Purification and properties of a human plasma endogenous modulator for the platelet tricyclic binding/serotonin transport complex

An endogenous modulator for the site labeled by [3H]imipramine which is putatively coupled to the serotonin transporter in human platelets was isolated and purified from plasma. Procedures included sequential chromatography on Cibacron blue-Sepharose 4B, concanavalin A-Sepharose 4B, Mono Q HR 10/10 anion exchange, DuPont GF-250 gel permeation and Mono S HR 5/5 cation exchange columns. The purified modulator is a protein of Mr 45,000 with a very acidic pK (less than 3) and sensitive to various proteinases but heat- and acid-stable. This protein inhibited [3H]imipramine binding to platelet membranes competitively (IC50 approximately 6 microM) and enhanced serotonin uptake in fresh human platelets (EC50 approximately 7 microM). Various physicochemical properties, including chromatographic, electrophoretic and immunological as well as amino acid composition analysis revealed that the isolated protein is most probably the human alpha 1-acid glycoprotein.     

Hemorrhage in mice produces alterations in B cell repertoires

Multiple organ system failure secondary to infection is the major cause of late deaths after trauma and hemorrhage. The production by B cells of antibodies directed against bacterial antigens is an important component of host defenses. In order to determine the effects of hemorrhage on B cell function, we examined hemorrhage-induced alterations in available (clonal precursors) and actual (plasma cells) B cell repertoires in the course of an immune response toward bacterial antigens. Hemorrhage produced greater than twofold decreases in the absolute frequency and number of clonal precursors specific for the bacterial antigens dextran, levan, and pneumococcal polysaccharide type II. After blood loss, there were decreases in absolute frequency, but not in numbers, of clonal precursors capable of producing antibodies against the nonbacterial antigens ovalbumin and mouse transferrin. Immunization with the bacterial antigen levan within 24 hr of hemorrhage resulted in approximately 50% fewer levan-specific plasma cells than that seen in normal, unhemorrhaged mice. These results demonstrate that hemorrhage produces marked alterations in B cell repertoires, which may contribute to postinjury abnormalities in host defenses.     

Role of corpus allatum on the modulation of feeding rhythm in the semilooper caterpillar, Achaea janata (L)

A circadian feeding rhythm which may be entrained by photoperiod was found in fifth instar caterpillars of the lepidopteran, Achaea janata (L.). Allatectomy reduced the amount of food consumed; this consumption was significantly lower during the fifth instar in both allatectomized and sham-operated insects. An apparent circadian feeding pattern appeared on day 2 in the sham-operated caterpillars. Topical application of the anti-allatin, Precocene-II (50 micrograms/animal) also reduced leaf consumption significantly compared to the respective controls, although these controls maintained the same apparent circadian feeding rhythm on day 2.     

Predicting genotypes at loci for autosomal recessive disorders using linked genetic markers: application to Wilson's disease

Summary Recently, the Wilson's disease locus (WND) has been mapped to the long arm of chromosome 13. We have analyzed segregation of serveral chromosome 13 markers flanking the WND locus and used multipoint linkage analysis to determine the most likely WND genotype of each of 57 unaffected individuals in 5 Wilson's disease families. Approximately 46% of these could be classified as carrier (heterozygote), homozygous normal, or homozygous affected (not yet symptomatic) with a probability of at least 90%, while 77% could be classified with a probability of at least 80%. Our results demonstrate that even though there is a significant decrease on average in serum copper concentration in Wilson's disease heterozygotes compared to normal homozygotes, other sources of variation in serum copper concentration are much greater and preclude use of serum copper to detect heterozygotes for Wilson's disease. Subsequent analyses showed that a familial component, independent of WND genotype, is the major factor accounting for variation in ceruloplasmin levels among unaffected individuals; age is another factor accounting for more variation in copper levels among unaffected individuals than WND genotype.     

