Association of intraplacental oxygenation patterns on dual-contrast MRI with placental abnormality and fetal brain oxygenation

OBJECTIVES

Most human in-vivo placental imaging techniques are unable to distinguish and characterize various placental compartments, such as the intervillous space (IVS), placental vessels (PV) and placental tissue (PT), limiting their specificity. We describe a method that employs T2* and diffusion-weighted magnetic resonance imaging (MRI) data to differentiate automatically placental compartments, quantify their oxygenation properties and identify placental lesions (PL) in vivo. We also investigate the association between placental oxygenation patterns and fetal brain oxygenation.

METHODS

This was a prospective study conducted between 2018 and 2021 in which dual-contrast clinical MRI data (T2* and diffusion-weighted MRI) were acquired from patients between 20 and 38 weeks' gestation. We trained a fuzzy clustering method to analyze T2* and diffusion-weighted MRI data and assign placental voxels to one of four clusters, based on their distinct imaging domain features. The new method divided automatically the placenta into IVS, PV, PT and PL compartments and characterized their oxygenation changes throughout pregnancy.

RESULTS

A total of 27 patients were recruited, of whom five developed pregnancy complications. Total placental oxygenation level and T2* did not demonstrate a statistically significant temporal correlation with gestational age (GA) (R²  = 0.060, P = 0.27). In contrast, the oxygenation level reflected by T2* values in the placental IVS (R²  = 0.51, P = 0.0002) and PV (R²  = 0.76, P = 1.1 × 10^-7 ) decreased significantly with advancing GA. Oxygenation levels in the PT did not show any temporal change during pregnancy (R²  = 0.00044, P = 0.93). A strong spatial-dependent correlation between PV oxygenation level and GA was observed. The strongest negative correlation between PV oxygenation and GA (R²  = 0.73, P = 4.5 × 10^-7 ) was found at the fetal-vessel-dominated region close to the chorionic plate. The location and extent of the placental abnormality were automatically delineated and quantified in the five women with clinically confirmed placental pathology. Compared to the averaged total placental oxygenation, placental IVS oxygenation level best reflected fetal brain oxygenation level during fetal development.

CONCLUSION

Based on clinically feasible dual-MRI, our method enables accurate spatiotemporal quantification of placental compartment and fetal brain oxygenation across different GAs. This information should improve our knowledge of human placenta development and its relationship with normal and abnormal pregnancy. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Mercaptopurine versus placebo to prevent recurrence of Crohn's disease after surgical resection (TOPPIC): a multicentre, double-blind, randomised controlled trial

BACKGROUND

Up to 60% of patients with Crohn's disease need intestinal resection within the first 10 years of diagnosis, and postoperative recurrence is common. We investigated whether mercaptopurine can prevent or delay postoperative clinical recurrence of Crohn's disease.

METHODS

We did a randomised, placebo-controlled, double-blind trial at 29 UK secondary and tertiary hospitals of patients (aged >16 years in Scotland or >18 years in England and Wales) who had a confirmed diagnosis of Crohn's disease and had undergone intestinal resection. Patients were randomly assigned (1:1) by a computer-generated web-based randomisation system to oral daily mercaptopurine at a dose of 1 mg/kg bodyweight rounded to the nearest 25 mg or placebo; patients with low thiopurine methyltransferase activity received half the normal dose. Patients and their carers and physicians were masked to the treatment allocation. Patients were followed up for 3 years. The primary endpoint was clinical recurrence of Crohn's disease (Crohn's Disease Activity Index >150 plus 100-point increase in score) and the need for anti-inflammatory rescue treatment or primary surgical intervention. Primary and safety analyses were by intention to treat. Subgroup analyses by smoking status, previous thiopurines, previous infliximab or methotrexate, previous surgery, duration of disease, or age at diagnosis were also done. This trial is registered with the International Standard Randomised Controlled Trial Register (ISRCTN89489788) and the European Clinical Trials Database (EudraCT number 2006-005800-15).

