Kinetics of Bartonella birtlesii infection in experimentally infected mice and pathogenic effect on reproductive functions.

The kinetics of infection and the pathogenic effects on the reproductive function of laboratory mice infected with Bartonella birtlesii recovered from an Apodemus species are described. B. birtlesii infection, as determined by bacteremia, occurred in BALB/c mice inoculated intravenously. Inoculation with a low-dose inoculum (1.5 x 10(3) CFU) induced bacteremia in only 75% of the mice compared to all of the mice inoculated with higher doses (> or =1.5 x 10(4)). Mice became bacteremic for at least 5 weeks (range, 5 to 8 weeks) with a peak ranging from 2 x 10(3) to 10(5) CFU/ml of blood. The bacteremia level was significantly higher in virgin females than in males but the duration of bacteremia was similar. In mice infected before pregnancy (n = 20), fetal loss was evaluated by enumerating resorption and fetal death on day 18 of gestation. The fetal death and resorption percentage of infected mice was 36.3% versus 14.5% for controls (P < 0.0001). Fetal suffering was evaluated by weighing viable fetuses. The weight of viable fetuses was significantly lower for infected mice than for uninfected mice (P < 0.0002). Transplacental transmission of Bartonella was demonstrated since 76% of the fetal resorptions tested was culture positive for B. birtlesii. The histopathological analysis of the placentas of infected mice showed vascular lesions in the maternal placenta, which could explain the reproductive disorders observed. BALB/c mice appeared to be a useful model for studying Bartonella infection. This study provides the first evidence of reproductive disorders in mice experimentally infected with a Bartonella strain originating from a wild rodent.

Epidemiology of Bartonella infection in domestic cats in France.

Blood samples were collected between February and June 1996 from a convenience sample of 436 domestic French cats living in Paris and its environs and were tested for Bartonella bacteremia and seropositivity. Seventy-two cats (16.5%) were Bartonella bacteremic, of which 36 cats (50%) were infected with Bartonella henselae type II (B.h. II) only, 15 cats (21%) were infected with Bartonella clarridgeiae (B.c.) only, and 11 cats (15%) were infected with B. henselae type I (B.h. I) only. Eight cats (11%) were co-infected with B. henselae and B. clarridgeiae (B.h. II/B.c.: five cats; B.h. I/B.c.: three cats). Two cats (2.8%) were concurrently bacteremic with B. henselae types I and II. Risk factors associated with bacteremia included ownership for <6months (prevalence ratio (PR)=1.80; 95% confidence interval (CI)=1.13-2.85), adoption from the pound or found as a stray (PR=1.67, 95% CI=1.05-2.65), and cohabitation with one or more cats (PR=1.60, 95% CI=1.01-2.53). Bartonella antibodies to either B. henselae or B. clarridgeiae were detected in 179 cats (41.1%). Risk factors associated with seroposivity paralleled those for bacteremia, except for lack of association with time of ownership. Prevalence ratios of bacteremic or seropositive cats increased with the number of cats per household (p=0.02). The lack of antibodies to B. henselae or B. clarridgeiae was highly predictive of the absence of bacteremia (predictive value of a negative test=97.3%). Multiple logistic regression analysis indicated that bacteremia, after adjustment for age and flea infestation, and positive serology, after adjustment for age, were associated with origin of adoption and number of cats in the household. Flea infestation was associated with positive serology.

Pregnancies modulate B lymphopoiesis and myelopoiesis during murine ageing.

We recently reported that pregnancy affects age-related changes in the distribution of lymphoid and macrophage populations in the spleen of C57Bl/6 mice. In the present study, we examined the influence of pregnancies on the generation of various developmental B-cell subsets and granulocyte/macrophage lineage cells during murine ageing. Using flow cytometry, changes in lymphoid (mature and early B-cell precursors: B220high, B220low, surface immunoglobulin M (sIgM) mu chain +/-) and myeloid (monocyte/macrophage Mac-1/CD11b, granulocyte Gr-1/Ly-6G) compartments were monitored in the bone marrow of young (2 months) and 15- and 23-month-old mice including male, multiparous and virgin female mice. Pregnancies delayed the age-related decline in murine B lymphopoiesis and maintained B-cell reserve capacity during ageing. We also found an increased production of myeloid cells induced by pregnancies at middle (15 months) and advanced (23 months) ages. This comparative study provides new information on changes in marrow lymphopoiesis and myelopoiesis with age. Our data emphasizes that the onset, magnitude and kinetics of age-related changes in the haematopoietic marrow are parity dependent. These changes could influence the incidence of age-related diseases and may account for the greater longevity of females.

