Role of A Novel Angiogenesis FKBPL-CD44 Pathway in Preeclampsia Risk Stratification and Mesenchymal Stem Cell Treatment

CONTEXT

Preeclampsia is a leading cardiovascular complication in pregnancy lacking effective diagnostic and treatment strategies.

OBJECTIVE

To investigate the diagnostic and therapeutic target potential of the angiogenesis proteins, FK506-binding protein like (FKBPL) and CD44.

DESIGN AND INTERVENTION

FKBPL and CD44 plasma concentration or placental expression were determined in women pre- or postdiagnosis of preeclampsia. Trophoblast and endothelial cell function was assessed following mesenchymal stem cell (MSC) treatment and in the context of FKBPL signaling.

SETTINGS AND PARTICIPANTS

Human samples prediagnosis (15 and 20 weeks of gestation; n ≥ 57), or postdiagnosis (n = 18 for plasma; n = 4 for placenta) of preeclampsia were used to determine FKBPL and CD44 levels, compared to healthy controls. Trophoblast or endothelial cells were exposed to low/high oxygen, and treated with MSC-conditioned media (MSC-CM) or a FKBPL overexpression plasmid.

MAIN OUTCOME MEASURES

Preeclampsia risk stratification and diagnostic potential of FKBPL and CD44 were investigated. MSC treatment effects and FKBPL-CD44 signaling in trophoblast and endothelial cells were assessed.

RESULTS

The CD44/FKBPL ratio was reduced in placenta and plasma following clinical diagnosis of preeclampsia. At 20 weeks of gestation, a high plasma CD44/FKBPL ratio was independently associated with the 2.3-fold increased risk of preeclampsia (odds ratio = 2.3, 95% confidence interval [CI] 1.03-5.23, P = 0.04). In combination with high mean arterial blood pressure (>82.5 mmHg), the risk further increased to 3.9-fold (95% CI 1.30-11.84, P = 0.016). Both hypoxia and MSC-based therapy inhibited FKBPL-CD44 signaling, enhancing cell angiogenesis.

CONCLUSIONS

The FKBPL-CD44 pathway appears to have a central role in the pathogenesis of preeclampsia, showing promising utilities for early diagnostic and therapeutic purposes.

FKBPL and SIRT-1 Are Downregulated by Diabetes in Pregnancy Impacting on Angiogenesis and Endothelial Function

Diabetes in pregnancy is associated with adverse pregnancy outcomes including preterm birth. Although the mechanisms leading to these pregnancy complications are still poorly understood, aberrant angiogenesis and endothelial dysfunction play a key role. FKBPL and SIRT-1 are critical regulators of angiogenesis, however, their roles in pregnancies affected by diabetes have not been examined before in detail. Hence, this study aimed to investigate the role of FKBPL and SIRT-1 in pre-gestational (type 1 diabetes mellitus, T1D) and gestational diabetes mellitus (GDM). Placental protein expression of important angiogenesis proteins, FKBPL, SIRT-1, PlGF and VEGF-R1, was determined from pregnant women with GDM or T1D, and in the first trimester trophoblast cells exposed to high glucose (25 mM) and varying oxygen concentrations [21%, 6.5%, 2.5% (ACH-3Ps)]. Endothelial cell function was assessed in high glucose conditions (30 mM) and following FKBPL overexpression. Placental FKBPL protein expression was downregulated in T1D (FKBPL; p<0.05) whereas PlGF/VEGF-R1 were upregulated (p<0.05); correlations adjusted for gestational age were also significant. In the presence of GDM, only SIRT-1 was significantly downregulated (p<0.05) even when adjusted for gestational age (r=-0.92, p=0.001). Both FKBPL and SIRT-1 protein expression was reduced in ACH-3P cells in high glucose conditions associated with 6.5%/2.5% oxygen concentrations compared to experimental normoxia (21%; p<0.05). FKBPL overexpression in endothelial cells (HUVECs) exacerbated reduction in tubule formation compared to empty vector control, in high glucose conditions (junctions; p<0.01, branches; p<0.05). In conclusion, FKBPL and/or SIRT-1 downregulation in response to diabetic pregnancies may have a key role in the development of vascular dysfunction and associated complications affected by impaired placental angiogenesis.

The Use of Portable Computers: A Survey of Visually Impaired College Students

This survey of 10 visually impaired college students found that the students used portable (laptop) computers to produce assignments and to perform other tasks, as well as to take notes in class. The use of laptops seemed to foster the students’ independence and gave them sufficient time to complete their work.

