Immunology and biochemistry of Hymenolepis diminuta.

This review is an account of modern research into the immunology and biochemistry of the rat tapeworm, Hymenolepis diminuta. The first half of the review is devoted to the immunological responses of the host to the parasite. It describes the specific responses that occur when the host is exposed to a primary infection, and the changes that occur when further infections are superimposed on the primary one. The aquisition of immunity to the tapeworm and its persistence in the absence of the infection are also discussed, as well as the non-specific responses of the host to the parasite. The second half of the review is concerned with biochemistry, summarizing the early biochemical work that has been carried out on the tapeworm and describing the metabolic pathways now thought to be characteristic of the parasite. What little information that exists on intermediary metabolism in eggs and larvae is summarized here. Much of this section is concerned with the role of mitochondria in H. diminuta, especially the control of the critical branchpoint (PK/PEPCK), which partitions carbon into either the cytosol or the mitochondrion. The role of 5-hydroxytryptamine in controlling both worm behaviour and metabolism is discussed, followed by a brief look at some other effectors that may prove in the future to have great significance in regulating the parasite. Finally, there is a detailed consideration of strain variation within H. diminuta and of the impact on the tapeworm of components of the immune system, formerly described as the 'crowding effect'. The review concludes with a brief discussion of evolutionary aspects of the rat-tapeworm relationship and a comprehensive bibliography.

Factors influencing the development and carbohydrate metabolism of Echinococcus granulosus in dogs.

Echinococcus granulosus adult worms, 35 days postinfection, were measured for dispersion in the intestines of 10 dogs, a range of morphological characters, and the excreted end products of carbohydrate catabolism following 4 hr incubation in vitro. Most worms were found in the proximal sections of the small intestine, but the pattern of dispersion differed between dogs. Worm development varied both between dogs and between different regions of the small intestine of individual dogs. Overall there was a high level of variability with no simple patterns. Worm metabolism was related to worm development and, also independently, to local population density within the intestine. Larger, more mature worms produced less lactate and, at higher densities, worms tended to produce more acetate and succinate (pathways with a higher energy yield than lactate) and less ethanol. Thus, both more developed worms and high population density are associated with a shift from cytosolic to mitochondrial metabolism. The variation between worm populations along the small intestine along with the observed variation between worm populations from sibling dogs infected with genetically identical parasites suggests that the local host environment has a significant effect on parasite development.

Dissociation between mossy fiber sprouting and rapid kindling with low-frequency stimulation of the amygdala.

In an attempt to determine whether sprouting of mossy fibers is invariably correlated with kindling of seizures, we subjected rats to rapid kindling with long trains of low-frequency stimulation of the amygdala that resulted in development of generalized seizures within a mean of five stimulations. For comparison, we subjected other rats to conventional kindling with short trains of high-frequency stimulation of the amygdala that resulted in development of generalized seizures within a mean of 13 stimulations. We found no evidence of mossy fiber sprouting in the dentate gyrus of rats killed one day after completion of rapid kindling, as compared to yoked controls, although significant sprouting was seen in rats killed one day after completion of conventional kindling. When we examined tissue from rats killed 20 days after rapid kindling, however, we did find significant sprouting, suggesting that mossy fiber sprouting can be triggered by rapid kindling if sufficient survival time is allowed. The observed disparity between completion of rapid low-frequency kindling and detection of mossy fiber sprouting suggests that mossy fiber sprouting may be associated more with sustained survival time after neuronal activation than with kindling per se. Furthermore, the similar time course of conventional kindling and of mossy fiber sprouting obscures the determination of a causal role of mossy fiber sprouting in conventional kindling.

Exercise for the low back pain patient.

As 90% of patients with acute LBP recover within a 2-month period, irrespective of the type of treatment received, exercise probably plays little role in facilitating recovery from an acute episode of LBP. It may be a very important factor in both symptomatic and functional recovery in chronic LBP, as well as an integral factor in preventing recurrent injury. The most efficacious exercise regimen for treating LBP is currently unknown. Similarly, little is known about the efficacy of individual exercises. In certain patients, flexion or extension exercises may be inappropriate. A careful history and physical examination, observing the movements that cause pain, will assist the physician in tailoring the exercise programme to the individual patient to achieve the greatest likelihood of success. Communication between the patient, physician and therapist is vital to allow continual adjustment of the programme to best meet the patient's needs. As improvement occurs, more stressful exercises can be added to improve strength, endurance and aerobic fitness. Individualizing the exercise programme to the patient's symptoms and communication between the patient, therapist and physician lead to greater compliance with the exercise programme and a greater likelihood of improved outcome.

Blood alcohol levels of patrons leaving licensed premises in Perth, Western Australia.

