Simultaneous determination of nitrite and nitrate by normal phase ion-pair liquid chromatography

Normal phase ion-pair high performance liquid chromatography has been used for simultaneous separation of nitrite and nitrate using tetraethylammonium (TEA)(+) as ion-pairing reagent. The concentration effect of (TEA)(+), buffer salt and pH of the eluent on separation is investigated. The UV detector response at various wavelengths has been optimized. The performance of the proposed method is compared with ion chromatography for quantification of the anions in potable water, wastewater and in food samples, such as spinach and lettuce.

The effects of delaying reward on choice preference in rats with hippocampal or selective septal lesions

Two experiments are reported in which rats were trained to choose one of two goal arms in a Y-maze, for water reward. In one arm, the rats always received water (the continuously reinforced-CRF-arm). In the other arm the rats only sometimes received water (the partially reinforced-PRF-arm). During the critical test phase in both experiments, we delayed the reward in the CRF arm only by 10 s. Experiment 1 tested intact rats given saline injections, or injections of chlordiazepoxide hydrochloride (Librium, 5 mg/kg), and rats with hippocampal or cortical control lesions. When reward was immediate in both arms all rats preferred the CRF arm. Once reward was delayed, the rats with hippocampal lesions switched their preference to the PRF arm, while the rats in the other treatment groups did not. Experiment 2 tested rats with medial septal lesions, lateral septal lesions or control operations in the same way. The rats with medial septal lesions, and to a lesser extent those with lateral septal lesions, switched their preference to the PRF arm when compared to the sham-operated controls. We conclude that damage to the hippocampus or its afferent pathway from the septum increases rats' sensitivity to temporal discontiguities between the outcome of a response and its emission.

Diabetes and onset of natural menopause: results from the European Prospective Investigation into Cancer and Nutrition

STUDY QUESTION

Do women who have diabetes before menopause have their menopause at an earlier age compared with women without diabetes?

SUMMARY ANSWER

Although there was no overall association between diabetes and age at menopause, our study suggests that early-onset diabetes may accelerate menopause.

WHAT IS KNOWN ALREADY

Today, more women of childbearing age are being diagnosed with diabetes, but little is known about the impact of diabetes on reproductive health.

STUDY DESIGN, SIZE, DURATION

We investigated the impact of diabetes on age at natural menopause (ANM) in 258 898 women from the European Prospective Investigation into Cancer and Nutrition (EPIC), enrolled between 1992 and 2000.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Determinant and outcome information was obtained through questionnaires. Time-dependent Cox regression analyses were used to estimate the associations of diabetes and age at diabetes diagnosis with ANM, stratified by center and adjusted for age, smoking, reproductive and diabetes risk factors and with age from birth to menopause or censoring as the underlying time scale.

MAIN RESULTS AND THE ROLE OF CHANCE

Overall, no association between diabetes and ANM was found (hazard ratio (HR) = 0.94; 95% confidence interval (CI) 0.89-1.01). However, women with diabetes before the age of 20 years had an earlier menopause (10-20 years: HR = 1.43; 95% CI 1.02-2.01, <10 years: HR = 1.59; 95% CI 1.03-2.43) compared with non-diabetic women, whereas women with diabetes at age 50 years and older had a later menopause (HR = 0.81; 95% CI 0.70-0.95). None of the other age groups were associated with ANM.

LIMITATIONS, REASONS FOR CAUTION

Strengths of the study include the large sample size and the broad set of potential confounders measured. However, results may have been underestimated due to survival bias. We cannot be sure about the sequence of the events in women with a late age at diabetes, as both events then occur in a short period. We could not distinguish between type 1 and type 2 diabetes.

WIDER IMPLICATIONS OF THE FINDINGS

Based on the literature, an accelerating effect of early-onset diabetes on ANM might be plausible. A delaying effect of late-onset diabetes on ANM has not been reported before, and is not in agreement with recent studies suggesting the opposite association.

