Nerve grafts prevent paraplegic pressure ulcers

We present an optimistic neural solution to the depressing challenge of decubitus pressure ulcers in the paraplegic patient. This is a limited study of two paraplegic men followed for several years. Sural nerve grafts, performed end-to-side, successfully bridged the sciatic nerve to intercostal nerves with surprising benefits for both men.

Assessment of effective doses from radon levels for tour guides at several galleries of Santana Cave, Southern Brazil, with CR-39 detectors: preliminary results

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Congenital deformity of the paw in a captive tiger: case report

Background: The aim of this report was to describe the clinical signs, diagnostic approach, treatment and outcome in the case of a tiger with a deformity of the paw.Case presentation: A 1.5-year-old tiger (Panthera tigris) was presented with lameness of the left thoracic limb. A deformity involving the first and second metacarpal bones, and a soft tissue separation between the second and third metacarpal bones of the left front paw were observed. The second digit constantly struck the ground during locomotion. Based on the physical and radiographic evaluations, a diagnosis of ectrodactyly was made. A soft tissue reconstruction of the cleft with excision of both the second digit and distal portion of the second metacarpal bone was performed. Marked improvement of the locomotion was observed after surgical treatment, although the tiger showed a low degree of lameness probably associated with the discrepancy in length between the thoracic limbs.Conclusion: This report shows a rare deformity in an exotic feline that it is compatible to ectrodactyly. Reconstructive surgery of the cleft resulted in significant improvement of limb function.

New treatment for frontal sinus hypertrophy

A new treatment of frontal sinus hypertrophy is described. The anterior wall is removed, inverted, and attached again. The resulting depression is filled with bone dust. Details are discussed, and a case is presented.

Problems related to the employment of thin uranium films as neutron dosimeters

Thin uranium films built on muscovite mica basis and obsidian samples having known ages were irradiated with thermal neutrons at the IPEN/CNEN reactor, São Paulo. Comparing thin film performance with the obsidian one, it was observed that the latter feel a greater neutron fluence. Nominal fluences at the used facility are in agreement with the results obtained analysing the obsidian samples. A probable hypothesis to explain this disagreement, namely, the uranium loss from the thin films, was ruled out. © 1995.

Calibration of therapeutic ultrasound equipment

Temporal and spatial acoustic intensity (SATA) of therapeutic ultrasound (US) equipment should be monitored periodically. In order to evaluate the conditions of US equipment in use in the city of Piracicaba-Sao Paulo, Brazil, 31 machines - representing all Brazilian manufacturers - were analysed under continuous and pulsed conditions at a frequency of 1 MHz. Data about temporal and spatial acoustic intensity were collected and the use of equipment was surveyed. Intensities of 0.1, 0.2, 0.5, 0.8, 1.0, 1.5, 2.0, 2.5 and 3.0 Wcm -2, indicated on the equipment panel were analysed using a previously calibrated digital radiation pressure scale, model UPM-DT-1 (Ohmic Instruments Co). The acoustic intensity (I) results were expressed as superior and inferior quartile ranges for transducers with metal surfaces of 9 cm 2 and an effective radiation area (ERA) Of 4 cm 2. The results under continuous conditions were: I 0.1 = -20.0% and -96%. I 0.2 = -3.1% and -83.7%. I 0.5 = -35.0% and -86.5%. I 0.8 = -37.5% and -71.0%. I 2.5 = -49.0% and -69.5%. I 3.0 = -58.1% and -77.6%. For pulsed conditions, intensities were: I 0.1 = -40.0% and -86.2%. I 1.0 = -50.0% and -86.5%. I 1.5 = -62.5% and -82.5%. I 2.0 = -62.5% and -81.6%. I 2.5 = -64.7% and -88.8%. I 3.0 = -87.1% and -94.8%. In reply to the questionnaire drawn up to check the conditions of use of equipment, all users reported the use of hydrosoluble gel as a coupling medium and none had carried out previous calibrations. Most users used intensities in the range of 0.4. to 1.0 Wcm -2 and used machines for 300 to 400 minutes per week. The majority of machines had been bought during the previous seven years and weekly use ranged from less than 100 minutes to 700 minutes (11 hours 40 minutes). Findings confirm previous observations of discrepancy between the intensity indicated on the equipment panel and that emitted by the transducer and highlight the necessity for periodic evaluations of US equipment.

