Biomedical subjects

A Bernard

Publications and source records attributed to A Bernard.

At least 235 records · Page 13Linked to original sources

PubMed1995

Selective elution and purification of living Trichomonas vaginalis using gravitational field-flow fractionation.

Gravitational field-flow fractionation is one of the simplest separation methods for biological materials. Its potential in parasitology is demonstrated for Trichomonas vaginalis, a parasite responsible for one of the most widespread sexually transmitted diseases. It was observed that this unicellular parasite can be purified in a culture medium with a recovery of 85% for the living trophozoites. The parasite retention characteristics were different when motile living and non-motile dead cells were eluted, motile cells being less retained than the non-motile cells.

Adult↗

PubMed1995

Comitogenic effects of very late activation antigens on CD3-stimulated human thymocytes. Involvement of various tyrosine kinase pathways.

Thymocytes display several integrins that are involved in cell-extracellular matrix interactions and differentiation processes. We have examined the role of very late activation Ag (VLA) on human thymocyte stimulation. VLA-4, VLA-5, and VLA-6 activated with either mAbs or their natural ligands (fibronectin, laminin, and vascular cell adhesion molecule-1) are able to transduce costimulatory signals in thymocytes activated via the CD3 pathway, i.e., enhancement of thymocyte proliferation, CD25 and CD69 expression, and IL-2 secretion. In contrast, activation of thymocytes with a mitogenic pair of CD2 mAb was not modified by VLA molecules. Cross-linking of both beta 1- and alpha 5-chains induced tyrosine phosphorylation of several proteins, whereas the cross-linking of the alpha 4- and alpha 6-chains did not. Moreover, a different pattern of tyrosine phosphorylation was observed when thymocytes were activated via either beta 1- or alpha 5-chains. These results suggest that VLA molecules activate tyrosine kinase pathways in thymocytes, and that different pathways would be implicated during thymocyte interactions with extracellular matrix or accessory cells, which are likely to play a role in thymocyte differentiation.

Antibodies, Monoclonal↗

PubMed1995

The E2 molecule (CD99) specifically triggers homotypic aggregation of CD4+ CD8+ thymocytes.

We have previously described E2 as a 32-kDa transmembrane glycoprotein displaying an isomorphism, as two epitopes (defined by mAbs O662 and L129) are widely distributed on T cells whereas two epitopes are restricted to T cell subsets (defined by mAbs D44 and 12E7). E2, the MIC-2 gene product, is involved in T cell adhesion because anti-E2 mAbs against pan T epitopes block spontaneous T cell rosettes. Pan T E2 mAbs are also able to induce exposure of the phosphatidylserine at the thymocyte surface but not at the surface of mature T lymphocytes, an event most likely linked to adhesion phenomena. We now show here that the anti-E2 mAbs (0662 and L129) that block rosettes and induce phosphatidylserine exposure at the thymocyte surface, and not those reacting with epitopes not involved in adhesion, also trigger aggregation of certain immature T cell lines and no other cell lines tested. Among the normal cells tested, anti-E2 mAbs exclusively induce homotypic aggregation of CD4+ CD8+ human thymocytes. This phenomenon is temperature, energy, and Mg++ dependent, and requires an intact cytoskeleton. These adhesion properties are rather characteristic of integrins. Nevertheless, mAb against beta 1, beta 2, and beta 3 integrin chains, as well as those against alpha-chains known to be present on thymocytes, are unable to block corticothymocyte aggregation. We conclude that E2 triggers on corticothymocytes and no other T cells a homotypic adhesion pathway most likely mediated by an uncharacterized integrin.

12E7 Antigen↗

PubMed1995

The glycosylphosphatidylinositol-anchored CD59 protein stimulates both T cell receptor zeta/ZAP-70-dependent and -independent signaling pathways in T cells.

