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von Willebrand factor (VWF) is a multimeric blood protein that acts as a mechanical probe, responding to changes in flow to initiate platelet plug formation. Previously, our laboratory tests had shown that using single-molecule imaging that shear stress can extend surface-tethered VWF, but paradoxically, we found that the required shear stress was higher than reported for free-in-flow VWF, an observation inconsistent with basic physical principles. To resolve this inconsistency critical to VWF’s molecular mechanism, we measured free-VWF extension in shear flow using pulsed laser stroboscopic imaging of single molecules. Here, laser pulses of different durations are used to capture multiple images of the same molecule within each frame, enabling accurate length measurements in the presence of motion blur. At high shear stresses, we observed a mean shift in VWF extension of

Multiple-strain (polygenomic) infections are a ubiquitous feature of Plasmodium falciparum parasite population genetics. Under simple assumptions of superinfection, polygenomic infections are hypothesized to be the result of multiple infectious bites. As a result, polygenomic infections have been used as evidence of repeat exposure and used to derive genetic metrics associated with high transmission intensity. However, not all polygenomic infections are the result of multiple infectious bites. Some result from the transmission of multiple, genetically related strains during a single infectious bite (cotransmission). Superinfection and cotransmission represent two distinct transmission processes, and distinguishing between the two could improve inferences regarding parasite transmission intensity. Here, we describe a new metric, RH, that utilizes the correlation in allelic state (heterozygosity) within polygenomic infections to estimate the likelihood that the observed complexity resulted from either superinfection or cotransmission. RH is flexible and can be applied to any type of genetic data. As a proof of concept, we used RH to quantify polygenomic relatedness and estimate cotransmission and superinfection rates from a set of 1,758 malaria infections genotyped with a 24 single nucleotide polymorphism (SNP) molecular barcode. Contrary to expectation, we found that cotransmission was responsible for a significant fraction of 43% to 53% of the polygenomic infections collected in three distinct epidemiological regions in Senegal. The prediction that polygenomic infections frequently result from cotransmission stresses the need to incorporate estimates of relatedness within polygenomic infections to ensure the accuracy of genomic epidemiology surveillance data for informing public health activities.

Targeted protein degraders (TPDs) have expanded the breadth of therapeutic options through both their catalytic mechanism of action and ability to degrade previously “undruggable” target proteins. Prior reports of small-molecule GSPT1 degraders such as CC-90009 in AML demonstrate potent anti-tumor cytotoxicity, but with a potentially narrow therapeutic index. To increase the efficacy vs. tolerability window of TPDs and improve drug delivery, we introduce TPD-Squared (TPD2 TM), a dual-targeted protein degradation approach of combining the catalytic mechanism of targeted protein degradation with the precision of tumor-targeting therapeutic antibodies. We have previously shown in vitro and in vivo efficacy with a HER2-targeted TPD2 conjugate: ORM-5029. Following on that success, we generated conjugates using a CD33-targeting antibody (OR000283) produced by engineering the FAb (H&L) sequences from gemtuzumab onto an IgG1 Fc with N297A variant to inhibit Fc-γR binding. Medicinal chemistry optimization of linker-payloads led to the identification of ORM-6151, which is composed of SMol006, a highly potent GSPT1 degrader conjugated to OR000283 via a novel β-glucuronide releasable linker. ORM-6151 treatment in CD33-expressing cell lines showed picomolar activity with 10-1000-fold greater potency compared to several GSPT1 degrader molecules, including CC-90009 or Mylotarg, and had robust activity in Mylotarg-resistant lines (AML193 and Kasumi6). ORM-6151 also exhibited picomolar potency in in vitro cytotoxicity to primary relapsed/refractory AML patient blasts, with better potency than CC-90009 and Mylotarg. We evaluated ORM-6151 in several in vivo disseminated xenograft models and observed robust efficacy following a single treatment at doses as low as 0.1 mg/kg. Tumor growth inhibition correlated with the degree and duration of GSPT1 depletion and changes in the expression of previously described integrated stress response biomarker genes. In summary, ORM-6151 is a promising, potential therapy for AML and currently in preclinical development as a first-in-class targeted protein degrader therapy with CD33-targeted delivery. Citation Format: James Palacino, Pedro Lee, Hangyeol Jeong, Yeonjoon Kim, Yoojin Song, Uttapol Permpoon, Wesley Wong, Chen Bai, Nathan Fishkin, Khuloud Takouri, Eunjun Yu, Yong Yi, Anna Skaletskaya, Min-Soo Kim, Da-Yeong Kim, Dong-Ki Choi, Peter U. Park. ORM-6151: A first-in-class CD33-antibody enabled GSPT1 degrader for AML [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2700.

