bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of external root resorption during orthodontic treatment in root filled teeth compared with their contralateral teeth with vital pulps
Authors: Llamas‐Carreras J. M. , Amarilla A. , Solano E. , Velasco‐Ortega E. , Rodríguez‐Varo L. , Segura‐Egea J. J.
Published: April 2010

Llamas‐Carreras JM, Amarilla A, Solano E, Velasco‐Ortega E, Rodríguez‐Varo L, Segura‐Egea JJ.Study of external root resorption during orthodontic treatment in root filled teeth compared with their contralateral teeth with vital pulps.International Endodontic Journal.

Aim To determine whether root filled teeth and those with vital pulps exhibit a similar degree of external root resorption (ERR) as a consequence of orthodontic treatment.

Methodology The study sample consisted of 77 patients, with a mean age of 32.7 ± 10.7 years, who had one root filled tooth before completion of multiband/bracket orthodontic therapy for at least 1 year. For each patient, digital panoramic radiographs taken before and after orthodontic treatment were used to determine the proportion of external root resorption (PRR), defined as the ratio between the root resorption in the root filled tooth and that in its contralateral tooth with a vital pulp. The student’st‐test,anovaand logistic regression analysis were used to determine statistical significance.

Results The mean PRR was 1.00 ± 0.13, indicating that, in the total sample, there were no significant differences in root resorption in the root filled teeth and their contralateral teeth with vital pulps. Multivariate logistic regression analysis suggested that PRR was significantly greater in incisors (P = 0.0014; odds ratio = 6.2885, C.I. 95% = 2.0–19.4), compared to other teeth, and in women (P = 0.0255; odds ratio = 4.2, C.I. 95% = 1.2–14.6), compared to men.

Conclusions There was no significant difference in the amount or severity of external root resorption during orthodontic movement between root filled teeth and their contralateral teeth with vital pulps.
Divergence from the growth–survival trade‐off and extreme high growth rates drive patterns of exotic tree invasions in closed‐canopy forests
Authors: Martin Patrick H. , Canham Charles D. , Kobe Richard K.
Published: April 2010

1. The study of invasiveness typically emphasizes early successional life‐history traits in exotic plants, which enable the capture of high resources in disturbed environments and rapid growth. A key issue in invasion dynamics is whether such behaviours come at the expense of traits such as low‐light survivorship, which allow species to become more dominant later in succession.

2. We used maximum‐likelihood analysis to compare the growth and survivorship of two exotic trees, Ailanthus altissima and Acer platanoides, with nine dominant native tree species in closed‐canopy forests in Connecticut, USA. Growth was modelled as a function of light and survivorship as a function of recent growth; combining models yielded estimates of light‐dependent mortality.

3. The exotic species had strikingly high growth rates, exceeding all native species at light levels ≥ 10% full sun, and growing 2.6 times faster than the fastest‐growing native species at 80% full sun. At low‐light levels (< 3% full sun), however, growth rates of five native species exceeded both exotics. Exotic species survivorship (as a function of light‐driven growth) was strongly dependent on the degree of shading: at 1% full sun, the annual mortality rate of A. platanoides was 10% and A. altissima was 17%; only two native species had higher mortalities. However, at 5% full sun, A. platanoides’ mortality was < 1%, superior to all but three native species. Mortality of all species dropped to < 1% by 10% full sun, except A. altissima whose mortality remained high at c. 10%.

4. A life‐history trade‐off analysis (based on radial growth, height allometry and low‐light survivorship) shows a nearly linear trade‐off for most species. The native species and Ailanthus follow the common life‐history trade‐off of low‐light survivorship vs. high‐light growth. However, A. platanoides diverges from this trade‐off pattern by combining very high growth rates with moderately high shade tolerance.

5. Simulations with SORTIE‐ND (a forest dynamics model) indicate that poor survivorship of A. altissima will limit it to disturbed sites, whereas A. platanoides’ unusual combination of traits makes it invasive in both disturbed and undisturbed forests. Overall, native shade‐tolerant trees and slow stand dynamics make undisturbed forests highly resistant to invasion by exotic trees that are intolerant of shade.

6. Synthesis. This study showcases the importance of rapid growth in invasive plants, holding even for exotic tree species known to invade established forests. For A. altissima, high growth rates were accompanied by poor low‐light survivorship. A. platanoides departs from the general trade‐off pattern that exists among native species and A. altissima, and consequently it can be highly invasive in closed‐canopy forests.
Career stage and work setting create different barriers for evidence‐based medicine
Authors: Swennen Maartje H.J. , van der Heijden Geert J.M.G. , Blijham Geert H. , Kalkman Cor J.
Published: April 2010

Rationale, aims and objectives  Although many barriers to practising evidence‐based medicine (EBM) are described, it remains poorly understood why clinicians do, and do not, incorporate high‐quality evidence into their routine practice. To date, a comprehensive framework for the classification for barriers to practising EBM is lacking. This qualitative study explored the relationship between differences in career stage and work setting among doctors and their perceived barriers for practising EBM. We also explored an alternative classification of barriers.

Methods  Purposive participant sampling reflected three career stages in two different work settings: four registrars, four consultant anaesthetists and four senior anaesthetists from two departments of anaesthesiology, in an academic and a general hospital, in The Netherlands. Perceptions on practising EBM and its barriers were explored in semi‐structured interviews. Using grounded theory approach, we build a framework for the classification of these barriers.

