The association between iron deficiency and outcomes: a secondary analysis of the intravenous iron therapy to treat iron deficiency anaemia in patients undergoing major abdominal surgery (PREVENTT) trial

In the intravenous iron therapy to treat iron deficiency anaemia in patients undergoing major abdominal surgery (PREVENTT) trial, the use of intravenous iron did not reduce the need for blood transfusion or reduce patient complications or length of hospital stay. As part of the trial protocol, serum was collected at randomisation and on the day of surgery. These samples were analysed in a central laboratory for markers of iron deficiency. We performed a secondary analysis to explore the potential interactions between pre-operative markers of iron deficiency and intervention status on the trial outcome measures. Absolute iron deficiency was defined as ferritin <30 μg.l^-1 ; functional iron deficiency as ferritin 30-100 μg.l^-1 or transferrin saturation < 20%; and the remainder as non-iron deficient. Interactions were estimated using generalised linear models that included different subgroup indicators of baseline iron status. Co-primary endpoints were blood transfusion or death and number of blood transfusions, from randomisation to 30 days postoperatively. Secondary endpoints included peri-operative change in haemoglobin, postoperative complications and length of hospital stay. Most patients had iron deficiency (369/452 [82%]) at randomisation; one-third had absolute iron deficiency (144/452 [32%]) and half had functional iron deficiency (225/452 [50%]). The change in pre-operative haemoglobin with intravenous iron compared with placebo was greatest in patients with absolute iron deficiency, mean difference 8.9 g.l^-1 , 95%CI 5.3-12.5; moderate in functional iron deficiency, mean difference 2.8 g.l^-1 , 95%CI -0.1 to 5.7; and with little change seen in those patients who were non-iron deficient. Subgroup analyses did not suggest that intravenous iron compared with placebo reduced the likelihood of death or blood transfusion at 30 days differentially across subgroups according to baseline ferritin (p = 0.33 for interaction), transferrin saturation (p = 0.13) or in combination (p = 0.45), or for the number of blood transfusions (p = 0.06, 0.29, and 0.39, respectively). There was no beneficial effect of the use of intravenous iron compared with placebo, regardless of the metrics to diagnose iron deficiency, on postoperative complications or length of hospital stay.

The emerging specialty of perioperative medicine: a UK survey of the attitudes and behaviours of anaesthetists

Background

In 2014, the Royal College of Anaesthetists (RCoA) launched the Perioperative Medicine Programme to facilitate the delivery of best preoperative, intraoperative and postoperative care through implementation of evidence-based medicine to reduce variation and improve postoperative outcomes. However, variation exists in the establishment of perioperative medicine services in the UK. This survey explored attitudes and behaviours of anaesthetists towards perioperative medicine, described current anaesthetic-led perioperative medicine services across the UK and explored barriers to anaesthetic involvement in perioperative medicine.

Methods

Survey content based on the RCoA vision document was refined and validated using an expert panel. An anonymous electronic survey was then sent by email to the members of the RCoA.

Results

Seven hundred fifty-eight UK anaesthetists (4.5% of the RCoA mailing list) responded to the survey. Of these, 64% considered themselves a perioperative doctor, with 65% having changed local services in response to the RCoA vision. Barriers to developing perioperative medicine included insufficient time (75%) and inadequate training (51%). Three quarters of respondents advocate anaesthetists leading the development of perioperative medicine.

Conclusions

Despite evidence of emerging services, this survey describes barriers to ongoing development of perioperative medicine. Facilitators may include increased clinical exposure, targeted education and training and collaborative working with other specialties.

Perioperative Medicine for Older People

Global demographic changes have resulted in an older, frailer surgical population with significant multimorbidity causing higher frequency of adverse postoperative outcomes. The need for restructuring of perioperative care pathways to address this issue has been recognised. Comprehensive geriatric assessment (CGA) and optimisation are emerging as innovative perioperative pathways. This paper describes one centre’s approach in applying CGA in the surgical setting and presents the evidence in support of this. Similar models are being established in Singapore in hip fracture, colorectal and vascular populations. The challenges in the widespread adoption of such models of care are similar across settings. The global nature of translation is also discussed in this paper. Key words: Comprehensive geriatric assessment, Geriatrician-led multidisciplinary team, Optimisation

Perioperative Medicine for Older People

Global demographic changes have resulted in an older, frailer surgical population with significant multimorbidity causing higher frequency of adverse postoperative outcomes. The need for restructuring of perioperative care pathways to address this issue has been recognised. Comprehensive geriatric assessment (CGA) and optimisation are emerging as innovative perioperative pathways. This paper describes one centre's approach in applying CGA in the surgical setting and presents the evidence in support of this. Similar models are being established in Singapore in hip fracture, colorectal and vascular populations. The challenges in the widespread adoption of such models of care are similar across settings. The global nature of translation is also discussed in this paper.

