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1.
Vet Ophthalmol ; 2024 Jun 11.
Article in English | MEDLINE | ID: mdl-38862255

ABSTRACT

A 9-year-old, female spayed domestic short-haired cat was presented with a 4-year history of bilateral lipogranulomatous conjunctivitis (LGC), which was confirmed via histopathology. Thirteen months following the initial biopsy, the cat was presented with a rapidly progressive mass lesion of the palpebral conjunctiva of the right eye. A surgical debulking, followed 1 month later by exenteration after marked regrowth of the mass confirmed fibrosarcoma. This case report is the first to describe a cat with chronic bilateral LGC that later developed a unilateral fibrosarcoma within the eyelid tissue of the right eye. Fibrosarcoma should be considered a differential in any cat with chronic LGC that develops a rapidly progressive mass in the eyelid.

2.
Hum Reprod ; 36(2): 415-428, 2021 01 25.
Article in English | MEDLINE | ID: mdl-33313846

ABSTRACT

STUDY QUESTION: What are the detailed endometrial tissue specific and systemic dendritic cell (DC) subset disturbances in endometriosis? SUMMARY ANSWER: This study confirms myeloid DC (mDC) and plasmacytoid DC subsets are readily identified in endometrial tissue and shows both endometrial and circulating differences in DC populations in women with endometriosis, with disease stage-specific relationships evident locally in the endometrium. WHAT IS KNOWN ALREADY: Immune factors in the uterus, the peritoneal environment and systemically are implicated in the pathogenesis and progression of both endometriosis and infertility. While there is some evidence that endometrial DC populations are altered in endometriosis, DC subset involvement in both the endometrium and peripheral blood have not been comprehensively investigated so the functional consequences have been unknown. STUDY DESIGN, SIZE, DURATION: This prospective cross-sectional cohort study compares circulating and endometrial DC populations in women of reproductive age with and without endometriosis (n = 55 and 30, respectively), wherein each participant donated samples at a single time point. Study participants were surveyed for menstrual cycle phase, American Society for Reproductive Medicine (ASRM) endometriosis disease stage and fertility status (where possible). PARTICIPANTS/MATERIALS, SETTING, METHODS: Peripheral blood samples were processed into mononuclear cells for analysis by flow cytometry, and endometrial samples were analysed by immunohistochemistry and dissociated into single-cell suspension for flow cytometry. MAIN RESULTS AND THE ROLE OF CHANCE: In the endometrium of women with endometriosis, IRF-8+ cells were increased during the proliferative phase (P = 0.014), total DC proportions increased in the secretory phase (P = 0.038) and normal menstrual cyclical fluctuations in CD1c+ and IRF-8+ cells blunted; indicative of a consistently inflammatory tissue environment. The inflammatory changes in CD141+ and IRF-8+ populations in the endometrium of women with endometriosis were particularly evident in more advanced ASRM stages of the disease (respective P-values 0.032 and 0.045). There was also evidence of systemic inflammation in women with endometriosis, with increased circulating CD141+ mDC proportions (overall P = 0.040, secretory phase P = 0.021). LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: As is common in this type of study, one of the main limitations was small sample numbers, particularly during the menstrual phase of the cycle. WIDER IMPLICATIONS OF THE FINDINGS: Further phenotyping of local and circulating immune cell subtypes is critical to improving understanding of endometriosis pathogenesis and immune contributions to infertility associated with the disease. STUDY FUNDING/COMPETING INTEREST(S): This research was financially supported by a Sydney Medical School and Balnaves Foundation Kick Start Grant and the Department of Obstetrics, Gynaecology and Neonatology at The University of Sydney. The authors have no conflicts of interest to declare.


