Unwrapping broken tails: Biological and environmental correlates of predation pressure in limbless reptiles

Studying species interactions in nature often requires elaborated logistics and intense fieldwork. The difficulties in such task might hinder our ability to answer questions on how biotic interactions change with the environment. Fortunately, a workaround to this problem lies within scientific collections. For some animals, the inspection of preserved specimens can reveal the scars of past antagonistic encounters, such as predation attempts. A common defensive behaviour that leaves scars on animals is autotomy, the loss of a body appendage to escape predation. By knowing the collection site of preserved specimens, it is possible to assess the influence of organismal biology and the surrounding environment in the occurrence of autotomy. We gathered data on tail loss for 8189 preserved specimens of 33 snake and 11 amphisbaenian species to investigate biological and environmental correlates of autotomy in reptiles. We applied generalized linear mixed effect models to evaluate whether body size, sex, life-stage, habitat use, activity pattern, biome, tropicality, temperature and precipitation affect the probability of tail loss in limbless reptiles. We observed autotomy in 23.6% of examined specimens, with 18.7% of amphisbaenian and 33.4% of snake specimens showing tail loss. The probability of tail loss did not differ between snakes and amphisbaenians, but it was higher among large-sized specimens, particularly in adults and females. Chance of tail loss was higher for diurnal and arboreal species, and among specimens collected in warmer regions, but it was unaffected by biome, precipitation, and tropicality. Autotomy in limbless reptiles was affected by size-dependent factors that interplay with ontogeny and sexual dimorphism, although size-independent effects of life-stage and sex also shaped behavioural responses to predators. The increase in probability of tail loss with verticality and diurnality suggests a risk-balance mechanism between species habitat use and activity pattern. Although autotomy is more likely in warmer regions, it seems unrelated to seasonal differences in snakes and amphisbaenians activity. Our findings reveal several processes related to predator-prey interactions involving limbless reptiles, demonstrating the importance of scientific collections to unveil ecological mechanisms at different spatio-temporal scales.

Functional traits and phylogeny explain snake distribution in the world's largest dry forest ecoregion, the Gran Chaco

Macroecological studies describe large‐scale diversity patterns through analyses of species distribution patterns and allows us to elucidate how species differing in ecology, physical requirements, and life histories are distributed in a multidimensional space. These patterns of distributions can be explained by vegetation, and climatic factors, and are determined by historical and current factors. The continuous accumulation of information on the distribution patterns of species is essential to understand the history and evolution of the biota. In this study, we aimed to identify functional and evolutionary drivers that explain the geographic patterns of vertical stratification. We compiled morphological, ecological, and distribution data of 140 species of Chacoan snakes and constructed null models to map their geographic pattern. We used a range of environmental variables to assess which drivers are influencing these biogeographic patterns. Lastly, we used evolutionary data to build the first map of the phylogenetic regions of Chacoan snakes. We found a latitudinal pattern, with a marked verticality in the snake assemblies in the Chaco. Verticality and long‐tailed species richness increased in areas with high stratified habitats and stable temperature. Fossoriality is driven mainly by soil conditions, especially soils with fewer sand particles and less stratified habitat. Phylogenetic regions in the Chaco showed a marked latitudinal pattern, like that observed in the geographic pattern of verticality. The distribution pattern of Chacoan snakes also reflects their evolutionary history, with a marked phylogenetic regionalization.

Evolution of the rostral scale and mimicry in the genus Xenodon Boie, 1826 (Serpentes: Dipsadidae: Xenodontinae)

Snakes are a stimulating life form from an evolutionary perspective. Despite the basic morphological body shape (limbless, with a tubular body), these vertebrates are extremely diverse. The Neotropical region is one of the most diverse regions for snakes in the world, with >650 known species. Within this great diversity, the genus Xenodon includes 12 species with interesting adaptations to terrestrial and semi-fossorial habitats. Members of this genus are mostly diurnal and terrestrial, feed mainly on anurans and exhibit Batesian mimicry of venomous snakes of the genera Bothrops or Micrurus. Here, through phylogenetic analysis and ancestral state estimation, we explore the evolution of the rostral scale and mimicry within the genus Xenodon. Our results suggest that the ancestral lineage of Xenodon had a rounded rostral scale and exhibited Bothrops mimicry. The evolution of the rostral scale in Xenodon might be related to abiotic factors, as an adaptation for open and forested habitats, and mimicry is likely to be related to biotic factors, as a defensive strategy resembling those of venomous snakes.

