Sexual harassment, sexual assault and rape by colleagues in the surgical workforce, and how women and men are living different realities: observational study using NHS population-derived weights

BACKGROUND

This observational study, paired with National Health Service (NHS) workforce population data, examined gender differences in surgical workforce members' experiences with sexual misconduct (sexual harassment, sexual assault, rape) among colleagues in the past 5 years, and their views of the adequacy of accountable organizations in dealing with this issue.

METHODS

This was a survey of UK surgical workforce members, recruited via surgical organizations.

RESULTS

Some 1704 individuals participated, with 1434 (51.5 per cent women) eligible for primary unweighted analyses. Weighted analyses, grounded in NHS England surgical workforce population data, used 756 NHS England participants. Weighted and unweighted analyses showed that, compared with men, women were significantly more likely to report witnessing, and be a target of, sexual misconduct. Among women, 63.3 per cent reported being the target of sexual harassment versus 23.7 per cent of men (89.5 per cent witnessing versus 81.0 per cent of men). Additionally, 29.9 per cent of women had been sexually assaulted versus 6.9 per cent of men (35.9 per cent witnessing versus 17.1 per cent of men), with 10.9 per cent of women experiencing forced physical contact for career opportunities (a form of sexual assault) versus 0.7 per cent of men. Being raped by a colleague was reported by 0.8 per cent of women versus 0.1 per cent of men (1.9 per cent witnessing versus 0.6 per cent of men). Evaluations of organizations' adequacy in handling sexual misconduct were significantly lower among women than men, ranging from a low of 15.1 per cent for the General Medical Council to a high of 31.1 per cent for the Royal Colleges (men's evaluations: 48.6 and 60.2 per cent respectively).

CONCLUSION

Sexual misconduct in the past 5 years has been experienced widely, with women affected disproportionately. Accountable organizations are not regarded as dealing adequately with this issue.

Seeing White: Management of TIVA during autologous breast reconstruction

Total IntraVenous Anaesthesia is frequently the anaesthetic of choice for enhanced recovery after surgery pathways during breast reconstruction free flap surgery. This relies upon the continuous intravenous infusion of propofol. We describe our experience of two patients where augmentation of a venously congested DIEP flap with a cephalic vein transposition procedure, risked interruption of the intravenous delivery of anaesthesia to the patient. We also share our steps taken to mitigate this risk going forward.

Mastectomy Without Drains Reduces Cost with No Detriment to Patient Outcome

Introduction 

Use of drains after mastectomy remains highly variable. This study aimed to establish whether simple mastectomy managed without a drain would cost less than the same procedure managed with a drain and whether there would be any difference in complications.

Methods 

Prospective data were collected on all patients undergoing simple mastectomy ± sentinel lymph node biopsy over sixteen months. Surgeons decided intra-operatively whether to place a drain. Data included operative details, mastectomy weight, length of stay and postoperative complications. Costing data were identified by combining hospital finance costs for admission and follow-up appointments along with the cost of consumables.

Results 

One hundred and thirty mastectomies were performed on 119 patients. There was a significant difference in mastectomy weight between drain group patients (n=80, median: 730g) and no drain group patients (n=50, median: 424g) (p=<0.001). The mean cost for drain group patients was £639.77 whilst for the no drain group was £365.46, indicating a potential unit saving of £21944.93 over sixteen months. Length of stay was shorter in the no drain group (range: 1-2 days) than the drain group (range: 1-4 days). The presence or absence of drains did not influence complication rates, with no change in seroma interventions (p=0.803).

Conclusions 

Managing simple mastectomy patients without a drain resulted in no increase in complications or subsequent interventions for seroma. Significant cost savings to both the hospital and to the patient can be achieved by omitting drain use. Routine use of drains in patients undergoing simple mastectomy ± SNB may be unnecessary and costly.

Managing soft tissues in severe lower limb trauma in an ageing population

PURPOSE

With an ageing population, the incidence of trauma in those aged over 65 years is increasing. Strategies for dealing with these patients must be developed. At present the standard management of open tibial fractures in the UK is described by the BOAST4 guidelines (from the British Orthopaedic Association and British Association of Plastic & Aesthetic Surgeons). It is not clear to what extent these are appropriate for older patients. We describe our experience of managing elderly patients presenting with open tibial fractures.

METHOD

Patients were identified via prospectively collected national and departmental databases. These data were supplemented by review of the patient records and radiographs. Data collated included patient demographics, injury details, orthopaedic and plastic surgery operative details, and long-term outcomes.

RESULTS

Between January 2013 and June 2016, 74 patients aged over 65 years were admitted with open lower limb fractures. 54 of these were open tibial fractures and these patients formed the study group. 19 patients required soft-tissue reconstruction for Gustilo and Anderson IIIB tibial fractures (age range, 67-95 years). In these patients, there were 7 midshaft (AO 42), 1 proximal (AO 41), and 11 distal (AO 43) fractures. 13 patients were treated with internal fixation and 6 with circular frames. The median length of hospital stay was 27 days (range, 4-85). 14 patients received loco-regional flaps and 5 underwent free tissue transfer with one requiring preoperative femoral angioplasty. There were no flap losses. Four patients had fasciocutaneous flaps, 3 tibialis anterior transposition, 2 an extensor digitorum brevis flap, 1 a hemisoleus flap, and 4 were skin grafted. All patients went on to unite and return to their premorbid weight-bearing status (4 using walking frames, 3 using sticks, and 12 walking independently).

