Spectrometric Analysis of Dantrolene Sodium.

Dantrolene sodium is a direct-acting skeletal muscle relaxant. Dantrolene sodium for injection is indicated, along with suitable supportive measures, for the management of sudden, severe hypermetabolism of skeletal muscle typical of malignant hyperthermia crises in patients of any age. The formulation scanned in this work was designed to be injected intravenously. Intra-lot and inter-lot variability in the spectra of REVONTO™ (dantrolene sodium) was measured in the Drug Quality Study (DQS) using Fourier transform near-infrared spectrometry (FTNIR). Spectra of 69 vials from lot 20REV01A contained two groups (n1=56 vials, n2=13 vials) when scanned with an FTNIR. The two groups of spectra in lot 20REV01A were found to be 66.7 SDs apart using a subcluster detection test, suggesting that the two groups were manufactured differently. As a result, all available samples of dantrolene were examined. A library of spectra of 141 vials of dantrolene from 4 lots were found to contain 3 separate groups, also suggesting that different vials contain different materials.

Quality Variations in Thyrotropin Alfa.

Thyrotropin alfa is a heterodimeric glycoprotein containing human thyroid stimulating hormone (TSH). It is used as an adjunctive diagnostic tool for serum thyroglobulin (Tg) testing with or without radioiodine imaging in the follow-up of patients with well-differentiated thyroid cancer who have previously undergone thyroidectomy. Inter-lot variability in the Fourier transform near-infrared spectra of 30 samples obtained from four separate lots of Thyrogen® was detected in the Drug Quality Study (DQS). The vials fell into two distinct groups (rtst = 0.90, rlim= 0.98, p=0.02). In addition, one vial of the 30 (3%) appeared 4.7 multidimensional SDs from all of the other vials, suggesting that it also represents a different material.

Spectral Intra-Lot and Inter-Lot Variability in Carfilzomib.

Carfilzomib is a prescription injectable drug approved for use by the FDA as an antineoplastic agent, part of a drug class of medications known as proteasome inhibitors, and used to stop and slow the growth and progression of cancer cells within the body. The drug is approved as an agent to treat multiple myeloma. It is provided as a single-use vial that contains 60 mg of carfilzomib as a sterile, white to off-white lyophilized cake or powder. Intra-lot and inter-lot variability in the spectra of carfilzomib vials was detected in the Drug Quality Study (DQS) using Fourier transform near-infrared spectrometry (FTNIR). One of 12 vials of lot 1143966 manufactured for Onyx Pharmaceuticals, Inc. appeared 4.7 multidimensional standard deviations (SDs) from the other 11 vials in a 3-D space formed by the first 3 principal components, which captured 81% of the total spectral variation. Spectra of 168 vials from 18 lots in the spectral library formed two groups in the 3-D space formed by the first 3 principal components. One group contained 155 vials and the other group contained 13 vials. The 2 groups had different locations and scales using a subcluster detection test at p=0.02.

Potential Process Control Issues with Pemetrexed.

Pemetrexed is a folate analog metabolic inhibitor used in treatment of locally advanced or metastatic nonsquamous non-small cell lung cancer and for mesothelioma. Intra-lot and inter-lot variability in the spectra of ALIMTA® was detected in the Drug Quality Study (DQS) using Fourier transform near-infrared spectrometry (FTNIR). One vial of 12 (8%) sampled from lot S20I013A appeared 3.0 multidimensional SDs from the other vials, suggesting that it represents a different material. Consequently, additional spectra from other lots were analyzed. Spectra of 147 vials from 23 lots in the spectral library contained 14 vials that were outside the main group (26.4 SDs using a subcluster detection test), suggesting that the 14 library vials (9.5% of the total) also contain differing materials.

Bridging integrator 1 (BIN1) protein expression increases in the Alzheimer's disease brain and correlates with neurofibrillary tangle pathology.

