Verification of an alternative sludge treatment process for pathogen reduction at two wastewater treatment plants in Victoria, Australia.

At South East Water wastewater treatment plants (WwTPs) in Victoria, Australia, biosolids are stockpiled for three years in compliance with the State guidelines to achieve the highest pathogen reduction grade (T1), suitable for unrestricted use in agriculture and landscaping. However, extended stockpiling is costly, may increase odour nuisance and greenhouse gas emissions, and reduces the fertiliser value of the biosolids. A verification programme of sampling and analysis for enteric pathogens was conducted at two WwTPs where sludge is treated by aerobic and anaerobic digestion, air drying (in drying pans or solar drying sheds) and stockpiling, to enumerate and, if present, monitor the decay of a range of enteric pathogens and parasites. The sludge treatment processes at both WwTPs achieved T1 grade biosolids with respect to prescribed pathogenic bacterial numbers (<1 Salmonella spp. 50 g-1 dry solids (DS) and <100 Escherichia coli g-1 DS) and >3 log10 enteric virus reduction after a storage period of one year. No Ascaris eggs were detected in the influent to the WwTPs, confirming previous studies that the presence of helminth infections in Victoria is extremely low and that Ascaris is not applicable as a control criterion for the microbiological quality of biosolids in the region.

Nitrogen availability and indirect measurements of greenhouse gas emissions from aerobic and anaerobic biowaste digestates applied to agricultural soils.

Recycling biowaste digestates on agricultural land diverts biodegradable waste from landfill disposal and represents a sustainable source of nutrients and organic matter (OM) to improve soil for crop production. However, the dynamics of nitrogen (N) release from these organic N sources must be determined to optimise their fertiliser value and management. This laboratory incubation experiment examined the effects of digestate type (aerobic and anaerobic), waste type (industrial, agricultural and municipal solid waste or sewage sludge) and soil type (sandy loam, sandy silt loam and silty clay) on N availability in digestate-amended soils and also quantified the extent and significance of the immobilisation of N within the soil microbial biomass, as a possible regulatory mechanism of N release. The digestate types examined included: dewatered, anaerobically digested biosolids (DMAD); dewatered, anaerobic mesophilic digestate from the organic fraction of municipal solid waste (DMADMSW); liquid, anaerobic co-digestate of food and animal slurry (LcoMAD) and liquid, thermophilic aerobic digestate of food waste (LTAD). Ammonium chloride (NH4Cl) was included as a reference treatment for mineral N. After 48 days, the final, maximum net recoveries of mineral N relative to the total N (TN) addition in the different digestates and unamended control treatments were in the decreasing order: LcoMAD, 68%; LTAD, 37%, DMAD, 20%; and DMADMSW, 11%. A transient increase in microbial biomass N (MBN) was observed with LTAD application, indicating greater microbial activity in amended soil and reflecting the lower stability of this OM source, compared to the other, anaerobic digestate types, which showed no consistent effects on MBN compared to the control. Thus, the overall net release of digestate N in different soil types was not regulated by N transfer into the soil microbial biomass, but was determined primarily by digestate properties and the capacity of the soil type to process and turnover digestate N. In contrast to the sandy soil types, where nitrate (NO3-) concentrations increased during incubation, there was an absence of NO3- accumulation in the silty clay soil amended with LTAD and DMADMSW. This provided indirect evidence for denitrification activity and the gaseous loss of N, and the associated increased risk of greenhouse gas emissions under certain conditions of labile C supply and/or digestate physical structure in fine-textured soil types. The significance and influence of the interaction between soil type and digestate stability and physical properties on denitrification processes in digestate-amended soils require urgent investigation to ensure management practices are appropriate to minimise greenhouse gas emissions from land applied biowastes.

Land application of sewage sludge (biosolids) in Australia: risks to the environment and food crops.

