Recombinant human erythropoietin for chronic renal failure anaemia in pre-dialysis patients

BACKGROUND

Treatment with recombinant human erythropoietin (rHu EPO) in dialysis patients has been shown to be highly effective in terms of correcting anaemia and improving quality of life. There is debate concerning the benefits of rHu EPO use in pre-dialysis patients. There is a concern that rHu EPO may accelerate the deterioration in renal function, however the opposing view is that if rHu EPO is as effective in pre-dialysis patients that by improving the patients sense of well-being the onset of dialysis could be delayed.

OBJECTIVES

To assess the effects of rHu EPO use in pre-dialysis patients with renal anaemia.

SEARCH STRATEGY

We searched MEDLINE (1980 to May Week 3 2001), EMBASE (1984 to Week 24 2001), BIOSIS (1985 to January 1997), CINAHL (1982 to October 1997), The Cochrane Library (Issue 1, 1997), CHEMABS (1984 to November 1996), SIGLE (1980 to June 1996), CRIB (10th edition, 1995), UK NRR (14TH consolidation, September 1996), RSC ( 1980 to February 1997), HealthSTAR (1995 to October 1997), IBSS (1984 to July 1997), NEED (July 1997) and reference lists of relevant articles. We contacted biomedical companies and investigators in the field and we hand searched Kidney International (including all supplements but excluding all conference proceedings except for 1994) July 1983 to May 1997 inclusive. The internet was also searched on: August 1997. We had also identified some studies from a previous broad search for all randomised controlled trials (RCTs) relevant to the management of end-stage renal disease. Date of the most recent search: June 2001.

SELECTION CRITERIA

RCTs or quasi-RCTs comparing the use of rHu EPO with no rHu EPO or placebo in pre-dialysis patients.

DATA COLLECTION AND ANALYSIS

Only published data were used. Data were abstracted by a single investigator onto a standard form. A sample of the data abstracted was double-checked by another reviewer. The data abstracted were relevant to the predetermined outcome measures. Some authors were contacted to clarify how patients were allocated to groups. All authors from included studies were contacted for missing information.

MAIN RESULTS

Twelve studies with a total of 232 participants met the inclusion criteria and where possible data from these were summated by meta-analyses (Peto's Odds Ratio (OR) and Weighted Mean Difference (WMD)). The majority of the trials included small numbers and were of short duration (8-10 weeks) with the exception of three trials. There was a marked improvement in haemoglobin (mean difference 2.3g/dL, 95% CI 1.37 to 3.23) and haematocrit (WMD 9.92%, 95% CI 8.78 to 11.05) with the treatment and a decrease in the number of patients requiring blood transfusion (OR 0.25, 95% CI 0.09 to 0.69). The data from all studies which reported quality of life or exercise capacity demonstrated an improvement in the rHu EPO group. None of the measures of progression of renal disease (when a summary statistic was calculated) demonstrated a statistically significant difference. Though the requirement for antihypertensive treatment appears to be increased by rHu EPO (OR 1.84, 95% CI 1.02 to 3.32), there was no other statistically significant increase in adverse events. Based on the limited current evidence, decisions therefore have to be made on whether the putative benefits in terms of quality of life identified in the review are worth the extra costs of pre-dialysis rHu EPO.

REVIEWER'S CONCLUSIONS

This review has shown that treatment with rHu EPO in pre-dialysis patients corrects anaemia and avoids the requirement for blood transfusions. There are also improvements in quality of life and exercise capacity. There may be increased hypertension. Most of the trials were not of sufficient duration to assess the effects of rHu EPO on progression of renal disease. In the long term, questions still remain about whether pre-dialysis rHu EPO either speeds up or delays the onset of dialysis. Thus there is insufficient evidence on the total costs and benefits of treating pre-dialysis patients with rHu EPO.

