bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Pharmacokinetic Characteristics of Beta‐Receptor Antagonists in Man—Similarities and Differences of Clinical Relevance
Authors: Riess W. , Brechbühler S. , Theobald W. 
Published: March 2008

Summary: The pharmacokinetic characteristics of beta‐receptor antagonists in man—Similarities and differences of clinical relevance.The aliphatic partial structure common to the beta‐receptor antagonists leads to similar products of their biotransformation. The main qualitative and quantitative differences of the metabolism of the compounds of this class, however, rest in the nature of their aromatic or heterocyclic substituents.The physico‐chemical properties of the beta‐blockers appear to be predominantly responsible for the extent of metabolic degradation and for the distribution in the body, especially for the binding to proteins. As a consequence of their different biological disposition the clinically relevant systemic bioavailabilities of the various beta‐blockers from oral doses differ drastically.Practolol maintains an extreme position among all other compounds: It is most hydrophilic, it is not bound to proteins, it is metabolized least, but cleared renally in unchanged form to 85% of the dose. Despite its extremely high systemic bioavailability, relatively high daily doses were required for therapy. The receptor sensitivity for practolol has been rated 2 to 3 powers of 10 lower than of propranolol.Comparative pharmacokinetic assessment of beta‐receptor antagonists requires quantitative analytical data in clinically representative groups of patients. This has been demonstrated by respective studies with oxprenolol. The intra‐and inter‐individual systemic bioavailability, the differential analysis of plasma and erythrocytes, the multiexponential elimination kinetics, and their possible dependence on the dose have been studied as clinically relevant pharmacokinetic characteristics.The continuing attempt of the pharmaceutical industry to optimize the properties of beta‐blockers also has taken advantage of the slow release principle in oral dosage forms as shown by the example of oxprenolol.The beta‐receptor antagonists belong to one of the youngest classes of pharmaceuticals. Pharmacokinetic and metabolic data for the different representatives of this class have been generated in different laboratories with different approaches and different techniques. Therefore, full comparative documentation is still incomplete.
Pharmacodynamic Studies on the Antihypertensive Effectiveness of Beta‐Blocking Drugs
Authors: Taylor S. H. 
Published: March 2008

Summary: Pharmacodynamic studies on the antihypertensive effectiveness of beta‐blocking drugs.Beta‐adrenoceptor antagonists are effective antihypertensive agents in the majority of patients with uncomplicated essential hypertension. Their antipressor activity is greater on systolic than diastolic pressure and greatest during dynamic exertion. Their circulatory effects are maximum within 1–2 hours of ingestion and the antipressor effects of a single dose are detectable for over eight hours. Both the immediate and long‐term blood pressure lowering effects of these drugs are dose related. The reduction in exercise systolic pressure is related to the logarithm of the dose of each drug; the reductions in pressure at rest follow no simple mathematical function. There is wide individual variation in the plasma concentrations achieved after a given oral dose, although the averaged values follow a linear regression. There are wide discrepancies between plasma concentration profile and magnitude and duration of antihypertensive activity; blood pressure lowering activity persists for significantly longer than the drug is detectable in plasma. The antihypertensive effects of the beta‐blocking drugs are enhanced during chronic administration without habituation. Their effects are specific but independent of the immediate presence of the drug, i.e. blood pressure lowering activity persists after clearance of the drug from the body. The ancillary pharmacological properties of these drugs neither augment nor detract from their antihypertensive potency, although the possession of intrinsic vasodilator activity enhances reduction in the blood pressure standing at rest. Beta‐blocking drugs add a new dimension to antihypertensive treatment in their specific potential to reduce the coronary consequences of the disease.
Blood Pressure Variability in Patients on Beta‐Blockers
Authors: West M. J. , Honour A. J. , Sleight P. , Littler W. A. 
Published: March 2008

Summary: Blood pressure variability in patients on beta‐blockers.The direct arterial blood pressure was monitored over 24 hours in unrestricted untreated patients in order to obtain the average pressure and standard deviation over 24 hours. The standard deviation was taken as the index of variability of pressure. In eight subjects the study was repeated three months after commencement of treatment with a beta‐adrenergic blocking agent (tolamolol, 300 mg/day). In these subjects tolamolol resulted in a fall in mean blood pressure from 107 to 92 mmHg (P < 0.05) and a fall in heart rate from 82 to 70 beats per minute (P ≤ 0.01). The variability in blood pressure, however, was unaffected by treatment.
A Beta‐Blocker‐Based Antihypertensive Drug Program Guided by Age and Renin
Authors: Bühler F. R. , Lütold B. E. 
Published: March 2008

