Identifying canonical and replicable multi-scale intrinsic connectivity networks in 100k+ resting-state fMRI datasets

Despite the known benefits of data-driven approaches, the lack of approaches for identifying functional neuroimaging patterns that capture both individual variations and inter-subject correspondence limits the clinical utility of rsfMRI and its application to single-subject analyses. Here, using rsfMRI data from over 100k individuals across private and public datasets, we identify replicable multi-spatial-scale canonical intrinsic connectivity network (ICN) templates via the use of multi-model-order independent component analysis (ICA). We also study the feasibility of estimating subject-specific ICNs via spatially constrained ICA. The results show that the subject-level ICN estimations vary as a function of the ICN itself, the data length, and the spatial resolution. In general, large-scale ICNs require less data to achieve specific levels of (within- and between-subject) spatial similarity with their templates. Importantly, increasing data length can reduce an ICN's subject-level specificity, suggesting longer scans may not always be desirable. We also find a positive linear relationship between data length and spatial smoothness (possibly due to averaging over intrinsic dynamics), suggesting studies examining optimized data length should consider spatial smoothness. Finally, consistency in spatial similarity between ICNs estimated using the full data and subsets across different data lengths suggests lower within-subject spatial similarity in shorter data is not wholly defined by lower reliability in ICN estimates, but may be an indication of meaningful brain dynamics which average out as data length increases.

P-633 Poor ovarian response: what are the implications for developmental and genetic health of embryos?

Study question

Are patients with a low ovarian response more likely to develop embryos with chromosomal alterations?

Summary answer

Low ovarian response has an impact on embryonic development and the genetic normality rate of embryos.

What is known already

Low ovarian response is characterized by a reduction in the follicular response resulting in a reduced number of eggs. This fact has an impact on the outcome of assisted reproduction treatments. Therefore, understanding the genetic behavior of the embryos of these patients is still a great challenge for both the clinic and the in vitro fertilization laboratory, because, with a better understanding of the embryo's genetic segregation process, it will be possible to apply more assertive behaviors in the human reproduction routine.

Study design, size, duration

This retrospective cross-sectional study included 73 patients up to 35 years old, splitted into two groups. The poor ovarian responder group (n = 32) and the controls (n = 41). The study group included patients with poor ovarian response, less than six MII oocytes after ovarian punction. The control group was selected according to the following inclusion criteria: the presence of tubal factor unexplained infertility, or adenomyosis. The data were collected between January 2019 and December 2021.

Participants/materials, setting, methods

All patients included in the study (n = 73) underwent the same assisted reproduction treatment with embryos transferred after biopsy and PGT-A. The T-Students test was applied to compare numerical variables and the q-square test for categorical variables. All the analysis was performed in SPSS software (V26). Patients who had other factors associated with poor ovarian response were excluded.

Main results and the role of chance

In the comparison between the groups, the differences in the levels of AMH, progesterone, and the number of oocytes in MII were observed, as expected for the two groups (p < 0.05). However, the control group had a higher rate of chromosomally normal embryos when compared to patients with a low ovarian response (60.9%± 30.1 vs 37.6%± 39.7, p = 0.0057) respectively. The other variables such as age, FSH, LH, BMI, estradiol, fertilization rate, rate of blastocyst formation, and quality of blastocysts did not show statistically significant differences.

Limitations, reasons for caution

Preliminary results with a low number of patients.

Wider implications of the findings

Patients with a low ovarian response may have lower rates of embryonic chromosomal normality, this fact is important for the indication of genetic testing for these couples. Future prospective studies should be carried out with a larger number of patients to understand the mechanisms that cause genetic alterations in embryos.

Trial registration number

non applicable

The impact of mentoring in trauma and orthopaedic training: a systematic review

INTRODUCTION

Trauma and orthopaedics is renowned for being a challenging yet rewarding career. The value of mentorship in medical and surgical training is known to be beneficial; however, the prevalence and quality of mentorship opportunities in orthopaedics are less well studied. Identifying the strengths and weaknesses of mentoring programmes in orthopaedic training and recognising barriers to effective mentorship are key to unlocking the full potential of future orthopaedic surgeons.

