Tuft cells mediate commensal remodeling of the small intestinal antimicrobial landscape.

Succinate produced by the commensal protist Tritrichomonas musculis (T. mu) stimulates chemosensory tuft cells, resulting in intestinal type 2 immunity. Tuft cells express the succinate receptor SUCNR1, yet this receptor does not mediate antihelminth immunity nor alter protist colonization. Here, we report that microbial-derived succinate increases Paneth cell numbers and profoundly alters the antimicrobial peptide (AMP) landscape in the small intestine. Succinate was sufficient to drive this epithelial remodeling, but not in mice lacking tuft cell chemosensory components required to detect this metabolite. Tuft cells respond to succinate by stimulating type 2 immunity, leading to interleukin-13-mediated epithelial and AMP expression changes. Moreover, type 2 immunity decreases the total number of mucosa-associated bacteria and alters the small intestinal microbiota composition. Finally, tuft cells can detect short-term bacterial dysbiosis that leads to a spike in luminal succinate levels and modulate AMP production in response. These findings demonstrate that a single metabolite produced by commensals can markedly shift the intestinal AMP profile and suggest that tuft cells utilize SUCNR1 and succinate sensing to modulate bacterial homeostasis.

Double peroxidase and histone acetyltransferase AgTip60 maintain innate immune memory in primed mosquitoes.

Immune priming in Anopheles gambiae is mediated by the systemic release of a hemocyte differentiation factor (HDF), a complex of lipoxin A4 bound to Evokin, a lipid carrier. HDF increases the proportion of circulating granulocytes and enhances mosquito cellular immunity. Here, we show that Evokin is present in hemocytes and fat-body cells, and messenger RNA (mRNA) expression increases significantly after immune priming. The double peroxidase (DBLOX) enzyme, present in insects but not in vertebrates, is essential for HDF synthesis. DBLOX is highly expressed in oenocytes in the fat-body tissue, and these cells increase in number in primed mosquitoes. We provide direct evidence that the histone acetyltransferase AgTip60 (AGAP001539) is also essential for a sustained increase in oenocyte numbers, HDF synthesis, and immune priming. We propose that oenocytes may function as a population of cells that are reprogrammed, and orchestrate and maintain a broad, systemic, and long-lasting state of enhanced immune surveillance in primed mosquitoes.

Effect of naturally occurring Wolbachia in Anopheles gambiae s.l. mosquitoes from Mali on Plasmodium falciparum malaria transmission.

A naturally occurring Wolbachia strain (wAnga-Mali) was identified in mosquitoes of the Anopheles gambiae complex collected in the Malian villages of Dangassa and Kenieroba. Phylogenetic analysis of the nucleotide sequence of two 16S rRNA regions showed that wAnga-Mali clusters with Wolbachia strains from supergroup A and has the highest homology to a Wolbachia strain isolated from cat fleas (Ctenocephalides). wAnga-Mali is different from two Wolbachia strains previously reported in A. gambiae from Burkina Faso (wAnga_VK5_STP and wAnga_VK5_3.1a). Quantitative analysis of Wolbachia and Plasmodium sporozoite infection in field-collected mosquitoes indicates that the prevalence and intensity of Plasmodium falciparum sporozoite infection is significantly lower in Wolbachia-infected females. The presence of Wolbachia in females from a laboratory Anopheles coluzzii (A. gambiae, M form) colony experimentally infected with P. falciparum (NF54 strain) gametocyte cultures slightly enhanced oocyst infection. However, Wolbachia infection significantly reduced the prevalence and intensity of sporozoite infection, as observed in the field. This indicates that wAnga-Mali infection does not limit early stages of Plasmodium infection in the mosquito, but it has a strong deleterious effect on sporozoites and reduces malaria transmission.

Biomarker results from the AVADO phase 3 trial of first-line bevacizumab plus docetaxel for HER2-negative metastatic breast cancer.

