Fall Risk Identification Throughout the Continuum of Care for Elderly Trauma Patients: An Injury Prevention Initiative

INTRODUCTION

Falls are the second leading cause of trauma-related deaths worldwide. Identifying fall risk patients and initiating interventions reduces injuries and mortality, particularly in the elderly. The primary aim of this retrospective study was to identify missed opportunities for fall risk identification and intervention for geriatric trauma patients.

PATIENTS AND METHODS

In this retrospective observational cohort study, the trauma registry was queried to identify geriatric patients admitted for a fall over 36 months. The electronic medical record (EMR) was reviewed to evaluate patients' fall risk in the 12 months prior to the index fall admission. The EMR was also queried for repeat falls within 12 months after discharge, and to determine if fall prevention education was provided at discharge.

RESULTS

597 patients met inclusion criteria; 68.3% were female. 64.7% were at risk for falling in the year before admission. 2% had documented fall prevention education at discharge. 32% of patients fell again within a year of discharge and 19.4% were readmitted for a repeat fall. Patients at high risk for falls (on the Hester-Davis scale) were significantly more likely to be readmitted (p = 0.005) and expire within six months (p = 0.033) than moderate risk patients. Mortality at 12 months post-admission for all patients was 19.4%.

CONCLUSION

This large study demonstrated that geriatric trauma patients admitted for a fall were already at risk for falling in the 12 months prior to admission. This is a novel finding that presents a substantial prevention opportunity for healthcare systems. Education and implementation of proven techniques to prevent falls as soon as at-risk patients are identified has the potential to change the course for a patient who may not only fall, but also fall again. This proactive approach could significantly impact the fall epidemic in our elderly population.

Step up to the Brain Injury Guidelines league: Adoption of Brain Injury Guidelines at a Level III trauma center, A pilot study

Introduction

The Brain Injury Guidelines (BIG) direct surgeons to implement risk-stratified treatment plans for patients with traumatic brain injury (TBI). BIG categorize patients into one of three severity categories, from lowest to highest risk (BIG 1, BIG 2, and BIG 3). BIG empowers physicians to implement standardized treatment plans that limit unnecessary hospitalizations, repeat imaging, and neurosurgical consultation. These guidelines have been studied in Level I trauma centers, but their clinical application has never been studied in a Level III trauma center. In this pilot study, we sought to determine if the BIG can be implemented in a regional trauma center where patients with less severe brain injuries are locally evaluated and treated.

Methods

All TBI patients at a Level III trauma center were stratified using the BIG criteria, where BIG 1 and BIG 2 patients were managed locally and BIG 3 patients were transferred to a Level I trauma center. We conducted a retrospective review using the local trauma database and electronic medical records over a 1-year period when BIG were first protocolized. The primary endpoint included deaths, complications, readmissions, and length of stay.

Results

There were 6 (12.2%) BIG 1, 5 (10.2%) BIG 2, and 38 (77.6%) BIG 3 patients evaluated at the Level III trauma center. All BIG 1 and BIG 2 patients remained at the Level III trauma center, and 33 of the 38 BIG 3 patients were transferred. There were no complications, readmissions, or unexpected transfers within the BIG 1 or BIG 2 patient cohorts.

Conclusion

The BIG criteria can be successfully implemented in a Level III trauma center. A collaborative transfer agreement with a Level I trauma center reduces unnecessary transfers without negatively affecting patient care. The BIG criteria should be considered for well-developed regional trauma systems.

The Ultrastructure and Histopathology of an Acidophil Adenoma of the Canine Adenohypophysis

An acidophil adenoma in a 12-year-old spayed boxer dog resulted in clinical signs related to a space-occupying lesion of the hypophysis. There were two types of acidophils, as determined ultrastructurally, within the adenoma. The predominating type was interpreted to be in the storage phase of the secretory cycle as the cytoplasm was densely granulated and the organelles concerned with protein synthesis and packaging of secretory products were poorly developed. The second, less common type contained few secretory granules, had a well developed endoplasmic reticulum and Golgi apparatus, and was interpreted to be secretorily active. The secretory granules of the neoplastic acidophils were large (420 m μ), uniformly electron-dense, and had a narrow submembranous space. An adenoma of the pancreatic islets was also present.

Primary Neoplasms of the Salivary Glands in Animals Compared to Similar Tumors in Man

Thirty primary salivary tumors of animals (22 in dogs, 4 in horses, 2 in cats, 1 in a baboon and 1 in a guinea pig) were classified according to their histologic and biological characteristics and compared with their counterparts in man. According to criteria used in this report, 3 were classified as mucoepidermoid tumors (1 benign and 2 malignant), 1 as a squamous carcinoma, 5 as benign mixed tumors, 1 as a malignant mixed tumor, 12 as acinic cell tumors, 2 as ductular, 3 as trabecular, 2 as anaplastic adenocarcinomas and 1 as a malignant melanoma. The parotid gland was the site of the neoplasm in 16 cases, the mandibular gland in 5, the sublingual gland in 2 and minor salivary glands in the remaining 7.

Except for the difference in proportional incidence of the various types of salivary neoplasms in animals as compared to man, they are similar in their morphological pattern and in their biological behavior.

Functional Chromophobe Adenomas of the Canine Adenohypophysis

Chromophobe adenomas from 8 dogs with clinical signs and lesions of hyperadrenocorticism (Cushing's-like disease) were selected for electron microscopic study in order to establish a morphologic basis for active secretion by the neoplastic cells. At the level of ultrastructure there was definite evidence of secretory activity and the organelles concerned with protein synthesis (endoplasmic reticulum) and packaging of secretory products (Golgi apparatus) were well developed. Although the numerous secretory granules present varied in electron density and in size, the most frequently encountered granule measured 170 m μ in diameter. The secretory granules of the neoplastic cells differed from those found within acidophils and basophils of the canine hypophysis. Based on these findings it was concluded that the cells comprising these chromophobe adenomas were actively secreting corticotrophs of the pituitary gland.

