Interactions between dietary selenium, copper and sodium nitroprusside, a source of cyanide in growing chicks and laying hens.

1. Diets containing supplements of selenium (10 mg/kg as sodium selenite), copper (500 mg/kg as copper (II) sulphate) and sodium nitroprusside (SNP 300 mg/kg) as a source of cyanide, were fed singly and in all possible combinations to chicks from 14 to 35 d of age. 2. Both copper and SNP individually alleviated the growth depression caused by excess selenium but interacted adversely with one another. The effect of SNP was to decrease liver selenium but copper increased it. Despite this contrast it is suggested that both achieve their beneficial effects through influences on the fraction of liver selenium that can be reduced to volatile forms by hydrochloric acid and zinc. 3. In a second experiment the effects of diets containing additional selenium (2 mg/kg as sodium selenite or selenomethionine) with or without additional copper (100 mg/kg) or SNP (100 mg/kg) on selenium incorporation into eggs were compared. 4. SNP reduced incorporation from selenite whereas copper had no effect. However, copper reduced the incorporation from selenomethionine into protein fractions of egg white as much as SNP.

Incorporation of selenium into egg proteins from dietary selenite.

1. The deposition of selenium in egg components has been investigated in two experiments in which sodium selenite was added to a conventional cereal-based layer diet. 2. Addition of graded amounts of selenite up to 4 mg Se/kg resulted in linear increases in the selenium content of egg white and yolk, and in protein fractions derived from them. The presence of selenium in yolk phosvitin indicates that deposition is not dependent upon the presence of cysteine. 3. Addition of sodium nitroprusside at 0.l5 and 0.3 g/kg to diets having an addition of selenite at the highest concentration, 4 mg Se/kg, resulted in substantial reductions in the selenium concentration in egg components. 4. Samples from eggs laid by hens receiving a diet containing an additional 8 mg selenite Se/kg were subjected to dialysis against sodium hydroxide or cysteine, or subjected to reduction with hydrochloric acid and zinc under anaerobic conditions. Comparisons were made with similar samples prepared from eggs laid by hens on the control diet. 5. Both sodium hydroxide and cysteine were more effective at extracting additional diet-derived selenium from whole white than from whole yolk. The proportion of selenium that could be extracted from the water-soluble or the high density fractions of yolk by either reagent was similar for both control and high selenium samples. However, neither reagent was effective at removing selenium from the ovalbumin or globin fractions of white from control eggs but substantial amounts were extracted from high selenium samples. 6. Most of the selenium was present in non-reducible forms in all samples. There was significantly more reducible selenium in ovalbumin from control eggs than from all other samples but even so non-reducible selenium accounted for two thirds of the selenium present. 7. The differential responses to chemical treatment suggest that selenium can be deposited in eggs in an unspecified number of different forms. These have still to be characterised but site of formation of egg proteins, liver or oviduct, has a bearing on the forms of selenium deposited.

RNA transcription from immobilized DNA templates.

We describe an RNA transcription protocol based on the multiple reuse of solid-phase synthetic DNA templates. The templates are assembled onto streptavidin-coated agarose beads via a single 5'-terminal biotin located on the noncoding template strand. Transcription occurs in an aqueous buffered suspension containing solid-phase DNA, dissolved enzyme (T7 RNA polymerase), and nucleoside triphosphate substrates (NTPs). A direct comparison of solution and solid-phase templates under standard transcription conditions reveals similar initial reaction rates and overall yields. Immobilized templates store stably for periods of several months and are easily recovered by mild centrifugation. We demonstrate the successive reuse of these templates throughout 15 rounds of transcription. The templates remained active, although an incremental decay in transcription was observed beyond five rounds. Template activity was partially restored by supplementing the support-bound oligonucleotide with fresh coding-strand DNA. These findings indicate that multiple reuse of template is a viable strategy for reducing the amount of DNA template required in RNA transcription.

Time required for elimination of Neisseria gonorrhoeae from the urogenital tract in men with symptomatic urethritis: comparison of oral and intramuscular single-dose therapy.

