Identification of ataxia‐associated mtDNA mutations (m.4052T>C and m.9035T>C) and evaluation of their pathogenicity in transmitochondrial cybrids

The potential pathogenicity of two homoplasmic mtDNA point mutations, 9035T>C and 4452T>C, found in a family afflicted with maternally transmitted cognitive developmental delay, learning disability, and progressive ataxia was evaluated using transmitochondrial cybrids. We confirmed that the 4452T>C transition in tRNA^Met represented a polymorphism; however, 9035T>C conversion in the ATP6 gene was responsible for a defective F₀‐ATPase. Accordingly, mutant cybrids had a reduced oligomycin‐sensitive ATP hydrolyzing activity. They had less than half of the steady‐state content of ATP and nearly an 8‐fold higher basal level of reactive oxygen species (ROS). Mutant cybrids were unable to cope with additional insults, i.e., glucose deprivation or tertiary‐butyl hydroperoxide, and they succumbed to either apoptotic or necrotic cell death. Both of these outcomes were prevented by the antioxidants CoQ₁₀ and vitamin E, suggesting that the abnormally high levels of ROS were the triggers of cell death. In conclusion, the principal metabolic defects, i.e., energy deficiency and ROS burden, resulted from the 9035T>C mutation and could be responsible for the development of clinical symptoms in this family. Furthermore, antioxidant therapy might prove helpful in the management of this disease. Muscle Nerve, 2009     

Initial experiences of implementation of functional integration (FI) in LEPRA India projects in Orissa

In 2000, the Government of the State of Orissa (population 37 million) in India decided to introduce functional integration for the control of leprosy, in place of the long-established vertical programme, using the general health services and the primary health care system. This paper describes the initial (9 months) experience of implementing this strategy in two projects run by LEPRA India. One of these, in the district of Koraput, was established in 1991 and covers a population of 1.5 million people. The other, in Kalahandi district, started in 1997 and covers a population of 600,000. Both projects operate under difficult conditions with regard to terrain, the use of numerous tribal languages, illiteracy, water shortage, poor roads and communications. The preparatory phase included intensive health education of the public on leprosy, using a wide range of educational media and techniques. At the same time, LEPRA India supported the Government in the training and orientation of trainers, medical officers, primary health care staff and female health workers at village level. In all, over 2000 were trained. This paper describes all aspects of the implementation of functional integration in these two areas. In the 9-month period, 4207 suspect cases were referred to medical officers by health workers, but only 256 (6%) were confirmed as having leprosy. There were 169 confirmed self-reporting cases. Despite the clearly understood intention to involve primary health staff in case detection, 67% of all cases were in fact detected by LEPRA India, possibly due to overlapping attendance at clinics by vertical and general staff. There is obviously a need for further training of the general staff since only 6% of cases referred by them were confirmed as having leprosy. Steps must also be taken to ensure that the emphasis on case detection, confirmation and treatment shifts from the vertical to the general health staff. The supply of anti-leprosy drugs and steroids to primary health centers needs improvement. Appropriate teaching and learning material is urgently needed for both field staff and medical officers.     

Harvey Cushing's postoperative sketches of pediatric brain tumors

Harvey Cushing was a man of many talents. Not only was he a premier surgeon and scientist, but a prolific author and artist as well. In this paper, we present two postoperative sketches of pediatric brain tumors drawn by Dr. Cushing. These sketches are representative of drawings which accompany many of his operative notes at the Peter Bent Brigham Hospital. About 25% of Cushing's surgical sketches depict operations performed on children. The most commonly drawn childhood tumors were craniopharyngiomas and gliomas of the brain stem and cerebellum. These drawings reveal how Cushing maintained detailed records of his surgical experience. It is clearly evident from these records that Dr. Cushing gained substantial experience in the treatment of pediatric brain tumors.     

