Modeling T(1) and T(2) relaxation in bovine white matter.

The fundamental basis of T1 and T2 contrast in brain MRI is not well understood; recent literature contains conflicting views on the nature of relaxation in white matter (WM). We investigated the effects of inversion pulse bandwidth on measurements of T1 and T2 in WM. Hybrid inversion-recovery/Carr-Purcell-Meiboom-Gill experiments with broad or narrow bandwidth inversion pulses were applied to bovine WM in vitro. Data were analysed with the commonly used 1D-non-negative least squares (NNLS) algorithm, a 2D-NNLS algorithm, and a four-pool model which was based upon microscopically distinguishable WM compartments (myelin non-aqueous protons, myelin water, non-myelin non-aqueous protons and intra/extracellular water) and incorporated magnetization exchange between adjacent compartments. 1D-NNLS showed that different T2 components had different T1 behaviours and yielded dissimilar results for the two inversion conditions. 2D-NNLS revealed significantly more complicated T1/T2 distributions for narrow bandwidth than for broad bandwidth inversion pulses. The four-pool model fits allow physical interpretation of the parameters, fit better than the NNLS techniques, and fits results from both inversion conditions using the same parameters. The results demonstrate that exchange cannot be neglected when analysing experimental inversion recovery data from WM, in part because it can introduce exponential components having negative amplitude coefficients that cannot be correctly modeled with nonnegative fitting techniques. While assignment of an individual T1 to one particular pool is not possible, the results suggest that under carefully controlled experimental conditions the amplitude of an apparent short T1 component might be used to quantify myelin water.

[Reduction of radiation exposure by the use of fluoroscopic guidance in transpedicular instrumentation]. / Redukce radiacní záteze uzitím fluoroskopické navigace pri transpedikulární instrumentaci.

PURPOSE OF THE STUDY: The variability in width, height, and orientation of spinal pedicles makes pedicle screw insertion a delicate operation. Fluoroscopic guidance often exposes the patient and especially surgeons to relatively high doses of ionising radiation. The use of pulsed fluoroscopy is safer, as compared to continuous fluoroscopy, because of reduced radiation exposure. There are increasing numbers of literature reports regarding the high doses of radiation to which orthopaedic and spine surgeons are exposed during surgical procedures. Spine surgery can be associated with significant radiation exposure to the surgical staff. The purpose of this prospective study was to compare a computer-assisted navigation with a conventional procedure in order to assess if it is possible to reduce radiation exposure while preserving the accuracy of screw placement. MATERIAL AND METHODS: The first "conventional" group consisted of 30 patients, with an average of 1.9 segments of the lumbar spine stabilised. Screws were inserted transpedicularly under image intensifier guidance. In the second "navigated" group of 30 patients, stabilisation of 1,8 segments was performed on average. A CT-free fluoroscopic 2D spinal navigation system (VectorVision, Brain LAB, Germany) was used intra-operatively. It combines image-guided surgery with C-arm fluoroscopy. For each surgery (navigated or not), the duration of irradiation was recorded. The irradiation duration was collected from the X-ray image intensifier. In both groups the screw positioning accuracy was controlled intra-operatively according to Learch's, Acikbas's, and Whitecloud's methods from AP and lateral images and by meticulous pedicle palpation. RESULTS: The irradiation duration calculated to one vertebra (two screws) was significantly shorter in the second (navigated) group (3.4 s) than in the first (conventional) group (14.4 s). The mean duration of data registration was 6.0 minutes (range, 3 to 11 minutes). The mean ratio according to Acikbas's calculation method was 43.2 % (range, 32 % to 74 %) in the first (conventional) group and 44.1 % (range, 35 % to 76 %) in the second (navigated) group. DISCUSSION: During a conventional surgical procedure many X-ray images are made to control the accuracy of screw insertion. If the trajectory is not satisfying, it must be corrected or the pedicle is drilled again, always with a new fluoroscopic control. The process is repeated until satisfactory orientation is achieved. This is the explanation for a much longer duration of irradiation in conventional procedures. Navigation facilitates the surgical act, enabling us to acquire the right position of all screws, with only an AP image and a lateral image at the beginning of instrumentation for data registration; prolongation of the operative time is irrelevant. CONCLUSIONS: Navigation allows us to keep the same accuracy of pedicle screw placement while reducing radiation exposure of the surgeons and operating room staff by about one quarter. In multiple-level vertebral instrumentations this reduction is more pronounced. In centres where many procedures involving spine instrumentation are done every day, the "saved" exposure time can amount to hours.

