Effect of aflatoxin culture on intestinal function and nutrient loss in laying hens

The negative effects of aflatoxins (AFLA) on hepatic necrosis and total tract digestibility of energy, N, and amino acids have been well documented. However, the question remains if this is an effect on nutrient metabolizability alone or an effect on the intestine, or both, resulting in increased endogenous nutrient loss or reduced nutrient retention, or both. Therefore, a 2-wk feeding study with a crude AFLA culture was conducted with laying hens to measure endogenous losses and digestive functionality of the intestine. Hy-Line W36 hens were fed 1 of 4 experimental diets containing a crude AFLA culture from 20 to 22 wk of age. Diets were analyzed to contain 0, 0.6, 1.2, or 2.5 mg/kg of AFLA B(1). Dietary AFLA concentration had no effect on BW, egg production, or feed intake. Intestinal crypt depth (but not villus length) increased linearly with increasing AFLA concentration. Similarly, specific activity of the intestinal disaccharidase, maltase, increased quadratically by feeding up to 1.2 mg/kg of AFLA and declined at 2.5 mg/kg of AFLA (P <or= 0.022). Although there was no effect of AFLA on goblet cell number, density, or crude mucin excretion (P > 0.05), sialic acid excretion increased quadradically such that it was increased 12% when 0.6 and 1.2 mg/kg of AFLA was fed versus the control (P <or= 0.025). Digestibility of DM and N per hen per day were unaffected by AFLA. Feeding of 0.6 and 1.2 mg/kg reduced the apparent digestible and AME(n) of the hen by 10 and 4%, respectively (P <or= 0.025). Because intestinal characteristics (intestinal morphology, sialic acid production, and apparent digestible energy) were altered by AFLA feeding, it can be surmised that AFLA can have a direct or indirect effect, or both, on functionality of the gastrointestinal tract.

Partial splenic embolization for hypersplenism in cirrhosis: a long-term outcome in 62 patients

BACKGROUND

Although partial splenic embolization (PSE) has been widely used for treatment of leucocytopaenia and thrombocytopaenia in cirrhosis, only few studies on the correlation between splenic infarction rate and long-term outcome of partial splenic embolization have been reported so far.

AIM

To evaluate long-term results of partial splenic embolization with different infarction rates in cirrhotic patients with hypersplenism.

METHODS

Sixty-two consecutive patients with hypersplenism in cirrhosis received partial splenic embolization. According to the splenic infarction rate after partial splenic embolization, the patients were divided into three groups: more than 70% in group A (n=12), 50-70% in group B (n=34), and less than 50% in group C (n=16). The post-partial splenic embolization following-up time was 5 years.

RESULTS

Before partial splenic embolization, there were no significant differences among the three groups with respect to sex, age, splenic volume, Child-Pugh class, oesophageal varices, and peripheral blood cell counts. After partial splenic embolization, the short- and long-term outcomes of leucocyte and platelet counts showed significant difference among the three groups (P<0.001). In groups A and B, the leucocyte and platelet counts after partial splenic embolization remained significantly higher than those before partial splenic embolization for 2 weeks to 5 years (P<0.05), the post-partial splenic embolization leucocyte and platelet counts was even higher in group A than in group B; while in group C, leucocyte and platelet count improvement only lasted for 6 months after partial splenic embolization. No significant changes were observed concerning blood red cell counts and liver function parameters after partial splenic embolization among the three groups. Severe complications occurred in six patients (50%) in group A and three patients (8.8%) in group B (P<0.05), while in group C, no severe complications developed.

CONCLUSIONS

In partial splenic embolization, the splenic infarction rate should be limited to 50%-70% in order to ensure the long-term efficacy in alleviating hypersplenism and reduce complications.

Safety and efficacy of neratinib (HKI-272) in combination with paclitaxel in patients with solid tumors

