Positron Emission Tomography and Autoradiography of (18)F-Fluorodeoxyglucose Labeled Islets With or Without Warm Ischemic Stress in Portal Transplanted Rats

OBJECTIVE

The use of positron-emission tomography (PET) with (18)F-fluorodeoxyglucose (FDG) -labeled islets has been considered to be a potential modality to visualize and quantify early engraftment of islet transplantation. The objective of this study was to evaluate the early islets' survival of the FDG-labeled islets with or without warm ischemic stress in portal transplanted rats using PET and autoradiography.

METHODS

Islets were isolated from Lewis rat pancreata with or without 30-minute warm ischemia times (WITs). For islets' labeling, 300 islets were incubated with 3 MBq FDG for 60 minutes. FDG-labeled islets were transplanted into the liver via portal vein. In in vivo study, a PET study was scanned for 90 minutes and the FDG uptake was expressed as percentage of liver injection dose (ID). In ex vivo study, the liver was exposed for 30 minutes with single fluorescence autoradiography.

RESULTS

In the PET study, the percentage of liver ID of the islets without WIT was 27.8 and that of the WIT islets was 20.1 at the end of islet transplantation. At 90 minutes after transplantation, the percentage of liver ID was decreased to 14.7 in the islets without WIT and 10.1 in the WIT islets. In the autoradiogram, the number of hot spots was more obviously visualized in the liver transplanted without WIT islets than in the liver transplanted with WIT islets.

CONCLUSION

Almost 50% of the islets were immediately lost in both the islets without WIT and those with WIT transplantation in the early period. However, islet survival was 1.4 times higher in the islets without WIT than that in those with WIT in the early engraftment phase.

An Acute Mercuric Mercury Poisoning: Chemical Speciation of Hair Mercury Shows a Peak of Inorganic Mercury Value

A woman ingested a dose of sublimate (approximately 0.9 g) in an attempted suicide. She survived and recovered in response to a combination of therapies including chelate (BAL) therapy, plasma exchange, haemodialysis and peritoneal dialysis.

Serum inorganic mercury concentration, urinary inorganic mercury excretion and hair inorganic and organic mercury and selenium concentrations, along the length from the scalp to the distal part, were measured. Longitudinal analysis of hair, revealed a peak in inorganic mercury corresponding to the time of mercury ingestion. Organic mercury and selenium in the hair had different patterns of longitudinal variation from that of inorganic mercury. The biological half-life (23.5 d) of serum inorganic mercury levels was in good agreement with values previously reported in the literature.

Evaluation of insulin independence using 11C-methionine positron emission tomography after living-donor and brain-dead donor pancreas transplantation

We recently reported that (11)C-methionine positron-emission tomography (PET) is clinically useful for the evaluation of the pancreatic function of the living donor. The objective of this study was to evaluate the postoperative insulin independence in 10 living donor (LD) and 10 brain-dead donor (BD) pancreas transplantations for 20 patients with type I diabetes mellitus by using (11)C-methionine PET. After 6 months, PET/computed tomography was performed 30 minutes after (11)C-methionine (370-740 MBq) injection. The uptake in the pancreas was expressed as the standardized uptake value (SUV). Patient survival rates were 100% at 5 years for LD transplantations and at 2 years for BD transplantations. Insulin independence was 60% for LD transplantations at 5 years and 75% for BD transplantations at 2 years. There were no major surgical complications such as vascular thrombosis, intra-abdominal abscess, and graft pancreatitis. The SUVs for LD and BD pancreas transplantations with insulin independence were 7.2 ± 1.8 and 10.4 ± 2.3, respectively. The SUVs for LD pancreas transplantations with insulin dependence and BD pancreas transplantations with graft failure were 3.6 ± 1.1 and 2.9 ± 1.0, respectively. At 5 years after transplantation, for the LD transplants, the insulin-independent rate was 100% for the graft recipients with an SUV higher than 5, and the median insulin independence duration of the graft recipients with an SUV less than 5 was 7 months (P < .01). The (11)C-methionine PET may be a potent modality to predict long-term insulin independence and the avoidance of pancreas graft failure.

Effects of changes in obesity and exercise on the development of diabetes and return to normal fasting plasma glucose levels at one-year follow-up in middle-aged subjects with impaired fasting glucose

OBJECTIVES

Borderline diabetes, a precursory condition of diabetes, is an important issue in the prevention of diabetes. The aim of the present study was to clarify the effects of one-year changes in obesity and exercise on the development of diabetes or return to normal fasting plasma glucose (FPG) levels among middle-aged people with impaired fasting glucose (IFG) at baseline.

METHODS

Among those who attended a basic health examination in 1997, we selected 1,620 subjects who showed impaired fasting glucose (FPG of 110 mg/dl or higher) and had complete data on height, weight and exercise. At the one-year follow-up (in 1998), 1,099 of those subjects attended a health examination; FPG, height, weight and exercise were evaluated for 731 subjects. Subjects were classified into the following three groups, on the basis of changes in FPG during the year between the two examinations: developing diabetes (DM), remaining IFG, and returning to normal (WNL).

RESULTS

Among those who were initially obese, there was a significant difference in the proportions of DM, IFG and WNL between those with and without improvement in obesity in the year preceding the follow-up (p<0.05). Those with improvement in obesity showed a significantly higher tendency to return to WNL than those without improvement in obesity. Multiple logistic regression analysis showed that those with improvement in obesity had a significantly higher odds ratio (2.17) to return to WNL (p=0.015). Among those who were initially not obese, there was no significant association between changes in obesity and developing DM or returning to WNL. No significant association was observed between changes in exercise and developing DM or returning to WNL.

CONCLUSION

The present findings suggest that, among obese IFG subjects, improvement in obesity is associated with returning to normal plasma glucose. Weight control may be important for the normalization of borderline diabetes.