The glycosylphosphatidylinositol (GPI)-anchored CD59 protein (human protectin) protects cells against complement-induced lysis, binds to CD2 and also transduces activation signals within T cells. We have further examined the biochemical signals transduced by CD59 and addressed its role in regard to the CD3-mediated signaling cascade. We show here that CD59 cross-linking induces a time-dependent activation of p56lck and of p70zap (ZAP-70) in CD3-positive Jurkat cells, leading to the stimulation of the T cell receptor zeta/ZAP-70 signaling cascade and interleukin-2 (IL-2) synthesis. Cross-linking of CD59 on peripheral T cells and thymocytes induces tyrosine phosphorylations identical to those seen in Jurkat cells and this is followed by lymphokine production and proliferation. In contrast, only activation of CD59-associated p56lck occurs in CD3-negative Jurkat cells, while IL-2 production is impaired, consistent with the lack of ZAP-70 tyrosine phosphorylation observed in these cells. CD59 triggers activation events even in the absence of CD3/T cell receptor expression in Jurkat cells. CD59 cross-linking synergizes with sub-optimal doses of phorbol ester for activation of the protein kinase C and of the p42mapk, as shown by in vitro phosphorylation of histone HIIIS and myelin basic protein, respectively, and leads to CD25 but not CD69 expression. In conclusion, at least two signaling pathways are triggered through CD59, the first one involving ZAP-70 activation and leading to IL-2 secretion and a second pathway observed in the absence of ZAP-70 activation leading to CD25 expression. These two pathways are likely to be involved in the modulation of T cell activation by CD59 protein.

Antigens, CD↗

PubMed1995

Cassette baculovirus vectors for the production of chimeric, humanized, or human antibodies in insect cells.

Plasmid cassette-transfer vectors pBHuC chi and pBHuC gamma l have been designed which enable the construction of recombinant baculoviruses directing the co-expression of complete immunoglobulin in insect cells. We describe the application of these vectors for the expression of a human/mouse chimeric monoclonal antibody of potential immunosuppressive clinical value derived from a mouse anti-human CD29 monoclonal antibody (Mu-K20). The chimeric K20 light and heavy chains produced in sf9 insect cells were correctly processed and assembled into a normal immunoglobulin which is secreted into the culture medium of infected cells. The chimeric mAb Ch-K20-sf9 reproduces in vitro the functional properties of the parental mouse K20, including affinity and inhibition of lymphocyte proliferation. These results demonstrate that the baculovirus/insect cell expression system is suitable for the expression of fully active monoclonal antibodies of therapeutic value. Our generic cassette approach makes this system a very flexible and convenient one for the rapid production of either chimeric, humanized or human mAb with heavy and light chains of any isotype.

Animals↗

PubMed1995

Molecular correlates between reactive and developmental plasticity in the rat hippocampus.

Area CA3 of the hippocampus is the most epileptogenic structure of the brain. Various studies have shown that kainate-induced experimental epilepsy in rats and human cases of epilepsy are associated with sprouting of the mossy fibers of the dentate granule neurons and selective loss of pyramidal neurons, notably in the CA3-CA4 areas of Ammon's horn. In experimental models of epilepsy, brief seizure activity initiates a cascade of molecular alterations that will contribute to changes in the expression of numerous genes, which can last several weeks. The products of some of these genes will contribute to the permanent state of enhanced synaptic efficiency, to the sprouting and formation of novel excitatory synapses, and possibly to neuronal cell loss. The expression of genes encoding transcription factors and numerous growth factors is rapidly altered following seizure episodes. Based on observations in vivo and in vitro in cultured hippocampal neurons, it is hypothesized that an interplay between transcription and growth factors, because of their pleiotropic effects on the regulation of effector genes, may be instrumental in coupling transient extracellular stimuli to irreversible cellular alterations.

Animals↗

PubMed1995

Monocyte-independent T cell activation by simultaneous binding of three CD2 monoclonal antibodies (D66 + T11.1 + GT2).

