Excess reactive oxygen species production by mitochondria is a key mechanism of age-related vascular dysfunction. Our laboratory has shown that supplementation with the mitochondrial-targeted ...antioxidant MitoQ improves vascular endothelial function by reducing mitochondrial reactive oxygen species and ameliorates arterial stiffening in old mice, but the effects in humans are unknown. Here, we sought to translate our preclinical findings to humans and determine the safety and efficacy of MitoQ. Twenty healthy older adults (60-79 years) with impaired endothelial function (brachial artery flow-mediated dilation <6%) underwent 6 weeks of oral supplementation with MitoQ (20 mg/d) or placebo in a randomized, placebo-controlled, double-blind, crossover design study. MitoQ was well tolerated, and plasma MitoQ was higher after the treatment versus placebo period (
<0.05). Brachial artery flow-mediated dilation was 42% higher after MitoQ versus placebo (
<0.05); the improvement was associated with amelioration of mitochondrial reactive oxygen species-related suppression of endothelial function (assessed as the increase in flow-mediated dilation with acute, supratherapeutic MitoQ 160 mg administration; n=9;
<0.05). Aortic stiffness (carotid-femoral pulse wave velocity) was lower after MitoQ versus placebo (
<0.05) in participants with elevated baseline levels (carotid-femoral pulse wave velocity >7.60 m/s; n=11). Plasma oxidized LDL (low-density lipoprotein), a marker of oxidative stress, also was lower after MitoQ versus placebo (
<0.05). Participant characteristics, endothelium-independent dilation (sublingual nitroglycerin), and circulating markers of inflammation were not different (all
>0.1). These findings in humans extend earlier preclinical observations and suggest that MitoQ and other therapeutic strategies targeting mitochondrial reactive oxygen species may hold promise for treating age-related vascular dysfunction.
URL: http://www.clinicaltrials.gov. Unique identifier: NCT02597023.
Summary
Background
The epidermal barrier is important for water conservation, failure of which is evident in dry‐skin conditions. Barrier function is fulfilled by the stratum corneum, tight junctions ...(TJs, which control extracellular water) and keratinocyte mechanisms, such as organic osmolyte transport, which regulate intracellular water homeostasis. Organic osmolyte transport by keratinocytes is largely unexplored and nothing is known regarding how cellular and extracellular mechanisms of water conservation may interact.
Objectives
We aimed to characterize osmolyte transporters in skin and keratinocytes, and, using transporter inhibitors, to investigate whether osmolytes can modify TJs. Such modification would suggest a possible link between intracellular and extracellular mechanisms of water regulation in skin.
Methods
Immunostaining and quantitative polymerase chain reaction of organic osmolyte‐treated organ‐cultured skin were used to identify changes to organic osmolyte transporters, and TJ protein and gene expression. TJ functional assays were performed on organic osmolyte‐treated primary human keratinocytes in culture.
Results
Immunostaining demonstrated the expression of transporters for betaine, taurine and myo‐inositol in transporter‐specific patterns. Treatment of human skin with either betaine or taurine increased the expression of claudin‐1, claudin‐4 and occludin. Osmolyte transporter inhibition abolished this response. Betaine and taurine increased TJ function in primary human keratinocytes in vitro.
Conclusions
Treatment of skin with organic osmolytes modulates TJ structure and function, which could contribute to the epidermal barrier. This emphasizes a role for organic osmolytes beyond the maintenance of intracellular osmolarity. This could be harnessed to enhance topical therapies for diseases characterized by skin barrier dysfunction.
What is already known about this topic?
Limited studies have shown that organic osmolytes protect keratinocytes from stressors such as ultraviolet, but their transporters have never been shown in human skin.
What does this study add?
Human skin expresses the transporters for betaine, taurine and myo‐inositol and their expression is increased by the respective osmolytes.
We show that osmolytes increase tight junction protein expression in skin and tight junction function in keratinocytes by a variety of mechanisms.
What is the translational message?
Osmolytes can act as signalling molecules, which change essential components of the barrier.
