Prostate-specific membrane antigen PET/computed tomography for staging prostate cancer.

PURPOSE OF REVIEW: Molecular imaging with PET/CT targeting the prostate-specific membrane antigen (PSMA) receptor is increasingly utilized in men with prostate cancer (PCa), with clinical indications now expanding beyond biochemical recurrence. PSMA PET/CT often detects sub-centimetre size pathologic nodes and low-volume bone marrow disease that are occult on conventional imaging when the lesion does not cause sclerosis or osteoblastic reaction in surrounding bone. This review focuses on recent evidence for PSMA PET/CT in initial disease staging. RECENT FINDINGS: Several recent studies including a large randomized trial have evaluated the clinical impact of PSMA PET/CT in initial staging of PCa. PSMA PET/CT is more sensitive and accurate than the conventional imaging standard of CT and bone scan. Change in treatment plan or modality of therapy occurs frequently when PSMA PET/CT forms part of the diagnostic algorithm. Hybrid PET/MRI also has potential utility, particularly in evaluating pelvic disease, but evidence base remains very limited. SUMMARY: PSMA PET/CT has emerged as a new standard in primary staging of PCa. Reimbursement by national funding bodies and incorporation into international clinical guidelines is anticipated within the next few years.

Temporary Membrane Permeabilization via the Pore-Forming Toxin Lysenin.

Pore-forming toxins are alluring tools for delivering biologically-active, impermeable cargoes to intracellular environments by introducing large conductance pathways into cell membranes. However, the lack of regulation often leads to the dissipation of electrical and chemical gradients, which might significantly affect the viability of cells under scrutiny. To mitigate these problems, we explored the use of lysenin channels to reversibly control the barrier function of natural and artificial lipid membrane systems by controlling the lysenin's transport properties. We employed artificial membranes and electrophysiology measurements in order to identify the influence of labels and media on the lysenin channel's conductance. Two cell culture models: Jurkat cells in suspension and adherent ATDC5 cells were utilized to demonstrate that lysenin channels may provide temporary cytosol access to membrane non-permeant propidium iodide and phalloidin. Permeability and cell viability were assessed by fluorescence spectroscopy and microscopy. Membrane resealing by chitosan or specific media addition proved to be an effective way of maintaining cellular viability. In addition, we loaded non-permeant dyes into liposomes via lysenin channels by controlling their conducting state with multivalent metal cations. The improved control over membrane permeability might prove fruitful for a large variety of biological or biomedical applications that require only temporary, non-destructive access to the inner environment enclosed by natural and artificial membranes.

Non-obstructive membrane of left atrial appendage orifice: first paediatric report.

Left atrial appendage membrane is a rare anomaly. Its implications on clinical course are unknown. We report the first paediatric case in association with a congenital heart disease.

Induced membrane maintains its osteogenic properties even when the second stage of Masquelet's technique is performed later.

PURPOSE: Previous clinical studies have shown the effectiveness of bone repair using two-stage surgery called the induced membrane (IM) technique. The optimal wait before the second surgery is said to be 1 month. We have been successfully performing the IM technique while waiting an average of 6 months to carry out the second stage. We hypothesised that the IM maintains its beneficial capabilities, even at a later second stage, and that there is no relation between the speed of bone union and the wait between the first and second stage. We sought to explore the biological properties of 'older' IMs sampled to substantiate our clinical observations. METHODS: Thirty-four patients with a critical size defect were treated with the IM technique. In seven of these patients, pieces of the IM were collected 4.2-14.7 months after the first surgery. IM-derived cell phenotype and osteogenic potential were investigated using in vitro studies (n = 4) while IM nature and function were investigated by histology and immunohistochemistry (n = 3). RESULTS: The median wait before the second surgery was 5.8 months [range 1.2-14.7] and bone healing occurred at 7.6 months [range 2.5-49.9] for 26 patients. IMs aged 4.2-14.7 months contained mesenchymal stromal cells with in vitro osteogenic potential and corresponded to a multipotent tissue with osteogenic and chondrogenic capabilities contributing to osteogenesis over time. CONCLUSION: This preliminary study suggests the IM retains its powerful osteogenic properties over time and that waiting longer between the two surgeries does not delay bone union.

