Testing your older patient's thyroid function

Thyroid disease cannot be diagnosed through any single test. Normal aging does affect the values of some test parameters in the elderly. When interpreting laboratory test results in the elderly, careful consideration should be given to gender, concurrent acute or chronic illness, nutritional and mental status, as well as possible recent administration of iodinated radiocontrast media and drug therapy. When these factors have been excluded and preliminary routine thyroid function are abnormal or marginally suspect, the usual standards for younger adults, slightly modified, should suffice for diagnosing both hypo-and hyperthyroidism. Patients with complications may require special measurements of serum FT4 and FT3 levels as well as the TSH and T3 response to TRH. These tests will provide additional supportive diagnostic assistance.     

Milia restricted to the eyelids

The present study was performed to estimate the prevalence of Rett syndrome in Fukui prefecture by sending questionnaires to special classes (classes for handicapped children in schools for normal children) and schools for mentally/physically handicapped children, and observing children suspected of having this syndrome on the basis of answers to the questionnaire. The subjects were girls aged 6-14 years who were attending 11 special classes and 7 schools for handicapped children. The prevalence of Rett syndrome was estimated to be 0.22 per 10,000 girls aged 6-14 years in Fukui prefecture, as of April 1, 1993. The prevalence noted in this study was lower than those found in previous studies in Japan and Western countries.     

Muscarinic acetylcholine receptors in Torpedo electric organ: effect of guanine nucleotides

The effect of guanine nucleotides on the binding properties of presynaptic muscarinic receptors has been studied in a membrane preparation from the electric organ of Torpedo marmorata by measuring the competitive displacement of the radiolabelled antagonist, [3H]quinuclidinyl benzilate, by nonradioactive muscarinic ligands. The binding of the antagonists, atropine, scopolamine and pirenzepine was to a single class of sites [slope factors (pseudo Hill coefficients) close to 1] and was unaffected by 0.1 mM GTP. The binding of the N-methylated antagonists, N-methylatropine and N-methyl-scopolamine was more complex (slope factors less than 1) but also insensitive (N-methylatropine) to 0.1 mM GTP. Agonist binding was complex and could be resolved into two binding sites with relatively high and low affinities. The proportion of high-affinity sites varied with the nature of the agonist (15-80%). Agonist binding was depressed by 0.1 mM GTP, and the order of sensitivity was oxotremorine-M greater than carbamoylcholine greater than muscarine greater than acetylcholine greater than arecoline greater than oxotremorine. The binding of pilocarpine, a partial agonist, was unaffected by GTP. With carbamoylcholine as a test ligand the GTP effect on agonist binding was half-maximal at 12 microM. GDP and guanylylimidodiphosphate produced comparable inhibition of carbamoylcholine binding, but GMP and cyclic GMP were ineffective, as were various adenine nucleotides. Analysis of agonist binding in terms of a two-site model indicates that the predominant effect of guanine nucleotides is to reduce the number of sites of higher affinity.     

Dosimetry of rhenium-186-labeled monoclonal antibodies: methods, prediction from technetium-99m-labeled antibodies and results of phase I trials

Rhenium-186 is a beta-emitting radionuclide that has been studied for applications in radioimmunotherapy. Its 137 keV gamma photon is ideal for imaging the biodistribution of the immunoconjugates and for obtaining gamma camera data for estimation of dosimetry. Methods used for determining radiation absorbed dose are described. We have estimated absorbed dose to normal organs and tumors following administration of two different 186Re-labeled immunoconjugates, intact NR-LU-10 antibody and the F(ab')2 fragment of NR-CO-02. Tumor dose estimates in 46 patients varied over a wide range, 0.4-18.6 rads/mCi, but were similar in both studies. Accuracy of activity estimates in superficial tumors was confirmed by biopsy. Prediction of 186Re dosimetry from a prior 99mTc imaging study using a tracer dose of antibody was attempted in the NR-CO-02 (Fab')2 study. Although 99mTc was an accurate predictor of tumor localization and the mean predicted and observed radiation absorbed doses to normal organs compared favorably, 186Re dosimetry could not be reliably predicted in individual patients. The methods described nevertheless provide adequate estimates of 186Re dosimetry to tumor and normal organs.     

Direct vs indirect blood pressure at rest and during isometric exercise in normal subjects

Systolic and diastolic blood pressures were measured by intraarterial means and by auscultation. Comparisons were made with simultaneously determined intraarterial catheter and auscultation measurements. Five healthy males were measured at rest and during handgrip and deadlift isometric exercises, utilizing small and large muscle mass. The data suggest that indirect systolic blood pressure is highly correlated with the direct method at rest, during handgrip and deadlift (0.8, 0.9 and 0.91 respectively) isometric exercises. Indirect diastolic blood pressure correlates well with intraarterial at rest (0.7) and during the isometric handgrip bout which utilized small muscle mass (0.8). As for the deadlift manoeuvre, the correlation coefficients between the indirect and direct methods were low. These results suggest that when utilizing large muscle mass during isometric deadlift exercise, the indirect method is not valid for assessment of diastolic blood pressure.     

Cardiac geometry and mass changes associated with pacing-induced cardiomyopathy in the dog

Olfactomedin is the major glycoprotein of the extracellular mucous matrix of frog olfactory neuroepithelium. It is responsible for the primary architecture of this extracellular matrix by forming via intermolecular disulfide bonds polymers, which are covered with evenly spaced carbohydrate groups. To study glycosylation of olfactomedin, we raised antibodies against the mature protein and antibodies against a region adjacent to an N-linked glycosylation site near its amino terminus. The latter antibodies cannot bind when this site is glycosylated and reveal precursors of olfactomedin in the perinuclear regions of Bowman's glands. In contrast, antiserum against the mature protein stains acinar regions of glands and the ciliary surface. Enzymatic deglycosylation of olfactomedin shows stepwise removal of carbohydrate and reveals a 51-kDa deglycosylated form. Our results indicate that, prior to secretion, most, if not all, of the six potential N-linked glycosylation sites of olfactomedin are glycosylated with carbohydrate moieties of about 8-10 sugar residues.     

A comparison of intra- and interpersonal interlimb coordination: coordination breakdowns and coupling strength

Intra- and interpersonal interlimb coordination of pendulums swung from the wrist was investigated. For both kinds of coordination, the steady state and breakdown of bimanual rhythmic coordination as indexed by the time series of the relative phase angle phi were studied under the manipulation of coordination mode, frequency of oscillation, and the difference in the eigenfrequencies (preferred tempos) of the individual oscillating limbs. The properties observed for both intra- and interpersonal coordination were those predicted by a dynamical model of rhythmic coordination that considers the coordinated limbs coupled to be nonlinear oscillators. Using a regression method, the coupling strengths of the coupled system were recovered. As predicted by the dynamical model, the strength of the dynamic was generally greater for the in-phase than the anti-phase mode and decreased with increasing frequency. Further, the strength of the interpersonal interlimb coupling was weaker than that of intrapersonal interlimb coupling.