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Many issues in biological oceanography are regional or global in scope; however, there are not many data sets of extensive areal coverage for marine plankton. In microbial ecology, a fruitful approach to large-scale questions is comparative analysis wherein statistical data patterns are sought from different ecosystems, frequently assembled from unrelated studies. A more recent approach termed macroecology characterizes phenomena emerging from large numbers of biological units by emphasizing the shapes and boundaries of statistical distributions, because these reflect the constraints on variation. Here, I use a set of flow cytometric measurements to provide macroecological perspectives on North Atlantic phytoplankton communities. Distinct trends of abundance in picophytoplankton and both small and large nanophytoplankton underlaid two patterns. First, total abundance of the three groups was related to assemblage mean-cell size according to the 3/4 power law of allometric scaling in biology. Second, cytometric diversity (an ataxonomic measure of assemblage entropy) was maximal at intermediate levels of water column stratification. Here, intermediate disturbance shapes diversity through an equitable distribution of cells in size classes, from which arises a high overall biomass. By subsuming local fluctuations, macroecology reveals meaningful patterns of phytoplankton at large scales.

PURPOSE: The aim of this study was to compare the outcome of patients receiving hemorrhoidectomy using Harmonic Scalpel™, bipolar scissors, and the conventional scissors excision–ligation technique. METHODS: Eighty-six patients with irreducible prolapsing piles were randomly assigned to receive 1) Milligan-Morgan hemorrhoidectomy using scissors excision–ligation technique or 2) bipolar scissors hemorrhoidectomy and Harmonic Scalpel™ hemorrhoidectomy. Neither the patient nor the independent assessor were aware of the technique used at operation. Patients were followed up at 4 and 12 weeks after operation. The measured outcomes included 1) operation time; 2) blood loss; 3) postoperative hospital stay; 4) pain score; 5) pain expectation score; 6) date of first bowel movement; 7) number of pethidine injections; 8) number of dologesic tablets taken; 9) time off work or normal activity; 10) wound healing; 11) satisfaction score; and 12) postoperative complications, including anal stenosis and fecal or flatus incontinence. RESULTS: There was no difference among the three groups in the operation time, hospital stay, pain expectation score, day of first bowel movement, number of dologesic tablets taken, time off work or normal activity, wound healing, and satisfaction score. The complication rate also did not differ in the three groups. Both Harmonic Scalpel™ hemorrhoidectomy and bipolar scissors hemorrhoidectomy were superior to Milligan-Morgan hemorrhoidectomy in terms of reduced blood loss. Harmonic Scalpel™ hemorrhoidectomy had the best pain score when compared with bipolar scissors hemorrhoidectomy and Milligan-Morgan hemorrhoidectomy, and patients required significantly less pethidine injection after Harmonic Scalpel™ hemorrhoidectomy than after Milligan-Morgan hemorrhoidectomy. Although the time required to return to work or normal activity remained similar, patients after Harmonic Scalpel™ hemorrhoidectomy had the best satisfaction score among the three groups. CONCLUSION: The study shows that Harmonic Scalpel™ hemorrhoidectomy is as good as bipolar scissors hemorrhoidectomy in terms of reduced blood loss but is superior because it is associated with less postoperative pain and hence, better patient satisfaction. However, these observed benefits are small, and the time off work or normal activity remains similar.

The most dreaded complication of a colonoscopy is colonic perforation. Perforation of the small bowel following colonoscopy is extremely rare, especially if the procedure was performed without any therapeutic intervention. Herein we report a case of jejunal perforation following a routine surveillance colonoscopy. A literature review focusing on the proposed mechanism of perforation is included.

Purpose To report a case of presumed bilateral choroidal metastases from mucoepidermoid carcinoma of submandibular gland. Methods Case report. A 52-year-old lady with history of left submandibular gland mucoepidermoid carcinoma developed bilateral choroidal metastases unresponsive to chemotherapy. She presented with a 3-week history of left eye pain. Fundoscopy revealed bilateral yellowish choroidal lesions associated with inferior exudative retinal detachment. B-scan ultrasonography showed high internal reflectivity of both lesions. Fluorescein angiography revealed pinpoint foci of hyperfluorescence over the choroidal lesion with late leakage. The patient declined positron emission tomography scan, radiotherapy, and surgical intervention. She eventually succumbed 5 months after the initial presentation. Result Our case is the first case report on clinically presumed bilateral choroidal metastases from mucoepidermoid carcinoma of the submandibular gland. Conclusion There are few reported cases of ocular metastasis from salivary gland tumors, mostly adenoid cystic carcinoma. To the best of our knowledge, this is the first reported case of bilateral choroidal metastases from mucoepidermoid carcinoma of the submandibular gland.

Vitreous substitutes have been developed both as an intraoperative and as a postoperative tool for the surgical treatment of complicated vitreoretinal diseases. The tamponade effect of the vitreous substitutes depends on the arc of contact between the agent and the inner retinal surface, which mainly depends on 4 physical parameters, namely, specific gravity, buoyancy, interfacial tension, and viscosity. As reported by F. Barca et al., the choice of different intraocular tamponade agents depends on the location of retinal break(s), compliance of postoperative posture, type of vitreoretinal disease(s), and duration required for the tamponade. Due to the hydrophobic property of intraocular tamponade agent, a thin aqueous layer invariably exists between the tamponade agent and the retina. This thin aqueous layer is further exaggerated in highly myopic eyes with posterior staphyloma to become a pocket of fluid leading to a theoretical reduction of the tamponade effect. However, the debate remains open on whether it is still worthwhile to use silicone oil in these eyes as X. Valldeperas and J. Lorenzo-Carrero reported contradicting results. An increased improved anatomical success using silicone oil in highly myopic eyes in their study was probably due to the lower shear retinal stress of the compartmentalized fluid, scarcely influenced by ocular movements, allowing the macular hole to close and the retinal detachment to reattach. Based on this hypothesis, K. Isakova et al. reported a theoretical model that predicted the stability conditions of the interface between the aqueous and a vitreous substitute. They showed that the presence of a thin layer of aqueous between the retina and intraocular tamponade is responsible for significant reduction in the retinal shear stress. Their model also explains the instability of the interface leading to the formation of intraocular emulsion that remains the main drawback of the use of intraocular tamponade agents. Although the tolerance for vitreous substitutes remains generally good, the recent introduction of new mixed compounds, such as heavy silicone oil (HSO), has been associated with relatively high complication rates. In particular, emulsification and severe inflammatory reactions can lead to poor functional prognosis. According to L. Ambrosone et al., the spontaneous formation of water-silicone oil is a rare event and the very low concentration of surface-active agents cannot account for the systematic production of emulsions. The authors suggested that gravitational instability, originated at the interface by tangential disturbances, plays a more significant role in the formation of emulsions. Semifluorinated compounds and perfluorocarbon liquids (PFCLs), mainly used only as intraoperative tamponades, are more prone to induce inflammation and emulsification. As reported by M. S. Figueroa and D. R. Casas, PFCLs have also been used as postoperative short-term tamponade agent with development of up to 30% inflammation and retinal infiltration due to foreign-body reaction, sustained by macrophages that phagocytosed the PFCL droplets. Q. Yu et al. suggested that the physical properties of these tamponade agents, mainly the low viscosity and surface tension, reduce their stability and the superficial forces and could lead to significant clinical findings such as intraocular inflammation, raised intraocular pressure (IOP), and sticky oil formation. From a retrospective study conducted on 100 eyes, H. Schwarzer et al. concluded that HSO does not induce alarming complications in the majority of cases. However, they suggested that long-term tamponade with HSO will require more frequent follow-up because of its high incidence of IOP elevations or intraocular inflammation. In fact D. Odrobina and I. Laudanska-Olszewska reported, at 3 months after the surgery, the topographic evidences of persistence of small hyperreflective round shaped SO droplets above the optic nerve and in the cystoid retinal spaces. Despite good anatomical success rate with HSO, J. Prazeres et al. reported a 52% rate of emulsification and 40% rate of keratic precipitates in their series with a 16% incident of IOP elevation. Interestingly F. Morescalchi et al. also reported more disturbing complications of HeavySil, a combination of high purity 75% silicone oil 5000 cSt and 25% perfluoroalkyloxyoctane, including early optic disc swelling, retinal edema, and intraretinal inflammation with diffuse narrowing of arteries and veins. The challenges of tamponade research remain the provision of a wider arc of tamponade and long-term intraocular permanence with inertness of the compound while at the same time providing uniform transport of nutrients to intraocular tissue. Despite years of effort, we still remain far from providing good solutions for these “solutions.” S. Donati et al. reported that a promising alternative to the present compounds could be the smart hydrophilic polymers. They are capable of swelling by absorbing its own weight in water, with further possibilities of a thermosetting and with interactive properties with the environment (glucose, glutathione), pH, and light. These properties allow the molecules to be modulated inducing the gelification, better drug diffusion, and increased gel expansion. Perhaps the real solution for an ideal tamponade agent may involve a paradigm shift away from traditional agents. Mario R. Romano Xun Xu Kenneth K. W. Li