METHODS

A comprehensive search of PubMed, Medline, EMBASE and the Cochrane Library was performed. All studies published in the English language that reported data on mentorship programmes in orthopaedic training were included.

FINDINGS

A total of 23 studies met the inclusion criteria. These studies demonstrated that formal mentorship programmes in orthopaedics are lacking but are sought after, with a positive influence on satisfaction and future career choice/subspecialty selection identified. Several barriers to mentoring in the field were recognised including the difficulty faced by female trainees, the availability of mentors and time constraints. The opportunity to choose a mentor, a mentor with the same interests, regular meetings and the option of gender congruent mentorship were all identified as crucial requirements for effective mentorship.

CONCLUSION

Mentorship opportunities must be more accessible to all orthopaedic trainees alike and should aim to incorporate the attributes identified to provide the highest calibre of training to prospective orthopaedic surgeons.

Boat noise impacts early life stages in the Lusitanian toadfish: A field experiment

Marine traffic is the most common and chronic source of ocean noise pollution. Despite the evidence of detrimental effects of noise exposure on fish, knowledge about the effects on the critical early life stages - embryos and larvae - is still scarce. Here, we take a natural habitat-based approach to examine potential impacts of boat noise exposure in early life stages in a wild fish population of the Lusitanian toadfish (Halobatrachus didactylus). In-situ experiments were carried out in the Tagus estuary, an estuary with significant commercial and recreational boat traffic. Nests with eggs were exposed to either ambient (control) or boat noise (treatment), for 1 fortnight. Eggs were photographed before being assigned to each treatment, and after exposure, to count number of eggs and/or larvae to assess survival, and sampled to study development and oxidative stress and energy metabolism-related biomarkers. Data concerns 4 sampling periods (fortnights) from 2 years. Results indicate that offspring survival did not differ between treatments, but boat noise induced a detrimental effect on embryos and larvae stress response, and on larvae development. Embryos showed reduced levels of electron transport system (ETS), an energy metabolism-related biomarker, while larvae showed higher overall stress responses, with increased levels of superoxide dismutase (SOD) and DNA damage (oxidative stress related responses), ETS, and reduced growth. With this study, we provided the first evidence of detrimental effects of boat noise exposure on fish development in the field and on stress biomarker responses. If these critical early stages are not able to compensate and/or acclimate to the noise stress later in the ontogeny, then anthropogenic noise has the potential to severely affect this and likely other marine fishes, with further consequences for populations resilience and dynamics.

Validation of an analytical method based on QuEChERS and LC-MS/MS to quantify nine mycotoxins in plant-based milk

Plant-based beverages (popularly known as vegetable milk) have become increasingly important in recent years. However, the nonexistence of information on mycotoxin contamination is noticeable. We herein describe the development and validation of an analytical methodology that employs QuEChERS and LC-MS/MS for the simultaneous determination of nine mycotoxins (aflatoxins B1, B2, G1, and G2, fumonisins B1 and B2, ochratoxin A, zearalenone, and citreoviridin) in seven types of vegetable milk (peanut, oat, rice, cashew, maize, soybean, and coconut). The method provided the following quantification limits, recoveries at the lowest validated concentration and relative standard deviations under repeatability conditions at the lowest validated concentration, respectively: aflatoxin B1 (0.023 μg/l, 84.98 and 9.23%); aflatoxin B2 (0.024 μg/, 93.00 and 4.85%); aflatoxin G1 (0.057 μg/l, 98.85 and 5.53%); aflatoxin G2 (0.031 μg/l, 96.64 and 4.08%); fumonisin B1 (2.166 μg/l, 75.55 and 16.78%); fumonisin B2 (1.105 μg/l, 70.47 and 11.89%); ochratoxin A (0.104 μg/l, 72.05 and 5.12%); zearalenone (8.093 μg/l, 107.10 and 6.37%); citreoviridin (1.305 μg/l, 97.25 and 7.28%). The method uses small amounts of samples, solvents, and other inexpensive reagents with no need for laborious clean-up and pre-concentration steps. Its attractive characteristics (simplicity, low cost compared to procedures that use immunoaffinity columns, and full compatibility with routine analyses) make it potentially valuable. As a proof-of-principle, the validated methodology was applied to seven commercial samples of different compositions showing that some were contaminated with aflatoxins and ochratoxin A.

