Guillian-Barré syndrome in high tetraplegia following acute respiratory illness.

STUDY DESIGN: A case report of a Guillain-Barré syndrome (GBS) variant presenting in a patient with a high cervical spinal cord injury (SCI). OBJECTIVES: To illustrate a clinical presentation of GBS in an individual with chronic SCI. SETTING: Vancouver General Hospital, Vancouver, BC, Canada. METHODS/RESULTS: A 31-year-old man with chronic C2 AIS B (American Spinal Injury Association Impairment Scale) SCI and diaphragmatic pacing presented with respiratory failure with sepsis. His sepsis resolved with antibiotic therapy, but he continued to have autonomic instability and was unable to be weaned off his ventilator. Concurrently he developed flaccidity and facial diplegia. Investigations including nerve conduction studies and cerebrospinal fluid analysis prompted a diagnosis of acute motor-sensory axonal neuropathy, a variant of Guillian-Barré syndrome. Owing to ongoing autonomic instability, he was treated with intravenous immunoglobulin. His autonomic dysfunction resolved and he regained some facial muscle function, but 6 months post injury he remained dysphagic and required 24-h ventilator support. CONCLUSION: Careful neurological reassessment prompted the diagnosis of acute polyradiculoneuropathy following respiratory sepsis as the root cause of diaphragmatic pacer failure and autonomic instability.

The Canadian Neuromuscular Disease Registry 2010-2019: A Decade of Facilitating Clinical Research Througha Nationwide, Pan-NeuromuscularDisease Registry.

We report the recruitment activities and outcomes of a multi-disease neuromuscular patient registry in Canada. The Canadian Neuromuscular Disease Registry (CNDR) registers individuals across Canada with a confirmed diagnosis of a neuromuscular disease. Diagnosis and contact information are collected across all diseases and detailed prospective data is collected for 5 specific diseases: Amyotrophic Lateral Sclerosis (ALS), Duchenne Muscular Dystrophy (DMD), Myotonic Dystrophy (DM), Limb Girdle Muscular Dystrophy (LGMD), and Spinal Muscular Atrophy (SMA). Since 2010, the CNDR has registered 4306 patients (1154 pediatric and 3148 adult) with 91 different neuromuscular diagnoses and has facilitated 125 projects (73 academic, 3 not-for-profit, 3 government, and 46 commercial) using registry data. In conclusion, the CNDR is an effective and productive pan-neuromuscular registry that has successfully facilitated a substantial number of studies over the past 10 years.

Reversal of HIV drug resistance and novel strategies to curb HIV infection: the viral infectivity factor Vif as a target and tool of therapy.

Due to the high genetic variability of human immunodeficiency virus (HIV), treatment of AIDS (acquired immunodeficiency syndrome) patients with inhibitors of reverse trancriptase (RT) and drugs blocking the viral protease regularly results in the accumulation of drug resistant HIV variants and treatment failure. The sensitivity of clinically derived resistant HIV-1 strains to nucleotide RT inhibitors could be restored, however, in several laboratories by pharmacological depletion of the appropriate endogenous deoxynucleotide triphosphate (dNTP), and such a manipulation (induction of dCTP pool imbalance during reverse transcription in the presence of a non-nucleoside RT inhibitor) altered the mutation spectrum of the HIV-1 genome, resulting in a lower level of HIV resistance to certain drugs. The cytoplasmic single-stranded DNA cytidine deaminases APOBEC3G and APOBEC3F block HIV replication by introducing premature stop codons into the viral genome. We suggest that the resulting crippled, defective HIV (dHIV) variants could interfere with replication of "wild type" viruses and curbe disese progression in long term non-progressor individuals. Vif, an accessory protein encoded by HIV, counteracts APOBEC3G/F action. We speculate that small molecule inhibitors of Vif could permit lethal or sublethal mutagenesis of HIV genomes. We suggest that an artificial dHIV construct carrying a mutated vif gene (coding for a Vif protein unable to block APOBEC3G/F) could have a therapeutic effect as well in HIV infected individuals and AIDS patients.

Targeting of methotrexate-containing liposomes with a monoclonal antibody against human renal cancer.