Sex and parity modulate cytokine production during murine ageing.

We have previously shown that physiological hormone differences related to pregnancy or sex affect the age-related distribution of mononuclear cell populations during murine ageing. To determine whether such changes are involved in the age-related changes in functions of T cells, we examined the secretion of major T cell immunoregulatory cytokines (IL-2, IL-4, interferon-gamma (IFN-gamma), IL-3, IL-6 and granulocyte-macrophage colony-stimulating factor (GM-CSF)) of in vitro concanavalin A-activated spleen cells of C57B1/6 mice. The study included multiparous and virgin females and males at 2, 8, 15 and 23 months of age. Short-term effects of parity (8 months) were evidenced by the decrease of IFN-gamma and the preserved IL-2 production in multiparous females (8 months), while IFN-gamma was unchanged and IL-2 decreased in virgin mice. The increase in IL-4 production appeared earlier in multiparous females (15 months) than in virgin mice (23 months). The increase in IL-4/IFN-gamma and IL-4/IL-2 ratios at 8 and 15 months, respectively, in multiparous females, suggests that pregnancy modifies the Th1/Th2 equilibrium. In late adulthood (15 months), IL-6 and GM-CSF production was higher in multiparous females than in virgin males or females. Sex differences were also noticed: IFN-gamma secretion capacity was lower in males than in females during ageing. This study underlines that the onset, magnitude and kinetics of the age-related changes in cytokine production are parity- and sex-dependent. These changes probably influence the incidence of age-related diseases and may explain the greater longevity of females.

Surface antigen expression in spleen cells of C57B1/6 mice during ageing: influence of sex and parity.

So far all studies on the murine ageing process have been conducted on virgin mice. Immune ageing may be influenced by sex hormone differences related to sex or pregnancies. The aim of this study was to investigate whether pregnancies and gender influence the cell changes observed during ageing in a peripheral lymphoid compartment of C57B1/6 mice. Using flow cytometry, changes in (Thy1.2+) T cell, (B220+) B cell and (CD 11b/Mac-1) macrophage spleen populations were monitored in 2, 8 (3 months after last pregnancy) 15 and 23-month-old mice including males, virgin and multiparous females. The development of naive (CD44(low)), memory (CD44(high)), activated/memory (MEL-14, CD62L) cells were investigated in CD4+ and CD8+ T cell subsets. Both short term (at 8 months) and long term (at 15 and 23 months) effects of multiparity were obvious in the lymphocyte/macrophage population changes associated with the ageing process. Short-term effects included delayed appearance of CD4+CD44(high) memory lymphocytes and increased numbers of both CD4+MEL-14(1ow) activated/memory cells and Mac-1+ macrophages when compared with virgin control mice. Later effects of multiparity were increased CD8alpha(dull) populations and increased T/B cell ratios and the ratio of memory to naive CD4+ cells (CD44+(high)/CD44+(low). A sex effect was noticed: males exhibited lower Mac-1+ levels and memory/naive ratio in CD4+ subset than virgin females throughout life. These results suggest that gender and/or pregnancies affect the age-related distribution of lymphoid and macrophage cell populations in the spleen of C57B1/6 mice.

Stimulatory effects of polar glycopeptidolipids of Mycobacterium chelonae on murine haematopoietic stem cells and megakaryocyte progenitors.

The effects of polar glycopeptidolipids of Mycobacterium chelonae (pGPL-Mc) on haematopoietic stem cells and on megakaryocyte progenitors in bone marrow (BM) and spleen were investigated in mice. We studied the in vivo spleen colony-forming ability and marrow repopulating ability of pGPL-Mc by assays of colony-forming units-spleen (CFU-S). The number of CFU-S was increased in BM when both donors and recipients were treated with pGPL-Mc. In contrast, a single treatment of donors induced enhancement of spleen CFU-S. The number of pre-CFU-S was not significantly increased by pGPL-Mc injection. Megakaryocyte (Meg) progenitors were determined in vitro with a quantitative cultural analysis of bone marrow and spleen cells in agar in the presence of spleen-conditioned medium. A statistically significant increase in BM and spleen CFU-Meg was observed two days after the last administration of pGPL-Mc. This experiment points out the ability of pGPL-Mc to induce substantial stimulation of megakaryocytopoiesis and slight proliferation of stem cells in BM, but which is more pronounced in spleen. This molecule therefore appears to be a potential adjuvant of chemo- and radiotherapy in order to palliate the cytotoxic side effects of these cancer therapeutic modalities.

