Novel chyme reinfusion device for gastrointestinal fistulas and stomas: feasibility study

Background

High-output enterostomies and enteroatmospheric fistulas are common causes of intestinal failure, and may necessitate parenteral nutrition and prolonged hospital stay. Reinfusing lost chyme into the distal gut is known to be beneficial, but implementation has been limited because manual reinfusion is unpleasant and labour-intensive, and no devices are available. A new device is presented for reinfusing chyme easily and efficiently, with first-in-human data.

Methods

The device comprises a compact centrifugal pump that fits inside a standard stoma appliance. The pump is connected to an intestinal feeding tube inserted into the distal intestinal limb. The pump is activated across the appliance by magnetic coupling to a hand-held driver unit, effecting intermittent bolus reinfusion while avoiding effluent contact. Safety, technical and clinical factors were evaluated.

Results

Following microbiological safety testing, the device was evaluated in ten patients (median duration of installation 39·5 days; total 740 days). Indications included remediation of high-output losses (8 patients), dependency on parenteral nutrition (5), and gut rehabilitation before surgery (10). Reinfusion was well tolerated with use of regular boluses of approximately 200 ml, and no device-related serious adverse events occurred. Clinical benefits included resumption of oral diet, cessation of parenteral nutrition (4 of 5 patients), correction of electrolytes and liver enzymes, and hospital discharge (6 of 10). Of seven patients with intestinal continuity restored, one experienced postoperative ileus.

Conclusion

A novel chyme reinfusion device was developed and found to be safe, demonstrating potential benefits in remediating high-output losses, improving fluid and electrolyte balance, weaning off parenteral nutrition and improving surgical recovery. Pivotal trials and regulatory approvals are now in process.

Mid-gestational maternal cardiovascular profile in preterm and term pre-eclampsia: a prospective study

OBJECTIVE

Pre-eclampsia (PE) is associated with maternal cardiac remodelling and biventricular diastolic dysfunction. Preterm PE alone can also be associated with severe left ventricular hypertrophy and biventricular systolic dysfunction. The aim of this study was to assess whether the maternal cardiovascular profile at mid-gestation in nulliparous normotensive women differs in women destined to develop preterm PE versus those who will develop PE at term.

DESIGN

Prospective study.

SETTING

Tertiary referral university centre.

POPULATION

A total of 269 women, including 152 at increased risk of developing PE as determined by mid-gestational uterine artery Doppler assessment.

METHODS

Women underwent blood pressure profiling, echocardiography, cardiac tissue Doppler and strain rate analysis at 20-23 weeks of gestation.

MAIN OUTCOME MEASURES

Mid-gestational cardiovascular profile in women with normal pregnancy and those that subsequently developed preterm or term PE.

RESULTS

Pre-eclampsia subsequently developed in 46 women, including 18 with preterm PE. Women who subsequently developed PE, irrespective of gestation, had evidence of left ventricular concentric remodelling (33%) which was not found in the control women (P < 0.0001). Only women who developed preterm PE exhibited a high resistance-low volume haemodynamic state at mid-gestation. The latter group also had evidence of left ventricular diastolic or systolic dysfunction (33%) and segmental impaired myocardial relaxation (72%).

CONCLUSIONS

Asymptomatic cardiac diastolic dysfunction is evident at mid-gestation in women who subsequently develop preterm PE but not in those who develop term PE. These cardiac findings are useful in understanding the pathophysiology of PE and corroborate the concept that PE is not a single disorder, but a cluster of symptoms that have several different aetiologies.

Kinetic analysis of novel mono- and multivalent VHH-fragments and their application for molecular imaging of brain tumours

BACKGROUND AND PURPOSE

The overexpression of epidermal growth factor receptor (EGFR) and its mutated variant EGFRvIII occurs in 50% of glioblastoma multiforme. We developed antibody fragments against EGFR/EGFRvIII for molecular imaging and/or therapeutic targeting applications.

EXPERIMENTAL APPROACH

An anti-EGFR/EGFRvIII llama single-domain antibody (EG(2)) and two higher valency format constructs, bivalent EG(2)-hFc and pentavalent V2C-EG(2) sdAbs, were analysed in vitro for their binding affinities using surface plasmon resonance and cell binding studies, and in vivo using pharmacokinetic, biodistribution, optical imaging and fluorescent microscopy studies.

KEY RESULTS

Kinetic binding analyses by surface plasmon resonance revealed intrinsic affinities of 55 nM and 97 nM for the monovalent EG(2) to immobilized extracellular domains of EGFR and EGFRvIII, respectively, and a 10- to 600-fold increases in apparent affinities for the multivalent binders, V2C-EG(2) and EG(2)-hFc, respectively. In vivo pharmacokinetic and biodistribution studies in mice revealed plasma half-lives for EG(2), V2C-EG(2) and EG(2)-hFc of 41 min, 80 min and 12.5 h, respectively, as well as a significantly higher retention of EG(2)-hFc compared to the other two constructs in EGFR/EGFRvIII-expressing orthotopic brain tumours, resulting in the highest signal in the tumour region in optical imaging studies. Time domain volumetric optical imaging fusion with high-resolution micro-computed tomography of microvascular brain network confirmed EG(2)-hFc selective accumulation/retention in anatomically defined tumour regions.

