Expression of the glycoprotein of viral haemorrhagic septicaemia virus (VHSV) on the surface of the fish cell line RTG-P1 induces type 1 interferon expression in neighbouring cells

In the present study using a luciferase/Mx promoter reporter system, it was shown that the rainbow trout gonad cell line (RTG-P1), a fibroblastic cell line, produces IFN when transfected with a plasmid encoding the glycoprotein of VHSV but not with plasmid vector alone. Only a small percentage of the cells expressed the G protein on the surface membrane as indicated by immunostaining of transfected cells. When transfection was performed in the presence of monoclonal antibodies (Mab) to the glycoprotein, the production of interferon mRNA transcripts was reduced by over 50%. This indicates that the surface expression of G protein was the major mechanism of interferon induction and that most of the interferon was being expressed by cells neighbouring the transfected cells.

An assessment of immunostimulants as Mx inducers in Atlantic salmon (Salmo salar L.) parr and the effect of temperature on the kinetics of Mx responses

The aims of this study were (i) to identify alternative Mx stimulatory compounds in Atlantic salmon (Salmo salar L.) and to characterise the kinetics and intensity of the stimulated responses and (ii) to investigate the effect of temperature on such responses by semi-quantitative RT-PCR. Mx transcripts were measured in Atlantic salmon parr kept at 14 degrees C and injected with either LPS, the synthetic double-stranded polyribonucleotide poly I:C, Vibrio anguillarum serotypes I and II-ordalii bacterin, beta-glucan, whole yeast cells or yeast RNA. Sampling periods lasted until transcripts were undetectable or up to three weeks after immunisation. The effect of temperature on poly I:C-induced Mx response was studied by injecting parr kept at 6 degrees C. Newly hatched salmon fry were immersed once, twice or three times in the Vibrio bacterin diluted five or 10 times and sampled for three weeks. None of the yeast compounds induced Mx expression in Atlantic salmon parr. LPS induced a very low Mx response 2 and 3 days after injection. The Vibrio bacterin administered by injection in parr (but not by immersion in fry) resulted in strong Mx induction on days 2 and 3, disappearing by day 6. Poly I: C-induced Mx responses that were more intense and longer lasting than those induced by the bacterin, peaking on day 3 and lasting over 6 days, disappearing by day 9 at 14 degrees C. Lower temperature caused a longer lasting Mx response to poly I:C (at least 21 days), which peaked on days 7-14, with a similar intensity and no delayed onset as compared with the response at 14 degrees C. However, some toxicity of the poly I:C was indicated in treatments at 6 degrees C.

Recursive surface impedance matrix methods for ultrasonic wave propagation in piezoelectric multilayers

Two recursive surface impedance methods are described for acoustic wave propagation in multilayered piezoelectric structures. Both methods have the advantage of conceptual simplicity and flexibility brought about by the transfer matrix method. Moreover they do not have a priori computational limitations with respect to the total number of layers of the stratified structure nor with respect to the thickness of individual layers; nor is the computational stability limited by the frequency range. For both methods, numerical simulations were carried out in order to illustrate their performances and robustness when combined with suitable recursive numerical algorithms.

DNA vaccination against viral haemorrhagic septicaemia (VHS) in rainbow trout: size, dose, route of injection and duration of protection-early protection correlates with Mx expression

