Improved estimation of human cortical activity and connectivity with the multimodal integration of neuroelectric and hemodynamic data

In the last decade, the possibility to noninvasively estimate cortical activity and connectivity has been highlighted by the application of the techniques known as high resolution EEG. These techniques include a subject's multi-compartment head model (scalp, skull, dura mater, cortex) constructed from individual magnetic resonance images, multi-dipole source model, and regularized linear inverse source estimates of cortical current density. More recently, it has proved as the use of information from the hemodynamic responses of the cortical areas as revealed by block-designed (strength of activated voxels) fMRI improves dramatically the estimates of cortical activity and connectivity. Here, we present some applications of such estimation in two set of high resolution EEG and fMRI data, related to the motor (finger tapping) and cognitive (Stroop) tasks. We observed that the proposed technology was able to unveil the direction of the information flow between the cortical regions of interest.

Estrous cycle characterisation and artificial insemination using frozen–thawed spermatozoa in the bottlenose dolphin (Tursiops truncatus)

The reproductive endocrinology of the bottlenose dolphin,Tursiops truncatus,was characterized to facilitate the development of artificial insemination using cryopreserved spermatozoa. Specific objectives were: (i) to determine the excretory dynamics of urinary luteinizing hormone (LH) and ovarian steroid metabolites during the estrous cycle; (ii) to evaluate the effect of an exogenously administered synthetic progesterone analog (altrenogest) on reproductive hormone excretion; (iii) to correlate follicular growth and ovulation (as determined by transabdominal ultrasound) to urinary LH and ovarian steroid metabolites; (iv) examine thein vivofertilisation capacity of cryopreserved semen, and (v) to develop an intrauterine insemination technique. Based on urinary endocrine monitoring of natural estrous cycles (2 consecutive cycles) and nine post altrenogest cycles in ten females, estrous cycles were found to be 36 days long and comprised of an 8 day and 19 day follicular and luteal phase, respectively. Peak estrogen conjugates (EC; 5.4 ± 3.8 ng/mg creatinine (Cr)) occurred 8 h prior to the LH surge (70.9 ± 115.7 ng/mg Cr). The time of ovulation, as determined by ultrasonography, occurred 32.1 ± 8.9 h and 24.3 ± 7.0 h after the onset of the LH surge and LH peak, respectively. Mean preovulatory follicular diameter and circumference were 2.1 ± 0.5 cm and 6.5 ± 1.5 cm, respectively. Of the 27 estrous synchronisation attempts, 13 resulted in an ovulatory cycle, with ovulation occurring 21 days post-altrenogest treatment. Intrauterine (4 of 5) and intracornual (1 of 3) inseminations conducted across eight estrous cycles resulted in five pregnancies (63%), one pregnancy resulted from the use of liquid stored semen, whereas four were achieved using cryopreserved semen. These data provide new information on female bottlenose dolphin reproductive physiology, and demonstrate that the combination of endocrine monitoring and serial ultrasonography contributed to successful AI using liquid-stored and cryopreserved semen.

Estimation of the cortical functional connectivity with the multimodal integration of high-resolution EEG and fMRI data by directed transfer function

Nowadays, several types of brain imaging device are available to provide images of the functional activity of the cerebral cortex based on hemodynamic, metabolic, or electromagnetic measurements. However, static images of brain regions activated during particular tasks do not convey the information of how these regions communicate with each other. In this study, advanced methods for the estimation of cortical connectivity from combined high-resolution electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) data are presented. These methods include a subject's multicompartment head model (scalp, skull, dura mater, cortex) constructed from individual magnetic resonance images, multidipole source model, and regularized linear inverse source estimates of cortical current density. Determination of the priors in the resolution of the linear inverse problem was performed with the use of information from the hemodynamic responses of the cortical areas as revealed by block-designed (strength of activated voxels) fMRI. We estimate functional cortical connectivity by computing the directed transfer function (DTF) on the estimated cortical current density waveforms in regions of interest (ROIs) on the modeled cortical mantle. The proposed method was able to unveil the direction of the information flow between the cortical regions of interest, as it is directional in nature. Furthermore, this method allows to detect changes in the time course of information flow between cortical regions in different frequency bands. The reliability of these techniques was further demonstrated by elaboration of high-resolution EEG and fMRI signals collected during visually triggered finger movements in four healthy subjects. Connectivity patterns estimated for this task reveal an involvement of right parietal and bilateral premotor and prefrontal cortical areas. This cortical region involvement resembles that revealed in previous studies where visually triggered finger movements were analyzed with the use of separate EEG or fMRI measurements.