Recent genome wide association studies have implicated bridging integrator 1 (BIN1) as a late-onset Alzheimer's disease (AD) susceptibility gene. There are at least 15 different known isoforms of BIN1, with many being expressed in the brain including the longest isoform (iso1), which is brain-specific and localizes to axon initial segments and nodes of Ranvier. It is currently unknown what role BIN1 plays in AD. We analyzed BIN1 protein expression from a large number (n = 71) of AD cases and controls from five different brain regions (hippocampus, inferior parietal cortex, inferior temporal cortex, frontal cortex (BA9), and superior and middle temporal gyri). We found that the amount of the largest isoform of BIN1 was significantly reduced in the AD brain compared to age-matched controls, and smaller BIN1 isoforms were significantly increased. Further, BIN1 was significantly correlated with the amount of neurofibrillary tangle (NFT) pathology but not with either diffuse or neuritic plaques, or with the amount of amyloid-ß peptide. BIN1 is known to be abnormally expressed in another human disease, myotonic dystrophy, which also features prominent NFT pathology. These data suggest that BIN1 is likely involved in AD as a modulator of NFT pathology, and that this role may extend to other human diseases that feature tau pathology.

Obesity and diabetes cause cognitive dysfunction in the absence of accelerated ß-amyloid deposition in a novel murine model of mixed or vascular dementia.

Mid-life obesity and type 2 diabetes mellitus (T2DM) confer a modest, increased risk for Alzheimer's disease (AD), though the underlying mechanisms are unknown. We have created a novel mouse model that recapitulates features of T2DM and AD by crossing morbidly obese and diabetic db/db mice with APPΔNL/ΔNLx PS1P264L/P264L knock-in mice. These mice (db/AD) retain many features of the parental lines (e.g. extreme obesity, diabetes, and parenchymal deposition of ß-amyloid (Aß)). The combination of the two diseases led to additional pathologies-perhaps most striking of which was the presence of severe cerebrovascular pathology, including aneurysms and small strokes. Cortical Aß deposition was not significantly increased in the diabetic mice, though overall expression of presenilin was elevated. Surprisingly, Aß was not deposited in the vasculature or removed to the plasma, and there was no stimulation of activity or expression of major Aß-clearing enzymes (neprilysin, insulin degrading enzyme, or endothelin-converting enzyme). The db/AD mice displayed marked cognitive impairment in the Morris Water Maze, compared to either db/db or APPΔNLx PS1P264L mice. We conclude that the diabetes and/or obesity in these mice leads to a destabilization of the vasculature, leading to strokes and that this, in turn, leads to a profound cognitive impairment and that this is unlikely to be directly dependent on Aß deposition. This model of mixed or vascular dementia provides an exciting new avenue of research into the mechanisms underlying the obesity-related risk for age-related dementia, and will provide a useful tool for the future development of therapeutics.

Leptin regulates amyloid ß production via the γ-secretase complex.

Alzheimer's disease (AD) is the most common age-related neurodegenerative disease, affecting an estimated 5.3million people in the United States. While many factors likely contribute to AD progression, it is widely accepted that AD is driven by the accumulation of ß-amyloid (Aß), a small, fibrillogenic peptide generated by the sequential proteolysis of the amyloid precursor protein by the ß- and γ-secretases. Though the underlying causes of Aß accumulation in sporadic AD are myriad, it is clear that lifestyle and overall health play a significant role. The adipocyte-derived hormone leptin has varied systemic affects, including neuropeptide release and neuroprotection. A recent study by Lieb et al. (2009) showed that individuals with low plasma leptin levels are at greater risk of developing AD, through unknown mechanisms. In this report, we show that plasma leptin is a strong negative predictor of Aß levels in the mouse brain, supporting a protective role for the hormone in AD onset. We also show that the inhibition of Aß accumulation is due to the downregulation of transcription of the γ-secretase components. On the other hand, ß-secretase expression is either unchanged (BACE1) or increased (BACE2). Finally, we show that only presenilin 1 (PS1) is negatively correlated with plasma leptin at the protein level (p<0.0001). These data are intriguing and may highlight a role for leptin in regulating the onset of amyloid pathology and AD.