Three-dimensional evaluation of condylar position after mandibular reconstruction with a fibula free flap-comparison of different surgical techniques.

Three-dimensional positional changes of the temporomandibular joint after mandible reconstruction using microvascular fibula flaps were investigated in 58 patients. The results of preoperative virtually planned surgery, intraoperative resection- and cutting-guided surgery, and non-guided surgery were compared. Pre- and postoperative computed tomography data of each patient were processed and superimposed digitally. The condyle deviations and rotations along the axes and planes of the skull, as well as Euclidean distances, were determined. Reliability analyses, descriptive statistics, and non-parametric tests were performed with the alpha level set at P = 0.05. Reliability proved to be excellent for all variables. The median Euclidean distance was 2.07 mm for the left condyle and 2.11 mm for the right condyle. Deviations of ≥ 10 mm occurred in nine (16%) cases. The maximum deviation occurred in the horizontal plane and the least deviation in the sagittal plane. Median rotation was ≤ 1.4° around all axes. The condylar displacements did not differ significantly between the different surgical techniques investigated. The three-dimensional measurement method applied is highly reliable for evaluating the three-dimensional condylar position after mandibular reconstruction.

[Radiotherapy for patients with early-stage glottic squamous cell carcinoma of the larynx: Interest of hypofractionation?] / Radiothérapie du carcinome épidermoïde du larynx de stade précoce, étage glottique : intérêt de l'hypofractionnement ?

Hypofractionated radiotherapy of early-stage squamous cell carcinoma of the glottic larynx is a promising treatment option. This can be divided into radiotherapy with moderate hypofractionation (up to 2.5Gy per fraction), more intense hypofractionation (between 2.5 and 4.5Gy per fraction) and stereotactic radiotherapy (above 4.5Gy per fraction). Most studies evaluating moderate hypofractionation show a local control rate between 85 and 95%. Acute laryngeal toxicity is superior to conventional treatment, but only for grades 1 and 2, with no significant difference reported for severe toxicity. Stereotactic radiotherapy in this pathology is also an emerging entity, but some authors have reported significant toxicity. There are currently no standardized guidelines for treatment and management regimen. We conducted a systemic review of published prospective and retrospective trials to evaluate efficacy, toxicity, and discuss future directions.

Plasmodium carmelinoi n. sp. (Haemosporida: Plasmodiidae) of the lizard Ameiva ameiva (Squamata: Teiidae) in Amazonian Brazil.

Plasmodium carmelinoi n. sp. is described in the teiid lizard Ameiva ameiva from north Brazil. Following entry of the merozoites into the erythrocyte, the young, uninucleated trophozoites are at first tear-shaped and already possess a large vacuole: with growth, they may assume an irregular shape, but eventually become spherical or broadly ovoid. The vacuole reduces the cytoplasm of the parasite to a narrow peripheral band in which nuclear division produces a schizont with 8-12 nuclei. At first the dark, brownish-black pigment granules are restricted to this rim of cytoplasm but latterly become conspicuously concentrated within the vacuole. The mature schizonts are spherical to ovoid and predominantly polar in their position in the erythrocyte. They average 5.4 x 4,9 microm (4.4 x 4.4 - 6.6 x 5,9 microm), shape index 1.1, n = 50: 8-12 merozoites are produced and measure approximately 2.0 x 1,0 microm. Mature gametocytes are also polar in position, and spherical to subspherical. The macrogametocytes measure 5.7 x 5,2 microm (4.4 x 4.0- 5.9 x 5,1 microm), shape index 1.1, n = 50 and, following staining by Giemsa's method, possess a compact, pink-staining nucleus and a clear blue, faintly stained cytoplasm. Microgametocytes are slightly larger, 6.0 x 5,0 microm (5.2 x 4.4 - 6.2 x 5,2 microm), shape index 1.2, n = 45. They stain an over-all pink colour due to the dispersed nuclear chromatin. The vacuoles in both the macro- and microgametocytes are considerably smaller than those of the schizonts and of ovoid or spindle shape: they contain most of the pigment granules. The sex ratio, as seen in an inicial intense infection, was 1 male to 2.2 females. Prevalence of infection was low (5%) but, due to the very low parasitaemia which may result in a failure to detect parasites, it is probably higher than this.

