A technique for the study of microcirculation in living islets, using quartz rod and cinephotomicrography, is presented, together with results of a study of insular microcirculation. With this technique, conditions are standard, results are reproducible and the findings are recorded permanently. The pancreas, bathed constantly in Locke-Ringer's solution at 37"C, is lifted with the spleen from the body, supported on the tip of Knisely's hollow-tipped fused quartz rod, and the lobules are separated gently. Circulation in the transilluminated islets, which are pale yellow, spherical or ovoid bodies with a distinctive vascular pattern, is studied with the biobjective, binocular microscope. For cinephotomicrography, the camera is aligned over one eyepiece of the microscope and the film is exposed at 64 frames per second, using a 750 watt projection bulb as light source. Direct anastomoses of insular and acinar capillaries are not observed. Blood flow in the islets of the anesthetized mouse is rapid and constant, under these conditions of observation. Intravenous epinephrine and ephedrine cause temporary interruption of blood flow in the islets, whereas norepinephrine slows but does not stop the circulation. Pitressin also causes slowing of insular blood flow. Insulin, glucagon, hydrocortisone, glucose, alloxan and diphenylthiocarbazone have no acute effect upon the insular microcirculation. A possible relation between the circulatory effect and the hyperglycemic effect of epinephrine and ephedrine is suggested.

SUMMARYA randomly selected sample of 500 subjects over 60 years old and their relatives were studied using standardized methods for assessment of cognitive impairment. The prevalence of DSM-111-R dementia was 1.8% (95% confidence intervals 0.6-3%), and the majority of cases had a probable diagnosis of Alzheimer's disease. The sensitivity and specificity of the field survey version of the Mini-Mental State Examination (MMSE) for a diagnosis of dementia using a threshold of 21 were 100% and 53% respectively. This was associated with a positive predictive value of dementia, given a low score, of only 3%. A high prevalence of low MMSE scores was found: 23% of men and 50% of women had scores below 21, and there were strong relationships between low scores and age. Strong associations between low MMSE scores and no education were found, and weaker associations with female sex, deafness and poor sight. The MMSE is markedly affected by educational level, which together with its low positive predictive value for dementia in this population makes it a poor screening or research tool. A Behaviour Rating Scale score had a higher specificity leading to fewer false positives, but only achieved a sensitivity of 67%. In populations with low levels of education it is recommended that behavioural disabilities scales should be developed as a means of screening for dementia syndromes.

The source of the new islets during growth and the effect of aging on the number of islets have been studied in Webster Swiss mice. A combination of methods was employed, including microscopy in vivo, enumeration of the total number of islets, radioautography with H-3-thymidine, and conventional histological technics. The total number of islets in normal mice increases with age until about six months, and then becomes stable or decreases slightly. Radioautographs showed that the cells of the islets are in all likelihood derived from migrating ductal or periductal cells residing at the junction between the islet and pancreatic duct and at the periphery of the islet, and that these cells doubtless serve as the progenitor pool for the growth of the islet. The nuclear cycle of the insular cells was also determined by this method. In vivo study revealed that the structural integrity of ducts and of their vascular supply is important for the maintenance of the population of ductal and periductal islets. DIABETES 75:480-91, July, 1966.Regeneration of pancreatic tissue and formation of new islets of Langerhans in adult mammals of various species have been described in a variety of experimental conditions, including partial or complete pancreatectomy, 1 " 7 ligation of the pancreatic duct, 8 ' 9 ligation of the pancreatic arteries, 10 prolonged hyperglycemia produced by intravenous infusion of glucose, 11 protracted glucagon administration, 12 force-feeding of a high carbohydrate diet 13 and the administration of alloxan. 14 " 16 Whether new islets of Langerhans are formed in the resting pancreas of adult mammals under normal conditions is disputed, 7 " 22 and information concerning the formation of islets in aging is scanty.In both the experimental and the normal state, the

Temporary diabetes was produced in mice by the intravenous injection of alloxan, 75 mg. per kilogram of body weight. The beta cells were degranulated within 6 hrs., but changes in microcirculation did not occur until 24 hrs., and did not appear to play arole in initiating damage to the beta cells. The total number of islets was decreased markedly within one week, but cellular proliferation of ducts and islets began as early as two weeks as indicated by in vivo study and radioautography. Improvement in the diabetic state, manifested by lowered blood glucose, coincided with restoration of a number of the islets. Although the total number of islets was not restored completely, the blood glucose values returned to normal, indicating that the new islets were functioning adequately. Replacement of the insular cells occurred solely by budding of new islets from the ducts,and no evidence of acino-insular transformation, or transformation of centro-acinar cellsinto beta cells, was found.

We have investigated the prevalence and factors associated with hypertension in 976 residents of Klong Toey Slum and 909 residents of government apartment houses, aged 30 and above, selected by probability sampling after systematic household surveys with an average response rate of over 80%. Hypertensives were those who had, on at least three measurements, average diastolic blood pressure equal to or above 95 mmHg and/or systolic blood pressure equal to or above 160 mmHg or had blood pressure below 160/95 mmHg but were currently on antihypertensive medication. The prevalence of total hypertensives were found to be 17.3% and 14.0% for residents of slum and government apartment houses respectively. Men and women had more or less equal mean blood pressure and similar prevalence of hypertension. The mean systolic blood pressure increased with age while the mean diastolic blood pressure, after an initial rise with age in lower age groups, tended to level off from the age group 55-64 years upwards. Only one quarter to one third were aware of their illness and less than 15% were receiving treatment. Significant risk factors include age, duration of smoking, duration of alcohol intake, high body mass index, high Cholesterol, high Triglyceride, high Low Density Lipoprotein Cholesterol (LDLC), low High Density Lipoprotein Cholesterol (HDLC), high Total Cholesterol (TC) to High Density Lipoprotein ratio (TC/HDLC), high LDLC to HDLC ratio and diabetes mellitus. The data suggested that hypertension was an important public health problem in low socioeconomic groups in Bangkok. Some of the risk factors were related to an unhealthy lifestyle which should receive due consideration in planning for appropriate control.