PubMed Health⌕ Search

Biomedical subjects

V Hall

Publications and source records attributed to V Hall.

At least 19 recordsLinked to original sources
PubMed2005

Antimicrobial susceptibility testing of Actinomyces species with 12 antimicrobial agents.

OBJECTIVE: This study was conducted to assess the susceptibility of human clinical isolates of Actinomyces species to 12 antimicrobial agents. METHODS: Human clinical isolates of Actinomyces spp. were collected from stored collections held at the Microbiology Department, Edinburgh University, Anaerobe Reference Laboratory, Cardiff, Glasgow Dental Hospital and Glasgow Royal Infirmary. Each isolate was identified by restriction analysis of amplified 16S ribosomal DNA. MICs of 12 antibiotics comprising benzyl penicillin, amoxicillin, ceftriaxone, linezolid, tetracycline, deoxycycline, clindamycin, erythromycin, clarithromycin, ciprofloxacin, meropenem and piperacillin/tazobactam for 87 strains of Actinomyces species were obtained by Etest methodology. RESULTS: The Actinomyces species identified for this study comprised: Actinomyces israelii, Actinomyces gerencseriae, Actinomyces turicensis, Actinomyces funkei, Actinomyces graevenitzii and Actinomyces europaeus. All isolates were susceptible to penicillin and amoxicillin. All but one strain of A. turicensis was susceptible to linezolid. A number of A. europaeus and A. graevenitzii isolates were resistant to ceftriaxone and piperacillin/tazobactam. A number of isolates of A. turicensis and A. europaeus also demonstrated resistance to erythromycin. All Actinomyces species tested appeared resistant to ciprofloxacin. CONCLUSIONS: Actinomyces species appear to be susceptible to a wide range of beta-lactam agents and these, when combined with beta-lactamase inhibitors, should be regarded as agents of first choice. Ciprofloxacin performed poorly. Tetracyclines also demonstrated poor performance. This is the first study of antimicrobial susceptibilities for a number of accurately identified clinical isolates of Actinomyces spp. There are a number of species differences in susceptibility profiles to the antimicrobials tested, suggesting that accurate identification and speciation may have an impact on clinical outcome.

Actinomyces↗
PubMed2005

Visual functioning and quality of life in the SubFoveal Radiotherapy Study (SFRADS): SFRADS report 2.

AIMS: To determine whether or not self reported visual functioning and quality of life in patients with choroidal neovascularisation caused by age related macular degeneration (AMD) is better in those treated with 12 Gy external beam radiotherapy in comparison with untreated subjects. METHODS: A multicentre single masked randomised controlled trial of 12 Gy of external beam radiation therapy (EBRT) delivered as 6 x 2 Gy fractions to the macula of an affected eye versus observation. Patients with AMD, aged 60 years or over, in three UK hospital units, who had subfoveal CNV and a visual acuity equal to or better than 6/60 (logMAR 1.0). METHODS: Data from 199 eligible participants who were randomly assigned to 12 Gy teletherapy or observation were available for analysis. Visual function assessment, ophthalmic examination, and fundus fluorescein angiography were undertaken at baseline and at 3, 6, 12, and 24 months after study entry. To assess patient centred outcomes, subjects were asked to complete the Daily Living Tasks Dependent on Vision (DLTV) and the SF-36 questionnaires at baseline, 6, 12, and 24 months after enrolment to the study. Cross sectional and longitudinal analyses were conducted using arm of study as grouping variable. Regression analysis was employed to adjust for the effect of baseline co-variates on outcome at 12 months and 24 months. RESULTS: Both control and treated subjects had significant losses in visual functioning as seen by a progressive decline in mean scores in the four dimensions of the DLTV. There were no statistically significant differences between treatment and control subjects in any of dimensions of the DLTV at 12 months or 24 months after study entry. Regression analysis confirmed that treatment status had no effect on the change in DLTV dimensional scores. CONCLUSIONS: The small benefits noted in clinical measures of vision in treated eyes did not translate into better self reported visual functioning in patients who received treatment when compared with the control arm. These findings have implications for the design of future clinical trials and studies.

Activities of Daily Living↗
PubMed2004

Outbreak of Clostridium histolyticum infections in injecting drug users in England and Scotland.

