Rationally designed chimeric PI3K-BET bromodomain inhibitors elicit curative responses in MYC-driven lymphoma

Targeted inhibitors of bromodomain and extraterminal (BET)-bromodomains and phosphatidylinositol-3-kinase (PI3K) signaling demonstrate potent but self-limited antilymphoma activity as single agents in the context of cellular Myelocytomatosis (cMYC) oncogene-dysregulation. However, combined PI3K and BET inhibition imparts synergistic anticancer activity with the potential for more sustained disease responses due to the mutual antagonism of compensatory epigenetic and signaling networks. Here, we describe the mechanistic and therapeutic validation of rationally designed dual PI3K/BET bromodomain inhibitors, built by linkage of established PI3K and BET inhibitor pharmacophores. The lead candidate demonstrates high selectivity, nanomolar range cellular potency, and compelling in vivo efficacy, including curative responses in the aggressive Eµ-Myc lymphoma model. These studies further support the therapeutic strategy of combined PI3K and BET inhibition and provide a potential step-change in approach to orthogonal MYC antagonism using optimized chimeric small-molecule technology.

High Throughput Screening Targeting the Dengue NS3-NS5 Interface Identifies Antivirals against Dengue, Zika and West Nile Viruses

Dengue virus (DENV) threatens almost 70% of the world's population, with no effective therapeutic currently available and controversy surrounding the one approved vaccine. A key factor in dengue viral replication is the interaction between DENV nonstructural proteins (NS) 5 and 3 (NS3) in the infected cell. Here, we perform a proof-of-principle high-throughput screen to identify compounds targeting the NS5-NS3 binding interface. We use a range of approaches to show for the first time that two small molecules-repurposed drugs I-OMe tyrphostin AG538 (I-OMe-AG238) and suramin hexasodium (SHS)-inhibit NS5-NS3 binding at low μM concentration through direct binding to NS5 that impacts thermostability. Importantly, both have strong antiviral activity at low μM concentrations against not only DENV-2, but also Zika virus (ZIKV) and West Nile virus (WNV). This work highlights the NS5-NS3 binding interface as a viable target for the development of anti-flaviviral therapeutics.

Integrated clinical and genomic evaluation of guadecitabine (SGI-110) in peripheral T-cell lymphoma

Peripheral T-cell lymphoma (PTCL) is a rare, heterogenous malignancy with dismal outcomes at relapse. Hypomethylating agents (HMA) have an emerging role in PTCL, supported by shared mutations with myelodysplasia (MDS). Response rates to azacitidine in PTCL of follicular helper cell origin are promising. Guadecitabine is a decitabine analogue with efficacy in MDS. In this phase II, single-arm trial, PTCL patients received guadecitabine on days 1-5 of 28-day cycles. Primary end points were overall response rate (ORR) and safety. Translational sub-studies included cell free plasma DNA sequencing and functional genomic screening using an epigenetically-targeted CRISPR/Cas9 library to identify response predictors. Among 20 predominantly relapsed/refractory patients, the ORR was 40% (10% complete responses). Most frequent grade 3-4 adverse events were neutropenia and thrombocytopenia. At 10 months median follow-up, median progression free survival (PFS) and overall survival (OS) were 2.9 and 10.4 months respectively. RHOA^G17V mutations associated with improved PFS (median 5.47 vs. 1.35 months; Wilcoxon p = 0.02, Log-Rank p = 0.06). 4/7 patients with TP53 variants responded. Deletion of the histone methyltransferase SETD2 sensitised to HMA but TET2 deletion did not. Guadecitabine conveyed an acceptable ORR and toxicity profile; decitabine analogues may provide a backbone for future combinatorial regimens co-targeting histone methyltransferases.

The epidemiology of Medical Emergency Team calls for orthopedic patients in a teaching hospital: A retrospective cohort study

BACKGROUND

Patients undergoing orthopedic surgery are at risk of post-operative complications and needing Medical Emergency Team (MET) review. We assessed the frequency of, and associations with MET calls in orthopedic patients, and whether this was associated with increased in-hospital morbidity and mortality.

METHODS

Retrospective cohort study of patients admitted over four years to a University teaching hospital using hospital administrative and MET call databases.

