Adjunctive technologies in postoperative free-flap monitoring: a systematic review

Patent microvascular anastomoses are essential for successful free tissue transfer. Early accurate detection of microvascular compromise is required for flap salvage. Adjunctive monitoring techniques, in addition to clinical examination, are increasingly used to detect flap compromise. This systematic review synthesized and appraised the literature to determine the efficacy of different postoperative monitoring technologies. Rates of flap takeback, salvage, failure, and mean time to detection of microvascular compromise were extracted, synthesized, and reviewed. Twenty-two studies were included, comprising 6370 flaps. One thousand three hundred and ninety-five flaps were monitored with Cook Swartz Doppler (21.83%), 1417 flaps with tissue oximetry (22.24%), 291 with laser Doppler (4.56%), 175 with duplex echography (2.74%), 210 with indocyanine green (ICG) fluorescence (3.30%), 196 with Synovis flow coupler (3.07%), and 81 (1.27%) with light spectroscopy. The overall true positive rate for microvascular compromise in taken back flaps was 70.18%. Cook Swartz Doppler (n = 1391) had a true positive rate of 80.17% and 83.63% salvage rate and was associated with an overall 2.60% rate of flap failure. Tissue oximetry (n = 1417) had a true positive rate of 74.76% and a salvage rate of 88.62%. Laser Doppler, duplex echography, light spectroscopy, and Synovis flow coupler demonstrated true positive rates between 69.4% and 100% with salvage rates between 64% and 100%. Cook Swartz Doppler and tissue oximetry are associated with prompt identification of microvascular compromise and return to theatre. Alternative modalities, including near-infrared spectroscopy, laser Doppler, and duplex echography, show promise. Further well-designed randomised controlled trials (RCTs) appraising head-to-head efficacy are required to comparatively assess adjunctive technologies.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

A highly virulent variant of HIV-1 circulating in the Netherlands

We discovered a highly virulent variant of subtype-B HIV-1 in the Netherlands. One hundred nine individuals with this variant had a 0.54 to 0.74 log₁₀ increase (i.e., a ~3.5-fold to 5.5-fold increase) in viral load compared with, and exhibited CD4 cell decline twice as fast as, 6604 individuals with other subtype-B strains. Without treatment, advanced HIV-CD4 cell counts below 350 cells per cubic millimeter, with long-term clinical consequences-is expected to be reached, on average, 9 months after diagnosis for individuals in their thirties with this variant. Age, sex, suspected mode of transmission, and place of birth for the aforementioned 109 individuals were typical for HIV-positive people in the Netherlands, which suggests that the increased virulence is attributable to the viral strain. Genetic sequence analysis suggests that this variant arose in the 1990s from de novo mutation, not recombination, with increased transmissibility and an unfamiliar molecular mechanism of virulence.

The methodological strategies of agroecological research and the values with which they are linked

The characteristic features of some of the methodological strategies adopted in scientific research in agroecology are discussed. They reflect that agroecology, as an approach to scientific research, is inextricably entangled with the other strands of agroecology (farming practice, social movement, political project); and that adopting agroecological strategies, and upholding the values of environmental sustainability, food sovereignty, social justice and democratic participation, mutually reinforce each other. After outlining the kinds of questions that agroecological research addresses so that it can produce knowledge that informs agroecological farming practices and the long term aspiration of agroecological movements to create an alternative agricultural/food system, and then making summary remarks about methodological strategies in general, three characteristic features of some agroecological strategies are introduced and discussed. The paper concludes with comments on the value of agroecological research.

'Holding' and 'endorsing' claims in the course of scientific activities

My principal aims are to show that holding, adopting and endorsing (definitions of which I provide) are distinct cognitive attitudes that may be taken towards claims at different moments of scientific activities, and that none of them are reducible to acceptance (as defined by Jonathan Cohen); to explore in detail the differences between holding and accepting, using the controversies about GMOs to provide illustrations; and to draw some implications pertinent to democratic decision-making concerning public policies about science and technology, and to the responsibilities that scientists thereby incur.

Empirical examination of the interpersonal maintenance model of anorexia nervosa

OBJECTIVE

A cognitive interpersonal maintenance model of anorexia nervosa (AN) was first proposed in 2006 and updated in 2013 (Schmidt and Treasure, J Br J Clin Psychol, 45, 343-366, 2006; Treasure and Schmidt, J Eat Disorders, in press.). The aim of this study was to test the interpersonal component of this model in people with AN requiring intensive hospital treatment (inpatient/day patient).

