1 In this study, we investigated the electrophysiological actions of a high molecular weight fraction, predominantly containing two polymeric 1,3-alkylpyridinium salts (poly-APS) of 5.5 and B19 kDa isolated from the marine sponge Reniera sarai. The biological properties of poly-APS are of particular interest because this preparation may be used to deliver macromolecules into the intracellular environment without producing long-term damage to cells. Poly-APS (50 -0.05 mg ml À1 ) was applied to cultured dorsal root ganglion neurones or HEK 293 cells and changes in cell membrane properties were measured using whole-cell patch-clamp recording and fura-2 Ca 2 þ imaging. 2 Poly-APS (50 mg ml À1 ) evoked irreversible depolarisations in membrane potential and reductions in input resistance. However, doses of 5 mg ml À1 and less produced reversible effects on these cell membrane characteristics and on Ca 2 þ permeability. 3 At 0.05 mg ml À1 , poly-APS could evoke robust transient increases in Ca 2 þ permeability without damaging the neurones or subsequently attenuating Ca 2 þ entry through voltage-activated channels. 4 Bathing cells in NaCl-based extracellular medium containing 1.5 mm zinc attenuated the irreversible and reversible effects of poly-APS on membrane properties (membrane potential, input resistance and whole-cell currents). In both DRG neurones and HEK 293 cells, zinc attenuated Ca 2 þ entry evoked by poly-APS. These effects of zinc were only observed if zinc was continually present during poly-APS application. However, zinc failed to attenuate the actions of poly-APS if it was applied after the sponge toxin preparation had evoked changes in membrane properties. 5 In conclusion, the pore-forming preparation poly-APS can have dose-dependent interactions with cell membranes and at low doses these can be reversible. Additionally, the interactions between poly-APS and cell membranes could be attenuated by zinc.

The circadian rhythm of human circulating lipid components was studied under nearnormal tropical conditions in 162 healthy volunteers (103 males and 59 females; 7 to 75 years of age). They followed a diurnal activity from about 06:00 to about 22:00 and nocturnal rest. These volunteers were divided into four groups: Group A (7-20 years), Group B (21-40 years), Group C (41-60 years) and Group D (61-75 years), comprising 42, 60, 35 and 25 participants, respectively. A marked circadian rhythm was demonstrated for each studied variable in each group by population-mean cosinor analysis (almost invariably p \ 0.001). Furthermore, circadian rhythm characteristics were compared among the 4 groups by parameter tests and regressed as a function of age, separately for males and females. A second-order polynomial characterized the MESOR of HDL cholesterol, phospholipids and total lipids, as well as the 24-h amplitude of total cholesterol and phospholipids. The 24-h amplitude of total lipids decreased linearly with age. The 24-h acrophase of the oldest age group (Group D) was advanced in the case of total cholesterol, HDL cholesterol, and total lipids, whereas that of phospholipids was delayed. Mapping the circadian rhythm (an important component of the broader time structure or chronome, which includes a. o., trends with age and extra-circadian components) of lipid components is needed to explore their role in the aging process in health.

CNVM though rare can occur after macular hole surgery, especially in the setting of age-related changes. Injuries to the RPE should be avoided during surgery. We report a case of CNVM after macular hole in which trypan blue was used as a staining agent.

Fuchs' heterochromic iridocyclitis can develop over a period of time in patients with ocular toxoplasmosis.