BACKGROUND AND OBJECTIVES: The spread of sexually transmitted diseases (STDs), including gonorrhea, is affected by the duration of infection. Oral antibiotic therapy for gonococcal infection has been shown to be as effective as conventional intramuscular injection with ceftriaxone. Rapid cure would be expected to limit further spread of gonorrhea. However, the speed with which Neisseria gonorrhoeae is eliminated from the urogenital tract has not been evaluated. GOAL OF THIS STUDY: To determine the time required for elimination of Neisseria gonorrhoeae for the urine, mucosa, and semen in male subjects after treatment with ceftriaxone (250 mg intramuscularly), ciprofloxacin (500 mg by mouth, single dose) or cefixime (400 mg by mouth, single dose.) RESULTS: In 14 subjects, gonococci were eliminated from the urine within 4 hours of therapy and the mucosa within 24 hours after therapy. In 9 additional subjects, gonococci were eliminated from the semen by 24 hours after therapy. CONCLUSIONS: These results support the efficacy of single-dose oral therapy for gonorrhea and suggest that earlier follow-up for proof of cure in clinical trials of new antibiotics for gonorrhea may be acceptable. Rapid elimination of gonorrhea reduces the risk for continued transmission of the organism.

Aloe vera, hydrocortisone, and sterol influence on wound tensile strength and anti-inflammation.

Aloe vera at doses of 100 and 300 mg/kg daily for 4 days blocked the wound healing suppression of hydrocortisone acetate up to 100% using the wound tensile strength assay. This response was because of the growth factors present in A. vera masking the wound healing inhibitors such as sterols and certain amino acids. The sterols showed good anti-inflammatory activity (-36%) in reducing the croton oil-induced ear swelling. This activity displayed a dose-response relationship.

Effect of dietary phytate on growth and selenium status of chicks fed selenite or selenomethionine.

1. An experiment was conducted to study the effect of dietary phytate on the selenium status of chicks fed on a semi-purified diet with or without supplements of sodium selenite or selenomethionine (200 micrograms Selenium/kg). 2. Assessment included measurement of growth and activity of glutathione peroxidase (GSHPx) (EC.1.11.1.9), an enzyme that limits damage by free radical species arising from oxygen metabolism by catalysing the reduction of hydrogen peroxide and lipid hydroperoxides. In addition, information was obtained on forms of selenium in blood, liver, kidney, heart and muscle, distinguishing between selenide-Se, reducible-Se and non-reducible-Se. 3. Phytate caused significant reductions in growth, food consumption and food conversion efficiency. Supplementary selenium was without effect on growth but significantly increased GSHPx activity in all tissues. Phytate also increased GSHPx activity in blood and heart, and in muscle in the absence of supplementary selenium, but decreased the activity in kidney. 4. Concentrations of all forms of tissue selenium were significantly increased by supplementary selenium. In general, there was greater deposition from selenomethionine than from selenite and most was in non-reducible form. 5. Phytate increased selenium in all tissues except muscle; it is not clear if this resulted from increased absorption or increased retention. It increased reducible-Se in blood, liver and heart and non-reducible-Se in blood and kidney. Tissue concentrations of selenide-Se were highly variable: presence or absence of phytate contributed to some significant interactions. 6. The results suggest that there is a positive relationship between phytate and selenium status in chicks, in contrast to its negative effect on growth.

Anti-inflammatory and wound healing activity of a growth substance in Aloe vera.

Aloe vera improves wound healing and inhibits inflammation. Since mannose-6-phosphate is the major sugar in the Aloe gel, the authors examined the possibility of its being an active growth substance. Mice receiving 300 mg/kg of mannose-6-phosphate had improved wound healing over saline controls. This dose also had anti-inflammatory activity. The function of mannose-6-phosphate in A. vera is discussed.

Aloe vera and the inflamed synovial pouch model.

Administration of air under the skin produced a pouch wall that closely resembled a synovium in that the inner lining was made up of macrophages and fibroblasts. Administration of 1% carrageenan directly into the 7-day-old air pouch produced an inflammation characterized by an increased number of mast cells in pouch fluid as well as an increase in wall vascularity. A punch biopsy weight of the pouch wall did not reveal an increase in 1% carrageenan-treated animals. However, a 10% Aloe vera treatment of carrageenan-inflamed synovial pouches reduced the vascularity 50% and the number of mast cells in synovial fluid 48%. The pouch wall punch biopsy weight was increased by A. vera, which was verified by histologic examination of the inner synovial lining. Aloe vera stimulated the synovial-like membrane, as evidenced by an increased number of fibroblasts, suggesting that A. vera stimulated fibroblasts for growth and repair of the synovial model. The synovial air pouch can be used to study simultaneously the acute anti-inflammatory and fibroblast stimulating activities of A. vera.

Isolation of a stimulatory system in an Aloe extract.