A prática da automedicação por funcionários de uma Instituição de Ensino Superior portadores de enxaqueca / Practice of self-medication of migraine by employees at a higher education institution

O objetivo desta pesquisa foi identificar, na prática de automedicação, possíveis interações medicamentosas e descrever o perfil dos funcionários portadores de enxaqueca de uma Instituição de Ensino Superior localizada no município de Ijuí-RS. Este estudo foi aprovado pelo Comitê de Ética em Pesquisa da UNIJUI. Após a busca dos enxaquecosos, foi aplicado um questionário padronizado com perguntas acerca da patologia. Foram entrevistados, com consentimento, 32 indivíduos, sendo que a maioria (31-97%) tinha idade entre 30 e 39 anos (37,5%), pele branca (94%), eram casados (59%) e, no caso das mulheres, 71% (22) apresentavam ciclo menstrual regular e 55% (17) usavam anticoncepcional oral. Dentre os fatores desencadeantes da enxaqueca, os mais citados foram alguns tipos de alimentos, seguidos do estresse e fatores hormonais associados ao ciclo menstrual. Trinta (93,75%) voluntários praticavam automedicação, sendo que todos faziam uso de analgésicos e associações de fármacos. Portanto, verifica-se uma relação entre a patologia e a automedicação. Foram observadas 15 interações medicamentosas diferentes. Vinte (62,5%) indivíduos foram expostos a, pelo menos, uma interação decorrente da automedicação, ao consumo de medicamentos crônicos prescritos, a álcool e a cigarros. Nesse sentido, cabe ao profissional farmacêutico auxiliar o portador de enxaqueca no reconhecimento dos fatores desencadeantes desse problema para promover o uso racional de medicamentos e incentivar a automedicação responsável.

The aim of this study was to describe the profile of migraine-sufferers employed at a higher education institution located in the town of Ijuí (RS, Brazil) and identify possible drug interactions resulting from the self-medication practiced by those patients. After an active search for migraine patients, a standard questionnaire was used to enquire about their condition and themselves. The study was approved by the Research and Ethics Committee at UNIJUI. Thirty-two consenting adults were interviewed, most of whom (31, 97%) were aged between 30 and 39 years (37.5%), of white skin (94%) and married (59%), while among the women, 71% (22) had a regular menstrual cycle and 55% (17) used an oral contraceptive. Among migraine-triggering factors, most subjects cited specific foods, followed by stress and hormonal factors associated with the menstrual cycle. Thirty (93.75%) volunteers practiced self-medication, all of them making use of analgesics and combinations of drugs, showing that there was a relation between this condition and self-medication. The results revealed 15 different drug interactions. Twenty (62.5%) subjects were exposed to at least one interaction arising from self-medication, chronic prescribed drug use, alcohol and cigarettes. Accordingly, it is up to the pharmaceutical professional to help the migraine patient to recognize triggering factors, to promote the rational use of medicines and encourage responsible self-medication.

[Latissimus dorsi transfer for the treatment of irreparable craniodorsal tears of the rotator cuff]. / Transfer m. latissimus dorsi pri nereparabilních kraniodorzálních defektech manzety rotátoru.

