Two classes of single-stranded regions in DNA from sea urchin embryos.

Native DNA from sea urchin embryos contains single-stranded regions (gaps) of up to 3000 nucleotides. The longer gaps (more than 1400 nucleotides) are nonrandomly distributed and are rich in histone gene sequences, other moderately repetitive sequences, and polypyrimidines. The shorter gaps are associated with DNA replication. A method for isolation of the two classes of single-stranded DNA pieces is reported.

Intrinsic 4-1BB signals are indispensable for the establishment of an influenza-specific tissue-resident memory CD8 T-cell population in the lung.

The induction of long-lived heterotypic T-cell protection against influenza virus remains elusive, despite the conservation of T-cell epitopes. T-cell protection against influenza is critically dependent on lung-resident memory T cells (Trm). Here we show that intranasal administration of 4-1BBL along with influenza nucleoprotein in a replication-defective adenovirus vector to influenza pre-immune mice induces a remarkably stable circulating effector memory CD8 T-cell population characterized by higher IL-7Rα expression than control-boosted T cells, as well as a substantial lung parenchymal CD69+ CD8 Trm population, including both CD103+ and CD103- cells. These T-cell responses persist to greater than 200 days post-boost and protect against lethal influenza challenge in aged (year old) mice. The expansion of the nucleoprotein-specific CD8 Trm population during boosting involves recruitment of circulating antigen-specific cells and is critically dependent on local rather than systemic administration of 4-1BBL as well as on 4-1BB on the CD8 T cells. Moreover, during primary influenza infection of mixed bone marrow chimeras, 4-1BB-deficient T cells fail to contribute to the lung-resident Trm population. These findings establish both endogenous and supraphysiological 4-1BBL as a critical regulator of lung-resident memory CD8 T cells during influenza infection.

Specific sequences within single-stranded regions in the sea urchin embryo genome.

Naturally occurring single-stranded regions in native DNA isolated from sea urchin embryos at the morula stage were removed by digestion with S1 nuclease. Renaturation experiments show that this nuclease removes a portion of the repetitive sequences renaturing between Cot 10(-2) and 20 including about two-thirds of the histone genes. The latter was shown by hybridization of S1-treated morula DNA to either sea urchin 9 S polysome RNA (containing histone mRNA) or to Escherichia coli plasmid DNA carrying sea urchin histone genes. Hybridization of sea urchin DNA to strand-separated recombinant histone gene DNA shows that it is the histone gene antisense strand that is missing from the gapped regions of the native DNA from morulae. Present and previous data support the conclusion that a portion of the single-stranded regions are not in random positions in the embryo genome and do not result from the unwinding of DNA in vivo at replication sites.

New coal tar extract and coal tar shampoos. Evaluation by epidermal cell DNA synthesis suppression assay.

Coal tar therapy has been used for many years in the treatment of scaling skin diseases, including psoriasis and eczema. Previous studies of the potential effectiveness of tar have utilized phototoxic erythema assays with long-wave ultraviolet light (UV-A). However, in clinical use, coal tar is rarely used with UV-A, particularly for scalp disease. Therefore, we investigated a nonphototoxic approach to evaluate different coal tar products. Coal tar was found to suppress epidermal cell DNA synthesis in the hairless mouse model, and this is the basis for the assay presented. Using the epidermal cell DNA synthesis suppression assay, we observed that crude coal tar and a new extract of crude coal tar were equally effective and that a concentration gradient effect was achieved. In addition, four commercial coal tar shampoos assayed varied greatly in their ability to suppress epidermal cell DNA synthesis. One shampoo was washed after ten minutes and no significant alteration of suppressive effect was seen.

Evaluation of mild skin cleansers.

