Effects of physiological state, mass change and diet on plasma metabolite profiles in the western sandpiper Calidris mauri.

We used a food restriction/refeeding protocol to put birds through a controlled cycle of mass loss and mass gain to investigate the effects of rate and phase of mass change on plasma metabolite levels in relation to diet. Despite marked differences in fat content of the two diets (18% vs 4%) mean rate of mass loss or mass gain was independent of diet. There was also no effect of diet on plasma levels of any of the four measured metabolite (triglyceride, glycerol, uric acid and beta-OH-butyrate) during mass loss. However, during mass gain birds on the low fat diet had higher plasma levels of triglyceride and uric acid and lower beta-OH-butyrate than birds gaining mass on the high-fat diet. Thus, diet composition can affect plasma metabolite profiles independently of differences in rates of mass change. Nevertheless, certain plasma metabolites were related to variation in rates of mass change across physiological states. Glycerol levels were negatively related to the rate of mass change (independent of diet), and butyrate was negatively related to the rate of mass change on both diets (though the slope of this relationship was diet dependent). Uric acid was positively related to the rate of mass change but only for birds on the low-fat diet. Our study therefore confirms that measurement of plasma metabolites can provide robust information on physiological state (gain, loss) and the rate of mass change (e.g. in free-living birds caught only once) although researchers should be cogniscent of potential confounding effects of diet composition for certain metabolites, both for field studies and for future experimental validations of this technique.

Healthy communities. Our focus for the future.

The autumn of 1994 has arrived. At this same time last year, most political pundits and policy wonks proclaimed that the Congress would surely take action to overhaul the American health care system before this year's November elections. But as 1994 draws to a close, it has become apparent that Washington is unlikely to produce comprehensive reform legislation at any time in the near future. However, while our political system has failed to act in any meaningful way, its inability to chart a course for change has not quelled the movement to reshape our nation's health care system. Despite Congressional inertia, substantial health care reform is taking place both in Michigan and throughout the nation. These reforms are characterized by a central theme: rapid movement away from our historic focus on illness, and toward a more rational focus on health. Our commitment to healthy communities stands as a firm testament to our mission of service and our role as the central core of the health care delivery system. This article will address the various components of that paradigm shift, and highlight some of the outstanding efforts of Michigan hospitals as they partner with their communities to reshape the delivery of health care services.

Photodynamic treatment of transplantable bladder tumors in rodents after pretreatment with chloroaluminum tetrasulfophthalocyanine.

Chloroaluminum tetrasulfophthalocyanine (AlPCS) was used as a photosensitizer for the photodynamic treatment of transplantable N-[4-(5-nitro-2-furyl)-2-thiazolyl] formamide (FANFT) induced urothelial tumors. Two groups of six rats each were injected with AlPCS (three micrograms./gm. body weight) and 24 hours after injection underwent photodynamic treatment with red light (greater than 590 nm., 360 joules/cm.2). Tumors examined four hours (Group I) and 24 hours (Group II) after the completion of phototreatment showed extensive hemorrhagic necrosis. Tumors treated with AlPCS alone showed no changes. In two other groups of six rats each, blood flow to tumors treated with AlPCS alone (Group III) and AlPCS plus light (Group IV) was measured using the radioactive microsphere technique. AlPCS plus light resulted in a significant decrease (p less than .05) in tumor blood flow within 10 minutes of completion of phototreatment while AlPCS alone had no effect on tumor blood flow. These findings are similar to those observed when higher doses (10 micrograms./gm. to 20 micrograms./gm. body weight) of hematophorphyrin derivative (HpD) and light were used for phototreatment of FANFT induced tumors. AlPCS is a stable sulfonated derivative of tetraazotetrabenzoporphyrin which absorbs maximally in the red portion of the visible spectrum, a region with good tissue penetration properties. These studies suggest the AlPCS may be a useful new agent for photodynamic therapy of cancer.