ABSTRACT
AIM: Is modulation of skeletal muscle capillary supply by altering blood flow due to a presumptive shear stress response per se, or dependent on the vasodilator mechanism? METHODS: The response to four different vasodilators, and cotreatment with blockers of NO and prostaglandin synthesis, was compared. Femoral artery blood flow was correlated with capillary-to-fibre ratio (C:F) and protein levels of putative angiogenic compounds. RESULTS: All vasodilators induced a similar increase in blood flow after 14 days, with a similar effect on C:F (1.62 ± 0.05, 1.60 ± 0.01, 1.57 ± 0.06, 1.57 ± 0.07, respectively, all P < 0.05 vs. control 1.20 ± 0.01). Concomitant inhibitors revealed differential effects on blood flow and angiogenesis, demonstrating that a similar response may have different signalling origins. The time course of this response with the most commonly used vasodilator, prazosin, showed that blood flow increased from 0.40 mL min-1 to 0.61 mL min-1 by 28 days (P < 0.05), dropped within 1 week after the cessation of treatment (0.54 mL min-1 ; P < 0.05) and returned to control levels by 6 weeks. In parallel with FBF, capillary rarefaction began within 1 week (P < 0.05), giving C:F values similar to control by 2 weeks. Of the dominant signalling pathways, prazosin decreased muscle VEGF, but increased its cognate receptor Flk-1 (both P < 0.01); levels of eNOS varied with blood flow (P < 0.05), and Ang-1 initially increased, while its receptor Tie-2 was unchanged, with only modest changes in the antiangiogenic factor TSP-1. CONCLUSION: Hyperaemia-induced angiogenesis, likely in response to elevated shear stress, is independent of the vasodilator involved, with a rapid induction and quick regression following the stimulus withdrawal.
Subject(s)
Muscle, Skeletal/physiology , Neovascularization, Physiologic/physiology , Stress, Mechanical , Vasodilator Agents/pharmacology , Angiogenesis Inducing Agents/pharmacology , Animals , Blood Pressure/drug effects , Blood Pressure/physiology , Cromakalim/pharmacology , Cyclooxygenase Inhibitors/pharmacology , Enzyme Inhibitors/pharmacology , Ethanol/pharmacology , Heart Rate/drug effects , Heart Rate/physiology , Indomethacin/pharmacology , Male , Mice , Muscle, Skeletal/drug effects , Neovascularization, Physiologic/drug effects , Nitric Oxide Synthase/antagonists & inhibitors , Prazosin/pharmacology , Verapamil/pharmacologyABSTRACT
We report a case of rhinocerebral mucormycosis in a patient with acute lymphoblastic leukaemia undergoing remission induction therapy. The diagnosis was suspected on the characteristic clinical features and confirmed by histology and culture of infected tissue obtained by biopsy. Treatment was successful because of early institution of antifungal therapy, repeated surgical debridement and established of remission in the underlying disease.
Subject(s)
Leukemia, Lymphoid/complications , Mucormycosis/diagnosis , Paranasal Sinus Diseases/diagnosis , Adult , Amphotericin B/therapeutic use , Debridement , Diagnosis, Differential , Female , Humans , Mucormycosis/complications , Mucormycosis/therapy , Paranasal Sinus Diseases/complications , Paranasal Sinus Diseases/therapyABSTRACT
A case of rhabdomyosarcoma of the larynx in a 54-year-old man is reported. Patient presented dramatically with a large tumour mass obstructing his laryngeal inlet. The patient remains alive and well sixteen months after a total laryngectomy. Only seven previous reports of a rhabdomyosarcoma of the larynx could be found in the literature and these are compared with the case reported. It would seem that a rhabdomyosarcoma of the larynx has a better prognosis than elsewhere in the body, probably because of its earlier recognition and accessibility to radical surgery.
