Patients' experiences of an open access follow up arrangement in managing inflammatory bowel disease

BACKGROUND

Improving access is a key policy issue in improving quality of care and extending patient choice and participation. People's experience of changing from fixed outpatient appointments to more flexible direct access arrangements for chronic disease has been underexplored.

OBJECTIVES

To examine patients' views on using an open system of access compared with fixed outpatient appointments as part of a guided self-management intervention for inflammatory bowel disease (IBD).

DESIGN

Embedded qualitative study undertaken alongside a randomised controlled trial. Semi-structured interviews were undertaken to obtain an in depth understanding of patients' experience of the change in access arrangements.

PARTICIPANTS

A purposive sample (n = 30) was drawn from the intervention group (n = 700) according to a range of responses to the trial baseline and follow up quantitative measures.

RESULTS

28 interviews were included in the analysis. Compared with the previous system of fixed appointments, preference for the new open access system was based on enhanced personal control in contacting services and the view that it fitted better with everyday routine management and the requirement for urgent medical contact when symptoms fail to respond to medication. Preference for retaining fixed appointments was based on a sense of security from gaining access which did not require the individual to initiate the request for medical help.

CONCLUSIONS

Open access may fit better with patients' self-management of their condition and everyday routines, roles and responsibilities. Ensuring that outpatient organisational arrangements and personnel are responsive to patient initiated requests for appointments is likely to impact on the acceptability of this type of access arrangement. Some people may continue to prefer the fixed appointment system which should be retained if patient choice is to be respected.

Dental caries in HIV-seropositive women

Reports that compare dental caries indices in HIV-seropositive (HIV+) subjects with HIV-seronegative (HIV-) subjects are rare. The objective of this study was to determine if there was an association between HIV infection and dental caries among women enrolled in the Women's Interagency HIV Study. Subjects included 538 HIV+ and 141 HIV- women at baseline and 242 HIV+ and 66 HIV- women at year 5. Caries indices included DMFS and DFS (coronal caries) and DFSrc (root caries). Cross-sectional analysis of coronal caries data revealed a 1.2-fold-higher caries prevalence among HIV+ women compared with HIV- women. Longitudinally, DMFS increased with increasing age and lower average stimulated salivary volume. Root caries results were not significant except for an overall increased DFSrc associated with smoking. Anti-retroviral therapy was not identified as a risk factor for dental caries.

A randomised controlled trial to assess the effectiveness and cost of a patient orientated self management approach to chronic inflammatory bowel disease

OBJECTIVES

We developed a patient centred approach to chronic disease self management by providing information designed to promote patient choice. We then conducted a randomised controlled trial of the approach in inflammatory bowel disease (IBD) to assess whether it could alter clinical outcome and affect health service use.

DESIGN

A multicentre cluster randomised controlled trial.

SETTING

The trial was conducted in the outpatient departments of 19 hospitals with randomisation by treatment centre, 10 control sites, and nine intervention sites. For patients at intervention sites, an individual self management plan was negotiated and written information provided.

PARTICIPANTS

A total of 700 patients with established inflammatory bowel disease were recruited.

MAIN OUTCOME MEASURES

Main outcome measures recorded at one year were: quality of life, health service resource use, and patient satisfaction. Secondary outcomes included measures of enablement-confidence to cope with the condition.

RESULTS

One year following the intervention, self managing patients had made fewer hospital visits (difference -1.04 (95% confidence interval (CI) -1.43 to -0.65); p<0.001) without increase in the number of primary care visits, and quality of life was maintained without evidence of anxiety about the programme. The two groups were similar with respect to satisfaction with consultations. Immediately after the initial consultation, those who had undergone self management training reported greater confidence in being able to cope with their condition (difference 0.90 (95% CI 0.12-1.68); p<0.03).

CONCLUSIONS

Adoption of this approach for the management of chronic disease such as IBD in the NHS and other managed health care organisations would considerably reduce health provision costs and benefit disease control.

