First record of Aspiculuris tetraptera (Nitzsch, 1821) (Nematoda : Oxyuroidea) and Dollfusentis chandleri (Golvan, 1969) (Acanthocephala : Illiosentidae) in Haemulon sciurus (Shaw 1803) (Pisces : Pomadasyidae)

Forty specimens of Haemulon sciurus were examined for endoparasites and this paper refers to the recovered Nematodes and Acanthocephalans. Aspiculuris tetraptera is for the first time referred in fish and Dollfusentis chandleri is recorded in Brazil and in a new host.

Immunosorbent electron microscopy for detection of viruses

This chapter discusses the newer modifications of immunosorbent electron microscopy (ISEM) methods in both plant and animal virology. ISEM methods presented in the chapter include all the techniques where the “solid phase principle” is essential in a way similar to other solid phase immunoassays. These methods include (1) the antibody-coated grid technique (AB-CGT); (2) the protein A-coated grid technique (PA-CGT); (3) the protein A-coated bacteria technique (PA-CBT); and (4) the antigen-coated grid technique (AG-CGT). In all ISEM methods, one of the components of the system is adsorbed to a solid phase. In AG-CGT, PA-CGT, and AB-CGT, one of the reagents is adsorbed to an electron microscopic grid, while in PA-CBT protein A is naturally present on the surface of a bacterium that serves as a solid support. In ISEM methods, the viruses can be statistically evaluated and numerically expressed as number of virions per unit of area, and can, therefore, be statistically evaluated. Thus, these methods optimize the results of a test by quantifying the effects of the quality of the supporting grid, the time of adsorption, the pH, the presence of salts, and the type of staining. The ISEM also permits a detailed study of antigenic variations in the same genus of virus, and thus would visually pinpoint the type or strain differences.

Effects of bombesin on gastrin and gastric acid secretion in patients with duodenal ulcer

The effect of bombesin, a possible neurotransmitter of gastrin release, upon gastrin and gastric acid secretion was investigated in 25 patients with duodenal ulcer and in 16 normal subjects. In patients with duodenal ulcer bombesin (10 ng/kg/min) produced an increase in plasma gastrin output (median 22.4 (range 7.5-75.8) pmol/l/min) similar to that obtained in normal subjects (median 24.4 (range 5.8-56.5) pmol/l/min), whereas gastrin stimulated by a meal was significantly higher in the group of patients with duodenal ulcer (median 20.7 (range 9.2-42.9) vs 16.2 (range 3.4-22.2) p<0.05). Peak acid output induced by bombesin was significantly higher in patients with duodenal ulcer than in normal subjects (median 24.4 (range 9.0-63.8) vs 14.0 (range 3.0-24.8) mmol/h, p<0.05) despite identical gastrin outputs. The ratio (%) obtained by dividing the acid secretory response to bombesin by the response to pentagastrin, however, was similar in both normal subjects and patients with duodenal ulcer (median 55 (range 20-116) vs 58 (range 31-95) respectively). The difference between the gastrin response to food and bombesin could be explained by the fact that bombesin releases gastrin directly, whereas a protein meal involves several mechanisms (neural, peptidergic, paracrine, endocrine), either stimulatory or inhibitory. The above results indicate that a higher concentration in antral and/or duodenal gastrin is unlikely to be present in patients with duodenal ulcer. An increased parietal cell mass could explain the higher gastric acid response after bombesin infusion in our group of patients with duodenal ulcer.

Effect of bombesin on lower esophageal sphincter pressure in humans

Intravenous infusion of bombesin in humans results in increased serum gastrin levels and increased lower esophageal sphincter pressure. To differentiate a gastrin- from a nongastrin-mediated mechanism, the effect of intravenous bombesin infusion on lower esophageal sphincter pressure was studied in 5 healthy subjects and in 5 antrectomized patients. Lower esophageal sphincter pressure was recorded by three continuously perfused catheters with side-openings located 5 mm apart. Blood samples were taken at regular intervals during the study periods to assay gastrin and pancreatic polypeptide. Manometric tracings and blood samples were coded and evaluated blindly. Lower esophageal sphincter pressure increased during bombesin infusion both in normal and antrectomized subjects. The increase had a delayed onset and persisted after discontinuation of bombesin. No correlation was found between lower esophageal sphincter pressure and serum gastrin or pancreatic polypeptide values. These data indicate that the effect of bombesin on lower esophageal sphincter pressure is not gastrin or pancreatic polypeptide mediated.

