Porcupine Quills Research Articles

Penetration of the small intestine by an unusual foreign body resulting in colic in a horse: A case report

Summary A nine-year-old Arabian gelding was evaluated for acute abdominal pain. Based on clinical signs and the results of the diagnostic work-up, surgical exploration of the abdominal cavity was performed. An adhesion was found involving a section of jejunum, its mesentery, and the omentum. Passage of gas and/or ingesta was obstructed at that point. On closer examination of the involved bowel, a porcupine quill which had perforated throught the intestinal wall from the lumen was identified. This was believed to have been the inciting cause for the formation of the adhesion and subsequent intestinal obstruction.

Recognition of Factitial Hand Injuries

Facitial injuries with various presentations occur with some frequency to the hand because it is a body part that is easily accessible. Methods used to produce wounds included insertion of porcupine quills, application of constrictive rubber bands, mascara injections and excoriation of healing wounds. It is important to recognize the factitial origin in order to avoid needless repetitive surgery and permanent hand disability. No specific pattern of psychopathology was found in our cases. The patients' attitude toward their lesions was one of bland unconcern and stoicism. The patients were resistant to psychiatric referral and persisted in seeking medical responsibility for cure. Successful management requires early suspicion and prompt recognition as well as establishment of non-accusatory relationship with the primary physician. Confrontation should be avoided if possible. Even if reinforced with collaborative evidence, such confrontation will have limited effect on the patient's subsequent behavior.

Macromolecular structure and organization of alpha keratin.

AbstractThe small‐angle equatorial X‐ray scattering of alpha keratin (African porcupine quill) was studied using a direct type of analysis, which allows the separation of the intermicro‐fibrillar interference effects from those of the intramicrofibrillar scattering without the use of prior assumptions. X‐ray data were obtained from 470–21 Å; their analysis by the above method resulted in a z‐axis projection of the microfibrillar electron density, which extends over a diameter of 80 Å and has a core region surrounded by a peak located at a radius of 28 Å. The macromolecular organization of the 80‐Å‐diameter microfibrils was found to be an arc‐like layer type of aggregation and not a pseudohexagonal packing. When the specimen was subjected to silver staining the aggregation of the microfibrils did not change except for a slight contraction. The z‐axis projection of the stained microfibril, however, was significantly different. The silver appears to build up slightly around the outer periphery of the microfibril, stains the peripheral region very little, deposits on the inside of the peripheral region, and outlines the core area.

Tyrosine-rich proteins in keratins

1. 1. In addition to high-sulphur and low-sulphur proteins a third class of proteins rich in tyrosine and glycine occurs in mammalian hard keratins and is particularly abundant in porcupine quill and echidna quill. 2. 2. A comparison of the contents of high-sulphur, low-sulphur and high-tyrosine proteins in various keratins taken in conjunction with parallel X-ray diffraction studies suggests that the high-tyrosine proteins occur in the matrix rather than in the microfibrils.

Demonstration of rotational symmetries in alpha-keratin microfibrils of porcupine quill tip

Selected electron micrographs of transversely, obliquely and longitudinally sectioned microfibrils of transversely sectioned porcupine quill tip are shown to possess 2-fold radial, 3-fold radial and 5-fold polygonal rotational symmetries. These symmetries are verified with a rotation technique, and are similar to edge, corner and face projections of a pentagonal dodecahedron. The a-keratin microfibril is therefore suggested to be composed of a linear arrangement of morphologically identical microfibrillar subunits which approximate the shape of a pentagonal dodecahedron. The various line patterns present in electron micrographs of microfibrils are explained by different orientations of this three-dimensional shape within the thickness of the section. Previous electron microscopic models for the structure of the microfibrils are incompatible with these results. The image averaging methods used to arrive at these earlier models are discussed, and are thought to yield results which must differ from the demonstrated rotational symmetries.

