Shift-field refinement of macromolecular atomic models

The aim of crystallographic structure solution is typically to determine an atomic model which accurately accounts for an observed diffraction pattern. A key step in this process is the refinement of the parameters of an initial model, which is most often determined by molecular replacement using another structure which is broadly similar to the structure of interest. In macromolecular crystallography, the resolution of the data is typically insufficient to determine the positional and uncertainty parameters for each individual atom, and so stereochemical information is used to supplement the observational data. Here, a new approach to refinement is evaluated in which a `shift field' is determined which describes changes to model parameters affecting whole regions of the model rather than individual atoms only, with the size of the affected region being a key parameter of the calculation which can be changed in accordance with the resolution of the data. It is demonstrated that this approach can improve the radius of convergence of the refinement calculation while also dramatically reducing the calculation time.

A multi-omics based ecological analysis of coastal marine sediments from Gladstone, in Australia's Central Queensland, and Heron Island, a nearby fringing platform reef

The impact of anthropogenic factors arising from point and non-point pollution sources at a multi commodity marine port and its surrounding ecosystems were studied using sediment samples collected from a number of onshore (Gladstone Harbour and Facing Island) and offshore (Heron Island and Fitzroy Reefs) sites in Australia's Central Queensland. Sediment samples were analyzed for trace metals, organic carbon, polycyclic aromatic hydrocarbons (PAH), emerging chemicals of concern (ECC) and sterols. Similarly, the biological and biochemical interaction between the reef and its environment was analyzed by the multi-omic tools of next-generation sequencing characterization of the bacterial community and microbial community metabolic profiling. Overall, the trace elements were observed at the lower end of the Australian environmental guideline values at the offshore sites, while higher values were observed for the onshore locations Nickel and copper were observed above the high trigger value threshold at the onshore sites. The levels of PAH were below limits of detection across all sites. However, some of the ECC and sterols were observed at higher concentrations at both onshore and offshore locations, notably, the cholesterol family sterols and 17α-ethynylestradiol. Multi-omic analyses also indicated possible thermal and photo irradiation stressors on the bacterial communities at all the tested sites. The observed populations of γ-proteobacteria were found in combination with an increased pool of fatty acids that indicate fatty acid synthesis and utilisation of the intermediates of the shikimate pathways. This study demonstrates the value of applying a multi-omics approach for ecological assessments, in which a more detailed assessment of physical and chemical contaminants and their impact on the community bacterial biome is obtained.

The safety and efficacy of benzbromarone in gout in Aotearoa New Zealand

BACKGROUND

Benzbromarone is a potent uricosuric but is not widely available due to concerns about hepatotoxicity. In Aotearoa New Zealand, benzbromarone has been available since April 2013, subject to funding restrictions, for patients with inadequate urate-lowering response or intolerance to allopurinol and probenecid.

AIM

To assess the safety and efficacy of benzbromarone in a real-life setting.

METHODS

All patients who received funding for benzbromarone from 1 April 2013 to 30 September 2014 were identified. Prescribers were sent a questionnaire for each individual. Information on demographics, efficacy of previous urate-lowering drugs and reasons for discontinuation were collected. Specific information about the dose, effect on serum urate, adverse effects and liver function tests after commencing benzbromarone was recorded.

RESULTS

Completed questionnaires were returned for 123 of 164 (75%) patients. Mean (SD) serum urate prior to benzbromarone was 0.57 (0.12) mmol/L, and estimated glomerular filtration rate was 50.3 (22.8) mL/min/1.73 m(2) . The median dose of benzbromarone was 100 mg/day (25-200 mg/day). Six months after commencing benzbromarone, mean (SD) serum urate was 0.35 (0.12) mmol/L. Benzbromarone-related adverse events included rash (n = 4), diarrhoea (n = 9), nausea (n = 6) and urate stones (n = 3). Liver function test abnormalities were uncommon and tended to be mild. There were 14 patient deaths; none was considered related to benzbromarone. Allopurinol had been prescribed prior to benzbromarone in 117 of 123 patients; median maximum allopurinol dose was 200 mg/day (range 25-600 mg/day), and 19% patients received allopurinol >300 mg/day.

CONCLUSION

Benzbromarone provides useful urate-lowering efficacy and does not appear unsafe in patients with gout. Urate-lowering therapy prescribing requires further optimisation.

Antibacterials dispensed in the community comprise 85%-95% of total human antibacterial consumption

WHAT IS KNOWN AND OBJECTIVE

Interventions intended to slow the emergence and spread of antibacterial resistance through enhanced antimicrobial stewardship will be more effective if informed by an accurate knowledge of current patterns of antibacterial consumption. For example, knowledge of the relative magnitude of community antibacterial consumption in relation to hospital antibacterial consumption within each nation or region should help guide decisions about the relative importance of community and hospital antimicrobial stewardship programmes. It is commonly stated that community antibacterial consumption comprises approximately 80% of total national antibacterial consumption. We aimed to determine this proportion across a large range of nations.