Obesity is linked with insulin resistance and is characterized by excessive accumulation of adipose tissue due to chronic energy imbalance. Increasing thermogenic brown and beige adipose tissue futile cycling may be an important strategy to increase energy expenditure in obesity, however, brown adipose tissue metabolic activity is lower with obesity. Herein, we report that the exposure of mice to thermoneutrality promotes the infiltration of white adipose tissue with mast cells that are highly enriched with tryptophan hydroxylase 1 (Tph1), the rate limiting enzyme regulating peripheral serotonin synthesis. Engraftment of mast cell-deficient mice with Tph1−/− mast cells or selective mast cell deletion of Tph1 enhances uncoupling protein 1 (Ucp1) expression in white adipose tissue and protects mice from developing obesity and insulin resistance. These data suggest that therapies aimed at inhibiting mast cell Tph1 may represent a therapeutic approach for the treatment of obesity and type 2 diabetes., Serotonin inhibits adipose tissue thermogenesis. Here the authors show that obese mice housed in thermoneutrality have increased mast cell serotonin synthesis, and that inhibiting this pathway through deletion of mast cell Tph1 increases white adipose tissue browning and protects against diet-induced obesity, insulin resistance and liver steatosis.

Photons emitted via bremsstrahlung are inherently incoherent and non-directional. We show that the intrinsic cross-section of bremsstrahlung from crystalline solids can be enhanced and made directional by shaping the quantum wave nature of free electrons.

Clinical laboratories usually have a quality management system such as ISO 15189, which provides a framework for quality and competence to perform medical testing and internal systems such as audit and nonconformance to ensure consistent processes. However, organizations need to have access to internal procedures and external competitors' performance to improve their operations. These are often seen as commercial or areas where it is difficult to agree on an acceptable goal.In 2019, 1158 laboratories from 17 countries/regions in the Asia Pacific Region answered the survey, including 399 Chinese sites. The survey collected information on quality, turnaround time and productivity.Median productivity for laboratories in the Asia Pacific Region not including Chinese sites was 25 samples/FTE/day for small laboratories (workload:250 samples/day), 100 for medium-sized laboratories (workload: 251-1000 samples/day) and 220 for large laboratories (workload:1001 samples/day). The parameters associated with increased productivity in some laboratories were automation, middleware, Lean Six Sigma quality improvement activities and International Accreditation.This survey provides evidence of an association of quality improvement activities on laboratory productivity. There are differences in the effect of these activities in Chinese and non-Chinese laboratories in the Asia Pacific Region. The survey confirmed that the implementation of automation is associated with increased median productivity in all sites. Implementation of Lean Six Sigma and International Accreditation is associated with increased productivity in large laboratories.

Neutrophils help to clear pathogens and cellular debris, but can also cause collateral damage within inflamed tissues. Prolonged neutrophil residency within an inflammatory niche can exacerbate tissue pathology. Using both genetic and pharmacological approaches, we show that BCL-XL is required for the persistence of neutrophils within inflammatory sites in mice. We demonstrate that a selective BCL-XL inhibitor (A-1331852) has therapeutic potential by causing apoptosis in inflammatory human neutrophils ex vivo. Moreover, in murine models of acute and chronic inflammatory disease, it reduced inflammatory neutrophil numbers and ameliorated tissue pathology. In contrast, there was minimal effect on circulating neutrophils. Thus, we show a differential survival requirement in activated neutrophils for BCL-XL and reveal a new therapeutic approach to neutrophil-mediated diseases.

