Babesia major: protection of intact calves against homologous challenge by the injection of irradiated piroplasms.

Blood from a splenectomized calf infected with Babesia major was divided into 20 ml aliquots which were γ-irradiated at doses of 0, 23.3, 27.3, 31.4, 35.4 and 39.5 krad and then inoculated into groups of three intact calves. Animals receiving non-irradiated blood had typical mild B. major reactions, but those receiving blood irradiated at 23.3, 27.3 and 31.4 krad and 2 of 3 receiving blood irradiated at 35.4 krad had minimal reactions. The remaining 4 animals had no detectable parasitaemic reactions. When the calves were challenged with a similar number (6.0 × 10⁹) of homologous parasites, they were all immune with the exception of the 4 animals which had not reacted initially. The immune status of individual cattle was reflected accurately in the results of the micro-ELISA test, which detected a significant rise in serum antibody titre of the 4 susceptible animals 7 days after challenge.     

Ostertagia ostertagi: protective immunity in calves. The development in calves of a protective immunity to infection with Ostertagia ostertagi

Resistance to the establishment of Ostertagia ostertagi was tested in calves which had been infected daily with 1000 larvae for 30, 80, 150, and 250 days. The proportion of a challenge dose of 30,000 larvae which became established decreased steadily and by Day 250 was only $\text{1}\text{20}$ of the proportion that became established in susceptible control animals. Neither the age of the host nor the age of the larvae used affected the proportion that became established. It is shown that the increasing resistance to the establishment of worms, and an average life span of 28 days, of worms which developed beyond the early fourth stage, adequately account for the course of infections in calves infected daily. Evidence is presented which suggests that the host's previous experience of infection increases the proportion of the worms that are inhibited in their development.     

Babesia argentina: Disseminated intravascular coagulation in acute infections in splenectomized calves

The pathology of severe Babesia argentina infections in splenectomized calves was studied. The calves were infected by intravenous inoculation of 10⁹–10¹⁰B. argentina and given 0.1 mg/kg betamethasone to enhance the parasitemia. Hematological changes observed during detailed studies of the course of infection in eight calves, three of which subsequently died, included thrombocytopenia, leucopenia, and reduced fibrinogen levels. The prothrombin time and partial thromboplastin time were prolonged in all three calves tested, and pathological levels of fibrinogen degradation products were detected in both of two calves tested. Massive pulmonary edema was a constant finding at autopsy of 24 fatal cases. Histopathological examination revealed widespread fibrin thrombi in capillaries and larger vessels of lung, in capillaries of renal glomeruli, and in hepatic sinusoids. The findings established the occurrence of disseminated intravascular coagulation in the acute infections studied.     

Saguinus geoffroyi as a host for Plasmodium vivax

A monkey-adapted strain of Plasmodium vivax (Achiote) was transferred by trophozoites through 11 serial passages in Saguinus geoffroyi (Titi marmoset). Patent infections developed in both normal (23 of 24) and splenectomized (8 of 9) marmosets. The infections in the altered animals were of greater severity than in the intact subjects as indicated by patent periods ($\text{x}\text{?}\text{= 87}\text{vs}\text{61}\text{days}$) and maximum parasitemias ($\text{x}\text{?}\text{= 35,018}\text{vs}\text{16,218}\text{per mm}{}^3$).Relapses were recorded in 13 of 14 unaltered and 4 of 4 splenectomized animals that survived the primary attack. As evidence for acquired immunity, the mean maximum parasitemias during relapse in the normal animals were $\text{1}\text{8}$ of the values during the primary attack; patent periods were shorter than those in the initial infection. There was also some indication of an acquired immunity in the splenectomized group of animals. However, one splenectomized marmoset experienced a patent period of 325 days during the first relapse.There was considerable variation of infection parameters among the animals in each group.     

Nippostrongylus brasiliensis: mast cells and histamine levels in tissues of infected and normal rats.

