bluuebunny/crossref_metadata_2025 huggingface dataset:
Badgers and Badger Fleas: Strategies and Counter‐Strategies
Authors: Stewart Paul D. , Macdonald David W.
Published: September 2003

We examined the broad hypothesis that one function of grooming by the European badger (Meles meles) is to disadvantage (possibly by removal) parasitic badger fleas (Paraceris melis). We pursued two lines of investigation. First, we used infra‐red video analysis to examine the body areas reached by self‐ and allo‐grooming badgers. We expected that if grooming was important to disadvantage fleas then allo‐grooming would cover areas that could not be reached by self‐grooming. Badgers preferred dorsal allo‐grooming and ventral self‐grooming, and when combined, the overall amount of grooming per square centimetre of skin area provided even body coverage, pointing to a hygienic function, rather than a purely social function. Secondly, we examined fleas’ responses to simulated fur disturbance, characteristic of grooming. If grooming had no flea disadvantage effect, we would expect no response from fleas, and no directionality in their movement away from direct touch. The number of fleas encountered rapidly declined in successive 10‐s counts during simulated ‘grooming’ at the same site. When badgers were ‘groomed’ on alternate sides (mimicking the badgers’ rapid alternation of grooming position), there was a marked increase in fleas when grooming resumed on the original side. Similarly, when ‘grooming’ was suspended for 40 s, there was an initial increase in the number of fleas when ‘grooming’ was resumed. Disturbed fleas tended to run downwards relative to gravity and towards the posterior of the badger, following the direction of hair growth. This contrasted with the behaviour of fleas removed from badgers which tended to run upwards and jump. We concluded that the pattern of badger grooming and the fleas’ response to disturbance was consistent with a hypothesis that badgers and badger fleas have strategies and counter strategies to maximize and minimize contact (respectively) during grooming.
Predator Recognition and Learned Irrelevance in the Crayfish Orconectes virilis
Authors: Hazlett Brian A.
Published: September 2003

When individuals of the crayfish Orconectes virilis detect an unlearned danger cue (alarm odor) and a novel cue (goldfish odor) at the same time, they form a learned association and behave as if the novel cue is associated with increased predation risk (Hazlett et al. 2002). This study examined the potential for learned irrelevance in O. virilis and the circumstances under which blockage of the formation of a learned association could occur. If individuals experience a random pattern of alarm odor and goldfish odor over the days prior to the simultaneous detection of those two cues, no learned association is formed (= learned irrelevance). That is, there is no inhibition of responses to a food cue when goldfish odor is added if the crayfish has experienced a random pattern of the two cues. Learning was eliminated if the random pattern of cues was experienced before or after the simultaneous detection. To present the two cues (alarm and goldfish odors) to crayfish independently on separate days, the water containing goldfish odor had to be removed from the aquaria as the odor persisted at least 24 h. The importance of the learned irrelevance phenomenon on predator–prey interactions is discussed.
Natal Dispersal Patterns of a Subsocial Spider Anelosimus cf. jucundus (Theridiidae)
Authors: Powers Kimberly S. , Avilés Leticia
Published: September 2003

Species that alternate periods of solitary and social living may provide clues to the conditions that favor sociality. Social spiders probably originated from subsocial‐like ancestors, species in which siblings remain together for part of their life cycle but disperse prior to mating. Exploring the factors that lead to dispersal in subsocial species, but allow the development of large multigenerational colonies in social species, may provide insight into this transition. We studied the natal dispersal patterns of a subsocial spider, Anelosimus cf. jucundus, in Southeastern Arizona. In this population, spiders disperse from their natal nests in their penultimate and antepenultimate instars over a 3‐mo period. We tracked the natal dispersal of marked spiders at sites with clustered vs. isolated nests. We found that most spiders initially dispersed less than 5 m from their natal nests. Males and females, and spiders in patches with different densities of nests, dispersed similar distances. The fact that both sexes in a group dispersed, the lack of a sex difference in dispersal distance, and the relatively short distances dispersed are consistent with the hypothesis that natal dispersal results from resource competition within the natal nest, rather than inbreeding avoidance in competition for mates. Additionally, an increase in the average distance dispersed with time and with the number of spiders leaving a nest suggests that competition for nest sites in the vicinity of the natal nest may affect dispersal distances. The similar distances dispersed in patches with isolated vs. clustered nests, in contrast, suggest that competition among dispersers from different nests may not affect dispersal distances.
Predator Inspection Behaviour in a Characin Fish: an Interaction between Chemical and Visual Information?
Authors: Brown Grant E. , Magnavacca Gaelle
Published: September 2003