Perioperative comprehensive geriatric assessment: what do we need to know?

As a consequence of an ageing population greater numbers of elderly patients are presenting for both elective and emergency surgery. These older patients typically present with an increased burden of age-related problems and multimorbidity, which is associated with an increased risk of adverse postoperative outcomes. Traditional preoperative assessment models are adept at discerning patients' suitability for anaesthesia and surgery, but there is minimal focus on improving postoperative outcomes.

Comprehensive geriatric assessment is a multidisciplinary approach used both to assess existing ‘known’ pathology and to screen for previously undiagnosed issues across medical, functional, social and/or psychological domains. This diagnostic phase then leads to the development and implementation of an individualized ‘optimization’ strategy across these domains. There is emerging evidence that comprehensive geriatric assessment and optimization in the surgical setting leads to improved outcomes, and it is reasonable to conclude that it would benefit the patient's long-term health.

Successful Ageing in Singapore

Singapore has experienced rapid development in the past 50 years. This has presented unique challenges with regard to land space and a rapidly ageing population. The role of extrinsic factors in successful ageing is well documented, and places a degree of responsibility on the state and healthcare systems. Singapore has taken many proactive measures to meet this responsibility by implementing policy changes across multiple domains including housing, transport, education and research. One hospital in the north east of Singapore has undertaken a frailty screening program that aims to identify, prevent and reverse frailty at an early stage. This paper provides a review of these national and regional measures.

A Foundation Programme educational placement in peri-operative medicine for older people: mixed methods evaluation

We established an innovative Foundation placement in peri-operative medicine for older patients in response to the need for training in 'whole patient' medicine and the challenge of fewer Foundation doctors in acute surgical roles. The placement and underpinning curriculum were co-designed with junior doctors and other clinical stakeholders. This resulted in a modular design offering acute and community experience and dedicated quality improvement project time. To evaluate the placement we used a mixed methods study based on Kirkpatrick's model of workplace learning. Level 1 (trainee reaction) was evaluated using Job Evaluation Study Tool questionnaires and nominal group technique. Levels 2 and 3 (trainee learning/behaviour) were assessed using a Likert-style survey mapped to curriculum objectives, e-portfolio completion, nominal group technique and documentation of completed quality improvement projects and oral/poster presentations. Sixty-eight foundation trainees underwent the new placement. A similar-sized 'control' sample (n = 57) of surgical Foundation trainees within the same Trust was recruited. The trainees in the peri-operative placement attained both generic Foundation and specific peri-operative curriculum competencies, and gave higher job satisfaction scores than trainees in standard surgical placements. The top three ranked advantages from the nominal group sessions were senior support, clinical variety and project opportunities. Universal project completion resulted in high rates of poster and platform presentations, and in sustained service changes at hospital level.

High numbers of Staphylococcus aureus at three bathing beaches in South Florida

While the value of Staphylococcus aureus as an indicator for non-enteric diseases is unclear, understanding its prevalence in recreational beaches would prove useful, given its pathogenic potential. Staphylococcus aureus levels were evaluated in sand and seawater at three beaches during one year. To elucidate possible S. aureus sources or colonization trends, distribution in sand was analyzed at Hollywood Beach. Staphylococcus aureus levels fluctuated throughout the study with highest average densities detected in dry sand (3.46 × 10⁵ CFU/g, Hobie Beach), particularly at beaches with high human density. Patchy distribution marked hotspots of human use and/or possible bacterial re-growth. Data from a brief epidemiological survey indicated a very slight association between beach usage and skin conditions; suggesting high S. aureus levels in sand may not necessarily constitute major health risks. Because the possibility of disease transmission exists, particularly to children and immuno-compromised beach-goers, periodic surveying of highly frequented beaches seems warranted.

