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Biomedical subjects

R J Mills

Publications and source records attributed to R J Mills.

At least 19 recordsLinked to original sources
PubMed2006

3D MRI in multiple sclerosis: a study of three sequences at 3 T.

The objective of this study was to assess the feasibility of using 3D acquisition at 3 T for imaging patients with multiple sclerosis (MS). Feasibility was assessed by three criteria based on acquisition time, specific absorption rate (SAR) and image quality. 47 patients with clinically definite MS underwent imaging in a Siemens 3T Trio MR scanner. Patient safety data were obtained following the scan sessions. The study had local ethics approval. The following three-dimensional (3D) sequences, all acquired coronally, were used: T2 fluid attenuated inversion recovery (FLAIR) (repetition time (TR) 6000 ms, echo time (TE) 353 ms, inversion time (TI) 2200 ms), 0.5x0.5x1 mm voxels, acquisition time 10 min 38 s; T2 turbo spin echo (TSE) (TR 3000 ms, TE 354 ms), 1x1x1 mm voxels, acquisition time 8 min 29 s; T1 inversion recovery (IR) (TR 2040 ms, TE 5.56 ms, TI 1100 ms), matrix 512x448 (0.5x0.5 mm pixels), 0.5x0.5x1 mm voxels, acquisition time 7 min 38 s. Total acquisition time was 26 min 45 s. Example images are presented. 3D scanning at 3 T provides highly detailed, high quality images with acquisition times tolerated by MS patients, even by those with severe disability. The volumetric data are suitable for a wide variety of post-processing techniques; the authors suggest that 3D studies at 3 T should be considered as the possible brain imaging protocol for either cross-sectional or longitudinal studies in MS and that the 3D T2 FLAIR sequence should be considered for the purposes of radiological diagnosis.

Adult↗
PubMed2000

Increased pre-operative platelet counts are a possible predictor for reduced sensitivity to heparin.

We investigated a possible relationship between pre-operative platelet count and reduced sensitivity to heparin in 87 patients undergoing cardiac surgery with cardiopulmonary bypass (CPB). Sensitivity to heparin was determined by measuring the slope of the heparin dose response (HDR) before surgery. Pre-operative platelet counts were measured as part of routine analysis of the patients' coagulation status. Patients with an HDR slope of <80 s u. ml(-1), were considered to have a reduced sensitivity to heparin and activated clotting time data were collected from these patients before and after heparin administration before CPB. A significant correlation was determined between pre-operative platelet levels and HDR slope (P<0.001). Platelet counts were significantly greater in heparin-resistant patients compared with those who had the expected response to the anticoagulant (P<0.05). This could be caused by an increased capacity to produce platelet factor 4, which neutralizes heparin.

Aged↗
PubMed1998

Tensometry of carbon fibres and elastomers at the diffractometer at BL20B of the Photon Factory.

Two systems have been developed for the simultaneous recording of the SAXS and the WAXS patterns from carbon fibre and elastomer samples which are placed under stress. The systems have been designed to fit inside the versatile vacuum diffractometer (BIGDIFF) at the Photon Factory. In one system, use is made of the ability to move the imaging-plate cassette. In the other, use has been made of an imaging-plate changer which can deliver up to 13 plates into position with a duty cycle of about 60 s. In this case each imaging plate can record SAXS/WAXS patterns in the range 0.5-20 degrees due to the passage of the beam through the specimen which is mounted in a specially designed tensometer. Because BIGDIFF is a vacuum diffractometer and parasitic scattering is small, exposure times as short as 2 s can give acceptable SAXS/WAXS patterns. The systems have been used for the study of both the change of structure with strain, and the relaxation processes which occur as a result of the sample being strained at a fixed rate by a predetermined amount.

Journal Article↗
PubMed1998

Neosporosis in a pup.

CASE: A 13-week-old female boxer pup was found to be suffering from rigidity of the left hindleg. Antibiotic and anti-inflammatory treatment over a 3-week period failed to improve the condition and the pup was humanely killed. METHODS: Serological examination for Neospora antibodies was carried out by the indirect fluorescent antibody test and for Toxoplasma gondii antibodies with a latex agglutination test. A variety of tissues were examined histologically, and the central nervous system by immunohistochemistry and the polymerase chain reaction. RESULTS: The IFAT for anti-Neospora antibodies showed a titre of 1:51 200 in the clinically affected pup while the latex agglutination test for Toxoplasma antibodies was negative. The dam and one of two tested litter-mates had anti-Neospora IFAT titres of 1:1600, the other litter mate was negative. All three were not clinically affected. Histological, immunohistochemical and polymerase chain reaction examinations of the affected pup confirmed the diagnosis of Neospora infection. CONCLUSION: In the live animal, serological examination is thought to be the most useful specific test. Post-mortem examination by traditional histology, immunohistochemistry and the polymerase chain reaction confirmed the diagnosis. The case is discussed in the context of present knowledge about Neospora infection in New Zealand.

