Biomedical subjects

S P Halbert

Publications and source records attributed to S P Halbert.

18 recordsLinked to original sources

PubMed1986

Quantitative estimation by a standardized enzyme-linked immunosorbent assay of human T-cell lymphotropic virus type I antibodies in adult T-cell leukemia and acquired immune deficiency syndrome.

Sera from patients with adult T-cell leukemia and asymptomatic carriers of human T-cell lymphotropic virus type I (HTLV-I) from widely separated areas of the world reacted strongly in a standardized quantitative enzyme-linked immunosorbent assay procedure with HTLV-I viral antigen prepared from a strain isolated in the United States. There was a sharp differentiation of the values seen in the patients as compared with a normal population. Of the 35 acquired immune deficiency syndrome patients with Kaposi's sarcoma, only 2 were positive for HTLV-I antibodies in this test, and the distribution of the negative assay values in the other acquired immune deficiency syndrome patient sera was similar to that seen in the normal sera. Sera which contained extremely high levels of antibodies to other unrelated viruses (rubella virus, cytomegalovirus, and herpes simplex virus) all showed negative anti-HTLV-I results, in a pattern similar to the normal sera. Sera from patients with several autoimmune disease (systemic lupus erythematosus, rheumatoid arthritis, thyroiditis) as well as those with infectious mononucleosis or myeloma all also showed the normal distribution of negative results, in spite of the presence of very high levels of the autoantibodies, etc., associated with their illnesses.

Acquired Immunodeficiency Syndrome↗

PubMed1986

Antibody levels for cytomegalovirus, herpes simplex virus, and rubella in patients with acquired immune deficiency syndrome.

Significantly higher proportions of patients with acquired immune deficiency syndrome (AIDS) or lymphadenopathy syndrome (LAS) were positive for antibodies to cytomegalovirus (CMV) and herpes simplex virus (HSV) compared with control groups of commercial blood donors. In contrast, no differences were found in the incidence of individuals positive for antibodies to rubella in these groups of subjects. Of those positive for antibodies to CMV and HSV in each group, the mean antibody levels were significantly higher in AIDS-LAS patients compared with the controls. The entire distribution of antibody concentrations to CMV and HSV in AIDS patients was shifted upward, so that significantly more patients showed high values and significantly fewer showed low values, indicating hyperactive humoral immune responses to these viruses. In sharp contrast, the AIDS patients with antibody levels for rubella showed the same distribution of antibody levels as did two groups of controls. No correlation was found between concentrations of CMV and HSV antibodies in individual AIDS-LAS patients.

Acquired Immunodeficiency Syndrome↗

PubMed1986

Rapid dot enzyme immunoassay for the detection of antibodies to cytomegalovirus.

Cytomegalovirus (CMV) antigen was coated onto a white opaque plastic card as small dots inside circles marked in the microtiter plate well pattern. The card with antigen dots could be cut according to the number of test samples to be assayed. Small drops of undiluted serum samples, goat antibodies to human immunoglobulin G labeled with alkaline phosphatase, and finally substrate (5-bromo-4-chloro-3-indolyl phosphate) were sequentially added to the antigen spots and incubated in the open air at room temperature for 5 min each. The antigen dots showed blue color for sera with immunoglobulin G antibodies to cytomegalovirus but no color for those without. The developed antigen dots could be rinsed with water and kept as permanent records. For the assay of a large number of serum samples, a modified procedure with serum diluted 1:10 and longer first two incubations (20 min each) was found to be more comfortable to perform. The results of this assay for 123 undiluted and 256 diluted serum samples revealed very good correlations with those obtained by a commercially available test kit for immunoglobulin G antibodies to cytomegalovirus with 97 and 99% agreement, respectively. This dot test was very reproducible and required no instrumentation. The reagents, including coated antigen dots, are stable at room temperature for at least 2 months and are ready for use.

Adult↗

PubMed1978

Immunological relationships of human and subhuman primate pregnancy-associated plasma proteins.

