Eligibility and response guidelines for phase II clinical trials in androgen-independent prostate cancer: recommendations from the Prostate-Specific Antigen Working Group

PURPOSE

Prostate-specific antigen (PSA) is a glycoprotein that is found almost exclusively in normal and neoplastic prostate cells. For patients with metastatic disease, changes in PSA will often antedate changes in bone scan. Furthermore, many but not all investigators have observed an association between a decline in PSA levels of 50% or greater and survival. Since the majority of phase II clinical trials for patients with androgen-independent prostate cancer (AIPC) have used PSA as a marker, we believed it was important for investigators to agree on definitions and values for a minimum set of parameters for eligibility and PSA declines and to develop a common approach to outcome analysis and reporting. We held a consensus conference with 26 leading investigators in the field of AIPC to define these parameters.

RESULT

We defined four patient groups: (1) progressive measurable disease, (2) progressive bone metastasis, (3) stable metastases and a rising PSA, and (4) rising PSA and no other evidence of metastatic disease. The purpose of determining the number of patients whose PSA level drops in a phase II trial of AIPC is to guide the selection of agents for further testing and phase III trials. We propose that investigators report at a minimum a PSA decline of at least 50% and this must be confirmed by a second PSA value 4 or more weeks later. Patients may not demonstrate clinical or radiographic evidence of disease progression during this time period. Some investigators may want to report additional measures of PSA changes (ie, 75% decline, 90% decline). Response duration and the time to PSA progression may also be important clinical end point.

CONCLUSION

Through this consensus conference, we believe we have developed practical guidelines for using PSA as a measurement of outcome. Furthermore, the use of common standards is important as we determine which agents should progress to randomized trials which will use survival as an end point.

Evidence for autolysin-mediated primary attachment of Staphylococcus epidermidis to a polystyrene surface

Biofilm formation on a polymer surface which involves initial attachment and accumulation in multilayered cell clusters (intercellular adhesion) is proposed to be the major pathogenicity factor in Staphylococcus epidermidis foreign-body-associated infections. We have characterized two distinct classes of biofilm-negative Tn917 mutants in S. epidermidis affected in initial attachment (class A) or intercellular adhesion (class B). mut1 (class A mutant) lacks five surface-associated proteins with molecular masses of 120, 60, 52, 45 and 38 kDa and could be complemented by transformation with a 16.4 kb wild-type DNA fragment. The complemented mutant was able to attach to a polystyrene surface, to form a biofilm, and produced all of the proteins missing from mut1. Subcloning experiments revealed that the 60 kDa protein is sufficient for initial attachment. Immunofluorescence microscopy using an antiserum raised against the 60 kDa protein showed that this protein is located at the cell surface. DNA-sequence analysis of the complementing region revealed a single open reading frame which consists of 4005 nucleotides and encodes a deduced protein of 1335 amino acids with a predicted molecular mass of 148kDa. The amino acid sequence exhibits a high similarity (61% identical amino acids) to the atl gene product of Staphylococcus aureus, which represents the major autolysin; therefore the open reading frame was designated atlE. By analogy with the S. aureus autolysin, AtlE is composed of two bacteriolytically active domains, a 60 kDa amidase and a 52 kDa glucosaminidase domain, generated by proteolytic processing. The 120 kDa protein missing from mut1 presumably represents the unprocessed amidase and glucosaminidase domain after proteolytic cleavage of the signal- and propeptide. The 45 and 38kDa proteins are probably the degradation products of the 60 and 52 kDa proteins, respectively. Additionally, AtlE was found to exhibit vitronectin-binding activity, indicating that AtlE plays a role in binding of the cells not only to a naked polystyrene surface during early stages of adherence, but also to plasma protein-coated polymer surfaces during later stages of adherence. Our findings provide evidence for a new function of an autolysin (AtlE) in mediating the attachment of bacterial cells to a polymer surface, representing the prerequisite for biofilm formation.

Insulinotropic glucagon-like peptide 1 agonists stimulate expression of homeodomain protein IDX-1 and increase islet size in mouse pancreas

Diabetes is caused by a failure of the pancreas to produce insulin in amounts sufficient to meet the body's needs. A hallmark of diabetes is an absolute (type 1) or relative (type 2) reduction in the mass of pancreatic beta-cells that produce insulin. Mature beta-cells have a lifespan of approximately 48-56 days (rat) and are replaced by the replication of preexisting beta-cells and by the differentiation and proliferation of new beta-cells (neogenesis) derived from the pancreatic ducts. Here, we show that the insulinotropic hormone glucagon-like peptide (GLP)-1, which is produced by the intestine, enhances the pancreatic expression of the homeodomain transcription factor IDX-1 that is critical for pancreas development and the transcriptional regulation of the insulin gene. Concomitantly, GLP-1 administered to diabetic mice stimulates insulin secretion and effectively lowers their blood sugar levels. GLP-1 also enhances beta-cell neogenesis and islet size. Thus, in addition to stimulating insulin secretion, GLP-1 stimulates the expression of the transcription factor IDX-1 while stimulating beta-cell neogenesis and may thereby be an effective treatment for diabetes.

