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Biomedical subjects

M Rodgers

Publications and source records attributed to M Rodgers.

At least 37 records · Page 2Linked to original sources
PubMed2001

The impact of a clinical pathway for gastric bypass surgery on resource utilization.

BACKGROUND: Clinical pathways are believed to improve patient care and reduce costs. Our hypothesis was that a gastric bypass pathway would decrease hospital resource utilization and cost of care without adversely affecting patient care. METHODS: The prepathway (Pre) group consisted of 16 gastric bypasses (6/98 to 3/99). The postpathway (Post) group includes 12 gastric bypass procedures performed after institution of the clinical pathway (4/99 to 12/99). The impact of the clinical pathway on hospital length of stay (LOS) and resource utilization was investigated. A comparison of costs was performed using cost/charge ratios. Hospital readmissions and postoperative complications were also examined. RESULTS: Despite increased obesity/medical acuity of the Post group, hospital LOS decreased by 3 days (P < 0.0001). Total hospital costs decreased by over $1600/case (>15%). Postpathway savings were greatest for room and board (34%), supplies (41%), and lab/radiology costs (50%). An increase in OR costs (22%) was observed in the Post group. This was due to an increase in anesthesia time (epidural catheter placement) and equipment costs (ultrasonic shears). Despite reductions in hospital LOS and resource utilization, the complication rate (Pre 12%, Post 16%) was similar and two patients in each group required brief readmission. CONCLUSIONS: A pathway for gastric bypass decreased hospital LOS and resource utilization. OR-related expenses account for 34-50% of total costs and must be monitored closely for surgical patients. The reduction in costs observed with this clinical pathway was not associated with an increase in postoperative complications or hospital readmission.

Adult↗
PubMed2001

Percolation testing and hydraulic conductivity of soils for percolation areas.

The results of specific percolation tests are expressed in terms of field saturated hydraulic conductivity (Kfs) of the soil. The specific tests comprise the Irish SR 6 and the UK BS 6297 standard tests and the inversed auger hole and square hole tests employed for the design of land drainage. Percolation times from these tests are converted to Kfs values using unit gradient theory and the Elrick and Reynolds (Soil Sci. 142(5) (1986) 308) model which takes into account gravitational, pressure head and matric potential gradients. Kfs is then expressed as the inverse of the percolation rate times a constant, in this way the percolation rate can be directly related to Kfs of the soil. A plot of Kfs against percolation rate for the Irish SR 6 and the UK BS 6297 standard tests is asymptotic at Kfs values less than 0.2 m/d and greater than 0.8 m/d. This behaviour creates difficulty in setting limits for percolation rates in standards. Curves are provided which enable Kfs values to be read off from percolation tests without the restrictions of head range currently enforced, for example in the Irish SR 6 and BS 6297 standards. Experimental measurements of percolation rates and Kfs were carried out on two sands in the laboratory and in the field on two soils. Kfs of these four materials was also measured using a tension infiltrometer and the Guelph permeameter. The saturated hydraulic conductivities (Ks) of the sands were also estimated in a falling head laboratory apparatus and by the Hazen formula. There was good agreement between the different tests for Kfs on each material. Because percolation time continued to increase significantly in consecutive tests in the same test hole while Kfs became constant, the latter is a better measure of the suitability of soils for percolation.

Models, Theoretical↗
PubMed2001

Carbonaceous oxidation using a new vertically moving biofilm system.

This laboratory study consisted of the construction and testing of a new experimental biofilm system for the carbonaceous oxidation of a synthetic wastewater. In the system, a biofilm cuboid module with a high surface area was vertically and repeatedly immersed in and lifted out of the wastewater in a reactor. The performance of two different biofilm modules were compared: one module was constructed from crossflow corrugated plastic sheets with a specific surface area of 410 m2m(-3) and had a calculated surface area of 6.24 m2; the other consisted of honeycombed plastic with hexagonal vertical columns and an estimated surface area of about 2.8 m2. Filtered chemical oxygen demand (COD) removal rates per bulk fluid volume for the corrugated and honeycombed modules of 7.2 kg COD m(-3) d(-1) and 7.6 kg COD m(-3) d(-1) were respectively achieved and these rates compare favourably with other wastewater treatment systems. The new biofilm system was simple to construct and operate, and was very effective in removing biodegradable COD from the synthetic wastewater. The system offers potential for reduced reactor volumes, energy saving, low solids production and easy solids removal.