STUDY FUNDING/COMPETING INTERESTS

The coordination of EPIC is financially supported by the European Commission (DG-SANCO) and the International Agency for Research on Cancer. The national cohorts are supported by Danish Cancer Society (Denmark); Ligue Contre le Cancer, Institut Gustave Roussy, Mutuelle Générale de l'Education Nationale, Institut National de la Santé et de la Recherche Médicale (INSERM) (France); German Cancer Aid, German Cancer Research Center (DKFZ) and Federal Ministry of Education and Research (BMMF) (Germany); Ministry of Health and Social Solidarity, Stavros Niarchos Foundation and Hellenic Health Foundation (Greece); Italian Association for Research on Cancer (AIRC) and National Research Council (Italy); Dutch Ministry of Public Health, Welfare and Sports (VWS), Netherlands Cancer Registry (NKR), LK Research Funds, Dutch Prevention Funds, Dutch ZON (Zorg Onderzoek Nederland), World Cancer Research Fund (WCRF), Statistics Netherlands (The Netherlands); ERC-2009-AdG 232997 and Nordforsk, Nordic Centre of Excellence programme on Food, Nutrition and Health (Norway); Health Research Fund (FIS), Regional Governments of Andalucía, Asturias, Basque Country, Murcia (no. 6236) and Navarra, ISCIII RETIC (RD06/0020) (Spain); Swedish Cancer Society, Swedish Scientific Council and Regional Government of Skåne and Västerbotten (Sweden); Cancer Research UK, Medical Research Council, Stroke Association, British Heart Foundation, Department of Health, Food Standards Agency, and Wellcome Trust (UK). None of the authors reported a conflict of interest.

Fluorocarbocyclic nucleosides: synthesis and antiviral activity of 2'- and 6'-fluorocarbocyclic 2'-deoxy guanosines

A series of four isomeric 2'- and 6'-fluorocarbocyclic guanosine analogues have been prepared and evaluated as potential anti-herpes agents. The racemic 2' beta-fluoro isomer 2-amino-1,9-dihydro- 9-[(1 alpha, 2 alpha, 3 beta, 4 alpha)-2-fluoro-3-hydroxy-4- (hydroxymethyl)cyclopentyl]-6H-purin-6-one (11a, C-AFG) and its 2' alpha-fluoro epimer 11b plus the chiral 6' beta-fluoro isomer 2-amino-1,9-dihydro-9-[[1S-(1 alpha, 2 alpha, 3 alpha, 4 beta)]- 2-fluoro-4-hydroxy-3-(hydroxymethyl)cyclopentyl]-6H-purine-6-one (11c) and its 6' alpha-fluoro epimer 11d were prepared from their respective fluoro amino diol hydrochlorides (6a,d). For comparison, the furanosyl compound 9-(2'-deoxy-2'-fluoro-beta-D-arabinofuranosyl)guanine (17, AFG) was prepared by coupling 2-amino-6-chloropurine with 2-deoxy-2-fluoro-3,5-di-O-benzoyl-alpha- D-arabinofuranosyl bromide followed by base hydrolysis. The 6' alpha-fluoro derivative 11d exhibited comparable activity to that of acyclovir (ACV) against herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) in vitro but was greater than 30-fold more active than ACV against HSV-1 and HSV-2 in vivo in the mouse systemic model. The 2' beta-fluoro derivative (11a, C-AFG) was extremely potent in vitro against HSV-1 and HSV-2 (ID50 0.006 and 0.05 micrograms/mL) and in vivo it was greater than 2 orders of magnitude more potent than ACV against HSV-1 and 70-fold more potent against HSV-2. The 2' alpha-fluoro 11b and 6' beta-fluoro 11c isomers were much less active.

Safety and efficacy of non-steroidal anti-inflammatory drugs to reduce ileus after colorectal surgery

BACKGROUND

Ileus is common after elective colorectal surgery, and is associated with increased adverse events and prolonged hospital stay. The aim was to assess the role of non-steroidal anti-inflammatory drugs (NSAIDs) for reducing ileus after surgery.

METHODS

A prospective multicentre cohort study was delivered by an international, student- and trainee-led collaborative group. Adult patients undergoing elective colorectal resection between January and April 2018 were included. The primary outcome was time to gastrointestinal recovery, measured using a composite measure of bowel function and tolerance to oral intake. The impact of NSAIDs was explored using Cox regression analyses, including the results of a centre-specific survey of compliance to enhanced recovery principles. Secondary safety outcomes included anastomotic leak rate and acute kidney injury.

