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Biomedical subjects

B Noble

Publications and source records attributed to B Noble.

At least 19 recordsLinked to original sources
PubMed1997

Nasal polyposis: immunohistochemistry and bioelectrical findings (a hypothesis for the development of nasal polyps).

Nasal polyps and turbinates were obtained from individuals undergoing surgery for symptomatic nasal obstruction caused by nonatopic rhinosinusitis or allergic rhinosinusitis. One part of the tissue from each patient was fixed in neutral buffered formalin and prepared for study by histochemical and immunohistochemical methods. Monoclonal antibodies were used to identify macrophages, lymphocytes, and plasma cells. In most cases (12 of 16, 75%) the remainder of the polyp and turbinate samples was treated with protease to achieve disaggregation of the epithelial cells. Those cells were cultured on permeable collagen matrix supports. Transepithelial potential difference and resistance were measured daily. At the time of maximal transepithelial potential difference, the epithelial cells were mounted in modified. Ussing chambers and exposed to a sodium-positive channel blocker (amiloride hydrochloride) and to selected chloride-negative channel agonists (isoproterenol bitartrate and adenosine triphosphate). Middle turbinates and polyps were found to have more macrophages, lymphocytes, plasma cells, HLA-DR-positive cells, and eosinophils than the inferior turbinates. Epithelial cells obtained from polyps exhibited higher transepithelial potential differences and equivalent short-circuit currents than turbinate cell cultures. The responses to amiloride, isoproterenol, and adenosine triphosphate were also greater for polyp than for turbinate cultures. A theory for the pathogenesis of nasal polyps is proposed. Local release of inflammatory mediators could cause sodium absorption and chloride permeability to be higher in polyps than in turbinate epithelia. Increased sodium absorption is consistent with the hypothesis that epithelial fluid absorption contributes to the development of nasal polyps and is a result of the increased recruitment of inflammatory cells, which are present in nasal polyps.

Adenosine Triphosphate↗
PubMed1997

Mutation analysis of BRCA1 and BRCA2 in a male breast cancer population.

A population-based series of 54 male breast cancer cases from Southern California were analyzed for germ-line mutations in the inherited breast/ovarian cancer genes, BRCA1 and BRCA2. Nine (17%) of the patients had a family history of breast and/or ovarian cancer in at least one first-degree relative. A further seven (13%) of the patients reported breast/ovarian cancer in at least one second-degree relative and in no first-degree relatives. No germ-line BRCA1 mutations were found. Two male breast cancer patients (4% of the total) were found to carry novel truncating mutations in the BRCA2 gene. Only one of the two male breast cancer patients carrying a BRCA2 mutation had a family history of cancer, with one case of ovarian cancer in a first-degree relative. The remaining eight cases (89%) of male breast cancer with a family history of breast/ovarian cancer in first-degree relatives remain unaccounted for by mutations in either the BRCA1 gene or the BRCA2 gene.

Aged↗
PubMed1996

Superoxide and hydrogen peroxide induce CD18-mediated adhesion in the postischemic heart.

A burst of endothelial derived oxidants including hydrogen peroxide (H2O2) and superoxide (.O2-) occurs on reperfusion of ischemic tissues that directly causes injury; however, it is not known if this also triggers further injury due to subsequent leukocyte adhesion and adhesion molecule expression. Therefore, studies were performed in an isolated heart model developed to enable study of the role of isolated cellular and humoral factors in the mechanism of postischemic injury. Isolated rat hearts were subjected to 20 min of 37 degrees C-global ischemia followed by reperfusion with polymorphonuclear leukocytes (PMNs) and plasma in the presence or absence of superoxide dismutase (SOD), 200 U/ml, or catalase, 500 U/ml. Measurements of contractile function, coronary flow, high-energy phosphates, free radical generation, and PMN accumulation were performed. Adhesion molecule expression was measured on the surface of effluent PMNs by fluorescence flow cytometry and within the tissue using immunohistochemistry. SOD or catalase treatment resulted in 2- to 3-fold higher recoveries of contractile function, coronary flow, and high energy phosphates. EPR spin trapping measurements demonstrated that SOD totally quenched the free radical generation observed upon reperfusion while catalase prevented the formation of hydroxyl and alkyl radicals derived from superoxide. SOD or catalase treatment decreased PMN accumulation in the reperfused heart and prevented the marked upregulation of CD18 expression seen after reperfusion. These experiments demonstrate that in addition to their direct antioxidative actions, SOD and catalase each decrease PMN adhesion and CD18 expression resulting in marked suppression of PMN-mediated injury in the postischemic heart. Thus, endothelial derived H2O2 and .O2- further amplify postischemic injury by triggering CD18 expression on the surface of PMNs leading to increased PMN adhesion within the heart.