Clostridial infections in injecting drug users in the United Kingdom are a relatively new phenomenon that came to light in 2000 when cases of serious illness and deaths due to Clostridium novyi were recorded. In the period December 2003 to April 2004, the Anaerobe Reference Laboratory received twelve referrals of an extremely rare isolate, Clostridium histolyticum, from cases of infection in injecting drug users submitted from nine different hospitals in England and Scotland. Molecular typing of these isolates by two different methods of pulsed-field gel electrophoresis and PCR ribotyping revealed they are all indistinguishable, indicating a common source of the infections, most probably a batch of heroin that was recently distributed across the UK.

Adult↗
PubMed2003

Antibiotic susceptibilities of Gram-positive anaerobic cocci: results of a sentinel study in England and Wales.

OBJECTIVE: A sentinel study was carried out to determine the antimicrobial susceptibilities of Gram-positive anaerobic cocci (GPAC) freshly isolated from clinical material in diagnostic laboratories in England and Wales. METHODS: A total of 113 GPAC isolates consisting predominantly of current or former members of the genus Peptostreptococcus was obtained from 17 sentinel laboratories in England and one in Wales. Minimum inhibitory concentrations (MICs) of 10 antimicrobial agents were determined by the Etest method. The agents tested were: penicillin, tetracycline, erythromycin, cefoxitin, clindamycin, chloramphenicol, imipenem, co-amoxiclav, piperacillin/tazobactam and metronidazole. MIC50 and MIC90 values for each drug-species combination were calculated whenever suitable numbers of each species were obtained. RESULTS: Excellent spectra of activity (0% resistance) against GPAC were seen for metronidazole, piperacillin/tazobactam, cefoxitin, imipenem and chloramphenicol. Low degrees of resistance to co-amoxiclav (3.5%), clindamycin (7.1%), penicillin (7.1%) and significant degrees of resistance to tetracycline (41.6%) and erythromycin (27.4%) were detected. Some examples of putative macrolide-lincosamide linked resistance were noted in seven (6.2%) isolates of GPAC. CONCLUSION: This study is one of the largest susceptibility studies specifically on GPAC carried out to date and the resulting data may be of value to those involved in the empirical treatment of infections involving Gram-positive anaerobic cocci.

Anti-Bacterial Agents↗
PubMed2003

Serum osteoprotegerin as a determinant of bone metabolism in a longitudinal study of human pregnancy and lactation.

Osteoprotegerin (OPG) is a soluble decoy receptor that inhibits bone resorption by binding to receptor activator of nuclear factor kappa B ligand. Murine studies suggest that OPG is elevated in pregnancy, but its role in human pregnancy is unknown. We evaluated the relationship among OPG, bone turnover, and bone density in a longitudinal study of planned human pregnancy and lactation (n = 17; age, 20-36 yr). Samples were collected before conception; at 16, 26, and 36 wk gestation; and at 2 and 12 wk postpartum. Indexes of bone resorption included serum beta C-terminal and urinary N-terminal (uNTX) telopeptides of type I collagen. OPG increased by 110 +/- 16% (mean +/- SEM) at 36 wk (P < 0.001), followed by a rapid postpartum decline in both lactating and nonlactating women. Bone resorption was elevated at 36 wk (serum beta C-terminal telopeptides by 76 +/- 17%; urinary N-terminal telopeptides by 219 +/- 41%; P < 0.001). The tissue source of OPG in pregnancy is unknown. Human breast milk contains large amounts of OPG (162 +/- 58 ng/ml in milk vs. 0.42 +/- 0.03 ng/ml in nonpregnant serum). However, the rapid postpartum decline in serum OPG and the low serum OPG in neonates suggest a placental source. There was no correlation between change in OPG and bone turnover or bone mineral density (P > 0.05), and the physiological importance of elevated OPG in human pregnancy remains uncertain.

Adult↗
PubMed2002

Visual outcomes in the subfoveal radiotherapy study: a randomized controlled trial of teletherapy for age-related macular degeneration.

