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PubMed1990

Analysis of 3'-azido-3'-deoxythymidine levels in tissues and milk by isocratic high-performance liquid chromatography.

A sensitive high-performance liquid chromatographic (HPLC) assay was established to analyze levels of the antiretroviral agent 3'-azido-3'-deoxythymidine (AZT, zidovudine) in serum, milk and tissue extracts. After methanol precipitation, serum samples could be injected directly into the HPLC apparatus, whereas tissue extracts required further clarification. Recovery of AZT was virtually complete. Isocratic elution with a mobile phase consisting of 6% acetonitrile and 0.1 M ammonium acetate, pH adjusted to 4.5 with glacial acetic acid, resulted in good resolution of AZT and its metabolites; retention times for AZT and the internal standard, p-nitrophenol, were 20 and 37 min, respectively. Using this method, we have demonstrated that AZT crosses both the blood-brain and placental barriers and is excreted into milk at high levels.

Animals↗
PubMed1994

Inhibin and follistatin concentrations in fetal tissues and fluids during gestation in sheep: evidence for activin in amniotic fluid.

The concentrations of inhibin and follistatin in amniotic fluid and in tissue extracts from the placenta, gonads and adrenals of fetal sheep were measured using radioimmunoassays. These tissue extracts were from whole fetuses from days 16 to 45 and from the individual organs from day 46 to 145 (term) and were assayed at multiple dilutions. The capacity of these extracts to alter FSH production of rat anterior pituitary cells in culture was also assessed at multiple dilutions. Immunoactive inhibin concentrations in amniotic fluid from both sexes increased during gestation and levels were significantly greater in males than females. Peak concentrations of immunoreactive inhibin of 11.2 +/- 1.9 ng/ml were found in males at 116-125 days of gestation. Follistatin concentrations did not change throughout gestation and no significant difference was noted between sexes. Mean follistatin levels throughout gestation were 3.0 +/- 0.9 ng/ml for males and 3.7 +/- 0.9 ng/ml for females. Despite the potential for FSH inhibition by inhibin and follistatin, amniotic fluid from both sexes at all stages of gestation stimulated FSH secretion in the pituitary cell bioassays, suggesting the presence of activin which was confirmed by the measurement of immunoactive activin (13.3 +/- 2.5 ng/ml) in a specific radioimmunoassay. Maximum concentrations of immunoactive and bioactive inhibin in placental extracts were observed in late gestation (2.2 +/- 0.6 and 3.8 +/- 1.6 ng/g respectively) and there was no significant difference between sexes. Follistatin concentrations in placental cotyledons ranged from 11.5 to 27.1 ng/g with no significant difference between sexes. In view of the higher follistatin concentrations compared with inhibin, it is likely that the capacity of placental extracts to suppress FSH production by pituitary cells in culture is due predominantly to follistatin. Immunoactive inhibin was observed in high concentrations in the fetal testis throughout gestation; with concentrations increasing to a maximum of 1993.0 +/- 519.7 ng/g at 126-135 days of gestation with a ratio of bioactive: immunoactive inhibin of 1:20. Although bioactive and immunoactive inhibin was also observed in fetal ovaries and adrenals from both male and female fetuses, concentrations were lower than those observed in fetal testes. Follistatin concentrations in the fetal testis were elevated between 70 and 95 days (97.6 ng/g) and then declined. Similar concentrations were found in the adrenal glands of both sexes (males 83.5-103.3 ng/g: females 55.3-95.8 ng/g).(ABSTRACT TRUNCATED AT 400 WORDS)

Activins↗
PubMedDate not supplied

Quantitation of enhanced expression of ras-oncogene product (p21) in childhood renal tumours.

