bluuebunny/crossref_metadata_2025 huggingface dataset:
Sweet Thermal Taste: Perceptual Characteristics in Water and Dependence on TAS1R2/TAS1R3
Authors: Nachtigal Danielle , Green Barry G
Published: February 2020

The initial objective of this study was to determine if activation of the sweet taste receptor TAS1R2/TAS1R3 is necessary for perception of sweet thermal taste (swTT). Our approach was to inhibit the receptor with the inverse agonist lactisole using a temperature-controlled flow gustometer. Because all prior studies of thermal taste (TT) used metal thermodes to heat the tongue tip, we first investigated whether it could be generated in heated water. Experiment 1 showed that sweetness could be evoked when deionized water was heated from 20 to 35 °C, and testing with static temperatures between 20 and 35 °C demonstrated the importance of heating from a cool temperature. As in previous studies, thermal sweetness was reported by only a subset of participants, and replicate measurements found variability in reports of sweetness across trials and between sessions. Experiment 2 then showed that exposure to 8 mM lactisole blocked perception of swTT. Confirmation of the involvement of TAS1R2/TAS1R3 led to an investigation of possible sensory and cognitive interactions between thermal and chemical sweetness. Using sucrose as a sweet stimulus and quinine as a nonsweet control, we found that dynamic heating capable of producing thermal sweetness did not increase the sweetness of sucrose compared with static heating at 35 °C. However, swTT was disrupted if trials containing sucrose (but not quinine) were interspersed among heating-only trials. These findings provide new information relevant to understanding the perceptual processes and receptor mechanisms of swTT, as well as the heat sensitivity of sweet taste in general.
The Natural History of Anal High-grade Squamous Intraepithelial Lesions in Gay and Bisexual Men
Authors: Poynten I Mary , Jin Fengyi , Roberts Jennifer M , Templeton David J , Law Carmella , Cornall Alyssa M , Molano Monica , Machalek Dorothy A , Carr Andrew , Farnsworth Annabelle , Tabrizi Sepehr , Phillips Samuel , Fairley Christopher K , Garland Suzanne M , Hillman Richard J , Grulich Andrew E
Published: February 2020

Background

Gay and bisexual men (GBM) are disproportionately affected by anal cancer. Prevention is hindered by incomplete understanding of the natural history of its precursor, anal high-grade squamous intraepithelial lesions (HSIL).

Methods

The Study of the Prevention of Anal Cancer, conducted between 2010 and 2018, enrolled human immunodeficiency virus (HIV)-positive and HIV-negative GBM aged ≥35 years. Anal cytology and high-resolution anoscopy (HRA) were performed at baseline and 3 annual visits. A composite HSIL diagnosis (cytology ± histology cHSIL) was used. Cytological high-grade squamous intraepithelial lesions (cHSIL) incidence and clearance rates were calculated with 95% confidence intervals (CIs). Predictors were calculated using Cox regression with hazard ratios (HRs) and 95% CIs.

Results

Among 617 men, 220 (35.7%) were HIV-positive, median age 49 years. And 124 incident cHSIL cases occurred over 1097.3 person-years (PY) follow-up (11.3, 95% CI 9.5–13.5 per 100 PY). Significant bivariate predictors of higher incidence included age <45 years (HR 1.64, 95% CI 1.11–2.41), HIV positivity (HR 1.43, 95% CI .99–2.06), prior SIL diagnosis (P-trend < .001) and human papillomavirus (HPV)16 (HR 3.39, 2.38–4.84). Over 695.3 PY follow-up, 153 cHSIL cleared (clearance 22.0, 95% CI 18.8–25.8 per 100 PY). Predictors were age < 45 years (HR 1.52, 1.08–2.16), anal intraepithelial neoplasia (AIN)2 rather than AIN3 (HR 1.79, 1.29–2.49), smaller lesions (HR 1.62, 1.11–2.36) and no persistent HPV16 (HR 1.72, 1.23–2.41). There was 1 progression to cancer (incidence 0.224, 95% CI .006–1.25 per 100 PY).

Conclusion

These data strongly suggest that not all anal HSIL detected in screening requires treatment. Men with persistent HPV16 were less likely to clear HSIL and are more likely to benefit from effective HSIL treatments.

Clinical Trials Registration

Australia New Zealand Clinical Trials Registry (ANZCTR365383).
The choice of targets and ligands for site-specific delivery of nanomedicine to atherosclerosis
Authors: Zia Adil , Wu Yuao , Nguyen Tuan , Wang Xiaowei , Peter Karlheinz , Ta Hang T
Published: February 2020

As nanotechnologies advance into clinical medicine, novel methods for applying nanomedicine to cardiovascular diseases are emerging. Extensive research has been undertaken to unlock the complex pathogenesis of atherosclerosis. However, this complexity presents challenges to develop effective imaging and therapeutic modalities for early diagnosis and acute intervention. The choice of ligand-receptor system vastly influences the effectiveness of nanomedicine. This review collates current ligand-receptor systems used in targeting functionalized nanoparticles for diagnosis and treatment of atherosclerosis. Our focus is on the binding affinity and selectivity of ligand-receptor systems, as well as the relative abundance of targets throughout the development and progression of atherosclerosis. Antibody-based targeting systems are currently the most commonly researched due to their high binding affinities when compared with other ligands, such as antibody fragments, peptides, and other small molecules. However, antibodies tend to be immunogenic due to their size. Engineering antibody fragments can address this issue but will compromise their binding affinity. Peptides are promising ligands due to their synthetic flexibility and low production costs. Alongside the aforementioned binding affinity of ligands, the choice of target and its abundance throughout distinct stages of atherosclerosis and thrombosis is relevant to the intended purpose of the nanomedicine. Further studies to investigate the components of atherosclerotic plaques are required as their cellular and molecular profile shifts over time.
Is Therapeutic Drug Monitoring for Anti-tumour Necrosis Factor Agents in Adults With Inflammatory Bowel Disease Ready for Standard of Care? A Systematic Review and Meta-analysis
Authors: Shah Raj , Hoffman Gila R , El-Dallal Mohammed , Goldowsky Alexander M , Chen Ye , Feuerstein Joseph D
Published: February 2020

Introduction

Using therapeutic drug monitoring [TDM] in adult patients with inflammatory bowel disease [IBD] remains controversial. We conducted a systematic review and meta-analysis to answer four clinical PICO [Population, Intervention, Comparator, Outcome] questions.