Whole body magnetic resonance imaging in the diagnosis of Parsonage Turner syndrome

PURPOSE

To describe magnetic resonance imaging (MRI) findings in patients with suspected Parsonage Turner syndrome and to emphasize the value of an additional whole body MR scan to improve specificity of this diagnosis.

MATERIAL AND METHODS

Three patients with proven Parsonage Turner syndrome referred for conventional MRI of the shoulder girdle and additional whole body turboSTIR MRI were included for study.

RESULTS

In each case, imaging revealed edema in the muscles of the shoulder girdle. Whole body turboSTIR MRI scan confirmed localized unilateral changes in each case improving specificity and confidence in the diagnosis of Parsonage Turner syndrome in each case.

CONCLUSION

Whole body turboSTIR MR imaging is a useful diagnostic tool in the evaluation of patients with suspected Parsonage Turner syndrome. Inclusion of the brain, neck, brachial plexus, and extremity musculature at whole body imaging allows differentiation from polymyositis and elimination of additional causes of shoulder girdle pain and weakness including gross lesions in the brain, neck, and brachial plexus by a single non-invasive study.

A randomised controlled trial to assess the impact of a package comprising a patient-orientated, evidence-based self-help guidebook and patient-centred consultations on disease management and satisfaction in inflammatory bowel disease

OBJECTIVES

To determine if a whole systems approach to self-management improves clinical outcomes and leads to cost-effective use of NHS services.

DESIGN

Nineteen hospitals were randomised to 10 control sites and nine intervention sites. Consultants from intervention sites received training in patient-centred care before recruitment and introduced the intervention to eligible patients. Patients at the control sites were recruited and went on to have an ordinary consultation. Qualitative interviews were undertaken to obtain an in-depth understanding of patients' and consultants' experience of the intervention.

SETTING

Follow-up outpatient clinics at 19 hospitals in the north-west of England.

PARTICIPANTS

Seven hundred patients (297 at intervention sites and 403 at control sites) with established ulcerative colitis or Crohn's disease, aged 16 years and over, and able to write in English.

INTERVENTIONS

Consultants were trained to provide a patient-centred approach to care. Guidebooks on ulcerative colitis and Crohn's disease were developed with patients prior to the study. Patients prepared a written self-management plan and self-referred to services based on a self-evaluation of their need for advice.

MAIN OUTCOME MEASURES

Rates of hospital outpatient consultation, quality of life (QoL) and acceptability to patients. Health service resource use and assessed cost effectiveness using the EQ-5D.

RESULTS

After 1 year, the intervention resulted in fewer hospital visits, without change in the number of primary care visits. Patients felt more able to cope with their condition. The intervention produced no reduction in QoL and did not raise anxiety. The intervention group reported fewer symptom relapses; 74% of patients in the intervention group indicated a preference to continue the system. Qualitative results showed the guidebook was effective but organisational limitations constrained patient-centred aspects of the intervention for some. Cost-effectiveness analyses favoured self-management over standard care.

CONCLUSIONS

Further use of this method in chronic disease management seems likely to improve overall patient satisfaction and reduce health expenditure without evidence of adverse effect on disease control. Further attention needs to be given to self-referral and access arrangements and a re-distribution of control to patients through increased adherence to patient-centred norms on the part of consultants. Future research is recommended to evaluate the operating systems within secondary and primary care that would allow self-managers to self-refer and to keep them informed of new treatments, also to explore models for training health professionals in self-care methods, to study long-term effects of self-management in chronic disease and to transfer this approach to other chronic conditions.

The use of a bacteria detection system to evaluate bacterial contamination in PLT concentrates

BACKGROUND

Random-donor PLTs (RDPs) are functional at 7 days. Nevertheless, since the mid-1980s, concern for bacterial contamination has caused the storage period to be reduced to 5 days. The ability of a bacteria detection system (BDS, Pall) to determine bacterial contamination and permit extension of the PLT shelf life to 7 days was assessed.

