Garlic (Allium sativum) as an anti-Candida agent: a comparison of the efficacy of fresh garlic and freeze-dried extracts

AIMS

To determine the effects of fresh and freeze-dried extracts of Allium sativum on the physiology and morphology of Candida albicans.

METHODS AND RESULTS

Inhibition of growth in glucose-yeast extract-peptone was measured using a multiwell plate reader. Scanning and transmission electron microscopy investigations indicated loss of structural integrity. Gas chromatography-mass spectrometry of extracts was employed to separate and quantify putative inhibitory sulphur-containing components.

CONCLUSIONS

Fresh garlic extract has a greater efficacy than garlic powder extract as indicated both by its effects on morphology and inhibition of growth.

SIGNIFICANCE AND IMPACT OF THE STUDY

The ubiquitous opportunistic pathogen C. albicans is sensitive to garlic; resistance to the broad spectrum of active principles present is unlikely so that its anticandidal effects may provide an important alternative route to chemotherapy.

Nitrite inhibits hydrogen production and kills the cattle parasite Tritrichomonas foetus

AIMS

To investigate the effects of NaNO2 on the microaerophilic flagellated protozoan, Tritrichomonas foetus KV1, an economically important cattle parasite that inhabits the vagina and can spread rapidly through herds of animals by sexual transmission and leads to abortion of foetal calves.

METHODS AND RESULTS

Growth of the parasite was inhibited by 50% in the presence of 4 mm NaNO2; immediate killing occurred at 10 mm. Mass spectrometric monitoring of gases showed that H2 and CO2 evolution were inhibited by NaNO2, and electron paramagnetic resonance spectrometry revealed a signal similar to that of a thiolate-iron-NO complex. Growth with sublethal concentrations of NaNO2 yielded organisms that produced ethanol rather than H2.

CONCLUSIONS

NaNO2 probably inactivates FeS protein(s) of hydrogenosomes so as to inhibit the conversion of pyruvate (derived from maltose in the growth medium) to H2 and acetate.

SIGNIFICANCE AND IMPACT OF THE STUDY

The use of NaNO2 as a topical antitrichomonal agent in veterinary practice is a possibility. At present, slaughter of infected animals is the favoured method of control.

Effects of soil amendment on gas depth profiles in soil monoliths using direct mass spectrometric measurement

Land use and agricultural practices are known to influence the source and sink concentrations of various gases, including greenhouse gases (NOx CH4 and CO2). in soils. With everincreasing production of domestic sewage sludge and the prohibition of disposal at sea, pressure on waste disposal increases. Anaerobically digested domestic sewage sludge and/or lime were applied to an upland. Scottish soil and their effects on gas depth profiles monitored as indicators of microbial processes of the soil ecosystem. The concentrations of various gases (Ar, O2. CO2, CH4, N2, NOx) were measured simultaneously at each depth using membrane inlet mass spectrometry (MIMS). This technique enables the direct measurement of multiple gas species throughout soil cores with minimal disturbance. Intact soil monoliths were collected from the sample site, following amendment, and maintained in a constant temperature, environmental growth chambers. Statistical analyses (one-way ANOVA and LSD tests) were conducted to identify the depths at which gas concentrations in amended cores were significantly different from those in control (un-amended) cores. Significant effects were observed on the concentration of CO2, CH4, NOx and N2 at certain depths. Average CH4 concentration was consistently higher (>1 microM) in the upper horizon following application of sludge and sludge and lime together. N2 and NOx concentrations were elevated in cores treated with lime by approximately 100 and 32 microM. respectively, in much of the upper horizon. CO2 concentration increased above control mean values, at certain depths, following application of either sludge or lime. Some explanation for the changes in soil gas concentration was provided by reference to the microorganism assemblages and the gases associated with biochemistry of nitrification, denitrification, methane oxidation and methanogenesis.