OBJECTIVE: To determine whether teletherapy with 6-mV photons can reduce visual loss in patients with subfoveal choroidal neovascularization in age-related macular degeneration. DESIGN: A multicenter, single-masked, randomized controlled trial of 12 Gy of external beam radiation therapy delivered to the macula of an affected eye vs observation only. SETTING: Three United Kingdom-based hospital units. PARTICIPANTS: Patients with age-related macular degeneration, aged 60 years and older, who had subfoveal choroidal neovascularization and a visual acuity of 20/200 (logMAR 1.0) or better. METHODS: Two hundred three patients were randomly assigned to radiotherapy or observation. Treatment was undertaken at designated radiotherapy centers, and patients assigned to the treatment group received a total dosage of 12 Gy of 6-mV photons in 6 fractions. Follow-up was scheduled at 3, 6, 12, and 24 months. After excluding protocol violators, the data from 199 patients were analyzed. MAIN OUTCOME MEASURES: The primary outcome measure was mean loss of distance visual acuity in the study eye at 12 and 24 months. Other outcome variables analyzed were near visual acuity and contrast sensitivity. The proportions of patients losing 3 or more or 6 or more lines of distance and near acuity and 0.3 or more or 0.6 or more log units of contrast sensitivity at each follow-up were also analyzed. RESULTS: At all time points, mean distance visual acuity was better in the radiotherapy-treated group than in the control group, but the differences did not reach statistical significance. At 24 months, analysis of the proportions of patients with loss of 3 or more (moderate) (P =.08) or 6 or more (severe) (P =.29) lines of distance vision showed that fewer treated patients had severe losses, but there was no statistically significant difference between groups. For near visual acuity, although there was no evidence of treatment benefit at 12 and 24 months, a significant difference in favor of treatment was present at 6 months (P =.048). When analyzed by the proportions of patients losing 3 lines of contrast sensitivity, there was a significant difference in favor of treatment at 24 months (P =.02). No adverse retinal effects were observed during the study, but transient disturbance of the precorneal tear film was noted in treated patients. CONCLUSION: The results of the present trial do not support the routine clinical use of external beam radiation therapy in subjects with subfoveal choroidal neovascularization in age-related macular degeneration.

Aged↗
PubMed2002

Superior venocaval obstruction secondary to central venous catheter-related thromboses in two patients with metastatic colorectal carcinoma receiving weekly 5-flurouracil. Should adjusted-dose warfarin be used as thromboprophylaxis?

Standard treatment for patients with metastatic colorectal carcinoma (MCC) involves treatment with weekly 5-flurouracil (5-FU) chemotherapy by continuous infusion, requiring the insertion of a central venous catheter (CVC). One of the main complications of CVCs is venous thromboembolic disease (VTE), with an incidence varying between 3 and 54% in different studies. During the past 14 months, 17 patients with MCC have been treated weekly with 5-FU in our unit, comprising 11 males and six females with a mean age of 60 years (range, 49-72 years). Thromboprophylaxis for all patients included 1 mg/day warfarin unless contraindicated. Three patients developed venography-confirmed CVC-related VTE, including two cases of occlusive superior venocaval VTE. All three patients were treated with intravenous thrombolytic drugs; two responded completely and one partially. We wonder whether the incidence of CVC-related VTE may be reduced further by using adjusted-dose warfarin rather than fixed low-dose warfarin. However, one has to be guarded because of the greater risk of bleeding with more intensive anticoagulation, especially in patients with liver metastases. Ongoing studies such as the warfarin prophylaxis study are essential to determine the safety and efficacy of different approaches in order to determine the optimum thromboprophylaxis for this group of patients.

Aged↗
PubMed2002

Heterogeneity within the gram-positive anaerobic cocci demonstrated by analysis of 16S-23S intergenic ribosomal RNA polymorphisms.