Predictions of sardine and the Portuguese continental shelf ecosystem dynamics under future fishing, forced-biomass and SST scenarios

We used the Ecopath with Ecosim ecosystem model to assess the future effects of multiple stressors on sardine and the Portuguese continental shelf ecosystem. We assessed individual and combined impacts of changes in sardine fishing pressure, biomass of sardine competitors and predators and sea surface temperature (SST). This study demonstrated that the greatest impact on sardine stock is caused by projected SST rise whose effect is dominant and detrimental to sardine stock regardless of other conditions, including sardine fishing at maximum sustainable yield (FMSY). The largest impact on ecosystem stability, maturity and diversity of flows was observed under the forced-biomass scenarios that simulate changes in biomass of sardine predators and competitors. Moreover, these stressors alongside FMSY are projected to play an important role in the future evolution of the sardine stock. Results presented in this study can assist long-term and strategic management of the Iberian sardine stock.

Diet drinks and dental caries among U.S. adults: cluster analysis

BACKGROUND

In recent years, the consumption of sugar sweetened beverages has been declining, while low calorie sweetener and diet beverage consumption is increasing. Evidence about the effect of diet drinks on dental caries is insufficient, and has not accounted for the complexity of beverage consumption patterns. Therefore, the aim of this study is to examine the association between consuming diet drinks and dental caries among US adults.

METHODS

We analyzed 2011-2014 NHANES dietary data of adults using cluster analysis, with individuals grouped based on their beverage consumption. Clusters were identified based on the R-square statistic and the local peak of the pseudo F statistic. Survey procedure and sample weights were used to account for the complex NHANES sampling design.

RESULTS

Four beverage consumption patterns were identified: "high soda", "high diet drinks", "high coffee/tea" and "high water". The "High soda" cluster was the only one associated with higher DMFT after controlling for confounders (β=1.02, 95% CI=0.42 - 1.63), whereas DT was associated with "high soda" (β=0.45, 95% CI=0.25 - 0.64) and "high coffee/tea" (β=0.24, 95% CI=0.01 - 0.47). On the other hand, the "high diet drinks" cluster was neither associated with DMFT (β=0.69, 95% CI=0.51 - -0.35) nor DT (β=0.07, 95% CI=-0.21 - 0.35).

CONCLUSION

Diet drinks consumption may not be associated with increased risk of dental caries. However, more studies should be conducted in order to confirm this finding.

Dental Erosion: Effect of Diet Drink Consumption on Permanent Dentition

OBJECTIVE

The aim of this study is to examine the effect of diet drinks on dental erosion among a representative sample of US adults.

METHODS

Adult dietary and dental data were analyzed from the 2003-2004 cycle of the National Health and Nutrition Examination Survey. Erosion was measured with a modified tooth wear index and was analyzed as a dichotomous variable. Cluster analysis was performed, and the cluster number was based on having a separate diet drink cluster and the R² values. Survey procedure and sample weights were used.

RESULTS

Most of the population (80%) had some form of dental erosive lesions. When compared with the total sample, people with erosion were more likely to be male (52.5%) and older. People with no erosive lesions were younger (42.3%) and non-Hispanic Black (21.2%). Cluster analysis resulted in 4 distinct clusters: high water, high diet drinks, high coffee/tea, and high soda. The respective percentage of individuals in each cluster who had erosion was 78.9%, 85%, 83.9%, and 76.2%, where the "high diet drinks" cluster showed the highest erosion (P = 0.28). Logistic regression modeling showed that the "high diet drinks" cluster had increased odds of erosion (odds ratio = 1.27; 95% CI = 0.58 to 2.77) when compared with the "high water" cluster, but the relationship was not statistically significant.

CONCLUSION

High diet drinks consumption slightly increased the odds of dental erosion among US adults, although this relationship was not statistically significant. It is thus not yet clear that dentists should recommend diet drinks, as they might be linked to systemic diseases. Further research is needed to explore more about risk factors of erosion.

KNOWLEDGE TRANSFER STATEMENT

The findings of this study are suggestive, though not significantly, that diet drinks may increase risk for dental erosion. While further research is needed, it is not clear that dentists should recommend these drinks as healthy substitutes for sugary drinks.

