Temporal differences and commonalities between hand and tool neural processing

Object recognition is a complex cognitive process that relies on how the brain organizes object-related information. While spatial principles have been extensively studied, less studied temporal dynamics may also offer valuable insights into this process, particularly when neural processing overlaps for different categories, as it is the case of the categories of hands and tools. Here we focus on the differences and/or similarities between the time-courses of hand and tool processing under electroencephalography (EEG). Using multivariate pattern analysis, we compared, for different time points, classification accuracy for images of hands or tools when compared to images of animals. We show that for particular time intervals (~ 136-156 ms and ~ 252-328 ms), classification accuracy for hands and for tools differs. Furthermore, we show that classifiers trained to differentiate between tools and animals generalize their learning to classification of hand stimuli between ~ 260-320 ms and ~ 376-500 ms after stimulus onset. Classifiers trained to distinguish between hands and animals, on the other hand, were able to extend their learning to the classification of tools at ~ 150 ms. These findings suggest variations in semantic features and domain-specific differences between the two categories, with later-stage similarities potentially related to shared action processing for hands and tools.

17α-Ethinylestradiol and 17β-estradiol removal from a secondary urban wastewater using an RBC treatment system

The presence of micropollutants that include endocrine-disrupting compounds (EDC) in aquatic environments is currently one of the most relevant aspects of water quality due to their adverse effects on aquatic organisms and human health. From the several categories of EDC, 17β-estradiol (E2) is a natural hormone, which is prevalent in vertebrates, associated with the female reproductive system and maintenance of the sexual characters. 17α-Ethinylestradiol (EE2) is a synthetic hormone produced from the natural hormone E2 and is an essential component of oral contraceptives. These compounds are susceptible to bioconcentration and have high potential to bioaccumulation. Wastewater treatment plants are the main point source of E2 and EE2 into aquatic environments, but conventional wastewater treatment systems are not specifically designed for steroid removal. To overcome this problem, biological tertiary treatment may be a solution for the removal of emergent pollutants such as E2 and EE2. The main purpose of the present study is to provide a solution based on the optimization of a rotating biological contactor system to remove estrogens, specifically E2 and EE2, and to quantify their removal efficiency on different matrices, namely real wastewater and different synthetic wastewaters. All assays presented viable removal efficiencies for compound E2 with values always above 50%; real wastewater yielded the highest removal efficiencies. EE2 removal had better removal efficiencies with synthetic wastewater as feed solution, with removals above 15%, whereas the removal efficiency with real wastewater was inexistent.

EPR and 51V NMR studies of prospective anti-diabetic bis(3-hydroxy-4-pyridinonato)oxidovanadium(iv) complexes in aqueous solution and liposome suspensions

EPR/⁵¹V-NMR parallel studies of [VO(3,4-HPO)₂] complexes in MOPS buffer and POPC liposome suspensions provide information regarding solvents for oral administration.

The Vespid Allergy Quality of Life Questionnaire - cultural adaptation and translation to Portuguese

A cross-cultural translation of the Vespid Allergy Quality of Life Questionnaire (VQLQ) to the Portuguese population (VQLQ-P) was performed, assessing its applicability in wasp and in non-beekeeper bee venom allergic patients. Additionally, we evaluated a Visual Analogue Scale (VAS) to estimate hymenoptera allergy interference with daily life. Methods. Cross-cultural translation was performed according to recommendations. The final VQLQ-P version, the Expectation of Outcome questionnaire (EoQ), EQ-5D and VAS were applied to wasp (n = 19) and non-beekeeper bee venom allergic patients (n = 30). Results. VQLQ-P significantly correlated with EoQ, (r = 0.76, p < 0.01), EQ-5D (usual activities and anxiety / depression dimensions) and VAS, with a good internal consistency (Cronbach α = 0.88) in wasp allergic individuals. VQLQ-P and EoQ correlation was also high (r = 0.67, p < 0.01) in bee allergy. Conclusion. The VQLQ-P is a valuable tool to evaluate quality of life impairment in Portuguese hymenoptera venom allergic individuals.