RESULTS

Amongst 6344 orthopedic patients, 55.8% were female, the median (IQR) age and Charlson comorbidity index were 66 years (47-79) and 3 (1-5), respectively. Overall, 54.5% of admissions were emergency admissions, 1130 (17.8%) were non-operative, and 605 (9.5%) patients received a MET call. The strongest independent associations with receiving a MET call was the operative procedure, especially hip and knee arthroplasty. Common MET triggers were hypotension (37.5%), tachycardia (25.0%) and tachypnoea (9.1%). Patients receiving a MET call were at increased risk of anemia, delirium, pressure injury, renal failure and wound infection. The mortality of patients who received a MET call was 9.8% compared with 0.8% for those who did not. After adjusting for pre-defined co-variates, requirement for a MET call was associated with an adjusted odd-ratio of 9.57 (95%CI 3.1-29.7) for risk of in-hospital death.

CONCLUSIONS

Approximately 10% of orthopedic patients received a MET call, which was most strongly associated with major hip and knee arthroplasty. Such patients are at increased risk of morbidity and in-hospital mortality. Further strategies are needed to more pro-actively manage at-risk orthopedic patients.

Novel Flavivirus Antiviral That Targets the Host Nuclear Transport Importin α/β1 Heterodimer

Dengue virus (DENV) threatens almost 70% of the world’s population, with no effective vaccine or therapeutic currently available. A key contributor to infection is nuclear localisation in the infected cell of DENV nonstructural protein 5 (NS5) through the action of the host importin (IMP) α/β1 proteins. Here, we used a range of microscopic, virological and biochemical/biophysical approaches to show for the first time that the small molecule GW5074 has anti-DENV action through its novel ability to inhibit NS5–IMPα/β1 interaction in vitro as well as NS5 nuclear localisation in infected cells. Strikingly, GW5074 not only inhibits IMPα binding to IMPβ1, but can dissociate preformed IMPα/β1 heterodimer, through targeting the IMPα armadillo (ARM) repeat domain to impact IMPα thermal stability and α-helicity, as shown using analytical ultracentrifugation, thermostability analysis and circular dichroism measurements. Importantly, GW5074 has strong antiviral activity at low µM concentrations against not only DENV-2, but also zika virus and West Nile virus. This work highlights DENV NS5 nuclear targeting as a viable target for anti-flaviviral therapeutics.

Survey of Irish general practitioners' preferences for continuing professional development

BACKGROUND

Doctors' continuing professional development (CPD) training needs are known to be strongly influenced by national and local contextual characteristics. Given the changing national demographic profile and government-mandated changes to primary care health care provision, this study aimed to investigate Irish General Practitioners' (GPs) perceptions of, and preferences for, current and future CPD programmes.

METHODS

A cross-sectional questionnaire, using closed- and open-ended questions, was administered to Irish GPs, focusing on training needs analysis; CPD course content; preferred format and the learning environment.

RESULTS

The response rate was 719/1000 (71.9%). GPs identified doctor-patient communication as the most important and best-performed GP skill. Discrepancies between perceived importance (high) and current performance (low) emerged for time/workload management, practice finance and business skills. GPs identified clinically-relevant primary care topics and non-clinical topics (stress management, business skills, practice management) as preferences for future CPD. Flexible methods for CPD delivery were important. Gender and practice location (urban or rural) significantly influenced CPD participation and future course preference.

CONCLUSION

The increasing diversity of services offered in the Irish primary care setting, in both clinical and non-clinical areas, should be tailored based to include GP practice location and structure.

Comparison of outcomes for cancer patients discussed and not discussed at a multidisciplinary meeting

OBJECTIVES

Comparison of outcomes for cancer patients discussed and not discussed at a multidisciplinary meeting (MDM).

STUDY DESIGN

Retrospective analysis of the association of MDM discussion with survival.

METHODS

All newly diagnosed cancer patients from 2009 to 2012, presenting to a large regional cancer service in South West Victoria, Australia (620 colorectal, 657 breast, 593 lung and 511 haematological) were recorded and followed up to 5 years after diagnosis. Treatment patterns and survival of patients whose treatment was discussed at an MDM compared to those who were not, were explored.

