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R Evans

Publications and source records attributed to R Evans.

At least 217 records · Page 12Linked to original sources
PubMed1995

The role of a nested polymerase chain reaction in the diagnosis of Pneumocystis carinii pneumonia.

Aim-To compare the techniques and results of a nested PCR and an immunofluorescence assay (IFA) for the detection of Pneumocystis carinii infection; to consider the role of the nested PCR in the diagnosis of P carinii pneumonia (PCP).Methods-Serial dilutions of two known P carinii positive samples were tested by IFA and PCR to determine their relative sensitivities. Seventy eight respiratory samples (15 from 11 patients with HIV infection/acquired immunodeficiency syndrome (AIDS) and 63 from 42 patients with other forms of immunodeficiency) were tested using both assays, and the costs and technical requirements of each assay were assessed.Results-The PCR had a greater relative sensitivity over the IFA of 2 x 10(1) to 2 x 10(3) fold in a postmortem lung sample and 2 x 10(5) to 2 x 10(6) fold in a bronchoalveolar lavage sample from a patient with PCP. P carinii was detected in all 15 samples from the patients with HIV/AIDS by both IFA and PCR. Of the 63 samples from the patients with immunodeficiencies other than HIV/AIDS, the PCR was more sensitive than IFA.Conclusions-The nested PCR is a more sensitive assay than the IFA. It may be useful in the diagnosis of PCP in patients with immunodeficiencies other than HIV/AIDS. Similarly, PCR may be of benefit for this patient group as less invasive specimens are needed. PCR has an increasing role to play in the diagnosis of PCP in the routine laboratory.

Journal Article↗
PubMed1994

Qualitative and quantitative intratumoral changes in gene expression following cyclophosphamide injection and the adoptive transfer of T cells: the potential contribution of tumor-associated macrophages.

Adoptive immunotherapy (AIT) of mice bearing the MCA/76-9 rhabdomyosarcoma in combination with cyclophosphamide (CY) injection results in the permanent regression of tumors. This report is concerned with changes in the tumor-associated macrophage (TAM) population and the influence of both CY injection and CY/AIT on their potential functions. Sequential analyses of FcR, MAC-I and Class-II MHC antigen expressed by tumor-associated cells (TAC) showed that CY injection or CY/AIT induced marked increases in the proportions of all 3 parameters as compared with the relatively stable levels in progressing tumors. These changes were time- and treatment-related. The mean MAC-I fluorescence (antigen density per cell) increased nearly 2-fold by 48 hr after CY injection, regardless of subsequent AIT. In contrast, the density of Class-II antigen per cell declined by as much as 75% within 48 hr after CY injection and did not recover by 7 days. This initial decline was also seen after CY/AIT and was followed by a rapid recovery to near-normal values by day 7. Northern analysis of RNA isolated from whole tumor tissue indicated wide fluctuations in expression of the typical macrophage genes encoding the proteins MAC-I, IL-I alpha, IL-I beta, TNF alpha, IA beta and c-fms. However, with the exception of MAC-I and IL-1 alpha/IL-1 beta mRNA, the modifications appeared to be qualitative rather than representing changes in the proportions of TAM. The data suggest that the changes in membrane antigen and gene expression by TAM reflect a complex interaction between TAM and their environment, in particular tumor cells and tumor-infiltrating lymphocytes. In addition, it is evident that CY injection per se is responsible for defined fundamental changes that presumably influence the outcome of AIT.

Animals↗
PubMed1994

Three-field breast irradiation technique using tangential quarter fields.

We have developed and implemented in clinical practice an isocentric three-field breast irradiation technique using tangential quarter fields. In this technique, the same isocenter is used for the supraclavicular and the tangential breast fields. The superior-posterior corner of the tangential breast fields is placed at the central axis by asymmetric collimation of both the length and the width of the field. Consequently, the beam divergence at both the superior and posterior edges is eliminated, allowing a perfect geometric match between the posterior borders of both tangential breast fields and the supraclavicular field without table rotation. Compared to conventional techniques requiring table rotations, the present method produces a more uniform dose distribution in the target volume and requires significantly less simulation time.

