Sonographically measured hyoid bone displacement during swallow in preschool children: a preliminary study.

PURPOSE: This study explored normative parameters regarding maximum displacement of hyoid bone movement during spontaneous swallows using ultrasound (US) in a sample of healthy preschool children. We hypothesized that consistency and bolus size would influence hyoid movement, but gender would not be a factor. METHODS: Parental questionnaire responses and sensorimotor examinations were utilized to determine subject eligibility. Subjects were presented randomized bolus volumes of thin liquids/puree via a spoon while the US probe was placed submentally in the midsagittal plane. Maximum hyoid bone displacement was determined following a frame-by-frame analysis of the US recording during spontaneous swallowing of discrete bolus sizes. RESULTS: Twenty-nine subjects produced 346 swallows that were subsequently analyzed. Significant findings (p < 0.05) included a gender effect with the smallest bolus of liquids presented. Bootstrap estimates based on our sample revealed that 99% of preschool children would present with hyoid bone displacement within 0.3 cm of our sample. CONCLUSIONS: Based on our early experience, we were able to observe and measure changes in hyoid bone position during swallowing in preschoolers, which may be gender related. More studies are needed to corroborate our findings. In addition, comparisons of maximum hyoid displacement are warranted in subjects that present with feeding delays.

'Venus trapped, Mars transits': Cu and Fe redox chemistry, cellular topography and in situ ligand binding in terrestrial isopod hepatopancreas.

Woodlice efficiently sequester copper (Cu) in 'cuprosomes' within hepatopancreatic 'S' cells. Binuclear 'B' cells in the hepatopancreas form iron (Fe) deposits; these cells apparently undergo an apocrine secretory diurnal cycle linked to nocturnal feeding. Synchrotron-based µ-focus X-ray spectroscopy undertaken on thin sections was used to characterize the ligands binding Cu and Fe in S and B cells of Oniscus asellus (Isopoda). Main findings were: (i) morphometry confirmed a diurnal B-cell apocrine cycle; (ii) X-ray fluorescence (XRF) mapping indicated that Cu was co-distributed with sulfur (mainly in S cells), and Fe was co-distributed with phosphate (mainly in B cells); (iii) XRF mapping revealed an intimate morphological relationship between the basal regions of adjacent S and B cells; (iv) molecular modelling and Fourier transform analyses indicated that Cu in the reduced Cu(+) state is mainly coordinated to thiol-rich ligands (Cu-S bond length 2.3 Å) in both cell types, while Fe in the oxidized Fe(3+) state is predominantly oxygen coordinated (estimated Fe-O bond length of approx. 2 Å), with an outer shell of Fe scatterers at approximately 3.05 Å; and (v) no significant differences occur in Cu or Fe speciation at key nodes in the apocrine cycle. Findings imply that S and B cells form integrated unit-pairs; a functional role for secretions from these cellular units in the digestion of recalcitrant dietary components is hypothesized.

The surgical correction of protuberant ears.

While prominent ears are considered a sign of good fortune in the Far East, Western society looks upon prominent ears in a far less positive manner. Children with prominent ears are often the subjects of verbal and at times physical abuse by their peers, resulting in adverse psychological effects. Advances in otoplasty have made it possible not only to pin back the ears, but also to reshape them, reduce their size, or make them more symmetrical. For a dermatologic surgeon, an otoplasty may be an unfamiliar surgical procedure, however, the surgery itself does not significantly differ from ear wedges or cartilage removal procedures for skin cancer, procedures with which the dermatologic surgeon is quite familiar.

DNA repair in skin of lupus erythematosus following in vivo exposure to ultraviolet radiation.