Biodegradation, Environmental↗
PubMed2000

Resistance patterns of urinary tract infections diagnosed in a genitourinary medicine clinic.

We aimed to assess the prevalence of antibiotic resistance amongst urinary tract isolates within our clinic. Local protocol has been to prescribe a 3-day course of trimethoprim for uncomplicated urinary tract infections (UTIs). Notes of all culture-proven UTIs (October 1998 to September 1999) were examined. Eighty-six urinary isolates were identified in 84 patients. Seventy-three of the isolates were coliforms with 46 being Escherichia coli. Of the 86 urinary isolates 28 (32.6%) were resistant to trimethoprim, 37 (43.5%) to amoxycillin, 5 (5.8%) to cephradine and 3 (3.5%) to nitrofurantoin. Seventy-four (86%) of the UTIs were known to have been treated; 41 at initial presentation and 33 once sensitivities were available. Of the 41 patients who received treatment initially, 11 needed to return to the clinic for a further course of antibiotics. To try and reduce the number of inappropriate treatments and unnecessary visits a number of options regarding clinic protocol were explored.

Adolescent↗
PubMed2000

Technique for cloning and sequencing the ends of bacterial artificial chromosome inserts.

Bacterial artificial chromosome (BAC) libraries are an important tool for positional cloning, gene analysis and physical mapping. During studies using BAC clones, it is often necessary to organize them into contiguous sequences (contigs). To finalize, join and extend the contigs, both cloning and sequencing of the ends of the inserts are required. Here, we describe a low-cost, accessible, fast and powerful method for the routine isolation of BAC ends. This method allows the isolation of 20 BAC clone ends in one day. The analysis of the ends reveals fragment sizes compatible with sequencing, and the structure of these clones allows the sequencing of both ends using the same plasmid. Moreover, long end fragments can be sequenced in both directions.

Chromosomes, Artificial, Bacterial↗
PubMed2000

Reviewing the mid-year population estimates in Northern Ireland.

This article describes the thorough review of the mid-year population estimates for Northern Ireland. No major problems have been identified with the current estimates but a number of enhancements have been put in place. The new figures are consistent with a number of administrative data sources. The overall effect has been to revise the estimated Northern Ireland population by about 6,000 people, or between 0.3 and 0.4 per cent, for each year between 1991 and 1997. The revised estimates for Northern Ireland have been incorporated into the population figures for the United Kingdom included in the Table section of this issue of Population Trends.

Adolescent↗
PubMed1999

Characterization and subcellular compartmentation of recombinant 4-hydroxyphenylpyruvate dioxygenase from Arabidopsis in transgenic tobacco.

4-Hydroxyphenylpyruvate dioxygenase (4HPPD) catalyzes the formation of homogentisate (2,5-dihydroxyphenylacetate) from p-hydroxyphenylpyruvate and molecular oxygen. In plants this enzyme activity is involved in two distinct metabolic processes, the biosynthesis of prenylquinones and the catabolism of tyrosine. We report here the molecular and biochemical characterization of an Arabidopsis 4HPPD and the compartmentation of the recombinant protein in chlorophyllous tissues. We isolated a 1508-bp cDNA with one large open reading frame of 1338 bp. Southern analysis strongly suggested that this Arabidopsis 4HPPD is encoded by a single-copy gene. We investigated the biochemical characteristics of this 4HPPD by overproducing the recombinant protein in Escherichia coli JM105. The subcellular localization of the recombinant 4HPPD in chlorophyllous tissues was examined by overexpressing its complete coding sequence in transgenic tobacco (Nicotiana tabacum), using Agrobacterium tumefaciens transformation. We performed western analyses for the immunodetection of protein extracts from purified chloroplasts and total leaf extracts and for the immunocytochemistry on tissue sections. These analyses clearly revealed that 4HPPD was confined to the cytosol compartment, not targeted to the chloroplast. Western analyses confirmed the presence of a cytosolic form of 4HPPD in cultured green Arabidopsis cells.

