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1.
The precision of a new procedure predicting skeletal maturity on the basis of frontal sinus development was tested in 59 boys with an Angle class-II division-1 malocclusion. Lateral head films were used for the analysis of frontal sinus development, and handwrist radiographs were used for the assessment of skeletal maturity. The results showed that skeletal maturity could be predicted with a certainty of about 85% when using a 1-year prediction interval and with a certainty of about 75% when using a 2-year prediction interval. In conclusion, the study showed that skeletal maturity can be predicted with rather high accuracy by means of the analysis of frontal sinus development as imaged on lateral headfilms.  相似文献   

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JJ Tepas  JC Patel  C DiScala  RL Wears  HC Veldenz 《Canadian Metallurgical Quarterly》1998,44(5):827-30; discussion 830-1
OBJECTIVES: Five years experience recorded in a multi-institutional pediatric trauma registry was analyzed to define the relationship between case volume and outcome as measured by mortality. METHODS: A total of 30,930 records with complete data were categorized by contributing hospital. Patients with fatal injury as indicated by an injury severity score of 75 or any abbreviated injury scale of 6 were excluded. Each center's experience was stratified by injury severity using injury severity score > or = 15 as indicative of severe injury. Centers were then classified as low volume (LV, 100-500 cases), mid volume (MV, 501-1,000 cases), or high volume (HV, > 1,000 cases). Proportion of patients with severe injury (injury severity score > 15) and mortality were compared among groups using the chi(2) test with significance accepted at p < 0.05. Using the Pediatric Risk Indicator to adjust for mortality risk, the combined hospital experience of each volume group was further analyzed to assess performance with specific levels of increasing injury severity. RESULTS: Findings demonstrated a trend of increasing mortality with increasing volume, despite a consistent proportion of severe injury. Risk adjusted mortality for each volume class indicates best outcome in the mid level group. CONCLUSIONS: Regardless of overall volume of patients encountered, there is a consistent proportion of severe injury. The increasing mortality with the most severe injuries seen in the high volume centers may reflect overdemand on resources.  相似文献   

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Cyclic and polycyclic oligonucleotides were synthesized using chemical ligation. Two types of catenanes with one and several intertwinings were produced. The yield of these molecules depended on the ligation conditions and nucleotide sequence of the ligated oligonucleotide and its template. Structure of ligation products was investigated and confirmed using restriction endonuclease MvaI. Interaction of the synthesized molecules with restriction endonucleases SsoII, EcoRII and HindIII was also studied.  相似文献   

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This report describes a new statistical method for estimating the MIC of fluconazole for yeasts pathogenic to humans. This method is based on comparison of the colony sizes on solid media containing different concentrations of fluconazole. By this method, the MICs of fluconazole for 10 yeast strains were comparable to results obtained by the standard method recommended by the National Committee for Clinical Laboratory Standards. This method is simple to perform and easy to interpret. The turnaround time is faster than other methods. The method should be applicable to the determination MICs of other antifungal drugs for yeasts.  相似文献   

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The gene coding for the immunity protein (mceB) and the structural gene of microcin E492 (mceA), a low-molecular-weight channel-forming bacteriocin produced by a strain of Klebsiella pneumoniae, have been characterized. The microcin gene codes for a precursor protein of either 99 or 103 amino acids. Protein sequencing of the N-terminal region of microcin E492 unequivocally identified this gene as the microcin structural gene and indicated that this microcin is synthesized as a precursor protein that is cleaved at either amino acid 15 or 19, at a site resembling the double-glycine motif. The gene encoding the 95-amino-acid immunity protein (mceB) was identified by cloning the DNA segment that encodes only this polypeptide into an expression vector and demonstrating the acquisition of immunity to microcin E492. As expected, the immunity protein was found to be associated with the inner membrane. Analysis of the DNA sequence indicates that these genes belong to the same family as microcin 24, and they do not share structural motifs with any other known channel-forming bacteriocin. The organization of the microcin- and immunity protein-encoding genes suggests that they are coordinately expressed.  相似文献   

