Increased densities of resting and activated microglia in the dentate gyrus follow senile plaque formation in the CA1 subfield of the hippocampus in the triple transgenic model of Alzheimer's disease

Alzheimer's disease (AD) is an irreversible neurodegenerative disease that is characterised by the presence of β-amyloid (Aβ) plaques, neurofibrillary tangles (NFTs) and synaptic loss specifically in brain regions involved in learning and memory such as the neocortex and the hippocampus. Aβ depositions in the form of neuritic plaques trigger activation of microglia that is believed to be a common neuropathological feature of AD brains. As an integral part of the hippocampus, the dentate gyrus (DG) plays an important role in cognitive function. Although post-mortem studies suggest later involvement of the DG into the AD progression, changes in microglia have not been studied in this subfield of the hippocampus. In the present study the numerical density (Nv, #/mm(3)) of both resting (identified by tomato lectin staining) and activated (identified by Mac-1 immunoreactivity) microglia was analysed in the molecular layer (ML) of the DG in the triple transgenic (3xTg-AD) mouse model of AD at different ages (9, 12 and 18 months). The 3xTg-AD mouse model of AD showed a significant increase in the Nv of resting (by 75%) and activated (by 67%) at 18 months of age compared to non-Tg controls. These results indicate a complex microglial remodelling during AD progression.

Effects of low-dose continuous combined hormone replacement therapy on glucose homeostasis and markers of cardiovascular risk in women with type 2 diabetes

BACKGROUND

Low-dose hormone replacement therapy (HRT) has attracted interest for the treatment of postmenopausal symptoms in diabetes because of concerns about increased risk of coronary heart disease (CHD) and stroke with conventional HRT containing conjugated equine oestrogens (CEEs) and medroxyprogesterone acetate (MPA).

OBJECTIVES

We assessed the effects on glucose homeostasis and cardiovascular risk factors of continuous oral 17beta oestradiol (1 mg) and norethisterone (0.5 mg) in postmenopausal women with type 2 diabetes.

DESIGN

Double-blind, randomized placebo-controlled trial.

ASSESSMENTS

Hyperinsulinaemic isoglycaemic clamp and cardiovascular risk factors were assessed before and after 3 months of treatment.

RESULTS

Twenty-eight women completed the study. HRT decreased fasting glucose compared with placebo [-9.4% with HRT vs.+2.3% for placebo, 95% confidence interval (CI) -23.2 to -0.3] and total cholesterol (-13.7 vs.+1.0%, 95% CI -22.4 to -3.1%) No significant effect was seen on metabolic clearance rate of glucose, glycated haemoglobin (HbA1c), triglycerides, high density lipoprotein (HDL)-cholesterol or C-reactive protein (CRP).

CONCLUSIONS

In women with type 2 diabetes, low-dose HRT decreased fasting glucose and total cholesterol without detectable adverse effects on glucose clearance, triglycerides and CRP as reported with conventional HRT.

Symptomatic benefit from eradicating Helicobacter pylori infection in patients with nonulcer dyspepsia

BACKGROUND

The eradication of Helicobacter pylori infection is beneficial in patients with gastric or duodenal ulcers. The value of eradicating the infection in patients with dyspepsia and no evidence of ulcer disease is not known.

METHODS

We performed a randomized, placebo-controlled trial comparing the efficacy of treatment for two weeks with 20 mg of omeprazole orally twice daily, 500 mg of amoxicillin three times daily (with 500 mg of tetracycline three times daily substituted for amoxicillin in patients allergic to penicillin), and 400 mg of metronidazole three times daily (160 patients) with that of omeprazole alone (158 patients) for resolving symptoms of dyspepsia in patients with H. pylori infection but no evidence of ulcer disease on upper gastrointestinal endoscopy. Symptoms were assessed with the Glasgow Dyspepsia Severity Score, with resolution of symptoms defined as a score of 0 or 1 in the preceding six months (maximal score, 20). One year later the patients were assessed to determine the frequency of the resolution of symptoms.

RESULTS

One month after the completion of treatment, 132 of 150 patients (88 percent) in the group assigned to received omeprazole and antibiotics had a negative test for H. pylori, as compared with 7 of 152 (5 percent) in the group assigned to receive omeprazole alone. One year later, dyspepsia had resolved in 33 of 154 patients (21 percent) in the group given omeprazole and antibiotics, as compared with 11 of 154 (7 percent) in the group given omeprazole alone (95 percent confidence interval for the difference, 7 to 22 percent; P<0.001). Among the patients in the group given omeprazole and antibiotics, the symptoms resolved in 26 of the 98 patients (27 percent) who had had symptoms for five years or less, as compared with 7 of the 56 patients (12 percent) who had had symptoms for more than five years (P=0.03).