The authors' previous work on a 50% ethanol extract of Aloe vera was done to evaluate anti-inflammatory activity using the croton oil-induced ear swelling assay. The anti-inflammatory activity was found in the supernatant fraction. The supernatant fraction decreased inflammation, when applied topically, by 29.2%, and the precipitate decreased inflammation by 12.1%. However, in the present work, the precipitate fraction decreased the wound diameter by an average of 47.1% (stimulatory system). Little or no wound healing activity was found in the supernatant. Aloe vera appears to act as a modulatory system toward wounds and inflammation and is a potentially valuable tool for managing lower extremity conditions.

The isolation of an active inhibitory system from an extract of aloe vera.

An Aloe vera extract was prepared with 50% ethanol. The resultant supernatant and precipitate were tested for anti-inflammatory activity using the croton oil-induced ear-swelling assay. The supernatant fraction decreased inflammation, when applied topically, by 29.2%, and the precipitate decreased inflammation by 12.1%. The authors have shown that the anti-inflammatory activity (inhibitory system) resides in the supernatant of a 50% ethanol extract.

Aloe vera as a biologically active vehicle for hydrocortisone acetate.

Aloe vera, as a biological vehicle for hydrocortisone 21-acetate, was tested topically and systemically against acute inflammation. Systemically, the combination of A. vera and hydrocortisone produced a maximum 88.1% inhibition of edema. Polymorphonuclear leukocyte infiltration was reduced 91.1%. The topical inhibition of edema peaked at 97%. The possibility that A. vera has significant potential as a biologically active vehicle for steroids is discussed.

Reduced selenium status in chicks given diets low in sulphur-containing amino acids and containing sodium nitroprusside as a source of cyanide.

1. Two experiments were carried out to study the effect of dietary cyanide, given in the form of sodium nitroprusside (SNP), on the growth and selenium status of chicks fed on diets low in sulphur-containing amino acids. 2. In experiment 1, SNP (0.3 g/kg) depressed growth rate and food intake when included in diets low in total sulphur-containing amino acids. It also reduced plasma and liver glutathione peroxidase activity (GSH-Px) and kidney selenium concentration. These latter variables also showed increases in response to supplements of selenium of 0.1 and 0.2 mg selenium/kg (as sodium selenite) although growth was not affected. 3. In experiment 2, SNP did not affect growth when reduced to 0.1 g/kg in diets low both in methionine and total sulphur-containing amino acids. It did, however, reduce plasma GSH-Px activity, which again increased in response to similar dietary supplements of selenium. 4. It is concluded that dietary cyanide effectively increases the requirement for selenium and could induce deficiency in diets only marginally adequate in selenium, particularly when the supply of sulphur-containing amino acids was marginal or inadequate.

Vitamin C influence on localized adjuvant arthritis.

This work attempts to determine the influence of vitamin C on locally induced inflammation and arthritis in rat paws, as measured by rat paw swelling, polymorphonuclear leukocyte infiltration, pain, and surface skin temperature. Daily subcutaneous administration of 150 mg/kg of vitamin C over 20 days reduced arthritic swelling, increased pain tolerance, and decreased polymorphonuclear leukocyte infiltration, with no significant change in surface temperature. Vitamin C may provide podiatrists with a supplemental or alternative treatment for patients with rheumatoid arthritis.

Wound healing. Oral and topical activity of Aloe vera.

The influence of Aloe vera, orally and topically, on wound healing was studied. Wounds were induced on both sides of the vertebral column of ICR mice using a biopsy punch. For the oral study, experimental animals received A. vera in their drinking water for 2 months, whereas the control animals received only water. In the topical study, experimental animals were given 25% A. vera in Eucerin cream topically. The control animals received cream only. A 62.5% reduction in wound diameter was noted in mice receiving 100 mg/kg/day oral A. vera and a 50.8% reduction was recorded in animals receiving topical 25% A. vera. These data suggest that A. vera is effective by both oral and topical routes of administration.

Processed Aloe vera administered topically inhibits inflammation.

Aloe vera preparations were evaluated for topical anti-inflammatory activity using the croton oil-induced edema assay. The results show that small amounts of A. vera given topically will inhibit inflammation induced by a moderate amount of irritant. In general, the decolorized Aloe was more effective than the colorized Aloe (with anthraquinone). A 47.1% inhibition of inflammation was obtained by 5% decolorized irradiated Aloe. These results may be used as a baseline to assess the biologic activity of A. vera in the treatment of inflammation by podiatric physicians.

The effect of gamma irradiation on injectable human amnion collagen.

