Bordetella avium virulence measured in vivo and in vitro

Bordetella avium causes an upper-respiratory-tract disease called bordetellosis in birds. Bordetellosis shares many of the clinical and histopathological features of disease caused in mammals by Bordetella pertussis and Bordetella bronchiseptica. In this study we determined several parameters of infection in the domestic turkey, Meleagris galapavo, and compared these in vivo findings with an in vitro measure of adherence using turkey tracheal rings. In the in vivo experiments, we determined the effects of age, group size, infection duration, and interindividual spread of B. avium. Also, the effect of host genetic background on susceptibility was tested in the five major commercial turkey lines by infecting each with the parental B. avium strain and three B. avium insertion mutants. The mutant strains lacked either motility, the ability to agglutinate guinea pig erythrocytes, or the ability to produce dermonecrotic toxin. The susceptibilities of 1-day-old and 1-week-old turkeys to B. avium were the same, and challenge group size (5, 8, or 10 birds) had no effect upon the 50% infectious dose. Two weeks between inoculation and tracheal culture was optimal, since an avirulent mutant (unable to produce dermonecrotic toxin) persisted for a shorter time. Communicability of the B. avium parental strain between confined birds was modest, but a nonmotile mutant was less able to spread between birds. There were no host-associated differences in susceptibility to the parental strain and the three B. avium mutant strains just mentioned: in all turkey lines tested, the dermonecrotic toxin- and hemagglutination-negative mutants were avirulent whereas the nonmotile mutants showed no loss of virulence. Interestingly, the ability of a strain to cause disease in vivo correlated completely with its ability to adhere to ciliated tracheal cells in vitro.

Demography, clinical characteristics, psychological and abuse profiles, treatment, and long-term follow-up of patients with gastroparesis

Patients with gastroparesis frequently present challenging clinical, diagnostic, and therapeutic problems. Data from 146 gastroparesis patients seen over six years were analyzed. Patients were evaluated at the time of initial diagnosis and at the most recent follow-up in terms of gastric emptying and gastrointestinal symptomatology. The psychological status and physical and sexual abuse history in female idiopathic gastroparesis patients were ascertained and an association between those factors and gastrointestinal symptomatology was sought. Eighty-two percent of patients were females (mean age: 45 years old). The mean age for onset of gastroparesis was 33.7 years. The etiologies in 146 patients are: 36% idiopathic, 29% diabetic, 13% postgastric surgery, 7.5% Parkinson's disease, 4.8% collagen vascular disorders, 4.1% intestinal pseudoobstruction, and 6% miscellaneous causes. Subgroups were identified within the idiopathic group: 12 patients (23%) had a presentation consistent with a viral etiology, 48% had very prominent abdominal pain. Other subgroups were gastroesophageal reflux disease and nonulcer dyspepsia (19%), depression (23%), and onset of symptoms immediately after cholecystectomy (8%). Sixty-two percent of women with idiopathic gastroparesis reported a history of physical or sexual abuse, and physical abuse was significantly associated with abdominal pain, somatization, depression, and lifetime surgeries. At the end of the follow-up period, 74% required continuous prokinetic therapy, 22% were able to stop prokinetics, 5% had undergone gastrectomy, 6.2% went onto gastric electrical stimulation (pacing), and 7% had died. At some point 21% had required nutrition support with a feeding jejunostomy tube or periods of parenteral nutrition. A good response to pharmacological agents can be expected in the viral and dyspeptic subgroups of idiopathics, Parkinson's disease, and the majority of diabetics, whereas a poorer outcome to prokinetics can be expected in postgastrectomy patients, those with connective tissue disease, a subgroup of diabetics, and the subset of idiopathic gastroparesis dominated by abdominal pain and history of physical and sexual abuse. Appreciation of the different etiologies and psychological status of the patients may help predict response to prokinetic therapy.

