Rifampin- and Silymarin-Mediated Pharmacokinetic Interactions of Exogenous and Endogenous Substrates in a Transgenic OATP1B Mouse Model.

Organic anion-transporting polypeptides (OATP) 1B1 and OATP1B3, encoded by the SLCO gene family of the solute carrier superfamily, are involved in the disposition of many exogenous and endogenous compounds. Preclinical rodent models help assess risks of pharmacokinetic interactions, but interspecies differences in transporter orthologs and expression limit direct clinical translation. An OATP1B transgenic mouse model comprising a rodent Slco1a/1b gene cluster knockout and human SLCO1B1 and SLCO1B3 gene insertions provides a potential physiologically relevant preclinical tool to predict pharmacokinetic interactions. Pharmacokinetics of exogenous probe substrates, pitavastatin and pravastatin, and endogenous OATP1B biomarkers, coproporphyrin-I and coproporphyrin-III, were determined in the presence and absence of known OATP/Oatp inhibitors, rifampin or silymarin (an extract of milk thistle [Silybum marianum]), in wild-type FVB mice and humanized OATP1B mice. Rifampin increased exposure of pitavastatin (4.6- and 2.8-fold), pravastatin (3.6- and 2.2-fold), and coproporphyrin-III (1.6- and 2.1-fold) in FVB and OATP1B mice, respectively, but increased coproporphyrin-I AUC0-24h only (1.8-fold) in the OATP1B mice. Silymarin did not significantly affect substrate AUC, likely because the silymarin flavonolignan concentrations were at or below their reported IC50 values for the relevant OATPs/Oatps. Silymarin increased the Cmax of pitavastatin 2.7-fold and pravastatin 1.9-fold in the OATP1B mice. The data of the OATP1B mice were similar to those of the pitavastatin and pravastatin clinical data; however, the FVB mice data more closely recapitulated pitavastatin clinical data than the data of the OATP1B mice, suggesting that the OATP1B mice are a reasonable, though costly, preclinical strain for predicting pharmacokinetic interactions when doses are optimized to achieve clinically relevant plasma concentrations.

Pharmacokinetic Effects of Different Models of Nonalcoholic Fatty Liver Disease in Transgenic Humanized OATP1B Mice.

Organic anion transporting polypeptide (OATP) 1B1 and OATP1B3 (collectively, OATP1B) transporters encoded by the solute carrier organic anion transporter (SLCO) genes mediate uptake of multiple pharmaceutical compounds. Nonalcoholic steatohepatitis (NASH), a severe form of nonalcoholic fatty liver disease (NAFLD), decreases OATP1B abundance. This research characterized the pathologic and pharmacokinetics effects of three diet- and one chemical-induced NAFLD model in male and female humanized OATP1B mice, which comprises knock-out of rodent Oatp orthologs and insertion of human SLCO1B1 and SLCO1B3. Histopathology scoring demonstrated elevated steatosis and inflammation scores for all NAFLD-treatment groups. Female mice had minor changes in SLCO1B1 expression in two of the four NAFLD treatment groups, and pitavastatin (PIT) area under the concentration-time curve (AUC) increased in female mice in only one of the diet-induced models. OATP1B3 expression decreased in male and female mice in the chemical-induced NAFLD model, with a coinciding increase in PIT AUC, indicating the chemical-induced model may better replicate changes in OATP1B3 expression and OATP substrate disposition observed in NASH patients. This research also tested a reported multifactorial pharmacokinetic interaction between NAFLD and silymarin, an extract from milk thistle seeds with notable OATP-inhibitory effects. Males showed no change in PIT AUC, whereas female PIT AUC increased 1.55-fold from the diet alone and the 1.88-fold from the combination of diet with silymarin, suggesting that female mice are more sensitive to pharmacokinetic changes than male mice. Overall, the humanized OATP1B model should be used with caution for modeling NAFLD and multifactorial pharmacokinetic interactions. SIGNIFICANCE STATEMENT: Advanced stages of NAFLD cause decreased hepatic OATP1B abundance and increase systemic exposure to OATP substrates in human patients. The humanized OATP1B mouse strain may provide a clinically relevant model to recapitulate these observations and predict pharmacokinetic interactions in NAFLD. This research characterized three diet-induced and one drug-induced NAFLD model in a humanized OATP1B mouse model. Additionally, a multifactorial pharmacokinetic interaction was observed between silymarin and NAFLD.