Temperate oceans are inhabited by diverse and temporally dynamic bacterioplankton communities. However, the role of the environment, resources and phytoplankton dynamics in shaping marine bacterioplankton communities at different time scales remains poorly constrained. Here, we combined time series observations (time scales of weeks to years) with molecular analysis of formalin-fixed samples from a coastal inlet of the north-west Atlantic Ocean to show that a combination of temperature, nitrate, small phytoplankton and Synechococcus abundances are best predictors for annual bacterioplankton community variability, explaining 38% of the variation. Using Bayesian mixed modelling, we identified assemblages of co-occurring bacteria associated with different seasonal periods, including the spring bloom (e.g. Polaribacter, Ulvibacter, Alteromonadales and ARCTIC96B-16) and the autumn bloom (e.g. OM42, OM25, OM38 and Arctic96A-1 clades of Alphaproteobacteria, and SAR86, OM60 and SAR92 clades of Gammaproteobacteria). Community variability over spring bloom development was best explained by silicate (32%)--an indication of rapid succession of bacterial taxa in response to diatom biomass--while nanophytoplankton as well as picophytoplankton abundance explained community variability (16-27%) over the transition into and out of the autumn bloom. Moreover, the seasonal structure was punctuated with short-lived blooms of rare bacteria including the KSA-1 clade of Sphingobacteria related to aromatic hydrocarbon-degrading bacteria.

The purpose of this study was to determine the effects of an oral preparation containing hyaluronic acid on osteoarthritic knee joint pain and function as well as changes in inflammatory cytokines, bradykinin, and leptin. We also used heavy water to determine the turnover rates of glycosaminoglycans in synovial fluid. This was a double-blind, randomized, placebo-controlled study of 40 subjects over a period of 3 months. Visual analog scale, Western Ontario McMaster pain, and WOMAC function scores were recorded. Serum and synovial fluid were measured by enzyme-linked immunosorbent assays for inflammatory cytokines, bradykinin, and leptin. In 20 subjects, terminal heavy water ingestion was used for spectral analyses of serum and joint fluid samples. There were statistically significant improvements in pain and function. Both serum and synovial fluid samples showed significant decreases for a majority of inflammatory cytokines, leptin, and bradykinin in the oral hyaluronic acid preparation group. Heavy water analyses revealed a significant decrease in hyaluronic acid turnover in the synovial fluid of the treatment group. A preparation containing hyaluronic acid and other glycosaminoglycans holds promise for a safe and effective agent for the treatment for patients with knee osteoarthritis and who are overweight. Further studies will be required to see whether this is a disease-modifying agent.

The fluorescence excitation spectrum is sometimes used as a proxy for the action spectrum of photosynthesis in phytoplankton. The main assumption behind this approximation is that the shapes of absorption and fluorescence excitation spectra are similar except for the absorption by photoprotective pigments, which do not contribute to the fluorescence spectrum. In this study, we compare the shapes of the absorption and fluorescence spectra in three species of phytoplankton grown at different irradiances: two diatoms (Thalassiosira weissflogii and Chaetoceros sp.) and a cyanophyte (Synechococcus sp.). The contribution to absorption by photoprotective pigments was estimated for each experiment. Results showed that the differences between the shapes of absorption and fluorescence spectra were similar to the estimated absorption by photoprotective pigments only in the case of T. weissflogii. In Synechococcus sp., and to a lesser degree in Chaetoceros sp., the differences between the two types of spectra were larger than the absorption by photoprotective pigments. In the case of Synechococcus sp., the difference between these spectra was apparently due mainly to the extreme imbalance of chlorophyll a distribution between the two photosystems. Chaetoceros sp. seemed to be an intermediate case: a small part of the chlorophyll a of the cell appeared to be exclusively associated with photosystem I and therefore did not contribute to fluorescence. Fluorescence and absorption values were normalized to their values at 545 nm, and the ratio of normalized absorption to normalized fluorescence was computed for the blue (439 nm) and red (676 nm) peaks in the spectra. The results showed that these peak ratios can be used to distinguish between the effects of photoprotective pigments and the arrangement of the photosynthetic apparatus on differences between fluorescence and absorption spectra.

Three trans-Atlantic oceanographic surveys (Nova Scotia to Canary Islands) were carried out during fall 1992 and spring 1993 to describe the large-scale variability in hydrographic, chemical and biological properties of the upper water column of the subtropical gyre and adjacent waters. Significant spatial and temporal variability characterized a number of the biological pools and rate processes whereas others were relatively invariant. Systematic patterns were observed in the zonal distribution of some properties. Most notable were increases (eastward) in mixed-layer temperature and salinity, depths of the nitracline and chlorophyll- a maximum, regenerated production (NH 4 uptake) and bacterial production. Dissolved inorganic carbon (DIC) concentrations, phytoplankton biomass, mesozooplankton biomass and new production (NO 3 uptake) decreased (eastward). Bacterial biomass, primary production, and community respiration exhibited no discernible zonal distribution patterns. Seasonal variability was most evident in hydrography (cooler/fresher mixed-layer in spring), and chemistry (mixed-layer DIC concentration higher and nitracline shallower in spring) although primary production and bacterial production were significantly higher in spring than in fall. In general, seasonal variability was greater in the west than in the east; seasonality in most properties was absent west of Canary Islands (∼20°W). The distribution of autotrophs could be reasonably well explained by hydrography and nutrient structure, independent of location or season. Processes underlying the distribution of the microheterophs, however, were less clear. Heterotrophic biomass and metabolism was less variable than autotrophs and appeared to dominate the upper ocean carbon balance of the subtropical North Atlantic in both fall and spring. Geographical patterns in distribution are considered in the light of recent efforts to partition the ocean into distinct “biogeochemical provinces”.

