Biosynthesis of natural and novel C-glycosylflavones utilising recombinant Oryza sativa C-glycosyltransferase (OsCGT) and Desmodium incanum root proteins.

The rice C-glycosyltransferase (OsCGT) is one of only a small number of characterised plant C-glycosyltransferases (CGT) known. The enzyme C-glucosylates a 2-hydroxyflavanone substrate with UDP-glucose as the sugar donor to produce C-glucosyl-2-hydroxyflavanones. We tested substrate specificity of the enzyme, using synthetic 2-hydroxyflavanones, and showed it has the potential to generate known natural CGFs that have been isolated from rice and also other plants. In addition, we synthesised novel, unnatural 2-hydroxyflavanone substrates to test the B-ring chemical space of substrate accepted by the OsCGT and demonstrated the OsCGT capacity as a synthetic reagent to generate significant quantities of known and novel CGFs. Many B-ring analogues are tolerated within a confined steric limit. Finally the OsCGT was used to generate novel mono-C-glucosyl-2-hydroxyflavanones as putative biosynthetic intermediates to examine the potential of Desmodium incanum biosynthetic CGTs to produce novel di-C-glycosylflavones, compounds implicated in the allelopathic biological activity of Desmodium against parasitic weeds from the Striga genus.

Near-infrared broad-band cavity enhanced absorption spectroscopy using a superluminescent light emitting diode.

A fibre coupled near-infrared superluminescent light emitting diode that emits approximately 10 mW of radiation between 1.62 and 1.7 microm is employed in combination with a broad-band cavity enhanced spectrometer consisting of a linear optical cavity with mirrors of reflectivity approximately 99.98% and either a dispersive near-infrared spectrometer or a Fourier transform interferometer. Results are presented on the absorption of 1,3-butadiene, and sensitivities are achieved of 6.1 x 10(-8) cm(-1) using the dispersive spectrometer in combination with phase-sensitive detection, and 1.5 x 10(-8) cm(-1) using the Fourier transform interferometer (expressed as a minimum detectable absorption coefficient) over several minutes of acquisition time.

Effects of age and food restriction on oxidative DNA damage and antioxidant enzyme activities in the mouse aorta.

In this study, DNA damage in mouse aortic cells was measured using the comet assay. The tail moment of the comet assay in aortic cells obtained from 26-month-old mice fed ad libitum (O-AL) was significantly increased as compared to 6-month-old mice fed ad libitum (Y-AL) after the cells were incubated with formamidopyrimidine-DNA glycosylase (Fpg), which specifically recognizes oxidized purines, endonuclease III (Endo III), which specifically recognizes oxidized pyrimidines, or the combination of Endo III and Fpg. The tail moment in aortic cells obtained from 26-month-old mice fed a food-restricted diet (O-FR) was significantly reduced as compared to O-AL mice after the cells were incubated with the combination of Endo III and Fpg. These results indicate that oxidative DNA lesions, i.e. the Endo III- and Fpg-sensitive sites, increase with age in mouse aortic cells and that FR attenuates the age-related increase in oxidative DNA damage. To determine if the changes in oxidative DNA damage in mouse aortic cells are related to the antioxidant status in these cells, we measured the activities of Cu/Zn-superoxide dismutase (SOD), Mn-SOD, extracellular-SOD, catalase and glutathione peroxidase-1 in the mouse aorta. We observed that the activities of all antioxidant enzymes studied were significantly increased with age and that FR attenuated the age-related increase. These data indicate that the age-related increase and FR-induced decrease in oxidative DNA damage, i.e. the Endo III- and Fpg-sensitive sites, in mouse aortic cells is not due to alteration of the antioxidant defense system.

Does oxidative damage to DNA increase with age?

The levels of 8-oxo-2-deoxyguanosine (oxo8dG) in DNA isolated from tissues of rodents (male F344 rats, male B6D2F1 mice, male C57BL/6 mice, and female C57BL/6 mice) of various ages were measured using sodium iodide to prevent oxidative damage to DNA during DNA isolation. Oxo8dG was measured in nuclear DNA (nDNA) isolated from liver, heart, brain, kidney, skeletal muscle, and spleen and in mitochondrial DNA (mtDNA) isolated from liver. We observed a significant increase in oxo8dG levels in nDNA with age in all tissues and strains of rodents studied. The age-related increase in oxo8dG in nDNA from old mice was shown not to the result of the tissue's reduced ability to remove the oxo8dG lesion. Rather, the increase in oxo8dG levels appears to arise from an age-related increase in the sensitivity of these tissues to oxidative stress. We also observed an age-related increase in oxo8dG in mtDNA isolated from the livers of the rats and mice. Dietary restriction, which is known to retard aging and increase the lifespan of rodents, was shown to significantly reduce the age-related accumulation of oxo8dG levels in nDNA in all tissues of male B6D23F1 mice and in most tissues of male F344 rats. Our study also showed that dietary restriction prevented the age-related increase in oxo8dG levels in mtDNA isolated from the livers of both rats and mice.

