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ObjectiveOptimal tooth reduction is a key requirement for aesthetics, function, and the longevity of fixed restorations. Research has demonstrated that controlled and conservative tooth preparation is crucial for the long-term success of adhesive restorations. Different techniques of fabricating reduction guides have been previously reported in literature. The present technical note describes the fabrication technique and clinical application of a customized metal preparation reduction guide.Material and methodPatient presented with tilted maxillary left central incisor. The flared-out part of the tooth was modified prior to veneer restoration preparation. Resin pattern reduction guide was fabricated on the diagnostic cast with a window on the tilted mesial portion of the tooth. After intraoral evaluation, resin pattern guide was casted. Metal reduction guide was place intraorally and reduction was provided on the exposed surface of the tooth. After the removal of the tilted portion, a harmonious arch form allowed the clinician to provide adequate evaluation and preparation for veneer restorations.ResultsThe device demonstrated good practical value, allowing for selective and controlled reduction of tooth structure, and definitive protection of adjacent tooth surfaces from iatrogenic damage. The clinical outcome successfully addressed the patient’s restorative and aesthetic needs, and the veneer was stable 2 years postoperatively.ConclusionUse of a metal guide assists clinicians to provide a more predictable reduction of a desired tooth surface, while decreasing the risk of compromising the other/adjacent tooth surfaces.  相似文献   
23.
For percutaneous observation of lesions near the spinal cord and percutaneous spinal laser surgery under the visual field, we studied a method and approach to the spinal cord and intraspinal surgical procedures with laser using a newly developed, small-diameter laser endoscope. The subarachnoid and epidural spaces of a goat were punctured using a 17-gauge epidural needle, and the endoscope (diameter 0.7 mm) was inserted through the needle. The spinal cord and surrounding tissue were observed. Next, an endoscope (diameter 1.5 mm) was inserted into the subarachnoid space, and the quality of the picture and manageability of the endoscope were examined. The Xe:Cl excimer laser was irradiated to a nerve root through a 0.4 mm optical fiber for laser transmission through this endoscope. The spinal cord, nerve roots, and arachnoid were clearly observed through this endoscope. The pulsation of the artery accompanying a root was seen clearly, and the quality of the picture of the endoscope was thought to be sufficient for diagnosis. The nerve root was cut within 30 seconds by excimer laser, and the possibility of laser surgery was demonstrated. Although it was shown that this endoscope could be a useful diagnostic and therapeutic tool, improvement in the manageability of the tip of the endoscope was considered to be important for a clinically usable endoscope.  相似文献   
24.
BACKGROUND: Cyclosporine A (CsA) is a critical immunosuppressive drug with a narrow therapeutic range and wide interindividual variation in its pharmacokinetics. Many factors, including P-glycoprotein (PGP), influence the oral bioavailability and interpatient variability of CsA. A number of polymorphisms have been identified in the human MDR1 gene, and some of them have been found to be associated with an altered expression of PGP. We have investigated the role of these polymorphisms in CsA absorption from kidney transplant recipients. In addition, we also investigated the effect of amlodipine on CsA absorption. METHODS: The area under the time-concentration curve from 0 to 2 hr (AUC(0-2)) estimated by the trapezoidal rule was used for the evaluation of extent of CsA absorption. The genotypes were identified by a polymerase chain reaction, restriction fragment length polymorphism analysis. RESULTS: No association was found between polymorphisms in the MDR1 and CsA AUC(0-2)/dose/kg. In contrast, the combination of amlodipine significantly increased CsA AUC(0-2)/dose/kg (706.2 microg x hr/L to 819.2 microg x hr/L, P<0.05). Furthermore, we attempted to compare MDR1 polymorphisms and the absorption of CsA again without patients receiving amlodipine, but there was still no significant difference. CONCLUSIONS: There is no relationship between polymorphisms for MDR1 and CsA absorption, suggesting polymorphisms for MDR1 cannot account for the interpatient variability of CsA. Amlodipine, which is the substrate of PGP, significantly increased CsA absorption. These results indicate that PGP plays a significant role in CsA absorption, but its polymorphisms could not influence the CsA absorption.  相似文献   
25.
The undulation pump total artificial heart (UPTAH) is a unique, implantable, total artificial heart (TAH) that uses undulation pumps. To achieve long-term survival in animals with physiologic hemodynamic conditions, a control method based on conductance and arterial pressure was applied to UPTAH. With this control method, called 1/R control, survival periods of 50 days (No. 0016, 49.6 kg) and 54 days (No. 0030, 42.5 kg) were obtained in adult female goats. In No. 0016, 1/R control was applied to the left pump, whereas in No. 0030, it was applied to the right pump. Another pump was used for left-right balance control. The control stability was better in No. 0030 than in No. 0016. The sucking effect of the left atrium was remarkable in No. 0016, possibly because of a time delay when left-right balance control was performed with the right pump. In No. 0016, the cause of death was probably a thrombus flown from a panus in the left atrium. It is possible that the left atrial suction effect influenced the thrombus and panus formation in the left atrium. In No. 0030, the cause of death was a small rupture of the membrane in the right pump. The rupture may have been caused by excessive negative pressure inside the pump. This pressure resulted from suction of the right atrium because of an unexpected control excursion, which was probably caused by a software bug. It will be necessary to redesign the undulation pump and improve the software to achieve longer survival periods for animals with physiologic hemodynamic conditions.  相似文献   
26.