3557

Background: Neratinib (HKI-272) is a potent irreversible pan-ErbB inhibitor of the tyrosine kinase receptors, erbB-1,-2 and -4. In this phase 1 study, a combination dose of neratinib plus paclitaxel that is tolerable was determined in patients (pts) with solid tumors, and safety and preliminary efficacy were assessed in pts with erbB-2+ metastatic breast cancer. Methods: In this open label, 2-part study, ascending multiple daily oral doses of neratinib (160 mg, 240 mg) were administered in combination with IV paclitaxel 80 mg/m2, if tolerable, or 70 mg/m2 on days 1, 8 and 15. Pts with solid tumors and pts with only metastatic erbB-2+ breast cancer are enrolled in part 1 and 2, respectively. Tumor measurements were made at screening and at every 8 weeks (2 cycles) by modified RECIST criteria. Timed blood samples were collected for neratinib and paclitaxel plasma concentration determination, and PK analyses were performed using a noncompartmental method. Results: Data for 54 pts as of 30 Oct 2008 are presented (median age [range] of 51.5 [20–74] yrs; 91% female; 26 % with prior trastuzumab treatment of median duration [range] 32.5 [10–52] wks; 15% with prior lapatinib treatment). Tumor types in part 1 included breast, endometrial, cervical, colorectal and esophageal cancer. There were no dose-limiting toxicities (DLTs) at the 240 mg neratinib-80 mg/m2 paclitaxel dose, and as standard doses of neratinib and paclitaxel were reached, there was no reason for further escalation. Neratinib-related AEs, any grade in ≥10% of pts included diarrhea (50%), neutropenia (17%), rash (13%), nausea (11%) and vomiting (11%). Neratinib- related AEs, grade ≥3 in ≥2% of pts were diarrhea (20%), neutropenia (9%) and dehydration (4%). Only 2 pts (at the 240 mg neratinib-80 mg/m2 paclitaxel dose) had dose reductions due to diarrhea. In 35 efficacy evaluable pts, 5 had confirmed partial response (PR). Confirmed clinical benefit (PR and prolonged disease stabilization) was seen in 2 pts in part 1, 1 pt with endometrial cancer and 1 pt with cervical cancer. Conclusions: This combination of 240 mg neratinib and 80 mg/m2 paclitaxel was tolerable with a toxicity profile similar to that observed for neratinib, and had promising antitumor activity in pts with solid tumors and erbB-2 + breast cancer.

[Table: see text]

Neratinib in combination with trastuzumab for the treatment of advanced breast cancer: A phase I/II study

1004

Background: Neratinib (HKI-272) is an orally administered irreversible pan-ErbB receptor tyrosine kinase inhibitor. In an ongoing phase II study, the preliminary objective response rate was 26% in patients with ErbB2+ advanced breast cancer with prior trastuzumab therapy. This study assessed the safety and preliminary efficacy of the combination of neratinib plus trastuzumab. Methods: Patients with advanced ErbB2+ breast cancer that progressed following trastuzumab therapy were enrolled. The primary endpoint was 16-week progression free survival rate (PFS). In part 1 (dose escalation), patients received neratinib 160 mg or 240 mg daily plus trastuzumab 4 mg/kg IV loading dose then 2 mg/kg weekly. In part 2, patients received weekly trastuzumab with neratinib 240 mg daily. Timed blood samples were collected for PK analyses. PK analysis is ongoing. Results: 45 patients (part 1 n = 8; part 2 n = 37) were enrolled (mean age 52 yr); 9 are active. In part 1, cohorts 1 and 2 were fully enrolled with 4 patients each. No dose limiting toxicities were observed. Most common AEs, any grade, were diarrhea (91%), nausea (51%), anorexia (40%), vomiting (38%), and asthenia (27%). Grade 3/4 AEs were diarrhea (13%), nausea (4%), vomiting (4%). Two patients receiving neratinib 240 mg reported AEs leading to withdrawal. No AEs of congestive heart failure and no significant drops of left ventricular ejection fraction were reported. Among 33 patients evaluable for efficacy, objective response rate was 27% (95% CI, 13% - 46%); 16-week PFS rate (for part 2) 47% (95% CI, 29% - 63%); median PFS was 19 weeks (95% CI 15 - 32 weeks). Conclusions: Neratinib plus trastuzumab was well tolerated with no significant or unexpected toxicities, and demonstrated clinical activity.

[Table: see text]

Population pharmacokinetics of 3-aminopyridine-2-carboxaldehyde thiosemicarbazone in cancer patients