PURPOSE OF THE STUDY: Latissimus dorsi transfer is a relatively complicated procedure subsequently requiring an active, long-term physical therapy. The surgeon's performance and a patient's effort are therefore of worth consideration. However, sutures of massive rotator cuff tears do not always produce good results. The aim of the study is to evaluate the role of latissimus dorsi transfer in the treatment of these shoulder pathologies. MATERIAL: A total of 21 patients were evaluated. Their age at the time of surgery ranged from 48 to 63 years, with an average of 54.8 years. A minimum follow-up was three years, the average was 47 months (70-36 months). The indication for surgery included a massive rotator cuff tear, without symptoms of arthropathy and with normal subscapularis muscle function, which had been resistant to conservative treatment for 6 months at least. In 13 patients, transfer was performed after previous surgery on the rotator cuff. METHODS: The procedure was carried out in a lateral position. The latissimus dorsi tendon was cut off just at its attachment to the humerus, the muscle was mobilised and the musculo-tendinous flap was released to reach the proximal operative wound and to cover the greater tuberosity of the proximal humerus. A shoulder abduction splint was used to immobilise the upper extremity for 6 weeks. Active and supervised individual physical therapy followed. RESULTS: Subjective evaluation was excellent in 10, good in 9, and poor in 2 patients. The average Constant-Murley score improved by 32.25 points as compared before surgery (from 38.50 to 70.75). The evaluation of active arm elevation in the frontal plane showed improvement in 16 patients (77 %) by 40 degrees on average, no change in five patients (23%), and no deterioration in any of the patients. Active external rotation with the arm held at the body side improved by 14 degrees on average. Progression of radiographic changes indicating arthropathy was recorded in five patients.Post-operative haematoma, developed three patients it was treated by needle aspiration in one, and drainage in two patients. DISCUSSION: The results presented here are in agreement with those reported in the international literature.The method of latissimus dorsi transfer shows poorer outcomes after previous attempts to suture of massive rotator cuff tears. In patients with a restricted range of motion before surgery, the post-operative shoulder motion achieved at the final evaluation is also lower. CONCLUSIONS: When based on a correct indication, latissimus dorsi transfer with an uncomplicated post-operative therapy will result in improvement of shoulder function and pain relief, and it is therefore justified. One of the prerequisites for good results is the initial patient's consent with a supervised, active and long-term post-operative physical therapy. The transfer itself is a demanding surgical procedure associated with several risks and it should therefore be performed by an experienced and competent surgeon with a deep knowledge of shoulder girdle anatomy.

A computerized maintenance management system's requirements for standard operating procedures.

From this review of the 6 aspects of opportunity for inconsistency to corrupt or skew the reliability of data, it becomes apparent why members of management must provide the standards of operation and use within the CMMS for their employees. The possibility of poor data integrity due to any one of these aspects may not be severe; however, the severity is compounded and inevitable when different aspects are combined. Responding to information collected through the CMMS can be effective only if the data are reliable. With SOPs, management has provided their personnel with the necessary tools to ensure department-wide consistency. Management cannot afford to allow any one [table: see text] individual to apply personal interpretations of the importance and requirements in their approach to using the CMMS. If this is permitted, the loss of integrity due to one individual's judgment grows rapidly when data are analyzed at the departmental level. Standard operating procedures go beyond creating a "how to" for the CMMS; they provide the critical elements for collecting responsible and reliable data.

[Changes in clinical and epidemiologic characteristics in Western Bohemia of invasive meningococcal disease associated with the occurrence of an invasive clone of Neisseria meningitidis]. / Zmeny klinických a epidemiologických charakteristik invazivního meningokokového onemocnení v západních Cechách v souvislosti s výskytem invazivního klonu Neisseria meningitidis.

The authors analyzed the incidence of meningococcal diseases in the West Bohemian region in 1982-1996. The draw attention to changes of clinical and epidemiological characteristics of the disease which appeared in 1994 in conjunction with a new invasive clonus of Neisseria meningitidis C:2a:P1.2, P1.5, ET-15/37. While in 1982-1993 invasive meningococcal diseases had in 75% the course of meningitis with a relatively low fatality (4%), during the subsequent period a marked change occurred. Since 1994 the disease took in the West Bohemian region in 58% the course of sepsis with a fatality of 16%. 25% cases of meningococcal meningitis were diagnosed combined sepsis and meningitis in 17%. The disease lost its seasonal character and the authors confirmed the highest incidence of the disease in the age group from 15-19 years and 0-4 years. Neisseria meningitidis group C was detected in 1994-1996 in 73% and the invasive clone C:2a:P1.2, P1.5, ET-15/37 in 62%.

Elastin powder produced for cosmetic purposes does not affect formation of granulation tissue.

A suspension of elastin powder that is produced for cosmetic purposes has been applied on open skin wounds made in rats. Elastin particles (diameter smaller than 0.1 mm) prepared by extraction of bovine nuchal ligament with alkali had no effect on wet weight and dry weight of granulation tissue formed in the wound within 6 days. Hydroxyproline content which indicates collagen content of the granulation tissue was not also changed.