Fluid viscosity but not surface tension, determines the tamponade effect of intravitreal fluids in a novel in vitro eye model of retinal detachment.

PURPOSE: To determine the effect of varying surface tension and viscosity of fluids used as tamponade in an in vitro eye model of retinal detachment. METHODS: We used an in vitro eye model simulating retinal detachment. Fluids with varying surface tension and identical viscosity, and fluids with varying viscosities and identical surface tension were used as tamponade agents to prevent retinal detachment in the model, to determine which of these properties affects each fluid's effectiveness as a retinal tamponade. RESULTS: The membrane (simulating retinal detachment) changes over time in a vitro eye model were not affected by varying surface tension given constant fluid viscosity. However, membrane changes were proportional to the viscosity of the fluid, given constant surface tension. CONCLUSIONS: The tamponade effect of an intravitreal fluid against retinal detachment may not be related as previously assumed, solely to surface tension, but rather is proportionally related to its viscosity.

Influence of irrigation dynamic pressure-assisted hydrodissection on intraocular pressure and the posterior chamber-anterior hyaloid membrane barrier during cataract surgery.

PURPOSE: To evaluate the effects of irrigation dynamic pressure-assisted hydrodissection (irrigation-hydro: iH) on intraocular pressure (IOP) and the posterior chamber-anterior hyaloid membrane (PC-AHM) barrier in porcine eyes. STUDY DESIGN: Experimental. METHODS: In Experiment 1, IOP was recorded while irrigating the anterior chamber (AC), during iH, and during phacoemulsification and aspiration in 20 porcine eyes using bottle heights of 50, 70, and 90 cm. Under the same conditions, IOP was recorded during conventional manual cortical cleaving hydrodissection (manual hydro: mH) in 20 porcine eyes. In Experiment 2, after iH, ACs were perfused for 5 seconds with balanced salt solution containing 1.0-µm fluorescein beads in 20 porcine eyes using bottle heights of 70, 118, and 169 cm. PC-AHM barrier staining grade was evaluated by the Miyake-Apple view. RESULTS: iH proved successful in all cases. In Experiment 1, IOP during iH was relatively stable and peak IOP was below the baseline bottle height-dependent pressure. No eyes showed a peak IOP > 75 mmHg during iH, but 8 eyes showed a peak IOP > 75 mmHg during mH. In Experiment 2, neither AHT nor ruptured capsules were observed at any bottle height. CONCLUSION: Unlike mH, IOP during iH was relatively stable without any high peak IOP. Thus, iH offers a simple technique for reducing peak IOP and avoiding disturbance of the PC-AHM barrier.

A rare case of persistent pupillary membrane: Case-based approach and management.

Persistent pupillary membranes (PPMs) are a common congenital anomaly seen in 95% of neonates. Extensive PPMs, occluding the visual axis and resulting in reduced visual acuity, are relatively uncommon. We describe a case of bilateral total PPM in a 36-year-old female who presented with complaints of blurred vision in both the eyes. Dense pupillary membranes obscuring the visual axis need early surgical treatment. It is essential that the lens status remains clear along the visual axis both before and after pupilloplasty.

Electrochemical Impedance Spectroscopy for Real-Time Detection of Lipid Membrane Damage Based on a Porous Self-Assembly Monolayer Support.

Layer-by-layer dissolution and permeable pore formation are two typical membrane damage pathways, which induce membrane function disorder and result in serious disease, such as Alzheimer's disease, Keshan disease, Sickle-cell disease, and so on. To effectively distinguish and sensitively monitor these two typical membrane damage pathways, a facile electrochemical impedance strategy was developed on a porous self-assembly monolayer (pSAM) supported bilayer lipid membrane (BLM). The pSAM was prepared by selectively electrochemical reductive desorption of the mercaptopropionic acid in a mixed mercaptopropionic acid/11-mercaptoundecanoic acid self-assembled monolayer, which created plenty of nanopores with tens of nanometers in diameter and several nanometers in height (defined as inner-pores). The ultralow aspect ratio of the inner-pores was advantageous to the mass transfer of electrochemical probe [Fe(CN)6]3-/4-, simplifying the equivalent electric circuit for electrochemical impedance spectroscopy analysis at the electrode/membrane interface. [Fe(CN)6]3-/4- transferring from the bulk solution into the inner-pore induce significant changes of the interfacial impedance properties, improving the detection sensitivity. Based on these, the different membrane damage pathways were effectively distinguished and sensitively monitored with the normalized resistance-capacitance changes of inner-pore-related parameters including the electrolyte resistance within the pore length ( Rpore) and the metal/inner-pore interfacial capacitance ( Cpore) and the charge-transfer resistance ( Rct-in) at the metal/inner-pore interface.

