Biotransformation of linear alkylbenzene sulfonate (LAS) by Phanerochaete chrysosporium: oxidation of alkyl side-chain.

The white rot fungus Phanerochaete chrysosporium, which generally mineralizes substituted aromatics to CO2, transformed linear alkylbenzene sulfonate (LAS) surfactants mainly at their alkyl side chain. Degradation of LAS was evidenced by a zone of clearing on LAS-containing agar plates and colorimetric analysis of liquid cultures. Disappearance of LAS was virtually complete within 10 days in low nitrogen (2.4 mM N), high nitrogen (24 mM N) and malt extract (ME) liquid media. After 5 days of incubation in ME medium, transformation of LAS was complete at concentrations < or = 4 mg l(-1), but decreased at higher concentrations. The LAS degradation was not dependent on lignin peroxidases (LiPs) and manganese-dependent peroxidases (MnPs). Mineralization of 14C-ring-LAS to 14CO2 by P. chrysosporium was < 1% regardless of the culture conditions used. Thin layer chromatography and mass spectral analyses indicated that P. chrysosporium transformed LAS to sulfophenyl carboxylates (SPCs) through oxidative shortening of the alkyl side-chains. While LAS disappearance in the cultures was not dependent on LiPs and MnPs, transformation of the parent LAS moieties to SPCs was more extensive in low N medium that favors expression of these enzymes. The SPCs produced in LN cultures were shorter in chain- length than those produced in ME cultures. Also there was a notable shift in the relative abundance of odd and even chain length metabolites compared to the starting LAS particularly in the low N cultures suggesting the possible involvement of processes other than or in addition to beta-oxidation in the chain-shortening process.

Helping Wisconsin women quit smoking: a successful collaboration.

The cost of treatments for tobacco dependence frequently presents a financial barrier to their use. To overcome such barriers, the Wisconsin Women's Health Foundation, the Wisconsin Bureau of Public Health, the McNeil Consumer Healthcare, and the University of Wisconsin Center for Tobacco Research and Intervention collaborated in an initiative to distribute nicotine patches to Wisconsin women at no cost. As a result of this collaborative effort, approximately 19,000 women received a 6-week course of Nicotrol Patches. To evaluate the effectiveness of this initiative, a sample of 500 recipients were contacted and surveyed by telephone 6 months after receiving their patches. Approximately 22% of these women reported total abstinence at 6 months, and another 77% reported they had reduced their smoking. At follow-up, women who had successfully quit rated their health status significantly better than women who were still smoking. More than 99% of respondents recommended that the program be repeated. Extrapolating the observed abstinence rate to the 19,000 patch recipients, an estimated 4000 Wisconsin women successfully quit smoking as a result of this program.

Localization of the binding region of high mobility group protein 2 to cisplatin-damaged DNA.

Cisplatin (CDDP) is an effective cancer chemotherapeutic drug used in the treatment of several human malignancies. The effectiveness of cisplatin therapy is limited by intrinsic resistance of tumors to this drug as well as the development of secondary tumors, which are also drug resistant. A potential mechanism influencing the sensitivity of cells to CDDP may result from the interaction of specific proteins with CDDP-damaged DNA (CDDP-DNA). In an earlier report, we demonstrated that high mobility group (HMG) proteins 1 and 2 bind with high affinity to CDDP-DNA. In the present study partial proteolytic digestion was used to localize the binding region of HMG2. A proteolytic fragment of approximately 20 kDa, containing the amino-terminal region of the protein, maintains the ability to bind with high affinity to CDDP-DNA, while an amino-terminal fragment of 14 kDa binds with slightly reduced affinity. In contrast, a peptide fragment lacking 51 NH2-terminal amino acids from HMG2 has greatly reduced affinity for damaged DNA. Recombinant peptide fragments containing HMG box 1 or HMG box 2 bind weakly to damaged DNA, while a recombinant fragment containing HMG boxes 1 and 2 binds with high affinity. Hence, our results indicate that the amino-terminal region of HMG2 contains the damaged DNA binding recognition site and that both HMG boxes 1 and 2, present in the parental molecule, are required for high affinity binding of this protein to CDDP-DNA.

The application of normal phase liquid chromatography/mass spectrometry by using coaxial continuous flow fast atom bombardment.

