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Biomedical subjects

R Pierce

Publications and source records attributed to R Pierce.

At least 55 records · Page 3Linked to original sources
PubMed1990

Immunological crossreactivity between the human immunodeficiency virus type 1 virion infectivity factor and a 170-kD surface antigen of Schistosoma mansoni.

A monoclonal antibody (mAb) directed against a synthetic peptide derived from the sequence of the human immunodeficiency virus type 1 (HIV-1) regulatory protein virion infectivity factor (vif) labeled the surface of Schistosoma mansoni schistosomula by indirect immunofluorescence. Western blotting showed that two S. mansoni proteins of 170 and 65 kD were recognized by the mAb. Sera from 20% of S. mansoni-infected HIV-seronegative individuals tested recognized the PS4 peptide in an ELISA as did sera from S. mansoni-infected rats. Sera from individuals seropositive for HIV-1, but without schistosomiasis, that reacted with the vif peptide also recognized a 170-kD S. mansoni protein. This crossreactive S. mansoni antigen appears to be a target of immunity in vivo since passive transfer of the mAb VIF-CD3 to naive rats had a protective effect against a challenge infection with S. mansoni cercariae.

Amino Acid Sequence↗
PubMed1990

Florida red-tide toxins (brevetoxins) produce depolarization of airway smooth muscle.

Crude preparations of brevetoxin (PBTX) produce airway contraction; however, it is not known if this toxin-induced mechanical response is coupled to changes in airway smooth muscle membrane potential. Membrane potentials and contractility of in vitro canine trachealis smooth muscle preparations were simultaneously measured with a microelectrode and microforce transducer before and during exposure to either the crude toxin (0.01-1.2 micrograms/ml), or the purified fractions PBTX-2 or PBTX-3 (0.01-0.07 micrograms/ml). Membrane potentials in cultured airway smooth muscle-reaggregate preparations were similarly studied. Toxins produced concentration-dependent depolarizations and contractions in in vitro preparations. These responses were not obtained in the presence of either the muscarinic blocking agent atropine, the sodium channel blocker tetrodotoxin (TTX), 0 mM extracellular Ca2+, or the Ca2+ channel blocker verapamil. The toxins were without effect in cultured cells, whereas acetylcholine produced depolarizations which were blocked in the presence of atropine, but not TTX. This suggested the presence of functional cholinergic receptors in cultured cells, and the PBTX-induced release of endogenous acetylcholine from peripheral nerve endings in the in vitro airway smooth muscle response.

Acetylcholine↗
PubMed1990

Brief upper airway (laryngeal) dysfunction.

We describe in six men, recurrent episodes recurring over months or years, of sudden, brief complete obstruction to respiration followed by dyspnoea with loud inspiratory stridor lasting two to five minutes. Attacks occurred during wakefulness and/or sleep. In one patient an episode was witnessed endoscopically: the initial obstruction was seen to be caused by complete laryngeal closure. The false vocal cords then opened, but the vocal cords remained adducted and caused inspiratory stridor. The similarity of the attacks described by the other patients suggests that they were all caused by laryngeal closure. Furthermore, they could simulate the episodes by voluntarily adducting their vocal cords. The symptoms were usually preceded by a sensation of throat irritation and in four cases symptoms of upper respiratory infection were present. Associated features present in some of the patients included post-nasal discharge, snoring, sleep apnoea and gastro-oesophageal reflux. None was hypocalcaemic. Although stimulation of laryngeal receptors is known to produce reflex laryngeal closure, cough is the usual response during wakefulness. Treatment aimed at reducing upper airway irritation and voluntary inhibition of coughing appeared successful in reducing the incidence and severity of the episodes. Recognition of the condition is important as it may be confused with other causes of acute dyspnoea and it appears to respond to specific management.

Adult↗
PubMed1990

Increased release of the N-terminus of the atrial natriuretic factor prohormone with increasing absolute atmospheres of pressure in a hyperbaric chamber and reversal with oxygen therapy.