CONCLUSIONS

Single domain antibodies can be optimized for molecular imaging applications by methods that improve their apparent affinity and prolong plasma half-life and, at the same time, preserve their ability to penetrate tumour parenchyma.

Mechatronic design of haptic forceps for robotic surgery

BACKGROUND

Haptic feedback increases operator performance and comfort during telerobotic manipulation. Feedback of grasping pressure is critical in many microsurgical tasks, yet no haptic interface for surgical tools is commercially available.

METHODS

Literature on the psychophysics of touch was reviewed to define the spectrum of human touch perception and the fidelity requirements of an ideal haptic interface. Mechanical design and control literature was reviewed to translate the psychophysical requirements to engineering specification. High-fidelity haptic forceps were then developed through an iterative process between engineering and surgery.

RESULTS

The forceps are a modular device that integrate with a haptic hand controller to add force feedback for tool actuation in telerobotic or virtual surgery. Their overall length is 153 mm and their mass is 125 g. A contact-free voice coil actuator generates force feedback at frequencies up to 800 Hz. Maximum force output is 6 N (2N continuous) and the force resolution is 4 mN. The forceps employ a contact-free magnetic position sensor as well as micro-machined accelerometers to measure opening/closing acceleration. Position resolution is 0.6 microm with 1.3 microm RMS noise. The forceps can simulate stiffness greater than 20N/mm or impedances smaller than 15 g with no noticeable haptic artifacts or friction.

CONCLUSION

As telerobotic surgery evolves, haptics will play an increasingly important role.

Further examination of relationships between life events and psychiatric symptoms in adults with intellectual disability

BACKGROUND

It has been proposed that people with intellectual disability (ID) might be similar to the general population in the way they respond to significant life events. Some preliminary findings have demonstrated that adults with ID who have experienced recent life events have an increased probability of having psychiatric problems. The aims of the present study were to determine whether previous findings can be replicated, and to examine the influence of additional diagnoses associated with ID on the strength of relationships between life event frequency and psychiatric problems.

METHODS

Adults with ID (n = 624), living either in staffed community accommodation or in family or foster homes, were assessed on the Developmental Behaviour Checklist for Adults (DBC-A) and a 37-item life events checklist. Carers who knew the person well acted as proxy informants.

RESULTS

People living in staffed accommodation experienced more life events than people living with natural or foster families. Life event frequency predicted DBC-A total score, five of six sub-scale scores, and caseness status, after significant demographic factors were taken into account. However, the strength of correlations between life event frequency and DBC-A total score varied among sub-groups identified by type of developmental disability and level of ID.

CONCLUSIONS

Weak but significant associations between emotional and behavioural problems and life events experienced by adults with ID were demonstrated, but it was also shown that the strength of such associations varies among sub-groups of this heterogeneous population. Future research needs to take account of the circumstances surrounding the life changes, the period of time over which changes might have taken place, and the meaning that the person might attach to the changes. Research into the causal relationship between exposure to life events and the onset of psychiatric problems is also warranted.

Who Calls QUIT®? The characteristics of smokers seeking advice via a telephone helpline compared with smokers attending a clinic and those in the general population

OBJECTIVE

To compare the characteristics of callers to a telephone helpline with those of smokers seeking assistance through a clinic and smokers in a general population sample.

STUDY DESIGN

Data were gathered from callers to the Quitline in May and June 2000. Screening data were used for smokers attending the South London & Maudsley NHS Smokers' Clinic from May 2000 to April 2001. The results of the 2000/2001 General Household Survey (GHS) were used to estimate the characteristics of smokers in the general population.

METHODS

Callers to the Quitline (n=1162) surveyed during the summer of 2000, smokers attending the Maudsley Hospital Smokers' Clinic between May 2000 and April 2001 (n=1127), and smokers surveyed in the GHS between April 2000 and March 2001 (n=14,089) were compared on demographic characteristics, tobacco dependence and readiness to quit.

RESULTS

Women and older smokers are more likely to seek help, but the Quitline attracts more calls from younger smokers. The age profile of helpline callers corresponds more closely to that of the general population of smokers than does the age profile of clinic attenders. Quitline callers are more dependent than the general population of smokers; clinic attenders are even more dependent. In comparison with the general population, the majority of Quitline callers have plans to quit smoking soon or have already stopped smoking.

CONCLUSIONS

Telephone helplines reach a more representative sample of smokers in various states of readiness to quit, and provide a service for a population not reached by clinics.

