One-step purification of the major rainbow trout immunoglobulin

Salmonid immunoglobulin purification has been hampered by time-consuming, labour-intensive, conventional chromatographic procedures. In this report we describe the use of immunoaffinity chromatography for the purification of immunoglobulins from trout serum in a single step. An anti-heavy chain monoclonal antibody (1G7) which reacts with more than 85% of total trout immunoglobulins was used to purify the trout immunoglobulin. The purity achieved was higher than 95%, and the immunoglobulins recovered were fully immunogenic. This method served equally well in isolating immunoglobulins from the sera of other salmonids (coho salmon and chinook salmon). The procedure should be useful in the standardization of salmonid immunoglobulin reagents.

Rapid serotyping of infectious pancreatic necrosis virus by one-step enzyme-linked immunosorbent assay using monoclonal antibodies

A one-step ELISA has been developed for detection and serotyping of infectious pancreatic necrosis virus (IPNV) in infected cell cultures using monoclonal antibodies (mAb) raised against strains representing the Sp, Ab and VR 299 serotypes of IPNV. This assay uses a serotype-specific mAb as capture and a mAb directed against a common epitope as detector antibody. Avidin-peroxidase was employed for amplification. The assay was performed in 90 min by simultaneous incubation of the samples, the biotin labelled mAb and the avidin-peroxidase, and detected 37 ng/ml of purified virus. Serotyping of 34 isolates from different areas of Europe, Asia and America showed a total concordance with the results obtained by the neutralization assay.

Naloxone potentiation of cardiovascular responses to sympathomimetic amines in the rat

The work was aimed at analyzing the ability of naloxone to potentiate 1) the arterial pressure responses to sympathomimetic amines administered i.v. in normotensive anesthetized, pithed, chemically sympathectomized or acutely adrenalectomized rats and 2) the chronotropic responses to norepinephrine in the isolated rat atria. In anesthetized rats, naloxone (2.5-10 mg/kg i.v.) potentiated the pressor responses to epinephrine (2 micrograms/kg). Naloxone (5 mg/kg) significantly potentiated the pressor responses to norepinephrine (1-4 micrograms/kg), phenylephrine (10-50 micrograms/kg) and the reflex pressor responses to a 60-sec carotid occlusion. On the contrary, naloxone did not potentiate the arterial pressure responses to methoxamine (100 micrograms/kg), angiotensin (0.5-2 micrograms/kg) and isoproterenol (1 micrograms/kg). Pithing or acute adrenalectomy did not alter the naloxone-induced potentiation of the pressor responses to norepinephrine (0.125-0.5 micrograms/kg). 6-Hydroxydopamine pretreatment abolished completely the naloxone-induced potentiation of the pressor responses to norepinephrine (0.25-1 micrograms/kg). In isolated rat atria, naloxone (1.4 and 2.8 x 10(-5) M) potentiated the chronotropic responses to norepinephrine (1.5-6 x 10(-8) M). It is suggested that naloxone potentiates cardiovascular responses to sympathomimetic amines by interacting with presynaptic adrenergic mechanisms which could additionally contribute to its pressor effects in acute hypotensive conditions.

Evaluation of an enzyme-linked immunosorbent assay to detect specific antibodies in pigs infested with the tick Ornithodoros erraticus (Argasidae)

Ornithodoros erraticus is known to transmit the virus that causes the highly contagious disease, African Swine Fever, in Spain. As part of the disease eradication campaign, an ELISA test to detect specific antibodies against the tick was developed. The ELISA, using salivary gland preparations as an antigen, showed high sensitivity and was able to detect as few as 10 adult ticks. The specific antibodies were detected in the sera 6 weeks after the primary infestation and strongly increased after the challenge. The utility of this test under field conditions was also tested.

