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51.
Michael D Seidman Mumtaz J Khan Wen Xue Tang Wayne S Quirk 《Otolaryngology--head and neck surgery》2002,127(3):138-144
OBJECTIVES: Lecithin is a polyunsaturated phosphatidylcholine (PPC), which are high energy functional and structural elements of all biologic membranes. PPC play a rate-limiting role in the activation of numerous membrane-located enzymes, including superoxide dismutase and glutathione, which are important antioxidants protecting cell membranes from damage by reactive oxygen species (ROS). ROS-induced damage to mitochondrial DNA may lead to reduced mitochondrial function in the cochlea and resultant hearing loss. STUDY DESIGN AND SETTING: The effects of lecithin on aging and age-associated hearing loss were studied in rats by measuring hearing sensitivities using auditory brainstem responses (ABR). In addition, mitochondrial function as a measure of aging was assessed by determining mitochondrial membrane potentials using flow cytometry and by amplifying mitochondrial DNA deletions associated with aging. Harlan-Fischer rats aged 18 to 20 months (n = 14) were divided into 2 groups. The experimental group was supplemented orally for 6 months with lecithin, a purified extract of soybean phospholipid (Nutritional Therapeutics, Allendale, NJ). RESULTS: The data obtained were compared with the control group. ABRs were recorded at 2-month intervals and showed significant preservation of hearing sensitivities in the treated subjects. Flow cytometry revealed significantly higher mitochondrial membrane potentials in the treated subjects, suggesting preserved mitochondrial function. Finally, the common aging mitochondrial DNA deletion (mtDNA(4834)) were amplified from brain and cochlear tissue including stria vascularis and auditory nerve. This specific deletion was found significantly less frequent in all tissues in the treated group compared with the controls. CONCLUSION: These experiments support our hypothesis and provide evidence that lecithin may preserve cochlear mitochondrial function and protect hearing loss associated with aging. 相似文献
52.
Glyceraldehyde-3-phosphate dehydrogenase: Nuclear translocation participates in neuronal and nonneuronal cell death
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Akira Sawa Adil A. Khan Lynda D. Hester Solomon H. Snyder 《Proceedings of the National Academy of Sciences of the United States of America》1997,94(21):11669-11674
Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) protein levels increase in particulate fractions in association with cell death in HEK293 cells, S49 cells, primary thymocytes, PC12 cells, and primary cerebral cortical neuronal cultures. Subcellular fractionation and immunocytochemistry reveal that this increase primarily reflects nuclear translocation. Nuclear GAPDH is tightly bound, resisting extraction by DNase or salt treatment. Treating primary thymocytes, PC12 cells, and primary cortical neurons with antisense but not sense oligonucleotides to GAPDH prevents cell death. Because cell-death-associated nuclear translocation of GAPDH and antisense protection occur in multiple neuronal and nonneuronal systems, we propose that GAPDH is a general mediator of cell death and uses nuclear translocation as a signaling mechanism. 相似文献
53.
54.
Computer-derived equations for predicting survival postoperatively. Their usefulness and limitations
E B Rypins F Khan D Collins-Irby I J Sarfeh J T Ashurst E A Stemmer 《Archives of surgery (Chicago, Ill. : 1960)》1988,123(3):354-357
We used multivariate analysis to determine whether survival following perforations of the gastrointestinal tract could be accurately predicted from preoperative data. Of 12 variables tested, four were found to have predictive value. These were age, pulmonary disease, preoperative shock, and the attending surgeon. When these four variables were employed in a logistic regression equation on 42 patients, it correctly predicted which 21 patients died before leaving the hospital. To produce an equation useful for other hospitals, we recalculated it without the attending surgeon variable. Again, the equation was used to predict survival. The correlation of predicted vs observed outcome remained high, and, using a 2 x 2 chi 2 test, the correlation was significant. We then cross validated the three-variable model on data from a second hospital. The model accurately predicted the new data equally well. We believe that predictive models can identify risk factors in a variety of patient populations and can determine who is likely to benefit from specific treatment modalities. 相似文献
55.
