Daylight photodynamic therapy as a treatment for for actinic field change in patients diagnosed with Oculocutaneous albinism in Sub-Saharan Africa.

BACKGROUND: Oculocutaneous albinism (OCA) is a genetically inherited condition, whereby melanin is reduced or absent in the skin. A lack of melanin predisposes patients to actinic damage and skin malignancies. In Tanzania, a resource-limited country, the treatment of choice for pre-cancerous skin lesions is cryotherapy. OBJECTIVES: To investigate whether daylight PDT is a safe and well-tolerated treatment for actinic field change in the OCA population in Tanzania. METHODS: 12 participants with actinic damage were recruited from a Standing Voice skin surveillance clinic and treated with dPDT. Study participants completed tolerability and acceptability questionnaires at day 5 and 3-months post-treatment. A dermatologist assessed clinical response to dPDT at 3 months. RESULTS: Daylight PDT was well-tolerated and acceptable to the majority of patients. Actinic damage was reduced by 25-90%. No skin cancers developed during the treatment. CONCLUSIONS: This pilot study suggests that dPDT is a safe and tolerable treatment for actinic damage in the OCA population in Tanzania. Further work is required to compare the efficacy of dPDT against other topical therapies for actinic field change.

¿Agua para todos? La intermitencia en el suministro de agua en los hogares en México.

OBJETIVO: Medir el acceso a través de la intermitencia en el suministro de agua potable en hogares mexicanos. Material y métodos. A través de la Encuesta Nacional de Salud y Nutrición 2022 (Ensanut 2022), se recolectó información sobre intermitencia en días por semana y horas por día durante las últimas cuatro semanas y el suministro de agua durante el año para la temporada de mayor escasez. RESULTADOS: 31.5% de los hogares recibieron agua los siete días de la semana, las 24 horas del día. De estos, 17.4% no tuvo escasez en los últimos 12 meses. La intermitencia es más común entre hogares de las regiones en el sur del país y entre los más pobres. El 81% de las familias almacena agua y 16% almacena en contenedores portátiles como cubetas. Conclusión. En este artículo se presentan por primera vez patrones de intermitencia en el suministro de agua a nivel nacional en México. La gran mayoría de las familias no reciben agua de forma continua y tienen que almacenar agua. El almacenamiento podría disminuir la calidad del agua y la falta de confianza para su consumo con consecuencias para la salud. La conexión al sistema potable no refleja el acceso real de las familias al agua.

Amyloidogenic Processing of Amyloid Precursor Protein Drives Stretch-Induced Disruption of Axonal Transport in hiPSC-Derived Neurons.

Traumatic brain injury (TBI) results in disrupted brain function following impact from an external force and is a risk factor for sporadic Alzheimer's disease (AD). Although neurologic symptoms triggered by mild traumatic brain injuries (mTBI), the most common form of TBI, typically resolve rapidly, even an isolated mTBI event can increase the risk to develop AD. Aberrant accumulation of amyloid ß peptide (Aß), a cleaved fragment of amyloid precursor protein (APP), is a key pathologic outcome designating the progression of AD following mTBI and has also been linked to impaired axonal transport. However, relationships among mTBI, amyloidogenesis, and axonal transport remain unclear, in part because of the dearth of human models to study the neuronal response following mTBI. Here, we implemented a custom-microfabricated device to deform neurons derived from human-induced pluripotent stem cells, derived from a cognitively unimpaired male individual, to mimic the mild stretch experienced by neurons during mTBI. Although no cell lethality or cytoskeletal disruptions were observed, mild stretch was sufficient to stimulate rapid amyloidogenic processing of APP. This processing led to abrupt cessation of APP axonal transport and progressive formation of aberrant axonal accumulations that contained APP, its processing machinery, and amyloidogenic fragments. Consistent with this sequence of events, stretch-induced defects were abrogated by reducing amyloidogenesis either pharmacologically or genetically. In sum, we have uncovered a novel and manipulable stretch-induced amyloidogenic pathway directly responsible for APP axonal transport dysregulation. Our findings may help to understand and ultimately mitigate the risk of developing AD following mTBI.SIGNIFICANCE STATEMENT Mild traumatic brain injury is a risk factor for sporadic Alzheimer's disease (AD). Increased amyloid ß peptide generation after injury may drive this risk. Here, by using a custom-built device to impose mild stretch to human neurons, we found that stretch triggers amyloid precursor protein (APP) cleavage, and thus amyloid ß peptide generation, consequently disrupting APP axonal transport. Compellingly, protecting APP from cleavage was sufficient to spare axonal transport dysregulation and the consequent aberrant axonal accumulation of APP. Supporting such protective mechanism, the expression of the AD-protective APPA673T genetic variant conferred protection against stretch-induced APP axonal transport phenotypes. Our data reveal potential subcellular pathways contributing to the development of AD-associated phenotypes following mild traumatic brain injury, and putative strategies for intervening in these pathways.

