Measurement of the WW production cross section in pp collisions at square root[s]=1.96 TeV

We present a measurement of the W boson pair-production cross section in pp collisions at a center-of-mass energy of sqrt[s]=1.96 TeV. The data, collected with the Run II D0 detector at Fermilab, correspond to an integrated luminosity of 224-252 pb(-1) depending on the final state (ee, emu, or mumu). We observe 25 candidates with a background expectation of 8.1+/-0.6(stat)+/-0.6(syst)+/-0.5(lum) events. The probability for an upward fluctuation of the background to produce the observed signal is 2.3x10(-7), equivalent to 5.2 standard deviations. The measurement yields a cross section of 13.8(+4.3)(-3.8)(stat)+1.2-0.9(syst)+/-0.9(lum) pb, in agreement with predictions from the standard model.

Measurement of the Lambda0b lifetime in the decay lambda0b--> J/psiLambda0 with the D0 detector

We present measurements of the Lambda(0)(b) lifetime in the exclusive decay channel Lambda(0)(b)--> J/psiLambda(0), with J/psi--> mu(+)mu(-) and Lambda(0)--> ppi(-), the B0 lifetime in the decay B0-->J/psiK(0)(S) with J/psi--> mu(+)mu(-) and K(0)(S)-->pi(+)pi(-), and the ratio of these lifetimes. The analysis is based on approximately 250 pb(-1) of data recorded with the D0 detector in pp collisions at sqrt[s] = 1.96 TeV. The Lambda(0)(b) lifetime is determined to be tau(Lambda(0)(b)) = 1.22(+0.22)(-0.18)(stat) +/- 0.04(syst) ps, the B0 lifetime tau(B0) = 1.40(+0.11)(-0.10)(stat) +/- 0.03(syst) ps, and the ratio tau(Lambda(0)(b))/tau(B0) = 0.87(+0.17)(-0.14)(stat) +/- 0.03(syst). In contrast with previous measurements using semileptonic decays, this is the first determination of the Lambda(0)(b) lifetime based on a fully reconstructed decay channel.

Search for Wbb and WH production in pp collisions at square root [s]=1.96 TeV

We present a search for Wbb production in pp collisions at sqrt[s]=1.96 TeV in events containing one electron, an imbalance in transverse momentum, and two b-tagged jets. Using 174 pb(-1) of integrated luminosity accumulated by the D0 experiment at the Fermilab Tevatron collider, and the standard-model description of such events, we set a 95% C.L. upper limit on Wbb production of 6.6 pb for b quarks with transverse momenta p(b)(T)>20 GeV and bb separation in pseudorapidity-azimuth space DeltaR(bb)>0.75. Restricting the search to optimized bb mass intervals provides upper limits on WH production of 9.0-12.2 pb for Higgs-boson masses of 105-135 GeV.

Search for the flavor-changing neutral current decay B0s--> mu(+) mu(-) in pp Collisions at sqrt[s] = 1.96 TeV with the D0 detector

We present the results of a search for the flavor-changing neutral current decay B(0)(s)--> mu(+) mu(-) using a data set with integrated luminosity of 240 pb(-1) of pp collisions at sqrt[s] = 1.96 TeV collected with the D0 detector in run II of the Fermilab Tevatron collider. We find the upper limit on the branching fraction to be B(B(0)(s)--> mu(+) mu(-)) < or= 5.0 x 10(-7) at the 95% C.L. assuming no contributions from the decay B(0)(d)--> mu(+) mu(-) in the signal region. This limit is the most stringent upper bound on the branching fraction B(0)(s)--> mu(+) mu(-) to date.

Search for supersymmetry with gauge-mediated breaking in diphoton events at D0

We report the results of a search for supersymmetry (SUSY) with gauge-mediated breaking in the missing transverse energy distribution of inclusive diphoton events using 263 pb(-1) of data collected by the D0 experiment at the Fermilab Tevatron Collider in 2002-2004. No excess is observed above the background expected from standard model processes, and lower limits on the masses of the lightest neutralino and chargino of about 108 and 195 GeV, respectively, are set at the 95% confidence level. These are the most stringent limits to date for models with gauge-mediated SUSY breaking with a short-lived neutralino as the next-to-lightest SUSY particle.