[Evaluation of motor and sensory neuroconduction of the median nerve in patients with carpal tunnel syndrome treated with non-coherent light emitted by gallium arsenic diodes]. / Evaluación de la neuroconducción motora y sensitiva del nervio mediano en pacientes portadores de síndrome del túnel del carpo tratados con luz no coherente emitida por diodos de arseniuro de galio.

INTRODUCTION: The treatment selection in the carpal tunnel syndrome according to the damage of the median nerve is important and all of these have adverse effects. A good alternative without undesired reactions is irradiation of the carpal tunnel with not coherent light between 920 and 940 nm emitted by gallium arsenide diodes, resembling the physic and therapeutic laser effects. PATIENTS AND METHODS: Twenty-six female patients with idiopathic middle carpal tunnel syndrome were irradiated 15 minutes daily during three weeks. The median nerve motor and sensitive neuroconduction was studied before and immediately after the treatment. RESULTS: The abnormal neuroconduction variables (latency, amplitude and velocity conduction) did not modify when treatment concluded, in spite of all the patients reported disappearance of pain and numbness in damaged hands. CONCLUSIONS: Not coherent light does not change the fibers functional state explored by conventional neuroconductions techniques. It remains to know if this light produces fine fibers improvement.

A reliable assessment of 8-oxo-2-deoxyguanosine levels in nuclear and mitochondrial DNA using the sodium iodide method to isolate DNA.

A major controversy in the area of DNA biochemistry concerns the actual in vivo levels of oxidative damage in DNA. We show here that 8-oxo-2-deoxyguanosine (oxo8dG) generation during DNA isolation is eliminated using the sodium iodide (NaI) isolation method and that the level of oxo8dG in nuclear DNA (nDNA) is almost one-hundredth of the level obtained using the classical phenol method. We found using NaI that the ratio of oxo8dG/10(5 )deoxyguanosine (dG) in nDNA isolated from mouse tissues ranged from 0.032 +/- 0.002 for liver to 0.015 +/- 0.003 for brain. We observed a significant increase (10-fold) in oxo8dG in nDNA isolated from liver tissue after 2 Gy of gamma-irradiation when NaI was used to isolate DNA. The turnover of oxo8dG in nDNA was rapid, e.g. disappearance of oxo8dG in the mouse liver in vivo after gamma-irradiation had a half-life of 11 min. The levels of oxo8dG in mitochondrial DNA isolated from liver, heart and brain were 6-, 16- and 23-fold higher than nDNA from these tissues. Thus, our results showed that the steady-state levels of oxo8dG in mouse tissues range from 180 to 360 lesions in the nuclear genome and from one to two lesions in 100 mitochondrial genomes.

Integrating behavioral and pharmacological interventions in treating clients with psychiatric disorders and mental retardation.

While the literature on treatment of dually diagnosed individuals continues to grow, few studies have examined the potential interactions between behavioral interventions and pharmacological interventions in treating persons with a developmental disability and a concurrent psychiatric disorder. The current theoretical paper discusses different manners in which psychotropic medications and behavioral interventions can interact, including the potential for facilitative or inhibitory effects of one treatment modality on the other. Possible permutations of these interactions are discussed. Case examples, including objective measures of psychiatric and behavioral symptoms over time, representing possible illustrations of these permutations, are presented. The authors argue that in many cases the potential effect of one treatment procedure on the efficacy of another may be an important consideration in treating dually diagnosed individuals.

[Motor and sensory nerve conduction in patients with carpal tunnel syndrome and diabetic polyneuropathy]. / Neuroconducción motora y sensitiva en pacientes con síndrome del túnel del carpo y polineuropatía diabética.

INTRODUCTION: The combination of carpal tunnel syndrome and diabetic polyneuropathy is common, and it is important to establish the correct diagnosis since carpal tunnel syndrome can be successfully treated by surgery, even in diabetic patients. Both conditions have similar clinical features and the usual neurophysiological investigations show very similar results. OBJECTIVE: To determine the differential diagnosis between carpal tunnel syndrome and diabetic polyneuropathyP. PATIENTS AND METHODS: Sensory and motor neuro-conduction studies were done on the median and ulnar nerves of a group of 30 healthy persons (group A), 30 patients with a history of carpal tunnel syndrome (group B) and 30 patients with diabetes mellitus type I or type II (group C) with diabetic polyneuropathy. The physiological variables in which the greatest differences were seen in the three groups were: the speed of sensory conduction in the palm-third finger segment of the median nerve, distal latency obtained on stimulation of the fourth finger, distal motor latency of the median nerve and distal latency of the sensory potentials obtained by stimulation at the wrist and recorded at the fourth finger. RESULTS AND CONCLUSIONS: With these variables for prediction, carpal tunnel syndrome was detected in 30% of the patients classified initially on clinical grounds as having diabetic polyneuropathy, and 60% of the patients were correctly reclassified after being initially classified on clinical grounds as having carpal tunnel syndrome.