The role of the spleen during Babesia microti and B. hylomysci infection was investigated by examining the course of infection in both intact and splenectomized mice. The presence of the spleen was critical during the early stages of infection to control excessive multiplication of either parasite, a role taken over by other lymphoid sites as the infection progressed. Mice splenectomized prior to or within 1 week of B. microti inoculation developed extended infections with some deaths, and others were unable to check their parasitemias. All intact mice, and those splenectomized 1 week after infection with B. microti, recovered completely with subsequent development of sterile immunity. Mice splenectomized prior to or within 1 week of B. hylomysci inoculation succumbed to hyperacute infections: Some of the intact mice, and those splenectomized 12 days after infection, recovered but continued to harbor a low-grade infection with periodical recrudescences. Erythrophagocytosis of infected and uninfected erythrocytes was detected in saline preparations and impression smears of spleen and bone marrow and rarely in blood smears of infected mice. This coincided with anemia, splenomegaly, and relatively high levels of opsonizing antibodies, especially during B. microti infection. The colloidal carbon clearance method was used to investigate the phagocytic activity of the reticuloendothelial system. Carbon clearance rates increased rapidly during both infections, but peak B. hylomysci parasitemia coincided with reticuloendothelial phagocytic depression and death of the host. Babesia microti stimulated a consistently higher reticuloendothelial phagocytic activity with higher erythrophagocytosis both in the spleen and bone marrow than did B. hylomysci.     

Uterine infections in the postpartum cow: II. Possible synergistic effect of Fusobacteriumnecrophorum and Corynebacteriumpyogenes

Clinical conditions, which were observed in primiparous Angus and Hereford heifers with postpartum uterine infections are reported. Forty-three of sixty-four cows (67%) had uterine infections. $\text{Corynebacterium}$$\text{pyogenes}$ and $\text{Fusobacterium}$$\text{necrophorum}$ were the most frequently isolated aerobe and anaerobe, respectively. Twelve of the sixty-four cows (18.8%) had infections that involved these species. Three of these twelve cows were infected only with $\text{C.}$$\text{pyogenes}$, two were infected only with $\text{F.}$$\text{necrophorum}$, and seven were infected with both organisms. All five of the cows which were infected with either $\text{C.}$$\text{pyogenes}$ or $\text{F.}$$\text{necrophorum}$ showed signs of estrus and four of the five cows conceived by 110 days postpartum. The single cow that did not conceive was infected with $\text{C.}$$\text{pyogenes}$. Three of the seven cows which were infected with both organisms showed signs of estrus and none of the seven cows conceived by 110 days postpartum. In addition, when only $\text{C.}$$\text{pyogenes}$ or $\text{F.}$$\text{necrophorum}$ was isolated from the uterus, cows had either mild or no clinical signs of infection. In contrast, the seven cows which were infected with both organisms had severe clinical signs of infection that included excessive vulvar discharge, uterine abscesses and pelvic adhesions. These observations suggested that a pathogenic synergism between $\text{C.}$$\text{pyogenes}$ and $\text{F.}$$\text{necrophorum}$ might have caused the increased severity of postpartum uterine infections, and the subsequent detrimental effect on return to estrus and conception.     

Babesia bovis: Proteins of virulent and avirulent parasites passaged through ticks and splenectomized or intact calves

Passage of the avirulent vaccine (K) strain of Babesia bovis (K_A) through either Boophilus microplus ticks, intact calves, or intact calves and then ticks, resulted in two distinct protein and protein antigen profiles as analyzed by two-dimensional gel electrophoresis of biosynthetically labeled proteins and immunoprecipitates. Different degrees of expression of two major acidic antigens of K_A designated Ka₁ (M_r 47,500) and Ka₂ (M_r 43,000) were observed. Ka₁ was apparently lost following passage of K_AB. bovis through intact calves but was strongly represented in the parasite population following a single tick passage. In contrast, passage through ticks of the virulent K_VB. bovis (from which K_A was derived by passage in splenectomized calves) did not lead to strong representation of the Ka₁ protein although there was increased representation of another major acidic protein antigen, designated Kv (M_r 35,000). These data suggest that the previously recognized reversion to a strain-dependent basal antigenic type in the tick vector depends also on intrastrain characteristics such as virulence and strain heterogeneity. The data suggest that K_A is a more heterogeneous population than K_V although cloned isolates are required to establish this point. Comparable syringe passage of another strain of B. bovis, designated C strain, through splenectomized calves resulted in less marked differences between the putative C_A and C_VB. bovis. This may explain the less stable avirulence of C_A compared to K_AB. bovis. Various selection pressures must act, in either the tick or the vertebrate host, on subpopulations in heterogeneous isolates to produce the changes described in protein antigen profiles of B. bovis. The possible relevance of changes in representation of proteins to biological characteristics of B. bovis (such as virulence and tick transmissibility) is discussed.     