Summary: A beta‐blocker‐based antihypertensive drug program guided by age and renin.From analyses of the effectiveness of beta‐blocker monotherapy in relation to the patient's age and to pre‐treatment renin determinations an antihypertensive drug program is proposed in which beta‐blockers form the cornerstone.Patients with essential hypertension can be subdivided into groups with low (19%), normal (59%), or high (23%) renin sodium index. The proportion with low renin hypertension increases with age. Patients with high renin fall into two categories: younger patients with fairly mild hypertension and older patients with more severe hypertension and signs of renal disease.The antihypertensive efficacy of beta‐blocker monotherapy is best in high renin forms, good but less consistent in normal renin patients and uniformly bad in low renin hypertensives. In relation to age, beta‐blockers normalized blood pressure (≤ 95 mmHg diastolic) in three‐quarters of the younger than 40‐year‐olds, in about half of those aged 40–60 years, but in only 20% of those aged over 60 years.On this basis, it is postulated that the older patients with a low renin exhibit a relatively hypoadrenergic state while those with a normal or high renin—for a given age and elevated pressure—have a relatively increased adrenergic nervous activity.Because the beta‐blockers have a potent suppressive action on the renin‐angiotensin system—and, as a consequence, on angiotensin vasoconstriction, aldosterone volume expansion and central stimulatory feedback mechanisms—their antihypertensive mode of action may be linked to an important extent, though not exclusively, to renin suppression.
The Vasodilator—Beta‐Blocker Interaction—Some Determinants of its Clinical Success
Authors: Zacest R. 
Published: March 2008

Summary:The vasodilator—beta‐blocker interaction—Some determinants of its clinical success.A number of structurally dissimilar compounds, sharing the ability to induce vasodilatation have come into clinical usefulness as antihypertensive drugs. Their successful utilisation often depends critically on an appropriate combination with diuretics and beta‐blockers. Beta‐blockers can specifically inhibit the reflex cardiac stimulation which otherwise may limit the tolerability and haemodynamic value of these drugs. A synergistic antihypertensive effect has been demonstrated with hydrallazine and propranolol and possibly exists with other combinations.Generally, vasodilators are not first‐line drugs in chronic therapy but are best added to beta‐blockers.Variations of the dose‐response and the time‐course of effect are stressed as being important determinants of a successful interaction.
Centrally Acting Alpha‐Adrenoceptor Agonists in Hypertension: Mechanisms and their Role in Therapy
Authors: Dollery C. T. 
Published: March 2008

Summary: Centrally acting alpha‐adrenoceptor agonists in hypertension: Mechanisms and their role in therapy. C. T. Dollery, Aust. N.Z. J. Med., 1976, 6, pp. 88–94.Experimental work in animals has shown that both methyldopa and clonidine lower the blood pressure predominantly by an action on the central nervous system. This action is due to alpha‐adrenoceptor stimulation by clonidine and by alpha‐methyl‐noradrenaline. The evidence for a central site of action for these drugs in man is indirect but persuasive. Both drugs lower blood pressure and heart rate without causing much postural or exercise hypotension. Sympathetic responses like the overshoot of pressure following Valsalva's manoeuvre are reduced but not abolished. Failure of ejaculation in the male is much less common than with drugs that are known to blockade sympathetic adrenergic neurones in the periphery.
Pathology, Aetiology and Pathogenesis of Analgesic Nephropathy*
Authors: Nanra R. S. 
Published: March 2008

Summary: 1. The initial site of damage in analgesic abuse is the renal medulla and the characteristic lesion is renal papillary necrosis. The papillary necrosis appears to be an ischaemic infarct. The cortical lesion of chronic interstitial nephritis is a non‐specific change and secondary to obstruction to tubules in the necrotic medulla.2. Medullary perfusion and the concentration mechanism appear to be important factors in the genesis of renal papillary necrosis.3. Experimental and clinical studies suggest that abuse of compound analgesics containing aspirin, phenacetin and caffeine result in renal papillary necrosis and the clinical syndrome of analgesic nephropathy. In the APC mixture aspirin appears to be the major nephrotoxic agent while phenacetin plays a synergistic but secondary role in the renal nephrotoxicity.
The Significance of Lowered Jejunal Disaccharidase Levels
Authors: Jennings W. , Rowland R. , Hecker R. , Gibson G. E. , Fitchf R. J. , Reid D‐ P‐ 
Published: March 2008