Background To establish the prevailing state of the ecosystem for the assessment of long-term change, the abundance of microbial plankton in Bedford Basin (Nova Scotia, Canada) is monitored weekly by flow cytometry. Methods Phytoplankton are detected by their chlorophyll autofluorescence. Those that contain phycoerythrin are designated as Synechococcus cyanobacteria or cryptophyte algae according to the intensity of light scatter. Bacteria and viruses are stained with DNA-binding fluorochromes and detected by green fluorescence. Distinction is made between bacterial and viral subpopulations exhibiting high and low fluorescence. Results Time series data are presented for weekly observations from 1991 to 2000. Weekly averages are computed for the complete annual cycle of temperature, salinity, river discharge, nitrate, phosphate, silicate, chlorophyll, total phytoplankton including Synechococcus and cryptophytes, total bacteria including high and low-fluorescence subpopulations, and total viruses including high and low-fluorescence subpopulations. Conclusions The microbial biomass in the surface water of Bedford Basin is dominated by phytoplankton. The spring bloom of phytoplankton represents a maximum in algal biovolume, but not in cell number. Phytoplankton, bacteria, and viruses all attain their annual numerical maxima between the summer solstice and the autumn equinox. A vigorous microbial loop and viral shunt is envisioned to occur in the summer. Cytometry 44:236–246, 2001. © 2001 Wiley-Liss, Inc.

A comparative ecology of chlorophyll, bacteria and picophytoplankton is presented for seven ecological provinces in the North Atlantic. Depth-integrated standing stocks of these biota were measured from boreal polar to subtropical gyral regions. Averaging over all sampling times and locations within each province, it appeared that the integrated biomass of bacteria did not exceed that of phytoplankton in any province. Although this biomass ratio often exceeded unity in surface waters of the subtropical gyral provinces, the ratio for the upper water column as a whole was lowered by the subsurface chlorophyll layer. Bacteria and picophytoplankton, as the potential food resource of micrograzers, appeared to complement each other such that their total biomass did not vary much more than 2-fold amongst the seven provinces. Characteristic parameters of the biotic depth profiles, namely surface concentrations, integrated stocks and depth of maximum, were used to cluster the provinces. The original classification of provinces based on surface chlorophyll fields and characteristic regional physics was reinforced by the inclusion of bacteria and picophytoplankton.

Global abundance of marine bacteria was investigated at the annual climatological scale. In surface waters of diverse marine habitats, the annual average abundances of heterotrophic bacteria and the photosynthetic cyanobacterium Synechococcus are directly related to annual average temperature below 14°C. Notably, average nitrate concentrations at the surface are never high where the temperature is above 14°C. These results suggest that, over the course of a year, temperature is the dominant factor affecting bacterial growth and loss in colder waters. Other factors, such as substrate supply, may be important in warmer waters.

OBJECTIVES. To review the results of patching for amblyopia management in Hong Kong. DESIGN. Retrospective case series. SETTING. Regional hospital, Hong Kong. PATIENTS. Records of all patients attending Paediatric Ophthalmology Clinic at United Christian Hospital, Hong Kong from 1 January 2009 to 31 March 2009 were retrospectively reviewed. Records of all children who underwent patching for amblyopia in the study period were evaluated. RESULTS. The mean age of 50 children (50 eyes) was 4 (standard deviation, 1; range, 2-7) years and mean pretreatment visual acuity was 0.35 (0.15; 0.02-0.63) [~20/60]. The values for mean, standard deviation, and range of treatment duration were 27, 16, 4-67 months respectively, and corresponding values for prescribed patching per day were 4, 1, 2-8 hours. The mean, standard deviation, and range of visual acuity at final post-treatment assessment were 0.66, 0.16, 0.1-1.0 (~20/30), respectively. The overall success rate (ie final visual acuity >0.7 or 20/30) was 62%. Children with moderate amblyopia (20/40-20/80) and severe amblyopia (20/100-20/400) had success rates of 74% and 55%, respectively. The mean visual acuity improvements for moderate and severely amblyopic children were 2.3 lines and 5.8 lines, respectively. The mean, standard deviation, and range of patching prescriptions for moderate and severely amblyopic children were 5, 1, 2-7 hours and 5, 1, 3-6 hours, respectively. Recurrence ensued in 7% of the children with moderate amblyopia and 46% of those with severe amblyopia. Reported compliance was good (>75% of the time) in 68% of the children. CONCLUSION. Occlusion therapy is the mainstay of treatment in Hong Kong. The overall success rate was comparable to that achieved in the Amblyopia Treatment Study. Recurrence was more common in patients with severe amblyopia, for whom maintenance therapy may reduce the risk of recurrence. The duration of treatment was much longer in our locality than in western countries. Reported compliance was suspicious possibly due to traditional cultural contexts. It is important to emphasise compliance to all parents.

The lower trophic level taxa underpin the marine ecosystems of the Pacific Arctic Region (PAR). Recent field observations indicate that range shifts, and changes in the relative abundance of particular taxa have occurred within the last decade. Here we provide a region wide survey of the diversity and distribution of viruses, bacteria, archaea, auto- and heterotrophic protists, as well as metazoan zooplankton and benthic organisms in the PAR. Our aim is to provide a foundation for the assessment of the changes within the lower trophic level taxa of the PAR and to document such change when possible. Sensitivities to the effects of climate change are also discussed. Our vision is to enable data-based predictions regarding ecological succession in the PAR under current climate scenarios, and to deepen our understanding regarding what the future holds for higher trophic level organisms and the carbon cycle.

The concept and methods of ecological diversity in communities were applied to phytoplankton categorized by flow cytometric measurements related to size and chlorophyll content. Each cytometric signature was condensed to single numerical values indicative of diversity and evenness. Measurements pooled from studies disparate in temporal and spatial scales indicated greater chlorophyll biomass and primary production with greater cytometric diversity and evenness. Future development of these ideas may help link biological oceanographic processes with patterns established through ecological processes at the community level.

Idiopathic juxtafoveal telangiectasis (IJT) is one of the primary retinal telangiectasia that can result in visual impairment attributed to resultant cystoid macular oedema and rarely, choroidal neovascularization. The authors herein report successful treatment using intravitreal triamcinolone acetonide in a case of unilateral IJT that did not respond to prior laser photocoagulation. Serial optical coherence tomography was used to monitor the effectiveness of intravitreal triamcinolone acetonide in the treatment of IJT.

