Elucidating interactions between the dermal fibroblast phenotype, inflammatory signals and extra-cellular matrix components

The study of dermal wound healing has long been used to elucidate the cellular and molecular processes guiding the connective tissue response to injury. Of particular interest are the mechanisms by which soluble mediators, including inflammatory signals, guide fibroblast activity within the wound bed. This thesis addresses the role of prostaglandin E2 (PGE2) in the regulation of fibroblast activities relevant to restoration of tissue structure and function. Although PGE2 has been previously shown to play an important role in various wound healing steps, its precise contribution to the overall outcome of dermal repair is unclear. Using three well defined human dermal fibroblast phenotypes this study demonstrates that while PGE2 signaling during dermal repair triggers pro-inflammatory cascades, its effects on fibroblast activities are putatively anti-fibrotic. Specifically, exogenous PGE2 decreases the migratory and contractile potential of dermal fibroblasts through destabilization of the actin cytoskeleton and inhibits endogenous collagen synthesis. While PGE2 effects on fibroblast activity are largely conserved across phenotypes, fetal fibroblasts maintain a quantitatively diminished response to PGE2-induced alterations of cytoskeletal dynamics.Upon further analysis, this effect was shown to be representative of a larger intrinsic fibroblast phenotype. Fetal dermal fibroblasts were shown to maintain elevated rates of migration and contraction, as part of a generalized hyperactive dynamic state. Surprisingly, this phenotype was found to be sufficiently robust so as to persist despite changes in substrate and environmental constraints. In light of this finding, one additional approach was used to ascertain the robustness of the fetal fibroblast. Transplantation of fetal dermal fibroblasts into an adult wound environment was used to assess whether the intrinsic fetal fibroblast phenotype can survive the multitude of events comprising adult wound healing. While results are preliminary, this approach does present a useful tool for future studies aimed at elucidating the precise fetal fibroblast phenotype and its contribution to overall wound healing response