Hypercapnic acidosis induces mitochondrial dysfunction and impairs the ability of mesenchymal stem cells to promote distal lung epithelial repair

Acute respiratory distress syndrome (ARDS) is a devastating disorder characterized by diffuse inflammation and edema formation. The main management strategy, low tidal volume ventilation, can be associated with the development of hypercapnic acidosis (HCA). Mesenchymal stem cells (MSCs) are a promising therapeutic candidate currently in early-phase clinical trials. The effects of HCA on the alveolar epithelium and capillary endothelium are not well established. The therapeutic efficacy of MSCs has never been reported in HCA. In the present study, we evaluated the effects of HCA on inflammatory response and reparative potential of the primary human small airway epithelial and lung microvasculature endothelial cells as well as on the capacity of bone marrow-derived MSCs to promote wound healing in vitro. We demonstrate that HCA attenuates the inflammatory response and reparative potential of primary human small airway epithelium and capillary endothelium and induces mitochondrial dysfunction. It was found that MSCs promote lung epithelial wound repair via the transfer of functional mitochondria; however, this proreparative effect of MSCs was lost in the setting of HCA. Therefore, HCA may adversely impact recovery from ARDS at the cellular level, whereas MSCs may not be therapeutically beneficial in patients with ARDS who develop HCA.-Fergie, N., Todd, N., McClements, L., McAuley, D., O'Kane, C., Krasnodembskaya, A. Hypercapnic acidosis induces mitochondrial dysfunction and impairs the ability of mesenchymal stem cells to promote distal lung epithelial repair.

Highly degradable porous melt-derived bioactive glass foam scaffolds for bone regeneration

A challenge in using bioactive melt-derived glass in bone regeneration is to produce scaffolds with interconnected pores while maintaining the amorphous nature of the glass and its associated bioactivity. Here we introduce a method for creating porous melt-derived bioactive glass foam scaffolds with low silica content and report in vitro and preliminary in vivo data. The gel-cast foaming process was adapted, employing temperature controlled gelation of gelatin, rather than the in situ acrylic polymerisation used previously. To form a 3D construct from melt derived glasses, particles must be fused via thermal processing, termed sintering. The original Bioglass® 45S5 composition crystallises upon sintering, altering its bioactivity, due to the temperature difference between the glass transition temperature and the crystallisation onset being small. Here, we optimised and compared scaffolds from three glass compositions, ICIE16, PSrBG and 13-93, which were selected due to their widened sintering windows. Amorphous scaffolds with modal pore interconnect diameters between 100-150µm and porosities of 75% had compressive strengths of 3.4±0.3MPa, 8.4±0.8MPa and 15.3±1.8MPa, for ICIE16, PSrBG and 13-93 respectively. These porosities and compressive strength values are within the range of cancellous bone, and greater than previously reported foamed scaffolds. Dental pulp stem cells attached to the scaffold surfaces during in vitro culture and were viable. In vivo, the scaffolds were found to regenerate bone in a rabbit model according to X-ray micro tomography imaging.

STATEMENT OF SIGNIFICANCE

This manuscript describes a new method for making scaffolds from bioactive glasses using highly bioactive glass compositions. The glass compositions have lower silica content that those that have been previously made into amorphous scaffolds and they have been designed to have similar network connectivity to that of the original (and commercially used) 45S5 Bioglass. The aim was to match Bioglass' bioactivity. The scaffolds retain the amorphous nature of bioactive glass while having an open pore structure and compressive strength similar to porous bone (the original 45S5 Bioglass crystallises during sintering, which can cause reduced bioactivity or instability). The new scaffolds showed unexpectedly rapid bone regeneration in a rabbit model.

Biotransformation of Silver Released from Nanoparticle Coated Titanium Implants Revealed in Regenerating Bone

Antimicrobial silver nanoparticle coatings have attracted interest for reducing prosthetic joint infection. However, few studies report in vivo investigations of the biotransformation of silver nanoparticles within the regenerating tissue and its impact on bone formation. We present a longitudinal investigation of the osseointegration of silver nanoparticle-coated additive manufactured titanium implants in rat tibial defects. Correlative imaging at different time points using nanoscale secondary ion mass spectrometry, transmission electron microscopy (TEM), histomorphometry, and 3D X-ray microcomputed tomography provided quantitative insight from the nano- to macroscales. The quality and quantity of newly formed bone is comparable between the uncoated and silver coated implants. The newly formed bone demonstrates a trabecular morphology with bone being located at the implant surface, and at a distance, at two weeks. Nanoscale elemental mapping of the bone-implant interface showed that silver was present primarily in the osseous tissue and colocalized with sulfur. TEM revealed silver sulfide nanoparticles in the newly regenerated bone, presenting strong evidence that the previously in vitro observed biotransformation of silver to silver sulfide occurs in vivo.

