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J R Salisbury

Publications and source records attributed to J R Salisbury.

At least 37 records · Page 2Linked to original sources
PubMed1999

Medial localization of mineralization-regulating proteins in association with Mönckeberg's sclerosis: evidence for smooth muscle cell-mediated vascular calcification.

BACKGROUND: Calcification of the media of peripheral arteries is referred to as Mönckeberg's sclerosis (MS) and occurs commonly in aged and diabetic individuals. Its pathogenesis is unknown, but its presence predicts risk of cardiovascular events and leg amputation in diabetic patients. Several studies have documented expression of bone-associated genes in association with intimal atherosclerotic calcification, leading to the suggestion that vascular calcification may be a regulated process with similarities to developmental osteogenesis. Therefore, we examined gene expression in vessels with MS to determine whether there was evidence for a regulated calcification process in the vessel media. METHODS AND RESULTS: In situ hybridization, immunohistochemistry, and semiquantitative reverse-transcription polymerase chain reaction were used to examine the expression of mineralization-regulating proteins in human peripheral arteries with and without MS. MS occurred in direct apposition to medial vascular smooth muscle cells (VSMCs) in the absence of macrophages or lipid. These VSMCs expressed the smooth muscle-specific gene SM22alpha and high levels of matrix Gla protein but little osteopontin mRNA. Compared with normal vessels, vessels with MS globally expressed lower levels of matrix Gla protein and osteonectin, whereas alkaline phosphatase, bone sialoprotein, bone Gla protein, and collagen II, all indicators of osteogenesis/chondrogenesis, were upregulated. Furthermore, VSMCs derived from MS lesions exhibited osteoblastic properties and mineralized in vitro. CONCLUSIONS: These data indicate that medial calcification in MS lesions is an active process potentially orchestrated by phenotypically modified VSMCs.

Adult↗
PubMed1999

A20 RNA expression is associated with undifferentiated nasopharyngeal carcinoma and poorly differentiated head and neck squamous cell carcinoma.

A20 is an anti-apoptotic gene that can be induced in human epithelial cell lines in response to expression of the Epstein-Barr virus (EBV) gene product latent membrane protein 1 (LMP1). EBV is a ubiquitous, persistent human herpesvirus that is consistently associated with undifferentiated nasopharyngeal carcinoma (NPC), in which antigen expression includes LMP1. Consistent with a potential role in the development of NPC, LMP1 has profound effects on epithelial cell growth. A20 may be a key downstream effector of LMP1 in NPC, as LMP1-induced A20 blocks p53-mediated apoptosis in H1299 epithelial cells and most NPCs have wild-type p53. Moreover, the potential role of A20 in the development of epithelial malignancies may extend to tumours not associated with EBV. The purpose of this study was to develop an in situ hybridization assay to assess expression of A20 RNA in undifferentiated NPC and in non-EBV-associated poorly differentiated head and neck squamous cell carcinomas (SCCs) and well-differentiated SCCs of the skin. A20 RNA expression was also examined in normal samples of oral mucosa and skin. Expression of A20 was demonstrated in 76 per cent of undifferentiated NPCs and in 80 per cent of poorly differentiated head and neck SCCs, suggesting a role for A20 in the pathogenesis of these epithelial malignancies. By contrast, A20 RNA was not detected in well-differentiated SCCs of the skin, or in any normal samples of squamous epithelial tissue. The pathway leading to A20 expression in non-EBV-associated poorly differentiated head and neck SCCs is clearly LMP1-independent. LMP1 expression was demonstrated in 29 per cent of NPC biopsies, suggesting an LMP1-independent pathway to A20 induction in undifferentiated NPC.

Animals↗
PubMed1999

Iron proteins of duodenal enterocytes isolated from mice with genetically and experimentally altered iron metabolism.

