The prospect of biological attacks is a growing strategic threat. Covert aerosol attacks inside a building are of particular concern. In the summer of 2005, the Center for Biosecurity of the University of Pittsburgh Medical Center convened a Working Group to determine what steps could be taken to reduce the risk of exposure of building occupants after an aerosol release of a biological weapon. The Working Group was composed of subject matter experts in air filtration, building ventilation and pressurization, air conditioning and air distribution, biosecurity, building design and operation, building decontamination and restoration, economics, medicine, public health, and public policy. The group focused on functions of the heating, ventilation, and air conditioning systems in commercial or public buildings that could reduce the risk of exposure to deleterious aerosols following biological attacks. The Working Group's recommendations for building owners are based on the use of currently available, off-the-shelf technologies. These recommendations are modest in expense and could be implemented immediately. It is also the Working Group's judgment that the commitment and stewardship of a lead government agency is essential to secure the necessary financial and human resources and to plan and build a comprehensive, effective program to reduce exposure to aerosolized infectious agents in buildings.

Objective-To determine whether Mycoplasma haemofelis (Mhf) and Candidatus Mycoplasma haemominutum (Mhm) can be transmitted by ingestion of Mycoplasma-infected Ctenocephalides felis and by-products (feces, larvae, and eggs).Animals-10 cats.Procedure-3 cats were carriers of Mhf, and 1 was a carrier of Mhm. Six cats had negative results of PCR assay for Mhf and Mhm DNA. A chamber containing 100 C felis was bandaged to 2 Mhf carrier cats. Five days later, fleas and by-products were analyzed for Mycoplasma spp DNA. The remaining fleas and a sample of by-products were fed to 2 Mycoplasma-naive cats. A chamber containing 200 C felis was bandaged to the Mhm carrier cat. Five days later, fleas and by-products were analyzed for Mycoplasma spp DNA. The remaining fleas and a sample of by-products were fed to 2 Mycoplasma-naive cats. A chamber containing 200 C felis was bandaged to an Mhf-carrier cat and Mhm-carrier cat. Three days later, fleas and by-products were analyzed for Mycoplasma spp DNA. The remaining fleas and a random sample of byproducts were fed to 4 Mycoplasma-naive cats. All cats were monitored for infection for >= 7 weeks.Results-Uptake of Mhf and Mhm DNA into fleas and by-products was detected. None of the naive cats became infected.Conclusions and Clinical Relevance-Results suggested that ingestion of Mycoplasma-infected C felis or by-products is not an important means of transmission for Mhf or Mhm.

OBJECTIVE:To determine whether Ctenocephalides felis can transmit Mycoplasma haemofelis (Mhf) and Candidatus Mycoplasma haemominutum (Mhm) through hematophagous activity between cats.ANIMALS:11 cats.PROCEDURE:2 cats were carriers of either Mhf or Mhm. Nine cats had negative results via polymerase chain reaction (PCR) assay for Mhf and Mhm DNA; 3 of those cats were infected from the chronic carriers via i.v. inoculation of blood. At the time of maximum organism count for each of the Mycoplasma spp, 1 chamber containing 100 C felis was bandaged to the amplifier cats. Five days later, fleas, feces, larvae, or eggs from each chamber were analyzed for Mycoplasma spp DNA. Viable fleas from the chambers were allocated into new chambers (3 Mhm and 6 Mhf) and attached to naïve cats for 5 days. Cats were monitored daily for clinical signs and weekly via CBC and PCR assay for infection with Mhf or Mhm for a minimum of 8 weeks.RESULTS:Uptake of Mhf and Mhm DNA into fleas, feces, and, potentially, eggs and larvae was detected. Of the naïve cats fed on by Mhf-infected fleas, 1 cat transiently yielded positive PCR assay results for Mhf on 1 sampling date without clinical or hematologic changes consistent with Mhf infection.CONCLUSIONS AND CLINICAL RELEVANCE:Results suggest that hematophagous transfer of Mhm and Mhf into fleas occurred and that C felis is a possible vector for Mhf via hematophagous activity.

Plasma concentrations of 17 beta-estradiol (E-2) and left ovarian histology were investigated by light and electron microscopy in female Japanese quail from Day 10 of embryonic development through Day 7, posthatch. Plasma E-2 levels remained relatively constant (102 to 140 pg/mL) in the embryo followed by a sharp decrease posthatch (47 to 70 pg/mL).Beginning on Day 10 of incubation, cells in the medullary portion (medullary cell; MC) of the left ovaries exhibited ultrastructural evidence of steroidogenic capability.The MC had numerous lipid droplets in close proximity to the smooth endoplasmic reticulum (SER). Mitochondria were also observed in the vicinity of the lipid droplets and SER. On Days 10 and 12, the cristae of the inner mitochondrial membranes were of a lamellar configuration; the cristae of some mitochondria in MC had a tubular appearance by Day 14. These data document relative ontogenic changes in ovarian morphology and plasma E-2 levels during the early developmental period in female Japanese quail. These data further support the role of this steroid in sexual differentiation.

