Chlorpropamide-induced thrombocytopenia

Thrombocytopenia is a rare complication of chlorpropamide therapy. An immunological mechanism is generally held responsible, but has never previously been proved. In the present case the existence of such a mechanism has been established.     

Measurement of extracellular fluid volume in patients on maintenance hemodialysis

Angiosarcoma of the breast, a rare tumor with very poor prognosis and insidious early manifestations, frequently is far advanced when first detected clinically. The clinical and pathologic changes in two women with primary, unilateral angiosarcoma of the breast are reviewed and the results are compared with 46 cases already published in the literature. Both patients were middle aged with symptoms for approximately 6 months prior to operation. Both frozen section reports were benign and only called malignant on permanent section. Microscopically the tumors were composed of varying sized, tortuous, elongated vascular channels. The operation varied--a modified radical and a simple mastectomy--and both patients are free from disease 4 and 2 years following operation. It is considered that, in view of the proclivity of this tumor for hematogenous metastases, an axillary dissection may not be justified.     

Release of microquantities of cyproterone acetate from subcutaneous silastic capsules: failure to produce an antifertility effect

Plasma testosterone profiles were determined by taking frequent blood samples at intervals from birth to 21 months of age from rams reared in isolation, in an all-male group and in a mixed-sex group. The testosterone pattern was not modified by these different social environments. The ability of the ram to copulate when first exposed to an oestrous ewe, apparently a maturational process, was also independent of social rearing. At birth plasma testosterone levels were detectable but low, they were higher at 10 and 16 weeks of age and showed a marked rise by 26 weeks, coincident with the time of puberty. Depressive effects of season on testosterone profiles occurred during the 2nd year of life but not the 1st year.     

Evidence that RU 24969-induced locomotor activity in C57/B1/6 mice is specifically mediated by the 5-HT1B receptor

1. The behavioural effects of the 5-HT1B receptor agonists, RU 24969 and CGS 12066B, have been investigated in C57/B1/6 mice. 2. RU 24969 (1-30 mg kg-1) produced intense and prolonged hyperlocomotion and other behavioural changes. 3. CGS 12066B caused similar effects, but they were much less pronounced, inconsistent and transient irrespective of whether this drug was given i.p. (1-15 mg kg-1) or i.c.v. (0.2-40 micrograms). However, CGS 12066B (7.5 and 15 mg kg-1) caused a dose-related inhibition of RU 24969 (7.5 mg kg-1)-induced hyperlocomotion indicating that the former is a 5-HT1B partial agonist. 4. RU 24969 (7.5 mg kg-1 i.p.)-induced hyperlocomotion was inhibited by the (-)-, but not (+)-isomers of pindolol (4 mg kg-1) and propranolol (20 mg kg-1) but not by metoprolol (10 mg kg-1) or ICI 118,551 (5 mg kg-1), consistent with an involvement of 5-HT1A or 5-HT1B receptors. 5. The response was not altered by the selective 5-HT1A receptor antagonist, WAY 100135 (5 mg kg-1, s.c.), the 5-HT2A/5-HT2C receptor antagonist, ritanserin (0.1 mg kg-1), the selective 5-HT3 receptor antagonist, ondansetron (1 mg kg-1) or the non-selective 5-HT receptor antagonists methysergide (3 mg kg-1) and metergoline (3 mg kg-1). 6. Although spiroxatrine (0.1 mg kg-1) and ketanserin (1 mg kg-1) inhibited RU 24969-induced hyperlocomotion, these effects were probably due to antagonism of dopamine D2 receptors and alpha 1-adrenoceptors respectively. 7. Taken together, these results indicate that RU 24969-induced hyperlocomotion results specifically from activation of central 5-HTIB receptors.8. Lesioning of 5-HT neurones with 5,7-dihydroxytryptamine (75 microg, i.c.v.) or depletion with pchlorophenylalanine(200 mg kg-1, i.p. for 14 days) had no effect on RU 24969-induced hyperlocomotiondemonstrating that the 5-HTIB receptors involved are postsynaptic and that they do not show super sensitivity.9. The involvement of other monoamine neurotransmitter systems in RU 24969-induced hyperlocomotionwas also examined. The response was inhibited by the al-adrenoceptor antagonist, prazosin(1 mg kg-1), the dopamine DI receptor antagonist, SCH 23390 (0.05 mg kg-1) and the dopamine D2 receptor antagonist, BRL 34778 (0.03 mg kg-1), but not by the M2-adrenoceptor antagonist, idazoxan(1 mg kg-1). Lesioning noradrenergic neurones with N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine(100 mg kg-1) markedly attenuated this behaviour. These results show that the hyperlocomotion is expressed via noradrenergic and dopaminergic neurones acting on alpha 1-adrenoceptors, DI and D2 receptors.10. RU 24969 decreased brain concentrations of 5-hydroxyindoleacetic acid whilst simultaneously increasing 5-HT, consistent with the reduction of 5-HT neuronal activity by activation of 5-HTlA and 5-HTIB autoreceptors. RU 24969 increased brain 3-methoxy-4-hydroxyphenylglycol, but not noradrenaline, concentrations which supports the involvement of noradrenergic neurones in the expression of hyperlocomotion. RU 24969 did not alter dopamine, dihydroxyphenylacetic acid or homovanillic acid concentrations in the nucleus accumbens suggesting that the dopaminergic neurones terminating there are not directly involved.     

A partial matching theory of the mirror effect in immediate probed recognition

A set of experiments on immediate probed recognition of digit triples is reported in which the variables were list length (five, six, seven, or eight triples), the probability that a probe was old (.33, .5, or .67), and whether the digit triples were presented with an auditory component or articulatory suppression. Previous work had suggested that the false alarm (FA) rate in this paradigm was lower when auditory information was available than when it was not; this observation had led to the development of the partial matching theory of immediate probed recognition, according to which FAs could arise not only as a result of unlucky guesses but also when new probes shared a first digit in common with a partially retained target triple. It was argued that partial memory representations were less likely following auditory presentation than following articulatory suppression. Partial matching theory is contrasted with the rational response theory, according to which all FAs are unlucky guesses; partial matching theory gave a better account of the present experimental data than did rational response theory. However, a logical relationship between the two theories was suggested, a consequence of which was that rational response theory could be modified to include partial matching in such a way as to account for mirror effects, not only in unusually difficult immediate probed recognition tasks, but also in the more commonly studied mixed test list paradigm involving words of high or low frequency.