Methods

We searched MEDLINE, Embase, Web of Science, and Cochrane Central from inception to June 30, 2019. Remission was defined by the manuscripts’ definitions of clinical remission. Data were analysed using RevMan 5.3. Quality of evidence was assessed with GRADE methodology.

Results

We identified and screened 3365 abstracts and 11 articles. PICO 1 Reactive vs No TDM: six studies pooled showed 57.1% [257/450] failed to achieve remission following reactive TDM vs 44.7% [268/600] in the no TDM group (risk ratio [RR]: 1.14; 95% confidence interval [CI] 0.88–1.47). PICO 2 Proactive vs no TDM: five studies pooled showed 19.5% [75/384] failed to maintain remission in the proactive TDM group vs 33.4% [248/742] in the no TDM group [RR: 0.60; 95% CI 0.35–1.04]. PICO 3 Proactive vs Reactive TDM: two retrospective studies pooled showed 14.2% [26/183] failure to maintain remission in the proactive TDM group and 64.7% [119/184] in the reactive TDM group [RR: 0.22; 95% CI 0.15–0.32]. PICO 4 TDM [proactive/reactive] vs No TDM: we pooled 10 studies showing 39.7% [332/837] failed to achieve remission in the TDM [proactive/reactive] cohort vs 40.3% [428/1063] in the no TDM cohort [RR: 0.94; 95% CI 0.77–1.14]. Overall, the quality of evidence in each PICO was very low when using GRADE.

Conclusions

This meta-analysis shows that data supporting use of TDM in adults are limited and of very low quality. Further well-designed randomized controlled trials are needed to determine the place of TDM in clinical practice.
Multiple left-sided stenotic lesions: outcomes after mitral valve surgery. Arguments for abandoning the eponym ‘Shone syndrome’
Authors: Perrier Stephanie L , Jadhav Mangesh , d’Udekem Yves , Brink Johann , Konstantinov Igor E , Zannino Diana , Cheung Michael M , Brizard Christian P
Published: February 2020

OBJECTIVES

Management of patients with left ventricular inflow and outflow stenotic lesions can be challenging. Our purpose was to characterize such patients and review the long-term outcomes of those requiring mitral valve (MV) surgery.

METHODS

We performed a retrospective study of 40 patients with subaortic, aortic and/or arch stenotic lesion(s) who underwent MV surgery between 1985 and 2016.

RESULTS

Associated left-sided stenotic lesions included aortic valve stenosis in 20 patients (50%), subaortic stenosis in 19 (47.5%) patients, coarctation in 23 (57.5%) patients and hypoplastic aortic arch in 16 (40%) patients. Nineteen patients (47.5%) had a supravalvular mitral ring and 15 (37.5%) patients had a parachute MV. The overall mortality rate was 32.5% (13 patients) with a mean follow-up of 16.3 ± 1.8 years. Being <6 months of age at the time of MV surgery (P = 0.02) and having had previous neonatal aortic valve and/or arch surgery (P = 0.01) were associated with death. The incidence of reoperation (95% confidence interval) at 1, 5, 10 and 15 years was 38% (23–53%), 54% (38–70%), 68% (53–84%) and 85% (72–98%), respectively.

CONCLUSIONS

Results after MV surgery for children with associated left-sided stenotic lesions are closely age-related. The need for mitral intervention shortly after the initial aortic valve and/or arch intervention was a predictor of dismal outcomes
Watch-and-wait strategy for type A intramural haematoma and acute aortic dissection with thrombosed false lumen of the ascending aorta: a Japanese single-centre experience
Authors: Kitamura Tadashi , Torii Shinzo , Miyamoto Takashi , Mishima Toshiaki , Ohkubo Hirotoki , Fujioka Shunichiro , Yakuwa Kazuki , Araki Haruna , Kondo Shin , Tamura Yoshimi , Tadokoro Yuki , Onishi Yoshihiko , Miyaji Kagami
Published: February 2020

OBJECTIVES

In this study, we investigated the early and midterm outcomes of initial watch-and-wait strategy for Stanford type A intramural haematoma and acute aortic dissection with thrombosed false lumen of the ascending aorta in patients with a maximum aortic diameter of ≤50 mm, pain score of ≤3/10 and no ulcer-like projection in the ascending aorta.

METHODS

Inpatient and outpatient records were retrospectively reviewed.

RESULTS

Of the 81 patients with type A intramural haematoma and acute aortic dissection with the thrombosed false lumen of the ascending aorta between April 2011 and April 2019, a watch-and-wait strategy was selected in 46 patients. The mean age of the patients was 68 years, and 22 (48%) patients were female. Ten patients underwent emergency pericardial drainage for cardiac tamponade at the time of presentation and 8 patients underwent aortic repair during hospitalization for new ulcer-like projection, re-dissection or rupture. In-hospital mortality occurred in 2 (4%) patients. During follow-up, survival at 1 and 2 years was 95% and 92%, respectively. There was no significant difference in survival or aortic events between patients in whom the watch-and-wait strategy and emergency surgical treatment were indicated.

