T helper cell regulation of normal and neoplastic B cell growth

Following challenge with a thymus-dependent antigen T helper cells regulate B cell growth and differentiation in several ways. Initially, the T cells physically associate with antigen presenting B cells. While in conjugate, the two cells communicate with each other through the actions of cell surface receptors whose ligands are integral membrane proteins expressed on the surface of the apposed cell. The ensuing biochemical pathways regulate the expression of genes required for B cell cycle progression. As a consequence of this interaction, the T cells are induced to synthesize and secrete soluble mediators that also affect B cell proliferation, as well as determining the ultimate fate of the activated B cell. We also suggest a role for normal, Th cells during the development, and continued expansion of certain types of B cell lymphomas.     

Peripartum pubic symphysis separation: a case series and review of the literature

Peripartum pubic symphysis separation is a recognized complication of pregnancy with incidence estimates ranging from 1:300 to 1:30,000. Characteristic symptoms of symphyseal separation include suprapubic pain and tenderness with radiation to the back of legs, difficulty ambulating, and occasionally, bladder dysfunction. Clinical history, presenting symptoms, and response to therapy are sufficient to make the diagnosis, although radiographic documentation of symphyseal separation by x-ray or ultrasound are frequently used to confirm the diagnosis. The underlying etiology of symptomatic symphyseal separation has not been fully elucidated. Associations with multiparity, macrosomia, pathological joint loosening, and increased force placed on the pelvic ring have been suggested as possible etiologies. Conservative therapy, including bedrest, pelvic binders, ambulation devices, and mild analgesics usually result in a complete recovery with 4 to 6 weeks. The occurrence of a symphyseal separation should not significantly alter the management of subsequent pregnancies, and conservative therapy is recommended for any recurrence of symptoms. A retrospective review of our experience with 5121 deliveries from 1994 to 1995 found 9 cases of peripartum symphyseal separation, resulting in an incidence of 1 of 569 deliveries. Details regarding this case series and a review of the literature are presented.     

Deep inelastic neutron scattering from liquid4He in aerogel glass

We report highQ inelastic neutron scattering studies of liquid⁴He confined inside porous aerogel glass in both the normal and superfluid phases. The scattering consists of a broad component, which we interpret as due to atoms localized on the surface of the glass, and a narrow component, which we interpret as due to the confined liquid inside the pores. The broad component is quite small, and no quantitative analysis is attempted. However, the narrow component due to the confined liquid is sufficiently large that information on the kinetic energy and condensate fraction may be obtained. The measurements are at large enoughQ (23 Å^–1) that the incoherent approximation may be used to directly extract the kinetic energy. Furthermore, the observed scattering is consistent with the impulse approximation, allowing information on both the momentum distribution and the condensate fraction to be extracted. The kinetic energy of the confined liquid is close to previous measurements of the kinetic energy in the bulk liquid. The condensate fraction of the confined liquid, which is estimated using a modification of a method due to Sears, is close to previous estimates of the condensate fraction in the bulk liquid.     

O-GlcNAcylation of key nuclear and cytoskeletal proteins: reciprocity with O-phosphorylation and putative roles in protein multimerization

BACKGROUND: Registered mortality from cryptogenic fibrosing alveolitis (CFA) in England and Wales has increased substantially since the specific International Classification of Diseases code for CFA was introduced in 1979. However, since a significant proportion of deaths from CFA are misclassified as post inflammatory fibrosis (PIF), it is possible that the observed rise in CFA mortality is due to diagnostic transfer from this code. To investigate this, and to assess mortality trends in other countries, annual CFA and PIF mortality data from England and Wales, USA, Australia, Scotland, Canada, New Zealand, and Germany were analysed. METHODS: Crude annual mortality rates were calculated and rates standardised by Poisson regression to allow assessment of changes over time and comparison between countries, sexes, and age groups. The relative trends in mortality from CFA and PIF were assessed by calculating the annual ratio of CFA to PIF deaths. RESULTS: Men were more likely than women to die from both CFA and PIF in all countries. The highest standardised CFA mortality rate occurred in England and Wales, and the lowest in Germany. Since 1979 mortality from CFA has increased in England and Wales, Australia, Scotland and Canada, but there was no trend in CFA mortality in New Zealand or Germany. In the USA mortality from CFA was low and has fallen. Mortality from PIF increased in all countries except New Zealand and Germany, and the highest PIF mortality, together with the greatest increase over time, was seen in the USA. Changes over time in the annual ratio of CFA to PIF deaths in all countries were small, implying that diagnostic transfer is not a major cause of the increasing CFA mortality. CONCLUSIONS: Mortality from CFA continues to increase in England and Wales and in many other countries. Diagnostic transfer from PIF does not appear to be a major cause of this.     