Measurement of the B0s lifetime in the exclusive decay channel B0s-->J/psiphi

Using the exclusive decay B0s-->J/psi(mu+mu-)phi(K+K-), we report the most precise single measurement of the B0s lifetime. The data sample corresponds to an integrated luminosity of approximately 220 pb(-1) collected with the D0 detector at the Fermilab Tevatron Collider in 2002-2004. We reconstruct 337 signal candidates, from which we extract the B0s lifetime, tau(B0s)=1.444(+0.098)(-0.090)(stat)+/-0.020(sys) ps. We also report a measurement for the lifetime of the B0 meson using the exclusive decay B0-->J/psi(mu+mu-)K*0(892)(K+pi-). We reconstruct 1370 signal candidates, obtaining tau(B0)=1.473(+0.052)(-0.050)(stat)+/-0.023(sys) ps, and the ratio of lifetimes, tau(B0s)/tau(B0)=0.980(+0.076)(-0.071)(stat)+/-0.003(sys).

Molecular characterisation of fructose transport in equine small intestine

REASONS FOR PERFORMING STUDY

Fructose can be a suitable carbohydrate supplement for horses before and/or during endurance exercise. In comparison to glucose, the ingestion of fructose results in a lower insulin peak and less marked fluctuations in blood glucose during exercise, potentially avoiding hypoglycaemia-induced exhaustion.

OBJECTIVES

To assess the capacity of the equine small intestine to absorb fructose and to determine the mechanism, molecular structure and properties of equine intestinal fructose transport.

METHODS

Using PCR-based strategies, RNA isolated from equine small intestine and primers designed to homologous regions of the fructose transporter, GLUT5, cDNA of other species, we cloned and sequenced equine GLUT5 (eGLUT5). Northern and western blot analyses, in conjunction with immunohistochemistry, utilising eGLUT5 cDNA and antibodies, assessed expression of eGLUT5 along the longitudinal and radial axes of the small intestine. Functional properties of fructose transport in intestinal brush-border membrane vesicles were measured using the rapid-filtration technique.

RESULTS

eGLUT5 is expressed in the villus enterocytes with highest levels in duodenum>jejunum and lowest in the ileum. Kinetic studies indicate eGLUT5 is a low affinity, high capacity transporter.

CONCLUSIONS

Equine small intestine has the capacity to absorb fructose.

POTENTIAL RELEVANCE

The molecular probes produced in these studies can be used as diagnostic aids to determine equine intestinal monosaccharide malabsorption.

Observation and properties of the X(3872) decaying to J/psipi(+)pi(-) in pp collisions at sqrt[s]=1.96 TeV

We report the observation of the X(3872) in the J/psipi(+)pi(-) channel, with J/psi decaying to mu(+)mu(-), in pp collisions at sqrt[s]=1.96 TeV. Using approximately 230 pb(-1) of data collected with the Run II D0 detector, we observe 522+/-100 X(3872) candidates. The mass difference between the X(3872) state and the J/psi is measured to be 774.9+/-3.1(stat)+/-3.0(syst) MeV/c(2). We have investigated the production and decay characteristics of the X(3872) and find them to be similar to those of the psi(2S) state.

Duration of stay and outcome for inpatients on an assessment ward for elderly patients with cognitive impairment