RESULTS

A total of 4164 patients were included, with a median age of 68 (i.q.r. 57-75) years (54·9 per cent men). Some 1153 (27·7 per cent) received NSAIDs on postoperative days 1-3, of whom 1061 (92·0 per cent) received non-selective cyclo-oxygenase inhibitors. After adjustment for baseline differences, the mean time to gastrointestinal recovery did not differ significantly between patients who received NSAIDs and those who did not (4·6 versus 4·8 days; hazard ratio 1·04, 95 per cent c.i. 0·96 to 1·12; P = 0·360). There were no significant differences in anastomotic leak rate (5·4 versus 4·6 per cent; P = 0·349) or acute kidney injury (14·3 versus 13·8 per cent; P = 0·666) between the groups. Significantly fewer patients receiving NSAIDs required strong opioid analgesia (35·3 versus 56·7 per cent; P < 0·001).

CONCLUSION

NSAIDs did not reduce the time for gastrointestinal recovery after colorectal surgery, but they were safe and associated with reduced postoperative opioid requirement.

Comparative quantitative assessment of global small bowel motility using magnetic resonance imaging in chronic intestinal pseudo-obstruction and healthy controls

BACKGROUND

Chronic intestinal pseudo-obstruction (CIPO) is characterized by dilatation of the bowel lumen and abnormal motility. In this study, we aimed to quantify small bowel dysmotility in CIPO using a validated pan-intestinal motility assessment technique based on motion capture magnetic resonance imaging (MRI) compared to normal controls. In addition, we explored if motility responses of CIPO patients to neostigmine challenge differed from healthy volunteers.

METHODS

Twenty healthy volunteers (mean age 28, range 22-48) and 11 CIPO patients (mean age 47, range 19-90) underwent MRI enterography to capture global small bowel motility. Eleven controls and seven CIPO patients further underwent a randomized placebo-controlled crossover study of either intravenous neostigmine (0.5 mg) or saline with motility MRI repeated at a mean of 3 weeks. Motility was quantified in regions of interest placed to encompass the whole small bowel volume using a validated, postprocessing technique to give a global motility index in arbitrary units (AU). Baseline and stimulated motility was compared using Wilcoxon rank-sum paired T-tests.

KEY RESULTS

Baseline global small bowel motility was significantly lower in CIPO patients compared to controls (mean 0.25 AU vs 0.35 AU, p < 0.001). Motility in both groups increased significantly after neostigmine (0.06 AU increase, p = 0.016 in CIPO and 0.06 AU increase, p = 0.002 in controls). Three patients with scleroderma had a reduced response to neostigmine.

CONCLUSIONS & INFERENCES

Global small bowel motility in CIPO patients is significantly lower than controls and response to the pro-kinetic agent neostigmine may differ according to disease phenotype. Software-quantified bowel motility using cine MRI has potential as a future tool to investigate enteric dysmotility.

Benign primary tumours of the ribs

Benign primary tumours of the ribs are rare and may be identified during the investigation of a clinically suspected abnormality or as an incidental finding. This review describes the spectrum of benign tumours that can involve the rib and illustrates the radiographic, computed tomography (CT) and magnetic resonance (MR) imaging appearances that may facilitate diagnosis.

Combined effect of low-penetrant SNPs on breast cancer risk

BACKGROUND

Although many low-penetrant genetic risk factors for breast cancer have been discovered, knowledge about the effect of multiple risk alleles is limited, especially in women <50 years. We therefore investigated the association between multiple risk alleles and breast cancer risk as well as individual effects according to age-approximated pre- and post-menopausal status.

METHODS

Ten previously described breast cancer-associated single-nucleotide polymorphisms (SNPs) were analysed in a joint European biobank-based study comprising 3584 breast cancer cases and 5063 cancer-free controls. Genotyping was performed using MALDI-TOF mass spectrometry, and odds ratios were estimated using logistic regression.

RESULTS

Significant associations with breast cancer were confirmed for 7 of the 10 SNPs. Analysis of the joint effect of the original 10 as well as the statistically significant 7 SNPs (rs2981582, rs3803662, rs889312, rs13387042, rs13281615, rs3817198 and rs981782) found a highly significant trend for increasing breast cancer risk with increasing number of risk alleles (P-trend 5.6 × 10(-20) and 1.5 × 10(-25), respectively). Odds ratio for breast cancer of 1.84 (95% confidence interval (CI): 1.59-2.14; 10 SNPs) and 2.12 (95% CI: 1.80-2.50; 7 SNPs) was seen for the maximum vs the minimum number of risk alleles. Additionally, one of the examined SNPs (rs981782 in HCN1) had a protective effect that was significantly stronger in premenopausal women (P-value: 7.9 × 10(-4)).

