Selective attrition of non-recirculating T cells during normal passage through the lung vascular bed.

Transient arrest of T lymphocytes in the lung vascular bed following infusion of cells subjected to in vitro manipulations has been recognized for many years as a troublesome 'artefact', and has generally been attributed to trauma-induced changes in lymphocyte surface membranes. However, a number of laboratories have reported that the trapping process also occurs under situations where lymphocyte surface damage is minimal or absent, suggesting that the phenomenon may represent an intrinsic component of normal lymphocyte circulation. Consistent with these suggestions, recent studies from our laboratory have demonstrated the presence of large numbers of T cells in collagenase digests of normal peripheral lung tissue, which cannot be removed by broncho-alveolar lavage or perfusion of the tissue vascular bed.

Hypertension Prevention Trial (HPT): food pattern changes resulting from intervention on sodium, potassium, and energy intake. Hypertension Prevention Trial Research Group.

The Hypertension Prevention Trial (HPT) was a multicenter randomized trial designed to assess the effects of long-term dietary changes on blood pressure in a normotensive population (diastolic blood pressure greater than or equal to 78 but less than 90 mm Hg) for a period of 3 years. The dietary treatments were reduction of sodium intake, increase of potassium intake, and decrease of energy intake. Estimates of changes in food intake were made by comparing 24-hour food records of the treatment and control participants.

The effect of hypermagnesemia on serum levels of osteocalcin in an animal model.

Using a pregnant goat (Capra hircus) model to study the in vivo effects of hypermagnesemia on serum osteocalcin concentration, magnesium sulfate infusion has been shown to increase circulating levels of osteocalcin. At 2 h after the administration of magnesium sulfate, a 98% increase in Mg2+ concentration over the basal level resulted in: a 38% increase in serum osteocalcin concentration over baseline; a 22% decrease in PTH concentration, and no change in total and ionized calcium concentrations. These in vivo data support previous in vitro results demonstrating that Mg2+ is a potent inhibitor of osteocalcin binding to hydroxyapatite.

Development of an immunoaffinity process for factor IX purification.

An immunoaffinity process based on monoclonal antibody (MAb) to factor IX (FIX) has been developed. Initially, vitamin-K-dependent proteins from cryoprecipitate-poor plasma are isolated on DEAE-Sephadex. The eluate is applied to an immunoaffinity column that utilizes a divalent metal-ion-dependent MAb directed against FIX.

Efficacy of nalbuphine as a parenteral analgesic for the treatment of painful episodes in children with sickle cell disease.

Painful episodes of sickle cell disease remain a source of frustration to patients and health care providers because of the lack of interventions to prevent or control them. Nalbuphine is a potent semisynthetic agonist/antagonist analgesic. We report our experience using nalbuphine as a treatment for painful episodes of sickle cell disease in children.

Conformational changes in an epitope localized to the NH2-terminal region of protein C. Evidence for interaction of protein C domains.

Murine monoclonal antibodies, developed following immunization with human protein C, were characterized for their ability to bind antigen in the presence of either CaCl2 or excess EDTA. Three stable clones were obtained which produced antibodies that bound to protein C only in the presence of EDTA. All three antibodies bound to the light chain of protein C on immunoblots and also bound to the homologous proteins factor X and prothrombin in solid-phase radioimmunoassays.

Fetal monitoring and predictions by clinicians: observations during a randomized clinical trial in very low birth weight infants.

Predictions about perinatal outcome in very low birth weight infants were studied in a randomized clinical trial of electronic fetal monitoring and periodic auscultation to assess the effect of diagnostic monitoring information on clinicians' ability to predict perinatal outcomes. The only predictions consistently correct before monitoring information was available were those regarding infant survival (88% correct, kappa [kappa] = 0.40, P less than .

Reaction of proteinases with alpha 2-macroglobulin: evidence for alternate reaction pathways in the inhibition of trypsin.

Titration experiments were employed to measure the binding stoichiometry of alpha 2M for trypsin at high and low concentrations of reactants. These titration experiments were performed by measuring the SBTI-resistant trypsin activity and by direct binding measurements using 125I-labeled trypsin. The binding stoichiometry displayed a marked dependence upon protein concentration.

Maternal height and weight gain during pregnancy as risk factors for cesarean section.

Maternal height, maternal weight, infant weight, and maternal weight gain during pregnancy were examined as factors associated with the likelihood of delivery by cesarean section for cephalopelvic disproportion (CPD). Sixty-four women, delivered by cesarean section for CPD, were compared with matched controls who delivered vaginally. The only factor associated with an increased risk of cesarean section for CPD was short stature: women shorter than 63 inches were 4.