The antibacterial activity of vancomycin towards Staphylococcus aureus under aerobic and anaerobic conditions

AIMS

To investigate the antibacterial efficacy of vancomycin towards Staphylococcus aureus under aerobic and anaerobic conditions, and to assess the influence of oxygen on the duration of the post-antibiotic effect (PAE) after exposure to vancomycin.

METHODS AND RESULTS

Culture-based techniques and flow cytometric measurements of 5-cyano-2,3-ditolyl tetrazolium chloride (an indicator of redox activity) and the membrane potential-sensitive fluorophore Sytox Green, were used to test four staphylococcal strains. The MICs for all strains, and the duration of PAE, were similar whether tested with or without oxygen. However, a fivefold logarithmic reduction in cell counts was observed in 10-15 h aerobically, depending on strain, compared with longer than 60 h in an anaerobic environment. Flow cytometric data correlated well with counts of colony-forming units under both aerobic and anaerobic conditions.

CONCLUSIONS

The death rate of Staph. aureus exposed to vancomycin was greater in the presence of oxygen, although MIC values and PAE durations were similar whether tested aerobically or anaerobically. Also, flow cytometry provided a rapid and sensitive alternative to plate counts for the assessment of antibiotics in oxygen-free conditions.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study underlines the need for further anaerobic testing using different strain/antibiotic combinations, the results of which will have clinical significance due to the anaerobic nature of some sites of infection.

Towards a standardization of biological dosimetry by cytogenetics

When individuals are accidentally overexposed to ionising radiations, follow-up investigations may include dose assessment by cytogenetics. Scoring of unstable chromosome aberrations (dicentrics, centric rings and acentrics) in peripheral blood lymphocytes is regarded as the most specific method to estimate the exposure dose. It has acquired, in some countries, a medico-legal recognition. Paradoxically, there is no universally adopted technique and so important variations occur in methods and these may influence the quality of results. The only published documents supplying some standardization background are International Atomic Energy Agency (IAEA) Technical Reports No 260 (1986) and 405 (2001). Even they do not address crucial areas such as the organization of service laboratories and the need for quality assurance programmes. The significant role of biological dosimetry in many countries has proved the need for a standardized technique that is compatible with national radiological protection programmes. Thus, an International Standards Organization working group for the standardization of biological dosimetry by cytogenetics was created. This group comprises 13 scientists from 11 countries plus an IAEA representative. On the basis of a group consensus, a text defining minimal constraints on all the steps of the process was proposed. A working draft was submitted to ISO in 2001 and its structure is presented here.

Direct mass spectrometric measurement of gases in soil monoliths

An integrated approach to gas analysis in soil cores was conducted to provide a novel method for observing the gas dynamics associated with upland soil ecosystems. Depth profiles of the O(2), Ar, CO(2), CH(4), N(2) and NO(x) concentrations in intact soil monoliths were obtained simultaneously using membrane inlet mass spectrometry (MIMS). This technique enables the direct measurement of multiple gas species throughout the soil core with minimal disturbance. Depth profiles provided data on the vertical heterogeneity of gas concentrations, while horizontal heterogeneity was monitored by comparison between profiles. Detailed descriptions of the modifications to current MIMS methods for in situ environmental monitoring of terrestrial soils are provided. These included a thorough examination of calibration of the MIMS probe in gas phase, stirred and unstirred H(2)O, or between glass beads immersed in H(2)O. Calibration was also carried out in sterile (autoclaved) soil. The mean concentrations of CO(2) and CH(4) in the soil monoliths increased from 27 microM and undetectable levels respectively at the surface, to maximum values of 3.6 mM and 4.3 microM at 12-cm depth. These changes corresponded with decreases in mean O(2), Ar and N(2) concentration from 300, 20 and 720 microM respectively to 0-6, 10 and 574 microM at 12-cm depth. These data indicated the presence of a gradient within the core from an aerobic environment to an O(2)-depleted, but not in all cases a completely anaerobic, one. This transition corresponded, to some extent, with that between the upper and lower soil horizons. The increased methane and CO(2) concentrations observed at depth are indicative of anaerobic environments. General trends associated with the gradually changing vertical heterogeneity of these gas profiles and the transition towards anaerobiosis did not provide evidence for the existence of localised microsites. Some evidence for microsite-specific microbial communities was however, provided by observation of broad zones of accumulation of NO(x) species, but only at concentrations close to the limit of detection of the method. The ratio of each gas, to argon was calculated at each depth. This was done to correct for physical parameters, which influence inert and biologically active gases, equally. The amount of di-nitrogen as a ratio to Ar was seen to increase with depth. This could be evidence for denitrification in the lower horizon. An example of the dynamic 'online' data collection capabilities is provided for diurnal oscillations in subsurface (5 cm) soil gas concentrations.