Neoplasms in the Adenohypophysis of Dogs

Twenty-six neoplasms of the adenohypophysis were classified either as chromophobe adenomas (20 dogs) or adenomas of the pars intermedia (6 dogs). In 62% of the dogs the neoplasms were functionally active (14 chromophobe adenomas, 2 adenomas of the pars intermedia) and associated with a syndrome of hyperadrenocorticism (Cushing's-like disease). The adrenal cortical hypertrophy and hyperplasia, muscular weakness and wasting, leukocytosis with a neutrophilia, eosinopenia and lymphopenia, deposition of fat in the liver, increased serum corticosteroid, and increased urinary 17-hydroxycorticosteroids all suggested the neoplasms were producing ACTH. Mineralization of the lungs and other tissues was consistently present in dogs with functional neoplasms.

Adenomas of the pars intermedia appeared to arise from the lining epithelium of the residual hypophysial lumen covering the infundibular process. They were sharply demarcated from the compressed pars distalis.

A subependymal giant cell astrocytoma in a cat

A 6-year-old spayed female Domestic Shorthair cat presented with a 1 to 2-month history of blindness and altered behavior. At necropsy, a 1-cm-diameter, firm white mass was found arising from the subependymal region of the right lateral ventricular wall that protruded into and partially filled the lumen. Histologically, there was a well-demarcated, expansile paraventricular neoplasm composed of moderately pleomorphic cells within a richly fibrillar matrix arranged in interlacing streams and perivascular pseudorosette-like patterns. Neoplastic cells varied in morphology from small spindloid cells to larger polygonal cells with eccentric vesicular nuclei to neuronlike cells with vesicular nuclei and prominent nucleoli. The mitotic index was low. Immunohistochemically, neoplastic cells were positive for S-100 protein, glial fibrillary acidic protein, and neuron-specific enolase and negative for neurofilament protein. Ultrastructurally, the cells contained few to abundant bundles of intermediate filaments with variable numbers of mitochondria, endoplasmic reticulum, and ribosomes. These features are characteristic of subependymal giant cell astrocytoma (SEGA) in humans. To our knowledge, this is the first reported case of SEGA in domestic animals.

Case report: a nursing challenge, the unstable pelvic fracture

A case report is presented that describes the initial care of a severely injured patient who was hemodynamically unstable. The discussion highlights the process used to recognize life-threatening injuries, to differentiate internal sources of hemorrhage, to provide damage-control surgery, and to stop further bleeding with an interventional radiologic examination. The emergency nursing care of a patient with unstable pelvic trauma is included.

Variation among trauma centers' calculation of Glasgow Coma Scale score: results of a national survey

BACKGROUND

Glasgow Coma Scale (GCS) scoring is enigmatic in intubated patients. To determine if there is consensus among Level I trauma centers, a national telephone survey was conducted.

METHODS

Trauma registrars at state-verified or American College of Surgeons-verified Level I trauma centers were questioned about GCS scoring, recording, and reporting in patients who are intubated or intubated and pharmacologically paralyzed.

RESULTS

Seventy-three centers were contacted. Seventy-one use initial GCS scores for registry recording. Intubated patients are given 1 point for verbal component plus eye and motor scores at 26% of centers and a total GCS score of 3 at 23%; GCS score is estimated with "T" given for verbal component at 16%, scored as unknown at 10%, always scored as 15 at 10%, and the method of scoring is unknown at 15%. Pharmacologically paralyzed intubated patients are given a total GCS score of 3 at 34%, GCS score is estimated with "T" given for verbal component at 18%, patients are given 1 point for verbal component plus eye and motor scores at 12%, scored as unknown at 11%, always scored as 15 at 8%, and the method of scoring is unknown at 16%.

CONCLUSION

Wide variation in GCS scoring among Level I trauma centers was identified. Because GCS scores are used in treatment algorithms, trauma scoring, and outcome prediction (Trauma and Injury Severity Score), uniform scoring is essential and should be pursued. Use of state and national databases and outcome research may be adversely affected by the lack of consistent GCS scoring.

Primitive neuroectodermal tumor in a two-month-old black and white Colobus monkey

A 2-month-old male black and white Colobus monkey (Colobus guereza kikuyuensis) was euthanatized because of progressive physical deterioration, rear limb paralysis, lymphadenopathy, and the presence of facial and retroperitoneal lumbar masses. At necropsy, soft white masses were present in and around lumbar vertebrae, the subcutis of the face, multiple lymph nodes, and the fourth ventricle of the brain. Histologic and immunohistochemical analysis of these masses revealed a primitive neoplasm with both neuronal and glial differentiation, consistent with a primitive neuroectodermal tumor (PNET) with bipotential differentiation. The extracranial tumors were synaptophysin (SYN)-positive, glial fibrillary acidic protein (GFAP)-negative, and neurofilament protein (NFP)-negative, while the intracranial tumor was SYN-positive, GFAP-positive, and NFP-negative.

Esophageal tracheal Combitube in the emergency department

The Combitube is currently being used in some prehospital cardiac arrest situations and in flight programs for management of airways in trauma patients, as well as in inpatient departments with limited availability to personnel experienced in intubation. The Combitube allows for quick intubation and for continuing airway access while the patient is in the emergency department.

Intubation quality assurance thresholds

INTRODUCTION

Quality assurance (QA) and continuous quality improvement (CQI) are valued activities within health-care organizations. Quality assurance indicators as guidelines for quality practice usually are established intuitively. The purpose of this study was to determine an appropriate threshold for successful intubation in patients transported by air and to examine factors impacting this success rate.

SETTING

Fifteen rotor-wing programs from across the United States participated.

METHOD

The study was a prospective descriptive design. A total of 369 flight crew members agreed to participate, and intubations were attempted on 862 patients during the 12-month study.

