Adverse events to antituberculosis therapy: influence of HIV and antiretroviral drugs

This study investigated whether serious adverse events (SAEs) during antituberculosis therapy occur more frequently in HIV co-infected patients in a South African population. A retrospective analysis examined incidences of hepatotoxicity, peripheral neuropathy, severe arthralgia, persistent vomiting and severe rash in 400 patients treated for tuberculosis in a community clinic. A total of 141 patients were co-infected with HIV, among whom only 16.3% were receiving antiretrovirals. Details of SAEs were ascertainable in 331/400 patients, and occurred in 26.7% of HIV-infected and 13.3% of HIV-uninfected individuals ( P = 0.003). The excess was attributable to increased peripheral neuropathy (8.3% and 1.9%, respectively, P = 0.009) and persistent vomiting (13.3% and 3.3%, P = 0.001). SAE occurrence was not related to antiretroviral use, although median CD4 counts were lower in those experiencing side-effects (130 and 259 cells/µL, P = 0.008). The treatment completion did not differ significantly between the two groups (76.6% and 84.2%, P = 0.08).

The diagnostic value of digital rectal examination in primary care for palpable rectal tumour

BACKGROUND

Accurate digital rectal examination (DRE) enables the early diagnosis of palpable rectal tumour. We aimed at evaluating the diagnostic value of DRE performed by general practitioners (GPs), with respect to detecting the presence of a palpable rectal tumour.

METHOD

All patients diagnosed to have a palpable rectal tumour via a 14-day cancer referral system between May and December 2006 were identified from the colorectal database. Patients referred by GPs during the same period as having a palpable rectal tumour were also identified by reviewing the 14-day cancer referrals. Sensitivity, specificity, positive and negative predictive value of a DRE in primary care were calculated by using these data.

RESULTS

Between May and December 2006, 1069 patients were referred to the University Hospital of North Staffordshire to the 14-day urgent colorectal cancer referral service. Of these, 108 patients were referred as having a 'palpable rectal tumour'. Only 32 of the 108 were found to have a rectal lesion on examination in the hospital. Ten tumours were missed by GPs' DREs.

CONCLUSION

Digital rectal examination in primary care for palpable rectal tumour has a sensitivity of 0.762, specificity of 0.917, positive predictive value of 0.296 and negative predictive value of 0.988. It is an inaccurate procedure and a poor predictor for palpable rectal tumour.

Rates of tuberculosis transmission to children and adolescents in a community with a high prevalence of HIV infection among adults

BACKGROUND

Tuberculin skin test surveys are routinely used to test for tuberculosis (TB) infection in communities, but there are few data from tuberculin skin test surveys from countries in which both TB and human immunodeficiency virus (HIV) infection are prevalent.

METHODS

We conducted a tuberculin skin test survey among 831 school-going children aged 5-17 years in a community that was experiencing an increase in the prevalence of TB and HIV infection. Responses to purified protein derivative RT23 were measured 3 days after the test was administered to determine tuberculin skin test results.

RESULTS

The prevalence of tuberculin skin test results positive for TB (i.e., an induration >or=10 mm in diameter in response to the skin test) ranged from 26.2% among children aged 5-8 years to 52.5% among children aged 14-17 years. The overall annual risk of infection was 4.1% using a 10-mm cutoff and 2.0% using a 17.4-mm cutoff. Annual risks of infection were constant across age groups. This is consistent with the finding that TB incidence remained the same in children (P= .48) from 1999 through 2005, although total TB incidence and adult TB (determined by sputum smear test) incidence increased in this community during the same period (P<.001).

CONCLUSIONS

The annual risk of infection is high in the community. It appears that HIV infection-associated TB is not a major influence on the annual risk of infection and that TB transmission from adults to children may be associated with a subset of TB cases in the community. An improved understanding of TB transmission patterns is urgently needed help the implementation of novel strategies for reducing the annual risk of infection in this setting.