Subject(s)
Endometriosis , Cross-Sectional Studies , Dendritic Cells , Endometrium , Female , Flow Cytometry , Humans , Immunohistochemistry , Pregnancy , Prospective Studies
3.
School Ment Health ; 15(3): 851-872, 2023.
Article in English | MEDLINE | ID: mdl-37720164

ABSTRACT

Mindfulness-informed school-based mental health curricula show much promise in cultivating a positive school climate which supports the well-being and mental health of pupils and staff. However, non-positive pupil outcomes and experiences of school-based mental health interventions are often under-recognised and under-reported. This study sought to capture non-positive pupil experiences of a popular mindfulness-informed curriculum. Some pupils across all schools in the study described non-positive experiences, including having troubling thoughts and emotions, and not finding the programme effective. Contexts surrounding these experiences are explored and linked to existing literature, and subsequent recommendations for improvements are made, including the importance of having clear programme structure, definitions and aims, acknowledging and accommodating fidelity issues as best as possible, and better highlighting the potential for non-positive experiences and how they may be reduced.

4.
Chem Senses ; 37(5): 431-44, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22248457

ABSTRACT

Hyperphagia is a reported side effect of anxiolytic benzodiazepines such as chlordiazepoxide (CDP). Prior research has focused primarily on the ingestive responses to sweet or solid foods. We examined CDP effects on licking for normally accepted and avoided taste solutions across a range of concentrations. The effect of CDP (10 mg/kg) versus saline on the licking patterns of water-restricted rats for water and 3 concentrations of sucrose, saccharin, NaCl, monosodium glutamate (MSG), citric acid, and quinine (Q-HCl) solutions was evaluated during 1 h tests. CDP increased meal size for all tastants except citric acid. Analysis of licking microstructure revealed 3 dissociable effects of CDP. CDP affected oromotor coordination as indicated by a uniform increase in the modal interlick interval for all stimuli. CDP increased meal size as indicated by shorter pauses during consumption of water, MSG, and weaker saccharin concentrations, and by fewer long interlick intervals (250-2000 ms) for normally avoided tastants. CDP also increased meal size by increasing burst size, burst duration, and the initial rate of licking for most solutions, suggesting increased hedonic taste evaluation. CDP did not affect variables associated with postingestive feedback such as meal duration or number of bursts, and the results also suggest that CDP did not enhance the perceived taste intensity. We hypothesize that the reduction of pause duration is consistent with an increased motivation to sample the stimulus that synergizes with changes in taste-mediated responsiveness to some but not all stimuli to yield increases in the consumption of both normally accepted and avoided taste stimuli.


Subject(s)
Anti-Anxiety Agents/pharmacology , Chlordiazepoxide/pharmacology , Feeding Behavior/drug effects , Grooming/drug effects , Hyperphagia/metabolism , Animals , Citric Acid/pharmacology , Hyperphagia/physiopathology , Male , Quinine/pharmacology , Rats , Rats, Sprague-Dawley , Saccharin/pharmacology , Sodium Chloride/pharmacology , Sodium Glutamate/pharmacology , Sucrose/pharmacology , Taste/drug effects , Water Deprivation
5.
J Exp Med ; 123(6): 1097-108, 1966 Jun 01.
Article in English | MEDLINE | ID: mdl-5941783

ABSTRACT

Elastin fibers in the aortas of control, lathyritic, copper-supplemented, and copper-deficient chicks were examined histochemically and chemically for aldehyde content. Diminished staining for aldehydes was obtained in the fibers from the aortas of lathyritic and copper-deficient chicks. Chemical studies of elastin isolated from the aortas of control and lathyritic chicks showed an apparent loss of lysine residues in control elastin to be associated with an increase in aldehyde content providing evidence that lysine is converted to an aldehyde-containing intermediate during biosynthesis of desmosine and isodesmosine. Approximately 6 aldehyde groups were present for every 1000 amino acids in elastin isolated from the aortas of control animals, while the corresponding number in lathyritic elastin was 4. At least two types of aldehydes, saturated and alpha,beta-unsaturated, appear to be associated with elastin, suggesting the presence of more than one intermediate between lysine and the desmosines.


