bluuebunny/crossref_metadata_2025 huggingface dataset:
Ten‐year outcome of root fillings in the General Dental Services in England and Wales
Authors: Lumley P. J. , Lucarotti P. S. K. , Burke F. J. T.
Published: May 2008

Aim  To consider the survival of root canal treatment provided within the General Dental Services in England and Wales, with failure being defined as re‐treating of a root canal, apical surgery or extraction.

Methods  A data set was established consisting of patients, 18 years or older, whose birthdays were included within a set of randomly selected dates and whose restoration records contained the placement of one or more direct restorations or crowns in courses of treatment between September 1990 and January 2002. The history of each root canal‐treated tooth was consulted, and the next date for an intervention on the root canal of the tooth, defined as a re‐treatment, apical surgery or extraction, was obtained. Thus, a data set was created of root canal‐treated teeth, with the dates of root canal filling placement and the dates, if any, of re‐intervention.

Results  Data for over 80 000 different adult patients were analysed, and a total of 30 843 root canal‐treated teeth identified from the data over a period of 11 years. The proportion surviving without further treatment of the root canal was estimated at 74% within an observation time of up to 10 years, with survival being strongly correlated with the characteristics of the patient, including age and treatment history, with older patients having root canal treatment with earlier re‐intervention than those of younger patients.

Conclusion  Within the data set analysed, an estimated 74% of root canal‐treated teeth pass through 10 years without re‐treatment, apical surgery or extraction.
Treatment of an avulsed maxillary permanent central incisor by autotransplantation of a primary canine tooth
Authors: Sönmez D. , Dalci K. , Şen Tunç E.
Published: May 2008

Aim  To present a case in which an avulsed permanent maxillary central incisor was replaced by autotransplantation of a primary canine tooth.

Summary  The present case describes transplantation of a primary canine tooth into the space left by an avulsed permanent maxillary central incisor after a delay of several days. After root canal treatment, the primary canine tooth was extracted and placed into the prepared socket. To provide better adaptation of the donor tooth, the recipient alveolar site was remodeled using surgical burs. Semi‐rigid splinting was maintained for 15 days. The crown of the primary canine was reshaped with composite resin and with an interim prosthesis, preventing movement of the lateral incisor tooth into the space of the transplanted canine. After 24‐month follow‐up the autotransplanted primary canine showed ankylosis but the tooth was in an acceptable state. The use of permanent tooth autotransplantation has been well documented. However a literature search revealed only one case report on the autotransplantation of primary teeth.

Key learning points • Long term results of primary tooth autotransplantation are scarce but the procedure in this case report could be considered as a temporary space maintainer for the treatment of a patient with a lost permanent incisor under 10 years of age.

• Success of primary tooth autotransplantation may be affected by several factors, such as case selection, extra oral time, surgical and endodontic procedures.
Granulocyte colony‐stimulating factor induced reduction in pulpal necrosis
Authors: Yamasaki M. , Nakamura K. , Amano K. , Matsui H. , Nakamura H.
Published: May 2008

Aim  To examine the effect of recombinant granulocyte colony‐stimulating factor (G‐CSF) on the number and function of neutrophils and on the histopathology of pulpal inflammation in normal and neutropenic rats.

Methodology  The effect of G‐CSF on changes in pulpal tissue was investigated at 2, 4, 7, and 10 days after pulpal exposure of the mandibular first molar of normal rats and of those with methotrexate‐induced neutropenia. The area of pulpal necrosis was measured. The neutrophil count in peripheral blood was determined, and their phagocytosis and chemotactic reaction were also examined. Statistical significance was examined by use of the two way analysis of variance.

Results  In untreated rats, G‐CSF significantly (P < 0.05) increased the number of peripheral neutrophils and their chemotactic reaction, but did not affect pulpal inflammation. In methotrexate‐induced neutropenic rats, the phagocytosis and migration of neutrophils reduced, and the area of pulpal necrosis enlarged. After the G‐CSF injection, the decreases in neutrophil count and their functions significantly (P < 0.05) reversed, and the enlargement of pulpal necrosis inhibited.

Conclusions  These findings indicate that G‐CSF prevented the reduction in neutrophil function and reduced the pulpal necrosis observed in the neutropenic rats, and suggest that neutrophils defend against bacterial invasion in pulpal tissue.
Supporting breastfeeding mothers: qualitative synthesis
Authors: McInnes Rhona J. , Chambers Julie A.
Published: May 2008

Title.  Supporting breastfeeding mothers: qualitative synthesis.

Aim.  This paper is a report of a synthesis of mothers’ and healthcare professionals’ experiences and perceptions of breastfeeding support.

Background.  Despite increasing knowledge, breastfeeding rates remain relatively static and mothers continue to report dissatisfaction with their experiences of breastfeeding. Greater understanding of breastfeeding may be achieved through rigorous qualitative research, and there has been a recent increase in such studies.

Data sources.  Electronic databases and citation lists of published papers were searched for articles listed between 1990 and 2005 and updated in May 2007. Studies were included if they used qualitative methods, were published in English, explored an aspect of breastfeeding and were based in a westernized country.

Review methods.  Papers were included if they reported studies using qualitative methods to explore breastfeeding and were published in English and based in a westernized country. Each study was reviewed and assessed independently, key themes extracted and grouped, and secondary thematic analysis used to explore key concepts.

