Abstract Introduction Meniscal scaffold implants support the in-growth of new "meniscus like" tissue with the aim of alleviating post-meniscectomy knee pain and preventing further articular cartilage ...degeneration. Patients and methods Twenty-three patients underwent meniscal scaffold implantation (14 medial, 9 lateral) with either the Menaflex (ReGen Biologics) (n = 12) or Actifit (Orteq) (n = 11) scaffolds. Minimum follow-up was 1 year with a mean of 24.1 months (18–27) for the Menaflex and 14.7 months (12–18) for the Actifit groups. Mean age at surgery was 35 years (17–47) with a mean Outerbridge grade of 1.9 in the affected compartment. Eight (36%) underwent concurrent osteotomy, ligament reconstruction or microfracture of the tibial plateau. KOOS, Lysholm, Tegner activity and IKDC scores were collected pre-operatively and at six-month interval post-surgery. Assessment of the reconstruction was obtained with MRI scanning and arthroscopy. One scaffold tore and was revised at 19 months post-operatively. Results Twenty-one out of 23 (91.3%) had a significant improvement in knee scores when compared to pre-surgery levels at latest follow-up. Second-look arthroscopy in 14 at 1-year post-implantation showed variable amounts of regenerative tissue. There was no progression in chondral wear noted on repeat MRI scanning. Conclusion Treatment with meniscal scaffold implants can provide good pain relief for the post-meniscectomy knee following partial meniscectomy. Longer follow-up is required to ascertain whether they also prevent the progressive chondral wear associated with a post-meniscectomy knee.
Introduction: To review outcomes of medically inoperable patients treated with stereotactic body radiation therapy (SBRT) for multiple primary lung cancer (MPLC).
Methods: We retrospectively reviewed ...the charts of 10 patients (21 lesions) treated with SBRT for synchronous (seven), metachronous (one) or synchronous/metachronous lung cancers. All patients were male, medically inoperable and had a median age of 66 years. Eight patients had bilateral disease and two had unilateral disease. All patients had a histological diagnosis in at least one of the two lesions and four patients (44.4%) had both lesions biopsied. There were 18 T1 lesions and three T2 lesions. SBRT was in three fractions of 20 Gy or five fractions of 11–12 Gy to each lesion.
Results: Mean and median follow up were 18.8 and 15.5 months, respectively. At analysis, six patients (60.0%) are alive, and five of these living patients (83.3%) have no evidence of disease recurrence or progression. Four patients (44.4%) developed distant metastatic disease. Twenty lesions (95.2%) achieved in‐field local control. No patients experienced acute pulmonary complications and only two patients (22.2%) experienced late grade I lung toxicity as per the Radiation Therapy Oncology Group toxicity criteria.
Conclusion: SBRT for MPLC in medically inoperable patients is a safe, feasible and effective treatment approach.
Visual signal transduction takes place on the surface of flat membrane vesicles called photoreceptor discs, which reside inside the light-sensitive outer segment organelle of vertebrate photoreceptor ...cells. Although biochemical studies have indicated that discs are built with a handful of highly specialized proteins, proteomic studies have yielded databases consisting of hundreds of entries. We addressed this controversy by employing protein correlation profiling, which allows identification of unique components of organelles that can be fractionated but not purified to absolute homogeneity. We subjected discs to sequential steps of fractionation and identified the relative amounts of proteins in each fraction by label-free quantitative mass spectrometry. This analysis demonstrated that the photoreceptor disc proteome contains only eleven components, which satisfy the hallmark criterion for being unique disc-resident components: the retention of a constant molar ratio among themselves across fractionation steps. Remarkably, one of them is PRCD, a protein whose mutations have been shown to cause blindness, yet cellular localization remained completely unknown. Identification of PRCD as a novel disc-specific protein facilitates understanding its functional role and the pathobiological significance of its mutations. Our study provides a striking example how protein correlation profiling allows a distinction between constitutive components of cellular organelles and their inevitable contaminants.