Australia is a large exporter of agricultural products, with producers responsible for a range of quality assurance programs to ensure that food crops are free from various contaminants of detriment to human health. Large volumes of treated sewage sludge (biosolids), although low by world standards, are increasingly being recycled to land, primarily to replace plant nutrients and to improve soil properties; they are used in agriculture, forestry, and composted. The Australian National Biosolids Research Program (NBRP) has linked researchers to a collective goal to investigate nutrients and benchmark safe concentrations of metals nationally using a common methodology, with various other research programs conducted in a number of states specific to regional problems and priorities. The use of biosolids in Australia is strictly regulated by state guidelines, some of which are under review following recent research outcomes. Communication and research between the water industry, regulators and researchers specific to the regulation of biosolids is further enhanced by the Australian and New Zealand Biosolids Partnership (ANZBP). This paper summarises the major issues and constraints related to biosolids use in Australia using specific case examples from Western Australia, a member of the Australian NBRP, and highlights several research projects conducted over the last decade to ensure that biosolids are used beneficially and safely in the environment. Attention is given to research relating to plant nutrient uptake, particularly nitrogen and phosphorus (including that of reduced phosphorus uptake in alum sludge-amended soil); the risk of heavy metal uptake by plants, specifically cadmium, copper and zinc; the risk of pathogen contamination in soil and grain products; change to soil pH (particularly following lime-amended biosolids); and the monitoring of faecal contamination by biosolids in waterbodies using DNA techniques. Examples of products that are currently produced in Western Australia from sewage sludge include mesophilic anaerobically digested and dewatered biosolids cake, lime-amended biosolids, alum sludge and compost.

Caring for stroke survivors: baseline and 1-year determinants of caregiver burden.

BACKGROUND: Caregiver burden following stroke can have significant adverse health consequences for caregivers and threatens the recovery and successful rehabilitation of patients. Our objective was to identify patient factors that contribute to higher levels of caregiver burden. METHODS: We prospectively studied patients admitted to our stroke unit over a 2-year period (2001-2002). Data were collected at baseline and at 1 year. Caregiver burden was measured at 1 year using the Relatives Stress Scale (completed by 155 caregivers) and the Bakas Caregiver Outcomes Scale (143 caregivers). Explanatory patient factors at baseline included sociodemographic status, stroke severity, stroke sub-type, functional disability (Barthel Index), functional handicap (Oxford Handicap Scale and Modified Rankin Scale), and cognitive status (orientation, clock drawing). At 1 year, mental health and health-related quality of life were assessed using the Fatigue Impact Scale, Geriatric Depression Scale, Global Deterioration Scale, and 36-item Short Form Health Survey. RESULTS: The baseline patient factors predictive of caregiver burden by multiple regression analysis were older patient age (P<0.01), male gender (P<0.05), ischemic stroke (P<0.05), urinary incontinence (P<0.0001), and impaired clock drawing (P<0.05). At 1 year, significant correlates of caregiver burden were older patient age (P<0.05), male gender (P<0.01), poor mental health (P<0.05), functional handicap (P<0.05), and functional disability (P<0.001). CONCLUSIONS: The functional status of patients can be used to identify caregivers at risk of caregiver burden. Patient demographic variables, cognitive function, and mental health status may further expose vulnerable caregivers. These factors should be considered in the development of strategies to offset caregiver burden.

A systematic review of caregiver burden following stroke.

Abstract Caregiver burden following stroke is increasingly recognised as a significant health care concern. A growing number of studies have evaluated the patient, caregiver, and social support factors that contribute to increased caregiver burden. We conducted a systematic review of this literature to guide future research. A search of the MEDLINE, PsycINFO, CINAHL, and EMBASE databases (up to July 2008) and reference sections of published studies using a structured search strategy yielded 24 relevant articles. Studies were included if they evaluated predictors and/or correlates of caregiver burden in the setting of stroke. The prevalence of caregiver burden was 25-54% and remained elevated for an indefinite period following stroke. In studies that evaluated independent baseline predictors of subsequent caregiver burden, none of the factors reported were consistent across studies. In studies that assessed concurrent factors independently contributing to caregiver burden in the poststroke period, patient characteristics and social support factors were inconsistently reported. Several studies identified caregiver mental health and the amount of time and effort required of the caregiver as significant determinants of caregiver burden. Our findings highlight the need for more research to identify caregivers in need of support and guide the development and implementation of appropriate interventions to offset caregiver burden.