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Polyvinylidene fluoride (PVDF) represents an attractive alternative to polypropylene as a monofilament vascular suture because of its satisfactory physicochemical properties, it ease of handling, and its good biocompatibility. However, the polymer's ability to remain mechanically and chemically stable when exposed to a mild hydrolytic environment over the long term has yet to be demonstrated. One in vitro study involved the comparison of the long-term relative resistance of PVDF and polypropylene sutures to hydrolysis for a period of 9 years. The PVDF suture showed major molecular rearrangements from the original ratio of three crystalline structures to the single beta crystalline phase. The observation of some surface oxidation and water inhibition did not significantly modify the tensile strength of the PVDF suture, which retained 92.5% of its original value. In contrast, the polypropylene sample did not undergo any recrystallization but was associated with more oxidation byproducts and more water molecules near the surface, which contributed to a 46.6% loss in initial tensile strength. An in vivo study confirmed that PVDF sutures are biocompatible and are able to maintain satisfactory biostability when used to anastomose thoracic aortic allografts for a period of 6 months in the dog. The cellular reaction of fresh allografts as well as the control autografts to PVDF sutures was minimal. In other allografts that had been preserved in a supplemented medium for 1 week prior to implantation, the PVDF sutures healed satisfactorily with the formation of neocollagen and few macrophages surrounding the monofilament. No evidence of instability at the allograft-host artery junction was observed, confirming that the PVDF sutures were able to ensure a secure anastomosis in the thoracic aorta. PVDF sutures have demonstrated superior long-term biostability in vitro and minimal tissue response in vivo. These are two essential requirements when evaluating the use of a suture for vascular surgery in general and thoracic aortic surgery in particular.  相似文献   

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Malnutrition and morbidity have a synergistic association that often leads to death. However, malnutrition in children who die is largely underreported, because anthropometry of the deceased child is rarely known. This study had two purposes: i) to develop a scale that would help determine if a child had low weight-for-age (w/a), in the absence of anthropometric measures; and ii) to select an appropriate cut-off that would give the best sensitivity (Se) and specificity (Sp) of the proposed scale when contrasted with actual w/a measurement. The study was designed as a diagnostic test, and carried out in a rural area in central Mexico. We included 132 children under 5 y old with w/a under -2 Z score and 284 children with marginal or no w/a deficit as a control group. The proposed scale included potential predictive variables from clinical, socioeconomic and family factors. The best logistic regression model to predict low w/a included: birth weight less than 2,800 g, introduction of weaning foods after the sixth month of life, introduction of animal protein after the sixth month of life, low socioeconomic status, low w/a in siblings and more than three morbidity episodes in the previous 6 mon. Selecting a cut-off of 4 for this model to identify children with low w/a showed a Se and Sp of 85 and 95%, respectively. We tested the external validity of the scale in a different locale, and included 877 children under 5 y old from 10 rural communities. In this population, the scale showed Se of 84% and Sp of 81% to identify low w/a. Based on these results, we propose that the scale be included as a means of identifying low w/a in children who have died. We believe that this should be done in verbal autopsies, which, based on our previous research, the Ministry of Health adopted as part of the regular activities to monitor problems in the disease to health-seeking to death process.  相似文献   

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The objectives of our study were to (1) assess the outcomes resulting from the use of sonography in patients referred to our institution's ultrasound laboratory for an elevated serum creatinine level and (2) determine relevant clinical parameters in these patients to better triage them for sonography. We retrospectively identified and determined outcomes of 60 patients (20 women, 40 men; mean age, 61 years; range, 33 to 100 years) referred for sonographic evaluation because of an increased serum creatinine level (> or = 1.3 mg/dL). Ultrasound findings (hydronephrosis, renal size, and echogenicity) were correlated with clinical outcomes. Twenty-one patients (35%) had hydronephrosis, with 14 of these patients confirmed to be obstructed and five not obstructed. Two were indeterminate for obstruction. Eight of 14 obstructed patients were successfully treated. All obstructed patients had a suggestive history for obstruction with at least one of the following: pelvic mass (n = 9), stone disease (n = 4), or flank pain (n = 1). Only 2 of 44 patients, who were not obstructed, had any of these parameters (statistically significant difference, P < 0.0001). Thirty of the patients, who were not obstructed, had more likely alternative causes for renal failure, with sonography having no effect on patient management. Renal size and echogenicity had little effect on patient management. Sonography was efficacious in guiding management in patients with a suggestive history for obstruction (eg, pelvic mass, stone disease, or flank pain) but not in most patients who had no suggestive history and other more likely causes for renal failure.  相似文献   

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Heparin is clinically administered mainly by intravenous injection because of its highly hydrophilic property. A slightly hydrophobic heparin derivative which can be dissolved in organic solvent can be widely used in polymeric devices for clinical applications. In this study, hydrophobic heparin derivatives were prepared by coupling heparin with deoxycholic acid, cholesterol, lauric acid, and palmitic acid, respectively. The hydrophobicity of these heparin derivatives depended on the feed mole ratio of heparin to hydrophobic agents, and they showed good solubility in the co-solvent of acetone and water, as well as in water alone. Also, these heparin derivatives showed high anticoagulant activity. This approach for preparing hydrophobic heparin is expected to advance the drug delivery system by further extending the applications of heparin to medical devices such as cardiopulmonary bypass circuits, heart lung oxygenators, and kidney dialyzers.  相似文献   