Management of patients with advanced prostate cancer: recommendations of the St Gallen Advanced Prostate Cancer Consensus Conference (APCCC) 2015

The first St Gallen Advanced Prostate Cancer Consensus Conference (APCCC) Expert Panel identified and reviewed the available evidence for the ten most important areas of controversy in advanced prostate cancer (APC) management. The successful registration of several drugs for castration-resistant prostate cancer and the recent studies of chemo-hormonal therapy in men with castration-naïve prostate cancer have led to considerable uncertainty as to the best treatment choices, sequence of treatment options and appropriate patient selection. Management recommendations based on expert opinion, and not based on a critical review of the available evidence, are presented. The various recommendations carried differing degrees of support, as reflected in the wording of the article text and in the detailed voting results recorded in supplementary Material, available at Annals of Oncology online. Detailed decisions on treatment as always will involve consideration of disease extent and location, prior treatments, host factors, patient preferences as well as logistical and economic constraints. Inclusion of men with APC in clinical trials should be encouraged.

A 140-kilodalton extracellular protein is essential for the accumulation of Staphylococcus epidermidis strains on surfaces

Two distinct pathogenic mechanisms, adhesion to polymer surfaces and subsequent accumulation of sessile bacterial cells, are considered important pathogenic steps in foreign body infections caused by Staphylococcus epidermidis. By using mitomycin mutagenesis, we have recently generated a mutant, strain M7, from S. epidermidis RP62A which is unaffected in adhesion but deficient in accumulation on glass or polystyrene surfaces and lacks a 115-kDa extracellular protein (designated the 140-kDa antigen; F. Schumacher-Perdreau, C. Heilmann, G. Peters, F. Götz, and G. Pulverer, FEMS Microbiol. Lett. 117:71-78, 1994). To evaluate the role of this protein in accumulation, we harvested extracellular proteins from S. epidermidis RP62A grown on dialysis membranes placed over chemically defined medium, purified the protein by using ion-exchange chromatography, determined its N-terminal amino acid sequence, and raised antiserum in rabbits. The antibody recognized only a single band in a Western immunoblot of the crude extracellular extract. With the microtiter biofilm test, antiserum at a dilution of < or =1:1,000 blocked accumulation of RP62A up to 98% whereas preimmune serum did not. The 140-kDa antigen was found only in extracellular products from bacteria grown under sessile conditions. Of 58 coagulase-negative clinical isolates, 32 strains were 140-kDa antigen positive and produced significantly larger amounts of biofilm than the 26 strains that were 140-kDa antigen negative. The 140-kDa protein appears to be biochemically and functionally unrelated to any previously described factors associated with biofilm formation. Thus, the 140-kDa antigen, referred to as accumulation-associated protein, may be a factor essential in S. epidermidis accumulation and, due to its immunogenicity, may allow the development of novel immunotherapeutic strategies for prevention of foreign body infection.

Sphincter-sparing treatment for distal rectal adenocarcinoma

BACKGROUND

Studies suggest that the anal sphincter can be preserved in some patients with distal rectal adenocarcinoma (DRA), but this has not been validated in any prospective multi-institutional trial.

METHODS

To test the hypothesis that the anal sphincter can be preserved in some patients with DRA, the Cancer and Leukemia Group B and collaborators reviewed 177 patients who had T1/T2 adenocarcinomas < or = 4 cm in diameter, which encompassed < or = 40% of bowel wall circumference, and were < or = 10 cm from the dentate line. Of the 177 patients, 59 patients who were eligible for the study had T1 adenocarcinomas and received no further treatment; 51 eligible T2 patients received external beam irradiation (5400 cGY/30 fractions 5 days/week) and 5-fluorouracil (500 mg/m2 IV d1-3, d29-31) after local excision.

