Baylisascaris procyonis infection in white-footed mice: predicting patterns of infection from landscape habitat attributes.

There is a growing body of evidence that habitat fragmentation resulting from anthropogenic land use can alter the transmission dynamics of infectious disease. Baylisascaris procyonis , a parasitic roundworm with the ability to cause fatal central nervous system disease in many mammals, including humans, is a zoonotic threat, and research suggests that parasite recruitment rates by intermediate hosts are highly variable among forest patches in fragmented landscapes. During 2008, we sampled 353 white-footed mice ( Peromyscus leucopus ) from 22 forest patches distributed throughout a fragmented agricultural ecosystem to determine the influence of landscape-level habitat attributes on infection rates of B. procyonis in mice. We characterized each mouse in terms of infection status and intensity of infection, and calculated (on a patch-wide basis) prevalence, mean abundance of B. procyonis , and mean intensity of infection. We used an information-theoretic approach to develop a suite of candidate models characterizing the influence of landscape attributes on each of our measured characteristics of B. procyonis infection in white-footed mice, based on previous knowledge of raccoon ( Procyon lotor ) ecology and B. procyonis distribution in agricultural ecosystems. We observed evidence of B. procyonis infection in mice across all 22 habitat patches sampled. However, parasite recruitment rates and intensity were highly variable among patches, and the results of our analyses suggest that spatial variability in B. procyonis infections was primarily driven by emergent properties of fragmented ecosystems. In particular, prevalence, abundance, and intensity of B. procyonis infections in mice were negatively associated with the size and connectivity of forest patches. These results support previous studies indicating that habitat fragmentation can alter the transmission dynamics of infectious disease, and suggest that factors below the scale of landscape, i.e., fine-scale habitat structure or demographic and behavioral attributes of intermediate and/or definitive hosts, also may be important for predicting patterns of B. procyonis infection in intermediate hosts.

Implications of raccoon latrines in the epizootiology of baylisascariasis.

Raccoons (Procyon lotor) frequently establish defecation sites, termed latrines, on large logs, stumps, rocks, and other horizontally oriented structures/surfaces. These latrines are important foci of infective eggs of Baylisascaris procyonis, a nematode parasite of raccoons which is pathogenic to numerous species of mammals and birds. To examine the role of raccoon latrines in this animal-parasite interaction, we documented animal visitations to raccoon latrines in two large forested tracts and two woodlots in Indiana (USA) during 1994 and 1995. Species richness of vertebrate visitors did not differ between sites or years, but species composition differed by site and year. Fourteen mammal and 15 bird species were documented visiting raccoon latrines. Small granivorous mammals, including white-footed mice (Peromyscus leucopus), eastern chipmunks (Tamias striatus), and tree squirrels (Sciurus carolinensis, S. niger, Tamiasciurus hudsonicus) were the most common visitors to latrine sites. White-footed mice, chipmunks, white-breasted nuthatches (Sitta carolinensis), and opossums (Didelphis virginiana) were photographed foraging on undigested seeds in raccoon feces. Active foraging at latrines also was shown experimentally; seeds embedded in raccoon feces were removed at a greater rate at latrine sites than at nonlatrines. We conclude that raccoon latrines are visited routinely by a variety of vertebrates, especially small granivorous rodents and birds which forage for seeds in raccoon feces, and that raccoon latrines are probable sites of transmission of B. procyonis to susceptible mammals and birds.

Primary cerebral leiomyosarcoma.

A case of a rare primary cerebral leiomyosarcoma in an 8-year-old male is described. The patient presented with a new-onset seizure disorder and was found to have a rapidly expanding left parietal extra-axial lesion, documented by radiological imagings. The patient underwent surgical resection of the leiomyosarcoma, as well as adjuvant radiotherapy and chemotherapy. He is still surviving to date in stable neurological condition. The clinical presentation, surgical procedure, pathological findings and post-operative clinical course will be reported. The possible etiology of this rare extra-axial neoplasm is discussed.

Cost-effectiveness and efficacy of an on-site homograft heart-valve bank.

OBJECTIVE: To compare the performance and cost-effectiveness of cryopreserved homograft cardiac valves prepared on site to valves prepared commercially. DESIGN: A review of all patients who received homograft heart valves between January 1990 and December 1993, with cost-effectiveness analysis. Follow-up ranged from 1 to 37 months (mean 12 months). SETTING: Tertiary-care adult and pediatric hospitals. PATIENTS: All consecutive patients receiving homograft heart valves in either the aortic or right ventricular outflow tract (RVOT) position since on-site preparation of cryopreserved cardiac valves began in 1990. Forty-three patients received 47 homograft valve replacements: 18 in the aortic position and 29 in the RVOT position. No patients were lost to follow-up. MAIN OUTCOME MEASURES: Valve function as assessed by patient survival, actuarial freedom from reoperation and Doppler echocardiographic assessment of transvalvar gradients and valvar insufficiency. Cost-effectiveness as assessed by a formal evaluation of on-site costs compared with current prices for commercially prepared valves. RESULTS: There were four operative deaths but no late deaths. Four valves were removed. Freedom from reoperation at 3 years was 100% for aortic valve replacement and 85% for RVOT reconstruction. Echocardiographic follow-up of 34 of the remaining 39 patients showed mild or no insufficiency in 24 valves, moderate insufficiency in 8 valves and severe, but not clinically significant, insufficiency in 2 valves. The cost of on-site preparation of the valves was $1363 compared with $5040 for the commercially prepared valves, a cost saving for the group of $172,819. CONCLUSION: On-site preparation is an effective method of preparing cryopreserved cardiac valves and permits significant cost savings.

