The poor quality of early evaluations of magnetic resonance imaging

To study the quality of early research on the clinical efficacy of diagnostic imaging with magnetic resonance, we assessed 54 evaluations published in the first four years after introduction of this modality using ten commonly accepted criteria of research methodology. The terms sensitivity, specificity, false-positive or false-negative, accuracy, and predictive values were used infrequently. Nineteen percent of the evaluations used three terms appropriately, 48% used one or two terms, and 33% used none. Data were presented appropriately for one or more of the five terms in 59% of evaluations. A "gold standard" comparison with the results of an independent procedure, such as surgical or autopsy findings, was presented in 22% of evaluations. Results of another imaging procedure were described in 63% of evaluations. Only one evaluation clearly described a prospective study design, although 11 evaluations apparently were planned in advance. Not one evaluation contained an appropriate statistical analysis of the distributions of quantitative readings, "blinded" image readers to diagnosis or other test results, measured observer error, or randomized the order of magnetic resonance imaging and other imaging procedures. We conclude that health care professionals paying for expensive innovative diagnostic technology should demand better research on diagnostic efficacy.     

Ultrasonigraphic Evidence of Abnormal Lymphatic Vessels in Young Men with Adult Wuchereria Bancrofti Infection in the Scrotal Area

Purpose

We determined the prevalence and magnitude of dilatation of the lymphatic vessels of the spermatic cord in men infected with Wuchereria bancrofti, which is a known major cause of hydrocele in the tropics.

Materials and Methods

Scrotal ultrasound was performed with a 7.5 MHz, transducer in 78 men from Recife, Brazil (endemic for filariasis) and in 15 from a nonendemic area.

Results

Among men from Recife the lymphatic vessels were dilated (1.3 to 15.0 mm., mean 3.8) at the location of the adult worm. Vessel diameter was not associated with hydrocele.

Conclusions

Lymphatic dilatation was observed in all men with ultrasonographically detectable W. bancrofti infection, even those who were asymptomatic.     

Characteristics of Contraceptive Use in Sao Paulo State, Brazil

Objective To know the characteristics of contraceptive use in Sao Paulo State collected by the Demographic and Health Survey （DHS） conducted in 1996. Methods Data of Sao Paulo in 1996 were analyzed compared with the previous DHS carried on in 1986focusing on Sao Paulo State. Contraceptive use among married or cohabiting women by age, number of children and schooling was closely examined. Age and timing of female sterilization were also analyzed. Results The results showed that unlike Brazil there was a stability of female sterilization in Sao Paulo State during 1986 and 1996. There was a pattern in Sao Paulo： up to 30 years old the pill was the most used contraceptive, after 30 there was a predominance of female sterilization, which increased with the number of children and decreased with schooling. The use of male methods had also increased in the 1986 and 1996 period, being greater in Sao Paulo than in Brazil. Sao Paulo also presented more diversity in the use of reversible contraceptives. Conclusions The predominant two contraceptive methods in Brazil and Sao Paulo changed from 1986 to 1996, i.e..from pill to female sterilization.     

Fast Face Recognition Via Sparse Coding and Extreme Learning Machine

Most face recognition approaches developed so far regard the sparse coding as one of the essential means, while the sparse coding models have been hampered by the extremely expensive computational cost in the implementation. In this paper, a novel scheme for the fast face recognition is presented via extreme learning machine (ELM) and sparse coding. The common feature hypothesis is first introduced to extract the basis function from the local universal images, and then the single hidden layer feedforward network (SLFN) is established to simulate the sparse coding process for the face images by ELM algorithm. Some developments have been done to maintain the efficient inherent information embedding in the ELM learning. The resulting local sparse coding coefficient will then be grouped into the global representation and further fed into the ELM ensemble which is composed of a number of SLFNs for face recognition. The simulation results have shown the good performance in the proposed approach that could be comparable to the state-of-the-art techniques at a much higher speed.     

Root canal microorganisms and their antibiotic susceptibility in patients with persistent endodontic infections,with and without clinical symptoms

Odontology - Secondary/persistent infections are present in teeth with previous root canal treatment, and a great variety of anaerobic microorganisms has been observed in these infections. The...     

Exploring isoxazoles and pyrrolidinones decorated with the 4,6‐dimethoxy‐1,3,5‐triazine unit as human farnesyltransferase inhibitors

Unprecedented triazinyl‐isoxazoles were afforded via an effective cycloaddition reaction between nitrile oxides and the scarcely described 2‐ethynyl‐4,6‐dimethoxy‐1,3,5‐triazine as dipolarophile. The biological evaluation of the newly synthesized compounds showed that the inhibition of human farnesyltransferase by zinc complexation could be improved with triazine‐isoxazole moieties. The replacement of the isoxazole unit by a pyrrolidin‐2‐one was detrimental to the inhibitory activity while the pyrrolidin‐2‐thione derivatives conserved the biological potential. The potential of selected compounds to disrupt protein farnesylation in Chinese hamster ovary (CHO) cells transfected with pEGFP‐CAAX was also evaluated.     

Assessment of bronchial obstruction and its reversibility by shape indexes of the flow‐volume loop in asthmatic children

Asthma assessment by spirometry is challenging in children as forced expiratory volume in 1 s (FEV1) is frequently normal at baseline. Bronchodilator (BD) reversibility testing may reinforce asthma diagnosis but FEV1 sensitivity in children is controversial. Ventilation inhomogeneity, an early sign of airway obstruction, is described by the upward concavity of the descending limb of the forced expiratory flow‐volume loop (FVL), not detected by FEV1. The aim was to test the sensitivity and specificity of FVL shape indexes as β‐angle and forced expiratory flow at 50% of the forced vital capacity (FEF50)/peak expiratory flow (PEF) ratio, to identify asthmatics from healthy children in comparison to “usual” spirometric parameters. Seventy‐two school‐aged asthmatic children and 29 controls were prospectively included. Children performed forced spirometry at baseline and after BD inhalation. Parameters were expressed at baseline as z‐scores and BD reversibility as percentage of change reported to baseline value (Δ%). Receiver operating characteristic curves were generated and sensitivity and specificity at respective thresholds reported. Asthmatics presented significantly smaller zβ‐angle, zFEF50/PEF and zFEV1 (p ≤ .04) and higher BD reversibility, significant for Δ%FEF50/PEF (p = .02) with no difference for Δ%FEV1. zβ‐angle and zFEF50/PEF exhibited better sensitivity (0.58, respectively 0.60) than zFEV1 (0.50), and similar specificity (0.72). Δ%β‐angle showed higher sensitivity compared to Δ%FEV1 (0.72 vs. 0.42), but low specificity (0.52 vs. 0.86). Quantitative and qualitative assessment of FVL by adding shape indexes to spirometry interpretation may improve the ability to detect an airway obstruction, FEV1 reflecting more proximal while shape indexes peripheral bronchial obstruction.