A 15-year-old boy was referred for reduced left-eye vision 2 weeks after a blunt trauma. The presenting visual acuities were 6/12 in the right eye and counting fingers in the left eye. Examination revealed a white cataract in the left eye with loss of convexity of the anterior lens surface. Ultrasonography confirmed a ruptured posterior capsule. Removal of the lens was approached via a clear corneal cataract incision. After insertion of an anterior chamber maintainer and capsulorhexis was performed, the lens matter was removed with vitreous cutter via the cataract incision, using its cutting and aspirating modes. A foldable intraocular lens (IOL) was inserted in the capsular bag. Visual acuity improved to 6/18 1 month after surgery and further improved to 6/6 at 6 months. The IOL was stable with no decentration or posterior capsule opacification.

Phytoplankton plays a critical role in the uptake of atmospheric carbon dioxide by the ocean, and is comprised of a spectrum of cell sizes that are strongly associated with different oceanographic conditions. Studies suggest that the ocean will become increasingly stratified in response to a warming climate, limiting nutrient exchange to the upper sunlit ocean and favouring small cells able to grow in warmer, nutrient poor conditions. Here we show that, in a temperate shelf sea, a summertime population of numerically abundant small cells accounts for approximately 20% of annual carbon uptake. These small cells are not well represented by chlorophyll a – the ubiquitously used proxy of phytoplankton biomass – but rather, are strongly correlated with surface water temperature. Given the persistent near-zero nutrient concentrations during the summer, it appears that small cells drive carbon overconsumption, and suggest that their role in carbon fixation will become increasingly important in a warming ocean.

The increase in the areal extent of the subtropical gyres over the past decade has been attributed to a global tendency towards increased water-column stratification. Here, we examine how vertical stratification governs the community structure of the picophytoplankton that dominate these vast marine ecosystems. We analysed phytoplankton community composition in the three Southern Subtropical basins of the Pacific, Indian and Atlantic Oceans using a variety of methods and show that the distributions of picocyanobacteria and photosynthetic picoeukaryotes (PPEs) are strongly correlated with depth and strength of vertical mixing: the changes in community structure occur at various taxonomic levels. In well-mixed waters, PPEs, in particular haptophytes, dominate, whereas in strongly stratified waters, picocyanobacteria of the genus Prochlorococcus are prevalent, regardless of whether the relative contributions to total biomass are assessed in terms of pigment or of carbon. This ecological diochotomy within the picophytoplankton supports the hypothesis that genomic streamlining provides a selective advantage for Prochlorococcus in highly stable, oligotrophic systems, but may restrict their ability to dominate in regions subject to dynamic mixing.

A carbon flux study was carried out off the coast of Morocco, at 31°N, in a region characterized by the presence of a persistent cyclonic eddy. Two short-term (4 and 3 day) deployments of free-floating sediment traps were combined with water column sampling and rate process measurements as the ship followed the traps. For a period of 36 h between trap deployments, a hydrographic section was run along 31°30'N as part of a larger scale survey being carried out simultaneously on the R.V. A. von Humboldt. The first trap deployment was near the eastern margin of the eddy and the traps moved to the north and west in a frontal jet associated with its northern boundary. After the second deployment, which was at the recovery point of the first, the traps moved to the west and then to the southwest. Throughout the study, chlorophyll concentrations varied between 27 and 125 mg m−2 (0–100 m), with highest concentrations in the upwelled water nearest the coast and in upwelled water generated within the cyclonic eddy. Particulate organic carbon (POC) and particulate organic nitrogen (PON) concentrations were relatively uniform (13.6±1.8 and 1.63±28 g m−2 with phytoplankton carbon accounting for 16–85% of total POC. Bacterial carbon was ∼ 5% of total POC and mesozooplankton carbon concentrations were equivalent to ∼9% of total POC. Microzooplankton biomass was not assessed but POC:PON ratios in the water column were often high, suggesting there was sometimes a large detrital component in the POC. Primary production rates varied between 1.0 and 2.5 g C m−2 day−1. Bacterial consumption accounted for ∼50% of primary production. Metabolic rates suggested that copepods were ingesting more than 0.4 g C m−2 day−1. while filtration rates suggested that ingestion of phytoplankton carbon was only ∼0.2 g C m−2day−1, even when phytoplankton constituted ∼85% of the POC. f-ratios (based on uptake rates for 15N-nitrate and ammonia) were between 0.1 and 0.4, and excretion by mesozooplankton could account for ∼ 40% of the daily ammonium uptake by phytoplankton. HPLC pigment analysis showed that when chlorophyll biomass was high, diatoms were dominant, whereas when it was low, small prymnesiophytes, chlorophytes and diatoms were all important. The composition of the fluoresecent pigments in material in the sediment traps indicated that intact phytoplankton and copepod faecal pellets were the main sources but the relative rates of sedimentation of pigment, POC and PON for the two trapping periods did not reflect differences that were observed in the overlying water column. This was likely to be the result of spatial heterogeneity and strong horizontal currents heterogeneity and strong horizontal currents within the euphotic zone. Thus, material collected at 100 m probably did not originate in the water column immediately overlying the traps and trapping efficiencies might also have been variable.

Spontaneous rupture of hepatocellular carcinoma with intraperitoneal haemorrhage is a life-threatening condition. Intraperitoneal spread of the tumour after rupture occurs uncommonly. We report two cases of curative management for recurrent tumour implantation after ruptured hepatocellular carcinoma. The two patients presented with ruptured hepatocellular carcinoma and were treated with transarterial embolisation in the acute episode. Interval partial hepatectomy of the carcinoma was performed after the acute episodes. The first patient presented with a large epigastric mass 2 years after rupture. The mass was found to be adherent to the stomach and omentum. Distal gastrectomy was performed. The second patient presented with a right upper quadrant mass 4 months after rupture, and had a huge tumour attached to the ascending colon. Right hemicolectomy and omentectomy were performed. On histological examination, both tumours were confirmed to be recurrent hepatocellular carcinomas with clear surgical margins. After resection, both patients had no tumour recurrence at 1 year and 3 years, respectively.

The blue-excitable nucleic acid-binding fluorochromes, TOTO and TO-PRO, were used to stain bacteria in marine plankton communities. Flow cytometric counts of cells stained with these dyes agreed well with counts made by epifluorescence microscopy of DAPI-stained cells. We have used these new dyes in a study of bacteria from various waters in the North Atlantic and the eastern Mediterranean. The results indicate a distinction among bacterial groups of different fluorescence intensities (apparent DNA content). At large spatial and temporal scales, about half of the variation in the percentage of bacteria with high apparent DNA content (termed group II bacteria) could be explained by the variation in chlorophyll. Further, the apparent mean DNA content of group II bacteria was also correlated with chlorophyll.

