Resistance of human erythrocytes containing elevated levels of vitamin E to radiation-induced hemolysis

Human erythrocytes were isolated from the blood of healthy donors and then incubated in the presence of suspensions of alpha-tocopherol for 30 min at 37 degrees C. Unabsorbed tocopherol was removed by centrifugation using several washes of isotonic phosphate-buffered saline. Washed erythrocytes were resuspended to 0.05%. Hct and exposed to hemolyzing doses of 60Co gamma radiation, and hemolysis was monitored continuously by light scattering at 700 nm in a recording spectrophotometer. The extent of hemolysis with time was sigmoid and data analysis was carried out on the time taken for 50% hemolysis to occur (t50%). The vitamin E content of erythrocytes was significantly elevated by the incubation procedure and resulted in the cells exhibiting a significantly increased resistance to hemolysis as reflected by the extended t50% values. Oral supplementation of 500 IU of vitamin E per day to eight normal human subjects for a period of 16 days also resulted in their washed erythrocytes exhibiting a significant increase in resistance to radiation-induced hemolysis. When comparing vitamin E incubated cells with control cells, both the dose-reducing factor (DRF) and the time for 50% hemolysis quotient (Qt50%) were observed to increase with increasing radiation dose.

Adolescents and abortion. A theoretical framework for decision making

A knowledge of the factors influencing adolescent decision making, combined with decision-counseling techniques, will allow the nurse to improve the quality of a young woman's decision process and to reduce adverse reactions afterwards. Indeed, the young woman may take from the experience a more positive appraisal of herself as a decision maker, and perhaps begin to know mature compassion for herself and others.

Cystatin, a protein inhibitor of cysteine proteinases. Improved purification from egg white, characterization, and detection in chicken serum

The protein from chicken egg white that inhibits cysteine proteinases, and has been named 'cystatin', was purified by ovomucin precipitation, affinity chromatography on carboxymethylpapain-Sepharose and chromatofocusing. The final purification step separated two major forms of the protein (pI 6.5 and 5.6), with a total recovery of about 20% from egg white. By use of affinity chromatography and immunodiffusion it was shown that the inhibitor is also present at low concentrations in the serum of male and female chickens. Tryptic peptide maps of the separated forms 1 and 2 of egg-white cystatin were closely similar, and each form had the N-terminal sequence Ser-Glx-Asx. The two forms showed complete immunological identity, and neither contained carbohydrate. Ki values for the inhibition of cysteine proteinases were as follows: papain (less than 1 X 10(-11)M), cathepsin B (8 X 10(-10)M), cathepsin H (about 2 X 10(-8)M) and cathepsin L (about 3 X 10(-12)M). Some other cysteine proteinases, and several non-cysteine proteinases, were found not to be significantly inhibited by cystatin. The inhibition of the exopeptidase dipeptidyl peptidase I by cystatin was confirmed and the Ki found to be 2 X 10(-10)M. Inhibitor complexes with active cysteine proteinases and the inactive derivatives formed by treatment with iodoacetate, E-64 [L-trans-epoxysuccinylleucylamido(4-guanidino)butane] and benzyloxycarbonylphenylalanylalanyldiazomethane were demonstrated by isoelectric focusing and cation-exchange chromatography. The complexes dissociated in sodium dodecyl sulphate/polyacrylamide-gel electrophoresis (with or without reduction) with no sign of fragmentation of the inhibitor. Cystatin was found not to contain a free thiol group, and there was no indication that disulphide exchange plays any part in the mechanism of inhibition.

Rehabilitation of post MI depression and psychological invalidism: a pilot study

The majority of survivors of myocardial infarction experience an array of psychological and emotional reactions. Often, persistent anxiety and depression impair recuperation and rehabilitation. A behaviorally based treatment approach is utilized which consists of a combination of deep muscle relaxation, imagery based desensitization, social reinforcement, stress management, activity scheduling and shaping technics. The spouse is utilized as a facilitator/co-therapist. This approach is shown to be effective in increasing adaptive function, decreasing depressive symptomology and facilitating return to acceptable premorbid levels of activity.

