The impact of consultant-delivered multidisciplinary inpatient medical care on patient outcomes

Consultant-delivered care has been shown to improve outcomes for acute medical patients. However, the ideal composition of a medical team to support consultant-delivered care is not clear and little is known about the effect of continuing consultant-delivered care until the patient is discharged. Between December 2011 and April 2012, 260 general medical patients requiring inpatient care were managed by a consultant-delivered multidisciplinary team (CD-MDT) and 150 patients by a standard consultant-led team of trainee doctors. The length of hospital stay was significantly lower for patients managed by a CD-MDT than for those managed by a standard team (4-5 days vs 7 days, p<0.001). No difference between the groups was seen for readmission rates, patient safety or mortality. In conclusion, a CD-MDT is a safe and effective model of inpatient medical care and is associated with a shorter length of hospital stay.

Electrocardiographic abnormalities in a patient with subarachnoid haemorrhage

A 69-year-old woman presented after collapsing. She denied chest pain, breathlessness or headache. She was afebrile and vital signs were unremarkable. She was confused but the remaining physical examination was unremarkable. Routine blood tests were unremarkable. Cardiac enzymes were raised with a troponin I of 0.54. ECG showed Q waves in leads V1-V3 and widespread T wave inversion in leads II, III, aVF and V1-V6. Acute coronary syndrome (ACS) was suspected and antiplatelet treatment started. The following day her confusion worsened. Further review of the ECG found extensive changes unexplained by occlusion of a single artery suggesting extra-cardiac pathology. An urgent CT head was arranged and revealed subarachnoid haemorrhage. ACS treatment was stopped and she was transferred to neurosurgery where her right posterior communicating artery aneurysm was coiled. Fortunately her recovery was uneventful and she was discharged home with no neurological impairment.

Phase reversal of vibratory signals in honeycomb may assist dancing honeybees to attract their audience

Forager honeybees dancing on the comb are able to attract dance-followers from distances across the comb that are too remote for tactile or visual signals to play a role. An alternative signal could be the vibrations of the comb at 200–300 Hz generated by dancing bees but which, without amplification, may not be large enough to alert remote dance-followers. We describe here, however, an unexpected property of honeycomb when it is subjected to vibration at around 200 Hz that would represent an effective amplification of the vibratory signals for remote dance-followers. We find that, at a specific distance from the origin of an imposed vibration, the walls across a single comb cell abruptly reverse the phase of their displacement and move in opposite directions to one another. Behavioural measurements show that the distance from which the majority of remote dance-followers are recruited coincides with the location of this phase-reversal phenomenon relative to the signal source. We propose that effective signal amplification by the phase-reversal phenomenon occurs when bees straddle a cell across which the phase reversal is expressed. Such a bee would be subjected to a situation in which the legs were moving towards and away from one another instead of in the same direction. In this manner, remote dance-followers could be alerted to a dancer performing in their vicinity.

"Impoverished" and "enriched" living conditions influence the proliferation and survival of neurons in crayfish brain

New neurons are added to two bilateral clusters of neurons in crayfish brain throughout their lives. These interneurons are associated with the olfactory and accessory lobes, areas of the brain that receive primary olfactory information and higher order inputs from the visual and tactile receptor systems. The rate of cell proliferation in these four clusters, revealed by BrdU labeling, is sensitive to the living conditions of the animals: individuals isolated in small spaces (impoverished condition) exhibit a lower rate of cell proliferation in comparison to their siblings living together in larger areas (enriched condition), although both groups were fed to satiation. Reduction in the rate of proliferation can be measured 1 to 2 weeks after the animals are subjected to the impoverished condition. Counts of the labeled neurons that survive after 4 weeks of subjection to the two conditions show that fewer new neurons survive in the brains of animals that have lived for 2 weeks in the impoverished condition in comparison to their siblings living in the enriched conditions. Factors such as surface area, depth of water, and social interaction can all play a role in determining both the rate of new neuron production and the incorporation of the new neurons into the brain of freshwater crayfish. The results indicate a high degree of neuronal plasticity in the crayfish brain that is highly sensitive to the conditions under which the animals are kept.

