Absorption and intracellular accumulation of food-borne dicarbonyl precursors of advanced glycation end-product in a Caco-2 human cell transwell model

This study aimed to better understand whether and how the reactive 1,2-dicarbonyl precursors of advanced glycation end products (AGEs), glyoxal (GO) and methylglyoxal (MGO), cross the intestinal barrier by studying their transport in the in vitro Caco-2 transwell system. The results reveal that GO, MGO and Nε-(carboxymethyl)lysine (CML), the latter studied for comparison, are transported across the intestinal cell layer via both active and passive transport and accumulate in the cells, albeit all to a limited extent. Besides, the transport of the dicarbonyl compounds was only partially affected by the presence of amino acids and protein, suggesting that scavenging by a food matrix will not fully prevent their intestinal absorption. Our study provides new insights into the absorption of the two major food-borne dicarbonyl AGE precursors and provides evidence of their potential systemic bioavailability but also of factors limiting their contribution to the overall exposome.

Discrimination of Lipogenic or Glucogenic Diet Effects in Early-Lactation Dairy Cows Using Plasma Metabolite Abundances and Ratios in Combination with Machine Learning

During early lactation, dairy cows have a negative energy balance since their energy demands exceed their energy intake: in this study, we aimed to investigate the association between diet and plasma metabolomics profiles and how these relate to energy unbalance of course in the early-lactation stage. Holstein-Friesian cows were randomly assigned to a glucogenic (n = 15) or lipogenic (n = 15) diet in early lactation. Blood was collected in week 2 and week 4 after calving. Plasma metabolite profiles were detected using liquid chromatography-mass spectrometry (LC-MS), and a total of 39 metabolites were identified. Two plasma metabolomic profiles were available every week for each cow. Metabolite abundance and metabolite ratios were used for the analysis using the XGboost algorithm to discriminate between diet treatment and lactation week. Using metabolite ratios resulted in better discrimination performance compared with the metabolite abundances in assigning cows to a lipogenic diet or a glucogenic diet. The quality of the discrimination of performance of lipogenic diet and glucogenic diet effects improved from 0.606 to 0.753 and from 0.696 to 0.842 in week 2 and week 4 (as measured by area under the curve, AUC), when the metabolite abundance ratios were used instead of abundances. The top discriminating ratios for diet were the ratio of arginine to tyrosine and the ratio of aspartic acid to valine in week 2 and week 4, respectively. For cows fed the lipogenic diet, choline and the ratio of creatinine to tryptophan were top features to discriminate cows in week 2 vs. week 4. For cows fed the glucogenic diet, methionine and the ratio of 4-hydroxyproline to choline were top features to discriminate dietary effects in week 2 or week 4. This study shows the added value of using metabolite abundance ratios to discriminate between lipogenic and glucogenic diet and lactation weeks in early-lactation cows when using metabolomics data. The application of this research will help to accurately regulate the nutrition of lactating dairy cows and promote sustainable agricultural development.

Toxicokinetics of the Antidepressant Fluoxetine and Its Active Metabolite Norfluoxetine in Caenorhabditis elegans and Their Comparative Potency

The nematode Caenorhabditis elegans is a valuable model for ecotoxicological research, yet limited attention has been given to understanding how it absorbs, distributes, metabolizes, and excretes chemicals. This is crucial for C. elegans because the organism is known to have strong uptake barriers that are known to be susceptible to potential confounding effects of the presence of Escherichia coli as a food source. One frequently studied compound in C. elegans is the antidepressant fluoxetine, which has an active metabolite norfluoxetine. In this study, we evaluated the toxicokinetics and relative potency of norfluoxetine and fluoxetine in chemotaxis and activity tests. Toxicokinetics experiments were conducted with varying times, concentrations of fluoxetine, and in the absence or presence of E. coli, simulated with a one-compartment model. Our findings demonstrate that C. elegans can take up fluoxetine and convert it into norfluoxetine. Norfluoxetine proved slightly more potent and had a longer elimination half-life. The bioconcentration factor, uptake, and elimination rate constants depended on exposure levels, duration, and the presence of E. coli in the exposure medium. These findings expand our understanding of toxicokinetic modeling in C. elegans for different exposure scenarios, underlining the importance of considering norfluoxetine formation in exposure and bioactivity assessments of fluoxetine.

Comparison of the methylglyoxal scavenging effects of kaempferol and glutathione and the consequences for the toxicity of methylglyoxal in SH-SY5Y cells

This study aimed to characterize the methylglyoxal (MGO) scavenging capacity of glutathione (GSH) and kaempferol in more detail with special emphasis on the possible reversible nature of the adduct formation and their competition for MGO, and the safety consequences of their MGO-scavenging effects. GSH showed immediate and concentration-dependent MGO-scavenging effects, while the scavenging effects by kaempferol appeared concentration- but also time-dependent, with stable adducts formed over time. The GSH adduct gradually disappeared in a competition reaction with kaempferol, and kaempferol became the preferred scavenger over time. Furthermore, the scavenging of MGO by kaempferol provided better protection than GSH against extracellular MGO in SH-SY5Y cells. It is concluded that flavonoids like kaempferol provide better scavengers for food-borne MGO than thiol-based scavengers such as GSH, while, given the endogenous concentrations of both scavengers and the detoxification of the GSH-MGO adduct by the glyoxalase system, GSH will be dominant for intracellular MGO protection.

Deoxynivalenol increases pro-inflammatory cytokine secretion and reduces primary bile acid transport in an inflamed intestinal in vitro co-culture model

The fungal secondary metabolite deoxynivalenol (DON) that can contaminate cereal-based food products not only induces inflammation but also reduces bile acid absorption by a healthy human intestine. Bile acid malabsorption is commonly observed in individuals with an inflamed intestine. Here we studied the effects of DON on inflammation and primary bile acid transport using an in vitro model for an inflamed intestine. An inflamed intestinal in vitro model was established by co-culturing a Caco-2 cell-layer and LPS-pre-stimulated THP-1 macrophages in Transwells. We observed a decreased transport of 5 primary bile acids across inflamed co-cultures compared to healthy co-cultures but not of chenodeoxycholic acid. DON exposure further reduced the transport of the affected primary bile acids across the inflamed co-cultures. DON exposure also enhanced the secretion of pro-inflammatory cytokines in the inflamed co-cultures, while it did not increase the pro-inflammatory cytokines secretion from LPS-pre-stimulated THP-1 monocultures. Exposure of Caco-2 cell-layers to pro-inflammatory cytokines or THP-1 conditioned media partly mimicked the DON-induced effects of the co-culture model. Local activation of intestinal immune cells reinforces the direct pro-inflammatory effects of DON on intestinal epithelial cells. This affects the bile acid intestinal kinetics in an inflamed intestine.