Targeted protein degradation (TPD) molecules, including IMiD-based molecular glues and heterobifunctional degraders have expanded the breadth of therapeutic options through both their catalytic mechanism of action and ability to degrade previously “undruggable” target proteins. To increase the efficacy vs. tolerability window of protein degradation and improve drug delivery we combine the catalytic approach of targeted protein degradation with the precision of tumor targeting therapeutic antibodies. Here, we describe the development of ORM-5029, a highly potent and selective GSPT1 degrader targeting HER2-expressing tumor cells. We first screened a panel of cell lines to identify tumors where treatment with a selective, membrane-permeable, molecular glue (SMol007) would exhibit the most potent GSPT1 degradation, integrated stress response, and ultimately apoptosis. HER2+ breast cancer cell lines were more sensitive to GSPT1 degradation than the average IC50 for all cell lines tested. Several of our GSPT1 degrader molecules were tested in HER2-positive tumor models and displayed a consistent pattern of potent cytotoxicity. An unbiased global proteomics evaluation of changes in abundance identified SMol006 as a specific GSPT1 degrader, with no significant depletion of over 6500 other proteins detected. To evaluate whether antibody delivery could provide a potency increase of Smol006 and other GSTP1 degrader payloads, we conjugated these payloads to the HER2-targeting antibodies, trastuzumab and pertuzumab. Given the comparable activity of both antibodies and frequent use of trastuzumab as the antibody domain of several ADCs, we selected pertuzumab as our targeting antibody. Further medicinal chemistry optimization and evaluation of many linker-payloads led to the identification of our first preclinical AnDC candidate ORM-5029, which is composed of SMol006, a highly-potent GSPT1 degrader conjugated to pertuzumab via a clinically-validated Val-Cit PABc linker. ORM-5029 treatment in the HER2-expressing cell lines showed 10-1000 fold superiority in potency compared to SMol006, Kadcyla and/or Enhertu treatment. We evaluated ORM-5029 in several in vivo xenograft models and observed robust efficacy, following a single-dose treatment testing as low as 3 mg/kg. In the BT474 xenograft model, treatment with ORM-5029 demonstrated single-dose activity superior to Kadcyla, and comparable to Enhertu when given at an equivalent dose. In an HCC1569 xenograft model, tumor growth inhibition correlated with the degree and duration of GSPT1 depletion and changes in expression of previously described integrated stress response biomarker genes. ORM-5029 is currently in preclinical development as a potential first-in-class targeted protein degrader therapy with HER2-targeted delivery. Citation Format: James Palacino, Chen Bai, Yong Yi, Anna Skaletskaya, Khuloud Takrouri, Wesley Wong, Min-Soo Kim, Dong-Ki Choi, Da-Young Kim, Yeonhee Yang, Jiae Kook, Pedro Lee, Hangyeol Jeong, Sang-Mi Jee, Jiyun Park, Ki-Hwan Chang, Nathan Fishkin, Peter U. Park. ORM-5029: A first-in-class targeted protein degradation therapy using antibody neodegrader conjugate (AnDC) for HER2-expressing breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3933.

Background Reporting critical results in a timely manner is a crucial role of clinical laboratories. Traditionally, these results were reported using the phone or fax system. However, there are now other modes of communication for this reporting. Quality improvement in any organization is driven by detection of errors and benchmarking against peers. In the case of critical result reporting, there are few current widely used Benchmarking schemes. Methods The Roche Clinical Chemistry Benchmarking Survey in 2019 added questions about critical result reporting including the mode of communication and turnaround time key performance index. This survey includes over 1100 laboratories from 20 countries. Results The survey revealed a range of communication strategies with phone calls still the commonest followed by email. The key performance index for most laboratories was less than 10 min. Conclusion Benchmarking can provide key information for quality improvement activities, particularly pre- and postanalytical.

The study of long-lived and regenerative animal models has revealed diverse protective responses to stressors such as aging and tissue injury. Spiny mice (Acomys) are a unique mammalian model of skin wound regeneration, but their response to other types of physiological skin damage has not been investigated. In this study, we examine how spiny mouse skin responds to acute UVB damage or chronological aging compared to non-regenerative C57Bl/6 mice (M. musculus). We find that, compared to M. musculus, the skin epidermis in A. cahirinus experiences a similar UVB-induced increase in basal cell proliferation but exhibits increased epidermal turnover. Notably, A. cahirinus uniquely form a suprabasal layer co-expressing Keratin 14 and Keratin 10 after UVB exposure concomitant with reduced epidermal inflammatory signaling and reduced markers of DNA damage. In the context of aging, old M. musculus animals exhibit typical hallmarks including epidermal thinning, increased inflammatory signaling and senescence. However, these age-related changes are absent in old A. cahirinus skin. Overall, we find that A. cahirinus have evolved novel responses to skin damage that reveals new aspects of its regenerative phenotype.