We aimed to determine the alcohol consumption, blood alcohol levels (BALs) and subsequent driving of patrons leaving 15 hotels and taverns in Perth, Western Australia. Of the 414 patrons approached by interviewers on Friday and Saturday evenings, 307 (74 per cent) consented to take part. Self-reported alcohol consumption, driving intentions, perceived levels of fitness to drive and demographic information were collected using an interviewer-administered questionnaire. Observations of subsequent driving were recorded and BALs were measured by breath-alcohol meter. The patrons surveyed were predominantly male (76 per cent) and aged between 18 and 35 (87 per cent). Average reported alcohol consumption was 7.6 standard drinks for males and 4.9 drinks for females, around double the daily amount recommended by the National Health and Medical Research Council. Further, 23 per cent of the sample had consumed more than 10 drinks (male) and 6 drinks (female). With respect to BALs, 37 per cent of patrons exceeded the drink-drive limit then in force of 0.087 and 56 per cent exceeded 0.05. Of greater concern, 23 per cent who were over the 0.08 legal limit were subsequently observed to drive even though they had been informed of their BAL and legal status with respect to driving. The results suggest that most young patrons drinking in Perth metropolitan hotels and taverns consume alcohol on such occasions in excess of limits currently recommended by health authorities and attain blood alcohol levels dangerous for driving. This is likely to remain unchanged without public debate as to the responsibility of licensees in serving a potentially harmful psychotropic drug and effective enforcement of liquor licensing laws.

Alcohol and murine acquired immunodeficiency syndrome suppression of resistance to Cryptosporidium parvum infection during modulation of cytokine production.

The effects of inoculation of LP-BM5 murine leukemia retrovirus and chronic ethanol (5% v/v) ingestion on immunomodulation and Cryptosporidium parvum infection in C57BL/6 female mice were evaluated. The intestinal mucosae of retrovirally immunosuppressed animals were heavily colonized by Cryptosporidium parasites, and oocysts shedding in the feces persisted throughout the duration of the study. Mortality was exacerbated by murine retrovirus infection alone and exacerbated with concomitant chronic alcohol feeding (42.8 and 69.4%). Chronic ethanol ingestion decreased production of interferon-gamma and soluble interleukin-2 receptor released in supernatants of splenocytes when stimulated with concanavalin A, compared with the control group. Decreased production of interferon-gamma and interleukin-2 receptor was further exacerbated due to retrovirus infection. Tumor necrosis factor production by splenocytes stimulated with lipopolysaccharide, however, was significantly increased because of retrovirus infection. LP-BM5 retrovirus infection alone as well as with concomitant ethanol feeding altered cytokine production, which might have led to immunodeficiency. These changes may help explain the enhanced persistence of Cryptosporidiosis.

Enhancement of resistance to Cryptosporidium parvum by pooled bovine colostrum during murine retroviral infection.

The therapeutic efficacy of pooled bovine colostrum for the control of cryptosporidiosis was investigated during murine acquired immunodeficiency syndrome in female C57Bl/6 mice. Mice were infected with LP-BM5 murine leukemia retrovirus for four months and then inoculated with Cryptosporidium parvum oocysts. Persistent cryptosporidiosis was established in all retrovirus immunosuppressed mice, while control mice were refractory to infection. Parasite colonization of intestinal villi was significantly (P < 0.05) reduced in immunosuppressed animals that received dietary supplemental pooled bovine colostrum compared with to those that did not receive colostrum treatment. Similarly, shedding of oocysts in the feces of immunosuppressed animals that received dietary pooled bovine colostrum was significantly (P < 0.05) reduced compared with those that did not at 26 days post-parasite challenge. Since the nonimmune bovine colostrum contained no anti-Cryptosporidium antibodies, this suggests that passively transferred antibodies alone are unlikely to have provided the improved resistance shown in this study.

Suppression by dietary alcohol of resistance to Cryptosporidium during murine acquired immune deficiency syndrome.

Significant immunological changes occur following LP-BM5 murine leukemia retrovirus infection as well as chronic alcohol consumption. Retrovirus infection which has proceeded to murine AIDS permitted persistent Cryptosporidium infection, while non-retrovirus infected mice were resistant. Dietary alcohol provided until the day before parasite challenge did not affect resistance in controls, but increased the numbers of oocysts in the feces of retrovirus suppressed mice. Mortality was significant in retrovirus infected mice, and exacerbated slightly by dietary ethanol, while all controls survived parasite challenge. The retrovirus infected mice had greatly reduced numbers of intestinal CD4+ T helper cells and IgA+ B cells, which may explain their loss of intestinal resistance. Clearly, the severely immunosuppressed animals with murine AIDS were more sensitive to alcohol consumption than uninfected controls. This suggests that alcohol can synergize with murine retrovirus infection to exacerbate loss of resistance to an opportunistic pathogen common in human AIDS patients.

