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Abstract
Congenital malformations are many times more common in individuals with Down syndrome (DS) than in the general population. The scope of these defects is as broad in DS as it is in the general population. A positive correlation exists between the prevalence of these defects in both groups, but the incidence of each is many times greater in DS. Two examples, Brushfield spots and anorectal abnormalities are noted in which racial/ethnic prevalence differences exist. The incidence of each condition in the subpopulation with DS is proportional to but many times greater than the incidence of that condition in the general population from which the subpopulation with DS was derived. Findings presented in this review support the notion that the autosomal trisomic state amplifies expression of exposure to teratogens.
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Lanthanide-induced shifts in proton nuclear magnetic resonance spectra. III. Lanthanide shift reagent-substrate equilibriums. J Am Chem Soc 2002. [DOI: 10.1021/ja00778a040] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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4
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Nuclear magnetic resonance studies of enol-enol and keto-enol equilibria in substituted benzoylacetones. J Org Chem 2002. [DOI: 10.1021/jo01262a004] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Structure elucidation with lanthanide-induced shifts. 10. Generation of atomic coordinates: empirical force field calculations vs. other methods. J Org Chem 2002. [DOI: 10.1021/jo00325a018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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The Pyrolysis of 2-Phenyltetrahydro-1,2-oxazines as a Simple Preparative Entry to Cyclobutanes. J Am Chem Soc 2002. [DOI: 10.1021/ja00900a049] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Lanthanide-induced shifts in proton nuclear magnetic resonance spectra. VI. 3-(.alpha.-Naphthyl)-5,5-dimethylcyclohexanone and derived alcohols. Synthesis and stereochemical studies by means of lanthanide-induced proton nuclear magnetic resonance shifts. J Am Chem Soc 2002. [DOI: 10.1021/ja00783a035] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Lanthanide-induced shifts in proton nuclear magnetic resonance spectra. II. Lanthanide-induced changes in proton spin-spin coupling constants. J Am Chem Soc 2002. [DOI: 10.1021/ja00767a079] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Lanthanide-induced shifts in proton nuclear magnetic resonance spectra. XI. Equilibrium constants and bound shifts for cyclohexanones and cyclohexanols. J Am Chem Soc 2002. [DOI: 10.1021/ja00836a014] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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12
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Direct evidence from carbon-13 nuclear magnetic resonance for intramolecular scrambling of carbonyl groups in a metal atom cluster carbonyl, tetrarhodium dodecacarbonyl. J Am Chem Soc 2002. [DOI: 10.1021/ja00772a044] [Citation(s) in RCA: 155] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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13
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Lanthanide-induced shifts in proton nuclear magnetic resonance spectra. I. Europium-induced shifts to higher fields. J Am Chem Soc 2002. [DOI: 10.1021/ja00742a031] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Excellent therapeutic efficacy and minimal late neurotoxicity in children treated with 18 grays of cranial radiation therapy for high-risk acute lymphoblastic leukemia: a 7-year follow-up study of the Dana-Farber Cancer Institute Consortium Protocol 87-01. Cancer 2001; 92:15-22. [PMID: 11443604 DOI: 10.1002/1097-0142(20010701)92:1<15::aid-cncr1286>3.0.co;2-w] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND In the current study, the authors evaluated late neuropsychologic effects 7 years after diagnosis and the long-term survival in a cohort of patients treated for high-risk childhood acute lymphoblastic leukemia (ALL) with cranial radiation therapy. Efficacy and toxicity were evaluated in relation to patient age at diagnosis (age < or > or = 36 months). METHODS Two hundred and one patients treated for high-risk ALL on the Dana-Farber Cancer Institute Consortium Protocol 87-01 were included, 147 of whom were in continuous complete disease remission and were eligible for cognitive testing. Sixty-one patients consented to undergo testing. All patients received 18 grays (Gy) of cranial radiation as a component of central nervous system treatment. RESULTS For all 201 patients, the 5-year overall survival (% +/- the standard error) was 82% +/- 2 and the 5-year event-free survival (% +/- the standard error) was 75% +/- 3. Only two patients developed a central nervous system recurrence. Intelligence quotient (IQ) and memory were at the expected mean for age, but performance on a complex figure drawing task was found to be reduced. Children who were age < 36 months at the time of diagnosis were found to have an IQ in the average range, but showed verbal deficits. CONCLUSIONS The results of the current study demonstrate excellent efficacy of therapy and relatively limited late neurotoxicity on a childhood ALL therapy protocol in which all evaluated patients had received 18 Gy of cranial radiation. Efficacious therapy that includes cranial radiation does not appear to necessarily incur a heightened risk for significant cognitive impairment.