Mitogenic pairs of CD2 mAb typically transduce activation/proliferation signals within T cells. However, complementary signal(s) provided by accessory cells are required to induce T cell proliferation. We show here that a particular combination of three CD2 mAb, D66 + GT2 + T11.1, leads to the proliferation of highly purified human T lymphocytes, without other complementary signal(s). The CD2 triplets was able to induce CD4+ and, to a lesser extent, CD8+ cells to proliferate. Interestingly, the so-called "naive" T cells (CD45RA+) were strongly stimulated, but more immature cells, such as thymocytes, were not. The proliferative response induced by the CD2 triplet was entirely mediated by the IL-2 autocrine pathway, as shown by the complete inhibition with anti-IL2 Ab. T cells stimulated with the CD2 triplet were also able to secrete TNF alpha. We found no evidence for an unusual secretion of cytokines that might explain the lack of requirement of complementary signal(s). As high as it was, the proliferation induced by the CD2 mAb triplet could be further increased by the addition of IL-1, and this proliferative fraction could be inhibited by antibodies against TNF alpha. The CD2 mAb triplet increased [Ca2+]i, while mitogenic CD2 mAb pairs needed the presence of a cross-linking agent. Thus, our data show that T cells can be activated to fully proliferate by this particular CD2 pathway, in the absence of accessory signal(s).

Adult↗

PubMed1995

The effect of cooling and hypertonic exposure on murine oocyte function, fertilization, and development.

Several individual but related steps are involved in the cryopreservation process, including the addition of cryoprotectants at various temperatures, cooling to subzero temperatures, and long-term storage. The process is completed by rewarming and removal of cryoprotectants prior to a return to physiological conditions. In this series of experiments we have attempted to distinguish the effects of some of these procedures. Control, untreated ovulated mouse oocytes showed 95% in vitro fertilization (190/200) and 92% subsequent development to hatching blastocyst (184/200). Exposure of oocytes to either isotonic or hypertonic media at 37 degrees C did not significantly change the rate of fertilization (90%, 108/120; and 89%, 154/174, respectively) or subsequent embryonic development (85%, 102/120; and 82%, 143/174, respectively). Slow cooling in isotonic medium (-3 degrees C/min) to 0 degree C had no effect on the rate of fertilization (83%, 103/124), but rapid cooling (> 1000 degrees C/min) to 0 degree C resulted in a significant reduction in fertilization rate to 75% (151/202). When oocytes suspended in a hypertonic solution were cooled using slow or rapid rates, there were marked decreases in fertilization to 26% (61/231) and 56% (156/278), respectively. Subsequent embryonic growth was reduced to 15% (34/231) after slow cooling and 26% (72/278) after rapid cooling. Exposure of oocytes to glycerol at 37 degrees C and dimethyl sulfoxide at 0 degree C reduced the fertilization rate to 57% (67/118) and 73% (103/145), respectively, with a corresponding reduction in embryonic growth to 52% (61/118) and 65% (94/145), but there were no additional effects of cooling or hypertonic exposure after addition of cryoprotectants.

Animals↗

PubMed1995

Fetal lung maturation in congenital diaphragmatic hernia.

OBJECTIVE: Our purpose was to determine whether congenital diaphragmatic hernia is associated with abnormalities of fetal lung maturation. STUDY DESIGN: We measured surfactant protein A and saturated phosphatidylcholine in amniotic fluid from 19 pregnancies with a prenatal diagnosis of congenital diaphragmatic hernia (gestational age 16 to 40 weeks) and 48 control pregnancies (gestational age 16 to 39 weeks). Results were compared by analysis of covariance. RESULTS: Beyond 34 weeks of gestation there was a progressive rise in amniotic fluid surfactant protein A and saturated phosphatidylcholine in control pregnancies, whereas in most fetuses with prenatal diagnosis of congenital diaphragmatic hernia these values remained low (p < 0.01). Amniotic fluid surfactant protein A was lower in fetuses with congenital diaphragmatic hernia who died or required extracorporeal membrane oxygenation than in survivors treated with conventional management (4.9 +/- 2.9 vs 16.8 +/- 5.7 micrograms/ml surfactant protein A, respectively, p < 0.05 by Mann-Whitney U test). CONCLUSIONS: There are decreased surfactant components in amniotic fluid in many pregnancies complicated by congenital diaphragmatic hernia, which may reflect fetal lung immaturity or hypoplasia.