Detection of multiple enteric virus strains within a foodborne outbreak of gastroenteritis: an indication of the source of contamination

An outbreak of acute gastroenteritis of suspected viral aetiology occurred in April 2003 in the British Royal Fleet Auxiliary ship (RFA) Argus deployed in the Northern Arabian Gulf. There were 37 cases amongst a crew of 400 personnel. Of 13 samples examined from cases amongst the crew, six enteric viruses were detected by reverse transcriptase polymerase chain reaction (RT-PCR). Five different viruses were identified including, three norovirus genotypes, a sapovirus and a rotavirus. No multiple infections were detected. A common food source was implicated in the outbreak and epidemiological analysis showed a statistically significant association with salad as the source of the outbreak, with a relative risk of 3.41 (95% confidence interval of 1.7-6.81) of eating salad on a particular date prior to the onset of symptoms. Faecal contamination of the salad at source was the most probable explanation for the diversity of viruses detected and characterized.

Smoking: can we really make a difference?

The enormous health benefits of stopping smoking are now well established. Doctors have a vital role in motivating smokers and initiating quit attempts. The mainstay of National Health Service smoking cessation strategy should be the routine provision of brief opportunistic intervention in primary care, backed up by referral to a specialist smoking cessation service. There is an urgent need to increase substantially the numbers of smokers referred by general practitioners, other members of the primary care team, and those working in acute hospital trusts, to specialist smoking cessation services and for better channels of communication between the various agencies. Use of pharmacotherapy (nicotine replacement therapy or bupropion) in combination with behavioural support achieves higher cessation rates than either component alone and is the most effective way of helping smokers to stop. Smokers who quit often relapse and hence will need repeated help.

Gingival bleeding on probing increases after quitting smoking

BACKGROUND

Gingival inflammation associated with plaque accumulation is delayed or impaired in smokers. Anecdotal evidence suggests that smokers who quit experience an increase in gingival bleeding.

METHOD

A group of 27 subjects on a Quit-smoking programme were examined for changes in gingival health over a 4-6-week period.

RESULTS

The bleeding on probing with a constant force probe increased from 16% of sites to 32% of sites, despite improvements in the subjects oral hygiene.

CONCLUSION

This provides further evidence that tobacco smoking affects the inflammatory response and that these changes are reversible on quitting.

Effect of nicotine replacement and quitting smoking on circulating adhesion molecule profiles (sICAM-1, sCD44v5, sCD44v6)

BACKGROUND

Soluble ICAM-1 (sICAM-1; sCD54), sCD44v5 and sCD44v6 are circulating adhesion molecules, with immunomodulatory potential, that have been frequently attributed diagnostic, prognostic and aetiological significance in a number of inflammatory and malignant diseases. We have previously shown that systemic concentrations of these molecules are increased significantly in tobacco smokers, but reduce to within normal levels at 12 months following successful quitting.

MATERIALS AND METHODS

We have been able to extend these observations by measuring levels before and 4, 8, 22 and 52 weeks after smoking cessation in subjects receiving high-dose nicotine replacement therapy (25 mg of nicotine; n = 34) or placebo patches (n = 34) for 26 weeks. Smoking cessation was confirmed by regular measurement of expired-air CO levels and by plasma cotinine analysis.

RESULTS

Plasma sICAM-1, sCD44v5 and sCD44v6 concentrations all declined rapidly within 4 weeks of smoking cessation (P < 0.001 for all declines). Additionally, no differences were observed between those using nicotine replacement and those who were not for sICAM-1, sCD44v5, or sCD44v6.

CONCLUSIONS

The recovery in smoking-associated adhesion molecule profiles represents an almost immediate beneficial effect of smoking cessation. Nicotine replacement therapy is an effective aid to quitting and does not affect these recoveries. The elevated levels of these important risk factors in smokers (sICAM-1, sCD44v5 and sCD44v6) are linked to noxious element(s) in tobacco smoke other than nicotine or nicotine metabolites.

Exercise and multiple sclerosis: physiological, psychological, and quality of life issues

The case for the benefits of physical activity has been well documented in healthy individuals, and the potential for reducing the risk of mental and physical ill health is substantial. Yet, individuals with multiple sclerosis (MS) have long been advised to avoid participation in exercise in order to minimise the risk of exacerbations and symptoms of fatigue. There is, however, increasing interest in how acute and chronic exercise affect physiological and psychological functioning in MS. Much of the research has examined physiological tolerance to exercise and focused on responses in terms of heart rate, blood pressure, cardiorespiratory fitness, muscle function, and symptom stability. Little research has focused on understanding how exercise affects psychosocial functioning and brings about changes in depression, affect, mood, well-being, and quality of life. This paper provides a summary of the research exploring the efficacy of physical activity for people with MS. In addition, the key issues that face clinical practice are examined, and considerations for research are discussed.