STUDY DESIGN AND METHODS

Blood was collected into CP2D and leukoreduced RDPs were prepared. Upon arrival at the hospital, a 2- to 3-mL aliquot was removed from each RDP and introduced into the Pall BDS pouch with a sterile docking device. The pouch was incubated at 37 degrees C for 24 hours and then the oxygen content was measured to determine bacterial contamination. Additionally, the RDPs were pooled and an aliquot was removed for culture with standard manual techniques. CCIs were calculated 1 hour after infusion.

RESULTS

A total of 12,062 individual RDPs were tested. The Pall BDS detected bacteria in 5 units. All of these were positive on repeat sampling. Propionibacterium acnes, coagulase-negative Staphylococcus, and Bacillus species were confirmed by manual technique in 3 units, one could not be identified, and one was negative. Aliquots from PLT pools were positive in 80 of 2201 pools when tested by manual methods. Of these, 79 were false-positives and 1 unit contained coagulase-negative Staphylococcus. The Pall BDS was easy to use and required less than 5 minutes for all manipulations. After 7 days of storage, the PLTs gave an average CCI of 16 x 10(11)+/- 3.39 x 10(11) 1 hour after transfusion (n = 9).

CONCLUSIONS

The Pall BDS permits evaluation of RDPs for bacterial contamination. Culture-negative PLTs were successfully transfused in our institution up to and including 7 days after storage with good CCIs.

Technical note: postgadolinium two-dimensional time-of-flight MR angiography of the foot

OBJECTIVE

The purpose of this study was to determine the ability of postgadolinium time-of-flight (TOF) MR angiography to image the foot of patients compared to conventional TOF MR angiography.

SUBJECTS AND METHODS

Six feet in five patients were included in this prospective study. Standard two-dimensional axial TOF sequences of the lower extremities, followed by three-dimensional (3D) contrast-enhanced moving-table images of the aorta to the foot during the intravenous bolus administration of gadolinium, were obtained in all patients. Two-dimensional axial respiratory-compensated TOF sequences were then obtained over the foot. Axial images and maximum intensity projections (MIP) reconstructions were evaluated by two blinded radiologists and images rated with respect to overall image quality, large-vessel and small-vessel visualization, degree of venous overlap, and extent of vessel stenosis.

RESULTS

The 2D postgadolinium TOF technique resulted in an improvement in all areas of image quality compared with the noncontrast acquisition method, with very good interobserver agreement (kappa 0.67). Postcontrast images provided superior vessel visualization ( p=0.024, Wilcoxon signed rank test), with minimal artifact (84% with none, kappa 1.0), and excellent agreement on grading of dorsalis pedis stenosis (kappa 0.78). Vessel-to-background signal intensity ratio was doubled compared to the standard technique (mean 19.5, SD 6.5 versus 8.8, SD 4.5; p=0.016).

CONCLUSION

Postgadolinium TOF MR angiography of the foot demonstrates significantly improved image quality over noncontrast techniques.

The six week postnatal check: women's choice of service provider

This study describes mothers' choice between General Practitioner (GP) and hospital clinics for the six week postnatal check and elucidates influencing factors for their choice, using structured interviews with mothers within one week of discharge from hospital. Intended uptake of the six week check was high overall. For mother's own check, 203 (45%) planned to attend hospital clinics and 116 (26%) planned to attend the GP, while for the baby's check 115 (26%) planned to attend hospital clinics and 245 (55%) planned to attend the GP. The remainder planned to attend a consultant privately or had been referred to the specialised gynaecological/paediatric clinic. Factors influential for those choosing GPs were: convenience, familiarity and opportunity for discussion. Hospital instructions and the expected quality of examination were important for those choosing the hospital. Some possible misconceptions regarding provision of aspects of postnatal care were uncovered. This study highlights underuse of the GP service for the routine six week check and makes recommendations in relation to this.

