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1.
BMJ Surg Interv Health Technol ; 6(1): e000253, 2024.
Article in English | MEDLINE | ID: mdl-38835401

ABSTRACT

Objectives: To investigate the longitudinal trends of decompressive craniectomy (DC) following traumatic brain injury (TBI) or stroke and explore whether the timing of cranial reconstruction affected revision or removal rates using Hospital Episode Statistics (HES) between 2014 and 2019. Design: Retrospective observational cohort study using HES. The time frame definitions mirror those often used in clinical practice. Setting: HES data from neurosurgical centres in England. Participants: HES data related to decompressive craniectomy procedures and cranioplasty following TBI or stroke between 2014 and 2019. Main outcome measures: The primary outcome was the timing and rate of revision/removal compared with cranioplasty within <12 weeks to ≥12 weeks. Results: There were 4627 DC procedures, of which 1847 (40%) were due to head injury, 1116 (24%) were due to stroke, 728 (16%) were due to other cerebrovascular diagnoses, 317 (7%) had mixed diagnosis and 619 (13%) had no pre-specified diagnoses. The number of DC procedures performed per year ranged from 876 in 2014-2015 to 967 in 2018-2019. There were 4466 cranioplasty procedures, with 309 (7%) revisions and/or removals during the first postoperative year. There was a 33% increase in the overall number of cranioplasty procedures performed within 12 weeks, and there were 1823 patients who underwent both craniectomy and cranioplasty during the study period, with 1436 (79%) having a cranioplasty within 1 year. However, relating to the timing of cranial reconstruction, there was no evidence of any difference in the rate of revision or removal surgery in the early timing group (6.5%) compared with standard care (7.9%) (adjusted HR 0.93, 95% CIs 0.61 to 1.43; p=0.75). Conclusions: Overall number of craniectomies and the subsequent requirements for cranioplasty increased steadily during the study period. However, relating to the timing of cranial reconstruction, there was no evidence of an overall difference in the rate of revision or removal surgery in the early timing group.

2.
Brain Spine ; 3: 101735, 2023.
Article in English | MEDLINE | ID: mdl-37383457

ABSTRACT

Background: There is wide-ranging published literature around cranioplasty following traumatic brain injury (TBI) and stroke, but the heterogeneity of outcomes limits the ability for meta-analysis. Consensus on appropriate outcome measures has not been reached, and given the clinical and research interest, a core outcome set (COS) would be beneficial. Objectives: To collate outcomes currently reported across the cranioplasty literature which will subsequently be used in developing a cranioplasty COS. Methods: This systematic review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. All full-text English studies with more than ten patients (prospective) or more than 20 patients (retrospective) published after 1990 examining outcomes in CP were eligible for inclusion. Results: The review included 205 studies from which 202 verbatim outcomes were extracted, grouped into 52 domains, and categorised into one or more of the OMERACT 2.0 framework core area(s). The total numbers of studies that reported outcomes in the core areas are 192 (94%) pathophysiological manifestations/ 114 (56%) resource use/economic impact/ 94 (46%) life impact/mortality 20 (10%). In addition, there are 61 outcome measures used in the 205 studies across all domains. Conclusion: This study shows considerable heterogeneity in the types of outcomes used across the cranioplasty literature, demonstrating the importance and necessity of developing a COS to help standardise reporting across the literature.

3.
Front Surg ; 9: 864385, 2022.
Article in English | MEDLINE | ID: mdl-35656088

ABSTRACT

Decompressive craniectomy (DC) is an operation where a large section of the skull is removed to accommodate brain swelling. Patients who survive will usually require subsequent reconstruction of the skull using either their own bone or an artificial prosthesis, known as cranioplasty. Cranioplasty restores skull integrity but can also improve neurological function. Standard care following DC consists of the performance of cranioplasty several months later as historically, there was a concern that earlier cranioplasty may increase the risk of infection. However, recent systematic reviews have challenged this and have demonstrated that an early cranioplasty (within three months after DC) may enhance neurological recovery. However, patients are often transferred to a rehabilitation unit following their acute index admission and before their cranioplasty. A better understanding of the pathophysiological effects of cranioplasty and the relationship of timing and complications would enable more focused patient tailored rehabilitation programs, thus maximizing the benefit following cranioplasty. This may maximise recovery potential, possibly resulting in improved functional and cognitive gains, enhancement of quality of life and potentially reducing longer-term care needs. This narrative review aims to update multi-disciplinary team regarding cranioplasty, including its history, pathophysiological consequences on recovery, complications, and important clinical considerations both in the acute and rehabilitation settings.

