Assessment of gastrointestinal permeability to small marker probes in the preruminant calf

The intestinal permeability to markers was assessed in preruminant calves fed different milk substitutes containing skimmed milk powder or whey and soyabean products of differing antigenic activity as the protein sources. In Experiment 1, the 6 h urinary excretion of lactulose transiently decreased with the antigenic soyabean product but not that of sucrose of D-mannitol. In Experiment 2, the 6 h urinary excretion of sucrose and D-mannitol averaged 1-3%, regardless of age and dietary treatment. Cr-EDTA was recovered at rates of 2 and 4% after 6 and 24 h of urinary collection, respectively. The 24 h excretion of Cr-EDTA was lower in the calves fed the antigenic flour than in the controls after 2 weeks of experimental feeding (2.9 vs 6.0%, P < 0.05) but not thereafter. This transient decrease was also observed using D-xylose with the antigenic flour and with the non-antigenic concentrate (17 and 22% respectively vs 37%, P < 0.05). The present markers, including sucrose, may be suitable for assessing intestinal permeability in the calf even though excretion rates differed from one marker to another. Changes in the intestinal permeability to antigenic soya were of low magnitude and were only transiently detected when measured using lactulose, Cr-EDTA or D-xylose, probes which were therefore more sensitive than sucrose or D-mannitol.

cAMP/ATP relationship in the activation of trout sperm motility: their interaction in membrane-deprived models and in live spermatozoa

Live trout spermatozoa initiate flagellar motility for only a short period (30 sec at 18 degrees C) during which their mean beat frequency decreases steadily from 60 to 20 Hz. Motility then stops abruptly. Investigations of the activation of movement in demembranated sperm points to cyclic-AMP being necessary for reactivation (half effect at 0.5 microM) in some conditions. cAMP acts mainly by increasing the percentage of motile cells and not the beat frequency (BF) of the flagellar axoneme. Dibutyryl cAMP does not initiate movement or prolong motility of live sperm. The initiation of movement of demembranated trout sperm was investigated in various incubation conditions relative to previous phases of in vivo movement and to ATP concentration. In the absence of cAMP and in the presence of ATP lower than 25 microM, all sperm cell models were active with BF up to 15-20 Hz whatever their previous physiological conditions. In contrast, at ATP concentrations above 100 microM, the fraction of active spermatozoa decreased proportionally but the BF of the active ones increased so that, at 1 mM ATP, only 5% were active but with a BF of 65 Hz: the addition of cAMP up to 20 microM restored activity to 100% sperm models with a similar BF of 65 Hz. At ATP concentrations higher than 25 microM, cAMP was necessary in a concentration dependent manner in the reactivation, but not in the demembranation medium. This dependence was found to be unrelated to a previous in vivo phase of movement. The antagonistic effects of ATP vs. cAMP were tested at various concentrations of both nucleotides: the apparent affinity for cAMP, measured as the concentration restoring movement of 50% cell models, was decreased from 15 nM at 0.1 mM ATP to 0.5 microM at 1 mM ATP; conversely, the affinity for ATP, measured as the concentration giving rise to the half maximal beat frequency, was not significantly affected when the concentration of cAMP was raised to 0.5 mM. Preincubation with phosphodiesterase (PDE) resulted in motility of 100% of sperm models even at low ATP concentration. This tends to show that cAMP must be constantly present to sustain motility.

Developments in residue assay and metabolism study of growth-promoters by mass spectrometric analysis

The French national reference laboratory, for the control of growth-promoter residues, has developed routine methods of multiresidue analysis. These are mainly for the determination of beta-agonistic and steroid compounds. Apart from this regulatory activity, some research into growth-premotor metabolism and assay has also been carried out. This research concerns the method development of assay and metabolism studies of new compounds, including in vitro metabolism studies on cell (mainly hepatocytes) cultures, as well as studying the organic synthesis of new compounds and metabolites. Three examples of the different areas of research are presented here: the metabolism study of 4-chlorotestosterone in cattle; a methodological study on beta-agonists assay by mass spectrometry; and a residue study of beta-agonists in edible tissues.

