Anatomy and muscle activity of the dorsal fins in bamboo sharks and spiny dogfish during turning maneuvers

Stability and procured instability characterize two opposing types of swimming, steady and maneuvering, respectively. Fins can be used to manipulate flow to adjust stability during swimming maneuvers either actively using muscle control or passively by structural control. The function of the dorsal fins during turning maneuvering in two shark species with different swimming modes is investigated here using musculoskeletal anatomy and muscle function. White‐spotted bamboo sharks are a benthic species that inhabits complex reef habitats and thus have high requirements for maneuverability. Spiny dogfish occupy a variety of coastal and continental shelf habitats and spend relatively more time cruising in open water. These species differ in dorsal fin morphology and fin position along the body. Bamboo sharks have a larger second dorsal fin area and proportionally more muscle insertion into both dorsal fins. The basal and radial pterygiophores are plate‐like structures in spiny dogfish and are nearly indistinguishable from one another. In contrast, bamboo sharks lack basal pterygiophores, while the radial pterygiophores form two rows of elongated rectangular elements that articulate with one another. The dorsal fin muscles are composed of a large muscle mass that extends over the ceratotrichia overlying the radials in spiny dogfish. However, in bamboo sharks, the muscle mass is divided into multiple distinct muscles that insert onto the ceratotrichia. During turning maneuvers, the dorsal fin muscles are active in both species with no differences in onset between fin sides. Spiny dogfish have longer burst durations on the outer fin side, which is consistent with opposing resistance to the medium. In bamboo sharks, bilateral activation of the dorsal in muscles could also be stiffening the fin throughout the turn. Thus, dogfish sharks passively stiffen the dorsal fin structurally and functionally, while bamboo sharks have more flexible dorsal fins, which result from a steady swimming trade off. J. Morphol. 274:1288–1298, 2013. © 2013 Wiley Periodicals, Inc.     

Immunohistochemistry of thyroid hormones as a functional parameter in thyroid pathology

The authors study by means of immunoperoxidase method the pattern of thyroglobulin, triiodothyronine and thyroxine distribution in 58 cases of thyroid disorders: 15 euthyroid goiters, 10 Graves' disease, 7 Hashimoto's thyroiditis, 11 folliculo-papillary carcinomas (6 primary tumors and 5 lymph node metastases), 8 follicular carcinomas, 4 anaplastic carcinomas and 3 medullary carcinomas. Thyroglobulin, triiodothyronine and thyroxine were present in most of the thyroid disorders, excepting anaplastic and medullary carcinomas. Thyroglobulin and thyroxine were localized both in the follicular epithelium and in the colloid, whereas triiodothyronine was present especially in the follicular cells. The thyroid hormones distribution in benign lesions is rather similar. In carcinomas, the pattern of thyroglobulin, triiodothyronine and thyroxine is more heterogeneous, but generally the triiodothyronine distribution is similar to that of thyroglobulin. In some carcinomas, triiodothyronine and thyroxine showed a weak or negative immunostaining. The immunoperoxidase method is a valuable tool in the study of functional disturbances in the thyroid pathology and in the diagnosis of thyroid carcinoma metastases as well. Positive thyroid hormones staining clearly indicates the thyroid origin of metastases.     

Bioactive polymers XXX. Immobilization of invertase on the diazonium salt of 4-aminobenzoylcellulose

Invertase was immobilized on diazotized 4-aminobenzoylcellulose. The optimum coupling conditions, namely enzyme concentration, time, and pH, were determined. The temperature and pH value for the maximum activity of the immobilized enzyme were determined and the apparent Michaelis constant was estimated.     

Binding and transcytosis of glycoalbumin by the microvascular endothelium of the murine myocardium: evidence that glycoalbumin behaves as a bifunctional ligand

The binding and transport of glycoalbumin (gA) by the endothelium of murine myocardial microvessels were studied by perfusing in situ 125I-gA or gA-gold complexes (gA-Au) and examining the specimens by radioassays and EM, respectively. After a 3-min perfusion, the uptake of radioiodinated gA is 2.2-fold higher than that of native albumin; it is partially (approximately 55%) competed by either albumin or D-glucose, and almost completely abolished by the concomitant administration of both competitors or by gA. D-mannose and D-galactose are not effective competitors. Unlike albumin-gold complexes that bind restrictively to plasmalemmal vesicles, gA-Au labels the plasma-lemma proper, plasmalemmal vesicles open on the lumen, and most coated pits. Competing albumin prevents gA-Au binding to the membrane of plasmalemmal vesicles, while glucose significantly reduces the ligand binding to plasmalemma proper. Competition with albumin and glucose gives additive effects. Transcytosis of gA-Au, already detected at 3 min, becomes substantial by 30 min. No tracer exit via intercellular junctions was detected. gA-Au progressively accumulates in multivesicular bodies. The results of the binding and competition experiments indicate that the gA behaves as a bifunctional ligand which is recognized by two distinct binding sites: one, located on the plasma membrane, binds as a lectin the glucose residues of gA; whereas the other, confined to plasmalemmal vesicles, recognizes presumably specific domains of the albumin molecule.     

