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The elastic modular changes of the rat uterine cervix under different physiological conditions.

In this paper, the elastic moduli of the rat uterine cervix were measured under different physiological conditions. It was found that the moduli significantly changed with the sex cycle, being higher in diestrus than in estrus, and highest in early pregnancy. The results suggest that active changes occur in the function of the uterine cervix under the modulation of hormones.

Animals↗

Modular extension of the ACR-NEMA DICOM standard to support new diagnostic imaging modalities and services.

The American College of Radiology-National Electrical Manufacturers Association (ACR-NEMA) Standard for Digital Imaging and Communications in Medicine (DICOM) (NEMA PS3-1993, DICOM) enables interconnection of imaging equipment and exchange of diagnostic images over standard networks. The widespread adoption of DICOM by industry and the benefits of standardized image management have attracted international attention. Other medical specialties, dentistry, and veterinary medicine have indicated strong interest in extending the DICOM Standard to support nonradiological image modalities. Parts 1 through 9 of DICOM were published in 1992 and 1993. Additional features developed in response to requests from the user community are being added in DICOM Supplements. The ACR, NEMA, and committees from other medical specialties working under the coordination of the American National Standards Institute Healthcare Informatics Standards Planning Panel Message Standards Developers Subcommittee Joint Working Group for Diagnostic Image Communication have defined new image object classes to support X-Ray Angiography, Radio-Fluoroscopy, Positron Emission Tomography, Endoscopy, and Light Microscopy. ACR-NEMA has also developed new service classes for Storage Commitment and Worklist Management. In joint work with the standards development committee of the Japanese Industries for Radiation Apparatus and the Japanese Medical Information System Development Center, ACR-NEMA has developed specifications for multibyte character set support and for a DICOM file format for transportable media. Other work is in progress. New DICOM features have provided and can continue to provide significant new functionality for digital image management systems. The demonstrated capability of efficient extension of the base standard is evidence of the effectiveness of the object oriented strategy of DICOM.

Diagnostic Imaging↗

The modular nature of apoptotic signaling proteins.

Apoptosis, initiated by a variety of stimuli, is a physiological process that engages a well-ordered signaling cascade, eventually leading to the controlled death of the cell. The most extensively studied apoptotic stimulus is the binding of death receptors related to CD95 (Fas/Apo1) by their respective ligands. During the last years, a considerable number of proteins have been identified which act together in the receptor-proximal part of the signaling pathway. Based on localized regions of sequence similarity, it has been predicted that these proteins consist of several independently folding domains. In several cases these predictions have been confirmed by structural studies; in other cases they are at least supported by experimental data. This review focuses on the three most widespread domain families found in the apoptotic signaling proteins: the death domain, the death effector domain and the caspase recruitment domain. The recently discovered analogies between these domains, both in structure and in function, have shed some light on the overall architecture of the pathway leading from death receptor ligation to the activation of caspases and eventually to the apoptotic phenotype.

Adaptor Proteins, Signal Transducing↗

[Marburg modular prone positioning system (MBS) for positioning therapy].

Despite the many benefits of prone positioning in critically ill patients with respiratory failure and ARDS in the ICU, its technical problems have not yet been adequately resolved. Different approaches with special beds for prone positioning do exist, but these devices are difficult to handle, often not available and involve high costs. With this in mind, we developed an easy handling prone positioning system (MBS) that requires no special beds and runs at low cost. The MBS is a cost-effective device, yielding many benefits for prone positioning in critically ill patients with severe athelectasis and ARDS.

Beds↗

Possible roles for a non-modular, thermostable and proteinase-resistant cellulase from the mesophilic aerobic soil bacterium Cellvibrio mixtus.