Animals↗
PubMed1996

BRCA1 R841W: a strong candidate for a common mutation with moderate phenotype.

BRCA1 mutations cause increased risk for breast and ovarian cancer, frequently of early onset. Many different mutations occur in BRCA1, including several examples of recurrent mutations, each of which accounts for a significant number of families with heritable cancer predisposition. These common mutations have an etiological role in many breast and ovarian cancer cases and provide the opportunity to examine genotype-phenotype correlations and genotype-environment interactions in individuals with the identical BRCA1 lesion. We report a novel missense change in BRCA1, 2640 C-->T (R841W), found in 3 cases from a subject group of 305 breast and 79 ovarian cancer cases from Orange County, CA. These are consecutive, population-based cases not selected for age or family history. In all three cases, there is a strong family history of breast, ovarian, or other cancers possibly related to a BRCA1 defect and family members showed a high concordance of cancer incidence with the presence of R841W. The age of cancer onset was not always distinct from typical sporadic cases. Testing of a sample of 413 unrelated individuals to examine the hypothesis that R841W might be a rare polymorphism detected one additional instance in a woman with breast cancer diagnosed at age 77 years, and cancer in one parent. R841W is likely to be an etiologically significant lesion with involvement in close to 1% (95% confidence interval of 0-1.7%) of all breast and ovarian cancers in this population.

Adult↗
PubMed1996

Monocyte chemoattractant protein-1 in chronic proliferative immune complex nephritis.

In rats with chronic serum sickness, proliferative immune complex glomerulonephritis progresses in three discrete stages, designated mild, moderate, and severe. One distinguishing immunopathologic feature, the progressive increase in the number of glomerular macrophages, is closely correlated with decreasing kidney function. We hypothesized that monocyte chemoattractant protein-1, a beta-subfamily chemokine with potent monocyte-specific chemotactic activity, might contribute to this macrophage accumulation. Immunohistochemical methods were used to identify monocyte chemoattractant protein-1 in kidney tissue sections. Total RNA was extracted from the kidneys of rats at each stage of chronic serum sickness, and age-matched controls, and Northern blot analysis was performed with a rat monocyte chemoattractant protein-1 cDNA probe. Tissue staining localized monocyte chemoattractant protein-1 to the glomerular capillary wall and mesangium in chronic serum sickness. Minimal quantities of monocyte chemoattractant protein-1 mRNA were detected in the kidneys of normal control rats, with marked increases in mRNA as chronic serum sickness nephritis progressed to the moderate stage. There was then an apparent decrease in monocyte chemoattractant protein-1 mRNA in the severe stage. The degree of protein staining and mRNA levels paralleled each other. We conclude that monocyte chemoattractant protein-1 is a potentially important chemotactic agent in chronic serum sickness nephritis.

Animals↗
PubMed1996

pH dependence of neutrophil-endothelial cell adhesion and adhesion molecule expression.

Neutrophil adhesion to the vascular endothelium is enhanced during tissue ischemia and/or inflammation, conditions that are associated with tissue acidosis. This study examined the effects of hypercarbic acidosis (10 or 20% CO2) and of hypocarbic alkalosis (0% CO2) on human neutrophil CD18 and human aortic endothelial cell intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin expression quantified by flow cytometry. Acidosis with 20% CO2 for 4 h decreased ICAM-1 to 60.6 +/- 9.7% of control. In contrast, alkalosis with 0% CO2 for 4 h enhanced ICAM-1 expression to 143.8 +/- 10.1% of control. There was no pH dependence of VCAM-1 or E-selectin expression. Tumor necrosis factor-alpha (TNF-alpha; 10 ng/ml) increased endothelial ICAM-1, E-selectin, and VCAM-1; under these conditions, acidosis with 20% CO2 blunted both ICAM-1 and E-selectin surface expression compared with 5% CO2-, TNF-alpha-treated cells. Hypercarbic acidosis with 20% CO2 increased neutrophil CD18 expression and enhanced neutrophil adhesion. This latter effect was inhibited by neutrophil pretreatment with an anti-CD18 monoclonal antibody. In contrast, when only endothelial cells were preincubated with the hypercarbic buffer, neutrophil adhesion diminished to 55.6 +/- 7.8% of control. The results suggest that acidosis generated during tissue ischemia/inflammation may induce CD18-mediated neutrophil adhesion despite a decrease in ICAM-1 expression.