Nierenfunktion Kinase-defizienter Mäuse

Die Arbeit untersucht die Nierenfunktion Kinase-defizienter MäuseErratum am 19.09.2019 auf Veranlassung des Dekanates MNF hinzugefügt. Siehe http://hdl.handle.net/10900/93741For in vivo experiments regarding the regulation of Ca 2+ channel the sgk1-/- mice under control diet immunohistochemistry revealed lower abundance of TRPV5 and calbindin D-28K protein than in sgk1+/+ mice (colocalized in distal convoluted tubules and connecting tubules). Renal Ca2+ excretion under cd was significantly lower in sgk1-/- than in sgk1+/+ mice. Under a Ca2+-deficient diet TRPV5 protein abundance markedly increased in both genotypes, clearly pointing to SGK1-independent regulation of TRPV5, but renal excretion of Ca2+ decreased to the same levels in both phenotypes. Under a Ca2+-deficient diet, renal elimination of Ca2+ decreased significantly in both sgk1-/- and sgk1+ mice. The ability of the sgk1-/- mice to decrease urinary Ca2+ output again points to SGK1- independent regulation of renal tubular Ca2+ reabsorption. However, the decrease of absolute and fractional excretion upon exposure to the Ca2+-deficient diet was blunted in the sgk1-/- mice. Replacement of tap water in the drinking bottle with 1% saline led to the expected increase in urinary Na+ output, paralleled by a moderate increase in urinary Ca2+ output, but the urinary excretion of Ca2+ remained slightly lower in sgk1-/-than in sgk1+/+ mice. To explore the sensitivity of renal Ca2+ excretion to inhibition of Na+ reabsorption, the NKCC2 inhibitor furosemide (20 µg/g bw) was applied with or without the carboanhydrase inhibitor acetazolamide (50 µg/g bw). Furosemide alone increased renal Ca2+ excretion in sgk1-/- and sgk1+/+ mice and abolished the difference of Ca2+ excretion between genotypes. The additional administration of acetazolamide did not further increase natriuresis or calciuria. SGK1 knockout mice are anticalciuric presumably due to a decrease in extracellular volume and enhancement of Na+ and Ca2+ reabsorption upstream of the aldosterone-sensitive distal nephron including the loop of Henle. To study the role of SGK1 in renal fibrosis, sgk1-/- and their wild-type littermates sgk1+/+ were implanted with desoxycorticosterone acetate (DOCA)-release pellets and offered 1% saline as drinking water for 12 weeks. Treatment with DOCA/high salt led to a marked increase of fluid and Na+ intake in both genotypes. Three weeks after the initiation of DOCA/high salt treatment, the fluid intake increased by 3 fold in sgk1-/- mice, and by 11 fold in sgk1+/+ mice increasing even more during the whole study. After 12 weeks of treatment, body weight increased significantly (p<0.05) more in sgk1+/+ mice than in sgk1-/- mice and the urinary volume augmented significantly by 25 fold in sgk1+/+ mice and 4 fold in sgk1-/- mice with further increase until 12 weeks. Urinary albumin excretion was markedly increased following treatment of sgk1+/+ mice with DOCA/high salt, the increase was almost absent in sgk1-/- mice. Histological analysis revealed a marked influence of treatment on the morphology of kidneys from sgk1+/+ mice. The treatment was followed by marked glomerular enlargement with segmental glomerulosclerosis and tubulointerstitial fibrosis in sgk1+/+ mice, effects clearly blunted in sgk1-/- mice. In conclusion, SGK1 is required for the development of severe albuminuria following DOCA/high salt treatment whereas lack of SGK1 protects against DOCA/high-salt-induced albuminuria and renal fibrosis. To study the possibility that SGK1 and SGK3 could mutually replace each other, thus preventing severe NaCl loss in sgk1-/- and sgk3-/- mice, double knock-out mutants (sgk1-/-/sgk3-/-) were compared with their wildtype littermates (sgk1+/+/sgk3+/+). The sgk1-/-/sgk3-/- mice share the delayed hair growth with sgk3-/- mice and the modestly impaired renal salt retention with sgk1-/- mice. Plasma aldosterone concentrations were significantly (p <0.01) higher in sgk1-/-/sgk3-/- than in sgk1+/+/sgk3+/+ mice fed control and low-salt diets. During salt depletion, absolute and fractional excretions of Na+ were significantly higher in sgk1-/-/sgk3-/- than in sgk1+/+/sgk3+/+ mice. The fractional Na+ excretion was significantly decreased by low salt diet in both sgk1+/+/sgk3+/+ mice and sgk1-/-/sgk3-/-mice. Fluid intake in sgk1-/-/sgk3-/- mice similarly tended to increase following salt deficient diet and tended to be larger in sgk1-/-/sgk3-/- than in sgk1+/+/sgk3+/+ mice. Plasma K+ concentration tended to augment upon treatment with low salt diet and tended to be higher in sgk1+/+/sgk3+/+ than in sgk1-/-/sgk3-/- mice. Under low salt diet urinary sodium excretion decreased significantly in both sgk1+/+/sgk3+/+ mice and sgk1-/-/sgk3-/- mice. Under control diet blood pressure was significantly lower in sgk1-/-/sgk3-/- than in sgk1+/+/sgk3+/+ mice. Under both low and high salt diet blood pressure remained significantly lower in sgk1-/-/sgk3-/-than in sgk1+/+/sgk3+/+ mice

Thermal Conductivity Measurements with Galvanic Metallization Lines on Porosified LTCC Applying the 3-Omega Technique

AbstractThe reduction of the thermal conductivity of low temperature co-fired ceramics (LTCC) caused by a porosification process originally developed for the local modification of the permittivity is determined by the 3ω measurement technique. Therefore, metallization lines of small width down to 20μm are applied by galvanic pulse plating onto the roughened LTCC surface. By this deposition technology it is possible, to cover the pores without any depth penetration. Compared to the ‘as fired’ state, a reduction in thermal conductivity of up to 70% is measured independent of the LTCC type

First-in-Human Hyperpolarized MRI for Tumor Metabolism in HNSCC

This case report describes the use of hyperpolarized magnetic resonance imaging (MRI) in a patient with head and neck squamous cell carcinoma (HNSCC) to demonstrate its translational viability