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Developmental instability of the cerebellum and its relevance to Down syndrome. JOURNAL OF NEURAL TRANSMISSION. SUPPLEMENTUM 2001:11-34. [PMID: 11771737 DOI: 10.1007/978-3-7091-6262-0_2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/17/2023]
Abstract
It has been recognized for many years that cerebellar abnormalities are frequently observed in association with Down syndrome (DS). An important question to be asked about these and other findings in DS is whether their occurrence (i) is attributable to specific loci on the triplicated chromosome or chromosomal segment or (ii) derives from exaggerated responses secondary to the genetic imbalance resulting from trisomy (Ts). Recently, similar cerebellar alterations were observed in subjects with DS and in Ts65Dn mice (Baxter et al., 2000), mice segmentally trisomic for a portion of chromosome 16, which is homologous for loci on the long arm of human chromosome 21. It was concluded by these authors that the occurrence of similar cerebellar changes in DS and in the DS mouse model resulted from triplication of these homologous loci in the two trisomic organisms, i.e. cerebellar development is affected similarly by homologous loci in each species. They wrote that their study of Ts65Dn mice "correctly predicts an analagous pathology in humans". . . and that. . . "The candidate region of genes on chromosome 21 affecting cerebellar development in DS is therefore delimited to the subset of genes whose orthologs are at dosage imbalance in Ts65Dn mice, providing the first localization of genes affecting a neuroanatomical phenotype in DS." Findings described in this review suggest otherwise--that cerebellar findings in DS and in the Ts65Dn mouse are a result of exaggerated vulnerability in general of the cerebellum to disturbing events and that liability to expression of response(s) is exacerbated by trisomy. This conclusion is based on the following: (i) the cerebellum has an extended postnatal development; (ii) numerous genetic, environmental, epigenetic and metabolic conditions express cerebellar changes similar to those observed in Down syndrome; (iii) most if not all chromosomal imbalance syndromes express similar cerebellar abnormalities; (iv) the cerebellum is particularly sensitive to diverse toxic agents which may act prenatally, postnatally and/or in the mature organism; and (v) cerebellar abnormalities similar to those found in Ts65Dn mice have been described in Ts19 mice which have no segments homologous to any segment of human chromosome 21. An unavoidable conclusion from the review is that triplication of specific loci on 21q is an unlikely explanation for the cerebellar findings in DS. A simple positive control, in which the effect of triplication of loci other than those in question on a specific phenotype, should be used in experiments comparing human and experimental trisomies. As pointed out many years ago by Lorke and his coworkers (Lorke et al., 1989; Lorke, 1994; Lorke and Albrecht, 1994) similar phenotypic findings in the presence of different trisomies in the same species would suggest that the trisomic state itself rather than the gene content of a particular trisomy is responsible for the genesis of traits at issue.