The in vivo repair of pyrimidine dimers induced in the DNA of skin of 9 patients diagnosed as systemic or discoid lupus erythematosus (LE) was measured. A small area of the buttock was exposed to radiation emitted from a Burdick UV-800 sunlamp. The number of pyrimidine dimers was measured by incubating the epidermal skin DNA with UV-specific endonuclease and sedimenting the DNA through alkaline sucrose gradients. The initial number of dimers induced following sunlamp exposure was 7.6 +/- 1.8 per 10(8) daltons DNA. The level of photorepair was measured by illuminating an area of the skin with greater than 450-nm radiation immediately following sunlamp exposure. We found that 56.5 +/- 9.5% of the dimers are photorepaired with 5 min of illumination. Excision repair was measured in an area of the skin covered for 2 and 24 h postirradiation. Approximately 44 and 81% of the dimers induced immediately following sunlamp exposure were removed at these respective times. These observations in LE are similar to those observed in the skin of normal individuals.

Interleukin-1 beta stimulates somatostatin biosynthesis in primary cultures of fetal rat brain.

Interleukin-1 (IL-1), a secretory product of activated macrophages and many other cell types, is an important mediator of the acute phase reaction to infection and to endotoxin administration. Previous reports that GH and TSH secretion are decreased following injection of endotoxin or IL-1 led us to test the hypothesis that IL-1 acts by releasing increased amounts of somatostatin (SS), a hypothalamic factor inhibitory of both GH and TSH release. Primary cultures of dispersed fetal rat diencephalic cells were found to contain increasing amounts of immunoreactive SS in both cells and media after addition of recombinant human IL-1 beta. This increase was detectable at 24 hours and continued for up to 6 days, the longest time interval tested. Increased content of SS peptide was accompanied by marked increases in SS mRNA. These changes were dose-related, the lowest effective dose being 10(-10) M. In contrast to the long term response, exposure of the cells to IL-1 beta for one hour had only minimal stimulating effects on somatostatin release. These data indicate that IL-1 beta is neurotrophic for the somatostatinergic neuron, an action that may be responsible at least in part, for the neuroendocrine response to infection.

Cytokine modulation of pituitary hormone secretion.

A rapidly expanding body of evidence indicates that cytokines do indeed regulate pituitary hormone secretion. Recent studies with cytokines in vivo and in vitro support the idea that cytokines are the principal mediators of the neuroendocrine responses previously observed in infectious and inflammatory states. The dominant route of this modulation appears to be via the brain and hypothalamus, although a role for direct effects on the pituitary has not been excluded. These effects may be mediated by circulating cytokines, endogenously produced cytokines, or both. A number of receptor systems and second messengers may be involved, and a role for arachidonate metabolite pathways appears particularly likely. A final question: Of what use to the organism is the ability of immune activation to control pituitary hormone secretion? For some pituitary secretions there is a reasonable basis for speculation. Glucocorticoids serve to limit the severity of immune responses and recent studies argue that defects in this pathway permit the expression of autoimmune disease. Inhibition of thyroid function may limit the catabolic side effects of infectious illness. Stimulation of growth hormone could have the same effect, and growth hormone and prolactin may serve to enhance some immune responses.

Morphological study of early phases of platelet adhesion to foreign surfaces: effect of calcium.

The role of calcium in the interfacial reactions occurring during the early phases of blood contact with glass surfaces has been studied using a rheologic technique that permits enumeration of adherent platelets as well as ultrastructural visualization of the blood-glass interface by both transmission and scanning electron microscopy . In the presence of calcium, platelets adhere to the glass surface at a rapid rate. Within 4 minutes, most of the adherent platelets have lost their normal discoid shape and show pseudopod formation and cytoplasmic spreading. These platelets conform with the glass surface and show central apposition of platelet organelles similar to that seen in activated platelets. Fibrin strands and platelet aggregates are also seen. Chelation of calcium using sodium citrate or EDTA results in decreased platelet adhesion or retention to glass. Platelets that are adherent to glass in the presence of citrate and EDTA retain their discoid shape, although an occasional platelet may show pseudopod formation and centralization of organelles. Calcium appears to be an important factor governing the adhesion of platelets to glass and appears to exert this effect on the platelets themselves in their plasma milieu and not on the preceding adsorption of plasma proteins.

