Characterization of five monoclonal antibodies specific for swine class II major histocompatibility antigens and crossreactivity studies with leukocytes of domestic animals

A set of five monoclonal antibodies (mAb) against porcine major histocompatibility complex (MHC), or swine leukocyte antigens (SLA), class II molecules has been characterized. These mAbs appear to recognize monomorphic determinants on SLA-DR (2F4, 1F12 and 2E9/13) and SLA-DQ (BL2H5 and BL4H2) molecules, as assessed by flow cytometry and immunoprecipitation. By Western blot, the 2F4, 1F12, BL2H5 and BL4H2 epitopes were located on the beta-chains of these molecules. mAbs 2F4 and 1F12 crossreact with leucocytes of dog, cattle, horse and human; mAbs 2E9/13, BL2H5 and BL4H2 bind leucocytes of cattle but not those of human, dog and horse. These mAbs effectively blocked the mixed lymphocyte reaction and the proliferative response to viral antigens (African swine fever virus) and to staphylococcal enterotoxin B. Therefore, these mAbs can be useful reagents for studying MHC class II molecules of pig and crossreactive species, and the immunological processes where they are involved.

Monoclonal antibodies specific for porcine monocytes/macrophages: macrophage heterogeneity in the pig evidenced by the expression of surface antigens

Macrophages are widely distributed in most tissues of the body, where they play important roles in host defense and repair of tissue damage. In this report we describe the production and characterization of a panel of six monoclonal antibodies (mAb) against porcine macrophages and their use for phenotyping tissue macrophages. All mAbs were produced by immunizing mice with porcine alveolar macrophages. Three of them (2A10/11, 3B11/11 and 3F7/11) react mainly with macrophages and, at a lower extent, blood monocytes, whereas the others (1E12/11, 2C12/10 and 4E9/11) also recognize granulocytes. Antigens recognized by these antibodies could be characterized by Western blot and/or immunoprecipitation, with the exception of that one recognized by 2C12/10. By their behavior in SDS-PAGE under reducing and nonreducing conditions, all seem to be single polypeptides, whose apparent molecular weight under reducing conditions are: 1E12/11 and 3B11/11 larger than 204 kDa; 2A10/11, 150 kDa; 4E9/11, 125-170 kDa; and 3F7/11, 135 kDa. Immunohistochemical analyses of both lymphoid and non-lymphoid organs using these mAbs reveal important antigenic heterogeneity among tissue macrophages. These mAbs are, therefore, useful tools for the study of porcine macrophage maturation and differentiation and for determining their heterogeneity both in normal and pathological conditions.

Diagnostic and therapeutic thoracoscopy in esophageal cancer

The decision before operation whether an esophagus affected by cancer can be resected is difficult. In order to determine if the tumor can be removed or not, patients must undergo surgery. This high risk intervention is often carried out only to prescribe palliative treatment. We used a thoracoscopic technique for the diagnosis and resection of esophageal cancer with the aim of improving the high morbidity rate associated with esophageal open surgery. A right thoracoscopy was performed in seven patients and only four underwent resection. The entire esophagus was mobilized thoracoscopically and the intervention was completed through the abdomen and the neck. In three patients in whom resection was not considered possible, the thoracoscopic procedure was done with excellent tolerance, and treated by palliative methods. Thoracoscopy is a very valuable procedure for the diagnosis of resectability as well as for the mobilization of the esophagus prior to resection.

Direct detection of Mycobacterium tuberculosis complex in nonrespiratory specimens by Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test

The Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test (AMTDT) was adapted for the detection of Mycobacterium tuberculosis complex in 224 nonrespiratory specimens from 188 patients. The sensitivity and specificity of the AMTDT for such specimens, after resolution of discrepant results, were 85.7 and 100%, respectively. Pretreatment of nonrespiratory specimens with sodium dodecyl (lauryl) sulfate is mandatory to obtain consistent and reproducible AMTDT results. The use of 500 microliters of decontaminated specimen improves the sensitivity of the test. Because the AMTDT detects stable rRNA from noncultivable bacilli, it is not useful for monitoring patients receiving treatment.