Passive transfer of virus-specific antibodies confers protection against reproductive failure induced by a virulent strain of porcine reproductive and respiratory syndrome virus and establishes sterilizing immunity

Immune mechanisms mediating protective immunity against porcine reproductive and respiratory syndrome virus (PRRSV) are not well understood. The PRRSV-specific humoral immune response has been dismissed as being ineffective and perhaps deleterious for the host. The function of PRRSV antibodies in protective immunity against infection with a highly abortifacient strain of this virus was examined by passive transfer experiments in pregnant swine. All of a group of pregnant gilts (n = 6) that received PRRSV immunoglobulin (Ig) from PRRSV-convalescent, hyperimmune animals were fully protected from reproductive failure as judged by 95% viability of offspring at weaning (15 days of age). On the other hand, the totality of animals in a matched control group (n = 6) receiving anti-pseudorabies virus (PRV) Ig exhibited marked reproductive failure with 4% survival at weaning. Besides protecting the pregnant females from clinical reproductive disease, the passive transfer of PRRSV Ig prevented the challenge virus from infecting the dams and precluded its vertical transmission, as evidenced by the complete absence of infectious PRRSV from the tissues of the dams and lack of infection in their offspring. In summary, these results indicate that PRRSV-Igs are capable of conferring protective immunity against PRRSV and furthermore that these Igs can provide sterilizing immunity in vivo.

Study on social responses (encouraging public awareness) to sudden infant death syndrome: evaluation of SIDS prevention campaigns

The sudden infant death syndrome (SIDS) prevention campaign promulgated by the SIDS Family Associations was initiated and directed to medical professionals in 1996 and to mothers in 1997. In mid-1998, the Ministry of Health and Welfare began to support this campaign. In parallel with these moves and with cooperation from the study group of the Ministry of Health and Welfare and the SIDS Family Associations of Japan, a Japanese segment of the International Child Care Practices Survey (ICCPS) was conducted in two phases--from 1996 to 1997 and from 1998 to 1999--to observe the trends in risk factors for SIDS that may exist in the child rearing environment in Japan. Consequently, after the SIDS prevention campaign, the risk factors for SIDS, such as the practice of placing infants in a prone posture, smoking, and formula feeding, were reduced. Correspondingly, it was shown that the incidence of SIDS in Japan and in Kanagawa Prefecture where the survey was carried out considerably decreased (0.42-0.24 per 1000 live births). These data indicate that this prevention campaign has been effective.

Long-term treatment with subcutaneous T-20, a fusion inhibitor, in HIV-infected patients: patient satisfaction and impact on activities of daily living

T-20 is a novel antiretroviral agent that inhibits the fusion of human immunodeficiency virus (HIV) with target cell membranes. It is delivered by self-administered, twice-daily, subcutaneous injections. The impact of this mode of administration on patients' ability to conduct normal activities of daily living (ADL) and comply with a T-20 treatment regimen was assessed as part of a 48-week, phase 2 trial (T20-205). Patients' opinions on the impact of T-20 on ADL, ease of use of T-20, and choice to continue with T-20 were assessed by two questionnaires completed at baseline and week 48 (or study withdrawal). ADL were measured using a Likert-type scale based on established instruments with questions added to assess HIV-specific issues. Seventy previously treated patients received T-20 in combination with an average of five oral antiretroviral agents. Relative to other HIV/AIDS drugs, T-20 had little impact on ADL, with the majority of patients (54%-96%) agreeing (somewhat or strongly) that subcutaneous injections had not limited ADL. Patients found the injections relatively easy to perform with more than 47% of patients stating that each aspect of the injections (ease of injection, storage, reconstitution, and disposal of sharps) were very easy or easy. If medically indicated, 98% of patients stated that they would choose to continue with T-20. The most common reasons for this were the perceived effectiveness of T-20 and lack of side effects. In conclusion, the need to deliver T-20 via twice-daily subcutaneous injections was not considered an important barrier by HIV-positive patients seeking improvement or stabilization of their condition.