The effects on GP prescribing of joining a commissioning group

BACKGROUND

It is not known to what extent general practitioners (GP) can change their prescribing upon joining a commissioning group and what features of a commissioning group may promote prescribing change. The opportunity to study potential prescribing change arose with the formation of a limited number of Primary Care Commissioning Groups (PCCGs), a precursor of Primary Care Groups (PCGs) and Primary Care Trusts (PCTs).

METHODS

This was a controlled study of general practice prescribing costs. All practices (n=24) within one inner city PCCG were compared with matched controls that were not part of a PCCG. Cross sectional survey data was collected from the PCCG practices to determine possible reasons for prescribing change.

RESULTS

The total annual prescribing cost rose by 4.0% in the PCCG practices and by 6.9% in controls (P=0.01). Significant cost containment was found for gastrointestinal prescribing (P=0.03), attributable to differences in the cost of proton pump inhibitors (PPIs) which fell by 0.7% in the PCCG but rose by 7.3% in controls (P=0.03). Total relative savings in the PCCG practices amounted to around pound 220,000. General practitioners making the greater savings in PPI costs within the PCCG, were more likely to report being influenced by information from the prescribing adviser.

CONCLUSION

General practice prescribing costs were contained to a greater degree in practices participating in the PCCG. The differences in gastrointestinal prescribing were most marked for PPIs which were specifically targeted by the prescribing adviser. The GPs themselves attributed their own prescribing change to information provided by the prescribing adviser. Other factors operating within the PCCG may also have influenced prescribing such as a more locally based management system, different financial incentives and a greater degree of co-operative working amongst GPs.

The measurement of shoulder alignment in cricket fast bowling

The aim of this study was to compare thoracic spine alignment with two- and three-dimensional calculations of shoulder alignment (defined as a line joining the acromion processes of the right and left scapula) when all measures were projected onto the transverse plane. A six-camera Vicon system was used to reconstruct three markers positioned on the plane of the thorax such that the orthogonal vector to the thoracic spine, projected onto the transverse plane, was used as a virtual shoulder alignment during cricket fast bowling. This same measurement system was used to calculate the three-dimensional line between the acromion processes projected onto the transverse plane. These acromion markers were also used to calculate the two-dimensional transverse plane alignment of the shoulders from images recorded by a video camera positioned above ball release. All cameras operated at 50 Hz. A significant association was recorded between thorax alignment and the three- (0.97) and two-dimensional (0.87) shoulder alignment estimations at back-foot impact. The strength of association remained at front-foot impact, when correlations of 0.89 (three-dimensional) and 0.84 (two-dimensional) were recorded. However, at ball release, non-significant associations of 0.58 (three-dimensional) and 0.41 (two-dimensional), representing shoulder alignment differences of approximately 10 degrees, were recorded. The 95% limits of agreement comparisons for shoulder alignment at back-foot impact, front-foot impact and ball release produced mean random errors for the two comparisons of 9.5 degrees, 11.7 degrees and 22.5 degrees respectively. Three- and two-dimensional transverse plane projections of shoulder alignment are reasonable estimates of thorax alignment at back-foot impact and front-foot impact but not at ball release.