TL, EPR and optical absorption studies on natural alexandrite compared to natural chrysoberyl

The TL, optical absorption (OA) and EPR properties of natural Brazilian alexandrite and chrysoberyl have been investigated. The TL measurements for natural alexandrite show five peaks between 100 and 450°C, with their emission spectrum having 370 and/or 570 nm components. The intensity of the 320°C TL peak was found to be enhanced with pre-annealing treatment, more prominently above 600°C. The OA and EPR measurements showed that this kind of heat treatment induces the Fe2→ Fe3+ conversion in the natural sample. Chrysoberyl samples exhibited the TL peaks at the same temperatures as alexandrite samples, but the glow curves were more than 200 times less intense than alexandrite ones.

Variation of Laser Intensity on the Healing of Cutaneous Wounds

Tissue repair is an integration of dynamic interactive processes that involves soluble mediators, blood components, production of extra-cellular matrix and mesenchymal cells. Many studies involving the use of LLLT shows that the healing process is favored by such therapy. The aim of this work was to evaluate, through histological analysis, the tissue effects of cutaneous wounds submitted to different intensities and a same irradiation dose with lasers in λ670 or λ685nm. Eighteen animals were divided in two experimental groups according to wavelength used (λ670 or λ685nm). Each one of these groups was divided still in three subgroups of three animals each, related to the intensity of applied irradiation (2, 15 or 25mW). Twelve animals acted as untreated controls and were not irradiated. The irradiation was carried out during seven days. The animals were sacrificed eight days after surgery. The specimens were removed, kept in 4% formaldehyde for 24 hours, routinely prepared to wax, stained with H&E and analyzed under light microscopy. The histological characteristics observed, so much in the irradiated animals, as in the control, they are indicative of a substitution repair process, however, the LLLT modulatory positive effect was observed, in the healing process, mainly associate to the use of the shorter wavelength and low power. The results of the present study indicate that LLLT improves cutaneous wound repair and best results are achieved when higher potencies associated to short wavelengths or lower potencies associated to higher wavelengths are used.

A comparison of human and porcine acellular dermal tissues in the subcutaneous space of a rat model

The study compared the host response to a human and a porcine acellular dermal tissue implanted in the subcutaneous space of a rat model. The human and porcine acellular grafts were surgically implanted in the subcutaneous tissue of rats (5 rats/group) and the materials were evaluated at 7, 15, 30, 60 and 180 postoperative days (PO). The histological immune response was quantified using a digital image analysis system, which evaluated the number of vessels present in the implants and in the surrounding soft tissue, the area of inflammatory cell infiltration in the grafts, the width of the capsular formation present around the tissues and the area of implants absorbed. The data were submitted to statistical analysis. Light microscopy showed mononuclear cellular infiltration, the presence of a capsular formation surrounding the grafts and the presence of vacuolar structures (optically empty spaces) inside the implants. The image analysis comparing both materials showed significant inflammatory cells in the human graft at 15 and 30 PO, thicker capsular formation in the porcine tissue at 60 PO, increased number of vessels inside the implants and in the surrounding tissues in the porcine graft and a similar absorption pattern in both materials at 180 PO. The histological findings showed that both tissues were well-tolerated when implanted in the subcutaneous tissue of rats, allowing us to consider the porcine acellular dermal graft as a provisional alternative material for reconstructive plastic surgery. Copyright © 2005 Taylor & Francis LLC.

Spontaneous resolution rates of vesicoureteral reflux in Brazilian children: A 30-year experience

Objective: We evaluated clinical characteristics of primary vesicoureteral reflux (VLJR) in infants in a 30-year period in Brazil with special reference to the relation of renal parenchymal damage to urinary tract infection and gender. Materials and Methods: From 1975 through 2005, 417 girls (81.6%) and 94 boys (18.4%) with all grades of reflux were retrospectively reviewed. Patients were categorized by the worst grade of reflux, maintained on antibiotic prophylaxis and underwent yearly voiding cystourethrography until the reflux was resolved. VUR was considered resolved when a follow-up cystogram demonstrated no reflux. Surgical correction was recommended for those who fail medical therapy, severe renal scarring or persistent VUR. Results: Grades I to V VUR resolved in 87.5%, 77.6%, 52.8%, 12.2% and 4.3%, respectively. Renal scars were present at presentation in 98 patients (19.2%). Neither gender nor bilaterality versus unilaterality was a helpful predictor of resolution. The significant difference was found among the curves using the log rank (p < 0.001) or Wilcoxon (p < 0.001) test. Conclusion: Despite the current use of screening prenatal ultrasound, many infants are still diagnosed as having vesicoureteral reflux only after the occurrence of urinary tract infection in our country. Scarring may be associated to any reflux grade and it may be initially diagnosed at any age but half of the scars are noted with higher grades of reflux (IV and V). The incidence of reflux related morbidity in children has significantly diminished over the last three decades.