Effect of levamisole on parenteral vaccines for swine dysentery.

Leucocyte migration-inhibition and humoral antibody responses (HAR) were demonstrated in swine immunized with particulate or soluble antigen of Treponema hyodysenteriae. Levamisole (at the recommended deworming level), given simultaneously with particulate vaccine did not significantly (P greater than 0.05) enhance nor suppress the leucocyte migration-inhibition response. However, an enhancing leucocyte migration-inhibition of the drug was seen in pigs given soluble vaccine in combination with levamisole compared with those receiving soluble antigen alone. Levamisole generally suppressed the HAR throughout the immunization schedule of pigs given soluble or particulate vaccine. There was no significant suppression (P greater than 0.05) of clinical signs of swine dysentery (SD) in animals given particulate vaccine nor in those receiving this vaccine plus levamisole. However, pigs receiving soluble vaccine plus levamisole had fewer clinical signs of SD as well as significantly (P less than 0.05) fewer shedding episodes of T. hyodysenteriae than those given soluble antigen alone. When compared with the control pigs, swine vaccinated with soluble antigen had fewer days of total diarrhoea and shedding episodes of T. hyodysenteriae. However, the diarrhoea of vaccinated pigs was not significantly (P greater than 0.05) delayed when compared to the unvaccinated swine.

Effect of acupuncture on young pigs with induced enteropathogenic Escherichia coli diarrhea.

Thirty-four preweaning pigs with induced enteropathogenic Escherichia coli diarrhea were treated with electroacupuncture, traditional acupuncture, or neomycin. In the group treated with electroacupuncture, points GV-1, bilateral ST-36, and Bai-hui were stimulated electrically. In the group treated with traditional acupuncture, points GV-1, bilateral ST-36, BL-20, bulb points, bilateral ear tip, and Shan-gen were used. Acupuncture points CV-12 and bilateral ST-25 also were treated with moxibustion (applying heat generated by a burning herb, Artemisia argyi). Hemoacupuncture also was applied to Shan-gen, bilateral ear tip, and bulb points. Pigs in the third group were given neomycin orally. Five pigs were inoculated with E coli, but were not treated and served as nontreated controls. At postinoculation day 5, 60% of control pigs and greater than 80% of pigs in treated groups recovered from diarrhea. However, at postinoculation day 3, recovery rates for pigs in the control and group treated with electroacupuncture were only 20 and 27.3%, respectively; whereas pigs treated with acupuncture or neomycin attained 81.8 and 71.4% of recovery rates, respectively. Seemingly, traditional acupuncture, but not electroacupuncture, was effective in controlling induced E coli diarrhea in pigs at its early stage.

Effect of levamisole on the clinical and immunologic responses to oral vaccine of Treponema hyodysenteriae.

Conventionally raised crossbred Hampshire pigs were vaccinated orally with attenuated Treponema hyodysenteriae in combination with an anthelmintic, levamisole or dichlorvos. Pigs in group I (n = 9) were treated with levamisole and vaccinated with attenuated T hyodysenteriae and those in group II (n = 9) were treated with levamisole and permitted to commingle (contact exposure) with group I. Pigs in group III (n = 9) were vaccinated in a similar manner and were treated with dichlorvos. Pigs in group IV (n = 9) were treated with dichlorvos and permitted to commingle with group III. Control pigs (group V; n = 9) were not given any anthelmintic, nor were they vaccinated; they were housed separately. During the 8-week interval between vaccination and challenge inoculation, 4 total days and 8 total days of diarrhea were observed in pigs in groups I and II, respectively. Likewise, 5 total days and 10 total days of diarrhea were seen in groups III and IV, respectively. In all groups, the pigs tended to shed the organism in their feces after they were vaccinated or challenge inoculated, as determined by a fluorescent antibody technique (FAT) and culture procedure (CP). Overall mean shedding patterns of 5.5% and 24.5% identified by CP and FAT, respectively, were seen in the 2 levamisole-treated groups (I and II). In contrast, mean shedding patterns of 4% and 18% of the isolation attempts were detected by CP and FAT, respectively, in the 2 dichlorvos-treated groups. Diarrhea and shedding of T hyodysenteriae in the controls (group V) did not occur.(ABSTRACT TRUNCATED AT 250 WORDS)

Lymphocyte stimulation in swine dysentery.