Role of new allergens and of allergens consumption in the increased incidence of food sensitizations in France

Food allergy is a group of distinct clinico-pathological entities that have an immunological basis in common, and in which an abnormal or exaggerated immunological response to a specific food leads to disease. Some clinical pictures involving multiple organ system (anaphylaxis) are potentially fatal. The data on the incidence, prevalence, mortality rate and food products involved in food-induced anaphylaxis and the evolution of food sensitization compared with changes in eating habits are not very reliable. In the present study we analysed, over a period of 9 years (1984-1992), a group of 580 patients with pathological reactions to foods, 60 of which presented severe, near-fatal reactions. We sought the etiologic components and food sensitization in comparison with the principal tendencies of food consumption in France. Food products most frequently incriminated in anaphylactic reactions are not of a primary nutritional importance: celery (30%), crustaceans (17%), fish (13%), peanuts (12%), mango (6%), mustard (3%), but they are often hidden allergens in commercial foods. The sensitization to food products in the group of 580 patients reveals, in decreasing order of frequency: wheat (39%), peanuts (37%), crab (34%), celery (30%), soy (30%). Compared with previous data, the frequency of sensitization to different foods has changed; for instance, the sensitizations to wheat, soy, peanuts, celery, mustard, rice, are definitely increasing. The increased consumption and more attentive clinical research may be the reasons for this evolution. For products such as egg and pork, the data are stable and parallel with consumption, whilst for other products like milk and other dairy products, the increased consumption is accompanied by a decrease of the incidence of sensitization. The reactivity to some allergens may be affected by the way of preparing the food.

Recognition of Leptospira interrogans antigens by vaccinated or infected dogs

Antigenic recognition of leptospiral antigens by vaccinated or infected dogs was studied by microagglutination test (MAT) and by western blots. In western blots, serovar specific antigens detected by MAT migrated in the 18-31 kDa zone. The 25-31 zone seemed to be linked to antigens indicating virulence of the strain. These antigens are LPS. The first antibodies made after infection are produced against LPS migrating in the 14 kDa zone. Many protein antigens are common in leptospires belonging to different serogroups. Virulent strains exhibited specific antigens in the 45 and 32-34 kDa zones.

[Uncommon cardiac manifestations disclosing pheochromocytoma. Apropos of 3 cases]

The diagnosis of pheochromocytoma is usually considered in the presence of permanent hypertension with exacerbations. However, pheochromocytoma may be responsible for a varied range of adrenergic symptomatology and hemodynamic equilibrium may be threatened by the spontaneous or induced massive release of pressor amines. Three cases form the basis of a description of unusual situations: acute pulmonary edema, acute circulatory failure and myocardial infarction with normal coronary vessels. The divercity and severity of these clinical situations are such that the possibility should always be suspected when confronted by any cardiomyopathy without obvious etiology, in particular in a hypertensive patient. The only treatment remains ablation of the tumour and diagnosis as an emergency is based, apart from history, on ultrasonography and/or abdominal CT scan and assay of urinary catecholamine derivative levels, which can be obtained within a few hours.

[Angiosarcoma of the pericardium. Apropos of a case]

Malignant primary cardio-pericardial tumours are rare and difficult to diagnose because of the diversity of their clinical expression. The authors report a case of pericardial angiosarcoma and review the literature, underlining the value of new non-invasive imaging techniques in the diagnosis and surgical approach to obtaining histological confirmation. Magnetic resonance imaging is a valuable tool in this context as it allows scanning of the tumoral extension in all spatial planes and the visualisation of the haemorrhagic signs of malignancy the pericardial effusion related to this pathology.

[Value of the methylergometrin maleate test in recurrent cardio-circulatory arrests]

A 56-year-old man, with no particular past history, sustained two cardio-circulatory arrests preceded by constrictive chest pain. Coronary arteriography was normal during etiological investigations. The methylergometrine maleate (Méthergin (tm)) test enabled the diagnosis of severe spastic angina and guided appropriate management of this patient.