Laparoscopic Splenectomy in Children

BACKGROUND: Laparoscopic splenectomy is being performed more commonly in children, although its advantages are not clear. We sought to determine whether laparoscopic splenectomy was superior to open splenectomy. METHODS: The records of all pediatric patients undergoing splenectomy without significant comorbidities over a 12-year period were examined. The patients were divided into those undergoing laparoscopic splenectomy and those undergoing open splenectomy. Demographics, operative time, estimated blood loss, spleen size, length of stay, and total charges were compared between the groups. RESULTS: Eighty-one (58%) children underwent laparoscopic splenectomy, and 59 (42%) children underwent open splenectomy. The groups were similar in age and sex; hereditary spherocytosis was more common in the LS group. Operating time was longer in the laparoscopic splenectomy group (231 +/- 10 min vs 138 +/- 9 min; P\u3c0.001), but blood loss and complication rates were similar. Twelve (15%) conversions were necessary primarily due to spleen size. Although children undergoing LS had a shorter length of stay (2.4 +/- 0.1 vs 4.1 +/- 0.3 days; P\u3c0.001), they incurred higher charges (dollars 21199 +/- 664 vs dollars 15723 +/- 1737; P\u3c0.002). CONCLUSION: Laparoscopic splenectomy is a safe procedure in children, resulting in shorter hospital stay, which may translate into earlier return to activity and a smaller burden on the child\u27s caretakers

Metabolic targeting, immunotherapy and radiation in locally advanced non-small cell lung cancer: Where do we go from here?

In the US, there are ~250,000 new lung cancer diagnoses and ~130,000 deaths per year, and worldwide there are an estimated 1.6 million deaths per year from this deadly disease. Lung cancer is the most common cause of cancer death worldwide, and it accounts for roughly a quarter of all cancer deaths in the US. Non-small cell lung cancer (NSCLC) represents 80-85% of these cases. Due to an enormous tobacco cessation effort, NSCLC rates in the US are decreasing, and the implementation of lung cancer screening guidelines and other programs have resulted in a higher percentage of patients presenting with potentially curable locoregional disease, instead of distant disease. Exciting developments in molecular targeted therapy and immunotherapy have resulted in dramatic improvement in patients’ survival, in combination with new surgical, pathological, radiographical, and radiation techniques. Concurrent platinum-based doublet chemoradiation therapy followed by immunotherapy has set the benchmark for survival in these patients. However, despite these advances, ~50% of patients diagnosed with locally advanced NSCLC (LA-NSCLC) survive long-term. In patients with local and/or locoregional disease, chemoradiation is a critical component of curative therapy. However, there remains a significant clinical gap in improving the efficacy of this combined therapy, and the development of non-overlapping treatment approaches to improve treatment outcomes is needed. One potential promising avenue of research is targeting cancer metabolism. In this review, we will initially provide a brief general overview of tumor metabolism as it relates to therapeutic targeting. We will then focus on the intersection of metabolism on both oxidative stress and anti-tumor immunity. This will be followed by discussion of both tumor- and patient-specific opportunities for metabolic targeting in NSCLC. We will then conclude with a discussion of additional agents currently in development that may be advantageous to combine with chemo-immuno-radiation in NSCLC

Early Detection of Mandible Osteoradionecrosis Risk in a High Comorbidity Veteran Population

OBJECTIVE: Osteoradionecrosis (ORN) of the mandible is a devastating complication of external beam radiation therapy (EBRT) for head and neck squamous cell carcinoma (HNSCC). We sought to ascertain ORN risk in a Veteran HNSCC population treatment with definitive or adjuvant EBRT and followed prospectively. STUDY DESIGN: Retrospective analysis of prospective cohort. SETTING: Tertiary care Veterans Health Administration (VHA) medical center. METHODS: Patients with HNSCC who initiated treatment at the Michael E. DeBakey Veterans Affairs Medical Center (MEDVAMC) are prospectively tracked for quality of care purposes through the end of the cancer surveillance period (5 years post treatment completion). We retrospectively analyzed this patient cohort and extracted clinical and pathologic data for 164 patients with SCC of the oral cavity, oropharynx, larynx, and hypopharynx who received definitive or adjuvant EBRT (2016-2020). RESULTS: Most patients were dentate and 80 % underwent dental extractions prior to EBRT of which 16 (16 %) had complications. The rate of ORN was 3.7 % for oral cavity SCC patients and 8.1 % for oropharyngeal SCC patients. Median time to ORN development was 156 days and the earliest case was detected at 127 days post EBRT completion. All ORN patients were dentate and underwent extraction prior to EBRT start. CONCLUSION: ORN development can occur early following EBRT in a Veteran population with significant comorbid conditions but overall rates are in line with the general population. Prospective tracking of HNSCC patients throughout the post-treatment surveillance period is critical to early detection of this devastating EBRT complication