Green Tea Catechins Decrease Solubility of Raloxifene In Vitro and Its Systemic Exposure in Mice.

PURPOSE: Green tea is a widely consumed beverage. A recent clinical study reported green tea decreased systemic exposure of raloxifene and its glucuronide metabolites by 34-43%. However, the underlying mechanism(s) remains unknown. This study investigated a change in raloxifene's solubility as the responsible mechanism. METHODS: The effects of green tea extract, (-)-epigallocatechin gallate (EGCG), and (-)-epigallocatechin (EGC) on raloxifene's solubility were assessed in fasted state simulated intestinal fluids (FaSSIF) and fed state simulated intestinal fluids (FeSSIF). EGCG and EGC represent green tea's main bioactive constituents, flavan-3-gallate and flavan-3-ol catechins respectively, and the tested concentrations (mM) match the µg/mg of each compound in the extract. Our mouse study (n = 5/time point) evaluated the effect of green tea extract and EGCG on the systemic exposure of raloxifene. RESULTS: EGCG (1 mM) and EGC (1.27 mM) decreased raloxifene's solubility in FaSSIF by 78% and 13%, respectively. Micelle size in FaSSIF increased with increasing EGCG concentrations (> 1000% at 1 mM), whereas EGC (1.27 mM) did not change micelle size. We observed 3.4-fold higher raloxifene solubility in FeSSIF compared to FaSSIF, and neither green tea extract nor EGCG significantly affected raloxifene solubility or micelle size in FeSSIF. The mice study showed that green tea extract significantly decreased raloxifene Cmax by 44%, whereas EGCG had no effect. Green tea extract and EGCG did not affect the AUC0-24 h of raloxifene or the metabolite-to-parent AUC ratio. CONCLUSIONS: This study demonstrated flavan-3-gallate catechins may decrease solubility of poorly water-soluble drugs such as raloxifene, particularly in the fasted state.

Goldenseal-Mediated Inhibition of Intestinal Uptake Transporters Decreases Metformin Systemic Exposure in Mice.

Goldenseal is a perennial plant native to eastern North America. A recent clinical study reported goldenseal decreased metformin Cmax and area under the blood concentration versus time curve (AUC) by 27% and 23%, respectively, but half-life and renal clearance were unchanged. These observations suggested goldenseal altered processes involved in metformin absorption. The underlying mechanism(s) remain(s) unknown. One mechanism for the decreased metformin systemic exposure is inhibition by goldenseal of intestinal uptake transporters involved in metformin absorption. Goldenseal extract and three goldenseal alkaloids (berberine, (-)-ß-hydrastine, hydrastinine) were tested as inhibitors of organic cation transporter (OCT) 3, plasma membrane monoamine transporter (PMAT), and thiamine transporter (THTR) 2 using human embryonic kidney 293 cells overexpressing each transporter. The goldenseal extract, normalized to berberine content, was the strongest inhibitor of each transporter (IC50: 4.9, 13.1, and 5.8 µM for OCT3, PMAT, and THTR2, respectively). A pharmacokinetic study in mice compared the effects of berberine, (-)-ß-hydrastine, goldenseal extract, and imatinib (OCT inhibitor) on orally administered metformin. Goldenseal extract and imatinib significantly decreased metformin Cmax by 31% and 25%, respectively, and had no effect on half-life. Berberine and (-)-ß-hydrastine had no effect on metformin pharmacokinetics, indicating neither alkaloid alone precipitated the interaction in vivo. A follow-up murine study involving intravenous metformin and oral inhibitors examined the contributions of basolateral enteric/hepatic uptake transporters to the goldenseal-metformin interaction. Goldenseal extract and imatinib had no effect on metformin AUC and half-life, suggesting lack of inhibition of basolateral enteric/hepatic uptake transporters. Results may have implications for patients taking goldenseal with drugs that are substrates for OCT3 and THTR2. SIGNIFICANCE STATEMENT: Goldenseal is used to self-treat respiratory infections and digestive disorders. We investigated potential mechanisms for the clinical pharmacokinetic interaction observed between goldenseal and metformin, specifically inhibition by goldenseal of intestinal uptake transporters (OCT3, PMAT, THTR2) involved in metformin absorption. Goldenseal extract inhibited all three transporters in vitro and decreased metformin systemic exposure in mice. These data may have broader implications for patients co-consuming goldenseal with other drugs that are substrates for these transporters.

