Characterization of human IgG1 monoclonal antibody against gangliosides expressed on tumor cells

In this study, our intention was to describe the decision making of nurses practicing in intensive care, and the differences of nurses' decision making in Canada, Finland, Northern Ireland, Switzerland, and the United States. The instrument used in the study was a 56-item Likert-type questionnaire that has been used in previous studies and has proved to be a reliable tool. The target group comprised a nonrandom sample of nurses (N = 314) from five countries. The samples are not representative; therefore, the results in these cases cannot be generalized. The results showed that the decision making of nurses practicing in intensive care was broadly based, and that there were some country differences in data collection, problem definition, and planning. In contrast, decision making related to the implementation and evaluation of nursing is quite similar in the different countries. Canada and the United States on the one hand, and Finland, Northern Ireland, and Switzerland on the other, showed more similarities with each other in data collection, problem definition, and nursing planning related to decision making. Neither experience nor nurse's knowledge structure was associated with different decision-making approaches.     

Soluble tumor necrosis factor receptors are present in human vitreous and shed by retinal pigment epithelial cells

Tumor necrosis factor-alpha (TNF) has been implicated in the pathogenesis of several retinal diseases. Soluble forms of the TNF receptors, p55 (55 kDa) and p75 (75 kDa), have recently been identified in biological fluids and may regulate TNF activity. The potential biological significance of these receptors for the human retina was examined by determining their presence in human vitreous and their release from eye cup explants in which the retina has been removed leaving an intact retinal pigment epithelium (HRPE). Normal human vitreous and conditioned medium from eye-cup HRPE explants demonstrated the presence of soluble p55 and p75. Soluble p55 was significantly more abundant than p75 in all vitreous samples (P < 0.03). Conditioned medium from eye-cup HRPE explants contained significantly more soluble p55 than p75 (P < 0.00002). Enzyme-linked immunosorbent assay showed the presence of soluble p55, and not p75, in conditioned medium from primary cultured HRPE cells. Activation of the protein kinase C pathway in these cells with the phorbol ester PMA significantly increased the release of soluble p55 (P < or = 0.001); whereas, pharmacological inhibition of protein kinase C with calphostin-C significantly decreased the shedding of p55 (P < or = 0.001). The results indicate that primary cultured HRPE cells shed p55 and regulate this shedding in part through the protein kinase C pathway. The presence of soluble TNF receptors within normal human vitreous and within conditioned medium from the eye-cup HRPE explant model suggests that these soluble receptors may have a biological function in the eye.     

Individual prostate-specific antigen (PSA) forms as prostate tumor markers

Prostate-specific antigen (PSA) is a kallikrein-like serine protease mainly expressed in the human prostate. It is responsible for the proteolysis of the gel-forming proteins in human semen. Two major extracellular protease inhibitors, alpha-1-antichymotrypsin (ACT) and alpha-2-macroglobulin (AMG) may inactivate PSA escaping from the prostate. The predominant immunodetected form of PSA in serum is complexed to ACT but PSA exists also in a free non-complexed form despite the large excess of inhibitors. The concentrations of PSA in serum are normally less than 4 micrograms/l. but elevated concentrations are found in a majority of patients with prostate cancer (CAP) and the analysis of PSA in serum has become invaluable in the detection and monitoring of patients with CAP. However, it is not an ideal tumor marker in the sense that there are CAP patients with normal PSA concentrations in serum and patients with benign hyperplasia of the prostate (BPH) with elevated PSA concentrations. Analysis of the various PSA forms in serum attracts much interest as there is a higher proportion of PSA in complex with ACT in patients with CAP than in those with BPH. Optimal combinations of monoclonal antibodies have been used to design sensitive noncross-reacting immunoassays for the detection of free PSA, PSA-ACT complexes and the detection of both free PSA and PSA complexes in an equimolar fashion (i.e. total PSA). Several studies have demonstrated that the analysis of the proportions of the free-to-total PSA in serum may increase the diagnostic specificity by 15-20% without significant loss in the sensitivity for detection of CAP.     

