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181.
The isthmo-optic nuclei (ION) and ectopic neurons, which constitute the centrifugal visual system (CVS), are thought to be cholinoceptive and nitrergic. However, it is not clear which neurons express these markers, namely the ones that project to the retina rather than in neurons that only participate in a local circuit. Therefore, to characterize the neurochemical patterns of the centrifugal visual system in the post-hatched chick, retinopetal cells of the isthmo-optic nuclei and the ectopic region were identified via immunolabeling for cholera toxin, a neuronal tracer, which has been injected in the ocular globe. Then, double labeled with acetylcholinesterase histochemistry to reveal cholinergic synapses, or NADPH-diaphorase histochemistry as a nitrergic marker. Briefly, acetylcholinesterase activity was present mainly in cholera toxin labeled cell bodies of the isthmo-optic nucleus and the ectopic region indicating that retinal projecting neurons of centrifugal visual system comprise a cholinoceptive pathway. On the other hand, NADPH-diaphorase histochemistry was present in the neuropile and sparse cell bodies inside of the isthmo-optic nucleus and in ectopic neurons which were not cholera toxin positive suggesting their role in an intrinsic circuit of the centrifugal visual system. These data support the idea that these two neurochemical systems are present in distinct neuronal populations in the centrifugal visual system.  相似文献   
182.
Precursor lesions of ovarian epithelial malignancy   总被引:10,自引:0,他引:10  
Most ovarian carcinomas arise from the mesothelial surface lining of the ovaries, or from invaginations of this lining into the superficial ovarian cortex to form cortical inclusion cysts. The native ovarian surface mesothelium is of an 'uncommitted' phenotype, and has potential to modulate to epithelial or mesenchymal phenotypes in response to signals such as those associated with ovulation. The exposure of the mesothelial lining of an inclusion cyst to the ovarian stromal microenvironment may be responsible for the phenotypic change to Müllerian epithelium so commonly seen in these cysts. Müllerian metaplasia is usually to a serous phenotype, and it is possible that undefined molecular events occurring in an inclusion cyst that has undergone Müllerian metaplasia may initiate neoplastic change in these cysts. This may be the developmental pathway of most invasive serous carcinomas. Occasional rare cases of ovarian intraepithelial neoplasia, manifested by epithelial atypia in an inclusion cyst or on the surface epithelium without invasive carcinoma, are identified histologically. Serous borderline tumours represent a separate category and in most cases probably do not progress to frank carcinoma. Mucinous carcinomas may in some cases have arisen from pre-existing benign and borderline mucinous tumours. Endometriosis of the ovary is associated with genetic abnormalities and is frequently found in association with clear cell and endometrioid carcinomas, suggesting that in many cases these latter two types of carcinoma may have arisen directly from endometriotic deposits. Ovaries removed prophylactically from women with a family history of ovarian carcinoma or with a mutation in one of the genes predisposing to ovarian carcinoma should be processed in their entirety, and examined closely not just for obviously neoplastic lesions, but also for more subtle morphological abnormalities of the surface epithelium or the epithelium lining cortical inclusion cysts.  相似文献   
183.
Sixty-three patients who underwent renal revascularization at the time of aortic surgery were retrospectively reviewed. These patients had significant renal artery stenosis in addition to either severe aortoiliac occlusive disease or aortic aneurysmal disease. Fifty-eight patients were hypertensive, whereas five patients were normotensive and these renal lesions were treated prophylactically. The operative mortality rate was 3%. Despite lack of selectivity in these patients with diffuse atherosclerosis, 60% (35 of 58) of the patients with hypertension could be classified as either "cured" or "improved." Patients with bilateral renal artery involvement and moderate azotemia were noted to improve with respect to renal function postoperatively. No patient has required chronic dialysis at a mean follow-up period of 22.6 months. Simultaneous aortic and renal artery surgery may be performed with low morbidity and mortality rates and produce a gratifying improvement in hypertension. Renal functional improvement and perhaps preservation of renal mass may be anticipated in selected patients.  相似文献   
184.