This suggests that their inclusion in topical therapies might help improve the epidermal barrier in healthy skin and also in diseases where the barrier is dysfunctional.
Linked Comment: Benedetto. Br J Dermatol 2021; 184:388–389.
Plain language summary available online
Blood oxygen level dependent (BOLD) contrast pharmacological magnetic resonance imaging (phMRI) is an increasingly popular technique that allows the non-invasive investigation of spatial and temporal ...changes in rat brain function in response to pharmacological stimulation in vivo. Rat brain BOLD contrast phMRI is, at present, established in few neuropharmacological laboratories, and various issues associated with the technique require attention. The present review is primarily aimed at psychopharmacologists with no previous experience of phMRI, who are interested in the practical aspects that phMRI studies entail.
Experimental and analytical considerations, including anaesthesia, physiological monitoring, drug dose and delivery, scanning protocols, statistical approaches and the interpretation of phMRI data, are discussed.
Thalidomide is an anti-angiogenic agent currently used to treat patients with malignant cachexia or multiple myeloma. Lenalidomide (CC-5013) is an immunomodulatory thalidomide analogue licensed in ...the United States of America (USA) for the treatment of a subtype of myelodysplastic syndrome. This two-centre, open-label phase I study evaluated dose-limiting toxicities in 55 patients with malignant solid tumours refractory to standard chemotherapies. Lenalidomide capsules were consumed once daily for 12 weeks according to one of the following three schedules: (I) 25mg daily for the first 7 d, the daily dose increased by 25mg each week up to a maximum daily dose of 150mg; (II) 25mg daily for 21 d followed by a 7-d rest period, the 4-week cycle repeated for 3 cycles; (III) 10mg daily continuously. Twenty-six patients completed the study period. Two patients experienced a grade 3 hypersensitivity rash. Four patients in cohort I and 4 patients in cohort II suffered grade 3 or 4 neutropaenia. In 2 patients with predisposing medical factors, grade 3 cardiac dysrhythmia was recorded. Grade 1 neurotoxicity was detected in 6 patients. One complete and two partial radiological responses were measured by computed tomography scanning; 8 patients had stable disease after 12 weeks of treatment. Fifteen patients remained on treatment as named patients; 1 with metastatic melanoma remains in clinical remission 3.5 years from trial entry. This study indicates the tolerability and potential clinical efficacy of lenalidomide in patients with advanced solid tumours who have previously received multi-modality treatment. Depending on the extent of myelosuppressive pre-treatment, dose schedules (II) or (III) are advocated for large-scale trials of long-term administration.
Energy landscape theory is a powerful tool for understanding the structure and dynamics of complex molecular systems, in particular biological macromolecules. The primary sequence of a protein ...defines its free-energy landscape and thus determines the folding pathway and the rate constants of folding and unfolding, as well as the protein's native structure. Theory has shown that roughness in the energy landscape will lead to slower folding, but derivation of detailed experimental descriptions of this landscape is challenging. Simple folding models show that folding is significantly influenced by chain entropy; proteins in which the contacts are local fold quickly, owing to the low entropy cost of forming stabilizing, native contacts during folding. For some protein families, stability is also a determinant of folding rate constants. Where these simple metrics fail to predict folding behaviour, it is probable that there are features in the energy landscape that are unusual. Such general observations cannot explain the folding behaviour of the R15, R16 and R17 domains of -spectrin. R15 folds ∼3,000 times faster than its homologues, although they have similar structures, stabilities and, as far as can be determined, transition-state stabilities. Here we show that landscape roughness (internal friction) is responsible for the slower folding and unfolding of R16 and R17. We use chimaeric domains to demonstrate that this internal friction is a property of the core, and suggest that frustration in the landscape of the slow-folding spectrin domains may be due to misdocking of the long helices during folding. Theoretical studies have suggested that rugged landscapes will result in slower folding; here we show experimentally that such a phenomenon directly influences the folding kinetics of a 'normal' protein, that is, one with a significant energy barrier that folds on a relatively slow, millisecond-second, timescale.