Evidence-based medicine in nephrology: identifying and critically appraising the literature

BACKGROUND

Uncertainties about best management of end-stage renal disease (ESRD) are reflected in wide variations in practice. Systematic reviews aim to reduce uncertainty by strengthening the evidence base for clinical practice, allowing estimation of the benefits and risks of particular interventions, whilst minimizing the potential for bias. This paper describes the methods and conduct of six systematic reviews of aspects of the management of ESRD, and the yield in terms of trials found.

METHODS

Our methodology was based on that recommended by the Cochrane Collaboration (an international initiative set up to perform and disseminate systematic reviews of health care). It involved a systematic search of electronic databases and bibliographic reference lists, together with handsearching of Kidney International for studies relevant to the management of ESRD, followed by a systematic assessment of study quality.

RESULTS

Around 12,000 abstracts were assessed which had been identified from electronic sources. Of these, 2085 (18%) were deemed to be reports of possible randomized or quasi-randomized controlled trials relevant to the management of ESRD. Three hundred and forty were relevant to the six specific reviews, and after assessment of the full manuscripts, 39 studies were finally included in our reviews. Reports of a further nine trials, which were identified from other sources, were also included. The broad search adopted allowed the parallel development of a register of trials of all aspects of the management of ESRD.

CONCLUSIONS

This study has demonstrated that the methodology of systematic reviews, as promoted by the Cochrane Renal Group, is feasible but has significant resource implications. The development of a register of randomized controlled trials (RCTs) related to the management of ESRD will facilitate this form of research in the future.

Evaluation of clinical guidelines for the management of end-stage renal disease in europe: the EU BIOMED 1 study

BACKGROUND

There are wide national and international variations in the management of patients with end-stage renal disease (ESRD). The aim of this study was to develop, harmonize, implement, and evaluate consensus-based clinical guidelines for the management of renal anaemia and renal bone disease in patients with ESRD, and for the prevention and management of cytomegalovirus disease in renal transplant recipients across six renal centres in Europe.

METHODS

The trial was a prospective, multicentre, randomized balanced incomplete block design. Nephrologists from the six European renal units were randomized to develop and implement guidelines for two out of the three conditions and to act as a control for the third condition. Data were collected pre- (1 year) and post- (9 months) intervention on aspects of patient monitoring, management, and outcome.

RESULTS

Eight hundred and twenty-nine dialysis patients from the six European dialysis centres were included in the study. Multivariate analysis (adjusting for case-mix and secular trends) showed a significant increase in the number of monitoring events in the guideline group compared with control group (6%, 95% CI, 1-11%). There was no concomitant increase in either appropriate management or the number of favourable patient outcomes.

CONCLUSIONS

In the first European collaboration on renal guidelines, the introduction of the guidelines improved the monitoring of the patients, but did not improve patient management or outcome. This study suggests the potential for creating clinical guidelines with the aim of standardizing treatment protocols across international boundaries, and improving the quality of the medical care provided.

Mutagenesis reveals a role for ABP/GRIP binding to GluR2 in synaptic surface accumulation of the AMPA receptor

We studied the role of PDZ proteins GRIP, ABP, and PICK1 in GluR2 AMPA receptor trafficking. An epitope-tagged MycGluR2 subunit, when expressed in hippocampal cultured neurons, was specifically targeted to the synaptic surface. With the mutant MycGluR2delta1-10, which lacks the PDZ binding site, the overall dendritic intracellular transport and the synaptic surface targeting were not affected. However, over time, Myc-GluR2delta1-10 accumulated at synapses significantly less than MycGluR2. Notably, a single residue substitution, S880A, which blocks binding to ABP/GRIP but not to PICK1, reduced synaptic accumulation to the same extent as the PDZ site truncation. We conclude that the association of GluR2 with ABP and/or GRIP but not PICK1 is essential for maintaining the synaptic surface accumulation of the receptor, possibly by limiting its endocytotic rate.

