How many growing vestibular schwannomas tend to stop growing without any treatment?

OBJECTIVE: To determine the long-term, spontaneous growth arrest rates in a large cohort of vestibular schwannoma patients. METHODS: This paper describes a retrospective case series of 735 vestibular schwannoma patients organised into four groups: group A patients showed tumour growth which then stopped without any treatment; group B patients showed tumour growth which continued, but were managed conservatively; group C patients had a growing vestibular schwannoma and received active treatment; and group D patients had a stable, non-growing vestibular schwannoma. Demographics, tumour size and vestibular schwannoma growth rate (mm/month) were recorded. RESULTS: A total of 288 patients (39.2 per cent) had growing vestibular schwannomas. Of the patients, 103 (35.8 per cent) were managed conservatively, with 52 patients (50.5 per cent of the conservative management group, 18 per cent of the total growing vestibular schwannoma group) showing growth arrest, which occurred on average at four years following the diagnosis. Eighty-two per cent of vestibular schwannomas stopped growing within five years. Only differences between age (p = 0.016) and vestibular schwannoma size (p = 0.0008) were significant. CONCLUSION: Approximately 20 per cent of growing vestibular schwannomas spontaneously stop growing, predominantly within the first five years; this is important for long-term management.

Intraosseous soft tissue perineurioma: report of a vertebral example.

OBJECTIVE: To describe a unique intraosseous perineurioma affecting the L2 vertebral body and pedicle of a 28-year-old female. MATERIAL: A lytic, expansive lesion virtually limited to bone was gross totally excised; only minimal epidural extension was noted. METHODS: Histologic, immunohistochemical and ultrastructural studies were performed. RESULTS: The tumor was partially encapsulated, moderately cellular, and showed classic features of benign soft tissue perineurioma, being composed of interlacing fascicles of spindle cells with undulating nuclei and long, very narrow, cytoplasmic processes. Immunohistochemistry showed reactivity for EMA, Glut-1, claudin, collagen-4 and CD34; no S-100 or neurofilament protein staining was seen to suggest an origin in nerve. CONCLUSION: Perineurioma, a tumor affecting soft tissue, and presumably nerve-unassociated, may affect bone. No prior entirely osseous examples have been reported. This tumor expands the differential diagnosis of spindle cell tumors of bone.

Helminths in sympatric populations of mountain reedbuck (Redunca fulvorufula) and gray rhebok (Pelea capreolus) in South Africa.

Helminths of mountain reedbuck (Redunca fulvorufula fulvorufula) and gray rhebok (Pelea capreolus) were investigated in South Africa between June 1999 and February 2002. Forty-one mountain reedbuck were culled at Sterkfontein Dam Nature Reserve over 8 different periods, and 25 mountain reedbuck were culled at Tussen die Riviere Nature Reserve over 3 different periods. A total of 17 kinds of helminths were found at the 2 sites, including 15 nematodes, 1 trematode, and 1 cestode. At Sterkfontein, the most prevalent and abundant species were Cooperia yoshidai, Longistrongylus schrenki, and Haemonchus contortus, with the latter 2 being more abundant during November/December than at other times of the year, probably because infective larvae increased on pasture at that time. No statistical differences were found in parasite loads between male and female mountain reedbuck. No correlation was found between fecal egg counts and adult worm counts or between parasite counts and body condition. At Tussen die Riviere, helminths in mountain reedbuck were less prevalent and abundant than at Sterkfontein. The most important species were Nematodirus spathiger, Trichostrongylus falculatus, and Cooperia rotundispiculum. Four gray rhebok died of natural causes at Sterkfontein, from which 5 kinds of helminths were recovered, including C. yoshidai and Paracooperioides peleae.

Application of ion exchange and extraction chromatography to the separation of actinium from proton-irradiated thorium metal for analytical purposes.

Actinium-225 (t1/2=9.92d) is an α-emitting radionuclide with nuclear properties well-suited for use in targeted alpha therapy (TAT), a powerful treatment method for malignant tumors. Actinium-225 can also be utilized as a generator for (213)Bi (t1/2 45.6 min), which is another valuable candidate for TAT. Actinium-225 can be produced via proton irradiation of thorium metal; however, long-lived (227)Ac (t1/2=21.8a, 99% ß(-), 1% α) is co-produced during this process and will impact the quality of the final product. Thus, accurate assays are needed to determine the (225)Ac/(227)Ac ratio, which is dependent on beam energy, irradiation time and target design. Accurate actinium assays, in turn, require efficient separation of actinium isotopes from both the Th matrix and highly radioactive activation by-products, especially radiolanthanides formed from proton-induced fission. In this study, we introduce a novel, selective chromatographic technique for the recovery and purification of actinium isotopes from irradiated Th matrices. A two-step sequence of cation exchange and extraction chromatography was implemented. Radiolanthanides were quantitatively removed from Ac, and no non-Ac radionuclidic impurities were detected in the final Ac fraction. An (225)Ac spike added prior to separation was recovered at ≥ 98%, and Ac decontamination from Th was found to be ≥ 10(6). The purified actinium fraction allowed for highly accurate (227)Ac determination at analytical scales, i.e., at (227)Ac activities of 1-100 kBq (27 nCi to 2.7 µCi).

