How to simplify the CT diagnosis of Le Fort fractures

OBJECTIVE: The numerous components seen in the Le Fort fractures make classification difficult. Our objective is to simplify the task of classifying Le Fort fractures. CONCLUSION: Each of the Le Fort fractures has at least one unique component that is easily recognizable: I, the anterolateral margin of the nasal fossa; II, the inferior orbital rim; and III, the zygomatic arch. Classification of the Le Fort fractures is simplified by using these unique components to establish a tentative classification that is then confirmed.     

The likelihood of adverse outcomes in triplet pregnancies estimated by pregravid maternal characteristics

OBJECTIVE: To estimate the likelihood of adverse outcomes in triplet pregnancies by a score comprising pregravid maternal characteristics. DESIGN: A cross-sectional study. SETTING: Triplets database collected by Matria Healthcare, Inc. PATIENT(S): A scoring system was constructed, assigning 1 point for the presence of a risk factor (nulliparity, stature <165 cm, and age <35 years) and 0 for the absence of a risk factor. Data related to 2,887 triplet sets were analyzed. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Total triplet birth weight <4,500 and delivery at 27-32 weeks. RESULT(S): We identified 18% of triplets' mothers (score 3) in whom the likelihood for adverse results is 50%-90% higher and the likelihood for optimal results is 40% to 70% lower than background rates. CONCLUSION(S): A pregravid maternal profile could estimate the likelihood of adverse outcomes and be used for consulting patients at risk of having or carrying a triplet pregnancy.     

Comparison of image quality between conventional and low-dose nonenhanced head CT

BACKGROUND AND PURPOSE: Increasing use of CT for evaluating neurologic disease may expose patients to considerable levels of ionizing radiation. We compared the image quality of low-mAs head CT scans with that of conventional nonenhanced scans. METHODS: Conventional head CT scans were obtained in 20 patients (all >65 years with history of non-CNS malignancy) by using a multidetector technique: 170 mA and 1-second scanning time (ie, 170 mAs), 140 kVp, table speed of 7.5 mm per rotation, pitch of 0.75, section thickness of 5 mm, and field of view of 25 mm. A limited volume helical data acquisition covering four 5-mm-thick images was obtained by using 90 mAs but otherwise the same parameters. Three neuroradiologists visually rated the resulting images for quality in a blinded comparison. Representative 1- to 4-mm(2) regions of interest were chosen in gray matter and white matter locations. Conspicuity and the contrast-to-noise ratio were analyzed. Statistical comparisons were done by using the Student t test. RESULTS: Mean gray matter conspicuity was not significantly different between the 170- and 90-mAs groups (0.39 +/- 0.19 vs 0.41 +/- 0.03, P =.32). Mean gray matter contrast-to-noise ratio was approximately 22% higher with 170 mAs than with 90 mAs (1.77 +/- 0.52 vs 1.39 +/- 0.38, P =.005). All 90-mAs images were rated as having slightly greater image noise than the 170-mAs scans but with sufficient perceived resolution. CONCLUSION: Although 90-mAs head CT images were moderately noisier than 170-mAs images, they were rated as having acceptable diagnostic quality.     

Radiation dose is reduced with a single-pass whole-body multi-detector row CT trauma protocol compared with a conventional segmented method: initial experience

Radiation dose data were collected from a calibrated multi-detector row computed tomographic (CT) scanner during trauma CT. One protocol (used with 10 case subjects) involved a single-pass continuous whole-body acquisition from cranial vertex to symphysis pubis, while the other, conventional protocol (used with 10 control subjects) involved scouting and scanning body segments (head, cervical spine, chest, abdomen, and pelvis) individually. Technical factors were kept constant within each body segment for the single-pass and the segmented protocols. Statistics included univariate analysis, two-tailed t testing to evaluate statistical significance of the summary statistic, and power and subject population contingency tables. The mean dose length product (DLP) with the single-pass protocol was 17% lower than the sum of the DLPs of each of the individual body segment scans (P <.001). Analysis of power and subject population by using a difference in mean of 500 mGy. cm and an alpha of.05 revealed a (1-beta) of higher than 0.90 for a sample of 10 patients. Thus, a whole-body single-pass trauma protocol, compared with a typical segmented acquisition protocol matched for imaging technique, resulted in reduced total radiation dose. The reduction in radiation dose is thought to represent a reduction in redundant imaging at overlap zones between body segments scanned in the segmental protocol but not in the continuous acquisition.     

