The effect of pretreatment patient characteristics on the allocation of treatment for advanced epithelial ovarian cancer

6514

Background: While the standard treatment of advanced ovarian cancer is maximum cytoreductive surgery followed by adjuvant platinum-based chemotherapy, some patients are treated with neoadjuvant chemotherapy (NCT) with or without surgery and others receive no therapy. The primary objective of this study was to identify pre-treatment characteristics associated with receipt of non-standard treatment. Methods: 11,155 patients with clinical stage recorded were selected from 25,784 patients diagnosed between 2003 and 2005 from the National Cancer Database, a registry sponsored by the American Cancer Society and the American College of Surgeons. Among the 11,155 patients, 9,015 were stage IIIC or IV. 383 (4.25%) were excluded due to missing treatment information leaving 8,632 patients for the analysis. Evaluable variables included demographics, health insurance, Charlson co-morbidity score, area-level income and facility characteristics. Multivariate logistic regression analyses were performed to assess factors associated standard care versus suboptimal care. Results: In this cohort, 5,517 (63.91%) of patients received optimal treatment. In multivariate analyses, Uninsured and Medicaid-insured patients were less like likely to receive optimal treatment as compared to privately insured patients (OR = 0.58, 95% CI 0.46–0.73; OR = 0.61, 95% CI = 0.49–0.76, respectively). Blacks and Hispanics were also less likely receive optimal treatment (OR = 0.60, 95% CI 0.50–0.72, OR = 0.72, 95% CI 0.57–0.90, respectively) compared to whites. Patients with a Charlson comorbidity score of 1, 2, or 3 were also less likely to receive optimal care (OR = 0.84 95% CI 0.74–0.96; OR = 0.46 95% CI 0.34–0.62; OR = 0.27 95% CI 0.13–0.55, respectively). Treatment in a comprehensive cancer facility or teaching hospital compared to community cancer hospitals was associated with optimal treatment (OR = 1.28 95% CI 1.10–1.48; OR = 1.66 95% CI 1.43–1.93). Conclusions: In this large retrospective multi-institutional cohort, approximately one-third of patients with clinical stage III and IV ovarian cancer did not receive optimal treatment. Pretreatment patient characteristics, such as race, insurance status, age, medical cormorbidities, and facility-type, were strongly associated with suboptimal treatment.

No significant financial relationships to disclose.

The association of pretreatment patient characteristics on the allocation of treatment in stage II ovarian cancer

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Background: In high-risk early stage ovarian cancer, surgery followed by adjuvant chemotherapy demonstrates improved survival in prospective trials. The objective of this research was to document patterns of care in the treatment of stage II epithelial ovarian cancer and those factors associated with less than optimal treatment. Methods: The study population was selected from patients diagnosed with ovarian cancer in 2003 to 2005 and reported to the National Cancer Database, a hospital-based cancer registry. 2,252 (93.8%) patients had sufficient information for analysis. Demographics, health insurance, Charlson co-morbidity score, area-level income, and facility characteristics were analyzed as factors potentially associated with treatment. Multivariate logistic regression was performed to assess factors associated with optimal treatment versus suboptimal treatment. Results: Among the women 2,252 women included in the study 1,533 (68.0%) received surgery and chemotherapy and 719 (32.0%) received surgery alone. In multivariate analysis, Black and Hispanic patients were significantly less like likely to receive optimal treatment as compared to white patients (OR = 0.54, 95% CI 0.36–0.82; OR = 0.51, 95% CI = 0.34–0.79, respectively). Women 75 years of age or more were significantly less likely to receive optimal treatment (OR = 0.43 95% CI 0.28–0.67) compared to women less than 53 years. Treatment in a comprehensive cancer facility or teaching hospital compared to community cancer hospitals was positively associated with optimal treatment (OR = 1.40 95% CI 1.02–1.92; OR = 1.89 95% CI 1.38–2.59). Among the 719 patients not receiving chemotherapy, 205 had no reason recorded, and the majority with information (456/514) stated that chemotherapy was not part of planned therapy. Only 33 patients (6.4%) were recorded as refusing recommended chemotherapy. Conclusions: Although only a small proportion of newly diagnosed cases, Stage II ovarian cancer patients have a high probability of benefiting from adjuvant chemotherapy, which improves the likelihood of long-term survival and cure. Further studies are needed to address the patient, clinician and health system factors associated with suboptimal treatment.

No significant financial relationships to disclose.

The use of thrombin in the radiology department

Thrombin is a naturally occurring coagulation protein that converts soluble fibrinogen into insoluble fibrin and plays a vital role in the coagulation cascade and in turn haemostasis. Thrombin also promotes platelet activation. In the last few years, there has been a rapid increase in the use of thrombin by radiologists in a variety of clinical circumstances. It is best known for its use in the treatment of pseudoaneurysms following angiography. However, there are now a variety of cases in the literature describing the treatment of traumatic, inflammatory and infected aneurysms with thrombin in a variety of locations within the human body. There have even been recent reports describing the use of thrombin in conventional aneurysms as well as ruptured aneurysms. Its use has also been described in the treatment of endoleaks (type II) following aneurysm repair. In nearly all of these cases, treatment with thrombin requires imaging guidance. Recently, thrombin has also been used as a topical treatment post-percutaneous intervention to reduce or stop bleeding. Most radiologists have only a limited knowledge of the pharmacodynamics of thrombin, its wide range of utilisation and its limitations. Apart from a few case reports and case series, there is little in the radiological literature encompassing the wide range of applications that thrombin may have in the radiology department. In this review article, we comprehensively describe the role and pathophysiology of thrombin, describing with examples many of its potential uses. Techniques of usage as well as pitfalls and limitations are also described.

Imaging of horseshoe kidneys and their complications

Horseshoe kidney is the most common renal fusion anomaly and the patients are prone to a variety of complications, such as stone disease, pelviureteric junction (PUJ) obstruction, trauma, infections and tumours. As result of the abnormal anatomy of a horseshoe kidney, imaging and treatment pathways vary substantially from the normal kidney. In this review, we describe the role of modern imaging in depicting horseshoe kidneys and their complications, in tandem with the role the interventional radiologist plays in treating these patients.

A case of back pain associated with neurology in a young man

BACKGROUND

We present the case of a 14-year-old with a 3-month history of back pain, who on presentation, was demonstrated to have neurological signs.

METHOD

Investigation with radiographs and subsequent magnetic resonance imaging was performed, which demonstrated an expansile lesion in the tenth thoracic vertebra with posterior extension causing spinal cord compression. This was treated with surgical resection and spinal cord decompression.

