Biomedical subjects
D C Anderson
Publications and source records attributed to D C Anderson.
The importance of the Mac-1, LFA-1 glycoprotein family in monocyte and granulocyte adherence, chemotaxis, and migration into inflammatory sites: insights from an experiment of nature.
The Mac-1, LFA-1 (lymphocyte function-associated 1), p150,95 family of glycoproteins, which share a common beta subunit of Mr 95 000, are of widespread importance in leucocyte adhesion reactions. This paper focuses on the role of this glycoprotein family in granulocyte and monocyte adhesion and chemotaxis in vitro, and in migration into inflammatory sites in vivo. Most findings have been made with granulocytes, but results with monocytes are similar. Some studies have used leucocytes from patients exhibiting a severe or moderate deficiency in expression of this glycoprotein family, which is secondary to a defect in the common beta subunit. Patients are susceptible to bacterial infections and have defective pus formation and Rebuck skin-window tests, despite chronic granulocytosis. Granulocytes from such patients exhibit defective adherence to serum albumin and fibronectin-coated glass or plastic, defective orientation and directed migration in response to chemoattractants, and are defective in chemoattractant-stimulated aggregation and hyperadherence. Antibodies to the common beta subunit, to the Mac-1 alpha subunit, and to a lesser extent to the LFA-1 and p150,95 alpha subunits, inhibit many of the same functional responses by normal cells. In normal granulocytes and monocytes chemoattractants stimulate a five-fold increase in Mac-1 and p150,95 surface expression, by mobilization of a latent, presumably intracellular, pool. Cells from patients are deficient in up-regulation of these molecules but show normal up-regulation of other surface receptors, degranulation and oxidative burst. The hypothesis is presented that Mac-1 and p150,95 regulate or directly mediate the increase in granulocyte and monocyte adhesivity, which is essential for diapedesis, chemotaxis and migration into inflammatory sites.
Binding of the adhesive protein complex (LFA-1/Mac-1/p150,95) to concanavalin A.
At least 30 proteins from human PMNL plasma membranes capable of binding concanavalin A (Con A), can be identified after surface labeling with 125I and subsequent sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Immunoprecipitation of the labeled proteins after solubilization in non-ionic detergents, with monoclonal antibodies (MAbs) directed against a family of leukocyte membrane proteins (LFA-1, Mac-1, p150,95, and the beta subunit these glycoproteins share), indicated that Mac-1 and p150,95 were bound by Con A. Dissociation of the alpha and beta subunits with sodium dodecyl sulfate, electrophoresis, transfer to nitrocellulose paper, and subsequent binding of these proteins by Con A demonstrated Con A retention by Mac-1-alpha, p150,95-alpha, and the common beta subunit. Affinity of Con A for LFA-1-alpha from human peripheral blood PMNL could not be confirmed by direct binding or electroblotting. Similar experiments in a patient deficient in LFA-1, Mac-1, p150,95, and the beta subunit confirmed that Mac-1-alpha and the beta subunit were important Con A-binding proteins.
Two-dimensional and three-dimensional movement of human polymorphonuclear leukocytes: two fundamentally different mechanisms of locomotion [corrected].
Patients with an inherited deficiency of the adherence glycoproteins LFA-1, Mac-1, and p150,95 are unable to mobilize polymorphonuclear leukocytes (PMNLs) to peripheral sites of inflammation. LFA-1/Mac-1/p150,95-deficient PMNL exhibited profoundly impaired movement stimulated by chemotactic factors when the cells were required to move over two-dimensional surfaces. Less impairment of movement was demonstrated in three-dimensional movement through cellulose filters. A possible explanation for this difference in cell translational mobility is that movement in cellulose filters is less adherence dependent than movement over a two-dimensional plastic surface. Movement of PMNL in collagen gels is known to be relatively independent of adherence. No deficiency of translational mobility of PMNL from LFA-1/Mac-1/p150,95-deficient patients was observed in collagen gels. Antibodies against the common beta subunit effectively blocked two-dimensional movement but had little effect on three-dimensional movement through cellulose filters or collagen gel matrices. HL-60 cells were employed as a model to investigate the effects of adherence on cell movement. Treatment of HL-60 cells with phorbol myristate acetate resulted in the appearance of Mac-1 and p150,95 on the cell surface. Concurrently, the cells exhibited increased adherence to glass and plastic. In spite of increased adherence, HL-60 cells showed no translational movement, indicating factors other than the ability to adhere were important in cell motility. These experiments implied that PMNLs undergo two fundamentally different kinds of motion, one adherence dependent (two-dimensional movement) and the other largely adherence independent (three-dimensional movement). These findings are consistent with the view that egress of PMNLs from the vascular space is adherence dependent. Movement through extravascular tissues may be adherence independent.
