Allergic contact dermatitis from "titanium" spectacle frames.
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Aged↗
Biomedical subjects
W B Stern
Publications and source records attributed to W B Stern.
X-ray diffraction studies on the lattice perfection of human bone apatite (Crista iliaca).
The lattice perfection of human bone apatite (iliac crest of 117 individuals aged 0-90 years) was systematically investigated by means of combined X-ray diffraction procedures--profile fitting and line-broadening analysis--correlated with age, sex, type of tissue (corticalis, spongiosa), and position (superior, middle, and inferior) for different crystallographic directions [length axis using reflection (002), basal plane by means of reflections (300), (210), and (310)]. Bone specimens within age group 0-30 were strongly affected by an increased crystallinity in the direction of the c-axis (domain size increasing by 5-7 nm, strain decreasing respectively), whereas in the direction of the a-axis crystallinity decreased significantly (domain size shortening by 5-7 nm, strain increasing respectively) in correlation with some heteroionic substitutions within the apatitic structure. Within age group 30-80 a certain balance seemed to exist between processes of ordering and disordering such that statistically only a slight increase of crystallinity within the basal plane was observed. Age as main fixed effect was highly significant for all investigated parameters. Crystallinity was well correlated with type of tissue (corticalis, spongiosa) in the direction of the length axis of the bone crystallite.
Adolescent↗
Crystallographic and chemical analysis of human bone apatite (Crista Iliaca).
Crystallographic (X-ray diffraction) and chemical (X-ray fluorescence and combustion analysis) investigations on bone microsamples (human iliac crest of 111 individuals aged 0-90 years) reveal that certain crystallographic and chemical parameters (lattice parameters, crystallinity, chemical compounds, biomineralic fraction...) are closely related to aging and type of tissue (corticalis and spongiosa). In juvenile bone [0-25y], the biomineralic fraction rises significantly, as does crystallinity and area of apatite (002)-reflection indicating a growth of crystal size. The second main age interval [25-50y] does not display statistically relevant variations with age. The third main age group [50-90y] is characterized by large chemical variations, probably due to overlapping effects of age and declining health.
Adolescent↗
Crystallographic lattice refinement of human bone.
X-ray diffraction studies on bone microsamples (human iliac crest of 87 individuals aged 0-90 years) reveal that certain crystallographic parameters such as unit cell volume of bone apatite, and half-width of (002)-reflection are well correlated with age and with type of tissue (corticalis and spongiosa). Similar to inorganic apatite, the lattice parameters of bone apatite are intensely affected by ionic substitutions and vary mainly due to exchange of hydroxyl- and carbonate-apatite and, to a minor extent, of fluor- and chlorapatite.
Adolescent↗
Computed tomography of the clinically negative neck.
Members of the New York Head and Neck Society conducted a multi-institutional review correlating preoperative computed tomography (CT) of the neck with postoperative pathology in 59 patients with squamous cell carcinoma of the oral cavity, pharynx, and larynx, without palpable lymphadenopathy. All underwent CT followed by surgery that included partial or complete cervical lymphadenectomy. Sixteen (28%) patients had occult cervical metastases including 6 (17%) of 36 patients with "early stage" (T1 and T2) primary tumors and 10 (44%) of 23 patients with "advanced" (T3 or T4) lesions. There was agreement of CT scan findings with presence or absence of metastatic disease in 41 (69%) of 59 studies, with sensitivity 38%, and with specificity 81%. Findings of central lucency and nodal confluence were highly reliable indicators of malignancy, whereas nodal size bore a less direct relationship. Intravenous contrast medium was useful for anatomical delineation, but not for identification of malignancy. Review of films by a single radiologist did not produce greater diagnostic accuracy than the original interpretations. The authors conclude that while it is not possible to identify all instances of cervical node involvement, employment of CT in addition to physical examination and prognostication based on primary tumor stage will facilitate appropriate selection of patients for elective treatment of the neck.
Carcinoma, Squamous Cell↗