Recent evidence suggests that predator inspection behaviour by Ostariophysan prey fishes is regulated by both the chemical and visual cues of potential predators. In laboratory trials, we assessed the relative importance of chemical and visual information during inspection visits by varying both ambient light (visual cues) and predator odour (chemical cues) in a 2 × 2 experimental design. Shoals of glowlight tetras (Hemigrammus erythrozonus) were exposed to a live convict cichlid (Archocentrus nigrofasciatus) predator under low (3 lux) or high (50 lux) light levels and in the presence of the odour of a cichild fed tetras (with an alarm cue) or swordtails (Xiphophorus helleri, with an alarm cue not recognized by tetras). Tetras exhibited threat‐sensitive inspection behaviour (increased latency to inspect, reduced frequency of inspection, smaller inspecting group sizes and increased minimum approach distance) towards a predator paired with a tetra‐fed diet cue, regardless of light levels. Similar threat‐sensitive inspection patterns were observed towards cichlids paired with a swordtail‐fed diet cue only under high light conditions. Our data suggest that chemical cues in the form of prey alarm cues in the diet of the predator, are the primary source of information regarding local predation risk during inspection behaviour, and that visual cues are used when chemical information is unavailable or ambiguous.
The Cytology of the External Ear Canal in the Normal Dog and Cat
Authors: Tater K. C. , Scott D. W. , Miller W. H. , Erb H. N.
Published: September 2003

This study was conducted on 50 normal dogs and 52 normal cats in order to characterize the normal cytological findings in specimens taken from the vertical ear canal by swabbing. Yeast were detected in 96% of the dogs and 83% of the cats. Gram‐positive cocci were found in 42% of the dogs and 71% of the cats. Rods were not seen. In dogs, the median numbers per high‐power microscopic field (400× magnification) for yeast, cocci and keratinocytes were 0.2, 0 and 3.9, respectively. In cats, the median numbers were 0.2, 0.3 and 8, respectively. Nucleated keratinocytes were occasionally observed in both species, and should not be mistaken for a pathological process (parakeratotic hyperkeratosis).
Follow‐up Examinations of Bitches after Conservative Treatment of Pyometra with the Antigestagen Aglepristone
Authors: Trasch K. , Wehrend A. , Bostedt H.
Published: September 2003

The aim of this study was to determine the therapeutic success of the medical treatment of canine pyometra with the antigestagen aglepristone and to document the recurrence rate in relation to the time interval after treatment with antigestagens. In 48 (92.8%) of the 52 treated bitches, healing could be achieved within the first 3 weeks after the treatment had been started. One bitch died as a result of renal insufficiency; in three bitches there was no emptying of the uterus, so ovariohysterectomy became necessary. In these three patients, ovarian and endometrial cysts were present. Forty‐one bitches could be followed up for 3 months. Four animals developed a recurrence (9.8%). In three bitches ovarian cysts and cystic endometrial hyperlasia could be found intra  operationem. The development of 37 bitches could be followed for at least 1 year. Seven animals developed a pyometra again (18.9%). Two received a repeated treatment with aglepristone and have been free from recurrence for over 12 months. In 37 animals data on the subsequent sex cycles are available. In 22 bitches next heat started at the expected time, in seven animals heat started too early. In eight bitches the period of anoestrus was prolonged. Five of the six bred bitches delivered at least one litter.

The presented data show that treatment of pyometra by aglepristone results in a high healing rate. The recurrence rate can be minimized by the selection of bitches without ovarian cysts and cystic endometrial hyperplasia.
Pathological changes in the cerebral medullary arteries of five autopsy cases of malignant nephrosclerosis: Observation by morphometry and reconstruction of serial sections
Authors: Okeda Riki
Published: September 2003

Hypertension (HT) is a serious risk factor of not only cerebral infarction and bleeding, but also Binswanger's encephalopathy (BE). In BE especially, severe stiffening of the cerebral medullary arteries because of hypertensive changes with loss of medial smooth muscle cells (SMC) occurs, which induces diffuse atrophy of the cerebral white matter. But, it is not yet ascertained whether HT is particularly severe in BE. Therefore, a spectrum of the pathological changes of the cerebral arteries were investigated by reconstruction of serial sections and morphometry of the medial thickness in five autopsied patients with malignant nephrosclerosis (MN) of exacerbated form. Each presented clinically acute progression of long‐standing HT at the terminal stage and pathologically typical renal changes. The heartweight was 380–900 g. Morphometry of the medial thickness of the arachnoid arteries presented significant medial hypertrophy in four cases of MN, but in the medullary arteries it presented in only two cases with marked cardiomegaly of 700 g and 900 g. In four cases of MN, only a few medullary arteries showed slight pathological changes. However, in another case with cardiomegaly of 900 g, all 10 medullary arteries showed multiple segments of atheroma, medial SMC loss, and prominent dilatation; edematous concentric intimal fibrosis with luminal obstruction and atrophy of the white matter were absent. In conclusion, only one case of MN showing marked cardiomegaly of 900 g presented severe pathological changes of the cerebral medullary arteries comparable with those of BE, although other MN‐cases showing severe cardiac hypertrophy presented only trivial arterial changes. Therefore, the cerebral medullary artery seems to be protected from HT, yet it is involved in a case of severe and long‐standing HT inducing an extreme cardiomegaly.
6‐Formylpterin protects retinal neurons from transient ischemia–reperfusion injury in rats: A morphological and immunohistochemical study
Authors: Funakoshi Taisaku , Miyata Hajime , Imoto Toshiaki , Arai Toshiyuki , Endo Nobuyuki , Makino Keisuke , Yang Chun Hui , Ohama Eisaku
Published: September 2003