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Abstract
Since the early 1970's numerous attempts have been made to learn whether specific segments of chromosome 21, when triplicated, are responsible for the clinical condition Down syndrome (DS). Studies were reported in which positive or negative clinical diagnoses of DS were made in the presence of partial trisomy of one or another segment of the chromosome. The distal half of the long arm of 21 (21q22) possesses most of the gene transcribing sites of the chromosome. It was this region that was thought to contain loci essential to production of the clinical syndrome. Subsequent studies identified subregions of this band as "minimal" or "critical" sites necessary and sufficient to produce the clinical condition. A major problem with these assignments was that different investigators defined different critical/minimal regions. In 1994 evidence was presented in which regions of most of the long arm of chromosome 21 were said to contribute to the DS phenotype. Soon after, a report described a child with DS and partial tetrasomy of the short arm and proximal long arm of 21, segments clearly distinct from the previously identified critical areas. Thus the clinical diagnosis of DS can be made in the presence of partial aneuploidy of nearly all segments of chromosome 21. It must be concluded that no evidence exists that individual loci on 21 are singularly responsible for specific phenotypic abnormalities in DS. Without exception, each of the clinical findings associated with DS is a multifactorial trait. The analysis of each trait in DS should thus be similar to analyses of the same traits in the general population with a focus on the way aneuploidy affects expression of multifactorial characteristics.
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Abstract
A cross-sectional study of prevalence of temporomandibular joint (TMJ) internal derangements, muscle disorders, and associated TM signs and symptoms was completed on 269 female nursing students. The prevalence of specific stages of internal derangements of the TMJ and muscle disorders was estimated, using established diagnostic criteria. The levels of dysfunction and symptomatology associated with each diagnosis were estimated with previously established indexes. When subjects with symptoms were asked if they had previous treatment for a TMJ problem, 6.7% responded positively. When subjects with symptoms who had not had treatment were asked why they had not sought treatment, most responded that it was not a problem or they could live with the symptoms. Thus, most subjects with clinically detectable dysfunction are functioning adequately without significant symptoms and do not need treatment.
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Bioregulatory mechanisms at the level of cell organelle interactions: microspectrofluorometric in situ studies. J Biotechnol 1990; 13:1-27. [PMID: 1366580 DOI: 10.1016/0168-1656(90)90128-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The spatiotemporal analysis of bioregulatory mechanisms at the level of intracellular multienzyme complexes and organelle interactions is made possible by the availability of endogenous and exogenous fluorescence probes, the development of microspectrofluorometers allowing one- and two-dimensional scans of intracellular fluorescence reactions, and the use of micromanipulatory techniques enabling the rapid alteration of metabolic states. Absorbed photons are not only a tool for quantitative evaluation of metabolic processes, they can also trigger alterations of cell membranes and functions as mediated by photosensitizer drugs. In the hierarchy of intracellular organization different levels of complexity are accessible to study, such as the regulation of multienzyme complexes and the interaction of organelle complexes. Typical applications of these methods are the investigation of drug effects (e.g., on melanoma cells), metabolic and structural alterations (e.g., in cystic fibrosis and Gaucher fibroblasts), organelle interactions in cells treated with toxic agents. The implications are relevant to biotechnology for better control of metabolite production and processing, design and testing of new drugs, understanding of drug resistance and better targeting of drugs or probes to selected intracellular sites. In addition, such in vitro methods can contribute to the provision of an alternative to "whole animal experiments" as already achieved in human and mouse fibroblasts, hepatocytes, hepatoma, Swiss 3T3 cells and other cells in culture, especially with regards to an analysis of the action of xenobiotics and drugs in cell physiology and pathology, fluorescence recovery after photobleaching, study of cytoskeleton dynamics and multiparameter probing of organelle activity during in vitro wound repair.
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The pathogenesis of aneuploid phenotypes: the fallacy of explanatory reductionism. AMERICAN JOURNAL OF MEDICAL GENETICS 1989; 33:146-51. [PMID: 2526583 DOI: 10.1002/ajmg.1320330124] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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23
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Abstract
Cystic fibrosis (CF) remains a major problem in human genetics and cell pathophysiology. It is a single gene trait caused by a mutation on the long arm of chromosome 7. Among its expressions are abnormal regulation of chloride channels and/or microobstructions in exocrine tissues. Here, evidence is presented that mitochondria are dysfunctional in CF: the major site of increased intracellular Ca in CF is mitochondrial, cells from subjects with CF consume more oxygen than normal, respond differentially to inhibitors of mitochondrial function, express increased electron transport activity and altered kinetics of complex I (NADH dehydrogenase) of the mitochondrial electron transport system. Patients with CF express increased total and resting energy expenditure. Some of these differences from normal occur also in asymptomatic carriers of the CF gene.