We reviewed outcomes after allogeneic hematopoietic cell transplantation (HCT) in 35 children with Chediak-Higashi syndrome (CHS). Twenty-two patients had a history of the life-threatening ...accelerated phase of CHS before HCT and 11 were in accelerated phase at transplantation. Thirteen patients received their allograft from an human leukocyte antigen (HLA)-matched sibling, 10 from an alternative related donor and 12 from an unrelated donor. Eleven recipients of HLA-matched sibling donor, three recipients of alternative related donor and eight recipients of unrelated donor HCT are alive. With a median follow-up of 6.5 years, the 5-year probability of overall survival is 62%. Mortality was highest in those with accelerated phase disease at transplantation and after alternative related donor HCT. Only four of 11 patients with active disease at transplantation are alive. Seven recipients of alternative related donor HCT had active disease at transplantation and this may have influenced the poor outcome in this group. Although numbers are limited, HCT appears to be effective therapy for correcting and preventing hematologic and immunologic complications of CHS, and an unrelated donor may be a suitable alternative for patients without an HLA-matched sibling. Early referral and transplantation in remission after accelerated phase disease may improve disease-free survival.
TEMS: results of a specialist centre Flexer, S. M.; Durham-Hall, A. C.; Steward, M. A. ...
Surgical endoscopy,
06/2014, Letnik:
28, Številka:
6
Journal Article
Recenzirano
Introduction
Transanal endoscopic microsurgery (TEMS) is becoming more widespread due to the increasing body of evidence to support its role. Previous published data has reported recurrence rates in ...excess of 10 % for benign polyps after TEMS.
Methods
Bradford Royal Infirmary is a tertiary referral centre for TEMS and early rectal cancer in the UK. Data for all TEMS operations were entered into a prospective database over a 7-year period. Demographic data, complications and recurrence rates were recorded. Both benign adenomas and malignant lesions were included.
Results
A total of 164 patients (65 % male), with a mean age of 68 years were included; 114 (70 %) of the lesions resected were benign adenomas, and 50 (30 %) were malignant lesions. Median polyp size was 4 (range 0.6–14.5) cm. Mean length of operation was 55 (range 10–120) min. There were no recurrences in any patients with a benign adenoma resected; two patients with malignant lesions developed recurrences. Three intra-operative complications were recorded, two rectal perforations (repaired primarily, one requiring defunctioning stoma), and a further patient suffered a blood loss of >300 ml requiring transfusion. Six patients developed strictures requiring dilation either endoscopically or under anaesthetic in the post-operative period.
Conclusions
We have demonstrated that TEMS procedures performed in a specialist centre provide low rates of both recurrence and complication. Within a specialist centre, TEMS surgery should be offered to all patients for rectal lesions, both benign and malignant, that are amenable to TEMS.
AIMS: To estimate the prevalence of β-haemolytic Lancefield group C streptococci in healthy dogs, cats and horses; to determine if frequent contact with horses was associated with isolation of these ...species from dogs and cats; and to characterise recovered S. equi subsp. zooepidemicus isolates by multilocus sequence typing. METHODS: Oropharyngeal swabs were collected from 197 dogs and 72 cats, and nasopharyngeal swabs from 93 horses. Sampling was carried out at the Massey University Veterinary Teaching Hospital, on sheep and beef farms or on premises where horses were present. All animals were healthy and were categorised as Urban dogs and cats (minimal contact with horses or farm livestock), Farm dogs (minimal contact with horses) and Stable dogs and cats (frequent contact with horses). Swabs were cultured for β-haemolytic Streptococcus spp. and Lancefield group C streptococcal subspecies were confirmed by phenotypic and molecular techniques. RESULTS: Of the 197 dogs sampled, 21 (10.7 (95% CI= 4.0–25.4)%) tested positive for S. dysgalactiae subsp. equisimilis and 4 (2.0 (95% CI=0.7–5.5)%) tested positive for S. equi subsp. zooepidemicus. All these isolates, except for one S. dysgalactiae subsp. equisimilis isolate in an Urban dog, were from Stable dogs. S. dysgalactiae subsp. equisimilis was isolated from one Stable cat. Of the 93 horses, 22 (23.7 (95% CI=12.3–40.6)%) and 6 (6.5 (95% CI=2.8–14.1)%) had confirmed S. dysgalactiae subsp. equisimilis and S. equi subsp. zooepidemicus isolation respectively. Isolation of S. dysgalactiae subsp. equisimilis from dogs was associated with frequent contact with horses (OR=9.8 (95% CI=2.6–72.8)). Three different multilocus sequence type profiles of S. equi subsp. zooepidemicus that have not been previously reported in dogs were recovered. CONCLUSIONS AND CLINICAL RELEVANCE: Subclinical infection or colonisation by S. equi subsp. zooepidemicus and S. dysgalactiae subsp. equisimilis occurs in dogs and further research on inter-species transmission and the pathogenic potential of these Lancefield group C streptococci is needed. Complete speciation of β-haemolytic streptococci should be recommended in clinical cases and the possible exposure to horses and their environment should be considered in epidemiological investigations.