Synthesis of pyridopyrimidone derivatives and their activity against P. falciparum in vitro

Pyridopyrimidone derivatives 4a-d and 5a- were synthesized as potential antimalarial agents on the basis of the pharmacological properties of existing quinolone analogues such as ciprofloxacine IC50 39.8 microM. Meanwhile among these new compounds, only the 3-amino-7-methyl-1(H)pyrazolo[3,4-b]-pyrido [1,2: 1'2']pyrimido-4-ona 4b, produces significant antimalarial activity IC50 0.42 microM against P. falciparum in vitro. The remaining compounds were effective as antimalarial agents leading from IC50 1.0 microM to IC50 4.47 microM.

Evaluation of the disinfectant effect of Solprogel against human immunodeficiency virus type 1 (HIV-1)

The antiviral activities of sodium dichloroisocyanurate (NaDCC) and a commercial product (Solprogel 2%) against human immunodeficiency virus type 1 (HIV-1) were investigated using a quantitative suspension test method. Solprogel is a compound that contains NaDCC and a biodegradable polymer of acrylic acid. Viral suspensions were prepared containing 3.2 x 10(6) tissue culture infective dose 50 (TCID50) in culture media. Syncytium formation in the MT-2 line and HIV antigen p24 on the supernatant of the cultures were used to determine viral titre. Results indicate that satisfactory disinfection (1000-fold reduction in 5 min) can be achieved using NaDCC and Solprogel at concentrations of 100 and 120 ppm available chlorine, respectively.

The role of the nodI and nodJ genes in the transport of Nod metabolites in Rhizobium etli

A kinetic analysis of secretion of lipo-chitin oligosaccharides (LCO) produced by Rhizobium etli (Re) wild-type (wt) strain and derivatives carrying disrupted nodI or nodJ genes was performed. LCO were detected in the growth media of the wt strain as early as 1 h after nod gene induction. In contrast, strains carrying nodI or nodJ mutations secreted less LCO, and accumulated LCO metabolites intracellularly after 4 h of induction. These Re mutants presented a delayed nodulation phenotype and a reduction in the maximum number of nodules formed in Phaseolus vulgaris roots.

Monoclonal antibody 2F4/11 recognizes the alpha chain of a porcine beta 2 integrin involved in adhesion and complement mediated phagocytosis

The characterization of a new mAb, named 2F4/11, specific for porcine myelomonocytic cells is described. This mAb immunoprecipitates a non-covalently linked heterodimer of 155,000/95,000, which is expressed by granulocytes, monocytes and tissue macrophages but not by lymphocytes, erythrocytes or platelets. Immunoblot analysis localizes the 2F4/11 epitope on the largest subunit of the heterodimer. Mab 2F4/11 is able to block phagocytosis of complement-opsonized zymosan particles by PMN granulocytes and alveolar macrophages, as well as adherence to plastic surfaces of PMA-activated PMN. Together, these results suggest that mAb 2F4/11 recognizes the CD11b or alpha chain of the porcine complement type 3 receptor (CR3).

[Subdural hematoma associated with arachnoid cyst]

We describe 3 young patients with history of mild cranial trauma who presented the rare association of subdural hematoma and arachnoid cyst. Clinical and radiological signs are reviewed.

Irreversible tetraplegia after tracheal resection

The case of a 21-year-old woman without previous cervical pathology in whom irreversible tetraplegia developed after operation for tracheal stenosis is reported. After tracheal resection the neck was kept in extreme flexion and after extubation she was moved to a sitting position. The different causal agents that could produce the neurologic damage remain unclear, although we think that the combination of relative arterial hypotension secondary to the sitting position and disturbed autorregulation, caused by extreme neck flexion, could result in ischemic spinal cord injury.