Results  In both departments, registrars and consultants demonstrated little sense of urgency to work on their EBM performance; registrars struggled with information overload and hierarchical dependence, and consultants practised confidence‐based medicine. Senior doctors in both departments reported that combining clinical work with leadership tasks made them more reflective, and therefore more susceptible to the reasoning approach inherent within the current approach to EBM. They considered themselves willing and able to apply EBM, and were reported to act accordingly. Differences in setting that complicated practising EBM related to the general hospital. The absence of formal hierarchy among doctors resulted in a lack of medical consensus and an absence of integrated management teams hindered collaboration between doctors and non‐medical managers. We identified 10 conditions that were conducive to the practice of EBM.

Conclusions  Both career stage and work setting were associated with perceived barriers to practising EBM. We have included these in our theoretical framework for classification of these barriers.
Contrasting dynamics of water and mineral nutrients in stems shown by stable isotope tracers and cryo‐SIMS
Authors: METZNER RALF , THORPE MICHAEL R. , BREUER UWE , BLÜMLER PETER , SCHURR ULRICH , SCHNEIDER HEIKE U. , SCHROEDER WALTER H.
Published: April 2010

Lateral exchange of water and nutrients between xylem and surrounding tissues helps to de‐couple uptake from utilization in all parts of a plant. We studied the dynamics of these exchanges, using stable isotope tracers for water (H218O), magnesium (26Mg), potassium (41K) and calcium (44Ca) delivered via a cut stem for various periods to the transpiration stream of bean shoots (Phaseolus vulgaris cv. Fardenlosa Shiny). Tracers were subsequently mapped in stem cross‐sections with cryo‐secondary ion mass spectrometry.

The water tracer equilibrated within minutes across the entire cross‐section. In contrast, the nutrient tracers showed a very heterogeneous exchange between xylem vessels and the different stem tissues, even after 4 h. Dynamics of nutrients in the tissues revealed a fast and extensive exchange of nutrients in the xylem parenchyma, with, for example, calcium being completely replaced by tracer in less than 5 min. Dilution of potassium tracer during its 30 s transit in xylem sap through the stem showed that potassium concentration was up‐regulated over many hours, to the extent that some of it was probably supplied by phloem recirculation from the shoot.
Angiogenesis and lymphangiogenesis in bronchial asthma
Authors: Detoraki A. , Granata F. , Staibano S. , Rossi F. W. , Marone G. , Genovese A.
Published: April 2010

To cite this article: Detoraki A, Granata F, Staibano S, Rossi FW, Marone G, Genovese A. Angiogenesis and lymphangiogenesis in bronchial asthma. Allergy 2010; 65: 946–958.

Neovascularization plays a prominent role in inflammation and tissue remodeling in several chronic inflammatory disorders. Vessel number and size, vascular surface area and vascular leakage are all increased in biopsies from patients with asthma. High levels of VEGF and other angiogenic factors have been detected in tissues and biological samples of patients with asthma and correlate with disease activity and inversely with airway hyper‐responsiveness. Inflammation in the lung stimulates the growth of new blood vessels and these contribute to the airway obstruction or airway hyper‐responsiveness, or both. Effector cells of inflammation (human lung mast cells, basophils, eosinophils, macrophages, etc.) are major sources of a vast array of angiogenic and lymphangiogenic factors. Inhaled corticosteroids reduce vascularity and growth factor expression and might modulate bronchial vascular remodeling in asthma. Specific antagonists to VEGF and other angiogenic factors and their receptors might help to control chronic airway inflammation and vascular remodeling and offer a novel approach for the treatment of chronic inflammatory lung disorders.
Abdominal ultrasonography as a new modality for the diagnosis of gastroesophageal reflux disease
Authors: Tomita Toshihiko , Iijima Hiroko , Kim Yongmin , Oshima Tadayuki , Hori Kazutoshi , Nishiguchi Shuhei , Matsumoto Takayuki , Miwa Hiroto
Published: April 2010

Background and Aims:  Thickening and abnormal architecture of the esophageal wall in gastroesophageal reflux disease (GERD) have been reported using endoscopic ultrasonography (US), but whether extracorporeal abdominal US is a useful diagnostic modality has not been investigated.

Methods:  Subjects were 37 GERD, 24 non‐erosive reflux disease (NERD) patients and 32 controls who visited our hospital from 2006–2009 and underwent upper gastrointestinal endoscopy and extracorporeal abdominal US. The US operator was unaware of any clinical information and examined the following: (i) thickness (≥5 mm) and (ii) architecture of the esophageal wall; and (iii) presence of reflux. GERD was diagnosed when two or more of these items were positive.

Results:  Thickening of the lower esophageal wall in erosive GERD, NERD and controls was 5.7 ± 0.6, 4.4 ± 0.8 and 4.7 ± 0.9 mm, respectively. The thickness in erosive GERD was significantly greater (P < 0.05) than that in NERD patients and controls. Sensitivity, specificity and accuracy of abdominal US diagnosis for erosive GERD and NERD (vs control) was 84.6% (11/13), 25% (6/24), 91.1% (31/34) and 91.1% (31/34), 89.4% (42/47) and 63.8% (37/58), respectively.

Conclusion:  Extracorporeal abdominal US could be a new useful modality for diagnosing GERD.
Sofalcone, a gastroprotective drug, promotes gastric ulcer healing following eradication therapy for Helicobacter pylori: A randomized controlled comparative trial with cimetidine, an H2‐receptor antagonist
Authors: Higuchi Kazuhide , Watanabe Toshio , Tanigawa Tetsuya , Tominaga Kazunari , Fujiwara Yasuhiro , Arakawa Tetsuo
Published: April 2010

Background and Aims:  According to reports in Japanese patients, 1 week of Helicobacter pylori eradication therapy alone is not adequate for healing of gastric ulcers; 7–8 weeks of anti‐ulcer therapy are subsequently required. We compared a gastroprotective drug, sofalcone, and an H2‐receptor antagonist, cimetidine, in terms of promoting ulcer healing after 7 weeks of administration following 1 week of eradication therapy.