Posttransfusion cytomegalovirus infection in neonates: role of saline-washed red blood cells.
Explore the source record for details and available documents.
Isolation of a T-lymphotropic retrovirus from naturally infected sooty mangabey monkeys (Cercocebus atys).
Healthy mangabey monkeys in a colony at the Yerkes Regional Primate Research Center were found to be infected with a retrovirus related to human immunodeficiency virus (HIV). Virus was isolated from peripheral blood cells of 14 of 15 randomly selected mangabeys. All virus-positive animals had antibodies to the mangabey virus at the time of virus isolation and, in a retrospective study, 82% of mangabey serum samples obtained in 1981 had antibodies to the virus. The newly isolated retrovirus is (i) morphologically identical to HIV by electron microscopy; (ii) serologically related to the human virus by enzyme immunoassay, immunoblotting experiments, radioimmunoprecipitation, and neutralization; and (iii) cytopathic for human OKT4+ cells. The mangabey virus also shares these properties with the simian T-lymphotropic virus type III (STLV-III) recently isolated from diseased macaques and from healthy African green monkeys (STLV-IIIAGM). However, the mangabey virus, like STLV-IIIAGM, differs from both HIV and STLV-III in that it apparently does not cause clinical immunodeficiency or disease following natural infection of the host from which it was isolated. Comparison of the virus-host interactions of these isolates may be valuable in defining determinants of pathogenicity for cytopathic retroviruses.
Primary structure and cDNA cloning of human fibroblast collagenase inhibitor.
We report the primary structure and cDNA cloning of human fibroblast collagenase inhibitor, a glycoprotein that appears to play a central role in modulating the activity of a number of metalloendoproteases of connective tissue origin including collagenase, gelatinase, and proteoglycanase. Secreted human fibroblast collagenase inhibitor was purified and subjected to automated Edman degradation. The secreted protein consists of 184 amino acid residues; it contains two sites of N-linked oligosaccharide linkage and six disulfide bonds. Synthetic oligonucleotide probes based on selected amino acid sequences of the inhibitor were used to screen a lambda gt10 cDNA library from a human fibroblast line. Two overlapping cDNA clones were characterized to determine the complete coding and noncoding sequences of the specific mRNA. The amino acid sequence deduced from the nucleotide sequence agrees with that determined by protein sequencing. One clone appears to contain the complete 5' end and, in addition, the cDNA sequence predicts a 23-amino acid leader peptide. The other clone represents the 3' end of the mature message and includes a short poly(A)+ tract. This 3' sequence is remarkably similar to a reported cDNA encoding part of the protein derived from mouse fibroblast poly(A)+ RNA. However, this inhibitor has no substantial homology with previously sequenced protease inhibitors.
Primary amebic meningoencephalitis.
Explore the source record for details and available documents.
Comparison of blood spot, salivary and serum progesterone assays in the normal menstrual cycle.
Sensitive direct (non-extraction) radioimmunoassays for assay of progesterone (Po) in saliva and capillary blood dried on filter paper have been developed to facilitate collection of specimens for the assessment of luteal function in the investigation of infertility. The antiserum had been raised to a Po 11 alpha-hemisuccinyl conjugate and the assays employ Po 11 alpha-glucuronyl-[125I]tyramine as tracer with separation by solid phase double antibody. Po levels in saliva and capillary blood were compared with those in serum in matched specimens collected daily throughout the menstrual cycle from six female volunteers. The correlation between blood (y) and serum (x) Po levels (y = 0.439x - 2.98, r = 0.98) was superior to that between salivary (y) and serum levels (x) (y = 0.00637x + 0.020, r = 0.89). Blood spot and serum Po levels were uniformly undetectable throughout the follicular phase, whereas in 2 out of 72 saliva specimens Po was inappropriately raised (60 and 120 pmol/l) possibly reflecting contamination of the specimens. Salivary and blood progesterone assays both lack adequate sensitivity to measure Po reliably in early or late luteal phases when serum levels are less than 12 nmol/l but are well suited to assess luteal function during the mid-luteal phase of the cycle (4-10 d before menses) when serum levels in the six subjects ranged from 22-84 nmol/l, with corresponding blood levels of 6.2-3.5 nmol/l and saliva levels of 130-620 pmol/l. We conclude that blood spot and saliva Po levels both correlate well with Po levels in serum, but that blood spot Po levels are more reliable.
