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Precise Cause (precise + cause)
Selected AbstractsCondition Known as "Dark Rings Under the Eyes" in the Japanese Population is a Kind of Dermal Melanocytosis Which can be Successfully Treatedby Q-Switched Ruby LaserDERMATOLOGIC SURGERY, Issue 6 2006SHINICHI WATANABE MD BACKGROUND In general, dark rings under the eyes are believed to be a phenomenon caused mainly by physiological change because of their daily fluctuation. Medically speaking, the precise cause or pathogenesis of dark rings is unknown, and this condition has not been clearly defined. In our experience, the dark rings associated with conventional nevus of Ota can be successfully treated with Q-switched ruby laser (QSRL). OBJECTIVE This study was conducted to clarify the nature of dark rings under the eyes and to determine the efficacy of QSRL. PATIENTS AND METHODS Fifty-four patients who received a biopsy for pigment macules of the face were retrieved, and of that number 12 patients with bilateral homogeneous pigment macule on suborbital regions were selected for study of the dark rings. Of those patients, the histology and the efficacy of QSRL were evaluated retrospectively. RESULTS Histologically, all 12 patients indicated dermal melanocytosis, which was confirmed by the Masson-Fontana silver stain and staining against S100. In five patients who received QSRL therapy two times or more, the clinical improvement of two patients was scored as good (40,69%), and two other patients as excellent (>70% clearance). CONCLUSIONS We speculate that so-called dark rings under the eyes in the Japanese population is a kind of dermal melanocytosis which can be successfully treated by QSRL. [source] The pathogenesis of cell death in Parkinson's disease , 2007MOVEMENT DISORDERS, Issue S17 2007C. Warren Olanow MD Abstract A number of factors have been implicated in the pathogenesis of cell death in Parkinson's disease (PD). These include oxidative stress, mitochondrial dysfunction, inflammation, excitotoxicity, and apoptosis. While the precise pathogenic mechanism leading to neurodegeneration in PD is not known, there is considerable evidence suggesting that cell death occurs by way of a signal-mediated apoptotic process. PD is also characterized by intracellular proteinaceous inclusions or Lewy bodies. Proteolytic stress arises as a consequence of the excessive production of misfolded proteins, which exceed the capacity of the ubiquitin-proteasome system to degrade them. Recent genetic and laboratory studies support the possible relevance of proteolytic stress to both familial and sporadic forms of PD. Postmortem studies have shown that in the SNc of sporadic PD patients there are reduced levels of the alpha subunit of the 20S proteasome and reduced proteolytic enzyme activities. A determination as to the precise cause of cell death in PD, and the identification of specific targets for the development of drugs that might modify disease progression is one of the most critical goals in PD research. It is anticipated that over the next few years there will be a flurry of scientific activity examining the mechanism of cell death and putative neuroprotective interventions. © 2007 Movement Disorder Society [source] Is there a relationship between herbaceous species richness and buffel grass (Cenchrus ciliaris)?AUSTRAL ECOLOGY, Issue 5 2005JANICE JACKSON Abstract Cenchrus ciliaris L. (buffel grass) (Poaceae) is recognized as one of Australia's most serious environmental weeds. This introduced grass has been associated with loss of native species and alteration of fire regimes. However, it is also highly valued as a pasture species for arid and semiarid zones and its weed status is highly controversial. Quantitative studies are needed to determine its ecological effects. The relationship between C. ciliaris and herbaceous species richness was investigated in two studies at a range of scales up to 64 m2 in open woodlands in the Dalrymple Shire, north-eastern Queensland. In the first study, the herbaceous species composition of sites with and without C. ciliaris were compared. Cenchrus ciliaris -dominated sites had fewer herbaceous species than non- C. ciliaris sites at all scales investigated and this pattern was found for the major plant groups (perennial grasses, legumes and other forbs) present. In the second study, the relationship between varying levels of C. ciliaris biomass and species richness was investigated. The relationship between varying levels of a dominant native grass, Bothriochloa ewartiana (Domin) C.E. Hubb. (Poaceae), and species richness was also determined for comparison with the C. ciliaris biomass-richness relationship. In this study, species richness was negatively associated with increasing C. ciliaris biomass at some scales and it appeared that C. ciliaris had a greater effect on richness than B. ewartiana. The negative association between C. ciliaris and species richness is consistent with the view that invasion by C. ciliaris poses a threat to biodiversity. However, the precise cause of the relationship has yet to