Irinotecan, cisplatin and mitomycin in inoperable gastro-oesophageal and pancreatic cancers - a new active regimen

Irinotecan, mitomycin and cisplatin all demonstrate activity in gastro-oesophageal cancers. This novel combination was administered to outpatients with previously untreated inoperable gastro-oesophageal or pancreatic cancer, in a 28-day cycle. A total of 26 out of 31 patients with gastro-oesophageal cancer and 12 out of 14 patients with pancreatic cancer have been treated with this combination, and were evaluable for response. The overall response rates for patients with gastro-oesophageal cancer was 42%, with a median survival of 9.5 months. In patients with pancreatic cancer, the overall response rate was 42% with a median survival of 8 months. There was a statistically significant increase in survival between those patients who achieved a stable disease response and those who achieved either a partial response or complete response. The toxicity profiles for both cancers were virtually identical. There were five treatment-related deaths, and a high admission rate (42%). Thus irinotecan, mitomycin and cisplatin is a new combination with activity in inoperable upper gastro-oesophageal cancers, but with a high toxicity profile. Future developments include reducing the dose of irinotecan and number of cycles of therapy to four.

Genome sequence of the plant pathogen and biotechnology agent Agrobacterium tumefaciens C58

Agrobacterium tumefaciens is a plant pathogen capable of transferring a defined segment of DNA to a host plant, generating a gall tumor. Replacing the transferred tumor-inducing genes with exogenous DNA allows the introduction of any desired gene into the plant. Thus, A. tumefaciens has been critical for the development of modern plant genetics and agricultural biotechnology. Here we describe the genome of A. tumefaciens strain C58, which has an unusual structure consisting of one circular and one linear chromosome. We discuss genome architecture and evolution and additional genes potentially involved in virulence and metabolic parasitism of host plants.

State variation in retail promotions and advertising for Marlboro cigarettes

BACKGROUND

There is some evidence that tobacco companies marketing efforts undermine the effects of comprehensive tobacco control programmes.

OBJECTIVE

To determine whether point-of-purchase advertising and promotions are more pervasive in states where comprehensive tobacco control programmes are underway.

DESIGN

Cross sectional survey using 1996 data, with merged records of the existence of local tobacco advertising restrictions.

PARTICIPANTS AND SETTING

581 tobacco retail stores located in close proximity to high schools in mainland USA.

MAIN OUTCOME MEASURES

Existence of gift-with-purchase, number of interior advertisements, and exterior store advertisements for Marlboro cigarettes.

RESULTS

After controlling for store type and existence of advertising restrictions, offer of a gift-with-purchase for Marlboro cigarettes was significantly more likely in states with comprehensive tobacco control programmes than those without programmes (odds ratio 2.59, 95% confidence interval 1.57 to 4.26). Although not significant, results show an increase in the number of interior and exterior store advertisements for stores located in states with a comprehensive tobacco control programme than those in other states.

CONCLUSION

Results suggest some point-of-purchase tobacco promotions and advertising are more pervasive in states with comprehensive tobacco control programmes. These efforts are likely to act against the objectives of programmes and need to be accounted for in programme evaluations.

Long-term outcome of patients surviving for more than ten years following treatment for acute leukaemia

Between 1972 and 1988, 832 consecutive patients were treated for acute leukaemia at St. Bartholomew's Hospital; a retrospective analysis has been conducted to determine the clinical course and outcome for 101 who have survived > or = 10 years following treatment. At a median follow-up of 16 years (range 10-28 years), 86 patients (86 out of 834 total, 11%) were still alive. Long-term follow-up of patients who have survived > or = 10 years following treatment for acute leukaemia revealed that most patients were in normal health, although a significant number of complications had occurred.

Induced sputum eosinophils and neutrophils and bronchiectasis severity in allergic bronchopulmonary aspergillosis

