Proteolytic processing of big endothelin-3 by the kell blood group protein.

Kell blood group protein shares a consensus sequence (H.E.X.X.H) with a large family of zinc-dependent endopeptidases. Kell has closest homology with neutral endopeptidase 24.11, endothelin converting enzyme-1 (ECE-1), and the PEX gene product that, as a group, comprise the M13 subfamily of mammalian neutral endopeptidases. The proteolytic activity of the M13 members, but not of Kell, has been previously demonstrated. A secreted form of wild-type Kell protein (s-Kell), devoid of the intracellular and transmembrane domains, was expressed in sf9 cells. As a negative control, an inactive mutant Kell protein (E582G) was expressed. As determined by N-terminal amino acid sequencing and mass spectrometry of the cleaved products, wild-type s-Kell, but not the control mutant protein, specifically cleaved big endothelin-3 (ET-3) at Trp(21)-Ile(22), yielding ET-3, and, to a much lesser extent, also cleaved big ET-1 and big ET-2 at Trp(21)-Val(22), yielding ET-1 and ET-2. Enzymatic activity was partially inhibited by phosphoramidon. s-Kell has an acidic pH optimum (pH 6.0 to 6.5). Like the recombinant protein, red blood cells of common Kell phenotype also preferentially process big ET-3, in contrast to Ko (null) cells that do not. These data demonstrate that the Kell blood group protein is a proteolytic enzyme that processes big ET-3, generating ET-3, a potent bioactive peptide with multiple biological roles.     

Combination paclitaxel, carboplatin, and gemcitabine is an active treatment for advanced urothelial cancer.

PURPOSE: To determine the efficacy and toxicity of the drug combination of carboplatin, paclitaxel, and gemcitabine in patients with advanced urothelial carcinoma. PATIENTS AND METHODS: Patients eligible included those with advanced urothelial malignancy of any histology, no previous chemotherapy for metastatic disease, Southwest Oncology Group performance status of 2 or less, serum creatinine levels of 2 mg/dL or less, and adequate bone marrow and hepatic function. Treatment consisted of paclitaxel 200 mg/m2, carboplatin (target area under the curve = 5) on day 1, and gemcitabine 800 mg/m2 on days 1 and 8, repeated every 21 days. RESULTS: Forty-nine patients (44 men and five women) were enrolled; the patients' median age was 63 years, and their median creatinine clearance was 78 mL/min (range, 26 to 165 mL/min). Forty-three patients had transitional cell carcinoma, and six had squamous cell carcinoma or mixed histology. Ten patients had metastases to lymph nodes only, six had locally advanced disease, four had locally recurrent disease, 24 patients had visceral metastases, and five had soft tissue metastases. Twenty-one patients had disease in one site, 16 in two sites, and 12 in three sites. A total of 272 cycles were administered (median, six cycles; range, 1 to 15 cycles). Major toxicities were grade 3 and 4 neutropenia in 17 and 19 patients, respectively; grade 3 and 4 thrombocytopenia in 15 and six patients, respectively; grade 3 and 4 anemia in 10 and two patients, respectively; grade 3 neuropathy in four patients; and diarrhea in two patients. The incidence of febrile neutropenia was 1.4%; no patients died of drug toxicity. Forty-seven of the 49 patients were assessable for response. Fifteen (32%) patients experienced a complete response, and 17 (36%) patients experienced a partial response (32 of 47 patients, 68%; 95% confidence interval, 56.27 to 82.86). Responses were seen in all sites, including 15 (68%) of 22 patients with visceral metastases. The median survival was 14.7 months, with a 1-year survival of 59%. CONCLUSION: Combination paclitaxel, carboplatin, and gemcitabine is active; an encouraging number of patients with advanced urothelial carcinoma treated with this regimen experienced complete remission.     

Microdamage and altered vascularity at the enthesis–bone interface provides an anatomic explanation for bone involvement in the HLA–B27–associated spondylarthritides and allied disorders

Objective

To describe the basis for entheseal‐associated bone disease in the spondylarthritides, by analyzing microanatomic and histopathologic relationships between soft tissue, bone cortex, and adjacent trabeculae.

Methods

Serial sections from 52 entheses were examined; these entheses encompassed small and large insertions in the upper limb (n = 21), lower limb (n = 27), and spine (n = 4) from 60 cadavers. Enthesis microdamage (fissuring) as well as vascular and reparative changes were evaluated. Contact radiographs were used to ascertain the relationship between entheses and the trabecular network.

Results

At virtually all fibrocartilaginous entheses, the deep cortical boundary was extremely thin (typically 50–600 μm) or indistinguishable, and 96% of entheses had small holes in the cortical shell (typically 100–400 μm wide). Such regions were frequent sites of bone formation and renewal (96%) and microdamage (31%); these changes were more common in the lower limb. The presence of blood vessels near holes in the cortical shell was common; in 85% of attachments, blood vessels were present on the soft tissue side of the enthesis. Highly orientated trabeculae were more obvious in the lower limb than the upper limb (59% versus 29%).