Effects of endurance and strength exercises associated with whey protein supplementation on quality of life (SF36) in community-dwelling seniors

Introduction Ageing is a natural, physiological and markedly heterogeneous process; however, it is possible to modify the functional decline and to promote healthy ageing. The practise of physical exercise and nutrition have shown benefits in the promotion of a better quality of life (QoL).

Objectives To verify whether protein supplementation associated with physical exercise contributes to the QoL of seniors living in the community.

Methodology A clinical prospective, blind, randomized, placebo-controlled study with a control group was conducted. The sample was probabilistic and randomly assigned. They were distributed through the 4 arms of the study with 19 participants each:1-physical exercise (strength and endurance) + whey protein supplement (20g); 2-physical exercise (strength and endurance) + placebo; 3-only whey protein supplement (20g); 4-control (without intervention). Each group was assessed at baseline and past 12 weeks. QoL was evaluated through SF36, before and after the intervention. Descriptive and inferential statistics were used.

Results The sample consisted of 79 individuals, 55 women and 25 men, with a mean age of 68.54±5.72, mean height 1.57±0.09m, mean weight 72.7±14.3kg, being homogeneous with respect to age by sex and the anthropometric characteristics (body mass index, arm and leg circumferences). The comparison between the pre and post-intervention results showed that groups 1 and 2 significantly improved their QoL (p < 0.05); patients in groups 1 and 3 improved substantially more than in groups 2 and 4 (p < 0.05). Subjects in group 4 worsened their outcomes in all domains of QoL assessed.

Conclusion Protein supplementation showed a positive influence on the quality of life, primarily when associated with physical exercise. In fact, seniors who were not submitted to supplementation or a prescribed exercise showed a worsening of their quality of life throughout the study.

Dietary practices in propionic acidemia: A European survey

Background

The definitive dietary management of propionic acidaemia (PA) is unknown although natural protein restriction with adequate energy provision is of key importance.

Aim

To describe European dietary practices in the management of patients with PA prior to the publication of the European PA guidelines.

Methods

This was a cross-sectional survey consisting of 27 questions about the dietary practices in PA patients circulated to European IMD dietitians and health professionals in 2014.

Results

Information on protein restricted diets of 186 PA patients from 47 centres, representing 14 European countries was collected. Total protein intake [PA precursor-free L-amino acid supplements (PFAA) and natural protein] met WHO/FAO/UNU (2007) safe protein requirements for age in 36 centres (77%). PFAA were used to supplement natural protein intake in 81% (n = 38) of centres, providing a median of 44% (14–83%) of total protein requirement. Seventy-four per cent of patients were prescribed natural protein intakes below WHO/FAO/UNU (2007) safe levels in one or more of the following age groups: 0–6 m, 7–12 m, 1–10 y, 11–16 y and > 16 y. Sixty-three per cent (n = 117) of patients were tube fed (74% gastrostomy), but only 22% received nocturnal feeds.

Conclusions

There was high use of PFAA with intakes of natural protein commonly below WHO/FAO/UNU (2007) safe levels. Optimal dietary management can only be determined by longitudinal, multi-centre, prospective case controlled studies. The metabolic instability of PA and small patient cohorts in each centre ensure that this is a challenging undertaking.

Pharmacokinetics of table and Port red wine anthocyanins: a crossover trial in healthy men

This study was designed to evaluate the pharmacokinetics of Port and table red wine anthocyanins in healthy men. Volunteers were recruited to drink 250 mL of a table red wine (221 mg of anthocyanins) and 150 mL of young Port red wine (49 mg of anthocyanins). Venous blood was collected from participants at 0, 15, 30, 60 and 120 min after wine ingestion. Urine samples were collected at baseline and at 120 min. Anthocyanins and anthocyanin metabolites in plasma and urine samples were quantified by HPLC-DAD and tentatively identified by LC-MS. Red wine anthocyanins were detected in their intact forms in both plasma and urine samples, but the glucuronylated metabolites of peonidin and malvidin (PnGlucr and MvGlucr) were the two main derivatives detected after both red wine consumptions. For the first time, and supported by the synthesis of Mv3Glucr, the main pathway followed by Mv3glc after absorption was described and involves anthocyanidin conjugation with glucuronic acid after glucose removal. Despite the lower total content of anthocyanins ingested when volunteers drank Port wine, no differences were observed in the plasma C_max of MvGlucr and PnGlucr after table and Port red wine consumption. The relative bioavailability of anthocyanins in Port wine was 96.58 ± 5.74%, compared to the anthocyanins present in red wine. In conclusion, both Port and table red wines are good sources of bioavailable anthocyanins.

