N Engl J Med. 2003 Feb 20;348(8):711-9. Detection of pathologic prion protein in the olfactory epithelium in sporadic Creutzfeldt-Jakob disease.
Zanusso G, Ferrari S, Cardone F, Zampieri P, Gelati M, Fiorini M, Farinazzo A, Gardiman M, Cavallaro T, Bentivoglio M, Righetti PG, Pocchiari M, Rizzuto N, Monaco S.
Department of Neurologic and Visual Sciences, University of Verona, Verona, Italy.
BACKGROUND: Olfactory cortexes and the olfactory tracts are involved in sporadic Creutzfeldt-Jakob disease. We examined peripheral regions of the olfactory sensory pathway, including the olfactory mucosa, to assess whether pathologic infectious prion protein (PrPSc) is deposited in the epithelium lining the nasal cavity. METHODS: We studied nine patients with neuropathologically confirmed sporadic Creutzfeldt-Jakob disease. We obtained the brain, the cribriform plate with the attached olfactory mucosa, and the surrounding respiratory epithelium at autopsy. Control samples of nasal mucosa were obtained post mortem or at biopsy from age-matched control subjects and from control patients with other neurodegenerative diseases. The olfactory and respiratory mucosa and the intracranial olfactory system were analyzed by light microscopy, immunohistochemistry, and Western blotting for pathological changes and for deposition of PrPSc. RESULTS: In all nine patients with sporadic Creutzfeldt-Jakob disease, PrPSc was found in the olfactory cilia and central olfactory pathway but not in the respiratory mucosa. No PrPSc was detected in any of the tissue samples from the 11 controls. CONCLUSIONS: Our pathological and biochemical studies show that PrPSc is deposited in the neuroepithelium of the olfactory mucosa in patients with sporadic Creutzfeldt-Jakob disease, indicating that olfactory biopsy may provide diagnostic information in living patients. The olfactory pathway may represent a route of infection and a means of spreading prions. 2003 Massachusetts Medical Society
PMID:_12594315
J Biol Chem. 2001 Apr 27;276(17):14324-8. Epub 2001 Jan 04. Reconstitution of prion infectivity from solubilized protease-resistant PrP and nonprotein components of prion rods.
Shaked GM, Meiner Z, Avraham I, Taraboulos A, Gabizon R.
Department of Neurology, The Agnes Ginges Center for Human Neurogenetics, Hadassah University Hospital, Jerusalem 91120, Israel.
The scrapie isoform of the prion protein, PrP(Sc), is the only identified component of the infectious prion, an agent causing neurodegenerative diseases such as Creutzfeldt-Jakob disease and bovine spongiform encephalopathy. Following proteolysis, PrP(Sc) is trimmed to a fragment designated PrP 27-30. Both PrP(Sc) and PrP 27-30 molecules tend to aggregate and precipitate as amyloid rods when membranes from prion-infected brain are extracted with detergents. Although prion rods were also shown to contain lipids and sugar polymers, no physiological role has yet been attributed to these molecules. In this work, we show that prion infectivity can be reconstituted by combining Me(2)SO-solubilized PrP 27-30, which at best contained low prion infectivity, with nonprotein components of prion rods (heavy fraction after deproteination, originating from a scrapie-infected hamster brain), which did not present any infectivity. Whereas heparanase digestion of the heavy fraction after deproteination (originating from a scrapie-infected hamster brain), before its combination with solubilized PrP 27-30, considerably reduced the reconstitution of infectivity, preliminary results suggest that infectivity can be greatly increased by combining nonaggregated protease-resistant PrP with heparan sulfate, a known component of amyloid plaques in the brain. We submit that whereas PrP 27-30 is probably the obligatory template for the conversion of PrP(C) to PrP(Sc), sulfated sugar polymers may play an important role in the pathogenesis of prion diseases.
PMID:_11152454
J Virol. 2001 Feb;75(3):1408-13. Identification of two prion protein regions that modify scrapie incubation time.