RESULTS

Intubations were attempted on 862 patients and were successful in 788 (91.4%) of the patients. Of the patients not successfully intubated, 14 received supplemental oxygen only, 25 were supported with bag-valve-mask, 26 received a surgical cricothyroidotomy and for nine patients it was unknown what form of airway support was provided.

CONCLUSION

Factors impacting successful intubation include cardiac arrest, use of neuromuscular blockade, use of sedatives and facial trauma. Data from the study support a threshold for successful intubation of between 90% and 95%.

Radiation effects of boron neutron capture therapy on brain, skin, and eye of rats

PURPOSE

The present study was carried out to evaluate the radiation effects of boron neutron capture therapy (BNCT) on the brain, skin, and eyes of nude rats following systemic administration of boronophenylalanine (BPA) and neutron irradiation to the head.

METHODS AND MATERIALS

A solution containing 120 mg of 10B-enriched-L-BPA complexed with fructose was administered IP to nude rats. Boron concentrations were approximately 8.4, 9.4, 10.0, and 11.0 micrograms/g in the brain, blood, skin, and eyes, respectively, at 6 h when the animals were irradiated at the Brookhaven Medical Research Reactor (BMRR). As determined in a study carried out in parallel with this one, the BNCT radiation doses were sufficient to cause tumor regression in nude rats carrying intracerebral implants of the human melanoma cell line MRA 27.

RESULTS

Mild to moderate increases in loose fibrous tissue were observed in the choroid plexus at estimated physical doses to the brain and blood that ranged from 4.3-7.1 Gy and 4.6-7.7 Gy, respectively, and these appeared to be dose and time dependent. Other changes in the choroid plexus included occasional infiltrates of macrophages and polymorphonuclear leukocytes and vacuolation of epithelial cells. Dose-dependent moist desquamation of the skin was observed in all rats, but this had healed by 28 days following irradiation. Cataracts and keratitis developed in the eyes of most animals, and these were dose dependent.

CONCLUSION

The minimal histopathological changes seen in the brain at doses that were sufficient to eradicate intracerebral melanoma indicates that BNCT has the potential to cure a tumor bearing host without producing the normal brain injury usually associated with conventional external beam radiation therapy. Studies in canines, which currently are in progress, should further define the dose-effect relationships of BNCT on critical neuroanatomic structures within the brain.

Growth inhibition of synchronized trigeminal neurinoma cells by nerve growth factor

Nerve growth factor (NGF) reduces the development of trigeminal neurinomas in vivo. To characterize the action of NGF on these tumors, clonal cells (476-16) isolated from a rat trigeminal neurinoma cell line were synchronized at early S phase by aphidicolin, a reversible inhibitor of DNA polymerase alpha, and effects of NGF on DNA replication were examined in vitro. While NGF did not inhibit DNA replication in the ongoing S phase, it reduced the level of DNA synthesis in the succeeding S phase without altering its timing and duration. The inhibitory action was elicited by a brief exposure to NGF during progression through the preceding S to G1 phases with decreasing effectiveness in the later stage of G1.

Growth inhibition of anaplastic glioma cells by nerve growth factor

Nerve growth factor (NGF) inhibited cellular DNA synthesis of rat T9 anaplastic glioma cells in a dose-dependent manner in the range of 0.5-5 micrograms/ml. Oxidation of 2 to 3 tryptophan residues of NGF, which had been known to destroy biological and immunological activity, greatly diminished its inhibitory effect on DNA synthesis. The inhibition was also abolished by anti-NGF IgG. Flow cytometric analyses and immunocytochemical assays of DNA synthesis using bromodeoxyuridine incorporation at various times during cell exposure to NGF revealed that the growth inhibition was attributable to gradual accumulation of growth-arrested cells at the G1 phase. Synthesis of nuclear regulatory proteins JUN and p53 was inhibited preferentially and progressively by NGF as inhibition of DNA synthesis increased.

The use of nerve growth factor as a reverse transforming agent for the treatment of neurogenic tumors: in vivo results

The rationale behind the evaluation of natural differentiating agents, such as nerve growth factor (NGF), for reverse transforming potential is based on the theory that such compounds may represent a nontoxic means of controlling tumor growth. Previous in vitro experiments have shown that NGF is capable of retarding growth and of inducing persistent differentiation of neurogenic tumor cell lines. In vivo, NGF is capable of causing a persistent reduction in the number of ethylnitrosourea-induced neurinomas and of increasing survival time following intracerebral implantation of F98 anaplastic glioma cells. In this study, anaplastic glioma and neurinoma implants were treated with NGF to evaluate the reverse transforming potential of NGF in vivo. Results indicate that NGF is capable of causing a significant decrease in the growth rate of subcutaneous T9 (anaplastic glioma) and clone 16 (anaplastic neurinoma) implants. Significantly, NGF treatment was accompanied by adverse effects that were minimal and transient. Continued tumor growth (although greatly retarded) following NGF treatment is an aspect that requires further investigation. However, the results of this study suggest that NGF may prove useful, alone or in combination with other types of therapy, for the treatment of tumors of neurogenic origin.

The reverse transforming effects of nerve growth factor on five human neurogenic tumor cell lines: in vitro results

The role of nerve growth factor (NGF) in the development, maintenance and regeneration of the mammalian sensory and sympathetic nervous systems has been well characterized, as has the ability of NGF to induce a variety of neoplastic cell lines of neuroecto-dermal (neurogenic) origin to differentiate. The ability to stimulate neoplastic cells of neurogenic origin to differentiate suggests that NGF may prove useful as a reverse transforming agent for the treatment of neurogenic tumors. Five human neurogenic tumor cell lines were evaluated for their response to NGF in vitro to determine whether the NGF is capable of inducing changes consistent with a reverse transforming response. Results indicate that NGF was able to reverse some of the transformed properties of these tumor cell lines, as NGF treatment stimulated neoplastic cells to develop a more differentiated phenotype, diminished or arrested growth, and induced changes that were persistent.

