Life strategy of Antarctic silverfish promote large carbon export in Terra Nova Bay, Ross Sea

Antarctic silverfish Pleuragramma antarcticum is the most abundant pelagic fish in the High Antarctic shelf waters of the Southern Ocean, where it plays a pivotal role in the trophic web as the major link between lower and higher trophic levels. Despite the ecological importance of this species, knowledge about its role in the biogeochemical cycle is poor. We determine the seasonal contribution of Antarctic silverfish to carbon flux in terms of faeces and eggs, from samples collected in the Ross Sea. We find that eggs and faeces production generate a flux accounting for 41% of annual POC flux and that the variability of this flux is modulated by spawning strategy. This study shows the important role of this organism as a vector for carbon flux. Since Antarctic silverfish are strongly dependent on sea-ice, they might be especially sensitive to climatic changes. Our results suggest that a potential decrease in the biomass of this organism is likely to impact marine biogeochemical cycles, and this should be factored in when assessing Southern Ocean carbon budget.

Scoping intergenerational effects of nanoplastic on the lipid reserves of Antarctic krill embryos

Antarctic krill (Euphausia superba) plays a central role in the Antarctic marine food web and biogeochemical cycles and has been identified as a species that is potentially vulnerable to plastic pollution. While plastic pollution has been acknowledged as a potential threat to Southern Ocean marine ecosystems, the effect of nanoplastics (<1000 nm) is poorly understood. Deleterious impacts of nanoplastic are predicted to be higher than that of larger plastics, due to their small size which enables their permeation of cell membranes and potentially provokes toxicity. Here, we investigated the intergenerational impact of exposing Antarctic krill to nanoplastics. We focused on whether embryonic energy resources were affected when gravid female krill were exposed to nanoplastic by determining lipid and fatty acid compositions of embryos produced in incubation. Embryos were collected from females who had spawned under three different exposure treatments (control, nanoplastic, nanoplastic + algae). Embryos collected from each maternal treatment were incubated for a further 6 days under three nanoplastic exposure treatments (control, low concentration nanoplastic, and high concentration nanoplastic). Nanoplastic additions to seawater did not impact lipid metabolism (total lipid or fatty acid composition) across the maternal or direct embryo treatments, and no interactive effects were observed. The provision of a food source during maternal exposure to nanoplastic had a positive effect on key fatty acids identified as important during embryogenesis, including higher total polyunsaturated fatty acids (PUFA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) when compared to the control and nanoplastic treatments. Whilst the short exposure time was ample for lipids from maternally digested algae to be incorporated into embryos, we discuss why the nanoplastic-fatty acid relationship may be more complex. Our study is the first to scope intergeneration effects of nanoplastic on Antarctic krill lipid and fatty acid reserves. From this, we suggest directions for future research including long term exposures, multi-stressor scenarios and exploring other critical energy reserves such as proteins.

Vertical flux of microplastic, a case study in the Southern Ocean, South Georgia

Estimated plastic debris floating at the ocean surface varies depending on modelling approaches, with some suggesting unaccounted sinks for marine plastic debris due to mismatches between plastic predicted to enter the ocean and that accounted for at the surface. A major knowledge gap relates to the vertical sinking of oceanic plastic. We used an array of floating sediment traps combined with optical microscopy and Raman spectroscopy to measure the microplastic flux between 50 and 150 m water depth over 24 h within a natural harbour of the sub-Antarctic island of South Georgia. This region is influenced by fishing, tourism, and research activity. We found a 69 % decrease in microplastic flux from 50 m (306 pieces/m²/day) to 150 m (94pieces/m²/day). Our study confirms the occurrence of a vertical flux of microplastic in the upper water column of the Southern Ocean, which may influence zooplankton microplastic consumption and the carbon cycle.

The FORCIS database: A global census of planktonic Foraminifera from ocean waters

Planktonic Foraminifera are unique paleo-environmental indicators through their excellent fossil record in ocean sediments. Their distribution and diversity are affected by different environmental factors including anthropogenically forced ocean and climate change. Until now, historical changes in their distribution have not been fully assessed at the global scale. Here we present the FORCIS (Foraminifera Response to Climatic Stress) database on foraminiferal species diversity and distribution in the global ocean from 1910 until 2018 including published and unpublished data. The FORCIS database includes data collected using plankton tows, continuous plankton recorder, sediment traps and plankton pump, and contains ~22,000, ~157,000, ~9,000, ~400 subsamples, respectively (one single plankton aliquot collected within a depth range, time interval, size fraction range, at a single location) from each category. Our database provides a perspective of the distribution patterns of planktonic Foraminifera in the global ocean on large spatial (regional to basin scale, and at the vertical scale), and temporal (seasonal to interdecadal) scales over the past century.

Organic or junk food? Microplastic contamination in Antarctic krill and salps

Microplastics (MP) have been reported in Southern Ocean (SO), where they are likely to encounter Antarctic zooplankton and enter pelagic food webs. Here we assess the presence of MP within Antarctic krill (Euphausia superba) and salps (Salpa thompsoni) and quantify their abundance and type by micro-Fourier transform infrared microscopy. MP were found in both species, with fibres being more abundant than fragments (krill: 56.25% and salps: 22.32% of the total MP). Polymer identification indicated MP originated from both local and distant sources. Our findings prove how in situ MP ingestion from these organisms is a real and ongoing process in the SO. MP amount was higher in krill (2.13 ± 0.26 MP ind^-1) than salps (1.38 ± 0.42 MP ind^-1), while MP size extracted from krill (130 ± 30 µm) was significantly lower than MP size from salps (330 ± 50 µm). We suggest that differences between abundance and size of MP ingested by these two species may be related to their food strategies, their ability to fragment MP as well as different human pressures within the collection areas of the study region. First comparative field-based evidence of MP in both krill and salps, two emblematic zooplankton species of the SO marine ecosystems, underlines that Antarctic marine ecosystems may be particularly sensitive to plastic pollution.

