A viral subunit immunogen for porcine transmissible gastroenteritis.

An immunogenic component was isolated from both the Illinois (propagated in young swine) and the Miller (cell culture-adapted) strains of porcine transmissible gastroenteritis (TGE) virus. The viral subunit was released from the virion by sonication and was separated from intact virus and other viral components by isopycnic centrifugation. It had a buoyant density in sucrose of 1.02 g/ml. Further purification consisted of gel filtration through Sephadex G200, in which process the immunogen, with a molecular weight of approximately 25 000, was the last component to be eluted. A group of ten young, weaned swine, inoculated intramuscularly with two or three 1-mg doses of the viral subunit were protected against challenge with virulent TGE virus, probably by the induction of secretory IgA. The immunogen also induced a humoral immune response of variable magnitude (titers ranging from 8 to 5 625) in the animals. These antibodies are not believed to be directly related to protection against infection. They can, however, be easily identified by serologic procedures and may serve as a convenient indicator of responsiveness to the TGE viral immunogen.

Candidosis of the genital tract in non-pregnant women.

Of 300 non-pregnant women seen in an STD clinic, 94 (31.3%) harboured C. albicans or C. glabrata in the genital tract; 84 of these women (89.4%) had at least one moderate or marked symptom or clinical sign. Of the 94 women with Candida, 50 had another genital infection; 38% of these 50 women had at least one moderate or marked symptom or clinical sign, compared with 75% of the 44 women with no other infection. This difference is significant. Of the 146 women taking oral contraceptives, 51 (34.9%) had Candida, compared with 43 (27.9%) of the 154 women who were not. The incidence of trichomoniasis, anaerobic vaginitis and non-specific genital infection was lower among women with Candida than among the others.

PIP: This prospective study was aimed at determining the prevalence of specific signs and symptoms in nonpregnant women harboring Candida albicans in the lower genital tract. Of 300 women randomly selected from a sexually transmitted diseases clinic, 93 (31%) harbored C albicans and 1 carried C glabrata in the lower genital tract. Perineal isolations were recorded in 58 (62%) of the 94 women with Candida. 50 of the women had another genital infection. 84 (89%) of the 94 women with Candida had at least 1 moderate or marked symptom or clinical sign, predominantly vaginal discharge. Of the 300 women studied, 146 were using oral contraceptives (OCs); 51 (35%) of OC users had Candida compared with 43 (28%) of nonusers--a nonsignificant difference. Finally, the incidence of trichomoniasis, anaerobic vaginitis, and other nonspecific genital infection was lower among women with Candida than among the others.

Identification of porcine transmissible gastroenteritis virus in house flies (Musca domestica Linneaus).

Transmissible gastroenteritis (TGE) virus was detected in house flies (Musca domestica Linneaus) by staining with specific fluorescent antibody. The flies were collected within a swine confinement facility in which TGE was enzootic. Laboratory-reared flies were infected experimentally with TGE virus and the virus was recovered from the insects for 72 hours after infection. The TGE virus was identified both by the fluorescent antibody technique and by isolation in cell culture. The nature of plaque formation in cell monolayers inoculated with the virus passaged through flies changed from a large plaque (4 mm or greater in diameter) to a small plaque (1 mm in diameter) over the period. Large plaques were observed early after infection and were attributed to TGE virus mechanically carried by the flies. Small plaques occurred 8 to 12 hours after infection and were considered to be produced by virus replicated in the dipterous cell.

Investigation of causative agents of bovine respiratory tract disease in a beef cow-calf herd with an early weaning program.

Serum samples were collected from early weaned fall calves shortly after the onset of respiratory tract disease. Antibody titers to infectious bovine rhinotracheitis (IBR) virus, parainfluenza type 3 (PI-3) virus, bovine viral diarrhea (BVD) virus, bovine adenovirus type 3 (BAV-3), and bovine respiratory syncytial virus (BRSV) were determined on paired (acute and convalescent) serums. Seroconversion rate (a fourfold or greater rise in antibody titer) for IBR virus was 4.3%, PI-3 virus--16.3%, BVD virus--9.6%, and BAV-3--2.2%. Seroconversion for BRSV was 45.4%. An increased rate of seroconversion for IBR, PI-3, and BVD viruses and BAV-3 was observed in the presence of BRSV seroconversion. These results suggest that BRSV may facilitate infection by other viruses. Results of virus isolation procedures from these calves were negative.

