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Biomedical subjects

J Booth

Publications and source records attributed to J Booth.

At least 37 records · Page 2Linked to original sources
PubMed1999

Epitope mapping of mouse monoclonal antibodies to the ppUL83 lower matrix phosphoprotein of human cytomegalovirus.

Of nine mouse monoclonal antibodies (MAbs) directed against the lower matrix protein (pp65; ppUL83) of human cytomegalovirus (HCMV), all immunoprecipitated the 65-kDa protein. Only five were reactive by Western blotting, however, and four of these mapped to linear antigenic epitopes located between amino acids 184-195 (MAb C6), 343-357 (MAb C11), 448-462 (MAb C5), and 448-459 (MAb C13). The epitope specificity of the fifth antibody (MAb C3) and the four that recognised nonlinear sites could not be determined. Competition binding studies using HCMV antigen extracted from productively infected human embryonic lung fibroblasts (HELF), in an enzyme immunoassay (EIA), showed that three of the antibodies reactive with linear epitopes and two of those reactive with conformational epitopes (MAbs C3, C6, C11, C14, and C18), were unique in their binding specificities. MAb C4 competed with MAb C8 and MAb C5 competed with MAb C13 for binding to ppUL83. One of the linear epitopes identified, corresponding to amino acids SAFVFPTKDVAL (MAb C6), was an epitope described previously for CD8+ cytotoxic T lymphocytes.

Amino Acid Sequence↗
PubMed1998

Genetic studies on chromosome 12 in late-onset Alzheimer disease.

CONTEXT: The only genetic locus universally accepted to be important as a risk factor for late-onset Alzheimer disease (AD) is the apolipoprotein E (APOE) locus on chromosome 19. However, this locus does not account for all the risk in late-onset disease, and a recent report has suggested a second locus on chromosome 12p11-12. OBJECTIVE: To look for evidence of linkage on chromosome 12 and to test for the presence of the new locus in an independent sample of familial late-onset AD cases. DESIGN: Retrospective cohort study. As part of a 20-centimorgan genome screen (approximately equal to 200 markers), we tested a series of 18 genetic markers on chromosome 12 and carried out multipoint, nonparametric lod score and exclusion analyses. SETTING: Clinic populations in the continental United States selected from the National Institute of Mental Health AD Genetics Consortium. PATIENTS: We selected samples for DNA analysis from affected sibling pairs, 497 subjects from 230 families with 2 or more affected individuals with probable or definite AD with onset ages older than 60 years (mean+/-SD, 75+/-6 years). Within the families, we used the 2 probable or definitely affected individuals. In families with more than 2 such cases available, we used all of them; in families with only 2 such cases in which unaffected individuals were available, we also sampled the oldest unaffected individual and used genotype data from this unaffected individual to check for nonpaternity and genotyping errors. MAIN OUTCOME MEASURE: Presence of linkage or locus on chromosome 12. RESULTS: Although linkage analyses confirmed the presence of a genetic susceptibility factor at the APOE locus in these families with late-onset AD, we were unable to confirm the presence of a locus close to the marker D12S1042. A moderate lod score (1.91) was found near D12S98 close to the alpha2-macroglobulin locus in the affected pairs in which both members did not possess an APOE epsilon4 allele. CONCLUSIONS: APOE remains the only locus established to be a risk factor for late-onset AD. We were unable to confirm that a locus on chromosome 12p11-12 has a major effect on risk for late-onset AD, although an effect smaller than that for APOE cannot be excluded.

Age of Onset↗
PubMed1998

Influence of insurance type on the use of procedures, medications and hospital outcome in patients with unstable angina: results from the GUARANTEE Registry. Global Unstable Angina Registry and Treatment Evaluation.