NEOTROPICAL CARNIVORES: a data set on carnivore distribution in the Neotropics

Mammalian carnivores are considered a key group in maintaining ecological health and can indicate potential ecological integrity in landscapes where they occur. Carnivores also hold high conservation value and their habitat requirements can guide management and conservation plans. The order Carnivora has 84 species from 8 families in the Neotropical region: Canidae; Felidae; Mephitidae; Mustelidae; Otariidae; Phocidae; Procyonidae; and Ursidae. Herein, we include published and unpublished data on native terrestrial Neotropical carnivores (Canidae; Felidae; Mephitidae; Mustelidae; Procyonidae; and Ursidae). NEOTROPICAL CARNIVORES is a publicly available data set that includes 99,605 data entries from 35,511 unique georeferenced coordinates. Detection/non-detection and quantitative data were obtained from 1818 to 2018 by researchers, governmental agencies, non-governmental organizations, and private consultants. Data were collected using several methods including camera trapping, museum collections, roadkill, line transect, and opportunistic records. Literature (peer-reviewed and grey literature) from Portuguese, Spanish and English were incorporated in this compilation. Most of the data set consists of detection data entries (n = 79,343; 79.7%) but also includes non-detection data (n = 20,262; 20.3%). Of those, 43.3% also include count data (n = 43,151). The information available in NEOTROPICAL CARNIVORES will contribute to macroecological, ecological, and conservation questions in multiple spatio-temporal perspectives. As carnivores play key roles in trophic interactions, a better understanding of their distribution and habitat requirements are essential to establish conservation management plans and safeguard the future ecological health of Neotropical ecosystems. Our data paper, combined with other large-scale data sets, has great potential to clarify species distribution and related ecological processes within the Neotropics. There are no copyright restrictions and no restriction for using data from this data paper, as long as the data paper is cited as the source of the information used. We also request that users inform us of how they intend to use the data.

Dataset of occurrences and ecological traits of amphibians from Upper Paraguay River Basin, central South America

There are many gaps in our biodiversity knowledge, especially in highly diverse regions such as the Neotropics. Basic information on species occurrence and traits are scattered throughout different literature sources, which makes it difficult to access data and ultimately delays advances in ecology, evolution, and conservation biology. We provide species occurrence and trait data for amphibian species in the Upper Paraguay River Basin, central South America. The compiled information is made available through two different datasets that hold (i) 17K species occurrence records and (ii) 30 species-level traits for 113 amphibian species. The first dataset includes the species occurrence records and informs specimen id, collection of housing, locality, geographical coordinates, geographic accuracy, collection date, and collector name. The second dataset covers species-level attributes on morphometry, diet, activity, habitat, and breeding strategy. These datasets improve accessibility to spatial and trait data for amphibian species in the Pantanal ecoregion, one of the largest wetlands on Earth.

Multiscale endemism analysis for amphibians of Paraguay

Although there are many studies that analyse and describe the distribution patterns of diverse organisms in South America at different scales, Paraguay has been poorly assessed from a biogeographic point of view. Some of the available contributions on the biogeography of Paraguay are based on different taxonomic groups, such as mammals, birds, reptiles, and plants, describing relationships between species and their habitats by using indices of similarity and cluster analysis. The main objective of this contribution is to identify areas of endemism based on the distribution of the 87 amphibian species known from Paraguay, and to compare the results with the three schemes of ecoregion proposed for the country. Eight areas of endemism were identified at different size of grids/scales, congruent with Dry Chaco, Atlantic Forest, Cerrado, Grasslands of Mesopotamia, Ñeembucú, and the Great American Chaco ecoregions.

NEOTROPICAL XENARTHRANS: a data set of occurrence of xenarthran species in the Neotropics

Xenarthrans-anteaters, sloths, and armadillos-have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, 10 anteaters, and 6 sloths. Our data set includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the southern United States, Mexico, and Caribbean countries at the northern portion of the Neotropics, to the austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n = 5,941), and Cyclopes sp. have the fewest (n = 240). The armadillo species with the most data is Dasypus novemcinctus (n = 11,588), and the fewest data are recorded for Calyptophractus retusus (n = 33). With regard to sloth species, Bradypus variegatus has the most records (n = 962), and Bradypus pygmaeus has the fewest (n = 12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other data sets of Neotropical Series that will become available very soon (i.e., Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans data set. Please cite this data paper when using its data in publications. We also request that researchers and teachers inform us of how they are using these data.

Revalidation of Apostolepis barrioi (Serpentes: Dipsadidae)

With 32 species, Apostolepis is the most diverse genus in the tribe Elapomorphini. The description of Apostolepis barrioi is based on one specimen and the taxon later was synonymized with A. dimidiata. Based on a examination of new specimens, the taxon is resurrected to full species rank. Apostolepis barrioi differs from all congeners by having an immaculate white venter, narrow dorsolateral stripes not in contact with the ventrals, and a terminal black shield. With the addition of A. barrioi, the number of species of the genus increases to 33; however, more systematic research on the status of the species in the group is required, especially for those species that were described on the basis of only on few specimens.