Pelagic calcium carbonate production and shallow dissolution in the North Pacific Ocean

Planktonic calcifying organisms play a key role in regulating ocean carbonate chemistry and atmospheric CO₂. Surprisingly, references to the absolute and relative contribution of these organisms to calcium carbonate production are lacking. Here we report quantification of pelagic calcium carbonate production in the North Pacific, providing new insights on the contribution of the three main planktonic calcifying groups. Our results show that coccolithophores dominate the living calcium carbonate (CaCO₃) standing stock, with coccolithophore calcite comprising ~90% of total CaCO₃ production, and pteropods and foraminifera playing a secondary role. We show that pelagic CaCO₃ production is higher than the sinking flux of CaCO₃ at 150 and 200 m at ocean stations ALOHA and PAPA, implying that a large portion of pelagic calcium carbonate is remineralised within the photic zone; this extensive shallow dissolution explains the apparent discrepancy between previous estimates of CaCO₃ production derived from satellite observations/biogeochemical modeling versus estimates from shallow sediment traps. We suggest future changes in the CaCO₃ cycle and its impact on atmospheric CO₂ will largely depend on how the poorly-understood processes that determine whether CaCO₃ is remineralised in the photic zone or exported to depth respond to anthropogenic warming and acidification.

The Ocean Plastic Incubator Chamber (OPIC) system to monitor in situ plastic degradation at sea

Marine plastic pollution is a global and pervasive environmental issue. Knowledge on plastic degradation in natural settings is still very limited due to current technological limitations, hampering our understanding of plastic fate (including its breakdown into micro- and nanoplastics) and of its risk for marine ecosystems. Here we present the proof of concept of the Ocean Plastic Incubator Chamber (OPIC), a novel equipment to follow plastic degradation in situ at sea over time. OPIC consists of a frame containing a motorised rotating stage with transparent tubes sub-assemblies where reference plastic materials are incubated and exposed to natural weathering conditions for defined time multi-years period. OPIC has been designed, tested and adapted for deployment with mooring line platforms in the open ocean with potential future application in remote environments at different depths (from shallow waters to deep sea environments). This incubator will allow us to measure different markers of plastic aging in situ in the ocean for the first time, providing new insights into the multiple and locally driven dynamics regulating plastic transformations and fate at sea.

Lifetime of autofluorescence: A novel method to determine murine skeletal muscle fiber types

This work describes a simple way to identify fiber types in living muscles by fluorescence lifetime imaging microscopy (FLIM). We quantified the mean values of lifetimes derived from a two-exponential fit (τ1 and τ2) in freshly dissected mouse FDB and soleus muscles. While τ1 values did not change between muscles, the distribution of τ2 shifted to higher values in FDB. To understand the origin of this difference, we obtained maps of autofluorescence lifetimes in cryosections of both muscles and paired them with immunofluorescence images of myosin heavy chain isoforms (MHC), which allow identification of fiber types. In soleus, τ2 was 3.1 ns for type I (SEM = 0.009, n = 49), 3.4 ns for type IIA (SEM = 0.01, n = 30), and 3.3 ns for type IIX (SEM = 0.01, n = 21). In FDB muscle, τ2 was 3.17 ns for type I (SEM = 0.04, n = 18), 3.5 ns for type IIA (SEM = 0.03, n = 27), and 3.62 ns for type IIX (SEM = 0.03, n = 22). From the distribution of measures, it follows that an FDB fiber with τ2 >3.3 ns is expected to be of type II, and of type I otherwise. This simple classification method has first- and second-class errors estimated at 0.06 and 0.27, respectively. Studies in progress aim at further elucidating the reasons for the different lifetimes, not just among fiber types but between fibers of the same type in the two muscles. Preliminary results point at differences in both the oxidation-reduction and protein-bound versus free states of flavins as causes for the observed divergence of fluorescence lifetimes. Lifetime maps of autofluorescence therefore constitute a tool to identify fiber type that, being practical, fast, and noninvasive, can be applied in living tissue without compromising other experimental interventions.

A record of microplastic in the marine nearshore waters of South Georgia

The polar plastics research community have recommended the spatial coverage of microplastic investigations in Antarctica and the Southern Ocean be increased. Presented here is a baseline estimate of microplastics in the nearshore waters of South Georgia, the first in situ study of the north-east coast of the island. Our results show that the microplastic concentration in seawater at twelve stations in proximity to King Edward Point Research Station ranged from 1.75 ± 5.17 MP/L (mean ± SD), approximately one order of magnitude higher than similar studies of sea surface waters south of the Polar Front. Levels of microplastics in freshwater (sampled from Gull Lake) and precipitation (collected adjacent to the research station) were 2.67 ± 3.05 MP/L, and 4.67 ± 3.21 MP/L respectively. There was no significant difference in the microplastic concentration between seawater sites, and no significant bilateral relationship between concentration and distance from the research station outlets. We report an average concentration of 1.66 ± 3.00 MP/L in wastewater collected from the research station but overall, the counts of microplastics were too low to attach any statistical significance to the similarity in the microplastic assemblages of seawater and wastewater, or assemblages retrieved from penguin species in the region in other studies. Using a calculation described in contemporary literature we estimate the number of microfibres potentially being released from ships and stations annually in the region but acknowledge that further samples are needed to support the figures generated. More extensive research into microplastic distribution, characteristics, and transport in the region is recommended to fully compute the level of risk which this pollutant represents to the ecosystem health of this remote region.

Status, Change, and Futures of Zooplankton in the Southern Ocean

In the Southern Ocean, several zooplankton taxonomic groups, euphausiids, copepods, salps and pteropods, are notable because of their biomass and abundance and their roles in maintaining food webs and ecosystem structure and function, including the provision of globally important ecosystem services. These groups are consumers of microbes, primary and secondary producers, and are prey for fishes, cephalopods, seabirds, and marine mammals. In providing the link between microbes, primary production, and higher trophic levels these taxa influence energy flows, biological production and biomass, biogeochemical cycles, carbon flux and food web interactions thereby modulating the structure and functioning of ecosystems. Additionally, Antarctic krill (Euphausia superba) and various fish species are harvested by international fisheries. Global and local drivers of change are expected to affect the dynamics of key zooplankton species, which may have potentially profound and wide-ranging implications for Southern Ocean ecosystems and the services they provide. Here we assess the current understanding of the dominant metazoan zooplankton within the Southern Ocean, including Antarctic krill and other key euphausiid, copepod, salp and pteropod species. We provide a systematic overview of observed and potential future responses of these taxa to a changing Southern Ocean and the functional relationships by which drivers may impact them. To support future ecosystem assessments and conservation and management strategies, we also identify priorities for Southern Ocean zooplankton research.

Stroke Mimics in the Acute Setting: Role of Multimodal CT Protocol

BACKGROUND AND PURPOSE

Ischemic stroke can be mimicked by nonischemic conditions. Due to emphasis on the rapid treatment of acute ischemic stroke, it is crucial to identify these conditions to avoid unnecessary therapies and potential complications. We investigated the performance of the multimodal CT protocol (unenhanced brain CT, CTA, and CTP) to discriminate stroke mimics from acute ischemic stroke.