Common antigenic determinants of the tubulin binding domains of the microtubule-associated proteins MAP-2 and tau

The structural-functional aspects of the tubulin binding domain on the microtubule-associated protein MAP-2, and its relationship with the tubulin binding domain on tau, were studied using anti-idiotypic antibodies that react specifically with the epitope(s) on MAPs involved in their interaction with tubulin in addition to other tau and MAP-2 specific antibodies. Previous studies showed that MAP-2 and tau share common binding sites on tubulin defined by the peptide sequences alpha (430-441) and beta (422-434) of tubulin subunits. Furthermore, binding experiments revealed the existence of multiple sites for the interaction of the alpha- and beta-tubulin peptides with MAP-2 and tau. Most recent studies showed that the synthetic tau peptide Val187-Gly204 (VRSKIGSTENLKHQPGGG) from the repetitive sequence on tau defines a tubulin binding site on tau. Our present immunological studies using anti-idiotypic antibodies which interact with the synthetic tau peptide and antibodies against the Val187-Gly204 tau peptide indicate that MAP-2 and tau share common antigenic determinants at the level of their respective tubulin binding domains. These antigenic determinants appear to be present in the 35 kDa tubulin binding fragment of MAP-2 and in 18-20 kDa chymotryptic fragments containing the tubulin binding site(s) on MAP-2. These findings, along with structural information on these proteins, provide strong evidence in favor of the hypothesis that tubulin binding domains on MAP-2 and tau share similar structural features.

Purification and characterization of an allergen of mustard seed

A protein allergen has been isolated from mustard seed extracts by gel filtration. In RAST-inhibition experiments the allergen inhibited more than 60% of the binding of mustard-specific IgE from a pool of seven patients' sera. The allergenic activity was also demonstrated by histamine release from whole blood from two sensitive patients. The allergen had an isoelectric point close to 10.5 and an apparent molecular weight of 14,000. It was stable in alkaline and acid solutions and showed resistance to heating and to degradation by proteolytic enzymes.

Epitope mapping of the major allergen from yellow mustard seeds, Sin a I

The antigenic sites on the major allergen from yellow mustard (Sinapis alba L.) seeds were studied using murine (BALB/c) monoclonal antibodies (mAb) and human IgE antibodies. Ten IgG1 (K) mAb from two fusions were analyzed. Competition and complementation studies performed with peroxidase labeled mAb reveal the existence of two main antigenic sites in Sin a I. All the described mAb failed to recognize the unordered carboxyamidomethylated polypeptide chains, with the single exception of 2B3, which binds the alkylated large chain. However, this mAB cannot react with the tetranitromethane-modified protein which retains the native conformation. This fact suggests that the only tyrosine of Sin a I, located in the large chain, may be part of a sequential epitope of the allergen. This chemical modification also alters the binding of the mAb 4A11 and 3F3 to the allergen, besides 2B3. The three mAb belong to the same complementation group. Specific IgE binding cannot be inhibited either by the large or small carboxyamidomethylated polypeptide chains, while the nitrated allergen shows a weaker inhibitory activity than the native Sin a I. 4A11, which is a tyrosine-dependent mAb, causes the greatest binding inhibition of the tested mAb on human IgE from atopic individuals, as determined from a reverse enzyme immunoassay, suggesting an important role played by tyrosine in the immunochemical recognition of Sin a I.

Primary structure of the major allergen of yellow mustard (Sinapis alba L.) seed, Sin a I

Sin a I, a 2-S albumin from the seeds of yellow mustard, is herein described as the major allergen of these seeds. This protein is composed of two disulfide-linked polypeptide chains of 39 and 88 amino acids, whose primary structures are reported. The Sin a I allergen is found to be related to other low-molecular-mass albumins, such as those isolated from rapeseed, castor bean and Brazil nut. Additional structural similarity has also been found between the glutamine-rich large chain of Sin a I and a proline-rich zein, a gliadin, and trypsin and alpha-amylase inhibitors isolated from the seeds of several monocotyledons. Internal amino acid sequence similarity has been detected at both termini of the small and large chains of Sin a I and involves the location of proline and glycine residues at similar positions in relation to the processing cleavage sites. Prediction of secondary structure, based on the amino acid sequences of the mature chains of the mustard allergen, indicates that the precursor polypeptide is cleaved at regions showing a high beta-turn probability. This is also observed with the amino acid sequence deduced from the rapeseed napin gene nucleotide sequence.