RESULTS

At 48 months median follow-up, 6-year survival and failure-free survival rates of the eligible patients are 85% and 78% respectively. Three patients died of unrelated disease. Two patients were treated for second primary colorectal tumors; both remain disease free (NED). Another eight patients died of disease, four with distant recurrence only. One T1 patient is alive with distant disease. Two T1 and seven T2 patients experienced isolated local recurrences; all underwent salvage abdominoperineal resection (APR). After APR, one T1 and four of seven T2 patients were NED at the time of last visit (2-7 years). One T1 patient died of local and distant disease. Three of seven T2 patients died with distant disease.

CONCLUSIONS

We conclude that sphincter preservation can be achieved with excellent cancer control without initial sacrifice of anal function in most patients. After local recurrence, salvage resection appears effective, but longer follow-up time of local and distant disease-free survival is advised before extrapolation to patients with T3 primaries.

Epigenomic alterations and gene expression profiles in respiratory epithelia exposed to cigarette smoke condensate

Limited information is available regarding epigenomic events mediating initiation and progression of tobacco-induced lung cancers. In this study, we established an in vitro system to examine epigenomic effects of cigarette smoke in respiratory epithelia. Normal human small airway epithelial cells and cdk-4/hTERT-immortalized human bronchial epithelial cells (HBEC) were cultured in normal media with or without cigarette smoke condensate (CSC) for up to 9 months under potentially relevant exposure conditions. Western blot analysis showed that CSC mediated dose- and time-dependent diminution of H4K16Ac and H4K20Me3, while increasing relative levels of H3K27Me3; these histone alterations coincided with decreased DNA methyltransferase 1 (DNMT1) and increased DNMT3b expression. Pyrosequencing and quantitative RT-PCR experiments revealed time-dependent hypomethylation of D4Z4, NBL2, and LINE-1 repetitive DNA sequences; up-regulation of H19, IGF2, MAGE-A1, and MAGE-A3; activation of Wnt signaling; and hypermethylation of tumor suppressor genes such as RASSF1A and RAR-beta, which are frequently silenced in human lung cancers. Array-based DNA methylation profiling identified additional novel DNA methylation targets in soft-agar clones derived from CSC-exposed HBEC; a CSC gene expression signature was also identified in these cells. Progressive genomic hypomethylation and locoregional DNA hypermethylation induced by CSC coincided with a dramatic increase in soft-agar clonogenicity. Collectively, these data indicate that cigarette smoke induces 'cancer-associated' epigenomic alterations in cultured respiratory epithelia. This in vitro model may prove useful for delineating early epigenetic mechanisms regulating gene expression during pulmonary carcinogenesis.

Different hepatitis B virus genotypes are associated with different mutations in the core promoter and precore regions during hepatitis B e antigen seroconversion

Mutations in the core promoter and precore regions are frequently found in hepatitis B e antigen (HBeAg)-negative patients, but precore stop codon mutation is restricted to hepatitis B virus (HBV) genotypes that have T at nucleotide 1858. The aims of this study were to determine the role of core promoter and/or precore mutations in HBeAg seroconversion and their impact on the subsequent course of liver disease, and to determine if core promoter mutations are more frequently selected in patients with HBV genotypes that preclude the development of precore stop codon mutation. Serial sera from 45 patients with chronic HBV infection were polymerase chain reaction (PCR)-amplified, and the HBV core promoter and precore regions were sequenced. Ninety-two percent of patients had core promoter or precore mutations after HBeAg seroconversion: 42% had core promoter changes only, 38% had precore stop codon mutations only, and 12% had changes in both regions. Seventy-three percent of the patients had persistently normal aminotransferases, and only 8% had multiple flares in aminotransferases after HBeAg seroconversion. Core promoter changes were significantly more common in patients infected with HBV who have C at nucleotide 1858 (91% vs. 27%; P <.01), while precore stop codon changes were exclusively found in patients infected with HBV who have T at nucleotide 1858 (87% vs. 0; P <.01). The vast majority of our patients had core promoter and/or precore mutations after HBeAg seroconversion. Nevertheless, most patients had sustained remission of liver disease. Our data suggest that core promoter changes are preferentially selected in patients infected with HBV genotypes that preclude the development of precore stop codon mutation.

Effects of fluoxetine on functional outcomes after acute stroke (FOCUS): a pragmatic, double-blind, randomised, controlled trial

BACKGROUND

Results of small trials indicate that fluoxetine might improve functional outcomes after stroke. The FOCUS trial aimed to provide a precise estimate of these effects.

