Abstract Plasmonic photothermal therapy (PPTT) is a promising cancer treatment where plasmonic nanoparticles are used to convert near infrared light to localized heat to cause cell death, mainly via ...apoptosis and necrosis. Modulating PPTT to induce cell apoptosis is more favorable than necrosis. Herein, we used a mild treatment condition using gold nanorods (AuNRs) to trigger apoptosis and tested how different cell lines responded to it. Three different cancer cell lines of epithelial origin: HSC (oral), MCF-7 (breast) and Huh7.5 (liver) had comparable AuNRs uptake and were heated to same environmental temperature (under 50 °C). However, Huh7.5 cells displayed a significant increase in cell apoptosis after PPTT as compared to the other two cell lines. As HSP70 is known to increase cellular resistance to heat, we determined relative HSP70 levels in these cells and results indicated that Huh7.5 cells had ten-fold decreased levels of HSP70 as compared with HSC and MCF-7 cells. We then down-regulated HSP70 with a siRNA and observed that all three cell lines displayed significant reduction in viability and an increase in apoptosis after PPTT. As an enhancement to PPTT, we conjugated AuNRs with Quercetin, an inhibitor of HSP70 which displayed anti-cancer effects via apoptosis.
Photoreceptor loss causes irreversible blindness in many retinal diseases. Repair of such damage by cell transplantation is one of the most feasible types of central nervous system repair; ...photoreceptor degeneration initially leaves the inner retinal circuitry intact and new photoreceptors need only make single, short synaptic connections to contribute to the retinotopic map. So far, brain- and retina-derived stem cells transplanted into adult retina have shown little evidence of being able to integrate into the outer nuclear layer and differentiate into new photoreceptors. Furthermore, there has been no demonstration that transplanted cells form functional synaptic connections with other neurons in the recipient retina or restore visual function. This might be because the mature mammalian retina lacks the ability to accept and incorporate stem cells or to promote photoreceptor differentiation. We hypothesized that committed progenitor or precursor cells at later ontogenetic stages might have a higher probability of success upon transplantation. Here we show that donor cells can integrate into the adult or degenerating retina if they are taken from the developing retina at a time coincident with the peak of rod genesis. These transplanted cells integrate, differentiate into rod photoreceptors, form synaptic connections and improve visual function. Furthermore, we use genetically tagged post-mitotic rod precursors expressing the transcription factor Nrl (ref. 6) (neural retina leucine zipper) to show that successfully integrated rod photoreceptors are derived only from immature post-mitotic rod precursors and not from proliferating progenitor or stem cells. These findings define the ontogenetic stage of donor cells for successful rod photoreceptor transplantation.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Photoreceptor replacement by transplantation is proposed as a treatment for blindness. Transplantation of healthy photoreceptor precursor cells into diseased murine eyes leads to the presence of ...functional photoreceptors within host retinae that express an array of donor-specific proteins. The resulting improvement in visual function was understood to be due to donor cells integrating within host retinae. Here, however, we show that while integration occurs the majority of donor-reporter-labelled cells in the host arises as a result of material transfer between donor and host photoreceptors. Material transfer does not involve permanent donor-host nuclear or cell-cell fusion, or the uptake of free protein or nucleic acid from the extracellular environment. Instead, RNA and/or protein are exchanged between donor and host cells in vivo. These data require a re-evaluation of the mechanisms underlying rescue by photoreceptor transplantation and raise the possibility of material transfer as a strategy for the treatment of retinal disorders.