Split notochord syndrome: case report.

Split notochord syndrome includes a cleft of the vertebral column associated with malformation of the central nervous system. Fourteen cases involving the lumbosacral spine have been reported in the literature. We report on a female neonate who had intact function of her lower extremities, a posterior midline lumbar defect bounded by two complete spinal canals that contained two spinal cords. A meningocele, a large bowel fistula, and a mature teratoma protruded through the cleft. The baby is doing well after repair of the anomaly and placement of a ventriculoperitoneal shunt.

Acquired double elevator palsy in a child with a pineocytoma.

PURPOSE/METHODS: We examined an 8-year-old girl who had an acquired double elevator palsy and a histopathologically confirmed benign pineocytoma. RESULTS/CONCLUSIONS: Mass lesions in the region of the pineal gland can produce monocular blepharoptosis and supranuclear upgaze paresis with the resultant clinical picture of double elevator palsy.

The monobloc frontofacial advancement: do the pluses outweigh the minuses?

The results of 32 patients who underwent transcranial monobloc frontofacial advancement by the senior author (Wolfe) are examined. Fifteen of the patients were Crouzon's and 17 were Apert's, 14 of whom also underwent simultaneous facial bipartition. The ages ranged from 7 months to 14 years. Although a transcranial facial advancement carries with it substantial risks, with careful consideration of airway control, the anterior cranial base dura, and the retrofrontal dead space, the procedure is recommended for carefully selected patients. The indications and contraindications for the procedure in various age groups are given.

History of pediatric neurosurgery in the United States and Canada.

Neurosurgery was sporadically practiced on children from prehistoric times until the Harvey Cushing era. The formal development and teaching of the specialty was begun by Franc Ingraham under Cushing's direction in 1929. The growth of pediatric neurosurgery at Boston Children's Hospital under the direction of Franc Ingraham and Donald Matson until the late 1960s is described, as is its subsequent spread throughout the United States and Canada. More recently, a number of societies and journals have played important roles in shaping and advancing the specialty. Currently, a proposal to require additional training for certification in pediatric neurosurgery is being considered by several organizations in North America.

Vertebral artery aneurysm--a unique hazard of head banging by heavy metal rockers. Case report.

A 15-year-old drummer in a neighborhood rock music band suffered a traumatic true aneurysm of the cervical vertebral artery from violent head and neck motion. He underwent excision of the aneurysm after distal and proximal ligation of the artery. He is neurologically normal 1 year after surgery. The mechanisms of injury caused by extremes of cervical motion, as well as 5 previously reported cases of extracranial vertebral artery aneurysm from closed trauma, are discussed. Excision of vertebral artery aneurysms in patients with emboli from a mural thrombus is recommended. The consequences of vertebral artery ligation and the indications for distal reconstruction are discussed.

Posterior fossa arachnoid cyst presenting with an isolated twelfth nerve paresis. Case report and review of the literature.

An unusual case of a posterior fossa arachnoid cyst containing atypical fluid is described in a patient presenting with an isolated ipsilateral twelfth nerve paresis. Despite the chronicity of symptoms, surgical decompression resulted in a satisfactory functional recovery.

Intraoperative sonography in spinal dysraphism and syringohydromyelia.

The use of intraoperative sonography was analyzed in 24 patients with spinal dysraphism and syringohydromyelia in order to determine the role of real-time sonography in the surgical management of these patients. Specific diagnoses included tethered cord (nine), syringohydromyelia (seven), congenital tumor unassociated with a tethered cord (four), diastematomyelia (three), and occult sacral meningocele (one). Intraoperative sonography determined the exact relationship of congenital tumors to the cord before opening the dura, which allowed a more precise approach to the mass. Intraoperative sonography identified the lower end of the syrinx cavities, which allowed optimal catheter placement. Fibroglial scar tissue, which may compartmentalize these syrinx cavities, was clearly shown, and the efficacy of shunt catheter placement was immediately determined. In diastematomyelia, intraoperative sonography identified the relationship of the hemicords to bony, cartilaginous, and/or fibrous septa and demonstrated the effect on the tethered hemicords of removing these septa and constructing a single dural sac from the two dural sacs that had enclosed the hemicords. Since significant surgical decisions are based on these sonographic observations, the authors urge widespread use of intraoperative sonography in patients with spinal dysraphism and syringohydromyelia.