Summary: The significance of lowered jejunal disaccharidase levels. W. Jennings, R. Rowland, R. Hecker, G. E. Gibson, R. J. Fitch and D. P. Reid, Aust. N.Z. J. Med., 1976, 6, pp. 556–560.Disaccharidase estimations on 115 consecutive jejunal biopsies are reported. The patients were divided into four groups:1. Normal jejunal biopsy light microscopy, not milk intolerant, 82 cases.2. Normal jejunal biopsy light microscopy, milk intolerant, eight cases.3. Patients with giardiasis, 11 cases.4. Coeliac disease patients, 14 cases. The lowest disaccharidase levels were found in coeliac disease, with giardiasis cases showing intermediate levels. Poor correlation of lactase levels with milk intolerance was found. Three cases in Group 1 showing lowered lactase levels were given metronidazole and showed remission of clinical symptoms, raising the possibility that they had undiagnosed infections with Giardia lamblia.
Effect on Respiration of Diazepam, Chloropromazine and Haloperidol in Patients with Chronic Airways Obstruction
Authors: Tandon M. K. 
Published: March 2008

Summary: Effect on respiration of diazepam, chloropromazine and haloperidol in patients with chronic airways obstruction. M. K. Tandon, Aust. N.Z. J‐ Med., 1976, 6, pp. 561–565.The effect on respiration of diazepam, haloperidol and chloropromazine in patients with chronic airways obstruction was studied on ten patients by the modified rebreathing method of ventilatory response to carbon‐dioxide. The two parameters of the ventilatory response studied were:(a) the slope expressed as litres/minute/ mmHg C02 and(b) minute ventilation at a computed pCO? 57 mmHg (VE 57).A significant decrease in either of these parameters indicated respiratory depression. Following administration of 10 mg diazepam intramuscularly to ten patients a significant depression of respiration was observed in five patients. Administration of 50 mg chloropromazine intramuscularly to eight patients significantly depressed respiration of three patients. A significant depression of respiration was not observed in any of the ten patients given 5 mg haloperidol intramuscularly. These results indicate that the lack of significant respiratory depression from an intramuscular injection of 5 mg of haloperidol to patients with severe chronic airways obstruct/on makes it a safer drug, for the management of acute psychotic episodes in such patients, than 50 mg of chloropromazine or 10 mg of diazepam given intramuscularly.
The Haemolytic Uraemic Syndrome and Oral Contraceptives
Authors: Jackson B. , Clarkson A. R. , Seymour A. E. 
Published: March 2008

Summary: The Haemolytic uraemic syndrome and oral contraceptives. B. Jackson, A. R. Clarkson and A. E. Seymour, Aust. N.Z. J. Med., 1976, 6, pp.580–582.A case of haemolytic uraemic syndrome is described in a young woman in whom the illness was apparently precipitated by the change from a low to a high oestrogen containing oral contraceptive agent.
The Role of Immune Complexes in the Pathogenesis of Disease
Authors: Andrews B. S. , Penny R. 
Published: March 2008

Summary: The role of immune complexes in the pathogenesis of disease. B. S. Andrews and R. Penny, Aust. N.Z. J. Med., 1976, 6, pp. 591–602.Circulating antigen‐antibody complexes are incriminated in the pathogenesis of autoimmune and inflammatory disease, and more recently malignancy.Extensive knowledge of the immuno‐pathological reactions has evolved from the study of experimental serum sickness in animals and of the potential aetiological agents (e.g. viruses) from spontaneous immune complex diseases in animals.Numerous techniques, both direct and indirect, have now been described to identify immune complexes in serum, though no single technique will identify regularly immune complexes in all clinical situations, nor will it demonstrate the pathogenicity of the immune complex in a given patient.Human disorders with a definite immune complex basis (glomerulonephritis, systemic lupus erythematosus, rheumatoid arthritis) and others with a possible immune complex basis (e.g. cutaneous vasculitis) are presented.Management of immune complex disorders is based on removal of the initiating agent if known (e.g. infection, drug, malignancy) or the use of non‐specific antiinflammatory therapy. Specific immunotherapy, in practice and theory, is discussed.
Cholesterol and Phospholipid: Influence of Body Weight on the Output of Lipids in Mesenteric Lymph
Authors: Tall A. R. , Mistilis S. P. , Shields R. J. 
Published: March 2008