Mitochondrial membrane potential after low-power laser irradiation.

We used the lipophilic cationic fluorescent dye 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethyl-benzimidazol-carbocyanine iodide (JC-1) to determine mitochondrial membrane potential (mdeltapsi) in Hep-2 cells after irradiation with low-power laser (lambda=635 nm). Through this methodology it was possible to analyze the variation on mitochondrial number and mdeltapsi, in cells irradiated for 100, 150 and 200 s with energy density of 100 mJ/cm(2). Our results show that JC-1 dye allows the identification of populations with different mitochondria morphology as well as the functionality of this organelle in the cells incubated for 1, 6 and 24 h, after irradiation with low-power laser.

Extracranial carotid artery aneurysms.

This article reviews the etiology, clinical manifestations, operative techniques, and results of management of fourteen cases of extracranial carotid artery aneurysms, operated upon in our institution between September 1990 and August 1994. Except for one, they were elective operations. Aneurysmectomy with restoration of continuity by direct anastomosis was done in four cases, an autogenous saphenous vein graft was performed in one, and prosthetic grafts (Dacron) in three. Local conditions precluded restoration of arterial continuity in two cases. Two patients underwent exclusion and bypass graft, and one underwent exclusion only. Ligation was resorted to in one patient, who was subjected to emergency surgery due to rupture of the aneurysm. A temporary, intra-operative, extraluminal carotid artery shunt was used in only one patient, as all the others had angiographic evidence of satisfactory cerebral cross-circulation. Two patients developed transient, neurological deficits in the post-operative period. There was no mortality. We conclude that aneurysms of the extracranial carotid arteries can be operated on with minimal morbidity and no mortality. Operative management is the treatment of choice because of their potential neurological complications, if left untreated.

Right atrial lipoma. Case report.

The authors report the successful excision of a right atrial lipoma in an adult male. The rarity of this lesion, clues to diagnosis and its management are discussed.

Intramuscular pentamidine for the prevention of Pneumocystis carinii pneumonia in patients infected with human immunodeficiency virus.

We retrospectively reviewed the charts of 96 patients infected with human immunodeficiency virus (HIV) who received intramuscular pentamidine for the prevention of Pneumocystis carinii pneumonia (PCP). These patients, all of whom had either a history of PCP or a CD4 lymphocyte count of < or = 0.2 x 10(9)/L, were intolerant of sulfa drugs, neutropenic, or intolerant of aerosolized treatment. Intramuscular pentamidine was given monthly by the Z-track technique at a dosage of 300 mg (4 mg/kg if the patient weighed < 50 kg). During a total of 350 months of primary prophylaxis in 47 patients and 426 months of secondary prophylaxis in 49 patients, only three cases of PCP occurred. More than 73% of the patients were receiving zidovudine concomitantly. Adverse reactions to intramuscular pentamidine included two episodes of hypotension, three of sterile abscess, two of glucose intolerance, and one of asymptomatic hypoglycemia. The administration of intramuscular pentamidine by the Z-track technique for PCP prophylaxis appears to be highly effective and minimally toxic.

Prognosis in occult thymomas in myasthenia gravis following transcervical thymectomy.

Thymomas were noted in 239 (11%) of 2097 myasthenic patients followed up at our institution. Among 996 patients who had undergone thymectomy, 191 patients (19%) had thymomas compared with 48 (4%) of 1101 patients treated without surgery. A definitive diagnosis of thymoma was not made until after thymectomy in 61 patients (35%); in patients not treated with thymectomy, 23% of associated tumors were diagnosed at autopsy. Patients with occult thymomas treated with the transcervical approach had a clinical course superior to those with tumors diagnosed prior to surgery and treated with the transsternal approach. Most of the advantage could be attributed to the association of occult thymomas with small tumor size and to the association of the latter with absence of invasiveness. Small tumor size was significantly associated with higher remission and lower mortality as shown in a proportional hazards analysis. Occult thymomas were accessible through the transcervical approach, with some operations necessitating a complementary mediastinotomy. Thymectomy, through the transcervical approach if technically feasible, is of benefit to all patients, has minimal morbidity, and should be performed early in the course of the disease as a diagnostic and therapeutic intervention since the risk of occult thymomas in patients with myasthenia gravis is high.