RESULTS

The proportion of patients presented to an MDM within 60 days after diagnosis was 56% (n = 366) for breast cancer, 59% (n = 363) for colorectal cancer, 27% (n = 137) for haematological malignancies and 60% (n = 355) for lung cancer. Seventy-three percent (n = 886) of patients discussed at an MDM had their tumour stage recorded in their medical records while only 52% (n = 604) of patients not discussed had their tumour stage recorded (P < 0.01). We found for haematological and lung cancer patients that those presented to an MDM prior to treatment had a significant reduction in mortality (lung cancer hazard ratio [HR] 0.62, 95% confidence interval [CI] 0.50-0.76, P < 0.01) (haematological cancer HR 0.58, 95% CI 0.35-0.96, P = 0.03) compared to patients whose cases were not discussed at an MDM after adjusting for the potential cofounders of age, stage, comorbidities and treatment. This was not the case for colorectal and breast cancer patients where there was no significant difference.

CONCLUSION

MDM discussion has been recommended as best practice in the management of cancer patients, however, from a public health perspective this creates potential issues around access and resources. It is likely that MDM presentation patterns and outcomes across tumour streams are linked in complex ways. We believe that our data would demonstrate that these patterns differ across tumour streams and that more detailed work is required to better allocate relatively scarce and potentially costly MDM resources to tumour streams and patient groups that may get the most benefit.

PATI: Patient accessed tailored information: A pilot study to evaluate the effect on preoperative breast cancer patients of information delivered via a mobile application

OBJECTIVES

The information needs of cancer patients are highly variable. Literature suggests an improved ability to modulate personalised stress, increased patient involvement with decision making, greater satisfaction with treatment choices and reduced anxiety levels in cancer patients who have access to information. The aim of this project was to evaluate the effects of a mobile information application on anxiety levels of patients undergoing surgery for breast cancer.

MATERIALS AND METHODS

An application was developed for use with Apple iPad containing information on basic breast cancer biology, different treatments used and surgical techniques. Content and face validity studies were performed. A randomized control trial was designed, with a 1:2 allocation. Data collected include basic demographics and type of surgery. Questionnaires used included: the HADS, Mini-MAC, information technology familiarity and information satisfaction.

RESULTS

A total of 39 women participated. 13 women had access to an iPad containing additional information and 26 women acted as controls. The mean age was 54 and technology familiarity was similar among both groups. Anxiety and depression scores at seven days were significantly lower in control patients without access to the additional information provided by the mobile application (p = 0.022 and 0.029 respectively).

CONCLUSION

Anxiety and depression in breast cancer patients is both multifactorial and significant, with anxiety levels directly correlating with reduced quality of life. Intuitively, information should improve anxiety levels, however, we have demonstrated that surgical patients with less information reported significantly lower anxiety. We advise the thorough testing and auditing of information initiatives before deployment.

Whole-genome association analysis of treatment response in obsessive-compulsive disorder

Up to 30% of patients with obsessive-compulsive disorder (OCD) exhibit an inadequate response to serotonin reuptake inhibitors (SRIs). To date, genetic predictors of OCD treatment response have not been systematically investigated using genome-wide association study (GWAS). To identify specific genetic variations potentially influencing SRI response, we conducted a GWAS study in 804 OCD patients with information on SRI response. SRI response was classified as 'response' (n=514) or 'non-response' (n=290), based on self-report. We used the more powerful Quasi-Likelihood Score Test (the MQLS test) to conduct a genome-wide association test correcting for relatedness, and then used an adjusted logistic model to evaluate the effect size of the variants in probands. The top single-nucleotide polymorphism (SNP) was rs17162912 (P=1.76 × 10(-8)), which is near the DISP1 gene on 1q41-q42, a microdeletion region implicated in neurological development. The other six SNPs showing suggestive evidence of association (P<10(-5)) were rs9303380, rs12437601, rs16988159, rs7676822, rs1911877 and rs723815. Among them, two SNPs in strong linkage disequilibrium, rs7676822 and rs1911877, located near the PCDH10 gene, gave P-values of 2.86 × 10(-6) and 8.41 × 10(-6), respectively. The other 35 variations with signals of potential significance (P<10(-4)) involve multiple genes expressed in the brain, including GRIN2B, PCDH10 and GPC6. Our enrichment analysis indicated suggestive roles of genes in the glutamatergic neurotransmission system (false discovery rate (FDR)=0.0097) and the serotonergic system (FDR=0.0213). Although the results presented may provide new insights into genetic mechanisms underlying treatment response in OCD, studies with larger sample sizes and detailed information on drug dosage and treatment duration are needed.