Somatostatin regulation by cytokines.

Inflammatory states are associated with nervous and neuroendocrine responses, which appear to be mediated through the actions of cytokines. Since endotoxin treatment in the rat is associated with declines in thyrotropin (TSH) secretion and growth hormone (GH) secretion, changes that may be explained by stimulation of hypothalamic somatostatin (SRIF), the effects of cytokines on SRIF were examined. In an in vitro model system consisting of fetal rat diencephalic cells interleukin-1 (IL-1), tumor necrosis factor (TNF) and interleukin-6 (IL-6) were found to stimulate the synthesis and release of SRIF. This effect developed slowly over 24 hours and was dose- and time-dependent. Acute release of SRIF over periods up to 1 hour was not found. The mechanism of cytokine stimulation of SRIF is not known. Since the depletion of glial cells in the cultures inhibits the effect, mediators that depend on the presence glia may be involved. The ability of cytokines to stimulate brain SRIF is likely to prove relevant to our understanding in many areas, including brain development, brain responses to injury, and neuroendocrine changes in chronic illness.

Gomori-positive astrocytes in primary culture: effects of in vitro age and cysteamine exposure.

Gomori-positive astrocytes have been identified in the periventricular brain in situ and in diencephalic explants on the basis of their endogenous peroxidase activity, affinity for chrom alum hematoxylin, and orange-red autofluorescence. To facilitate analyses of their functional properties, we sought to identify these cells in dissociated fetal rat brain cultures. Astrocytes containing cytoplasmic inclusions with the above tinctorial and fluorescent properties represented less than 1% of cultured astrocytes at day 10 in vitro (DIV). There was a marked increase in the fraction of Gomori-positive astrocytes and their granule content between 10 and 46 DIV. As in situ, the peroxidase activity appeared to be non-enzyme-mediated insofar as it catalyzed diaminobenzidine oxidation over a wide range of pH (3-11) and could not be inhibited by tissue preheating or the catalase inhibitor, aminotriazole. Metalloporphyrins probably mediate both the pseudoperoxidase activity and autofluorescence in these cells. Cysteamine and cystamine, but not ethanolamine or L-cysteine, induced a massive accumulation of Gomori-positive astrocytes when administered from DIV 6-18. Alterations of the redox microenvironment or induction of porphyrin/heme biosynthetic enzymes may be the mechanisms responsible for this cyst(e)amine effect. Dissociated rat brain culture enriched for Gomori astroglia should provide ample opportunity to investigate the functional properties of these cells.

Quadriceps muscle strength and dynamic stability in elderly persons.

Several measures of dynamic stability during two functional activities correlated to quadriceps femoris muscle strength. A total of 34 disabled elders (aged 60-88) living in the Boston area consented to maximum isometric quadriceps muscle strength testing, chair rise and gait analysis. During chair rise, quadriceps strength significantly correlated with maximum upper body vertical linear momentum, r=0.53, P<0.005, anterior posterior linear momentum, r=0. 38, P<0.05, and the time to complete the chair rise, r=-0.48, P<0.05, n=29. Stride length and gait velocity correlated (r=0.56, P<0.001 and r=0.51, P<0.002, n=34) with quadriceps muscle strength. The maximum range of whole body anteroposterior (A/P) linear momentum during gait also correlated with quadriceps strength (r=0.47, P=0. 004, n=31). Dynamic stability during chair rise and gait, at preferred speed, correlates directly with quadriceps femoris muscle strength in functionally limited elderly individuals. In our sample, elders performed one of three movement strategies to arise from a chair, and quadriceps strength did not statistically differ between the chair rise strategy groups. However, persons with the greatest quadriceps strength values were more stable regardless of which chair rise strategy they performed. Our data indicate that clinicians should not suggest that patients use compensatory momentum inducing locomotor strategies unless the patient has sufficient strength to control these induced forces.

Vestibulopathy and age effects on head stability during chair rise.