This paper provides an intercomparison of the HPA male and female models, NORMAN and NAOMI with the National Institute of Information and Communications Technology (NICT) male and female models, TARO and HANAKO. The calculations of the whole-body SAR in these four phantoms were performed at the HPA, at NICT and at the Nagoya Institute of Technology (NIT). These were for a plane wave with a vertically aligned electric field incident upon the front of the body from 30 MHz to 3 GHz for isolated conditions. As well as investigating the general differences through this frequency range, particular emphasis was placed on the assumptions of how dielectric properties are assigned to tissues (particularly skin and fat) and the consequence of using different algorithms for calculating SAR at the higher frequencies.  相似文献   
27.
Germline mutations in the RET proto-oncogene are responsible for the development of human hereditary diseases, including multiple endocrine neoplasia (MEN) type 2A and 2B, familial medullary thyroid carcinoma (FMTC), and Hirschsprung's disease (HSCR). It has been reported that some families developed both MEN 2A/FMTC and HSCR, in which a mutation in a cysteine residue at codon 609, 618, or 620 in the RET gene was present. Here we report a novel RET mutation detected in a Japanese family with medullary thyroid carcinoma and HSCR. A germline mutation in cysteine 611 of the RET gene was identified in this family, which introduced an amino-acid change from cysteine to serine. By biological and biochemical analyses of mutant RET proteins, we previously predicted the potentiality that amino-acid substitution for cysteine 611 as well as cysteines 609, 618, and 620 would promote the development of MEN 2A/FMTC and HSCR. This clinical case substantiates our suggestion for the mechanism of the development of both the diseases.  相似文献   
28.
We compared the thin-section CT findings of 11 intrapulmonary lymph nodes with pathological findings and evaluated the possibility of CT scan differential diagnosis from pulmonary metastatic nodules. First, we retrospectively reviewed CT scan and pathological findings of intrapulmonary lymph nodes. The median size of these nodules was 6.2 mm. The nodules appeared round (n=3) or angular (n=8) in shape with a sharp border, and they were found below the level of the carina. The median distance from the nearest pleural surface was 4.6 mm, and 3 of the 11 nodules were attached to the pleura. On thin-section CT scan, linear densities extending from the intrapulmonary lymph nodes were frequently visualized, and were pathologically proven to be ectatic lymphoid channels. We then compared the thin-section CT findings of 8 metastatic nodules less than 1 cm in diameter with those of the 11 intrapulmonary lymph nodes. The median size of these nodules was 6.8 mm, and the median distance from the nearest pleural surface was 16 mm. All nodules appeared round in shape. None of the nodules had linear densities extending from the nodules. The linear densities on thin-section CT scan may be the most useful characteristic of intrapulmonary lymph nodes, when differential diagnosis from metastatic nodules is necessary.  相似文献   
29.
We report a case of a duodenal gastrointestinal stromal tumor (GIST) necessitating urgent surgery because of a gas figure on computed tomography (CT). A 46-year-old woman, complaining chiefly of upper abdominal pain and tarry stools, consulted a local doctor. A gastrointestinal fiberscopy revealed an ulcer in the second part of the duodenum, and the patient was admitted to our hospital where a dynamic CT scan showed a hypervascular solid tumor in the pancreatic head. A repeat CT scan done 4 days later showed a gas figure in the tumor, necessitating an emergency pylorus-preserving pancreatoduodenectomy (PpPD). First, we performed a tube pancreatostomy for complete external drainage of the pancreatic juice, and planned a second-stage pancreatojejunostomy for the near future. Histopathologically, the tumor was diagnosed as a GIST originating in the duodenum. The patient was discharged on postoperative day 23 after an uneventful postoperative recovery. Her local doctor completed the second-stage pancreatojejunostomy.  相似文献   
30.
Miyoshi Y  Yunoki M  Yano A  Nishimoto K 《Neurosurgery》2003,52(1):224-7; discussion 227
OBJECTIVE AND IMPORTANCE: Diencephalic syndrome of emaciation (DS) is seen almost exclusively in infants and young children, and only two cases of DS in adults have been reported previously. We describe a case of DS associated with a third ventricle intrinsic craniopharyngioma in an adult patient. CLINICAL PRESENTATION: A 54-year-old man presented with profound emaciation, disorientation, memory loss, and psychological disorders. Computed tomographic scanning and magnetic resonance imaging of his brain disclosed a tumor within the third ventricle. The preoperative endocrinological examination indicated an elevated growth hormone level and a decreased somatomedin C level. INTERVENTION: The patient underwent partial resection of the tumor, which was adherent to the floor of the third ventricle but not to the ventricle wall, by an interhemispheric-transcallosal approach. The histological examination revealed a squamous papillary-type craniopharyngioma. The patient received 50 Gy of radiotherapy, which resulted in 90 to 95% reduction of the tumor size within 6 months, as indicated by the magnetic resonance images presented. The psychological disorders, memory disturbance, and severe emaciation improved gradually thereafter. CONCLUSION: Although extremely rare, DS can occur in an adult harboring a tumor in the anterior hypothalamus.  相似文献   
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