Rainbow trout of different sizes (10 and 100g) were injected intramuscularly (i.m.) or intraperitoneally (i.p.) with different doses (range 10 ng-10 microg) of a viral haemorrhagic septicaemia (VHS)-DNA vaccine (pcDNA3vhsG). As controls, fish were injected with the pcDNA3 plasmid alone, or with inactivated VHS virus. Fish were challenged at different times post-vaccination (p.v.) to assess protection. At certain times p.v., serum samples were analysed for neutralising antibody and liver tissue was analysed for Mx mRNA expression. A DNA dose of 0.5 microg injected by the i.m. route induced protection in fish of all sizes in challenges performed either 1 or 4 weeks p.v. This dose also conferred effective protection up to 9 months p.v. in fish >100 g. With lower doses of DNA (0.1 and 0.01 microg) and challenge at 4 weeks p.v., 10 g fish were partially protected but protection was not observed in 100 g fish. Vaccination by the i.p. route induced no or lower levels of protection compared with the i.m. route. Fish vaccinated with 0.5 microg DNA i.m. had no detectable serum neutralising antibody (NAb) at 4 weeks p.v. (with the exception of a single 10 g fish) but antibody was detected at 8 weeks and 6 months p.v. but not at 9 months p.v. However, cohorts of these fish showed effective protection at all timepoints. Lack of detectable levels of NAb (at 9 weeks p.v.) despite partial protection in challenge at 4 weeks p.v. was also observed with 0.01 microg doses of DNA i.m. NAb was detected in sera of fish at 8 weeks after vaccination with 0.1 microg i.m. but not in fish vaccinated with doses of 0.01-0.5 microg i.p. Early protection (1 week p.v.) correlated with elevated Mx gene expression.

Is a cooled tip catheter the solution for the ablation of the cavotricuspid isthmus?

To test the theoretical superiority of irrigated tip catheters to achieve complete cavotricuspid isthmus block, a 4-mm cooled tip catheter was compared to a conventional 8-mm tip catheter with a double temperature sensor in the cavotricuspid isthmus (CTI) ablation. The study prospectively enrolled 60 patients (47 men, mean 65 +/- 10 years) with common flutter divided in group 1 (n = 30) assigned to an 8-mm tip catheter versus group 2 (n = 30), assigned to an internal circuit, irrigated tip catheter. Linear radiofrequency applications were performed in a point-by-point protocol to achieve complete CTI block. Complete CTI block was achieved in 29 patients in each group. Mean durations of procedure and fluoroscopy were 91 versus 90 and 40 versus 33 minutes in group 1 versus 2, respectively, (NS). The mean number/patient of RF pulses to interrupt atrial flutter was four in group 1 and eight in group 2 (P = 0.034), and 11 and 13, respectively, to interrupt CTI conduction (NS). The total energy delivered was similar in both groups (29,237 vs 23,236 W/s, NS). CTI ablation with a conventional 8-mm tip catheter versus an irrigated tip catheter was associated with similar success rates, procedure duration, and fluoroscopic exposure. The technical complexity of the cooled tip catheter renders it less competitive.

[The new German law on foreigners' residency: change and continuity]

"This article about the new German law on foreigners which came [into] force on 1-1-91, emphasizes the changes made to the 1965 law and the differences between the situations of foreigners in France and Germany. Two changes of attitude are to be noted: the introduction of a right of residence and of an 'earlier' naturalisation. This naturalisation which is limited to young foreigners and foreigners who have been living in Germany for a long time, finally gets away from the principles of racial...tendencies [i.e.] the belonging to the socio-cultural German Community." (SUMMARY IN ENG AND GER)

Differentiation of the P-gp and MRP1 multidrug resistance systems by mobile lipid 1H-NMR spectroscopy and phosphatidylserine externalization

We have previously demonstrated that proton NMR spectra of fatty acid chains in erythroleukemia K562 wild-type cells and their MDR1 counterparts show variations related to the phenotype over-expressing the P-glycoprotein (P-gp). Human lung cancer cells whose multidrug resistance (MDR) counterparts over-express the multidrug resistance-associated protein MRP1 have not yet been studied by NMR. Both P-gp and MRP1 belong to the same ATP-binding cassette transporter superfamily. A comparison of NMR spectra from both these multidrug-resistance phenotypes showed that the results previously obtained on the MDR1 family are not valid for MRP1. Furthermore, flow cytofluorimetry studies with external phosphatidylserine labelling showed that P-gp and MRP1 overexpressions have strong but differentiated effects on cell lipid pools.