CONCLUSION

Although the literature suggests a significantly higher complication rate in elderly patients with open fractures, we have demonstrated comparable rates of flap survival and bony union to those observed in younger patients. Challenges are presented in terms of patient physiology and these must be carefully managed pre- and postoperatively. These challenges are reflected in prolonged hospital stays.

Managing complex trauma injuries in the elderly: a case report of a free flap and circular frame in a 95-year old patient with an open IIIB tibial fracture

In an ageing population, increasing numbers of patients over the age of 70 are sustaining severe trauma. These patients require careful multidisciplinary team (MDT) management with careful consideration of existing co-morbidities, as such their treatment should be individually tailored. We present the case of a patient believed to be the oldest documented patient treated in a trauma setting with free flap and circular frame fixation to an open tibial fracture. A 95-year-old male presented to the Level 1 Major Trauma Centre (MTC) with multiple injuries after a pedestrian vs car incident. His injury severity score (ISS) was 22. For treatment of his open tibial fracture, he required soft tissue coverage with a free anterolateral thigh (ALT) flap, and circular frame application. Microsurgery was performed after consultation with the MDT and was uneventful. The circular frame was removed after 10 months and the patient went on to regain pre-injury mobility. Use of free tissue transfer in elderly patients is well documented in the elective setting, but less so in trauma. This case demonstrates that careful patient selection, attention to detail and MDT working can result in an excellent outcome for the patient. The challenges faced in treating this patient will be described in detail.

Level of Evidence: Level V, therapeutic study.

Merkel cell carcinoma in East Yorkshire: A case series and literature review of current management

INTRODUCTION

Merkel cell carcinoma (MCC) is a rare, aggressive neuroendocrine tumour of the skin. The incidence is rising and it is associated with sun exposure and immunosuppression. Our aim was to perform a 10-year retrospective review of MCC treated in East Yorkshire and to examine disease progression, surgical and adjuvant management, and outcomes.

METHODS

A 10-year retrospective review was undertaken of patients identified through the histopathology database. Case notes and digital patient records were examined for patient demographics, disease characteristics, management and outcome. Disease stage was calculated using the 2010 AJCC TNM classification.

RESULTS

Thirty-seven patients with complete records were included. Twenty-one patients were male and 16 female, with mean age 76.7 years at presentation. Pre-malignant or malignant skin changes were documented in 15 patients, and immunosuppression in 15 patients. Mean duration of lesion was 17.5 weeks. Following diagnosis 22/37 patients underwent further surgery with 11 patients undergoing sentinel lymph node (LN) biopsy. LN disease was palpable at presentation in 8 patients. Three year survival is 40%.

CONCLUSIONS

There is no standardised management of MCC and randomised trials are challenging due to relatively small numbers. There has been little progress made in terms of improving survival. Development of a national database for patients with this condition would allow prospective data collection and more accurate assessment of current treatment protocols and their efficacy.

LEVEL OF EVIDENCE

IV.

Combined use of hyperbaric oxygen and sprayed keratinocyte suspension to tackle a difficult wound

This is the first reported case in the literature to combine the use of a well established therapy to achieve wound healing (ie hyperbaric oxygen treatment) and a novel sprayed keratinocyte suspension technique to treat a challenging wound successfully. The merits and potential issues associated with these treatments are outlined and the case is detailed.

Revised estimates of mortality from the Birmingham Burn Centre, 2001-2010: a continuing analysis over 65 years

OBJECTIVE

The Birmingham Burn Centre has continued to publish mortality data over the last 65 years. It is one of the longest running cross-sectional cohort studies in the world. We present the latest data from the study, with a comparison to previous results.

BACKGROUND

Results from the previous decade failed to show any improvement in mortality despite perceived advances in burn care. The aim of this update was to establish current mortality statistics and ascertain whether improvement had now been made.

METHODS

Data were collected for a 10-year period on all burn-injured patients admitted to the Birmingham Burn Centre (Birmingham Children's Hospital, Selly Oak Hospital, and Queen Elizabeth Hospital Birmingham). Patients' age, percentage of burn, date of injury, and outcome were recorded and analyzed with both probit and logistic regression analyses.

RESULTS

A total of 4577 patients were included in the analysis, with a mean total body surface area (TBSA) burn of 7.2% and a mean age of 22 years. Comparison of probit model results with previous results demonstrates improvement in predicted mortality and lethal area (LA50) of burns. Logistic regression produces similar results to the probit analysis. Trend analysis proved a statistically significant improvement in mortality.

CONCLUSIONS

The last decade of burn care at Birmingham Burn Centre demonstrates an improvement in predicted mortality and LA50. This reflects our structured, multidisciplinary approach to burn-injured patients, early surgical excision and wound closure, and general advances in the intensive care of patients.

Equilibrium and Ion Exchange Characteristics of Potassium and Sodium Accumulation by Barley Roots

Potassium ion and Na(+) influx and efflux rates into and from excised barley roots are compared with the maximum capacity of accumulation. Potassium ion and Na(+) influx and efflux involve a cation exchange that is independent of simultaneous exchange of the accompanying anion. These exchange fluxes depend on the concentration and cation composition of the solutions from which they originate. Selective differences between K(+) and Na(+) fluxes are sufficient to account for a cationic distribution within the roots that differs markedly from that of the external solution and that persists for extended time periods. The accumulation maximum is a cation exchange equilibrium with the cation influx and efflux rates approaching equality. The equilibrium level is independent of the individual cation fluxes and the external solution concentration. It is a finite quantity which appears to be determined by the internal anion concentration including accumulated as well as endogenous anions.