Methods:  Eradication therapy was administered to 64 patients with H. pylori‐positive active gastric ulcer at least 10 mm in diameter, after which 32 patients each received 7 weeks of ulcer treatment with sofalcone (300 mg/day) or cimetidine (800 mg/day).

Results:  The H. pylori eradication rate was 81.3% (intention‐to‐treat: ITT) and 81.3% (per protocol: PP) in the sofalcone group, and 62.5% (ITT) and 64.5% (PP) in the cimetidine group. The ulcer healing rate after 8 weeks was 71.9% (ITT) and 71.9% (PP) in the sofalcone group, and 71.9% (ITT) and 71.0% (PP) in the cimetidine group. The rate of a flat pattern of scarred mucosa was 43.5% (ITT) and 43.5% (PP) in the sofalcone group, and 47.8% (ITT) and 50.0% (PP) in the cimetidine group. No significant differences were seen between the two groups in terms of H. pylori eradication rate, ulcer healing rate and flat pattern rate.

Conclusion:  Sofalcone promoted gastric ulcer healing during 7 weeks of treatment following 1 week of eradication therapy, and the healing rate was equivalent to that of cimetidine. Symptom disappearance rates were significantly better in the sofalcone group than in the cimetidine group. This may be a useful way of using a gastroprotective drug in the H. pylori era.
Lung metastasectomy in colorectal cancer: Is this surgery effective in prolonging life?
Authors: PRIMROSE John , TREASURE Tom , FIORENTINO Francesca
Published: April 2010

The commonest context in which pulmonary metastasectomy is performed is for recurrent colorectal cancer. With a more active policy of surveillance among cancer teams, ready access to ever faster CT scans and a willingness to perform further surgery to control recurrent cancer, the practice of pulmonary metastasectomy is increasing. In this pro/con debate the issues are explored. It is recognized by both sides that there is no randomized trial evidence on which to base the practice. The difference of opinion is whether there is sufficient evidence from very many case series of both pulmonary and hepatic metastasectomy on which to base current practice. The surgeon's view is that the weight of evidence from many follow‐up studies is in favour of continuing this practice. The mathematician's view is that case selection could account for nearly all the observed results.
NMDA receptor antagonism in the basolateral but not central amygdala blocks the extinction of Pavlovian fear conditioning in rats
Authors: Zimmerman Joshua M. , Maren Stephen
Published: April 2010

Glutamate receptors in the basolateral complex of the amygdala (BLA) are essential for the acquisition, expression and extinction of Pavlovian fear conditioning in rats. Recent work has revealed that glutamate receptors in the central nucleus of the amygdala (CEA) are also involved in the acquisition of conditional fear, but it is not known whether they play a role in fear extinction. Here we examine this issue by infusing glutamate receptor antagonists into the BLA or CEA prior to the extinction of fear to an auditory conditioned stimulus (CS) in rats. Infusion of the α‐amino‐3‐hydroxyl‐5‐methyl‐4‐isoxazole‐propionate (AMPA) receptor antagonist, 2,3‐dihydroxy‐6‐nitro‐7‐sulfamoyl‐benzo[f]quinoxaline‐2,3‐dione (NBQX), into either the CEA or BLA impaired the expression of conditioned freezing to the auditory CS, but did not impair the formation of a long‐term extinction memory to that CS. In contrast, infusion of the N‐methyl‐d‐aspartate (NMDA) receptor antagonist, d,l‐2‐amino‐5‐phosphonopentanoic acid (APV), into the amygdala, spared the expression of fear to the CS during extinction training, but impaired the acquisition of a long‐term extinction memory. Importantly, only APV infusions into the BLA impaired extinction memory. These results reveal that AMPA and NMDA receptors within the amygdala make dissociable contributions to the expression and extinction of conditioned fear, respectively. Moreover, they indicate that NMDA receptor‐dependent processes involved in extinction learning are localized to the BLA. Together with previous work, these results reveal that NMDA receptors in the CEA have a selective role acquisition of fear memory.
THE ONTOGENETIC DEVELOPMENT OF THE SOMATIC MUSCULATURE OF THE TRUNK OF THE AGLOSSAL ANURAN XENOPUS LAEVIS (DAUDIN)
Authors: RYKE P. A. J.
Published: April 2010

The secondary somatic muscles of the trunk develop by means of proliferations from the primary muscles. The dorsal part of the “Urwirbelfortsatz” contains the elements of both the m. obliquus abdominis internus and m. obliquus abd. externus. The m. ileolumbalis of the adult is formed by the fusion of the m. ileolumbalis, pars medialis and pars lateralis. A separate m. coccygeo‐sacralis is present in the young post‐metamorphic stage. A true horizontal myoseptum is absent. A well‐developed m. rectus abdominis superficialis can be distinguished during metamorphosis and even in the young post‐metamorphic stage. The ontogenesis proves the allegedly primitive features concerning the m. rectus abdominis, the m. ileolumbalis and the m. coccygeo‐sacralis to be specializations. Xenopus must be regarded as a very specialized anuran.
The Development of The Chondrocranium of Heleophryne Purcelli Sclater with special Reference to the Palatoquadrate and the Sound‐conducting Apparatus
Authors: VAN DER WESTHUIZEN C. M.
Published: April 2010

