An early modern human presence in Sumatra 73,000-63,000 years ago.

Genetic evidence for anatomically modern humans (AMH) out of Africa before 75 thousand years ago (ka) and in island southeast Asia (ISEA) before 60 ka (93-61 ka) predates accepted archaeological records of occupation in the region. Claims that AMH arrived in ISEA before 60 ka (ref. 4) have been supported only by equivocal or non-skeletal evidence. AMH evidence from this period is rare and lacks robust chronologies owing to a lack of direct dating applications, poor preservation and/or excavation strategies and questionable taxonomic identifications. Lida Ajer is a Sumatran Pleistocene cave with a rich rainforest fauna associated with fossil human teeth. The importance of the site is unclear owing to unsupported taxonomic identification of these fossils and uncertainties regarding the age of the deposit, therefore it is rarely considered in models of human dispersal. Here we reinvestigate Lida Ajer to identify the teeth confidently and establish a robust chronology using an integrated dating approach. Using enamel-dentine junction morphology, enamel thickness and comparative morphology, we show that the teeth are unequivocally AMH. Luminescence and uranium-series techniques applied to bone-bearing sediments and speleothems, and coupled uranium-series and electron spin resonance dating of mammalian teeth, place modern humans in Sumatra between 73 and 63 ka. This age is consistent with biostratigraphic estimations, palaeoclimate and sea-level reconstructions, and genetic evidence for a pre-60 ka arrival of AMH into ISEA. Lida Ajer represents, to our knowledge, the earliest evidence of rainforest occupation by AMH, and underscores the importance of reassessing the timing and environmental context of the dispersal of modern humans out of Africa.

Chlamydia trachomatis laboratory strains versus recent clinical isolates: implications for routine microbicide testing.

A topical microbicide that women can use to prevent sexually transmitted diseases (STDs) is essential, and many microbicide candidates are being tested for activity against human immunodeficiency virus and other STDs, including Chlamydia trachomatis. Screening assays for assessing the activity of microbicides against C. trachomatis are typically done with laboratory-adapted strains, but it is possible that recent clinical isolates may have different susceptibilities to microbicides, as has been seen with Neisseria gonorrhoeae and Lactobacillus spp. (B. J. Moncla and S. L. Hillier, Sex. Transm. Dis. 32:491-494, 2005). We utilized three types of microbicides to help define this aspect of our assay to test microbicides against C. trachomatis in vitro. To simulate conditions of transmission, we used an assay that we previously developed in which we exposed chlamydial elementary bodies to microbicides prior to contact with epithelial cells. We first determined the toxicity of microbicides to the cells used to culture Chlamydia trachomatis in the assay and, if necessary, modified the assay to eliminate toxicity at the concentrations tested. We compared the sensitivities of recent clinical isolates of Chlamydia trachomatis versus laboratory strains of the same serovar and found major differences in sensitivity to nonoxynol-9 (non-9), but only minor differences were seen with the other microbicides. We thus conclude that when assessing activity of potential topical microbicides versus the obligate intracellular bacteria C. trachomatis, the use of recent clinical isolates may not be necessary to draw a conclusion about a microbicide's effectiveness. However, it is important to keep in mind that differences (like those seen with non-9) are possible and that clinical isolates could be included in later stages of testing.

Prevention of activated neutrophil adhesion to endothelium by soluble adhesion protein GMP140.

Neutrophils and monocytes, but not lymphocytes, adhered strongly to plastic surfaces coated with GMP140, a protein of endothelial cells and platelets. This adhesion of neutrophils was mediated by GMP140 and not by the CD18 integrin complex. By contrast, GMP140 in solution inhibited the CD18-dependent adhesion of tumor necrosis factor-alpha-activated neutrophils to plastic surfaces and resting endothelium, but not of resting neutrophils to tumor necrosis factor-alpha-activated endothelium. Thus, the binding of a soluble form of an adhesion protein selectively inhibited another set of adhesive events. Soluble GMP140 may be important in maintaining the nonadhesiveness of neutrophils in the circulation and may serve to limit inflammatory reactions.

Consumption of apple-boysenberry beverage decreases salivary Actinomyces naeslundii and their adhesion in a multi-species biofilm model.