The at-risk medical student--what more can we do?

Securing a place in medical school is extremely difficult-students who are successful all have similar high levels of academic achievement. So why do some students, and not others, have difficulty with the course, and in some cases, leave the programme? Studies on medical school attrition offer valuable insight into why medical students under-perform. Identification of the 'at-risk' student can trigger additional support and early remediation, helping some students remain in their chosen profession.

A nuclear transport inhibitor that modulates the unfolded protein response and provides in vivo protection against lethal dengue virus infection

BACKGROUND

Dengue virus (DENV) is estimated to cause 390 million infections each year, but there is no licensed vaccine or therapeutic currently available.

METHODS

We describe a novel, high-throughput screen to identify compounds inhibiting the interaction between DENV nonstructural protein 5 and host nuclear transport proteins. We document the antiviral properties of a lead compound against all 4 serotypes of DENV, antibody-dependent enhanced (ADE) infection, and ex vivo and in vivo DENV infections. In addition, we use quantitative reverse-transcription polymerase chain reaction to examine cellular effects upon compound addition.

RESULTS

We identify N-(4-hydroxyphenyl) retinamide (4-HPR) as effective in protecting against DENV-1-4 and DENV-1 ADE infections, with 50% effective concentrations in the low micromolar range. 4-HPR but not the closely related N-(4-methoxyphenyl) retinamide (4-MPR) could reduce viral RNA levels and titers when applied to an established infection. 4-HPR but not 4-MPR was found to specifically upregulate the protein kinase R-like endoplasmic reticulum kinase arm of the unfolded protein response. Strikingly, 4-HPR but not 4-MPR restricted infection in peripheral blood mononuclear cells and in a lethal ADE-infection mouse model.

CONCLUSIONS

4-HPR is a novel antiviral that modulates the unfolded protein response, effective against DENV1-4 at concentrations achievable in the plasma in a clinical setting, and provides protection in a lethal mouse model.

Strategy to control type I error increases power to identify genetic variation using the full biological trajectory

Genome-wide association studies have been successful in identifying loci that underlie continuous traits measured at a single time point. To additionally consider continuous traits longitudinally, it is desirable to look at SNP effects at baseline and over time using linear-mixed effects models. Estimation and interpretation of two coefficients in the same model raises concern regarding the optimal control of type I error. To investigate this issue, we calculate type I error and power under an alternative for joint tests, including the two degree of freedom likelihood ratio test, and compare this to single degree of freedom tests for each effect separately at varying alpha levels. We show which joint tests are the optimal way to control the type I error and also illustrate that information can be gained by joint testing in situations where either or both SNP effects are underpowered. We also show that closed form power calculations can approximate simulated power for the case of balanced data, provide reasonable approximations for imbalanced data, but overestimate power for complicated residual error structures. We conclude that a two degree of freedom test is an attractive strategy in a hypothesis-free genome-wide setting and recommend its use for genome-wide studies employing linear-mixed effects models.

Homeobox genes in obsessive-compulsive disorder

BACKGROUND

Despite evidence that obsessive-compulsive disorder (OCD) is a familial neuropsychiatric condition, progress aimed at identifying genetic determinants of the disorder has been slow. The OCD Collaborative Genetics Study (OCGS) has identified several OCD susceptibility loci through linkage analysis.

METHODS

In this study we investigate two regions on chromosomes 15q and 1q by first refining the linkage region using additional short tandem repeat polymorphic (STRP) markers. We then performed association analysis on single nucleotide polymorphisms (SNP) genotyped (markers placed every 2-4 kb) in the linkage regions in the OCGS sample of 376 rigorously phenotyped affected families.