Summary: In ageing humans there is accumulation of cholesterol in adipose tissue, muscle and other organs. In human obesity increased synthesis of cholesterol has been demonstrated.In order to ascertain possible endogenous sources of lipids, the output of cholesterol, phospholipid and triglyceride from the bile and small intestine was studied in rats in relationship to body weight.The output of lipid in mesenteric lymph showed an a/most two‐fold increase in the heaviest rats. Small intestinal concentrations of phospholipid and unesterified cholesterol rose significantly with increase of body weight. Output of cholesterol and phospholipid in bile was found to be related to body weight and total bile salt output.The increased lipid content of mesenteric lymph may reflect lipid synthesis in the small intestine, as well as increased absorption from biliary sources, and contribute to cholesterol accumulation in obese rats.Although there are major differences between human and rat cholesterol metabolism, the intestine is a major source of endogenous cholesterol in both species, and could be part of the source of the* additional cholesterol load in obese humans.
Hormonal Profile, Blood Sugar Control and HLA Patterns in Long‐term Insulin Dependent Diabetes with and without Vascular Disease
Authors: Larkins R. G. , Martini F. I. R. , Heding L. G. , Tait B. D. 
Published: March 2008

Summary: Hormonal profile, blood sugar control and HLA patterns in long‐term insulin dependent diabetes with and without vascular disease. R. G. Larkins, F. I. R. Martin, L. G. Heding and B. D. Tait, Aust. N.Z. J. Med., 1978, 8, pp. 465–471.Nineteen insulin dependent diabetics with onset at 30 years of age or less and duration of diabetes of greater than 25 years were divided into two groups on the basis of the presence or absence of clinically evident vascular disease. The patients without vascular disease were characterised by a later mean age of onset, lower fasting growth hormone concentration, and a lower frequency of the unusual HLA pattern B8 without A1 compared to the diabetics with vascular complications. The level of blood glucose control assessed over the last 15 years, insulin antibody titres, plasma glucagon levels and plasma cholesterol did not differ between the two groups. Residual beta cell activity was found in only one of the 19 patients.Although this study does not exclude an effect of the degree of blood glucose control or persistence of beta cell function in the early stages of diabetes on the subsequent development of vascular disease, it suggests that genetic factors, age of onset and plasma growth hormone levels may be more important.
Sudden Death in Auckland
Authors: Fraser G. E. 
Published: March 2008

Summary: Sudden death in Auckland. G. E Fraser, Aust. N Z. J. Med., 1978, 8, pp 490–499.A representative sample of all sudden cardiac deaths occurring in Auckland in one year is reported. Data describing demographic variables, personal characteristics and habits, previous symptoms, prodromal symptoms, the acute phase and post mortem results, is presented. Incidence values are very close to those of other similar communities. The syndrome of “sudden death” probably defines a heterogenous group of cases. Deaths were significantly more common in the cooler months, and in the lowest social class. Some evidence is presented consistent with the hypothesis that a high alcohol intake is associated with sudden death. No differences were found between cases dying within five minutes and those dying later but within 24 hours, considering several variables. Myocardial fibrosis at post mortem was a common finding. The role of the coronary ambulance is briefly discussed.
Iatrogenic Fluorosis
Authors: Grennar D. M. , Palmer D. G. , Malthus R. S. , Matangi M. F. , de Silva R. T. D. 
Published: March 2008

Summary: Iatrogenic fluorosis. D. M. Grennan, D. G. Palmer, R. S. Malthus, M. F. Matangi and R. T. D. de Silva, Aust. N.Z. J. Med., 1978, 8, pp. 528–531.A 69‐year‐old spinster presented with a history of generalised bone pains in September 1977. She was asthmatic and had been treated with 60 mg sodium fluoride and three Calcium Sandoz tablets daily for three years in an attempt to minimize steroid‐induced osteoporosis. She was subsequently found to have fluorosis as shown by radiological osteosclerosis in vertebrae and pelvis with histological. changes of osteomalacia on bone biopsy and a high bone fluoride content. A trial regimen for osteoporosis which is currently being assessed in various centres includes fluoride along with supplementary calcium and Vit D to prevent the production of osteomalacia which may occur with the fluoride salt alone. The case described here emphasises the potential toxicity of therapeutic dosages of fluoride when prescribed with calcium alone and emphasises the need for careful clinical and biochemical monitoring in all patients receiving therapeutic dosages of fluoride.
Effect of Surgical Stress on Serum Thyroid Hormones in Hyperthyroidism
Authors: Engler D. , Donaldson E. B. , Stockigt J. R. 
Published: March 2008