OBJECTIVES: The purpose of this study was to investigate whether or not there is an association between managed care insurance and the delivery and outcome of care in patients presenting with unstable angina. BACKGROUND: The proportion of U.S. patients with managed care health insurance is increasing. This may be associated with recent improvements in the control of health care costs. It is unknown whether or not there is a difference in process of care in angina patients presenting with managed care versus fee-for-service health insurance. METHODS: We compared baseline characteristics, process and outcome of care in 636 patients with managed care insurance (MC) and 1,404 patients with fee-for-service (FFS) insurance who presented with unstable angina to 35 hospitals participating in the global Unstable Angina Registry and Treatment Evaluation (GUARANTEE) Registry. RESULTS: Although, there was little difference in baseline characteristics and hospital treatments between cohorts, MC patients were more likely to be discharged on guideline-recommended medications (aspirin and beta-adrenergic blocking agents). In addition, FFS patients were more likely to undergo cardiac catheterization (odds ratio = 1.25 95% confidence interval = 1.1 to 1.5), but not revascularization during the hospitalization. There was no difference in hospital mortality (0.9% versus 1.2% in MC versus FFS; p = 0.60). CONCLUSIONS: In patients admitted with suspected unstable angina, MC patients are less likely to undergo coronary angiography, but are more likely to be discharged on indicated medications.

Adrenergic beta-Antagonists↗
PubMed1998

Is routine post-operative surveillance for cytomegalovirus infection following heart transplantation necessary?

OBJECTIVE: Cytomegalovirus infection (CMV) is an important cause of morbidity and mortality following cardiac transplantation. The purpose of the present study was to ascertain whether routine post-operative screening for CMV infection influenced clinical management. METHODS: Laboratory and case notes of 220 patients who received cardiac transplantation between November 1986 and October 1996 were reviewed. The range of follow-up was one to 120 (median 36) months. CMV surveillance involved blood tests for early antigen detection weekly for the first 6 post-operative weeks, fortnightly thereafter until the end of the third post-operative month and every 6 weeks to the end of the first post-operative year. Otherwise monitoring was performed if the patients had clinical symptoms suggestive of CMV infection. CMV sero-negative IgG recipients (R) of sero-positive IgG donor (D) organs and/or blood products received hyper-immune gammaglobulin for the first three post-operative months. Four patient groups were noted, namely R+D+ (59 patients), R+D- (70 patients), R-D+ (35 patients) and R-D- (56 patients). RESULTS: CMV antigenaemia was present in 40% (89) of patients and 48% (43) of these patients developed clinical features of CMV infection and received ganciclovir therapy. The distribution of clinical CMV infection requiring treatment was 25% (9/35) in the R+D- group, 50% (16/32) in the R+D+ group and 85% (18/22) in the R-D+ group. None of the patients in the R-D- group developed CMV antigenaemia. Forty six (52%) patients who were CMV antigen positive but who did not develop symptoms were not treated with ganciclovir and have remained well. CONCLUSION: Our results suggest that routine screening for CMV following cardiac transplantation is unnecessary. Surveillance did not result in the instigation of treatment for CMV unless there were associated clinical features of CMV infection.

Antigens, Viral↗
PubMed1998

Whole body cooling by immersion in water at moderate temperatures.

This study investigated the potential use of whole body cooling by water immersion for lowering body temperatures prior to endurance exercise. Rectal temperature (Tre), mean skin temperature (Tsk), oxygen consumption (VO2), and ventilation (VE) were measured in 7 male and 3 female subjects who were immersed in a water bath for up to 60 min. Initial water temperature was 28.8+/-1.5 degrees C and decreased to 23.8+/-1.1 degrees C by the end of immersion. Pre-immersion Tre of 37.34+/-0.36 degrees C was not altered by 60 min water immersion but decreased to 36.64+/-0.34 degrees C at 3 min post immersion (p < 0.01). Tsk decreased from 33.23+/-1.4 degrees C to 26.95+/-1.8 degrees C (p < 0.01) at the end of immersion. Reductions in Tre and Tsk resulted in reduced body heat content (Hc) of approximately 545 kJ (p < 0.01) at the end of immersion. VO2 and VE increased from pre-immersion values of 0.34+/-0.08 L x min(-1) and 6.2+/-1.4 L x min(-1) to 0.54+/-0.09 L x min(-) and 11.5+/-5.4 L x min(-1) at the end of immersion, respectively. Heart rate remained unchanged throughout immersion. These results indicate that whole body immersion in moderately cold water temperatures is an effective cooling maneuver for lowering body temperatures and body Hc in the absence of severe physiological responses generally associated with sudden cold stress.