CONCLUSIONS

The early and midterm outcomes of the initial watch-and-wait strategy were favourable for type A intramural haematoma and acute aortic dissection with the thrombosed false lumen of the ascending aorta in Japanese patients with a maximum aortic diameter of ≤50 mm, pain score of ≤3/10 and no ulcer-like projection. Further study is required to show the safety of this strategy.
Borders as opposed to so-called geography: which should be used to classify isolated ventricular septal defects?
Authors: Edgar Laura J , Anderson Robert H , Stickley John , Crucean Adrian
Published: February 2020

OBJECTIVES

Ventricular septal defects can be classified according to their borders or according to the fashion in which they open to the right ventricle, so-called geography. As yet, there is no consensus as to how they should be classified. In an attempt to achieve agreement, the International Society for Nomenclature of Congenital and Paediatric Heart Disease, in 2018, proposed a system incorporating both approaches. We have assessed the subjectivity of their suggested terms hoping to determine their suitability in the desired universal system for classification.

METHODS

We examined 212 specimens held in the archive of Birmingham Women’s and Children’s Hospital. Each defect was described by 3 independent examiners on the basis of borders and their relationship to the landmarks of the right ventricle. The interobserver agreement was then calculated using Fleiss' method.

RESULTS

Calculations to assess interobserver agreement showed that the examiners were more likely to agree on the borders of the defects than their so-called geography (κ = 0.804 vs κ = 0.518). The landmarks of the right ventricle proved to be highly variable such that the application of ‘geographic’ terms to hearts with perimembranous defects proved particularly challenging.

CONCLUSIONS

Interobserver agreement is lower when using terms based on ‘geography’ as opposed to borders. Whilst providing important morphological detail, the terms based on right ventricular landmarks are highly subjective. They should not be prioritized in a universal system of classification. Instead, the defects can be classified simply by using ‘perimembranous’, ‘muscular’, or ‘doubly committed and juxta-arterial’ as first-order terms.
The haemochromatosis gene Hfe and Kupffer cells control LDL cholesterol homeostasis and impact on atherosclerosis development
Authors: Demetz Egon , Tymoszuk Piotr , Hilbe Richard , Volani Chiara , Haschka David , Heim Christiane , Auer Kristina , Lener Daniela , Zeiger Lucas B , Pfeifhofer-Obermair Christa , Boehm Anna , Obermair Gerald J , Ablinger Cornelia , Coassin Stefan , Lamina Claudia , Kager Juliane , Petzer Verena , Asshoff Malte , Schroll Andrea , Nairz Manfred , Dichtl Stefanie , Seifert Markus , von Raffay Laura , Fischer Christine , Barros-Pinkelnig Marina , Brigo Natascha , Valente de Souza Lara , Sopper Sieghart , Hirsch Jakob , Graber Michael , Gollmann-Tepeköylü Can , Holfeld Johannes , Halper Julia , Macheiner Sophie , Gostner Johanna , Vogel Georg F , Pechlaner Raimund , Moser Patrizia , Imboden Medea , Marques-Vidal Pedro , Probst-Hensch Nicole M , Meiselbach Heike , Strauch Konstantin , Peters Annette , Paulweber Bernhard , Willeit Johann , Kiechl Stefan , Kronenberg Florian , Theurl Igor , Tancevski Ivan , Weiss Guenter
Published: February 2020

Aims

Imbalances of iron metabolism have been linked to the development of atherosclerosis. However, subjects with hereditary haemochromatosis have a lower prevalence of cardiovascular disease. The aim of our study was to understand the underlying mechanisms by combining data from genome-wide association study analyses in humans, CRISPR/Cas9 genome editing, and loss-of-function studies in mice.

Methods and results

Our analysis of the Global Lipids Genetics Consortium (GLGC) dataset revealed that single nucleotide polymorphisms (SNPs) in the haemochromatosis gene HFE associate with reduced low-density lipoprotein cholesterol (LDL-C) in human plasma. The LDL-C lowering effect could be phenocopied in dyslipidaemic ApoE−/− mice lacking Hfe, which translated into reduced atherosclerosis burden. Mechanistically, we identified HFE as a negative regulator of LDL receptor expression in hepatocytes. Moreover, we uncovered liver-resident Kupffer cells (KCs) as central players in cholesterol homeostasis as they were found to acquire and transfer LDL-derived cholesterol to hepatocytes in an Abca1-dependent fashion, which is controlled by iron availability.

Conclusion

Our results disentangle novel regulatory interactions between iron metabolism, KC biology and cholesterol homeostasis which are promising targets for treating dyslipidaemia but also provide a mechanistic explanation for reduced cardiovascular morbidity in subjects with haemochromatosis.
Comparison of Pseudomonas aeruginosa strains reveals that Exolysin A toxin plays an additive role in virulence
Authors: Medina-Rojas Maria , Stribling William , Snesrud Erik , Garry Brittany I , Li Yuanzhang , Gann Patrick Mc , Demons Samandra T , Tyner Stuart D , Zurawski Daniel V , Antonic Vlado
Published: February 2020

Background

Pseudomonas aeruginosa possesses an array of virulence genes ensuring successful infection development. A two-partner secretion system Exolysin BA (ExlBA) is expressed in the PA7-like genetic outliers consisting of ExlA, a pore-forming toxin and ExlB transporter protein. Presence of exlBA in multidrug-resistant (MDR) strains has not been investigated, particularly in the strains isolated from wounded soldiers.

Methods

We screened whole genome sequences of 2439 MDR- P. aeruginosa strains for the presence of exlBA. We compiled all exlBA positive strains and compared them with a diversity set for demographics, antimicrobial profiles and phenotypic characteristics: surface motility, biofilm formation, pyocyanin production and hemolysis. We compared the virulence of strains with comparable phenotypic characteristics in Galleria mellonella.