[Spontaneous coronary dissection. Apropos of 2 cases]

Spontaneous coronary dissection is a rare and still poorly understood pathological disease entity; the authors report two cases in which the diagnosis was reached in the context of incipient necrosis in young patients. A review of the literature reveals the main characteristics of this problem: the clinical aspect is generally that of acute coronary failure with the constitution of an infarction. The subjects are young with no risk factor but some cases of combination with a disease affecting the elastic tissue have been described. Female gender and the post-partum phase are promoting factors. Diagnosis was long established by means of autopsy but can now be based on coronary angiography. Histologically, the lesion is a hematoma which dissects the arterial wall between the internal two thirds and external third of the media. The main etiological hypothesis is acquired or congenital fragility of the media, which promotes the formation of a dissecting hematoma, however the triggering phenomenon remains poorly understood.

[Myocardial ischemia caused by the injection of dipyridamole followed by low level exertion on an exercise bicycle]

The purpose of this study was the feasibility, safety and analysis of the ischemic nature of the association of an injection of dipyridamole and an exercise test at low level exertion on an exercise bicycle for 4 minutes. The ischemic nature of this combination was assessed on the basis of three criteria: the onset of angina-type pain, electrical changes and scintigraphic abnormalities. The test could be carried out by all patients and the most common adverse events were headache (6.5%) and heartburn (3.5%). The 17 patients in this study who had one or more stenoses in excess of 70% presented with angina-type pain (3/17); electrical abnormalities (9/17) and scintigraphic abnormalities in all cases. Of the six patients who had lesions between 50 and 70%, 1 presented with angina symptoms, 2 with electrical abnormalities and 5 with scintigraphic abnormalities. Seven patients in this study showed no significant lesions when subjected to coronary artery angiography. However, angina-type pain and electrical signs were observed in 2 cases and one false positive result by scintigraphy. This study shows that it is possible to combine the injection of dipyridamole with an exercise test involving a low level of exertion on an exercise bicycle which gives a good diagnostic value to the CT scan. The frequency of clinical and electrical signs of ischemia makes it necessary to take the same precautions as for a peak exercise test.

Immunoblotting study of the antigenic relationships among eight serogroups of Leptospira

Seven strains of Leptospira interrogans belonging to seven different serogroups, and one strain of Leptospira biflexa were analysed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) with gradient gels and immunoblotting with hyperimmune rabbit sera raised against each strain. The molecular masses of the proteins were calculated with a polynomial regression model. The SDS-PAGE patterns of the L. interrogans strains were similar and characterized by 24 common bands. This profile was not found for L. biflexa. The immunoblots obtained either with the seven anti-L. interrogans sera or the anti-L. biflexa serum allowed a clear distinction between the two species. Taken as a whole, the L. interrogans strain patterns revealed by the seven anti-L. interrogans sera were similar, sharing eight common major bands. A serovar- or serogroup-specific antigenic zone, ranging from 21 to 26 kDa, was also identified.

[What are the indications for digitalis glycosides in the current treatment of cardiac insufficiency?]

Digitalis was discovered over two centuries ago and has been in everyday use for 100 years: however nowadays it is not considered to be the almost exclusive treatment of heart failure as it used to be with diuretic therapy. In the last decade, our understanding of the physiopathology of heart failure and the body's mechanisms of adaptation have improved and this has lead to the use of new molecules and a different approach to the problem of left ventricular failure. The classical contra-indications and precautions of use of digitalis have been studied in detail. The use of digitalis is contested especially in patients in sinus rhythm or with ischemic heart disease and it is used less often in adult cardiac emergencies. The competition between digitalis and vasodilator therapy is now very apparent in some situations; however, the choice between these two groups of drugs (as treatment of first intention or in association) has to be carefully considered in each individual case. The future of digitalis therapy lies without doubt in pediatric cardiology where it remains irreplaceable.