Karyotypes found in the population declared at increased risk of Down syndrome following maternal serum screening

Of the 65 328 pregnancies of South Australian mothers screened by the South Australian Maternal Serum Antenatal Screening (SAMSAS) Programme between 1 January 1991 and 31 December 1997, 3431 (5.25%) were declared at increased risk of fetal Down syndrome. Fetal or neonatal karyotype was determined in 2737/3431 (79.8%) of these pregnancies, including 16 with early fetal loss. Interrogation of the database of the South Australian Neonatal Screening Service showed 643 live-born infants whose phenotype was not subsequently questioned among the 694 pregnancies whose karyotype was not determined. Of the remaining 51/3431 pregnancies, 19 ended in early fetal loss without karyotyping and no newborn screening or other records could be found for 32 cases. The 129 instances of abnormal karyotype found were Down syndrome (84), trisomy 18 (four), trisomy 13 (three), triploidy (two), female sex chromosome aneuploidy (six) and male sex chromosome aneuploidy (five), inherited balanced rearrangements (19), mosaic or de novo balanced abnormalities (four) and unbalanced karyotypes (two). In the pregnancies declared at increased risk of fetal Down syndrome, only the karyotype for Down syndrome occurred with a frequency greater than that expected for the general, pregnant population.

Smoking cessation: a consensus statement with special reference to primary care

Nicotine addiction is a serious medical condition that needs to be treated like any other chronic disease. Primary care must play a key role in smoking cessation and offering help should be a routine part of primary care practice. As the most frequent opportunity for intervention lies within primary care, GPs should ensure that they raise the issue of stopping smoking at least annually with their smoking patients. When the smoker is ready to stop, the initial personal involvement of the GP is likely to increase the chance of a successful quit attempt. Follow-up may be with another healthcare professional. The support of healthcare professionals for the smoker who is motivated to quit, combined with appropriate pharmacotherapy, can substantially increase the chances of a successful quit attempt. Secondary care staff should also make every effort to help people to stop smoking and should communicate effectively with primary care--opportunities during hospitalisation are frequently missed. Specialist smoking cessation clinics have an essential role in providing more intensive specialist treatment and the expertise to partner and support the primary care effort. Smoking cessation is one of the most cost-effective healthcare interventions that can be made.

Parametric study of the peak negative acoustic pressure distribution within the image plane of a phased array transducer

A study is presented in which the influence of pulse and transducer characteristics on the distribution of the peak negative acoustic pressure within the image plane of a phased array transducer is shown. First, the influence of the center frequency, the bandwidth of the transmitted pulse, the position of the focus point, and the properties of the phased array are investigated by computer simulation. These simulations show that both the maximal amplitude and the homogeneity of the distribution of the peak negative pressure within a sector image depend on these parameters. Most remarkably, they show that the maximal peak pressure does not necessarily occur on the geometrical symmetry axis of the array transducer but can occur at the outermost lateral lines of a sector image. Second, this effect is demonstrated experimentally by hydrophone measurements of the sound field produced by a standard, clinically used, 2.5-MHz phased array transducer. The experimental results agree well with the theoretical model. The relevance of this study for contrast echography and the safety measurements of ultrasound is discussed.

New insights into regional systolic and diastolic left ventricular function with tissue Doppler echocardiography: from qualitative analysis to a quantitative approach

Tissue Doppler echocardiography is a variation of conventional Doppler flow imaging. This modality allows quantification of the Doppler shift within the range of myocardial tissue motion. The velocity at a variety of myocardial sites can be determined and distinguished very rapidly by using Doppler techniques. The velocity of moving tissue can be studied with pulsed wave tissue Doppler sampling, which displays the velocity of a selected myocardial region against time, with high temporal resolution. In addition, the velocities can be calculated with time-velocity maps and displayed as color-encoded velocity maps in either an M-mode or 2-dimensional format. This review will focus on the technical aspects and the different methods of tissue Doppler echocardiography for the analysis of regional systolic and diastolic left ventricular function. Whereas pulsed wave tissue Doppler echocardiography allows measurements of velocities of a selected myocardial region, color tissue Doppler gives the best overview of cardiac dynamics because the entire scanned color data are displayed simultaneously. However, there is an increasing need for objective evaluation of tissue Doppler information. Digital images and postprocessing of the data allow for quantitative off-line analysis, and the different approaches and parameters proposed from different centers are discussed.