Cerebral fractional anisotropy score in trauma patients: a new indicator of white matter injury after trauma

OBJECTIVE: Previous studies evaluating quantitative cerebral white matter diffusion anisotropy indexes have shown alteration in patients after trauma. To date, no clinically applicable scale exists by which to gauge and test the relevance of these findings. We propose the cerebral fractional anisotropy score in trauma (C-FAST) as an index of white matter injury, and we correlate C-FAST with several predictor and outcome variables. MATERIALS AND METHODS: Fifteen patients were randomly selected from the trauma surgery service. Thirty control patients were randomly selected from the emergency department. All patients were subjected to MRI evaluation, including a diffusion-weighted sequence. Data extracted from the record of each subject included Glasgow Coma Scale, revised trauma score, Abbreviated Injury Scale, initial head CT results, patient disposition, length of hospital stay, and length of stay in intensive care unit. Region of interest measurements were made in fractional anisotropy maps in each of 12 white matter regions. Univariate statistics and a two-tailed t test were performed on the raw fractional anisotropy data. Data were then dichotomized using thresholds from univariate statistics. A C-FAST score was devised from the dichotomized data. Logistic regression analyses were performed among the C-FAST, outcome, and predictor data. RESULTS: Good correlation was noted between the C-FAST and death, hospital stay greater than 10 days, and intensive care unit stay greater than 5 days. Correlation with discharge to rehabilitation facility was good when adjusted for age and sex. Glasgow Coma Scale, revised trauma score, and Abbreviated Injury Scale show good correlation as predictors of a critical C-FAST. CONCLUSION: The C-FAST is a promising index derived from MRI diffusion fractional anisotropy measurements that shows successful correlation with outcome and predictor variables. A larger investigation is needed to verify the validity and stability of the correlations.     

Metabolism of homoharringtonine,a cytotoxic component of the evergreen plant Cephalotaxus harringtonia

Homoharringtonine (HHT), first isolated from the Chinese evergreen Cephalotaxus harringtonia, has been demonstrated to have a broad antitumor activity in rodents and antileukemic effects in humans. We found that HHT was metabolized to an acid product [HHT-acid; 2'-hydroxy-2'-(alpha-acetic acid)-6'-hydroxy-6'-methylheptanoyl cephalotaxine] when incubated with either human plasma or mouse plasma in vitro. The conversion was faster, however, in mouse plasma, and was both time- and temperature-dependent. Boiled plasma prevented the conversion of HHT to HHT-acid, suggesting that the conversion was enzymatically mediated. When mice were given an intravenous (i.v.) injection of HHT (4 mg/kg), the HHT-acid metabolite was found in both plasma and urine. In mice, HHT-acid was detected in the plasma within 5 min of the i.v. injection of HHT and declined rapidly thereafter. The initial half-lives (t 1/2 alpha) of HHT and HHT-acid were 9 and 17 min, respectively. Twenty-four hours after HHT dosing in mice, approximately 29% of the dose was excreted in the urine as HHT and 20% as HHT-acid. High-pressure liquid chromatography and mass spectrometry were used to confirm the identity and quantify HHT and its metabolite, HHT-acid. The HHT concentration inhibiting 50% of the growth of human leukemic HL-60 cells was 20 ng/ml, while for HHT-acid it was 14,500 ng/ml, indicating that the acid form was more than 700 times less cytotoxic than HHT. The lethal dose of HHT affecting 50% (LD50) of mice was 6.7 mg/kg, but HHT-acid produced no apparent toxic effects at doses up to 280 mg/kg.     