Human babesiosis in ireland: Further observations and the medical significance of this infection

Three splenectomized persons in Yugoslavia, California, and Ireland have been reported to be infected by three different Babesia species; two cases were fatal. In a study of the site where the fatal infection was contracted in Ireland, blood samples from 36 persons who had recently been bitten by ticks were inoculated into two splenectomized calves; no response to Babesia divergens was detected. Field-collected Ixodes ricinus ticks inoculated into another splenectomized calf resulted in fever and recovery of the agent of tick-borne fever (Cytoecetes phagocytophilia). This attempt to determine the presence of latent infection in human beings with intact spleens should be repeated on a larger scale in areas with a demonstrably high incidence of Babesia in ticks and animals. Few places in the world are free of piroplasms; their presence may present a hazard to splenectomized persons or to those whose splenic function is deficient.     

Transport of arginine by an in vitro system

Cell surface glycoproteins of $\text{Neurospora crassa}$ conidia have been shown to bind amino acids and to be genetically associated with the previously defined amino acid transport systems of that organism. L-arginine does not readily permeate a film of $\text{Neurospora}$ conidial lipids. Addition of glycoprotein extracts from $\text{Neurospora}$ to the lipid film enhances permeation of arginine at an initial rate 1000 times the rate of permeation through lipid alone. The initial rate of passage exceeds the rate of unhindered passage (no lipid film) through the same cross sectional area by 10 fold.     

Uterine infections in the postpartum cow: I. Effect of dietary crude protein restriction

The relationship between adequate (0.96 kg per head daily) and deficient (0.32 kg per head daily) intake of crude protein between 150 days prepartum and 110 days postpartum and the incidence of postpartum infections in the bovine uterus was studied. The incidence of infection at 25 days postpartum was 52.2% and 48.1% (P > .10) for cows in the protein adequate and protein deficient groups, respectively. However, at 40 days postpartum, 21.7% of cows in the protein adequate group had infections $\text{vs}$ 51.9% (P < .05) of cows in the protein deficient group. In addition, the incidence of infection within the protein adequate group between sampling times was different (P < .10); whereas, the incidence within the protein deficient group between sampling times was not different (P > .10). Eighty-three bacterial isolates representing 27 species were recovered from the total of 100 samples. $\text{Corynebacterium}$$\text{pyogenes}$ and $\text{Fusobacterium}$$\text{necrophorum}$ were the most frequently isolated aerobe and anaerobe, respectively. Although there was no difference between diets (P > .10), these two organisms occurred most frequently in cows on the protein deficient diet and were associated with clinically severe uterine infections. These data suggest that the amount of crude protein in the diet affects both the incidence and duration of postpartum infections in the bovine uterus.     

Effect of splenectomy on the induction of high degrees of tolerance to skin allografts in rats

The effect of splenectomy on the induction of neonatal tolerance to histocompatibility antigens was studied. Newborn BN ($\text{Ag-B}{}^3\text{Ag-B}{}^3$) rats were splenectomized or sham splenectomized prior to transfer of a tolerance-inducing inoculum of Lewis/BN ($\text{Ag-B}{}^1\text{Ag-B}{}^3$) bone marrow cells. Twenty-two percent of the splenectomized animals were found to be highly tolerant of subsequent Lewis skin allografts, compared to 53.8% of the shamsplenectomized group. In addition seven of eight incompletely splenectomized animals were found to be highly tolerant. The relevance of these data to currently postulated mechanisms of classical neonatal tolerance induction is discussed.     