MATERIALS AND METHODS

We retrospectively selected multimodal CT studies performed for clinical suspicion of acute ischemic stroke in our center in a 24-month period, including patients with at least 1 follow-up imaging study (brain CT or MR imaging). Hemorrhagic strokes were excluded. We measured the performance of multimodal CT, comparing the original diagnostic results with the final clinical diagnosis at discharge.

RESULTS

Among 401 patients, a stroke mimic condition was diagnosed in 89 (22%), including seizures (34.8%), migraine with aura attack (12.4%), conversion disorder (12.4%), infection (7.9%), brain tumor (7.9%), acute metabolic condition (6.7%), peripheral vertigo (5.6%), syncope (5.6%), transient global amnesia (3.4%), subdural hematoma (1.1%), cervical epidural hematoma (1.1%), and dural AVF (1.1%). Multimodal CT sensitivity, specificity, and accuracy were 24.7%, 99.7%, and 83%. Multimodal CT revealed peri-ictal changes in 13/31 seizures and diagnosed 7/7 brain tumors, 1/1 dural AVF, and 1/1 subdural hematoma. CT perfusion played a pivotal diagnostic role.

CONCLUSIONS

Multimodal CT demonstrated low sensitivity but high specificity in the diagnosis of stroke mimics in the acute setting. The high specificity of multimodal CT allows ruling out stroke and thereby avoiding unnecessary revascularization treatment in patients with diagnosis of a stroke mimic.

Under pressure: Nanoplastics as a further stressor for sub-Antarctic pteropods already tackling ocean acidification

In the Southern Ocean (SO), plastic debris has already been found in waters and sediments. Nanoplastics (<1 μm) are expected to be as pervasive as their larger counterparts, but more harmful to biological systems, being able to enter cells and provoke toxicity. In the SO, (nano)plastic pollution occurs concomitantly with other environmental threats such as ocean acidification (OA), but the potential cumulative impact of these two challenges on SO marine ecosystems is still overlooked. Here the single and combined effects of nanoplastics and OA on the sub-Antarctic pteropod Limacina retroversa are investigated under laboratory conditions, using two surface charged polystyrene nanoparticles (PS NPs) as a proxy for nanoplastics. Sub-Antarctic pteropods are threatened by OA due to the sensitivity of their shells to changes in seawater carbonate chemistry. Short-term exposure (48 h) to PS NPs compromised the ability of pteropods to counteract OA stress, resulting in a negative effect on their survival. Our results highlights the importance of addressing plastic pollution in the context of climate change to identify realistic critical thresholds of SO pteropods.

A Polar outlook: Potential interactions of micro- and nano-plastic with other anthropogenic stressors

Polar marine ecosystems may have higher sensitivity than other ecosystems to plastic pollution due to recurrent physical and biological features; presence of ice and high UV radiation, slow growth rates and weak genetic differentiation of resident biota, accumulation of persistent organic pollutants and heavy metals, and fast rates of warming and global ocean acidification. Here, we discuss potential sources of and exposure to micro- and nano-plastic in polar marine ecosystems and potential mixture effects of micro- and nano-plastic coupled with chemical and climate related stressors. We address the anthropogenic contaminants likely to be 'high risk' for interactions in Arctic and Antarctic waters for reasons such as accumulation under sea-ice, a known sink for plastic particulates. Consequently, we address the potential for localised plastic-chemical interactions and possible seasonal fluctuations in interactions associated with freeze-thaw events. The risks for keystone polar species are also considered, incorporating the behavioural and physiological traits of biota and addressing potential 'hotspot' areas. Finally, we discuss a possible direction for future research.

Nanoplastics affect moulting and faecal pellet sinking in Antarctic krill (Euphausia superba) juveniles

Plastic debris has been identified as a potential threat to Antarctic marine ecosystems, however, the impact of nanoplastics (<1 μm) is currently unexplored. Antarctic krill (Euphausia superba) is a keystone species of Southern Ocean pelagic ecosystems, which plays a central role in the Antarctic food webs and carbon (C) cycle. Krill has been shown to rapidly fragment microplastic beads through the digestive system, releasing nanoplastics with unknown toxicological effects. Here we exposed krill juveniles to carboxylic (COOH, anionic) and amino- (NH₂, cationic) polystyrene nanoparticles (PS NPs) and we investigated lethal and sub-lethal endpoints after 48 h. The analysis of PS NP suspensions in Antarctic sea water (SW) media showed that PS-COOH formed large agglomerates (1043 ± 121 nm), while PS-NH₂ kept their nominal size (56.8 ± 3 nm) during the exposure time. After 48 h, no mortality was found but increase in exuviae production (12.6 ± 1.3%) and reduced swimming activity were observed in juveniles exposed to PS-NH₂. The microbial community composition in SW supports the release of krill moults upon PS NP exposure and stimulates further research on the pivotal role of krill in shaping Southern Ocean bacterial assemblages. The presence of fluorescent signal in krill faecal pellets (FPs) confirmed the waterborne ingestion and egestion of PS-COOH at 48 h of exposure. Changes in FP structure and properties were also associated to the incorporation of PS NPs regardless of their surface charge. The effects of PS NPs on krill FP properties were compared to Control 0 h as a reference for full FPs (plastic vs food) and Control 48 h as a reference for more empty-like FPs (plastic vs lack of food). Exposure to PS NPs led to a FP sinking rate comparable to Control 48 h, but significantly lower than Control 0 h (58.40 ± 23.60 m/d and 51.23 ± 28.60 m/d for PS-COOH and PS-NH₂; 168.80 ± 74.58 m/d for Control 0 h). Considering the important role played by krill in the food web and C export in the Southern Ocean, the present study provides cues about the potential impact of nanoplastics on Antarctic pelagic ecosystems and their biogeochemical cycles.