The influence of water quality on the toxicity and degradation of juglone (5-hydroxy 1,4-naphthoquinone)

This study was part of a broader investigation of low molecular weight quinones under consideration as biocides for the control of aquatic nuisance species (ANS). Preliminary investigations identified the 2-ring naphthoquinones as broad spectrum biocides controlling a wide range of aquatic organisms. All biocides were relatively short-lived in saline waters, with half-lives between 5 and 30h. Juglone (5-hydroxy 1,4-naphthoquinone) and plumbagin (5-hydroxy-2-methyl-1,4- naphthoquinone) showed the greatest toxicity against most aquatic organisms. These qualities formed the basis for a patent focusing on these two compounds as biocides for ANS control, with juglone identified as the more cost-effective of the two. Although juglone has been extensively studied as a plant toxin and reducing agent, remarkably little information exists on its use as an aquatic biocide. We describe the toxicity of juglone over the range of water quality parameters likely to be encountered in ballast water, a major vector for ANS. Tests indicated that its molecular stability was enhanced in freshwater and particularly under neutral to acid conditions. This was supported by results of bioassays on the freshwater cladoceran Daphnia magna that indicated enhanced juglone toxicity at pHs of < or =6.7. A low octanol:water partition coefficient for juglone indicated little capacity for these compounds to be adsorbed by suspended particulates and for bioaccumulation. These properties together with their relatively rapid degradation (t1/2 < or =30h), particularly in the marine environment, indicated a low the risk of residual toxicity associated with the release of juglone-treated water.

Adsorption and absorption of polycyclic aromatic hydrocarbons to rice roots

Rice roots and surrounding air, soil and water samples were collected for polycyclic aromatic hydrocarbon (PAH) analysis. The rice roots were separated into lateral roots and nodal roots, and the PAH concentration in the former was found to be higher than that in the latter. In addition, root physiological characteristics including root biotic mass, root lipid content and specific surface area are also discussed. When normalizing the total, adsorption and absorption PAH fractions on a dry root weight basis to root biomass, root lipid, and surface area bases respectively, the differences between PAHs in the two types of roots diminished by 2 to 3 times on average. Results from sequential extraction indicated that PAHs were more easily absorbed by interior rice roots than adsorbed on the surface. In addition, more than 60% of total PAHs accumulated in root tissue for both lateral and nodal roots. However, the results were highly related to the solvent used, extraction time and methodology. Correlation analysis between bioconcentration factors (root over environment) and K(OA), K(OW) showed water to be more significant for PAH adsorption in rice roots than other environmental media.

Adsorption and absorption of dichlorodiphenyltrichloroethane (DDT) and metabolites (DDD and DDE) by rice roots

A three-step sequential extraction procedure was applied to measure the concentrations of dichlorodiphenyltrichloroethane (DDT) on rice root surface and in root tissues collected from two sites in Tianjin. Bulk and rhizosphere soils were also analyzed. The measured DDXs in the rhizosphere soils were significantly higher than those in the bulk soils. On average, p,p'-DDT, p,p'-DDD, and p,p'-DDE in the soil accounted for 38%, 47% and 15% of the total. For total DDXs, approximately one third remained on the outer surface of the roots. The partition of DDXs between rhizosphere soil and root surface depend on contaminant affinity to soil organic matter, soil organic matter content and root specific area. A case specific equation was developed to quantitatively describe the partition of DDXs between soil and root surface.

Screening of natural product biocides for control of non-indigenous species

Several benzo-, naphtho- and anthraquinones were tested for their efficacy as biocides in controlling aquatic nuisance species in ships' ballast water. A requirement of this application was broad spectrum aquatic toxicity, coupled with a relatively rapid rate of degradation, in order to comply with coastal discharge requirements. Compounds were screened using a suite of toxicity bioassays designed to establish their relative toxicity to an array of planktonic organisms including larval bivalves Dreissena and Crassostrea, various developmental stages of the estuarine copepod Eurytemora affinis, brine shrimp larvae (Artemia salina), the freshwater invasive water flea Bythotrephes, larval sheepshead minnows CCyprinodon variegates) and two unicellular algal genera Isochrysis and Neochloris.. The majority of the data were recorded as the lowest concentration of the test compound resulting in complete mortality or inactivation of test organisms (LC ,m). The naphthoquinones juglone, plumbagin, menadione and naphthazarin showed the highest toxicity to the broadest range of organisms, often at levels much less than 1 mg l(-1), and most of the attention was focused on this group. While plumbagin and juglone appeared overall to be the most toxic compounds, it was concluded that menadione was probably the most cost-effective candidate compound for shipboard use for controlling invasive species in ballast water, particularly in view of the large volumes of water that would require treatment.