2508

Background: 3-Aminopyridine-2-carboxaldehyde thiosemicarbazone (3AP) is an inhibitor of ribonucletoide reductatse with activity in hematological malignancies as well as melanoma and prostate cancer. This study describes the population PK of 3AP and the relationship between 3AP disposition and patient covariates. Methods: 40 pts with advanced cancer from two phase 1 studies were included in the PK model building. Pts received 3AP 25–105 mg/m2 IV on day 1. 3AP plasma and erythrocyte levels were sampled at 10 timepoints over a 24-hour period and measured by a validated HPLC method. Data were analyzed by a nonlinear mixed- effects modeling approach with NONMEM system Version V. Xpose10 and S-PLUS were used for goodness-of-fit assessment and model evaluation to obtain clearance (CL), volume of distribution (V) for compartment (C) 1, plasma (V1); V for C2, erythrocytes (V2); and V for C3 (V3). 15 covariates were evaluated, including: weight, BSA, gender, PS, age, ABCB1[C1236T, G2667T, C3436T] genotypes, toxicity, concurrent chemotherapy [irinotecan, doxorubicin], response and number of cycles administered. Normal renal and hepatic function were required for study entry and were not included as covariates. Response was assessed after 2 cycles of therapy. Results: 3AP PK were described as a 3-compartment model with first-order elimination. Estimated paramaters were: V1 =5.68 L/m2 (95%CI 4.3–7.1); V2=18.9 L/m2 (95%CI 14.6–23.2); V3= 40.0 L/m2 (95%CI 23.8–55.4); CL 25.4 L/hr/m2 (95%CI 22.4–28.4). Gender was associated with V; women had a lower V2 (p<0.05). This may be related to a lower hemoglobin in women. The number of cycles administered was associated with decreased CL; those with decreased CL received less than 2 cycles before going off study. Conclusions: Women had a lower V2 than men and pts with decreased CL received less than 2 cycles of therapy, suggesting PK may be helpful in individualizing dosing. ABCB1 genotypes and concurrent irinotecan or doxorubicin do not influence 3AP disposition. Supported by: U01CA062491 “Early Clinical Trials of Anti-Cancer Agents with Phase I Emphasis” NCI; CTEP TRI Funding 24XS090, and 1ULRR025011 Clinical and Translational Science Award of the National Center for Research Resources, NIH.

No significant financial relationships to disclose.

The nutritional value of high-protein corn distillers dried grains for broiler chickens and its effect on nutrient excretion

Two experiments were conducted with a co-product of corn endosperm fermentation. The first experiment determined nutrient digestibility of high-protein corn distillers dried grains (HP-DDG; 54% CP) after feeding semipurified diets from 15 to 22 d of age. The AMEn of HP-DDG was 2,526 kcal/kg, whereas standardized ileal Lys, Met, and Thr digestibilities were 73.0, 84.9, and 73.0%, respectively. In a second experiment, an industry control diet (I) regimen was compared with that of either an approximate 25 or 50% replacement for the level of 48% CP soybean meal (SBM) inclusion in the diet utilizing the amino acid digestibility and AMEn determined from the first experiment. From 0 to 14, 14 to 28, and 28 to 42 d of age, the HP-DDG in the 50% SBM replacement diet was added at 25, 23.5, and 21% of the diet, respectively. To meet digestible amino acid needs, the diet containing 50% SBM replacement with HP-DDG contained 3.2, 3.6, and 4.4% units more CP than the I diet regimen from 1 to 14, 14 to 28, and 28 to 42 d of age, respectively. Dietary replacement of up to 50% of SBM inclusion with HP-DDG had no effect on bird performance at 14 or 42 d of age or breast fillet yield at 42 d of age; however, it decreased BW gain and increased feed:gain ratio from 14 to 28 d of age. Birds consuming a diet with 50% replacement of SBM with HP-DDG consumed 17.1% more N compared with those consuming I diets. This additional N and fiber consumed resulted in birds being fed the 50% replacement for SBM diet excreting 21.9 and 31.8% more manure DM and N, respectively. Due in large part to the amino acid profile and digestibility of HP-DDG, use of this feedstuff as a large proportion of the diet is feasible but results in more manure and manure N from broilers.

Intermodal four-wave mixing from femtosecond pulse-pumped photonic crystal fiber

Large Stokes-shift ( approximately 4700 cm(-1)) four-wave mixing is generated in a deeply normal dispersion regime from a 20 cm commercial large-mode-area photonic crystal fiber pumped by amplified approximately 800 nm femtosecond pulses. The phase-matching condition is realized through an intermodal scheme involving two pump photons in the fundamental fiber mode and a pair of Stokesanti-Stokes photons in a higher-order fiber mode. Over 7% conversion efficiency from the pump input to 586 nm anti-Stokes signal has been attained.

Band structure asymmetry of bilayer graphene revealed by infrared spectroscopy

We report on infrared spectroscopy of bilayer graphene integrated in gated structures. We observe a significant asymmetry in the optical conductivity upon electrostatic doping of electrons and holes. We show that this finding arises from a marked asymmetry between the valence and conduction bands, which is mainly due to the inequivalence of the two sublattices within the graphene layer and the next-nearest-neighbor interlayer coupling. From the conductivity data, the energy difference of the two sublattices and the interlayer coupling energy are directly determined.