Plasma concentrations of reputed tumor-associated soluble CD44 isoforms (v5 and v6) in smokers are dose related and decline on smoking cessation

There is some evidence to suggest that smoking may affect circulating levels of CD44 (sCD44) molecules. Therefore, we investigated the effect of smoking on the circulating level of sCD44 by comparing the change in total sCD44, sCD44v5, and sCD44v6 concentrations over 1 year in a group of people who quit smoking (n = 30) and a control group of people who continued to smoke (n = 30). Smoking status and compliance were monitored by analysis of plasma cotinine and expired CO levels and also by self-reported tobacco use. We show a dose-dependent relationship between smoke intake and baseline plasma concentrations of reputed tumor-associated CD44 variant isoforms (sCD44v5 and sCD44v6) in smokers (n = 60). There was a significant decline in the level of both sCD44v5 and sCD44v6 in quitters as compared with continuing smokers [-13.2 (95% confidence interval, -7.6 to -18.8; P < 0.001) and -62.2 ng/ml (95% confidence interval, -33.9 to -90.6; P < 0.001), respectively], but not in the total sCD44 concentration. These results show that the increased concentrations of sCD44v5 and sCD44v6 in smokers are dose related and reversible and suggest that the attributed diagnostic specificity and prognostic value of sCD44 molecules in malignant and inflammatory disease may be affected by smoking status.

Circulating concentrations of C-reactive protein and total sialic acid in tobacco smokers remain unchanged following one year of validated smoking cessation

BACKGROUND

Elevated plasma concentrations of C-reactive protein (CRP) and total sialic acid (TSA) have been associated with increased cardiovascular risk. Additionally, levels of both CRP and TSA have been reported to be significantly elevated in smokers. However, it is not clear if the raised TSA and CRP levels noted in smokers are directly attributable to the smoking experience, or if they may be elevated due to a secondary mechanism(s), such as smoking-induced tissue inflammation.

SUBJECTS AND METHODS

We measured the plasma concentration of CRP and TSA in a group of smokers at baseline and following one year of validated smoking cessation (n = 30) and in a control group of tobacco users who continued to smoke over the year (n = 30).

RESULTS

The baseline concentration of TSA and CRP was 67.2 mg dL(-1) and 1.91 mg L(-1), respectively (n = 60). No significant dose-dependent relationship was noted between baseline CRP or TSA concentration and either plasma cotinine, expired-air CO or daily cigarette consumption. There was no difference in the mean change in CRP level in the quitters over one year (- 0.2 mg L(-1)) compared to the continuing smokers (+ 0.5 mg L(-1)), P = 0.80, or in the change in concentration of TSA in the quitters (- 2.7 mg dL(-1)) compared to the continuing smokers (+ 0.4 mg dL(-1)), P = 0.26.

CONCLUSIONS

As the circulating concentrations of both CRP and TSA remain unchanged following one year of smoking cessation, these results would suggest that the elevated levels noted in smokers are not directly attributable to tobacco use and are more likely to be elevated due to a secondary process that is yet to be established.

Gut gavage with antiendotoxin antibodies reduces the liberation of tumor necrosis factor-alpha after hemorrhage/resuscitation

OBJECTIVE

To evaluate the effect of gut gavage both alone and with enteral administration of monoclonal antibodies to endotoxin on the liberation of tumor necrosis factor (TNF)-alpha and subsequent hemodynamics after hemorrhage/resuscitation.

DESIGN

Dose response intervention, sham-controlled animal study.

SETTING

Research laboratory at a university medical center.

ANIMALS

Instrumented rats (250-325 g body weight) underwent standardized hemorrhage/resuscitation.

INTERVENTIONS

Animal groups received 4 hrs before hemorrhage/resuscitation: gastric gavage with Colyte alone (group 1), combined with E5 antiendotoxin at either 0.2 mg/100 g (group 2) or 2 mg/100 g body weight (group 3), or sham controls (group 4). There were six animals studied in each of the four groups.

MEASUREMENTS AND MAIN RESULTS

For animals receiving gut gavage and high-dose E5 antiendotoxin, plasma concentrations of TNF-alpha (pg/mL) at 120 mins after hemorrhage/resuscitation were significantly lower compared with sham controls (16+/-4 group 3; 65+/-36 group 4; mean +/- SD, p < .05). At 300 mins, this same treatment group had a significantly higher mean blood pressure (mm Hg) (110+/-6 group 3; 86+/-7 group 4: p < .05). Also at 300 mins after hemorrhage/resuscitation, plasma lactate concentrations (mmol/L) were significantly lower for all gut gavage treatment groups compared with sham control animals (1.9+/-0.2 group 1; 2.0+/-0.2 group 2; 1.8+/-0.2 group 3; 4.8+/-2.8 group 4, p < .05).

CONCLUSIONS

Prior treatment with gut gavage and enterally administered antiendotoxin antibodies reduces TNF-alpha liberation after hemorrhage/resuscitation and confers a subsequent improvement in hemodynamics and decreased plasma lactate concentrations. Such therapy may be efficacious in patients undergoing elective procedures where major hemorrhage is likely or in severely injured patients with continued or recurrent hemorrhage.