Neuroprotective effects of 6‐formylpterin (6FP) on transient retinal ischemia–reperfusion injury were evaluated in rats by means of counting the number of retinal ganglion cells, measuring the thicknesses of the inner plexiform and inner nuclear layers, and by immunohistochemical detection of apoptotic cells in the retina. Sixty‐one Sprague–Dawley rats (12 weeks, male, 295–330 g) were subjected to transient retinal ischemia–reperfusion by elevated intra‐ocular pressure (80 mmHg for 60 min). Intraperitoneal injection of 6FP (3.8 mg/kg) was performed before or after ischemia. The retina was histologically better preserved in rats with 6FP treatment than without 6FP treatment. 6FP showed more strong neuroprotective effects when it was administered before ischemia. The number of single‐stranded DNA‐positive cells in the retina also decreased remarkably in rats with 6FP treatment, especially when administered before ischemia. These results suggest that 6FP protects retinal neurons from transient ischemia–reperfusion injury, at least in part by inhibiting apoptotic cell death.
Pilocytic astrocytoma of neurohypophysis
Authors: Reí s Abdülkadir , Kuzeylí Kayhan , Çobanoğlu Ümit , Çakır Ertuğrul , Usul Haydar , Sarı Ahmet
Published: September 2003

A case of pilocytic astrocytoma of neurohypophysis is presented. The clinical, pathological and MRI features of a rare tumor of the neurohypophysis are described. A 5‐year‐old girl presented with a 3 month history of lethargy, im‐balance and visual disturbances. A MRI revealed a large suprasellar mass. Histopathological examination demonstrated a pilocytic astrocytoma. Its astrocytic nature was confirmed by positive immunostaining for GFAP and the findings of an electron microscopy.
A quantitative study of the pathological changes in cortical neurons in sporadic Creutzfeldt–Jakob disease
Authors: Armstrong Richard A. , Lantos Peter L. , Cairns Nigel J.
Published: September 2003

The frequency of morphological abnormalities in neuronal perikarya was studied in the cerebral cortex in cases of sporadic CJD (sCJD) and in elderly control patients. Three hypotheses were tested, namely that the proportion of neurons exhibiting abnormal morphology was increased: (i) in sCJD compared with control patients; (ii) in sCJD, in areas with significant prion protein (PrP) deposition compared with regions with little or no PrP deposition; and (iii) when neurons were spatially associated with a PrP deposit compared with neurons between PrP deposits. Changes in cell shape (swollen or atrophic cell bodies), nuclei (displaced, indistinct, shrunken or absent nuclei; absence of nucleolus), and cytoplasm (dense or pale cytoplasm, PrP positive cytoplasm, vacuolation) were commonly observed in all of the cortical areas studied in the sCJD cases. The proportion of neurons exhibiting each type of morphological change was significantly increased in sCJD compared with age‐matched control cases. In sCJD, neuronal abnormalities were present in areas with little PrP deposition, but at significantly lower frequencies compared with areas with significant densities of PrP deposits. Abnormalities of cell shape, nucleus and the presence of cytoplasmic vacuolation were increased when the neurons were associated with a PrP deposit, but fewer of these neurons were PrP‐positive compared with neurons between deposits. The data suggest significant neuronal degeneration in the cerebral cortex in sCJD in areas without significant PrP deposition and a further phase of neuronal degeneration associated with the appearance of PrP deposits.
Migration and differentiation of nuclear fluorescence‐labeled bone marrow stromal cells after transplantation into cerebral infarct and spinal cord injury in mice
Authors: Lee JangBo , Kuroda Satoshi , Shichinohe Hideo , Ikeda Jun , Seki Toshitaka , Hida Kazutoshi , Tada Mitsuhiro , Sawada Ken‐ichi , Iwasaki Yoshinobu
Published: September 2003

There is increasing evidence that bone marrow stromal cells (BMSC) have the potential to migrate into the injured neural tissue and to differentiate into the CNS cells, indicating the possibility of autograft transplantation therapy. The present study was aimed to clarify whether the mouse BMSC can migrate into the lesion and differentiate into the CNS cells when transplanted into the mice subjected to focal cerebral infarct or spinal cord injury. The BMSC were harvested from mice and characterized by flow cytometry. Then, the BMSC were labeled by bis‐benzimide, a nuclear fluorescence dye, over 24 h, and were stereotactically transplanted into the brain or spinal cord of the mice. The cultured BMSC expressed low levels of CD45 and high levels of CD90 and Sca‐1 on flow cytometry. A large number of grafted cells survived in the normal brain 4 weeks after transplantation, many of which were located close to the transplanted sites. They expressed the neuronal marker including NeuN, MAP2, and doublecortin on fluorescent immunohistochemistry. However, when the BMSC were transplanted into the ipsilateral striatum of the mice subjected to middle cerebral artery occlusion, many of the grafted cells migrated into the corpus callosum and injured cortex, and also expressed the neuronal markers 4 weeks after transplantation. In particular, NeuN was very useful to validate the differentiation of the grafted cells, because the marker was expressed in the nuclei and was overlapped with bis‐benzimide. Similar results were obtained in the mice subjected to spinal cord injury. However, many of the transplanted BMSC expressed GFAP, an astrocytic protein, in injured spinal cord. The present results indicate that the mouse BMSC can migrate into the CNS lesion and differentiate into the neurons or astrocytes, and that bis‐benzimide is a simple and useful marker to label the donor cells and to evaluate their migration and differentiation in the host neural tissues over a long period.
Intraepithelial carcinoma arising in an endodermal cyst of the posterior fossa
Authors: Monaco Roberto , Boscaino Amedeo , Di Blasi Arturo , D’Antonio Antonio , Profeta Giovanni , De Falco Raffaele , Nappi Oscar
Published: September 2003

