Quiescent Infection Research Articles

P-134 - Inhibition of viral quiescent infection (1) antiviral effects of amino acid derivatives on mice infected with Herpes virus

P-134 - Inhibition of viral quiescent infection (1) antiviral effects of amino acid derivatives on mice infected with Herpes virus

Otitis Media with Effusion: Results of Treatment with a Short Course of Oral Prednisone or Intranasal Beclomethasone Aerosol

A short course of prednisone suspension given in a decreasing dosage schedule for up to ten days was often effective (68%) in resolving mucoid otitis media with effusion (OME, middle ear effusion). No significant side effects were noted. Concommitant administration of sulfisoxazole suspension may have reduced the likelihood of activation of a quiescent infection of the middle ear. During the eight-month mean follow-up period, reaccumulation of the effusion was detected in 21% of the successfully treated children. Preliminary results of an unrelated, pilot project using intranasal beclomethasone dipropionate aerosol suggests that this novel method also may be efficacious in the treatment of OME.

Quiescent fruit infections of peach, apricot, and plum in New Zealand caused by the brown rot fungus Sclerotinia fructicola

Abstract Studies showed that a quiescent infection of stone fruits by the brown rot pathogen, Sclerotinia fructicola, previously reported in Australia, also occurred in New Zealand on peach, apricot, and plum fruits. The infections occurred in small, superficial, halo-shaped blemishes, quite distinct from other fungal infections. Quiescent infections of developing fruits occurred during prolonged warm, wet periods between late bloom (September) and January, and were first observed in late October-early November. Sources of inoculum were the current season's blighted blossoms or fruit “mummies” in the tree, and transport of inoculum was by rain splashing. Degree of quiescent fruit infection in trees was closely linked to that of blossom blight, being reduced when blossom blight was controlled with fungicides. Reactivation of quiescent infections occurred during warm, wet periods, resulting in decay of green or ripe fruit. When quiescent infection was severe a green fruit “cover” spray programme was necessa...

Cervical bacterial flora in patients with gynecologic malignancies

Radiation and gynecologic oncologists agree that pelvic irradiation in the presence of pelvic inflammatory disease, parametritis, or pyometra can be catastrophic. A temperature elevation in a patient having intrauterine radiation is very perplexing. This study was designed to investigate one of the three reported etiologies for this condition. Some investigators have suggested an exacerbation of a quiescent infection as a possible etiology because of the necrotic condition of many cancerous cervices. Aerobic, anaerobic, and fungus cultures were performed on 32 patients prior to intrauterine administration of cesium. The organisms cultured were similar to those identified as the normal cervical flora. The frequency of the organisms seemed independent of the amount of irradlation. The number of organisms cultured did not vary with the use or nonuse of cleansing vaginal suppositories. This study indicated no increase in bacterial growth in these cancerous necrotic cervices; also it did not indicate the growth of any unusual pathologic bacteria.

Latent Infections by Fungi

Before a pathogenic fungus establishes a parasitic relationship with its host plant, a number of stages in the life cycle of the fungus will have been passed. After spores land on the surface of the host, germination takes place if circumstances are favor­ able. A spore can germinate immediately after landing, or it can take some time before germination occurs. During this time, the spores must remain viable; the fungus can be isolated by washing the spores from the host and plating out this suspension or, when stuck to the surface, by plating out pieces of the host tissue. This period between landing and germination is sometimes referred to as a latent infection, although no infection has yet taken place. After germination has occurred, the germ tube can penetrate directly into the host tissue, with or without the development of superficial mycelium preceding penetration. In both cases, infection hyphae can be produced from appressoria. Som!!times these appressoria remain viable on the surface of the host for some time, but infection has not yet taken place. Penetration into the host occurs in various ways. In many cases, an infection hypha penetrates the host cuticle and then the outer epidermal cell wall. This can be the start of a parasitic relationship. However, some time may pass between penetration and the start of such a relationship. This stage is correctly referred to as a latent, dormant, or quiescent infection. The actual infection has taken place, though macroscopically not yet visible, but further growth of the infection hypha is delayed. Nothing is known about the relationship between host and parasite at this stage; there might be an equilibrium between these two. This implies that the term latency should be described as a quiescent or dormant parasitic rc;:lationship which, after a time, can change into an active one. The definition of a latent infection given above, first stated by Giiumann (32), is used in this paper, although I do not extend the definition, as Giiumann did, to those stages in the life cycle of a number of Usti/ago spp. during which no external

Disseminated Coccidioidomycosis Associated with Immunosuppressive Therapy Following Renal Transplantation

Renal homograft transplantation has become an accepted and relatively common therapeutic approach in chronic renal failure.1 This report is concerned with the development of disseminated coccidioidomycosis in a child receiving immunosuppressive therapy following renal homograft transplantation. It would appear that a subclinical, quiescent infection was activated by the administration of immunosuppressive agents. Case Report P.M., a Caucasian male, age 10 years at the time of his death, was first seen at the Children's Hospital of Pittsburgh at 6 years of age with evidence of advanced renal disease. A diagnosis of "chronic nephritis" had been made at age 2 years. Although a native of Pennsylvania, the child had resided in Phoenix, Arizona from his second through fifth year of life.

