Anatomy of the superficial peroneal nerve: Can we predict nerve location and minimize iatrogenic lesion?

OBJECTIVE OF THE STUDY: Knowledge of anatomical variations of the superficial peroneal nerve (SPN) may minimize iatrogenic insults. The aim of the investigation was to perform an anatomical description of the SPN. MATERIALS AND METHODS: Twenty-three embalmed cadaver lower limbs were dissected. RESULTS: The SPN emerged from the crural fascia about 6.3±7.7mm anteromedial to the anterior border of the fibula and 26.8±12.6mm anteromedial and 113.6±43.9mm superior to the tip of the lateral malleolus. The median point of bifurcation into two terminal branches was 13.0mm anteromedial to the anterior border of the fibula and 34.9±14.7mm anteromedial and 81.0±69.0mm superior to the tip of the lateral malleolus. The SPN was found between 5.76% and 7.70% of the individual's height proximal to the tip of the lateral malleolus, with an unpredictable branching pattern over the intermalleolar line. CONCLUSION: A lateral ankle approach over the posterolateral surface of the fibula (posterior to the tip of the lateral malleolus) minimizes the risk of iatrogenic nerve lesion.

Seasonal proteome variation in intertidal shrimps under a natural setting: Connecting molecular networks with environmental fluctuations.

The ability of intertidal organisms to maintain their performance via molecular and physiological adjustments under low tide, seasonal fluctuations and extreme events ultimately determines population viability. Analyzing this capacity in the wild is extremely relevant since intertidal communities are under increased climate variability owing to global changes. We addressed the seasonal proteome signatures of a key intertidal species, the shrimp Palaemon elegans, in a natural setting. Shrimps were collected during spring and summer seasons at low tides and were euthanized in situ. Environmental variability was also assessed using hand-held devices and data loggers. Muscle samples were taken for 2D gel electrophoresis and protein identification through mass spectrometry. Proteome data revealed that 55 proteins (10.6% of the proteome) significantly changed between spring and summer collected shrimps, 24 of which were identified. These proteins were mostly involved in cytoskeleton remodelling, energy metabolism and transcription regulation. Overall, shrimps modulate gene expression leading to metabolic and structural adjustments related to seasonal differences in the wild (i.e. abiotic variation and possibly intrinsic cycles of reproduction and growth). This potentially promotes performance and fitness as suggested by the higher condition index in summer-collected shrimps. However, inter-individual variation (% coefficient of variation) in protein levels was quite low (min-max ranges were 0.6-8.3% in spring and 1.2-4.8% in summer), possibly suggesting reduced genetic diversity or physiological canalization. Protein plasticity is relevant to cope with present and upcoming environmental variation related to anthropogenic forcing (e.g. global change, pollution) but low inter-individual variation may limit evolutionary potential of shrimp populations.

Ocean warming alters cellular metabolism and induces mortality in fish early life stages: A proteomic approach.

Climate change has pervasive effects on marine ecosystems, altering biodiversity patterns, abundance and distribution of species, biological interactions, phenology, and organisms' physiology, performance and fitness. Fish early life stages have narrow thermal windows and are thus more vulnerable to further changes in water temperature. The aim of this study was to address the sensitivity and underlying molecular changes of larvae of a key fisheries species, the sea bream Sparus aurata, towards ocean warming. Larvae were exposed to three temperatures: 18°C (control), 24°C (warm) and 30°C (heat wave) for seven days. At the end of the assay, i) survival curves were plotted for each temperature treatment and ii) entire larvae were collected for proteomic analysis via 2D gel electrophoresis, image analysis and mass spectrometry. Survival decreased with increasing temperature, with no larvae surviving at 30°C. Therefore, proteomic analysis was only carried out for 18°C and 24°C. Larvae up-regulated protein folding and degradation, cytoskeletal re-organization, transcriptional regulation and the growth hormone while mostly down-regulating cargo transporting and porphyrin metabolism upon exposure to heat stress. No changes were detected in proteins related to energetic metabolism suggesting that larval fish may not have the energetic plasticity needed to sustain cellular protection in the long-term. These results indicate that despite proteome modulation, S. aurata larvae do not seem able to fully acclimate to higher temperatures as shown by the low survival rates. Consequently, elevated temperatures seem to have bottleneck effects during fish early life stages, and future ocean warming can potentially compromise recruitment's success of key fisheries species.

Influence of temperature in thermal and oxidative stress responses in estuarine fish.

The influence of increasing temperatures in thermal and oxidative stress responses were studied in the muscle of several estuarine fish species (Diplodus vulgaris, Diplodus sargus, Dicentrarchus labrax, Gobius niger and Liza ramada). Selected fish were collected in July at the Tagus estuary (24±0.9°C; salinity of 30±4‰; pH=8). Fish were subjected to a temperature increase of 1°C.h(-1) until they reached their Critical Thermal Maximum (CTMax), starting at 24°C (control temperature). Muscle samples were collected during the trial and results showed that oxidative stress biomarkers are highly sensitive to temperature. Results from stress oxidative enzymes show alterations with increasing temperature in all tested species. Catalase (CAT; EC 1.11.1.6) activity significantly increased in L. ramada, D. labrax and decreased in D. vulgaris. Glutathione S-transferase (GST; EC 2.5.1.18) activity increased in L. ramada, D. sargus, D. vulgaris, and D. labrax. In G. niger it showed a cycle of increase-decrease. Lipid peroxidation (LPO) increased in L. ramada, D. sargus and D. labrax. With respect to correlation analysis (Pearson; Spearman r), the results showed that oxidation products and antioxidant defenses were correlated in L. ramada (LPO-CAT and LPO-GST, D. sargus (LPO-CAT), and D. labrax (LPO-CAT). Oxidative biomarkers were correlated with thermal stress biomarker (Hsp70) in L. ramada (CAT-Hsp70), D. vulgaris (LPO-Hsp70), D. labrax (GST-Hsp70) and G. niger (LPO-Hsp70). In conclusion, oxidative stress does occur with increasing temperatures and there seems to be a relation between thermal stress response and oxidative stress response. The results suggest that oxidative stress biomarkers should be applied with caution, particularly in field multi-species/multi-environment studies.