Diverse Molecular Mechanisms Contribute to Differential Expression of Human Duplicated Genes.

Emerging evidence links genes within human-specific segmental duplications (HSDs) to traits and diseases unique to our species. Strikingly, despite being nearly identical by sequence (>98.5%), paralogous HSD genes are differentially expressed across human cell and tissue types, though the underlying mechanisms have not been examined. We compared cross-tissue mRNA levels of 75 HSD genes from 30 families between humans and chimpanzees and found expression patterns consistent with relaxed selection on or neofunctionalization of derived paralogs. In general, ancestral paralogs exhibited greatest expression conservation with chimpanzee orthologs, though exceptions suggest certain derived paralogs may retain or supplant ancestral functions. Concordantly, analysis of long-read isoform sequencing data sets from diverse human tissues and cell lines found that about half of derived paralogs exhibited globally lower expression. To understand mechanisms underlying these differences, we leveraged data from human lymphoblastoid cell lines (LCLs) and found no relationship between paralogous expression divergence and post-transcriptional regulation, sequence divergence, or copy-number variation. Considering cis-regulation, we reanalyzed ENCODE data and recovered hundreds of previously unidentified candidate CREs in HSDs. We also generated large-insert ChIP-sequencing data for active chromatin features in an LCL to better distinguish paralogous regions. Some duplicated CREs were sufficient to drive differential reporter activity, suggesting they may contribute to divergent cis-regulation of paralogous genes. This work provides evidence that cis-regulatory divergence contributes to novel expression patterns of recent gene duplicates in humans.

Sleep Difficulties among Mexican Adolescents: Subjective and Objective Assessments of Sleep.

OBJECTIVE/BACKGROUND: Self-reported sleep difficulties, such as insomnia symptoms, have been reported among adolescents. Yet, studies of their prevalence and correlates are scarce among Latin Americans. This study sought (1) to describe associations between sociodemographic and lifestyle factors with self-reported sleep difficulties and (2) to examine associations between self-reported sleep difficulties and actigraphy-based sleep. PARTICIPANTS: Participants included 477 Mexican adolescents from the ELEMENT cohort. METHODS: Over 7 days, self-reported sleep measures (hard time falling asleep, overall sleep difficulties, and specific types of sleep difficulties) were obtained from daily sleep diaries. Actigraphy-based sleep measures (duration, i.e. sleep onset to morning wake, midpoint, and fragmentation) were concurrently assessed using a wrist actigraph. RESULTS: Mean (SD) age was 15.9 (2.2) years, and 53.5% were females. Mean (SD) sleep duration was 8.5 (1.2) h/night. Half reported a hard time falling asleep at least 3 days, and 25% had sleep difficulties at least 3 days over 7 days. The 3 types of sleep difficulties commonly reported among the entire cohort were insomnia/restlessness (29%), environmental (27%), and mental/emotional difficulties (19%). Female sex, smoking behavior, and socioeconomic indicators were among the most consistent factors associated with sleep difficulties. Subjective sleep difficulties were associated with shorter sleep duration (ß = -20.8 [-35.3, -6.2] min), while subjective hard time falling asleep was associated with longer sleep duration (ß = 11.3 [4.6, 27.2] min). CONCLUSION: A high proportion of Mexican adolescents in the sample reported sleep difficulties. Findings demonstrate the importance of obtaining subjective and objective sleep measures for a more comprehensive assessment of adolescent sleep.