Results.  From the 1990–2005 search, five themes emerged in health service support of breastfeeding: the mother‐health professional relationship, skilled help, pressures of time, medicalization of breastfeeding and the ward as a public place. Social support had two themes: compatible and incompatible support. One additional theme emerged from the update to 2007: health professional relationships.

Conclusion.  Mothers tended to rate social support as more important than health service support. Health service support was described unfavourably with emphasis on time pressures, lack of availability of healthcare professionals or guidance, promotion of unhelpful practices and conflicting advice. Changes are required within the health services to address the needs of both mothers and staff.
Effects of intensive care unit noise on patients: a study on coronary artery bypass graft surgery patients
Authors: Akansel Neriman , Kaymakçi Şenay
Published: May 2008

Aims and objectives. The aim of this study was to measure the noise levels in specific locations of an intensive care unit and determine the disturbance levels of patients owing to noise.

Background. Studies have shown that hospital noise is a potential stressor for patients. Noise levels measured in the intensive care unit are mostly far beyond the recommended standards for hospitals, and generally measured around 60–70 dB (A). Although there are a few studies on noise levels in the intensive care unit, no study could be found that compares 24‐hour intensive care unit noise measurement data at several locations of intensive care unit.

Methods. The study was conducted with 35 coronary artery bypass graft surgery patients. The intensive care unit noise level was measured by using Bruel & Kjaer 2144 Model Frequency Analyzer next to the bed of each patient. A patient's disturbance owing to the intensive care unit noise was questioned.

Results. Noise levels ranged between 49 and 89 dB (A) with a mean of 65 dB (A). Peak noise levels were measured as high as 89 dB (A). The noise levels measured at different locations in the intensive care unit did not differ significantly. Noises created by other patients, those who were admitted from emergency room and operating room into intensive care unit, monitor alarms, conversations among staff were the most disturbing noise sources for patients.

Conclusion. The patients who were located in the bed which was closer to the nurses' station were more affected by the intensive care unit noise than other patients. Having a previous intensive care unit experience also affected the patients’ disturbance levels owing to noise.

Relevance to clinical practice. Nurses are in key positions where they can identify physical, psychological and social stressors that affect patients during their hospital stay. Staff education, planned nursing activities and proper design of intensive care unit may help combat this overlooked problem.
Violence in nursing homes: perceptions of female caregivers
Authors: Isaksson Ulf , Åström Sture , Graneheim Ulla Hällgren
Published: May 2008

Aim.  This study illuminates how female caregivers in nursing home perceive violence.

Background.  Previous studies have focused on prevalence and types of violence and injuries in various settings and among various professionals. There are, however, few studies that examine how caregivers perceive violence.

Methods.  Forty‐one female caregivers at nursing homes were asked to reflect on a vignette containing a situation where a female caregiver is exposed to violence from a male resident. The reflections were analysed by qualitative content analysis.

Findings.  The main finding indicates that perceiving an action as violent is in the eye of the beholder. Caregivers perceive violence to be challenging, intentional, excusable, ordinary and contextual relative to their own experience and attitudes.

Conclusion and relevance to clinical practice.  As the perception of violence is subjective, there is a risk that violent incidents will be under‐reported as well as over‐reported. To avoid this, it is important to construct a well‐defined operationalised definition of violence for research purposes. Our findings also indicate the need for individually structured and adjusted support for caregivers. To explore the complexity of violence, further research should focus on how caregivers and residents experience violence in a nursing home.
Development of intimal thickening of coronary arteries over the lifetime of Atlantic salmon, Salmo salar L., fed different lipid sources
Authors: Seierstad S L , Svindland A , Larsen S , Rosenlund G , Torstensen B E , Evensen Ø
Published: May 2008

The objective of the present study was to investigate the development of intimal changes of coronary arteries over the lifetime of farmed Atlantic salmon, Salmo salar L., fed either a 100% fish oil or a 100% vegetable oil blend. The study was performed as a randomized observer blinded controlled trial with parallel group design. At the start of the project, the fish were divided in two groups and sampled at five different time points throughout their life span. The total study sample consisted of 259 healthy fish. Serial sections were taken from the coronary artery lying on the bulbus arteriosus for histopathological evaluation and for area measurements using semi‐quantitative and quantitative methods. The earliest onset of vascular changes was detected in fish from both groups in the freshwater stage prior to smoltification. The mean range lesion (MRL), used to describe the severity of the lesions observed, increased significantly for both groups from sea transfer throughout the study period. Comparison of the two groups based on the overall material corrected for time of sampling did not show any difference (P = 0.20) between the two groups with regard to MRL. The percentage lumen loss (PLL) measured by a quantitative method and used as a measure to indicate lesion severity showed an incremental, non‐significant increase from week 72 to week 92 and further to week 115 in both diet groups during the seawater phase. Comparison of the groups corrected for time of sampling indicated a difference of PLL in favour of VO (P = 0.02). Heart weight, body weight and body length were all positively and significantly correlated to Log MRL. The partial correlation analysis indicated that heart weight was the most dominant variable in the set. Early vascular changes were found in the major bifurcation of the coronary artery at the apex and beyond the flow divider into the daughter branches. The latter represented the dominant changes and were found throughout the entire lifecycle of the fish. Increasing in size over time they formed pads or cushions that were regularly located close to the outer walls of the bifurcation. The origin of the cells forming the intimal thickening has not been conclusively determined, but immunohistochemical findings indicate a smooth muscle cell origin, possibly of a myointimal type. Our findings suggest there is no correlation between diet and intimal changes. The severity of the changes, MRL and PLL, of the coronary vessels correlate with heart weight and fish weight growth and growth rate and mechanical factors are implicated in intimal development, but rather than being induced by external injury due to the location of the coronaries, haemodynamic factors and low shear stress are proposed as the main mechanism behind these changes.
Doctors and nurses on wards with greater access to clinical dietitians have better focus on clinical nutrition
Authors: Thoresen L. , Rothenberg E. , Beck A. M. , Irtun Ø. ,   on behalf of the Scandinavian Nutrition Group (SNG)
Published: May 2008