Survival trends of Staphylococcus aureus, Pseudomonas aeruginosa, and Clostridium perfringens in a sandy South Florida beach

The search for alternative indicators of disease-risk from non-enteric pathogens at the beach revealed high densities of targeted bacteria. To explain the high numbers of potential non-enteric pathogens, Staphylococcus aureus and Pseudomonas aeruginosa, in beach sand, we investigated factors affecting their survival and distribution, as well as those of a potential fecal indicator, Clostridium perfringens. Results indicated greater S. aureus and P. aeruginosa survival and proliferation in sterile beach sand, than seawater, with diminished numbers upon exposure to natural micro-predators. C. perfringens remained relatively consistent with initial numbers. Intermediate sand particles (850 μm-2 mm) constituted the major micro-niche; creating implications for beach classification programs. Colonization of sterile sand boxes at the beach by S. aureus and P. aeruginosa confirmed the filtering action (>100×) of beach sand. The use of these potential pathogens in periodic sanitary evaluation of beach sand quality is indicated, regardless of the factors influencing their abundance.

Parvamoeba rugata n. g., n. sp., (Gymnamoebia, Thecamoebidae): An exceptionally small marine naked amoeba

A small naked marine amoeba isolated from the Cycle Sea area on the west coast of Scotland is described as Parvamoeba rugata n. g., n. sp. It is remarkable in that it is the smallest example of a marine naked amoeba yet to be described and may represent a size class of heterotrophic amoebae worthy of future ecological consideration. It has characters justifying its inclusion in the family Thecamoebidae, notably prominent surface wrinkling obvious with the light microscope, the possession of a Thecamoeba-like glycocalyx, and a nucleus with an electron dense layer similar to the lamella of the Thecamoebidae. However, although its general morphology is compatible with membership in this family, P. rugata has additional features not found in any of the described genera of thecate amoebae. Characters of note include its extremely small size (mean length only 3.9 μm), random surface folds, a raised rather than flattened cell mass and fine subpseudopodia extending from the edge of the hyaloplasm which are not normally associated with Thecamoeba-like amoebae. These features warrant its inclusion in a new genus to be accommodated within the family Thecamoebidae.

Complementary and alternative medicine use among women receiving chemotherapy for ovarian cancer in 2 patient populations

OBJECTIVE

The authors evaluated attitudes toward complementary and alternative medicine (CAM) use in 2 populations of women receiving chemotherapy for epithelial ovarian cancer (EOC).

METHODS

Women with EOC currently being treated with chemotherapy at 2 tertiary cancer centers, in Canada and the United Kingdom, completed a self-administered questionnaire on attitudes and perceptions of CAM and types of CAM used within the previous month.

RESULTS

One hundred ninety-two patients (94 from Canada, 98 from United Kingdom) completed the questionnaire. Overall, 85 women (44%) were identified as CAM users. Complementary and alternative medicine use was more common among Canadian women (52%) compared with women from the United Kingdom (37%), P = 0.02. Participants used 71 different types of CAM, the majority (61%) taking multiple CAM. The frequency of CAM use was the same in primary compared with recurrent disease. Eighty-nine percent of CAM users considered it important for their oncologist to be aware of CAM use. Canadian women, however, were less likely to inform their physician (Canada: 50%; United Kingdom: 81%), P = 0.02. Motivations for CAM use were the same in both populations including assist healing (60%), boost the immune system (57%), improve quality of life (48%), and relieve symptoms (45%). Thirteen percent thought CAM could cure cancer, whereas 17% thought it would prevent recurrence.

CONCLUSIONS

Complementary and alternative medicine use is common in women receiving chemotherapy for EOC. Increasingly, interactions between CAM and prescribed medication are being identified. Oncologists should be aware and actively inquire about CAM use. Although patterns of CAM use differed, the motivation for starting CAM was similar, highlighting the need to address supportive care in all patients.

Use of complementary medicine (CAM) among women receiving chemotherapy for ovarian cancer: A comparison of attitudes between two patient populations