IGF-I enhances cortisol secretion from guinea-pig adrenal gland: in vivo and in vitro study

Insulin-like growth factor (IGF)-I is a ubiquitously synthesized peptide that, along with IGF-II, acts via the IGF-R type I receptor. IGF-I and its receptor are expressed in the adrenal gland of humans and bovines, the secretion of which they seem to stimulate. As in humans and cows, the main glucocorticoid hormone secreted by guinea-pig adrenals is cortisol, and hence we have studied the adrenocortical effects of IGF-I in this species. In vivo experiments showed that prolonged IGF-I administration raised the plasma concentration of cortisol in both normal and dexamethasone/captopril-treated guinea pigs, thereby ruling out the possibility that IGF-I may act by activating the hypothalamic-pituitary-adrenal axis and the renin-angiotensin system. In vitro experiments demonstrated that IGF-I enhanced basal, but not maximally agonist [ACTH and angiotensin-II (Ang-II)]-stimulated, cortisol secretion from freshly dispersed guinea-pig inner adrenocortical cells. The IGF-I immuno-neutralization suppressed the IGF-I secretagogue effect, without altering the cortisol response to both ACTH and Ang-II. IGF-I raised cyclic-AMP and inositol triphosphate release from dispersed guinea-pig cells, and the effect was reversed by the adenylate cyclase inhibitor SQ-22536 and the phospholipase-C (PLC) inhibitor U-73122. SQ-22536, U-73122, the protein kinase (PK) A inhibitor H-89 and the PKC inhibitor calphostin-C decreased by approximately 50% the cortisol response of dispersed cells to IGF-I, and the combined exposure to SQ-22536 and U-73122 abolished it. We conclude that IGF-I stimulates glucocorticoid secretion from guinea-pig adrenocortical cells, acting via selective receptors coupled to both the adenylate cyclase/PKA- and PLC/PKC-dependent signaling cascades.     

Rational Design,Synthesis, and SAR of a Novel Thiazolopyrimidinone Series of Selective PI3K-beta Inhibitors

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Effects of a community-based healthy heart program on increasing healthy women's physical activity: a randomized controlled trial guided by Community-based Participatory Research (CBPR)

Background  

Cardiovascular disease remains the leading killer of women in most developed areas of the world. Rates of physical inactivity and poor nutrition, which are two of the most important modifiable risk factors for cardiovascular disease in women, are substantial. This study sought to examine the effectiveness of a community-based lifestyle-modification program on increasing women's physical activity in a randomized trial guided by community-based participatory research (CBPR) methods.     

A comparative study of the biochemical properties of human and mouse recombinant O6-methylguanine-DNA methyltransferases

The O⁶-methylguanine-DNA methyltransferase (MGMT) repairs mutagenicand carcinogenic O⁶-alkylguanine in DNA by accepting stoichiometricallythe alkyl group from the base. Although the mouse MGMT is largerthan the human protein because of an additional tetrapeptidesequence, these proteins are 70% homologous. Recombinant MGMTsof the human, the mouse and a mouse mutant with the tetrapeptidedeleted were purified to homogeneity from Escherichia coli.The N-terminal amino acid sequences of these proteins are identicalto those predicted from the nucleotide sequences, and theirmolecular masses deter mined by SDS-PAGE agreed with the predictedvalues. However, the observed isoelectric points of 9.3, 9.2and 9.3, for the human, mouse and mutant mouse proteins respectivelywere significantly different from the values, 8.09, 7.47 and7.49 calculated from the amino acid composition. The extinctioncoefficients E_1%^{280 nm} of human, mouse and mutant mouse proteinwere calculated from amino acid composition to be 18.2, 11.1and 11.3 respectively. These values agree fairly well with calculatedvalues. Human and wild-type mouse MGMTs react with the alkylatedbase in a synthetic DNA substrate poly(dC, dG, m⁶dG) with comparablesecond-order rate constants of 2.2x10⁸ and 3.7x10⁸ 1/M/min at37°C respectively and were inactivated by O⁶-benzylguanineat similar rates. The initial reaction rate (K_in) and rate ofinactivation (k_inact) constants for reaction with the base werecalculated to be 1.8x10^–4 M and 1.4x10^–3/s for thehuman protein, 2.3x10^–4 M and 1.1x10^–3/s for thewild-type mouse protein, and 2.1x10^–4 and 1.4x10^–3/sfor the mutant mouse protein respectively. The MGMTs were inactivatedto the extent of 55—65% after heating at 50°C in 20mMTris-HCI, pH 8.0, 1 mM EDTA, 1 mM DTT and 10% glycerol. However,in the presence of DNA (200 µg/ml), only 25—35%of the protein was inactivated. Both DNA and RNA inhibited allthree enzymes in a concentration-dependent fashion, althoughDNA was a better inhibitor than RNA. High salt (0.2 M NaCl)inhibited human MGMT by 80%, while the wild-type and the mutantmouse MGMTs were inhibited by 55%. The human protein had higheraffinity for binding to duplex DNAs than the mouse proteins.