Tree-in-Bud Opacities: Not only tuberculosis

We report a clinical case of mentally challenged young gentleman who was repeatedly hospitalized for respiratory symptoms. Contrast-enhanced CT (computed tomography) thorax revealed tree-in-bud (TIB) opacities. Provisional diagnosis of pulmonary tuberculosis was made and was referred to the respiratory team. However, after listening to patient's voice and reviewing the images on CT thorax, the diagnosis was confirmed as aspiration bronchiolitis.

Fiber-integrated 780 nm source for visible parametric generation

We report the development of a fully fiber-integrated pulsed master oscillator power fibre amplifier (MOPFA) source at 780 nm, producing 3.5 W of average power with 410 ps pulses at a repetition rate of 50 MHz. The source consists of an intensity modulated 1560 nm laser diode amplified in an erbium fiber amplifier chain, followed by a fiber coupled periodically poled lithium niobate crystal module for frequency doubling. The source is then used for generating visible light through four-wave mixing in a length of highly nonlinear photonic crystal fiber: 105 mW at 668 nm and 95 mW at 662 nm are obtained, with pump to anti-Stokes conversion slope efficiencies exceeding 6% in both cases.

Effect of internal recycle rate on the high-strength nitrogen wastewater treatment in the combined UBF/MBR system

An anaerobic/aerobic system combining an anaerobic upflow-sludge bed filter (UBF) and an aerobic membrane bioreactor (MBR) was operated to enhance organic and nitrogen removal efficiency. The internal recycle rate, which is one of the most important operation factors that affects overall removal efficiency, was varied from 100% to 300% of the influent flow. Under these conditions, the overall removal efficiencies of organic and nitrogen and characteristics of membrane fouling in the combined system treating the synthetic wastewater including high concentration of organics and nutrients were studied. As a result, nitrogen removal efficiency was increased to 67% when the internal recycle rate was 300% of influent flow rate. As the internal recycle ratio increased from 100% to 200%, protein content decreased by 17% and carbohydrate content increased by 12%. However, there was no remarkable difference in total extracellular polymeric substances (EPS) content. At the high recycle rate of 300%, the surface charge of sludge was decreased while hydrophobicity (specific ultraviolet absorbance, SUVA) was increased. The differences in SUVA and surface charge were 11% and 1%, respectively. It is concluded that SUVA and EPS composition were important parameters affecting membrane fouling in the combined system.

Experience with portfolio-based learning in family medicine for master of medicine degree

BACKGROUND

The Private Practitioners Stream (PPS) of the Family Medicine Traineeship Programme for the Master of Medicine (Family Medicine) (MMed (FM)) was started in 1995. The portfolio-based learning approach was used as the staple learning method in the tutorial system. Due to the autonomy given to Family Medicine trainees in choosing the topics for the portfolio-based presentations, the completeness of coverage of the Family Medicine training syllabus is a research question.

AIM

To study if portfolio-based presentations in a tutorial system covered the broad based Family Medicine training syllabus.

METHOD

Data in the one-page portfolio-based records developed were used to categorise the presentations according to the topics in the Family Medicine Modular Course.

RESULTS

In the three-year period since the introduction of the PPS, 83 tutorials were conducted in which 87 portfolio-based presentations were made. Thirteen (15%) were in the Whole Person Medicine category, 70 (80%) in the Disease Management category and 4 (5%) in the Practice Management category.

CONCLUSION

The portfolio-based learning is recognised as useful in continuing medical education because of the autonomy it gives to the adult learner. In our three years' experience, the one-page portfolio-based record developed was effective as the staple learning tool to cover the broad range of topics required in the defined syllabus of training and to meet the focus of the MMed(FM) examination.