Cerebrospinal fluid and extracellular fluid: their relationship to pressure and duration of canine hydrocephalus.

Fifteen greyhound dogs were made hydrocephalic by the transsphenoidal injection of silicone into the basal cisterns at the level of the tentorial incisura. Six of these animals had ventriculocisternal perfusions 4 weeks later and six at 8 weeks, half at 150 and half at 100 mm H2O. Three 12-week dogs were perfused at 150 mm H2O. Serial sections of brain from the ependyma of the left frontal horn to the overlying pia were counted for 14C inulin and 3H methotrexate uptake. Tissue concentrations of both markers varied indirectly with distance from ependyma and from pia, and varied directly with perfusion pressure. The data indicate that the diffusional pathway between cerebrospinal fluid (CSF) and extracellular fluid (ECF) can be modified by CSF pressure changes, i.e., CSF flows from the ventricles and subarachnoid space into the extracellular space when CSF pressures are raised. Brain uptake of inulin and methotrexate was significantly increased in the dogs made hydrocephalic 4 weeks prior to perfusion, but was less so in the 8-week hydrocephalics. Uptake of the tracers in three 12-week animals was similar to that found previously in normal dogs at elevated pressures. These findings correspond in location and time to the periventricular lucencies that are seen by computed tomography in human subacute hydrocephalus. They are apparently due to pressure-related changes in the volume of the ECF.

Cushing's disease in childhood: benign intracranial hypertension after trans-sphenoidal adenomectomy. Case report.

A 7-year-old girl presented with the physical and endocrinological stigmata of Cushing's disease. An adrenocorticotropic hormone (ACTH)-producing pituitary microadenoma was excised. Three weeks after trans-sphenoidal adenomectomy, the patient developed benign intracranial hypertension. Although ACTH levels had decreased to normal, the serum cortisol had fallen to subnormal levels. The child responded to exogenous steroid therapy, which was gradually tapered and discontinued after 5 months. Normal pituitary and adrenal functions persist 2 years later.

Transsphenoidal injection of silicone for the production of communicating or obstructive hydrocephalus in dogs.

A technique for the insertion of a spinal needle through the soft palate and sphenoid bone into the suprasellar cistern of dogs is described. Instillation of room-temperature-curing silastic elastomer via the needle causes an increased resistance to the flow of cerebrospinal fluid in the basal subarachnoid spaces above the tentorium, for the production of communicating hydrocephalus. If the needle is advanced farther, the same material can be injected directly into the third ventricle for the production of obstructive hydrocephalus. Twenty-five of 34 dogs (74%) developed hydrocephalus and survived to undergo subsequent experimentation.

Manifestations and therapeutic considerations in pineal yolk-sac tumors. Case report.

A 20-month-old patient with a paraventricular and parapineal yolk-sac tumor was treated with subtotal excision and total neuraxis irradiation. She has done well in the 3 1/2 years since surgery. A comparative review of similar pineal and gonadal yolk-sac tumors suggests role for surgery combined with radiotherapy and chemotherapy. Additional experience with these unusual germ-cell neoplasms should establish the need for aggressive extirpation, not only to determine the exact diagnosis, but also to provide the basis for subsequent adjunctive therapy. The latter may include specific combination of antineoplastic drugs in addition to radiation.

CSF rhinorrhea from a transclival meningocele demonstrated with metrizamide CT cisternography. Case report.

A 63-year-old woman with a 10-year history of intermittent cerebrospinal fluid (CSF) rhinorrhea was found to have a transclival meningocele. After pluridirectional tomography demonstrated a bone defect in the clivus, the diagnosis was established by means of computerized tomography (CT) by comparing the absorption coefficients of a soft-tissue mass within the sphenoid sinus before and after the injection of metrizamide into the lumbar subarachnoid space. An increase of 39 absorption units clearly indicated the movement of CSF from the prepontine subarachnoid space into the sphenoid sinus. This case illustrates the value of metrizamide CT cisternography in the evaluation of patients with CSF rhinorrhea.

Prolactin-producing pituitary adenomas.

Eight patients with amenorrhea, galactorrhea, and hyperprolactinemia underwent excision of pituitary adenomas by means of a microsurgical procedure that used a transsphenoidal approach. Prolactin values returned to normal in five of the patients and were significantly lower in three. Five patients resumed their menses. Two became pregnant. All eight patients had used oral contraceptives. The association of oral contraceptives and prolactin-producing pituitary adenomas is discussed.

Posterior cranial fossa and temporal bone meningioma in a child, appearing as a neck mass.

Meningiomas are usually benign lesions that rarely involve the temporal bone and rarely occur in children or adolescents. A case of a posterior cranial fossa and temporal bone meningioma in a 9-year-old girl is presented; no similar case was found in the world literature.