Peptostreptococci are gram-positive, strictly anaerobic bacteria which, although regarded as members of the commensal human microflora, are also frequently isolated from sites of clinical infection. The study of this diverse group of opportunist pathogens has been hindered by an inadequate taxonomy and the lack of a valid identification scheme. Recent re-classification of the Peptostreptococcus family into five distinct genus groups has helped to clarify the situation. However, this has been on the basis of 16S rRNA sequence determinations, which are both time-consuming and expensive. The aim of the present study was to evaluate the use of PCR-amplified ribosomal DNA spacer polymorphisms for the rapid differentiation of the currently recognised taxa within the group of anaerobic gram-positive cocci. A collection comprising 19 reference strains with representatives of each of the 15 species, two close relatives and two of the well-characterised groups, together with 38 test strains was studied. All strains were identified to species group level by phenotypic means. Amplification of the 16S-23S intergenic spacer region (ISR) with universal primers produced distinct banding patterns for all the 19 reference strains and the patterns could be differentiated easily visually. However, of the 38 test strains, less than half could be speciated from ISR analysis alone. Only five groups produced correlating banding patterns for all members tested (Peptoniphilus lacrimalis, P. ivorii, Anaerococcus octavius, Peptostreptococcus anaerobius and Micromonas micros). For other species, either the type strain differed significantly from other species members (e.g., A. hydrogenalis) or there appeared to be considerable intra-species variation (e.g., A. vaginalis). Partial 16S rRNA gene sequences for the 'trisimilis' and 'betaGAL' groups showed that both are most closely related to the Anaerococcus group. This work highlights the heterogeneous nature of a number of Peptostreptococcus species and hence the need for still further revision of the taxonomy of this important group of pathogens.

Anaerobiosis↗
PubMed2002

Isolation and identification of Clostridium spp. from infections associated with the injection of drugs: experiences of a microbiological investigation team.

Pathogenic species of the genus Clostridium may contaminate the materials used in the injection of drugs and under the right conditions may cause serious or life-threatening disease. C. novyi type A was implicated in an outbreak of severe infection with high mortality in injecting drug users who injected heroin extravascularly. The isolation of such highly oxygen-sensitive clostridia from clinical material may require adherence to enhanced methods and, once isolated, commercially available anaerobe identification kits alone may not give an accurate identification. Additional phenotypic tests that are useful in recognising the main pathogenic species are described. Differentiation of C. novyi type A from C. botulinum type C in reference laboratories was based on 16S rDNA sequence data and specific neutralisation of cytopathic effects in tissue culture.

Bacterial Typing Techniques↗
PubMed2002

Fusobacterium necrophorum infections in England and Wales 1990-2000.

In response to a marked increase in both the number of Fusobacterium necrophorum bacteraemia reports to the PHLS Communicable Disease Surveillance Centre and the number of F. necrophorum isolates referred to the PHLS Anaerobe Reference Unit in 1999, the data from both sources on F. necrophorum infections were reviewed for the decade 1990-2000. There were 208 reports of F. necrophorum bacteraemia (average 19/year; range 14-34/year) with a peak in incidence in the late winter months; 68% were from male patients and the peak age range was 16-23 years. Of 205 referred isolates of F. necrophorum, 122 (59%) were from blood cultures and these represented 58% of the bacteraemia reports; the others were from brain and soft tissue abscesses, pleural and joint fluids, eyes, ears and lymphatic tissue. The average number of referrals was 19/year (range 9-37/year). The peak year for bacteraemia reports (34) and isolate referrals (37) was 1999; this increase was not sustained in 2000. All isolates were susceptible to metronidazole, but 2% were resistant to penicillin and 15% to erythromycin. F. necrophorum continues to be a regular but uncommon cause of bacteraemia and metastatic abscesses following an acute sore throat, especially in young, otherwise healthy adults.

Abscess↗
PubMed2002

The VALUE national hysterectomy study: description of the patients and their surgery.

OBJECTIVES: To describe hysterectomies practised in 1994 and 1995: the patients, their surgery and short term outcomes. DESIGN: One of two large cohorts, with prospective follow up, recruited to compare the outcomes of endometrial destruction with those of hysterectomy. SETTING: England, Wales and Northern Ireland. POPULATION: All women who had hysterectomies for non-malignant indications carried out during a 12-month period. METHODS: Gynaecologists in NHS and independent hospitals were asked to report cases. Follow up data were obtained at outpatient follow up approximately six weeks post-surgery. MAIN OUTCOME MEASURES: Indication for surgery, method of hysterectomy, ovarian status post-surgery, surgical complications. RESULTS: 37,298 cases were reported which is estimated to reflect about 45% of hysterectomies performed during the period studied. The median age was 45 years, and the most common indication for surgery was dysfunctional uterine bleeding (46%). Most hysterectomies were carried out by consultants (55%). The proportions of women having abdominal, vaginal or laparoscopically-assisted hysterectomy were 67%, 30% and 3%, respectively. Forty-three percent of women had no ovaries conserved after surgery. The median length of stay was five days. The overall operative complication rate was 3.5%, and highest for the laparoscopic techniques. The overall post-operative complication rate was 9%. One percent of these was regarded as severe, with the highest rate for severe in the laparoscopic group (2%). There were no operative deaths; 14 deaths were reported within the six-week post-operative period: a crude mortality rate soon after surgery of 0.38 per thousand (95% CI 0.25-0.64). CONCLUSIONS: This large study describes women who undergo hysterectomy in the UK, and presents results on early complications associated with the surgery. Operative complications occurred in one in 30 women, and post-operative complications in at least one in 10. Laparoscopic techniques tend to be associated with higher complication rates than other methods.

