Biomedical subjects

P Newsome

Publications and source records attributed to P Newsome.

5 recordsLinked to original sources

PubMed2004

The aetiology and treatment of oral halitosis: an update.

Halitosis refers to the condition of offensive mouth odour. More than 90% of cases of halitosis originate from the oral cavity. The implicated bacteria (Fusobacterium nucleatum, Prevotella intermedia, and Tannerella forsythensis) are located in stagnant areas in the oral cavity, such as the dorsal surface of tongue, periodontal pockets, and interproximal areas. These bacteria proteolyse the amino acids releasing volatile sulphur compounds. The management of halitosis involves determining and eliminating the causes, which includes identifying any contributory factors, because certain medical conditions are also associated with characteristic smells. Professional advice should be given on oral hygiene and diet, and treatments should include dental scaling, and root planing of the associated periodontal pockets to reduce the bacterial loading. In addition to the normal oral hygiene practice, tongue cleaning and use of mouthwash are advocated. This paper discusses the common aetiological factors, classification of oral halitosis, and its treatment.

Bacteroidaceae Infections↗

PubMed2003

Effects of acute liver injury on blood coagulation.

The mechanisms leading to the hemostatic changes of acute liver injury are poorly understood. To study these further we have assessed coagulation and immune changes in patients with acute paracetamol overdose and compared the results to patients with chronic cirrhosis and normal healthy controls. The results demonstrate that in paracetamol overdose coagulation factors (F)II, V, VII and X were reduced to a similar degree and were significantly lower than FIX and FXI (mean levels 0.28, 0.16, 0.13, 0.19, 0.51 and 0.72 IU mL(-1), respectively). In cirrhosis, by contrast, FII, FV, FVII, FIX and FX were equally reduced whilst FXI was lower than the other factors (mean levels 0.64, 0.69, 0.62, 0.60, 0.66 and 0.40 IU mL-1, respectively). FVIII was raised in paracetamol overdose patients but normal in those with cirrhosis (mean levels 1.95 and 1.01 IU mL(-1), respectively). Interleukin-6 and tumor necrosis factor-alpha levels were raised in both patient groups, but higher levels were found in paracetamol overdose, compared to cirrhosis. Thrombin-antithrombin and soluble tissue factor levels were higher in those with acute liver injury but normal in cirrhosis. Antithrombin levels were reduced in both acute liver injury and cirrhosis. From these data we put forward a novel mechanism for the coagulation changes in acute paracetamol induced liver injury. We propose that immune activation leads to tissue factor-initiated consumption of FII, FV, FVII and FX, but that levels of FIX and FXI are better preserved because antithrombin inhibits the thrombin induced positive feedback loop that activates these latter factors.

Acetaminophen↗

PubMed1996

Bacteremia in a pediatric hemodialysis unit secondary to Enterococcus fecalis.

UNLABELLED: Bacteremia is often a serious and recurring problem in children with hemodialysis catheters. We report an outbreak of Enterococcus bacteremia in a pediatric hemodialysis unit occurring from June 1992 to June 1993. During this period, 18 episodes of bacteremia occurred in eight children; 11 infections were polymicrobial. Enterococcus fecalis was associated with 13 infections in five patients (8 polymicrobial). Other pathogens included Enterobacter cloacae (5 infections), Staphylococcus (3), Staphylococcus epidermidis (2), and Klebsiella pneumoniae (2). All Enterococcus infections occurred in patients with dual-lumen subclavian venous catheters. Skin and catheter sites were culture negative, except in one patient. Rectal swabs were positive for Enterococcus in five patients. Enterococcus was not isolated from any source within the unit. Serotypes of all Enterococcus isolates were different, except for 2 isolates in the same patient. Starting in June 1993, catheters were flushed after dialysis with vancomycin or ampicillin. Since initiating this procedure, further episodes of Enterococcus bacteremia have not occurred. A questionnaire sent to other pediatric hemodialysis units failed to identify Enterococcus among 26 cases of bacteremia. IN CONCLUSION: (1) Enterococcus is an unusual pathogen for hemodialysis-related bacteremia in children; (2) patients with dialysis catheters were predisposed to this infection; (3) a common source for Enterococcus could not be identified by either culture or by serotyping; (4) flushing catheters with antibiotics after dialysis was effective prevention.

Bacteremia↗

PubMed1995

The orthogonal orientation shift and spatial filtering.

A line abutting two tilted flanks is apparently shifted towards the orientation orthogonal to the flanks and at the same time is reduced in its apparent length. It has been suggested that both effects are caused by band-pass spatial filtering, followed by location of the end points of the line at the peaks in the filtered image. Here implications of the filtering explanation of these effects are explored further. In the first experiment, it was predicted that orientation thresholds (as opposed to biases) would be increased for short line lengths, and would be further increased by abutting bars. The predictions were confirmed. It was shown in experiment 2 that the orientation shift was reduced by a small (4 min arc) gap between target lines and orthogonal flanks. In experiment 3 the threshold elevations and the orientation shift produced by orthogonal and tilted flanks were compared. Last, in experiment 4, the threshold elevations and orientation shift produced by orthogonal and tilted flanks, at different retinal eccentricities varying from 0 to 3.2 deg were compared, and the prediction that the magnitude of the orientation shift would decrease with line length and increase with eccentricity was confirmed. The connection is explored between the orientation shift and the Zöllner illusion, and demonstrations are presented of the Zöllner effect in which target and inducing lines are of opposite contrast on a gray background. It is concluded that the Judd and Zöllner illusions do not depend upon a single mechanism.

Differential Threshold↗

PubMed1986

Large scale, rapid purification of recombinant tissue-type plasminogen activator.

Recombinant tissue-type plasminogen activator (rt-PA) from cultures of a genetically manipulated Bowes melanoma cell line (TRBM6) was purified in batches of average volume 451 using an autoclavable, reusable, continuous chromatography system comprising zinc chelate-Sepharose CL4B and lysine-Sepharose CL4B. After eight successive purifications the rt-PA was ultrafiltered to yield a preparation containing 4.9 mg protein/ml and 2.7 X 10(6) IU/ml. Analysis by SDS-polyacrylamide gel electrophoresis followed by staining with Coomassie brilliant blue R250 showed major protein bands at Mr = 63,000 and 65,000; most of the material was in the 1-chain form. The potential usefulness of a simple, rapid continuous chromatography system that can be operated under aseptic conditions is discussed.

Animals↗