Giant bathing trunk naevus with lymphadenopathy and unusual pathology.

Giant congenital melanocytic naevi remain a challenge to clinicians and histopathologists with respect to observation for malignant change and interpretation of histology findings, respectively. We report a 5-year-old boy with a giant bathing trunk naevus who, after multiple previous skin biopsies, developed lymphadenopathy. Biopsy from the lymph nodes demonstrated collections of naevomelanocytes within the lymph node. Interpretation of these findings and subsequent management is discussed.

Expression of VEGF(xxx)b, the inhibitory isoforms of VEGF, in malignant melanoma.

Malignant melanoma is the most lethal of the skin cancers and the UK incidence is rising faster than that of any other cancer. Angiogenesis - the growth of new vessels from preexisting vasculature - is an absolute requirement for tumour survival and progression beyond a few hundred microns in diameter. We previously described a class of anti-angiogenic isoforms of VEGF, VEGF(xxx)b, that inhibit tumour growth in animal models, and are downregulated in some cancers, but have not been investigated in melanoma. To determine whether VEGF(xxx)b expression was altered in melanoma, PCR and immunohistochemistry of archived human tumour samples were used. In normal epidermis and in a proportion of melanoma samples, VEGF(xxx)b staining was seen. Some melanomas had much weaker staining. Subsequent examination revealed that expression was significantly reduced in primary melanoma samples (both horizontal and vertical growth phases) from patients who subsequently developed tumour metastasis compared with those who did not (analysis of variance (ANOVA) P<0.001 metastatic vs nonmetastatic), irrespective of tumour thickness, while the surrounding epidermis showed no difference in expression. Staining for total VEGF expression showed staining in metastatic and nonmetastatic melanomas, and normal epidermis. An absence of VEGF(xxx)b expression appears to predict metastatic spread in patients with primary melanoma. These results suggest that there is a switch in splicing as part of the metastatic process, from anti-angiogenic to pro-angiogenic VEGF isoforms. This may form part of a wider metastatic splicing phenotype.

Collagenosis Nuchae: a case report of a rare and often misdiagnosed condition.

Enzinger and Weiss first described Collagenosis Nuchae (CN) or nuchal fibroma (NF) in 1988. CN is a rare benign soft tissue tumour that arises from the posterior cervical subcutaneous tissue with predilection for the interscapular and paraspinal regions. It is more common in males. CN has been reported in association with trauma, diabetes, scleredema and Gardner's syndrome. The true incidence of CN is probably higher than recognised and CN should be in the differential diagnosis of head and neck lesions. Histological examination is required for the diagnosis. Careful total excision provides cure and accurate diagnosis. The purpose of this study is to review the epidemiological, clinical, histopathological and radiological features of this rare lesion, which is often misdiagnosed.

Chemokine-mediated migration of melanoma cells towards lymphatics--a mechanism contributing to metastasis.

The mechanisms that cause tumors such as melanomas to metastasize into peripheral lymphatic capillaries are poorly defined. Non-mutually-exclusive mechanisms are lymphatic endothelial cell (LEC) chemotaxis and proliferation in response to tumor cells (chemotaxis-lymphangiogenesis hypothesis) or LECs may secrete chemotactic agents that attract cancer cells (chemotactic metastasis hypothesis). Using migration assays, we found evidence supporting both hypotheses. Conditioned medium (CM) from metastatic malignant melanoma (MMM) cell lines attracted LEC migration, consistent with the lymphangiogenesis hypothesis. Conversely, CM from mixed endothelial cells or LECs, but not blood endothelial cells, attracted MMM cells but not non-metastatic melanoma cells, consistent with the chemotactic metastasis hypothesis. MMM cell lines expressed CCR7 receptors for the lymphatic chemokine CCL21 and CCL21 neutralizing antibodies prevented MMM chemotaxis in vitro. To test for chemotactic metastasis in vivo tumor cells were xenotransplanted into nude mice approximately 1 cm from an injected LEC depot. Two different MMM grew directionally towards the LECs, whereas non-metastatic melanomas did not. These observations support the hypothesis that MMM cells grow towards regions of high LEC density owing to chemotactic LEC secretions, including CCL21. This chemotactic metastasis may contribute to the close association between metastasizing tumor cells and peri-tumor lymphatic density and promote lymphatic invasion.