Amniocentesis↗

PubMed1995

Inhibition of T cell activation with a humanized anti-beta 1 integrin chain mAb.

The murine anti-CD29 mAb K20 (Mu-K20) is known to bind to the beta 1 chain of the human integrins and to inhibit activation and proliferation of T cells, implying an important potential for in vivo immunosuppression. However, use of K20 as an immunosuppressant drug would be impaired by the immunogenicity of mouse mAbs in man. We have therefore engineered K20 into (1) a mouse/human chimeric mAb (Ch-K20) that comprises the human kappa/gamma 1C regions and the K20 V regions; and (2) a humanized mAb (Hu-K20) combining the complementarity-determining regions (CDRs) of the K20 mAb with human framework (FR) and kappa/gamma 1 C regions. Both chimeric and humanized Abs were able to reproduce a range of functional properties of the original mouse mAb K20 (Mu-K20), namely, specific binding of CD29, inhibition of T cell proliferation and elevation of second messenger phosphatidic acid (PA) induced via CD3 in a soluble form, and activation of T cell proliferation in a cross-linked form. When compared to Ch-K20, the avidity of Hu-K20 was only slightly reduced. This demonstrates the feasibility of a successful humanization performed on the sole basis of the primary amino acid sequence analysis of the original mouse antibody V regions.

Amino Acid Sequence↗

PubMed1995

Sphingosine, oleylamine and stearylamine inhibit both CD11a/CD18-dependent and -independent homotypic aggregation: demonstration by cytofluorimetry.

An CD11a/CD18-dependent homotypic aggregation pathway is induced by triggering CD45 molecules on human thymocytes. By contrast, a CD11a/CD18-independent homotypic aggregation process is induced by triggering the CD99 molecule (E2, MIC2 gene product) expressed at the surface of either Jurkat T cells or human thymocytes. A new quantitative method based on FACS analysis of aggregated cells was used and allowed to show that both types of aggregation (CD11a/CD18-dependent and CD11a/CD18-independent) were inhibited with sphingosine, oleylamine or stearylamine. These three compounds had no effect on the expression of CD99, CD45, CD11a, CD18 or other [correction of others] known integrins expressed at the surface of the cells studied.

12E7 Antigen↗

PubMed1995

Health risk assessment of long-term exposure to non-genotoxic chemicals: application of biological indices.

For chemical pollutants, health risk assessment of long-term exposure is usually best realized through an epidemiologic approach which attempts to link cumulative levels of exposure to the potential for occurrence of early adverse effects. For some chemicals, however, the frequency of peak exposures may be more relevant for assessing the health risk than the integrated dose. In very few circumstances, biological exposure indices directly reflect the cumulative dose (e.g. PCB in blood). More frequently they are indicators of short-term interval dose but provided they have been measured with a sufficient frequency, their integration over the duration of exposure may represent a valid surrogate of the cumulative dose. This has been clearly demonstrated for lead or cadmium in blood. The selection of the appropriate biological effect markers for the study of the dose-effect/dose-response relationships is frequently a controversial issue when information on the mechanism of action of the pollutant is insufficient. In this case, the study of the health significance of the observed biological changes may be required for assessing a meaningful no-adverse-effect level. For example, in adult male workers moderate exposure to lead may affect the synthesis of vasodilatory prostaglandins in the kidney but presently there is no indication that this effect should be taken into account to define the acceptable occupational exposure level to lead because it is not associated with an impairment of the hemodynamic response of the kidney to an acute protein load. On the contrary, a low-molecular-weight proteinuria induced by cadmium may be predictive of an increased age-related decline of the glomerular filtration rate. Although the use of early biological effect markers for the study of the dose-effect or dose-response relationships in humans is probably less affected by selection biases than morbidity data, the possibility of such an interference cannot be excluded. For example, in the general population, the tubulotoxic effects of cadmium may occur at a lower body burden of the metal than in adult male workers. Whatever the adverse biological effect considered, the application of an uncertainty factor remains justified when extrapolating a no-effect level from adult male workers to the general population.