Endothelin-1 is associated with fibrosis in proliferative diabetic retinopathy membranes.

PURPOSE: To characterize the relationship between endothelin-1 and fibrosis in epiretinal membranes in proliferative diabetic retinopathy and explore the role of endothelial-mesenchymal transition in these membranes. METHODS: Membranes were obtained from eyes undergoing pars plana vitrectomy for complicated proliferative diabetic retinopathy or idiopathic epiretinal membrane. Through standard immunohistochemical techniques, we labeled membranes to explore the distribution of endothelin-1 and endothelin receptor B, comparing proliferative diabetic retinopathy and idiopathic epiretinal membranes. In addition, membranes were also labeled with markers for fibroblasts, endothelial, and glial cells and studied with confocal laser scanning microscopy. The intensity of endothelin-1 labeling was quantified using standard image analysis software. RESULTS: Fourteen membranes were included in the analysis, nine from eyes with proliferative diabetic retinopathy and five idiopathic membranes. Flatmount diabetic membranes showed co-localization of endothelin-1 with S100A4 and CD31. Immunohistochemistry and quantitative analysis of cross-sectional membranes showed significantly higher endothelin-1 labeling in proliferative diabetic retinopathy membranes compared to idiopathic membranes (p<0.05). Diabetic membranes showed more elements staining positive for S100A4 compared to idiopathic membranes. CONCLUSION: Epiretinal membrane formation in proliferative diabetic retinopathy involves higher tissue levels of endothelin-1 and fibroblastic activity. Furthermore, endothelin-1, endothelial and fibroblastic staining appear to be correlated, suggestive of endothelial-to-mesenchymal transition in proliferative diabetic retinopathy.

Altered membrane integrity in the progression of muscle diseases.

Sarcolemmal integrity is orchestrated through the interplay of preserving membrane strength and fast tracking the membrane repair process during an event of compromised membrane fragility. Several molecular players have been identified that act in a concerted fashion to maintain the barrier function of the muscle membrane. Substantial research findings in the field of muscle biology point out the importance of maintaining membrane integrity as a key contributory factor to cellular homeostasis. Innumerable data on the progression of membrane pathology associated with compromised muscle membrane integrity support targeting sarcolemmal integrity in skeletal and cardiac muscle as a model therapeutic strategy to alleviate some of the pathologic conditions. This review will discuss strategies that researchers have undertaken to compensate for an imbalance in sarcolemma membrane fragility and membrane repair to maintain muscle membrane integrity.

Host Cell S Phase Restricts Legionella pneumophila Intracellular Replication by Destabilizing the Membrane-Bound Replication Compartment.

Legionella pneumophila grows within cells ranging from environmental amoebae to human macrophages. In spite of this conserved strategy of pathogenesis, identification of host factors that restrict L. pneumophila intracellular replication has not been extended outside components of the mammalian innate immune response. We performed a double-stranded RNA (dsRNA) screen against more than 50% of the Drosophila melanogaster annotated open reading frames (ORFs) to identify host cell factors that restrict L. pneumophila The majority of analyzed dsRNAs that stimulated L. pneumophila intracellular replication were directed against host proteins involved in protein synthesis or cell cycle control. Consistent with disruption of the cell cycle stimulating intracellular replication, proteins involved in translation initiation also resulted in G1 arrest. Stimulation of replication was dependent on the stage of cell cycle arrest, as dsRNAs causing arrest during S phase had an inhibitory effect on intracellular replication. The inhibitory effects of S phase arrest could be recapitulated in a human cell line, indicating that cell cycle control of L. pneumophila replication is evolutionarily conserved. Synchronized HeLa cell populations in S phase and challenged with L. pneumophila failed to progress through the cell cycle and were depressed for supporting intracellular replication. Poor bacterial replication in S phase was associated with loss of the vacuole membrane barrier, resulting in exposure of bacteria to the cytosol and their eventual degradation. These results are consistent with the model that S phase is inhibitory for L. pneumophila intracellular survival as a consequence of failure to maintain the integrity of the membrane surrounding intracellular bacteria.IMPORTANCELegionella pneumophila has the ability to replicate within human macrophages and amoebal hosts. Here, we report that the host cell cycle influences L. pneumophila intracellular replication. Our data demonstrate that the G1 and G2/M phases of the host cell cycle are permissive for bacterial replication, while S phase is toxic for the bacterium. L. pneumophila replicates poorly within host cells present in S phase. The inability of L. pneumophila to replicate relies on its failure to control the integrity of its vacuole, leading to cytosolic exposure of the bacteria and eventual degradation. The data presented here argue that growth-arrested host cells that are encountered by L. pneumophila in either the environment or within human hosts are ideal targets for intracellular replication because their transit through S phase is blocked.

