Specimen Collection for Translational Studies in Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is a chronic inflammatory disorder characterized by painful nodules, sinus tracts, and scars occurring predominantly in intertriginous regions. The prevalence of HS is currently 0.053-4%, with a predominance in African-American women and has been linked to low socioeconomic status. The majority of the reported literature is  retrospective, population based, epidemiologic studies. In this regard, there is a need to establish a repository of biospecimens, which represent appropriate gender and racial demographics amongst HS patients. These efforts will diminish knowledge gaps in understanding the disease pathophysiology. Hence, we sought to outline a step-by-step protocol detailing how we established our HS biobank to facilitate the formation of other HS tissue banks. Equipping researchers with carefully detailed processes for collection of HS specimens would accelerate the accumulation of well-organized human biological material. Over time, the scientific community will have access to a broad range of HS tissue biospecimens, ultimately leading to more rigorous basic and translational research. Moreover, an improved understanding of the pathophysiology is necessary for the discovery of novel therapies for this debilitating disease. We aim to provide high impact translational research methodology for cutaneous biology research and foster multidisciplinary collaboration and advancement of our understanding of cutaneous diseases.

Lessons learned from the development of a hidradenitis suppurativa xenograft mouse model

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease originating from the pilosebaceous unit, in which patients develop painful abscesses, sinus tracts, nodules and scarring, typically in intertriginous areas. Major gaps in our understanding of HS exist, and these may be partially due to the lack of an animal model for experimental studies. We developed an HS xenograft mouse model using human HS lesions grafted onto immunocompromised mice. Although the model had its limitations, several informative lessons were learned, which may contribute to future attempts at an HS animal model.

The new VARSKIN 4 photon skin dosimetry model

A new photon skin dosimetry model, described here, was developed as the basis for the enhanced VARSKIN 4 thin tissue dosimetry code. The model employs a point-kernel method that accounts for charged particle build-up, photon attenuation and off-axis scatter. Early comparisons of the new model against Monte Carlo particle transport simulations show that VARSKIN 4 is highly accurate for very small sources on the skin surface, although accuracy at shallow depths is compromised for radiation sources that are on clothing or otherwise elevated from the skin surface. Comparison results are provided for a one-dimensional point source, a two-dimensional disc source and three-dimensional sphere, cylinder and slab sources. For very small source dimensions and sources in contact with the skin, comparisons reveal that the model is highly predictive. With larger source dimensions, air gaps or the addition of clothing between the source and skin; however, VARSKIN 4 yields over-predictions of dose by as much as a factor of 2 to 3. These cursory Monte Carlo comparisons confirm that significant accuracy improvements beyond the previous version were achieved for all geometries. Improvements were obtained while retaining the VARSKIN characteristic user convenience and rapid performance.

Development and deployment of an underway radioactive cesium monitor off the Japanese coast near Fukushima Dai-ichi

A custom radiation monitoring system was developed by Oregon State University at the request of the Woods Hole Oceanographic Institute to measure radioactive cesium contaminants in the ocean waters near Fukushima Dai-ichi Nuclear Power Plant. The system was to be used on board the R/V Ka'imikai-O-Kanaloa during a 15 d research cruise to provide real-time approximations of radionuclide concentration and alert researchers to the possible occurrence of highly elevated radionuclide concentrations. A NaI(Tl) scintillation detector was coupled to a custom-built compact digital spectroscopy system and suspended within a sealed tank of continuously flowing seawater. A series of counts were acquired within an energy region corresponding to the main photopeak of (137)Cs. The system was calibrated using known quantities of radioactive (134)Cs and (137)Cs in a ratio equating to that present at the reactors' ocean outlet. The response between net count rate and concentration of (137)Cs was then used to generate temporal and geographic plots of (137)Cs concentration throughout the research cruise in Japanese coastal waters. The concentration of (137)Cs was low but detectable, reaching a peak of 3.8 ± 0.2 Bq/L.

Ca 125 as a marker of tumor activity in advanced urothelial malignancy

PURPOSE

The discovery of increased CA 125 in a patient with metastatic bladder carcinoma prompted a prospective study to screen those referred for consideration of adjuvant or palliative chemotherapy of advanced urothelial malignancy for high serum CA 125. Although CA 125 is a useful marker of ovarian cancer and, reportedly, is expressed by a few other tumors, to our knowledge no association with transitional cell malignancy of the urothelium has been previously described.

MATERIALS AND METHODS

A group of 68 patients with nodal or metastatic disease was examined. A total of 60 patients had lower urinary tract tumors, 6 had renal or ureteral transitional cell carcinoma and 2 had both lesions. Of these patients 21 underwent surgery alone, 40 underwent both surgery and chemotherapy, and 5 were treated by chemotherapy only. There were 2 patients who received no treatment. Periodic serum CA 125 was obtained in cases found to be initially marker positive and with a change in clinical status.

RESULTS

Of the 68 patients 48 (71%) had increased CA 125. Variation in the serum level with change in disease status was often dramatic (mean 516.3 units per dl.). Of 30 radiologically measurable disease progressions 16 were accompanied by increasing CA 125. Increases were seen in 80% of patients who had increased baseline levels. In 5 cases marker increases were seen in the absence of measurable progression but the clinical course indicated therapeutic failure. Decreasing CA 125 reflected 3 of 5 imaged regressions. Overall, a 42% decrease in median levels was seen after chemotherapy. Significantly more cases of metastatic or residual disease were marker positive.

CONCLUSIONS

CA 125 appears to be a marker of disease activity in a patient subset with advanced urothelial malignancy. The clinical use of CA 125 in this population is worthy of further study.