In vivo evaluation of a breast-specific magnetic resonance guided focused ultrasound system in a goat udder model

PURPOSE

This work further evaluates the functionality, efficacy, and safety of a new breast-specific magnetic resonance guided high intensity focused ultrasound (MRgFUS) system in an in vivo goat udder model.

METHODS

Eight female goats underwent an MRgFUS ablation procedure using the breast-specific MRgFUS system. Tissue classification was achieved through the 3D magnetic resonance imaging (MRI) acquisition of several contrasts (T1w, T2w, PDw, 3-point Dixon). The MRgFUS treatment was performed with a grid trajectory executed in one or two planes within the glandular tissue of the goat udder. Temperature was monitored using a 3D proton resonance frequency (PRF) MRI technique. Delayed contrast enhanced-MR images were acquired immediately and 14 days post MRgFUS treatment. A localized tissue excision was performed in one animal and histological analysis was performed. Animals were available for adoption at the conclusion of the study.

RESULTS

The breast-specific MRgFUS system was able to ablate regions ranging in size from 0.4 to 3.6 cm(3) in the goat udder model. Tissue damage was confirmed through the correlation of thermal dose measurements obtained with realtime 3D MR thermometry to delayed contrast enhanced-MR images immediately after the treatment and 14 days postablation. In general, lesions were longer in the ultrasound propagation direction, which is consistent with the dimensions of the ultrasound focal spot. Thermal dose volumes had better agreement with nonenhancing areas of the DCE-MRI images obtained 14 days after the MRgFUS treatment.

CONCLUSIONS

The system was able to successfully ablate lesions up to 3.6 cm(3). The thermal dose volume was found to correlate better with the 14-day postablation nonenhancing delayed contrast enhanced-MR image volumes. While the goat udder is not an ideal model for the human breast, this study has proven the feasibility of using this system on a wide variety of udder shapes and sizes, demonstrating the flexibility that would be required in order to treat human subjects.

Effects of MRTI sampling characteristics on estimation of HIFU SAR and tissue thermal diffusivity

While the non-invasive and three-dimensional nature of magnetic-resonance temperature imaging (MRTI) makes it a valuable tool for high-intensity focused ultrasound (HIFU) treatments, random and systematic errors in MRTI measurements may propagate into temperature-based parameter estimates used for pretreatment planning. This study assesses the MRTI effects of zero-mean Gaussian noise (SD = 0.0-2.0 °C), temporal sampling (tacq = 1.0-8.0 s), and spatial averaging (Res = 0.5-2.0 mm isotropic) on HIFU temperature measurements and temperature-based estimates of the amplitude and full width half maximum (FWHM) of the HIFU specific absorption rate and of tissue thermal diffusivity. The ultrasound beam used in simulations and ex vivo pork loin experiments has lateral and axial FWHM dimensions of 1.4 mm and 7.9 mm respectively. For spatial averaging simulations, beams with lateral FWHM varying from 1.2-2.2 mm are also assessed. Under noisy conditions, parameter estimates are improved by fitting to data from larger voxel regions. Varying the temporal sampling results in minimal changes in measured temperatures (<2% change) and parameter estimates (<5% change). For the HIFU beams studied, a spatial resolution of 1 × 1 × 3 mm(3) or smaller is required to keep errors in temperature and all estimated parameters less than 10%. By quantifying the errors associated with these sampling characteristics, this work provides researchers with appropriate MRTI conditions for obtaining estimates of parameters essential to pretreatment modeling of HIFU thermal therapies.

Design and characterization of a laterally mounted phased-array transducer breast-specific MRgHIFU device with integrated 11-channel receiver array

PURPOSE

This work presents the design and preliminary evaluation of a new laterally mounted phased-array MRI-guided high-intensity focused ultrasound (MRgHIFU) system with an integrated 11-channel phased-array radio frequency (RF) coil intended for breast cancer treatment. The design goals for the system included the ability to treat the majority of tumor locations, to increase the MR image's signal-to-noise ratio (SNR) throughout the treatment volume and to provide adequate comfort for the patient.

