Computed orbital phlebography of the cavernous sinuses

Computed orbital phlebography (COP), described as computed tomography with concomitant injection of contrast medium into a frontal vein, was used to evaluate the cavernous sinuses in 19 patients with intrasellar or parasellar lesions and in two normal controls. Bilateral opacification occurred in 12 subjects, eight of whom had pituitary tumors. Unilateral partial obliteration was encountered in four subjects, all of whom had pituitary tumors with marked parasellar extension. In three subjects with parasellar tumors, ipsilateral total obliteration of the cavernous sinus was seen. In one subject with no sign of parasellar tumor, there was no opacification of the cavernous sinuses, a failure attributed to technical factors. In one other subject, the frontal vein puncture was unsuccessful and COP could not be performed.     

Ex vivo gene delivery of GDNF using primary astrocytes transduced with a lentiviral vector provides neuroprotection in a rat model of Parkinson's disease

Astrocytes are, as normal constituents of the brain, promising vehicles for ex vivo gene delivery to the central nervous system. In the present study, we have used a lentiviral vector encoding glial cell line-derived neurotrophic factor (GDNF) to transduce rat-derived primary astrocytes, in order to evaluate their potential for long-term transgene expression in vivo and neuroprotection in a rat model of Parkinson's disease. Following transplantation of GDNF-transduced astrocytes to the intact striatum, the level of released GDNF was 2.93 +/- 0.28 ng/mg tissue at 1 week post-grafting, reduced to 0.42 +/- 0.12 ng/mg tissue at 4 weeks, and thereafter was maintained at this level throughout the experiment (12 weeks; 0.53 +/- 0.068 ng/mg tissue). Similarly, grafting to the substantia nigra (SN) resulted in a significant overexpression of GDNF ( approximately 0.20 ng/mg tissue) at 1 week. Intact animals receiving transplants of GDNF-transduced astrocytes displayed an increased contralateral turning (5.39 +/- 1.19 turns/min) in the amphetamine-induced rotation test, which significantly correlated with the GDNF tissue levels measured in the striatum, indicating a stimulatory effect of GDNF on the dopaminergic function. Transplantation of GDNF-transduced astrocytes to the SN 1 week prior to an intrastriatal 6-hydroxydopamine lesion provided a significant protection of nigral tyrosine hydroxylase-positive cells. By contrast, when the cells were transplanted to the striatum, the level of released GDNF was not sufficient to rescue the striatal fibers and, hence, to protect the nigral dopaminergic neurons. Overall, our results suggest that genetically modified astrocytes expressing GDNF can provide neuroprotection in a rat model of Parkinson's disease following transplantation to the SN.     

Borrelia burgdorferi persists in the brain in chronic lyme neuroborreliosis and may be associated with Alzheimer disease

The cause, or causes, of the vast majority of Alzheimer's disease cases are unknown. A number of contributing factors have been postulated, including infection. It has long been known that the spirochete Treponema pallidum, which is the infective agent for syphilis, can in its late stages cause dementia, chronic inflammation, cortical atrophy and amyloid deposition. Spirochetes of unidentified types and strains have previously been observed in the blood, CSF and brain of 14 AD patients tested and absent in 13 controls. In three of these AD cases spirochetes were grown in a medium selective for Borrelia burgdorferi. In the present study, the phylogenetic analysis of these spirochetes was made. Positive identification of the agent as Borrelia burgdorferi sensu stricto was based on genetic and molecular analyses. Borrelia antigens and genes were co-localized with beta-amyloid deposits in these AD cases. The data indicate that Borrelia burgdorferi may persist in the brain and be associated with amyloid plaques in AD. They suggest that these spirochetes, perhaps in an analogous fashion to Treponema pallidum, may contribute to dementia, cortical atrophy and amyloid deposition. Further in vitro and in vivo studies may bring more insight into the potential role of spirochetes in AD.     

Variation in the position and orientation of the elbow flexion axis

We analysed the axis of movement in the normal elbow during flexion in vivo using radiostereometric analysis (RSA). The results show an intraindividual variation in the inclination of the axis ranging from 2.1 degrees to 14.3 degrees in the frontal and from 1.6 degrees to 9.8 degrees in the horizontal plane analysed at 30 degrees increments. The inclination of the mean axis of rotation varied within a range of 12.7 degrees in the frontal and 4.6 degrees in the horizontal plane. In both planes, the mean axes were located close to a line joining the centres of the trochlea and capitellum. The intra- and interindividual variations of the axes of flexion of the elbow were greater than previously reported. These factors should be considered in the development of elbow prostheses.     