Improving patient-centred care through a tailored intervention addressing nursing clinical handover communication in its organizational and cultural context.

AIMS: To increase the quality and safety of patient care, many hospitals have mandated that nursing clinical handover occur at the patient's bedside. This study aims to improve the patient-centredness of nursing handover by addressing the communication challenges of bedside handover and the organizational and cultural practices that shape handover. DESIGN: Qualitative linguistic ethnographic design combining discourse analysis of actual handover interactions and interviews and focus groups before and after a tailored intervention. METHODS: Pre-intervention we conducted interviews with nursing, medical and allied health staff (n = 14) and focus groups with nurses and students (n = 13) in one hospital's Rehabilitation ward. We recorded handovers (n = 16) and multidisciplinary team huddles (n = 3). An intervention of communication training and recommendations for organizational and cultural change was delivered to staff and championed by ward management. After the intervention we interviewed nurses and recorded and analyzed handovers. Data were collected from February to August 2020. Ward management collected hospital-acquired complication data. RESULTS: Notable changes post-intervention included a shift to involve patients in bedside handovers, improved ward-level communication and culture, and an associated decrease in reported hospital-acquired complications. CONCLUSIONS: Effective change in handover practices is achieved through communication training combined with redesign of local practices inhibiting patient-centred handovers. Strong leadership to champion change, ongoing mentoring and reinforcement of new practices, and collaboration with nurses throughout the change process were critical to success. IMPACT: Ineffective communication during handover jeopardizes patient safety and limits patient involvement. Our targeted, locally designed communication intervention significantly improved handover practices and patient involvement through the use of informational and interactional protocols, and redesigned handover tools and meetings. Our approach promoted a ward culture that prioritizes patient-centred care and patient safety. This innovative intervention resulted in an associated decrease in hospital-acquired complications. The intervention has been rolled out to a further five wards across two hospitals.

Cellular benefits of single-use negative pressure wound therapy demonstrated in a novel ex vivo human skin wound model.

Negative pressure wound therapy is a widely used treatment for chronic, nonhealing wounds. Surprisingly, few studies have systematically evaluated the cellular and molecular effects of negative pressure treatment on human skin. In addition, no study to date has directly compared recently available single-use negative pressure modalities to traditional negative pressure devices in a controlled setting. Here we developed a novel large-scale ex vivo human skin culture system to effectively evaluate the efficacy of two different negative pressure wound therapy modalities. Single-use and traditional negative pressure devices were applied to human ex vivo wounded skin sheets cultured over a period of 48 hours. Cellular tissue response to therapy was evaluated via a combination of histological analysis and transcriptional profiling, in samples collected from the wound edge, skin adjacent to the wound, and an extended skin region. Single-use negative pressure wound therapy caused less damage to wound edge tissue than traditional application, demonstrated by improved skin barrier, reduced dermal-epidermal junction disruption and a dampened damage response. Transcriptional profiling confirmed significantly less activation of multiple pro-inflammatory markers in wound edge skin treated with single-use vs traditional negative pressure therapy. These findings may help to explain the greater efficacy of sNPWT in the clinic, while offering a noninvasive system to develop improved NPWT-based therapies.

Foliar Application of Copper Oxide Nanoparticles Suppresses Fusarium Wilt Development on Chrysanthemum.