[The degree of compliance with the radiology requests from primary care]

OBJECTIVE

To study the level of compliance with the radiological tests requested from primary care.

DESIGN

A crossover, descriptive study with systematic randomised distribution.

SETTING

Catchment area of a specialist centre covering eight urban health districts in Zaragoza.

MATERIAL

413 X-ray requests out of those requested between January and March, 1995.

MEASUREMENTS AND RESULTS

The filling in of the following sections was evaluated: patient's basic data, referral from, clinical/investigatory data, suspected diagnosis and its agreement with the radiology report, the investigation requested, date, signature and legibility of the request. Compliance was: complete name, 100%; telephone, 37%; address, 50%; social security number, 99%; referral from, 71%; symptomatology, 92%; clinical investigation, 35%; suspected diagnosis, 56%; date, 92%; signature, 86%; good legibility in 13% of cases and poor in 75%. Distribution by gender: men 44%, women 56%, a significant difference. Average age 47.2, women 49.9 and men 43.8, also a significant difference. Simple osteoarticular x-ray was the commonest request (43.3%).

CONCLUSIONS

1) There was poor compliance in the telephone and address sections. 2) Clinical data (symptoms, investigations) and the suspected diagnosis were also insufficient. 3) Date and signature did not reach the desirable 100% compliance. 4) Deficient legibility, with very few requests not causing problems.

Synthesis and activity of some quinolone derivatives against Plasmodium falciparum in vitro

Quinolones 7a-i and 8a-i were synthesized and tested in vitro as antimalarial against Plasmodium falciparum in chloroquine resistant strain. The above compounds were inactive at concentrations of 1.0 x 10(-4) M except the quinolone 3-amino-9-(2,4-dichlorophenyl)-1H-pyrazolo[3,4-b]-4-quinolone 7h which showed IC50 of 5.06 microM given the most interesting results.

Brain oedema in patients with intracranial meningioma. Correlation between clinical, radiological, and histological factors and the presence and intensity of oedema

The authors analysed the correlation between different clinical, radiological, and pathological variables and the presence and intensity of brain oedema associated to intracranial meningioma in 400 consecutive patients studied by computerized tomography (CT). The following factors did not show significant correlation with brain oedema development: the age and sex of the patient, the occurrence of focal deficits, the presence of skull changes (endostosis, exostosis, osteolysis), the occurrence of tumour calcification, the density of the tumour on plain CT scan, the presence of a cystic component, the pathological subtype of meningioma (both conventional and non-conventional), and the presence of histological features of tumour aggressiveness, such as an increased vascularization, high cellularity, high mitotic index, pleomorphism, necrosis, and brain infiltration. Factors showing a statistically significant correlation with the presence and intensity of brain oedema at the bivariate analysis were: the presence of symptoms (p < 0.001), the duration of the clinical history (p < 0.05), the location and size of the tumour (p < 0.001), the type (heterogeneous vs homogeneous), and intensity of tumour contrast enhancement (p < 0.001), the presence of irregular tumour margins (p < 0.001), and the existence of focal low density intratumoural areas (p < 0.001). The multivariate analysis using only clinical parameters showed that the group of variables with the highest power for predicting the presence of brain oedema (concordance level of 76.8%) included: the presence of symptoms, the occurrence of seizures (focal or generalized), the presence of an intracranial hypertension syndrome, and the age of the patient. The multivariate analysis using only anatomico-radiological parameters showed that the model which included the size of the tumour, the intensity of contrast enhancement, the tumour margins, and meningioma location, predicted the presence of brain oedema in 80.8% of the cases. Though the results of the present study do not definitively support any of the major physiopathological theories proposed to explain brain oedema formation in patients with intracranial meningioma, some findings could favour the so-called hydrodynamic theory.