A monoclonal antibody, RAP-5, raised against the 21,000d ras-oncogene product, p21, was used in an immunoperoxidase staining procedure to study the expression of p21 in normal children's and foetal kidneys, pre-malignant lesions and benign and malignant childhood renal tumours with good, moderate or poor prognosis. ras-p21 was expressed in both normal and foetal kidneys but its distribution in renal tumours differed markedly (p less than 0.01). A quantitative liquid competition radioimmunoassay (RIA) was used to determine ras-p21 level in tissue homogenates. The results were expressed as pg of ras-p21 per microgram protein of tissue extract. There were significant differences in the levels of ras-p21 among various renal tissue extracts (p less than 0.05). Generally it emerged that the amount of ras-p21 was greater in both malignant renal tumours and foetal kidneys compared to normal kidneys, pre-malignant lesions and benign renal tumours.

Antibodies, Monoclonal↗
PubMed1991

Effects of protein phosphatase inhibitors on the regulation of insulin-sensitive enzymes within rat epididymal fat-pads and cells.

1. The effects of the protein phosphatase inhibitors okadaic acid and microcystin LR on the regulation by insulin of pyruvate dehydrogenase and acetyl-CoA carboxylase have been studied in rat epididymal fat-pads and isolated cells. These inhibitors both completely blocked the phosphatase activity (against phosphorylase a) present in extracts of epididymal fat-pads, with half-maximal effects in the nanomolar range. 2. Okadaic acid treatment of pads and cells lowered the activity of acetyl-CoA carboxylase assayed in tissue extracts, both before and after treatment of the extracts with the activator, citrate. Further, okadaic acid treatment abolished the 2-3-fold difference in activity observed between extracts from control and insulin-treated tissues, assayed without prior treatment with citrate. 3. Incubation of pads with [32P]Pi, sufficient to label the intracellular pool of ATP, demonstrated that okadaic acid increased the overall phosphorylation of acetyl-CoA carboxylase on a number of distinct sites, as judged by two-dimensional mapping of tryptic peptides. These included the 'I-peptide' [Brownsey & Denton (1982) Biochem. J. 202, 77-86], the phosphorylation of which may be associated with the stimulation of the activity of the enzyme by insulin, as well as inhibitory phosphorylation sites. 4. Incubation with 1 microM-okadaic acid had no effect on the basal level of active pyruvate dehydrogenase apparent after tissue extraction, but abolished the 2-3-fold increase in this parameter which was elicited by insulin in the absence of okadaic acid. However, okadaic acid treatment did not affect the persistent increase in active pyruvate dehydrogenase levels which was apparent in mitochondria subsequently isolated from insulin-treated pads and re-incubated with an oxidizable substrate. It is concluded that the effects of okadaic acid are exerted through changes in metabolite concentrations rather than some direct action on the signalling pathway whereby insulin stimulates pyruvate dehydrogenase. 5. Microcystin LR did not mimic the effects of okadaic acid on intact cells and pads described above.

Acetyl-CoA Carboxylase↗
PubMed2000

Quantitative analysis of matrix metalloproteinases-2 and -9, and their tissue inhibitors-1 and -2 in human placenta throughout gestation.

To elucidate the implication of type IV collagenases(MMP-2 and MMP-9) and their tissue inhibitors (TIMP-1 and TIMP-2) for placental development, we quantified their levels in the conditioned media of placental organ culture and primary culture of the trophoblast as well as in the tissue extracts of placentas from different stages of gestation using specific enzyme-linked immunosorbent assays. First trimester villous tissue secreted about 10 times more pro-MMP-2 than pro-MMP-9, and pro-MMP-2 levels dramatically decreased in the second trimester. On the other hand, pro-MMP-9 levels were more than 10 times higher than those of pro-MMP-2 in the primary culture of the first trimester trophoblast, indicating the involvement of stromal cells for prominent pro-MMP-2 secretion from first trimester villous tissue described above. Levels of TIMPs, especially those of TIMP-2, remained constant throughout gestation both in the culture media and tissue extracts. Gelatin zymography revealed abundant secretion of the active form of MMP-2 as well as pro-MMP-2 from first trimester villous tissue. Western immunoblot analysis confirmed the presence of both TIMP-1 and TIMP-2 in placental tissue. These results suggest that active secretion of MMP-2 from villous tissue in the first trimester and constant production of TIMPs throughout gestation are characteristic of placental development.