Gamma-linolenic acid for attention-deficit hyperactivity disorder: placebo-controlled comparison to D-amphetamine.

In a Latin-square double-crossover with random assignment to sequence, 18 boys, aged 6-12 years, with attention-deficit hyperactivity disorder received 1 month each of placebo, D-amphetamine, and Efamol (evening primrose oil containing gamma-linolenic acid, with vitamin E as preservative). Parents' ratings were noncontributory. Teachers' ratings showed a trend of Efamol effect between placebo and D-amphetamine. The trend reached significance (p less than 0.05) only on Conners Hyperactivity Factor. Dosage may be crucial; 8 Efamol capsules per day were used in this study. Heuristic data scrutiny suggested possible interaction (sequence effect). Further study with a different design and dose is suggested. This study does not establish Efamol as an effective treatment.

T cell activation in Guillain-Barré syndrome and in MS: elevated serum levels of soluble IL-2 receptors.

Guillain-Barré syndrome (GBS), chronic idiopathic demyelinating polyradiculoneuropathy (CIDP), and multiple sclerosis (MS) are disorders with presumed immunopathogenesis. To obtain evidence for T cell activation, we determined serum concentrations of soluble interleukin-2 receptors (sIL-2 R) in 50 patients with GBS, 24 with CIDP, and 54 with MS. Both in GBS and clinically active MS sIL-2 R levels were markedly increased compared with those in patients with other neurologic diseases. Four of 24 CIDP patients had abnormally increased sIL-2 R concentrations. sIL-2 R concentrations decreased with clinical improvement in serial samples taken from GBS patients, but were not otherwise correlated with disease severity. These data establish that T cells are activated in GBS and some patients with CIDP, and corroborate earlier evidence that activated T cells are circulating in the blood of MS patients.

Responsiveness to P2 of blood- and cauda equina-derived lymphocytes in experimental allergic neuritis in the Lewis rat: preliminary characterisation of a P2-specific cauda equina-derived T cell line.

Experimental allergic neuritis (EAN) was induced in Lewis rats by immunisation with bovine spinal root myelin. Neurological signs appeared on day 12 and persisted for 10-15 days. A transient protein P2-specific proliferative response of circulating mononuclear cells was detected on days 10 and 14 after immunisation but not on days 17 and 35. Mononuclear cells recovered from cauda equina infiltrates on days 14 and 17 showed greater responsiveness to P2 than circulating cells. A P2-specific, interleukin-2-dependent T cell line has been developed from cauda equina (CE)-derived lymphocytes. In adoptive transfer experiments this cell line did not induce EAN but did protect normal recipients from actively induced EAN.

T lymphocyte activation antigens in Guillain-Barré syndrome and chronic idiopathic demyelinating polyradiculoneuropathy.

Activated circulating T lymphocytes were measured in ten patients with Guillain-Barré syndrome (GBS) and in ten with chronic idiopathic demyelinating polyradiculoneuropathy (CIDP), each paired with an age- and sex-matched healthy control. Activated T cells were identified by double labelling with phycoerythrin-conjugated anti-CD3 antibody and biotinylated antibodies to activation antigens: human leucocyte antigen (HLA)-DR, transferrin receptor (TFR) or interleukin-2 receptor (IL-2R) visualised with an avidin-biotin-fluorescein system. The frequency of activated T cells was increased in the GBS group. The median of the DR-positive T cells in the patients was 3.4% (range 0.5-9.4%), compared with 1.4% (range 0-4.3%) in the controls (P less than 0.01). For TFR the corresponding medians were 3.3% (range 0.5-6.2%) in the patients and 0% (range 0-2.5%) in the controls (P less than 0.01), and for IL-2R 3.7% (range 0-6.0%) in the patients compared with 0% (range 0-2.9%) in the controls (P less than 0.01). In the CIDP group the median percentage of activated T cells was also increased but the differences were less significant: for DR, patients 2.4% (range 0-3.8%), controls 0.5% (range 0-2.0%, P less than 0.05); for TFR, patients 0% (range 0-5.3%), controls 0% (range 0-1.0%, not significant), and for IL-2R, patients 0% (range 0-2.5%), controls 0% (range 0-0.5%, not significant). The activated cells might be directed against microbial antigens encountered during the infection preceding GBS, autoantigens, bacterial antigens encountered during concurrent infection, or a combination of these.