Endodermal cysts of the central neuraxis are benign, non‐neoplastic epithelium‐lined cysts arising from endodermal tissue that have been displaced early in fetal life. Intracranial endodermal cysts are rare and usually located in the posterior fossa. The present study involves a 36‐year‐old man with a typical epithelial cyst in the posterior fossa. Microscopically, the cyst has a simple columnar epithelium with mucus‐producing cells, containing an area composed of dysplastic epithelium with evidence of an intraepithelial carcinoma. The atypical cells have a high proliferative fraction demonstrated by Ki‐67 immunostain. Based on these findings, the authors view this case as evidence of a malignant transformation of a classic endodermal cyst. The clinicopathologic features and a review of the literature are discussed.
Primary squamous cell carcinoma of the brain. A rare autopsy case
Authors: Shirabe Teruo , Fukuoka Keiko , Watanabe Akira , Imamura Kazuhiro , Ishii Ryoji
Published: September 2003

In the present study, a rare autopsy case of primary squamous cell carcinoma of the brain is described. The patient was a 49‐year‐old man who showed brainstem symptoms and signs. These included oculomotor, abducens and facial palsies, dysphagia, dysarthria, and long tract signs such as quadriplegia with Babinski's signs during the 3‐year and 6‐month course of his illness. Neuropathologically, poorly differentiated squamous cell carcinoma was seen in the pons, medulla oblongata, part of the midbrain and spinal cord, the base of the cerebellum, the hypothalamus, the optic chiasm, and the left parahippocampal gyrus. The base of the pons and medulla oblongata were extensively destroyed by tumor cells. The relevant literature regarding primary squamous cell carcinomas of the brain was reviewed, and the characteristic features of this rare condition were discussed.
Influence of experimental chronic hypertension on the cerebral and renal arteries of wild cats
Authors: Okeda Riki , Chen Qi , Meng Jin Song , Okada Shinobu , Tajima Tayoko , Meng Yanghong , Kuroiwa Toshihiko
Published: September 2003

The influence of chronic hypertension (HT) on the cerebral and renal arteries was examined pathologically and morphometrically in wild cats without a specific genetic background. Chronic HT for 8–15 months was induced by uninephrectomy and salt‐loading, and the blood pressure was monitored for a maximum of 5 months. The grade of systolic blood pressure elevation in each cat during the monitoring period was 21–51 mmHg. Histologically, the cerebral arachnoid and medullary arteries of all hypertensive cats showed a well‐preserved medial layer, and neither loss of medial smooth muscle cells, adventitial fibrosis or fibrinoid exudation was detected. This experimental model of chronic HT in wild cats for 8–15 months induced segmental intimal elastofibrosis of the arachnoid and renal arteries, but spared the cerebral medullary artery. The parenchymal changes in the brain were negligible. Morphometrically, the arachnoid artery in control cats had a significantly thinner media than the renal artery, and the medial hypertrophy of the arachnoid artery resulting from HT occurred significantly less frequently than that of the renal artery. These findings suggest that the arachnoid and medullary arteries are relatively well protected from HT, and that this may be characteristic of cerebral arteries in general and ascribed to autoregulation.
Anti‐Hu paraneoplastic syndrome presenting with brainstem‐cerebellar symptoms and Lambert–Eaton myasthenic syndrome
Authors: Nagashima Toshiko , Mizutani Yasuyuki , Kawahara Hiromasa , Maguchi Shiro , Terayama Yoshihiko , Shinohara Toshiya , Orba Yasuko , Chuma Takayo , Mano Yukio , Itoh Tomoo , Sawa Hirofumi , Sakai Koichiro , Motomura Masakatsu , Nagashima Kazuo
Published: September 2003

Paraneoplastic syndrome (PNS) with two distinct neurological features was reported in a 50‐year‐old man who presented initially with vertigo, ataxia, dysarthria, tremor, confusion, urinary retention and hypotension. Pulmonary X‐ray findings, class IIIb sputum cytology, and positive anti‐Hu antibody established the diagnosis of PNS associated with small‐cell lung cancer (SCLC). Two cycles of combined chemotherapy resulted in shrinkage of the lung tumor together with complete recovery of neurological symptoms and disappearance of anti‐Hu antibody. Relapse of SCLC 4 months later with re‐appearance of anti‐Hu antibody required additional chemotherapy and irradiation. Eight months later, when multiple liver metastasis of SCLC was noticed, muscular weakness with positive waxing phenomenon compatible with Lambert–Eaton myasthenic syndrome (LEMS) developed. Postmortem examinations revealed residual SCLC in the primary lung, and massive liver metastasis with generalized lymph node involvement, but no tumors in the CNS. In the cerebellum, there was a slight loss of Purkinje cells with torpedo formation but without apparent lymphocytic infiltration. The present PNS was unique in that the relapse of SCLC was accompanied by the appearance of anti‐Hu antibody, and that initial signs of brainstem‐cerebellar symptoms, encephalopathy and autonomic failure were replaced by LEMS coinciding with the tumor recurrence.
Non‐traumatic recurrent dissection and its spontaneous repair in the circle of Willis: Report of two autopsy cases
Authors: Ohtoh Takashi , Ono Yasuki , Iwasaki Yuzo , Sakurai Yoshiharu , Nishino Akiko , Arai Hiroaki , Suzuki Hiroyoshi , Namba Yoshio
Published: September 2003