Reporting overexposures and unintended exposures in diagnostic procedures

Legislation requires the reporting to regulatory authorities of incidents in which patients have been exposed to ionizing radiation to an extent "much greater than that intended". The authorities have published guidance on what is considered to meet this requirement. However, there is still some confusion regarding, particularly, the necessity to report some unintended doses. It is believed that there is a disproportionate amount of resource spent investigating some unintended exposures because all such exposures will have an effective overexposure factor of infinity, irrespective of the magnitude of the dose and the associated risk. This paper proposes changing the definitions of "overexposure" and "unintended exposure" and the adoption of a reporting process based upon risk assessment. All records and data would be collected and, if required, reported, but investigation of individual incidents would take place only for incidents carrying a greater risk than 1 in 10,000.

Innervation of the human costovertebral joint: implications for clinical back pain syndromes

BACKGROUND

The diagnosis of pain in the upper back, shoulder, chest, and arm is often made with considerable confusion and may be accompanied by needless expense and suffering by the patient. Despite the paucity of evidence concerning the tissues and mechanisms responsible for interscapular and atypical chest pain or "pseudo-angina," practitioners of manual therapy maintain that manipulation of the costovertebral elements and associated soft tissues may be helpful in the treatment of these painful conditions.

OBJECTIVE

We have examined the costovertebral complex in humans with respect to the presence of immune-like reactivity to neurofilament protein and the neuropeptide substance P and calcitonin gene-related peptide, markers that reveal the presence of axons in peripheral tissues.

DESIGN

Human costovertebral complexes obtained at autopsy were processed with standard histologic examination and immunocytochemical methods to detect the presence of neurofilaments, substance P, and calcitonin gene-related peptide.

MAIN OUTCOME MEASURES

Outcomes were descriptive and did not require statistical methods.

RESULTS

All costovertebral joints contained innervation within the anterior capsule and synovial tissues. In 4 separate cases, the costovertebral joints contained large intraarticular synovial inclusions or "meniscoids" found to contain small bundles of axons with immune-like reactivity to substance P. Axon bundles were identified in serial section with monoclonal antibodies to neurofilaments as well as with urea-silver nitrate staining.

CONCLUSIONS

The costovertebral joint has been considered a candidate for producing back pain and/or pseudo-angina that may be ameliorated by spinal manipulation. This study has demonstrated that the costovertebral joint has the requisite innervation for pain production in a similar manner to other joints of the spinal column.

Axosomatic synapses of the rat ciliary ganglion

We have identified four different types of axosomatic synapses within the rat ciliary ganglion, and present the three-dimensional relationships of both pre- and postsynaptic elements. The majority of axosomatic synapses are situated on small postsynaptic spines that simply appose the axon (termed somatic spine), or are situated within an axonal invagination (termed invaginating somatic spine). The somatic spine synapse predominates, composing 70% of the population, which may be due to simplicity of construction as it usually forms only one active zone. In contrast, the invaginating somatic spine forms multiple active zones and accounts for only 22% of the population. Synapses involving a regular nonspinous portion of the cell membrane were rarely encountered (6%; termed somatic), as were those of axon branches situated within tubular invaginations of the cell body (2%; termed tunnelling). Synapses were differentially distributed, occurring four times more frequently on that portion of neuronal cell body membrane adjacent to the glial cell perinuclear area. However, there was no preferred location by synapse type, suggesting that this unequal distribution was the result of a general mechanism. The neuronal cells of the rat ciliary ganglion apparently constitute a single population, at least on the basis of cell size, shape, and organelle content.

Patch-clamp recording from identified rat ciliary ganglion neurons in primary culture

Adult rat parasympathetic ciliary ganglion (CG) neurons were retrogradely labelled by intraocular injection of the carbocyanine fluorescent dye 1,1-dioleyl-3,3,3',3'-tetramethylindocarbocyanine methanesulfonate (DiI). Whole-cell and nystatin perforated patch recording techniques were then used to examine the electrophysiological properties of labelled CG neurons growing in primary culture. The resting membrane potential of CG neurons in dissociated cell culture was -50 +/- 8 mV, and isolated neurons fired overshooting action potentials in response to depolarizing current injection. Voltage-clamp recordings of membrane currents revealed a transient tetrodotoxin-sensitive Na+ inward current and both sustained and transient outward K+ currents. Sustained outward K+ current was reduced (55-77%) by 5 mM tetraethylammonium and to a lesser extent (42-46%) by superfusion with nominally Ca2+ free external solution. Transient outward current was blocked by 100 microns 4-aminopyridine and exhibited steady-state inactivation at potentials depolarized to -50 mV. These data demonstrate that identified adult mammalian CG neurons can be successfully maintained in culture. Cultured CG neurons retain electrical excitability, with voltage-sensitive Na+ and K+ currents giving rise to action potentials.

