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Biomedical subjects

C T Lee

Publications and source records attributed to C T Lee.

At least 145 records · Page 8Linked to original sources
PubMed1982

beta-Glucuronidase activation of latent aggression-promoting cues in mouse bladder urine.

The present study was designed to investigate the chemical properties of the aggression-promoting cues present in bladder urine of male mice. The results of the first experiment confirmed earlier work by demonstrating the presence of an aggression-promoting chemosignal in bladder urine. In Experiment 2, behavioral assays were separately performed on the organic and aqueous layers of bladder urine obtained by repeated dichloromethane extractions. Only the combined organic layers of the initial three extractions demonstrated behavioral activity. A fourth extraction showed no behavioral activity for both organic and aqueous layers. However, the findings of Experiment 3 showed that incubation of the aqueous layer from the third CH2Cl2 extraction in beta-glucuronidase can free additional aggression-promoting cues into a subsequent CH2Cl2 extraction. It is concluded that two forms of the aggression-promoting chemosignal are present in bladder urine. One is lipophilic and behaviorally active, whereas the other is conjugated, possessing latent chemosignal properties.

Aggression↗
PubMed1981

Elastolytic activity in pulmonary lavage fluid from patients with adult respiratory-distress syndrome.

To test the hypothesis that adult respiratory-distress syndrome (ARDS) is related to increased activity of the proteolytic enzyme elastase released from neutrophils in the lung, we determined the differential white-cell count, the elastolytic activity, the source of elastase, and the concentration and activity of the endogenous protease inhibitor alpha-1-antiprotease (alpha-1-AP) in bronchoalveolar lavage fluid from 23 patients with ARDS and from 55 patients without this syndrome. Neutrophil predominance (> 80 per cent) was observed in 18 of 23 patients with ARDS. High elastolytic activity of neutrophil origin was found in 12 of 23 patients with ARDS (52 per cent), in none of 16 normal nonsmokers (P < 0.01), in two of 17 normal smokers, and in three of 22 patients with chronic obstructive pulmonary disease. Although there were no significant differences in alpha-1-AP concentrations, its activity was reduced in eight of nine patients with ARDS and high elastolytic activity. We conclude that in many patients with ARDS, high levels of neutrophil elastolytic activity in the lungs are associated with reduced alpha-1-AP function.

Aged↗
PubMed1981

A double-blind comparison of nomifensine and amitriptyline in the treatment of depression.

A double-blind study was carried out to compare the efficacy and tolerability of nomifensine and amitriptyline in 17 Malaysian patients with moderate to severe depression. The two drugs did not differ with regard to antidepressant effect but nomifensine-treated subjects report fewer side-effects with no complaints of palpitations. Nomifensine also increases capacity for work and activity.

Adult↗
PubMed1979

Social chemosignals in five Belontiidae (Pisces) species.

Approach behaviors toward conspecific chemical stimuli of the opposite sex were examined in five Belontiidae species: Betta splendens, Macropodus opercularis, Colisa labiosa, C. lalia, and Trichogaster trichopterus. Approach was measured by (a) preference for section 1 of a three-section tank, which contained a vertical tube that introduced the stimulus water, and (b) occupancy of the tube. Experiments 1A and 1B showed that (a) approach behaviors were displayed by the isolated male Betta only to ripe-female stimulus water, (b) group-housed males of the remaining four species were not attracted to female-conditioned water, and (c) socially isolated males of these four species preferred section 1 during presentation of either ripe- or nonripe-female-inhabited water but occupied the tube only during exposure to ripe-female-conditioned water. The findings of Experiment 2A were that (a) the female Betta, regarless of physiological state, showed approach behaviors to male-inhabited water and (b) only ripe females of the remaining species indicated a preference for section 1 during male-water exposure but performed no tube entries. Results of Experiment 2B indicated that social isolation of the females, especially ripe females, facilitated their approach behaviors.

Animals↗
PubMed1976

A new method for the determination of alpha1-protease inhibitor (alpha1-antitrypsin) phenotypes based on the formation of alpha1-protease inhibitor allele product-elastase complexes.

Up until now it has been assumed that the protease-binding property of alpha1-protease inhibitor (alpha1PI) was destroyed by acid starch gel electrophoresis (pH 4.9). Analyses on acid starch gel blocks for pH and conductivity changes during and following a typical electrophoretic run showed that it was unlikely that the separating alpha1PI would be exposed to pH values lower than 6.2, and that the allele products, following the passage of the buffer front, were in an environment of constant pH(6.3), extremely low conductivity and high field strength. These results strongly suggested the likelihood that alpha1-PI would be chemically and physically unchanged as a result of exposure to acid starch gel electrophoresis. In order to test this likelihood, human serum was electrophoretically separated in acid starch gel and following electrophoresis, was immersed in 0.1 M diethylbarbiturate buffer, pH 8.6, containing 20 mug/ml of pancreatic elastase. The pH-adjusted (8.15) and elastase-impregnated starch gel layer was superimposed on hemoglobin-agar for 2.5 h at 37 degrees C followed by immersion of the hemoglobin-agar layer in 1% NaCl overnight, distilled water for 2 h, drying under filter paper and staining. The results showed zones of undigested hemoglobin indicating, unequivocally, that the separated alpha1PI allele products are capable of forming complexes with proteases and that alpha1PI is not inactivated following exposure to acid starch gel electrophoresis. Densitometric analysis of the transparent stained zones on a clear agar gel background offers an alternative to analysis of the acid starch gel-separated zones by antigen-antibody crossed electrophoresis and as such is suitable for identification of alpha1-protease inhibitor phenotypes. Further, the method is specific for alpha1PI and a densitometric scan provides direct information relative to the protease-binding capacity of the sample as well as the contribution of each alpha1PI allele product to that capacity.

Alleles↗