RESULTS

Three SNPs are most strongly associated with OCD: rs11854486 (P = 0.00005 [0.046 after adjustment for multiple tests]; genetic relative risk (GRR) = 11.1 homozygous and 1.6 heterozygous) and rs4625687 [P = 0.00007 (after adjustment = 0.06); GRR = 2.4] on 15q; and rs4387163 (P = 0.0002 (after adjustment = 0.08); GRR = 1.97) on 1q. The first SNP is adjacent to NANOGP8, the second SNP is in MEIS2, and the third is 150 kb between PBX1 and LMX1A.

CONCLUSIONS

All the genes implicated by association signals are homeobox genes and are intimately involved in neurodevelopment. PBX1 and MEIS2 exert their effects by the formation of a heterodimeric complex, which is involved in development of the striatum, a brain region involved in the pathophysiology of OCD. NANOGP8 is a retrogene of NANOG, a homeobox transcription factor known to be involved in regulation of neuronal development. These findings need replication; but support the hypothesis that genes involved in striatal development are implicated in the pathogenesis of OCD.

Pre-operative determination of an individual's neutrophil response: a potential predictor of early cardiac transplant cellular rejection

BACKGROUND

Success of heart transplantation is affected by allograft rejection, which is known as a lymphocyte-mediated process. Recent studies suggest that neutrophils contribute to this process. We hypothesized that the severity of cardiac rejection can be predicted by evaluating an individual's neutrophil transendothelial migration potential, which can be assessed through artificial stimulation of neutrophils.

METHODS

Eleven patients were recruited from the active heart transplant list. Pre-operative blood samples were stained with neutrophil adhesion molecule (CD11b, CD62L, and PSGL-1) antibodies before and after in vitro stimulation with phorbol 12-myristate 13-acetate (PMA; 1 ng/ml) and lipopolysaccharide (LPS 1 microg/ml), and assessed using flow cytometry. Stimulated neutrophil responses were correlated with rejection grade of the first endomyocardial biopsy sampled 10 days post-operatively.

RESULTS

Neutrophil adhesion molecules are upregulated after artificial stimulation. Pre-operative neutrophil surface CD11b expression after in vitro lipopolysaccharide stimulation correlated with rejection grade detected in the first endomyocardial biopsy sample (R = 0.677; p = 0.022).

CONCLUSION

Pre-operative neutrophil response to in vitro stimuli predicted the rejection grade in the first post-transplant endomyocardial biopsy specimen, suggesting that neutrophils may contribute more to cardiac allograft rejection than previously thought.

Short-term exercise training improves body composition and hyperlipidaemia in HIV-positive individuals with lipodystrophy

Exercise/physical activity is increasingly being advocated as a positive addition to the treatment regimen of HIV-positive individuals. We investigated the effects of 10 weeks' aerobic and resistance training on individuals with HIV-related lipodystrophy. These individuals demonstrated an improvement in exercise tolerance, body composition and blood lipid profiles. Potentially, such changes may contribute to an amelioration of some of the adverse metabolic effects associated with highly active antiretroviral therapy.

Expression of P-glycoprotein and multidrug resistance-associated protein in healthy volunteers and HIV-infected patients

Increased expression of the multidrug efflux transporters P-glycoprotein (P-gp) and multidrug resistance-associated protein (MRP) has been suggested as a potential mechanism for decreased drug availability at certain intracellular sites that provide sanctuary for HIV. Here we investigate the expression of these transporters in peripheral blood mononuclear cells (PBMCs) of HIV-infected patients and healthy volunteers. Venous blood (30 ml) was taken from healthy volunteers (n = 21) and HIV-infected patients (n = 21; 4 antiretroviral drug naive, 17 antiretroviral drug experienced). PBMCs were isolated and fixed. To assess P-gp expression, PBMCs were incubated with an isotype control antibody or an antibody directed to an external epitope of P-gp (UIC2). To assess MRP expression, cells were permeabilized before incubation with either a control antibody or an antibody directed to an internal epitope of MRP (MRPm5). After washing, a secondary phycoerythrin-bound antibody was incubated. After additional wash steps, samples were fixed and analyzed by flow cytometry. The median fluorescence intensity of 5000 events was recorded. Results are expressed as fold increase between isotype control and UIC2/MRPm5 samples. Expression of P-gp in HIV-infected patients (1.42 +/- 0.36) was significantly lower (p = 0.0021; 95% CI, -0.633 to -0.164) than in healthy volunteers (1.82 +/- 0.55). However, MRP expression was similar in HIV-infected patients (1.37 +/- 0.34) and healthy volunteers (1.37 +/- 0.21; p = 0.91; 95% CI, -0.148941 to 0.165191). We conclude that in HIV infection, P-gp expression in total PBMCs is reduced whereas MRP expression appears to be unaltered.