BACKGROUND: Combining bevacizumab with first-line chemotherapy significantly improves progression-free survival (PFS) in HER2-negative metastatic breast cancer (mBC). However, identification of patients benefitting most from bevacizumab remains elusive. The AVADO trial included an extensive optional exploratory biomarker programme. METHODS: Patients with HER2-negative mBC were randomised to receive docetaxel with placebo or bevacizumab. The primary end point was PFS. Plasma samples were analysed using a multiplex ELISA. Blood mRNA expression was assessed using quantitative PCR. Tumour tissue samples were analysed by immunohistochemistry. Single-nucleotide polymorphisms (SNPs) involved in the VEGF pathway were analysed in germline DNA. RESULTS: Samples for biomarker analysis were available from 24-54% of the 736 treated patients (depending on specimen type). The most consistent potential predictive effect was observed with plasma VEGF-A and VEGFR-2; high baseline concentrations were associated with greater treatment effect. Blood mRNA analyses suggested a greater bevacizumab effect in patients with high VEGF121. No consistent predictive effect was seen for tumour neuropilin or other candidate tumour markers by immunohistochemistry, or for any of the SNPs investigated. CONCLUSION: Plasma VEGF-A and VEGFR-2 are potential predictive markers for bevacizumab efficacy, supporting findings in gastric and pancreatic cancers. Plasma VEGF-A is being evaluated prospectively in mBC in the MERiDiAN trial.

First-line bevacizumab in combination with chemotherapy for HER2-negative metastatic breast cancer: pooled and subgroup analyses of data from 2447 patients.

BACKGROUND: Bevacizumab has consistently demonstrated improved progression-free survival (PFS) and response rate when combined with first-line chemotherapy for HER2-negative metastatic breast cancer (mBC). However, the lack of a significant overall survival (OS) difference continues to attract debate, and identification of patients deriving greatest benefit from bevacizumab remains elusive. PATIENTS AND METHODS: Individual patient data from three randomised phase III trials in the first-line HER2-negative mBC setting were analysed, focusing specifically on efficacy in poor-prognosis patients. RESULTS: The meta-analysis (n = 2447) demonstrated a PFS hazard ratio (HR) of 0.64 (95% confidence interval [CI] 0.57-0.71; median 9.2 months with bevacizumab versus 6.7 months with non-bevacizumab therapy) and response rate of 49% versus 32%, respectively. The OS HR was 0.97 (95% CI 0.86-1.08); median 26.7 versus 26.4 months, respectively. In patients with triple-negative mBC, the HRs for PFS and OS were 0.63 (95% CI 0.52-0.76) and 0.96 (95% CI 0.79-1.16), respectively. Median PFS was 8.1 months with bevacizumab versus 5.4 months with chemotherapy alone, median OS was 18.9 versus 17.5 months, respectively, and 1-year OS rates were 71% versus 65%. CONCLUSIONS: Bevacizumab improves efficacy, including 1-year OS rates, both overall and in subgroups of poor-prognosis patients with limited treatment options.

Randomized phase II non-inferiority study (NO16853) of two different doses of capecitabine in combination with docetaxel for locally advanced/metastatic breast cancer.

BACKGROUND: This phase II study investigated whether a lower-than-approved dose of capecitabine, plus docetaxel (XT), would improve tolerability versus standard-dose XT without compromising efficacy. PATIENTS AND METHODS: Women aged ≥18 years with locally advanced/metastatic breast cancer resistant to anthracycline-based chemotherapy in the (neo)adjuvant, first- or second-line metastatic setting were eligible. Patients were randomly assigned to receive standard-dose XT (capecitabine 1250 mg/m(2) twice daily, days 1-14; docetaxel 75 mg/m(2), day 1 every 3 weeks) or low-dose XT (capecitabine 825 mg/m(2) twice daily, days 1-14; docetaxel as above). The primary objective was to demonstrate non-inferiority of low-dose to standard-dose XT in terms of progression-free survival (PFS). RESULTS: 470 patients were randomly allocated in a 1 : 1 ratio to standard-dose or low-dose XT. Median PFS was 7.9 versus 5.8 months [hazard ratio 1.16, 95% confidence interval (CI) 0.95-1.43] in the standard-dose and low-dose arms, respectively. The upper limit of the 95% CI was above the predefined non-inferiority margin (1.35, P = 0.078). Secondary efficacy end points were consistent with PFS. The frequency and severity of adverse events was similar in both treatment arms. CONCLUSIONS: Non-inferiority of low-dose to standard-dose XT in terms of PFS was not demonstrated; this may be due to regional subgroup effects.