Allergic bronchopulmonary aspergillosis (ABPA) is a hypersensitivity reaction to the fungus Aspergillus fumigatus that may progress to bronchiectasis. The aim of the present study was to characterize airway inflammation in patients with clinically stable ABPA and asthma, and to correlate this with bronchiectasis severity. Subjects with ABPA and central bronchiectasis (ABPA-CB; n=16) and ABPA with serological evidence alone (ABPA-S; n=10) were studied. Comparison groups were A. fumigatus-sensitized asthma (n=19), non-A. fumigatus-sensitized asthma (n=15) and healthy controls (n=8). Hypertonic saline challenge, sputum induction and high-resolution computed tomography (HRCT) of the chest were performed. Sputum eosinophil numbers were markedly elevated in ABPA-CB (median 8.4%) compared to ABPA-S (2.4%), A. fumigatus-sensitized asthma (1.8%), asthma (1.8%) and controls (0.3%) (p<0.01); sputum eosinophil cationic protein levels were higher in ABPA-CB (median 13,706 ng.mL(-1)), compared to ABPA-S (1,633.5 ng.mL(-1)), A. fumigatus-sensitized asthma (1,550.7 ng.mL(-1)), asthma (309.2 ng.mL(-1)), and controls (110 ng.mL(-1)) (p<0.001). ABPA-CB also showed increased sputum neutrophil number (median 60.3%) compared to the other groups (controls 29.3%) (p=0.01). The severity of bronchiectasis on HRCT correlated with sputum neutrophil (r=0.6) and eosinophil number (r=0.5) but not serum immunoglobulin-E levels. In conclusion, clinically stable allergic bronchopulmonary aspergillosis with bronchiectasis is characterized by an intense heterogenous inflammatory infiltrate consisting of eosinophils and neutrophils, which correlates closely with the severity of bronchiectasis on high-resolution computed tomography. Sputum analysis may be useful in monitoring the course of allergic bronchopulmonary aspergillosis.

Testosterone: its role in development of prostate cancer and potential risk from use as hormone replacement therapy

Evidence from studies in patients with prostate cancer of intermittent hormone therapy combined with results from rechallenge of hormone resistant patients with testosterone demonstrate that the majority of prostate cancers retain a similar degree of dependence on male sex hormone milieu as normal prostate cells. Yet there has so far been no conclusive evidence, despite 34 studies, that levels of circulating testosterone in individuals developing prostate cancer are higher than in controls. The aim of this article was to critically evaluate this evidence and seek clues to other mechanisms whereby sex hormones could influence the development of prostate cancer. Additionally, epidemiological data were examined to investigate the interplay between sex hormone levels and environmental factors to help understand the development of prostate cancer and identify a safe way to provide hormone replacement therapy (HRT). Three overviews provide similar evidence that there is no significant difference in mean testosterone levels between patients and controls. However in the most recent review of studies, though there was no difference in means between cases and controls, there was a significant risk (adjusted odds ratio 2.34) for individuals identified by comparing incidence of prostate cancer in men in the upper and lower quartile of testosterone level. This report, taken with epidemiological data demonstrating that prostate cancer risk is increased by early age of onset of sexual activity and multiple nonspecific sexually transmitted diseases (STDs), has led to the hypothesis that the link between sex hormones and prostate cancer is indirect. Those individuals with high testosterone levels were more at risk of acquisition of multiple nonspecific STDs. This promotes transformation of prostate cells and damage to Leydig cells in the testis leading to there being no difference in testosterone compared with controls by the time the tumour is diagnosed. Because of the observed relationship between testosterone and prostate cancer development there has been anxiety about marketing HRT for men. Two observations support the view that the prostate cancer risks from use of testosterone hormone replacement may not be as great as first feared. Firstly, prostate cancers arising in men with low serum testosterone levels are more malignant and frequently nonresponsive to hormones. Secondly, breast cancers diagnosed in women on HRT though increased in number are less malignant possibly because of enhanced sensitivity to hormone therapy, and the situation may prove to be analogous with prostate cancer and testosterone replacement.

Expert opinions on optimal enforcement of minimum purchase age laws for tobacco

A questionnaire on how youth access laws should be enforced was sent to 20 experts who had administered and/or evaluated a youth access enforcement program. Respondents agreed on the need for a high level of retail compliance, checkers representative of the community, checks at least twice per year, a graduated penalty structure with license revocation, and bans on self-service and vending machines. Respondents indicated the need for research on the effects of ID use, frequency of checks, penalty structures, and the effects on smoking rates of youth access policies alone and in conjunction with other tobacco control policies.

Metabolic engineering of Arabidopsis and Brassica for poly(3-hydroxybutyrate-co-3-hydroxyvalerate) copolymer production

Poly(hydroxyalkanoates) are natural polymers with thermoplastic properties. One polymer of this class with commercial applicability, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) can be produced by bacterial fermentation, but the process is not economically competitive with polymer production from petrochemicals. Poly(hydroxyalkanoate) production in green plants promises much lower costs, but producing copolymer with the appropriate monomer composition is problematic. In this study, we have engineered Arabidopsis and Brassica to produce PHBV in leaves and seeds, respectively, by redirecting the metabolic flow of intermediates from fatty acid and amino acid biosynthesis. We present a pathway for the biosynthesis of PHBV in plant plastids, and also report copolymer production, metabolic intermediate analyses, and pathway dynamics.