We hypothesised that consumption of beverage rich in both fibre and polyphenols, rather than each bioactive alone, will modulate populations of selected salivary bacteria, and their adhesion characteristics and that some of these effects may be due to the anti-microbial activity of the beverage bioactives. We investigated the effect of 4 weeks' consumption of beverages, rich in apple fibre, boysenberry polyphenols, or both on salivary bacteria in healthy subjects. In this placebo-controlled crossover study, saliva samples were collected at the beginning and end of each treatment period, and used for qPCR quantitation of Lactobacillus spp., Actinomyces naeslundii and Streptococcus mutans. The counts of salivary A. naeslundii decreased after the consumption of the apple-boysenberry beverage (P<0.05, Student's t-test). We also examined the effect of the subjects' saliva on bacterial adhesion using a mixed species biofilm model. The salivary pellicles prepared before and after each treatment were inoculated with laboratory strains of A. naeslundii, Lactobacillus rhamnosus and S. mutans and tested for biofilm formation. The post appleboysenberry beverage salivary pellicle significantly decreased the adhesion of A. naeslundii at the end of both 3 and 24 h, in the in vitro biofilm. A 1/16 dilution of the apple-boysenberry beverage itself decreased the proliferation of test strains of A. naeslundii and S. mutans by 51 and 55%, respectively (P<0.005), indicating the antimicrobial activity of its bioactives. This study demonstrated that consumption of apple-boysenberry beverage, rather than apple or the boysenberry beverage alone or the placebo, decreased salivary A. naeslundii and their adhesion under laboratory conditions. These changes are factors that influence oral microecology and potentially oral health.

Use of abdominal fat tissue aspirate in the diagnosis of systemic amyloidosis.

The needle aspirate of abdominal fat was investigated for its sensitivity in giving a tissue diagnosis in 32 consecutive patients with systemic amyloidosis. The fat tissue aspirate was stained with Congo red and examined with a polarizing microscope. Positive results were obtained in 95% (18/19) of patients with primary (AL) amyloidosis, 66% (4/6) of patients with secondary (AA) amyloidosis, and 86% (6/7) of patients with the heredofamilial (AF) form. The overall positive yield was 88% (28/32). Abdominal fat tissue aspiration is proposed as a simple, rapid, and effective technique for the diagnosis of amyloidosis. The prevalence of positive results in known amyloid disease are comparable with the rectal biopsy specimen and are more frequent than gingival or skin biopsy specimens.

Isolation of tooth pulp cells for sex chromatin studies in experimental dehydrated and cremated remains.

In experiments designed to assess sex chromatin in artificially mummified and heated pulp tissue, a method was devised that successfully separates cells while minimizing nuclear damage. Sex chromatin (both Barr bodies and F-bodies) is shown to preserve in dehydrated human pulps up to one year. Human pulp tissue retains sex diagnostic characteristics when heated to 100 degrees C for up to 1 h. Parallel experiments on extracted teeth from young pigs reveals comparable tissue preservation. Heat penetration is retarded, however, in unextracted pig teeth in fleshed jaws such that temperatures could be raised to 300 degrees C for longer than 1 h. Heat penetration into fleshed material was further tested by the insertion of thermocouple probes to assess the temperature attained within the pulp chamber. At chamber temperatures up to 75 degrees C sex diagnosis in human pulps from extracted teeth was still possible. In outdoor incineration of fleshed pigs' heads in an open fire, 75 degrees C in the pulp chamber was reached at a fire temperature within the range 500-700 degrees C. The implications of these findings for forensic situations are described.

Routine insertion of a silastic spring-loaded silo for infants with gastroschisis.

BACKGROUND/PURPOSE: Gastroschisis traditionally is managed by emergency operating room closure (EC), with a silo reserved for cases that cannot be closed primarily. The authors recently began using routine insertion of a SILASTIC (Dow Corning, Midland, MI) spring-loaded silo (SLS), followed by elective closure. METHODS: A total of 43 consecutive neonates with gastroschisis were treated between 1993 and 1998. RESULTS: Thirty patients underwent EC, and 13 underwent closure after insertion of a SLS (10 at bedside, 3 in the operating room). Eight infants treated by EC required staged repair. There were no differences with respect to gestational age, birth weight, gender, Apgar score, maternal age, or mode of delivery. Median length of stay was 32 days for EC and 25 days for SLS (P = .05). The SLS group required fewer days on a ventilator (4 v 6 days, P = .03) and had lower intraoperative (28 v 21, P = .02) and early postoperative peak airway pressures. The time to tolerate full feedings was 21 days for SLS and 27 days for EC (P = .07). The SLS group had fewer complications and a lower median hospital charge ($71,498 v $85,147; P = .05). CONCLUSION: SLS followed by elective repair permits gentle, gradual reduction of the viscera. When compared with EC, SLS is associated with significantly lower airway pressures, earlier extubation, fewer complications, and decreased length of stay and hospital charges.

Localized amyloidosis of the head and neck and upper aerodigestive and lower respiratory tracts.