Background  According to the Council of Europe, clinical dietitians should assume a more central role in nutritional support. The aim of this study was to assess the opinions among doctors, nurses and clinical dietitians regarding the use of clinical dietitians’ expertise in the hospital units and, further, to assess whether the presence of clinical dietitians in hospital departments influenced doctors and nurses focus on clinical nutrition.

Methods  A questionnaire about the use of clinical nutrition was mailed to 6000 doctors and 6000 nurses working in hospital units where undernutrition is documented to be common, as well as to 678 clinical dietitians working in Scandinavian hospitals.

Results  The response rate of clinical dietitians, nurses and doctors were 53%, 46% and 29%, respectively. Nurses and doctors who saw clinical dietitians often found it less difficult to identify undernourished patients and found that insight into the importance of adequate nutrition was better than those who saw clinical dietitians seldom. Clinical nutrition had a higher priority in units with frequent visits by clinical dietitians.

Conclusions  The present study shows that doctors and nurses on wards with greater access to clinical dietitians had better focus on clinical nutrition.
Multimodal sensory testing of the rectum and rectosigmoid: development and reproducibility of a new method
Authors: Brock C. , Nissen T. D. , Gravesen F. H. , Frøkjær J. B. , Omar H. , Gale J. , Gregersen H. , Svendsen O. , Drewes A. M.
Published: May 2008

Abstract  Evaluation of rectal and rectosigmoid sensation is important in basic, clinical and pharmacological studies. New methods to evoke and assess multimodal (electrical, thermal and mechanical) experimental pain of the upper gut activate distinct pathways and mimics clinical pain. The aims of the current study were to characterize the sensory response and reproducibility to multimodal stimulation of rectum and the rectosigmoid. A multimodal rectal probe was developed. Mucosal electrostimulation was delivered at the recto‐sigmoid junction. In Rectum, impedance planimetry was used for measurement of cross‐sectional area (CSA) during distension. Circulation of water within the bag at either 4 or 60 °C was applied for thermal stimulation. The method was tested in 12 healthy volunteers (six men mean age 32 years) on two subsequent days. Mechanical and sensory responses and referred pain areas were assessed. Stimulation with electrical, thermal and mechanical modalities resulted in different sensory perceptions. The relationship between stimulus intensity and sensory response was linear for all modalities. Sensory response to different modalities did not differ between investigation days (all P‐values > 0.1). Approximately 75% of subjects felt referred pain in distinct skin locations. Between‐days reproducibility was good for all modalities [intra‐class correlation (ICC) ≥0.6]. At sensory threshold, CSA showed best reproducibility (ICC ≥ 0.9). At pain detection threshold stretch ratio, CSA and electrostimulation showed best reproducibility (ICC = 1.0; 0.9; 0.9). The present model was easily implemented, robust and showed good reproducibility. It can be used to study pathophysiology or pharmacological interventions in healthy controls and in patients with diseases involving the distal hindgut.
SENSORY NERVE CONDUCTION VELOCITY AS CORRELATED TO FIBRE SIZE IN EXPERIMENTAL UNDERNUTRITION IN THE RAT
Authors: SIMA ANDERS , JANKOWSKA ELZBIETA
Published: May 2008

The nerve conduction velocity was examined in sensory dorsal roots of pre‐ and postnatally undernourished and well‐nourished control rats after supramaximal stimulation. Altogether forty‐eight roots were examined: twenty‐four from three undernourished rats 180 days of age, and twenty‐four serving as controls from three well‐nourished rats of the same age. It was found that the fastest sensory nerve conduction velocity was reduced in proportion to the reduction of the thickest myelinated fibres of the dorsal roots in undernourished rats.
α‐TOCOPHEROL RESPONSIVE MUSCULAR DYSTROPHY IN GUINEA PIGS
Authors: HOWELL J. McC. , BUXTON P. H.
Published: May 2008

Hind limb weakness occurred sporadically in a colony of guinea pigs. This was found to be associated with a severe myopathy. The myopathy was found to respond to a‐tocopherol administration. This was clearly demonstrated by a dramatic fall in CPK levels after treatment. The tissues of the animals and their pelleted food had very low contents of vitamins A and E.
THE EFFECT OF ACUTE RADIATION INJURY ON THE PERMEABILITY AND ULTRASTRUCTURE OF INTRACEREBRAL CAPILLARIES
Authors: OLSSON YNGVE , KLATZO IGOR , CARSTEN ARLAND
Published: May 2008

A study was made on the vascular permeability alteration produced in the rat brain 2 to 9 days after a single application of 30 krad of X‐rays. The permeability was assessed by fluorescence and electron microscopy following intravenous injection of Evans blue‐albumin (EBA) and horseradish peroxidase (HP). Both tracers penetrated vascular walls and spread extensively outside the vessels in the irradiated regions. The HP penetrated between separated endothelial cells or through gaps formed by necrotic endothelial cells. The vascular basement membranes and the perivascular astrocytes did not prevent the further diffusion of HP. Lesions of the vascular endothelium are considered to be of crucial importance for the extravasation of proteins in acute radionecrosis of the brain.
THE FINE STRUCTURE OF THE SPINDLE ABNORMALITY IN MYOTONIC DYSTROPHY
Authors: SWASH M. , FOX K. P.
Published: May 2008