METHODS

In order to treat the majority of the breast volume, the device was designed such that the treated breast is suspended in a 17-cm diameter treatment cylinder. A laterally shooting 1-MHz, 256-element phased-array ultrasound transducer with flexible positioning is mounted outside the treatment cylinder. This configuration achieves a reduced water volume to minimize RF coil loading effects, to position the coils closer to the breast for increased signal sensitivity, and to reduce the MR image noise associated with using water as the coupling fluid. This design uses an 11-channel phased-array RF coil that is placed on the outer surface of the cylinder surrounding the breast. Mechanical positioning of the transducer and electronic steering of the focal spot enable placement of the ultrasound focus at arbitrary locations throughout the suspended breast. The treatment platform allows the patient to lie prone in a face-down position. The system was tested for comfort with 18 normal volunteers and SNR capabilities in one normal volunteer and for heating accuracy and stability in homogeneous phantom and inhomogeneous ex vivo porcine tissue.

RESULTS

There was a 61% increase in mean relative SNR achieved in a homogeneous phantom using the 11-channel RF coil when compared to using only a single-loop coil around the chest wall. The repeatability of the system's energy delivery in a single location was excellent, with less than 3% variability between repeated temperature measurements at the same location. The execution of a continuously sonicated, predefined 48-point, 8-min trajectory path resulted in an ablation volume of 8.17 cm(3), with one standard deviation of 0.35 cm(3) between inhomogeneous ex vivo tissue samples. Comfort testing resulted in negligible side effects for all volunteers.

CONCLUSIONS

The initial results suggest that this new device will potentially be suitable for MRgHIFU treatment in a wide range of breast sizes and tumor locations.

An 11-channel radio frequency phased array coil for magnetic resonance guided high-intensity focused ultrasound of the breast

In this study, a radio frequency phased array coil was built to image the breast in conjunction with a magnetic resonance guided high-intensity focused ultrasound (MRgHIFU) device designed specifically to treat the breast in a treatment cylinder with reduced water volume. The MRgHIFU breast coil was comprised of a 10-channel phased array coil placed around an MRgHIFU treatment cylinder where nearest-neighbor decoupling was achieved with capacitive decoupling in a shared leg. In addition a single loop coil was placed at the chest wall making a total of 11 channels. The radio frequency coil array design presented in this work was chosen based on ease of implementation, increased visualization into the treatment cylinder, image reconstruction speed, temporal resolution, and resulting signal-to-noise ratio profiles. This work presents a dedicated 11-channel coil for imaging of the breast tissue in the MRgHIFU setup without obstruction of the ultrasound beam and, specifically, compares its performance in signal-to-noise, overall imaging time, and temperature measurement accuracy to that of the standard single chest-loop coil typically used in breast MRgHIFU.

Evidence for a behavioral significance of saccular acoustic sensitivity in humans

In this article the results are reported of an experiment to provide direct evidence for a perceptual and behavioral significance of human saccular acoustic sensitivity. Ten human subjects were stimulated monaurally with 100-ms trains of 10-ms tone pulses with pulse repetition rate of 40 Hz, and were required to rate the pleasantness of the stimuli on a nine-point scale. The design included three within-subject factors: carrier frequency (two levels, 200 and 4,000 Hz), intensity [13 levels from 55 to 115 dB(A) in 5-dB steps] and ear (left and right). For intensities above 90 dB myogenic vestibular evoked potentials (MVEP) were also obtained from the ipsilateral sternocleidomastoid muscle from which it was possible to obtain thresholds by linear regression of MVEP amplitudes against intensity. A further between-subjects factor was added which assessed subjects' attitude to vestibular sensations. The results indicate that across subjects there is a general trend of decreasing pleasantness with increasing intensity, but for the 200-Hz condition there is a significant positive departure from monotonicity in pleasantness (p<0.05) above the mean saccular threshold. However, when split by the between-subjects factor, the positive departure was only evident for those subjects who have a positive attitude to vestibular sensations (p < 0.01). Implications of these results for human responses to loud sound and the possible evolutionary significance of saccular acoustic sensitivity are discussed.

Acute bronchopulmonary infection due to Streptococcus milleri in a child with cystic fibrosis

An 8 year old girl with cystic fibrosis had severe respiratory disease associated with chronic Pseudomonas aeruginosa bronchopulmonary infection. Despite regular courses of intravenous antipseudomonal antibiotics, she continued to deteriorate over 18 months with persistent productive cough, worsening respiratory function, and increasing oxygen dependence. During her 11th admission Streptococcus milleri was isolated from sputum cultures in addition to P aeruginosa. She failed to respond to antipseudomonal antibiotics but improved dramatically with the addition of intravenous benzylpenicillin. Although S milleri is considered a normal mouth commensal and its isolation from sputum of cystic fibrosis patients is of uncertain significance, it was associated with clinically significant infection in this child. S milleri was eradicated with antibiotic treatment and clinical improvement has been maintained.