The molecular basis for the control of iron absorption by the duodenum remains unknown: however, ferritin (Ft) and the iron status of enterocytes have been suggested as regulatory factors. We determined the iron and Ft status of duodenal enterocytes from mice with hypotransferrinaemia, a genetic defect leading to greatly enhanced iron absorption, and for comparison we also investigated mice with experimentally-altered iron absorption. Duodenal enterocytes were isolated and analysed for Ft and non-haem iron content and for transferrin binding (as a measure of transferrin receptor activity). RNA was extracted from the duodenal mucosa and examined for transferrin receptor and H- and L-Ft mRNA levels by Northern hybridization analysis. Ft levels were elevated in enterocytes of hypotransferrinaemic mice, similar to that seen in iron dextran-injected mice of the CD1-strain. Enterocyte Ft levels were reduced in mice fed a diet diminished in iron, but unchanged in hypoxic mice enterocytes. Enterocytes of hypotransferrinaemic mice had normal non-haem iron levels and transferrin binding; however, enterocytes from CD-1 mice fed a low iron diet had increased transferrin binding and a decreased non-haem iron content. Duodenal mRNA levels for transferrin receptor and H-Ft were unchanged in hypotransferrinaemic mice, whereas L-Ft was increased. We conclude from the Ft and non-haem iron contents and transferrin binding that duodenal enterocytes from hypotransferrinaemic mice are not simply iron deficient, leading to increased expression of iron carriers proteins. Duodenal iron absorption can be enhanced in mice even when enterocyte Ft levels are raised or unchanged, suggesting that iron absorption is regulated by developmentally programmed expression of iron transporters by enterocytes.

Animals↗
PubMed1997

In vivo proton magnetic resonance spectroscopy in polymyositis and dermatomyositis: a preliminary study.

The aim of the study is to determine whether biochemical abnormalities, such as lipid, creatine and choline metabolites, are observed in the more distal muscles of polymyositis (PM) and dermatomyositis (DM) patients. 12 patients suffering from chronic active PM/DM and 9 controls underwent a combined proton magnetic resonance (MR) imaging and proton MR spectroscopy study of the calf muscle. From a combination of T1-weighted MR images and corresponding fat suppressed images, fat infiltration into the muscle of both PM and DM patients was consistently observed. Muscular atrophy with a variable distribution was also noted in all patients. The biochemical profile of the localised proton MR spectra of soleus muscle showed reduction of both 'choline' to lipid and 'creatine' to lipid ratios in chronic PM and DM patients when compared with controls.

Adipose Tissue↗
PubMed1997

Epstein-Barr virus latent membrane protein does not inhibit differentiation and induces tumorigenicity of human epithelial cells.

Latent membrane protein (LMP) is a latent Epstein-Barr virus (EBV) protein expressed in the EBV associated malignancy, nasopharyngeal carcinoma (NPC). Properties ascribed to this protein include inhibition of epithelial cell differentiation and deregulation of epithelial cellular gene expression, and are believed to contribute to the development of NPC. Studies to evaluate the oncogenic potential of LMP in epithelial cells have not been conclusive. We carried out studies to determine the tumorigenic activity of LMP in two human epithelial cell lines, SCC12F and HaCaT; while SCC12F LMP transfectants were non-tumorigenic in severe combined immunodeficient mice, HaCaT LMP transfectants were strongly oncogenic. The tumours produced were well differentiated, keratinising squamous cell carcinomas suggesting that LMP does not inhibit epithelial cell differentiation which conflicts with a previous report by Dawson et al. (1990). To resolve this discrepancy we examined the ability of HaCaT and SCC12F LMP transfectants to differentiate in a suspension culture assay. Both lines were able to differentiate to a similar extent as parental lines and control transfectants. Our results indicate that LMP is strongly oncogenic in human epithelial cells but that inhibition of differentiation is not necessarily a mechanism by which LMP contributes to the pathogenesis of NPC.

Animals↗
PubMed1997

Three-dimensional reconstruction of non-Hodgkin's lymphoma in bone marrow trephines.

