Absence of the lactase-persistence-associated allele in early Neolithic Europeans

Lactase persistence (LP), the dominant Mendelian trait conferring the ability to digest the milk sugar lactose in adults, has risen to high frequency in central and northern Europeans in the last 20,000 years. This trait is likely to have conferred a selective advantage in individuals who consume appreciable amounts of unfermented milk. Some have argued for the "culture-historical hypothesis," whereby LP alleles were rare until the advent of dairying early in the Neolithic but then rose rapidly in frequency under natural selection. Others favor the "reverse cause hypothesis," whereby dairying was adopted in populations with preadaptive high LP allele frequencies. Analysis based on the conservation of lactase gene haplotypes indicates a recent origin and high selection coefficients for LP, although it has not been possible to say whether early Neolithic European populations were lactase persistent at appreciable frequencies. We developed a stepwise strategy for obtaining reliable nuclear ancient DNA from ancient skeletons, based on (i) the selection of skeletons from archaeological sites that showed excellent biomolecular preservation, (ii) obtaining highly reproducible human mitochondrial DNA sequences, and (iii) reliable short tandem repeat (STR) genotypes from the same specimens. By applying this experimental strategy, we have obtained high-confidence LP-associated genotypes from eight Neolithic and one Mesolithic human remains, using a range of strict criteria for ancient DNA work. We did not observe the allele most commonly associated with LP in Europeans, thus providing evidence for the culture-historical hypothesis, and indicating that LP was rare in early European farmers.

Early history of European domestic cattle as revealed by ancient DNA

We present an extensive ancient DNA analysis of mainly Neolithic cattle bones sampled from archaeological sites along the route of Neolithic expansion, from Turkey to North-Central Europe and Britain. We place this first reasonable population sample of Neolithic cattle mitochondrial DNA sequence diversity in context to illustrate the continuity of haplotype variation patterns from the first European domestic cattle to the present. Interestingly, the dominant Central European pattern, a starburst phylogeny around the modal sequence, T3, has a Neolithic origin, and the reduced diversity within this cluster in the ancient samples accords with their shorter history of post-domestic accumulation of mutation.

Element levels in snakes in South Carolina: differences between a control site and exposed site on the Savannah River site

Levels of 18 elements, including lead, mercury, selenium, and uranium, were examined in three species of snakes from an exposed and reference site on the Department of Energy's Savannah River Site in South Carolina. We tested the hypotheses that there were no differences as a function of species, and there were no difference between the exposed and control site for blood and muscle (tail) samples for banded water snake (Nerodia fasciata), brown water snake (N. taxispilota) and cotton mouth (Akistrodon piscivorous). The banded water snakes collected were significantly smaller than the other two species. For blood, there were significant species differences only for barium, copper, selenium, uranium and zinc, while for muscle tissue there were significant interspecific differences in aluminum, arsenic, barium, cobalt, cesium, copper, iron, lead, mercury, manganese, strontium, vanadium and zinc, suggesting that muscle tissue in the tail is a better indicator of potential interspecific differences. It is also easier logistically to collect tail tissue than blood. Where one species had significantly higher levels than the other species in muscle tissue levels, cottonmouth had higher levels of five elements (aluminum, cobalt, lead, mercury, vanadium), brown water snake had two (lead, strontium), and banded water snake had only barium. There were few significant differences between the control and reference site for levels of blood, but several for muscle tissue. All three species had significantly higher levels of arsenic and manganese at Tim's Branch than the reference site, and nickel and uranium were significantly higher for banded water snake and cotton mouth, the larger species. Individuals with high exposure of one element were exposed to high levels of other elements.