Results

We identified 33 exlBA-positive strains (1.5%). These strains have increased antibiotic resistance, they are more motile, produce more robust biofilms and have comparable pyocianin production with the diversity set despite the phenotypic differences within the group. In in vivo infection models, these strains were less virulent than Type III Secretion System (T3SS) positive counterparts.

Conclusions

exlBA-positive strains are wide spread among the PA7-like outliers. While not as virulent as strains possessing T3SS, these strains exhibit phenotypic features associated with virulence and are still lethal in vivo.
The Influence of Family and Friend Confidants on Marital Quality in Older Couples
Authors: Zhaoyang Ruixue , Martire Lynn M
Published: February 2020

Objectives

Relationships with confidants play an important role in older adults’ health and well-being. Particularly, family and friend confidants could significantly support or interfere with older adults’ marital relationships. This study used a dyadic approach to examine the influence of the structural features of both spouses’ family and friend confidant networks on older couples’ marital quality over 5 years.

Methods

Analyses used dyadic data from Wave 2 (2010–2011) and Wave 3 (2015–2016) interviews of the National Social Life, Health, and Aging Project (NSHAP), a nationally representative sample of community-dwelling older adults. Longitudinal actor–partner interdependence models were used to examine the influence of spouses’ family and friend confidant networks on couples’ marital quality.

Results

Having a larger friend confidant network or closer connections with friend confidants predicted greater marital quality for wives and husbands 5 years later. Larger family confidant networks of both spouses predicted greater marital quality for wives over time. However, husbands reported worse marital quality over time if wives reported having closer connections with their own family confidants at baseline.

Discussion

This study demonstrates the importance of family and friend confidant networks for older couples’ marital quality and highlights the benefits of having a larger or closer friend confidant network. Future research should examine mechanisms that account for the effects of spouses’ family and friend confidant networks on older couples’ marital quality.
Effectiveness and safety of minimally invasive Ivor Lewis and McKeown oesophagectomy in Chinese patients with stage IA–IIIB oesophageal squamous cell cancer: a multicentre, non-interventional and observational study
Authors: Zhang Tong , Hou Xiaobin , Li Yin , Fu Xiangning , Liu Lunxu , Xu Lin , Liu Yang
Published: February 2020

OBJECTIVES

To compare the long-term overall survival and outcomes of patients with oesophageal squamous cell cancer treated with minimally invasive McKeown or Ivor Lewis oesophagectomy.

METHODS

A multicentre, non-interventional, retrospective, observational study was performed in oesophageal squamous cell cancer patients pathologically confirmed with stage IA–IIIB middle or lower thoracic tumours who underwent minimally invasive oesophagectomy between 1 January 2010 and 30 June 2017 in 7 hospitals in China. Cox proportional hazards models assessed factors associated with overall survival and disease recurrence. The primary outcome was overall survival and cancer recurrence; the secondary outcomes included number of lymph nodes resected, 30-day mortality and postoperative complications.

RESULTS

A total of 1540 patients were included (950 McKeown, 590 Ivor Lewis). The mean age was 61.6 years, and 1204 were male. The mean number of lymph nodes removed during the McKeown procedure was 21.2 ± 11.4 compared with 14.8 ± 8.9 in Ivor Lewis patients (P < 0.001). The 5-year overall survival rates were 67.9% (McKeown) and 55.0% (Ivor Lewis). McKeown oesophagectomy was associated with improved overall survival (Ivor Lewis versus McKeown hazard ratio 1.36, 95% confidence interval 1.11–1.66; P = 0.003), particularly in patients with stage T3 tumours (middle thoracic oesophagus). However, postoperative complications occurred more frequently following McKeown oesophagectomy (42.2% vs 17.6% Ivor Lewis; P < 0.001).

CONCLUSIONS

Minimally invasive McKeown oesophagectomy was associated with improved overall survival and a decreased risk of disease recurrence, while Ivor Lewis patients had fewer postoperative complications. McKeown oesophagectomy may represent the optimal technique for patients with stage T3 tumours.

Clinical trial registration: clinicaltrial.gov

NCT03428074
Safety and efficacy of digital chest drainage units compared to conventional chest drainage units in cardiac surgery
Authors: Saha Shekhar , Hofmann Sandra , Jebran Ahmad Fawad , Waezi Narges , Kutschka Ingo , Friedrich Martin G , Niehaus Heidi
Published: February 2020

OBJECTIVES

The use of digital chest drainage units (CDUs) has become increasingly common in thoracic surgery due to several advantages. However, in cardiac surgery, its use is still limited in favour of conventional analogue CDUs. In order to investigate the potential benefit of digital CDUs in cardiac surgery, we compared the safety and efficacy of both systems in patients undergoing cardiac surgery at our centre.

METHODS

We retrospectively investigated 265 consecutive patients who underwent cardiac surgery at our institution between June 2017 and October 2017. These patients were divided into 2 groups: patients with analogue (A, n = 65) and digital CDUs (D, n = 200). Postoperative outcome was analysed and compared between both groups. In addition, the ‘user experience’ was evaluated by means of a questionnaire.

RESULTS

The median age of the cohort was 70 years (P = 0.167), 25.3% of patients were female (P = 0.414). There were no differences in terms of re-explorative surgery or use of blood products. Nor was there a difference in the overall amount of fluid collected. However, during the first 6 h, more fluid was collected by the digital CDUs. The overall rate of technical failure was 0.4%. We observed a significantly higher rate of clotting in the tubing system of the digital CDUs (P = 0.042). Concerning the user experience, the digital CDUs were associated with a more favourable ease of use on the regular wards (P < 0.001). With regard to the overall user experience, the digital CDUs outperformed the analogue systems (P = 0.002).