Ultrasound quantitation of respiratory organ motion in the upper abdomen

Organ motion can cause artefacts in abdominal imaging particularly with magnetic resonance imaging (MRI), and may often limit the diagnostic quality of an image. If spatial resolution and image quality are to improve in MRI and other imaging techniques, a more detailed understanding of organ motion is required. Despite the importance of organ motion little quantitative information is available to date. This study was the continuation of work instigated to investigate and quantify respiratory movements of upper abdominal organs for a group of healthy volunteers in order to provide the design criteria for a motion test object for use in MRI. A previous phase of the project allowed construction of a test object but refinements were needed to represent respiratory motion more closely as a consequence of the data presented in this paper. Improvements in the scanning technique and the recording procedure have revealed that, contrary to our initial findings, motion of the diaphragm and liver is predominantly in the superior-inferior (SI) direction with an average displacement (+/- SD) (quiet respiration) of 12 +/- 7 mm (range 7-28 mm) and 10 +/- 8 mm (range 5-17 mm), respectively. For some volunteers, motion of the kidneys can be complex, especially during deep inspiration. New data have been provided by this phase of the motion study on the displacement, velocity and acceleration of abdominal organs as a function of time. These data show that MRI motion artefact reduction techniques which assume that either organ displacement, velocity or acceleration are constant are only applicable during certain phases of the respiratory cycle.

Phantoms for studying the acceleration and turbulence of liquids using magnetic resonance imaging

Magnetic resonance angiography is a relatively new method used to image vascular structure. However, a limitation manifested through signal loss due to non-stable flow makes this technique unreliable for directly visualizing occlusions and estimating the degree of stenosis. In this study, a quantitative approach is developed to understand further the situations where signal loss occurs and a phase mapping technique is used quantitatively to study acceleration in test objects designed to generate flow disturbance. In regions of acceleration the correlation coefficient between magnetic resonance imaging velocity and the inverse of area was r > 0.999 (p < 0.001). The range of acceleration calculated was 6514-63,053 mm s-2 and at maximum acceleration the measured velocity had a systematic error of 4.0(+/- 2.0)% and coefficient of variation of 3.1%. Test objects were devised and utilized for demonstrating non-stable flow and jet formation with comparison being made to predictions from fluid dynamics theory.

A comparative study of velocity measurements in major blood vessels using magnetic resonance imaging and Doppler ultrasound

Velocity measurements in major blood vessels were obtained in studies of volunteers using magnetic resonance imaging (MRI) and compared with Doppler ultrasound (US). The vessels studied were the abdominal aorta, superior mesenteric artery, common carotid artery, superficial femoral artery and middle cerebral artery. Using a paired t-test, no significant difference was found between velocity values estimated by MRI and US (p > 0.08). The relative advantages of each technique in radiological practice are discussed.

The development of equipment for the technical assessment of respiratory motion induced artefacts in MRI

A device and technique to study the effects of respiratory motion on the quality of magnetic resonance images is proposed. The construction of the device enables a variety of test objects to be mounted and used in the evaluation of imaging parameters that may be affected by motion. The equipment is constructed of cast acrylic and the movement is actuated and controlled pneumatically thus ensuring that there are no interactions with the magnetic field and radiofrequency detection system to cause further image artefacts. Separate studies have been performed, using ultrasound, to assess the degree and rate of movement of organs owing to respiration in order to derive the motion parameters for the apparatus. Preliminary results indicate that the technique produces motion induced artefacts simulating those which are the result of the effects of respiration.

An image processing technique for the identification of contact pixels applied to x-ray CT images of implanted hip prostheses

Uncemented prosthetic joint implants used in orthopaedic surgery are usually coated with a porous surface to encourage bone ingrowth. Better contact between the endosteal bone and the porous surface improves ingrowth, and such contact may be increased if the joint further subsides into position in the first weeks following implantation. An image processing technique has been developed as part of a study undertaken to determine the effect of early subsidence on endosteal contact. The method provides a measure of the degree of contact between the surfaces from transverse x-ray CT images, but is suitable for application to any image with a similar intensity distribution.

An evaluation of the accuracy of flow measurements using magnetic resonance imaging (MRI)

A study was undertaken to examine the accuracy and precision of the measurement of flow by magnetic resonance imaging (MRI) with consideration to the equipment and patient related parameters that might be encountered in vivo. For this purpose, test objects were devised consisting of PVC tubing, in which the internal diameter simulated the size of the arteries in the body. The design of the test objects ensured that steady laminar flow was obtained in the sections being imaged. The calibration study suggests that, using MRI, flow can be measured in vitro with systematic error of better than 7.0 +/- 5.0% and random error of better than 7.5%. In general, flow measurements obtained from MRI were found to correlate well with the known flows. However, the results indicated that there are prerequisite conditions for the validity of the measurements, such as the selection of appropriate flow pulse sequences and velocity limits. Measurements taken at vertically 40 mm away from the isocentre of the magnetic field were significantly different (p less than 0.01) from that at the isocentre.

Monte Carlo modelling of light propagation in breast tissue

Light transport in three-dimensional plane-parallel tissue slabs has been modelled by Monte Carlo analogue simulation. The model design has allowed the study of transmission properties that are pertinent to imaging systems for the detection of breast cancer. An important aspect of the investigations is that they make use of data obtained from quantitative measurements of light scattering and absorption in normal and pathological breast tissues. It is shown that an imaging technique which used a raster scanning laser and detector arrangement and plane-parallel compression of the breast could have considerable advantages in terms of improved transmittance, spatial unsharpness and contrast. Time-of-flight gating of images is also found to be beneficial provided that the light intensities after temporal filtering remain adequate.