The objective of this study was to analyse the location in the bone marrow of deposits of low-grade non-Hodgkin's lymphoma. This was achieved using computer-generated three-dimensional reconstruction techniques applied to serial tissue sections of five bone marrow trephines involved by lymphoma. For comparative purposes, previously published three-dimensional models of benign lymphoid aggregates in the bone marrow were need. The images generated by this new study showed that deposits of low-grade non-Hodgkin's lymphoma involving the bone marrow always assumed a paratrabecular pattern of infiltration at some point. This is in direct contrast to the pattern of bone marrow infiltration shown by benign lymphoid aggregates. It is concluded that location within the marrow space is a crucial factor in distinguishing between benign and low-grade malignant lymphoid infiltrates in the bone marrow.

Biopsy↗
PubMed1997

Analysis of the T-cell receptor repertoire in human atherosclerosis.

OBJECTIVE: Analysis of T-cell receptor (TCR) beta-chain gene expression in atherosclerotic lesions of human aorta. METHODS: TCR diversity was studied using non-radioactive polymerase chain reaction for quantitative assessment of TCRBV gene transcripts, together with size and sequence analysis of the beta-chain third complementarity-determining region (CDR3). Samples represent a wide range of atheromatous histology, allowing evaluation of the T-cell repertoire at different stages of disease. RESULTS: Diverse TCRBV family usage was observed in the majority of the samples, as the 25 different TCRBV products were detected at levels exceeding background. The data also showed that TCRBV transcripts expressed in the diseased aorta tissue displayed considerable size heterogeneity and no repetition of CDR3 nucleotide motifs. CONCLUSIONS: The early presence of T-lymphocytes in the atheromatous blood vessel has been interpreted as an indication of specific immunological reactions operating during the course of the atherosclerotic process. Although a T-cell infiltrate characterized by limited usage of TCRAV genes cannot be excluded the unrestricted usage of TCRBV genes argues against a local T-cell clonal expansion in atherogenesis.

Aorta, Thoracic↗
PubMed1997

Time-course of iron overload and biochemical, histopathological and ultrastructural evidence of pancreatic damage in hypotransferrinaemic mice.

1. The time course of iron overload of the pancreas in hypotransferrinaemic mice maintained on a standard rodent diet was compared with biochemical and histological markers of tissue damage. 2. Pancreatic iron levels increased linearly from weaning till 9 months of age [73.3 nmol/mg of tissue (SEM 9.9; n = 5) compared with 0.9 nmol/mg of tissue (SEM 0.1; n = 4) in age-matched controls] then decreased linearly till at least 18 months of age. 3. Investigation of tissue distribution of newly absorbed radioiron suggested that significant redistribution of iron from liver to pancreas (rather than direct dietary iron sources) must be invoked to explain the rate of pancreatic iron loading in hypotransferrinaemic mice. 4. Pancreatic epithelial cells first showed altered morphology at 9 months of age. At 12 months of age, the pancreatic epithelium had developed a micronodular appearance, with large numbers of acini replaced by atrophic, degenerated acinar cells. Increased collagen fibre deposition was evident by trichrome staining and by electron microscopy. Biochemical markers of pancreatitis (serum lipase, tissue pancreatitis-associated protein mRNA) were elevated before 9 months of age, whereas the levels of pancreatic amylase mRNA declined from 9 months of age. 5. The data suggest that iron loading of hypotransferrinaemic mouse pancreas proceeds up to a threshold level at 9 months of age followed by a progressive atrophy of secretory epithelium. The hypotransferrinaemic mouse pancreas is a useful model system for investigation of parenchymal cell damage by iron.

Acute-Phase Proteins↗
PubMed1997

Iron metabolism in transgenic mice with hypoplastic anaemia due to incomplete deficiency of erythropoietin.