Red and white muscle development in the trout (Oncorhynchus mykiss) as shown by in situ hybridisation of fast and slow myosin heavy chain transcripts

The axial muscle of most teleost species consists of a deep bulk of fast-contracting white fibres and a superficial strip of slow-contracting red fibres. To investigate the embryological development of fast and slow muscle in trout embryos, we carried out single and double in situ hybridisation with fast and slow myosin heavy chain (MyHC)-isoform-specific riboprobes. This showed that the slow-MyHC-positive cells originate in a region of the somite close to the notochord. As the somite matures in a rostrocaudal progression, the slow-MyHC-positive cells appear to migrate radially away from the notochord to the lateral surface of the myotome, where they form the superficial strip of slow muscle. Surprisingly, the expression pattern of the fast MyHC showed that the differentiation of fast muscle commences in the medial domain of the somite before the differentiation and migration of the slow muscle precursors. Later, as the differentiation of fast muscle progressively spreads from the inside to the outside of the myotome, slow-MyHC-expressing cells become visible medially. Our observations that the initial differentiation of fast muscle takes place in proximity to axial structures and occurs before the differentiation and migration of slow muscle progenitors are not in accord with the pattern of muscle formation in teleosts previously described in the zebrafish Danio rerio, which is often used as the model organism in fishes.

The rainbow trout (Oncorhynchus mykiss) Mx1 promoter. Structural and functional characterization

Mx1 gene expression was studied in the rainbow trout (Oncorhynchus mykiss) gonad (RTG) (fibroblast) cell line. RT-PCR analyses showed that both poly I:C and interferon containing supernatants induced expression of Mx1 in RTG cells. Kinetic analyses suggest that poly I:C acts indirectly through the production of interferons (IFN), as shown in other studies. By gene walking with trout genomic DNA the regulatory sequence of the Mx1 gene was cloned and sequenced. Sequence analysis showed that the 5' flanking region has a structure, which is typical for an interferon-induced gene promoter. Relative to the transcription start, it has a TATA box at -29 to -25, a 13 nucleotide interferon response element (ISRE) between -101 to -89, and a Sp1 binding site at -382 to -374. This region, with a single ISRE, is enough to induce strong expression of a luciferase reporter gene after stimulation of RTG cells with poly I:C. A time-course of induction of this reporter construct showed maximal expression (22-fold increase) after incubation with 100 microg mL(-1) poly I:C for 48 h. An optimized method of transient transfection of RTG cells is also described.

Expression of MAGE genes in esophageal squamous-cell carcinoma

The genes MAGE-1, -2, -3 and -4 are expressed in tumors of different histological types, but not in normal tissues, with the exception of testis and placenta. Short peptides derived from MAGE-1 and MAGE-3 gene products are recognized by cytolytic T lymphocytes when presented by HLA-class-I molecules, and represent potential targets for specific immunotherapy. We have determined whether esophageal carcinoma patients should be eligible for MAGE-peptide-based vaccine therapies. The expression of genes MAGE-1, -2, -3 and -4 in tumor samples was assessed by reverse-transcription and polymerase-chain-reaction amplification. Out of the 49 esophageal squa-mous-cell carcinomas studied, 53% expressed MAGE-1, 49% MAGE-2, 47% MAGE-3 and 71% MAGE-4. Eighty-four percent of the tumors expressed one or more of the four MAGE genes. Owing to the high incidence of MAGE gene expression in esophageal squamous-cell carcinoma, a large proportion of patients could be suitable candidates for immune therapies involving tumor-specific antigens encoded by MAGE genes.