Breast↗
PubMed1994

Germline mutations in the neurofibromatosis type 2 tumour suppressor gene.

The recent identification of the NF2 tumour suppressor gene has enabled large scale screening for pathological mutations in the gene. We have sought germline mutations in the NF2 gene by SSCP and heteroduplex analysis of cDNA and genomic DNA samples followed by cloning and sequencing of mutant alleles. In the present report we describe 11 putative pathological mutations, including five nonsense mutations, three short insertions or deletions causing frameshifts and three missense mutations. Most stop mutations and frameshift mutations were found in individuals expressing a severe phenotype while one of the three missense mutations was associated with a mild phenotype. Four unrelated NF2 patients of the 93 tested were found to have identical nonsense mutations caused by a C to T transition (C169) in a CpG dinucleotide, which is a potential mutational hotspot in the NF2 tumour suppressor gene.

Base Sequence↗
PubMed1994

A controlled trial of methylprednisolone in the early emergency department treatment of acute asthma in children.

Asthma continues to be a leading cause for pediatric hospitalizations. A study using high-dose intravenous (i.v.) steroids early in the emergency department (ED) care of adults with acute asthma reported a 60% reduction in hospitalization rate. Limited data are available for children. We hypothesized that the addition of early administration of high-dose methylprednisolone (MP) in routine ED care of asthmatic children would reduce the need for hospitalization by 50%. Eighty-eight children with asthma, aged four to 18 years, were enrolled into a prospective, randomized, double-blind, placebo-controlled study of MP given within 45 (mean 23) minutes of arrival to the ED. After initial evaluation, children received either 2 mg/kg of MP IV or an equivalent amount of placebo (P). Patients then received the usual ED management of their acute exacerbation. Groups were similar in age, sex, and severity of illness (by asthma scoring, respiratory rate, and peak flow). ED treatment (number of aerosols and the use of theophylline) was similar for both groups. The mean time to disposition was 2.9 hours. Sixty-four percent of the children were discharged from the ED. No significant differences were found between the admission rates of the MP and P groups (41% MP vs 33% P, P = 0.44, chi 2, 95% CI for decrease in MP vs P groups -28 to +12%). The average hospital stay was shorter for those children treated with MP (79 hours vs 90 hours). We conclude that IV methylprednisolone given as an adjunct to routine ED care of children with acute asthma is unlikely to markedly reduce hospitalization rates.

Acute Disease↗
PubMed1994

Patterns of injuries to children on public playgrounds.

The incidence and pattern of injuries to children in public playgrounds presenting to the accident and emergency department were reviewed over two six month summer periods in Cardiff. A total of 178 children (mean age 7.5 years) attended with a playground injury representing 1.1% of all the children attending. One hundred and five children fell from equipment, of which the commonest was the climbing frame; 125 children had playground surface related injuries, 86 on bark and 30 on concrete. The pattern of injuries on the playground surfaces was different: fractures and sprains were more common on bark surfaces and lacerations and abrasions on concrete surfaces. Comparison of total injury rates showed there were fewer injuries on modernised playgrounds than expected but these differences were not significant. Modernised playgrounds are more popular, have new exciting equipment, and offer good play opportunities for children. However, the high fracture rate on modernised bark playgrounds is concerning and requires further research.

Accidents↗
PubMed1994

Estimation of body composition in Chinese and British men by ultrasonographic assessment of segmental adipose tissue volume.