4.
Br J Neurosurg ; 20(5): 301-5, 2006 Oct.
Article in English | MEDLINE | ID: mdl-17129878

ABSTRACT

Guidelines recommend that head-injured patients who require life-saving decompressive surgery should undergo surgery within 4 h. To assess the compliance with this recommendation 100 consecutive head-injured patients admitted to a regional neurosurgical unit (RNU) were studied. Time points from head injury to craniotomy were documented and analysed. Twenty-four patients underwent emergency craniotomy, only one being operated on within 4 h. In this cohort of patients there was no relationship between timing of surgery and outcome. In order to investigate whether it is possible to reduce delays in transportation time, theoretical models were created to determine whether direct transfer to the RNU would be faster by land or air ambulance.


Subject(s)
Craniocerebral Trauma/surgery , Emergency Medical Services/organization & administration , Patient Transfer/organization & administration , Adolescent , Adult , Aged , Aged, 80 and over , Air Ambulances , Ambulances , Craniotomy , Glasgow Coma Scale , Humans , Middle Aged , Models, Organizational , Neurosurgery/organization & administration , Rural Health , Time Factors , Treatment Outcome , United Kingdom
5.
Vaccine ; 22(31-32): 4245-51, 2004 Oct 22.
Article in English | MEDLINE | ID: mdl-15474715

ABSTRACT

The current UK anthrax vaccine is an alum precipitate prepared from static culture filtrate of the avirulent, unencapsulated Sterne strain of Bacillus anthracis. Protective antigen (PA) is regarded as the major immunogen in the vaccine and production conditions are intended to maximize the PA content. However, the precise composition of the vaccine is unknown and there are concerns that the observed side effects of vaccination may be caused by residual enzymatically active toxin components. Two-dimensional gel electrophoresis (2DGE) was used to define the protein components of the current UK anthrax vaccine. Consistency of composition was assessed by examining batches spanning 14 years of vaccine production. The reproducibility of the 2DGE technique was assessed by repeated analysis of selected vaccine batches. For two recently produced batches, between 86.7 and 88.8% of the spots could be matched. However, for one older batch, reproducibility of the spot pattern was considerably less, with a mean similarity of 53.4%. This difference may be explained by a change in production or because of decay during storage. Variation between the recently produced batches ranged from 72.9 to 84.3%, whereas the similarity between these and old batches was comparatively low at between 30 and 59%. Our results demonstrate that, as expected, the major antigen present in the vaccine is PA. The 83 and 63 kDa species are dominant but there are numerous lower molecular weight fragments resulting from proteolytic cleavage. In addition, we have established the presence of the toxin components, oedema factor and lethal factor, and S-layer proteins, EA1 and SAP. Mass spectrometry has also enabled us to identify several bacterial cell-derived proteins present in the vaccine, including PA, enolase, fructose-bisphosphate aldolase, nucleoside diphosphate kinase and a 60 kDa heat shock protein. The use of proteomics can provide useful information on the antigenic make up of this vaccine and the consistency of vaccine production.


Subject(s)
Anthrax Vaccines/chemistry , Adsorption , Animals , Antigens, Bacterial/chemistry , Bacterial Proteins/chemistry , Blotting, Western , Databases, Factual , Electrophoresis, Gel, Two-Dimensional , Isoelectric Focusing , Mass Spectrometry , Mice , Silver Staining
6.
J Med Microbiol ; 51(10): 837-843, 2002 Oct.
Article in English | MEDLINE | ID: mdl-12435062

ABSTRACT

Many pathogenic bacteria express plasminogen receptors on their surface, which may play a role in the dissemination of organisms by binding plasminogen that, when converted to plasmin, can digest extracellular matrix proteins. A 45-kDa protein was purified from Streptococcus pneumoniae and confirmed as an alpha-enolase by its ability to catalyse the dehydration of 2-phospho-D-glycerate to phosphoenolpyruvate and by N-terminal sequencing. The activity of alpha-enolase was found in the cytoplasm and in whole cells. Activity was also demonstrated in cell wall fractions, which confirmed that alpha-enolase is a cytoplasmic antigen also expressed on the surface of S. pneumoniae. The plasminogen-binding activity of alpha-enolase was examined by Western blot, which showed that purified alpha-enolase was able to bind human plasminogen. Immunoblots of the purified 45-kDa alpha-enolase with 22 sera from patients with pneumococcal disease showed binding in 15 cases, indicating that pneumococcal enolase is immunogenic.