4-Hydroxyphenylpyruvate Dioxygenase↗
PubMed1998

Definition of family of coronin-related proteins conserved between humans and mice: close genetic linkage between coronin-2 and CD45-associated protein.

Cell adhesion and signal transduction are coordinated processes that may be linked through regulatory elements such as actin-binding proteins. One such protein that may fulfill this role is coronin. In Dictyostelium discoideum, coronin is involved in cellular processes such as mitosis, cell motility, and phagocytosis. In addition, a human coronin, p57, has been described which interacts with the p47 component of phox proteins and may be involved in the formation of phagocytic vacuoles. Here, we describe a family of four mouse proteins which share 38% identity with Dictyostelium coronin and thus are designated coronin-1, -2, -3, and -4. The gene for coronin-2 is localized to mouse chromosome 19, 5' of the gene for CD45-associated protein. All the coronin proteins contain five highly conserved WD domains. However, their carboxyl regions are quite distinct. Three of the four proteins are ubiquitously expressed, whereas coronin-1, the mouse ortholog of p57, demonstrates expression restricted to hematopoietic cells. Comparison of expressed sequence tag cDNAs indicates that coronin-1, -2, -3, and -4 are highly conserved between mice and humans.

Amino Acid Sequence↗
PubMed1998

Co-trimoxazole desensitization in HIV-seropositive patients.

Co-trimoxazole (trimethoprim-sulphamethoxazole) is an effective prophylactic agent against Pneumocystis carinii pneumonia (PCP). However, it is associated with a high frequency of adverse reactions in immunocompromised patients which may preclude its use. Fourteen patients with a definite history of adverse reactions to co-trimoxazole on standard PCP prophylactic dosage were selected for desensitization using a regimen of gradual incremental exposure over an 11-day period. Eight (57.1%) were successfully desensitized and have continued on oral co-trimoxazole at maximum 21 months' follow-up. This report demonstrates that oral desensitization as an outpatient procedure is an effective and safe option for both primary and secondary PCP prophylaxis in HIV-seropositive patients with previous adverse drug reactions.

Adult↗
PubMed1997

Subcellular localization and purification of a p-hydroxyphenylpyruvate dioxygenase from cultured carrot cells and characterization of the corresponding cDNA.

p-Hydroxyphenylpyruvate dioxygenase catalyses the transformation of p-hydroxyphenylpyruvate into homogentisate. In plants this enzyme has a crucial role because homogentisate is the aromatic precursor of all prenylquinones. Furthermore this enzyme was recently identified as the molecular target for new families of potent herbicides. In this study we examine precisely the localization of p-hydroxyphenylpyruvate dioxygenase activity within carrot cells. Our results provide evidence that, in cultured carrot cells, p-hydroxyphenylpyruvate dioxygenase is associated with the cytosol. Purification and SDS/PAGE analysis of this enzyme revealed that its activity is associated with a polypeptide of 45-46 kDa. This protein specifically cross-reacts with an antiserum raised against the p-hydroxyphenylpyruvate dioxygenase of Pseudomonas fluorescens. Gel-filtration chromatography indicates that the enzyme behaves as a homodimer. We also report the isolation and nucleotide sequence of a cDNA encoding a carrot p-hydroxyphenylpyruvate dioxygenase. The nucleotide sequence (1684 bp) encodes a protein of 442 amino acid residues with a molecular mass of 48094 Da and shows specific C-terminal regions of similarity with other p-hydroxyphenylpyruvate dioxygenases. This cDNA encodes a functional p-hydroxyphenylpyruvate dioxygenase, as evidenced by expression studies with transformed Escherichia coli cells. Comparison of the N-terminal sequence of the 45-46 kDa polypeptide purified from carrot cells with the deduced peptide sequence of the cDNA confirms that this polypeptide supports p-hydroxyphenylpyruvate dioxygenase activity. Immunodetection studies of the native enzyme in carrot cellular extracts reveal that N-terminal proteolysis occurs during the process of purification. This proteolysis explains the difference in molecular masses between the purified protein and the deduced polypeptide.