Does testosterone affect the normal menstrual cycle?
In order to throw further light on the role of androgens in the aetiology of the polycystic ovary syndrome (PCO) we have examined the effect of artificially increasing serum testosterone levels on menstrual function in a group of ovulating women. Six women were studied who had either severe premenstrual syndrome or loss of libido for which they were treated with 100 mg testosterone by s.c. implantation. All had regular menstrual cycles. For 1 month before implantation serum LH, FSH, oestradiol (E2), progesterone and testosterone were measured three times per week. All women showed normal cyclical variation of LH, FSH, E2 and progesterone. Following implantation, three times weekly blood samples were taken during the first and third cycles. No patient had any disturbance of menstrual pattern. All continued to show cyclical changes of LH, FSH, E2 and progesterone. Serum E2 and progesterone were lower but not significantly so in the luteal phase of the treated cycles. This was despite a mean serum testosterone which rose from 1.3 to 7.1 nmol/l at the end of the third week following implantation and to 4.1 nmol/l at the end of the third month. Sex hormone binding globulin levels fell as expected by 18.5% during the first cycle. The lack of significant effect of a markedly elevated serum testosterone level on cyclical hormone changes is indirect evidence that in PCO the primary cause of the menstrual disturbance is not excessive production of ovarian or adrenal testosterone.
Effects of medroxyprogesterone acetate in women with polycystic ovary syndrome.
LH levels are inappropriately elevated in women with polycystic ovary syndrome (PCO). Regardless of whether this LH elevation is primary or secondary it may be involved in the establishment of chronic anovulation. We have therefore tried selectively to suppress LH by giving medroxyprogesterone acetate (MPA) 5 mg twice daily for 14 d to 13 women with PCO (14 studies) and have examined their pituitary and ovarian response to assess whether follicular development and ovulation would be triggered post-treatment as a result of secretion of endogenous gonadotrophins in a more nearly physiological ratio. Blood samples were obtained before and two to three times weekly during and after treatment for 35-50 d. In two of these cycles MPA was started fortuitously during the luteal phase of a spontaneous cycle. In the remainder, three patterns of response were seen. In 9 cycles, after an initial rise, there was a progressive fall in gonadotrophin levels, LH (mean 48% of basal) more than FSH (mean 68% of basal); after MPA was stopped FSH levels recovered more rapidly than LH. In two cycles (one subject) MPA administration was associated with a progressive rise in serum oestradiol and progesterone. In a further cycle, treatment was also accompanied by an oestradiol rise and was followed by establishment of regular ovulatory cycles. The observed differential suppressive effect on LH and FSH levels suggests that MPA might be of therapeutic value if followed by treatment with anti-oestrogens or exogenous gonadotrophins in PCO.
Ovulation after treatment with ethinyl-oestradiol and medroxyprogesterone acetate in a woman approaching premature menopause. Case report.
Explore the source record for details and available documents.
Stoichiometries of acetylcholine uptake, release, and drug inhibition in Torpedo synaptic vesicles: heterogeneity in acetylcholine transport and storage.
