Seated postural neck and trunk reactions to sideways perturbations with or without a cognitive task.

Driving on irregular terrain will expose the driver to sideways mechanical shocks or perturbations that may cause musculoskeletal problems. How a cognitive task, imposed on the driver, affects seated postural reactions during perturbations is unknown. The aim of the present study was to investigate seated postural reactions in the neck and trunk among healthy adults exposed to sideways perturbations with or without a cognitive task. Twenty-three healthy male subjects aged 19-36 years, were seated on a chair mounted on a motion system and randomly exposed to 20 sideways perturbations (at two peak accelerations 5.1 or 13.2m/s(2)) in two conditions: counting backwards or not. Kinematics were recorded for upper body segments using inertial measurement units attached to the body and electromyography (EMG) was recorded for four muscles bilaterally in the neck and trunk. Angular displacements (head, neck, trunk and pelvis) in the frontal plane, and EMG amplitude (normalised to maximum voluntary contractions, MVC) were analysed. The cognitive task provoked significantly larger angular displacements of the head, neck and trunk and significantly increased EMG mean amplitudes in the upper neck during deceleration, although 10% of MVC was never exceeded. A cognitive task seems to affect musculoskeletal reactions when exposed to sideways perturbations in a seated position.

Mycotoxins in crude building materials from water-damaged buildings.

We analyzed 79 bulk samples of moldy interior finishes from Finnish buildings with moisture problems for 17 mycotoxins, as well as for fungi that could be isolated using one medium and one set of growth conditions. We found the aflatoxin precursor, sterigmatocystin, in 24% of the samples and trichothecenes in 19% of the samples. Trichothecenes found included satratoxin G or H in five samples; diacetoxyscirpenol in five samples; and 3-acetyl-deoxynivalenol, deoxynivalenol, verrucarol, or T-2-tetraol in an additional five samples. Citrinine was found in three samples. Aspergillus versicolor was present in most sterigmatocystin-containing samples, and Stachybotrys spp. were present in the samples where satratoxins were found. In many cases, however, the presence of fungi thought to produce the mycotoxins was not correlated with the presence of the expected compounds. However, when mycotoxins were found, some toxigenic fungi usually were present, even if the species originally responsible for producing the mycotoxin was not isolated. We conclude that the identification and enumeration of fungal species present in bulk materials are important to verify the severity of mold damage but that chemical analyses are necessary if the goal is to establish the presence of mycotoxins in moldy materials.

Characterization of Hafnia alvei by biochemical tests, random amplified polymorphic DNA PCR, and partial sequencing of 16S rRNA gene.

Hafnia alvei strains which possess the attachment-effacement gene (eaeA) may have clinical importance as new diarrhea-causing pathogens and should therefore be differentiated from other H. alvei strains. We characterized diarrheal H. alvei strains, which were positive in the PCR test for the eaeA gene, using biochemical tests not routinely used for identification of members of the family Enterobacteriaceae, and compared them with eaeA-negative strains isolated from different clinical and nonclinical sources to find characteristics useful for identification. Random amplified polymorphic DNA (RAPD)-PCR and partial sequencing of the 16S rRNA gene were utilized to study the genetic diversity of the isolates. The eaeA-positive strains were found to have many characteristic biochemical properties. Negative reactions in the 2-ketogluconate and histidine assimilation tests and a positive reaction in the 3-hydroxybenzoate assimilation test may be useful in routine diagnostics. Nearly identical RAPD-PCR profiles and identical 353-bp fragments of the 16S rRNA genes indicated little genetic diversity among the eaeA-positive strains. The low level of homology (92%) in the partial 16S rRNA genes of eaeA-positive and -negative H. alvei strains raises questions about the taxonomic positioning of eaeA-positive H. alvei.

Characterization of melatonin binding to the anteroventral and anterodorsal thalamic nuclei of the rat.

Binding of 2-[125I]melatonin to the anteroventral and anterodorsal nuclei of the rat limbic thalamus was analyzed with in vitro autoradiography. In both nuclei the binding was of high affinity (Kd values 24-41 pM) and was competed with by nanomolar concentrations of 6-hydroxymelatonin. Kd values were in the same range as those reported for other high-affinity binding sites in the brain. Bmax values were 0.68-2.99 fmol/mg protein. The results suggest that some effects of melatonin are mediated via the limbic thalamus.

Melatonin binding to the anteroventral and anterodorsal thalamic nuclei in the rat.

Pineal melatonin is a putative humoral coordinator of various circadian body rhythms. Rather few loci in the brain contain such a density of melatonin receptors that specific binding can be demonstrated by autoradiography. In this study we measured, using in vitro receptor autoradiography, displaceable binding of iodo-melatonin to the anteroventral and anterodorsal thalamic nuclei of Wistar rats (0.6-1.4 fmol/mg protein at 100 pM ligand concentration). These nuclei of the limbic system have direct connections with the retina and they participate in learning and memory functions.

Short Nissl staining for incubated cryostat sections of the brain.

Nissl stain often binds poorly to cryostat sections which have been incubated in solutions of radiolabeled ligands. Such incubation is used in receptor autoradiography of the brain when using the in vitro method. We have developed a rapid (16 min) modification of Nissl staining for sections that bind stain poorly, e.g., incubated sections. The method stains well sections which cannot be stained with other rapid Nissl staining methods.

A cheap, calibrated photographic method for the screening of X-ray film autoradiographs.

This report describes the use of a calibrated photographic method for the screening of X-ray film autoradiographs. In the method the autoradiographic film is contact printed onto photographic film of high contrast, and the latter is contact printed onto photographic paper of suitable contrast. Special features of e.g. deoxyglucose-autoradiographs are thus visualized. The method is inexpensive, and it can be used as a complement to densitometric point measurements of X-ray film autoradiographs.

Overstimulation, occipital/somesthetic cerebral cortical depth, and cortical asymmetry in mice.

It was hypothesized on theoretical grounds that sensory multidimensional overstimulation (stress) during development might not yield increased cerebral cortical depth, as has been found for enriched rearing conditions. We found that such overstimuliation in growing mice resulted in a low occipital/somesthetic cortical depth ratio in comparison to EC-stimulated mice (EC, enriched conditions). It is unclear whether this is due to small occipital or large somesthetic cortical depth. Principal-component analytic techniques indicate a complicated interaction during development involving sex, environmental condition, and cortical asymmetry.