Blotting, Western↗
PubMed1982

Absence of pork-like insulin in guinea pig tissues.

By using a technique for concentrating insulin 100-fold from tissue extracts with 75-95% recoveries, we earlier failed to detect pork-like insulin in guinea pig tissues and thus were unable to confirm reports from the National Institutes of Health that these tissues contain a pork-like insulin at concentrations averaging 1 ng/g. This difference could have been due to differences in strains of guinea pigs studied or in the species specificities of the antisera used for radioimmunoassay. In the current study, tissue extracts from both NIH and Hartley guinea pigs were assayed with three antisera routinely used in our laboratory and one antiserum that had been used in the National Institutes of Health laboratory. We observed that pork-like insulin in tissues from both strains of guinea pigs as determined with the four antisera is less than 0.02 ng/g. We therefore conclude that is is unlikely that nonpancreatic guinea pig tissues contain or synthesize a peptide resembling pork or other non-guinea pig mammalian insulin.

Animals↗
PubMed1978

The H, HI, I and i blood group antigens in butanol extracts of rabbit tissues.

Aqueous and butanol phase extracts of rabbit erythrocytes and the tissues gastric mucosa, liver, lung and kidney were examined by inhibition of agglutination for the presence of H, HI, I and i blood group substances. Of the four specificities, only I substance was recovered from erythrocytes and only in the aqueous phase extracts. Both aqueous and butanol extracts of gastric mucosae contained H substance, but HI and I were present only in the aqueous extracts of this tissue. Extracts of rabbit lungs only had H and I activity and only in the aqueous phase. No H, HI, I or i substance was detected in any of the extracts of liver and kidney. Reduced levels of H substance were found in aqueous extracts of gastric mucosae of 'A-like' rabbits. Three H specificities were demonstrated in the butanol phase extracts of gastric mucosae of rabbits. These specificities were similar to those previously shown in extracts of gastric mucosae and erythrocytes of humans.

ABO Blood-Group System↗
PubMed1993

Fibrin binding, fibrinolytic and fibrinogenolytic activity of plasminogen activator derived from the paranasal mucous membrane of humans.

It is known that large amounts of plasminogen activator (PA) are contained in tissue extracts of the human paranasal mucous membrane (PMM) with chronic sinusitis. The present study was undertaken to isolate and purify the PA in tissue extracts of PMM. Furthermore, the purified PA was identified as to whether it was of the tissue type or urokinase (UK) type, and some of its fibrinolytic characteristics were determined in comparison with those of urokinase. As starting material, extracts of acetone powder of PMM with chronic sinusitis were used, and Zn-imminodiacetate affinity chromatography, and ultrafiltration were carried out to separate and purify the PA from the PMM. The PA was purified to a 107-fold increase in specific activity. The molecular weight of the PA was estimated to be 65,000 to 70,000 d by gel filtration using Sephacryl S-200. The purified PA was stable in the range of pH 8.0 to 9.0. Using S-2288, a synthetic substrate, the Michaelis constant (Km) of the purified PA was estimated to be 0.11 mmol. The binding of the purified PA to fibrin was stronger than that of UK, while the fibrinogenolytic activity of the purified PA was not stronger than that of UK. Based on these results, the purified PA was identified as a tissue-type plasminogen activator (t-PA). From the kinetic data, it was identified as being of the two-chain variety. It is considered that, as a thrombolytic agent, t-PA derived from the PMM could be more useful than UK.

Animals↗
PubMed1990

Decreased levels of IL-1 alpha and beta in psoriatic lesional skin.