ENU-induced in vitro neoplastic transformation of rat mammary epithelial cells

Normal mammary epithelial cells, originating from female Sprague-Dawley rats, were grown in Dulbecco's Modified Eagles Medium containing 25% horse serum and hormone supplements. Once established as an epithelial cell culture, the cells were treated with N-ethyl-N-nitrosourea (ENU) in various doses (25-500 ug/ml) to study the process of in vitro mammary epithelial cell neoplastic transformation. The ENU-treatment of primary mammary epithelial cell culture resulted in a sequence of phenotypic changes, termed stages I-V. The rat mammary epithelial cells, after a period of approximately 30 days post-ENU exposure, showed a marked proliferation of morphologically altered cells which formed multi-layered colonies. Subsequently, these cells acquired the capacity to form colonies in soft agar and eventually produced a high yield of palpable tumors when inoculated into newborn female isologous hosts or female athymic nude mice. The immediate effect of ENU on these cells was monitored by measurement of cellular DNA content, unscheduled DNA synthesis, cell proliferation and chromosomal aberrations. The ENU effect on cell proliferation and DNA synthesis was dose dependent; doses greater than 100 ug/ml reduced the cell number and DNA synthesis. Cytofluorometric histograms of non-ENU-treated rat mammary epithelial cells showed a near diploid population of cells. The ENU exposed cells subsequently became hyperdiploid (24-72 hours after ENU) and then regained their near diploid pattern at 120 hours after ENU exposure. The ENU-treated cells also showed a second peak of cells with DNA content in the tetraploid and octaploid range at 24-72 hours after ENU exposure. Single chromatid breaks, isochromatid breaks, chromosomal exchanges, multiple chromosomal breaks and double minutes were among the chromosomal aberrations seen in ENU-treated cells. Most of the chromosomal aberrations peaked at 6 hours post-ENU exposure. The ENU-induced model of in vitro meplastic transformation of rat mammary epithelium as described in this communication appears to provide a good model for the systematic study of the early critical cellular events prerequisite to this carcinogenic process.

Chronic toxicity and oncogenicity of inhaled methyl acrylate and n-butyl acrylate in Sprague-Dawley rats

No exposure-related clinical signs or lesions of systemic toxicity and no oncogenic responses were observed in male and female Sprague-Dawley rats exposed by inhalation to methyl acrylate (MA) or n-butyl acrylate (BA) vapours, at concentrations of 0, 15, 45 and 135 ppm. The rats were whole-body-exposed 6 hr/day, 5 days/wk, for 24 consecutive months. There was a 6-month post-exposure observation period for subgroups of BA-exposed rats. Atrophy of the neurogenic epithelial cells and hyperplasia of reserve cells were observed in the nasal mucosa of all MA- and BA-exposed groups. These changes were dose related and mainly affected the anterior part of the olfactory epithelium. Opacity and neovascularization of the cornea were seen in all MA-exposed groups and in the group exposed to 135 ppm BA. These toxic effects of the olfactory epithelium and cornea were attributed to the known irritancy of MA and BA. In the BA subgroups kept for a 6-month post-exposure observation, reconstructive effects, such as replacement of altered olfactory epithelium with respiratory epithelium, and partial regression of corneal neovascularization were observed.

Repeated transplacental transmission of Neospora caninum in dogs

Four litters of German Shorthaired Pointers from one owner developed a toxoplasmosis-like illness. According to the records, 29 of 39 dogs had hind limb paralysis. Six dogs from 2 litters were necropsied and had generalized encephalomyelitis. Tachyzoites and tissue cysts of Neospora caninum were found in the brain and spinal cord of each dog. Lesions were found in the eyes, extraocular muscles, or both in all of the dogs, and N caninum was detected microscopically in the eyes (retina and choroid in 1 dog), extraocular muscles, or both in 5 of the 6 dogs. Ocular lesions consisted of focal retinitis, choroiditis, mild nonspecific iridocyclitis, and myositis of extraocular muscles. Organisms stained with anti-N caninum serum, but not with anti-Toxoplasma gondii serum in an immunohistochemical test, except in 1 dog. In one dog, aged thick-walled N caninum tissue cysts reacted mildly with anti-T gondii serum.

Immunohistochemical characterization of rat central and peripheral nerve tumors induced by ethylnitrosourea

Ethylnitrosourea-induced central and peripheral nerve tumors in Sprague-Dawley rats were tested for GFAP (Glial Fibrillary Acidic Protein), S-100 protein, NSE (Neuron Specific Enolase) and Anti-Leu 7 (HNK-1) immunoreactivity utilizing the ABC method (avidin-biotin-complex) for GFAP, S-100 protein and NSE, and the PAP method (peroxidase-antiperoxidase) for Anti-Leu 7. Peripheral nerve neurinomas were consistently positive for S-100 protein and consistently negative for GFAP and Anti-Leu 7. Neurinomas would occasionally exhibit positive staining for NSE (2 of 55 tumors). The staining intensity for S-100 protein varied from strongly positive in differentiated neurinomas to weakly positive in anaplastic tumors. Neoplastic and reactive astrocytes exhibited positive staining for both S-100 protein and GFAP. Variation in the GFAP staining intensity of glial tumors correlated with the degree of differentiation as anaplastic tumors did not stain with the same intensity as their more differentiated counterparts. Oligodendrogliomas exhibited occasional immunoreactivity to S-100 protein (3 of 36 tumors). NSE reactivity in oligodendrogliomas was rarely observed (1 tumor in 36) and immunoreactivity against GFAP or Anti-Leu 7 was consistently absent. Anti-Leu 7 and NSE proved to be of little value in the classification of ENU-induced neural tumors.

