Preservation and fermentation: past, present and future

Preservation of food and beverages resulting from fermentation has been an effective form of extending the shelf-life of foods for millennia. Traditionally, foods were preserved through naturally occurring fermentations, however, modern large scale production generally now exploits the use of defined strain starter systems to ensure consistency and quality in the final product. This review will mainly focus on the use of lactic acid bacteria (LAB) for food improvement, given their extensive application in a wide range of fermented foods. These microorganisms can produce a wide variety of antagonistic primary and secondary metabolites including organic acids, diacetyl, CO2 and even antibiotics such as reuterocyclin produced by Lactobacillus reuteri. In addition, members of the group can also produce a wide range of bacteriocins, some of which have activity against food pathogens such as Listeria monocytogenes and Clostridium botulinum. Indeed, the bacteriocin nisin has been used as an effective biopreservative in some dairy products for decades, while a number of more recently discovered bacteriocins, such as lacticin 3147, demonstrate increasing potential in a number of food applications. Both of these lactococcal bacteriocins belong to the lantibiotic family of posttranslationally modified bacteriocins that contain lanthionine, beta-methyllanthionine and dehydrated amino acids. The exploitation of such naturally produced antagonists holds tremendous potential for extension of shelf-life and improvement of safety of a variety of foods.

A novel selective medium for the detection of methicillin-resistant Staphylococcus aureus enabling result reporting in under 24 h

A simple selective broth was devised to indicate the presence of methicillin resistant Staphylococcus aureus (MRSA) in clinical samples. The broth comprised nutrient broth supplemented with sodium chloride, ciprofloxacin, colistin and aztreonam as selective agents and also mannitol, trehalose and phenol red as an indicator system. In a preliminary study using 228 clinical samples this selective mannitol broth (SMB) proved to be more sensitive than other selective agars for detection of MRSA within 24 h. In an extended study of a further 1124 clinical samples from 470 randomly selected patients, SMB detected 85.1% of MRSA strains present with a specificity of 43.6%. We conclude that SMB offers a convenient, inexpensive and sensitive method for high-throughput screening for MRSA.

A study comparing various noninvasive methods of detecting bladder cancer in urine

OBJECTIVES

To compare the nuclear matrix protein (NMP)-22 assay, bladder tumour specific antigen (BTAstat) test, telomerase activity (using the telomeric repeat amplification protocol assay, TRAP) and a haemoglobin dipstick test for their ability to replace voided urine cytology (VUC) for detecting bladder cancer.

PATIENTS AND METHODS

The study included 120 urological patients prospectively recruited and assessed before surgery. A single freshly voided urine sample (approximate 100 mL) was collected from each patient and aliquoted for each test. All assays were conducted according to the manufactures' guidelines; 79 patients were tested for telomerase activity. The results were then compared with VUC and the diagnosis confirmed by cystoscopy and histology.

RESULTS

Fifty-two patients had histologically confirmed transitional cell carcinoma. The overall sensitivity for BTAstat, NMP22, telomerase, VUC and dipstick testing was 63%, 81%, 84%, 48% and 50%, respectively. Combining the results for telomerase and NMP22 gave a sensitivity of 100%. For G1 tumours the respective sensitivities were 23%, 62%, 56%, 23% and 15%, for G2 tumours, 68%, 86%, 92%, 50% and 41% and for G3 tumours 88%, 88%, 100%, 71% and 82%. For pTa tumours the respective detection rates were 48%, 70%, 84%, 39% and 30%, for pT1 tumours 80%, 90%, 90%, 50% and 50%, for pT2/pTis tumours, 100/100%, 100/100%, 100/100%, 88/100% and 88/83%. The overall specificity for the respective tests was 82%, 87%, 93%, 87% and 54%; combining the results of NMP22 and telomerase activity increased the specificity to 96%.

CONCLUSIONS

There was significantly better detection than VUC when using the NMP22 and TRAP assay, especially for well-differentiated (P < 0.001 and 0.0027, respectively) and superficial tumours (P < 0.001 and 0.034, respectively). Combining the results of NMP22 and telomerase activity yielded values comparable with cystoscopy.