Highly purified Torpedo electric organ synaptic vesicles form a 49 nM suspension at 1 mg protein/ml. Under active transport conditions hundreds of molecules of [3H]acetylcholine ([3H]ACh) can be accumulated per vesicle, which requires the ACh transporter to undergo multiple turnovers. The transport blocker trans-2-(4-phenylpiperidino)cyclohexanol (AH5183) has no effect on storage of endogenous ACh by vesicles. In contrast, AH5183, other blocking drugs, and nonradioactive ACh caused a rapid release of at least 30-63 molecules of newly transported [3H]ACh per vesicle. Thus AH5183 distinguishes recently transported "new" vesicular ACh from "old" endogenous ACh. l-AH5183 inhibits transport of ACh with a half-inhibitory concentration of 16 +/- 7 nM at 12 nM vesicles and 115 +/- 34 nM at 120 nM vesicles. With the assumption that AH5183 acts on a receptor in an unamplified manner about 2.7 or fewer receptors per vesicle need to be occupied to cause inhibition of ACh transport. The apparent amplification in the number of [3H]ACh molecules per vesicle that are released by AH5183 suggests that AH5183 inhibits ACh storage by an indirect mechanism that distinguishes new from old ACh.
Uncoupling of cholinergic synaptic vesicles by the presynaptic toxin beta-bungarotoxin.
The effect of the presynaptic neurotoxin beta-bungarotoxin (beta-BuTx) on the acetylcholine (ACh) storage system of synaptic vesicles isolated from the electric organ of Torpedo californica was studied. The toxin can totally inhibit active transport of [3H]ACh by the vesicles in a Ca2+-, time-, and concentration-dependent manner. Correlated with these effects is a 50-60% stimulation of the vesicle proton-pumping ATPase activity. The beta-BuTx-mediated transport inhibition and ATPase stimulation are antagonized by delipidated bovine serum albumin, not reversed by excess EGTA, and not mimicked by other cationic proteins or soybean or pancreatic trypsin inhibitors. The behavior is consistent with phospholipase A2 (PLA2)-dependent damage to the vesicle membrane caused by beta-BuTx, which results in uncoupling of the ATPase and ACh transporter systems. The nonneurotoxic Naja naja venom PLA2 causes similar effects, except that it is slightly more potent on a molar basis. About 100-fold more beta-BuTx is required to effect lysis of synaptic vesicles than to uncouple them. ATP is a strong inhibitor of beta-BuTx- but not of N. naja PLA2-mediated uncoupling. The observations suggest that a component of beta-BuTx toxicity in the cholinergic terminal might involve attack on synaptic vesicles or vesicle-like structures and that a nucleotide-like factor might modulate the toxicity.
Persistent infection of chimpanzees with human T-lymphotropic virus type III/lymphadenopathy-associated virus: a potential model for acquired immunodeficiency syndrome.
The lymphadenopathy-associated virus (LAV) prototype strain of human T-lymphotropic virus type III/LAV was transmitted to juvenile chimpanzees with no prior immunostimulation by (i) intravenous injection of autologous cells infected in vitro, (ii) intravenous injection of cell-free virus, and (iii) transfusion from a previously infected chimpanzee. All five animals that received more than one 50% tissue culture infective dose were persistently infected with LAV or chimpanzee-passaged LAV for up to 18 months. During this time they developed no illnesses, but they exhibited various degrees of inguinal and axillary lymphadenopathy and significant reductions in rates of weight gain. Detailed blood chemistry and hematologic evaluations revealed no consistent abnormalities, with the exception of immunoglobulin G (IgG) hypergammaglobulinemia, which became apparent in one animal 6 months postinfection and continued at more than 1 year postinfection. Transient depressions followed by increases in the numbers of T4 cells to levels greater than normal were observed in all animals after virus inoculation. However, the number of LAV-infected peripheral blood cells decreased with time after infection. Results of enzyme immunoassays showed that all infected animals seroconverted to IgG anti-LAV within 1 month postinfection and that antibody titers remained high throughout the period of observation. In contrast, only three of the five LAV-infected chimpanzees had detectable IgM antibody responses, and these preceded IgG-specific serum antibodies by 1 to 2 weeks. Virus morphologically and serologically identical to LAV was isolated from peripheral blood mononuclear cells of all infected animals at all times tested and from bone marrow cells taken from one animal 8 months after infection. One chimpanzee that was exposed to LAV only by sharing a cage with an infected chimpanzee developed lymphadenopathy and an IgM response to LAV, both of which were transient; however, no persistent IgG antibody response to LAV developed, and no virus was recovered from peripheral blood cells during a year of follow-up. Thus, LAV readily infected chimpanzees following intravenous inoculation and persisted for extended periods despite the presence of high titers of antiviral antibodies. However, the virus was not easily transmitted from infected to uninfected chimpanzees during daily cage contact.