CONCLUSION

The strongly increasing risk seen when combining many low-penetrant risk alleles supports the polygenic inheritance model of breast cancer.

Magnetic resonance imaging of perfusion in rat cerebral 9L tumor after nicotinamide administration

PURPOSE

To investigate the effect of nicotinamide on normal brain and 9L tumor blood flow in the rat using magnetic resonance imaging (MRI) and arterial spin tagging.

METHODS AND MATERIALS

Using MRI at 7 Tesla, measurements of blood perfusion were determined from two-dimensional maps of intracerebral 9L rat tumors and normal Fischer rat brains. The spatial and temporal influence of nicotinamide, 500 mg/kg i.p., on cerebral blood flow (CBF) was studied in normal brain and tumors between 5 and 21 days after tumor implantation. The MRI CBF measurements employed a variable tip-angle-gradient-recalled echo (VTA-GRE-CBF) readout of the magnetization of the tissue slice. The VTA-GRE-CBF required 8 minutes for a blood flow image with inplane resolution of 250 microm x 500 microm x 2 mm.

RESULTS

Normal brain blood flow decreased following the administration of nicotinamide. In contrast, tumor blood flow remained unaffected in the time following nicotinamide administration. Consequently, the blood flowing in the tumor relative to that in normal brain demonstrated a significant and selective increase in response to nicotinamide administration. Relative tumor blood flow increased at 10 minutes after nicotinamide injection compared with predrug levels and remained elevated for at least 1 hour.

CONCLUSION

The results suggest that nicotinamide will not enhance radiosensitivity of brain tumors. The results support the use of nicotinamide to improve delivery of anticancer therapeutics through its ability to selectively increase tumor blood flow relative to that in normal brain.

Imaging features of central nervous system haemangiopericytomas

Intracranial and spinal haemangiopericytomas are uncommon, durally based tumours. They macroscopically resemble meningiomas but are distinct histologically, have a more aggressive natural history and require different management. We present a pictorial review illustrating the radiological manifestations of these tumours that will aid in their preoperative identification.

The imaging of lumbar spondylolisthesis

Lumbar spondylolisthesis is a common finding on plain radiographs. The condition has a variety of causes which can be differentiated on the basis of imaging findings. As the treatment is dependent upon the type of spondylolisthesis, it is important for the radiologist to be aware of these features. We present a pictorial review of the imaging features of lumbar spondylolisthesis and explain the differentiating points between different groups of this disorder. The relative merits of the different imaging techniques in assessing lumbar spondylolisthesis are discussed.

Tumour-related factors and prognosis in breast cancer detected by screening

BACKGROUND

Breast cancer detected by screening has an unexplained prognostic advantage beyond stage shift compared with cancers detected clinically. The aim was to investigate biological factors in invasive breast cancer, with reference to mode of detection and rate of death from breast cancer.

METHODS

Histology, oestrogen receptor α and β, progesterone receptor, human epidermal growth factor receptor (HER) 2, cyclin D1, p27, Ki-67 and perinodal growth were analysed in 466 tumours from a prospective cohort, the Malmö Diet and Cancer Study. Using logistic regression, odds ratios were calculated to investigate the relationship between tumour characteristics and mode of detection. The same tumour factors were analysed in relation to standard prognostic features. Death from breast cancer was analysed using Cox regression with adjustments for standard tumour factors; differences following adjustment were analysed by means of Freedman statistics.

RESULTS

None of the biological tumour characteristics varied with mode of detection of breast cancer. After adjustment for age, tumour size, axillary lymph node involvement (ALNI) and grade, women with cancer detected clinically had an increased risk of death from breast cancer (hazard ratio 2·48, 95 per cent confidence interval 1·34 to 4·59), corresponding to a 37·2 per cent difference compared with the unadjusted model. Additional adjustment for biological tumour factors studied caused only minor changes.