Subject(s)
Phosphopyruvate Hydratase/isolation & purification , Phosphopyruvate Hydratase/metabolism , Plasminogen/metabolism , Streptococcus pneumoniae/enzymology , Amino Acid Sequence , Antibodies, Bacterial/blood , Bacteremia/immunology , Bacteremia/microbiology , Humans , In Vitro Techniques , Molecular Sequence Data , Molecular Weight , Phosphopyruvate Hydratase/genetics , Phosphopyruvate Hydratase/immunology , Pneumococcal Infections/immunology , Pneumococcal Infections/microbiology , Receptors, Cell Surface/metabolism , Receptors, Urokinase Plasminogen Activator , Streptococcus pneumoniae/genetics , Streptococcus pneumoniae/immunology , Streptococcus pneumoniae/metabolism
7.
Methods Mol Med ; 48: 77-84, 2001.
Article in English | MEDLINE | ID: mdl-21374407

ABSTRACT

Streptococcus pneumoniae is an important human pathogen causing a wide spectrum of disease including pneumonia, otitis media, bacteraemia, and meningitis. It is a significant cause of morbidity and mortality worldwide and now penicillin resistance is becoming an ever increasing problem (1-2). Initially, all S. pneumoniae isolates were exquisitely sensitive to penicillin and thus it was the drug of choice. However, the increase in resistance to penicillin seen in S. pneumoniae throughout the world has complicated treatment protocols. Penicillin resistance in S. pneumoniae also leads to some degree of cross resistance to other ß-lactams, including the third generation cephalosporins and the carbapenems.

9.
Am J Ther ; 6(1): 25-36, 1999 Jan.
Article in English | MEDLINE | ID: mdl-10423644

ABSTRACT

This article presents a meta-regression analysis of published studies of omeprazole plus antibiotics (amoxicillin, clarithromycin, or an imidazole derivative) in the treatment of Helicobacter pylori. Eligible studies were all randomized, controlled trials published through April 1996 with 10 or more patients receiving omeprazole plus antibiotics for 5 or more days and testing for H. pylori eradication 4 weeks or more after treatment. Probability of eradication was calculated for each treatment arm, and logistic regression was performed using study characteristics as covariates. Seventy-four studies involving 117 treatment arms with 4,769 patients were identified. The eradication rate was 76% for omeprazole plus clarithromycin and 65% for omeprazole plus amoxicillin dual regimens (P <.0001). Eradication rates for triple regimens were 82%, omeprazole plus amoxicillin plus clarithromycin; 83%, omeprazole plus amoxicillin plus imidazole; and 89%, omeprazole plus clarithromycin plus imidazole. In a multiple logistic regression analysis, significant factors were antibiotic, disease, omeprazole dose, and whether treatment was followed by maintenance omeprazole. A systematic overview of the best available evidence suggests that dual therapy with omeprazole plus clarithromycin is superior to omeprazole plus amoxicillin. Triple therapy is better than dual therapy. Treatment works better on ulcers than on nonulcer dyspepsia. Higher doses of omeprazole give better results. Additional trials exploring higher omeprazole doses for varying durations as well as cost, side effects, and compliance trade-offs with efficacy are recommended.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Anti-Ulcer Agents/therapeutic use , Helicobacter Infections/drug therapy , Omeprazole/therapeutic use , Data Collection , Drug Therapy, Combination , Humans , Randomized Controlled Trials as Topic , Regression Analysis , Time Factors
10.
Hypertension ; 33(1): 24-31, 1999 Jan.
Article in English | MEDLINE | ID: mdl-9931077