4-Hydroxyphenylpyruvate Dioxygenase↗
PubMed1997

Adequacy of hormone replacement therapy for osteoporosis prevention assessed by serum oestradiol measurement, and the degree of association with menopausal symptoms.

BACKGROUND: Patients on hormone replacement therapy (HRT) for osteoporosis prevention rather than menopausal symptom control may be asymptomatic, despite inadequate replacement and low serum oestradiol (E2) levels. In the primary health care setting, therapeutic monitoring of HRT is not carried out routinely so that patients with serum E2 levels inadequate to protect bone may be missed. AIM: To determine the proportion of women on transdermal E2 preparations with serum E2 levels insufficient to protect bone and to assess the value of a questionnaire-derived menopausal symptom score (MSS) for detecting these patients. METHOD: A cross-sectional analysis of 45 patients aged 35-70 years using transdermal E2 preparations obtained from a computer register of 14500 patients in a suburban practice. One blood sample was obtained from each patient at the time the MSS questionnaire was completed. Serum E2 concentration was measured using a fluoroimmunoassay and compared with the MSS. Levels below 150 pmol/l were considered to be insufficient to protect bone. The diagnostic accuracy of the MSS in screening for levels below 150 pmol/l was determined using receiver operating characteristic (ROC) curve analysis. RESULTS: The median (95% CI) serum E2 was 147 pmol/l (126-198 pmol/l) and levels were below 150 pmol/l in 24 out of 45 patients. There was no difference in the MSS (median, 95% CI) between those with serum E2 < 150 pmol/l (8.5, 5.0-17) and > or = 150 pmol/l (9.0, 5.0-14; P = 0.477). The degree of association between the serum E2 and the MSS, using the Spearman rank correlation coefficient, rs (95% CI) was small and not significant (-0.04, -0.34 to 0.26; P = 0.398). ROC curve analysis revealed an area under the curve (95% CI) of 0.51 (0.33-0.68). CONCLUSIONS: More than half the women were inadequately replaced to protect against osteoporosis. Furthermore, the MSS was of no value in screening for those with low serum E2 levels. Serum E2 levels should be monitored in women on HRT for osteoporosis prevention and the E2 dosage adjusted accordingly.

Adult↗
PubMed1995

In-vitro biopotency and glycoform distribution of recombinant human follicle stimulating hormone (Org 32489), Metrodin and Metrodin-HP.

In this study the in-vitro biopotency and glycoform distribution of human recombinant follicle stimulating hormone (FSH, Org 32489) has been assessed. The biopotency of recombinant FSH was studied using animal (rat Sertoli) and human (granulosa-lutein) cell models. Recombinant FSH, as measured in the rat Sertoli cell assay, was more potent than the urinary preparations Metrodin, Metrodin-HP and IS 70/45 with half maximal stimulation (ED50; mean +/- SEM, n > 3) occurring at 2.2 +/- 0.5 IU/I (recombinant FSH), 4.7 +/- 1.1 IU/I (Metrodin), 13.2 +/- 0.7 IU/I (Metrodin-HP) and 6.4 +/- 0.3 IU/I (IS 70/45); the pituitary preparation IRP 83/575 had an ED50 of 10.4 +/- 0.1 IU/I. Using human granulosa-lutein cells, cultured for up to 4 days in the absence of exogenous steroid precursors, recombinant FSH was either without effect (three out of five patients) or inhibited both oestradiol and progesterone secretion. FSH (83/575) was without effect on oestradiol with preparations from any of the patients but slightly stimulated (134 +/- 8%; mean +/- SEM, P < 0.05) progesterone production at the highest dose (80 IU/I). The distribution of FSH isoforms, assessed by polyclonal radioimmunoassay, following chromatofocusing over the ranges pH < 3.5 and pH 3.5-7.0 respectively was recombinant FSH, 12.4 and 87.6%; Metrodin, 19.8 and 80.2%; Metrodin-HP, 50.2 and 49.8%; IS 70/45, 15.0 and 85.0%; IS 83/575, 70.9 and 29.1%. All glycoforms were pI < 7.0 for the five preparations.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Variability in the immunoreactive and bioactive follicle stimulating hormone content of human urinary menopausal gonadotrophin preparations.