Heavy metal concentrations in northern water snakes (Nerodia sipedon) from East Fork Poplar Creek and the Little River, East Tennessee, USA

We compared the levels of arsenic, cadmium, chromium, lead, manganese, mercury, and selenium in the blood, kidney, liver, muscle, and skin of northern water snakes (Nerodia sipedon) collected from the upper reach of East Fork Poplar Creek (EFPC) within the United States Department of Energy's (USDOE's) Y-12 National Security Complex with concentrations in tissues of northern water snakes from a reference reach of the Little River downstream from the Great Smoky Mountains National Park in East Tennessee. Our objectives were to determine whether concentrations of these metals were higher in tissues of water snakes collected from EFPC compared with the reference site and if northern water snakes were suitable bioindicators of metal contamination. Except for chromium, metal levels were significantly higher in tissues (kidney, liver, muscle, and skin) of EFPC northern water snakes compared with those in tissues of snakes from the reference site. Although female northern water snakes were significantly larger than male snakes, their tissues did not contain significantly higher metal concentrations compared with those from male snakes, possibly because of maternal transfer of metals to eggs. This study was the first to examine the accumulation of contaminants resulting from the operations of the USDOE's Oak Ridge Reservation in snakes.

Use of skin and blood as nonlethal indicators of heavy metal contamination in northern water snakes (Nerodia sipedon)

Relatively little is known about contaminants in reptiles, particularly snakes. The concentrations of arsenic, cadmium, chromium, lead, manganese, mercury, and selenium were examined in blood and skin of 46 northern water snakes (Nerodia sipedon) in Tennessee and correlated with concentrations in internal tissues (liver, kidney, muscle) to determine if blood or skin could serve as a nonlethal indicator of internal metal exposure or body burden. Snakes were collected from the East Fork Poplar Creek (EFPC) within the United States Department of Energy's Y-12 National Security Complex (part of the Oak Ridge National Laboratory) and from a reference stretch of the Little River in East Tennessee. For blood, the only consistent positive correlations with internal organs were for mercury, and correlations were low except for muscle. Skin showed significant positive correlations with all three organs for mercury, chromium, selenium, and lead. For manganese and cadmium, skin level was positively correlated with liver level. Blood generally reflects recent exposure, not necessarily body burden, but in water snakes it correlates with body burden for mercury. Skin proved useful for more metals, although patterns were not necessarily consistent across sex and locality subgroups. The most consistent pattern was for mercury, the metal of greatest concern in many aquatic ecosystems, including EFPC.

Beidseitige Oberlidschwellung bei Mononucleosis Infectiosa (Hoagland-Zeichen)

BACKGROUND

Infectious mononucleosis ("kissing disease") is an infection caused by Epstein-Barr-Virus (EBV, human herpes virus 4).

METHODS

We present the case of an 18-year old female patient with dacryoadenitis and sub-febrile temperatures followed by a distinct feeling of sickness.

RESULTS

Laboratory results revealed a Leukocytosis of 16.3 G/I with explicit elevation of hepatic parameters. The ultrasound scan of the orbital region showed a bilateral, echo-reduced, compressible lesion in the area of the lachrymal gland. The abdomen-ultrasound scan revealed a splenomegaly and the size of the liver was within normal limits. Serology was positive for EBV-VCA-IgG, EBV-EA-IgG and EBV-VCA-IgM.

CONCLUSIONS

A dacryoadenitis can be the presenting symptom of an infectious mononucleosis.

Perceptions of recreational fishing boat captains: knowledge and effects of fish consumption advisories