ABSTRACT

-Our objective was to compare cardiovascular event rates in patients with stable angina receiving nifedipine as monotherapy or combination therapy and in active drug controls. A MEDLARS search of published articles from 1966 to 1995 in English, French, German, Italian, or Spanish, supplemented by a manual search of bibliographies, identified 60 randomized controlled trials that met protocol criteria. Blinded articles were extracted by 2 physicians. The pooled risks of death, withdrawal, and cardiovascular event were computed and expressed as odds ratios (ORs) for all nifedipine formulations and relative to same study control drug regimens. Thirty cardiovascular events were reported in 2635 nifedipine exposures (1.14%) and 19 events in 2655 other active drug exposures (0.72%). Unadjusted ORs for nifedipine versus controls were 1.40 (95% CI, 0.56 to 3.49) for major events (death, nonfatal myocardial infarction, stroke, revascularization procedure), 1.75 (95% CI, 0.83 to 3.67) for increased angina, and 1.61 (95% CI, 0.91 to 2.87) for all events (major events plus increased angina). Episodes of increased angina were more frequent on immediate-release nifedipine (OR, 4.19 [95% CI, 1.41 to 12.49]) and on nifedipine monotherapy (OR, 2.61 [95% CI, 1.30 to 5.26]). The OR for immediate-release nifedipine was significantly higher than that for sustained-release/extended-release nifedipine (P=0.001), and the OR for nifedipine monotherapy was higher than that for nifedipine combination therapy (P=0.03). Increased risks of cardiovascular events in patients with stable angina on nifedipine were due primarily to more episodes of increased angina, confined to the immediate-release formulation and to nifedipine monotherapy.


Subject(s)
Angina Pectoris/drug therapy , Calcium Channel Blockers/therapeutic use , Nifedipine/therapeutic use , Vasodilator Agents/therapeutic use , Adrenergic beta-Antagonists/administration & dosage , Angina Pectoris/complications , Angina Pectoris/mortality , Calcium Channel Blockers/adverse effects , Delayed-Action Preparations , Dosage Forms , Drug Therapy, Combination , Female , Humans , Male , Middle Aged , Nifedipine/administration & dosage , Nifedipine/adverse effects , Nitrates/administration & dosage , Odds Ratio , Placebos , Prospective Studies , Randomized Controlled Trials as Topic , Risk Factors , Safety , Time Factors , Vasodilator Agents/adverse effects
11.
J Clin Microbiol ; 37(1): 157-60, 1999 Jan.
Article in English | MEDLINE | ID: mdl-9854082

ABSTRACT

A PCR-restriction fragment length polymorphism strategy directed against the pbp2b gene was evaluated for identification of penicillin susceptibility. A total of 106 United Kingdom (U.K.), 30 Danish, and 11 Papua New Guinean strains were tested. Of the U.K. strains, all the susceptible and all but one of the resistant isolates were correctly assigned. By using conventional definitions of "not resistant" and "not susceptible," the sensitivities were 97. 5 and 94.4%, the specificities were 100 and 98.9%, the positive predictive values were 100 and 94.4%, and the negative predictive values were 93.1 and 98.9%, respectively. This technique may allow susceptible (MIC, <0.1 mg/liter) and resistant (MIC, >1 mg/liter) isolates to be distinguished in a single PCR.


Subject(s)
Aminoacyltransferases , Bacterial Proteins , Carrier Proteins/genetics , Hexosyltransferases , Microbial Sensitivity Tests , Muramoylpentapeptide Carboxypeptidase/genetics , Penicillin Resistance/genetics , Peptidyl Transferases , Streptococcus pneumoniae/drug effects , Bacteriological Techniques , DNA, Bacterial/analysis , DNA, Bacterial/genetics , Humans , Penicillin-Binding Proteins , Penicillins/pharmacology , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length , Streptococcus pneumoniae/genetics , Streptococcus pneumoniae/isolation & purification
12.
Pharmacotherapy ; 18(6): 1290-7, 1998.
Article in English | MEDLINE | ID: mdl-9855329

ABSTRACT

We performed a literature search for all clinical studies reporting outcomes in patients with the acquired immunodeficiency syndrome (AIDS) receiving granulocyte-macrophage colony-stimulating factor (GM-CSF) for any indication. Safety outcomes included human immunodeficiency virus replication, immune status, and frequency of opportunistic infections and neoplasms. Data were synthesized qualitatively. We identified 22 studies (274 patients): 12 addressed AIDS neutropenia, 8 AIDS cancer therapy, and 2 opportunistic infections. Viral burden was assessed by serum p24Ag in 15 studies. Nine reported no change in levels, three net decreases, and three net increases. All studies showing net increases involved patients receiving GM-CSF without a concurrent antiretroviral. The CD4 counts were unchanged in 5 studies, increased in 3, and not reported in 14. The incidence of neoplasms or new opportunistic infections was low. The literature suggests no increased risk of viral replication or clinical deterioration in patients with AIDS who take GM-CSF concurrently with zidovudine.


