Vector analysis in partitioning of inspiratory muscle action in dogs.

We considered the displacements and the pressure changes resulting from isolated contraction of 2 muscles as analogous to 2 vectors and those during simultaneous contraction as resultants. These were resolved into contributing components to calculate the contribution of each muscle group and partition the action of inspiratory muscles. Relative displacements of rib cage (delta RC) and abdomen (delta AB) and changes in transpulmonary (delta PL) and abdominal (delta Pab) pressures were obtained during spontaneous breathing, isolated contraction of rib cage muscle (RCM), diaphragmatic (DI), costal and crural diaphragm and passive inflation in 7 dogs. The diaphragm accounted for 58 +/- 19.8% SD of the chest wall displacement and 90 +/- 6.6% SD of the pressure swings during spontaneous breathing. The costal diaphragm accounted for 61 +/- 28.9% SD of the displacement produced by contraction of the entire diaphragm. Despite wide variability in the action of the diaphragm and its components, all animals breathed close to their relaxation characteristic. We conclude that there are marked differences in the degree of RCM recruitment between dogs in order to prevent chest wall distortions.     

Autosomal recessive epidermolysis bullosa simplex. A case report

Summary We report a male child with autosomal recessive epidermolysis bullosa simplex presenting at birth. The patient subsequently developed cutaneous atrophy, nail dystrophy, milia and alopecia. He had growth retardation and anaemia, but there were no other associated abnormalities. Electron microscopy showed epidermolytic cleavage. The family history indicated an autosomal recessive mode of inheritance.     

Hypericin: A New Laser Phototargeting Agent for Human Cancer Cells

Laser activation of anthracycline-related drugs combines chemotherapy with photoablation for improved treatment. Hypericin, a structurally related anthraquinone, was tested for laser activation and cytotoxicity in human cancer cells. Viability of P3 squamous cell carcinoma cells incubated with 1 to 20μg/mL hypericin was reduced by more than 95% after 1 minute exposure at 4°C to an argon laser (514 nm, 5 W), a KTP-532 laser (532 nm, 5 W), or a 20-A xenon lamp. Viability was reduced over 90% in six human carcinoma, sarcoma, and melanoma cell lines by this combined treatment, but only trace toxicity was seen after separate exposure to hypericin or light alone. These results show that hypericin is a sensitive agent for phototherapy of human cancer cells in vitro and indicate that this drug may be useful for tumor targeting via minimally invasive imaging-guided laser fiberoptics.