METHODS

We measured community and hospital antibacterial consumption in New Zealand during 2015, from both reimbursement and purchase data, and compared the New Zealand data with those reported from a large range of other nations during similar time periods.

RESULTS AND DISCUSSION

Community antibacterial consumption comprised approximately 85%-95% of total antibacterial consumption in all nations for which data were available, and in New Zealand comprised a higher proportion than in any other nation. The proportion of total antibacterial consumption comprised by community consumption was significantly higher in countries with relatively high levels of total antibacterial consumption than in countries with relatively low levels of total antibacterial consumption.

WHAT IS NEW AND CONCLUSION

The high proportion of total antibacterial consumption comprised by community antibacterial consumption suggests devoting particular attention to improved community antimicrobial stewardship. These results suggest that improving antimicrobial stewardship in the community may provide greater overall benefits in combating antibacterial resistance than improving antimicrobial stewardship in hospitals.

Three-year experience with access to nationally funded growth hormone (GH) replacement for GH-deficient adults

OBJECTIVE

Treatment of growth hormone (GH)-deficient adults with GH has been shown to improve a range of metabolic abnormalities and enhance quality of life. However, the results of access to nationally funded treatment have not been reported.

DESIGN

Retrospective case series auditing nationally funded treatment of defined GH-deficient adults in New Zealand, with carefully designed entry and exit criteria overseen by a panel of endocrinologists.

PATIENTS

Applications for 201 patients were assessed and 191 approved for funded treatment over the initial 3 years since inception. The majority had GH deficiency following treatment of pituitary adenomas or tumours adjacent to the pituitary.

RESULTS

After an initial 9-month treatment period using serum IGF-I measurements to adjust GH dosing, all patients reported a significant improvement in quality of life (QoL) score on the QoL-AGHDA(®) instrument (baseline (95%CI) 19 (18-21), 9 months 6 (5-7.5)), and mean serum IGF-I SD scores rose from -3 to zero. Mean waist circumference decreased significantly by 2.8 ± 0.6 cm. The mean maintenance GH dose after 9 months of treatment was 0.39 mg/day. After 3 years, 17% of patients had stopped treatment, and all of the remaining patients maintained the improvements seen at 9 months of treatment.

CONCLUSION

Carefully designed access to nationally funded GH replacement in GH-deficient adults was associated with a significant improvement in quality of life over a 3-year period with mean daily GH doses lower than in the majority of previously reported studies.

Age at diagnosis predicts local recurrence in women treated with breast-conserving surgery and postoperative radiation therapy for ductal carcinoma in situ: a population-based outcomes analysis

PURPOSE

The main goal of treating ductal carcinoma in situ (dcis) is to prevent the development of invasive breast cancer. Most women are treated with breast-conserving surgery (bcs) and radiotherapy. Age at diagnosis may be a risk factor for recurrence, leading to concerns that additional treatment may be necessary for younger women. We report a population-based study of women with dcis treated with bcs and radiotherapy and an evaluation of the effect of age on local recurrence (lr).

METHODS

All women diagnosed with dcis in Ontario from 1994 to 2003 were identified. Treatments and outcomes were collected through administrative databases and validated by chart review. Women treated with bcs and radiotherapy were included. Survival analyses were performed to evaluate the effect of age on outcomes.

RESULTS

We identified 5752 cases of dcis; 1607 women received bcs and radiotherapy. The median follow-up was 10.0 years. The 10-year cumulative lr rate was 27% for women younger than 45 years, 14% for women 45-50 years, and 11% for women more than 50 years of age (p < 0.0001). The 10-year cumulative invasive lr rate was 22% for women younger than 45 years, 10% for women 45-50 years, and 7% for women more than 50 years of age (p < 0.0001). On multivariate analyses, young age (<45 years) was significantly associated with lr and invasive lr [hazard ratio (hr) for lr: 2.6; 95% confidence interval (ci): 1.9 to 3.7; p < 0.0001; hr for invasive lr: 3.0; 95% ci: 2.0 to 4.4; p < 0.0001]. An age of 45-50 years was also significantly associated with invasive lr (hr: 1.6; 95% ci: 1.0 to 2.4; p = 0.04).

CONCLUSIONS

Age at diagnosis is a strong predictor of lr in women with dcis after treatment with bcs and radiotherapy.

Offering fragile X syndrome carrier screening: a prospective mixed-methods observational study comparing carrier screening of pregnant and non-pregnant women in the general population

INTRODUCTION

Fragile X syndrome (FXS) is the leading cause of inherited intellectual and developmental disability. Policy development relating to carrier screening programmes for FXS requires input from large studies examining not only test uptake but also psychosocial aspects. This study will compare carrier screening in pregnant and non-pregnant populations, examining informed decision-making, psychosocial issues and health economics.