Plasmodium berghei: Thyroid hyperplasia and thyroid hyperactivity in mice

Statistically significant (P < 0.05) thyroid hyperactivity (¹³¹I% uptakes) occurs on certain days in Plasmodium berghei infected C3H mice. Male mice thyroid glands are made more hyperactive by the malaria than the female glands. Hyperactive thyroid glands may be at least one cause of hypocholesterolemia in plasmodium-infected rodents. Thyroid hyperplasia was found only in experimental mice ($\text{6}\text{20}$ males; $\text{8}\text{20}$ females). A hyperactive thyroid gland appears to be an unreported aspect of experimental acute P. berghei infections in mice. The hyperthyroidism may be due to possible toxic substances acting either directly on the thyroid gland, or indirectly on the hypothalamus affecting TSH production.     

Leishmania mexicana and Leishmania tropica major: Adoptive transfer of immunity in mice

The transfer of lymphocytes from NIH mice infected with Leishmania tropica major to nonimmune syngeneic mice, which had received 600 rad irradiation, markedly altered the course of subsequent Leishmania mexicana and L.t. major infections in these animals, when compared with infections in irradiated mice reconstituted with lymphocytes from uninfected animals. Some resistance to L. mexicana could be transferred with unfractionated lymphocytes, mixed nylon wool adherent, and nonadherent lymphocytes and to a lesser extent by nylon wool nonadherent cells alone but not by the adherent population. When the recipients of “immune” lymphocytes were infected with L.t. major the resulting lesions were either small and did not ulcerate, or grew rapidly, ulcerated, and healed. The course of L.t. major in the recipients depended on whether the donor of “immune” lymphocytes had a healed or a healing lesion. Immunity to L.t. major was largely associated with the nylon wool nonadherent population.     

Chemoprophylaxis with tetracycline drugs in the immunisation of cattle against Theileria annulata infection

Gill B.S., Bhattacharyulu Y., Kaur D. and Singh A. 1978. Chemoprophylaxis with tetracycline drugs in the immunisation of cattle against Theileria annulata infection. International Journal for Parasitology8: 467–469. Three-month-old fully susceptible cross-bred calves were immunised against tropical theileriosis by treating 2-tick or 5-tick stabilate-induced Theileria annulata infections, with 1 or 2 doses of long-acting oxytetracycline (Pfizer) at 20 mg/kg body weight injected subcutaneously, or chlortetracycline at 16 mg/kg body weight daily for 8 days given orally. The treatment began on the day of the infection. After 45 days, the recovered calves were given severe 10-tick homologous stabilate challenge.The reactions were evaluated by noting fever, degree of anaemia, severity of the swelling of the regional lymph node, rate of parasitization of lymphocytes in the lymph node, and of erythrocytes in the peripheral circulation.The untreated calves developed a severe form of the disease with typical symptoms, which killed 1 of 4 and 2 of 5 calves receiving 2-tick and 5-tick stabilates, respectively. A total of 30 treated calves reacted mildly or not at all. Both the treated and untreated, recovered calves resisted completely the challenge infection which killed 3 of 4 susceptible controls. The effect of 1 dose of long-acting oxytetracycline was equal to that of 8 daily treatments with chlortetracycline; 2 doses of the oxytetracycline suppressed almost all clinical responses at immunisation.     

Heterologous interchange and nondisjunction of distributively paired chromosomes in Drosophila melanogaster mature oocytes

In the mature oocyte C(1)-4 and Y-4 interchanges do not direct disjunction of the centromeres of the involved heterologs. C(1)-4 detachments are recovered in either sex and almost every time ($\text{13}\text{14}$) with a free fourth chromosome that is the sister of the involved four. Y-4 fragments are recovered preferentially in males ($\text{28}\text{28}$) and with a free, sister four ($\text{26}\text{28}$). In the mature oocyte segregation patterns are determined and C(1)-4 and Y-4 interchange usually involve heterologs segragating to the same pole.     

