Characterization of Organosolv Lignins and Their Application in the Preparation of Aerogels

The production of novel materials and value-added chemicals from lignin has received considerable attention in recent years. Due to its abundant occurrence in nature, there is a growing interest in utilizing lignin as a feedstock for functional materials production, for example aerogels. Much like in the synthesis of phenol-based resins, the vacant ortho positions of the aromatic rings in lignin can crosslink with formaldehyde and form polymeric gels. After drying the hydrogels with supercritical CO₂, highly porous aerogels are obtained. Current study focuses on the preparation and thorough parametrization of organosolv lignins from different types of lignocellulosic biomass (aspen, pine, and barley straw) as well as their utilization for the preparation of lignin-5-methylresorcinol-formaldehyde aerogels. The thorough structural characterization of the obtained aerogels was carried out by gas adsorption, IR spectroscopy, and scanning electron microscopy. The obtained lignin-based monolithic mesoporous aerogels had specific surface areas and total pore volumes in the upward ranges of 450 m²/g and 1.4 cm³/g, respectively.     

Correlation of catheterized and clean catch urine protein/creatinine ratios in preeclampsia evaluation

OBJECTIVE: To examine whether clean catch urine specimens correlate with catheterized specimens for determination of protein/creatinine ratios in pregnant women being evaluated for preeclampsia. METHODS: Sixty pregnant women who were at least at 20 weeks of gestation were enrolled. Patients with ruptured membranes, vaginal bleeding, or urinary tract infections were excluded. Midstream clean catch urine specimens were collected. Catheterized specimens were then collected and used for clinical management. The specimens were analyzed for protein, creatinine, urinalysis, and culture. Based on sample size calculations, 60 participants were needed to detect a correlation of 0.90 with 80% power and alpha=0.05. RESULTS: Mean gestational age at enrollment was 35.9 weeks (range 23.1-41.7 weeks). Median (range) clean catch and catheterized protein/creatinine ratios were 0.204 (0.089-3.465) and 0.181 (0.067-3.335), respectively, with a correlation coefficient of 0.897 (P<.001). When results were categorized by degree of proteinuria using a cutoff of 0.3, sensitivity and specificity of the clean catch protein/creatinine ratios were 95.2% and 97.4%. When using a more conservative cutoff of 0.19, sensitivity and specificity of the clean catch protein/creatinine ratios were 96.4% and 75.0%. CONCLUSION: Clean catch and catheterized urine specimens correlate well in women with suspected preeclampsia. Routine catheterization of pregnant women is not necessary in the evaluation of preeclampsia.     

Food Frequency Questionnaires and Overnight Urines Are Valid Indicators of Daidzein and Genistein Intake in U.S. Women Relative to Multiple 24-h Urine Samples

Data regarding convenient, valid methods for measuring U.S. isoflavone intake are limited. We evaluated a soy food questionnaire (SFQ), the Willett food frequency questionnaire (FFQ), and overnight urine samples relative to excretion in 24-h urine samples. We also described intake among women in a high-risk program for breast or ovarian cancer. Between April 2002 and June 2003, 451 women aged 30 to 50 yr with a family history of breast or ovarian cancer completed the SFQ and FFQ. Of them, 27 provided four 24-h and overnight urine specimens. In these women, 24-h sample measures were correlated with SFQ estimates of daidzein (Spearman r = .48) and genistein (r = .54) intake, moderately correlated with the Willett FFQ (daidzein r = .38, genistein r = .33), and strongly correlated with overnight urine excretion (daidzein r = .84, genistein r = 0.93). Among all 451 SFQ respondents, mean (median) daidzein and genistein intakes were 2.8 (0.24) and 3.9 (0.30) mg/day. Primary sources of both were soymilk, soy nuts, and tofu. We conclude that targeted soy food questionnaires, comprehensive FFQs, and multiple overnight urines are all reasonable options for assessing isoflavone intake in epidemiologic studies.     

Brain Neurons Express Ornithine Decarboxylase‐Activating Antizyme Inhibitor 2 with Accumulation in Alzheimer's Disease

Polyamines are small cationic molecules that in adult brain are connected to neuronal signaling by regulating inward‐rectifier K⁺‐channels and different glutamate receptors. Antizyme inhibitors (AZINs) regulate the cellular uptake of polyamines and activate ornithine decarboxylase (ODC), the rate‐limiting enzyme of polyamine synthesis. Elevated levels of ODC activity and polyamines are detected in various brain disorders including stroke and Alzheimer''s disease (AD).We originally reported a novel brain‐ and testis‐specific AZIN, called AZIN2, the distribution of which we have now studied in normal and diseased human brain by in situ hybridization and immunohistochemistry. We found the highest accumulation of AZIN2 in a pearl‐on‐the‐string‐like distribution along the axons in both the white and gray matter. AZIN2 was also detected in a vesicle‐like distribution in the somas of selected cortical pyramidal neurons. Double‐immunofluorescence staining revealed co‐localization of AZIN2 and N‐methyl D‐aspartate‐type glutamate receptors (NMDARs) in pyramidal neurons of the cortex. Moreover, we found accumulation of AZIN2 in brains affected by AD, but not by other neurodegenerative disorders (CADASIL or Lewy body disease). ODC activity is mostly linked to cell proliferation, whereas its regulation by AZIN2 in post‐mitotically differentiated neurons of the brain apparently serves different purposes. The subcellular distribution of AZIN2 suggests a role in vesicular trafficking.     

Patients with premenstrual dysphoric disorder have increased startle response across both cycle phases and lower levels of prepulse inhibition during the late luteal phase of the menstrual cycle.

Patients with premenstrual dysphoric disorder (PMDD) experience their most intense symptoms during the late luteal phase. The aim of the current study was to compare acoustic startle response and prepulse inhibition in PMDD patients and controls during the follicular and late luteal phases of the menstrual cycle. Following two months of prospective daily ratings on the Cyclicity Diagnoser scale, 30 PMDD patients and 30 asymptomatic controls, between the ages of 20 and 46, were included in the study. The eyeblink component of the acoustic startle reflex was assessed using electromyographic measurements of m. orbicularis oculi. Twenty pulse-alone trials (115 dB 40 ms broad-band white noise) and 40 prepulse-pulse trials were presented. The prepulse stimuli consisted of a 115 dB 40 ms noise burst preceded at a 100 ms interval by 20 ms prepulses that were 72, 74, 78, or 86 dB. PMDD patients had a significantly higher startle response than controls during both phases of the menstrual cycle (p<0.05). PMDD patients exhibited lower levels of prepulse inhibition with 78 dB and 86 dB prepulses compared to control subjects in the luteal (p<0.01) but not in the follicular phase. Whereas control subjects displayed increased PPI during the late luteal phase compared to the follicular phase (p<0.01), PPI magnitude remained unchanged in PMDD patients between cycle phases. Relative to controls, PMDD patients displayed increased startle reactivity across both menstrual cycle phases and deficits in prepulse inhibition of acoustic startle during the late luteal phase. These findings are consistent with an altered response to ovarian steroids among PMDD patients.