The empty pelvis syndrome: a core data set from the PelvEx collaborative

BACKGROUND

Empty pelvis syndrome (EPS) is a significant source of morbidity following pelvic exenteration (PE), but is undefined. EPS outcome reporting and descriptors of radicality of PE are inconsistent; therefore, the best approaches for prevention are unknown. To facilitate future research into EPS, the aim of this study is to define a measurable core outcome set, core descriptor set and written definition for EPS. Consensus on strategies to mitigate EPS was also explored.

METHOD

Three-stage consensus methodology was used: longlisting with systematic review, healthcare professional event, patient engagement, and Delphi-piloting; shortlisting with two rounds of modified Delphi; and a confirmatory stage using a modified nominal group technique. This included a selection of measurement instruments, and iterative generation of a written EPS definition.

RESULTS

One hundred and three and 119 participants took part in the modified Delphi and consensus meetings, respectively. This encompassed international patient and healthcare professional representation with multidisciplinary input. Seventy statements were longlisted, seven core outcomes (bowel obstruction, enteroperineal fistula, chronic perineal sinus, infected pelvic collection, bowel obstruction, morbidity from reconstruction, re-intervention, and quality of life), and four core descriptors (magnitude of surgery, radiotherapy-induced damage, methods of reconstruction, and changes in volume of pelvic dead space) reached consensus-where applicable, measurement of these outcomes and descriptors was defined. A written definition for EPS was agreed.

CONCLUSIONS

EPS is an area of unmet research and clinical need. This study provides an agreed definition and core data set for EPS to facilitate further research.

A challenge to the evidence behind noise guidelines for UK hospitals

BACKGROUND

Teams assessing hospital noise against international guidelines regularly find that noise exceeds perceived safe levels in clinical settings. The care of sick people may be inherently noisy but recent efforts to tackle the problem propose a wider scope to identify sources and qualities of noise as well as more precision with noise recording.

AIMS

We sought to challenge the scientific evidence cited in the four major documents pertaining to hospital noise in the UK to clarify if evidence of harm from noise included in guidelines is available, contemporary and of high quality.

METHODS

Our team of hearing-health clinicians, acoustic scientists and acoustic engineers have conducted a narrative scoping review focused on critically appraising four of the most cited guidelines against which noise is measured in healthcare settings in the UK.

RESULTS

There is a lack of high-quality evidence for commonly accepted consequences of noise cited in current guidelines.

CONCLUSIONS

The current evidence base for noise guidelines in a healthcare setting is largely based on subjective heterogeneous and inconclusive research. Whilst reduced noise is not disputed as potentially beneficial for patient care, further hypothesis-driven research and interventions assessing the benefits or outcomes of any such intervention should be sought to produce high-quality evidence of relevance on the clinical coalface.

Minimum standards of pelvic exenterative practice: PelvEx Collaborative guideline

This document outlines the important aspects of caring for patients who have been diagnosed with advanced pelvic cancer. It is primarily aimed at those who are establishing a service that adequately caters to this patient group. The relevant literature has been summarized and an attempt made to simplify the approach to management of these complex cases.

Complete resection of the iliac vascular system during pelvic exenteration: an evolving surgical approach to lateral compartment excision

Tumour infiltration of the lateral pelvic compartment has previously been associated with the highest rate of involved resection margins and carries significant risk of morbidity. In this study, consecutive patients undergoing pelvic exenteration at a single centre between 1994 and 2019 who required en bloc resection of the common or external iliac artery or vein were included.The results demonstrate that complete resection of the iliac vascular system, including resection and reconstruction of the common and external iliac vessels, can be performed safely during pelvic exenteration with oncological outcomes comparable to more central tumours.

Prone en bloc sacrectomy with proctectomy: a surgical approach to the inaccessible and hostile pelvis

AIM

Reoperative pelvic surgery is rarely hostile and unsafe. Kraske's procedure has historically been used to approach the mid-rectum and to resect retrorectal tumors. However, it provides limited access to the pelvis and is best in the 'virgin' pelvis. We have encountered a select group of patients who required completion proctectomy or resection of a disconnected ileoanal J-pouch where trans-abdominal access to the pelvis was not possible and access to the pelvis could only be safely gained by a prone en bloc sacrectomy.

METHOD

We describe a prone approach that provides an alternative route of access to the hostile pelvis. After exposure of the sacrum and coccyx and transection of the sacrum, access to the mesorectal plane is achieved and a proctectomy (or resection of an ileoanal J-pouch) can be completed. The procedure is similar to the Kraske approach but requires a higher and wider exposure similar to the extent of an abdominal resection; however, the operation is performed in 'reverse'.

RESULTS

We found that this approach was feasible and safe in the previously operated, hostile pelvis. We employed it in one patient to excise a disconnected J-pouch with chronic sepsis and in another patient for a completion proctectomy. Both patients had an uneventful recovery and clear margins were obtained with no complications.

CONCLUSION

The en bloc prone sacrectomy approach is a useful alternative in a very select group of patients with difficult trans-abdominal access to the pelvis. Experience in pelvic surgery and identification of clear anatomical landmarks is paramount to avoid catastrophic uncontrollable bleeding.

Simultaneous pelvic exenteration and liver resection for primary rectal cancer with synchronous liver metastases: results from the PelvEx Collaborative

AIM

At presentation, 15-20% of patients with rectal cancer already have synchronous liver metastases. The aim of this study was to determine the surgical and survival outcomes in patients with advanced rectal cancer who underwent combined pelvic exenteration and liver (oligometastatic) resection.

METHOD

Data from 20 international institutions that performed simultaneous pelvic exenteration and liver resection between 2007 and 2017 were accumulated. Primarily, we examined perioperative outcomes, morbidity and mortality. We also assessed the impact that margin status had on survival.