Interleukin 1 (IL-1), which mediates a wide range of biological activities, is thought to play an important role in many inflammatory and immunologic diseases. Normal human epidermal keratinocytes constitutively produce IL-1. Based on our previous data indicating decreased IL-1 activity in psoriatic scale extracts, in the present study, we measured immunoreactive IL-1 alpha and beta levels in the suction blister fluids as well as in the psoriatic scale extracts using enzyme immunoassay for IL-1 alpha and beta. The results showed that although similarly low levels of IL-1 alpha were detectable in the suction blister fluid from normal and psoriatic lesional skin, and that no IL-1 beta was found in most of the blister fluids, indicating that IL-1 alpha is major IL-1 species produced by human skin. As compared to those in the blister fluids, IL-1 alpha levels in the horny tissue extracts were found to be much higher, and they were significantly higher in the orthokeratotic stratum corneum extracts than in the psoriatic scale extracts. However, gel filtration of the orthokeratotic horny tissue extracts demonstrated that constituents for immunoreactive IL-1 alpha and beta were quite variable depending upon the source of the horny tissues. The present study has confirmed that IL-1 levels in the psoriatic scale extracts are decreased when compared with those in the orthokeratotic horny tissue possibly due to an increased epidermal proliferation activity associated with its high turnover rate. The role of IL-1 psoriatic lesions remains unknown.

Adolescent↗
PubMed1985

Determination of mouse liver 5-methyltetrahydrofolate concentration and polyglutamate forms.

The concentration and polyglutamate status of 5-methyltetrahydrofolate in mouse liver tissue extracts has been determined by enzymatic conversion to methylenetetrahydrofolate and subsequent entrapment of this cofactor form into a ternary complex with Lactobacillus casei thymidylate synthase and tritiated 5-fluorodeoxyuridylate. 5-Methyltetrahydrofolate was oxidized to methylenetetrahydrofolate using the reverse reaction of methylenetetrahydrofolate reductase with menadione as the ultimate electron acceptor. Reference 5-methyltetrahydrofolate could be quantitatively recovered from tissue extracts by this method. The polyglutamate status of enzymatically converted and complexed tissue 5-methyltetrahydrofolate was determined electrophoretically. Unlabeled 5-fluorodeoxyuridylate was used to remove endogenous methylenetetrahydrofolate prior to enzymatic oxidation of 5-methyltetrahydrofolate and subsequent electrophoretic analysis. In this manner, the 5-methyltetrahydrofolate polyglutamate pool alone could be labeled and visualized. There were no observable differences in the polyglutamate distribution of endogenous methylenetetrahydrofolate versus 5-methyltetrahydrofolate polyglutamates in extracts of normal mouse liver tissue.

Animals↗
PubMed1989

Absence of tumor necrosis factor-alpha in suction blister fluids and stratum corneum from patients with psoriasis.

Tumor necrosis factor (TNF)-alpha is a cytokine with multiple biological properties, particularly proinflammatory, apart from the induction of tumor necrosis. In order to elucidate the role of TNF-alpha in the pathogenesis of psoriasis, we have carried out bioassay and enzyme-linked immunosorbent assay for TNF-alpha in suction blister fluids and horny tissue extracts from psoriatic skin. Although bioassay showed some activities in the suction blister fluids and horny tissue extracts, there were no significant differences between the levels of activities from normal and psoriatic skin. They were at the background level and pretreatment of the samples with anti-TNF-alpha antiserum failed to abrogate the activities. ELISA confirmed the absence of TNF-alpha. Therefore, the present study could not verify that TNF-alpha plays a major role in the pathogenesis of psoriasis.

Adolescent↗
PubMed1989

A simple, sensitive, and specific radioreceptor assay for inositol 1,4,5-trisphosphate in biological tissues.

Inositol (1,4,5)P3 (IP3) receptors in rat cerebellar membranes have been used to develop a radioreceptor assay for endogenous IP3. The assay is sensitive, detecting as little as 1 pmole IP3 in a 0.5 ml volume. The receptor is highly selective for the 1,4,5-isomer of IP3 so that assays can employ crude tissue extracts with no purification. Chromatographic analysis and selective enzymatic hydrolysis of IP3 show that in crude tissue extracts only authentic IP3 is detected. A hundred or more samples can be assayed in a day for endogenous IP3.

