416 research outputs found
Early pH Changes in Musculoskeletal Tissues upon Injury-Aerobic Catabolic Pathway Activity Linked to Inter-Individual Differences in Local pH
Local pH is stated to acidify after bone fracture. However, the time course and degree of acidification remain unknown. Whether the acidification pattern within a fracture hematoma is applicable to adjacent muscle hematoma or is exclusive to this regenerative tissue has not been studied to date. Thus, in this study, we aimed to unravel the extent and pattern of acidification in vivo during the early phase post musculoskeletal injury. Local pH changes after fracture and muscle trauma were measured simultaneously in two pre-clinical animal models (sheep/rats) immediately after and up to 48 h post injury. The rat fracture hematoma was further analyzed histologically and metabolomically. In vivo pH measurements in bone and muscle hematoma revealed a local acidification in both animal models, yielding mean pH values in rats of 6.69 and 6.89, with pronounced intra- and inter-individual differences. The metabolomic analysis of the hematomas indicated a link between reduction in tricarboxylic acid cycle activity and pH, thus, metabolic activity within the injured tissues could be causative for the different pH values. The significant acidification within the early musculoskeletal hematoma could enable the employment of the pH for novel, sought-after treatments that allow for spatially and temporally controlled drug release
The specialist in regeneration—the Axolotl—a suitable model to study bone healing?
While the axolotl's ability to completely regenerate amputated limbs is well known and studied, the mechanism of axolotl bone fracture healing remains poorly understood. One reason might be the lack of a standardized fracture fixation in axolotl. We present a surgical technique to stabilize the osteotomized axolotl femur with a fixator plate and compare it to a non-stabilized osteotomy and to limb amputation. The healing outcome was evaluated 3 weeks, 3, 6 and 9 months post-surgery by microcomputer tomography, histology and immunohistochemistry. Plate-fixated femurs regained bone integrity more efficiently in comparison to the non-fixated osteotomized bone, where larger callus formed, possibly to compensate for the bone fragment misalignment. The healing of a non-critical osteotomy in axolotl was incomplete after 9 months, while amputated limbs efficiently restored bone length and structure. In axolotl amputated limbs, plate-fixated and non-fixated fractures, we observed accumulation of PCNA(+) proliferating cells at 3 weeks post-injury similar to mouse. Additionally, as in mouse, SOX9-expressing cells appeared in the early phase of fracture healing and amputated limb regeneration in axolotl, preceding cartilage formation. This implicates endochondral ossification to be the probable mechanism of bone healing in axolotls. Altogether, the surgery with a standardized fixation technique demonstrated here allows for controlled axolotl bone healing experiments, facilitating their comparison to mammals (mice)
Radiation-Induced Graft Immobilization (RIGI): Covalent Binding of Non-Vinyl Compounds on Polymer Membranes
Radiation-induced graft immobilization (RIGI) is a novel method for the covalent binding of substances on polymeric materials without the use of additional chemicals. In contrast to the well-known radiation-induced graft polymerization (RIGP), RIGI can use non-vinyl compounds such as small and large functional molecules, hydrophilic polymers, or even enzymes. In a one-step electron-beam-based process, immobilization can be performed in a clean, fast, and continuous operation mode, as required for industrial applications. This study proposes a reaction mechanism using polyvinylidene fluoride (PVDF) and two small model molecules, glycine and taurine, in aqueous solution. Covalent coupling of single molecules is achieved by radical recombination and alkene addition reactions, with water radiolysis playing a crucial role in the formation of reactive solute species. Hydroxyl radicals contribute mainly to the immobilization, while solvated electrons and hydrogen radicals play a minor role. Release of fluoride is mainly induced by direct ionization of the polymer and supported by water. Hydrophobic chains attached to cations appear to enhance the covalent attachment of solutes to the polymer surface. Computational work is complemented by experimental studies, including X-ray photoelectron spectroscopy (XPS) and fluoride high-performance ion chromatography (HPIC)
Bullous pemphigoid in infants: characteristics, diagnosis and treatment
