Abnormal myocardial repolarisation in response to hypoxaemia and fenoterol.

Background: Prolongation of the QTc interval has been associated with cardiac dysrhythmias and sudden death. QTc dispersion (interlead variability in QTc interval) has recently been proposed as being a more sensitive marker of repolarisation abnormalities and shown to be a more specific index of arrhythmia risk. Although hypoxaemia and fenoterol have previously been shown to prolong the QTc interval, this does not reflect regional myocardial repolarisation abnormalities.

Bronchodilator subsensitivity to salbutamol after twice daily salmeterol in asthmatic patients.

In view of current concerns about use of regular beta-2 agonists, and the place of the newer long-acting drugs, we decided to evaluate whether continuous exposure to twice daily salmeterol results in a blunting of the acute bronchodilator response to repeated doses of salbutamol, as might be administered in the management of an acute asthma attack. After a 2 week run-in without beta-2 agonists, 17 asthmatic patients (mean [SE] age 34 [3] years, mean forced expiratory volume in 1 s [FEV1] 64 [2.7]% of predicted) were randomised to receive salmeterol 50 micrograms twice daily or placebo for 4 weeks in a double-blind cross-over fashion.

Subsensitivity of bronchodilator and systemic beta 2 adrenoceptor responses after regular twice daily treatment with eformoterol dry powder in asthmatic patients.

Background: There is controversy as to the role of long acting beta 2 agonists such as eformoterol and, in particular, whether bronchodilator tolerance occurs during continuous therapy. The purpose of this study was to extend previous observations of bronchodilator subsensitivity with metered dose eformoterol aerosol in order to assess whether tolerance also occurs with a dry powder formulation of the same drug.

Methods: Sixteen asthmatic patients of mean age 33 (range 18-53) years and FEV1 (% predicted) of 64 (3)%, of whom 13 were receiving inhaled corticosteroids, received regular treatment with eformoterol 24 micrograms twice daily or placebo twice daily (without beta 2 agonists) given concurrently for four weeks in a randomised double blind cross-over design.

Tolerance with beta 2-adrenoceptor agonists: time for reappraisal.

1. In spite of the widespread use of beta 2-adrenoceptor agonists in the treatment of asthma controversy continues regarding their possible role in increasing asthma mortality and morbidity. There is however no evidence available to suggest that tolerance to the bronchodilator or anti-bronchoconstrictor effects of these drugs is responsible for the deleterious effects reported with the regular use of bronchodilators.

Expression of the beta 2 adrenoceptor partial agonist/antagonist activity of salbutamol in states of low and high adrenergic tone.

Background: Salbutamol exhibits partial agonist/antagonist activity at airway beta 2 receptors in vitro in that it attenuates the bronchorelaxant effect of the full agonist isoprenaline. The aim of the present study was to characterise the partial beta 2 agonist/antagonist activity of salbutamol in vivo during supine rest and exercise, in states of low and high adrenergic tone.

Methods: Eight normal subjects were randomised to receive single oral doses of salbutamol 2 mg, 4 mg, 8 mg (S2, S4, S8), placebo (PL), or propranolol 80 mg (PR).

A comparison of the effects of prednisolone and mianserin on ventilatory, exercise and psychometric parameters in patients with chronic obstructive pulmonary disease.

There is controversy as to whether effects on mood play a role in mediating the response to corticosteroids in chronic obstructive pulmonary disease (COPD). If alterations in mood are important, it is conceivable that psychotropic drugs such as mianserin might produce similar responses to prednisolone in patients with COPD. Twelve patients age 62.

A comparison of the systemic bioactivity of inhaled budesonide and fluticasone propionate in normal subjects.

1. The aim of this study was to compare the systemic bioactivity of low and high doses of inhaled budesonide and fluticasone propionate given by respective dry powder inhaler devices. 2.

Pharmacological effects of epibatidine optical enantiomers.

The pharmacology of synthetic D- and L-epibatidine, an alkaloid originally characterized from frog skin, were studied in different behavioral tests in mice and rats. The two enantiomers have potent antinociceptive activity in mice using the tail-flick test, with an ED50 of 6.1 and 6.

The value of immunohistochemistry of pleural biopsy specimens in the differential diagnosis between malignant mesothelioma and metastatic carcinoma.