Post‐mortem examinations of the circle of Willis in two cases of subarachnoid hemorrhage disclosed a wide spectrum of vasculopathy ranging from a minimal tear between the intima and media, and between the media and adventitia, to complete transmural disruption leading to the formation of pseudoaneurysms. The presence of coexistence of the focal lesions with complete replacement of the entire arterial wall with thick fibrous connective tissues and the vasculopathy was suggestive of the spontaneous repair of recurrent non‐traumatic dissection of intracranial arteries. The patients were 58‐year‐old and 43‐year‐old females. There was no history of injury to the head or neck in either case. They were hypertensive, but the degree of atherosclerotic changes in the circle of Willis was compatible with age. There was no histological evidence of vasculitis. The role of hypertension and medial mucoid degeneration in the genesis of non‐traumatic dissection of intracranial arteries was discussed.
Glycogen synthase kinase‐3β phosphorylates synphilin‐1 in vitro
Authors: Tanji Kunikazu , Toki Tsutomu , Tamo Wakako , Imaizumi Tadaatsu , Matsumiya Tomoh , Mori Fumiaki , Takahashi Hitoshi , Satoh Kei , Wakabayashi Koichi
Published: September 2003

α‐Synuclein is known to be a major component of Lewy bodies and glial cytoplasmic inclusions in the brains of patients with α‐synucleinopathies. Synphilin‐1, an α‐synuclein‐associated protein, is also present in these inclusions. However, little is known about the post‐translational modifications of synphilin‐1. In the present study, it is reported that synphilin‐1 is phosphorylated by glycogen synthase kinase‐3βin vitro. It is well known that protein phosphorylation is involved in various physiological phenomena, including signal transduction and protein degradation. Therefore, phosphorylation of synphilin‐1 may play an important role in the function of this protein in the brain.
A comparative immunohistochemistry of O6‐methylguanine–DNA methyltransferase and p53 in diffusely infiltrating astrocytomas
Authors: Yuan Qingguo , Matsumoto Kenichi , Nakabeppu Yusaku , Iwaki Toru
Published: September 2003

The DNA repair protein O6‐methylguanine–DNA methyltransferase (MGMT) removes mutagenic adducts from the O6 position of guanine, thereby protecting the genome against guanine : cytosine to adenine : thymine transition and, meanwhile, conferring tumor resistance to many anticancer alkylating agents commonly used in the treatment of malignant gliomas. Studies on the involvement of p53 protein in expression of the MGMT gene have provided conflicting results regarding the relation between p53 protein and MGMT gene expression. To examine the potential immunostaining pattern of MGMT expression and to evaluate the possible relationship between p53 and MGMT regulation, we assessed MGMT and p53 accumulation on 35 cases of diffusely infiltrating astrocytomas. With a few cases showing cytoplasmic staining, MGMT accumulation was mainly nuclear. The percentage of labeled tumor cells was lower in high‐grade astrocytomas than in low‐grade astrocytomas (P < 0.05). Additionally, p53‐immunopositive tumor cells were usually immunonegative to MGMT. Thus, it is suggested that MGMT expression is reduced during malignant transformation of diffusely infiltrating astrocytomas, and that mutant p53 protein might be associated with down regulation of the MGMT expression.
Ultrasound agents may open the blood–brain barrier in rats and aggravate pathologic consequences of experimental head trauma
Authors: Rooker Servan , Van Reempts Jos , Van Deuren Bruno , Borgers Marcel , Jorens Philippe G. , Paelinck Bernard P. , Verlooy Jan
Published: September 2003

Unilateral intracarotid injection of contrast agents may considerably destabilize the blood–brain barrier in rats. This leads to vasogenic edema in the ipsilateral hemisphere. Mortality and extravasation increased significantly when administration of these ultrasound contrast agents was followed by mild traumatic brain injury. Direct administration to the cerebral circulation is, therefore, indicative for edema‐related pathology and may amplify the consequences of experimental neurotrauma.
Mutualism can mediate competition and promote coexistence
Authors: Schmitt Russell J. , Holbrook Sally J.
Published: September 2003

Mutualistic interactions are not believed to promote coexistence of competitors because mutualisms produce positive feedbacks on abundances whereas coexistence requires negative feedbacks. Here we show that a mutualism between an anemonefish (Amphiprion) and its sea anemone host mediates the effect of asymmetrical competition for space between the anemonefish and another damselfish (Dascyllus) in a manner that fosters their coexistence. Amphiprion stimulates increases in host area, the shared resource, but social interactions cap the number of anemonefish to two adults per host. Space generated by the mutualism becomes differentially available to Dascyllus because the effectiveness of an anemonefish in excluding its competitor declines with increases in the area it defends. This alters Amphiprion's ratio of per capita intra‐ to interspecific effects and thus facilitates coexistence of the fishes. This mechanism may be prevalent in nature, adding another major pathway by which mutualism can enhance diversity.
Growth rate–stoichiometry couplings in diverse biota
Authors: Elser J. J. , Acharya K. , Kyle M. , Cotner J. , Makino W. , Markow T. , Watts T. , Hobbie S. , Fagan W. , Schade J. , Hood J. , Sterner R. W.
Published: September 2003