Cell Adhesion↗
PubMed1996

Microanatomical distribution of dendritic cells in normal tonsils.

Lymphoid dendritic cells play an essential role in antigen presentation in primary immune responses and are believed to be important in normal healthy responses of the mucosal immune system. The microanatomical distribution of HLA-DR-positive/S100 antigen-positive dendritic cells was analyzed in 10 normal palatine tonsils. Tonsil biopsies were obtained from 8 normal children undergoing otolaryngological surgery for reasons completely unrelated to tonsil disease. Two samples of normal adult tonsil were also obtained. Standard immunohistochemical methods, with antigen retrieval, were used to detect cell surface markers in formalin-fixed and/or frozen tissue specimens. The clinical identification of these tonsils as normal was confirmed by their microscopic appearance. HLA-DR antigen expression was restricted to lymphocytes, macrophages and dendritic cells; all normal epithelia were negative. S100-positive dendritic cells were readily detected in surface and crypt epithelium and were rare in submucosal sites or follicles. T cells were observed as frequently as dendritic cells in epithelial sites. Dendritic cell density was highest in extrafollicular T cell areas, where CD4-positive lymphocytes were especially abundant. A significant correlation was observed between the total number of different bacterial species isolated from individual normal tonsils and the frequency of dendritic cells in both the crypt epithelium and extrafollicular T cell areas. The number of dendritic cells at the tonsil surface was not similarly related to the bacterial flora.

Child↗
PubMed1996

The role of dendritic cells in the development of chronic tonsillar disease in children.

Thirty-one children, 2.6-12.2 years (mean = 7.9 +/- 5.0) were divided into four clinical categories: normal controls (n = 7), recurrent tonsillitis (n = 8), idiopathic tonsillar hyperplasia (n = 9) and recurrent tonsillitis with hyperplasia (n = 7). Immunohistopathologic studies were performed to determine the presence and location of HLA-DR, S-100 positive antigen presenting dendritic cells (DCs) in six microanatomic compartments: surface and crypt epithelium and submucosae, extrafollicular areas and lymphoid follicles. The results were analyzed in the context of the clinical history, bacteriology, and routine histopathology. The distribution of DCs was altered significantly with disease fewer numbers of DCs were found in the surface epithelium and greater numbers in the crypts and extrafollicular areas, than in normals, p <0.01. The surface : crypt ratio of DCs was 1:1 for normal tonsils, but dropped to 1:3 in disease. Chronic cryptitis was more common in disease and correlated strongly to the presence of beta-lactamase producing microorganisms (R = 1.0). An increased total bacterial concentration was correlated with increased numbers of DCs in the surface epithelium (R = 0.5, p <0.009). In summary, the microanatomical distribution of DCs within the tonsil is significantly altered in disease. These alterations appear to be influenced by potentially pathogenic bacteria more often found in the crypts of abnormal tonsils.

Adenoids↗
PubMed1995

Mononuclear cells in salivary glands of normal and isoproterenol-treated rats.