Micronutrients applied as nanoparticles of metal oxides have shown efficacy in vegetable and other crops for improving yield and reducing Fusarium diseases, but their role in ornamental crop management has not been investigated. In 2017, 2018, and 2020, nanoparticles of CuO, Mn2O3, or ZnO were foliarly applied at 500 µg/mL (0.6 mg/plant) to chrysanthemum transplants and planted in potting soil noninfested or infested with Fusarium oxysporum f. sp. chrysanthemi. An untreated control and a commercial fungicide, Fludioxonil, was also included. Chrysanthemums treated with nanoscale CuO had a 55, 30, and 32% reduction in disease severity ratings compared to untreated plants in 2017, 2018, and 2020, respectively. Specifically, the average dry biomass for the three years was reduced 22% by disease, but treatment with nanoscale CuO led to a 23% increase when compared to controls. Similar trends with plant height were observed. Horticultural quality was improved 28% with nano CuO and was equal to the fungicide. Nanoscale Mn2O3 and the fungicide did not consistently reduce disease ratings or increase dry biomass each year. Nanoscale ZnO was ineffective. Nanoscale CuO-treated plants had 24 to 48% more Cu/g tissue than controls (P < 0.001). These findings agree with past reports on food crops where single applications of nanoscale CuO improved plant health, growth, and yield and could offer significant impacts for managing plant diseases on ornamentals.

Tissue Iron Promotes Wound Repair via M2 Macrophage Polarization and the Chemokine (C-C Motif) Ligands 17 and 22.

Macrophages are important for effective iron recycling and erythropoiesis, but they also play a crucial role in wound healing, orchestrating tissue repair. Recently, we demonstrated a significant accumulation of iron in healing wounds and a requirement of iron for effective repair. Herein, we sought to determine the influence of iron on macrophage function in the context of wound healing. Interestingly, wound macrophages extensively sequestered iron throughout healing, associated with a prohealing M2 phenotype. In delayed healing diabetic mouse wounds, both macrophage polarization and iron sequestration were impaired. In vitro studies revealed that iron promotes differentiation, while skewing macrophages toward a hypersecretory M2-like polarization state. These macrophages produced high levels of chemokine (C-C motif) ligands 17 and 22, promoting wound reepithelialization and extracellular matrix deposition in a human ex vivo wound healing model. Together, these findings reveal a novel, unappreciated role for iron in modulating macrophage behavior to promote subsequent wound repair. These findings support therapeutic evaluation of iron use to promote wound healing in the clinic.

Low program access despite high burden of sexual, structural, and reproductive health vulnerabilities among young women who sell sex in Mombasa, Kenya.

BACKGROUND: Across Sub-Saharan Africa, young women who sell sex (YSW) face institutional barriers in accessing sexual health and HIV prevention programs designed for female sex workers. In 2018, Kenya developed a national framework to guide service provision for YSW aged 14-24 years. To help inform the implementation of the framework, we estimated the burden of vulnerabilities related to the Sustainable Development Goals (SDGs related to health and gender equality) and program contact among YSW. METHODS: We used data from Transitions, a 2015 bio-behavioural cross-sectional survey of 408 YSW aged 14-24 years in Mombasa, Kenya. We estimated the prevalence of sexual (inconsistent condom use), structural (financial, violence), and reproductive health vulnerabilities; and characterized engagement with local HIV programs tailored to sex workers. We then compared the prevalence of vulnerabilities by age group (14-18 years, N = 117; 19-24 years, N = 291) and by program contact (ever contacted by local program for sex workers). RESULTS: 47.3% reported inconsistent condom use with any partner in the previous week (no difference by age-group, p = 1.00). Structural vulnerabilities were common and did not vary by age: 83.6% did not have a regular source of income; 29.9 and 29.2% had experienced physical and sexual violence, respectively. 26.5% reported at least one pregnancy before age 18, and 18.5% used a non-reliable form of contraception with little variability by age. 25.7% were aware of at least one program, and only 13.7% of YSW had ever been contacted by a program (8.5% of those aged 14-18 years; and 15.8% of those aged 19-24 years, p = 0.06). Sexual, structural, and reproductive health vulnerabilities did not vary by program contact. CONCLUSIONS: SDG-related vulnerabilities begin early in the lives of YSW who are not currently reached by programs designed for female sex workers.

Exploring dietary patterns in a Mexican adolescent population: A mixed methods approach.