Biological stoichiometry provides a mechanistic theory linking cellular and biochemical features of co‐evolving biota with constraints imposed by ecosystem energy and nutrient inputs. Thus, understanding variation in biomass carbon : nitrogen : phosphorus (C : N : P) stoichiometry is a major priority for integrative biology. Among various factors affecting organism stoichiometry, differences in C : P and N : P stoichiometry have been hypothesized to reflect organismal P‐content because of altered allocation to P‐rich ribosomal RNA at different growth rates (the growth rate hypothesis, GRH). We tested the GRH using data for microbes, insects, and crustaceans and we show here that growth, RNA content, and biomass P content are tightly coupled across species, during ontogeny, and under physiological P limitation. We also show, however, that this coupling is relaxed when P is not limiting for growth. The close relationship between P and RNA contents indicates that ribosomes themselves represent a biogeochemically significant repository of P in ecosystems and that allocation of P to ribosome generation is a central process in biological production in ecological systems.
Death and people with learning disabilities: empowering carers
Authors: Bennett Dora
Published: September 2003

This study investigates the provision of loss and bereavement education to carers of people with learning disabilities within a small community home. The literature that informs this study reviews the history of care of people with learning disabilities, theories of education and theories of loss and bereavement. The research approach is a micro ethnographic one. It considers the results of an evaluation of an educational session based on 12 individual needs assessment interviews. Results show increased personal insight as a result of the educational session with carers being able to identify areas of change to care provision as an outcome. In conclusion, this study shows the place and value of a ‘small scale approach to training’ and promotes proactive care provision around loss and bereavement to people with learning disabilities.
Secure care and treatment needs of individuals with learning disability and severe challenging behaviour
Authors: Vaughan Phillip J.
Published: September 2003

A survey was undertaken within the catchment area of the Wessex Consortium (population 1.8 million) to identify the number of individuals with learning disabilities and challenging behaviour who were placed in or needed to be placed in secure care. Twenty‐nine men and six women were identified, the majority of whom were in out‐of‐area placements.

There is a need to develop a local long‐stay secure service offering a range of security measures and focusing on individuals who exhibit problems of violence and sexually inappropriate behaviour. Consideration should be given to providing small domestic style functional units as the preferred model of provision with a separate facility for a small number of women. The service should also be closely integrated with local community learning disability services.
The assessment of the sexual knowledge of a person with a severe learning disability and a severe communication disorder
Authors: Bell Dorothy M. , Cameron Lois
Published: September 2003

This paper arose as a consequence of joint working between therapists of two different disciplines – clinical psychology and speech and language therapy – on a case involving a young woman who required an assessment of her sexual knowledge and attitudes. It explains how the recent development of a method of communication for those with a severe communication disorder (Talking Mats) has meant that it has become possible to work with those who have a severe learning disability and poor communication. In the past, clients with both severe learning disability with poor communication may have been excluded from traditional and cognitive therapy, which was dependent to a large extent on verbal communication. This paper, therefore, is of value in extending the range of methods for assessment and intervention that may be used by a range of disciplines with people showing severe learning disabilities and severe communication disorder.
Occupational therapists' perceptions of the role of community learning disability teams
Authors: Lillywhite Alison , Atwal Anita
Published: September 2003

Multiprofessional working is a central aspect of current health and social care policy. A key aspect of teamwork is role perception. This article presents the findings of a small‐scale study of occupational therapists' perceptions of their core roles in specialist learning disability teams. It presents the views of community occupational therapists regarding the roles of other team members. The findings of this study suggest that occupational therapists emphasize their and other health and social care professionals' uniqueness through role delineation. There was little evidence of integration of roles and/or joint working. Recommendations are made to enhance multiprofessional working that should ensure that professionals respond more effectively by providing person‐centred quality services.
Dialysis Membrane and Modality in Acute Renal Failure: Understanding Discordant Meta‐Analyses
Authors: Teehan Geoffrey S. , Liangos Orfeas , Lau Joseph , Levey Andrew S. , Pereira Brian J. G. , Jaber Bertrand L.
Published: September 2003

Meta‐analyses of the published literature are increasingly being used, allowing similar clinical trials to be combined quantitatively, thereby increasing the precision of the estimation of treatment effect. Four meta‐analyses were recently published comparing the impact of dialysis membranes or dialysis modality on clinical outcomes of patients with acute renal failure (ARF) requiring renal replacement therapy. Two studies compared dialysis membranes in intermittent hemodialysis (IHD) and two studies compared continuous renal replacement therapy (CRRT) to IHD. The findings between each pair of meta‐analyses were discordant. This was due in part to the differences among meta‐analyses in inclusion and exclusion criteria, the paucity of randomized controlled trials, variation in individual study quality, and heterogeneity in the study populations and settings. Understanding these issues is important to properly interpret results from these meta‐analyses.
Ethical Issues in Dialysis Alan Spital, Series Editor: The Ethics of Organ Transplantation for Prisoners
Authors: Kahn Jeffrey
Published: September 2003