About some trematodes parasites of Haemulon sciurus (Shaw, 1803)

From September, 1980 to August, 1981 forty specimens of Haemulon sciurus from "Praia da Ribeira, Ilha do Governador", Rio de Janeiro State, were examined for parasites. In this paper, parcial results concerning only the collected trematodes are reported: Diplomonorchis leiostomi Hopkins, 1941 (first record in Brazil and in a new host); Lasiotocus beauforti (Hopkins, 1941) Thomas, 1959 (new host record); Genolopa ampullacea Linton, 1910; Parahemiurus merus (Linton, 1910) Yamaguti, 1938 (new host record): Aponurus pyriformis (Linton, 1910) Overstreet, 1973 and Diplangus paxillus Linton, 1910. Figures, measurements and comments of each species are given.

Transmission and scanning electron microscopical studies in the tegument of male Schistosoma mansoni after oxamniquine treatment

Schistosoma mansoni recovered from experimentally infected mice orally treated with oxamniquine were studied by transmission and scanning electron microscopy. The worms were examined 24 hours, 3, 7 and 10 days after a single dose of 100 mg/Kg of the drug. After oxamniquine treatment significant structural alterations were observed in tegumental, muscular and parenchymal levels. The initial alterations were confined to basal vacuolation in the tegument and to structural disorganization both in tegumental and non tegumental cells. Ten days after treatment, intercellular oedema became more prominent originating "bubble-like" lesions with varied dimensions. The intercellular oedema leading to the "bubble" formation seems to be the most striking feature caused by oxamniquine treatment.

Neoapocreadium chabaudi sp. n. (Apocreadiidae) and Schikhobalotrema acuta (Linton, 1910) (Haplosplanchnidae) trematodes parasites of marine fishes in Brazil

Neoapocreadium chabaudi sp. n. (Digenea, Apocreadiidae) is described from the intestine of a marine fish Stephanolepis hispidus from Brazil, and the genus Schikhobalotrema Skrjabin & Guschanskaja, 1955 represented by its type species S. acuta (Linton, 1910) Skrjabin and Guschanskaja, 1955, is for the first time reported from the intestine of Strongylura marina in Brazil. N. chabaudi sp. n. is more closely related to N. angustum (Sogandares-Bernal, 1959) from which differs mainly in the size of the eggs, by the presence of intercecal vitelline follicles in the region between the testes and acetabulum, and by the large genital atrium.

Maritremopsis mariettavogeae sp. n. (Trematoda, Microphallidae) and Amphimerus lancea (Diesing, 1850) (Trematoda, Opisthorchiidae) parasites of Nectomys squamipes (Rodentia) in Brazil

In this paper two species of trematodes recovered from nectomys squamipes from Goiás State, Brazil, are presented. Maritremopsis mariettavogeae sp. n. is compared to M. proxilum (Caballero & Montero-Gei, 1961) and M. belopolskaiae (Caballero, 1964). Amphimerus lancea originally described from a cetacean host, is for the first time referred in a rodent.

Interaction of polyunsaturated fatty acids with animal cells and enveloped viruses

Essential unsaturated fatty acids such as oleic, linoleic, or arachidonic were incorporated into the phospholipids of animal cells and induced in them a change in the fluidity of their membranes. Exposure of enveloped viruses such as arbo-, myxo-, paramyxo-, or herpesviruses to micromolar concentrations of these fatty acids (which are not toxic to animal cells) caused rapid loss of infectivity of these viruses. Naked viruses such as encephalomyocarditis virus, polio virus or simian virus 40 were not affected by incubation with linoleic acid. The loss of infectivity was attributed to a disruption of the lipoprotein envelope of these virions, as observed in an electron microscope.

Unsaturated free fatty acids inactivate animal enveloped viruses

Unsaturated free fatty acids such as oleic, arachidonic or linoleic at concentrations of 5-25 microgram/ml inactivate enveloped viruses such as herpes, influenza, Sendai, Sindbis within minutes of contact. At these concentrations the fatty acids are inocuous to animal host cells in vitro. Naked viruses, such as polio, SV40 or EMC are not affected by these acids. Saturated stearic acid does not inactivate any viruses at concentrations tested. Though the mode of action of unsaturated fatty acids is not understood, electronmicrographs of enveloped viruses treated by them indicate that the inactivation is associated with disintegration of the virus envelope.