A simple trajectory guidance device that assists freehand and interactive image guided biopsy of small deep intracranial targets

Frameless image guided stereotactic systems are rapidly becoming incorporated into routine neurosurgical practice. In our unit, the Elekta Viewing Wand has been applied to a comprehensive range of neurosurgical procedures, including pituitary, posterior fossa, skull base, atlantoaxial, and epilepsy surgery. The system allows a minimally invasive surgical exposure and provides instant and continual navigational information during surgery. Subjective studies have shown this intraoperative information to facilitate the surgeon's perception of anatomic relations and identification of structures, thus improving surgical safety. Furthermore, in comparison to traditional stereotactic frames, the frameless system has been reported to reduce operative time. The technology involves the use of a localizing mechanical arm to which a pointer or biopsy probe is attached. This localizing arm is hand-held and is therefore only as steady as the surgeon's hand. This precludes the use of the Viewing Wand for functional procedures and for the safe biopsy of small, deep-seated intracranial lesions. Both types of procedures are very dependent on a steady linear approach to the target for a successful outcome. We have designed a simple guidance device that eliminates the risk of unwanted drift or angular movements of the probe as it is advanced toward the target. When used with the Viewing Wand, this device guides the wand biopsy probe along a predetermined, fixed linear trajectory to the intracranial target. We report the successful use of the fixed trajectory guidance device (FTGD) with the Elekta Viewing Wand in a series of 12 patients.

Central complex in the brain of crayfish and its possible homology with that of insects

A small, medial heterolateral neuropil in the brain of crustaceans has long been regarded as the central body of the crustacean brain. Its simplicity and the absence of clear layers within its neuropil have led to the question of its homology with the more complex central body that occupies an approximately equivalent position in the brain of insects. We have labelled neurons in the central body of the Australian freshwater crayfish Cherax destructor by the extracellular application of dextrans and by treating the brain with antibodies to anti-CCAP, anti-locustatachykinin, anti-perisulfakinin, anti-proctolin, anti-dip-allatostatin AI, anti-PEA-head-peptide, anti-serotonin, and anti-rabbit anti-substance P, all of which label neurons in the insect brain. The dextran and immunocytochemical labelling have revealed a neural complex associated with the crayfish central body that is very similar in overall anatomical architecture to the subset of neuropils that are incorporated in the central complex of the insects, and in particular to that of the locust. Similarities between the crayfish and locust central complexes extend to the number and position of the neuropils, the location of the cell body clusters of the neurons that belong to the central complex, the numbers of tracts that link some of the constituent neuropils together, and the form and immunoreactivity of many of the individual neuron classes. These similarities are taken as evidence to support a possible homology between the crustacean central complex and that of the insects.

Homology and convergence in vertebrate and invertebrate nervous systems

Each year the meeting of the American Neuroscience Society attracts over 20,000 members, reflecting the explosion of interest in this field that has occurred over the past few decades. Researchers from many disciplines are focusing their skills on the investigation of every aspect of nervous systems, and neuroscience now encompasses the entire range of endeavour from the study of the single molecules that make up neural membranes to the non-invasive observation of neural function in animals behaving in their natural environments. Advances over the past three decades in our understanding of nervous systems are impressive and come from a multifaceted approach to the study of both vertebrate and invertebrate animals. An almost unexpected by-product of the parallel investigation of vertebrate and invertebrate nervous systems that is explored in this article is the emergent view of an intricate web of evolutionary homology and convergence exhibited in the structure and function of the nervous systems of these two large, paraphyletic groups of animals.

