Removal of inhibitory substances from human fecal specimens for detection of group A rotaviruses by reverse transcriptase and polymerase chain reactions

A method was developed for the purification of rotavirus RNA from fecal extracts in order to permit the sensitive identification of group A rotavirus in fecal specimens by the polymerase chain reaction. Sequential reactions with reverse transcriptase and Taq polymerase with directed primers from rotavirus gene 6 yielded characteristic 259-base-pair fragments that were then visualized by silver stain on a polyacrylamide gel. As few as 500 genomic copies of purified rotavirus RNA could be detected in this manner. However, when the method was applied to fecal samples with added rotavirus virions, inhibition was noted in many of the fecal extracts which were tested. The inhibition could be reversed by dilution of the fecal extract, but sensitivity was also reduced by a corresponding dilutional factor. The inhibition was quantitatively removed by an added step in the extraction process that utilized chromatographic cellulose fiber powder (CF11 powder) to purify the rotavirus RNA during a series of rapid washing and elution steps. After CF11 purification, rotavirus RNA could be detected in experimental fecal samples at dilutions 1,000- to 10,000-fold beyond the detection limits of standard techniques such as enzyme immunoassay and the direct visualization of RNA following polyacrylamide gel electrophoresis. Furthermore, following purification by CF11, rotavirus RNA could be detected in all of seven enzyme-linked immunosorbent assay-positive fecal samples obtained from a child with rotavirus gastroenteritis; when CF11 purification was not performed, rotavirus RNA could be detected in only four of these samples, even after the removal of inhibitors by dilution of the extracts. Large-scale identification of rotavirus in fecal specimens may be possible by use of CF11 purification of viral RNA prior to sequential reactions with reverse transcriptase and Taq polymerase in a modified polymerase chain reaction.

A review of the current use of magnetic resonance imaging in pregnancy and safety implications for the fetus

This paper presents an overview of the application of and risks of exposure to Magnetic Resonance Imaging (MRI) in pregnancy. It reviews the risks to the fetus by considering the hazards in terms of the three main components of an MRI system. These are the static magnetic field, the time-varying magnetic gradient fields and the pulsed radio frequency fields. The hazards discussed are biological effects, miscarriage, heating effects and acoustic noise exposure. This paper also presents a survey of MRI sites within the United Kingdom to ascertain the extent of MRI usage in pregnancy. To validate the situation of MRI in pregnancy a survey was sent to 352 MR units throughout the United Kingdom. The questions were grouped to assess (a) maternal MRI diagnosis (b) fetal MRI and (c) work practices for pregnant MRI staff. The results showed that 91% of sites were imaging pregnant women in need of diagnosis in the second and third trimester. This paper highlights that MRI can add information for fetal central nervous system abnormalities identified by ultrasound screening, however within the UK direct fetal imaging was only performed in 8% of sites. This paper indicates the need for research to be undertaken for specific MRI clinical conditions. It also advises that risk assessment for pregnant staff working in MRI is performed, and that there is a clear need for further research into the effects of MRI in pregnancy as there is a need for clear authoritive advice.

Investigation of acoustic noise on 15 MRI scanners from 0.2 T to 3 T

Acoustic noise levels for fast MRI pulse sequences were surveyed on 14 systems with field strengths ranging from 0.2 T to 3 T. A microphone insensitive to the magnetic environment was placed close to the magnet isocenter and connected via an extension cable to a sound level meter outside the scan room. Measured noise levels varied from 82.5 +/- 0.1 dB(A) for a 0.23 T system to 118.4 +/- 1.3 dB(A) for a 3 T system. Further measurements on four of the closed-bore systems surveyed showed that: 1) pulse sequence parameters (particularly FOV and TR) were more influential in determining noise level than field strength, 2) the noise level was found to vary along the z-direction with a maximum near the bore entrance, and 3) in one of two systems tested there was a significant increase in noise with a volunteer present instead of a test object. The results underline the importance of hearing protection for patients and for staff spending extended periods in the scan room.