Characterization and identification of a bovine respiratory syncytial virus isolated from young calves.

Two identical viruses designated 371 and 375 were recovered from nasal secretions of 2 of 7 calves in a beef cow-calf herd in which calves (45 to 105 days of age) had signs of acute respiratory tract disease. The cytopathic, morphologic and physico-chemical characteristics of the isolates were those of bovine respiratory syncytial virus. Although a humoral antibody response to bovine respiratory syncytial virus was not observed, it was concluded that this virus probably had a part in the respiratory tract disease in these calves.

Neutralizing antibody to bovine adenovirus serotype 3 in healthy cattle and cattle with respiratory tract disease.

A serosurvey of healthy cattle for the presence of serum-neutralizing antibody to bovine adenovirus serotype 3 (BAV-3) established the widespread prevalence of this agent in Iowa cattle. Of the animals studied, 19.1% (involving 157 calves that represented 40 outbreaks (herds) of respiratory tract disease) seroconverted to BAV-3. This pathogen was implicated serologically as being involved in the cause of respiratory tract disease in six herds. Bovine adenovirus serotype 3 was isolated from cattle in two of these herds. Based on seroconversion and lack of isolation of other viral agents, it appeared that BAV-3 could have been the sole virus involved in the respiratory tract disease in one of these two herds. In another herd, seroconversion was observed only to BAV-3, but other viral agents as well as BAV-3 were isolated. The remaining four herds presented a problem because the cattle seroconverted to more than one agent and additional viral agents were isolated from some animals. Whether the disease manifestations observed in these six herds were due solely or in part to BAV-3 can only be speculated. Cattle are capable of undergoing a natural infection, as indicated by seroconversion, in the absence of overt clinical signs of illness. It appears that maternal (passive) antibody decreases to a point at which infection by this virus becomes possible and an active immune response occurs.

A rabies epidemic in recently captured skunks.

An epidemic of rabies occurred within a colony of captive skunks (Mephitis mephitis). One of the animals has been infected with the virus in the wild and developed clinical illness near 7 weeks after capture. She transmitted the virus to three of her five offspring and one other adult. The disease spread to additional skunks when orphaned infants were adopted by lactating females. Although the animals were in close contact with each other, the epidemic spread slowly. Furious rabies generally did not occur and frequently rabid skunks were found dead without any clinical signs of the disease having been observed.

Rabies antibodies in sera of wild birds.

Three hundred forty-three birds representing six orders and 22 species were examined serologically for antibodies against rabies. Low passive hemagglutination titers were observed in 23 samples. Fifteen of 65 (23.1%) predatory birds and 8 of 278 (2.9%) non-predatory birds were positive. Rabies antibody positive sera from non-predatory species were from species commonly thought to be scavengers suggesting the importance of the oral route for the presentation of rabies virus to birds.

Experimental rabies in a great horned owl.

A great horned owl (Bubo virginianus) was fed the carcass of an experimentally infected rabid skunk. The bird developed antibody titer to rabies, detected by passive haemagglutination, 27 days after oral inoculation by ingestion. The owl suppressed the infection until corticosteroid administration, after which a maximum antibody titer was attained. Evidence of active rabies viral infection was seen by fluorescent antibody staining of oral swabs, corneal impression smears and histologic tissue smears, by suckling mouse inoculation of oral swab washings, and by transmission electron microcopy. No clinical signs of rabies virus infection were observed.

Fine tuned modulation of the motor system by adjectives expressing positive and negative properties.