Abstract A description of the later phases of the ontogeny of the chondrocranium of Heleophryne purcelli is given. Special attention has been given to the development of the sound‐conducting apparatus and to the structural changes of the palatoquadrate during metamorphosis. The operculum, the pars interna plectri and the pars media plectri are apparently of capsular origin, whereas the pars externa plectri and the anulus tympanicus, which develop from a common blasteme, appear to the be derivatives of the palatoquadrate. It is suggested that the infrapharyngohyal had been incorporated into the otic capsule during the phylogeny, and that it gives rise to the operculum and the pars interna et media plectri, as well as to the floor of the fossa fenestrae ovalis and the otic ledge of the adult. Similarly, the epihyal became incorporated into the posterior portion of the larval palatoquadrate (epimandibular), and gives rise to the pars externa plectri of the adult. The suprapharyngohyal is represented by the otic process and the lateral portion of the parotic crest. The anulus tympanicus is probably the homologue of the stylohyal of fishes. The suprapharyngomandibular and the infrapharyngo‐mandibular are both absent in the adult skull.
The Frog Tongue: II. Histogenesis of Fungiform Papillae in Rana catesbeiana
Authors: Hammerman David L.
Published: April 2010

The histogenesis of fungiform papillae has been studied in two premetamorphic, ten metamorphic and one adult stage of Rana catesbeiana.

The gustatory papillae anlagen consist of club‐shaped groups of cells and are first seen just prior to the onset of metamorphosis. The distal portion of the cell group forms the end‐disc or taste bud of the papilla, while the proximal portion of the cell group forms the epithelial walls of the papilla's stalk region. The papillary core is derived from the general corium of the tongue.

The end‐disc of a mature fungiform papilla possesses seven distinct forms of epithelial cells, viz.: goblet, rod, forked, fusiform, ciliated columnar, diagonal columnar and cuboidal cells. A nerve‐cushion is present beneath the end‐disc. It consists of a distal homogeneous zone and a basal fibrous portion. The papillary stalk consists of a single layer of unciliated cuboidal and diagonal columnar cells surrounding the papilla's core.

Developmental and histological differences are noted when comparing Rana catesbeiana with Rana sylvatica.
A Third Embryo of Myxine: Considerations on Hypophysial Ontogeny and Phylogeny
Authors: Fernholm Bo
Published: April 2010

A 4.5 cm Myxine embryo is described. The structure of its adenohypophysis suggests that it is derived from a dorsal thickening and proliferation of the nasopharyngcal duct epithelium as a homogeneous mass of cells. This process seems to start medially and proceed laterally. The characteristic lobulated appearance of the adult adenohypophysis is caused by a later invasion of connective tissue. Large areas of the ventral brain surface were found to be richly vascularized. No traces of an endostylar arrangement were observed and the thyroid follicles were distinct.
The Structure of the Mouthparts of Syrphid larvae (Diptera) in Relation to Feeding Habits
Authors: Roberts Michael J.
Published: April 2010

The anatomy of the head is described for three species of syrphid larvae of differing feeding habits and the relation of the structure to the function is shown.

The degree of adaptation of both the musculature and the skeletal parts of the cephalopharynx to the type of food which the larva partakes is discussed. The mouthparts are discussed in detail and the probable course by which the complex mandibular lobes of aquatic, filter‐feeding syrphid larvae were evolved, is pointed out.
Mast Cells in the Brain of the Hedgehog (Erinaceus europaeus Lin.). Distribution and Seasonal Variations
Authors: Krüger Göran
Published: April 2010

The distribution and seasonal variations in the numbers of mast cells in the brain of 27 hedgehogs (Erinaceus europaeus Lin.) were investigated. Mast cells are numerous in thalamus and are mostly found in close proximity to blood vessels. Mast cells are frequently found in pedunculus cerebellaris, and they are always seen in the ependymal cell layer of the 4th ventricle. It was shown that the number of mast cells in thalamus is increased during hibernation and that the brains of females contain more mast cells than those of males. The phsyiological role of the increase in the number of mast cells during hibernation is discussed.
The Function of the Acetylcholinesterase Cells of the Pars distalis of the White‐crowned Sparrow Zonotrichia leucophrys gambelii
Authors: Haase Eberhard , Farner Donald S.
Published: April 2010

When testicular growth is induced in photosensitive white‐crowned sparrows (Zonotrichia leucophrys gambelii) by photoperiodic stimulation, there is an accompanying appearance of acetylcholinesterase‐containing cells in the pars distalis. Such cells do not appear in photorefractory birds subjected to long daily photoperiods; gonadal growth does not occur in these. To study further the function of these AChE‐containing cells, the activities of the thyroid gland, the adrenal cortex, and the gonads were inhibited or eliminated in photorefractory birds. No AChE cells appeared with the induction of increased TSH secretion with treatment of propylthiouracil and thiourea. Similarly adrenalectomy, treatment with metyrapone (2‐methyl‐1, 2‐di‐3‐pyridyl‐1‐propanone) as well as castration of photorefractory birds failed to cause the appearance of these cells. On the other hand, castration of photosensitive males and treatment with long days caused the development of AChE cells which, in comparison with the control, non‐castrated photostimulated males, were hyperplastic and hypertrophied. This supports our earlier suggestion that the AChE cells are gonadotropin producing cells.
On Structure and Morphologic Variation of Normal Pore System in Recent Cytherid Ostracoda (Crustacea)
Authors: Omatsola M. E.
Published: April 2010