Subject(s)
Acquired Immunodeficiency Syndrome/drug therapy , Granulocyte-Macrophage Colony-Stimulating Factor/therapeutic use , Acquired Immunodeficiency Syndrome/virology , Clinical Trials as Topic , HIV/drug effects , Humans , Treatment Outcome
13.
Infect Immun ; 65(9): 3936-8, 1997 Sep.
Article in English | MEDLINE | ID: mdl-9284174

ABSTRACT

The lytA gene encoding the autolysin of Streptococcus pneumoniae may be a virulence determinant. Single-strand conformational polymorphism analysis demonstrated heterogenicity throughout the gene in clinical isolates and strains from the clonal serotypes 7 and 14. Sequence analysis of part of the choline-binding domain showed that in two isolates four amino acid substitutions occurred.


Subject(s)
N-Acetylmuramoyl-L-alanine Amidase/genetics , Streptococcus pneumoniae/genetics , Alleles , Genetic Variation , Polymorphism, Single-Stranded Conformational
14.
Hypertension ; 30(1 Pt 1): 7-14, 1997 Jul.
Article in English | MEDLINE | ID: mdl-9231814

ABSTRACT

Our objective was to compare cardiovascular event rates in patients with mild or moderate hypertension who received nifedipine with active drug controls. We performed a MEDLARS search using the MeSH heading "hypertension" and the text word "nifedipine" to identify all articles that were published between 1966 and August 1995 in English, French, German, Italian, and Spanish languages and that involved human subjects. The computerized search was supplemented by a manual search of article bibliographies. Review of 1880 citations revealed 98 randomized controlled clinical trials that met protocol criteria. Articles were extracted independently by two doctors who were blinded for author, institution, and treatment regimen, using a structured, pretested extraction form. Differences of opinion were resolved by consensus. Fourteen events occurred in 5198 exposures (0.27%) to nifedipine and 24 events in 5402 exposures (0.44%) to other active drug controls. Unadjusted odds ratios for nifedipine versus controls were 0.49 (95% confidence interval [CI], 0.22-1.09) for definitive events (death, nonfatal myocardial infarction or stroke, revascularization procedure) and 0.61 (95% CI, 0.31-1.17) for all events (definitive plus increased angina). The odds ratio for nifedipine monotherapy (sustained- or extended-release in 91% of exposures) was nonsignificantly higher for definitive and all events (odds ratio, 1.40; 95% CI, 0.49-4.03 and odds ratio, 1.39; 95% CI, 0.59-3.32, respectively). The odds ratio for nifedipine in combination with another drug was significantly lower for definitive and all events (odds ratio, 0.09; 95% CI, 0.01-0.66 and odds ratio, 0.15; 95% CI, 0.03-0.65, respectively). Differences in odds ratio for nifedipine monotherapy and combined therapy were statistically significant (P=.02 for definitive events and P=.001 for all events). Results support the safety of sustained- and extended-release nifedipine in the treatment of mild or moderate hypertension when it is used in combination with other drugs.


Subject(s)
Calcium Channel Blockers/therapeutic use , Hypertension/drug therapy , Nifedipine/therapeutic use , Vasodilator Agents/therapeutic use , Adrenergic beta-Antagonists/administration & dosage , Adult , Aged , Calcium Channel Blockers/administration & dosage , Cross-Over Studies , Diuretics/administration & dosage , Drug Therapy, Combination , Humans , MEDLARS , Middle Aged , Nifedipine/administration & dosage , Odds Ratio , Safety , Time Factors , United States , Vasodilator Agents/administration & dosage
15.
Urology ; 49(1): 71-8, 1997 Jan.
Article in English | MEDLINE | ID: mdl-9000189

