Near‐infrared spectroscopic evaluation of lyophilized viral vaccine formulations

This article examines the applicability of near‐infrared spectroscopy (NIRS) to evaluate the virus state in a freeze‐dried live, attenuated vaccine formulation. Therefore, this formulation was freeze‐dried using different virus volumes and after applying different pre‐freeze‐drying virus treatments (resulting in different virus states): (i) as used in the commercial formulation; (ii) without antigen (placebo); (iii) concentrated via a centrifugal filter device; and (iv) stressed by 96 h exposure to room temperature. Each freeze‐dried product was measured directly after freeze‐drying with NIR spectroscopy and the spectra were analyzed using principal component analysis (PCA). Herewith, two NIR spectral regions were evaluated: (i) the 7300–4000 cm^?1 region containing the amide A/II band which might reflect information on the coated proteins of freeze‐dried live, attenuated viruses; and (ii) the C–H vibration overtone regions (10,000–7500 and 6340–5500 cm^?1) which might supply information on the lipid layer surrounding the freeze‐dried live, attenuated viruses. The different pre‐freeze‐drying treated live, attenuated virus formulations (different virus states and virus volumes) resulted in different clusters in the scores plots resulting from the PCA of the collected NIR spectra. Secondly, partial least squares discriminant analysis models (PLS‐DA) were developed and evaluated, allowing classification of the freeze‐dried formulations according to virus pretreatment. The results of this study suggest the applicability of NIR spectroscopy for evaluating live, attenuated vaccine formulations with respect to their virus pretreatment and virus volume. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29:1573–1586, 2013     

Gonadal steroids regulate the expression of aggrecanases in human endometrial stromal cells in vitro

The human endometrium undergoes cyclic change during each menstrual cycle in response to gonadal steroids. Proteolysis of endometrial extracellular matrix (ECM) is necessary to prepare this dynamic tissue for pregnancy. Proteolytic enzymes such as matrix metalloproteinase (MMP) and closely related a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) have been assigned key roles in the highly regulated cyclic remodelling of the endometrial ECM. We have previously shown that ADAMTS‐1 undergoes spatiotemporal changes in human endometrial stromal cells under the regulation of gonadal steroids. This suggests that other ADAMTS subtypes, known as aggrecanases, may contribute to the ECM remodelling events that occur in female physiological cycles and in preparation for pregnancy. To determine whether progesterone (P4), 17β‐estradiol (E2), or dihydrotestosterone (DHT), alone or in combination, are capable of regulating ADAMTS‐4, ‐5, ‐8 or ‐9 expression in human endometrial stromal cells in vitro. Real‐time quantitative PCR and Western blot analysis were used to measure ADAMTSs mRNA and protein levels in primary cultures of human endometrial stromal cells (n = 12). P4, DHT but not E2 have regulatory effects on ADAMTS‐8, ‐9 and ‐5 expression. Combined treatment with gonadal steroids did not show any synergistic or antagonistic effects. However, the synthetic steroid antagonists RU486 and hydroxyflutamide specifically inhibited the P4‐ or DHT‐mediated regulatory effects on ADAMTS expression. These studies provide evidence that the regulation of aggrecanases by gonadal steroids in human endometrial stromal cells may play an important role during decidualization.     

Cytochrome p450‐dependent disposition of the enantiomers of citalopram and its metabolites: In vivo studies in Sprague‐Dawley and Dark Agouti rats