The move away from the provision of long‐stay beds by the NHS inevitably meant a change in function for wards for elderly patients with cognitive impairment to a more acute way of working. Literature is scarce on the role or effectiveness of the new assessment wards that have replaced them and the factors affecting outcome and the duration of stay. Evidence suggests that those patients with higher dependency levels and behavioural problems stay in hospital longer, as do those awaiting a nursing home placement.This paper reports a prospective study of a consecutive group of 101 patients who died on or were discharged from an acute assessment ward for elderly patients with cognitive impairment. Clinical characteristics were recorded according to an in‐patient dementia care pathway, which included Mini‐MOUSEPAD, Crichton activities of daily living, Mini‐Mental State Examination and the Burvill physical health score evaluations. Outcome measures were duration of stay, destination on discharge or death on the ward.Most patients had cerebrovascular disease (48%) or Alzheimer's disease (32.9%), and their average Mini‐Mental State Examination score was 14.9. The mean duration of stay was 7.9 weeks. Self‐funding status and lack of behavioural and psychological complications were associated with a reduced duration of stay. 22.2% of patients were successfully rehabilitated to their own homes, but 20% died. Discharge home was most strongly predicted by having a spouse at home, and the need for nursing home rather than residential care was related to the severity of cognitive impairment. This study concludes that patients can expect to stay in hospital for 8 weeks but two areas of concern are highlighted. Firstly, the importance of the funding of community rehabilitation for patients with memory disorders and, secondly, the importance of a spouse at home to look after the patient.

Search for doubly charged higgs boson pair production in the decay to mu(+)mu(+)mu(-)mu(-) in pp collisions at sqrt[s]=1.96 TeV

A search for pair production of doubly charged Higgs bosons in the process pp -->H(++)H(--) -->mu(+)mu(+)mu(-)mu(-) is performed with the D0 run II detector at the Fermilab Tevatron. The analysis is based on a sample of inclusive dimuon data collected at an energy of sqrt[s]=1.96 TeV, corresponding to an integrated luminosity of 113 pb(-1). In the absence of a signal, 95% confidence level mass limits of M(H(+/-+/-)(L))>118.4 GeV/c(2) and M(H(+/-+/-)(R))>98.2 GeV/c(2) are set for left-handed and right-handed doubly charged Higgs bosons, respectively, assuming 100% branching into muon pairs.

Activity-Dependent Regulation of Neurohormone Synthesis and Its Impact on Reproductive Behavior in Aplysia1

The bag cell neurons (BCNs) of the mollusk Aplysia californica provide a simple model system for investigating cellular and molecular events regulating synthesis and secretion of a reproductive neuropeptide and their impact on physiology and behavior. The BCNs secrete a large amount of egg-laying hormone (ELH) in response to an electrical afterdischarge. The afterdischarge also triggers cellular and molecular events leading to upregulation of ELH biosynthesis to replenish the supply of releasable hormone that was lost because of secretion. In the present review, we discuss signal-transduction events that link membrane excitability to ELH biosynthesis. We present evidence that the afterdischarge stimulates ELH synthesis by upregulating translation of ELH mRNA rather than by activating ELH gene transcription. This increase in ELH synthesis is accompanied by a decrease in total protein synthesis, suggesting that the synthetic machinery is being funneled selectively toward ELH. We also discuss work showing that afterdischarge-induced ELH synthesis uses a novel mechanism of translation initiation, one involving a switch from cap-dependent to cap-independent translation initiation that activates an internal ribosome entry site (IRES) located in the 5'-untranslated region of ELH mRNA. The IRES-regulated translation provides a unique cellular mechanism to selectively upregulate synthesis of a critical reproductive hormone at the expense of nonessential proteins.

Mechanism of glucose sensing in the small intestine

Sensing nutrients is a fundamental task for all living cells. For most eukaryotic cells glucose is a major source of energy, having significant and varied effects on cell function. Interest in identifying mechanisms by which cells sense and respond to variations in glucose concentration has increased recently. The epithelial cells lining the intestinal tract are exposed, from the luminal domain, to an environment with continuous and massive fluctuations in the levels of dietary monosaccharides. Enterocytes therefore have to sense and respond to the significant changes in the levels of luminal sugars, and regulate the expression of the intestinal glucose transporter (Na+/glucose co-transporter, SGLT1) accordingly. Our data, using a combination of in vivo and in vitro model systems, suggest that glucose in the lumen of the intestine is sensed by a glucose sensor residing on the external face of the enterocyte luminal membrane. Glucose binds to the sensor and generates an intracellular signal leading to enhancement in the expression of SGLT1. The generated signal is independent of glucose metabolism and is likely to operate via a G-protein-coupled receptor and cAMP/protein kinase A signalling cascade.