Organ transplantation for prisoners raises numerous ethical issues. Questions immediately emerge about how to justify the use of scarce organs for prisoners when law‐abiding citizens are waiting. The answer to whether and why we ought to perform organ transplants for prisoners lies in how we understand society's commitments to prisoners' health and health care, and whether being incarcerated changes the priority of a patient waiting for a transplant. While prisoners forfeit many freedoms, access to and the provision of adequate health care are guaranteed to them, and ought to include access to organ transplants.
Ethical Issues in Dialysis Alan Spital, Series Editor: Do Not Resuscitate Orders and Iatrogenic Arrest During Dialysis: Should “No” Mean “No”?
Authors: Ross Lainie Friedman
Published: September 2003

An iatrogenic arrest is a cardiopulmonary arrest induced by a therapeutic effort. Frequently cardiopulmonary arrests during hemodialysis (HD) are iatrogenic. In this article I consider the question of what to do when a cardiopulmonary arrest occurs during HD in a patient with a do not resuscitate (DNR) order. I consider and reject four arguments to override the DNR order: the principle of nonmaleficence, the efficacy of resuscitation, proximate cause, and physician error. Instead, I argue that respect for patient autonomy and patient goals means that DNR orders must be respected unless there is compelling evidence that overriding the DNR would be consistent with the patient's goals. If such evidence is lacking, the physician has no moral choice but to follow the DNR order literally. As such, nephrologists need better communication with their patients regarding advance care planning and better documentation of their communication once it has occurred.
Rehabilitation of Dialysis Patients Series Editor, Nany G. Kutner: An Integrated Approach to Care for Patients with Chronic Kidney Disease
Authors: Curtin Roberta Braun , Becker Bryan , Kimmel Paul L. , Schatell Dori
Published: September 2003

Although the Kidney Disease Outcomes and Quality Initiative (K/DOQI) guidelines serve to integrate the multiple stages of chronic kidney disease (CKD), in practice, the treatment of kidney disease over its progressive course may be somewhat fragmented. Because the provision of integrated care across the stages of kidney disease, is likely to be advantageous for both patients and care providers, a conceptual framework which graphically depicts the complex and chronic nature of kidney disease may prove useful. The Life Options Rehabilitation Advisory Council (LORAC) proposes a cycle diagram to reflect the chronicity and complexity of kidney disease and to emphasize a holistic perception of kidney disease the notion that kidney disease, from its inception to the worst‐case scenario outcome of kidney failure. The kidney disease cycle conceptualization can serve as a patient teaching aid and as a reminder of the communication, collaboration, and cooperation that are required among primary care physicians and practitioners in each of the specialty areas that address the spectrum of kidney disease.
Editorial Focus: Dialysis and Pregnancy: Pregnancy in Dialysis Patients: Where Do We Go From Here?
Authors: Hou Susan
Published: September 2003

Current guidelines for dialysis in pregnant women have been developed in response to occasional dialysis patients who unexpectedly become pregnant. These include prolonged dialysis times, generally 20 or more hours per week. The increased dialysis time requires careful monitoring of phosphorus and potassium which may be removed in excessive amounts. Target serum bicarbonate for a pregnant woman is 18–20 mEq/L. Patients require increased supplementation of water soluble vitamins particularly folate. Increased doses of erythropoietin are needed to meet the demands for increased red cell production occasioned by pregnancy. Hypertension is the greatest danger to the mother and extreme vigilance is required up to six weeks postpartum. Volume status is difficult to predict and can only be determined by repeated clinical assessment. Only 50% of pregnancies result in a surviving infant and in the best subgroups, no more than 75% of pregnancies are successful. Over 80% of live born infants are premature, often severely premature. The key to improving the outcome of pregnancy in dialysis patients lies in decreasing premature labor and premature rupture of membranes in the late second and early third trimester. To this end, it is important for obstetricians to recognize that the risk of prematurity in pregnant dialysis patients is as higher or higher than in any other group and that any intervention, including such measures as progesterone and oxytocin antagonists, used to prevent premature labor in other groups should be considered in dialysis patients.
Dialysis in Pregnant Women with Chronic Kidney Disease
Authors: Shemin Douglas
Published: September 2003

Pregnancy occurs uncommonly in women with chronic kidney disease (CKD) and fetal outcome tends to be poor, with high rates of prematurity and mortality. Dialysis, by complementing residual renal function, may improve fetal outcome in pregnant women with CKD. Although there are no prospective or randomized trials that examine the relationship between dialysis and fetal outcome, there is evidence that increased solute clearance, by early initiation of or intensification of dialysis, is beneficial for the health of the fetus. Case reports and observational studies from the United States, Belgium, and Saudi Arabia suggest that there is a relationship between successful pregnancy and the amount of dialysis received. Unfortunately, in these reports, measures of residual renal function and dialysis adequacy are lacking or incomplete. Nonetheless, compared to nonpregnant patients with CKD, in pregnant women with CKD it is reasonable to begin dialysis at a higher level of residual renal function in the hope of improving fetal outcome.
Endocrinology and Dialysis: Issue and Therapies Series Editor: Jean L. Holley: Pregnancy in Dialysis Patients: A Review of Outcomes, Complications, and Management
Authors: Holley Jean L. , Reddy Sai Subhodhini
Published: September 2003