The female Sprague‐Dawley (SD) and Dark Agouti (DA) rats are considered the animal counterparts of the human extensive and poor metabolizer cytochrome P450 (CYP) 2D6 phenotypes, respectively. The aim of this work was to study possible rat strain differences in the steady‐state pharmacokinetics of the (+)‐(S)‐ and (−)‐(R)‐enantiomers of citalopram and its demethylated metabolites. A chronic drug treatment regimen (15 mg/kg daily) was implemented for 13 days in separate groups of SD (n = 9) and DA (n = 9) rats by using osmotic pumps. The concentrations of citalopram and two major metabolites in serum and two brain regions were analyzed by an enantioselective high‐performance liquid chromatography assay. Higher serum and brain levels of citalopram and demethylcitalopram, but lower levels of didemethylcitalopram, were observed in DA rats when compared with SD rats. The enantiomeric (S/R) concentrations ratios of citalopram were lower in the DA rats when compared with the SD rats (0.53 ± 0.05 vs. 0.80 ± 0.03, P < 0.001), indicating a possibly decreased capacity in the metabolism of the (−)‐(R)‐enantiomer in the DA rats. This study shows that CYP2D deficiency results in steady‐state pharmacokinetic differences of the enantiomers of citalopram and its metabolites. Chirality, 2011. © 2010 Wiley‐Liss, Inc.     

Gene profiling of inflammatory genes in day 18 endometria from pregnant and non‐pregnant mares

Maternal recognition of pregnancy is a physiological process that primarily describes endometrial responses to a conceptus. Recognition of a conceptus prevents the release of prostaglandin F_2α, thereby ensuring survival of the corpus luteum and continued progesterone production. Exactly how this occurs in the mare is poorly understood. Because prostaglandin F_2α is a pro‐inflammatory hormone, we hypothesized that differential gene expression in the endometrium at the time of maternal recognition reflects an anti‐inflammatory event leading to decreased prostaglandin F_2α secretion. Mares were inseminated, and endometrial biopsies were recovered from pregnant mares on Day 18 post‐ovulation. In subsequent estrous cycles, mares were not inseminated and Day 18 post‐ovulation endometrial biopsies were collected (non‐pregnant control, matched per individual). Endometrial gene expression profiles were examined by screening an Affymetrix equine GeneChip containing probes specific for genes related to inflammatory processes. Microarray analysis revealed 118 genes that were up‐regulated and 93 genes that were down‐regulated (P < 0.001) at least 1.5‐fold in the endometrium of pregnant versus non‐pregnant mares. Quantitative, real‐time RT‐PCR confirmed the microarray results for three up‐regulated genes homologous to TSC22D3, PPAPDC2, and KLF6, and three down‐regulated genes homologous to ESR1, MARCKSL1, and EPSTI1 (P < 0.05). It is concluded that the presence of the equine embryo induces differential gene expression in the endometrium of Day 18 pregnant mares, and that these genes are associated with inflammatory processes and pathways involving cellular growth and proliferation. The results from this study provide important new insights into endometrial gene expression in response to early equine pregnancy. Mol. Reprod. Dev. 79: 777–784, 2012. © 2012 Wiley Periodicals, Inc.     

基于1H-NMR技术的肝癌尿液样品代谢组学研究

目的:探索区分健康对照组与肝癌患者的潜在标志代谢物。方法:运用SIMAC 13.0软件对对数据进行多元分析方法 PCA、PLS及OPLS的方法分析。结果:应用SPSS 21.0统计软件对其数据进行ROC曲线分析,发现肝癌患者在α-葡萄糖、β-葡萄糖和肌酸酐的代谢路径上都发生了一定的异常变化。这3个代谢物拟合综合变量的ROC曲线的AUC值为0.972(灵敏度为90.6%,特异性为92.9%),说明此代谢标记物组具有较高的诊断准确度。结论:α-葡萄糖、β-葡萄糖和肌酸酐可以作为区分健康对照人群与肝癌患者的潜在标志代谢物。     

Prokineticin 1 is up‐regulated by insulin in decidualizing human endometrial stromal cells