Recent trends in the Social Security Disability Insurance Program

Earlier analysis documented the rapid growth of the Disability Insurance (DI) program from 1966 to 1975; this article discusses trends since 1975. Over the decade of the 1970's, the population insured for disability increased by 34 percent, and women as a proportion of the insured population rose from 32.4 percent in 1970 to 39.1 percent in 1980, reflecting the increase in female labor-force participation. Of disabled workers receiving benefits, the proportion that were women rose from 28.4 percent in 1970 to 32.4 percent in 1979. Although inflation caused total benefit costs to rise over the entire period, the number of DI beneficiaries began to decline in 1978. Disabled-worker awards reached a peak in 1975 and fell subsequently so that the 1969 and 1981 figures are approximately equal. Relative to 1970, the fraction of awards going to women increased, the share for persons aged 50-54 rose, and the proportion received by those aged 60-64 declined. Decreased in total awards, and hence recipients, stemmed primarily from higher rates of denial at both the initial application and the reconsideration stages. Higher denials were countered by substantial rises in the number of hearings and reversals by administrative law judges (ALJ's). in 1980, only 65 percent of all awards came from initial applications, while over a fourth resulted from ALJ reversals. In future years, recent legislative changes may be expected to curtail program expansion further.

L-trans-Epoxysuccinyl-leucylamido(4-guanidino)butane (E-64) and its analogues as inhibitors of cysteine proteinases including cathepsins B, H and L

1. L-trans-Epoxysuccinyl-leucylamido(4-guanidino)butane (E-64) at a concentration of 0.5 mM had no effect on the serine proteinases plasma kallikrein and leucocyte elastase or the metalloproteinases thermolysin and clostridial collagenase. In contrast, 10 muM-E-64 rapidly inactivated the cysteine proteinases cathepsins B, H and L and papain (t0.5 = 0.1-17.3s). The streptococcal cysteine proteinase reacted much more slowly, and there was no irreversible inactivation of clostripain. The cysteine-dependent exopeptidase dipeptidyl peptidase I was very slowly inactivated by E-64. 2. the active-site-directed nature of the interaction of cathepsin B and papain with E-64 was established by protection of the enzyme in the presence of the reversible competitive inhibitor leupeptin and by the stereospecificity for inhibition by the L as opposed to the D compound. 3. It was shown that the rapid stoichiometric reaction of the cysteine proteinases related to papain can be used to determine the operational molarity of solutions of the enzymes and thus to calibrate rate assays. 4. The apparent second-order rate constants for the inactivation of human cathepsins B and H and rat cathepsin L by a series of structural analogues of E-64 are reported, and compared with those for some other active-site-directed inhibitors of cysteine proteinases. 5. L-trans-Epoxysuccinyl-leucylamido(3-methyl)butane (Ep-475) was found to inhibit cathepsins B and L more rapidly than E-64. 6. Fumaryl-leucylamido(3-methyl)butane (Dc-11) was 100-fold less reactive than the corresponding epoxide, but was nevertheless about as effective as iodoacetate.

Unusual distribution of Ia-like antigens on canine lymphocytes

The murine monoclonal antibody 7.2, specific for a framework determinant of human Ia antigens, cross-reacts with canine cell membranes recognizing a bimolecular complex (29,000 and 34,000 daltons) similar to that described in man. We investigated the distribution of these Ia-like antigens on mononuclear cells in peripheral blood, thoracic-duct lymph, marrow, alveolar lavage fluids, lymph nodes, and thymuses from normal dogs. By complement-mediated cytotoxicity and indirect immunofluorescence, virtually all lymphocytes expressing surface immunoglobulin (B lymphocytes), monocytes/macrophages, dendritic cells, and many thymus-epithelial cells were Ia-positive. Furthermore, most non-B-lymphocytes in peripheral blood, thoracic-duct lymph, and lymph nodes expressed Ia antigens. Alveolar (T) lymphocytes and most thymocytes were Ia-negative. Generally, fluorescence intensity was higher on monocytes/macrophages and B lymphocytes than on non-B-lymphocytes. In mixed leukocyte cultures and concanavalin A-induced blastogenesis assays, treatment of responder cells with antibody 7.2 and complement abolished proliferation. Proliferative responses could not be restored by adding untreated accessory cells, indicating that cytolytic treatment had eliminated responder T-lymphocytes. However, addition of antibody alone to cultures had no significant effect. These studies indicate that most mature canine T-lymphocytes express Ia-like antigens. Whether this is an intrinsic property of canine cells or possibly related to continuous in vivo stimulation remains to be determined.