Comparing the effects of bisphenol A, C, and F on bovine theca cells in vitro.

Endocrine disrupting chemicals (EDCs) target aspects of hormone activity. Tightly coordinated crosstalk between two somatic cells of the ovary, granulosa and theca cells, governs steroid hormone production and plays a critical role in reproduction. It is thus pertinent to understand the impact of EDCs on granulosa and theca cells. Bisphenol A (BPA), a well-known EDC, is widely used in the manufacturing of consumer products with humans routinely exposed. Strong evidence of the adverse effects of BPA on the female reproductive system has emerged and as a result, manufacturers have begun replacing BPA with other bisphenols, such as BPC and BPF. The safety of these analogs is currently unclear and should be investigated independently. Although much is known about the impact of BPA on granulosa cells, similar study of theca cells has been neglected. Further, there is a lack of studies on the impact of BPC and BPF on the female reproductive system. To fill these gaps, the present study compared the effect of BPA, BPC, and BPF on the viability and steroid production of theca cells from bovine, a clinically relevant model for human reproduction. We show that BPC is more detrimental to theca cell viability and progesterone production compared to BPA. Surprisingly, we also found that BPF induces an increase in progesterone production compared to a decrease with BPA and BPC. To determine safety for the reproductive system, we conclude that a major shift away from BPA to bisphenol analogs should be investigated more thoroughly.

Bevacizumab in combination with taxanes for the first-line treatment of metastatic breast cancer.

BACKGROUND: Taxanes are an established treatment of metastatic breast cancer (mBC). Biological therapies that can be effectively combined with taxanes may provide an alternative to taxane-chemotherapy doublets, which are not suitable for all patients. PATIENTS AND METHODS: Bevacizumab is a humanised mAb against vascular endothelial growth factor (VEGF) which inhibits angiogenesis. This review summarises outcomes from trials evaluating bevacizumab in the first-line treatment of mBC. RESULTS: Bevacizumab demonstrated considerable efficacy in combination with taxane therapy in the first-line treatment of human epidermal growth factor receptor-2 (HER2)-negative mBC in three phase III trials. Improved response rate and progression-free survival (PFS) were also observed in patients who had received taxanes in the adjuvant setting. Bevacizumab-taxane combinations are effective across a broad range of patient subgroups and have greater efficacy than single-agent taxanes in first-line mBC. Importantly, the tolerability of bevacizumab-taxane combinations compares favourably with that of taxanes in combination with other chemotherapy agents. CONCLUSIONS: Bevacizumab-taxane combinations provide an alternative to chemotherapy doublet regimens in first-line mBC, with equivalent efficacy and potentially lower toxicity. Ongoing trials are investigating the efficacy and safety of bevacizumab in various stages of breast cancer and in breast cancer with a range of hormonal or receptor characteristics.

Stocking density and physiological adaptive responses of broilers.

Three trials were conducted to assess the effects of stocking density on physiological adaptive responses of broilers. Male broilers were reared in floor pens under conditions similar to those used commercially in the United States. Accepted indicators of adaptation to a stressor were measured on d 49 including plasma concentrations of corticosterone, glucose, cholesterol, and total nitrites as an indicator of nitric oxide, as well as heterophil:lymphocyte ratio. In trial 1, calculated stocking densities were 20, 25, 30, 35, 40, 45, 50, and 55 kg of BW/ m2 and in trials 2 and 3, stocking densities were 30, 35, 40, and 45 kg of BW/m2. Stocking densities were calculated based on a final BW of 3.3 kg. Linear trend analyses were used to assess the role of stocking density on each of the physiological parameters. Results indicate that stocking density did not cause physiological adaptive changes indicative of stress.

A conformational basis for the antiviral inactivity of tetrazole ribonucleosides.

The antiviral activity of ribavirin has been associated with its inhibition of the enzyme, IMP dehydrogenase. The ability of ribavirin to inhibit this enzyme has previously been shown to be related to its stability in the high anti glycosidic conformation. The antiviral effectiveness of several analogs of ribavirin have been investigated recently. The evidence indicates their antiviral effectiveness is related to their stability in the high anti conformation. Recently the disposition of purine analogs that pass through the inosine monophosphate branch point has been investigated. The results of these studies are consistent with the concept that the conversion of IMP to XMP requires the high anti conformation and that the conversion of IMP to adenylosuccinate requires some other conformation, possibly the anti conformation.

