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Dive into the research topics where Michael A. Schillaci is active.

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Featured researches published by Michael A. Schillaci.


Emerging Infectious Diseases | 2005

Primate-to-human retroviral transmission in Asia.

Lisa Jones-Engel; Gregory A. Engel; Michael A. Schillaci; Aida Rompis; Artha Putra; Komang Gde Suaryana; Agustin Fuentes; Brigitte Beer; Sarah Hicks; Robert White; Brenda Wilson; Jonathan S. Allan

We describe the first reported transmission to a human of simian foamy virus (SFV) from a free-ranging population of nonhuman primates in Asia. The transmission of an exogenous retrovirus, SFV, from macaques (Macaca fascicularis) to a human at a monkey temple in Bali, Indonesia, was investigated with molecular and serologic techniques. Antibodies to SFV were detected by Western blotting of serum from 1 of 82 humans tested. SFV DNA was detected by nested polymerase chain reaction (PCR) from the blood of the same person. Cloning and sequencing of PCR products confirmed the viruss close phylogenetic relationship to SFV isolated from macaques at the same temple. This study raises concerns that persons who work at or live around monkey temples are at risk for infection with SFV.


Emerging Infectious Diseases | 2008

Diverse Contexts of Zoonotic Transmission of Simian Foamy Viruses in Asia

Lisa Jones-Engel; Cynthia May; Gregory A. Engel; Katherine A. Steinkraus; Michael A. Schillaci; Agustin Fuentes; Aida Rompis; Mukesh Kumar Chalise; Nantiya Aggimarangsee; Mohammed Mostafa Feeroz; Richard Grant; Jonathan S. Allan; Arta Putra; I Nengah Wandia; Robin Watanabe; LaRene Kuller; Satawat Thongsawat; Romanee Chaiwarith; Randall C. Kyes; Maxine L. Linial

These infections are likely prevalent among persons who live or work near nonhuman primates.


Emerging Infectious Diseases | 2002

Human Exposure to Herpesvirus B–Seropositive Macaques, Bali, Indonesia

Gregory A. Engel; Lisa Jones-Engel; Michael A. Schillaci; Komang Gde Suaryana; Artha Putra; Agustin Fuentes; Richard Henkel

Herpesvirus B (Cercopithecine herpesvirus 1) has been implicated as the cause of approximately 40 cases of meningoencephalitis affecting persons in direct or indirect contact with laboratory macaques. However, the threat of herpesvirus B in nonlaboratory settings worldwide remains to be addressed. We investigated the potential for exposure to herpesvirus B in workers at a “monkey forest” (a temple that has become a tourist attraction because of its monkeys) in Bali, Indonesia. In July 2000, 105 workers at the Sangeh Monkey Forest in Central Bali were surveyed about contact with macaques (Macaca fascicularis). Nearly half of those interviewed had either been bitten or scratched by a macaque. Prevalence of injury was higher in those who fed macaques. Serum from 31 of 38 Sangeh macaques contained antibodies to herpesvirus B. We conclude that workers coming into contact with macaques at the Sangeh Monkey Forest are at risk for exposure to herpesvirus B.


American Journal of Physical Anthropology | 2008

Greater sciatic notch as a sex indicator in juveniles.

Dejana Vlak; Mirjana Roksandic; Michael A. Schillaci

Using Schutkowskis method for juvenile sex determination (Schutkowski H. 1993. Am J Phys Anthropol 90:199-205), we evaluated the morphology of the greater sciatic notch of 56 ilia (23 females and 33 males) from a documented skeletal collection housed at the Bocage Museum in Lisbon (Portugal). After applying Schutkowskis original methodology and comparing the results with previous studies, we used age-adjusted metrical variables to describe greater sciatic notch depth, breadth, and angle. Although results of both morphological and metrical analyses did not reveal a statistically significant level of sexual analyses dimorphism, we found a strong correlation between pelvic morphology and age at death. On the basis of the obtained results, we argue that Schutkowskis morphological method does not predict sex accurately in all populations and that recorded correlation of iliac features with age needs to be further explored in the context of the ontogeny of sexual dimorphism.


