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At least 793 records · Page 44Linked to original sources
PubMed1975

A rare case of megaloblastic anaemia caused by disturbances in the plasma cobalamin binding proteins in a patient with hepatocellular carcinoma.

A patient with hepatocellular carcinoma, megaloblastic anaemia and increased concentration of serum cobalamin is described. Plasma TC I was increased to 10,000 times the normal concentration, thus explaining the increased concentration of serum cobalamin and a false Schilling test. The increase in plasma TC I in concurrence with undetectable amounts of plasma TC II was a likely explanation for the anaemia. The electron microscopic picture of the hepatocellular carcinoma was in accordance with TC I being produced by the tumour cells.

Anemia, Macrocytic↗
PubMed1977

Vitamin B12 metabolism in myelomatosis.

In 38 patients with myelomatosis the serum cobalamin varied from 34 pmol/1 to 404 pmol/1, median 181.5 pmol/1, which is significantly lower than the levels in 22 control persons with range 173-535 pmol/1, median 265 pmol/1. In spite of low serum cobalamin no symptoms of vitamin B12 deficiency could be demonstrated in any of the patients, except for the one patient who had a serum cobalamin of 34 pmol/1. Mean values for Hb, MCV, PCV, serum lactate-dehydrogenase, adjested red cell folate and nucleated neutrophil count were similar in a group of patients with a serum cobalamin below 160 pmol/1 and a group of patients with higher serum cobalamin values. The decrease in serum cobalamin is due in part to a reduction in the major cobalamin binder (TC-I) in serum. Measuring serum cobalamin in relationship to gastric acis secretion, we found a significantly higher frequency of hypo- and achlorhydria in patients with serum cobalamin below 160 pmol/1 although the intestinal absorption of vitamin B12 was normal by a Schilling test. Although our finding of low saturation of TC-I in serum seems to demonstrate decreased vitamin B12 content in the body in myelomatosis, the lack of evidence for a functional vitamin B12 deficiency speaks against giving a supplement to patients with myelomatosis.

Aged↗
PubMed1983

Eosinophilic granulocytes as a possible source of vitamin B12-binding protein.

Leucocyte B12 and B12-binding capacity were measured by Simultrac radioassay in eosinophilic granulocytes, neutrophilic granulocytes and leucocytes obtained from patients with chronic granulocytic and lymphocytic leukaemia. It is shown that (a) eosinophils are a possible source of B12-binding protein similar to neutrophils and (b) granulocytes in myeloproliferative disorders and normal neutrophils have similar B12 and B12-binding capacity indicating that increased B12 and B12-binding capacity in myeloproliferative disorders arise from an increase in myeloid cell turnover.

Eosinophilia↗
PubMed1993

Mobilization of granules in neutrophils from patients with myeloproliferative disorders.

Neutrophil granule subsets and dynamics were studied in 4 patients with polycythemia vera/myelofibrosis and 2 patients with chronic myelogenous leukemia. Alkaline phosphatase, a marker for the membrane of secretory vesicles (the most readily mobilizable pool of intracellular membranes in neutrophils) was highly elevated in the PV/MF patients and significantly reduced in the CML patients. In spite of this, the amount of secretory vesicles was normal as judged by the content of albumin, and of the membrane protein cytochrome b-245 and CD11b, both partially localized in secretory vesicles. Gelatinase granules were present in all patients. The azurophil granules were lighter than normal in both CML patients. SDS-PAGE protein profiles indicated absence of defensins from azurophil granules from 1 CML patient. In addition, a 41-42 kD doublet protein band was absent from 2 PV and 1 CML patient, and reduced in the other CML patient. No difference in mobilization of granules was observed between patient neutrophils and control neutrophils. Also, stimulation with 10(-8) mol/l N-formyl-methionyl-leucyl-phenylalanine induced normal increases in intracellular Ca2+ in patient neutrophils. These results indicate that stimulus-response coupling leading to granule exocytosis is intact in neutrophils from patients with myeloproliferative disorders.