Close encounters - microplastic availability to pelagic amphipods in sub-antarctic and antarctic surface waters

This study investigated the distribution of plastic debris from the Atlantic portion of the Sub-Antarctic to the Antarctic Peninsula. This region is home to some of the highest concentrations of zooplankton biomass but is also threatened by increasing shipping traffic from fishing and the growing tourism market. Samples were collected using a surface-towed neuston net during the Austral summer 2018, aboard the RRS James Clark Ross. Using Fourier Transform Infrared Spectrometry it was found that 45.6% of the plastic particles isolated from seawater samples were sampling contamination, originating predominantly from the ship. Of the remaining particles, both low density (polyethylene, polypropylene) and high-density (phenoxy and epoxy resins) polymers were found in the surface water suggesting both long-range and local sources of origin. Whilst we found that micro and mesoplastic concentrations in seawater were significantly low (0.013 ± 0.005n/m³) compared to global averages, they were higher along the Antarctic Peninsula than the open ocean (Sub-Antarctic) stations. The potential availability of micro and mesoplastics (MP) to pelagic amphipods was explored, using an observed encounter rate (OER) and a possible encounter rate (PER). The total OER (0.8%) was higher than the PER (0.15%), suggesting that even at low concentrations, microplastics are encountered, and potentially consumed, by amphipods. This study highlights the need to prioritise regions of high zooplankton abundance and to investigate both water and biota to build up a picture of plastic pollution and its potential interaction with the Antarctic Ecosystem.

Krill faecal pellets drive hidden pulses of particulate organic carbon in the marginal ice zone

The biological carbon pump drives a flux of particulate organic carbon (POC) through the ocean and affects atmospheric levels of carbon dioxide. Short term, episodic flux events are hard to capture with current observational techniques and may thus be underrepresented in POC flux estimates. We model the potential hidden flux of POC originating from Antarctic krill, whose swarming behaviour could result in a major conduit of carbon to depth through their rapid exploitation of phytoplankton blooms and bulk egestion of rapidly sinking faecal pellets (FPs). Our model results suggest a seasonal krill FP export flux of 0.039 GT C across the Southern Ocean marginal ice zone, corresponding to 17-61% (mean 35%) of current satellite-derived export estimates for this zone. The magnitude of our conservatively estimated flux highlights the important role of large, swarming macrozooplankton in POC export and, the need to incorporate such processes more mechanistically to improve model projections.

Condition of pteropod shells near a volcanic CO2 vent region

Natural gradients of pH in the ocean are useful analogues for studying the projected impacts of Ocean Acidification (OA) on marine ecosystems. Here we document the in situ impact of submarine CO₂ volcanic emissions (CO₂ vents) on live shelled-pteropods (planktonic gastropods) species Creseis conica in the Gulf of Naples (Tyrrhenian Sea, Mediterranean). Since the currents inside the Gulf will likely drive those pelagic calcifying organisms into and out of the CO₂ vent zones, we assume that pteropods will be occasionally exposed to the vents during their life cycle. Shell degradation and biomass were investigated in the stations located within and nearby the CO₂ vent emission in relation to the variability of sea water carbonate chemistry. A relative decrease in shell biomass (22%), increase in incidence of shell fractures (38%) and extent of dissolution were observed in Creseis conica collected in the Gulf of Naples compared to those from the Northern Tyrrhenian Sea (control stations). These results suggest that discontinuous but recurrent exposure to highly variable carbonate chemistry could consistently affect the characteristic of the pteropod shells.

Threatened species drive the strength of the carbonate pump in the northern Scotia Sea

The efficiency of deep-ocean CO₂ sequestration is regulated by the relative balance between inorganic and organic carbon export respectively acting through the biological carbon pump (BCP) and the carbonate counter pump (CCP). The composition and abundance of calcifying species in the prevailing oceanic plankton community plays a major role in driving the CCP. Here we assess the role of these calcifying organisms in regulating the strength of the CCP in a Southern Ocean region (northern Scotia Sea) known to be a major hotspot for the drawdown of atmospheric CO₂. We show that, when shelled pteropods dominate the calcifying community, the total annual reduction of CO₂ transferred to the deep ocean doubles (17%) compared to when other plankton calcifiers dominate (3–9%). Furthermore, predation enhances their contribution through the removal of organic soft tissue. Pteropods are threatened in polar regions by ocean warming and acidification. We determine that their potential decline would have major implications to the comparative strengths of the BCP and CCP.

The Scotia Sea, located in the Southern Ocean, is a major hotspot for the drawdown of atmospheric CO₂. Here, the authors show that the strength of the carbonate counter pump doubles when shelled pteropods dominate the plankton calcifier community, counteracting the amount of CO₂ transferred to the deep ocean.

Abnormal calcium signalling and the caffeine-halothane contracture test

Background

The variable clinical presentation of malignant hyperthermia (MH), a disorder of calcium signalling, hinders its diagnosis and management. Diagnosis relies on the caffeine–halothane contracture test, measuring contraction forces upon exposure of muscle to caffeine or halothane (F_C and F_H, respectively). Patients with above-threshold F_C or F_H are diagnosed as MH susceptible. Many patients test positive to halothane only (termed ‘HH’). Our objective was to determine the characteristics of these HH patients, including their clinical symptoms and features of cytosolic Ca²⁺ signalling related to excitation–contraction coupling in myotubes.

Methods

After institutional ethics committee approval, recruited patients undergoing contracture testing at Toronto's MH centre were assigned to three groups: HH, doubly positive (HS), and negative patients (HN). A clinical index was assembled from musculoskeletal symptoms and signs. An analogous calcium index summarised four measures in cultured myotubes: resting [Ca²⁺]_cytosol, frequency of spontaneous cytosolic Ca²⁺ events, Ca²⁺ waves, and cell-wide Ca²⁺ spikes after electrical stimulation.

Results

The highest values of both indexes were found in the HH group; the differences in calcium index between HH and the other groups were statistically significant. The principal component analysis confirmed the unique cell-level features of the HH group, and identified elevated resting [Ca²⁺]_cytosol and spontaneous event frequency as the defining HH characteristics.

Conclusions

These findings suggest that HH pathogenesis stems from excess Ca²⁺ leak through sarcoplasmic reticulum channels. This identifies HH as a separate diagnostic group and opens their condition to treatment based on understanding of pathophysiological mechanisms.

A Modified Two-Bun Method for Routine Urea Modeling: Clinical Validation in 120 Patients on a Free Diet

Recently, a modified algorithm of the Two-BUN method (MA2p), avoiding dialyzer clearance measurement, was presented for routine assessment of Kt/V and NPCR. To validate MA2p in patients on a free diet (FDP), we studied 120 stable dialysis FDP by measuring Kt/V and NPCR with both MA2p and a modified version of the standard Three-BUN method (MA3p), for the 3 weekly sessions. The NPCR values (g/kg/day), calculated by MA3p for the 3 interdialyses were: 1.286∓0.274, 1.256∓0.276, and 1.116∓0.230, respectively. The correlation coefficient (r) for averaged Kt/V values obtained by the two methods was 0.999 and the percent error (Error%) for MA2p vs. MA3p results ranged from -1.5 to +0.78%. The respective results for NPCR were: r=0.967, Error% range from -11.7 to +13.9%. In conclusion, MA2p can be safely used in patients on a free diet. The lowest NPCR values were observed during the long interdialysis.