The physiological knowledge required by nurses caring for patients with unstable angina

Physiological knowledge necessary to critically analyse nursing management of patients with unstable angina is reviewed. The role of endothelium derived relaxing factor, nitrous oxide and atherosclerosis is summarised. The effects of circadian rhythms or clinical signs and symptoms in patients with unstable angina is particularly highlighted. Pharmacological interventions are considered from the perspective of implications for nursing care and other important nursing interventions identified for coronary care nurses.

Pineal tumours in the north of England 1968-93

The records of 38 patients under 25 years of age presenting with pineal tumours between 1968 and 1993, identified from the Northern Region Children's and Young Adults' Malignant Disease Registry, were analysed retrospectively with regards to clinical presentation, diagnostic approach, treatment strategy, and outcome. The overall five year survival was 45%. Fifteen patients had a histological diagnosis: six with germinomas, three with teratomas, three with astrocytomas, and three with pinealoblastomas. One patient had a definitive diagnosis of teratoma made on the basis of raised tumour markers (alpha fetoprotein). Treatment consisted of surgery (87%) (ventriculoperitoneal or atrial shunt and/or biopsy), and/or radiotherapy (82%), and/or chemotherapy (26%). Those patients with a tissue diagnosis appeared to have a more favourable outcome, especially after 1976 when treatment was determined by tumour type (five year survival for those with a tissue diagnosis was 91% v 51% for those without, 95% confidence intervals 74 to 100% and 26 to 75%). This study suggests that tissue diagnosis allows more appropriate treatment to be delivered for children with pineal tumours resulting in improved survival. Referral to a centre with neurosurgery, radiotherapy, neuropathology, and paediatric oncology collaboration is essential.

A new selective differential medium for isolation of Stenotrophomonas maltophilia

A new selective differential medium for the isolation of Stenotrophomonas (formerly Xanthomonas) maltophilia was developed. The medium, VIA agar, contained vancomycin, imipenem, and amphotericin B as selective agents and incorporated a mannitol/bromothymol blue indicator system. Compared with Xanthomonas maltophilia Selective Medium (XMSM), VIA agar was less inhibitory to Stenotrophomonas maltophilia and was more selective than XMSM in preventing the growth of unwanted bacteria from contaminated specimens. Although vancomycin-resistant strains of Enterococcus faecium may grow on VIA agar, these can be easily distinguished from Stenotrophomonas maltophilia because of mannitol fermentation.

An auditory cortical theory of primitive auditory grouping

Auditory stream segregation is considered from the point of view of a theory of the central auditory system in which temporal information is spatially coded on three dimensions roughly corresponding to the level of the cochlea, the inferior colliculus and the auditory cortex, respectively. This theory is embodied in the form of a computational model which simulates peripheral and central processing including a cortical cross-channel correlation mechanism.

Molecular epidemiology of ceftazidime resistant Enterobacteriaceae from patients on a paediatric oncology ward

Between the autumn of 1989 and January 1990, 21 of the 44 children on the paediatric oncology ward of St. James's University Hospital, Leeds, UK were infected or colonised with Enterobacteriaceae producing extended-spectrum beta-lactamases. This represents 48% of the patients on the ward. Only six patients (14%) had microbiologically proven septicaemia caused by such bacteria during this period. Eighty-one isolates of Enterobacteriaceae producing extended-spectrum beta-lactamases derived from blood culture (7 isolates from 6 patients) or faecal samples (74 isolates) were available for examination. These comprised 28 Escherichia coli, 28 Klebsiella oxytoca, 11 Klebsiella pneumoniae, 10 Citrobacter freundii, 3 Enterobacter spp. and 1 Serratia marcescens. Clinical isolates were resistant to penicillins and to ceftazidime. Strains isolated in this study also showed multiple resistance to a range of antimicrobial agents. Transfer to a nalidixic acid resistant laboratory strain of E. coli UB5201 was attempted, but transfer of the ceftazidime resistance determinant was only successful in 25 isolates (31%). Examination of plasmid DNA revealed sequences in each isolate that hybridised with the TEM beta-lactamase gene probe used on a variety of plasmids ranging in size from 2.5- > 150 kb, sometimes found on several replicons in a single isolate. The TEM gene probe also hybridised with chromosomal DNA in a large number of isolates. Nucleotide sequence analysis demonstrated the presence of three extended-spectrum beta-lactamases: TEM-10B produced by two isolates, TEM-12B produced by 37 isolates and TEM-26B produced by 40 isolates. In two cases, isolates produced two beta-lactamases, and it proved impossible to identify these enzymes unequivocally. The genes encoding TEM-10B and TEM-26B both differ from TEM-12B by single nucleotide substitutions. Analysis of the ribotype patterns derived from the clinical isolates provided evidence for cross-colonisation between patients, and this was confirmed by analysis of the plasmid profiles. Four years after discontinuing ceftazidime and other extended-spectrum cephalosporins on this ward, patients were still colonised with bacteria that produced extended-spectrum beta-lactamases.

