Dietary omega-3 polyunsaturated fatty acid does not influence the intestinal microbial communities of broiler chickens.

The capacity for n-3 polyunsaturated fatty acids (PUFA) to improve broiler chicken growth, influence the intestinal microbial communities, and modify the PUFA content of meat was studied. Male Cobb 500 chickens were fed 1 of 4 diets from hatch: control (standard diet with no additives), ZnB (standard diet with added antibiotics), 2% SALmate (standard diet with 2% SALmate, which is composed of 42% fish oil and 58% starch), and 5% SALmate (standard diet with 5% SALmate). A 7-d energy metabolism study was conducted between d 15 and 22 posthatch. Birds were killed at d 25 and intestinal samples were collected to assess microbial communities by terminal restriction fragment length polymorphism and Lactobacillus PCR-denaturing gradient gel electrophoresis. Diet did not affect BW, feed intake, feed conversion, or ileal digestible energy (P > 0.05). Apparent ME was greater in ZnB-fed birds compared with all other diets (P < 0.05). Breast tissue levels of eicosapentaenoic acid, docosahexaenoic acid, docosapentaenoic acid, and total n-3 PUFA were elevated significantly in 2% SALmate- and 5% SALmate-fed chickens compared with control and ZnB diets (P < 0.05). No significant differences in overall microbial communities were observed in the ileum or cecum as assessed by terminal RFLP (P > 0.05). Birds fed 2% SALmate had a significantly different cecal Lactobacillus species profile compared with birds fed the control diet (P < 0.05); however, no differences were observed in birds fed 5% SALmate compared with birds fed all other diets. In addition to the expected increase in breast tissue n-3 fatty acid levels, a low level of dietary n-3 PUFA also altered the intestinal Lactobacillus species profiles. However, n-3 PUFA supplementation did not alter the overall microbial communities or broiler performance.

Predominance and genetic diversity of community- and hospital-acquired CTX-M extended-spectrum beta-lactamases in York, UK.

OBJECTIVES: This study was conducted to detect the presence of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae within the faecal flora of both community- and hospital-based patients in York and to characterize the bla(TEM), bla(SHV) and bla(CTX-M) genes present in these isolates. METHODS: One thousand faeces samples were collected and screened at York Hospital during October-December 2003. Ninety-five non-duplicate Enterobacteriaceae isolates resistant to third-generation cephalosporins were recovered; 22 isolates were selected for further study on the basis of a positive double disc diffusion test for ESBL production. Antibiotic susceptibility testing was performed to a range of antibiotics. The TEM, SHV and CTX-M genes were detected by PCR and the DNA sequenced. RESULTS: The distribution of ESBL-positive isolates from the hospital and community was 1.4:1. These included nine Escherichia coli, seven Enterobacter cloacae, four Citrobacter freundii and a single isolate each of Klebsiella spp. and Salmonella spp. A total of 17 isolates contained bla(CTX-M) (five bla(CTX-M-15), three bla(CTX-M-14) and nine bla(CTX-M-9)). ISEcp1 was present in isolates expressing CTX-M-14 and -15, but was absent upstream of In60-associated bla(CTX-M-9). E. coli isolates also contained either a bla(TEM-1) or bla(TEM-2), whereas six of the E. cloacae carried bla(SHV-12) and the Klebsiella spp. bla(SHV-36) in addition to bla(CTX-M-9). The single Salmonella spp. carried bla(SHV-12). CONCLUSIONS: The overall prevalence of ESBL in isolates of Enterobacteriaceae from York was 1.9%. ESBL-producing isolates were found in both the community and hospital, with the CTX-M type most common. This is also the first report of an ESBL-producing Salmonella in the UK.

Dissemination of CTX-M type beta-lactamases in Enterobacteriaceae isolates in the People's Republic of China.