The impacts of fish consumption advisories on recreational and subsistence fishing, particularly in fresh waters, have been examined extensively. By contrast, little attention has focused on organized recreational fishing, such as from party and charter boats, and particularly for salt water fish. We interviewed 93 New Jersey boat captains to determine their knowledge about fish consumption advisories, and whether, in their opinion, clients knew of fish consumption advisories, and whether they thought advisories had an effect on recreational fishing and their businesses. Advisories were ranked by captains as a moderate influence on the success of their business, less so than number of fish caught, strength of the economy, overfishing by commercial boats, and management regulations. Only one boat captain had not heard warnings about eating fish, but what captains said they had heard was mixed in its accuracy and completeness. Clients expect captains to know about fish, and about half of boat captains said clients had asked about the safety of eating fish. Captains who felt advisories were affecting their businesses tended to fish for species without high levels of mercury (except for bluefish) or PCBs, the primary contaminants of concern for state advisories and federal advice. However, these captains worked closer to areas (e.g., Raritan Bay complex and New York Harbor) subject to advisories than did other captains, and were more prone to say that management regulations (e.g., fish size, creel limits, seasons) and marketing and advertising by the industry or state were strong influences on the success of their seasons. Comparing captains who thought advisories had some or great effect (60%) versus those reporting "no effect" (40%), there was no difference in the mean percentage of trips targeting high mercury species such as swordfish and shark. Many captains said they would or might post advisories, but 42% of the boat captains said they would not post consumption warnings if the state provided them. The significant portion (at least 15%) of saltwater fishing supported by these businesses suggests that these captains are an important conduit for future risk communication.

Differing perspectives on the use of scientific evidence and the precautionary principle

Different governments and agencies are approaching the use of scientific evidence, weight of evidence, and the precautionary principle in different ways. The European community has used the precautionary principle in situations where the consequences are great, data are unavailable or will be costly (in terms of money and time) to obtain, or data are difficult or impossible to obtain. Other countries, such as the United States, have a risk assessment process that has built-in safety or uncertainty factors which are themselves precautionary. Risk management decisions can be made on the basis of adequate studies, risk assessment, weight-of-evidence approaches, and the application of the precautionary principle. While weight of evidence has been used in the United States for increased research funding and regulator action with respect to some chemicals that are hormonally active, the European community has applied the precautionary principle.

Mobilization of peripheral blood progenitor cells with vinorelbine and granulocyte colony-stimulating factor in multiple myeloma patients is reliable and cost effective

Cyclophosphamide with granulocyte colony stimulating factor (G-CSF) is commonly used to mobilize stem cells in multiple myeloma. Timing of collection is variable and incidence and severity of side effects is substantial. To optimize timing of collection, to reduce side effects and to limit costs of the procedure, we evaluated vinorelbine, a drug shown to have activity in multiple myeloma, in combination with G-CSF as mobilizing regimen. A total of 19 consecutive patients with advanced stage multiple myeloma received one dose of vinorelbine 35 mg/m(2) intravenously on day 1 in an outpatient setting and G-CSF 10 microg/kg/day from day 4 divided in two daily doses. Median CD34+ cell blood counts measured on day 8 of mobilization were 142 x 10(6)/l (range 57-467). One 15-l apheresis on day 8 resulted in sufficient stem cells (median 11.1 x 10(6) CD34+ cells/kg, range 6.2-36.0 prior and median 7.5 x 10(6) CD34+ cells/kg, range 4.0-20.2 post-positive CD34+ cell selection) for transplantation. Hematopoietic recovery was swift with ANC >0.5 x 10(9)/l on day 11 median (range 10-15) and platelets >20 x 10(9)/l on day 12 median (range 10-15) after reinfusion of the stem cells on day 0. No episodes of febrile neutropenia were observed during mobilization. In our institutions cost reduction for the procedure was about 1700 euros compared to the mobilization with cyclophosphamide and G-CSF. Vinorelbine and G-CSF allow precise timing and harvesting of sufficient stem cells, and might be an alternative to cyclophosphamide in the mobilization of stem cells for autologous transplantation in multiple myeloma.

Metals in horseshoe crabs from Delaware Bay

We examined the concentrations of arsenic, cadmium, chromium, lead, manganese, mercury, and selenium in the eggs, leg muscle, and apodeme (carapace musculature) in horseshoe crabs ( Limulus polyphemus) from eight places on the New Jersey and Delaware sides of Delaware Bay to determine whether there were locational differences. Although there were locational differences, the differences were not great. Further, contaminant levels were generally low. The levels of contaminants found in horseshoe crabs were well below those known to cause adverse effects in the crabs themselves or in organisms that consume them or their eggs. Contaminant levels have generally declined in the eggs of horseshoe crabs from 1993 to 2001, suggesting that contaminants are not likely to be a problem for secondary consumers or a cause of their decline.