Effect of alpha1-acid glycoprotein on the intracellular accumulation of the HIV protease inhibitors saquinavir, ritonavir and indinavir in vitro

AIMS

Since alpha1-acid glycoprotein (AGP) levels may be raised during HIV infection, we have examined in vitro the effect of increasing the concentration of AGP on the intracellular accumulation of the HIV protease inhibitors saquinavir (SQV), ritonavir (RTV) and indinavir (IDV).

METHODS

U937 cells (5 x 10(6) cells in 5 ml RPMI growth medium) were incubated at 37 degrees C for 18 h with [14C]-SQV (0.1 microCi), [3H]-RTV and [3H]-IDV (0.135 microCi) to a final concentration of 1 microM in the presence of 0, 0.5 and 2.0 mg x ml(-1) AGP. Following extraction in 60% methanol the intracellular drug concentration was determined by liquid scintillation counting.

RESULTS

Binding to AGP (2.0 mg x ml(-1)) reduced the mean intracellular concentration of SQV from 31.5 microM to 7.4 microM (P < 0.0001; 95% CI 19.4-28.8). RTV concentration was also reduced (8.8 microM to 1.6 microM; P < 0.0001; 95% CI 5.4-9.0) as was the concentration of IDV (3.0 microM to 1.5 microM; P < 0.0001; 95% CI 1.1-1.9).

CONCLUSIONS

Reduced intracellular protease inhibitor concentrations in the presence of increasing concentrations of AGP will certainly impact on the antiviral activity in vitro. However, since protease inhibitors are high clearance drugs, free drug concentration will likely remain unaffected in the presence of elevated AGP during chronic oral dosing although there will be an increase in total plasma drug concentration.

A simple sore throat?

Apreviously healthy 26-year-old man presented with a 3-day history of sore throat, fever, rigors, loin pain and vomiting. He was pyrexial (40°C) and tachycardic (104 beats/minute), but had a normal blood pressure. Clinical examination revealed erythematous fauces without any exudates, and bilateral submandibular Iymph node enlargement. There was no meningism or para-spinal tenderness. The platelet count was decreased (108 × 109/litre, normal range (NR) 150–400x109/litre) and white cell count was elevated (16.1×109/litre, NR 4–11x109/litre) with a neutrophilia. Markers of inflammation (erythrocyte sedimentation rate 61mm/h and C-reactive protein 226mg/litre) and urea (11.1 mmol/litre, NR 3–7 mmol/litre) were also elevated.

Chest X-ray and glandular fever slide test were both normal. The patient was started on intravenous ceftriaxone after blood, urine and throat swabs were sent off for culture.

The patient's temperature settled over the next 4 days, and he was converted to oral antibiotics. Gram-negative anaerobes were cultured from the blood; these were identified as Fusobacterium nucleatum, suggesting that the patient had necrobacillosis. Throat swabs failed to grow the organism. In order to exclude an abdominal source for the organism, the patient also had an abdominal ultrasound and a radiolabelled white cell scan, both of which were normal. The patient's inflammatory markers and renal function returned to normal with antibiotic treatment, and he remains well 1 year after his illness.

Isometric muscle strength in alcoholic and nonalcoholic liver-transplantation candidates

Intensity of isometric muscle contractions was measured in alcoholic subjects with cirrhosis (N = 42), nonalcoholic subjects with cirrhosis (N = 33), and normal controls (N = 31). Muscle strength and endurance were comparable in the alcoholic and nonalcoholic cirrhotic subjects for all variables. Both cirrhotic groups were inferior to normal controls for all variables. The quantity x frequency (Q x F) index reported for the period during peak alcohol consumption correlated with 6 muscle-force variables, accounting for 9-20% of the variance. Alcoholic and nonalcoholic cirrhotic subjects did not differ in Quality of Life Inventory (QOLI) scales. Significant correlations, however, were found for the alcoholic cirrhotic subjects but not for the nonalcoholic cirrhotic subjects between quality-of-life indices and muscle strength and endurance. Muscle weakness is thus differentially associated with quality of life in alcoholic cirrhotic subjects as compared with nonalcoholic subjects with cirrhosis even though level of strength and endurance in the two groups is comparable.

