scholarly journals Parathyroid hormone inhibits B cell proliferation: implications in chronic renal failure.

1990 ◽  
Vol 1 (3) ◽  
pp. 236-244
Author(s):  
J M Alexiewicz ◽  
M Klinger ◽  
T O Pitts ◽  
Z Gaciong ◽  
M Linker-Israeli ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Renal Failure ◽  
Parathyroid Hormone ◽  
Chronic Renal Failure ◽  
B Cells ◽  
B Cell ◽  
Normal Subjects ◽  
Dependent Manner ◽  
Dialysis Patients ◽  
Amino Terminal

B cell proliferation is impaired in patients with chronic renal failure, but the mechanisms underlying this defect are not known. Lymphocytes have receptors for parathyroid hormone, and it is possible that the state of secondary hyperparathyroidism of renal failure is responsible for the B cell defect. Our studies were designed to (a) examine T cell-independent B cell proliferation [3H)thymidine incorporation) induced by Staphylococcus aureus Cowan 1 after 5 days of culture, (b) evaluate the effect of parathyroid hormone on S. aureus Cowan I-induced B cell proliferation, and (c) investigate the mechanisms through which parathyroid hormone may exert its effect on B cell proliferation. Lymphocytes were obtained from 37 normal subjects and 21 dialysis patients. S. aureus Cowan I induced significant stimulation (P less than 0.01) of the proliferation of B cells from both groups, but the effect was smaller on B cells from dialysis patients (10.0 x 10(3) +/- 1.4 x 10(3) cpm) than on those from normal subjects (21.8 x 10(3) +/- 2.0 x 10(3) cpm). Both the intact molecule of parathyroid hormone (1-84 PTH) and its amino-terminal fragment (1-34 PTH) caused significant inhibition of proliferation of B cells from normal subjects in a dose-dependent manner, with the effect being significantly greater (P less than 0.01) with an equimolar concentration of 1-84 PTH than that of 1-34 PTH. Inactivation of 1-84 PTH by oxidation abolished most of its inhibitory effect on B cell proliferation.(ABSTRACT TRUNCATED AT 250 WORDS)

Distribution of Circulating Immunoreactive Components of Parathyroid Hormone in Normal Subjects and in Patients with Primary and Secondary Hyperparathyroidism: The Role of the Kidney and of the Serum Calcium Concentration

1979 ◽  
Vol 57 (5) ◽  
pp. 435-443 ◽  
Author(s):  
M. A. Dambacher ◽  
J. A. Fischer ◽  
W. H. Hunziker ◽  
W. Born ◽  
J. Moran ◽  
...  
Keyword(s):  
Vitamin D ◽  
Renal Failure ◽  
Parathyroid Hormone ◽  
Chronic Renal Failure ◽  
Primary Hyperparathyroidism ◽  
Vitamin D Deficiency ◽  
Normal Subjects ◽  
Dependent Manner ◽  
Intact Pth ◽  
Calcium Dependent

1. The distribution of intact parathyroid hormone-(1–84) [PTH-(1–84)] and of its COOH-terminal fragments was determined in human serum by column chromatography. In addition to PTH-(1–84) (peak I), COOH-terminal fragments having molecular weights of approximately 4000–7000 (peak II) and immunoreactive components co-eluting with human PTH-(1–12) (peak III) were observed. 2. Mean concentrations of intact PTH-(1–84) and of its COOH-terminal fragments were significantly raised in chronic renal failure as compared with those of normal subjects. Mean amounts of peak II were higher in patients with chronic renal insufficiency than in nutritional vitamin D deficiency, in pseudohypoparathyroidism and in primary hyperparathyroidism, despite comparable amounts of PTH-(1–84). 3. In chronic renal failure as well as in a group of patients with vitamin D deficiency, pseudohypoparathyroidism and primary hyperparathyroidism and in controls, significant linear relations were found between the serum concentrations of calcium and log (peak II/peak I). Our findings suggest that the conversion of intact PTH-(1–84) into COOH-terminal fragments by the parathyroid glands (resulting in a raised secretion of fragments) and/or in peripheral organs may be directly related to the serum concentration of calcium. However, the degradation of the fragments may also be suppressed in a calcium-dependent manner.