Characterization of N-nitrosourea-induced tumors of the nervous system; their prospective value for studies of neurocarcinogenesis and brain tumor therapy

Two decades of research with resorptive neurocarcinogens firmly established the high potency of methyl and ethylnitrosourea (MNU and ENU) as neurocarcinogens, particularly in rats. There are significant differences in susceptibility to these agents among species. There are also differences among age groups. Fetuses are between 50 to 100 times more susceptible than adult rats. One single iv inoculation of 20-50 mg/kg ENU into pregnant rats may produce neurogenic tumors in 100% of the offspring. The tumors produced by these compounds have been well characterized morphologically, biologically, biochemically and histochemically. Tumors produced by both compounds are mostly gliomas and neurinomas (Schwannomas), however, clear differences exist between ENU and MNU produced neoplasms. Transplacental exposure to ENU generally results in a high number of anaplastic neurinomas and mostly differentiated gliomas (astrocytomas, oligodendrogliomas or mixed gliomas). In contrast, multiple exposures of adult rats to MNU result in a moderate number of mostly differentiated neurinomas and a high number of anaplastic gliomas. Tumors usually start out as well differentiated oligodendrogliomas or astrocytomas. As they grow larger, they become more mixed and anaplastic. In contrast to spontaneous gliomas in old rats, MNU and ENU-induced astrocytomas can be readily identified with well established biomarkers such as the S100 protein and particularly GFAP (glial fibrillary acidic protein). Neurinomas are also strongly positive for S100 protein. No reliable markers exist for oligodendrogliomas. Neurogenic tumors induced by MNU or ENU, as well as derived cell lines and clones from such tumors, have been successfully used as models for neurocarcinogenesis and therapeutic screening.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of nerve growth factor on the transplacental induction of neurinomas by ethylnitrosourea in Sprague-Dawley rats

Administration of nerve growth factor (NGF) to the offspring of Sprague-Dawley rats transplacentally exposed to 50 mg/kg ethylnitrosourea on the 20th day of gestation resulted in a significant reduction of trigeminal and peripheral nerve neurinomas. Forty, 60, and 80 micrograms of NGF was administered in five s.c. doses, one dose on each of days 12-16, 90-94, and 210-214 postnatally. Of the 34 rats in the NGF-treated group, 11 animals were affected with trigeminal nerve neurinomas as compared to 18/34 in the NGF-untreated group (P less than 0.05). In the peripheral nerves (spinal cord nerve roots) there were five and 11 neurinomas, respectively, in each group of 34 rats. When the total numbers of neurinomas (trigeminal and peripheral nerves) between these groups were compared (16/34 versus 29/34), the significance of neurinoma reduction was P less than 0.01. Five trigeminal and two peripheral neurinomas in the NGF-untreated group were shown by immunohistochemical staining to contain nerve growth factor receptor protein, whereas none of the neurinomas in the NGF-treated group were positive for the receptor protein. The results obtained from this experiment lend support to the hypothesis that NGF has the capability to reduce the oncogenic consequences of ethylnitrosourea exposure perhaps by the process of maturation and/or differentiation of the transformed cells, and that this effect may depend upon the presence of receptor binding sites.

Chemical control of growth and morphological characteristics of anaplastic glioma cells

Nerve growth factor (NGF) and glia maturation factor (GMF) reverse some of the transformed characteristics of T9 glioma cells (Marushige et al., Cancer Res 47: 4109-4115, 1987). As an attempt to define the mechanisms of such actions, various chemical agents which modulate second messenger systems were examined for their effects on growth and morphological characteristics of these cells. Administration of bromo-cAMP, forskolin and methylisobutylxanthine retarded cell growth and induced formation of long, branching processes which were similar to those induced by GMF. Perturbation of Ca2(+)-mediated processes by a Ca2+ ionophore, ionomycin, and by calmodulin antagonists, chlorpromazine and W-7, on the other hand, arrested cell growth, and caused clustering of cells, spreading of the cytoplasm and development of lamellipodium-like protrusions which were reminiscent of the effects of NGF. Administration of bromo-cAMP in combination with chlorpromazine, W-7 or ionomycin prevented spreading of the cytoplasm and produced compact cell bodies with well-developed processes. The results of this study demonstrate that modulation of specific second messenger systems by chemical agents are capable of simulating selective morphological changes inducible by NGF and GMF.

Neuropathology of canine epilepsy

Canine epilepsy can be classified into primary (idiopathic) and secondary (symptomatic) epilepsy, which is similar to human epilepsy. Primary epilepsy in both species is inherited and characterized by the absence of recognizable causative lesions. Secondary epilepsy is linked to a variety of lesions such as brain tumors, trauma, encephalitis, lysosomal storage diseases, congenital malformations, and metabolic-toxic injury. Correspondingly, various subtypes of secondary epilepsy have been recognized. The pathogenesis of secondary epilepsy is basically associated with selective loss of inhibitory neurons that disturbs the balance between excitation and inhibition.

Cytoskeletal reorganization induced by nerve growth factor and glia maturation factor in anaplastic glioma cells

Changes in cytoskeletal organization in T9 anaplastic glioma cells have been examined during morphological changes induced by nerve growth factor (NGF) and by glia maturation factor (GMF). Indirect immunofluorescent labeling of cytoskeletal proteins has revealed that while neither GMF nor NGF induces expression of glial fibrillary acidic protein in this cell line, changes in cytoskeletal organization induced by these factors show some features similar to those observable during maturation of normal glial cells. Changing cell shapes induced by these factors are clearly outlined by the prominent distribution of microfilaments along cellular margins. Microtubules and intermediate filaments gradually extend during morphological changes and fill the characteristic cytoplasmic processes induced by NGF and GMF.