Fate of mouse macrophages radiolabelled with PKH-95 and injected intravenously

Mouse macrophages purified by elutriation from thioglycollate-induced peritoneal exudate cells were labelled with indium-111-oxine and injected intravenously into mice. A substantial amount of unbound radioactivity remained in the circulation, suggesting that the radionuclide was not stably bound to the cells. Culture experiments with radiolabelled cells showed that indium-111 was released in the medium. Another cell marker, PKH-95, an iodine-125-labelled aliphatic compound insertable into the cell membrane, bound more stably than indium-111. Five minutes after injection of 125I-PKH-95-labelled macrophages, about 98% of the cells were in a non-circulating pool. It was checked that PKH-95 labelling did not compromise the viability and functions of the macrophages and that autologous erythrocytes and blood mononuclear cells labelled with PKH-95 remained in the circulation after i.v. injection. One hour after injection, 125I-PKH-95-labelled macrophages were distributed mainly in lung (36%), liver (19%) and spleen (5%). Subsequently, radioactivity decreased in the lung while increasing in liver, spleen and in an artificially induced footpad inflammation. The radioactivity accumulation in the inflammation persisted at least for 7 days. It represented a small proportion of radioactivity injected (0.2%) but was trapped very specifically in the inflammation. This raised the hypothesis that macrophages of the non-circulating pool could be released in the circulation and recruited into the inflammation with slow kinetics.

Puerperal presentation of a living abdominal pregnancy

BACKGROUND

Abdominal and heterotopic pregnancies appear to be increasing in incidence.

CASE

We report a case of puerperal presentation of a living heterotopic pregnancy in an African woman. The patient presented 6 days postpartum with fever and abdominal pain. The correct diagnosis of heterotopic pregnancy was not considered, and for 9 days she was treated for presumed puerperal sepsis. It was only upon abdominal x-ray that the diagnosis was made. The patient underwent laparotomy with delivery of a living male neonate weighing 2000 g. He subsequently died of respiratory failure on day 3 of life.

CONCLUSION

Although still rare, the increasing incidence of abdominal pregnancies in both developed and developing countries mandates awareness of this diagnosis, particularly in pregnant or postpartum women presenting with abdominal pain.

Uptake and release of radiolabelled monoclonal antibody Po66 by multicellular aggregates obtained from a lung squamous carcinoma cell line

Po66, a monoclonal antibody (MAb) directed against lung squamous cell carcinoma, has been shown, when injected intravenously, to be retained for a long time in tumors. This property encouraged trials to use Po66 as an agent of metabolic radiotherapy. The suitability of multicellular spheroids to reproduce the in vivo conditions of irradiation of tumors by Po66 was investigated in the present work. Spheroids were formed from the lung carcinoma cell line SK-MES-1. They resembled morphologically small carcinoma nodules with desmosome-like intercellular junctions at the periphery and a central necrotic core. The cells expressing the antigen recognized by Po66 had a heterogeneous distribution and were predominant in the outer layers of the cell aggregates. Spheroids were exposed to radiolabelled Po66. The MAb diffused slowly and reached a maximal incorporation after 4-12 hours incubation. A control unrelated antibody did not penetrate appreciably. Autohistoradiographic experiments suggested that the antibody accumulated in most cells expressing the antigen. The rate of MAb release from the spheroids was very low (T 1/2 = 163 h). Taken together, the data indicate that spheroids might be a relevant model to investigate the parameters controlling Po66-mediated immunoradiotherapy.

111Indium-F(ab)'2-NCA 102 monoclonal antibody: in vitro study of a specific agent for the detection of inflammatory foci

A new antigranulocyte antibody was evaluated in vitro for the detection of inflammatory foci in man. The specificity for polymorphonuclear cells (PMN) of NCA 102, an anti-NCA 95 monoclonal IgG1, was determined with immunohistochemical and cytofluorometrical tests. Its affinity, assessed by Scatchard analysis, was 1.1 x 10(9) L/mol and the number of epitopes per granulocyte reached about 10(5). The biological properties of PMNs incubated with NCA 102 were not inhibited even when coupled with DTPA. A F(ab)'2 fragment was radiolabelled with 111Indium and incubated in the presence of whole blood. More than 65% radioactivity was selectively taken up by the PMN population. These findings indicated that NCA 102 antibody is suitable for sepsis detection.