Parathyroid hormone metabolism and its potential as a uremic toxin

1980 ◽  
Vol 239 (1) ◽  
pp. F1-F12 ◽  
Author(s):  
E. Slatopolsky ◽  
K. Martin ◽  
K. Hruska
Keyword(s):  
Renal Failure ◽  
Parathyroid Hormone ◽  
Chronic Renal Failure ◽  
Biological Effects ◽  
Uremic Toxin ◽  
Terminal Portion ◽  
Single Chain ◽  
Biochemical Alterations ◽  
Amino Terminal ◽  
Carboxy Terminal

Secondary hyperparathyroidism is a universal complication of chronic renal failure. It has been proposed that the markedly elevated levels of immunoreactive parathyroid hormone (i-PTH) in uremia may represent a “uremic toxin” responsible for many of the abnormalities of the uremic state. Plasma i-PTH consists of a mixture of intact hormone, a single-chain polypeptide of 84 amino acids, and smaller molecular weight hormonal fragments from both the carboxy- and amino-terminal portion of the PTH molecule. The hormonal fragments arise from metabolism of intact PTH by peripheral organs as well as from secretion of fragments from the parathyroid glands. The structural requirements for the known biological actions of PTH reside in the amino-terminal portion of the PTH molecule. Carboxy-terminal fragments, biologically inactive at least in terms of adenylate cyclase activation, hypercalcemia, or phosphaturia, depend on the kidney for their removal from plasma, and thus accumulate in the circulation in chronic renal failure. It is unknown at the present time if other biological effects of these carboxy-terminal fragments may contribute to some of the biochemical alterations observed in uremia. The most significant consequence of increased PTH levels in uremia is the development of bone disease characterized by osteitis fibrosa. In addition, it would appear that PTH plays an important role in some of the abnormal electroencephalographic patterns observed in uremia. This may be due to a potential role of PTH in increasing calcium content of brain. Parathyroid hormone also has been implicated as a pathogenetic factor in many other alterations present in uremia, i.e., peripheral neuropathy, carbohydrate intolerance, hyperlipidemia, and other alterations. Unfortunately, outstanding clinical research is lacking in this field and conclusive experimental data are practically nonexistent. Further studies are necessary if one is to accept the concept of PTH being a significant “uremic toxin.”

Parathyrin radioimmunoassay: diagnostic utility of antisera produced against carboxyl-terminal fragments of the hormone from the human.

1978 ◽  
Vol 24 (3) ◽  
pp. 451-454 ◽  
Author(s):  
F P Di Bella ◽  
J M Kehrwald ◽  
K Laakso ◽  
L Zitzner
Keyword(s):  
Renal Failure ◽  
Parathyroid Hormone ◽  
Chronic Renal Failure ◽  
Guinea Pigs ◽  
Normal Subjects ◽  
Terminal Region ◽  
Diagnostic Utility ◽  
Human Origin ◽  
Widespread Availability ◽  
Carboxyl Terminal

Abstract Antisera directed toward the carboxyl-terminal region of human parathyrin (parathyroid hormone), for use in daignostically applicable radioimmunoassays of the hormone in serum, are scarce, largely because of the lack of suitable immunogens of human origin. We produced four antisera in goats and guinea pigs by immunization with recently discovered carboxyl-terminal fragments of human parathyrin extracted from parathyroid tumors. Here, we report results of radioimmunoassays of nearly 200 normal and pathological sera with one of these antisera; we observed almost complete differentiation between concentrations of parathyrin in serum of healthy normal subjects and patients with primary, secondary (due to chronic renal failure), or "ectopic" hyperparathyroidism (due to nonparathyroid cancer). The availability of a new immunogen should now make possible the deliberate production of large quantities of diagnostically applicable parathyrin antisera directed toward the carboxyl-terminal region of human parathyrin. This should, in turn, lead to more widespread availability of this useful radioimmunoassay.

scholarly journals Activated CD4+CD25+ T cells selectively kill B lymphocytes

Blood ◽  
2006 ◽  
Vol 107 (10) ◽  
pp. 3925-3932 ◽  
Author(s):  
Dong-Mei Zhao ◽  
Angela M. Thornton ◽  
Richard J. DiPaolo ◽  
Ethan M. Shevach
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
Cell Death ◽  
B Cells ◽  
B Cell ◽  
T Cell Activation ◽  
Fas Ligand ◽  
Cell Function ◽  
Cell Contact ◽  
Dependent Manner