Conclusion

The trabecular network supporting the cortical shell is an integral part of the enthesis, transferring load to an extensive skeletal region. In many cases, tendons/ligaments are anchored directly to such networks. This functional integration is associated with microdamage and repair at the hard tissue–soft tissue interface. These findings have implications for understanding bone involvement in SpA and for the SpA concept in general, especially the hypothesis that enthesis–bone architecture may be important in disease initiation.

     

Ultrasound findings of masses of the paratesticular space

Ultrasound is a routine investigation for the assessment of scrotal masses. Many of the detected lesions involve the paratesticular structures. The most common paratesticular masses in clinical practice are epididymal cysts and spermatoceles, but there are a large number of other pathologies that can be encountered and may result in diagnostic uncertainty. This review covers a wide range of the common and the rare, but important, causes of paratesticular masses. The ultrasound findings (both typical and atypical) of these lesions are clarified, and emphasis is given to the features that help to differentiate between them.     

Structure and function of HIV-1 and SIV Tat proteins based on carboxy-terminal truncations, chimeric Tat constructs, and NMR modeling

To further define the structure and function of the domains in HIV-1 and SIV Tat proteins, chimeric Tat cDNA expression constructs were generated with crossover points at the carboxy-terminal end of the cysteine rich domain. The chimera containing the amino-terminal region of SIV and carboxy-terminal region of HIV exhibited activity similar to HIV-1 Tat and SIV Tat on both the HIV-1 and SIV LTRs. In contrast, the reciprocal chimera functioned poorly. As determined by the activity of carboxy-terminal truncation mutants, the region immediately downstream of the basic domain is critical for efficient transactivation by HIV-1 Tat, but not SIV Tat protein. In this report, we present a model for Tat domains based on NMR data and the known functional properties of Tat protein. According to our modeling two sites for protein :protein interactions are present in HIV-1 and SIV Tat proteins. Site I, which is presumably involved in cyclin T binding, is similar in both HIV-1 and SIV Tat proteins as well as in Tat chimeras. Site II, however appears structurally different in HIV-1 and SIV Tat models, although in both cases is comprised of amino and carboxy-terminal residues. Differences in Site II may thus account for the differential activities of HIV-1 and SIV Tat carboxy-terminal truncations. Site II in the poorly active chimera differs significantly from that found in HIV-1 and SIV Tat proteins. The two site structural model presented here may have important implications for the role of Tat in HIV pathogenesis and may provide insights for the design of Tat vaccines and targeted therapeutics.     

Vectorcardiographic QRS area as a predictor of response to cardiac resynchronization therapy

Cardiac resynchronization therapy(CRT)is a good treatment for heart failure accompanied by ventricular conduction abnormalities.Current ECG criteria in international guidelines seem to be suboptimal to select heart failure patients for CRT.The criteria QRS duration and left bundle branch block(LBBB)QRS morphology insufficiently detect left ventricular activation delay,which is required for benefit from CRT.Additionally,there are various definitions for LBBB,in which each one has a different association with CRT benefit and is prone to subjective interpretation.Recent studies have shown that the objectively measured vectorcardiographic QRS area identifies left ventricular activation delay with higher accuracy than any of the current ECG criteria.Indeed,various studies have consistently shown that a high QRS area prior to CRT predicts both echocardiographic and clinical improvement after CRT.The beneficial relation of QRS area with CRT-outcome was largely independent from QRS morphology,QRS duration,and patient characteristics known to affect CRT-outcome including ischemic etiology and sex.On top of QRS area prior to CRT,the reduction in QRS area after CRT further improves benefit.QRS area is easily obtainable from a standard 12-lead ECG though it currently requires off-line analysis.Clinical applicability will be significantly improved when QRS area is automatically determined by ECG equipment.     

Syncytiotrophoblast Derived Extracellular Vesicles in Relation to Preeclampsia

The syncytiotrophoblast, a fused single-cell layer between mother and fetus, constitutively releases extracellular vesicles (STBEV) directly into the maternal c...     

Combined modality therapy for cutaneous T-cell lymphoma

Background: Cutaneous T-cell lymphoma (CTCL) may respond to many therapies, but long-term disease-free survival is uncommon. Patients with advanced disease have a median survival of approximately 3 years.Objective: Our purpose was to combine known effective agents sequentially to determine whether we could achieve remission in more patients or for longer duration.Methods: Patients with mycosis fungoides (n = 23) or Sézary syndrome (n = 5) were treated with 4 months of recombinant interferon alfa together with isotretinoin, followed by total skin electron beam therapy alone (for stage I to II disease) or preceded by chemotherapy (for stage III to IV disease). Maintenance therapy consisted of interferon for 1 year and topical nitrogen mustard for 2 years.Results: Twenty-eight patients were treated. The overall response rate (complete and partial remissions) was 82%. Although the median duration of remission was 5 months in patients with stage III to IV disease, two patients remain in complete remission at 39+ and 46+ months. In patients with stage I to II disease the median duration of remission has not been reached at a median follow-up of 18 months. Five patients, all with stage III to IV disease, have died. Overall, the regimen was well tolerated with one treatment-related death from neutropenic sepsis.Conclusion: Combined modality therapy may be effective for the treatment of CTCL with similar response rates to other current therapies.