(1) Four pregnancy-associated plasma proteins cross-reactive with antibodies to the human pregnancy proteins were detected in several species of pregnant subhuman primates. In the case of the two apes studied (chimpanzee and orangutan), these appeared to be immunologically identical to the human PAPPs (PAPP-A, -B, -C, and HCS). In the old world monkeys analyzed, equivalent partially cross-reactive PAPPs were found; while in the new world squirrel monkey, only faint traces of cross-reactive PAPP-C and HCS were observed with the most sensitive methods used. (2) As in the human, these proteins appeared to be specific for pregnancy, not being detectable in nonpregnant animals, female or male. (3) The pregnant chimpanzee possessed significantly higher concentrations of PAPP-A and PAPP-C than did women at an equivalent stage of pregnancy, while the HCS and PAPP-B levels appeared to be approximately the same. (4) The primate PAPP-C analogues were more complex than human PAPP-C, often revealing multiple gel diffusion patterns with subfractions of differing electrophoretic mobilities. (5) Based on the changes of electrophoretic mobility upon exposure to neuraminidase, the subhuman primate as well as human PAPP-A and PAPP-C appeared to be glycoproteins containing sialic acid. (6) In the chimpanzee and rhesus monkey, as in the human, the levels of PAPP-A, PAPP-C, and HCS were appreciably higher during the third trimester of pregnancy than they were during the second trimester.

Animals↗

PubMed1978

Pregnancy-associated plasma proteins in pregnant and pseudopregnant rats.

As in the human, the rat pregnancy-associated plasma proteins consisted of four distinct entities as revealed by immunological methods. All showed gradual increases during gestation and rapid disappearance postpartum. They could be physicochemically, although not immunologically, tentatively related to the human pregnancy proteins. None of them was detectable in the serum of rats at various stages of pseudopregnancy, nor in nonpregnant rats.

Animals↗

PubMed1978

Characterization and purification of pregnancy-associated plasma protein B (PAPP-B).

PAPP-B is a pregnancy-specific beta 1-glycoprotein of large molecular weight, about 1,000,000 as determined by Sepharose 4B and 6B gel filtration. Its isoelectric point is between pH 4.6 and 5.0. It has been purified at least 800-fold from term pregnancy serum by a sequence of steps involving salting out at 30% saturation with ammonium sulfate (1,2M), DEAE-cellulose chromatography, Sepharose 4B gel filtration and hydroxylapatite chromatography. Monospecific antiserum to PAPP-B has been prepared, and used to differentiate it from several other newly reported tumor or pregnancy proteins. PAPP-B was found to increase slowly during the second trimester of pregnancy and more steeply during the third, reaching a plateau in late gestation. During the postpartum period, PAPP-B disappeared quite rapidly, with an apparent half-life of less than 1 day.

Blood Proteins↗

PubMed1977

Plasma concentrations of four pregnancy proteins in complications of pregnancy.

Toxemia of pregnancy was associated with an elevation of the pregnancy-associated plasma protein (PAPP)-A concentration, as compared to the level in normal pregnancy in the last month of gestation. The other pregnancy proteins measured were not altered in toxemia. In twin pregnancies, the PAPP-A, PAPP-C, and human placental lactogen levels were all increased, particularly PAPP-A. On the other hand, pregnancy zone protein was not affected by twinning. Pregnancy with diabetes showed normal levels of these proteins.

Blood Proteins↗

PubMed1977

Detection of hepatitis B surface antigen (HBS Ag) with use of alkaline phosphatase-labeled antibody to HBS Ag.

An enzyme-labeled "sandwich" assay was developed for the detection of the hepatitis B surface antigen (HBS Ag) with use of calf intestinal alkaline phosphatase and horse antibody to HBS Ag. It involved a total incubation time of 2.5 hr in three steps and was approximately equivalent in sensitivity to one of the commercially available radioimunoassays. The confirmatory test was of the neutralization type and required an additional 30-min incubation step. The enzyme-labeled antibody solution and the solid-phase antibody were extremely stable. They withstood storage at 2 C-8 C for longer than one year with virtually no decrease in activity. Accelerated tests of stability in storage at room temperature (20 C-24 C) showed only a small loss of potency over a one-year period. Three specimens were encountered that were confirmably positive by enzyme-labeled immunoassay but negative by radioimmunoassay.