A comparison of molecular clearance rates during continuous hemofiltration and hemodialysis with a novel volumetric continuous renal replacement system

We developed a continuous, volumetrically controlled veno-venous renal replacement system that can be operated in filtration or dialysis modes. We compared the clearances of substances with a range of molecular weights (MW) in each mode. Ten patients with acute renal failure underwent serial postdilutional hemofiltration and hemodialysis, for 30 min each, in sequence and in randomized order. All were receiving vancomycin for concurrent sepsis. The system incorporated a Filtral 10 AN69 artificial kidney; blood flow rate was 200 ml/min, and dialysate/filtrate flow rate was 25 ml/min. Sieving (SC) and diffusion (DC) co-efficients, for hemofiltration and hemodialysis, respectively, were identical for urea (MW 60; 1.01 +/- 0.05 vs 1.01 +/- 0.07) and creatinine (MW 113; 1.00 +/- 0.09 vs 1.01 +/- 0.06), and clearance equated with dialysate/filtrate flow. There was a modest difference in uric acid clearance (MW 168; SC 1.01 +/- 0.04 vs DC 0.97 +/- 0.04; p < 0.05). Vancomycin (MW 1,800) removal was 19% greater during filtration compared with dialysis (SC 0.87 +/- 0.10 vs DC 0.74 +/- 0.06; p < 0.01). For small solutes, the two modalities were equivalent. Vancomycin clearance was appreciably greater with hemofiltration, which is consistent with a greater potential for convection-based therapy in the removal of uremic and other middle molecules.

Convergent evolution of TEM-26, a beta-lactamase with extended-spectrum activity

TEM-26, an extended-spectrum beta-lactamase has been characterized in clinical isolates of Klebsiella pneumoniae and Escherichia coli derived from patients on the Paediatric Oncology Unit of St James's University Hospital, Leeds. The nucleotide sequence of this beta-lactamase gene (blaTEM26b) was determined, and compared with the nucleotide sequences of other TEM-type beta-lactamases. The blaTEM26b gene was found to differ from blaTEM12b by a single nucleotide. This difference causes the substitution of glutamic acid in blaTEM12b for lysine in blaTEM26b at position 102 in the predicted amino acid sequence. The blaTEM12b gene was first described in an isolate of Klebsiella oxytoca from a patient nursed on the same unit that yielded the strains that carry blaTEM26b. However, the blaTEM26b gene differs at no less than six nucleotides from the nucleotide sequence encoding the TEM-26 beta-lactamase that was first described in isolates from cancer patients nursed in the Children's Hospital, Stanford, California, USA. This indicates that the genes encoding TEM-26 have evolved from different progenitors.

Transposition of the gene encoding a TEM-12 extended-spectrum beta-lactamase

An isolate of Klebsiella oxytoca from the blood culture of a child with leukemia was found to produce two beta-lactamases, at least one of which conferred resistance to ceftazidime. Genes encoding both enzymes were located on a single self-transmissible 100-kb plasmid, pOZ201. This plasmid was introduced into Escherichia coli UB5201 (pACYC184), and the gene encoding one beta-lactamase was transposed onto plasmid pACYC184 by exploiting a gene dosage effect. The transposable gene was found to encode a TEM-12 enzyme as determined by nucleotide sequencing. This gene was subsequently transposed onto plasmid pUB307. The transposable element encoding the TEM-12 enzyme has been designated Tn841. Both plasmids pACYC184::Tn841 and pUB307::Tn841 were shown to encode a beta-lactamase with the same isoelectric point and substrate profile as the TEM-12 beta-lactamase. Transposon Tn841, at approximately 7 kb, is larger than TnA (4.8 kb) and transposes at a lower frequency. Although it produced a resolvase which can complement the resolvase of Tn3, its transposase function was not able to complement the transposition of a TnA element which lacked transposase. The occurrence of a gene encoding an extended-spectrum beta-lactamase on a transposable element in a clinically significant bacterium is potentially a cause for concern for the spread of resistance to the extended-spectrum cephalosporins.