The potential of monoclonal antibody-linked small unilamellar vesicles containing methotrexate [(MTX)SUVs] in cancer chemotherapy was investigated. (MTX)SUVs prepared by probe sonication [50 +/- 20 (SD) nm in diameter] were linked covalently to Dal K29 (an IgG1 monoclonal antibody against human renal cancer), normal mouse IgG, or a nonspecific mouse myeloma IgG1. After incubation with a human kidney cancer cell line, CaKi-1, for 2 h, Dal K29-linked (MTX)SUVs showed 6 and 8 times more binding to CaKi-1 cells than nonspecific mouse myeloma IgG1-linked (MTX)SUV or (MTX)SUVs unlinked. After incubation with Dal K29-linked ([3H]MTX)SUVs, a higher amount of radioactivity was associated with CaKi-1 cells at 37 degrees C than at 4 degrees C. Membrane immunofluorescence revealed aggregation and capping of Dal K29-linked SUVs around CaKi-1 cells after incubation at 37 degrees C for 2 h and endocytosis at 4 and 6 h. Electron microscopic examination confirmed the aggregation of Dal K29-linked SUVs on the surface of CaKi-1 cells and their presence in endocytic vesicles at 4 and 6 h. After incubation with Dal K29-linked gold containing SUVs at 37 degrees C, gold-containing SUVs were seen on the surface as well as inside endocytic vesicle of CaKi-1 cells at 2 and 4 h. A colony inhibition assay showed that Dal K29-linked (MTX)SUVs were 5 and 40 times more potent than Dal K29-MTX and equimolar amounts of free untrapped MTX in inhibiting the growth of the target CaKi-1 cells but were not toxic to a human melanoma line (that did not react with Dal K29).

Influence of lamotrigine on progression of early Huntington disease: a randomized clinical trial.

OBJECTIVE: To assess the efficacy of lamotrigine, a novel antiepileptic drug that inhibits glutamate release, to retard disease progression in Huntington disease (HD). BACKGROUND: Excitatory amino acids may cause selective neuronal death in HD, and lamotrigine may inhibit glutamate release in vivo. METHODS: A double-blinded, placebo-controlled study was conducted of 64 patients with motor signs of less than 5 years' duration who were randomly assigned to either placebo or lamotrigine and assessed at 0 (baseline), 12, 24, and 30 months. The primary response variable was total functional capacity (TFC) score. Secondary response variables included the quantified neurological examination and a set of cognitive and motor tests. Repeated fluorodeoxyglucose measurements of regional cerebral metabolism using PET also were included. RESULTS: Fifty-five patients (28 on lamotrigine, 27 on placebo) completed the study. Neither the primary response variable nor any of the secondary response variables differed significantly between the treatment groups. Both the lamotrigine and the placebo group deteriorated significantly on the TFC, in the lamotrigine group by 1.89 and the placebo group by 2.11 points. No effect of CAG size on the rate of deterioration could be detected. CONCLUSIONS: There was no clear evidence that lamotrigine retarded the progression of early Huntington disease over a period of 30 months. However, more patients on lamotrigine reported symptomatic improvement (53.6 versus 14.8%; p = 0.006), and a trend toward decreased chorea was evident in the treated group (p = 0.08). The study also identified various indices of disease progression, including motor tests and PET studies, that were sensitive to deterioration over time.

Inhibition of human renal cancer by monoclonal antibody targeted methotrexate-containing liposomes in an ascites tumor model.

The monoclonal antibody DAL K29 against a human renal cell carcinoma associated cell surface antigen was covalently linked to small unilamellar lipid vesicles (SUV) containing the antifolate, methotrexate (MTX), with full retention of antibody activity. In an ascites tumor model developed after intraperitoneal inoculation of 5 x 10(6) cells of the human kidney cancer line Caki-1 per pristane primed nude mouse, the DAL K29 linked MTX-containing SUV was a more potent tumor inhibitor (P less than 0.0005) than the drug or MAB alone, MTX-containing SUV, a mixture of DAL K29 and MTX-containing SUV or MTX-containing SUV linked to an isotype matched nontumor specific IgG.

Genetic subtypes of HIV type 1 in Hungary.

