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Biomedical subjects

R Jordan

Publications and source records attributed to R Jordan.

At least 109 records · Page 6Linked to original sources
PubMed1988

Antithrombin-III prevents the lethal effects of Escherichia coli infusion in baboons.

Infusion of Escherichia coli (LD100) was followed by coagulopathic and cell injury responses, cardiovascular collapse, and death in 18 to 32 hr in four out of four baboons. Infusion of AT-III in sufficient amounts to achieve AT-III levels of more than 4 units/ml of plasma before and during the infusion of E. coli reduced the intensity of the coagulopathic and cell injury response and prevented vascular collapse and death in four out of four baboons. Failure to achieve AT-III levels of more than six units/ml at T +60 min during the infusion of E. coli resulted in failure to prevent its lethal effects in three out of three baboons even though levels as high as 10 units/ml were achieved later in the course of the experiment. These studies suggest that thrombin and/or its products can contribute to the inflammatory response to E. coli and that AT-III is of potential value as a prophylactic but not as a therapeutic agent in the treatment of patients at high risk of developing gram negative sepsis.

Animals↗
PubMed1987

Beta-adrenergic activities of octopamine and synephrine stereoisomers on guinea-pig atria and trachea.

The activities of the (-)- and (+)-forms of m- and p-octopamine and m- and p-synephrine on beta 1- and beta 2-adrenoceptors in guinea-pig atria and trachea have been compared with that of noradrenaline. The rank order of potency of the (-)-forms on beta 1-adrenoceptors was noradrenaline greater than m-synephrine greater than m-octopamine = p-octopamine greater than p-synephrine. m-Synephrine was 100-fold, m- and p-octopamine about 6000-fold, and p-synephrine about 40,000-fold less active than noradrenaline. The (+)-forms were 1-2 orders of magnitude less active than their (-)-counterparts. The four (-)-compounds were more than four orders of magnitude less active than noradrenaline on beta 2-adrenoceptors, and the (+)-forms had no detectable activity in concentrations as high as 10(-4) M. If m- and p-octopamine are co-released with noradrenaline in amounts proportional to their concentration, their activities at these structures are too low to be physiologically significant.

Adrenergic beta-Agonists↗
PubMed1986

In situ and in vitro characterization of the cellular immune response in erythema nodosum leprosum.

We sought to evaluate cell-mediated immune responses in erythema nodosum leprosum (ENL), a reactional state occurring in lepromatous leprosy. Skin biopsies from patients with leprosy were studied with monoclonal antibodies against T lymphocyte antigenic determinants, interleukin 2 (IL 2), and IL 2 receptors (Tac) by using immunoperoxidase staining of frozen sections. Peripheral blood lymphocytes from 18 ENL patients were tested in vitro for lepromin-induced suppression of Con A stimulation. Serial studies of seven lepromatous patients who developed ENL during the course of the study showed increases in both the Leu-3a:Leu-2a ratio and the number of IL 2-positive cells. IL 2-positive cells comprised 0.3% of the cells in all of the ENL lesions studied as compared with the 0.03% found in nonreactional lepromatous lesions (P less than 0.001). Lepromin-induced suppression of the Con A response, present in nonreactional lepromatous patients, significantly decreased in patients developing the ENL reaction, but returned after recovery from ENL. These changes in tissues and peripheral blood suggest that the pathogenesis of ENL is related to cell-mediated immune processes. Despite these immunologic changes, however, ENL patients do not recover antigen-specific skin tests or eliminate Mycobacterium leprae.

Antibodies, Monoclonal↗
PubMed1986

Prescription: office automation.