The examination of some Cytherid (or Cytheracean) ostracodes with the aid of the scanning electron microscope reveals that there is a high degree of variation in the structure and morphology of the normal pore system. The structural and morphologic polymorphism of these normal pores, the taxonomic importance of the variations, and their probable functional morphology are critically examined and discussed.
Studies on the Blood Glucose Level in Channa punctatus (Bloch.)
Authors: Khanna S. S. , Singh Tejendra
Published: April 2010

The normal blood glucose level of Channa punctatus undergoes a seasonal change. A post‐spawning hyperglycemia is found during August, September, October and November. Fish kept out of water show increase in blood glucose level upto 24 hours. When returned to water, the asphyxial hyperglycemia subsides after 24 hours. Starvation does not appear to affect the blood glucose in this fish.
Light and Electron Microscope Studies of Some Annelid Setae
Authors: Orrhage Lars
Published: April 2010

An account of a light and electron microscope study of the setae of Disoma multisetosum, Pectinaria belgica (Polychaeta sedentaria) and Echiurus echiurus (Echiuroidea) is given. The results are compared with those of previous researchers, and the possibility of using the ultrastructure of the “annelid seta” as a phylogenetic‐systematic instrument is preliminarily discussed.
Analyse du caryotype de cinq espèces de planaires par la méthode du choc hyp otonique
Authors: Dutrillaux B. , Lenicque P.
Published: April 2010

An air drying method for karyotype analysis of Planarian worms is described. Five species are analysed (D. lugubris, D. tigrina, D. gonocephala, C. alpina and P. felina).

Some differences and similarities are detected, both in quantitative and qualitative respects. All the chromosomes can be clearly identified. The haploid number ranges from 4 to 9. An attempt to tackle the difficult problems of phylogenic aspect, and chromosomal variation in the somatic cells of D. gonocephala, is presented.

Les auteurs présentent une technique d'analyse du caryotype des Planariidae, par choc hypotonique.

Les caryotypes de 5 espèces (D. lugubris, D. tigrina, D. gonocephala, C. alpina et P. felina) sont décrits et comparés.

Des différences et des analogies sont ainsi mises en évidence dans le genre Dugesia, où une étude phylogénique est ébauchée.

Le problème de la variation chromosomique des lignées somatiques, chez D. gonocephala est envisagé.
Light Microscopy of Living Neurosecretory Cells of the Corpus cardiacum of Schistocerca gregaria
Authors: Krogh I. M.
Published: April 2010

Desert locust corpora cardiaca have been treated with hydrolytic enzymes in saline solution in order to facilitate separation of individual intrinsic cells. Some of the enzymes digested the basal lamina covering the corpus cardiacum, and also the intercellular cementing substance. Living neurosecretory cells with axonal projections could be isolated and observed by phase contrast microscopy or by darkfield illumination. By morphological criteria the secretory cells should be characterized as neurons, and two different types of secretory neurons have been identified. Brownian movement of cytoplasmic particles occurs in damaged cells and is regarded as a post mortem phenomenon.
The Origin of the Chordates
Authors: Jollie Malcolm
Published: April 2010

The study of development and comparisons of the adult structures of the several groups of protochordate animals reveals something of their interrelationships and origin. The hemichordates are perhaps closer to the echinoderms than to the chordates, but these groups appear to have been derived from a bilaterally symmetrical dipleurula ancestor, not from a sessile pterobranch‐like form. The origin of the chordates is speculative but the idea of a prototunicate stage is rejected. The tunicate is viewed as a highly modified end product, with fewer similarities to the ancestral form than amphioxus. Amphioxus is quite suggestive of the vertebrate, yet it is more like the tunicate in the details of its embryology and along with that rather extreme peripheral group is best thought of as constituting a subphylum, the Acraniata.

The idea of the early vertebrate as a filter feeder must be rejected since it is assumed here that perfection of that function led to a sessile or inactive way of life (as in the acraniates or lamprey larva) and failed to lead to the active creature with highly developed sensory, neural, and locomotor systems identified here as the protovertebrate. Further, the muscular plastic pharynx and moveable mouth of the protovertebrate suggest feeding on larger organisms, predation, and the abandonment of ciliary water‐current feeding.
The Spermatozoon of Siboglinum (Pogonophora)
Authors: Franzén Åke
Published: April 2010

The spermatozoon and some spermatid stages of Siboglinum (Pogonophora) have been examined by light and electron microscopy. In the spermatozoon a helical acrosome, a helical nucleus and a “body” with axonema follow each other in normal sequence. Head and tail are joined by a very short neck region containing two modified centrioles. The posterior portion of the nucleus is surrounded by a mitochondrial sheath consisting of three tightly wound mitochondrial helices. In the main portion of the tail the 9+2 unit is sorrounded by a granular sheath of dense material. In the neck region a centriole adjunct develops into a dense substance containing about nine rods.

At an early stage, when the centriolar apparatus and flagellum become associated with the nucleus, three large mitochondria with fairly regular cristae are seen at the base of the nucleus. A well developed Golgi apparatus is present in early stages. Rows of microtubules are observed encircling the spermatid nucleus.