Solid-phase immune electron microscopy (SPIEM) for rapid viral diagnosis

Immune electron microscopy (IEM) is one of the fastest and most sensitive methods for the detection and diagnosis of viruses. This technique is based on formation of immune complexes of the virus with its corresponding antibody. In IEM optimal precipitation depends on a correct ratio, and there is a prozone effect. These problems can be overcome by using the solid-phase immune electron microscopic (SPIEM) technique. In this technique the antibody is attached to a particle which is used for 'fishing' the virus to be examined out of the suspension. After low speed centrifugation the preparation is treated either for observation in the transmission electron microscope or in the scanning electron microscope. In 'positive' samples the virus is seen attached to the surface of the particle. We report here results with S. aureus as the solid phase for the detection of Sindbis virus. The anti-Sindbis gamma globulins are attached to the bacteria by means of protein A present on their surface.

Nature of permeability changes in membrane of HeLa cells adsorbing Sendai virus

Adsorption of Sendai virus to HeLa cells induced in them an increased permeability to K+, Na+, Ca++, deoxyglucose, but not to fluorescein. The stimulation of uptake of 42K was temperature-dependent, did not occur below 15 degrees C, and was not inhibited by ouabain. The virus-induced increase in the uptake and release of 42K and of 3H deoxyglucose could not be mimicked by treatment of cells with linoleic acid, a procedure which increased the fluidity of the cellular membranes. The stimulatory effect of 0.5 mM ATP on the release of deoxyglucose was enhanced several fold in the presence of Sendai virus. These results seem to indicate the possible involvement of membranal enzymes such as e.g. protein kinase in the permeability changes induced by Sendai virus.

Herpes simplex virus phosphoproteins. I. Phosphate cycles on and off some viral polypeptides and can alter their affinity for DNA

We report on phosphorylation, the stability of the bound phosphate, and the properties of several phosphorylated infected-cell polypeptides (ICPs) synthesized in cells infected with herpes simplex virus 1 and 2. Our results and conclusions are as follows. (i) Phosphorylation of ICPs occurs by at least two different pathways. Thus, the 4a and 4c electrophoretic forms of ICP 4 were labeled with 32P during a pulse concurrently with their synthesis, whereas ICP 22 and ICP 27 were labeled with 32P only during a subsequent chase in the presence of unlabeled phosphate. (ii) Pulse chase studies with [35S]methionine and 32P indicate that whereas most polypeptides are stable, the bound phosphate with few exceptions cycles on and off. Of special interest is the observation that the phosphate bound to ICP 4a and 4c cycles on and off, whereas that bound to ICP 4b is stably associated. Similar cycling was observed for ICP 6, 11, 22, and 27. The observation that 4a and 4c can be phosphorylated as late as 24 h after infection, i.e., long after their synthesis ceases, suggests that all three forms may have defined functions that persist throughout the reproductive cycle. (iii) All three forms of ICP 4 can be the translational products of only one of two copies of the ICP 4 gene in the viral genome. (iv) Analyses of the distribution of the viral proteins within the cell indicate that phosphorylation is not a major determinant in the compartmentalization of most viral phosphoproteins. (v) Comparisons of the binding to DNA-cellulose of artificial mixtures of 32P- and [35S]methionine-labeled proteins from infected cells indicate that phosphorylation in some instances enhances (e.g., ICP 29) and in other instances decreases (e.g., ICP 6) binding affinity for DNA. In light of previous reports that some of the proteins identified as phosphoproteins have regulatory functions, the data suggest that phosphorylation may modify the activity of regulatory proteins in herpes simplex virus-infected cells.

Fluorescence polarization of DPH-labeled cells adsorbing viruses and its diagnostic potential

Mammalian or avian cells were labeled with a fluorescent probe DPH (1,6-diphenyl-1,3,5-hexatriene). Within a few minutes after adsorption of various naked and enveloped viruses, the degree of fluorescence polarization (P) of the DPH embedded in the adsorbing cells as measured at 37 degrees C, was reduced, a finding indicating a decrease in the microviscosity of the lipids in the cell membrane. This change of fluidity was proportional to the concentration of the adsorbing virus and could be abolished or inhibited by homologous specific antiviral sera, but not by heterologous sera. Potential use of fluorescence polarization tests is described for titration of virus concentration, as well as for serological identification of a virus.