METHODS

FOCUS was a pragmatic, multicentre, parallel group, double-blind, randomised, placebo-controlled trial done at 103 hospitals in the UK. Patients were eligible if they were aged 18 years or older, had a clinical stroke diagnosis, were enrolled and randomly assigned between 2 days and 15 days after onset, and had focal neurological deficits. Patients were randomly allocated fluoxetine 20 mg or matching placebo orally once daily for 6 months via a web-based system by use of a minimisation algorithm. The primary outcome was functional status, measured with the modified Rankin Scale (mRS), at 6 months. Patients, carers, health-care staff, and the trial team were masked to treatment allocation. Functional status was assessed at 6 months and 12 months after randomisation. Patients were analysed according to their treatment allocation. This trial is registered with the ISRCTN registry, number ISRCTN83290762.

FINDINGS

Between Sept 10, 2012, and March 31, 2017, 3127 patients were recruited. 1564 patients were allocated fluoxetine and 1563 allocated placebo. mRS data at 6 months were available for 1553 (99·3%) patients in each treatment group. The distribution across mRS categories at 6 months was similar in the fluoxetine and placebo groups (common odds ratio adjusted for minimisation variables 0·951 [95% CI 0·839-1·079]; p=0·439). Patients allocated fluoxetine were less likely than those allocated placebo to develop new depression by 6 months (210 [13·43%] patients vs 269 [17·21%]; difference 3·78% [95% CI 1·26-6·30]; p=0·0033), but they had more bone fractures (45 [2·88%] vs 23 [1·47%]; difference 1·41% [95% CI 0·38-2·43]; p=0·0070). There were no significant differences in any other event at 6 or 12 months.

INTERPRETATION

Fluoxetine 20 mg given daily for 6 months after acute stroke does not seem to improve functional outcomes. Although the treatment reduced the occurrence of depression, it increased the frequency of bone fractures. These results do not support the routine use of fluoxetine either for the prevention of post-stroke depression or to promote recovery of function.

FUNDING

UK Stroke Association and NIHR Health Technology Assessment Programme.

Heterologously expressed Staphylococcus aureus fibronectin-binding proteins are sufficient for invasion of host cells

Staphylococcus aureus invasion of mammalian cells, including epithelial, endothelial, and fibroblastic cells, critically depends on fibronectin bridging between S. aureus fibronectin-binding proteins (FnBPs) and the host fibronectin receptor integrin alpha(5)beta(1) (B. Sinha et al., Cell. Microbiol. 1:101-117, 1999). However, it is unknown whether this mechanism is sufficient for S. aureus invasion. To address this question, various S. aureus adhesins (FnBPA, FnBPB, and clumping factor [ClfA]) were expressed in Staphylococcus carnosus and Lactococcus lactis subsp. cremoris. Both noninvasive gram-positive microorganisms are genetically distinct from S. aureus, lack any known S. aureus surface protein, and do not bind fibronectin. Transformants of S. carnosus and L. lactis harboring plasmids coding for various S. aureus surface proteins (FnBPA, FnBPB, and ClfA) functionally expressed adhesins (as determined by bacterial clumping in plasma, specific latex agglutination, Western ligand blotting, and binding to immobilized and soluble fibronectin). FnBPA or FnBPB but not of ClfA conferred invasiveness to S. carnosus and L. lactis. Invasion of 293 cells by transformants was comparable to that of strongly invasive S. aureus strain Cowan 1. Binding of soluble and immobilized fibronectin paralleled invasiveness, demonstrating that the amount of accessible surface FnBPs is rate limiting. Thus, S. aureus FnBPs confer invasiveness to noninvasive, apathogenic gram-positive cocci. Furthermore, FnBP-coated polystyrene beads were internalized by 293 cells, demonstrating that FnBPs are sufficient for invasion of host cells without the need for (S. aureus-specific) coreceptors.

Phase II evaluation of oral estramustine and oral etoposide in hormone-refractory adenocarcinoma of the prostate

PURPOSE

Estramustine and etoposide (VP-16) have been demonstrated to inhibit the growth of prostate cancer cells in experimental models. This led us to evaluate the effectiveness of this combination in the treatment of patients with metastatic prostate carcinoma refractory to hormone therapy.

PATIENTS AND METHODS

Estramustine 15 mg/kg/d and VP-16 50 mg/m2/d, were administered orally in divided doses for 21 days. Patients were then taken off therapy for 7 days and the cycle then repeated. Therapy continued until evidence of disease progression.