Evaluation of penicillin in conjunction with acetohydroxamic acid in treatment of experimental Corynebacterium renale pyelonephritis

The therapeutic efficacies of procaine penicillin G and acetohydroxamic acid, when administered alone or in combination, were evaluated in rats with experimentally induced pyelonephritis at 24 h and 4 days after intrabladder inoculation with Corynebacterium renale. Penicillin alone prevented the development of pyelonephritis when administered in a once daily dose of 50,000 units for 5 days beginning within 24 h of infection challenge. However, if therapy was not initiated until the 4th day after induction of infection, pyelonephritis ensued which could not be differentiated from untreated rat pyelonephritis. Acetohydroxamic acid, when administered by itself in a once daily dose of 100 mg for 5 days, was completely ineffective whether therapy was started at 24 h or 4 days after initiation of infection. On the other hand, the combination of penicillin and acetohydroxamic acid prevented progression of pyelonephritic infection and facilitated healing when rat kidneys were examined at 14 and 30 days after initiation of infection. The kidneys of those rats sacrificed at 30 days after cessation of treatment revealed the presence of increased interstitial fibrous connective tissue in the renal medulla suggesting prior damage followed by recovery and repair. In vitro studies on the action of penicillin and acetohydroxamic acid against C. renale revealed no signs of synergism or antagonism.

Long term survival of enucleated segments of glial cytoplasm in the leech Macrobdella decora

Enucleated cytoplasmic segments of the giant connective glial cell (GCGC) survive morphologically intact for at least 10 weeks in the leech Macrobdella decora. Enucleated GCGC segments isolated from regenerating nerve axons show some degenerative changes after 4 weeks compared to GCGC segments which surround intact or regenerating nerve axons. Survival of GCGC cytoplasm is associated with an increase in the number of microglia. Relatively few (10-30%) nerve axons degenerate after severance from their cell body.

Identification of a human T lymphocyte surface protein associated with the E-rosette receptor

We describe a new monoclonal murine antibody that reacts with a 50,000-mol wt polypeptide that appears to be present on all E-rosetting cells. We conclude that this antigen is either identical to or closely associated with the E receptor because of (a) the high degree of concordance between E-rosette formation and 9.6 antigen expression, (b) the inhibition of rosette formation by preincubation of cells with 9.6 antibody, and (c) the observed failure of cells lysostripped of 9.6 antigen to form E-rosettes. This last finding suggests cocapping of 9.6 antigen and the E receptor.

A new human T-cell differentiation antigen: unexpected expression on chronic lymphocytic leukemia cells

Monoclonal antibody 10.2 reacts with a monomorphic antigen expressed on the surface of virtually all thymocytes, as well as thymus-dependent lymphocytes in the peripheral blood and bone marrow. In contrast, antibody 10.2 did not react with normal peripheral blood B cells, monocytes, or the non-T-cell fraction of bone marrow. This complement fixing IgG2a antibody also reacted with established leukemic T-cell lines, but not with cell lines of either normal or malignant B-cell origin. Similarly, when tested against acute leukemia blasts, the 10.2 antibody reacted with those from patients with T-cell acute leukemia, but not with those from patients with acute null cell or non-lymphocytic leukemia. An unexpected exception to this pattern was the reaction of 10.2 antibody with leukemic cells from patients with B-cell type chronic lymphocytic leukemia. Immune precipitates formed with 10.2 antibody and detergent lysates of radiolabeled T-cells contained three polypeptides with molecular weights of 65 000, 55 000, and 50 000 daltons. It has not been determined whether all three of these polypeptides contain the 10.2 antigenic determinant, or whether these proteins represent a multimeric antigen complex.