Multiple malignant melanomas in association with neurofibromatosis type 1.

We present a case of multiple primary malignant melanomata occurring over a six year period in a 63-year-old Caucasian man with neurofibromatosis type 1. There is doubt regarding a definite association between these two diseases despite a number of case reports and clear, potential pathological mechanisms. This case not only strengthens support for an association but also highlights the great difficulties that arise in the management of cutaneous melanomata in patients with neurofibromatosis.

Lymphatic density and metastatic spread in human malignant melanoma.

Malignant melanoma (MM), the most common cause of skin cancer deaths, metastasises to regional lymph nodes. In animal models of other cancers, lymphatic growth is associated with metastasis. To assess if lymphatic density (LD) was increased in human MM, and its association with metastasis, we measured LD inside and around archival MM samples (MM, n=21), and compared them with normal dermis (n=11), basal cell carcinoma (BCC, n=6) and Merkel cell carcinoma (MCC), a skin tumour thought to metastasise through a vascular route (MCC, n=6). Lymphatic capillary density (mm(-2)), as determined by immunohistochemical staining with the lymphatic specific marker LYVE-1, was significantly increased around MM (10.0+/-2.5 mm(-2)) compared with normal dermis (2.4+/-0.9 mm(-2)), BCC (3.0+/-0.9 mm(-2)) and MCC (2.4+/-1.4 mm(-2)) (P<0.0001). There was a small decrease in LD inside MM (1.1+/-0.7 mm(-2)) compared with normal dermis, but a highly significant decrease in BCC (0.14+/-0.13) and MCC (0.12+/-2.4) (P<0.01 Kruskal-Wallis). Astonishingly, LD discriminated between melanomas that subsequently metastasised (12.8+/-1.6 mm(-2)) and those that did not (5.4+/-1.1 mm(-2), P<0.01, Mann-Whitney). Lymphatic invasion by tumour cells was seen mainly in MM that metastasised (70% compared with 12% not metastasising, P<0.05 Fisher's Exact test). The results show that LD was increased around MMs, and that LD and tumour cell invasion of lymphatics may help to predict metastasis. To this end, a prognostic index was calculated using LD, lymphatic invasion and thickness that clearly discriminated metastatic from nonmetastatic tumours.

The detection of tyrosinase mRNA in peripheral blood samples is unlikely to aid in the management of patients with localised malignant melanoma.

A number of authors have reported the detection of tyrosinase mRNA in the peripheral blood of patients with malignant melanoma using the reverse transcription polymerase chain reaction (RT-PCR). The precise value of this assay as a prognostic tool, however, remains in doubt. This is particularly so with relation to localised disease, where relatively little data has been accumulated. In this study we analysed the peripheral blood of 50 consecutive patients with primary malignant melanoma referred to a plastic surgical centre with the facility of a pigmented lesion clinic. Samples were analysed from an additional 35 patients with advanced melanoma disease and 35 patients with benign pigmented cutaneous lesions. We were able to identify tyrosinase transcripts in the peripheral blood of only two of 50 patients with localised disease. Of those with more advanced disease, a positive finding was found in three with regional disease and four patients with metastatic spread. Stage of disease was found to correlate significantly with PCR status. No correlation was identified with other prognostic markers or with outcome over a three-year period. This data would support the conclusion that the detection of tyrosinase mRNA in peripheral blood is likely to be of little value as an aid in the management of patients with early malignant melanoma.

Nodal metastatic melanoma in the neck of a 4-year-old girl after diagnosis of Spitz nevus of the cheek.

