Biomedical subjects
Publications and source records attributed to H Weiss.
Colonoscopic appendicography is a simple diagnostic measure for surveying the position and anatomical qualities of the appendix. It is complementary to ileocolonoscopy and allows a decision to be made as to whether right lower abdominal pain is due to appendicular disease or not.
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The rate of complications in fine needle puncture was ascertained by an inquiry conducted among the members of the German Association of Ultrasound in Medicine (DEGUM). 337 complications had been registered in a total of 66,397 punctures, corresponding to a percentage of only 0.51%. 294 of these were mild, i.e. not requiring therapy (0.44%), 38 severe (0.057%) and 5 complications were fatal and resulted in death (0.0075%). Differences were slight in respect of the frequency of complications with reference to puncture technique and type of needle employed. Most complications were seen in fine needle puncture for obtaining histological material (0.67%) (cutting biopsy needles), compared with 0.54% in therapeutic puncture and 0.46% for obtaining cytological material. Among the puncture techniques, the use of a puncture transducer resulted in more complications (0.72%) compared with sonographically guided puncture (0.59%) and puncture in full view with 0.43%. Punctures with/fatal outcome had been conducted in 4 out 5 cases with so-called cutting biopsy needles. Results are identical with those obtained in the U.S.A. on a comparative basis. Compared with punctures with so-called coarse needles, fine needle puncture results in fewer complications on account of the smaller needle caliber. As with every intensive method, however, complications must be taken into account even with fine needle puncture.
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Electroretinographic (ERG) investigations were performed in three AIDS patients. The first had cotton wool-like spots in both eyes (AIDS "retinopathy"). The second presented with the same changes in his right eye and an acute cytomegalovirus (CMV) in his left eye. In the third patient signs of healed peripheral retinochoroiditis were found. In CMV retinitis the retinal damage demonstrated by ERG correlated well with the ophthalmoscopic findings. As the ERG improved concurrently with Ganciclovir therapy, retinal function can be monitored by means of ERG controls. In the cases of AIDS "retinopathy" with only a few cotton wool-like spots and with healed peripheral retinochoroiditis, pronounced changes in the ERG were seen regularly; these were most probably caused by ischemia of the inner retinal layers.
Humoral and cellular immunity were evaluated in 10 patients with Darier's disease. The mean levels of serum immunoglobulins, serum complement, peripheral macrophages, and peripheral B and T lymphocytes were within normal limits. Secretory IgA was present in all patients studied. Skin tests for delayed hypersensitivity revealed complete anergy in one of the eight patients tested. Lymphocyte transformation tests revealed statistically significant enhanced responsiveness to both PHA and ConA mitogens in several concentrations studied. These findings may suggest either the existence of alterations in immunoregulation of lymphocyte subpopulations in Darier's disease or may be limited to alterations in membrane functions of certain lymphocyte subpopulations which can be detected only in vitro. The role that such immunologic aberrations may play in the pathogenesis of Darier's disease is still obscure.
DNA distributions were recorded flow cytometrically (FCM) in human normal, precancerous (P1 characterized by ductal hyperplasia and/or lobular hyperplasia, and P2 characterized by carcinomata lobularia in situ and intraductal carcinoma) and malignant breast tissues. Heparin, a polyanion, mediated two changes: (a) a time-dependent increase in fluorescence intensity (IFI) considered to be inversely proportional to the proliferative activity. IFI was significantly lower in carcinomas than in P2, in normal and in P1 tissues; it identified a highly and a poorly heparin-sensitive subgroup of carcinomas, which differed in respect to histological type and tumor stage distribution; (b) a time-dependent increase in the percentage of recorded DNA aneuploid cells (IAC) at the expense of DNA diploid cells in mixed cell population. IAC is considered to correspond to cell membrane permeability. DNA aneuploid cell populations homogeneous in respect to DNA - index (DI) seem to be heterogeneous in respect to cell membrane function. Duct carcinomas showed significantly higher IAC than lobular carcinomas.
