Mental capability of children exposed to lead pollution

'Eleven-plus' school examination scores were obtained for 851 Birmingham children residing since birth in a lead-polluted area and 1642 children residing in two similar but unpolluted areas. It was found that the children in the lead-polluted area actually scored higher on the average than children in the control areas. Within the area of lead contamination, children living closest to the source of pollution did not have significantly lower scores than children living further away. The results indicate that lead pollution of the magnitude reported in this investigation did not have a demonstrable effect on the mental capabilities of children in the affected community.     

Substrate inhibition of beta-lactamases, a method for predicting enzymatic stability of cephalosporins

Selected cephalosporins, including cefamandole, cephaloridine, cephaloglycin, and cefoxitin, were examined for their ability to inhibit the enzymatic activity of and act as substrates for beta-lactamases produced by Enterobacter cloacae and Staphylococcus aureus. Enzyme inhibition was determined by Michaelis-Menten kinetic measurements and by a spot plate assay using a chromogenic substrate (Glaxo compound 87/312). These two methods provide comparable estimates of kinetic parameters. Inhibition of beta-lactamase, as measured by these two methods, was generally found to correlate with resistance to hydrolysis and is proposed as a preliminary method of assessing susceptibility of cephalosporins to beta-lactamase hydrolysis. Four 7-alphaOCH(3), 7-alphaH cephalosporin analogue pairs were also examined. The presence of the 7-alphaOCH(3) substituent invariably resulted in reduced susceptibility to enzymatic hydrolysis, regardless of the other C7 substituent. The 7-alphaOCH(3) compounds were also better inhibitors than were their 7-alphaH analogues, with the exception that 7-alphaOCH(3) compounds having C7 adipic acid substituents were less inhibitory to the S. aureus enzyme than were the corresponding 7-alphaH analogues. Response of these two enzymes to 7-alphaOCH(3) and 7-alphaH cephalosporins suggests that beta-lactamase hydrolysis of these compounds involves attack at the alpha side of the betalactam ring.     

Partial purification of rabbit aorta contracting substance-releasing factor and inhibition of its activity by anti-inflammatory steroids

Rabbit aorta contracting substance-releasing factor (RCS-RF) is found in perfusates from guinea pig lungs during anaphylaxis. It has been identified as a small peptide which releases arachidonic acid from lung tissue, thus generating prostaglandin endoperoxides and tbromboxanes and causing bronchocconstriction. Anti-inflammatory steroids block the release of arachidonate by RCS-RF. In this activity their relative potency is very similar to their relative anti-inflammatory potency, suggesting that the two actions may be related.     

Renal responses of Australian lungfish to vasotocin, angiotensin II, and NaCl infusion

The Australian lungfish (Neoceratodus forsteri) responds to intravenous injections of 0.63 ng/kg or more of arginine vasotocin with increased dorsal aortic blood pressure, inulin clearance, urine flow, and tubular rejection of Na+. Single injections of 1 ng/kg or more of angiotensin II or norepinephrine also increase dorsal aortic pressure but do not cause consistent diuresis and natriuresis, Continuous infusions of angiotensin II or repeated injections of norepinephrine produce sustained hypertension and more modest diuresis and natriuresis than are seen after injections of arginine vasotocin that cause less hypertension. Infusions of isosmolar or hyposmolar NaCl solutions increase blood pressure, inulin clearance, urine flow, and tubular Na+ rejection in a manner resembling the response to argininge vasotocoin injections. These data are consistent with the hypothesis that arginine vasotocin is released in response to volume expansion in lungfishes and that it may act on the kidney as a diuretic and natriuretic hormone. They do not rule out a more direct action of expansion on renal functions.     

Gluten-free pasta production from banana and cassava flours with egg white protein and soy protein addition

Egg white protein and soy protein were incorporated into a banana and cassava flour blend (75:25) to produce gluten-free pasta. The objectives of study were to investigate the effects of the different protein sources on the physico-chemical properties of gluten-free pasta. The levels of protein inclusion were 0%, 5%, 10% and 15% of composite flour (w/w) for each type of protein. Pasta made from 100% durum wheat semolina was used as controls. The protein fortification affected the total starch, resistant starch and protein content of gluten-free pasta compared to semolina pasta. No significant effects of soy/egg white protein addition were found in either insoluble or soluble dietary fibre content. Cooking properties of pasta (optimum cooking time, swelling index, water adsorption index and cooking loss) and texture properties (firmness and extensibility) were affected by the level of protein addition and the type of protein. Results showed the utilisation of 25% cassava flour and protein inclusion have a promising application in gluten-free pasta production.     

25—COMPOSITION TOLERANCES IN THE MANUFACTURE OF TWO-COMPONENT TEXTILE FABRICS PART II: THE CONTROL OF COMPOSITION VARIATION IN TEXTILE MANUFACTURE

Aspects of the manufacturing technology of two-component fabrics are considered in the light of statistical methods developed in Part I. Quite small design errors increase failure rates significantly; the nominal composition should always be based on actual analyses of intermediate and final products.

Many textile fabrics, especially those containing blended staple-fibre yarns, will not conform consistently to a specified tolerance of ±3 percentage units when tested by the analysis of a single sample or garment; a tolerance of ±5 units is technically realistic for well-made fabrics. A ±3-unit tolerance can reasonably be met by a statement of the average composition of a production batch.

It may therefore be concluded that the EEC Directives, in their mandatory specification of composition labelling, sampling, analytical methods, and tolerances, are unrealistic, since their requirements are not industrially achievable by many textile manufactures.