Serological evaluation of Mycobacterium ulcerans antigens identified by comparative genomics

A specific and sensitive serodiagnostic test for Mycobacterium ulcerans infection would greatly assist the diagnosis of Buruli ulcer and would also facilitate seroepidemiological surveys. By comparative genomics, we identified 45 potential M. ulcerans specific proteins, of which we were able to express and purify 33 in E. coli. Sera from 30 confirmed Buruli ulcer patients, 24 healthy controls from the same endemic region and 30 healthy controls from a non-endemic region in Benin were screened for antibody responses to these specific proteins by ELISA. Serum IgG responses of Buruli ulcer patients were highly variable, however, seven proteins (MUP045, MUP057, MUL_0513, Hsp65, and the polyketide synthase domains ER, AT propionate, and KR A) showed a significant difference between patient and non-endemic control antibody responses. However, when sera from the healthy control subjects living in the same Buruli ulcer endemic area as the patients were examined, none of the proteins were able to discriminate between these two groups. Nevertheless, six of the seven proteins showed an ability to distinguish people living in an endemic area from those in a non-endemic area with an average sensitivity of 69% and specificity of 88%, suggesting exposure to M. ulcerans. Further validation of these six proteins is now underway to assess their suitability for use in Buruli ulcer seroepidemiological studies. Such studies are urgently needed to assist efforts to uncover environmental reservoirs and understand transmission pathways of the M. ulcerans.     

Secretion of oxytocin and progesterone by ovine corpora lutea in vitro

The mechanisms involved in the control of oxytocin and progesterone secretion by the ovine corpus luteum have been investigated in vitro using luteal slice incubations. Oxytocin and progesterone were secreted at constant rates from luteal slices for 2 h of incubation (366 +/- 60 pg X mg X h and 18.9 +/- 0.18 ng X mg X h, respectively). Secretion of progesterone, but not of oxytocin, was significantly (p less than 0.02) stimulated in the presence of ovine luteinizing hormone. Incubation of luteal slices in medium containing 100 mM potassium, however, resulted in increased secretion of oxytocin and, to a lesser extent, of progesterone (294 +/- 59% and 142 +/- 15%, respectively, p less than 0.05). Basal oxytocin secretion was reduced during incubation in calcium-free medium, compared to secretion in the presence of calcium (70 +/- 15 and 175 +/- 25 pg X mg X 20 min, respectively, p less than 0.01), whereas progesterone secretion was not altered in the absence of calcium. Secretion of both hormones by luteal slices was stimulated by the addition of the calcium ionophore A23187 (p less than 0.05). Addition of prostaglandin F2 alpha (2.8 microM) had no effect on secretion of either oxytocin or progesterone. We have demonstrated that oxytocin and progesterone can be stimulated, independently, from corpus luteum slices incubated in vitro. The pattern of release is consistent with the proposal that oxytocin, but not progesterone, is associated with and actively released from luteal secretory granules. Our results also indicated that prostaglandin F2 alpha does not directly stimulate release of oxytocin or progesterone from luteal cells in vitro.     

Effect of Isomeric cis-Octadecenoic Acids on the Growth of Leptospira interrogans Serotype patoc

Leptospira interrogans serotype patoc exhibited an increasing growth response when cultivated in media containing from 50 to 250 mug of sodium oleate per ml. Leptospiral growth in the presence of 250 mug of sodium oleate per ml was as good as that in the basal medium which contained 700 mug of oleic acid (in Tween 80) per ml. When positional isomers of oleic acid (9-octadecenoic acid) were present at a concentration of 200 mug/ml, the 2- and 8-isomers were not readily utilized, whereas the 3-, 4-, 6-, 11-, 15-, and 16-isomers gave a growth response equivalent to that of oleic acid, i.e., the 9-isomer. The 5-, 7-, 10-, 12-, 13-, 14-, and 17-isomers of octadecenoic acid induced growth responses which differed in magnitude but were intermediate to those of 2-18:1 and 3-18:1. When 200 mug of either 2- or 3-octadecenoic acid per ml was added in addition to 200 mug of 9-18:1 alone; 400 mug of 9-18:1 alone per ml inhibited growth of this organism. The growth response of leptospira to octadecenoic acids differed from that of mammalian cells, suggesting the presence of different enzymes in the two systems for the utilization of these substrates.     

The effect of octadecenoic acid on the growth of japanese encephalitis virus in Novikoff hepatoma cells.

The growth characteristics of Japanese encephalitis virus cultivated in Novikoff hepatoma cells grown in shaker culture can be differentially altered by the presence of 6-cis or cis-9-octadecenoic acid in Swim's 67-G medium. The addition of 125 mug of the 6-isomer per ml medium reduced the number of infectious particles produced, whereas the same amount of the 9-isomer enhanced virus production. The virus was found to be more stable in cell-free spent medium than in fresh medium. The presence of 125 mug 6-18:1 per ml in fresh medium resulted in a rapid loss of virus infectivity.     

Ovarian irradiation and prednisone therapy following surgery and radiotherapy for carcinoma of the breast.

Following mastectomy, patients with operable breast cancer underwent postoperative irradiation of the chest wall and regional lymph nodes. They were then assigned at random to receive no further therapy, ovarian irradiation (2000 rads in 5 days) or ovarian irradiation in the same dosage plus prednisone, 7.5 mg daily. A total of 705 patients received the randomly assigned treatment and were followed for up to 10 years. In premenopausal patients who received ovarian irradiation the recurrence of breast cancer was delayed and survival prolonged, but not significantly. In premenopausal women aged 45 years or more ovarian irradiation plus prednisone therapy significantly delayed the recurrence of breast cancer (P = 0.02) and prolonged survival (P = 0.02); the survival expectancy of these patients was similar to that of the general population of the same age from the third year after the cancer operation. No value was demonstrated for ovarian irradiation with or without prednisone therapy in postmenopausal patients.     

Nematospiroides dubius: susceptibility to infection and the development of resistance in hypothymic (nude) BALB/c mice.

BALB/c-nu/nu mice and their intact nu/+ littermates are equally susceptible to infection with third-stage larvae of Nematospiroides dubius. Unlike their heterozygous littermates, however, the nu/nu mice are unable to form ganulomata in the intestinal wall and become only partially resistant to rechallenge. Following two or more infections, nu/nu mice maintain a high burden of adult intestinal worms, whereas worms are lost from immune nu/+ mice. Studies in T cell-injected nu/nu mice suggest that a full complement of T cells is needed to develop maximum resistance against the infective third-stage larvae and to expel adult worms. Measurement of serum immunoglobulin levels indicate that infected nu/+ mice have very high levels of IgG1 whereas the levels of IgG2a are reduced. In infected T cell-injected nu/nu mice, IgG1 levels increase with the number of T cells injected, whereas IgG2a levels are variable but always higher than in infected nu/+ mice.     

Changes in the activity of the reticulo-endothelial system of rats during an infection with T. lewisi.

Data presented show that during the course of a Trypanosoma lewisi infection in rats there was both an activation of the phagocytic cells of the liver and spleen and an increase in their numbers. There was a marked lymphoid hyperplasia in the white pulp of the spleen with an increase in the number and size of the lymphoid follicles. Degenerative changes occurred in the liver parenchymal cells during the infection, and at certain stages large numgers of mononuclear cells were observed in the vascular sinusoids and other vessels of the liver.