Interactive image-guided pituitary surgery. An experience of 101 procedures

This paper reports on a series of 101 pituitary region operations performed using image guidance technology in the Department of Neurosurgery, Frenchay hospital, Bristol, UK between 1992-1997. The cases form part of an overall series of image guided surgery of 1,112 cases performed during that time. The systems used were the ISG/Elekta Viewing Wand and the Sofamor Danek StealthStation. Thirty-five tumors had a diameter of > 2.5 cm and 12 > 5 cm. The clinical indications for surgery were: visual failure (n = 47), acromegaly (n = 22). Cushing syndrome (n = 6), hyperprolactinemia (n = 1), hyposecretion syndromes (n = 8), raised intracranial pressure/CSF leak (n = 13). Three cases were operated on because of radiological evidence of tumor progression without symptoms. Eighty-five patients had skull base procedures (56 transnasal routes, 16 transsphenoidal approaches, 13 sphenoid fenestrations), 16 underwent craniotomy. Operating times and postoperative bed stay were shortest the more minimally invasive the procedure. Sixty-eight percent of patients presenting with visual failure improved postoperatively. Surgery produced biochemical "cure" in 41% of patients with hypersecretion syndromes. Fifty percent of patients with hypopituitary syndromes improved endocrinologically postoperatively. Twenty-five complications were noted: 9 rhinorrheas, 5 diabetes insipidus, 3 postoperative epilepsies, 3 induced visual deteriorations and pituitary insufficiency. There were 2 deaths. Image guidance technology is applicable to pituitary surgery, particularly in four situations: i) orientation in difficult skull base approaches e.g. reoperations, paediatric cases, non pneumatised sphenoid, microadenomas, carotid arteries medially placed, ii) in craniotomies to customize the surgical approach, locate different parts of a tumor and identify critical anatomy related to the tumor, iii) in the planning and execution of minimally invasive approaches to the pituitary fossa (sphenoid fenestration, transnasal approach), iii) endoscopy.

Growth-related and antennular amputation-induced changes in the olfactory centers of crayfish brain

Freshwater crayfish increase in size throughout their lives, and this growth is accompanied by an increase in the length of the appendages and number of mechanoreceptive and chemoreceptive sensilla on them. We find that in the Australian freshwater crayfish Cherax destructor, neuropil volumes of the olfactory centers increase linearly with body size over the entire size range of animals found in their natural habitat. The number of cell somata of two groups of interneurons associated with the olfactory centers (projection neurons and small local neurons) also increases linearly with the size of the animals. In contrast, axon counts of interneurons that represent a nonolfactory input to the olfactory centers show that these reach a total number in the very early adult stages that then remains constant regardless of the size of the animal. Only the axon diameter of these interneurons increases linearly with body size. Amputation of the antennule and olfactory sensilla reduces the number of projection and local interneurons on the amputated side. No change in the size of the olfactory centers occurs on the unamputated side. Amputation of the olfactory receptor neurons in crayfish therefore leads not only to a degeneration of the receptor cell endings in the olfactory lobe but also to a trans-synaptic response in which the number of higher order neurons decreases. Reconstitution of the antennule and olfactory receptor neurons in small adult crayfish is accompanied by the reestablishment of the normal number of interneurons and neuropil volume in the olfactory centers.

Orthodromically and antidromically evoked local field potentials in the crayfish olfactory lobe

A local field potential, consistent in form and duration, can be recorded from the olfactory lobe of crayfish following electrical stimulation of the outer flagellum of the antennule. The field potential is reversibly blocked by perfusion of the brain with low-[Ca2+] saline or &lt;IMG src="/images/symbols/gamma.gif" WIDTH="9" HEIGHT="12" ALIGN="BOTTOM" NATURALSIZEFLAG="3"&gt;-aminobutyric acid and, to a lesser extent, histamine. Paired shocks to the antennule and antidromic electrical stimulation of olfactory lobe output neurones also partially block the field potential. Comparing the field potential with simultaneously recorded intracellular responses of olfactory interneurones reveals a coincidence between excitatory and inhibitory effects in the interneurones and the appearance of identifiable components of the field potential. We interpret the field potential to reflect the response of neural elements in the olfactory lobe to orthodromic activity in the axons of the olfactory receptor neurones on the antennule. We conclude from the blocking experiments that the greater part of the field potential stems from neurones in the olfactory lobe that are postsynaptic to olfactory receptor neurones. As such, it provides a robust indication of olfactory neurone activity.

Effect of replacement doses of thyroxine on bone mineral density

INTRODUCTION

Hyperthyroidism is associated with a reduction in bone mineral density (BMD). Suppressive doses of thyroxine (T4), inducing subclinical hyperthyroidism, have been reported by some investigators to reduce BMD. Little work has been done on replacement doses of T4.

AIM

The aim was to investigate the effect of replacement doses of T4 on BMD.

STUDY DESIGN

Cross-sectional study of hypothyroid patients on long-term T4 replacement doses, comparing those who had primary hypothyroidism with those who were previously hyperthyroid.

