High androgen levels in chronic fatigue patients.
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Androgens↗
Biomedical subjects
M Goldberg
Publications and source records attributed to M Goldberg.
Xenopus lamin B3 has a direct role in the assembly of a replication competent nucleus: evidence from cell-free egg extracts.
Xenopus egg extracts which assemble replication competent nuclei in vitro were depleted of lamin B3 using monoclonal antibody L6 5D5 linked to paramagnetic beads. After depletion, the extracts were still capable of assembling nuclei around demembranated sperm heads. Using field emission in lens scanning electron microscopy (FEISEM) we show that most nuclei assembled in lamin B3-depleted extracts have continuous nuclear envelopes and well formed nuclear pores. However, several consistent differences were observed. Most nuclei were small and only attained diameters which were half the size of controls. In a small number of nuclei, nuclear pore baskets, normally present on the inner aspect of the nuclear envelope, appeared on its outer surface. Finally, the assembly of nuclear pores was slower in lamin B3-depleted extracts, indicating a slower overall rate of nuclear envelope assembly. The results of FEISEM were confirmed using conventional TEM thin sections, where again the majority of nuclei assembled in lamin B3-depleted extracts had well formed double unit membranes containing a high density of nuclear pores. Since nuclear envelope assembly was mostly normal but slow in these nuclei, the lamin content of 'depleted' extracts was investigated. While lamin B3 was recovered efficiently from cytosolic and membrane fractions by our procedure, a second minor lamin isoform, which has characteristics similar to those of the somatic lamin B2, remained in the extract. Thus it is likely that this lamin is necessary for nuclear envelope assembly. However, while lamin B2 did not co-precipitate with lamin B3 during immunodepletion experiments, several protein species did specifically associate with lamin B3 on paramagnetic immunobeads. The major protein species associated with lamin B3 migrated with molecular masses of 102 kDa and 57 kDa, respectively, on one-dimensional polyacrylamide gels. On two-dimensional O'Farrell gels the mobility of the 102 kDa protein was identical to the mobility of a major nuclear matrix protein, indicating a specific association between lamin B3 and other nuclear matrix proteins. Nuclei assembled in lamin B3-depleted extracts did not assemble a lamina, judged by indirect immunofluorescence, and failed to initiate semi-conservative DNA replication. However, by reinoculating depleted extracts with purified lamin B3, nuclear lamina assembly and DNA replication could both be rescued. Thus it seems likely that the inability of lamin-depleted extracts to assemble a replication competent nucleus is a direct consequence of a failure to assemble a lamina.
Animals↗
Factitious injury of the oral mucosa: a case series.
Gingival and oral mucosal tissues can be the site of a number of mucocutaneous and ulcerative conditions. Generally, these are not difficult to identify on the basis of clinical characteristics, and diagnosis can be aided by the use of routine histopathological and immunopathological techniques as well as other laboratory investigations. Self-induced or factitious injury (FI) of the oral mucosal tissues may present a confusing clinical picture, and be diagnosed erroneously as a mucocutaneous disorder in spite of the absence of appropriate pathological and immunopathological findings, or a failure to respond to routine treatment. A case series is presented here outlining 4 cases of FI which presented initially as mucocutaneous disease. These cases were investigated to rule out systemic or local causes, in order to establish a diagnosis of FI. Treatment of these conditions was facilitated with placebo or sham procedures which were designed primarily to cover the lesions. In most cases, the self injurious behavior could be linked to secondary gain.
Adult↗
Tissue response to particulate polymethylmethacrylate in mice with various immune deficiencies.
We examined the tissue response to subcutaneous injections of particulate polymethylmethacrylate powder in fully immunocompetent C3Hf/Sed mice as well as three strains of mice with different levels of lymphocyte dysfunction. Five weeks after the injection, we found clearly demarcated granulomas. Histological and immunohistochemical studies showed that these granulomas were similar among all strains, with either paucity or absence of lymphoid cells. In situ hybridization with use of complementary RNA probes indicated that macrophages were synthesizing interleukin-1 beta messenger RNA (mRNA), a marker of macrophage activation, and a cytokine implicated in pathological bone resorption. We concluded that, in mice, there is a lymphocyte-independent pathway of macrophage activation in response to particulate polymethylmethacrylate. This suggests that the foreign-body response to particulate orthopaedic biomaterials is macrophage-initiated and maintained and that lymphocytes are not essential to this response, although they may modulate it.
Analysis of Variance↗
Accelerated eruption of rat lower incisor. Relationship between impeded and unimpeded eruption rates, rate of attrition, tooth length, and production of dentin and enamel.