Raccoon (Procyon lotor) as a bioindicator of mercury contamination at the U.S. Department of Energy's Savannah River Site

Raccoons (n = 95) were collected from the U.S. Department of Energy's Savannah River Site (SRS) and from public hunting areas. Raccoons were collected near a stream drainage system (Steel Creek delta) and a former reactor-cooling reservoir (pond B) that received inputs of mercury-contaminated Savannah River water. Mercury concentrations were determined for hair, liver, kidney, muscle, and spleen tissues. Samples were analyzed using inductively coupled plasma mass spectroscopy (ICP-MS) and cold vapor atomic absorption spectroscopy (CVAAS). Raccoons were also collected from a natural stream floodplain system (Upper Three Runs/Tinker Creek) located upstream of Hg use and storage areas and near coal ash basins. These samples were compared to samples collected from off-site hunting areas near the SRS. Hg concentrations between internal tissues were significantly correlated. Hair did not correlate well with internal tissue and was a weak indicator of raccoon exposure to Hg. Nonetheless, raccoons are potentially good indicators of Hg contamination because tissue concentrations were higher in raccoons from areas with known Hg input than in those from reference areas, and muscle biopsies can be used as biomarkers for contaminant exposure. Muscle Hg concentrations ranged from 0-0.14 ppm from nearby hunting grounds, indicating that people hunting in designated areas near the SRS are at negligible risk for Hg consumption from raccoon meat. Several raccoons collected from the SRS had muscle Hg concentrations at or near the FDA action level for seizing commercial fish due to mercury contamination of 1.0 ppm. Though Hg action levels for wild game have not been proposed, it is clear that some SRS raccoons had Hg levels that warrant concern if these areas would be open to public hunting. Last, 64 raccoons from this study had Hg concentrations that were considered elevated by the U.S. FWS standard (> 1.1 ppm) of ecosystem health for one or two tissues (hair, liver, or kidney), and 17 had high concentrations for most or all tissues.

Exposure of South Carolinians to commercial meats and fish within their meat and fish diet

There has been considerable interest in the public's exposure to a variety of contaminants through the consumption of wild fish and game, yet there is little information on consumption of commercial meats and fish, or the relationship between commercial and self-caught fish. We conducted a dietary survey in 1999 to estimate exposure levels of 464 individuals from people attending the Palmetto Sportsmen's Classic. Mean consumption was similar for beef, chicken/turkey, and wild-caught fish, and much lower for pork and store-bought fish, and still lower for restaurant fish. There were no ethnic differences in the consumption of most commercial fish and meats, although the differences for chicken approached significance. There were significant ethnic differences in consumption of wild-caught fish. Women ate significantly less of all meat types, except store-bought fish. People over 45 ate less beef than younger people, and people younger than 32 ate significantly more chicken than others. There were no significant differences in consumption patterns as a function of income, except for chicken and wild-caught fish; people with higher incomes ate more chicken than others, and people with lower incomes ate more wild-caught fish than others. When all wild-caught and commercial fish and meats are considered, there are significant differences only for ethnicity and gender. Blacks consume significantly more fish than Whites, and men consume significantly more than women.

