Simplified urethral score system for predicting complex anterior urethroplasty.

OBJECTIVE: To assess U-score individual values as urethral complex surgery predictors. METHODS: Cross-sectional study including patients who received anterior urethroplasty from 2011 to 2019. U-score (etiology (1-2 points), number of strictures (1-2 points), anatomic location (1-2 points) and length (1-3 points)) was measured individually and globally. Surgical complexity was defined as low (anastomotic, buccal mucosal graft, and augmented anterior urethroplasty), and high complexity (double buccal mucosal graft, flap, and graft/flap combination). U-score components were included as complex surgery predictor and as main variable with individual probability values estimations and comparisons. Risk complex surgery probability groups were established. RESULTS: 654 patients were included. Mean age was 57.2 years. Low complexity surgery was performed in 464 patients (259 anastomotic, 144 graft, 61 augmented anterior urethroplasty) and high complexity was done in 190 (53 double buccal mucosa graft, 27 flap, 110 graft/flap comb.). In multivariate analysis length, number of strictures and location were predictors of complexity. Introducing U-Score as only variable in univariate model predicted an OR 8.52 (95%CI 6.1-11). Simplified U-score grouping set obtained by complex probability was: low risk (4-5 points), medium risk (6 points) and high risk of complexity (7-9 points) Predicted risk of complex surgery probability (95%CI) for low, median and high risk group were 1.6 (0-2.9), 19.1 (13.8-25.9) and 77.9 (61.6-88.7), respectively. CONCLUSIONS: U-score can be used as a tool to predict complex urethral surgery. We present a simplified U-score risk tool to assess individual complex anterior urethroplasty probability.

Diatom frustules decorated with zinc oxide nanoparticles for enhanced optical properties.

Zinc oxide (ZnO) nanoparticles were synthesized on diatomite (DE) surface by a low temperature sol gel technique, starting from zinc acetate dihydrate (Zn(CH3COO)2 · 2H2O) solution in water/ethyl alcohol, in presence of triethanolamine (TEA) with functions of Zn2+ chelating agent, catalyst and mediator of nanoparticle growth on DE surface. Microstructural features were investigated by field emission scanning electron microscopy and x-ray diffraction. ZnO crystalline nanoparticles, well distributed both on the surface and into the porous architecture of diatomite, were obtained just after the synthesis carried out at 80 °C without the need of calcination treatments. The optical properties of ZnO/DE hybrid powders were measured for the first time by means of photoacoustic spectroscopy (PAS). A new method to retrieve both the optical absorption and scattering coefficients from PAS is here discussed for powder aggregates. The fingerprint of the zinc oxide nanoparticles has been highlighted in the Mie scattering resonance in the UV-Vis range, and in the enhancement of the optical absorption with respect to diatomite.

Influence of sternal size and inadvertent paramedian sternotomy on stability of the closure site: a clinical and mechanical study.

BACKGROUND: The influence of sternal size and of inadvertent paramedian sternotomy on stability of the closure site is not well defined. METHODS: Data on 171 consecutive patients undergoing cardiac surgery through a midline sternotomy were prospectively collected. Intraoperative measurements of sternal dimension included thickness and width at the manubrium, the third and fifth intercostal spaces; paramedian sternotomy was defined as width of one side of the sternum equaling 75% or more of the entire width, at any of the three levels. The chest was closed with simple peristernal steel wires and inspected to detect deep wound infection and/or instability for 3 postoperative months. The sternal factors and several patient/surgery-related factors were included in a multivariate analysis model to identify factors affecting stability. An electromechanical traction test was conducted on 6 rewired sternal models after midline or paramedian sternotomy and separation data were analyzed. RESULTS: Chest instability was detected in 12 (7%) patients and wound infection in 2 (1.2%). Patient weight (P = .03), depressed left ventricular function (P = .04), sternum thickness (indexed to body weight, P = .03), and paramedian sternotomy (P = .0001) were risk factors of postoperative instability; paramedian sternotomy was the only independent predictor (P = .001). The electromechanical test showed more lateral displacement of the two rewired sternal halves after paramedian than midline sternotomy (P = .002); accordingly, load at fracture point was lower after paramedian sternotomy (220 +/- 20 N vs 545 +/- 25 N, P = 0.001). CONCLUSIONS: Inadvertent paramedian sternomoty strongly affects postoperative chest wound stability independently from sternal size, requiring prompt reinforcement of chest closure.