Experimental allergic neuritis induced in SJL mice by bovine P2.

Bovine myelin or bovine myelin-derived P2 protein was injected into 4 inbred mouse strains. SJL mice developed neurological deficit, and histological lesions characteristic of experimental allergic neuritis. BALB/C, CBA and C57.B1/6 mice were relatively resistant to disease induction by this method.

Lack of effect of fish oil-enriched diet on experimental allergic neuritis in Lewis rats.

Lewis rats were maintained on a diet enriched with menhaden oil, a rich source of the arachidonic acid (AA) substitute eicosapentaenoic acid (EPA). After dietary manipulation the blood neutrophils showed normal leukotriene (LT)B4 but increased LTB5 concentrations, and the CD4+/CD8+T lymphocyte subset ratio was temporarily perturbed. The dietary manipulation did not affect the severity of actively induced experimental allergic neuritis (EAN).

Effect of pyocyanin and 1-hydroxyphenazine on in vivo tracheal mucus velocity.

Products of the bacterium Pseudomonas aeruginosa have been shown to slow the beating of human respiratory tract cilia in vitro. We have tested the effects of two of these compounds, pyocyanin and 1-hydroxyphenazine (given as a bolus dose dissolved in 2 microliters Ringer solution), on tracheal mucus velocity of radiolabeled erythrocytes in anesthetized guinea pigs. 1-Hydroxyphenazine (200 ng) caused a rapid slowing of tracheal mucus velocity (maximum fall 47% at 20 min) with recovery by 1 h. The effect of pyocyanin was slower in onset, 600 ng causing 60% reduction in tracheal mucus velocity at 3 h, and no recovery occurred. A combination of pyocyanin and 1-hydroxyphenazine produced an initial rapid slowing equivalent to the same dose of 1-hydroxyphenazine given alone, but the later slowing attributed to pyocyanin was greater than the same dose administered alone. This study demonstrates one mechanism by which products of P. aeruginosa may facilitate its colonization of the respiratory tract.

Major histocompatibility antigens and lymphocyte subsets during experimental allergic neuritis in the Lewis rat.

Major histocompatibility antigens were identified in frozen sections of normal Lewis rat peripheral nerve tissue with monoclonal antibodies and an avidin-biotin-peroxidase complex system. Class I antigen is normally required for cytotoxic/suppressor T lymphocyte function and class II antigen for activation of helper T lymphocytes. In the sciatic nerves class I antigen was expressed diffusely by most endoneurial and perineurial cells but class II antigen only by a minority. In the cauda equina class I antigen was expressed by all arachnoid and some endoneurial cells, while class II antigen was expressed by a smaller proportion of arachnoid cells in the endoneurium of spinal roots and interstitial cells surrounding dorsal root ganglion neurons. The endothelium of endoneurial, perineurial and meningeal vessels uniformly expressed class I but not class II antigen. Experimental allergic neuritis was induced in Lewis rats by immunisation with bovine intradural root myelin. Early lesions consisted of multifocal infiltration of the nerve roots by cells expressing leucocyte common antigen. Surrounding endoneurial cells showed markedly increased expression of major histocompatibility antigens. In inflammatory lesions about 10% of the cells were stained with pan T cell antibodies. T lymphocyte subsets were identified with antibody W3/25 for helper cells and MRC OX-8 for cytotoxic/suppressor cells. The W3/25 positive cells were usually slightly in excess of OX-8 positive cells and their relative proportions did not alter during the disease. The presence of class I antigen on normal endothelium and its increased expression on endoneurial cells in the early phase of inflammation suggest an important role for class I restricted lymphocytes in the pathogenesis of the early stages of experimental allergic neuritis.

P2 specific lymphocyte transformation in Guillain-Barré syndrome and chronic idiopathic demyelinating polyradiculoneuropathy.

Thymidine incorporation proliferation assays to whole bovine P2 protein and its 58-81 and 14-25 synthetic peptides were performed on blood mononuclear cells from ten patients with Guillain-Barré syndrome (GBS), six patients with chronic idiopathic demyelinating polyradiculoneuropathy (CIDP), and age and sex matched normal subjects. The only patients whose cells showed any response were two out of four with very early GBS. One responded to P2 and both synthetic peptides. One responded to P2 but to neither peptide. The results support a role for cell mediated immunity to P2 protein in some patients with Guillain-Barré syndrome.

P0 myelin protein produces experimental allergic neuritis in Lewis rats.