The fine structure of the intrafusal muscle fibres, and of their innervation, has been studied in three muscle spindles found in muscle biopsies from two patients with myotonic dystrophy. The poles of the intrafusal muscle fibres were longitudinally fragmented. The fragments were arranged in up to twenty clusters, each bounded by a single layer of basement membrane. Degenerative and regenerative changes were observed in the fibre fragments. The most abnormal fragments were situated at the periphery of the clusters and there was some evidence that these degenerate fragments were extruded from the clusters, into the periaxial space. Many fibre fragments were anucleate. Only six motor endplates were found, despite a search of the spindle poles by serial section. All were simplified in form. The fine structure of the primary and secondary sensory innervation was normal, and the equatorial regions of the intrafusal fibres were not fragmented. It is suggested that these observations are consistent with the hypothesis that the characteristic spindle abnormality in myotonic dystrophy is due to fragmentation of the poles of the intrafusal muscle fibres, due to mechanical stresses imposed on abnormal muscle fibres by myotonia or myotonic after‐discharges, and that this, as a continuing process, leads to denervation of the individual fragments, and to the observed degenerative changes, at a time when the extrafusal muscle fibres may appear relatively mildly affected.
AMYLOID PLAQUES IN THE BRAINS OF MICE INFECTED WITH SCRAPIE: MORPHOLOGICAL VARIATION AND STAINING PROPERTIES
Authors: BRUCE MOIRA E. , FRASER H.
Published: May 2008

Amyloid plaques in the brains of mice infected with scrapie: morphological variation and staining properties

Cerebral amyloid deposits predominantly in the form of plaques are associated with experimental scrapie produced by particular agents in inbred mice. In this paper the staining properties and variation in the morphology of these deposits are described. At the light microscope level a discretionary classification into six types is made: shadowy plaques; amorphous plaques; stellate plaques; giant plaques; diffuse amyloid deposits; and perivascular amyloid deposits. It is shown that Masson's trichrome technique provides the most efficient staining method for identifying cerebral amyloid of all these types. A preliminary ultrastructural examination of stellate plaques confirms the presence of amyloid on the basis of characteristic fibrils and demonstrates that microglia and distended neurites are involved in the structure of the plaques. The similarities and differences between cerebral amyloid in scrapie and other forms of amyloid deposits in the brain, particularly kuru plaques and senile plaques, are discussed.
REGENERATION AND INNERVATION OF NORMAL AND DYSTROPHIC MUSCLE CULTURED WITH NORMAL AND DYSTROPHIC SPINAL CORD
Authors: GALLUP B. , DUBOWITZ V.
Published: May 2008

Teased strips of normal or dystrophic adult mouse muscle were cultured with embryonic normal or ‘dystrophic’ mouse spinal cord explants, in order to determine whether muscular dystrophy is of primary myopathic or neuropathic origin. When cultured with normal spinal cord, both normal and dystrophic muscle regenerated to form new cross‐striated muscle fibres with peripherally located nuclei and showing spontaneous, synchronized contractions. Silver impregnation and acetyl‐cholinesterase activity showed that neuromuscular junctions were formed. In marked contrast, both normal and dystrophic muscle cultured with spinal cord from dystrophic animals failed to show such functional regeneration, and neuromuscular junctions could not be identified. Only a few myotubes were formed, and these were rarely cross‐striated, had internal nuclei, and only some showed asynchronous fibrillatory contractions. These results strongly suggest that murine muscular dystrophy has a neural pathogenesis. Histochemical reactions were carried out on serial frozen sections of the regenerated muscle fibres, and also of embryonic mouse muscle cultured in cord‐myotome explants, to determine whether ‘fibre types’ were formed. All the fibres gave uniformly strong or medium reactions to phosphorylase, NADH‐TR, myofibrillar ATPase, ATPase after acid preincubation, and the PAS reaction for glycogen, except a few fibres in an embryonic muscle which gave weak reactions for all enzymes. Histochemical fibre types were not formed. Two studies of explants of human muscle in association with normal embryonic mouse spinal cord resulted in the establishment of functional neuromuscular contact and the production of well striated myotubes, with peripherally placed nuclei and spontaneous regular contractions.
THE NEUROPATHOLOGY OF THE FATTY LIVER AND KIDNEY SYNDROME OF CHICKS
Authors: WIGHT P. A. L.
Published: May 2008

Sudanophilic lipid, probably triglyceride, was present in perivascular locations and in the cytoplasm of small cells in the brains of chickens with FLKS. The lipid was most consistently observed and was most abundant in the optic tectum and the cerebellum but in severely affected cases many regions of the central nervous system were implicated. The medulla oblongata and spinal cord were least often involved. The grey matter was predominantly affected. Degeneration, demyelination and gliosis were absent and there was no histological evidence of reduced amounts of glycogen in the lumbar glycogen body. Neurons and satellite cells of the spinal ganglia and autonomic plexuses, the epithelium of the choroid plexus and the cells of the epiphysis cerebri contained abnormal accumulations of lipid. Electron microscopy revealed that the greater part of the lipid was in the perikaryon and processes, particularly the endfeet, of astrocytes. Some lipid was also present in ganglionic neurons. Apart from the lipid droplets, the astrocytes and all other cells observed at the ultrastructural level, were morphologically normal.
FETAL FORMS OF PYRUVATE KINASE ISOENZYMES IN TUMOURS OF THE HUMAN NERVOUS SYSTEM
Authors: BENNETT M. J. , TIMPERLEY W. R. , TAYLOR C. B. , HILL A. SHIRLEY.
Published: May 2008