Optical attenuation characteristics of breast tissues at visible and near-infrared wavelengths

Optical experiments are described for measuring the attenuation characteristics of breast tissues at visible and near-infrared wavelengths. Total attenuation coefficients post mortem were measured directly in thin tissue sections. They are usually within the range from 10 to 30 mm-1, are rather higher in fat than in fibroglandular specimens and decrease with increasing wavelength. The scattering phase function is strongly forward-peaked with the mean cosine of scattering in the range from 0.85 to 0.97 and appearing more forward-peaked in fat than in fibroglandular tissue. The reduced scattering coefficient is of the order of 1 mm-1 in all tissues. Absorption coefficients were measured indirectly in optically thick sections. They are typically between 0.1 and 0.5 mm-1 at wavelengths around 580 nm and an order of magnitude lower at 850 nm. At 580 nm and shorter wavelengths the absorption in carcinoma is significantly higher than in adjacent uninvolved tissue. Significant differences were observed in the first-order derivatives of the transmission spectra of carcinoma and surrounding tissues at certain infrared wavelengths. Transmission spectra measured in vivo across the wavelength range from 500 to 860 nm have a similar form to the spectra of excised samples. Linear absorption coefficients are generally of the same order of magnitude as those found in vitro although they are lower at green wavelengths.

Posthatch day/night differences in synaptic ribbon populations of the chick pineal

Pineal synaptic ribbon (SR) populations of the early posthatch white leghorn chick were counted to determine if they demonstrate a rhythm that is in accordance with the light/dark cycle. SRs were counted between day 7 and day 10 and on day 14 of posthatch development, with samples at midlight, middark (14L:10D), and constant darkness. SR populations did not exhibit significant changes on days 7 and 8 under cycled lighting conditions nor on days 9 and 10 under constant darkness. A second experiment demonstrated that the dark:light ratio of SR populations of day 14 chicks, under cycled lighting, was 3.4:1.0, indicating SR rhythmicity by that stage of development. In that a preliminary experiment had demonstrated a 4.2:1.0 dark:light ratio in SR populations in a predominantly day-10 population of chicks, we believe that SR rhythmicity begins on, or near, day 10 of posthatch development. To determine if the invasion of sympathetic fibers from the superior cervical ganglion (SCG) correlates with the initiation of SR light/dark population differences, we employed tyrosine hydroxylase immunofluorescence to reveal the distribution of catecholaminergic fibers in chick pineal follicles. Follicular innervation doubled over the day 7 to day 14 period, during which time light/dark differences in SR populations were established. There is a correlation, in time, between the invasion of the pineal by the sympathetic fibers and the initiation of SR light/dark differences. The circadian rhythm of pineal N-acetyltransferase (NAT) activity, the rate-limiting enzyme in the melatonin pathway, is established earlier (day 2) than the light/dark differences in SR populations (day 10). It is possible that SR rhythmicity is influenced by the ingrowth of the pineal sympathetic innervation, and that SRs respond to an extrapineal oscillator rather than the independent oscillators of the chick pineal responsible for the rhythm of NAT activity and melatonin synthesis.

Dosimetry of intrathecal iodine131 monoclonal antibody in cases of neoplastic meningitis

Radioiodinated monoclonal antibodies (MCA) were administered by the lumbar route into the cerebrospinal fluid (CSF) of four patients with malignant leptomeningeal disease. Evidence suggesting uptake of 131I-MCA by tumour sites was seen in scintigrams. Dosimetry calculations were carried out, assuming that a proportion of the administered radionuclide was bound as a thin layer on the CSF surfaces of the meninges. The percentage injected dose and the clearance curves for the head and four spinal segments were obtained by scintigraphy after administration of tracer amounts of 131I-MCA (7-18 MBq). Although radioisotope levels in the central nervous system (CNS) fell, as determined by both external scintillation counting and direct CSF sampling, a marked difference in the measurements developed with respect to time. The ratio of these two measurements reached a maximum of 49:1, 7 days after monoclonal antibody administration. Patients subsequently received therapeutic amounts (870-1600 MBq) of 131I-MCAs, resulting in clinical remissions and prolonged survival. The mean absorbed radiation dose was estimated as 3.9 cGy.MBq-1 to the thoraco-lumbar region of the spine and 0.51 cGy.MBq-1 to the outer surface of the brain. The maximal dose delivered to the surface of the CNS in the region of the spine and brain was 5800 and 600 cGy, respectively.

New scans from old: digital reformatting of ultrasound images

Two-dimensional images obtained using ultrasound have been digitized from videotape recordings and stored within a maximum of 240 digital memory planes to form a three-dimensional data set using a commercially available image processing unit. This data set has been manipulated to produce images in planes perpendicular to the original scan set. The reformatted images represent not only the scans that could have been obtained by rotating the scan head but also demonstrate planes that are not accessible by conventional scanning. The system has been evaluated with a tissue-equivalent phantom to determine the geometric accuracy of the reformatting process. Clinical material has also been used to evaluate the practical value of such a technique and to highlight difficulties that may be encountered in its routine use.

New approaches to transillumination imaging

A review of the current state of transillumination imaging for the detection and diagnosis of breast cancer and the difficulties that impede more widespread acceptance of the methods is presented. An outline is given of the physical models that may be used to describe the propagation and scattering of light in a tissue matrix and how these models might be valuable in identifying imaging improvements. Some of the proposals for future imaging arrangements are described and the preliminary work on a system for light transmission computed tomography is presented.

