Scrotal temperatures do not differ among young boys wearing disposable or reusable diapers.

BACKGROUND/AIMS: This study investigated the effect of specific, commonly used diaper types on scrotal temperatures in normal healthy, young boys. These included both modern disposable and reusable diapers as well as various types of protective outer coverings that are in common use in both North America and Europe METHODS: Scrotal and skin surface temperatures were continuously monitored in healthy, young males using a computerized data-logging system based on temperature probes specifically designed for paediatric studies. These systems could be used either tethered to the PC or made completely portable depending upon the age and activity of the child being measured. Based on our results from several pilot studies, it became clear that the best way to determine if disposable and reusable diapers differ with regard to their impact on scrotal temperatures is to run these comparisons under controlled laboratory conditions where "diaper type" was the primary variable. A 2-h time period was chosen to ensure that sufficient time had elapsed for thermal equilibrium to be established under the diapers. We also felt it necessary to study the impact of urination and simulated this condition over the last 15 min using standardized methods. In addition to the skin surface temperatures, we also measured the temperature of the tympanic membrane using an infrared thermometer as an estimate of "core" temperature for each individual at various times during the session. RESULTS AND CONCLUSIONS: In this study, we have clearly shown that scrotal temperatures are the same whether the child is wearing disposable or reusable cloth diapers with a protective cover. The only situation in which scrotal temperatures were found to be lower is when the cloth diaper is used alone without a protective cover but this is not representative of how these products are actually used. We also found that on average scrotal temperatures are significantly lower than core for each diaper type. Occasionally, we did see individuals in which the maximal scrotal temperatures approached core temperatures but in every case the thermal sensors were soiled by a bowel movement. We also found that skin surface temperatures increased not only when covered by a diaper but also due to the thermal insulation provided by outer garments and blankets.

Method to produce 9(S)-hydroperoxides of linoleic and linolenic acids by maize lipoxygenase.

Seed from maize (corn) Zea mays provides a ready source of 9-lipoxygenase that oxidizes linoleic acid and linolenic acid into 9(S)-hydroperoxy-10(E),12(Z)-octadecadienoic acid and 9(S)-hydroperoxy-10(E),12(Z),15(Z)-octadecatrienoic acid, respectively. Corn seed has a very active hydroperoxide-decomposing enzyme, allene oxide synthase (AOS), which must be removed prior to oxidizing the fatty acid. A simple pH 4.5 treatment followed by centrifugation removes most of the AOS activity. Subsequent purification by ammonium sulfate fractional precipitation results in negligible improvement in 9-hydroperoxide formation. This facile alternative method of preparing 9-hydroperoxides has advantages over other commonly used plant lipoxygenases.

The history of South American tropical precipitation for the past 25,000 years.

Long sediment cores recovered from the deep portions of Lake Titicaca are used to reconstruct the precipitation history of tropical South America for the past 25,000 years. Lake Titicaca was a deep, fresh, and continuously overflowing lake during the last glacial stage, from before 25,000 to 15,000 calibrated years before the present (cal yr B.P.), signifying that during the last glacial maximum (LGM), the Altiplano of Bolivia and Peru and much of the Amazon basin were wetter than today. The LGM in this part of the Andes is dated at 21,000 cal yr B.P., approximately coincident with the global LGM. Maximum aridity and lowest lake level occurred in the early and middle Holocene (8000 to 5500 cal yr B.P.) during a time of low summer insolation. Today, rising levels of Lake Titicaca and wet conditions in Amazonia are correlated with anomalously cold sea-surface temperatures in the northern equatorial Atlantic. Likewise, during the deglacial and Holocene periods, there were several millennial-scale wet phases on the Altiplano and in Amazonia that coincided with anomalously cold periods in the equatorial and high-latitude North Atlantic, such as the Younger Dryas.

Characterization of a C-5,13-Cleaving Enzyme of 13(S)-Hydroperoxide of Linolenic Acid by Soybean Seed.

An activity was found in mature soybean seeds (Glycine max L. cv Century) that cleaved 13(S)-hydroperoxy-9(Z),11(E),15(Z)-octadecatrienoic acid (13S-HPOT) into 13-oxo-9(Z),11(E)-tridecadienoic acid and two isomeric pentenols, 2(Z)-penten-1-ol and 1-penten-3-ol. Isomeric pentene dimers were also produced and were presumably derived from the combination of two pentene radicals. 13(S)-Hydroperoxy-9(Z),11(E)-octadecadienoic acid (13S-HPOD) was, by contrast, a poor substrate. Activity with 13S-HPOT increased 24-fold under anaerobic conditions reminiscent of a similar anaerobic promoted reaction of 13S-HPOD catalyzed by lipoxygenase (LOX) in the presence of linoleic acid. However, prior to ion-exchange chromatography, cleavage activity did not require linoleic acid. After separation by gel filtration followed by ion-exchange chromatography, cleavage activity was lost but reappeared in the presence of either linoleic acid or dithiothreitol. Under these conditions cleavage activity was coincident with the activity of types 1 and 2 LOX. LOX inhibitors suppressed the cleavage reaction in a manner similar to inhibition of LOX activity. Heat-generated alkoxyl radicals derived from either 13S-HPOT or 13S-HPOD afforded similar products and yields of 13-oxo-9(Z),11(E)-tridecadienoic acid compared to the enzymic reaction. The product 1-penten-3-ol may be the precursor of the "raw-bean" volatile ethylvinylketone.