RESULTS

Of 128 patients, 72 (56.2%) were men with a median age of 60 years [interquartile range (IQR) 15 years]. The median size of the liver oligometastatic deposits was 2 cm (IQR 1.8 cm). The median duration of surgery was 406 min (IQR 240 min), with a median blood loss of 1090 ml (IQR 2010 ml). A negative resection margin (R0 resection) was achieved in 73.5% of pelvic exenterations and 66.4% of liver resections. The 30-day mortality rate was 1.6%, and 32% of patients had a major postoperative complication. The 5-year overall survival for patients in whom an R0 resection of both primary and metastatic disease was achieved was 54.6% compared with 20% for those with an R1/R2 resection (P = 0.006).

CONCLUSION

Simultaneous pelvic exenteration and liver resection is feasible, with acceptable morbidity and mortality. Simultaneous resection should only be performed where an R0 resection of both pelvic and hepatic disease is anticipated.

Prognostic factors and patterns of failure after surgery for T4 rectal cancer in the beyond total mesorectal excision era

BACKGROUND

Despite advances in the rates of total mesorectal excision (TME) for rectal cancer surgery, decreased local recurrence rates and increased 5-year survival, there still exists large variation in the quality of treatment received. Up to 30 per cent of rectal cancers are locally advanced at presentation and approximately 5-10 per cent still breach the mesorectal plane and invade adjacent structures despite neoadjuvant therapy. With the evolution of extended resections for rectal cancers beyond the TME plane, proponents advocate that these resections should be performed only in specialist centres. The aim was to assess the prognostic factors and patterns of failure after beyond TME surgery for T4 rectal cancers.

METHODS

Data were collected from prospective databases at three high-volume institutions specializing in beyond TME surgery for T4 rectal cancers between 1990 and 2013. The primary outcome measures were overall survival, local recurrence and patterns of first failure.

RESULTS

Three hundred and sixty patients were identified. The negative resection margin (R0) rate was 82·8 per cent (298 patients) and the local recurrence rate was 12·5 per cent (45 patients). The type of surgical procedure (Hartmann's: hazard ratio (HR) 4·49, 95 per cent c.i. 1·99 to 10·14; P = 0·002) and lymphovascular invasion (HR 2·02, 1·08 to 3·77; P = 0·032) were independent predictors of local recurrence. The 5-year overall survival rate for all patients was 61 (95 per cent c.i. 55 to 67) per cent. The 5-year cumulative incidence of first failure was 8 per cent for local recurrence, 6 per cent for local and distant disease, and 18 per cent for distant disease.

CONCLUSION

This study has demonstrated that a coordinated approach in specialist centres for beyond TME surgery can offer good oncological and long-term survival in patients with T4 rectal cancers.

A functional macrophage migration inhibitory factor promoter polymorphism is associated with reduced diffusing capacity

Cigarette smoke exposure is the leading modifiable risk factor for chronic obstructive pulmonary disease (COPD); however, the clinical and pathologic consequences of chronic cigarette smoke exposure are variable among smokers. Macrophage migration inhibitory factor (MIF) is a pleiotropic cytokine implicated in the pathogenesis of COPD. Within the promoter of the MIF gene is a functional polymorphism that regulates MIF expression (-794 CATT_5-8 microsatellite repeat) ( rs5844572 ). The role of this polymorphim in mediating disease susceptibility to COPD-related traits remains unknown. We performed a cross-sectional analysis of DNA samples from 641 subjects to analyze MIF-794 CATT_5-8 ( rs5844572 ) polymorphism by standard methods. We generated multivariable logistic regression models to determine the risk of low expressing MIF alleles for airflow obstruction [defined by forced expiratory volume in 1 s (FEV₁)/forced vital capacity ratio <0.70] and an abnormal diffusion capacity [defined by a diffusion capacity for carbon monoxide (DL_CO) percent predicted <80%]. We then used generalized linear models to determine the association of MIF genotypes with FEV₁ percent predicted and DL_CO percent predicted. The MIF-794 CATT₅ allele was associated with an abnormal diffusion capacity in two cohorts [odds ratio (OR): 9.31, 95% confidence interval (CI): 1.97-4.06; and OR: 2.21, 95% CI: 1.03-4.75]. Similarly, the MIF-794 CATT₅ allele was associated with a reduced DL_CO percentage predicted in these two cohorts: 63.5 vs. 70.0 ( P = 0.0023) and 60.1 vs. 65.4 ( P = 0.059). This study suggests an association between a common genetic polymorphism of an endogenous innate immune gene, MIF, with reduced DL_CO, an important measurement of COPD severity.

Survival after pelvic exenteration for T4 rectal cancer

BACKGROUND

The purpose of this study was to analyse retrospectively the pooled results after pelvic exenteration for locally advanced T4 rectal cancer. Historically, patients with T4 rectal cancers requiring pelvic exenteration have been offered only palliative surgery or no operation.

METHODS

The basic treatment principle was preoperative (chemo)radiotherapy, radical surgery and, in some patients, adjuvant chemotherapy. Risk factors for local recurrence, distant metastases and overall survival were studied in univariable and multivariable analyses.

RESULTS

Ninety-five patients with T4 rectal cancer who underwent pelvic exenteration in two tertiary referral centres up to 2013 were studied. Clear margins (R0) were achieved in 87 per cent of patients. Adjuvant chemotherapy was administered in 33 per cent, independent of the resection margin, lymph node status and postoperative T category. The 5-year local recurrence rate was 17 per cent, with a distant metastasis rate of 16 per cent and overall survival rate of 62 per cent. In multivariable analysis the only factor associated with death was omission of adjuvant chemotherapy (P = 0.016). The effect of adjuvant chemotherapy was more pronounced in the elderly: patients aged over 70 years who had chemotherapy had a 5-year overall survival rate of 80 per cent, compared with 39 per cent of elderly patients who did not receive chemotherapy (P = 0.019).

CONCLUSION

Pelvic exenteration led to an R0 resection rate of 87 per cent for T4 rectal cancer, giving good local control and overall survival comparable to population-based colorectal cancer survival rates. Adjuvant chemotherapy may improve overall survival further, even in the elderly.