Generalized transduction in the enterobacterial phytopathogen Erwinia chrysanthemi

Bacteriophages induced by mitomycin treatment of Erwinia chrysanthemi KS612 produced plaques on lawns of E. chrysanthemi EC183 and KS605. Bacteriophage Erch-12, purified from one such plaque, transferred an array of chromosomal genes (arg, leu, his, ser, thr, trp, ura) to appropriate recipient strains derived from E. chrysanthemi EC 183. Recombinants were formed in the absence of cellular contact between donor and recipient bacteria and in the presence of deoxyribonuclease. Ultraviolet irradiation of the bacteriophage stimulated transductional frequency. Linkage was detected in two-factor crosses between the loci thr and ser and between rif and ade; several closely linked mutations in ser were mapped with respect to thr.

Essential hypertension: subjects' estimation of blood pressure as an aid to response generalization

9 persons (5 men and 4 women) with essential hypertension made 5 daily estimates of blood pressure over 8 wk. and after 12 wk. Estimations improved for systolic blood pressure. Reductions in levels occurred. No change appeared for controls.

Predicting warfarin maintenance dosage based on initial response

The relationship between initial response to warfarin sodium, as measured by prothrombin time, and warfarin maintenance dose was studied. Hospital patients received 10 mg of warfarin sodium daily until the prothrombin ratio (patient's prothrombin time/control) was 1.5 to 2.5. Patients subsequently were maintained at that warfarin dosage which maintained prothrombin ratios within this range. Twenty-two patients completed the study. A correlation was found between maintenance dose and the logarithm of the prothrombin ratio on the third day after initiating warfarin therapy (p less than 0.01, r = -0.74). There was no relationship between maintenance dose and the number of days needed to reach therapeutic response. Patients with baseline prothrombin ratios of less than one took significantly longer to reach therapeutic response than did patients with baselines of greater than one (p less than 0.01y. A simple yet scientific approach to determining warfarin maintenance dosage would seem to be feasible. The correlation found between maintenance dose and prothrombin ratio in this study would have to be applied cautiously and only after further validation.

Similarity of the structure of ferritin and iron . dextran (imferon) determined by extended X-ray absorption fine structure analysis

Ferritin, a natural complex of iron oxide encased in protein, and iron . dextran, a synthetic complex of iron oxide coated with dextran, have the similar properties of maintaining high concentrations of iron in solution at physiological pH and releasing iron relatively slowly in vivo. Extended x-ray absorption fine structure (EX-AFS) analysis was performed on each complex and compared to see if the structures of the iron cores were similar. The results obtained from the extended x-ray absorption fine structure technique show that the near-neighbor environment around the average iron atom in ferritin and iron . dextran is identical, within experimental uncertainty, for the first three shells. The similarity of the iron cores in both complexes may explain the similarity of iron release in vivo. Ferritin has a protein coat which is composed of 24 subunits arranged in a hollow sphere with six channels through which the iron may move during deposition and release. However, little is known about the requirements of the protein structure in ferritin for the maintenance of high concentrations of iron in a soluble, nontoxic form or about the role of the protein in the release of iron from ferritin. The results suggest that iron . dextran will be a useful model compound in studies of the relation of the iron core and protein in ferritin to function.