Evidence for accelerated skin wrinkling among developmentally delayed individuals with Down's syndrome.

Down's Syndrome (DS) is a genetic disorder involving mental retardation which is reported to be a condition of accelerated aging. However, few studies exist which examine age-dependent changes in DS and these studies fail to include a control group. In the present study a non-invasive, painless, and easily obtainable measure reflecting age-dependent topographical changes of the skin (skin wrinkling) was obtained in 15 DS subjects, 14 developmentally disabled (DD) (mentally retarded) controls (DD controls) and 16 healthy controls of similar ages ranging from 22 to 51 years. The healthy control group failed to show correlations of skin measures with age, as predicted for the age-range of these subjects, based on results of previous studies. However, the DS group showed significant correlations of all skin measures from relatively non-sun-exposed and sun-exposed skin sites, with age. The DD control also showed significant correlations with age of several but not all skin sites and the correlation coefficients tended to be less than that of the DS; at least, when contrasted with the healthy controls the DS showed greater values of several skin measures suggestive of accelerated skin wrinkling. These results provide evidence for accelerated aging of the skin, and possibly greater effects of sun-exposure on skin wrinkling, in DS and possibly (DD) individuals in contrast to healthy individuals without a genetic disorder and without mental retardation.

Alteration of argon laser-induced scars by the pulsed dye laser.

Ten patients with portwine stains (PWS) with test sites previously exposed to an argon laser were evaluated and subsequently treated with five pulsed dye (585 nm) laser treatments over a 10 month period. Clinical assessments, skin surface texture analyses using optical profilometry, and light microscopic histological evaluations were performed prior to commencement and at the end of the study in all ten patients. A change in the skin texture with return of skin markings approximating those of normal skin measured by optical profilometry was observed in the argon treated PWS skin following pulsed dye laser treatments.

Skin replica analysis of photodamaged skin after therapy with tretinoin emollient cream.

Computerized image analysis of silicone replicas, a reproducible, objective technique for measuring skin topography, was used in addition to clinical measures in two multicenter, double-blind, randomized, controlled studies of tretinoin emollient cream, a new formulation for treating photodamaged skin. Previously, the skin replica technique had been successfully used in a pilot study of tretinoin 0.05% cream by one investigator. In the present studies, subjects treated for 24 weeks with tretinoin emollient 0.05% cream consistently showed more improvement in skin topography than did vehicle-treated patients. A 0.01% concentration of tretinoin emollient cream also improved skin topography to a greater extent than the vehicle, while the lowest concentration tested (0.001%) showed little difference from vehicle. These results, reflecting a smoothening of the skin surface in tretinoin emollient cream-treated subjects, were consistent with clinical data showing greater improvement in fine wrinkling and roughness after tretinoin emollient cream therapy than after vehicle therapy. Findings from these multicenter studies confirm the value of the skin replica technique and help establish the efficacy of tretinoin emollient 0.05% cream for photodamaged skin.

Computerized image analysis of full-hand touch plates: a method for quantification of surface bacteria on hands and the effect of antimicrobial agents.

A method is described for quantification of the bacterial flora on the hand surface. Computer-assisted image analysis of bacterial growth of large full-hand touch plates provides a quantifiable measure of the bacterial flora on the hand surface. Image analysis pixel intensity values showed a significant correlation (P less than 0.0001) with colony forming unit values determined by the glove juice method. Image analysis of impressions from hands treated with various antimicrobial agents in detergent bases showed that 4% chlorhexidine gluconate produces a 96% reduction after a 30 s washing and 98% reduction after a 3 min washing while 7.5% povidone-iodine and 1% triclosan produce a 77% and 70% reduction after 3 min respectively, and 70% isopropanol produces a 98% reduction after a 30 s wash.

Treatment of photodamaged facial skin with topical tretinoin.

A 6-month, randomized, double-blind, vehicle-controlled study was conducted with 0.05% tretinoin cream once daily in the treatment of photodamaged facial skin. Significant amelioration of many of the signs of photodamage were achieved with minimal side effects. Clinical grading showed significant improvement both in the assessments based on changes in clinical scores and in pre- and posttreatment comparisons of standardized photographs. Fine wrinkling, coarse wrinkling, sallowness, looseness, and hyperpigmentation were significantly improved with tretinoin therapy. Furthermore, a self-appraisal questionnaire indicated that tretinoin-treated patients, but not vehicle-treated patients, were able to perceive improvement in their facial appearance. An objective method based on digital image processing of silicone rubber casts obtained from the crow's-feet area also indicated that the skin surface topography was smoother and less wrinkled in the tretinoin-treated group compared with the vehicle-control group.

Optical profilometry: an objective method for quantification of facial wrinkles.

Facial fine lines and wrinkles can be faithfully captured by silicone rubber impression materials. Computerized digital image processing of such specimens provides objective measurement of the skin's topography, which has a significant degree of correlation with clinical grading. Optical profilometry provides a dimension of objectivity that can complement clinical assessment in the study of agents that may be useful in the therapy of photodamaged skin.