Animals↗
PubMed1975

Location of gluconeogenesis from phosphoenolpyruvate in cotyledons of Cucurbita pepo.

1. The aim of this work was to discover the location of the enzymes that convert phosphoenolpyruvate to fructose 6-phosphate during gluconeogenesis in fatty seeds. Cotyledons of 5-day-old dark-grown seedlings of marrow (Cucurbita pepo) were used as experimental material. 2. Cotyledons were separated into palisade and mesophyll tissue. Extracts of the two tissues had comparable activities of gluconeogenic enzymes. 3. Extracts of cotyledons were fractionated by density gradient centrifugation to yeild mitochondria and glyoxysomes, and by gel filtration to yield proplastids. The isolated organelles retained their characteristic ultrastructure and appreciable amounts of marker enzymes. The proportions of the total activities of phosphoglyceromutase and fructose-1, 6-diphosphatase recovered in the mitochondrial and glyoxysomal preparations were insignificant. The same was true for the activities of phosphoglyceromutase and phosphopyruvate hydratase found in the proplastid preparations. 4. Extracts of a number of other gluconeigenic plant tissues were centrifuged at 2500 times g to yield particulate preparations. None of these preparations contained a significant proportion of the total activity of phosphoglyceromutase. 5. It is suggested that gluconeogenesis from phosphoenolpyruvate in plants occurs in the cytoplasm.

Cell Fractionation↗
PubMed1997

An enzyme immunoassay for polymorphonuclear leucocyte-mediated fibrinogenolysis.

Upon stimulation, polymorphonuclear leucocytes (PMNs) release potent serine proteases, i.e. elastase, cathepsin G and proteinase 3, which contribute to the degradation of tissue and plasma components. Here, we describe the development of a plasma test to assess PMN-mediated fibrinogenolysis as a biochemical marker for actual PMN-derived proteolysis in vivo, useful for monitoring therapeutic efficacy, i.e. of elastase inhibitors. We generated a monoclonal antibody (MAb), designated 1-1/B3, with a high affinity for elastase-degraded fibrinogen (EDF). The epitope for 1-1/B3 becomes exposed in a time-dependent manner during digestion of fibrinogen with purified PMN-derived serine proteases and with isolated PMNs in vitro. However, 1-1/B3 does not react with plasma fibrinogen or with fibrin(ogen) degradation products generated by plasmin or by other active proteases that may occur locally, i.e. metalloproteases and lysosomal cathepsins. On the basis of MAb 1-1/B3, we developed a plasma test for the assessment of PMN-mediated fibrin(ogen) degradation products (PMN-FDP). In a panel of control plasmas, we observed concentrations of PMN-FDP of 8.2 +/- 0.9 ng mL-1 (n = 18). These values were increased twofold in patients with alpha 1-proteinase inhibitor deficiency (18.6 +/- 3.3 ng mL-1; n = 12; P < 0.0001) and even more in patients with sepsis (365.7 +/- 97.7 ng mL-1; n = 16; P < 0.0001). Furthermore, synovial tissue extracts from patients with rheumatoid arthritis contained increased levels of PMN-FDP, compared with synovial tissue extracts (P < 0.005) from patients with osteoarthritis.

Antibodies, Monoclonal↗
PubMed1983

Efficient extraction of RNA from mammalian tissue.

RNA extraction from mammalian tissue has been compared using the different deproteinizing agents: a) guanidine-HCl, b) guanidinium-thiocyanate, c) buffer-saturated phenol, or d) buffer-saturated phenol followed by a proteinase K digestion of the aqueous phase. Both solid tissues (first, second, and third trimester fetal bovine pancreas), and human white blood cell populations were studied. Degradation, as seen in citric acid-urea agarose gels, and the ability to serve as templates for cell-free protein synthesis were used as criteria to assess the efficiency of the different methods. We conclude that employing buffer-saturated phenol with proteinase K digestion is a superior method for consistent extraction of relatively undegraded RNA in quantitative amounts from mammalian tissue.