Monoamniotic twin pregnancies. Review of the literature, and a case report with vaginal delivery.

OBJECTIVE: To specify the process of the sometimes difficult diagnosis of monoamniotic twin pregnancies, as well as the best practise for delivery of this type of pregnancy. METHOD: Using their personal observation (a patient with a monoamniotic twin pregnancy, which presented a vaginal delivery at 35 weeks of gestation, two girls, in cephalic presentation, without particular problem, despite an entanglement of the cord and the existence of a knot), the authors established a review of the literature on this subject. RESULTS: Monoamniotic twin pregnancies represent a rare possibility. The prognosis is traditionally somber: 40-60% mortality, mainly due to pathologies of the cord. The review of the recent literature shows that most authors remain in favour of weekly ultrasound supervision from the 23rd week and of caesarean section in principle at 34 weeks (or from fetal pulmonary maturation). CONCLUSION: In the absence of funicular compression signs by colour-doppler, and under the cover of flawless obstetrical conditions, vaginal delivery can only be authorized for cases when both presentations are cephalic.

Effects of polar glycopeptidolipids of Mycobacterium chelonae (pGPL-Mc) on haematopoietic regeneration and resistance to infection of sublethally irradiated mice.

The influence of polar glycopeptidolipids of Mycobacterium chelonae (pGPL-Mc) treatment on the reversal of irradiation-induced leukopenia (granulocytopenia, monocytopenia) and thrombocytopenia and its ability to protect mice against lethal infections were investigated in this study. The administration of pGPL-Mc to irradiated mice significantly accelerated the recovery of leukocyte and thrombocyte numbers in the peripheral blood. Granulocytes and monocytes were the principal cells of the leukocyte population that responded to the potent stimulus of this product. The reversal of granulocytopenia and monocytopenia in treated mice was achieved on day 14 and reached a peak value on day 20. Responses in mice receiving 100 mg/kg of pGPL-Mc was about 40-fold compared to controls and about 4-fold compared to the rhG-CSF-treated group. Normal levels of thrombocytes were reached by day 17 in mice treated with 100 mg/kg and by day 20 in those receiving 25 mg/kg of pGPL-Mc. The administration of pGPL-Mc to mice with irradiation-induced granulocytopenia was characterized by highly significant protection of these animals against lethal Klebsiella pneumoniae or Escherichia coli infections. Therefore, pGPL-Mc appears to possess a considerable potential for improvement of the outcome of radiotherapy and may contribute to the successful avoidance of irradiation-induced toxicities.

Effects of polar glycopeptidolipids of Mycobacterium chelonae (pGPL-Mc) on granulomacrophage progenitors.

Effects of polar glycopeptidolipids of Mycobacterium chelonae (pGPL-Mc) in the in vivo stimulation of haematopoietic growth and differentiation of murine bone marrow and spleen cells was investigated in this study. Progenitors were determined with a quantitative cultural analysis of bone marrow and spleen cells in methylcellulose using rmGM-CSF and rmIL3. Injection of pGPL-Mc produced a significant time-related increase in the number of bone marrow and spleen CFUs. pGPL-Mc treatment, in particular, increased the number of bone marrow and splenic CFU-GMs, CFU-Gs and CFU-Ms during and after three intraperitoneal administrations. The greatest myeloid stimulation of bone marrow CFU-GMs, CFU-Gs and CFU-Ms was observed between days 7 and 14, with maximal values on days 12 and 14. Highly significant stimulation of splenic CFU-GMs, CFU-Gs and CFU-Ms was observed between days 7 and 10 with maximal values on day 10, while the initial stimulation of these progenitors was observed starting from day 1 in bone marrow and day 7 in spleen. These effects of pGPL-Mc were associated with an increase in granulocyte, monocyte and thrombocyte counts in the peripheral blood. Granulocyte and monocyte counts remained high up until day 12, while those of thrombocytes were prolonged until day 18. May-Grünwald-Giemsastained colony samples and differential white blood cell counts demonstrated that the granulocyte population is composed almost entirely of neutrophils. pGPL-Mc is therefore a broad-spectrum haematopoietic growth factor with a highly promising application in the reversal of chemotherapy- and/or radiotherapy-induced myelo-suppression.