Adaptations in rod outer segment disc membranes in response to environmental lighting conditions.

The light-sensing rod photoreceptor cell exhibits several adaptations in response to the lighting environment. While adaptations to short-term changes in lighting conditions have been examined in depth, adaptations to long-term changes in lighting conditions are less understood. Atomic force microscopy was used to characterize the structure of rod outer segment disc membranes, the site of photon absorption by the pigment rhodopsin, to better understand how photoreceptor cells respond to long-term lighting changes. Structural properties of the disc membrane changed in response to housing mice in constant dark or light conditions and these adaptive changes required output from the phototransduction cascade initiated by rhodopsin. Among these were changes in the packing density of rhodopsin in the membrane, which was independent of rhodopsin synthesis and specifically affected scotopic visual function as assessed by electroretinography. Studies here support the concept of photostasis, which maintains optimal photoreceptor cell function with implications in retinal degenerations.

Morphology and clinical importance of epidural membrane and periradicular fibrous tissue in lumbar spinal stenosis.

PURPOSE: Compared to the ligamentum flavum (LF), morphology of the epidural membrane (EM) and the periradicular fibrous tissue (PRFT) has been largely ignored in studies of lumbar spinal stenosis (LSS). The aim of this prospective study was to elucidate the morphologies and clinical importance of the EM and PRFT in LSS. METHODS: Before starting this study, neural compressive EM (c-EM) and PRFT (c-PRFT) were defined as follows based on our microsurgical experience and a literature review. The c-EM is a constriction band or membrane obstructing dural tube expansion, and the c-PRFT is a fibrous tissue that compresses the nerve root and/or restricts its mobility. This study enrolled 134 patients who underwent microscopic decompression at L4/5. The morphologies of each patient's EM and PRFT were observed and recorded. Specimens were obtained from randomly selected patients for histological evaluation. RESULTS: The EM and PRFT exhibited a wide morphological spectrum, from a fine strand to a substantial membrane. The c-EM alone was observed in four cases, the c-PRFT alone in 37 cases, and both in three cases. The c-PRFT was more frequently observed in patients with degenerative spondylolisthesis than in those without olisthesis (P < 0.05). Several cases exhibited interesting histological findings including many small arteries, chondrometaplasia, ganglion-like cyst formation, and hyalinized collagen fibers. CONCLUSIONS: Some EM and PRFT transform into degenerative and substantial fibrous tissues during the process of symptomatic LSS development. Such morphological and histological changes can cause dural tear, symptomatic epidural hematoma, and/or inadequate decompression.

Laparoscopic total extraperitoneal repair of preoperatively diagnosed bilateral obturator and incidental bilateral femoral herniae.

Obturator hernia (OH), a rare type of hernia, is associated with high morbidity and mortality. Diagnosis is often delayed as clinical symptoms are typically non-specific. OH is frequently associated with other occult inguinopelvic herniae. Early diagnosis is vital to decrease morbidity and mortality. We report the case of a 75-year-old woman who presented to the surgical outpatients' department with non-specific bilateral groin pain radiating to the thighs. CT of the pelvis demonstrated bilateral OH with no radiological evidence of bowel obstruction. Semiurgent elective laparoscopic total extraperitoneal mesh repair was performed. Intraoperative findings confirmed bilateral obturator herniae as well as incidental bilateral femoral herniae. This case highlights the need for a high index of suspicion for such concomitant hernias that, in the presence of OH, may only be identified intraoperatively.