Compared with the primitive type of spermatozoon the pogonophore sperm shows elongated and specialized nucleus, acrosome and mitochondria. It is concluded that the ancestral form must have had a fairly primitive spermatozoon and that evolution has proceeded towards a modified sperm with complicated spiral structure in connection with the evolution of a modified biology of fertilization, viz. specialized spermatophores. It is not known how the spermatophore discharges the spermatozoa nor how the spermatozoa find their way to the eggs. Two kinds of sperms are produced in the gonads of Siboglinum. The atypical sperm is smaller than the typical one.
The Resemblance of Bryozoan Gizzard Teeth to “Annelid‐like” Setae
Authors: Gordon Dennis P.
Published: April 2010

Abstract The gizzard teeth of a bryozoan (Bowerbankia imbricata) are found to be the structural homologues of certain epidermal derivatives, popularly known as “annelid‐like” setae.
Scanning Electron Microscopic Observations of the Mesenchyme Cells in the Larvae of the Starfish Pisaster ochraceus
Authors: Chia Fu‐Shiang
Published: April 2010

The are two morphological types of mesenchyme cells, bipolar and multipolar, and both are derived from the tip of the archenteron at the gastrula stage. Some of the cells form larval muscle and others may be involved in the stomodeum and coelomic pouch formation.
Relation Between Testosterone Levels in Serum and Proteolytic Activity in the Neck Muscles of the Norwegian Reindeer (Rangifer tarandus tarandus)
Authors: Lund‐Larsen Tata Ringberg
Published: April 2010

The characteristic hypertrophying of the male reindeer neck muscles during the rutting period, which coincides with the rise in serum testosterone levels, is found to be accompanied by a significant decrease in lysosomal proteolytic activity of the neck muscle cells.

Conversely, during the period of neck muscle involution following the rapid decline in serum testosterone after the rut, a marked increase in neck muscle proteolytic activity is found. These changes in lysosomal activity do not parallel the changes in feed consumption and nutritional stage of the animals during the rutting period. The lysosomal proteolytic activity of the male reindeer neck muscles thus may be, at least partly, under the control of sex steroid hormones.
Ultrastructure of the Respiratory Epithelium in the Lungs of the Newt Triturus cristatus
Authors: Meban Cowan
Published: April 2010

The respiratory epithelium in the lungs of the newt Triturus cristatus has been studied by electron microscopy. The entire pulmonary gas‐exchange area is covered by a continuous epithelium, the cells of which are all of the same type and are termed “pneumonocytes”. Typically each pneumonocyte is squamous and has attenuated sheets of cytoplasm which cover the pulmonary capillaries. Its free surface bears microvilli while mitochondria, multivesticular bodies and small inclusions are prominent in its cytoplasm. Many pneuomonocytes send cytoplasmic processes deep into the substance of the lung wall. It is postulated that these processes may help to anchor the epithelium.
Chromosome Number of Cidaris cidaris (Cidaridae, Echinoidea)
Authors: Colombera Dario , Vitturi R. , Zanirato L.
Published: April 2010

The diploid number 44 has been determined, with reserve, for the echinoid Cidaris cidaris, thus further supporting the hypothesis that the phylum Echinodermata is characterized by an astonishing stability of chromosome numbers. The spermatogonial chromosomes of C. cidaris are very minute and heterocyclic elements are absent.
Cyclical Changes in the Testis of the Hagfish Eptatretus burgeri (Cyclostomata)
Authors: Patzner Robert A.
Published: April 2010

The development of the spermatogenetic stages in the testis of the hagfish Eptatretus burgeri was studied by means of histological techniques. These animals have an annual reproductive cycle with a spawning season in October. Spermatocytes begin to appear in January and reach a maximum in March. The development of spermatids of stage I and stage II starts in April and June, respectively. In August about 35% of the testicular follicles contain spermatids of stage II. The gonadosomatic index shows a more or less constant increase from November until August. During the spawning season, no animals with well developed testis could be trapped. About 10% of male hagfish bear undeveloped gonads.
The Fine Structure of the Echinoderm Cuticle and the Subcuticular Bacteria of Echinoderms
Authors: Holland Nicholas D. , Nealson Kenneth H.
Published: April 2010

A cuticle, consisting of fibrous and sometimes granular material, covers the epidermal cells of crinoids, echinoids, asteroids, ophiuroids and holothurians. The tendency for the echinoderm cuticle to dissolve during fixation in phosphate‐buffered glutaraldehyde accounts for several previous reports that echinoderms have no cuticle. Depending on the species, there are from one to three cuticular sublayers. Abundant epidermal microvilli penetrate the cuticle of crinoids, echinoids and asteroids, but such microvilli are rare in ophiuroids and holothurians. The ophiuroid cuticle is especially modified, since numerous pinched‐off tips of microvilli are included in its outer layer, and its inner layer may be very thick. The discussion includes speculations on cuticle evolution, with special reference to the deuterostomes. Each echinoderm studied, except the two holothurians, harbors one or two morphological types of bacteria between the cuticle and the epidermal cells and/or embedded in the inner layer of the cuticle. These subcuticular bacteria are spindle‐shaped in Antedon, spiral in Echinocardium, encapsulated rods in Ophiothrix, rods in Ophiura, and a mixture of rods and spirals in both Psammechinus and Astropecten. The discussion considers the possible significance of this widespread, specific and apparently non‐pathologic association between echinoderms and their subcuticular bacteria.
The Vascularization of the Anuran Brain
Authors: Albrecht Ursula , Lametschwandtner Alois , Adam Hans
Published: April 2010

The angioarchitecture of the cerebellum of the toad, Bufo bufo (L.) (Amphibia, Anura) was studied by scanning electron microscopy of vascular corrosion casts. An arterial supply similar to that in the frog by small branches of the superior mesencephalic artery and by terminal branches of central arteries was found. The drainage was demonstrated via mesencephalon (rostro‐dorsal cerebellar regions), rhombencephalon and choroid plexus of the fourth ventricle (auricular areas) as well as via numerous branches of the lateral mesencephalic veins. These vessels leave from different levels of the cerebellum.