be determined. [source] A Festschrift in Honor of Professor R.W. SmithellsBIRTH DEFECTS RESEARCH, Issue 4 2009Mary Seller This issue of Birth Defects Research Part A: Clinical and Molecular Teratology, comprises a Festschrift, a tribute to Professor R. W. (Dick) Smithells (1924-2002). In the 1970s, Dick initiated a study on the prevention of neural tube defects (NTD) by periconceptional multivitamin and folic acid supplementation of ,at risk' women. A significantly positive result was obtained,the first time that the primary prevention of any congenital malformation had ever been achieved. This important discovery stimulated an explosion of similar and related studies, and over the years, an extension of research into many closely allied but disparate fields. The papers in this Festschrift tell some of this story. However, the story itself has, as yet, no ending, because despite Dick's pioneering work and all our accumulated knowledge, the precise cause of NTD, and its mechanism, remains unknown. The authors contributing to this issue dedicate their work to the memory of Dick, and together with many other scientists, doctors and patients worldwide acknowledge and pay homage to his inspiration, industry and foresight. Birth Defects Research (Part A), 2009. © 2009 Wiley-Liss, Inc. [source] Myeloma kidney with isolated tubulointerstitial light chain deposition in a renal allograftCLINICAL TRANSPLANTATION, Issue 6 2009S. Balamuthusamy Abstract:, Myeloma kidney and myeloma-associated renal disorders including light chain deposition disease can occur as recurrent or de novo disease in renal allografts. These kidney disorders usually manifest with worsening allograft function and proteinuria. Identification of the precise cause of kidney disorder often requires kidney biopsy and demonstration of monoclonal light chains in the kidney. Here, we present an unusual case of light chain nephropathy in a living-related kidney transplant recipient involving light chain crystallization in the proximal tubule occurring within less than three months after transplant. The etiology of renal failure prior to transplant in our patient is not clear. To the best of our knowledge, the ultrastructural changes seen in our patient have not been described in literature previously. Our patient was treated with steroids, which resulted in short-term improvement in allograft dysfunction. [source] Demography of lions in relation to prey and habitat in the Maasai Mara National Reserve, KenyaAFRICAN JOURNAL OF ECOLOGY, Issue 2 2002J. O. Ogutu Abstract We studied lion demography in the Maasai Mara National Reserve between September 1990 and April 1992, with a special emphasis on the spatial and seasonal variation in demographic characteristics. Lion density (0.2,0.4 lions km,2) and pride size (range 8,48) were high because of a high resident prey biomass (10 335 kg km,2) augmented by migrant prey to 26 092 kg km,2 in the dry season. Overall, their sex ratio was almost at parity and varied neither spatially nor seasonally. Sex ratio was even among subadults but skewed toward males and females among cubs and adults, respectively. This implies an increasing differential mortality of males with age through subadulthood. The age ratio varied seasonally because of a birth peak in March,June and an influx of subadults into the reserve during July,August, coincident with increases in migrant prey. The birth peak was apparently preceded by another peak in mating activity falling between November and May. Further research should investigate the precise causes of the biased cub sex ratio, low lion density in the Mara Triangle and the higher ratio of subadults in Musiara than in the Mara Triangle or Sekenani. Résumé Nous avons étudié la démographie des lions dans la Réserve Nationale de Masai Mara entre septembre 1990 et avril 1992, en insistant particulièrement sur les variations spatiales et saisonnières des caractéristiques démographiques. La densité des lions (0.2,;0.4 lions/km2) et la taille des troupes (de 8 à 48) étaient élevées en raison de la forte biomasse des proies résidentes (10 335 kg/km2), portée à 26 092 kg/km2 en saison sèche par les proies migratrices. En général, le sex-ratio était à peu près égal et ne variait ni selon les saisons, ni selon les endroits. Les sex-ratio était égal parmi les sub-adultes, mais il déviait en faveur des mâles et des femelles chez les petits et les adultes, respectivement. Ceci implique une mortalité de plus en plus différentielle des mâles à l'âge sub-adulte. L'âge-ratio variait avec les saisons en raison d'un pic de natalité de mars à juin et d'une arrivée de sub-adultes dans la réserve en juillet-août, coïncidant avec l'augmentation des proies migratrices. Le pic des naissances était apparemment précédé par un autre pic des activités d'accouplement, entre novembre et mai. De nouvelles recherches devraient étudier les raisons précises du sex-ratio biaisé chez les lionceaux, de la faible densité des lions dans le Mara Triangle et du taux de sub-adultes plus élevéà Musiara que dans le Mara Triangle ou à Sekenani. [source] | |||||||||||||