To explore dietary patterns within the context of the nutrition transition among Mexican adolescents, we employed a mixed-methodology that included survey data from a cohort of 550 adolescents and direct ethnographic observations of six families. From the cohort study, we found that diet tended to cluster into 3 patterns. Interpreting the patterns using the ethnographic observations showed that the dietary clustering likely reflected differences in meal organization driven by socioeconomic status (SES). In particular, families of higher SES could afford to prepare larger home-cooked meals on a regular basis while lower SES households had less-stable patterns and greater reliance on processed food. These findings provide a more nuanced interpretation of dietary patterns observed in the Mexico population than is afforded by the food items alone (i.e. a "healthy" or "prudent" pattern versus "unhealthy" or "Westernized").

Full-length amyloid precursor protein regulates lipoprotein metabolism and amyloid-ß clearance in human astrocytes.

Mounting evidence suggests that alterations in cholesterol homeostasis are involved in Alzheimer's disease (AD) pathogenesis. Amyloid precursor protein (APP) or multiple fragments generated by proteolytic processing of APP have previously been implicated in the regulation of cholesterol metabolism. However, the physiological function of APP in regulating lipoprotein homeostasis in astrocytes, which are responsible for de novo cholesterol biosynthesis and regulation in the brain, remains unclear. To address this, here we used CRISPR/Cas9 genome editing to generate isogenic APP-knockout (KO) human induced pluripotent stem cells (hiPSCs) and differentiated them into human astrocytes. We found that APP-KO astrocytes have reduced cholesterol and elevated levels of sterol regulatory element-binding protein (SREBP) target gene transcripts and proteins, which were both downstream consequences of reduced lipoprotein endocytosis. To elucidate which APP fragments regulate cholesterol homeostasis and to examine whether familial AD mutations in APP affect lipoprotein metabolism, we analyzed an isogenic allelic series harboring the APP Swedish and APP V717F variants. Only astrocytes homozygous for the APP Swedish (APPSwe/Swe) mutation, which had reduced full-length APP (FL APP) due to increased ß-secretase cleavage, recapitulated the APP-KO phenotypes. Astrocytic internalization of ß-amyloid (Aß), another ligand for low-density lipoprotein (LDL) receptors, was also impaired in APP-KO and APPSwe/Swe astrocytes. Finally, impairing cleavage of FL APP through ß-secretase inhibition in APPSwe/Swe astrocytes reversed the LDL and Aß endocytosis defects. In conclusion, FL APP is involved in the endocytosis of LDL receptor ligands and is required for proper cholesterol homeostasis and Aß clearance in human astrocytes.

Assessing the influence of conflict on the dynamics of sex work and the HIV and HCV epidemics in Ukraine: protocol for an observational, ethnographic, and mathematical modeling study.

BACKGROUND: Armed conflict erupted in eastern Ukraine in 2014 and still continues. This conflict has resulted in an intensification of poverty, displacement and migration, and has weakened the local health system. Ukraine has some of the highest rates of HIV and Hepatitis C (HCV) in Europe. Whether and how the current conflict, and its consequences, will lead to changes in the HIV and HCV epidemic in Ukraine is unclear. Our study aims to characterize how the armed conflict in eastern Ukraine and its consequences influence the pattern, practice, and experience of sex work and how this affects HIV and HCV rates among female sex workers (FSWs) and their clients. METHODS: We are implementing a 5-year mixed methods study in Dnipro, eastern Ukraine. Serial mapping and size estimation of FSWs and clients will be conducted followed by bio-behavioral cross-sectional surveys among FSWs and their clients. The qualitative component of the study will include in-depth interviews with FSWs and other key stakeholders and participant diaries will be implemented with FSWs. We will also conduct an archival review over the course of the project. Finally, we will use these data to develop and structure a mathematical model with which to estimate the potential influence of changes due to conflict on the trajectory of HIV and HCV epidemics among FSW and clients. DISCUSSION: The limited data that exists on the effect of conflict on disease transmission provides mixed results. Our study will provide rigorous, timely and context-specific data on HIV and HCV transmission in the setting of conflict. This information can be used to inform the design and delivery of HIV and HCV prevention and care services.