RESULTS

Diagnosis of aneurysmal bone cyst was made following histopathological examination of the resected lesion.

CONCLUSION

Back pain in childhood is a significant and often sinister symptom, which requires careful evaluation.

Use of Cryopreserved Cells for Enabling Greater Flexibility in Compound Profiling

Measurement of intracellular calcium release following agonist challenge within cells expressing the relevant membrane protein is a commonly used format to derive structure-activity relationship (SAR) data within a compound profiling assay. The Fluorometric Imaging Plate Reader (FLIPR) has become the gold standard for this purpose. FLIPR traditionally uses cells that are maintained in continuous culture for compound profiling of iterative chemistry campaigns. This supply dictates that assays can only be run on 4 of 5 weekdays, or alternative cell culture machinery is required such that plating can occur remotely at the weekend. The data reported here demonstrate that high-quality compound profiling data can be generated from the use of cryopreserved cells and that these cells can also be plated at various densities to generate equivalent data between 24 and 72 h post-plating. Hence, the authors report a method that allows data generation throughout the week and without the requirement of highly automated cell culture or continuous culture. ( Journal of Biomolecular Screening 2008:354-362)

Imaging of adenomyomatosis of the gall bladder

Adenomyomatosis is a relatively common abnormality of the gall bladder, with a reported incidence of between 2.8 and 5%. Although mainly confined to the adult study group, a number of cases have been reported in the paediatric study group. It is characterized pathologically by excessive proliferation of the surface epithelium and hypertrophy of the muscularis propria of the gall bladder wall, with invagination of the mucosa into the thickened muscularis forming the so-called 'Rokitansky-Aschoff' sinuses. The condition is usually asymptomatic and is often diagnosed as an incidental finding on abdominal imaging. The radiological diagnosis is largely dependent on the visualization of the characteristic Rokitansky-Aschoff sinuses. As the condition is usually asymptomatic, the importance of making a correct diagnosis is to prevent misinterpretation of other gall bladder conditions such as gall bladder cancer, leading to incorrect treatment. In the past, oral cholecystography was the main imaging method used to make this diagnosis. In most institutions, oral cholecystography is no longer carried out, and the diagnosis is now more commonly seen on cross-sectional imaging. In this review article, we describe the manifestations of adenomyomatosis on the various imaging methods, with an emphasis on more modern techniques such as magnetic resonance cholangiopancreatography. A brief section on oral cholecystography to aid readers familiar with this technique in understanding the comparable imaging features on more modern imaging techniques is included.

The imaging of coeliac disease and its complications

Coeliac disease is a malabsorption syndrome in which dietary gluten damages the small bowel mucosa. Gluten contains gliadin, the primary toxic component that is primarily found in wheat, barley and rye products. The initial diagnosis of coeliac disease is usually made by endoscopic biopsy of the jejunum although sometimes imaging features can suggest the diagnosis. Once a diagnosis is made, patients need to be diet compliant and monitored for potential complications. Many complications are more common when dietary compliance is poor. Complications include intussusception (usually intermittent), ulcerative jejunitis, osteomalacia, cavitating lymph node syndrome and an increased risk of malignancies such as lymphoma, adenocarcinoma and squamous cell carcinoma. Radiological evaluation is central in the evaluation of these complications. Imaging may assist both in the diagnosis and staging of complications as well as enabling radiological guided percutaneous biopsy for complications of coeliac disease such as lymphoma. As coeliac disease is a relatively common disorder, it is likely that most radiologists will encounter the disease and its potential complications. The aim of this review article is to discuss and illustrate the role of modern radiology in evaluating the many presentations of this complex disease.

The effect of high-dose enteral glutamine on the incidence and severity of mucositis in paediatric oncology patients

BACKGROUND/OBJECTIVE

The study was conducted to determine if enteral glutamine, 0.65 g kg(-1) daily for 7 days, is effective in reducing the incidence and severity of mucositis in paediatric oncology patients when given alongside chemotherapy. The study was carried out at St James's University Hospital, Leeds, UK.

SUBJECTS/METHODS

This was a randomized study using the patients as their own controls. Seventy-six patients undergoing treatment for paediatric malignancy having at least two identical courses of chemotherapy and at risk of developing mucositis participated in the study. Patients received one course of chemotherapy with glutamine and an identical course without. Alternate patients were allocated to have glutamine with course 1 or with course 2. The severity of symptoms of mucositis and the duration of enteral and parenteral nutrition were recorded. Daily ammonia levels were measured.

RESULTS

Fifty patients completed the study. No statistical significance with regard to symptoms of mucositis was found. Fewer children receiving glutamine required parenteral nutrition (P=0.049), and the duration of parenteral nutrition was less (P=0.023). No adverse effects attributed to taking the glutamine were observed.

CONCLUSIONS

The study showed that high-dose enteral glutamine did not reduce the incidence and severity of oral mucositis as determined by subjective toxicity measurements, but did show a significant reduction in parenteral nutrition usage. No adverse cumulative effect of this oral glutamine dose was observed.

Fc dependent mechanisms are necessary for ADCC and effective depletion of murine B cells by humanized anti-CD19 mAb. (131.27)

B cell depletion is an effective treatment for autoimmune diseases and B cell malignancies. Successful B cell depletion may be limited by the surface expression of the target antigen. CD19 represents an attractive molecular target that is expressed on the surface of early B cell progenitors through the latter stages of B cell differentiation. In this study we developed a fully humanized CD19 monoclonal antibody mAb 19-1 and two variants with either reduced (19-2) or enhanced (19-3) Fc-FcR binding and evaluated their potential to deplete B cells. In vitro antibody-dependent cellular-mediated cytotoxicity (ADCC) activity of 19-3>19-1>19-2 on human peripheral blood B cells as well as B cell lines (Raji, Daudi, and Ramos) by LDH release or Granzyme B assays. We evaluated in vivo depletion in human CD19 transgenic mice using 19-1, 19-2, and 19-3. 19-1 at 50 ug/mouse i.v. depleted most B cells in blood, spleen, and bone marrow after 7 days following treatment. 19-2 showed little depletion of B cells at a high dose, whereas 19-3 efficiently eliminated B cells in the spleen and blood at low dose. These data demonstrate that transgenic mice expressing human antigens provide an excellent model for testing humanized antibodies in depletion studies, and that Fc-FcR interactions represent the most important mechanism. Targeting B cells with anti-CD19 mAb may be a more effective strategy than existing B cell depletion protocols.