Choosing metaphases for biological dosimetry by fluorescence in situ hybridization (FISH)

Data are presented for a subset of lymphocytes characterized by FISH as missing painted chromosomal material. These lymphocytes occur in both control and irradiated subjects. These cells have a much greater frequency of one-way translocations than cells in which all of the painted chromosomal material is present. Their presence contributes to interindividual variability in control translocation yields. These cells do not appear to be more prevalent in persons exposed to high radiation doses. It is suggested that their exclusion when selecting cells for analysis may improve the sensitivity of FISH as a biological dosimeter at low doses. Mechanisms for the production of these one-way translocations in vivo are also discussed, with a proposal that their variable frequency in individuals may be consistent with exposure to chemical clastogens.

Modified Longo's hemorrhoidectomy

The Longo technique of stapled hemorrhoidectomy is rapidly gaining world-wide acceptance. However, hemorrhoids with large external components are often left with troublesome skin tags after the Longo technique. In this article we present modifications to the Longo technique that make it easier to perform and provide adequate treatment of hemorrhoids that have a significant external component or skin tags.

The Scottish doctor--learning outcomes for the medical undergraduate in Scotland: a foundation for competent and reflective practitioners

This paper describes a set of learning outcomes that clearly define the abilities of medical graduates from any of the five Scottish medical schools. The outcomes are divided into 12 domains that fit into one of three essential elements for the competent and reflective medical practitioner.

Information architecture for a federated health record server

This paper describes the information models that have been used to implement a federated health record server and to deploy it in a live clinical setting. The authors, working at the Centre for Health Informatics and Multiprofessional Education (University College London), have built up over a decade of experience within Europe on the requirements and information models that are needed to underpin comprehensive multi-professional electronic health records. This work has involved collaboration with a wide range of health care and informatics organisations and partners in the healthcare computing industry across Europe though the EU Health Telematics projects GEHR, Synapses, EHCR-SupA, SynEx and Medicate. The resulting architecture models have fed into recent European standardisation work in this area, such as CEN TC/251 ENV 13606. UCL has implemented a federated health record server based on these models which is now running in the Department of Cardiovascular Medicine at the Whittington Hospital in North London. The information models described in this paper reflect a refinement based on this implementation experience.

The antioxidant potential of pyruvate in the amitochondriate diplomonads Giardia intestinalis and Hexamita inflata

Giardia intestinalis and Hexamita inflata are microaerophilic protozoa which rely on fermentative metabolism for energy generation. These organisms have developed a number of antioxidant defence strategies to cope with elevated O(2) tensions which are inimical to survival. In this study, the ability of pyruvate, a central component of their energy metabolism, to act as a physiological antioxidant was investigated. The intracellular pools of 2-oxo acids in G. intestinalis were determined by HPLC. With the aid of a dichlorodihydrofluorescein diacetate-based assay, intracellular reactive oxygen species generation by G. intestinalis and H. inflata suspensions was monitored on-line. Addition of physiologically relevant concentrations of pyruvate to G. intestinalis and H. inflata cell suspensions was shown to attenuate the rate of H(2)O(2)- and menadione-induced generation of reactive oxygen species. In addition, pyruvate was also shown to decrease the generation of low-level chemiluminescence arising from the oxygenation of anaerobic suspensions of H. inflata. In contrast, addition of pyruvate to suspensions of respiring Saccharomyces cerevisiae was shown to increase the generation of reactive oxygen species. These data suggest that (i) in G. intestinalis and H. inflata, pyruvate exerts antioxidant activity at physiological levels, and (ii) it is the absence of a respiratory chain in the diplomonads which facilitates the observed antioxidant activity.

