Effects of streptozotocin-induced diabetes mellitus and insulin treatment on neuropeptide Y mRNA in the rat hypothalamus

Summary Levels of neuropeptide Y and neuropeptide Y mRNA are increased in the arcuate nucleus of severely diabetic rats which may be the result of the associated marked hypoinsulinaemia. We hypothesised that if neuropeptide Y mRNA is regulated by physiological changes in circulating insulin, then the relatively minor changes in circulating insulin found in mild diabetes would also affect neuropeptide Y expression and its response to changing insulin levels should be rapid. Neuropeptide Y mRNA was quantified by in situ hybridisation through the rostral, mid and caudal levels of the arcuate nucleus of adult female rats. Neuropeptide Y mRNA was significantly increased at all three levels of the arcuate nucleus, 7 days after i.v. administration of 40 mg/kg streptozotocin. Neuropeptide Y mRNA was not further increased in the arcuate nucleus of animals given 50 mg/kg streptozotocin. In the former group, serum glucose was increased but insulin levels and body weights were the same as in control rats. In the 50 mg/kg streptozotocin group, serum glucose was further increased while serum insulin and body weight were reduced. In addition, neuropeptide Y mRNA was not altered in the hypothalamic dorsomedial nucleus or the thalamic reticular nucleus. When diabetic rats were treated for 20h with s.c. insulin, there was decreased neuropeptide Y mRNA in the arcuate nucleus. We conclude that neuropeptide Y mRNA in the arcuate nucleus is responsive to small changes in circulating insulin levels and the response occurs within 20 h. These data support that circulating insulin may contribute to control of neuropeptide Y expression under physiological conditions. Presented in part at the Ninth International Congress of Endocrinology, 1992 Nice, France     

Neuroimaging findings in Alexander's disease

We present the findings from magnetic resonance imaging, computed tomographic scan, and single photon emission computed tomography of the brain in a 2-year-old girl with Alexander's disease. Computed tomographic scans showed prominent low-density white matter throughout the cerebral hemispheres. Magnetic resonance imaging showed increased T2 signal from the cerebral white matter but not the cerebellum or brain stem. Single photon emission computed tomography revealed diminished cerebral metabolism, particularly in the frontal regions, as compared with the cerebellum.     

Diverticular abscesses: percutaneous drainage

Percutaneous catheter drainage was performed in 16 patients with diverticulitis complicated by abscesses. Each patient had resolution of fever within 72 hours. Eleven patients subsequently underwent simultaneous sigmoid resection and operative anastomosis 10-40 days after percutaneous drainage. One patient required a three-stage procedure after percutaneous drainage, and one patient was too unstable for operation at any time during her course and eventually died of respiratory failure. Three patients did not undergo resection after catheter drainage and have remained asymptomatic for 1-2 1/2 years. Ten of 16 patients had fistulas, eight of which closed spontaneously. Experience with percutaneous drainage of diverticular abscesses suggests that it obviates surgical abscess drainage and permits a single operation (sigmoid resection and closure) to be performed safely. Percutaneous abscess drainage has cost-saving implications, since one or two operations may be avoided in most patients, and in some high-risk elderly patients all operations may be obviated.     

Recurrence of meningiomas after operation

The authors reviewed 53 consecutive patients who underwent surgical removal of a meningioma within a 10-year period. The removal was graded macroscopically as either a total removal (types I-III) or a subtotal removal (type IV). The patients were observed for an average period of 5.3 years, during which time there was a 9.5% recurrence after type I removals and an 18.4% recurrence after type II. There was regrowth in 20% of the subtotal group. There was no correlation with age or sex, but histology was important. Syncytial tumors tended to recur, and mitosis and area of focal necrosis were associated with a tendency towards recurrence. The significant features associated with recurrence are discussed.