Pteropods counter mechanical damage and dissolution through extensive shell repair

The dissolution of the delicate shells of sea butterflies, or pteropods, has epitomised discussions regarding ecosystem vulnerability to ocean acidification over the last decade. However, a recent demonstration that the organic coating of the shell, the periostracum, is effective in inhibiting dissolution suggests that pteropod shells may not be as susceptible to ocean acidification as previously thought. Here we use micro-CT technology to show how, despite losing the entire thickness of the original shell in localised areas, specimens of polar species Limacina helicina maintain shell integrity by thickening the inner shell wall. One specimen collected within Fram Strait with a history of mechanical and dissolution damage generated four times the thickness of the original shell in repair material. The ability of pteropods to repair and maintain their shells, despite progressive loss, demonstrates a further resilience of these organisms to ocean acidification but at a likely metabolic cost.

Sea butterflies, or pteropods, are often presented as being at threat from ocean acidification on account of their fragile shells being susceptible to dissolution. Here the authors show that pteropods are able to perform extensive repair to damaged shells, suggesting they may not be as vulnerable as previously thought.

Southern Ocean pteropods at risk from ocean warming and acidification

Early life stages of marine calcifiers are particularly vulnerable to climate change. In the Southern Ocean aragonite undersaturation events and areas of rapid warming already occur and are predicted to increase in extent. Here, we present the first study to successfully hatch the polar pteropod Limacina helicina antarctica and observe the potential impact of exposure to increased temperature and aragonite undersaturation resulting from ocean acidification (OA) on the early life stage survival and shell morphology. High larval mortality (up to 39%) was observed in individuals exposed to perturbed conditions. Warming and OA induced extensive shell malformation and dissolution, respectively, increasing shell fragility. Furthermore, shell growth decreased, with variation between treatments and exposure time. Our results demonstrate that short-term exposure through passing through hotspots of OA and warming poses a serious threat to pteropod recruitment and long-term population viability.

Pteropod eggs released at high pCO2 lack resilience to ocean acidification

The effects of ocean acidification (OA) on the early recruitment of pteropods in the Scotia Sea, was investigated considering the process of spawning, quality of the spawned eggs and their capacity to develop. Maternal OA stress was induced on female pteropods (Limacina helicina antarctica) through exposure to present day pCO₂ conditions and two potential future OA states (750 μatm and 1200 μatm). The eggs spawned from these females, both before and during their exposure to OA, were incubated themselves in this same range of conditions (embryonic OA stress). Maternal OA stress resulted in eggs with lower carbon content, while embryonic OA stress retarded development. The combination of maternal and embryonic OA stress reduced the percentage of eggs successfully reaching organogenesis by 80%. We propose that OA stress not only affects the somatic tissue of pteropods but also the functioning of their gonads. Corresponding in-situ sampling found that post-larval L. helicina antarctica concentrated around 600 m depth, which is deeper than previously assumed. A deeper distribution makes their exposure to waters undersaturated for aragonite more likely in the near future given that these waters are predicted to shoal from depth over the coming decades.

The eye-tracking computer device for communication in amyotrophic lateral sclerosis

OBJECTIVE

To explore the effectiveness of communication and the variables affecting the eye-tracking computer system (ETCS) utilization in patients with late-stage amyotrophic lateral sclerosis (ALS).

METHODS

We performed a telephone survey on 30 patients with advanced non-demented ALS that were provisioned an ECTS device. Median age at interview was 55 years (IQR = 48-62), with a relatively high education (13 years, IQR = 8-13). A one-off interview was made and answers were later provided with the help of the caregiver. The interview included items about demographic and clinical variables affecting the daily ETCS utilization.

RESULTS

The median time of ETCS device possession was 15 months (IQR = 9-20). The actual daily utilization was 300 min (IQR = 100-720), mainly for the communication with relatives/caregiver, internet surfing, e-mailing, and social networking. 23.3% of patients with ALS (n = 7) had a low daily ETCS utilization; most reported causes were eye-gaze tiredness and oculomotor dysfunction.

CONCLUSIONS

Eye-tracking computer system is a valuable device for AAC in patients with ALS, and it can be operated with a good performance. The development of oculomotor impairment may limit its functional use.

Rituximab for treatment of inhibitors in haemophilia A. A Phase II study

The development of antibodies against infused factor VIII (FVIII) in patients with haemophilia A is a serious complication leading to poorly controlled bleeding and increased morbidity. No treatment has been proven to reduce high titre antibodies in patients who fail immune tolerance induction or are not candidates for it. The Rituximab for the Treatment of Inhibitors in Congenital Hemophilia A (RICH) study was a phase II trial to assess whether rituximab can reduce anamnestic FVIII antibody (inhibitor) titres. Male subjects with severe congenital haemophilia A and an inhibitor titre ≥5 Bethesda Units/ml (BU) following a FVIII challenge infusion received rituximab 375 mg/m² weekly for weeks 1 through 4. Post-rituximab inhibitor titres were measured monthly from week 6 through week 22 to assess treatment response. Of 16 subjects who received at least one dose of rituximab, three (18.8%) met the criteria for a major response, defined as a fall in inhibitor titre to <5 BU, persisting after FVIII re-challenge. One subject had a minor response, defined as a fall in inhibitor titre to <5 BU, increasing to 5-10 BU after FVIII re-challenge, but <50% of the original peak inhibitor titre. Rituximab is useful in lowering inhibitor levels in patients, but its effect as a solo treatment strategy is modest. Future studies are indicated to determine the role of rituximab as an adjunctive therapy in immune tolerisation strategies.