On the Role of ROS and Glutathione in the Mode of Action Underlying Nrf2 Activation by the Hydroxyanthraquinone Purpurin

Purpurin is a major anthraquinone present in the roots of Rubia cordifolia (madder). Purpurin is known to activate Nrf2 (Nuclear transcription factor erythroid 2-related factor 2) EpRE (electrophile responsive element) mediated gene expression as a potential beneficial effect. This study aimed to elucidate the balance between the electrophilicity or pro-oxidant activity of purpurin underlying the Nrf2 induction. For this, Nrf2 activation with modified intracellular glutathione (GSH) levels was measured in an Nrf2 CALUX reporter gene assay. In addition, both cell-free and intracellular ROS formation of purpurin with modified (intracellular) GSH levels at different pH were quantified using the DCF-DA assay. GSH adduct formation was evaluated by UPLC and LC-TOF-MS analysis. GSH and GSSG levels following purpurin incubations were quantified by LC-MS/MS. We show that Nrf2 induction by purpurin was significantly increased in cells with buthionine sulfoximine depleted GSH levels, while Nrf2 induction was decreased upon incubation of the cells with N-acetylcysteine being a precursor of GSH. In cell-free incubations, ROS formation increased with increasing pH pointing at a role for the deprotonated form of purpurin. Upon incubations of purpurin with GSH at physiological pH, GSH adduct formation appeared negligible (<1.5% of the added purpurin). The addition of GSH resulted in conversion of GSH to GSSG and significantly reduced the ROS formation. Together these results demonstrate that Nrf2 induction by purpurin originates from intracellular ROS formation and not from its electrophilicity, which becomes especially relevant when intracellular GSH levels can no longer scavenge the ROS. The present study demonstrated that the efficiency of intracellular Nrf2 activation by purpurin and related anthraquinones will depend on (i) their pKa and level of deprotonation at the intracellular pH, (ii) the oxidation potential of their deprotonated form and (iii) the intracellular GSH levels. Thus, the Nrf2 induction by purpurin depends on its pro-oxidant activity and not on its electrophilicity.

Ribotoxin deoxynivalenol induces taurocholic acid malabsorption in an in vitro human intestinal model

The trichothecene toxin deoxynivalenol (DON) is a ribotoxic mycotoxin that contaminates cereal-based food. DON binds to ribosomes, thereby inhibiting protein translation and activating stress mitogen-activated protein kinases (MAPK). The activation of MAPK induces pro-inflammatory cytokine production. Emerging evidence showed that DON decreased bile acid reabsorption and apical sodium-dependent bile acid transporter (ASBT) expression in Caco-2 cell layers. We hypothesized that the effect of DON on decreased ASBT mRNA expression is regulated via pro-inflammatory cytokines. We observed that MAPK inhibitors prevented DON to induce IL-8 secretion and prevented the DON-induced downregulation of ASBT mRNA expression. However, DON-induced taurocholic acid (TCA) transport reduction was not prevent by the MAPK inhibitors. We next observed a similarity between the activity of the non-inflammatory ribotoxin cycloheximide and DON to decrease TCA transport, which is consistent with their common ability to inhibit protein synthesis. Together, our results suggest that DON-induced TCA malabsorption is regulated by MAPK activation-induced pro-inflammatory cytokine production and protein synthesis inhibition, both of which are initiated by DON binding to the ribosomes which therefore is the molecular initiating event for the adverse outcome of bile acid malabsorption. This study provides insights into the mechanism of ribotoxins-induced bile acid malabsorption in human intestine.

Induction of Nrf2-EpRE-mediated gene expression by hydroxyanthraquinones present in extracts from traditional Chinese medicine and herbs

Hydroxyanthraquinones that can be present in traditional Chinese medicine (TCM) and herbal extracts have claimed beneficial intestinal effects. We examined the ability of a panel hydroxyanthraquinones, and methanolic extracts from selected TCM and herbal granules to activate Nrf2-EpRE mediated gene expression using a reporter-gene assay. The results indicate that purpurin, aloe-emodin, 2-hydroxy-3-methylanthraquinone and rhein induced Nrf2 mediated gene expressions with a high induction factor (IFs>10), with BMCL₁₀ values (the lower confidence limit of the concentration giving 10% added response above background) of 16 μM, 1.1 μM, 23 μM and 2.3 μM, respectively, while aurantio-obtusin, obtusifolin, rubiadin 1-methyl ether and emodin were less potent (IFs<5), with BMCL₁₀ values for added response above background level of 4.6 μM, 15 μM, 9.8 μM and 3.8 μM, respectively. All TCM extracts and the herbal extracts of Aloe Vera, Polygonum multiflorum, Rubia (cordifolia) and Rheum officinale activated the Nrf2-EpRE pathway. Of the TCM extracts, Chuan-Xin-Lian-Kang-Yan-Pian was the most potent Nrf2-inducer. LC-MS/MS analysis indicated the presence of selected hydroxyanthraquinones in the extracts and herbs, in part explaining their Nrf2-EpRE mediated activity. In conclusion, different hydroxyanthraquinones have different potencies of Nrf2 activation. The Nrf2 activation by extracts from TCM and herbs can be partially explained by the presence of selected hydroxyanthraquinones.

In vitro models to measure effects on intestinal deconjugation and transport of mixtures of bile acids

Bile acid metabolism and transport are critical to maintain bile acid homeostasis and host health. In this study, it was investigated if effects on intestinal bile acid deconjugation and transport can be quantified in vitro model systems using mixtures of bile acids instead of studying individual bile acids. To this end deconjugation of mixtures of selected bile acids in anaerobic rat or human fecal incubations and the effect of the antibiotic tobramycin on these reactions was studied. In addition, the effect of tobramycin on the transport of the bile acids in isolation or in a mixture across Caco-2 cell layers was characterized. The results demonstrate that both the reduction of bile acid deconjugation and transport by tobramycin can be adequately detected in vitro systems using a mixture of bile acids, thus eliminating the need to characterize the effects for each bile acid in separate experiments. Subtle differences between the experiments with single or combined bile acids point at mutual competitive interactions and indicate that the use of bile acid mixtures is preferred over use of single bile acid given that also in vivo bile acids occurs in mixtures.

In vitro models to detect in vivo bile acid changes induced by antibiotics

Bile acid homeostasis plays an important role in many biological activities through the bile-liver-gut axis. In this study, two in vitro models were applied to further elucidate the mode of action underlying reported in vivo bile acid changes induced by antibiotics (colistin sulfate, tobramycin, meropenem trihydrate, and doripenem hydrate). 16S rRNA analysis of rat fecal samples anaerobically incubated with these antibiotics showed that especially tobramycin induced changes in the gut microbiota. Furthermore, tobramycin was shown to inhibit the microbial deconjugation of taurocholic acid (TCA) and the transport of TCA over an in vitro Caco-2 cell layer used as a model to mimic intestinal bile acid reuptake. The effects induced by the antibiotics in the in vitro model systems provide novel and complementary insight explaining the effects of the antibiotics on microbiota and fecal bile acid levels upon 28-day in vivo treatment of rats. In particular, our results provide insight in the mode(s) of action underlying the increased levels of TCA in the feces upon tobramycin exposure. Altogether, the results of the present study provide a proof-of-principle on how in vitro models can be used to elucidate in vivo effects on bile acid homeostasis, and to obtain insight in the mode(s) of action underlying the effect of an antibiotic, in this case tobramycin, on bile acid homeostasis via effects on intestinal bile acid metabolism and reuptake.

Inter- and Intraindividual Differences in the Capacity of the Human Intestinal Microbiome in Fecal Slurries to Metabolize Fructoselysine and Carboxymethyllysine

The advanced glycation endproduct carboxymethyllysine and its precursor fructoselysine are present in heated, processed food products and are considered potentially hazardous for human health. Upon dietary exposure, they can be degraded by human colonic gut microbiota, reducing internal exposure. Pronounced interindividual and intraindividual differences in these metabolic degradations were found in anaerobic incubations with human fecal slurries in vitro. The average capacity to degrade fructoselysine was 27.7-fold higher than that for carboxymethyllysine, and degradation capacities for these two compounds were not correlated (R² = 0.08). Analysis of the bacterial composition revealed that interindividual differences outweighed intraindividual differences, and multiple genera were correlated with the individuals' carboxymethyllysine and fructoselysine degradation capacities (e.g., Akkermansia, Alistipes).