Iron overload is a serious complication of many forms of anaemia, arising in part from mechanisms associated with compensatory increases in erythropoiesis. To investigate other mechanisms by which anaemia itself may perturb iron metabolism, without the confounding effects of compensatory erythropoiesis, we studied transgenic mice with a partially disabling insertion in the erythropoietin gene, which manifested as incomplete erythropoietin deficiency. Mice were studied aged 7-8 weeks. Haemoglobin concentrations were 6.6 +/- 0.8 g/dl in mice homozygous for the modified erythropoietin gene, 12.9 +/- 2.2 g/dl in heterozygous mice and 14.1 +/- 1.0 g/dl in controls. Homozygous mice showed significant hepatic iron loading (2-fold increase in liver non-haem iron, compared with heterozygous mice and normal controls, with iron staining principally in the periportal hepatocytes). Absorption studies using 59Fe showed increased uptake from the lumen of an in vivo isolated duodenal segment in homozygous mice, although at this point in time overall transfer of radioiron to the circulation and other tissues (mucosal transfer) was not different from controls. These observations demonstrate that anaemia can lead to hepatic iron loading even in the absence of increased erythropoiesis, and are consistent with the possibility that anaemic hypoxia can enhance mucosal iron uptake by the duodenal enterocyte.

Absorption↗
PubMed1997

Lymphoid infiltrates in B cell non Hodgkin's lymphoma: comparing nuclear characteristics between lymph node and bone marrow; and evaluating diagnostic features of bone marrow infiltrates in paraffin embedded tissues.

Distinguishing non Hodgkin's lymphoma from benign lymphoid aggregates in bone marrow is well recognised to be difficult. Our objective was to evaluate nuclear morphology, and to perform morphometry on benign and neoplastic lymphoid infiltrates, to establish if objective criteria were of value in the diagnosis of neoplasia. By comparing neoplastic infiltrates in bone marrow with infiltrates in lymph nodes, the validity of grading non Hodgkin's lymphoma on the basis of bone marrow histology alone was assessed. 82 cases of B cell non Hodgkin's lymphoma (44 low grade and 38 high grade), known to have both lymph node and bone marrow involvement at the time of presentation, were compared with bone marrow trephines containing reactive lymphoid infiltrates. The results suggest that in paraffin embedded tissue from bone marrow trephines, nuclear morphology, nuclear area and the nuclear contour index cannot, in most cases, be used to distinguish reactive from neoplastic lymphoid infiltrates although mean nuclear area supports a diagnosis of a neoplastic infiltrate if it can be shown that the nuclei are larger than would be expected in reactive infiltrates. Such differences are subtle and often not appreciable without the use of quantitative techniques. The frequent occurrence of discordant infiltrates in high grade lymphomas means grading of lymphoma on the basis of bone marrow appearances is often unrealistic.

B-Lymphocytes↗
PubMed1996

Three-dimensional reconstruction of benign lymphoid aggregates in bone marrow trephines.

Distinguishing between deposits of low-grade non-Hodgkin's lymphoma and benign lymphoid aggregates in bone marrow trephine sections is a recognized problem in haematopathology. To test the hypothesis that benign lymphoid aggregates do not make contact with a trabecular surface, three-dimensional models were constructed of five serially sectioned bone marrow trephines, containing a total of 19 lymphoid aggregates known to be benign. The computer-generated images showed that benign lymphoid aggregates were located in the central marrow space and did not become paratrabecular. This suggests that a paratrabecular location may help in some cases to distinguish deposits of low-grade non-Hodgkin's lymphoma from benign lymphoid aggregates.

Aged↗
PubMed1996

Evaluation of non-isotopic in situ hybridization for mRNA in reactive and neoplastic lymphoid cells.

An evaluation of nonisotopic in situ hybridization (NISH) for mRNA in archival lymphoid tissue was carried out and an analysis of factors affecting the final outcome was performed. A modification of the in situ reverse transcription method for RNA preservation assessment has been used and described. We have shown that, for frozen samples mRNA detection is optimal within 3 months of the biopsy being taken, while preservation declines after 1 year of storage.