The electrophoretically 'slow' and 'fast' forms of the alpha 2-macroglobulin molecule

alpha 2-Macroglobulin (alpha 2M) was isolated from human plasma by a four-step procedure: poly(ethylene glyco) fractionation, gel chromatography, euglobulin precipitation and immunoadsorption. No contaminants were detected in the final preparations by electrophoresis or immunoprecipitation. The protein ran as a single slow band in gel electrophoresis, and was designated 'S-alpha 2M'. S-alpha 2M bound about 2 mol of trypsin/mol. Treatment of S-alpha 2M with a proteinase or ammonium salts produced a form of the molecule more mobile in electrophoresis, and lacking proteinase-binding activity (F-alpha 2M). The electrophoretic mobility of the F-alpha 2M resulting from reaction with NH4+ salts was identical with that of proteinase complexes. We attribute the change in electrophoretic mobility of the alpha 2M to a conformation change, but there was no evidence of a change in pI or Strokes radius. Electrophoresis of S-alpha 2M in the presence of sodium dodecylsulphate gave results consistent with the view that the alpha 2M molecule is a tetramer of identical subunits, assembled as a non-covalent pair of disulphide-linked dimers. Some of the subunits seemed to be 'nicked' into two-thires-length and one-third-length chains, however. This was not apparent with F-alpha 2M produced by ammonium salts. F-alpha 2M produced by trypsin showed two new bands attributable to cleavage of the subunit polypeptide chain near the middle. Immunoassays of F-alpha 2M gave 'rockets' 12-29% lower than those with S-alpha 2M. The nature of the interactions between subunits in S-alpha 2M and F-alpha 2M was investigated by treating each form with glutaraldehyde before electrophoresis in the presence of sodium dodecyl sulphate. A much greater degree of cross-linking was observed with the F-alpha 2M, indicating that the subunits interact most closely in this form of the molecule. Exposure of S-alpha 2M to 3 M-urea or pH3 resulted in dissociation to the disulphide-bonded half-molecules; these did not show the proteinase-binding activity characteristic of the intact alpha 2M. F-alpha 2M was less easily dissociated than was S-alpha 2M. S-alpha 2M was readily dissociated to the quarter-subunits by mild reduction, with the formation of 3-4 new thiol groups per subunit. Inact reactive alpha 2M could then be regenerated in high yield by reoxidation of the subunits. F-alpha 2M formed by reaction with a proteinase or ammonium salts was not dissociated under the same conditions, although the interchain disulphide bonds were reduced. If the thiol groups of the quarter-subunits of S-alpha 2M were blocked by carboxymethylation, oxidative reassociation did not occur. Nevertheless treatment of these subunits with methylammonium salts or a proteinase caused the reassembly of half-molecules and intact (F-) tetramers. It is emphasized that F-alpha 2M does not have the properties of a denatured form of the protein...

The suppressive effect of circulating specific antibody on the response to oral immunisation with Vibrio cholerae

Species IgG antibody given intravenously 3-4 hours prior to oral immunisation with Vibrio cholerae led to a specific depression of both the systemic and loca limmune response. One vibriocidal unit of IgG antibody, which itself would given undetectable levels of circulating specific antibody, was significantly immunosuppressive. The suppression is considered to be due to central repression of the antigen-reactive lymphocyte, rather than to antigen exclusion at the gut mucosal surface. The repression appeared less pronounced in some immunoglobulin classes than in others.

Photochemical dimerization of ferulic Acid by chloroplasts from sorghum

Sorghum (Sorghum bicolor) chloroplasts, lamellar fragments, and Triton X-100 solubilized preparations catalyze a blue and red light-sensitized oxidation of ferulic acid to its beta-beta-linked dimer and its hydrolysis product, the acid dimer. Exogenous superoxide dismutase had no effect, and catalase and 1 to 10 mm KCN inhibited this photooxidative dimerization only in detergent-treated chloroplasts. It is postulated that the final oxidant is H(2)O(2), formed by light-induced photosystem I electron transport, followed by an unidentified peroxidatic activity. The reaction differs, however, from that catalyzed by horseradish peroxidase in the presence of H(2)O(2).

A behavioral approach to post-catastrophic illness work phobias

Two patients developed work phobias following major catastrophic physical illness. A combined approach to addressing their specific fears of returning to premorbid levels of work function utilized deep muscle relaxation, imagery based desensitization, social reinforcement, and shaping techniques. A significant increase in adaptive function and decrease in depressive symptomatology resulted in both cases within six weeks after initiation of treatment.