Pelvic exenteration for recurrent squamous cell carcinoma of the pelvic organs arising from the cloaca--a single institution's experience over 16 years

AIM

Minimal data are available on the role of pelvic exenteration in patients with recurrent squamous cell carcinoma (SCC) of the pelvic organs. This study aimed to highlight our experience of pelvic exenteration in patients with recurrent and re-recurrent SCC of the pelvic organs.

METHOD

A retrospective review of all patients who underwent pelvic exenteration for recurrent SCC of the pelvic organs arising from the embryological cloaca from 1994 to 2010 was performed.

RESULTS

Twenty-four patients (median age 59, range, 27-79 years) underwent pelvic exenteration for recurrent SCC of the anus (18), cervix and upper vagina (2), lower vagina (1) and the vulva (3). Nine patients with anal SCC had undergone abdominoperineal excision prior to pelvic exenteration. Ten (41.7%) patients underwent a complete pelvic exenteration procedure, while sacrectomy was performed in 13 (54.2%) patients. There was no 30-day inpatient mortality. An R0 resection was achieved in 15 (62.5%) patients. Three (12.5%) had R1 resections while 6 (25%) had R2 resections. In the 15 patients with an R0 resection, 7 (46.7%) developed metastatic disease at a median of 18 (range 10-131) months. After a median follow-up of 26 (range 4-169) months, 1- and 2-year overall survival rates were 64% [95% confidence interval (CI), 44-84%] and 57% (95% CI 35-79%), respectively.

CONCLUSION

Pelvic exenteration for recurrent SCC of the cloaca is safe and feasible even after previous salvage surgery. An R0 resection can be achieved in 62.5% of the patients with reasonable early survival though less than published recurrent rectal cancer studies.

Search for gravitational waves associated with γ-ray bursts detected by the interplanetary network

We present the results of a search for gravitational waves associated with 223 γ-ray bursts (GRBs) detected by the InterPlanetary Network (IPN) in 2005-2010 during LIGO's fifth and sixth science runs and Virgo's first, second, and third science runs. The IPN satellites provide accurate times of the bursts and sky localizations that vary significantly from degree scale to hundreds of square degrees. We search for both a well-modeled binary coalescence signal, the favored progenitor model for short GRBs, and for generic, unmodeled gravitational wave bursts. Both searches use the event time and sky localization to improve the gravitational wave search sensitivity as compared to corresponding all-time, all-sky searches. We find no evidence of a gravitational wave signal associated with any of the IPN GRBs in the sample, nor do we find evidence for a population of weak gravitational wave signals associated with the GRBs. For all IPN-detected GRBs, for which a sufficient duration of quality gravitational wave data are available, we place lower bounds on the distance to the source in accordance with an optimistic assumption of gravitational wave emission energy of 10(-2)M⊙c(2) at 150 Hz, and find a median of 13 Mpc. For the 27 short-hard GRBs we place 90% confidence exclusion distances to two source models: a binary neutron star coalescence, with a median distance of 12 Mpc, or the coalescence of a neutron star and black hole, with a median distance of 22 Mpc. Finally, we combine this search with previously published results to provide a population statement for GRB searches in first-generation LIGO and Virgo gravitational wave detectors and a resulting examination of prospects for the advanced gravitational wave detectors.

Search for gravitational waves associated with γ-ray bursts detected by the interplanetary network

We present the results of a search for gravitational waves associated with 223 γ-ray bursts (GRBs) detected by the InterPlanetary Network (IPN) in 2005-2010 during LIGO's fifth and sixth science runs and Virgo's first, second, and third science runs. The IPN satellites provide accurate times of the bursts and sky localizations that vary significantly from degree scale to hundreds of square degrees. We search for both a well-modeled binary coalescence signal, the favored progenitor model for short GRBs, and for generic, unmodeled gravitational wave bursts. Both searches use the event time and sky localization to improve the gravitational wave search sensitivity as compared to corresponding all-time, all-sky searches. We find no evidence of a gravitational wave signal associated with any of the IPN GRBs in the sample, nor do we find evidence for a population of weak gravitational wave signals associated with the GRBs. For all IPN-detected GRBs, for which a sufficient duration of quality gravitational wave data are available, we place lower bounds on the distance to the source in accordance with an optimistic assumption of gravitational wave emission energy of 10(-2)M⊙c(2) at 150 Hz, and find a median of 13 Mpc. For the 27 short-hard GRBs we place 90% confidence exclusion distances to two source models: a binary neutron star coalescence, with a median distance of 12 Mpc, or the coalescence of a neutron star and black hole, with a median distance of 22 Mpc. Finally, we combine this search with previously published results to provide a population statement for GRB searches in first-generation LIGO and Virgo gravitational wave detectors and a resulting examination of prospects for the advanced gravitational wave detectors.

A laboratory study for assessing speech privacy in a simulated open-plan office

The aim of this study is to assess speech privacy in open-plan office using two recently introduced single-number quantities: the spatial decay rate of speech, DL(2,S) [dB], and the A-weighted sound pressure level of speech at a distance of 4 m, L(p,A,S,4) m [dB]. Open-plan offices were modeled using a DL(2,S) of 4, 8, and 12 dB, and L(p,A,S,4) m was changed in three steps, from 43 to 57 dB.Auditory experiments were conducted at three locations with source–receiver distances of 8, 16, and 24 m, while background noise level was fixed at 30 dBA.A total of 20 subjects were asked to rate the speech intelligibility and listening difficulty of 240 Korean sentences in such surroundings. The speech intelligibility scores were not affected by DL(2,S) or L(p,A,S,4) m at a source–receiver distance of 8 m; however, listening difficulty ratings were significantly changed with increasing DL(2,S) and L(p,A,S,4) m values. At other locations, the influences of DL(2,S) and L(p,A,S,4) m on speech intelligibility and listening difficulty ratings were significant. It was also found that the speech intelligibility scores and listening difficulty ratings were considerably changed with increasing the distraction distance (r(D)). Furthermore, listening difficulty is more sensitive to variations in DL(2,S) and L(p,A,S,4) m than intelligibility scores for sound fields with high speech transmission performances.