Purpose Diabetic retinopathy (DR) is a common microvascular complication of type 2 diabetes (T2DM). Genome-wide association studies (GWAS) had identified novel DR-susceptibility genetic variants in various populations. We examined the associations of these DR-associated single nucleotide polymorphisms (SNPs) with severe DR in a Chinese T2DM cohort. Methods Cross-sectional case-control studies on sight-threatening DR (STDR) and proliferative DR (PDR) were performed. We genotyped 38 SNPs showing top association signals with DR in previous GWAS in 567 STDR cases, including 309 with PDR and 1490 non-DR controls. Multiple logistic regression models with adjustment for conventional risk factors, including age, sex, duration of diabetes, and presence of hypertension, were employed. Results The strongest association was found at INSR rs2115386, an intronic SNP of INSR: Padjusted = 9.13 × 10-4 (odds ratio [OR],1.28; 95% confidence interval [95%CI], 1.11-1.48) for STDR, and Padjusted= 1.12 × 10-4 (OR [95%CI],1.44 [1.20-1.74]) for PDR. rs599019 located downstream of COLEC12 (Padjusted = 0.019; OR [95%CI],1.19 [1.03-1.38]) and rs4462262 located at an intergenic region between ZWINT and MRPS35P3 (Padjusted = 0.041; OR [95%CI],1.38[1.01-1.89]) also were significantly associated with STDR, but not with PDR alone. On the other hand, MYT1L-LOC729897 rs10199521 (Padjusted = 0.022; OR [95%CI],1.25 [1.03-1.51]) and API5 rs899036 (Padjusted = 0.049; OR [95%CI],1.36 [1.00-1.85]) showed significant independent associations only with PDR. Similar results were obtained when hemoglobin A1c also was included in the adjustment models. Conclusions We demonstrated the significant and independent associations of several GWAS-identified SNPs with DR in Chinese T2DM patients with severe DR. The findings on INSR rs2115386 are supportive of the role of insulin resistance, or the compensatory hyperinsulinemia, in the pathogenesis of DR.

Purpose To report a case of laser-induced choroidal neovascularization (CNV) treated with verteporfin photodynamic therapy. Design Interventional case report. Methods A patient developed CNV in the macular area of the left eye 2 years following grid laser for macular edema secondary to branch retinal vein occlusion. Results The CNV was controlled with one session of photodynamic therapy. Lesion decreased in size, contracting to a smaller subretinal fibrotic scar. Vision improved from 20/200 to 20/100, and there was no recurrence at 2-year follow-up. No complications were encountered. Conclusion Laser-induced CNV can be safely and effectively treated by photodynamic therapy.

There is still no consensus on the ideal management of common bile duct (CBD) stones. This article aims to review the management of concomitant gallbladder stones and CBD stones in the laparoscopic era.A PubMed database search was performed to identify MEDLINE articles from 1986 to 2010 using the key terms "common bile duct stones,""cholecystectomy,""bile duct exploration,""ERCP" (endoscopic retrograde cholangiography), and "endoscopic sphincterotomy."There were five randomized comparative trials (RCT) comparing sequential preoperative ERCP and laparoscopic cholecystectomy (LC) to laparoscopic common bile duct exploration (LCBDE). Two RCTs showed similar stone clearance rates and shorter hospital stays in the LCBDE group, while three RCTs showed similar stone clearance rates and hospital stays in sequential preoperative ERCP, LC and LCBDE groups. There were two RCTs comparing LCBDE to sequential LC and postoperative ERCP. One showed similar stone clearance rate and shorter hospital stay in LCBDE group, while the other showed similar stone clearance rate and hospital stay. There were three RCTs comparing sequential preoperative ERCP and LC against LC with intraoperative ERCP. All three studies showed similar stone clearance rates and shorter hospital stays in the intraoperative ERCP group. There was only one RCT comparing sequential preoperative ERCP and LC against sequential LC and postoperative ERCP. This showed a similar stone clearance rate and shorter hospital stay in the postoperative ERCP group.Different management approaches of concomitant gallbladder stones and CBD stones were equivalent in efficacy. However, one-stage management had the advantage of providing a shorter hospital stay.

Given the limitation of surgical access and instrumentation, pure NOTES technique currently appears challenging for colorectal surgery. As such, we would like to determine the technical feasibility and clinical results of hybrid NOTES right hemicolectomy with transrectal extraction of specimen.After the right-sided colon was fully mobilized and vessels ligated, bowel resection and intracorporeal side-to-side ileocolic anastomosis were performed with endostaplers. The Transanal Endoscopic Operations device was inserted transanally. The resected specimen was removed via the Transanal Endoscopic Operations device through an enterotomy made over the anterior wall of the upper rectum.The operation was performed on a 42-year-old woman and lasted 120 minutes; blood loss was 30 mL. The patient had an uneventful recovery and was discharged on postoperative day 5. The median pain score was 2 (range, 2-3). Our preliminary experience shows that hybrid NOTES right hemicolectomy is safe and feasible. The technique eliminates the need for mini-laparotomy in patients undergoing laparoscopic right hemicolectomy, and it offers promise in this era of minimally invasive surgery.

The most dreaded complication of a colonoscopy is colonic perforation. Perforation of the small bowel following colonoscopy is extremely rare, especially if the procedure was performed without any therapeutic intervention. Herein we report a case of jejunal perforation following a routine surveillance colonoscopy. A literature review focusing on the proposed mechanism of perforation is included.

Laparoscopic inguinal hernia repair is currently one of the most commonly performed minimally invasive surgical procedures. In recent years, single-incision operations have been developed to further reduce the invasiveness of the surgery. Herein, we report our early experience with single-incision laparoscopic inguinal hernia repair in Asia, with both the transabdominal preperitoneal (TAPP) and totally extraperitoneal (TEP) approaches.This is a retrospective review of prospectively collected data on a cohort of consecutive patients with inguinal hernia who underwent single-incision laparoscopic inguinal hernia repair in a minimal access surgical center in Hong Kong between January 2010 and January 2011.Our cohort consists of 15 patients who underwent single-incision laparoscopic inguinal hernia; 13 were unilateral and two were bilateral hernias. The mean age was 59.8 years old (range, 28-74 years). The overall mean operative time was 59.53 min (range, 25-120 min). For unilateral hernia repair, the mean operative time was 56 min (range, 25-75 min) and 48.5 min (range, 41-55 min) for TAPP and TEP, respectively. In all cases single-incision laparoscopic hernia repair was successfully performed, no additional trocars were required, and there were no conversions to conventional laparoscopic or open inguinal hernia repair. All patients were discharged on the same day as the procedure.Single-incision laparoscopic inguinal hernia is feasible in both TEP and TAPP approaches. The procedure should be performed by laparoscopic surgeons with a high level of experience in single-incision surgery. Further randomized trials should be performed to evaluate the full potential and clinical application of single-incision TAPP and TEP.

Laparoscopic colectomy for colorectal cancer is associated with definite short-term benefits, and is increasingly practised worldwide. The limitations of a pure laparoscopic approach include a relative lack of tactile feedback and long procedural time. Hand-assisted laparoscopic surgery was introduced in an attempt to facilitate operation by improving the tactile sensation. To date, there is no consensus as to which approach is better. Herein we conducted a randomized controlled trial comparing hand-assisted laparoscopic colectomy (HALC) with total laparoscopic colectomy (TLC) in the management of right-sided colonic cancer.Adult patients with carcinoma of the caecum and ascending colon were recruited and randomized to undergo either HALC or TLC. Measured outcomes included operative time, blood loss, conversion rate, postoperative morbidities, postoperative pain, length of hospital stay, disease recurrence and patient survival.Sixty patients (HALC=30, TLC=30) were recruited. The two groups were comparable with regard to age, gender distribution, body mass index and final histopathological staging. No difference was observed between the groups in terms of operating time, conversion rate, operative blood loss, pain score and length of hospital stay. With a median follow-up of 27 to 33 months, no difference was observed in terms of disease recurrence, and the 5-year survival rates remained similar (83%vs 80%, P=0.923).HALC is safe and feasible, but it does not show any significant benefits over TLC in terms of operating time and conversion rate. Routine use of the hand-assisted laparoscopic technique in right hemicolectomy is therefore not recommended.