Increasing atmospheres of absolute pressure (ATA) on the cardiopulmonary system results in a marked diuresis. The present investigation was designed to determine if the diuresis observed with increasing ATA is associated with increased release of the N-terminus of the atrial natriuretic factor (ANF) prohormone that contains two potent diuresis-producing hormones consisting of amino acids (aa) 1-30 (pro ANF 1-30; long-acting sodium stimulator) and aa 31-67 (pro ANF 31-67; vessel dilator) of this 126 aa prohormone. Seven healthy volunteers (mean age, 31 years) had the circulating concentration of the N-terminus of the ANF prohormone evaluated at 1, 2, and 3 ATA in a monoplace hyperbaric chamber by two specific and sensitive radioimmunoassays that immunologically recognize (1) the whole 98 aa N-terminus and (2) the midportion of the N-terminus consistent with aa 31-67 (pro ANF 31-67). With increasing ATA from 1 (sea level) to 2 (equivalent to 33 feet of sea water), the circulating concentrations of both the whole N-terminus and pro ANF 31-67 increased threefold. At 3 ATA (66 feet of sea water), their circulating concentrations increased sixfold over their concentrations, at 1 ATA. With the addition of 100 percent O2 while at 3 and 2 ATA, the circulating concentrations of both the whole N-terminus and pro ANF 31-67 immediately decreased to their prehyperbaric ATA levels and remained there with further decompression to 1 ATA and removal of O2 supplementation. The increased circulating concentration of the N-terminus of the ANF prohormone containing two peptides with potent diuretic effects during increasing atmospheres of absolute pressure may help to explain the diuresis that has been observed with increasing ATA.

Adult↗
PubMed1989

Serum levels of beta-carotene, vitamin A, and zinc in male lung cancer cases and controls.

The mean serum levels of beta-carotene and vitamin A in a multivariate analysis of data from 64 histologically confirmed male lung cancer cases were statistically significantly lower than those from 63 randomly selected male hospital controls, who were admitted for small surgical operations (p values for both beta-carotene and vitamin A less than 0.001). The mean serum levels of zinc were not statistically significantly different between cases and controls (p = 0.10). The levels of beta-carotene, vitamin A, or zinc were not statistically significantly influenced by either the extent of the cancer (p = 0.45) or the cancer cell type (p = 0.06). The possible biological significance of these findings is discussed briefly.

Adenocarcinoma↗
PubMed1989

Release of atrial natriuretic factor with increasing absolute atmospheres of pressure in a hyperbaric chamber and reversal with oxygen therapy.

Diving is associated with a marked diuresis which can be accurately reproduced in a hyperbaric chamber where the pressure of a specific depth can be precisely controlled. The present investigation was designed to determine if the diuresis observed with diving is associated with increased release of a new diuresis-producing hormone, atrial natriuretic factor (ANF). Seven experienced divers (3 men and 4 women; average age of 31 years) had their circulating concentration of atrial natriuretic factor measured at 1, 2 and 3 atmospheres of absolute pressure (ATA) in a monoplace hyperbaric chamber while breathing air. With the simulated dive to 33 feet (2 ATA), the circulating concentration of ANF increased 3-fold and at a depth of 66 feet (3 ATA) ANF increased 6-fold over the concentration at 1 ATA. With the addition of 100% oxygen while at depths of 33 and 66 feet, the concentration of ANF immediately decreased to its pre-dive concentration and remained there with further decompression to surface air and removal of oxygen supplementation. Thus, the increased release of ANF with depth may help to explain the diuresis observed with diving.

Adult↗
PubMed1986

Protection against experimental Schistosoma mansoni schistosomiasis achieved by immunization with schistosomula released products antigens (SRP-A): role of IgE antibodies.

Schistosomula-released products (SRP-A) have been shown to induce preferentially a significant IgE response against Schistosoma mansoni schistosomula when injected into rats, in the absence of adjuvant. The present work provides additional evidence of the in vivo relevance of the anti-SRP-A target antigens. Two strains of rat (Brown Norway and Fischer) were immunized with SRP-A and infected percutaneously. A significant level of protection (up to 83% reduction in worm burden) was observed. Passive transfer experiments carried out with anti-SRP-A or IgE-depleted anti-SRP-A sera suggested the preponderant role of antibodies and particularly of IgE in the protective immunity developed by Fischer rats. Platelets and macrophages recovered from such immunized rats had surface IgE as demonstrated by immunofluorescence analysis with FITC anti-IgE, and have been shown to be directly cytotoxic for schistosomula. The chemiluminescence observed when the macrophages were incubated with anti-IgE suggested the presence of IgE on the surface of these cells.

Animals↗
PubMed1985

The sexually abused child: a comparison of male and female victims.