The purpose of this study was to analyse the phenotypical distribution of resident cells of the mononuclear phagocyte system in rat salivary glands, and to determine whether isoproterenol induces alterations in macrophage and lymphocyte surface-marker expression. Frozen sections of gland tissues were prepared from five normal rats, and from six rats treated with 20 mg/kg isoproterenol/day for 10 days. A panel of six monoclonal antibodies was used to identify membrane markers associated primarily with monocytes (ED1), mature tissue macrophages (ED2), lymphoid macrophages (ED3), MHC class II (Ia) antigens (OX6), CD5-positive T lymphocytes (OX19), and rat B lymphocytes (OX33). Double-labelling techniques were used to detect the coexpression of ED1/ED2 and OX6/ED2 mononuclear cell markers in the major salivary glands. ED2-positive macrophages were predominant in all three major glands, ranging from 96 cells/0.87 mm2 field in the parotid gland to 165 cells/0.87 mm2 in the submandibular. OX19-positive T lymphocytes were rarely observed in submandibular and parotid glands but represented a distinguishing feature of the sublingual. Moderate numbers of ED3-positive macrophages also were detected in sublingual tissues. In the submandibular and parotid glands, isoproterenol resulted in a decrease in ED2-positive cells, but ED2-positive macrophages increased in sublingual glands with isoproterenol. Isoproterenol resulted in a decrease in MHC class II antigen expression on submandibular and sublingual mononuclear cells but an induction of Ia antigen in the parotid gland. Double labelling revealed that isoproterenol induced coexpression of ED1/ED2 markers on mononuclear cells in the submandibular glands, but ED1/ED2-positive cells were absent from other glands. However, coexpression of MHC class II markers on ED2-positive cells in the sublingual and parotid glands of normal rats was frequently observed, with isoproterenol decreasing coexpression in the sublingual gland and increasing it in the parotid. B lymphocytes were not detected in any of the glands examined. These findings indicate that important differences exist in normal resident mononuclear cell subsets among the major salivary glands of the rat. The differential effects of isoproterenol on inflammatory cells may reflect important differences in local salivary gland immunoregulation. Although salivary gland inflammation induced by isoproterenol does not appear to result from immune mechanisms, the rich population of T lymphocytes and ED3-positive macrophages, and presence of MHC class II antigens, suggest that the sublingual gland may function as an immune organ and have a role in mucosal immunity.

Adrenergic beta-Agonists↗
PubMed1995

Role of allergy in nasal polyposis: a review.

We propose a multivariate theory for the pathogenesis of nasal polyps. Turbulent flow of air in the lateral wall of the nose or viral-bacterial-host interactions produce an inflammatory change in the mucosa of the lateral wall of the nose. Ulceration and prolapse of the submucosa with reepithelialization and new gland formation may then follow. The structural cells of the nasal polyp, including epithelial cells and fibroblasts, have the ability to produce messenger RNA for granulocyte-monocyte colony-stimulating factor and other cytokines. Stimulation of such an effector capability by structural cell-derived cytokines would undoubtedly represent a major amplification pathway of the inflammatory response in nasal polyps. Allergy may be one mechanism for the development of this cascade of events. This microenvironmental structural inflammatory response in the nasal polyp, in turn, can affect the bioelectric integrity of the Na+ and Cl- channels at the luminal surface of the respiratory epithelial cell. The change in the Na+ absorption, which has been demonstrated in our studies, may result in an increased movement of water into the cell and into the interstitial fluid. The resultant edema can lead to growth and enlargement of the nasal polyp. Finally, the rapid recurrence of nasal polyps despite adequate surgery may reflect some intrinsic phenotypic characteristic of nasal epithelial cells in the lateral wall of the nose, which is likely to be under genetic control.

Epithelium↗
PubMed1994

Glomerular macrophage phagocytic activity in experimental immune complex nephritis.

In rats with the proliferative immune complex glomerulonephritis of chronic serum sickness, kidney function deteriorates in three clearly distinguishable and discrete stages: mild, moderate and severe. The macrophage component of glomerular inflammation in each stage is also quantitatively and qualitatively distinct, with abnormal phenotypic markers appearing in the moderate stage and increasing in the severe stage. To determine whether there were distinct functional differences among macrophages from the three stages, Fc gamma receptor-mediated phagocytic capacity was measured. The phagocytic capacity of glomerular macrophages increased significantly in the moderate stage, then significantly decreased, as rats progressed to severe chronic serum sickness. This decline in phagocytic function was not associated with a decrease in the expression of Fc gamma receptors on the glomerular macrophage cell surface. Furthermore, the phagocytic function of peritoneal macrophages from rats with severe chronic serum sickness was not impaired. Whether or not this attenuation of glomerular macrophage phagocytic capacity is the cause, or result, of renal disease progression remains unclear. It may indicate a potentially protective role for intraglomerular macrophages, and can serve as an additional functional marker of disease progression.