Adult↗

PubMed1995

Low-molecular-weight proteins as markers of organ toxicity with special reference to Clara cell protein.

Low-molecular-weight (M(r) between 5 and 40 kDa) proteins present several features related to their small size making them potentially interesting biomarkers of toxicity. They are readily exchangeable and might serve as peripheral indicators of toxic events in relatively inaccessible target organs. They have a short half-life in plasma and may thus respond to both acute and chronic toxic effects. Their catabolism takes place in the proximal tubule which is the segment of nephron which is the most vulnerable to toxic injury. Low-M(r) proteins have been used hitherto in toxicology mainly in relation to their renal handling, i.e. as markers of proximal tubule dysfunction or of glomerular filtration rate, e.g. beta 2-microglobulin (beta 2-m), alpha 1-microglobulin (alpha 1-m) and retinol-binding protein (RBP). The potential of low-M(r) proteins as biomarkers of toxicity might go beyond the field of nephrotoxicity, as suggested by our investigations on a new low-M(r) protein called protein 1 or Clara cell protein (CC16). CC16 is a 16-kDa protein synthesised by non-ciliated cells of the tracheobronchial epithelium, among which the Clara cells which, because of their high xenobiotic-metabolizing activity, are particularly vulnerable to a number of air pollutants. CC16 secreted in the respiratory tract diffuses passively by transsudation into the serum where it may mirror changes occurring in the lung. Recent studies on subjects exposed to lung toxicants (e.g. tobacco smoke and silica) suggest that CC16 in serum or bronchoalveolar lavage fluid is a sensitive marker of bronchial tree injury. CC16 is handled by the kidney as other low-M(r) proteins and may also be used to detect proximal tubule dysfunction. In this respect too, CC16 shows a unique sensitivity and can detect very subtle defects in proximal tubular dysfunction that remain undetected when screening is based on the assay of classical urinary low-M(r) proteins (i.e. beta 2-m, alpha 1-m or RBP).

Biomarkers↗

PubMed1995

Oleylamine and stearylamine increase phosphatidylserine synthesis in T cells by synergy with calcium ions.

Oleylamine and stearylamine, two cationic amphiphilic drugs, strongly increase phosphatidylserine synthesis in human T cells. The two compounds had little effect on either phosphatidylcholine or phosphatidylethanolamine synthesis. A decrease in the formation of phosphatidylethanolamine through decarboxylation of phosphatidylserine was observed, but this effect is only marginally involved in increased phosphatidylserine synthesis. The high incorporation of [3H]-serine into phosphatidylserine is a protein kinase C independent process and is due to a synergy of either oleyamine or stearylamine with calcium ions.

Amines↗

PubMed1995

Protein content in bronchoalveolar lavage fluid of patients with asthma and control subjects.