Seven cases of localized amyloidosis limited to structures of the head and neck and upper aerodigestive and lower respiratory tracts evaluated and treated at Boston University Hospitals in a recent 7-year period were reviewed. Negative Congo red staining of abdominal adipose aspiration biopsy or rectal biopsy specimens established that the amyloidosis was not systemic. Localized amyloidosis occurred in discrete masses in a variety of sites in the aerodigestive tract including the orbit, nasopharynx, lips, floor of mouth, tongue, larynx, and tracheobronchial tree. Five patients required surgical excision because of significant airway obstruction or organic dysfunction. Amyloid deposits completely excised with the carbon dioxide laser have not recurred, though other amyloid masses may appear elsewhere within the same organ or region. Amyloidosis may occur primarily or secondarily to other disease states. Localized amyloidosis has not been chemically identified but is usually defined by the absence of systemic features. While rare, amyloidosis must be recognized and understood by the otolaryngologist/head and neck surgeon to allow appropriate diagnostic and therapeutic planning.

Matrigel-coated stents reduce intimal thickening in a large animal vascular stent model.

BACKGROUND: Restenosis within vascular stents is primarily due to intimal thickening secondary to intimal hyperplasia (IH) which occurs maximally around stent struts. Dedifferentiation of vascular smooth muscle cells (VSMC) with subsequent migration and proliferation is believed to be a key event in IH formation. Matrigel (basement membrane protein) has been shown to inhibit dedifferentiation of VSMC in vitro. Our aim was to test the in vivo effect of Matrigel on IH formation using a novel sheep vascular stent model. METHODS: Twenty vascular stents were implanted in the renal arteries of ten sheep. The left renal artery of each sheep was used to deploy uncoated stent and the right renal artery was used to deploy Matrigel-coated stent. Five sheep were analysed at four weeks and five at eight weeks after stent implantation. The sheep were sacrificed at the end of the study periods and the stented renal artery segments were examined by histology. Luminal, intimal and medial areas were determined using computer-assisted morphometric analysis. RESULTS: All stent sites were widely patent without thrombosis. No luminal stenosis was seen angiographically. IH was quantified from histology cross-sections and expressed as an intima to media (I/M) ratio. The ratio was significantly reduced in the matrigel-coated sites at eight weeks (uncoated 0.49+/-0.23; Matrigel-coated 0.32+/-0.12; p value <0.05). CONCLUSIONS: The sheep renal artery vascular stent model is feasible for the study of stent biology. IH was reduced by Matrigel-coated stents.

Variation in birth timing and location of the neonatal line in human enamel.

The location of the neonatal line in 173 primary teeth from 43 children was investigated and shown to differ significantly among pre-term, term, and post-term births. Approximately 75% of the neonatal lines that lie beyond 2SD of the mean location of the line in term births are from children born outside of 38 to 42 weeks gestation. The duration of pregnancy accounts for about 36% of the variation in location of the neonatal line in non-term births. Based on the small proportion of non-term births whose neonatal line is located beyond 2SD of the mean location of the neonatal line in term births, it is estimated that this technique will provide individualizing information in about 3% of immature skeletonized remains in a forensic context. The relative timing of pre- and postnatal pathological striae in the enamel of primary teeth can be evaluated in terms of the variation, documented here, in the location of the neonatal line due to individual and birth timing differences. Determination of the timing of pathological enamel striae will aid in the identification of both children and adults for whom histological examination of enamel is undertaken.

Individualization and enamel histology: a case report in forensic anthropology.

The cranium of a native Indian child about six years old was found in 1979 near Taseko River, British Columbia, Canada. While the remains matched the report of a child missing for eight years in terms of race, age at death, locale, and elapsed time since death, the cranium and dentition were basically unidentifiable because of the claimed lack of medical or dental history. There was no dental work, and the parents were unknown or dead. We report the presence, in the dental enamel of the primary and secondary dentition, of stress markers, termed striae of Retzius, whose locations correspond well with anecdotal reports and recently discovered medical records which describe the timing of specific episodes of stress. The enhanced probability of personal identification from dental histological stress markers is evaluated.

Rates of putrefaction of dental pulp in the Northwest coast environment.

Cytological stability is of interest to criminal investigators in instances where remnants of soft tissue have been preserved, since such tissue can aid in the identification of human remains, helping to determine either the sex of the individual or his or her identity. This study based on seven experiments shows that, in Northwest coast outdoor environments in both summer (three experiments) and winter (three experiments), the stability of dental pulp nuclei ranges from 4 days to 2 weeks. The seventh experiment serves to describe the morphological sequence observed in nuclear putrefaction. The specimens included human and pig extracted teeth and unextracted pig teeth. Deposition of the specimens was made both on the surface and in the subsurface (30-cm depth), and the environmental variables were recorded.

Three-dimensional molar enamel distribution and thickness in Australopithecus and Paranthropus.

