A Study of the Effectiveness of Governmental Strategies for Managing Mortality from COVID-19.

We investigate the effectiveness of seven government containment and policy closure interventions against the novel coronavirus (SARS-COV-2) pandemic in the OECD countries, at several different time horizons. Our results indicate that only school closings and public transportation closings have a persistently significant impact. Stay-at-home policies only show a significant impact after 70 days.

Exceptional continental record of biotic recovery after the Cretaceous-Paleogene mass extinction.

We report a time-calibrated stratigraphic section in Colorado that contains unusually complete fossils of mammals, reptiles, and plants and elucidates the drivers and tempo of biotic recovery during the poorly known first million years after the Cretaceous-Paleogene mass extinction (KPgE). Within ~100 thousand years (ka) post-KPgE, mammalian taxonomic richness doubled, and maximum mammalian body mass increased to near pre-KPgE levels. A threefold increase in maximum mammalian body mass and dietary niche specialization occurred at ~300 ka post-KPgE, concomitant with increased megafloral standing species richness.

Basal anthropoids from Egypt and the antiquity of Africa's higher primate radiation.

Early anthropoid evolution in Afro-Arabia is poorly documented, with only a few isolated teeth known from before approximately 35 million years ago. Here we describe craniodental remains of the primitive anthropoid Biretia from approximately 37-million-year-old rocks in Egypt. Biretia is unique among early anthropoids in exhibiting evidence for nocturnality, but derived dental features shared with younger parapithecids draw this genus, and possibly >45-million-year-old Algeripithecus, into a morphologically and behaviorally diverse parapithecoid clade of great antiquity.

Mammalian dispersal at the Paleocene/Eocene boundary.

A profound faunal reorganization occurred near the Paleocene/Eocene boundary, when several groups of mammals abruptly appeared on the Holarctic continents. To test the hypothesis that this event featured the dispersal of groups from Asia to North America and Europe, we used isotope stratigraphy, magnetostratigraphy, and quantitative biochronology to constrain the relative age of important Asian faunas. The extinct family Hyaenodontidae appeared in Asia before it did so in North America, and the modern orders Primates, Artiodactyla, and Perissodactyla first appeared in Asia at or before the Paleocene/Eocene boundary.

A seroepidemiological study of Mycoplasma pneumoniae infections in Denmark over the 50-year period 1946-1995.

The epidemiological pattern of Mycoplasma pneumoniae infections in Denmark over the 50-year period 1946-1995 is described. The study is based on blood specimens received at the central laboratory at Statens Serum Institut for titration of cold agglutinins (CA), initially for the diagnosis of CA positive primary atypical pneumonia, and during the 1960s of M. pneumoniae infection; in addition, specimens from the last 38 years were tested for antibodies specific to M.

Mycoplasmal pericarditis: evidence of invasive disease.

Although the pathogenic mycoplasmas usually infect the respiratory and urogenital tracts, these organisms also can cause disease in remote sites. Such infections are difficult to diagnose because of both the fastidious nature of the mycoplasmas and the failure to consider their presence. Pericarditis is an uncommonly diagnosed and rarely confirmed example of invasive mycoplasmal infection.

Clinical overview of typical Mycoplasma pneumoniae infections.

A number of clinical and epidemiological factors permit the tentative identification of Mycoplasma pneumoniae infections. These selective factors can be considered the mainstay of diagnosis because they facilitate intelligent and efficient use of laboratory tests. The laboratory, in turn, through identification of the causative agent, augments both clinical and epidemiological data.

Epidemic pneumonia in university students.

Longitudinal surveillance of pneumonia in a university student health service was conducted from 1965-1971 and 1984-1987. Of 104 pneumonia cases documented by chest x-ray, only six were presumed to have bacterial etiology; the remaining 98 were characteristic of atypical pneumonia syndrome. Mycoplasma pneumoniae was the etiology in 51% of the pneumonias in the 1960s and 13% in 1984-1987.

Chlamydial and mycoplasmal pneumonias.

Chlamydia species and Mycoplasma pneumoniae are among the most common agents of community-acquired pneumonia, as well as causes of various nonpneumonic syndromes. Both can be considered "exotic" bacteria: Chlamydiae because they depend on host cell energy, hence their obligate intracellular replication; and M pneumoniae because it is an extracellular parasite that lacks the standard protective bacterial cell wall. The unusual biology of these organisms complicates laboratory diagnosis, but because both are susceptible to selective antimicrobials, therapy often proceeds empirically on clinical suspicion.

A Mycoplasma genitalium protein resembling the Mycoplasma pneumoniae attachment protein.

