Calcium ions play a key role in many aspects of neuronal behavior and certain calcium binding proteins that may influence this behavior are differentially distributed in the central nervous system. In this study it is shown that immunoreactivity for calbindin-28 and for parvalbumin is localized in separate populations of inhibitory GABA interneurons in all areas of the neocortex of Old World monkeys. Virtually all GABA neurons show immunoreactivity for one or other calcium binding protein but, except for a few cells in layer IV, GABA cells do not show immunoreactivity for both proteins. Among the two cell populations, parvalbumin immunoreactivity characterizes basket neurons while calbindin immunoreactivity characterizes double bouquet neurons. These findings suggest that the two GABA cell types differ in their regulation of calcium homeostasis and may yield clues to their different roles in intracortical circuitry.

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Summary. -Discussions of chronic poverty have mostly considered its monetary dimensions, with current evidence suggesting that such poverty is much more transient than chronic. But chronic poverty is a real and important phenomenon, potentially more important quantitatively than it first appears once account is taken of different methodological approaches and inevitable measurement difficulties. The chronic poor have distinctive characteristics, such as lack of assets or high dependency rates, which may account for their persistent poverty. The paper argues that it is also necessary to develop concepts of chronic poverty further, covering relevant nonmonetary dimensions and not just relying on panel data.

221 mmol/l; 68 5+19 8 mg/100 ml) (P<0 001) but not on the test day (maximal increase 1-3 ± 1 1 mmol/l; 23-4 ± 198 mg/100 ml). Throughout the remainder of the study period blood glucose was significantly lower on the test day than on the control day, although after lunch it increased by similar increments on the two days. The average blood glucose value during the eight hours was significantly lower on the test day than on the control day (11-2+1 6 mmol/l (202 0+28-8 mg/100 ml) compared with 14 8±1 2 mmol/l (267 0±21 6 mg/100 ml)) (P<00001). Qualitatively similar effects were seen in each patient studied, regardless of the order of treatment. Although none of the patients had symptoms of hypoglycaemia during the study, in two cases values of 2 8 mmol/l (50 5 mg/100 ml) were recorded towards the end of the test day.Blood lactate concentrations tended to be lower throughout the test day than the control day, significant differences in peak values being recorded after breakfast and lunch (figure). The profile of mean blood pyruvate values was similar to that of lactate values (figure), although none of the differences between values on the control and test days reached significance (P-0 05). No consistent changes were seen in the lactate to pyruvate ratio or in the mean blood concentrations of 3-hydroxybutyrate, glycerol, or alanine. DiscussionOur results show that the ot-glucosidehydrolase inhibitor acarbose may greatly decrease the blood glucose concentration in insulin-treated diabetics, particularly after breakfast. This is presumably due to a reduction in the rate of absorption of glucose from the intestinal tract, although we cannot say whether this in turn is due solely to a prolongation of the time taken for carbohydrate to be absorbed or whether there is also a reduction in the total amount absorbed. In normal people the addition of 200 mg acarbose to a 100 g oral load of sucrose causes 40°0 of the sucrose to pass unabsorbed through the small intestine.4 A comparable degree of carbohydrate malabsorption is to be expected in diabetics. The subsequent fermentation of nonabsorbed sugars by colonic bacteria leads to flatulence, which is a common and often unacceptable side effect of acarbose. The effects of the drug on blood lactate and pyruvate concentrations are less readily explained but may be due to a reduction in the rate of supply of glucose to the glycolytic pathway.Other methods of slowing carbohydrate absorption in diabetics include adding the non-absorbable carbohydrate guar gum to food.6 Guar is thought to exert its effect mainly by delaying gastric empyting and thus has a different mode of action from that of acarbose. Acarbose has the important advantage that it may be taken as tablets with ordinary food. It remains to be seen whether a suitable treatment regimen can be devised for its use in the long-term management of insulin-dependent diabetes. Medical3Journal, 1979, 1, 221-223 Summary and conclusions In 110 white West Midlands children serum 25-hydroxy vitamin D (25-OHD) concentrations sho...

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1. A comparison was made of the nature and intestinal intracellular distribution of the metabolites formed in vitamin D-deficient chicks from [4-(14)C]cholecalciferol and [1-(3)H]cholecalciferol. 2. The simultaneous administration of the two radioactive substances showed the presence in blood, liver, intestine, kidney and bone of cholecalciferol, its ester, 25-hydroxycholecalciferol and a further metabolite of cholecalciferol more polar than 25-hydroxycholecalciferol. The (3)H/(14)C ratios in these four radioactive components were the same as that of the dosed material (4.7:1) with the exception of the most polar material. The (3)H/(14)C ratio was lower in the fourth, most polar, metabolite (0.4:1-1.8:1) in all tissues examined, with the exception of blood. 3. In the chick intestine the polar metabolite accounted for almost 70% of the radioactivity in this tissue after a dose of 0.5mug. of [4-(14)C,1-(3)H]cholecalciferol. This polar metabolite from the intestine also had the lowest (3)H/(14)C ratio of all the tissues. It appears that in the chick intestine the polar metabolite reaches a maximum concentration of 1ng./g. of tissue, above which it cannot be increased irrespective of the dose of the vitamin. 4. The intestinal intracellular organelle with the highest concentration of (14)C radioactivity is the nucleus, and this radioactivity is almost entirely due to the polar metabolite with the lowered (3)H/(14)C ratio, in this case <0.2:1. It appears to be further localized in the chromatin of the nuclei. However, about half of the polar metabolite in the intestine is extranuclear. 5. Double-labelled 25-hydroxycholecalciferol was prepared and after its administration to vitamin D-deficient chicks the polar metabolite with the lowered (3)H/(14)C ratio was detected in liver, kidney, intestine, bone, muscle and heart. 6. None of the polar metabolite with the lowered (3)H/(14)C ratio was detected 16hr. after dosing with either the double-labelled vitamin or the double-labelled 25-hydroxycholecalciferol in blood and adipose tissue of vitamin D-deficient chicks, nor in the intestine, liver and kidney of supplemented birds. 7. The reasons for this loss of (3)H relative to (14)C are discussed in relation to possible chemical structures of this new polar metabolite.

Plasma concentrations of 25-hydroxy vitamin D (25-OHD) in winter of 15-0-22-5 nmol/l (6-9 ng/ml) require that the concentration in the previous summer was over 40 nmol/l (16 ng/ml). To maintain plasma concentrations in the elderly above those associated with osteomalacia a mean dietary vitamin D intake of over 5 tg/day is required. A more physiological approach, however, would be to increase exposure to UVL.