Rare myelin protein zero sequence variant in late onset CMT1B

Myelin protein zero (MPZ) mutations cause demyelinating neuropathies that range from severe neonatal to milder adult forms. We report a 65-year-old woman with slowly progressive leg weakness starting at 47. Examination revealed distal weakness and atrophy in all extremities, impaired light touch in both feet and pin perception to proximal calves, absent leg reflexes, and unsteady gait. Electrodiagnostic studies revealed a severe sensorimotor polyneuropathy with conduction velocities of 25 m/s - to normal. The conduction velocities in the upper 20's were seen in lower extremities with severe reduction of the corresponding compound muscle action potential amplitudes. She had a MPZ mutation with A-C transversion (nucleotide: 116, codon: 10, histidine-to-proline). Her sister has an identical mutation, with high arches, distal leg weakness, decreased vibration sensation in toes and ankle areflexia. Nerve conduction studies revealed a moderate-severe sensorimotor polyneuropathy with nerve conduction velocities of 36 m/s - to normal. Their mother had an abnormal gait and conduction velocities of 29-30 m/s. A third sister is clinically and genetically unaffected. One report has previously described four patients with this mutation with similar clinical and electrodiagnostic features. In patients tested for possible CMT, the frequency of MPZ His-Pro codon 10 substitutions was 0.11% (27 of 24,076 alleles).     

Acute sublethal global hypoxia induces transient increase of GAP-43 immunoreactivity in the striatum of neonatal rats

We assessed immunoreactivity (IR) in the cerebral cortex (CC), hippocampus (Hipp), and striatum (ST) of a growth-associated protein, GAP-43, and of proteins of the synaptic vesicle fusion complex: VAMP-2, Syntaxin-1, and SNAP-25 (SNARE proteins) throughout postnatal development of rats after submitting the animals to acute global postnatal hypoxia (6.5% O(2), 70 min) at postnatal day 4 (PND4). In the CC only the IR of the SNARE protein SNAP-25 increased significantly with age. The hypoxic animals showed the same pattern of IR for SNAP-25, although with lower levels at PND11, and also a significant increase of VAMP-2. SNAP-25 (control): PND11 P < 0.001 vs. PND18, 25, and 40, SNAP-25 (hypoxic): P < 0.001 vs. PND18, 25, and 40; VAMP-2 (hypoxic): P < 0.05 PND11 vs. PND18, and P < 0.01 vs. PND25 and PND40; one-way ANOVA and Bonferroni post-test. In the Hipp, SNAP-25 and syntaxin-1 increased significantly with age, reaching a plateau at PND25 through PND40 in control animals (one-way ANOVA: syntaxin-1: P = 0.043; Bonferroni: NS; SNAP-25: P = 0.013; Bonferroni: P < 0.01 PND11 vs. PND40). Hypoxic rats showed higher levels of significance in the one-way ANOVA than controls (syntaxin-1: P = 0.009; Bonferroni: P < 0.05 PND11 vs. PND25 and P < 0.001 PND11 vs. PND40). In the ST, GAP-43 differed significantly among hypoxic and control animals and the two-way ANOVA revealed significant differences with age (F = 3.23; P = 0.037) and treatment (F = 4.84; P = 0.036). VAMP-2 expression also reached statistical significance when comparing control and treated animals (F = 6.25, P = 0.018) without changes regarding to age. Elevated plus maze test performed at PND40 indicated a lower level of anxiety in the hypoxic animals. At adulthood (12 weeks) learning, memory and locomotor abilities were identical in both groups of animals. With these results, we demonstrate that proteins of the presynaptic structures of the ST are sensitive to acute disruption of homeostatic conditions, such as a temporary decrease of the O(2) concentration. Modifications in the activity of these proteins could contribute to the long term altered responses to stress due to acute hypoxic insult in the neonatal period.     

Irbesartan-mediated reduction of renal and cardiac damage in insulin resistant JCR : LA-cp rats

Background and purpose:

Angiotensin II receptor antagonists (ARBs), originally developed for antihypertensive properties, have pleiotropic effects including direct vascular actions. We tested the hypothesis that the ARB irbesartan would be effective against micro- and macrovascular complications of the prediabetic metabolic syndrome using the obese, insulin-resistant JCR : LA-cp rat that exhibits micro- and macrovascular disease with ischaemic myocardial lesions and renal disease.

Experimental approach:

Obese male rats were treated with irbesartan (30 mg·kg⁻¹·day⁻¹, incorporated into chow) from 12 to 25 weeks of age.

