Fracture of the genial tubercles associated with a mandibular denture: a clinical report and review of the literature.

We report a case of fractured genial tubercles associated with a mandibular denture in an elderly female patient and review the literature reports of this condition over the past 50 years. The period without natural teeth and the amount of atrophy of the mandible appear to be associated with the condition, especially when atrophy has reached an extent where the genial tubercles become a direct part of the denture bearing area. The signs and symptoms generally associated with this condition include pain and swelling, haematoma of the floor of the mouth, painful and limited movement of the tongue, dysphagia and painful swallowing, and an obvious experience of discomfort while wearing the lower denture. The radiographic assessment of the mid-line region of the face on conventional radiograph views is often complicated by superimposition of the spine, and therefore computerised or cone-beam volumetric tomography will provide a better view of the fractured segment. The management of the condition is either by conservative care, or by surgical exposure and removal of the fractured tubercles. Irrespective of the chosen mode of treatment, the reports indicate that recovery can be expected to be uneventful in a relatively short period of time. Consensus suggests that the indications for surgical intervention in fractures of the genial tubercles are minimal, as the majority of patients do not require any active treatment and had resolution of their symptoms after conservative management.

Lipoma of the floor of the mouth: report of an unusually large lesion.

Although lipomas are common, benign tumours found in any part of the body, their occurrence in the oral cavity is relatively rare. An unusual case of a large lipoma appearing on the floor of the mouth in a 77-year-old male, is presented in this paper. The unusual appearance in this case suggests that this tumour should be included as a rare possibility in the differential diagnosis of swellings in the floor of the mouth.

Drug effects on cerebral blood flow in the baboon model--acetazolamide and nimodipine.

The sensitivity of the baboon model under anaesthesia for single photon emission computed tomography (SPECT) of the brain with 99mTc-HMPAO, as recently developed by us to study cerebral blood flow patterns, was investigated using drugs that are known to increase cerebral blood flow, e.g. acetazolamide, the carbonic anhydrase inhibitor and nimodipine, the calcium channel blocker. Increases in cerebral blood flow for both acetazolamide and nimodipine were observed that correspond well with other studies. Statistically significant regional specificity was noted for acetazolamide and nimodipine. Interestingly a combination of these drugs did not enhance cerebral blood flow but rather decreased it in comparison with the individual drug responses. The results were correlated with arterial blood pressure, heart rate, pCO2 and pO2. A blood pressure decrease was noted for both drugs, while acetazolamide had a marked influence on pO2. The results indicate that the baboon model is sensitive for evaluation of drug effects on cerebral blood flow.

Species and immunoglobulin preparation related effects on the biodistribution of technetium-99m-labelled immunoglobulin G in a baboon model.

Technetium-99m-labelled immunoglobulin G (99mTc-IgG) is a convenient and useful radio-pharmaceutical for the scintigraphic detection of inflammatory foci. However, unfavourable physiological biodistribution patterns such as high activities in the liver and especially in the kidneys impede the efficacy of this agent. This report describes biodistribution studies in the baboon model of various thiol reduction-mediated 99mTc-labelled immunoglobulins, including human IgG preparations (Sandoglobulin and Sigma: gamma-globulins prepared from Cohn fractions II and III) as well as baboon IgG preparations (Sigma: gamma-globulins prepared from Cohn fractions II and III and IgG isolated from the serum obtained from specific animals). The biodistribution studies demonstrated differences in kidney concentration, i.e. human IgG (Sandoglobulin) > baboon IgG (cross-over animal experiments with IgG isolated from the serum of the different animals) > human IgG (Sigma) approximately baboon IgG (Sigma) approximately baboon IgG (own IgG isolated from the serum of a specific animal, labelled with 99mTc and reinjected). Differences in liver concentration were also observed: human IgG (Sandoglobulin) < human IgG (Sigma) approximately baboon IgG (Sigma) approximately baboon IgG (own IgG) approximately IgG (cross-over). Characteristic were the relatively high activities in the liver and kidneys compared to those in other organs with high blood supply, and a relatively high retention in the blood pool.(ABSTRACT TRUNCATED AT 250 WORDS)

In vivo assessment of regional microvascular albumin leakage during E. coli septic shock in the baboon model.

Changes in regional microvascular albumin flux during septic shock were studied noninvasively by scintigraphy in the baboon model. Use was made of an i.v. injection of 99mTc-labeled baboon serum albumin. Count ratios of lung to cardiac, liver to cardiac, and abdominal to cardiac regions were measured two-hourly for 6 hr in six control and six septic shock baboons (live E. coli) and compared. Increased ratios obtained during shock pointed to an increase in extravascular albumin. Linear regression lines fitted to these count ratios provided regional albumin leak indices. These indices demonstrated statistically significant increases (P less than 0.05) during septic shock for the abdominal region during the 6-hr study, and for all regions, but especially the abdomen, when data were calculated over 4 hr. Increasing ratios and leak indices correlated with postmortem data and with changes in neutrophil and platelet behaviour previously established during shock. Possible accompanying mediator releases could be responsible for the endothelial damage leading to the increased permeability.

Cardiac function and Fourier phase data from simulated Wolff-Parkinson-White syndrome in a baboon model.

The diagnostic value of Fourier phase analysis and planar scintigraphy in Wolff-Parkinson-White (WPW) syndrome has been suspect. This study investigates phase analytical data from planar radionuclide ventriculography of six baboons with simulated WPW syndrome by means of implanted electrodes. An electrode in the atrium controlled the heart rate and a subsequent stimulation was delivered by electrodes placed at different sites on the ventricles, delayed to cause the characteristic delta wave of the WPW syndrome. Sensitivity for accurately-localizing variously-situated first points of activation (FPAs) from the Fourier phase images was found highest for premature right ventricular (RV) activation, and for atrioventricular (AV) delays around 125 msec. Other sites were subject to artifacts. Changes in cardiac function, phase delay, and histogram parameters were not statistically meaningful.

The effect of intravenous administration of melatonin on cardiovascular parameters of the baboon (Papio ursinus).

Melatonin (0.3 to 0.4 mg/kg) dissolved in 0.5 ml dimethylsulphoxide (DMSO) was injected i.v. into six baboons, and their cardiovascular parameters were monitored. Left ventricular end-diastolic and end-systolic volumes, stroke volume, cardiac output, and left ventricular ejection fraction were measured, using conventional radionuclide ventriculography, and compared to normal values previously established. These parameters were also measured after an i.v. administration of only DMSO. The only statistical significant change due to melatonin was the increase in the cardiac output and left ventricular ejection fraction. With the reduced heart rate the increase in cardiac output implies a positive inotropic action on the heart by melatonin. There are indications that DMSO possibly suppresses cardiovascular actions of melatonin.

Thiol reduction-mediated 99mTc-IgG for scintigraphy of inflammatory lesions in the baboon model.

Radiolabeling procedures may modify the structure of the Fc portion of the immunoglobulin molecule in such a way that its in vivo immunological behavior may be altered and its efficacy as radiopharmaceutical for inflammatory lesions impaired. This study tested the efficacy of thiol reduction-mediated 99mTc human IgG for scintigraphy of focal inflammatory lesions, either bacterially or chemically induced and located either in the abdominal/thoracical region or in the thigh of baboons. Positive images were obtained in the thigh lesions between 4 and 7 hr after i.v. administration of the labeled IgG. The abdominal/thoracic lesions were never very clear, mostly because of very hot kidneys. Late visualization (20 hr) of all lesions was poor and a high background was present. Bacterially induced lesions were better visible, although no neutrophil nor monocyte activity could be established in the mechanism of the IgG localization.