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Biomedical subjects

L Da Silva

Publications and source records attributed to L Da Silva.

10 recordsLinked to original sources

[Wilson's disease: study of 6 neurologic forms observed at the University Hospital in Conakry].

This report describes 6 cases of Wilson's disease observed at the University Hospital Center in Conakry, Guinea. Presenting symptoms involved extrapyramidal syndrome in 4 cases, psychomotor epilepsy in 1, and confusional syndrome in 1 case. Diagnosis was based on neuropsychic manifestations, Kayser-Fleicher corneal ring, liver failure, and impaired copper metabolism. Brain CT-scan depicted normal features in 3 cases, symmetric hypodensity of the lenticular nucleus in one, discrete ventricular dilatation of in one a and cortico-subcoetical atrophy in one.

Adolescent↗

Equation of state data for iron at pressures beyond 10 Mbar.

We present equation of state points for iron, in the pressure range 10-45 Mbar, the first obtained with laser-driven shock waves. The experiment has been performed with the high energy laser Phebus, optically smoothed with Kinoform phase plates. Our results double the set of existing experimental data at very high pressures showing good agreement with the predictions of the quotidian equation of state model and with previous results.

Journal Article↗

Frontal-plane lateral border movements and chewing cycle characteristics.

We studied the dental contact section of the chewing cycle, the most important section in terms of function (as it governs the effectiveness of food trituration). Specifically, we determined closing phase dental contact distance and lateral path inclination in a sample of healthy subjects, and investigated possible relationships between these variables and Ahlgren chewing cycle type. The chewing cycle was characterized in 63 healthy subjects by frontal plane kinesiography. In all cases kinesiographs were obtained for both right- and left-side chewing, with chewing gum as bolus. In all cases we determined closing phase dental contact distance, lateral path inclination and Ahlgren chewing cycle type. Most subjects (84%) showed 'normal' chewing cycles (Ahlgren types I-IV); inverted, contralateral and irregular cycles (types V-VII) were infrequent. Mean dental contact distance was 0.9 mm for right-side chewing and 1.2 mm for left-side chewing. Mean lateral path inclination was 35 degrees for right-side chewing and 37 degrees for left-side chewing. Normal chewing cycles are generally bilateral, whereas abnormal chewing cycles are never bilateral. Border movement distance does not differ in any consistent way between 'chopping' and 'grinding' chewing cycle types. Closing phase dental contact distance showed a significant positive correlation with lateral path inclination.

Adult↗

Laparoscopy-assisted aneurysm resection as a minimal invasive alternative in patients unsuitable for endovascular surgery.

OBJECTIVE: So far, endovascular surgery has been the only minimal invasive way to treat patients with abdominal aortic aneurysms (AAAs). With hand-assisted laparoscopic surgery (HALS), laparoscopic transperitoneal endoaneurysm repair can be performed through a 6-cm mini-incision only. We wanted to evaluate whether this laparoscopic technique can be offered as a minimal invasive alternative in patients unsuitable for endovascular AAA repair. MATERIAL AND METHODS: Forty patients were referred for endovascular AAA repair. Three patients had to be excluded from the study. Endovascular AAA exclusion was finally performed in 13 patients. Laparoscopic AAA resection was performed in 24 patients. Hand-assisted laparoscopic surgery with transperitoneal access and endoaneurysm repair was accomplished in all patients unsuitable for an endovascular procedure. The outcome after endovascular repair was compared with the outcome of patients who underwent laparoscopy. RESULTS: In the laparoscopic group, conversion to an open procedure was necessary in one case. One patient in this group died (4.1%) postoperatively. There were four complications in each group. In the endovascular group we had one endoleak type II and one graft thrombosis, which required a reoperation. After endovascular treatment, patients were transferred significantly less frequently to the intensive care unit, and they could resume oral feeding earlier. Mobilization and postoperative hospital stay did not differ significantly between the groups. CONCLUSION: Laparoscopic AAA resection with the use of the technique described can be routinely offered to patients unsuitable for endovascular AAA exclusion with excellent long-term results similar to open surgery. A controlled study is clearly indicated to evaluate the role of laparoscopic techniques in aneurysm surgery.

Aortic Aneurysm, Abdominal↗

[Allogenic liver transplantation: a form of "gene therapy" in metabolic diseases. Munich results and a review].

INTRODUCTION: Liver transplantation is the method of choice for metabolic diseases and end-stage liver failure. METHODS: At the Klinikum Grosshadern we have performed liver transplantation for inborn errors of metabolism in 24 patients (5.3% of all transplantations, 16 adults, age 39 +/- 13 years; 8 children, age 9 +/- 3 years); 19 patients received a transplant for end-stage liver disease, and in 5 cases because of fulminant hepatic failure. RESULTS: Twenty-four patients received 27 transplants. In 3 cases, a split-liver transplantation was performed; one patient received a combined lung-liver graft. The 5-year survival rate for children is 100% and for adults 68%. CONCLUSIONS: Liver transplantation for inborn errors of metabolism not only replaces the diseased organ, but also leads to complete reversal of the metabolic defect.