Animals↗
PubMed1994

Phenotypic characterization of mononuclear cells following anorganic bovine bone implantation in rats.

The purpose of this study was to measure inflammatory changes associated with implantation of anorganic bovine bone and bovine bone/collagen composite grafts, and to compare the response to that obtained following grafting with hydroxyapatite. Anorganic bovine bone, either with or without bovine collagen, as well as granular and block forms of synthetic hydroxyapatite, were implanted subcutaneously in Wistar rats. Saline and turpentine oil were used as controls. Biopsies were obtained after 3 days and at 1, 2, 4, 6, and 8 weeks. A panel of 6 monoclonal antibodies was used to detect monocytes, several distinct macrophage subsets, Ia-antigen expression, and T- and B-lymphocytes. Cells identified by each antibody were counted after immunocytochemical staining, and sera obtained 6 weeks after grafting were used in immunoblotting assays to detect antibodies to bovine serum proteins and collagen. Anorganic bovine bone, bovine bone/collagen, and hydroxyapatite all produced a transient macrophage infiltrate that was maximum 3 days after implantation, but resolved to normal levels within 6 to 8 weeks. Lymphocyte infiltration was not elicited by any bovine graft material, and antibodies to bovine serum proteins or type I collagen were not detected in any of the animals examined. These data indicate that a systemic or local immune response does not develop following implantation with anorganic bovine bone or with anorganic bovine bone/collagen materials. It appears appropriate to explore further the merits of these materials for periodontal regenerative procedures.

Analysis of Variance↗
PubMed1994

A germline 2.35 kb deletion of p53 genomic DNA creating a specific loss of the oligomerization domain inherited in a Li-Fraumeni syndrome family.

The primary genetic cancer predisposing event in many Li-Fraumeni syndrome families is a germline mutation in the p53 gene. We describe an extended Li-Fraumeni family with a germline mutation in the p53 gene involving a deletion of exon 10. The mutation is a 2.35 kilobase intragenic deletion encompassing exon 10, which results in the specific loss of the entire p53 oligomerization domain. This mutation segregates with the cancer phenotype. A lymphoblastoid cell line developed from a mutation carrier shows accumulation of mutant p53 protein by immunoblotting. However, tumor tissues from two affected carriers are negative by immunohistochemical staining. A major structural alteration specifically involving the oligomerization domain of a germline p53 gene has not been previously described and occurs in a region rarely mutated in sporadic tumors. The oligomerization domain is dispensable for many wild-type p53 functions, including transactivation, sequence-specific DNA binding, and suppression of oncogenic transformation. However, the domain appears to be required for transcriptional repression, and DNA strand reassociation. The identification of this mutation in an LFS family may yield insights into the importance of the oligomerization domain for suppressor function of the p53 tumor suppressor gene.

Base Sequence↗
PubMed1994

Combination of cyclosporine and splenectomy suppresses interleukin-6 production and major histocompatibility complex class II expression and prolongs cardiac xenograft survival.

Although untreated Lewis rat recipients will reject a transplanted hamster heart in 3 days, accommodation of heart xenografts can be induced by treatment with cyclosporine and splenectomy, improving graft survival to greater than 50 days. Both humoral and cellular arms of the immune system may be involved in the mechanisms responsible for the prolongation of graft survival. Our objective was to study the impact of cyclosporine and splenectomy on the deposition of antibodies, complement, or both within the graft. We also compared the cellular component of inflammation in treated recipients with that in untreated controls. Inbred male Lewis rats given cyclosporine 15 mg/kg per day were splenectomized 2 days after they had received heterotopic heart transplants from Golden Syrian hamsters. Recipients of syngeneic grafts or untreated xenografts served as controls. Plasma interleukin-6 activity was measured in a standard proliferation assay with 7TD1 hybridoma cells. Deposition of immunoglobulin M, immunoglobulin G, and complement in heart tissue was evaluated by immunofluorescence. Cells infiltrating the graft that expressed major histocompatibility complex class II antigens were identified by immunohistochemical staining with OX6 antibodies. In xenograft recipients receiving immunosuppression, interleukin-6 activity, immunoglobulin M and complement deposition were significantly reduced, graft infiltration was mild, and cardiac function was good compared with the results in those without treatment 3 and 10 days after implantation. Inflammatory cells expressing major histocompatibility complex class II antigens were significantly reduced in immunosuppressed xenograft recipients (2.8 +/- 0.4 cells/high power field) compared with those in xenogeneic controls (9.5 +/- 0.6 cells/high power field; p < 0.0005). The significant decrease in deposition of humoral components (immunoglobulin M and complement), interleukin-6 plasma levels, and expression of major histocompatibility complex class II antigens by inflammatory cells within the nonrejecting grafts suggests that the synergistic benefit of cyclosporine and splenectomy depends on the attenuation of both cellular and humoral mechanisms of xenograft rejection.