METHODS AND ANALYSIS

Pregnant and non-pregnant women are being recruited from general practices and obstetric services. Women receive study information either in person or through clinic mail outs. Women are provided pretest counselling by a genetic counsellor and make a decision about testing in their own time. Data are being collected from two questionnaires: one completed at the time of making the decision about testing and the second 1 month later. Additional data are gathered through qualitative interviews conducted at several time points with a subset of participating women, including all women with a positive test result, and with staff from recruiting clinics. A minimum sample size of 500 women/group has been calculated to give us 88% power to detect a 10% difference in test uptake and 87% power to detect a 10% difference in informed choice between the pregnant and non-pregnant groups. Questionnaire data will be analysed using descriptive statistics and multivariate logistic regression models. Interview data will be thematically analysed. Willingness-to-pay and cost effectiveness analyses will also be performed. Recruitment started in July 2009 and data collection will be completed by December 2013.

ETHICS AND DISSEMINATION

Ethics approval has been granted by the Universities of Melbourne and Western Australia and by recruiting clinics, where required. Results will be reported in peer-reviewed publications, conference presentations and through a website http://www.fragilexscreening.net.au. The results of this study will make a significant contribution to discussions about the wider introduction of population carrier screening for FXS.

Evaluation of a multi-disease carrier screening programme in Ashkenazi Jewish high schools

A screening programme for Tay Sachs disease (TSD) carrier status was introduced in high schools in Victoria, Australia in 1997, and was expanded to screen for six other genetic conditions common in the Ashkenazi Jewish population in 2008. The aim of this study was to evaluate the current programme and compare it with an evaluation of the programme when screening was offered for TSD alone. All students from Jewish high schools in Melbourne who offered the programme in 2009 were invited to participate in the study. A purpose-designed questionnaire explored the following domains: knowledge (disease and genetics), reasons for screening, anxiety, and predicted negative feelings if found to be a carrier. Two hundred and seventy-three students were offered screening, and 272 (99.6%) completed the questionnaire. Only two students chose not to have screening. Two hundred and seventy-one students were in the penultimate year of high school (99.6%) and 222 were of Ashkenazi Jewish descent (82.5%). The main reasons for choosing screening were the desire to know carrier status and convenience. Knowledge level decreased and negative feelings increased in the current cohort compared to that when screening was offered for TSD alone. We conclude that the current programme is efficient, although increasing the number of conditions resulted in a decrease in knowledge and increase in predicted negative feelings if found to be a carrier of one of the conditions. This has implications for multi-disease screening programmes that will increase in frequency as more conditions can be screened for and costs diminish.

Use of community genetic screening to prevent HFE-associated hereditary haemochromatosis

HFE-associated hereditary haemochromatosis is a recessive, iron-overload disorder that affects about one in 200 north Europeans and that can be easily prevented. However, genetic screening for this disease is controversial, and so we assessed whether such screening was suitable for communities. Cheek-brush screening for the Cys282Tyr HFE mutation was offered to individuals in the workplace. Outcomes were assessed by questionnaires before and after testing. 11,307 individuals were screened. We recorded no increase in anxiety in individuals who were homozygous for the Cys282Tyr mutation or non-homozygous. Self-reported tiredness before testing was significantly higher in homozygous participants than in non-homozygous participants (chi2 test, p=0.029). Of the 47 homozygous individuals identified, 46 have taken steps to treat or prevent iron accumulation. Population genetic screening for HFE-associated hereditary haemochromatosis can be practicable and acceptable.

Implementation of HaemScreen, a workplace-based genetic screening program for hemochromatosis

There is debate as to whether community genetic screening for the mutation(s) causing hereditary hemochromatosis (HH) should be implemented, due to issues including disease penetrance, health economic outcomes, and concerns about community acceptance. Hemochromatosis is a common preventable iron overload disease, due in over 90% of cases to C282Y homozygosity in the HFE gene. We are, therefore, piloting C282Y screening to assess understanding of genetic information and screening acceptability in the workplace setting. In this program, HaemScreen, education was by oral or video presentation in a group setting. C282Y status was assessed by polymerase chain reaction (PCR) and melt-curve analysis on DNA obtained by cheek-brush sampling. Of eligible participants, 5.8% (1.5-15.8%) attended information and screening sessions, of whom 97.7% (5571 individuals) chose to be tested. Twenty-two C282Y (1 : 253) homozygotes were identified and offered clinical follow-up. There were 638 heterozygotes (1 : 8.7). The determinants for participation have been analyzed in terms of the principles outlined in the Health Belief Model. Widespread screening for HH is readily accepted in a workplace setting, and a one-to-many education program is effective. The level of participation varies greatly and the advertizing and session logistics should be adapted to the specific features of each workplace.

Evaluation of a Tay-Sachs disease screening program

Tay-Sachs Disease (TSD) is an autosomal recessive neurodegenerative disorder. TSD is prevalent in the Ashkenazi Jewish population, and carrier screening programs have been implemented worldwide in these communities. A screening program initiated in 1997 involving the Melbourne Jewish community (Australia) incorporated education, counselling and carrier testing of high-school students aged 15 to 18 years. This study aimed to assess the participation rates, level of knowledge obtained and predicted feelings and attitudes of the students involved. Seven hundred and ten students participated, there was a 67% uptake for testing with a carrier rate of 1 in 28 determined. The level of knowledge of the students following education was high and of relative importance in regard to decision making, as were their feelings and attitudes about genetic testing for carrier status. A significant impediment to test uptake was the need for blood sampling, resulting in a recommendation for the introduction of DNA analysis on cheek brush samples. The evaluation of this program has given a wider scope for further development as well as providing valuable information for the implementation of community screening programs.