PRACTICAL IMPLICATIONS

The recently introduced single-number quantities in the ISO standard, based on the spatial distribution of sound pressure level, were associated with speech privacy in an open-plan office. The results support single-number quantities being suitable to assess speech privacy, mainly at large distances. This new information can be considered when designing open-plan offices and making acoustic guidelines of open-plan offices.

Isotropic round-wire multifilament cuprate superconductor for generation of magnetic fields above 30 T

Magnets are the principal market for superconductors, but making attractive conductors out of the high-temperature cuprate superconductors (HTSs) has proved difficult because of the presence of high-angle grain boundaries that are generally believed to lower the critical current density, J(c). To minimize such grain boundary obstacles, HTS conductors such as REBa2Cu3O(7-x) and (Bi, Pb)2Sr2Ca2Cu3O(10-x) are both made as tapes with a high aspect ratio and a large superconducting anisotropy. Here we report that Bi2Sr2CaCu2O(8-x) (Bi-2212) can be made in the much more desirable isotropic, round-wire, multifilament form that can be wound or cabled into arbitrary geometries and will be especially valuable for high-field NMR magnets beyond the present 1 GHz proton resonance limit of Nb3Sn technology. An appealing attribute of this Bi-2212 conductor is that, being without macroscopic texture, it contains many high-angle grain boundaries but nevertheless attains a very high J(c) of 2,500 A mm(-2) at 20 T and 4.2 K. The large potential of the conductor has been demonstrated by building a small coil that generated almost 2.6 T in a 31 T background field. This demonstration that grain boundary limits to high Jc can be practically overcome underlines the value of a renewed focus on grain boundary properties in non-ideal geometries.

Costs and outcomes over 36 years of patients with phenylketonuria who do and do not remain on a phenylalanine-restricted diet

BACKGROUND

To quantify the costs and consequences of managing phenylketonuria (PKU) in the UK and to estimate the potential implications to the UK's National Health Service (NHS) of keeping patients on a phenylalanine-restricted diet for life.

METHOD

A computer-based model was constructed depicting the management of PKU patients over the first 36 years of their life, derived from patients suffering from this metabolic disorder in The Health Improvement Network database (a nationally representative database of patients registered with general practitioners in the UK). The model was used to estimate the incidence of co-morbidities and the levels of healthcare resource use and corresponding costs over the 36 years.

RESULTS

Patients who remained on a phenylalanine-restricted diet accounted for 38% of the cohort. Forty-seven per cent of patients discontinued their phenylalanine-restricted diet between 15 and 25 years of age. Of these, 73% remained off diet and 27% restarted a restricted diet at a mean 30 years of age. Fifteen per cent of the cohort had untreated PKU. Eleven per cent of patients who remained on a phenylalanine-restricted diet for 36 years received the optimum amount of prescribed amino acid supplements. Patients had a mean 12 general practitioner visits per year and one hospital outpatient visit annually, but phenylalanine levels were only measured once every 18 to 24 months. The mean NHS cost (at 2007/08 prices) of managing a PKU sufferer over the first 36 years of their life was estimated to range between £21 000 and £149 000, depending on the amount of prescribed nutrition they received.

CONCLUSION

The findings suggest that the majority of patients with PKU were under-treated. The NHS cost of patient management should not be an obstacle to encouraging patients to remain on a restricted diet until further information becomes available about the long-term clinical impact of stopping such a diet. Nevertheless, patients require counselling and managed follow up regardless of the choices they make about their diet.

Vitamin D and type 2 diabetes mellitus

WHAT IS KNOWN AND OBJECTIVE

The deleterious effect of vitamin D deficiency on bone health has long been known. More recent studies suggest a deleterious effect of low vitamin D (hypovitaminosis D) on general health. And specific studies propose an association between hypovitaminosis D and the aetiology and progression of type 2 diabetes (T2DM). Given a commonly assumed lack of toxicity of vitamin D, routine measurement of plasma vitamin D and supplementation is rapidly becoming accepted general practice.

COMMENT

Authoritative practice guidelines have raised the level of vitamin D that is to be considered minimal for optimum health. This recommendation was based on a wealth of information and definitive evidence for skeletal benefits of vitamin D, but there was a lack of compelling evidence that hypovitaminosis D is causally related to extra-skeletal health outcomes such as diabetes. Hence, vitamin D supplementation for the purpose of achieving a level consistent with good health is evidence based, but measurement and supplementation for the purpose of preventing or treating T2DM is not.

WHAT IS NEW AND CONCLUSION

Although the maintenance of adequate vitamin D levels is desirable for all patients, we conclude that routine measurement of vitamin D level in every patient or initiating high-dose supplementation for the purpose of preventing or treating T2DM is not evidence based.

Long-term needs of adult patients with organic acidaemias: outcome and prognostic factors

BACKGROUND

With improvements in the treatment of children with organic acidaemias (OA), the number surviving to adulthood is increasing. To plan appropriate services for their care it is important to know what their needs are.

OBJECTIVE

To describe the clinical and social problems affecting adult patients with OA.

PATIENTS AND METHODS

We reviewed the medical records of 15 adult patients diagnosed with OA. Social attainment (housing, schooling and occupation) was analysed. Nutritional status was evaluated by body mass index (BMI) and laboratory studies. Neurological and visceral complications were noted. Cognitive outcome was evaluated by psychometric testing and/or educational attainment.

RESULTS

Seven had methylmalonic acidaemia (MMA), 4 isovaleric acidaemia (IVA) and 4 propionic acidaemia (PA). Ten were female, and median age was 23.5 years (range 18-48). All but three had late-onset disease. Two patients became pregnant during follow up. Four patients had obtained university degrees and were working. Three-quarters of the patients required some kind of social support. All had a good nutritional status. Height was normal in IVA and 3 PA patients. Osteoporosis was present in 2 out of 8 patients assessed. A variety of neurocognitive or visceral complications were seen in two-thirds of the patients. Metabolic decompensations were unusual.

CONCLUSIONS

The approach to adult patients with OA has to be multidisciplinary, with the clinician and dietician as the core of the team, but with the collaboration of clinical nurses specialists, social workers and other specialist services and the support of a biochemical and molecular laboratory.