Application of real-time and multiplex polymerase chain reaction assays to study leaf blotch epidemics in barley

ABSTRACT Leaf blotch, caused by Rhynchosporium secalis, was studied in a range of winter barley cultivars using a combination of traditional plant pathological techniques and newly developed multiplex and real-time polymerase chain reaction (PCR) assays. Using PCR, symptomless leaf blotch colonization was shown to occur throughout the growing season in the resistant winter barley cv. Leonie. The dynamics of colonization throughout the growing season were similar in both Leonie and Vertige, a susceptible cultivar. However, pathogen DNA levels were approximately 10-fold higher in the susceptible cultivar, which expressed symptoms throughout the growing season. Visual assessments and PCR also were used to determine levels of R. secalis colonization and infection in samples from a field experiment used to test a range of winter barley cultivars with different levels of leaf blotch resistance. The correlation between the PCR and visual assessment data was better at higher infection levels (R(2) = 0.81 for leaf samples with >0.3% disease). Although resistance ratings did not correlate well with levels of disease for all cultivars tested, low levels of infection were observed in the cultivar with the highest resistance rating and high levels of infection in the cultivar with the lowest resistance rating.

In vitro study of foot kinematics using a dynamic walking cadaver model

There is a dearth of information on navicular, cuboid, cuneiform and metatarsal kinematics during walking and our objective was to study the kinematic contributions these bones might make to foot function. A dynamic cadaver model of walking was used to apply forces to cadaver feet and mobilise them in a manner similar to in vivo. Kinematic data were recorded from 13 cadaver feet. Given limitations to the simulation, the data describe what the cadaver feet were capable of in response to the forces applied, rather than exactly how they performed in vivo. The talonavicular joint was more mobile than the calcaneocuboid joint. The range of motion between cuneiforms and navicular was similar to that between talus and navicular. Metatarsals four and five were more mobile relative to the cuboid than metatarsals one, two and three relative to the cuneiforms. This work has confirmed the complexity of rear, mid and forefoot kinematics. The data demonstrate the potential for often-ignored foot joints to contribute significantly to the overall kinematic function of the foot. Previous emphasis on the ankle and sub talar joints as the principal articulating components of the foot has neglected more distal articulations. The results also demonstrate the extent to which the rigid segment assumptions of previous foot kinematics research have over simplified the foot.

High risk health behaviours among adult Jamaicans

The purpose of this study was to assess the prevalence of high risk health behaviours among adult Jamaicans aged 15-49 years in 2000, and to compare the results with the 1993 survey. A nationally representative sample of 2013 persons aged 15-74 years was surveyed in 2000 using cluster sampling in the Jamaica Healthy Lifestyle Survey (Wilks et al, unpublished). Interviewer administered questionnaires and anthropometrical measurements were done. Data for a sub-sample of adults aged 15-49 years were analyzed The sub-sample included 1401 persons (473 men and 928 women). Significantly more men (18.6%) than women (4.3%) reported never having had a blood pressure check (p = 0.0001). Approximately one-third of the women reported that they had never had a Pap smear (36.0%) or a breast examination (31.2%). Current cigarette smoking was reported in 28.6% of men and 7.7% of women (OR 3.73 CI 2.71, 5.15), while 49.0% of men and 15.0% of women ever smoked marijuana (OR 3.28 CI 2.56, 4.20). Significantly more men (28.0%) than women (11.7%) reported ever having a sexually transmitted disease (OR 2.93 CI 2.16, 3.97); having more than one sexual partner in the past year (49.1% vs 11.4%, OR 4.31 CI 3.22, 5.76) and usually using a condom during sexual intercourse (55.3% vs 40.5%, OR 1.3 CI 1.11, 1.68). Between 1993 and 2000, significant trends include: more persons reported having a blood pressure check, a reduction in multiple sexual partners, increased condom use at last sex (women), reduced crack/cocaine use (males) and increased marijuana smoking. Although there were some significant positive lifestyle trends between 1993 and 2000, high risk behaviours remain common among Jamaican adults. Comprehensive health promotion programmes are needed to address these risk behaviours.

Patient-practitioner agreement: does it matter?

BACKGROUND

Good communication is a crucial clinical skill. Previous research demonstrated better clinical outcomes when practitioners and patients agree about the nature of patients' core presenting complaints. We investigated the nature of this agreement and its impact on outcome among depressed primary care patients.

METHOD

We compared presenting problem formulations completed by patients, GPs and therapists in a primary care randomized controlled trial of cognitive-behavioural therapy and non-directive counselling for depression. Participants compiled formulations from a list of 13 potential problems of self-completed questionnaires. Subjects scored at least 14 on the Beck Depression Inventory (BDI) at baseline. Outcome measure for this study included BDI at 4 and 12 months, failure to attend for therapy when referred, dropout from therapy and patient satisfaction.

RESULTS

Among 464 trial patients, 395 received therapy. Patient baseline problem formulations included significantly more items than GPs, who identified significantly more items than therapists. Agreement levels varied according to a range of patient and professional variables. While patients in complete agreement with their therapists about their main problem after assessment had lower average BDI scores at 12 months (9.7 v. 12.8, P=0.03); we found no other significant associations between the extent of agreement and clinical outcome. There were significant (but relatively weak) associations between agreement and aspects of patient satisfaction.

CONCLUSION

Our results suggest that detailed mutual understanding of the presenting complaints may be less important than agreement that the core problem is psychological, and that referral for psychological therapy is appropriate.

Oral glutamine in paediatric oncology patients: a dose finding study

OBJECTIVE

The purpose of this study was to determine the most appropriate dose of oral glutamine to use in a further clinical study in paediatric oncology patients.

DESIGN

This was a phase I, pharmokinetic study.

SETTING

The study was carried out at The Yorkshire Regional Centre for Paediatric Oncology and Haematology, St James's University Hospital, Leeds, UK.

SUBJECTS

Thirteen patients undergoing treatment for paediatric malignancy participated in this study. All 13 completed the study.

INTERVENTIONS

The most appropriate dose was determined by patient acceptability and by plasma glutamine and ammonia levels measured at timed intervals after ingestion of a single glutamine dose.

RESULTS

Doses of 0.35, 0.5 and 0.65 g/kg were well tolerated with no untoward plasma glutamine and ammonia levels. One patient was recruited to a higher dose of 0.75 g/kg, but the plasma glutamine and ammonia levels peaked at 2601 and 155 micro mol/l, respectively. The ammonia level was greater than the acceptable upper limit. It was difficult to disperse the glutamine adequately at this dose, resulting in the suspension being found to be unpalatable and therefore no further patients were recruited at this dose.

CONCLUSION

It was concluded that 0.65 g/kg is a safe dose of glutamine to use in a clinical study in paediatric oncology patients.