Staff perceptions of sexuality-related problems and behaviors of psychiatrically hospitalized children and adolescents.

Clinical staff at two hospitals serving children and adolescents were surveyed regarding their observations and experiences regarding the sexuality-related behaviors and issues of patients. Results of this descriptive study indicate that staff frequently encounter a wide range of such problems, including the effects sexual abuse, sexually aggressive or inappropriate behavior, lack of knowledge about basic hygiene and sexual development, pregnancy and contraception, high-risk behaviors, and sexually-transmitted diseases, including AIDS. Similarities and differences of the perceptions by staff of these problems are compared across unit types (children's, adolescents, dually-diagnosed, developmentally-disabled). Implications for staff training, clinical policies, and further research are discussed.

Effect of covalent modification on coproporphyrinogen oxidase from chicken red blood cells.

The biosynthesis of heme is a complex multi-step pathway requiring the efforts of eight enzymes. The initial enzymes in the heme biosynthetic pathway have been well characterized in relation to their mechanisms. Coproporphyrinogen oxidase (Copro'gen oxidase) is one of the last three enzymes in the pathway and is one of the least well understood. Copro'gen oxidase converts coproporphyrinogen III to protoporphyrinogen IX via oxidative decarboxylation of the 3- and 8-propionic side chain moieties. To further our understanding of the recognition and binding of substrate, Copro'gen oxidase was partially purified from chicken red blood cell hemolysates then incubated with covalent modifiers of specific amino acids. Incubation with tetranitromethane, p-hydroxyphenylglyoxal, N-acetylimidazole, or trinitrobenzenesulfonic acid resulted in substantial reduction of Copro'gen oxidase activity implying the presence of critical tyrosine, arginine and lysine residues. We conclude that these amino acids play important roles in the enzymic mechanism (for both binding and catalysis) of Copro'gen oxidase.

Juvenile psoriatic arthritis and HLA antigens.

The clinical, laboratory, and radiological features, including histocompatibility typing, of 28 patients with juvenile psoriatic arthritis are reported. The most common presentation was that of psoriasis preceding or occurring simultaneously with arthritis. The most common course of juvenile psoriatic arthritis was to start as an oligoarthritis and progress, usually to polyarthritis. No patients with juvenile psoriatic arthritis had uveitis. Overall, most patients had a good outcome (93% in functional class I and II), though 8/28 (29%) did require disease modifying drugs over a mean period of 8.8 years of follow up. The clinical features of these patients were very similar to those of a group of 158 adult patients with psoriatic arthritis with the same disease duration followed up in the clinic. Although there was an increased prevalence of B17 in both juvenile and adult psoriatic arthritis, juvenile psoriatic arthritis showed increased prevalence of A2, whereas adult psoriatic arthritis showed increased prevalence of B27, Bw39, and Cw6. This HLA association differed from that reported in other forms of juvenile arthritis.

Methods for measuring mutagenicity in urine of rats dosed with [14C]di(2-ethylhexyl)phthalate.

Di(2-ethylhexyl)phthalate (DEHP) is extensively used as a plasticizer for vinyl plastic articles. It has been found to be positive in an NCI rodent bioassay but has generally given negative results in in vitro genotoxicity tests. We therefore decided to test the urine of rats fed [14C]DEHP for mutagenic activity in the Ames Salmonella test. The recovery of radioactivity from the urine of rats dosed with [14C]DEHP was examined by solvent extraction and XAD-2 resin absorption procedures. Both of these procedures were inadequate for quantitative recovery of urinary metabolites required for subsequent mutagenicity testing using the Ames Salmonella/microsome procedure. Recoveries of less than 5% were observed using standard solvent extraction techniques whereas the XAD-2 adsorption technique gave about 67% at high resin/urine ratios. Treatment of the urine with beta-glucuronidase/aryl sulfatase did not affect these recoveries. The direct urine plating procedure represents a viable alternative to the above concentration procedures for this phthalate ester. The effects of L-histidine and the beta-glucuronidase/aryl sulfatase preparation on the background reversion frequencies of the Ames tester strains is discussed.

Bacterial mutagenicity testing of urine from rats dosed with 2-ethylhexanol derived plasticizers.