Thick molar enamel is among the few diagnostic characters of hominins which are measurable in fossil specimens. Despite a long history of study and characterization of Paranthropus molars as relatively 'hyper-thick', only a few tooth fragments and controlled planes of section (designed to be proxies of whole-crown thickness) have been measured. Here, we measure molar enamel thickness in Australopithecus africanus and Paranthropus robustus using accurate microtomographic methods, recording the whole-crown distribution of enamel. Both taxa have relatively thick enamel, but are thinner than previously characterized based on two-dimensional measurements. Three-dimensional measurements show that P. robustus enamel is not hyper-thick, and A. africanus enamel is relatively thinner than that of recent humans. Interspecific differences in the whole-crown distribution of enamel thickness influence cross-sectional measurements such that enamel thickness is exaggerated in two-dimensional sections of A. africanus and P. robustus molars. As such, two-dimensional enamel thickness measurements in australopiths are not reliable proxies for the three-dimensional data they are meant to represent. The three-dimensional distribution of enamel thickness shows different patterns among species, and is more useful for the interpretation of functional adaptations than single summary measures of enamel thickness.

An enigmatic hypoplastic defect of the deciduous canine.

A roughly circular hypoplastic defect restricted to the labial enamel surface of the deciduous canine is described. This pathology is quite common in available samples of Upper Paleolithic and Neolithic children and a cadaver sample of recent Calcuttans, affecting 44% to 70% of individuals. It is rare in a Neanderthal sample and in children from a clinical practice in Vancouver. The lesion occurs twice as commonly in the lower jaw. The defect appears to commence at or after birth owing to localized pressure on thin or nonexistent alveolar bone overlying the bulging crypt of the deciduous canine. Population differences in the incidence of the pathology probably reflect innate and acquired variation in hard and soft tissue thicknesses in this region.

A re-evaluation of localized hypoplasia of the primary canine as a marker of craniofacial osteopenia in European Upper Paleolithic infants.

Localized hypoplasia of the primary canine (LHPC) occurs in prehistoric and contemporary populations with prevalence varying from 0 to 89%. One of the highest prevalences ever reported is Upper Paleolithic infants from Europe where 70% are affected. In that LHPC is found in relatively high proportions of contemporary children with reported or suspected malnutrition, it is important to investigate the etiology of LHPC. Previous research indicates that LHPC occurs in two steps: craniofacial osteopenia results in temporary fenestration of the cortical bone overlying the primary canine crypt; secondly, minor physical trauma to the perioral region impacts on the unprotected forming tooth crown resulting in a small pit visible on the labial surface of the erupted tooth. Investigation of the prenatal diet of mothers whose children are shown later to have LHPC found mothers are significantly low in vitamin A. Hitherto an animal model for this problem has been lacking. Recently Newell and Skinner have recognized that LHPC occurs very commonly in orangutans. Recent study of infant jaws from Pongo pygmaeus (n=75) and Pan paniscus (n=39) shows all stages of fenestration and healing of the labial bone of the primary canine crypt. 85% of orangutan and 62% of bonobos show LHPC. Current research is directed at bioavailability of vitamin A to ape infants. LHPC is a marker of malnutrition; a common factor that could link orangutan and Upper Paleolithic mothers is low dietary fat intake. A minimal level of dietary fat is required for gut absorption of both vitamin A and carotenoids.

Prevalence and etiology of linear enamel hypoplasia in monkeys and apes from Asia and Africa.

Ninety-seven specimens of sympatric monkeys and apes from East Malaysia and 115 monkeys and apes from West Africa are examined in order to evaluate the magnitude and nature of the great ape-monkey linear enamel hypoplasia (LEH) 'dichotomy'. This study demonstrates that great apes from both regions have a higher incidence of LEH and repetitive LEH than do gibbons and monkeys. However, the authors find that the dichotomy is not as clear-cut as previous research suggests, since some monkey samples exhibit high LEH frequencies. The authors evaluate the potential influence of great ape-monkey differences in crown height on this dichotomy. They show that canine crown height variation is weakly associated with LEH variation. Differences between monkeys and great apes in their crown formation spans and in their experience of environmental stress may be more likely causes of the dichotomy.

Social and biological correlates of localized enamel hypoplasia of the human deciduous canine tooth.

Recent studies of teeth from prehistoric children have reported a localized, roughly circular patch of deficient enamel on the labial aspect of the primary canine, which reaches its highest prevalence in the Upper Paleolithic of Europe. This study reports social and biological correlates of 33 affected kindergarten-aged children from Vancouver, Canada (2.4% of 1,350 examined). Affected children can be characterized as coming from low-income families often of East Asian or Chinese origin in which there is a degree of milk avoidance and reduced breastfeeding. The defect appears to be due to minor physical trauma to the face approximately 6 months after birth occasioned by normal motor development, involving handling and mouthing objects, which damages the developing tooth crown through deficient cortical bone over the canine crypt. Reduced cortical bone in the face of the infant is attributed to nutritional factors, involving calcium deficiency, of the mother and/or developing infant.