Risk factors influencing the growth and survival of Campylobacter jejuni and Salmonella enterica on moisture enhanced pork

E.coli Biotype I, Campylobacter jejuni, or Salmonella enterica were inoculated into the surface of fresh pork loins and moisture enhanced with brine. After moisture enhancement, each pork loin was sliced into 1cm thick slices. All slices were randomly vacuum packed, stored at 4yC and 10yC and finally prepared using grilling practices .Studies were conducted to evaluate the potential microbiological concern presented by moisture enhanced pork (1) translocation of bacteria from the surface into the interior of the meat (2) effects of moisture enhancement on survival of bacteria in meat during storage (3) impact of moisture enhancement on survival of food borne pathogens during cooking. Our results showed that inoculated bacteria were translocated from the surface into the deep tissues in the boneless pork following moisture enhancement and slicing. Vacuum packing under chilled conditions can prevent the growth of Campylobacter jejuni and Salmonella enterica in enhanced pork. But it alone was not a substitute for safe handling and proper cooking because there were many numbers of Campylobacter jejuni and Salmonella enterica in enhanced pork during storage. The USDA recommended 160 yF as the safe minimum internal temperature for intact pork maybe also adequate for assuring the microbiological safety of moisture enhanced pork that is prepared without excessive contamination of interior tissues. Results were generally agreed that Campylobacter jejuni has more fastidious growth requirements and are more sensitive to various environment stresses than Salmonella enterica, such as vacuum packing, high cooking temperature. Compared to intact pork, moisture enhanced pork does not present a greater risk to consumers than otherwise similar meat that is intact, provided that the meat is properly cooked

Recent advances in arsenic trioxide encapsulated nanoparticles as drug delivery agents to solid cancers

Since arsenic trioxide (ATO) was first approved as the front line therapy for acute promyelocytic leukemia (APL) 25 years ago, its anti-cancer properties for various malignancies have been under intense investigation. However, the clinical successes of ATO in treating hematological cancers have not been translated to solid cancers. This is due to arsenic’s rapid clearance by the body’s immune system before reaching the tumor site. Several attempts have henceforth been made to increase its bioavailability toward solid cancers without increasing its dosage albeit without much success. This review summarizes the past and current utilization of ATO in the medical field with primary focus on the implementation of nanotechnology for ATO delivery to solid cancer cells. Different approaches that have been employed to increase arsenic’s efficacy, specificity and bioavailability to solid cancer cells were evaluated and compared. The potential of combining different approaches or tailoring delivery vehicles to target specific types of solid cancers according to individual cancer characteristics and arsenic chemistry was proposed and discussed

Effective delivery of arsenic trioxide to HPV-positive cervical cancer cells using optimised liposomes: a size and charge study

Despite the success of arsenic trioxide (ATO) in treating haematological malignancies, its potential to treat solid tumours has not been fully exploited, owing to its dose-limiting toxicity and poor pharmacokinetics. In order to overcome this hurdle, liposomal encapsulation of the drug with different surface charges (neutral, negative, and positive) and sizes (100, 200 and 400 nm) were synthesised and tested on human papilloma virus (HPV)-positive HeLa and HPV-negative HT-3 cervical cancer cell lines. Two epithelial cell lines-human keratinocytes (HK) and human colon cells (CRL-1790)-were used as controls. The synthesised liposomes were tested for their physico-chemical characteristics, drug loading efficiency, and toxicity on the studied cell lines. Neutral liposomes of 100 nm in size were the chosen formulation for delivering ATO into the studied cells, as they showed the least intrinsic cytotoxicity and the highest loading efficiency. The findings demonstrated that the optimised formulation of liposomes was an effective drug delivery method for HPV-infected cervical cancer cells. Furthermore, the toxicity vs. uptake ratio was highest for HeLa cells, while a reduced or minimal toxic effect was observed for non-HPV-infected cervical cancer cells and control cells. These findings may provide a promising therapeutic strategy for effectively managing cervical cancers

Estradiol, progesterone, testosterone profiles in human follicular fluid and cultured granulosa cells from luteinized pre-ovulatory follicles

BACKGROUND: The production of sex steroids by follicular cells is proposed to be influenced by the maturity of the incumbent oocyte. Thus steroid levels may reflect suitability of an oocyte for IVF. We examined follicular fluids and granulosa cell production of steroid from IVF patients in order to test the relationship between steroid levels and fertilization. METHODS: Follicular fluid and granulosa cells were extracted from 206 follicles of 35 women undergoing controlled ovarian stimulation. Follicular fluid was assayed for estradiol, progesterone and testosterone. Granulosa cells were cultured from individual follicles and their culture media assayed for production of these hormones after 24 hrs in vitro. Levels of steroids were correlated with follicular diameter, oocyte recovery and subsequent fertilization. RESULTS: Follicular fluid levels of progesterone were 6100 times higher than that of estradiol, and 16,900 times higher that of testosterone. Despite the size of follicle triggered after controlled luteinization, the levels of progesterone and testosterone were maintained at relatively constant levels (median 98.1 micromoles/L for progesterone, and 5.8 nanomoles/L for testosterone). However, estradiol levels were slightly lower in the larger follicles (follicular diameter 10-15 mm, median 25.3 nanomoles/L; follicles > = 15 mm, median 15.1 nanomoles/L; linear correlation r = -0.47, p < 0.0001). With respect to oocyte recovery, no steroid showed a significant association in follicular fluid levels. Similarly no difference in follicular fluid steroid levels was found for those oocytes that did or did not fertilize. Significant quantities of progesterone were produced by the granulosa cells but production was constant regardless of the size of follicle from which the cells originated. Estradiol levels were only detectable in 10 of 121 cultures examined, and testosterone in none. Interestingly, when an oocyte was present follicular estradiol levels correlated with progesterone levels. However, when absent, follicular estradiol levels correlated with testosterone levels but not with progesterone. CONCLUSIONS: The principle steroid product of luteinized pre-ovulatory granulosa is progesterone, a differentiation triggered by the gonadotropin surge. However, absolute steroid levels are associated with follicular size, not oocyte maturation/ability to fertilize

ESDA2008-59373 AN INVESTIGATION INTO EFFECT OF TRAIN CURVING ON WEAR AND CONTACT STRESSES OF WHEEL AND RAIL

ABSTRACT Some important papers concerning the studies on rail wear and wheel/rail contact stresses are reviewed. The present paper utilizes a numerical method to analyze the effect of railway vehicle curving on the wear and contact stresses of wheel/rail. The numerical method considers a combination of Kalker&apos;s non-Hertzian rolling contact theory, a material wear model and a vertical and lateral coupling dynamics model of a half vehicle and a curved track. The present analysis investigates the influence of the curving speed, the curved track super-elevation and the rail cant on the wear and the contact stresses. Through the detailed numerical analysis, it is found that the maximum contact stress depends greatly not only on the curving speed but also on the profiles of the wheel/rail. The curving speed increasing leads to increase the normal load of the wheel rolling over the high curved rail, but, decrease the normal contact stress level under the condition of the optimum match of wheel/rail profiles. The track super elevation increasing efficiently lowers the contact stresses and the wear at a constant curving speed. The rail cant has a great influence on the low rail wear of the curved track. Increasing the rail cant leads to the great growth of the low curved rail wear, the reduction in the high rail wear. The results are very useful in the maintenance of the track