The aim of the present study was to evaluate the aid of immunohistochemistry in the differential diagnosis between pleural malignant mesothelioma (MM) and secondary pleural carcinoma in pleural biopsy specimens. A series of MM (epithelial or biphasic type) (n = 39), and a series of secondary pleural carcinomas (n = 25) were studied with a panel of monoclonal antibodies against Ber-EP4, CEA, and Leu-MI (CD-15). Considering the markers one, two or three at a time, computer analysis was conducted to identify the immunophenotype with the highest sensitivity and specificity for both MM (n = 39) and adenocarcinoma (n = 19).

The magical and medicinal usage of Stangeria eriopus in South Africa.

The underground caudex of the cycad Stangeria eriopus is used extensively by several ethnic groups in South Africa, mainly as an ingredient in magical potions but also as an emetic. An assessment of two main outlets showed that 3410 plants were sold in the month of July 1992; continued usage of this material now threatens the remaining plant populations. A proximate analysis of the caudex material gives high carbohydrate content with only small percentages of fat, protein, fibre and ash.

Chemical synthesis and characterization of peptides and oligomeric proteins designed to form transmembrane ion channels.

A strategy for the synthesis of peptides and oligomeric proteins designed to form transmembrane ion channels is described. A folding motif that exhibits a functional ionic pore encompasses amphipathic alpha-helices organized as a four-helix bundle around a central hydrophilic pore. The channel-forming activity of monomeric amphipathic peptides may be examined after reconstitution in lipid bilayers in which peptides self-assemble into conductive oligomers.

alpha-Amylase in resectable lung cancer.

Biochemical analysis and immunohistochemical techniques support the theory that hyperamylasaemia in lung cancer is due to amylase production in carcinoma cells. The vast majority of amylase-producing carcinomas are adenocarcinomas with amylase isoenzyme similar to the salivary type. This prospective study assesses alpha-amylase expression in resectable lung cancer.

Amylase in lung carcinomas. An ultrastructural and immunohistochemical study of two adenocarcinomas, and a review of the literature.

The ultrastructure of two lung adenocarcinomas with immunohistochemical and biochemical expression of amylase is reported. Isoenzyme determination performed on tumour tissue showed a salivary-type amylase. None of the carcinomas was associated with hyperamylasaemia.

Design of a functional calcium channel protein: inferences about an ion channel-forming motif derived from the primary structure of voltage-gated calcium channels.

To identify sequence-specific motifs associated with the formation of an ionic pore, we systematically evaluated the channel-forming activity of synthetic peptides with sequence of predicted transmembrane segments of the voltage-gated calcium channel. The amino acid sequence of voltage-gated, dihydropyridine (DHP)-sensitive calcium channels suggests the presence in each of four homologous repeats (I-IV) of six segments (S1-S6) predicted to form membrane-spanning, alpha-helical structures. Only peptides representing amphipathic segments S2 or S3 form channels in lipid bilayers.

Primary leptomeningeal T-cell lymphoma: a case and a review of primary T-cell lymphoma of the central nervous system.

A case of primary leptomeningeal T-cell lymphoma of pleomorphic large cell type is presented. The lymphoma, which was first diagnosed at autopsy, occurred in a 67-year-old man, who had no personal or family history of immunodeficiency disorders. Review of the literature reveals only 13 immunocytochemically well-documented cases of primary T-cell lymphoma in the CNS.

Superficial perineal leiomyosarcoma in an adolescent female and a review of the literature including vulvar leiomyosarcomas.

Superficial perineal leiomyosarcomas are rare, with only three previously reported examples. We encountered a superficial (deep subcutaneous) perineal leiomyosarcoma in a 17-year-old female. At follow-up two years after a wide excision, there were no signs of recurrence.

Merkel cell carcinoma of the eyelid and periocular tissues.

Five patients had eyelid and periocular Merkel cell carcinoma. The tumor was located on the left lower eyelid in two patients, the left upper eyelid in one patient, the right upper eyelid in one patient, and was metastatic to the right outer canthus in one patient. The mean duration of symptoms was approximately four months.

Frequency of Helicobacter pylori and gastritis in healthy subjects without gastrointestinal symptoms.

To investigate the frequency of Helicobacter pylori and gastritis in asymptomatic adults, 30 healthy volunteers underwent upper endoscopy. Biopsy specimens were obtained from the corporeal and antral mucosa of the stomach. The specimens were examined by light microscopy for gastritis and the occurrence of H.

Venous engorged tissue flaps treated with medicinal leeches.

We evaluated the ability of leeches to improve the tolerance of pedicle flaps to periods of venous congestion. Axial pedicle flaps were created on 14 rabbit ears; the venous circulation of each flap was compromised with a suture ligature. Medicinal leeches were applied to seven flaps; the other seven flaps were untreated.