MUC1 and cancer.

The MUC1 membrane mucin was first identified as the molecule recognised by mouse monoclonal antibodies directed to epithelial cells, and the cancers which develop from them. Cloning the gene showed that the extracellular domain is made up of highly conserved repeats of 20 amino acids, the actual number varying between 25 and 100 depending on the allele. Each tandem repeat contains five potential glycosylation sites, and between doublets of threonines and serines lies an immunodominant region which contains the epitopes recognised by most of the mouse monoclonal antibodies. The O-glycans added to the mucin produced by the normal breast are core 2 based and can be complex, while the O-glycans added to the breast cancer mucin are mainly core 1 based. This means that some core protein epitopes in the tandem repeat which are masked in the normal mucin are exposed in the cancer associated mucin. Since novel carbohydrate epitopes are also carried on the breast cancer mucin, the molecule is antigenically distinct from the normal breast mucin. (Changes in glycosylation in other epithelial cancers have been observed but are not so well documented.) Immune responses to MUC1 have been seen in breast and ovarian cancer patients and clinical studies have been initiated to evaluate the use of antibodies to MUC1 and of immunogens based on MUC1 for immunotherapy of these patients. The role of the carbohydrates in the immune response and in other interactions with the effector cells of the immune system is of particular interest and is discussed.

Received dose-intensity: a randomized trial of weekly chemotherapy with and without granulocyte colony-stimulating factor in small-cell lung cancer.

PURPOSE: A prospective randomized trial to determine if granulocyte colony-stimulating factor (G-CSF) could increase the received dose-intensity (RDI) of weekly chemotherapy in patients with small-cell lung cancer (SCLC). PATIENTS AND METHODS: Forty patients with SCLC with good prognostic features (all patients with limited disease [LD], and extensive-disease [ED] patients with Eastern Cooperative Oncology Group [ECOG] 0 or 1 and plasma alkaline phosphatase levels < 1.5 times the upper limit of normal) were randomized to receive weekly chemotherapy with or without G-CSF. G-CSF (5 micrograms/kg) was self-administered subcutaneously on days when chemotherapy was not given. Chemotherapy consisted of cisplatin 50 mg/m2 intravenously (IV) on day 1 and etoposide 75 mg/m2 IV on days 1 and 2 alternating weekly with ifosfamide 2 g/m2 IV (with mesna) and doxorubicin 25 mg/m2 on day 1, for a total of 12 courses. Dose modifications (dose reductions and treatment delays) were made according to defined hematologic criteria. RESULTS: Dose reductions were made at some point during treatment in 12 of 17 patients in the control arm and in 11 of 23 patients in the G-CSF arm (P = .20). The proportion of patients experiencing dose reductions due to leukopenia was significantly higher in the control arm (nine of 17) compared with the G-CSF arm (four of 23, P < .04). Cycle delays due to leukopenia were similar in both arms of the study. The RDI was 82% of projected in the control arm (95% confidence interval [CI], 79% to 84%) and 84% in patients receiving G-CSF (95% CI, 82% to 87%) (P value not significant). CONCLUSION: In this randomized trial, G-CSF significantly decreased dose reductions due to neutropenia. However, administration of G-CSF did not decrease dose reductions or treatment delays to a level that would allow an increase in received dose-intensity. Nonhematologic toxicities such as increased creatinine concentration also prevented an increase in the RDI in the G-CSF arm.

Intensive weekly chemotherapy for good-prognosis patients with small-cell lung cancer.