Hemispheric asymmetries in subcortical visual and auditory relay structures in congenital deafness

Neuroplasticity - the capacity of the brain to change as a response to internal and external pressures - has been studied from a number of different perspectives. Perhaps one of the most powerful models is the study of populations that have been congenitally deprived of a sense. It has been shown that the right Auditory Cortex (AC) of congenitally deaf humans is neuroplastically modified in order to represent visual properties of a stimulus. One unresolved question is how this visual information is routed to the AC of congenitally deaf individuals. Here, we performed volumetric analysis of subcortical auditory and visual brains regions - namely the thalamus (along with three thalamic nuclei: the pulvinar, the lateral geniculate nucleus and the medial geniculate nucleus), and the inferior and superior colliculi - in deaf and hearing participants in order to identify which structures may be responsible for relaying visual information toward the altered AC. Because there is a hemispheric asymmetry in the neuroplastic changes observed in the AC of the congenitally deaf, we reasoned that subcortical structures that also showed a similar asymmetry in their total volume could have been enlisted in the effort of relaying visual information to the neuroplastically altered right AC. We show that for deaf, but not for hearing individuals, the right thalamus, right lateral geniculate nucleus and right inferior colliculus are larger than their left counterparts. These results suggest that these subcortical structures may be responsible for rerouting visual information to the AC in congenital deafness.

Biodegradation or simple adsorption to the support material? Development of a simple, fast and low-cost technique

Biofilms are present in several areas and are studied in microbiology, medical sciences, biology and, of course, sanitary engineering. Biofilms are used for the treatment of municipal wastewater, and their application was even before the invention of the activated sludge process. The main objective of this work was to develop a simple, fast and low-cost technique to evaluate the nature of the first decay in the concentration of an organic compound in the presence of a solid material. Though simple, the technique developed has allowed the clarification of whether the initial concentration decay is due to adsorption to the support material or a result of biodegradation. The results show that, with two different support materials, adsorption does not take place, and the biodegradation processes are responsible for the first decay in the organic concentration. The technique used offers a fast and low-cost way of studying the existence of adsorption. Two feed concentration solutions and two different support materials were used.

Ulnar variance related to biological and training characteristics and handgrip strength in Portuguese skeletally immature female gymnasts

AIM

The aims of this study were to investigate the ulnar variance in a group of skeletally immature female gymnasts of different age and skill level and to investigate the left-right differences in ulnar variance and its relationship with biological and training characteristics and handgrip strength.

METHODS

Thirty-three Portuguese skeletally immature female gymnasts (mean age 11.1 years) of different age-related categories completed a questionnaire detailing their training characteristics. Besides maturation, stature, body mass, and body composition, also handgrip strength of both hands were measured. Left and right ulnar variance was obtained using Hafner's procedure and skeletal age through the Tanner-Whitehouse 3-method.

RESULTS

Mean skeletal age (10.1±1.9 yr) is one year younger than chronological age (11.1±2.1 yr) and this discrepancy becomes more pronounced with increasing age-category. Gymnasts presented on average 6.1 years of training and 16.7 hours/week. A negative mean value for both the left and right ulnar variance measures was observed (between -1.7 mm and -3.1 mm) but with increasing age-category there is a trend that ulnar variance becomes more positive (between +0.3 mm and -1 mm). Significant differences between right and left ulnar variance were demonstrated. Correlations between ulnar variance and biological and training characteristics and handgrip strength are rather low and not significant, except for skeletal age (r=0.38), stature (r=0.41) and fat-free mass (r=0.48).

CONCLUSION

Despite some significant results the main results of this study do not directly support the thesis that gymnastics training or handgrip strength are associated with ulnar variance.

In vitro cytotoxic activity of novel protoflavone analogs - selectivity towards a multidrug resistant cancer cell line

BACKGROUND

Protoapigenone (PA), a natural flavonoid possessing an unusual p-quinol moiety on its B ring, is a prospective novel lead compound against cancer currently in development, together with WYC0209, a potent synthetic PA analog. Structure activity relationships (SAR) concerning different 1'-O-alkyl side-chains were also studied on two sets of derivatives.

MATERIALS AND METHODS

Fifteen 1'-O-alkyl protoflavone derivatives were synthesized from genkwanin or 4'-hydroxy-6-methylflavone, thirteen of which are new compounds. All compounds were tested for their cytotoxic effect on four human cancer cell lines, such as HepG2 and Hep3B (hepatic), A549 (lung) and MDA-MB-231 (breast) cell lines, with doxorubicin as a positive control. All compounds, as well as PA, WYC0209 and fourteen of their previously reported analogs were also tested on a multidrug-resistant (MDR) sub-cell line of L5178 mouse T-cell lymphoma and on its parental counterpart (PAR).

RESULTS

In general, derivatives bearing a free hydroxyl group at C-1' exerted the strongest activities, while C-1'-substituted compounds were found to be much weaker. Derivatives of 6-methylflavone exhibited mild, but statistically significant selectivity towards the MDR cell line.