The purpose of this study was to evaluate the impact of daily setup error and interfraction organ motion on the overall dosimetric radiation treatment plans. Twelve patients undergoing definitive ...intensity-modulated radiation therapy (IMRT) treatments for prostate cancer were evaluated in this institutional review board-approved study. Each patient had fiducial markers placed into the prostate gland before treatment planning computed tomography scan. IMRT plans were generated using the Eclipse treatment planning system. Each patient was treated to a dose of 8100 cGy given in 45 fractions. In this study, we retrospectively created a plan for each treatment day that had a shift available. To calculate the dose, the patient would have received under this plan, we mathematically "negated" the shift by moving the isocenter in the exact opposite direction of the shift. The individualized daily plans were combined to generate an overall plan sum. The dose distributions from these plans were compared with the treatment plans that were used to treat the patients. Three-hundred ninety daily shifts were negated and their corresponding plans evaluated. The mean isocenter shift based on the location of the fiducial markers was 3.3 ± 6.5 mm to the right, 1.6 ± 5.1 mm posteriorly, and 1.0 ± 5.0 mm along the caudal direction. The mean D95 doses for the prostate gland when setup error was corrected and uncorrected were 8228 and 7844 cGy (p < 0.002), respectively, and for the planning target volume (PTV8100) was 8089 and 7303 cGy (p < 0.001), respectively. The mean V95 values when patient setup was corrected and uncorrected were 99.9% and 87.3%, respectively, for the PTV8100 volume (p < 0.0001). At an individual patient level, the difference in the D95 value for the prostate volume could be >1200 cGy and for the PTV8100 could approach almost 2000 cGy when comparing corrected against uncorrected plans. There was no statistically significant difference in the D35 parameter for the surrounding normal tissue except for the dose received by the penile bulb and the right hip. Our dosimetric evaluation suggests significant underdosing with inaccurate target localization and emphasizes the importance of accurate patient setup and target localization. Further studies are needed to evaluate the impact of intrafraction organ motion, rotation, and deformation on doses delivered to target volumes.
Gram-negative bacteria typically overcome poor permeability of outer membranes through general porins like OmpF and OmpC, which form water-filled transmembrane pores permitting diffusion of ...hydrophilic molecules with no particular selectivity. Many bacteria lacking such general porins use substrate-specific porins to overcome growth-limiting conditions and facilitate selective transport of metabolites. Exclusive reliance on substrate-specific porins yields lower membrane permeability to small molecules (<600 Da) versus that seen for Escherichia coli. In Pseudomonads, transit of most small molecules across the cell membrane is thought to be mediated by substrate-specific channels of the OprD superfamily. This property explains, at least in part, the high incidence of Pseudomonas aeruginosa antibiotic resistance. High-throughput DNA sequencing of the P. aeruginosa chromosome revealed the presence of 19 genes encoding structurally related, substrate-specific porins (with 30-45% pairwise amino acid sequence identity) that mediate transmembrane passage of small, water-soluble compounds. The OprD superfamily encompasses the eponymous OprD subfamily, which includes 9 P. aeruginosa proteins that convey basic amino acids and carbapenem antibiotics, and the OpdK subfamily, which includes 11 P. aeruginosa proteins that convey aromatic acids and other small aromatic compounds. Genome sequencing of other gram-negative bacteria has revealed additional members of the OprD and OpdK subfamilies in various organisms, including other pseudomonads. Among the many bacteria in which OprD superfamily members have been identified are P. putida, P. fluorescens Pf-5, P. syringae, and Azotobacter vinelandii, all of which share closely related genes that encode the so-called BenF-like porins. In P. putida, benF is part of an operon involved in benzoate catabolism regulated by benR. Within this operon, benK, benE, and benF genes have been suggested to contribute toward either influx or efflux of benzoate. BLAST analysis of the amino acid sequence of P. fluorescens Pf-5 gene PFL1329 (Uniprot id: http://www.uniprot.org/uniprot/Q4KH25) against P. putida KT2440 strain identified 20 related porins. The top six hits include P. putida KT2440 genes PP1383 (annotated as BenF-like), PP2517 (annotated as BenF-like), and PP3168 (annotated as BenF), which share sequence identities of 76%, 66%, and 44% with PFL1329, respectively. The precise functions of these genes are not yet known. Therefore, we refer to the protein product of gene PFL1329 as PflBenF-like, which reflects its current annotation in the Uniprot database. Crystal structures of OprD and OpdK (vanillate specific porin), both from P. aeruginosa (designated below as PaOprD and PaOpdK, respectively) have been determined. Herein, we report the crystal structure of a putative BenF-like porin from P. fluorescens Pf-5 (PflBenF-like). For the sake of brevity, all subsequent references to the PflBenF-like porin will be made using PflBenF. X-ray crystallography revealed a canonical 18-stranded {beta}-barrel fold that forms a central pore with a diameter of {approx}4.6 E. We describe detailed comparisons of the PflBenF structure with those of PaOprD and PaOpdK.