Dramatic decline in circulating intercellular adhesion molecule-1 concentration on quitting tobacco smoking

The concentration of soluble ICAM-1 (sICAM-1) is significantly elevated in smokers, but it is unclear if smoking is the direct cause of elevated sICAM-1 levels, if the relationship between smoking and sICAM-1 level is dose-dependent, and if smoking cessation may lead to a decline in sICAM-1. We sought to clarify the relationship between smoking and sICAM-1 in a group of smokers who quit smoking for 1 year (n = 30) and a control group who continued to smoke (n = 30). A dose-dependent relationship between plasma sICAM-1 concentration and daily cigarette consumption (P = 0.02), plasma cotinine level (P = 0.02), and expired CO level (P = 0.007) was observed at baseline (n = 60). The mean change in sICAM-1 concentration after 52 weeks was greater for quitters than for continuing smokers (mean difference = -71.1 ng/ml, P < 0.001). The influence of smoking on sICAM-1 needs to be carefully considered in clinical trials. Soluble ICAM-1 remains bioactive and may contribute to pathogenic processes; therefore, reduction in the concentration of circulating ICAM-1 molecules may directly contribute to the health benefits associated with smoking cessation.

Abnormal postsystolic thickening in acutely ischemic myocardium during coronary angioplasty: a velocity, strain, and strain rate doppler myocardial imaging study

We report a case in which the combination of gray scale imaging of wall thickness changes allied to color DMI regional velocity, strain, and strain rate data identified the development and regression of diastolic thickening in the acute ischemic segment during a right coronary artery percutaneous transluminal coronary angioplasty (PTCA). We also discuss the possible mechanisms and potential clinical implications of this finding.

Mechanisms of IL-10 production in human microglia-T cell interaction

IL-10, a cytokine with important anti-inflammatory properties, is generated within the CNS during neuroinflammation. The mechanism for its production is poorly understood. Since infiltrating lymphocytes come into close proximity with the macrophage-like cells of the CNS, the microglia, we have used an in vitro human microglia-T cell coculture system to address the mechanisms of IL-10 production. We demonstrate that microglia or activated T cells alone secrete negligible amounts of IL-10, but that their coculture results in significant IL-10 production, which was effected by both cell types. IL-10 generation was cell contact dependent, and treatment with anti-CD40, CTLA-4-Fc, or anti-CD23 decreased the IL-10 content in microglia-T cell cocultures. The combination of anti-CD40 and CTLA-4-Fc reduced IL-10 levels to the negligible amounts seen with T cells or microglia in isolation. By also measuring TNF-alpha levels, specificity of cytokine regulation was observed; while anti-CD40 and CTLA-4-Fc reduced IL-10 and TNF-alpha levels, anti-CD23 did not affect TNF-alpha while attenuating IL-10 generation. Anti-very late Ag-4, which decreased TNF-alpha levels, did not affect IL-10. These results implicate the CD40, B7, and CD23 pathways in IL-10 production following microglia-T cell encounter and have relevance to the regulation of an anti-inflammatory response within the CNS.

Gelatinase-A (MMP-2), gelatinase-B (MMP-9) and membrane type matrix metalloproteinase-1 (MT1-MMP) are involved in different aspects of the pathophysiology of malignant gliomas

Matrix metalloproteinases (MMPs) have been implicated as important factors in gliomas since they may both facilitate invasion into the surrounding brain and participate in neovascularization. We have tested the hypothesis that deregulated expression of gelatinase-A or B, or an activator of gelatinase-A, MT1-MMP, may contribute directly to human gliomas by quantifying the expression of these MMPs in 46 brain tumour specimens and seven control tissues. Quantitative RT-PCR and gelatin zymography showed that gelatinase-A in glioma specimens was higher than in normal tissue; these were significantly elevated in low grade gliomas and remained elevated in GBMs. Gelatinase-B transcript and activity levels were also higher than in normal brain and more strongly correlated with tumour grade. We did not see a close relationship between the levels of expression of MT1-MMP mRNA and amounts of activated gelatinase-A. In situ hybridization localized gelatinase-A and MT1-MMP transcripts to normal neuronal and glia, malignant glioma cells and blood vessels. In contrast, gelatinase-B showed a more restricted pattern of expression; it was strongly expressed in blood vessels at proliferating margins, as well as tumour cells in some cases. These data suggest that gelatinase-A, -B and MT1-MMP are important in the pathophysiology of human gliomas. The primary role of gelatinase-B may lie in remodelling associated with neovascularization, whereas gelatinase-A and MT1-MMP may be involved in both glial invasion and angiogenesis. © 1999 Cancer Research Campaign

Gelatinase-A (MMP-2), gelatinase-B (MMP-9) and membrane type matrix metalloproteinase-1 (MT1-MMP) are involved in different aspects of the pathophysiology of malignant gliomas