Antigiardial drugs

Giardia intestinalis is a world-wide cause of intestinal infection. Treatment of this debilitating disease is usually accomplished using one of several drugs. Metronidazole is the treatment of choice, but benzimidazoles are now being used more frequently. Other treatments include quinacrine, paromomycin and furazolidone. Even though these drugs are all used to treat the same disease, their modes of action differ in all cases. However, resistance is increasing and new alternatives are being sought. New wave antigiardials all appear to have their roots in natural herbal remedies. This mini-review looks at the current treatments available, their efficacy, side effects and different modes of action and addresses a possible way forward using natural products.

Clock control of ultradian respiratory oscillation found during yeast continuous culture

A short-period autonomous respiratory ultradian oscillation (period approximately 40 min) occurs during aerobic Saccharomyces cerevisiae continuous culture and is most conveniently studied by monitoring dissolved O(2) concentrations. The resulting data are high quality and reveal fundamental information regarding cellular dynamics. The phase diagram and discrete fast Fourier transformation of the dissolved O(2) values revealed a square waveform with at least eight harmonic peaks. Stepwise changes in temperature revealed that the oscillation was temperature compensated at temperatures ranging from 27 to 34 degrees C when either glucose (temperature quotient [Q(10)] = 1.02) or ethanol (Q(10) = 0.82) was used as a carbon source. After alteration of the temperature beyond the temperature compensation region, phase coherence events for individual cells were quickly lost. As the cell doubling rate decreased from 15.5 to 9.2 h (a factor of 1.68), the periodicity decreased by a factor of 1.26. This indicated that there was a degree of nutrient compensation. Outside the range of dilution rates at which stable oscillation occurred, the mode of oscillation changed. The oscillation in respiratory output is therefore under clock control.

Antimicrobial properties of Allium sativum (garlic)

Although garlic has been used for its medicinal properties for thousands of years, investigations into its mode of action are relatively recent. Garlic has a wide spectrum of actions; not only is it antibacterial, antiviral, antifungal and antiprotozoal, but it also has beneficial effects on the cardiovascular and immune systems. Resurgence in the use of natural herbal alternatives has brought the use of medicinal plants to the forefront of pharmacological investigations, and many new drugs are being discovered. This review aims to address the historical use of garlic and its sulfur chemistry, and to provide a basis for further research into its antimicrobial properties.

Counter-stimulatory effects on pain perception and processing are significantly altered by attention: an fMRI study

Counter-stimulation reduces pain perception; however, the role of attention during this process is rarely discussed despite attention itself being a well known modulator of pain perception. This study investigated the effect of attentional modulation on pain perception during counter-stimulation using fMRI. Subjects received a noxious thermal stimulus together with an innocuous vibratory counter-stimulus. Subjects directed their attention towards either pain, vibration, or a neutral visual stimulus. During painful and counter-stimulation all subjects reported a reduction in pain perception when attending to counter-stimulation compared with attending to pain. Imaging data supported this behavioural finding showing reduced activity in pain processing areas (anterior cingulate, insula, thalamus). These results suggest attention plays an important part in the pain relief experienced from counter-stimulation.

Vision influences tactile perception at body sites that cannot be viewed directly

Previous research has demonstrated that vision of a body site, without proprioceptive orienting of eye and head to that site, could affect tactile perception. The body site viewed was the hand, which can be seen directly under normal viewing conditions. The current research asked three further questions: First, can vision similarly affect tactile perception at a body site that cannot normally be viewed directly such as the face or neck? Second, does prior experience of seeing a body site, such as occurs when viewing the face in mirrors, produce larger effects of viewing than body sites rarely seen such as the back of the neck? And third, how quickly can visual information affect tactile target detection? We observe that: detection of tactile targets at these body sites was influenced by whether or not they were viewed, this effect was greater when viewing the more familiar site of the face than that of the neck, and significant effects were observed when the stimulus onset asynchrony between visual display and tactile target was as little as 200 ms.