Each person makes the decision of how best to care for his or her own skin. Among the prime concerns, especially for facial skin, is the type of dirt, debris, or make-up to be removed. In most cases, all products do an adequate job in the removal of dirt; if not, the washing techniques can be modified to accomplish the task at hand. What cannot be controlled are the adverse side effects inherent in the use of that product. These adverse properties include damages to the barrier function of the skin; increased susceptibility to environmental sources of irritation and sensitization; frank irritation responses, such as erythema and edema; and reduction of the cosmetic qualities of the skin, such as degree of moisture and smoothness. Part of the problem is that most of these changes are subtle, occurring slowly over time. Often, the association of these problems with the use of a particular facial cleansing regimen is overlooked. The typical woman uses as many as 10 to 15 facial cosmetic and cleansing products each day, making the identification of a problem even more difficult. It is important to identify the risks associated with individual products and with product categories in general. Although the identification of a safe group of products to use for facial cleansing is desirable, the results of this investigation indicate that there are no simple answers. It has been assumed that because moisturizing cream formulations are routinely safe and mild in general use, a cleansing product in the same general form would share these attributes. We can see from the results in Table 2 and Figures 2, 3, 5, 7, and 9 that cleansing creams are not uniformly superior to cleansing bars in the key attributes that are used to evaluate mildness. In each evaluation there were individual cleansing creams that demonstrated statistically weaker performance than did cleansing bars in general. As a group, cleansing creams did well in the cosmetic categories of dryness and texture but surprisingly poorly in such indicators of clinical safety as erythema and TEWL. Further evaluation of the components of the facial-washing regimens proposed by the manufacturers of many of the cleansing-cream products involved the direct comparison of a cleansing cream against that same product used with an alcohol-based toning product. In all cases, the addition of alcohol-based products to the cleaning protocol reduced the cosmetic and clinical safety of the regimen (see Table 2 and Figures 3, 5, 7, and 9).(ABSTRACT TRUNCATED AT 400 WORDS)

Differentially imprinted innate immunity by mucosal boost vaccination determines antituberculosis immune protective outcomes, independent of T-cell immunity.

Homologous and heterologous parenteral prime-mucosal boost immunizations have shown great promise in combating mucosal infections such as tuberculosis and AIDS. However, their immune mechanisms remain poorly defined. In particular, it is still unclear whether T-cell and innate immunity may be independently affected by these immunization modalities and how it impacts immune protective outcome. Using two virus-based tuberculosis vaccines (adenovirus (Ad) and vesicular stomatitis virus (VSV) vectors), we found that while both homologous (Ad/Ad) and heterologous (Ad/VSV) respiratory mucosal boost immunizations elicited similar T-cell responses in the lung, they led to drastically different immune protective outcomes. Compared with Ad-based boosting, VSV-based boosting resulted in poorly enhanced protection against tuberculosis. Such inferior protection was associated with differentially imprinted innate phagocytes, particularly the CD11c(+)CD11b(+/-) cells, in the lung. We identified heightened type 1 interferon (IFN) responses to be the triggering mechanism. Thus, increased IFN-ß severely blunted interleukin-12 responses in infected phagocytes, which in turn impaired their nitric oxide production and antimycobacterial activities. Our study reveals that vaccine vectors may differentially imprint innate cells at the mucosal site of immunization, which can impact immune-protective outcome, independent of T-cell immunity, and it is of importance to determine both T-cell and innate cell immunity in vaccine studies.

Animal assays for anti-psoriatic, retinoid and sun protective agents.

It is possible to evaluate different dermatological therapeutic agents intended for human use in a variety of animal assays. This review will discuss some of these assays, and attempt to correlate animal and human skin responses. Psoriasis is a disease where changes in epidermal proliferation may be an important factor. It is possible to assay potential anti-psoriatic agents by measuring their ability to suppress DNA synthesis in the epidermis of hairless mice. This assay is predictive of the anti-psoriatic effectiveness of numerous agents including a variety of anti-proliferative drugs and anthralin, and has been used to evaluate the potential efficacy of purified coal tar shampoos and body preparations. The activity of the polyamine biosynthesis enzyme ornithine decarboxylase (ODC) is elevated in psoriatic skin, and it is induced in mouse epidermis by tape stripping. Retinoids can inhibit the induction of ODC activity, and this inhibition may be used to evaluate novel synthetic retinoids. Retinoids have beneficial effects on the abnormal keratinization found in various diseases. Rhino mice have multiple keratin-filled epidermal utricles, and the size of these is reduced by retinoid treatment. Observing the changes in the size of the utricles can be utilized to evaluate the effects of retinoids on keratinization. Sunscreen agents are tested on human volunteers by observing their ability to inhibit the erythema induced by exposure to solar-simulated light, to obtain a sun protection factor (SPF). It is possible to utilize the ability of sunscreens to inhibit other actinic-induced changes in the skin using animals. Parameters that may be measured include changes in DNA synthesis and ODC activity in the epidermis following ultraviolet irradiation. Some of these assays correlate well with human SPF determinations.