Journal of Virology | 2007

Sensitive Assays for Simian Foamy Viruses Reveal a High Prevalence of Infection in Commensal, Free-Ranging Asian Monkeys

Lisa Jones-Engel; Katherine A Steinkraus; Shannon Marie Murray; Gregory A. Engel; Richard Grant; Nantiya Aggimarangsee; Benjamin P. Y-H. Lee; Cynthia May; Michael A. Schillaci; Chaleamchat Somgird; Tulyawat Sutthipat; Lucia Vojtech; JianYuan Zhao; Maxine L. Linial

ABSTRACT Foamy viruses (FV) are retroviruses that naturally infect many hosts, including most nonhuman primates (NHPs). Zoonotic infection by primate FV has been documented in people in Asia who reported contact with free-ranging macaques. FV transmission in Asia is a concern, given abundant human-NHP contact, particularly at monkey temples and in urban settings. We have developed three assays capable of detecting the presence of FV in Asian NHP species that are commensal with humans: enzyme-linked immunosorbent assay (ELISA), Western blot assays using recombinant viral Gag protein, and an indicator cell line that can detect macaque FV. The recombinant ELISA correlates very well with the presence of FV sequences detected by PCR. We have used these assays to demonstrate both that FV is highly prevalent among free-ranging NHPs and that seroconversion occurs at a young age in these animals. These assays should also prove useful for large-scale analysis of the prevalence of FV infections in human populations in Asia that are commensal with free-ranging NHPs.


PLOS ONE | 2006

Sexual Selection and the Evolution of Brain Size in Primates

Michael A. Schillaci

Reproductive competition among males has long been considered a powerful force in the evolution of primates. The evolution of brain size and complexity in the Order Primates has been widely regarded as the hallmark of primate evolutionary history. Despite their importance to our understanding of primate evolution, the relationship between sexual selection and the evolutionary development of brain size is not well studied. The present research examines the evolutionary relationship between brain size and two components of primate sexual selection, sperm competition and male competition for mates. Results indicate that there is not a significant relationship between relative brain size and sperm competition as measured by relative testis size in primates, suggesting sperm competition has not played an important role in the evolution of brain size in the primate order. There is, however, a significant negative evolutionary relationship between relative brain size and the level of male competition for mates. The present study shows that the largest relative brain sizes among primate species are associated with monogamous mating systems, suggesting primate monogamy may require greater social acuity and abilities of deception.


Tropical Medicine & International Health | 2005

Prevalence of enzootic simian viruses among urban performance monkeys in Indonesia

Michael A. Schillaci; Lisa Jones-Engel; Gregory A. Engel; Yasmina Paramastri; Entang Iskandar; Brenda Wilson; Jonathan S. Allan; Randall C. Kyes; Robin Watanabe; Richard Grant

Animal reservoirs are the most important sources of emerging infectious diseases that threaten human populations. Global travel and tourism bring ever‐increasing numbers of humans into contact with animals, increasing the likelihood of cross species transmission of infectious agents. Non‐human primates come into contact with humans in a variety of contexts and may harbor infectious agents with zoonotic potential. We investigated the prevalence of infection with enzootic simian viruses among 20 urban performance monkeys (Macaca fascicularis) in Jakarta, Indonesia. This report documents for the first time evidence of infection with four simian viruses in urban performance monkeys. Simian foamy virus was detected by PCR in 52.9% of the macaques. Antibodies to simian retrovirus were detected in 10.5% of the macaques. Antibodies to Cercopithecine Herpesvirus 1, were detected in 5.3% of the macaques. Similarly, antibodies to simian T‐cell lymphotropic virus were detected in 5.3% of the macaques. No evidence of infection with simian immunodeficiency virus was detected in these macaques. These results suggest that urban performance monkeys are a reservoir for enzootic simian viruses known to be capable of infecting humans.