Gene targeting in Arabidopsis

Precise modification by gene targeting (GT) provides an important tool for studies of gene function in vivo. Although routine with many organisms, only isolated examples of GT events have been reported for flowering plants. These were at low frequencies precluding reliable estimation of targeting efficiency and evaluation of GT mechanisms. Here we present an unambiguous and straightforward system for detection of GT events in Arabidopsis using an endogenous nuclear gene encoding protoporphyrinogen oxidase (PPO), involved in chlorophyll and heme syntheses. Inhibition of PPO by the herbicide Butafenacil results in rapid plant death. However, the combination of two particular mutations renders PPO highly resistant to Butafenacil. We exploited this feature for selection of GT events by introducing the mutations into the PPO gene by homologous recombination. We have estimated the basal GT frequency to be 2.4 x 10(-3). Approximately one-third of events were true GT (TGT) leading to the anticipated modification of the chromosomal PPO copy. The remaining events could be classified as ectopic GT (EGT) arising by modification of vector DNA by the chromosomal template and its random integration into the Arabidopsis genome. Thus the TGT frequency in our experimental setup is 0.72 x 10(-3). In view of the high efficiency of Arabidopsis transformation, GT experiments of a reasonable size followed by a PCR screen for GT events should also allow for modification of non-selectable targets. Moreover, the system presented here should contribute significantly to future improvement of GT technology in plants.

Update of the follow-up of mortality and cancer incidence among European workers employed in the vinyl chloride industry

Although vinyl chloride is an established cause of liver angiosarcoma, the evidence is inconclusive on whether it also causes other neoplastic and nonneoplastic chronic liver diseases as well as neoplasms in other organs. Furthermore, the shape of the dose-response relation for angiosarcoma is uncertain. We have extended for approximately 8 years the mortality and cancer incidence follow-up of 12,700 male workers in the vinyl chloride industry in four European countries. All-cause mortality was lower than expected, whereas cancer mortality was close to expected. A total of 53 deaths from primary liver cancer (standardized mortality ratio 2.40, 95% confidence interval = 1.80-3.14) and 18 incident cases of liver cancer were identified, including 37 angiosarcomas, 10 hepatocellular carcinomas, and 24 liver cancers of other and unknown histology. In Poisson regression analyses we observed a marked exposure response for all liver cancers, angiosarcoma, and hepatocellular carcinoma. The exposure-response trend estimated for liver cancer in analyses restricted to cohort members with cumulative exposures of <1,500 parts per million-years was close to that estimated for the full cohort (relative risk of 2.0 per logarithmic unit of cumulative dose). No strong relation was observed between cumulative vinyl chloride exposure and other cancers. Although cirrhosis mortality was decreased overall, there was a trend with cumulative exposure.

Pharmacokinetic/pharmacodynamic study of ZD9331, a nonpolyglutamatable inhibitor of thymidylate synthase, in a murine model following two curative administration schedules

ZD9331 is a nonpolyglutamatable antifolate inhibitor of thymidylate synthase currently in clinical development. This enzyme is crucial for DNA synthesis and catalyzes the reductive methylation of dUMP to form thymidylate, which is subsequently converted to dTTP. The pharmacokinetics of two curative antitumor doses of ZD9331 administered by either a single i.p. bolus injection (50 mg/kg) or by 24-h s.c. infusion (3 mg/kg) have been measured in a thymidine salvage-incompetent murine lymphoma model (L5178Y) using a sensitive and specific ELISA. To gain an understanding of the relationship between the pharmacokinetics of ZD9331 and antitumor activity perturbations in tumor, dTTP and dUMP concentrations were also determined. After bolus administration, ZD9331 was eliminated from plasma and tissues relatively rapidly, with terminal elimination (lambda(z) 0-24 h) of 4-6 h. Liver concentrations were 8-fold higher than those measured in the plasma. Kidney and lymphoma drug concentrations were similar to those of plasma, although there was evidence of a slower overall elimination of drug at later time points. Steady-state concentrations of ZD9331 were obtained 4-5 h after the start of the 24 h s.c. infusion. At the end of infusion, elimination rates were similar for plasma and tissues (approximately 3.5 h) but appeared to be slower in the tumor at later time points. Liver concentrations were approximately 4-fold higher, and kidney and tumor concentrations were similar to those in the circulation. Depletion of dTTP and elevation in dUMP in the tumor were consistent with inhibition of thymidylate synthase after both administration schedules, although the time for which dTTP was decreased was longer (approximately 24 h) for the infusional route than for the bolus injection (<16 h). The results suggest that antitumor activity is dependent on attaining adequate drug concentrations to affect dTTP pools as well as on the duration of effective drug levels.

Methods for integrated air sampling and dna analysis for detection of airborne fungal spores

Integrated air sampling and PCR-based methods for detecting airborne fungal spores, using Penicillium roqueforti as a model fungus, are described. P. roqueforti spores were collected directly into Eppendorf tubes using a miniature cyclone-type air sampler. They were then suspended in 0.1% Nonidet P-40, and counted using microscopy. Serial dilutions of the spores were made. Three methods were used to produce DNA for PCR tests: adding untreated spores to PCRs, disrupting spores (fracturing of spore walls to release the contents) using Ballotini beads, and disrupting spores followed by DNA purification. Three P. roqueforti-specific assays were tested: single-step PCR, nested PCR, and PCR followed by Southern blotting and probing. Disrupting the spores was found to be essential for achieving maximum sensitivity of the assay. Adding untreated spores to the PCR did allow the detection of P. roqueforti, but this was never achieved when fewer than 1,000 spores were added to the PCR. By disrupting the spores, with or without subsequent DNA purification, it was possible to detect DNA from a single spore. When known quantities of P. roqueforti spores were added to air samples consisting of high concentrations of unidentified fungal spores, pollen, and dust, detection sensitivity was reduced. P. roqueforti DNA could not be detected using untreated or disrupted spore suspensions added to the PCRs. However, using purified DNA, it was possible to detect 10 P. roqueforti spores in a background of 4,500 other spores. For all DNA extraction methods, nested PCR was more sensitive than single-step PCR or PCR followed by Southern blotting.

Intolerance to an extensively hydrolysed formula mistaken for postoperative diarrhoea in a child with neuroblastoma

BACKGROUND

Persistent diarrhoea has recently been reported as a common problem following surgical resection for advanced abdominal neuroblastoma.

