Electrophysiologic target localization in posteroventral pallidotomy

Summary The current interest in stereotactic posteroventral pallidotomy (PVP) for treating Parkinson's disease and the variability of published results have raised questions regarding techniques for target localization. In our technique the probe is guided to the optimum target at the most ventral pallidum and ansa lenticularis by macroelectrode stimulation of the internal capsule and optic tract from within the globus pallidus, with the thresholds providing a relative measure of the electrode proximity to these structures. We have characterized these localizing macroelectrode stimulation parameters in 57 posteroventral pallidotomies with consistent anatomic lesion placement, excellent outcome, and no complications.Using a 1.8 × 2.0 mm radiofrequency electrode for macroelectrode stimulation (RFG-3C, Radionics Inc.), minimum voltages (thresholds) to activate motor (at a frequency of 2 Hz) or visual (at a frequency of 100 Hz) responses as well as impedance measurements were obtained at the final target (Tf) and at distances proximal to Tf along the electrode trajectory. The visual and motor threshold voltages at Tf via our standard approach angles (50 ° above base plane, 20 ° from the sagittal plane), had a range of 1.0 to 1.5 V, and 2.0 to 3.5 V respectively. We also found that as the probe approaches Tf there is a significant decrease in voltage thresholds for motor (P<.0001) and visual (P<.0001) responses in an individual patient indicating that the probe is converging on these structures. Increases in impedance between Tf, 2–3 mm, and 4–5 mm proximal to Tf were also statistically significant (P<.0001). Microelectrode recording of electrophysiological neuronal activity at various points along the trajectory towards the target showed distinct firing patters providing identification of the globus pallidus externus and internus, ansa lenticularis, and optic tract.Macroelectrode electrophysiological stimulation within the target volume, inducing threshold responses in the internal capsule and optic tract, provides for accurate localization of the most effective PVP target in the ansa lenticularis. In unresponsive patients, the utilization of microelectrode recording for the identification of the pallidal borders and the optic tract improves safety.     

Failure of in vitro-expanded hyperimmune cytotoxic T lymphocytes to affect survival of mouse embryos in vivo

This study was designed to address the question; does expression of paternal histocompatibility antigens by fetal cells make them susceptible to immune attack in vivo during normal pregnancy? The experimental design was based on the rationale that, if alloantigens are presented by trophoblasts or other fetal cells in a manner which allows accessibility, in vitro-generated immune effector cells of combined helper/cytotoxic phenotype should produce fetal rejection of abortion. Similarly generated effector cells are capable of accelerating skin graft rejection and, when combined with IL-2 in vivo, are capable of causing regression of antigenic, but operationally non-immunogenic, tumors. The alloimmune effector cells generated in vitro during the current study were highly cytotoxic against normal adult target cells, whereas placental cells were completely resistant to cytolysis and fetal cells were only slightly susceptible. Adoptive transfer of effector cells to mice at different stages of gestation had no apparent effect on pregnancy outcome. In vivo administration of IL-2 and/or indomethacin, which expand effector cell numbers in vivo and block PGE2-mediated immune suppression, respectively, failed to potentiate the cellular effect. The data provide additional evidence that paternal histocompatibility antigens are not expressed in a format which allows susceptibility to immune attack during pregnancy. The data are discussed with respect to the role of the trophoblast in protecting developing embryos.     

Effects of endurance exercise on the morphology of mouse neuromuscular junctions during ageing