Insulin lispro improves postprandial glucose control in patients with diabetes mellitus

Insulin lispro was compared with regular human insulin with respect to glycaemic control in patients with diabetes mellitus on intensive insulin treatment. Sixty-two patients (55 type 1; 7 type 2) from eight study centres in the Czech Republic, Slovenia and the Slovak Republic participated in a 4-month, open-label, randomized, crossover study. Patients administered insulin lispro immediately before meals or regular human insulin 30 min before meals. A test meal (220-400 kcal), based on local and individual dietary habits and consistent for each patient throughout the study was given at baseline and at the end of each treatment. At each test meal visit HbA1c, fasting blood glucose, 1-hour and 2-hour postprandial blood glucose levels were measured. The level of HbA1c (7.6% +/- 1.5% versus 7.4% +/- 1.5%), incidence of hypoglycaemia (41-66% of patients--versus 39-63%) and daily insulin dose (0.67 +/- 0.11 U/kg versus 0.65 +/- 0.11 U/kg) did not differ between treatment groups at endpoint (insulin lispro versus regular human insulin, respectively). Mean 2-hour postprandial blood glucose excursion for the insulin lispro group (0.0 +/- 3.7 mmol/L) was significantly lower (p = 0.035) when compared with the regular human insulin group (1.3 +/- 3.7 mmol/L) at endpoint. Therapy with insulin lispro was therefore associated with a significant improvement in postprandial blood glucose excursion control when compared with regular human insulin, without an increase in rate of hypoglycaemia.

The interleukin-1 receptor antagonist gene: a single-copy variant of the intron 2 variable number tandem repeat (VNTR) polymorphism

A variable number tandem repeat (VNTR) polymorphism exists within intron 2 of the human interleukin-1 receptor antagonist gene, consisting of perfect repeats of an 86-bp sequence. Five allelic variants have been identified wherein the number of repeats varies from two to six. This is the first report of a rare, single-copy allele designated IL1RN*0.

Glycemic control with Humalog Mix25 in type 2 diabetes inadequately controlled with glyburide

BACKGROUND

Humalog Mix25 (Mix25) is a premixed insulin mixture of 25% insulin lispro and 75% neutral protamine lispro.

OBJECTIVE

The aim of this study was to quantitate the improvement in glycemic control achieved with Mix25 versus the maximum dose of glyburide (GB) in patients with type 2 diabetes inadequately controlled with GB.

METHODS

In this randomized, parallel, open-label comparative study, patients with type 2 diabetes received either Mix25 before the morning and evening meals for 4 months or GB 15 mg daily for 4 months. Glycemic control was assessed by glycosylated hemoglobin (HbA1c) measurements, 4-point self-monitored blood glucose profiles, and patient-reported hypoglycemia. Patients also completed a treatment satisfaction questionnaire at the end of the study.

RESULTS

All 172 patients were white; 85 were randomized to receive Mix25. The mean age was 59.5 +/- 8.2 years, and 35.5% (61/172) were men. The mean body mass index was 27.2 kg/m2. The mean duration of type 2 diabetes was 10.2 +/- 6.6 years, and the mean duration of sulfonylurea treatment was 5.8 +/- 5.9 years. The mean HbA1c and fasting blood glucose levels were 10.07% +/- 1.4% and 11.6 +/- 2.8 mmol/L, respectively, in the glyburide group and 9.85% +/- 1.2% and 12.2 +/- 2.9 mmol/L, respectively, in the Mix25 group. There were no statistically significant differences between the treatment groups at baseline for any of the demographic or efficacy variables. At end point, mean HbA1c was significantly lower in the Mix25 group than in the GB group (Mix25, 8.5% +/- 1.3%; GB, 9.4% +/- 1.8%; P = 0.001). A larger decrease from baseline in HbA1c and in all self-monitored blood glucose values was observed in the Mix25 group: -1.4% versus -0.7% for HbA1c, P = 0.004; -2.8 mmol/L versus -1.1 mmol/L for fasting blood glucose, P < 0.01; -5.1 mmol/L versus -1.7 mmol/L for the morning 2-hour postprandial blood glucose, P < 0.001; -2.2 mmol/L versus -0.8 mmol/L for the evening preprandial blood glucose, P < 0.05; and -4.4 mmol/L versus -1.5 mmol/L for the evening 2-hour postprandial blood glucose, P < 0.001. Patients expressed more satisfaction with Mix25 than with GB, as measured by the weighted combined score on a treatment satisfaction questionnaire (2.0 +/- 1.3 vs 0.7 +/- 1.3). The mean hypoglycemia rate (events per patient per 30 days) was significantly higher in the Mix25 group at end point (Mix25, 0.30 +/- 0.53; GB, 0.05 +/- 0.20; P < 0.001).

