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KA McGovern JS Schoeniger JP Wehrle CE Ng JD Glickson 《Canadian Metallurgical Quarterly》1993,29(2):196-204
Oxygenation is a major determinant of the physiological state of cultured cells. 19F NMR can be used to determine the oxygen concentration available to cells immobilized in a gel matrix by measuring the relaxation rate (1/T1) of perfluorocarbons (PFC) incorporated into the gel matrix. In calcium alginate gel beads without cells the relaxation rate (1/T1) of the trifluoromethyl group of perfluorotripropylamine (FTPA) varies linearly with oxygen concentration, with a slope of 1.26 +/- 0.15 x 10(-3) s-1 microM-1 and an intercept of 0.50 +/- 0.04 s-1. During perfusion with medium equilibrated with 95%/5% O2/CO2, changes in PFC T1s indicate that the average oxygen concentration was reduced from 894 +/- 102 microM in the absence of cells to 476 +/- 65 microM and 475 +/- 50 microM in the presence of 0.7 x 10(8) EMT6/Ro and RIF-1 murine tumor cells per milliliter of gel, respectively. The presence of 0.2 microliters of FTPA/ml of gel had no effect on the energy status of the cells as indicated by 31P NMR spectra. To calculate oxygen gradients within the beads from the average PFC T1 of the sample, a mathematical model was used assuming that oxygen is the limiting nutrient for cell metabolism and that the cellular oxygen consumption rate is independent of oxygen concentration. Data for EMT6/Ro cells were fit using experimentally determined perfusion parameters together with literature values for cell volume and oxygen consumption rate.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
33.
AS Agro ET Garner JW Wright I Caballeros de Escobar B Villeda M Seidlin 《Canadian Metallurgical Quarterly》1998,20(4):744-759
A multicenter, open-label prospective trial was performed to determine the clinical and microbiologic efficacy of ofloxacin (OFLX) otic solution in the treatment of subjects > or =12 years with chronic suppurative otitis media (CSOM) and a chronically perforated tympanic membrane in the infected ear(s). A total of 207 patients at 27 centers in the United States and Central America received OFLX 0.5 mL instilled ototopically twice daily for 14 consecutive days. The primary clinical end point was cure (dry ear) or failure (not dry ear). The primary microbiologic end point was eradication of baseline pathogens. Because there was no comparator and there were few data in the literature regarding clinical efficacy in patients treated with other regimens, the efficacy of OFLX was compared with data recorded in the clinical records of historical-practice control (HPC) or current-practice control (CPC) subjects. The incidence of clinical cure in clinically evaluable OFLX-treated patients (91%; 148 of 162 subjects) was significantly higher than in HPC subjects (67%; 124 of 185 subjects) or CPC subjects (70%; 38 of 54 subjects). OFLX eradicated all baseline pathogens isolated in microbiologically evaluable subjects. These pathogens were predominantly Staphylococcus aureus, Pseudomonas aeruginosa, and Proteus mirabilis. The most common treatment-related adverse event, bitter taste, occurred in 17% (35 of 207) of OFLX-treated subjects. Thus OFLX 0.5 mL administered twice daily for 14 days was effective in resolving the signs and symptoms of CSOM in subjects > or =12 years, was significantly more effective than therapies used to treat HPC or CPC subjects, and was well tolerated. 相似文献
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Thirteen hundred and fifty dogs were examined under anesthesia at veterinary hospitals in the USA and Canada. Periodontal health was recorded in detail. Teeth were frequently absent (particularly lower third molar, upper and lower first premolars, and incisor teeth). Calculus was most extensive on the upper fourth premolar and molar teeth. Missing teeth, mobility of remaining teeth, extent of calculus and gingival inflammation, and furcation exposure and attachment loss all were more common in small dogs compared with larger dogs, and in order dogs compared with younger dogs. 相似文献
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Perchloric acid (70%) was used to create simulated periapical lesions in tooth sockets of 15 dentate cadaver jaw specimens. Using the Trophy USA direct digital radiographic system, linear images were captured at selected time intervals after initial acid application and altered by contrast reversal, pseudocolor enhancement, and two forms of histogram equalization. The 525 total images were randomized for display on a computer monitor for evaluation by five endodontists. Images were evaluated twice by each rater, with viewings 1 to 2 wk apart. Statistical analysis determined interrater variability, intrarater reproducibility, and the relative merits of each enhancement technique. At 8, 12, 16, and 24 h after acid application, both techniques of histogram equalization yielded a statistically significant improvement over reverse contrast in perception of periapical patholais. Linear and pseudocolor-enhanced images were also significantly more diagnostic than reverse contrast at 12, 16, and 24 h. Intrarater reproducibility showed moderate agreement, but analysis showed only a fair level of interrater agreement. 相似文献
38.