The effect of gamma irradiation on the physicochemical properties of injectable human amnion collagen was investigated. Pepsin-extracted human amnion collagen was purified, reconstituted, and irradiated with varying doses of gamma irradiation (0.25 Mrads to 2.5 Mrads). Gamma irradiation had a significant impact on the physical characteristics of the collagen. The neutral solubility of collagen in PBS at 45 degrees C was decreased from 100% for the nonirradiated control sample to 16% for the 2.5 Mrads irradiated sample. SDS polyacrylamide gel electrophoresis also demonstrated the dose-dependent effect of gamma irradiation on collagen cross-links. Electron microscopic observation revealed that even at low irradiation dose (0.25 Mrads), collagen fibril diameter increased. The average diameter was 50 nm for nonirradiated control fibrils, while 4.4 percent of the irradiated collagen fibrils had a diameter greater than 100 nm. Irradiated collagen showed little evidence of damage. Well-preserved cross-striations were found in collagen fibrils at all doses of irradiation. Native amnion collagen irradiated with gamma rays demonstrated a slight increase in resistance to collagenase degradation compared with nonirradiated native collagen samples. Increased resistance to collagenase did not correlate with increasing irradiation dose. After 30 min of incubation at 37 degrees C, both irradiated and nonirradiated collagen was completely digested by collagenase. However, gamma-irradiated collagen did become more sensitive to hydrolysis by trypsin. The higher the irradiation doses used, the greater sensitivity to trypsin was observed. At 0.25 Mrads irradiation only a slight increase was found. No marked differences in amino acid composition were noted among the high dose irradiated, low dose irradiated and control amnion collagen.

Anti-inflammatory activity of Aloe vera against a spectrum of irritants.

The authors have evaluated the spectrum of anti-inflammatory activity of A. vera in a number of models of inflammation in the hind paw of the experimental rat induced by kaolin, carrageenan, albumin, dextran, gelatin, and mustard. Croton oil was used in a topical model of inflammation to determine the oral activity and time-dependent dosing of A. vera. The authors found that A. vera was active in all models of inflammation. Of the various irritants tested, A. vera was especially active against gelatin-induced and kaolin-induced edema and, in contrast, had minimal activity when tested against dextran-induced edema. Oral activity of A. vera was demonstrated to be dependent on the presence of anthraquinones. The various irritant-induced edema models provided a broad spectrum of anti-inflammatory activity for A. vera.

Aloe vera and gibberellin. Anti-inflammatory activity in diabetes.

Aloe vera inhibits inflammation and adjuvant-induced arthritis. The authors' laboratory has shown that A. vera improves wound healing, which suggests that it does not act like an adrenal steroid. Diabetic animals were used in this study because of their poor wound healing and anti-inflammatory capabilities. The anti-inflammatory activity of A. vera and gibberellin was measured in streptozotocin-induced diabetic mice by measuring the inhibition of polymorphonuclear leukocyte infiltration into a site of gelatin-induced inflammation over a dose range of 2 to 100 mg/kg. Both Aloe and gibberellin similarly inhibited inflammation in a dose-response manner. These data tend to suggest that gibberellin or a gibberellin-like substance is an active anti-inflammatory component in A. vera.

Effect of dietary sodium nitroprusside as a source of cyanide on the selenium status of chicks given diets of varying selenium concentration.

1. The interaction between dietary cyanide, given in the form of sodium nitroprusside (SNP), and selenium has been studied in two experiments with growing chicks from 14 to 38 d of age. 2. In experiment 1, dietary selenium at 10 mg Se/kg reduced growth, food intake and efficiency of utilisation, and increased relative liver size and selenium content. All of these effects were eliminated by the addition of 0.1 g SNP/kg except for liver selenium content, which progressively declined towards control values as SNP was increased to 0.4 g/kg in increments of 0.1 g/kg. At 0.3 g SNP/kg, cyanide toxicity, as judged by decreased growth, reached significance. 3. In experiment 2, similar effects were observed with selenium at 10 mg Se/kg and SNP at 0.3 g/kg, but selenium deficiency was not evident from growth indicators when selenium supplementation of the diet was omitted completely, nor did these indicators suggest that deficiency was induced by cyanide. 4. In both experiments, plasma and liver glutathione peroxidase activity reflected the dietary selenium content. There was an interaction with dietary SNP content. With selenium intake at a toxic level, SNP increased enzyme activity, further evidence of alleviation of selenium toxicity, but when selenium intake was low and normal, SNP decreased activity in liver, an indication that cyanide could induce deficiency. 5. A possible mechanism for alleviation of selenium toxicity is proposed.