Malignancy-associated chylothorax is a rare manifestation with uncertain characteristics and clinical significance. We segregated 18 patients into malignant lymphoma (n= 11) and solid malignancy (n= 7) groups to analyse the characteristics, treatment response and prognostic value of malignancy-associated chylothorax. Diagnosis of chylothorax was confirmed by a triglyceride concentration of110 mg/dL or by the presence of chylomicrons in the pleural effusion. Concentrations of glucose, protein and lactate dehydrogenase did not differ significantly between the malignant lymphoma and solid malignancy groups. Although not statistically significant (P= 0.25), 90.9% malignant lymphoma patients and 57.1% solid malignancy patients had exudates. The cytology diagnostic rate in the malignant lymphoma and solid malignancy groups was 20.0% and 33.3% respectively (P0.99). After chemotherapy, six malignant lymphoma patients achieved complete remission, with simultaneous chylothorax disappearance. The overall survival rate at 12 and 24 months in the malignant lymphoma group was 54.5% and 36.4% respectively, while that in the solid malignancy group was 35.7% and 0% respectively. Malignant lymphoma was the chief cause of chylothorax in our cohort. Effective lymphoma treatment, lacking supplementary interventions, is essential for treating chylothorax in malignant lymphoma patients. Chylothorax indicates extremely limited life expectancy for solid malignancy patients.

We compiled a database of bacterial abundance of 39 766 data points. After gridding with 1° spacing, the database covers 1.3% of the ocean surface. There is data covering all ocean basins and depth except the Southern Hemisphere below 350 m or from April until June. The average bacterial biomass is 3.9 ± 3.6 μg l−1 with a 20-fold decrease between the surface and the deep sea. We estimate a total ocean inventory of about 1.3 × 1029 bacteria. Using an average of published open ocean measurements for the conversion from abundance to carbon biomass of 9.1 fg cell−1, we calculate a bacterial carbon inventory of about 1.2 Pg C. The main source of uncertainty in this inventory is the conversion factor from abundance to biomass. http://doi.pangaea.de/10.1594/PANGAEA.779142

Currently transabdominal pre-peritoneal and totally extraperitoneal repairs are the two standard laparoscopic approaches for groin hernia repair. However, they are still largely reserved for uncomplicated elective cases. To determine whether laparoscopic groin hernia repair can achieve similar results for acute strangulated hernias as laparoscopic cholecystectomy for acute cholecystitis, we analyzed and compared the results of emergency laparoscopic surgery and open repair for strangulated groin hernias performed by our team over the past 4 years.This is a retrospective analysis of prospectively collected data. We analyzed the results of patients admitted between January 2007 and January 2011 who were diagnosed with acute strangulated groin hernia and underwent emergency open or laparoscopic hernia repair during the same admission. Patients' demographic details, mode of presentation, type of hernia, intraoperative findings, operative time, postoperative course and complications were compared.In total, 188 patients fulfilled the criteria for emergency surgical repair of strangulated groin hernias; 57 received laparoscopic and 131 received open repairs. The mean operative time was 79.82 ± 29.571 min and 80.75 ± 35.161 min, respectively. More laparotomies were performed in the open group (19 vs 0). The wound infection rate was significantly higher in the open group (12 vs 0). The mean hospital stay was shorter in the laparoscopic group (4.39 days vs 7.34 days). There was no mesh infection in either group. Recurrence occurred one case in the laparoscopic group and in three cases in the open group.Emergency laparoscopic repair for strangulated groin hernias is feasible and appears to have a lower morbidity relative to open repair. Further study should be performed to evaluate its full potential.

To review the site of involvement, clinical presentation, and treatment outcome of patients having immunoglobulin G4-related sclerosing disease in a local regional hospital.Retrospective case series.Pamela Youde Nethersole Eastern Hospital, Hong Kong.All patients with a diagnosis of immunoglobulin G4-related sclerosing disease in the hospital diagnosed in the period from April 2008 to March 2010.A total of 12 patients with involvement of various organs were identified. There was a male predominance (male-to-female ratio=5:1). The mean age at diagnosis was 65 years. The salivary glands, biliary tract, pancreas, and cervical lymph nodes were the commonest involved sites. The immunoglobulin G4 level was elevated in 83% of the patients. Patients usually appeared to respond well to steroid treatment.Immunoglobulin G4-related sclerosing disease is a systemic disease and can involve various systems.

Laparoscopic surgery for locally advanced tumours with extramural involvement is still controversial. It is believed that laparoscopic excision of T4 cancers is technically difficult and may result in prolonged operative time, increased conversion rate, added postoperative morbidity, and suboptimal oncological clearance.Our unit has been practising laparoscopic colorectal surgery since 1992, and all data are entered into a database prospectively. Since 1999 we have routinely used the laparoscopic approach for colorectal cancer resections. Data regarding patients with a histologically T4 cancer operated on between 1999 and 2008 were analysed. Outcomes included operating time, conversion rate, postoperative complications and oncological outcome.Over a 10-year period, 146 patients (male 75) with a T4 cancer underwent laparoscopic resection. The median operating time was 125 (range, 46-285) min and the median blood loss was 50 (0-1800) ml. The conversion rate was 16%. Six (4.1%) patients experienced anastomotic leakage. The median number of lymph nodes harvested was 13 (2-40). One hundred and two (70%) patients underwent curative resection. The recurrence rates were 41% and 53% for stage II and III patients, respectively. Four (3.9%) patients had local recurrence. At a median follow up of 18 (1-118) months, the overall survival was 25 months, with median overall survival for patients with stage II, III and IV disease being 63, 36 and 12 months, respectively.Laparoscopic colectomy in histologically T4 cancer is safe. Oncological outcomes remain satisfactory. Based on our data, provided expertise is available, patients with locally advanced tumours should not be excluded from a laparoscopic approach.

This is a non-randomized comparative trial designed to compare the results of pancreaticoduodenectomy with internal pancreatic stenting versus no stenting for pancreaticojejunal (PJ) anastomosis after pancreaticoduodenectomy.Between January 1999 and March 2008, a total of 49 consecutive patients undergoing pancreaticoduodenectomy with duct-to-mucosa PJ anastomosis with, or without an internal stent were evaluated.The 2 groups were comparable in demographic data, underlying pathologies, and pancreatic stump condition. Four patients (16.7%) in the stented group, and four patients (16%) in the non-stented anastomosis group had pancreatic fistula. There was no significant difference in pancreatic fistula rate between two groups. No surgical reintervention was necessary in all the patients with pancreatic fistulas. There were also no significant differences in operating time (mean, 270.5 minutes vs. 263.6 minutes), intra-operative blood loss (mean, 772.9 ml vs. 665.3 ml), overall morbidity (45.8% vs. 40%) and hospital mortality (4.2% vs. 4.0%). The mean hospital stay after surgery was 34 days in stented group and 21.5 days in non-stented group.Internal stenting of pancreatic duct could not reduce pancreatic fistula rate after pancreaticoduodenectomy.

