Endothelial dysfunction marker YKL-40 is elevated in male patients with idiopathic infertility.

Metabolic syndrome represents a collection of cardiovascular risk factors, including overweight, hypertension, dyslipidemia and impaired glucose metabolism, with insulin resistance. In recent years, the potential relationship between metabolic syndrome and male factor infertility has been studied. As endothelial dysfunction is the hallmark of metabolic syndrome, the aim of this work was to assess serum levels of YKL-40 as a marker of endothelial dysfunction in male patients with idiopathic infertility. The study revealed that YKL-40 levels were elevated in patients than controls denoting that endothelial dysfunction might play a role in the pathogenesis of idiopathic infertility and that YKL-40 as a marker of endothelial dysfunction could be a useful marker of idiopathic infertility.

Serum relaxin-3 hormone relationship to male delayed puberty.

Puberty is the transitional period between childhood and adulthood, a process encompassing morphological, physiological and behavioural development to attain full reproductive capability. This study aimed to assess serum relaxin-3 hormone relationship with male delayed puberty. Sixty males were investigated as two equal groups: males with delayed puberty and healthy matched males as controls. They were subjected to history taking, clinical examination and estimation of serum FSH, LH, testosterone, relaxin-3 hormonal levels. The results showed that the secondary sexual characters in the patients group were at Tanner stages 1-2 and in the healthy controls at Tanner stages 3-5. The mean BMI in the patients group was significantly increased, whereas the mean levels of the span, testicular volume, serum LH, FSH, testosterone as well as relaxin-3 hormonal levels were significantly decreased compared with the healthy controls. Serum relaxin-3 levels showed significant positive correlation with the age, testis volume, span, Tanner stages, serum testosterone, FSH, LH hormones. In addition, serum relaxin-3 levels showed significant negative correlation with BMI. It is concluded that serum level of relaxin-3 hormone is an important mediator in the pathophysiological process of normal puberty being significantly decreased in males with delayed puberty.

Myosin heavy chain phosphorylation sites regulate myosin localization during cytokinesis in live cells.

Conventional myosin II plays a fundamental role in the process of cytokinesis where, in the form of bipolar thick filaments, it is thought to be the molecular motor that generates the force necessary to divide the cell. In Dictyostelium, the formation of thick filaments is regulated by the phosphorylation of three threonine residues in the tail region of the myosin heavy chain. We report here on the effects of this regulation on the localization of myosin in live cells undergoing cytokinesis. We imaged fusion proteins of the green-fluorescent protein with wild-type myosin and with myosins where the three critical threonines had been changed to either alanine or aspartic acid. We provide evidence that thick filament formation is required for the accumulation of myosin in the cleavage furrow and that if thick filaments are overproduced, this accumulation is markedly enhanced. This suggests that myosin localization in dividing cells is regulated by myosin heavy chain phosphorylation.

On the role of myosin-II in cytokinesis: division of Dictyostelium cells under adhesive and nonadhesive conditions.

We have investigated the role of myosin in cytokinesis in Dictyostelium cells by examining cells under both adhesive and nonadhesive conditions. On an adhesive surface, both wild-type and myosin-null cells undergo the normal processes of mitotic rounding, cell elongation, polar ruffling, furrow ingression, and separation of daughter cells. When cells are denied adhesion through culturing in suspension or on a hydrophobic surface, wild-type cells undergo these same processes. However, cells lacking myosin round up and polar ruffle, but fail to elongate, furrow, or divide. These differences show that cell division can be driven by two mechanisms that we term Cytokinesis A, which requires myosin, and Cytokinesis B, which is cell adhesion dependent. We have used these approaches to examine cells expressing a myosin whose two light chain-binding sites were deleted (DeltaBLCBS-myosin). Although this myosin is a slower motor than wild-type myosin and has constitutively high activity due to the abolition of regulation by light-chain phosphorylation, cells expressing DeltaBLCBS-myosin were previously shown to divide in suspension (Uyeda et al., 1996). However, we suspected their behavior during cytokinesis to be different from wild-type cells given the large alteration in their myosin. Surprisingly, DeltaBLCBS-myosin undergoes relatively normal spatial and temporal changes in localization during mitosis. Furthermore, the rate of furrow progression in cells expressing a DeltaBLCBS-myosin is similar to that in wild-type cells.