RESULTS

Forty-two patients have been enrolled onto this trial with a minimum of 40 weeks follow-up. Of 18 patients with measurable soft tissue disease, three demonstrated a complete response (CR) and six a partial response (PR) for longer than 2 months. Of these 18 patients, pretreatment prostate-specific antigen (PSA) levels decreased by at least 75% in five men (28%) and by at least 50% in nine (50%). The median survival duration has not been reached in those patients who demonstrated a response either by soft tissue or PSA criteria. Of 24 patients with disease limited to bone, six (25%) demonstrated improvement and nine (38%) demonstrated stability in their bone scans. Five men (21%) demonstrated a decrease of at least 75% in pretreatment PSA levels and 14 (58%) demonstrated at least a 50% decrease; the median survival duration has not been reached in these patients. Pretreatment performance status is an important predictor of survival.

CONCLUSION

We conclude that the combination of estramustine and VP-16 is an active oral regimen in hormone-refractory prostate cancer.

The delivery of antisense therapeutics

Antisense oligonucleotides, ribozymes and DNAzymes have emerged as novel, highly selective inhibitors or modulators of gene expression. Indeed, their use in the treatment of diseases arising from genetic abnormalities has become a real possibility over the past few years. The first antisense drug molecule is now available for clinical use in Europe and USA. However, their successful application in the clinic will require improvements in cellular targeting and intracellular delivery. This review aims to look at recent advances in the in vitro and in vivo delivery of antisense oligodeoxynucleotides and ribozymes.

Listeria monocytogenes in Fresh Produce: Outbreaks, Prevalence and Contamination Levels

Listeria monocytogenes, a member of the genus Listeria, is widely distributed in agricultural environments, such as soil, manure and water. This organism is a recognized foodborne pathogenic bacterium that causes many diseases, from mild gastroenteritis to severe blood and/or central nervous system infections, as well as abortion in pregnant women. Generally, processed ready-to-eat and cold-stored meat and dairy products are considered high-risk foods for L. monocytogenes infections that cause human illness (listeriosis). However, recently, several listeriosis outbreaks have been linked to fresh produce contamination around the world. Additionally, many studies have detected L. monocytogenes in fresh produce samples and even in some minimally processed vegetables. Thus L. monocytogenes may contaminate fresh produce if present in the growing environment (soil and water). Prevention of biofilm formation is an important control measure to reduce the prevalence and survival of L. monocytogenes in growing environments and on fresh produce. This article specifically focuses on fresh produce–associated listeriosis outbreaks, prevalence in growing environments, contamination levels of fresh produce, and associated fresh produce safety challenges.

Evolution of hepatitis B virus polymerase gene mutations in hepatitis B e antigen-negative patients receiving lamivudine therapy

Lamivudine has been shown to be effective in patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B, but its long-term efficacy and the rate of resistant mutations in patients with HBeAg-negative chronic hepatitis B is less clear. Twenty-nine patients with HBeAg-negative chronic hepatitis B, who have received lamivudine for at least 1 year were studied to determine the antiviral response, the rate and pattern of lamivudine-resistant mutations, and the effect of lamivudine-resistant mutations on HBeAg status. The mean duration of treatment was 21 +/- 7 months. Before treatment, core promoter variant was detected in 16 (55%) patients and precore stop codon variant in 18 (62%) patients. Serum hepatitis B virus (HBV) DNA was detected by solution hybridization assay in 62%, 4%, and 24% and by polymerase chain reaction (PCR) assay in 100%, 31%, and 40% at months 0, 6, and 24, respectively. The cumulative rates of detection of lamivudine-resistant mutations after 1 and 2 years of treatment were 10% and 56%, respectively. In addition to the duration of treatment, core promoter mutation was associated with the selection of lamivudine-resistant mutants. Three patients with lamivudine-resistant mutations had reversion of the precore stop codon mutation; in 2 patients this was accompanied by the reappearance of HBeAg. We found that lamivudine-resistant mutants were detected at similar rates in patients with HBeAg-negative as in patients with HBeAg-positive chronic hepatitis B. Additional changes in other parts of the HBV genome may restore the replication fitness of lamivudine-resistant mutants.