Heterocyclic boronic acids display sialic acid selective binding in a hypoxic tumor relevant acidic environment

A group of heterocyclic boronic acids demonstrating unusually high affinity and selectivity for sialic acids are described, with strong interactions under the weakly acidic pH conditions associated with a hypoxic tumoral microenvironment.

Boronic acids are well known for their ability to reversibly interact with the diol groups found in sugars and glycoproteins. However, they are generally indiscriminate in their binding. Herein we describe the discovery of a group of heterocyclic boronic acids demonstrating unusually high affinity and selectivity for sialic acids (SAs or N-acetylneuraminic acid), which are sugar residues that are intimately linked with tumor growth and cancer progression. Remarkably, these interactions strengthen under the weakly acidic pH conditions associated with a hypoxic tumoral microenvironment. In vitro competitive binding assays uncovered a significantly higher ability of 5-boronopicolinic acid, one of the derivatives identified in this work as a strong SA-binder, to interact with cell surface SA in comparison to a gold-standard structure, 3-propionamidophenylboronic acid, which has proven to be an efficient SA-binder in numerous reports. This structure also proved to be suitable for further chemical conjugation with a well-preserved SA-binding capability. These findings suggest an attractive alternative to other ongoing boronic acid based chemistry techniques aiming to achieve tumor-specific chemotherapies and diagnoses.

Closed-loop optical neural stimulation based on a 32-channel low-noise recording system with online spike sorting

OBJECTIVE

Closed-loop operation of neuro-electronic systems is desirable for both scientific and clinical (neuroprosthesis) applications. Integrating optical stimulation with recording capability further enhances the selectivity of neural stimulation. We have developed a system enabling the local delivery of optical stimuli and the simultaneous electrical measuring of the neural activities in a closed-loop approach.

APPROACH

The signal analysis is performed online through the implementation of a template matching algorithm. The system performance is demonstrated with the recorded data and in awake rats.

MAIN RESULTS

Specifically, the neural activities are simultaneously recorded, detected, classified online (through spike sorting) from 32 channels, and used to trigger a light emitting diode light source using generated TTL signals.

SIGNIFICANCE

A total processing time of 8 ms is achieved, suitable for optogenetic studies of brain mechanisms online.

Selective intracellular delivery of proteasome inhibitors through pH-sensitive polymeric micelles directed to efficient antitumor therapy

The ubiquitin-proteasome system is central in the regulation of cellular proteins controlling cell cycle progression and apoptosis, drawing much interest for developing effective targeted cancer therapies. Herein, we developed a novel pH-responsive polymeric-micelle-based carrier system to effectively deliver the proteasome inhibitor MG132 into cancer cells. MG132 is covalently bound to the block copolymer composed of polyethylene glycol (PEG) and polyaspartate through an acid-labile hydrazone bond. This bond is stable at physiological condition, but hydrolytically degradable in acidic compartments in the cell, such as late-endosomes and lysosomes, and thus, it was used for controlled release of MG132 after EPR-mediated preferential accumulation of the micelles into the tumor. MG132-loaded micelles have monodispersed size distribution with an average diameter of 45nm, and critical micelle concentration is well below 10(-7)M. In vitro studies against several cancer cell lines confirmed that MG132-loaded micelles retained the cytotoxic effect, and this activity was indeed due to the inhibition of proteasome by released MG132 from the micelles. Real-time in vitro confocal-microscopy experiments clearly indicated that MG132-conjugated micelles disintegrated only inside the target cells. By intravital confocal micro-videography, we also confirmed the prolonged circulation of MG132 loaded micelles in the bloodstream, which lead to tumor specific accumulation of micelles, as confirmed by in vivo imaging 24h after injection. These micelles showed significantly lower in vivo toxicity than free MG132, while achieving remarkable antitumor effect against a subcutaneous HeLa-luc tumor model. Our findings create a paradigm for future development of polymeric-micelle-based carrier system for other peptide aldehyde type proteasome inhibitors to make them effective cohort of the existing cancer therapeutic regiments.

Opioid use for noncancer pain and risk of myocardial infarction amongst adults

BACKGROUNDS

With increasing use of opioids for chronic noncancer pain comes concern about safety of this class of drugs. Opioid-induced hypogonadism, which could increase the risk for myocardial infarction (MI), has recently come to the attention of clinicians. To evaluate this concern we examined the association between opioid use for noncancer pain and risk of MI amongst adults.