Migration towards Bangladesh coastlines projected to increase with sea-level rise through 2100.

To date, projections of human migration induced by sea-level change (SLC) largely suggest large-scale displacement away from vulnerable coastlines. However, results from our model of Bangladesh suggest counterintuitively that people will continue to migrate toward the vulnerable coastline irrespective of the flooding amplified by future SLC under all emissions scenarios until the end of this century. We developed an empirically calibrated agent-based model of household migration decision-making that captures the multi-faceted push, pull and mooring influences on migration at a household scale. We then exposed ~4800 000 simulated migrants to 871 scenarios of projected 21st-century coastal flooding under future emissions pathways. Our model does not predict flooding impacts great enough to drive populations away from coastlines in any of the scenarios. One reason is that while flooding does accelerate a transition from agricultural to non-agricultural income opportunities, livelihood alternatives are most abundant in coastal cities. At the same time, some coastal populations are unable to migrate, as flood losses accumulate and reduce the set of livelihood alternatives (so-called 'trapped' populations). However, even when we increased access to credit, a commonly-proposed policy lever for incentivizing migration in the face of climate risk, we found that the number of immobile agents actually rose. These findings imply that instead of a straightforward relationship between displacement and migration, projections need to consider the multiple constraints on, and preferences for, mobility. Our model demonstrates that decision-makers seeking to affect migration outcomes around SLC would do well to consider individual-level adaptive behaviors and motivations that evolve through time, as well as the potential for unintended behavioral responses.

The serial millisecond crystallography instrument at the Australian Synchrotron incorporating the "Lipidico" injector.

A serial millisecond crystallography (SMX) facility has recently been implemented at the macromolecular crystallography beamline, MX2 at the Australian Synchrotron. The setup utilizes a combination of an EIGER X 16M detector system and an in-house developed high-viscosity injector, "Lipidico." Lipidico uses a syringe needle to extrude the microcrystal-containing viscous media and it is compatible with commercially available syringes. The combination of sample delivery via protein crystals suspended in a viscous mixture and a millisecond frame rate detector enables high-throughput serial crystallography at the Australian Synchrotron. A hit-finding algorithm, based on the principles of "robust-statistics," is employed to rapidly process the data. Here we present the first SMX experimental results with a detector frame rate of 100 Hz (10 ms exposures) and the Lipidico injector using a mixture of lysozyme microcrystals embedded in high vacuum silicon grease. Details of the experimental setup, sample injector, and data analysis pipeline are designed and developed as part of the Australian Synchrotron SMX instrument and are reviewed here.

A comparison of the visual symptoms between ADD/ADHD and normal children.

BACKGROUND: Attention Deficit Disorder (ADD) and Attention Deficit Hyperactivity Disorder (ADHD) are commonly diagnosed conditions that affect the lives of many individuals Diagnosis of ADD/ADHD is based primarily on observation, although more-objective tests are being developed. Ritalin is the most-popular treatment for ADD/ADHD. Literature indicates the ADD/ADHD patient may experience visual system dysfunctions. The purpose of this article is to document visual system symptoms that may coexist with treated ADD/ADHD. METHODS: Forty-three subjects were separated into two groups, which were matched for age and gender The experimental group had previously been diagnosed as ADD/ADHD and was under pharmacological treatment. The control group was comprised of non-ADD/ADHD children. A modified College of Optometrists in Vision Development (COVD) Quality of Life Outcomes Assessment was given to the parents of each child, which the child and parent completed together. The results between the experimental and control group were then compared. RESULTS: Results show that ADD/ADHD subjects report and/or experience more symptoms of visual system dysfunction than age-matched norms. Fourteen of the 33 symptoms were found to be significantly more severe in the ADD/ADHD group than in the control group. These symptoms were relatively evenly divided between four major symptom groups. CONCLUSIONS: ADD/ADHD children, even with current medical treatment, exhibit more visual and quality of life symptoms than do a similar group of non-ADD/ADHD children.