Naphthoquinones as broad spectrum biocides for treatment of ship's ballast water: toxicity to phytoplankton and bacteria

Current UN International Maritime Organization legislation mandates the phased introduction of ballast water treatment technologies capable of complying with rigorous standards related to removal of waterborne organisms. Doubts concerning mechanical treatments at very high ballasting rates have renewed interest in chemical treatment for very large vessels. High removal rates for biota require broad spectrum biocides that are safe to transport and handle and pose no corrosion problems for ships' structure. The current study focuses on the naphthoquinone group of compounds and extends a previously reported set of screening bioassays with an investigation of the toxicity of four naphthoquinones to select protists and prokaryotes, representative of typical ballast water organisms. Vegetative dinoflagellate cysts exposed to 2.0 mg/L of the naphthoquinones juglone, plumbagin, menadione and naphthazarin showed varying degrees of chloroplast destruction, with menadione demonstrating the most potency. Laboratory and mesocosm exposures of various phytoplankton genera to menadione showed toxicity at 1.0 mg/L. Juglone demonstrated the most bactericidal activity as judged by a Deltatox assay (Vibrio fischeri) and by acridine orange counts of natural bacterial populations.

Exposure of traffic police to Polycyclic aromatic hydrocarbons in Beijing, China

Exposure of on-duty traffic police in Beijing to polycyclic aromatic hydrocarbons (PAHs) was investigated during the summer, 2004 using a personal sampling technique in measuring both particulate and gaseous phase PAHs. The results were then compared with those from two control sites away from the street. Exposure levels to gaseous and particulate PAHs for the traffic police were found to be 1525 +/- 759 ngm(-3) and 148 +/- 118 ngm(-3), respectively, representing 2-2.5 times higher levels than those at the control sites. The daily inhalation exposure of the police was estimated to be 277 ngkg(-1)d(-1). Most of the PAHs exposure came from the vapor phase, particularly NAP, FLO and PHE. Based on calculated PAH diagnostic ratios, the major source of PAHs exposure was from vehicle exhaust. The effects of temperature, humidity and atmospheric stability on exposure levels are also discussed.

Short-term dynamic change of gill copper in common carp, Cyprinus carpio, evaluated by a sequential extraction

Dynamic changes in Cu speciation and its binding to fish gills were investigated by exposing common carp (Cyprinus carpio) to a 1 mg/1 Cu solution for 7 hours. Cu speciation in the bulk solution and fish gill microenvironment was calculated using general chemical equilibrium modeling. A sequential extraction procedure using distilled water, magnesium dichloride (1.0 mol/1), and acetic acid (10%) was used to characterize the Cu associated with the fish gills. Cu residual in the gill tissue was measured after the sequential extraction. Changes in total Cu concentration, pH, and dissolved organic carbon (Doc) in the bulk solution were recorded during the experimental period and calculated for the fish gill microenvironment. Cu-hydroxide species and Cu2 were dominant Cu species in both bulk solution and the fish gill microenvironment, whereas increased Cu-mucus was found in the fish gill microenvironment. DOC in the exposure medium, assumed to arise from mucus release, also increased and complexed Cu in solution. Forty-three percent of the Cu associated with the gills was readily water extractable, with an additional 22% exchangeable with Mg2+ or protons. Only 35% of the Cu accumulated within the gill tissues. The binding of Cu to the fish gills reached apparent equilibrium after 3 hours of exposure. Furthermore, the amount of water-extractable Cu within the gills showed significant correlation to the concentration of Cu predicted to be complexed with calculated free mucus in the gill microenvironment.

