Assessing localized skin-to-fat water in arms of women with breast cancer via tissue dielectric constant measurements in pre- and post-surgery patients.

BACKGROUND: Skin-to-fat tissue dielectric constant (TDC) values at 300 MHz largely depend on tissue water and provide a rapid way to assess skin water by touching skin with a probe for approximately 10 s. This method has been used to investigate lymphedema features accompanying breast cancer (BC), but relationships between TDC and nodes removed or symptoms is unclear. Our goals were: (1) to compare TDC values in BC patients prior to surgery (group A) and in patients who had BC-related surgery (group B) to determine if TDC of group B were related to nodes removed and reported symptoms and (2) to develop tentative lymphedema-detection thresholds. METHODS: Arm volumes and TDC values of at-risk and contralateral forearms and biceps were determined in 103 women awaiting surgery for BC and 104 women who had BC-related surgery 26.3 ± 17.5 months prior to evaluation. Inter-arm ratios (at-risk/contralateral) were determined and patients answered questions about lymphedema-related symptoms. RESULTS: Inter-arm TDC ratios for group A forearm and biceps were respectively 1.003 ± 0.096 and 1.012 ± 0.143. Group B forearm ratios were significantly greater, and among group B patients who reported at least one symptom there was a significant correlation between TDC ratios and symptom burden and nodes removed. CONCLUSIONS: Inter-arm TDC ratios are significantly related to symptoms and nodes removed. Ratios increase with increasing symptom score and might be used to detect pre-clinical unilateral lymphedema using TDC ratio thresholds of 1.30 for forearm and 1.45 for biceps. Threshold confirmation awaits targeted prospective studies but can serve as guideposts to provide quantitative and easily done tracking assessments during follow-up visits.

Patterns of temporal changes in tissue dielectric constant as indices of localized skin water changes in women treated for breast cancer: a pilot study.

BACKGROUND: Our goal was to characterize temporal patterns of skin Tissue Dielectric Constant (TDC) as a foundation for possible TDC use to detect and quantify lymphedema. Although limb volumes and bioimpedance analysis (BIA) are used for this purpose, potential TDC-method advantages are that it can be done in about 10 seconds at any body site to depths from 0.5 to 5.0 mm below the epidermis. METHODS AND RESULTS: TDC at forearm, biceps, axilla, and lateral thorax, and BIA values and arm volumes were measured in 80 women with breast cancer prior to surgery and in decreasing numbers at 3, 6, 12, 18, and 24 months post-surgery. Results show that TDC values, reflecting water content in the measurement volume, vary by site and depth but that at-risk/contralateral side ratio (A/C) is relatively independent of site and depth and is the preferred TDC parameter to detect tissue water changes over time in unilateral conditions. Among sites measured, lateral thorax, followed by forearm, appears most useful for TDC measurements with axilla least useful. Pre-surgery TDC inter-side values and A/C ratios showed no significant inter-side differences, suggesting that breast cancer presence per se did not alter tissue water status in this patient population. Sequential changes in TDC A/C ratios detected a greater number of patients who had inter-arm ratio increases exceeding 10% than were detected using BIA ratios. This may indicate a greater sensitivity to localized tissue water changes with the TDC-method. CONCLUSIONS: TDC is a technically viable and potentially useful method to track skin water changes in persons treated for breast cancer.

Patogénesis de la infección por Helicobacter pylori / Pathogenesis of infection due to Helicobacter pylori

La infección por Helicobacter pylori afecta a más del 50 por ciento de la población mundial y constituye la causa principal del desarrollo de afecciones como úlceras gástricas y duodenales, y el cáncer gástrico. Aún así, se conoce que la mayoría de las personas infectadas no desarrollan ninguna de estas enfermedades porque la patogénesis inducida por este microorganismo depende de diferentes factores que incluyen características del hospedero, el ambiente en el que se desarrolla y la cepa infectante. En este trabajo se revisó y actualizó el tema de la patogénesis de la infección por H. pylori para ampliar el conocimiento de los principales factores que conducen al desarrollo de las afecciones severas y, por tanto, coadyuvar al mejor tratamiento de esta infección en nuestra población, que tiene alta prevalencia de H. pylori

Infection due to Helicobacter pylori affects to more than 50 percent of world population and it is the leading cause of development of affections like gastric and duodenal ulcers and the gastric cancer. Even so, it is known that most of persons infected don't developed any of these diseases because of the pathogenesis induced by this microorganism depends of different factors including host features, the environment where it is developed and the infectious strain. In present paper the subject on pathogenesis of infection due to H. pylori was reviewed and updated to expand the knowledge of the main factors leading to the development of severe affections and thus, contribute to a better treatment of this infection in our population, due to the high prevalence of H. pylori

Patogénesis de la infección por Helicobacter pylori / Pathogenesis of infection due to Helicobacter pylori

La infección por Helicobacter pylori afecta a más del 50 por ciento de la población mundial y constituye la causa principal del desarrollo de afecciones como úlceras gástricas y duodenales, y el cáncer gástrico. Aún así, se conoce que la mayoría de las personas infectadas no desarrollan ninguna de estas enfermedades porque la patogénesis inducida por este microorganismo depende de diferentes factores que incluyen características del hospedero, el ambiente en el que se desarrolla y la cepa infectante. En este trabajo se revisó y actualizó el tema de la patogénesis de la infección por H. pylori para ampliar el conocimiento de los principales factores que conducen al desarrollo de las afecciones severas y, por tanto, coadyuvar al mejor tratamiento de esta infección en nuestra población, que tiene alta prevalencia de H. pylori(AU)

Infection due to Helicobacter pylori affects to more than 50 percent of world population and it is the leading cause of development of affections like gastric and duodenal ulcers and the gastric cancer. Even so, it is known that most of persons infected don't developed any of these diseases because of the pathogenesis induced by this microorganism depends of different factors including host features, the environment where it is developed and the infectious strain. In present paper the subject on pathogenesis of infection due to H. pylori was reviewed and updated to expand the knowledge of the main factors leading to the development of severe affections and thus, contribute to a better treatment of this infection in our population, due to the high prevalence of H. pylori(AU)

Endothelin 3 induces skin pigmentation in a keratin-driven inducible mouse model.

Endothelin 3 (Edn3) encodes a ligand important to developing neural crest cells and is allelic to the spontaneous mouse mutation occurring at the lethal spotting (ls) locus. Edn3(ls/ls) mutants exhibit a spotted phenotype due to reduced numbers of neural crest-derived melanocyte precursors in the skin. In this study, we show that when Edn3 is driven by the keratin 5 promoter and thereby placed proximal to melanocyte lineage cells, adult mice manifest pigmented skin harboring dermal melanocytes. Using a tetracycline inducible system, we show that the postnatal expression of Edn3 is required to maintain these dermal melanocytes, and that early expression of the Edn3 transgene is important to the onset of the hyperpigmentation phenotype. Crosses into Edn3(ls/ls) mutants demonstrate that the Edn3 transgene expression does not fully compensate for the endogenous expression pattern. Crosses into tyrosine kinase receptor Kit(Wv) mutants indicate that Edn3 can partially compensate for Kit's role in early development. Crosses into A(y) mutant mice considerably darkened their yellow coat color suggesting a previously unreported role for endothelin signaling in pigment switching. These results demonstrate that exogenous Edn3 affects both precursors and differentiated melanocytes, leading to a phenotype with characteristics similar to the human skin condition dermal melanocytosis.