Journal Article↗
PubMed1998

Impact of zidovudine plus lamivudine or zalcitabine on health-related quality of life.

OBJECTIVE: To assess the impact of treatment with zidovudine plus lamivudine or zalcitabine on health-related quality of life (HRQOL) in patients with HIV. DESIGN: HRQOL assessments were conducted as part of a double-blind, randomized, 24-week (extended to 52 wk) efficacy and safety study. The Medical Outcomes Study HIV Health Survey (MOS-HIV), which assesses 10 physical and psychological domains of HRQOL, was self-administered by patients at baseline and at weeks 16, 32, 52, or at treatment discontinuation. SETTING: Twenty-one outpatient centers in the US, Canada, and Puerto Rico. PATIENTS: The study enrolled 254 HIV-positive patients (CD4+ 100-300 cells/mm3); 206 patients completed the MOS-HIV at baseline and at least once during treatment. Post hoc analyses stratified patients into two subgroups: AIDS (CD4+ < 200 cells/mm3) and non-AIDS (CD4+ > or = 200 cells/mm3). INTERVENTIONS: Patients received zidovudine 200 mg three times daily plus one of the following: lamivudine 150 mg twice daily, lamivudine 300 mg twice daily, or zalcitabine 0.75 mg three times daily. MAIN OUTCOME MEASURE: Change in MOS-HIV scores from baseline to last completed questionnaire. RESULTS: Following an average of 36 weeks of treatment, there were statistically significant differences across treatment groups in mean change scores on the physical functioning, role functioning, and vitality scales, with stable or increased (improved) scores in the zidovudine plus lamivudine 150 mg group and decreased scores in the zidovudine plus zalcitabine and zidovudine plus lamivudine 300 mg groups for most scales. Post hoc analyses found that in the non-AIDS subgroup, only the zidovudine plus lamivudine 150 mg group had increases in mean MOS-HIV scores (on 8 of 10 scales); in the AIDS subgroup, all but two MOS-HIV scores (in the zidovudine plus zalcitabine group) decreased in all three treatment groups. CONCLUSIONS: These results suggest that, of the three combination therapies studied, zidovudine plus lamivudine 150 mg was most likely to maintain or improve HRQOL in HIV-positive patients.

Adult↗
PubMed1998

Harnessing peer networks as an instrument for AIDS prevention: results from a peer-driven intervention.

OBJECTIVE: Since 1985, community outreach efforts to combat acquired immunodeficiency syndrome (AIDS) among injecting drug users (IDUs) in the United States have overwhelmingly depended on a provider-client model that relies on staffs of professional outreach workers. We report on a comparison of this traditional outreach model with an innovative social network model, termed "a peer-driven intervention" (PDI). The latter provides IDUs with guidance and structured incentives that permit them to play a much more active role in the outreach process, thereby harnessing peer pressure on behalf of human immunodeficiency virus (HIV) prevention efforts. METHODS: We compare the performance of a traditional outreach intervention (TOI) and a PDI that were implemented in medium-sized towns in eastern and central Connecticut. Comparisons are based on the number and representativeness of IDUs recruited at each site, the effectiveness of HIV prevention education, compliance rates with AIDS risk reduction recommendations, and relative cost. The analyses are based on 522 initial interviews and 190 six-month follow-up interviews conducted during the first two years of each intervention's operation. RESULTS: Both interventions produced significant reductions in HIV risk behaviors, as measured using self-reports. The PDI outperformed the traditional intervention with respect to the number of IDUs recruited, the ethnic and geographic representativeness of the recruits, and the effectiveness of HIV prevention education. In addition, the costs of recruiting IDUs into the intervention and educating them about HIV in the community was only one-thirtieth as much in the PDI as in the traditional intervention. CONCLUSIONS: The findings suggest that given guidance and nominal incentives, IDUs can play a more extensive role in community outreach efforts than the traditional model allows. The findings also suggest that both interventions reduce HIV-associated risk behaviors, but the PDI reaches a larger and more diverse set of IDUs, and does so at much less expense.

