Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Beak”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 163 records · Page 9Linked to original sources

Immunohistochemical characteristics of cutaneous Herbst corpuscles from beak and rictus in domestic pigeon.

Herbst corpuscles are the avian equivalent to the mammalian Pacinian corpuscles. In this study we used indirect peroxidase-anti peroxidase (PAP) immunohistochemistry to analyze the distribution in the pigeon cutaneous Herbst corpuscles, of several markers which are known to specifically label the axon, the Schwann-related and perineurial-related cells in Pacinian corpuscles. The distribution of the assessed antigens on Herbst corpuscles was as follows: i) the central axon displayed positive immunoreactivity for neurofilament proteins and neuron specific enolase; ii) the lamellar cells forming the inner-core were positive for S-100 protein and vimentin, whereas fibroblast surrounding them were vimentin and epithelial membrane antigen positive; iii) the capsule was focally immunolabelled for vimentin, and regularly for epithelial membrane antigen. No immunoreactivity was found neither for cytokeratins nor for glial fibrillary acidic protein. These observations demonstrate that the immunohistochemical profile of cutaneous (beak skin and rictus) Herbst corpuscles in pigeon is similar to that of the mammalian Pacinian corpuscles.

Animals↗

Psittacine beak and feather disease virus nucleotide sequence analysis and its relationship to porcine circovirus, plant circoviruses, and chicken anaemia virus.

Cloning and sequencing of the circular, single-stranded DNA of one isolate of psittacine beak and feather disease virus (BFDV) demonstrate a genome composed of a circular molecule of 1993 nucleotide bases. An analysis of the assembled replicative form demonstrated seven open reading frames (ORFs) (three in the virion strand and four in the complementary strand), potentially encoding seven viral proteins of >8.7 kDa. High amino acid sequence similarity was demonstrated between a potential 33.3-kDa protein product of ORF1 of BFDV and the replicase-associated protein of porcine circovirus (PCV), subterranean clover stunt virus, and faba bean necrotic yellows virus. However, significant similarity in nucleotide or amino acid sequences was not present between BFDV and chicken anaemia virus. A potential stem-loop structure similar to that found in PCV and plant circoviruses was present in the putative encapsidated strand of the BFDV genome. At the top of this structure, a nonanucleotide motif (TAGTATTAC) similar to that of PCV, plant circoviruses, and geminiviruses also was recognised. Comparison of the deduced amino acid sequences of ORF2 of BFDV and PCV demonstrated 29.1% identity, and in both viruses, ORF2 is located on the complementary strand, beginning close to or within the hairpin stem. Our findings provide further evidence of a close relationship among BFDV, PCV, and plant circoviruses but not chicken anaemia virus.

Amino Acid Sequence↗

Hypertrophy of the talar beak.

Hypertrophy of the talar beak is the product of traction of the insertion of the joint capsule. It is commonly seen in athletes and may be entirely asymptomatic despite its size. It should not be mistaken for spurring of the articular margin of the talus which is seen in tarsal coalition.

Bone Diseases↗

Beak sign in duodenal duplication cyst.

Duodenal duplication cyst is an uncommon congenital anomaly of the alimentary tract and preoperative diagnosis is important in relation to the surgical approach. This paper describes a beak-like projection of the duodenum in contrast studies which enabled a confident preoperative diagnosis of duodenal duplication cyst in four infants.

Cysts↗

Thick skin and cosmetic surgery of the nasal tip: how to avoid the cutaneous polly beak.

Although thick skin is generally considered a disadvantage in cosmetic surgery of the nasal tip, responsible for the supra tip deformity known as "polly beak" and other aesthetic defects, there are surgical guidelines that can greatly reduce the occurrence of these problems, the most interesting of which is grafting. On the contrary, thick skin could even be considered an advantage, if it masks amputated cartilaginous margins following any dome-sectioning technique.

Adipose Tissue↗

Distinctive medium chain wax esters, triglycerides, and diacyl glyceryl ethers in the head fats of the Pacific beaked whale, Berardius bairdi.

Lipids were extracted from the mandibular fat body (jaw), the fatty forehead (melon), and the dorsal blubber of a Pacific beaked whale (Berardius bairdi) and separated into lipid classes by preparative thin layer chromatogrphy. The head fats were mixtures of wax esters and triglycerides with a very small amount of diacyl glyceryl ether. The blubber fat contained 97% wax ester and 3% triglyceride. Gas liquid chromatography (GLC) of the intac lipid classes indicated an unusually low C26-C30 range for most of the jaw and melon wax esters compared to the more normal C32-C40 molecules found in the blubber. Distinctive lower molecular weight C24-C40 triglycerides occurred in the head fats vs. the usual C44-C58 range in the blubber. Most diacyl glyceryl ethers were in the C35-C46 range, below the molecular weight of hexadecyldipalmitoyl glyceryl ether (C48). GLC of the derived fatty acid methyl esters showed that the lower molecular weight neutral lipids in the head fats were due to high levels of iso-10:0, n-10:0, iso-11:0, iso-12:0, N-12:0, and iso-13:0 acids. The wax ester fatty alcohols and the alkoxy chains of the glyceryl ethers were mostly the C14-C20 chain lengths commonly observed in marine organisms. The distinctive medium chain neutral lipids in the jaw and melon fats of this whale may be related to the postulated acoustical role of these tissues in echolocation.