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Abstract
Increased intracellular calcium (Ca) has been reported in several cell types in cystic fibrosis (CF). Because CF is an autosomal recessive trait examination of asymptomatic obligate carriers (HZ) of the gene is a powerful way to determine the relevance of this observation to the abnormal gene product. We report here that Ca as determined by atomic absorption spectrophotometry in cultured skin fibroblasts and circulating lymphocytes is greater in HZ than in control cells. Since an intracellular Ca increase is expressed in HZ the Ca differences in CF likely reflect action of the gene product responsible for CF and not some secondary or tertiary effect of the disease.
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Regeneration and attachment of the periodontal ligament. NORTHWEST DENTISTRY 1984; 63:22-24. [PMID: 6382158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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Competitive inhibition of human mitochondrial NADH dehydrogenase by Cibacron Blue F3GA. ENZYME 1984; 32:188-92. [PMID: 6510405 DOI: 10.1159/000469474] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Cibacron Blue F3GA, the chromophore of blue dextran, was tested at 4-16 mumol/l for possible inhibition of NADH dehydrogenase activity when added to mitochondrial preparations from cultured human skin fibroblasts. The free dye was shown to be a competitive inhibitor for NADH in the oxidation of NADH catalyzed by the mitochondrial enzyme. The Ki (5.8 mumol/l) for Cibacron Blue F3GA was considerably lower than the Michaelis constant (Km) found for NADH substrate (13.2-16.1 mumol/l), indicating a strong binding of the dye to the substrate-binding site of the enzyme. This is the first report of the competitive inhibition by Cibacron Blue F3GA of mitochondrial NADH in any species.
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The major histocompatibility complex of man: implications for transplantation and disease. NORTHWEST DENTISTRY 1983; 62:12-6. [PMID: 6576324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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[Development of the eye. A study using electron scanning microscopy]. CESKOSLOVENSKA OFTALMOLOGIE 1983; 39:149-53. [PMID: 6872037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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[Morphogenesis of the abdominal end of the paramesonephric ducts (study using the scanning electron microscope)]. CESKOSLOVENSKA GYNEKOLOGIE 1983; 48:184-6. [PMID: 6616643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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31
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[Anatomy of the embryonic umbilicus (a study using scanning electron microscopy)]. CESKOSLOVENSKA GYNEKOLOGIE 1983; 48:107-9. [PMID: 6850878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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32
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[Anatomy of the chorion]. CESKOSLOVENSKA GYNEKOLOGIE 1983; 48:15-7. [PMID: 6831572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Abstract
A major question in human genetics concerns the relationship between the extra chromosome material in the Down syndrome (DS) and its effects. It is suggested here that a generalized disruption of evolved genetic balance in cells of affected individuals leads to decreased developmental and physiological buffering against genetic and environmental forces. Examples of consequences in DS of this model of disruption of homeostasis are presented: i) increased variance for metric traits, ii) amplified instability of developmental pathways, iii) reduced precision of physiological homeostatic controls, and iv) generalized increased morbidity. Evolution has selected for interacting systems. When this evolved balance is disrupted, as in autosomal aneuploidy, the organism is generally disrupted. The model emphasizes the role of environment in producing much of the DS phenotype. Traits less buffered than others in the general population are the ones most disturbed in DS and account for much of the DS phenotype.