Metal levels in raccoon tissues: differences on and off the Department of Energy's Savannah River Site in South Carolina

Levels of arsenic, cadmium, chromium, copper, lead, manganese, selenium, and strontium88 were examined in heart, kidney, muscle, spleen and liver of raccoons (Procyon lotor) from four areas on the Department of Energy's Savannah River Site (SRS), including near a former reactor cooling reservoir and a coal ash basin, and from public hunting areas within 15 km of the site. Mercury is mentioned briefly because it is discussed more fully in another paper. We test the hypotheses that there are no differences in metal levels between raccoons on SRS and off the SRS (off-site), and among different locations on the SRS. Although raccoons collected off-site had significantly lower levels of mercury and selenium in both the liver and kidney, there were few consistencies otherwise. There were significantly higher levels of cadmium in liver of on-site compared to off-site raccoons, and significantly higher levels of chromium and strontium88 in kidney of on-site compared to off-site raccoons. Copper and manganese were highest in the liver; cadmium, lead, mercury and selenium were highest in the liver and kidney; chromium was highest in the spleen and muscle; arsenic was highest in the heart, and strontium88 was slightly higher in the kidney than other organs. Where there were significant differences on site, chromium, manganese were highest in raccoon tissues from Steel Creek; arsenic, lead and selenium were highest in the Ash Basin; cadmium was highest at Upper Three Runs; and strontium88 was highest at Upper Three Runs and Steel Creek. The patterns were far from consistent.

The influence of plasma membrane electrostatic properties on the stability of cell ionic composition

An electro-osmotic model is developed to examine the influence of plasma membrane superficial charges on the regulation of cell ionic composition. Assuming membrane osmotic equilibrium, the ion distribution predicted by Gouy-Chapman-Grahame (GCG) theory is introduced into ion transport equations, which include a kinetic model of the Na/K-ATPase based on the stimulation of this ion pump by internal Na(+) ions. The algebro-differential equation system describing dynamics of the cell model has a unique resting state, stable with respect to finite-sized perturbations of various types. Negative charges on the membrane are found to greatly enhance relaxation toward steady state following these perturbations. We show that this heightened stability stems from electrostatic interactions at the inner membrane side that shift resting state coordinates along the sigmoidal activation curve of the sodium pump, thereby increasing the pump sensitivity to internal Na(+) fluctuations. The accuracy of electrostatic potential description with GCG theory is proved using an alternate formalism, based on irreversible thermodynamics, which shows that pressure contribution to ion potential energy is negligible in electrostatic double layers formed at the surfaces of biological membranes. We discuss implications of the results regarding a reliable operation of ionic process coupled to the transmembrane electrochemical gradient of Na(+) ions.

Varicella in a pediatric heart transplant population on nonsteroid maintenance immunosuppression

OBJECTIVE

Varicella-zoster virus has been reported to produce serious, often life-threatening, disease in immunosuppressed patients with a variety of diagnoses. The impact of this virus on the young child after heart transplantation has not been reported.

METHODS

We reviewed the charts of 28 children who were <10 years of age at heart transplantation and had at least 1 year of follow-up. The median follow-up period was 7 years (1.4-13.0 years). All were seronegative for varicella-zoster virus before transplantation. Fourteen (50%) developed varicella at a median time posttransplantation of 3.3 years. The first 7 were admitted for intravenous acyclovir for 3 days followed by oral acyclovir for 7 days. The last 7 were treated as outpatients with oral valacyclovir for 7 days (n = 6) or with oral acyclovir for 10 days (n = 1).

RESULTS

Intravenous and oral regimens both were well tolerated and were without complications. No patient was receiving steroids at the time that they developed their initial episode of varicella. One patient was receiving steroids for therapy of posttransplantation lymphoproliferative disease when she developed recurrent varicella or generalized zoster. No episodes of rejection were attributed to the varicella-zoster virus infection. There were no episodes of localized zoster. All patients experienced seroconversion from undetectable to detectable antibody titers early after varicella, and 12 of the 14 patients continued to have persistent detectable titers in late follow-up. Two of the 14 who received chemotherapy or enhanced immunosuppression after retransplantation transiently lost detectable varicella-zoster virus antibodies but currently have detectable titers.

CONCLUSIONS

Primary varicella-zoster infection was well tolerated in our young pediatric heart transplant recipients, with no serious complications. We now reserve inpatient/intravenous therapy for those who are unable to tolerate oral medications or those who are receiving enhanced immunosuppression.