4-aminopyridine poisoning of crows in the Chicago area

Poisoning of crows with the avicide 4-aminopyridine is reported. Seven crows had frequent vocalization and nervous signs; 6 died. Postmortem examination of 4 found evidence of trauma and corn-based bait present in the gastrointestinal tract. The bait contained 4-aminopyridine, a rapidly fatal nervous system toxin. When utilized by pest control professionals using manufacturer's recommendations, 4-aminopyridine has little risk of direct or relay toxicosis to non-target species. Treatment of exposed individuals involves symptomatic care and control of seizures.

The problems of aggression and violence for health-care staff

Nurses frequently face violent and aggressive behaviour in the course of their daily work. Staff working in accident and emergency departments report the highest incidence of verbal and physical aggression and actual violence. This literature review examines the problem and highlights advice available on defusing potentially dangerous situations at work.

Pharmacological characterization of a novel factor Xa inhibitor, FXV673

FXV673 is a novel, potent, and selective factor Xa (FXa) inhibitor. FXV673 inhibited human, dog, and rabbit FXa with a K(i) of 0.52, 1.41, and 0.27 nM, respectively. FXV673 also displayed excellent specificity toward FXa relative to other serine proteases. It showed selectivity of more than 1000-fold over thrombin, activated protein C (aPC), plasmin, and tissue-plasminogen activator (t-PA). FXV673 prolonged plasma activated partial thromboplastin time (APTT) and prothrombin time (PT) in a dose-dependent fashion. In the APTT assays, the concentrations (microM) required for doubling coagulation time were 0.41 (human), 0.65 (monkey), 1.12 (dog), 0.25 (rabbit), and 0.80 (rat). The concentrations (microM) required in the PT assays were 1.1 (human), 1.32 (monkey), 2.31 (dog), 0.92 (rabbit), and 1.69 (rat). A coupled-enzyme assay was performed to measure thrombin activity following prothrombinase conversion of prothrombin to thrombin. FXV673 showed IC(50)s of 1.38 and 2.55 nM, respectively, when artificial phosphatidylserine/phosphatidylcholine (PS/PC) liposomes or fresh platelets were used as the phospholipid source for prothrombinase complex formation. It was demonstrated that FXV673 could inhibit further thrombin generation in the prothrombinase complex using PS/PC liposomes. FXV673 dose-dependently prolonged the time to vessel occlusion and inhibited thrombus formation in well-characterized canine models of thrombosis. Interspecies extrapolation (approximately 2.5-fold higher sensitivity for FXa inhibition in human than in dog) suggested that 100 ng/ml of FXV673 would be an effective plasma concentration for clinical studies. Currently FXV673 is undergoing clinical studies to be developed as an antithrombotic agent.

Diagnosing coeliac disease by rectal gluten challenge: a prospective study based on immunopathology, computerized image analysis and logistic regression analysis

The purpose of this study was to evaluate the use of rectal gluten challenge in the diagnosis of coeliac disease. A total of 103 patients with features suggestive of this diagnosis were prospectively enrolled into the study; a diagnosis of coeliac disease was based on strictly defined criteria used in judging the proximal jejunal biopsy. On that basis, 45 out of the 103 patients were deemed to have coeliac disease. A slurry of gluten powder in physiological saline was introduced into the rectum, and biopsies taken before and at 2 h or 4 h after the challenge were examined immunohistochemically by computerized image analysis. Cell counts were analysed by logistic regression, and the best equations were obtained for each challenge group. The 2 h challenge yielded diagnostic sensitivity and specificity of 69.6% and 78.6% respectively. The 4 h challenge provided sensitivity and specificity of 100% and 100% respectively. These results were compared with other clinical diagnostic predictors,including anti-endomysial antibodies, which yielded diagnostic sensitivity and specificity of 70% and 98% respectively. It is concluded that a 4 h rectal challenge is a highly sensitive means of identifying gluten-sensitized individuals, and would be of particular value in cases showing negative antibody screening or equivocal biopsy appearances.