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Background: CAM use in cancer patients (pts) is common. The aim of this study was to compare patterns of CAM use and attitudes to CAM among ovarian cancer (EOC) pts in Canada and Scotland. Methods: Patients receiving chemotherapy for EOC in Princess Margaret Hospital (PMH), Toronto and the Edinburgh Cancer Centre (ECC), Scotland, completed a survey on CAM taken within the previous month as well as a questionnaire assessing patient attitudes and perceptions of CAM. A comparison between the 2 patient populations and between CAM users and non-users was made. Results: 194 pts (100 ECC: 94 PMH) were enrolled on study. The use of CAM in PMH was significantly higher than in ECC (52% vs. 36%, p=0.02). Whilst both populations thought it important for their oncologist to be aware of CAM usage (86% PMH: 93% ECC), pts from PMH were less likely to inform their compared to pts from ECC (50% vs 81%, p=0.02). Patterns of CAM use differed between the 2 populations: Multivitamins were the most common CAM in both populations (31% PMH:13% ECC). They were not considered CAM for the purpose of analysis. Most commonly used CAM in PMH were Soy products (12%), vitamin C (10%) and Green Tea (9%); in ECC pts used Omega 3 and fish oil (9%), Evening Primrose (7%) and vitamin C (6%). Although the majority of CAM users in both populations found CAM to be helpful (57% PMH: 61% ECC) only a minority thought they would cure their cancer (18% PMH: 6% ECC), prevent its spread (31% PMH: 14% ECC) or prevent a recurrence (20% PMH: 11% ECC). Users more often felt CAM relieved symptoms (45% PMH: 42% ECC), boosted the immune system (55% PMH: 56% ECC) or improved their quality of life (43% PMH: 53% ECC). ECC CAM users were more likely than PMH users to concede that CAMs have side effects (39% vs 29%) or could impact the efficacy of conventional treatment (17% vs 6%). CAM users were more likely than non-users to agree with positive statements and to disagree with negative statements about CAM. Conclusions: CAM use is common among pts receiving chemotherapy for EOC. CAM use was more prevalent among North American pts than Scottish pts. Attitudes and patterns of CAM usage differ and are culturally sensitive. Oncologists need to be aware of this when initiating discussion about CAM with their patients during cancer treatment.

No significant financial relationships to disclose.

Survival potential of Escherichia coli and Enterococci in subtropical beach sand: implications for water quality managers

Fecal bacteria have traditionally been used as indicator organisms to monitor the quality of recreational waters. Recent work has questioned the robustness of traditional indicators, particularly at seawater bathing beaches. For example, a study of Florida beaches found unexpectedly high abundances of Escherichia coli, fecal coliforms, and enterococci in beach sand. The aim of the present study was to explain these abundances by assessing the survival of E. coli and enterococci in beach sand relative to seawater. We used a combination of quantitative laboratory mesocosm experiments and field observations. Results suggested that E. coli and enterococci exhibited increased survivability and growth in sand relative to seawater. Because fecal bacteria are capable of replicating in sand, at least under controlled laboratory conditions, the results suggest that sand may be an important reservoir of metabolically active fecal organisms. Experiments with "natural" mesocosms (i.e., unsterilized sand or water rich in micropredators and native bacteria) failed to show the same increases in fecal indicators as was found in sterile sand. It is postulated that this was due to predation and competition with indigenous bacteria in these "natural" systems. Nonetheless, high populations of indicators were maintained and recovered from sand over the duration of the experiment as opposed to the die-off noted in water. Indicator bacteria may wash out of sand into shoreline waters during weather and tidal events, thereby decreasing the effectiveness of these indicators as predictors of health risk and complicating the interpretations for water quality managers.

Prevalence of Acanthamoeba and other naked amoebae in South Florida domestic water

The purpose was to identify the prevalence of naked amoebae in tap water in south Florida to ascertain the risk of amoebal infections of the cornea in contact lens wearers. Over the course of a 2-year period, water samples were collected from sites throughout Broward, Palm Beach, and Dade counties, Florida. The presence of amoebae in samples was based on an enrichment cultivation method appropriate for Acanthamoeba. Amoebae were identified using diagnostic features discernable by light microscopy. A total of 283 water samples were processed and amoebae were noted in 80 of these. Acanthamoeba were found on 8 occasions (2.8%). The genera Hartmannella and Vahlkampfia, rarely involved in keratitis cases, were found in 3.5% and 2.8% of samples, respectively. A total of 19 different naked amoebae were recorded and amoebae (regardless of genus) were present in 19.4% of all samples. Previous surveys in England and Korea have shown that acanthamoebae are found in 15 to 30% of tap water samples in the home and have been associated with corneal infection in contact lens wearers. The incidence of acanthamoebae infection in the USA (2.8%) has been found to be lower than that in the UK and it has been postulated that this is related to the lack of a storage water tank in the roof loft space. However, the level of treatment of municipal water is clearly not effective at killing amoebal cysts (or trophozoites) as evidenced by the high occurrence of amoebae (19.4%) in this study.