Adults with late diagnosed PKU and severe challenging behaviour: a randomised placebo-controlled trial of a phenylalanine-restricted diet

BACKGROUND

Although early diagnosis and treatment in phenylketonuria (PKU) leads to excellent outcomes, a population of adults born before the introduction of newborn screening exists. They can have severe intellectual disabilities and behavioural problems, and are often dependent on full-time carers. Anecdotal evidence suggests that a diet that lowers blood phenylalanine concentration can have significant benefits upon behaviour.

METHODS

A prospective double-blind randomised placebo-controlled crossover trial of phenylalanine-restricted diet was performed in a group of 34 adults (aged 21-61 years, median 49) with late diagnosed PKU with severe challenging behaviour.

RESULTS

Only 17 completed the 60 week study: seven withdrew before the end of the baseline period; five withdrew during the first diet period; five withdrew during the second diet period (after moving into placebo phase). The mean (SD) blood phenylalanine was 1570 (222) micromol/l during baseline, 553(158) mumol/l during the active phase and 1444 (255) micromol/l during the placebo phase. In the 22 participants exposed to both active and placebo phases, no differences were demonstrated in behaviour assessed by the Aberrant Behavior Checklist and Vineland Adaptive Behavior Scales, behaviour diaries or on video analysis of direct observations. However, 76% of carers' comments were scored as positive during the active phase, compared with 54% during the placebo phase (chi(2) = 38.06, p<0.001).

CONCLUSIONS

There are significant challenges in studying people with intellectual disabilities and considerable difficulties in instituting phenylalanine-restricted diet in this population. However, if attempted, there are potential benefits to quality of life for the individuals with PKU and their carers.

Sacrococcygeal pilonidal disease

BACKGROUND

Sacrococcygeal pilonidal is a common disease in active young adults. Many surgical methods have been proposed, although no clear consensus as to the optimal treatment has been reported. This review looks at the different surgical techniques available and examines the reported results of primary healing, recurrent disease and complications (including delayed healing).

METHOD

A literature search using the Medline database was performed to locate English language articles on surgery for pilonidal disease. Further articles were obtained from the references cited in the literature initially reviewed.

RESULTS

Management should be tailored according to the individual and whether the disease is acute or chronic. Treatment should take into consideration hospital stay and return to work. Simple excision, curettage, partial lateral wall excision, or marsupialisation, are simple techniques with good results. They can be used for the initial surgery but their use is not recommended for recurrent disease. The modified rhomboid flap for recurrent disease has consistently shown positive results in terms of complication rates and recurrence.

CONCLUSION

We would recommend tailored treatment with simple excision for initial presentation and the modified rhomboid flap for recurrent disease.

Effects of six APOA5 variants, identified in patients with severe hypertriglyceridemia, on in vitro lipoprotein lipase activity and receptor binding

OBJECTIVE

The purpose of this study was to identify rare APOA5 variants in 130 severe hypertriglyceridemic patients by sequencing, and to test their functionality, since no patient recall was possible.

METHODS AND RESULTS

We studied the impact in vitro on LPL activity and receptor binding of 3 novel heterozygous variants, apoAV-E255G, -G271C, and -H321L, together with the previously reported -G185C, -Q139X, -Q148X, and a novel construct -Delta139 to 147. Using VLDL as a TG-source, compared to wild type, apoAV-G255, -L321 and -C185 showed reduced LPL activation (-25% [P=0.005], -36% [P<0.0001], and -23% [P=0.02]), respectively). ApoAV-C271, -X139, -X148, and Delta139 to 147 had little affect on LPL activity, but apoAV-X139, -X148, and -C271 showed no binding to LDL-family receptors, LR8 or LRP1. Although the G271C proband carried no LPL and APOC2 mutations, the H321L carrier was heterozygous for LPL P207L. The E255G carrier was homozygous for LPL W86G, yet only experienced severe hypertriglyceridemia when pregnant.

CONCLUSIONS

The in vitro determined function of these apoAV variants only partly explains the high TG levels seen in carriers. Their occurrence in the homozygous state, coinheritance of LPL variants or common APOA5 TG-raising variant in trans, appears to be essential for their phenotypic expression.

Reduction in bone mineral density in glycogenosis type III may be due to a mixed muscle and bone deficit

Glycogen storage disease type III (GSD III; OMIM 232400) is an autosomal recessive deficiency of the glycogen debrancher enzyme, amylo-1,6-glucosidase (EC 3.2.1.33). Patients with other hepatic glycogenoses are known to have reduced bone mineral content (BMC) and to be at consequent risk of fractures. They have key metabolic differences from GSD III patients, however. This study examines bone density and metabolism in 15 GSD III patients (6 female) from childhood to adulthood (aged 10-34 years). The results demonstrate that patients with GSD III have low bone mass at all skeletal sites compared with healthy individuals of the same age and sex, with a significant proportion (40-64%) having BMD > 2 standard deviations below the mean for whole body and lumbar spine. The deficiency seems to be attributable to a mixed muscle andbone deficit. Lower bone mass was found at all sites for GSD IIIa patients (combined liver and muscle defect) compared with GSD IIIb patients (liver only defect).

CONCLUSION

Patients with GSD III have significantly abnormal bone mass, placing them at increased risk of potential fracture. The underlying mechanism is probably multifactorial with contributions from abnormal muscle physiology, abnormal metabolic milieu and altered nutrition affecting micronutrient intake. Therapies need to address all these factors to be successful.

Enlargement of the proximal pituitary stalk associated with spontaneous recovery from multiple pituitary hormone deficiencies

We report the case of a child with multiple pituitary hormone deficiencies and a truncated pituitary stalk on MR imaging who had recovery of normal secretion of pituitary hormones in early adulthood. Follow-up MR imaging examination after recovery revealed marked enlargement of the proximal pituitary stalk. The case of our patient helps to explain the mechanism whereby some patients experience recovery of hormonal function.

