Cumulus cells of the oocyte play important roles in in vitro maturation and subsequent development. One of the routes by which the factors are transmitted from cumulus cells to the oocyte is gap junctional communication (GJC). The function of cumulus cells in in vitro maturation of porcine oocytes was investigated by using a gap junction inhibitor, heptanol. Cumulus-oocyte complexes (COCs) were collected from the ovaries of slaughtered gilts by aspiration. After selection of COCs with intact cumulus cell layers and uniform cytoplasm, they were cultured in a medium with 0, 1, 5, or 10 mM of heptanol for 48 h. After culture in vitro, one group of oocytes was assessed for nuclear maturation and glutathione (GSH) content, and another group was assigned to in vitro fertilization and assessed for the penetrability of oocytes and the degree of progression to male pronuclei (MPN) of penetrated spermatozoa. At the end of in vitro maturation, the oocytes reached metaphase II at a high rate (about 80%) regardless of the presence of heptanol at various concentrations. Cumulus cell expansion and the morphology of oocytes cultured in the medium with heptanol were similar to those of control COCs matured without heptanol. The amount of GSH in cultured oocytes tended to decrease as the concentration of heptanol in the medium was increased. Although there was no difference in the rates of penetrated oocytes cultured in media with different concentrations of heptanol, the proportion of oocytes forming MPN after insemination decreased significantly (P < 0.01) at all concentrations tested. A higher rate of sperm (P < 0.01) failed to degrade their nuclear envelopes after penetration into the oocytes that were treated with heptanol. GJC between the oocyte and cumulus cells might play an important role in regulating the cytoplasmic factor(s) responsible for the removal of sperm nuclear envelopes as well as GSH inflow from cumulus cells.

The authors analysed the antigen-presenting ability of eosinophils purified from peritoneal exudate cells of interleukin-5 (IL-5) transgenic mice. The granulocyte-macrophage colony-stimulating factor (GM-CSF)-treated eosinophils induced proliferative responses of primed lymph node T cells and thymus T cells to staphylococcal enterotoxin B (SEB), while untreated eosinophils induced little or no response. GM-CSF-treated eosinophils also induced proliferation of ovalbumin (OVA)-primed lymph node T cells to OVA. Although untreated eosinophils expressed no MHC class II molecule on the surface the eosinophils could be induced to express major histocompatibility complex (MHC) class II molecules when treated with GM-CSF. In the present study, anti-I-Ak monoclonal antibodies (MoAbs) strongly inhibited proliferation of thymus T cells and proliferation of OVA-primed lymph node T cells in response to OVA, but weakly inhibited proliferation of primed T cells in response to SEB. Furthermore, CD80 (B7-1) and CD86 (B7-2) were expressed on the surfaces of untreated eosinophils. The expression of those two molecules on the eosinophils was increased by incubation with GM-CSF. Moreover, anti-CD80 or anti-CD86 MoAbs blocked proliferative responses of primed lymph node T cells and thymus T cells to SEB, and also blocked responses of primed lymph node T cells to OVA. Thus, CD80 and CD86 play an important role in stimulation of T cells by eosinophils.

BackgroundDuring an entomological survey in preparation for malaria control interventions in Mwea division, the number of malaria cases at the Kimbimbi sub-district hospital was in a steady decline. The underlying factors for this reduction were unknown and needed to be identified before any malaria intervention tools were deployed in the area. We therefore set out to investigate the potential factors that could have contributed to the decline of malaria cases in the hospital by analyzing the malaria control knowledge, attitudes and practices (KAP) that the residents in Mwea applied in an integrated fashion, also known as integrated malaria management (IMM).MethodsIntegrated Malaria Management was assessed among community members of Mwea division, central Kenya using KAP survey. The KAP study evaluated community members' malaria disease management practices at the home and hospitals, personal protection measures used at the household level and malaria transmission prevention methods relating to vector control. Concurrently, we also passively examined the prevalence of malaria parasite infection via outpatient admission records at the major referral hospital in the area. In addition we studied the mosquito vector population dynamics, the malaria sporozoite infection status and entomological inoculation rates (EIR) over an 8 month period in 6 villages to determine the risk of malaria transmission in the entire division.ResultsA total of 389 households in Mwea division were interviewed in the KAP study while 90 houses were surveyed in the entomological study. Ninety eight percent of the households knew about malaria disease while approximately 70% of households knew its symptoms and methods to manage it. Ninety seven percent of the interviewed households went to a health center for malaria diagnosis and treatment. Similarly a higher proportion (81%) used anti-malarial medicines bought from local pharmacies. Almost 90% of households reported owning and using an insecticide treated bed net and 81% reported buying the nets within the last 5 years. The community also used mosquito reduction measures including, in order of preference, environmental management (35%), mosquito repellent and smoke (31%) insecticide canister sprays (11%), and window and door screens (6%). These methods used by the community comprise an integrated malaria management (IMM) package. Over the last 4 years prior to this study, the malaria cases in the community hospital reduced from about 40% in 2000 to less than 10% by 2004 and by the year 2007 malaria cases decreased to zero. In addition, a one time cross-sectional malaria parasite survey detected no Plasmodium infection in 300 primary school children in the area. Mosquito vector populations were variable in the six villages but were generally lower in villages that did not engage in irrigation activities. The malaria risk as estimated by EIR remained low and varied by village and proximity to irrigation areas. The average EIR in the area was estimated at 0.011 infectious bites per person per d...