Inhibition of hemopoiesis in vitro by neuroblastoma-derived gangliosides

Hemopoiesis is disturbed in bone marrow-involving cancers like leukemia and neuroblastoma. Shedding of gangliosides by tumor cells may contribute to this tumor-induced bone marrow suppression. We studied in vitro the inhibitory effects of murine neuroblastoma cells (Neuro-2a and C1300) and their gangliosides on hemopoiesis using normal murine hemopoietic progenitor colony-forming assays. Transwell cultured neuroblastoma cells showed a dose-dependent inhibition on hemopoiesis, indicating that a soluble factor was responsible for this effect. Furthermore, the supernatant of Neuro-2a cultured cells inhibited hemopoietic proliferation and differentiation. To determine whether the inhibitory effect was indeed due to shed gangliosides and not, for instance, caused by cytokines, the effect of DL-threo-1 -phenyl-2-decanoylamino-3-morpholino-1-propanol (DL-PDMP) on Neuro-2a cells was studied. DL-PDMP is a potent inhibitor of glucosylceramide synthase, resulting in inhibition of the synthesis and shedding of gangliosides. The initially observed inhibitory effect of supernatant of Neuro-2a cells was abrogated by culturing these cells for 3 days in the presence of 10 microM DL-PDMP. Moreover, gangliosides isolated from Neuro-2a cell membranes inhibited hemopoietic growth. To determine whether the described phenomena in vitro are a reflection of bone marrow suppression occurring in vivo, gangliosides isolated from plasma of neuroblastoma patients were tested for their effects on human hemopoietic progenitor colony-forming assays. These human neuroblastoma-derived gangliosides inhibited normal erythropoiesis (colony-forming unit-erythroid/burst-forming unit-erythroid) and myelopoiesis (colony-forming unit-granulocyte/macrophage) to a higher extent compared with gangliosides isolated from control plasma. Altogether these results suggest that gangliosides shed by neuroblastoma cells inhibit hemopoiesis and may contribute to the observed bone marrow depression in neuroblastoma patients.     

Autotransfused shed mediastinal blood has normal erythrocyte survival

The anticoagulant action of Anisakis simplex larvae on human blood in vitro was examined. Anticoagulant activity was assessed by routine screening tests that evaluate the overall competency of the coagulant mechanism. A slight prolongation of the prothrombin time (PT) was observed with the larval crude extracts. Prolongation of the PT was seen at a concentration of excretory/secretory (ES) products greater than 62.5 micrograms/ml. No prolongation of the activated partial thromboplastin time (PTT) was observed using crude extracts. There was a prolongation of the PTT with ES products at concentrations greater than 62.5 micrograms/ml. ES products of the larvae were able to prolong coagulation times indicating that they contain an inhibitory or anticoagulant property. Preparation of crude extracts of A. simplex showed only minimal anticoagulant activity. The results obtained by measurements of the PT and the PTT suggest a probable alteration of one of the coagulation proteins namely factors Xa, IIa or Va. These findings suggest that the anticoagulant activity demonstrated in the ES products may play an important role during invasion of the gastric or intestinal mucosa by larvae and could have biological significance in infected patients.     

Autotransfusion of shed mediastinal blood after open heart operation

This prospective study was designed to determine whether the autotransfusion of shed mediastinal blood (ATS) after open heart surgery is safe and effective. Forty-two patients undergoing cardiac operation were randomized to receive either nonwashed shed mediastinal blood (group 1; n = 22) or banked blood (group 2: n = 20). No difference in mean age (group 1: 49 +/- 11 years; group 2: 45 +/- 12 years), coronary artery bypass grafting (group 1: n = 5, 23%; group 2: n = 6, 30%), valve replacement (group 1: n = 17, 77%, group 2: n = 14, 70%), and mean preoperative hemoglobin level (group 1: 13.7 +/- 2.3, group 2: 14.4 +/- 1.6) was noted between non-ATS and ATS groups (p = not significant). The mean hemoglobin levels after operation were similar in the two groups (group 1: 11.89 +/- 1.52; group 2: 12.03 +/- 1.34). No difference in the mean blood loss 4, 6 and 24 hours after operation (group 1: 33 +/- 190, 420 +/- 340 and 550 +/- 300; group 2: 340 +/- 230, 420 +/- 280 and 670 +/- 380) was observed between the two groups. The mean volume autotransfused in group I was 380 +/- 230 ml (200 approximately 1300 ml). In group I, the patients required bank blood 1080 +/- 720, compared with 1780 +/- 1045 in group II. The bank blood requirement in group I reducted by 40%. These data demonstrate that ATS after open heart surgery is safe and effective.     