ABSTRACT

OBJECTIVES: To assess the survival benefit of maximum androgen blockade (MAB) using nonsteroidal antiandrogens (NSAAs) through meta-analysis of published randomized controlled trials (RCTs). METHODS: All RCTs comparing treatment with NSAA plus either luteinizing hormone-releasing hormone (LHRH) or orchiectomy versus treatment with LHRH or orchiectomy alone were included if the necessary statistical summaries were present in the publication. Estimates and standard errors of log hazard ratio for overall survival and progression-free survival were derived from published studies using two methods: (1) reconstructing an annual life table from graphical presentations of survival distributions and fitting discrete proportional hazard models, and (2) reconstructing the log hazard ratio from reported P values and numbers of deaths. An alternative set of log hazard ratios was derived from figures presented in a summary report by the Prostate Cancer Trialists' Collaborative Group (PCTCG). Comparative meta-analyses were performed using the random effects approach of DerSimonian and Laird. Additionally, published studies were used in a random-effects-based meta-analysis of objective tumor response. RESULTS: Nine studies provided enough information to perform a meta-analysis for survival using one of the two methods. Estimates of relative risks (RR) comparing treatment with NSAA plus either LHRH or orchiectomy versus treatment with LHRH or orchiectomy alone with respect to overall survival were 0.78 (95% confidence intervals [CIs] 0.67 to 0.90) using method 1, and 0.84 (95% CI 0.76 to 0.93) using method 2. Sensitivity analyses based on PCTCG data showed that a favorable survival result for MAB was associated with NSAAs but not with steroidal antiandrogens and depended on randomization blinding and overall trial quality. Additionally, random-effects-based meta-analysis of published studies showed a significant increase in time-to-progression (RR = 0.74; 95% CI 0.63 to 0.86) and an increase in objective tumor responses for MAB using NSAAs compared with castration alone (odds ratio = 0.65; 95% CI 0.51 to 0.81; P = 0.00022). CONCLUSIONS: Inconsistent results have been published about the benefit of MAB in advanced prostate cancer. This meta-analysis supports a beneficial effect for MAB using NSAAs compared with castration alone, and sensitivity analyses suggest that the design of future trials should carefully address issues of patient characterization, randomization blinding, and other study quality issues.


Subject(s)
Androgen Antagonists/therapeutic use , Prostatic Neoplasms/drug therapy , Disease-Free Survival , Humans , Male , Prostatic Neoplasms/mortality , Randomized Controlled Trials as Topic , Survival Rate
17.
FEMS Microbiol Lett ; 143(2-3): 279-84, 1996 10 01.
Article in English | MEDLINE | ID: mdl-8837483

ABSTRACT

In this study we have demonstrated the activity of a choline phosphate cytidylyltransferase in cell free extracts of Streptococcus pneumoniae. Southern blot analysis of restricted S. pneumoniae genomic DNA probed with the gene coding for the choline phosphate cytidylyltransferase of Saccharomyces cerevisiae demonstrated that there is homology between the S. cerevisiae cct gene and genomic DNA of S. pneumoniae. We believe that this enzyme is involved in the biosynthesis of the choline containing cell wall antigens, teichoic acid and lipoteichoic acid, catalysing the activation of choline phosphate to CDP-choline which is then incorporated into the polysaccharide moiety.


Subject(s)
Nucleotidyltransferases/metabolism , Phosphorylcholine/metabolism , Streptococcus pneumoniae/metabolism , Animals , Antigens, Bacterial/biosynthesis , Antigens, Bacterial/chemistry , Base Sequence , Carbohydrate Sequence , Choline-Phosphate Cytidylyltransferase , Conserved Sequence , DNA Primers/genetics , Lipopolysaccharides/biosynthesis , Lipopolysaccharides/chemistry , Lipopolysaccharides/immunology , Molecular Sequence Data , Nucleotidyltransferases/genetics , Rats , Saccharomyces cerevisiae/enzymology , Saccharomyces cerevisiae/genetics , Streptococcus pneumoniae/genetics , Streptococcus pneumoniae/immunology , Teichoic Acids/biosynthesis , Teichoic Acids/chemistry , Teichoic Acids/immunology
18.
J Hypertens Suppl ; 14(2): S5-7, 1996 Sep.
Article in English | MEDLINE | ID: mdl-8934371

ABSTRACT

UNLABELLED: META-ANALYSIS: A meta-analysis of published randomized control trials of nifedipine in hypertension and stable angina pectoris was performed. RESULTS: The results suggest a formulation-dependent increased risk of mortality and adverse cardiovascular outcomes for monotherapy use in patients with stable angina pectoris. No increased risk was seen in the hypertension studies.