Analysis of Variance↗
PubMed1997

Gypsum Overgrowths Passivate Calcite to Acid Attack

The dissolution of calcite (CaCO3) in aqueous solution at pH below ca. 5-6 is known to proceed via the direct reaction of protons at the solid surface. However, exposure of the mineral to sulfuric acid is shown to lead to the rapid formation of an overlayer of calcium sulfate (gypsum) which completely passivates the surface against further reaction and dissolution. The overlayer is nucleated instantaneously on CaCO3 surfaces. Scanning electron and atomic force microscopy show that strongly adherent overgrowths are encouraged by a lattice matching between the cleavage (211) plane of calcite and the (010) plane of CaSO4&middot;2H2O.

Journal Article↗
PubMed1997

Kinetics and Mechanism of Dyeing Processes: The Dyeing of Cotton Fabrics with a Procion Blue Dichlorotriazinyl Reactive Dye

The kinetics of the dyeing of a dichlorotriazinyl-reactive dye, Procion Blue MX-R, with knitted cotton fabrics have been studied using a versatile technique based on a spectrochemical channel flow cell. A mechanism is derived where the simultaneous hydrolysis of the dye molecules, the physical binding of the hydrolyzed form, and the chemical fixation of the active form onto the fabric are taken into account. It is shown that the dye fixation to the fabric is controlled by a solid-liquid interfacial process that is first order with respect to the surface concentration of dye; however, the rate of this reaction is governed by the availability of sites for the adsorption of dye molecules on the fabric surface. Dyeing experiments are performed over a wide range of initial dye concentrations; supporting electrolyte concentrations and the kinetic parameters are reported. Atomic force microscopic studies indicate that mercerization pretreatment provides a disordered fiber surface which may offer additional sites for dye adsorption.

Journal Article↗
PubMed1997

A novel approach for the quantitative kinetic study of reactions at solid/liquid interfaces in the presence of power ultrasound.

A novel cell and procedure is described which permits the quantitative mechanistic study of ultrasonically enhanced reactions which occur at solid/liquid interfaces. A model of a controlled and calculable time-average rate of mass transport to and from the interface is used in order to compare experimental results with theoretical predictions based on mechanistic reaction schemes. In this way concentrations of mechanistically significant species near the interface can be related to those in bulk solution and hence the sonochemical effects of ultrasound dissected from those arising purely from mass transport. The effect of ultrasound is demonstrated for the reaction dissolution of p-chloranil in the presence of aqueous base and for the reaction of the same substrate with the aromatic amine, N,N-dimethyl-phenylenediamine, both systems which have been studied previously in the absence of ultrasound. Complementary atomic force microscopy images are also reported.

Journal Article↗
PubMed1997

Decreased survival in patients with co-existent rheumatoid arthritis and bronchiectasis.

The aim was to compare the 5 yr survival in patients with rheumatoid arthritis (RA) alone, bronchiectasis (Br) alone and RA plus Br (RA-Br). A case-control study was carried out in which 32 patients with RA-Br were matched for age (within 5 yr), sex and (where possible) disease duration with 32 patients with RA alone. An additional comparison group of 31 unselected patients with Br was chosen. All patients were followed for 5 yr. Patients with RA-Br were 7.3 times more likely to die than the general population, 5.0 times more likely than the RA group and 2.4 times more likely than the Br group. An increased risk of death within the RA-Br group was associated with a history of smoking, more severe RA and steroid usage. The co-existence of RA and Br is associated with a poor 5 yr survival.