We examined the diversity of HIV-1 subtypes in 11 adults from Hungary, using the heteroduplex mobility assay (HMA) and DNA sequencing. HMA results showed that HIV-1 gp120 sequences from 10 patients were of subtype B, whereas 1 patient, infected in Africa, carried a subtype C strain. DNA sequencing confirmed the HMA results and revealed a high intrasubtype diversity in the C2V3 region of env in different clade B isolates, which suggests multiple introduction of subtype B to Hungary. This study shows that subtype B is the predominant HIV-1 clade in Hungary.

Temporal trends in antibody production in captive grey, harp and hooded seals to a single administration immunocontraceptive vaccine.

The temporal production of antibody to a single-administration immunocontraceptive vaccine, known to be immunocontraceptive in free-ranging female grey seals (Halichoerus grypus), was studied in captive grey seals, harp seals (Phoca groenlandica) and hooded seals (Cystophora cristata). The vaccine is based on liposome delivery of porcine zona pellucida antigens. When measured by antigen capture, the response of hooded and harp seals to the vaccine was similar to the response of grey seals. Determination of antibody production by ELISA with protein A, ELISA with rabbit anti-seal immunoglobulin sera and SDS-PAGE after affinity chromatography confirmed the similarity in response to the vaccine by grey and harp seals, but suggested lower titers in hooded seals. The vaccine produced titers in captive, juvenile grey and harp seals known to be immunocontraceptive in wild, adult grey seals.

Evidence for a long-lasting single administration contraceptive vaccine in wild grey seals.

A single-administration birth control vaccine based on liposome delivery of porcine zona pellucida antigens reduced pup production in grey seals (Halichoerus grypus) by about 90%. Anti-porcine zona pellucida titers of individual seals with two or more recaptures were variable but without a diminishing trend during the 5 year post-immunization period. Seals that produced at least one or more pups during the 2-5 year post-immunization period when the vaccine is fully effective, had an average anti-porcine zona pellucida titer of 5% of the reference serum. In contrast, the subset of seals that did not reproduce but were recaptured during the breeding season had an average titer of 31% of the reference serum. As measured by antibody titers and pup production, there were no differences in efficacy of the vaccine in 14-, 20- and 21-year-old female grey seals.

Liposomes as drug carriers for oral ulcers.

The aim of this study was to test the potential of liposomes as drug carriers to the ulcerated oral mucosa. Radioactive triamcinolone acetonide palmitate (3H-TRMAp) was encapsulated in large multilamellar lipid vesicles and served as the test lotion. 3H-TRMAp in solution served as control. Forty-six hamsters were divided into three groups. In group I, multiple confluent ulcers in both cheek pouches were treated by topical application. In group II, single ulcers on the cheeks were treated by intramucosal injection. In group III, multiple confluent ulcers were produced in the cheek pouch on one side, with a single ulcer in the contralateral cheek pouch; no drug was applied, and the tissues were prepared for histology. Hamsters were killed at three and 24 hours, respectively, after treatment. Pouches were divided into ulcerated and intact adjacent mucosa. Cheeks were divided into ulcerated mucosa and distant mucosa. Drug levels in the four mucosal portions as well as in the blood, liver, spleen, brain, and thalamic region were determined by radioactive tracer technique. At three hours, liposomal drug concentrations were lower than in control animals in the brain and the thalamic region. At 24 hours, liposomal drug values were higher than in control animals in the ulcerated mucosa and lower than in control animals in the thalamic region. Mean drug concentrations in the ulcerated mucosa were higher in group II than group I. The results parallel those of Mezei and Gulasekharam (1980, 1982); liposomes increase local and decrease systemic drug concentration.(ABSTRACT TRUNCATED AT 250 WORDS)

Electromyography of respiratory muscles in amyotrophic lateral sclerosis.