Summary It has been suggested that age changes in the morphology of the neuromuscular junction (NMJ) may reflect altered physical activity levels rather than the unique effects of ageing. Additionally, previous studies have indicated that the structure of the NMJ may be modulated with exercise. To investigate these questions, quantitative morphometry was determined on soleus and extensor digitorum longus (EDL) nerve terminals stained with zinc iodide-osmium from C57BL/6NNia mice under control and endurance exercised conditions at 12, 18 and 24 months of age.As previously observed, the area, perimeter, extent length and branch number of nerve terminals increased with age in both soleus and EDL. The changes were similar between the muscle types, although the changes were more pronounced in the phasic EDL. In 12-month-old animals, 2 months of endurance exercise resulted in significantly larger nerve terminals in both soleus and EDL, suggesting a functional adaptation. Exercised 18- and 24-month-old nerve terminals were smaller than corresponding controls, which indicated that exercise minimized or prevented further age-related nerve terminal elaboration. At all ages the exercised nerve terminals comprised a more homogeneous population than corresponding controls, which indicates that uniform physical activity can modulate NMJ morphometry. The magnitude of the changes suggests that subtle alterations in normal cage activity with advancing age do not have a significant effect on the morphology of nerve terminals. However, the morphology of the NMJ does change significantly in response to physical exercise training.     

Radioimmunoassay method for the detection of IgE antibodies specific to alcuronium

A radio-immunoassay (RIA) was used to screen for specific IgE to myorelaxants. Alcuronium was coupled to epoxy-activated Sepharose. Sixteen patients with anaphylaxis to alcuronium (n = 2), gallamine (n = 2) or suxamethonium (n = 12) were studied. The diagnosis was established by intradermal tests (ID), passive cutaneous anaphylaxis tests and human basophil degranulation tests. The amount of non specific label retained by Sepharose-ethanolamine (with sera of patients) and Sepharose-alcuronium (with sera of 11 control subjects) was estimated. The RIA was positive 10/16 (8/14 patients having reacted to a muscle relaxant other than alcuronium). The RIA seemed to be useful in the diagnosis of anaphylaxis to muscle relaxants. Drug-reactive antibodies were specific of the quaternary ammonium radical, which was the common allergenic determinant of all molecules of muscle relaxants. This test accounted for in vitro cross-reactivity, but had no predictive value for the clinical risk of crossed-anaphylaxis. This risk was best assessed by ID; it was positive in three cases. Although it was not possible to compare ID and RIA, the interpretation of which was different, both tests should be recommended for the detection of sensitivity to muscle relaxants.     

Establishment and characterization of a new human Burkitt's lymphoma cell line (WSU-BL)

A new human cell line, WSU-BL, was established from a malignant ascitic fluid occurring in a patient with Burkitt's lymphoma. The established line grows in a single-cell suspension with a doubling time of 19 hours and expresses L3 morphologic features by the French-American-British classification. Immunologic study revealed that WSU-BL cells express IgM-lambda both in the cytoplasm and on the surface and react with monoclonal antibodies to B-cell antigens (B1, B4, BL3, BL4, HLA-DR, and common acute lymphoblastic leukemia antigen [CALLA]). These cells are negative for T-cell and myeloid/monocyte antigens as well as Epstein-Barr virus nuclear antigen (EBNA). These results suggest that WSU-BL corresponds to an intermediate stage of B-cell differentiation. Both fresh tumor and WSU-BL cells had a hyperdiploid karyotype carrying the 8;14 chromosome translocation. Molecular studies showed that WSU-BL has a rearrangement of c-myc proto-oncogene and expresses c-myc RNA. Phorbol ester 12-0-tetradecanoylphorbol-13-acetate (TPA) and interferon-gamma (IFN-gamma) were able to induce several phenotypic changes on WSU-BL cells. Two-dimensional gel electrophoresis of total cellular protein showed that either TPA or IFN-gamma induced both the synthesis or loss of several proteins. Analysis of the protein patterns indicated that some proteins were uniquely responsive to either TPA or IFN-gamma and others were common to both. This cell line should be valuable for future studies of cell proliferation, differentiation, and oncogenesis concerning this neoplasm.     

Concomitant administration of cyclosporine and ketoconazole in idiopathic nephrotic syndrome.