[The characteristics of the effect of tuftsin on the behavior and on the level of biogenic amines in the brain of rats with differing resistance to acoustic stress]

The influence of tetrapeptide tuftsin (Tyr-Lys-Pro-Arg) on learning, exploratory activity, emotional behavior, and hypothalamic monoamine content was studied in Wistar rats with different resistance to stress induced by acoustic stimuli. Positive effects of taftsin were more pronounced in low-resistant rats. Administration of taftsin induced in these animals a significant increase in reactivity to stimuli of different modalities, the open-field exploratory activity, rate of alimentary conditioning and its modification in emotionally negative situation. Biochemical examinations showed that in rats with high resistance to stress taftsin administration led to a decrease in hypothalamic noradrenaline level and increase in dopamine and serotonin levels. On the contrary, in low-resistant animals taftsin increased the level of noradrenaline and decreased that of dopamine, serotonin, and 5-hydroxyindoleacetic acid. It is suggested that different behavioral effects of taftsin in stress-resistant and nonresistant rats are caused by its different influence on hypothalamic biogenic amines.

Plasmodium chabaudi chabaudi (AS): inflammatory cytokines and pathology in an erythrocytic-stage infection in mice

We have sought to characterize Plasmodium chabaudi chabaudi infection in mice for use as a model for malaria pathology. Different mouse strains vary in their susceptibility to the erythrocytic stages of this parasite and this is manifested not only in the outcome of infection (survival versus death) but also by differences in the numbers of circulating parasites at the peak of infection. We have shown that regardless of final outcome, both resistant and susceptible mice exhibit other parameters of disease such as loss in body weight and anemia. By contrast, other parameters such as hypothermia appear more severe in susceptible mice. The severe symptoms coincide with high levels of inflammatory cytokines in the circulation of susceptible mice, not seen in H-2-matched resistant mice. However, levels of mRNA for the same cytokines, measured in the spleen of the same mice was not significantly different between the two strains. Neutralization of IFN-gamma in vivo led to an increase in parasitemia, in both susceptible and resistant mice, but did not affect the final outcome of disease. Indeed, symptoms were exacerbated in the absence of IFN-gamma, presumably because of larger numbers of circulating parasites. These data suggest that IFN-gamma does not directly contribute to the lethal outcome of infection in susceptible strains of mice.

Abnormally high levels of cystatin S in submandibular glands, saliva, and gingiva of plaque-resistant rats

To identify salivary biomarkers of periodontal diseases, we used plaque-resistant and -susceptible rats as animal models. The levels of salivary cystatin S in saliva, salivary glands, and gingiva were tested in Nembutal-anesthetized young and adult plaque-resistant and -susceptible rats of both sexes with and without chronic treatment with isoproterenol. Isoproterenol was injected i.p. once a day for 4 or 6 consecutive days. Isoelectric focusing electrophoresis by the PhastSystem and the western blotting method were used to separate different proteins and to identify a salivary cystatin S band in these samples. The expression of salivary cystatin S mRNA was also determined by the northern blotting method. Depending upon the types of agonists, a few differences were observed in secretory functions between both strains of rats in both sexes, but the levels of salivary cystatin S in saliva elicited from the submandibular gland and in the extracts of the submandibular glands and gingiva were significantly higher in plaque-resistant rats when compared with those of plaque-susceptible rats in both sexes. However, no significant difference was seen between the strains after chronic treatment with isoproterenol. The N-terminal 26-amino-acid sequence of salivary cystatin S purified from submandibular saliva of plaque-resistant rats was identical with that purified from submandibular saliva of Sprague-Dawley rats subjected to chronic treatment with isoproterenol. The expression of salivary cystatin S mRNA was dramatic in the submandibular glands of the plaque-resistant rats and in the submandibular glands of Wistar rats subjected to chronic treatment with isoproterenol, but not in those of plaque-susceptible rats. These results suggest that salivary cystatin S might be a good biomarker in distinguishing between the two strains of rats and that its concentration is correlated with plaque resistance.

Factors determining pathogenicity of variants of ECHO 9 virus for newborn mice

While some strains of ECHO 9 virus were found to be completely incapable of multiplying in newborn mice or even of being adsorbed by their tissues (e.g., the prototype Hill strain), other naturally occurring strains readily multiplied even after inoculation of as little as 3 TCD(50) of virus. With the multiplying strains, the infection remained clinically inapparent except after inoculation of very large doses, usually in the range of 10(5) to 10(7.5) TCD(50). Investigation of the question why such large doses were required to produce paralysis indicated that for paralysis to occur virus multiplication had to reach a level of 10(8) TCD(50) or more within 4 days after inoculation of mice less than 1 day old. The reason for this was found in the fact that at 5 to 6 days of age the mice lost their susceptibility to paralysis even when multiplication was capable of progressing to the indicated high level. Thus, speed of multiplication and extent of muscle involvement before the 5th day of life were the determining factors. Passage in tissue culture had no effect except to yield a larger dose for inoculation, while serial propagation in mice resulted in a gradual enrichment of virus particles capable of more rapid multiplication in mice and in a concurrent greater paralytogenic activity of smaller doses.