The present investigation studies the effects of persistently cutting one lower rat incisor out of occlusion. Within four days, the rate of eruption of the cut (unimpeded) incisor increased to 216% and that of the uncut (impeded) contralateral to 136% of the baseline rate. While the former remained high, the latter decreased gradually to about 90% within three weeks. The rate of attrition of the impeded incisor increased to 233% of the baseline rate within two days, then fell abruptly, and remained at a slightly lower level than the rate of eruption. Accordingly, the length of the erupted part of the impeded incisor decreased initially, but increased gradually after about four days. Measurements made on SEM micrographs of the series of transverse tooth segments obtained when cutting the incisor out of occlusion, showed that growth-related increase in mesiodistal tooth width was arrested from the 10th segment, dentin thickness decreased gradually to about 50% in the 12th segment, and enamel thickness, after an initial increase, decreased to about 80% in the 11th segment. The present study provides experimental evidence that accelerated eruption affects morphogenesis and histogenesis of the rat lower incisor. An impeded incisor, especially the contralateral, may not serve as an ideal control.
Animals↗
Effects of thyro-parathyroidectomy and parathyroidectomy upon dentinogenesis: Part I: Light microscopy.
In order to determine the differential effects of the thyroid hormones and the parathyroid hormone upon dentinogenesis in the rat incisor one control group (C) and four groups of surgically treated rats were studied: parathyroid autotransplanted (PTT), thyroidectomized (TX), parathyroidectomized (PTX), and thyro-parathyroidectomized group. One month after surgery the incisors were dissected and the tissues were prepared for light microscopy and morphometric measurements. This study revealed modifications in the TPTX rats as well as in the PTX rats: an enlargement of the predentin, alterations in the predentin appearance and the presence of mineralization defects. These results confirm that the effects observed are probably due to a PTH deficiency and/or hypocalcemia and suggest that their occurrence is associated with a determined stage of dentinogenesis in the rat.
Animals↗
Effects of thyro-parathyroidectomy and parathyroidectomy upon dentinogenesis: Part II: Electron microscopy.
An ultrastructural study was carried out in order to better characterize the findings observed in the first part of our study. The materials and methods are the same as those used in the preceding paper. This study reveals the occurrence of structures which display a symmetrical cross-banded pattern within the predentin and dentin of thyro-parathyroidectomized (TPTX) and parathyroidectomized (PTX) rats. A difference in the distribution of the symmetrical banded structures as dentinogenesis advances, as well as differences in the amount of the symmetrical banded structures between TPTX and PTX rats were observed. The symmetrical banded structures correspond with the so-called symmetrical SLS previously described in the incisor of normal and pathologic rats. The occurrence of these structures at a given stage of the incisor development suggests that the odontoblast is sensitive to the parathyroid hormone deficiency and/or hypocalcemia in a precise stage of its maturation.
Animals↗
Lipids in predentine and dentine.
Using two histochemical methods, malachite green-aldehyde and iodoplatinate, phospholipids were visualized in the predentine of rat incisors in the spaces located between collagen fibers and in dentine as needle-like structures located along individual or groups of mineralizing collagen fibers. The same staining pattern was seen with phospholipase A2-gold. Autoradiographic investigation using 3H choline as labelled precursor, visualized the incorporation of membrane-associated and extracellular choline-containing phosphatidyl choline and sphingomyelin. The cell and membrane-associated labelling decreased gradually between 24 and 4 days, whereas incorporation of the labelled precursor as stable extracellular matrix component was seen in dentine. In addition to these investigations, pharmacologically induced (suramine) and genetically (Krabbe's disease) lysosomal storage pathology was investigated. Defects due to lipid metabolism alterations were seen in predentine and/or in dentine. The major differences visualized here between the non-mineralized and mineralized compartments and interactions between phospholipids and proteoglycans, support the view that phospholipids as matrix components play an important role in the mechanisms of dentine formation and mineralization.
Animals↗
Implementation of once or twice daily dosing in a long-term care facility.
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Aged↗
[Potential role of environmental and domestic exposure to tremolite in pleural cancer in New Caledonia].
A previous study of respiratory cancers in New Caledonia (1978-1987) showed an excess risk of pleural cancer in this South Pacific French Territory, leading to the identification of an environmental pollution. In some villages, the residents use for their houses a whitewash made from a rock derived from local outcroppings. Analysis of samples of rock and whitewash showed that they consisted of tremolite asbestos. High levels of tremolite were detected in airborne samples collected in these villages and in biological specimens of patients with pulmonary cancer or mesothelioma; the concentrations of fibers are up to 78,000 fibers per litre of air and 44 millions of fibers per gramme of dry tissue. Besides the whitewash, the environmental exposure to tremolite fibers could also be associated with certain occupations. A case control study under process will allow the estimation of respiratory cancer risks associated with the exposure to tremolite.