CASE STUDY

A 10-month-old child, who had previously had no nutritional problems whilst undergoing chemotherapy treatment for a stage IV neuroblastoma, developed severe diarrhoea following tumour resection. He required nutritional support and was commenced on a continuous overnight nasogastric feed of a non-milk protein hydrolysate feed (MCT Pepdite 0-2, S.H.S. International Ltd, UK) His diarrhoea persisted and it was assumed that this was a postoperative problem which in time would regress. Two months later the child was admitted with a rectal prolapse, and a colonoscopy and biopsy suggested allergic protocolitis. The diarrhoea resolved rapidly on stopping the feed.

CONCLUSION

Although he was never re-challenged with the non-milk protein hydrolysate, it appears that he had a rare intolerance to an extensively hydrolysed protein formula which was masked by the assumption that his diarrhoea was a postoperative problem.

Randomised controlled trial of non-directive counselling, cognitive-behaviour therapy and usual general practitioner care in the management of depression as well as mixed anxiety and depression in primary care

OBJECTIVES

The aim of this study was to determine both the clinical and cost-effectiveness of usual general practitioner (GP) care compared with two types of brief psychological therapy (non-directive counselling and cognitive-behaviour therapy) in the management of depression as well as mixed anxiety and depression in the primary care setting.

DESIGN

The design was principally a pragmatic randomised controlled trial, but was accompanied by two additional allocation methods allowing patient preference: the option of a specific choice of treatment (preference allocation) and the option to be randomised between the psychological therapies only. Of the 464 patients allocated to the three treatments, 197 were randomised between the three treatments, 137 chose a specific treatment, and 130 were randomised between the psychological therapies only. The patients underwent follow-up assessments at 4 and 12 months.

SETTING

The study was conducted in 24 general practices in Greater Manchester and London.

SUBJECTS

A total of 464 eligible patients, aged 18 years and over, were referred by 73 GPs and allocated to one of the psychological therapies or usual GP care for depressive symptoms.

INTERVENTIONS

The interventions consisted of brief psychological therapy (12 sessions maximum) or usual GP care. Non-directive counselling was provided by counsellors who were qualified for accreditation by the British Association for Counselling. Cognitive-behaviour therapy was provided by clinical psychologists who were qualified for accreditation by the British Association for Behavioural and Cognitive Psychotherapies. Usual GP care included discussions with patients and the prescription of medication, but GPs were asked to refrain from referring patients for psychological intervention for at least 4 months. Most therapy sessions took place on a weekly basis in the general practices. By the 12-month follow-up, GP care in some cases did include referral to mental healthcare specialists.

MAIN OUTCOME MEASURES

The clinical outcomes included depressive symptoms, general psychiatric symptoms, social function and patient satisfaction. The economic outcomes included direct and indirect costs and quality of life. Assessments were carried out at baseline during face-to-face interviews as well as at 4 and 12 months in person or by post.

RESULTS

At 4 months, both psychological therapies had reduced depressive symptoms to a significantly greater extent than usual GP care. Patients in the psychological therapy groups exhibited mean scores on the Beck Depression Inventory that were 4-5 points lower than the mean score of patients in the usual GP care group, a difference that was also clinically significant. These differences did not generalize to other measures of outcome. There was no significant difference in outcome between the two psychological therapies when they were compared directly using all 260 patients randomised to a psychological therapy by either randomised allocation method. At 12 months, the patients in all three groups had improved to the same extent. The lack of a significant difference between the treatment groups at this point resulted from greater improvement of the patients in the GP care group between the 4- and 12-month follow-ups. At 4 months, patients in both psychological therapy groups were more satisfied with their treatment than those in the usual GP care group. However, by 12 months, patients who had received non-directive counselling were more satisfied than those in either of the other two groups. There were few differences in the baseline characteristics of patients who were randomised or expressed a treatment preference, and no differences in outcome between these patients. Similar outcomes were found for patients who chose either psychological therapy. Again, there were no significant differences between the two groups at 4 or 12 months. Patients who chose counselling were more satisfied with treatment than those who chose c

Randomised controlled trial of non-directive counselling, cognitive-behaviour therapy, and usual general practitioner care for patients with depression. I: clinical effectiveness

OBJECTIVE

To compare the clinical effectiveness of general practitioner care and two general practice based psychological therapies for depressed patients.

DESIGN

Prospective, controlled trial with randomised and patient preference allocation arms.

SETTING

General practices in London and greater Manchester.

PARTICIPANTS

464 of 627 patients presenting with depression or mixed anxiety and depression were suitable for inclusion.

INTERVENTIONS

Usual general practitioner care or up to 12 sessions of non-directive counselling or cognitive-behaviour therapy provided by therapists.

MAIN OUTCOME MEASURES

Beck depression inventory scores, other psychiatric symptoms, social functioning, and satisfaction with treatment measured at baseline and at 4 and 12 months.

RESULTS

197 patients were randomly assigned to treatment, 137 chose their treatment, and 130 were randomised only between the two psychological therapies. All groups improved significantly over time. At four months, patients randomised to non-directive counselling or cognitive-behaviour therapy improved more in terms of the Beck depression inventory (mean (SD) scores 12.9 (9.3) and 14.3 (10.8) respectively) than those randomised to usual general practitioner care (18.3 (12.4)). However, there was no significant difference between the two therapies. There were no significant differences between the three treatment groups at 12 months (Beck depression scores 11.8 (9.6), 11.4 (10.8), and 12.1 (10.3) for non-directive counselling, cognitive-behaviour therapy, and general practitioner care).

CONCLUSIONS

Psychological therapy was a more effective treatment for depression than usual general practitioner care in the short term, but after one year there was no difference in outcome.

Randomised controlled trial of non-directive counselling, cognitive-behaviour therapy, and usual general practitioner care for patients with depression. II: cost effectiveness

OBJECTIVE

To compare the cost effectiveness of general practitioner care and two general practice based psychological therapies for depressed patients.

DESIGN

Prospective, controlled trial with randomised and patient preference allocation arms.

SETTING

General practices in London and greater Manchester.

PARTICIPANTS

464 of 627 patients presenting with depression or mixed anxiety and depression were suitable for inclusion.

INTERVENTIONS

Usual general practitioner care or up to 12 sessions of non-directive counselling or cognitive-behaviour therapy provided by therapists.

MAIN OUTCOME MEASURES

Beck depression inventory scores, EuroQol measure of health related quality of life, direct treatment and non-treatment costs, and cost of lost production.

RESULTS

197 patients were randomly assigned to treatment, 137 chose their treatment, and 130 were randomised only between the two psychological therapies. At four months, both non-directive counselling and cognitive-behaviour therapy reduced depressive symptoms to a significantly greater extent than usual general practitioner care. There was no significant difference in outcome between treatments at 12 months. There were no significant differences in direct costs, production losses, or societal costs between the three treatments at either four or 12 months. Sensitivity analyses did not suggest that the results depended on particular assumptions in the statistical analysis.