A weekly, intensive chemotherapy regimen has been used to treat 70 patients with small-cell lung cancer (SCLC). Forty-five patients had limited disease (LD) and 25 extensive disease (ED) with good prognostic features. The regimen consisted of cisplatin 50 mg/m2 intravenously (IV) day 1 and etoposide 75 mg/m2 IV days 1 and 2, alternating weekly with ifosfamide 2 g/m2 IV day 8 and doxorubicin 25 mg/m2 IV day 8, for a total of 12 weeks. Dose modifications were made according to defined hematologic criteria. Responding patients with limited disease subsequently received mediastinal radiotherapy. Overall response to chemotherapy was 91% with a complete response (CR) rate of 50%. Forty-five patients with limited disease (LD) achieved an overall response rate of 91% with a CR rate of 51%, and 25 patients with extensive disease (ED) achieved an overall response rate of 92% with a CR rate of 48%. Median survival for the whole group was 54 weeks (LD, 58 weeks; ED, 42 weeks). Hematologic toxicity was predictable, without the wide fluctuations in WBC count seen in conventional 3-weekly regimens. In all, one quarter of treatment courses were delayed, most frequently because of leukopenia. Dose reductions were required in 63% of cases. The average delivered dose intensity was calculated and shown to be 73% of projected. Nonhematologic toxicity was mild with nausea and vomiting being the most common. This weekly schedule of chemotherapy has proved to be active and well tolerated and is currently being compared with conventional 3-weekly chemotherapy in a randomized study.

Therapeutic aspects of polymorphic epithelial mucin in adenocarcinoma.

The gene MUC1 encodes a large membrane-associated glycoprotein, previously termed polymorphic epithelial mucin and now known as MUC1. The majority of the extracellular domain is made up of tandem repeats of 20 amino acids. In some epithelial malignancies, MUC1 is up-regulated, and as a result of changes in glycosyl and sialytransferases, the complex carbohydrate side chains are truncated, leading to exposure of novel peptide and carbohydrate epitopes. Cellular and humoral immune responses to MUC1 have been documented in malignant disease, and T-cell responses to MUC1 may not depend on presentation by the major histocompatibility complex. Several immunogens based on MUC1 are being investigated. These include cell lines expressing MUC1 given alone or fused with professional antigen-presenting cells and peptide epitopes, given either with conventional immunological adjuvants or coupled to mannan, which may target uptake into antigen-presenting cells. Cellular and humoral immune responses to these agents have been recorded in patients with advanced malignancy. Targeting of peptide epitopes may also be achieved using antibodies to MUC1 through induction of idiotypes and retrospective analyses in ovarian cancer have suggested a survival benefit for patients. The use of cDNA in coding MUC1 may allow endogenous processing of antigen. Phase I studies using vaccinia as a vector have been completed. Studies using carbohydrate antigens suggest that the ability to generate specific immune responses may influence survival of patients with metastatic epithelial malignancies. While examining the potential role of immunogens based on MUC1, it is also necessary to understand the nature of immunosuppression in patients with advanced malignancy in order to develop strategies to enhance the immunogenicity of potential cancer vaccines.

Impact of tamoxifen on the pharmacokinetics and endocrine effects of the aromatase inhibitor letrozole in postmenopausal women with breast cancer.

This study examined whether the addition of tamoxifen to the treatment regimen of patients with advanced breast cancer being treated with the aromatase inhibitor letrozole led to any pharmacokinetic or pharmacodynamic interaction. Twelve of 17 patients completed the core period of the trial in which 2.5 mg/day letrozole was administered alone for 6 weeks and in combination with 20 mg/day tamoxifen for the subsequent 6 weeks. Patients responding to treatment continued on the combination until progression of disease or any other reason for discontinuation. Plasma levels of letrozole were measured at the end of the 6-week periods of treatment with letrozole alone and the combination and once more between 4 and 8 months on combination therapy. No further measurements were done thereafter. Hormone levels were measured at 2-week intervals throughout the core period. Marked suppression of estradiol, estrone, and estrone sulfate occurred with letrozole treatment, and this was not significantly affected by the addition of tamoxifen. However, plasma levels of letrozole were reduced by a mean 37.6% during combination therapy (P<0.0001), and this reduction persisted after 4-8 months of combination therapy. Letrozole is the first drug to be described in which this pharmacokinetic interaction occurs with tamoxifen. The mechanism is likely to be a consequence of an induction of letrozole-metabolizing enzymes by tamoxifen but was not further addressed in this study. It is possible that the antitumor efficacy of letrozole may be affected. Thus, sequential therapy may be preferable with these two drugs. It is not known whether tamoxifen interacts with other members of this class of drugs or with other drugs in combination.

A phase II study of pemetrexed disodium (LY231514) in patients with locally recurrent or metastatic breast cancer.