Matrix metalloproteinases (MMPs) have been implicated as important factors in gliomas since they may both facilitate invasion into the surrounding brain and participate in neovascularization. We have tested the hypothesis that deregulated expression of gelatinase-A or B, or an activator of gelatinase-A, MT1-MMP, may contribute directly to human gliomas by quantifying the expression of these MMPs in 46 brain tumour specimens and seven control tissues. Quantitative RT-PCR and gelatin zymography showed that gelatinase-A in glioma specimens was higher than in normal tissue; these were significantly elevated in low grade gliomas and remained elevated in GBMs. Gelatinase-B transcript and activity levels were also higher than in normal brain and more strongly correlated with tumour grade. We did not see a close relationship between the levels of expression of MT1-MMP mRNA and amounts of activated gelatinase-A. In situ hybridization localized gelatinase-A and MT1-MMP transcripts to normal neuronal and glia, malignant glioma cells and blood vessels. In contrast, gelatinase-B showed a more restricted pattern of expression; it was strongly expressed in blood vessels at proliferating margins, as well as tumour cells in some cases. These data suggest that gelatinase-A, -B and MT1-MMP are important in the pathophysiology of human gliomas. The primary role of gelatinase-B may lie in remodelling associated with neovascularization, whereas gelatinase-A and MT1-MMP may be involved in both glial invasion and angiogenesis.

Robustness of integrated backscatter for myocardial tissue characterization

Integrated backscatter (IB) has been used for ultrasonic tissue characterization. To assess the potential variables in IB measurements, we performed both theoretical simulations and in vitro phantom measurements. First, we simulated data in which the scatterer position randomly was varied. IB values for the resulting images were calculated. Second, RF data from a tissue-mimicking phantom were acquired. Third, an adapted imaging approach, based on phase insensitivity, was evaluated. For both the simulations and phantom measurements, IB showed a standard deviation of +/-20%. These large deviations can be explained by variations in interference of signals and are not related to the state of the tissue. Small deviations in position of the scatterers resulted in important variations in IB. They must be taken into account and may limit the use of IB in cardiological applications. An improvement potentially can be obtained using phase insensitivity in new ultrasound processing schemes.

Nicotine availability from Eclipse tobacco-heating cigarette

A cigarette which heats rather than burns tobacco (Premier) was introduced in 1988, but was unacceptable due to unpleasant taste and low nicotine intake. We examined availability of nicotine from a new version (Eclipse), in the same four subjects as our earlier Premier study. Average blood nicotine boosts of 23.7 and 17.8 ng/ml were obtained from smoking a first and second Eclipse. This substantially exceeds intake from Premier (boost 13 ng/ml) and that obtained by heavy smokers from conventional brands (boost 12-15 ng/ml). Eclipse (or similar product) may be the best option for averting Peto's dire warnings of rising millions of annual smoking deaths in the 2020s, and its potential for large-scale, long-term switching warrants further study.

Long-term glioblastoma multiforme survivors: a population-based study

BACKGROUND

Long-term glioblastoma multiforme survivors (LTGBMS) are uncommon. The frequency which these occur in an unselected population and factors which produce these unusually long survivors are unknown.

OBJECTIVES

To determine in a population-based study 1) the frequency of LTGBMS in a population and 2) identify which patient, treatment or tumor characteristics would predict which glioblastoma (GBM) patient would become a LTGBMS.

METHODS

The Alberta Cancer Registry was used to identify all patients diagnosed with GBM in southern Alberta between 1/1/75-12/31/91. Patient charts were reviewed and histology re-examined by a blinded neuropathologist. LTGBMS were defined as GBM patients surviving > or = 3 years after diagnosis. Each LTGBMS was compared to three age-, gender-, and year of diagnosis-matched controls to compare patient, treatment, and tumor factors to GBM patients without long-term survival.

RESULTS

There were 279 GBMs diagnosed in the study period. Five (1.8%) survived > or = three years (range, 3.2-15.8 years). Seven additional long-term survivors, who carried a diagnosis of GBM, were excluded after neuropathologic review; the most common revised diagnosis was malignant oligodendroglioma. LTGBMS (avg. age = 45 years) were significantly younger when compared to all GBM patients (avg. age = 59 years, p = 0.0001) diagnosed in the study period. LTGBMS had a higher KPS at diagnosis (p = 0.001) compared to controls. Tumors from LTGBMS tended to have fewer mitoses and a lower Ki-67 cellular proliferative index compared to controls. Radiation-induced dementia was common and disabling in LTGBMS.

CONCLUSIONS

These data highlight the dismal prognosis for GBM patients who have both a short median survival and very small chance (1.8%) of long-term survival. The LTGBMS were younger, had a higher performance status, and their tumors tended to proliferate less rapidly than control GBM patients. When long-term survival does occur it is often accompanied by severe treatment-induced dementia.

High levels of gelatinase-B and active gelatinase-A in metastatic glioblastoma

PURPOSE

Extra-neural metastases from glioblastoma multiforme (GBM) are rare. Because gelatinases-A and -B have been implicated in tumor invasion/metastasis in non-neural tumors, we compared the expression of gelatinase-A and -B in 2 patients (both had a prior craniotomy performed) with extraneural metastases from GBM to expression levels in 24 other gliomas; 15 non-metastatic GBMs, 9 other lower grade gliomas, and 7 normal brain tissues.