N-(2-mercaptoethyl)-lt3-diaminopropane (WR1065) protects againstradiation-induced cell killing and mutagenesis at the hypoxanthine-guaninephosphoribosyl transferase (HGPRT) locus in V79 Chinese hamsterhing fibroblast cells. At a concentration of 4 mM, WR1065 wasfound to be effective in protecting against radiation-inducedcell lethality only if present during irradiation, e.g., a dosemodification factor (DMF) of 1.9. No protective effect was observedif the protector was added within 5 min after irradiation or3 h later, e.g., DMFs of 1.0 and 1.1, respectively. The effectof WR1065 on radiation-induced mutation, expressed as resistanceto the cytotoxic purine analogue 6-thioguanine (HGPRT), wasalso investigated. In contrast to the treatment-schedule dependencefor protection by WR1065 against cell killing, this agent waseffective in reducing radiation-induced mutations regardlessof when it was administered. Following a dose of 10 Gy of 60Co-rays, the mutation frequencies observed per 106 survivors were77 ± 8, 27 ± 6, 42 ± 7, and 42 ±7 for radiation only, and WR1065 present during, immediatelyafter, or 3 h after irradiation. These data suggest that althougha segment of radiation-induced damage leading to reproductivedeath cannot be modulated through the postirradiation actionof WR1065, processes leading to the fixation of gross geneticdamage and mutation induction in surviving cells can be effectivelyaltered and interfered with leading to a marked reduction inmutation frequency.  相似文献   
185.
dl-Ethylketazocine (EKC, 0.01 mg/kg) and saline were established as discriminative stimuli for food-maintained responding in macaque monkeys. Thirty consecutive presses on a right or left lever were reinforced with food, contingent on whether EKC or saline were administered before the session. For tests of antagonism, naltrexone, or UM 979 [(l)-5,9-alpha-dimethyl-2-(3-furylmethyl)-2-hydroxy-6,7-benzomorphan] was administered concomitantly with EKC,dl-cyclazocine, or nalorphine. Both antagonists blocked completely the EKC discriminative stimulus. The antagonism of the stimulus and rate-altering effects of EKC was surmountable, with considerable intersubject variability in the magnitude of the EKC dose increase required to overcome the blockade. Cyclazocine and nalophine, mixed agonist-antagonist opioids that share stimulus properties with EKC, were also susceptible to antagonism. Naltrexone antagonized completely the EKC stimulus effects of nalorphine; naltrexone and UM 979 antagonized completely the EKC stimulus effects of cyclazocine. Naltrexone antagonism of the cyclazocine stimulus was not surmountable, due to a lack of antagonism of the rate-decreasing effects of high cyclazocine doses.  相似文献   
186.
Maternal and Child Health Journal - The Maternal and Child Health (MCH) Pipeline Training Program, promotes development of a diverse health workforce by training undergraduate students from...  相似文献   
187.
Prevention Science - Screening is an essential prevention practice for a number of health conditions. However, screening coverage remains generally low. Studies that investigate determinants of...  相似文献   
188.
Maternal and Child Health Journal - Low birthweight (LBW) is a significant public health problem in sub-Saharan Africa and LBW in rural Zambia is high. Our study explored the prevalence of LBW for...  相似文献   
189.
Prevention Science - The NAMWEZA intervention was implemented, using a ten-session group format, to build skills targeting psychosocial vulnerabilities and enhancing HIV prevention among people...  相似文献   
190.
Fluorescence-advanced videodermatoscopy is not a widespread diagnostic technique. Its application in dermatology can facilitate the diagnosis of diseases such as cutaneous larva migrans by enabling us to recognize the precise position of larva in vivo on the skin. Using this noninvasive technique, we detected a case of cutaneous larva migrans in a patient.  相似文献   
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