Journal of Human Evolution | 2008

Human cranial diversity and evidence for an ancient lineage of modern humans.

Michael A. Schillaci

This study examines the genetic affinities of various modern human groupings using a multivariate analysis of morphometric data. Phylogenetic relationships among these groupings are also explored using neighbor-joining analysis of the metric data. Results indicate that the terminal Pleistocene/early Holocene fossils from Australasia exhibit a close genetic affinity with early modern humans from the Levant. Furthermore, recent human populations and Upper Paleolithic Europeans share a most recent common ancestor not shared with either the early Australasians or the early Levantine humans. This pattern of genetic and phylogenetic relationships suggests that the early modern humans from the Levant either contributed directly to the ancestry of an early lineage of Australasians, or that they share a recent common ancestor with them. The principal findings of the study, therefore, lend support to the notion of an early dispersal from Africa by a more ancient lineage of modern human prior to 50 ka, perhaps as early as OIS 5 times (76-100 ka).


PLOS ONE | 2012

The origin of malarial parasites in orangutans.

M. Andreína Pacheco; Michael J.C. Reid; Michael A. Schillaci; Carl Lowenberger; Biruté M. F. Galdikas; Lisa Jones-Engel; Ananias A. Escalante

Background Recent findings of Plasmodium in African apes have changed our perspectives on the evolution of malarial parasites in hominids. However, phylogenetic analyses of primate malarias are still missing information from Southeast Asian apes. In this study, we report molecular data for a malaria parasite lineage found in orangutans. Methodology/Principal Findings We screened twenty-four blood samples from Pongo pygmaeus (Kalimantan, Indonesia) for Plasmodium parasites by PCR. For all the malaria positive orangutan samples, parasite mitochondrial genomes (mtDNA) and two antigens: merozoite surface protein 1 42 kDa (MSP-142) and circumsporozoite protein gene (CSP) were amplified, cloned, and sequenced. Fifteen orangutans tested positive and yielded 5 distinct mitochondrial haplotypes not previously found. The haplotypes detected exhibited low genetic divergence among them, indicating that they belong to one species. We report phylogenetic analyses using mitochondrial genomes, MSP-142 and CSP. We found that the orangutan malaria parasite lineage was part of a monophyletic group that includes all the known non-human primate malaria parasites found in Southeast Asia; specifically, it shares a recent common ancestor with P. inui (a macaque parasite) and P. hylobati (a gibbon parasite) suggesting that this lineage originated as a result of a host switch. The genetic diversity of MSP-142 in orangutans seems to be under negative selection. This result is similar to previous findings in non-human primate malarias closely related to P. vivax. As has been previously observed in the other Plasmodium species found in non-human primates, the CSP shows high polymorphism in the number of repeats. However, it has clearly distinctive motifs from those previously found in other malarial parasites. Conclusion The evidence available from Asian apes indicates that these parasites originated independently from those found in Africa, likely as the result of host switches from other non-human primates.


American Journal of Physical Anthropology | 2009

Technical note: Applicability of tooth cementum annulation to an archaeological population.

Mirjana Roksandic; Dejana Vlak; Michael A. Schillaci; Diana Voicu

The use of tooth cementum annulations for age determination has been deemed promising, exhibiting high correlations with chronological age. Despite its apparent potential, to date, the tooth cementum annulations method has been used rarely for estimating ages in archaeological populations. Here we examine the readability of cementum annulations and the consistency of age estimates using a sample of 116 adults from the Iron Gates Gorge Mesolithic/Neolithic series. Our examination of the method pointed to several sources of error that call into question the use of this method for estimating the chronological ages of archaeologically derived dental samples. The poor performance of the method in our analysis might be explained by taphonomic influences, including the effect of chemical and biological agents on dental microstructures.

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Richard Grant

University of Washington

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