Induction of granulocytic differentiation by 2 pathways

The CCAAT enhancer binding protein alpha (C/EBP alpha) transcription factor plays a critical role in granulocytopoiesis. Mice with a disruption of the C/EBP alpha gene demonstrate an early block in granulocytic differentiation, and disruption of C/EBP alpha function is a common theme in many types of human acute myelogenous leukemia, which is characterized by a block in myeloid development. To characterize further the nature of this block, we derived cell lines from the fetal liver of C/EBP alpha-deficient animals. These lines resembled morphologically the immature myeloid blasts observed in C/EBP alpha(-/-) fetal livers and did not express messenger RNA encoding early myeloid genes such as myeloperoxidase. Similarly, granulocytic markers such as Mac-1 and Gr-1 were not expressed; nor were erythroid and lymphoid surface antigens. Introduction of an inducible C/EBP alpha gene into the line revealed that conditional expression of C/EBP alpha induced the C/EBP family members C/EBP beta and C/EBP epsilon and subsequent granulocyte differentiation. Similar results were obtained when C/EBP alpha(-/-) cells were stimulated with the cytokines interleukin-3 and granulocyte-macrophage colony-stimulating factor, but not with all-trans retinoic acid, supporting a model of at least 2 pathways leading to the differentiation of myeloid progenitors to granulocytes and implicating induction of other C/EBP family members in granulopoiesis.

Same patients, same critical events--different systems of care, different outcomes: description of a human factors approach aimed at improving the efficacy and safety of sedation/analgesia care

The practice of sedating pediatric patients undergoing diagnostic and therapeutic procedures represents an ideal model for evaluating systems of health care delivery. We present detailed evidence of how different systems acting on the same patient under similar conditions result in very different outcomes. In contrast to epidemiological methods, our research follows a Human Factors approach of observing a small number of representative cases in great detail to characterize the critical components and processes of ideal sedation care. In this descriptive article we present a framework by which this work domain can be codified and evaluated. We conclude with a demonstration of how a patient simulator can be used to quantify responses to sedation emergencies. These data constitute the basis for innovating novel sedation care systems and strategies that will optimize safety and efficacy.

Three-color flow cytometric assay for the study of the mechanisms of cell-mediated cytotoxicity

Cytotoxic lymphocytes kill tumor or virus-infected target cells utilizing two mechanisms (1) release of lytic granules (containing perforin and granzymes) and (2) Fas ligand (FasL)/Fas or TNF initiated apoptosis. We have examined mechanisms of target cell lysis using a new Flow Cytometric Cytotoxicity Assay (FC Assay). Target cells were labeled with PKH 67 dye. Cell death was estimated by 7-amino-actinomycin (7-AAD) inclusion and annexin V-PE binding. A strong direct correlation has been found between the percentage of dead target cells in the FC Assay and the results of 51Cr release assay when human LAK and CTL were used as a model system. We have shown that both NK and CTL kill tumor cells mostly by granule-mediated mechanisms, as lysis was blocked by a perforin inhibitor Concanamycin A (Folimycin) but was significantly less sensitive to zVAD-FMK caspase inhibition. The FC assay allows accurate measurement of cell-mediated cytotoxicity as individual target cell death is detected directly.

Careers in toxicology in Europe--options and requirements. Report of a workshop organized on behalf of the Individual Members of EUROTOX during the EUROTOX Congress 2000 in London (September 17-20, 2000)

In view of the lack of information regarding careers for toxicologists in Europe, the Individual Members of EUROTOX organised a workshop on careers in toxicology during the EUROTOX Congress 2000 in London. Toxicologists are mainly employed in academia, regulatory agencies, contract research organisations (CROs) and the chemical and pharmaceutical industries. There are also a few governmental institutes involved with toxicological work other than teaching or regulation. Toxicologists can also work as independent consultants, especially for commercial organisations. The requirements for starting a career in any of the above organisations, the need and the advantages and disadvantages of specialisation, and further career prospects are summarised and briefly discussed. The organisations, and also working as an independent toxicology consultant, offer interesting professional work of relevance to modern-day society. There is currently a shortage of toxicologists not only in the traditional field of risk assessment but also especially in new areas, e.g. toxicogenomics. This shortage may be at least in part due to insufficient training opportunities. Further consideration of career opportunities is planned and will be published in due course.