Bone morphogenetic protein-2 may represent the molecular link between oxidative stress and vascular stiffness in chronic kidney disease

Oxidative stress and vascular calcifications are emergent risk factors for the accelerated atherosclerosis process featuring chronic kidney disease (CKD). Vascular calcification is an active process similar to bone modelling, where BMP-2 may play a pathogenic role. Aim of our study was to investigate the link between oxidative stress, BMP-2 protein expression and vascular disease in CKD. We enrolled 85 CKD patients (K-DOQI stage II or higher) and 41 healthy individuals. 8-Oxo-7,8-dihydro-2'-deoxyguanosine (8-OHdG) was used as a marker of oxidative stress. Brachial-ankle pulse wave velocity (baPWV) was used as a measure of arterial stiffness. BMP-2 serum levels were significantly higher in CKD patients than in controls (p<0.0001). Serum 8-OHdG levels were significantly higher in CKD patients compared to controls (p<0.05). BMP-2 serum levels were inversely associated with eGFR (r=-0.3; p=0.01) and directly correlated with 8-OHdG serum concentrations (r=-0.3; p=0.03). Arterial stiffness was inversely correlated with eGFR (r=-0.4; p=0.001) and directly correlated with BMP-2 (r=0.3; p=0.03), 8-OHdG (r=0.4, p=0.02) and phosphorus serum levels (r=0.3; p=0.007). In a multiple regression model, phosphorus and BMP-2 were independently correlated with baPWV. In vitro exposure to H(2)O(2) induced a time and dose-dependent increase in BMP-2 expression in an immortalized endothelial cell line. Moreover, H(2)O(2) pre-incubation of cultured vascular smooth muscle cell enhanced the BMP-2-induced up-regulation of ALPL, an osteoblastic phenotype marker. Our data suggest that in CKD BMP-2 may represent the molecular link between oxidative stress and arterial stiffness due to vascular calcification.

[The usefulness of Cochrane systematic reviews in nephrology]

Systematic reviews (SRs) of the literature are clinical research studies carried out according to rigorous methodological criteria. They are aimed at searching, critically appraising and summarizing all studies with similar characteristics that address the same research question. The Cochrane Collaboration is the main institution that coordinates the production of SRs. The Cochrane Renal Group is one of the 50 research groups of the Cochrane Collaboration and is in charge of SRs in nephrology. This group compiled the Renal Health Library, an annually updated collection of SRs (Cochrane and not) and randomized controlled trials in nephrology, dialysis and renal transplantation. We searched the Renal Health Library to identify SRs useful to answer clinical questions in patients with renal disease and/or following kidney transplant. The SRs identified were summarized and the results were expressed as relative risk, weighted mean difference, standardized mean difference, and 95% confidence intervals. Since the number of randomized controlled trials is quite large and SRs are a reliable summary of the scientific evidence, their distribution is of paramount importance. Here we show several clinical cases where related SRs in the Renal Health Library provide useful guidance for treatment.

[Health-related quality of life in patients with chronic kidney disease]

Assessment of quality of life in patients with different degrees of chronic kidney disease is an important issue because of its impact on clinical decisions and financial resource management in the health-care system. The aim of this study was to assess whether a generic instrument like the SF-36 questionnaire is able to discriminate three different populations of patients with different degrees of renal disease (pre-ESRD, ESRD, TxR). Five hundred sixty-three patients from 12 Italian nephrology units completed the SF-36 scales by themselves. The results from these samples were compared with those from the general population. Univariate analysis and multivariate regression were used. The generic SF-36 questionnaire proved to be a powerful instrument to discriminate populations with different degrees of chronic renal failure. The quality of life of patients on dialysis is significantly worse than that of the normal population and other patients with less severe renal function impairment.

[Evidence-based guidelines and nephrological clinical practice: the GRADE system for rating of evidence]

It has become widely accepted that decision-making should be based on the best available evidence. The preparation of evidence-based guidelines in the interest of improving long-term outcomes has been a challenging task for many societies. Although nephrology is a relatively young medical discipline and therefore presumably well-disposed towards evidence-based decision making, many problems exist and evidence-based approaches to guidelines have also been widely criticized. One key issue has been the availability of only few and suboptimal randomized trials in this discipline. Considerable variation in the grading systems used to assess existing evidence in nephrology guidelines highlights the need for a better tool. Tools that rigidly assess existing evidence need to also explore the applicability to current practice. The Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) system, developed and implemented in 2004 by the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines panel, is the most advanced tool in this direction.

[Patient satisfaction in hemodialysis: a pilot cross-sectional analysis and a review]

BACKGROUND

Assessment of patient satisfaction is not performed routinely in many healthcare institutions. In this review, we discuss methodological aspects of assessment of patient satisfaction in hemodialysis. We also present a pilot study conducted in the Gambro Healthcare Italy dialysis clinics network.

METHODS

Patient satisfaction was assessed in a network of hemodialysis units by using an internally validated Italian translation of the Choices for Healthy Outcomes in Caring for ESRD (CHOICE) questionnaire. A cross-sectional analytic study design was used and data analysed with univariate and multivariate hierarchical logistic regression to explore correlates of the risk of being unsatisfied with dialysis treatment. Covariates which were considered include a series of over 20 clinical, demographic, organizational and structural aspects. In addition, unexplained inter-centre residual variability due to 'case-mix' was explored and plotted.

RESULTS

Seventeen dialysis units participated in this cross-sectional analysis and 758/1001 (75.7%) provided answers to the questionnaires. There was a statistically significant association on multivariate hierarchical analysis between the risk of being unsatisfied with dialysis treatment and interdialysis body weight gain (unit of increase: 1 kg, p=0.004). On the contrary, the risk of unsatisfaction with dialysis treatment was significantly lower in patients with higher dry weight (unit of increase: 1 kg, p=0.002). Our multivariate hierarchical analysis identified some residual variability between dialysis units (n=6 outliers) which may not be explained by any of over 20 potential confounding covariates which were explored.

CONCLUSIONS

Assessment of ''customer satisfaction'' is standard practice in private for profit product companies in general but needs to be increasingly recognized as a standard in both public and private providers of healthcare services. Social research methods, which are used for this type of analysis, need to be fine tuned and actively implemented in order to better understand how we may influence the quality of service we provide to our patients and the level at which they rate it.

[Antihypertensive agents for the prevention of chronic kidney disease progression: guideline from the Italian Society of Nephrology]

BACKGROUND

The current 3rd edition of the Italian Society of Nephrology guidelines has been drawn up to summarize evidence of key intervention issues on the basis of systematic reviews (SR) of randomized trials (RCT) or RCT data only. In the present guideline, evidence of the use of antihypertensive agents to prevent chronic kidney disease progression (CKD) is presented.

METHODS

SR of RCT and RCT on antihypertensive agents used to prevent CKD progression were identified referring to a Cochrane Library and Renal Health Library search (2005 update).