A quantitative morphological assessment of the effect of lidoflazine and deferoxamine therapy on global brain ischaemia

The effect of the combination of two drugs, i.e. lidoflazine (a calcium antagonist), and deferoxamine (an iron chelator) was evaluated following 15 min global brain ischaemia (GBI) and reperfusion in dogs in a randomized blind study. GBI was produced by complete cardiac arrest of 15 min duration. Histopathological analysis performed on in situ fixed brains 40 h post-resuscitation revealed diffuse microhaemorrhages in the control group. These were noted rarely in the treatment group, the mean value of foci of microhaemorrhages/20 low power fields (LPF) being 5.2 in the treatment group versus 28 in the control group (p less than 0.001). Diffuse coagulative necrosis of neurons (ischaemic cell change) in the cerebral cortex, especially lamina 3, hippocampus, striatum, brain stem and cerebellum was present in all cases. Quantitation of the degree of cellular damage obtained by counting the number of anoxic neurons (in consistent regions of the brain) with the use of an image analysis system, revealed no significant difference between the 2 groups. The mean percentages of the ischaemic neurons in the control group in the various areas studied were: parietal cortex, 22.25; hippocampus, 50.37 and cerebellum (Purkinje cells), 66.75; and in the treatment group 25.3, 55.04 and 70.6 respectively. Thus, the lidoflazine-deferoxamine regimen significantly reduced the incidence of microhaemorrhages in the brain, but it did not have any protective effect against anoxic neuronal injury 40 h post-ischaemia in this experimental model of GBI of 15 min duration.

Dieldrin inhibition of gap junctional intercellular communication in rat glial cells as measured by the fluorescence photobleaching and scrape loading/dye transfer assays

Application of the fluorescence-recovery after photobleaching (FRAP analysis) technique and scrape loading/dye transfer assay was made to measure the presence of gap junctional communication in primary rat glial cells in vitro in the presence and absence of the neurotoxicant and tumor promoter dieldrin, a chlorinated insecticide. Results demonstrate that primary rat glial cells are able to exhibit gap junctional intercellular communication and that dieldrin at noncytotoxic concentrations can modulate gap junctional communication as early as 10 min after exposure to the chemical and that the effect is reversible after 4 hr recovery from the dieldrin exposure. Both the FRAP analysis and the scrape loading/dye transfer assay have validated the observation that dieldrin inhibits gap junctional communication in other cell types using different techniques to measure gap junction function. These results were interpreted as an indication that inhibition of gap junctional communication might contribute to the cellular mechanism of dieldrin's neurotoxicity.

Cerebral endothelial microvilli following global brain ischemia in dogs

Cerebral blood vessels (BVs) of dogs subjected to global brain ischemia by complete cardiac arrest of 15 min followed by 8 h of reperfusion, were studied in neocortex and hippocampus by means of transmission electron microscopy. Widespread endothelial microvilli were present in the postischemic animals. The number of endothelial microvilli in the postischemic animals (mean/BV in the neocortex = 3.26 and in the hippocampus = 2.54) was significantly larger than that in the non-ischemic controls (mean/BV in the neocortex = 1.39 and in the hippocampus = 0.84), P for both regions being less than 0.05. Arterioles, venules and capillaries, all were equally affected. Endothelial pinocytotic vesicles were also observed frequently in the postischemic dogs. Marked pericapillary swelling of astrocytic foot processes was present in the surrounding neuropil. It is concluded that the prominent cerebral endothelial microvilli recognized after 8 h of reperfusion following cardiac arrest in this experimental model of global brain ischemia, may play a significant role in the development of delayed postischemic hypoperfusion.

Modulation of growth and of morphological characteristics in glioma cells by nerve growth factor and glia maturation factor

Anaplastic glioma T9 cells were treated with either nerve growth factor (NGF) or glia maturation factor (GMF) or both. It was found that, when T9 cells were treated with these factors in a chemically defined medium, both NGF and GMF induced characteristic changes of cell morphology and growth pattern. Several differences in the effects of NGF and GMF were noted. NGF retarded growth rate, whereas GMF did not. The cells treated with NGF were characterized by a flattened extended cytoplasm with numerous protruding processes. The cell masses were somatically connected by cell bridges. GMF, on the other hand, produced slender cells with long, branching processes forming an interconnecting cell net. Concomitant administration of NGF and GMF retarded cell growth as was demonstrated with NGF alone and induced morphological changes predominantly attributable to GMF. The maximal effect of either NGF or GMF or both was attained after 4 days of treatment. A withdrawal of the factors from the medium following various periods of treatment revealed that the effects of GMF were readily reversible while morphological changes induced by NGF persisted in its absence.

Effect of flunarizine on global brain ischemia in the dog: a quantitative morphologic assessment

The effects of flunarizine, a calcium antagonist, were evaluated in an experimental model of global brain ischemia produced by 15 min of cardiac arrest followed by resuscitation and reperfusion. One group of dogs received flunarizine (0.1 mg/kg intravenously during a 10-min period) at the onset of resuscitation. Another group of dogs underwent cardiac arrest, resuscitation, and reperfusion but did not receive flunarizine. A third group served as nonischemic control. In situ-fixed brains of all animals (nonischemic controls and the postischemic dogs after 8 h of reperfusion) were examined for anoxic ischemic injury. Quantitation of the ischemic neurons was carried out in parietal cortex, hippocampus, and cerebellum by using an image analysis system. Significant difference in the number of necrotic neurons between the flunarizine-treated group and the ischemic controls was noted in the hippocampus only; the mean percentage of necrotic neurons in the two groups being 14.8 +/- 9.6 and 29.3 +/- 12.1, respectively (P less than 0.05). These results indicate that flunarizine has an ameliorating effect on neuronal injury in the hippocampus that follows cardiac arrest in this experimental model of global brain ischemia. However, flunarizine was not found to be effective in reducing the ischemic neuronal damage in the cortex or the cerebellum.