Adipose Tissue↗

Bonitasaura salgadoi gen. et sp. nov.: a beaked sauropod from the Late Cretaceous of Patagonia.

Ornithischian and theropod dinosaurs were morphologically diverse during the Cretaceous. In contrast, sauropods were relatively more conservative. The anatomy of Bonitasaura salgadoi, a new 9-m titanosaurian sauropod from Upper Cretaceous beds of Patagonia, suggests that sauropod anatomical diversity would have included unexpected items. Its unusual, rectangular lower jaw possesses narrow, anteriorly restricted teeth and shows evidence of a sharp keratinous sheath over the nondentigerous region that probably worked to guillotine plant material. This discovery definitely demonstrates that titanosaurs acquired a mandibular configuration similar to that of some basal diplodocoids, as had already been suggested by the lower jaw of the controversial genus Antarctosaurus. This oral configuration, plus the beak-like structure and the skull shape, resemble some traits more commonly seen in Laurasian ornithischians, mostly unexpressed in southern continents. A high sauropod morphological diversity seems to be in agreement with the poorly represented ornithischian clades of the southern hemisphere.

Animals↗

[Australian short-beaked echidna].

The Australian short-beaked echidna, a monotreme, is one of the oldest living mammals on earth. It is recorded to be the most widely distributed native mammal on the island continent and classed as 'common'. Yet, little is known about its natural history and biology in the wild. What science has learned about the echidna in the past 200 years and why there are still large gaps is reported here.

Animals↗

Evolution of the major histocompatibility complex: Isolation of class II beta cDNAs from two monotremes, the platypus and the short-beaked echidna.

Extant mammals are composed of three lineages: the eutherians, the marsupials and the monotremes. The majority of the mammalian major histocompatibility complex (MHC) data is based on the eutherian mammals, which generally have three classical MHC class II beta chain gene clusters - DRB, DQB and DPB, as well as the non-classical DMB and DOB. Marsupial DMB, DAB and DBB have been characterised. Confusion still surrounds the relationship of the marsupial DAB and DBB genes with the classical eutherian class II clusters. Here we present the first monotreme MHC class II beta chain sequences. Four MHC class II beta chain sequences were isolated from a spleen cDNA library from the short-beaked echidna, and one from a spleen cDNA library from platypus using a brushtail possum DAB probe. Given the non-orthologous relationship of the monotreme sequences with marsupial and eutherian beta chain clusters, we recommend that the five new monotreme sequences be assigned the nomenclature 'DZB', signifying the description of a new mammalian beta chain cluster. Our analysis suggests that all mammalian beta chain sequences (except DMB) evolved from a common ancestor. Maximum likelihood analysis places the monotreme beta chain sequences at the base of the mammalian clade, indicating their ancestral status. However, within the mammalian clade, monophyletic clades are not robust, and elucidation of the order of gene duplication that gave rise to the present-day gene clusters is not yet possible.

Animals↗

Analysis of the beak and feather disease viral genome indicates the existence of several genotypes which have a complex psittacine host specificity.

A study was made of the phylogenetic relationships between fifteen complete nucleotide sequences as well as 43 nucleotide sequences of the putative coat protein gene of different strains belonging to the virus species Beak and feather disease virus obtained from 39 individuals of 16 psittacine species. The species included among others, cockatoos ( Cacatuini), African grey parrots ( Psittacus erithacus) and peach-faced lovebirds ( Agapornis roseicollis), which were infected at different geographical locations, within and outside Australia, the native origin of the virus. The derived amino acid sequences of the putative coat protein were highly diverse, with differences between some strains amounting to 50 of the 250 amino acids. Phylogenetic analysis demonstrated that the putative coat gene sequences form six clusters which show a varying degree of psittacine species specificity. Most, but not all strains infecting African grey parrots formed a single cluster as did the strains infecting the cockatoos. Strains infecting the lovebirds clustered with those infecting such Australasian species as Eclectus roratus, Psittacula kramerii and Psephotus haematogaster. Although individual birds included in this study were, where studied, often infected by closely related strains, infection by highly diverged trains was also detected. The possible relationship between BFD viral strains and clinical disease signs is discussed.