CONCLUSIONS

Compared with maximum-dose GB, twice-daily injections of Mix25 resulted in improved glycemic control and treatment satisfaction, and were associated with a predictably higher rate of hypoglycemia in this group of patients with type 2 diabetes who were inadequately controlled with maximum-dose GB. Although the inclusion of patients who were inadequately controlled with GB was intended to allow a comparison of the 2 treatments with respect to efficacy and tolerability in a real-life setting, a double-blind comparison in treatment-naive individuals may have resulted in a different outcome.

Allo-tolerance and allorejection responses ex vivo

Spleen cells from fully immune competent mice show different intracellular STAT responses to alloantigen. Cells from mice primed to accept the alloantigen have low STAT 6 and fragmented STAT 4, compared to cells from mice primed to reject the same alloantigen.

Gender differences in the efficacy of fluoxetine and maprotiline in depressed patients: a double-blind trial of antidepressants with serotonergic or norepinephrinergic reuptake inhibition profile

BACKGROUND

Depression has emerged as a contrastive area of gender differences in psychiatry, as epidemiological data has consistently shown depression is twice as common in women as men. The pharmacodynamic effect of antidepressants may also show gender differences, as suggested by reports of better response of young women to non-tricyclic antidepressants.

METHODS

The antidepressive effect of an SSRI (fluoxetine) and a tetracyclic antidepressant with selective norepinephrine reuptake inhibitory effect (maprotiline) was compared in a 6-week, double-blind trial of 105 depressed patients.

RESULTS

No significant difference was observed in the change of HAMD17 total score from baseline to week 6 between fluoxetine- and maprotiline-treated patients. A significant difference was observed in females (fluoxetine, -17.8; maprotiline, -13.9; P=0.017) between treatment groups, but not in males. Amongst females, the difference was significant in women aged <44 years (fluoxetine, -18.4; maprotiline, -12.9; P=0.023) but not > or =44 years.

CONCLUSIONS

Females in their reproductive period are more responsive to SSRI (fluoxetine) than norepinephrinergic tetracyclic antidepressant (maprotiline) treatment. Normal cyclical ovulation, and estrogen release may have a clinically relevant pharmacodynamic interaction with serotonergic antidepressants.

FK 506 and cyclosporin each block antigen-induced T cell receptor signalling that is dependent on CD4 co-receptor and operates in the absence of detectable cytoplasmic calcium fluxes

The T cell hybridoma "171", which lacks CD4 but expresses T cell receptor (TCR) for hen egg white lysozyme, requires introduction of wild-type CD4 for antigen-mediated induction and secretion of interleukin-2 (IL-2). Mutant CD4, which fails to associate with the tyrosine kinase p56lck does not support IL-2 secretion, suggesting that a role of CD4 is to bring cytoplasmic p56lck into alignment for signal transduction to the IL-2 promotor. Using 171, 171-CD4 (wild-type) and 171-CD4 (mutant), we found that IL-2 secretion was inhibited by FK 506 and cyclosporin but not by rapamycin. However, this inhibition was not associated with calcium fluxes since no change in cytoplasmic free calcium levels ([Ca]i; resting level 80 nM) was detectable during antigen stimulation of the 171 or 171-CD4 cells. Thus, although FK 506 and cyclosporin inhibited calcium-dependent signalling to the IL-2 promoter via inhibition of the protein phosphatase calcineurin, it is possible that IL-2 induction via TCR/CD4 requires an FK 506 (and cyclosporin) sensitive step which is independent of cytoplasmic calcium changes.

Measurement of CP-violating asymmetries in B0 decays to CP eigenstates

We present measurements of time-dependent CP-violating asymmetries in neutral B decays to several CP eigenstates. The measurement uses a data sample of 23x10(6) Upsilon(4S)-->BbarB decays collected by the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we find events in which one neutral B meson is fully reconstructed in a CP eigenstate containing charmonium and the flavor of the other neutral B meson is determined from its decay products. The amplitude of the CP-violating asymmetry, which in the standard model is proportional to sin2beta, is derived from the decay time distributions in such events. The result is sin2beta = 0.34+/-0.20 (stat)+/-0.05 (syst).

An efficacy analysis of olanzapine treatment data in schizophrenia patients with catatonic signs and symptoms

Thirty-five patients suffering from schizophrenia, as diagnosed by the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, were preselected from 7 clinical trials according to a priori criteria of catatonic signs and symptoms based on 3 Positive and Negative Syndrome Scale (PANSS) items: scores for PANSS item 19 (mannerism and posturing) and either item 4 (excitement) or item 21 (motor retardation) had to exceed or equal 4 at baseline. This particular patient population represents a severely psychotic sample: mean +/- SD PANSS total scores at baseline were 129.26 +/- 19.76. After I week of olanzapine treatment, mean PANSS total score was decreased significantly (-13.14; p < .001), as was mean PANSS total score after 6 weeks of olanzapine treatment (-45.16; p < .001); additionally, the positive subscale, negative subscale, and mood scores improved significantly. A significant improvement in the catatonic signs and symptoms composite score was also observed at week 6 (-4.96; p < .001). The mean +/- SD daily dose of olanzapine was 18.00 +/- 2.89 mg after 6 weeks of treatment. The present data analysis suggests the efficacy of olanzapine in the treatment of severely ill schizophrenic patients with nonspecified catatonic signs and symptoms.