P0 protein was prepared from bovine spinal root myelin. The purity was shown by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunostaining with affinity purified antisera. P0 in the presence of lysophosphatidylcholine induced paralysis and histological lesions resembling experimental allergic neuritis in Lewis rats. Lysophosphatidylcholine also enhanced the ability of P2 to produce neuritis. The conformation of these proteins may be important in determining their ability to induce experimental allergic neuritis. P0 deserves consideration as an antigen relevant to Guillain-Barré syndrome.

Anterior sacral meningocele associated with a rectal fistula. Case report and review of the literature.

The authors report a case of anterior sacral meningocele associated with a rectal fistula in a patient who had presented 20 years earlier with bacterial meningitis. To their knowledge, this is the first case in which a rectal fistula developed due to an anterior sacral meningocele. The clinical presentation, diagnosis, and treatment of this uncommon lesion is discussed.

Multiple dural metastases from a pituitary adenoma. Case report.

Only 12 cases of pituitary tumors that metastasized within the central nervous system have been reported. A further case is presented in which the histology of the multiple dural metastases remained identical to that of the original tumor, a pituitary adenoma. The authors discuss management of these rare lesions that appear histologically benign.

Timing of postoperative intracranial hematoma development and implications for the best use of neurosurgical intensive care.

This study records the incidence and timing of postoperative hematomas in neurosurgical patients and analyzes the best use of neurosurgical intensive care. In 2305 patients undergoing freehand or stereotactic biopsy, elective or emergency craniotomy, or posterior fossa surgery, 50 (2.2%) developed a hematoma. Clinical deterioration as a result of postoperative hematoma occurred within 6 hours of surgery in 44 patients and more than 24 hours after surgery in six patients. Although patients undergoing posterior fossa surgery or emergency craniotomy warrant longer periods of intensive-care observation, patients having elective supratentorial operations can safely be transferred to a neurosurgical ward for observation, provided they have regained their preoperative neurological status by 6 hours postsurgery.

Testicular and epididymal sperm content in grazing Cashmere bucks: seasonal variation and prediction from measurements in vivo.

Each month, for 15 months, the testes and epididymides were recovered from five Australian cashmere bucks selected at random from a group of mature bucks (initial n = 116) at pasture (location 29 degrees S, 153 degrees E). The extent of seasonal change in testicular and epididymal sperm reserves was determined and indirect methods for predicting these reserves were developed. Paired testicular weight exhibited clear seasonal variation from 137 g in August to 269 g in February. The total elongated spermatid content of the testes, determined by homogenization, showed a very similar seasonal pattern, ranging from 13.8 x 10(9) in September to 36.2 x 10(9) in March. Seasonal changes of similar timing were observed for paired epididymal weight and sperm content. Although changes in total testicular spermatid content were largely the result of change in testicular weight (R2 = 0.72, P < 0.001), the elongated spermatid content of testicular parenchyma (mean, 127 x 10(6) g-1) exhibited significant seasonal variation with elevated values between February and June, suggestive of an increase in the efficiency of spermatogenesis. Daily sperm production, calculated by means of a spermatogenic time divisor for sheep, ranged from 2.76 x 10(9) in September to 7.23 x 10(9) in February. Scrotal circumference, scrotal volume and testicular length x diameter2 were identified as accurate predictors of testicular weight (R2 > or = 0.87) and sperm content (R2 > or = 0.70). The results demonstrate that: (a) cashmere bucks exhibit considerable seasonal variation in spermatogenesis associated primarily with changes in testicular mass but also with changes in the efficiency of spermatogenesis; and (b) indirect measures of testicular size are good predictors of testicular elongated sperm content. When the correct spermatogenic time divisor for goats is determined, such indirect measures may be used to predict daily sperm production.

Acute treatment of alcohol and cocaine emergencies.

This chapter addresses the acute treatment of alcohol and cocaine. Because of the widespread use of both these drugs, health professionals must recognize the medical complications of alcohol and cocaine abuse and addiction. The biochemistry will be briefly reviewed as an avenue to understand the different treatment targets and modalities.

Parasites of South African wildlife. XVIII. Cooperia pigachei n. sp. (Nematoda: Cooperiidae) from the mountain reedbuck, Redunca fulvorufula (Afzelius, 1815).

A new species of Cooperia, for which the name Cooperia pigachei n. sp. is proposed, was recovered from a mountain reedbuck, Redunca fulvorufula, from the Sterkfontein Dam Nature Reserve, Free State Province, and is described and illustrated. It is close to Cooperia neitzi Mönnig, 1932 and the South African race of Cooperia rotundispiculum in having more than 14 longitudinal cuticular ridges and in that the lateral cervical synlophe is of the closed type. The new species differs from all the other species of the genus in that the lateral branches of the dorsal ray are large and T-shaped. The spicules are robust, over 0.3 mm long and have large, curved shoes on their tips.