Aged↗
PubMed1980

The effect of digestive enzymes on the binding and bacteriostatic properties of lactoferrin and vitamin B12 binder in human milk.

Human milk contains unsaturated lactoferrin and vitamin B12 binding protein. It has been suggested that these proteins may exert antibacterial effects in the intestine of the breast fed infant, but the effect of the intestinal environment on the antibacterial effect of these proteins has not been described. In this study human milk was treated with pepsin and trypsin and the influence of digestion on iron and vitamin B12 binding capacity, bacterial uptake of iron and vitamin B12 from milk and bacteriostatic effect was studied. Pepsin digestion had no effect on vitamin B12 binding capacity, or the ability of bacteria to take up vitamin B12, or the growth inhibitory effect on a vitamin B12 dependent strain. In contrast, trypsin digestion did not affect iron binding or bacteriostatic effects attributable to lactoferrin. The. findings support an in vivo bacteriostatic role for lactoferrin in the breast fed neonate's intestine but do not support a similar role for the vitamin B12 binding protein.

Bacterial Proteins↗
PubMed1994

Secretion of acid, gastrin, and cobalamin-binding proteins by the fetal pig stomach: developmental regulation by cortisol.

The role of cortisol in the development of gastric function was investigated in the fetal pig. Pregnant sows (term = 114 +/- 2 days, n = 10) were anaesthetized (pentobarbitone) and osmotic minipumps containing either saline or cortisol inserted subcutaneously into fetuses at 82-84 (n = 11) or 91-96 (n = 14) days gestation. Six days later the infused pigs were removed by Caesarean section and the stomach and its contents collected for analysis. Samples were also obtained from unoperated (control) fetal pigs (n = 51) removed under anaesthesia at intervals from 70 days gestation until term. The concentrations of acid in gastric fluid, gastrin in plasma and antral tissue (bioactive as well as precursor forms), and cobalamin(CBL)-binding proteins in fundic tissue were low in control pigs until 100 days gestation. During the last 2 weeks before term, large increases occurred in gastric fluid acidity (from pH 6-7 to pH 3 at birth), plasma amidated gastrin (from 10 to 90 pM) and CBL-binding protein concentration (from 10 to 80 pmol (g fundus)-1). These changes occurred in parallel with a surge in plasma cortisol (from 20 to 200 ng ml-1). Immature fetuses infused with cortisol had significantly higher gastric acidity, plasma amidated gastrin, and concentration of CBL-binding proteins than the corresponding control fetuses (P < 0.05). Across age and treatment groups, significant correlations were found between log10 plasma cortisol values and the above parameters (r = 0.59-0.76, P < 0.01). The results suggest that endogenous cortisol secretion stimulates the secretion of gastric acid, gastrin and CBL-binding proteins in the prenatal period of the pig.

Animals↗
PubMed1995

Vaginal birth versus elective caesarean section: effects on gastric function in the neonate.