Animals↗
PubMed1993

The effect of cyclosporin A on disease progression in proliferative immune complex glomerulonephritis.

In rats with the proliferative immune complex glomerulonephritis of chronic serum sickness, kidney function deteriorates in three discrete and readily distinguishable stages: Mild, Moderate, and Severe. The mononuclear cell composition of glomerular inflammation is also different in each stage. The immunosuppressive drug, cyclosporin A, was administered to rats with chronic serum sickness in order to investigate the relationship between glomerular immunopathology and pathophysiology in proliferative immune complex nephritis. When introduced after the onset of proteinuria, daily treatment with cyclosporin A failed to prevent the progression from Moderate to Severe nephritis, which is characterized by the abnormal differentiation and local proliferation of glomerular macrophages, as well as grave deterioration in kidney function. In contrast, when cyclosporin A therapy started before the onset of proteinuria, the course of proliferative glomerulonephritis was altered significantly. Although the levels of proteinuria and macrophage accumulation that are characteristic of the Moderate stage of nephritis were not reduced, progression to Severe nephritis did not occur. The number of glomerular macrophages appeared to increase in two separate phases in this chronic serum sickness model of proliferative immune complex glomerulonephritis. The first phase, which coincided with the onset of proteinuria, did not require T cells and culminated only in moderate hypercellularity and proteinuria. The second increase in the number of glomerular macrophages, which was accompanied by the expression of abnormal macrophage phenotypes, was closely linked to the development of severe kidney insufficiency. The protective effect of cyclosporin A therapy was consistent with, although not conclusive proof for, the hypothesis that local T cell activation may contribute to the progression of proliferative immune complex glomerulonephritis. Since cyclosporin A can also directly influence the responses of macrophages and mesangial cells, the effect of the drug on the course of nephritis in this model might not be related to its immunosuppressive action.

Animals↗
PubMed1993

The effect of dorsomedial hypothalamic nucleus lesions on kidney function and structure after 1 and 12 months.

According to the Dillman theory (17), aging results from a deterioration of metabolism that begins with an elevation of hypothalamic receptor thresholds for feedback signals from the periphery. Three hypothalamic areas are known to contain such receptors: the ventromedial and dorsomedial hypothalamic nuclei (DMN) and the lateral hypothalamic area. We have hypothesized that selective destruction of those hypothalamic areas might be followed by physiological changes associated with aging. Electrolytic bilateral DMN lesions were produced in male and female weanling rats. These rats were maintained for up to 13 months of age. Sham-operated rats served as controls. Food intake and body weight were monitored postoperatively and prior to sacrifice. Before sacrifice, tail blood and a 24-h urine samples were obtained. In accordance with previous findings, rats with DMN lesions showed dramatic reductions of ponderal growth and food intake but had normal body composition. Total protein and albumin excretion rates were significantly lower in rats with lesions. The fractional contribution of albumin to total urinary protein was also decreased in rats with lesions. Histological examination of the kidneys showed significantly less pathology in the kidneys of rats with DMN lesions; the severity of renal pathology was correlated directly with proteinuria. These changes were seen as early as 1 month after production of the lesion. The attenuation of age-related changes in kidney functions and structure in rats with lesions could be due to reduced food intake (dietary restriction is known to produce similar results), and/or a direct effect of the lesion.(ABSTRACT TRUNCATED AT 250 WORDS)

Afferent Pathways↗