Molecular characterisation of carbohydrate digestion and absorption in equine small intestine

Dietary carbohydrates, when digested and absorbed in the small intestine of the horse, provide a substantial fraction of metabolisable energy. However, if levels in diets exceed the capacity of the equine small intestine to digest and absorb them, they reach the hindgut, cause alterations in microbial populations and the metabolite products and predispose the horse to gastrointestinal diseases. We set out to determine, at the molecular level, the mechanisms, properties and the site of expression of carbohydrate digestive and absorptive functions of the equine small intestinal brush-border membrane. We have demonstrated that the disaccharidases sucrase, lactase and maltase are expressed diversely along the length of the intestine and D-glucose is transported across the equine intestinal brush-border membrane by a high affinity, low capacity, Na+/glucose cotransporter type 1 isoform (SGLT1). The highest rate of transport is in duodenum > jejunum > ileum. We have cloned and sequenced the cDNA encoding equine SGLT1 and alignment with SGLT1 of other species indicates 85-89% homology at the nucleotide and 84-87% identity at the amino acid levels. We have shown that there is a good correlation between levels of functional SGLT1 protein and SGLT1 mRNA abundance along the length of the small intestine. This indicates that the major site of glucose absorption in horses maintained on conventional grass-based diets is in the proximal intestine, and the expression of equine intestinal SGLT1 along the proximal to distal axis of the intestine is regulated at the level of mRNA abundance. The data presented in this paper are the first to provide information on the capacity of the equine intestine to digest and absorb soluble carbohydrates and has implications for a better feed management, pharmaceutical intervention and for dietary supplementation in horses following intestinal resection.

Preventing falls in older people: charting practice change by audit

Before an audit project in one trust there was no formal means of assessing the risk of falling among older patients. By raising staff awareness and consulting on the best evidence available, a specific falls-risk assessment has been developed and is now widely used. Follow-up audits have demonstrated a change in practice which it is hoped will bring about a reduction in falls.

Expression of monosaccharide transporters in intestine of diabetic humans

Noninsulin-dependent diabetes mellitus (NIDDM) is an increasingly common disease, which brings a number of life-threatening complications. In rats with experimentally induced diabetes, there is an increase in the capacity of the intestine to absorb monosaccharides. We have examined the activity and the expression of monosaccharide transporters in the intestine of patients suffering from NIDDM. Na(+)-dependent D-glucose transport was 3.3-fold higher in brush-border membrane (BBM) vesicles isolated from duodenal biopsies of NIDDM patients compared with healthy controls. Western analysis indicated that SGLT1 and GLUT5 protein levels were also 4.3- and 4.1-fold higher in diabetic patients. This was associated with threefold increases in SGLT1 and GLUT5 mRNA measured by Northern blotting. GLUT2 mRNA levels were also increased threefold in the intestine of diabetic patients. Analysis of other BBM proteins indicated that the activity and abundance of sucrase and lactase were increased by 1.5- to 2-fold and the level of the structural proteins villin and beta-actin was enhanced 2-fold in diabetic patients compared with controls. The increase in the capacity of the intestine to absorb monosaccharides in human NIDDM is due to a combination of intestinal structural change with a specific increase in the expression of the monosaccharide transporters SGLT1, GLUT5, and GLUT2.

Transcriptional regulation of the ovine intestinal Na+/glucose cotransporter SGLT1 gene. Role of HNF-1 in glucose activation of promoter function