Evidence for the effectiveness of olanzapine among patients nonresponsive and/or intolerant to risperidone

BACKGROUND

This multicenter, open-label study evaluated the efficacy and safety of olanzapine in patients with schizophrenia who had been nonresponsive or intolerant to a course of risperidone (mean duration of risperidone treatment = 46.3 days).

METHOD

A total of 34 patients with DSM-III-R and ICD-9 schizophrenia entered this trial. Twenty-five patients were nonresponsive to previous risperidone treatment, 6 patients were intolerant to the risperidone treatment, and 3 patients listed both reasons for discontinuation of risperidone. Patients were treated across a dose range of 5 to 25 mg/day of olanzapine. The primary efficacy variable was baseline to endpoint change in Positive and Negative Syndrome Scale (PANSS) score. Safety was assessed using the Clinical Global Impressions-Severity of Illness scale.

RESULTS

Improvement from baseline PANSS score (mean +/- SD PANSS score = 119.4 +/- 26.9) was evident at the week-6 midpoint (-22.2 +/- 19.5) and at the week-14 endpoint (-28.7 +/- 22.3). On average, severity ratings were reduced from baseline by 25% after 14 weeks of olanzapine therapy. Twenty olanzapine-treated patients (58.8%) achieved the a priori-defined response criterion of > or = 20% reduction in PANSS total score. Among patients who met the response criterion, 50% (10/20) had done so by the fourth week. These clinical improvements occurred across a broad range of symptom domains and included reductions in PANSS positive, negative, general psychopathology, and mood subscores. No statistically significant differences were found on any efficacy measure at any visit between the patients who were nonresponsive to risperidone compared with those who were intolerant to risperidone. Olanzapine was well tolerated, with no subject discontinuing early owing to an intolerable adverse event that could be conclusively linked to olanzapine.

CONCLUSION

The results of this open-label study suggest that olanzapine may be an effective alternative for schizophrenic patients who are nonresponsive and/or intolerant to risperidone treatment. Moreover, the results underscore the differential pharmacology that exists among the newer antipsychotic agents.

An ex vivo model of tolerance vs. rejection: comparison of different signal transducers and activators of transcription, STAT1, STAT4, STAT5 and STAT6

An ideal for clinical organ transplantation is for the recipient to develop graft-specific immune tolerance. Although tolerance may occur, there is no way of identifying those recipients who are tolerant vs. those still capable of rejecting their graft. Thus immunosuppressive therapy is normally continued throughout life with the attendant risks of infection, neoplasia, and unwanted side effects of the immunosuppressive drugs. A surrogate marker of specific immune non-responsiveness would permit identification of graft-tolerant individuals who may then be weaned off all immunosuppression. Here we present a model which characterises discrete components of a tolerant, vs. aggressive, immune response. In rodents, new populations of tolerant, regulatory cells can be generated for a foreign graft if first exposure of the T cell receptor (TCR) to graft antigen coincides with blockade of the CD4 and CD8 co-receptors of the TCR. Once established, this type of peripheral tolerance is very robust. We have exploited an ex vivo model to compare in vivo-derived allo-tolerant lymphocytes with their counterpart which have been primed to reject the same allo-antigen. The model has revealed differential STAT (Signal Transducers and Activators of Transcription) responses associated with tolerance, vs. rejection, which have not been previously described. This approach will identify candidate surrogate markers of immune response status for potential clinical application.

Medial temporal lobe width on CT scanning in Alzheimer's disease: comparison with vascular dementia, depression and dementia with Lewy bodies

A simple linear measurement of the minimum width of the medial temporal lobe (MTL) on angled CT scans has been suggested as an accurate ante-mortem marker for Alzheimer's disease (AD). To determine the clinical utility and specificity of this finding, we performed angled CT scans with 5-mm slices in 116 subjects referred to a geographically based Old Age Psychiatry service in Newcastle. Diagnoses were of NINCDS/ADRDA AD (n = 69, 36 probable and 33 possible). NINDS/AIREN vascular dementia (VaD, n = 25), consensus criteria for dementia with Lewy bodies (DLB, n = 9) and DSM-IV criteria for major depression (n = 13). Subjects were well matched for age. Minimum MTL width was significantly greater in depressed subjects (13.7 mm) compared to those with dementia, though no differences were seen within the dementia groups (AD 10.8, VaD 10.4, and DLB 10.9 mm). An MTL width below 11.5 mm had a sensitivity of 54% (56/103) and a specificity of 77% (10/13) for distinguishing dementia from depression. We conclude that a single cross-sectional measurement of MTL width on CT does not help differentiate between different types of dementia, though it may provide some supportive evidence when distinguishing depression from dementia.