The mission statement of Minneapolis Children's Medical Center reads, in part, "Mindful of the unique characteristics of children, MCMC's missions is to provide a team of health care professionals attuned to the special needs of the total child, at all ages from prenatal through adolescent, in a uniquely designed facility." Therefore an "open" professional staff, rather than a medical staff, was established consisting of physicians, dentists, and other health professionals with advanced degrees at the master's level or above, including, but not limited to, psychologists, social workers, clinical nurse specialists, chaplains, audiologists, and speech pathologists. This professional staff has grown to 650 members, extremely large for a 122-bed hospital. The professional staff office needed help in managing the volume of information associated with this large staff. To meet that need, in addition to the needs of other hospital areas, MCMC's administration made the decision to purchase office automation equipment and established a committee of hospital-wide users, rather than managerial staff, to survey their own needs, select vendors, and make the final recommendation. The word-processing system selected now maintains 650 physician profiles, each with 44 variables. Whereas prior to automation 25 separate lists needed to be updated each time a professional staff member was either added or deleted, now only individual physician profiles need to be adjusted. Programs were then designed to automate the many reports that must be done. In this paper we propose to describe this selection process and relate how the system developed has streamlined and simplified the work of the professional staff office to enable it to increase its output by over 300% without adding staff.

Electronic Data Processing↗
PubMed1986

Auditory brain stem responses in the mentally retarded: audiometric correlates.

In previous reports we have suggested that the auditory brain-stem responses (ABRs) of adults with Down's syndrome exhibit two abnormalities unique to that population: a shortened central conduction time and an insensitivity of peak latencies to increases in stimulation rate. The current experiment assessed the possibility that these abnormalities were caused by hearing deficit rather than central auditory dysfunction. The ABRs of a group of adults with Down's syndrome were compared with those of a group of non-Down retarded and a control group of nonretarded adults. An audiometric examination consisting of pure-tone audiograms, tympanometry, and acoustic reflexes was given to all the retarded subjects. The incidence of serious hearing deficit in the Down's syndrome group was 73% compared to 22% in the non-Down retarded. Regardless of hearing status, the central conduction times in the Down group were shorter than in either of the other groups. The abnormal response to stimulation rate, however, was found to reflect high-frequency hearing loss and not central auditory dysfunction. The data suggest that a battery of objective tests including tympanometry, acoustic reflexes, and selected ABR measures may be useful in identifying hearing deficit in both Down-syndrome and non-Down retarded individuals.

Acoustic Impedance Tests↗
PubMed1985

Gonoblennorrhoea adultorum (gonococcal conjunctivitis)--a "disappearing disease" which does not disappear.

Gonoblennorrhoea adultorum (GA) still occurs in spite of contrary statements. During the last 10 years, 4 cases were seen in the Munich Clinic of Dermatology (constituting 0.19% of all patients with gonorrhoea). While the conjunctivae alone were involved in 3 of them, in 1 the cornea showed alterations as well. Thus, the disease has not lost its potential danger. Yet the newer cephalosporins seem to cure GA rapidly, even if given in a single dose (together with local treatment).

Adult↗
PubMed1985

Primary intracranial immunoblastic lymphoma in infancy.

Primary intracranial lymphoma is uncommon in any age group, but it is especially rare in childhood. This report describes a previously healthy, 14-month-old female infant who developed a primary intracranial immunoblastic (probable B-cell) lymphoma which remained confined to the central nervous system until the time of death, 23 months after diagnosis. She appears to be the youngest patient with documentation of such a diagnosis by light and electron microscopy and by histochemical and immunoperoxidase studies. An immunological investigation was negative. Significant maternal and paternal family histories of malignancy suggest that a genetic predisposition, combined with postzygotic events such as viral infection, may be responsible for this familial cluster of tumors, and for this patient's unusual presentation.

Brain Neoplasms↗
PubMed1982

Pharmacological properties of diacetolol (M & B 16,942), a major metabolite of acebutolol.

Diacetolol (M & B 16,942), the major metabolite of the beta-adrenoceptor blocking agent, has been compared pharmacologically with acebutolol. In vitro, the beta-adrenoceptor blocking potency of diacetolol was less than that of acebutolol but its cardioselectivity (atrial relative to tracheal tissue) was greater. In the anaesthetized cat both agents had closely similar beta-adrenoceptor blocking potency and cardioselectivity. Diacetolol had weak intrinsic sympathomimetic activity (ISA), and no significant membrane-stabilizing activity (MSA). It did not restore sinus rhythm to anaesthetized dogs with ouabain-induced arrhythmias but was similar to acebutolol in preventing arrhythmia induced by adrenaline/methylchloroform in anaesthetized cats. It is concluded that, in experimental animals, diacetolol has beta-adrenoceptor blocking properties and ISA similar to the parent compound but differs in its lack of MSA.