Hepatic bile acid synthesis and secretion: Comparison of in vitro methods

Reliable hepatic in vitro systems are crucial for the safety assessment of xenobiotics. Certain xenobiotics decrease the hepatic bile efflux, which can ultimately result in cholestasis. Preclinical animal models and the currently available in vitro systems poorly predict a xenobiotic's cholestatic potential. Here, we compared the phenotype and capacity of three liver derived in vitro systems to emulate human functionality to synthesize and secrete bile acids (BAs). To this end, basal BA production of sandwich cultured human hepatocytes (SCHHs), HepaRG cells (HepaRGs) and hepatocyte-like intrahepatic cholangiocyte organoids (ICO-heps) were analysed, and the effect of the known BSEP (Bile Salt Export Pump)-inhibitors bosentan and lopinavir on BA disposition in SCHHs and HepaRGs was quantified. RT-qPCR of selected target genes involved in maturation status, synthesis, transport and conjugation of BAs was performed to mechanistically underpin the observed differences in BA homeostasis. ICO-heps produced a (very) low amount of BAs. SCHHs are a powerful tool in cholestasis-testing due to their high basal BA production and high transporter expression compared to the other models tested. HepaRGs were responsive to both selected BSEP-inhibitors and produced a BA profile that is most similar to the human in vivo situation, making them a suitable and practical candidate for cholestasis-testing.

Exposure to the mycotoxin deoxynivalenol reduces the transport of conjugated bile acids by intestinal Caco-2 cells

Conjugated bile acids are synthesized in liver and subsequently secreted into the intestinal lumen from which they are actively reabsorbed and transported back to liver. The efficient enterohepatic circulation of conjugated bile acids is important to maintain homeostasis. The mycotoxin deoxynivalenol (DON) is a fungal secondary metabolite that contaminates cereal food. Upon human exposure, it can cause intestinal dysfunction. We explored the effects of DON exposure on the intestinal absorption of conjugated bile acids and the expression of bile acid transporters using an in vitro model based on Caco-2 cell layers grown in transwells. Our study shows that the transport rate of taurocholic acid (TCA) is decreased after 48-h pre-exposure of the Caco-2 cells to 2 µM DON, which is a realistic intestinal DON concentration. Exposure to DON downregulates expression of the genes coding for the apical sodium-dependent bile acid transporter (ASBT), the ileal bile acid-binding protein (IBABP) and the organic solute transporter α (OSTα), and it counteracts the agonist activity of Farnesoid X receptor (FXR) agonist GW4064 on these genes. In addition, the transport of ten taurine or glycine-conjugated bile acids in a physiological relevant mixture by the intestinal Caco-2 cell layers was decreased after pre-exposure of the cells to DON, pointing at a potential for DON-mediated accumulation of the conjugated bile acids at the intestinal luminal side. Together the results reveal that DON inhibits intestinal bile acid reabsorption by reducing the expression of bile acid transporters thereby affecting bile acid intestinal kinetics, leading to bile acid malabsorption in the intestine. Our study provides new insights into the hazards of DON exposure.

P112 INCIDENTAL INGUINAL HERNIA IN MEN

Aim

“Ultrasound may contribute to establish the cause of nonspecific groin complaints. However, the risk is diagnosing an incidental inguinal hernia whereas the pain has an alternative cause. Overtreatment is to be prevented. Therefore, the aim of this study is to determine the prevalence of a previously unknown inguinal hernia among working-age men without groin complaints.”

Material and Methods

“A cross sectional study was conducted in healthy men aged 45-67 years. Men with a Body Mass Index (BMI) &gt; 40, a history of groin complaints, a known inguinal hernia or previous inguinal surgery were excluded. Ultrasound of both groins was performed in supine position with and without a Valsalva manoeuvre by a specialised ultrasound technician in consultation with a radiologist. In all groin ultrasounds showing an inguinal hernia, physical examination was executed by a hernia surgeon.”

Results

“In the months June and November of 2018, 200 groins of 100 men were analysed. In 16 (16%) men an inguinal hernia was found on groin ultrasound (95% confidence interval [8.8 – 23.2]). In 12 men this was a unilateral inguinal hernia and in 4 men a bilateral inguinal hernia. Ultrasound yielded no other pathology.”

Conclusions

“In a population of men aged 40-67 years without groin complaints, ultrasound detects an inguinal hernia in 16%. Hence, the probability of wrongly attributing groin complaints to an incidental inguinal hernia, diagnosed on ultrasound, is considerable. ”

Maternal and perinatal outcomes of dichorionic diamniotic twins in women after spontaneous and assisted conception

OBJECTIVE

Twin pregnancies have been shown to be associated with numerous maternal and perinatal complications. Published data shows conflicting reports on whether assisted conception influences these risks. The purpose of this study was to assess the impact of mode of conception on maternal and perinatal outcomes of dichorionic diamniotic twin pregnancies.

STUDY DESIGN

This was a large retrospective study of 497 women with dichorionic diamniotic twins that were conceived spontaneously or with assisted conception in a single centre over a 10-year period.

RESULTS

This study showed no significant difference in mode of delivery (OR 1.40 95% CI 0.88 - 2.24), need for admission to neonatal unit (OR 1.56 95% CI 0.88-2.77), or preterm births between dichorionic twin pregnancies conceived following assisted conception when compared to spontaneously conceived dichorionic twin pregnancies. Women who conceived twins by assisted conception that did not have an elective caesarean section were more likely to go into spontaneous labour than have an induction of labour (OR 0.54 95% CI 0.3 - 0.99). They also had a higher chance of having an estimated blood loss of more than 1L than women who conceived naturally (OR 1.70 95% CI 1.06 - 2.73).

CONCLUSIONS

In the case of dichorionic twins, this study showed that assisted conception does not seem to be associated with adverse obstetric and perinatal outcomes when compared with spontaneous conception. These results should be considered reassuring to women undergoing assisted conception, and may assist clinicians when counselling patients for assisted conception treatment. Further research is needed to assess the impact of assisted conception on postpartum blood loss.

Management of prolonged first stage of labour in a low-resource setting: lessons learnt from rural Malawi

Background

Caesarean sections without medical indication cause substantial maternal and perinatal ill-health, particularly in low-income countries where surgery is often less safe. In presence of adequate labour monitoring and by appropriate use of evidence-based interventions for prolonged first stage of labour, unnecessary caesarean sections can be avoided. We aim to describe the incidence of prolonged first stage of labour and the use of amniotomy and augmentation with oxytocin in a low-resource setting in Malawi.

Methods

Retrospective analysis of medical records and partographs of all women who gave birth in 2015 and 2016 in a rural mission hospital in Malawi. Primary outcomes were incidence of prolonged first stage of labour based on partograph tracings, caesarean section indications and utilization of amniotomy and oxytocin augmentation.

Results

Out of 3246 women who gave birth in the study period, 178 (5.2%) crossed the action line in the first stage of labour, of whom 21 (11.8%) received oxytocin to augment labour. In total, 645 women gave birth by caesarean section, of whom 241 (37.4%) with an indication ‘prolonged first stage of labour’. Only 113 (46.9%) of them crossed the action line and in 71/241 (29.5%) membranes were still intact at the start of caesarean section. Excluding the 60 women with prior caesarean sections, 14/181 (7.7%) received oxytocin prior to caesarean section for augmentation of labour.

Conclusion

The diagnosis prolonged first stage of labour was often made without being evident from labour tracings and two basic obstetric interventions to prevent caesarean section, amniotomy and labour augmentation with oxytocin, were underused.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03856-9.