A phase II study was conducted to evaluate the activity of pemetrexed in patients with locally recurrent or metastatic breast cancer. 38 patients, median age 52 years (range 36-71 years), were given pemetrexed 600 mg/m(2) as a 10-min intravenous (i.v.) infusion every 3 weeks. Median time from diagnosis to study entry was 48 months (range 14.7-310 months). 33 of 38 patients had prior chemotherapy; 16 adjuvant, 12 metastatic and 5 in both settings. Sites of disease included skin and soft tissue (19/38) nodes (18/38), lung (17/38), liver (13/38) and bone (3/38). An overall response rate of 28% (95% confidence interval (CI): 14.2-45.2%) in 10/36 evaluable patients (1 complete response (CR), 9 partial responses (PR)), included reductions in hepatic and pulmonary metastases. 5 of 10 responders had received taxoid or anthracycline therapy for metastatic disease; 3 of these 5 had also received adjuvant chemotherapy. Median duration of response was 8 months (range 1.6-14+ months), and median survival was 13 months (95% CI 9.56-17.38 months). 167 courses were given (median five per patient; range 1-9), with 37 reductions and 33 delays. Reasons for reduction included neutropenia (11%) and mucositis (5%), with delays due to raised LFTs (21%), neutropenia (12%) and other non-treatment related events. The major haematological toxicities (Common Toxicity Criteria) (CTC) were grade 3/4 neutropenia (47%) and thrombocytopenia (15.7%) of patients. There was one report of a grade 3 infection. Non-haematological toxicities (all grades 2/3) included elevated transaminases (92%), vomiting (34%), nausea (34%) and mucositis (32%). One episode of grade 4 diarrhoea was reported. Other toxicities included a skin rash, grade 2 (42%), 3 (5%) and 4 (13%), which was ameliorated by the use of prophylactic dexamethasone. These results suggest that pemetrexed has significant antitumour activity in advanced breast cancer with responses in patients who had previously received anthracyclines and taxoids.

Bone changes in polycythaemia vera and myelosclerosis.

To study the problem of new bone formation in myelosclerosis bone biopsies have been performed in cases of polycythaemia vera, which may be regarded as a pre-myelosclerotic condition, and in primary myelosclerosis; morphological studies of bone and reticulin were made and osteoid and bone matrix was quantitatively assessed. Relevant metabolic studies were also carried out, but were predominantly normal. No new bone formation was detected in polycythaemia vera and some bone was osteoporotic; no significant increase in osteoid was found. With the use of polarized light it was found that new bone formation in myelosclerosis resulted from the ossification of wavy argyrophilic fibres in marrow: the presence of a dense network of these wavy fibres was a pre-requisite of new bone formation and ossification of the non-refractile branched reticulin fibres was not observed.

Activity and toxicity of carboplatin and iproplatin in relapsed high-grade glioma.

A total of 15 patients with relapsed high-grade glioma were treated with carboplatin (400 mg/m2) or iproplatin (300 mg/m2). All had received previous radiotherapy, and 12 had previously undergone chemotherapy. One of the ten patients treated with carboplatin and one of the five treated with iproplatin achieved a partial remission as determined by repeat computerised tomographic (CT) scan. Myelosuppression was considerable, as three patients developed grade IV neurotoxicity, which was fatal in one case. Although carboplatin and iproplatin showed activity against malignant glioma, the study was closed because of unacceptable toxicity.

High-dose epirubicin as primary chemotherapy in advanced breast carcinoma: a phase II study.

A total of 40 patients with metastatic breast cancer were treated with 120 mg/m2 i.v. epirubicin every 3 weeks for a maximum of 10 cycles. Nine achieved a complete response and 17 showed a partial response, for an objective response rate of 65% (95% confidence interval, 47%-83%); the median duration of response was 7 months (range, 1-15 months) and median survival amounted to 13 months (range, 2-20 months). Leucopenia (grade 2 or 3) was seen in 14 patients on day 21 of the cycle. A subset of nine patients underwent blood counts on day 10, when all had marked neutropenia (less than 1 x 10(9)/l). Other toxicity was frequent and included nausea/vomiting (80%), alopecia (95%) and stomatitis (35%). Five patients showed a significant fall in cardiac output, but this reverted to normal after treatment. Epirubicin should have a role in the development of high-dose regimens for the treatment of advanced breast cancer.