Vaccination of newborns of HBsAg-positive carrier mothers with a recombinant DNA hepatitis B vaccine

Thirty neonates born to HBsAg-positive mothers were vaccinated with a 20 microgram dose of the SmithKline Biologicals recombinant DNA yeast-derived vaccine within 24 hours after birth, with similar inoculations repeated 1 and 2 months later. Preliminary results indicate that the recombinant vaccine was well tolerated and immunogenic. A 100% seroconversion rate was achieved 4 months after the first vaccine dose and the anti-HBs geometric mean titres progressively rose from 14 to 31,279 and 361 IU/l at months 1, 2, 4, and 6, respectively. Although a longer period of observation and comparison with a historical control group are needed to evaluate its protective efficacy in this high-risk population, the fact that no vaccinated newborns have been infected is encouraging.

Effects of experimental gastroduodenal reflux on density of mast cells and plasmocytes in the fundic mucosa of the rat

IgA-, IgM-, IgG- and IgE-positive plasmocytes and mast cells were counted in the fundic mucosa of two groups of rats which underwent gastroenteroanastomosis or sham operation 12 months previously. Experimentally induced duodenogastric reflux constitutes a model for biliary gastritis which is characterized by a decrease in the IgA plasmocyte count along with an increase in IgG and IgE plasmocytes and, especially, an increase in mast cells. It is suggested that this allergic-type reaction is responsible for the hyperplasia of gastric crypts seen in biliary gastritis.

[Unruptured aneurysms of the sinus of Valsalva disclosed by syncopal disorders of cardiac excitability. Apropos of 2 cases]

Aneurysms of the sinus of Valsalva are rarely diagnosed before rupture into the cardiac cavities which usually leads to the appearance of a continuous murmur and cardiac failure. In the two cases described, the presenting symptom of the aneurysm was syncope due to cardiac hyperexcitability: ventricular tachycardia in the first and paroxysmal tachyarrhythmia in the second case. The presenting symptoms of unruptured aneurysms of the sinus of Valsalva were analysed. In general, they are: uncontinuous cardiac murmurs: either diastolic murmurs of aortic regurgitation, systolic murmurs of mitral or tricuspid regurgitation, or, as in our first case, of obstruction to right ventricular ejection; arrhythmias: the commonest are conduction defects, which can be syncopal; hyperexcitability (especially ventricular) seems to be very care. Echocardiography is a valuable tool for the diagnosis of sinus of Valsalva aneurysms. The appearances of unruptured aneurysms in our two patients are described. The presence of syncopal cardiac hyperexcitability, possibly associated with one of the preceding auscultatory abnormalities is an indication for echocardiography which may lead to the diagnosis of this condition.

[Pseudotumoral mitral endocarditis. Diagnostic and therapeutic problems apropos of a case report with review of the literature]

The authors report an observation of infectious endocarditis of the mitral valve with voluminous pseudo-tumoral growth. The developmental, symptomatic and etiological characteristics of this form of endocarditis were specified through a review of the literature. Echocardiography provides the best means of early detection of these large vegetations but it is not always easy to distinguish them from other left intra-auricular tumors, more especially as several cases of infectious myxoma have been described. Spontaneous development of mitral endocarditis is very harmful, as are infected left intra-auricular tumors, and surgical treatment of these disorders seems essential as soon as the infectious process has been arrested.

Dose-response study of RIT 4237 oral rotavirus vaccine in breast-fed and formula-fed infants

The RIT 4237 live attenuated bovine rotavirus vaccine was given orally at three dose levels to 75 breast-fed, 40 formula-fed and 24 fasting infants ages 4 to 6 months. Vaccine of 10(8.3) (50% tissue culture-infective doses) (TCID50) per dose gave a neutralizing antibody response in 14 of 14 (100%) formula-fed, in 18 of 26 (69%) breast-fed and in 5 of 8 (63%) fasting infants, or an overall response rate of 77% (37 of 48). The overall response rate to a vaccine of 10(7.2) TCID50 per dose was 61% (33 of 49), or slightly but not significantly lower than that at the higher dose level. On the other hand a vaccine of 10(6.3) TCID50 per dose gave a significantly (P less than 0.01) lower composite response rate of 33% (14 of 42). The overall serologic response rate to the vaccine at the two higher doses was somewhat better (24 of 28, 86%) in formula-fed infants than in breast-fed infants (37 of 52, 71%). However, the response rate of the breast-fed infants can also be considered satisfactory. Thus the current recommendation for use of the RIT 4237 vaccine would be administration of a dose of at least 10(8) TCID50 after feeding with either formula or breast milk.

