No abstract

High pressure has been studied for its usefulness in reducing microbial contaminants in foods. We sought to determine whether this technology could be used in combination with irradiation to develop shelf-stable products. We first determined the optimal pressure, temperature, and time conditions that would result in maximum reduction of Clostridium sporogenes spores in fresh chicken. At ambient temperature, a pressure of 6,800 atm for up to 60 min resulted in a 5-log-unit reduction. Heating the samples during pressurization at 80°C for 20 min resulted in the lowest number of survivors compared to samples that were heated and pressurized for only 1 and 10 min. Further, irradiation at a medium dose (3.0 kGy) before and after pressurization at 6,800 atm and 80°C for 1, 10, and 20 min revealed no significant differences in spore counts between samples that were pressurized and then irradiated or vice-versa. We then examined the effect of high pressure in lowering the irradiation dose necessary to eliminate all spores. The irradiation D value of C. sporogenes spores was calculated to be 4.1 kGy. Samples were then irradiated at various doses followed by pressurization at 6,800 atm at 80°C for 20 min. The irradiation D value was lowered to approximately 2 kGy, indicating that a combination of high hydrostatic pressure and irradiation can be used to produce chicken with an extended shelf life without the use of high irradiation doses.

Irradiation sensitivity of five Salmonella enteritidis isolates inoculated either on the surface or inside of whole shell eggs were determined. The shell eggs were irradiated at doses of 0, 0.5, 1.0, and 1.5 kGy. A minimal dose of 0.5 kGy was sufficient to eliminate all the isolates from the surface of whole eggs; however, the same isolates were more resistant to irradiation when present inside the eggs. The ATCC 13076 isolate was significantly more sensitive to irradiation, with a D value of 0.32 kGy, than the other four isolates from animal origin. Irradiation D values of the latter ranged from 0.39 to 0.41 kGy. Liquid whole eggs were also inoculated (2.4 x 10(6) cells per milliliter) with two S. enteritidis isolates and were heat-treated at 50 C for 0, 20, 40, or 60 min followed by irradiation at 0, 0.25, 0.5, 0.75, or 1.0 kGy. The results indicate that mild heating prior to irradiation was ineffective in reducing the irradiation D values. However, on the basis of the D values obtained, an irradiation dose of 1.5 kGy should be sufficient to reduce Salmonella counts by approximately 4 log10 in both whole shell and liquid eggs. Results also indicate that color and thermal characteristics of the whole or liquid eggs were unaffected by a 1.5-kGy dose of irradiation.

Background: In HER2 over-expressing breast cancer cells, the HER2 protein can be cleaved by a metalloproteinase, ADAM10. While the extracellular domain (ECD) of HER2 is released into the serum, the truncated HER2 receptor fragment, termed p95, remains in the tumor cell membrane as a constitutively active receptor tyrosine kinase. Previous studies have shown that the presence of p95 in tumor cells is associated with poor clinical outcomes in patients with metastatic HER2 positive breast cancer and it was recently shown that patients with p95+ HER2 positive breast cancer are resistant to trastuzumab-based therapy. Therefore, inhibition of HER2 cleavage by the ADAM10/ADAM17 inhibitor, INCB7839, which reduces the formation of soluble HER2 ECD as well as p95 levels in the tumor, may enhance the clinical efficacy of trastuzumab in HER2+ breast cancer patients. Materials and Methods: This study is a single arm modified dose escalation open label trial of INCB7839 + trastuzumab in women with HER2+ metastatic breast cancer, naïve to chemotherapy. Three doses of INCB7839 were studied (100 mg, 200 mg, 300 mg BID) with 6 patients/cohort and an expansion arm at the 300mg BID dose. Herceptin was administered on a Q3 week schedule. Pharmacokinetics, plasma HER2 ECD levels and p95 expression in tumor tissue were assessed in addition to clinical response and safety. Results: 39 patients have been enrolled in the study and assessment of HER2 ECD levels, p95 status and best clinical response completed on 30 patients. INCB7839 administration results in a dose-dependent reduction in the elevated levels of circulating HER2 ECD with a mean of ∼80% inhibition achieved at the highest dose tested (300 mg BID). At the 300mg BID dose, the current overall response rate is 40% (6/15 evaluable patients) with a higher response rate (6/11 or 55%) observed in patients with average plasma concentrations of INCB7839 above the IC50 for reduction of ECD levels, 320nM. Importantly, INCB7839 increases the clinical response rate in p95+ patients, with equivalent responses observed in the p95+ and p95- patients treated with INCB7839 + trastuzumab. The combination has been generally safe and well tolerated. Discussion: Proteolytic cleavage of the HER2 receptor by ADAM proteases results in the formation of a cytoplasmic fragment (p95) that possesses constitutive kinase activity with the release of ECD. Importantly, elevated levels of ECD and/or p95 have been associated with poor prognosis and clinical data suggest that p95 affords resistance to trastuzumab. Biomarker and clinical data from this trial demonstrate that INCB7839 can markedly reduce HER2 cleavage in patients with HER2+ breast cancer, and suggests that INCB7839, by inhibiting the HER2 shedding process, can render a subpopulation of HER2+ patients (as defined by the presence of p95) that would be predicted to be trastuzumab resistant clinically responsive to trastuzumab therapy. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5056.