The study of long-lived and regenerative animal models has revealed diverse protective responses to stressors such as aging and tissue injury. Spiny mice (Acomys) are a unique mammalian model of skin regeneration, but their response to other types of physiological skin damage have not been investigated. In this study, we examine how spiny mice skin responds to acute UVB damage or chronological aging compared to non-regenerative C57Bl/6 mice (M. musculus). We find that, compared to M. musculus, the skin epidermis in A. cahirinus experiences a similar UVB-induced increase in basal cell proliferation but exhibits increased epidermal turnover. Notably, A. cahirinus uniquely form a suprabasal layer co-expressing Keratin 14 and Keratin 10 after UVB exposure concomitant with reduced epidermal inflammatory signaling and reduced markers of DNA damage. In the context of aging, old M. musculus animals exhibit typical hallmarks including epidermal thinning, increased inflammatory signaling and senescence. However, these age-related changes are absent in old A. cahirinus skin. Overall, we find that A. cahirinus have evolved novel responses to skin damage that reveals new aspects of its regenerative phenotype.

Epidermal keratinocytes (KCs) rapidly proliferate to repair the skin barrier, and a strict control of division is necessary for healthy tissue homeostasis. However, the pathways that restrain proliferation after epidermal stress are not known. AMPK is an important signaling mediator of energy metabolism previously associated with skin stress and cancer; yet, its explicit impact on KC growth is not known. To examine the requirement of epidermal AMPK in physiologic skin repair, we genetically deleted AMPK within all adult, keratin 14‒expressing KCs of mice. AMPK loss resulted in hyperproliferation and hyperactive mTOR signaling after acute wounding, UVB exposure, and phorbol ester application. This excessive division could be completely blocked by the mTORC1 inhibitor rapamycin. Moreover, we establish that the diabetes drug metformin depends on AMPK to suppress stress-induced KC proliferation. Collectively, these findings show that KC AMPK restrains mTORC1 to control epidermal proliferation after tissue injury.

Background Evidence describing the association between high-dose benzodiazepine use and dementia has been conflicting. Most previous studies involved Caucasian populations, with only limited data on Chinese subjects. Possible differences exist between Chinese and Caucasian populations with regard to metabolism and prescription practice. This study aimed to assess the association between high-dose benzodiazepine use and dementia in a Chinese population. Method A retrospective case–control study was carried out in all public hospitals under the Hong Kong Hospital Authority Hong Kong West Cluster between 2000 and 2015. The study recruited 273 Chinese adults (91 cases, 182 controls) aged 75 and over, with at least 6 years of follow-up data. Each dementia case was matched with two controls according to sex, age group, and duration of follow-up. The number of patients with benzodiazepine ever-use and the exposure density based on the prescribed daily doses were assessed. Prescribed daily doses were categorized as either

Impaired wound healing in elderly individuals increases infection risk and prolongs surgical recovery, but current treatment options are limited. Low doses of interleukin-15 (IL-15) that mimic exercise responses in the circulation improve skin structure and increase mitochondria in uninjured aged skin, suggesting that IL-15 is an essential mitochondrial signal for healing that is lost during aging. Here we used gene microarray analysis of old and young murine epidermal stem cells and demonstrate that aging results in a gene signature characteristic of bioenergetic dysfunction. Intravenous IL-15 treatment rescued chronological aging-induced healing defects and restored youthful wound closure in old, sedentary mice. Additionally, exercise-mediated improvements in the healing of aged skin depend upon circulating IL-15. We show that IL-15 induces signal transducer and activator of transcription 3 (STAT3) signaling characteristic of young animals, reduces markers of growth arrest, and increases keratinocyte and fibroblast growth. Moreover, exercise or exercise-mimicking IL-15 treatment rescued the age-associated decrease in epidermal mitochondrial complex IV activity. Overall, these results indicate that IL-15 or its analogs represent promising therapies for treating impaired wound healing in elderly patients.

Epidermal stem cells (ESCs) rapidly proliferate to repair the skin barrier and a strict control of division is necessary to sustain stem cell growth capacity. AMP-activated protein kinase (AMPK) is an important signaling mediator of energy metabolism previously associated with skin stress and cancer, yet its impact on ESC proliferation is not known. To examine the requirement of ESC AMPK in physiologic skin repair, we deleted both AMPKα subunits within adult, Keratin 14-expressing ESCs. AMPKα deletion resulted in extensive hyperproliferation following acute wounding, UVB exposure, and phorbol ester application. This augmented stress-induced proliferation was driven by hyperactive mTOR signaling and could be completely blocked by the mTORC1 inhibitor rapamycin. Unexpectedly, after repetitive proliferative stress, ESC AMPKα loss resulted in fewer tumors due to premature growth arrest and reduced ESC proliferative capacity akin to accelerated aging. These findings show that AMPK is essential for controlling mTORC1-driven ESC proliferation and biological aging.