Cell transplantation is a potential strategy for treating blindness caused by the loss of photoreceptors. Although transplanted rod-precursor cells are able to migrate into the adult retina and ...differentiate to acquire the specialized morphological features of mature photoreceptor cells, the fundamental question remains whether transplantation of photoreceptor cells can actually improve vision. Here we provide evidence of functional rod-mediated vision after photoreceptor transplantation in adult Gnat1−/− mice, which lack rod function and are a model of congenital stationary night blindness. We show that transplanted rod precursors form classic triad synaptic connections with second-order bipolar and horizontal cells in the recipient retina. The newly integrated photoreceptor cells are light-responsive with dim-flash kinetics similar to adult wild-type photoreceptors. By using intrinsic imaging under scotopic conditions we demonstrate that visual signals generated by transplanted rods are projected to higher visual areas, including V1. Moreover, these cells are capable of driving optokinetic head tracking and visually guided behaviour in the Gnat1−/− mouse under scotopic conditions. Together, these results demonstrate the feasibility of photoreceptor transplantation as a therapeutic strategy for restoring vision after retinal degeneration.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We show that sex steroids protect the adult murine skeleton through a mechanism that is distinct from that used to preserve the mass and function of reproductive organs. The classical genotropic ...actions of sex steroid receptors are dispensable for their bone protective effects, but essential for their effects on reproductive tissues. A synthetic ligand (4-estren-3α, 17β-diol) that reproduces the nongenotropic effects of sex steroids, without affecting classical transcription, increases bone mass and strength in ovariectomized females above the level of the estrogen-replete state and is at least as effective as dihydrotestosterone in orchidectomized males, without affecting reproductive organs. Such ligands merit investigation as potential therapeutic alternatives to hormone replacement for osteoporosis of bone mass in both women and men.
Aims/hypothesis
Observational studies suggest that metformin may reduce cancer risk by approximately one-third. We examined cancer outcomes and all-cause mortality in published randomised controlled ...trials (RCTs).
Methods
RCTs comparing metformin with active glucose-lowering therapy or placebo/usual care, with minimum 500 participants and 1-year follow-up, were identified by systematic review. Data on cancer incidence and all-cause mortality were obtained from publications or by contacting investigators. For two trials, cancer incidence data were not available; cancer mortality was used as a surrogate. Summary RRs, 95% CIs and
I
2
statistics for heterogeneity were calculated by fixed effects meta-analysis.
Results
Of 4,039 abstracts identified, 94 publications described 14 eligible studies. RRs for cancer were available from 11 RCTs with 398 cancers during 51,681 person-years. RRs for all-cause mortality were available from 13 RCTs with 552 deaths during 66,447 person-years. Summary RRs for cancer outcomes in people randomised to metformin compared with any comparator were 1.02 (95% CI 0.82, 1.26) across all trials, 0.98 (95% CI 0.77, 1.23) in a subgroup analysis of active-comparator trials and 1.36 (95% CI 0.74, 2.49) in a subgroup analysis of placebo/usual care comparator trials. The summary RR for all-cause mortality was 0.94 (95% CI 0.79, 1.12) across all trials.
Conclusions/interpretation
Meta-analysis of currently available RCT data does not support the hypothesis that metformin lowers cancer risk by one-third. Eligible trials also showed no significant effect of metformin on all-cause mortality. However, limitations include heterogeneous comparator types, absent cancer data from two trials, and short follow-up, especially for mortality.
The increasing incidence of acute appendicitis in sub-Saharan Africa emphasizes the need for accurate and reliable diagnostic tools. However, the variability in the diagnostic performance of computed ...tomography for suspected acute appendicitis coupled with comparatively higher negative appendectomy rates in this setting highlight a possible concern regarding the diagnostic accuracy. A retrospective diagnostic accuracy study was conducted from July to October 2020. All patients above 14 years of age who presented at the emergency department with right iliac fossa abdominal pain of fewer than ten days and underwent computed tomography for suspected acute appendicitis were evaluated, and the Alvarado score was computed. Histological diagnosis and clinical follow-up of 14 days were considered the reference standard. Ethical clearance was sought from the Aga Khan University Ethical review committee. 176 patients were included in this study. The sensitivity, specificity, and diagnostic accuracy were 100% (95% CI 91.8-100), 96.9% (95% CI 92.2-99.1), and 96.9% (95% CI 93.1-98.3), respectively. The mean Alvarado score in those without acute appendicitis was 4 (95% CI 3.7-4.3) compared to a mean score of 6.6 (95% CI 6.0-7.2) amongst those with acute appendicitis. The area under the receiver operator characteristics curve of computed tomography was 98.4%, and that of the Alvarado score was 84.1%. The diagnostic performance of computed tomography in this study is similar to that established elsewhere. However, the Alvarado score is not routinely used for the initial screening of suspected acute appendicitis patients. A threshold of Alvarado score of 4 as a guide to conduct computed tomography for suspected acute appendicitis would have decreased computed tomography use by 50%, and missed 4 cases. Implementation studies that address Alvarado score use should be conducted.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Aims/hypothesis
This study reports the results of the first phase of a national study to determine the prevalence of diabetes and prediabetes (impaired fasting glucose and/or impaired glucose ...tolerance) in India.
