Membrane rafts are transient and unstable membrane microdomains that are enriched in sphingolipids, cholesterol, and specific proteins. They are involved in intracellular trafficking, signal ...transduction, pathogen entry, and attachment of various ligands. Increasing experimental evidence on the crucial biological roles of membrane rafts under normal and pathological conditions require new techniques for their structural and functional characterization. In particular, fluorescence-labeled cytolytic proteins that interact specifically with molecules enriched in rafts are of increasing interest. Cholera toxin subunit B interacts specifically with raft-residing ganglioside G(M1), and it has long been the lipid probe of choice for membrane rafts. Recently, four new pore-forming toxins have been proposed as selective raft markers: (i) equinatoxin II, a cytolysin from the sea anemone Actinia equina, which specifically recognizes free and membrane-embedded sphingomyelin; (ii) a truncated non-toxic mutant of a cytolytic protein, lysenin, from the earthworm Eisenia foetida, which specifically recognizes sphingomyelin-enriched membrane domains; (iii) a non-toxic derivative of the cholesterol-dependent cytolysin perfringolysin O, from the bacterium Clostridium perfringens, which selectively binds to membrane domains enriched in cholesterol; and (iv) ostreolysin, from the mushroom Pleurotus ostreatus, which does not bind to a single raft-enriched lipid component, but requires a specific combination of two of the most important raft-residing lipids: sphingomyelin and cholesterol. Nontoxic, raft-binding derivatives of cytolytic proteins have already been successfully used to explore both the structure and function of membrane rafts, and of raft-associated molecules. Here, we review these four new derivatives of pore-forming toxins as new putative markers of these membrane microdomains.
1. Nutrient additions often result in species dominance/compositional changes in wetland ecosystems, but the impact of nutrients may be constrained by different salinity levels. Wetlands of northern ...Belize, distributed along a salinity gradient, are strongly phosphorus-limited and dominated largely by three species of emergent macrophytes: Eleocharis cellulosa Torr., Cladium jamaicense Crantz and Typha domingensis Pers. 2. We conducted a mesocosm experiment to assess changes in growth characteristics biomass allocation, plant height, relative growth rate (RGR), rhizome length and nutrient uptake of these three species in response to simultaneous changes in levels of nutrients (nitrogen and phosphorus) and salinity. 3. The growth characteristics of Typha and Eleocharis responded positively to N and especially P addition, whereas the growth response of Cladium was largely insignificant. The RGR of Typha increased under P addition, while RGR of Eleocharis increased with N and decreased with salinity addition. Nutrient addition increased the rhizome number of both Typha and Eleocharis. However, plasticity in rhizome length was observed only in Typha, which showed increased rhizome length at medium and high P. 4. Salinity decreased plant height and shoot and root biomass of Cladium and Eleocharis, while in Typha it reduced only height. Rhizome number and length were decreased only in Eleocharis. 5. Both medium and high P additions increased tissue P content in all three species, but Eleocharis accumulated significantly more P than Cladium and Typha. Nitrogen additions increased tissue N content in Cladium and Eleocharis, but not in Typha. 6. Cladium exhibited strong morphological constraint and behaved as a stress-tolerator that was well adapted to low nutrients. Typha- characterized by its plastic, opportunistic guerrilla growth strategy, fast and efficient space occupancy, and rather wasteful nutrient management - behaved as a typical competitor. Eleocharis responded rapidly to nutrients but displayed limited rhizome plasticity, and its growth was affected at higher salinity. 7. According to recorded traits, we hypothesize that P input into wetlands will result in expansion of Typha, leading to competitive exclusion of both co-occurring species. The only conditions allowing coexistence of all three species are those limiting vertical and horizontal growth of Typha: low P and higher salinity. To ensure the stability of Belizean wetlands, the maintenance of oligotrophic status is therefore crucial.
Purpose of Review
The use of renal tumor biopsy (RTB) for small renal masses (SRMs) in daily practice, although safe and accurate, is unusual. Considering the large number of benign tumors in ...patients with renal masses < 4 cm, some patients with benign tumors are directly referred for surgery instead. This study aimed to report the diagnostic rates of RTB, determine the concordance with surgical pathology, and assess the number of procedures that could have been avoided. We retrospectively studied 255 patients who underwent RTB at our institution in 2010–2019. Of them, 73 were excluded from the analysis (exclusion criteria: > 4 cm, cystic lesion, missing data). The remaining 182 with undetermined SRMs ≤ 4 cm underwent RTB under computed tomography guidance.