RESULTS

Seven SR and 26 further RCT were found addressing this intervention issue. Methodological quality of available RCT was suboptimal according to current methodological standards. Angiotensin converting enzyme inhibitors (ACE-I) are associated with significant effects on the prevention of CKD progression in non-diabetic and diabetic patients (evidence from SR). Angiotensin receptor blockers (ARB) are as effective as ACE-I in delaying CKD progression in diabetic and non-diabetic patients (evidence from SR). Dihydropyridine and non-dihydropyridine calcium antagonists have not been found to significantly affect proteinuria and CKD progression (evidence from SR). Combination therapy with ACE-I and ARB is associated with a significant reduction in the risk of CKD progression and proteinuria, but long term data are only available in patients with non-diabetic nephropathy (evidence from RCT).

CONCLUSION

Available evidence of renal protection suggest that ACE-I and ARB should be recommended in CKD patients (diabetic and non-diabetic nephropathy). Further studies are necessary to test the effectiveness of other antihypertensive agents or combination therapy.

[Corticosteroid treatment for a first episode of steroid-sensitive nephrotic syndrome (SSNS) in children: guideline from the Italian Society of Nephrology]

BACKGROUND

The current 3rd edition of the Italian Society of Nephrology guidelines has been drawn up to summarize evidence of key intervention issues on the basis of systematic reviews (SR) of randomized trials (RCT) or RCT data only. In the present guideline, evidence of the use of corticosteroid treatment for a first episode of steroid-sensitive nephrotic syndrome (SSNS) in children is presented.

METHODS

SR of RCT and RCT on SSNS therapeutic interventions were identified referring to a Cochrane Library and Renal Health Library search (2005 update). Results. One SR including 15 RCT was available on this topic. Methodological quality of available RCT was suboptimal according to current methodological standards.

RESULTS

In children with a first episode of SSNS, corticosteroids administered for 3 months or more compared with 2 months' administration are associated with a significant reduction in the risk of relapse at 6, 12 and 24 months, and in frequent relapsing rates, even though complications did not seem significantly increased (psychological, ocular, gastrointestinal disorders, hypertension, growth delay, Cushingoid syndrome, infection and osteoporosis) (evidence from SR). 6-month compared to 3-month treatment regimens are associated with a significant reduction in the risk of relapse at 12-24 months (evidence from SR). Increasing steroids cumulative doses are associated with increasing improvements in the risk of relapse (evidence from RCT). The risk of relapse at 12-24 months correlates inversely with duration of treatment (evidence from SR).

CONCLUSION

In SSNS children, current available evidence supports the hypothesis that primary intervention should be a high dose of corticosteroids administered for 3 months or more. Further studies are necessary to test this hypothesis in adult patients.

[Treating lupus nephritis: guideline from the Italian Society of Nephrology]

BACKGROUND

The current 3rd edition of the Italian Society of Nephrology guidelines has been drawn up to summarize evidence of key intervention issues on the basis of systematic reviews (SR) of randomized trials (RCT) or RCT data only. In the present guideline, evidence of lupus nephritis (LN) treatment is presented.

METHODS

SR of RCT and RCT on different therapeutic options for LN were identified referring to a Cochrane Library and Renal Health Library search (2005 update).

RESULTS

One SR of 25 RCT and 6 further RCT were available to address this issue. Methodological quality of available RCT was suboptimal according to current methodological standards. In LN patients, combining cyclophosphamide (CyA) and steroids as induction therapy results in a reduced risk of serum creatinine doubling compared to steroids alone, although there is no evidence of significant survival advantage and risk of ovarian failure was demonstrated (evidence from SR). The association of azathioprine (Aza) and steroids significantly reduces the risk of all-cause mortality compared to steroids alone (evidence from SR). No significant survival advantages from the association of plasma exchange and CyA or Aza are proven (evidence from SR). No significant differences on renal and survival endpoints are demonstrated with different dosing of CyA (evidence from RCT).

CONCLUSION

In LN patients available evidence supports the hypothesis that immunosuppressive agents reduce the risk of all-cause mortality and the risk of progressive renal disease. Further studies are necessary to test new immunosuppressive agents such as mycophenolate mofetil in severe LN patients.

[Therapeutic strategies for membranous nephropathy: guideline from the Italian Society of Nephrology]

BACKGROUND

The current 3rd edition of the Italian Society of Nephrology guidelines has been drawn up to summarize evidence of key intervention issues on the basis of systematic reviews (SR) of randomized trials (RCT) or RCT data only. In the present guideline, evidence of interventions for idiopathic membranous nephropathy (MN) is presented.

METHODS

SR of RCT and RCT on interventions for MN were identified referring to a Cochrane Library and Renal Health Library search (2005 update).

RESULTS

Three SR and 18 RCT were available to address this issue. Methodological quality of available RCT was suboptimal according to current methodological standards. In patients with MN, nephrotic syndrome and normal renal function, methylprednisolone and chlorambucil or cyclophosphamide for 6 months alternately increase the probability of nephritic syndrome remission (evidence from SR) and long-term renal protection (evidence from RCT). Other drugs (ACTH and cyclosporine) are associated with nephrotic syndrome remission, but there is no evidence of significant effects on renal function (evidence from RCT). In patients with impaired renal function, association of corticosteroids and cytotoxic agents is proven to cause a short-term delay of renal damage progression, even though benefits are counterbalanced by complications (evidence from RCT).

CONCLUSION

In patients with MN, nephrotic syndrome and normal renal function, current available evidence supports the hypothesis that primary intervention should be the association of corticosteroids and cytotoxic agents. Secondary therapeutic choices include ACTH and cyclosporine. Further studies are necessary to test new immunosuppressive agents such as mycophenolate mofetil.

[Immunosuppressive and non-immunosuppressive agents for patients with IgA nephropathy: guideline from the Italian Society of Nephrology]

BACKGROUND

The current 3rd edition of the Italian Society of Nephrology guidelines has been drawn up to summarize evidence of key intervention issues on the basis of systematic reviews (SR) of randomized trials (RCT) or RCT data only. In the present guideline, evidence of the use of immunosuppressive and non-immunosuppressive treatments in IgA nephropathy (IgAN) is presented.

METHODS

SR of RCT and RCT on treatment in patients with IgAN were identified referring to a Cochrane Library and Renal Health Library search (2005 update). Quality of SR and RCT was assessed according to current methodological standards.