The immunoreactants detected by direct immunofluorescence (DIF) from the skin of patients with lupus erythematosus (LE) were related to disease subtypes and skin morphology. Male patients presented more frequently with discoid rashes and females with malar rashes. We investigated the differences in immunoreactants in skin lesions between male and female LE patients.The DIF records of 186 LE patients were reviewed and analysed.Among 186 patients (133 female and 53 male), 54 had cutaneous LE (CLE) and 132 had systemic LE (SLE). In the CLE group, eight of 33 (24.2%) women were DIF+ versus nine of 21(42.9%) men (p=0.23). In the SLE group, 49 of 100 (49%) women were DIF+ versus 17 of 32 (53.1%) men (p=0.84). The p-value was 0.01 when comparing DIF incidence between female CLE and SLE patients. IgM and complement component 3 (C3) were present in 84.2% and 52.6% of DIF+female patients, respectively, and both were comparable between genders (p0.05). However, IgG was observed only in eight of 57 female patients, and in 10 of 26 male patients (p=0.02). Among DIF+CLE patients, IgG was detected in none of the eight female versus three of nine male patients.Detection of immunoreactants in skin had no gender bias in CLE or SLE, but among women, it was probably lower in CLE than SLE. IgM and C3 were the most frequent immunoreactants in skin with no gender disparity, whereas IgG in female patients was lower than in males.

Current imaging modalities used in the evaluation of Vogt-Koyanagi-Harada (VKH) disease include ultrasound, fluorescein angiogram, indocyanine green angiography, and optical coherence tomography (OCT). However, they all fail to give detailed information on the ultrastructural changes of the choroid. A recent technique using OCT termed "enhanced depth imaging" produces high-resolution cross-sectional images of the whole thickness of the choroid. The purpose of the study was to describe a novel imaging finding in the choroid in cases of VKH uveitis and to assess for interobserver agreement of this new physical sign.This is an age-matched, sex-matched, and spherical equivalent-matched, case-control, cross-sectional study. Six VKH patients in acute and convalescent stages underwent choroidal imaging using enhanced depth imaging spectral-domain OCT imaging. A horizontal enhanced depth imaging spectral-domain OCT scan across the fovea was selected for each eye and was compared with a scan from an age-matched, sex-matched, and spherical equivalent-matched control subject. A loss of focal hyperreflectivity, represented by a decrease in the number of hyperreflective dots in the inner choroid, was observed. This finding was assessed for interobserver agreement using five masked observers. Mean observed agreement and multirater kappa statistics (κ) were calculated. The average choroidal thickness was also calculated and compared among acute-phase VKH patients, convalescent-phase VKH patients, and control subjects.There was a significant loss of focal hyperreflectivity in the inner choroid of VKH patients compared with control subjects in both acute and convalescent stages. Analysis revealed substantial interobserver agreement on this finding. The mean observed agreement was 95%, and the overall kappa coefficient (κ) was 0.80 (P0.01). The choroid of acute-phase VKH patients was thicker than that of convalescent-phase patients by 151 μm (P = 0.043) and control subjects by 137 μm (P = 0.001). There was no statistically significant difference in thickness between convalescent eyes and controls.Enhanced depth imaging spectral-domain OCT highlights a loss of focal hyperreflectivity in the inner choroid of eyes with VKH, a feature that is consistently observed by independent masked observers. The presence of this feature in both acute and convalescent phases could represent permanent structural change to small choroidal vessels caused by VKH uveitis.

In the Gulf of Maine area (GoMA), as elsewhere in the ocean, the organisms of greatest numerical abundance are microbes. Viruses in GoMA are largely cyanophages and bacteriophages, including podoviruses which lack tails. There is also evidence of Mimivirus and Chlorovirus in the metagenome. Bacteria in GoMA comprise the dominant SAR11 phylotype cluster, and other abundant phylotypes such as SAR86-like cluster, SAR116-like cluster, Roseobacter, Rhodospirillaceae, Acidomicrobidae, Flavobacteriales, Cytophaga, and unclassified Alphaproteobacteria and Gammaproteobacteria clusters. Bacterial epibionts of the dinoflagellate Alexandrium fundyense include Rhodobacteraceae, Flavobacteriaceae, Cytophaga spp., Sulfitobacter spp., Sphingomonas spp., and unclassified Bacteroidetes. Phototrophic prokaryotes in GoMA include cyanobacteria that contain chlorophyll (mainly Synechococcus), aerobic anoxygenic phototrophs that contain bacteriochlorophyll, and bacteria that contain proteorhodopsin. Eukaryotic microalgae in GoMA include Bacillariophyceae, Dinophyceae, Prymnesiophyceae, Prasinophyceae, Trebouxiophyceae, Cryptophyceae, Dictyochophyceae, Chrysophyceae, Eustigmatophyceae, Pelagophyceae, Synurophyceae, and Xanthophyceae. There are no records of Bolidophyceae, Aurearenophyceae, Raphidophyceae, and Synchromophyceae in GoMA. In total, there are records for 665 names and 229 genera of microalgae. Heterotrophic eukaryotic protists in GoMA include Dinophyceae, Alveolata, Apicomplexa, amoeboid organisms, Labrynthulida, and heterotrophic marine stramenopiles (MAST). Ciliates include Strombidium, Lohmaniella, Tontonia, Strobilidium, Strombidinopsis and the mixotrophs Laboea strobila and Myrionecta rubrum (ex Mesodinium rubra). An inventory of selected microbial groups in each of 14 physiographic regions in GoMA is made by combining information on the depth-dependent variation of cell density and the depth-dependent variation of water volume. Across the entire GoMA, an estimate for the minimum abundance of cell-based microbes is 1.7×10(25) organisms. By one account, this number of microbes implies a richness of 10(5) to 10(6) taxa in the entire water volume of GoMA. Morphological diversity in microplankton is well-described but the true extent of taxonomic diversity, especially in the femtoplankton, picoplankton and nanoplankton--whether autotrophic, heterotrophic, or mixotrophic, is unknown.

In various North Atlantic sites, the rate of dark 14C fixation by microbial plankton was significantly correlated with the rate of light 14C fixation, with the rate of bacterial [7H]thymidine incorporation, and with chlorophyll biomass. For plankton sampled near the sea surface (~5 m) and at the depth of the maximum light 14C fixation, the median value for the ratio of dark to light fixation was only 1%. At the depth of the subsurface chlorophyll maximum where less light was available, the median value for this ratio was still quite low at 7%. Our results confirm early claims that generally in the oceans, including oligotrophic regions where plankton biomass is low, dark 14C fixation is high in relation to light fixation only at depths where photosynthesis is severely limited by light. We infer that direct 14C fixation by both bacteria and phytoplankton are significant processes that contribute to measured 14C fixation in opaque bottles during 12 h dawn-to-dusk incubations.