Biological measurements of Crohn's disease activity--a reassessment

Fifty-eight patients with Crohn's disease were studied in order to compare disease activity as measured by a clinical scoring system, with nutritional status, the laboratory measurements reflecting nutritional status, and the serum levels of acute phase proteins, using principal component analysis and stepwise multiple regression analysis. We confirmed that orosomucoid is the laboratory measurement which correlates best with clinical assessment of disease activity, followed by ESR and C-reactive protein. Serum albumin correlated poorly with clinical disease activity, although body weight showed an inverse correlation. Serum fibronectin, a protein involved in the production of fibrous tissue, did not detect the presence of fibrous strictures in the intestine.

Immunisation of nurses with a live varicella vaccine

34 nurses who had no previous history of chickenpox and were seronegative to varicella zoster virus (VZV) were immunised with a live attenuated varicella vaccine (OKA-RIT strain) and followed up for up to 36 months. No major vaccine reactions were observed. At 5 months and at 1 year, 94% of the nurses had seroconverted but at 3 years only 64% had detectable antibody. Lymphocyte transformation to VZV antigen tested in seven nurses in whom antibody was no longer detectable gave positive stimulation indices. 2 of 13 vaccinated nurses who looked after children with chickenpox became infected but 1 of them had not seroconverted after vaccination. Chickenpox developed in 6 out of 7 unvaccinated seronegative nurses who looked after children with chickenpox. This study shows that the OKA-RIT strain VZV vaccine is safe and immunogenic in adults and may therefore be considered for use in susceptible health care workers. The investigations also show that both cell-mediated and antibody tests are needed for long-term assessment of immunity to chickenpox after vaccination.

Role of histamine in the cell turnover changes associated with experimental gastric ulceration in the mastomys

Using an animal model of gastric ulceration, in vivo and in vitro methods were developed to assess the importance of histamine in the cell turnover abnormalities previously found to occur in the preulcerous phase of gastric ulceration induced by mucosal anaphylaxis, and by using specific H1- and H2-receptor agonists and antagonists to define which receptors were involved. In ovalbumin-immunized animals, intramucosal ovalbumin injection led to a highly significant increase in cell turnover as measured by [3H]thymidine uptake (p less than 0.001). This increase was not affected by treatment with the H2 antagonist cimetidine, but was significantly reduced by the H1 antagonists promethazine and clemastine (p less than 0.01). A cell culture method was then used to examine the effects of added histamine and its antagonists. Histamine at a concentration of 10(-7) M was found to have a significant stimulatory effect on cell proliferation (p less than 0.001), and this effect was blocked by promethazine and clemastine but not by cimetidine. In contrast, histamine at a concentration of 10(-2) M had an inhibitory effect on cell proliferation which was accentuated by cimetidine and partially reversed by promethazine and clemastine. The H1 agonist betahistine was found to have stimulatory effects similar to those of histamine in low concentration (10(-7) M and 10(-6) M), but the H2 agonist 4-methyl histamine did not affect thymidine uptake at these concentrations. Both H1 and H2 agonists had a similar inhibitory effect at a concentration of 10(-2) M. It is concluded that histamine probably plays an important part in the changes in cell kinetics associated with gastric ulceration induced by this method, and that the trophic effects of histamine are mediated by H1-receptors. H2-receptors appear to have only a limited role in the control of cell proliferation.

