Experimental axonopathy induced by immunization with campylobacter jejuni lipopolysaccharide from a patient with guillain‐barré syndrome

Campylobacter jejuni (C. jejunj) infection is the most common antecedent in the axonal variant of Guillain‐Barré syndrome (GBS). Antibodies against nerve gangliosides found in GBS patients recognize cross‐reactive epitopes in the lipopolysaccharide (LPS) of C. jejuni. This led to the molecular mimicry hypothesis of GBS. We immunized eleven rabbits with a LPS extracted from HS:19 C. jejuni strain isolated from a patient with GBS and complete Freund's adjuvant (CFA)(group I). In a second experiment we immunized seven rabbits with LPS, CFA and keyhole limpet hemocyanin (KLH)(group II). All group I rabbits developed high titers of anti‐LPS, anti‐GM1, anti‐GD1b antibodies and lower titers of anti‐GD1a. One rabbit, 50 days after initial inoculation, showed tremor and weakness. All rabbits of group II developed high titres of antiganglioside antibodies and six animals showed weakness 59–113 days after initial inoculation. Two rabbits died. Pathology showed mild to moderate, tendentially grouped, axonal degeneration in sciatic nerves of four out of five animals. Control rabbits of group I (immunized with CFA only) did not develop antibodies, controls of group II (immunized with CFA + KLH) developed low titers of IgG anti‐GM1. None developed neurological signs or showed axonal degeneration. C. jejuni LPS is a potent B‐cell stimulator capable to induce a strong antiganglioside response in rabbits. However, to induce the neuropathy is crucial to employ KLH, a glycoprotein known to stimulate both humoral and cellular responses. This animal model reproduces the pathogenetic process hypothesized in axonal GBS with antiganglioside antibodies post C. jejuni infection.     

Effect of voice rehabilitation on oral communication of Parkinson's disease patients

Voice and speech disorders are common in Parkinson's disease patients and may lead to social isolation. We employed routine clinical voice therapy measures to evaluate the effect of voice rehabilitation. Twenty patients with a stable drug regimen participated in this study. The patients were assessed before and after a program of voice rehabilitation consisting of 13 group therapy sessions during 1 month, with emphasis on the increase in laryngeal sphincteric activity. Voice rehabilitation produced an increase in maximal phonation times, decrease in the values of s/z ratio and air flow, increase in vocal intensity, decrease in the complaints of weak and strained-strangled voice and monotonous and unintelligible speech and elimination of complaints of swallowing alterations. These data indicate a greater glottic efficiency after voice rehabilitation reflecting a more functional oral communication.     

Anaerobic contribution to the time to exhaustion at the minimal exercise intensity at which maximal oxygen uptake occurs in elite cyclists, kayakists and swimmers

Using 23 elite male athletes (8 cyclists, 7 kayakists, and 8 swimmers), the contribution of the anaerobic energy system to the time to exhaustion (t _lim) at the minimal exercise intensity (speed or power) at which maximal oxygen uptake (V˙O_{2 max}) occurs (I _{V˙O2 max}) was assessed by analysing the relationship between the t _lim and the accumulated oxygen deficit (AOD). After 10-min warming up at 60% of V˙O_{2 max}, the exercise intensity was increased so that each subject reached his I _V˙O2max in 30?s and then continued at that level until he was exhausted. Pre-tests included a continuous incremental test with 2?min steps for determining the I _V˙O2max and a series of 5-min submaximal intensities to collect the data that would allow the estimation of the energy expenditure at I _V˙O2max . The AOD for the t _lim exercise was calculated as the difference between the above estimation and the accumulated oxygen uptake. The mean percentage value of energy expenditure covered by anaerobic metabolism was 15.2 [(SD 6)%, range 8.9–24.1] with significant differences between swimmers and kayakists (16.8% vs 11.5%, P≤0.05) and cyclists and kayakists (16.4% vs 11.5%, P≤0.05). Absolute AOD values ranged from 26.4?ml?·?kg^?1 to 83.6?ml?·?kg^?1 with a mean value of 45.9 (SD 18)?ml?·?kg^?1. Considering all the subjects, the t _lim was found to have a positive and significant correlation with AOD (r?=?0.62, P≤0.05), and a negative and significant correlation with V˙O_{2 max} (r?=??0.46, P≤0.05). The data would suggest that the contribution of anaerobic processes during exercise performed at I _V˙O2max should not be ignored when t _lim is used as a supplementary parameter to evaluate specific adaptation of athletes.     

Problems arising in correlating clinical and molecular data in myotonic dystrophy

The number of copies of CTG trinucleotide repeats in the myotonic dystrophy gene correlates to a certain degree with the clinical symptoms in the patient. Routine molecular analysis of myotonic dystrophy is performed on peripheral blood cells, detecting the size of the expansion in leukocytes. However, in some cases somatic mosaicism is responsible for the presence of differently sized myotonic dystrophy alleles in different tissues of the same affected individual, complicating diagnosis and prognosis. Here we report two cases in which the correlation between molecular and clinical analysis performed with standard procedures posed some interpretative problems. The first individual was affected by an atypical clinical picture of myotonic dystrophy, the severity of which was not correlated with the low number of triplet repeats detected in his leukocyte DNA. The second case illustrates a prognostic problem in the presence of a low degree expansion in leukocytes. These examples outline the limits of standard molecular and clinical analysis in myotonic dystrophy.