Interstitial deletion (2)(p13p15)

Summary A dysmorphic 5-year-old girl with severe growth and mental deficiency was studied. She presented a de novo interstitial 2p deletion. Karyotype: 46,XX,del(2)(p13p15).     

Dihydroisocoumarins and phthalide from wood samples infested by fungi

Wood samples, infested by fungi during storage, were shown to contain, besides the known 5-methyl-mellein, additional (3R)-8-hydroxy-3-methyl-3,4-dihydroisocoumarins substituted by 7-methyl, 5-formyl, 5-carboxy, 5-hydroxy, 5-methoxy, 6-methoxy-5-methyl and 6,7-dimethoxy-5-methyl groups, as well as 6-formyl-7-hydroxy-5-methoxy-4-methylphthalide. Several 2-methylchromanones were synthesized in order to show that this class of compounds can be distinguished from 3-methyl-3,4-dihydroisocoumarins by MS.     

Studies on the adenosine 3′,5′-monophosphate-dependent protein kinase of Blastocladiella emersonii

Using a combination of Chromatographic and sucrose density gradient techniques under carefully controlled conditions of pH and protease inhibitors, we demonstrate that there is only one form of adenosine 3′,5′-monophosphate-dependent protein kinase in the cytosol fraction of the Blastocladiella emersonii zoospore. If any of these conditions are omitted during extract preparation, one obtains what are apparently multiple forms of the enzyme, which are in reality artifacts due to extensive endogenous proteolytic activity. This endogenous protease is stimulated by alkaline pH and inhibited by antipain. The zoospore protein kinase is similar to type II protein kinase from mammalian cells in several aspects including Chromatographic behavior on DEAE-cellulose column, conditions for subunit dissociation and reassociation, as well as the molecular weight value of the regulatory subunit.     

Cyclic AMP-dependent and -independent protein kinases of the water mold, Blastocladiella emersonii.

Protein kinase (ATP:protein phosphotransferase, EC 2.7.1.37) and cyclic adenosine 3',5'-monophosphate binding activities have been identified in zoospore extracts of the water mold Blastocladiella emersonii. More than 75% of these activities is found in the soluble fraction. Soluble protein kinase activity is resolved in three peaks(I, II and III) by DEAE-cellulose chromatography. Peak I is casein dependent and insensitive to cyclic AMP. Peak II is histone dependent and cyclic AMP independent; this enzyme is inhibited by the heat-stable inhibitor from bovine muscle. Peak III utilizes histone as substrate and is activated by cyclic AMP.     

Differential effects of manganese ions on Blastocladiella emersonii adenylate cyclase.

Adenylate cyclase (ATP pyrophosphate-lyase (cyclizing), EC 4.6.1.1) activity in Blastocladiella emersonii is associated with particulate subcellar fractions. Solubilization after treatment with detergent suggests its localization in a membrane fraction of the zoospore homogenate. The enzyme specifically requires Mn2+ for activity and is not stimulated by NaF. The kinetic characteristics of substrate utilization by B. emersonii adenylate cyclase were investigated with various concentrations of ATP and Mn2+, and in the presence of inhibitors. Plots of enzyme activity versus the actual concentration of the MnATP2- complex give sigmoid curves. An excess of Mn2+ activates the enzyme at low concentrations of substrate and leads to a modification of the enzyme kinetics. The nucleotides 5'-AMP and GTP were shown to be competitive inhibitors of the enzyme. In addition, kinetic data, obtained under conditions in which an inhibitor (ATP) is added in constant proportion to the variable substrate (MnATP2-) concentration, produced reciprocal plots that were linear and intersecting to the right of the ordinate, and secondary replots that were hyperbolic. These kinetic patterns support a model in which: MnATP2- is the substrate; free Mn2+ is an activator at low substrate concentrations, but an inhibitor at high substrate concentrations; and free ATP is not an efficient inhibiyor (Ki greater than 1.10(-4) M).