Dietary sugars D-glucose and D-galactose are transported across the intestinal brush-border membrane by the Na+/glucose cotransporter, SGLT1. In various species studied, it has been shown that the activity, and expression, of intestinal SGLT1 is regulated by dietary sugars. We report in this paper that regulation of the intestinal SGLT1 gene by lumenal sugar is due, in part, to an increase in transcription. Using deletion analyses of the -66/+21-bp fragment, we have identified the minimal region of the ovine SGLT1 promoter able to support transcription. Site-directed mutagenesis of the hepatic nuclear factor-1 (HNF-1) consensus motif within this domain eliminates basal promoter function. In addition, we show direct evidence for glucose-induced activation of the -66/+21-bp promoter region. There is a co-ordinated decline in the abundance of ovine intestinal HNF-1 and SGLT1 transcripts during transition from preruminant to adult ruminant. This decline is recovered after glucose infusion of adult sheep intestine. Similarly, as shown using DNA mobility-shift assays, the intensity of the HNF-1-binding complex to the target promoter sequence decreases during maturation of the animal; this is restored after intestinal sugar infusion. These data indicate that HNF-1 plays an important role in the glucose responsiveness of the ovine SGLT1 gene. This is the first report of in vitro glucose-induced activation of the intestinal SGLT1 promoter and identification of a glucose-responsive region of the ovine SGLT1 promoter.

Expression of the Na+/glucose co-transporter (SGLT1) in the intestine of domestic and wild ruminants

The activity and abundance of the Na+/glucose co-transporter (SGLT1) was assessed in brush-border-membrane vesicles (BBMV) isolated from the intestine of grass- and roughage- (GR) consuming ruminants (sheep and dairy cattle), during the transition from the pre-ruminant to the mature ruminant state. The abundance of SGLT1 messenger ribonucleic acid (mRNA) was also compared in the intestinal tissue of the same animals. The dramatic developmental decline in the activity and expression of SGLT1 appears to be typical of GR-consuming ruminants and is coincident with the significant decline in the levels of lumenal monosaccharides. Expression of the ovine SGLT1 complementary deoxyribonucleic acid (cDNA) in Xenopus laevis oocytes confirmed that the isolated cDNA encodes for a functional Na+/glucose co-transporter. Determination of a bovine intestinal SGLT1 protein sequence (amino acids 347-658) indicated 99% similarity to the ovine SGLT1 protein with differences in the carboxyl terminus. In contrast to GR-consuming ruminants, the abundance of SGLT1 protein and SGLT1 mRNA remained significantly high in the intestine of ruminants in both the intermediate-mixed (IM) feeding goat and fallow deer and the concentrate-selecting (CS) moose and roe deer, dietary groups correlating with the availability of monosaccharides in the intestinal lumen.

Ultrasound assessment of the vulnerability of the internal organs to stabbing: determining safety standards for stab-resistant body armour

Stab-resistant body armour may not always prevent the passage of a blade into the human body. The depth to which a knife may 'safely' enter the human body before it breaches the internal organs was explored by ultrasound scanning of 25 healthy volunteers. Variations in the minimum skin-to-organ distances for the organs as a function of posture are described. To determine the optimum body coverage by stab-resistant armour, the movement during the breathing cycle and the maximum exposure of the organs beneath the lower costal margin at full inspiration were measured. Although the population studied was small, trends in the vulnerability of the internal organs to the passage of a blade into the body were identified.

Image-guided automated needle biopsy of 106 thoracic lesions: a retrospective review of diagnostic accuracy and complication rates

We reviewed the diagnostic accuracy and complication rates of transthoracic needle biopsy (TNB) with an automated 18-gauge core biopsy needle and gun, using either fluoroscopic or CT guidance. One hundred six lesions were biopsied in 103 patients between 1992 and 1998. Hard-copy images, imaging reports, pathology reports and clinical notes were reviewed. In 3 patients it was not possible to establish the lesion as either malignant or benign from the available follow-up, so these were removed from the analysis of diagnostic accuracy. Adequate samples for histological diagnosis were obtained in 104 of 106 (98%) biopsies. There were 75 of 85 (88%) true-positive core biopsies for malignant lesions and a specific cell type was identified in 70 of 85 (82%) cases. A specific histological diagnosis was obtained in 12 of 18 (66%) biopsies. There was a 19% rate of pneumothorax with only 2.4% requiring drainage. Minor haemoptysis occurred in 3.8% of procedures. The TNB technique with an automated core biopsy needle provides a high level of diagnostic accuracy, effectively distinguishes cell type in malignancy and provides a definite diagnosis in benign disease more frequently than fine needle aspiration (FNA). There is no increased complication rate compared with FNA.