Evidence-based medicine and health economics: a case study of end stage renal disease

This paper explores the potential for use of an economic evaluation framework alongside systematic reviews. Clinical issues in dialysis therapy for end stage renal disease are used as case studies. The effectiveness data required were obtained from a systematic review of randomized controlled trials. Resource use and cost data were obtained from three sources; the identified randomized controlled trials, a separate review of observational studies and primary data collection. The results of the case studies show that, although simple economic evaluations were possible, issues arose, such as how transferable results are between settings and how appropriate it is to focus on the average patient. The interface between economic evaluation and systematic reviews needs to be further developed in order to ensure that the best available evidence can be used to inform future policy and research.

Synaptophysin regulates clathrin-independent endocytosis of synaptic vesicles

The GTPase dynamin I is required for synaptic vesicle (SV) endocytosis. Our observation that dynamin binds to the SV protein synaptophysin in a Ca(2+)-dependent fashion suggested the possibility that a dynamin/synaptophysin complex functions in SV recycling. In this paper we show that disruption of the dynamin/synaptophysin interaction by peptide injection into the squid giant synapse preterminal results in a decrease in transmitter release during high-frequency stimulation, indicating an inhibition of SV recycling. Electron microscopy of these synapses reveals a depletion of SVs, demonstrating a block of vesicle retrieval after fusion. In addition, we observed an increase in clathrin-coated vesicles, indicating that the peptide does not block clathrin-dependent endocytosis. We conclude that the dynamin/synaptophysin complex functions in a clathrin-independent mechanism of SV endocytosis that is required for efficient synaptic transmission.

V-shaped cushion at the origin of bovine pulmonary supernumerary arteries: structure and putative function

This study investigates the anatomic structure at the origin of pulmonary supernumerary arteries and their parent conventional artery. Histological examination showed that at the origin of each supernumerary artery the wall of the parent conventional artery is organized into a distinct V-shaped structure, which begins on the hilum side of each supernumerary artery as a funnel-shaped channel running into the supernumerary artery. The base of the channel is particularly thin walled. The lateral walls of the channel are composed of musculoelastic cushions that become more pronounced toward the supernumerary artery and fuse on its distal side, forming a baffle that projects over the supernumerary artery lumen. These V-shaped structures/cushions were observed with video stereo dissecting microscopy in both an open and closed state in isolated arteries in vitro. Pulmonary vasoconstriction of isolated arteries with the thromboxane A(2) mimetic U-46619 increased the number of V-shaped structures in the closed state. These studies indicate the presence of a novel anatomic structure at the origin of pulmonary supernumerary arteries, which may be able to regulate blood flow into the supernumerary artery.

Probiotics: from myth to reality. Demonstration of functionality in animal models of disease and in human clinical trials

The enteric flora comprise approximately 95% of the total number of cells in the human body and are capable of eliciting immune responses while also protecting against microbial pathogens. However, the resident bacterial flora of the gastrointestinal tract (GIT) may also be implicated in the pathogenesis of several chronic conditions such as inflammatory bowel disease (IBD). The University College Cork-based Probiotic Research Group has successfully isolated and identified lactic acid bacteria (LAB) which exhibit beneficial probiotic traits. These characteristics include the demonstration of bile tolerance; acid resistance; adherence to host epithelial tissue; and in vitro antagonism of potentially-pathogenic micro-organisms or those which have been implicated in promoting inflammation. The primary objective of this report is to describe the strategy adopted for the selection of potentially effective probiotic bacteria. The study further describes the evaluation of two members of the resulting panel of micro-organisms (Lactobacillus salivarius subsp. salivarius UCC118 and Bifidobacterium longum infantis 35624) under in vitro conditions and throughout in vivo murine and human feeding trials. Specifically, an initial feeding study completed in Balb/c mice focused upon (i) effective delivery of the probiotic micro-organisms to the GIT and evaluation of the ability of the introduced strains to survive transit through, and possibly colonise, the murine GIT; (ii) accepting the complexity of the hostile GIT and faecal environments, development of a method of enumerating the introduced bacterial strains using conventional microbiological techniques; and (iii) assessment of the effects of administered bacterial strains on the numbers of specific recoverable indigenous bacteria in the murine GIT and faeces. Additional research, exploiting the availability of murine models of inflammatory bowel disease, demonstrated the beneficial effects of administering probiotic combinations of Lactobacillus salivarius UCC118 and Bifidobacterium longum infantis 35624 in prevention of illness-related weight loss. A further ethically-approved feeding trial, successfully conducted in 80 healthy volunteers, demonstrated that yoghurt can be used as a vehicle for delivery of Lactobacillus salivarius strain UCC118 to the human GIT with considerable efficacy in influencing gut flora and colonisation.