Health workers' perspectives on informed consent for caesarean section in Southern Malawi

Objective

Informed consent is a prerequisite for caesarean section, the commonest surgical procedure in low- and middle-income settings, but not always acquired to an appropriate extent. Exploring perceptions of health care workers may aid in improving clinical practice around informed consent. We aim to explore health workers’ beliefs and experiences related to principles and practice of informed consent.

Methods

Qualitative study conducted between January and June 2018 in a rural 150-bed mission hospital in Southern Malawi. Clinical observations, semi-structured interviews and a focus group discussion were used to collect data. Participants were 22 clincal officers, nurse-midwives and midwifery students involved in maternity care. Data were analysed to identify themes and construct an analytical framework.

Results

Definition and purpose of informed consent revolved around providing information, respecting women’s autonomy and achieving legal protection. Due to fear of blame and litigation, health workers preferred written consent. Written consent requires active participation by the consenting individual and was perceived to transfer liability to that person. A woman’s refusal to provide written informed consent may pose a dilemma for the health worker between doing good and respecting autonomy. To prevent such refusal, health workers said to only partially disclose surgical risks in order to minimize women's anxiety. Commonly perceived barriers to obtain a fully informed consent were labour pains, language barriers, women’s lack of education and their dependency on others to make decisions.

Conclusions

Health workers are familiar with the principles around informed consent and aware of its advantages, but fear of blame and litigation, partial disclosure of risks and barriers to communication hamper the process of obtaining informed consent. Findings can be used to develop interventions to improve the informed consent process.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12910-021-00584-9.

Impact of Medical Doctors Global Health and Tropical Medicine on decision-making in caesarean section: a pre- and post-implementation study in a rural hospital in Malawi

BACKGROUND

Medical doctors with postgraduate training in Global Health and Tropical Medicine (MDGHTM) from the Netherlands, a high-income country with a relatively low caesarean section rate, assist associate clinicians in low-income countries regarding decision-making during labour. Objective of this study was to assess impact of the presence of MDGHTMs in a rural Malawian hospital on caesarean section rate and indications.

METHODS

This retrospective pre- and post-implementation study was conducted in a rural hospital in Malawi, where MDGHTMs were employed from April 2015. Indications for caesarean section were audited against national protocols and defined as supported or unsupported by these protocols. Caesarean section rates and numbers of unsupported indications for the years 2015 and 2016 per quarter for different staff cadres were assessed by linear regression.

RESULTS

Six hundred forty-five women gave birth by caesarean section in the study period. The caesarean rate dropped from 20.1 to 12.8% (p < 0.05, R² = 0.53, y = - 0.0086x + 0.2295). Overall 132 of 501 (26.3%) auditable indications were not supported by documentation in medical records. The proportion of unsupported indications dropped significantly over time from 47.0 to 4.4% (p < 0.01, R² = 0.71, y = - 0.0481x + 0.4759). Stratified analysis for associate clinicians only (excluding caesarean sections performed by medical doctors) showed a similar decrease from 48.3 to 6.5% (p < 0.05, R² = 0.55, y = - 0.0442x + 0.4805).

CONCLUSIONS

Our results indicate that presence of MDGHTMs was accompanied by considerable decreases in caesarean section rate and proportion of unsupported indications for caesarean section in this facility. Their presence is likely to have influenced decision-making by associate clinicians.

Pre-post implementation survey of a multicomponent intervention to improve informed consent for caesarean section in Southern Malawi

OBJECTIVE

Surgical informed consent is essential prior to caesarean section, but potentially compromised by insufficient communication. We assessed the association between a multicomponent intervention and women's recollection of information pertaining to informed consent for caesarean section in a low-resource setting, thereby contributing to respectful maternity care.

DESIGN

Pre-post implementation survey, conducted from January to June 2018, surveying women prior to discharge.

SETTING

Rural 150-bed mission hospital in Southern Malawi.

PARTICIPANTS

A total of 160 postoperative women were included: 80 preimplementation and 80 postimplementation.

INTERVENTION

Based on observed deficiencies and input from local stakeholders, a multicomponent intervention was developed, consisting of a standardised checklist, wall poster with a six-step guide and on-the-job communication training for health workers.

PRIMARY AND SECONDARY OUTCOME MEASURES

Individual components of informed consent were: indication, explanation of procedure, common complications, implications for future pregnancies and verbal enquiry of consent, which were compared preintervention and postintervention using χ² test. Generalised linear models were used to analyse incompleteness scores and recollection of the informed consent process.

RESULTS

The proportion of women who recollected being informed about procedure-related risks increased from 25/80 to 47/80 (OR 3.13 (95% CI 1.64 to 6.00)). Recollection of an explanation of the procedure changed from 44/80 to 55/80 (OR 1.80 (0.94 to 3.44)), implications for future pregnancy from 25/80 to 47/80 (1.69 (0.89 to 3.20)) and of consent enquiry from 67/80 to 73/80 (OR 2.02 (0.73 to 5.37)). After controlling for other variables, incompleteness scores postintervention were 26% lower (Exp(β)=0.74; 95% CI 0.57 to 0.96). Recollection of common complications increased with 0.25 complications (β=0.25; 95% CI 0.01 to 0.49). Recollection of the correct indication did not differ significantly.

CONCLUSION

Recollection of informed consent for caesarean section changed significantly in the postintervention group. Obtaining informed consent for caesarean section is one of the essential components of respectful maternity care.

ST-Vector Orientation and Location of Myocardial Perfusion Defects during Exercise

In 34 patients with chest pain the spatial orientation of the ST-vectors in the exercise electrocardiogramm 30 and 80 msec after the end of QRS were compared with the location of exercise induced local defects of myocardial uptake of 201T1. The following results were obtained:

1. The sensitivity and specifity of myocardial perfusion imaging after exercise were the same as those of exercise electrocardiograms;

2. No relation could be observed between the location of reduced 201T1 uptake during exercise and the spatial orientation of the ST-vectors.

Nanoparticular surface-bound PCBs, PCDDs, and PCDFs-a novel class of potentially higher toxic POPs

In a previous study, Env Sci Poll Res:1-7, 2015 showed that polychlorinated biphenyls (PCBs), polychlorinated dibenzo dioxins (PCDDs), and polychlorinated dibenzo furanes (PCDFs) are found in commercially available (nano) particular titanium dioxide as a result of the fabrication. Here, we give a brief perspective and reason the toxicity of these new classes of persistent organic pollutants (POPs) by reviewing also their nanoparticular properties, such as surface-to-volume ratio, photocatalytic activity, polarity shifts, and stealth effect. These insights point towards a new class of POPs and toxicologic effects, which are related to the size but not a result of nanotechnology itself. We pave the way to the understanding of until now unresolved very complex phenomena, such as the indoor exposure, formation, and transformation of POP and sick-building syndrome. This is a fundamental message for nanotoxicology and kinetics and should be taken into account when determining the toxicity of nanomaterials and POPs separately and as a combination.

PCDDs, PCDFs, and PCBs co-occurrence in TiO2 nanoparticles

In the present study, we report on the co-occurrence of persistent organic pollutants (POPs) adsorbed on nanoparticular titanium dioxide (TiO2). We report on the finding of polychlorinated dibenzodioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) on the surface of commercially available TiO2 nanoparticles, being formed during the fabrication process of the TiO2. Thereby, the samples comprise PCBs with higher congener numbers or, in the absence of PCBs, a high concentration of PCDDs and PCDFs. This new class of POPs on an active catalytic surface and the great range of applications of nanoparticular TiO2, such as in color pigments, cosmetics, and inks, give rise to great concern due to their potential toxicity.