The epidemiology of Salmonella in calves: the role of markets and vehicles

Environmental contamination has been shown to be an important aspect of the epidemiology of salmonellosis in calves. Markets and transport vehicles are important links in the calf marketing chain and these were investigated to determine the level of salmonella contamination. Salmonellas were isolated from 7 of the 14 markets surveyed, with 31 of 838 samples (3.7%) being positive. Nine different salmonella serotypes, of which the commonest was Salmonella typhimurium, were isolated. Four different phage types of S. typhimurium were detected, the commonest being DT204C. Salmonellas were isolated from 22 of the 107 vehicles (20.6%) examined before washing and from 4 of the 62 vehicles (6.5%) examined after cleaning. Twelve different salmonella serotypes were isolated, of which the most frequent was S. typhimurium. The commonest of the six different S. typhimurium phage types was DT204C. These results indicate that improved cleaning and disinfection routines both for vehicles and markets are necessary to control salmonellosis in calves.

Epilepsy and the blood-brain barrier

Epilepsy is a common condition which is often resistant to therapy and may cause neurological damage. It is postulated that changes in blood-brain barrier function may be involved in the pathophysiology of both problems.

The epidemiology of Salmonella infection of calves: the role of dealers

Salmonellas were detected in the environment of 10 of the 12 calf dealers' premises studied. The cleaning and disinfection routines were often ineffective and salmonellas were isolated from 7.6% and 5.3% of the wall and floor samples before disinfection and 6.8% and 7.6% afterwards. Eight different salmonella serotypes were detected, of which the commonest were Salmonella typhimurium, predominantly phage type DT204C, and S. dublin. Plasmid profiles were used to fingerprint S. typhimurium DT204C and the results indicated that with the exception of one of the premises, prolonged salmonella-persistence in the environment was not occurring. Three separate epidemics of salmonellosis in calves were studied by use of plasmid profile analysis. The results illustrated the role of delers, and their subcontractors, in the dissemination of salmonellas. The study concludes with suggestions for methods to reduce the spread of salmonellas in the calf marketing chain.

A double-blind comparative study of remoxipride and thioridazine in the acute phase of schizophrenia

Sixty-one patients with acute schizophrenia received either remoxipride (75-375 mg daily) or thioridazine (150-750 mg daily) for 6 weeks. There was no statistically significant between-drug difference in improvement in mental state, as measured by the Brief Psychiatric Rating Scale, although the trend favoured thioridazine; global assessment of illness severity at the last rating also favoured thioridazine. Sedation, anticholinergic effects, autonomic dysfunction, and weight gain were significantly more common in patients receiving thioridazine. Both drugs produced few extrapyramidal effects, but both were associated with cardiovascular changes in two patients; neither drug produced significant abnormalities in laboratory tests.

Direct isolation of coagulase-negative staphylococci from neonatal blood samples

Coagulase-negative staphylococci (CNS) were isolated by direct inoculation of anticoagulated whole blood onto agar from 14 (41.2%) of 34 episodes (30 neonates) of suspected bacterial infection, associated with isolation of CNS from the same blood sample by broth-dilution blood cultures. The equivalent of more than 1,000 cfu ml-1 were isolated from four samples (four neonates); the range of counts was 1-103 cfu 25 microliters-1. There was a statistically significant association between isolation of CNS by direct agar inoculation and a raised C-reactive protein level and/or a positive nitroblue tetrazolium test and with the use of an intravascular catheter when compared to those episodes where CNS were isolated from broth blood cultures only. This simple procedure provides an estimate of the number of CNS in the blood of a neonate with suspected bacteraemia and may help to corroborate a diagnosis of CNS bacteraemia.

Aerosol infection of calves and mice with Salmonella typhimurium

The likelihood of airborne spread and infection by Salmonella typhimurium was studied in calves and mice. S typhimurium survived in air sufficiently long to present a significant hazard of airborne spread. In a dry climate (32 per cent relative humidity) its predicted viability five minutes after aerosolization was 4 per cent relative to its initial value. This increased to 24.8 per cent in a humid atmosphere (72 per cent relative humidity). Inhalation of S typhimurium by mice caused disease and death at times dependent upon the dose. Even the lowest dose of about 150 colony forming units (cfu) produced disease. Inoculation of approximately 10(4) to 10(6) cfu S typhimurium by either 'mouth and nose only' or 'whole body' aerosol exposure caused infection in calves. The consequences for the control of salmonellosis in intensive calf husbandry are discussed in the light of this demonstration that airborne transmission can be a primary mode of infection of S typhimurium.