CONCLUSION

None of the biological tumour markers investigated explained the improved prognosis in breast cancer detected by screening. None of the factors was related to ALNI, suggesting that other mechanisms may be responsible for tumour spread.

Stress-induced Salter-Harris I growth plate injury of the proximal tibia: first report

We describe a case of chronic Salter-Harris I injury of the proximal tibial epiphysis. To our knowledge such an injury has not been described in the English language literature. The radiological appearance can mimic chronic infection. The possibility of chronic athletic stress-related change should be considered in such scenarios to avoid a misdiagnosis.

Atraumatic quantitation of cerebral perfusion in cats by 19F magnetic resonance imaging

We have noninvasively produced low-resolution, quantitative nuclear magnetic resonance images of cerebral blood flow in 2-ml voxels in eight cats. Typical signal-to-noise of 4 to 1 was obtained in cerebral voxels in 16.5-s epochs. Mean flow during normocapnia (paCO2 = 39 +/- 4 mm Hg) and hypercapnia (paCO2 = 62 +/- 4 mm Hg) was 53 +/- 20 ml/100 g-min and 140 +/- 36 ml/100 g-min, respectively. Fast flows in normocapnia were 94 +/- 13 and 182 +/- 39 ml/100 g-min in hypercapnia. These results suggest that an atraumatic quantitative imaging assessment of cerebral perfusion may be possible in humans using these techniques.

Safety of hospital discharge before return of bowel function after elective colorectal surgery

BACKGROUND

Ileus is common after colorectal surgery and is associated with an increased risk of postoperative complications. Identifying features of normal bowel recovery and the appropriateness for hospital discharge is challenging. This study explored the safety of hospital discharge before the return of bowel function.

METHODS

A prospective, multicentre cohort study was undertaken across an international collaborative network. Adult patients undergoing elective colorectal resection between January and April 2018 were included. The main outcome of interest was readmission to hospital within 30 days of surgery. The impact of discharge timing according to the return of bowel function was explored using multivariable regression analysis. Other outcomes were postoperative complications within 30 days of surgery, measured using the Clavien-Dindo classification system.

RESULTS

A total of 3288 patients were included in the analysis, of whom 301 (9·2 per cent) were discharged before the return of bowel function. The median duration of hospital stay for patients discharged before and after return of bowel function was 5 (i.q.r. 4-7) and 7 (6-8) days respectively (P < 0·001). There were no significant differences in rates of readmission between these groups (6·6 versus 8·0 per cent; P = 0·499), and this remained the case after multivariable adjustment for baseline differences (odds ratio 0·90, 95 per cent c.i. 0·55 to 1·46; P = 0·659). Rates of postoperative complications were also similar in those discharged before versus after return of bowel function (minor: 34·7 versus 39·5 per cent; major 3·3 versus 3·4 per cent; P = 0·110).

CONCLUSION

Discharge before return of bowel function after elective colorectal surgery appears to be safe in appropriately selected patients.

Sodium salicylate reduces the level of GABAB receptors in the rat's inferior colliculus

Previous studies have indicated that sodium salicylate (SS) can cause hearing abnormalities through affecting the central auditory system. In order to understand central effects of the drug, we examined how a single intraperitoneal injection of the drug changed the level of subunits of the type-B γ-aminobutyric acid receptor (GABAB receptor) in the rat's inferior colliculus (IC). Immunohistochemical and western blotting experiments were conducted three hours following a drug injection, as previous studies indicated that a tinnitus-like behavior could be reliably induced in rats within this time period. Results revealed that both subunits of the receptor, GABABR1 and GABABR2, reduced their level over the entire area of the IC. Such a reduction was observed in both cell body and neuropil regions. In contrast, no changes were observed in other brain structures such as the cerebellum. Thus, a coincidence existed between a structure-specific reduction in the level of GABAB receptor subunits in the IC and the presence of a tinnitus-like behavior. This coincidence likely suggests that a reduction in the level of GABAB receptor subunits was involved in the generation of a tinnitus-like behavior and/or used by the nervous system to restore normal hearing following application of SS.

