3.43 N and 5.52 ± 2.08 N, respectively; P < .001). Conclusion: When lifting the SF at the cheek or sideburn area, lifting the SFS requires less tension than MSF to move the overlying skin. In the cheek area, less tension is needed to move the overlying skin than in the sideburn area.

Embryonic and larval development of an endangered catfish, Horabagrus brachysoma

The fertilised eggs of Asian sun catfish, Horabagrus brachysoma (Günther 1864) were demersal and pale yellow in colour with equal perivitelline space. First cleavage appeared at 49 min (± 3 min) and the size of the blastomeres reduced as the development stage proceeded. Morula stage was reached 3 h 37 min (± 15 min) post-fertilization. The embryonic development from morula to hatching took about 16-17 h. The hatching of eggs started at 20 h 46 min (± 28 min) post-fertilization. The newly hatched yolk-sac larvae were 3-4 mm in length. A membranous layer was found covering from behind the head to posterior part of yolk-sac. Eye, mouth, alimentary canal, barbells and pectoral fins were appeared in the 3 days after hatch (dah). The membranous layer started rupturing at fifth day of post-hatch and disappeared during 9-12 dah with the appearance of fins in different parts of body. Pigments on dorsal side of body appeared in 2 dah larvae and the 10-12 dah larva looked pale brown in colour. After 12 dah, the larva morphologically resembled like an adult fish.

Anatomical study of superficial fascia and localized fat deposits of abdomen

ABSTRACT Background: The development of liposuction and abdominoplasty has renewed interest in the anatomy of the localized fat deposits (LFD) areas of the abdomen. This study aims at ascertaining the gross anatomy of superficial fascia and the localized fat deposits of abdomen. Materials and Methods: Eight adult cadavers (four males and four females) were dissected. Attachments, number of layers of fascia and colour, shape and maximum size of the fat lobules in loin, and upper and lower abdomen were noted. Thickness of deep membranous layer of superficial fascia of upper abdomen and lower abdomen were measured by metal casing electronic digital calipers, with resolution being 10 μm. The independent sample t-test, ANOVA for comparison and Pearson coefficient for correlation were used. Results: Superficial fascia of the abdomen was multilayered in the midline and number of layers reduced laterally. The shape, size, color, and arrangement of fat lobules were different in different locations. The thickness of the fascia of the lower abdomen in males (mean 528.336 ± SE38.48) was significantly (P<0.041) more than that in females. (Mean 390.822 ± SE36.24). Pearson correlation between thickness of the membranous layer of the upper and lower abdomen revealed moderately positive correlation (r=0.718; P<0.045). Conclusions: The LFD in the central region of the abdomen corresponds to the area of multilayered fascia with smaller fat lobules. The relatively thinner supporting fascia of the lower abdomen in females may be responsible for excessive bulges of the lower abdomen. The fat lobule anatomy at different sites under study was different.

Cuticular structure in Costacopluma mexicana Vega and Perrilliat, from the Difunta Group (Maastrichtian) of northeastern Mexico, and its paleoenvironmental implications

Examination of extremely well-preserved cuticle samples from the Maastrichtian retroplumid crab, Costacopluma mexicana Vega and Perrilliat, collected in the Difunta Group in Nuevo León State, Mexico, documents the preservation of corpses in an anoxic microenvironment produced by decomposition of soft tissue of the organisms. All four cuticular layers, epicuticle, exocuticle, endocuticle, and membranous layer, as well as pore canals and tegumental glands, can be recognized. There is no evidence of resorption that accompanies molting. X-ray analysis of the cuticle indicates that the organic matrix was replaced by carbonate-hydroxyapatite, that the original calcitic material was replaced by quartz, and that the replacement proceeded from the outer and inner surfaces of the cuticle toward the interior. The specimens were interpreted to have been preserved in an organic-rich, restricted lagoon in which pH was changed by periodic influxes of fresh water.

Tumors of the lateral wall of the cavernous sinus

✓ The lateral dural wall of the cavernous sinus is composed of two layers, the outer dural layer (dura propria) and the inner membranous layer. Tumors arising from the contents of the lateral dural wall are located between these two layers and are classified as interdural. They are in essence extradural/extracavernous. The inner membranous layer separates these tumors from the venous channels of the cavernous sinus. Preoperative recognition of tumors in this location is critical for selecting an appropriate microsurgical approach. Characteristics displayed by magnetic resonance imaging show an oval-shaped, smooth-bordered mass with medial displacement but not encasement of the cavernous internal carotid artery. Tumors in this location can be resected safely without entering the cavernous sinus proper by using techniques that permit reflection of the dura propria of the lateral wall (methods of Hakuba or Dolenc). During the last 5 years, the authors have identified and treated five patients with interdural cavernous sinus tumors, which included two trigeminal neurinomas arising from the first division of the fifth cranial nerve, two epidermoid tumors, and one malignant melanoma presumed to be primary. The pathoanatomical features that make this group of tumors unique are discussed, as well as the clinical and radiological findings, and selection of the microsurgical approach. A more favorable prognosis for tumor resection and cranial nerve preservation is predicted for interdural tumors when compared with other cavernous sinus tumors.

FACTORS AFFECTING THE INTRACELLUALR SYNTHESIS OF KYNURENINE

Near the time of pupation, autofluorescent kynurenine globules appear in the cells in the anterior region of the fatbody of Drosophila melanogaster. It has been reported previously that kynurenine synthesis may be induced in an additional group of fat cells by feeding the precursor tryptophan to Drosophila larvae, and that this induction of kynurenine production viewed within the fat cells is correlated with an increase in tryptophan pyrrolase activity. In the present report, conditions are outlined which result in the appearance of kynurenine in all of the fat cells. The number of cells in the fatbody which contain kynurenine is influenced by the quantity of tryptophan included in the diet, as well as by the developmental stage at the time of treatment and the duration of the feeding period on the inducer. Physical barriers modifying permeability, such as the membranous layer noted surrounding the fatbody, may be a factor in the regulation of the time and nature of the cellular induction of kynurenine synthesis. Another factor to be considered is the possibility of interference with the availability of tryptophan as a substrate or inducer for this synthesis within the cell. It is suggested that the occurrence of pteridines in some of the fat cells may modify the response of these cells to produce kynurenine, since pteridines as electron acceptors can complex with tryptophan as an electron donor. Kynurenine may be produced in the fat cells under in vitro conditions when they are incubated with L-tryptophan, but kynurenine is not formed when fat cells are incubated with D-tryptophan. The in vitro studies further demonstrate that induction of kynurenine synthesis may occur in fat cells isolated from young larvae in contrast, to in vivo conditions in which inducer does not effect an earlier appearance of kynurenine in the larval fatbody.