Prokineticin 1 (PROK1), a hypoxia‐regulated angiogenic factor, has emerged as a crucial regulator of embryo implantation and placentation. Dysregulation of PROK1 has been linked to recurrent pregnancy loss, pre‐eclampsia, foetal growth restriction and preterm birth. These pregnancy complications are common in women with obesity and polycystic ovary syndrome, i.e. conditions associated with insulin resistance and compensatory hyperinsulinaemia. We investigated the effect of insulin on PROK1 expression during in vitro decidualization. Endometrial stromal cells were isolated from six healthy, regularly menstruating women and decidualized in vitro. Insulin induced a significant dose‐dependent up‐regulation of PROK1 on both mRNA and protein level in decidualizing endometrial stromal cells. This up‐regulation was mediated by hypoxia‐inducible factor 1‐alpha (HIF1α) via the phosphatidylinositol 3‐kinase (PI3K) pathway. Furthermore, we demonstrated that PROK1 did not affect the viability, but significantly inhibited the migration of endometrial stromal cells and the migratory and invasive capacity of trophoblast cell lines. This in vitro study provides new insights into the regulation of PROK1 by insulin in human decidualizing endometrial stromal cells, the action of PROK1 on migration of endometrial stromal cells, as well as migration and invasion of trophoblasts. We speculate that hyperinsulinaemia may be involved in the mechanisms by which PROK1 is linked to placenta‐related pregnancy complications.     

Comprehensive plasma metabolomic and lipidomic analyses reveal potential biomarkers for heart failure

Heart failure is a syndrome with symptoms or signs caused by cardiac dysfunction. In clinic, four stages (A, B, C, and D) were used to describe heart failure progression. This study was aimed to explore plasma metabolomic and lipidomic profiles in different HF stages to identify potential biomarkers. Metabolomics and lipidomics were performed using plasma of heart failure patients at stages A (n?=?49), B (n?=?61), and C+D (n?=?26). Analysis of Variance (ANOVA) was used for screening dysregulated molecules. Bioinformatics was used to retrieve perturbed metabolic pathways. Univariate and multivariate receiver operating characteristic curve (ROC) analyses were used for potential biomarker screening. Stage A showed significant difference to other stages, and 142 dysregulated lipids and 134 dysregulated metabolites were found belonging to several metabolic pathways. Several marker panels were proposed for the diagnosis of heart failure stage A versus stage B-D. Several molecules, including lysophosphatidylcholine 18:2, cholesteryl ester 18:1, alanine, choline, and Fructose, were found correlated with B-type natriuretic peptide or left ventricular ejection fractions. In summary, using untargeted metabolomic and lipidomic profiling, several dysregulated small molecules were successfully identified between HF stages A and B-D. These molecules would provide valuable information for further pathological researches and biomarker development.

     

Chemodiversity of Essential Oils in Seseli libanotis (L.) W.D.J.Koch (Apiaceae) in Central Europe

Seseli libanotis is an aromatic umbelliferous plant distributed sporadically on dry grassland edges in Europe and Western Asia. The essential oil composition in the different plant parts was studied from plants collected on nine sites in Austria and one site in Alto Adige, Italy. Monoterpenes such as α‐pinene, sabinene and β‐myrcene and the sesquiterpene germacrene D were present in all essential oils from the aerial parts. Inflorescences and fruits had the highest essential oil contents. These essential oils from four sites were rich in acorenone B, while from other three sites they had carotol as a major component. Osthole as furocoumarin occurred in some oils. The root essential oils were dominated by α‐pinene. The essential oil variability has been studied by principal component analysis (PCA) and discriminant analysis (DA) with plant parts or sampling site as a priori groups. PCA could well separate inflorescence and fruit essential oil samples from leaf and stem essential oil samples. DA differentiated well between the plant parts and most of the sampling sites.     