Monitoring program for mycotoxin contamination in Uruguayan food and feeds

A pilot study for monitoring mycotoxin contamination in food and feeds was implemented by the Technological Laboratory of Uruguay (LATU) with the technical assistance of the Food and Agriculture Organization of the United Nations (FAO). The scope of the study was to determine the potential hazard posed by priority food-contaminant and feed-contaminant combinations. The choice of foods and contaminants to be monitored was based on the importance of the food in the total diet, the economic importance of the product and the potential health risk posed by the specific combination. The principal commodities selected were wheat, barley and rice. Also included were com, soy, dairy products, feeds, dried fruits and legumes, oil seeds, cocoa beans and organ meats. Mycotoxins analyzed (TLC/densitometry) were aflatoxins, zearalenone, ochratoxin A, deoxynivalenol (DON) and ergot alkaloids. The survey results (1993-95) showed differences in both incidence and levels of mycotoxin content for the principal commodities. Of all food/feed categories analyzed, feed had the highest values for all mycotoxins. Samples containing DON in levels above 1000 ng/g were found in all groups. Ochratoxin A was not detected in any of the samples. Rice and soy beans were the categories with lowest aflatoxin incidence. Uruguayan regulatory limits for all toxins analyzed were exceeded for wheat, barley and rice in less than 3, 9 and 7% of samples, respectively. The data on actual mycotoxin levels in different foods will help identify sources of contaminations and areas where control measures should be improved, enable better risk assessment by proper estimation of mycotoxin intake, assist in the establishment of tolerances and adequate guidelines, aid in the implementation of a national program and provide economic benefits by improving grain quality.

Polycyclic aromatic hydrocarbons in dustfall in Tianjin, China

Atmospheric dustfall samples from 23 locations in Tianjin, China, were collected and analyzed for 16 polycyclic aromatic hydrocarbons (PAHs) classified by the Environmental Protection Agency as priority pollutants from March 2002 to March 2003. SigmaPAH16 (sum of 16 PAH compounds) concentrations in the dustfall collected during heating season ranged from 2.5 to 85.5 mug/g, while that during the non-heating season varied from 1.0 to 48.2 microg/g dry weight. The dominant components in the heating season included naphthalene, phenanthrene, fluoranthene, and chrysene, while naphthalene, fluorene, phenanthrene, and fluoranthene were dominant during the non-heating season. Compared with the non-heating season, the heating season was characterized by a higher fraction of high-molecular-weight PAHs with four to six rings with exception of the samples from the east industrial area. The east industrial area had more significant correlations between individual PAH compounds, and more discrete triangular components of three-, four-, five- and six-ring PAHs. No significant correlations were observed between the PAHs concentrations and total organic carbon (TOC) in the dustfall samples. The deposition fluxes of sigmaPAH15 (sum of 15 PAHs except naphthalene), sigmaPAH6 (sum of 6 carcinogenic PAHs recommended by IARC) and benzo[a]pyrene (BaP) from atmospheric deposition to the whole area were estimated as 1911, 196, and 53 microg/m2/year, respectively. The deposition rates for PAH compounds in the east industrial area were higher than those in the urban and rural areas. Furthermore, the deposition contribution of PAHs during domestic heating season in winter was not significant relative to the annual inputs.

Prediction of the bioconcentration factor of PCBs in fish using the molecular connectivity index and fragment constant models

Models based on molecular connectivity index (MCI) and fragment constant (FC) method were developed for prediction of the bioconcentration factor (BCF) for polychlorobiphenyls (PCBs) in fish. The mean residuals for the MCI and FC models were 0.195 and 0.223 log units, respectively. The two models were then compared in terms of their mean residuals. In addition to the chlorine atom substitution number, other important structural features exhibiting a significant influence on the BCFs of PCB congeners were discussed and incorporated to the models. These features include the degree of the ortho-substitution, the presence of chlorine pairs in the three- and five- positions, and the crowding of chlorine atoms on the phenyl ring.