Health workers' perceptions of obstetric critical incident audit in Thyolo District, Malawi

OBJECTIVE

To assess perceptions held by health workers in a Malawian district about obstetric critical incident audit. Insight into factors contributing to participation and endorsement may help to improve the audit process and reduce facility-based maternal and neonatal mortality and morbidity.

METHODS

This study involves semi-structured interviews with 25 district health workers, a focus group discussion and observation of audit sessions in health facilities in Thyolo District, Malawi, between August 2009 and January 2010. Data were analysed with maxqda 2010.

RESULTS

Findings were categorized into four major areas: (i) general knowledge of audit, (ii) participation in local audit and feedback sessions, (iii) the ability to reproduce the local audit cycle and (iv) effects and outcomes of audit and feedback. All health workers were familiar with the concept of audit and could reproduce the local cycle. Most health workers classified audit as an instructive and helpful tool to improve the quality of their work, provided that it is performed in a manner that enhances motivation and on-the-job learning.

CONCLUSIONS

Contradictory to recent reports from other African settings, which showed negative effects of audit on health workers' motivation, staff in this district considered audit and feedback valuable tools to enhance the quality of the care they provide. Audit has become part of the professional routine in the district, and its educational value was considered its most important appeal.

The effect of high tibial osteotomy on the results of total knee arthroplasty: a matched case control study

Background

We performed a matched case control study to assess the effect of prior high tibia valgus producing osteotomy on results and complications of total knee arthroplasty (TKA).

Methods

From 1996 until 2003 356 patients underwent all cemented primary total knee replacement in our institution. Twelve patients with a history of 14 HTO were identified and matched to a control group of 12 patients with 14 primary TKA without previous HTO. The match was made for gender, age, date of surgery, body mass index, aetiology and type of prosthesis. Clinical and radiographic outcome were evaluated after a median duration of follow-up of 3.7 years (minimum, 2.3 years). The SPSS program was used for statistical analyses.

Results

The index group had more perioperative blood loss and exposure difficulties with one tibial tuberosity osteotomy and three patients with lateral retinacular releases. No such procedures were needed in the control group. Mid-term HSS, KSS and WOMAC scores were less favourable for the index group, but these differences were not significant. The tibial slope of patients with prior HTO was significantly decreased after this procedure. The tibial posterior inclination angle was corrected during knee replacement but posterior inclination was significantly less compared to the control group. No deep infection or knee component loosening were seen in the group with prior HTO.

Conclusion

We conclude that TKA after HTO seems to be technically more demanding than a primary knee arthroplasty, but clinical outcome was almost identical to a matched group that had no HTO previously.

OctreoTher: ongoing early clinical development of a somatostatin-receptor-targeted radionuclide antineoplastic therapy

OctreoTher ((90)Y-DOTA-D-Phe(1)-Tyr(3)-octreotide, a.k.a. (90)Y-SMT 487) consists of a somatostatin peptide analogue (Tyr(3)-octreotide), coupled with a complexing moiety (DOTA), and labeled with a tightly bound beta-emitter (yttrium-90). By targeting somatostatin receptor-positive tumors (as imaged by OctreaScan it may deliver a tumoricidal dose of radiation. Phase I clinical trials, conducted in patients with neuroendocrine tumors, established the safety and tolerability of the dose selected for further study and demonstrated the capacity of OctreoTher to deliver radiation doses to tumors that resulted in significant neuroendocrine tumor shrinkage. Novartis-sponsored phase II studies will soon begin to test the efficacy of OctreoTher in breast and small cell lung cancer. A fixed-dose regimen of 120 mCi/cycle x 3 cycles administered with concomitant amino acid infusion has been chosen for the study. Phase I data and published literature support that this fixed dose regimen will be safely tolerated.

Clinical and genetic studies on 12 preaxial polydactyly families and refinement of the localisation of the gene responsible to a 1.9 cM region on chromosome 7q36

Polydactyly is the most frequently observed congenital hand malformation with a prevalence between 5 and 19 per 10000 live births. It can occur as an isolated disorder, in association with other hand/foot malformations, or as a part of a syndrome, and is usually inherited as an autosomal dominant trait. According to its anatomical location, polydactyly can be generally subdivided into pre- and postaxial forms. Recently, a gene responsible for preaxial polydactyly types II and III, as well as complex polysyndactyly, has been localised to chromosome 7q36. In order to facilitate the search for the underlying genetic defect, we ascertained 12 additional families of different ethnic origin affected with preaxial polydactyly. Eleven of the kindreds investigated could be linked to chromosome 7q36, enabling us to refine the critical region for the preaxial polydactyly gene to a region of 1.9 cM. Our findings also indicate that radial and tibial dysplasia/aplasia can be associated with preaxial polydactyly on chromosome 7q36. Combining our results with other studies suggests that all non-syndromic preaxial polydactylies associated with triphalangism of the thumb are caused by a single genetic locus, but that there is genetic heterogeneity for preaxial polydactyly associated with duplications of biphalangeal thumbs. Comparison of the phenotypic and genetic findings of different forms of preaxial polydactyly is an important step in analysing and understanding the aetiology and pathogenesis of these limb malformations.

Expression of adhesion molecules on granulocytes and monocytes from patients with asthma stimulated in vitro with interleukin-8 and monocyte chemotactic protein-1

Upregulation of adhesion molecule expression on endothelial cells (EC) and circulating leukocytes, by locally produced inflammatory mediators, may result in the enhanced infiltration of leukocytes into tissue, e.g. the airways of asthma patients. The present study investigates whether the expression of adhesion molecules on granulocytes and monocytes from asthma patients is affected by chemotactic factors, i.e. interleukin-8 (IL-8) and monocyte chemotactic protein-1 (MCP-1). Flow cytometric analysis showed that the intrinsic expression of the various adhesion molecules on peripheral blood phagocytes from asthma patients was not different from that of healthy individuals. However, stimulation of monocytes with MCP-1 resulted only in upregulation of the expression of CD14 on monocytes from symptomatic asthma patients but not on monocytes from asymptomatic asthma patients and healthy individuals. Stimulation of granulocytes with IL-8 did not change the expression of the various beta 1- and beta 2-integrin molecules, such as VLA-4, LFA-1, CR3 and p150,95. Since earlier studies have shown that CD14 on monocytes mediates monocyte adhesion to activated vascular EC the present findings suggest that during the active phase of asthma upregulation of CD14 on monocytes by MCP-1 may lead to an increased adhesion of monocytes to vascular endothelium and their subsequent transendothelial migration into the tissue of the airways.

Effect of interleukin-8 and monocyte chemotactic protein-1 on adhesion of circulating granulocytes and monocytes from asthma patients to human venous endothelial cells

The adhesive interactions between phagocytes and endothelial cells (EC) can be modulated by inflammatory cytokines and chemotactic proteins which are released during an inflammatory response. The aim of the present study was to investigate first whether the adhesive properties of granulocytes and monocytes from asthma patients for vascular endothelial cells differ from those of phagocytes from healthy individuals. Furthermore, we studied whether the chemokines interleukin-8 (IL-8) and monocyte chemotactic protein-1 (MCP-1) can affect the binding of phagocytes to EC. No differences were observed in binding of phagocytes from asymptomatic or symptomatic asthma patients and from healthy individuals to non-stimulated or cytokine-stimulated EC. Incubation of granulocytes with IL-8 did not influence their adhesion to non-stimulated EC but inhibited the adhesion of granulocytes to IL-1-stimulated EC. Incubation of monocytes with MCP-1 did not affect their adhesion to non-stimulated or cytokine-stimulated EC. Our results indicate that adhesion of phagocytes to EC depends on the activation state of the endothelial cells but not on the origin of the phagocytes, since there were no differences in the adhesion of phagocytes from asthma patients and healthy individuals to non-stimulated or cytokine-stimulated EC.