Hepatitis B e antigen-negative chronic hepatitis B in Hong Kong

Hepatitis B e antigen-negative chronic hepatitis B (e-CHB) has been reported in Asia but its prevalence and clinical significance have not been determined. The aims of this study were to determine the prevalence of e-CHB in Hong Kong and the frequency of precore and core promoter mutations in these patients. A cross-sectional study was performed in 350 consecutive Chinese patients (230 men and 120 women; mean age +/-SD, 42 +/- 13 years) with chronic hepatitis B virus infection. A total of 243 (69%) patients were hepatitis B e antigen (HBeAg)-negative of whom 15% had clinical cirrhosis. In the remaining 85% of patients, 63% had normal and 22% had elevated transaminases. Serum hepatitis B virus (HBV) DNA was detectable using branched DNA assay in 46% of HBeAg-negative patients with clinical cirrhosis/elevated transaminases. Forty-five percent of the patients with e-CHB had the precore stop codon mutation, and an additional 41% had core promoter changes. There was no correlation between the presence of precore/core promoter mutations and liver disease or HBV-DNA levels. Overall, 17% of HBeAg-negative patients were viremic and had evidence of chronic liver disease (e-CHB) with mean HBV-DNA levels comparable with that in HBeAg-positive patients. In summary, we found that e-CHB may be present in up to 17% of HBeAg-negative patients seen in a tertiary referral center in Hong Kong. e-CHB may be a heterogeneous condition and is not invariably associated with the precore HBV mutant. Population studies are needed to determine the true prevalence of e-CHB in Asia and to assess its natural course and response to treatment.

A longitudinal household study of Streptococcus pneumoniae nasopharyngeal carriage in a UK setting

A 10-month longitudinal household study of pre-school children and their families was undertaken with monthly visits collecting epidemiological data and nasopharyngeal swabs in Hertfordshire, England from 2001 to 2002. Pneumococcal culture was with standard methods. In total, 121 families (489 individuals) took part. Mean prevalence of carriage ranged from 52% for age groups 0-2 years, 45% for 3-4 years, 21% for 5-17 years and 8% for >or=18 years. Carriage occurred more than once in 86% of children aged 0-2 years compared to 36% of those aged >or=18 years. The most prevalent serotypes in the 0-2 years age group were 6B followed by 19F, 23F, 6A and 14. Young children were responsible for the majority of introductions of new serotypes into a household. Erythromycin resistance (alone or in combination) occurred in 10% of samples and penicillin non-susceptibility in 3.7%. Overall the recently licensed 7-valent conjugate vaccine (PCV) would protect against 64% of serotypes with no intra-serogroup cross protection and 82% with such protection. Nasopharyngeal carriage of S. pneumoniae is common in a UK setting in the pre-conjugate vaccine era. PCV would protect against a large proportion of carriage isolates. However, the impact of vaccination on non-vaccine serotypes will need to be monitored.

Combination paclitaxel, carboplatin, and gemcitabine is an active treatment for advanced urothelial cancer

PURPOSE

To determine the efficacy and toxicity of the drug combination of carboplatin, paclitaxel, and gemcitabine in patients with advanced urothelial carcinoma.

PATIENTS AND METHODS

Patients eligible included those with advanced urothelial malignancy of any histology, no previous chemotherapy for metastatic disease, Southwest Oncology Group performance status of 2 or less, serum creatinine levels of 2 mg/dL or less, and adequate bone marrow and hepatic function. Treatment consisted of paclitaxel 200 mg/m2, carboplatin (target area under the curve = 5) on day 1, and gemcitabine 800 mg/m2 on days 1 and 8, repeated every 21 days.

RESULTS

Forty-nine patients (44 men and five women) were enrolled; the patients' median age was 63 years, and their median creatinine clearance was 78 mL/min (range, 26 to 165 mL/min). Forty-three patients had transitional cell carcinoma, and six had squamous cell carcinoma or mixed histology. Ten patients had metastases to lymph nodes only, six had locally advanced disease, four had locally recurrent disease, 24 patients had visceral metastases, and five had soft tissue metastases. Twenty-one patients had disease in one site, 16 in two sites, and 12 in three sites. A total of 272 cycles were administered (median, six cycles; range, 1 to 15 cycles). Major toxicities were grade 3 and 4 neutropenia in 17 and 19 patients, respectively; grade 3 and 4 thrombocytopenia in 15 and six patients, respectively; grade 3 and 4 anemia in 10 and two patients, respectively; grade 3 neuropathy in four patients; and diarrhea in two patients. The incidence of febrile neutropenia was 1.4%; no patients died of drug toxicity. Forty-seven of the 49 patients were assessable for response. Fifteen (32%) patients experienced a complete response, and 17 (36%) patients experienced a partial response (32 of 47 patients, 68%; 95% confidence interval, 56.27 to 82.86). Responses were seen in all sites, including 15 (68%) of 22 patients with visceral metastases. The median survival was 14.7 months, with a 1-year survival of 59%.