Coal tar phototherapy for psoriasis reevaluated: erythemogenic versus suberythemogenic ultraviolet with a tar extract in oil and crude coal tar.

Recent studies have questioned the therapeutic value of coal tar versus ultraviolet (UV) radiation and their relative necessity in phototherapy for psoriasis. In this investigation, different aspects of tar phototherapy have been studied in single-blind bilateral paired comparison studies. The effects of 1% crude coal tar were compared with those of petrolatum in conjunction with erythemogenic and suberythemogenic doses of ultraviolet light (UVB) using a FS72 sunlamp tubed cabinet. Crude coal tar was clinically superior to petrolatum with suberythemogenic ultraviolet. With the erythemogenic UVB, petrolatum was equal in efficacy to crude coal tar. Suberythemogenic UVB was also used adjunctively to compare the effects of a 5% concentration of a tar extract in an oil base to 5% crude coal tar in petrolatum or the oil base without tar. The tar extract in oil plus suberythemogenic UVB produced significantly more rapid improvement than the oil base plus UVB. The direct bilateral comparison of equal concentrations of tar extract in oil base versus crude coal tar in petrolatum in a suberythemogenic UV photo regimen revealed no statistical differences between treatments. In a study comparing tar extract in oil and the oil base without ultraviolet radiation, the tar extract in oil side responded more rapidly. This demonstrates a direct effect of tar alone in therapy. We have also studied the effects of erythemogenic and suberythemogenic UVB with and without tar extract in oil in the hairless mouse epidermal deoxyribonucleic acid (DNA) synthesis suppression assay. It was found that erythemogenic dosages of UVB produced near maximal inhibition of DNA synthesis with or without coal tars. Suberythemogenic dosages of UVB produced submaximal suppression of DNA synthesis that was enhanced by adjunctive coal tar but not by vehicle, findings which are consistent with the above clinical results. These studies suggest that coal tars combined with suberythemogenic UVB therapy is a practical alternative (to more aggressive UVB therapy without coal tar) which reduces the UVB exposure to the patient.

Efficacy of hydroquinone cream (USP 4%) used alone or in combination with salicylic acid peels in improving photodamage on the neck and upper chest.

BACKGROUND: Salicylic acid, hydroquinone, and glycolic acid have been proved effective in the treatment of photodamaged facial skin. Few reports are available on the treatment of photodamage on the neck and upper chest. OBJECTIVE: This study's purpose was to evaluate the efficacy of a cream containing 4% hydroquinone and 2% glycolic acid (LUSTRA) used alone or with salicylic acid peels in reversing actinic damage on the neck and upper chest. METHODS: Nineteen women with moderate to advanced photodamage on the neck and upper chest applied a cream containing 4% hydroquinone and 2% glycolic acid twice daily on photodamaged areas for 12 weeks. Nine of these subjects had salicylic acid peels every 3 weeks. Improvements were assessed by the investigator, the subjects, and Mexameter readings measuring melanin and erythema levels. RESULTS: The result shows that there was a 33-71% improvement in photodamage, hyperpigmentation, texture, fine lines, dryness, tone, and clarity in both groups. There were no significant differences between the two treatments. CONCLUSION: Hydroquinone 4% cream with 2% glycolic acid is safe and effective in improving photodamage on the neck and upper chest when used alone or in combination with salicylic acid peels.