Adult↗
PubMed1991

Ranitidine prevents duodenal ulcers associated with non-steroidal anti-inflammatory drug therapy.

The results of four similarly designed, randomized, double-blind, placebo-controlled studies conducted to evaluate ranitidine as prophylaxis for NSAID-associated damage are reviewed. A total of 673 patients receiving therapeutic dosages of NSAIDs for arthritic or musculoskeletal conditions also received either ranitidine 150 mg twice daily (n = 343) or placebo (n = 330) for four weeks (two studies) or eight weeks (two studies). Endoscopic grading of mucosal lesions was based on a modified Lanza scoring system. All patients had normal baseline endoscopies. After four weeks of treatment a significant protective effect against duodenal mucosal lesions including duodenal ulcers (three studies) and gastric mucosal lesions including gastric ulcers (one study) was observed in patients who received ranitidine compared with those who received placebo. A meta-analysis of the four studies confirmed that significantly fewer patients receiving ranitidine than placebo developed duodenal ulcers (1% vs. 6%, P = 0.01). Endoscopic data at eight weeks from the two longer-term studies showed that duodenal ulcers occurred in ranitidine- and placebo-treated patients at a rate of 1% (2/137) vs. 8% (10/126) (P = 0.02), respectively, in one trial, and 0% (0/57) vs. 8% (4/49) (P = 0.02), respectively, in the other trial. No protective effect in the stomach was evident at eight weeks. We conclude that ranitidine is effective in preventing NSAID-associated duodenal ulcers and may be appropriate prophylaxis for certain high-risk patients.

Adult↗
PubMed1988

Effects of antihypertensive agents on circadian blood pressure and heart rate patterns. Review.

Blood pressure and heart rate exhibit a circadian rhythm, with both rising rapidly during the morning hours and then decreasing throughout the day to a nadir around 3 AM. Current evidence suggests a possible link between cardiovascular events, such as myocardial infarction and sudden cardiac death, which have been shown to occur most frequently during the morning hours, and the rapid rise in blood pressure and heart rate during this same time period. We review data from ambulatory blood pressure studies to ascertain which antihypertensive agents provide the most satisfactory control of blood pressure and heart rate during the hours of 6 AM to 12 noon. Of the forms of drug therapy studied, labetalol, a combined alpha- and beta-blocker, and two calcium channel blockers, nifedipine and verapamil, appear to be the most effective in blunting the rise in arterial blood pressure during these critical morning hours.

Antihypertensive Agents↗
PubMed1987

Peak expiratory flow in normal Ethiopian children and adults in Addis Ababa.

The peak expiratory flow rate was determined using the Wright peak flow meter in normal Ethiopian children and adults residing in Addis Ababa (altitude 2500 m). The sample studied was of 84 boys, 69 girls (4-17 years) and 177 men, 148 women (18-70 years). Normality was determined by history alone. Linear multiple regression analysis was used to construct prediction equations that depended upon height and age. The results serve as reference values specifically for Ethiopians residing at altitude. Comparison of the PEFR values determined in 47 Caucasians (22 males, 27 females) working in Addis Ababa, with those from a group of Ethiopians matched for age and height indicated that the mean PEFR was significantly greater in the Caucasians by 7.3% in males and by 8.2% in females.

Adolescent↗
PubMed1986

A critical appraisal of a rapid radiographic method of determining total lung capacity.

We have demonstrated that the total lung capacities of normal caucasian adults, can be satisfactorily estimated by means of a regression equation derived from a single set of three measurements taken from a specially exposed plain X-ray film of the chest. However, these equations differ from those found by workers who have studied patients with lung disease. It is concluded from this that different regression equations are to be expected for normal and diseased lungs, and that, the appropriate equation will depend not only on the presence of disease, but also on its type and severity. It is also concluded that the rapid radiographic method of estimating total lung capacity can make little contribution to the diagnostic assessment of lung disease. However, the regression equations appropriate to particular ethnic groups could be used to measure TLC in normal subjects rapidly and inexpensively in places where specialised respiratory equipment and trained personnel are lacking.

Adult↗
PubMed1984

Sex hormone suppression and sexual impotence in hypoxic pulmonary fibrosis.