By comparing corrosion casts with light microscopical sections a correlation between histological structures and vascular patterns was found. The dominating transverse course of the vessels of the Purkinje cell layer was pointed out. Some advantages and limitations of the method used were discussed. To solve the most deplorable disadvantage—the impossibility to receive information about the direction of blood flow—a speculative consideration was presented and opened to discussion.
Biology of the Wild Rabbit, Oryctolagus cuniculus, in Southern Sweden
Authors: Borg Bertil , Andersson Mats , Meurling Patrick
Published: April 2010

The uterine histology of wild rabbits caught in the non‐reproductive season in the Revinge area in southern Sweden was studied (as part of a larger study on the biology of the wild rabbit). The uteri of the yearlings—which do not reproduce—had a low weight and a juvenile histology with a relatively thick, cell‐sparse lamina propria and a weak muscular layer. After the breeding season the uteri of the adults gradually entered a regressed winter state, characterized by a well‐developed muscular layer, a thin, cell‐dense lamina propria and a low mucosal epithelium with few glands. A few yearlings that had ovulated shared this picture. The regressive state gradually disappeared in spring.
VIP‐, Bombesin‐ and Neurotensin‐Like Immunoreactivity in Neurons of the Gut of the Holostean Fish, Lepisosteus platyrhincus
Authors: Holmgren Susanne , Nilsson Stefan
Published: April 2010

VIP‐like immunoreactivity was found in nerve fibres in all layers of the gut wall in both stomach and intestine, and was abundant in the myenteric and submucous plexuses. A few fibres were associated with blood vessels. Nerve cells showing VIP‐like immunoreactivity were found in the myenteric plexus. Neurotensin‐like immunoreactivity was found in nerve cells and numerous nerve fibres in the myenteric plexus of both stomach and intestine and in nerve fibres of the circular muscle layer, while bombesin‐like immunoreactivity was confined to a low number of nerve fibres in the myenteric plexus of the stomach. The results indicate that a VIP‐like, a neurotensin‐like and a bombesin‐like peptide are present in neurons of the gut of Lepisosteus.
Relationships Between Cytoplasmic Filaments and Nuclear Envelope in Teleost (Pimelodus maculatus) Endothelial Cells
Authors: Ferri Sylvio
Published: April 2010

In the present report a characteristic pattern showed by cytoplasmic filaments (intermediate‐sized and actin‐like) in the perinuclear area of a freshwater teleost (Pimelodus maculatus) endothelial cells is described for the first time. Thus, many intermediate‐sized filaments are directly inserted in the nuclear envelope, but others are connected to one another and to the nucleus through microfilaments. It is suggested that these particular relationships between the nucleus and cytoplasmic filaments are responsible not only for nuclear anchorage, but also for nuclear movements
Ciliated Receptors in the Pharyngeal Terminal Buds of Larval Lampetra planeri (Bloch) (Cyclostomata)
Authors: Baatrup Erik
Published: April 2010

Terminal buds on the gill arches of larval Lampetra planeri have been investigated by scanning and transmission electron microscopy. Each terminal bud is composed of two types of elongated cells, which extend from an apical depression to the basal lamina; one type bears a pair of cilia and the other, microvilli. In addition there are peripheral and basal cells. Nerve‐fibre profiles are lacking within the terminal bud epithelium and contacts between nerves and ciliated cells are established through holes in the basal lamina. The presence of ciliated receptor cells with such a mode of innervation presents a distinct contrast to the morphology of the taste buds of gnathostome vertebrates.
The Presence of Helminths in a Southern Hemisphere Lamprey (Geotria australis Gray), With a Discussion of the Significance of Feeding Mechanisms in Lampreys in Relation to the Acquisition of Parasites
Authors: Lethbridge R.C. , Potter I.C. , Bray R. A. , Hilliard R.W.
Published: April 2010

This paper reports for the first time the presence of helminths in the gut and coelomic cavity of Southern Hemisphere lampreys. Moreover, the records of Pelichnobothrium and Hepatoxylon in the lamprey Geotria australis are also the first records of these helminth genera in any species of lamprey. A consideration of the literature on the parasites and feeding mechanisms of lampreys provides good evidence that those parasites which are found in adult lampreys but typically utilize arthropod intermediate hosts are obtained via the food ingested by the lamprey's host fish.
Ultrastructure of the Spermatozoon of Squilla mantis
Authors: Cotelli Franco , Donin Carla Lora Lamia
Published: April 2010

The specialized spermatozoon of Squilla mantis (Crustacea, Stomatopoda) is round and non‐motile. It is surrounded by an electron‐dense coat, contains a small acrosomal complex, two centrioles consisting of nine doublets and few cellular organelles, while a nucleus sensu stricto is not recognizable. The plasma membrane shows some groove‐like characteristic invaginations. The morphology of this specialized gamete is discussed and compared with that of other Malocostraca.
Terminal Buds in the Branchial Tube of the Brook Lamprey (Lampetra planeri (Bloch))—Putative Respiratory Monitors
Authors: Baatrup Erik
Published: April 2010