Recent Findings
Biopsies were diagnostic in 154/182 (84.6%) cases. Of the non-diagnostic biopsies, 11 were diagnostic when repeated. When RTB was performed of all undetermined SRMs, active treatment (surgery or cryotherapy) was avoided in 50/182 patients (27.5%) because of a benign diagnosis, while 9/182 patients (4.9%) underwent surveillance after a shared multidisciplinary decision. The overall diagnostic rate was 90.6%. All adverse events (approximately 4%) were Clavien-Dindo grade I and did not require active treatment. RTB histology results and nuclear grade were highly concordant with the final pathology (96% and 86.6%, respectively). On univariate logistic regression analysis, male sex was the only contributing factor of diagnostic biopsy.
Summary
RTB of SRMs should be performed more frequently as part of a multidisciplinary decision-making process since it avoided unnecessary surgical treatment in 1 of 3 patients in our institution.
Purpose of Review
To summarize current options available for robot-assisted partial nephrectomy
Recent Findings
Partial nephrectomy (PN) is a standard treatment option for management of cT1 renal ...masses. It may be carried out by multiple approaches. Robot-assisted (RA) PN is one such option. The goal of treatment is both correct oncological (negative surgical margins) and functional (preservation of sufficient amount of renal parenchyma of the operated kidney) outcome. Appropriate outcomes depend on multiple factors. There are many, but among others tumor characteristics (size, location, i.e., tumor complexity), patient baseline renal function, patient comorbidities, and performance status etc. Based on all these, the surgeon adapts the intervention for each mass/patient by preoperative planning, absence/use/duration of warm or cold ischemia, perioperative imaging, resection technique adapted to tumor location and depth of invasion, use of hemostatics, type and degree of renal parenchymal closure and others details. Nephroprotective agents have not shown efficacy so far. It should not be forgotten that surgeon’s experience plays a key role in the achievement of good results.
Summary
Although multiple factors have a role in the RA partial nephrectomy, surgeon experience and adaptation of technique of intervention have the crucial role in the achievement of both functional and oncological results.
We suggest a new technique for estimating the relative drawdown of CO
2
concentration (
c
) in the intercellular air space (IAS) across hypostomatous leaves (expressed as the ratio
c
d
/
c
b
, where ...the indexes d and b denote the adaxial and abaxial edges, respectively, of IAS), based on the carbon isotope composition (δ
13
C) of leaf cuticular membranes (CMs), cuticular waxes (WXs) or epicuticular waxes (EWXs) isolated from opposite leaf sides. The relative drawdown in the intracellular liquid phase (i.e., the ratio
c
c
/
c
bd
, where
c
c
and
c
bd
stand for mean CO
2
concentrations in chloroplasts and in the IAS), the fraction of intercellular resistance in the total mesophyll resistance (
r
IAS
/
r
m
), leaf thickness, and leaf mass per area (LMA) were also assessed. We show in a conceptual model that the upper (adaxial) side of a hypostomatous leaf should be enriched in
13
C compared to the lower (abaxial) side. CM, WX, and/or EWX isolated from 40 hypostomatous C
3
species were
13
C depleted relative to bulk leaf tissue by 2.01–2.85‰. The difference in δ
13
C between the abaxial and adaxial leaf sides (δ
13
C
AB
−
13
C
AD
,
Δ
b–d
), ranged from − 2.22 to + 0.71‰ (− 0.09 ± 0.54‰, mean ± SD) in CM and from − 7.95 to 0.89‰ (− 1.17 ± 1.40‰) in WX. In contrast, two tested amphistomatous species showed no significant
Δ
b–d
difference in WX.
Δ
b–d
correlated negatively with LMA and leaf thickness of hypostomatous leaves, which indicates that the mesophyll air space imposes a non-negligible resistance to CO
2
diffusion. δ
13
C of EWX and 30-C aldehyde in WX reveal a stronger CO
2
drawdown than bulk WX or CM. Mean values of
c
d
/
c
b
and
c
c
/
c
bd
were 0.90 ± 0.12 and 0.66 ± 0.11, respectively, across 14 investigated species in which wax was isolated and analyzed. The diffusion resistance of IAS contributed 20 ± 14% to total mesophyll resistance and reflects species-specific and environmentally-induced differences in leaf functional anatomy.
To assess surgical outcomes and failure factors in the management of rectourethral fistulas treated surgically with the modified York Mason technique based on our center's 25 years of experience.
...From 1997 to 2021, in a single center study, a total of 35 consecutive patients, underwent rectourethral fistula cure, using the modified York Mason technique. Preoperative patient data, surgical outcomes and failure factors were assessed.
Of the 35 patients, 28 were successfully managed without the need of further intervention (80%). Median age was 67 years (IQR 62-72) and median follow-up time was 71 months (IQR 30-123). There was no significant difference between the patients that had recurrence or not after the first York Mason.
The modified York Mason technique offers a high success rate for the cure of iatrogenic rectourethral fistulas. No predictive factor of failure, after a first cure of recto-uretral fistula by modified York-Mason technique was reported.
3.
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