CONCLUSION

The results are in agreement with our previous findings for fundamental SAR of protoflavones. 6-Methylated protoflavones may serve as valuable leads for developing selective compounds against MDR cancer. Identical activity of other derivatives on the PAR and MDR cell lines suggests that cancer cells cannot exhibit resistance to protoflavones by ABCB1 efflux pump overexpression.

Rapid, laser-induced conversion of 20-hydroxyecdysone and its diacetonide -- experimental set-up of a system for photochemical transformation of bioactive substances

BACKGROUND

Photochemical transformation of certain bioactive compounds for the purpose of obtaining derivatives with increased bioactivity is a prospective area of synthetic chemistry. Ecdysteroids, analogs of the insect molting hormone, which can also exert several beneficial effects in mammals including humans, contain an enone moiety in their B ring, and, as such, are good candidates for photochemical transformations.

MATERIALS AND METHODS

20-hydroxyecdysone (20E), the most common ecdysteroid in Nature, and the easily obtained derivative 20-hydroxyecdysone 2,3;20,22-diacetonide (20ED), at different concentrations, were exposed to a 266 nm laser beam at an energy level of 6.5 mJ for different periods of time and evaluated for fluorescence emission during the process of irradiation. The products of irradiation were scanned from 200 to 1500 nm and then subjected to one-dimensional and two-dimensional thin layer chromatography.

RESULTS

During irradiation, progressive significant changes in the fluorescence emission spectra were noted for both compounds with time that were accompanied by changes in their UV-Vis spectra. Full conversion of both compounds was reached within 14 minutes, and both compounds yielded several major products and several minor ones representing a wide polarity range.

CONCLUSION

The photo-transformation system described here was proven to be a useful and flexibly adjustable tool for the laser-catalyzed conversion of bioactive compounds. Due to the multi-drug resistance reversal activity of the less polar ecdysteroids, several new products are promising for being tested against various cancer cell lines. Fractionation, isolation and characterization of the irradiated products are currently in process.

Identification of the plasmid-encoded qacA efflux pump gene in meticillin-resistant Staphylococcus aureus (MRSA) strain HPV107, a representative of the MRSA Iberian clone

Meticillin-resistant Staphylococcus aureus (MRSA) is a major nosocomial bacterium for which prevention and control measures consist mainly of the application of biocides with antiseptic and disinfectant activity. In this study, we demonstrated the presence of the plasmid-located efflux pump gene qacA in MRSA strain HPV107, a clinical isolate representative of the MRSA Iberian clone. The existence of efflux activity in strain HPV107 due to the QacA pump was also established and this QacA efflux activity was linked with a phenotype of reduced susceptibility towards several biocide compounds. No association could be made with antibiotic resistance. This work emphasises the potential of QacA pump activity in the maintenance and dissemination of important MRSA strains in the hospital setting and, increasingly, in the community.

Non-antibiotics reverse resistance of bacteria to antibiotics

BACKGROUND

Most clinical isolates that exhibit a multi-drug resistant phenotype owe that resistance to over-expressed efflux pumps. Compounds that are efflux pump inhibitors (EPIs) reduce or reverse resistance to antibiotics to which the bacterial strain is initially resistant. We have evaluated non-antibiotics to reduce resistance of commonly encountered bacterial pathogens to antibiotics.

MATERIALS AND METHODS

The effect of non-antibiotics on the susceptibility of bacteria to antibiotics was conducted by minimum inhibition concentration determinations of the antibiotic in the absence and presence of the non-antibiotic.

RESULTS

Non-antibiotics such as chlorpromazine, amitryptiline and trans-chlorprothixene are shown to reduce or reverse resistance of a variety of bacteria to antibiotics.

CONCLUSION

The results suggest that non-antibiotics may serve as adjuncts to conventional antibiotics for the therapy of problematic antibiotic infections caused by bacteria that owe their resistance to over-expressed efflux pumps.

Physiological characterisation of the efflux pump system of antibiotic-susceptible and multidrug-resistant Enterobacter aerogenes

Enterobacter aerogenes predominates amongst Enterobacteriaceae species that are increasingly reported as producers of extended-spectrum beta-lactamases. Although this mechanism of resistance to beta-lactams is important, other mechanisms bestowing a multidrug-resistant (MDR) phenotype in this species are now well documented. Amongst these mechanisms is the overexpression of efflux pumps that extrude structurally unrelated antibiotics prior to their reaching their targets. Interestingly, although knowledge of the genetic background behind efflux pumps is rapidly advancing, few studies assess the physiological nature of the overall efflux pump system of this, or for that matter any other, bacterium. The study reported here evaluates physiologically the efflux pump system of an E. aerogenes ATCC reference as well as two strains whose MDR phenotypes are mediated by overexpressed efflux pumps. The activities of the efflux pumps in these strains are modulated by pH and glucose, although the effects of the latter are essentially restricted to pH 8, suggesting the presence of two general efflux pump systems, i.e. proton-motive force-dependent and ABC transporter types, respectively.