Quantitation of human immunodeficiency virus type 1 RNA in different biological compartments

Little information is available describing viral loads in body fluids other than blood. In addition, the suitability of commercially available assays for human immunodeficiency virus type 1 (HIV-1) RNA quantitation has not been evaluated in most nonblood fluids. We compared Organon Teknika's nucleic acid sequence-based amplification method (NASBA) and Roche's Amplicor HIV-1 Monitor (reverse transcriptase PCR [RT-PCR]) for quantitating HIV-1 RNA in cerebrospinal fluid (CSF), saliva, breast milk, seminal plasma, and cervical-vaginal lavage fluid (CVL). Saliva and breast milk frequently demonstrated some inhibition in the RT-PCR assay, similar to the inhibition previously described in seminal plasma. Inhibition of the RT-PCR assay was not observed with CSF or CVL, nor in any of the NASBA assays. When fluids from HIV-infected individuals were tested by RT-PCR and NASBA, 73 and 27% of CSF samples and 60 and 40% of breast milk specimens had detectable RNA, respectively. These differences were not statistically significant. In cross-sectional studies using RT-PCR to measure viral RNA in paired blood plasma and CSF samples, 71% of blood plasma samples and 42% of CSF samples were positive. A similar analysis using NASBA with paired blood plasma and CVL, saliva, or seminal plasma samples revealed 91% were blood plasma positive and 55% were CVL positive, 76% were blood plasma positive and 46% were saliva positive, and 83% were blood plasma positive and 63% were seminal plasma positive. NASBA worked fairly well to quantitate HIV-1 RNA from all fluids without apparent inhibition. RT-PCR performed well on CVL and CSF, frequently with greater sensitivity, although its use in other fluids appears limited due to the presence of inhibitors. These studies demonstrate that viral loads in nonblood fluids were generally lower than in blood.

In birds, NHE2 is major brush-border Na+/H+ exchanger in colon and is increased by a low-NaCl diet

We previously reported that mammalian small intestinal and colonic brush borders (BBs) contained both epithelial Na+/H+ exchangers NHE2 and NHE3. We now show that, in the avian (chicken) colon, NHE2 is the major functional isoform under basal conditions and when stimulated by a low-NaCl diet. Hubbard chickens were maintained for 2 wk on a high- or low-NaCl diet. After the chickens were killed, the ileum and colon were removed, and BBs were prepared by Mg2+ precipitation and 22Na and D-[14C]glucose uptake determined in the BB vesicles. NHE2 and NHE3 were separated by differential sensitivity to HOE-694 (NHE2 defined as Na+/H+ exchange inhibited by 50 microM HOE-694). Chickens on a low-Na+ diet have increased plasma aldosterone (10 vs. 207 pg/ml). On the high-NaCl diet, both NHE2 and NHE3 contributed to ileal and colonic apical Na+/H+ exchange, contributing equally in ileum, but NHE2 being the major component in colon (86%). Low-NaCl diet significantly increased ileal and colonic BB Na+/H+ exchange; the increase in BB Na+/H+ exchange in both ileum and colon was entirely due to an increase in NHE2 with no change in NHE3 activity. In contrast, low-NaCl diet decreased ileal and colonic Na+-dependent D-glucose uptake. Western analysis showed that low-Na+ diet increased the amount of NHE2 in the ileal and colonic BB and decreased the amount of ileal Na+-dependent glucose transporter SGLT1. Both NHE2 and NHE3 were present in the apical but not basolateral membranes (BLM) of ileal and colonic epithelial cells. In summary, 1) NHE2 and NHE3 are both present in the BB and not BLM of chicken ileum and colon; 2) NHE2 is the major physiological colonic BB Na+/H+ exchanger under basal conditions; 3) low-NaCl diet, which increases plasma aldosterone, increases ileal and colonic BB Na+/H+ exchange and decreases Na+-dependent D-glucose uptake; 4) the stimulation of colonic BB Na+/H+ exchange is due to increased activity and amount of NHE2; and 5) the inhibition of ileal D-glucose uptake is associated with a decrease in SGLT1 amount. NHE2 is the major chicken colonic BB Na+/H+ exchanger.

