A validation of the Defence Mechanism Inventory

The Defence Mechanism Inventory (Gleser & Ihilevich, 1969) was validated by examining the 16PF profiles of each group of defenders. These were found to correspond closely to profiles hypothesized on the basis of Freudian theory, and thus suggest that the test may be valid. The ipsative scoring system was thought to limit the clinical usefulness of the five scales and to hinder statistical analyses, and the development of a rating form of the questionnaire was recommended.

A computer-assisted surgical pathology system

SURPATH is a comprehensive, integrated computer-assisted system for service, research, and management in surgical pathology that has been in use at New England Medical Center (NEMC) since July 1, 1978. Functions of the system include: maintenance of patient-name and diagnostic files; generation, editing, and printing of preliminary and final specimen reports; SNOMED coding and indexing of diagnoses; retrieval and video display or printing of data on individual cases or groups of cases; billing and generation of billing reports; and, calculation of intervals between accession and signout of specimens. Use of the system has greatly facilitated the production of surgical pathology reports; increased the spread with which inquiries about individual specimens can be answered; provided rapid, accurate searches of the diagnostic files; improved timeliness, accuracy, and completeness of billing resulting in increased departmental revenue; reduced intervals between accession and reporting; and, improved the morale of the professional and support staffs.

The role of leucine in ketogenesis in starved rats

The quantitative significance of the conversion in vivo of L-[U-14C]leucine to ketone bodies was determined in rats starved for 3 or 48 h. In animals starved for 3 h, 4.4% of ketone-body carbon is derived from the metabolism of leucine, and in rats starved for 48 h the corresponding value is 2.3%. This conversion occurs rapidly, and the specific radioactivity of ketone bodies in blood is maximal at 2 min after the intravenous injection of labelled leucine for both periods of starvation. The flux of leucine in the blood is 1.01 and 1.04 mumol/min per 100 g body wt. respectively for animals starved for 3 and 48 h. The specific radioactivity of blood ketone bodies was compared at 2 min after the injection of labelled leucine, lysine and phenylalanine. The specific radioactivity was 4-5 fold higher with leucine than with lysine or phenylalanine.

Ganglioside biosynthesis in rat liver. Characterization of UDP-N-acetylgalactosamine -- GM3 acetylgalactosaminyltransferase

UDP-N-acetylgalactosamine--GM3 acetylgalactosaminyltransferase (GM2-synthase) was studied in a Golgi-rich fraction from rat liver. Activity in a cell-free system required the presence of detergents; octyl glucoside was found to be the most effective in stimulating the enzyme. Optimal activity of GM2-synthase was obtained at pH 7.2, in the presence of 0.8% octyl glucoside, 10 mM Mn2+ and 5 mM CDP-choline. The latter was used to counteract the rapid sugar nucleotide hydrolysis caused by a nucleotide pyrophosphatase activity in the Golgi fraction. The apparent Km values for UDP-N-acetylgalactosamine and added GM3 were 0.035 mM and 0.1 mM, respectively. Different results were obtained if endogenous GM3 only was used as the glycolipid acceptor. In this case, the apparent Km value for UDP-N-acetylgalactosamine was 0.18 mM and Co2+ and Fe2+ exceeded Mn2+ in activating GM2-synthase. Under optimal assay conditions and in the presence of added GM3 and 5 mM CDP-choline, the specific activity of the enriched Golgi fraction was measured to be 25-30 nmol X mg protein-1 X h-1; with endogenous GM3 as the sole glycolipid acceptor, V was calculated to be 9 nmol X mg protein-1 X h-1.

Effect of chronic reserpine administration on K+ and amylase release from the rat parotid gland

After chronic administration of reserpine, slices of the rat parotid gland incubated in vitro were found to release significantly more K+ and significantly less amylase than similar slices from untreated control animals. The extent of K+ release in the gland slices of the drug-treated animals shows no dependency on external Na+ or Ca++ and is probably enhanced because of a decreased activation of K+ uptake by the Na+-K+ pump. This effect may also involve a defective generation of cyclic GMP, which was found to enhance K+ uptake and, thus, to inhibit K+ release in control slices. The inhibition of amylase release observed after treatment with reserpine most likely results from a deficient level or utilization of the energy or nucleotide sources required for enzyme secretion, because a similar inhibition was observed in control slices after incubation in the absence of the purines inosine and adenine. These results indicate that chronic reserpine administration impairs the stimulus-secretion coupling mechanism in the rat parotid gland and results in abnormal responses from both alpha and beta adrenergic receptors.