Subject(s)
Aldehydes , Copper , Deficiency Diseases , Elastin , Lathyrism , Animals , Aorta , Histocytochemistry , Poultry
6.
J Exp Med ; 147(6): 1584-95, 1978 Jun 01.
Article in English | MEDLINE | ID: mdl-567240

ABSTRACT

Fibronectin, a fibroblast surface protein, was purified from human and chicken plasma and extracts of cultured chicken fibroblasts with affinity chromatography on gelatin coupled to Sepharose particles. A fibronectin-like protein was also isolated from the plasma of Torpedo fish. The collagen binding properties of fibronectin were studied with several genetically distinct collagens. Heat denatured types I, II, and III collagens were equal in their binding capacity and more active than the native collagens or A and B chains. Native type III collagen was more active than the other native collagens. Human and chicken fibronectins showed approximately the same pattern of specificity. Identical specificities were shown by the plasma and fibroblast forms of chicken fibronectin. Two cyanogen bromide peptides of the collagen alpha1 (II) chain, CB8 and CB12, derived from different parts of the chain, were active in fibronectin binding. A polymer of the tripeptide pro-gly-pro, and polyproline were inactive. Fibronectin also binds to fibrinogen and fibrin. Comparison of this binding to collagen binding showed that fibrinogen inhibited binding of fibronectin to collagen, but was less active than native collagen. Two other fibrous proteins, tropoelastin and keratin, did not bind fibronectin. The binding of fibronectin to fibrinogen was inhibited by collagen and incorporation of fibronectin into blood clot in the cold was inhibited by gelatin. These results suggest that the binding of fibronectin to collagen and fibrinogen depends on the same binding site in the fibronectin molecule. It is proposed that cell surface fibronectin mediates attachment of cells to the collagenous extracellular matrix and to a temporary fibrin matrix in a wound.


Subject(s)
Collagen/metabolism , Fibrinogen/metabolism , Fibroblasts/metabolism , Glycoproteins/metabolism , Membrane Proteins/metabolism , Animals , Binding Sites , Blood Coagulation/drug effects , Chickens , Fibrin/metabolism , Fishes , Gelatin/pharmacology , Humans , In Vitro Techniques , Keratins/metabolism , Peptides/metabolism , Species Specificity , Tropoelastin/metabolism
7.
J Exp Med ; 123(4): 599-614, 1966 Apr 01.
Article in English | MEDLINE | ID: mdl-4160396

ABSTRACT

Intravenous immunization of New Zealand red rabbits with streptococcal group-specific bacterial vaccines yielded sera which possessed markedly elevated gamma-globulin. The sera of one rabbit immunized with Group A-variant vaccine possessed 55 mg/ml of gamma-globulin. The bulk of this gamma-globulin, identified as gamma(G)-globulin, was homogeneous by zone electrophoresis and of specificity directed against the Group A-variant carbohydrate antigen. L chains isolated from specific antibody obtained from an immune precipitate were distributed as a single band on starch gel electrophoresis, whereas the normal gamma-globulin traveled as a diffuse smear. These data suggest that the rabbit streptococcal Group A-variant antibodies possess a limited range of physicochemical properties and electrophoretic mobility compared to that generally observed for the normal complement of gamma-globulin.


Subject(s)
Antibodies , Antibody Formation , Bacterial Vaccines/pharmacology , Streptococcus , gamma-Globulins/biosynthesis , Adsorption , Animals , Antigens , Blood Proteins , Chromatography, Gel , Electrophoresis , Immune Sera , Immunoelectrophoresis , In Vitro Techniques , Precipitin Tests , Rabbits
9.
J Emerg Manag ; 18(2): 183-184, 2020.
Article in English | MEDLINE | ID: mdl-32181873

ABSTRACT

Preparing for public health emergencies is an ongoing process and involves a variety of approaches and tools. Tabletop exercises are one of the tools designed to simulate the emergence of a public health emergency and address some or all of the phases of emergency management: mitigation, preparedness, response, and recovery.1 They typically are designed to include participation of stakeholders from diverse and complementary backgrounds, including command, operations, logistics, planning, and finance.2 Effective tabletop exercises provide a plausible scenario that require cooperation and communication from these functional areas. Tabletops also require forward thinking and planning in a variety of scenarios. When a public health emergency occurs, decision makers may be overwhelmed with decisions that need their immediate attention. Tabletop exercises can provide a framework to help decision makers anticipate future challenges, which may provide the mental model encompassing knowledge and insights that inform both current and future decisions.