Previously there have been a number of reports of extended spectrum beta-lactamase (ESBL) producing isolates of the family Enterobacteriaceae in Asia. We first reported the occurrence of bla(CTX-M) in Guangzhou, China, subsequently there have been reports of bla(CTX-M) from a number of other south Asian countries. Initial surveillance study data suggested that bla(CTX-M) might be widely distributed in China. This study examines the type of bla(CTX-M) occurring in other major population centres in China. Initial disk diffusion method susceptibility testing (NCCLS) selected ESBL producing Escherichia coli and Klebsiella pneumoniae isolates from Beijing and near Wuhan, PRC. After screening in both China and the UK, 13 isolates producing CTX-M ESBLs were identified and studied, 11 also produced TEM-1, and 4 also produced SHV-1. Sequence analysis of the bla(CTX-M) containing isolates revealed these isolates contained two different bla(CTX-M), three with bla(CTX-M-3) and 10 with bla(CTX-M-14). After comparison with other previously published studies in the English language, we conclude that the most prevalent bla(CTX-M) so far reported in Asia are bla(CTX-M-14) and bla(CTX-M-3).

Effects of modulation of tissue activities of DT-diaphorase on the toxicity of 2,3-dimethyl-1,4-naphthoquinone to rats.

The enzyme DT-diaphorase mediates the two-electron reduction of quinones to hydroquinones. It has previously been shown that the toxicity of 2-methyl-1,4-naphthoquinone to rats is decreased by pre-treatment of the animals with compounds that increase tissue levels of this enzyme. In contrast, the severity of the haemolytic anaemia induced in rats by 2-hydroxy-1,4-naphthoquinone was increased in animals with high levels of DT-diaphorase. In the present experiments, the effect of alterations in tissue diaphorase activities on the toxicity of a third naphthoquinone derivative, 2,3-dimethyl-1,4-naphthoquinone, has been investigated. This compound induced severe haemolysis and slight renal tubular necrosis in control rats. Pre-treatment of the animals with BHA, a potent inducer of DT-diaphorase, diminished the severity of the haemolysis induced by this compound and abolished its nephrotoxicity. Pre-treatment with dicoumarol, an inhibitor of this enzyme, caused only a slight increase in the haemolysis induced by 2,3-dimethyl-1,4-naphthoquinone, but provoked a massive increase in its nephrotoxicity. Modulation of DT-diaphorase activity in animals may therefore not only alter the severity of naphthoquinone toxicity, but also cause pronounced changes in the site of toxic action of these substances. The factors that may control whether induction of DT-diaphorase in animals will decrease or increase naphthoquinone toxicity are discussed.

Relative activities of organosulfur compounds derived from onions and garlic in increasing tissue activities of quinone reductase and glutathione transferase in rat tissues.

There is evidence that onions and garlic protect against cancer in humans. It has been suggested that this effect is due to the organosulfur compounds in these vegetables and that these substances act through induction of phase II detoxification enzymes. In the present studies, we have compared the ability of diallyl sulfide, dially disulfide, and diallyl trisulfide, compounds that are derived from garlic, to increase the activity of the phase II enzymes quinone reductase and glutathione transferase in a variety of rat tissues. We have also examined the onion-derived substances, dipropyl sulfide, dipropyl disulfide, dipropenyl sulfide, and dipropenyl disulfide, under identical conditions. Diallyl trisulfide and diallyl disulfide were potent inducers of the phase II enzymes. Dipropenyl disulfide was much less active, while little effect on enzyme activity was seen in animals dosed with dipropyl disulfide. Diallyl sulfide and dipropyl sulfide were weak inducers of quinone reductase and glutathione transferase, but dipropenyl sulfide was very active, with an effect similar to that of diallyl disulfide. It is possible that diallyl disulfide and diallyl trisulfide are important in the anticancer action of garlic, while dipropenyl sulfide could be involved in the beneficial action of onions.

Induction of quinone reductase and glutathione transferase in rat tissues by juglone and plumbagin.

The ability of the naturally-occurring naphthoquinone derivatives, juglone and plumbagin, to increase tissue activities of the Phase II detoxification enzymes quinone reductase (QR) and glutathione transferase (GT) has been investigated in rats. Groups of female Sprague-Dawley rats were dosed by oral intubation on 5 consecutive days with either juglone or plumbagin at 12.5, 25, 50, 75, 100 or 125 mumoles/kg/day. The animals were then killed and the activities of QR and GT determined in tissue homogenates. The naphthoquinone derivatives had no significant effect on enzyme activities in the liver, spleen, heart, lung or urinary bladder. Increases in the activities of one or both enzymes were recorded, however, in the caecum, kidney, forestomach, duodenum, colon, glandular stomach and jejunum. The possibility that induction of Phase II enzymes could contribute to the previously-reported ability of juglone and plumbagin to protect animals against chemically-induced intestinal neoplasia is discussed.