Although uncommon, pregnancy occurs in women on chronic dialysis. In 1980 the incidence of pregnancy in women on dialysis was 0.9%. Studies from 1992 to 2003 indicate that pregnancy occurred in 1–7% of women on chronic dialysis. Half of the infants born to women on chronic dialysis survive. Of importance is that “intensive dialysis” of 16–24 hr/week is associated with improved infant survival. In this article, the incidence, duration, fetal and maternal complications, and outcomes of pregnancy in women on chronic dialysis are reviewed. The management of anemia, hypertension, electrolytes, bone minerals, and acid‐base parameters in the pregnant dialysis patient is also summarized. Recommendations regarding the dialysis prescription for the pregnant woman on hemodialysis (HD) or peritoneal dialysis (PD) are also made. The complex and precarious condition of the pregnant woman on dialysis requires close collaboration between the patient, nephrologist, dialysis staff, obstetrician, and neonatologist to maximize the chance of a successful pregnancy.
American Society of Diagnostic and Interventional Nephrology: Section Editor: Stephen Ash: Catheter Management Protocol for Catheter‐Related Bacteremia Prophylaxis
Authors: Beathard Gerald A.
Published: September 2003

This study reports a prospective observational study in which an infection prophylaxis protocol based on the National Kidney Foundation's Kidney Disease Outcomes and Quality Initiative (NKF‐K/DOQI) guideline 15 describing guidelines for the care of the tunneled dialysis catheter at the time of catheter hook‐up for dialysis was used. Catheter‐related bacteremia (CRB) incidence data were collected for a 24‐month study period and compared to retrospectively collected control data for the immediately preceding 9 months in the same patient population under the same conditions except for the prophylaxis protocol. The incidence of CRB fell from an average level of 6.97 per 1000 catheter‐days during the control period to an average of 1.68 during the study period. This change was statistically significant. Although the lowered incidence required 6 months to reach its maximum, the decreased infection rate was sustained. The average incidence during the last 18 months of the study period was 1.28 per 1000 catheter‐days. Staff compliance with the protocol did require repetitive education and assessment.
Klinische Anwendung C-Arm-basierter registrierungsfreier Navigation
Authors: Grützner P. A. , Vock B. , Wentzensen A.
Published: September 2003

Computerassistierte Operationsverfahren in der Unfallchirurgie finden eine zunehmende Verbreitung. Das Prinzip liegt in einer Verknüpfung von Bildinformationen mit intraoperativen Instrumenten und Implantatpositionen. Ohne Navigationshilfe erfolgt diese Verknüpfung der teilweise sehr komplexen Bilddaten mit der Position des Instruments im Kopf des Operateurs. Die Bildinformationen können aus präoperativ angefertigten Bildern, wie z. B. der Computertomographie oder der Magnetresonanztomographie aber auch aus intraoperativ angefertigten Bildern mithilfe eines konventionellen C‐Bogens bestehen. Zur Bildgebung steht im Operationssaal in der Regel ein Röntgenbildverstärker, der eine Instrumentenposition in Echtzeit nur in einer Ebene verfolgen kann, zur Verfügung. Nur wenigen Zentren ist es vorbehalten, intraoperativ Schnittbilddiagnostik mit Computertomographie oder MRT, mit einem entsprechend erheblichen logistischen und personellen Aufwand, durchzuführen. In der
unfallchirurgischen Routine kann ein für die Navigation ausgestatteter C-Bogen zu einer Verbesserung der Präzision und zu einer drastischen Reduktion der Strahlenbelastung für OP-Personal und den Patienten führen. Im folgenden Beitrag sollen das Prinzip, das Spektrum und der logistische und personelle Aufwand der C-Bogen-basierten Navigation dargestellt werden.
Burrow occupancy and productivity at coastal sooty shearwater (Puffinus griseus) breeding colonies, South Island, New Zealand: can mark - recapture be used to estimate burrowscope accuracy?
Authors: Jones Chris , Bettany Susan , Moller Henrik , Fletcher David , Cruz Justine de
Published: September 2003

Breeding colonies of sooty shearwaters ('muttonbird', tïtï, Puffinus griseus) on mainland New Zealand have declined in recent years. New data on burrow occupancy and colony productivity for seven sooty shearwater breeding colonies on the coast of Otago, New Zealand for the 1996–97 and 1997–98 breeding seasons are presented and analysed as part of a five-year data set. Detection of a burrow's occupants using a fibre-optic burrowscope may underestimate absolute occupancy rates, but is still of value in the analysis of trends. Detection probabilities estimated by the novel use of mark–recapture models corresponded with those of previous studies of the technique's accuracy. Mainland declines are associated with a lack of control of introduced mammalian predators at most mainland colonies superimposed on a global pattern of decline in the species' abundance. Large numbers of recovered carcasses and an absence of burrow activity at two small mainland colonies show the decline to extinction of these colonies over the five years of collecting data. At one mainland colony with intensive predator control, survival rates and parameter variances are comparable with those found on a predator-free offshore island. All other mainland colonies showed negligible breeding success. There was a significant positive relationship between egg survival and an index of relative adult survival, with an apparent threshold below which few eggs hatch. Adult survival during the breeding season is likely to be the most important parameter in maintaining a colony's viability.