Ultrastructural and ionic studies in global ischemic dog brain

A time course of tissue ionic changes, and their relation to ultrastructural findings during reperfusion following a 15-min global ischemic brain insult was studied in a dog model. Parietal cortex was analyzed for Ca, Na, K, Mg and Fe in controls and after 10 min, 2, 4, and 8 h of reperfusion. After 8 h of reperfusion, the mean values (mumol/g tissue wet wt.) for Ca (control = 1.43, 8 h = 2.76) and Na (control 60.4, 8 h = 107.4) doubled and K (control = 90.4, 8 h = 48.5) decreased to half that of the control. Ultrastructural studies and subcellular localization of calcium in parietal cortex of in situ-fixed brains after 8 h showed cortical neurons with clumping of nuclear chromatin, dilatation of endoplasmic reticulum and disruption of plasma membranes. Large amounts of electron-dense precipitates of calcium were present within dilated astrocytic processes, synaptic vesicles, cytoplasm of edematous dendrites and mitochondria. Cortical neurons from postischemic dogs without reperfusion showed only slight chromatin clumping and edema of astrocytic processes, but no calcium accumulation. The large ionic shifts noted between 4 and 8 h of reperfusion, indicate a progressive inability of the cells to maintain normal transmembrane gradients of these ions and may reflect a membrane destructive process, as demonstrated ultrastructurally at 8 h. Enhanced calcium entry into the neuron during reperfusion appears to be a part of the cytotoxic mechanism leading to neuronal necrosis.

The brain-tumour issue in long-term toxicity studies in rats

Problems arise in the measurement of the neurocarcinogenic potential of chemical substances in chronic toxicity studies because of the spontaneous occurrence of neoplasms in the brain and other organs of rats from the age of about 2 yr. Statistical analysis may be equivocal and must be accompanied by a thorough biological analysis, to determine the presence or absence of the following characteristic effects of neurocarcinogenic agents: a reliable and consistent increase in brain-tumour incidence beyond the expected control level, a decrease in the age at which tumours appear and/or in survival, a dose-effect relationship, a greater effect on embryonal and foetal brain cells than on those of adults, a shift to more anaplastic types of tumour and the finding of preneoplastic lesions. These criteria have been met in chronic tests on the neurocarcinogens ethyl- and methylnitrosourea and some have been met in results obtained with the weak carcinogen methyl methanesulphonate. However, none of these criteria were met in the case of a test compound subjected to two 2-yr studies (one involving transplacental exposure), although brain tumours occurred in the controls and in all the experimental groups. The test substance is not considered to be a neurocarcinogenic agent.

DNA damage, repair, replication, and tumor incidence in the BDIV rat strain following administration of N-ethyl-N-nitrosourea

Berlin-Druckrey (BD-IV) rats were used to evaluate the level of neoplastic transformation, initiation of DNA damage and repair following treatment with N-ethyl-N-nitrosourea (ENU). ENU, a potent neurocarcinogen in the Sprague-Dawley (CD) and BDIX rat strains, was a less potent neurocarcinogen when administered to 30 day old BDIV rats. ENU induced significantly higher levels of tumors of the nervous system, kidney, and liver in CD rats than in BDIV rats. Initial DNA damage was determined by quantitating and comparing the number of alkaline labile sites (ALS) and alkylation of [14C]ENU to deoxyguanosine in the brain, kidney, and liver of BDIV rats. A smaller percentage of ALS were lost from the DNA of the brain (10-15%) than from the kidney (19-27%) and liver (30%). Similarly, loss of 0(6)-ethylguanine was greatest in liver (100%), next in kidney (73%), and least in brain (23%) DNA during a seven-day period. Loss of N7-ethylguanine ranged between 23-44%. These levels of repair are similar to those previously observed in the more sensitive Sprague-Dawley rat. Cellular replication was highest in the liver and lowest in the brain of BDIV rats at 30 days of age and was inhibited to varying extents in all three tissues by ENU. These data indicate, that while there is a good correlation between organ sensitivity to ENU induced carcinogenesis and the persistence of DNA lesions and levels of DNA replication in the same strain of rat, there is no correlation across strains with different carcinogenic potential.

Testicular (Sertoli's cell)-like tumors of the ovary induced by N-ethyl-N-nitrosourea (ENU) in rats

N-ethyl-N-nitrosourea (ENU) administered intraperitoneally or transplacentally to Sprague-Dawley (CD) and BD-IV (Berlin Druckrey IV) rats increased the incidence (26.6%) of an uncommon ovarian tumor with testicular characteristics compared either to controls (3.0%) or rats administered diethylnitrosamine (3.3%). The induced tumors were composed of tubular structures that resembled seminiferous tubules lined by Sertoli's-like cells. The abundant electron-lucent cytoplasm of the tumor cells contained polyribosomes, lipid bodies, and mitochondria but few additional organelles. Sertoli's cell-like tumors appeared to develop from the ovarian stroma in the hilar region of the ovary. They usually were benign and resulted in unilateral enlargement of the ovary. The mean serum concentrations of testosterone, estrone, and estradiol in selected rats with ovarian tumors were elevated above mean serum values in controls. There was not a consistent direct correlation between tumor diameter and circulating hormone level. Ethyl nitrosourea-induced ovarian tumors composed of testicular (Sertoli's-like) cells will provide a reproducible animal model to investigate the histogenesis and hormone secreting properties of this unique gonadal neoplasm.

Characteristics of normal rat mammary epithelial cells and N-ethyl-N-nitrosourea-induced mammary adenocarcinoma cells grown in culture

The characteristics of normal mammary epithelial cells derived from Lewis and Sprague-Dawley rats and N-Ethyl-N-Nitrosourea (ENU)-induced mammary gland adenocarcinoma cells derived from Sprague-Dawley (CD) and Fisher (CDF) rats and grown in culture were compared. After collagenase treatment, the rat mammary epithelial cell aggregates were placed in a hormone-supplemented medium. The normal mammary epithelial cells (NE) attached to the surface of the dish within 50 hours, whereas the mammary adenocarcinoma cells (MA) attached within 24 hours and grew as cell multilayers. After the colonies of NE and MA cells became confluent, the culture system entered a steady state in which the cells from the upper layer were shed into the medium. The rate of proliferation and squame detachment in confluent cultures was increased by the presence of epidermal growth factor (EGF). Rhodanile blue staining and transmission electron microscopy showed that the shed cells were partially keratinized. In addition, cultured MA (but not normal) cells were able to grow in soft agar and form tumors when inoculated into appropriate hosts. The opposite was true in each case for the mammary adenocarcinoma cells. Karyotypes of normal and neoplastic rat epithelial cells revealed a hypodiploid modal number of chromosomes.