Characteristics of the Functional Independence Measure in traumatic spinal cord injury.

OBJECTIVES: The characteristics of the Functional Independence Measure (FIM) were examined for spinal cord injury (SCI) in regard to norms over time by level and completeness of injury, differential benefit of motor and cognition subscales, and "ceiling effect" after rehabilitation discharge. DESIGN: Descriptive study of raw FIM data collected prospectively at admission and discharge from acute inpatient rehabilitation, and at 1, 2, and 5 years after injury. SETTING: National Database of the 18 Spinal Cord Injury Model Systems. SUBJECTS: Persons with SCI, age 16 and over, with functionally complete injuries at inpatient rehabilitation admission (ASIA grades A, B, or C), admitted to Model System an average of 8 days after injury (standard deviation = 13, median = 1 day). Maximum sample sizes for which data were available were: at rehabilitation admission, 3,971 cases; at discharge, 4,033; at year 1 postinjury, 903; 2 years, 712; and 5 years, 570. OUTCOME MEASURES: The FIM motor and cognition subscales. RESULTS: There is a substantial ceiling effect of the FIM cognition items even by inpatient rehabilitation discharge, ie, 80% to 90% of the cases average 6 to 7 (independent or modified independence) across the 5 FIM cognition items. At 1 year 89% to 97% of cases were rated independent. FIM motor items were consistent with level of injury and neurologic status. Motor items (excluding locomotion items) were highly intercorrelated (correlations range from .58 to .92 for self care, sphincter control, and mobility items). Trends over years 1, 2, and 5 were stable for both motor and cognition subscales. FIM motor gains were greatest between admission and discharge and gains continued through 1 year after injury, but at a much-decreased rate. CONCLUSIONS: The cognition items are not informative for detecting changes over time in SCI; at best, these items could serve as a crude cognition screening assessment. Motor items, in contrast, appear to reflect well the functional status of individuals. High correlations among several of the motor items suggest item redundancy. FIM motor scores illustrated the improvements in neurologic and ASIA scores in appropriate cases. Individuals with ASIA impairment grades of B or C at admission make the most gains in FIM motor scores.

Cervical spine injuries in patients 65 and older.

STUDY DESIGN: This study was a retrospective data-base review of patients with cervical injuries admitted to a regional spinal cord injury center over a 9-year period. OBJECTIVES: Patients < 40 and > or = 65 were analyzed separately to determine differences in etiology, neurologic findings, mortality, and neurologic recovery. SUMMARY OF BACKGROUND DATA: Previous studies of cervical injuries in older patients have found a high percentage of falling as an etiology, a high incidence of injuries to C2, and a high mortality rate with spinal cord injury (SCI). METHODS: Three databases containing information on all SCI patients, SCI patients with 1-2 year follow-up, and neurogically intact spinal injury patients were reviewed retrospectively. RESULTS: A higher percentage of older patients had cervical injuries, and this group did not show the typical male predominance seen in young patients (4:1 vs. 1:1). Neurologic deficits were more common in the younger age group. In the older patients, falls were a much more common etiology, and upper cervical injuries, especially odontoid fractures, predominated. Cervical spondylosis and stenosis were more common in the older patients, and the mortality with associated SCI was 60 times higher than in younger patients. Younger patients more commonly had complete neurologic injuries, but had more early functional motor return in incomplete lesions. The older patients did show late functional return in incomplete deficits. CONCLUSIONS: Cervical spine injury commonly occurs with relatively minor trauma in patients > or = 65, with a mortality rate of approximately 26% with associated SCI. Return of functional motor recovery is delayed in older patients with incomplete deficits, but can be expected. C2 injuries, especially odontoid fractures, must be ruled out in older patients with neck pain after even a minor injury.