Using transcranial magnetic stimulation (TMS), motor evoked potentials (MEPs) were recorded from two antagonistic muscles, the first dorsal interosseus (FDI) of the hand and the extensor communis digitorum (EC) of the forearm. FDI is involved in grasping actions and EC in releasing. TMS pulses were delivered while participants were reading adjectives expressing either negative or positive pragmatic properties, at 150 ms after presentation of language material. Overall findings showed an interaction of adjective type (positive, negative) and muscle (FDI, EC), the effect being driven by a significant difference for negative adjectives. Further analysis aimed at investigating the effectiveness of positive adjectives showed a similar, but opposite, pattern of effects for the positive words in the initial two blocks. The present results indicate that, as for verbs and nouns, adjectives recruit the sensorimotor system, and their processing is best explained by an embodiment rather than an amodal approach to language.

Action observation versus motor imagery in learning a complex motor task: a short review of literature and a kinematics study.

Both motor imagery and action observation have been shown to play a role in learning or re-learning complex motor tasks. According to a well accepted view they share a common neurophysiological basis in the mirror neuron system. Neurons within this system discharge when individuals perform a specific action and when they look at another individual performing the same or a motorically related action. In the present paper, after a short review of literature on the role of action observation and motor imagery in motor learning, we report the results of a kinematics study where we directly compared motor imagery and action observation in learning a novel complex motor task. This involved movement of the right hand and foot in the same angular direction (in-phase movement), while at the same time moving the left hand and foot in an opposite angular direction (anti-phase movement), all at a frequency of 1Hz. Motor learning was assessed through kinematics recording of wrists and ankles. The results showed that action observation is better than motor imagery as a strategy for learning a novel complex motor task, at least in the fast early phase of motor learning. We forward that these results may have important implications in educational activities, sport training and neurorehabilitation.

Passive haemagglutination test for antibodies against rabies virus.

All the procedures now available for the measurement of rabies virus antibodies in serum have certain disadvantages. The serum neutralization test (SN), whether carried out by assay in mice or by the plaque-reduction technique, requires several days before the titrations are completed, necessitates special facilities for keeping large numbers of animals and tissue-culture plates, and is relatively expensive. A complement-fixation test is very insensitive, giving low titres in comparison with SN tests, and a haemagglutination-inhibition procedure is complicated by the presence of nonspecific reactions. A rabies passive haemagglutination technique (RPHA), developed to overcome many of these problems, is described.Titres obtained with human sera by the RPHA procedure correlated well with those obtained by SN tests. Both IgG and IgM classes of antibodies were measured by the RPHA procedure; however, it appeared to be more sensitive for detecting IgM than was the SN test and, therefore, gave higher titres for this class of immunoglobulins.

IgA and IgG antibodies to Candida albicans in the genital tract secretions of women with or without vaginal candidosis.

Levels of anti-Candida albicans immunoglobulin A (IgA) and IgG were measured by enzyme-linked immunosorbent assay in serum and cervicovaginal secretions from 64 non-pregnant women with vaginal candidosis and 158 uninfected non-pregnant women. Specific IgA and IgG were detected in the serum and secretions of all 222 women. There was no significant difference between the mean levels of specific IgA or IgG in secretions from women with candidosis and those of uninfected women. Neither was there a significant difference between mean levels of specific IgA or IgG when women using oral contraception were compared with others who were not. There was a significant correlation between the levels of IgA and IgG in serum and secretions from women with candidosis and from uninfected women. Blastospore and hyphal forms of C. albicans were seen in vaginal smears from 29 of the 64 women with culture-proven candidosis: in nine, both IgA- and IgG-coated C. albicans cells were recovered from the genital tract; in a tenth, IgG-coated cells were found.

Lactogenic immunity to transmissible gastroenteritis virus induced by a subunit immunogen.

A subunit prepared from transmissible gastroenteritis (TGE) virus and used to immunize 24 gilts prior to farrowing induced production of specific antibody in the serum and milk. Challenge of pigs, two to seven days of age and suckling on the vaccinated gilts, with the Illinois strain of TGE virus resulted in morbidity of 28% and mortality of 4% as compared with 100 and 73%, respectively, for control piglets. Piglets nursing on a sow which had been immunized approximately 10 months previously were not protected, indicating that lactogenic immunity may be of short duration. Revaccination of this animal resulted in an anamnestic response.