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71.
In the present study, the applicability of fine particle ethylcellulose (FPEC) to produce matrix tablets by a wet granulation technique was evaluated. The effect of various formulation and process variables, such as FPEC content, hardness of the tablet, and solubility of the drug, on the release of drug from these tablets was examined. Tablets were prepared by wet granulation of drug and FPEC in an appropriate mass ratio. Theophylline, caffeine, and dyphylline were selected as nonionizable model drugs with solubilities from 8.3 to 330 mg/mL at 25°C. Ibuprofen, phenylpropanolamine hydrochloride, and pseudoephedrine hydrochloride were selected as ionizable drugs with solubilities from 0.1 to 2000 mg/mL at 25°C. Drug release studies were conducted in 37°C water with UV detection. As the FPEC content and the hardness of the tablets increased, the release rate of the drug decreased. The drug release rate increased with an increase in the solubility of the drug. Model equations, intended to elucidate the drug release mechanism, were fitted to the release data. Parameters were generated and data presented by SAS software. The Akaike Information Criterion was also considered to ascertain the best-fit equation. Fickian diffusion and polymer relaxation were the release mechanisms for nonionizable and ionizable drugs. 相似文献
72.
S. Ali Khan S. Jayachandran P. G. Desai P. Bonheim 《International urology and nephrology》2000,32(1):1-2
Table of Contents
Contents Volume 32 No. 1 (2000) Section One: International Urology and Nephrology 相似文献73.
Neil E Martin Thomas B Brunner Krystina D Kiel Thomas F DeLaney William F Regine Mohammed Mohiuddin Ernest F Rosato Daniel G Haller James P Stevenson Debbie Smith Barnali Pramanik Joel Tepper Wesley K Tanaka Briggs Morrison Paul Deutsch Anjali K Gupta Ruth J Muschel W Gillies McKenna Eric J Bernhard Stephen M Hahn 《Clinical cancer research》2004,10(16):5447-5454
PURPOSE: Preclinical and clinical studies have demonstrated that inhibition of prenylation can radiosensitize cell lines with activation of Ras and produce clinical response in patients with cancer. The aim of this study was to determine the maximally tolerated dose of the dual farnesyltransferase and geranylgeranyltransferase I inhibitor L-778,123 in combination with radiotherapy for patients with locally advanced pancreatic cancer. EXPERIMENTAL DESIGN: L-778,123 was given by continuous intravenous infusion with concomitant radiotherapy to 59.4 Gy in standard fractions. Two L-778,123 dose levels were tested: 280 mg/m2/day over weeks 1, 2, 4, and 5 for dose level 1; and 560 mg/m2/day over weeks 1, 2, 4, 5, and 7 for dose level 2. RESULTS: There were no dose-limiting toxicities observed in the eight patients treated on dose level 1. Two of the four patients on dose level 2 experienced dose-limiting toxicities consisting of grade 3 diarrhea in one case and grade 3 gastrointestinal hemorrhage associated with grade 3 thrombocytopenia and neutropenia in the other case. Other common toxicities were mild neutropenia, dehydration, hyperglycemia, and nausea/vomiting. One patient on dose level 1 showed a partial response of 6 months in duration. Both reversible inhibition of HDJ2 farnesylation and radiosensitization of a study patient-derived cell line were demonstrated in the presence of L-778,123. K-RAS mutations were found in three of the four patients evaluated. CONCLUSIONS: The combination of L-778,123 and radiotherapy at dose level 1 showed acceptable toxicity in patients with locally advanced pancreatic cancer. Radiosensitization of a patient-derived pancreatic cancer cell line was observed. 相似文献
74.