Effect of an anti-HLA class I monoclonal antibody on the antigenic and transcriptional expression of HLA class I genes in U937 cells

The phenomenon of antigenic modulation was studied in the histiocytic lymphoma line U937. A redistribution of cell surface HLA antigen after incubation of U937 cells with the monomorphic anti-HLA class I monoclonal antibody W6/32 was demonstrated by immunofluorescence analysis. As assessed by hybridization of RNA obtained from W6/32-treated U937 cells with a probe corresponding to the alpha 3 domain of HLA Cw3, prolonged W6/32 incubation (24 to 72 hours) induced a decrease in HLA class I transcript abundance. This decrease was about 25% as compared with untreated control cells. These data indicate that W6/32 incubation can induce changes in HLA class I gene expression not only at the antigenic but also at the transcriptional level. Possible implications for the molecular basis of antigenic modulation are discussed.

Monoclonal antibody AP-282 recognizes a marker for human polymorphonuclear granules

Hybridoma AP-282 was produced by fusing mouse plasmacytoma cells with splenocytes of mice immunized against purified human polymorphonuclear cells. The secreted monoclonal antibody (MAb), AP-282, a mouse IgG1, was found to react strongly with all neutrophilic granulocytes, their bone marrow precursors, weakly with blood monocytes and not with eosinophils. The antigen was resistant to formalin fixation but was destroyed by exposure to fixatives containing acetic acid. Using the APAAP technique, antibody AP-282 strongly labelled neutrophils on sections of frozen cut or paraffin embedded tissues. No staining was seen of non hematopoietic tissues. AP-282 recognized an internal antigen associated to cytoplasmic granules. Chemical investigations on dot blots of whole or of purified cellular extracts indicated that the antigen idenfied by MAb AP-282 was different from those recognized by usual antigranulocyte antibodies, i.e. myeloperoxidase, elastase, cathepsin G and lactoferrin. Thus, antibody AP-282 constitutes a new cytoplasmic marker of neutrophils.

Activation of mouse macrophages by muramyl dipeptide coupled with an anti-macrophage monoclonal antibody

A rat IgG2a monoclonal antibody (mAb3A33) directed against the mouse Mac-1 antigen was conjugated with muramyl dipeptide (MDP) by using an intermediate polymer; under such conditions 75 MDP molecules were bound to one antibody molecule. A poly(L-lysine) polymer substituted with muramyl dipeptide and 3-(2-pyridyldithio)propionyl residues were prepared, the remaining lysine epsilon-amino groups were acylated with D-gluconolactone, leading to a neutral polymer; then a few polymer conjugates were coupled to mAb3A33 via a disulfide bridge. The binding capacity of the monoclonal antibody was preserved after conjugation with MDP-polymer molecules. Mouse peritoneal macrophages, incubated for 24 h with MDP-mAb3A33 conjugate became cytostatic against P815 mastocytoma cells, whereas unconjugated mAb3A33 and MDP-bound to a nonspecific rat IgG2a were ineffective. An enhancement of the cytostatic activity induced by MDP-mAb3A33 conjugate was obtained in the presence of gamma-IFN. These results show that several tens of MDP molecules can be linked to a macrophage-specific monoclonal antibody by using a neutral intermediate polymer without impairing the binding antibody capacity and that this type of MDP conjugate can efficiently activate macrophages and therefore could be the basis of the development of new antitumor therapy.

Monoclonal antibody AMH152 reacts with human monocytes in culture and with inflammatory macrophages