Eight men with hypoxia associated with idiopathic pulmonary fibrosis were studied. Serum testosterone concentrations were low in two subjects and fell to subnormal levels in two others as the clinical condition and arterial oxygen tension deteriorated. There was a significant correlation between serum testosterone concentrations and arterial oxygen tensions (p less than 0.05). Three patients showed evidence of suppression of luteinising hormone secretion at the pituitary level. Only occasional abnormalities of thyroid and prolactin concentrations were noted. Most of the men suffered from organic sexual impotence, which is considered to be due at least in part to endocrine disturbance. These findings are similar to observations in patients with hypoxic chronic obstructive airways disease and support the hypothesis that hypoxia of lung disease suppresses the hypothalamo-pituitary-testicular axis.

Adult↗
PubMed1984

Pulmonary hypersensitivity in the alginate industry.

Salts of alginic acid are complex polymerised polysaccharides which are chemically extracted from seaweed. Workers in the alginate industry are exposed to dust from dried milled seaweed and pure alginate compounds. In this survey of one of the two factories in Britain producing alginates, we found evidence of pulmonary hypersensitivity to seaweed dust in seven per cent of the total work force, and evidence of precipitating antibody to sodium alginate and seaweed extracts in the serum of 4.5 per cent of the work force. Challenge testing of a number of employees with symptoms showed a dual response with immediate airways obstruction, and a later loss of lung volume, with associated impairment of transfer factor.

Alginates↗
PubMed1983

Definitive nonsurgical therapy of epithelial malignancies of the anal canal. A report of 12 cases.

Twelve patients with epidermoid carcinoma of the anal region ranging in age from 40-89 years were treated with combined chemotherapy (CT) and radiotherapy (RT) in lieu of abdominal-perineal resection. Ten patients received no prior treatment and two patients were treated for local recurrence following limited surgical excision. Two courses of 5-FU infusion and mitomycin C were given 3-4 weeks apart simultaneously with whole pelvis RT to 3000-4140 rad. One patient received an additional tumor volume dose of 3094 rad by interstitial Iridium implant and one patient received an orthovoltage boost of 1000 rad to the anal ring. All patients completed treatment. Complete regression of the anal mass occurred in all patients. Biopsies of the anal region performed after completion of therapy revealed no evidence of residual cancer. Ten of the 12 patients are alive without evidence of disease 4-24 months (median, 14 months) after completion of treatment. Two patients have died seven months after treatment of unrelated causes and were tumor-free at autopsy. All patients developed proctitis, diarrhea, and moist perineal desquamation which resolved by four weeks posttreatment. Based on their experience and that of others recently reported, the authors conclude that the described CT-RT protocol offers a definitive alternative to surgery of epidermoid cancer of the anal region.

Adult↗
PubMed1981

Sex hormone binding globulin: effect of synthetic steroids on the assay and effect of oral contraceptives.

The effect that synthetic steroid components of different oral contraceptives have on the assay system for measurement of sex hormones binding globulin (SHBG)-binding capacity, has been examined. Interference with the assay was not demonstrable at therapeutic levels of the drugs. d-Norgestrel was the only steroid studied which bound to SHBG with an affinity comparable to the endogenous sex hormones; it also tended to decrease SHBG-finding capacity, whereas preparations containing low levels of norethisterone increased the binding capacity. We suggest that measurement of changes in SHBG-binding capacity in subjects taking oral contraceptives may prove useful in indicating changes in sex hormone balance, particularly in view of the well-recognised side-effect of these drugs.

Contraceptives, Oral↗
PubMed1977

The effect of human pregnancy on the pulmonary transfer factor for carbon monoxide as measured by the single-breath method.

1. The pulmonary transfer factor for carbon monoxide was measured by the single-breath method in 21 pregnant women with no previous history of cardiac or respiratory disease. Measurements were made at monthly intervals throughout pregnancy and once post partum. 2. The transfer factor was higher in the first trimester of pregnancy than in the non-pregnant state. There was a fall in the transfer factor during pregnancy until 26 weeks gestation, after which no further decrease was observed. 3. The changes in transfer factor were not explained by alterations in haemoglobin concentration or alveolar volume. 4. Simultaneous serial estimation of plasma 17beta-oestradiol were performed in all the subjects. There was no obvious direct relation between changes in the concentration of this hormone and transfer factor measurements.

Adult↗