In previous studies with hyperimmune rabbit sera and monoclonal antibodies against the P1 protein of Mycoplasma pneumoniae, we obtained evidence of a shared antigenic determinant with a single protein of Mycoplasma genitalium. Because of biologic and morphologic similarities between these two human Mycoplasma species, attempts were made to characterize this cross-reacting protein of M. genitalium (designated MgPa).

Ureaplasma colonization: definitions and epidemiologic implications.

Genital mucosal colonization with Ureaplasma species complicates interpretation of their role as pathogens. From an epidemiologic point of view, colonization should be considered a dynamic process in which knowledge about the habitat colonized is an integral part. The classical criteria of pathogenicity need to be broadened to include qualitative, quantitative, and temporal aspects as disease associations of ureaplasmas are explored.

Antigenic determinants of the attachment protein of Mycoplasma pneumoniae shared by other pathogenic Mycoplasma species.

In previous studies with hyperimmune rabbit antisera, we found evidence of serologic cross-reactivity among Mycoplasma pneumoniae, Mycoplasma genitalium, and Mycoplasma gallisepticum. Because of certain biologic and morphologic similarities of these species, attempts were made to determine if this cross-reactivity related to the attachment protein (P1) of M. pneumoniae.

Demonstration of multiple antigenic determinants on Mycoplasma pneumoniae attachment protein by monoclonal antibodies.

Distinct multiple antigenic determinants of the attachment protein of Mycoplasma pneumoniae have been identified by limited proteolytic cleavage, using specific monoclonal antibodies. Western blots prepared from the gels containing the cleaved fragments were probed with antiserum against M. pneumoniae or monoclonal antibodies.

The changing pathogenicity of Mycoplasma pneumoniae with passage in vitro. Correlates of virulence.

An avirulent strain of Mycoplasma pneumoniae isolated by broth passage failed to produce pneumonia in hamsters. The major biological property lost in this avirulent strain is its ability to attach to the respiratory epithelium. Although the surface protein responsible for the specific attachment of virulent M.

Suppression of respiratory syncytial virus infection in cotton rats by bis(5-amidino-2-benzimidazolyl)methane.

Intraperitoneal administration of bis(5-amidino-2-benzimidazolyl)methane at well-tolerated daily doses of 25 mg/kg subsequent to challenge and for 3 days thereafter effected over a 1-log reduction in the amount of virus recovered from lungs of cotton rats inoculated intratracheally with respiratory syncytial virus. When animals were immunosuppressed to prolong virus shedding, the reduction in recovered virus achieved with a 7-day dosing schedule of bis(5-amidino-2-benzimidazolyl)methane exceeded 2 logs.

Conservation of pathogenic mycoplasma antigens.

The protein profiles of different mycoplasmas are generally species-specific; however, several pathogenic species share certain biologic properties and/or virulence factors. We compared species of human, avian and animal origin to determine if there was evidence for conservation of key antigens. Log-phase cultures of Mycoplasma pneumoniae, M.

Serological comparison of virulent and avirulent Mycoplasma pneumoniae by monoclonal antibodies.

An avirulent strain (M129-B175) of Mycoplasma pneumoniae is morphologically indistinguishable from its virulent parent strain (M129-B7). Functionally, the avirulent strain has lost its ability to attach to respiratory epithelium and does not produce pneumonia in hamsters. Biochemical analyses by one- or two-dimensional SDS-gel electrophoresis have so far failed to produce evidence that could account for the changes in the avirulent strain.

A new animal model for human respiratory tract disease due to adenovirus.

Cotton rats (Sigmodon hispidus) were tested as a model for human respiratory tract infection due to adenovirus. After intranasal instillation of 10(6.1) 50% tissue culture infectious doses (TCID50) of adenovirus type 5 into one-month-old cotton rats, groups were killed at intervals for nasal and lung titration of virus and lung histopathology.

Mycoplasma pneumoniae infections of man: integration of attachment mechanism, cellular responses and clinical manifestations.

Research advances of recent years are permitting new understanding of M. pneumoniae disease pathogenesis, although our knowledge remains incomplete. Colonization of the respiratory tract mucosa, mediated by an attachment protein, leads to specialized cell injury and altered muco-ciliary clearance.

Mycoplasma pneumoniae respiratory disease symposium: summation and significance.

The symposium on M. pneumoniae respiratory disease has examined the clinical expression of infection in adults and children, the pathophysiologic disturbances which occur, and the laboratory diagnosis by isolation and serology. That these infections are very common has been well documented; however, a variable incidence over periods of several years tends to minimize importance of the disease for many clinicians.

Location of attachment moiety on Mycoplasma pneumoniae.

Mycoplasma pneumoniae initiates infection in the human host by attachment to respiratory epithelium. The organism attaches by a specialized terminal structure. Monoclonal antibodies to an organism surface protein (P1) inhibited attachment to respiratory epithelium and were localized to the tip structure by a ferritin antibody label.