Retinal ganglion cell death in experimental glaucoma and after axotomy occurs by apoptosis.

PURPOSE: To investigate whether retinal ganglion cell death in experimental glaucoma and after axotomy occurs by apoptosis. METHODS: Chronic elevated eye pressure was produced in 20 monkey eyes, and the optic nerve was transected unilaterally in the orbit of 10 monkeys and 14 rabbits. Sixteen monkey and 14 rabbit eyes were studied as normal controls. Analytic methods included light and electron microscopy, histochemistry for DNA fragmentation (TUNEL method), and DNA electrophoresis in agarose gels. RESULTS: Dying ganglion cells in the experimental retinas exhibited morphologic features of apoptosis, including chromatin condensation and formation of apoptotic bodies. Cells with a positive reaction for DNA fragmentation were observed in eyes subjected to axotomy and experimental glaucoma but were only rarely encountered in control eyes. No evidence of internucleosomal fragmentation was detected electrophoretically, possibly because of the small proportion of cells that were dying at any given time. CONCLUSION: Some retinal ganglion cells injured by glaucoma and by axotomy die by apoptosis.

[Vaginal delivery of monochorionic, monoamniotic twins. Clinical case]. / Accouchement par voie basse d'une grossesse monochoriale monoamniotique. Cas clinique.

Monochorial-monoamniotic female twins were delivered by the vaginal route with no particular problem after 37 week gestation. Cephalic presentation for both infants was not hindered by a tangled cord with a knot.

Change in the appearance of elastin in the lamina cribrosa of glaucomatous optic nerve heads.

Elastin fibers in the lamina cribrosa of glaucoma eyes have a curled appearance when the tissue is fixed at atmospheric pressure. To evaluate the effect of preparation conditions on elastin appearance, we set the eye pressure at one of four levels during tissue fixation in 18 glaucoma and 16 normal eyes. Glaucomatous damage was associated with an abnormal appearance of elastin at each pressure level. The majority of glaucoma eyes (11/18) had curled elastin profiles. In glaucoma eyes with definite nerve damage, elastin was graded moderately or severely abnormal in 47% (7/15), while in normal controls the rate of similar curling was 6% (1/16). The severity of abnormal elastin appearance was lower in glaucoma eyes that were fixed and frozen at higher intraocular pressures, but the difference was not statistically significant.

Glaucoma filtration surgery in nonhuman primates using taxol and etoposide in polyanhydride carriers.

PURPOSE: To determine the effect of taxol and etoposide, hydrophobic drugs with antifibrosis activity, on the outcome of filtration surgery in glaucomatous monkeys. METHODS: Elevated intraocular pressure was produced bilaterally in eight cynomolgus monkeys by laser treatment of the trabecular meshwork. Four animals subconjunctivally received a polyanhydride disk containing 1 mg etoposide at the time of posterior lip sclerectomy in one eye; the other eye received an identical disk without drug. Similarly, four animals received a disk containing 50 micrograms of taxol in one eye and a blank disk in the other. RESULTS: Eyes treated with taxol had lower intraocular pressures than control eyes from 20 days after surgery until death. Eyes with satisfactory filtration bleb appearance and patent fistulae on histologic examination had lower intraocular pressures. The intraocular pressure was lower and the duration of success longer in the etoposide-treated eyes (mean, 16 days) compared to that of the fellow eyes (mean, 10 days), but the difference was not statistically significant. CONCLUSIONS: Use of polyanhydride disks containing taxol, but not etoposide, had a marked beneficial effect on intraocular pressure and bleb appearance after experimental filtration surgery in monkeys. The difference between the two agents may result from the greater antiproliferative potency of taxol and its greater duration of release from the polymer.

The carboxy terminus of sodium and potassium ion transporting ATPase is located on the cytoplasmic surface of the membrane.