Clinical experience in more than 2000 patients with myasthenia gravis.

The vast strides in terms of pathophysiologic understanding which have been made in the past 25 years of research in myasthenia gravis are remarkable. This period of time has also seen the evolution of many applicable technological advances to better our care of these patients. Myasthenia's place in the autoimmune family of diseases has been demonstrated. No clear-cut strategy resulting from these discoveries has, however, been more than one of temporary relief or clinical improvement. In our center over these years the performance of early thymectomy in all cases of generalized myasthenia seems to be the one demonstrably reliable technique available. The effect of this procedure on coexisting neoplasia and other autoimmune disease suggests continuing avenues of investigation.

Case report: Thymectomy-induced remission of acquired autoimmune hemolytic anemia in an adult with myasthenia gravis.

A 57-year-old woman with diabetes mellitus, hypothyroidism, idiopathic thrombocytopenic purpura, myasthenia gravis, systemic lupus erythematosus, atopy, and basal cell cancer of the skin developed a severe Coombs'-positive autoimmune hemolytic anemia which was resistant to treatment with large doses of azathioprine, cytoxan, and prednisone. One year after transcervical thymectomy the hemolytic anemia disappeared and the patient has maintained a normal hemoglobin and negative Coombs' test without immunosuppressants even since. We believe this case report to be the first recorded instance of thymectomy-induced remission of autoimmune hemolytic anemia in an adult.

Scanning electron microscopy of epithelial cells grown on enamel, glass and implant materials.

The purpose of the present study was to examine with scanning electron microscopy gingival epithelial cells grown in cell culture on tooth enamel, glass, Vitallium, titanium and vitreous carbon. SGL (Smulow-Glickman) gingival epithelial cells were grown for 5 days and processed using a critical point drying apparatus. Scanning electron microscopy carried out at X 1500 magnification revealed that the gingival epithelial cells gres equally well on all materials on either smooth or rough (sand-blasted) surfaces.

Left ventricular myxoma: echocardiographic diagnosis and review of the literature.

A 33 year old man with the findings of mild aortic stenosis had an echocardiographic diagnosis of left ventricular myxoma prolapsing through the aortic valve during each ventricular systole. The M-mode echocardiogram, B-scan ultrasonogram and angiograms of this patient are presented. The clinical characteristics in all the reported cases of left ventricular myxomas are reviewed.

Evidence favoring the use of anticoagulants in the hospital phase of acute myocardial infarction.

Since the last comprehensive review of anticoagulation in acute myocardial infarction four additional randomized control trials have been reported. The overwhelming majority of all trials favored anticoagulation. Rates of thromboembolism were higher in the control, and hemorrhagic complications in the anticoagulated group. Pooling of all randomized control trials gives mean case fatality rates of 19.6% for the control and 15.4% for the anticoagulated group, a relative reduction of 21% (P less than 0.05 or less than 0.001, depending on the analytic method). Five of six randomized control trials reported "no effect" because the difference favoring anticoagulation was not statistically significant. However, sample sizes in these "negative" papers were too small to protect against missing a 21% reduction in true case fatality rate due to anticoagulation (beta greater than 0.10). All patients who present no specific contraindication should receive anticoagulants during hospitalization for infarction.

Ventricular electrical instability in the conscious dog: effects of psychologic stress and beta adrenergic blockade.

The effect of psychologic stress on cardiac vulnerability was examined in 10 conscious dogs. The repetitive extrasystole threshold was employed as a measure of susceptibility to ventricular fibrillation. Instrumental aversive conditioning constituted a stressful environment. The repetitive extrasystole threshold decreased by nearly 50 percent during 3 days in which the animals were exposed to the stressful environment. When Tolamolol hydrochloride, a cardioselective beta adrenoceptor blocking agent, was administered before a stress session, the repetitive extrasystole threshold was unaltered from the control value. Thus, stress-evoked changes in cardiac vulnerability are mediated through the sympathetic nervous system.