Atoms in a radio-frequency-dressed optical lattice

We load cold atoms into an optical lattice dramatically reshaped by radio-frequency coupling of state-dependent lattice potentials. This radio-frequency dressing changes the unit cell of the lattice at a subwavelength scale, such that its curvature and topology departs strongly from that of a simple sinusoidal lattice potential. Radio-frequency dressing has previously been performed at length scales from mm to tens of mum, but not at the single-optical-wavelength scale. At this length scale significant coupling between adiabatic potentials leads to nonadiabatic transitions, which we measure as a function of lattice depth and dressing amplitude. We also investigate the dressing by measuring changes in the momentum distribution of the dressed states.

Depression in adults with Fabry disease: a common and under-diagnosed problem

BACKGROUND

Anderson-Fabry disease (AFD), an X-linked lysosomal storage disorder, leads to multi-organ dysfunction and premature mortality. Depression in adults with AFD has been reported, but no large study has been done. We have examined the adult Fabry population in the United Kingdom to describe the prevalence, associated factors and frequency of diagnosis of depression.

METHODS

Postal questionnaires were sent from four adult clinics to 296 AFD patients. A response rate of 62% (n = 184; 74 male, 110 female) formed the data set. Questionnaires collected demographic and Fabry-specific information. Depression status was assessed using the Centre for Epidemiological Studies depression scale (CES-D).

RESULTS

Responders were aged between 18 and 76 years (mean 44). The prevalence of depression was 46%, of which 28% were consistent with 'severe clinical depression'. Unlike the normal population, males with AFD report a higher prevalence of severe depression than females (36% males; 22% females). Interference of AFD symptoms with individuals' lives (particularly acroparaesthesiae or anhidrosis) showed the largest odds of association with depression. Relationship and financial status proved strong predictors of depression: 88% of those with mild-moderate depression and 72% with severe depression were undiagnosed.

CONCLUSION

Depression is common and under-diagnosed in AFD. Proper assessment of and treatment for depression could improve the quality of life of these patients.

Sublattice addressing and spin-dependent motion of atoms in a double-well lattice

We load atoms into every site of an optical lattice and selectively spin flip atoms in a sublattice consisting of every other site. These selected atoms are separated from their unselected neighbors by less than an optical wavelength. We also show spin-dependent transport, where atomic wave packets are coherently separated into adjacent sites according to their internal state. These tools should be useful for quantum information processing and quantum simulation of lattice models with neutral atoms.

A novel starch for the treatment of glycogen storage diseases

OBJECTIVE

To determine whether a new starch offers better short-term metabolic control than uncooked cornstarch in patients with glycogen storage diseases (GSDs).

STUDY DESIGN

A short-term double-blind cross-over pilot study comparing uncooked physically modified cornstarch (WMHM20) with uncooked cornstarch in patients with GSD types Ia, Ib and III. Twenty-one patients (ages 3-47, 9 female) were given 2 g/kg cornstarch or WMHM20 mixed in water. Blood glucose, lactate and insulin, and breath hydrogen and (13)CO2 enrichment were measured, at baseline and after each load. The hourly biochemical evaluations terminated when blood glucose was < or = 3.0 mmol/L, when the study period had lasted 10 h or when the patient wished to end the test. The alternative starch was administered under similar trial conditions a median of 10 days later.

RESULTS

The median starch load duration was 9 h for WMHM20 versus 7 h for cornstarch. Glucose decreased more slowly (p = 0.05) and lactate was suppressed faster (p = 0.17) for WMHM20 compared with cornstarch. Peak hydrogen excretion was increased (p = 0.05) when cornstarch was taken.

CONCLUSION

These data indicate longer duration of euglycaemia and better short-term metabolic control in the majority of GSD patients with WMHM20 compared to cornstarch.

Preparing and probing atomic number states with an atom interferometer

We describe the controlled loading and measurement of number-squeezed states and Poisson states of atoms in individual sites of a double well optical lattice. These states are input to an atom interferometer that is realized by symmetrically splitting individual lattice sites into double wells, allowing atoms in individual sites to evolve independently. The two paths then interfere, creating a matter-wave double-slit diffraction pattern. The time evolution of the double-slit diffraction pattern is used to measure the number statistics of the input state. The flexibility of our double well lattice provides a means to detect the presence of empty lattice sites, an important and so far unmeasured factor in determining the purity of a Mott state.

A practical approach to maternal phenylketonuria management

More women with phenylketonuria are becoming pregnant and need appropriate management to avoid the effects of raised phenylalanine on the fetus: facial dysmorphism, microcephaly, growth retardation, developmental delay and congenital heart disease. Here we describe our experiences from a single centre gained over almost three decades. A series of six cases is presented to illustrate key points in management. Ideally, phenylalanine-restricted diet is started before conception in a planned fashion, but some women present pregnant and blood phenylalanine must be lowered rapidly. The aims of management are to maintain blood phenylalanine concentration in the target range (100-250 micromol/L) before and throughout the pregnancy, and to ensure adequate maternal nutrition and appropriate weight gain. Blood phenylalanine is monitored twice, three times a week, before and after conception respectively. Weight is monitored on a weekly basis and key micronutrients are monitored every 6-8 weeks in clinic. From the second trimester onwards, dietary phenylalanine intake has to be promptly increased, as phenylalanine tolerance increases rapidly. Postnatal management includes a neurological assessment of the infant at 4-8 weeks and an echocardiogram for infants conceived off diet. Subsequently, offspring are seen at 1 year, 4 years, 8 years and 14 years for neuropsychometric evaluations. Regular follow-up of the mother remains important whether on or off a phenylalanine-restricted diet.

A rationale for cystine supplementation in severe homocystinuria

Previous studies have shown that the thiol redox, as measured by the ratio of free/bound cyst(e)ine in unaffected individuals, remains relatively constant. In severe homocystinuria (HCU) where cyst(e)ine moieties are significantly reduced, this redox is only restored when homocyst(e)ine moieties are also taken into account. This appears to stem from an increase in the free/bound homocyst(e)ine ratio with free homocystine acting as a surrogate for free cystine. We examined these ratios in 47 patients (two with a cobalamin C defect, two with methylenetetrahydrofolate reductase deficiency, 16 with pyridoxine-responsive HCU and 27 with pyridoxine-nonresponsive HCU). Comparing free/bound homocyst(e)ine ratios to the total cysteine concentration indicates a relative increase of free homocystine as total cysteine concentrations fall below 170 micromol/L. This provides a rationale and treatment algorithm for cyst(e)ine supplementation in homocystinuria.