Isolation, chemical structures and biological activity of the lipo-chitin oligosaccharide nodulation signals from Rhizobium etli

Rhizobium etli is a microsymbiont of plants of the genus Phaseolus. Using mass spectrometry we have identified the lipo-chitin oligosaccharides (LCOs) that are produced by R. etli strain CE3. They are N-acetylglucosamine pentasaccharides of which the non-reducing residue is N-methylated and N-acylated with cis-vaccenic acid (C18:1) or stearic acid (C18:0) and carries a carbamoyl group at C4. The reducing residue is substituted at the C6 position with O-acetylfucose. Analysis of their biological activity on the host plant Phaseolus vulgaris shows that these LCOs can elicit the formation of nodule primordia which develop to the stage where vascular bundles are formed. The formation of complete nodule structures, including an organized vascular tissue, is never observed. Considering the very close resemblance of the R. etli LCO structures to those of R. loti (I. M. López-Lara, J. D. J. van den Berg, J. E. Thomas Oates, J. Glushka, B. J. J. Lugtenberg, H. P. Spaink, Mol Microbiol 15: 627-638, 1995) we tested the ability of R. etli strains to nodulate various Lotus species and of R. loti to nodulate P. vulgaris. The results show that R. etli is indeed able to nodulate Lotus plants. However, several Lotus species are only nodulated when an additional flavonoid independent transcription activator (FITA) nodD gene is provided. Phaseolus plants can also be nodulated by R. loti bacteria, but only when the bacteria contain a FITA nodD gene. Apparently, the type of nod gene inducers secreted by the plants is the major basis for the separation of Phaseolus and Lotus into different cross inoculation groups.

[Neoplastic obstructive jaundice: palliative treatment with self-expandable metallic prosthesis]

PURPOSE

Study of the effectiveness and morbidity of palliative treatment of malignant obstructive jaundice with metallic biliary endoprosthesis compared to surgical palliation.

DESIGN

Retrospective review.

PATIENTS

35 patients with non-resectable neoplasms causing jaundice were treated with percutaneous stent (pancreatic carcinoma, n = 11; cholangiocarcinoma, n = 11; gallbladder carcinoma, n = 4; extrahepatic metastases of various malignancies, n = 8).

CONTROL GROUP

23 patients with malignant jaundice treated with palliative surgery.

RESULTS

Most frequent complications were cholangitis and stent obstruction. The mean hospital stay after the stent placement was 6.8 days, longer in patients with complications (p = 0.035). Recurrence of jaundice was seen in 22.9% of the patients and the rate of readmission was 42.9%. The mean survival was 163.33 days (range 19-522). Reduction in serum bilirubin after BE was significant (215 vs. 82 mmol/l, p < 0.001).

CONCLUSIONS

Comparing to our previous experience with surgical palliative treatment, there was no significant difference neither in morbidity-mortality, nor recurrence or readmission. Patients with pancreatic cancer and cholangiocarcinoma benefit from a shorter hospital stay.

Treatment of hemobilia with selective hepatic artery embolization

PURPOSE

To evaluate retrospectively the results of selective transcatheter embolization in the treatment of hemobilia.

PATIENTS AND METHODS

Twelve patients with hemobilia (mean age, 43 years) underwent embolotherapy. Causes of hepatic vascular injury were iatrogenic trauma, blunt external trauma, septic emboli, and lupus vasculitis. A 5-F cobra catheter or a 5-F non-tapered Simmons shaped catheter passed over a hydrophilic guide wire, or a Tracker 18 catheter forming a coaxial system was used. Embolic agents included gelatin sponge or polyvinyl alcohol fragments used alone or with coils.

RESULTS

Hepatic artery pseudoaneurysms were found in 10 patients, ruptured hepatic artery aneurysm was found in one, and arterioportal fistula was found in two (with pseudoaneurysm in one). Bleeding was immediately controlled in 11 of 12 patients after embolization; one patient rebled and underwent surgery. Two patients underwent repeat embolization (2 weeks and 2 months later). Two patients died, one of biliary sepsis and liver insufficiency 24 hours after embolization and the other of gangrenous cholecystitis.