The distribution of the isoenzymes of pyruvate kinase in a variety of normal human tissues, twenty‐eight fetal brains at varying stages of development and in thirty‐six tumours of the nervous system were investigated by cellulose acetate membrane electrophoresis. A total of three isoenzymes was found; Type L occurred nearest the origin, Type M2 was the most cathodal isoenzyme and Type M1 was intermediate in position. All bands were cathodal. Liver contained Type L and a small amount of M2; skeletal muscle contained Type M1; renal cortex contained predominantly M2 with a trace of L; adult brain contained predominantly M1 with some M2; and fetal brain contained proportionately more of the M2 isoenzyme than adult brain. A reversion towards the fetal pattern was found in the majority of gliomas studied and a similar pattern was seen in a variety of tumours of non‐glial cell origin. A fetal pattern was also noted in samples of brain showing no histological evidence of neoplasia removed from around the edge of gliomas. If this is a pre‐neoplastic biochemical change it could be of diagnostic use in early detection of some tumours.
ABERRANT REMYELINATION IN CHRONIC RELAPSING EXPERIMENTAL ALLERGIC NEURITIS
Authors: KING R. H. M. , POLLARD J. D. , THOMAS P. K.
Published: May 2008

Observations have been made on seven guinea pigs with relapsing or chronic progressive experimental allergic neuritis. All showed prominent hypertrophic changes with concentric Schwann cell proliferation. Abnormalities of myelination were observed in remyelinating fibres. These included the internodal termination of myelin lamellae, and the overriding of the myelin lamellae either at nodes of Ranvier or, at times, in the internodal region. The manner of origin of these appearances is discussed, as is their significance in relation to theories of myelinogenesis and their possible relevance to nerve conduction.
SPINAL CORD VASCULARITY. A HISTOPATHOLOGICAL AND ANGIOGRAPHIC STUDY OF THE EFFECTS OF THORACIC‐LUMBAR AORTIC MOBILIZATION IN THE RAT
Authors: TVETEN L. , LØKEN A. C.
Published: May 2008

A clinical, histopathological and microangiographical study has been performed in eighty‐three rats subjected to regional mobilization of the thoracic‐lumbar aorta. Paralysis or paresis of the hindlimbs was observed in about one‐fourth of the animals, predominantly in those subjected to an extensive mobilization of the aorta. A staged mobilization of the thoracic‐lumbar aorta separated by an interval of 1 week not only minimized the incidence of neurological complications but the severity as well. The topographical distribution of the histopathological changes varied considerably both in the longitudinal and the transverse plane of the spinal cord in different experimental groups as well as individually in the same group of animals. Typical lesions were dorsal spinal cord infarction and arterial watershed lesions at the base of the dorsal horn, in addition to circumscribed necroses of the white matter corresponding fairly well to venous watershed zones. Microangiographically, the preservation of the caudal cord in cases with massive infarction of the thoracic cord, is believed to be due to a number of intramedullary arterial anastomoses. Usually a sufficient collateral blood supply to the spinal cord is readily available even in the case of comparatively extensive aortic mobilization. Enlargement and tortuosity of the spinal cord arteries and the intersegmental anastomoses immediately outside the spinal canal suggest that these vessels are the most important sources in the re‐establishment of the collateral circulation.
ELECTROPHYSIOLOGICAL FINDINGS IN RATS WITH EXPERIMENTAL CARBON DISULPHIDE NEUROPATHY
Authors: SEPPÄLÄINEN ANNA MARIA , LINNOILA ILONA
Published: May 2008

Electrophysiological findings in rats with experimental carbon disulphide neuropathy

Rats were subjected to the inhalation of 750 parts/106 of carbon disulphide for 6 h daily, 12 rats being exposed for 22 weeks, and 15 rats from 2 to 5 weeks. The development of neuropathy was monitored bimonthly by measurement of the motor conduction velocity (MCV) in the sciatic nerve. A slight, but statistically significant slowing of the MCV was observable at 2 weeks, although no further reduction occurred during the following 3 weeks. Marked slowing of the MCV was demonstrated, concomitantly with the occurrence of difficulties in voluntary control of the hind limbs, at 8 weeks of exposure. After 22 weeks of exposure, 4 rats were allowed to recover for a further 12 weeks. Slight improvement in their MCV was observed, but it remained at a much lower level than that in the control group. No permanent alteration in the MCV occurred in those animals exposed for up to 5 weeks.
THE VALUE OF LDH ISOENZYMES IN THE RAPID DIAGNOSIS OF BRAIN TUMOURS
Authors: McCORMICK D. , ALLEN INGRID V.
Published: May 2008