Astrocyte-targeted expression of IFN-alpha1 protects mice from acute ocular herpes simplex virus type 1 infection

Type I IFNs (i.e., IFN-alpha and IFN-beta) play a key role in the host's innate defense against viral pathogens. To examine the biologic relevance of IFN-alpha to a viral pathogen within the confines of the nervous system, IFN-alpha1 transgenic mice whose transgene is under the control of the glial fibrillary acidic protein promoter (GFAP-IFN-alpha, astrocyte specific) were examined for resistance to an ocular herpes simplex virus type 1 (HSV-1) infection. GFAP-IFN-alpha mice expressed significantly higher levels of IFN-alphabeta (533 U) in the trigeminal ganglion compared with nontransgenic mice (70 U) 72 h postinfection that corresponded with a significant reduction in the mRNA expression of the HSV-1 immediate early gene infected cell polypeptide 27 and late gene VP16, as well as the chemokines monocyte-chemoattractant protein-1 and cytokine response gene-2 in the eye and trigeminal ganglion. Six days postinfection, the viral load and the expression of infected cell polypeptide 27, CD8, RANTES, IFN-gamma, and IFN-alpha mRNA levels were reduced in the trigeminal ganglion of GFAP-IFN-alpha mice compared with the wild-type mice. Following the establishment of HSV-1 latency (i.e., 30 days postinfection), only one of nine (11%) GFAP-IFN-alpha mice was found to be latent compared with seven of eight (88%) of the wild-type mice, as determined by the expression of the latency-associated transcript RNAs. Likewise, only three of nine GFAP-IFN-alpha mice screened showed seroconversion by day 30 postinfection compared with nine of ten wild-type mice screened. Collectively, the results show that the IFN-alpha1 transgenic mice are less susceptible to acute HSV-1 infection and the establishment of viral latency.

Effects of chronia excess salt ingestion. Evidence that genetic factors play an important role in susceptibility to experimental hypertension

Using the genetic technique of selective inbreeding, it has been possible to quickly develop two statistically separable populations from one unselected strain of Sprague-Dawley rats. One of these is very sensitive, the other very resistant, to the development of experimental hypertension from a high salt diet. It was suggested that similar genetic factors operate in man.

Changing viral susceptibility of a human cell line in continuous cultivation. I. Production of infective virus in a variant of the Chang conjunctival cell following infection with swine or N-WS influenza viruses

During its serial transfer and cultivation in this laboratory, a human conjunctival cell line (Chang) was observed to change in morphology. Concurrently no change was noted in the susceptibility of the cells to viruses capable of infecting the original cell line. However, it was noted that the derived variant cell line had acquired susceptibility to the induction of cytopathic effects and incomplete virus formation by several strains of influenza viruses. It was then discovered that swine influenza virus and the N-WS strain of influenza A virus could be serially propagated in the derived cell line with production of infective virus. The swine virus required adaptation, but the N-WS strain did not. N-WS and swine influenza viruses multiply with infective virus formation only in the variant conjunctival cell and in no other cell line. Antigenic, cytologic, and virologic evidence is presented that the influenza virus-susceptible variant cell is of human origin and is not a contaminating cell exogenously introduced. Transition of a cell line from complete insusceptibility to susceptibility to virus infection and multiplication has not been described previously.

Malnutrition, cardiac disease, and mortality: an integrated point of view

Malnutrition and hypoalbuminemia, which are prevalent in patients with end-stage renal disease (ESRD), are strong predictors of increased mortality. However, cardiovascular disease predominates among direct causes of death, whereas malnutrition appears to be of minor importance in this respect. Reports in the literature demonstrate that cardiac failure may cause malnutrition and that infection/inflammation may predispose to atherosclerosis as well as to catabolism and hypoalbuminemia. Proinflammatory cytokines, generated in response to cardiac failure, infection, and other inflammatory stimuli, appear to play a pivotal role by causing muscle wasting, hypoalbuminemia, and anorexia as well as reduced cardiac contractility and atherosclerotic vascular disease. We hypothesize that this scenario also applies to ESRD patients, in whom congestion, hypertension, cardiac failure, and ischemic cardiovascular disease are common. Malnutrition rarely may be the direct cause of death, except in elderly dialysis patients, but may contribute to a poor prognosis by aggravating pre-existing heart failure and increasing the susceptibility to infections.