Entamoeba histolytica: cell cycle and nuclear division

The cell cycle of Entamoeba histolytica, the duration of its phases, and the details of the nuclear division stages are described in this paper. Trophozoites from clone L-6, strain HM1:IMSS, were synchronized by colchicine. Synchrony was observed immediately after treatment and cultures remained synchronous for at least three replicative cycles with synchrony indexes between 13 and 15 hr. The stages of nuclear division were studied by light and electron microscopy. Four stages of the nuclear division were defined: prophase, early anaphase, late anaphase, and telophase. No metaphase stage was observed by light or electron microscopy. One of the first events in the nuclear division was the presence of a bud close to the juxtanuclear body, which grew to a daughter nucleus. The karyosome and the nuclear membrane remained throughout the mitotic process. Bundles of intranuclear microtubules were observed forming a "V" from the center of the nucleus to one of the poles, and associated with them, 12 to 16 chromosomes-like structures appeared. The results of these studies strongly suggest that division of E. histolytica involved a pleuromitotic process which is carried out in about 120 min.

Double labeling immunohistological study of African swine fever virus-infected spleen and lymph nodes

To identify cells in situ in which African swine fever (ASF) virus is present, a double immunohistological labeling technique was used on sections of ASF-infected spleen and lymph nodes. Cells were identified by an indirect immunoalkaline phosphatase technique using monoclonal antibodies (MoAb) reactive against different leukocyte subsets. ASF virus, detected by a direct immunoperoxidase method using swine immunoglobulin G (IgG) anti-ASF virus antigens, was not present in T helper or in T cytotoxic/suppressor lymphocytes, whereas it was detected in tissue macrophages that reacted with different MoAb (74-22-15, C4, A7, and F2). A large number of cells strongly reactive with MoAb 74-12-4 (T helper lymphocytes) were found in the marginal zone in infected spleen. In infected lymph nodes, these intensely stained cells were found in small numbers. Cells reactive with MoAb 76-2-11 (T cytotoxic/suppressor lymphocytes) were less stained in infected spleen and lymph nodes than in non-infected organs.

EGG hypersensitivity as measured by RAST and a reverse enzyme-immunoassay

The application of a reverse enzyme-immunoassay (REIA) to measure specific anti-egg IgE is described. The results obtained with the REIA and the RAST are shown. The REIA is economical, easy and fast to perform when the conjugate has been made, non-radioactive and offers a new alternative for the in vitro evaluation of egg white-specific IgE.

[Rokitansky-Kuster-Hauser-Mayer syndrome. Psychological aspects in current technics in the creation of a neovagina apropos of 2 cases]

A review is made of the actual status of the Rokitansky-Hauser-Kuster-Mayer Syndrome in the following aspects: clinic, diagnostic and actual techniques in the construction of a neovagina. An special remark is made on the importance of the psychologyc and psychosocial aspects in the management, diagnostic and treatment of this patients. Two cases are presented.

Developmental changes in the folate-dependent enzymes of de novo purine biosynthesis in rat brain

The activities of the two folate-dependent enzymes in the de novo purine biosynthetic pathway (e.g., glycinamide ribonucleotide transformylase and aminoimidazolecarboxamide ribonucleotide transformylase), have been evaluated as a function of age in crude extracts from rat brain, liver, kidney, and spleen. The activities of the enzymes in brain are similar to those found in liver and kidney. In all tissues the activity of both enzymes was higher during early development, more than nine times above adult levels. In the CNS the enzymatic activities are apparently related to the periods of increased nucleic acid synthesis, with different activities being found in different regions during development. Our findings lend strong support to the suggestion that folic acid-dependent metabolism plays an important role during early development of the brain.

