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81.
82.
The nucleotide sequence of the cDNA encoding a sperm protein (rSMP-B) was determined in a previous study. Two peptide segments corresponding to the extracellular domain of the deduced sperm polypeptide were synthesized as multiple antigen peptide (MAP) and designated as rSMP-229 and rSMP-230. Polyclonal antibodies were raised against the two MAPs. Sera obtained from rabbits immunized with rSMP-230 interacted with human and rabbit sperm membrane proteins with estimated molecular sizes of 72 and 20.1 kD, respectively. Adult female and male rats were immunized with the MAPs and their fertilities determined. Immunization of female rats with rSMP-229 and rSMP-230 induced infertility in 25% and 83% of the treated animals, respectively. All male rats immunized with rSMP-229 remained fertile; whereas animals immunized with rSMP-230 did not mate with normal cycling female rats. Three impotent male rats were found to regain their mating potency 45 days after the last booster injection. These findings demonstrated that immunization with rSMP-230 induced a reversible impotency in male rats. Serum testosterone and LH levels were reduced in rSMP-230-immunized male rats and were elevated in rSMP-229-immunized animals. Histopathological examination of sections of testes from male rats immunized with rSMP-230 showed impairment of spermatogenesis and sloughing of germ cells into the lumen of the seminiferous tubules. The testes of male rats immunized with rSMP-229 showed normal morphology and active spermatogenesis with scattered foci of nodular hyperplasia of Leydig cells in the interstitial areas. In conclusion, immunization with synthetic peptide segments corresponding to different domains of a deduced sperm protein induced infertility in a significant number of female rats and transient impotency in male rats.  相似文献   
83.
We have conducted a retrospective review of 134 cases of neurogenic tumors of the thorax, including 66 in infants and children and 68 in adults. Nerve cell tumors were the majority in infants and children (84.8%) and were mostly malignant (67.2%). Nerve sheath tumors were more frequent in adults (73.5%). Nerve cell tumors were the most frequent tumors in males and nerve sheath tumors in females. Nineteen tumors were associated with von Recklinghausen's disease. The tumors were symptomatic in 76.4% of children and 36.7% of adults. Spinal cord compression was observed in 8 infants and children and in 2 adults. Neo-adjuvant treatment was administrated to 3 patients. Resection was complete for 80 benign tumors out of 86 (93%) and for 26 malignant tumors out of 48 (54%). Postoperative chemo- or radiotherapy (or both) was administrated to 17 children and 8 adults. The mean followup periods were 11 years for the infants and children and 8 years, 6 months for the adults. There was one postoperative death. There were no late deaths related to benign tumor. The prognosis of spinal cord compression depended on the malignancy and staging of the tumors. At 5 years postoperatively, 21 children out of 28 with neuroblastomas and 8 out of 9 with ganglioneuroblastomas were alive. The possibility of maturation of neuroblastomas and survival with hepatic metastases was confirmed. The prognosis in cases of chemodectoma depended on the extension. Patients with malignant schwannomas had very poor prognoses, especially when associated with von Recklinghausen's disease.  相似文献   
84.
One of the key limiting factors in the treatment of advanced stage human epithelial malignancies is the lack of new, selective molecular targets for antineoplastic therapy. A substantial subset of human breast, ovarian, endometrial, colorectal, and prostatic cancers express elevated levels of fatty acid synthase, the major enzyme required for endogenous fatty acid biosynthesis, and carcinoma lines are growth inhibited by cerulenin, a noncompetitive inhibitor of fatty acid synthase. We have shown previously that the difference in fatty acid biosynthesis between cancer and normal cells is an exploitable target for metabolic inhibitors in the in vitro setting and in vivo in a human ovarian carcinoma xenograft in nude mice. Here, we report that cerulenin treatment of human breast cancer cells inhibits fatty acid synthesis within 6 h after exposure, that loss of clonogenic capacity occurs within the same interval, and that DNA fragmentation and morphological changes characteristic of apoptosis ensue.  相似文献   
85.
86.
BACKGROUND: Cardiomyoplasty (CMP) uses the latissimus dorsi muscle (LDM) to assist the heart in cases of cardiac failure. Distal ischemia and necrosis of the LDM is a recognized complication of CMP that can reduce distal muscle function and the mechanical effectiveness of CMP. METHODS: Canine (n = 9) LDMs were subjected to a 10-day period of vascular delay followed by a simulated CMP. Two weeks after simulated CMP (corresponding to the healing delay between CMP and the onset of LDM stimulation used in the clinical setting), LDM perfusion was measured in the distal, middle, and proximal segments of the muscle, and circumferential (distal and middle squeezing muscle function) and longitudinal (proximal pulling muscle function) force generation and fatigue rates were measured. The results were compared with the contralateral nondelayed simulated CMP. RESULTS: Muscle perfusion was significantly (p < 0.05) greater in the distal and middle segments of vascular-delayed LDMs. Circumferential muscle force generation and fatigue rates were significantly (p < 0.05) improved in the vascular-delayed LDMs. CONCLUSIONS: Vascular delay can significantly improve LDM perfusion and function in a model that closely reflects clinical CMP, and the use of vascular delay may improve clinical outcomes in CMP.  相似文献   
87.
Vertigo     
Vertigo, with or without nystagmus, may accompany many diseases. Most causes are transient and benign. A systematic approach saves valuable time. Nonrotational dizziness must be distinguished from true vertigo in which a sensation of motion is involved. Careful evaluation of nystagmus is essential, as is a complete cardiovascular examination. Meniere's syndrome, while common, is overdiagnosed.  相似文献   
88.
We present an extremely rapid and efficient method for the separation of salt-dissociated histones from DNA in which the macromolecular components of chicken erythrocyte chromatin are partitioned in a two-phase system of the water-soluble, nonionic polymers, poly(ethylene glycol) and dextran. We have compared the association products and conformations of salt-dissociated histones purified with the two-phase procedure and histones that had been extracted with 0.4 M H2SO4. In the gel chromatography system of D. R. vander Westhuyzen and C. von Holt (1971), FEBS Lett. 14, 333-337] the association products of salt-dissociated and acid-extracted histones are indistinguishable. Furthermore, the circular dichroism spectra of histones prepared with the two methods are identical within experimental error. These results indicate that histones extracted, with sulfuric acid can adopt conformations at least very similar to those of salt-dissociated preperties of total erythrocyte histones are the same in 2 M NaCl as those of these histones bound to DNA in chromatin in 1 mM Tris-Cl (pH 7.5). This result and the studies of Weintraub et al. [Weintraub, H., Palter, K., and Van Lente, F. (1975), Cell 6, 68-110] on the patterns of tryptic digest products of histones strongly suggest that in 2 M NaCl the histones exist in conformations very similar to their conformations when bound to DNA. The concept of native histone conformations is discussed in light of our results.  相似文献   
89.
Radiographic findings associated with small talar dome fractures were analyzed in 21 patients. Representative cases are presented. The classification of talar dome fractures, and the role of the radiologist in their evaluation, are discussed.  相似文献   
90.
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