Summary The emergence of circulating vaccine-derived polioviruses through evolution of the oral polio vaccine (OPV) poses a significant obstacle to polio eradication. Understanding the early genetic changes that occur as OPV evolves and transmits is important for preventing future outbreaks. Here, we use deep sequencing to define the evolutionary trajectories of type 2 OPV in a vaccine trial. By sequencing 497 longitudinal stool samples from 271 OPV2 recipients and household contacts, we were able to examine the extent of convergent evolution in vaccinated individuals and the amount of viral diversity that is transmitted. In addition to rapid reversion of key attenuating mutations, we identify strong selection at 19 sites across the genome. We find that a tight transmission bottleneck limits the onward transmission of these early adaptive mutations. Our results highlight the distinct evolutionary dynamics of live attenuated virus vaccines and have important implications for the success of next-generation OPV., Graphical Abstract, Highlights • We used deep sequencing to define the evolutionary trajectories of type 2 OPV • We identified strong positive selection at multiple, non-attenuating sites • Transmission bottleneck limits spread of variants that are selected within hosts • This work provides insights into the evolution of live attenuated virus vaccines, The emergence of vaccine-derived polioviruses through evolution of the oral polio vaccine poses a significant obstacle to global poliovirus eradication. Valesano et al. use sequencing of samples from vaccine recipients and household contacts to identify multiple mutations that are selected within hosts. Tight bottlenecks limit the onward transmission of these variants.

Unlike in most pathogens, multiple-strain (polygenomic) infections of P. falciparum are frequently composed of genetic siblings. These genetic siblings are the result of sexual reproduction and can coinfect the same host when cotransmitted by the same mosquito. The degree with which coinfecting strains are related varies among infections and populations. Because sexual recombination occurs within the mosquito, the relatedness of cotransmitted strains could depend on transmission dynamics, but little is actually known of the factors that influence the relatedness of cotransmitted strains. Part of the uncertainty stems from an incomplete understanding of how within-host and within-vector dynamics affect cotransmission. Cotransmission is difficult to examine experimentally but can be explored using a computational model. We developed a malaria transmission model that simulates sexual reproduction in order to understand what determines the relatedness of cotransmitted strains. This study highlights how the relatedness of cotransmitted strains depends on both within-host and within-vector dynamics including the complexity of infection. We also used our transmission model to analyze the genetic relatedness of polygenomic infections following a series of multiple transmission events and examined the effects of superinfection. Understanding the factors that influence the relatedness of cotransmitted strains could lead to a better understanding of the population-genetic correlates of transmission and therefore be important for public health., Author summary Genomic studies of P. falciparum reveal that multi-strain infections can include genetically related strains. P. falciparum must reproduce sexually in the mosquito vector. One consequence of sexual reproduction is that parasites cotransmitted by the same mosquito are related to one another. The degree of genetic relatedness of these parasites can be as great as that of full-siblings. However, our understanding of the cotransmission process is incomplete, and little is known of the role of cotransmission in influencing population genomic processes. To help bridge this gap, we developed a simulation model to determine which of the steps involved in transmission have the greatest impact on the relatedness of parasites cotransmitted by a mosquito vector. The primary goal of this study is to characterize the outcomes of cotransmission following single or multiple transmission events. Our model yields new insights into the cotransmission process, which we believe will be useful for understanding the results from more complicated population models and epidemiological conditions. Such an understanding is important for the use of population genomics to inform public health decisions as well as for understanding of parasite evolution.

This paper presents two strategies applied in our study, one involved blending CO2-phillic materials such as PEG and PEG-PDMS copolymer with commodity polymer Matrimid® to improve separation performance, another involved development of composite hollow fibre membranes of high CO2 permeance. Blending of PEG and PEG-PDMS copolymer in Matrimid® resulted in hollow fibre membranes with improved gas separation performance. The modification of the membrane microscopic structure also led to improvements in plasticization resistance and tolerance of water content that are important for industrial applications. Composite hollow fibre membranes of high permeance of 550 GPU and selectivity of 45 were developed by using micro-porous PVDF substrate, with multiple coatings PTMSP gutter layers and Pebax®1074 selective layers. Initial tests with mixed gas and short term aging were encouraging while the tests for the tolerance of water and minor components and tests with real flue gas are ongoing.

We will examine the Bianchi Type I universe under the Rainbow Gravity formalism and calculate various quantities like the dynamical equation for the energy density and the negative energy density. Finally, we apply the analysis to a specific Rainbow Gravity model.

