Regional peak plantar pressures are highly sensitive to region boundary definitions

Traditional pedobarographic analyses subsample pressure data over a number of discrete anatomical regions of interest (ROIs). To our knowledge, the sensitivity of these data to ROI boundary definitions has not been previously addressed. Eight subjects each performed 20 trials of self-paced walking; commercial software was used to define 10 ROIs for each of the 160 total peak pressure images, and regional peak pressures (RPPs) were extracted for each image (total: 1600 values). We then asked three specific questions regarding RPP sensitivity to ROI boundary definition: (1) Is the ROI centroid representative of the RPP location? (2) How frequently do RPPs lie on the ROI boundary? and (3) By how much do RPP values change if the ROI boundary is changed by one pixel (resolution: 5.08×7.62 mm)? We found that the RPP locations differed from the ROI centroid in 80% of the cases and that the RPPs lay on the ROI boundary with a probability of 65%. We also found that a single-pixel change in the ROI boundary caused a mean RPP change of 10.8%. The most sensitive region was the midfoot for which a single-pixel ROI change yielded a median 29.4% change in RPP. These results indicate that RPP data are biased by regionalization schemes, which delineate pressure fields based on anatomy rather than on the field's geometric properties, and ultimately that regionalization may constitute a poor method of quantifying complex pressure fields. RPP sensitivity should be considered when making statistical inferences regarding foot function.     

Neural Mechanisms Associated With Food Motivation in Obese and Healthy Weight Adults

One out of three adults in the United States is clinically obese. Excess food intake is associated with food motivation, which has been found to be higher in obese compared to healthy weight (HW) individuals. Little is known, however, regarding the neural mechanisms associated with food motivation in obese compared to HW adults. The current study used functional magnetic resonance imaging (fMRI) to examine changes in the hemodynamic response in obese and HW adults while they viewed food and nonfood images in premeal and postmeal states. During the premeal condition, obese participants showed increased activation, compared to HW participants, in anterior cingulate cortex (ACC) and medial prefrontal cortex (MPFC). Moreover, in the obese group, self‐report measures of disinhibition were negatively correlated with premeal ACC activations and self‐report measures of hunger were positively correlated with premeal MPFC activations. During the postmeal condition, obese participants also showed greater activation than HW participants in the MPFC. These results indicate that brain function associated with food motivation differs in obese and HW adults and may have implications for understanding brain mechanisms contributing to overeating and obesity, and variability in response to diet interventions.     

Immunogenicity and Serological Cross-Reactivity of Saliva Proteins among Different Tsetse Species

Tsetse are vectors of pathogenic trypanosomes, agents of human and animal trypanosomiasis in Africa. Components of tsetse saliva (sialome) are introduced into the mammalian host bite site during the blood feeding process and are important for tsetse’s ability to feed efficiently, but can also influence disease transmission and serve as biomarkers for host exposure. We compared the sialome components from four tsetse species in two subgenera: subgenus Morsitans: Glossina morsitans morsitans (Gmm) and Glossina pallidipes (Gpd), and subgenus Palpalis: Glossina palpalis gambiensis (Gpg) and Glossina fuscipes fuscipes (Gff), and evaluated their immunogenicity and serological cross reactivity by an immunoblot approach utilizing antibodies from experimental mice challenged with uninfected flies. The protein and immune profiles of sialome components varied with fly species in the same subgenus displaying greater similarity and cross reactivity. Sera obtained from cattle from disease endemic areas of Africa displayed an immunogenicity profile reflective of tsetse species distribution. We analyzed the sialome fractions of Gmm by LC-MS/MS, and identified TAg5, Tsal1/Tsal2, and Sgp3 as major immunogenic proteins, and the 5''-nucleotidase family as well as four members of the Adenosine Deaminase Growth Factor (ADGF) family as the major non-immunogenic proteins. Within the ADGF family, we identified four closely related proteins (TSGF-1, TSGF-2, ADGF-3 and ADGF-4), all of which are expressed in tsetse salivary glands. We describe the tsetse species-specific expression profiles and genomic localization of these proteins. Using a passive-immunity approach, we evaluated the effects of rec-TSGF (TSGF-1 and TSGF-2) polyclonal antibodies on tsetse fitness parameters. Limited exposure of tsetse to mice with circulating anti-TSGF antibodies resulted in a slight detriment to their blood feeding ability as reflected by compromised digestion, lower weight gain and less total lipid reserves although these results were not statistically significant. Long-term exposure studies of tsetse flies to antibodies corresponding to the ADGF family of proteins are warranted to evaluate the role of this conserved family in fly biology.     