Animal models for hormone-dependent human breast cancer. Relationship between steroid receptor profiles in canine and feline mammary tumors and survival rate

The present study shows that canine and feline mammary tumors, like human breast tumors, can be polyreceptive, i.e., they can contain estrogen (ER), progestin (PR), androgen, glucocorticoid, and/or mineralocorticoid cytosol receptors. Furthermore, a follow-up of 45 bitches with mammary carcinoma has indicated that the survival rate is significantly higher in animals with receptor-rich (ER and/or PR) tumors. This indicates that these canine mammary tumors should be evaluated further for their suitability as an animal model for hormone-dependent human breast carcinoma.

Pesticide-containing diets augment anti-sheep red blood cell nonreaginic antibody responses in mice but may prolong murine infection with Giardia muris

The effects of oral ingestion of different pesticides (lindane, phosalone, carbaryl) and of a polychlorinated biphenyl (pyralene) on nonreaginic antibody production in BALB/c mice and also on the duration of Giardia muris infection have been studied using the animal model of this disease. Only lindane and carbaryl produced significant effects on systemic antibody production following oral immunization with sheep red blood cells (SRBC). Lindane ingestion led to a twofold increase in IgG2b antibody titer to SRBC (P less than 0.05) and carbaryl significantly increased both IgG1 and IgG2b titers. No reduction was seen in the synthesis of any antibody class. The effect of feeding with lindane was to increase the duration of giardiasis significantly (P less than 0.002), and these mice developed systemic anti-Giardia antibodies more frequently than Giardia-infected mice on normal diets. These results suggest that in the doses used these pesticides may increase systemic antibody responses to orally ingested antigens, and by inference that spontaneous elimination of giardiasis is independent of the systemic nonreaginic antibody response to the parasite.

Assessment of appropriate laboratory measurements to reflect the degree of activity of ulcerative colitis

Eleven laboratory parameters were compared with the clinical grading of disease activity in 44 patients with ulcerative colitis, using multiple stepwise regression analysis to identify which measurements significantly reflect the severity of the disease. Only 2 parameters, serum orosomucoid and haematocrit showed significant correlation with clinical status. It is suggested that in the method of assessing disease activity proposed by Truelove and Witts the haemoglobin, which in this study was found to have no value, could be replaced by an equally simple test, the haematocrit. Comparisons are made between the relative usefulness of these parameters in ulcerative colitis and Crohn's disease.

Role of mast cell mediators in pathogenesis of anaphylactic gastric ulcer

In an attempt to elucidate the pathophysiological mechanisms of gastric anaphylactic ulcer we measured tritiated thymidine incorporation in gastric cells, their mitotic rate and the degranulation of mast cells in the preulcerous phase. The results showed that there is a highly significant increase in cell turnover and mast cell degranulation in the mucosa of sensitized animals. Changes were found at the site of ovalbumin challenge, where point ulceration occurred within 48-72 h. The tissue culture studies demonstrated that the mucosa of sensitized animals produces significantly more histamine when challenged with ovalbumin than the mucosa of nonsensitized animals. Addition of histamine to the tissue culture medium in which normal gastric mucosa was cultured led to an increase in [3H]-thymidine uptake at low concentration, and a decrease at high concentration. Serotonin added to the culture medium had no significant effect on [3H]-thymidine uptake, but heparin at high concentration was found to have a stimulatory effect. These studies show that anaphylactic gastric ulceration is associated with an increase in mucosal cell turnover, and that the mast cell mediator responsible for this increase may be histamine.

Abrogation by subsequent feeding of antibody response including IgE, in parenterally immunized mice

We have investigated the possibility of oral administration of ovalbumin (OVA) to prevent a secondary antibody response and interrupt reaginic antibody production. Repeated feeding seems necessary for both. Quality of results was dependent on the number of ingestions. Differences in abrogation of antibody response between mice strains were observed. Best results were obtained with AKR mice, good suppression was seen in C3H strain, and inconsistent results were obtained with DBA/2. 10 OVA oral doses were necessary to prevent a secondary antibody response in parenterally immunized mice, but 4 doses interrupted reaginic production in sensitized AKR mice. These results demonstrate that antigen feeding can prevent a secondary antibody response and interrupt reaginic antibody production.