We reviewed the records of 52 amyotrophic lateral sclerosis (ALS) patients examined between 1995 and 2000 who had needle electromyography (EMG) of their respiratory muscles, including the diaphragm, at or near the time of their diagnosis. With respiratory function testing, patients with abnormal diaphragmatic EMG at diagnosis (Group 1, n=23) had significantly lower forced vital capacity (FVC), lower daytime arterial PO(2) and higher PCO(2) measurements (p<0.05) than patients with normal diaphragmatic EMG (Group 2, n=29). Twenty-eight percent of the patients without symptoms or signs of respiratory insufficiency at the time they were examined had an abnormal diaphragm EMG. Mean survival of Groups 1 and 2 were similar. However, sub-analysis of patients within each group, comparing those treated with non-invasive positive pressure ventilation (NIPPV) with those not treated, showed that treated patients in Group 1 (abnormal diaphragm EMG) survived significantly longer (p<0.05) than untreated patients. They also started NIPPV earlier than treated patients in Group 2. We conclude that respiratory muscle EMG was simply and safely performed on ALS patients at or around the time of diagnosis. The procedure can detect sub-clinical respiratory muscle dysfunction. The technique used for EMG of the respiratory muscles, its pitfalls and contraindications are also reviewed.

Motor system abnormalities in heterozygous relatives of a D90A homozygous CuZn-SOD ALS patient of finnish extraction.

Presently, 64 mutations in the gene encoding the enzyme CuZn-superoxide dismutase have been found in a small fraction of amyotrophic lateral sclerosis patients worldwide. All but one of these mutations show autosomal dominant inheritance. In Scandinavia, the D90A mutation is inherited as an autosomal recessive trait and patients have an easily recognizable characteristic phenotype with little variation among patients, even amongst different families. Importantly, all D90A heterozygous relatives of Scandinavian D90A homozygous patients have been reported as clinically unaffected. We have investigated a Canadian family of Finnish extraction in which the D90A homozygous proband developed ALS with the characteristic phenotype. Remarkably, two D90A heterozygous relatives show slight symptoms and signs of motor system involvement, suggesting that the final phenotype of an individual with a CuZn-superoxide dismutase mutation is shaped by the combination of the particular CuZn-SOD mutation, other polymorphic modifying genes elsewhere in the genome, stochastics and possible environmental factors.

Computer simulation studies of the fully solvated wild-type and mutated GnRH in extended and beta-turn conformations.

The conformational preference of the gonadotropin-releasing hormone (GnRH) and its Lys-8 mutant, studied earlier with a continuum model, was revisited using an explicit solvent model and thermodynamic integration to calculate the solvents contribution to the conformation-dependence of its free energy. In addition, the Proximity Criterion was used to further analyze the effects of conformational changes.

Monte Carlo computer simulation of the aqueous hydration of the glycine zwitterion at 25 degree C.

Monte Carlo computer simulation on a dilute aqueous solution of the glycine zwitterion are reported. The results are presented in terms of the Quasi-Component Distribution Functions (QCDF) of Ben Naim and partitioned into atomic and functional group contributions using the Proximity Criterion. The Proximity Criterion analysis has been extended to orientational properties and a new normalization procedure has been introduced for the radial distribution functions obtained by the Proximity Criterion. The solvation environment of the glycine zwitterion is found to contain, on the average, 14.4 water molecules out of which 3.2 belong to the ammonium group, 6.1 to the methylene group and 5.1 to the carboxyl group. The importance of the many-body statistical mechanical approach to hydration is emphasized by our finding that the configuration corresponding to the absolute minimum of the glycine zwitterion-water potential surface was found to have negligible statistical weight in the aqueous simulation.

Conformational space comparison of GnRH and lGnRH-III using molecular dynamics, cluster analysis and Monte Carlo thermodynamic integration.

The conformational space available to GnRH and lGnRH-III was compared using 5.2 ns constant temperature and pressure molecular dynamics simulations with explicit TIP3P solvation and the AMBER v. 5.0 force field. Cluster analysis of both trajectories resulted in two groups of conformations. Results of free energy calculations, in agreement with previous experimental data, indicate that a conformation with a turn from residues 5 through 8 is preferred for GnRH in an aqueous environment. By contrast, a conformation with a helix from residues 2 through 7 with a bend from residues 6 through 10 is preferred for lGnRH-III in an aqueous environment. The side chains of His2 and Trp3 in lGnRH-III occupy different regions of phase space and participate in weakly polar interactions different from those in GnRH. The unique conformational properties of lGnRH-III may account for its specific anti cancer activity.

Aqueous hydration of nucleic acid constituents: Monte Carlo computer simulation studies.

