Calculation of secretory antibodies and immunoglobulins

There is increasing evidence for the secretion of IgG and IgE, as well as IgA, antibodies by the nasal mucosa. Because the former immunoglobulins lack an identifiable secretory piece, estimates of their secretion have been based on their ratio to albumin or to total immunoglobulin of the same type in the nasal secretion as compared with serum. It is shown, however, that use of the ratio to albumin will result in large errors if the amount of antibody secreted by the nose is relatively small, and ratios based on total secretory Ig will, at least hypothetically, lead to error if antibodies with multiple specificities are being secreted. It is suggested that a more valid quantitation will be obtained from the expression

$INS=\frac{{Ab}_N}{{Alb}_N}-\frac{{Al}_S}{{Alb}_S}$

where INS is an index of nasal secretion, Ab = antibody, Alb = albumin, N = nasal secretion, and S = serum.     

Calcium transport and the secretory ameloblast

The distribution of calcium in the enamel organ of the rat incisor was investigated using potassium pyroantimonate for ultrastructural localization of calcium. Substantial amounts of precipitate occurred in the intercellular compartment of the enamel organ and modest deposits were observed in specific organelles of the secretory ameloblast. Mitochondria, nuclei, granular endoplasmic reticulum, Golgi vesicles and secretory granules consistently contained small deposits of pyroantimonate. Complexing of calcium by the pyroantimonate was confirmed by EGTA decalcification and scanning electron microscope energy dispersive X-ray analysis. The observed distribution is discussed in light of potential for an intercellular pathway of calcium transport as well as controlled movement of the ion along the synthetic and secretory route followed by organic components of enamel.     

Serum immunoglobulins and secretory IgA deficiency in tonsillectomized children

We studied serum immunoglobulin patterns in 65 children aged 2 to 10 years before and 1 to 4 months after tonsillectomy and adenoidectomy, and secretory IgA (sIgA) levels in 46 children aged 3 to 10 years before and 1 month after the same operation. Serum immunoglobulin and sIgA values were normal prior to surgery, and significantly lower afterwards. The data emphasize the importance of palatine tonsils not only in the synthesis of monomeric immunoglobulins but also in the synthesis of dimeric immunoglobulins in secretions. Although more long-term, follow-up studies supporting our results are needed, we suggest that a post-adenotonsillectomy drop in immunoglobulin and sIgA levels may predispose children to a constellation of disorders. We recommend, therefore, that serum immunoglobulins and sIgA levels be determined in all children before and after surgery.     

Nasopharyngeal secretory immunoglobulins in children with recurrent acute otitis media and secretory otitis media

Secretory IgA (SIgA) and secretory IgM (SIgM), total IgA and total IgM were measured in plasma and nasopharyngeal secretions (NPS) from young children with different degrees of otitis proneness. Significantly higher levels of plasma IgM and lower levels of NPS-SIgM were found in children with recurrent episodes of acute otitis media (rAOM) compared with children suffering from secretory otitis media (SOM) and healthy controls. Both plasma IgA and NPS-SIgA were evenly distributed in the three groups of children investigated, and in most children the levels of NPS-SIgA exceeded plasma IgA levels. Plasma SIgA was significantly increased in children with rAOM and SOM, probably resulting from frequent occurrence of inflammatory events at the nasopharyngeal level. No correlation could be demonstrated between NPS-SIgA and plasma IgA, or between NPS-SIgM and plasma IgM. Also, for both NPS-SIgA and NPS-SIgM, there was no correlation with age. A negative correlation was observed between the transudation index of albumin to the nasopharynx and the ratio of NPS-SIgA to total NPS-IgA. A ratio of 1 (100%) corresponded to a transudation index of 8%. The ratios of NPS-SIgA to total NPS-IgA varied considerably and a range of 39%-88% could only to some extent be explained by transudation of plasma IgA to NPS. The results of the present study show that the children with rAOM and SOM are well furnished with locally produced SIgA antibodies at the nasopharyngeal level. In children with SOM, the nasopharyngeal hypofunction in the case of low NPS-SIgM seems to be less pronounced compared with that of otitis-prone children.     

Calcium transport and the secretory ameloblast.

The distribution of calcium in the enamel organ of the rat incisor was investigated using potassium pyroantimonate for ultrastructural localization of calcium. Substantial amounts of precipitate occurred in the intercellular compartment of the enamel organ and modest deposits were observed in specific organelles of the secretory ameloblast. Mitochondria, nuclei granular endoplasmic reticulum, Golgi vesicles and secretory granules consistently contained small deposits of pyroantimonate. Complexing of calcium by the pyroantimonate was confirmed by EGTA decalcification and scanning electron microscope energy dispersive X-ray analysis. The observed distribution is discussed in light of potential for an intercellular pathway of calcium transport as well as controlled movement of the ion along the synthetic and secretory route followed by organic components of enamel.     

Investigation of secretory immunoglobulins in saliva from germfree mice

We investigated the effect of oral immunization on the serum and salivary immunoglobulin levels in axenic and conventional NIH mice. Specific antibacterial and antifungal antibodies were measured by passive hemagglutination, and differences in the immunoglobulin classes were measured by radial immunodiffusion. After an oral immunization regimen with either intact Escherichia coli or Candida albicans, a significant increase in specific antibody above the base-line reciprocal titer of 32 was observed in conventional mouse saliva. Saliva from axenic mice immunized with the formalized microorganisms yielded reciprocal antibody titers of 256, as compared with an absence of specific antibodies in control animals. Assay of the sera of both groups of immunized mice revealed no increase in antibody levels specific for E. coli lipopolysaccharide or Candidin.     

