RACK1, a potential target to decrease morphine reward in mice

Morphine reexposure induces the decrease of receptor for activated C-kinase 1 protein (RACK1) levels in frontal cortex, and the increase of p-ERK (extracellular signal-regulated kinase) levels in mouse frontal cortex, striatum, hippocampus and nucleus accumbens (NAcc). Moreover, RACK1 is associated with the core kinases of the ERK pathway, Raf, MEK, and ERK. The purpose of this study is to investigate the effect of overexpression of RACK1 on the conditioned place preference (CPP) and the level of p-ERK in morphine reexposure mice. Mice were subcutaneously injected with morphine on the 2nd, 4th, 6th, and the 8th day, saline was delivered the next day. After mice showed place preference, RACK1 was administered by intraventricular injection 20 minutes after injection of morphine on the 11th, 13th, 15th, and 17th day. CPP was measured on the 18th day. It was found that morphine reexposured mice showed a decreased RACK1 level in the frontal cortex, striatum and an increased RACK1 level in hippocampus and NAcc, but this effect was reversed after administration of RACK1. In this study we demonstrated that RACK1 decreased p-ERK and erased CPP during reexposure of morphine and there was no an effect in reexposure saline mice. It strongly suggests that RACK1 may play a crucial role in morphine reexposured mice and the RACK1 has the potential to be a remedy to the morphine reward.

Exercise training improved insulin sensitivity and ovarian morphology in rats with polycystic ovary syndrome

Hyperandrogenism and hyperinsulinemia are major clinical features in women with polycystic ovary syndrome (PCOS). We hypothesized that serum insulin levels reduced by exercise could relieve hyperandrogenism and ameliorate polycystic ovarian morphology. Wistar female rats with 21-day-old were randomly divided into three groups: PCOS exercise (P-Ex), PCOS sedentary (P-Sed), and control sedentary (C-Sed). The rats with PCOS were induced by injection with testosterone propionate continuously. The exercise program was to swim with 120 min/d for two weeks. Fasting blood glucose (FBG) and insulin (FINS), estrogen (E (2)), progesterone (P), and testosterone (T) in serum were determined by RIA, and ovarian morphology was evaluated by Image-Pro Plus 6.0. The levels of FINS, E (2), and T in serum were significantly lower in P-Ex than in P-Sed. The ratios of FBG/FINS in P-Ex significantly increased in comparison with P-Sed. The levels of serum sex hormones in P-Ex were similar to C-Sed. There were no differences in blood glucose and serum progesterone among three groups. Ovarian morphology showed that the numbers of preantral follicles and atretic follicles significantly decreased, and the numbers of antral follicles and corpora lutea significantly increased in P-Ex compared with P-Sed. The changes of ovarian morphology in P-Ex were similar to C-Sed. These results demonstrated that short-term exercise training can improve insulin sensibility, decrease serum androgen levels, and recover normal ovarian morphology. The exercise training is the basic therapeutic means for PCOS.

An open-label expanded access study of lapatinib and capecitabine in patients with HER2-overexpressing locally advanced or metastatic breast cancer

BACKGROUND

The Lapatinib Expanded Access Program (LEAP) was designed to provide access to lapatinib plus capecitabine for HER2-positive metastatic breast cancer patients who previously received an anthracycline, a taxane, and a trastuzumab and had no other treatment options.

PATIENTS AND METHODS

LEAP opened globally and enrollment continued until lapatinib received regulatory approval in each participating country. Patients were assessed for progression-free survival (PFS) and overall survival (OS) and monitored for serious adverse events (SAEs).

RESULTS

As of 30 September 2008, 4283 patients from 45 countries enrolled in LEAP. The median treatment duration was 24.7 weeks. The most common drug-related SAEs were diarrhea (9.7%), vomiting (4.3%), and nausea (2.4%) and were mainly grade 3 or higher. The incidences of special interest SAEs were decreased left ventricle ejection fraction (0.5%), interstitial lung disease/pneumonitis (0.2%), and serious hepatobiliary events (0.4%). This safety profile is consistent with the overall lapatinib program. The median PFS and OS were 21.1 [95% confidence interval (CI) = 20.1-22.3] and 39.6 (95% CI = 37.7-40.7) weeks, respectively (n = 4006). Subgroup analysis showed longer PFS and OS in patients who had not received prior capecitabine.

CONCLUSIONS

These results demonstrate the safety and efficacy of lapatinib in a broader patient population compared with a clinical trial.

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]