Percutaneous nephrolithotripsy in ectopic kidneys 总被引:5,自引:0,他引:5
BACKGROUND: Percutaneous nephrolithotomy (PCNL), although an accepted treatment modality in anatomically normal kidneys, is still not universally performed for calculi in pelvic ectopic kidneys. Fear of injury to abdominal viscera makes it a technically challenging procedure. PATIENTS AND METHODS: We have performed PCNL in nine patients with calculi in pelvic ectopic kidneys. Technical factors which made this procedure safe include ultrasound-guided puncture, use of a mature tract or an Amplatz sheath, routine postoperative double-J stenting, and nephrostogram prior to nephrostomy tube removal. RESULTS: Complete stone clearance was achieved in all cases. Six patients were treated in a single stage, while three patients required two stages. Seven patients needed only one tract, and two needed two tracts. No notable complications were encountered. The average hospital stay was 5.2 days. CONCLUSION: With proper precautions and meticulous technique, PCNL is a safe and effective modality to treat calculi in pelvic ectopic kidney. 相似文献
75.
An 8-year-old boy with no evidence of von Recklinghausen's disease presented with an unusual neurinoma manifesting as a gradually progressive swelling in the suboccipital region over 2 years. The lesion was massive and had widely eroded the posterior aspects of the atlas, axis, and suboccipital bone. The tumor had involved the dura of the sigmoid and transverse sinuses, was highly vascular, and had encased the ipsilateral vertebral artery. The tumor was almost completely resected although with considerable loss of blood through a large rent in the right sigmoid sinus. This unusual benign neurinoma most probably arose from the second cervical ganglion. 相似文献
76.
We compared the tumor-initiating activities toward mouse skin of two
structurally related polycyclic aromatic hydrocarbon diol epoxides: racemic
anti-1,2,3,4-tetrahydro-5,6-dimethylchrysene-1,2-diol-3,4- epoxide
(5,6-diMeCDE) and racemic anti-1,2,3,4-tetrahydro-5-
methylchrysene-1,2-diol-3,4-epoxide (5-MeCDE). Tumors induced by these diol
epoxides were analysed for mutations in the Ha-ras gene. 5,6- diMeCDE is
derived from the non-planar parent compound 5,6- dimethylchrysene, and
reacts to approximately equal extents with dA and dG in DNA, whereas
5-MeCDE is derived from a nearly planar parent compound, 5-methylchrysene,
and reacts mainly with dG in DNA. 5,6- diMeCDE, at initiating doses of 33,
100 or 400 nmol per mouse, induced 1.2, 2.2 and 6.2 skin tumors per mouse,
respectively. It was significantly less tumorigenic than 5-MeCDE which
induced 3.1, 7.5 and 9.1 skin tumors per mouse at the same doses. Tumors
induced by 5,6- diMeCDE had a large number of CAA-->CTA mutations in
codon 61 of the Ha- ras gene: 50, 55 and 75% of the tumors analysed had
this mutation at the 33, 100 and 400 nmol doses. No mutations were found in
codons 12 and 13 in the tumors induced by 5,6-diMeCDE. In contrast,
CAA-->CTA mutations in codon 61 were rarely seen in tumors induced by
5-MeCDE. At the highest dose of 5-MeCDE, 20% of the tumors analysed had
mutations at G of codons 12 and 13. The results of this comparative study
support the hypothesis that mutations in the Ha-ras gene in mouse skin
tumors induced by PAH diol epoxides occur as a result of their direct
reaction with the gene. However, pathways other than the commonly observed
Ha- ras codon 61 mutations are clearly important in mouse skin
tumorigenesis by these diol epoxides.
相似文献
77.
PURPOSE: The detection of density differences, or "mosaic attenuation pattern," on CT images may be difficult when the regional inhomogeneity of the density of the lung parenchyma is subtle. The purpose of this work was to develop a fully automated method for the reproducible quantification of the underattenuated areas of the lung parenchyma. This technique may be useful in increasing the precision of investigation of structure/function relationships. METHOD: Anatomical segmentation was achieved by a structure-filtering operator based on mathematical morphology. To compensate for the density gradient visible on lung CT scans, a model-based iterative deconvolution filter and an adaptive clustering algorithm were developed. Validation was performed with CT images from a lung phantom, 15 patients with constrictive obliterative bronchiolitis, and 8 normal subjects. RESULTS: The accuracy of the estimate of the density gradient on phantom studies was 93.3%. The automated quantification of the areas of decreased attenuation on scans of constrictive obliterative bronchiolitis was within 8.2% from the average scoring of two experienced observers. CONCLUSION: The proposed technique is fully automated and can accurately correct for density gradient and classify areas of decreased attenuation on lung CT images. 相似文献
78.