RESULTS

Two SR of RCT (13 and 3 RCT, respectively), and 18 further RCT were available to address this issue. Methodological quality of available trials was suboptimal. In patients with IgAN and normal or mildly impaired renal function, steroids significantly delay the progression to end stage kidney disease (evidence from SR) and improve proteinuria. Associating steroids and cytotoxic agents (cyclophosphamide followed by oral azathioprine) proves effective in patients with rapidly progressive renal disease (evidence from RCT). Angiotensin converting enzyme inhibitors and angiotensin II receptor blockers significantly improve proteinuria (evidence from RCT), but there are no conclusive data on efficacy on hard patient level endpoints. There are no conclusive data available on the use of a therapy combining these agents.

CONCLUSION

In IgAN patients current evidence supports the hypothesis that immunosuppressive agents delay the progression to end stage renal disease. Further studies are necessary to test this hypothesis in selected patient populations.

[The Italian Society of Nephrology Guidelines (3rd Edition): principles and methods]

Scientific Societies at both a local and international level are making big effort to prepare their clinical practice guidelines. The Italian Society of Nephrology has already published in two previous editions a series of guidelines relating to various aspects of management and diagnosis of different renal diseases. In this review we present the criteria of the 3(rd) edition of the Italian Society of Nephrology guidelines. This 3(rd) edition of guidelines will be based on the availability of scientific evidence in different areas of nephrology, dialysis and transplantation. Ten key intervention questions have been identified, based on the availability of systematic reviews of randomized trials or individual randomized address them. Systematic reviews and randomized trials are the optimal study design to address intervention questions. These have been summarized based upon rigid methodological criteria and strictly reflect the evidence basis. The different phases of development and publication of the 3(rd) edition of the Italian Society of Nephrology guidelines are presented.

[Update of the Italian Society of Nephrology Project No. 1 of the 2004-2006 SIN programme]

In the last few years the Italian Society of Nephrology has addressed many technical-scientific and management aspects to better patient satisfaction. Project No. 1 of the 2004-2006 programme on 'Quality and Accreditation of National Renal Units' focuses on four essential points. The first is the questionnaire mailed to all the Presidents and Regional Delegates on the relationship between Nephrology units, Local Government Health-System and the Regional Healthcare Agency. The results evidence that the 'political' decision-making power of nephrologists decreases in the absence of a national strategy. The second point, in collaboration with the National Census Group, includes the quality analysis and the standardization of resources (human and structural) and management of the Renal Units. The third point is based on 'Educational Courses for Quality and Accreditation' held in Rome (3-5 October 2005: L'Accreditamento all'Eccellenza dell'Unita' Operativa di Nefrologia, Dialisi e Trapianto; 17-19 October 2005: Il Manuale di Accreditamento della Specialità di Nefrologia). The courses aim at training members responsible for each region to hold courses in their specific region to create a network including each single Renal Unit to create an acceptable homogenous language on the models of analysis and on the correct use of 'The Guide for Excellence Accreditation'. The fourth point concerns both the on-line Guide for Excellence Accreditation and 'Peer Review Accreditation' and the NEQUASY (Nephrology Quality System) project. The manual must be 'user friendly' allowing each Centre to self-evaluate using national and regional standards.

Considerations in the evaluation of haemophilia patients for short-term prophylactic therapy: a paediatric and adult case study

The long-term prophylactic administration of clotting factor concentrate in patients with haemophilia reduces bleeding events, slows joint deterioration, and improves quality of life. Prophylaxis can also be effective when used short-term to prevent or reduce bleeding associated with trauma, surgery, and athletic activities. While clinical trials are needed to establish the optimal length of prophylaxis following injury, several weeks and possibly months of treatment may be needed. Discontinuing therapy prematurely can result in rebleeding in the injured area.

[Evidence-based guidelines in nephrology]

INTRODUCTION

The preparation of evidence-based guidelines by the Nephrology Societies is fundamental to improve long-term outcomes of patients with chronic kidney diseases. However, this is a complex process and requires the interaction of clinicians and experts in epidemiology methods, and researchers and research enterprises.

METHODS

In this review, we present the potential structure of a body for the coordination and development of evidence-based guidelines in a nephrology society and we address the major problems that can arise in this process describing strategies that could be used to overcome them.

RESULTS

The development of evidence-based nephrology guidelines requires a structure; this should consist of a coordinating center and a number of working groups. The working groups is to identify specific research questions and to develop and synthetize the evidence in answer to the questions proposed. This shall be done in collaboration with the coordinating center. Draft guidelines produced by this process should be peer reviewed, disseminated and implemented.

CONCLUSIONS

The development of evidence-based nephrology guidelines is a challenge for individual nephrology societies. These guidelines are different from typical research publications in that their success does not lie in the final publication, but in the actual dissemination and implementation, which is in the improvement of patient outcomes and its measurement.

[Quality guide in nephrology and dialysis]

The Quality Guide, a strategic tool for any nephrologist wishing to initiate a quality policy in his own renal unit, describes to the organisation of total quality management. This article gives a short description of a Quality Guide in Nephrology and Dialysis. According to ISO 9004:2000 Norms, the Quality Guide can be subdivided into four sections: Managerial Accountability, Resource Management; Implementation of Services; Analysis, Evaluation and Continuous Quality Improvement. The quality cycle begins by identifying the customers, who added to the resources constitute the input that will be transformed by the service into output (results). By measuring customer satisfaction the results will be evaluated and analyzed to allow continuous improvement of the service. In conclusion, the drafting of the Guide by all staff members involved has a twofold value: it organizes the quality management within the renal unit and certifies the quality level guaranteed to the customer.

[Search strategies for nephrology knowledge and evidence]

The informatic techniques for searching biomedical literature have been one of the fundamental advantages of the era of information explosion. In this review, we focus on some methodologies for searching biomedical literature with particular focus on nephrology and describe the use of PubMed and the techniques for understanding and using the Medical Subject Heading (MeSH) to search Medline and other databases. Search strategies take advantages of simple search engines which generate informatic algorithms to find relevant articles; alternatively, a set of rules is to be known and represents a more powerful means for identification of selected publications. The latter technique is more useful for researchers seeking relevant information in the literature to prepare systematic reviews. Informatic techniques for searching biomedical literature have represented a fundamental advantage in science. Additional advantage will derive from the use of structured formats in research reporting, with better and quicker readability of retrieved published information, and from the effort of researchers in synthetizing the available published literature.