It has been shown that ultrasonographic measurements can be used to predict body composition in adults. The purpose of this study was to assess the relationship between ultrasonograph and caliper (SKF) measurements of subcutaneous adipose tissue thickness in athletic Caucasian (English, E) and Asian (Chinese, C) men against estimates of body composition determined from hydrodensitometry (HYD). The usefulness of a proposed ultrasonographic method of estimating lean and fat proportions in the upper and lower limbs was also evaluated as a potential method of predicting body composition. Ultrasonography (US) was used to measure adipose and skin thickness at the following sites: biceps, triceps, subscapular, suprailiac, abdominal, pectoral, thigh and calf. Caliper measurements were also made at the above sites. Subcutaneous fat thickness and segmental radius were measured directly from the display screen of the ultrasonic scanner (Aloka 500 SD). By applying the geometry of a cone, the proximal and distal radii of the upper arm and upper leg were used to calculate the proportionate volumes of adipose tissue. The best correlations for US and SKF were obtained at the quadriceps, subscapular and pectoral sites for E (r = 0.96, 0.93 and 0.90, respectively) and at the quadriceps, calf and abdominal sites for C (r = 0.90, 0.81 and 0.75, respectively). The best ultrasonographic predictor of the percentage fat in both groups was the percentage adipose tissue volume in the upper leg (r = 0.83 and 0.79 for C and E, respectively). Stepwise multiple regression analysis indicated that the prediction of percentage fat was improved by the addition of the ultrasonographic abdomen measurement in both groups: Chinese sample: %fat = %fat(leg) (0.491) + US abdomen (0.337) + 0.95 ( R = 0.89, s.e.e. = 1.9%); English sample: %fat = %fat(leg) (0.435) + US abdomen (0.230) - 0.765 ( R = 0.80, s.e.e. = 3.6%). It is concluded that ultrasonographic measurements of subcutaneous adipose tissue and volumetric assessment of percentage adipose tissue in the thigh are useful estimates of body composition in athletic English and Chinese males.

Adipose Tissue↗
PubMed1994

Intestinal perfusion of dietary levels of aluminium: association with the mucosa.

An aluminium (93 microM) sulphate solution freshly adjusted to pH 7.0 was perfused through the rat small bowel to mimic the reported physiological conditions that follow dietary aluminium ingestion. One third of this aluminium was taken up from the perfusate, but > 90% of this was then recovered from the intestinal mucus/mucosa and most (> 70%) from the distal third of the small bowel. The fresh perfusate was shown by ultrafiltration to contain largely particulate/colloidal aluminium-hydroxide, and this probably adhered to intestinal mucus which may be an important barrier to the gastrointestinal absorption of aluminium.

Alum Compounds↗
PubMed1994

Middle cerebral to umbilical artery Doppler ratio in post-date pregnancies.

OBJECTIVE: To determine which antepartum test is the best predictor of post-date-related adverse outcome among the amniotic fluid index (AFI), nonstress test (NST), biophysical profile, or middle cerebral artery to umbilical artery Doppler ratio. METHODS: Pregnant women of 41 or more weeks' gestation with singleton fetuses and vertex presentations underwent antepartum testing twice a week. Pulsed Doppler ultrasound was used to obtain the flow velocity waveforms from the umbilical and middle cerebral arteries. Adverse post-date-related outcome was defined as the occurrence of meconium aspiration syndrome, cesarean delivery for fetal distress, or fetal acidosis. The predictive values of an AFI equal to or less than 5 cm, a biophysical profile score equal to or greater than 6, a nonreactive NST, and a middle cerebral artery to umbilical artery ratio less than 1.05 in identifying adverse outcome were compared. RESULTS: Forty-nine women met the inclusion criteria; ten (20.4%) had an adverse outcome. A middle cerebral artery to umbilical artery ratio of less than 1.05 was found to be the best predictor of adverse outcome, with a sensitivity of 80%, specificity of 95%, positive predictive value of 80%, and negative predictive value of 95%. The other three diagnostic tests had sensitivities equal to or less than 40%. The middle cerebral artery to umbilical artery ratio was also a better discriminator of adverse outcome than either the umbilical artery systolic-diastolic (S/D) ratio or the middle cerebral artery S/D ratio. CONCLUSION: Although the sample size of our study was small, the results suggest that a middle cerebral artery to umbilical artery ratio of less than 1.05 is an accurate method of predicting post-date-related adverse outcome.

Adolescent↗
PubMed1993

Intratumor gene expression after adoptive immunotherapy in a murine tumor model. Regulation of messenger RNA levels associated with the differential expansion of tumor-infiltrating lymphocytes.