Supattapone S, Muramoto T, Legname G, Mehlhorn I, Cohen FE, DeArmond SJ, Prusiner SB, Scott MR.
Institute for Neurodegenerative Diseases, University of California, San Francisco, California 94143, USA.
A series of prion transmission experiments was performed in transgenic (Tg) mice expressing either wild-type, chimeric, or truncated prion protein (PrP) molecules. Following inoculation with Rocky Mountain Laboratory (RML) murine prions, scrapie incubation times for Tg(MoPrP)4053, Tg(MHM2)294/Prnp(0/0), and Tg(MoPrP, Delta23-88)9949/Prnp(0/0) mice were approximately 50, 120, and 160 days, respectively. Similar scrapie incubation times were obtained after inoculation of these lines of Tg mice with either MHM2(MHM2(RML)) or MoPrP(Delta23-88)(RML) prions, excluding the possibility that sequence-dependent transmission barriers could account for the observed differences. Tg(MHM2)294/Prnp(0/0) mice displayed prolonged scrapie incubation times with four different strains of murine prions. These data provide evidence that the N terminus of MoPrP and the chimeric region of MHM2 PrP (residues 108 through 111) both influence the inherent efficiency of prion propagation.
PMID:_11152514
Hum Mol Genet. 2001 Jan 15;10(2):107-16. Expression of expanded repeat androgen receptor produces neurologic disease in transgenic mice.
Abel A, Walcott J, Woods J, Duda J, Merry DE.
Neurogenetics Branch, National Institutes of Neurological Disease and Stroke, National Institutes of Health, Bethesda, MD, USA.
Spinal and bulbar muscular atrophy (SBMA) is a motor neuron disease caused by the expansion of a polyglutamine tract within the androgen receptor. This disease is unusual among the polyglutamine diseases in that it involves lower motor and sensory neurons, with relative sparing of other brain structures. We describe the development of transgenic mice, created with a truncated, highly expanded androgen receptor driven by the neurofilament light chain promoter, which develop many of the motor symptoms of SBMA. In addition, transgenic mice created with the prion protein promoter develop widespread neurologic disease, reminiscent of juvenile forms of other polyglutamine diseases. Thus, in these experiments, the distribution of neurologic symptoms depends on the expression level and pattern of the promoter used, rather than on specific characteristics of androgen receptor metabolism or function. The transgenic mice described here develop neuronal intranuclear inclusions (NIIs), a hallmark of SBMA and the other polyglutamine diseases. We have shown these inclusions to be ubiquitinated and to sequester molecular chaperones, components of the 26S proteasome and the transcriptional activator CREB-binding protein. Apart from the presence of NIIs, evidence of neuropathology or neurogenic muscle atrophy was absent, suggesting that the neurologic phenotypes observed in these mice were the result of neuronal dysfunction rather than neuronal degeneration. These mice will provide a useful resource for characterizing specific aspects of motor neuron dysfunction, and for testing therapeutic strategies for this and other polyglutamine diseases.
Hair loss is a problem in modern soceity. Examining the factors of hair growth may
shed light on how hair loss might occur.
How long can hair grow before it stops growing eventually, if it does?
Given that the hair growth rate is quite uniform and constant, somewhere between 0.3-0.5 millimeters per day, it's believed that the length of anagen, the growth phase, differs among individuals, and this is the major determinant to the maximum hair length. For some individuals, anagen may last ten years.
Of course, the length of the anagen is governed by genes, and the genetic background of the individuals. Non-genetic factors such as nutritional condition, weather, seasonal changes (hair may grow a bit faster during winter), taking medications, health condition may of course influence the rate of
hair growth as well as hair loss.
The shape of the hair, straight or curly, is dependent on the shape of the follicle. A circular or round hair follicle would generate straight hair, while the follicle with oval or elliptical shapes (in its cross-section) would produce a curly hair.
Hair Million works for women as well as men.