The widespread presence of cellulose-binding domains in cellulases from aerobic bacteria and fungi suggests the existence of a strong selective pressure for the retention of these non-catalytic modules. The complete nucleotide sequence of the cellulase gene, celA, from the aerobic soil bacterium Cellvibrio mixtus, was determined. It revealed an open reading frame of 1089 bp that encoded a polypeptide, defined as cellulase A (CelA), of M(r) 41,548. CelA displayed features characteristic of an endo-beta-1,4-glucanase, rapidly decreasing the viscosity of the substrate while releasing only moderate amounts of reducing sugar. Deletion studies in celA revealed that removal of 78 nucleotides from the 5' end or 75 from the 3' end of the gene led to the complete loss of cellulase activity of the encoded polypeptides. The deduced primary structure of CelA revealed an N-terminal signal peptide followed by a region that exhibited significant identity with the catalytic domains of cellulases belonging to glycosyl hydrolase family 5. These data suggest that CelA is a single-domain endoglucanase with no distinct non-catalytic cellulose-binding domain. Analysis of the biochemical properties of CelA revealed that the enzyme hydrolyses a range of soluble cellulosic substrates, but was inactive against Avicel, xylan or any other hemicellulose. CelA was resistant to proteolytic inactivation by pancreatic proteinases and surprisingly, in view of its mesophylic origin, was shown to be thermostable. The significance of these findings in relation to the role of single-domain cellulases in plant cell wall hydrolysis by aerobic microorganisms is discussed.

Amino Acid Sequence↗

The crescent sign: dissociation of the polyethylene liner from a modular acetabular component in total hip arthroplasty.

OBJECTIVE: To study whether there was a common pattern of clinical symptoms, signs and radiographic features for the dissociation of the polyethylene liner from an acetabular component and to postulate reasons for these features. DESIGN AND PATIENTS: Retrospective study of notes and radiographs of cases of revision hip arthroplasty for polyethylene liner dissociation of the cementless Harris-Galante I porous-coated acetabular component (Zimmer Inc, Warsaw, IN) at the Avon Orthopaedic Centre, Bristol, UK and St. Mary's Hospital, Bristol, UK between 1995 and 2004. Patients were contacted to confirm preoperative symptoms. RESULTS: Nine cases of late polyethylene liner dissociation of this prosthesis have been revised in these institutions. All patients presented with a reduction in mobility, groin pain and limp. Eight patients reported an audible noise on hip movement. In all cases, radiographs showed radiolucency medial to the femoral neck in association with an eccentrically placed femoral head showing contact with the acetabular metal shell, which we have termed the "crescent sign." CONCLUSIONS: There is a typical clinical presentation in this study. The diagnosis can be made from a single anteroposterior pelvic radiograph without the need for previous films for comparison, or the need for arthrography. Clinicians should look specifically for the crescent sign when an eccentrically placed femoral head has been noted, in order to differentiate the more unusual diagnosis of dissociation from that of polyethylene wear. Early revision surgery can prevent damage to the femoral head and metal acetabular shell, thus reducing the complexity of revision surgery.

Adult↗

Cementless modular hip revision arthroplasty using the MRP Titan Revision Stem: outcome of 79 hips after an average of 4 years' follow-up.

INTRODUCTION: As primary total hip replacements (THRs) become more common in older patients and younger, physically active patients, the number of revision arthroplasties will also increase. Femoral bone loss, joint instability and possible infections are a challenge for a surgeon performing revision arthroplasty of the hip. The severe proximal femoral bone loss indicates the use of revision stems with a distal fixation. MATERIALS AND METHODS: In this study the clinical and radiological outcomes of 79 cementless stem revisions using the MRP Titan Revision Stem with an average follow-up time of 4 years were prospectively examined. RESULTS: The Harris Hip Score improved from preoperative 50.8+/-25.2 to postoperative 86.8+/-13.2. In all cases healing of bony defects could be found. For stem diameters larger than 17 mm, atrophy of the proximal femur and non-progressive radiolucent lines in zones 1 and 7 according to Gruen were detected. No disadvantages or complications of the Morse taper junctions were observed, and no osteolysis was detected in this region. Primary stable fixation was achieved in all but two cases. Three cases were revised again due to periprosthetic fracture (1) and persisting infection (2). CONCLUSION: Given the encouraging results with the MRP Titan Revision Stem, the principle of uncemented diaphyseal fixation appears to solve most of the technical problems in cases of significant bone loss and obviously offers good preconditions for bony restoration.