Subject(s)
Betacoronavirus/pathogenicity , Coronavirus Infections/epidemiology , Disaster Planning/organization & administration , Disease Outbreaks , Emergencies , Pneumonia, Viral/epidemiology , COVID-19 , Humans , SARS-CoV-2 , Universities
10.
J Cell Biol ; 92(2): 343-9, 1982 Feb.
Article in English | MEDLINE | ID: mdl-7037794

ABSTRACT

Antibodies specific for the alpha 1 (V) chain and native collagen molecules containing the alpha 1 (V) chain have been used in electron immunohistochemical studies of rat kidney to determine the ultrastructural distribution of this class of collagen molecules. In addition, antibodies against type I collagen and whole basement membrane were used as markers for interstitial collagen and authentic basement membranes. Our results indicate that type V collagen is present in the renal interstitium in different forms: in close apposition to interstitial collagen fibers; in the stromal aspect of vascular basement membranes; and as particulate material not bound to other structures. On the basis of these findings, we postulate a binding or connecting function for this collagen type.


Subject(s)
Collagen/metabolism , Kidney/ultrastructure , Animals , Basement Membrane/ultrastructure , Collagen/immunology , Collagen/physiology , Extracellular Space/physiology , Immunologic Techniques , Rats
11.
Science ; 183(130): 1200-1, 1974 Mar.
Article in English | MEDLINE | ID: mdl-4812351

ABSTRACT

Collagen moleculess with the chain comizposition [alpha1(III)](3), have been isolated from pepsin-solubilized collagen of dermis, aorta, and leiomlyoma of the uterus by differential salt precipitation. On denaturation, approximately 90 percent of this collagen is recovered as a gamma component (300,000 daltons). Reduction and alkylation of the high-molecular-weight component yields alpha1(III) chains (95,000 daltons). In addition to containing cysteine, alpha1(III) chains exhibit several other compositional differences when compared to alpha1(I), alpha1(II), or alpha2 chains from human tissues.


Subject(s)
Collagen/analysis , Polymorphism, Genetic , Amino Acid Sequence , Amino Acids/analysis , Aorta, Thoracic/analysis , Autoanalysis , Chromatography, Ion Exchange , Collagen/biosynthesis , Female , Humans , Infant, Newborn , Leiomyoma , Molecular Weight , Skin/analysis , Uterine Neoplasms
12.
Science ; 161(3840): 475-6, 1968 Aug 02.
Article in English | MEDLINE | ID: mdl-5659685

ABSTRACT

Administration of D-penicillamine and lathyrogens such as beta-amino-propionitrile to animals markedly alters connective tissue by preventing the normal cross-linkage of elastin and collagen. It had been shown that beta-aminopropionitrile blocks the cross-linkage of elastin and collagen by preventing the initial step in cross-linkage: the conversion of lysine in peptide linkage to alpha-amino adipic-delta-semialdehyde. We show that penicillamine acts after the initial step, causing the accumulation of an elastin rich in alpha-amino adipic-delta-semialdehyde.


Subject(s)
Amino Acids/biosynthesis , Collagen/metabolism , Connective Tissue/metabolism , Elastin/metabolism , Penicillamine/pharmacology , Peptide Biosynthesis , Adipates , Aminopropionitrile/pharmacology , Animals , Aorta/analysis , Aorta/embryology , Chick Embryo/metabolism , Depression, Chemical , Lathyrism/metabolism , Lysine
13.
Sci Rep ; 9(1): 16487, 2019 11 11.
Article in English | MEDLINE | ID: mdl-31712639