Alkaline Phosphatase↗

PubMed1977

Immunologic reactivity of purified human urinary kallikrein (urokallikrein) with antiserum directed against human pancreas.

Donkey antiserum to normal human pancreas absorbed with lyophilized human plasma recognized human urokallikrein in concentrated crude urine or after an approximately 500-fold purification. The urokallikrein antigen was associated with kinin-generating and alpha-N-p-tosyl-L-arginine methyl ester (TAMe) cleaving activity on isoelectric focusing, with the isoelectric point being 3.8 to 4.4. Both kiningenerating and esterolytic activity were removed from the purified urokallikrein by an immunoadsorbent prepared by coupling the IgG fraction of the absorbed donkey antiserum to Sepharose 6B. The failure of anti-plasma kallikrein to react in immunodiffusion with purified urokallikrein indicates that urinary kallikrein is distinct from plasma kallikrein although antigenically related to glandular kallikreins.

Animals↗

PubMed1976

Placental localization of human pregnancy--associated plasma proteins.

Frozen sections of human placenta were examined for the presence of four human pregnancy proteins, pregnancy-associated plasma proteins A and C (PAPP-A and PAPP-C), human chorionic somatomammotropin (hCS), and pregnancy zone protein (PZP), by the indirect immunofluorescence technique. Monospecific rabbit antiserums to PAPP-A, PAPP-C and hCS all stained the trophoblast cytoplasm equivalently in a continuous layer, usggesting that the same trophoblast cells synthesize all three pregnancy proteins. In contrast, PZP was localized in blood vessel walls, parenchymal structures within the villous, as well as in the trophoblast cytoplasm. Its distribution in the latter was relatively inhomogeneous, tending to be more intense on the basement membrane side.

Blood Proteins↗

PubMed1976

Relation of obstetric parameters to the concentrations of four pregnancy-associated plasma proteins at term in normal gestation.

The relations between normal obstetric parameters and the maternal levels of four pregnancy-associated plasma proteins (PAPP) were studied, with the use of plasma samples taken from 187 normal pregnant women within seven days before delivery. PAPP-A levels were correlated with placental and newborn weights. The levels of this pregnancy protein was higher in primigravid women and in groups with higher diastolic blood pressure than in other groups. Women with extremely high PAPP-A concentrations were likely to have extremely large placental weight was not necessarily associated with a high PAPP-A level. PAPP-C was not correlated with placental or newborn weight. The relationship between PAPP-C and maternal age, as well as maternal weight, was significant by one but not in the other three statistical analyses employed. The pregnancy zone protein was found to be correlated with parity. In primigravid women, this protein additionally showed an inverse correlation with the placental weight. Human chorionic somatomammotropin was significantly related to placental weight and inversely related to maternal weight. Its relationship with newborn weight was best seen in primigravid subjects. Other parameters (systolic blood pressure, one- and five-minute Apgar scores, weeks of gestation, days before delivery, newborn sex, and newborn bilirubin level) were not related to any of these pregnancy proteins.

Adolescent↗

PubMed1976

Human pregnancy-associated plasma proteins during the postpartum period.

The plasma levels of four pregnancy-associated plasma proteins (PAPP's) and pregnancy zone protein (PZP) were studied in women after delivery of a single viable infant by gel immunodiffussion methods. Data from 89 random samples and 85 serial specimens from five women revealed that both PAPP-B and HPL (PAPP-D) disappeared within a day after delivery. PAPP-A showed a rapid drop in the first 2 or 3 days post partum and became nondetectable in 4 to 6 weeks, with a half-life of 3 to 4 days. PAPP-C had a sharp decrease by the second postpartum day and was not detected 3 to 4 weeks later, with a half-life of 1 to 2 days. None of the PAPP's was detected again during the rest of the 14 postpartum weeks studied. In contrast, the PZP showed a much slower decrease or even a temporary increase during the first 2 weeks post partum; it remained readily detectable over the entire 14 weeks studied.

