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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
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↗
PubMed1975

Sexual impotence: a double-blind study of LHRH nasal spray versus placebo.

A double-blind study comparing application of 1.0 mg LHRH nasal spray per day against a placebo was performed in a group of 20 sexually impotent patients in whom no clinical endocrinological pathology was evident. After a 2-week placebo-spray period, LHRH was given for 4 weeks. A 2-week placebo-spray period followed. A better therapeutic effect was seen in the LHRH as opposed to the placebo group (p = 0.024) 4-6 weeks after cessation of LHRH medication. After 4 weeks of LHRH medication there were no changes in basal LH/FSH levels or in the LH response after administration of 25 mug LHRH. The FSH response was, however, significantly lower.

Administration, Intranasal↗
PubMed1974

A comparison of the experimental anti-arrhythmic properties of acebutolol (M and B 17,803), propranolol and practolol.

1 The beta-adrenoceptor blocking agent, acebutolol (M & B 17,803), has been compared with propranolol, practolol, lignocaine and quinidine for its ability to revert or prevent various types of experimental arrhythmias.2 By intravenous infusion, acebutolol had one half the potency of propranolol in reverting an established ouabain-induced ventricular arrhythmia in the anaesthetized dog. Practolol was ineffective in the conditions used.3 High oral doses of acebutolol or propranolol significantly increased the arrhythmic dose of ouabain in the conscious rabbit. Similar doses of practolol produced a significant decrease (i.e. potentiation) in the dose of ouabain required to produce arrhythmia. Lignocaine and quinidine showed no or little activity in this test.4 Propranolol, acebutolol and practolol were all effective in decreasing the frequency of ectopic beats induced by adrenaline and methylchloroform in the anaesthetized cat. Lignocaine and quinidine were only weakly effective.5 Acebutolol and propranolol were equally effective either intravenously or orally in reducing the incidence of ventricular fibrillation produced by chloroform in mice.6 It is suggested that the wide spectrum of experimental anti-arrhythmic activity of acebutolol coupled with its cardioselectivity may make it an interesting compound in the treatment of cardiac arrhythmias in man.

Administration, Oral↗
PubMed1973

Beta-adrenoceptor blocking properties and cardioselectivity of M & B 17,803A.

1. The beta-adrenoceptor blocking properties of (+/-)-1-(2-acetyl-4-n-butyramidophenoxy)-2-hydroxy-3-isopropylaminopropane hydrochloride (M&B 17,803A) have been compared with those of practolol and propranolol in the guinea-pig, cat and dog.2. Following either intravenous or oral administration in the cat or dog, M&B 17,803A and practolol had similar potency in antagonizing isoprenaline-induced tachycardia and both showed cardioselectivity, but both were less potent than propranolol.3. M&B 17,803A and practolol had approximately one hundredth the intravenous potency of propranolol in increasing the severity of anaphylactic bronchospasm in the conscious sensitized guinea-pig.4. M&B 17,803A possessed less marked intrinsic sympathomimetic activity than practolol but, like propranolol, it had significant local anaesthetic properties and increased the refractory period of rabbit isolated atria.

Acetanilides↗