Ferromagnetism induced by oxygen and cerium vacancies above the percolation limit in CeO2

We studied the structural, chemical and magnetic properties of non-doped ceria (CeO(2)) thin films electrodeposited on silicon substrates. Experimental results confirm that the observed room temperature ferromagnetism is driven by both cerium and oxygen vacancies. We investigated ceria films presenting vacancy concentrations well above the percolation limit. Irradiation experiments with neon ions were employed to generate highly oxygen defective CeO(2-δ) structures. X-ray photoelectron spectroscopy and x-ray absorption near-edge structure spectroscopy were used to estimate the concentration of Ce(3+) sites in the films, which can reach up to 50% of Ce(3+) replacing Ce(4+), compared to a stoichiometric CeO(2) structure. Despite the increment of structural disorder, we observe that the saturation magnetization continuously increases with Ce(3+) concentration. Our experiments demonstrate that the ferromagnetism observed in ceria thin films, highly disordered and oxygen-deficient, preserving the fluorite-type structure only in a nanometer scale, remains intrinsically stable at room temperature.

Constituents of Carpobrotus edulis inhibit P-glycoprotein of MDR1-transfected mouse lymphoma cells

A bioassay-guided separation protocol, including the testing of the extracts, fractions and pure compounds for their ability to inhibit P-glycoprotein (the efflux pump responsible for the multidrug resistance of the used cell line) of mouse lymphoma cells containing the human efflux pump gene MDR1, led to the isolation of seven compounds from the chloroform and ethyl acetate soluble fractions of the methanolic extract of Carpobrotus edulis. The compounds were identified by 1D, 2D NMR and MS investigations as triterpens (beta-amyrin, uvaol and oleanolic acid), monogalactosyldiacylglycerol, catechin, epicatechin and procyanidin B5. Uvaol was the most effective and promising compound in the reversal of multidrug resistance in MDR mouse lymphoma cell line.

Influence of bed media characteristics on ammonia and nitrate removal in shallow horizontal subsurface flow constructed wetlands

Two bed media were tested (gravel and Filtralite) in shallow horizontal subsurface flow (HSSF) constructed wetlands in order to evaluate the removal of ammonia and nitrate for different types of wastewater (acetate-based and domestic wastewater) and different COD/N ratios. The use of Filtralite allowed both higher mass removal rates (1.1 g NH(4)-N m(-2) d(-1) and 3 g NO(3)-N m(-2) d(-1)) and removal efficiencies (>62% for ammonia, 90-100% for nitrate), in less than 2 weeks, when compared to the ones observed with gravel. The COD/N ratio seems to have no significant influence on nitrate removal and the removal of both ammonia and nitrate seems to have involved not only the conventional pathways of nitrification-denitrification. The nitrogen loading rate of both ammonia (0.8-2.4 g NH(4)-N m(-2) d(-1)) and nitrate (0.6-3.2 g NO(3)-N m(-2) d(-1)) seem to have influenced the respective removal rates.

[Ambulatory surgery in urology: first numbers of a successful program]

The ambulatory surgery includes those surgical procedures that require a small period of post-operative recovery so that the patients will be discharged from the hospital in the same day of the surgical intervention. In Urology, the vast amount of pathology that allows the cure with medium and low complexity surgical procedures makes this specialty a privileged one in which ambulatory surgery is concerned. In this paper the authors propose to describe how their Urology group works in the ambulatory field. 472 patients where reviewed in an evaluation period from January 2006 to April 2008. The medical appointment protocol is summarized as well as the most common surgical procedures and complications. Annually we operate an average of 200 ambulatory patients and this represents about 22% of the hole surgical activity of the Urology group. The majority of the surgeries are circumcisions and vasectomies (always associated with other small procedures). There is a 5 hours weakly period where a total of 5 to 6 patients are operated. Surgical complications represented 1.6% of total procedures, all of them late ones. With this specific ambulatory program our service managed to reduce drastically the waiting time for this kind of procedures (now-a-days is about 3-4 weeks), with a satisfaction rate of about 95%. According to the great outcomes, low complications rate and great acceptance of the patients, the development of this unit is without doubt a winning project in patients care.

