Immunohistochemical demonstration of keratins in the epidermal layers of the Malayan pangolin (Manis javanica), with remarks on the evolution of the integumental scale armour.

Using immunohistochemistry, the study demonstrates the distribution of keratins (pan-keratin with CK1-8, 10, 14-16, 19; keratins CK1, 5, 6, 9, 10; hair keratins AE13, AE14) in the epidermis of the Malayan pangolin (Manis javanica). A varying reaction spectrum was observed for pan-keratin, with body region-dependent negative to very strong reaction intensities. The dorsolateral epidermis exhibited positive reactions only in its vital layers, whereas the abdominal epidermis showed strong positive reactions in the soft two outer strata. The single acidic and basic-to-neutral (cyto)keratins produced clear variations compared to the pan-keratin tinging. E.g., CK1 appeared in all epidermal layers of both body regions, except for the ventral stratum corneum, whereas CK5, 6, 9, 10 were restricted to the soft ventral epidermis. Here, distinctly positive reactions were confined to the stratum granulosum, except for CK6 that appeared in the soft stratum corneum. A different staining pattern was obvious for the hair keratins, i.e., positive reactions of AE13 concentrated only in the granular layer of the dorsal epidermis. In the abdominal epidermis, remarkable tinging for AE14 was visible in the stratum basale, decreasing toward the corneal layer, but was also found in the outer root sheath cells of the hair follicles in the ventral body part. Our findings are discussed related to the evolution of the horny dorsal scales of the pangolin, which may have started from the tail root, projecting forward to the head.

A covalently cross-linked gel derived from the epidermis of the pilot whale Globicephala melas.

The rheological properties of the stratum corneum of the pilot whale (Globicephala melas) were investigated with emphasis on their significance to the self-cleaning abilities of the skin surface smoothed by a jelly material enriched with various hydrolytic enzymes. The gel formation of the collected fluid was monitored by applying periodic-harmonic oscillating loads using a stress-controlled rheometer. In the mechanical spectrum of the gel, the plateau region of the storage modulus G' (<1200 Pa) and the loss modulus G" (>120 Pa) were independent of frequency (omega = 43.98 to 0.13 rad x s(-1), tau = 15 Pa, T = 20 degrees C), indicating high elastic performance of a covalently cross-linked viscoelastic solid. In addition, multi-angle laser light scattering experiments (MALLS) were performed to analyse the potential time-dependent changes in the weight-average molar mass of the samples. The observed increase showed that the gel formation is based on the assembly of covalently cross-linked aggregates. The viscoelastic properties and the shear resistance of the gel assure that the enzyme-containing jelly material smoothing the skin surface is not removed from the stratum corneum by shear regimes during dolphin jumping. The even skin surface is considered to be most important for the self-cleaning abilities of the dolphin skin against biofouling.

A zymogel enhances the self-cleaning abilities of the skin of the pilot whale (Globicephala melas).

Enzyme activity in the stratum corneum of the pilot whale Globicephala melas was investigated employing colorimetric enzyme screening assays combined with NATIVE PAGE, size exclusion chromatography (SEC) and histochemical staining procedures. Applying different substrates, several enzymes were detected. The histochemical demonstration of some selected hydrolytic enzymes enriched in the stratum corneum showed high extracellular accumulation. As demonstrated by size exclusion chromatography, high molar mass aggregates were built up from a glycoprotein-rich 20-30-kD fraction. Using NATIVE PAGE experiments under non-reducing conditions, a selection of five degrading enzymes was recovered within the above-reported aggregates. Activity of extracellular aggregate-attached enzymes in the superficial layer of the stratum corneum exhibited no remarkable decrease potentially resulting from self-degradation. We thus conclude that due to their enclosure within the microenvironment of aggregates, a zymogel is formed and autolysis of the stratum corneum is reduced. With respect to the skin surface, the zymogel with hydrolytic activities covering major parts of it enhances the self-cleaning abilities of the skin of the pilot whale based on physical pre-requisites by hydrolyzing adhesive glycoconjugates of settling biofouling organisms considered as primary steps in fouling.

Blood cells and plasma proteins of chickens fed a diet supplemented with (1-->3),(1-->6)-beta-D-glucan and enrofloxacin.

The effects of (1-->3),(1-->6)-beta-D-glucan from Saccharomyces cerevisiae and of the fluochinolone enrofloxacin were studied on red and white blood cells and plasma proteins of growing chickens up to the 35th day of life. The prominent findings within the leukocyte population on a per cent scale are: (i) increase of leukocyte count; increase of neutrophils and decrease of lymphocytes in the control and in the antibiotic group from day 17 to day 35; (ii) a minor decrease of neutrophils and no change of lymphocytes in the glucan group; (iii) the monocytes increase from 2.5 +/- 1.8% to 6.5 +/- 7.6% in the glucan group; (iv) the basophils increase in the control group and scale down in the other groups from day 17 to day 35. The total count of leukocytes increases in the controls and in the glucan group. The total protein content of blood plasma, beta-globulin and gamma-globulin increase and the albumin-globulin-ratio and alpha-globulin decline during chickens growth. These changes are most prominent in the glucan group. The haemoglobin concentration shows in all three dietary groups a highly significant increase from day 17 to day 35 by about 17 to 27 per cent; no changes are seen in packed cell volume and number of erythrocytes per litre blood.