Imaging studies in a unique familial dysmyelinating disorder

We report the imaging findings in five patients with a unique dysmyelinating disorder. MR studies of these infants showed obstructive hydrocephalus caused by mass effect produced by an enlarged cerebellum. The white matter of an enlarged cerebrum and cerebellum showed delayed myelination. Proton spectroscopy showed normal N-acetylaspartate (NAA) levels. While the dysmyelinating disorder was clearly differentiated from Canavan disease by an absence of elevated NAA and differing histopathologic findings and autosomal-dominant inheritance pattern, there were similarities to this disease in the presentation and, to some extent, in the initial imaging findings.     

A vaccine consisting of recombinant Borrelia burgdorferi outer-surface protein A to prevent Lyme disease. Recombinant Outer-Surface Protein A Lyme Disease Vaccine Study Consortium

The purpose of this study was to determine whether infrared tympanic membrane thermometry can replace mercury-in-glass temperatures as an assessment tool for detecting fevers earlier and more reliably in a pediatric oncology outpatient setting. A total of 313 patient visits had infrared tympanic temperatures (obtained by using the LighTouch LTX Pedi-Q thermometer (Exergen; Watertown, MA) and axillary temperatures taken simultaneously (obtained by using mercury-in-glass thermometers). Those patients with a normal axillary temperature and an elevated tympanic measurement of 38 degrees C or higher had a follow-up axillary temperature conducted that evening to determine whether an elevated tympanic temperature predicted on coming fever or infection. The mean tympanic temperature was 37.5 degrees C and the mean axillary temperature was 36.8 degrees C, a difference of 0.7 degree C (P = .0001). Sixty-two (20%) patients had discrepant temperatures with a febrile tympanic and normal axillary measurement. Three (5%) of these patients were febrile at their follow-up axillary reading. Tympanic thermometry resulted in a significantly higher temperature reading than the axillary method. Elevated tympanic temperatures were not predictive of oncoming fever or infection. Fevers were not missed when using the tympanic method. To prevent unnecessary medical intervention, it is recommended that mercury-in-glass thermometers verify elevated tympanic temperatures.     

Molecular motors: nature's nanomachines

Molecular motors are protein-based machines that convert chemical potential energy into mechanical work. This paper aims to introduce the non-specialist reader to molecular motors, in particular, acto-myosin, the prototype system for motor protein studies. These motors produce their driving force from changes in chemical potential arising directly from chemical reactions and are responsible for muscle contraction and a variety of other cell motilities.     

Identifying semantic equivalence for multi-document summarisation

We describe Semantic Equivalence and Textual Entailment Recognition, and outline a system which uses a number of lexical, syntactic and semantic features to classify pairs of sentences as “semantically equivalent”. We describe an experiment to show how syntactic and semantic features improve the performance of an earlier system, which used only lexical features. We also outline some areas for future work.     

Minority carrier effects in GaInP laser diodes

Using a top-contact window, we have observed emission from a direct-gap monitor layer placed at the interface between the p-cladding and contact layers of an AlGaInP laser diode when driven under forward bias, thereby providing direct evidence for minority carrier (electron) leakage in these devices. We have further shown that the leakage is due to both drift and diffusion and, using pulsed optical excitation of a device under bias, we have determined a value of 170±10 cm² V^-1 s^-1 for the mobility of minority carriers in the p-type cladding layer by a time-of-flight experiment. The data was analyzed using a simulation which takes account of the influence of recombination times in the well and monitor layer on the overall time response of the structure. The measured mobility corresponds to electron transport through the X-conduction band. We show that the drift component of the leakage current reduces the differential efficiency and is responsible for the decrease in external differential efficiency with increasing temperature. Because the leakage occurs by a mixture of drift and diffusion, the transit time does not decrease significantly with increasing drive current; however the impact of leakage on the modulation response is predicted to be very small unless the leakage becomes a substantial fraction of the total current     

Thermal study of selectively plated nickel sulfamate coatings

Nickel sulfamate solution was applied to mild steel substrates by the process of selective plating. The coated samples were heated to temperatures in the range of 50–1000 °C. Thermal analysis, X-ray diffraction and microscopy techniques were used to investigate the effect of secondary heating on the microstructure, mechanical properties and the composition of the surface coatings.     

Mapping, genomic organization and promoter analysis of the human prostate-specific membrane antigen gene

Prostate-specific membrane antigen (PSMA) is a 100 kDa type II transmembrane protein with folate hydrolase and NAALAdase activity. PSMA is highly expressed in prostate cancer and the vasculature of most solid tumors, and is currently the target of a number of diagnostic and therapeutic strategies. PSMA is also expressed in the brain, and is involved in conversion of the major neurotransmitter NAAG (N-acetyl-aspartyl glutamate) to NAA and free glutamate, the levels of which are disrupted in several neurological disorders including multiple sclerosis, amyotrophic lateral sclerosis, Alzheimer's disease and schizophrenia. To facilitate analysis of the role of PSMA in carcinoma we have determined the structural organization of the gene. The gene consists of 19 exons spanning approximately 60 kb of genomic DNA. A 1244 nt portion of the 5' region of the PSMA gene was able to drive the firefly luciferase reporter gene in prostate but not breast-derived cell lines. We have mapped the gene encoding PSMA to 11p11-p12, however a gene homologous, but not identical, to PSMA exists on chromosome 11q14. Analysis of sequence differences between non-coding regions of the two genes suggests duplication and divergence occurred 22 million years ago.     

Intrathecal clonidine and baclofen in the management of spasticity and neuropathic pain following spinal cord injury: a case study

Spasticity and pain are common disabling sequelae following spinal cord injury (SCI) and are often difficult to manage. The two problems are also not infrequently related. A variety of pharmacological and other approaches have been described for management of these problems in SCI. This case study reports a 32-year-old woman with an established incomplete C5 tetraplegia (anterior cord syndrome) who developed severe, intractable anal spasm following a hemorrhoidectomy, which persisted despite very good healing. This prevented evacuation of her bowels and resulted in severe rectal pain and episodes of autonomic dysreflexia. Attempts to modify the rate and mode of delivery of intrathecal baclofen through an existing programmable infusion pump failed to reduce anal sphincter spasm or improve symptoms. A right-sided pudendal block with lignocaine provided some relief. Clonidine was added to baclofen in the pump reservoir and both drugs were administered intrathecally in combination. This resulted in an immediate improvement in anal sphincter spasm and pain relief, allowing rapid reestablishment of her normal bowel pattern without need for any supplemental analgesia. It appears that intrathecal clonidine may have an important role in the treatment of spasticity, either as a single or an adjuvant agent, when intrathecal baclofen alone is ineffective or there is increasing tolerance to baclofen. Intrathecal clonidine may also prove useful in the management of intractable neuropathic pain.     

Optical radiation sensing properties of MnO/TeO/sub 2/ thin films

This work investigates the effects of /spl gamma/-rays on the optical properties of pure and mixed-oxide materials, namely MnO and TeO/sub 2/ for their possible application as thin film optical gamma radiation sensors. The values of the optical band gap E/sub opt/ were obtained in view of the Mott and Davis theory. All samples showed a decrease in E/sub opt/ with an increase in radiation dose to a certain level, which was found to be composition dependent. Films with 100 wt.% MnO exhibited the highest sensitivity to low doses of radiation, showing a strong decline in the optical band gap value from 0.64 eV before irradiation to 0.54 eV after a dose of 1.14 mGy. It was experimentally confirmed that both the sensitivity and the working dose range of radiation sensors can be controlled by the composition of the materials used.