Biomechanics of anterior cruciate ligament reconstruction using twisted doubled hamstring tendons.

We studied the biomechanical properties of a twisted doubled semitendinosus and gracilis graft. We applied an un-axial load in order to reproduce the kinematics of a reconstructed anterior cruciate ligament (ACL). A modified cryo-jaw clamp system was used to minimize soft tissue slippage. The lower grip, after fixation of the free ends of the tendons, was rotated 45 degrees, translated 1 cm, and bent 40 degrees, simulating a knee sprain. The graft was tested to failure using a servohydraulic machine. The specimen from one knee of seven unembalmed cadavers was assigned to the untwisted (parallel) bundles group, while its pair was assigned to the twisted group. For the parallel bundles group, the mean maximum load was 1,709.3+/-581.9 N, for the twisted group 2,428.3+/-475.4 N (P<0.05). The mean stiffness was respectively 213.6+/-72.4 N/mm and 310.3+/-97.3 N/mm (P=0.08). Although caution should be used in extrapolating the results to clinical estimates of the strength of hamstring grafts, the results of the present study could justify the use of twisted semitendinosus and gracilis bundles in ACL reconstruction.

Implant placement in large edentulous ridges expanded by GBR using a bioresorbable collagen membrane.

The purpose of this study is to evaluate the possibility of expanding an edentulous ridge spanning two or more teeth by a two-step technique with bioresorbable collagen membranes. Sixteen healthy patients were treated, four in the mandible and 12 in the maxilla. The borderline of the crest width was less than or equal to 4 mm. In each patient only one ridge augmentation was performed. After elevation of a full-thickness flap, a surgical stent was positioned to identify the area of ideal implant positioning. The width of the crest at the location of the surgical stent was measured at the time of GBR procedure and 7 to 12 months later during implant insertion. Native collagen sponges were placed buccally and lingually, and a collagen membrane was shaped and trimmed to completely cover the edentulous ridge. The flaps were sutured to achieve primary closure. Antibiotic and clorhexidine mouthrinse were prescribed, and the patients were recalled every 2 weeks. At implant placement, the mean increase in the size of the crest was 2.49 mm (+/- 1.61 mm). In 12 out of 16 patients (75%) it was possible to insert 27 implants according to the prosthetic need established previously. All implants were successfully loaded, and in the four cases where no appreciable results were obtained, no clinical complications or loss of hard and soft tissue were observed.

Global asymptotic stability of bone remodeling theories: a new approach based on non-linear dynamical systems analysis.

Mathematical tools for the analysis of nonlinear dynamical systems are applied to the study of stability of bone remodeling theories. As a practical application, the same problem studied by Harrigan and Hamilton (1992) and Cowin et al. (1994b) is analysed using these tools, and their findings on the necessary and sufficient conditions to ensure local asymptotic stability are easily confirmed. Using a general approach based on Lyapunov's method the same condition has been found to be necessary and sufficient also for the global asymptotic stability, thus confirming a result obtained by Harrigan and Hamilton (1994) by variational methods applied to finite-element models. The proof is based on the discretization of the spatial domain but the results for the continuum can be easily extrapolated.

Guided tissue regeneration employing a collagen membrane in a human periodontal bone defect: a histologic evaluation.

The purpose of this study is to confirm histologically whether a new attachment can be obtained around a tooth by guided tissue regeneration using bioresorbable barrier. The test tooth was a maxillary molar with an intrabony pocket. At reentry 5 months after periodontal surgery, a hard, whitish, blood-free tissue was found to fill the original defect. Histologic analysis revealed presence of new bone, cementum, and periodontal ligament compatible with the expected histologic result of guided tissue regeneration techniques with barrier membrane.

Yersinia pseudotuberculosis in Italy. Attempted recovery from 37,666 samples.