The dental follicle in normally and ectopically erupting maxillary canines: a computed tomography study

The subjects in the study were children who were X-rayed because of increased risk for resorption following ectopically erupting maxillary canines. One hundred and seven children 9 to 15 years of age with 156 maxillary canines that were erupting ectopically and 58 normally were investigated by computed tomography (CT) to describe the features of the dental follicles of the erupting maxillary canines. Contiguous, transverse CT scans were exposed through the maxilla in the canine region and the width and shape of the dental follicles were registered scan by scan throughout the extension of the follicle. The width and the shape of the dental follicle of the erupting maxillary canine varied greatly. The range of the maximum width, measured from the crown to the periphery of the follicle, was 0.5-7.0 mm, with a mean of 2.9 mm and a 95% confidence interval of 2.7-3.2 mm for the entire sample. No relationship was found between the width or shape of the follicles and sex, age, stage of eruption, inclination of the canine, or width of the dental arch. However, the location of the maxillary canine vis-à-vis the adjacent incisor was significantly associated with the width of the follicle, which indicated that local anatomic conditions might influence the width and shape of the follicle. The dental follicles of the ectopically erupting canines were, on average, wider than those of the normally erupting canines. The 95% confidence interval for the normally erupting canines was 2.3-2.7 mm; for the buccally erupting canines 2.4-4.1 mm; for the lingually erupting canines 2.6-3.0 mm; and for the apically erupting canines in relation to the lateral incisors 2.9-4.1 mm. Canine follicles that were wide but within normal limits did not cause deviations in adjacent teeth. Cystically degenerated dental follicles were found but were indistinguishable on the CT scans from those that had been widened physiologically. The contributions of the studied variables to the variation in the width of the dental follicle of the maxillary canine were analyzed with regression models.     

Scopolamine does not restore normal conditioned avoidance performance in raclopride-treated rats

Summary. Several studies have shown antagonism by anticholinergics of antipsychotic-induced suppression of conditioned avoidance behavior, as well as of catalepsy, in rats. These observations provide pharmacological evidence for these behaviors mediated via nigro-striatal dopaminergic projections, as well as known dopaminergic-cholinergic interactions in the neostriatum. The objective of the present study was to examine the quality of behavioral change produced by scopolamine (0.25–1.00 mg kg⁻¹ s.c.) on conditioned avoidance behavior, by itself, and in combination with raclopride (0.1 mg kg⁻¹ s.c.) in the rat. Adult male Wistar rats were trained to perform a conditioned avoidance response requiring a brightness discrimination. A two-way avoidance shuttle-box was used with the modification that there were two passages in the partition separating the two compartments of the shuttle-box. In order to make a correct avoidance in the response to white noise conditioned stimulus, the rat had to take background light into consideration. Correct passage under dim background conditions was to the left and, with increased background lights, to the right. A weak, intermittent, electric shock (≈0.2 mA) was used as unconditioned stimulus. Scopolamine by itself (0.25–1.00 mg kg⁻¹ s.c.) disrupted the visual discrimination without affecting avoidance performance. As expected, raclopride (0.1 mg kg⁻¹ s.c.) produced a suppression of conditioned avoidance behavior. A dose of 1.00 mg kg⁻¹ of scopolamine was needed to restore raclopride-induced suppression of conditioned avoidance behavior. Thus, restoration of the avoidance behavior by scopolamine treatment was not possible at doses that allow normal performance of the visual discrimination. It is concluded that anticholinergics do not restore normal behavior after neuroleptic-induced suppression of conditioned avoidance behavior. Received July 21, 2000; accepted November 20, 2000     

Factor V deficiency in Philadelphia-positive chronic myelogenous leukemia

Factor V deficiency has been identified in 8 of 8 patients 7--20 yr of age, with Philadelphia-positive (Ph1+) chronic myelogenous leukemia (CML). In these 8 patients, factor V deficiency was not due to hepatic dysfunction, factor V inhibitors, or disseminated intravascular coagulation. In 3 patients, factor V activity rose 10%--12% (0.10--0.12 U/ml) after the infusion of 28--31 ml/kg body weight of fresh frozen plasma (FFP). The rise persisted less than 14 hr. The mean measured postinfusion rise in factor V was 18% of the expected rise calculated from the volume of FFP infused in the patients' plasma volume. In 4 patients, a small transient rise in factor V activity occurred after splenectomy or plateletpheresis. Factor V deficiency was completely corrected after a marked reduction in bone marrow cellularity in 2 patients with Ph1+ CML treated with extensive chemotherapy, total body irradiation, and bone marrow transplantation. Factor V deficiency was retrospectively observed in 6 of 20 patients, ages 20--80 yr, with Ph1+ CML and 3 of 6 patients with other myeloproliferative disorders. The factor V deficiency appears to be associated with the large myeloid- megakaryocytic cell mass characteristic of CML and other myeloproliferative disorders.