Adult↗

Video-assisted aortic surgery.

BACKGROUND: There are several laparoscopic techniques that can be used to perform a total or video-assisted aorto-femoral bypass grafting procedure. Major drawbacks of laparoscopic aortic surgery are the long operating times and the steep learning curve required for these procedures. Hand-assisted laparoscopy is a novel technique that allows surgeons to use their hands and laparoscopic instruments in the operative field while maintaining a pneumoperitoneum. STUDY DESIGN: A prospective nonrandomized study was conducted in a community medical center. Any patient with aortoiliac occlusive disease or an abdominal aortic aneurysm who was determined to be suitable for a laparoscopic aorto-femoral bypass grafting procedure was included in the study. The main outcomes measured were: operating time, aortic cross-clamp time, incision size, complications, conversion rate to an open procedure, length of stay in the ICU, and postprocedural hospital stay. A concurrent control group of 20 patients was compared with the minimally invasive group. RESULTS: Forty-one consecutive patients were scheduled for the laparoscopic operation. Conversion to an open procedure was necessary in three patients. There were two major complications, including the development of renal failure in one patient who died 28 days postoperatively. The mean postprocedural hospital stay was 4.5 +/- 2.5 days (range 2 to 15 days). The mean operating time was 163.1 +/- 38.7 minutes, including an aortic cross-clamp time of 38.3 +/- 9.7 minutes. Postoperative hospital stay and the time required in the ICU were significantly shorter after the laparoscopic procedure compared with a conventional bypass grafting procedure. CONCLUSIONS: Hand-assisted laparoscopy is a minimally invasive technique with operating times and outcomes similar to those of conventional procedures. The possibilities of this technique in patients with aortoiliac disease should be evaluated in a prospective randomized study.

Aged↗

Titanium for removable denture bases.

The aim of the present study was to compare titanium-base and resin-base maxillary complete dentures. In 13 patients with a maxillary complete denture with a titanium base (group I) and in 12 patients with a maxillary complete denture with a resin base (group II), the (a) patient's adaptation to the denture, (b) denture retention and (c) appearance of the mucosa under the denture were evaluated. In all cases, the adaptation was assessed with a questionnaire, while the retention and the appearance of the mucosa were assessed by clinical examination. None of the three measures considered (adaptation, retention and mucosa appearance) differed significantly between patients with titanium-base dentures and patients with resin-base dentures. Titanium bases are suitable for dentures likely to be subject to severe mechanical stresses (as in the case of maxillary complete dentures opposing natural teeth), and in patients who show hypersensitivity responses to other materials.

Acrylic Resins↗

Descending aorta-to-femoral artery bypass: preliminary experience with a thoracoscopic technique.

Descending aorta-to-femoral artery bypass is a durable procedure with excellent long-term patency rates. The operation is usually performed using a lateral thoracotomy combined with retroperitoneal tunneling of the graft. Assuming that a smaller incision would reduce the operative trauma, minimally invasive video endoscopic techniques were used to perform a thoracoscopic bypass operation. In all patients, exposure of the descending aorta was obtained using thoracoscopy. This was accomplished with a maximum of four ports. For placing the conventional side-biting aortic clamp, a 3- to 4-cm incision was necessary. Using this incision as an access port, the proximal anastomosis was sutured endoscopically. Retroperitoneal tunneling was performed using laparoscopically guided balloon dissection. Eleven consecutive patients underwent surgery. In two patients, conversion to a standard thoracotomy was necessary because of extensive intrathoracic adhesions. There were no major complications, except for one hematoma. After a mean follow-up of 9.5 months, all bypass grafts were still patent. Patients could be discharged after a mean postprocedural hospital stay of 7.4 days (range, 5-12). Thoracoscopic descending aorta-to-femoral artery bypass is an operation with excellent patency rates; however, it is a novel technique that still requires further technical improvements. Clinical studies are needed to prove the safety and efficacy of this minimally invasive technique.

Abdomen↗

New technologies, designs and materials for removable maxillary obturator prostheses.

The size and location for maxillary defects influence the difficulty of prosthetic rehabilitation. In all such cases, specially made obturator prosthesis's necessary to restore masticatory function and improve speech, deglution and esthetics. Obturator prostheses vary in size and shape depending on the extent of the defect. Various methods and techniques have been described for the fabrication of removable obturator prostheses. The aim of the present work was to review the progress made in technologies, designs and materials for prosthesis of this type.

Composite Resins↗