From 1981 to 1991, 37,666 human, animal, food and environmental samples were cultured for Yersinia pseudotuberculosis using direct plating methods and/or cold enhancement techniques. Despite an intensive surveillance and adequate culture methods, Y. pseudotuberculosis was isolated from stools of 0.05% (5/9,720) of patients with acute enteritis, and alimentary tracts of 0.1% (10/6,849) of apparently healthy animals. No Y. pseudotuberculosis strains were recovered from stools of 4,726 health controls nor from the appendices (656), mesenteric lymph nodes (84), and stools (421) of 656 patients operated for suspected appendicitis. Of the 10,842 food and 4,368 environmental samples, none yielded positive cultures for Y. pseudotuberculosis.

Characteristics of the active oxygen in covalent binding of the pesticide methoxychlor to hepatic microsomal proteins.

This study examined the characteristics of the active oxygen species involved in generation of the reactive intermediate of methoxychlor which covalently binds to liver microsomal proteins. The possibility that the active oxygen participating in the above reaction is the superoxide anion (O2-) or a species generated from O2- was examined with the help of superoxide dismutase (SOD) and with an SOD-mimetic agent, CuDIPS [Cu2+(3,5-diisopropylsalicylic acid)2]. It was observed that, whereas CuDIPS inhibited covalent binding of methoxychlor metabolite(s), SOD did not. However, ZnDIPS [Zn2+(3,5-diisopropylsalicylic acid)2], which exhibits no SOD-mimetic activity, did not inhibit covalent binding. Furthermore, both CuDIPS and ZnDIPS had little or no effect on the formation of demethylated (polar) metabolites of methoxychlor, demonstrating that the inhibition of covalent binding by CuDIPS was not merely due to a general inhibition of the hepatic monooxygenase system. These findings suggested that O2- was involved in covalent binding, but was not accessible to SOD. Additional support for O2- involvement stems from the observation that alpha-tocopheryl acid succinate markedly inhibited covalent binding of methoxychlor. The possibility that hydrogen peroxide (H2O2) was involved in covalent binding of methoxychlor appears unlikely. Catalase had no effect on covalent binding when NADPH was the cofactor, and the use of H2O2 in place of NADPH did not yield covalent binding. Certain scavengers of hydroxyl radical (ethanol, t-butanol and benzoate) inhibited, and other known scavengers (DMSO and mannitol) did not inhibit, covalent binding. EDTA stimulated binding, desferal (desferrioxamine) exhibited no effect on binding, and diethylenetriaminepentaacetic acid (DETAPAC) inhibited binding. A possible explanation for this observation is that the Fe2+ needed for generation of X OH is much more easily obtained from Fe3+-EDTA than from Fe3+-desferal, which resists reduction. The inhibitory effect by DETAPAC may be due to chelation of another metal which is needed for the reaction. Lastly, certain scavengers of singlet oxygen inhibited covalent binding with little effect on the formation of polar metabolites of methoxychlor. In conclusion, these studies support the involvement of X OH and singlet oxygen, possibly derived from O2-, in the formation of the reactive methoxychlor intermediate.(ABSTRACT TRUNCATED AT 400 WORDS)

Determination of vaccine-induced and naturally acquired class-specific mumps antibodies by two indirect enzyme-linked immunosorbent assays.

Paired sera from 46 vaccinees and 22 patients with clinically typical or atypical parotitis were tested for class-specific mumps antibodies by two different indirect enzyme-linked immunosorbent assay (ELISA) procedures. Both ELISAs appeared suitable, specific and more sensitive than neutralization (NT) and complement-fixation (CF). However, the macro-ELISA (M-ELISA) method, using beads as antigen-coated solid phase, showed a higher sensitivity than micro-ELISA (m-ELISA), performed on microplates. Diagnostic rises in mumps IgG antibodies and mumps IgA antibodies were detected more frequently by M-ELISA, mostly in post-vaccination sera. In addition, higher mean OD values of mumps IgG, IgA and IgM antibodies were generally found by M-ELISA. Nevertheless, m-ELISA appeared more convenient for evaluating class-specific mumps antibodies in large-scale studies, since the procedure is simpler, more rapid and less expensive than that of M-ELISA. Conversely, M-ELISA may be considered the test of choice for detecting low class-specific antibody levels. However, the determination of class-specific mumps antibodies appeared as an essential tool for evaluating vaccine-induced or naturally acquired mumps immunity.