METHODS

We conducted a nested case-control study using the UK General Practice Research Database. Amongst 1.7 million opioid users during 1990-2008, we identified 11 693 incident MI cases aged 18-80 years, and randomly selected up to four controls matched by age, gender, index date (date of onset symptoms or diagnosis of first-ever MI) and general practice via risk-set sampling. Cases and controls were required to have no cancer and no major risk factors for MI before the index date. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated from conditional logistic regression.

RESULTS

Compared with nonuse, current use of opioids was associated with a 1.28-fold (95% CI 1.19-1.37) risk of MI. Cumulative use of opioids with 11-50 (OR = 1.38, 95% CI: 1.28-1.49) or > 50 (OR = 1.25, 95% CI: 1.11-1.40) prescriptions, was also marginally associated with increased risk of MI. The risk was particularly increased in users of morphine (OR = 1.71, 95% CI: 1.09-2.68), meperidine (OR = 2.15, 95% CI: 1.24-3.74) and polytherapy (OR = 1.46, 95% CI: 1.22-1.76).

CONCLUSIONS

Current use of any opioids and cumulative use of 11 or more prescriptions are associated with a small increased risk for MI compared to nonuse and the risk was greater in morphine, meperidine and polytherapy users. Residual confounding, particularly confounding by indication, should be considered in interpreting our results.

Polymeric micelles incorporating (1,2-diaminocyclohexane)platinum (II) suppress the growth of orthotopic scirrhous gastric tumors and their lymph node metastasis

Nano-scaled drug carriers have great potential for the treatment of solid tumors. Nevertheless, hypovascularity and fibrosis in some types of solid tumors have been demonstrated to reduce the penetration and accumulation of nano-scaled drug carriers. Diffuse-type scirrhous gastric cancers present such characteristics as well as frequent metastasis to the lymph nodes; therefore, it remains a great challenge to eradicate scirrhous gastric cancers based on the drug targeting using nanocarriers. Herein, we demonstrated that polymeric micelles with 30-nm diameter incorporating (1,2-diaminocyclohexane)platinum(II) (DACHPt), the parent complex of the anticancer drug oxaliplatin, efficiently penetrated and accumulated in an orthotopic scirrhous gastric cancer model, leading to the inhibition of the tumor growth. Moreover, the elevated localization of systemically injected DACHPt-loaded micelles in metastastic lymph nodes reduced the metastatic tumor growth. These results suggest DACHPt-loaded micelles as a promising nanocarrier for the treatment of scirrhous gastric cancers and their lymphatic metastases.

Squamata, Serpentes, Micrurus silviae Di-Bernardo, Borges-Martins and Silva, 2007: presence confirmation in Paraguay

Micrurus silviae is a coralsnake with a triadal pattern, and is one of the eight species found in southern South America. In Paraguay there are six taxa recorded: M. altirostris, M. baliocoryphus, M. frontalis, M. pyrrhocryptus, M. corallinus, and M. lemniscatus carvalhoi. Here we present a record of M. silviae, an additional and seventh species for the country. Previously M. silviae was known only from Rio Grande do Sul state, in southern Brazil. The specimen was found in South American Mesopotamian Grasslands ecoregion, with natural grassland in the Department of Itapúa.

Accumulation of sub-100 nm polymeric micelles in poorly permeable tumours depends on size

A major goal in cancer research is to develop carriers that can deliver drugs effectively and without side effects. Liposomal and particulate carriers with diameters of ∼100 nm have been widely used to improve the distribution and tumour accumulation of cancer drugs, but so far they have only been effective for treating highly permeable tumours. Here, we compare the accumulation and effectiveness of different sizes of long-circulating, drug-loaded polymeric micelles (with diameters of 30, 50, 70 and 100 nm) in both highly and poorly permeable tumours. All the polymer micelles penetrated highly permeable tumours in mice, but only the 30 nm micelles could penetrate poorly permeable pancreatic tumours to achieve an antitumour effect. We also showed that the penetration and efficacy of the larger micelles could be enhanced by using a transforming growth factor-β inhibitor to increase the permeability of the tumours.

Assessing anthropogenic pressures on estuarine fish nurseries along the Portuguese coast: a multi-metric index and conceptual approach

Estuaries are among the most productive ecosystems and simultaneously among the most threatened by conflicting human activities which damage their ecological functions, namely their nursery role for many fish species. A thorough assessment of the anthropogenic pressures in Portuguese estuarine systems (Douro, Ria de Aveiro, Mondego, Tejo, Sado, Mira, Ria Formosa and Guadiana) was made applying an aggregating multi-metric index, which quantitatively evaluates influences from key components: dams, population and industry, port activities and resource exploitation. Estuaries were ranked from most (Tejo) to least pressured (Mira), and the most influential types of pressure identified. In most estuaries overall pressure was generated by a dominant group of pressure components, with several systems being afflicted by similar problematic sources. An evaluation of the influence of anthropogenic pressures on the most important sparidae, soleidae, pleuronectidae, moronidae and clupeidae species that use these estuaries as nurseries was also performed. To consolidate information and promote management an ecological conceptual model was built to identify potential problems for the nursery function played by these estuaries, identifying pressure agents, ecological impacts and endpoints for the anthropogenic sources quantified in the assessment. This will be important baseline information to safeguard these vital areas, articulating information and forecasting the potential efficacy of future management options.