Animals↗

Genetic diversity of the Rep gene of beak and feather disease virus in South Africa.

A study on the genetic variation of Beak and feather disease virus (BFDV) isolates in South Africa was performed by amplifying and sequencing a region within the ORF1 of the genome. Six different BFDV isolates were found in 15 psittacine species from 6 regions within South Africa, representing three unique isolates and three isolates that clustered into a budgerigar lineage (BG) previously described.

Animals↗

Complete amino acid sequence of the major component myoglobin from Hubb's beaked whale, Mesoplodon carlhubbsi.

The complete primary structure of the major component myoglobin from Hubb's beaked whale, Mesoplodon carlhubbsi, was determined by specific cleavage of the protein to obtain large peptides which are readily degraded by the automatic sequencer. In all experiments a Beckman 890C automatic sequencer was used to degrade the peptides. A cyanogen bromide digest was used to fragment the protein at its two methionine residues into three fragments which were separated by gel filtration. In a similar pattern the protein was citraconylated to protect the lysine residues and the modified protein fragmented at its arginine residues with trypsin. The three peptides obtained here were also purified by gel filtration. Sequencer analysis of the whole apoprotein, cyanogen bromide fragments and the peptides cleaved at the arginine residues with trypsin provided 80% of the completed sequence. The remainder of the sequence was obtained by digesting the middle cyanogen bromide fragment with staphylococcal protease and by total tryptic digestion of the whole apoprotein and isolating the resulting peptides by ion-exchange chromatography. The primary structure of the Mesoplodon carlhubbsi myoglobin represents a sequence which may be closey related to the ancestral sequence of all cetacean myoglobins.

Amino Acid Sequence↗

Plasma cofactors necessary for Enhydrina schistosa (beaked sea snake) venom to induce platelet aggregation.

A study of the effect of the venom of the beaked sea snake (Enhydrina schistosa) was undertaken on platelet aggregation. It was found that platelet aggregation and the release reaction occurred in the presence of both venom and plasma but, not with the venom alone. No effect was observed with fixed platelets distinguishing the effect of the venom from that of platelet aggregation with ristocetin or botrocetin and indicating metabolic dependence. Studies to elucidate the plasma factor required for platelet aggregation under the release reaction indicated dependence on the presence of both Factor II and calcium ions. This venom may prove to be a useful laboratory reagent in coagulation studies because of the Factor II and calcium dependence.

Animals↗

Blue-green color and composition of Stejneger's beaked whale (Mesoplodon stejnegeri) milk.

Two hundred ml of milk were obtained from a lactating Stejneger's beaked whale stranded at Ninilchik, Alaska on 21 Oct, 1980. Total solids (41%) were similar to values reported for sperm and belukha whales, while fat (17%) was half as great and crude protein (17%) was 2-4 times greater than in milk of these species. Lactose was not detected. Calcium (0.22%) was greater than reported for pigmy sperm whales but less than for blue whales. Phosphorus (0.07%) was less than for any of the above species. Sodium and potassium concentrations were 0.13% and 0.11%, respectively. Values (microgram/g) for other elements analyzed (magnesium, 42; iron, 35; copper, 2.6; zinc, 1.5; manganese, 0.3; selenium, 0.36) have not been reported for whale milk. Based on SDS-gel electropherograms, this whale milk did not contain a whey protein corresponding to cattle milk alpha-lactalbumin. A blue-green pigment in the milk was identified as biliverdin.

Animals↗

Cyto- and chemoarchitecture of the amygdala of a monotreme, Tachyglossus aculeatus (the short-beaked echidna).

We have examined the cyto- and chemoarchitecture of the temporal and extended amygdala in the brain of a monotreme (the short-beaked echidna Tachyglossus aculeatus) using Nissl and myelin staining, enzyme histochemistry for acetylcholine esterase and NADPH diaphorase, immunohistochemistry for calcium binding proteins (parvalbumin, calbindin and calretinin) and tyrosine hydroxylase. While the broad subdivisions of the eutherian temporal amygdala were present in the echidna brain, there were some noticeable differences. No immunoreactivity for parvalbumin or calretinin for somata was found in the temporal amygdala of the echidna. The nucleus of the lateral olfactory tract could not be definitively identified and the medial nucleus of amygdala appeared to be very small in the echidna. Calbindin immunoreactive neurons were most frequently found in the ventrolateral part of the lateral nucleus, intraamygdaloid parts of the bed nucleus of the stria terminalis and the lateral part of the central nucleus. Neurons strongly reactive for NADPH diaphorase with filling of the dendritic tree were found mainly scattered through the cortical, central and lateral subnuclei, while neurons showing only somata reactivity for NADPH diaphorase were concentrated in the basomedial and basolateral subnuclei. Most of the components of the extended amygdala of eutherians could also be identified in the echidna. Volumetric analysis indicated that the temporal amygdala in both the platypus and echidna is small compared to the same structure in both insectivores and primates, with the central and medial components of the temporal amygdala being particularly small.