Endoleakage after stent-graft treatment of abdominal aneurysm: implications on pressure and imaging--an in vitro study

BACKGROUND

Endoleakage is a fairly common problem after endovascular repair of abdominal aortic aneurysm and may prevent successful exclusion of the aneurysm. The consequences of endoleakage in terms of pressure in the aneurysmal sac are not exactly known. Moreover, the diagnosis of endoleakage is a problem because visualization of endoleaks can be difficult.

METHOD

With an ex vivo model of circulation with an artificial aneurysm managed by means of a tube graft, studies were performed to evaluate precisely known diameters of endoleaks with both imaging techniques (computed tomography and digital subtraction angiography) and pressure measurements of the aneurysmal sac. The experiments were performed without endoleak (controls) and with 1.231-French (0.410 mm), 3-French (1 mm), and 7-French (2.33 mm) endoleaks. Pressure and imaging were evaluated in the absence and presence of a simulated open lumbar artery. The pressure in the prosthesis and in the aneurysmal sac were recorded simultaneously. Digital subtraction angiography with and without a Lucite acrylic plate, computed tomographic angiography, and delayed computed tomographic angiography were performed. For the first experiments, the aneurysmal sac was filled with starch solution. All tests were repeated with fresh thrombus in the aneurysmal sac.

RESULTS

Each endoleak was associated with a diastolic pressure in the aneurysmal sac that was identical to diastolic systemic pressure, although the pressure curve was damped. At digital subtraction angiography without a Lucite acrylic plate, the 1.231-French (0.410 mm) endoleak was visualized without an open lumbar artery. When a Lucite acrylic plate was added, the endoleak was not visible until a lumbar artery was opened. In the presence of thrombus within the aneurysmal sac, all endoleaks were not visualized at digital subtraction angiography. At computed tomographic angiography, all endoleaks were not visualized in the absence of a thrombus mass in the aneurysmal sac. In the presence of thrombus within the aneurysmal sac, the 1.231-French (0.410 mm) endoleak became visible after opening of a simulated lumbar artery. At delayed computed tomographic angiography, all endoleaks were visualized without and with thrombus.

CONCLUSION

Every endoleak, even a very small one, caused pressure greater than systemic diastolic pressure within the aneurysmal sac. However, small endoleaks were not visualized with digital subtraction angiography and computed tomographic angiography, whereas all endoleaks were visualized with a delayed computed tomographic angiography protocol. We believe that follow-up examinations after stent graft placement for aortic aneurysms should focus on pressure measurements, but until this is clinically feasible, delayed computed tomographic angiography should be performed.

High prevalence of vitamin D deficiency, secondary hyperparathyroidism and generalized bone pain in Turkish immigrants in Germany: identification of risk factors

INTRODUCTION

The aim of the study was to determine the prevalence of vitamin D deficiency, secondary hyperparathyroidism (sHPT), generalized bone pain and predictors of vitamin D deficiency in a cohort of 994 healthy adult urban residents (589 males, 405 females; age range: 16-69 years) consisting of 101 Germans, 327 Turkish residents of Turkey and 566 Turkish immigrants living in Germany.

METHODS

The mean (+/- standard deviation) for 25-hydroxyvitamin D [25(OH)D] and biointact parathyroid hormone (BioPTH) for the German men and women was 68.4 nmol/l and 26.7 pg/ml, respectively. Turkish residents of Turkey had a mean 25(OH)D and BioPTH of 40.6 nmol/l and 27.5 pg/ml, respectively, whereas Turkish residents of Germany had a 25(OH)D of 38.1 nmol/l and a BioPTH of 35.6 pg/ml.