Frequency of metabolic disorders: more than one needle in the haystack

Perspective on the paper by Sanderson et al (see page 896)

Interface stability influences torso muscle recruitment and spinal load during pushing tasks

Handle or interface design can influence torso muscle recruitment and spinal load during pushing tasks. The objective of the study was to provide insight into the role of interface stability with regard to torso muscle recruitment and biomechanical loads on the spine. Fourteen subjects generated voluntary isometric trunk flexion force against a rigid interface and similar flexion exertions against an unstable interface, which simulated handle design in a cart pushing task. Normalized electromyographic (EMG) activity in the rectus abdominus, external oblique and internal oblique muscles increased with exertion effort. When using the unstable interface, EMG activity in the internal and external oblique muscle groups was greater than when using the rigid interface. Results agreed with trends from a biomechanical model implemented to predict the muscle activation necessary to generate isometric pushing forces and maintain spinal stability when using the two different interface designs. The co-contraction contributed to increased spinal load when using the unstable interface. It was concluded that handle or interface design and stability may influence spinal load and associated risk of musculoskeletal injury during manual materials tasks that involve pushing exertions.

The effect of L-alanine therapy in a patient with adult onset glycogen storage disease type II

Adult-onset glycogen storage disease type II (GSD II) (McKusick 232300) is a progressive disabling myopathy. At present there is no treatment of proven clinical efficacy. Enzyme replacement therapy may in the future provide benefit but it will be costly and is not yet freely available. L-Alanine, a simple and relatively cheap therapy, has been shown to reduce protein degradation in GSD II patients but has not previously been assessed for clinical benefit in a controlled study. In this study L-alanine was assessed in a double blind, placebo-controlled, crossover n = 1 study. Assessments consisted of spirometry, cardiopulmonary exercise testing, quality of life measurements, biochemical markers and assessment by the criterion 4-component model of body composition. Alanine therapy was associated with a 15% gain in total body protein. However, the patient showed no functional improvement and reported feeling worse after treatment. Further controlled studies in a small group may be warranted, but not widespread use of this therapy.

Problems with botulinum toxin treatment in mitochondrial cytopathy: case report and review of the literature

Botulinum toxin type A (BTXA) is widely used in neurological therapeutics for a variety of indications such as dystonia, spasticity, hyperhidrosis, and hypersalivation. It is relatively contraindicated in disorders of neuromuscular transmission, in individuals with known hypersensitivity or bleeding disorders, and during pregnancy. Two patients are presented with initially undetermined multisystem neurological disorders and excessive sialorrhoea, later diagnosed as mitochondrial cytopathy, who had side effects after treatment with ultrasound guided BTXA injections. Published reports on the use of BTXA injections in hypersalivation of various causes are reviewed, along with the proposed mechanisms of hypersensitivity to BTXA in patients with mitochondrial cytopathies. Clinicians should be cautious when using BTXA injections in such patients because of the significant risk of side effects.

Mechanism of local anesthetic drug action on voltage-gated sodium channels

Local anesthetic drugs interfere with excitation and conduction by action potentials in the nervous system and in the heart by blockade of the voltage-gated Na channel. Drug affinity varies with gating state of the channel. The drugs show low affinity at slow excitation rates, but high affinity when the channels are opened and inactivated during action potentials at high frequency, as they are during pain or during a cardiac arrhythmia. The drugs are thought to access their binding site in the inner pore by passage through the membrane and entry through the inner pore vestibule. There have been three major developments in the last decade that greatly increase our understanding of their mechanism of action. Firstly, amino acid residues critical to drug binding have been located by mutagenesis, and it is possible to develop a molecular model of the drug binding site. Secondly, a path for drug access directly from the outside has been characterized in the cardiac isoform of the channel. Thirdly, the hypothesis that high affinity binding stabilizes the fast inactivated conformation of the channel has been challenged. Rather, the drug may stabilize a slow inactivated state and immobilize the voltage sensor in domain III in its activated outward position. The combination of mutational study of the cloned Na channels and patch clamp offers the opportunity to understand the detailed molecular mechanism of drug action and to resolve drug structure-function.

Exercise capacity and biochemical profile during exercise in patients with glycogen storage disease type I

Glycogen storage disease type I (GSD-I) is an inherited disorder of carbohydrate metabolism. Hepatic glucose-6-phosphatase is deficient, leading to impaired gluconeogenesis and glycogenolysis. Patients prevent fasting hypoglycemia by frequent feeds of low glycemic index foods. Normal muscle does not contain glucose-6-phosphatase, and GSD-I is usually classified as a hepatic glycogenosis. However, clinical experience has suggested that patients have decreased cardiovascular fitness, but this had not been formally investigated. This paper reports the results of maximal treadmill cardiopulmonary exercise testing in adult patients with GSD-I. It documents a major reduction in exercise capacity in these patients and demonstrates biochemical aspects of exercise that are different from those of normal controls. All patients showed a reduction in exercise capacity, but there was a wide range of exercise tolerance. Additional work needs to address whether improved adherence to or intensification of therapy in adulthood will ameliorate exercise intolerance.

Spin-dependent forces on trapped ions for phase-stable quantum gates and entangled states of spin and motion

Favored schemes for trapped-ion quantum logic gates use bichromatic laser fields to couple internal qubit states with external motion through a "spin-dependent force." We introduce a new degree of freedom in this coupling that reduces its sensitivity to phase decoherence. We demonstrate bichromatic spin-dependent forces on a single trapped 111Cd+ ion, and show that phase coherence of the resulting entangled states of spin and motion depends critically upon the spectral arrangement of the optical fields. This applies directly to the operation of entangling gates on multiple ions.