The contribution of serum triacylglycerol to hepatic triacylglycerol turnover in the starved rat

The present study was undertaken to evaluate quantitatively the turnover of serum triacylglycerol (triglyceride) in the starved rat and to determine whether serum triacylglycerol recycled to liver contributes a significant fraction of the total hepatic triacylglycerol turnover. Serum was labelled in vitro with [3H]trioleoylglycerol (glycerol [3H]trioleate) to provide uniform labelling of all lipoprotein species. By using the curves describing disappearance of isotope from serum and its appearance in liver, rate constants for movement of triacylglycerol out of serum (0.29 min-1) and the uptake of serum triacylglycerol by liver (0.22 min-1) were calculated. The total rate of movement (flux) of triacylglycerol in these processes, the product of rate constant and serum pool size, was calculated to be 0.39 and 0.29 mg/min per 100 g body wt. respectively. A model is postulated for whole-body triacylglycerol metabolism consistent with the present data as well as most observations in the literature. From the model it can be predicted that: (1) the entire turnover of liver triacylglycerol in the starved rat can be accounted for on the basis of contributions from serum non-esterified fatty acid and serum triacylglycerol; (2) the entire turnover of the serum triacylglycerol pool can be accounted for quantitatively on the basis of contributions from intestine and liver; (3) the release rate for triacylglycerol from liver should be 0.34 to 0.35 mg/min per 100 g body wt.; (4) triacylglycerol synthesized by liver from non-esterified fatty acid of serum and by intestine can account quantitatively for the irreversible disposal rate of triacylglycerol from serum.

Rate of release of hepatic triacylglycerol into serum in the starved rat

After an intravenous injection of a pulse of [U-14C]palmitate to starved rats, the time-dependent radioactivity profiles were determined in the triacylglycerol (triglyceride) of hepatic microsomal fractions, floating fat, mitochondria and nuclei. The profile of activity in serum gave a value of 0.08 mg/min per 100 g body wt. for the irreversible disposal rate of triacylglycerol from serum. This value, combined with the previously estimated rate of movement of triacylglycerol from serum to liver, and the reported rate from intestine to serum, gave a calculated value of 0.35 mg/min per 100 g body wt. for release rate of triacylglycerol from liver to serum. The rate of release of hepatic triacylglycerol into serum was also measured by the widely used Triton WR-1339 method. The rate obtained with this technique (0.15 mg of triacylglycerol/min per 100 g body wt.) was identical with that reported previously. During the interval from 45 min to 3h after ethanol administration this rate increased to 0.18 mg/min per 100 g body wt. It was concluded that the use of Triton underestimates the true rate of movement of triacylglyerol from liver to serum.

Mathematical modeling of the head and neck response to -Gx impact accelration (minimum articulation requirements)

Data on the dynamic response of the living human head and neck to -Gx impact acceleration was analyzed. The Calspan 3-D Computer Simulator of a Motor Vehicle Crash Victim was used to provide estimates of the head and neck response to be expected for the very specific deceleration profiles simulated. Two segments connected via a pivot were used to represent the head-neck system. The monitored T1 deceleration profile was used to drive this system and the simulation head-neck response was checked for accuracy in replicating motional characteristics and trends in the response mechanism. Two head pivot locations were considered. The first was the occipital condylar point and the second was a theorized hingepoint in the head which minimized the distance from this point to the T1 anatomical coordinate system over the range of body orientations observed in the photographic data. For the two geometrical representations, a successive approximation technique was employed to analyze the resulting data. This approach initially removed all constraints to head and neck motion, and the resulting simulation results were compared to the human data. Restrictions to head and neck motion were then successively added until an adequate replication of the human data was obtained. This approach made it possible to correlate specific events, such as loading of the head-to-neck dorsiflexion limiting angle, to head deceleration profile characteristics. Results were compared to calculations obtained for eight additional subjects and proved to be in good agreement.