Altered expression of mRNAs for apoptosis-modulating proteins in a low level multidrug resistant variant of a human lung carcinoma cell line that also expresses mdr1 mRNA

An in vitro model that might be relevant to cancer cell chemoresistance in vivo was generated by exposing the human lung carcinoma clonal cell line DLKP-SQ to 10 sequential pulses of pharmacologically attainable doses of doxorubicin. The resistant variant, DLKP-SQ/10p, was found to be cross-resistant to doxorubicin (10x), vincristine (43x), etoposide (3x), sodium arsenate (3x), paclitaxel (38x) [which could imply overexpression of P-glycoprotein (P-gp) and possibly increased multidrug resistance-associated protein activity] and 5-fluorouracil (4x), but slightly sensitized to carboplatin. Analysis of mRNA levels in the resistant variant revealed overexpression of mdr1 mRNA without significant alteration in mrp, Topo. IIalpha, GSTpi, dhfr or thymidylate synthase mRNA levels. Overexpression of the anti-apoptotic bcl-xL transcript and the pro-apoptotic bax mRNA was also detected but no alterations in bcl-2 or bag-1 mRNA levels were observed. Resistance to a P-gp-associated drug, doxorubicin, could be reversed with P-gp circumventing agents such as cyclosporin A and verapamil, but these substances had no effect on resistance to 5-fluorouracil. Overexpression of the pro-apoptotic bcl-xS gene in the DLKP-SQ/10p line partially reversed resistance not only to P-gp-associated drugs but also to 5-fluorouracil, indicating that the ratio of bcl family members may be important in determining sensitivity to chemotherapeutic drug-induced apoptosis.

Altered expression of mRNAs for apoptosis-modulating proteins in a low level multidrug resistant variant of a human lung carcinoma cell line that also expresses mdr1 mRNA

An in vitro model that might be relevant to cancer cell chemoresistance in vivo was generated by exposing the human lung carcinoma clonal cell line DLKP-SQ to 10 sequential pulses of pharmacologically attainable doses of doxorubicin. The resistant variant, DLKP-SQ/10p, was found to be cross-resistant to doxorubicin (10x), vincristine (43x), etoposide (3x), sodium arsenate (3x), paclitaxel (38x) [which could imply overexpression of P-glycoprotein (P-gp) and possibly increased multidrug resistance-associated protein activity] and 5-fluorouracil (4x), but slightly sensitized to carboplatin. Analysis of mRNA levels in the resistant variant revealed overexpression of mdr1 mRNA without significant alteration in mrp, Topo. IIalpha, GSTpi, dhfr or thymidylate synthase mRNA levels. Overexpression of the anti-apoptotic bcl-xL transcript and the pro-apoptotic bax mRNA was also detected but no alterations in bcl-2 or bag-1 mRNA levels were observed. Resistance to a P-gp-associated drug, doxorubicin, could be reversed with P-gp circumventing agents such as cyclosporin A and verapamil, but these substances had no effect on resistance to 5-fluorouracil. Overexpression of the pro-apoptotic bcl-xS gene in the DLKP-SQ/10p line partially reversed resistance not only to P-gp-associated drugs but also to 5-fluorouracil, indicating that the ratio of bcl family members may be important in determining sensitivity to chemotherapeutic drug-induced apoptosis.