Omalizumab facilitates rapid oral desensitization for peanut allergy.

BACKGROUND: Peanut oral immunotherapy is a promising approach to peanut allergy, but reactions are frequent, and some patients cannot be desensitized. The anti-IgE medication omalizumab (Xolair; Genentech, South San Francisco, Calif) might allow more rapid peanut updosing and decrease reactions. OBJECTIVE: We sought to evaluate whether omalizumab facilitated rapid peanut desensitization in highly allergic patients. METHODS: Thirty-seven subjects were randomized to omalizumab (n = 29) or placebo (n = 8). After 12 weeks of treatment, subjects underwent a rapid 1-day desensitization of up to 250 mg of peanut protein, followed by weekly increases up to 2000 mg. Omalizumab was then discontinued, and subjects continued on 2000 mg of peanut protein. Subjects underwent an open challenge to 4000 mg of peanut protein 12 weeks after stopping study drug. If tolerated, subjects continued on 4000 mg of peanut protein daily. RESULTS: The median peanut dose tolerated on the initial desensitization day was 250 mg for omalizumab-treated subjects versus 22.5 mg for placebo-treated subject. Subsequently, 23 (79%) of 29 subjects randomized to omalizumab tolerated 2000 mg of peanut protein 6 weeks after stopping omalizumab versus 1 (12%) of 8 receiving placebo (P < .01). Twenty-three subjects receiving omalizumab versus 1 subject receiving placebo passed the 4000-mg food challenge. Overall reaction rates were not significantly lower in omalizumab-treated versus placebo-treated subjects (odds ratio, 0.57; P = .15), although omalizumab-treated subjects were exposed to much higher peanut doses. CONCLUSION: Omalizumab allows subjects with peanut allergy to be rapidly desensitized over as little as 8 weeks of peanut oral immunotherapy. In the majority of subjects, this desensitization is sustained after omalizumab is discontinued. Additional studies will help clarify which patients would benefit most from this approach.

Does Zoning Winter Recreationists Reduce Recreation Conflict?

Parks and protected area managers use zoning to decrease interpersonal conflict between recreationists. Zoning, or segregation, of recreation-often by non-motorized and motorized activity-is designed to limit physical interaction while providing recreation opportunities to both groups. This article investigated the effectiveness of zoning to reduce recreation conflict in the Vail Pass Winter Recreation Area in Colorado, USA. Despite a zoning management system, established groomed travel routes were used by both non-motorized recreationists (backcountry skiers, snowboarders, snowshoers) and motorized recreationists (snowmobilers). We hypothesized that persistent recreation conflict reported by non-motorized recreationists was the result of recreation occurring in areas of mixed non-motorized and motorized use, mostly along groomed routes. We performed a geospatial analysis of recreation [from Global Positioning System (GPS) points, n = 1,233,449] in the Vail Pass Winter Recreation Area to identify areas of mixed non-motorized and motorized use. We then surveyed non-motorized recreationists (n = 199) to test whether reported conflict is higher for respondents who traveled in areas of mixed-use, compared with respondents traveling outside areas of mixed-use. Results from the geospatial analysis showed that only 0.7 % of the Vail Pass Winter Recreation Area contained recreation from both groups, however that area contained 14.8 % of all non-motorized recreation and 49.1 % of all motorized recreation. Survey analysis results showed higher interpersonal conflict for all five standard conflict variables among non-motorized respondents who traveled in areas of mixed-use, compared with those traveling outside mixed-use areas. Management implications and recommendations for increasing the effectiveness of zoning are provided.

Evaluation of injectable robenacoxib for the treatment of post-operative pain in cats: results of a randomized, masked, placebo-controlled clinical trial.