CONCLUSIONS

In patients with H. pylori infection and nonulcer, or functional, dyspepsia, treatment with omeprazole and antibiotics to eradicate the infection is more likely to resolve symptoms than treatment with omeprazole alone.

Application of a gamma extremity monitoring system in a radiopharmaceutical dispensary

A new gamma extremity monitoring system (GEMS) was used to assess finger doses of staff working in a hospital radionuclide dispensary. The system is designed to give a continuous readout of dose rate from a small probe which may be attached to a finger. It allows the contributions to radiation dose to the fingers from different parts of a procedure to be measured for the first time and the detailed pattern of radiation exposure to be determined. The dose reduction benefits of small changes in procedure and the use of syringe shields were easily demonstrated after monitoring staff for a few sessions using GEMS, which would not have been possible using thermoluminescent or other integrating dosemeters. GEMS was calibrated against 99Tc(m), 241Am, 137Cs and 131I. The main disadvantage of the system is that the response of the detector increases significantly at lower radiation energies, with that at 60 keV being approximately 70 times the response at 662 keV. In addition, the response of the current detector is nonlinear and saturates around 7000 counts s(-1), which corresponds to a dose rate of 2200 microGy h(-1) for 99Tc(m). Despite these drawbacks, GEMS can play a significant part in the analysis of finger dose patterns and assist in dose reduction.

Clinical and scintigraphic assessment of the role of endoscopic sphincterotomy in the treatment of sphincter of Oddi dysfunction

Postcholecystectomy pain caused by sphincter of Oddi dysfunction remains a difficult condition to treat. Endoscopic sphincterotomy has been recommended for those patients with confirmed sphincter of Oddi motor abnormalities. We have studied sphincter of Oddi dysfunction patients to evaluate the effects of endoscopic sphincterotomy on both clinical symptoms and previously reported scintigraphic parameters to determine the efficacy of this method of treatment. Nine postcholecystectomy patients (seven women: two men, median age 59 years) with clinical and manometric evidence of sphincter of Oddi dysfunction underwent endoscopic sphincterotomy for persisting biliary type pain. Each patient had scintigraphy before and eight weeks after endoscopic sphincterotomy. The patients symptomatic response was assessed independently at three monthly intervals after endoscopic sphincterotomy. Scintigraphic analysis showed that the TMAX (time in minutes to maximum counts) was significantly reduced from 25.0 (20-36) (median [range]) before endoscopic sphincterotomy to 15.0 (13-25) after endoscopic sphincterotomy (p less than 0.01). Seven of nine (78%) sphincter of Oddi dysfunction patients had significant improvement in their symptoms after a mean follow up period of 12 months (range 6-19) although only six of nine were totally pain free. These results suggest that endoscopic sphincterotomy in manometrically confirmed sphincter of Oddi dysfunction improves bile drainage as measured by quantitative cholescintigraphy and is associated with at least short term symptom relief in the majority of patients.

Quantitative 99mTc-DISIDA scanning and endoscopic biliary manometry in sphincter of Oddi dysfunction

Sphincter of Oddi (SO) dysfunction is a recognised cause of postcholecystectomy pain, but a difficult condition to diagnose, requiring endoscopic biliary manometry (EBM) to confirm sphincter motor abnormalities. We have assessed quantitative cholescintigraphy in 10 postcholecystectomy (PC) patients with clinical and manometric evidence of SO dysfunction, 10 PC patients with non-biliary type abdominal pain and 10 asymptomatic PC volunteers acting as controls to determine its value as a non-invasive screening test. Quantitative 99mTc-DISIDA scans lasted 60 minutes, activity/time curves being created by computer analysis using the entire hepatobiliary system as region-of-interest (ROI). Scintigraphic analysis demonstrated that the time in minutes to maximum counts (Tmax) was significantly increased in the SO dysfunction group compared with the non-biliary pain group and the asymptomatic volunteers (p less than 0.001). The per cent of biliary tracer emptied was also significantly less in the SO dysfunction group than either of the other groups at both 45 minutes (p less than 0.01) and 60 minutes (p less than 0.02). We conclude that quantitative cholescintigraphy may be a valuable non-invasive screening test in clinically suspected SO dysfunction.