During the 1989 spring bloom in the western North Atlantic, we estimated the biomass and productivity of bacteria and phytoplankton at two sites (40 and 45°N) representing different water masses. At 40°N, almost all of the phytoplankton carbon could be accounted for by photosynthetic nanoplankton and picoplankton; in contrast, at 45°N, only about half was thus accounted, implying a substantial contribution by photosynthetic microplankton. At both sites, bacterial abundance was quite high (up to 2 × 109 cells l−1), and the rates of bacterial production assessed by incorporation of [3H]thymidine (up to 8 pmol l−1 h−1) and [3H]leucine (up to 240 pmol l−1h−1) were significant. Specific growth rates of bacteria based on [3H]thymidine incorporation were 0.08–0.25 day−1. Taken together, our measurements and assumptions implied a demand for primary production in the order of 16–36% over the euphotic zone or 24–78% over the upper 100 m in the water column. We conclude that ultraphytoplankton and bacteria played significant roles in the flux of carbon during the 1989 North Atlantic spring bloom.

Two Atlantic (SARG and NATL1) strains and one Mediterranean (MED) strain of Prochlorococcus sp., a recently discovered marine, free-living prochlorophyte, were grown over a range of "white" irradiances (lg) and under low blue light to examine their photoacclimation capacity. All three strains contained divinyl (DV) chlorophylls (Chl) a and b, both distinguishable from "normal" Chls by their red-shifted blue absorption maximum, a Chl c-like pigment at low concentration, zeaxanthin, and [alpha]-carotene. The presence of two phaeophytin b peaks in acidified extracts from both Atlantic strains grown at high lg suggests that these strains also had a normal Chl b-like pigment. In these strains, the total Chl b to DV-Chl a molar ratio decreased from about 1 at 7.5 [mu]mol quanta m-2 s-1 to 0.4 to 0.5 at 133 [mu]mol quanta m-2 s-1. In contrast, the MED strain always had a low DV-Chl b to DV-Chl a molar ratio, ranging between 0.13 at low lg and 0.08 at high lg. The discrepancies between the Atlantic and MED strains could result from differences either in the number of light-harvesting complexes (LHC) II per photosystem II or in the Chl b-binding capacity of the apoproteins constituting LHC II. Photosynthesis was saturated at approximately 5 fg C(fg Chl)-1 h-1 or 6 fg C cell-1 h-1, and growth was saturated at approximately 0.45 d-1 for both MED and SARG strains at 18[deg]C, but saturating irradiances differed between strains. Atlantic strains exhibited increased light-saturated rates and quantum yield for carbon fixation under blue light.

An investigation of the spring bloom was carried out in the western North Atlantic (40–50°W) as one component of the multi-nation Joint Global Ocean Flux Study (JGOFS) North Atlantic Bloom Experiment (NABE). The cruise track included an extended hydrographic section from 32 to 47°N and process studies at two week-long time-series stations at 40 and 45°N. Biological and chemical data collected along the transect indicated that the time-series stations were located in regions where the spring bloom was well developed; algal biomass was high and surface nutrient concentrations were reduced from maximum wintertime levels. Despite similarities in the vertical structure and magnitude of phytoplankton biomass and productivity, the two stations clearly differed in physical, chemical and other biological characteristics. Detailed depth profiles of the major autotrophic and heterotrophic microplankton groups (bacteria, phytoplankton, microzooplankton) revealed a strong vertical coherence in distribution at both sites, with maximum concentrations in the upper 50 m being typical of the spring bloom. Ultraplankton (< 10 μm) were an important component of the primary producers at 40°N, whereas larger netplankton (diatoms, dinoflagellates) were more important at 45°N. Silicate depletion was clearly evident in surface waters at 45°N, where diatoms were most abundant. Despite the relative importance of diatoms at 45°N, dinoflagellates dominated the biomass of the netplankton at both sites; however, much of this community may have been heterotrophic. Bacterial biomass and production were high at both stations relative to phytoplankton levels, particularly at 45°N, and may have contributed to the unexpectedly high residual ammonium concentrations observed below the chlorophyll maximum layer at both stations. Microzooplankton grazing dominated phytoplankton losses at both stations, with consumption as high as 88% of the daily primary production. Grazing losses to the mesozooplankton, on the other hand, were small (

To compare the use of endorectal plus phased-array coils with use of phased-array coil alone with respect to the accuracy of magnetic resonance imaging for detecting mesorectal involvement of rectal cancer.Retrospective study.A tertiary referral centre in Hong Kong.Ethnic Chinese patients with rectal adenocarcinoma who underwent staging magnetic resonance imaging during the years 2003 to 2008 in our centre were selected; those who received preoperative neoadjuvant therapy were excluded. Unless otherwise contra-indicated, endorectal coils have been used since 2006.Magnetic resonance images were retrieved and reviewed by two radiologists blinded to the pathological results. The radiological findings were then correlated with the pathological reports to determine diagnostic accuracy.A total of 50 patients were studied; 13 of the examinations were in patients having an endorectal coil. The overall accuracy of magnetic resonance imaging in detecting mesorectal tumour involvement was 80%. Subgroup analysis showed higher accuracy in the group with endorectal coils than in those with phased-array coils alone. Over-detection of mesorectal involvement was noted in 12% of the cases, with lower rate being observed in patients with endorectal coils. Underdetection of mesorectal tumour involvement was only noted in the group without endorectal coils. With the use of endorectal coils, the sensitivity reached 100% and the specificity increased to 86%.Use of endorectal coil in staging magnetic resonance imaging of the rectum improves diagnostic accuracy. Whenever feasible, endorectal coil use is therefore recommendable to enhance diagnostic accuracy. The study results substantiate the understanding of staging by magnetic resonance imaging of rectal cancer in the local Chinese population.

Background: We describe a case of intraoperative fracture of phacoemulsification sleeve during phacoemulsification surgery. Case presentation. Phacoemulsification surgery was performed in the left eye of a 58-year-old lady with grade II nuclear sclerosis & grade I cortical cataract. Towards the end of quadrant removal, there was anterior chamber instability with impaired followability of nuclear fragments. The distal part of the fractured sleeve remained inside the anterior chamber upon removal of the phacoemulsification probe. The retained sleeve was retrieved with a pair of forceps through the corneal incision site, which did not require widening. There was no missing fragments retained intraocularly and the patient had an uneventful recovery with vision of 20/25 at three months post-operatively. Conclusion. Phacoemulsification sleeve fracture is an uncommon complication. With early identification of this condition and proper management, major complications can be avoided. © 2010 Shum et al; licensee BioMed Central Ltd., published_or_final_version

Dropped gallstones due to accidental perforation of gallbladder wall during laparoscopic cholecystectomy are often encountered. However, dropped gallstones as nidus of infection with subsequent abscess formation is a rare complication of laparoscopic cholecystectomy (0.3%). Most of the reported cases of complicated dropped stones required open surgical drainage. Minimally invasive measures were less frequently employed. We report a case of dropped gallstones that were removed endoscopically through a percutaneous drainage tract.