An improved assay of gangliosides separated by thin-layer chromatography

There were no differences in the recoveries of ganglioside sialic acid from silica gel G thin-layer chromatograms when they were sprayed with resorcinol reagent varying in normality between 3 and 10. However, both the temperature at and the time for which the plates were heated after spraying did affect the recoveries, which can reach 100% when the plates are heated for 6 min at 135degreesC.     

Target antigens in autoimmune diabetes: pancreatic gangliosides

Type 1 diabetes mellitus is a disease caused by the autoimmune destruction of insulin-producing pancreatic beta-cells that takes place in genetically prodisposed individuals. Autoantibodies and autoreactive T lymphocytes reacting with islet target molecules or protein of glycolipid nature have been shown in the circulation of individuals and of animal models of type 1 diabetes (NOD mouse and BB rat) before and at the onset of the disease. As far as autoantigens of glycolipid nature is concerned, gangliosides such as GT3, GD3 and especially GM-1, have been shown to be target of autoantibodies associated to autoimmune diabetes. Of particular interest is the islet-specific monosialo-ganglioside GM2-1, which is target of an autoimmune response highly associated to future progression to diabetes development in first degree relatives of type 1 diabetic individuals. This molecule is recognized by IgG autoantibodies which have been detected before the appearance if clinical diabetes both in man and in the NOD mouse, representing a novel marker of beta-cell autoimmunity.     

Observation of an increase in "aggressive tumor forms" in increasing incidence of breast carcinoma

Between 1986 and 1990 23% more patients with carcinomas of the breast were treated in the Gynaecological Hospital of the Municipal Hospital (St?dt. Krankenanstalten) of Krefeld than during the comparative period between 1976 and 1980. Simultaneously, an increase of carcinomas metastasising the further course of the disease were observed. When analysing the possible reasons it can be noticed that in the first group (1986 to 1990) compared to the second group (1976 to 1980) multifocal and lobular carcinomas were observed more frequently with regard to their statistical significance. The same applies to the metastatic involvement of axillary and infraclavicular lymphodes. It was noticed that in the first group, lymphangiosis and hemangiosis carcinomatosa were seen more frequently than in the second group. The collected data suggest that in case of an increase in carcinomas of the breast, a larger number of tumours with prognostically unfavourable tumour criteria is seen.     

Audit of post-operative auto-transfusion of shed blood in hip arthroplasty

Auto-transfusion of shed blood for joint arthroplasty has several theoretical advantages: availability, compatibility, avoidance of transmission of infection and cost. The clinical records of 92 primary hip arthroplasties were reviewed to investigate the effect of auto-transfusion on the use of the National Blood Transfusion Service both in terms of blood ordered and subsequently used. Overall, post-operative auto-transfusion had no significant effect on blood ordering or usage and was very expensive. The majority of patients were over transfused.     

VCN-releasable sialic acid and gangliosides in human neuroblastomas

The ganglioside pattern and VCN-releasable sialic acid residues of six human neuroblastomas were studied. There was no correlation between VCN-releasable sialic acid and prognosis. The ganglioside patterns were more complex in those cases with an expected good prognosis as reflected by the presence of trisialoganglioside. The complexity of the ganglioside pattern did not always correlate with the histologic grade of the tumor. These results suggest the ganglioside pattern may serve as a chemical marker for predicting the prognosis in patients with neuroblastomas.     

Assessment of lead exposure of children from K-XRF measurements of shed teeth

Lead is accumulated and immobilized for long periods of time in teeth. Thus the Pb concentration of a tooth can be used as an indicator of the cumulative Pb intake of a child. Shed and extracted teeth were collected from children in Beijing, China and some industrial regions in the Middle Urals in Russia. The Pb levels in the teeth were measured in Philadelphia, PA using an X-ray fluorescence (XRF) technique. Since Pb deposits in the tooth during the entire period that it is in the child, the measured tooth Pb level was divided by the age of the child when the tooth was shed and expressed in terms of (microgram/g-yr). 10% (n = 100) of the teeth from Beijing, China had Pb levels exceeding 5.5 and 3% above 9 micrograms/g-yr. For comparison, in the 1970s when urban environmental Pb levels were elevated, the tooth Pb levels in Philadelphia children were similar, i.e. 10% (n = 298) of the teeth had Pb levels exceeding 7.5 and 6% were above 9 micrograms/g-yr. Children in a more rural setting, Bennington, VT, had no detectable tooth Pb (n = 200). The Pb levels in the teeth from the Urals were much higher; 50% (n = 134) of the teeth had Pb levels exceeding 7.5 and 10% exceeding 17.8 micrograms/g-yr. The tooth Pb levels observed in the teeth from Beijing, and more so from the Urals, indicate that these children are residing in Pb polluted environments. Further studies are required to determine the extent of the Pb pollution and to explore the possibility that there are associated Pb-related health deficits.     