Adolescent↗
PubMed2001

Identification of clinical isolates of actinomyces species by amplified 16S ribosomal DNA restriction analysis.

Amplified 16S ribosomal DNA (rDNA) restriction analysis (ARDRA), using enzymes HaeIII and HpaII, was applied to 176 fresh and 299 stored clinical isolates of putative Actinomyces spp. referred to the Anaerobe Reference Unit of the Public Health Laboratory Service for confirmation of identity. Results were compared with ARDRA results obtained previously for reference strains and with conventional phenotypic reactions. Identities of some strains were confirmed by analysis of partial 16S rDNA sequences. Of the 475 isolates, 331 (70%) were clearly assigned to recognized Actinomyces species, including 94 isolates assigned to six recently described species. A further 52 isolates in 12 ARDRA profiles were designated as apparently resembling recognized species, and 44 isolates, in 18 novel profiles, were confirmed as members of genera other than Actinomyces. The identities of 48 isolates in nine profiles remain uncertain, and they may represent novel species of Actinomyces. For the majority of species, phenotypic results, published reactions for the species, and ARDRA profiles concurred. However, of 113 stored isolates originally identified as A. meyeri or resembling A. meyeri by phenotypic tests, only 21 were confirmed as A. meyeri by ARDRA; 63 were reassigned as A. turicensis, 7 as other recognized species, and 22 as unidentified actinomycetes. Analyses of incidence and clinical associations of Actinomyces spp. add to the currently sparse knowledge of some recently described species.

Actinomyces↗
PubMed2000

Gap junctions in human synovial cells and tissue.

Our objective was to establish the existence of intercellular communication through gap junctions in synovial lining cells and in primary and passaged cultures of human synovial cells. Communication between cells was assessed using the nystatin perforated-patch method, fluorescent dye transfer, immunochemistry, transmission electron microscopy, and immunoblotting. Functional gap junctions were observed in primary and passaged cultures and were based on measurements of the transient current response to a step voltage. The average resistance between cells in small aggregates was 300 +/- 150 MOmega. Gap junctions were also observed between synovial lining cells in tissue explants; the size of the cell network in synovial tissue was estimated to be greater than 40 cells. Intercellular communication between cultured cells and between synovial lining cells was confirmed by dye injection. Punctate fluorescent regions were seen along intercellular contacts between cultured cells and in synovial membranes in cells and tissue immunostained for connexin43. The presence of the protein was verified in immunoblots. Regular 2-nm intermembrane gap separations characteristic of gap junctions were seen in transmission electron micrographs of synovial biopsies. The results showed that formation of gap-junction channels capable of mediating ionic and molecular communication was a regular feature of synovial cells, both in tissue and in cultured cells. The gap junctions contained connexin43 protein and perhaps other proteins. The physiological purpose of gap junctions in synovial cells is unknown, but it is reasonable to anticipate that intercellular communication serves some presently unrecognized function.

Arthritis, Rheumatoid↗
PubMed2000

Analysis of gene transcription in bovine nuclear transfer embryos reconstructed with granulosa cell nuclei.