The accuracy of digital subtraction angiography for the quantification of atherosclerosis

Digital subtraction angiography (DSA) allows the degree of arterial patency or stenosis to be rapidly quantified. We have assessed the accuracy with which a single-plane DSA system is able to quantify area patency by densitometric and geometric methods. Arterial phantoms were designed to test for systematic error; intra-arterial DSA images of critical lesions of the carotid bifurcation and the lower abdominal and peripheral vessels were used to determine intra- and interobserver reproducibility. The densitometric method, which was more accurate than the geometric method, had a mean systematic error of up to 4% and a mean intra-observer variability of about 15% (coefficient of variation). We have identified the principal sources of inaccuracy and ways in which it may be reduced.

Catecholaminergic properties of cholinergic neurons and synapses in adult rat ciliary ganglion

Parasympathetic neurons of the ciliary ganglion are innervated by preganglionic cholinergic neurons whose cell bodies lie in the brain stem; the ganglion cells in turn provide cholinergic innervation to the intrinsic muscles of the eye. Noradrenergic innervation of the iris is supplied by sympathetic neurons of the superior cervical ganglion. Using immunocytochemical and histochemical techniques, we have examined the ciliary ganglion of adult rats for the expression of cholinergic and noradrenergic properties. As expected, the postganglionic ciliary neurons possessed detectable levels of choline acetyltransferase immunoreactivity (ChAT-IR). Unexpectedly, many ciliary neurons also exhibited immunoreactivity for tyrosine hydroxylase (TH-IR). Some had dopamine beta-hydroxylase-like (DBH-IR) immunoreactivity, but none contained detectable catecholamines, even after treatment with nialamide and L-DOPA. A sparse plexus of fibers exhibiting faint TH-IR was present in the irises of acutely sympathectomized rats. The terminals of preganglionic axons in the ciliary ganglion exhibited not only immunoreactivity for ChAT, but also for TH and contained stores of endogenous catecholamine. Neither ciliary neurons nor their preganglionic innervation accumulated detectable stores of exogenous catecholamines. Rats sympathectomized as neonates by treatment with 6-hydroxydopamine subsequently had a greater proportion of neurons possessing detectable TH-IR in the ciliary ganglion; both the TH-IR perikarya and their axons in the iris were more intensely immunofluorescent. TH-IR was present in the ciliary neuron cell bodies of mouse, guinea pig, and ferret. These species, however, lacked detectable TH-IR or catecholamine stores in preganglionic terminals. These observations indicate that mature, functionally cholinergic neurons from 2 different embryonic origins, postganglionic ciliary neurons derived from the neural crest and preganglionic neurons derived from the neural tube, display several catecholaminergic properties.

Osteoporosis and amenorrhea in young women

Bone density of the radius was measured using both standard photon absorptiometry and X-ray computed tomography (CT) scanning, and of the femur using CT, in 21 young women with amenorrhea and estrogen deficiency due to hyperprolactinemia, 8 due to ovarian failure or weight loss, 17 postmenopausal women with bone fractures presumed to be due to osteoporosis, and 36 young normal controls. Bone density in the postmenopausal women was reduced by 18-20% in the radius and 11% in the femur (p less than 0.001). In the hyperprolactinemic group bone density was significantly reduced only in the femur (by 4%, p less than 0.01). Bone density appeared to be reduced in the other young amenorrheic women both in the radius (by 2-5%) and the femur (3%) but the difference was not significant, although the group was small. This and other studies of bone density suggest the need for prophylactic treatment to prevent osteoporosis in young women with amenorrhea and estrogen deficiency, whatever the cause.

The development of a system for transillumination computed tomography

A transillumination computed tomography system has been developed for studies of the breast, testes, neonatal skull and peripheral limbs. Initial experiments on test objects have emphasised the problems of scattering and geometrical dependence of lesion detection that are likely to be encountered in conventional diaphanography, but have demonstrated the feasibility of computed tomography as a means of improving the sensitivity of the transillumination technique. The problems of transillumination computed tomography have been addressed and further areas of research identified.

Development of synaptic connections between muscle sensory and motor neurons: anatomical evidence that postsynaptic dendrites grow into a preformed sensory neuropil

The anatomical development of muscle sensory arbors and dendrites of brachial motoneurons in the spinal cord of the bullfrog was studied by labeling both types of cells with horseradish peroxidase. Sensory and motoneurons were labeled in tadpoles (stages XV-XVIII) by backfilling the triceps nerve in vivo with HRP throughout the stages in development when functional monosynaptic connections between these cells are first being formed. Individual triceps motoneurons were injected with HRP in other tadpoles at the same developmental stages. By stage XV, triceps sensory afferents already projected to and arborized in the ventral sensory neuropil region of the spinal cord where sensory-motor connections are made. In contrast, the dendrites of triceps motoneurons rarely were present in this region until stage XVI. By stage XVII, triceps dendrites in this region were common and they intermingled with the collaterals of muscle sensory axons. Thus, sensory axons supplying limb muscles grow into the future neuropil region well in advance of the arrival of motoneuronal dendrites. Electrophysiological studies have shown that the connections between triceps sensory and motor neurons are already specific at stage XVII, as soon as monosynaptic potentials between these cells can be detected (Frank and Westerfield: J. Physiol. (Lond.) 343:593-610, '83). The present anatomical results demonstrate that the processes of sensory and motor cells are not in close anatomical proximity before this time; thus the selection of appropriate synaptic partners must occur from the outset.