Fibrin sealant reduces the duration and amount of fluid drainage after axillary dissection: a randomized prospective clinical trial

BACKGROUND

Patients who have axillary dissections during lumpectomy or modified radical mastectomy for breast carcinoma accumulate serosanguinous fluid, potentially resulting in a seroma. Currently accepted practice includes insertion of one or more drains for fluid evacuation. This multicenter, randomized, controlled, phase II study was undertaken to evaluate whether a virally inactivated, investigational fibrin sealant is safe and effective when used as a sealing agent to reduce the duration and volume of serosanguinous fluid drainage and to determine the dose response of this effect.

STUDY DESIGN

Patients undergoing lumpectomy or modified radical mastectomy were randomized to treatment with 4, 8, or 16 mL of fibrin sealant or control (no agent) at the axillary dissections site. Patients undergoing modified radical mastectomy also received an additional 4 or 8 mL of fibrin sealant at the skin flap site. Efficacy was evaluated by the number of days required for wound drainage and the volume of fluid drainage compared with control. Safety was confirmed by clinical course, the absence of viral seroconversion, and no major complications attributable to the sealant.

RESULTS

The 4-mL axillary dissection dose of fibrin sealant significantly reduced the duration and quantity of fluid drainage from the axilla following lumpectomy (p < or = 0.05). In the modified radical mastectomy patients, a 16-mL axillary dissection dose combined with an 8-mL skin flap dose was significantly effective in reducing the number of days to drain removal (p < or = 0.05) and fluid drainage (p < or = 0.01). There were no fibrin sealant patient viral seroconversions and no major complications attributable to the sealant. A number of wound infections were noted, although this may represent a center-specific effect.

CONCLUSIONS

Application of fibrin sealant following axillary dissection at the time of lumpectomy or modified radical mastectomy can significantly decrease the duration and quantity of serosanguinous drainage. The viral safety of the product was also supported.

Divalproex sodium in sex offenders with bipolar disorders and comorbid paraphilias: an open retrospective study

BACKGROUND

This study evaluated divalproex response in sex offenders with a bipolar disorder.

METHODS

We reviewed the records of all sex offenders who participated in a residential rehabilitative program who received divalproex for treatment of a bipolar disorder. Patients' mood symptoms and, when present, comorbid paraphilic symptoms, were retrospectively assessed using the CGI severity scale.

RESULTS

Sex offenders displayed significant improvement in manic symptoms with divalproex treatment. However, there was no significant improvement in paraphilic symptoms in the subset of patients admitting to these symptoms.

CONCLUSION

Divalproex may be effective for manic symptoms in sex offenders with a bipolar disorder. However, for bipolar sex offenders with comorbid paraphilias, the drug may not be effective for paraphilic symptoms.

LIMITATIONS

This study was limited by its retrospective, open-label design, lack of systematic means of assessing manic and paraphilic symptoms, and small sample size.

CLINICAL RELEVANCE

Divalproex may be a helpful adjunct in the treatment of the subset of sex offenders who have a bipolar disorder.

An integrative approach for studying the etiology of alcoholism and other addictions

Studies of alcoholism etiology often focus on genetic or psychosocial approaches, but not both. Greater understanding of the etiology of alcohol, tobacco and other addictions will come from integration of these research traditions. A research approach is outlined to test three models for the etiology of addictions--behavioral undercontrol, pharmacologic vulnerability, negative affect regulation--addressing key questions including (i) mediators of genetic effects, (ii) genotype-environment correlation effects, (iii) genotype x environment interaction effects, (iv) the developmental unfolding of genetic and environmental effects, (v) subtyping including identification of distinct trajectories of substance involvement, (vi) identification of individual genes that contribute to risk, and (vii) the consequences of excessive use. By using coordinated research designs, including prospective assessment of adolescent twins and their siblings and parents; of adult substance dependent and control twins and their MZ and DZ cotwins, the spouses of these pairs, and their adolescent offspring; and of regular families; by selecting for gene-mapping approaches sibships screened for extreme concordance or discordance on quantitative indices of substance use; and by using experimental (drug challenge) as well as survey approaches, a number of key questions concerning addiction etiology can be addressed. We discuss complementary strengths and weaknesses of different sampling strategies, as well as methods to implement such an integrated approach illustrated for the study of alcoholism etiology. A coordinated program of twin and family studies will allow a comprehensive dissection of the interplay of genetic and environmental risk-factors in the etiology of alcoholism and other addictions.