The optimum conditions required to induce a heat-shock response in Yersinia enterocolitica in brain heart infusion (BHI) broth were determined. The production of heat-shock proteins and the increased thermotolerance of heat-shocked Yersinia cells in ground pork when exposed to higher temperatures was also examined. Heat shocking Y. enterocolitica cells at 45°C for 60 min consistently resulted in an increased number of survivors to a subsequent treatment of 55 or 60°C in BHI broth when compared with non-heat-shocked controls. D values at 55°C were calculated as 7.7 and 2.0 min and at 60°C as 1.6 and 1.2 min for heat-shocked and control cells, respectively. After examination of heat-shocked cells by sodium dodecyl sulfate-polyacrilamide gel electrophoresis (SDS-PAGE), two distinct heat-shock proteins with molecular masses of 70.5 and 58.0 kDa were observed that were not present in the control. Evaluation of heat-shocked and control cell survival in ground pork revealed D55 values of 15.6 and 6.5 min and D60 values of 6.7 and 1.7 min, respectively. The results indicate that prior heat shock can induce increased resistance in Y. enterocolitica in ground pork to higher heat treatments. Survival of Yersinia enterocolitica in cooked meat due to the phenomenon of the heat-shock response can become a cause of concern regarding microbiological food safety.

No abstract

Nardostachys jatamansi is traditionally used in alternative medicine for treatment of neuropsychiatric disorders. We investigated the potential of N. jatamansi extract (NJE) in protecting against chronic stress-induced impairments in spatial learning and memory. The rats were exposed to 21 days of chronic restraint stress and simultaneously received 100 mg or 200 mg/kg body weight of NJE following which acquisition and retention of hippocampus-dependent spatial memory were tested in a partially-baited eight arm radial maze. Animals treated with 200 mg/kg body weight NJE had learning curves comparable to control unstressed animals, made significantly more correct choices (38%, P < 0.001), and fewer reference memory errors (53%, P < 0.01) on the eighth day of training compared to untreated stressed animals as well as stressed animals which received vehicle or a lower dose (100 mg/kg) of NJE. NJE-treated animals also made significantly higher correct choices (31%, P < 0.001) than untreated animals in a retention test 10 days after the training period. We propose that NJE has a protective effect of stress-induced impairments in hippocampus-dependent learning and memory behavior in rats.

Ground pork patties were inoculated separately with 10(9) CFU/g each of three strains of Listeria monocytogenes obtained from the National Animal Disease Center (NADC). Inoculated patties were packaged under vacuum and treated at 414 megapascals (60,000 lb/in2) for up to 60 min by high hydrostatic pressure (HHP). Survivors were determined by surface plating onto modified Oxford agar and trypticase soy agar with yeast extract, as well as by the most probable number method using Listeria enrichment broth. Average D values ranged from 1.89 to 4.17 min, depending on the strain, with the most virulent strain (reported by the NADC) having the highest D value. We tested the usefulness of applying a mild heat treatment at 50 degrees C, simultaneously with HHP, to lower these values. Average D values ranged from 0.37 to 0.63 min, depending on the strain. Thus, a 10-log10 reduction could be achieved even in the most pressure-resistant strain of L. monocytogenes by a 6-min application of heat and HHP. Shelf life studies were also conducted, with spoilage levels reached after 5 days of storage at 4 degrees C for controls versus 28 days for treated samples. Sensory evaluation of uninoculated grilled patties showed that panelists could not distinguish between those treated by heat and HHP and untreated controls (P<0.05). Thus, treatment by HHP in combination with mild heating can be used successfully to produce safer, longer-lasting fresh pork without affecting quality.