CONCLUSIONS

Digital CDUs can be safely and effectively applied in patients after cardiac surgery. Due to the improved patient mobility and simplified chest tube management, the use of digital CDUs may be advantageous for patients after cardiac surgery. However, the issue of clotting of the tubing systems should be addressed by further technical improvements.
Singularities of Divisors of Low Degree on Simple Abelian Varieties
Authors: Pareschi Giuseppe
Published: February 2020

It is known by the results of Kollár, Ein, Lazarsfeld, Hacon, and Debarre that effective divisors representing principal and other low-degree polarizations on complex abelian varieties have mild singularities. In this note, we extend these results to all polarizations of degree $<g$ on simple $g$-dimensional abelian varieties, settling a conjecture of Debarre and Hacon.
220 MHz Nuclear Magnetic Resonance Studies of Amygdalin and Some Related Compounds
Authors: Turczan John W , Medwick Thomas , Plank William M
Published: February 2020

A study of amygdalin, isoamygdalin, vicianin, amygdalinamide, amygdalinic acid, prunasin, sambunigrin, taxiphyllin, dhurrin, and holocalin has been carried out by nuclear magnetic resonance (NMR) spectrometry. Using 220 MHz spectra, the glycosides were studied in dimethylsulfoxide-d6 solution and in the presence of DO and D2O. Generally the assignments permit the following classification: The non-hydroxylic protons (including the anomeric protons) and the hydroxylic protons occur in the region from about 3.0 to 5.3 ppm; the aglycone methine hydrogen falls at about 6 ppm except for amygdalinamide and amygdalinic acid; the phenyl hydrogens are in the region of about 7 ppm. The chemical shifts and coupling constants for both OH6 and two H6 are independent of the aglycone stereochemistry, whereas the effect of the epimeric nature of the aglycone may be seen in terms of the carbohydrate portion resonances. The nature of the aglycone group may be classified as R or S, depending on the methine proton resonance. These studies should be very useful in the application of NMR to the recognition of aglycone stereochemistry and identification of amygdalin and other related cyanogenetic glycosides.
Standardized Assay for Clostridium botulinum Toxins
Authors: Schantz Edward J , Kautter Donald A
Published: February 2020

To improve the accuracy and precision of the mouse assay for botulinum toxins found in foods and body fluids, a stable reference standard of botulinum toxin has been developed. It contains 100 ng crystalline type A botulinum toxin/ml 0.05M pH 4.2 sodium acetate buffer which contains 3 mg bovine serum albumin and 2 mg gelatin/ml. The albumin and gelatin stabilize the toxin. For distribution to laboratories carrying out the assay, 0.5 ml of the standard is sealed in 1 ml glass vials. The standard reference toxin, used as directed, enables the assayer to establish the response of laboratory mice, under a specific set of conditions, to a definite amount of toxin and to express the toxin content of an unknown in terms of ng toxin/g or ml food or body fluid. The mouse assay by itself is not specific for botulinum toxin, but when used in conjunction with specific antisera for identification and typing, it is the most reliable test available.
Analysis of Synthetic Fibers by Diamond Cell and Sapphire Cell Infrared Spectrophotometry
Authors: Read Leonard K , Kopec Robert J
Published: February 2020

A rapid, simple, and nondestructive method of sample preparation and analysis is described for the infrared spectrophotometric analysis of synthetic fibers. This method uses a combined diamond cell and sapphire cell technique that yields highly resolved spectra with microgramsize fiber samples. From these highly resolved spectra, the generic type of fiber can be readily determined. Although the fiber sample has been physically crushed, it is not destroyed during the analysis and can be further examined by other analytical methods.
High Pressure Liquid Chromatographic Separation and Quantisation of Chlordiazepoxide. HC1 and Two of Its Related Compounds
Authors: Zagar John B , Van Lenten Frank J , Chrekian George P
Published: February 2020

A method is described for the separation and quantitative determination of chlordiazepoxide. HC1 and 2 related compounds, 7-chloro-l-3-dihydro-5-phenyl-2H-1, 4-benzodiazepin-2-one-4-oxide (CBO) and 2-amino-5-chIorobenzophenone (ACB), by high pressure liquid chromatography. The 3 compounds are separated on a reverse phase microparticulate column packing, using a mobile phase of acetonitrile and aqueous ammonium acetate. Bulk powders or capsule formulations are quantitated by direct comparison of their peak heights to those of appropriate reference standards. Data are presented showing the limit of detectability for the related compounds to be less than 80 ng CBO/ml and less than 40 ng ACB /ml. Based on peak heights, the relative standard deviation for the precision for chlordiazepoxide. HC1 is 0.42%. Recoveries from laboratory-prepared samples for chlordiazepoxide. HC1 were 99.4%; CBO, 102.4%; and ACB, 99.7%.
Spectrophotometric Determination of Vitamin A in Oils and Fats
Authors: Kamangar Teymour , Fawzf Ahmad B
Published: February 2020

A spectrophotometric method for determining vitamin A based on interaction with 50% trichloroacetic acid solution in dichloromethane was developed. The blue reaction product had a maximum absorption at 620 nm and obeyed Beer's law over the concentration range of 0.5-5.0 μg retinol/ml solution. The molar absorptivity of the reaction product was 1.58 × 105. As much as 100 μg vitamin D2, and β-carotene up to 12 times the vitamin A concentration, did not interfere with the determination. The results obtained from the determination of vitamin A in cod liver oil and butter showed excellent agreement with the Carr-Price method, 43.013 (d).
Instrumental Infrared Estimation of Fat, Protein, and Lactose in Milk: Collaborative Study
Authors: Biggs Delmar A
Published: February 2020