Translocation of RNA granules in living neurons.

Sorting of RNAs to specific subcellular loci occurs in diverse settings from fly oocytes to mammalian neurons. Using the membrane-permeable nucleic acid stain SYTO 14, we directly visualized the translocation of endogenous RNA in living cells. Labeled RNA was distributed nonrandomly as discrete granules in neuronal processes. The labeled granules colocalized with poly(A+) mRNA, with the 60S ribosomal subunit, and with elongation factor 1alpha, suggesting that granules represent a translational unit. A subset of labeled granules colocalized with beta-actin mRNA. Correlative light and electron microscopy indicated that the fluorescent granules corresponded to clusters of ribosomes at the ultrastructural level. Poststaining of sections with heavy metals confirmed the presence of ribosomes within these granules. In living neurons, a subpopulation of RNA granules was motile during the observation period. They moved at an average rate of 0.1 microm/sec. In young cultures their movements were exclusively anterograde, but after 7 d in culture, one-half of the motile granules moved in the retrograde direction. Granules in neurites were delocalized after treatment with microtubule-disrupting drugs. These results raise the possibility of a cellular trafficking system for the targeting of RNA in neurons.

Myosin dynamics in live Dictyostelium cells.

Conventional myosin plays a key role in the cytoskeletal reorganization necessary for cytokinesis, migration, and morphological changes associated with development in nonmuscle cells. We have made a fusion between the green fluorescent protein (GFP) and the Dictyostelium discoideum myosin heavy chain (GFP-myosin). The unique Dictyostelium system allows us to test the GFP-tagged myosin for activity both in vivo and in vitro. Expression of GFP-myosin rescues all myosin null cell defects. Additionally, GFP-myosin purified from these cells exhibits the same ATPase activities and in vitro motility as wild-type myosin. GFP-myosin is concentrated in the cleavage furrow during cytokinesis and in the posterior cortex of migrating cells. Surprisingly, GFP-myosin concentration increases transiently in the tips of retracting pseudopods. Contrary to previous thinking, this suggests that conventional myosin may play an important role in the dynamics of pseudopods as well as filopodia, lamellipodia, and other cellular protrusions.

Microtubule behavior during guidance of pioneer neuron growth cones in situ.

The growth of an axon toward its target results from the reorganization of the cytoskeleton in response to environmental guidance cues. Recently developed imaging technology makes it possible to address the effect of such cues on the neural cytoskeleton directly. Although high resolution studies can be carried out on neurons in vitro, these circumstances do not recreate the complexity of the natural environment. We report here on the arrangement and dynamics of microtubules in live neurons pathfinding in response to natural guidance cues in situ using the embryonic grasshopper limb fillet preparation. A rich microtubule network was present within the body of the growth cone and normally extended into the distal growth cone margin. Complex microtubule loops often formed transiently within the growth cone. Branches both with and without microtubules were regularly observed. Microtubules did not extend into filopodia. During growth cone steering events in response to identified guidance cues, microtubule behaviour could be monitored. In turns towards guidepost cells, microtubules selectively invaded branches derived from filopodia that had contacted the guidepost cell. At limb segment boundaries, microtubules displayed a variety of behaviors, including selective branch invasion, and also invasion of multiple branches followed by selective retention in branches oriented in the correct direction. Microtubule invasion of multiple branches also was seen in growth cones migrating on intrasegmental epithelium. Both selective invasion and selective retention generate asymmetrical microtubule arrangements within the growth cone, and may play a key role in growth cone steering events.

A study of seasonal trace element intakes and hair trace element concentrations in selected households from the Wosera, Papua New Guinea.