Di-(2-ethylhexyl)phthalate (DEHP) produced hepatocellular carcinomas in rodents at high doses in a NTP/NCI bioassay. DEHP has not shown evidence of genotoxic activity in in vitro mutagenicity tests. We extended these studies by examining the mutagenicity of urine from rats dosed with DEHP, 2-ethylhexanol (2-EH), and several other 2-EH derived plasticizers, i.e. di-(2-ethylhexyl)adipate (DEHA), di-(2-ethylhexyl)terephthalate (DEHT) and tri-(2-ethylhexyl)trimellitate (TEHT). A modified Ames Salmonella/microsome assay was used to determine mutagenicity. Urine was pooled from male Sprague--Dawley rats dosed daily for 15 days with 2000 mg/kg of each test substance with the exception of 2-EH which was given at 1000 mg/kg. Direct plating procedures were used to determine the presence of mutagens in urine. Urine from rats dosed with 8-hydroxyquinoline was used as a positive control. There was no evidence that mutagenic substances were excreted in the urine by rats dosed with either DEHP, DEHA, DEHT, TEHT or 2-EH as determined in the presence or absence of rat liver microsomes, and with or without treatment with beta-glucuronidase/aryl sulfatase. Our findings indicate that the above test compounds were not converted to urinary metabolites that were mutagenic. These observations provide no evidence for a genotoxic mechanism for DEHP carcinogenicity in rodents.

Metabolic fate and disposition of [14C]hydroquinone given orally to Sprague-Dawley rats.

Hydroquinone (HQ) is used widely in industry and in commerce and is considered to have a low degree of toxicity. Although the metabolism of HQ has been studied elsewhere, a complete materials balance has not been reported. We investigated the metabolism of HQ in naive and HQ pretreated male Sprague-Dawley rats. [14C]HQ was administered by gavage in single doses of 5, 30, or 200 mg/kg to naive rats. HQ was given repeatedly by gavage to male rats at 200 mg/kg for 4 consecutive days followed by a single dose with 200 mg/kg of [14C]HQ. In separate studies rats were fed 5.6% unlabeled HQ in the diet for 2 days or were dosed by gavage with 311 mg/kg [14C]HQ. The excretion patterns of [14C]HQ and its metabolites were similar for rats dosed singly or repeatedly. Rats given a single dose of 200 mg/kg of [14C]HQ excreted 91.9% of the dose in the urine within 2-4 days; 3.8% was excreted in the feces, about 0.4% was excreted in expired air, and 1.2% remained in the carcass. Radioactivity was widely distributed throughout the tissues with higher concentrations in the liver and kidneys. A decrease in 14C tissue concentrations occurred from 48 to 96 h. The only radiolabeled compounds in the urine were HQ (1.1-8.6% of the dose), hydroquinone monosulfate (25-42%), and hydroquinone monoglucuronide (56-66%). Similar findings were observed for rats given HQ in the feed. There were no significant increases from controls for absolute or relative liver weights, liver microsomal protein concentrations, cytochrome b-5, cytochrome P-450 or cytochrome c reductase activity in rats dosed repeatedly with 200 mg/kg HQ. Cytochrome P-450 values were slightly but significantly decreased in rats dosed repeatedly with HQ compared with controls.

Pulmonary and percutaneous absorption of 2-propoxyethyl acetate and 2-ethoxyethyl acetate in beagle dogs.

A comparison was made of the absorption and elimination rates of 2-propoxyethyl acetate (PEA) and 2-ethoxyethyl acetate (EEA) following inhalation, dermal application or IV administration. Male beagle dogs were exposed to 50 ppm PEA or EEA for 5 hr, and breath samples were collected during the exposure and a 3-hr recovery period. Both compounds were rapidly absorbed through the lungs. After 10 min of exposure, the concentrations of the parent compounds in the expired breath were 5 to 10 ppm (80-90% absorption) and reached plateau values at about 3 hr of 13 ppm for PEA (74% absorption) and 16 ppm for EEA (68% absorption). Post-exposure breath samples declined exponentially to 0.5 ppm and 2 ppm after 3 hr for PEA and EEA, respectively. Expired concentrations of PEA were slightly, but significantly (p less than 0.025), lower than those of EEA at corresponding times during the exposure. After IV dosing with 1 mg/kg [ethyl-1,2-14C]PEA, the urine contained 61% and 88% of the dose in 4 and 24 hr, respectively. [14C]EEA was eliminated more slowly, with 20% and 61% of the dose appearing in the urine in 4 and 24 hr, respectively. Blood elimination half-lives were 1.6 hr for [14C]PEA and 7.9 hr for [14C]EEA. Only trace amounts of 14CO2 (less than 1%) or volatile materials (less than 0.1%) were detected in the expired air with either compound. For studies of percutaneous absorption, [14C]PEA or [14C]EEA was added to undiluted compound and applied in a glass cell to a shaved area on a dog's thorax for 30 or 60 min.(ABSTRACT TRUNCATED AT 250 WORDS)