Prevalence and distribution of fecal indicator organisms in South Florida beach sand and preliminary assessment of health effects associated with beach sand exposure

Fecal indicator levels in nearshore waters of South Florida are routinely monitored to assess microbial contamination at recreational beaches. However, samples of sand from the surf zone and upper beach are not monitored which is surprising since sand may accumulate and harbor fecal-derived organisms. This study examined the prevalence of fecal indicator organisms in tidally-affected beach sand and in upper beach sand and compared these counts to levels in the water. Since indicator organisms were statistically elevated in sand relative to water, the study also considered the potential health risks associated with beach use and exposure to sand. Fecal coliforms, Escherichia coli, enterococci, somatic coliphages, and F(+)-specific coliphages were enumerated from sand and water at three South Florida beaches (Ft. Lauderdale Beach, Hollywood Beach, and Hobie Beach) over a 2-year period. Bacteria were consistently more concentrated in 100g samples of beach sand (2-23 fold in wet sand and 30-460 fold in dry sand) compared to 100ml samples of water. Somatic coliphages were commonly recovered from both sand and water while F(+)-specific coliphages were less commonly detected. Seeding experiments revealed that a single specimen of gull feces significantly influenced enterococci levels in some 3.1m(2) of beach sand. Examination of beach sand on a micro-spatial scale demonstrated that the variation in enterococci density over short distances was considerable. Results of multiple linear regression analysis showed that the physical and chemical parameters monitored in this study could only minimally account for the variation observed in indicator densities. A pilot epidemiological study was conducted to examine whether the length of exposure to beach water and sand could be correlated with health risk. Logistic regression analysis results provided preliminary evidence that time spent in the wet sand and time spent in the water were associated with a dose-dependent increase in gastrointestinal illness.

Prevalence of yeasts in beach sand at three bathing beaches in South Florida

The abundance and types of yeasts in the wet and dry sand of three recreational beaches in South Florida were determined. Samples were collected on 17 occasions between August 2001 and July 2002. After analyzing 102 sand samples, a total of 21 yeast species were identified by molecular methods. These isolates comprised four Basidiomycetes and 17 Ascomycetes and included eight species that had previously been reported from humans. The most frequently encountered yeasts were Candida tropicalis and Rhodotorula mucilaginosa. A greater diversity of species (16 species) was found in the dry sand above the high tide mark compared with the wet sand in the intertidal zone (11 species). Densities were also highest in the dry sand relative to wet sand (20-fold higher at Hobie beach, 6-fold higher at Fort Lauderdale Beach and 1.3-fold higher at Hollywood beach). There were no clear temporal patterns in the data and overall densities were greatest at the busiest bathing beach (Hobie Beach) where total yeasts averaged 37,720 cfu 100g(-1) dry sand and 1852 cfu 100 g(-1) in the wet sand. This concentration of yeast was significantly higher than populations at the less populated beaches. Fort Lauderdale beach had a mean count of 4130 cfu 100 g(-1) dry sand and 705 cfu 100g(-1) in the wet sand while the least populated beach, Hollywood Beach averaged 1945 cfu 100g(-1) dry sand and 1483 cfu 100g(-1) wet sand. While definitive statements cannot be made, high levels of yeasts may have a deleterious bearing on human health and the presence of such a diverse aggregation of species suggests that yeasts could have a role as indicators of beach health.

Variable Responses of Acanthamoeba Strains to Three Multipurpose Lens Cleaning Solutions

PURPOSE

A novel method has been developed to compare Acanthamoeba strain differences by testing their susceptibility to multipurpose contact lens cleaning solutions (MPS).

METHODS

This method uses surface-attached amoebae that mimic cells attached to a contact lens. In brief, acanthamoebae were grown on non-nutrient agar plates with Escherichia coli prey. Blocks of agar with cysts or trophozoites (approximately 50 cells) were cut out and transferred to MPS [ReNu MultiPlus; (Bausch & Lomb, Rochester, NY), Complete (Allergan, Irvine, CA), and Opti-Free Express (Alcon, Ft. Worth, TX)] for up to 24 h treatment. After neutralizing in Dey Engley broth (Difco), blocks were washed in amoeba saline and reinoculated onto fresh prey bacteria. Positive growth was indicative of survival.

RESULTS

Testing showed that the efficacy of the three MPS was different. Opti-Free was the most effective against cysts, followed by ReNu while Complete was relatively ineffective. Not surprisingly, trophozoites were more susceptible than cysts.

CONCLUSIONS

Findings for individual MPS complement previous work with other methods. This study has also identified that environmental strains vary in their sensitivity to disinfecting solutions. Overall, Acanthamoeba genotypes T3, T5, and T11 from the environment were more resistant than the T4 isolates from the cornea and beach. This resilience supports previous work on temperature tolerance, in which T3 and T5, and T11 acanthamoebae grew in temperatures up to 41 degrees C. Investigators should therefore consider the strain genotype and its source before embarking on MPS sensitivity testing.