Animals↗
PubMed2001

Type I collagen turnover and cross-linking are increased in irradiated skin of breast cancer patients.

BACKGROUND AND PURPOSE: The effects of radiation therapy on the turnover and structure of type I collagen were studied in irradiated and contralateral skin of 18 breast cancer patients without clinically evident fibrosis. MATERIALS AND METHODS: The rates of on-going type I collagen synthesis and degradation were assessed by the aminoterminal propeptide of type I procollagen (PINP) and by two different assays (ICTP and SP4) for the carboxyterminal telopeptide of type I collagen in the soluble tissue extracts, respectively. Also, TIMP-1, TIMP-2 and the MMP-2/TIMP-2 complex were measured in the tissue extracts. Insoluble skin matrices, containing the cross-linked type I collagen fibres, were heat-denatured and digested with trypsin. Then, the variants of the carboxyterminal telopeptide of type I collagen were separated by high performance liquid chromatography (HPLC). The major histidinohydroxylysinonorleucine (HHL)-cross-linked variant was quantified by the SP4 assay, and the minor pyridinoline analogue (PA)-cross-linked telopeptide was quantified by the ICTP assay. RESULTS: Both the synthesis and degradation of type I collagen were increased (r=0.906; P<0.001) on the irradiated side, whereas the concentration of the MMP-2/TIMP-2 complex was decreased. In the insoluble tissue digests, the HHL-cross-linked telopeptides of type I collagen, also, when expressed/tissue hydroxyproline, were increased in the irradiated skin. TIMP-1, TIMP-2 or PA-cross-linked telopeptides of type I collagen showed no differences between the two sides. CONCLUSIONS: Radiotherapy induces a long-term increase in the turnover of type I collagen and leads to the accumulation of cross-linked type I collagen in skin.

Adult↗
PubMed1980

Radioimmunoassay of the myelin basic protein in biological fluids, conditions improving sensitivity and specificity.

The radioimmunoassay (RIA) for myelin basic protein (MBP) in biological fluids was reassessed in order to improve its sensitivity and eliminate some interferences. By using the preincubation technique and the charcoal-dextran-horse serum mixture for the separation step, the detection limit could be lowered to 200 pg/ml for cerebrospinal fluids (CSF), amniotic fluids (AF) and nervous tissue extracts and 600 pg/ml for sera. The RIA could be used directly on CSF, AF and nervous tissue extracts. Sera, however, had to be heated in citrate buffer at 100 degrees C in order to discard interfering material. The present method is 10 to 20 times more sensitive than others previously published. Moreover, it can be applied to amniotic fluid. The biological fluids had to be promptly frozen to avoid degradation of MBP.

Amniotic Fluid↗
PubMed1989

Enhancement of transcription from the Ad2 major late promoter by upstream elements of the fibroin- and sericin-1-encoding genes in silk gland extracts.

The activity of the upstream promoter element (UPE) of the Bombyx mori fibroin-encoding gene was analyzed by using the major late promoter (MLP) of adenovirus 2 (Ad2) as the basal promoter. The UPE reveals remarkable stimulatory activity on the transcription of Ad2 MLP in tissue extracts prepared from the posterior silk gland where the fibroin-encoding gene is specifically expressed. This stimulation of transcription is due to an increase of initiation complex formation as shown by a one-round transcription assay. The UPE of the sericin-1-encoding gene, which is specifically expressed in the middle silk gland, also stimulates Ad2 MLP transcription in a similar manner. The results of the competition experiments indicate that the stimulatory effect is mediated by trans-acting factors which bind to these UPE. These two UPE are also active in tissue extracts of the middle silk gland, but are nearly inactive in extracts from the ovarian tissue and an embryonic cell line, Bm-e21. These observations further support the hypothesis that a silk-gland-specific factor(s) is responsible for this tissue-specific transcription in vitro. The possible molecular basis of this silk-gland specificity is discussed in light of the various trans-acting factors known to bind these UPE.

Adenoviruses, Human↗