Developing new radiotherapy techniques using linac based gamma radiation sources

A major challenge in cancer radiotherapy is to deliver a lethal dose of radiation to the target volume while minimizing damage to the surrounding normal tissue. We have proposed a model on how treatment efficacy might be improved by interfering with biological responses to DNA damage using exogenous electric fields as a strategy to drastically reduce radiation doses in cancer therapy. This approach is demonstrated at this Laboratory through case studies with prokaryotes (bacteria) and eukaryotes (yeast) cells, in which cellkilling rates induced by both gamma radiation and exogenous electric fields were measured. It was found that when cells exposed to gamma radiation are immediately submitted to a weak electric field, cell death increases more than an order of magnitude compared to the effect of radiation alone. This finding suggests, although does not prove, that DNA damage sites are reached and recognized by means of long-range electric DNA-protein interaction, and that exogenous electric fields could destructively interfere with this process. As a consequence, DNA repair is avoided leading to massive cell death. Here we are proposing the use this new technique for the design and construction of novel radiotherapy facilities associated with linac generated gamma beams under controlled conditions of dose and beam intensity.

Reconstruction of Mandibular Segmental Defects Using the Guided-Bone Regeneration Technique With Polylactide Membranes and/or Autogenous Bone Graft: A Preliminary Study on the Influence of Membrane Permeability

Purpose: Bone maintenance after mandibular reconstruction with autogenous iliac crest may be disappointing due to extensive resorption in the long term. The potential of the guided-bone regeneration (GBR) technique to enhance the healing process in segmental defects lacks comprehensive scientific documentation. This study aimed to investigate the influence of polylactide membrane permeability on the fate of iliac bone graft (BG) used to treat mandibular segmental defects. Materials and Methods: Unilateral 10-mm-wide segmental defects were created through the mandibles of 34 mongrel dogs. All defects were mechanically stabilized, and the animals were divided into 6 treatment groups: control, BG alone, microporous membrane (poly L/DL-lactide 80/20%) (Mi); Mi plus BG; microporous laser-perforated (15 cm2 ratio) membrane (Mip), and Mip plus BG. Calcein fluorochrome was injected intravenously at 3 months, and animal euthanasia was carried out at 6 months postoperatively. Results: Histomorphometry showed that BG protected by Mip was consistently related to larger amounts of bone compared with other groups (P ≤ .0001). No difference was found between defects treated with Mip alone and BG alone. Mi alone rendered the least bone area and reduced the amount of grafted bone to control levels. Data from bone labeling indicated that the bone formation process was incipient in the BG group at 3 months postoperatively regardless of whether or not it was covered by membrane. In contrast, GBR with Mip tended to enhance bone formation activity at 3 months. Conclusions: The use of Mip alone could be a useful alternative to BG. The combination of Mip membrane and BG efficiently delivered increased bone amounts in segmental defects compared with other treatment modalities. © 2008 American Association of Oral and Maxillofacial Surgeons.

Estudo da perda da tensao do enxerto de tendão calcâneo bovino

Lesion of the anterior cruciate ligament (ACL) in the knee is a problem that affects animals as well as humans and may evolve with joint instability that is often symptomatic and incapacitating. The main option for ligament substitution is the autologous tendon graft. The graft undergoes tensioning during ACL reconstructive surgery to reestablish the normal laxity of the ACL- deficient knee. Although graft tensioning plays a fundamental role in postoperative clinical evolution, ideal tensioning levels have not been established in the literature. Therefore, graft elongation that may occur over time is still one of the main reasons for ligament reconstruction failure. In this study, ten bovine calcaneus tendons underwent two successive assays of physiological tensioning for a maximum deformation of 2.5% of the initial tendon length, maintained for 600s with force (N) values recorded at zero time (initial), 300s and 600s. At the end of the first assay, the tendon returned to its initial length and was maintained at rest for 300s and then the next tensioning assay was initiated, repeating the previous procedure. Statistical analysis revealed that tendon elongation is more pronounced during the initial 300s, reflecting a more accentuated decline in the tension values of the graft. Therefore, 300s after tensioning and fixing the graft, the surgeon can assess with more precision if the tensioning level was adequate.