BACKGROUND: Bullous pemphigoid (BP) in infants is a rare but increasingly reported autoimmune blistering skin disease. Autoantibody reactivity is usually poorly characterized. Current guidelines do not address specific aspects of the infantile form of BP. The objectives of this study are to define clinical and diagnostic characteristics of infantile BP and develop a treatment algorithm. METHODS: Detailed characterization of a current case series of five infants with BP from our departments. Comprehensive analysis of all reported cases (1-12 months) with respect to clinical and laboratory characteristics, treatment and outcome. RESULTS: In total 81 cases were identified (including our own). The mean age was 4.5Â months. Moderately severe and severe disease was seen in 84% of cases. Involvement of hands and feet was present in all cases. Immunofluorescence microscopy was comparable with BP in adults. Where analyzed, the NC16A domain of bullous pemphigoid 180Â kDa antigen/collagen XVII (BP180) was identified as the major target antigen. BP180 NC16A ELISA values in our cohort were significantly higher than in a control cohort of 28 newly diagnosed adult patients. 50% of patients were treated with systemic corticosteroids, 20% with a combination of systemic corticosteroids and dapsone or sulfapyridine and 10% with topical corticosteroids alone. 14% of patients needed a combination of multiple immunosuppressants. All but one patient reached remission. Relapses were rare. CONCLUSIONS: Presentation of infantile BP is often severe with blistering of hands and feet present in all cases. Pathogenesis and diagnostic criteria are comparable to adult BP, yet BP180 NC16A ELISA levels seem to be significantly higher in infants. The overall disease outcome is favorable. Based on the results of this study we propose a treatment algorithm for infantile BP
Combination of organic acids benzoate, butyrate, caprylate, and sorbate provides a novel antibiotics-independent treatment option in the combat of acute campylobacteriosis
Introduction: The food-borne Gram-negative bacterial pathogen Campylobacter jejuni may cause the acute enterocolitis syndrome campylobacteriosis in infected humans. Given that human C. jejuni infections are rising globally which hold also true for resistance rates against antibiotic compounds such as macrolides and fluoroquinolones frequently prescribed for the treatment of severe infectious enteritis, novel antibiotics-independent therapeutic strategies are needed. Distinct organic acids are well known for their health-beneficial including anti-microbial and immunomodulatory properties. In our present study, we investigated potential pathogen-lowering and anti-inflammatory effects of benzoic acid, butyric acid, caprylic acid, and sorbic acid either alone or in combination during acute murine campylobacteriosis.
Methods: Therefore, secondary abiotic IL-10(-/-) mice were perorally infected with C. jejuni strain 81-176 and subjected to a 4-day-course of respective organic acid treatment.
Results and discussion: On day 6 post-infection, mice from the combination cohort displayed slightly lower pathogen loads in the duodenum, but neither in the stomach, ileum nor large intestine. Remarkably, the clinical outcome of C. jejuni induced acute enterocolitis was significantly improved after combined organic acid treatment when compared to the placebo control group. In support, the combinatory organic acid treatment dampened both, macroscopic and microscopic inflammatory sequelae of C. jejuni infection as indicated by less colonic shrinkage and less pronounced histopathological including apoptotic epithelial cell changes in the colon on day 6 post-infection. Furthermore, mice from the combination as compared to placebo cohort exhibited lower numbers of innate and adaptive immune cells such as neutrophilic granulocytes, macrophages, monocytes, and T lymphocytes in their colonic mucosa and lamina propria, respectively, which also held true for pro-inflammatory cytokine secretion in the large intestines and mesenteric lymph nodes. Notably, the anti-inflammatory effects were not restricted to the intestinal tract, but could also be observed systemically given pro-inflammatory mediator concentrations in C. jejuni infected mice from the combination organic acid treatment that were comparable to basal values. In conclusion, our in vivo study provides first evidence that an oral application of distinct organic acids in combination exhibits pronounced anti-inflammatory effects and hence, constitutes a promising novel antibiotics-independent therapeutic strategy in the combat of acute campylobacteriosis
The impact of menstruation persistence or recovery after chemotherapy on survival in young patients with hormone receptor negative breast cancer
Introduction: Hormone replacement therapy can diminish hormone depletion-related complaints in
postmenopausal women, but is contraindicated for postmenopausal breast cancer (BC) patients. Recovery of menstruation after chemotherapy-induced amenorrhea in young hormone receptor-negative
BC patients however, is accepted. To determine the safety of this strategy, we investigated the effect of
recovery of menstruation on disease-free survival (DFS) and overall survival (OS) in young hormone
receptor-negative BC patients treated with (neo)adjuvant chemotherapy.
