A histochemical investigation of catecholamines in spinal cord injury

The catecholamine hypothesis of progressive spinal cord necrosis following mechanical trauma was investigated with the histofluorometric method. Forty-four adult mongrel dog were examined as control, L1 crush-injured, and crush-injured with prior T1 total transection groups. In crush injured dogs, catecholamines were present in a 1 cm length of white matter at the crush site, with the greatest accumulation in the deep lateral and ventral funiculi. Gray matter fluorescence was not enhanced. Prior transection did not abolish the intense accumulation of catecholamines at the site of the cord injury. We propose that the catecholamines accumulating at the cord injured site are not central in origin, but represent an uptake mechanism into white matter as a reflection of cord microperfusion.     

Quantitation of maximal bactericidal capability in human neutrophils

The quantitative capacity of normal human neutrophils to ingest and kill increasing multiples of bacteria up to a level of saturation was evaluated. The in vitro system, a modification of classic bactericidal assay, employed carefully controlled ratios of bacteria per neutrophil between 1.25 and 400:1 to stress neutrophil function. Morphologic examination and measurement of bacterial survival by quantitative plate culturing indicated that at a challenge of about 100 Staphylococcus aureus per neutrophil bactericidal activity reached its peak with each average cell killing 48 bacteria. The efficiency of bactericidal function fell as the challenge was increased while ingestion capabilities kept pace with the numbers of bacteria presented to the neutrophils. Various key test parameters were evaluated from which evolved a system which provides a highly reproducible, statistically based, method for clinical assessment of subtle or partial neutrophil dysfunctions which may escape detection by the currently employed techniques of bactericidal assay.     

Discharges against medical advice from voluntary psychiatric units

About one in every six voluntary mental patients discharges himself against medical advice. But despite the high rate of AMA discharges, the authors found the literature on the subject to be sparse and of little help in explaining why patients leave the hospital against medical advice. They examine the approaches that have been used thus far to study the phenomenon. They also report the findings of their own study, which showed that patients discharged against medical advice had a poorer response to treatment than those discharged in the traditional manner. The study identified factors that contributed to the poor response and were related to the discharge.     

Aberrant left pulmonary artery presenting as a right paratracheal mass in an adult

Aberrant left pulmonary artery, or pulmonary sling, is a rare variation of the pulmonary vasculature, with only one previous report of the condition being recognized in an adult. In this report a second case recognized de novo in an adult is presented. Both of these adults were evaluated because of right paratracheal masses which required differentiation from pulmonary malignancies. The barium swallow shows a characteristic indentation of the anterior esophageal wall and the lateral tomogram demonstrates absence of the left pulmonary artery from its normal position in the left hilum. The pulmonary arteriogram is diagnostic and allows avoidance of more invasive diagnostic measures.     

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.