Continuous infusion of ceftazidime in cystic fibrosis patients during home treatment: clinical outcome, microbiology and pharmacokinetics

Acute exacerbations of Pseudomonas aeruginosa lung infections were treated with ceftazidime by continuous infusion in 17 adult patients with cystic fibrosis at home. Ceftazidime was delivered via an infusion pump and the effects of this 3 week home intravenous antibiotic treatment (HIVAT) were prospectively studied over a 2 year period. Patients with cystic fibrosis (eight male and nine female patients; mean age 26.9 +/- 7.6 years, range 15-52 years), received a total of 33 courses of continuous ceftazidime (100 mg/kg/24 h). Clinical data were collected at the start, the end and 4-6 weeks after the end of treatment in 12 patients. Ceftazidime pharmacokinetic data during continuous infusion were obtained from ten patients. The treatment was supervised by the clinician without home visits. All 25 clinically evaluable courses in 12 patients proved efficacious. The mean duration of the courses was 21 days. The entire antibiotic course was administered at home in 88% of the courses. The other 12% was started for 2-3 days as an inpatient. Objective clinical parameters significantly improved. Clinical improvement was noted in 91% of the patients, and lasted at least until 4-6 weeks after the end of the treatment in 70%. The number of cultures positive for P. aeruginosa decreased significantly during antibiotic treatment. Bacterial count returned to pretreatment values 4-6 weeks after treatment. Multiple courses of ceftazidime monotherapy did not result in a lasting increase of ceftazidime-resistant pseudomonas strains. Total body clearance was 9.1 +/- 1.3 L/h. The steady-state ceftazidime serum concentration during continuous infusion was 28.4 +/- 5.0 mg/L. Sputum concentrations were in the range of 0.5-13 mg/L (3.9 +/- 4.0 mg/L). In conclusion, HIVAT with ceftazidime administered by continuous infusion proved clinically effective and did not result in an increase in lasting resistance.

Pharmacokinetics of aerosolized tobramycin in adult patients with cystic fibrosis

This study was performed to determine the clinical pharmacokinetics of tobramycin in six patients with cystic fibrosis (CF) after inhalation of 600 mg. Tobramycin was administered with an ultrasonic nebulizer (WISTO SENIOR). Blood and urine were sampled until 24 h after inhalation. Maximum tobramycin levels in serum varied from 0.19 to 2.57 mg/liter (mean 1.27 mg/liter; standard deviation, 1.07 mg/liter). Systemic availability (calculated from urinary output) ranged from 6.0 to 27.4% (mean, 17.5%; standard deviation, 8.8%). The results illustrate that, provided that the systemic availability of tobramycin is a reflection of pulmonary deposition, inhalation studies with CF patients should have a concentration-controlled design. Furthermore, reliance on dose recommendations from the literature for a new patient starting on this treatment is not justified, but it is mandatory that deposition kinetics be studied for each patient and for each nebulizer. It may well be that, with higher levels of deposition, dosages lower than those recommended in the literature will suffice to obtain the desired clinical effect. In addition, the reverse may also be the case.

The nonhospital costs of care of patients with CF in The Netherlands: results of a questionnaire

Cystic fibrosis (CF) causes a relatively high medical consumption. A large part of the treatment takes place at home. Because data regarding nonhospital care are lacking, we wished to determine the costs of care of patients with CF outside the hospital. A questionnaire was sent to 73 patients with CF from two Dutch hospitals (response rate 64%, 14 children and 33 adults). Average consumption and average costs per patient per year were calculated for children and adults for six categories: nonhospital medical care; domestic help; diet; travelling because of CF; medication; and devices and special facilities at home, work or school. The average nonhospital costs of care amounted to Pounds 4,641 per child per year (range Pounds 712-13,269) and Pounds 10,242 per adult (range Pounds 1,653-26,571). Nonhospital medical care for children and adults accounted for, respectively, 8 and 5% of these costs, domestic help for 15 and 9%, diet for 10 and 7%, travelling because of CF for 4 and 8%, medication for 63 and 67%, and devices and special facilities at home, work or school for 1 and 4%. Nonhospital costs of care of cystic fibrosis are very high and amount to 50% of the total (medical and nonmedical) lifetime costs of cystic fibrosis.

Creatinine clearance as predictor of tobramycin elimination in adult patients with cystic fibrosis

Assessment of renal function and relating this parameter to amino-glycoside clearance is important for an appropriate individualization of dosage regimens in patients with impaired renal function. However, it has been suggested that in cystic fibrosis (CF), creatinine clearance (CrCl) is not a good predictor of tobramycin clearance because of a lack of correlation. The aim of this study was to investigate the correlation between the tobramycin clearance and the measured CrCl. In addition, because most pharmacokinetic computer models use an a priori relationship between CrCl and tobramycin elimination rate constant [k(el)], regression analysis of k(el) on CrCl was performed. Eighteen CF patients (12 men, 6 women, ages 21-55 years) were treated with intravenous tobramycin. Blood and urine samples were collected for tobramycin analysis and determination of the CrCl. For each patient, CrCl was also estimated using the formulas of Cockcroft and Gault (C/G), Jelliffe I (J I), and Jelliffe II (J II). Predictive performance of these formulas was evaluated using mean error and mean squared error as reflections of bias and precision. Tobramycin total body clearance as well as renal clearance correlated significantly with CrCl (r = 0.52; p = 0.02 and r = 0.78; p = 0.02, respectively). Regression of the tobramycin k(el) versus CrCl gave the following equation: k(el) = 0.135 + 0.00134*CrCl/1.73 m2 (r = 0.64; p = 0.004). The 95% confidence interval of intercept and slope of the regression line were 0.019-0.251 and 0.00049-0.00219, respectively. The formulas of C/G, J I, and J II all overpredicted CrCl. Bias was 19, 24, and 8 ml/min, and precision was 37, 42, and 33 ml/min, respectively, for the C/G, J I, and J II formulas. In our CF population the J II formula gave the best estimation of the CrCl but calculated estimates deviated -25(-)+62% from measured values.

In vitro dissolution profiles of enteric-coated microsphere/microtablet pancreatin preparations at different pH values

OBJECTIVES

Enteric-coated microsphere/microtablet pancreatin should stay intact in the stomach and dissolve promptly on entering the duodenum. Postprandial intraluminal pH in the distal duodenum is 5.75 and is lower in exocrine pancreatic insufficiency. The aim of the study was to measure in vitro dissolution times in buffer solutions with pH 4.0-6.0 for five currently available enteric-coated microsphere/microtablet pancreatin preparations.

METHODS

The following preparations were tested: Creon, Creon Forte, Pancrease, Pancrease HL and Panzytrat. Two capsules were placed in the buffer solution at 37 degrees C in a USP dissolution testing apparatus. Buffer solutions with pH between 4.0 and 6.0 were used. Solutions were stirred at 125 r.p.m. and the rate of dissolution was monitored by taking 2-mL samples at regular intervals and measuring extinction at 280 nm. Measurements were repeated six times.

RESULTS

All preparations failed to dissolve at pH 4.0. At pH 5.0 Pancrease HL showed 43% dissolution within 30 min, all other preparations 15% or less. Panzytrat and Pancrease HL showed more than 50% dissolution within 30 min at pH 5.2. Panzytrat, Pancrease HL and Creon Forte had more than 90% dissolution within 30 min at pH 5.6, and all preparations more than 90% dissolution within 30 min at pH 5.8 and higher.