Evidence describing the association between high-dose benzodiazepine use and dementia has been conflicting. Most previous studies involved Caucasian populations, with only limited data on Chinese subjects. Possible differences exist between Chinese and Caucasian populations with regard to metabolism and prescription practice. This study aimed to assess the association between high-dose benzodiazepine use and dementia in a Chinese population.A retrospective case-control study was carried out in all public hospitals under the Hong Kong Hospital Authority Hong Kong West Cluster between 2000 and 2015. The study recruited 273 Chinese adults (91 cases, 182 controls) aged 75 and over, with at least 6 years of follow-up data. Each dementia case was matched with two controls according to sex, age group, and duration of follow-up. The number of patients with benzodiazepine ever-use and the exposure density based on the prescribed daily doses were assessed. Prescribed daily doses were categorized as either1096 or ≥1096. Odds ratios and 95% confidence intervals were computed by multivariate analysis.The difference in exposure density between the dementia and control groups was statistically significant between prescribed daily doses1096 and ≥1096 (P = 0.02). There were two multivariate analyses models; one factored in depression (model 1), and the other (model 2) did not. Model 2 showed a statistically significant association (odds ratio = 1.71, 95% confidence intervals = 1.02-2.89, P = 0.04) between benzodiazepine exposure density and dementia.High-dose benzodiazepine use may be associated with dementia in the Chinese population. Prospective studies are required.

Collagen based cosmetic fillers require repeat treatments due to collagenase derived degradation of the filler in the intradermal injection site. The objective of this study was to investigate the inhibition of this degradation by the galloyl-containing compounds tannic acid, epigallocatechin gallate (EGCG), epicatechin gallate (ECG) and gallic acid (GA). A gel permeation chromatography assay was developed to quantitate the collagenase induced reductions in collagen molecular weight. The binding of the compounds to collagen was measured using HPLC. The stabilization of collagen was measured using Differential Scanning Calorimetry (DSC). Tannic acid, EGCG and ECG (but not GA) were found to strongly inhibit collagen degradation at concentrations in the low micromolar range. The compounds bound strongly to collagen and stabilized collagen. It is concluded that tannic acid, EGCG and ECG bind to collagen via extensive hydrogen bonding augmented by some hydrophobic interactions and prevent the free access of collagenase to active sites on the collagen chains.

The utilization of surfactants to increase intestinal absorption of drugs is a viable strategy that benefits from increases in drug solubilization and the potential for inhibition of P-glycoprotein (P-gp) mediated efflux. However, the effective concentration range for P-gp inhibition of most surfactants is defined over a narrow concentration range, below the critical micelle concentration (CMC), as a result of significant micelle sequestration of drug. Therefore, the objectives of these studies were to assess if association of P-gp substrates differing in hydrophobicity will impact the effective concentration range for P-gp inhibition by amphiphilic diblock copolymers based on methoxypolyethylene glycol-block-polycaprolatone (MePEG-b-PCL). Comparisons between the micelle association and Caco-2 cellular accumulation were evaluated using two structurally homologous P-gp substrates, the relatively hydrophobic R-6G and the hydrophilic R-123, over concentrations above and below the CMC for MePEG-b-PCL diblock copolymers. An approximately 3.75-fold enhancement of R-123 accumulation occurred with 2 mM MePEG17-b-PCL5, compared to approximately 1.25-fold for R-6G. This decrease in the accumulation enhancement corresponds with the higher R-6G fraction (0.75) associated at 2 mM MePEG17-b-PCL5 compared with R-123 (0.25). Interestingly, R-6G accumulation was enhanced over a very broad range of MePEG17-b-PCL5 concentrations below the CMC. This was in contrast to R-123, which demonstrated no enhancement below the CMC. A similar concentration dependent accumulation profile was seen with other surfactants such as vitamin E TPGS and Cremophor EL and with two other P-gp substrates differing in hydrophobicity, the relatively hydrophobic paclitaxel and hydrophilic doxorubicin. In conclusion, the effective concentration range for surfactant mediated inhibition of P-gp appears to depend on the P-gp substrate hydrophobicity.

