Microalbuminuria: a marker to increased renal and cardiovascular risk in diabetes mellitus

The presence of persistent microalbuminuria in IDDM is strongly predictive of the future development of end stage renal failure and of cardiovascular disease to a lesser extent. Screening for microalbuminuria is an essential component of modern diabetes practice, as effective antihypertensive therapy, and particularly, the use of angiotensin converting enzyme inhibitors is of proven benefit in retarding progression of renal disease. Cost benefit analysis justifies the expense of microalbuminuria screening programmes and early intervention. It has been estimated that the use of angiotensin converting enzyme inhibitors in microalbuminuric IDDM will save 5200 Pounds-11,000 Pounds per year of life saved. Angiotensin converting enzyme inhibitors are not free of side-effects, and it is therefore essential, given the intrinsic variability of the albumin excretion rate, and the regression to normoalbuminuria of a significant proportion of patients, to confirm the diagnosis of microalbuminuria by repeated measurements prior to the commencement of treatment. The value of intensive glycaemic control is unproven, and further prospective studies are required. There are no proven therapies for the prevention of macrovascular disease in IDDM, although the value of cessation of smoking and aggressive blood pressure control are undoubted in the non-diabetic population. Controversy persists about the value of lipid lowering therapy, especially in young patients, although even in this group there is an increased risk of cardiovascular disease. Microalbuminuria is the strongest known predictor of cardiovascular disease in NIDDM; in contrast to the situation in the non-diabetic population, active lipid lowering therapy is not of proven cardiac benefit, but intervention seems justifiable when taken in the context of the very high prevalence of cardiovascular disease. Microalbuminuria is also predictive of end stage renal disease in NIDDM. Although intervention with angiotensin converting enzyme inhibitors has not been proven to prevent end stage renal disease, stabilisation of albumin excretion rate and creatinine clearance have been demonstrated in normotensive NIDDM, and it seems likely that longer term follow-up studies will confirm the benefit of angiotensin converting enzyme inhibitors in the prevention of end-stage renal disease. The observed predictive power of microalbuminuria as regards both cardiac and renal risk in NIDDM when considered in conjunction with the preliminary results of the benefits of angiotensin converting enzyme inhibition lend further support to the employment of microalbuminuria screening in NIDDM.     

Spot and Aspirated Laser Smoke Detection in Telecommunications Facilities

Full-scale, in-situ comparison tests of spot and aspirated laser detection systems in an active telephone switch center were conducted to compare the response times of spot and aspirated smoke detection systems when exposed to a variety of smoke sources and ventilation conditions. The report documents the performance of multiple systems varying in detector type, detector spacing and detector locations (i.e., mounted on the ceiling versus on return air grills). The work provides data intended to guide system designers in the selection and use of very early warning smoke detection systems.     

Cosleeping (bedsharing) among infants and toddlers

This study was designed to investigate the effect of retaining coronal tooth substance on the performance of post-retained core materials, and to compare the fracture resistance of the system with an intact tooth prepared to similar dimensions. Ten teeth restored with post-retained silver amalgam, and 10 teeth restored with silver-glass cermet, all with a retained single wall of coronal tooth substance, were compared with 10 unrestored teeth prepared to similar dimensions when subjected to a shearing load. The results showed no statistically significant difference between the unrestored teeth and those restored with a silver-glass cermet. Whilst the teeth restored with silver amalgam had a significantly higher fracture resistance (P > 0.01) there was greater tendency to root fracture.     

Long-term potentiation in vivo in layers II/III of rat barrel cortex

Long-term potentiation was studied in vivo in the rat barrel cortex. It was found that LTP lasting several hours could be induced in layer II/III by tetanic stimuli applied in layer IV. The probability of inducing LTP at a given site was high (86%) provided that the electrodes were not displaced too far horizontally. LTP was not observed if the stimulating electrode was located on the far side of the neighbouring barrel-column from the recording electrode. The strongest LTP was induced by stimulating layer IV septal locations or the edge of the barrel and recording in the near half of the neighbouring barrel. However, examples were found of LTP from layer IV to II/III within the same barrel, within the same septum and from barrel to adjacent septum. The probability of inducing LTP on a particular occasion was greatly increased by iontophoresis of bicuculline at the recording site during the tetanus (from 20 to 55% judged by a change in peak amplitude). The average increase in the peak amplitude was 29 +/- 3.2% for protocol 1 (urethane anesthesia, monopolar stimulation) and 23 +/- 7% for protocol 2 (barbiturate anesthesia, bipolar stimulation). The probability of inducing LTP was greater if the first tetanus was accompanied by BMI application (67%) than for any subsequent attempts (39%). These results suggest it should be possible to study the effect of LTP on sensory processing in defined positions within the barrel field.     