Innervation of the iris by individual parasympathetic axons in the adult mouse

Ciliary neurones were identified electrophysiologically in isolated ganglia and the projection of individual axons to the intrinsic muscles of the eye determined by labelling identified cells with horseradish peroxidase (HRP). The ciliary ganglion of the adult mouse contains 80-100 parasympathetic neurones clustered at the point where the oculomotor nerve branches to supply the medial and inferior rectus. These nerve cells show varying degrees of dendritic complexity (zero to six primary dendrites) and differing degrees of innervation by preganglionic axons (one to seven inputs). Cells with more complex dendritic arborization generally receive synaptic input from commensurately larger numbers of preganglionic axons. The axons of individually labelled cells give rise to varicose terminals in the iris and ciliary body; in most cases a single parent axon branches only after entering the iris, producing a network of terminals in the region of both the sphincter and the antagonist dilator muscle. Cells with both simple and complex dendritic geometry show this pattern of axonal arborization. The usual net effect of stimulating a single ciliary ganglion neurone through an intracellular electrode is constriction of the pupil. Since the terminals of individual ciliary ganglion neurones are commonly distributed to both the sphincter and dilator regions of the iris, impulses invading the terminals of a single ciliary neurone cause a contraction of the sphincter muscle, perhaps accompanied by a simultaneous relaxation of the dilator. Direct examination of individually labelled neurone has revealed details of the pattern of parasympathetic axon distribution to the iris, thus accounting for the origin of cholinergic terminals in the dilator, classically considered to be primarily a target of adrenergic sympathetic neurones.

Use of P NMR to Assess Effects of DNP on ATP Levels in Vivo in Barley Roots

Previous work has shown that undissociated 2,4-dinitrophenol (DNP) both increases the permeability of roots to ions and alters the membrane lipids of barley roots. Anionic DNP is the main entrant form but has no effect on permeability or on the membrane lipids. The amount of anionic DNP taken up by the roots is sufficient, that were it in free solution in the cytoplasm, the DNP would uncouple oxidative phosphorylation, and thereby inhibit ATP synthesis. The present work was undertaken to assess whether DNP alters ATP levels when it is taken up by barley roots. (31)P nuclear magnetic resonance spectra were used to monitor, in vivo, levels of ATP, cytoplasmic phosphate, vacuolar phosphate, and other phosphate compounds in barley roots in the presence of 10 micromolar DNP at pH 5 and pH 7. The spectra indicate that no change in the level of ATP or the cytoplasmic pH occurred in the roots in the presence of DNP for as long as 20 hours. Thus, the effects of undissociated DNP are effects directly on the root membranes and do not involve inhibition of ATP synthesis. Furthermore, the results explain why anionic DNP has no effect on ion uptake and accumulation.

99mTc HMDP bone scanning in generalised nodal osteoarthritis. II. The four hour bone scan image predicts radiographic change

In 14 patients with generalised nodal osteoarthritis a four hour bone scan image was found to predict the changes that occur on the radiograph at follow up between three and five years later. The scan abnormality appeared to precede the development of radiographic signs, and joints abnormal on scintigraphy showed most progression. Normal joints and joints abnormal on x ray alone showed little progression, and those that did subsequently alter became abnormal on scan. Scanning may provide a sensitive technique for monitoring osteoarthritis, it may enable a greater understanding of the underlying disease process, and allow evaluation of modifying therapeutic procedures.

99mTc HMDP bone scanning in generalised nodal osteoarthritis. I. Comparison of the standard radiograph and four hour bone scan image of the hand

The pattern of joint involvement on conventional radiographs and the four hour gammacamera image of 99Tc HMDP bone scans were studied in 33 patients with generalised nodal osteoarthritis. Both techniques showed the predominant involvement of the distal interphalangeal, scaphotrapezial, and first carpometacarpal joints. Some joints were abnormal just on one investigation: either x ray or scan alone. Others showed a marked dissimilarity in the severity of involvement on x ray compared with scan. This discrepancy between x ray and scan suggests that the scan is imaging a different process than the radiograph and offers a different way of assessing change in osteoarthritis.

Normal electrical activity is not required for the formation of specific sensory-motor synapses

These studies sought to determine the role of stretch-evoked electrical activity in muscle sensory axons on the formation of specific monosynaptic connections made by these neurons onto spinal motoneurons. Normal activity was disrupted by tenotomy during the developmental stages that the central connections are made. The pattern of connections was normal, suggesting that normal activity is not required in this system for the formation of specific sensory-motor connections.

The reduction of inter- and intra-observer variability for defining regions of interest in nuclear medicine

The use of region-of-interest (ROI) techniques to quantify data obtained in radionuclide images is commonplace. However, the reproducibility of quantitation due to inter- and intra-observer variations using particular methods of deriving ROIs is often not appreciated. We examined such variations in the results obtained by four independent observers of varying experience using four methods of depicting a ROI about an organ. The set of image data consisted of renal scans with varying target-to-background ratios, and the ROI facilities included two edge-detection methods. The results indicated that, once observers were experienced with edge-detection methods, a lower inter- and intra-observer variation could be achieved, although the technique of 'shrinking' a ROI about a subjectively chosen display level was reasonably satisfactory. In terms or reproducibility, the least satisfactory method of depicting a ROI was the commonly used manually guided 'bug' around arbitrarily chosen display levels representing the boundary of an organ.