BACKGROUND: The deliberate use of ketoconazole to reduce the need for cyclosporine (CsA) is not new, but it is particularly relevant because of the high cost of CsA. Many studies have documented this benefit in renal and cardiac transplants, but this co-administration has not been reported in patients with nephrotic syndrome. METHODS: This retrospective study included 207 nephrotic patients who were steroid resistant, dependent or frequent relapsers and received CsA therapy. Among these patients 153 received daily ketoconazole therapy in a dose of 50 mg with concomitant decrease of one-third of the CsA dose while 54 patients received CsA alone. The majority of our cases were children (179 were below 18 years) and male to female ratio was 1.7:1. RESULTS: The great majority of the study population received the drugs for 1-2 years. Patients who received CsA and ketoconazole were comparable with those who received CsA alone regarding age, sex, duration of renal disease, renal pathology, severity of nephrotic syndrome, renal function, hepatic function and steroid response. Co-administration of ketoconazole significantly reduced mean doses of CsA by 37% after 1 month and 47% at 1 year with overall net cost savings of 37%. Hepatic functions remained within the normal range in both groups. Additionally, co-administration of ketoconazole significantly improved the response to CsA therapy, successful steroid withdrawal and decreased the frequency of renal impairment. CONCLUSIONS: Co-administration of keto with CsA in idiopathic nephrotic patients significantly reduces CsA costs and may improve its response.     

Slipped capital femoral epiphysis: an analysis of treatment outcome according to physeal stability.

INTRODUCTION: Slipped capital femoral epiphysis (SCFE) is a common hip disorder in adolescents. Treatment can be associated with serious complications, mainly avascular necrosis (AVN). The objective of this study was to evaluate treatment outcomes and complications based on physeal stability at presentation. METHODS: We reviewed retrospectively all children treated for SCFE from 1990 through 2000 at the Children's Hospital of Eastern Ontario, Ottawa. RESULTS: Of a total of 87 patients (56 male) identified, 73 had slips classed as stable and 14, unstable; 42 involved the left side, 34 the right, and 19 were bilateral. Avascular necrosis (AVN) developed in 1 patient with a stable slip (morbidity 1.4%) and in 3 with unstable slips (21.4%; p = 0.001). Manipulative anatomical reduction was done in 11 cases (78.5%), all unstable slips. All slips complicated by AVN had been classified according to the traditional system as acute-on-chronic. Complication rates differed significantly between unstable slips (36%) and stable (20%). No statistically significant association was found between AVN and slip severity, time to fixation or use of reduction. CONCLUSIONS: The treatment of stable slips exhibits a lower incidence of AVN. These results nevertheless suggest that gentle reduction of unstable slips is safe and unaccompanied by an increase in complications.     

Oesophageal pemphigus vulgaris

Symptomatic involvement of the oesophageal mucosa by pemphigus vulgaris is rare. We describe 1 patient who was treated with oral steroids during a blistering phase, when epigastric pain developed. Endoscopy revealed multiple ulcerations all over the oesophagus, but gastroduodenal mucosa was normal. The symptoms disappeared following cimetidine for gastro-oesophageal reflux and increase of steroid dosage. When painful symptoms appear from the upper digestive tract during corticosteroid treatment of pemphigus, the possibility of acantholytic involvement of oesophageal mucosa must be kept in mind. Its implication for the dosage of steroids is opposite that in steroid-induced peptic ulcers. Carefully performed upper gastrointestinal tract endoscopy is helpful in these patients.     

Screening of the antiradical action of vegetable oils

Information on radical scavenging activity (RSA) and antioxidant potential of vegetable oils are not reported, or reporting has been rather limited. Such data is of importance for the evaluation of nutritional and health impact of these oils. The main objective of this short study was to compare the antiradical performance of some common and unusual vegetable oils. The described arrangement for our simple experiment uses the addition of stable radicals 1,1-diphenyl-2-picrylhydrazyl (DPPH) to vegetable oils, which are decomposed by components having antioxidant properties. The order of effectiveness of oils in inhibiting free radicals was as follows: coriander>blackcumin>cottonseed>peanut>sunflower>walnut>hemp seed>linseed>olive>niger seed. This initial survey might serve as a springboard for future research into this area.