Design of organic molecules with large two-photon absorption cross sections

A strategy for the design of molecules with large two-photon absorption cross sections, delta, was developed, on the basis of the concept that symmetric charge transfer, from the ends of a conjugated system to the middle, or vice versa, upon excitation is correlated to enhanced values of delta. Synthesized bis(styryl)benzene derivatives with donor-pi-donor, donor-acceptor-donor, and acceptor-donor-acceptor structural motifs exhibit exceptionally large values of delta, up to about 400 times that of trans-stilbene. Quantum chemical calculations performed on these molecules indicate that substantial symmetric charge redistribution occurs upon excitation and provide delta values in good agreement with experimental values. The combination of large delta and high fluorescence quantum yield or triplet yield exhibited by molecules developed here offers potential for unprecedented brightness in two-photon fluorescent imaging or enhanced photosensitivity in two-photon sensitization, respectively.     

Engineered deltaguaB-A deltavirG Shigella flexneri 2a strain CVD 1205: construction, safety, immunogenicity, and potential efficacy as a mucosal vaccine

Shigella flexneri 2a strain CVD 1204, which was constructed by introducing a specific, in-frame deletion mutation in the guaB-A operon, was compared with deltaaroA strain CVD 1201. CVD 1204 was less invasive for HeLa cells than CVD 1201, whereas following invasion, the abilities of the two mutants to proliferate intracellularly were similarly impaired. The reduction in invasiveness was independent of the guanine auxotrophic phenotype and fully recovered when the chromosomal deletion mutation in CVD 1204 was repaired. Following inoculation of the conjunctival sac of guinea pigs (Serény test) at high doses (10(9) CFU per eye), both strains evoked minimal, short- lived conjunctival inflammation, which was significantly milder with strain CVD 1204. Double mutant deltaguaB-A deltavirG (also called icsA) strain CVD 1205 induced, after a single intranasal dose, high mucosal immunoglobulin A antilipopolysaccharide titers, which were significantly boosted further following a second dose of vaccine given 14 days later. Upon Serény test challenge with wild-type S. flexneri 2a, CVD 1205-vaccinated animals were significantly protected against keratoconjunctivitis (zero of eight vaccinees versus five of seven controls, P = 0.03; vaccine efficacy, 100%). CVD 1205 is an attractive candidate for human clinical trials.     

Increased urinary catecholamines in a hypertensive child with renal artery stenosis

We report a hypertensive child with renal artery stenosis who exhibited increased urinary excretion of norepinephrine (NE) and normetanephrine (NMN), while vanillylmandelic acid (VMA) excretion was within the normal range. The NMN values prompted us to investigate the patient for pheochromocytoma; for this purpose, NE was determined by plasma catecholamine assays in venous samples obtained by catheterization. The moderately increased NE levels could not be localized to any particular sampling site. Arteriography demonstrated right renal artery abnormalities. Following right nephrectomy with preservation of the right adrenal gland, arterial blood pressure returned to normal. The cause of increased NMN excretion without a concomitant rise in VMA during hypertension is discussed.     

Partial cervicosternotomy: a useful anterior surgical approach to the cervicothoracic junction

12 healthy volunteers on a controlled aluminium (Al) diet each consumed a tea infusion (500 ml/70 kg body weight), with either milk or lemon juice as additives, or mineral water, following a three-way crossover design. The concentrations of Al were determined in the diet, mineral water and tea infusions, and in plasma samples collected before and up to 24 hr after consumption of tea or water, using graphite-furnace atomic absorption spectrophotometry or inductively coupled plasma emission spectrometry. Consumption of up to 1.60 mg Al from tea with milk or lemon juice did not increase plasma Al levels compared with consumption of approximately 0.001 mg Al from mineral water. The results suggest that, in the short-term, drinking tea does not contribute significantly to the total body burden of Al.     

Home nebuliser use in children with asthma in two Scottish Health Board Areas

OBJECTIVE: To audit the use of home nebulisers in children with asthma. DESIGN: Postal questionnaire. SETTING: Two Health Board Areas in Central Scotland--one large industrialised city, one mixed urban and rural. SUBJECTS: 297 children with asthma. MEASURES EVALUATED: Initial supply and technical support for the compressor. EDUCATION: Pattern of drug usage. SYMPTOM CONTROL: Monitoring and treatment of acute attacks. RESULTS: The full burden of the home nebulised therapy is not being met by the NHS. Supply and servicing arrangements for home nebuliser therapy were poorly organised. Chronic asthma symptoms did not appear to be optimally controlled on present medication, with 61% reporting sleep disturbance in the previous three months. About 20% of parents admitted that they would give nebulised bronchodilator therapy more frequently than the recommended 3 to 4 hourly. CONCLUSION: Re-organisation of resources and arrangements could improve the service and bring it in line with recognised standards of care.     

Anti-Müllerian hormone: estimation of molecular weight by gel filtration

Incubation medium of calf fetal testes was submitted to gel filtration on Sephades G 200 and Bio-Gel A-5 M, IN ORDER TO DETERMINE THE MOLECULAR WEIGHT OF THE ANTIMULLERIAN HORmone (A.M.H.) RESPONSIBLE FOR THE REGRESSION OF MULLERIAN DUCTS IN MALE FETUSES. Results from both series of experiments indicate a molecular weight in the range between 200,000 and 295,000 daltons, even in the presence of high concentration of a reducing agent.