We have previously shown that amphiphilic diblock copolymers composed of methoxypolyethylene glycol-b-polycaprolactone (MePEG-b-PCL) increased the cellular accumulation and reduced the basolateral to apical flux of the P-glycoprotein substrate, rhodamine 123 (R-123) in caco-2 cells. The purpose of this study was to investigate membrane perturbation effects of MePEG-b-PCL diblock copolymers with erythrocyte membranes and caco-2 cells and the effect on P-gp ATPase activity. The diblock copolymer MePEG(17)-b-PCL(5) induced increasing erythrocyte hemolysis at concentrations which correlated with increasing accumulation of R-123 into caco-2 cells. However, no increase in cellular accumulation of R-123 by non-P-gp expressing cells was observed, suggesting that diblock did not enhance the transmembrane passive diffusion of R-123, but that the accumulation enhancement effect of the diblock in caco-2 cells was likely mediated primarily via P-gp inhibition. Fluorescence anisotropy measurements of membrane fluidity and P-gp ATPase activity demonstrated that MePEG(17)-b-PCL(5) decreased caco-2 membrane fluidity while stimulating ATPase activity approximately threefold at concentrations that maximally enhanced R-123 caco-2 accumulation. These results suggest that inhibition of P-gp efflux by MePEG(17)-b-PCL(5) does not appear to be related to increases in membrane fluidity or through inhibition in P-gp ATPase activities, which are two commonly reported cellular effects for P-gp inhibition mediated by surfactants.

The pharmacokinetics and tissue distribution of methotrexate (MTX) were investigated following intra-articular injection of either MTX solution or controlled release MTX loaded microspheres in healthy rabbit joints. MTX solution or MTX loaded microspheres (size 30-100 mum) (10 mg MTX) was injected into the right knee joint cavity of rabbits. Blood samples were taken at predetermined times from the jugular vein. Urine samples were also collected over time periods up to 24 h. The major organs and synovial tissues were removed for analysis 6 and 24 h post-injection (n = 4). MTX and 7-OH-MTX concentrations in the plasma and major organs were determined by HPLC. The MTX plasma area under the concentration-time curve (AUC) for rabbits injected with MTX solution was seven fold higher than that of the rabbits injected with MTX microspheres, while t(1/2) and mean residence time (MRT) were not significantly different between two treatment groups. Four fold more MTX was excreted in the urine from rabbits injected with MTX solution compared to those injected with MTX loaded microspheres 24 h following intra-articular injection. The concentration of MTX in the synovial tissues following intra-articular injection was significantly higher in the rabbits injected with microspheres than in the rabbits injected with MTX solution. MTX solution was rapidly cleared from the joint cavity while MTX encapsulated microspheres retained MTX in the joint cavity.

Mucopolysaccharidosis type IIIB (MPS IIIB, Sanfilippo syndrome type B) is a lysosomal storage disease characterized by profound intellectual disability, dementia, and a lifespan of about two decades. The cause is mutation in the gene encoding α–N-acetylglucosaminidase (NAGLU), deficiency of NAGLU, and accumulation of heparan sulfate. Impediments to enzyme replacement therapy are the absence of mannose 6-phosphate on recombinant human NAGLU and the blood–brain barrier. To overcome the first impediment, a fusion protein of recombinant NAGLU and a fragment of insulin-like growth factor II (IGFII) was prepared for endocytosis by the mannose 6-phosphate/IGFII receptor. To bypass the blood–brain barrier, the fusion protein (“enzyme”) in artificial cerebrospinal fluid (“vehicle”) was administered intracerebroventricularly to the brain of adult MPS IIIB mice, four times over 2 wk. The brains were analyzed 1–28 d later and compared with brains of MPS IIIB mice that received vehicle alone or control (heterozygous) mice that received vehicle. There was marked uptake of the administered enzyme in many parts of the brain, where it persisted with a half-life of approximately 10 d. Heparan sulfate, and especially disease-specific heparan sulfate, was reduced to control level. A number of secondary accumulations in neurons [β-hexosaminidase, LAMP1(lysosome-associated membrane protein 1), SCMAS (subunit c of mitochondrial ATP synthase), glypican 5, β-amyloid, P-tau] were reduced almost to control level. CD68, a microglial protein, was reduced halfway. A large amount of enzyme also appeared in liver cells, where it reduced heparan sulfate and β-hexosaminidase accumulation to control levels. These results suggest the feasibility of enzyme replacement therapy for MPS IIIB.