The aim of this paper was to show that the adoptive immunotherapy (AIT) of established tumors resulted in the activation of defined lymphocyte-associated genes at the site of rejection. C57BL/6J mice bearing the moderately immunogenic syngeneic MCA/76-9 sarcoma received combination therapy 10 days after tumor cell implantation. This consisted of a single i.p. injection of cyclophosphamide (CY) followed by the i.v. injection of tumor-sensitized T cells (CY/AIT). The previously observed in situ differential expansion of tumor-infiltrating lymphocytes (TIL) was associated with a parallel modulation of CD4 (L3T4) and CD8 Ag expression. Flow cytometric analysis indicated that the CD8+ TIL appeared to contain two subpopulations during the reported proliferative phase, but by day 8 after CY/AIT the cells were composed of a single bright population. The CD4+ TIL similarly appeared to show two subpopulations, but in contrast to the CD8+ TIL there was a shift to a predominantly less bright single population by day 8. The expression of lymphocyte genes (Ly-2 and Ly-4 encoding the CD8 and CD4 Ag, respectively, IL-2, IL-2R, IFN-gamma, and IL-6) was analyzed by Northern hybridization using RNA extracted from whole tumor tissue. Progressing tumors expressed only low and relatively constant levels of mRNA for all of the genes except Ly-2 over a 19-day period. In contrast, there were considerable temporal fluctuations in mRNA levels depending on whether the mice had received CY or CY/AIT, but it was apparent that CY/AIT induced the more dramatic changes as far as Ly-2, Ly-4, IL-2, and IFN-gamma mRNA levels were concerned. A preliminary survey of cytokine bioactivity released by tumor-associated cells isolated 9 days after CY/AIT indicated that both IFN-gamma and IL-6 activities were released by the cells, but not IL-2, despite the relatively high levels of IL-2 mRNA. These data provide evidence that the differential expansion of TIL after CY/AIT is accompanied by well defined changes in the levels of mRNA-encoding TIL membrane Ag and lymphokine genes and are concordant with the view that amplified anti-tumor immune responses occur after AIT.

Animals↗
PubMed1993

Midazolam sedation for the reduction of Colles' fractures.

The treatment of Colles' fractures in the elderly comprises a heavy workload for both accident and orthopaedic departments. The initial management has important clinical and financial implications for patient and hospital. The demand is variable and the ability to respond must also be flexible. The choice of anaesthetic technique is therefore most important. In our experience, intravenous sedation with midazolam (a water soluble benzodiazepine) has proven to be safe and effective in providing good conditions for anatomical reduction of Colles' fractures on an outpatient basis.

Aged↗
PubMed1993

Palpation compared with ultrasound in the assessment of malignant cervical lymph nodes.

This prospective study compares the results of pre-operative clinical examination and simple ultrasound examination of the neck in 18 patients with proven head and neck primary tumours and palpable cervical lymphadenopathy, who then underwent 21 radical neck dissections. Neck palpation and ultrasound examination were compared with histological examination. Ultrasound did not add significantly to the information obtainable by simple neck palpation in this group of patients.

Carcinoma, Squamous Cell↗
PubMed1993

Logistic regression analysis of fixed patient factors for postoperative sickness: a model for risk assessment.

One hundred and forty-seven patients undergoing minor orthopaedic surgery were studied prospectively by logistic regression analysis to determine the association of independent fixed patient factors with the incidence of postoperative sickness (nausea, retching or vomiting). Gender, history of previous postoperative sickness, postoperative opioids and interaction between gender and previous history of sickness were significant independent factors for postoperative sickness; history of motion sickness was weakly associated. The probability of postoperative sickness in the first 24 h after surgery may be estimated from the equation: logit postoperative sickness = -5.03+2.24(postoperative opioids) +3.97 (previous sickness history) +2.4 (gender) +0.78 (motion sickness) -3.2 (gender x previous sickness history). (Log likelihood ratio test for 5 degrees of freedom for the coefficients, chi-square = 53.5 (P < 0.001).) It is suggested that the calculated probability for sickness may be a useful addition for balancing patient treatment groups and allowing between-study comparisons.

Adolescent↗