The environmental contaminant DDE fails to influence the outcome of sexual differentiation in the marine turtle Chelonia mydas

In many turtles, the temperature experienced during the middle of egg incubation determines the sex of the offspring. The implication of steroid sex hormones as the proximate trigger for sex determination opens the possibility that endocrine-disrupting contaminants may also influence the outcome of sexual differentiation. In this study we investigate the potential effects of DDE (a common DDT metabolite) on sexual differentiation of Chelonia mydas (green sea turtle). Four clutches of eggs collected from Heron Island, Queensland, Australia, were treated with DDE at the beginning of the thermosensitive period for sexual determination. An incubation temperature of 28 degrees C or less produces male hatchlings in this species, whereas 30 degrees C or more produces female hatchlings. Dosed eggs were consequently incubated at two temperatures (27.6 degrees C and 30.4 degrees C) on the upper and lower boundaries of the sex determination threshold for this species. DDE, ranging from 3.3 to 66.5 microg, was dissolved in 5, 10, and 25 microl ethanol and applied to eggshells above the embryo. Less than 2.5 ng/g DDE was present in eggs prior to dosing. Approximately 34% of the applied DDE was absorbed in the eggs, but only approximately 8% of applied DDE was found in embryos. Thus, treated eggs, corrected for background DDE, had up to 543 ng/g DDE. The sex ratio at these doses did not differ from what would be expected on consideration of temperature alone. Incubation time, hatching success, incidence of body deformities, hatching size, and weight were also within the limits of healthy developed hatchlings. This indicates that the eggs of C. mydas in the wild with concentrations of DDE less than 543 ng/g should produce hatchlings with relatively high hatching success, survival rate, and normally differentiated gonads.

Firearm injury in Orleans parish: a 24-month perspective

This study is a retrospective review of all gunshot wounds treated at Charity Hospital, the Orleans Parish designated trauma center, for the 24-month period from November 1993 to November 1995. Its purpose was to define the magnitude of firearm injury in the parish and the impact on the health care system. One-thousand-six-hundred-sixty-nine gunshot wounds were analyzed. Most involved African-American males. Twenty percent were fatal. Two-thousand-forty-three emergent operations were performed. Ten percent of surviving patients had some permanent disability, 6% required institutional care. In 760 patients, initial hospital charges totaled $5,153,516. Extrapolation of these figures to the entire group yields an initial hospital cost of $11,317,392. Transport by the "911" system and in-house trauma team activation were required in most patients. In summary, firearm injury poses a serious economic problem and is a substantial drain on health care providers and their resources.

Object chaining and thought disorder in schizophrenic speech

The phenomenon of object chaining was investigated to determine its relationship to thought disorder in schizophrenia. Samples from thought-disordered schizophrenics (N = 12) and controls (10 non-thought-disordered schizophrenics and 10 normals) were analysed. Using the object subject ratio (OSR) to measure object chaining, we found higher OSRs in the speech of thought-disordered subjects than in that of subjects free of thought disorder. Object chaining correlated with low predictability of speech. We conclude that object chaining is associated with reduced speech comprehensibility and probably contributes to the judgement that thought disorder is present.

The language of schizophrenia: a review and interpretation

Psychopathologists have tended to regard the phenomena of schizophrenic language as reflections of a more basic disturbance of thought. Writings on these topics generally link them together (e.g., Kasanin's Language and Thought in Schizophrenia, 1944). Critchley (1964), from his survey of major aspects of psychotic speech, concluded that the ‘causation of schizophrenic speech affection lies in an underlying thought disorder, rather than in a linguistic inaccessibility’. Differences of opinion are evident as to what the nature of this thinking disorder might be. Regression (Gardner, 1931; Kasanin, 1944), excessive concreteness of thought (Goldstein, 1944; Milgram, 1959) and deficiency in logical deductive reasoning (Von Domarus, 1944) are some of the more prominent hypotheses to be found in the literature relating to this problem.