CONCLUSIONS

Within the constraints of available power, the data suggest that both brief psychological therapies may be significantly more cost effective than usual care in the short term, as benefit was gained with no significant difference in cost. There are no significant differences between treatments in either outcomes or costs at 12 months.

Safety and immunogenicity of a paediatric presentation of an influenza vaccine

BACKGROUND

Flu vaccination in otherwise healthy infants and young children is important to prevent severe disease, as well as to control epidemic spread of influenza infection.

AIMS

To examine the safety and immunogenicity of a paediatric presentation of a purified, inactivated, triton split influenza vaccine.

METHODS

Two doses of the vaccine, provided in prefilled syringes of 0.25 ml, were administered, one month apart, to 67 children under 3 years of age.

RESULTS

Nine cases of immediate reaction to vaccination (macules/papules) were observed after the second injection only. During the study period, 9% of children experienced at least one delayed local reaction, and 28% of children presented at least one systemic reaction. Almost all reactions were mild and transient. Immunogenicity results surpassed the European Community recommendations for a 0.50 ml dose of vaccine in adults.

CONCLUSION

This paediatric formulation of inactivated flu vaccine appears safe and immunogenic in children from 6 months to 3 years of age; the convenient presentation in a prefilled syringe of 0.25 ml volume will facilitate administration of the dose recommended for young children.

Monoclonal antibodies

Monoclonal antibodies are essential tools for many molecular immunology investigations. In particular, when used in combination with techniques such as epitope mapping and molecular modelling, monoclonal antibodies enable the antigenic profiling and visualisation of macromolecular surfaces. In addition, monoclonal antibodies have become key components in a vast array of clinical laboratory diagnostic tests. Their wide application in detecting and identifying serum analytes, cell markers, and pathogenic agents has largely arisen through the exquisite specificity of these unique reagents. Furthermore, the continuous culture of hybridoma cells that produce these antibodies offers the potential of an unlimited supply of reagent. In essence, when compared with the rather limited supply of polyclonal antibody reagents, the feature of a continuous supply enables the standardisation of both the reagent and the assay technique. Clearly, polyclonal and monoclonal antibodies have their advantages and disadvantages in terms of generation, cost, and overall applications. Ultimately, monoclonal antibodies are only produced when necessary because their production is time consuming and frustrating, although greatly rewarding (at least most of the time!). This is especially apparent when a monoclonal antibody can be applied successfully in a routine pathology laboratory or can aid in the clinical diagnosis and treatment of patients. In this article, the generation and application of monoclonal antibodies are demystified to enable greater understanding and hopefully formulate novel ideas for clinicians and scientists alike.

Binding of porcine sperm plasma membrane proteins to sheep, hamster and mouse oocyte plasma membrane

Four porcine sperm plasma membrane proteins were previously identified as putative ligands for the oocyte plasma membrane. The present study examined the binding of these proteins and two additional porcine sperm membrane proteins to oocytes from sheep, mice and hamsters as a first step in assessing potential conservation of these putative sperm ligands across species and across mammalian orders. Plasma membrane vesicles were isolated from porcine sperm, solubilised, and the proteins separated by one-dimensional gel electrophoresis. The 7, 27, 39 and 62 kDa porcine sperm protein bands demonstrating predominant binding of the porcine oocyte plasma membrane on ligand blots, a 90 kDa protein band demonstrating minor binding, and a 97 kDa protein band that did not bind the oocyte plasma membrane probe were electroeluted. Proteins were biotinylated, and incubated with zona-free oocytes. Bound biotinylated protein was labelled with fluorescent avidin and the oocytes examined with a confocal microscope. The 7 kDa, 27 kDa and the 39 kDa proteins bound to the sheep oocytes but not to a majority of the hamster or mouse oocytes. The 62 kDa protein bound to sheep oocytes and mouse oocytes but not to a majority of the hamster oocytes. The 90 kDa protein bound to oocytes from all three species. The 97 kDa protein, which did not recognise the porcine oocyte probe on a Western ligand blot, did not bind to oocytes from any species and served as a negative control. These observations are consistent with significant conservation of molecule and function among species within the same mammalian order. Hence, one species may be a good model for other species from the same order. Only limited conservation of binding activity of porcine sperm plasma membrane proteins to rodent oocytes was observed, suggesting a greater divergence either in molecular structure or in function among species from different orders.

Structures of adenylosuccinate synthetase from Triticum aestivum and Arabidopsis thaliana

Catalyzing the first step in the de novo synthesis of adenylmonophosphate, adenylosuccinate synthetase (AdSS) is a known target for herbicides and antibiotics. We have purified and crystallized recombinant AdSS from Arabidopsis thaliana and Tritium aestivum, expressed in Escherichia coli. The structures of A. thaliana and T. aestivum AdSS in complex with GDP were solved at 2.9 A and 3.0 A resolution, respectively. Comparison with the known structures from E. coli reveals that the overall fold is very similar to that of the E. coli protein. The longer N terminus in the plant sequences is at the same place as the longer C terminus of the E. coli sequence in the 3D structure. The GDP-binding sites have one additional hydrogen-bonding partner, which is a plausible explanation for the lower K(m) value. Due to its special position, this partner may also enable GTP to initiate a conformational change, which was, in E. coli AdSS, exclusively activated by ligands at the IMP-binding site. The dimer interfaces show up to six hydrogen bonds and six salt-bridges more than in the E. coli structure, although the contact areas have approximately the same size.

Conducting randomized trials in general practice: methodological and practical issues

The evaluation of the outcome of health services technologies is a requirement for their efficient provision in clinical practice. The most reliable evidence for treatment efficacy comes from randomized trials. Randomized trials in general practice pose particular methodological and practical difficulties. In this paper, we discuss how best to plan and manage a clinical trial in this setting. We base our discussion on our experience of conducting randomized trials to evaluate the effectiveness of brief psychotherapy in general practice.

zfh-1, the Drosophila homologue of ZEB, is a transcriptional repressor that regulates somatic myogenesis

zfh-1 is a member of the zfh family of proteins, which all contain zinc finger and homeodomains. The roles and mechanisms of action of most family members are still unclear. However, we have shown previously that another member of the family, the vertebrate ZEB protein, is a transcriptional repressor that binds E box sequences and inhibits myotube formation in cell culture assays. zfh-1 is downregulated in Drosophila embryos prior to myogenesis. Embryos with zfh-1 loss-of-function mutation show alterations in the number and position of embryonic somatic muscles, suggesting that zfh-1 could have a regulatory role in myogenesis. However, nothing is known about the nature or mechanism of action of zfh-1. Here, we demonstrate that zfh-1 is a transcription factor that binds E box sequences and acts as an active transcriptional repressor. When zfh-1 expression was maintained in the embryo beyond its normal temporal pattern of downregulation, the differentiation of somatic but not visceral muscle was blocked. One potential target of zfh-1 in somatic myogenesis could be the myogenic factor mef2. mef2 is known to be regulated by the transcription factor twist, and we show here that zfh-1 binds to sites in the mef2 upstream regulatory region and inhibits twist transcriptional activation. Even though there is little sequence similarity in the repressor domains of ZEB and zfh-1, we present evidence that zfh-1 is the functional homologue of ZEB and that the role of these proteins in myogenesis is conserved from Drosophila to mammals.