METHOD

On admission to hospital women with AN or eating disorder not otherwise specified (AN subtype; n = 152; P) and their primary carers (n = 152; C) completed questionnaires on eating symptoms (P), depression and anxiety (P, C), accommodation and enabling (C), and psychological control (C). Structural equation modeling was used to examine relationships among these components.

RESULTS

Carers' expressed emotion and level of psychological control were significantly related to carers' distress, which in turn, was related to patients' distress. This pathway significantly predicted eating symptoms in patients.

DISCUSSION

The cognitive interpersonal maintenance model of eating disorders (EDs) was confirmed in part and suggests that interventions targeting interpersonal maintaining factors such as carer distress might impact on patient outcomes.

Treating severe and enduring anorexia nervosa: a randomized controlled trial

BACKGROUND

There are no evidence-based treatments for severe and enduring anorexia nervosa (SE-AN). This study evaluated the relative efficacy of cognitive behavioral therapy (CBT-AN) and specialist supportive clinical management (SSCM) for adults with SE-AN.

METHOD

Sixty-three participants with a diagnosis of AN, who had at least a 7-year illness history, were treated in a multi-site randomized controlled trial (RCT). During 30 out-patient visits spread over 8 months, they received either CBT-AN or SSCM, both modified for SE-AN. Participants were assessed at baseline, end of treatment (EOT), and at 6- and 12-month post-treatment follow-ups. The main outcome measures were quality of life, mood disorder symptoms and social adjustment. Weight, eating disorder (ED) psychopathology, motivation for change and health-care burden were secondary outcomes.

RESULTS

Thirty-one participants were randomized to CBT-AN and 32 to SSCM with a retention rate of 85% achieved at the end of the study. At EOT and follow-up, both groups showed significant improvement. There were no differences between treatment groups at EOT. At the 6-month follow-up, CBT-AN participants had higher scores on the Weissman Social Adjustment Scale (WSAS; p = 0.038) and at 12 months they had lower Eating Disorder Examination (EDE) global scores (p = 0.004) and higher readiness for recovery (p = 0.013) compared to SSCM.

CONCLUSIONS

Patients with SE-AN can make meaningful improvements with both therapies. Both treatments were acceptable and high retention rates at follow-up were achieved. Between-group differences at follow-up were consistent with the nature of the treatments given.

An outbreak of infectious syphilis among young heterosexuals in an English town

We describe a recent outbreak of syphilis in young heterosexuals in the north west of England. A cluster of 12 cases of syphilis (7 primary and 5 early latent) was identified in Rochdale in heterosexuals aged 20 or under. Nine were women. Five were asymptomatic at presentation. This outbreak occurred in a group not usually associated with syphilis transmission in the north west. Not all the identified cases could be linked, and so potentially this outbreak is a sentinel of a larger problem.

Parotid gland enlargement in eating disorders: an insensitive sign?

OBJECTIVE

To study, using magnetic resonance imaging (MRI), the parotid glands of patients who self-induce vomiting and in particular to observe the effects of cessation of this behaviour. The morphological features and composition of enlarged parotid glands in this group, compared with normal controls, were also examined.

METHOD

MRI scans of the parotid glands were performed on 5 controls and 5 subjects with a purging form of eating disorder, at cessation of vomiting and 6 to 9 weeks later.

RESULTS

Parotid volumes are accurately measured using MRI. Enlarged parotids are not a consistent feature of subjects with eating disorders who self-induce vomiting.

CONCLUSION

Absence of salivary gland enlargement does not exclude significant vomiting behaviour and clinicians should remain alert to the possibility of undisclosed vomiting.