BACKGROUND: Secretory component (SC), Clara cell protein (CC10) and to some extent, IgM are proteins locally synthetized in airways. Albumin, alpha 2-macroglobulin and alpha 1-antitrypsin are mainly plasma proteins. In patients with asthma, blood proteins may occur in greater amounts in bronchoalveolar lavage fluid (BALF) than in control subjects because of plasma extravasation. These proteins were measured in BALF to define markers of local synthesis and plasma exudation. METHODS: Twenty-four patients with asthma (mean age, 40 +/- 3.1 years) and 24 control subjects (mean age, 29 +/- 11 years) were tested. Five aliquots of saline solution (50 ml) were instilled, and the recovered BALF was stored. Clara cell protein was measured by a sensitive immunoassay technique based on the agglutination of latex particles. SC, immunoglobulins, alpha 2-macroglobulin, alpha 1-antitrypsin, and albumin were measured by an immunoradiometric assay. Protein concentrations were normalized to albumin. RESULTS: In BALF from patients with asthma there was a significant increase in alpha 2-macroglobulin and IgM and a significant decrease of SC, alpha 1-antitrypsin, and Clara cell protein compared with control subjects. Also, the ratio to albumin was significantly increased for alpha 2-macroglobulin and IgM and decreased for SC. There was no correlation between the severity of asthma and the amount of proteins. CONCLUSIONS: BALF protein content is significantly different in patients with asthma and control subjects, for proteins produced locally and derived from plasma.

Adolescent↗

PubMed1995

Low molecular weight proteinuria in Chinese herbs nephropathy.

Urinary excretion of five low molecular weight proteins (LMWP) [beta 2-microglobulin (beta 2m), cystatin C (cyst C), Clara cell protein (CC16), retinol-binding protein (RBP) and alpha 1-microglobulin (alpha 1m)], albumin and N-acetyl-beta-D-glucosaminidase (NAG) were quantified in 16 patients who followed a weight reduction program which included Chinese herbs, which have been incriminated in the genesis of Chinese herbs nephropathy (CHN). An additional group of four patients transplanted for CHN were investigated. Urinary data were obtained for comparison purpose in five groups of proteinuric patients: two groups with normal serum creatinine (SCr) and glomerular albuminura [12 patients with diabetes mellitus and microalbuminuria (DN), 10 patients with primary nephrotic syndrome (NS)]; two groups with normal SCr and toxic nephropathy [6 patients with analgesic (AN), 9 patients with cadmium nephropathy (CdN)]; and one group of seven patients with glomerular diseases and increased SCr (GN). Patients were classified according to serum level S beta 2m to take into account the possibility of overflow proteinuria at S beta 2m > or = 5 mg/liter. Three patients (CHN0) with a S beta 2m < 5 mg/liter, had a normal urinary protein pattern including NAG and a normal S beta 2m. Eight patients (CHN1) with a S beta 2m < 5 mg/liter had various abnormalities of their urinary protein pattern. In four of them (CHN1a) only beta 2m, RBP and CC16 were increased while total proteinuria and SCr were normal. In the other four (CHN1b and c) albumin, cyst C, alpha 1m and NAG were also elevated, while total proteinuria and SCr were moderately raised. Five patients (CHN2) with a S beta 2m > or = 5 mg/liter had a markedly increased excretion of all LMWP, albumin and NAG (CHN1 vs. CHN2, P < 0.05) as well as a further increase in total proteinuria and SCr. The urinary LMWP/albumin concentration ratio was strikingly higher in CHN patients than in patients with glomerular albuminuria (CHN1 vs. DN and NS, P < 0.01) or moderate renal failure with elevated S beta 2m level (CHN2 vs. GN, P < 0.01), confirming the existence of a tubular proteinuria independent of glomerular albuminuria or overflow proteinuria. A similar proteinuria pattern was present in the two toxic nephropathies (CdN and AN). This pattern was no longer recognizable after transplantation. In conclusion, CHN exhibits various profiles of tubular proteinuria which are the hallmarks of the disease. This pattern is still detectable in patients with renal failure and/or glomerular albuminuria. It is identical to that observed in cadmium and analgesic nephropathies. It does not recur after transplantation. Its most sensitive and reliable marker is a raised urinary level of CC16 or RBP.

Adult↗

PubMed1995

Factors influencing serum levels and peritoneal clearances of low molecular weight proteins in continuous ambulatory peritoneal dialysis.