The value of LDH isoenzymes in the rapid diagnosis of brain tumours

A combined biochemical and histopathological analysis of 126 intracranial tumour biopsies has been undertaken to assess the possible value of LDH isoenzyme analyses in differential diagnosis. LDH isoenzymes were separated by a simple electrophoretic technique and visualized by a histochemical staining method. The analytical results were quantitated in the densitometer. Using this technique it is possible to obtain results within 15 min of reception of the biopsy specimen and only small pieces of tumour material are required. The results of the investigation have shown that all the tumours investigated have an LDH isoenzyme pattern which is different from that of normal brain. Although in some cases the abnormal pattern was non‐specific it was found that certain general rules could be formulated, and the technique is a useful supplement to histological evaluation of frozen sections.
ASTROCYTE MITOSES AND ALZHEIMER TYPE I AND II ASTROCYTES IN ANOXIC ENCEPHALOPATHY
Authors: DIEMER N. H. , KLINKEN L.
Published: May 2008

Astrocyte mitoses and Alzheimer type I and I1 astrocytes in anoxic en‐cephalopathy

Numerous astrocyte mitoses, arrested in metaphase, were found in a case of anoxic encephalopathy. The number of chromosomes was not excessive, but in most the mitotic spindles appeared absent. Many Alzheimer type I and II astrocytes were also seen, together with a few cells containing both micronuclei and free chromosomes. The occurrence of such transitional forms supports the hypothesis that astrocyte mitoses arrested in metaphase constitute an intermediate stage in the formation of the tetraploid Alzheimer type I astrocytes from cells of Alzheimer type II.
IN VITRO CHARACTERISTICS OF A FOURTH VENTRICLE EPENDYMOMA MAINTAINED IN ORGAN CULTURE SYSTEMS: LIGHT AND ELECTRON MICROSCOPY OBSERVATIONS
Authors: VRAA‐JENSEN J. , HERMAN M. M. , RUBINSTEIN L. J. , BIGNAMI A.
Published: May 2008

Explants of a well‐differentiated fourth ventricle ependymoma were grown on collagen‐coated coverslips and in organ culture systems using gelatin sponge foam matrices and Millipore filter platforms. Viable explants were maintained on Millipore filter platforms up to 44 days and on sponge foam matrices up to 86 days. The structure of ependymal rosettes was well maintained throughout the period of study. By electron microscopy, additional features of differentiation were seen after 3 weeks, consisting of an increase in size and complexity of microrosettes, to which large numbers of cellular apical profiles contributed. Cilia with variable internal configurations were present. After 4 weeks there was frequent ependymal differentiation along the surface of the explants at their interface with the supporting matrix. Increased gliofibrillogenesis and glycogen rosettes were also evident after 3 weeks in culture. The explants were intensely positive when tested by immunofluorescence for the antigen of the glial fibrillary acidic protein. After 3 weeks in vitro, dense bands of basement membrane material forming complex intercellular finger‐like projections became prominent.
GROWTH AND DEVELOPMENT OF THE BRAIN IN NORMAL AND HEAT‐RETARDED GUINEA‐PIGS
Authors: EDWARDS M. J. , WANNER R. A. , MULLEY R. C.
Published: May 2008

Guinea‐pigs were exposed to a temperature of 41.5–42.5°C for 1h daily on days 20–23 of gestation. Fetuses from control and from heated mothers were studied at 30, 35, 41, 48, 55 and 62 days gestation and post‐natal offspring at 69, 76, 83, 90, 104, 118, 132, 146 and 160 days after conception. Body weights, whole and regional brain weights, and the dry matter, DNA (an index of cellularity) and cholesterol (an index of myelination) contents of these brain regions were measured. There was frequently a small but variable deficit in the body weight of heated offspring. A significant reduction of whole brain weight was found in the heated groups. The deficit in brain weight was detected 7 days after the heat‐stress and remained at about the same relative level until maturity. The DNA and cholesterol concentrations were the same in control and heated brains, but the absolute amounts were less in the latter which resembled proportional, normally shaped miniatures of the control brains. Hyperthermia is known to disrupt cellular proliferations, and since it was given during neurogenesis it is concluded that the size which might be attained by the brain is largely determined by the extent of early neuronal proliferation.
COPPER BINDING AT PNS NODES OF RANVIER DURING DEMYELINATION AND REMYELINATION IN THE PERINEURIAL WINDOW
Authors: BAECQUE CECILE DE , RAINE C. S. , SPENCER P. S.
Published: May 2008

Nodes of Ranvier of peripheral nerves are associated with mucopolysaccharide which is capable of binding a wide variety of cations. The present study has determined the changes in the binding properties of the node of Ranvier during demyelination and remyelination in the perineurial window. The location of copper ion binding, visualized as a dense copper ferrocyanide precipitate, was studied in teased fibres from 60 rat peroneal nerves with single perineurial windows and from 8 normal nerves. In normal nerves, precipitate was present over the nodal axon and at the borders of the paranodal axon. Before demyelination, severely beaded fibres sited within the perineurial window displayed a reduction or a loss of nodal precipitate. During the period of myelin phagocytosis and demyelination, precipitate was absent throughout the denuded axon but present at adjacent, uninvolved nodes. At the commencement of remyelination, precipitate appeared at the newlycreated nodal and paranodal regions and at interfaces between preserved and remyelinating internodes. The density increased with myelin thickening. These findings indicate: (1) severely beaded regions lose their normal binding property before undergoing demyelination, (2) demyelinated regions do not bind copper ions, (3) remyelinating fibres bind copper ions at newly‐created nodes and (4) Schwann cells are responsible for the production of nodal mucopolysaccharides.
TUBULAR BODIES IN ENDOTHELIAL CELLS IN MENINGIOMAS
Authors: OHSUGI T. , HIRANO A.
Published: May 2008