Factors associated with changes in HIV shedding in semen

The efficiency and duration of transmissibilty of HIV seems to be highly variable and dependent on a number of factors related to both the donor and the recipient as well as characteristics intrinsic to the virus itself. Some of the factors likely to be important in sexual transmission of HIV include stage of disease, antiretroviral therapy, and concomitant systemic or mucosal infections, including sexually transmitted diseases. This paper describes recent work from our group in each of these areas.

Citrobacter sedlakii meningitis and brain abscess in a premature infant

Citrobacter sedlakii was isolated from blood and cerebrospinal fluid cultures of a 5-day-old premature infant with sepsis, meningitis, and brain abscess. This newly described organism was difficult to identify due to discrepancies between the Vitek and API 20E identification systems. To our knowledge, this is the first report of the isolation of C. sedlakii from cerebrospinal fluid.

Quantification of HIV in semen: correlation with antiviral treatment and immune status

OBJECTIVE

This study examined the concentration of HIV in semen and the effects of biological factors on HIV excretion.

METHODS

Semen samples from 101 men at different stages of the disease were evaluated by quantitative HIV culture and HIV RNA detection. Blood plasma samples were available from 56 patients. The effects of CD4 and CD8 count, blood plasma RNA levels, treatment status and clinical staging on the shedding of HIV were evaluated.

RESULTS

HIV RNA levels in semen correlated with quantitative HIV culture of seminal cells and a strong association of positive seminal cell culture with high RNA levels was observed. CD4 count and antiviral treatment were inversely correlated with the concentration of HIV in semen. Blood plasma HIV RNA values were correlated with HIV RNA levels in semen, although some patients had highly discrepant results.

CONCLUSIONS

The strong correlation between seminal cell culture and concentration of HIV RNA in seminal plasma suggested that HIV detected in seminal plasma was released by productively infected cells in the male genital tract. The study showed that the concentration of HIV in semen, which was likely to be correlated with HIV infectivity, was a function of the immune status of the HIV-infected individual. The results suggested that antiviral therapy may have reduced the concentration of HIV in semen.

Nutrient regulation of human intestinal sugar transporter (SGLT1) expression

BACKGROUND

The activity of most intestinal nutrient transporters is adaptively regulated by the type and amounts of nutrients entering the intestinal lumen. The concentration and activity of the intestinal Na+/glucose cotransporter (SGLT1) are regulated by dietary sugars in most animal species. The activity and abundance of SGLT1 in biopsy specimens removed from human jejunal regions exposed to, and having limited access to, luminal nutrients have been measured and compared.

AIMS

To study the effects of luminal nutrients on the expression of SGLT1 in the human intestine.

PATIENT AND METHODS

Brush border membrane vesicles (BBMV) were prepared from biopsy specimens removed from the intestine of a 50 year old man who had developed a high output jejunal fistula, and adjacent mucosal fistula, a condition present for 12 months after surgery for a strangulated hernia. BBMV prepared from intestine exposed to luminal nutrients, and from dysfunctional intestine with a limited exposure to nutrients, were used to measure Na+ dependent glucose transport and abundance of SGLT1 protein.

RESULTS

The levels of SGLT1 activity and abundance in the BBMV prepared from control biopsy specimens were similar to those found in BBMV prepared from the intestine of healthy individuals. BBMV from the dysfunctional intestine, exposed to limited levels of luminal nutrients, had reduced levels of SGLT1 activity. This reduction in SGLT1 activity and abundance was above that associated with any villus atrophy, as assessed by the abundance/activity of lactase and villin concentrations.

CONCLUSIONS

These data indicate that the activity and expression of SGLT1 in human intestine is maintained by the presence of luminal nutrients.

Controlling substance abuse. A narcotic audit tool

A medical center formed a narcotic task force because of widespread concern over misuse of drugs. Systems and staff issues were addressed. Audits to help identify and alleviate the problem were conducted; two narcotic audit tools are shown.