Experiments on the small-strain behaviour of crosslinked natural rubber: 2. Extension and compression

Experiments were carried out to characterize the small-strain tension and compression behaviour of dicumyl peroxide crosslinked natural rubber. Strains that were smaller by an order of magnitude than any reported previously on natural rubber were achieved. Our results support the contention that the compression and extension moduli of natural rubber are different. A new finding is reported: that is, the moduli in tension and compression do not become constant but rather they increase significantly as zero deformation is approached.     

Pathogenesis of wild-type and leaderless foot-and-mouth disease virus in cattle

Four calves were experimentally infected via aerosol with foot-and-mouth disease virus. Two were infected with a wild-type virus derived from a full-length infectious clone (A12-IC), and two were infected with a clone-derived virus lacking the leader gene (A12-LLV2), with euthanasia and tissue collection at 24 and 72 h postexposure (hpe). Clinical disease was apparent only in the animal given A12-IC and euthanized at 72 hpe. In situ hybridization revealed that the animal infected with A12-IC and euthanized at 24 hpe had abundant viral nucleic acid in the lung, present in clusters of positive cells in the respiratory bronchiolar epithelium and associated subepithelial regions. At 72 hpe in the A12-IC-infected calf, viral nucleic acid in the lung was present in interstitial areas, and in addition, viral nucleic acid was detectable in epithelial tissues around histologically apparent vesicles. In animals infected with A12-LLV2, viral nucleic acid was detectable in the lung at both 24 and 72 hpe, but staining revealed a more localized distribution with less nucleic acid than was found in animals given A12-IC. Therefore, it appears that after aerosol exposure to A12-IC, early replication is in the region of the lung, with subsequent dissemination to distal sites. In comparison, the A12-LLV2 virus is much less widely disseminated in the lung at 24 hpe, with no lesions or virus detectable in secondary sites at 72 hpe. The greatly reduced pathogenicity of A12-LLV2 may make it an excellent candidate for a modified live viral vaccine.     

Absorption of safflower oil and structured lipid preparations in patients with cystic fibrosis

Patients with cystic fibrosis (CF) and pancreatic insufficiency usually have decreased linoleic and increased oleic, palmitoleic and eicosatrienoic (20∶3ω9) acids compared to normal values of blood and tissue lipids. These changes are consistent with early essential fatty acid deficiency and are observed despite the regular use of exogenous pancreatic enzyme supplementation. As part of a study to determine the relative role of malabsorption as the etiology for the altered fatty acid status, the change in total plasma fatty acids and in area percent of plasma linoleic acid was determined in CF patients and control subjects following the ingestion of various lipid supplements, including two safflower oil preparations and two structured lipid preparations. Fasting subjects consumed 33 g of lipid in a milkshake containing 15 g of protein and 45 g of carbohydrate. Plasma samples obtained 0, 2, 4, 6 and 8 hr after the meal showed that the CF patients absorbed all preparations when administered with their regular dose of pancreatic enzyme supplement. Comparison of the patterns of increase for total plasma fatty acids and area percent of plasma linoleic acid following the administration of the different lipid supplements in CF patients and control subjects suggests that(a) malabsorption alone is not the cause of the abnormal fatty acid composition in the lipids of CF patients and that increased caloric intake along with consumption of adequate amounts of linoleic acid should improve the linoleic acid status of CF patients; (b) there may be selectively increased metabolism of certain fatty acids from the ingested lipids in the relatively malnourished CF patient compared to control subjects; and (c) conditions favoring the persistence of nonpancreatic lipases seem also to favor absorption and utilization of the structured lipid preparation containing medium chain length fatty acids and linoleic acid in CF patients compared to control subjects. Presented at the symposium on “Specialty Lipids and Their Biofunctionality”, at the annual meeting of the American Oil Chemists' Society, Philadelphia, May 1985.     

Modeling of transfer phenomena on heterogeneous Ziegler catalysts: Differences between theory and experiment in olefin polymerization (an introduction)

This article begins by briefly reviewing the more important contributions to the area of modeling heat and mass transfer, and particle growth during the polymerization of olefins on Ziegler–Natta catalysts. It is shown that these models are capable of identifying the critical areas involved in heat and mass transfer, and of modeling polymerizations where the observed activity is less than approximately 5,000 g of polymer per gram of catalyst per hour (g/g/h). However, it is not possible to use these models “as-is” to model more modern catalysts whose activity levels can surpass the 50,000 g/g/h mark because they predict prohibitively large concentration gradients inside the growing particles during slurry polymerizations, and temperature gradients outside the particles during polymerization in the gas phase. An analysis of the mass and heat transfer Peclet numbers (Pe) reveals that certain simplifying assumptions may not always be valid. Pe values in the transition range suggest that convection inside the particles during polymerization in the liquid phase may help to explain why observed mass transfer rates are higher than the predicted rates. In an opposite vein, a Pe analysis shows that conductive heat transfer may play an important role at length scales characteristic of those in the early stages of polymerization. A new mechanism for heat transfer at reduced length scales is proposed. © 1995 John Wiley & Sons, Inc.