Reduced-intensity/reduced-toxicity conditioning and allogeneic T-cell replete hematopoietic stem cell transplantation are curative in patients with hemophagocytic lymphohistiocytosis (HLH). Unstable ...donor chimerism (DC) and relapses are clinical challenges . We examined the effect of a reduced-intensity conditioning regimen based on targeted busulfan to enhance myeloid DC in HLH. The European Society for Bone and Marrow Transplantation–approved reduced-intensity conditioning protocol comprised targeted submyeloablative IV busulfan, IV fludarabine, and serotherapy comprising IV alemtuzumab (0.5-0.8 mg/kg) for unrelated-donor and IV rabbit anti–T-cell globulin for related-donor transplants. We assessed toxicity, engraftment, graft-versus-host disease (GHVD), DC in blood cell subtypes, and overall survival/event-free survival. Twenty-five patients from 7 centers were treated (median age, 0.68 year). The median total dose and cumulative area under the curve of busulfan was 13.1 mg/kg (6.4-26.4) and 63.1 mg/L × h (48-77), respectively. Bone marrow, peripheral blood stem cell, or cord blood transplants from HLA-matched related (n = 7) or unrelated (n = 18) donors were administered. Donor cells engrafted in all patients (median: neutrophils d+20/platelets d+28). At last follow-up (median, 36 months; range, 8-111 months), the median DC of CD15+ neutrophils, CD3+ T cells, and CD16+56+ natural killer cells was 99.5% (10-100), 97% (30-100), and 97.5% (30-100), respectively. Eight patients (32%) developed sinusoidal obstruction syndrome, resolving after defibrotide treatment. The 3-year overall survival and event-free survival rates were both 100%. None of the patients developed acute grade III to IV GHVD. Limited chronic GVHD was encountered in 4%. This regimen achieves excellent results with stable DC in patients with HLH.
•Targeted busulfan, fludarabine, serotherapy, and HLA-matched hematopoietic stem cell transplantation achieved 100% event-free survival in HLH.•After a median follow-up of 3 years, satisfactory DC on myeloid and T cells, no graft failures, and a low rate of chronic GHVD were observed.
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Chromosome 6 is a metacentric chromosome that constitutes about 6% of the human genome. The finished sequence comprises 166,880,988 base pairs, representing the largest chromosome sequenced so far. ...The entire sequence has been subjected to high-quality manual annotation, resulting in the evidence-supported identification of 1,557 genes and 633 pseudogenes. Here we report that at least 96% of the protein-coding genes have been identified, as assessed by multi-species comparative sequence analysis, and provide evidence for the presence of further, otherwise unsupported exons/genes. Among these are genes directly implicated in cancer, schizophrenia, autoimmunity and many other diseases. Chromosome 6 harbours the largest transfer RNA gene cluster in the genome; we show that this cluster co-localizes with a region of high transcriptional activity. Within the essential immune loci of the major histocompatibility complex, we find HLA-B to be the most polymorphic gene on chromosome 6 and in the human genome.
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