Hair zinc and copper: Relationship to hair type and serum concentrations in children and adolescents

The zinc and copper serum and hair concentrations of 691 3-18-y-old girls and boys previously determined as a part of the Multicentre Study of Atherosclerosis Precursors in Finnish Children and Adolescents were further analyzed in order to find a possible association between these two zinc and copper indices. The influence of hair color and the diameter of individual hair strands on hair concentrations were studied by the analysis of covariance. Hair color and serum zinc concentrations were found to be associated with hair zinc concentrations in boys. Such an association was not found for zinc and copper concentrations in girls. Hair vs serum concentrations in different age and hair color groups did not show however, a significant relationship either in copper or in zinc concentrations. The subjects with very low or high serum zinc or copper concentrations did not usually have extreme hair concentrations and vice versa. However, there were some subjects with low or high serum concentrations associated with low or high hair concentrations.     

Actin bundles in human hair follicles as revealed by confocal laser microscopy

A confocal laser microscope was used to examine the distribution pattern of actin bundles in whole-mounts of human hair follicles stained with fluorescently labeled phalloidin. Actin bundles were found exclusively in the epithelial outer root sheath of the lower and middle portions of the follicle. In the growth stage, the lower follicle was characterized by well-developed actin bundles arranged circumferentially in the innermost and outermost cell layers of the outer root sheath. Actin bundles in the innermost cells were aligned end-to-end so that they formed complete circular bands surrounding the inner root sheath. In the outermost cells, actin bundles ran underneath the basal plasma membrane to which they attached at both ends. In contrast, in the quiescent stage, actin bundles in the lower follicle were disposed radially toward the follicle surface where they terminated perpendicular to the basal plasma membrane. In the middle follicle, circumferential actin bundles were found only in the intermediate layer of the outer root sheath throughout the hair cycle. Immunofluorescent anti-myosin and anti-α-actinin staining showed a striated pattern along actin bundles. Vinculin was localized at both ends of actin bundles, corresponding to the cell-to-cell or cell-to-substrate adherens junctions. Glycerinated follicles changed in shape on the addition of MgATP, suggesting a contraction of actin bundles. From these observations, we conclude that actin bundles in the hair follicle are comparable to stress fibers and that they serve as a tensile scaffold for the growth and integrity of the follicle. Received: 6 May 1995 / Accepted: 25 October 1995     

Very tight contact of tormogen cell membrane and sensillum cuticle: ultrastructural basis for high electrical resistance between receptor-lymph and subcuticular spaces in silkmoth olfactory hairs

A very tight contact is present between the apical membrane of the tormogen cell and the cuticle of the hair base in olfactory sensilla trichodea of Antheraea polyphemus. The contact zone is characterized by numerous hemidesmosome-like structures of the cell membrane, which closely attach the latter to the cuticle. If apically opened hairs are incubated in a LaCl3 solution, the tracer ions do not penetrate the contact zone. It is concluded that the tight contacts are the morphological correlates of the electrical isolation of the receptor-lymph space (cf. de Kramer et al., in press).     

Evidence for Alpha-MSH Binding Sites on Human Scalp Hair Follicles: Preliminary Results

Alpha-MSH, considered an important pigmentation hormone, binds to melanocytes and is thought to stimulate melanogenesis through a cyclic-AMP-dependent mechanism. The binding of alpha-MSH to follicular melanocytes has been investigated in human hair of different colors, ranging from black to blond and senile white. Hairs were plucked, the follicles were cut off, and an alpha-MSH binding assay, using a radiolabeled alpha-MSH analogue, was performed on these bulbs. As controls of each assay, fragments of hairs of the same person were used. The results show a dose-response relationship and the assay seems to be specific for alpha-MSH, because other peptides such as ACTH, beta-LPH and beta-endorphins do not compete for binding sites as alpha-MSH does. These binding sites seem to be present only on melanin synthesizing melanocytes, since the controls and follicles of senile white hair, which do not contain active melanocytes, show negative results. All the assays were performed on raw material, i.e., whole plucked hair follicles. This is the first time that binding sites for alpha-MSH have been demonstrated on human scalp hair follicles. In addition, their presence was found to be associated with active melanin production; their absence was demonstrated on senile white hair follicles.     

Calcium,magnesium, and phosphorus content of hair from two populations of rhesus monkeys