Theoretical and finite-element investigation of the mechanical response of spinodal structures

In recent years there have been major advances in our understanding of the mechanisms of phase separation in polymer and copolymer blends, to the extent that good control of phase-separated morphology is a real possibility. Many groups are studying the computational simulation of polymer phase separation. In the light of this, we are exploring methods which will give insight into the mechanical response of multiphase polymers. We present preliminary results from a process which allows the production of a two-dimensional finite-element mesh from the contouring of simulated composition data. We examine the stretching of two-phase structures obtained from a simulation of linear Cahn-Hilliard spinodal phase separation. In the simulations, we assume one phase to be hard, and the other soft, such that the shear modulus ratio G is large (>or= 10(3)). We indicate the effect of varying composition on the material modulus and on the distribution of strains through the stretched material. We also examine in some detail the symmetric structures obtained at 50% composition, in which both phases are at a percolation threshold. Inspired by simulation results for the deformation of these structures, we construct a "scaling" theory, which reproduces the main features of the deformation. Of particular interest is the emergence of a lengthscale, below which the deformation is non-affine. This length is proportional to G(1/4), and hence is still quite small for all reasonable values of this ratio. The same theory predicts that the effective composite modulus scales also as G(1/4), , which is supported by the simulations.

Mindful messages: surfing for spirituality

As it becomes clearer that spiritual concerns are very much part of the work of palliative care nurses, it is interesting to note the many ways in which patients express their needs and the different approaches adopted by carers in addressing them. This site, although not specific to palliative care, reflects many concerns familiar to those working with people whose illness may focus their thoughts on death or dying either at diagnosis, or as a longer-term source of distress.

Interpretations and variations of ISO 9000 in acute health care. International Organization for Standardization

OBJECTIVE

This paper aims to address two questions related to the implementation of the ISO 9000 Quality Management System standard in the acute health care sector: which countries have developed specific nationwide guidelines/interpretations? and what variances exist between the different interpretations of the ISO 9002 standard?

DESIGN

The study was carried out via an assessment of the available guideline documents for the use of ISO 9000 in the acute health care sector. The interpretation of each document was examined for common elements and deviations from the commonly agreed terms.

SETTING

Worldwide in the acute health care sector (excluding that of laboratories).

STUDY PARTICIPANTS

Eighty-two international ISO members and/or quality health care organizations.

RESULTS

The results showed variation in the interpretations of the ISO 9000 standard. In total, 16 of the clauses/subclauses note distinct variations, between one or more of the documents, which could alter the perception of the system.

CONCLUSION

From examination of the six identified guideline documents, the claim that ISO 9000 introduces quality systems which are comparable from one country to another is unfounded in the acute health care sector.

Male cancers: the great taboo

Linked as they are with taboos on age, sex and continence, it is perhaps no surprise that male cancers have not received the same exposure as, for instance, breast cancer. This is also the case on the Internet, which is often criticized for its male dominance. However, a growing number of efforts are being made to redress this balance.

Three words three shapes: A clinical test of memory

Three Words - Three Shapes was designed as an easy "bedside" test for elderly patients that assesses verbal and nonverbal memory within the same modality. In the present study, it was administered to patients with probable Alzheimer's disease (PRAD), a control group of non-demented older subjects (NC) and a group of patients with Korsakoff's amnesia (KA). Incidental recall and several other measures of learning, retention and recognition differentiated control from PRAD and KA subjects. PRAD and KA subjects' performance was similar, but there were some material-specific interactions. This test is relatively easy and some of the derived measures could prove useful in staging amnesia progression beyond the earliest stages of PRAD when more difficult tests yield floor effects.