To identify the factors influencing the serum concentrations and the peritoneal clearances of low molecular weight proteins (LMWP), fourteen patients on continuous ambulatory peritoneal dialysis (CAPD) for 1 to 57 (mean 9.4) months were examined. LMWP [Beta 2-microglobulin (Beta 2m, molecular wt 11.8 kD), cystatin C (cyst C, molecular wt 13.2 kD), Clara cell protein (CC16, molecular wt 15.8 kD), retinol-binding protein (RBP, molecular wt 21 kD) and alpha 1-microglobulin (Alpha 1m, molecular wt 33 kD)] and high molecular weight proteins (HMWP) [albumin (Alb, molecular wt 66 kD), immunoglobulins (IgG, molecular wt 170 kD and IgM, molecular wt 600 kD) and alpha 2-macroglobulin (Alpha 2m, molecular wt 718 kD)] were determined by latex immunoassay in the serum and dialysate collected during the peritoneal equilibration test (PET) with 2.27% dextrose (N = 14), and in dialysate from 56 standard exchanges, performed the day preceding PET, with 1.36% (N = 21), 2.27% (N = 23) and 3.86% (N = 12) dextrose. Determinants of serum concentrations and transperitoneal clearances of the proteins were traced by stepwise regression analysis using as possible contributors age, sex, residual diuresis, duration of the therapy (for serum concentrations), molecular radius of the protein and peritoneal membrane characteristics (for peritoneal clearances). LMWP serum concentrations were markedly increased whereas serum concentrations of HMWP were within the normal range. Residual diuresis, age and duration of dialysis emerged as significant determinants of serum concentration of some proteins, whereas transperitoneal clearance was dependent mainly on the size of the protein and, only for HMWP, on the dwell time. Residual diuresis was inversely related to the serum concentrations of four LMWP. Age was negatively correlated to the serum concentrations of beta 2m, CC16 and RBP. RBP and Alb were the only proteins whose serum concentration significantly decreased with time on CAPD. The relationship between peritoneal clearance and M(r) shows two slopes suggesting the existence of two populations of pores in the peritoneal capillary wall: small pores of about 20 to 25 A radius and large pores exceeding 100 A radius. A long dialysis cycle is associated with significant loss of HMWP only. Daily peritoneal protein losses, in mg (mean +/- SD), were as follows: Beta 2m 43.4 +/- 4.5; cyst C 9.6 +/- 1.8; CC16 1.8 +/- 0.3; RBP 58.9 +/- 11.1; Alpha 1m 149.5 +/- 15.7; Alb 6570 +/- 530; IgG 750 +/- 111; IgM 46.4 +/- 14.9; and alpha 2m 67.0 +/- 12.7. In conclusion, LMWP concentrations in the serum of patients on CAPD were markedly increased and influenced mainly by patient-related factors (residual diuresis and age). Serum albumin and RBP declined with the duration of dialysis. Peritoneal protein loss was determined by the size of the protein and, for large proteins, by the dwell time. The peritoneum behaves as a membrane with at least two populations of pores.

Adult↗

PubMed1995

Vitrification of human oocytes following minimal exposure to cryoprotectants; initial studies on fertilization and embryonic development.

Investigations were made into the low temperature preservation of pre-ovulatory human oocytes by vitrification using a method of brief exposure of the oocytes to the vitrification solution at room temperature. Assessments of morphological survival, fertilization and embryonic development were recorded. All those oocytes exposed to the vitrification solution alone were morphologically normal and 86% of them were fertilized after incubation with spermatozoa. All the fertilized ova (86%) underwent cell division. Following cooling to -196 degrees C, morphological survival (65%) and fertilization (45%) rates remained high. However, in all vitrified oocytes, embryonic cell division and further development were inhibited. From our study it appears that fresh human oocytes can be vitrified using only brief exposure to cryoprotective agents and survive to undergo fertilization. However, progress remains to be made in achieving further embryonic development.

Cell Survival↗