Dietary practices in isovaleric acidemia: A European survey

Background

In Europe, dietary management of isovaleric acidemia (IVA) may vary widely. There is limited collective information about dietetic management.

Aim

To describe European practice regarding the dietary management of IVA, prior to the availability of the E-IMD IVA guidelines (E-IMD 2014).

Methods

A cross-sectional questionnaire was sent to all European dietitians who were either members of the Society for the Study of Inborn Errors of Metabolism Dietitians Group (SSIEM-DG) or whom had responded to previous questionnaires on dietetic practice (n = 53). The questionnaire comprised 27 questions about the dietary management of IVA.

Results

Information on 140 patients with IVA from 39 centres was reported. 133 patients (38 centres) were given a protein restricted diet. Leucine-free amino acid supplements (LFAA) were routinely used to supplement protein intake in 58% of centres. The median total protein intake prescribed achieved the WHO/FAO/UNU [2007] safe levels of protein intake in all age groups. Centres that prescribed LFAA had lower natural protein intakes in most age groups except 1 to 10 y. In contrast, when centres were not using LFAA, the median natural protein intake met WHO/FAO/UNU [2007] safe levels of protein intake in all age groups. Enteral tube feeding was rarely prescribed.

Conclusions

This survey demonstrates wide differences in dietary practice in the management of IVA across European centres. It provides unique dietary data collectively representing European practices in IVA which can be used as a foundation to compare dietary management changes as a consequence of the first E-IMD IVA guidelines availability.

Practices in prescribing protein substitutes for PKU in Europe: No uniformity of approach

BACKGROUND

There appears little consensus concerning protein requirements in phenylketonuria (PKU).

METHODS

A questionnaire completed by 63 European and Turkish IMD centres from 18 countries collected data on prescribed total protein intake (natural/intact protein and phenylalanine-free protein substitute [PS]) by age, administration frequency and method, monitoring, and type of protein substitute. Data were analysed by European region using descriptive statistics.

RESULTS

The amount of total protein (from PS and natural/intact protein) varied according to the European region. Higher median amounts of total protein were prescribed in infants and children in Northern Europe (n=24 centres) (infants <1 year, >2-3g/kg/day; 1-3 years of age, >2-3 g/kg/day; 4-10 years of age, >1.5-2.5 g/kg/day) and Southern Europe (n=10 centres) (infants <1 year, 2.5 g/kg/day, 1-3 years of age, 2 g/kg/day; 4-10 years of age, 1.5-2 g/kg/day), than by Eastern Europe (n=4 centres) (infants <1 year, 2.5 g/kg/day, 1-3 years of age, >2-2.5 g/kg/day; 4-10 years of age, >1.5-2 g/kg/day) and with Western Europe (n=25 centres) giving the least (infants <1 year, >2-2.5 g/kg/day, 1-3 years of age, 1.5-2 g/kg/day; 4-10 years of age, 1-1.5 g/kg/day). Total protein prescription was similar in patients aged >10 years (1-1.5 g/kg/day) and maternal patients (1-1.5 g/kg/day).

CONCLUSIONS

The amounts of total protein prescribed varied between European countries and appeared to be influenced by geographical region. In PKU, all gave higher than the recommended 2007 WHO/FAO/UNU safe levels of protein intake for the general population.

Dietary management of urea cycle disorders: European practice

BACKGROUND

There is no published data comparing dietary management of urea cycle disorders (UCD) in different countries.

METHODS

Cross-sectional data from 41 European Inherited Metabolic Disorder (IMD) centres (17 UK, 6 France, 5 Germany, 4 Belgium, 4 Portugal, 2 Netherlands, 1 Denmark, 1 Italy, 1 Sweden) was collected by questionnaire describing management of patients with UCD on prescribed protein restricted diets.