Fatigue: online resources and advice

This site is a joint development by the Oncology Nursing Society and the Fatigue Coalition. Like many US sites, the content is also available in Spanish in order to reach the widest possible audience. The site allows the user to explore fatigue in detail, and includes information that patients may use to improve their ability to cope with this cancer symptom. For the professional, the site raises the challenge of considering fatigue in a new light; not just as an inevitable part of cancer, its treatment and progression but rather as a problem that needs to be addressed in a holistic fashion in much the same way as pain is.

Breast cancer: net gains for patients

Dominated by the pink ribbon logo now so clearly linked with breast cancer, this site offers a range of material and highlights the support services offered by this charity to the 1 in 11 women in the UK who develop the disease in any one year.

Paediatric palliative care comes of age

With its colourful layout and detailed explanations this site aims to raise the profile of children’s palliative care, which has emerged as a speciality in the last decade. Although some elements of this site remain under construction, if this area of nursing interests you then it is one for your hotlist.

User views of a regional secure unit--findings from a patient satisfaction survey

This paper includes key findings of a patient satisfaction survey, conducted within an English Medium Secure Unit, offering care and treatment for 45 male and female mentally disordered offenders. It aims to identify patients' perceptions of the quality of their care and other aspects of their lives within the secure unit. Following permission from the local Ethics Committee, two interviewers collected data within a two week period, using a semi-structured interview schedule. All but three of the respondents agreed to be interviewed. Talking to nurses was perceived as highly satisfying. However, provision for specific cultural and women's needs, facilities for visitors, opportunities to practise religious beliefs and access to care plans were highlighted as unsatisfactory. The study concludes with recommendations for improvement, some of which have already been considered and implemented.

Psychiatric comorbidity in methadone maintained patients

Diagnosing comorbid psychiatric disorders in methadone maintained patients may help to identify subgroups with different outcomes and needs for treatment. In this study, 75 methadone maintenance clinic patients in treatment longer than 30 days were assessed with the Addiction Severity Index, Global Assessment Scale and Mini-Mental Status Exam, and were interviewed for DSM-III-R psychiatric diagnosis using the computerized Diagnostic Interview Schedule. Psychiatric diagnoses were prevalent in the sample with depression, phobic disorders, antisocial personality and generalized anxiety the most common. Both number of DSM-III-R diagnoses and severity of psychopathology were correlated with outcome measures such as concurrent drug abuse, family-social problems and employment status.

Quality assurance and standards for red cells and platelets

Blood donations vary in composition because of considerable variation in donor cell counts and volume collected. In order to minimize the variation in end products produced, and reduce the likelihood of low quality products, a program called Quality Assurance (QA) is required. Agreement on minimal standards is useful, and a program of quality control (QC) is an important component of QA. However, while QC to ensure compliance with standards is desirable, the objective of manufacturing products of consistently high quality can only be achieved when attention is focused on total process control, self-auditing and the energetic management of errors.

Comparison of results of various methods used to determine the extent of modification of methoxy polyethylene glycol 5000-modified bovine cupri-zinc superoxide dismutase

The protein bovine cupri-zinc superoxide dismutase (SOD) was modified by the reaction of lysine residues with an active ester of methoxy polyethylene glycol 5000 (PEG). The extent of modification was determined by capillary zone electrophoresis, matrix-assisted laser desorption/ionization mass spectrometry, Fourier-transform infrared spectroscopy, and Raman spectroscopy and after removing PEG by alkaline hydrolysis of the linkages to SOD followed by quantification of the released PEG using gel-permeation chromatography. There was generally good agreement among the results obtained by these techniques on a typical sample of the PEG-modified protein. The results, extent of protein modification, determined by the preceding methods were compared to that found from the classical trinitrobenzene sulfonic acid (TNBS) procedure. In addition to providing alternatives to the TNBS procedure, results from the described methodologies strongly suggest that the extent of modification determined from the TNBS procedure is overestimated.