FINDINGS

Between June 6, 2008, and April 23, 2012, 240 patients with Crohn's disease were randomly assigned: 128 to mercaptopurine and 112 to placebo. All patients received at least one dose of study drug, and no randomly assigned patients were excluded from the analysis. 16 (13%) of patients in the mercaptopurine group versus 26 (23%) patients in the placebo group had a clinical recurrence of Crohn's disease and needed anti-inflammatory rescue treatment or primary surgical intervention (adjusted hazard ratio [HR] 0·54, 95% CI 0·27-1·06; p=0·07; unadjusted HR 0·53, 95% CI 0·28-0·99; p=0·046). In a subgroup analysis, three (10%) of 29 smokers in the mercaptopurine group and 12 (46%) of 26 in the placebo group had a clinical recurrence that needed treatment (HR 0·13, 95% CI 0·04-0·46), compared with 13 (13%) of 99 non-smokers in the mercaptopurine group and 14 (16%) of 86 in the placebo group (0·90, 0·42-1·94; pinteraction=0·018). The effect of mercaptopurine did not significantly differ from placebo for any of the other planned subgroup analyses (previous thiopurines, previous infliximab or methotrexate, previous surgery, duration of disease, or age at diagnosis). The incidence and types of adverse events were similar in the mercaptopurine and placebo groups. One patient on placebo died of ischaemic heart disease. Adverse events caused discontinuation of treatment in 39 (30%) of 128 patients in the mercaptopurine group versus 41 (37%) of 112 in the placebo group.

INTERPRETATION

Mercaptopurine is effective in preventing postoperative clinical recurrence of Crohn's disease, but only in patients who are smokers. Thus, in smokers, thiopurine treatment seems to be justified in the postoperative period, although smoking cessation should be strongly encouraged given that smoking increases the risk of recurrence.

FUNDING

Medical Research Council.

Multicentre comparison of the Glasgow Blatchford and Rockall Scores in the prediction of clinical end-points after upper gastrointestinal haemorrhage

BACKGROUND

The Glasgow Blatchford Score (GBS) is increasingly being used to predict intervention and outcome following upper gastrointestinal haemorrhage (UGIH).

AIM

To compare the GBS with both the admission and full Rockall scores in predicting specific clinical end-points following UGIH.

PATIENTS AND METHODS

Data on consecutive patients presenting to four UK hospitals were collected. Admission history, clinical and laboratory data, endoscopic findings, treatment and clinical follow-up were recorded. Using ROC curves, we compared the three scores in the prediction of death, endoscopic or surgical intervention and transfusion. Results  A total of 1555 patients (mean age 56.7years) presented with UGIH during the study period. Seventy-four (4.8%) died, 223 (14.3%) had endoscopic or surgical intervention and 363 (23.3%) required transfusion. The GBS was similar at predicting death compared with both the admission Rockall (area under ROC curve 0.804 vs. 0.801) and full Rockall score (AUROC 0.741 vs. 0.790). In predicting endo-surgical intervention, the GBS was superior to the admission Rockall (AUROC 0.858 vs. 0.705; P<0.00005) and similar to the full Rockall score (AUROC 0.822 vs. 0.797). The GBS was superior to both admission Rockall (AUROC 0.944 vs. 0.756; P<0.00005) and full Rockall scores (AUROC 0.935 vs. 0.792; P<0.00005) in predicting need for transfusion.

CONCLUSIONS

Despite not incorporating age, the GBS is as effective as the admission and full Rockall scores in predicting death after UGIH. It is superior to both the admission and full Rockall scores in predicting need for transfusion, and superior to the admission Rockall score in predicting endoscopic or surgical intervention.

An unusual infection in an injecting drug user

Injecting drug users are prone to atypical infections. We present a case of septic thrombophlebitis secondary to Fusobacterium gonidiaformans infection in a heroin user, which demonstrates the frequently unusual nature of pathogens and presentations in this group of patients.

Efficacy and complications of adalimumab treatment for medically-refractory Crohn's disease: analysis of nationwide experience in Scotland (2004-2008)

BACKGROUND

Adalimumab is a second generation humanized anti-tumour necrosis factor (TNF) monoclonal antibody with established efficacy in Crohn's disease (CD).

AIMS

To evaluate the efficacy and safety of adalimumab on a nationwide clinical setting.