Gall bladder hydatid cyst is a rare entity. Concurrent occurrence of gall blader hydatid cysts along with liver cysts, especially with the biliary channels clear of cysts, is very rare. We report a 27-year-old man with a gall bladder hydatid cyst that was diagnosed only after opening the resected specimen of the gall bladder. 相似文献
56.
A. Wisanto P. Braeckmans M. Camus P. Devroey I. Khan C. Staesssen J. Smitz L. Van Waesberghe A. C. Van Steirteghem 《Journal of assisted reproduction and genetics》1988,5(2):107-111
Either a percutaneous-transvesical, a transvaginal, or a perurethral-transvesical approach can be used for oocyte recovery under ultrasound guidance in an in vitro fertilization and embryo transfer program. After having experienced these three different approaches in our program, we preferentially used the perurethral-transvesical approach as our routine technique for oocyte recovery under ultrasound guidance. We feel that this method is easier to perform and also carrier less risk for contamination. From January to December 1986, 186 oocyte retrievals under ultrasound guidance were performed. In 7 cases no oocytes were found despite normal ovarian stimulation. A total of 767 oocytes was collected; the fertilization rate was 71.8%. Forty pregnancies were achieved (21.5% per attempt or 27.7% per embryo replacement). Except for transient hematuria, no complications were observed. 相似文献
57.
This is the first report of incidence of neurogenic bladder in patients with acquired immune deficiency syndrome (AIDS) and emphasizes that it is a significant cause of various voiding dysfunctions in these patients. Neurologic disease occurs in about one third of patients with AIDS. Both central and peripheral nervous systems may be involved. Urodynamic evaluation is necessary for assessment and management of neurogenic voiding disorders in this group of patients. 相似文献
58.
Jamal M. Arif Sikandar G. Khan Mohammad Aslam Nayyara Mahmood Qamar Rahman 《Basic & clinical pharmacology & toxicology》1992,71(1):37-40
Abstract: In order to determine the pulmonary toxicity of kerosene and its ignition product (soot) in asbestos exposed subjects, the activities of phase I and phase II drug metabolizing enzymes in rat lungs after single intratracheal coexposure to Indian chrysotile asbestos and kerosene or its soot and Indian chrysotile were assayed. Exposure to kerosene or its soot resulted in a significant increase in the level of microsomal cytochrome P-450 and the activity of P-450 dependent monooxygenase, benzo(a)pyrene hydroxylase, as well as in the activities of microsomal epoxide hydrase and cytosolic glutathione-S-transferase (GST). However, in chrysotile exposed animals a reverse pattern in these parameters was recorded. The co-exposure to chrysotile and kerosene or chrysotile and soot led to a significant depletion in cytochrome P-450 level and a decrease in the activities of benzo(a)pyrene hydroxylase, epoxide hydrase and GST when compared to kerosene and soot controls, respectively. These results suggest that asbestos by altering the pulmonary drug metabolizing enzyme system may increase the toxic potential of kerosene and its ignition product in the respiratory system. 相似文献
59.
We describe 100 consecutive patients with histologically proven gastric carcinoma who were admitted to various hospitals in Northern Pakistan. Twenty-six per cent of patients were under 40 years of age. In a majority of patients the tumour was of a morphological type associated with poor prognosis. In most cases the disease was already at an advanced stage at the time of diagnosis, and most patients died within one year. 相似文献
60.
A. J. Ferdous S. N. Islam M. Ahsan C. M. Hasan Z. U. Ahmed 《Phytotherapy research : PTR》1992,6(3):137-140
The antibacterial activity of the volatile oil of Nigella sativa seeds was studied against 37 isolates of Shigella dysenteriae 1, Shigella flexneri, Shigella sonnei and Shigella boydii and 10 strains of Vibrio cholerae and Escherichia coli. Most of the strains were clinically resistant to ampicillin, co-trimoxazole and tetracycline. All the strains tested showed promising sensitivity to the volatile oil. The minimum inhibitory concentration (MIC) of the volatile oil for Shigella, Vibrio and Escherichia strains tested was between 50–400 μg/mL. 相似文献