Methods
A total of 363 primary sampling units (188 urban, 175 rural), in three states (Tamilnadu, Maharashtra and Jharkhand) and one union territory (Chandigarh) of India were sampled using a stratified multistage sampling design to survey individuals aged ≥20 years. The prevalence rates of diabetes and prediabetes were assessed by measurement of fasting and 2 h post glucose load capillary blood glucose.
Results
Of the 16,607 individuals selected for the study, 14,277 (86%) participated, of whom 13,055 gave blood samples. The weighted prevalence of diabetes (both known and newly diagnosed) was 10.4% in Tamilnadu, 8.4% in Maharashtra, 5.3% in Jharkhand, and 13.6% in Chandigarh. The prevalences of prediabetes (impaired fasting glucose and/or impaired glucose tolerance) were 8.3%, 12.8%, 8.1% and 14.6% respectively. Multiple logistic regression analysis showed that age, male sex, family history of diabetes, urban residence, abdominal obesity, generalised obesity, hypertension and income status were significantly associated with diabetes. Significant risk factors for prediabetes were age, family history of diabetes, abdominal obesity, hypertension and income status.
Conclusions/interpretations
We estimate that, in 2011, Maharashtra will have 6 million individuals with diabetes and 9.2 million with prediabetes, Tamilnadu will have 4.8 million with diabetes and 3.9 million with prediabetes, Jharkhand will have 0.96 million with diabetes and 1.5 million with prediabetes, and Chandigarh will have 0.12 million with diabetes and 0.13 million with prediabetes. Projections for the whole of India would be 62.4 million people with diabetes and 77.2 million people with prediabetes.
The development of new and improved photothermal contrast agents for the successful treatment of cancer (or other diseases) via plasmonic photothermal therapy (PPTT) is a crucial part of the ...application of nanotechnology in medicine. Gold nanorods (AuNRs) have been found to be the most effective photothermal contrast agents, both in vitro and in vivo. Therefore, determining the optimum AuNR size needed for applications in PPTT is of great interest. In the present work, we utilized theoretical calculations as well as experimental techniques in vitro to determine this optimum AuNR size by comparing plasmonic properties and the efficacy as photothermal contrast agents of three different sizes of AuNRs. Our theoretical calculations showed that the contribution of absorbance to the total extinction, the electric field, and the distance at which this field extends away from the nanoparticle surface all govern the effectiveness of the amount of heat these particles generate upon NIR laser irradiation. Comparing between three different AuNRs (38 × 11, 28 × 8, and 17 × 5 nm), we determined that the 28 × 8 nm AuNR is the most effective in plasmonic photothermal heat generation. These results encouraged us to carry out in vitro experiments to compare the PPTT efficacy of the different sized AuNRs. The 28 × 8 nm AuNR was found to be the most effective photothermal contrast agent for PPTT of human oral squamous cell carcinoma. This size AuNR has the best compromise between the total amount of light absorbed and the fraction of which is converted to heat. In addition, the distance at which the electric field extends from the particle surface is most ideal for this size AuNR, as it is sufficient to allow for coupling between the fields of adjacent particles in solution (i.e., particle aggregates), resulting in effective heating in solution.
Single-cell analyses have revealed extensive heterogeneity between and within human tumours
, but complex single-cell phenotypes and their spatial context are not at present reflected in the ...histological stratification that is the foundation of many clinical decisions. Here we use imaging mass cytometry
to simultaneously quantify 35 biomarkers, resulting in 720 high-dimensional pathology images of tumour tissue from 352 patients with breast cancer, with long-term survival data available for 281 patients. Spatially resolved, single-cell analysis identified the phenotypes of tumour and stromal single cells, their organization and their heterogeneity, and enabled the cellular architecture of breast cancer tissue to be characterized on the basis of cellular composition and tissue organization. Our analysis reveals multicellular features of the tumour microenvironment and novel subgroups of breast cancer that are associated with distinct clinical outcomes. Thus, spatially resolved, single-cell analysis can characterize intratumour phenotypic heterogeneity in a disease-relevant manner, with the potential to inform patient-specific diagnosis.
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