METHODS

We used the Scottish Society of Gastroenterology network to identify and follow up the clinical outcomes of patients with CD treated with adalimumab over a 4-year period (2004-2008).

RESULTS

A total of 98 patients received adalimumab - 100.5 patient follow-up years were recorded (64.3% females; median age at diagnosis of 20.7 years; 88.8% treated with 80/40 mg induction regimen. Eighty eight (89.8%) had previous infliximab with 29 (32.9%) primary nonresponders; 32 (32.6%) were corticosteroid-dependent; 47 (47.9%) were intolerant/resistant to most immunosuppressive therapies (two or more). In all, 60% of patients were in clinical remission at 1-year follow-up, with 30% and 55% requiring dose escalation to weekly therapy at 1-and 2-year follow-up respectively. Overall, 29 (29.6%) patients developed complications with eight nonfatal serious (8.2%) adverse events and 2 (2.0%) case fatalities (sepsis following perforation and disseminated colorectal cancer, respectively).

CONCLUSIONS

Adalimumab is efficacious in severe and refractory CD in the clinical setting, although there remain significant therapy- and disease-related risks of serious complications.

Efficacy and complications of adalimumab treatment for medically-refractory Crohn's disease: analysis of nationwide experience in Scotland (2004-2008)

BACKGROUND

Adalimumab is a second generation humanized anti-tumour necrosis factor (TNF) monoclonal antibody with established efficacy in Crohn's disease (CD).

AIMS

To evaluate the efficacy and safety of adalimumab on a nationwide clinical setting.

METHODS

We used the Scottish Society of Gastroenterology network to identify and follow up the clinical outcomes of patients with CD treated with adalimumab over a 4-year period (2004-2008).

RESULTS

A total of 98 patients received adalimumab - 100.5 patient follow-up years were recorded (64.3% females; median age at diagnosis of 20.7 years; 88.8% treated with 80/40 mg induction regimen. Eighty eight (89.8%) had previous infliximab with 29 (32.9%) primary nonresponders; 32 (32.6%) were corticosteroid-dependent; 47 (47.9%) were intolerant/resistant to most immunosuppressive therapies (two or more). In all, 60% of patients were in clinical remission at 1-year follow-up, with 30% and 55% requiring dose escalation to weekly therapy at 1-and 2-year follow-up respectively. Overall, 29 (29.6%) patients developed complications with eight nonfatal serious (8.2%) adverse events and 2 (2.0%) case fatalities (sepsis following perforation and disseminated colorectal cancer, respectively).

CONCLUSIONS

Adalimumab is efficacious in severe and refractory CD in the clinical setting, although there remain significant therapy- and disease-related risks of serious complications.

Outpatient management of patients with low-risk upper-gastrointestinal haemorrhage: multicentre validation and prospective evaluation

BACKGROUND

Upper-gastrointestinal haemorrhage is a frequent reason for hospital admission. Although most risk scoring systems for this disorder incorporate endoscopic findings, the Glasgow-Blatchford bleeding score (GBS) is based on simple clinical and laboratory variables; a score of 0 identifies low-risk patients who might be suitable for outpatient management. We aimed to evaluate the GBS then assess the effect of a protocol based on this score for non-admission of low-risk individuals.

METHODS

Our study was undertaken at four hospitals in the UK. We calculated GBS and admission (pre-endoscopy) and full (post-endoscopy) Rockall scores for consecutive patients presenting with upper-gastrointestinal haemorrhage. With receiver-operating characteristic (ROC) curves, we compared the ability of these scores to predict either need for clinical intervention or death. We then prospectively assessed at two hospitals the introduction of GBS scoring to avoid admission of low-risk patients.

FINDINGS

Of 676 people presenting with upper-gastrointestinal haemorrhage, we identified 105 (16%) who scored 0 on the GBS. For prediction of need for intervention or death, GBS (area under ROC curve 0.90 [95% CI 0.88-0.93]) was superior to full Rockall score (0.81 [0.77-0.84]), which in turn was better than the admission Rockall score (0.70 [0.65-0.75]). When introduced into clinical practice, 123 patients (22%) with upper-gastrointestinal haemorrhage were classified as low risk, of whom 84 (68%) were managed as outpatients without adverse events. The proportion of individuals with this condition admitted to hospital also fell (96% to 71%, p<0.00001).