The extent and variability of effects of culture conditions on the secretion of human chorionic gonadotrophin and interleukin-6 by human, term placental explants in culture

Culture of explants derived from third trimester human placenta is used in a range of contexts as an experimental model that retains tissue architecture. This study aimed to explore the variability between, and within, individuals of secretion by explants of human chorionic gonadotrophin (hCG) and interleukin-6 (IL-6). Standard culture medium contained hydrocortisone, insulin, retinoic acid and serum. Under these conditions explants displayed significant differences in the time-course and extent of hCG secretion. Peak hCG secretion varied between 1.19 and 242 mIU/mg protein/h (coefficient of variation (CV) = 111%) and could occur between days 4 and 7 of culture. hCG secretion was more variable if explant protein was < 400 microg. Unadjusted day 7 hCG secretion showed marked variation: intra-placental CV = 15%, inter-placental CV = 86%. When day 7 hCG secretion was standardised by day 6 secretion, intra-placental CV was 6.9%, inter-placental CV was 4.0%. When this standardisation was applied, hCG secretion during day 7 of culture was not affected by removal of hydrocortisone, insulin or serum from the medium or by the addition of tumour necrosis factor-alpha (TNF-alpha). The secretion of IL-6 during day 7 of culture (standardised by taking natural logarithms) was increased markedly by the addition of TNF-alpha but unaltered by removing hydrocortisone, insulin or serum. Thus, we have shown that although variable, secretion by placental explants can be used to investigate how placental tissue adapts to different culture conditions. However, explants of the same protein content may have markedly different secretory properties.

Assessing the value of transgenic crops

In the current controversy about the value of transgenic crops, matters open to empirical inquiry are centrally at issue. One such matter is a key premise in a common argument (that I summarize) that transgenic crops should be considered to have universal value. The premise is that there are no alternative forms of agriculture available to enable the production of sufficient food to feed the world. The proponents of agroecology challenge it, claiming that agroecology provides an alternative, and they deny the claim that it is well founded on empirical evidence. It is, therefore, a matter of both social and scientific importance that this premise and the criticisms of it be investigated rigorously and empirically, so that the benefits and disadvantages of transgenic-intensive agriculture and agroecology can be compared in a reliable way. Conducting adequate investigation about the potential contribution of agroecology requires that the cultural conditions of its practice (and, thus, of the practices and movements of small-scale farmers in the "third world") be strengthened--and this puts the interests of investigation into tension with the socio-economic interests driving the development of transgenics. General issues about relationship between ethical argument and empirical (scientific) investigation are raised throughout the article.

Regulation of placental transfer: the Na(+)/H(+) exchanger--a review

This review article considers the purposes and mechanisms of regulation of placental transfer in general terms and then illustrates some key points with reference to the Na(+)/H(+) exchanger (NHE), a transport protein found in the syncytiotrophoblast. NHE probably has a role in the homeostasis of syncytiotrophoblast intracellular pH and may also be involved in syncytiotrophoblast cell volume regulation as well as H(+) loss from and Na(+) transfer to the fetus. The activity and expression of NHE in the microvillous plasma membrane of the syncytiotrophoblast is reduced in placentas from preterm, growth restricted babies as compared to their gestationally matched normally grown counterparts. There are differential effects of gestation in normal pregnancy on NHE mRNA, NHE protein and NHE activity. There is also evidence of acute modulation of NHE activity. Regulation of NHE in syncytiotrophoblast is therefore complex with control at transcription, post transcription and post translational loci.

Tissue interactions in the control of trophoblast invasion

On the basis of observations made in an explant model of anchoring villus development, it is proposed that two discrete types of signal are required to trigger the entry of cytotrophoblast into the migratory extravillous lineage. The first is mediated by contact of the tip of the first trimester mesenchymal villus with decidual extracellular matrix, in response to which stem villous cytotrophoblast undergoes a proliferative burst and differentiates into cells of the cytotrophoblast column, anchoring peripheral villi to the uterus. Column stability is dependent on the interaction between extracellular fibronectin and integrin alpha 5 beta 1 expressed at the cell surface, both of which are upregulated in this pathway. Subsequently, cells detach in large numbers from the periphery of the column and become migratory infiltrative cells. This step is dependent on paracrine signalling from the mesenchymal cells that lie directly beneath the villous basement membrane. As the signal decreases with increasing distance from the placental anchoring villus, this mechanism might account for the fact that trophoblast invasion progresses no deeper than the inner myometrium.

GP referral to an eating disorder service: why the wide variation?

BACKGROUND

Early detection and management of patients with eating disorders is thought to improve prognosis, yet little is known about the factors associated with referral of these patients to treatment centres.

AIM

To calculate general practitioner (GP) referral rates to a specialist eating disorder service and determine the association between referral rate and general practice and practitioner factors.