Acetylcholinesterase↗

Cyto- and chemoarchitecture of the dorsal thalamus of the monotreme Tachyglossus aculeatus, the short beaked echidna.

We have examined the cyto- and chemoarchitecture of the dorsal thalamus of the short beaked echidna (Tachyglossus aculeatus), using Nissl and myelin staining, immunoreactivity for parvalbumin, calbindin, calretinin and non-phosphorylated neurofilament protein (SMI-32 antibody), and histochemistry for acetylcholinesterase and NADPH diaphorase. Immunohistochemical methods revealed many nuclear boundaries, which were difficult to discern with Nissl staining. Parvalbumin immunoreactive somata were concentrated in the ventral posterior, reticular, posterior, lateral and medial geniculate nuclei, while parvalbumin immunoreactivity of the neuropil was present throughout all but the midline nuclei. Large numbers of calbindin immunoreactive somata were also found within the midline thalamic nuclei, and thalamic sensory relay nuclei. Immunoreactivity for calretinin was found in many small somata within the lateral geniculate "a" nucleus, with other labelled somata found in the lateral geniculate "b" nucleus, ventral posterior medial and ventral posterior lateral nuclei. Immunoreactivity with the SMI-32 antibody was largely confined to somata and neuropil within the thalamocortical relay nuclei (ventral posterior medial and lateral nuclei, lateral and medial geniculate nuclei and the posterior thalamic nucleus). In broad terms there were many similarities between the thalamus of this monotreme and that of eutheria (e.g. disposition of somatosensory thalamus, complementarity of parvalbumin and calbindin immunoreactive structures), but there were some unique features of the thalamus of the echidna. These include the relatively small size of the thalamic reticular nucleus and the preponderance of calbindin immunoreactive neurons over parvalbumin immunoreactive neurons in the ventral posterior nucleus.

Acetylcholinesterase↗

Baculovirus expression of beak and feather disease virus (BFDV) capsid protein capable of self-assembly and haemagglutination.

Beak and feather disease virus (BFDV) is a common avian circovirus infection of wild Psittaciformes and is a recognised threat to endangered psittacine species. Currently, there is a requirement to develop BFDV antigen for diagnostic purposes and since efforts to propagate BFDV in vitro have so far been unsuccessful the entire coding region of BFDV ORF C1 was expressed in Sf9 insect cells using a baculovirus expression system. The entire coding region of BFDV ORF C1, the presumptive capsid, was expressed in Sf9 insect cells using baculovirus expression system. Electron microscopic examination of negatively stained material demonstrated that the recombinant protein self-assembled to produce virus-like particles (VLPs) thus confirming that ORF C1 is likely to be the sole determinant for capsid construction in vivo. BFDV VLPs also possessed haemagglutinating activity which provides further evidence that self-assembled BFDV VLPs retain receptor mediated biological activity and that the determinants for BFDV haemagglutination activity rely solely on the capsid protein. The recombinant protein reacted with anti-BFDV sera from naturally immune parrots and cockatoo and from chickens experimentally inoculated with native BFDV in both Western blots and haemagglutination inhibition (HI) assay. BFDV VLPs were also a suitable replacement antigen for serological detection of BFDV antibody by HI.

Animals↗

Isolation and characterization of rufoxin, a novel protein exhibiting neurotoxicity from venom of the psammophiine, Rhamphiophis oxyrhynchus (Rufous beaked snake).

Colubrid snake venoms potentially represent a vast source of novel biological actives and structural motifs owing to their diverse phylogeny. The present study describes the identification of rufoxin, a neurotoxin from the venom of Rhamphiophis oxyrhynchus (Rufous beaked snake) which is a member of the African colubrid lineage, the psammophiines. Rufoxin (1 microM) displayed reversible post-synaptic neurotoxic activity as evidenced by significant inhibition of indirect twitches and responses to exogenous nicotinic agonists in the chick biventer cervicis nerve-muscle preparation. Rufoxin (0.1-1.0 microM) also caused a rightward parallel shift of cumulative concentration-response curves to carbachol (CCh; 0.6-80 microM) without a significant depression of the maximum response, suggestive of classical competitive antagonism at the skeletal muscle nicotinic receptor. Rufoxin lacks NH(2)-terminal sequence homology to previously identified snake venom toxins. This work indicates a wider distribution of neurotoxins across the advanced snake superfamily than previously described.

Analysis of Variance↗