This article describes the interfacing of a normal phase fused silica capillary high performance liquid chromatography system to a magnetic sector mass spectrometer by using continuous flow fast atom bombardment (CFFAB). While the performance of CFFAB using reversed phase techniques is well understood, there is very little if any documentation on interfacing nonaqueous normal phase systems with CFFAB. This article describes the use of packed fused silica capillary liquid chromatography columns and the corresponding normal phase solvent systems. The experimental parameters required with nonaqueous solvent systems differ significantly from those of aqueous solvent systems. Ditallowdimethylammonium chloride (DTDMAC), a cationic surfactant commonly used as the active ingredient in fabric softener products, was chosen as a model compound to demonstrate the technique. DTDMAC was identified in a commercially available fabric softener product by using on-line normal phase liquid chromatography/mass spectrometry with accurate mass and tandem mass spectrometry.

Effect of hypoxic exercise on atrial natriuretic factor and aldosterone regulation.

To evaluate the possible physiologic role of atrial natriuretic factor (ANF) in the observed dissociation of aldosterone secretion from the renin-angiotensin system during hypoxic exercise, 12 untrained men, ages 18 to 24, were studied on two separate days for 30 min during hypoxic (16% O2) and normoxic (room air) exercise on a bicycle ergometer. Workloads were adjusted to produce individual heart rates that remained within 70 to 75% of their previously measured maximum. Hemoglobin saturation decreased during hypoxia from 98 +/- 0.1% to 90 +/- 0.4% (P less than .01). Plasma aldosterone levels increased significantly (P less than .01) under both breathing conditions, yet were on average 36% lower during hypoxia than during normoxia (P less than .001). Plasma ANF levels increased during exercise under both conditions (P less than .01), yet levels were 45% greater during hypoxia than during normoxia (P less than .001). Plasma renin activity, adrenocorticotropic hormone, cortisol, potassium, and systolic blood pressure increased during exercise on both study days (P less than .01, compared to basal level), and showed no difference between normoxic and hypoxic conditions. Plasma pH was slightly higher during hypoxic exercise (P less than .05, compared to normoxia). We conclude that acute hypoxemia is a potent enhancing stimulus for ANF release during dynamic exercise and that ANF is probably a contributing factor in the dissociation of aldosterone secretion from the renin-angiotensin system under these conditions.

Effect of hypoxia on atrial natriuretic factor and aldosterone regulation in humans.

To evaluate the possible physiological role of atrial natriuretic factor (ANF) on the observed dissociation of aldosterone from the renin-angiotensin system during acute hypoxia, 7 men, ages 18-27 yr, were studied on two separate days for 1 h under hypoxic (12% O2) and normoxic (room air) conditions. Subjects were on a low-salt diet (urinary sodium 67 +/- 13 meq/24 h) and suppressed with dexamethasone. Hemoglobin saturation decreased during hypoxemia to 68 +/- 1% (P less than 0.01), whereas heart rate increased from 65 +/- 3 to 89 +/- 5 beats/min (P less than 0.01). Plasma aldosterone levels decreased 43% from basal during hypoxemia (P less than 0.01), whereas ANF levels increased by 50% (P less than 0.05). Levels of both were unchanged during normoxemia. Plasma renin activity, angiotensin II, blood pressure, and pH did not change under either condition, and plasma cortisol levels were totally suppressed. These results indicate that acute hypoxemia is a potent stimulus for ANF release and that ANF is probably a major factor responsible for the dissociation of aldosterone from the renin-angiotensin system under these conditions.

An anatomical study of human otocephaly.

This study describes the gross anatomic variations observed in a 32-week male fetus diagnosed as having otocephaly. Special attention was given to the muscular, peripheral nervous, and vascular systems of the entire body. External features included approximation of the ears on the front of the neck, underdevelopment of the lower jaw, and a small oral cavity. The mandible, maxillae, and zygomatic bones were smaller than normal and appeared shifted in a ventrocaudal direction. The middle ear ossicles were fused and abnormally positioned. The tongue was positioned abnormally and malformed. The muscles of mastication were fused in the midline and formed the floor of the oral cavity. The variations were similar to the spectrum of abnormalities reported in two cases in the literature. Because of this finding, it is possible that the causative events leading to these deviations were similar in the three cases. Possible mechanisms are considered which could lead to the observed malformations seen in these cases. There were also several muscle and nerve anomalies outside of the head region.