RESULTS

Data for 464 patients: N-acetylglutamate synthase (NAGS) deficiency, n=10; carbamoyl phosphate synthetase (CPS1) deficiency, n=29; ornithine transcarbamoylase (OTC) deficiency, n=214; citrullinaemia, n=108; argininosuccinic aciduria (ASA), n=80; arginase deficiency, n=23 was reported. The majority of patients (70%; n=327) were aged 0-16y and 30% (n=137) >16y. Prescribed median protein intake/kg body weight decreased with age with little variation between disorders. The UK tended to give more total protein than other European countries particularly in infancy. Supplements of essential amino acids (EAA) were prescribed for 38% [n=174] of the patients overall, but were given more commonly in arginase deficiency (74%), CPS (48%) and citrullinaemia (46%). Patients in Germany (64%), Portugal (67%) and Sweden (100%) were the most frequent users of EAA. Only 18% [n=84] of patients were prescribed tube feeds, most commonly for CPS (41%); and 21% [n=97] were prescribed oral energy supplements.

CONCLUSIONS

Dietary treatment for UCD varies significantly between different conditions, and between and within European IMD centres. Further studies examining the outcome of treatment compared with the type of dietary therapy and nutritional support received are required.

Dietary practices in pyridoxine non-responsive homocystinuria: a European survey

BACKGROUND

Within Europe, the management of pyridoxine (B6) non-responsive homocystinuria (HCU) may vary but there is limited knowledge about treatment practice.

AIM

A comparison of dietetic management practices of patients with B6 non-responsive HCU in European centres.

METHODS

A cross-sectional audit by questionnaire was completed by 29 inherited metabolic disorder (IMD) centres: (14 UK, 5 Germany, 3 Netherlands, 2 Switzerland, 2 Portugal, 1 France, 1 Norway, 1 Belgium).

RESULTS

181 patients (73% >16 years of age) with HCU were identified. The majority (66%; n=119) were on dietary treatment (1-10 years, 90%; 11-16 years, 82%; and >16 years, 58%) with or without betaine and 34% (n=62) were on betaine alone. The median natural protein intake (g/day) on diet only was, by age: 1-10 years, 12 g; 11-16 years, 11 g; and >16 years, 45 g. With diet and betaine, median natural protein intake (g/day) by age was: 1-10 years, 13 g; 11-16 years, 20 g; and >16 years, 38 g. Fifty-two percent (n=15) of centres allocated natural protein by calculating methionine rather than a protein exchange system. A methionine-free l-amino acid supplement was prescribed for 86% of diet treated patients. Fifty-two percent of centres recommended cystine supplements for low plasma concentrations. Target treatment concentrations for homocystine/homocysteine (free/total) and frequency of biochemical monitoring varied.

CONCLUSION

In B6 non-responsive HCU the prescription of dietary restriction by IMD centres declined with age, potentially associated with poor adherence in older patients. Inconsistencies in biochemical monitoring and treatment indicate the need for international consensus guidelines.

Brain MRI findings as an important diagnostic clue in glutaric aciduria type 1

Glutaric aciduria type 1 is an autosomal recessive disorder caused by deficiency of glutaryl-coenzyme A dehydrogenase, with accumulation of glutaric acid, 3-hydroxyglutaric acid and glutaconic acid. Increased blood glutarylcarnitine levels are the basis for identification of affected infants by newborn screening. Despite the highly variability, this disease usually presents with an acute encephalitis-like encephalopathy in infancy or childhood after a period of normal development. The characteristic neurological sequel is a complex movement disorder due to acute bilateral striatal injury. Frequently, the only abnormality preceding the first episode is a progressive macrocephaly. Although neuroimaging findings are quite variable, the widening of the Sylvian fissures combined with abnormalities of the basal ganglia in a child with macrocephaly should raise the suspicion of this diagnosis. We describe two patients in whom macrocephaly was the only presenting symptom and whose diagnosis was suggested by the brain MRI findings. Our purpose is to illustrate the clinical value of neuroimaging in the diagnosis of glutaric aciduria type 1 even before the onset of neurologic symptoms, which is particularly important if newborn screening is not available.