Subject(s)
Hypertension/drug therapy , Myocardial Ischemia/drug therapy , Nifedipine/therapeutic use , Randomized Controlled Trials as Topic , Vasodilator Agents/therapeutic use , Humans , Hypertension/mortality , Hypertension/physiopathology , Myocardial Ischemia/mortality , Myocardial Ischemia/physiopathology
19.
FEMS Microbiol Lett ; 138(2-3): 141-5, 1996 May 01.
Article in English | MEDLINE | ID: mdl-9026440

ABSTRACT

The choline-containing teichoic and lipoteichoic acids play an important part in cell wall metabolism of Streptococcus pneumoniae. We propose that a choline kinase enzyme has a role in the synthesis of these antigens. The presence of this enzyme was demonstrated in cell free extracts of S. pneumoniae by measuring the fall in ATP concentration due to phosphorylation of choline. Genomic DNA of S. pneumoniae hybridised with a probe consisting of an internal fragment of the choline kinase gene of Saccharomyces cerevisiae and one consisting of the choline binding domain of lytA.


Subject(s)
Antigens, Bacterial/metabolism , Choline Kinase/metabolism , Choline/metabolism , Streptococcus pneumoniae/immunology , Streptococcus pneumoniae/metabolism , Base Sequence , Cell Wall/immunology , Cell Wall/metabolism , Choline Kinase/genetics , DNA Primers/genetics , DNA, Bacterial/genetics , Genes, Bacterial , Genes, Fungal , Lipopolysaccharides/biosynthesis , Lipopolysaccharides/immunology , Molecular Sequence Data , Saccharomyces cerevisiae/enzymology , Saccharomyces cerevisiae/genetics , Streptococcus pneumoniae/genetics , Teichoic Acids/biosynthesis , Teichoic Acids/immunology
20.
Microbiology (Reading) ; 141 ( Pt 11): 2929-36, 1995 Nov.
Article in English | MEDLINE | ID: mdl-8535521

ABSTRACT

Streptococcus mutans is able to synthesize extracellular glucans from sucrose which contribute to adherence of these bacteria. Extracellular dextranase can partially degrade the glucans, and may therefore affect virulence of S. mutans. In order to isolate mutants unable to produce dextranase, a DNA library was constructed by inserting random Sau3AI-digested fragments of chromosomal DNA from S. mutans into the BamHI site of the streptococcal integration vector pVA891, which is able to replicate in Escherichia coli but does not possess a streptococcal origin of replication. The resultant plasmids were introduced into S. mutans LT11, allowing insertional inactivation through homologous recombination. Two transformants were identified which did not possess dextranase activity. Integration of a single copy of the plasmid into the chromosome of these transformants was confirmed by Southern hybridization analysis. Chromosomal DNA fragments flanking the plasmid were recovered using a marker rescue technique, and sequenced. Comparison with known sequences using the BLASTX program showed 56% homology at the amino acid level between the sequenced gene fragment and dextranase from Streptococcus sobrinus, strongly suggesting that the S. mutans dextranase gene (dexA) had been inactivated. The colony morphology of the dextranase mutants when grown on Todd-Hewitt agar containing sucrose was altered compared to the parent strain, with an apparent build-up of extracellular polymer. The mutants were also more adherent to a smooth surface than LT11 but there was no apparent difference in sucrose-dependent cell-cell aggregation.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Dextranase/genetics , Genes, Bacterial , Streptococcus mutans/enzymology , Streptococcus mutans/genetics , Amino Acid Sequence , Bacterial Adhesion/genetics , Base Sequence , DNA Primers/genetics , DNA, Bacterial/genetics , Dextranase/chemistry , Dextrans/metabolism , Molecular Sequence Data , Molecular Weight , Mutagenesis , Streptococcus mutans/metabolism
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