Vascular co-localization of proteolytic enzymes and proteinase inhibitors in advanced periodontitis.

Sections of tissue biopsies obtained from advanced, destructive periodontitis were compared with minimally inflamed periodontal tissues in relation to the distribution of type I (interstitial) collagenase. Immunohistochemistry using a highly specific antiserum showed weak staining of occasional vessels in minimally inflamed specimens but widespread reactivity, localized to the vasculature, in advanced disease. In situ hybridization confirmed the vascular source of type I collagenase.

Microvascular angiopathy in advanced periodontal disease.

Previous studies have shown a perivascular hyaline thickening affecting restricted regions of the microcirculation in gingivitis and moderate periodontitis and in the pulpal vessels in chronic pulpitis. In the present study of the lesion of advanced periodontitis, immunostaining for type IV collagen and laminin demonstrated widespread deposition of basement membrane material, with manifest involvement of the venous network. Some vessels were associated with an increased deposition of both basement membrane proteins, while others showed preferential deposition of either laminin or type IV collagen.

Hospital admissions for lower respiratory tract illness before the age of two years in western Australia.

In this study, hospital admissions for lower respiratory tract illness before two years of age have been documented for all children born in Western Australia in 1986. Admissions data were linked to birth and death records for individual children. Of the total cohort, 5% of non-Aboriginal and 17% of Aboriginal children were hospitalised only once for lower respiratory tract illness; 1% of non-Aboriginal and 11% of Aboriginal children had repeated admissions.

Elevated levels of corticotrophin-releasing factor binding protein in the blood of patients suffering from arthritis and septicaemia and the presence of novel ligands in synovial fluid.

In view of the reported inflammatory effects of corticotrophin-releasing factor (CRF) and the associated regulatory elements in the gene of its binding protein (BP), we postulate that both BP as well as novel BP-ligands other than CRF may be involved in inflammatory disease. We have investigated BP in the blood of patients with arthritis and septicaemia and have attempted to identify CRF and other BP-ligands in synovial fluid. The BP was found to be significantly elevated in the blood of patients with rheumatoid arthritis and septicaemia.

Intranuclear post-transcriptional down-regulation responsible for loss of a keratin differentiation marker in tumour progression.

Apparent loss of differentiation markers characterizes advanced malignant neoplasms. Post-transcriptional down-regulation of keratin message to levels undetectable with a partial cDNA probe to rat keratin K5 had been observed in anaplastic cells (T952/F7) derived from benign keratin-producing cells (A5P/B10) (1). The entire fifth introns of both the K5 and K6 genes were generated from rat genomic DNA by PCR to define expression of these closely related proteins.

Immunohistochemical and ultrastructural evidence of a modified microvasculature in the giant cell granuloma of the jaws.

A panel of five immunohistochemical markers, MB1, leukocyte common antigen, S-100 protein, smooth muscle specific actin, and factor VIII related antigen, were used to study 20 giant cell lesions. These included eight central giant cell granulomas, nine peripheral giant cell granulomas, and three giant cell tumors of bone. The multinucleated giant cells stained positively with MB1, the mononuclear round cells were positive to leukocyte common antigen and the spindle cells were unreactive to all the markers chosen in all the lesions.

A population database for maternal and child health research in Western Australia using record linkage.

This paper describes a linked total population database established in Western Australia for monitoring and evaluating maternal and child health and for conducting epidemiological studies. Good vital statistics data including all Western Australian hospitalisations and excellent birth defects and cerebral palsy registers have ensured that complete data are available. Examples of studies which have been conducted using the database are given.

Corticotropin-releasing factor binding protein dimerizes after association with ligand.

We have suggested recently that the fall in plasma CRF-binding protein (BP) during the last few weeks of pregnancy is a direct effect of association with its ligand because of the rapid decrease in plasma BP concentration seen in normal males reaching a nadir some 15 min after a bolus injection of synthetic CRF. In the present study, we have investigated the physicochemical properties of both natural and recombinant BP by gel filtration under physiological conditions and have shown that association of human CRF to this BP results in an increase in molecular weight consistent with the formation of a dimer form of the BP ligand complex. The dimer is more stable when the interaction occurs in the presence of serum or if a peptide with a higher affinity for the BP is substituted as ligand.

Hospital admissions before the age of 2 years in Western Australia.

A linked data file of birth records and hospital admissions was used to investigate inpatient hospital morbidity before 2 years of age for all non-Aboriginal and Aboriginal children born in Western Australia in 1986. Of the non-Aboriginal children, 31.8% were admitted to hospital at least once before the age of 2 years, with an overall admission rate of 526/1000 live births; the corresponding figures for Aboriginal children were 68.

Multiple levels of post-transcriptional regulation of collagenase (matrix metalloproteinase 1) in an epithelial cell line.

Multiple levels of regulation of collagenase (matrix metalloproteinase 1; MMP-1), have been demonstrated in a clonal rat epithelial cell line (A5P/B10). Secreted enzyme could not be demonstrated in culture medium from A5P/B10 cells but, using antibodies specific for collagenase, the enzyme was detected within the cytoplasm and on the surface of the cells. A probe for rat collagenase could not detect a signal for mRNA in the cytoplasm while nuclear run-on data demonstrated that the gene for collagenase was being transcribed.

Loss of keratin expression in anaplastic carcinoma cells due to posttranscriptional down-regulation acting in trans.

Rat keratin K5 and vimentin complementary DNAs have been isolated, identified, and used to study keratin and vimentin expression as markers for cell differentiation. Isologous rat neoplastic epithelial cell lines used were based on a clonal benign epithelial line (A5P/B10) and a clonal anaplastic malignant derivative line (T952/F7). Stable cytoplasmic mRNA was detected for keratin but not vimentin in the benign cells.