Poly(beta-hydroxybutyrate) production in oilseed leukoplasts of brassica napus

Polyhydroxyalkanoates (PHAs) comprise a class of biodegradable polymers which offer an environmentally sustainable alternative to petroleum-based plastics. Production of PHAs in plants is attractive since current fermentation technology is prohibitively expensive. The PHA homopolymer poly(beta-hydroxybutyrate) (PHB) has previously been produced in leaves of Arabidopsis thaliana (Nawrath et al., 1994, Proc Natl Acad Sci USA 91: 12760-12764). However, Brassica napus oilseed may provide a better system for PHB production because acetyl-CoA, the substrate required in the first step of PHB biosynthesis, is prevalent during fatty acid biosynthesis. Three enzymatic activities are needed to synthesize PHB: a beta-ketothiolase, an acetoacetyl-CoA reductase and a PHB synthase. Genes from the bacterium Ralstonia eutropha encoding these enzymes were independently engineered behind the seed-specific Lesquerella fendleri oleate 12-hydroxylase promoter in a modular fashion. The gene cassettes were sequentially transferred into a single, multi-gene vector which was used to transform B. napus. Poly(beta-hydroxybutyrate) accumulated in leukoplasts to levels as high as 7.7% fresh seed weight of mature seeds. Electron-microscopy analyses indicated that leukoplasts from these plants were distorted, yet intact, and appeared to expand in response to polymer accumulation.

The "Let's Get Alarmed!" initiative: a smoke alarm giveaway programme

OBJECTIVES

To reduce fires and fire related injuries by increasing the prevalence of functioning smoke alarms in high risk households.

SETTING

The programme was delivered in an inner London area with above average material deprivation and below average smoke alarm ownership. The target population included low income and rental households and households with elderly persons or young children.

METHODS

Forty wards, averaging 4000 households each, were randomised to intervention or control status. Free smoke alarms and fire safety information were distributed in intervention wards by community groups and workers as part of routine activities and by paid workers who visited target neighbourhoods. Recipients provided data on household age distribution and housing tenure. Programme costs were documented from a societal perspective. Data are being collected on smoke alarm ownership and function, and on fires and related injuries and their costs.

RESULTS

Community and paid workers distributed 20,050 smoke alarms, potentially sufficient to increase smoke alarm ownership by 50% in intervention wards. Compared with the total study population, recipients included greater proportions of low income and rental households and households including children under 5 years or adults aged 65 and older. Total programme costs were 145,087 Pounds.

CONCLUSIONS

It is possible to implement a large scale smoke alarm giveaway programme targeted to high risk households in a densely populated, multicultural, materially deprived community. The programme's effects on the prevalence of installed and functioning alarms and the incidence of fires and fire related injuries, and its cost effectiveness, are being evaluated as a randomized controlled trial.

PHA production, from bacteria to plants

The genes encoding the polyhydroxyalkanoate (PHA) biosynthetic pathway in Ralstonia eutropha (3-ketothiolase, phaA or bktB; acetoacetyl-CoA reductase, phaB; and PHA synthase, phaC) were engineered for plant plastid targeting and expressed using leaf (e35S) or seed-specific (7s or lesquerella hydroxylase) promoters in Arabidopsis and Brassica. PHA yields in homozygous transformants were 12-13% of the dry mass in homozygous Arabidopsis plants and approximately 7% of the seed weight in seeds from heterozygous canola plants. When a threonine deaminase was expressed in addition to bktB, phaB and phaC, a copolyester of 3-hydroxybutyrate and 3-hydroxyvalerate was produced in both Arabidopsis and Brassica.

Acute promyelocytic leukaemia: a retrospective analysis of patients treated at St. Bartholomew's Hospital 1969-1995

Seventy-two patients with acute promyelocytic leukemia (APML) were treated at St.Bartholomew's Hospital (SBH) over a 25-year period. Improvements in supportive care and the use of more intensive chemotherapy have led to an increase in the complete remission rate from 14 to 58%. Similarly, the median survival has increased from 3 weeks to 2 years; the median duration of remission, which was 7 months in 1974, has not yet been reached. There was also a significant difference in survival from first recurrence, compared with that of patients with other subtypes of acute myeloid leukemia. RT-PCR analysis on bone marrow samples from 14 patients confirmed the presence of the PML/RARA fusion; 13 of the 14 patients achieved 'molecular remission' after therapy. The one patient who remained persistently positive experienced recurrence within 4 months. In seven of the eight patients in whom the disease recurred, the translocation was identified by RT-PCR at the time of relapse, whilst in one patient it was noted 4 months prior to morphological recurrence. These results illustrate the improvement in prognosis that occurred over a 25-year period in patients with APML treated at a single centre.