Identification of nontuberculous mycobacteria in clinical samples using molecular methods: a 3-year study

Nontuberculous mycobacteria (NTM) are being increasingly isolated in clinical laboratories and present technical and therapeutic challenges. In the present study, we report our experience with the identification of NTM received from 12 Lisbon hospitals over a 3-year period using GenoType Mycobacterium (CM/AS) assays (HAIN Lifescience GmbH, Nehren, Germany). Together, the two kits identified 96.6% of all NTM isolates tested. Among the 18 NTM species identified, Mycobacterium avium complex was the most frequent, although it accounted for only 34% of all NTM. Introducing these methods for the rapid identification of NTM highlights the importance of NTM as potential pathogens and assisted the selection of adequate therapy.

An AcrAB-mediated multidrug-resistant phenotype is maintained following restoration of wild-type activities by efflux pump genes and their regulators

In this study, we aimed to answer the following question: 'How does a bacterium become so resistant to a given antibiotic even though the levels of antibiotic to which it has become resistant remained constant in the patient?'Escherichia coli AG100 strain induced to high-level resistance due to overexpression of an AcrAB efflux pump was serially cultured in 10mg/L tetracycline for 60 passages. Between each passage it became increasingly resistant to tetracycline, beta-lactams and quinolones with concomitant restoration of wild-type AcrAB activity. Because the multidrug-resistant phenotype could not be reversed with transfer to drug-free medium or with efflux pump inhibitors, it may have resulted from activation of a 'mutator gene' system that reduced the 'energy consumption' associated with an overexpressed efflux pump system.

Targeting human macrophages for enhanced killing of intracellular XDR-TB and MDR-TB

Although many compounds have been described to inhibit the replication of drug-susceptible and drug-resistant strains of Mycobacterium tuberculosis, most of these studies only evaluate their in vitro activity. There is a lack of studies that show whether any of these agents can kill these organisms at the site where they normally reside post infection, namely, the macrophage of the lung parenchyma. It is the aim of this mini-review to identify agents that have been shown to enhance the killing of intracellular drug-susceptible, multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant TB (XDR-TB) strains by non-killing macrophages. Because these agents appear to promote their activity by affecting the transport of K(+) and Ca(2+) from the phagolysosome containing the bacteria, and thereby promoting its acidification and activation of hydrolases that will eventually kill the organism, the authors suggest that compounds that are known to affect the transport of K(+) and Ca(2+) should be considered for possible activity against intracellular MDR- and XDR-TB.

Potent bactericidal action of a flavonoid fraction isolated from the stem bark of Butea frondosa

The flavonoid fraction isolated from the ethyl acetate fraction (BF-1) of Butea frondosa (L.) stem bark exhibited distinct antimicrobial activity when tested against 129 bacterial strains belonging to 9 different genera of both gram-positive and gram-negative types. Minimum inhibitory concentration (MIC) of the fraction BF-1 was determined following NCCLS guidelines using the agar dilution method. Twenty-four out of 36 strains of Staphylococcus aureus were inhibited by 50-200 mg/l of the fraction. This fraction also inhibited strains of Bacillus spp., Shigella spp., Salmonella spp. and even a few Pseudomonas at concentrations between 50-200 mg/l. Other bacteria including Escherichia coli, Vibrio cholerae and V. parahaemolyticus were moderately sensitive to BF-1. In the in vivo studies, this fraction offered significant protection to Swiss albino mice at a concentration of 80 microg/mouse (p<0.001) when they were challenged with 50 median lethal dose of Salmonella enteritidis NCTC 74. A fraction named BF-1 that was isolated from an ethyl acetate fraction of Butea frondosa provided protection against an infection from a Salmonella enteritidis NCTC strain.

Promising therapy of XDR-TB/MDR-TB with thioridazine an inhibitor of bacterial efflux pumps

Global rates of pulmonary tuberculosis (TB) continue to increase. Moreover, resistance of the causative organism Mycobacterium tuberculosis to the two most effective anti-TB medications continue to rise. Now, multi-drug resistant TB (MDR-TB) has progressed to extensively drug resistant TB (XDR-TB) - a M. tuberculosis organism that is resistant to the most effective second line drugs available for the treatment of TB. This review provides detailed, significant evidence that supports the use of an old neuroleptic compound, thioridazine (TZ), for the management of MDR-TB and XDR-TB infections and which has been shown to inhibit efflux pumps of bacteria. The argument has been previously presented but no one seems to be listening - and the disease continues unabated when there is a very good probability that the suggested drug will prove to be effective. When the prognosis is poor, available therapy predictably ineffective and death is inevitable, compassionate therapy with TZ should be contemplated. The risks are small and the rewards great.