Distribution analysis of profilin isoforms at transcript resolution with mRNA-seq and secondary structure in various organs of Rattus norvegicus

Profilin (Pfn) is an actin binding protein, ubiquitously found in mammals and is essential for the actin polymerization in cells. In brain, it plays a pivotal role in neurogenesis and synapse formation by interacting with various proteins. Four Pfn isoforms have been identified in mammals. This study presents the identification and transcriptional expression of various Pfn isoforms (Pfn1, Pfn2, Pfn3 and Pfn4) in brain, heart, kidney, liver, and muscle and testis of Rattus norvegicus. Organs have been classified into groups based on some similarities. Group I includes brain and testis, Group II includes skeletal muscle and heart, while Group III includes kidney and liver. Pfn1 has been identified in all groups, Pfn2 and Pfn3 have been identified in group I, group III and in one organ (skeletal muscle) of group II. To the best of the authors knowledge, no report of Pfn1 and Pfn2 presence in testis, Pfn3 in brain, liver and skeletal muscle, Pfn4 in kidney and skeletal muscle exists to date. Transcriptional expression showed variations among expression level of different Pfn isoforms in various organs with respect to the control gene GADPH. We hypothesize that this could be attributed to profilin isoform specific mRNA structure and corresponding motifs, which generally contribute to similar or varied decay rates, cellular localization, post transcriptional regulation pattern and ligand binding.

Is pre-assessment for anti-TNF therapy in RA necessary in the UK? Analysis of DAS28 in six centres

OBJECTIVES

National Institute for Health and Clinical Excellence (NICE) guidelines for anti-tumour necrosis factor (TNF) in rheumatoid arthritis (RA) state that two pre-assessments of Disease Activity Score (DAS28) should be performed a month apart. We performed a retrospective audit of data from six centres to determine the stability of DAS28 between assessments, and the proportion of patients still satisfying eligibility criteria at baseline.

METHODS

All RA patients assessed for anti-TNF from six centres had their pre-assessment DAS28 (DAS-1) compared with their baseline DAS28 (DAS0) using paired t-tests, and a similar analysis for the components of the DAS28. Patients who were no longer eligible for anti-TNF at DAS0 were noted.

RESULTS

Six hundred and seventy-nine RA patients showed no significant change in the DAS28, with a mean DAS-1 of 6.74 and DAS0 of 6.73. (P = 0.86). Of the patients, 97.2% fulfilled the UK eligibility criteria at DAS0. Comparison of the individual components of the DAS28 between the two pre-assessment dates showed that there was no significant difference between either the numbers of swollen joints or the erythrocyte sedimentation rate (ESR), but there was a significant increase in the numbers of tender joints of 1.41 (P < 0.001) and in the visual analogue scale (VAS) of 4.22 (P < 0.001).

DISCUSSION

The overwhelming majority of patients who fulfil eligibility criteria for anti-TNF drugs 1 month prior to baseline also fulfil the criteria at baseline. There is no significant change in the DAS28 over the month waiting to go onto anti-TNF therapy. A single assessment of the DAS28 would suffice to enable patients to go on to anti-TNF treatment.

Effect of cardiac resynchronization therapy on septal perfusion and septal thickening: Association with left ventricular function, reverse remodelling and dyssynchrony

BACKGROUND

We evaluated the effect of cardiac resynchronization therapy (CRT) on septal perfusion and thickening at 6 months post implantation assessed on Tc99m-MIBI Gated myocardial perfusion SPECT (GMPS).We also studied the association of change in septal perfusion and thickening with primary outcome defined as at least one [improvement in ≥1NYHA class, left ventricular ejection fraction (LVEF) by ≥ 5%, reduction of end-systolic volume (ESV) by ≥ 15%, and improvement ≥ 5 points in Minnesota living with heart failure questionnaire (MLHFQ)].

METHOD

One hundred and five patients underwent clinical and GMPS evaluation before and at 6 months post CRT.

RESULT

Post CRT there was significant improvement in mean normalized septal perfusion uptake and in septal thickening (P value = 0.001, both). There was no significant relation between improvement in septal perfusion and primary outcome. However, improvement in septal thickening was statistically significant with favorable primary outcome (P = 0.001).There was no significant correlation between improvement of septal perfusion and improvement in LVEF, reduction in End diastolic volume (EDV), ESV, and Left ventricular Dyssynchrony (LVD). But, there was significant correlation between improvement of septal thickening and these parameters.

CONCLUSION

Improvement in septal thickening was associated with reverse remodeling, improvement in LVEF, and reduction of LVD.