Hepatic plasmacytomas: case report and review of imaging features

Extramedullary plasmacytomas are uncommon and have a better prognosis than disseminated myeloma. We describe the second case of hepatic plasmacytomas (multiple) following a solitary bone plasmacytoma. The imaging characteristics of the few reported cases of these rare hepatic tumours are compared. The value of ultrasound in the assessment of liver lesions is emphasized.

Aqueous release and purification of poly(beta-hydroxybutyrate) from Escherichia coli

The poly(beta-hydroxybutyrate) (PHB) biosynthetic genes of Ralstonia eutropha that are organized in a single operon (phaCAB) have been cloned in Escherichia coli, where the expression of the genes in the wild-type pha operon from plasmid pTZ18U-PHB leads to the formation of 50-80% PHB/celldry mass when the cells are grown in Luria-Bertani medium supplemented with 1% glucose (w/v). In combination with the phaCAB genes, expression of cloned lysis gene E of bacteriophage PhiX174 from plasmid pSH2 has been used to release PHB granules produced in E. coli. It was shown that small PHB granules in a semiliquid stage are squeezed out of the cells through the E-lysis tunnel structure which is characterized by a small opening in the envelope with borders of fused inner and outer membranes. All envelope components remain intact after E-lysis and can be removed from the mixture of released PHB granules by density gradient centrifugation. In addition, a modified E-lysis procedure is described which enables the release of PHB from cell pellets in pure water or low ionic strength buffer. PHB granules in aqueous solution can be aggregated by divalent cations. Addition of glassmilk speeds up the agglomeration of PHB granules and binding to glass beads can either be used for collection or further purification of PHB in aqueous solutions.

Effects of purified SeqA protein on oriC-dependent DNA replication in vitro

In vivo studies suggest that the Escherichia coli SeqA protein modulates replication initiation in two ways: by delaying initiation and by sequestering newly replicated origins from undergoing re-replication. As a first approach towards understanding the biochemical bases for these effects, we have examined the effects of purified SeqA protein on replication reactions performed in vitro on an oriC plasmid. Our results demonstrate that SeqA directly affects the biochemical events occurring at oriC. First, SeqA inhibits formation of the pre-priming complex. Secondly, SeqA can inhibit replication from an established pre-priming complex, without disrupting the complex. Thirdly, SeqA alters the dependence of the replication system on DnaA protein concentration, stimulating replication at low concentrations of DnaA. Our data suggest that SeqA participates in the assembly of initiation-competent complexes at oriC and, at a later stage, influences the behaviour of these complexes.

Lithium and clozapine-induced neutropenia/agranulocytosis

Lithium administration was used in a patient with a clozapine-induced neutropenia and in another with complete agranulocytosis to assess whether lithium could stimulate neutrophil production. In both cases, following lithium administration, the neutrophil count was increased to the normal range within 6 days. In the patient who had presented a neutropenia, clozapine treatment was then reinstated in the presence of lithium and continued without the neutrophil count dropping into the yellow-alert range thereafter.

Multiple beta-ketothiolases mediate poly(beta-hydroxyalkanoate) copolymer synthesis in Ralstonia eutropha

Polyhydroxyalkanoates (PHAs) are a class of carbon and energy storage polymers produced by numerous bacteria in response to environmental limitation. The type of polymer produced depends on the carbon sources available, the flexibility of the organism's intermediary metabolism, and the substrate specificity of the PHA biosynthetic enzymes. Ralstonia eutropha produces both the homopolymer poly-beta-hydroxybutyrate (PHB) and, when provided with the appropriate substrate, the copolymer poly(beta-hydroxybutyrate-co-beta-hydroxyvalerate) (PHBV). A required step in production of the hydroxyvalerate moiety of PHBV is the condensation of acetyl coenzyme A (acetyl-CoA) and propionyl-CoA to form beta-ketovaleryl-CoA. This activity has generally been attributed to the beta-ketothiolase encoded by R. eutropha phbA. However, we have determined that PhbA does not significantly contribute to catalyzing this condensation reaction. Here we report the cloning and genetic analysis of bktB, which encodes a beta-ketothiolase from R. eutropha that is capable of forming beta-ketovaleryl-CoA. Genetic analyses determined that BktB is the primary condensation enzyme leading to production of beta-hydroxyvalerate derived from propionyl-CoA. We also report an additional beta-ketothiolase, designated BktC, that probably serves as a secondary route toward beta-hydroxyvalerate production.