Activation of natural killer cells in arthritis-susceptible but not arthritis-resistant mouse strains following Borrelia burgdorferi infection

Infection of susceptible mouse strains with Borrelia burgdorferi, the agent of Lyme disease, results in the development of arthritis. Components of the innate immune system may be important mediators of this pathology. To investigate the potential role of NK cells in development of experimental Lyme arthritis, we examined their activation in vivo in both resistant and susceptible mouse strains. Following inoculation of B. burgdorferi into the footpad, lymph node NK cells from susceptible C3H/HeJ (C3H) mice produced more gamma interferon than NK cells from resistant DBA/2J mice. Lymph node cells from susceptible C3H and AKR mice also had increased ability to lyse YAC-1 target cells 2 days following infection. Antibody depletion of NK cells from susceptible mice, however, did not alter the development of arthritis following B. burgdorferi challenge. In addition, NK cell depletion had little effect on spirochete burden. Thus, there is a marked activation of NK cells in susceptible mouse strains following infection. Although NK cells are not absolutely required for arthritis, events occurring prior to NK cell activation might be important in mediating pathology in experimental Lyme disease.

[Swallowing changes in cerebrovascular accidents: incidence, natural history, and repercussions on the nutritional status, morbidity, and mortality]

OBJECTIVE

To determine the frequency of dysphagia in CVA, its natural history and value as a risk factor of respiratory infection, malnutrition and death.

PATIENTS AND METHODS

A prospective study was made of 187 consecutive patients with cerebrovascular accidents (CVA). A standardized test for dysphagia was done during the first two days of the illness and repeated three days a week. The levels of urea, total proteins and albumin were determined on admission and on discharge. The patients were questioned by phone after 6 months.

RESULTS

There was dysphagia of liquids in 36.4% of the patients. The incidence of dysphagia for semisolids was of the same frequency but more severe. Coma was the cause of inability to swallow in 25.7% of the patients. During their stay in hospital one third of the patients with dysphagia died, one third became normal and one third still had dysphagia when they were discharged. After one week, one, three and six months respectively, the cure rate for dysphagia was 29.4%, 4.1%, 55.9% and 55.9%, and survival 83.8%, 67.6%, 61.8% and 60.3%. Thus after 6 months only 3 patients (4.4%) were alive and dysphagic. Half of the 'cures' occurred in the first week, and none occurred after more than 77 days. As compared to the non-dysphagic patients, the dysphagic patients had 10 times more risk of respiratory infection, 18 times higher risk of death, greater loss of albumin and less loss of urea.

CONCLUSIONS

There is a high prevalence of dysphagia in CVA and although functional prognosis is not unfavorable, respiratory infections, malnutrition and death are frequent.

Non-Hodgkin's lymphoma associated with Gaucher's disease

Gaucher's disease is an uncommon disorder which has been reported to be associated with an increased risk of lymphoproliferative disorders, including Non-Hodgkin's lymphoma (NHL). A new instance of such an association is described here. This was a 58 year-old-patient with adult type I Gaucher's disease who, one and a half year after the above diagnosis, presented with supraclavicular lymphadenopathy, massive splenomegaly, prominent retroperitoneal lymphadenopathy and increased serum LDH levels. This led to the diagnosis of large-cell NHL of B-cell type, successfully treated with chemotherapy. The previously published cases of Gaucher's disease associated with NHL as well as the possible mechanisms leading to this association are reviewed here.