RESULTS

Vitamin D insufficiency was common among Turkish nationals independent of whether they lived in Turkey or Germany; 75% had 25(OH)D levels of <50 nmol/l. Turkish females had a higher prevalence of 25(OH)D deficiency (<25 nmol/l) than Turkish males: 30 and 19% of Turkish females living in Germany and Turkey were severely vitamin D deficient compared to 8% and 6% of Turkish males living in Germany and Turkey, respectively. With respect to BioPTH levels, 31% of Turkish females and 21% of Turkish males had elevated BioPTH levels in contrast to only 15% of females and 4% of males living in Turkey. Unconditional logistic regression analysis identified the most important predictors for low 25(OH)D levels as sex, body mass index, lack of sun exposure and living at a higher latitude. Additionally, wearing a scarf and number of children were found to be an independent risk factor for vitamin D deficiency in Turkish women living in Turkey and Germany. A strong correlation between low 25(OH)D levels and higher rates and longer duration of generalized bone and/or muscle aches and pains (often diagnosed as fibromyalgia) was observed.

CONCLUSION

Secondary hyperparathyroidism and vitamin D deficiency was found to be common among Turkish immigrants living in Germany, especially in veiled women. Therefore, the monitoring of vitamin D status--i.e. 25(OH)D and PTH--in Turkish immigrants is warranted and once a deficiency is identified, it should be appropriately treated.

Efficacy of a self-esteem module in the empowerment of individuals with schizophrenia

To enhance empowerment and improve self-esteem among individuals with severe and persistent mental illness, a 12-week "module" (a self-contained program of activities) was created and tested in a randomized clinical trial. Fifty-one individuals with schizophrenia were assigned to the experimental group in addition to regular treatment, and 44 individuals participated in a control group that continued with regular treatment only. Psychosocial, diagnostic, neurocognitive, and symptomatology measures were taken for all 95 subjects before treatment (T0), after treatment (T1), and at a 6-month follow-up (T2). Results indicated module effects on coping skills (active coping skills significantly increased) and psychotic symptoms (positive symptoms significantly decreased), demonstrating the efficacy of this particular type of intervention. Interpretation of the results highlighted the significance of the environment and the role it could potentially play in supporting the empowerment of severely mentally ill individuals.

Improved detection of rotavirus shedding by polymerase chain reaction

To improve identification of children excreting rotavirus a method for the amplification of rotavirus RNA by the polymerase chain reaction (PCR) was developed. The assay was compared with a solid-phase enzyme immunoassay in the detection of rotavirus shedding by infants in hospital during the winter peak of rotavirus infections. Forty children were studied in an intermediate care unit after transfer from intensive care units. Only two were admitted primarily because of diarrhoea; the other thirty-eight were admitted for management of various other disorders. Rotavirus shedding was detected by enzyme immunoassay in twenty of the infants, and nine of these (aged 1 week to 8 months) remained in hospital for more than 5 days after the initial detection of rotavirus and could be studied long term. Of 103 faecal samples from the nine infants, 60 (58%) contained rotavirus RNA detected by reverse-transcriptase (RT)/PCR, whereas only 37 (36%) were positive for rotavirus antigen by the immunoassay (chi 2 = 10.3, p less than 0.002). The geometric mean time of rotavirus shedding was 9.5 (range 1-19) days as detected by RT/PCR and 5.7 (range 1-17) days by the immunoassay (p less than 0.018). In five of the nine children, RT/PCR detected rotavirus shedding for 2-7 days longer than the immunoassay and in four children RT/PCR was positive 1 or more days before rotavirus antigen was detected. Further studies should attempt to find out whether infected infants are capable of spreading wild-type virus during periods when they are not shedding antigen as detectable by enzyme immunoassay.

Pharmacological thrombolysis in Budd Chiari syndrome: a single centre experience and review of the literature

BACKGROUND/AIMS

To review our experience of thrombolytic therapy in patients with acute Budd Chiari syndrome (BCS).

METHODS

Records of 10 patients with BCS, treated by thrombolysis over a 12-year period were retrospectively analysed for demographics, clinical presentation/duration, primary disease, thrombolytic regimen, and follow-up. The same characteristics were also studied in previously reported patients. The agent used was recombinant tissue plasminogen activator (tPA) in all patients.