Clinician attributions associated with the diagnosis of schizophrenia in African American and non-African American patients.

The authors examined the schizophrenia diagnosis in 292 psychiatric inpatients in a largely African American community. Clinicians completed a free-response questionnaire that described their diagnostic decisions. Psychotic symptoms such as hallucinations, which were attributed to African American and non-African American patients at different rates, did not necessarily correspond to differences in diagnostic rates. Rather, symptoms not differentially attributed between groups often corresponded with higher rates of schizophrenia for African American patients. Attributions of negative symptoms showed the largest differences between African American and non-African American patients in rates of schizophrenia diagnosis; thought disorder equalized rates of the diagnosis between the 2 groups of patients. Logistic regression analyses suggested that different aggregate decision models were applied to patients of differing race.

Low doses of diallyl disulfide, a compound derived from garlic, increase tissue activities of quinone reductase and glutathione transferase in the gastrointestinal tract of the rat.

Diallyl disulfide (DADS), a substance that is formed from the organosulfur compounds present in garlic, is known to increase tissue activities of the phase II detoxification enzymes quinone reductase (QR) and glutathione transferase (GT) in animals. In previous experiments, however, high doses of DADS were employed and only a limited range of tissues were examined. In the present studies, increased activities of QR and GT were recorded in the forestomach, glandular stomach, duodenum, jejunum, ileum, cecum, colon, liver, kidneys, spleen, heart, lungs, and urinary bladder of rats given DADS over a wide range of dose levels. Large variations in response were recorded among the different organs, with forestomach, duodenum, and jejunum being the most sensitive to enzyme induction by DADS. In these organs, significant increases in QR activity were observed at a dose of only 0.3 mg/kg/day. Such a dose level is close to that which may be achieved through human consumption of garlic, suggesting that induction of phase II enzymes may contribute to the protection that is afforded by this vegetable against cancer of the gastrointestinal tract in humans.

Effect of butylated hydroxyanisole on the toxicity of 2-hydroxy-1,4-naphthoquinone to rats.

It has previously been shown that rats pre-treated with butylated hydroxyanisole (BHA), a well-known inducer of the enzyme DT-diaphorase, are protected against the harmful effects of 2-methyl-1,4-naphthoquinone. This is consistent with a role for diaphorase in the detoxification of this quinone, but it is not known if increased tissue levels of this enzyme give protection against other naphthoquinone derivatives. In the present study, rats were dosed with BHA and then challenged with a toxic dose of 2-hydroxy-1,4-naphthoquinone, a substance that causes haemolytic anaemia and renal damage in vivo. Pre-treatment with BHA had no effect upon the nephrotoxicity of 2-hydroxy-1,4-naphthoquinone, but the severity of the haemolysis induced by this compound was increased in the animals given BHA. DT-Diaphorase is known to promote the redox cycling of 2-hydroxy-1,4-naphthoquinone in vitro, with concomitant formation of 'active oxygen' species. The results of the present experiment suggest that activation of 2-hydroxy-1,4-naphthoquinone by DT-diaphorase may also occur in vivo and show that increased tissue levels of DT-diaphorase are not always associated with naphthoquinone detoxification.

Effect of inducers of DT-diaphorase on the toxicity of 2-methyl- and 2-hydroxy-1,4-naphthoquinone to rats.