P53 autoantibodies in 1006 patients followed up for breast cancer

Serial plasma samples from 1006 patients with breast cancer revealed: (i) no correlation of p53 autoantibody status with disease status at the time of sample collection, or with menopausal status at time of primary diagnosis of breast cancer; (ii) 155 out of 1006 (15%) of patients were positive for p53 autoantibodies, and these patients tended to have a persistent autoantibody status throughout follow up, irrespective of disease behaviour; and (iii) where a negative autoantibody status was found at primary diagnosis of breast cancer, this negative status persisted throughout follow up, irrespective of later disease behaviour. We conclude that screening for p53 autoantibody status is not informative on residual tumour activity nor on therapeutic responsiveness.

A novel exon within the mdm2 gene modulates translation initiation in vitro and disrupts the p53-binding domain of mdm2 protein

The mdm2 protein interacts with a number of proteins involved in cell growth control. Such interactions favour cell proliferation and may explain the oncogenic potential of mdm2 when over-expressed in cells. Interaction with the tumour suppressor p53 involves the N-terminus of mdm2 and targets p53 for rapid degradation by the ubiquitin pathway. We now describe a novel, highly conserved exon of mdm2 (exon alpha) which includes an in-frame UGA stop codon. Expression of exon alpha disrupts in vitro translation of the p53 binding domain of mdm2. We propose that exon alpha induces translation re-initiation at an internal AUG codon within the mdm2 alpha mRNA isoform. The putative mdm2 alpha protein lacks the N-terminus of mdm2 and shows little, if any, binding capacity for p53. Mdm2 alpha mRNA is expressed in a tissue-specific manner and is observed predominantly in testis and peripheral blood lymphocytes. We propose that mdm2 alpha expression may provide a mechanism for uncoupling mdm2-p53 interaction in certain cell types and/or under specific conditions of cell growth.

Proteolytic cleavage of p53 mutants in response to mismatched DNA

Interaction of p53 with mismatched DNA induces proteolytic cleavage with release of a 35-kDa protein fragment from the p53-DNA complexes. The 35-kDa cleavage product is activated for specific biochemical function(s) and may play a role in the cellular response to DNA damage (Molinari et al (1996) Oncogene 13: 2077-2086; Okorokov et al (1997) EMBO J 16: 6008-6017). In the present study we have asked if mutants of p53 retain the ability to undergo similar proteolytic cleavage, and compared sequence-specific 'DNA contact' with 'structural' mutants commonly found in human cancer. In addition, a series of phosphorylation site mutants were generated to investigate the possible effects of phosphorylation/dephosphorylation on the proteolytic cleavage of p53. All mutants tested bound to a mismatched DNA target in vitro. Moreover, studies in vitro and in vivo indicate that p53 mutants with intact conformational structure (as determined by immunoreactivity with PAb246 and PAb1620) retain the ability to undergo proteolytic cleavage similar, if not identical, to the wild-type p53 protein. Our results suggest that the capacity for p53 to bind mismatched DNA is independent of structural conformation of the central core domain. Proteolytic cleavage, however, is crucially dependent upon a wild-type conformation of the protein.

Evidence to support a change in follow-up policy for patients with breast cancer: time to first relapse and hazard rate analysis

The ideal follow-up for patients with cancer should be sensitive to the likelihood of relapse, for prompt investigation and treatment if indicated, together with the support of patient confidence. The current British Association of Surgical Oncologists guidelines for patients with breast cancer suggest intensive follow-up, including 3-monthly clinic visits during the first 2 years. These recommendations place increasing demands on clinical resources. The combined outcome of screening, early detection, dedicated clinical services that emphasize rapid diagnosis and concomitant improved survival, have resulted in increasing absolute numbers of diagnosed breast cancer patients in follow-up clinics. This article examines the follow-up of breast cancer patients to determine if the convention should be adjusted to obtain more from current resources while maintaining equivalent patient care. The data on all patients with breast cancer attending one general oncology clinic were examined in order to determine the pattern of relapse. Analyses identified: (1) the time to relapse at any site and at specific sites; and (2) the prognostic significance of three factors for subsequent relapse, namely nodal status, menopausal status and T stage at diagnosis. In 416 consecutive patients, the annual rate of relapse of breast cancer was found to increase progressively over the first 4 years. Nodal disease was the most important single variable as a predictor of relapse. The annual hazard rate for relapse for node positive patients in the first year was 5%; this increased to 10% and 14% in years three and four respectively. In contrast, in those patients who were node negative at diagnosis (302/416; 73%), the hazard rate for relapse was 1% in year one, increasing to 5% in years three and four. Intensive early follow-up of breast cancer patients provides no clear clinical gain for the great majority of patients, since early relapse is rare in the first year. The use of clinical funds and staff resources might be optimized to focus clinical follow-up on those patients at risk of recurrence. We suggest that all patients should continue to be monitored and receive psychological care through access to their general practitioner, skilled breast care nurses and specialized counsellors. Any patient at risk, or developing symptoms of relapse, would have immediate clinical access to the oncologist for diagnostic investigations. This strategy would optimize psychological patient care and use the full backup of clinical resources during the prolonged period over which relapse becomes more probable.