LM East CJ Savage JL Traub-Dargatz CE Dickinson RP Ellis 《Canadian Metallurgical Quarterly》1998,212(11):1751-1756
OBJECTIVE: To identify clinical signs, physical examination findings, results of diagnostic tests, treatments administered, and clinical outcome of neonatal foals with enterocolitis associated with Clostridium perfringens infection. DESIGN: Retrospective study. ANIMALS: 54 neonatal foals. RESULTS: Most foals had acute onset of obtunded mentation, colic, or diarrhea and developed leukopenia, neutropenia, an abnormally high number of band neutrophils, toxic WBC, and hypoproteinemia within 24 hours after admission, despite high serum IgG concentrations (> 800 mg/dl). Abdominocentesis and abdominal radiography of some foals revealed exudative peritonitis and gaseous distention of the small and large intestine, respectively. Cytologic examination of feces revealed spores or gram-positive rods in 8 of 10 foals. The most common genotypes of C perfringens isolates were type A and C, alone or in combination. Treatment did not alter mortality rate for most foals that had a positive culture for C perfringens type C. Of 54 foals, 29 (54%) that had C perfringens-associated enterocolitis died. Foals that had a culture that yielded C perfringens had higher sepsis scores, IgG concentrations, and mortality rates, compared with the overall hospital population of neonatal foals. CLINICAL IMPLICATIONS: Foals less than 7 days old that have enterocolitis associated with C perfringens infections, especially type C, have a guarded prognosis. Cytologic examination of feces to determine spore counts and detect rods may be a means for early identification of C perfringens infections. Polymerase chain reaction assays to determine genotype are important for designing preventive treatment regimens. 相似文献
39.
The postpartum period is an ideal time to begin contraception, as women are more highly motivated to adopt contraception at this time and it is convenient for both patients and service providers. For intrauterine device (IUD) contraception, this period offers other advantages, such as ease of insertion and minimal adverse impacts on breastfeeding. Among early studies, most postpartum insertions were performed anywhere from a few hours to seven days or more after delivery, and retention of the IUD in the uterus was poor. Since the 1970s, immediate postplacental insertion (IPPI), i.e., IUD insertion performed within 10 minutes after placental delivery, has been advocated, and fairly, low expulsion rates have been reported. Up to now, IPPI has not been widely accepted in clinics because its expulsion rate still appears to be higher than that of interval insertion. In order to further study IPPI and perfect this contraceptive technique, it is essential to comprehensively review IPPI results and compare the Chinese experience with that of the rest of the world. 相似文献
40.
S Nielsen A Schmitz RE Knudsen J Dollerup CE Mogensen 《Canadian Metallurgical Quarterly》1994,87(12):747-754
In a double-blind, double-dummy, randomized, multi-centre study, the effects of bendroflumethiazide vs. enalapril on blood pressure, glycaemic control, lipoprotein concentrations and albuminuria were compared in non-proteinuric, hypertensive type 2 diabetic patients; they were treated for 20 weeks with either bendroflumethiazide 2.5-5.0 mg (n = 59) or enalapril 10-20 mg (n = 55). Age, fasting plasma glucose, HbA1c and BMI were similar in the groups. Systolic and diastolic blood pressure were reduced in both groups. Bendroflumethiazide was accompanied by minor but significant elevations in fasting plasma glucose and serum C-peptide. HbA1c was increased during both treatments. Lipoproteins and urinary albumin/creatinine ratio were stable. Bendroflumethiazide caused a decrease in serum potassium and an increase in serum urate. No significant correlations were observed between the decline in blood pressure and changes in the metabolic risk factors. Baseline levels of age, sex, BMI, blood pressure or urinary albumin/creatinine ratio were not related to changes in blood pressure, metabolic parameters or urinary albumin/creatinine ratio. 相似文献