The miseries of passive smoking

Passive smoking is defined as an involuntary exposure to a combined but diluted cigarette sidestream smoke (SS, gas and particle phases that are evolved from the smoldering end of a cigarette while the smoker is not puffing) and the exhaled smoke from smokers. SS contains numerous cytotoxic substances such as polycyclic aromatic hydrocarbons (PAHs), aromatic amines, nitrosamines, heavy metals, poisonous gases, pesticide residues, and radioactive elements in quantities much higher than those found from the cigarette mainstream smoke (MS) which is puffed by smokers. Passive smoking is found to be the cause of death from cancers and cardiac disease. Furthermore, it damagingly involves reproductive organs, the nervous system, genetic materials, and is particularly hazardous to mother and child during pregnancy and to those with a history of asthma, chronic infections, induced or earned immune deficiency, or predisposed susceptibility.

Protein docking using continuum electrostatics and geometric fit

The computer program DOT quickly finds low-energy docked structures for two proteins by performing a systematic search over six degrees of freedom. A novel feature of DOT is its energy function, which is the sum of both a Poisson-Boltzmann electrostatic energy and a van der Waals energy, each represented as a grid-based correlation function. DOT evaluates the energy of interaction for many orientations of the moving molecule and maintains separate lists scored by either the electrostatic energy, the van der Waals energy or the composite sum of both. The free energy is obtained by summing the Boltzmann factor over all rotations at each grid point. Three important findings are presented. First, for a wide variety of protein-protein interactions, the composite-energy function is shown to produce larger clusters of correct answers than found by scoring with either van der Waals energy (geometric fit) or electrostatic energy alone. Second, free-energy clusters are demonstrated to be indicators of binding sites. Third, the contributions of electrostatic and attractive van der Waals energies to the total energy term appropriately reflect the nature of the various types of protein-protein interactions studied.

Phosphorylation cascades control the actions of ethanol on cell cAMP signalling

Our studies indicate that, in the presence of particular isoforms of adenylyl cyclase (i.e., type 7 AC), moderately intoxicating concentrations of ethanol will significantly potentiate transmitter-mediated activation of the cAMP signaling cascade. Activation of this signaling cascade may have important implications for the mechanisms by which ethanol produces intoxication, and/or for the mechanisms of neuroadaptation leading to tolerance to, and physical dependence on, ethanol. We initiated a series of studies to investigate the phosphorylation of AC7 by PKC, the role of this phosphorylation in modulating the sensitivity of AC7 to activation by Gsalpha, and the PKC isotype(s) involved in the phosphorylation of AC7. The T7 epitope-tagged AC7 expressed in Sf9 and HEK293 cells was found to be phosphorylated in vitro by the catalytic subunit of PKC. Treatment of AC7-transfected HEK293 cells with phorbol dibutyrate (PDBu) or ethanol increased the phosphorylation of AC7 and its responsiveness to Gsalpha. In human erythroleukemia (HEL) cells, which endogeneously express AC7, ethanol and PDBu increased AC activity stimulated by PGE(1). The potentiation by both PDBu and ethanol was found to be sensitive to the PKC delta-selective inhibitor, rottlerin. The potentiation of AC activity by ethanol in HEL cells was also selectively attenuated by the RACK inhibitory peptide specific for PKC delta, and by expression of the dominant negative, catalytically inactive, form of PKC delta. These data demonstrate that AC7 can be phosphorylated by PKC, leading to an increase in functional activity, and ethanol can potentiate AC7 activity through a PKC delta-mediated phosphorylation of AC7.