The 6-min walk distance: change over time and value as a predictor of survival in severe COPD

The 6-min walk distance (6MWD) is used to evaluate the functional capacity of patients with chronic obstructive pulmonary disease (COPD). The change in 6MWD over time and its correlation with changes in spirometry and survival are unclear. Patients (n=198) with severe COPD and 41 age-matched controls were followed for 2 yrs, and anthropometrics, spirometry, 6MWD and comorbidities were measured. The 6MWD decreased in the COPD group from 238 +/- 107 m to 218 +/- 112 m (-26 +/- 37 m x yr(-1)), and increased in the control group from 532 +/- 82 m to 549 +/- 86 m (12 +/- 25 m x yr(-1)). In both groups, there was a poor correlation with changes in forced expiratory volume in one second (FEV1). Nonsurvivors in the COPD group (42%) had a more pronounced change in the 6MWD (-40 versus -22 m x yr(-1)) but a similar change in FEV1 (118 versus 102 mL x yr(-1)). The 6MWD independently predicted survival, after accounting for age, body mass index, FEV1 and comorbidities. In severe chronic obstructive pulmonary disease, the 6-min walk distance predicts mortality better than other traditional markers of disease severity. Its measurement is useful in the comprehensive evaluation of patients with severe disease.

Is a general women's health promotion program as effective as an HIV-intensive prevention program in reducing HIV risk among Hispanic women?

OBJECTIVE

This study aimed to assess whether participants in an HIV-intensive prevention program and participants in a general women's health promotion program reported greater HIV risk-reduction than participants in a wait-list control group immediately following program participation and at three-month follow-up.

METHODS

The authors studied 162 Hispanic women ages 18 to 35 years, most of them immigrants. Three-fourths of the sample (74%) reported earning less than $800 a month, 29% did not have a high school degree, and 90% had children. Data were gathered through surveys at baseline, at intervention completion, and at three-month follow-up. Information was collected on sociodemographics, HIV risk factors, and risk behaviors. Crude and adjusted (for demographics and dose) logistic regression analyses were used to assess program effects on participants' risk reduction.

RESULTS

Crude logistic regression analyses reveal that both programs resulted in increased condom use at post-test and follow-up. Only participants in the HIV-intensive prevention program reported increased safer sex negotiation at post-test and follow-up, however, and only participants in the women's health promotion program reported increased HIV testing at post-test.

CONCLUSION

Both interventions increased condom use. The HIV-intensive prevention program appeared to be more effective in promoting safer sex negotiation, and the women's health promotion program appeared more effective in promoting HIV testing. The findings suggest that both approaches may be viable ways to package HIV prevention for short-term behavior change in this population.

Bioequivalence of a propylene glycol-based liquid dapsone preparation and dapsone tablets

The bioequivalence of a proprietary liquid dapsone preparation and commercially available dapsone tablets was studied. Twelve adult volunteers received dapsone doses with 8 oz of water one to two hours after their usual breakfast. Each subject received an initial 100-mg dose of a propylene glycol-based liquid preparation of dapsone and, two weeks later, a 100-mg dapsone tablet (both from Jacobus Pharmaceutical Company, Princeton, NJ). Blood samples were collected before and at intervals up to 96 hours after the administration of each dose. Serum dapsone concentrations were determined by high-performance liquid chromatography, and pharmacokinetic values were calculated by model-independent analysis. The area under the concentration-versus-time curve and the maximum serum concentration for the two formulations met the criteria for bioequivalence. Time to maximum serum concentration tended to be lower for the liquid, but not significantly. The liquid and tablet formulations of dapsone studied were found to be bioequivalent and may be used interchangeably.

Risk of basal cell and squamous cell carcinoma in persons with prior cutaneous melanoma

BACKGROUND

Melanoma has been associated with an overall increase in actinic tumors, including actinic keratoses, as well as with noncutaneous malignancies.

OBJECTIVE

Determine the risk of developing basal cell and squamous cell skin cancer in patients with prior cutaneous melanoma (actinic keratoses not encountered).