In mammals, circadian genes, Clock, Arntl (also known as Bmal1), Cry1, Cry2, Per1, Per2, and Per3, are rhythmically transcribed every 24 h in almost all organs and tissues to tick the circadian clock. However, their expression and function in oocytes and preimplantation embryos have not been investigated. In this study we found that the circadian clock may stop in mouse oocytes and preimplantation embryos. Real-time PCR analysis revealed the presence of transcripts of these genes in both oocytes and preimplantation embryos; however, their amounts did not oscillate every 24 h in one- to four-cell and blastocyst-stage embryos. Moreover, immunofluorescence analyses revealed that CLOCK, ARNTL, and CRY1 were localized similarly in the nuclei of germinal vesicle (GV) oocytes and one-cell- to four-cell-stage embryos. Because CRY1 is known to interact with the CLOCK-ARNTL complex to suppress transcription-promoting activity of the complex for genes such as Wee1, Cry2, Per1, Per2, and Per3 in cells having the ticking circadian clock, we hypothesized that if the circadian clock functions in GV oocytes and one-cell- to four-cell-stage embryos, CLOCK, ARNTL, and CRY1 might suppress the transcription of these genes in GV oocytes and one-cell- to 4-cell-stage embryos as well. As a result, knockdown of CRY1 in GV oocytes by RNA interference did not affect the transcription levels of Wee1, Cry2, Per1, Per2, and Per3, but it reduced maturation ability. Thus, it seems that circadian genes are not involved in circadian clock regulation in mouse oocytes and preimplantation embryos but are involved in physiologies, such as meiosis.

Methanolic extracts from 15 medicinal plants representing 11 families, used traditionally for malaria treatment in Kenya were screened for their in vivo antimalarial activity in mice against a chloroquine (CQ)-tolerant Plasmodium berghei NK65, either alone or in combination with CQ. The plant parts used ranged from leaves (L), stem bark (SB), root bark (RB), seeds (S) and whole plant (W). When used alone, extracts from seven plants, Clerodendrum myricoides (RB), Ficus sur (L/SB/RB), Maytenus acuminata (L/RB), Rhamnus prinoides (L/RB), Rhamnus staddo (RB), Toddalia asiatica (RB) and Vernonia lasiopus (RB) had statistically significant parasitaemia suppressions of 31.7-59.3%. In combination with CQ, methanolic extracts of Albizia gummifera (SB), Ficus sur (RB), Rhamnus prinoides and Rhamnus staddo (L/RB), Caesalpinia volkensii (L), Maytenus senegalensis (L/RB), Withania somnifera (RB), Ekebergia capensis (L/SB), Toddalia asiatica (L/RB) and Vernonia lasiopus (L/SB/RB) gave statistically significant and improved suppressions which ranged from 45.5 to 85.1%. The fact that these activities were up to five-fold higher than that of extract alone may suggest synergistic interactions. Remarkable parasitaemia suppression by the extracts, either alone or in combination with CQ mostly resulted into longer mouse survival relative to the controls, in some cases by a further 2 weeks. Plants, which showed significant antimalarial activity including Vernonia lasiopus, Toddalia asiatica, Ficus sur, Rhamnus prinoides and Rhamnus staddo warrant further evaluation in the search for novel antimalarial agents against drug-resistant malaria.