INTERPRETATION

The GBS identifies many patients presenting to general hospitals with upper-gastrointestinal haemorrhage who can be managed safely as outpatients. This score reduces admissions for this condition, allowing more appropriate use of in-patient resources.

Effects of chronic ethanol feeding on the protein composition of mitochondrial ribosomes

Chronic ethanol feeding has been shown to decrease the number of functionally active mitochondrial ribosomes by 55%. In this work, 55S mitochondrial ribosomes were isolated from rat liver and their constitutive proteins characterized by two-dimensional polyacrylamide gel electrophoresis and quantified by densitometry. A total of 86 proteins were found to be associated with the mitochondrial ribosome. This compares with 70 isolated from cytoplasmic ribosomes. In addition, mitochondrial ribosomal proteins were found to be significantly less basic than their cytoplasmic counterparts. Chronic ethanol feeding was found to significantly decrease the levels of a number of constitutive proteins of the mitochondrial ribosome when compared to those isolated from pair-fed controls. Sucrose density gradient analyses revealed a significant decrease in the number of intact 55S ribosomes. It is suggested that ethanol-elicited alterations in specific constitutive proteins of the mitochondrial ribosome may lead to impaired assembly of the monosome and that this may result in lower levels of those displaying functional activity.

Effects of chronic ethanol feeding on the protein composition of mitochondrial ribosomes

Chronic ethanol feeding has been shown to decrease the number of functionally active mitochondrial ribosomes by 55%. In this work, 55S mitochondrial ribosomes were isolated from rat liver and their constitutive proteins characterized by two-dimensional polyacrylamide gel electrophoresis and quantified by densitometry. A total of 86 proteins were found to be associated with the mitochondrial ribosome. This compares with 70 isolated from cytoplasmic ribosomes. In addition, mitochondrial ribosomal proteins were found to be significantly less basic than their cytoplasmic counterparts. Chronic ethanol feeding was found to significantly decrease the levels of a number of constitutive proteins of the mitochondrial ribosome when compared to those isolated from pair-fed controls. Sucrose density gradient analyses revealed a significant decrease in the number of intact 55S ribosomes. It is suggested that ethanol-elicited alterations in specific constitutive proteins of the mitochondrial ribosome may lead to impaired assembly of the monosome and that this may result in lower levels of those displaying functional activity.

Perfusion method for thoracoabdominal aneurysm repair using the open distal technique

Challenges related to perfusion support of thoracoabdominal aneurysm repair include maintenance of distal aortic perfusion, rapidity of fluid resuscitation, and avoidance of both hypothermia and excessive hemodilution. Using available technology, we have devised a circuit and protocol that addresses these issues. To accomplish such support a bypass circuit consisting of 3/8 inch tubing connected to a centrifugal pump and low-prime heat exchanger was constructed. The circuit was primed via 1/4 inch spiked connectors attached to a 3-liter bag of normal saline. After initial de-airing, the solution was recirculated through this bag. Patients were anticoagulated with 1 mg/kg of heparin prior to initiation of support. Left atrial-descending aorta bypass was used primarily. A cell salvage device was used for autotransfusion. All blood products were delivered via a rapid infusion device. During partial exsanguination, shed blood was not processed, but directed to the rapid infusor for immediate retransfusion. Any packed cells given were washed prior to transfusion. Citrate dextrose solution was used as an anticoagulant for the cell scavenger. This configuration was used successfully in 50 procedures during an 18-month period. Use of this low-prime, custom circuit reduced both hemodilution and cost. A connection off the cell salvage pump offers fast retransfusion of shed blood during partial exsanguination. Minimal heparinization and citrate anticoagulation appears to reduce coagulopathy.