METHOD

Referral rate was calculated from a database of routine referrals to St George's Hospital Eating Disorder Service from January 1990 to May 1996 and correlated with practice and practitioner details obtained from medical directories and health authority data.

RESULTS

There was a wide variation in referral rates. A higher referral rate was found to be associated with practice size, proximity to the clinic, female GPs, GPs having the MRCGP qualification, being United Kingdom qualified, and offering full contraceptive services. Fundholding was associated with lower rates of referral.

CONCLUSION

Patients with eating disorders may be at a disadvantage in certain practices. Educational interventions could be targeted towards low referrals.

Growth factor-extracellular matrix synergy in the control of trophoblast invasion

At the periphery of the human placenta, trophoblast attaches to the uterine wall. The tissue interface contains many anchoring sites, with cytotrophoblast columns that form bridges between the overlying extraembryonic (villous) mesenchyme and the maternal decidual stroma beneath. From the periphery of these columns, large numbers of trophoblast cells detach, migrate through the decidua and eventually colonize and transform maternal arteries. In this way the placenta increases and gives priority to the maternal blood supply to the conceptus. We have shown that when early villous tissue is explanted on a collagen gel in serum-free medium, anchoring-site morphogenesis occurs. Thus, in the presence of placental mesenchyme but in the absence of maternal cells, contact with a permissive extracellular matrix (ECM) is necessary and sufficient for cytotrophoblast column development. Proliferation of trophoblast occurs, followed by differentiation into a columnar cell phenotype in which cells remain attached to one another and to the ECM. At this stage, interaction between fibronectin and integrin alpha5beta1 at the cell surface stabilizes the column and the cells remain as a contiguous multilayered sheet. However, the addition of serum-free conditioned medium from first-trimester placental fibroblasts stimulates cytotrophoblast to detach from the distal column and migrate in streams across the ECM. The removal of insulin-like growth factor I (IGF-I) from the fibroblast medium decreases streaming activity, whereas the addition of exogenous IGF-I (10 ng/ml) to serum-free medium produces a streaming phenotype. In contrast, transforming growth factor beta1 (10 ng/ml) maintains the cells in a tight sheet. These results suggest the possibility of a paracrine interaction between villous mesenchyme and cytotrophoblast in anchoring sites to stimulate the infiltration of the maternal ECM by trophoblast. Such a mechanism would be self-limiting because the signal diminishes with distance from the placenta.

Phase I trial and pharmacokinetics of the tubulin inhibitor 1069C85--a synthetic agent binding at the colchicine site designed to overcome multidrug resistance

The orally administered tubulin-binding agent 1069C85 was developed with the hope of overcoming the multidrug resistance associated with existing anti-tubulin agents, such as the vinca alkaloids. A phase I study was performed using a single oral dose every 3 weeks, administered as a suspension reconstituted in 0.1% Tween 80 and 0.9% saline. The starting dose was 2.8 mg m-2, and dose doubling was permitted until the area under curve (AUC) was > or = 40% of that at the mouse LD10; thereafter, a modified Fibonacci scheme was used. The formulation proved to be unsatisfactory, resulting in inconsistent absorption. The terminal elimination half-life was prolonged (range 18-73.5 h). Sporadic central neurotoxicity was observed, which was grade 3 in one patient treated at 200 mg m-2. A revised formulation with micronized drug was more easily suspended and appeared to increase the bioavailability by a factor of 2-4. Severe central neurotoxicity, up to grade 4, was then observed at doses of 50-100 mg m-2. Unfortunately, toxicity was not predictable and one patient, with a previous history of partial intestinal obstruction, treated at 50 mg m-2, cleared the drug very slowly, possibly because of prolonged, delayed absorption. This patient died from pancytopenia and severe gastrointestinal damage. It was concluded that such unpredictable behaviour would be incompatible with safe evaluation in phase II studies; the trial was closed and further clinical development abandoned.

Avascular necrosis of the hip in a man with HIV infection

The development of an osteonecrotic (avascular necrosis) hip joint in a patient with symptomatic CDC Stage 1V C2 disease is reported. The diagnosis was aided by radiological assessment and confirmed by radioisotope bone scan. This case serves as yet another musculoskeletal manifestation in association with HIV infection.