METHODS

This retrospective study included 1396 white patients with prior cutaneous melanoma followed at the Roswell Park Cancer Institute in the period 1977-1978. The control group was the white population of the Detroit area in the same period (1977-1978).

RESULTS

A total of 25 patients (18 males, 7 females) developed 35 basal cell and/or squamous cell carcinomas: 18 developed basal cell carcinomas, 2 squamous cell carcinomas, and 5 both. The calculated odds ratio was 3.49 (males 3.67, females 2.86, 95% confidence interval 1.52-8.00). No correlations were found with age, type, anatomic site, and length of follow-up of cutaneous melanoma.

CONCLUSION

A history of cutaneous melanoma significantly increases the risk of basal cell and squamous cell skin cancer.

Level of in utero cocaine exposure and neonatal ultrasound findings

OBJECTIVE

To assess whether there is an association between the level of in utero cocaine exposure and findings on neonatal cranial ultrasound, controlling for potentially confounding variables.

STUDY DESIGN

In a prospective longitudinal study, three cocaine exposure groups were defined by maternal report and infant meconium assay: unexposed, heavier cocaine exposure (>75th percentile self-reported days of use or of meconium benzoylecogonine concentration) or lighter cocaine exposure (all others). Neonatal ultrasounds from 241 well, term infants were read by a single radiologist who was masked to the exposure group.

RESULTS

Infants with lighter cocaine exposure did not differ from the unexposed infants on any ultrasound findings. After controlling for infant gender, gestational age, and birth weight z scores and for maternal parity, blood pressure in labor, ethnicity, and use of cigarettes, alcohol, and marijuana during pregnancy, the more heavily cocaine-exposed infants were more likely than the unexposed infants to show subependymal hemorrhage in the caudothalamic groove (covariate adjusted odds ratio: 3.88; 95% confidence interval: 1.45, 10.35).

CONCLUSIONS

This is the first study to demonstrate that ultrasound findings suggestive of vascular injury to the neonatal central nervous system are related to the level of prenatal cocaine exposure. Inconsistency in previous research in identifying an association between prenatal cocaine exposure and neonatal cranial ultrasound findings may reflect failure to consider dose effects.

Blood pressure in children exposed prenatally to cocaine

Prenatal exposure to cocaine may alter autonomic nervous system function resulting in hypertension. Blood pressure was measured oscillometrically in a convenience sample of cocaine-exposed (n = 32) and nonexposed (n = 23) children, aged 8 to 26 months, by examiners unaware of exposure status. The exposed and nonexposed groups did not differ in systolic pressure (mean +/- SD 102.3 +/- 9.9 mmHg vs 119.1 +/- 19.4). Prenatal exposure to cocaine does not appear to be associated with elevated blood pressure in young children.

Elevated plasma norepinephrine after in utero exposure to cocaine and marijuana

OBJECTIVE

To compare plasma catecholamine concentrations between cocaine-exposed and unexposed term newborns and to determine the relationship between plasma catecholamines and newborn behavior.

METHODS

Forty-six newborn infants participating in a prospective study of the neonatal and long-term effects of prenatal cocaine exposure were studied. Based on maternal self-report, maternal urine screening, and infant meconium analysis, 24 infants were classified as cocaine-exposed and 22 as unexposed. Between 24 and 72 hours postpartum, plasma samples for norepinephrine (NE), epinephrine, dopamine, and dihydroxyphenylalanine analysis were obtained. The Neonatal Behavioral Assessment Scale was administered at 1 to 3 days of age and at 2 weeks of age by examiners masked to the drug exposure status of the newborns.

RESULTS

The cocaine-exposed newborns had increased plasma NE concentrations when compared to the unexposed infants (geometric mean, 923 pg/mL vs 667 pg/mL). There were no significant differences in plasma epinephrine, dopamine, or dihydroxyphenylalanine concentrations. Analysis for the effect of potential confounding variables revealed that maternal marijuana use was also associated with increased plasma NE, although birth weight, gender, and maternal use of alcohol or cigarettes were not. Geometric mean plasma NE was 1164 pg/mL in those infants with in utero exposure to both cocaine and marijuana compared to 812 pg/mL in those exposed to only cocaine and 667 pg/mL in those exposed to neither. Among the cocaine-exposed infants, plasma NE concentration correlated with an increased score for the depressed cluster (r = .53) and a decreased score for the orientation cluster (r = -.43) of the Neonatal Behavioral Assessment Scale administered at 1 to 3 days of age. Adjusting for marijuana exposure had no effect on these relationships between plasma NE and the depressed and orientation clusters.

