The trickle-down theory of cleaner air

The 1990 Clean Air Act Amendments prompted an increased urgency to find new ways to treat airstreams containing volatile organic compounds, which affect the nitrogen photolytic cycle and help produce ground-level ozone, hazardous air pollutants, and odorous air emissions such as hydrogen sulfide. Scientists at the New Jersey company Envirogen have adapted traditional biofiltration technology to perform airborne waste stream cleanup. Preliminary research on pollutants such as phenol, methylene chloride, benzene, and toluene indicates that Envirogen's biotrickling filter may remove an average of about 94% of total hazardous air pollutants. Scientists are working to identify microbes that will clean up more stubborn pollutants.     

E2F-1 induces proliferation-specific genes and suppresses squamous differentiation-specific genes in human epidermal keratinocytes

Squamous differentiation of keratinocytes is associated with decreases in E2F-1 mRNA expression and E2F activity, and these processes are disrupted in squamous cell carcinoma cell lines. We now show that E2F-1 mRNA expression is increased in primary squamous cell carcinomas of the skin relative to normal epidermis. To explore the relationship between E2F-1 and squamous differentiation further, we examined the effect of altering E2F activity in primary human keratinocytes induced to differentiate. Promoter activity for the proliferation-associated genes, cdc2 and keratin 14, are inhibited during squamous differentiation. This inhibition can be inhibited by overexpression of E2F-1 in keratinocytes. Overexpression of E2F-1 also suppressed the expression of differentiation markers (transglutaminase type 1 and keratin 10) in differentiated keratinocytes. Blocking E2F activity by transfecting proliferating keratinocytes with dominant negative E2F-1 constructs inhibited the expression of cdc2 and E2F-1, but did not induce differentiation. Furthermore, expression of the dominant negative construct in epithelial carcinoma cell lines and normal keratinocytes decreased expression from the cdc2 promoter. These data indicate that E2F-1 promotes keratinocyte proliferation-specific marker genes and suppresses squamous differentiation-specific marker genes. Moreover, these data indicate that targeted disruption of E2F-1 activity may have therapeutic potential for the treatment of squamous carcinomas. Oncogene (2000).     

Is the investigation of most stress incontinence really necessary?

The case histories of 494 women referred to a urodynamic clinic with the symptom of stress incontinence were studied. None had undergone previous incontinence surgery. In only 12 patients was stress incontinence the sole symptom. In the remainder, symptoms suggestive of detrusor instability were present in 417, of a voiding disorder in 261 and of an inflammatory disorder in 166. The sign of stress incontinence was present in only 168 patients and was not a reliable guide to the diagnosis of genuine stress incontinence. Urodynamic studies were necessary in 488 patients in order to obtain an accurate diagnosis.     

Transvaginal ultrasound in the assessment of bladder volumes in women. Preliminary report

Transvaginal linear array ultrasound is described as a method of measuring bladder volumes in the range 2 to 175 ml, overcoming the limitations of abdominal ultrasound at these smaller (though clinically important) volumes. The mean error over the range 10 to 175 ml was 23%. Statistical analysis of preliminary data obtained by this technique shows that bladder volume in ml can be calculated by the formula: Volume = 5.9 x (height x depth) - 14.6 ml (95% confidence limits = +/- 37 ml)