体外受精-胚胎移植技术妊娠后流产的危险因素分析

目的:探讨体外受精-胚胎移植技术妊娠后流产的危险因素。方法:采用t检验、受试者工作特征曲线(Receiver operating characteristic curve,ROC曲线)以及二元Logistic回归分析分别对2015年1月至2017年12月我中心行体外受精-胚胎移植技术(In vitro fertilization and embryo transfer,IVF-ET)及卵胞浆内单精子注射技术(Intracytoplasmic sperm injection,ICSI)后妊娠的242例临床妊娠患者临床参数包括年龄、身体质量指数(Body mass index,BMI)、基础卵泡生成素(Follicle stimulating hormone,FSH)、黄体生成素(Luteinizing hormone,LH)、雌二醇(Estradiol,E2)水平、促性腺激素(Gonadotropins,Gn)总用量、Gn天数、人绒毛膜促性腺激素(Human choionic gonadotophin,HCG)日LH、E2、黄体酮(progesterone,P)水平、移植日子宫内膜厚度以及移植后14-16天血HCG浓度进行回顾性分析。结果:流产组与继续妊娠组年龄、移植后14-16天血HCG浓度分别31.44±4.40岁和29.59±3.94岁、396.96±377.66 IU/L和702.85±496.91 IU/L,差异具有统计学意义(P<0.05)。通过ROC曲线对各临床参数分析后求得各参数的cut-off值并以此为标准分组,结果显示不同年龄(29.41%和9.42%)以及移植后14-16天血HCG浓度(4.20%和22.76%)分组流产率比较差异具有显著的统计学意义(P<0.01)。二元Logistic回归分析上述参数与流产率的相关性,结果提示仅年龄、移植后14-16天血HCG水平与妊娠后流产率有显著相关性(P=0.01,P=0.001)。结论:年龄>33岁、移植后14-16天血HCG浓度≤582.6IU/L是IVF/ICSI妊娠后流产的独立危险因素,对此类患者进行治疗时应考虑到其流产的风险并提前采取预防措施避免不良妊娠结局。     

Lifestyle Intervention Decreases Urine Trimethylamine N‐Oxide Levels in Prepubertal Children with Obesity

Objective

Early lifestyle interventions in children with obesity decrease risk of obesity and metabolic disorders during adulthood. This study aimed to identify metabolic signatures associated with lifestyle intervention in urine samples from prepubertal children with obesity.

Methods

Thirty‐four prepubertal children with obesity were studied before and after a 6‐month lifestyle intervention program, and anthropometric, metabolic, and nutritional variables were collected. A nuclear magnetic resonance approach was applied to obtain the metabolomic profile from urine samples. Partial least squares‐discriminant analysis (PLS‐DA) was used to achieve group classification and variable importance on projection (VIP) for biomarker selection.

Results

The intervention reduced caloric intake by 10% (P < 0.05) and BMI standard deviation score by 0.47 SD (P < 0.001). PLS‐DA identified trimethylamine N‐oxide (TMAO, VIP = 2.21) as the metabolite with the highest discrimination properties between groups. Urine TMAO levels were reduced after the intervention (P < 0.05). TMAO is a biomarker of cardiovascular disease risk and is a product of gut microbiota‐dependent metabolism of certain dietary compounds, including choline. Notably, changes in TMAO levels after the intervention did not correlate to differences in choline intake but were inversely associated with fiber intake (P < 0.05).

Conclusions

These results indicate that lifestyle intervention decreases TMAO levels in children with obesity.

     

Diagnosis of early gastric cancer based on fluorescence hyperspectral imaging technology combined with partial‐least‐square discriminant analysis and support vector machine

This study investigated the feasibility of using fluorescence hyperspectral imaging technology to diagnose of early‐stage gastric cancer. Fluorescence spectral images of 76 patients who were pathologically diagnosed as non‐atrophic gastritis, premalignant lesions and gastric cancer were collected. Fluorescence spectra at 100‐pixel points were randomly extracted after binarization. Diagnostic models of non‐atrophic gastritis, premalignant lesions and gastric cancer were constructed through partial‐least‐square discriminant analysis (PLS‐DA) and support vector machine (SVM) algorithms. The prediction effects of PLS‐DA and SVM models were compared. Results showed that the average spectra of normal, precancerous and gastric cancer tissues significantly differed at 496, 546, 640 and 670 nm, and regular changes in fluorescence intensity at 546 nm were in the following order: normal > precancerous lesions > gastric cancer. Additionally, the effect of the diagnostic model established by SVM is significantly better than PLS‐DA which accuracy, specificity and sensitivity are above 94%. Experimental results revealed that the fast diagnostic model of early gastric cancer by combining fluorescence hyperspectral imaging technology and improved SVM was effective and feasible, thereby providing an accurate and rapid method for diagnosing early‐stage gastric cancer.      