The objectives of this study were to determine the total plasma and lipoprotein lipid concentration and composition and cholesteryl ester transfer activity in two diabetic animal models (alloxan-induced diabetes in rabbits and streptozotocin-induced diabetes in rats). Furthermore, we wanted to determine if the severity of diabetes influences lipoprotein lipid profiles and cholesteryl ester transfer activity. Rats and rabbits were randomly divided into non-diabetic and diabetic groups. Rats were administered either 55 mg/kg or 100 mg/kg of streptozotocin intravenously through the tail vein, while rabbits were administered 100 mg/kg or 200 mg/kg of alloxan intravenously through the marginal ear vein under light anesthesia. Hyperglycaemia was tested for at 48 hr following the doses. Total and lipoprotein cholesterol and triglyceride concentrations using enzymatic kits and cholesteryl ester transfer activity from low-density lipoproteins to high-density lipoproteins using 3H-cholesteryl ester incorporated into low-density lipoproteins were determined. Elevations in both total and lipoprotein cholesterol and triglyceride concentrations and alterations in lipoprotein lipid composition are observed following the onset of drug-induced diabetes in rats and rabbits compared to non-diabetics. However, these findings were observed only in animals administered the higher streptozotocin and alloxan dose. Furthermore, cholesteryl ester transfer from low-density lipoproteins to high-density lipoproteins is not significantly different in drug-induced diabetic compared to non-diabetic rats and rabbits, regardless of which streptozotocin and alloxan dose was used. These findings suggest that difference in lipoprotein lipid concentration and composition as a result of drug-induced diabetes is independent of cholesteryl ester transfer activity in both rats and rabbits. Furthermore, diabetic severity may influence lipoprotein metabolism in these animal models.

Purpose. The purpose of this study was to define the relationship between lipoprotein (LP) lipid concentration and composition and the distribution of cyclosporine (CSA) in human plasma.

Retrospective chart review.To evaluate and compare the relationship between patients' age and the change in Oxford Knee Score from preoperative to postoperative assessments, and to investigate whether there is a relationship between preoperative Oxford Knee Score results and the indication for total knee replacement surgery, and if age affects this relationship.An increasing number of younger patients receive knee joint replacements, yet it is unknown how this cohort functions after surgery. This warrants investigation into the potential age-related differences in joint function following surgery. The Oxford Knee Score has been validated as a clinical tool but has yet to be accepted in the decision-making process regarding the need for, or appropriateness of, total knee replacement.In a retrospective chart review, 240 patients completed the Oxford Knee Score questionnaire to evaluate chronic pain and/or dysfunction associated with the knee.The largest improvement with joint replacement was observed to occur in the youngest patient group (50-59 years old). Moreover, the Oxford Knee Score was shown to be the strongest predictor (odds ratio = 0.61) for the indicated intervention when compared to other predictors. The youngest patient group reported a significantly (P.03) higher Oxford Knee Score result when indicated for surgery, compared to the oldest patient group (80-89 years old).The results provide insight into how age influences self-perceived joint function before and after joint replacement surgery, and into the clinical decision to provide the surgical option to younger patients. Moreover, the observed relationship between the Oxford Knee Score and the indicated treatment supports the use of the questionnaire as a preoperative tool in considering treatment options for patients with knee osteoarthritis.Prognosis, level 2b.

Biodegradable polymeric paste formulations (‘surgical pastes’) for local delivery of taxol were developed and characterized. Taxol was mixed into melted poly(D,L-lactide)- block -poly(ethylene glycol)- block -poly(D,L-lactide) (PDLLA-PEG-PDLLA) copolymers and blends of low molecular weight poly(D,L-lactic acid) and poly-ϵ-caprolactone (PDLLA:PCL) to obtain the paste formulations. The release of taxol into PBS albumin buffer was measured by HPLC. The polymers and pastes were characterized by gel permeation chromatography (GPC), differential scanning calorimetry (DSC), nuclear magnetic resonance (NMR) and scanning electron microscopy (SEM). Taxol was released in a sustained manner from the PDLLA-PEG-PDLLA paste over a period of 2 months by diffusion and polymer erosion. The release from the blend was mainly erosion controlled and consisted of a burst followed by a period of slow release. Efficacy of the pastes in inhibiting tumor growth in mice was evaluated. Molten, taxol loaded paste formulations were placed at subcutaneous tumor sites in mice (pastes harden at 37°C). After 16 days, the reduction in tumor weight was measured. Both the taxol loaded copolymer and 90:10 PDLLA:PCL blend formulations significantly inhibited tumor growth in mice. The pastes with faster in vitro release rates resulted in greater efficacy in inhibiting tumor growth. The results showed that biodegradable polymeric surgical pastes are promising formulations for the local delivery of taxol to inhibit tumor growth.