Presynaptic dopaminergic properties of differentiated mouse embryonic stem cells

This study characterized the presynaptic dopaminergic properties of neuronally differentiated mouse embryonic stem (ES) cells. Approximately 30% of the ES cells expressed tyrosine hydroxylase (TH) immunoreactivity when co-cultured with PA6 cells. These cultures expressed high affinity, sodium-dependent dopamine uptake as well as depolarization-induced and calcium-dependent dopamine release of this transmitter. These and other important dopaminergic genes found expressed in these cultures by RT-PCR included Nurr1, vesicular monoamine transporter 2 (VMAT2), TH, dopamine transporter (DAT), and glial cell line-derived neurotrophic factor (GDNF) receptors c-Ret and GFRalpha1. These results demonstrate that differentiated ES cells have the presynaptic functions for maintaining dopaminergic homeostasis, which may be essential for their long-term use in restoring CNS levels of this transmitter.

Treatment of atrazine by integrating photocatalytic and biological processes

This research examines the degradation of atrazine by photocatalytic oxidation (PCO) under different experimental conditions. Deisopropylatrazine, deethylatrazine and deethyldeisopropylatrazine were formed as major intermediates based on gas chromatography-mass spectrometry. The reaction mixture was found to be toxic towards two bioassays, i.e. the Microtox and amphipods survival tests even when atrazine was completely degraded by PCO within 2 h under optimized conditions. The results indicate that adding H2O2 could significantly enhance the degradation of atrazine by PCO. Ammeline, ammelide and cyanuric acid (CA) became the major intermediates/products as detected by high performance liquid chromatography from 6th to the 40th h of PCO treatment. After 72 h PCO treatment, only CA was detectable in the reaction mixture. Further degradation of CA was carried out by a newly isolated CA-degrading bacterium, Sphingomonas capsulata. The photochemical pretreatment integrated with microbial degradation lead to the complete degradation and detoxification of atrazine.

Optimization of photocatalytic oxidation of 2,2',3,3'-tetrachlorobiphenyl

Polychlorinated biphenyls (PCBs) are wide spread environmental pollutants. This research focused the optimum physico-chemical conditions under which photocatalytic oxidation (PCO) can be used to degrade 2,2',3,3'-tetrachlorobiphenyl (tetra-CB). Among the optimal physico-chemical conditions studied were UV intensity, hydrogen peroxide (H2O2) and titanium dioxide (TiO2) concentrations, initial pH, and possible reaction intermediates were also determined. The results indicate that the optimal physico-chemical conditions necessary for the degradation of tetra-CB by PCO were UV intensity at 3.16 mW/cm2, 30 mM of H2O2 and 100 mg/l of TiO2. In contrast to the results of PCO studies on other organic compounds, the optimum pH for PCO degradation of tetra-CB was 5.5. The removal efficiency was also higher under acidic conditions than alkaline conditions. Although degradation intermediates such as 1,3-bis(1,1-dimethylethyl)benzene, 2,4-bis(1,1-dimethylethyl)phenol, and 3,5-di-tert-butyl-4-hydroxybenzaldehyde were identified at an early stage in the reaction process, they were not completely degraded even after 7h of PCO reaction.

Residues of hexachlorocyclohexane isomers and their distribution characteristics in soils in the Tianjin area, China

Hexachlorocyclohexane (HCH) has a history of use in China. This paper presents the results of an investigation of HCH residue isomers and their distribution characteristics in soils near Tianjin, China. One hundred eighty-eight soil samples were collected from the Tianjin area. Four HCH isomers-alpha-HCH, beta-HCH, gamma-HCH, and delta-HCH-were detected using gas chromatography for all samples. Concentrations of the sum HCH ranged from 1.3 to 1095 ng g(-1), among which beta-HCH accounted for 52.5%. In addition, residues of HCH within Tianjin's urban areas were found to be higher. No significant differences were found between the residues of HCH in soils from waste irrigation areas and those in other areas. Total organic carbon content was determined to impact the residue levels of HCH in soils, while pH value and clay content were not related to concentrations of HCH. In general, all HCH isomers in soil samples had abnormally high residue levels, possibly the result of continuous use of HCH in this area.