FTIR spectroscopy for the detection and evaluation of live attenuated viruses in freeze dried vaccine formulations

This article examines the applicability of Fourier Transform Infrared (FTIR) spectroscopy to detect the applied virus medium volume (i.e., during sample filling), to evaluate the virus state and to distinguish between different vaccine doses in a freeze dried live, attenuated vaccine formulation. Therefore, different formulations were freeze dried after preparing them with different virus medium volumes (i.e., 30, 100, and 400 µl) or after applying different pre‐freeze‐drying sample treatments (resulting in different virus states); i.e., (i) as done for the commercial formulation; (ii) samples without virus medium (placebo); (iii) samples with virus medium but free from antigen; (iv) concentrated samples obtained via a centrifugal filter device; and (v) samples stressed by 96h exposure to room temperature; or by using different doses (placebo, 25‐dose vials, 50‐dose‐vials and 125‐dose vials). Each freeze‐dried product was measured directly after freeze‐drying with FTIR spectroscopy. The collected spectra were analyzed using principal component analysis (PCA) and evaluated at three spectral regions, which might provide information on the coated proteins of freeze dried live, attenuated viruses: (i) 1700–1600 cm^?1 (amide I band), 1600–1500 cm^?1 (amide II band) and 1200–1350 cm^?1 (amide III band). The latter spectral band does not overlap with water signals and is hence not influenced by residual moisture in the samples. It was proven that FTIR could distinguish between the freeze‐dried samples prepared using different virus medium volumes, containing different doses and using different pre‐freeze‐drying sample treatments in the amide III region. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 31:1107–1118, 2015     

Rat brain monoamine and serotonin S2 receptor changes during pregnancy

The concentrations of noradrenaline (NA), dopamine (DA), serotonin (5-HT), and their metabolites were determined in 5 brain areas of non-pregnant, 15 and 20 day pregnant and 4 day post-partum rats. Striatal 5-HT content was significantly lower in 15 and 20 day pregnant rats than in estrous controls. A significant decrease in striatal and frontal cortex 5-hydroxyindole-3-acetic acid (5-HIAA) concentration was observed in 15 day pregnant rats. Significant increases in hypothalamic and hippocampal NA levels were observed at 4 days post-partum. Frontal cortex serotonin S2 receptorKd was reduced in 4 day post-partum rats. There was no significant change in S2 receptorB _max during pregnancy. Levels of progesterone were negatively correlated with striatal DA, homovanillic acid (HVA), 5-HT, and 5-HIAA levels, hypothalamic DA, hippocampal 5-HT, and frontal cortex 5-HIAA values as well as striatal HVA to DA, and HVA to 3,4-dihydroxyphenylacetic acid (DOPAC) ratios and amygdaloid HVA to DOPAC ratios. The limbic neurotransmitter changes might possibly contribute to mood changes which occur during pregnancy and post-partum.     

Essential‐Oil Variability in Natural Populations of Pinus mugo Turra from the Julian Alps

The composition and variability of the terpenes and their derivatives isolated from the needles of a representative pool of 114 adult trees originating from four natural populations of dwarf mountain pine (Pinus mugo Turra ) from the Julian Alps were investigated by GC‐FID and GC/MS analyses. In total, 54 of the 57 detected essential‐oil components were identified. Among the different compound classes present in the essential oils, the chief constituents belonged to the monoterpenes, comprising an average content of 79.67% of the total oil composition (74.80% of monoterpene hydrocarbons and 4.87% of oxygenated monoterpenes). Sesquiterpenes were present in smaller amounts (average content of 19.02%), out of which 16.39% were sesquiterpene hydrocarbons and 2.62% oxygenated sesquiterpenes. The most abundant components in the needle essential oils were the monoterpenes δ‐car‐3‐ene, β‐phellandrene, α‐pinene, β‐myrcene, and β‐pinene and the sesquiterpene β‐caryophyllene. From the total data set of 57 detected compounds, 40 were selected for principal‐component analysis (PCA), discriminant analysis (DA), and cluster analysis (CA). The overlap tendency of the four populations suggested by PCA, was as well observed by DA. CA also demonstrated similarity among the populations, which was the highest between Populations I and II.     

