The anterior cingulate and a collection of other prefrontal and parietal brain regions are implicated in error processing and cognitive control. The effects of different doses of alcohol on activity within these brain regions during an fMRI task where errors are frequently committed have not been fully explored. This study examined the impact of a placebo [Breath Alcohol Concentration (BrAC) = 0.00%], moderate (BrAC = 0.05%) and high (BrAC = 0.10%) doses of alcohol on brain hemodynamic activity during a functional MRI (fMRI) Go/No-Go task in thirty-eight healthy volunteers. Alcohol increased reaction time and false alarm errors in a dose-dependent manner. FMRI analyses showed alcohol decreased activity in anterior cingulate, lateral prefrontal cortex, insula and parietal lobe regions during false alarm responses to No-Go stimuli. These findings indicate that brain regions implicated in error processing are affected by alcohol and might provide a neural basis for alcohol's effects on behavioral performance.

The study of the pathogenesis of islet amyloidosis and its relationship to the development and progression of type 2 diabetes mellitus has been hampered by the lack of an experimentally inducible animal model. The domestic cat, by virtue of the fact that it is one of the few species that spontaneously develop a form of diabetes mellitus that closely resembles human type 2 diabetes, including the formation of amyloid deposits derived from islet amyloid polypeptide (IAPP), was considered to be an excellent candidate species in which to attempt to develop a nontransgenic animal model for this disease process. To develop the model, 8 healthy domestic cats were given a 50% pancreatectomy, which was followed by treatment with growth hormone and dexamethasone. Once a stable diabetic state was established, cats were randomly assigned to groups treated with either glipizide or insulin at doses appropriate to control hyperglycemia. Cats were maintained on this treatment regimen for 18 months and then euthanized. Based on light microscopic examination of Congo red-stained sections of pancreas, all cats were negative for the presence of islet amyloid at the time of pancreatectomy. At the end of the study all 4 glipizide-treated cats had islet amyloid deposits, whereas only 1 of 4 insulin-treated cats had detectable amyloid. In addition, the glipizide treated cats had threefold higher basal and fivefold higher glucose-stimulated plasma IAPP concentrations than insulin-treated cats, suggesting an association between elevated IAPP secretion and islet amyloidosis. Blood-glycosylated hemoglobin concentrations were not significantly different between the two treatment groups. This study documents for the first time an inducible model of islet amyloidosis in a nontransgenic animal.

Abstract.To further characterize spontaneous diabetes mellitus in cynomolgus macaques (Macaca fascicularis) as a model for human non-insulin-dependent diabetes mellitus (NIDDM), we evaluated the morphologic characteristics of the endocrine pancreas of 4 diabetic and 12 age-matched nondiabetic cynomolgus macaques. In addition, the cDNA-predicted amino acid sequence for islet amyloid polypeptide (IAPP) of this species was determined. Islet amyloid deposits exhibiting typical congophilia and green birefringence were found in 4/4 diabetic animals and in 8/ 12 nondiabetics. Islet amyloid deposits were significantly more extensive in the diabetic macaques ( P = O.OOl), in which they occupied a mean of 60% of the islet area. In contrast, in the nondiabetic group the maximum islet area occupied by amyloid was 24% (group mean = 6.8%), with four animals having no detectable islet amyloid. Amyloid deposits consistently showed immunoreactivity for IAPP but not for insulin. Comparisons between group means for diabetic versus nondiabetic macaques showed significantly greater islet area ( P = 0.01, 85,390 versus 36,540 wm2) and significantly greater islet area fraction ( P = 0.02,0.065 versus 0.032) for the diabetic group. The cDNA-predicted amino acid sequence for cynomolgus IAPP was identical to that previously reported for pig-tail macaques (M. nemestrina) and had 92%, 86%, and 84% amino acid sequence identity with human, domestic cat, and murine IAPPs, respectively. These findings support the use of cynomolgus macaques as an animal model of human NIDDM.Key words: Diabetes mellitus; islet amyloid; islet amyloid polypeptide; macaques.The clinical presentation of spontaneous diabetes mellitus in cynomolgus macaques (Macaca fascicularis) closely resembles that of human non-insulin-dependent diabetes mellitus (NIDDM).29 The similarities include onset of diabetes in the middle to late years of life, obesity, hyperinsulinemia and/or blunted insulin response to intravenous glucose, and a long nonketotic phase during which insulin therapy is not needed. These provocative clinical similarities suggest that spontaneous diabetes mellitus in cynomolgus macaques can serve as an excellent animal model of human NIDDM. However, lesions in the pancreatic islets in this animal model have not been extensively documented.In a preliminary study, we noted extensive amyloid deposits in the pancreatic islets of two diabetic cynomolgus macaques.29 However, the prevalence, derivation, and extent of these deposits in aged nondiabetic and diabetic macaques is not known. By comparison, most (if not all) human patients with NIDDM develop amyloid deposits in their pancreatic islets (islet amyloid)1J0,21332 and concurrently lose a substantial portion of their beta cell mass.27~28~30 Similar pancreatic islet lesions occur in association with age-associated diabetes mellitus in domestic c a t~I~, *~ and in diabetes mellitus in other macaque species.'J1J2 Islet amyloid deposits in human patients with NIDDM and feline age-associated diabetes mellitus are deri...