The low efficiency of animal production using somatic cell nuclear transfer procedures is considered to be the result of an incomplete reprogramming of the donor somatic cell nucleus, which leads to a lack of, or abnormal expression of developmentally important genes. However, our current understanding of the process of somatic cell nuclear reprogramming and its effect on gene expression is limited. In this study, we compare the transcription patterns of six developmentally important genes, Oct4, IL6, FGF2, FGF4, FGFr2, and gp130 in single in vitro fertilized (IVF) and nuclear transfer embryos reconstructed using granulosa cells for the donor nuclei. Similar patterns of transcription were detected for Oct4, FGF2, and gp130 in IVF and nuclear transfer embryos during the preimplantation stages of development. However, a number of morula- and blastocyst-stage embryos derived from nuclear transfer procedures showed abnormal transcription of IL6, FGF4, and FGFr2. Previous studies have demonstrated that these three genes play an important role in implantation, early postimplantation development, or both in the mouse. Therefore, the aberrant transcription patterns detected in nuclear transfer embryos may lead to a reduction in embryo viability.

Animals↗
PubMed2000

Evaluation of a phenotypic scheme for identification of the 'butyrate-producing' Peptostreptococcus species.

Gram-positive anaerobic cocci (GPAC) are isolated from approximately one quarter of all infections involving anaerobic bacteria. However, studies of the significance of this group of pathogens have been hindered by an inadequate taxonomy and the lack of a valid identification scheme. In the present study, a phenotypic scheme for the identification of 'butyrate-producing' GPAC based on the analysis of volatile fatty acid profiles by gas-liquid chromatography, biochemical profiles (including the use of the rapid ID 32 A commercial kit) and carbohydrate fermentation reactions, was evaluated. The identity of 68 clinical isolates of GPAC was determined by application of the scheme published by Murdoch. The scheme was found to be easy to apply and only four of the test isolates could not be readily assigned to a species or well-defined group. The species most frequently identified in the test collection were Peptostreptoccoccus vaginalis, P. tetradius and the betaGAL group. A large number of strains was assigned to the heterogeneous 'prevotii/tetradius' group. Some species regarded as being restricted to particular clinical sites were shown to be more widespread than previously thought. The clinical source of the isolates did not show any consistent correlation with species identity.

Butyrates↗
PubMed2000

A multicentre evaluation of a new surgical technique for urethral bulking in the treatment of genuine stress incontinence.

This prospective study assesses the surgeon and patient acceptability of a new implantation device for transurethral Macroplastique injection, as well as the safety and effectiveness of the technique. Ten women with genuine stress incontinence were recruited at each of four participating urogynaecological centres. Treatment was performed in an outpatient or day case setting and follow up took place at six weeks and three months after treatment. Those in whom treatment had failed were offered re-treatment. The operator acceptance of the device was rated as excellent or acceptable in 95% after the first treatment and 100% after re-treatment. Urethral insertions were rated acceptable in 92.5%. Pain was scored as mild to moderate in 89% of all insertions. The overall success rate was 74.3% at three months with an implantation rate of 1.35 which appears to be comparable to published endoscopic data. We have concluded from this study that the Macroplastique implantation device is safe to use and provides simplified, yet effective alternative to the endoscopic implantation of urethral bulking agents.

Female↗
PubMed1999

Development of amplified 16S ribosomal DNA restriction analysis for identification of Actinomyces species and comparison with pyrolysis-mass spectrometry and conventional biochemical tests.

Identification of Actinomyces spp. by conventional phenotypic methods is notoriously difficult and unreliable. Recently, the application of chemotaxonomic and molecular methods has clarified the taxonomy of the group and has led to the recognition of several new species. A practical and discriminatory identification method is now needed for routine identification of clinical isolates. Amplified 16S ribosomal DNA restriction analysis (ARDRA) was applied to reference strains (n = 27) and clinical isolates (n = 36) of Actinomyces spp. and other gram-positive rods. Clinical strains were identified initially to the species level by conventional biochemical tests. However, given the low degree of confidence in conventional methods, the findings obtained by ARDRA were also compared with those obtained by pyrolysis-mass spectrometry. The ARDRA profiles generated by the combination of HaeIII and HpaII endonuclease digestion differentiated all reference strains to the species or subspecies level. The profiles correlated well with the findings obtained by pyrolysis-mass spectrometry and by conventional tests and enabled the identification of 31 of 36 clinical isolates to the species level. ARDRA was shown to be a simple, rapid, cost-effective, and highly discriminatory method for routine identification of Actinomyces spp. of clinical origin.

Actinomyces↗