PATIENTS

Fifty women on replacement doses of T4 for more than 5 years were recruited. Twenty-five were treated for primary (group 1) and 25 for radioiodine-induced hypothyroidism (group 2). They were well matched for age, menstrual status, smoking history, body mass index (BMI), dose and duration of T4 replacement as well as thyroid status.

MEASUREMENTS

BMD was assessed by dual energy X-ray absorptiometry. Free T4 (FT4), FT3 as well as ultrasensitive TSH assays were used to assess thyroid status.

RESULTS

The two groups showed no difference in BMD (g/cm2) of the lumbar spine (1.008 vs. 0.957, P = 0.25), femoral neck (0.745 vs. 0.735, P = 0.79) and total hip (0.878 vs. 0.837, P = 0.24). When the two groups were pooled, there was no significant difference between the patients and a reference population with femoral neck and total hip BMD expressed as a standard deviation (Z) score. However, the lumbar spine mean Z score was significantly greater than zero. For each site, there was a negative correlation of BMD with age in at least one group but, in general, BMI, FT4, FT3 and duration of T4 replacement did not correlate with BMD. T4 dose, however, had a consistent positive correlation with BMD in the spine, femoral neck and the hip (P = 0.01, 0.04 and 0.02, respectively) in group 2 but not group 1.

CONCLUSION

In this study, there is no evidence for a difference in bone mineral density in patients receiving replacement doses of thyroxine irrespective of the aetiology of their hypothyroidism. The reduced bone mineral density associated with hyperthyroidism appears to be restored, maintained and in some cases possibly improved while on long-term thyroxine replacement post-radioiodine.

Fetal growth and insulin resistance in adult life: role of skeletal muscle morphology

1. Thinness at birth is associated with insulin resistance in adult life and an apparent delay in activation of glycolysis/glycogenolysis in exercising skeletal muscle. As developmental abnormalities of skeletal muscle histology or metabolism may explain this association we examined muscle histology, biochemistry and blood flow in a group of 27 adult women whose birth details were known. 2. Subjects were examined by near-infrared spectroscopy to determine forearm muscle oxygen supply, and by muscle biopsy and forearm plethysmography. Those with a ponderal index at birth < 23 kg/m3 were insulin resistant (assessed by the short insulin-tolerance test-mean rate constants for glucose disappearance = 4.14 compared with 4.83%/min, P = 0.045) and had significantly more rapid muscle reoxygenation than the remainder of the subjects (13 compared with 22 s, P = 0.004). 3. Thinness at birth did not influence muscle capillary density, muscle glycogen content, glycogen synthase activity, citrate synthase activity or resting forearm blood flow. 4. Insulin resistance seen after fetal malnutrition was not associated with abnormal muscle histology, resting muscle blood flow, mitochondrial volume or glycogen content. 5. The increase in muscle reoxygenation rate in adult subjects who were thin at birth could occur to promote oxidative ATP synthesis in compensation for the delay in activation of glycolysis/glycogenolysis. It suggests altered regulation rather than structure of the muscle microcirculation. These changes appear to antedate the structural and biochemical changes seen in muscle from patients with established diabetes.

Transmission of vibration across honeycombs and its detection by bee leg receptors

Vibration of the rims of open cells in a honeycomb, applied in the plane of the comb face, is transmitted across the comb. Attenuation or amplification of the vibratory signal depends on its frequency and on the type of comb. In general, framed combs, both large and small, strongly attenuate higher frequencies, whereas these are amplified in small open combs. The very poor transmission properties of the large framed combs used in commercial hives may explain the bees' habit of freeing an area of comb from the frame in those areas used for dancing. Extracellular electrical recordings from the leg of a honeybee detect large action potentials from receptors that monitor extension of the tibia on the femur. Measurements of threshold displacement amplitudes show these receptors to be sensitive to low frequencies. The amplification properties of unframed combs extend the range of these receptor systems to include frequencies that are emitted by the bee during its dance, namely the 15 Hz abdomen waggle and 250 Hz thorax vibration.