Targeted intra-operative radiotherapy (Targit): an innovative method of treatment for early breast cancer

INTRODUCTION

We believe that conservative treatment of early breast cancer may not require radiotherapy that encompasses the whole breast. We present here the clinico-pathological basis for this view, as well as a novel therapeutic approach that allows intra-operative radiotherapy to be safely and accurately delivered to the target tissues in a standard operating theatre. THE RATIONALE: Whole-organ analysis of mastectomy specimens reveals that 80% of occult cancer foci are situated remote from the index quadrant. In contrast, over 90% of local recurrences after breast conservative therapy occur near the original tumour, even when radiotherapy is not given. Therefore, the remote occult cancer foci may be clinically irrelevant and radiotherapy to the index quadrant alone might be sufficient. A NOVEL TECHNIQUE: The Photon Radiosurgery System (PRS) is an ingenious portable electron-beam driven device that can typically deliver intra-operative doses of 5-20 Gy, respectively, to 1 cm and 0.2 cm from the tumour bed over about 22 min. The pliable breast tissue--the target--wraps around the source, providing perfect conformal radiotherapy. Being soft X-rays, the dose attenuates rapidly (alpha approximately 1/r3), reducing distant damage.

RESULTS

In our pilot study of 25 patients (age 30-80 years, T = 0.42-4.0 cm), we replaced the routine post-operative tumour bed boost with targeted intra-operative radiotherapy. There have been no major complications and no patient has developed local recurrence, although the median follow-up time is short, at 24 months.

CONCLUSION

It is safe and feasible to deliver targeted intraoperative radiotherapy (Targit) for early breast cancer. We have begun a randomised trial--the first of its kind--comparing Targit with conventional six-week course of radiotherapy. If proven equivalent in terms of local recurrence and cosmesis, it could eliminate the need for the usual six-week course of post-operative radiotherapy.

Driving and dementia: a review of the literature

In North American society driving is closely linked with independence. Unfortunately, the freedom to operate a motor vehicle may be lost when an individual develops a specific medical diagnosis. The complex issue of dementia and driving safety is frequently encountered by health care professionals. Physicians are required, by law, to report any medical diagnosis such as dementia, that may affect driving safety. Physicians often refer to occupational therapists to assist them in determining if an individual's impairment significantly impacts driving safety. Unfortunately many health care professionals are not using reliable, valid and sensitive tests to determine the point at which an individual with dementia will become an unsafe driver. Through a review of the literature, the authors explore the effects of normal aging and cognitive impairment on driving safety. Specific assessment tools used to assess driving ability are examined and the role of health professionals in driver assessment is discussed. Some suggestions to improve the overall approach to evaluating driving safety are offered in the conclusion.

Effects of ground EMS and ED personnel on air medical trauma on-site times

INTRODUCTION

On-site times for helicopter EMS (HEMS) providers are hypothesized to increase when procedures indicated by national standards of care and local HEMS are not consistently completed by ground EMS (GEMS) or ED providers before HEMS arrival in trauma cases.

METHODS

In this prospective study, we divided all trauma missions (120) flown by a university-based HEMS during a 3-month period into interfacility missions (between hospitals, ground providers are ED personnel) and scene missions (between scenes and hospitals, ground providers are GEMS). HEMS completed forms identifying which procedures were completed and omitted by GEMS or ED providers. We collected relevant times from county dispatchers and HEMS flight control.

RESULTS

Ground providers frequently did not complete indicated basic and advanced procedures. A relationship existed between scene GEMS omissions and HEMS on-site times. If no procedures were omitted, average HEMS time on-site was 13 minutes, increasing to 17 minutes for one procedure omitted and 20 minutes for two or more. No relationship was found on interfacility missions between ED provider omissions and HEMS on-site times. However, any existing effect may have been eclipsed by external factors significantly extending HEMS on-site times (mean 43 minutes). An average of 93 minutes elapsed between the request for HEMS transport and patient arrival at the transferring hospital.

CONCLUSION

GEMS frequently omit indicated procedures. For scene missions, reducing the number of indicated procedures omitted by scene GEMS providers could reduce on-site HEMS times. For interfacility missions, further study is indicated to determine what occurs before HEMS is contacted and while HEMS is on-site.