CONCLUSION

Combination paclitaxel, carboplatin, and gemcitabine is active; an encouraging number of patients with advanced urothelial carcinoma treated with this regimen experienced complete remission.

Control of axillary bud initiation and shoot architecture in Arabidopsis through the SUPERSHOOT gene

The aerial architecture of flowering plants is determined to a large extent by shoot growth and shoot branching arising from the initiation and growth of axillary meristems. We have identified an Arabidopsis mutant, supershoot (sps), which is characterized by a massive overproliferation of shoots, such that a single plant can generate 500 or more inflorescences. Analysis of the mutant plants shows that the primary defect is because of an increase in the number of meristems formed in leaf axils, together with release of bud arrest, resulting in reiterative branch formation from rosette and cauline leaves. The SPS gene is shown here to encode a cytochrome P450, and together with a 3- to 9-fold increase in levels of Z-type cytokinins in sps mutant plants, indicate a role for SPS in modulating hormone levels. The expression pattern of SPS, with strong expression at the leaf axils, correlates well with the phenotypic defects. Our results indicate that control of shoot branching in Arabidopsis may be accomplished in part by suppression of axillary meristem initiation and growth through the localized attenuation of cytokinin levels at sites of bud initiation.

Phase II trial of paclitaxel and carboplatin in the treatment of advanced urothelial carcinoma

PURPOSE

Both paclitaxel and carboplatin have single-agent activity against carcinoma of the urothelium. We evaluated the combination of paclitaxel and carboplatin in the treatment of advanced cancers of the urothelium.

PATIENTS AND METHODS

Patients with cancers of the urothelium who had no prior chemotherapy (prior adjuvant chemotherapy > 6 months allowed) were eligible for treatment. Eligibility requirements were performance status of 2 or less, creatinine level less than 2.0 mg/dL, granulocyte count (AGC) 1,500/microL or greater, platelet count 100,000/microL or greater, and total bilirubin level less than 1.5 mg/dL. Paclitaxel 200 mg/m2 followed by carboplatin (area under the curve [AUC] 5, Calvert formula) were administered every 21 days. Patients were evaluated for toxicity weekly and assessed for response every 6 weeks.

RESULTS

Thirty-six patients were entered onto the study and 35 patients were assessable for response. A total of 184 cycles were administered (median, six cycles per patient). Nine patients required one dose reduction, and seven patients required two dose reductions for a nadir AGC less than 500/microL, with only one episode of febrile neutropenia and sepsis. Myalgias and arthralgias of grades 1 to 2 occurred in 16 patients and usually lasted 2 to 3 days after treatment. There were no treatment delays because of toxicity. There were 18 responses; seven complete responses (CRs) and 11 partial responses (PRs) (response rate 51.5%; 95% confidence interval, 35 to 68). Median response durations for CR and PR were 6 and 4 months, respectively. Overall median survival was 9.5 months.

CONCLUSION

The combination of paclitaxel and carboplatin is an active and well-tolerated regimen for the treatment of advanced urothelial carcinoma. Because of the modest toxicity of this combination, paclitaxel and carboplatin should be considered for addition to other agents with activity in urothelial carcinomas.

Prostate cancer: molecular biology of early progression to androgen independence

To improve the therapy for prostate cancer, it will be necessary to address the problems of progression to androgen independence and the process of metastatic spread of tumour. The complexity of the latter condition is likely to mitigate against the immediate development of relevant therapeutic approaches. However, the basis of androgen independence appears to be a problem of simpler dimensions and more amenable to treatment with current therapeutic technology. Since early tumour progression can be detected by an incomplete prostate-specific antigen (PSA) response to androgen withdrawal therapy, a study of the molecular biology of PSA gene regulation may well provide insight into new methods for preventing or delaying this problem. Mounting evidence suggests that ligand-independent activation of the androgen receptor may be one underlying mechanism of androgen independence. In the absence of androgen, a compensatory increase in the activity of cAMP-dependent protein kinase (PKA) enhances the ability of the androgen receptor to bind to the response elements regulating PSA gene expression. The activation of the androgen receptor through up-regulation of the PKA signal transduction pathway involves the amino-terminus of the androgen receptor, the function of which may be altered either by modifications such as phosphorylation, or through interactions with co-regulators or other proteins. Of therapeutic interest is the fact that this effect can be counteracted experimentally by the anti-androgen, bicalutamide, and clinically by several other similar agents. We speculate that the inhibition of PKA-activated androgen receptor might also be accomplished by decoy molecules that can bind to the relevant activated site on the amino-terminus or competitively interact with proteins recruited by the PKA pathway that are responsible for activating the receptor in the absence of androgen. Such molecules might include small mimetic substances or agents that can gain access to the nucleus of the cell.