Monte Carlo computer simulations were performed on dilute aqueous solutions of thymine, cytosine, uracil, adenine, guanine, the dimethyl phosphate anion in the gauche-gauche conformation and a ribose and deoxyribose derivative. The aqueous hydration of each molecule was analysed in terms of quasi-component distribution functions based on the Proximity Criterion, and partitioned into hydrophobic, hydrophilic and ionic contributions. Color stereo views of selected hydration complexes are also presented. A preliminary discussion of the transferability of functional group coordination numbers is given. The results enable to comment on two current problems related to the hydration of nucleic acids: a) the theory of Dickerson and coworkers on the role of water in the relative stability of the A and B form of DNA and b) the idea of water bridges and filaments emerging from the computer simulation results on the hydration of DNA fragments by Clementi.

Monte Carlo studies on water in the dCpG/proflavin crystal hydrate.

The extensive water network identified in the crystallographic studies of the dCpG/Proflavin hydrate by Neidle, Berman and Shieh (Nature 288, 129, 1980) forms an ideal test case for a) assessing the accuracy of theoretical calculations on nucleic acid--water systems based on statistical thermodynamic computer simulation, and b) the possible use of computer simulation in predicting the water positions in crystal hydrates for use in the further refinement and interpretation of diffraction data. Monte Carlo studies have been carried out on water molecules in the unit cell of dCpG/proflavin, with the nucleic acid complex fixed and the condensed phase environment of the system treated by means of periodic boundary conditions. Intermolecular interactions are described by potential functions representative of quantum mechanical calculations developed by Clementi and coworkers, and widely used in recent studies of the aqueous hydration of various forms of DNA fragments. The results are analyzed in terms of hydrogen bond topology, hydrogen bond distances and energies, mean water positions, and water crystal probability density maps. Detailed comparison of calculated and experimentally observed results are given, and the sensitivity of results to choice of potential is determined by comparison with simulation results based on a set of empirical potentials.

Chemical modification of triamcinolone acetonide to improve liposomal encapsulation.

The 21-palmitate of triamcinolone acetonide was synthesized to aid in the liposomal encapsulation of the drug. Encapsulation efficiency of triamcinolone acetonide-21-palmitate was 85%, compared with 5% for the parent drug.

Intracellular delivery of drugs by liposomes containing P0 glycoprotein from peripheral nerve myelin into human M21 melanoma cells.

The effect of P0 protein (a cell adhesion molecule from avian peripheral nerve myelin) on the rate of interaction of liposomes with human M21 melanoma cells was investigated. Liposome uptake by the cells was quantitated using radioactive lipids and liposome-entrapped drugs under various conditions. Liposomes containing P0 protein and [14C]dipalmitoylphosphatidylcholine:cholesterol (10:1 molar ratio) had an interaction rate with M21 cells three times higher than control vesicles of the same lipid composition but without the protein after incubation at 37 or 4 degrees C. The presence of P0 protein could be detected on the surface of melanoma cells by immunofluorescence after incubation. Binding to the cell surface and endocytosis of P0 liposomes was suggested from the sensitivity of cell-associated proteoliposomes to trypsin, metabolic inhibitors, and low temperature. Liposomal encapsulation highly increased the association of model compounds [( 3H]methotrexate and [3H]inulin) with cells. The proteoliposomes appeared to be leaky in the incubation medium, which led to the delivery of a lower amount of drug into cells than could be expected from their initial drug content. The results suggest that the attachment of liposomes to the cell surface can increase their drug delivery potential, because the binding triggers endocytic processes or a juxtapositional temporary permeability increase of liposome and cellular membrane that can lead to the uptake of drug from liposomes.

In vivo method for monitoring polysorbate 85 effect on epidermal permeability.

An in vivo method of monitoring the rate of water desorption from human forearms, using "dry" nitrogen gas passed over approximately 1 cm-2 of skin was investigated with the aid of a commercial electrolytic moisture analyzer. The assembled apparatus was used to evaluate the differences in water loss rates from treated and untreated (control) forearms following surfactant application. The changes in the differences were also monitored after cessation of treatment, i.e., during the healing process. The apparatus provided an accurate, rapid, and painless method of monitoring relative water loss rates and, as such, could prove a useful tool in routine testing in experimental dermatology and cosmetology. The results confirm the earlier finding from an in vitro method with excised rabbit skin that the tested surfactant increases the permeability of the epidermis.