The suppressive capacity of naturally occurring mouse CD4+CD25+ T cells on T-cell activation has been well documented. The present study is focused on the interaction of CD4+CD25+ T cells and B cells. By coculturing preactivated CD4+CD25+ T cells with B cells in the presence of polyclonal B-cell activators, we found that B-cell proliferation was significantly suppressed. The suppression of B-cell proliferation was due to increased cell death caused by the CD4+CD25+ T cells in a cell-contact–dependent manner. The induction of B-cell death is not mediated by Fas–Fas ligand pathway, but surprisingly, depends on the up-regulation of perforin and granzymes in the CD4+CD25+ T cells. Furthermore, activated CD4+CD25+ T cells preferentially killed antigen-presenting but not bystander B cells. Our results demonstrate that CD4+CD25+ T cells can act directly on B cells and suggest that the prevention of autoimmunity by CD4+CD25+ T cells can be explained, at least in part, by the direct regulation of B-cell function.

scholarly journals Modulation of B-Cell Proliferative Response by a Soluble Extract of Nippostrongylus brasiliensis

2000 ◽  
Vol 68 (11) ◽  
pp. 6154-6161 ◽  
Author(s):  
Humphrey N. Ehigiator ◽  
Andrew W. Stadnyk ◽  
Timothy D. G. Lee
Keyword(s):  
Cell Proliferation ◽  
B Cells ◽  
B Cell ◽  
Inhibitory Activity ◽  
Accessory Cell ◽  
Nippostrongylus Brasiliensis ◽  
Dependent Manner ◽  
Soluble Extract ◽  
Present Evidence ◽  
Accessory Cells

ABSTRACT We and others have previously shown that nematodes or nematode products can stimulate or inhibit the generation of lymphocyte responses, suggesting that nematodes exert diverse effects on the developing immune responses of their host. In this study we examined the immunomodulatory effect of a soluble extract ofNippostrongylus brasiliensis (adult worm homogenate [AWH]) on B-cell responsiveness. We found that the extract inhibited the proliferation of B cells to lipopolysaccharide (LPS) stimulation in a dose-dependent manner. This effect was specific to B cells, since the extract did not inhibit T-cell proliferation to concanavalin A or anti-CD3 stimulation. The data presented here confirm that the extract is not toxic to B cells. We present evidence that the active factor is proteinaceous in nature and that the inhibitory activity is restricted to the adult stage of Nb. The extract does not appear to interfere with early activation events since it can be added up to 48 h after LPS stimulation, and it inhibited responses to phorbol myristate acetate and ionomycin. Furthermore, the proliferation of B cells to other activators was also inhibited by AWH. This observation shows that the inhibitory activity of AWH is not restricted to LPS-mediated B-cell proliferation. We present evidence that, in the absence of accessory cells, the inhibitory effect of the extract was ablated. This observation shows that the activity of AWH is not mediated directly on B cells but is mediated via the production of negative signals from accessory cells (macrophages), which affect a downstream pathway required by all B-cell activators tested. These effects on B-cell and accessory cell function are likely to have a significant effect on the outcome of infections experienced concurrently.

Evidence for an Increased Generation of Prostacyclin in the Microvasculature and an Impairment of the Platelet α-Granule Release in Chronic Renal Failure

1988 ◽  
Vol 60 (02) ◽  
pp. 205-208 ◽  
Author(s):  
Paul A Kyrle ◽  
Felix Stockenhuber ◽  
Brigitte Brenner ◽  
Heinz Gössinger ◽  
Christian Korninger ◽  
...  
Keyword(s):  
Renal Failure ◽  
Chronic Renal Failure ◽  
Blood Clotting ◽  
Normal Subjects ◽  
Chronic Uraemia ◽  
Wall Interaction ◽  
End Stage ◽  
Granule Release

SummaryThe formation of prostacyclin (PGI2) and thromboxane A2 and the release of beta-thromboglobulin (beta-TG) at the site of platelet-vessel wall interaction, i.e. in blood emerging from a standardized injury of the micro vasculature made to determine bleeding time, was studied in patients with end-stage chronic renal failure undergoing regular haemodialysis and in normal subjects. In the uraemic patients, levels of 6-keto-prostaglandin F1α (6-keto-PGF1α) were 1.3-fold to 6.3-fold higher than the corresponding values in the control subjects indicating an increased PGI2 formation in chronic uraemia. Formation of thromboxane B2 (TxB2) at the site of plug formation in vivo and during whole blood clotting in vitro was similar in the uraemic subjects and in the normals excluding a major defect in platelet prostaglandin metabolism in chronic renal failure. Significantly smaller amounts of beta-TG were found in blood obtained from the site of vascular injury as well as after in vitro blood clotting in patients with chronic renal failure indicating an impairment of the a-granule release in chronic uraemia. We therefore conclude that the haemorrhagic diathesis commonly seen in patients with chronic renal failure is - at least partially - due to an acquired defect of the platelet a-granule release and an increased generation of PGI2 in the micro vasculature.