In lymphocyte stimulation studies of pigs affected with swine dysentery (SD) all of the pigs gave significant response (P less than 0.05) to soluble antigen from Treponema hyodysenteriae. Swine infected with virulent or attenuated T. hyodysenteriae gave significant lymphocytic response 3 or 6 weeks after infection; uninfected pigs did not give a similar lymphocytic response. The delayed hypersensitivity (DH) skin test, in which soluble T. hyodysenteriae antigen preparation was used, detected only 3 out of 14 SD-affected swine. The lymphocyte stimulation assay by detection of protein synthesis may offer a rapid, reliable test for the diagnosis of SD within herds suspected of being affected.

Application of a leukocyte migration-inhibition agarose test to swine dysentery.

Cell-mediated immunity (CMI) was demonstrated in swine naturally affected with swine dysentery (SD) by a leukocyte migration-inhibition agarose test (LMAT). Migration of leukocytes from SD-affected pigs was inhibited in the presence of soluble antigen of Treponema hyodysenteriae, whereas migration of leukocytes from noninfected swine was not inhibited by exposure to the same antigen. Cell-mediated immunity was detected initially after the appearance of clinical signs of the disease, and a peak migration index (MI) of 0.11 (P less than 0.01) was detected at 2 weeks thereafter. The MI gradually decreased over the remaining 3 weeks of the experiment. Humoral antibody correlated well with CMI, since both showed maximum production within the same time interval. Leukocytes of swine naturally affected with SD 4 months previously had a significant MI response of 0.73 (P less than 0.05), whereas uninfected swine of comparable age and weight showed a MI of 0.94 that was not significant (P less than 0.05). The results indicated that the LMAT may be useful for the diagnosis of SD.

Survey of leptospiral agglutinins in the sera of swine of southeastern Alabama.

The occurrence of leptospirosis in swine of southeastern Alabama was determined. A total of 627 sera were tested, using the microscopic agglutination method, with live antigens of 12 serovars. Of the sera tested, 121 (19.3%) had a titer of 1:100 or greater to the serovars employed. The percentage distribution of sera with titers of greater than or equal to 1:100 among serovars most commonly reported was as follows: Leptospira interrogans serovars pomona, 3.8%; icterohaemorrhagiae, 3.3%; canicola, 1.6%; hardjo, 0.7%; and grippotyphosa, 0.16%. Of the less commonly recognized leptospiral serovars, the percentages reacting were as follows: ballum, 4.9%; autumnalis, 3.2%; pyrogenes, 1.1%; and bataviae, 0.4%. None of the sera reacted with antigen of serovars australis, tarassovi, or wolffi.

Immunity to Lancefield's group E Streptococcus: passive protection of swine.

Healthy swine from one source were randomly allotted to 3 groups of 3 pigs each. Troup I and II pigs were parenterally dosed with serum obtained from swine in the convalescent stage of streptococcic lymphadenitis of swine. Group III pigs were contact controls. The swine of all groups were orally exposed to Lancefield's group E Streptococcus sp. During the next 3 weeks, the controls evidenced little resistance to the development of streptococcic lymphadenitis of swine, whereas the principals evidenced considerable resistance to development of the disease.

An agglutination test for the detection of Bordetella bronchiseptica infection in swine.

An agglutination test with the use of formalin-killed antigen of the cell carrying the capsule was developed and used for the detection of antibody in swine naturally infected with Bordetella bronchiseptica. Under optimum antigen concentration and reaction temperature 210 or 60% of 342 serum samples tested from 42 conventional swine herds were positive for Bordetella infection. In contrast, only 34 or 10% of 342 nasal swabs from the same animals were positive for Bordetella by culture technique. The test was relatively free of cross-reactivity to related organism. However, 2.7 and 13.0% of sera from growing pigs and mature hogs, respectively, reacted with antigen of Pasteurella multocida. Because of this, only agglutinin reactions in 1:20 dilutions or higher to Bordetella were considered positive. The bulk of the antibody activity of selected sera tested from various age ranges of swine was mercaptoethanol sensitive, suggesting that serum antibody in Bordetella infection may be associated with immunoglobulin IgM. Because of the high agglutinability and stability of formalin-killed antigen the test may be useful as an auxiliary aid for the diagnosis of Bordetella infection where the organism cannot be identified by culture means.

Immunity to Lancefield's group E. streptococcus: flank inoculation of susceptible and immune swine.

Healthy swine flank inoculated with Lancefield's group E Streptococcus sp developed characteristic signs of streptococcal lymphadenitis of swine; however, abscesses were found in prefemoral lymph nodes rather than in cervical lymph nodes. After 6 months, swine (recovered from the cervical form of streptococcal lymphadenitis of swine caused by oral exposure to group E Streptococcus) were flank inoculated with group E Streptococcus sp. Only transitory signs of diseases developed and abscesses did not develop in the prefemoral lymph nodes.