Combined PTCA and aortic valvuloplasty for acute myocardial infarction complicated by severe aortic stenosis and cardiogenic shock

Percutaneous aortic valvuloplasty (PAV) performed in patients with critical aortic stenosis has been shown to increase aortic valve area, decrease aortic valve gradient, and improve left ventricular function. However, the procedure is limited by rapid restenosis. Aortic valvuloplasty in the setting of critical aortic stenosis with cardiogenic shock can be a life-saving procedure, although morbidity and mortality remain high. We describe a patient with critical aortic stenosis who presented with an acute anterior myocardial infarction treated with primary angioplasty. Despite rapidly achieving patency of the culprit vessel, the patient spiraled into cardiogenic shock, which prompted an emergent PAV.

Identification of metallothionein receptors in human astrocytes

Metallothionein (MT) isoforms are low molecular weight (6000-7000 Da) zinc binding proteins containing 60-68 amino acid residues, 25-30% cysteine, no aromatic amino acids, and binding between 5-7 g zinc/mol of protein. Since the synthesis of MT is induced by endotoxin, cytokines, and glucocorticoids, MT is now considered to be an acute phase protein protecting against oxygen radicals and oxidative damages caused by inflammation, tissue injury, and stress to the central nervous system. By postulating that a specific mechanism must exist to foster the induction of MTs I and II by numerous and diversified factors, we searched for and identified for the first time, MT receptors on U373MG cell membrane preparations, by using fluoresceinated MT I isoform probe; and by employing cysteine, glutathione, and four MT isoforms to determine high affinity and specific binding. MT receptors revealed a Kd value of 0.84 nM and a Bmax of 99.82 fmol/mg protein. Moreover, MT receptors were found in greater density on the surface of aggregated astrocytes. We postulate that conditions or agents generating reactive oxygen species may influence the expression of MT receptors.

Creating a new brand of mental health nurse

Mental health nurse training provision has been criticized for failing to develop practitioners with the appropriate skills to care for clients with severe mental illness (Owen and Sweeney, 1995), However, a tide of change is about to wash over the initial and ongoing education of mental health nurses.

Multielectrode nerve cuff stimulation of the median nerve produces selective movements in a raccoon animal model

In this study, an electrode system consisting of twelve small platinum dot electrodes imbedded in a spiral silicone rubber insulating cuff was used to investigate the feasibility of selective (regional) stimulation of the median nerves of the raccoon. Acute experiments in four raccoons consisted of functional responses observations, isometric force recordings from tendon attachments and postmortem fascicular mapping. Functional responses (elbow, wrist and/or digit flexion, pronation and/or thumb abduction) to selective stimulation were noted as dependent upon cuff electrode configuration (longitudinal tripole with and without field steering, as well as a transverse bipolar arrangement) and current level (threshold, 1/2 maximal, maximal). Muscle force recruitment curves (force as a function of stimulus amplitude) were plotted for flexor digitorum superficialis, flexor digitorum profundus, flexor carpi radialis, palmaris longus and pronator teres of three raccoons. Fascicular maps at the level of the nerve cuff were created indicating the approximate position of innervation to each of the aforementioned muscles, as well as other innervation such as paw fascicles, sensory fascicles, and elbow innervation (such as coracobrachialis). The greatest selectivity was observed at or near threshold current levels. In all four raccoons studied, a threshold electrode choice and stimulation strategy could be identified enabling selective production of either digit flexion, wrist flexion and/or digit and wrist flexion. It was possible to elicit a selective pronation response at threshold in three of the four animals. Selective elbow flexion at threshold could be produced in all four experiments. With stronger currents, additional movements were usually induced. The raccoon therefore appears to be a suitable, if challenging, animal model for further development of not only nerve cuff electrode approaches but perhaps other stimulation electrode technologies prior to human neuroprosthetic studies.

Uveitis associated with rifabutin and macrolide therapy for Mycobacterium avium intracellulare infection in AIDS patients

OBJECTIVE

Uveitis has been increasingly recognised as a side effect of rifabutin regimens in the prophylaxis and treatment of Mycobacterium avium intracellulare (MAI) infection. This study describes the clinical features and analyses the factors associated with rifabutin induced uveitis.