The use of 3-methoxymethyl-16 beta, 17 beta-epiestriol-O-cyclic sulfone as the precursor in the synthesis of F-18 16 alpha-fluoroestradiol

We have prepared 3-methoxymethyl-16 beta, 17 beta-epiestriol-O-cyclic sulfone (1c) and used it as a substrate for the production of F-18 16 alpha-fluoroestradiol, via nucleophilic fluorination with fluoride ion. The compound is straightforward to make from the commercially available epiestriol and is a stable crystalline compound that can be stored for at least a year at room temperature. Reaction with fluorine-18 fluoride provides excellent yields; typically > 90% incorporation of the fluoride is achieved. Partial purification of the labeled product may be accomplished at this stage. Hydrolysis of the methoxymethyl protecting group and ring-opened sulfate occurs rapidly in ethanolic acid solution. In the presence of water the hydrolysis requires more vigorous conditions and additional time but still proceeds to completion. Labeled fluoroestradiol is isolated at the end of a 1-2 h synthesis, depending on the hydrolysis method of 30-45% chemical (decay corrected) yield with respect to fluoride, with a specific activity > 1 Ci per micromole.

An efficient radiosynthesis of [18F]fluoromisonidazole

An efficient preparation of the hypoxic cell tracer [18F]3-fluoro-1-(2'-nitro-1'-imidazolyl)-2-propanol ([18F]fluoromisonidazole) is reported. This radiopharmaceutical is of interest to probe hypoxic tissue in infarcts and tumors. One-step radiolabeling and rapid protection group removal provided 55-80% yield in 50 min. The process is similar to common fluorine labeling procedures, simplifying the procedure for most laboratories, and offers an improvement over more difficult previous methods. The labeling precursor was prepared in five steps from readily available materials in a straightforward reaction scheme.

Synthesis and in vitro receptor binding studies of fluorotamoxifen analogues

We describe the synthesis of new fluorotamoxifen analogues with the fluorine atom positioned on the end of the aliphatic chain of tamoxifen. The binding of fluorotamoxifens to cytosol estrogen receptors of rat uteri was determined with [3H]estradiol (5 nM). The fluorotamoxifens had similar or superior binding affinities compared with tamoxifen. The IC50 value was as follows: tamoxifen, 5 x 10(-7) M; fluorotamoxifen (VII), 5 x 10(-7) M; N,N-diethylfluorotamoxifen (IV)-cis, 1 x 10(-6) M, and trans, 2 x 10(-7) M; and (cis) fluoromethyl-N,N-diethyltamoxifen (VI) 1 x 10(-7) M. Therefore, the fluorinated tamoxifens have potential use in imaging estrogen receptors by PET.

Relative potency of lambdacyhalothrin and cypermethrin applied as thermal fogs for the control of houseflies (Musca domestica) and mosquitos (Aedes aegypti)

Two highly active synthetic pyrethroid insecticides, lambdacyhalothrin and cypermethrin, were evaluated as thermal fogs against houseflies (Musca domestica Linnaeus) and mosquitos (Aedes aegypti Linnaeus). Lambdacyhalothrin (OMS 3021) showed an average of 2.5 times more knockdown activity and over 5 times more adulticidal activity than cypermethrin against Musca domestica and Aedes aegypti. These results demonstrate that lambdacyhalothrin is highly effective at very low rates as a thermal fog against Ae. aegypti and M. domestica. Commercially available formulations of 2.5% and 5% lambdacyhalothrin can be diluted either with water for ULV cold aerosol space-spraying or with diesel/kerosene for thermal fogging at recommended application rates of 0.5-1 g ai/ha for mosquito control and 2 g ai/ha for housefly control. Due to the very low rates of application, formulated products of lambdacyhalothrin are unlikely to present any acute hazards in normal use. The low dosages required to bring about rapid control of houseflies and mosquitos make this new pyrethroid insecticide particularly cost-effective. Coupled with its good residual activity (Jutsum et al, 1984), lambdacyhalothrin can be adopted as a powerful tool in integrated pest management program for the control of medically important pests and vectors.