Effects of extracts of selected medicinal plants upon hepatic oxidative stress

Aqueous extracts of a few medicinal plants traditionally used in Portugal have been assayed for their effects upon hepatic oxidative stress in mice. Previous in vitro studies had allowed characterization of agrimony, sage, savory, and raspberry in terms of overall antioxidant capacity and phenolic content. In the present study, the antioxidant effect and safety of these four plants were evaluated in vivo. For this purpose, mice ingested extracts in aqueous form (or water, used as the control) for 4 weeks; damage to lipids, proteins, and DNA was evaluated by oxidative cell biomarkers by the end of that period. Levels of hepatic glutathione and activities of enzymes involved in metabolism thereof were also determined. Finally, catalase and superoxide dismutase (SOD) activities were quantified, as these enzymes play a crucial role in antioxidant defense. When compared with the control, both raspberry and savory produced significant lipid protection; however, protein damage was significantly lower only in raspberry-treated animals. On the other hand, DNA damage was prevented only by savory. All plants led to a decrease in catalase activity, whereas all but sage also produced a decrease in SOD activity. With regard to glutathione levels and activities of enzymes involved in its metabolism, the aforementioned extracts exhibited different effects. In general, raspberry appeared to be the most promising extract, followed by savory, sage, and agrimony, sorted by decreasing performance in protection; the latter was even slightly toxic. Hence, the plants tested possess compounds with interesting biological activities that may support eventual inclusion in food or feed as functional additives.

Treatment options for small cell lung cancer - do we have more choice?

Small cell lung cancer (SCLC) is a significant health problem worldwide because of its high propensity for relapse. This review discusses existing and future therapies for the treatment of SCLC.

CYP3A5*3 genotypes and advanced non-small cell lung cancer development

21030

Background: Lung cancer is the most common cancer in Europe (381.500 new cases in 2004) and the third in the U.S.A (172.570 new cases in 2005). Smoking is one of the major causes of lung cancer: there are many procarcinogens present in tobacco smoke that, when activated, contribute to the development of this disease. The CYP3A subfamily represents a group of enzymes responsible for the metabolism of many currently used drugs, exogenous carcinogens and endogenous molecules such as steroids. Two of the major enzymes in this family, CYP3A4 and CYP3A5, activate polycyclic aromatic hydrocarbons such as benzo[a]pyrene and other procarcinogens present in tobacco smoke. Functional polymorphisms, such as CYP3A5*3 (associated with the lack of the CYP3A5 protein), could alter individual susceptibility to lung cancer. The aim of our study was to evaluate the influence of this polymorphism in the development of lung cancer. Methods: DNA samples were extracted from peripheral blood cells of 203 patients with non small cell lung cancer, including 42 non- smokers and 156 smokers or former smokers (no data available for the other 5 patients) and 162 blood donors. The CYP3A5*3 polymorphism was analysed through PCR-RFLP (SspI). Analysis of data was performed using the computer software SPSS for windows. The odds ratio (OR) and its 95% confidence interval (CI) were calculated as a measure of the association between CYP3A5*3 genotypes and NSCLC progression. Results: We found significant statistical differences between the control group and the patients with advanced stages (III and IV) of epidermoid and undifferentiated NSCLC (p=0.04; OR = 0.48; 95% CI = 0.232–0.977). Conclusions: Individual differences in the metabolism of carcinogens may influence the susceptibility to cancer development and behaviour. Our preliminary results suggest that the carriers CYP3A5*3 polymorphism are at lower risk of developing advanced lung cancer. This is probably due to a decreased activation of procarcinogens present in tobacco smoke in result of the lack of CYP3A5 caused by the CYP3A5*3 polymorphism. This is consistent with the hypothesis of a cumulative effect of carcinogens on the aggressive behaviour of the disease.

No significant financial relationships to disclose.

Doença de Dupuytren. Revisão de 100 doentes operados

A Doença de Dupuytren observa-se com frequência nesta região. Dada a sua incidência, a diminuição da capacidade de trabalho que pode provocar e o elevado número de casos tratados cirurgicamente, decidimos reavaliar os pacientes, tentando identificar factores etiológicos e o resultado do tratamento.