Validation of an Ultrasound‐Guided Technique to Establish a Liver‐to‐Coelom Ratio and a Comparative Analysis of the Ratios Among Acclimated and Recently Wild‐Caught Southern Stingrays,Dasyatis Americana

Southern stingrays, Dasyatis americana, are a well‐represented elasmobranch species in public aquaria and other facilities throughout the world. This study was conducted at a facility that experienced some mortality and replenished the collection with wild‐caught stingrays. A common necropsy finding among the stingrays was a small, dark liver. The objectives of this study were to assess the reliability of an ultrasound‐guided technique for establishing a liver‐to‐coelom ratio by calculating the approximate length of the liver with respect to the coelomic cavity length and then to compare ratios between acclimated captive and wild‐caught stingrays. The ultrasound validation phase of the study measured the distance from the caudal margin of the liver to the pelvic cartilaginous girdle and compared it to the actual distance measured during the necropsy or surgery. There was no significant difference found between the ultrasound and actual distance measurements (P = 0.945). This technique was then used to establish liver‐to‐coelom ratios and compare two groups of stingrays, presumably under different metabolic states at different periods. Liver‐to‐coelom ratios were established during initial examinations as well as 8 months after cohabitation in a touch pool exhibit. There were significant differences in liver‐to‐coelom ratios between the two stingray groups at introduction (median difference = 30.9%, P = 0.007) and after 8 months (median difference = 20.5%, P = 0.008). There were also significant differences in the liver‐to‐coelom ratios within each group at introduction and at 8 months (acclimated group median difference = 20.4%, P = 0.018; wild‐caught group median difference 31%, P = 0.008). Zoo Biol. 32:104‐111, 2013. © 2012 Wiley Periodicals, Inc.     

The Impact of Endometrial Thickness on the Day of Human Chorionic Gonadotrophin (hCG) Administration on Ongoing Pregnancy Rate in Patients with Different Ovarian Response

In order to explore the impact of endometrial thickness on hCG administration day on ongoing pregnancy rate (OPR) in IVF-ET cycles, we retrospectively analyzed data from 10,406 patients undergoing their first IVF cycles with standard gonadotropin releasing hormone analogue (GnRH-a) long protocol. Firstly, patients were divided into poor (≤ 5 oocytes), medium (6–14 oocytes), and high (≥ 15 oocytes) ovarian responders based on the number of oocytes retrieved. In each group, patients were sub-divided into three groups according to the endometrial thickness on the day of hCG administration: Group A, thin endometrial thickness (≤ 7 mm); Group B, medium endometrial thickness (8–13 mm); Group C, thick endometrial thickness (≥ 14 mm). (1) For poor responders, OPRs were significantly different in the three endometrial thickness groups (28.57%, 44.25%, and 51.34%; P = 0.008). The association between thin endometrial thickness and OPR was significant after controlling for age, number of embryos transferred by multivariate logistic regression analysis (adjusted OR: 0.408; 95% CI: 0.186–0.898; P = 0.026. Reference = thick endometrial thickness). (2) For medium responders, OPRs were 31.58%, 55.56%, and 63.01% (P = 0.000) in the three groups. Adjusted OR for thin endometrial thickness was 0.284 (95% CI: 0.182–0.444; P = 0.000). (3) For high responders, OPRs were also significantly different in the three groups (28.13%, 52.63%, and 63.18; P = 0.000). Adjusted OR for thin endometrial thickness was 0.233 (95% CI: 0.105–0.514; P = 0.000). For patients undergoing IVF with different ovarian response, a thin endometrium on the day of hCG administration adversely affects ongoing pregnancy rate.     

