Blur adaptation: clinical and refractive considerations

The human visual system is amenable to a number of adaptive processes; one such process, or collection of processes, is the adaptation to blur. Blur adaptation can be observed as an improvement in vision under degraded conditions, and these changes occur relatively rapidly following exposure to blur. The potential important future directions of this research area and the clinical implications of blur adaptation are discussed.     

Serum ionic fluoride levels in haemodialysis and continuous ambulatory peritoneal dialysis patients

High serum fluoride (F-) in patients with chronic renal failure (CRF) and end-stage renal disease (ESRD) is associated with risk of renal osteodystrophy and other bone changes. This study was done to determine F- in normal healthy controls and patients with ESRD on haemodialysis (HD) or peritoneal dialysis (PD). Seventeen healthy controls (12 males, 5 females) and 39 ESRD patients on dialysis (17 males, 22 females) were recruited in the study in a community with 47.4 +/- 3.28 microM/l (range 44-51 microM/l) of F- content in drinking water. Control subjects showed a mean serum F- concentration of 1.08 +/- 0.350 microM/l. Males in control group showed slightly higher F- levels (1.15 +/- 0.334, range 0.55-1.9 microM/l) than females (0.92 +/- 0.370, range 0.6-1.5 microM/l). Mean serum F- concentration did not correlate significantly with age and sex among control subjects, whereas such correlation was observed in patients with ESRD on dialysis. Mean serum F- concentration was significantly higher in patients on dialysis (2.67 +/- 1.09, range 0.8-5.2 microM/l) than normal controls. When grouped according to sex, the mean serum F- concentration in males (3.05 +/- 1.04, range 1.8-5.2 microM/l) was significantly higher than females (2.38 +/- 1.08, range 0.8-5.2 microM/l). When patients were grouped according to age, it was observed that F- concentration was significantly higher in patients with age groups 21-70 (2.86 +/- 1.05) than those with age group 13-20 years (1.42 +/- 0.531). Thus F- concentration correlated with age and sex, being higher in males and above 20 years. Despite appreciable clearance of F- (39-90%) across the peritoneum, patients on CAPD showed higher serum F- concentration than those on HD (3.1 +/- 1.97 vs 2.5 +/- 1.137 microM/l). Of the total 39 patients on dialysis 39% had their serum F- concentration above 3.0 microM/l, posing the risk of renal osteodystrophy.      

High incidence of oesophageal and gastric cancer in Kashmir in a population with special personal and dietary habits.

Over a three year period (1 July 1986 to 30 June 1989) all newly diagnosed and histologically proved cases of oesophageal and gastric cancer were recorded prospectively. Some 1515 cases of oesophageal cancer (1050 men and 465 women) and 966 cases of gastric cancer (789 men and 177 women) were registered. Seven patients had simultaneous oesophageal and gastric cancer. Age standardised incidence rates for oesophageal cancer were: men 43.6/100,000 per year; women 27.9/100,000 per year. The rates for gastric cancer were: men 36.7/100,000 per year, women 9.9/100,000 per annum. These figures were three to six times higher than those recorded by cancer registries in Banglore, Madras, and Bombay. The incidence rates for oesophageal and gastric cancer in Islamabad (southern district of Kashmir) were 4.1 to 5.4 times higher in men and 1.5 to 2.0 times higher in women than those for Kupwara (northern district of Kashmir). The incidence rates for oesophageal and gastric cancer in Muslims, Hindus, and Sikhs were different. The epidemiology of oesophageal cancer in Kashmir was similar to that found in the 'Asian oesophageal cancer belt'. At the same time Kashmir also had an unprecedented high incidence of gastric cancer. Kashmiries have special personal and dietary habits. Further studies are needed to define the relation between these habits and the occurrence of oesophageal and gastric cancer.     

The CTLA-4 gene region of chromosome 2q33 is linked to, and associated with, type 1 diabetes. Belgian Diabetes Registry

Susceptibility to autoimmune insulin-dependent (type 1) diabetes mellitus is determined by a combination of environmental and genetic factors, which include variation in MHC genes on chromosome 6p21 (IDDM1) and the insulin gene on chromosome 11p15 (IDDM2). However, linkage to IDDM1 and IDDM2 cannot explain the clustering of type 1 diabetes in families, and a role for other genes is inferred. In the present report we describe linkage and association of type 1 diabetes to the CTLA-4 gene (cytotoxic T lymphocyte associated-4) on chromosome 2q33 (designated IDDM12). CTLA-4 is a strong candidate gene for T cell- mediated autoimmune disease because it encodes a T cell receptor that mediates T cell apoptosis and is a vital negative regulator of T cell activation. In addition, we provide supporting evidence that CTLA-4 is associated with susceptibility to Graves' disease, another organ- specific autoimmune disease.      

Serum sialic acid levels in healthy individuals

Serum sialic acid values, estimated by thiobarbituric acid method of Warren as modified by Saifer and Gerstenfeld in 50 normal healthy persons of both sexes are reported. The average values were 68.47 +/- 4.85 mg% and 67.77 +/- 7.87 mg% for males and females respectively and for both sexes the value was 68.12 +/- 6.70 mg%. Age and sex have no influence on sialic acid levels in serum.     

Identification of a Strong Promoter of Bacteriophage MB78 that Lacks Consensus Sequence Around Minus 35 Region and Interacts with Phage Specific Factor

A strong promoter of bacteriophage MB78 does not have minus 35 consensus sequence although it has a TGn motif immediately upstream of minus 10 sequence as well as the AT rich UP element. It is efficiently recognised by the sigma 70 RNA polymerase, however, a phage-specific factor competes with sigma 70 RNA polymerase for binding to this region, the binding of the factor being stronger than that of the polymerase. Contrary to the reports in the literature the polymerase appears not to bind to the UP element whereas the phage-specific factor does. The latter seems to be involved in the regulation of the promoter activity. This revised version was published online in July 2006 with corrections to the Cover Date.