Efficient Capture of Infected Neutrophils by Dendritic Cells in the Skin Inhibits the Early Anti-Leishmania Response

Neutrophils and dendritic cells (DCs) converge at localized sites of acute inflammation in the skin following pathogen deposition by the bites of arthropod vectors or by needle injection. Prior studies in mice have shown that neutrophils are the predominant recruited and infected cells during the earliest stage of Leishmania major infection in the skin, and that neutrophil depletion promotes host resistance to sand fly transmitted infection. How the massive influx of neutrophils aimed at wound repair and sterilization might modulate the function of DCs in the skin has not been previously addressed. The infected neutrophils recovered from the skin expressed elevated apoptotic markers compared to uninfected neutrophils, and were preferentially captured by dermal DCs when injected back into the mouse ear dermis. Following challenge with L. major directly, the majority of the infected DCs recovered from the skin at 24 hr stained positive for neutrophil markers, indicating that they acquired their parasites via uptake of infected neutrophils. When infected, dermal DCs were recovered from neutrophil depleted mice, their expression of activation markers was markedly enhanced, as was their capacity to present Leishmania antigens ex vivo. Neutrophil depletion also enhanced the priming of L. major specific CD4⁺ T cells in vivo. The findings suggest that following their rapid uptake by neutrophils in the skin, L. major exploits the immunosuppressive effects associated with the apoptotic cell clearance function of DCs to inhibit the development of acquired resistance until the acute neutrophilic response is resolved.     

Lymphocyte function in experimental African trypanosomiasis. IV. Immunosuppression and suppressor cells in the athymic nu/nu mouse

The role of T cells in the development and expression of antigen-nonspecific immunosuppression in experimental African trypanosomiasis was addressed. Nude ($\text{nu}\text{nu}$) C57BL/ 6 NIH mice and their thymus-bearing ($\text{nu}\text{+}$) littermates were infected with Trypanosoma rhodesiense and examined for suppression of splenic B-cell responses in vitro to the mitogen LPS. All animals developed splenic unresponsiveness to LPS. Further, both nu/nu and nu/ + infected mice displayed suppressor cell activity in their spleen cell populations upon transfer to normal uninfected mouse spleen cell cultures. On the basis of these findings we suggest that both the generalized immunosuppression and the development of suppressor cell activity in the spleens of mice infected with T. rhodesiense are T-independent processes.     

Babesia bigemina,Babesia argentina, and Anaplasma marginale: Coinfectious immunity in bovines

Forty-eight intact and eight splenectomized cattle were used to evaluate different systems of coinfectious immunization against Babesia bigemina, Babesia argentina, and Anaplasma marginale. Coinfectious immunity was induced by two methods: (1) blood of cattle acutely infected with B. bigemina, B. argentina and A. marginale was used as the source of inoculum and the post vaccination reactions were chemotherapeutically controlled with Imidocarb, Ganaseg, Gloxazone, and Liquamycin, and (2) by artificially inducing babesiosis with the blood of carrier cattle with chronic infections of B. bigemina and B. argentina without chemotherapy. The degree of resistance was determined by bloodborne and tick-borne challenges. Ticks were collected from cattle and identified as Boophilus microplus and Dermacentor nitens. Vaccinated cattle demonstrated a high degree of resistance to babesiosis and anaplasmosis; however, cattle without coinfectious immunity were treated chemotherapeutically to prevent death losses.     

Rapid and intensive conversion of 5α-androstane-3α,17β-diol into 5α-dihyorotestosterone in the male rat anterior pituitary: in vivo and in vitro studies

The $\text{in vivo}$ and $\text{in vitro}$ metabolism of $\text{(}{}^3\text{H}\text{)-5α-}\text{androstane}\text{-α, 17β-}\text{diol}$ by the male rat anterior pituitary was studied. A rapid and intensive conversion of 5α-androstane-3α,17β-diol into 5α-dihydrotestosterone was demonstrated, since following a 30 min. incubation time, 73 % of the recovered radioactivity were constituted by 5α-dihydrotestosterone. Studies on the subcellular distribution of steroids showed that 5α-dihydrotestosterone was the main steroid recovered except from the 105,000 × g pellet. From $\text{in vivo}$ and $\text{in vitro}$ experiments it was concluded that the transformation of 5α-dihydrotestosterone into 5α-androstane-3α,17β-diol was a reversible process, and that this last steroid could exert its biological action mainly $\text{via}$ 5α-dihydrotestosterone.