A double blind comparative study of remoxipride and thioridazine in the acute phase of schizophrenia

This is the first comparative double blind study of remoxipride. Sixty-one patients with acute schizophrenia received either remoxipride (75-375 mg daily) or thioridazine (150-750 mg daily) for 6 weeks. There was no statistically significant between-drug difference in improvement in mental state, as measured by the Brief Psychiatric Rating Scale, although the trend favoured thioridazine; global assessment of illness severity at the last rating also favoured thioridazine. Sedation, anticholinergic effects, autonomic dysfunction and weight gain were significantly more common in patients receiving thioridazine. Both drugs produced few extrapyramidal effects, but both produced cardiovascular changes in two patients; neither drug produced significant abnormalities in laboratory tests.

Toxicity and mutagenicity of 6 anti-cancer drugs in Chinese hamster V79 cells co-cultured with rat hepatocytes

Toxicity and induction of 6-thioguanine-resistant mutants in Chinese hamster V79 cells, co-cultured with or without isolated rate hepatocytes, by 6 anti-cancer drugs (cyclophosphamide, adriamycin, methotrexate, cytosine arabinoside, 6-mercaptopurine and vincristine) were studied. The effect of hepatocyte density on the cloning efficiency and recovery of mutants was found using dimethylnitrosamine as a positive control. In the absence of hepatocytes, this compound was neither toxic nor mutagenic to V79 cells, but in their presence it was highly mutagenic and extremely toxic. The cloning efficiency and mutation frequency of control (untreated) cells was unaffected by hepatocyte density. All the drugs were toxic to V79 cells, although different responses were found for certain of them depending upon whether hepatocytes were present or not. Cyclophosphamide and adriamycin were clearly mutagenic, and 6-mercaptopurine only weakly so. A slight mutagenic effect was seen for cytosine arabinoside, but both methotrexate and vincristine were negative. Here also, the presence or absence of hepatocytes was important.

Presence of neuropeptide Y in human circle of Willis and its possible role in cerebral vasospasm

Neuropeptide Y (NPY) has been demonstrated in the human circle of Willis by specific radioimmunoassay. Concentrations were similar in cadaver and peroperative specimens. NPY concentrations were highest around the basilar bifurcation (2.9 +/- 1.0 pmol/g), anterior cerebral artery (2.7 +/- 0.5 pmol/g), and carotid trifurcation (2.4 +/- 0.6 pmol/g). Concentrations were lowest in the basilar artery (1.0 +/- 0.4 pmol/g). Intracarotid administration of NPY (50 pmol to 2 nmol) to rats reduced mean cerebral cortical blood flow by 40-98%. This vasoconstriction lasted for at least 2 h. These findings suggest that NPY may be involved in the cerebral vasospasm which follows subarachnoid haemorrhage and in the maintenance of normal vascular tone.

Bacteriology and treatment of purulent nasopharyngitis: a double blind, placebo-controlled evaluation

One hundred forty-two children with purulent nasopharyngitis were randomized to four treatment groups with an antibiotic (cephalexin) alone or combined with a decongestant/antihistamine (pseudoephedrine/triprolidine) or their corresponding placebo equivalents. Follow-up evaluations by parents and physicians and bacteriologic evaluations were performed after 5 to 6 days of therapy. Groups were comparable with regard to age, sex, race, number of patients withdrawn from the study, fever greater than 38.0 degrees C, appearance of nasal discharge, nasal crusting and number of days until follow-up. Initial cultures from patients grew: Streptococcus pneumoniae, 46%; Haemophilus influenzae type b, 21%; and Streptococcus pyogenes, 8%. Nasal crusting was significantly associated with the growth of S. pneumoniae or H. influenzae type b. There were no significant differences between active drug and placebo treatment groups for change in nasal discharge, complications or apparent drug benefit. Cephalexin therapy did not result in a decrease in cultivation of pathogenic organisms from the nasopharynx. Significantly more side effects were attributed to pseudoephedrine/triprolidine treatment than to placebo. Routine culture or treatment of purulent nasopharyngitis should not be considered unless future controlled clinical trials demonstrate some therapeutic benefit.

Fatal fat embolism during ritual initiation

A young Coast Salish Indian woman became fatally ill during ritual Initiation into the Native Winter Spirit Dancing Society. She died from massive fat emboli associated with subcutaneous bruises that appeared clinically unimportant and were not associated with fractures or other underlying injury. The liver showed extreme fatty metamorphosis.