Probiotics: from myth to reality. Demonstration of functionality in animal models of disease and in human clinical trials

The enteric flora comprise approximately 95% of the total number of cells in the human body and are capable of eliciting immune responses while also protecting against microbial pathogens. However, the resident bacterial flora of the gastrointestinal tract (GIT) may also be implicated in the pathogenesis of several chronic conditions such as inflammatory bowel disease (IBD). The University College Cork-based Probiotic Research Group has successfully isolated and identified lactic acid bacteria (LAB) which exhibit beneficial probiotic traits. These characteristics include the demonstration of bile tolerance; acid resistance; adherence to host epithelial tissue; and in vitro antagonism of potentially-pathogenic micro-organisms or those which have been implicated in promoting inflammation. The primary objective of this report is to describe the strategy adopted for the selection of potentially effective probiotic bacteria. The study further describes the evaluation of two members of the resulting panel of micro-organisms (Lactobacillus salivarius subsp. salivarius UCC118 and Bifidobacterium longum infantis 35624) under in vitro conditions and throughout in vivo murine and human feeding trials. Specifically, an initial feeding study completed in Balb/c mice focused upon (i) effective delivery of the probiotic micro-organisms to the GIT and evaluation of the ability of the introduced strains to survive transit through, and possibly colonise, the murine GIT; (ii) accepting the complexity of the hostile GIT and faecal environments, development of a method of enumerating the introduced bacterial strains using conventional microbiological techniques; and (iii) assessment of the effects of administered bacterial strains on the numbers of specific recoverable indigenous bacteria in the murine GIT and faeces. Additional research, exploiting the availability of murine models of inflammatory bowel disease, demonstrated the beneficial effects of administering probiotic combinations of Lactobacillus salivarius UCC118 and Bifidobacterium longum infantis 35624 in prevention of illness-related weight loss. A further ethically-approved feeding trial, successfully conducted in 80 healthy volunteers, demonstrated that yoghurt can be used as a vehicle for delivery of Lactobacillus salivarius strain UCC118 to the human GIT with considerable efficacy in influencing gut flora and colonisation.

Identification of four phage resistance plasmids from Lactococcus lactis subsp. cremoris HO2

The bacteriophage-host sensitivity patterns of 16 strains of Lactococcus lactis originally isolated from a mixed strain Cheddar cheese starter culture were determined. Using phages obtained from cheese factory whey, four of the strains were found to be highly phage resistant. One of these isolates, Lactococcus lactis subsp. cremoris HO2, was studied in detail to determine the mechanisms responsible for the phage insensitivity phenotypes. Conjugal transfer of plasmid DNA from strain HO2 allowed a function to be assigned to four of its six plasmids. A 46-kb molecule, designated pCI646, was found to harbor the lactose utilization genes, while this and plasmids of 58 kb (pCI658), 42 kb (pCI642), and 4.5 kb (pCI605) were shown to be responsible for the phage resistance phenotypes observed against the small isometric-headed phage phi712 (936 phage species) and the prolate-headed phage phic2 (c2 species). pCI658 was found to mediate an adsorption-blocking mechanism and was also responsible for the fluffy pellet phenotype of cells containing the molecule. pCI642 and pCI605 were both shown to be required for the operation of a restriction-modification system.