[Circulating immune complexes in the serum of tumor patients]

The conditions for the detection of circulating immune complexes (CIC) were established by combination of polyethylene glycol precipitation with a nephelometric determination on the precipitate of endogenous C1q. The CIC precipitated from the sera of patients with breast carcinoma, malignant melanoma or autoimmune diseases were dissociated in SDS-beta-mercaptoethanol buffer and no differences were observed in the electrophoretic patterns os polyacrylamide gels allowing to characterize tumour specific antigens.

[Hemihepatectomy with I.V.C. by-pass. Experience of 11 cases (author's transl)]

22 malignant tumors of the liver in children have been treated so far at the "La Paz" Childrens Hospital. 11 cases underwent hemihepatectomy with intracaval by-pass. This technique is described and its advantages underlined.

[Surgical approach of retroperitoneal neuroblastoma in infancy (author's transl)]

Rarely retroperitoneal neuroblastoma is a well localized, encapsulated tumor, like it my appear somewhere else, as in the pelvic floor or mediastinum. Even with the same histological findings they are different from de point of view of invasion. Therefore the surgical approach should be different in each case. This is our main conclusion after de study performed in 48 cases operated upon in the last 8 years. We have tried three kinds of operations. 1. The so called curative, total resections. Performing a surgical ablation of the tumor and the organs macroscopically involved, either prior or after radiotherapy or quimiotherapy. At any risk, even of life in the early postoperative period. This kind of surgery has been undertaken in 34 cases with an early mortality of 9. The main aim of this technique is to divide the tumor in two across the supraaortic line well below the renal vessels and up to the diaphragm. In 18 cases the homolateral kidney was resected with the suprarrenal gland. Spleen and pancreas in 5 cases, colon in 4, and the inferior vena cava in 3. The survivors over 2 years are 19 cases. 2. Paliative resection, taking out the main tumor only, has been achieved in 4 cases, with the highest mortality because postoperative hemorrhage. We believed is a dangerous procedure. None of these children survived more than one year. 3. Biopsy and surgical macroscopic diagnosis of invasion plus placing clips at their margin has been carried out in 12 occasions. This had naturally the best early postoperative but not in the long run, none survived more than 2 years. A second look up with resection was undertaken in 3 cases with mortality of one. Most surgeons are puzzled when dealing with retroperitoneal neuroblastoma and some how disappointed before undertaking a long, difficult and highly risk operation, but in many instances still is about the only hope they may have.

[Primary prevention of rheumatic fever. Occurrence of beta hemolytic Streptococcus of the A group in 11,314 students in Magdalena Contreras]

A study was made in 11,314 school-age children to determine the prevalence of streptococcus pyogenes group A. The children studied belonged to a low socioeconomic group of one of the political boroughs of the Federal District. The prevalence found was 6.86%. There were no differences in the percentage of carriage according to the school surveyed or the school grade studied. However, marked differences were found when the presence of arthralgias was related to the carriage of streptococcus. Children complaining of artharlgias showed twice as much streptococcus in their pharynx than the ones not carrying it.

[Surgical malabsortion (author's transl)]

Two interesting aspects should be considered in intestinal malabsortion from the Surgical point of view. First, this sindrome may be caused by subobstructive lesions of the gut, which may be able of surgical correction. Second, malabsortion may follow certain operations performed in the gastrointestinal tract. Many of this problems are connected with alterations of the intestinal flora, and or a diminution in the obstructive intestinal surface. The clinical picture is not clear due to the pathological and surgical implications. The experience of the last 10 years is reviewed and conected with the following items, whem accompanied by not infectious diarrhea: a) Hiatus hernia and vaguectomy; b) Gastrointestinal by-pass; c) Intestinal atresia and stenosis; d) Small gut resections-Short bowel sindrome; e) Incompetence of the ileocecal valve.