CONCLUSIONS

For the treatment of exocrine pancreatic insufficiency conventional strength enteric-coated microsphere/microtablet pancreatin preparations do not have an optimal dissolution profile. The newer, high lipase preparations such as Pancrease HL perform better, although still not optimally, at pH 5.4 and lower.

Population pharmacokinetics of ceftazidime in cystic fibrosis patients analyzed by using a nonparametric algorithm and optimal sampling strategy

Postinfusion data obtained from 17 patients with cystic fibrosis participating in two clinical trials were used to develop population models for ceftazidime pharmacokinetics during continuous infusion. Determinant (D)-optimal sampling strategy (OSS) was used to evaluate the benefits of merging four maximally informative sampling times with population modeling. Full and sparse D-optimal sampling data sets were analyzed with the nonparametric expectation maximization (NPEM) algorithm and compared with the model obtained by the traditional standard two-stage approach. Individual pharmacokinetic parameter estimates were calculated by weighted nonlinear least-squares regression and by maximum a posteriori probability Bayesian estimator. Individual parameter estimates obtained with four D-optimally timed serum samples (OSS4) showed excellent correlation with parameter estimates obtained by using full data sets. The parameters of interest, clearance and volume of distribution, showed excellent agreement (R2 = 0.89 and R2 = 0.86). The ceftazidime population models were described as two-compartment kslope models, relating elimination constants to renal function. The NPEM-OSS4 model was described by the equations kel = 0.06516+ (0.00708.CLCR) and V1 = 0.1773 +/- 0.0406 liter/kg where CLCR is creatinine clearance in milliliters per minute per 1.73 m2, V1 is the volume of distribution of the central compartment, and kel is the elimination rate constant. Predictive performance evaluation for 31 patients with data which were not part of the model data sets showed that the NPEM-ALL model performed best, with significantly better precision than that of the standard two-stage model (P < 0.001). Predictions with the NPEM-OSS4 model were as precise as those with the NPEM-ALL model but slightly biased (-2.2 mg/liter; P < 0.01). D-optimal monitoring strategies coupled with population modeling results in useful and cost-effective population models and will be of advantage in clinical practice, as it allows pharmacokinetic-pharmacodynamic modeling with sparse data, thus describing the relationship between ceftazidime exposure and response in the treatment of acute exacerbations in patients with cystic fibrosis.

Stability of aztreonam in a portable pump reservoir used for home intravenous antibiotic treatment (HIVAT)

The stability of the monocyclic beta-lactam antibiotic aztreonam in portable pump reservoirs was studied during storage at temperatures of -20 degrees C and +5 degrees C and during drug delivery at 37 degrees C. Three 100-ml drug reservoirs and three glass containers containing 60 mg/ml aztreonam were stored at -20 degrees C and 2-ml samples were analysed in the freshly prepared solution and after thawing at days 7, 21, 28, 70 and after 6 months of storage. A separate triplicate batch of 100-ml prefilled drug reservoirs and glass containers containing a similar aztreonam concentration (60 mg/ml) were refrigerated and tested immediately after preparation and daily for 8 days and after 70 days. Solutions of aztreonam in duplicate freshly prepared reservoirs were tested for stability when the solution was pumped at 37 degrees C over a 24-h period. All solutions were inspected for visual changes and tested for pH. Drug concentration was analysed by high-performance liquid chromatography. No colour changes or pH differences were observed in any of the solutions in the reservoirs of containers. No statistically significant decrease in aztreonam concentration could be detected after 6 months of storage at -20 degrees C. Aztreonam was stable at 5 degrees C for at least 8 days. A 24-h pumping period at 37 degrees C showed a 3.6% decrease in aztreonam concentration. Aztreonam at a concentration of 60 mg/ml in a pump reservoir is sufficiently stable to be used in home intravenous antibiotic treatment programmes.

Prospective evaluation of a dose prediction algorithm for intravenous tobramycin in adolescent and adult patients with cystic fibrosis

The predictive performance of a new algorithm to calculate the initial daily dose of tobramycin in patients with cystic fibrosis (CF) was prospectively evaluated. Twenty-six patients with CF (15 men, 11 women, 18-45 years of age) with an acute exacerbation of their chronic pulmonary infection were treated with intravenous tobramycin. The initial dose was calculated with a previously presented algorithm. This algorithm was derived from correlation analysis performed on the adjusted daily dose guided by the determination of serum concentrations: dose (mg three times daily) = 90 + 2.13 x LBM (kg), where LBM (male) = (1.1 x body weight [BW]) - (128 x BW2/height2) and LBM (female) = (1.07 x BW) - (148 x BW2/height2). The predictive performance of this algorithm was evaluated comparing the calculated initial daily dose with the adjusted daily dose for peak and trough levels of 9-11 mg/L and 1.0 mg/L, respectively. Mean squared error and mean error were determined as reflections of precision and bias. The predictive performance of the algorithm was compared with historical data on the predictive performance of the standard equation to dose of 3.3 mg/kg body weight three times daily. The dose calculated with the algorithm proved to give peak serum concentrations in a narrower range and to have a greater precision, but bias was equal. Applying the algorithm, more patients had initial peak serum concentrations in the pre-determined range of 9-11 mg/L than when using the standard equation, so fewer dose adjustments had to be made.

Cost of care of patients with cystic fibrosis in The Netherlands in 1990-1

BACKGROUND

Research on the cost of care of patients with cystic fibrosis is scarce. The aim of this study was to estimate the costs using age-specific medical consumption from real patient data.

METHODS

The age-specific medical consumption of patients with cystic fibrosis in The Netherlands in 1991 was estimated from a survey of medical records and a patient questionnaire. A distinction was made between costs of hospital care, hospital and non-hospital medication, and home care. Costs per year were obtained by multiplying the yearly amount of care and the costs per unit.

RESULTS

On average the annual cost of a patient with cystic fibrosis in 1991 was 10,908 pounds (hospital care 42%, medication 37%, home care 20%). The cost of care of cystic fibrosis in The Netherlands, with approximately 1000 patients, is estimated at 10.9 million pounds per year, which is 0.07% of the total health care budget. The cost of care of a patient up to the age of 35 is estimated at 614,587 pounds. When year-to-year survival is taken into account and future costs are discounted to the year of birth with a yearly discount rate of 5%, the cost of care of a patient with cystic fibrosis is estimated at 164,365 pounds for 1991. This estimate will be used in a prospective evaluation of screening for cystic fibrosis carriers.

CONCLUSIONS

The cost of care of patients with cystic fibrosis estimated by age-specific medical consumption of real patients is higher than that estimated by non-age-specific medical consumption and/or expert opinions.

Genetic and clinical features of patients with cystic fibrosis diagnosed after the age of 16 years

BACKGROUND

Cystic fibrosis is usually diagnosed in childhood, but a number of patients are not diagnosed until adulthood. The aim of this study was to investigate whether patients diagnosed at an older age had a different genetic constitution, manifestations of disease, and prognosis from those diagnosed at an early age.

METHODS

Clinical data and results of lung function tests and DNA analysis of 143 adult patients with cystic fibrosis were entered into a computerised database. Patients diagnosed before their 16th birthday (early diagnosis, ED) were compared with those diagnosed at 16 years of age or older (late diagnosis, LD).