DESIGN

Retrospective observational study.

SETTING

Tertiary care institution, The Royal Hospitals NHS Trust, London.

PATIENTS

68 HIV seropositive individuals receiving rifabutin for prophylaxis or treatment of MAI infection.

RESULTS

11 episodes of uveitis occurred in 10 different individuals at a median of 62 days. The disease was bilateral in four and unilateral in the remainder. All subjects experienced ocular pain and photophobia and 9 individuals had a significant reduction in visual acuity. Uveitis was treated with mydriatics and topical steroids and resolved in all cases when rifabutin was stopped. The risk of uveitis was significantly increased with concurrent clarithromycin therapy, Odds Ratio 13.08, 95% Confidence Interval 1.98 to 83.12.

CONCLUSION

Rifabutin can cause a reversible uveitis. This risk is increased with concurrent clarithromycin therapy. Adverse drug interactions can be an important cause of morbidity in patients with advanced HIV disease.

Association between HIV distal symmetric polyneuropathy and Mycobacterium avium complex infection

OBJECTIVES

Pronounced infiltration of activated macrophages occurs in the peripheral nerves of patients with HIV distal symmetric polyneuropathy (DSPN). Mycobacterium avium complex (MAC) is a common facultative intracellular parasite of the macrophage in advanced HIV disease and may induce macrophage activation. Whether MAC disease is associated with DSPN was examined prospectively.

METHODS

One hundred and fifty consecutive patients with HIV infection were assessed for the probability of DSPN. Blood cultures for MAC were performed, independently of neurological assessment, as part of the investigation of unexplained fever, anaemia, weight loss, or, less commonly, diarrhoea.

RESULTS

There were 20 patients with possible, 14 with probable, and 22 with definite HIV DSPN. Blood cultures for MAC were performed on 80 patients, of whom 39 were positive and 41 negative. The test for trend, when corrected for CD4 count, disclosed a significant association (P = 0.01). There was no statistically significant association between DSPN and cytomegalovirus (CMV) disease.

CONCLUSION

Coinfection of the macrophage by MAC may further activate the HIV infected macrophage thereby accelerating the elaboration of neural toxins or MAC infection of the macrophage itself may lead to the production of neural toxins.

Laparoscopic versus open appendectomy: a prospective randomized trial of 81 patients

OBJECTIVE

To compare the efficacy of laparoscopic appendectomy (LA) and open appendectomy (OA) in the treatment of acute appendicitis.

DESIGN

A prospective randomized trial.

SETTING

A university teaching hospital.

PATIENTS

Eighty-one patients with a diagnosis of acute appendicitis were prospectively randomized to undergo either LA or OA. The two groups were matched for age and sex.

INTERVENTIONS

LA or OA.

MAIN OUTCOME MEASURES

Number of days in hospital and time to full recovery.

RESULTS

The mean hospital stay for LA was 3.23 days compared with 3.03 days for OA (p < 0.001). The mean number of narcotic injections required for patients in the LA group was 4.05 compared with 5.58 for patients in the OA group (p < 0.001). The mean time to complete recovery for patients in the LA group was 9.0 days compared with 16.2 days for patients in the OA group (p < 0.001). The mean operative time for LA was 73.8 minutes compared with 45.0 minutes for OA (p < 0.001). Three patients in the LA group had intra-abdominal abscesses (p > 0.25). No significant difference in wound infection rates was demonstrated (p > 0.05). Similarly, pain scores at 7 and 28 days showed no significant difference (p > 0.05).

CONCLUSIONS

With LA significantly fewer narcotic injections are required and there is a more rapid return to normal activities. LA takes longer to perform and was associated with three intra-abdominal abscesses. In cases of simple acute appendicitis the hospital stay for LA is significantly shorter.