The endothelial cells of small vessels in three cases of meningioma were studied by means of electron microscopy. Unusually large numbers of tubular bodies and associated tubule‐containing vacuoles were found. The constituent tubules seemed identical but the various bodies differed in terms of their size, matrix and the packing of the tubules within them.
THE SEQUENCE OF MYELINATION IN THE EPIRETINAL PORTION OF THE OPTIC NERVE IN THE RABBIT
Authors: NARANG H. K. , WISNIEWSKI H. M.
Published: May 2008

The epiretinal strip in the rabbit's eye starts to develop 8 days after birth, and myelination of its fibres begins at the age of 9–10 days. Myelination reaches its peak between days 15–19 and almost all the fibres are myelinated by day 22. The pattern of myelination is similar to the accepted concept for central myelinogenesis and proceeds disto‐proximally. Litter size seems to influence the time of onset and the speed of myelination. The chronological sequence of myelination is asymmetrical both between the two eyes and between the nasal and temporal sides of the same eye.
GLYCOSAMINOGLYCANS IN ASTROCYTES
Authors: LEWIS P. D. , LAMPERT I. A.
Published: May 2008

By means of the Alcian blue ‘critical electrolyte concentration’ technique and specific enzymic extraction, stainable material corresponding to chondroitin sulphate has been demonstrated in the cytoplasm of reactive astrocytes around a needle wound in the brain of rats, in astrocytic processes in the white matter of the mouse brain after treatment with cuprizone, and in human fetal astrocytes grown in uitro. Increased amounts of glycosaminoglycans in astrocytes seem to accompany rearrangement of tissue components in the central nervous system, and the histochemical demonstration of chondroitin sulphate in astrocytes may reflect changes in the state of their cell surface.
PEROXIDASE ACTIVITY IN THE PAROTID GLAND IN JUVENILE NEURONAL CEROID‐LIPOFUSCINOSIS
Authors: PILZ H. , GOEBEL H. H.
Published: May 2008

The parotid gland of a 17 year old boy who died from juvenile type of neuronal ceroid‐lipofuscinosis contained autofluorescent lipopigments in epithelial and mesenchymal cells that showed the typical curvilinear and fingerprint profiles; these were not mixed with his secretory granules of the epithelial cells. Determination of p‐phenylenediamine‐mediated peroxidase in this tissue under various conditions yieded normal total enzyme activity and isoenzyme pattern. From these findings it is concluded that the pathological changes in this inherited disease cannot be related to a peroxidase deficiency.
TETRAPLOIDY AND BLINDNESS
Authors: SCHOLTZ C. L. , MANN D. M. A.
Published: May 2008

Cells with tetraploid nuclei have been examined in the striate cortex of patients with visual impairment and compared with age and sex matched controls. The number of these nuclei is reduced in those with visual impairment suggesting that tetraploidy is dependent upon an intact visual pathway and may be related to visual experience and memory.
EXPERIMENTAL STUDIES ON THE POSTNATAL DEVELOPMENT OF THE BRAIN. III. CEREBELLAR DEVELOPMENT FOLLOWING LOCALIZED ADMINISTRATION OF ENU
Authors: DAS G. D. , PFAFFENROTH M. J.
Published: May 2008

Experimental studies on the postnatal development of the train. III. Cere‐bellar development following localized administration of ENU

Microquantities of N‐ethyl‐N‐nitrosourea (ENU) were injected directly into the cerebellum of 5 and 10 day old rats. It was found that ENU had cytotoxic effects not only on the mitotically active cells of the external granular layer, but also on the non‐mitotic differentiating neurons, including Purkinje cells. Regeneration of the external granular layer, in part due to initial immigration of cells from the normal neighboring folia followed by mitosis, was found to be related to and followed by the recovery of the surviving Purkinje cells. These findings suggested that (a) disorientation and disorganization of the Purkinje cells were due to the treatment and not to the degenerative and regenerative activities of the external granular layer, and that (b) regeneration and increase in the external granular layer resulted from induction by the surviving Purkinje cells. Although microscopically the cerebellum appeared to have regenerated, macroscopically ENU had left lasting effects. The folia, where the carcinogen was injected, showed an absence of secondary folia, and the cerebellum as a whole was small in size.
THE DEVELOPMENT AND ULTRASTRUCTURE OF THE MICROVASCULATURE IN MALIGNANT GLIOMAS
Authors: WELLER R. O. , FOY M. , COX SUSAN
Published: May 2008

The development and ultrastructure of the microvasculature in malignant gliomas

The ultrastructural features of the small blood vessels in sixteen gliomas and in their zones of infiltration were compared with normal cerebral capillaries. Extensive new blood vessel formation was seen both in the zones of infiltration and within the main tumour. Immature capillaries in the former had a relatively simple structure with a slit‐like lumen containing no blood cells; they resembled capillary buds seen in normal repair tissue and in brain adjacent to a cerebral metastasis. Near areas of necrosis and in pleomorphic regions of gliomas, endothelial cells formed complex, compound immature capillaries with many rudimentary lumina. These appearances are discussed in relation both to the production of tumour angiogenesis factors by gliomas and to the occurrence of gliosarcomas. There was a transition in the structure of the mature capillaries through the zone of tumour infiltration; the vessels gradually changed from normal structure to resemble the capillaries in the main tumour. The endothelial cells became thinner and developed villous processes on the luminal surfaces. Perivascular spaces developed with separation of the glial and capillary basement membranes. Perivascular glial or tumour cell end‐feet were seen even in anaplastic gliomas, but in most tumours they formed an incomplete layer around the vessels. The differences between capillary structure in gliomas and in normal brain are discussed in relation to the alteration in the blood‐brain barrier observed in gliomas.
SUBACUTE NEUROPATHIC EFFECTS OF DIISOPROPYLFLUOROPHOSPHATE AT THE CAT SOLEUS NEUROMUSCULAR JUNCTION
Authors: BAKER T. , GLAZER ELLYN , LOWNDES H. E.
Published: May 2008