Blood Proteins↗

PubMed1976

Purification of group C streptococcal extracellular antigens detected with naturally occurring human antibodies: isolation of streptokinase and two previously undescribed antigens.

Twelve antigens were detected in crude group C streptococcal extracellular concentrates, using naturally occurring antibodies in normal human gamma globulin. These group C streptococcal antigens all appeared to be present in crude group A streptococcal extracellular concentrates, although the latter contained additional antigens reactive with the human antibodies. Systematic purification procedures were established for the isolation of the group C streptococcal antigens by a sequence of salting out, hydroxylapatite chromatography, Sephadex G-100 gel filtration, and isoelectric focusing. With such procedures, three of the group C streptococcal antigens were isolated in a relatively pure state. One of the purified antigens was identified as streptokinase on the basis of its fibrinolytic potency, its reaction of identity with two purified streptokinase fractions obtained from other sources, and its high titer in immunodiffusion assays. The most highly purified streptokinase fractions, derived from the 0.1 M sodium phosphate hydroxylapatite eluate, revealed a plasmin-inhibiting effect at high concentrations of streptokinase. This was not seen in the purified streptokinase of equivalent functional and immunological purity that was derived from the 0.2 M sodium phosphate hydroxylapatite peak. Two other streptococcal antigens were also isolated to a high degree during the course of the above study. These were designated antigens X and Y and were found to be unrelated immunologically to each other or to streptokinase. Their isoelectric points were 6.7 and 8.8, respectively, and both were present in group A streptococcal concentrates. Esterase activity was found to be widely distributed in almost all of the fractions obtained in the various purification steps, indicating a high degree of heterogeneity of the streptococcal enzyme. Histochemical staining techniques applied to the immune precipitates formed with human antibodies indicated that none of the antigens detected in crude group C and group A streptococcal concentrates possessed catalase, glucuronidase, glucosaminidase, acid or alkaline phosphatase, arylsulfatase, leucineaminopeptidase, or chymotrypsin enzymatic activities.

Antigen-Antibody Reactions↗

PubMed1976

Two previously undescribed extracellular streptococcal antigens detectable with naturally occurring human antibodies.

Two streptococcal extracellular antigens (X and Y), which are detectable with naturally occurring human antibodies, have been isolated and shown to represent entities distinct from previously described streptococcal enzymes, toxins, and antigens. They are each synthesized by both group C and group A streptococci and appear to be proteins. Both antigens were found to be nonhemolytic and nontoxic for human leucocytes as well as for isolated beating newborn rat heart cells in tissue culture. In addition to being distinct from known streptococcal enzymes, they were also shown to be devoid of several other enzymatic activities.

Animals↗

PubMed1976

Quantitative analysis of pregnancy-associated plasma proteins in human placenta.

By immunochemical methods and simultaneous measurements of several normal plasma proteins, human placenta was shown to contain elevated quantities of four pregnancy-associated plasma proteins (PAPP's). In the order of increasing amounts, PAPP-A, PAPP-C, PAPP-B, and human chorionic somatomammotropin (PAPP-D) all were present in placenta extracts in quantities greater than could be expected on the basis of their content in maternal blood. In sharp contrast, the placental content of pregnancy zone protein could be entirely accounted for by the maternal plasma present in the placenta. All of the PAPP's appeared to be readily extractible from placental tissue with buffered saline, the large bulk of them being solubilized in the first extraction procedure. However, absorption studies indicated that appreciable quantities of the PAPP's were still present in the insoluble placental residue after 12 sequential extractions with saline. The chorioamniotic membranes were not significantly enriched in any of the PAPP's. Immunochemical analysis of unwashed placental tissue extracts for the PAPP's IgA, and IgM (maternal blood derived), as well as albumin and transferrin (maternal and fetal blood derived), permitted calculations to be made of the amount of blood and PAPP's in placenta. On the basis of these data, it was roughly estimated that a 400-g placenta (wet weight) would occupy 312 ml in volume, and would contain 144 ml of blood. Of this blood, 36 ml would be derived from the mother.