Autophagy Proteins Promote Repair of Endosomal Membranes Damaged by the Salmonella Type Three Secretion System 1.

Salmonella Typhimurium (S.Tm) is an enteropathogen requiring multiple virulence factors, including two type three secretion systems (T1 and T2). T1 triggers epithelium invasion in which the bacteria are taken up into endosomes that mature into Salmonella-containing vacuoles (SCV) and trigger T2 induction upon acidification. Mechanisms controlling endosome membrane integrity or pathogen egress into the cytosol are incompletely understood. We screened for host factors affecting invasion and SCV maturation and identified a role for autophagy in sealing endosomal membranes damaged by T1 during host cell invasion. S.Tm-infected autophagy-deficient (atg5(-/-)) cells exhibit reduced SCV dye retention and lower T2 expression but no effects on steps preceding SCV maturation. However, in the absence of T1, autophagy is dispensable for T2 induction. These findings establish a role of autophagy at early stages of S.Tm infection and suggest that autophagy-mediated membrane repair might be generally important for invasive pathogens and endosomal membrane function.

[Validity of the Morawietz classification for evaluation of periprosthetic tissue]. / Prínos Morawietzovy klasifikace k hodnocení periprotetických tkání.

PURPOSE OF THE STUDY A consensual classification of the periprosthetic interface membrane obtained at revision total joint arthroplasty was published by Morawietz et al. in 2006. Based on histomorphological criteria, four types of periprosthetic membrane were proposed: type I, aseptic failure; type II, septic failure; type III, combined type (carrying signs of both type I and II); and type IV, indeterminate type. The aim of this study was to find out whether and to what extent the Morawietz system would be suitable for use at an independent institution involved in the evaluation of periprosthetic membranes for a long time. Should it appear that the institution achieved an equally good or even better agreement between the clinical diagnosis and the histopathological finding, this consensus classification could be recommended for routine use. MATERIAL AND METHODS The samples of periprosthetic tissue evaluated in this study were obtained during surgery from the following groups of patients: 66 patients with aseptic loosening of total hip (THA) or knee arthroplasty, 15 patients with infection of THA, 16 patients with THA without any signs of aseptic loosening, osteolysis or infection; 8 patients with hip osteoarthritis and 8 patients with knee osteoarthritis. Sample collection and processing (for purposes of histomorphological evaluation and immunohistochemical staining) was performed according to the established protocol. The tissue samples evaluation was made by an experienced pathologist hand in hand with the method described in the original paper by Morawietz et al. For a more detailed tissue analysis, selected antibodies (CD4, CD8, CD20, IFN-γ and Hsp-60) were visualized by immunohistochemistry. RESULTS The majority of samples from aseptic reoperations were classified as membranes of the type I (79%) and III (16%). Specimens retrieved from septic cases were mostly classified as membranes of type II and III (60% together). The septic membranes showed a significantly higher expression of CD20 protein when compared with both the aseptic (p < 0.0001) and control THA samples (p = 0.003). The membranes retrieved from the surroundings of a stable THA without osteolysis and infection had lower expression levels of Hsp60 and IFN-γ, when compared with those from both aseptic and septic loosening. Finally, Hsp-60 expression was significantly higher in osteoarthritic tissue than in samples from stable THA (p = 0.041). DISCUSSION Morawietz et al. proposed a standardized classification system for evaluation of periprosthetic tissue. As any attempt at generalization of a complex issue, this proposal has certain shortcomings. One of these is poor detection of chronic and low-grade infections. A method that would improve the conventional counting of polymorphonuclear leukocytes is still being sought. In this connection, immunostaining for CD20 combined with an assessment of antimicrobial peptides may be a promising option. The supplementary specimen staining showed that pseudosynovial tissue is much more active in patients carrying infection and the least active in samples from stable THA in which certain tolerance and thus tissue homeostasis might be expected. CONCLUSIONS 1. In this study the distribution of findings classified according to the Morawietz system was similar to the results published in the original study from 2006. 2. The definition of an aseptic membrane (type I) in the Morawietz system meets the requirements of clinical practice (agreement, about 80%). 3. An increased sensitivity for infectious membrane detection can be achieved by using supplementary immunohistochemical staining effective particularly in chronic and low-grade infections. 4. Painless and stable THAs typically have very low expression levels of CD4, CD20 and Hsp-60 proteins, and interferon- -gamma (IFN-γ) as well. Key words: total hip arthroplasty, total knee arthroplasty, aseptic loosening, prosthetic joint infection, tissue analysis, membranes, CD receptors, Hsp-60 protein, IFN-γ.