Phenothiazines as anti-multi-drug resistant tubercular agents

Pulmonary tuberculosis (TB) has again become a global problem: it infects 2.2 billion people world-wide, caused the deaths of over 3 million last year and will produce over 8 million new cases of TB this coming year. Although effective therapy is widely available for antibiotic susceptible strains of Mycobacterium tuberculosis, current drugs are relatively useless against multi-drug resistant infections (MDRTB). Mortality is almost complete within two years regardless of therapy, and in the case of co-infection with HIV/AIDS, mortality is 100% within a few months of diagnosis especially the M. tuberculosis strain in XDRTB. As of the time of this writing no new effective anti-TB drugs have been made available by the pharmaceutical industry and XDRTB. Because TB is an intracellular infection of the non-killing macrophage of the lung, any agent that is to prove effective must have activity against MDRTB and XDRTB strains that have been phagocytosed by the human macrophage. This review intents to provide cogent in vitro, ex vivo and in vivo evidence that supports the use of a variety of commonly available phenothiazines for the therapy of MDRTB and XDRTB, especially when the prognosis of the infection is poor and the use of the recommend agents can take place along lines of "compassionate therapy". In addition, we will describe the macrophage assay as indispensable when an agent is to be further studied for its effectiveness as an anti-TB drug. In vitro studies if not complemented by ex vivo studies will for the most part be dead-ended since few agents that have activity in vitro have any activity against phagocytosed M. tuberculosis.

A characterization of selected endocrine disruptor compounds in a Portuguese wastewater treatment plant

Anthropogenic compounds that are able to disrupt the endocrine system of wildlife species are a major cause for concern and have led to a demand for new screening methods. The identification and quantification of endocrine disruptor compounds at wastewater treatment plant is of major interest to assess the endocrine activity of wastewater treatment plant discharges into the environment. This study consists of a preliminary survey of concentrations of previously selected endocrine disruptor compounds, undertaken to establish environmental concentrations and to support a biological program assay exposing freshwater fish to them. Selected endocrine disrupting chemicals (APEs, bisphenol A and 17 beta-estradiol) were measured in samples from a wastewater treatment plant located in Lisbon (Portugal), using recent commercial enzyme-linked immunosorbent assay kits and also LC-MS/MS. The results show that the wastewater treatment plant treatment process is efficient on the removal of target endocrine disruptor compounds. However, environmentally significant concentrations are still present in the treated effluent. The results also show that enzyme-linked immunosorbent assay kit is suitable for routine analysis of the selected compounds. The results are also useful since the wastewater treatment plant is located in a Mediterranean region, which results in an effluent with its own characteristics.

Phenothiazines: potential alternatives for the management of antibiotic resistant infections of tuberculosis and malaria in developing countries

The in vitro and in vivo activity of phenothiazines against antibiotic susceptible and antibiotic resistant Mycobacterium tuberculosis and malaria-causing Plasmodia is reviewed. Given the facts that pulmonary tuberculosis and malaria are the major causes of death in developing countries, that both of these infections continue to escalate in their resistance to antibiotics, that the cost for the management of these infections is beyond that afforded by most developing nations, and lastly, that new and effective agents are not forthcoming from the pharmaceutical industry, the scientific rationale for the potential use of select phenothiazines for the management of these infections is presented.

Phenothiazines: potential management of Creutzfeldt-Jacob disease and its variants

Creutzfeldt-Jakob disease acquired from bovines (nvCJD) has been responsible for nearly 100 deaths in the UK and thousands more may die in the years to come. New variant CJD (nvCJD) is incurable and although clinical diagnosis is becoming more precise, the diagnosis is only certain at autopsy. Phenothiazine derivatives inhibit production of prions, the disease causing agent, in cultured neuroblastoma cells, and an advanced case of nvCJD was recently brought to remission by the use of these agents in combination with an antimalarial. In this review we present direct and circumstantial evidence in support of a model describing the manner by which the intracellular antimicrobial activity of phenothiazines might cause the destruction of intracellular prions.

Activity of phenothiazines against antibiotic-resistant Mycobacterium tuberculosis: a review supporting further studies that may elucidate the potential use of thioridazine as anti-tuberculosis therapy