Key results:

Irbesartan treatment caused no change in food intake or body weight. Fasting glycaemic control of the JCR : LA-cp rats was marginally improved, at the expense of increased plasma insulin levels (∼50%). Fasting plasma triglycerides were marginally reduced (∼25%), while cholesterol concentrations were unchanged. Elevated concentrations of adiponectin, monocyte chemotactic protein-1 and plasminogen activator inhibitor-1 were reduced along with severity of glomerular sclerosis. Macrovascular dysfunction (aortic hypercontractile response to noradrenergic stimulus and reduced endothelium-dependent relaxation) was improved and frequency of ischaemic myocardial lesions reduced (62%).

Conclusions and implications:

Irbesartan reduces markers of inflammation and prothombotic status, improves macrovascular function and reduces glomerular sclerosis and myocardial lesions in a model of the metabolic syndrome. Unlike pharmaceutical agents targeted on metabolic dysfunction, irbesartan reduced end-stage disease without major reduction of plasma lipids or insulin. The protective effects appear to be secondary to unknown intracellular mechanisms, probably involving signal transduction pathways. Understanding these would offer novel pharmaceutical approaches to protection against cardiovascular disease.     

Symptoms and behavior problems of adolescents and adults with autism: effects of mother-child relationship quality, warmth, and praise

Using a cross-lagged panel design, we investigated the impact of positive family processes on change in autism symptoms and behaviors. A sample of 149 co-residing mothers and their adolescent or adult child with autism was drawn from a large, longitudinal study. Maternal warmth and praise were measured using coded speech samples in which mothers talked about their son or daughter. A high level of relationship quality was associated with subsequent reductions in internalizing and externalizing problems as well as reductions in impairments in social reciprocity and repetitive behaviors. Maternal warmth and praise were also related to symptom abatement in the repetitive behaviors domain.     

Sublingual hyoscyamine spray as premedication for colonoscopy: a randomized double-blinded placebo-controlled trial

BACKGROUND: Colonic motility and spasm during colonoscopy may affect duration and quality of the examination as well as patient comfort during and after the procedure. Previous studies assessing the utility of antispasmodic agents in colonoscopy demonstrated conflicting results. The aim of this study was to determine the effect of sublingual hyoscyamine spray (IB-Stat, Inkine Pharmaceutical) on the performance of colonoscopy. METHODS: One hundred patients undergoing elective colonoscopy were randomized in a double-blind study to receive .25 mg sublingual hyoscyamine spray (n = 50: 25 men and 25 women, mean age 60) or placebo spray (n = 50: 23 men and 27 women, mean age 56) 15 to 30 minutes before the procedure. Parameters measured included time required to reach the cecum, total procedure time, endoscopist perception of colonic motility and difficulty of the procedure, and patient assessment of discomfort after the procedure. The latter parameters were measured using a 100-mm visual analog scale. A single endoscopist performed all of the procedures. RESULTS: After adjustment for age, procedural difficulty scores and colonic motility scores were significantly lower in the hyoscyamine group compared with placebo (differences of 5.589 mm [P = .047] and 5.685 mm [P = .040], respectively). Mean time to cecal intubation and percentage of patients with discomfort were slightly lower in the hyoscyamine group (5.68 minutes/48%) compared with placebo (5.92 minutes/57.1%), although the differences were not statistically significant (P = .57 and P = .36, respectively). CONCLUSIONS: Procedural difficulty and colonic motility scores were significantly lower in subjects who received sublingual hyoscyamine before colonoscopy.     

Efficacy of cannabidiol in convulsive and nonconvulsive seizure types associated with treatment-resistant epilepsies in the Expanded Access Program

The cannabidiol (CBD) Expanded Access Program (EAP), initiated in 2014, provided CBD (Epidiolex) to patients with treatment-resistant epilepsy (TRE). In the final pooled analysis of 892 patients treated through January 2019 (median exposure = 694 days), CBD treatment was associated with a 46%–66% reduction in median monthly total (convulsive plus nonconvulsive) seizure frequency. CBD was well tolerated, and adverse events were consistent with previous findings. We used pooled EAP data to investigate the effectiveness of add-on CBD therapy for individual convulsive seizure types (clonic, tonic, tonic–clonic, atonic, focal to bilateral tonic–clonic), nonconvulsive seizure types (focal with and without impaired consciousness, absence [typical and atypical], myoclonic, myoclonic absence), and epileptic spasms. CBD treatment was associated with a reduction in the frequency of convulsive seizure types (median percentage reduction = 47%–100%), and nonconvulsive seizure types and epileptic spasms (median percentage reduction = 50%–100%) across visit intervals through 144 weeks of treatment. Approximately 50% of patients had ≥50% reduction in convulsive and nonconvulsive seizure types and epileptic spasms at nearly all intervals. These results show a favorable effect of long-term CBD use in patients with TRE, who may experience various convulsive and nonconvulsive seizure types. Future controlled trials are needed to confirm these findings.     

Inaccuracies in patient medical histories

Of patients who completed the same medical history questionnaire twice within a certain time period, 66% had at least 1 significant omission in their history. Consideration is given to the merits of a national medical history computerized database.