KLOTHO allele status and the risk of early-onset occult coronary artery disease

We previously identified a functional variant of KLOTHO (termed "KL-VS"), which harbors two amino acid substitutions in complete linkage disequilibrium and is associated with reduced human longevity when in homozygosity. Klotho-deficient mice display extensive arteriosclerosis when fed a normal diet, suggesting a potent genetic predisposition. To determine whether klotho influences atherosclerotic risk in humans, we performed cross-sectional studies to assess the association between the KL-VS allele and occult coronary artery disease (CAD) in two independent samples of apparently healthy siblings of individuals with early-onset (age <60 years) CAD (SIBS-I [N=520] and SIBS-II [N=436]). Occult CAD was defined as the occurrence of a reversible perfusion defect during exercise thallium scintigraphy and/or as an abnormal result of an exercise electrocardiogram (SIBS-I, n=97; SIBS-II, n=56). In SIBS-I, the KL-VS allele conferred a relative odds of 1.90 (95% confidence interval 1.21-2.98) for occult CAD, after adjusting for familial intraclass correlations (P<.005). Logistic regression modeling, incorporating known CAD risk factors, demonstrated that the KL-VS allele is an independent risk factor (P<.019) and that the imposed risk of KL-VS allele status is influenced by modifiable risk factors. Hypertension (P<.022) and increasing high-density lipoprotein cholesterol (HDL-C) levels (P<.022) mask or reduce the risk conferred by the KL-VS allele, respectively, whereas current smoking (P<.004) increases the risk. Remarkably concordant effects of the KL-VS allele and modifying factors on the risk of occult CAD were seen in SIBS-II. These results demonstrate that the KL-VS allele is an independent risk factor for occult CAD in two independent high-risk samples. Modifiable risk factors, including hypertension, smoking status, and HDL-C level, appear to influence the risk imposed by this allele.     

Population estimates of the Endangered Hawaiʻi ʻĀkepa (Loxops coccineus) in different habitats on windward Mauna Loa

Endangered Hawai‘i ?ākepas (Loxops coccineus) are endemic to Hawai‘i island, where they occur in five spatially distinct populations. Data concerning the status and population trends of these unique Hawaiian honeycreepers are crucial for assessing the effectiveness of recovery and management actions. In 2016, we used point‐transect distance sampling to estimate the abundance of Hawai‘i ?ākepas in portions of Hawai‘i Volcanoes National Park (HAVO) and the Ka?ū Forest Reserve (KFR) on Mauna Loa volcano. We then compiled the survey data from four other populations to provide a global population estimate. In our HAVO and KFR study area, we mapped habitat classes to determine the population densities in each habitat. Densities were highest (1.03 birds/ha) in open‐canopy montane ?ōhi?a (Metrosideros polymorpha) woodland. In contrast, densities of the largest ?ākepa population on Mauna Kea volcano were highest in closed‐canopy ?ōhi?a and koa (Acacia koa) forest where the species is dependent on nest cavities in tall (> 15 m), large (> 50‐cm diameter at breast height) trees. We surveyed potential nesting habitat in HAVO and KFR and found only one cavity in the short‐stature montane ?ōhi?a woodland and five cavities in the tall‐stature forest. Differences in densities between the Mauna Kea and Mauna Loa populations suggest that Hawai‘i ?ākepas may exhibit different foraging and nesting behaviors in the two habitats. The estimated overall population density in the HAVO and KFR study area was 0.52 birds/ha, which equates to 3663 (95% CI 1725–6961) birds in their 11,377‐ha population range. We calculated a global population of 16,428 (95% CI 10,065–25,198) birds, which is similar to an estimate of 13,892 (95% CI 10,315–17,469) birds made in 1986. Our results suggest that populations are stable to increasing in the two largest populations, but the three other populations are smaller (range = 77–1443 birds) and trends for those populations are unknown.     

Studies on metacercarial excystment in Himasthla leptosoma (Trematoda: Echinostomatidae) and newly emerged metacercariae

Metacercarial cysts of Himasthla leptosoma were subjected to a solution containing bile salts, trypsin and l cysteine at 41°C. The treatment induced intense metacercarial activity and after 20 min metacercariae burst through the cyst walls and emerged. Electron microscopy demonstrated that organisms burst through a small area of cyst wall which was devoid of a layer of lamellae present elsewhere towards the innermost surface. The appearance of ruptured cyst walls indicated that they had been softened by the excystment medium. Newly emerged metacercariae possessed a reniform collar of 29 cephalic spines and these were sometimes withdrawn into pits, presumably by action of a muscle complex in the head region. Sensory papillae were distributed in a bilaterally symmetrical arrangement around the anterior sucker and none were visible on the surface of the ventral sucker. Tegumental spines were found only from a point some distance behind the head collar to the region of the ventral sucker. The most anterior spines were simple and peg-like and they quickly merged posteriorly into more complex palmate forms.     

The anatomy of Lepetella sierrai (Vetigastropoda,Lepetelloidea): implications for reproduction,feeding, and symbiosis in lepetellid limpets

The Lepetelloidea, a clade of small limpet‐shaped gastropods, can be used as a case study in continental margin and deep‐sea diversification. Lineages in this clade have been found associated with a combination of different substrates, including hydrothermal vents, seeps, wood, whale carcasses, polychaete tubes, chondrichthyan egg cases, seagrass rhizomes, algal holdfasts, crab carapaces, and sponges. Members of one lepetelloidean family, Lepetellidae, live on or inside empty tubes of members of the polychaete genus Hyalinoecia. The detailed morphology of a Mediterranean species, Lepetella sierrai Dantart & Luque 1944, was reconstructed in three dimensions from serial semi‐thin sections and compared with that of eleven other members of Lepetellidae. The hermaphroditic lepetellid limpets possessed a ciliated seminal groove, distinct testis and ovary with a common distal gonoduct, and a seminal receptacle containing mature sperm. A unique alimentary tract, with huge esophageal pouches, no true stomach, an extensive multilobed midgut, and short intestine, was present. Additionally, a bacteriocyte system throughout the entire mantle rim was revealed via light and transmission electron microscopy. This is the first recognized evidence for intracellular microbial symbiosis in lepetelloidean limpets. Semi‐thin sections showed evidence of a parasite, potentially a chitonophilid copepod, penetrating the body wall of the limpet. Hypotheses about reproductive biology, feeding, and symbiosis are presented based on anatomical features and knowledge of the habitat described herein.