Adult↗
PubMed1997

Improved running performance in hot humid conditions following whole body precooling.

On two separate occasions, eight subjects controlled speed to run the greatest distance possible in 30 min in a hot, humid environment (ambient temperature 32 degrees C, relative humidity 60%). For the experimental test (precooling), exercise was preceeded by cold-water immersion. Precooling increased the distance run by 304 +/- 166 m (P < 0.05). Precooling decreased the pre-exercise rectal and mean skin temperature by 0.7 degrees C and 5.9 degrees C, respectively (P < 0.05). Rectal and mean skin temperature were decreased up to 20 and 25 min during exercise, respectively (P < 0.05). Mean body temperature decreased from 36.5 +/- 0.1 degrees C to 33.8 +/- 0.2 degrees C following precooling (P < 0.05) and remained lower throughout exercise (P < 0.01) and at the end of exercise (by 0.8 degrees C; P < 0.05). The rate of heat storage at the end of exercise increased from 113 +/- 45 to 249 +/- 55 W.m-2 (P < 0.005). Precooling lowered the heart rate at rest (13%), 5 (9%), and 10 min (10%) exercise (P < 0.05) and increased the end of exercise blood lactate from 4.9 +/- 0.5 to 7.4 +/- 0.9 mmol.L-1 (P < 0.01). The VO2 at 10 and 20 min of exercise and total body sweating are not different between tests. In conclusion, water immersion precooling increased exercise endurance in hot, humid conditions with an enhanced rate of heat storage and decreased thermoregulatory strain.

Adult↗
PubMed1997

Saturday night blue--a case of near fatal poisoning from the abuse of amyl nitrite.

A case of severe methaemoglobinaemia caused by the abuse of volatile nitrites is reported. The agents are commonly abused, but this complication is rare. The clinical presentation can make diagnosis difficult; however, the subsequent treatment needs to be rapid to avoid serious morbidity or mortality. This report presents the clinical picture and the background information leading to the detection and treatment of this unusual problem.

Adult↗
PubMed1997

Impaired calcium pump function does not slow relaxation in human skeletal muscle after prolonged exercise.

This study examined the effects of prolonged exercise on human quadriceps muscle contractile function and homogenate sarcoplasmic reticulum Ca2+ uptake and Ca2+-adenosinetriphosphatase activity. Ten untrained men cycled at 75 +/- 2% (SE) peak oxygen consumption until exhaustion. Biopsies were taken from the right vastus lateralis muscle at rest, exhaustion, and 20 and 60 min postexercise. Peak tension and half relaxation time of the left quadriceps muscle were measured during electrically evoked twitch and tetanic contractions and a maximal voluntary isometric contraction at rest, exhaustion, and 10, 20, and 60 min postexercise. At exhaustion, homogenate Ca2+ uptake and Ca2+ adenosinetriphosphatase activity were reduced by 17 +/- 4 and 21 +/- 5%, respectively, and remained depressed after 60 min recovery (P </= 0.01). Muscle ATP, creatine phosphate, and glycogen were all depressed at exhaustion (P </= 0.01). Peak tension during a maximal voluntary contraction, a twitch, and a 10-Hz stimulation were reduced after exercise by 28 +/- 3, 45 +/- 6, 65 +/- 5%, respectively (P </= 0.01), but no slowing of half relaxation times were found. Thus fatigue induced by prolonged exercise reduced muscle Ca2+ uptake, but this did not cause a slower relaxation of evoked contractions.

Adult↗
PubMed1996

Molecular epidemiology and significance of a cluster of cases of CMV infection occurring on a special care baby unit.