Electron microscope studies of human alpha 2-macroglobulin-chymotrypsin complex: demonstration that the two structures assigned to native and proteolyzed alpha 2-macroglobulin represent two views of the proteolyzed molecule.

Electron microscope studies of native and protease-bound human alpha 2-macroglobulin have led to two contradictory models for these two structures. One viewpoint maintains that the native structure has the shape of )+(, which contracts on binding of the protease to the shape of ([). An opposing view proposes that the native structure has the shape of a padlock and that )+( and ([) are the side and end views of the proteolyzed molecule.

The effect of interobserver variation in dating endometrial histology on the diagnosis of luteal phase defects.

Endometrial biopsy specimens (n = 62) were evaluated by five pathologists to assess the effect of interobserver variation on histologic dating of the endometrium. The potential effect of this variation on the diagnosis of luteal phase defects (LPDs) and resulting clinical management was also determined. Mean (+/- standard error) interobserver variation was 0.

Evidence that the platinum-reactive methionyl residue of the alpha 2-macroglobulin receptor recognition site is not in the carboxyl-terminal receptor binding domain.

Digestion of human alpha 2-macroglobulin-methylamine (alpha 2M-CH3NH2) with papain prior to gel filtration resulted in the resolution of three distinct peaks. The material in peak I (Mr approximately 600,000) and peak II (Mr approximately 55,000) did not have any receptor binding ability as determined by in vivo clearance studies and in vitro competitive binding studies using mouse peritoneal macrophages. In contrast, the material in peak III (Mr approximately 20,000) bound to macrophage alpha 2-macroglobulin (alpha 2M) receptors with a Kd of 250 nM.

Use of anti-idiotypic antibodies to establish that monoclonal antibody 7H11D6 binds to the alpha 2-macroglobulin receptor recognition site.

Studies were performed to determine if monoclonal antibody 7H11D6 binds to the region of alpha 2-macroglobulin (alpha 2M) that interacts with cell-surface receptors. F(ab')2 fragments prepared from this antibody delayed the in vivo clearance of alpha 2M-trypsin complexes from the murine circulation and blocked the in vitro binding of 125I-labeled alpha 2M-trypsin to rat kidney fibroblasts. Chemical modification studies revealed that the epitope region for 7H11D6 is sensitive to modification of the inhibitor with cis-dichlorodiammineplatinum (II).

The dynamic relations among interpersonal behaviors: a test of complementarity and anticomplementarity.

On the basis of the positions of behaviors relative to one another in the interpersonal circle, the principles of complementarity and anticomplementarity specify how people's behaviors influence one another in interpersonal interactions. Pairs of undergraduate women (1 subject, N = 80, and 1 confederate) collaborated for 16 min to create and agree on stories for two pictures. Confederates performed scripted roles that emphasized one of eight interpersonal behaviors.

Characterization of a protein C activator from the venom of Agkistrodon contortrix contortrix.

An enzyme capable of activating protein C has been purified 60-fold from the venom of the Southern copperhead snake (Agkistrodon contortrix) by ion-exchange and gel filtration chromatography. The purified enzyme consists of a single polypeptide with an apparent molecular weight of 37,000. The isoelectric point of the protein C activator was determined to be 6.

Identification of a monoclonal antibody specific for a neoantigenic determinant on alpha 2-macroglobulin: use for the purification and characterization of binary proteinase-inhibitor complexes.

A monoclonal antibody was obtained from the fusion of spleen cells of mice, immunized with methylamine-treated alpha 2-macroglobulin (alpha 2M), with the myeloma cell line P3-X63-Ag8.653. A competitive binding assay demonstrated that the antibody was specific for a neoantigen expressed on alpha 2M when the inhibitor reacts with proteinases or with methylamine.

Characterization of the reaction of plasmin with alpha 2-macroglobulin: effect of antifibrinolytic agents.

The reaction of several plasmin derivatives with alpha 2-macroglobulin (alpha 2M) has been investigated. Titration experiments measuring conformational changes in alpha 2M, changes in the number of sulfhydryl groups available for titration with 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB), and changes in the ability of alpha 2M to protect bound plasmin from inhibition by soybean trypsin inhibitor all suggested that between 1.3 and 1.

A randomized trial of dexamethasone and acetazolamide for acute mountain sickness prophylaxis.

Forty-seven climbers participated in a double-blind, randomized trial comparing acetazolamide 250 mg, dexamethasone 4 mg, and placebo every eight hours as prophylaxis for acute mountain sickness during rapid, active ascent of Mount Rainier (elevation 4,392 m). Forty-two subjects (89.4 percent) achieved the summit in an average of 34.