Regional alterations of dopamine and its metabolites in rat brain following portacaval anastomosis

Hyperammonemia and changes in brain monoamine metabolism have been proposed to contribute to the pathogenesis of the neuropsychiatric symptoms characteristic of human portal-systemic encephalopathy (PSE) resulting from chronic liver disease. Portacaval anastomosis (PCA) in the rat leads to sustained hyperammonemia and mild encephalopathy. In order to evaluate the role of dopamine (DA) metabolism in PSE, levels of DA and its metabolites were measured by HPLC with electrochemical detection in brain regions of rats with PCA at various stages of encephalopathy precipitated by ammonium acetate administration. Following ammonium acetate administration, rats with PCA rapidly develop severe neurological signs of encephalopathy progressing through loss of righting reflex to coma; sham-operated control animals administered ammonium acetate showed no such neurological deterioration. Concentrations of the DA metabolites DOPAC and HVA as well as [DA metabolites]/[DA] ratios, an indirect measure of DA turnover in brain, were increased in caudate-putamen, in cingulate and pyriform entorhinal cortices as well as in raphe nucleus and locus coeruleus. Increased DA metabolites, however, did not worsen at coma states of PSE. Increased DA turnover thus appears to relate to early neuropsychiatric and extrapyramidal symptoms of PSE.     

INTERCOLONIAL VARIABILITY IN MACROMOLECULAR COMPOSITION IN P‐STARVED AND P‐REPLETE SCENEDESMUS POPULATIONS REVEALED BY INFRARED MICROSPECTROSCOPY1

Macromolecular variability in microalgal populations subject to different nutrient environments was investigated, using the chlorophyte alga Scenedesmus quadricauda (Turpin) Bréb. as a model organism. The large size of the four‐cell coenobia in the strain used in this study (～35 μm diameter) conveniently allowed high quality spectra to be obtained from individual coenobia using a laboratory‐based Fourier transform infrared (FTIR) microscope with a conventional globar source of IR. By drawing sizable subpopulations of coenobia from two Scenedesmus cultures grown under either nutrient‐replete or P‐starved conditions, the population variability in macromolecular composition, and the effects of nutrient change upon this, could be estimated. On average, P‐starved coenobia had higher carbohydrate and lower protein absorbance compared with P‐replete coenobia. These parameters varied between coenobia with histograms of the ratio of absorbance of the largest protein and carbohydrate bands being Gaussian distributed. Distributions for the P‐replete and P‐starved subpopulations were nonoverlapping, with the difference in mean ratios for the two populations being statistically significant. Greater variance was observed in the P‐starved subpopulation. In addition, multivariate models were developed using the spectral data, which could accurately predict the nutrient status of an independent individual coenobium, based on its FTIR spectrum. Partial least squares discriminant analysis (PLS‐DA) was a better prediction method compared with soft independent modeling by class analogy (SIMCA).     

NIR Spectroscopy Applications in the Development of a Compacted Multiparticulate System for Modified Release

The purpose of this study was to utilize near-infrared spectroscopy and chemical imaging to characterize extrusion-spheronized drug beads, lipid-based placebo beads, and modified release tablets prepared from blends of these beads. The tablet drug load (10.5–19.5 mg) of theophylline (2.25 mg increments) and cimetidine (3 mg increments) could easily be differentiated using univariate analyses. To evaluate other tablet attributes (i.e., compression force, crushing force, content uniformity), multivariate analyses were used. Partial least squares (PLS) models were used for prediction and principal component analysis (PCA) was used for classification. The PLS prediction models (R ² > 0.98) for content uniformity of uncoated compacted theophylline and cimetidine beads produced the most robust models. Content uniformity data for tablets with drug content ranging between 10.5 and 19.5 mg showed standard error of calibration (SEC), standard error of cross-validation, and standard error of prediction (SEP) values as 0.31, 0.43, and 0.37 mg, and 0.47, 0.59, and 0.49 mg, for theophylline and cimetidine, respectively, with SEP/SEC ratios less than 1.3. PCA could detect blend segregation during tableting for preparations using different ratios of uncoated cimetidine beads to placebo beads (20:80, 50:50, and 80:20). Using NIR chemical imaging, the 80:20 formulations showed the most pronounced blend segregation during the tableting process. Furthermore, imaging was capable of quantitating the cimetidine bead content among the different blend ratios. Segregation testing (ASTM D6940-04 method) indicated that blends of coated cimetidine beads and placebo beads (50:50 ratio) also tended to segregate.