Thirty-six milks pre-analyzed by accepted standard methods were analyzed with Milkoscan instruments at 6 laboratories. Using pairs comparisons as described by Youden, precision errors for fat were about 0.033% for the first and 0.022% for the second of duplicate tests, indicating a carry-over effect for the first tests. Precision errors for protein were about 0.021 % for both tests. Systematic errors for fat were about 0.17% with calibrations based on reference analyses at each laboratory but were reduced to about 0.044% with calibrations by reference analyses from one laboratory. With homogenized milks, systematic errors for fat increased to about 0.07% and were larger at high fat levels. This effect could be minimized by changing the wavelength of maximum transmission for the fat filter. Systematic errors of about 0.067% for protein were reduced to about 0.03% with calibrations based on common reference analyses. Satisfactory calibrations for lactose were obtained with the 2 Milkoscan 203 models with standard errors of estimate of 0.034 and 0.033%. Results for homogenized and unhomogenized milk were diferent for most instruments, indicating the need to calibrate for them separately.
High Pressure Liquid Chromatographic Determination of Nitrofurazone in Milk
Authors: Vilim Arnost B , Macintosh Agnes I
Published: February 2020

A rapid high pressure liquid chromatographic (HPLC) screening method for the quantitative determination of nitrofurazone in milk has been developed. The drug is extracted with ethyl acetate from a 2.0 ml milk serum sample, the organic layer is evaporated to dryness, and the residue is dissolved in the mobile phase and injected into the liquid chromatograph. A reverse phase μBondapak C18 column is used with monitoring at 365 nm. The detection limit is 5 ppb and recoveries are 57—67%. Mass spectroscopic confirmation of the HPLC nitrofuran peak is described.
Colorimetric Determination of Poly(N-Vinyl-2-Pyrrolidone) in Contact Lens Solutions
Authors: Riedhammer Thomas M
Published: February 2020

A rapid colorimetric method is presented for the quantitative determination of poly(N-vinyl-2-pyrrolidone) in contact lens solutions. The method is simple, requires no sample pretreatment, and uses only a small volume of sample. The procedure is based on the measurement of the net absorbance of a poly(N-vinyl-2-pyrrolidone)-Congo red complex at 545 nm. An accuracy of greater than ± 4% was obtained for the concentration ranges usually found in contact lens solutions with a minimum detection level of 10 ppm. The method is useful as a screening procedure for solutions of unknown composition and as a quality assurance procedure for routine determinations.
Gas-Liquid Chromatographic Determination of Morphine, Heroin, and Cocaine
Authors: Prager Manfred J , Harrington Shirley M , Governo Thomas F
Published: February 2020

Morphine, heroin, and cocaine are quantitatively determined with the same gas-liquid chromatographic system. The compounds are separated on a 6 ft × 2 mm id glass column packed with a 1:1 mixture of 5% SE-30 on 80-100 mesh Chromosorb W and 3% OV-17 on 80-100 mesh Varaport 30. The column is temperatureprogrammed. Flame ionization detector responses are measured with a computer-based data system. Heroin and cocaine are chromatographed directly; morphine is derivatized first. The procedure was evaluated with previously analyzed commercial and forensic samples. Accuracy and precision were 5 and 3%, respectively.
Automated Fluorometric Determination of Vitamin C in Foods
Authors: Dunmire David L , Reese John D , Bryan Ralph , Seegers Mary
Published: February 2020

Two automated fluorometric methods were compared with the official AOAC methods for determining vitamin C in fortified ready-to-eat cereals, fruits, vegetables, baby foods, flour products, pet foods, meats, frozen dinners, juices, and nutritional health bars. Each sample was analyzed in duplicate on 2 days and included a recovery study on all products. Egberg's semiautomated method (Method 1) and Roy's automated method (Method 2) were compared with the manual AOAC tritrimetric and fluorometric methods. The correlation factor for Methods 1 and 2 were 0.999 and 0.979, respectively, when compared with the AOAC methods. The recovery study showed average recoveries of 97.8% for Method 1, 99.3% for Method 2, and 100.6% for the AOAC methods. The results suggest that Method 1 is the method of choice for the majority of the products analyzed.
Sensitive Thin Layer Chromatographic Detection of High Fructose Corn Sirup and Other Adulterants in Honey
Authors: Kushnir Irene
Published: February 2020

A highly sensitive procedure has been developed to detect the undeclared addition of high fructose corn sirup (HFCS) to honey. Carbohydrates must be separated first to achieve the requisite degree of sensitivity: charcoal-Celite chromatography was used to isolate a fraction containing oligo- and polysaccharides. The fraction was then concentrated and examined by thin layer chromatography on silica gel. Pure honeys yielded only 1 or 2 blue-grey or bluebrown spots at Rf values >0.35; a series of spots or blue streaks extending from the origin characterized adulterated samples. The method detects HFCS and conventional honey adulterants at levels as low as 10% or less of the total mixture. In addition, the procedure detects the presence in honey of all starch-derived sugar sirups tested thus far, regardless of the plant source.
Stability of Three Forms of Vitamin B6 to Laboratory Light Conditions
Authors: Ang Catharina Y W
Published: February 2020

Pyridoxine.HCl, pyridoxal.HCl, and pyridoxamine. 2HCl solutions were exposed to several laboratory light treatments, and the resulting vitamin retentions were determined by the AOAC microbiological method. The 5 treatments compared were total darkness, regular laboratory light, low actinic glass protection, yellow incandescent light, and golden fluorescent light. All treatments were imposed for 8 and 15 hr, and with the vitamin solutions at both a low and a high pH. Regular laboratory light was the most destructive to the vitamins, with greater destruction at higher pH and longer exposure time in all cases. Pyridoxine retentions ranged from 97 (pH 4.5, 8 hr) to 66% (pH 7, 15 hr); pyridoxal from 97 (pH 4.5, 8 hr) to 55% (pH 6, 15 hr); and pyridoxamine from 81 (pH 4.5, 8 hr) to 47% (pH 8, 15 hr). Retentions in low actinic glassware or in clear glassware under yellow or golden fluorescent light were essentially complete, ranging from 94 to 106% over all treatments and all 3 forms. Results showed that either of the 2 subdued light conditions, yellow or golden fluorescent light, is suitable in vitamin B6 assays and that low actinic glassware is suitable for storing sample solutions.
Semiautomated Method for the Analysis of Chlorpheniramine Maleate Tablets: Collaborative Study
Authors: Kirchhoefer Ross D ,   Collaborators:, Brown R L , Gleason J P , Hauser S , Kling R E , Moore E S , Savage T S
Published: February 2020