Scanning and transmission electron microscopy showed that the sensory buds are structurally similar to those on the gill arches of the larva. They are composed of ciliated receptors, microvillous supporting cells, peripheral cells and, occasionally, Merkel cells. The connection between receptors and nerves is unusual among vertebrate sensory organs, appearing like a reversed neuromuscular junction. From their structure and localization it is suggested that the terminal buds are chemoreceptive organs involved in evaluation of the respiratory water.
Ultrastructural Studies on Gametogenesis of the Prawn Palaemon serratus (Pennant). I. Oogenesis
Authors: Papathanassiou E. , King P. E.
Published: April 2010

The oogenesis of the common prawn P. serratus is described. The reproductive cycle is annual and there is little evidence for a second spawning period. Oogenesis under the electron microscope follows a typical crustacean pattern and has been divided into seven stages according to the structure of the oocytes. The production of yolk is mainly intra‐oocytic, with a small extra‐oocytic contribution. Yolk, in the form of small granules, arises within the lamellar elements of the rough endoplasmic reticulum. These were then transformed into finely granular yolk bodies. Lipid droplets, as in other crustacean species, arise de novo in the cytoplasm and there is no association between lipids and cell organelles.
Structure and Innervation of Inner Ear Sensory Epithelia in the European Eel (Anguilla anguilla L.)
Authors: Mathiesen Carsten
Published: April 2010

Hair cell orientations of all inner ear sensory epithelia in glass eel, yellow eel and silver eel are presented. The patterns of hair cell orientation do not change with age. All sensory epithelia increase in area during growth of the eel. Examination of the hair cell population in macula utriculi show constant hair cell densities and increased hair cell population during development. Further, regional differences in hair cell densities and hair cell types are observed. The hair cells/axons ratio increases 3‐fold from glass eel to silver eel stadium. Nerve stainings in silver eel reveal complex innervation patterns with large stubby fibres confined to restricted regions. Histograms of nerve fiber diameters show marked differences from glass eel to silver eel. Growth of sensory epithelia is discussed.
Does the Manatee Have a Pineal Body?
Authors: Ralph Charles L. , Young S. , Gettinger R. , O'Shea T. J.
Published: April 2010

The brain of an adult, female manatee (Trichechus manatus) was prepared for histological examination of the region of the diencephalon and mesencephalon, where the pineal body typically would be located. Careful examination of hematoxylin‐eosin stained, interrupted serial microtomy sections revealed that this animal has a tubular epiphyseal recess apparently lacking organic pineal differentiation. There was no cytological evidence of pinealocytes in the vicinity of the atypical pineal rudiment.
Functions of Scales and Photophores in Mesopelagic Luminescent Sharks
Authors: Reif Wolf‐Ernst
Published: April 2010

In sharks bioluminescence is only known from the family Squalidae. It evolved independently in two out of six squalid subfamilies, Dalatiinae and Etmopterinae. The distribution of photophores was mapped in several species. It is suggested that in the Dalatiinae, which do not school, but migrate vertically, luminescence serves as ventral countershading. The Etmopterinae school and feed close to the bottom. Their luminescence is an aid in schooling. Four different placoid scale patterns are found in luminescent sharks and they allow to accommodation the photophores in the skin.
Distribution and Structure of the Adrenocortical Homolog in Polypterus palmas Ayres
Authors: Youson John H. , Butler David G.
Published: April 2010

The identity, distribution and structure of the adrenocortical homolog (AH) was made in Polypterus palmas Ayres using routine light and electron microscopy and histochemistry for the enzyme δ5‐3β‐hydroxysteroid dehydrogenase (3β‐HSD). The AH is confined to yellow corpuscles which are positioned near the posterior cardinal and renal veins in the anterior two‐thirds of each kidney. The 46–57 spherial to cigar‐shaped corpuscles are placed end to end and are equally distributed in the kidneys. The tortuous cords of epithelial cells of each corpuscle are surrounded by sinusoids and are completely delimited from the haemopoietic and renal tissue of the kidneys. The steroidogenic nature of the cells is demonstrated by their 3β‐HSD activity and their ultrastructure, namely lipid droplets, tubular smooth endoplasmic reticulum and mitochondria with tubulovesicular cristae. Giant mitochondria and gap junctions are notable features of AH cells in this fish. The yellow corpuscles of the kidneys in P. palmas represent the AH and this tissue has a distribution which is in accordance with the taxonomic position of Polypteriformes.
Gap Junction Modification in Hepatic Cells of a Fasting Freshwater Teleost (Pimelodus maculatus)
Authors: Ferri Sylvio
Published: April 2010

Scarce information concerning gap junction modifications in liver cells is found in the literature. The fine details of gap junctions in the hepatocytes of the teleost Pimelodus maculatus fasting during 3 months are reported for the first time in the present study. In this experimental condition two forms of gap junction appear: a bulge‐like and a ring‐shaped form. The functional significance of these structures is discussed.
Glial Cells in Abdominal Ganglia of Crayfish
Authors: Cuadras Jordi , Martí‐Subirana Anna
Published: April 2010

Glial cells of abdominal ganglia of crayfish have been studied by transmission electron microscopy. Four cell types can be defined: (1) perivascular glial cells, close to the vascular spaces; (2) perineuronal glial cells, the processes of which ensheathe neuron perikarya; (3) adaxonal glial cells ensheathing axons; (4) neuropilar glial cells, associated with synapsing terminals in the neuropile.

Neuropilar glia, adaxonal glia and the system formed by perineuronal and perivascular glia separate different functional zones of the neurons from the hemolymph or the electron dense extracellular matrix. These glial arrangements could play a similar role in hemato‐neuronal transport. Gap‐like junctions between glia and neuron cell bodies are frequent and could be involved in direct triggering of glial activities related to neurons.