Brown rot of stone fruits on the Murrumbidgee Irrigation Areas. II. Aetiology of the disease in Trevatt apricot trees

Blossom blight is of economic importance in apricots on the Murrumbidgee Irrigation Areas (MIA), but fruit rot is not. Monilinia fructicola generally does not overwinter effectively in apricot trees in the MIA, the inocula for primary infections coming from nearby peach plantations. Blighted blossoms in apricot trees, which flower a week before peaches, may provide inoculum for blighting of flowers in the latter crop. In apricot trees, unlike peach, there is a continuous infection chain from flowering till harvest. Inoculum may pass from apricot to peach in December and January, thus bridging a gap in the infection chain in peach. The infection chain in apricot is described. Latent and quiescent infections were observed. The implications of the exchange of inoculum between peach and apricot are discussed.

Brown rot of stone fruits on the Murrumbidgee Irrigation Areas. I. Aetiology of the disease in canning peaches

In a typical season brown rot development in canning peaches on the Murrumbidgee Irrigation Areas was found to follow a basic pattern. There is little or no blossom blight or post-blossom infection. Infection of fruit is first seen in January and increases until harvest. Infections of fruit during the preharvest period are almost all initiated in injuries. Damage caused by larvae of the oriental fruit moth is the most important form of fruit injury. Infections of injured immature fruits may occur in dry weather and cannot be prevented by the application of fungicides. These injured rotting fruits produce inoculum which can start epiphytotics if rain falls when the fruit is ripe. Blighted blossoms are usually unimportant as inoculum sources at this stage, but they are important links in the infection chain since they can provide inoculum for the first infections of injured fruits. Dried fruit beetles were found to be vectors during the preharvest build-up of the disease, and there was some evidence that they may carry inoculum to blossoms in spring. Quiescent and latent fruit infections initiated in spring were noted, but they are thought to have little overall significance in the aetiology of the disease. Some infections occurring during the ripening period may exhibit latency. The implications of these findings for disease control and their relevance to brown rot aetiology in other, more humid fruit-growing areas are discussed.

The occurrence of a quiescent infection of stone fruits caused by Sclerotinia fructicola (wint.) Rehm.

An infection of immature peach and apricot fruits by Sclerotinia fructicola (Wint.) Rehm. is described. Since infection results in macroscopically visible lesions it is proposed that this type of infection be known as "quiescent" rather than latent. Symptoms have been induced in immature apricots by inoculation with conidia of the fungus and, after a period of quiescence, progressive rots developed from such infections as the fruit ripened. The fungus was re-isolated from surface-sterilized material bearing quiescent infections. Cultural evidence, together with field observations, indicate that a quiescent infection occurs naturally in the orchard, particularly in a season of moderate to severe blossom infection. Fruit losses during a dry harvest period are ascribed in the main to the activation of quiescent infections during fruit ripening. The histology of the lesion is described. The response of the host to infection is variable, but always includes a more or less extensive collapse and necrosis of the epidermis and of one or more layers of the hypodermis. Periderm formation may be associated with the necrogenic reaction. The results of a spray trial demonstrate that some measure of control of quiescent infection can be achieved by applying eradicant sprays during blossoming, and thus provide circumstantial evidence that a proportion of such infections can be established during this period. The quiescent infection is compared with other host-pathogen combinations in which infection is followed by a period of latency or quiescence, and suggestions are put forward as to the factors governing quiescence. The concept of "latent contamination" is re-evaluated in the light of the evidence presented in the present paper. It is argued that conidia alighting on the fruit surface during the growing period are more likely to give rise to a quiescent infection than to survive to produce an infection of the ripe fruit.

Activation of quiescent mucormycotic granulomata in rabbits by induction of acute alloxan diabetes.

In normal rabbits subcutaneous granulomata produced by the injection of a spore suspension of Rhizopus oryzae remained confined to the site of inoculation, showed no fungus proliferation, no longer yielded the agent on culture 10 weeks after inoculation, and eventually healed. Similar well established granulomata in rabbits with acute alloxan diabetes induced 8, 10, and 15 days after injection of the fungus uniformly showed activation of the infection. This occurred only in animals showing acetonuria. In these animals the skin lesions showed proliferation of the fungus frequently associated with invasion and early necrosis of the granuloma wall. In some instances, spread of the infection to adjacent tissues with invasion of blood vessels had occurred. These experiments illustrate that changes in host metabolism can activate a preexisting quiescent infection.