Nutrient regulation of the intestinal Na+/glucose co-transporter (SGLT1) gene expression

It is known that dietary carbohydrates regulate the activity of the intestinal SGLT1. We have demonstrated that modifications in SGLT1 activity are due to alterations in SGLT1 expression in response to the sugar content of the diet. To assess the correlation between changes in the activity of SGLT1 and the abundance of SGLT1 protein, we have employed a method for the quantitative measurement of immunoreactive proteins. A calibration curve has been constructed using either a nonadecapeptide (amino acids 402-420), or a recombinant protein corresponding to amino acids 554-640 of the SGLT1 sequence. Immunoblotting the protein samples concurrently with specific quantities of either the peptide or recombinant standard, using antibodies raised against these antigens, enabled accurate quantification of the absolute amounts of immunoreactive protein in the samples. The amount of SGLT1 protein correlates well with measurements of SGLT1 activity. The modulation of the activity of SGLT1 in response to lumenal sugars is due to corresponding changes in the absolute levels of SGLT1 protein.

Late deterioration after decompression illness affecting the spinal cord

A former amateur diver presented with a progressive paraparesis. Thirteen years previously he had developed acute spinal cord dysfunction immediately after dry hyperbaric exposure. He had completely recovered motor function in the intervening period. No alternative reason for the later decline emerged from detailed investigation.

Supporting children with cystic fibrosis in school

Children with cystic fibrosis need support to benefit from a normal education. Liaison between the specialist nurse and school staff--teachers and nurses--can enable the school to provide this support.

Accuracy of pelvic radiotherapy: prospective analysis of 90 patients in a randomised trial of blocked versus standard radiotherapy

The aim of this study was to assess the accuracy of pelvic radiotherapy during a trial of blocked radiotherapy at the Royal Marsden Hospital, UK. Prospective evaluation was performed on 90 patients receiving CT planned pelvic radiotherapy using weekly anterior-posterior and lateral portal films. Field placement errors (FPEs) were calculated by comparing field centres of each film with a designated point of interest. Data was evaluated to calculate the overall treatment simulator differences, the number of error free treatments, and mean treatment-simulator position and to evaluate the role of systematic versus random errors. Age, weight, disease site, position of treatment, fractionation, blocked versus conventional techniques were assessed for their effect on treatment accuracy. The mean absolute error between treatment and simulator films was anterior right-left (ARL) 0.25 cm, anterior superior-inferior (ASI) 0.32 cm, lateral anterior-posterior (LAP) 0.42 cm, and lateral superior-inferior (LSI) 0.28 cm. On average the field centre was displaced by 0.66 cm (standard deviation, S.D. = 0.34) from that intended. On each treatment day 29% of anterior films and 45% of lateral films had at least one 0.5 cm error. Overall 59% of treatments had at least one 0.5 cm error and 9% a 1.0 cm error. The field centre was more than 0.5 cm from the position intended in 66% of treatments and over 1 cm for 14% of treatments. Analysis of variance showed that both random and systematic errors occurred in all directions. Though random errors were of similar magnitude in all direction (variance sigma 2 = 0.06-0.09 cm2); systematic errors showed a 4-fold variation being greatest in the LAP direction (sigma 2 = 0.19 cm2) and least the ARL direction (sigma 2 = 0.048 cm2). No factor consistently predicted for worse outcome in all directions. Hypofractionated treatments were less accurate in the LSI direction (P > 0.05). Systematic errors were associated in the ARL direction with hypofractionation (P < 0.01) and, in the LSI direction with weight (P < 0.03) and age (P < 0.05). We conclude that significant random and systematic errors can occur during pelvic radiotherapy especially in the LAP direction. These results suggest that in the absence of a customised immobilisation device, to cover 95% of errors, margins of 0.6 cm for RL and SI directions and 0.9 cm for AP direction should be allowed between the planning and clinical target volumes. However, ideally, each centre should determine their own margin requirements according to local clinical practice.