ABSTRACT

We model the presence of rare Antarctic blue whales (Balaenoptera musculus intermedia) in relation to the swarm characteristics of their main prey species, Antarctic krill (Euphausia superba). A combination of visual observations and recent advances in passive acoustic technology were used to locate Antarctic blue whales, whilst simultaneously using active underwater acoustics to characterise the distribution, size, depth, composition and density of krill swarms. Krill swarm characteristics and blue whale presence were examined at a range of spatiotemporal scales to investigate sub meso-scale (i.e., <100 km) foraging behaviour. Results suggest that at all scales, Antarctic blue whales are more likely to be detected within the vicinity of krill swarms with a higher density of krill, those found shallower in the water column, and those of greater vertical height. These findings support hypotheses that as lunge-feeders of extreme size, Antarctic blue whales target shallow, dense krill swarms to maximise their energy intake. As both Antarctic krill and blue whales play a key role in the Southern Ocean ecosystem, the nature of their predator-prey dynamics is an important consideration, not only for the recovery of this endangered species in a changing environment, but for the future management of Antarctic krill fisheries.


Subject(s)
Balaenoptera , Ecosystem , Euphausiacea , Predatory Behavior , Animals , Antarctic Regions
14.
J Clin Invest ; 73(6): 1569-75, 1984 Jun.
Article in English | MEDLINE | ID: mdl-6427276

ABSTRACT

Collagens extracted from bones, cartilage, dermis, and dura mater of an infant with type II (lethal perinatal) osteogenesis imperfecta were evaluated with respect to chain composition and chemical characteristics of their constituent chains. The results indicated that the various types of collagen were present in the indicated tissues in proportions that approximated normal tissues. Nevertheless, the constituent chains of collagens extracted from dermis, i.e., alpha 1(I), alpha 2(I), alpha 1(III), alpha 1(V), and alpha 2(V), chromatographed on carboxymethyl cellulose as though they possessed substantially lower overall positive charge than the homologous chains of normal tissues. Amino acid analyses of the chains confirmed this observation and showed that the chains lacked five to seven residues of lysine (plus hydroxylysine). It was subsequently shown that the apparent deficiency in lysyl residues was due, at least in part, to the presence of unusually high levels of allysine , a cross-link precursor formed from peptide-bound lysine under the catalytic action of lysyl oxidase. These results, in conjunction with previous results obtained on collagens from type II osteogenesis imperfecta tissues, suggest that aberrant fibril formation in this syndrome allows increased lysyl oxidase activity.


Subject(s)
Bone and Bones/metabolism , Collagen/metabolism , Lysine/metabolism , Osteogenesis Imperfecta/metabolism , Amino Acids/analysis , Collagen/isolation & purification , Dura Mater/metabolism , Female , Humans , Infant, Newborn , Skin/metabolism
15.
J Clin Invest ; 99(11): 2581-7, 1997 Jun 01.
Article in English | MEDLINE | ID: mdl-9169487

ABSTRACT

Melanoma growth stimulatory activity (MGSA/GROalpha) is a 73 amino acid peptide sharing sequence characteristics with the alpha-chemokine superfamily. MGSA/GROalpha is produced by diverse melanoma cell lines and reported to act as an autocrine growth factor for the cells. We tested the binding of MGSA/GROalpha to melanoma cell lines, Hs 294T and RPMI7951, and found that these cells could bind to MGSA/GROalpha but not to interleukin-8. Recently, we defined a novel hexapeptide, antileukinate, which is a potent inhibitor of binding of alpha-chemokines to their receptors on neutrophils. When antileukinate was added to melanoma cells, it inhibited the binding of MGSA/ GROalpha. The growth of cells from both melanoma cell lines was suppressed completely in the presence of 100 microM peptide. The cell growth inhibition was reversed by the removal of the peptide from the culture media or by the addition of the excess amount of MGSA/GROalpha. The viability of Hs 294T cells in the presence of 100 microM peptide was > 92%. These findings suggest that MGSA/GROalpha is an essential autostimulatory growth factor for melanoma cells and antileukinate inhibits their growth by preventing MGSA/GROalpha from binding to its receptors.