Pre- and postembryonic development, growth and turnover of olfactory receptor neurones in crayfish antennules

The antennules of the crayfish Cherax destructor can first be observed as antero-laterally located lobes in embryos that have reached the 50 % stage of development. Clusters of cells that are probably the olfactory receptor neurones (ORNs) appear at the distal end of these lobes, which later differentiate into the lateral flagella of the antennules. New clusters of ORNs and segments are added at the proximal end of the lateral flagellum throughout the postembryonic stages and well into the juvenile adult stage. From a comparison of the exuvia and the newly emerged flagella in animals over a wide range of sizes, we conclude that, once the animals reach a certain size (approximately 7 mm carapace length), the most distal, and oldest, segments of the antennule are shed. Growth occurs from the proximal end of the flagellum, and the addition of new ORNs is the result of a delayed differentiation of the flagellar segments that takes place at the proximal end of the chemoreceptor array, about halfway along the flagellum.

Crayfish brain interneurons that converge with serotonin giant cells in accessory lobe glomeruli

Freshwater crayfish have well-developed olfactory systems with an array of receptors that project exclusively to areas in the brain that are functionally specialized for the processing of odors. The accessory lobes are large bilateral areas of neuropil that are anatomically associated with the olfactory lobes. The accessory lobes receive no primary afferents and do not contain the endings of motor efferents; thus, their role in olfaction is still obscure. Intracellular dye filling of interneurons in the deutocerebral commissure in the crayfish brain has shown that they end bilaterally in glomeruli in the accessory lobes, have cell somata in a dorsal cluster medial to the olfactory lobes, and have unilateral projections to the deutocerebral commissure neuropil. Each deutocerebral commissure interneuron has only 6 to 15 output glomeruli in each accessory lobe and does not share glomeruli with other deutocerebral commissure interneurons. The deutocerebral commissure interneurons converge with the dorsal giant serotonin neurons in the accessory lobe glomeruli. Deutocerebral commissure interneurons can be separated into classes according to their projections to the protocerebrum, central body, and deutocerebrum. Physiological responses of the deutocerebral commissure interneurons following photic stimulation of the eyes and electrical stimulation of the second antennae lead to the conclusion that the deutocerebral commissure represents an input to the accessory lobes from the protocerebral neuropils and that visual and tactile inputs are included in the processing performed in the accessory lobes.

A pilot study of the treatment of patients with recurrent malignant gliomas with intratumoral yttrium-90 radioimmunoconjugates

A pilot study of the treatment of patients with relapsed malignant gliomas with direct intratumoral injections of yttrium-90 (90Y) radioimmunoconjugates has been completed. Patients were recruited following maximal tumour resection, and received 1-3 injections of 90Y conjugated to a monoclonal antibody designated ERIC-1, which binds the neural cell-adhesion molecule. Data were collected to establish clinical toxicity, pharmacokinetics and radiation doses to the cavity wall and critical body organs. Twenty-three injections were completed in 15 patients, with a mean injected activity of 675 MBq (range 399-921). Early toxicity manifested as cerebral oedema and was readily controlled with dexamethasone. Delayed myelosuppression was observed but no intervention was required. Pharmacokinetic analysis confirmed prolonged retention of isotope in the cavity with correspondingly low activity in the bloodstream. These data were translated into estimates of absorbed radiation dose using the Medical Internal Radiation Dosimetry (MIRD) scheme. Mean doses, and dose rates, to the wall of the cavity, i.e. 'tumour,' were very high in comparison to normal tissue doses, with a further advantage if targeting was achieved.

Comparative brain ontogeny of the crayfish and clawed lobster: implications of direct and larval development

The freshwater crayfish Cherax destructor and the lobster Homarus americanus have many similarities including life style, body form, and neural organization. However, the ontogenic history is very different in the two species. The development of Cherax is short and direct whereas the development of Homarus comprises three pelagic larval stages and takes more than twice as long from extrusion to benthic stages at constant temperature. In order to determine the progression of maturation of the nervous system in each species and the potential implications of pelagic forms on brain structure, the timing of appearance of 22 general and neural developmental events clearly identifiable in both species was compared. The onset of serotonin antigenicity in the different parts of the brain was chosen as one marker of neural development. During the first month of embryogenesis the timing of morphological, physiological, and neural events is similar in the two species. Morphological development is then accelerated in the crayfish near hatching time and over the two postembryonic stages before the advent of the independent benthic stage. Such heterochronic processes can at least partly account for the different developmental patterns in the two decapods. Among the characters showing similar timing in the two species is the formation of glomeruli (presumptive zones of synaptic contact) in the olfactory lobes of the deutocerebrum, although this event is embryonic in Homarus but postembryonic in Cherax. In contrast, glomerular formation in the accessory lobes is heterochronic: in both species, the glomeruli of the accessory lobes are acquired postembryonically, that is, 3 to 4 months earlier in Cherax than in Homarus. These data suggest that the development of the glomeruli in the olfactory lobes may depend primarily on internal developmental signals, whereas the triggering of glomerular formation in the accessory lobes may depend on external cues. The fact that, in Homarus, only the postlarval stages show mature accessory glomeruli may be a reflection of the functional requirements of benthic life.