Molecular and physiological evaluation of subtropical environmental isolates of Acanthamoeba spp., causal agent of Acanthamoeba keratitis

Previous molecular examination of Acanthamoeba spp. has resulted in the determination of distinct genotypes in this genus (designated T1-T12, T14). Genotype T4 has been responsible for the majority of cases of Acanthamoeba keratitis. Here we examine the relative abundance of environmental T4 isolates on beaches and ask whether they have temperature and salinity tolerances that could enhance pathogenicity. Twenty-four Acanthamoeba strains were isolated from beach sand (n = 20), soil (n = 3), and tap water (n = 1) in south Florida. Phylogenetic analysis identified 19 of 24 isolates as T4, the Acanthamoeba keratitis-associated genotype. The remaining isolates were genotype T5 (4) and T11 (1). Nearly all beach isolates were genotype T4, whereas the tap water and soil isolates were mostly T5. All amoebae grew at 0, 1.0, and 2.0% salt and 19 of 20 beach isolates also grew at 3.2%. No soil or tap-water acanthamoebae reproduced at 3.2%. All isolates grew at 37 degrees C and two (T5) at 42 degrees C. Little correlation existed between beach location, salt-tolerance, and genetic relatedness. Overall, the large majority of environmental isolates obtained were genotype T4, suggesting it may be the most common genotype in this environment and could be a potential source of Acanthamoeba keratitis infections.

The application of peptide nucleic acid probes for rapid detection and enumeration of eubacteria, Staphylococcus aureus and Pseudomonas aeruginosa in recreational beaches of S. Florida

A novel chemiluminescent in situ hybridization technique using peptide nucleic acids (PNA) was adapted for the detection of bacteria in beach sand and recreational waters in South Florida. The simultaneous detection and enumeration of eubacteria and the novel indicators, Staphylococcus aureus and Pseudomonas aeruginosa, was achieved within 6-8 h of processing. Following 5 h of incubation on TSA, soybean peroxidase-labeled peptide nucleic acid probes (Boston Probes, Boston, MA) targeting species-specific 16S rRNA sequences of P. aeruginosa and S. aureus were used to hybridize microcolonies of the target species in-situ. In addition, a universal probe for 16S rRNA sequences was used to target the eubacteria. Probes were detected after a light generating reaction with a chemiluminescent substrate and their presence recorded on Polaroid film. The probes showed limited cross-reactivity with mixed indigenous bacteria extracted from seawater and sand by shaking with phosphate-buffered saline (PBS). Specificity and cross-reactivity was tested on the reference bacterial genera Pseudomonas, Staphylococcus, Vibrio, Shigella, Salmonella, Acinetobacter, Enterobacter, Escherichia and Citrobacter. These tests confirmed that the probes were specific for the microorganisms of interest and were unaffected by high salt levels. The results of the PNA chemiluminescent in situ hybridization were compared with traditional plate count methods (PCM) for total 'freshwater' eubacteria, S. aureus and P. aeruginosa. Counts of eubacteria and S. aureus were comparable with numbers obtained from traditional plate counts but levels of P. aeruginosa were higher with PNA than with PCM. It is possible that PNA is more sensitive than PCM because it can detect microcolonies on the agar surface that never fully develop with the plate count method. We conclude that the in situ hybridization technique used here represents an important potential tool for the rapid monitoring of novel indicator organisms in beaches and recreational waters.

Identification and phylogenetic analysis of morphologically similar naked amoebae using small subunit ribosomal RNA

Fan-shaped, naked amoebae are commonly encountered in samples from freshwater and marine habitats suggesting that they are an important component of the microbial food web. However, there are considerable problems in both detecting these amoebae and identifying them, given their morphological similarity. In this study we used restriction analysis and partial sequence analysis of the small-subunit 18S ribosomal RNA gene to examine the phylogenetic relationships between nine "fan-shaped" Vannella and Platyamoeba species. The molecular phylogeny showed that the marine Vannella and Platyamoeba isolates are closely related, whereas the freshwater isolates are disparate. Thus, the current reliance on the fine structure of the cell coat (glycocalyx) used to separate these genera is not justified. The study also highlights sequence elements that might be targeted by fluorescent probes for the direct detection of these amoebae in field samples. The molecular data were also used to aid the identification of three unknown fan-shaped isolates. All three unknowns resembled Vannella or Platyamoeba. However, one of the strains (a small < 10 microm, benthic, fan-shaped amoeba) probably represents a new genus.