Subject(s)
Chemokines/antagonists & inhibitors , Melanoma/pathology , Peptides/pharmacology , Cell Division/drug effects , Humans , Peptides/chemistry , Tumor Cells, Cultured
16.
Mol Cell Biol ; 8(3): 1179-85, 1988 Mar.
Article in English | MEDLINE | ID: mdl-3285176

ABSTRACT

The RAD6 gene of Saccharomyces cerevisiae, which is required for normal tolerance of DNA damage and for sporulation, encodes a 172-residue protein whose 23 carboxyl-terminal residues are almost all acidic. We show that this polyacidic sequence appends to RAD6 protein as a polyanionic tail and that its function in vivo does not require stoichiometry of length. RAD6 protein was purified to near homogeneity from a yeast strain carrying a RAD6 overproducing plasmid. Approximately the first 150 residues of RAD6 protein composed a structural domain that was resistant to proteinase K and had a Stokes radius typical of a globular protein of its calculated mass. The carboxyl-terminal polyacidic sequence was sensitive to proteinase K, and it endowed RAD6 protein with an aberrantly large Stokes radius that indicates an asymmetric shape. We deduce that RAD6 protein is monomeric and comprises a globular domain with a freely extending polyacidic tail. We tested the phenotypic effects of partial or complete deletion of the polyacidic sequence, demonstrating the presence of the shortened proteins in the cell by using antibody to RAD6 protein. Removal of the entire polyacidic sequence severely reduced sporulation but only slightly affected survival after UV irradiation or UV-induced mutagenesis. Strains with deletions of all but the first 4 or 15 residues of the polyacidic sequence were phenotypically almost wild type or wild type, respectively. We conclude that the intrinsic activity of RAD6 protein resides in the globular domain, that the polyacidic sequence has a stimulatory or modifying role evident primarily in sporulation, and that only a short section apparently functions as effectively as the entire polyacidic sequence.


Subject(s)
Fungal Proteins/genetics , Genes, Fungal , Ligases/genetics , Saccharomyces cerevisiae Proteins , Saccharomyces cerevisiae/genetics , Alleles , Amino Acid Sequence , Chromatography, Gel , DNA Damage , Electrophoresis, Polyacrylamide Gel , Fungal Proteins/analysis , Fungal Proteins/biosynthesis , Ligases/analysis , Ligases/biosynthesis , Phenotype , Plasmids , Saccharomyces cerevisiae/physiology , Spores, Fungal , Ubiquitin-Conjugating Enzymes
17.
Biochim Biophys Acta ; 446(1): 240-4, 1976 Sep 28.
Article in English | MEDLINE | ID: mdl-974114

ABSTRACT

The Type III collagen molecule, [alpha](III)]3, is comprised of three alphal(III) chains each of which contains two cysteinyl residues. Free sulfhydryl groups, however, could not be detected in the denatured, trimeric gamma-component of Type III collagen as judged by the failure to form derivatives with the alkylating reagents iodo-[14C]acetic acid and 4-vinylpyridine. This absence of sulfhydryl group reactivity did not appear to result from disulfide-binding between Type III collagen and noncollagenous peptides. Collectively, the results indicate that all of the six sulfhydryl groups of the Type III collagen molecule participate in interchain disulfide-bonding.


Subject(s)
Collagen , Amino Acids/analysis , Binding Sites , Humans , Infant , Iodoacetates , Peptide Fragments/analysis , Protein Binding , Protein Conformation , Skin , Sulfhydryl Compounds/analysis
18.
Biochim Biophys Acta ; 1340(1): 123-30, 1997 Jun 20.
Article in English | MEDLINE | ID: mdl-9217022