Effect of dietary proteins and amino acids on the susceptibility of mice to bacterial infections

Young mice were maintained for periods of 1 to 6 weeks on experimental diets containing all known growth factors, but differing in their protein and amino acid contents. All diets were supplemented with L-cystine. The effect of the nutritional regimen on infection was tested by inoculating the animals with either one of four pathogens (Mycobacterium tuberculosis var. bovis, Mycobacterium fortuitum, Staphylococcus aureus, Klebsiella pneumoniae type C), and by observing the survival time. The infective dose was administered by either one of three routes: intravenous, intraperitoneal, or air-borne (aerosol). In some experiments, the animals were maintained in groups of five throughout the tests. In other experiments they were housed in individual cages. This difference in housing did not affect the results in a detectable manner. Mice fed diets containing 5 or 8 per cent casein as sole source of amino acid (except for cystine supplementation) proved more susceptible to the experimental diseases than did mice fed diets containing 15 or 20 per cent of the same protein. Susceptibility to infection developed when wheat gluten, or soybean α-protein, was substituted for casein—even in high concentrations (15 or 20 per cent). In one experiment, mice were fed a diet containing as sole source of amino acids a mixture of soybean and rice flour, so designed as to provide a protein concentration of 15 per cent, with an amino acid pattern similar to that of casein. These animals gained weight at the same rate as those fed a diet containing 15 per cent casein and they exhibited a satisfactory level of resistance to bacterial infection. The infection-enhancing effect of low casein concentration (5 and 8 per cent) could be corrected by supplementing the diet with the proper mixture of amino acids. This could be done using either synthetic or natural amino acids. In contrast, susceptibility to infection developed when low casein diets were supplemented with unbalanced mixtures of amino acids. The infection-enhancing effect of gluten diets could not be corrected by supplementing the latter with lysine even though this supplementation markedly improved weight gains in uninfected animals. It appears in conclusion that the relative proportion of the various amino acids in the diet is as important a factor as their total amount in conditioning resistance to bacterial infections. This effect of nutrition on resistance can be detected irrespective of the route of infection: intravenous, intraperitoneal, or air-borne. Moreover, the effect has been observed with two strains of mice differing markedly in their natural resistance to bacterial infection.

Synthesis of 4-hydroxy-3(2H)-furanone acyl derivatives and their anti-cataract effect on spontaneous cataract rats (ICR/f)

4-Hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF) and 2(or 5)-ethyl-4-hydroxy-5(or 2)-methyl-3(2H)-furanone (EHMF) are known to inhibit cataract development in spontaneous cataract rats (ICR/f). Forty-five acylated hydroxyfuranone derivatives were designed and synthesized for an anti-cataract test, and their hydrophobic constants were also tested. Among these derivatives, 2,5-dimethyl-4-pivaloyloxy-3(2H)-furanone (HDMF pivalate) exerted a marked protective effect against the development of cataract in a galactose-induced model using cultured rat lens (in vitro). When tested on an ICR/f cataract model (in vivo), HDMF pivalate showed more significant inhibition of cataract development than parent compound HDMF. This derivative is more lipophilic than HDMF, so that HDMF pivalate can penetrate the cornea more easily than HDMF. The inhibition of cataract development by HDMF converted from HDMF pivalate is supported by the fact that HDMF was observed in the lens of ICR/f rats treated with HDMF pivalate.

Higher seizure susceptibility and enhanced tyrosine phosphorylation of N-methyl-D-aspartate receptor subunit 2B in fyn transgenic mice

Earlier work has suggested that Fyn tyrosine kinase plays an important role in synaptic plasticity. To understand the downstream targets of Fyn signaling cascade in neurons, we generated transgenic mice expressing either a constitutively activated form of Fyn or native Fyn in neurons of the forebrain. Transgenic mice expressing mutant Fyn exhibited higher seizure activity and were prone to sudden death. Mice overexpressing native Fyn did not show such an obvious epileptic phenotype, but they exhibited accelerated kindling in response to once-daily stimulation of the amygdala. Tyrosine phosphorylation of at least three proteins was enhanced in the forebrains of both native and mutant fyn transgenic mice; tyrosine phosphorylation of these three proteins was reduced in fyn knockout mice, suggesting that they are substrates of Fyn. One of these proteins was identified as the subunit 2B (NR2B) of the N-methyl-D-aspartate (NMDA) receptor. Administration of MK-801, a noncompetitive NMDA receptor antagonist, retarded kindling in mice overexpressing native Fyn, as well as wild-type mice, suggests that the accelerated kindling in mice overexpressing Fyn is also mediated by the NMDA receptor activity. Our results thus suggest that tyrosine phosphorylation by Fyn might be involved in regulation of the susceptibility of kindling, one form of the NMDA receptor-mediated neuronal plasticity.