Intraoral reconstruction in head and neck cancer surgery

The effect of prostaglandins (PGs) on the hepatic biotransformation of hexobarbital (Hechi) and p-chloro-N-methylaniline (PCMA) was determined in male rats. PCMA metabolism in slices was decreased by all PGs (PGA1, PGB1, PGE1, PGE2, PGF1alpha, PGF2alpha), ranging in concentration from 1 mu M to 1 mM. PGA1, at 1 mM, produced the greatest degree of inhibition, 39%. PG addition to microsomes, however, failed to alter PCMA metabolism. In contrast to PCMA biotransformation, Hechi metabolism was increased by all PGs in slices but not in liver subfractions. PGs of the E and F series were the most potent, producing a two-fold increase in Hechi metabolism at 1 mM after a 20 min preincubation. The increased effect was observed as early as 10 min and lasted for 4 hr. The relationship of PG metabolism and binding to cytochrome P-450 is presented as a possible mechanism to account for the opposite effects on Hechi and PCMA, type I and II substrates respectively, metabolism.     

An approach to general oncology: principles and procedures

53 patients clinically suspected of having a cerebellopontine angle (CPA) lesion were examined by computer tomography (CT) with 160 X 160 matrix EMI scanner. 17 cases (32%) had tumour positive CT, of which 12 were neurinomas and 1 meningioma. 1 CT suggestive of a CPA lesion was false positive and 1 unoperated case is probably a false negative CT. Three of the eleven verified neurinomas (27%) were of the medial type originating in the angle cistern. One neurinoma protruding 1 cm into the cistern showed no contrast enhancement. 2 CT scans (3.8%) were unsatisfactory due to movements and the large size of the head. CT is valuable for the investigation of CPA pathology and the diagnostic efficiency compares favourably to other neuroradiological procedures.     

Amplified migration inhibition effect

Upon exposure to specific antigen in tissue culture, sensitive lymphocytes released macrophage migration inhibition factor and other lymphokines into the supernatant culture medium. Migration of peritoneal macrophages from nonsensitive animals was inhibited in the presence of such supernatants. However, with previous techniques it was found that an inhibitory effect was present at only low low titers (less than 10(2)). It is therfore of great interest that by increasing cellular density, the total number of cells being kept constant, inhibitory activity can be amplified by a factor as great as 10(10). This amplification was observed only when lymphocytes and macrophages were loosely packed, as by spontaneous sedimentation in a conical test tube. The effect was abolished by dispersing the cell suspension in a flat-bottomed flask or, alternatively, by shaking the test tube so that intimate prolonged intercellular contact was prevented.     

Retroperitoneal germinoma marked by elevated serum lactic dehydrogenase

A case of primary retroperitoneal germinoma is presented in which markedly elevated serum lactic dehydrogenase levels were present before diagnosis, but declined to normal with abdominal irradiation. It is the first report of lactic dehydrogenase serving as a tumor marker in germinoma.     

Contraindications to the repositioning of fractured or dislocated limbs in the fields

Supracondylar fractures of the femor or humerus and fractures of the radius, ulna, tibia or fibula, plus crush injuries of the limbs, most likely should not be manipulated in the field because of the potential for traumatizing adjacent nerves, veins and arteries. An emergency splinting system that allows immobilization without repositioning has been developed. Furthermore, fractures in or about the elbow, wrist, knee, or ankle should not be subjected to reduction in the field, unless there are compelling reasons to justify the risk of producing significant additional trauma. Conservative immobilization without repositioning may yield a more positive prognosis for the patient.     

Oxygen-hemoglobin equilibrium of normal and glutathione-deficient sheep

Ten patients with severe liver disease and the hepatorenal syndrome underwent exchange transfusions with 9 to 16 units of fresh heparinized blood to improve renal function by either removing a vasoconstrictive substance or adding a vasodilatory substance. One patient recovered from renal failure within ten days without showing natriuresis. The renal function of one patient improved somewhat, but he died 35 days after the transfusion. The other eight aptients died from 1 to 35 days after exchange transfusion, without any appreciable improvement in renal function. In six patients, renin substrate levels increased after the transfusion, but renal function remained unchanged. The results of this study failed to support a humoral concept of pathogenesis of the hepatorenal syndrome.     

The systemic arterial pattern of the guinea pig: the pelvis and pelvic limb

The changes of heart rate in response to i.v. administration of methylatropine (0.5 mg/kg) and/or propranolol (2 mg/Kg) or practolol (2.5 mg/Kg) were studied in conscious trained dogs. Cholinergic blockade alone or combined blockade of sympathetic and parasympathetic effector systems resulted in cardiac acceleration. Conversely, beta-adrenoceptor antagonism with either propranolol or practolol reduced heart rate. The data were analysed by means of a new method, whereby the heart (HRN) of the dog is considered to be the product of the intrinsic heart rate (HR0) and 3 further factors: HRN-HR0 times S times V times W (Multiplicative model). 2 of these factors represent the tonic sympathetic (S) and parasympathetic (V) influences, whereas the third (W) represents the sympathetic-parasympathetic interaction. This type of analysis reveals that W was approximately 1, i.e., the sympathetic-parasympathetic interaction did not play any significant role in determining the heart rate of conscious resting dogs (HRN = HRO-S-V-W = HRO-S-V). The change of heart rate due to the action of parasympathetic system (-53% of the intrinsic heart rate) was more important than the change caused by the action of the sympathetic system (26% of the intrinsic heart rate).