The effects of prednisone, chlorambucil, and methotrexate in sarcoidosis

Thin-walled, cylindrical structures are found extensively in both engineering components and in nature. The weight to load bearing ratio is a critical element of design of such structures in a variety of engineering applications, including space shuttle fuel tanks, aircraft fuselages, and offshore oil platforms. In nature, thin-walled cylindrical structures are often supported by a honeycomb- or foam-like cellular core, as for example, in plant stems, porcupine quills, or hedgehog spines. Previous studies have suggested that a compliant core increases the buckling resistance of a cylindrical shell over that of a hollow cylinder of the same weight. In this paper, we extend the linear-elastic buckling theory by coupling it with basic plasticity theory to provide a more comprehensive analysis of isotropic, cylindrical shells with compliant cores. We examine the optimal design of a thin-walled cylinder with a compliant core, of given radius and specified materials, for a prescribed load bearing capacity in axial compression. The analysis gives the values of the shell thickness, the core thickness, and the core density that maximize the load bearing capacity of the shell with a compliant core over an equivalent weight hollow shell. The analysis also identifies the optimum ratio of the core modulus to the shell modulus and is supported by a Lagrangian optimization technique. The analysis further discusses the selection of materials in the design of a cylinder with a compliant core, identifying the most suitable material combinations. The performance of a cylinder with a compliant core is compared with competing designs (optimized hat-stiffened shell and optimized sandwich-wall shell). Finally, the challenges associated with achieving the optimal design in practice are discussed, and the potential for practical implementation is explored.

Letters to the Editor

I appreciate and am in full agreement with Dr. Carithers remarks with two exceptions. In a recent review, W. J. Warwick points out that the scratch should be emphasized more than the cat in this syndrome. Reports have indicated that splinters of wood, pins, fish hooks, rabbit claws, thorns, and porcupine quills have acted as inoculating instruments. Therefore, the monkey or dog scratch may well be added to this list. As Dr. Carithers emphasized, it is most important that the physician look for the inoculation site and inquire about a primary lesion that may have healed during the 3 or 4 weeks prior to onset of lymphadenopathy.

Keratin Fibres II. Separation and Analysis of Medullary Cells

A mild method is described for the separation of the medullae of keratin fibres. The method consists of staining with gold, which is deposited preferentially in the medulla. The fibre is then disrupted by agitation in formic acid and the heavy medullary cells separated by density.gradient centrifugation. By means of model experiments on whole fibres and medulla produced by dissection of porcupine quills, it is concluded that (except for some oxidation of cystine to cysteic acid) a negligible amount of modification of the medulla results from the separation procedure.

Structure of α-Keratin

IN a recent publication, Fraser, MacRae and Miller1 have given a comprehensive interpretation of the X-ray diffraction photograph of α-keratin (porcupine quill tip) and, in particular, considered the quantitative aspects of the small-angle and large-angle equatorial scatter. This problem has also been discussed by Wilson2, whose approach differs in some important respects from that of Fraser et al., although based on a microfibril model of the same type. Wilson supposes that interference effects between protofibrils within a microfibril, as well as between different microfibrils, affect the X-ray intensity at small scattering angles, whereas Fraser et al. consider only the ‘between microfibril’ interference. According to them, the small-angle scatter can be ascribed solely to a difference in effective mean electron density between the microfibrils and their surrounding matrix, and for a given microfibril-matrix texture the intensity should be simply proportional to this difference. The evidence in favour of this idea is that when heavy metals, such as silver or osmium, are incorporated in the matrix material the main effect on the diffraction is to enhance the small-angle scatter, leaving the maxima of intensity at the same scattering angles as before.

X-ray diffraction patterns of α-fibrous proteins

A method is described which enables allowance to be made for the effect of surrounding material on the Fourier transform of a coiled coil. Using this method, distributions of intensity on the equator and near-equatorial layer lines are calculated for the wet and dry states, and compared with the observed distributions in oyster muscle, porcupine quill, rabbit psoas muscle and tropomyosin.

The coiled-coil model of α-keratin structure

Quantitative measurements of the X-ray diffraction pattern of dry porcupine quill tip are reported for both low- and high-angle regions. There is a considerable measure of agreement with the intensity transform calculated for the coiled-coil rope model proposed by Crick but precise comparison is handicapped by interference effects due to macromolecular organization. A method of allowing for these effects is devised for the equator and good agreement obtained with the observed pattern.