Aged↗

Immunolocalization of LeAGP-1, a modular arabinogalactan-protein, reveals its developmentally regulated expression in tomato.

Arabinogalactan-proteins (AGPs) are highly glycosylated cell surface proteins that are thought to function in plant growth and development. The developmentally regulated expression of LeAGP-1, a novel and major AGP in tomato, was examined in different organs and tissues of tomato (Lycopersicon esculentum Mill. cv. UC82B) plants with an anti-peptide antibody (i.e. the PAP antibody) directed specifically against the lysine-rich subdomain of the LeAGP-1 core protein. During cell differentiation in tomato plants, LeAGP-1 was associated with cell wall thickening and lignification of particular cell types. Specifically, LeAGP-1 was detected in secondary wall thickenings of maturing metaxylem and secondary xylem tracheary elements in roots and stems, and in thickened cell walls of phloem sieve elements. However, LeAGP-1 was also present in thin-walled, cortical parenchyma cells of seedling roots as well as thick-walled collenchyma cells in young stems, both of which are not lignified. Based on these observed patterns, possible roles for LeAGP-1 in plant growth and development are discussed.

Blotting, Western↗

Dissection of the wheat transcription factor HBP-1a(17) reveals a modular structure for the activation domain.

The wheat bZIP protein HBP-1a(17) is a putative transcription factor regulating histone gene expression. To delineate the functional domain(s) of this factor, we made a series of effector constructs expressing fusion proteins, in which various portions of HBP-1a(17) are fused to the DNA-binding domain of the yeast transcriptional activator GAL4, in plant cells. When the beta-glucuronidase (GUS) reporter gene, driven by the wheat histone H3 core promoter harboring the GAL4-binding sequence, was co-transfected with such effector genes into tobacco protoplasts, several portions of HBP-1a(17) influenced reporter gene expression. The N-terminal one-third of HBP-1a(17), termed the P region (residues 1-118) due to its Pro content, did not activate the reporter gene, in contrast to the corresponding Pro-rich region of Arabidopsis GBF1 (residues 1-110), which functions as an activation domain. When the P region was divided into two, however, both its N-terminal (1-56; termed NP) and C-terminal (58-118; termed PC) halves were able to enhance expression of the reporter gene. When the NP region was further divided into NP(5-30) and NP(30-56), both regions still retained activating ability. These results suggest that the P region of HBP-1a(17) is composed of several modules each having activating function, and modification and/or conformational changes of the P region might influence its function.

Arabidopsis↗

Desulfoferrodoxin: a modular protein.

The gene encoding the non-heme iron-containing desulfoferrodoxin from Desulfovibrio vulgaris was cloned in two fragments in order to obtain polypeptides corresponding to the N- and C-terminal domains observed in the tertiary structure. These fragments were expressed in Escherichia coli, purified to homogeneity and biochemically and spectroscopically characterized. Both recombinant fragments behaved as independent metal-binding domains. The N-terminal fragment exhibited properties similar to desulforedoxin, as expected by the presence of a Fe(S-Cys)4 metal binding motif. The C-terminal fragment, which accommodates a Fe(Nepsilon-His)3(Ndelta-His)(S-Cys) center, was shown to have properties similar to neelaredoxin, except for the reaction with superoxide. The activities of desulfoferrodoxin and of the expressed C-terminal fragment were tested with superoxide in the presence and absence of cytochrome c. The results are consistent with superoxide reductase activity and a possible explanation for the low superoxide consumption in the superoxide dismutase activity assays is proposed.

Amino Acid Sequence↗

Sciatic nerve palsy after cementless total hip arthroplasty. Treatment by modular neck and calcar shortening: a case report.