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Mitochondrial NADH dehydrogenase in cystic fibrosis: enzyme kinetics in cultured fibroblasts. Am J Hum Genet 1982; 34:846-52. [PMID: 7180843 PMCID: PMC1685704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Differences among cystic fibrosis (CF) genotypes (CF, obligate carriers for CF [HZ], and controls) in mitochondrial calcium pool size, oxygen (O2) consumption, and rotenone inhibition of O2 consumption led to examination of mitochondrial NADH dehydrogenase (NADH: [acceptor] oxidoreductase, E.C. 1.6.99.3). pH optima of mitochondrial NADH dehydrogenase were different in enzyme derived from whole cell homogenates of cultured skin fibroblasts of subjects with CF, HZ, and controls. We describe here apparent binding of substrate to the enzyme (Km [NADH]) in cell fractions. Km (NADH) for CF ranged from 10.9 to 16.1 micro M (no. = 7); for HZ from 20.9 to 26.3 microM (no. = 5). With three exceptions, Km for controls (no. = 12) ranged from 31.8 to 42.8 microM. Km of the three exceptional controls were 21.5, 23.7, and 22.4 microM (the latter two are identical twins). pH optima of enzyme from these three strains were no different from that of known HZ. The correlation between two kinetic parameters of an enzyme and the three CF genotypes suggests an association between the CF gene and mitochondrial NADH dehydrogenase.
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Abstract
Intracellular calcium increases significantly as human fibroblasts age in culture. The calcium increase occurs 5 to 6 weeks (passages) earlier and is significantly greater in fibroblasts from subjects with cystic fibrosis in comparison with cells from control subjects. Intracellular calcium, which is thought to be a pathogenetic factor in cystic fibrosis, may also be a meaningful marker in cell aging.
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Mediation of pain. NORTHWEST DENTISTRY 1982; 61:23-6. [PMID: 6125930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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37
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Abstract
Calcium uptake by mitochondria isolated from skin fibroblasts of patients with cystic fibrosis and controls was studied in the presence and absence of inhibitors. Since mitochondrial calcium accumulation may be supported by ATP hydrolysis or respiration, inhibitors of each were used to characterize the basis of previously described alterations in calcium uptake by mitochondria from patients with cystic fibrosis. Calcium uptake measurements under the influence of oligomycin and antimycin A suggest that the increased calcium uptake by mitochondria from patients with cystic fibrosis is related to altered respiratory system activity. Binding constants of calcium to the carrier system in mitochondria were not different between genotypes.
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One to one correlation of histological and histochemical light microscopy with scanning electron microscopy. SCANNING ELECTRON MICROSCOPY 1981:63-72. [PMID: 6172846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Several histological stains were applied to specimens after scanning electron microscopic (SEM) processing. Histochemical stains were applied before SEM fixation. After staining, the specimens were processed and dried by SEM techniques. The specimens were taped to a microslide, specimen side up, scribed and covered with immersion oil. After light micrography (LM), the oil was removed and the specimens mounted and gold coated. The same cells were then relocated and photographed by SEM. Periodic acid Schiff was not usable as a specific tissue aldehyde stain, but did prove to be a useful counterstain for dehydrogenase stained specimens. Colloidal iron, as seen by SEM, resulted in a non-specific granular deposit over the specimen and the substrate. All the other histological stains examined--alcian blue, Grams, Feulgen and toluidine blue--were specific and did not change the specimen ultrastructure. The histochemical stains--acid and alkaline phosphatase and three dehydrogenases--were also specific. There were some minor ultrastructural changes with the AcPase and AlPase stains. However, the tissue surface was not significantly distorted. These and other techniques should prove to be a useful adjunct to SEM studies.
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Changing views about temporomandibular pain-dysfunction. NORTHWEST DENTISTRY 1981; 60:5-9. [PMID: 7012787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Abstract
The incorporation of radioactively labeled leucine into TCA-precipitable proteins by submandibular gland tissue slices from control, alloxan diabetic, and insulin supplemented diabetic rats was measured in vitro. Incorporation decreased in alloxan diabetes and could be restored to control levels within three hours after insulin administration. The effects of alloxan diabetes and insulin on 3H-leucine incorporation paralleled their effects on a secretory enzyme, peroxidase. Insulin in vitro stimulated the incorporation of 3H-leucine within 15 minutes of addition to the incubation medium. Further, the response to insulin was found to be dose-related. The conclusion drawn from these results is that insulin has a rapid, direct effect on the rate of protein synthesis in the rat submandibular gland.