Inflammatory cytokine profile and circulating cortisol levels in malnourished children with necrotizing ulcerative gingivitis

Necrotizing ulcerative gingivitis (NUG), a periodontal disease traditionally associated with stressful lifestyles in young adults in developed countries, is very prevalent in socioeconomically deprived Nigerian children. Random incident cases (153) of NUG, along with their neighborhood village counterparts of comparable age and without NUG, as control, were recruited for this study. Anthropometric evaluation revealed widespread malnutrition and poor health in both groups of children, with more severe stunting in NUG cases. The poor nutritional status of the village children, with and without NUG, was also confirmed by markedly reduced levels of circulating micronutrients. Compared with the neighborhood children, NUG victims showed significant (p < 0.05 or < 0.001) increases in serum levels of interleukin (IL)-8 (+ 233%), IL-18 (+ 30%), IL-6 (+ 190%), IL-1beta (+ 341%), IL-10 (+ 186%), with a small decrease in interferon (IFN)-gamma (-19%) and nonsignificant increases in soluble tumor necrosis factor (TNF) receptors (sTNFR-p55, p75). Associated with NUG was a significant, 38% (p < 0.05) increase in plasma cortisol above the already high levels observed in the neighborhood village children, as well as some micronutrient deficiencies. The findings suggest that NUG is associated with dysregulated cytokine production, with a complex interplay of elevated levels of pro- and anti-inflammatory mediators. Such changes may serve as the common link between the seemingly unrelated risk conditions (e.g. stressful life styles, smoking, microbial infections, diabetes, malnutrition, alcoholism) traditionally implicated in the genesis of NUG, and all known to promote an increase in the blood level of cortisol, as well as a Th(1) to Th(2) cytokine shift.     

Haemoproteids of the avian family Dicruridae (the drongos)

Dicrurids are a widespread avian family in Africa and Asia. Earlier surveys of this family in these areas have reported the presence of hematozoa and 1 species of Haemoproteus, i.e., Haemoproteus dicruri (De Mello, 1935). One species of drongo occurs in Madagascar and has not been examined previously. Blood smears collected from wild-caught crested drongos, Dicrurus forficatus, in Madagascar were examined using a compound microscope for the presence of hematozoa. A new species, Haemoproteus khani, is described in this study. This new species has circumnuclear gametocytes, in contrast to the halteridial H. dicruri. In addition, H. dicruri is reported for the first time from the crested drongo and is redescribed. This is the first report of hematozoa in drongos of Madagascar.     

A new species of Plasmodium from Malagasy vangas

During a recent examination of blood smears from Malagasy birds, a species of avian Plasmodium unlike those currently known was observed. All infected birds were members of the Vangidae, which is endemic to Madagascar and the Comoro Islands. Plasmodium parvulum n. sp. is described, and classified as a member of the subgenus Haemamoeba because of gametocyte and schizont shape, displacement of the host cell nucleus, as well as distortion of the host cell. Round, rosettelike schizonts with 6-8 merozoites, clumped refractile granules, and little cytoplasm were observed. Both schizonts and mature, round gametocytes rotated and displaced the erythrocyte nucleus. A brief comparison to P. relictum is included.     

The use of low-frequency vocalizations in African elephant(Loxodonta africana) reproductive strategies

Fertility-advertisement calls in females are predicted to occur in nonmonogamous species where males and females are widely separated in space. In African elephants, low-frequency vocalizations have thus been suggested as a reproductive strategy used by fertile females to attract mates. This study examined the use of low-frequency vocalizations with respect to different phases of the estrous cycle in African elephants by simultaneously monitoring vocalizations, behavior, and hormonal profiles. Subjects were one male and six female African elephants housed at Disney's Animal Kingdom. No acoustically distinct vocalizations were restricted to the ovulatory follicular phase. However, overall rate of low-frequency vocalization as well as the rate of one acoustically distinct vocalization changed over the estrous cycle, with highest rates of calling related to the first period of follicular growth, or anovulatory follicular phase. Elevated rates of vocalization thus were not restricted to behavioral estrus and occurred much earlier in the estrous cycle than in most species that produce fertility-advertisement calls. Both herd composition and elephant identity also affected rates of vocalization. Vocalizations therefore may not be reliable signals of actual fertility. However, the increase in vocalizations in advance of estrus may attract males to the herd prior to ovulation, facilitating both male-male competition and female choice. Once present in the herd, males may then switch strategies to use more reliable chemical and visual cues to detect ovulating females.     

Tissue plasminogen activator is released into cultured medium by cultured human uveal melanocytes

Melanoma cells produce tissue plasminogen activator (t-PA) that plays an important role in tumor invasion and metastasis. The production of t-PA by normal human uveal melanocytes has not been reported previously. In order to explore this possibility, we studied the production of t-PA by cultured human uveal melanocytes and compared that with the production by cultured human uveal melanoma cells and epidermal melanocytes. Human adult uveal melanocytes were isolated and cultured from donor eyes. The cells were cultured in serum-free medium for 48 h and the conditioned medium then collected for the plasminogen activator (PA) activity assay. Free PA activity was tested in an amidolytic assay using a t-PA standard curve. PA type was identified by fibrinography and antihuman t-PA and urokinase plasminogen activator (u-PA) blocking antibodies. Free PA activity was found in the conditioned medium of normal melanocytes and melanoma cells. The predominant PA activity was t-PA. Normal uveal melanocytes produced more t-PA (3.23 +/- 0.73 IU/105 cells/24 h) than that of epidermal melanocytes (1.25 IU/105 cells/24 h) but much less than uveal melanoma cells (11.0 +/- 3.39 IU/105 cells/24 h). Western blot analysis revealed that most t-PA in conditioned media were one-chain t-PA with molecular weight of 69 kDa. Our study indicates that uveal melanocytes may contribute to the free t-PA activity previously found in aqueous humor and choroidal eye cup superfusions. Therefore, this function of uveal melanocytes may play a role in intraocular matrix remodeling, fibrinolysis and aqueous humor outflow.