Stress load and neurodegeneration after gastrostomy tube placement in amyotrophic lateral sclerosis patients.

Dysphagia and progressive swallowing problems due to motoneuron death is one of amyotrophic lateral sclerosis (ALS) symptoms. Malnutrition and body weight loss result in immunological disturbances, fatigability and increase risk of secondary complications in ALS patients, percutaneous endoscopic gastrostomy tube (PEG) placement representing a well-recognized method for malnutrition correction and potentially increasing life expectancy. However, despite nutritional correction, occasional rapid neurological deterioration may develop after PEG placement. We have hypothesized that this decline can be a result of exteroceptive stress during PEG placement and promote neurodegeneration in ALS patients. Intravenous sedation may decrease stress during invasive procedures and it is safe during PEG placement in ALS patients. The aim of the study was comparing different PEG placement protocols of anesthesia (local anesthesia or local anesthesia plus intravenous sedation) in ALS from perspectives of stress load and neurological deterioration profile. During 1.5 years 94 ALS patients were admitted; gastrostomy was performed in 79 patients. After screening according to inclusion and exclusion criteria, 30 patients were included in the prospective consecutive study. All patients were divided in two groups, with local anesthesia and with combination of local anesthesia and intravenous sedation. Routine biochemical indices, neurodegeneration and stress markers were measured. The age of ALS patients was 61 ± 10 years; 20 patients were included at stage 4A and 10 at stage 4B (King's College staging). PEG was placed at average14 months after the diagnosis and 2.2 years after first symptoms. Mean ALS Functional Rating Scale-Revised was 27.8, mean forced vital capacity of lung 46.3% (19-91%). After one year of observation only 8 patients survived. Mean life duration after PEG was 5 months (5 days-20 months). Comparison of two PEG placement protocols did not reveal differences in survival time, stress load and inflammation level. Higher saliva cortisol levels, serum cortisol, glucose, C-reactive protein and interleukin-6 were detected after PEG placement, confirming considerable stress response. PEG is a stressful factor for ALS patients, PEG placement representing a natural model of exteroceptive stress. Stress response was detected as increased cortisol, C-reactive protein, interleukin-6, and glucose levels. Intravenous sedation did not increase the risk of PEG placement procedure, however, sedation protocol did not affect stress load.

Sedimentation stability and aging of aqueous dispersions of Laponite in the presence of cetyltrimethylammonium bromide.

This work discusses the sedimentation stability and aging of aqueous suspensions of Laponite in the presence of cetyltrimethylammonium bromide (CTAB). The concentration of Laponite was fixed at a constant level C(l)=2%wt, which corresponds to the threshold between equilibrium gel IG(1) and glass IG(2) states. The concentration of CTAB C(s) was within 0-0.3 %wt. In the presence of CTAB, the Laponite aqueous suspensions were unstable against sedimentation and separated into the upper and bottom layers (U and B layers, respectively). The dynamic light-scattering technique has revealed that addition of CTAB even at a rather small concentration, C(s)=0.0164 %wt (0.03 cation exchange capacity), induced noticeable changes in the aging dynamics of the U layer. It was explained by equilibration of CTAB molecules that were initially nonuniformly distributed between different Laponite particles. Accelerated stability analysis by means of analytical centrifugation with rotor speed ω=500-4000 rpm revealed three sedimentation regimes: continuous (I, C(s)<0.14 %wt), zonelike (II, 0.140.2%wt). It was demonstrated that the B layer was "soft" in the zonelike regime. The increase of ω resulted in its supplementary compressing and collapse of "soft" sediment above certain critical centrifugal acceleration. The physical nature of the observed behavior, accounting for enhancement of hydrophobic interactions between Laponite particles, is discussed.

Identification of a locus on chromosome 14q for idiopathic basal ganglia calcification (Fahr disease).

Idiopathic basal ganglia calcification (IBGC) is a neurodegenerative syndrome that is associated with a variety of movement disorders and neurobehavioral and cognitive manifestations. Despite numerous clinical, pathological, and biochemical investigations, its etiology remains unknown. We have identified a multigenerational family with dominantly inherited IBGC and, in 24 members of this family, performed a whole-genome scan using polymorphic microsatellite markers to identify the first chromosomal locus for this disorder (IBGC1). A maximum two-point LOD score of 3.37 was obtained at marker D14S1014, and a maximum multipoint LOD score of 4.95 was obtained between D14S75 and D14S306. The minimal haplotype shared by affected patients extended over a 17.1-cM region bounded by D14S70 and D14S66, which is potentially further narrowed to a 13.3-cM region by a recombination observed in a patient with probable affected status. The age at onset appeared to be decreasing by an average of >20 years with each transmission, which is consistent with genetic anticipation.

From genotype to phenotype: a clinical pathological, and biochemical investigation of frontotemporal dementia and parkinsonism (FTDP-17) caused by the P301L tau mutation.

Frontotemporal dementia is a heterogeneous, often inherited disorder that typically presents with the insidious onset of behavioral and personality changes. Two genetic loci have been identified and mutations in tau have been causally implicated in a subset of families linked to one of these loci on chromosome 17q21-22. In this study, linkage analysis was performed in a large pedigree, the MN family, suggesting chromosome 17q21-22 linkage. Mutational analysis of the tau coding region identified a C-to-T change in exon 10 that resulted in the conversion of proline to a leucine (P301L) that segregated with frontotemporal dementia in this family. The clinical and pathological findings in the MN family emphasize the significant overlap between Pick's disease, corticobasal degeneration, and frontotemporal dementia and challenge some of the current dogma surrounding this condition. Pathological studies of two brains from affected members of Family MN obtained at autopsy demonstrate numerous tau-positive inclusions that were most prominent in the frontal lobes, anterior temporal lobes, and brainstem structures, as well as Pick-like bodies and associated granulovacuolar degeneration. These Pick-like bodies were observed in 1 patient with motor neuron disease. Because exon 10 is present only in tau mRNA coding for a protein with four microtubule binding repeats (4R), this mutation should selectively affect 4Rtau isoforms. Indeed, immunoblotting demonstrated that insoluble 4Rtau is selectively aggregated in both gray and white matter of affected individuals. Although there was significant pathological similarity between the 2 cases, the pattern of degenerative changes and tau-positive inclusions was not identical, suggesting that other genetic or epigenetic factors can significantly modify the regional topology of neurodegeneration in this condition.