Methods: We selected 636 patients from a single-center cohort with early stage hormone receptornegative BC and under the age of 50 years when treated with chemotherapy. Sufficient data on course
of menstruation in medical records was retrospectively found for 397 patients, of whom 299 patients
(75%) had a recovery of menstruation after chemotherapy. We used Cox proportional hazards models to
estimate hazard ratios (HR) for the effect of recovery of menstruation on DFS and OS.
Results: Patients with recovery of menstruation after chemotherapy less frequ
Reactions of pyrrole, imidazole, and pyrazole with ozone:Kinetics and mechanisms
Five-membered nitrogen-containing heterocyclic compounds (azoles) belong to potential moieties in complex structures where transformations during ozonation can occur. This study focused on the azole-ozone chemistry of pyrrole, imidazole, and pyrazole as model compounds. Reaction kinetics and ozonation products were determined by kinetic and analytical methods including NMR, LC-HRMS/MS, HPLC-UV, and IC-MS. Analyses of reactive oxygen species (O-1(2), & x2d9;OH, H2O2), quantum chemical computations (Gibbs energies), and kinetic simulations were used to further support the proposed reaction mechanisms. The species-specific second-order rate constants for the reactions of ozone with pyrrole and imidazole were (1.4 +/- 1.1) x 10(6) M-1 s(-1) and (2.3 +/- 0.1) x 10(5) M-1 s(-1), respectively. Pyrazole reacted more slowly with ozone at pH 7 (k(app) = (5.6 +/- 0.9) x 10(1) M-1 s(-1)). Maleimide was an identified product of pyrrole with a 34% yield. Together with other products, formate, formamide, and glyoxal, C and N mass balances of similar to 50% were achieved. Imidazole reacted with ozone to cyanate, formamide, and formate (similar to 100% yields per transformed imidazole, respectively) with a closed mass balance. For pyrazole, a high ozone : pyrazole molar stoichiometry of 4.6 was found, suggesting that the transformation products contributed to the over-stoichiometric consumption of ozone (e.g., hydroxypyrazoles). Glyoxal and formate were the only identified transformation products (C mass balance of 65%). Overall, the identified major products are suspected to hydrolyze and/or be biodegraded and thereby abated by a biological post-treatment typically following ozonation. However, as substructures of more complex compounds (e.g., micropollutants), they might be more persistent during biological post-treatment
Early pH changes in musculoskeletal tissues upon injury-aerobic catabolic pathway activity linked to inter-individual differences in local pH
Local pH is stated to acidify after bone fracture. However, the time course and degree of acidification remain unknown. Whether the acidification pattern within a fracture hematoma is applicable to adjacent muscle hematoma or is exclusive to this regenerative tissue has not been studied to date. Thus, in this study, we aimed to unravel the extent and pattern of acidification in vivo during the early phase post musculoskeletal injury. Local pH changes after fracture and muscle trauma were measured simultaneously in two pre-clinical animal models (sheep/rats) immediately after and up to 48 h post injury. The rat fracture hematoma was further analyzed histologically and metabolomically. In vivo pH measurements in bone and muscle hematoma revealed a local acidification in both animal models, yielding mean pH values in rats of 6.69 and 6.89, with pronounced intra- and inter-individual differences. The metabolomic analysis of the hematomas indicated a link between reduction in tricarboxylic acid cycle activity and pH, thus, metabolic activity within the injured tissues could be causative for the different pH values. The significant acidification within the early musculoskeletal hematoma could enable the employment of the pH for novel, sought-after treatments that allow for spatially and temporally controlled drug release
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