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Following a report that nortriptyline was found useful in the control of enuresis in adults, presumably as an anticholinergic, its likely mechanism of action and apparent bladder specificity have now been investigated in vitro. The ratios of anticholinergic potencies (reciprocal of dissociation contents, Ki) for four different tricyclic antidepressants, derived from competitive binding assays with (-)[3H]QNB in tissue homogenates, in the order (human) detrusor muscle/ileal longitudinal muscle/caudate, are as follows: Nortriptyline, 5/4/7; desipramine, 2/1/5/; clomipramine, 4/3/27; amitriptyline, 25/14/56. The apparent selective effect of nortriptyline on the bladder cannot be ascribed to its higher affinity to bladder receptors. Still, this drug is the least discriminatory of the four. Hence, at a given concentration, it is expected to affect tissue embodying a low density receptor pool sooner than tissue having a large receptor reserve. The ratios of the densities of (-)[3H]QNB binding sites in the order detrusor muscle/ileal muscle/cortex is 1/3/5, supporting the present contention. In the guinea-pig, the ratios of the anticholinergic potency in the order bladder/proximal ileum/distal ileum/cortex are as follows: Nortriptyline, 25/5/6/33; desipramine, 8/2/2/14; amitriptyline, 100/14/20/100; clomipramine, 17/3/5/33. Also, the ratios of the densities of binding sites are 1/6/5/2. Hence, data derived from assays in the guinea-pig are not representative of those derived from human tissue.
The primary structure of the cytochrome c1 subunit of ubiquinol-cytochrome-c reductase from mitochondria of Neurospora crassa was determined by sequencing the cDNA of a bank cloned in Escherichia coli. From the coding region the sequence of 332 amino acids, corresponding to the molecular mass of 36,496 Da, was derived for the precursor protein. The mature protein, the N terminus of which was previously sequenced [Tsugita et al. (1979) in Cytochrome oxidase (King, T. E. et al., eds) pp. 67-77, Elsevier, New York], consists of 262 amino acids and has the molecular mass of 29,908 Da including the heme. The sequence contains an N-terminal hydrophilic part of 211 residues, which carries the heme, a hydrophobic stretch of 15 residues, which is assumed to anchor the protein to the membrane, and a C-terminal hydrophilic part of 36 residues. The N-terminal presequence of 70 amino acids contains 9 positive charges but only 1 negative charge and is characterized by a stretch of 20 uncharged residues.
NADH: ubiquinone reductase (electron transfer complex I) has been isolated from Neurospora crassa mitochondria as a monodisperse protein-phospholipid-Triton X-100 complex (1:0.04:0.15, by weight). The enzyme is in the monomeric state, has a protein molecular weight of 610,000 and consists of about 25 different subunits. Membrane crystals of the enzyme complex have been prepared by adding mixed phospholipid-Triton X-100 micelles and then removing the Triton by dialysis. Diffraction patterns of the negatively stained membrane crystals extend to about 3.9 nm, with a unit cell size of 19 nm X 38 nm and gamma = 90 degrees. The two-sided plane group packing corresponding to pgg is p22(1)2(1). By combining four sets of tilted views, a low-resolution three-dimensional structure of the protein has been calculated. The structure shows that NADH: ubiquinone reductase extends 15 nm across the membrane, projecting 9 nm from one membrane side and 1 nm from the opposite side. Only about one-third of the total protein mass is located in the membrane. The structure of NADH: ubiquinone reductase is compared with that of ubiquinol: cytochrome c reductase determined by electron microscopy of membrane crystals.
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We studied 22 twin pairs in which one or both twins had dementia of the Alzheimer type (DAT). In four twins, diagnosis was confirmed by autopsy. Seven monozygotic (MZ) pairs were concordant for DAT; 10 MZ pairs were discordant. Two dizygotic (DZ) pairs were concordant for DAT, and 3 DZ pairs were discordant. The current concordance rate was 41% for MZ twins and 40% for DZ twins. The study supports the belief that, etiologically, DAT cannot be entirely accounted for by a single autosomal dominant gene. The data also suggest that in certain genetic circumstances, disease expression may be delayed in females.