Migration of the dominant pacemaker region in the rat sinoatrial node

"Early onset sarcoidosis" is a chronic granulomatous disease occurring in children younger than 5 years of age, and characterized by a classic symptom triad consisting of skin, eye and joint lesions, with on rare occasion pulmonary involvement. The disorder often goes unrecognized because of its rarity and, since polyarthritis and uveitis are the predominant symptoms, most of these children are misdiagnosed as having juvenile chronic arthritis (JCA). A child with erythema nodosum at 7 months of age, later diagnosed as JCA and definitively recognized as "early onset sarcoidosis" is reported. This case shows that, whenever possible, a biopsy showing the typical picture of sarcoid granulomas is crucial to distinguish these clinical conditions.     

MIRD pamphlet No. 17: the dosimetry of nonuniform activity distributions--radionuclide S values at the voxel level. Medical Internal Radiation Dose Committee

The availability of quantitative three-dimensional in vivo data on radionuclide distributions within the body makes it possible to calculate the corresponding nonuniform distribution of radiation absorbed dose in body organs and tissues. This pamphlet emphasizes the utility of the MIRD schema for such calculations through the use of radionuclide S values defined at the voxel level. The use of both dose point-kernels and Monte Carlo simulation methods is also discussed. PET and SPECT imaging can provide quantitative activity data in voxels of several millimeters on edge. For smaller voxel sizes, accurate data cannot be obtained using present imaging technology. For submillimeter dimensions, autoradiographic methods may be used when tissues are obtained through biopsy or autopsy. Sample S value tabulations for five radionuclides within cubical voxels of 3 mm and 6 mm on edge are given in the appendices to this pamphlet. These S values may be used to construct three-dimensional dose profiles for nonuniform distributions of radioactivity encountered in therapeutic and diagnostic nuclear medicine. Data are also tabulated for 131I in 0.1-mm voxels for use in autoradiography. Two examples illustrating the use of voxel S values are given, followed by a discussion of the use of three-dimensional dose distributions in understanding and predicting biologic response.     

Successful medical treatment of severely decompensated Wilson disease

Delayed response to medical treatment sometimes leads to unnecessary liver transplantation in patients with severely decompensated Wilson disease. We report the course of five patients (mean age 13.4 years, range 11 to 15 years) with severely decompensated Wilson disease who were successfully treated medically. Prothrombin time improved after a minimum of 1 month and returned to normal within 3 months to 1 year or more.     

General treatment of competitive binding as applied to the potentiometric ion probe technique: application to the interaction of nonsteroidal anti-inflammatory drugs with bovine serum albumin

The binding of naproxen, ketoprofen, phenylbutazone, salicylic acid, azapropazone, and indobufen to bovine serum albumin was studied by applying the potentiometric ion probe technique. An ion-selective electrode for the ion probe 1-anilino-8-naphthalene-sulfonate was utilized for the purposes of this study. A modified site-oriented competitive binding model was used for the estimation of the drugs' binding parameters, considering different number of binding sites on the competing binding class(es) for the probe and the drug. Calculations were based exclusively on the concentration data of the free probe. The model's ability for accurate estimations of binding parameters was evaluated by simulation studies. The following values of binding parameters were found at 25 degrees C for the drugs under study; naproxen, n1 = 9.1, k1 = 9.4 x 10(5) M-1; ketoprofen, n1 = 8.8, k1 = 10.8 x 10(5) M-1; phenylbutazone, n1 = 3.2, k1 = 1.4 x 10(5) M-1; salicylic acid, n1 = 2.6, k1 = 1.8 x 10(5) M-1, n2 = 21.5, k2 = 1.0 x 10(4) M-1; azapropazone, n1 = 0.5, k1 = 7.8 x 10(5) M-1, n2 = 26.3, k2 = 1.9 x 10(4) M-1; indobufen, n1 = 5.8, k1 = 5.8 x 10(5) M-1, n2 = 19.9, k2 = 3.8 x 10(5) M-1, where ni the number of binding sites of the i class and ki the corresponding association constant.     