Coming of age with diabetes: patients' views of a clinic for under-25 year olds

This study is both an evaluation of patients' perceptions of a diabetes clinic for under-25 year olds, and an assessment of experiences in transferring from a paediatric clinic. Sixty-nine patients with Type 1 diabetes (74% of the total clinic), including 41 females, completed evaluations of the clinic and recall of experiences in transfer. Mean age on transferring clinic was 15.9 (range 12-20) years. Paediatricians were perceived to emphasise family and social life, school or work progress; adult physicians tended to stress the risk of long-term complications, importance of exercise and need to maintain strict levels of glycaemic control. Our data suggest that transition to adult care can generally be achieved non-traumatically, but patients may perceive some difficulty because of different emphases and treatment advice favoured by paediatricians and adult physicians.

Morphology of the Brain of Crayfish, Crabs, and Spiny Lobsters: A Common Nomenclature for Homologous Structures

The morphologies of the cerebral ganglia (brains) of three infraorders of the decapod crustaceans (Astacura-crayfish; Brachyura-crabs; Palinura-spiny lobsters) are described. A common nomenclature is proposed for homologous nerve roots, brain regions, tracts, commissures, neuropils, and cell body clusters.

Quality of life in young adults with type 1 diabetes in relation to demographic and disease variables

Sixty-nine young adults (mean age 21 (range 15-25) years) with Type 1 diabetes completed measures of diabetes knowledge and quality of life. Factor analysis of the quality of life scale resulted in the identification of three subscales (social relationships, diabetes concerns, and impact). There was no relation between any of the quality of life subscales with knowledge, or with multiple versus twice-daily insulin injection regimens. Higher self-rated diabetes satisfaction was related to lower fructosamine levels and better clinic attendance (p less than 0.05). Females reported a more negative impact of diabetes on their lives compared with males (p less than 0.05).

Tactile localisation: the function of active antennal movements in the crayfish Cherax destructor

Video recordings and single frame analysis were used to study the function of the second antennae of crayfish (Cherax destructor) as a sensory system in freely behaving animals. Walking crayfish move their antennae back and forth through horizontal angles of 100 degrees and more, relative to the body long axis. At rest, animals tend to hold their antennae at angular positions between 20 and 50 degrees. Movements of the two antennae are largely independent of each other. Before and during a turn of the body the ipsilateral antenna is moved into the direction of the turn. Solid objects are explored by repeatedly moving the antennae towards and across them. Both seeing and blinded crayfish can locate stationary objects following antennal contact. On antennal contact with a small novel object, a moving animal withdraws its antenna and attacks the object. When the antenna of a blinded crayfish is lightly touched with a brush the animal turns and attacks the point of stimulation. The direction taken and the distance covered during an attack can be correlated with: the angle at which the antenna is held at the moment of contact and the distance along the antennal flagellum at which the stimulus is applied. From behavioural evidence we conclude that crayfish use information about the angular position of their antennae and about the position of stimulated mechanoreceptors along the antennal flagellum to locate objects in their environment. We suggest ways in which an active tactile system-like the crayfish's antennae--could supply animals with information about the three-dimensional layout of their environment.

The value of an erect abdominal radiograph in the diagnosis of intestinal obstruction

The value of an erect abdominal radiograph in the diagnosis of acute intestinal obstruction has been studied. Four observers independently assessed 100 supine abdominal films and then reassessed them in combination with an erect film. The addition of the erect film did not significantly increase the accuracy of diagnosis of obstruction or help in the correct identification of its level. The presence or absence of gas in the rectum was of no diagnostic value.