The production, purification and crystallization of a pocilloporin pigment from a reef-forming coral

Reef-building corals contain fluorescent pigments termed pocilloporins that function by regulating the light environment of coral and acting as a photoprotectant in excessive sunlight. These pocilloporins are related to the monomeric green fluorescent protein and the tetrameric DsRed fluorescent proteins, which have widespread use as biotechnological tools. An intensely blue-coloured pocilloporin, termed Rtms5, was expressed in Escherichia coli, purified and crystallized. Rtms5 was shown to be tetrameric, with deep blue crystals that diffract to 2.2 Angstrom resolution and belong to space group I4(1)22. The colour of this pocilloporin was observed to be sensitive to pH and a yellow (pH 3.5) and a red form (pH 4.5) of Rtms5 were also crystallized. These crystals belong to space group P4(2)22 and diffract to 2.4 Angstrom resolution or better.

A cluster of tuberculosis associated with use of a marijuana water pipe

SETTING: New cases of pulmonary tuberculosis (TB) were noted in a cluster of young Caucasian males, an unusual ethnic group for this disease in Queensland, Australia. It was noted that marijuana water pipe ('bong') smoking was common amongst cases and contacts. OBJECTIVE: To report this cluster of TB and to investigate whether shared use of a marijuana water pipe was associated with transmission of TB. DESIGN: All contacts were identified and screened according to standard protocols. Cases were asked to list contacts with whom they had shared a marijuana water pipe. RESULTS: Five cases of open pulmonary TB were identified clinically and on sputum culture, and all isolates of Mycobacterium tuberculosis were identical on typing. Of 149 contacts identified, 114 (77%) completed screening, and 57 (50%) had significant tuberculin skin test (TST) reactions on follow-up. Of 45 contacts who had shared a marijuana water pipe with a case, 29 (64%) had a significant TST reaction. CONCLUSION: Sharing a marijuana water pipe with a case of pulmonary TB was associated with transmission of TB (OR 2.22, 95% CI 0.96-5.17), although the most important risk factor for acquiring TB infection in this cluster was close household contact with a case (OR 4.91, 95% CI 1.13-20.70).

Effects of chronic exposure to low-level cadmium on renal tubular function and CYP2A6-mediated coumarin metabolism in healthy human subjects

Relationships between cadmium (Cd) body burden, kidney function and coumarin metabolism were investigated using two groups of 197 and 200 healthy Thais with men and women in nearly equal numbers. A mean age of one group was 30.5 years and it was 39.3 years for the other group. Of 397, 20 subjects (5%) excreted urine Cd between 1.4 mug/g and 3.8 mug/g creatinine and these subjects faced 10-15% increase in the probability of having abnormal urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG-uria). The prevalence of NAG-uria varied with Cd body burden in a dose-dependent manner (chi(2) = 22, P < 0.008). Also NAG-nuria was one of the three kidney effect markers tested that showed the greatest strength of correlation with urine Cd in both men and women (r = 0.48 P < 0.001). In addition, urine Cd excretion of men and women showed a positive correlation (r = 0.46 to 0.54. P < 0.001) with urine 7-hydroxycoumarin (7-OHC) excretion which was used as a marker of liver cytochrome P450 2A6 (CYP2A6) enzyme activity. Urinary CA excretion accounted for 25% of the total variation in urine 7-OHC excretion (P < 0.001). These data suggest that Cd may increase the expression of CYP2A6 in liver, resulting in enhanced coumarin metabolism in subjects with high Cd body burden. (C) 2003 Elsevier Ireland Ltd. All rights reserved.

A total electron content space weather study of the Nighttime Weddell Sea Anomaly of 1996/97 southern summer with TOPEX/Poseidon radar altimetry

This paper reports on a total electron content space weather study of the nighttime Weddell Sea Anomaly, overlooked by previously published TOPEX/Poseidon climate studies, and of the nighttime ionosphere during the 1996/1997 southern summer. To ascertain the morphology of spatial TEC distribution over the oceans in terms of hourly, geomagnetic, longitudinal and summer-winter variations, the TOPEX TEC, magnetic, and published neutral wind velocity data are utilized. To understand the underlying physical processes, the TEC results are combined with inclination and declination data plus global magnetic field-line maps. To investigate spatial and temporal TEC variations, geographic/magnetic latitudes and local times are computed. As results show, the nighttime Weddell Sea Anomaly is a large (∼1,600(°)2; ∼22 million km2 estimated for a steady ionosphere) space weather feature. Extending between 200°E and 300°E (geographic), it is an ionization enhancement peaking at 50°S–60°S/250°E–270°E and continuing beyond 66°S. It develops where the spacing between the magnetic field lines is wide/medium, easterly declination is large-medium (20°–50°), and inclination is optimum (∼55°S). Its development and hourly variations are closely correlated with wind speed variations. There is a noticeable (∼43%) reduction in its average area during the high magnetic activity period investigated. Southern summer nighttime TECs follow closely the variations of declination and field-line configuration and therefore introduce a longitudinal division of four (Indian, western/eastern Pacific, Atlantic). Northern winter nighttime TECs measured over a limited area are rather uniform longitudinally because of the small declination variation. TOPEX maps depict the expected strong asymmetry in TEC distribution about the magnetic dip equator.