Insulin-like growth factor I stimulates lipid oxidation, reduces protein oxidation, and enhances insulin sensitivity in humans

To elucidate the effects of insulin-like growth factor I (IGF-I) on fuel oxidation and insulin sensitivity, eight healthy subjects were treated with saline and recombinant human (IGF-I (10 micrograms/kg.h) during 5 d in a crossover, randomized fashion, while receiving an isocaloric diet (30 kcal/kg.d) throughout the study period. On the third and fourth treatment days, respectively, an L-arginine stimulation test and an intravenous glucose tolerance test were performed. A euglycemic, hyperinsulinemic clamp combined with indirect calorimetry and a glucose tracer infusion were performed on the fifth treatment day. IGF-I treatment led to reduced fasting and stimulated (glucose and/or L-arginine) insulin and growth hormone secretion. Basal and stimulated glucagon secretion remained unchanged. Intravenous glucose tolerance was unaltered despite reduced insulin secretion. Resting energy expenditure and lipid oxidation were both elevated, while protein oxidation was reduced, and glucose turnover rates were unaltered on the fifth treatment day with IGF-I as compared to the control period. Enhanced lipolysis was reflected by elevated circulating free fatty acids. Moreover, insulin-stimulated oxidative and nonoxidative glucose disposal (i.e., insulin sensitivity) were enhanced during IGF-I treatment. Thus, IGF-I treatment leads to marked changes in lipid and protein oxidation, whereas, at the dose used, carbohydrate metabolism remains unaltered in the face of reduced insulin levels and enhanced insulin sensitivity.

Cotton leaf curl disease is associated with multiple monopartite begomoviruses supported by single DNA beta

For bipartite begomoviruses (family Geminiviridae) trans-replication of the DNA B component by the DNA A-encoded replication-associated protein (Rep) is achieved by virtue of a shared sequence, the "common region", which contains repeated motifs (iterons) which are sequence-specific Rep binding sites and form part of the origin of replication. Recently cotton leaf curl disease (CLCuD), a major constraint to cotton production on the Indian subcontinent, has been shown to be caused by a monopartite begomovirus ( Cotton leaf curl Multan virus [CLCuMV]) and a novel single-stranded DNA satellite molecule termed CLCuD DNA beta. The satellite molecule is trans-replicated by CLCuMV but does not possess the iteron sequences of this virus. We have investigated the ability of CLCuD DNA beta to interact with three further clones of monopartite begomoviruses, isolated from cotton, that have distinct Rep binding specificities. All three cloned viruses were capable of trans-replicating the satellite molecule and inducing CLCuD symptoms in cotton, indicating that the interaction between begomovirus and DNA beta is relaxed in comparison to the interaction between DNA A and DNA B components. Field surveys across all the cotton growing regions of Pakistan indicate that dual and multiple infections are the norm for CLCuD with no evidence of synergism. Despite the diversity of begomoviruses associated with CLCuD, only a single class of DNA beta has been detected, suggesting that this satellite has the capacity to be recruited by unrelated begomoviruses.

A chemically defined medium for slime production by coagulase-negative staphylococci

In a chemically defined medium in which the principal constituents were glucose, 18 amino acids, two purines and six vitamins, eight strains of coagulase-negative staphylococci grew as rapidly and heavily as in tryptic soy broth. Slime formation was slightly better in the defined medium than in tryptic soy broth.

The slime of coagulase-negative staphylococci: biochemistry and relation to adherence

In recent years, infections of implanted plastic devices by coagulase-negative staphylococci have become a major cause of septicaemia in human patients. The causal bacterial species is usually Staphylococcus epidermidis and these organisms grow as a biofilm adherent to a solid surface. Several methods have been introduced to assess the mass of adherent bacteria and the slimy matrix in which they are embedded. Some methods measure total biofilm, others measure the organisms or the slime alone. In vitro, the type of medium, the atmosphere during incubation, and the nature of the solid surface, affect the quantity of biofilm that is formed. In most studies on the chemistry of the slime, the material used was formed on complex media solidified with agar. Contamination by ingredients of the media or by agar may not always have been recognised. Recent work with chemically defined medium (liquid or solidified with silica gel) shows that the slime is a mixture of about 80% (w/w) teichoic acid and 20% protein. Growth as a biofilm may protect the staphylococci from antibiotics. At present, the greatest success in preventing infection has come from improved surgical techniques during the insertion of implants.