Compartmental analysis of cerebrospinal fluid transfer and absorption in simulated hydrocephalus

A mathematical model of the cerebrospinal fluid (CSF) flow dynamics found in hydrocephalic infants with myelomeningocele lesions was constructed using criteria obtained from analogous clinical situations where 125I-labelled and 131I-labelled ortho-iodobenzoyl-amino-acetic acid (hippuran) had been employed to measure CSF flow dynamics. The quantitative results from this study allowed clinical data to be assessed and the importance of various CSF transfer mechanisms to be discussed. Our mathematical model indicates that the majority of radiopharmaceutical passes from the cerebral reservoir (the ventricles) into the blood. Experimental evidence indicates that the principal mechanism responsible for this movement is the bulk flow of CSF between its sites of production in the choroid plexus and absorption by the arachnoid villi.

Oesophageal function in diabetes mellitus and its association with autonomic neuropathy

We have evaluated oesophageal function in 34 diabetics and in 16 non-diabetic controls by a timed bolus transit method derived from dynamic oesophageal scintiscans (water transit time: WTT) and barium swallow. The diabetics were screened for autonomic neuropathy using standard cardiovascular responses and 10 patients were classified as abnormal. WTT was significantly prolonged in autonomic neuropaths compared with other diabetics (p less than 0.01) and controls (p less than 0.001). Abnormal peristalsis on barium swallow was seen more frequently in autonomic neuropaths (9/10) than in other diabetics (11/24, p less than 0.002). WTTs from all diabetic patients correlated with abnormal heart rate responses at rest (Rs = - 0.49, p less than 0.005), on deep inspiration (Rs = -0.48, p less than 0.005), and on standing (Rs = -0.39, p less than 0.025) but not with the Valsalva manoeuvre. A weaker correlation was found between the postural fall in blood pressure (Rs = 0.3, p less than 0.05). Diabetics with autonomic neuropathy frequently have asymptomatic oesophageal dysfunction which may result from a vagal neuropathy in view of its association with abnormalities of vagally mediated cardiovascular responses.

Radionuclide imaging of ovarian tumours with a radiolabelled (123I) monoclonal antibody (NDOG2)

The biodistribution of a radiolabelled monoclonal antibody (123I-NDOG2) was studied in patients with ovarian tumour. It was found that the uptake patterns in known tumour sites was variable and that the clearance of the agent from the vascular pool was due to renal excretion of the radionuclide and the redistribution of the radioactively labelled compound into other compartments. The mean (+/- SD) plasma clearance time was 20.8 (+/- 2.3) h and the ratios of target (tumour) to background (thigh) ranged between 1.4 and 4.8. The ratio between the plasma radioactivity at either 3.5 or 20 h after administration was calculated relative to the initial plasma radioactivity. These values (0.79 and 0.48, respectively) were incorporated into an image-subtraction technique that allowed for redistribution outside the vascular pool. A whole-body dose equivalent to 16.3 mu Sv MBq-1 (60.4 mrem.mCi-1) was calculated.

Radionuclide imaging of ovarian tumours with 123I-labelled monoclonal antibody (NDOG2) directed against placental alkaline phosphatase

A radiolabelled monoclonal antibody (NDOG2) directed against placental alkaline phosphatase (PLAP) was used in the radio-immunodetection of ovarian carcinoma. Tumour deposits were successfully visualized in 11 of 15 patients and the abnormalities demonstrated were classified as focal or diffuse. Of the 11 patients, eight showed focal abnormalities alone and three had a diffuse abnormality, of which two also showed a focal abnormality. False-positive results may occur not only due to uptake of 123I by gut mucosa and an inadequately blocked thyroid gland but also from activity in an incompletely emptied bladder. A false-negative result occurred due to high background activity in the liver masking a known, discrete tumour deposit.

The potential of phase and amplitude images in determining the boundary of the left ventricle

The phase and amplitude images derived from multiple gated blood pool studies of the heart have been used to aid the delineation of the boundary of the left ventricle. The results of left ventricular ejection fraction (LVEF) using this method have been compared with those obtained using edge detection algorithms, dual region of interest techniques, and x-ray contrast ventriculography, in a series of patients with well documented left ventricular wall motion. The results indicate that the sole use of phase and amplitude images does not improve the correlation or accuracy of LVEF estimation in relation to those obtained by x-ray contrast ventriculography, and that the dual region of interest technique is likely to remain the preferred method.

Anesthetics alter the lipid composition of barley-root membranes

The question of whether membrane expansion, which is caused by anesthetics in animal systems, alters the lipid composition of plant cell membranes was investigated. We have measured the effects of several anesthetics on the relative amounts of the principal fatty acids from the polar lipids of barley (Hordeum vulgare L.) root membranes. Procaine, dibucaine, tetracaine, chloroform and, to a lesser degree, methanol increased the proportions of palmitic, stearic and oleic acids and decreased the proportions of linoleic and linolenic acids. Ethanol had no significant effect. Total amounts of the fatty acids from the polar lipids of roots in procaine solution decreased markedly so that all of the acids decreased in amount. The anesthetic was effective as soon as the roots were introduced to the solution and the changes progressed at constant rates for 6 h. Only the polar membrane lipids were altered; other lipids were not affected. Increased hydrostatic pressure of about 1.0 MPa largely prevented the anesthetic effects, including the decrease in the total amounts of the fatty acids. Hydrostatic pressure as high as 2 MPa had no effect per se on the membrane lipid composition. These results indicate that anesthetics cause expansion of the root membranes which results in the lipid changes. That a compositional change in the membrane lipids involves a conformational change such as expansion is an indication of the nature of the link between changes in the membrane lipids and changes in function of areas where hydrophilic ions permeate.