The effect of topically applied agents on ultraviolet erythema in guinea pigs

It has been shown previously that ultraviolet erythema (UV) is partially the result of a local release of prostaglandins. We have studied the effects of different classes of pharmacological agents applied topically to the skin of guinea pigs and have found indomethacin and pirprofen, both prostaglandin synthetase inhibitors, to be highly effective suppressors of UV erythema. Our studies appear to further substantiate that prostaglandin synthesis and release may be the primary mechanistic process in the production of erythema and that the model itself can be predictive of both therapeutic and prophylactic effects of agents against sunburn.

Quantitative analysis of metabolism of hepatic triglyceride in ethanol-treated rats

An acute intraperitoneal injection of ethanol (0.7 or 2.1g/kg body wt.) causes the reversible, dose-dependent accumulation of hepatic triglyceride in rats. By using a pulse of [14C]palmitate injected into a tail vein, it was found that ethanol (2.1g/kg)had no effect on the flux of unesterified fatty acid of serum (4.3mumol/min per 100g body wt.). However, either dose increased the fraction of the total flux going to liver from 0.16 to0.27 as rapidly as could be measured (30s), and it remained elevated until all ethanol had been cleared from the blood. The fraction of the total radioactivity in lipids of liver that was in triglyceride increased linearly for 1 h from 30 to 50% and there was a simultaneous decrease in phospholipid from 60 to 40%. The rate of synthesis of hepatic triglyceride derived directly from unesterified fatty acid of serum was calculated by using the flux rate of unesterified fatty acid in serum, the fractional hepatic uptake of this flux, and the percentage of liver fatty acid esterified to triglyceride. This contribution is related to the total synthetic rate of hepatic triglyceride (rate of accumulation+rate of release) to determine quantitatively how much of the developing fatty liver is attributable to increased uptake of unesterfied fatty acid of serum. At the higher dose of ethanol, about half of the accumulating triglyceride is derived from this source, whereas with the lower dose of ethanol it can account for all of the build-up.

Mechanism of increased hepatic uptake of unesterified fatty acid from serum of ethanol-treated rats

Studies were made on the mechanism by which livers of ethanol-treated rats take up an increased fraction of the total flux of unesterified fatty acid in serum. It was found that ethanol (0.7g/kg) causes a twofold rise in the serum content of liver, and that this serum is in rapid equilibrium with the general circulation. The fractional hepatic uptake from serum of group of compounds with varying uptake mechanisms and metabolic fates was studied in control and ethanol-treated animals. All the compounds tested, including unesterified fatty acid, showed an enhanced uptake when ethanol was given. For one of the compounds, carbon tetrachloride, a dose/response relationship was established between the amount administered, the amount taken up by liver, and the amount metabolized. These findings were interpreted to mean that this dose of ethanol causes the liver to receive an increased flow of blood, and as a result all compounds present and capable of being taken by liver are taken up at an increased rate. Hepatic blood flow was measured by a technique that monitors the rate of clearance of a colloidal lipid emulsion. It was found that ethanol increased hepatic blood flow by about 60%. This effect of ethanol on hepatic blood flow provides an explanation for the fatty liver and the synergistic effect between an acute dose of ethanol and carbon tetrachloride. A hypothesis to explain why a moderate dose of ethanol causes triglyceride to accumulate in liver is presented.

Resuscitation teaching room in a district general hospital: concept and practice

Practical training in cardiopulmonary resuscitation presents a problem because of the shortage of teacher time and the many potential trainees. A resuscitation teaching room in district general hospital has been established, equipped with training mannikins and models, together with wall diagrams and cassette recordings. The arrangement enables many trainees to gain training in small groups with minimal demand on teachers. Experience with the room in use has suggested that the concept may have an application in many district general hospitals and possibly also in large industrial concerns.

Interaction of Vibrio cholerae toxin with sarcoma 180 cell membranes

Three discrete phases are discernible in the activation, by Vibrio cholerae toxin, of adenylate cyclase in fragments of sarcoma 180 cell membranes. In the first, or preparatory, phase the toxin must be exposed to dithiothreitol or nicotinamide adenine dinucleotide (NAD) in the absence of the membranes. In the second phase, the prepared toxin is dissociated to yield a macromolecular cyclase-activating factor (MCAF) in the presence of the membranes. In the third phase, membrane basal adenylate cyclase is activated by MCAF in the presence of NAD. The integrity of the catecholamine or beta-receptor associated with sarcoma adenylate cyclase is irrelevant in the activation of cyclase by MCAF. This activation proceeds undiminished even if the beta-receptor is desensitized or blocked by propranolol.