A 4-year-old girl was referred to the plastic surgery unit with metastatic malignant melanoma diagnosed in a cervical lymph node. She had previously undergone excision of a Spitz nevus of the cheek at age 18 months. The management of this patient is discussed along with a review of the literature relating to Spitz nevi and malignant melanoma in childhood.

An unusual cause for a colonic stricture: a case of Mycobacterium xenopi mimicking malignancy.

Colonic strictures are very common and are a frequent finding on double contrast barium examination; they very often reflect the presence of malignancy, diverticular disease, ischaemia, inflammatory bowel disease, and rarely mycobacterial disease. A case of mycobacterial disease mimicking malignancy is presented; this was due to a rare mycobacterial subtype and there was complete resolution of symptoms with antimycobacterial therapy.

Detection of melanoma seeding during surgical procedures--an RT-PCR based model.

AIM: It has long been suggested that malignant cells may be shed into the blood stream during any given surgical procedure for cancer. A number of studies have now reported the detection of occult melanoma cells in peripheral blood using a reverse transcriptase polymerase chain reaction (RT-PCR) based assay. The principal aim of these studies has been to determine a prognostic value for the test and not to evaluate the influence of intervention upon results. METHODS: In this pilot study we aimed to determine whether the assay could be used as a model to detect cells that are seeded during surgery. Peripheral blood samples were obtained pre- and post-operatively on twenty patients undergoing surgery for malignant melanoma - ten with primary disease and ten undergoing regional lymphadenectomy. A further ten patients undergoing surgery for non-melanoma conditions provided controls. RESULTS: Using RT-PCR, it was possible to identify tyrosinase transcripts in the peripheral blood of one of ten patients undergoing excision of local disease and four of ten undergoing surgery for regional metastatic disease. CONCLUSION: It was concluded that this technique does enable detection of a greater percentage of RT-PCR findings post-operatively. This in turn may provide a means for optimizing or comparing surgical techniques and provides a potential guide in the use of adjuvant therapies.

A 6 year prospective analysis of the diagnosis of malignant melanoma in a pigmented-lesion clinic: even the experts miss malignant melanomas, but not often.

We investigated whether the pigmented-lesion clinic (PLC) run by the Department of Plastic and Reconstructive Surgery at Frenchay Hospital was effective in making and excluding the diagnosis of malignant melanoma, by looking at the pattern of referrals over time, the number of melanomas excised and melanomas in which the diagnosis was delayed or missed. We also investigated whether the PLC was having an effect on the thicknesses of melanomas excised. All 9968 patients attending the PLC between 1 January 1993 and 31 December 1998 were included in the study and 586 malignant melanomas were diagnosed; 24.7% of excisions led to the diagnosis of malignant melanoma. Seven invasive melanomas and two lentigo malignas were missed. There was one histological false negative. The PLC has a sensitivity of 98.5% and specificity of 89.2% for the diagnosis of melanoma; the negative predictive value is 99.9%. The PLC is effective in rapidly making or excluding the diagnosis of malignant melanoma, but has had no effect on the average thickness of melanomas excised over the 6 year study period.

Is routine histological reporting of doughnuts justified after anterior resection for colorectal cancer?

OBJECTIVE: 'Doughnuts' of colonic tissue which remain on a circular stapler after firing are routinely examined histologically. However, Royal College of Pathologists' guidelines state that this is not necessary. The aim of this study was to examine current practice among pathologists in one region in the UK and to determine the incidence of clinically significant pathology within colonic doughnuts. METHODS: Current practice in all pathology Departments within the South-west Region was examined and 100 doughnuts from anterior resection specimens were reviewed for the presence of abnormal pathology. RESULTS: Practice varied between hospitals with only 15% following guidelines for examination of doughnuts and 38% following guidelines for reporting of resection margins. Review of pathology specimens demonstrated no incidence of colonic adenocarcinoma in a doughnut. Benign pathology was present in 9% and dysplasia in 3% but in no case was patient management altered as a result of the pathology report. CONCLUSION: Application of recommended guidelines is inconsistent. We have demonstrated a low incidence of clinically significant pathology in doughnuts and more economical guidelines could therefore be safely applied without detriment to patient care.