Although the amount of research dealing with child sexual abuse is rapidly increasing, there have been very few attempts to identify and compare variables that characterize differences between female and male victims. To address this void, 25 substantiated cases of sexual abuse involving male children were compared with 180 substantiated cases of sexual abuse of female children. Significant differences between female and male victims were observed in the following areas: family composition, the perpetrator of the abuse, variables contributing to the continuation of the abusive situation, and the type of services provided to the sexually abused child and family. Implications for treatment are offered.

Adult↗
PubMed1985

IgG response of rats and humans to the released products of schistosomula of Schistosoma mansoni.

The participation of products released from Schistosoma mansoni schistosomula (SRP-A) in the IgG antibody response of infected Brown-Norway rats and infected humans has been studied using immunoprecipitation with various antigenic preparations and in in vitro cytotoxicity assays. A large number of SRP-A molecules with a wide range of molecular weights was recognized by infected rat and human sera. Anti-SRP-A antibodies appeared in rat sera from day 28 after infection. In infected humans, a variable pattern of SRP-A recognition was observed between individuals. IgG antibodies obtained by immunization of rats with SRP-A without addition of adjuvants reacted with 3 major schistosomula surface proteins with molecular weights of 38, 32 and 21 kDa. These latter molecules were also revealed strongly by infected rat sera. Moreover, these antibodies were able to kill schistosomula in vitro in the presence of complement or eosinophils.

Animals↗
PubMed1985

Retrieval of renal function by revascularization. Study of preoperative outcome predictors.

Results of renal revascularization for retrieval of function in poorly functioning kidneys are variable, but criteria for prediction of benefit and patient selection for operation are ill-defined. This report examines preoperative parameters in 64 hypertensive patients who underwent successful revascularization of poorly functioning kidneys as defined by creatinine clearance less than or equal to 15 ml/min (measured by preoperative split renal function studies [SRFS]) or preoperative serum creatinine greater than or equal to 3.5 mg/dl (range: up to 8.9 mg/dl) to identify markers of value in prediction of a beneficial response in renal function. Ages ranged from 35 to 75 years. There were 35 men and 29 women. The renovascular lesion was atherosclerotic in 58 patients and fibrodysplastic in six. Total renal artery occlusion was present in 32 cases. No urine flow was detectable before surgery on SRFS from 13 kidneys. Kidney lengths ranged from 7.7 cm to 15.1 cm. Fifty-four unilateral and 10 bilateral revascularizations were performed. A beneficial blood pressure response to operation was observed in 94%. Benefit in excretory function was determined by comparison of preoperative and postoperative data which included SRFS parameters, renal length, serum creatinine, isotopically derived split functioning renal mass, and glomerular filtration rates. Overall, 56 patients could be classified in regard to functional response. Twenty-two patients received no or minimal benefit; nine patients received modest improvement, and 25 patients exhibited more marked improvement. Statistical evaluation of preoperative anatomic and functional parameters as predictors of functional response suggested that multiple variables influence the probability of function retrieval by revascularization. Useful among these predictive variables are the status of the distal vessel beyond the occlusion, the bilaterality of reconstructable disease in azotemic patients, the amount of residual renal mass available for revascularization, and the degree of hyperconcentration of nonreabsorbable solutes from the involved kidney after surgery.

Adult↗
PubMed1985

Serodiagnosis of toxoplasma infection using a purified parasite protein (P30).

The major surface protein (P30) of Toxoplasma gondii has been purified by immunoabsorption with anti-P30 monoclonal antibodies linked to a glutardialdehyde activated affinity absorbant. SDS-PAGE analysis of the eluted material followed by silver staining showed only a single band of 30,000 mol wt. Western blotting using antibodies from a rabbit immunized with purified P30 against the total Toxoplasma extract separated by SDS-PAGE again revealed an unique antigen of 30,000 daltons. The presence of repeated epitopes within P30 was confirmed by a two-site/one-antibody radiometric assay with the purified protein. Sandwich ELISA procedures with purified P30 clearly demonstrated that all 37 tested patients with acute toxoplasmosis presented significantly high levels of IgM anti-P30 antibodies. In addition, all 40 tested patients with chronic toxoplasma infection also showed high IgG anti-P30 antibody levels. These findings represent an essential step for the development of new reagents for the diagnosis of toxoplasmosis.

Antigens, Protozoan↗