Oxytalan fibers in the Schistosoma mansoni tegument

In order to elucidate the nature of the fibrous network present in Schistosoma mansoni tegument, adult worms were studied by light and electron microscopy. It was suggested that this network is formed by bundles of tubular microfibrils 10--12 nm in diameter, similar to oxytalan microfibrils present in higher animals.

Schistosome motility in saline media

The authors observed the motility of 1067 worms used as a biological parameter indicating the vitality of the parasites, to define the survival time of S. mansoni males and females in 0,85% NaCl and PBS. Among the worms observed in 0,85% NaCl the mean time of survival in minutes was 204 for males and 240 for females and in PBS it was 267 min. for males and 344 min. for females. All the tested differences (media, sex; sex for saline group; sex for PBS group) were significant at a 0.0001 level.

Early changes in the membrane of HeLa cells adsorbing Sendai virus under conditions of fusion

Adsorption of Sendai virus at high multiplicity (500-1,000 HAU/10(6) cells) to HeLa cells grown in monolayers causes immediate changes in the ion barrier of the cell membrane, as well as changes in the morphology of the virus-treated cells. Within minutes of adsorption the cells begin to lose potassium and an extensive influx of ions into the cells occurs. Concomitantly with these changes, the cell membrane becomes depolarized, and the resting potential across its membrane decreases. Twenty to sixty minutes post adsorption the damage to the cell membrane is repaired, and both the potassium uptake and the resting potential return to their pre-exposure values. Scanning electron-micrographs of Sendai infected cells incubated at 37 degrees C show formation of bridging microvilli in a zipper-like fashion within two to five minutes post-adsorption; 30 to 60 minutes thereafter the majority of cells in the monolayer are fused. Biochemical changes induced by virus adsorption and the role of Ca++ ions in the observed effects are discussed.

A passive hemagglutination test for detecting bovine serum albumin antibodies

A microtiter passive hemagglutination test is described for detecting and titrating antibodies in chickens. Chicken erythrocytes are coated with antigen (bovine serum albumin = BSA) in the presence of 0.25% glutaraldehyde. Such sensitized erythrocytes are agglutinated in the presence of antibodies against BSA. The sensitivity and specificity of the test are not affected by salt concentrations in the range of 0.9-9%. This test measures the course of antibody response in chickens immunized with BSA.

Increase in lipid fluidity of cellular membranes induced by adsorption of RNA and DNA virions

Changes in the dynamic behavior of membrane lipids of mammalian cells induced by adsorption of animal viruses were quantitatively monitored by fluorescence polarization analysis with the aid of the fluorescent probe 1,6-diphenyl 1,3,5-hexatriene embedded in the surface membrane lipid core of intact cells. Adsorption of encephalomyocarditis, West Nile, and polyoma viruses to hamster (baby hamster kidney) and mouse (3T3) cells is accompanied by a rapid and significant increase in the degree of fluidity of membrane lipids of the infected cells. These changes in membrane fluidity, which are virus dose dependent, are inhibited by low temperature and by treatment of the cells before-hand with compounds known to block viral receptors on the cell surface. It is suggested that increase in membrane lipid fluidity, induced by the adsorption of virions, is an early event in the process of cell-virus interactions.

Picorna- and togavirus infection of cells detected by gas chromatography

Viral infection of cells causes chemical and metabolic changes, which can be detected by gas chromatography (GC) of ether extracts of supernatant fluids and cell homogenates before any significant damage to the cells is observable microscopically. The characteristic and specific GC patterns obtained from BHK-21 and Vero cell cultures infected with encephalomyocarditis, polio, echoviruses, and a togavirus make it possible to distinguish between these infecting viruses. The appearance of 1 or 2 compounds, represented by GC peaks with TR values of 302 and 677 seconds seems to be specific for these viruses. Other peaks found in the supernatant media 1-2 hours after infection probably represent cell constituents leaking into the medium as a result of damage to the cell membrane by the invading virus.

The fate of protein subunits of parainfluenza (Sendai) virus after adsorption to NIL8 hamster embryo cells

Adsorption of u.v.-inactivated Sendai virus on to NIL8 hamster cells causes fusion of the cells into polykaryocytes within 2 h. "Infected" cells were incubated at 37 degrees C for periods of 10 min to 8 h and their surface proteins iodinated with [125I] catalysed by peroxidase. Structural components of the viral envelope, such as haemagglutin-neuraminidase (HN) and probably also the fusion protein (F) were detected in the cell membrane for periods up to 4 h post infection.