CONCLUSION

Plasma NE is increased in newborns exposed to cocaine and marijuana. Increased plasma NE is associated with selected neurobehavioral disturbances among cocaine exposed infants at 1 to 3 days of life but not at 2 weeks.

Late dose-response effects of prenatal cocaine exposure on newborn neurobehavioral performance

OBJECTIVE

To determine in a representative sample of full-term urban newborns of English-speaking mothers whether an immediate or late dose-response effect could be demonstrated between prenatal cocaine exposure and newborn neurobehavioral performance, controlling for confounding factors.

METHODS

The Neonatal Behavioral Assessment Scale (NBAS) was administered by masked examiners to a total sample of 251 clinically healthy, full-term infants at 2 days and/or 17 days. Three in utero cocaine exposure groups were defined: heavily exposed (n = 44, > 75th percentile self-reported days of use during pregnancy and/or > 75th percentile of meconium benzoylecognine concentration); lightly exposed (n = 79, less than both 75th percentiles); and unexposed (n = 101, no positive biological or self-report marker). At the 3-week examination there were 38 heavily exposed, 73 lightly exposed, and 94 unexposed infants. Controlling for infant birth weight, gestational age, infant age at the time of examination, mothers' age, perinatal risk, obstetric medication, and alcohol, marijuana, and cigarette use, a regression analysis evaluated the effects of levels of cocaine exposure on NBAS performance.

RESULTS

No neurobehavioral effects of exposure on the newborn NBAS cluster scores or on the qualifier scores were found when confounders were controlled for at 2 to 3 days of age. At 3 weeks, after controlling for covariates, a significant dose effect was observed, with heavily exposed infants showing poorer state regulation and greater excitability.

CONCLUSIONS

These findings demonstrate specific dose-related effects of cocaine on 3-week neurobehavioral performance, particularly for the regulation of arousal, which was not observed in the first few days of life.

Company characteristics and workplace medical testing

OBJECTIVES

This study measures the relative impact of company economic characteristics and workplace hazards on the prevalence of several types of medical testing. It uses the results to assess likely public health impacts of testing.

METHODS

We used data on potential exposure to workplace hazards, medical testing, unionization, firm size, and turnover from the National Occupational Hazards Survey and the National Occupational Exposure Survey. Other sources provided industry-specific data on wages and turnover. Logistic regression analysis estimated the relationship of economic variables and workplace health risks to the prevalence of medical testing.

RESULTS

Economic variables were related to the prevalence of testing. However, consistent positive relationships were not found between health hazards and testing.

CONCLUSIONS

Employers' testing decisions may not be beneficial to the health of workers and may shift the costs of illness to workers or other employers. Safer firms may provide too much medical testing, and firms that are less safe may provide too little.

Early neurodevelopmental growth in children with vertically transmitted human immunodeficiency virus infection

OBJECTIVE

To examine mental and motor development in children with vertically transmitted human immunodeficiency virus (HIV) infection in the first 30 months of life.

DESIGN

Prospective longitudinal study comparing two groups: children with HIV infection and HIV-exposed but uninfected children.

SETTING

Pediatric Immunodeficiency Clinic at Boston (Mass) City Hospital, Boston University Medical Center.

STUDY PARTICIPANTS

Twenty-four children with vertically transmitted HIV infection and 27 children who were born to HIV-infected mothers and became HIV negative served as controls. Socioeconomic status, gestational age, and prenatal drug exposure were comparable in the two groups.

MEASUREMENTS/RESULTS

Using the Bayley Scales of Infant Development, all children were assessed at least once between 4 and 16 months and again between 17 and 30 months of age. Individual mean mental and motor scores were calculated for the early and later age span. Motor development in the infected group was delayed in comparison to the seroreverter group in both age spans and remained stable in both groups over time. Mental development was comparable in the two groups at 4 to 17 months, but HIV infection was associated with delay in mental development at 17 to 30 months of age.

CONCLUSION

Early and persistent delay in motor development and deceleration in mental development in late infancy distinguishes many children who are HIV infected from exposed but uninfected children, but there is significant variability in early neurodevelopmental outcome among children with HIV infection.

Relation between meconium concentration of the cocaine metabolite benzoylecgonine and fetal growth

Among 95 term infants with benzoylecgonine, the cocaine metabolite, detectable in their meconium, there was an inverse relation between the concentration of benzoylecgonine and birth weight, length, and head circumference. Multiple regression analysis confirmed these relations after controlling for gestational age and maternal use of marijuana, cigarettes, and alcohol. These data suggest a dose-response relation between the magnitude of prenatal cocaine exposure and impaired fetal growth.