Maternal phenylketonuria: report from the United Kingdom Registry 1978-97

BACKGROUND

The effects of maternal phenylalanine on the fetus include facial dysmorphism, microcephaly, intrauterine growth retardation, developmental delay, and congenital heart disease.

AIMS

To evaluate the impact of phenylalanine restricted diet in pregnant women with phenylketonuria (PKU) on their offspring.

METHODS

Data on virtually all pregnancies of women with PKU in the United Kingdom between 1978 and 1997 were reported to the United Kingdom PKU Registry. The effect of the use and timing in relation to pregnancy of a phenylalanine restricted diet on birth weight, birth head circumference, the presence or absence of congenital heart disease (CHD), 4 year developmental quotient, and 8 year intelligence quotient were examined.

RESULTS

A total of 228 pregnancies resulted in live births (seven twin pregnancies were excluded). In 110 (50%), diet started before conception. For this group mean (SD) birth weight was 3160 (612) g, birth head circumference 33.6 (1.9) cm, 4 year DQ 108.9 (13.2), 8 year IQ 103.4 (15.6), and incidence of CHD was 2.4%. In comparison, for those born where treatment was started during pregnancy (n = 91), birth weight was 2818 (711) g, birth head circumference 32.7 (2.0) cm, 4 year DQ 96.8 (15.0), 8 year IQ 86.5 (13.0), and incidence of CHD was 17%. Month-by-month regression analyses suggested that metabolic control by 12-16 weeks gestation had most influence on outcome.

CONCLUSIONS

Many features of the maternal PKU syndrome are preventable by starting a phenylalanine restricted diet. Women with PKU and their carers must be aware of the risks and should start the diet before conception, or as soon after as possible.

A new protein substitute for adolescents and adults with maple syrup urine disease (MSUD)

AIM

The aim was to study the efficacy and acceptability of MSUD Express in adolescent and adult patients with maple syrup urine disease (MSUD).

BACKGROUND

There are difficulties associated with current protein substitutes designed for adolescents and adults with MSUD. This can affect their metabolic control. MSUD Express is a new low-volume, nutritionally complete protein substitute, free from leucine, isoleucine and valine and designed specifically for older patients with MSUD.

METHODS

Four patients with MSUD were included in the trial (aged 16-41 years). Product dosage was 4 x 25 g sachets per day, providing 1264 kJ and 72 g amino acids: more than adequately meeting requirements for all micronutrients.

RESULTS

At the start of the study, the mean (range) of the previous eight leucine concentrations (on MSUD Aid III) was 564 micromol/L (430-817 micromol/L) and during the study (on MSUD Express) was 382 micromol/L (181-603 micromol/L). The average percentage fall in mean leucine concentrations was 32%. In patients 2, 3 and 4, low leucine levels resulted in an increase in the natural protein allowance per day. MSUD Express was rated as 'excellent' or 'good' by all patients on the basis of appearance, taste, smell and texture. All patients found the product 'very easy' to prepare and found it 'easy' or 'very easy' to take outside the home.

CONCLUSION

All patients thought the preparation of MSUD Express was 'very easy'. Metabolic control (mean leucine concentrations) improved in all of the patients. In three patients this meant that an increase in the amount of natural protein in the diet was possible. All patients elected to stay on MSUD Express after the trial period. MSUD Express appears to be an effective and acceptable product, offering an alternative to current protein substitutes available for older people with MSUD.

L-carnitine and exercise tolerance in medium-chain acyl-coenzyme A dehydrogenase (MCAD) deficiency: a pilot study

Skeletal muscle function may be impaired in patients with medium-chain acyl-CoA dehydrogenase (MCAD) deficiency, but the value of L-carnitine in their long-term management is not clear. This study was designed as a pilot to examine the effects of L-carnitine on exercise tolerance in patients with MCAD deficiency. Four clinically asymoptomatic MCAD-deficient patients, aged 8 to 20 years, were studied. Incremental ramp exercise tests were carried out before and after 4 weeks' treatment with oral L-carnitine (100 mg/kg per day). During exercise without L-carnitine supplementation, plasma carnitine concentrations fell, associated with an increased excretion of urinary acylcarnitines, notably acetylcarnitine, hexanoylcarnitine and octanoylcarnitine. L-carnitine treatment prevented this fall in plasma carnitine and resulted in greater increases in excretion of acylcarnitines. All four patients showed biologically significant improvement in peak oxygen uptake (peak VO2, 18-32% improvement), VO2 at a heart rate of 170 beats/min (15-23% improvement), VO2 at anaerobic threshold (27-42% improvement), and/or oxygen pulse (10-32% improvement). Exercise tolerance in MCAD-deficient patients may be improved by short-term L-carnitine supplementation. This may be the direct result of improved intramitochondrial homeostasis induced by L-carnitine in removing accumulating acyl moieties.

Social outcome in treated individuals with inherited metabolic disorders: UK study

Few data exist on the long-term social outcome of patients with inherited metabolic disorders, despite the fact that increasing numbers are surviving into adulthood. Here we report the findings of 329 patients aged from 11 to 70 years, of whom 172 had phenylketonuria, 38 had homocystinuria and 33 had galactosaemia. Twenty-eight per cent had no formal education qualifications, 59% were employed, but only 17% were in professional jobs (social classes I and II). The time of diagnosis and treatment had a significant impact on outcome in phenylketonuria, as did pyridoxine responsiveness or lack of it in homocystinuria. Effects on outcome in galactosaemia were not clear. Social integration is an important outcome of treatment of chronic disorders in childhood and warrants further study in this growing patient population.

Raised HDL cholesterol in Fabry disease: response to enzyme replacement therapy

Fabry disease patients have increased risk of vascular disease despite cardioprotective increased HDL-cholesterol. Enzyme therapy does not significantly alter the lipid profile in the short term.

Successful pregnancy after combined renal-hepatic transplantation in glycogen storage disease type Ia

Reports of liver and kidney transplantation and of pregnancy in glycogen storage disease type Ia (GSD Ia) (McKusick 232200) are rare. We report an individual who experienced all three successfully.