Foi efectuado um estudo de revisão clínico e de registos em processo de 100 casos, operados entre Fevereiro de 2002 e Dezembro de 2005 no Serviço de Ortopedia do Hospital do Vale do Sousa.

Após discussão com os ortopedistas assistentes, todos os dados relevantes recolhidos foram tratados estatisticamente em colaboração com o Serviço de Bioestatística da Faculdade de Medicina do Porto.

Os resultados são precedidos de uma perspectiva histórica e um sumário da etiologia, evolução, estadiamento, classificação e opções de tratamento da doença de Dupuytren.

Modulation of MPP+ uptake by tea and some of its components in Caco-2 cells

The entry of most xeno/endobiotics into the organism is limited by their intestinal absorption. The interference of certain foods with the therapeutic efficacy of drugs or with chemical toxicity is becoming evident and growing attention is being given to these subjects. The aim of this work was to study the effect of green tea (GT) and black tea (BT), as well as some of their components, on the transport of organic cation molecules. For this purpose, 3H-MPP+ (radiolabeled 1-methyl-4-phenylpyridinium) was used as a model organic cation and Caco-2 cells were used as an intestinal epithelial model. Our results showed that both GT and BT significantly increased 3H-MPP+ absorption in these cells. Additionally, we studied the effect of epigallocatechin-3-gallate (EGCG), myricetin, caffeine, and theophylline. Whereas EGCG (2 mM) increased, myricetin (50 microM) and caffeine (1 mM) decreased, and theophylline (1 mM) had no effect on the uptake of 3H-MPP+ into Caco-2 cells. When GT was supplemented with caffeine or theophylline, we observed a partial loss of its effect. When BT was supplemented with EGCG, its ability to increase 3H-MPP+ uptake was much more pronounced than that observed with BT alone. In conclusion, this study showed that GT and BT might interfere with the absorption of the model organic cation MPP+ by the intestinal epithelium. Since important compounds are organic cations, the consequences of this interference may have an impact on human health. Although this constitutes only preliminary work and further studies are needed, tea should be included in the growing list of foodstuffs that have the potential to be involved in food-drug interactions.

Pulsatile release and circadian rhythms of thyrotropin and prolactin in children with growth hormone deficiency

We have measured mean concentrations and have appraised the pulsatile nature of thyrotropin (TSH) and prolactin (PRL) release in children with classical GH deficiency (GHD; n = 4) and neurosecretory GH dysfunction (NSD; n = 4) and have compared the results with those obtained in children with constitutional delay (control; n = 4). Blood samples were obtained at 20-min intervals for 24 h. Pulse analysis of TSH and PRL was undertaken using the Cluster pulse detection algorithm. Circadian rhythmicity of TSH and PRL was assessed using cosinor analysis. The mean 24-h concentration of GH in the control subjects was significantly higher than that obtained in the GHD and NSD groups. With regard to TSH, the mean serum concentration in the GHD and NSD group were higher than that of the control subjects. This augmentation reflects TSH pulses of large amplitude and area, and a higher interpulse valley mean rather than a difference in peak number or peak duration. No differences in mean PRL concentration or characteristics of PRL pulses were found between the control and GHD and NSD subjects. When the 24 h data sets were divided into day (0800-2000 h) and night (2000-0800 h), the mean nighttime TSH concentration was higher than the daytime concentration in the control, GHD, and NSD groups. Although there were no day versus night differences in TSH pulse frequency in either group, peak amplitude, area, and interpulse valley means were increased during the night in the control group, and peak area, duration, and amplitude mean in the NSD group. The nighttime mean PRL concentrations in the control, GHD, and NSD subjects were higher than those found during the day. This increase was accounted for by increases in PRL peak amplitude, area in the control group, and peak area, amplitude, and interpulse valley mean in the GHD and NSD groups. Cosinor analysis of the 24-h TSH and PRL data revealed clear circadian rhythmicity in all groups of subjects. These data suggest that GHD and NSD are associated with an increase in pulsatile TSH secretion due to an increase in pulse amplitude and interpulse valley mean.