Use of sequential ASE extraction to evaluate the bioavailability of DDT and its metabolites to wheat roots in soils with various organic carbon contents

An accelerated solvent extraction (ASE) procedure using water, n-hexane and a mixture of n-hexane and acetone as solvents in sequence was developed and tested to evaluate the bioavailability of DDT and its metabolites including p,p'-DDT, o,p'-DDT, p,p'-DDE, and p,p'-DDD (SigmaDDTs) to wheat uptake from soils characterized by varied organic carbon contents. Results indicated that the extractability of SigmaDDTs with water was enhanced considerably in the presence of water soluble organic carbon (WSOC), while the amount of SigmaDDTs extracted with n-hexane was negatively correlated to the content of water insoluble organic carbon (WIOC). The interaction between SigmaDDTs and WIOC also reduced the bioavailability of the pesticides to wheat roots during uptake. There was a good positive correlation between the amount of SigmaDDTs extracted by n-hexane and the amount of SigmaDDTs accumulated in wheat roots, suggesting some potential for the use of the n-hexane ASE-extracted fraction as an indicator of SigmaDDTs' bioavailability to plant uptake. As such, the three sequentially extracted fractions may be viewed as representing the mobile, bioavailable, and fixed pools of SigmaDDTs in the soil.

Level and distribution of DDT in surface soils from Tianjin, China

One hundred and eighty eight surface soil samples were collected from the Tianjin area to study the contamination of DDT and its metabolites. Measurements were taken for p,p'-DDE, p,p'-DDD, p,p'-DDT, o,p'-DDE, o,p'-DDD and o,p'-DDT for all samples. The results indicated that p,p'-DDT and p,p'-DDE were the predominant contaminant compounds in the surface soil samples, with mean concentrations of 27.5 and 18.8 ng g(-1) respectively. No significant differences in DDT concentrations were found between the soils from wastewater treated irrigated areas and other areas, suggesting that wastewater irrigation is not an important source of DDT in the area. However, the spatial distribution of soil DDTs levels in the area did correlate well with early direct application rates of pesticides. In addition, both pH level and organic carbon content are also known factors affecting the level of DDT and its metabolites. Although it was assumed that the use of these chemicals was banned in the early 1980s, the current concentration levels appear to be too high to be mere residuals after 20 years degradation.

Is Clinical Otolaryngology publishing patient-centred research?

We asked how patient centred is Clinical Otolaryngology? Using two new models for analysing the patient-centredness of medical literature, three reviewers classified 176 papers (91 articles and 85 abstracts) published in this journal during the year 2000. Patients appeared as clinical subjects in 98 (56%), were interviewed by closed questionnaires in 21 (12%) and open questionnaires in 6 (3%), represented only by demographic details in 40 (23%) and not part of the study in 11 (6%) of papers. Papers were considered to address a biomedical frame of reference in 48 (27%), the patient's frame of reference in 6 (3%), technical aspects of the clinical encounter in 109 (62%) and communicative aspects in 7 (4%), and the setting for the encounter in 6 (3%) of papers. We show that some patient-centred research is published in Clinical Otolaryngology but suggest that it could publish more.

Development of a Stable Chemically Defined Surface for the Culture of Human Keratinocytes under Serum-Free Conditions for Clinical Use

Within the field of tissue engineering there is a need to develop new approaches to achieve effective wound closure in patients with extensive skin loss or chronic ulcers. This article exploits the well-known interdependency of epithelial keratinocytes and stromal fibroblasts in conjunction with plasma surface technology. The aim was to produce a chemically defined surface, which with the aid of a feeder layer of lethally irradiated dermal fibroblasts would improve the attachment and proliferation of the keratinocyte cell from which subconfluent cells can be transferred to wound bed models. Plasma copolymers of acrylic acid/octa-1,7-diene have been prepared and characterized by X-ray photoelectron spectroscopy. The fibroblasts and keratinocytes were cultured on plasma polymer-coated 24-well plates. Cell attachment and proliferation were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide-eluted stain assay (MTT-ESTA) and DNA assay. Attachment and proliferation of both cell types on plasma polymer surfaces were compared with tissue culture plastic and collagen I, plus a negative control of a pure hydrocarbon layer. A pure acrylic acid surface, fabricated at a power of 10 W and containing 9.2% carboxylate groups, was found to promote both fibroblast and keratinocyte attachment and proliferation and permit the serum-free coculture of keratinocytes and irradiated fibroblasts.