Cutaneous xanthomatous tumours as an expression of chronic myelomonocytic leukaemia?

Nonspecific cutaneous xanthomas have been reported in a variety of lymphocytic neoplastic processes, but to date only three cases of xanthomatous lesions associated with monocytic leukaemias have been described. We now report a patient with a chronic myelomonocytic leukaemia (CMML) associated with these lesions. The clinical and immunohistochemical features do not correspond to any entity previously described and suggest that xanthomas are a cutaneous expression of the CMML.     

CD69 expression and tumour necrosis factor-α immunoreactivity in the inflammatory cell infiltrate of halo naevi

It has been suggested that the involution of the pigmented lesions of halo naevus (HN) is mediated by an immune response, with the involvement of specific cytotoxic T lymphocytes. To explore further the pathogenesis of HN. skin biopsies from six patients with this condition were obtained and the characteristics of the infiltrating inflammatory ceils were studied by immunostaining techniques. We found that the cell infiltrate of HN is mainly composed by CD8⁺ T lymphocytes that express the activation molecule CD69. Tumour necrosis factor-α (TNF-α) immunoreactivity was detected on the inflammatory cells, a finding that suggests that the infiltrating T cells of HN are actively synthesizing this cytokine. Our results indicate that the infiltrating cells of HN predominantly have an activated cytotoxic phenotype, and suggest that these cells are indeed involved in the regression of the naevomelanocytic naevus of HN.     

Biochemical Pharmacology: Polyamine-mediated Heart Hypertrophy Induced by Clenbuterol in the Mouse

The use of β-agonists as growth-promoting agents in cattle could lead to toxic side-effects in man. One such effect is the accumulation of polyamines which seem to be implicated in muscle and heart hypertrophy. We have studied the induction of cardiac hypertrophy after treatment with clenbuterol and the role of polyamines in this effect. Treatment of mice with repeated doses of clenbuterol, a specific β-adrenergic agonist, resulted in a marked increase in heart muscle weight whereas total body weight did not change significantly. Clenbuterol-linked cardiac hypertrophy could be prevented by coadministration of either the non-specific β-adrenergic antagonist, propranolol, or the irreversible inhibitor of ornithine decarboxylase, α-difluoromethylornithine. The clenbuterol-induced cardiac hypertrophy was associated with a corresponding increase in the level of the polyamines putrescine, spermidine and spermine. These observations are indicative of the role of polyamines in cardiac hypertrophy induced by clenbuterol.     

Prenatal drug exposure and maternal and infant feeding behaviour

OBJECTIVE: To evaluate feeding difficulties and maternal behaviour during a feeding session with 1 month old infants prenatally exposed to cocaine and/or opiates. METHODS: The study is part of the maternal lifestyle study, which recruited 11 811 subjects at four urban hospitals, then followed 1388 from 1 to 36 months of age. Exposure to cocaine and opiates was determined by maternal interview and meconium assay. At the 1 month clinic visit, biological mothers were videotaped while bottle feeding their infants. This sample included 364 exposed to cocaine, 45 exposed to opiates, 31 exposed to both drugs, and 588 matched comparison infants. Mothers were mostly black, high school educated, and on public assistance. Videotapes were coded without knowledge of exposure status for frequency, duration and quality of infant sucking, arousal, feeding problems, and maternal feeding activity and interaction. RESULTS: No cocaine effects were found on infant feeding measures, but cocaine-using mothers were less flexible (6.29 v 6.50), less engaged (5.77 v 6.22), and had shorter feeding sessions (638 v 683 seconds). Opiate exposed infants showed prolonged sucking bursts (29 v 20 seconds), fewer pauses (1.6 v 2.2 per minute), more feeding problems (0.55 v 0.38), and increased arousal (2.59 v 2.39). Their mothers showed increased activity (30 v 22), independent of their infants' feeding problems. CONCLUSIONS: Previous concerns about feeding behaviour in cocaine exposed infants may reflect the quality of the feeding interaction rather than infant feeding problems related to prenatal exposure. However, opiate exposed infants and their mothers both contributed to increased arousal and heightened feeding behaviour.     

Atrial Systole and Ineffective Pacemaker Stimuli

An unusual case of pacemaker failure induced by atrial activity is presented. The pacemaker stimulus was ineffective for ventricular capture not only with low energy output (decreased pulse duration) of the generator, but also with pulse width two to three times the stimulation threshold. The two possible mechanisms of this phenomenon, one electrotonic and the other mechanical, are discussed. This report strongly supports the mechanical hypothesis.