Does Alzheimer's disease begin in the brainstem?

Although substantial evidence indicates that the progression of pathological changes of the neuronal cytoskeleton is crucial in determining the severity of dementia in Alzheimer's disease (AD), the exact causes and evolution of these changes, the initial site at which they begin, and the neuronal susceptibility levels for their development are poorly understood. The current clinical criteria for diagnosis of AD are focused mostly on cognitive deficits produced by dysfunction of hippocampal and high-order neocortical areas, whereas noncognitive, behavioural and psychological symptoms of dementia such as disturbances in mood, emotion, appetite, and wake-sleep cycle, confusion, agitation and depression have been less considered. The early occurrence of these symptoms suggests brainstem involvement, and more specifically of the serotonergic nuclei. In spite of the fact that the Braak and Braak staging system and National Institutes of Aging - Reagan Institute (NIA-RI) criteria do not include their evaluation, several recent reports drew attention to the possibility of selective and early involvement of raphe nuclei, particularly the dorsal raphe nucleus (DRN), in the pathogenesis of AD. Based on these findings of differential susceptibility and anatomical connectivity, a novel pathogenetic scheme of AD progression was proposed. Although the precise mechanisms of neurofibrillary degeneration still await elucidation, we speculated that cumulative oxidative damage may be the main cause of DRN alterations, as the age is the main risk factor for sporadic AD. Within such a framework, beta-amyloid production is considered only as one of the factors (although a significant one in familial cases) that promotes molecular series of events underlying AD-related neuropathological changes.

The use of information theory and numerical taxonomy methods for evaluating the quality of thin-layer chromatographic separations of flavonoid constituents of Matricariae flos.

A methanol extract of Matricariae flos was analysed with regard to the flavonoid composition. Rational selection of a restricted set from eight chromatographic systems tested for the separation of these compounds is discussed. Series of mathematical techniques for the evaluation of solvents and solvent combinations in thin-layer chromatography of flavonoid constituents have been explored. The chromatographic systems are classified according to their mutual resemblance by numerical taxonomy techniques. The selection criterion in the groups, obtained by numerical taxonomy classification, is the information content or the discriminating power. The most suitable mobile phases for TLC separation of flavonoid constituents of Matricariae flos are: ethylacetate-methanol-water (75:15:0 v/v), ethylacetate-formic acid-water (80:10:10 v/v) and ethylacetate-formic acid-acetic acid-water (100:11:11:27 v/v).

[Carcinoma of the urinary bladder resembling lymphoepithelioma]. / Karcinom mokracnog mjehura slican limfoepiteliomu.

Lymphoepithelioma-like carcinoma of the bladder is rare and has only recently been described at this site. We report a case of lymphoepithelioma-like carcinoma of the urinary bladder in a 70-years old male patient who presented with painless hematuria lasting for one month. The patient underwent transurethral resection two times. Histopathologic diagnosis was transitional cell carcinoma. Histopathologic examination of the third biopsy showed tumor tissue with typical syncitial growth pattern of atypical, large, epitheloid cells with ill-defined cytoplasmic borders, prominent nucleoli and numerous mitoses. A prominent lymphocytic infiltrate was found as a component of the tumor. Immunohistochemistry showed positive reaction for cytokeratin and epithelial membrane antigen, and negative results for leukocyte common antigen, CD3, CD20, CD30, CD68 and PSA. The lymphoid infiltrate was an admixture of T and B cells. The tumor invaded the muscle wall. After last surgery the patient underwent chemotherapy by local application of Adriablastine. At present the patient is without recurrence 10 months after the last surgery.

["More is not better"--evaluation of toxicologic risks of the heavy metals, lead and cadmium, and the herbicides, linuron, fluazifop-P-butyl and cycloxydim in dried Chamomile flowers (Chamomilla recutita L. Rauschert)]. / "Vise nije bolje"--prilog procjeni toksikoloskog rizika teskih metala olova i kadmija te herbicida linuron, fluazifop-P-butyl i cycloxydim u osusenom cvijetu kamilice (Chamomilla recutita L. Rauschert).

Cadmium and all three enumerated herbicide residues in dried samples of industrially grown true chamomile were found to be above the suggested and accepted tolerance values. The results are discussed with regard to the current Croatian regulation and FAO/WHO recommendations on herbicides and to human toxicology risk assessment. The paper gives a critical evaluation of the herbicide overuse in agricultural practice and strongly discouraged such practice. The authors advocate prospective use of plants as natural indicators of environmental contamination and toxicological burden of the human food chain.