The Function of the Distal Interosseous Membrane and its Relevance to the Stability of the Distal Radioulnar Joint: An Anatomical and Biomechanical Review.

The purpose of this article is to review functional anatomy and biomechanics of the distal interosseous membrane (DIOM) and its relevance to the stability of the distal radioulnar joint. The intact DIOM constrained dorsal dislocation of the radius, but it seldom constrained palmar dislocation. A residual ulnar translation deformity of the radial shaft in distal radius fractures has the potential to cause the distal radioulnar joint instability when the triangular fibrocartilage complex injury is also present, because it may result in detensioning of DIOM. Ulnar shortening with the osteotomy performed proximal to the attachment of the DIOM had a more favorable effect on stability of the DRUJ compared with the effect of distal osteotomy, especially in the presence of the distal oblique bundle (DOB). The longitudinal resistance to ulnar shortening was significantly greater in proximal shortening than in distal shortening.

Amniotic membrane transplant for articular cartilage repair: an experimental study in sheep.

PURPOSE: The aim of the present study was to compare the potential for cartilage repair of fresh amniotic membrane (AM), cryopreserved AM and cryopreserved AM previously cultured with bone marrow mesenchymal stem cells (BM-MSCs) in an in vivo sheep animal model. METHODS: A full-thickness cartilage defect was surgically produced in 12 adult sheep, in the bearing region of the lateral femoral condyle. The animals were randomized into 4 groups (n=3): no treatment of the defect (G1); filling with fresh AM (G2); with cryopreserved AM previously cultivated with BM-MSCs (G3); with cryopreserved AM alone (G4). Postoperatively, the full load was possible. At two months, the animals were euthanized. The quality of the new synthesized tissue was evaluated with the macroscopic, by using International Cartilage Repair Society (ICRS) scale, and histological analyses, by using O'Driscoll scale. RESULTS: The control samples showed an ICRS grade III (abnormal); while the samples of Groups 2, 3 and 4 reported a grade II (similar to healthy cartilage). The mean value of O'Driscoll scale in the control group (3.3) was significantly lower compared to the treatment groups (G2: 10.7; G3: 8; G4: 11.3) (P <0.05). No significant differences were found between the experimental groups. CONCLUSION: AM could be a suitable material for the management of articular cartilage defects. Stem cells within AM demonstrated to be able to differentiate in chondrocytes in vivo. Fresh AM, cryopreserved AM and cryopreserved AM previously cultivated with BM-MSCs showed similar regenerative properties.

Clinical characteristics and surgical approach to visually significant persistent pupillary membranes.

BACKGROUND: Infants with hyperplastic persistent pupillary membranes (PPM) may be at risk for deprivation amblyopia due to obstructions of the visual axis. We describe the long-term visual and anatomic outcomes of a surgical technique for their removal. METHODS: The medical records of consecutive patients <3 years of age who underwent surgical removal of PPMs between December 1998 and May 2012 were retrospectively reviewed. Each PPM was judged to be visually significant based on poor visual acuity, poor retinoscopic reflex, or inability to visualize the fundus. The surgical technique included injection of a viscoelastic agent beneath the pupillary strands to bow them anteriorly, careful peeling of residual adherent strands from the anterior lens capsule, and lysis of the strands at the pupillary margin with intraocular scissors. Pre- and postoperative visual and anatomic results were recorded. RESULTS: This case series included 10 eyes of 6 patients: PPMs were bilateral in 4 patients and unilateral in 2. The patient age at time of surgery ranged from 2.5 months to 2.5 years (mean, 14 months). Mean postoperative follow-up was 5.3 years (range, 2.5-8 years). All patients had successful clearance of the visual axis and good visual acuity. No intraoperative complications occurred. CONCLUSIONS: All patients in this series had excellent visual and structural outcomes, with no significant complications. The technique described here may be considered for patients with visually significant PPMs to improve visual function and pupil appearance.