Novel anchorage of GluR2/3 to the postsynaptic density by the AMPA receptor-binding protein ABP

We report the cloning of alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor-binding protein (ABP), a postsynaptic density (PSD) protein related to glutamate receptor-interacting protein (GRIP) with two sets of three PDZ domains, which binds the GluR2/3 AMPA receptor subunits. ABP exhibits widespread CNS expression and is found at the postsynaptic membrane. We show that the protein interactions of the ABP/GRIP family differ from the PSD-95 family, which binds N-methyl-D-aspartate (NMDA) receptors. ABP binds to the GluR2/3 C-terminal VKI-COOH motif via class II hydrophobic PDZ interactions, distinct from the class I PSD-95-NMDA receptor interaction. ABP and GRIP also form homo- and heteromultimers through PDZ-PDZ interactions but do not bind PSD-95. We suggest that the ABP/GRIP and PSD-95 families form distinct scaffolds that anchor, respectively, AMPA and NMDA receptors.

Immune responses of IL-5 transgenic mice to parasites and aeroallergens

Eosinophils have long been thought to be effectors of immunity to helminths but have also been implicated in the pathogenesis of asthma. Patterns of cytokine production in the host may influence the pathogenesis of these diseases by regulating the activities of eosinophils and other components of the immune response. Mice which constitutively over-express IL-5 have profound and life-long eosinophilia in a restricted number of tissues. Although eosinophils from IL-5 transgenics are functionally competent for a number of parameters considered to be important in inflammation, untreated animals are overtly normal and free of disease. In addition, the responses of these animals when exposed to aeroallergens and helminths present a number of apparent paradoxes. Eosinophil accumulation in tissues adjacent to major airways is rapid and extensive in transgenics exposed to the aeroallergen, but even after treatment with antigen over many months these mice show no evidence of respiratory distress or pathology. Helminth-infected IL-5 transgenics and their non-transgenic littermates develop similar inflammatory responses at mucosal sites and are comparable for a number of T cell and antibody responses, but they differ considerably in their ability to clear some parasite species. The life-cycle of Nippostrongylus brasiliensis is significantly inhibited in IL-5 transgenics, but that of Toxocara canis is not. Our results also suggest that eosinophilia and/or over-expression of IL-5 may actually impair host resistance to Schistosoma mansoni and Trichinella spiralis. The pathogenesis of diseases in which eosinophils are involved may therefore be more complex than previously thought.

Insertion element IS3-based PCR method for subtyping Escherichia coli O157:H7

An Escherichia coli O157:H7 subtyping method based on PCR amplification of variable DNA sequences between the repetitive element IS3 was developed. Template DNA was prepared by boiling cells in Chelex. Two separate IS3 PCR amplifications were performed for each isolate: one with a single primer (primer IS3A) and one with two primers (primers IS3A and IS3B). The IS3 PCR subtyping method was applied to 35 epidemiologically related and unrelated E. coli O157:H7 isolates that had been previously characterized by pulsed-field gel electrophoresis (PFGE). PFGE identified 25 different subtypes (difference of one or more bands). PCR with single primer IS3A and primer pair IS3A-IS3B identified 6 and 14 different subtypes, respectively. By combining the results of the two PCR amplifications, 15 different IS3 PCR subtypes were identified. While not as sensitive as PFGE, IS3 PCR subtyping grouped all outbreak-related isolates. IS3 PCR banding patterns were reproducible between amplifications and between subcultures. IS3 PCR could serve as a simple, rapid screening method for the identification of unrelated E. coli O157:H7 isolates.