Immunochemical identification of the serine protease inhibitor alpha 1-antichymotrypsin in the brain amyloid deposits of Alzheimer's disease

Two approaches--molecular cloning and immunochemical analysis--have identified one of the components of Alzheimer's disease amyloid deposits as the serine protease inhibitor alpha 1-antichymotrypsin. An antiserum against isolated Alzheimer amyloid deposits detected immunoreactivity in normal liver. The antiserum was then used to screen a liver cDNA expression library, yielding three related clones. DNA sequence analysis showed that these clones code for alpha 1-antichymotrypsin. Antisera against purified alpha 1-antichymotrypsin stained Alzheimer amyloid deposits, both in situ and after detergent extraction from brain. The anti-amyloid antiserum recognizes at least two distinct epitopes in alpha 1-antichymotrypsin, further supporting the presence of this protein in Alzheimer amyloid deposits. In addition to being produced in the liver and released into the serum, alpha 1-antichymotrypsin is expressed in Alzheimer brain, particularly in areas that develop amyloid lesions. Models by which alpha 1-antichymotrypsin could contribute to the development of Alzheimer amyloid deposits are discussed.     

Interesterification selectivity in lipase catalyzed reactions of low molecular weight triglycerides

Summary In the absence of an organic solvent, a buffer to enzyme weight ratio of 1 gives maximum selectivity to interesterification over hydrolysis in a lipase-catalyzed mixture of triacetin and tributyrin. Addition of hexane enhances interesterification as does a reversed micelle configuration.     

Mechanism of hypercholesterolemia produced by biotin deficiency

The effect of biotin deficiency on the metabolism of cholesterol was studied in rats fed cholesterol-free and cholesterol-containing diet. Biotin deficiency induced by feeding raw egg-white resulted in higher cholesterol in the serum and aorta, and higher high density lipoprotein cholesterol and low density lipoprotein + very low density lipoprotein cholesterol. In the liver, cholesterol increased only in the cholesterol diet group but not in the cholesterol-free diet group. Levels of triglycerides were lower in the biotindeficient, cholesterol-free diet group, but triglycerides were elevated in the cholesterol diet group. Concentration of bile acids in the liver and activity of lipoprotein lipase in the heart and adipose tissue were significantly decreased in the biotin-deficient rats. Release of lipoproteins into the circulation, incorporation of [1,2-¹⁴C] acetate into cholesterol, and activity of plasma lecithin: cholesterol acyl transferase were higher.     

Active and passive immunization of mice against larval Dirofilaria immitis

The objective of this study was to determine if Dirofilaria immitis larvae would survive in diffusion chambers implanted in dogs and mice and secondly to determine if mice could be immunized against infection with D. immitis. Dirofilaria immitis third-stage larvae (L3) survived and grew in diffusion chambers implanted in dogs and mice for at least 3 wk. BALB/c mice, which were repeatedly infected with live L3, showed resistance to challenge infections. Dead L3, with or without adjuvants elicited no protective immunity. A correlation was found between the degree of immune protection seen in mice and antibody levels to soluble larval antigen but not to antibody levels to surface antigens. A monoclonal antibody was prepared that reacted with the surface of D. immitis and Onchocerca lienalis L3, but not to the surfaces of other stages and species of various filarial worms. When this antibody was administered to mice prior to challenge no significant reduction in larval survival was observed.     

Cellular responses in the skin of carp maintained in organically fertilized water

Carp were maintained for a month in well-oxygenated water fertilized with organic manure. During the experiment the thickness of the epidermis increased from 140 to 180 urn. Fish from pulluted water were dark, an adaptation to the dark, turbid water. The number of cytoplasmic extensions from the dermal pigment cells increased continuously from 6 per unit length in control specimens to over 80 in the experimental specimens at the end of the month. Apart from background adaptation, this activity of the pigment cells may be a stress reaction. Holocrine secretion of mucous cells was pronounced, with a progressive reduction on the first day after the transfer, to almost total disappearance of this cell type from the epidermis after 3 days. A thick mucous coat became visible on the outside of the epidermis. Eight days after the transfer, a slightly subnormal mucous cell count was observed, indicating the development of newly differentiated mucous cells. This subnormal cell count lasted until the end of the experiment. The pavement cells actively secreted glycocalyx, while newly differentiated pavement cells with still-intact secretory granules replaced the exhausted cells at the epidermis surface throughout the experimental period. Granulocytes, both baso- and neutrophilic, as well as macrophages, infiltrated the epidermis; despite the high bacterial count in the water, no bacteria were observed either inside the skin or entangled in the mucous coat.