BACKGROUND: Few pharmaceuticals are registered in cats for the management of post-operative pain and inflammation. The objective of this study was to assess the field efficacy and safety of an injectable formulation of the nonsteroidal anti-inflammatory drug robenacoxib in cats undergoing surgery. The study was a multi-center, prospective, randomized, masked, parallel-group, placebo-controlled clinical trial. A total of 349 cats were enrolled and underwent surgery comprising forelimb onychectomy, as an example of orthopedic surgery, plus either ovariohysterectomy or castration. All cats received butorphanol prior to anesthesia and forelimb four-point regional nerve blocks with bupivacaine after induction of general anesthesia. Cats were randomized to receive daily subcutaneous (s.c.) injection of robenacoxib, at a target dosage of 2.0 mg/kg (n = 174), or placebo (n = 175) once prior to surgery and for an additional two days post-operatively. RESULTS: Significantly (P = 0.037) fewer cats administered robenacoxib received additional analgesia rescue therapy (34 of 173, 19.7 %) compared to cats given placebo (73 of 175, 41.7 %). The percentage of treatment success was therefore 80.3 % with robenacoxib and 58.3 % with placebo. Behavior, posture, pain on palpation of the paw and soft tissue surgery sites, and overall pain were significantly (P < 0.05) improved versus placebo at various time points within the first 8 h in cats receiving robenacoxib. The most frequently reported adverse events were incision site infection/dehiscence, bleeding, vomiting, decreased appetite and lethargy. Frequencies of reported adverse clinical signs, hematology, serum chemistry and urinalysis variables, and body weight changes were similar between groups. There were no significant changes from baseline with robenacoxib in hepatic, hematological or renal clinical pathology variables. CONCLUSIONS: Robenacoxib by s.c. injection was effective and well tolerated in the control of post-operative pain associated with orthopedic, ovariohysterectomy and castration surgery in cats.

Antifungal Saponins from the Maya Medicinal Plant Cestrum schlechtendahlii G. Don (Solanaceae).

Bioassay-guided fractionation of the crude extract (80% EtOH) of the leaves of Cestrum schlechtendahlii, a plant used by Q'eqchi' Maya healers for treatment of athlete's foot, resulted in the isolation and identification of two spirostanol saponins (1 and 2). Structure elucidation by MS, 1D-NMR, and 2D-NMR spectroscopic methods identified them to be the known saponin (25R)-1ß,2α-dihydroxy-5α-spirostan-3-ß-yl-O-α-L-rhamnopyranosyl-(1 → 2)-ß-D-galactopyranoside (1) and new saponin (25R)-1ß,2α-dihydroxy-5α-spirostan-3-ß-yl-O-ß-D-galactopyranoside (2). While 2 showed little or no antifungal activity at the highest concentration tested, 1 inhibited growth of Saccharomyces cerevisiae (minimum inhibitory concentration (MIC) of 15-25 µM), Candida albicans, Cryptococcus neoformans, and Fusarium graminearum (MIC of 132-198 µM).

Disruption and therapeutic rescue of autophagy in a human neuronal model of Niemann Pick type C1.

An unresolved issue about many neurodegenerative diseases is why neurons are particularly sensitive to defects in ubiquitous cellular processes. One example is Niemann Pick type C1, caused by defects in cholesterol trafficking in all cells, but where neurons are preferentially damaged. Understanding this selective failure is limited by the difficulty in obtaining live human neurons from affected patients. To solve this problem, we generated neurons with decreased function of NPC1 from human embryonic stem cells and used them to test the hypothesis that defective cholesterol handling leads to enhanced pathological phenotypes in neurons. We found that human NPC1 neurons have strong spontaneous activation of autophagy, and, contrary to previous reports in patient fibroblasts, a block of autophagic progression leading to defective mitochondrial clearance. Mitochondrial fragmentation is an exceptionally severe phenotype in NPC1 neurons compared with fibroblasts, causing abnormal accumulation of mitochondrial proteins. Contrary to expectation, these abnormal phenotypes were rescued by treatment with the autophagy inhibitor 3-methyladenine and by treatment with the potential therapeutic cyclodextrin, which mobilizes cholesterol from the lysosomal compartment. Our findings suggest that neurons are especially sensitive to lysosomal cholesterol accumulation because of autophagy disruption and accumulation of fragmented mitochondria, thus defining a new route to effective drug development for NPC1 disease.