Inhibition of protoporphyrinogen oxidase expression in Arabidopsis causes a lesion-mimic phenotype that induces systemic acquired resistance

We have used an antisense expression technology in Arabidopsis based on the yeast GAL4/UAS transactivation system (Guyer et al., Genetics, 1998; 149:633-639) to reduce levels of protoporphyrinogen IX oxidase (PPO), the last common enzyme of the biosynthesis of the haem group and chlorophyll. Plants expressing the antisense PPO gene presented growth alterations and their leaves showed necrotic lesions that appeared similar to lesions characteristic of the pathogen-induced hypersensitive reaction, and seen in the so-called lesion-mimic mutants. Plants expressing the antisense gene also had high endogenous salicylic acid levels, constitutive expression of the PR-1 gene, and were resistant to Peronospora parasitica, consistent with the activation of systemic acquired resistance (SAR). Treatment of wild-type plants with sublethal concentrations of herbicides that inhibit PPO also induced defence responses that conferred enhanced tolerance to P. parasitica. This effect was not observed in NahG and nim1 plants, which are compromised in their ability to activate SAR. These results demonstrate that genetic or chemical disruption of a metabolic pathway can lead to the induction of a set of defence responses including activation of SAR.

HPV 16 antibody prevalence in Jamaica and the United States reflects differences in cervical cancer rates

Human papillomavirus (HPV) is widely accepted as the primary etiologic agent in the development of cervical cancer. DNA of a particular HPV type, HPV 16, is found in about half of tumors tested. Inconsistent with this causal relationship, however, population-based studies of HPV DNA prevalence have often failed to find high rates of anogenital HPV infection in countries with high cervical cancer rates. To examine this issue, we used serology to compare HPV 16 exposure in healthy volunteer blood donors in the United States (n = 278) and similar subjects from a country with 3-fold higher cervical cancer rates, Jamaica (n = 257). Jamaican sexually transmitted disease (STD) patients (n = 831) were also studied to examine in detail the relation of HPV 16 antibodies with sexual history. Serology was conducted using an ELISA employing HPV 16 virus-like particles (VLPs). Age-adjusted seroprevalence rates were greatest among male (29%) and female (42%) STD patients, intermediate in male (19%) and female (24%) Jamaican blood donors and lowest among male (3%) and female (12%) U.S. blood donors. The higher seroprevalence in women was significant, and prevalence tended to increase with age. In multivariate logistic regression, controlling for age and gender, Jamaican blood donors were 4.2-fold (95% CI 2.4-7.2) and STD patients 8.1-fold (95% CI 5.0-13.2) more likely to have HPV 16 VLP antibodies than U.S. blood donors. Among STD patients, HPV 16 antibodies were associated with lifetime number of sex partners and years of sexual activity, as well as other factors. Our data suggest that HPV 16 VLP antibodies are strongly associated with sexual behavior. Moreover, exposure to HPV 16 appears to be much greater in Jamaica than in the United States, consistent with the high rate of cervical cancer in Jamaica.

Is HIV/STD control in Jamaica making a difference?

OBJECTIVE

To assess the impact of the comprehensive HIV/STD Control Program established in Jamaica since the late 1980s on the HIV/AIDS epidemic.

METHODS

AIDS case reports, HIV testing of blood donors, antenatal clinic attenders (ANC), food service workers, sexually transmitted disease (STD) clinic attenders, female prostitutes, homosexuals and other groups were used to monitor the HIV/AIDS epidemic. Primary and secondary syphilis and cases of congenital syphilis were also monitored. National knowledge, attitude and practice (KAP) surveys were conducted in 1988, 1989, 1992, 1994 and 1996.

RESULTS

The annual AIDS incidence rate in Jamaica increased only marginally in the past three years from 18.5 per 100000 population to 21.4 in 1997. HIV prevalence in the general population groups tested has been about 1% or less. Among those at high risk, HIV prevalence rates have risen to 6.3% (95% confidence interval 5.0-8.0) in STD clinic attenders, around 10% and 21% in female prostitutes in Kingston and Montego Bay respectively and approximately 30% among homosexuals. Syphilis rates and congenital syphilis cases have declined. The proportion of men aged 15-49 years reporting sex with a non-regular partner declined from 35% in 1994 to 26% in 1996 (P< 0.001). Women ever having used condoms increased from 51% in 1988 to 62.5% in 1992 and 73% in 1994 and 1996 (P< 0.001), while condom use with a non-regular partner increased from 37% in 1992 to 73% in 1996 (P= 0.006). Condom use among men was high over the period: around 81% had ever used condoms and 77% used them with non-regular partners. Gay men, inner-city adults and adolescents aged 12-14 years all reported increases in condom use while condom sales and distribution increased from around 2 million in 1985 to 10 million in 1995.

CONCLUSION

HIV/STD control measures appear to have slowed the HIV/AIDS epidemic in Jamaica, however a significant minority of persons continue to have unprotected sex in high risk situations.

Functional analysis of regulatory sequences controlling PR-1 gene expression in Arabidopsis

The Arabidopsis PR-1 gene is one of a suite of genes induced co-ordinately during the onset of systemic acquired resistance (SAR), a plant defense pathway triggered by pathogen infection or exogenous application of chemicals such as salicylic acid (SA) and 2,6-dichloroisonicotinic acid (INA). We have characterized cis-acting regulatory elements in the PR-1 promoter involved in INA induction using deletion analysis, linker-scanning mutagenesis, and in vivo footprinting. Compared to promoter fragments of 815 bp or longer (which show greater than 10-fold inducibility after INA treatment), induction of a 698 bp long promoter fragment is reduced by half and promoter fragments of 621 bp or shorter have lost all inducibility. Additionally, two 10-bp linker-scanning mutations centered at 640 bp and 610 bp upstream from the transcription initiation site are each sufficient to abolish chemical inducibility of a GUS reporter fusion. The -640 linker-scanning mutation encompasses a region highly homologous to recognition sites for transcription factors of the basic leucine zipper class, while the -610 linker-scanning mutation contains a sequence similar to a consensus recognition site for the transcription factor NF-kappa B. Furthermore, several inducible in vivo footprints located at or nearby these motifs demonstrate significant and highly reproducible changes in DNA accessibility following SAR induction. This in vivo signature of protein-DNA interactions after INA induction is tightly correlated with the functionally important regions of the promoter identified by mutation analysis.