The trace element status of nine households from the Wosera subdistrict of Papua New Guinea was assessed. Individual weighed three-day dietary intakes were carried out in April during the hungry season when yams were not eaten and in July when yams were available. Representative staple food items analyzed 'as eaten' for energy, protein, Ca, Mn, Cu and Zn and mean daily energy and nutrient intakes calculated. Hair samples were also collected in July, washed, and analyzed for Zn, Cu and Mn by INAA. Seasonal differences in energy, protein, Ca, Fe and Mn intakes were related to changes in yam consumption. The Zn status of the male (M) and female (F) adults and children (Ch) was sub-optimal based on low median hair Zn levels (microgram/g): -F = 78, n = 8; M = 108, n = 8; Ch2-4yrs = 79, n = 8; Ch5-10yrs = 94, n = 7 and inadequate intakes of readily available Zn (mean + SD): - April M + F = 7.0 + 1.6 mg/day; July M + F = 8.2 + 1.5 mg/day; less than three percent Zn from animal products. In contrast their Mn status, as indicated by elevated median hair Mn levels (microgram/g) (F = 25.1; M = 26.3; Ch2-4yrs = 21.5; Ch5-10yrs = 15.2) was high, attributed to elevated Mn intakes (April M + F = 11.0 + 2.2 mg/day; July M + F = 7.5 + 1.4 mg/day). Median hair Cu levels (microgram/g) (F = 7.6; M = 7.5; Ch2-4yrs = 8.6; Ch5-10yrs = 7.8) and mean Cu intakes (April M + F = 2.2 + 0.4 mg/day; July M + F = 3.0 + 0.6 mg/day) were within the range noted for persons consuming predominantly plant-based diets.

A study of some aspects of food-related behaviour among a group of men.

A sample of 151 men, mainly industrial employees, completed a questionnaire to measure participation in food-related activities, recent dietary changes, and 14 personality traits from Cattell's 16 personality factor inventory. Men's food-related participation tended more to influencing rather than task-performing; it was greater among younger men and those with wives employed outside the home. Multiple regression analysis suggested that personality characteristics are of greater importance in predicting food-related participation than are demographic characteristics, including education. Factor analysis of questionnaire items on dietary change revealed five factor dimensions of dietary change; men who participated more in food-related activities reported more dietary changes in the recommended direction, particularly with respect to three factors labelled sweets/pastries, fast foods/snacks and condiments/fatty extras. Results of studies on psycho-social influences on nutrition behaviour have implications for nutrition education programs.

The trace metal status of a group of post-menopausal vegetarians.

The copper, manganese, and selenium status of 36 post-menopausal vegetarians was compared with that of a group of post-menopausal omnivores, using dietary trace element intake data, serum and hair copper levels, and hair manganese and hair selenium levels as the principal indexes. Findings of this study suggest that the copper and selenium status of these long-term vegetarian women was comparable to that of non-vegetarians, despite the high intake of dietary fiber by the vegetarian group. In contrast, the manganese status of the vegetarians, as indicated by elevated hair manganese levels, was higher, almost certainly as a result of the significantly higher manganese intake of this group.

The iron and zinc status of long-term vegetarian women.

Iron and zinc status of 56 Seventh-Day Adventist Canadian women (mean age 52.9 +/- 15.3 yr) following vegetarian diets for 19 +/- 17 yr were investigated. Energy, protein, iron, available iron, zinc, and total dietary fiber intakes were calculated from 3-day dietary records. Hemoglobin, serum iron, total iron binding capacity, serum and hair zinc concentrations were also determined. Plant products provided 92 and 77% of the total dietary iron and zinc intakes, respectively. Calculated mean daily intakes (+/- SD) for energy, protein, iron, zinc, and total dietary fiber were 1630 +/- 354 kcal, 58 +/- 14 g, 12.5 +/- 3.0 mg, 9.2 +/- 2.5 mg, and 30.9 +/- 11.0 g, respectively. Mean hemoglobin (13.1 +/- 1.0 g/dl), calculated serum transferrin saturation (37.5 +/- 12.9%), mean serum zinc (99 +/- 24 microgram/dl), and hair zinc concentrations (187 +/- 44 ppm) were all within the normal range. The iron and zinc status of these long-term Seventh-Day Adventist vegetarian women appeared adequate despite their low intake of readily absorbed iron and zinc from flesh foods and their high intake of total dietary fiber and phytate.