Isolation of a protein labeled with diisopropyl fluorophosphate on stimulation of polymorphonuclear leukocytes with immune complexes

As demonstrated by others, diisopropyl fluorophosphate (DFP) markedly inhibits the O2- generation from guinea-pig polymorphonuclear leukocytes (PMN) stimulated by an antibody complex with ovalbumin (Ag-Ab complex), and also the intracellular uptake of antibody-sensitized erythrocytes by the cells. However, when PMN were treated with DFP and washed to remove the inhibitor, they again became able to exhibit the O2- -generating and phagocytic activities. The [3H]DFP-labeling of intact PMN followed by solubilization with Triton N101, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed the existence of several [3H]DFP-labeled proteins with different mol. wts, which disappeared on pretreatment of cells with cold DFP. However, stimulation of DFP-pretreated PMN with Ag-Ab complex in the presence of [3H]DFP resulted in the appearance of a [3H]DFP-labeled, membrane-bound protein with a mol. wt of 40,000. This protein was isolated by affinity chromatography of the solubilized PMN and phagosomes on anti-Ig antibody-Sepharose 4B. Although the enzymatic properties of the protein are not clear, the results so far obtained suggest that it is a putative, stimulus-activated serine protease participating in the triggering events leading to the activation of NADPH oxidase responsible for the respiratory burst and the formation of phagosomes.     

Influenza virus overcomes apoptosis by rapid multiplication

The kinetics of apoptotic fragmentation of the chromosomal DNA was determined in the influenza virus-infected MDCK, HeLa and KB cells, respectively. Comparison of these kinetics with the kinetics of virus multiplication revealed that the multiplication of influenza virus was observed only when apoptosis was induced after the production of progeny virus in the infected cells. The extent of apoptotic response was reversely correlated with the permissiveness of the cells.     

Prevention of hypertensive crisis with ATP during anesthesia for pheochromcytoma

In the anesthetic management of five patients undergoing excision of pheochromocytoma, adenosine triphosphate (ATP) was used for the purpose of regulating systemic arterial pressure during the period of tumor manipulation. ATP was administered at doses of 0.05–0.4mg/kg/min. Systemic arterial pressure showed a significant decrease from 162 ± 17/103 ± 11mmHg before manipulation to 136 ± 21/81 ± 10mmHg during the manipulation period. The plasma catecholamine levels showed significant increases in this period. Immediately after excision, the systemic arterial pressure was maintained at normal levels (118 ± 13/75 ± 16mmHg) by fluid replacement and discontinuation of ATP administration, subsequently becoming 129 ± 19/79 ± 16mmHg. The heart rate was very stable and tachycardia did not ocurr during the manipulation period. Only one arrhythmic episode ocurred in one patient. The systemic vascular resistance index was significantly lower during the manipulation period than before it. It was therefore considered that ATP was useful as an agent for controlling arterial pressue during the anesthesia for pheochromocytoma.(Murata K, Sodeyama O, Ikeda K et al.: Prevention of hypertensive crisis with ATP during anesthesia for pheochromocytoma. J Anesth 1: 162–167, 1987)     

Peripheral low-density area of hepatic tumors: CT-pathologic correlation

To aid in the distinction between colorectal cancer metastasis to the liver and hepatocellular carcinoma, findings on computed tomographic (CT) scans taken more than 5 minutes after contrast material administration ("late-enhanced CT scans") and pathologic findings were compared. Late-enhanced CT scans of metastatic adenocarcinoma showed a peripheral low-density area (PLDA) that corresponded to viable tumor and a central high-density area that represented fibrous connective tissue. This phenomenon was recognized in 15 of 20 (75%) patients with metastatic adenocarcinoma and in one of 50 (2%) patients with hepatocellular carcinoma. Late-enhanced CT scans may be useful in distinguishing between metastatic nonmucinous colorectal cancer and hepatocellular carcinoma.     

Modified technique for Handsewn anastomosis following abdominoperineal pull-through operation

A modified technique for handsewn anastomosis after abdominoperineal pull-through resection is described. The technique is a continuous locked modification of the Gambee suture. Simplicity, rapidity, reliability, and firmness are the advantages of this technique.     

Neurons in the temporal cortex changed their preferred direction of motion dependent on shape

To investigate neuronal mechanisms that integrate different visual modalities such as motion and shape, neuronal activities in the superior temporal polysensory area (STP) were recorded from monkeys that were watching rotating images. In total, 194 neurons were identified as visually responsive. Of these, 73 neurons (38%) showed differential response depending on both shape and direction of motion (MS neurons). Of these 73 neurons, 21 (29%) were identified as reversal type MS neurons (MSr neurons), that is, they responded to an opposite preferred direction when the shape was different. The results confirm that neurons in the STP can be simultaneously activated by different attributes of visual stimuli. The data also suggest that individual STP neurons can process more than one type of visual stimulus.     

Novel experimental model using free radical-induced emesis for surveying anti-emetic compounds from natural sources.

A novel experimental model of free radical-induced emesis for screening anti-emetic compounds from natural sources was established. 2,2'-Azobis(2-amidinopropane) dihydrochloride (AAPH) dissolved in liposome induced emesis in young chickens, and the emesis was prevented by antioxidants including N-(2-mercaptopropionyl)-glycine (MPG), alpha-tocopherol, and L-ascorbic acid. Tropiseton, a serotonin receptor antagonist, also prevented emesis induced by AAPH. Known anti-emetic drugs and anti-emetic principles from natural sources also showed significant retching inhibition in the experiment using this system.     

Purification and Partial Characterization of an Indomethacin Hydrolyzing Enzyme from Pig Liver

Purpose. Indomethacin is well known to be metabolized via O-demethylation and N-deacylation. In this paper we found an enzyme involved in the hydrolysis of amide-linkage of indomethacin and partially characterized it as well as its substrate specificity. Methods. An indomethacin hydrolyzing enzyme was purified to homogeneity from pig liver microsomes using columns of Q-Sepharose, Red-Sepharose and Blue-Sepharose. The enzyme activity was assayed by measuring of -chlorobenzoic acid liberated from indomethacin by HPLC. Results. The purified enzyme effectively hydrolyzed the amide linkage in indomethacin but not those in -naphthylacetate and -nitrophenylacetate, which are typical substrates for carboxylesterase. The subunit molecular mass of the enzyme was 65 kDa according SDS-polyacrylamide gel electrophoresis. The Michaelis constant (Km) and maximum velocity (Vmax) values for indomethacin were 67.8 µM and 9.02 nmol/min/mg protein, respectively. The amino acid sequence analysis of the enzyme after cyanogen bromide cleavage showed high homology with a mouse carboxylesterase isozyme designated as ES-male. The activity of indomethacin hydrolysis was relatively high in the pig, rabbit and human liver homogenate, but not in those from rat and mouse. On the other hand, purified human liver carboxylesterases pl 5.3 and 4.5, and pig liver carboxylesterases have no catalytic activity for indomethacin. Conclusions. These results indicate that the hydrolysis of amide-linkage of indomethacin in humans would be associated with an enzyme similar to the indomethacin hydrolyzing enzyme from pig liver microsomes described here.