It has previously been shown that rats pre-treated with butylated hydroxyanisole (BHA), a well-known inducer of the enzyme DT-diaphorase, are protected against the toxic effects of 2-methyl-1,4-naphthoquinone but are made more susceptible to the harmful action of 2-hydroxy-1,4-naphthoquinone. In the present experiments, the effects of BHA have been compared with those of other inducers of DT-diaphorase. Rats were dosed with BHA, butylated hydroxytoluene (BHT), ethoxyquin (EQ), dimethyl fumarate (DMF) or disulfiram (DIS) and then challenged with a toxic dose of the naphthoquinones. All the inducers protected against the haemolytic anaemia induced by 2-methyl-1,4-naphthoquinone in rats, with BHA, BHT and EQ being somewhat more effective than DMF and DIS. A similar order of activity was recorded in the relative ability of these substances to increase hepatic activities of DT-diaphorase, consistent with a role for this enzyme in facilitating conjugation and excretion of this naphthoquinone. In contrast, all the compounds increased the haemolytic activity of 2-hydroxy-1,4-naphthoquinone. DMF and DIS were significantly more effective in this regard than BHA, BHT and EQ. DMF and DIS also caused a much greater increase in levels of DT-diaphorase in the intestine, suggesting that 2-hydroxy-1,4-naphthoquinone is activated by this enzyme in the gut. BHA, BHT and EQ had no effect on the nephrotoxicity of 2-hydroxy-1,4-naphthoquinone, but the severity of the renal lesions was decreased in rats pre-treated with DMF and DIS. The results of the present experiments show that modulation of tissue levels of DT-diaphorase may not only alter the severity of naphthoquinone toxicity in vivo, but may also change the relative toxicity of these substances to different target organs.

Psychiatric diagnosis of African Americans: diagnostic divergence in clinician-structured and semistructured interviewing conditions.

This study is a primary data collection that varied patient race and diagnosis and used two diagnostic interviewing conditions: one clinician-structured (phase one) and the other a semi-structured diagnostic instrument (phase two). Four basic research questions are addressed: What is the relationship between race and the hospital diagnosis? How is race related to diagnosis in both research interviewing conditions? Why does diagnostic concordance between the hospital diagnosis and the research diagnosis vary by research interviewing condition? Is diagnostic concordance between the hospital and research diagnosis influenced by patient race? A total of 291 patients completed an interview during phase one, while 665 patients completed an interview during phase two. Blacks were more likely to receive a hospital diagnosis of schizophrenia and less likely to be diagnosed with mood disorder. Patient race was similarly related to the research diagnoses produced in the clinician-structured research condition (phase one). Although less pronounced, a higher percentage of African Americans than whites received a diagnosis of schizophrenia using the semi-structured DSM-III-R Symptom Checklist (phase two). The black-white distribution for mood disorders showed that whites were more likely than blacks to be diagnosed with mood disorder.

Effects of butylated hydroxyanisole and dicoumarol on the toxicity of menadione to rats.

The enzyme DT-diaphorase catalyses the 2-electron reduction of quinones. This reaction may facilitate the detoxification of such compounds, since the hydroquinone so formed can be converted into non-toxic conjugates. There is evidence for the involvement of DT-diaphorase in the detoxification of menadione (2-methyl-1,4-naphthoquinone) in a wide range of cells and tissues in vitro, but no information is available on the possible influence of this enzyme on the harmful effects of menadione in vivo. In animals, menadione is selectively toxic to erythrocytes, causing haemolytic anaemia. In the present study, rats were treated with dicoumarol, an inhibitor of DT-diaphorase, or butylated hydroxyanisole (BHA), a substance that increases the activity of this enzyme in vivo. They were then challenged with a toxic dose of menadione. Dicoumarol increased the severity of menadione-induced haemolytic anaemia while BHA decreased it, consistent with a role for DT-diaphorase in the detoxification of menadione in vivo, as previously described in vitro.

Role of Schizosaccharomyces pombe RecQ homolog, recombination, and checkpoint genes in UV damage tolerance.

The cellular responses to DNA damage are complex and include direct DNA repair pathways that remove the damage and indirect damage responses which allow cells to survive DNA damage that has not been, or cannot be, removed. We have identified the gene mutated in the rad12.502 strain as a Schizosaccharomyces pombe recQ homolog. The same gene (designated rqh1) is also mutated in the hus2.22 mutant. We show that Rqhl is involved in a DNA damage survival mechanism which prevents cell death when UV-induced DNA damage cannot be removed. This pathway also requires the correct functioning of the recombination machinery and the six checkpoint rad gene products plus the Cdsl kinase. Our data suggest that Rqh1 operates during S phase as part of a mechanism which prevents DNA damage causing cell lethality. This process may involve the bypass of DNA damage sites by the replication fork. Finally, in contrast with the reported literature, we do not find that rqh1 (rad12) mutant cells are defective in UV dimer endonuclease activity.