Monoclonal antibodies (mAb) raised against human peritoneal macrophages were selected for their non-reactivity with freshly sampled blood cells. One of these mAb, AMH152, initially non-reactive, bound to monocytes after 18 h of culture, a property which was not shared by an unrelated antibody of the same isotype (IgG1). The induction of the expression of the antigen detected by AMH152 on monocytes in culture was not influenced by the addition of serum or by the substrate used, plastic that favoured adhesion or teflon bags. Overnight incubation at 4 degrees C in adhesion conditions did not enable antigen expression. A 1-h treatment with phorbol myristate acetate or formyl-methionyl-leucyl-phenylalanine did not increase AMH152 binding. Culturing monocytes with cycloheximide tended to inhibit antigen expression. These observations suggested that antigen expression represents an active phenomenon, requiring protein synthesis. The antigen recognized by mAb AMH152 could be visualized on sections of formalin-fixed and paraffin-embedded tissues. Macrophages of healthy lymphoid organs and tissues that expressed CD68 antigen failed to bind AMH152. In contrast, chronic inflammatory lesions, like those of sarcoidosis, tuberculosis and cat scratch disease, contained epithelioid and multinucleated giant cells that reacted with AMH152. In serous exudates of cancer metastases, 10-40% of macrophages were also stained. The antigenic material was essentially present at the cell periphery. Thus, mAb AMH152 recognized a surface antigen, detectable on paraffin-embedded tissue sections, and which accompanied differentiation of monocytes into inflammatory cells. The expression of this antigen on monocytes in culture suggests that these cells underwent an activation process, even when maintained for some hours in teflon bags and in a serum-free medium.

Immunoscintigraphy of human lung squamous cell carcinoma using an iodine-131 labelled monoclonal antibody (Po66)

Monoclonal antibody (McAb) Po66 has been obtained by immunisation of mice against a human lung squamous cell carcinoma. The in vitro reactivity of the antibody with cancer cells and its ability to localise in human lung cancer xenografts growing in nude mice have been reported earlier. Presented here is the first clinical evaluation of the antibody for scintigraphic detection of tumours. Thirty-three patients with histologically confirmed primary non-small cell lung carcinoma were investigated. Twenty-seven of them were explored at the preoperative stage and six at 6 months after surgery. Biodistribution results were obtained from seven operated patients by combining injections of 131I-radiolabelled Po66 and of 125I-labelled unrelated immunoglobulin. The localisation index was three times higher for this specific antibody. Immunoscintigraphy detected 78% of primary tumours and 100% of recurrences. In this short series of patients, immunoscintigraphy proved helpful in the assessment of tumour spread in four patients by visualising localisations in the mediastinum or the contralateral lung which the CT scan had failed to demonstrate. Immunoscintigraphy was also more efficient than plain chest X-ray for the detection of local tumour recurrences.

[Frontonasal dysplasia or the median cleft face syndrome: a case report]

Frontonasal dysplasia (FND) is a condition with a more or less severe ocular hypertelorism and, sometimes, a narrowing of the palpebral fissures. The nose is broad and flattened with clefting; it may be bifid or completely divided in two halves. In extreme cases, the central nervous system is concerned and there is a mental deficiency. There is no coronal craniosynostosis in pure FND. Other malformations can be observed. Among the cases reported in the literature, most of them are sporadic but they may be familial. We report here a sporadic case of F.N.D. in which scan examination of the brain shows a possible cephalocele. The literature is briefly reviewed.

Blood clearance and organ distribution of intravenously administered polymethacrylic nanoparticles in mice

Polymethacrylic nanospheres (mean diameter 0.25-0.30 microns), prepared by aqueous emulsion copolymerization, were developed as a new site-specific drug delivery system. The nanoparticles were labeled either with indium-111 or iodine-125, and after a single iv injection of labeled particles into mice, their blood clearance and organ distribution were analyzed. A rapid clearance of 111In-labeled nanoparticles from the blood circulation to the mononuclear phagocyte system (MPS) was visualized using external scintigraphic imaging. From 10 to 60 min, radioactivity measurements in blood and organs (liver, spleen, kidneys, lungs, heart) showed that the 125I-labeled nanospheres were rapidly removed from the bloodstream (distribution half-life approximately 3-5 min) and mainly deposited in the liver (60% of the administered dose, 10 min after administration). Up to 1 h, radioactivity in heart and lungs remained insignificant, while in the kidneys, radioactivity levels increased from 8 to 11%.