The analgesic efficacy of ibuprofen in periodontal surgery: A multicentre study

The efficacy of a non-steroidal anti-inflammatory agent, ibuprofen, was evaluated in pain control following periodontal surgery. This type of agent acts peripherally by inhibiting the release of prostaglandins and minimizing the local inflammatory response. Thus there may be an advantage in pre-treatment administration of the drug so as to delay or even prevent postoperative pain. The study was multicentre, involving a Public Hospital Periodontal Unit, two specialist periodontal practices in Sydney, NSW, and two in Canberra, ACT. One hundred and twenty-seven patients who were to undergo periodontal surgery were randomly given either two 200 mg tablets of ibuprofen or two matching placebo tablets at least 30 minutes before administration of local anaesthesia. The procedure was double blind: neither the patient nor the clinician was aware of the tablet identity. Postoperatively, all patients were given labelled ibuprofen for pain relief, but were randomly divided into two groups: As directed who were instructed to take the drug regularly for two days postoperatively, and As required, who were to take the drug only if needed for pain relief. All patients completed a diary recording quantity and time of medication, and regular assessment of pain experience utilizing a visual analogue scale. The As directed group showed no significant difference in pain experience between pre-operative and post-operative only medication, but the As required group experienced significantly less pain and requirement for medication if the ibuprofen was administered pre-operatively.

Post-transcriptional regulation of synaptic vesicle protein expression and the developmental control of synaptic vesicle formation

The regulated expression of synaptic vesicle (SV) proteins during development and the assembly of these proteins into functional SVs are critical aspects of nervous system maturation. We have examined the expression patterns of four SV proteins in embryonic hippocampal neurons developing in culture and have found that increases in the levels of these proteins result primarily from post-transcriptional regulation. Synaptotagmin I, vamp 2, and synapsin I proteins are synthesized at nearly constant rates as the neurons develop. However, these proteins are relatively unstable at early times in culture and undergo a progressive increase in half-life with time, possibly as a result of an increase in the efficiency with which they are incorporated into SVs. In contrast, synaptophysin is synthesized at a very low rate at early times in culture, and its rate of synthesis increases dramatically with time. The increase in synaptophysin synthesis is not simply the result of an increase in mRNA level, but is largely attributable to an increase in the rate of translational initiation. Despite the nearly constant rates of synthesis of synaptotagmin I, vamp 2, and synapsin I, we show that the number of SVs in these developing neurons increases, and that SV proteins are more efficiently targeted to SVs at later times in culture. Our results suggest that SV production during development is not limited by the rates of transcription of genes encoding the component proteins, thus allowing control of this process by cytoplasmic mechanisms, without signaling to the nucleus.

Bacteraemia caused by periodontal probing

Bacteraemia of oral origin may result in infective endocarditis in susceptible individuals. The aim of this pilot study was to investigate the occurrence of bacteraemia due to periodontal probing. Thirty patients (15 male, 15 female; mean age 42.7 years) with untreated periodontitis were investigated. All were free of significant medical disorders and none had taken antibiotics in the previous month. Prior to and immediately following periodontal probing, 20 mL of venous blood were obtained from each patient and inoculated into aerobic and anaerobic blood culture bottles and incubated. Negative bottles were monitored continuously for three weeks before being discarded. Periodontal probing consisted of measuring pockets at six points around each tooth and recording the presence or absence of bleeding. A positive bacteraemia was recorded for three of the patients prior to probing. One patient exhibited Prevotella species whilst two exhibited skin commensals. Following probing, 13 patients (43 per cent) exhibited bacteraemia of oral origin. Viridans streptococci were the most common isolates (45 per cent). No significant correlations were found between bacteraemia and the severity of periodontitis or extent of bleeding on probing. The results indicate that periodontal probing can cause bacteraemia in patients with periodontitis. It would be advisable for patients considered at risk of developing infective endocarditis to receive antibiotic prophylaxis for periodontal probing if they have radiographic evidence of periodontitis.

Biotechnology of lactic acid bacteria with special reference to bacteriophage resistance

Lactic acid bacteria play an important role in many food and feed fermentations. In recent years major advances have been made in unravelling the genetic and molecular basis of significant industrial traits of lactic acid bacteria. Bacteriophages which can infect and destroy lactic acid bacteria pose a particularly serious threat to dairy fermentations that can result in serious economic losses. Consequently, these organisms and the mechanisms by which they interact with their hosts have received much research attention. This paper reviews some of the key discoveries over the years that have led us to our current understanding of bacteriophages themselves and the means by which their disruptive influence may be minimized.