CONCLUSION

Transcatheter embolization is an effective treatment of hemobilia. It allows control of bleeding and identification of the origin of the hemorrhage.

Interaction between noradrenergic and histamine-containing neurons in the rat vas deferens

A decussation of histamine (HA)-containing nervous pathways, at the level of the sympathetic ganglionic clusters of the rat vas deferens, was formerly described in this laboratory. This type of neuronal distribution is confirmed in the present study by using surgical interruptions of nervous pathways and determining changes in L-histidine decarboxylase (HD) activity, as an HA-containing neuron marker, after nerve degeneration. Decreases of HD activity follow previously found decreases of HA levels in the vas deferens submitted to the same type of surgical interruptions. An interaction between noradrenergic neurons and HA-containing neurons is suggested, because electrical stimulation of the preganglionic sympathetic nerve causes a rapid increase in HD activity in the ipsilateral vas deferens, possibly as a signal of the activation of HA-containing neurons, whose pathways come from the opposite ganglion. This activation appears to be indirect, presumably through a sensory interneuron, which upon being excited by the enhanced sympathetic discharge crosses over to stimulate the contralateral ganglionic HA-containing neuron. The sympathetic discharge-induced peripheral loop reflex resulting in an increase in HD activity depends upon the integrity of the noradrenergic neuron. An, as yet unknown, interaction seems to occur between the noradrenergic neurons and the HA-containing neurons in the rat vas deferens, when the sympathetic activity of the latter is enhanced.

Two different subpopulations of Ig-bearing cells in lymphoid organs of rainbow trout

In a previous report we described the existence of two structural and antigenic variants of light chains in serum trout Igs, defined by mAbs 2H9 and 2A1. In this report, we analyse the cell distribution, the "in vitro" kinetics of production, and the ontogenic appearance of these two variants. Both variants were already present at day 8 before hatching and their kinetics of appearance correlated with that of total Ig, showing a peak around hatching. These mAbs stained two distinct lymphoid cell populations in the pronephros, mesonephros, spleen, and peripheral blood. Both mAbs reacted with approximately 1% of thymocytes. The ratio between these two cell populations (2A1+/2H9+) was about 2/1 in the lymphoid organs analysed. No differences were found between the profiles of the "in vitro" production of these variants in pronephric cell cultures stimulated with LPS. In these cultures, the 2A1 and 2H9 Igs together accounted for 10-70% of the total trout Ig produced, suggesting the existence of at least one additional L chain variant.

[Microbiologic diagnosis of typhoid fever: report on an outbreak]

BACKGROUND

The incidence of typhoid fever has greatly fallen in Spain although sporadic cases and limited outbreaks may be observed. The usefulness of the serum agglutinin studies for the diagnosis of this disease has been questioned by many authors. However, this diagnosis criteria continues to be used in Spain. The usefulness of blood cultures, stool cultures, urinecultures and serological test is herewith compared.

METHODS

Three groups were prospectively studied: 18 patients with typhoid fever from one single outbreak, 50 blood donors, and 24 patients with other infections. Blood, stool culture, urinecultures and serology (agglutination) were carried out in the first group and in the other two groups serological test were used to determine the cut-off points and study cross reactions.

RESULTS

Blood culture was found to be the most sensitive technique (94%) followed by stool culture (53%). No positive urineculture of seroconvesrion were observed. The cut off points accepted following the study of the donors were 1/160 or greater for the O antigen and 1/320 or greater for the H antigen. Two false positive for the O antigen and 3 for the H antigen were observed in the 24 patients with other infections.

CONCLUSIONS

When suspecting typhoid fever, the combined use of blood culture and stool culture is recommended. The usefulness of serological test in our area lays in the observation of seroconversion associated to a compatible clinical picture. Its performance should not being considered as adequate in unspecific febrile syndromes.