The in vitro and in vivo anti-mycobacterial activities of a number of phenothiazine compounds are reviewed. These compounds, normally employed for the management of psychosis, inhibit the growth in vitro of Mycobacterium tuberculosis at concentrations that are significantly greater than those that can safely be achieved in a patient harbouring these infections. Nevertheless, one of these phenothiazines, chlorpromazine, is concentrated by human macrophages to 10-100 times its concentration in plasma, and has activity against mycobacteria that have been phagocytosed by these cells. Phenothiazines have significant in vitro activity against susceptible, polydrug- and multidrug-resistant strains of M. tuberculosis, as well as enhancing the activity of some agents employed for first-line treatment. Because thioridazine, the very mild anti-psychotic agent whose most common side effect is drowsiness, has equal anti-tuberculosis properties in vitro to chlorpromazine, we recommend that thioridazine be studied as an adjuvant to the four- or five-drug regimens employed for the management of a freshly diagnosed tuberculosis infection of unknown antibiotic susceptibility, at least during the period required for the assessment of antibiotic susceptibility. Because it also enhances the activity of rifampicin and streptomycin, antibiotics that frequently have adverse effects, additional studies evaluating the use of thioridazine as an adjuvant may eventually allow a reduction in the dosages of these antibiotics and result in a decreased frequency of adverse effects. It is important to note that whereas the management of patients with thioridazine for periods in excess of many months will result in the appearance of some undesirable side effects, its use for a limited period of 2-3 months should not produce side effects that are more severe than simple drowsiness. Nevertheless, further in vitro and in vivo studies are essential before thioridazine may be recommended for the management of select cases of pulmonary tuberculosis.

Enhancement of antibiotic activity against poly-drug resistant Mycobacterium tuberculosis by phenothiazines

Phenothiazines have been shown to inhibit the in vitro growth of multi-drug resistant (resistant to rifampicin and isoniazid) Mycobacterium tuberculosis (MDRTB). They have been considered as potential adjuvants to regimens employing four or more antibiotics for the management of freshly diagnosed infections of M. tuberculosis in patients from areas known to have a high prevalence of MDRTB. Chlorpromazine has been shown to enhance the activity of antibiotics (except ethambutol) to which M. tuberculosis is susceptible. This might result in a reduction in the dose of some or all of the antibiotics employed without sacrificing the integrity of treatment. Chlorpromazine, thioridazine and promethazine were shown to enhance the activity of rifampicin and streptomycin when used in combinations at concentrations that are minimally effective when employed separately against clinical strains of M. tuberculosis resistant to two or more antibiotics (poly-drug resistant MTB). The phenothiazines had no effect on the activity of isoniazid against poly-drug resistant MTB.

Comparative in vitro activity of phenothiazines against multidrug-resistant Mycobacterium tuberculosis

The comparative activity of five phenothiazines against multidrug-resistant strains of Mycobacterium tuberculosis (MDRTB) was studied using the Bactec 460 system. The order of antimycobacterial activity of the phenothiazines was: chlorpromazine = thioridazine > promethazine > promazine = desipramine. However, the levels required for an MIC 50 exceeded 1 mg/l and are beyond those that are clinically achievable. As phenothiazines are concentrated by macrophages that phagocytose and have in situ activity against mycobacteria, these agents may be considered for use as adjuvants for the management of freshly diagnosed tuberculosis in patients from populations with a high prevalence of MDRTB.

The effects of chlorpromazine on the outer cell wall of Salmonella typhimurium in ensuring resistance to the drug

Chlorpromazine (CPZ), a compound employed for the management of psychosis, has a wide ranging antibacterial activity. The growth of Salmonella typhimurium100 mg/l), was initially inhibited during the first 8-16 h of exposure to concentrations of CPZ below the MIC. During this period of transient susceptibility, the distribution of ribosomes was markedly altered in a concentration dependent manner; the rough cell wall was transformed into a smooth form. The protein composition of the outer cell wall of 55 kDa was markedly decreased, whilst there was an increased number of high molecular weight proteins. After 16 h of exposure to sub-MIC levels of CPZ, the inhibitory effect of the drug was no longer apparent whereas the effects noted on the cell wall were retained. These Salmonella were, as the control, agglutinated by O antigen specific antibody. Whereas agglutination of the control Salmonella was blocked by the presence of CPZ at concentrations that induced the cell-wall effects, agglutination of CPZ exposed-Salmonella for periods in excess of 16 h was not blocked by any concentration of CPZ. These results suggested that eventual resistance to CPZ was dependent upon changes induced by CPZ at the cell wall level. The results also suggested that the CPZ binds to the 55 kDa protein and that such binding interfered with the recognition of the O antigen by antibody.