RESULTS

Thrombolysis was used 12 times in 10 patients. Infusion was made systemically in three patients, into the hepatic artery in one patient, locally into a hepatic vein and/or IVC in four patients and locally within TIPS/portal vein in two patients. Only one infusion made systemically was partially successful. Adjunctive balloon angioplasty and/or stent insertion was undertaken for all eight procedures (in six patients) where local infusion was into the hepatic vein or TIPS. Six of these were ultimately successful (in five patients) and two were unsuccessful. Thrombolysis was more likely to be successful in the presence of a short history of thrombosis, when the thrombolytic agent was locally infused and when it was combined with a successful radiological procedure. Mean follow-up was 4.5 years (range 1-10 years). No serious bleeding complication occurred.

CONCLUSIONS

We observed no benefit from thrombolysis when delivered systemically or arterially except in one case. Thrombolysis was useful in adjunctive management of BCS when the drug was infused locally into recently thrombosed veins that had appreciable flow following partial recanalisation. Thrombolysis was clearly of benefit in the repermeation of occluded/partially occluded hepatic veins/TIPS when early detection of new thrombus followed interventional procedures such as balloon angioplasty or stenting of hepatic veins.

Clinical spectrum, investigations and treatment of Budd-Chiari syndrome

The clinical presentation, investigations, therapeutic modalities, prognosis and outcome of 44 patients with Budd-Chiari syndrome (BCS) were reviewed. There were 27 women and 17 men. Median age at presentation was 37 years (range 14-60). Possible aetiological factors were identified in 31 patients (70%). Myeloproliferative disorders were the commonest aetiology. Abdominal pain and swelling were the commonest presenting symptoms. Sixteen patients underwent a shunt operation (14 mesocaval, 2 mesoatrial). Ten patients had liver transplantation. Eleven patients had angioplasty/stent as their only treatment, and seven were treated medically or died before any treatment was instituted. Radiological intervention was comparable to mesocaval shunt in relieving patients' symptoms and in achieving good long-term results. Medical treatment and liver transplantation both yielded poor results. Radiological intervention in the form of balloon angioplasty or stent placement gives good results in a subgroup of BCS patients, and should be tried first to relieve the hepatic outflow obstruction. Mesocaval shunts provide good results in selected cases. Underlying haematological causes should be intensively investigated and promptly treated.

Detection of rotaviruses in the day care environment by reverse transcriptase polymerase chain reaction

Group A rotavirus is an important cause of morbidity among infants and toddlers in day care centers. Transmission by the fecal-oral route is well established, but fomites and environmental surfaces may also play an important role in transmission. A highly sensitive polymerase chain reaction (PCR) assay was used to detect rotavirus RNA in day care environments. Areas sampled included floors, diaper change areas, toy balls, and other surfaces. In two centers undergoing outbreaks of rotavirus, 7 (39%) of 18 toy balls had detectable rotavirus as did 8 (21%) of 39 swabs from environmental surfaces. By comparison, only 1 (5%) of 21 toy balls and 1 (2%) of 44 environmental surface swabs had detectable rotavirus in centers without rotavirus outbreaks (P = .0001). Thus, rotaviruses are highly prevalent in day care centers during outbreaks of diarrhea. The monitoring of environments by sensitive nucleic acid amplification techniques may lead to strategies for the diminution of disease transmission within the day care environment.

Randomized, prospective, observational simulation study comparing residents' needle-guided vs free-hand ultrasound techniques for central venous catheter access

BACKGROUND

Short-axis ultrasound-guided placement of central venous catheters (CVCs) is widely accepted as safe practice. However, utilizing the long-axis approach could further improve safety, as it allows for better visualization of the needle as it is advanced to the target vessel. However, the long-axis approach has not widely been used due to the technical difficulty. Recently, a new needle guidance device has become available to aid in the long-axis approach. We hypothesized that the use of a needle guide paired with the long-axis approach would facilitate puncture of the target vessel in a simulation model more effectively than similar free-hand techniques.