It is unknown how vestibular dysfunction and age differentially affect balance control during functional activities. The objective of this study was to gain insight into the effects of age and vestibulopathy on head control when rising from a chair. Head relative to trunk (head-on-trunk) sagittal plane angular and linear control strategies were studied in patients with bilateral vestibular hypofunction (BVH) and in healthy subjects aged 30-80 years. A two-way analysis of variance was used to compare head-on-trunk kinematics by age (young vs elderly) and diagnosis (healthy vs BVH) at the time of liftoff from the seat. Angular control strategies differed with age but not diagnosis: young (healthy and BVH) subjects stabilized head rotations in space while elderly (healthy and BVH) subjects stabilized head rotations on the trunk. In contrast, linear control strategies differed by diagnosis but not age: BVH subjects (young and old) allowed a greater rate of head-on-trunk translation while healthy subjects (young and old) inhibited such translations. Young BVH subjects stabilized head-in-space rotations (as did young healthy subjects) without a functioning vestibular system, suggesting cervicocollic reflex and/or other sensory compensation for vestibular loss. Elderly BVH subjects stabilized head rotation with respect to the trunk, as did healthy elders, but did not stabilize head-on-trunk translations, suggesting a reliance on passive mechanical responses of the neck to sense head movements. We conclude that compensation strategies used by patients with vestibulopathy are age-dependent and appear to be more tractable in the younger BVH patient.

Dermatologic surgery into the next millennium, Part III.

Face-lift procedures and blepharoplasties are performed as in-office surgeries. Either local sedation or conscious sedation is used, and the patient's vital signs are carefully monitored. To avoid complications, the patient is followed closely postoperatively. It is highly suggested that the patient receives a medical clearance prior to undergoing either of these procedures.

Dermatologic surgery into the next millennium: Part I.

Dermatologic cosmetic surgery is a subspecialty of dermatology that has recently been developed. In this four-part series, we describe many of the procedures performed in our ambulatory surgery setting. We also highlight the significant changes in the techniques and treatment environments for these procedures over the past three decades. In part one, we focus on liposuction and face lift operations. Patients increasingly expect less invasive procedures, decreased "down time," and superior results. These expectations create a greater demand for the dermatologic surgeon. The trends and prospects for dermatologic cosmetic surgery in the next millennium are illustrated.

Dermatologic surgery into the next millennium, part II.

This is the second article in a 4-part series on dermatologic surgery. This section provides detailed information about filling agents and botulinus toxin A. The filling agents discussed here are frequently used in our office. It is emphasized that meticulous technique and patient selection predict a good cosmetic result. To select the right agent, patient safety must be a priority.

A 56-year-old woman with recurrent episodes of weakness and hypoglycemia.

The differential diagnosis for a 56-year-old woman with recurrent episodes of weakness and hypoglycemia is discussed in the setting of a clinicopathological conference at the Louisiana State University Medical Center in Shreveport, Louisiana. The diagnostic approach to the workup of a patient presenting with hypoglycemia is outlined.

Clinical implications of design characteristics, flow rates, and suction pressure attributes in commercially available training cups.

OBJECTIVE: Transitioning from a bottle to open cup drinking can be a lengthy process in typical development. Children are often introduced to training cups during this period. Due to a lack of standardization in commercially available training cups, differences in design and performance characteristics may potentially create medical complications in developmentally delayed individuals. Our purpose is to report commercially available training cup design characteristics, residual fluid, flow rates, and suction pressures and discuss the potential clinical implications. DESIGN: A testing apparatus was developed to determine suction pressure and flow rate. Nine commercially available training cups were tested by two independent research teams. Experimental data were filtered and then fit with a linear approximation determined by a least squares method. RESULTS: Commercially available cups exhibited extensive variability in design parameters, suction pressure, rate of flow, and residual fluid. CONCLUSION: The extensive variability of design and function within current commercially available cups has clinical implications for children with development delays such as the ingestion of air and aspiration. Studying the variability of existing training cup performance identifies characteristics that impact cup function which can influence future cup design.