The use of hair for the assessment of human mineral nutritional status is controversial, yet has potential because of the ease of collection and storage, and the high concentration of minerals in hair. This study generated baseline values for hair macromineral content in the most commonly used primate model for human nutrition and disease, the rhesus monkey. Hair digests from monkeys in Maryland (n=98) and Puerto Rico (n=208) were analyzed by inductively coupled plasma atomic emission spectrometry (ICP-AES). Significant differences existed between the two populations for hair calcium (Ca), magnesium (Mg), and phosphorus (P) (P<0.01,P<0.001,P<0.02). Male hair had higher concentrations of Mg in specimens from the Puerto Rican population (P<0.001), whereas hair phosphorus was higher in female hair (P<0.02). There were no significant differences attributable to pregnancy status. Differences in hair content attributable to categorical age were found for Ca and Mg (P<0.001,P<0.01). Significant location differences paralleled dietary differences. These values therefore can be considered reference ranges for hair Ca, Mg, and P for free-ranging and caged rhesus monkeys. Preliminary reports of portions of these data were presented at the 69th Annual Meeting of the Federation of American Societies for Experimental Biology, April 1982, New Orleans, LA (B. M. Marriott, J. C. Smith, R. Jacobs, A. O. Jones, M. J. Kessler, and R. Rawlins,Fed. Proc. 41:770 [1982]) and in a symposium at the 6th Annual Meeting of the American Society of Primatologists, 1983, East Lansing, MI (B. Marriott, J. C. Smith, R. Jacobs, A. O. Lee Jones, R. Rawlins, and M. J. Kessler,Am. J. Primatol. 4(3):157 [1983]; B. Marriott, J. C. Smith, Jr., R. M. Jacobs, A. O. Lee Jones, R. Rawlins, and M. J. Kessler, inThe Cayo Santiago Macaques, R. Rawlins and M. J. Kessler, eds., SUNY Press, Albany, NY, pp. 219–231 [1986]).     

Action spectrum for the blue-light-dependent morphogenesis of hair whorls in Acetabularia mediterranea

In young Acetabularia mediterranea Lamouroux (=A. acetabulum (L.) Silva) the formation of the lateral hair whorls can be induced by a short pulse of blue light after continuous red preillumination. In this paper we describe the experimental conditions for optimum response and the properties of the action spectrum. The probit of the cells which eventually form hair whorls is linearly correlated to the logarithm of the incident quanta of blue light. Parallel fluence-response curves for all wavelengths indicate the involvement of only one photoreceptor pigment. The action spectrum shows no effectiveness of wavelengths above 520 nm, a high action peak at 470 nm and two lower ones at 425 and 370 nm, and is in accordance with those of cryptochrome-like photoreceptors.     

Response characteristics of single trochanteral campaniform sensilla in the stick insect, Cuniculina impigra

ABSTRACT. The campaniform sensilla on the trochanter of the stick insect, Cuniculina impigra Redtenbacher, were stimulated by slightly bending the leg in the horizontal plane. Single sensory units in the nerve were recorded using glass microelectrodes. These units can be classified into tonic and phasic-tonic receptors. In both cases there were units which increased their discharge frequency during forward movement of the femur, and units which responded to backward movement. No purely phasic receptors were found.     

Host recognition in the pupal parasitoid Trichopria drosophilae: a morpho-functional approach

The diapriid wasp Trichopria drosophilae Perkins (Hymenoptera: Diapriidae) attacks and develops in puparia of the common fruit fly, Drosophila melanogaster Meigen (Diptera: Drosophilidae). Host recognition of T. drosophilae was studied using both a morphological and behavioural approach. Scanning and electron microscopical observations of female parasitoid antennae showed the presence of two types of sensilla, which we named MGS1 and MGS2. The former are present on the ventral side of both the apical (A11) and sub‐apical (A12) antennomeres, while the latter occur only on A12. Ultrastructural features suggest a gustatory function for these sensilla. Arena bioassays using intact or antennaectomised females and intact host puparia showed that MGS2 are necessary for achieving host acceptance. Further bioassays, where the host's anterior spiracles were covered with wax, led to a very low level of host acceptance. We suggest that the secretion produced by glands associated with the anterior spiracles act as a contact kairomone, which has to be perceived by MGS2 in order to elicit host recognition. The removal of both the female apical antennomeres (A12) led to the failure of the parasitoid to recognize its host.     

Lehr's fields of campaniform sensilla in beetles (Coleoptera): Functional morphology. III. Modification of elytral mobility or shape in flying beetles

Some flying beetles have peculiar functional properties of their elytra, if compared with the vast majority of beetles. A “typical” beetle covers its pterothorax and the abdomen from above with closed elytra and links closed elytra together along the sutural edges. In the open state during flight, the sutural edges diverge much more than by 90°. Several beetles of unrelated taxa spread wings through lateral incisions on the elytra and turn the elytron during opening about 10–12° (Cetoniini, Scarabaeus, Gymnopleurus) or elevate their elytra without partition (Sisyphus, Tragocerus). The number of campaniform sensilla in their elytral sensory field is diminished in comparison with beetles of closely related taxa lacking that incision. Elytra are very short in rove beetles and in long-horn beetles Necydalini. The abundance of sensilla in brachyelytrous long-horn beetles Necydalini does not decrease in comparison with macroelytrous Cerambycinae. Strong reduction of the sensory field was found in brachyelytrous Staphylinidae. Lastly, there are beetles lacking the linkage of the elytra down the sutural edge (stenoelytry). Effects of stenoelytry were also not uniform: Oedemera and flying Meloidae have the normal amount of sensilla with respect to their body size, whereas the sensory field in the stenoelytrous Eulosia bombyliformis is 5–6 times less than in chafers of the same size but with normally linking broad elytra.