Acebutolol↗
PubMed1982

[Spatial population distribution and development: notes on urban settlements in Latin America].

The relationship between population distribution and development trends is analyzed, with attention to the planning of spatial redistribution policies. Some shortcomings in the investigation of the causes and consequences of urbanization are discussed. The second part of the article "refers to some spatial demographic and socio-economic expressions of the urbanization process in Latin America, the population concentration trends and their relationships with changes in agrarian structure and industrialization, social stratification patterns and forms of urban space organization.... The paper concludes with some critical notes on the theses related to 'optimum' size of urban centres and to 'balanced development' of urban systems, on which some policy proposals have been based." (summary in ENG)

Agriculture↗
PubMed1980

Cushing syndrome: current concepts of diagnosis and therapy.

A variety of diagnostic advances including radioimmunoassay of adrenocorticotropic hormone (ACTH) have increased the number of methods for laboratory investigation of Cushing syndrome.* However, experience with these procedures has led to a recognition of their limitations. We have developed an algorithm which incorporates these newer techniques and minimizes the number of procedures required to diagnose the various causes of Cushing syndrome. At present, we recommend pituitary surgical operations for pituitary-dependent Cushing syndrome because we believe this disease is caused by the development of a pituitary ACTH-secreting tumor.

Cushing Syndrome↗
PubMed1979

Fractionation of low molecular weight heparin species and their interaction with antithrombin.

Preparations of low molecular weight porcine heparin with an average specific anticoagulant activity of 94 units/mg were fractionated into "active" and "relatively inactive" forms of the mucopolysaccharide of approximately 6000 daltons each. The active fraction was further subdivided into various species with descending but significant affinities for the protease inhibitor as well as decreasing but substantial anticoagulatn potencies. "Highly active" heparin (approximately 8% of the low molecular weight pool) possesses a specific anticoagulant activity of 350 +/- 10 units/mg. The relatively inactive fraction (67% of the low molecular weight pool) exhibits a specific anticoagulant activity of 4 +/- 1 units/mg. The binding of highly active heparin to antithrombin is accurately described by a single-site binding model with a KHep-ATDISS of approximately 1 X 10(-7) M. Variations in this binding parameter secondary to changes in environmental variables indicate that charge-charge interactions as well as an increase in entropy are critical to the formation of the highly active heparin-antithrombin complex. The interaction of relatively inactive heparin with the protease inhibitor is characterized by an apparent KHep-ATDISS of 1 X 10(-4) M. In large measure, this is due to small amounts of residual active mucopolysaccharide (0.5%). The ability of the highly active heparin to accelerate the thrombin-antithrombin interaction was also examined. We were able to demonstrate that the mucopolysaccharide acts as a catalyst in this process and is able to initiate multiple rounds of enzyme-inhibitor complex formation. The rate of enzyme neutralization is increased to a maximum of 2300-fold as the concentration of heparin is raised until the inhibitor is saturated with mucopolysaccharide. Further increases in heparin concentration result in a reduction in the speed of enzyme neutralization. This appears to be due to the formation of thrombin-heparin complexes. A mathematical model is given which provides a relationship between the initial velocity of enzyme neutralization and reactant concentrations.

Antithrombins↗
PubMed1979

Tone-segregation by phase: on the phase sensitivity of the single ear.

A monaural complex tone is synthesized from 12 harmonically related pure tones, played in phase. In each of 12 segments, one of the tones (the target) is played out of phase so that the sequence of targets is increasing or decreasing in frequency. If the target is at least 30 degrees out of phase, the targets are perceptually segregated. This tone-segregation by phase raises doubts concerning several current theories of pitch perception. The phenomenon is conjectured to be caused by the ear's nonlinear compressive transfer characteristic or by a temporal analysis of the stimulus.

Acoustic Stimulation↗