Evidence for a dissociation between MPTP toxicity and tyrosinase activity based on congenic mouse strain susceptibility

The neurotoxicity induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is one of the most valuable available models for investigating critical aspects of human Parkinson's disease. In order to analyze the relevance of pigmentation for MPTP sensitivity, we compared C57Bl/6 wild-type mice with the albino mutant C57Bl/6J-Tyr(c-2J) of the same strain. These animals were treated either with systemic MPTP or with saline and were examined in behavioral tests. Seven days after treatment, the contents of dopamine and other monoamines were determined postmortem in the neostriatum and ventral striatum. Furthermore, the numbers of tyrosine hydroxylase-positive cells were counted in the substantia nigra and ventral tegmental area. Open field testing showed that rearing activity was drastically reduced as an acute effect of MPTP in both wild type and mutants; however, subsequent recovery to control levels was faster in wild-type mice. Nest building also indicated strain-dependent effects, since it was delayed only in mutants treated with MPTP. Neurochemically, MPTP led to severe neostriatal dopamine depletions, which did not differ significantly between wild-type (72.9%) and mutant mice (82.1%). Less severe dopamine depletions were also found in the ventral striatum. Histologically, a loss of tyrosine hydroxylase-labeled cells was observed only in the substantia nigra of both wild-type and mutant mice (13.3 and 21.3%, respectively), but not in the ventral tegmental area. Together, our data do not provide evidence that tyrosinase-deficient mice are less affected by MPTP treatment than the comparable wild type, thus arguing strongly against the hypothesis that enhanced MPTP sensitivity in pigmented mouse strains is caused by tyrosinase activity.

Parental health beliefs and compliance with prophylactic penicillin administration in children with sickle cell disease

PURPOSE

Prophylactic penicillin is effective in preventing severe invasive pneumococcal infection in children with sickle cell disease. In some families, compliance has been problematic. The aims of this study were to monitor compliance and to assess the efficacy of the Health Belief Model (HBM) in predicting compliance.

METHODS

Fifty mothers of children with sickle cell disease, ages 6 to 60 months, participated in the study. On enrollment, mothers completed surveys assessing their health beliefs regarding sickle cell disease and infections. Compliance was assessed through self-reporting by the mothers and through review of local pharmacy records of penicillin refills.

RESULTS

Sixty percent of the mothers reported that they were highly compliant with obtaining the prescribed 14-day refills. Pharmacy records indicated that only 12% actually adhered to this schedule. The self-reports were significantly related to compliance ratings; mothers who admitted less than optimal compliance averaged 42 days between refills, compared with 19 days for mothers who reported good compliance. Varying perceptions identified through the HBM accounted for approximately 30% of the variance in compliance rates. The perceived burdens of picking up the refills and remembering to administer the medication were the most significant factors.

CONCLUSIONS

Educational efforts alone are not sufficient to ensure compliance with penicillin prophylaxis. Routinely monitoring compliance through pharmacy records, reviewing parental beliefs about sickle cell disease and infections, and exploring barriers to treatment will promote dialogue about the importance of strict compliance with this relatively simple yet life-saving prophylaxis.

The adolescent with cancer--at the edge of no-man's land

The cancer journey of the adolescent patient can be difficult and lonely. Provision of services to these patients should occur at the interface between paediatric and adult oncology, although for the individual, that interface can seem like a gap into which he or she may too readily fall. In the UK, the needs of adolescent patients have become more widely recognised in the past decade, but they continue to have a low priority on the national agenda. Recent guidelines on cancer referral made specific reference to children's cancers, but none to cancer in adolescents. The need for dedicated services for these patients has been accepted, but the resources to meet this need have rarely been identified. We explore current and future patterns of care and service provision for adolescents with cancer in the UK.

Controlling the phase response of a diffusive wave phased array system

Previous phased array research using anti-phase sources has shown that the phase response to an object scanned through a heavily scattering medium provides information about object position but none about size. In this paper it is demonstrated that controlling the relative phase between the sources enables different phase gradients to be set within the medium. The consequence of this is that the phase response is dependent on the size of an object whilst still maintaining localization information. Furthermore, it is demonstrated that the phase response can be tuned to be most sensitive to the object size under investigation.

Polarization properties of light backscattered from a two layer scattering medium

The polarization properties of light backscattered from a two layer scattering medium are investigated. Linear, circular and elliptical polarization states are considered and it is demonstrated that the degree of polarization of the backscattered light is sensitive to the optical properties of both layers and to layer thickness. Furthermore, it is shown that the polarization memory of circularly polarized light enables deeper layers to be probed whereas linearly polarized light is more sensitive to surface layers. This has applications for characterizing burns and melanoma.