Chronic toxicity/carcinogenicity study of FD & C Blue No. 2 in rats

FD & C Blue No. 2 was fed to rats in the diet in a long-term toxicity/carcinogenicity study. The study included an in utero phase in which the compound was administered to groups of 60 male and 60 female Charles River CD albino rats at levels of 0.5, 1.0 and 2.0%. Two concurrent control groups, each containing 60 rats of each sex, received the basal diet. After random selection of the F1 animals, the long-term phase was initiated at the same dietary levels, with 70 rats of each sex in each dose group and in each of two control groups. Maximum exposure was 30 months. No consistent compound-related biologically adverse effects were noted. There were random statistically significant differences from the controls with respect to body weight, food consumption and clinical chemistry tests. Food consumption by the test groups showed a dose-related increase. This was probably due to the non-nutritive character of the colouring. A statistically significant increase in gliomas in the high-dose male rats was not found to be biologically significant, since none of the criteria for determining the neurocarcinogenic potential of chemical substances was met. The overall brain-tumour incidence in this study was within the range typical for 2-yr-old CD rats. Under the conditions of this study, FD & C Blue No. 2 did not produce evidence of any toxicity, including carcinogenicity.

Prognostic role of cell morphology of animal tumors

The purpose of this presentation is to determine the prognostic role of cellular morphology in animal neoplasia. With some exceptions, cellular morphology is the single most accurate predictor of the prospective behavior of neoplasms. There is generally a positive correlation between the degree of malignancy and prognosis. The exceptions are a) morphologically malignant-appearing tumors following a benign course (e.g., canine histiocytoma, canine seminoma, equine sarcoid) and b) morphologically differentiated tumors exhibiting an unpredictable prognosis (e.g., canine pericytoma, acanthomatous epulis, myxoma, follicular thyroid cell carcinoma, etc.). Anaplasia, an important characteristic of most malignant neoplasms, may be less stable than generally assumed. Sodium butyrate may reverse it intermittently and anaplastic gliomas may loose all morphologic and cytokinetic characteristics of anaplasia following sodium butyrate exposure. Host factors, such as nerve growth factor, have similar and more lasting effects upon anaplastic cells derived from the neural crest. Such factors may act as reverse transformation agents and may represent prospective therapeutic agents for anaplastic tumors.

Spinal cord medulloepithelioma in a dog

Medulloepithelioma, an embryonal neural tumor, was diagnosed in a 6-month-old Bullmastiff. Clinical signs of incomplete, upper motor neuron, transverse myelopathy involving the hindlimbs were observed on examination. Myelography was required to identify the cause of clinical abnormality. The tumor involved the L1 spinal cord segment.

Diverse spectrum of tumors in male Sprague-Dawley rats following single high doses of N-ethyl-N-nitrosourea (ENU)

In this study, 30-day-old male Sprague-Dawley rats, were inoculated intraperitoneally with a single dose of 45, 90, and 180 mg/kg of N-ethyl-N-Nitrosourea (ENU). A wide spectrum of neoplasms occurred. The most common tumors were those of the mammary gland and of the nervous system. Although the incidence of mammary tumors was highest in the two high-dose groups (90 and 180 mg/kg ENU), the incidence of neurogenic tumors was highest in the 45 mg/kg dose group. Mammary tumor development led to early death and precluded development of tumors of the nervous system, which require a longer latency period. A variety of neoplasms of other organs have been associated particularly with high doses of ENU, including ameloblastic tumors, carcinomas of the thyroid, prostate, kidney, pancreas, intestine, and lung, hemilymphatic tumors, and sarcomas. It is concluded that large doses of ENU are capable of expanding the tumor spectrum in young male rats beyond the target organs generally affected with lower doses, as described in earlier reports.

Neoplasms induced with high single doses of N-ethyl-N-nitrosourea in 30-day-old Sprague-Dawley rats, with special emphasis on mammary neoplasia

Intraperitoneal administration of high doses (45, 90, and 180 mg/kg of ENU (N-ethyl-N-nitrosourea) to 30-day-old female Sprague-Dawley (CD) rats resulted in a high incidence (greater than 100%) of mammary tumors (MT), of which 95% were malignant. The mean induction time was 92 days for the high dose group. There was a definite dose-effect relationship. As the dose of ENU decreased the number of rats affected and number of tumors per rat decreased, but the survival time and mean induction time increased. At the time of death 7.5% of mammary tumors had metastasized to the lung. A variety of histological MT types were produced simulating breast tumors in women. In addition to MT, a number of rats developed primary tumors in other organs (brain, ovary, kidney, and hemic-lymphatic system). The high MT incidence, high rate of malignancy, short latent period, and the simulation of human breast tumor types suggest this experimental design to be a valuable animal model to study initiation, hormone dependency, and pathogenesis of mammary neoplasia.

The effect of nerve growth factor and antibodies to nerve growth factor on ethylnitrosourea-induced neoplastic proliferation in rat trigeminal nerves

Sprague-Dawley (CD) rats were injected intravenously with ethylnitrosourea at a dose of 20 mg/kg on day 20 of gestation. This exposure resulted in early neoplastic proliferation or development of a neurinoma of the trigeminal nerve in 58% of the offspring at 90 days of age. Implantation of osmotic microinfusion pumps containing 2.5S nerve growth factor prior to ethylnitrosourea administration significantly reduced the incidence of early neoplastic proliferation. Postnatal implantation of microinfusion pumps containing 2.5S nerve growth factor also resulted in a significant but less pronounced reduction of early neoplastic proliferation. Immunoglobulin G directed against nerve growth factor (anti-nerve growth factor) did not influence the incidence of early neoplastic proliferation when administered via microinfusion pumps implanted on day 15 postnatally. These findings suggest that nerve growth factor has a protective effect on the developing nervous system against ethylnitrosourea-induced carcinogenesis.