Phenothiazines: an alternative to conventional therapy for the initial management of suspected multidrug resistant tuberculosis. A call for studies

Increased frequency of multidrug resistant strains of Mycobacterium tuberculosis results from inappropriate treatment and lack of patient compliance. The Center for Disease Control/American Thoracic Society (CDC/ATS) guidelines issued for the management of newly diagnosed cases of tuberculosis (TB) will not be totally effective regardless of adherence to the guidelines and patient cooperation. The long interim period between the diagnosis of TB and confirmation of antibiotic susceptibility contributes to the infection rate. Consequently, the use of an adjuvant that is known to inhibit all encountered multidrug resistant strains of M. tuberculosis may be helpful until antibiotic susceptibility is known. Phenothiazines such as chlorpromazine, methdilazine and thioridazine are effective against strains of M. tuberculosis in vitro and in vivo. It is recommended that studies be designed and conducted for the purpose of managing new cases of TB that emanate from areas known to harbour multidrug resistant strains of M. tuberculosis, with phenothiazines as adjuvants to the regimen recommended by the CDC/ATS guidelines until antibiotic susceptibility is defined. Because the normal maximum period for obtaining conventional antibiotic susceptibility results is less than 7 or 8 weeks, the probability of serious side effects from the use of a phenothiazine is remote.

Interaction between antibiotics and non-conventional antibiotics on bacteria

The individual activity of antibiotics such as ampicillin, tetracycline, erythromycin and gentamicin in combination with compounds known to modify bacterial resistance to given antibiotics was studied using the checkerboard method. The combination of promethazine with either ampicillin, tetracycline or erythromycin or the combination of methylene blue and erythromycin produced significant synergistic activity against Escherichia coli. Verapamil, however, in combination with ampicillin reduced the activity of ampicillin against E. coli. Combinations of clomipramine with either tetracycline or erythromycin, promethazine and erythromycin or verapamil and ampicillin were synergistic against Staphylococcus epidermidis that was resistant to these antibiotics. The only synergy against Pseudomonas aeruginosa was shown by the combination of methylene blue and gentamicin.

The potential management of resistant infections with non-antibiotics

The antimicrobial activity of synthetic, non-chemotherapeutic compounds, such as the phenothiazine, methylene blue, has been known since the time of Ehrlich (1854-1915). In this context the term 'non-antibiotics' is taken to include a variety of compounds which are employed in the management of pathological conditions of a non-infectious aetiology, but which modify cell permeability and have been shown to exhibit broad-spectrum antimicrobial activity. The antimicrobial properties of compounds such as phenothiazines, as well as those of other neurotropic compounds, have only been investigated sporadically, and their application to management of microbial infections has not been evaluated. A review of the literature, coupled with a number of more recent investigations, suggests that some of these and other membrane-active compounds enhance the activity of conventional antibiotics, eliminate natural resistance to specific antibiotics (reversal of resistance) and exhibit strong activity against multi-drug resistant forms of Mycobacterium tuberculosis. Thus non-antibiotics may have a significant role in the management of certain bacterial infections.

Inhibition of the respiration of multi-drug resistant clinical isolates of Mycobacterium tuberculosis by thioridazine: potential use for initial therapy of freshly diagnosed tuberculosis

Chlorpromazine and thioridazine are phenothiazines employed in the treatment of psychosis. These agents inhibited the respiration of clinical isolates of Mycobacterium tuberculosis resistant to streptomycin, rifampin, isoniazid, ethambutol and/or pyrazinamid, all first line drugs. Since any adverse reaction to thioridazine is generally less severe than to chlorpromazine, the possibility is attractive that thioridazine may have a potential in the initial management of patients with newly diagnosed tuberculosis with an as yet undetermined antibiotic susceptibility profile.

Predictive value of blood cultures

The rising incidence of immunocompromised-patient infections caused by bacteria that are normally nonvirulent and indigenous to normal flora has focused attention on the contamination rate of blood cultures. This contamination is usually a consequence of the mode of collection or processing within the laboratory.

The contamination rates of blood cultures usually are reported to a hospital's quality assurance component and to the medical staff. In addition, the identification of organisms isolated from blood cultures is reported to the physician, regardless of whether the organism isolated is a contaminant or the infectious agent. Consequently, reporting positive blood cultures that reflect contamination in certain cases may trigger some physicians to initiate prompt antibacterial therapy. The contamination rate of the blood culture has, therefore, a serious impact on medical consequences as well as on resource use.

Effects of chlorpromazine on the cell envelope proteins of Escherichia coli

Chlorpromazine (CPZ), at a concentration of 60 micrograms/ml of medium completely inhibited the replication of Escherichia coli. At concentrations below this MIC, CPZ caused transient induction of filamentation, such that by the end of 5 h, all of the cells were filaments, and by the end of 24 h, only rod-shaped E. coli were present. The reversion to normal morphology in the presence of CPZ was not due to either the degradation of CPZ or the selection of CPZ-resistant mutants. The electrophoretic pattern of proteins extracted from isolated cell envelopes of CPZ-induced filaments as well as from E. coli that reverted to normal morphology was distinctly different from that of the controls.