METHODS

A prospective observational study of anaesthesia residents using a CVC partial-task training device was conducted. Each resident performed needle puncture of the target vessel with three different techniques, assigned in random order: short-axis free hand (S-FH), long-axis free hand (L-FH), and long-axis needle guide (NG). To prove the effectiveness of the needle guide, the fraction of time the needle tip remained in view of the ultrasound was recorded and compared. Time required for completing the task and the number of needle sticks and needle re-directions were compared.

RESULTS

Thirty-three residents participated in the study. The fraction of time the needle tip remained in view of the ultrasound was significantly higher for the residents using NG [0.90 (0.10)] compared with residents using the other techniques [L-FH: 0.36 (0.20), S-FH: 0.18 (0.10)] (P<0.001). For each resident, the use of the needle guide in the long-axis approach increased visualization by 352 (276)% compared with that of L-FH and by 1028 (1804) % compared with that of S-FH. There was no significant difference in time required to puncture the target between NG [23.7 (14.6) s] and L-FH [30.3 (36.5) s] (P=0.21); however, both were significantly longer than S-FH [17.0 (13.3) s] (P=0.012). The numbers of needle sticks and of needle re-directions did not differ among the groups.

CONCLUSIONS

The needle guide device used in the long-axis approach improved the needle visualization compared with free-hand techniques. The needle guide used in the long-axis technique, however, did not facilitate puncture of the target vessel in this simulation model when compared with free-hand techniques.

Genetic fingerprinting of Theobroma clones using randomly amplified polymorphic DNA markers

Randomly amplified polymorphic DNA (RAPD) markers have been used to characterise cocoa clones representing the three main cultivated subpopulations: Criollo, Forastero and Trinitario. The use of single primers of arbitrary nucleotide sequence resulted in the selective amplification of DNA fragments which were unique to the individual cocoa clones studied. The use of a single primer allowed each of the clones evaluated to be unequivocally characterised. The application of RAPD markers for the evaluation of germplasm and cocoa improvement programmes are discussed.

CASIG: a consumer-centered assessment for planning individualized treatment and evaluating program outcomes

This paper reports the psychometric characteristics of a measure that assesses the treatment outcomes of individuals with serious and persistent mental illness. Unlike other outcome measures, this one is designed to be embedded in the clinical process of planning and evaluating treatment. It collects individualized data, structures how the data are used to plan and evaluate a client's treatment, and produces aggregate information relevant for research and program purposes. Two parallel versions were developed: one for the client's self-report, and one for an informant's report. The self-report measure was administered by peer-interviewers to 244 community interviewees, and by inpatient peer-interviewers to 93 inpatient interviewees. The community interviewees also completed the BASIS-32 and SF-36. Informants for 103 of the community interviewees completed the informant version of the measure, and the CCAR. Inpatient staff completed the informant version for 161 inpatient residents without regard for matching the 93 inpatient interviewees. The two versions had acceptable internal consistency, test--retest, and interrater reliabilities. Correlations of the community interviewees' and informants' results with the BASIS-32, SF-36, and CCAR provided evidence of convergent and discriminant validity, as did contrasts between community and inpatients interviewees. The usefulness of the instrument for clinical, program and research purposes is discussed, with emphasis on the characteristics that enhance its value in clinical practice --- assessment of meaningful outcomes, operationalization of client empowerment, comprehensiveness, easy administration, and continuity across time and provider. Also discussed is a computer-based program to summarize and present the results in a rapid, clinically meaningful manner.

Management of anticoagulation in patients with prosthetic heart valves undergoing oral and maxillofacial operations

There is wide variation in the management of patients with mechanical prosthetic valves who are taking anticoagulants and who require non-cardiac surgery. In this paper, we outline a pragmatic, practical approach to the adjustment of anticoagulation in relation to both the degrees of surgical trauma during oral and maxillofacial surgery and the risk of thromboembolism associated with the prosthetic valve. For minor surgery, no adjustment of anticoagulation is undertaken if the International Normalized Ratio is less than 4.0, if local haemostatic methods and tranexamic acid mouthwashes are used. For major surgery, warfarin is stopped preoperatively and low-molecular-weight heparin is used. For emergency surgery, partial reversal of anticoagulation with low-dose parenteral vitamin K is obtained.