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Dental implants--progress and prospects. NORTHWEST DENTISTRY 1979; 58:184-7. [PMID: 297875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Differential incorporation of 3H-thymidine into DNA in cultured skin fibroblasts derived from patients with cystic fibrosis and controls. Life Sci 1979; 24:2483-9. [PMID: 481117 DOI: 10.1016/0024-3205(79)90459-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Abstract
The importance of intracellular calcium (Ca) in secretion and transmembrane ion movement led us to study Ca in cells from patients with cystic fibrosis (CF) which is a lethal genetic exocrinopathy. Skin fibroblasts from patients with CF, obligate heterozygotes (HZ), and age- and sex-matched controls (C) were used in matched pair experiments measuring 45Ca exchange into and efflux from the cells over time. CF cell lines and HZ cell lines exhibit increased 45Ca exchange when compared with their respective controls (P less than 0.005). The magnitude of this difference (approximately 30%) is not reduced when cells are washed with lanthanum chloride after the exchange period. This difference is likely attributable to an altered capacity of one or more of the intracellular Ca sequestering organelles. Further evidence for this explanation was seen in 45Ca efflux experiments in which CF cells retained a higher percent of their initial 0-time 45Ca than did C cells late in the efflux period (P less than 0.05). The finding of an altered Ca pool size in both CF and particularly HZ cells suggests that altered Ca metabolism is related to the basic gene defect in CF.
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Abstract
We have shown that skin fibroblast from patients with cystic fibrosis (CF) and from carriers for CF [heterozygotes (HZ)] consume more O2 than do their controls. When the mitochondrial electron transport inhibitor rotenone was added to the cells, the relative inhibition of O2 consumption was CF greater than HZ greater than controls (P less than 0.005 in both comparisons). Because rotenone specifically inhibits NADH dehydrogenase, [NADH: (acceptor) oxidoreductase, EC 1.6.99.3], which is the enzyme of energy-conserving site 1 of the mitochondrial electron transport system, activity and kinetics of this enzyme system were studied in fibroblast homogenates. NADH dehydrogenase activity was equal in cells from the three genotypes. At pH 8.0, affinity of the enzyme for its substrate was CF greater than HZ = controls; at pH 8.6, affinity was CF greater than HZ = controls (P less than 0.005 for the differences). pH optima for the genotypes were without exception 8.6 (CF), 8.3 (HZ), and 8.0 (control). HZ and control lines were distinguished unequivocally in a blind test on the basis of differences in pH optima. Purified mitochondrial preparations revealed pH optima identical to those found in whole cell homogenates. These data suggest that the mutant gene responsible for CF is expressed in the complex mitochondrial NADH dehydrogenase system.
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Abstract
Cultured skin fibroblasts from subjects with cystic fibrosis exhibited normal population doubling times in early passages. After about 13 cumulative population doublings, cystic fibrosis lines doubled more slowly than controls and ceased doubling after about 19 weekly passages. Control lines continued doubling for 27 passages. The premature senescence noted in cells from subjects with cystic fibrosis reconciles controversial observations of cell doubling reported in the literature. Data presented here demonstrate that experiments with cystic fibrosis cells in late passage may generate misleading results since differences from control lines may be ascribed to generalized senile changes rather than to specific results of the cystic fibrosis genotype.
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Abstract
Human metaphase chromosomes were processed with a 3% glutaraldehydetannic acid technique and examined in a scanning electron microscope at 20 kV either without added metal coating or with 2 nm of sputtered gold coating. Several substrates--aluminum mnium foil, silver mirror deposit and sputtered gold-provided good conductive backgrounds for chromosomal spreads. Silver mirror deposit was the best conductive substrate tested. This method should prove to be a useful tool for monitoring the three-dimensional morphology of mitotic chromosomes with the possibility of studying various banding techniques, chromosomal uncoiling and secondary constrictions currently being examined in chromosomal studies.
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The effect of alloxan diabetes and insulin in vivo on peroxidase activity in the rat submandibular gland. Arch Oral Biol 1979; 24:343-5. [PMID: 293146 DOI: 10.1016/0003-9969(79)90100-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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50
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Diseases of periodontal tissues. NORTHWEST DENTISTRY 1978; 57:233-5. [PMID: 290966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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