Multiple splice variants of the human calcium-independent phospholipase A2 and their effect on enzyme activity.

Recently, the cloning of a novel Ca2+-independent phospholipase A2 (iPLA2) from Chinese hamster ovary cells as well as from mouse and rat sources containing a C-terminal lipase motif and eight N-terminal ankyrin repeats has been described. In this report we describe the cloning of the human iPLA2 cDNA and its expression in B-cells and show that the iPLA2 gene undergoes extensive alternative splicing generating multiple isoforms that contribute to a novel mechanism to control iPLA2 activity. The full-length cDNA clone encodes a 806-amino acid protein with a calculated molecular mass of 88 kDa. The protein contains a lipase motif, GXSXG, and ankyrin repeats, as described for the hamster and rodent forms of the enzyme but has an additional 54-amino acid proline-rich insertion in the last of the eight ankyrin repeats (residues 395-449). Furthermore, at least three additional isoforms most likely due to alternative splicing were identified. One that is present as a partial cDNA in the expressed sequence tag data base is similar to iPLA2 but terminates just after the lipase active site, and two other isoforms contain only the iPLA2 ankyrin repeat sequence (ankyrin-iPLA2-1 and -2). Ankyrin repeats are involved in protein-protein interactions and because the purified iPLA2 enzyme exists as a multimeric complex of 270-350 kDa, the expression of just the ankyrin-iPLA2 sequence suggested that these may also interact with the iPLA2 oligomeric complexes and perhaps modulate PLA2 activity. Transfection of the human iPLA2 cDNA into COS cells resulted in a substantial increase in calcium-independent PLA2 activity in cell lysate. No activity above background was observed following ankyrin-iPLA2-1 cDNA transfection. However, co-transfection of the ankyrin-iPLA2-1 and the iPLA2 cDNAs resulted in a 2-fold reduction in activity compared with iPLA2 alone. A similar co-transfection of ankyrin-iPLA2-1 cDNA with the cPLA2 cDNA had no effect on PLA2 activity. These results suggest that the ankyrin-iPLA2 sequence can function as a negative regulator of iPLA2 activity and that the alternative splicing of the iPLA2 gene can have a direct effect on the attenuation of enzyme activity.

High-level expression of active human cyclooxygenase-2 in insect cells.

Active human cyclooxygenase-2 (Cox-2) was expressed at high levels in insect cells using a recombinant baculovirus. The specific activity of Cox-2 in the microsomes of infected cells was 0.51 mumol O2/min/mg and was comparable to that obtained for partially purified Cox-2 from ovine placenta (0.55 mumol O2/min/mg). The Cox-2 enzyme expressed in insect cells was glycosylated to varying extents and most of the cyclooxygenase activity was in the high-speed microsomal pellet. The insect-cell-expressed enzyme also showed characteristic 15-hydroxyeicosa-tetraenoic acid production after aspirin treatment and had typical inhibition profiles with a number of known nonsteroidal antiinflammatory drugs.

Cloning and expression of rat prostaglandin endoperoxide synthase (cyclooxygenase)-2 cDNA.

Rat prostaglandin endoperoxidase synthase-2 (PGHS-2) cDNA was cloned from rat calvarial osteoblasts total RNA by RT-PCR. The primary sequence of rat PGHS-2 had 98% and 92% identity to the mouse and human enzymes, respectively. Transfection of the rat PGHS-2 cDNA into COS 7 cells, followed by the addition of 20 microM arachidonic acid, resulted in a dramatic increase in PGE2 released from these cells. The amount of PGE2 produced was comparable to that obtained from cells similarly transfected with human PGHS-1 cDNA. In the rat paw carrageenin-oedema inflammatory model, the injected paw had elevated levels of PGHS-2 mRNA compared to the control paw. In a rat pyrexia model, injection of the pyrogen lipopolysaccharide, resulted in elevated levels of PGHS-2 mRNA in the brain. These results suggest that PGHS-2 expression plays a role both in inflammation and fever.

The Beech Hill Hospital/Outward Bound Adolescent Chemical Dependency Treatment Program.

Ninety-one adolescents (74 males and 17 females, mean age = 16.5, range = 14-20) admitted to an in-patient treatment facility with a substance use disorder were followed over a 1-year period post-treatment. Follow-up phone interviews were conducted with each patient and a parent at 3-month intervals. Minnesota Multiphasic Personality Inventory (MMPI) and Personal Experience Inventory (PEI) data were collected along with detailed psychosocial assessments to determine what factors predicted successful treatment outcomes. At 1-year post-treatment, 47% reported complete abstinence from alcohol and other drugs. Survival analyses indicated that participation in a self-help program such as Alcoholics Anonymous (AA) and severity of drug use and psychopathology were associated with relapse risk. Patients with severe psychopathology and drug use scores who were not attending AA were 4.5 times more likely to relapse than patients with low scores who attended AA.

Altered states of consciousness therapy. A missing component in alcohol and drug rehabilitation treatment.

Attaining altered states of consciousness is described as a basic human motive. The substance dependent population is distinguished from other populations because they pursue these states destructively by inappropriate use of alcohol and drugs. Despite a body of literature supporting the benefits of altered states of consciousness, alcohol and drug rehabilitation treatment programs fail to address this motive because of social disapproval, means-end confusion, and inadequate staff training. The authors maintain that Alcoholics Anonymous directs its members toward an altered state of consciousness called a spiritual awakening, which replaces the self-destructive pursuit of substance induced "highs." Failure to address patients' need for alternative methods of achieving altered states of consciousness is presented as part of the reason for relapse. An Altered States of Consciousness Therapy (ASCT) program is described that can be used to teach patients to consciously manipulate affect and cognition to achieve a new consciousness.

Determination of methylene chloride, ethylene dichloride, and trichloroethylene as solvent residues in spice oleoresins, using vacuum distillation and electron capture gas chromatography.

A quantitative gas chromatographic (GC) method is described for the determination of residual methylene chloride, ethylene dichloride, and trichloroethylene in spice oleoresins. The proposed method involves vacuum distillation in a closed system with toluene as a carrier solvent. Quantitation by electron capture GC on Porapak Q is facilitated by water extraction and by the addition of trans-1,2-dichloroethylene as an internal standard. Recoveries from oleoresins spiked at 30, 15, and 6 ppm ranged from 93 to 102%. To assess the possibility of interference from spice volatiles, the procedure was applied to 17 different spice oleoresins from 3 different manufacturers. No interferences were found, but methylene chloride levels up to 83 ppm and ethylene dichloride levels up to 23 ppm were detected. Trichloroethylene was not detected in any of the oleoresins.