Autoxidation in milk rich in linoleic acid. II. Modification of the initiation system and control of oxidation

Factors contributing to the initiation of lipid oxidation in cow's and mare's milk containing high levels of polyunsaturated fatty acids were studied. Addition of H2O2 just after milking, in slight excess of the stoichiometric amounts required to destroy ascorbic acid, delayed the development of oxidized flavours in cow's milk high in linoleic acid. Hydrogen peroxide treatment followed by the addition of alpha-or gamma-tocopherols prevented lipid oxidation in cow's milk even when 0.1 mg Cu/l milk was added. When used separately in the presence of Cu these treatments were ineffective as was butylated hydroxyanisole treatment. The lipid and ascorbic acid in mare's milk were remarkably stable to oxidation. Addition of 0.05 or 0.1 mg Cu/l, ethylenediamine tetraacetic acid, neocuproine, or H2O2 had very little effect on the loss of ascorbic acid and lipid oxidation in mare's milk.

Autoxidation in milk rich in linoleic acid. I. An objective method of measuring autoxidation and evaluating antioxidants

Autoxidation was studied in milk obtained from cows fed on formaldehyde-treated casein-safflower oil supplement. The fat of this milk contained high levels of linoleic acid. A rapid disappearance of dissolved oxygen (DO), measured by using a oxygen electrode, from milk samples stored at 0 degrees C in tubes without head-space, coincided with the development of oxidized flavours detected organoleptically. A correlation coefficient of 0.9 with 69 degrees of freedom (P smaller than 0.001) was obtained between the amount of DO disappearing and the taste panel scores for oxidized flavours. Butylated hydroxyanisole, sesamol, nordihydroguaiaretic acid, ethoxyquin, or butylated hydroxyanisole with propylgallate or tocopherols, when added in emulsified form to the milk at the rate of 10-15 mg/l milk checked the development of oxidized flavours and the rapid disappearance of DO. Other antioxidants tested were either ineffective or imparted off-flavours to milk. Samples of mare's milk neither developed oxidized flavours nor showed rapid disappearance of DO over a test period of 8 d. The oxygen electrode provides a convenient and sensitive method for studying autoxidation and evaluating antioxidants in milk.

Critical assessment of use of central venous oxygen saturation as a mirror of mixed venous oxygen in severely ill cardiac patients

Bedside catheterization of the right heart with a percutaneously introduced flowdirected catheter was carried out in 24 critically ill patients; 71 determinations of mixed venous oxygen saturation (MVo 2 ) were obtained. A second catheter was inserted either into a central intrathoracic vein or the right atrium for simultaneous sampling of central venous (CVo 2 ) or right atrial (RAo 2 ) oxygen saturation.

For the group as a whole, mean CVo 2 (57.9% ± 15.25) was significantly greater than mean MVo 2 (53.3% ± 14.84) ( P <0.001), but there was no significant difference and correlation was good between changes in central venous compared to changes in mixed venous oxygen saturation. On the other hand, there was no significant mean difference as well as an excellent correlation between individual values of RAo 2 and MVo 2 (r=+0.95).

Patients with heart failure or shock showed poor correlation between CVo 2 and simultaneously determined MVo 2 . Furthermore, subjects with shock showed a mean CVo 2 (58.0%±13.05) that was significantly greater than mean MVo 2 (47.5% ± 15.11). In contrast, there was no significant difference between mean RAo 2 and mean MVo 2 and excellent correlation of individual values in patients with either heart failure or shock. Although CVo 2 is a poor reflection of MVo 2 in subjects with severe heart failure or shock, there was a better correlation between changes in CVo 2 with corresponding changes in MVo 2 . In addition, RAo 2 correlated closely with corresponding values of MVo 2 . The reversal of the normal relationship between CVo 2 and MVo 2 under these circumstances is compatible with the thesis that low output states are attended by redistribution of blood flow away from femoral, splanchnic, and renal circulation with preferential preservation of cerebral blood flow.