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In this contribution we suggest a heuristic molecular lipophilicity potential (HMLP), which is a structure-based technique requiring no empirical indices of atomic lipophilicity. The input data used in this approach are molecular geometries and molecular surfaces. The HMLP is a modified electrostatic potential, combined with the averaged influences from the molecular environment. Quantum mechanics is used to calculate the electron density function rho(r) and the electrostatic potential V(r), and from this information a lipophilicity potential L(r) is generated. The HMLP is a unified lipophilicity and hydrophilicity potential. The interactions of dipole and multipole moments, hydrogen bonds, and charged atoms in a molecule are included in the hydrophilic interactions in this model. The HMLP is used to study hydrogen bonds and water-octanol partition coefficients in several examples. The calculated results show that the HMLP gives qualitatively and quantitatively correct, as well as chemically reasonable, results in cases where comparisons are available. These comparisons indicate that the HMLP has advantages over the empirical lipophilicity potential in many aspects. The HMLP is a three-dimensional and easily visualizable representation of molecular lipophilicity, suggested as a potential tool in computer-aided three-dimensional drug design. 相似文献
23.
The present study assesses the endocrinological, endometrial histology and vaginal ultrasound profiles of nomegestrol acetate subdermal implant users at varying times after insertion. Follicle stimulatory hormone, luteinizing hormone, oestradiol, progesterone, vaginal ultrasound assessment of the ovaries and the histological dating of the endometrium were serially assessed for a period of 50 days immediately after the insertion, and after at 6 months and 12 months of use. The endocrinological results of this prospective observational clinical trial indicated that 75% of the cycles across the study period in Uniplant users were anovulatory, 63% showing development of a persistent non-luteinized follicle. Anovulatory cycles devoid of follicular development were seen primarily in the first months after Uniplant insertion. Ovulatory cycles represented 25% of the Uniplant cycles. Inadequate luteal phase or disregulation of follicular growth was a common feature of ovulatory cycles. In conclusion, these findings suggest that the contraceptive mechanisms of a single nomegestrol acetate subdermal implant involve prevention of follicular growth, development of a persistent non-luteinized follicle, inadequate luteal phase and disruption of the endometrial architecture. 相似文献
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M Pomerantz JR Denton GA Huitt JM Brown LA Powell MD Iseman 《Canadian Metallurgical Quarterly》1996,62(4):990-993
BACKGROUND: In a series of 229 patients infected with mycobacterial organisms, we noted a specific female phenotype that involves isolated infections of the middle lobe and lingula. METHODS: Thirteen patients were found to have infections of the middle lobe, lingula, or both. All of them were infected with Mycobacterium other then Mycobacterium tuberculosis, all were women, 12 of the 13 were slender, and most had variable combinations of skeletal abnormalities. All underwent resection of the middle lobe, lingula, or both. RESULTS: There were no operative deaths. Only 2 patients have had reactivation requiring additional antibiotic therapy. All patients have had a decreased number of pulmonary infections in the postoperative period. Anatomic findings at operation included a complete major fissure and at least a partially complete minor fissure with middle lobe resections or an elongated lingula. CONCLUSIONS: Mycobacterial infection of the middle lobe and lingula is primarily a disease of asthenic women and is often associated with skeletal abnormalities and complete fissures or an elongated lingula. We recommend that surgical intervention be performed early once the condition is identified. 相似文献
26.