The challenge of accurate software project status reporting: a two-stage model incorporating status errors and reporting bias

Software project managers perceive and report project status. Recognizing that their status perceptions might be wrong and that they may not faithfully report what they believe, leads to a natural question-how different is true software project status from reported status? Here, the authors construct a two-stage model which accounts for project manager errors in perception and bias that might be applied before reporting status to executives. They call the combined effect of errors in perception and bias, project status distortion . The probabilistic model has roots in information theory and uses discrete project status from traffic light reporting. The true statuses of projects of varying risk were elicited from a panel of five experts and formed the model input. The same experts estimated the frequency with which project managers make status errors, while the authors created different bias scenarios in order to investigate the impact of different bias levels. The true status estimates, error estimates, and bias levels allow calculation of perceived and reported status. The results indicate that at the early stage of the development process most software projects are already in trouble, that project managers are overly optimistic in their perceptions, and that executives receive status reports very different from reality, depending on the risk level of the project and the amount of bias applied by the project manager. Key findings suggest that executives should be skeptical of favorable status reports and that for higher risk projects executives should concentrate on decreasing bias if they are to improve the accuracy of project reporting.     

Fertilization stimulates an increase in inositol trisphosphate and inositol lipid levels in Xenopus eggs

Previous experiments from our lab have suggested that the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2) is required for sperm-induced egg activation in Xenopus laevis. Here we measure the endogenous production of both Ins(1,4,5)P3 and PIP2 during the sperm-induced and ionomycin-induced calcium wave in the egg and find that both increase following fertilization. Ins(1,4,5)P3 increases 3.2-fold from an unfertilized egg level of 0.13 pmole per egg (0.29 microM) to a peak of 0.42 pmole per egg (0.93 microM) as the calcium wave reaches the antipode in the fertilized egg. This continuous production of Ins(1,4,5)P3 during the time that the Ca2+ wave is propagating across the egg suggests the involvement of Ins(1,4,5)P3 in wave propagation. This increase in Ins(1,4,5)P3 is smaller in ionomycin-activated eggs than in sperm-activated eggs, suggesting that the sperm-induced production of Ins(1,4,5)P3 involves a PIP2 hydrolysis pathway that is not simply raising intracellular Ca2+. While one might expect PIP2 levels to fall as a result of hydrolysis, we find that PIP2 actually increases 2-fold. The total lipid fraction in unfertilized egg exhibits 0.8 pmole PIP2 per egg and this increases to 1.5 pmole as the calcium wave reaches the antipode. The PIP2 concentration peaks 2 min after the completion of the calcium wave at 1.8 pmole per egg. The amount of PIP2 in the animal and vegetal hemispheres of the egg was also measured by cutting frozen eggs in half. The vegetal hemisphere contained twice the amount of PIP2 as the animal hemisphere but it also contained twice the amount of lipid. Thus, there was an equivalent amount of PIP2 normalized to lipid in each hemisphere. Isolated animal and vegetal hemisphere cortices exhibit similar PIP2 concentrations, suggesting that the 2-fold higher total PIP2 in the vegetal half is not due to a gradient of PIP2 in the plasma membrane, but rather implies that cytoplasmic organelle membranes also contain PIP2.     

A multi-protocol campus time server

A time server system has been constructed at the University of Newcastle upon Tyne which may be accessed by users of the campus Ethernet. It uses a commercially available radio clock to receive an accurate time signal from the MSF transmitter at Rugby, and can respond to requests from users of the network using a number of different protocols. This paper describes the server system, both hardware and software, and discusses some network management issues raised as a result of the associated experimentation and testing of the system.     

Fragment detection system for studies of exotic neutron-rich nuclei

We have developed a fragment detection system for use in studies of exotic, neutron-rich nuclei. Using a C-shaped dipole magnet, the system sweeps charged fragments and un-reacted beam particles through an angle before stopping them in an array of plastic scintillator detectors, recording time-of-flight and total energy. The system also includes a pair of silicon strip detectors to measure fragment angle of emergence from the target and energy loss for particle identification.     

Conversational discourse abilities following severe traumatic brain injury: a follow-up study

The major aim of this study was to describe the conversational abilities of a group of severely injured TBI speakers, at a minimum of 2 years post-injury. The association between conversational impairment and (a) selected measures of executive function and (b) psychosocial handicap was also examined. Twenty-four members of the group of 26 severely injured TBI speakers who had initially been assessed between 3 and 6 months post-injury were reviewed at a minimum of 2 years post-injury (mean = 2 years, 10 months). At initial assessment, TBI speakers were compared with non-TBI orthopaedic patients and with a group of university students. At follow-up, however, they were compared only with the orthopaedic patients. Conversational assessment was carried out using a modified form of Damico's Clinical Discourse Analysis. As a group, the TBI speakers' conversational abilities did not improve over time. There was, however, a subgroup (n = 8) of speakers who did improve, and these could be distinguished by greater initial severity of injury and a significantly longer period of speech-language pathology intervention than the speakers who either remained the same or worsened over time. Modest associations between conversational discourse skills and measures of executive function and a measure of psychosocial handicap were identified. These findings indicate that disruptions in conversation persist into the longer term. More assiduous efforts may need to be made to (a) identify subtle discourse changes in the early months after injury and (b) engage TBI speakers in speech-language pathology services. Such services are also required over a longer time frame, in community-based models of service provision.     

Congenitally cleft atrioventricular valves associated with secundum atrial septal defects

Three patients with the rare association of secundum ASD and congenital clefts of A-V valves are reported. These three patients illustrate the predictive valve of vectoracardiographic analysis in precisely determining the anatomic location of the valvular pathology. The embryologic origins of the lesion are briefly discussed. A review of the literature supports the use of vector analysis in the evaluation of the patients with this type of heart disease.