Use of recombinant factor VIIa (NovoSeven) in patients with Glanzmann thrombasthenia

Recombinant factor VIIa (rFVIIa; NovoSeven, Novo Nordisk, Bagsvaerd, Denmark) appears effective and relatively safe for the treatment of bleeding and for surgical prophylaxis in patients with Glanzmann thrombasthenia as reported to the International Registry on rFVIIa and Congenital Platelet Disorders. One of the shortcomings of the Registry data is the heterogeneity of treatment protocol, including dosage, number of doses used, duration of treatment before declaration of failure, and mode of rFVIIa administration (bolus v continuous infusion). The data are not yet sufficient to define optimal regimens for various indications such as the type of bleeding or the type of procedures. The place of this drug compared to platelet transfusion in the overall management of patients with Glanzmann thrombasthenia will need to be determined in relationship to a number of challenges and unresolved issues in the clinical care of these patients. These issues include: how to improve local measures for patients with mucosal bleeds, optimal management of young women during menarche, optimal platelet transfusion regimens for various indications, the relationship between antiplatelet antibodies detected by monoclonal antibody-specific immobilization of platelet antigens (MAIPA) and effectiveness of platelet transfusion, whether there are other biological tests that may correlate with effectiveness of platelet transfusion, and management of pregnancy and delivery regarding antiplatelet immunization.

Detection of animal and human group B rotaviruses in fecal specimens by polymerase chain reaction

A combined reverse transcriptase reaction-polymerase chain reaction (RT-PCR) was developed to achieve the sensitive detection of group B rotaviruses (GBR). Sequences derived from genomic segment 3 of the IDIR (intestinal disease of infant rats) strain of GBR permitted the detection of greater than or equal to 0.08 pg of purified IDIR genomic RNA (4,000 genome copies). Primers complementary to the terminal sequences of gene 11 of GBR strain ADRV (adult diarrhea rotavirus) allowed for the detection of as little as 0.008 pg of purified ADRV genomic RNA. Detection of heterologous strains of GBR was also observed with these primer pairs. IDIR gene 3 primers recognized greater than or equal to 8 pg of RNA from bovine GBR obtained from a variety of geographic locations. RNA from IDIR, but not bovine GBR, strains was detected by means of RT-PCR with ADRV gene 11 primers. Neither set of GBR primers was reactive in RT-PCR with fecal specimens containing group A rotaviruses or fecal specimens from uninfected controls. This RT-PCR assay permits the sensitive and specific detection of a variety of GBR in fecal specimens.

Local vibrations and negative thermal expansion in ZrW2O8

We present an x-ray pair distribution function (XPDF) analysis and extended x-ray absorption fine structure (EXAFS) data for ZrW2O8 (10-500 K) with a focus on the stiffness of the Zr-O-W linkage. The XPDF is highly sensitive to W-Zr and W-W correlations, but much less so to O-O or W-O correlations. The Zr-W peak in the XPDF data has a weak temperature dependence and, hence, this linkage is relatively stiff and does not permit bending of the Zr-O-W link. We propose that the low energy vibrational modes that lead to negative thermal expansion involve correlated rotations of ZrO6 octahedra that produce large <111> translations of the WO4 tetrahedra, rather than a transverse motion of O atoms that imply a flexible Zr-O-W linkage.

X-linked bulbo-spinal neuronopathy: a family study of three patients

The clinical features of two brothers and one nephew with X-linked recessive bulbo-spinal neuronopathy are described. The neurophysiological investigations and sural nerve biopsy, previously unreported, confirmed that both motor and sensory nerves are affected. Because of the genetic implications, the importance is stressed of recognising this disorder as a separate entity which should not be classified with the spinal muscular atrophies.