Still hungry in hospital: identifying malnutrition in acute hospital admissions

We assessed the prevalence, methods for recognition and clinical management of malnutrition in acute admissions in a large academic inner-city hospital. Of a total of 337 patients, it was possible to measure both height and weight in 219 patients (65% of admissions). As an alternative for bed-bound patients, mid-upper arm circumference was not very reliable in predicting BMI (sensitivity 98%; specificity 65%), and waist circumference even less so. Of these, 13% were malnourished (body mass index BMI <18.5 kg/m(2) or BMI 18.5-20 kg/m(2) with reported weight loss >3 kg in the last 3 months). Six patients (31% of those with BMI <18.5 kg/m(2)) and one with BMI 18.5-20 kg/m(2) were recognized as suffering from malnutrition and referred to the dietitian. Review of case records could not establish if the diagnosis was missed in the remainder, or if a conscious decision was taken not to manage malnutrition actively. Malnutrition in acute hospital admissions goes apparently unrecognized and unmanaged in 70% of cases. Since there are serious consequences, and effective simple treatment is readily available, increased awareness is required, with routine assessment of nutritional status in all patients.

Potentiation by chronic ethanol treatment of the mitochondrial permeability transition

Mitochondria isolated from rats chronically fed ethanol were more sensitive to induction of the mitochondrial permeability transition (MPT) by a variety of agents than mitochondria isolated from isocalorically matched controls. The agents utilized have been implicated in both necrotic (Ca(2+)) and apoptotic (ceramide, GD3 ganglioside, and Bax) forms of cell killing and help promote pore opening by differing mechanisms. In each case it was found that concentrations of the inducing agents which promoted little or no pore opening in mitochondria isolated from pair matched controls produced massive MTP opening in mitochondria from chronically ethanol fed rats as evidenced by swelling. In all cases induction of the MPT was prevented by the presence of cyclosporin A.

Chronic ethanol consumption causes alterations in the structural integrity of mitochondrial DNA in aged rats

Chronic ethanol consumption adversely affects the respiratory activity of rat liver mitochondria. It causes increased cellular production of oxygen radical species and selectively decreases mitochondrial glutathione (GSH) levels. Here we show, using Southern hybridization techniques on total rat genomic DNA, that long-term (11-13 months) ethanol feeding, using the Lieber-DeCarli diet, results in a 36% (P <.05; n = 4) decrease in hepatic mitochondrial DNA (mtDNA) levels when compared with paired controls. UV quantitation of mtDNA isolated from hepatic mitochondria showed that chronic ethanol intake (11-13 months) causes a 44% (P <.01; n = 6) decrease in the amount of mtDNA per milligram of mitochondrial protein. No significant decline in mtDNA levels was seen in ethanol-fed animals maintained on the diet for 1 to 5 months. Ethanol feeding caused a 42% (P <.01; n = 4) and a 132% (P <.05; n = 3) increase in 8-hydroxydeoxyguanosine (8-OHdG) formation in mtDNA in animals maintained on the diet for 3 to 6 months and 10 to 11 months, respectively. In addition, agarose gel electrophoresis revealed a 49% increase (P <.05; n = 3) in mtDNA single-strand breaks (SSB) in animals fed ethanol for more than 1 year. These findings suggest that chronic ethanol consumption causes enhanced oxidative damage to mtDNA in older animals along with increased strand breakage, and that this results in its selective removal/degradation by mtDNA repair enzymes.

Review article: malnutrition and maltreatment--a comment on orlistat for the treatment of obesity

The prevalence of obesity has doubled in the last 10 years and is now reaching epidemic proportions. There is a significant comorbidity and financial cost associated with this disorder. Orlistat is an intestinal lipase inhibitor that is approved for the treatment of obesity. Recent randomized, double-blind, placebo-controlled trials have demonstrated the benefit of orlistat used in conjunction with a hypocaloric (low-fat) diet in facilitating weight reduction and the long-term maintenance of this weight loss. Patients treated with orlistat lost a greater amount of initial body weight compared to those who received placebo. After 24 months of treatment, weight loss of more than 5% was maintained in a greater number of those treated with orlistat. This was associated with significant reductions in cardiovascular risk factors (cholesterol, LDL cholesterol, LDL:HDL cholesterol ratio). The main adverse events are related to fat malabsorption, with potential losses of fat-soluble vitamins and other compounds. Orlistat as a treatment for obesity, when prescribed within present guidelines, can aid modest weight loss in about one-third of patients. More importantly, it can assist in the maintenance of weight loss with major medical benefits for these patients.