Surgery for Syringomyelia: An Analysis Based on 163 Surgical Cases 总被引:23,自引:0,他引:23
Summary ? Object. The authors analyzed the cases of 163 patients with syringomyelia to assess the appropriate surgical procedure.
Methods. Depending on the aetiological factors and treatment considerations the series was classified into three groups. Group I were
cases where there was no definite demonstrable aetiological factor; Group II cases had basilar invagination and/or Chiari
malformation; and Group III consisted of cases where the syrinx was secondary to an obvious aetiology, such as a mass lesion
either in the posterior cranial fossa or in the spine or a severe kyphotic spinal deformity. Post-traumatic syringomyelia
and syrinx in association with spina bifida were not studied.
Conclusions. We concluded that for Group I cases syringosubarachnoid shunting is the ideal form of treatment. In Group II cases foramen
magnum bony decompression is satisfactory and physiological. Good results were obtained even in cases where either a foramen
magnum decompression alone or in combination with a syringo-subarachnoid shunt was done. Only syringosubarachnoid shunt (without
a foramen magnum decompression) in Group II cases was found to produce poor outcome. Group III cases should be treated for
the primary aetiological problem. Only syrinx drainage procedure without treatment of aetiology in these cases produced poor
results. It was observed that clinical outcome rather than radiological improvement is the reliable indicator of the surgical
result. 相似文献
79.
Archana A. Desai Vishala K. Pandya Dipesh B. Bhalani Sanjiv Desai Bhavin D. Parikh 《Indian journal of otolaryngology and head and neck surgery》2004,56(3):191-195
High-resolution sonography has improved in the past few years and has become a very valuable tool in the diagnosis of diseases
of the head and neck. Ultrasonography (US) is commonly the first imaging modality after clinical examination. It is inexpensive,
noninvasive and is easily tolerated by patients. It provides valuable diagnostic information with a high degree of diagnostic
accuracy. This article provides the most up-to-date information about the indications, findings and limitations of high-resolution
sonography in the evaluation of laryngeal and laryngopharyngeal cancers. 相似文献
80.
Influence of glucose kinetics on plasma lactate concentration and energy expenditure in severely burned patients 总被引:5,自引:0,他引:5
Gore DC Ferrando A Barnett J Wolf SE Desai M Herndon DN Goodwin C Wolfe RR 《The Journal of trauma》2000,49(4):673-7; discussion 677-8
BACKGROUND: In critically ill patients, elevation in the plasma lactate concentration has traditionally been interpreted as indicating a deficiency in oxygen availability and is often an impetus to increase oxygen delivery clinically. However, another possible basis for increased lactate concentrations may be simply a mass effect from increased pyruvate availability (i.e., accelerated glycolysis). METHODS: In six hypermetabolic burned patients, the rates of glucose production and oxidation were quantified using a tracer infusion of 6,6 d2 glucose combined with indirect calorimetry. Measurements were obtained after a 9-hour fast and after a 3-hour infusion of unlabeled glucose at 30 micromol/kg/min. No patient was overtly septic, hypoxic, or hypovolemic. RESULTS: The infusion of glucose significantly increased the arterial glucose concentration and rate of glucose oxidation, with a corresponding increase in the arterial plasma concentration of lactate and pyruvate. Resting energy expenditure and oxygen consumption were not affected by the infusion of glucose. CONCLUSIONS: These findings show that elevations in plasma lactate in severely injured patients may, in part, be related to increases in glucose flux and not entirely a reflection of any deficit in oxygen availability. Such findings highlight a potential pitfall for interpreting plasma lactate concentrations as an index of tissue oxygen availability in hypermetabolic patients. 相似文献