Choice of x-ray diagnostic methods in chronic odontogenic sinusitis

On the basis of our experiences the selection of diagnostic methods for chronic odontogenic sinusitis is discussed. The selection is based on the primary sign, the reduced transparency of the sinus, detected with conventional radiography. Its purpose is the determination of the extent and nature of the opacity. Conventional methods, contrast investigations, conventional and computed tomography are used.     

CT tomography of normal parotid and mandibular salivary glands

Computed tomography (CT) allows the differentiation of tissues by measurement of their roentgenologic densities. There are a few controversial literature data on the roentgenologic densities of the parotid and submandibular glands. These differences are, in our opinion, due to several factors: 1. The complex anatomic structure of the facial region of the skull, that demands an exact centering. In daily practice the respective imaging parameters are not always kept constant (including partial volume effects), thus introducing density errors. 2. Metallic prostheses and obturators as well as the high-density bones of the facial skull cause artefacts that impair image quality and density measurements. 3. The small density differences between the salivary glands and the adjacent soft tissues makes their differentiation difficult. 4. Different devices and parameters are used for scanning, resulting in different densities. Considering these facts, we have devised a complex method for the investigation of the parotid and mandibular salivary glands.     

Abrogation of adriamycin-induced cardiotoxicity by selenium in rabbits.

Adriamycin-induced cardiomyopathy in rabbits was produced by intravenous injections of the drug with a short therapeutic schedule (3 mg/kg body wt administered as four intermittent doses). Animals receiving selenium supplementation of Adriamycin showed preservation of the normal pattern of the heart histologic picture. The protective effect of selenium was accompanied by increased selenium levels in the plasma and the heart muscle. An eventual interaction between the antitumor effect of Adriamycin and the protective effect of selenium was ruled out by in vitro experiments using the L1210 cell line. Selenium did not abrogate the antiproliferative effect of Adriamycin when the cells were treated simultaneously with both agents. The results from this study indicate that Adriamycin-induced cardiotoxicity could be prevented by selenium if the animals were pretreated with selenium, rather than simultaneous administration of both agents. The mechanism of this effect is not entirely understood.     

Calculation of extracellular potentials produced by an inclined muscle fibre at a rectangular plate electrode

Generally the anatomy of muscles is rather complex, and the fibres have various inclination angles within the muscles. We suggest a fast and reliable way to calculate extracellular potentials produced at a point or rectangular plate electrode by a muscle fibre of finite length with an arbitrary inclination. A muscle fibre was considered to be a linear timeshift-invariant system of potential generation. Then, similar to the fibre without inclination, the extracellular potential produced by an inclined fibre was represented as the output signal of the system; it was calculated as the convolution of the input signal and impulse response. Irrespective of the inclination, the input signal of the system was the first temporal derivative of the intracellular action potential. The impulse response of the system differed for the fibres with inclination. This required a new method of analytical integration over the rectangular electrode area. The approach provides a chance to simulate and analyze motor unit potentials or F-, H- or M-responses produced by muscles of complicated anatomy (circum-pennate or complex pennate type) at electrodes of actual size and location in normals and patients with neuro-muscular disorders.     

Anatomical basis for pressure on the common peroneal nerve

An attempt was made to explain the anatomical basis for the pressure on the common peroneal nerve which may lead to loss of sensation and "foot drop". By using available cadavers during routine dissections, it was observed that the attachments of the peroneus longus muscle on the head of the fibula are, in most cases, tendinous, and blended with the crural fascia and lateral (fibular) ligament, thereby, forming an inelastic band arching over the common peroneal nerve. In some other cases, the reflected fibres of the biceps femoris tendon, anterior tibiofibular ligament and iliotibial tract constituted a fibrous bridge over the nerve. The least occurrence was that of the nerve piercing the thick and inelastic anterior crural septum.     

Influence of measurement inaccuracies on determination of left ventricular mass by M mode echocardiography.

OBJECTIVE: To determine to what extent inaccuracies in measuring the end diastolic diameter of the left ventricle, the interventricular septum, and the posterior wall, by M mode echocardiography influence the left ventricular mass calculated by the Devereux's formula. DESIGN: Mathematical model. RESULTS: Relatively small measurement inaccuracies such as 5%, which are known to be inherent in the echocardiographic method, will result in "changes" of left ventricular mass in the range of 8% to 15%. This is equivalent to expected changes in left ventricular mass seen during treatment. CONCLUSIONS: The use of Devereux's formula to calculate left ventricular mass is limited by measurement inaccuracies in individual patients.     

Haemoptysis in healthy children due to unsuspected foreign body

Abstract: Haemoptysis in otherwise healthy children is an uncommon event. Two cases of massive haemoptysis, subsequently requiring lobectomy, are discussed. In each case, foreign vegetable matter was identified despite previously normal bronchoscopy and minimal changes on chest radiograph.