METABOLIC SYNDROME IN DIALYSIS PATIENTS

2016 ◽  
pp. 7-11
Author(s):  
Vinh Phu Hoang ◽  
Tam Vo ◽  
Van Tien Le ◽  
Thi Hoai Huong Vo
Keyword(s):  
Blood Pressure ◽  
Metabolic Syndrome ◽  
Renal Failure ◽  
Chronic Renal Failure ◽  
Artificial Kidney ◽  
Dialysis Patients ◽  
Cross Sectional ◽  
Average Value ◽  
The Metabolic Syndrome ◽  
End Stage

Objective: To review disorders elements of the metabolic syndrome in patients with end-stage chronic renal failure on dialysis cycle. Materials and methods: A cross sectional descriptive study of 85 patients including end-stage chronic renal failure in dialysis cycle from 5/2015 - 9/2016 at the Department of Artificial Kidney, Hue Central Hospital. Results: The prevalence of metabolic syndrome in dialysis patients was 37.65%. The prevalence of abdominal obesity was 30.6%; The prevalence of hypertension was 72.9%, the average value systolic blood pressure and diastolic blood pressure were 142.24 ± 27.53, 80.35 ± 12.48 mmHg; The prevalence of hyperglycemia was 28%, the average value blood glucose was 4.9 ± 1.19 mmol/l; The prevalence of triglyceride increase was 34.1%, the average value triglyceride was 1.59 ± 0.84 mmol/l. The prevalence of HDL-C increase was 47.1%, the average value HDL-C was 1.24 ± 0.33 mmol/l. Conclusion: The prevalence of metabolic syndrome in dialysis patients is very high, in which hypertension and HDL disturbances are the highest. Key words: chronic renal failure, dialysis, metabolic syndrome

scholarly journals Role of parathyroid hormone in the glucose intolerance of chronic renal failure.

1985 ◽  
Vol 75 (3) ◽  
pp. 1037-1044 ◽  
Author(s):  
M Akmal ◽  
S G Massry ◽  
D A Goldstein ◽  
P Fanti ◽  
A Weisz ◽  
...  
Keyword(s):  
Renal Failure ◽  
Parathyroid Hormone ◽  
Chronic Renal Failure ◽  
Glucose Intolerance

scholarly journals Parathyroid hormone secretion in chronic renal failure

1996 ◽  
Vol 50 (5) ◽  
pp. 1700-1705 ◽  
Author(s):  
Jesper C. Madsen ◽  
Anne Q. Rasmussen ◽  
Søren D. Ladefoged ◽  
Peter Schwarz
Keyword(s):  
Renal Failure ◽  
Parathyroid Hormone ◽  
Chronic Renal Failure ◽  
Hormone Secretion

Antibody Production Remains Intact Despite Loss of Bone Marrow B cells in Murine Norovirus Infected Stat1−/− Mice

2021 ◽  
Author(s):  
Daniel E Eldridge ◽  
Charlie C Hsu
Keyword(s):  
Bone Marrow ◽  
B Cells ◽  
B Cell ◽  
Cell Loss ◽  
Dependent Manner ◽  
Intestinal Epithelial ◽  
Murine Norovirus ◽  
Laboratory Mice ◽  
T And B Cells ◽  
Humoral Immune

Murine norovirus (MNV), which can be used as a model system to study human noroviruses, can infect macrophages/monocytes, neutrophils, dendritic, intestinal epithelial, T and B cells, and is highly prevalent in laboratory mice. We previouslyshowed that MNV infection significantly reduces bone marrow B cell populations in a Stat1-dependent manner. We show here that while MNV-infected Stat1−/− mice have significant losses of bone marrow B cells, splenic B cells capable of mounting an antibody response to novel antigens retain the ability to expand. We also investigated whether increased granulopoiesis after MNV infection was causing B cell loss. We found that administration of anti-G-CSF antibody inhibits the pronounced bone marrow granulopoiesis induced by MNV infection of Stat1−/− mice, but this inhibition did not rescue bone marrow B cell losses. Therefore, MNV-infected Stat1−/− mice can still mount a robust humoral immune response despite decreased bone marrow B cells. This suggests that further investigation will be needed to identify other indirect factors or mechanisms that are responsible for the bone marrow B cell losses seen after MNV infection. In addition, this work contributes to our understanding of the potential physiologic effects of Stat1-related disruptions in research mouse colonies that may be endemically infected with MNV.

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