The Caenorhabditis elegans gene T23G5.5 encodes an antidepressant- and cocaine-sensitive dopamine transporter

A small subset of neurons in the nematode Caenorhabditis elegans utilizes the catecholamine dopamine (DA) as a neurotransmitter to control or modulate movement and egg-laying. Disruption of DA-mediated behaviors represents a potentially powerful strategy to identify genes that are likely to participate in dopaminergic systems in man. In vertebrates, extracellular DA is inactivated by presynaptic DA transport proteins (DATs) that are also major targets of addictive agents, including amphetamines and cocaine. We used oligonucleotides derived from the C. elegans genomic locus T23G5.5 to isolate and characterize T23G5.5 cDNAs. Our studies predict that mRNAs from this locus encode a 615-amino-acid polypeptide with twelve stretches of hydrophobicity suitable for transmembrane domains, similar to that found in vertebrate catecholamine transporters. The inferred translation product bears highest identity (43-47%) to catecholamine (DA, norepinephrine, epinephrine) transporters within the GAT1/NET gene family and possesses conserved residues implicated in amine substrate recognition. Consistent with these findings, HeLa cells transfected with the C. elegans cDNA exhibit saturable and high affinity DA transport (Km = 1.2 microM) that is dependent on extracellular Na+ and Cl- and blocked by inhibitors of mammalian catecholamine transporters, including norepinephrine transporter- and DAT-selective antagonists, tricyclic antidepressants, and the nonselective amine transporter antagonists cocaine and D-amphetamine. These studies validate the T23G5.5 locus as encoding a functional catecholamine transporter, providing important comparative sequence information for catecholamine transporter structure/function studies and a path to identify regulators of dopaminergic signaling via genetic or pharmacologic manipulation of C. elegans cDNA in vivo.

Genotoxicity in workers exposed to methyl bromide

To address the genotoxicity of in vivo methyl bromide (CAS 74-83-9) exposure in humans, we collected blood and oropharyngeal cells as part of a cross-sectional morbidity study of methyl bromide-exposed fumigation workers and their referents. Micronuclei were measured in lymphocytes and oropharyngeal cells, and hypoxanthine-guanine phosphoribosyl transferase gene (hprt) mutations were measured in lymphocytes. A total of 32 workers and 28 referents provided specimens. Among current non-smokers, mean hprt variant frequencies (Vfs) were found to be elevated among workers compared to referents (geometric mean: workers=4.49x10(-6), referents=2.96x10-(6); two-sided p=0.22); this difference was more pronounced among workers with 4 h or more of recent methyl bromide exposure compared to referents (geometric mean: workers=6.56x10(-6), referents=2.96x10(-6); two-sided p=0.06). Mean oropharyngeal cell micronuclei were higher among workers compared to referents (mean: workers=2.00, referents=1.31; two-sided p=0.08); the results were similar when workers with 4 h or more of recent methyl bromide exposure were compared to referents (mean: workers=2.07, referents=1.31; two-sided p=0.13). No consistent differences between workers and referents were observed for frequencies of kinetochore-negative lymphocyte micronuclei, or kinetochore-positive lymphocyte micronuclei. The study was limited by a sample size sufficient only for detecting relatively large differences, absence of a reliable method to measure the intensity of workplace methyl bromide exposures, and relatively infrequent methyl bromide exposure (e.g., the median length of exposure to methyl bromide during the 2 weeks preceding the survey was 4 h). In conclusion, our findings provide some evidence that methyl bromide exposure may be associated with genotoxic effects in lymphocytes and oropharyngeal cells. Further study on the genotoxicity of methyl bromide exposure in humans is warranted.

Mortality of industrial workers exposed to acrylonitrile

OBJECTIVES

This study was designed to evaluate the relationship between occupational exposure to acrylonitrile and cancer mortality.

MATERIALS AND METHODS

Workers (18079 white men, 4293 white women, 2191 nonwhite men, and 897 nonwhite women) employed in acrylonitrile production or use in the 1950s through 1983 were followed through 1989 for vital status and cause of death. Exposure-response relationships were evaluated from quantitative estimates of historical exposures. Tobacco use was determined for a sample of workers to assess potential confounding. Mortality rates between the exposed and unexposed workers in the cohort were compared using the Poisson regression.

RESULTS

Analyses by cumulative, average, peak, intensity, duration, and lagged exposure revealed no elevated risk of cancers of the stomach, brain, breast, prostate or lymphatic and hematopoietic systems. Mortality from lung cancer was elevated for the highest quintile of cumulative exposure. When the decile categories were used, the relative risk did not continue to increase at higher levels. Adjustment for cigarette use reduced the risk for lung cancer only slightly. Separate analyses for wage and salaried workers, long-term and short-term workers, fiber and nonfiber plants, and individual plants revealed no clear exposure-response patterns.

CONCLUSIONS

The results indicate that exposure to acrylonitrile at the levels studied is not associated with an increased relative risk for most cancers of a priori interest. The excess of lung cancer in the highest quintile of cumulative exposure may indicate carcinogenic activity at the highest levels of exposure, but analyses of exposure-response do not provide strong or consistent evidence for a causal association.

Activation of latent transgenes in Arabidopsis using a hybrid transcription factor

A hybrid transcription factor comprising a fusion of the DNA-binding domain of Saccharomyces cerevisiae GAL4 and the transcription activation domain of maize C1 was expressed in stably transformed Arabidopsis. Additional transgenic lines were created containing test genes controlled by a synthetic promoter consisting of concatemeric copies of the cis-acting site recognized by GAL4 (UASG) fused to a minimal promoter. The GAL4/C1 effector line was crossed to two lines containing a synthetic promoter/GUS fusion. Both histochemical staining and GUS activity assays indicate strong activation of GUS expression was achieved only after crossing. The GAL4/C1 effector line was also crossed to 15 lines containing a synthetic promoter/antisense adenylosuccinate synthetase gene. Severely retarded growth, and in some cases lethality, was observed in 40% of the F1 lines. This system of activation by crossing is generally useful for activating expression of test transgenes.