Sulfated glucuronyl glycolipids and gangliosides in the optic nerve of humans

Pathologically delayed visual evoked potentials may be present in patients with neuropathy associated with IgM M-proteinemia, which is directed against myelin-associated glycoprotein and sulfated glucuronyl glycolipids (SGGLs), but there are no reports of these antigens in the optic nerve. We recently examined human optic nerve and occipital lobe tissues for the occurrence of SGGLs using the technique of immunostaining on thin-layer chromatographic plates and found them in the optic nerve, but not the occipital lobe. SGGLs in the optic nerve may represent target antigens for CNS involvement by the M-protein in patients with neuropathy. We also studied the ganglioside composition of the optic nerve and found it different from that of the brain. Human optic nerve is characterized by an abundance of the b-series gangliosides, including GD1b, GT1b, and GQ1b. GD1a, which is usually a major component of brain gangliosides, is only a minor species of the optic nerve ganglioside fraction.     

Recent discoveries of Dryopithecus shed new light on evolution of great apes

The origin and early evolution of the great ape/human clade (Hominidae) is currently a subject of debate. The controversy is fuelled by the fragmentary nature of the fossils which renders it difficult to determine clearly derived features that permit the recognition of fossil members of this clade. We report here the recent discovery of a facial skeleton and a temporal fragment with the petrosal bone of Dryopithecus laietanus, which provides a way out of an impasse. The lack of the fossa subarcuata is a great ape and human clade synapomorphy, and proves unequivocally that Dryopithecus belongs to this clade. The zygomatic possesses derived characters which reveal that Dryopithecus is related to the Ponginae and not to the African apes/humans, as recently suggested. The remaining morphological features are plesiomorphic and thus provide a good model of a common ancestor of all Hominidae.     

Chemical, metabolic and immunological characterization of gangliosides of human glioma cells

The patterns of ganglioside profiles were studied in 10 human glioma and one melanoma cell lines. Ganglio-series gangliosides, GM3 (NeuAc alpha2-3Gal beta1-4Glc beta1-Cer) and GM2 (GalNAc beta 1-4 (NeuAc alpha2-3)Gal beta1-4Glc beta 1-1Cer), and a neolacto-series ganglioside, sialylparagloboside (SPG) (NeuAc alpha 2-3Gal beta1-4GlcNAc beta1-3Gal beta1-4Glc beta1-1Cer), were the predominant constituents. The activities of the two key enzymes, GM3 synthetase and lactotriaosyl ceramide (Lc3Cer) synthetase, alone did not account for the ganglioside profile. Metabolic labeling with the use of [3H]glucosamine-HCl showed more pronounced difference in the synthetic rate of each ganglioside type, in which GM2 was the most strongly labeled in 7 out of the 10 glioma cell lines. On quantifying the chemical content of GM3 and GM2, the GM3/GM2 molar ratio of above 2.0 was arbitrarily classified into GM3 dominant type (KG-1C and Mewo); the ratio below 0.5 was designated as GM2 dominant type (H4, U138MG, U373MG, T98G and A172); and the ratio between 0.5 and 2.0 was regarded as GM3 and GM2-co-dominant type (U87MG, Hs683, SW1088 and U118MG). Subsequently, the capabilities of the antibody binding to these gangliosides were examined in native forms in the cell membrane and in chemically-isolated forms. The intensity of reaction against chemically isolated GM3 and GM2 gangliosides was dependent on the quantity, and GM2 was more reactive than GM3; however, the reactivities on the cell surface did not correlate with the chemical content indicating other factors to influence their immunoreactivities.