Platyamoeba pseudovannellida n. sp., a naked amoeba with wide salt tolerance isolated from the Salton Sea, California

A new species of naked amoeba, Platyamoeba pseudovannellida n.sp., is described on the basis of light microscopic and fine structural features. The amoeba was isolated from the Salton Sea, California, from water at a salinity of ca. 44%. Locomotive amoebae occasionally had a spatulate outline and floating cells had radiating pseudopodia, sometimes with pointed tips. Both these features are reminiscent of the genus Vannella. However, the surface coat (glycocalyx) as revealed by TEM indicates that this is a species of Platyamoeba. Although salinity was not used as a diagnostic feature, this species was found to have remarkable tolerance to fluctuating salinity levels, even when changes were rapid. Amoebae survived over the range 0 per thousand to 150 per thousand salt and grew within the range 0 per thousand to 138 per thousand salt. The generation time of cells averaged 29 h and was not markedly affected by salt concentration. This is longer than expected for an amoeba of this size and suggests a high energetic cost of coping with salinity changes. The morphology of cells changed with increasing salinity: at 0 per thousand cells were flattened and active and at the other extreme (138 per thousand) amoebae were wrinkled and domed and cell movement was very slow. At the ultrastructural level, the cytoplasm of cells grown at high salinity (98 per thousand was considerably denser than that of cells reared at 0 per thousand.

High numbers of naked amoebae in the planktonic waters of a mangrove stand in southern Florida, USA

This is the first study to examine the abundance of naked amoebae in the water column of a mangrove stand. A total of 37 different morphotypes was noted and at least 13 of these are probably new species. Over a one-year sampling interval, amoebae averaged 35,400 cells liter(-1) (range 2,000-104,000) by an indirect enrichment cultivation method. Densities in the upper end of this range are the highest ever reported for any planktonic habitat. Variation between samples was related to the quantity of suspended aggregates (flocs) in the water column emphasizing that amoebae are usually floc-associated. The study also showed that it is essential to disrupt floc material prior to withdrawing sample aliquots for the indirect counting method since several amoebae can occupy the interstices of aggregates. There is concern that indirect enumeration methods that require organisms to be cultured in the laboratory seriously underestimate the true count. A direct counting method using acridine orange staining and epifluorescence microscopy was attempted to assess the possible magnitude of the error associated with indirect counting. While this direct method had limitations, notably the difficulty of unambiguously differentiating between small amoebae and nanoflagellates, the results suggested that the indirect method gave estimates that were close to the true count (within a factor of two). Mangrove waters are rich in heterotrophic protozoa (approximately 3 x 10 liter(-1)) and while the heterotrophic flagellates are by far the dominant group, naked amoebae outnumber ciliates some 20-fold. The ecological consequences of high numbers of amoebae, particularly the common small forms less than 10 microm in length, need to be examined for these important coastal sites.

Primary and secondary structure of the small-subunit ribosomal RNA of the naked, marine amoeba Vannella anglica: phylogenetic implications

The primary and secondary structure of the small-subunit ribosomal RNA (ssrRNA) gene from the naked, marine amoeba, Vannella anglica (subclass Gymnamoebia), was determined. The ssrRNA is 1962 nucleotides in length, with a low G+C content of 37.1%. The ssrRNA is composed of several uncommon secondary structure features including helix E8-1, which may be a useful target for rRNA probes for the direct identification of isolates in mixed culture. Phylogenetic analysis of sequence data showed that V. anglica branched prior to the rapid diversification of the eukaryotes. It did not associate with the other naked, lobose amoebae represented by Acanthamoeba and Hartmannella, indicating that Vannella represents a separate amoeboid lineage and the subclass Gymnamoebia is polyphyletic.

Evolution of cell adhesion systems: evidence for Arg-Gly-Asp-mediated adhesion in the protozoan Neoparamoeba aestuarina

Developmental processes in multicellular organisms require structural elements, such as adhesion molecules, to stabilize cells at functional positions. In vertebrates, a series of extracellular matrix proteins, e.g. fibronectin and laminin, are involved in cell adhesion. These proteins contain Arg-Gly-Asp [RGD] at their binding sites. Here we show that at concentrations above 2 mM the peptide GRGDSPK, comprising the tripeptide RGD (Arg-Gly-Asp), prevents the adhesiveness of cells of the marine amoeba Neoparamoeba aestuarina. In addition, elevated levels of GRGDSPK cause cells to alter their shapes from those with digitiform subpseudopodia to rounded cells with small lobed pseudopodia. These cells detach from the substratum. These results are specific for the RGD sequence, because incubation in GRGESPK solution at the same concentrations had no effect on cell attachment or structure. From these data we suggest that the structural adhesion molecules identified in vertebrates show amino acid homologies with those found in unicellular protozoa.