The ontogeny of circulating concentrations of insulin-like growth factor (IGF-)-I, IGF-II, and IGF-binding proteins (IGF-BPs) was examined in the chick embryo. Distinct ontogenic changes in the circulating concentrations of IGF-I and IGF-II were observed. The present study confirms the overall profile for circulating concentrations of IGF-I. During middevelopment, plasma concentrations of IGF-I increased to a maximum which was attained on Day 14.5 of incubation. Thereafter, plasma concentrations of IGF-I declined with decreases (P < 0.05) between Days 14.5 and 15.5 and between Days 16.5 and 17.5 of incubation. In contrast to the monophasic profile for IGF-I, plasma concentrations of IGF-II were maximal on Day 10.5 of incubation and declined to a nadir on Day 17.5 of incubation. In late developmental stages (17.5 or 18.5 days of incubation), three IGF-BPs, having molecular weights of 22, 28, and 36 kDa, were detected in the plasma of chick embryos. No significant ontogenic changes in the circulating levels of the 28- and 36-kDa IGF-BPs were observed. However, it should be noted that prior to Day 17.5 of incubation, the 22-kDa IGF-BP was nondetectable in the circulation. The role of these changes in the functioning of IGF in embryonic development is discussed.

The effectiveness of a vertical displacement ventilation system was evaluated when contaminants including tobacco smoke were present. Air supply was through a perforated floor and carpet. System performance was evaluated using ADPI (Air Diffusion Performance Index), percentage dissatisfied due to draft, vertical temperature difference, and air change, and contaminant removal indices. Gaseous contaminants were simulated with tracer gas. Cigarettes and occupants also generated particulates, CO2, CO, and TVOC (total volatile organic compounds). Several combinations of supply air flow rate and thermal loads were evaluated. The risk of draft was found to be negligible. The air change effectiveness for the room varied from 126 to 145% and the contaminant removal effectiveness for the occupied zone varied from 80 to 700%.

Plasma luteinizing hormone (LH) concentrations and the numerical density (Nv) of gonadal LH-binding (LH-positive) cells were determined in intact male and female chick embryos from Days 10.5 through 18.5 of incubation for plasma LH and from Days 6.5 through 19.5 for LH-binding cells, as well as in Day 15.5 decapitated (“hypophysectomized”) embryos with pituitary transplants for both plasma LH and LH-binding cells. The data demonstrate that LH is already present in the plasma of male and female embryos as early as Day 10.5, the first day examined. Plasma LH levels in hypophysectomized embryos were statistically significantly lower than those of intact embryos, while pituitary transplants to the chorioallantoic membrane of hypophysectomized embryos elevated plasma LH concentrations to levels not statistically different from those of intacts. The “role(s)” of plasma LH levels and changes in form and numerical density (Nv) of gonadal LH-binding cells in the maturation of the pituitary-gonadal axes of the chick embryo are discussed and evaluated.

The Ets gene family codes for transcription factors containing a conserved DNA binding domain. The proto-oncogene c-ets1 is highly expressed in lymphoid organs and in developing mesodermal-originating structures. We studied c-ets1 gene expression in the developing rat hypothalamo-hypophyseal system, using in situ hybridization on paraformaldehyde-fixed frozen sections. At embryonic day 12 (E12) and E13, cells synthesizing c-ets1 mRNA are found in the neural tube where they form small, heavily labeled strand-like and punctate structures; positive mesenchymatous cells, corresponding to the surface capillary network, surround the brain and hypophysis. C-ets1 mRNA is synthesized from E14 in the neural pituitary and E15 in the adenohypophysis, during angiogenesis; no c-ets1 mRNA is detected in the avascular intermediate pituitary at any stage. Strand-like c-ets 1 mRNA labeling is intense from E14 to E21 in the diencephalon. This labeling is also detected during perinatal stages in the hypothalamic magnocellular nuclei, one of the most richly vascularized brain areas. In the rat hypothalamo-hypophyseal system, c-ets1 gene expression is maximal during fetal and perinatal stages and progressively decreases thereafter until adulthood. The spatio-temporal correlation observed between c-ets1 gene expression and blood vessel formation in the rat hypothalamus and pituitary suggests a role for c-ets 1 in angiogenesis in this system.

Plasma 17β-estradiol (E2) concentrations in male and female chick embryos were determined by radioimmunoassay (RIA) on Days 7.5, 9.5, 11.5, 12.5, 13.5, 14.5, 15.5, and 17.5 of development. E2 levels in female embryos increased gradually from Days 7.5 (889.5 pg/ml) to 12.5 (1003.8 pg/ml), followed by a marked increase from Days 13.5 (1103.3 pg/ml) to 17.5 (1360.2 pg/ml). In male embryos, E2 concentrations remained at a relatively constant level throughout the embryonic period studied (Day 7.5: 639.9 pg/ml; Day 17.5: 747.8 pg/ml) and were significantly lower than female E2 levels of the same age (P<0.001). A correspondence in embryonic time was observed between the two phases of the female plasma E2 profile (Days 7.5–12.5 and 13.5–17.5) and the biphasic growth and differentiation pattern of the female left Müllerian duct (Days 8.0–12.0 and 14.0–18.0). Results are also discussed in terms of other E2-dependent events which occur during chick embryo development.

In response to current concerns about the depletion rates of non-renewable energy resources, new codes and standards have been promulgated which require improved construction techniques and reduced ventilation rates. While implementation of these codes and standards has reduced energy consumption rates, degradation of indoor air quality has also been reported. These complaints indicate that arbitrary reduction of ventilation rates can result in deleterious effects to the occupants. Thus, a compromise solution is required with the objective to provide a safe, healthy, and comfortable indoor environment by using materials and methods that optimize efficiency of energy use.

The results of the present investigation constitute the first direct evidence of a difference in steroid hormone synthesis between gonads of intact and hypophysectomized chick embryos, as indicated by differences in the activity of histochemically demonstrable Δ5-3β-hydroxysteroid dehydrogenase (Δ5-3β-HSD), a key enzyme in steroidogenesis. This change is first observed on Day 13.5 of incubation, and is interpreted as demonstrating that the pituitary-gonadal axis first becomes functional at this time in the embryonic development of the chick.