No description available.

The zebrafish (Danio rerio) has been used as a model for studying vertebrate development in the cardiovascular system. In order to monitor heart contraction and cytosolic calcium oscillations, fish were either embedded in methylcellulose or anesthetized with tricaine. Using high-resolution differential interference contrast and calcium imaging microscopy, we here show that dopamine and verapamil alter calcium signaling and muscle contraction in anesthetized zebrafish, but not in embedded zebrafish. In anesthetized fish, dopamine increases the amplitude of cytosolic calcium oscillation with a subsequent increase in heart contraction, whereas verapamil decreases the frequency of calcium oscillation and heart rate. Interestingly, verapamil also increases myocardial contraction. Our data further indicate that verapamil can increase myocardial calcium sensitivity in anesthetized fish. Taken together, our data reinforce in vivo cardiac responses to dopamine and verapamil. Furthermore, effects of dopamine and verapamil on myocardial calcium and contraction are greater in anesthetized than embedded fish. We suggest that while the zebrafish is an excellent model for a cardiovascular imaging study, the cardio-pharmacological profiles are very different between anesthetized and embedded fish.

No description available.

Skin blood flow (SKBF) demonstrates a biphasic response to innocuous, local heating. Much about the mechanism of the first phase is unknown. A type of ion channel (TRPV3) sensitive to and increasingly activated by temperatures from ~33 to ~45°C may be involved. TRPV3 channels are abundantly located in the keratinocytes and are believed to elicit the release of ATP, a putative cutaneous vasodilator, upon activation. This study investigated the possibility that TRPV3 channels and ATP have a role in the first phase of the SBKF response to local heat. Fifteen young, healthy subjects participated in the study. Two microdialysis probes were inserted into the dermis on the forearm. Using a peltier module, the skin above the probes (3cm x 3cm) was heated to 31, 35, 39, and 43°C to manipulate the level of activation of TRPV3 channels for eight minutes each. The probes were perfused with 0.9% saline at 2µl/min. Dialysate from each phase was analyzed for the concentration of ATP ([ATP]d). Cutaneous vascular conductance (CVC), measured by laser Doppler flowmetry, was monitored throughout. The [ATP]d decreased significantly when the skin was heated to temperatures known to strongly activate TRPV3 channels (i.e 39 and 43°C). [ATP]d demonstrated no relationship with CVC and only a very weak relationship with peltier temperature (r2 = 0.02, p<0.05). These data indicate that local heating and presumably heat-induced activation of the TRPV3 channels results in the decrease, not increase, of the release of ATP in human skin, and that the [ATP]d is not related to changes in skin blood flow. Significant dilation was observed at 35°C. This threshold, which is several degrees lower than the threshold previously reported, suggests that the TRPV3 channels may be involved in the dilator response in some way independent of interstitial ATP.

Thesis (M.S.)--Boston University / This study will present one of the methods of treatment for alcoholism, Conditioned Reflex (Response) Therapy, at the Washingtonian Hospital in Boston, Massachusetts, where it is felt that success can be achieved in the treatment of some cases. It may be that this new treatment method is at last on the way to removing the aura of hopelessness, that is, if patients can be selected from the larger alcoholic group who can be considered to have a fairly high probability of success. This Conditioned Reflex treatment group has a high percentage of successes. There are also a certain number of failures. The purpose of this study is to look more closely at the characteristics of both groups of patients, the successes and the failures, to see if the number of successes can be increased by an even more careful selection of candidates for treatment. Before discussing the Conditioned Reflex treatment group, it would seem useful to discuss the larger group from which these patients are chosen and some of the theories of alcoholism.

No description available.

No description available.

No description available.

No description available.

No description available.