Translating evidence into practice: a shared priority in public health?

Translational and transdisciplinary research is needed to tackle complex public health problems. This article has three aims. Firstly, to determine how academics and non-academics (practitioners, policy makers and community workers) identified with the goals of the UKCRC Centre of Excellence for Public Health in Northern Ireland and how their attitudes varied in terms of knowledge brokerage and translation. Secondly, to map and analyse the network structure of the public health sector and the placement of the Centre within this. Thirdly, to aggregate responses from members of the network by work setting to construct the trans-sectoral network and devise the Root Mean Sum of Squares to determine the quality and potential value of connections across this network. The analysis was based on data collected from 98 individuals who attended the launch of the Centre in June 2008. Analysis of participant expectations and personal goals suggests that the academic members of the network were more likely to expect the work of the Centre to produce new knowledge than non-academics, but less likely to expect the Centre to generate health interventions and influence health policy. Academics were also less strongly oriented than non-academics to knowledge transfer as a personal goal, though more confident that research findings would be diffused beyond the immediate network. A central core of five nodes is crucial to the overall configuration of the regional public health network in Northern Ireland, with the Centre being well placed to exert influence within this. Though the overall network structure is fairly robust, the connections between some component parts of the network--such as academics and the third sector--are unidirectional. Identifying these differences and core network structure is key to translational and transdisciplinary research. Though exemplified in a regional study, these techniques are generalisable and applicable to many networks of interest: public health, interdisciplinary research or organisational involvement and stakeholder linkage.

Atomic force microscopy imaging of the human trigeminal ganglion

This paper describes an investigation of gangliocytes via imaging semithin sections of two human trigeminal ganglia with an atomic force microscope (AFM). Whereas semithin sections are usually employed for transmission electron microscopy, we adopted this special type of sample preparation for our AFM studies to extract topographical data from the gangliocyte itself and from the nucleus, the nucleolus, the crystal-arranged lipofuscin granules, and the cell-surrounding mantle cells; simultaneously we characterized the samples with error signal mode. This AFM-related technique revealed no information concerning friction force and elasticity due to the presence of the embedding material (epoxy), but it gave additional topographical contrast. These are the first images of the human trigeminal ganglion by AFM.

Information in magnetic resonance images: evaluation of signal, noise and contrast

The assessment of diagnostic image quality for MRI is considered. The assessment of three key image quality determinants is addressed: signal, noise and contrast. There is a distinction between random noise evaluation, for the calculation of the SNR, and structured noise evaluation for the assessment of image artefacts. Specific methods used are correlation techniques and the Wiener spectrum. Contrast is assessed by comparison of experimental data and theoretical predictions. For each assessment, the theory and method of the evaluation strategy are discussed. The discussion is illustrated with analysis results from commercial MR systems. The choice of analysis method and the subsequent derivation of quality indices are shown to be critical in respect of robustness and accuracy.

Molecular confirmation of germ line mosaicism for a submicroscopic deletion of chromosome 22q11

Submicroscopic deletions of chromosome 22q11 have been reported in a multiple anomaly syndrome variously labelled as velocardiofacial syndrome, conotruncal anomaly face syndrome, and Di George syndrome. Most 22q11 microdeletions occur sporadically, although in some cases the deletion may be transmitted. We describe two affected sibs with confirmed 22q11 deletions from unaffected parents who are not deleted. Haplotype analysis demonstrates that the deletion in the affected sibs has occurred on the same maternal chromosome 22. Furthermore, an unaffected sib was found to have inherited the same maternal haplotype at 22q11 in an undeleted form. This is the first molecular demonstration of germ line mosaicism for a microdeletion at chromosome 22q11 and highlights the need for caution in estimation of recurrence risks, even when constitutional deletions have been excluded on parental analysis.

Src family kinases are essential for primary aggregation by G(i) -coupled receptors

INTRODUCTION AND BACKGROUND

Adrenaline stimulates biphasic aggregation in plasma through the G(i) -coupled α(2A) -adrenoreceptor. In the present study, we demonstrate that both primary and secondary wave aggregation induced by adrenaline in plasma is blocked by two structurally distinct inhibitors of Src family kinases, dasatinib and PD0173952.