A medical survey in a gold coast village

1. 1. A medical survey, taking social conditions into account, was undertaken in a village of 255 inhabitants in the cocoa belt of the Gold Coast. 2. 2. Sanitary and housing conditions were better than the average for rural Africa, and there was no serious poverty. 3. 3. There was a high child mortality in the village and few people lived beyond 50 years. 4. 4. The heights and weights of the people were less than those of English people. Blood counts, and haemoglobin and haematocrit estimations, fell below the normal standards for England. 5. 5. The sickle-cell trait was present in 19·5 per cent. of males, and in 24·6 per cent. of females. 6. 6. The blood sedimentation rate was estimated in 69 people, and the test was considered to be of no diagnostic value. 7. 7. The spleen was enlarged in 45·5 per cent. of villagers, and malarial parasites were found in the bloods of 31·7 per cent. P. falciparum was the commonest parasite, but P. vivax and P. malariae were also present. 8. 8. Hookworm ova were found in the stools of 52 per cent. of people, Ascaris ova in 75·8 per cent., and T. trichittra ova in 3·3 per cent. Cysts of E. histolytica were rarely found. Urinary schistosomiasis ( S. haematobium) was present in 9·1 per cent. of the population. 9. 9. Microfilariae of D. streptocerca were present in the skins of 20·9 per cent. of the people, other filariae being entirely absent. 10. 10. Signs suggesting protein and vitamin deficiency were noted in mothers and in children. Enlargement of the liver, which was present in 33·3 per cent. of people, was thought to be due partly to malaria and partly to malnutrition. 11. 11. Seventy-five per cent. of the villagers showed evidence of active or quiescent yaws infection. Other diseases are briefly discussed. 12. 12. The normal African is not healthy by European standards, but is undersized, anaemic, and disease-ridden.

The Specificity of the Conjunctival Infection in Monkeys Following Inoculation with Trachomatous Tissue

While a number of investigators have observed a follicular hypertrophy of the conjunctiva of monkeys following inoculation with tissue from human trachomatous eyes, doubt has been frequently expressed as to the specificity of the infection. Objections have been made that the response thus induced in monkeys differs from human trachoma in the absence of corneal pannus and interfollicular infiltration, and in spontaneous recovery, without cicatrization. It must be admitted that these objections are tenable since the characteristics mentioned are the differential factors which make possible a separation of trachoma from spontaneous folliculosis of children and the indigenous folliculosis with which monkeys are frequently afflicted. It is for such reasons that some investigators believe that the reaction of monkeys following inoculation with human material or certain cultures is not trachoma, but spontaneous folliculosis which they consider as either the result of non-specific irritation or an exacerbation of a latent or quiescent indigenous infection. In support of the former hypothesis it is reported, for example,1 that follicles may appear after repeated chemical irritation of the human eye with atropine. This could not be demonstrated on monkeys by Olitsky, Knutti and Tyler,2 however. Wilson and Haig3 have reported the development of follicles in monkeys, which they interpreted as the spreading of an infection already present, after the conjunctiva was irritated lightly by mechanical means. However, Olitsky and Tyler4 have isolated from cases of folliculosis in monkeys an organism which, as they showed with Syverton,5 induces the infection upon inoculation into normal animals. They have been unable to obtain this organism from cases of human trachoma or from monkeys infected with human

Effect of benzyl benzoate on antibody formation in rabbit

In a previous article 1 on the effect of benzyl benzoate on the leukocytes of the rabbit, I stated that larger subcutaneous doses caused latent or quiescent infections to become active; also that changes occurred in the leukocytic picture which suggested that benzyl benzoate has a mildly depressant influence on the number and grouping of the leukocytes of rabbits. These results led me to think that benzyl benzoate may inhibit antibody formation, and I undertook to investigate this question as here recorded. By careful observation I tried to select animals free from infection. It was the intention to study the changes in the blood picture with the effects on antibody production at the same time. Since the blood picture is greatly influenced by the process of immunization as well as by the frequent bleeding, I refrain from recording the leukocytic curves at this time as they are misleading and in no way express the influence of benzyl benzoate when used as in the previous study. Neither are weight curves given as the weight was not influenced by either the immunization or the injection of benzyl benzoate. The antibody the formation of which I chose to study was the lysin for sheep corpuscles. Benzyl benzoate injections were given subcutaneously in sterile olive oil in doses and at times varying with each experiment. The hemolytic amboceptor was produced by injecting rabbits intravenously with 2, 3 and 4 c c. of a fresh SO^fc suspension of goat corpuscles, carefully washed in salt solution. The injections were given at 2 day intervals so that the actual process of immunization covered 7 days. In exper. 4, the third dose was increased to 5 c c. The intravenous immunization is relatively reliable, uniform, and advantageous on account of the brief period required to obtain a good response. The loss of animals from anaphylaxis was 3 of 14. The determination of the