Associated anomalies in individuals with polydactyly

Evidence from the last 10 years suggests that melatonin may influence the cardiovascular system. Vascular melatoninergic receptors/sites have been demonstrated and are functionally linked with vasoconstrictor or vasodilatory effects of low (10(-9)-10(-7) M) and high (10(-6)-10(-3) M) melatonin concentrations respectively. Furthermore several other properties of the neurohormone (e.g. sympathetic inhibition) could contribute to cardioprotection. In vivo melatonin beneficially affects the rat cerebrovascular circulation and protects the rat heart following myocardial ischaemia. In this regard, preliminary clinical data report some alteration of the melatoninergic system in human stroke and coronary heart disease. Finally, the suprachiasmatic nucleus and possibly the melatoninergic system may modulate cardiovascular rhythmicity. Clinical cardiovascular data on melatonin treatment are very scarce; the effects of a therapy modulating the melatoninergic system on cardiovascular haemodynamics and rhythmicity under several physiopathological conditions need to be further explored together with the possible impact on cardiovascular morbidity and mortality.     

Occupation and breast cancer mortality in a prospective cohort of US women

We report the isolation of the functional form of the Ca-ATPase from porcine cardiac sarcoplasmic reticulum (SR) membranes, taking advantage of the ability of this enzyme to bind to the nucleotide site affinity dye, Reactive Red 120. Conditions that optimize the solubility and functional stability of the cardiac Ca-ATPase in detergent during the purification procedure are essential to its recovery. The purified Ca-ATPase migrates as a single band on Coomassie blue-stained polyacrylamide gels and exhibits high specific activity (2.5 IU at 25 degreesC) and functional stability. Similar enrichment of the Ca-ATPase estimated from either relative amounts of the 100-kDa protein band on polyacrylamide gels or steady-state concentrations of phosphorylated enzyme intermediate (E-P) demonstrate that neither nonfunctional Ca-ATPases nor non-Ca-ATPase proteins migrating with an apparent molecular weight of 100 kDa constitute a significant fraction of these preparations. Steady-state levels of E-P are 1.3 and 8.6 nmol/mg protein, respectively, for native cardiac SR membranes and the final purified fraction. These values, in comparison to the maximum value (9.1 nmol/mg) for the 110-kDa protein, agree well with estimates of total Ca-ATPase abundance from gel densitometry for both preparations and indicate full site reactivity, i.e., one phosphorylation site for each 110-kDa cardiac Ca-ATPase polypeptide chain.     

Program specification: a precursor to program monitoring and quality improvement. A case study from Boysville of Michigan

The reaction of synthetic DOPA melanin (DM) with lactoperoxidase (LPO), hydrogen peroxide, and nitrite (NO2-) has been investigated using EPR. We observed that in the presence of nitrite LPO/H2O2 generated large amount of melanin radicals, as evidenced by a strong, up to 11-fold, increase in the intensity of the melanin EPR signal. In contrast, when nitrite was omitted the increase was much less, ca. 30%, which, nevertheless, indicates that DM can be metabolized directly by LPO/H2O2. When the nitrite was present, the concentration of melanin radicals was linearly dependent on [NO2-] (for [NO2-] <5 mM), and increased when [LPO] and [H2O2] increased (at constant [NO2-]). We propose that the mechanism for the generation of melanin radicals by the LPO/H2O2/nitrite system involves oxidation of NO2- by LPO/H2O2 to a reactive metabolite, most likely the nitrogen dioxide radical (.NO2), which subsequently reacts with melanin 5,6-dihydroxyindole subunits producing the respective semiquinone radicals. Because melanin and .NO2 generating systems (nitrite, peroxidase enzymes, hydrogen peroxide) may coexist in cells in vivo, our results suggest that melanin could function as a natural scavenger of this highly reactive nitrogen species. This property may be relevant to the physiological functions of the melanin pigments in vivo.     

Grid versus non-grid techniques for the detection of pulmonary nodules in a chest phantom

A partial chest phantom was constructed to compare two commonly employed radiographic techniques, 70 kVp without a grid and 120 kVp with a grid, for the detection of pulmonary nodules. The phantom consisted of human ribs embedded in paraffin, the lungs of a dog injected with silicone rubber, a tissue equivalent wax heart and beeswax nodules. The nodules ranged in size from 3-7 mm. A series of 120 films was exposed, half with each technique, and the films were interpreted by three senior residents and seven staff radiologists. More nodules of all sizes except 3 mm were detected with the 120 kVp technique. The 3 mm nodules were rarely detected with either technique. The disadvantages of the 120 kVp technique were an approximate 50 percent increase in patient exposures and almost twice as many false-positive nodule detections.