Persistent mechanical allodynia following injury of the hand. Treatment through mobilization of the nervous system

Mechanical allodynia (MA) following hand injury is a well-documented clinical problem. The purpose of this pilot study was to examine the relationship between hand MA and the upper limb tension test (ULTT). The ULTT mechanically stresses the neural structures from the C5/6/7 neural foramina to the median nerve distally. This study examined 29 subjects with unilateral hand MA before and after a 2-week neural self-mobilization programme. There was a significant difference between the subjects' affected and unaffected sides when tested using the ULTT, both in reproduction of symptoms and in reduced range of motion of the ULTT. Following the self-mobilization program, there was an improvement in the range of the ULTT, and subjects reported a reduction in their symptoms. Complete recovery was not obtained in all cases. The results of this study suggest that the ULTT is a useful tool both in assessment and treatment of subjects with hand MA.

The raccoon as an animal model for upper limb neural prosthetics

The raccoon was evaluated as an animal model for upper limb neural prosthetics. This animal was selected primarily because the functional use of its forelimb mimics in many ways the usage in humans and because of its optimal size and commercial availability. Eight cadaver and fresh specimen forearms were dissected. Important characteristics of the raccoon forearm were: 1) large muscles in the volar forearm, 2) large digits in the paw that appear more similar to humans than to other species such as cat or dog, 3) persistence of two median nerve cords into the forearm, 4) no separation of individual tendons of flexor digitorum superficialis and flexor digitorum profundus in the carpal tunnel, 5) a small thumb digit with little function and 6) a primary origin of flexor policis longus on the proximal ulna with a secondary origin on the radius. Four animals were anesthetized and responses of the forearm and paw to stimulation of the volar forearm muscles with percutaneous electrodes were evaluated. A pair of stimulating electrodes was placed in each of four muscles or muscle groups. Recording electrodes were placed in two muscles which showed the greatest separation of muscle movements to stimulation. Stimulation currents just above threshold produced discrete motion as well as recordable EMG M-waves. Incremental increases in stimulation current produced an increase in M-wave amplitude up to a maximal stimulating current. Torque recordings for pronation, wrist flexion and finger flexion showed graded and selective responses. These results including anatomical descriptions indicate both the limitations of this animal model and its potential use in the development of upper limb neural prosthetics. We conclude that the raccoon model may be superior to other nonprimate animal models such as the cat because of its extensive forearm and paw movements.

Outreach, consolidation, and networking: Columbia's approach to successful integration of laboratory services in California

At the forefront of integrated laboratory services, Columbia Bay Area Healthcare Network's Lab Link provides a unique approach to operating hospital-based laboratories in today's heavily penetrated managed-care environment. Columbia recognizes that a combined strategy of laboratory consolidation, outreach, and networking is essential to compete successfully with commercial reference laboratories for local and statewide contracts. Implementing this model enables hospital laboratories to produce high quality, cost-effective test results while increasing volume and reducing duplication. When hospital laboratories consolidate and network with local and regional laboratories, inpatient and outpatients information is cross-fertilized through a web of information systems. Patients information can then be accessed easily and monitored throughout the continuum of care. The goal of this article is to provide hospital laboratories with a streamlined approach to structuring and delivering services while maintaining a competitive edge in the tumultuous healthcare market. The future of laboratory services within the hospital setting lies in the aggressive use of three elements--consolidation, outreach, and networking--to ensure quality service as well as economic viability.

Slow-wave sleep and symptomatology in schizophrenia and related psychotic disorders

Deficits in slow-wave sleep (SWS), or delta sleep, are frequently seen in schizophrenia, but their relationship with schizophrenic symptomatology remains unclear. We examined the association between visually scored and automated measures of SWS and positive and negative symptoms in a series of unmedicated patients with schizophrenia and related psychotic disorders. Total and average automated delta wave counts were significantly inversely associated with negative symptoms overall, and the psychomotor poverty syndrome in particular. Total delta counts were also inversely related to the disorganization syndrome. No relation was seen between reality distortion or the Brief Psychiatric Rating Scale (BPRS) positive symptoms and SWS. These findings support the view that SWS deficits may be related to negative symptoms of schizophrenia and may perhaps be mediated by impaired functioning of frontothalamic neural circuits.