The identification, purification and characterisation of an inhibitor of collagenase (20K) produced by neoplastic epithelial cells.

A rat carcinoma cell line (T2/H7) constitutively synthesised interstitial collagenase. When these cells were incubated with 12-O-tetradecanoylphorbol 13-acetate (TPA) they secreted an inhibitor of collagenase, which resulted in a net decrease of collagenolytic activity being detected in conditioned medium. Using reverse zymography, the Mr of the inhibitor was found to be 20,000 which suggests that it may be the rat homologue of inhibitor of metalloproteinase 2 (IMP2; TIMP-2), as it inhibited both the gelatinolytic and collagenolytic activities of rat collagenase.

Different malignant phenotypes induced in a stable, subdiploid, benign epithelial clone by DNA transfection.

Progression to malignancy in carcinomas has been studied in a stable, benign, subdiploid, cloned epithelial cell line (A5P/B10) sensitive to Geneticin at 100 micrograms/ml. A total of 28 cell lines were selected for Geneticin - resistance and inoculated into the footpads of syngeneic animals following co-transfection with pSV2neo and genomic DNA, or transfection with plasmid constructs containing neo and the activated Ha-ras oncogene. The behavior of 12 cell lines cotransfected with normal genomic DNA and inoculated into 146 footpads was the same as the A5P/B10 cells.

Interstitial collagenase (matrix metalloproteinase 1) associated with the plasma membrane of both neoplastic and nonneoplastic cells.

Epithelial cell lines (BC1, BC3, BC4, and BC5), derived from 4 separate invasive and metastatic rat mammary carcinomas, all secreted interstitial collagenase (matrix metalloproteinase 1, MMP 1) in culture. Neither a cloned cell line (A5P/B10), derived from a noninvasive rat epithelial tumor, nor nonneoplastic rat fibroblasts secreted the enzyme. Western blot analyses of proteins extracted from the plasma membranes indicated the presence of interstitial collagenase (MMP 1) on the surface of all of the 6 cell lines.

The nucleotide sequence of the sigma factor gene ntrA (rpoN) of Azotobacter vinelandii: analysis of conserved sequences in NtrA proteins.

The nucleotide sequence of the Azotobacter vinelandii ntrA gene has been determined. It encodes a 56916 Dalton acidic polypeptide (AvNtrA) with substantial homology to NtrA from Klebsiella pneumoniae (KpNtrA) and Rhizobium meliloti (RmNtrA). NtrA has been shown to act as a novel RNA polymerase sigma factor but the predicted sequence of AvNtrA substantiates our previous analysis of KpNtrA in showing no substantial homology to other known sigma factors.

Experimental neovascularization in vivo: the early changes in a stable adult vasculature responding to angiogenic stimulation by a syngeneic neoplasm.

To examine the vascular changes that lead to the development of new vessel sprouts from differentiated vessels the early response of an uninjured, stable, adult vascular bed to the presence of neoplastic tissue has been studied. Small grafts of a squamous cell carcinoma were implanted above the cremaster muscle of host rats syngeneic with the rat in which the neoplasm arose. The vascular response was examined by light microscopy of whole cremaster preparations after intravenous injection of colloidal carbon to label leaky vessels, and by scanning electron microscopy of methyl methacrylate injection casts.

A rapid and efficient method for plasmid transformation of Klebsiella pneumoniae and Escherichia coli.

A rapid and efficient method for plasmid transformation of Klebsiella pneumoniae M5a1 and Escherichia coli K12 has been developed. The method, which uses a freeze-thaw cycle in the presence of CaCl2 to facilitate DNA uptake, is substantially more efficient for K. pneumoniae M5a1 than the conventional transformation procedure for E.

The nucleotide sequence of the nitrogen-regulation gene ntrA of Klebsiella pneumoniae and comparison with conserved features in bacterial RNA polymerase sigma factors.

The nucleotide sequence of the Klebsiella pneumoniae ntrA gene has been determined. NtrA encodes a 53,926 Dalton acidic polypeptide; a calculated molecular weight which is significantly lower than that determined by SDS polyacrylamide gel analysis. NtrA is followed by another open-reading frame (orf) of at least 75 amino acids.

Evidence that noradrenaline increases pyruvate dehydrogenase activity and decreases acetyl-CoA carboxylase activity in rat interscapular brown adipose tissue in vivo.

The rate of fatty acid synthesis in interscapular brown adipose tissue of female cold-adapted rats, as measured by the incorporation of 3H from 3H2O into tissue lipid, was decreased by about 70% after injection of noradrenaline. There was a similar decrease in the activity of acetyl-CoA carboxylase. In contrast, the proportion of pyruvate dehydrogenase in its active non-phosphorylated form was greatly increased after injection of noradrenaline.

Epithelial cell motility: the effect of 2-deoxyglucose on cell migration, ATP production, and the structure of the cytoplasmic ground substance in lamellipodia of epithelial cells in culture.

Using a line of epithelial cells (SCCA5) derived from a spontaneous rat carcinoma, the glucose analogue 2-deoxyglucose (2DG) has been shown by time-lapse cinemicrography to produce a cessation of motility by 1 hour that can be reversed by replacement of the 2DG, and does not occur in equivalent media with or without glucose or in 2DG-containing media with added pyruvate and citrate. The effect on the cells at the edge of an epithelial island is to prevent the formation of new lamellipodia and produce a progressive retraction and condensation of lamellipodia already present. This effect of 2DG on motility corresponds with a significant reduction in the level of ATP that is partially restored after 30 minutes in the recovery incubation.