A semiautomated method for the analysis of chlorpheniramine maleate tablets, which is based on the USP XIX general assay for salts of organic nitrogenous bases, was collaboratively studied by 6 laboratories. Collaborators were supplied with 4 composites from 4 manufacturers. In the method, the active ingredient is dissolved in dilute HC1, sampled, made basic with dilute NaOH, and extracted with isooctane. The isooctane phase is resampled and the drug is re-extracted into dilute HCL. The absorbance of the acidic aqueous solution is measured at 265 nm. The Associate Referee assayed the collaborative samples to compare the semiautomated and USP XIX methods, and found close agreement in the results from the 2 methods. In the collaborative study of the semiautomated method, there was excellent agreement of the results obtained by the collaborators. The coefficients of variation ranged from 0.46 to 2.24%. The method has been adopted as official first action.
High Pressure Liquid Chromatographic Determination of Carbohydrates in Food Products: Evaluation of Method
Authors: Vries Jonathan W De , Heroff John C , Egberg David C
Published: February 2020

A high pressure liquid chromatographic (HFLC) method for determining 5 common carbohydrates in food products was evaluated. Reproducibility data were generated showing a relative standard deviation of 2.8%. Recovery studies on a variety of foods gave an average recovery of 98.8%. The HPLC data for 3 varieties of ready-to-eat cereals were compared with data from 4 independent laboratories using current AOAC chemical methods. The HPLC mean values differed from the chemical mean values by 3.2%.
Colorimetric Determination of Uric Acid in Poultry Excreta and in Mixed Feeds
Authors: Alumot Eugenia , Bielorai Rachel
Published: February 2020

Uric acid was determined in samples of poultry excreta and animal feeds to which poultry excreta were added. The rapid colorimetric method used by Van Handel was adapted for this purpose. The method is simple, accurate, and gives reproducible results.
Detection of Honey Adulteration By Carbohydrate Analysis
Authors: White Jonathan W
Published: February 2020

Thirteen market samples of falsified honey containing invert sirups or conventional corn sirup and 2 labeled mixtures have been analyzed. Results are interpreted in relation to literature values for various carbohydrate constituents of honey and their vulnerability. Published data on composition of United States honey have been refined for this purpose by eliminating samples containing a major portion of honeydew, thus narrowing the compositional ranges for known honey.
Gas-Liquid Chromatographic Method for Determining Bolstar Insecticide in Formulations: Collaborative Study
Authors: Boyd Willard G ,   Collaborators:, Antles H D , Audino J B , Bishop R , Campbell D L , Evans R T , Gale G T , Gentry G M , Grypa R , Guthery M D , Johnson H S , Launer J E , Meinen V J , Minyard J P , Noel R J , Roberts J R , Tannahill G O , Ullrich L , Linde D C Vande , Ware W C , Wayne R S , Winstead III G R
Published: February 2020

A gas-liquid chromatographic (GLC) method for determining Bolstar insecticide in liquid technical material and emulsifiable concentrate formulations was collaboratively studied using Youden’s matched pair scheme. Three matched sample pairs were analyzed by 21 laboratories using integrator area measurements and/or peak height measurements. Samples of a technical material containing about 78% active ingredient, a commercial 6 lb/ gal. emulsifiable concentrate containing about 64% active ingredient, and a synthetic emulsifiable concentrate containing about 64% active ingredient were dissolved in a measured amount of internal standard solution, tetracosane in toluene, and were subjected to gas-liquid chromatography on a column of 1.5% SE-30 + 1.5% OV-210. Bolstar was detected using flame ionization. The mean coefficient of variation by integrator area measurement for the 6 samples was 1.22%, and the mean coefficient of variation by peak height measurement for the 6 samples was 1.65%. The method was adopted as official first action.
Gas-Liquid Chromatographic Determination of N-Octylbicycloheptene Dicarboximide: Collaborative Study
Authors: Meinen Vernon J ,   Collaborators:, Allen J L , Audino J B , Boyd W G , Carlson D J , Carlstrom A A , Chang W L , Daubert J P , Dawson V , Gentry G M , Korger P , Launer J E , Lim B M , Looker J , Miller W K , Minyard J P , Partipilo T , Poulsen H H , Tannabull M , Winstead G R
Published: February 2020

A gas-liquid chromatographic method for the quantitative determination of N-octylbicycloheptene dicarboximide (MGK® 264 Synergist) was collaboratively studied with technical material and 2 formulations. The samples are diluted with acetone and determined after gas chromatography on an OV-1 column by a flame ionization detector. A statistical evaluation of the matched pair technical samples indicates good agreement among collaborators. An evaluation of the F-factor did not indicate significant systematic error contributions. A statistical evaluation of results for the 2 formulations showed coefficients of variation of 1.25 and 0.97. An examination of the t-values showed no contribution to systematic error. The method has been adopted as official first action.
Differential Pulse Polarographic Determination of Saccharin in Foods: Collaborative Study
Authors: Holak Walter , Krinitz Benjamin ,   Collaborators:, Carr R L , Gajan R J , Haberger L , Heusen C A , James T , Jasinski J , McNerney F Y , Tepedino N , Williamson J R
Published: February 2020