ABSTRACT

SPAAT has previously been shown to be a competitive inhibitor of the model serine protease, chymotrypsin. We now present evidence that SPAAT is likewise a competitive inhibitor of human neutrophil elastase and cathepsin G with Ki's of 15-20 and 40 microM, respectively. The mechanism of this inhibition was investigated by comparing the relative effectiveness of the 23-residue N-terminal fragment of SPAAT (N-SPAAT) to inhibit chymotrypsin and human neutrophil elastase. N-SPAAT, which does not contain the primary chymotrypsin cleavage site, was approximately 10-fold less effective as an inhibitor of chymotrypsin than SPAAT (Ki of 65 microM versus 7.5 microM). In contrast, this fragment, which contains the primary human neutrophil elastase cleavage site, was found to competitively inhibit human neutrophil elastase with a Ki of 24 microM which was comparable to that of SPAAT (Ki = 15-20 microM). Thus it appears that SPAAT is a reversible inhibitor of these enzymes rather than an irreversible, stoichiometric one like its parent protein, AAT. Such fragmentation of AAT, however, might provide a mechanism whereby a cascade of decreasingly potent, but increasingly specific SPAAT-related inhibitory peptides could be generated. These results further substantiate the view that SPAAT may play a role in vivo in the protection of extracellular proteins from inappropriate attack by proteases which are elevated during various pathophysiological conditions.


Subject(s)
Peptide Fragments/pharmacology , Serine Proteinase Inhibitors/pharmacology , alpha 1-Antitrypsin/chemistry , Amino Acid Sequence , Binding, Competitive , Cathepsin G , Cathepsins/antagonists & inhibitors , Cathepsins/metabolism , Chromatography, High Pressure Liquid , Chymotrypsin/antagonists & inhibitors , Chymotrypsin/metabolism , Humans , Leukocyte Elastase/antagonists & inhibitors , Leukocyte Elastase/metabolism , Neutrophils/enzymology , Peptide Fragments/chemistry , Serine Endopeptidases , Trypsin/metabolism
19.
Biochim Biophys Acta ; 625(1): 78-88, 1980 Sep 23.
Article in English | MEDLINE | ID: mdl-7417504

ABSTRACT

Limited proteolysis of preparations of mature rabbit cornea with pepsin allows the recovery of approximately 90% of the tissue collagen in soluble form. Using recently described selective precipitation techniques, the soluble cornea collagen can be resolved into two major fractions. The predominant fraction, which accounts for about 95% of the solubilized collagen, was identified by means of solubility properties, electrophoretic and chromatographic properties, as well as amino acid analyses of its constituent chains, as Type I collagen. The alternate fraction, which accounts for virtually all of the remainder of the solubilized cornea collagen, was identified by means of the same criteria as collagen comprised of the A and B chains. In addition, the stoichiometry of the latter chains in preparations of cornea collagen indicate that in the cornea these chains are likely to participate in the formation of only one type of collagen molecule with the chain composition, AB2. And finally, the demonstration that Type I and the AB2 collagens are the predominant forms of collagen recoverable from the mature cornea strongly suggests that molecules comprised of the A and B chains are not necessarily confined to basement membrane structures.


Subject(s)
Collagen/isolation & purification , Cornea/metabolism , Amino Acids/analysis , Animals , Chromatography, Ion Exchange , Collagen/analysis , Collagen/genetics , Electrophoresis, Polyacrylamide Gel , Rabbits
20.
Biotechniques ; 22(3): 528-34, 1997 Mar.
Article in English | MEDLINE | ID: mdl-9067033

ABSTRACT

In some mammalian cells transfected with luciferase reporter genes, the luciferase/luciferin reaction in a cell monolayer produces a very small light flux. While the low light levels are often measurable with single-photon counting cameras, these devices are expensive and may require long averaging times to acquire an image. We describe an approach for real-time monitoring of light produced by luciferase gene expression in intact, cultured cells using readily available and relatively inexpensive components. The system uses a single-photon counting photomultiplier tube with built-in high voltage supply and photon counting circuitry to rapidly measure average light output from growing cells in a 35 mm culture dish. The fast, accurate and highly sensitive response of the system makes it useful for studying the dynamics of gene expression over time periods ranging from minutes to days.


Subject(s)
Gene Expression , Genes, Reporter , Luciferases/genetics , Photometry/methods , Antineoplastic Agents, Hormonal/pharmacology , Cells, Cultured , Estradiol/pharmacology , Genes, Reporter/genetics , Humans , Light , Luciferases/metabolism , Photometry/economics , Photometry/instrumentation , Photons , Tamoxifen/pharmacology , Time Factors , Tumor Cells, Cultured
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