Recruitment and retention of African American patients for clinical research: an exploration of response rates in an urban psychiatric hospital.

The issues related to recruiting African American psychiatric inpatients are discussed in the context of a study on the influence of ethnicity on psychiatric diagnosis. Ethnically diverse psychiatric residents interviewed 960 Black and White inpatients in 2 urban psychiatric hospitals. Despite the obstacles cited in the literature about recruiting and retaining African Americans into research, 78% of this sample were African American. In addition, interview completion and refusal rates did not differ by patient ethnicity. Results suggest that matching interviewer and patient ethnicity did not influence African Americans' likelihood of participating in or of refusing an interview. This article summarizes a number of guidelines that others may find useful in conducting clinical research with African Americans, ranging from the formation of academic-public liaisons to interviewer training.

Toxicity of 2,3-dialkyl-1,4-naphthoquinones in rats: comparison with cytotoxicity in vitro.

The short-term toxicities of 2-methyl-1,4-naphthoquinone and a series of 2,3-dialkyl-1,4-naphthoquinones have been determined in rats and compared with their ability to cause oxidative damage to erythrocytes in vitro. In accord with previous results, 2-methyl-1,4-naphthoquinone caused marked oxidative damage to erythrocytes in vitro and haemolytic anaemia in rats. The dialkylnaphthoquinones were also haemolytic agents in vivo, with 2,3-dimethyl-1,4-naphthoquinone being particularly active. Unlike the monoalkyl derivative, however, these substances caused little or no damage to red cells in vitro. The in vivo toxicity of dialkylnaphthoquinones cannot, therefore, be predicted on the basis of in vitro cytotoxicity tests.

Comparative toxicity of 2-hydroxy-3-alkyl-1,4-naphthoquinones in rats.

2-Hydroxy-1,4-naphthoquinone has previously been shown to cause severe haemolytic anaemia and renal tubular necrosis in animals. In order to establish if such toxic effects are common to other 2-hydroxynaphthoquinone derivatives, the short-term toxicity of a number of 2-hydroxy-3-alkyl-1,4-naphthoquinones has been compared in rats. 2-Hydroxy-3-methyl, 2-hydroxy-3-ethyl- and 2-hydroxy-3-propyl-1,4-naphthoquinone were found to cause both haemolysis and renal damage, although the severity of the changes provoked by these substances was much lower than those induced by the parent compound at an equivalent dose-level. Furthermore, the toxicity of the hydroxy-alkylnaphthoquinones decreased with increasing size of the alkyl substituent and no toxic changes were recorded in animals dosed with 2-hydroxy-3-butyl- or 2-hydroxy-3-pentyl-1,4-naphthoquinone. The relationship between the in vivo effects of these substances and previously reported data on their in vitro cytotoxicity is discussed in relation to the mechanism of toxicity of these and other naphthoquinone derivatives.

Comparative toxicity of alkyl-1,4-naphthoquinones in rats: relationship to free radical production in vitro.

2-Methyl-1,4-naphthoquinone causes haemolysis in vivo. This toxic effect is believed to result from oxidative damage to erythrocytes by "active oxygen" species formed via one-electron reduction of the naphthoquinone by oxyhaemoglobin. In the present investigation, seven 2-alkyl-1,4-naphtoquinones have been studied with regard to their haemolytic activity in rats, their ability to cause oxidative damage in erythrocytes in vitro, and their reactivity toward oxyhaemoglobin. A close correlation was observed between the in vivo and in vitro parameters, suggesting that the proposed mechanism of toxicity of 2-methyl-1,4-naphthoquinone is correct and is also applicable to other alkylnaphthoquinones.

A comparison of polyglycolic acid and catgut sutures in rat colonic anastomoses.

Standard colonic wounds were closed in 44 rats by either polyglycolic acid or catgut sutures. Seven days later portions of the colonic wounds were measured for tensile strength and examined histologically. There was no difference in the mortality, strength of the anastomosis or the amount of inflammation induced by either of the suture materials used.