Summary: Effect of surgical stress on serum thyroid hormones in hyperthyroidism.The effect of elective non‐thyroidal surgery on serum total and free triiodothyronine (T3), reverse T3 and thyroxine (TJ has been studied in one patient with mild, untreated typical hyperthyroidism, one with mild T3 toxicosis and in four euthyroid patients. The high T3 level of typical hyperthyroidism became normal post‐operatively, decreasing to 47% of the mean pre‐operative level 24 hours after surgery, while total reverse T3 doubled. In euthyroid subjects T3 decreased to 57 ± 6 (SEM)% of the preoperative level 24 hours after surgery, associated with a doubling of reverse T3. The patient with T3 toxicosis, whose surgical stress was less severe, showed a 17% decrease in T3 without change in reverse T3. Because the inverse post‐operative changes in T3 and reverse T3 described in euthyroid subjects also occur in typical hyperthyroidism, measurement of serum T3 may be diag‐nostically unreliable after surgical stress.
Radionuclide Imaging to Assess Myocardial Damage during Open Heart Surgery
Authors: Kelly D. T. , Harris P. J. , Bautovichi G. , McLaughlin A. , Crocker E. , Baird D. K. 
Published: March 2008

Summary: Radionuclide imaging to assess myocardial damage during open heart surgery.Technetium 99m Pyrophosphate imaging before and after open heart surgery was performed in 38 patients to estimate the incidence of peri‐operative infarction. Positive images were present pre‐operatively in 11 of 30 patients with coronary artery disease. In three patients the images changed from negative to positive and in two this was thought to be due to infarction produced at operation. The high incidence of positive pre‐operative images emphasises that many patients with evolving myocardial infarction, unstable angina or severe heart failure are now operated upon without delay. Because many patients have positive images before surgery pre‐operative and post‐operative images must be compared to assess myocardial damage due to surgery.
Testicular Damage Due to Cytotoxic Drugs and Recovery after Cessation of Therapy
Authors: Roeser H. P. , Stocks A. E. , Smith A. J. 
Published: March 2008

Summary: Testicular damage due to cytotoxic drugs and recovery after cessation of therapy.Testicular function was assessed in 32 patients who received standard chemotherapy regimens for disseminated lymphomas. Thirty‐one had evidence of germ cell damage, as assessed by the finding of azoospermia and/or high plasma levels of follicle‐stimulating hormone (FSH). In addition, five patients had persistently low plasma testosterone levels associated in three with elevated plasma luteinising hormone (LH) levels.Reproductive function did not recover in any patient while chemotherapy continued. Cessation of therapy was possible in 16 patients with prolonged remissions of disease. Among these, recovery of germinal epithelium differed greatly between the cyclophosphamide / vincristine / prednisone treated group and the mustine I procarbazine / vincristine/prednisone treated group. Seventy per cent of the former patients had evidence of recovery after 34 months of follow‐up while only one (17%) of the latter had begun to recover at 52 months post‐therapy. Serial measurement of plasma FSH levels proved useful in predicting likely recovery of spermatogenesis.
A Quantitative Review of the Performance of Implanted Cardiac Pacemakers, Medtronic Model No. 5944
Authors: Thompson G. H. , Black J. L. , Collins D. W. K. 
Published: March 2008

Summary: A quantitative review of the performance of implanted cardiac pacemakers, Medtronic Model No. 5944.One of the service functions of the Sir Charles Gairdner Hospital Department of Biophysics since 1972 has been the routine performance testing of pacemakers implanted by the Hospital's Cardiologists. This service was set up to measure pacemaker pulse parameters with a view to detecting battery depletion. It was also found to be of great help in showing lead insulation deterioration, intermittent capture and movement of the catheter tip within the right ventricle, information that is frequently of help to the Cardiologists in planning acute or elective pacemaker replacement.