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Examined the prediction of child psychotherapy outcome from client, parent, and process factors specific to the therapeutic relationship. 31 children (mean age 11 yrs) were assessed by some independent and therapist ratings, as were parental behaviors, at admission and at discharge from a community mental health center. The primary diagnoses were adjustment disorder (89%) and functional enuresis (11%). Process was evaluated by therapist ratings on the Psychotherapy Process Inventory by P. E. Baer et al (see record 1981-11629-001). Results support the importance of treatment dosage and client participation to global change in impairment and are consistent with findings of B. Gomes-Schwartz (see record 1979-26509-001). Change (decrease) in the severity of Ss' primary problem through treatment was predicted by less frequent parental psychological punishment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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Biochemical changes related to skeletal turnover in puberty were investigated in a sample of 67 girls aged 8-14 years. The following biochemical parameters were measured in serum: total calcium, phosphate, magnesium, total alkaline phosphatase, osteocalcin, and calcium and hydroxyproline in the second morning urine. Thirty-five premenarchal girls (8-11 years) had significantly lower serum calcium, and higher alkaline phosphatase and phosphate than those menstruating regularly (N = 32, 12-14 years). A statistically significant negative correlation of serum parameters and age was found for phosphate and alkaline phosphatase in all subjects, and for calcium and magnesium only in the premenarchal girls. These results indicated the more intensive processes of skeletal metabolism occurring in prepubertal age and early puberty to reflect in basic biochemical parameters of calcium and bone metabolism. Analysis of correlation between biochemical parameters showed alkaline phosphatase and phosphate to correlate positively with hydroxyproline excretion and negatively with urinary calcium in all subjects. In the subjects after menarche, osteocalcin correlated with alkaline phosphatase and phosphate. Thus, biochemical parameters indirectly reflected physiologic changes occurring with bone turnover in puberty. Variations in bone turnover during puberty, including a more pronounced bone formation during prepubertal or early stages, can be indirectly observed through biochemical parameters related to calcium and bone metabolism. Investigations of skeletal growth and puberty would benefit from specific markers of bone remodeling and "basic" biochemical parameters, as it might disclose subtle metabolic relationships.  相似文献   

14.
We have investigated the possibility of measuring autoantibodies to IA-2 (IA-2A) using recombinant protein expressed in E. coli in a new radioassay. The intracellular part of IA-2 (IA-2ic) was expressed in E. coli as a biotinylated fusion protein and affinity-purified on a streptavidin column. The average yield of IA-2ic was about 1 mg purified protein from one litre of culture medium with E. coli. We could demonstrate the immunological activity of this material by blocking the autoantibody reactivity to in vitro synthesised IA-2ic. The IA-2ic fusion protein was then radiolabelled with 125I, purified by HPLC, and used in an immunoprecipitation assay for the detection of IA-2A. Sera from 46 of 68 (67%) patients with Type-I diabetes were positive by this radioassay, in contrst to only 2 of 50 (4%) patients with autoimmune thyroid disease and 1 of 114 (1 %) controls. There was a correlation between this radioassay and the previously established radioligand assay using synthesized 35S-methionine-labelled IA-2ic in vitro (r = 0.79, p < 0.001). We conclude that E. coli-derived IA-2 has the correct immunogenic conformation, and can be used for the detection of IA-2A with a similar sensitivity and specificity as the validated radioligand assay. This new assay can facilitate the measurement of IA-2A in routine laboratories where the radioligand assay is inconvenient or not available.  相似文献   

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BACKGROUND: Despite having appropriate sonographic equipment available many radiologists remain unfamiliar with B mode sonography of the eye. OBJECTIVE: This article reviews the advantages and disadvantages of B mode sonography of the paediatric eye. We illustrate the spectrum of eye abnormalities occurring in paediatric practice and the sonographic appearance of clinical entities for which sonography is appropriate. MATERIALS AND METHOD: We reviewed our experience of eye sonography within a paediatric radiology department over 8 years. A total of 212 sonographic examinations were performed on 206 eyes in 103 children, aged from 3 days to 16 years (mean 4.6 years). RESULTS: Sonography was well tolerated by the children, was a very useful imaging modality and was the only diagnostic imaging modality required in 94%. Supplementary computed tomography (CT) was performed in ten of 206 eyes (5%) and magnetic resonance imaging (MR) was performed in two of 206 eyes (1%). CONCLUSIONS: B mode sonography is a very useful imaging modality for suspected ocular or orbital pathology in children and is often the appropriate first line investigation following clinical evaluation. Radiologists familiar with sonography of the eye can provide valuable support to their ophthalmology colleagues.  相似文献   