Computerized quantitative dynamic analysis of facial motion in the paralyzed and synkinetic face

Diagnosis, treatment, prognosis, and the neurobiology of recovery of facial paralysis has been impeded by the inability to quantitate facial movement objectively. The purpose of this paper is to report our preliminary results in the study of the paralyzed face using a newly developed computerized quantitative dynamic analysis system. Five normal volunteer subjects, and 17 patients with facial paralysis or paresis, from a wide range of etiologies, were analyzed utilizing the computerized analysis system; eight of these patients had synkinesis. Raw data image-change intensity: duration curves, numeric and graphic displays of curve parameter descriptive statistics, and rank order correlation analyses showed high levels of correlation between the computerized facial motion analysis and the House-Brackmann facial nerve grading system and a clinical grading scale for synkinesis. These data suggest that it is possible to develop a computerized image-difference analysis system that approximates the human ability to access facial movement and, additionally, deliver an equal-interval continuous quantitative data scale dynamic over a spectrum of time during facial motion.

Parenteral peptide formulations: chemical and physical properties of native luteinizing hormone-releasing hormone (LHRH) and hydrophobic analogues in aqueous solution

The degradation of native LHRH in aqueous buffers of pH approximately 1-10 obeyed the rate equation, kobs = kH + alpha H+ + ko + kHO-(alpha HO-)x, where x at 60-100 degrees C was approximately 0.64 and temperature independent. Extrapolation to 25 degrees C using the Arrhenius equation and secondary rate constants showed that native LHRH is reasonably stable at pH 5.4, giving a shelf life (t90) of approximately 5 years. Regarding physical properties, hydrophobic LHRH analogues nafarelin and detirelix were found to be surface active as demonstrated by a decrease in apparent surface tension with increased peptide concentration. The CMC for detirelix at pH 7.4 was determined to be 5.3 x 10(-4) M (0.88 mg/ml), and that for nafarelin, greater than 2 mg/ml. At higher concentrations (approximately 4-8 mg/ml), nafarelin and detirelix formed nematic liquid crystals of undulose extinction (birefringence, less than 0.001). The thermodynamic stability of these peptide liquid crystals was probed by determining their melting points (Tcm) in the presence of propylene glycol, a solvent which proved to be efficacious at suppressing gelation and at destabilizing liquid crystals as measured by a reduction in Tcm.

Antitumour activity and pharmacokinetics of niosome encapsulated adriamycin in monolayer, spheroid and xenograft

Niosomes are multilamellar vesicles formed from nonionic surfactants of the alkyl or dialkyl polyglycerol ether class and cholesterol. Adriamycin has been trapped within vesicles prepared from a monoalkyl triglycerol ether and its activity compared with adriamycin solution in human lung tumour cells grown in monolayer and spheroid culture and in tumour xenografted nude mice. The activity of the encapsulated adriamycin in vitro is maintained with similar clonogenic survival curves following treatment of monolayers and identical growth delays following spheroid exposure. The pharmacokinetics of adriamycin are altered in vivo in human lung tumour-bearing nude mice, when it is administered in niosomal form. There is prolonged release of drug from the plasma compartment with significantly lower peak levels; lower peak cardiac adriamycin concentrations with a shorter tissue half-life and decreased cardiac AUC and a greater degree of hepatic metabolism to inactive 7-deoxyaglycones. The tumour peak drug level and AUC was similar irrespective of the mode of administration of adriamycin. The growth delay (i.e. the time taken for the tumour volume to double) was significantly longer for adriamycin (15 days) and niosomal adriamycin (11 days) than for control (5.8 days). It is possible that the therapeutic ratio of adriamycin could be enhanced by administration in niosomal form.

The distribution of doxorubicin in mice following administration in niosomes

Large multilamellar non-ionic surfactant vesicles (niosomes) with diameters of around 800-900 nm prepared from a C16 triglyceryl ether with and without cholesterol and containing doxorubicin (Adriamycin) were administered to S180 tumour-bearing NMRI mice by bolus injection. Although in-vitro drug release from cholesterol-containing niosomes is delayed, in-vivo there was little difference between the two preparations when plasma levels were compared. As previously observed, half-lives of the drug were prolonged compared with free solution profiles. Liver uptake was not significantly affected by niosome encapsulation of doxorubicin. There is minor accumulation of drug in the lung, perhaps because of aggregation of the vesicles and their physical entrapment. Tumour levels of drug were higher following administration of cholesterol-containing niosomes and this was reflected in the more effective reduction in tumour growth. Metabolism of doxorubicin is altered by niosomal administration, but more studies are required before the significance of the metabolic data can be assessed.