Thermal tolerance of the crab Pachygrapsus marmoratus: intraspecific differences at a physiological (CTMax) and molecular level (Hsp70).

Temperature is one of the most important variables influencing organisms, especially in the intertidal zone. This work aimed to test physiological and molecular intraspecific differences in thermal tolerance of the crab Pachygrapsus marmoratus (Fabricius, 1787). The comparisons made focused on sex, size, and habitat (estuary and coast) differences. The physiological parameter was upper thermal limit, tested via the critical thermal maximum (CTMax) and the molecular parameter was total heat shock protein 70 (Hsp70 and Hsp70 plus Hsc70) production, quantified via an enzyme-linked imunosorbent assay. Results showed that CTMax values and Hsp70 production are higher in females probably due to different microhabitat use and potentially due to different hormonal regulation in males and females. Among females, non-reproducing ones showed a higher CTMax value, but no differences were found in Hsp70, even though reproducing females showed higher variability in Hsp70 amounts. As reproduction takes up a lot of energy, its allocation for other activities, including stress responses, is lower. Juveniles also showed higher CTMax and Hsp70 expression because they occur in greater shore heights and ageing leads to alterations in protein synthesis. Comparing estuarine and coastal crabs, no differences were found in CTMax but coastal crabs produce more Hsp70 than estuarine crabs because they occur in drier and hotter areas than estuarine ones, which occur in moister environments. This work shows the importance of addressing intraspecific differences in the stress response at different organizational levels. This study shows that these differences are key factors in stress research, climate research, and environmental monitoring.

Morphometric study of the frontal cortex in subacute sclerosing panencephalitis.

In biopsic material collected from the frontal cortex of 6 patients with subacute sclerosing panencephalitis (SSPE) and 5 patients with posterior fossa tumors, we estimated the neuronal and synaptic numerical densities as well as the mean volume of the neurons from layers II and III. The thickness of these layers was also determined. The evaluation of the layer's thickness suggested that there was no difference in the shrinkage in SSPE as compared to controls. No differences were found between the neuronal numerical densities and the neuronal soma sizes from SSPE and controls. Conversely the synaptic numerical density was reduced in SSPE. Given the maintenance of the neuronal numerical density in the frontal cortex of patients with SSPE, the presence of a decreased density of synapses must be regarded as a consequence of the dendritic and axonal degeneration that we previously described in this condition. It must then be borne in mind that SSPE's functional and behavioral changes might spring from alterations of the frontal cortex neuronal circuitry.

Surgical results for proliferative vitreoretinopathy.

We reviewed 88 consecutive eyes that underwent vitrectomy for retinal detachment with proliferative vitreoretinopathy (PVR) and were followed a minimum of six months. A primary goal of the surgery was the meticulous trimming of the vitreous base in hopes of decreasing the incidence of post-operative reproliferation and anterior PVR. Those eyes with anterior PVR had aggressive release of vitreous base contraction (anteroposterior and circumferential) with intraocular scissors. All posterior tractional membranes were removed. All eyes received long-acting gas for postoperative retinal tamponade. Macular reattachment was achieved in 78 (88.6%) eyes. Forty-six (52.3%) obtained at least 5/200 vision. Seventeen (19%) eyes were re-operated at least once. We compared the importance of initial lens status (pseudophakic, aphakic, phakic), need for relaxing retinotomy, presence of anterior PVR, and history of previous vitrectomy on the anatomic and visual results. No single factor was responsible for a statistically significant effect on either vision or anatomic success, except for the need for a relaxing retinotomy, which carried with it a decreased chance of an eye obtaining 5/200 vision (Fisher's exact test, p = 0.03).

Central serous chorioretinopathy occurring in patients 60 years of age and older.

The authors report on 13 eyes in 13 patients, 60 years of age or older, with idiopathic central serous chorioretinopathy, a condition that typically presents in adults between the ages of 30 and 50 years. In older patients, this condition can easily be mistaken for macular degeneration with subretinal neovascularization. None of the patients in this series had soft drusen, geographic atrophy, or subretinal neovascularization, signs of age-related macular degeneration or other retinal or macular disease. Subretinal neovascularization was not seen either at the time of initial diagnosis or during follow-up. The clinical, biomicroscopic, and fluorescein angiographic characteristics of this entity are described. The clinical course of 7 of these 13 eyes that underwent laser photocoagulation treatment is also described.

Progressive enlargement of laser scars following grid laser photocoagulation for diffuse diabetic macular edema.

Laser photocoagulation in a grid pattern is effective in many eyes in resolving diffuse diabetic macular edema and stabilizing vision. We retrospectively studied 203 eyes of 203 patients, all of whom had diabetic macular edema treated with grid laser photocoagulation. During the follow-up period, 11 of these 203 eyes developed enlargement of the laser scars that progressed into the central fovea. Each of the 11 eyes experienced loss of vision, and in five, the visual loss was significant. Five of these eyes also developed a retinal pigment hyperplastic scar. After the laser treatment, but before the scars enlarged, the visual acuity of these eyes was unchanged from that before treatment. But after the atrophic scars enlarged into the central fovea, visual acuity in one eye decreased from 20/40 to 20/100, and the other 10 eyes had visual acuities of 20/200 or worse.