Biopsy↗
PubMed1996

The acute and chronic effects of alcohol upon cardiac nucleotide status.

The aim of the investigation was to ascertain the biochemical and morphological basis for the functional impairments in the heart due to alcohol. In chronic studies rats were fed a nutritionally complete liquid diet containing 35% of total calories as ethanol, controls were pair-fed identical amounts of the same diet in which ethanol was replaced by isocaloric glucose. In acute studies rats were injected with ethanol at a dose of 75 mmol/kg body weight. Pre-treatment of acute ethanol-dosed rats with cyanamide (ALDH inhibitor) was designed to raise acetaldehyde levels. In chronic studies ventricular adenine nucleotides, ATP, ADP and AMP; NAD(+), ATP ratios and the energy charge showed no alteration after 6 weeks of alcohol feeding. Light and electron microscopy sections indicated very little structural damage to muscle fibres and organelles (especially the mitochondria) in both atria and ventricles. Ventricular fibre diameters, throughout the different ranges, showed no significant differences between chronically alcohol and control-fed rats. In acute studies an increase in ventricular AMP levels (micromoles/g wet weight) occurred following cyanamide and cyanamide + ethanol treatment (+57%, p < 0.025 and +76%, p<0.01, respectively), but not as a consequence of ethanol alone. Cyanamide+ethanol caused marked elevation in ADP levels (+28%, p < 0.05) and again ethanol was without effect. ATP and GTP levels were not altered by any of the acute treatments. The energy charge was slightly reduced in both cyanamide and cyanamide+ethanol groups (-8%, p < 0.01 and -7%, p < 0.05, respectively), but not by ethanol alone. In conclusion, chronic alcohol appears to have minimal effects upon cardiac nucleotides which suggest that possible adaptive mechanisms are induced during the 6-week period and that alternative pathways other than defects in adenine nucleotide concentrations are involved in the pathogenesis of AHMD. The acute study suggests that the heart is resilient to toxic levels of alcohol and acetaldehyde in terms of ATP and GTP levels, despite the elevated AMP, ADP and GDP levels.

Journal Article↗
PubMed1996

Osmotic diarrhoea and skeletal muscle protein synthesis in vivo.

The pathogenic nature of the wasting seen in diarrhoea is unknown. This study measured protein synthesis in an established model of diarrhoea using lactose for seven days. Comparisons were also made with data obtained from rats fed an identical diet in which lactose was replaced by isocaloric glucose ad libitum (that is, the control diet). To account for diarrhoea induced anorexia, a third group of rats were included, which were fed identical amounts of the control diet as the rats with diarrhoea inducing diet. Comparisons of the diarrhoea induced group with rats fed the control diet ad libitum showed that diarrhoea caused a significant reduction in body weights. Type I and type II muscles showed significant reductions in protein, RNA, and DNA contents, as well as a fall in the derived parameters, RNA/DNA, protein/DNA, and RNA/protein. Fractional rates of protein synthesis (ks) were also reduced. However, synthesis rates of type I and II muscles relative to RNA (kRNA) were unchanged in these muscles in diarrhoea induced rats compared with ad libitum fed controls. In the jejunum there was an increase in the RNA/DNA ratio, and reductions in ks and kRNA. Comparisons were also made between rats with diarrhoea and rats pair fed the control diet. There were no changes in total muscle protein, RNA or DNA contents. This suggests that an important feature of body wasting in diarrhoea is the element of anorexia, which induces severe metabolic changes. The comparison between rats with diarrhoea and the pair fed group showed that histological features of the plantaris were not overtly changed, though diarrhoea caused significant reductions in RNA/DNA, protein/DNA, ks, and kRNA. Similar changes were seen for the soleus; though the reduction in ks failed to attain statistical significance. In the jejunum a comparison of diarrhoea induced rats with pair fed controls, showed increases in the ratios of RNA/DNA and protein/DNA.