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The sample-volume length (SVL) of an embolic signal has previously been used to differentiate between gaseous and particulate emboli and has been calculated using high-resolution Wigner analysis. Although successful, this method of analysis is not widely available to other groups using transcranial Doppler ultrasound (TCD) to classify emboli. The SVL of embolic signals can also be calculated using time domain analysis, which is a far simpler method and potentially available to all TCD users. The aim of this study was to compare the SVL of embolic signals calculated using Wigner analysis and time domain analysis to assess whether or not time domain analysis can replace Wigner analysis to classify emboli. In total, 215 particulate and 100 gaseous emboli were recorded onto digital audiotape and analysed off-line. Two SVLs for each embolic signal were calculated by measuring embolic duration and velocity in the time domain and with Wigner analysis. Receiver operator characteristic (ROC) curves were plotted to assess the optimum SVL threshold for each method, and levels of sensitivity and specificity were defined. The optimum SVL threshold using Wigner analysis was 1.28 cm, yielding 93% sensitivity and 97% specificity. Using time domain analysis, the optimum threshold was 1.12 cm, yielding 90% sensitivity and 96% specificity. The methods were compared statistically (chi2) using their optimum thresholds, and were found not to be statistically different for classifying particles p=0.283) or gaseous emboli (p=0.700). This study has shown that the SVL of embolic signals, used to differentiate particulate from gaseous emboli, can be calculated more simply in the time domain, which yields as accurate results as calculating the SVL using Wigner analysis.  相似文献   

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The alterations in autonomic tone imposed by the conduct of anesthesia and surgery predispose patients to ventricular ectopy. It is important to initially view any ectopy as a warning sign and promptly check the adequacy of ventilation and oxygenation. Most commonly an inadequate depth of anesthesia, surgical manipulation or electrolyte abnormality will be causative. Treatment of this underlying problem will usually suffice to terminate the ectopy. Importantly, many patients have preexisting, chronic, complex ventricular ectopy that gets revealed because of perioperative electrocardiographic monitoring. All available pharmacologic agents have significant adverse side effects. To date, all investigations examining outcome of suppression of ventricular ectopy show that successful suppression of ventricular ectopy was associated with an increased mortality. Although the prognosis for patients is worse when complex ventricular ectopy is associated with cardiac structural abnormalities, the optimal therapeutic approach to such patients remains undefined. Unless new data supporting the use of antiarrhythmic drugs in the perioperative setting become available, the risk to benefit ratio is considered unfavorable.  相似文献   

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The ratio of the lengths of the second and fourth fingers (2D:4D) may serve as a marker for prenatal androgen signaling. Because people are typically unaware of their 2D:4D, its use allows possible effects of early sex hormone regimes and socialization to be disentangled. We conducted a meta-analysis on relationships between 2D:4D and sexual orientation in men and women in 18 independent samples of men and 16 independent samples of women. Collectively, these samples comprised 1,618 heterosexual men, 1,693 heterosexual women, 1,503 gay men, and 1,014 lesbians. In addition to identifying the normative heterosexual sex difference in 2D:4D for both hands, we found that heterosexual women had higher (more feminine) left- and right-hand 2D:4D than did lesbians, but we found no difference between heterosexual and gay men. Moderator analyses suggested that ethnicity explained some between-studies variation in men. These results add to a literature suggesting that early sex hormone signaling affects sexual orientation in women, and highlight the need for further research exploring the relationships among 2D:4D, sexual orientation, and ethnicity in men. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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We describe a new method for assessing the Ca/P ratio of bone in vivo using gamma-ray photon absorptiometry. The theoretical approach of the method and the estimation of the variance are presented. Two radiation sources, Gd-153 (100 keV), and I-125 (27.5 keV), and a germanium detector were used to determine this ratio. Measurements were made on bone phantoms with different Ca/P ratios; also, the ratio was measured on lamb and sheep tibias, rabbit tibias, and human fingers. Since the accuracy of the method is affected by the amount of fat and collagen in the measurement field, the effect of collagen and fat on the measurements also was investigated. In all cases, the precision of the method, expressed as the coefficient of variation (CV): 100x standard deviation/mean, was near to the theoretical one, ranging from 1.8% to 3.2%. For human fingers, the CV was 3.2%, a value near to the theoretical 2.9% with a dose to the skin ranging from 0.044 to 0.066 mGy, depending on the width of the finger.  相似文献   

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