Plasma gastrin concentration increases in late gestation and reaches a peak at birth or shortly after birth in many species ('neonatal hypergastrinaemia'). We investigated the hypothesis that gastrin and gastric acid secretion in the neonate is influenced by the final rise in plasma cortisol associated with spontaneous (vaginal) birth. Caesarean-delivered (CD, n = 28) or vaginally delivered (VD, n = 24) premature or full-term piglets (97-115 days gestation) were killed immediately after birth (using pentobarbitone). Compared with newborn CD pigs, the newborn VD pigs had significantly higher (P < 0.05) concentrations of cortisol (669 +/- 60 versus 223 +/- 2 nM) and gastrin (57 +/- 4 versus 33 +/- 1 pM) in plasma, and significantly lower gastric fluid pH (3.3 +/- 0.2 versus 4.7 +/- 0.3), amidated (bioactive) gastrin in the antrum (550 +/- 77 versus 1220 +/- 29 pmol g-1) and glycine-extended (precursor) gastrin in the antrum (81 +/- 10 versus 143 +/- 5 pmol g-1). There were significant linear correlations between log plasma cortisol values and plasma gastrin (r = 0.40, P < 0.05) or gastric fluid pH (r = -0.51, P < 0.05) in newborn pigs. The effects of cortisol in the immediate postnatal period were investigated in forty-one CD pigs born at 111-112 days gestation and treated with saline, metyrapone (an inhibitor of cortisol synthesis) or adrenocorticotrophic hormone (ACTH) from 0 to 7 days after birth. At 7 days, plasma gastrin in ACTH-treated pigs (elevated plasma cortisol) was significantly lower than in saline-treated pigs, but not different from that in metyrapone-treated pigs (low plasma cortisol). No treatment effects were observed postnatally for antral gastrin and fundic cobalamin-binding protein concentrations. These results suggest that in the intrapartum period the high circulating cortisol levels stimulate the normal rise in gastrin and acid secretion associated with spontaneous vaginal delivery in the piglet, whereas postnatally, cortisol is unlikely to play an important role in the subsequent development of gastrin and acid secretion.

Adrenal Glands↗
PubMed1985

Phagocytosis of brushite crystals by pig neutrophils.

Neutrophils from pig blood were disrupted by homogenisation or sonication and placed on an analytical sucrose gradient. Pig neutrophil azurophil granules were less dense than the specific granules, unlike those from neutrophils of most other mammalian species. Brushite crystals, which stimulate the respiratory burst in pig neutrophils, were found by electron microscopy to be phagocytosed. Membrane-limited vesicles containing crystals were obtained from a dense region of the sucrose gradient loaded with a homogenate of crystal treated cells. Intake of crystals involved preferential mobilisation of cytochrome b from the plasma membrane and the fusion of both specific and azurophil granules with the primary phagosome. Plasma membrane and granule markers appear in a crystal-containing region of the sucrose gradient when cells are treated with crystals. They are present in much lower concentration at this location in gradients from cells untreated with a crystal stimulus.

Animals↗
PubMed1978

Vitamin B12 binding protein as a tumour marker for hepatocellular carcinoma.

Grossly raised levels of tumour related vitamin B12 binding protein, reflected by rises in serum vitamin B12 and unsaturated vitamin B12 binding capacity (UBBC), were found in three of 44 patients with hepatocellular carcinoma. All three were HBsAg negative and had normal serum alpha fetoprotein levels. The patients did not have underlying cirrhosis and the tumours contained characteristic intracellular inclusions. In the first patient the UBBC level fell during a partial remission induced by adriamycin therapy and in the second patient UBBC levels rose with progression of her disease. In the third patient serum B12 binding protein levels fell after tumour resection. Assay and subsequent monitoring of serum vitamin B12 and UBCC may prove valuable in the assessment and follow-up of some patients with hepatocellular carcinoma whose alpha fetoprotein levels are normal.

Adolescent↗
PubMed1987

Immunohistochemical localisation of vitamin B12 R-binder in the human digestive tract.

The distribution of vitamin B12 R-binder in the human digestive tract was studied using an indirect immunoperoxidase technique. Positive staining for R-binder was found in the mucous cells and ductal epithelial cells of the salivary glands and the oesophageal glands. In normal gastric mucosa, no positive staining for R-binder was found, but in the area with intestinal metaplasia, the columnar epithelial cells and goblet cells showed positive staining. Epithelial cells of the gallbladder, intrahepatic bile ducts and pancreatic ducts were also positive for R-binder. In the small intestine and colon, R-binder was found in the columnar epithelial cells and goblet cells. The measurement of unsaturated vitamin B12 binding capacity and cobalamin content in the extracts from intestinal mucosa also indicated the presence of R-binder in the intestinal mucosa.

Adult↗