The within- and between-batch variation in the immunoreactive and in-vitro bioactive FSH content of Pergonal, Metrodin and Metrodin-HP was investigated. Three batches of Pergonal and Metrodin, consisting of three ampoules in each batch, and three batches of Metrodin-HP, consisting of between one and three ampoules per batch, were selected at random. The follicle stimulating hormone (FSH) content of Pergonal, Metrodin and Metrodin-HP was determined by radioimmunoassay (R-FSH) and the in-vitro rat Sertoli cell bioassay (B-FSH) using the international urinary standard 70/45. The variability in the FSH content of the preparations was evaluated within and between batches by analysis of variance. Within-batch variability of B-FSH was not observed in Pergonal or Metrodin-HP but was seen in two batches of Metrodin in which the potency varied by up to 2.4 fold (P = 0.03). The between-batch R-FSH potencies of Pergonal (P1-P3) varied, with P2 (59.8 +/- 0.6) and P3 (61.7 +/- 0.9) being higher than P1 (47.1 +/- 1.5 mean +/- SEM IU/ampoule, P < 0.01). A similar pattern of variability was observed for B-FSH. For Metrodin, each of the batch R-FSH potencies was dissimilar (P < 0.02), with estimates ranging from 34.9 +/- 1.2 to 64.3 +/- 1.8 IU/ampoule. Furthermore, the extensive within-batch B-FSH variation from two batches confounded any meaningful comparison of between-batch variability. For Metrodin-HP, there was no between-batch B-FSH variation (29.0 +/- 6.1 to 33.0 +/- 0.3 IU/ampoule) and the R-FSH content was also well controlled (41.2 +/- 0.5 to 46.9 +/- 1.1 IU/ampoule).(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1994

Accumulation of human chorionic gonadotrophin in the serum of patients during in-vitro fertilization treatment cycles with Pergonal.

We examined the possible contribution of human chorionic gonadotrophin (HCG) in Pergonal to the serum luteinizing hormone (LH)-like bioactivity in 10 patients (median age 32 years, range 28-38) with tubal infertility who were undergoing in-vitro fertilization (IVF), together with 19 controls (median age 30 years, range 21-43). IVF patients were treated with clomiphene (50 mg twice daily) over days 2-6 and Pergonal (150 IU i.m.) daily from day 5 until at least day 10. Serum LH was measured by fluoro-immunometric assay (I-LH) and in-vitro Leydig cell bioassay (B-LH). Serum HCG was measured by fluoro-immunometric assay. The data were analysed by paired two-tailed t-test, following logarithmic transformation. From days 1-5, there was an increase in serum B-LH (mean, 95% confidence intervals given in parentheses) from 8.3 (6.8, 10.2) IU/l to 11.7 (9.8, 13.9) IU/l [P = 0.004], and in serum I-LH from 4.5 (3.7, 5.4) IU/l to 5.4 (4.6, 6.3) IU/l [P = 0.002]. From days 5-8, there was a rise in B-LH to 16.6 (12.6, 21.9) IU/l [P = 0.023]. The rise in I-LH to 6.3 (5.1, 7.8) IU/l [P = 0.081] failed to reach significance. Furthermore, serum HCG was < 0.75 IU/l until after Pergonal was administered on day 5, then rose to a plateau on day 8 at 1.2 (0.8, 1.6) IU/l. Serum HCG in the controls remained < 0.75 IU/l throughout.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