Wild-type p53 protein shows calcium-dependent binding to F-actin

Nuclear localization of p53 is required for p53 to detect and respond to DNA strand abnormalities and breaks following DNA damage. This leads to activation of the tumour suppressive functions of p53 resulting in either cell cycle arrest and DNA repair; or apoptosis. Critical functional changes in DNA which require strand breaks, including gene rearrangement, may transiently mimic DNA damage: here it is important not to trigger a p53 response. The fine control of p53 in these different circumstances is unknown but may include transient sequestering of p53 in the cytoplasm. Reversible nuclear-cytoplasmic shuttling is an intrinsic property of p53 (Middeler et al., 1997) associated with cell cycle-related changes in p53's subcellular distribution. Takahashi and Suzuki (1994) described p53 inactivation by shuttling to the cytoplasm and Katsumoto et al. (1995) found wild-type p53 to be closely associated with cytoplasmic actin filaments during DNA synthesis. Here we show that, in the presence of free calcium ions, p53 binds directly to F-actin with a dissocation constant of about 10 microM. Thus, part of the regulatory machinery in normal cell cycling may involve p53-actin interactions regulated by calcium fluxes and the dynamic turnover of F-actin.

Mutational biosynthesis of novel rapamycins by a strain of Streptomyces hygroscopicus NRRL 5491 disrupted in rapL, encoding a putative lysine cyclodeaminase

The gene rapL lies within the region of the Streptomyces hygroscopicus chromosome which contains the biosynthetic gene cluster for the immunosuppressant rapamycin. Introduction of a frameshift mutation into rapL by phiC31 phage-mediated gene replacement gave rise to a mutant which did not produce significant amounts of rapamycin. Growth of this rapL mutant on media containing added L-pipecolate restored wild-type levels of rapamycin production, consistent with a proposal that rapL encodes a specific L-lysine cyclodeaminase important for the production of the L-pipecolate precursor. In the presence of added proline derivatives, rapL mutants synthesized novel rapamycin analogs, indicating a relaxed substrate specificity for the enzyme catalyzing pipecolate incorporation into the macrocycle.

Amplification of natural regulatory immune mechanisms for transplantation tolerance

There is a need to derive donor-specific tolerance in clinical organ transplantation, where potential benefits remain overshadowed by chronic rejection and side effects of continual immunosuppressive therapy. It is known that the mature immune system in mice can be reprogrammed to accept a foreign graft as if it were "self." Here we show that, once generated, this state of operational tolerance becomes self-sustaining, imposing itself on new cohorts of lymphocytes as they arise. These new cohorts retain specificity for the tolerizing antigen and can be selectively amplified to tolerate new antigens that have linked expression with the original tolerogen. Regulation is critically dependent upon the continuous presence of tolerizing antigen and is mediated by the CD4+ lymphocyte population. We propose that such natural mechanisms of immune regulation may eventually be exploited for transplantation tolerance, even in fully immune-competent recipients.

Effect of dietary fat on the pharmacokinetics and pharmacodynamics of cyclosporine in kidney transplant recipients

OBJECTIVE

To investigate the effect of dietary fat on the pharmacokinetics and pharmacodynamics of cyclosporine.

METHODS

Sixteen stable kidney transplants recipients (mean age, 50.4 years; age range, 19 to 63 years; six women) who were maintained on oral cyclosporine therapy were randomized to receive a high- or low-fat diet for periods of 7 days in a balanced crossover study. The crossover was separated by a 7-day washout period, when the usual diet was followed. Oral cyclosporine was taken once daily with breakfast. Twenty-four-hour pharmacokinetic studies were conducted during each dietary period on day 6 after oral cyclosporine and on day 7 after a 3-hour intravenous cyclosporine infusion (30% of oral dose). Sequential blood samples were also taken after the oral dose on day 6 for lymphocyte transformation studies.

RESULTS

The mean breakfast fat intake and total daily fat intake were 6.5 and 5.5 times higher, respectively, during the high-fat diet than during the low-fat diet. The bioavailability and clearance of cyclosporine were found to be significantly higher during the high-fat diet (p = 0.02 and p = 0.01, respectively). As a consequence, the area under the blood concentration-time curve (AUC) after the oral dose was not significantly different between the two diets. There were no significant differences in concanavalin A-stimulated proliferation of peripheral blood lymphocytes between the high- and low-fat diets.

CONCLUSIONS

An increased fat content of food significantly increases cyclosporine bioavailability and clearance. However, this is unlikely to be of clinical importance during oral administration because the AUC and pharmacodynamics of cyclosporine are not affected significantly.

New immunosuppressive reagents to aid the induction of tolerance in organ graft recipients

Thirty years ago when the first immunosuppressive agents became available for clinical grafting, the procedure was regarded with great skepticism by the medical profession as a pastime for ignorant surgeons with results that at best were poor. With the introduction of cyclosporin 15 years ago, the results of organ transplantation improved, and for the first time it was possible to transplant lung and pancreas with a reasonable outcome. Now more than 200,000 organ grafts have been performed worldwide and the procedure is an important established part of therapeutic surgery.