Nuclear pore complexes (NPCs), responsible for the nucleo-cytoplasmic exchange of proteins and nucleic acids, are dynamic macromolecular assemblies forming an eight-fold symmetric co-axial ring ...structure. Yeast (Saccharomyces cerevisiae) NPCs are made up of at least 456 polypeptide chains of {approx}30 distinct sequences. Many of these components (nucleoporins, Nups) share similar structural motifs and form stable subcomplexes. We have determined a high-resolution crystal structure of the C-terminal domain of yeast Nup133 (ScNup133), a component of the heptameric Nup84 subcomplex. Expression tests yielded ScNup133(944-1157) that produced crystals diffracting to 1.9{angstrom} resolution. ScNup133(944-1157) adopts essentially an all {alpha}-helical fold, with a short two stranded {beta}-sheet at the C-terminus. The 11 {alpha}-helices of ScNup133(944-1157) form a compact fold. In contrast, the previously determined structure of human Nup133(934-1156) bound to a fragment of human Nup107 has its constituent {alpha}-helices are arranged in two globular blocks. These differences may reflect structural divergence among homologous nucleoporins.
PHR PAM (protein associated with Myc)–HIW (Highwire)–RPM-1 (regulator of presynaptic morphology 1) proteins are conserved, large multi-domain E3 ubiquitin ligases with modular architecture. PHR ...proteins presynaptically control synaptic growth and axon guidance and postsynaptically regulate endocytosis of glutamate receptors. Dysfunction of neuronal ubiquitin-mediated proteasomal degradation is implicated in various neurodegenerative diseases. PHR proteins are characterized by the presence of two PHR domains near the N-terminus, which are essential for proper localization and function. Structures of both the first and second PHR domains of
Mus musculus (mouse) Phr1 (MYC binding protein 2, Mycbp2) have been determined, revealing a novel β sandwich fold composed of 11 antiparallel β-strands. Conserved loops decorate the apical side of the first PHR domain (MmPHR1), yielding a distinct conserved surface feature. The surface of the second PHR domain (MmPHR2), in contrast, lacks significant conservation. Importantly, the structure of MmPHR1 provides insights into a loss-of-function mutation, Gly1092
→
Glu, observed in the
Caenorhabditis elegans ortholog RPM-1.
Calpain 3 (C3) is the only muscle‐specific member of the calcium‐dependent protease family. Although neither its physiological function nor its in vivo substrates are known, C3 must be an important ...protein for normal muscle function as mutations in the C3 gene result in limb‐girdle muscular dystrophy type 2A. Previous reports have shown that the ubiquitous calpains (μ and m) proteolyze filamins in nonmuscle cells. This observation suggests that the muscle‐specific filamin C (FLNC) is a good candidate substrate for C3. Binding studies using recombinant proteins establish that recombinant C3 and native FLNC can interact. When these two proteins are translated in vitro and incubated together, C3 cleaves the C‐terminal portion of FLNC. Cleavage is specific as C3 fails to cleave FLNC lacking its C‐terminal hinge and putative dimerization domains. Cotransfection experiments in COS‐7 cells confirm that C3 can cleave the C‐terminus of FLNC in live cells. The C‐terminus of FLNC has been shown to bind the cytoplasmic domains of both δ‐ and γ‐sarcoglycan. Removal of the last 127 amino acids from FLNC, a protein that mimics FLNC after C3 cleavage, abolishes this interaction with the sarcoglycans. These studies confirm that C3 can cleave FLNC in vitro and suggest that FLNC may be an in vivo substrate for C3, functioning to regulate protein–protein interactions with the sarcoglycans. Thus, calpain‐mediated remodeling of cytoskeletal–membrane interactions, such as those that occur during myoblast fusion and muscle repair, may involve regulation of FLNC–sarcoglycan interactions. Muscle Nerve 28: 472–483, 2003
PDF