Animals↗
PubMed1996

Use of different histomorphometric parameters in the routine assessment of human skeletal muscle biopsies.

In the diagnosis of muscle biopsies it has become traditional to identify any changes in fibre size by measuring minimum fibre diameter (dmin), as past technical constraints prevented the routine measurement of other parameters. The advent of user-friendly computerised image analysis, however, has facilitated such measurements. We examined a total of 39 skeletal muscle biopsies, including normal, myopathic, myositic and neuropathic cases, to determine whether improved discrimination between normal and abnormal histology was now possible on the basis of fibre cross-sectional areas (CSA). Using a semi-automated image analysis system, measurements of dmin, CSA and fibre perimeter were made. In all case groups, the skew of the frequency distribution of area was greater than that of dmin, moreover the difference was more marked in the abnormal cases. As expected, the mean values of dmin and area were reduced in all abnormal cases. As expected, the mean values of dmin and area were reduced in all abnormal cases. The range of their values, however, was reduced in the myopathic and neuropathic cases and increased in the myositic cases. In conclusion, fibre area is a more valuable discriminator between normal and abnormal skeletal muscle than is dmin.

Histocytochemistry↗
PubMed1995

A histomorphometric study of bone changes in thyroid dysfunction in rats.

Clinical studies in thyrotoxicosis reveal a state of high bone turnover leading, eventually, to osteoporosis. Recently there has been concern that thyroxine (T4) treatment may have a similar effect on bone. Rat models have been used to study the effects of T4 on bone, but the majority of studies have looked at the effects of T4 after only 3 weeks of treatment. The aim of this study was to evaluate histomorphometric changes in rats after 12 weeks of thyroxine overtreatment or 12 weeks of hypothyroidism compared with untreated control animals. Animals received either T4 200 micrograms/kg per day, 0.1% propylthiouracil, or vehicle for 12 weeks. Tetracycline was administered 1 week and 3 weeks prior to killing. Iliac crest bone was used for histomorphometry. Serum T4 measurements (taken at killing) confirmed hyper- and hypothyroidism in the appropriate animal groups (between group difference p < 0.001 by ANOVA). In hyperthyroid animals there was an increase in mineral apposition rate (MAR; 0.94 vs. 0.59 microns/day, p < 0.001) and mineral formation rate (MFR/BS; 0.24 vs. 0.12 x 10(-2) micron3/micron2 per day, p < 0.001) and a slight increase in eroded surfaces (ES/BS%; 1.54 vs. 1.36, p < 0.05) compared with controls, consistent with previous in vitro and in vivo observations. In hypothyroid rats there was a marked reduction in osteoid surfaces (OS/BS%; 1.7 vs. 24.8, p < 0.001) and MAR (0.3 vs. 0.59 micrograms/day, p < 0.001), a reduction in ES/BS% (0.51 vs. 1.36, p < 0.05), and an increase in cancellous bone volume (BV/TV%; 30.29 vs. 19.6, p < 0.05), suggesting that thyroid hormones are a requirement for normal bone turnover.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1995

Genotype study of non-Hodgkin's lymphoma.

DNA from 47 patients with non-Hodgkin's lymphoma (NHL) was studied for immunoglobulin and T-cell receptor (TCR) gene rearrangements with Southern blot hybridization. In 83% of the cases the genotypic changes were consistent with immunophenotypic and morphologic examination. Two cases showed mixed genotype and 9 cases of B-cell NHL (67% of centroblastic, 36% of follicular and 33% of large cell anaplastic) showed a population of cells with TCR gamma rearrangements in addition to immunoglobulin rearranged bands. We compared the TCR gamma variable region usage in these rearrangements in B-cell NHL with T-cell NHL and reactive hyperplasia. In T-cell NHL TCR gamma variable regions located at the 3' part of the variable locus were used more often, whilst in B-cell NHL regions of the 5' portion of the locus were preferentially used. Our results confirm the genotypic heterogeneity of histologically defined subtypes of NHL.

Adult↗