The structure of α-keratin

A model for the structural arrangements of the protein chains in α-keratin has been proposed on the basis of the diffraction pattern of porcupine quill tips. The model implies that the protein chains are basically of the α-helix configuration but are supercoiled and packed in five concentric layers. The supercoiling in the different layers makes one turn in 198 Å along the axis of the tonofilament. The number of chains in the different layers are 3, 7, 10, 16, and 19. This arrangement that is based on the diffraction pattern gives a diameter of the tonofilament that is in agreement with electron microscopic data.

Porcupine Quill Flatteners from Central United States

AbstractQuill flatteners from Wisconsin, Minnesota, North and South Dakota, Montana, and Wyoming, which are attributed to Menominee, Sioux, Arikara, Blackfeet, and Arapaho, are described in four groups. Iron, S-shaped flatteners date from the period of European contact and trade, and two types of antler and horn flatteners are believed to have been made during the same time period. The only prehistoric or archaeological specimens are in the fourth group of flatteners made of long, thin pieces of mammal bone with rounded ends.

Porcupine Quills in Viscera of Fisher

Porcupine Quills in Viscera of Fisher

Meridional Reflexions in the X-ray Diffraction Photographs of α-Keratin

X-RAY diffraction photographs of various keratins taken with fine-slit collimators of high resolution display a rich series of meridional reflexions1–3. Their spacings may conveniently be regarded as orders of a macro-period of 198 A. with very few exceptions. Astbury4 has used the spacings and intensities of reflexions reported by Bear and others, from porcupine quill tip, to derive a one-dimensional Patterson diagram, and to explore the possibility of finding the sequence of amino-acid residues in the protein chains of the crystalline portion of the keratin. It might well be that the differences among keratins could provide useful clues in this quest, and the present intention is to direct attention to them.

Perforation of the gastrointestinal tract by an unusual foreign body; a porcupine quill; report of two cases.

SHARP, indigestible foreign bodies are not infrequently swallowed, and yet consequent perforation of the gastrointestinal tract is rare.1 Macmanus2 analyzed 95 cases of perforation by sharp objects of great variety. He found that 73 per cent of perforations occurred in and around the ileocecal region and that the clinical features of perforation are most frequently manifest in four ways: an early localized peritonitis; an indurated, inflammatory tumor; an abscess; and general peritonitis. Snodgrass3 has emphasized the frequency with which a person is exposed to the hazards of a toothpick, particularly one using artificial dentures, which cover ordinarily protective sensory areas. . . .

Molecular Organization in Keratins

A series of density determinations on physically and chemically modified wools shows that extensions up to 70% and supercontraction of 15% in steam are not accom panied by density changes. In contrast, residues from chemical extractions and en zymatic digestions show significant increases. Cortical cells fractionated from trypsin digests by gradient column techniques have densities comparable to that of porcupine quill tips. The extent to which these measurements may be correlated with crystallinity is discussed.

How to Remove Porcupine Quills

How to Remove Porcupine Quills

An X-ray study of α-keratin. II. Diffractometer measurements of the complete diffraction pattern of Canadian porcupine quill

An X-ray study of α-keratin. II. Diffractometer measurements of the complete diffraction pattern of Canadian porcupine quill

Effects of Porcupine Quills in Humans

Previous articleNext article No AccessLetters to the EditorsEffects of Porcupine Quills in HumansAlbert R. ShadleAlbert R. Shadle Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by The American Naturalist Volume 89, Number 844Jan. - Feb., 1955 Published for The American Society of Naturalists Article DOIhttps://doi.org/10.1086/281861 Views: 10Total views on this site Citations: 1Citations are reported from Crossref PDF download Crossref reports the following articles citing this article:Uldis Roze, David C. Locke, Nick Vatakis Antibiotic properties of porcupine quills, Journal of Chemical Ecology 16, no.33 (Mar 1990): 725–734.https://doi.org/10.1007/BF01016483