RESULTS

Mean age of diagnosis of the ED group was 4.6 years compared with 27.7 years for the LD group. Mean (SD) percentage predicted pulmonary function was better for the LD group than for the ED group: forced expiratory volume in one second (FEV1) 72.5 (31.1)% and 52.0 (24.8)%, and forced vital capacity (FVC) 89.8 (25.7)% and 71.9 (23.0)%, respectively. Colonisation with Pseudomonas aeruginosa was present in 70% of the ED group and 24% of the LD group. In the ED group 81% had pancreatic insufficiency compared with only 12% of the LD group. None of the LD group was homozygous for delta F508 compared with 58% of the ED group. In the LD group 72% were compound AF508 heterozygotes and 28% had two non-delta F508 mutations.

CONCLUSIONS

Among this group of 143 adult patients with cystic fibrosis late diagnosis is caused mainly by delayed expression and mild progression of clinical symptoms. Late diagnosis is associated with milder pulmonary disease, less pancreatic insufficiency, and different cystic fibrosis mutations. Since mortality in cystic fibrosis depends on the progression of pulmonary disease, patients with a late diagnosis have a better prognosis than those diagnosed early.

Inhalation of antibiotics in cystic fibrosis

Aerosol administration of antipseudomonal antibiotics is commonly used in cystic fibrosis. However, its contribution to the improvement of lung function, infection and quality of life is not well-established. All articles published from 1965 until the present time concerning the inhalation of antibiotics in cystic fibrosis were collected by computerized literature search and analysed. Effective aerosol delivery is compromised by nebulizers with limited capacity to produce particles in the respirable range. Twelve studies concerning maintenance treatment were published. Four uncontrolled studies evaluating antibiotic aerosol maintenance treatment in stable patients indicated a beneficial effect in terms of reducing the number of hospital admissions. Eight placebo-controlled studies were found; six of these showed a significant improvement of lung function in the treatment group. Four studies showed a reduction of the number of hospital admissions. In some studies, there was a considerable negative effect of the nebulized placebo solution on the outcome, probably due to the improper choice of its osmolarity. Studies with antibiotic aerosols as adjunct to intravenous therapy in cystic fibrosis patients with an acute exacerbation showed no enhancement of the clinical effects of the intravenous antibiotic by the aerosol; sputum colony counts, however, were lower. Toxicity studies carried out so far have shown no renal or ototoxicity; however, long-term toxicity studies still have to be performed using higher dosages. Introduction or selection of resistant bacteria is relatively rare, but remains a matter of concern. Aerosol maintenance treatment with an appropriate antibiotic in high enough dosage can be recommended for patients with cystic fibrosis chronically infected with P. aeruginosa, and may improve lung function and reduce the number of hospital admissions due to an acute exacerbation.

Inhalation of antibiotics in cystic fibrosis

Aerosol administration of antipseudomonal antibiotics is commonly used in cystic fibrosis. However, its contribution to the improvement of lung function, infection and quality of life is not well-established. All articles published from 1965 until the present time concerning the inhalation of antibiotics in cystic fibrosis were collected by computerized literature search and analysed. Effective aerosol delivery is compromised by nebulizers with limited capacity to produce particles in the respirable range. Twelve studies concerning maintenance treatment were published. Four uncontrolled studies evaluating antibiotic aerosol maintenance treatment in stable patients indicated a beneficial effect in terms of reducing the number of hospital admissions. Eight placebo-controlled studies were found; six of these showed a significant improvement of lung function in the treatment group. Four studies showed a reduction of the number of hospital admissions. In some studies, there was a considerable negative effect of the nebulized placebo solution on the outcome, probably due to the improper choice of its osmolarity. Studies with antibiotic aerosols as adjunct to intravenous therapy in cystic fibrosis patients with an acute exacerbation showed no enhancement of the clinical effects of the intravenous antibiotic by the aerosol; sputum colony counts, however, were lower. Toxicity studies carried out so far have shown no renal or ototoxicity; however, long-term toxicity studies still have to be performed using higher dosages. Introduction or selection of resistant bacteria is relatively rare, but remains a matter of concern. Aerosol maintenance treatment with an appropriate antibiotic in high enough dosage can be recommended for patients with cystic fibrosis chronically infected with P. aeruginosa, and may improve lung function and reduce the number of hospital admissions due to an acute exacerbation.

A cystic fibrosis mutation associated with mild lung disease

BACKGROUND

Cystic fibrosis is the most common lethal autosomal recessive disorder among whites. Among Dutch patients with cystic fibrosis, delta F508 is the most common mutation and A455E the second most common mutation of the cystic fibrosis transmembrane conductance regulator gene on chromosome 7. A455E is associated with preserved pancreatic function and residual secretion of chloride across membranes. We investigated whether it is also associated with less severe pulmonary disease in patients with cystic fibrosis.

METHODS

A total of 33 patients with compound heterozygosity for the A455E mutation were matched according to age and sex with patients who were homozygous for the delta F508 mutation. The pairs were analyzed with respect to the following outcome variables: age at diagnosis, pulmonary-function values, and the frequency of pseudomonas colonization, pancreatic sufficiency, and diabetes mellitus.

RESULTS

Cystic fibrosis was diagnosed at a later age in the patients with the A455E mutation than in the delta F508 homozygotes (mean age at diagnosis, 15.0 vs. 3.1 years; P < 0.001). Fewer patients with the A455E mutation had pancreatic insufficiency (21.2 percent vs. 93.9 percent, P < 0.001), and none had diabetes mellitus (0 percent vs. 27.3 percent, P = 0.004). Forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) were significantly higher in the patients with the A455E mutation (mean FEV1, 73.9 percent of the predicted value vs. 54.3 percent of the predicted value; P = 0.002; mean FVC, 88.7 percent of the predicted value vs. 76.3 percent of the predicted value; P = 0.04). Fewer patients with the A455E mutation were colonized with Pseudomonas aeruginosa (33.3 percent vs. 60.6 percent, P = 0.02).

CONCLUSIONS

A455E is a common mutation causing cystic fibrosis in the Netherlands. Although several mutations are known to be associated with less severe pancreatic disease, our findings demonstrate a correlation between the A455E mutation and mild pulmonary disease. Because mortality in this disease depends primarily on the progression of pulmonary disease, patients with the A455E mutation have a better prognosis than patients who are homozygous for the delta F508 mutation.

Effect of rhDNase on lung function and quality of life in adult cystic fibrosis patients

Accumulation of viscous sputum enhances lung damage in patients with cystic fibrosis. High contents of DNA, released by leucocytes, are the major cause of the high viscosity of this sputum. Recombinant human DNase I (rhDNase) decreases viscoelastic properties of sputum in cystic fibrosis and improves lung function. We have investigated the effect of rhDNase over a period of 6 weeks, 2.5 mg once daily, on lung function and quality of life in 12 adult patients with cystic fibrosis. Significant improvements in FEV1, IVC and daily peak flow values were measured. Airway resistance and FVC did not improve significantly. The cause of the improvements found is probably due to recruitment of previously, due to mucus plugging, unventilated lung areas. In addition, the awareness of symptoms related to sputum retention improved, although subjective parameters on general well-being and physical condition remained unchanged.

Erroneous diagnosis of distal intestinal obstruction syndrome in cystic fibrosis: clinical impact of abdominal ultrasonography

OBJECTIVE

To describe the use of abdominal ultrasonography in the differential diagnosis of distal intestinal obstruction syndrome (DIOS).

DESIGN

Four case reports.

SETTING

Adult cystic fibrosis centre (140 patients).

PATIENTS

Four cystic fibrosis patients presenting over 18 months with clinical symptoms suggestive of a DIOS which could not be substantiated.

OUTCOME

In all cases abdominal ultrasound was valuable in making a diagnosis.

CONCLUSION

Abdominal ultrasound is a useful diagnostic tool for differentiating a DIOS from other abdominal conditions.