METHODS AND RESULTS

In contrast, primary aggregation is partially inhibited or unaffected in the presence of inhibitors of cyclo-oxygenase, phosphoinositide (PI) 3-kinases, and P2Y(1) and P2Y(12) ADP receptors, although secondary aggregation is abolished. The ability of adrenaline to inhibit adenylyl cyclase and to synergize with platelet agonists in mediating platelet activation in plasma is retained in the presence of Src family kinase inhibition. Moreover, adrenaline does not activate Src family kinases, as determined by western blotting of their regulatory tyrosines, suggesting that constitutive signaling from Src family kinases may underlie their role in activation. Adrenaline is widely used in clinical laboratories for investigation of patients with suspected bleeding disorders. In a group of 90 unrelated patients with a clinically diagnosed platelet bleeding disorder, we identified four who did not exhibit primary wave aggregation in response to adrenaline, although the catecholamine potentiated the response to other agonists, and five who failed to undergo secondary wave aggregation. In contrast, adrenaline stimulated biphasic aggregation in 60 controls. All of the patients with a defective response to adrenaline had impaired ADP-induced platelet activation.

CONCLUSIONS

The present results indicate a previously unappreciated role for Src family kinases in mediating G(i) signaling in plasma, and demonstrate heterogeneity in response to adrenaline in patients with a clinically diagnosed platelet disorder.

Direct activation of human peritoneal mesothelial cells by heat-killed microorganisms

OBJECTIVE

The aim of the study was to determine if human peritoneal mesothelial cells (HPMCs) can be activated directly by bacterial products contained in preparations of heat-killed Escherichia coli and staphylococci.

SUMMARY BACKGROUND DATA

It has been shown recently that cytokine-activated HPMCs produce the inflammatory mediators, interleukin-1, interleukin-6, interleukin-8, and macrophage chemotactic protein-1. Studies concerning the effects of bacterial products on HPMCs are scarce and have not yielded conclusive results.

METHODS

Growth-arrested HPMC monolayers were prepared from cell suspensions obtained by enzymatic disaggregation of small pieces of omentum. They were incubated for 24 hours with heat-killed E. coli (ATCC 25922), heat-killed staphylococci (ATCC 25933), or E. coli lipopolysaccharide, and the release of various cytokines in the culture media was measured by radioimmunoassays or enzyme-linked immunosorbent assays. Results were expressed as mean +/- standard error of the mean in picograms per milliliter of supernatant and analyzed with the Wilcoxon test; p values of less than 0.05 were considered significant.

RESULTS

Baseline production of interleukin-6, interleukin-8, the chemokine "regulated upon activation, normal T cell expressed and secreted" (RANTES), and macrophage chemotactic protein-1 varied widely from one omental preparation to the other. E. coli increased the release of these mediators: from 1206 +/- 316 pg/mL to 8480 +/- 2189 pg/mL for interleukin-6, from 285 +/- 58 pg/mL to 3164 +/- 1053 pg/mL for interleukin-8, from 7 +/- 5 pg/mL to 684 +/- 264 pg/mL for RANTES, and from 2212 +/- 346 pg/mL to 7726 +/- 1473 pg/mL for macrophage chemotactic protein-1. Heat-killed staphylococci did not alter significantly the production of RANTES or macrophage chemotactic protein-1 but increased the production of the two other cytokines from 1325 +/- 389 pg/mL to 2206 +/- 523 pg/mL for interleukin-6 and from 318 +/- 70 pg/mL to 819 +/- 265 pg/mL for interleukin-8.

CONCLUSIONS

The authors' results show that HPMCs are able to react to a direct stimulation with heat-killed microbes. They suggest that HPMCs, as well as resident macrophages, participate actively in the initiation and possibly in the modulation of intraperitonen inflammatory reactions.