Subacute neuropathic effects of diisopropylfluorophosphate at the cat soleus neuromuscular junction

Diisopropylfluorophosphate (DFP), an organophosphate cholinesterase inhibitor, causes a neuromuscular dysfunction 1–3 days after exposure (subacute) as well as a delayed (21 day post‐drug) peripheral neuropathy. The effects of DFP were studied in cats given 2 mg/kg DFP into one femoral artery. The contractile strength of the soleus muscle evoked by indirect, single stimulation was reduced 4 h later and fell to 16% of normal after 3 days; by 7 days post‐drug the contractile strength recovered to 76% of control values. A pre‐junctional neuromuscular defect was investigated by assessing a motor nerve terminal function at 4 h and 1, 3, 5 and 7 days after DFP injection. In untreated control animals 83% of alpha soleus motor axons generated post‐tetanic repetition (PTR) but after DFP the incidence of PTR was 40% at 4 h, 7% at 1 day, 8% at 3 days, 27% at 5 days and 72% at 7 days. Electron micrographs of neuromuscular junctions 3 days after DFP showed severe disruption of end‐plates and a conspicuous reduction in the number of motor nerve terminals. The remaining nerve terminals were retracted from the end‐plate region and were enveloped by Schwann cell processes. Internodal sprouting of soleus axons and post‐junctional alterations were still present at 7 days. The time course of the pre‐junctional defect coincided with, and contributed to, the reported post‐functional necrosis.
ULTRASTRUCTURAL CHANGES IN THE DEVELOPING RAT CEREBELLUM IN CHRONIC UNDERNUTRITION
Authors: YU MANG C. , YU WAN‐HUA AMY
Published: May 2008

Ultrastructural changes in the developing rat cerebellum in chronic under‐nutrition

An ultrastructural study was made of the effects of undernutrition during the first three weeks of postnatal life on the development of the rat cerebellum. Undernutrition was induced in newborn rats (Sprague‐Dawley strain) by increasing the litter size to eighteen pups per dam, versus six pups per dam for the controls. The undernourished rats grew slower and at 22 days of age their average body weight was about 42% of the mean control weight. Electron microscopic examination revealed pronounced and specific changes in the presynaptic terminals and nerve fibers, and in the astrocytes. The synaptic changes were characterized by the presence of membranous whorls of varying densities, and by the accumulation of glycogen particles. Many nerve fibers, myelinated and unmyelinated, showed bizarre configurations of membranous whorls and vesicular profiles in the axoplasm. The myelin sheaths appeared intact. No alterations were observed in the nuclei and perikarya of the Purkinje, granule, basket and stellate cells. Among the neuroglial elements, the Bergmann glia and the astrocytic processes showed large accumulations of glycogen particles. The changes in the presynaptic terminals and axons were interpreted as degenerative, whereas those in the astrocytes as reactive.
QUANTITATIVE HISTOLOGY OF NERVE IN PROTEIN‐CALORIE MALNUTRITION AND WELL‐NOURISHED CHILDREN*
Authors: DASTUR DARAB K. , DEWAN ANITA , MANGHANI DAYA K. , UDANI P.M.
Published: May 2008

Dastur D.K., Dewan A., Manghani D.K. & Udani P.M. (1977) Neuropathology Applied Neurobiology 3, 405–422

Quantitative histology of nerve in protein‐calorie malnutrition and well‐nourished children

Quantitative histological data is presented on the sural nerve from four well‐nourished control children between the ages of 5 months and 10 years. The average myelinated nerve fibre density was 14 460/mm2 with a range of 13 020/mm2 to 15 700/mm2, and bore no relation to chronological age, both the oldest and the youngest, children showing high counts. An age‐related increase in size of myelinated fibres was seen in the histograms to become bimodal at age 1 year and then remained essentially unchanged until 10 years. One well‐nourished 9‐month‐old infant born 2 months preterm showed features suggesting retardation in myelination and nerve fibre growth, medium‐sized nerve fibres (> 5μm) having not yet developed, while the fibre density was greater (17 420/mm2). Quantitative histological data on the sural nerve is also presented in 8 of 14 children with protein‐calorie malnutrition (PCM), varying in age from 1.5 to 9 years, either with protein deficiency (kwashiorkor) predominating or with calorie malnutrition predominating. The majority had acquired some secondary infection as well. Twelve of the fourteen children suffered from severe malnutrition or marasmus (grade III or IV according to Harvard standards). The myelinated nerve fibre densities varied from 7940 to 22 820/mmz with a mean of 16 199/mm2, not significantly different from the mean densities in the four comparable control children. The histograms, however, showed a persistence of small diameter fibres (<5 μm) in children with PCM especially those above 2 years of age, suggesting an arrest of, or delay in, myelination. This arrest, and the frequent paucity of thick axons in silver stained preparations, suggested a lack of development of medium and large myelinated nerve fibres. There was also an inverse relationship betweeen the size of myelinated fibres and the grade of malnutrition as also the age of the patients.