We tested the hypothesis that adaptations in peripheral arterial vasoreactivity are induced by exercise training. Male rats were trained to run on a treadmill at 30 m/min (15 degrees incline) for 1 h/day 5 days/wk for 10-12 wk. Efficacy was indicated by a 51% increase (P < 0.05) in citrate synthase activity in soleus muscle of exercise-trained (ET) rats compared with that of sedentary (SED) control rats. Responses to vasoactive compounds were examined in vitro using rings of abdominal aorta. Maximal isometric contractile tension evoked by KCl, norepinephrine (NE), and phenylephrine were not different between groups; sensitivity to phenylephrine was also not different between groups. However, sensitivity was lower for both KCl and NE in vessels from ET animals. Endothelium removal did not influence KCl sensitivity but did abolish the difference in NE sensitivity of vessel segments between ET and SED animals. Maximal vasodilator responses induced by acetylcholine (ACh; NE or prostaglandin F2 alpha preconstriction) were greater in vessel rings from ET rats. However, dilatory responses by sodium nitroprusside (NE or prostaglandin F2 alpha preconstriction) and forskolin (NE preconstriction) were not different between groups, indicating that the augmented ACh-induced dilatory response resulted from an adaptation of the endothelium. Blockade of nitric oxide synthase activity diminished ACh-induced vasodilation by 79 and 100% in SED and ET rats, respectively. These results indicate that training alters vasomotor function in rat abdominal aortas through adaptations of both endothelium and smooth muscle. 相似文献
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Q Hu M Trevisan Y Xu W Dong SA Berger SD Lyman MD Minden 《Canadian Metallurgical Quarterly》1995,95(6):2530-2538
The growth of human leukemic cells in culture and in vivo is dependent upon the presence of hematopoietic growth factors. Most populations of human leukemic acute myeloblastic leukemia (AML) cells express c-Kit on their surface and respond to Kit ligand (KL) in culture. To determine if this interaction was of potential significance in vivo we used a mouse model system. 32D cells, a murine IL-3-dependent myeloid cell line, were rendered KL responsive by transfection of the murine c-Kit. After injection of 32D or 32D-Kit cells into syngeneic hosts, animals bearing 32D-Kit cells, but not 32D cells, became moribund and were killed. These animals had circulating leukemic blast cells, infiltration of bone marrow, spleen, brain, liver, lung, and kidney. Cells recovered from some of the animals continued to be dependent upon IL-3 or KL for growth while in other cases the cells were factor independent. This model illustrates that the constitutive expression of c-Kit enhances the leukemic potential of 32D cells. The model will be useful for studying the progression of leukemia in vivo and testing whether interruption of the interaction of Kit and KL can affect the growth of leukemic cells. 相似文献
29.
MD Margolin AG Cogan M Taylor D Buck TN McAllister C Toth BS McAllister 《Canadian Metallurgical Quarterly》1998,69(8):911-919
The posterior maxilla has traditionally been one of the most difficult areas to successfully place dental implants due to poor bone quality and close approximation to the maxillary sinus. Sinus augmentation procedures have become a viable means of assuring adequate bone for the placement of dental implants in this area. However, with the techniques currently employed, a considerable variation in the quality of bone attained with the sinus augmentation procedure exists. The purpose of this in vivo study was to evaluate the healing response and bone formation stimulated by 3 doses of recombinant human osteogenic protein-1 (rhOP-1), 0.25, 0.6, and 2.5 mg OP-1 per gram of collagen matrix; natural bone mineral; or collagen matrix alone (control) placed in the maxillary sinus of adult chimpanzees. Results were assessed using clinical, histologic, and radiographic techniques. Radiographic analysis of the computed tomography scans taken at 1 week, and 2.5, 4.5, and 6.5 months revealed a more rapid mineralization with the 2.5 mg OP-1/g collagen matrix and natural bone mineral treatment groups. The incremental bone mineral density (BMD) increase for these 2 treatments from 1 week to 2.5 months was over 2.5 times the increase found with the collagen matrix alone; these 2 treatments also had a higher BMD at the most superior slices evaluated when compared to the other 3 groups. Biopsy specimens were taken at 3.5, 5.5, and 7.5 months and for all 5 treatment groups bone formation was observed at all time points in the majority of the specimens. At 7.5 months the 2.5 and 0.6 mg OP-1/g collagen matrix treatment groups had an increase in the percent bone area when compared to the matrix alone control. In conclusion, these results demonstrate that sinus augmentation with natural bone mineral or 2.5 mg OP-1/g collagen matrix induce comparable radiographic and histologic evidence of bone formation and that both of these treatments performed superior to the control group of collagen matrix alone based upon all methods of evaluation. 相似文献
30.
MD Cohen ST Auringer JL Grosfeld CA Galliani NA Heerema 《Canadian Metallurgical Quarterly》1993,23(6):463-466
The purpose of this study is to present three patients with multifocal primary neuroblastoma, to review the literature, and describe the radiographic findings. SUBJECTS AND METHODS: Three children with multifocal neuroblastoma have been identified. The case histories and imaging findings in these patients are reviewed. RESULTS: Two children had synchronous and one child had metachronous multifocal primary neuroblastoma. The primary tumors were both in the abdomen in one patient, both in the chest in another patient, and in the chest and abdomen in the third patient. Evidence for multifocal origin of these tumors, rather than metastatic spread, is presented. CONCLUSION: Multifocal primary neuroblastomas can occur. The tumors maybe synchronous or metachronous. Awareness of this disorder may prevent errors in diagnosis and staging. Although not identified in our patients there is a strong familial incidence of neuroblastomas in those patients with multifocal tumors. 相似文献