This is a case report of sciatic nerve palsy after total hip arthroplasty. Although the patient's symptoms became worse postoperatively, full recovery occurred after shortening of the calcar and femoral neck length. For acute sciatic nerve palsy patients with worsening of symptoms in the postoperative course in spite of hip and knee flexion, reexposure for early recognition of the sciatic nerve condition and reoperation by shortening the femoral neck may be an option.

Arthroplasty, Replacement, Hip↗

The value of intraoperative intravascular ultrasound for determining stent graft size (excluding abdominal aortic aneurysm) with a modular system.

Since the introduction of endovascular stent grafts at our institution we have used intraoperative intravascular ultrasound (IVUS) to definitively determine stent graft size. In this study, expected stent graft size, based on preoperative helical CT scan measurements, was compared with the actual final size, based on intraoperative IVUS measurements. Between December 1996 and January 1998, 54 patients were treated with an AneuRxTM bifurcated stent graft. Preoperatively all patients underwent angiography and helical CT scanning. Expected stent graft size was determined according to these measurements. The final stent graft size was based on IVUS measurements acquired during the procedure. Differences in expected and final size were compared and follow-up endoleaks were also noted. Differences in diameter measurements between CT and IVUS were compared using the paired Student's t-test. Differences in expected and chosen stent graft length were compared using the McNemar's test for paired proportions of binomial outcomes. Our results showed that helical CT scanning overestimates diameter and underestimates length. This underestimation of length is explained by the tortuosity of the aorta and iliac arteries while using axial slices of the CT scan. The last-minute corrections based on the intraoperative IVUS measurements did not result in a high incidence of endoleaks at fixation zones. In our opinion, the possibility of making final corrections in the choice of diameter or length of the stent graft is the additional value of intraoperative IVUS.

Aortic Aneurysm, Abdominal↗

Poly-Ig tandems from I-band titin share extended domain arrangements irrespective of the distinct features of their modular constituents.

The cellular function of the giant protein titin in striated muscle is a major focus of scientific attention. Particularly, its role in passive mechanics has been extensively investigated. In strong contrast, the structural details of this filament are very poorly understood. To date, only a handful of atomic models from single domain components have become available and data on poly-constructs are limited to scarce SAXS analyses. In this study, we examine the molecular parameters of poly-Ig tandems from I-band titin relevant to muscle elasticity. We revisit conservation patterns in domain and linker sequences of I-band modules and interpret these in the light of available atomic structures of Ig domains from muscle proteins. The emphasis is placed on features expected to affect inter-domain arrangements. We examine the overall conformation of a 6Ig fragment, I65-I70, from the skeletal I-band of soleus titin using SAXS and electron microscopy approaches. The possible effect of highly conserved glutamate groups at the linkers as well as the ionic strength of the medium on the overall molecular parameters of this sample is investigated. Our findings indicate that poly-Ig tandems from I-band titin tend to adopt extended arrangements with low or moderate intrinsic flexibility, independently of the specific features of linkers or component Ig domains across constitutively- and differentially-expressed tandems. Linkers do not appear to operate as free hinges so that lateral association of Ig domains must occur infrequently in samples in solution, even that inter-domain sequences of 4-5 residues length would well accommodate such geometry. It can be expected that this principle is generally applicable to all Ig-tandems from I-band titin.

Amino Acid Motifs↗

Modular headache theory: a new approach.

Many people experience headaches that do not fulfill the International Headache Society's criteria for a specific headache disorder, yet behave biologically like that disorder. Others fulfill criteria for one headache disorder but have features of another. To explain these observations, we propose that groups of neurons, called modules, become activated to produce each symptom of a primary headache disorder, and that each module is linked to other modules that together produce an individual's headache. Headaches develop phenotypic stability through a process referred to as learned stereotypy. This theory has implications for the classification, research, and treatment of primary and secondary headache patients.

Headache↗