An improved differential pulse polarographic method for the determination of saccharin in foods has been developed. The sample (if solid) is blended with water; an aliquot is acidified with HC1, mixed with Celite, transferred to a chromatographic column, and eluted with chloroform. After chloroform is evaporated with a current of air, the residue is dissolved in 0.1N NaOH, and an aliquot is polarographed in a supporting electrolyte composed of 0.1N HC1, 0.1N KC1, and 0.1% tetrabutylammonium bromide. The method is sensitive, relatively precise, and applicable to a wide variety of foods. A collaborative study has been conducted and the results indicate average recoveries of 101.5, 99.8, 96.9, 91.9, and 95.3%, respectively, for samples containing saccharin from 0.028 to 1.4%. The method has been adopted as official first action.
Ripper Procedure for Determining Sulfur Dioxide in Wine: Collaborative Study
Authors: Vahl James M , Converse Jean E ,   Collaborators:, Andreasen A A , Barnett J H , Bence J G , Caputi A , Cherolis J A , Cofran D , Dowrie R , Dyer R H , Fike S A , Finley R G , Grorud R B , Hanson R , Jacobs D , Johnson A , Jones J C , Kipp W H , Kutschinski J L , Mattick L R , Peterson R , Pike R , Quinsland D , Rehn B W , Rice A C
Published: February 2020

Twenty-three laboratories analyzed 5 replicate wine samples according to a specified version of the Ripper direct iodometric titration for sulfur dioxide. Each sample was analyzed for (A) free S02, (B) total S02, and (C) iodine-reactive substances other than S02. Although variations of A with temperature and of A and B with time of analysis were anticipated, analysis of covariance showed no significant reduction in error when these variables were taken into account. Error did vary with S02 level and wine type, red vs white. Pooled estimates of precision (withinlaboratory error) in mg S02/L wine were, for white wine: (A) 3.3, (B) 10.4, (C) 1.9; for red wine: (A) 3.8, (B) 7.3, (C) 1.9. Pooled estimates of systematic (between-laboratory) error in mg SO2/L wine were, for white wine: (A) 2.7, (B) 16.6, (C) 2.1; for red wine: (A) 4.3, (B) 15.1, (C) 3.0. Although rapid and convenient, the Ripper method is severely limited by poor precision and large systematic error. The Ripper method is not recommended for adoption by the AOAC.
High Pressure Liquid Chromatographic Determination of Difenzoquat in Formulations
Authors: Barry Carla , Pike Richard K
Published: February 2020

Difenzoquat (l,2-dimethyl-3,5-diphenylpyrazolium ion) as its methyl sulfate is extracted from commercial pesticide formulations with acetonitrile-water (1+), with acetophenone added as internal standard. The sample is chromatographed by reverse phase high pressure liquid chromatography with ultraviolet detection at 280 nm. Peak area ratios are used for quantitative measurement. The method is simple, rapid, and direct, and its applicability to other quaternary ammonium herbicides is discussed.
New Spectrophotometric Assay for Pilocarpine
Authors: El-Masry Sawsan , Soliman Raafat
Published: February 2020

A quick method for the determination of pilocarpine in eye drops in the presence of decomposition products is described. The method involves complexation of the alkaloid with bromocresol purple at pH 6. After treatment with 0.1N NaOH, the liberated dye is measured at 580 nm. The method has a relative standard deviation of 1.99%, and has been successfully applied to the analysis of 2 batches of pilocarpine eye drops. The recommended method was also used to monitor the stability of a pilocarpine nitrate solution in 0.05N NaOH at 65°C. The BPC method failed to detect any significant decomposition after 2 h incubation, but the recommended method revealed 87.5% decomposition.
Simple, Sensitive, and Selective Thin Layer Chromatographic Technique for Detecting Some Photosynthesis Inhibiting Herbicides
Authors: Lawrence James F
Published: February 2020

Photosynthesis inhibiting herbicides such as triazines, phenylureas, phenylcarbamates, uracils, and acyl anilides are detected after thin layer chromatography (TLC) by spraying the plate with a mixture of spinach or bean leaf chloroplasts and the redox indicator 2,6-dichloroindophenol. The chloroplasts are isolated by homogenizing the fresh leaves with 0.5M sucrose solution. The filtrate is centrifuged, and the chloroplast plug is resuspended in glycerol–water (1+9) for preparation of the TLC spray. Minimum detectable levels of most ureas, triazines, and anilides are about 100–500 pg/spot. The selectivity of the reaction is such that the bipyridilium, phenoxyacid, and wild oat herbicides are negative. AH insecticides tested (carbamates, organophosphates, organochlorines) were negative. In samples such as potatoes, carrots, and corn, detection limits with no cleanup were 1 ppb or less for linuron or 5–10 ppb for atrazine.
High Performance Liquid Chromatographic Determination of Chloramphenicol in Milk
Authors: Wal Jean-Michel , Peleran Jean-Claude , Bories Georges F
Published: February 2020

A rapid and sensitive high performance liquid chromatographic method for the determination of trace amounts of chloramphenicol (CP) in milk has been developed. The antibiotic can be quantitated at a 10 ppb level with a limit of detectability estimated at 5 ppb. Recoveries ranged from 72 to 99.5%. Milking studies have been carried out on goats that received CP either by intramuscular injection or by intramammary administration. CP was measured in milk samples collected 1, 2, 3, 4, 5, 6, 7, 8, 24, 32 h after treatments. No residue could be detected 32 h after treatment. No interfering peaks appeared on control milk chromatograms.
High-Fructose Corn Syrup Adulteration of Honey: Confirmatory Testing Required with Certain Isotope Ratio Values
Authors: White Jonathan W
Published: February 2020

Misinterpretation of some analytical results obtained by using the carbon isotope ratio method for determining adulteration in honey has resulted in misclassification as adulterated some honeys falling in the grey area (–23.4 to –21.5 per mil). Samples having isotope ratios in that range must be confirmed by a positive TLC test.