The positions, with respect to the plasma membrane, of lysine 905, contained in the peptide QRKIVE, and of lysine 1012, contained in the carboxy-terminal peptide, RPGGWVEKETYY, of ovine Na+/K(+)-transporting ATPase have been reported to be cytoplasmic and extracytoplasmic, respectively [Bayer, R. (1990) Biochemistry 29, 2551-2256]. These results from our laboratory have been reexamined using an extension of the same procedure. Sealed right-side-out vesicles were modified with pyridoxal phosphate and sodium [3H]borohydride in the presence and absence of saponin or cholate. The modified alpha polypeptide was isolated and digested with the proteinase from Staphylococcus aureus strain V8 or trypsin to produce one or the other of these two peptides. These digests were passed over immunoadsorbents, identical to those used by Bayer, directed against pyroglutamylRXIVE or -ETYY. Unlike in the earlier studies, however, in the present studies the modified, radioactive peptides bound and eluted from the immunoadsorbents were submitted to HPLC, and their respective mobilities were compared to those of the synthetic peptides that had also been modified with pyridoxal phosphate. In this manner, the correct, modified peptide could be positively identified, and its specific radioactivity could be estimated. When cholate was added to sealed vesicles, prior to modification, there was at least a 3-fold increase in the incorporation of radioactivity into lysine 1012, consistent with a cytoplasmic location for this residue.(ABSTRACT TRUNCATED AT 250 WORDS)

Germination of seeds from an irradiated forest: implications for waste disposal.

Jack pine (Pinus banksiana Lamb.) retain their seeds from year to year, so that in an irradiated forest, each tree receives a specific dose rate but has seeds that have accumulated a range of total doses. The Field Irradiator-Gamma facility in Pinawa, Manitoba, contains jack pine that have been irradiated longer and at lower dose rates than previously reported. Seed germination and germination rate were examined on seeds irradiated on the parent tree for up to 5 years. Germination rate was most sensitive and showed deleterious effects at 1.1 mGy hr-1. This is not much lower than results reported by others in shorter-term studies. Effects were related to dose rate rather than total dose. Hormesis, indicated by statistically significant increased germination rate, was evident at 0.6 mGy hr-1. To put these results into context, the concentrations of selected radionuclides that, through internal contamination, would deliver 1.1 mGy hr-1 to plants were estimated. For 99Tc and 129I, these concentrations are far above the chemical toxicity thresholds for plants. Clearly, as assessments of waste repositories begin to consider effects on organisms other than humans, such as plants, chemical toxicity will be an important feature.

Effect of topical mitomycin C on glaucoma filtration surgery in monkeys.

In this study, an experimental model of glaucoma filtration surgery was used to evaluate the clinical and histologic effects of a single intraoperative topical application of mitomycin C. Argon laser treatment to the trabecular meshwork produced sustained elevation of intraocular pressure in monkeys. Eight eyes of four animals were randomly assigned to receive topical mitomycin C or balanced salt solution at the time of full-thickness sclerostomy. Surgical success was substantially increased in four of five eyes that received mitomycin C when compared with three eyes that received topical balanced salt solution. Mitomycin C was also effective in prolonging surgical success in two eyes that had previously undergone surgery and failed. No significant ocular toxicity was observed in eyes treated with mitomycin C. Histologic examination of mitomycin C-treated eyes showed patent sclerostomies and hypocellular, well-formed bleb cavities. A single intraoperative application of mitomycin C has a marked effect on postoperative wound healing after filtration surgery in monkeys.

[Activity of polar glycopeptidolipids from Mycobacterium chelonae in the reversal of chemically induced leukopenia in mice]. / Activité des glycopeptidolipides polaires de Mycobacterium chelonae sur la restauration d'une leucopénie chimioinduite chez la souris.

Intraperitoneal administration of polar glycopeptidolipids extracted from Mycobacterium chelonae (GPLp-Mc) has led to reversal of Doxorubicin-induced leucopenia in a manner comparable to that effected by GM-CSF administered in a dose of 100 IU (2.5 micrograms/kg). The mode of action and the toxicity of this product are being studied. Results obtained on the mouse indicate that it would be worthwhile to undertake tests in man aimed at studying the effect of GPLp-Mc on chemotherapy- and radiotherapy-induced leukopenias, once toxicological studies have been carried out.