Low dose intravenous 3-amino-1-hydroxypropylidene-1,1-bisphosphonate (APD) for the treatment of Paget's disease of bone.
Twenty patients with severe symptomatic Paget's disease were treated with a series of 15 mg intravenous infusions of 3-amino-1-hydroxypropylidene-1,1-bisphosphonate (APD). A regimen of either five consecutive days of treatment (regimen 1) or a course of 12 weekly infusions was administered (regimen 2). In five cases regimen 2 followed regimen 1 after a three month interval. Alkaline phosphatase levels fell in all patients and returned to the normal range in 12. All but one of the patients obtained symptomatic improvement. There was a median fall in alkaline phosphatase activity of 63%. Eight patients observed a transient increase in bone pain starting about 24 hours after the first infusion. Intravenous APD was well tolerated, and we conclude that it is an effective treatment for Paget's disease; this route of administration avoids the problem of poor and unpredictable gastrointestinal absorption seen when a bisphosphonate is given orally. The optimal dose and duration of APD therapy, frequency of relapse, requirement for further courses, and merits relative to other second generation bisphosphonates remain to be established.
Abnormal cytolytic activity of lymphocyte function-associated antigen-1-deficient human cytolytic T lymphocyte clones.
The involvement of the lymphocyte function-associated antigen-1 (LFA-1) membrane molecule in cytolytic T lymphocyte (CTL) interactions with lymphoid target cells was investigated using CTL clones derived from two patients with a heritable deficiency of LFA-1. LFA-1 surface expression on the CTL clones was 1% of the normal level of LFA-1, unchanged with prolonged culture, and identical on 14 different CTL clones. The function of the LFA-1 molecule was addressed using the LFA-1-deficient CTL clones and LFA-1-deficient lymphoid target cells. The lytic activity of the LFA-1-deficient CTL clones was 43% of control when tested against a target cell line expressing normal levels of LFA-1 and less than 10% of control when tested against an LFA-1-deficient target cell line. These results demonstrate a direct involvement of LFA-1 in CTL-mediated cytolysis and suggest a more general dependence on LFA-1 in lymphoid cell-cell interactions.
Effect of adrenocorticotrophin on cortisol and androstenedione secretion from dispersed cells of guinea-pig adrenal zonae fasciculata and reticularis.
We have studied cortisol and androstenedione secretion by dispersed cells of the outer zona fasciculata (ZF) plus zona glomerulosa, and the inner zona reticularis (ZR) plus medulla of the guinea-pig adrenal. The ZF and ZR were microdissected apart, the cells dispersed and incubated (200 000 cells/ml) for 90 min in the presence of adrenocorticotrophin (ACTH; 500 ng/l), dibutyryl cyclic AMP (dbcAMP; 1 mmol/l), pregnenolone, 17-hydroxypregnenolone, 17-hydroxyprogesterone, 11-deoxycortisol and 21-deoxycortisol. The steroid concentrations were 5-25 mumol/l. Cortisol secretion was assayed by radioimmunoassay. There was no detectable cortisol secretion (less than 50 nmol/l) from the ZR in the controls (no additive) or after dbcAMP stimulation. Adrenocorticotrophin-stimulated cortisol secretion was also low (range less than 50-340 nmol/l). In contrast the ZF secreted 177-379 (control), 828-2052 (dbcAMP) and 2863-9735 (ACTH) nmol cortisol/l. There was no detectable (i.e. less than 2 nmol/l) cAMP production by ZR or ZF either basally (no ACTH) or after ACTH stimulation (500 ng/l). Challenge of the ZR cells with each cortisol precursor steroid (5 mumol/l) increased (P less than 0.05) cortisol secretion over that seen with the corresponding basal and ACTH-stimulated controls. Thus pregnenolone, 17-hydroxypregnenolone, 17-hydroxyprogesterone, 11-deoxycortisol and 21-deoxycortisol (converted directly to cortisol by 21-hydroxylase) gave rise to (mean +/- S.D., n = 4) 406 +/- 86, 680 +/- 180, 1307 +/- 111, 1141 +/- 234 and 3160 +/- 419 nmol cortisol/l respectively.(ABSTRACT TRUNCATED AT 250 WORDS)