Asthma in children: Management practices among paediatricians and family physicians

OBJECTIVE:

To ascertain the variation in asthma management practices among paediatricians and family physicians to determine how to improve care.

DESIGN:

Questionnaire study of paediatricians and family physicians that focused on the use of beta₂-agonists, inhaled corticosteroids, patient asthma education, quantitative measurements of airflow and diagnostic investigations for asthma. Case scenarios were used in the questionnaire.

RESULTS:

The response rate was 66% (415 of 632) among paediatricians and 42% (1156 of 2750) among family physicians. In general, both groups followed consensus guidelines. There were some differences in management practices among paediatricians and family physicians. Paediatricians were more likely to develop an action plan and less likely to use xanthines or inhaled anticholinergic agents. However, family physicians were more likely to use spirometry or home peak expiratory flow rates to make a diagnosis of asthma.

CONCLUSION:

Family physicians and paediatricians require a different focus on educational interventions to improve the care of children with asthma.     

Imprint cytology versus frozen section: intraoperative analysis of sentinel lymph nodes in breast cancer

Background: Intraoperative analysis of the sentinel node status in breast cancer adds the benefit of proceeding to axillary dissection at the same time as the primary breast operation, without the need for a second trip to theatre. However, the method of intra­operative analysis must be both rapid and accurate for use in this setting. Methods: A prospective series of 20 consecutive patients in one hospital who underwent sentinel node biopsy was performed. Intraoperative evaluation by imprint cytology and frozen section was compared with the final histopathological results. The time taken for both procedures was recorded. Results: A total of 21 sentinel node procedures was performed. The sentinel node was found in 20 procedures (95%). The average time to perform intraoperative pathological analysis was 17 min (range: 5?35 min). Of the eight positive sentinel nodes, five were positive on imprint cytology alone and five were positive on frozen section alone (62.5% accuracy). The statistical false negative rate was 18.8% and the ‘false reassurance rate’ (patients with an initially negative node that was subsequently positive on formal histology who required a second trip to theatre for axillary dissection) was 37.5%. All patients with a negative sentinel node had a negative axilla. Conclusions: Intraoperative analysis of sentinel lymph nodes in breast cancer can be performed quickly. Imprint cytology and frozen section show comparable accuracy in predicting sentinel node status.     

Acyloxymethyl acidic drug derivatives: in vitro hydrolytic reactivity

A series of acyloxymethyl drug derivatives of the NH-acidic drugs, phenytoin and theophylline and of the carboxylic acid drugs, thioctic acid and indomethacin, were prepared in order to determine the effect of varying the nature of the drug on the in vitro rate of hydrolysis catalyzed by porcine liver esterase and human plasma. The acyl portion was comprised of either valeric acid (val) or γ-linolenic acid (GLA). With the exception of some GLA prodrugs, the derivatives displayed first-order kinetics in both enzyme systems. The NH-acidic drug derivatives were hydrolyzed faster than the carboxylic drug derivatives by porcine liver esterase and human plasma. It was found that the short chain valeric acid derivatives were hydrolyzed faster than the GLA derivatives. The rates of hydrolysis for the relatively smaller prodrugs of theophylline and thioctic acid were greater than the rates of hydrolysis for the bulkier phenytoin and indomethacin prodrugs indicating steric hindrance was important. The lipophilicity index, log K, of the valeric acid drug derivatives was plotted against the logarithm of the hydrolysis rate constant, k, and it was observed that log k decreased with an increase in log K. A comparison of these results with those of previous studies where the alkyl and acyl moieties were varied of acyloxyalkyl theophylline derivatives has provided a rationale, based on lipophilicity, for the structure of a prodrug to be designed based on an in vitro desired rate of hydrolysis.