The use of cholera toxin for obtaining rabbit secretory immunoglobulins

The work described here involved the use of cholera toxin to stimulate segments of the rabbit small intestine in vivo to obtain fluids for immunological study. These fluids were found to contain considerable 11 S IgA and by utilizing the entire small intestine it should be possible to obtain about 300 mg of this protein from a single rabbit.     

Human secretory immunoglobulins: VI. Association of free secretory piece with serum IgA in vitro

In vitro complexing of native free secretory piece (SP) was relatively specific for serum IgA, but only a minor proportion of the molecules combined. Two types of aggregate with the molecular size of polymer IgA were formed. One was indistinguishable from native secretory IgA; it contained disulphide-linked SP and exhibited a closely packed quaternary structure with inaccessible I determinant. This determinant was exposed in the other type which apparently represented relatively loose complexes stabilized solely by noncovalent forces.     

An improved method for recovery of secretory immunoglobulins and lymphocytes from the nasal mucosa

The difficulty of obtaining adequate specimens for assay has severely restricted in vivo investigations of local immune responses in humans. Washing the posterior nasopharynx for an extended period using chilled saline to stimulate serous secretions has improved yields of both secretory immunoglobulins and functionally competent immunocytes. The proportions of T- and B-cells found in such washings appear to differ from those found in blood.     

Human secretory immunoglobulins. II. Salivary secretions from individuals with selectively excessive or defective synthesis of serum immunoglobulins

Increased amounts of IgG were transmitted into the salivary secretions of patients with elevated serum levels of this immunoglobulin. Both its glandular and extra-glandular transfer apparently depended upon passive diffusion or epithelial `leakage'.

High serum levels of IgM (in macroglobulinaemia), and especially local synthesis of this immunoglobulin (in IgA deficiency), enhanced its transfer into the saliva. The transmission through secretory epithelium (glandular transfer) seemed to be an active or selective process, probably dependent upon specific `transfer sites' in the heavy polypetide chains of IgM.

The transmitted immunoglobulin (secretory IgM) was physicochemically and immunochemically similar to its 19S counterpart in serum. In IgA-deficient secretions no significant association between immunoglobulin components and secretory piece (SP) could be detected; the latter was physicochemically and immunochemically characterized as free SP.

     

Biochemical mechanisms of lipid-A-mediated enhancement of platelet secretory responses to aggregated immunoglobulins.

The mechanism by which endotoxins enhance the secretory response of washed preparations of human platelets to aggregated immunoglobulins (Agg-HGG) has been examined. Preparations of endotoxins from several rough mutants of bacteria enhance, by approximately 50-fold, the release of serotonin initiated by Agg-HGG. Endotoxins from smooth strains do not manifest this enhancement, and all endotoxin preparations are completely inactive in the absence of Agg-HGG. Preincubation and wash experiments have demonstrated that the critical initial interaction is the formation of complexes between the endotoxin and the Agg-HGG stimulus and is not dependent on an initial endotoxin-platelet interaction. Pretreatment of platelets with substimulatory concentrations of Agg-HGG, followed by the addition of endotoxin, causes a temporal decay in the degree of endotoxin-induced enhancement, which is inversely related to the concentration of Agg-HGG. This stimulus-specific desensitization suggests that the endotoxin-Agg-HGG complexes initiate release by a pathway similar to that initiated by Agg-HGG alone. We postulate that the endotoxin either enhances or stabilizes a localized platelet membrane perturbation or deformation, initiated by the Agg-HGG stimulus.     

外源性LIF和IL-1对围着床期小鼠子宫内膜整合素β3亚基表达的调节

目的研究外源性LIF及IL-1对围着床期子宫内膜整合素β     

Specific complex formation by human immunoglobulins and their corresponding antibodies

Specific complex formation by human immunoglobulins of classes M, G, and A with antibodies against class G immunoglobulins was studied by a thermistographic method. Depending on the type of interacting immunoglobulins, the rate and intensity of the process were shown to differ and to be maximal for IgM. Depending on the character of the curves obtained the class of immunoglobulins being synthesized at that given moment could be determined. Disturbance of the internal structure of the macromolecules of the immunoglobulins, as a result of heating, for example, leads to changes in the mechanism of complex formation; the important question in this event is which of the interacting components undergoes denaturation.Department of Immunology and Department of Experimental and Theoretical Physics. Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 89, No. 2, pp. 194–196, February, 1980.     

Regulation of organic cation transport

Transport of organic cations (OC) is important for the recycling of endogenous OC and also a necessary step for detoxification of exogenous OC in the body. Even though the identification and characterisation of numerous OC transporters in recent years has allowed the elucidation of molecular mechanisms underlying OC transport, elucidation of the regulation of this transport is just beginning. This review summarises the general properties of OC transport and then analyses the literature on the regulation of these processes. Studies on short- and long-term regulation of OC transport are considered separately. Important aspects of short-term regulation have been clarified and the regulatory pathways of several OC transporters have been characterised. Short-term regulation appears to be transporter subtype-, tissue- and species-dependent and to involve transporter phosphorylation. Transporter phosphorylation may alter the affinity for substrates or/and expression on the plasma membrane. Even though several studies have shown long-term regulation of OC transport, the pathophysiological meaning of these changes are not well understood. In this case, regulation seems to be subtype-, tissue- and gender-specific. Further research is necessary to clarify this important issue of regulation of OC transport.