Sequencing of the amino-terminal region of the glycoprotein H gene was used to investigate the possibility of a common source for cytomegalovirus (CMV) infection occurring in five premature babies. All but two of the strains were different, indicating that this cluster of infection occurring on the special care baby unit was unlikely to be epidemiologically linked.

Cross Infection↗
PubMed1996

Effect of water ingestion on endurance capacity during prolonged running.

This study examined the influence of water ingestion on endurance capacity during submaximal treadmill running. Four men and four women with a mean (+/-S.E.) age of 21.4 +/- 0.7 years, height of 169 +/- 2 cm, body mass of 63.1 +/- 2.9 kg and VO2 max of 51.1 +/- 1.8 ml kg-1 min-1, performed two randomly assigned treadmill runs at 70% VO2 max to exhaustion. No fluid was ingested during one trial (NF-trial), whereas a single water bolus of 3.0 ml kg-1 body mass was ingested immediately pre-exercise and serial feedings of 2.0 ml kg-1 body mass were ingested every 15 min during exercise in a fluid replacement trial (FR-trial). Run time for the NF-trial was 77.7 +/- 7.7 min, compared to 103 +/- 12.4 min for the FR-trial (P < 0.01). Body mass (corrected for water ingestion) decreased by 2.0 +/- 0.2% in the NF-trial and 2.7 +/- 0.2% in the FR-trial (P < 0.01), while plasma volume decreased by 1.1 +/- 1.1% and 3.5 +/- 1.1% in the two trials respectively (N.S.). However, these apparent differences in circulatory volume were not associated with differences in rectal temperature. Respiratory exchange ratios indicated increased carbohydrate metabolism (73% vs 64% of total energy expenditure) and suppressed fat metabolism after 75 min of exercise in the NF-trial compared with the FR-trial (NF-trial, 0.90 +/- 0.01; FR-trial, 0.86 +/- 0.03; P < 0.01). Blood glucose concentrations were similar in both trials, while blood lactate concentrations were higher in the NF-trial at the end of exercise (4.83 +/- 0.34 vs 4.18 +/- 0.38 mM; P < 0.05). In summary, water ingestion during prolonged running improved endurance capacity.

Adult↗
PubMed1996

Enteroviral pharyngitis diagnosed by reverse transcriptase-polymerase chain reaction.

The role of enteroviruses in childhood pharyngitis was investigated using enteroviral specific reverse transcriptase-polymerase chain reaction (RT-PCR). Viral/bacterial throat swabs were taken from 50 children with acute pharyngitis and 26 controls. A positive culture was identified in only 26% of children with pharyngitis (adenovirus 10%, group A streptococci 2%), and none of the controls. Enteroviral RT-PCR was positive in 8% of the pharyngitis group and none of the controls. Enteroviruses are an important cause of pharyngitis in childhood.

Acute Disease↗
PubMed1996

Pathophysiology and treatment of hepatitis C.

Hepatitis C virus (HCV) infection is associated with a variable disease course and response to therapy. Some infected patients may develop little or no disease for 30 to 40 years, whereas others will develop cirrhosis within 5 to 10 years. Both host and viral factors influence the rate of disease progression. The management of patients is determined by the severity of their disease assessed by liver biopsy. Those with mild hepatitis without fibrosis do not require treatment but should undergo liver biopsy every 3 years. Patients with mild hepatitis with fibrosis, or with moderate or severe hepatitis with or without fibrosis, should be offered treatment. Interferon-alpha (IFN alpha) is currently the only licensed treatment for HCV infection. Although initial response rates to IFN alpha are high, over half the patients relapse and a sustained response is achieved in only 10 to 35% of patients. Higher doses of IFN alpha and a longer treatment duration are associated with better response rates. Treatment options for those who fail to respond to IFN alpha include a second course of IFN alpha at a higher dose or IFN alpha in combination with ribavirin, phlebotomy or ursodeoxycholic acid. At present, however, there are insufficient data to routinely recommend any of these options.

Hepatitis C↗