METHODS

The intracerebral tumor from both patients, patient # 1's extraneural metastases, 24 other gliomas, 1 sample of reactive astrocytes and 7 normal brain tissues were studied using gelatin zymography. The active form of gelatinases was confirmed by co-migration after activation with APMA.

RESULTS

Expression of the latent form of gelatinase-A correlated with glioma grade (r = 0.486; p = 0.0053). Active gelatinase-A was found only in the 2 GBMs with extraneural metastases and patient # 1's cervical metastases. In contrast, latent gelatinase-B levels correlated more strongly with histologic grade (r = 0.577; p = 0.0009) (higher levels with higher grades). Very high levels of gelatinase-B were seen in both GBMs with extraneural metastases, a cervical extraneural metastases, and 2 GBMs without metastases.

CONCLUSIONS

We observed that gelatinases-A and -B are present in most gliomas but we found active gelatinase-A only in the GBMs with extraneural metastases suggesting that the active form of this enzyme may determine the metastatic potential of GBMs. We propose that high levels of gelatinolytic activities are associated with intracerebral invasion and rarely, metastases of GBMs.

A prospective quantitative study of sensory deficits after whole sural nerve biopsies in diabetic and nondiabetic patients. Surgical approach and the role of collateral sprouting

BACKGROUND

Sural nerve biopsy (Sbx) has been employed for the diagnosis of peripheral neuropathies and for multicenter trials of therapy in diabetic neuropathy. There is only limited prospective information available about what factors influence the resolution of the sensory deficit (Sdef) after biopsy.

METHODS

We prospectively studied the surface area of skin Sdef after whole human Sbx in diabetic and nondiabetic patients for up to 18 months after the procedure. Sdef was determined by mapping, in two dimensions, the area of loss to pinprick and light touch in the sural distribution using a transparent boot-like device with 1-square-cm grid markings. At the same time, patients were interviewed about biopsy-related symptoms.

RESULTS

Overall, the Sdef in all patients declined by an average of 91 +/- 3% at 18 months. The pattern of Sdef decline indicated that collateral sprouting was the mechanism of sensory reinnervation. The extent of Sdef at 6, 12, or 18 months did not differ between diabetics and nondiabetics. In diabetics, there was a correlation between sensory reinnervation with pre-biopsy sural nerve potential amplitude and HbA1C level, but not with age or diabetes duration. Diabetic patients who had nerve resections starting at or below the center of a plane through the lateral malleolus and traveling proximally for 7 cm or less had a Sdef that was less than patients with longer and more proximal nerve resections. The majority of patients had unpleasant but mild mechanically elicited sensory symptoms at 1 year that had improved in most, but not all patients, by 18 months.

CONCLUSIONS

Sbx is associated with prolonged sensory symptoms and sensory loss. Recovery occurs by collateral reinnervation.

High levels of gelatinase-B and active gelatinase-A in metastatic glioblastoma

PURPOSE

Extra-neural metastases from glioblastoma multiforme (GBM) are rare. Because gelatinases-A and -B have been implicated in tumor invasion/metastasis in non-neural tumors, we compared the expression of gelatinase-A and -B in 2 patients (both had a prior craniotomy performed) with extraneural metastases from GBM to expression levels in 24 other gliomas; 15 non-metastatic GBMs, 9 other lower grade gliomas, and 7 normal brain tissues.

METHODS

The intracerebral tumor from both patients, patient # 1's extraneural metastases, 24 other gliomas, 1 sample of reactive astrocytes and 7 normal brain tissues were studied using gelatin zymography. The active form of gelatinases was confirmed by co-migration after activation with APMA.

RESULTS

Expression of the latent form of gelatinase-A correlated with glioma grade (r = 0.486; p = 0.0053). Active gelatinase-A was found only in the 2 GBMs with extraneural metastases and patient # 1's cervical metastases. In contrast, latent gelatinase-B levels correlated more strongly with histologic grade (r = 0.577; p = 0.0009) (higher levels with higher grades). Very high levels of gelatinase-B were seen in both GBMs with extraneural metastases, a cervical extraneural metastases, and 2 GBMs without metastases.

CONCLUSIONS

We observed that gelatinases-A and -B are present in most gliomas but we found active gelatinase-A only in the GBMs with extraneural metastases suggesting that the active form of this enzyme may determine the metastatic potential of GBMs. We propose that high levels of gelatinolytic activities are associated with intracerebral invasion and rarely, metastases of GBMs.

Metastases to meningioma

We describe a patient with metastatic disease to an intracranial meningioma in which MR images showed multiple foci of intense enhancement within a background of moderate enhancement. The discrete foci proved to be metastatic disease from the patient's known breast carcinoma.