Antibodies↗

PubMed1976

Pregnancy zone protein analogue in pregnant and non-pregnant primates, and its decrease during pregnancy in some monkey species.

Rabbit antiserum to human pregnancy zone protein (PZP) cross-reacted with analogous proteins in several species of primates. The chimpanzee PZP showed reactions of identity with human PZP, while the PZP analogue in the orangutan, in four species of old world monkeys (pig-tailed, rhesus, cynomolgus and stump-tailed) and in a species of new world monkey (squirrel) showed equivalent reactions of partial identity with human PZP. In the chimpanzee and orangutan, the PZP analogue was present in low concentrations in non-pregnant animals, but as in the human, it increased quite appreciably during gestation. In the chimpanzee, this increase in pregnancy was about four-fold greater than in the human. In sharp contrast, in the old and new world monkeys, the PZP analogue was present in much higher concentrations in non-pregnant animals than it is in humans. In addition, during pregnancy the PZP analogue in these monkey species actually decreased during pregnancy. In the few cases studied, normal levels were regained about 1 month after delivery. A normal plasma protein, alpha2-macroglobin, was also studied in these primate species, because this protein shares some characteristics with PZP. Analogous alpha2-macroglobulin serum proteins were found in all the primates tested, but the observed gel diffusion identity patterns suggested that this protein was phylogenetically older than PZP. alpha2-macroglobulin increased slightly during human pregnancy, but in all the other primates studied, the alpha-macroglobulin analogue was either unchanged or slightly decreased during gestation.

Animals↗

PubMed1975

Immunological comparison of various human pregnancy-associated plasma proteins.

Direct immunodiffusion comparison with specific antisera demonstrated that all of the four pregnancy-associated plasma proteins (PAPPs) described in our laboratory are distinct from the pregnancy zone protein (von Schoultz); alpha2-pregnoglobulin (Berne); pregnancy-associated alpha2-glycoprotein (SP3) (Bohn); new serum alpha2-macroglobulin (Stimson); PAG (Horne); pregnancy-associated alpha2-globulin (Kasukawa); Pal (McLaren), and Xh protein (Dunston). All the latter proved to be immunologically idnetical to each other, and apparently represent the same protein described under different names. It was confirmed that none of the PAPPs is immunochemically related to placental alkaline phosphatase. PAPP-A, PAPP-C, and the pregnancy zone protein, but not HPL (PAPP-D), showed a decreased anodic mobility when treated with neuraminidase; their reactivities with antibody were essentially unaffected by the ezyme, however. Certain detergents had no effect on the immunological reactivities of the PAPPs and the pregnancy zone protein in whole plasma, while butanol and desoxycholate partially, and urea, SDS and cetylpyridinium largely inactivated them.

Alkaline Phosphatase↗

PubMed1975

Two pancreas "tissue-specific" antigens in normal human urine, one being and esterase.

Hyperimmune antiserum to human pancreas was exhaustively absorbed with plasma, kidney, and submaxillary gland. The resulting antiserum showed up to seven antigens in pancreas extracts by gel diffusion methods, but failed to react detectably with extracts of 17 other organs and tissues. However, this apparently "tissue-specific" anti-pancreas reagent regularly revealed two of the pancreas antigens in normal human urine concentrates. One of the latter was an anodal esterase. Although the identity of the second is not yet known, it was shown to be devoid of the following enzyme activities: amylase, catalase, glucosaminidase, glucuronidase, cystine-aminopeptidase, phosphatases and sulfatase.

Absorption↗