Air Pollutants↗
Dental mineralization.
Extracellular matrix components and cell-derived microstructures are implicated in mineralization processes which occur in dental tissues. The respective role(s) of collagenic and non-collagenic matrix components are reviewed: phosphorylated and non-phosphorylated proteins, proteoglycans and phosphpholipids. Space-filling amphiphilic molecules seem to play an important role in the preorganization and oriented deposition of calcium phosphate on structures serving more or less as passive support in dentine as well as in enamel.
Amelogenesis↗
Poly-L-lysine-gold complexes used at different pH are probes for differential detection of glycosaminoglycans and phosphoproteins in the predentine and dentine of rat incisor.
At neutral pH, poly-L-lysine-gold complexes labelled the predentine extensively, whereas in dentine the number of gold complexes was reduced by half. Hyaluronidase pretreatment of the section at pH 6.8, prior to labelling, suppressed most of the staining in predentine and did not affect dentine. In contrast, alkaline phosphatase pretreatment at pH 9 enhanced the gold complex labelling in predentine and removed most of the labelling in dentine. This proves that at pH 7.2, the polyanions which are stained include a heterogeneous population of glycosaminoglycans, located in predentine, and phosphoproteins, visualized in dentine. At acidic pH levels (2.9 and 1.1), the number of scored gold complexes decreased, but the ratio between predentine and dentine labelling remained constant. Hyaluronidase pretreatment removed or firmly reduced the gold complex labelling both in predentine and dentine, whereas alkaline phosphatase pretreatment of the sections at pH 9 prior to labelling did not induce any change. This argues in favour of an increased specificity of polylysine-gold complex staining for glycosaminoglycans, stained at low pH in both predentine and dentine. Differential staining of glycosaminoglycans and phosphoproteins according to the pH provides a useful tool for studying the role played respectively by the two matrix components in dentine mineralization.
Animals↗
Topical and subcutaneous alpha-interferon fails to suppress corneal neovascularization.
Corneal neovascularization is a potentially blinding complication of a variety of corneal disorders. alpha-Interferon has been shown to inhibit endothelial cell migration and proliferation. It has been used successfully in the treatment of pediatric pulmonary hemangioma and hairy cell leukemia. This study was undertaken to evaluate the effect of topical and subcutaneous (s.c.) alpha-interferon on corneal neovascularization. Corneal neovascularization was induced in 40 male New Zealand white rabbits by placing silk sutures (7.0) bilaterally in each rabbit eye at the 3 and 9 o'clock positions of the cornea, 3 mm from the limbus. Animals were randomized into two main treatment groups for topical (group 1) and s.c. (group 2) administration of interferon. Group 1 (n = 24) was then randomized into four subgroups and treated daily with topical doses of (a) rabbit specific alpha-interferon; (b) alpha-interferon plus 1% prednisolone acetate; (c) 1% prednisolone acetate; and (d) buffered phosphate control. Group 2 (n = 16) was randomized into two subgroups that received s.c. injections every other day of (a) alpha-interferon and (b) phosphate buffer. Rate of corneal neovascularization was documented photographically, with the end-point being the arrival of vessels at the suture for each group. The results of this study indicated that at the concentration and dosing regimens we used, neither topical nor s.c. alpha-interferon inhibits the rate of corneal vascular growth significantly when compared with our phosphate buffered solution control group (p = 0.88 and p = 0.84, respectively). Prednisolone acetate appeared to be the most effective in inhibiting corneal neovascularization (p = 0.003).(ABSTRACT TRUNCATED AT 250 WORDS)
Administration, Topical↗
Increased renal medullary echogenicity in neonates.
The prevalence of increased renal medullary echogenicity in healthy neonates was looked for. A group of 178 neonates underwent renal ultrasound on the first and second days of life. On the first day of life 58% had hyperechoic material in their renal collecting system, whereas on the second day only 33% were found to have ultrasonographically demonstrable increased echogenicity in their kidneys. Urinary protein concentrations in infants with increased renal echogenicity were significantly higher than in those without increased renal echogenicity.
Adjuvants, Immunologic↗
Association between exposure to pulsed electromagnetic fields and cancer in electric utility workers in Quebec, Canada, and France.
The authors report the association between exposure to pulsed electromagnetic fields (PEMFs) and cancer in a nested case-control study of electric utility workers in Quebec, Canada (follow-up, 1970-1988), and France (follow-up, 1978-1989), among whom 2,679 cases of cancer were identified. Exposures were assessed through a job-exposure matrix based on about 1,000 person-weeks of measurements from exposure meters worn by workers. Exposures were considerably higher in Quebec than in France. No association was found between PEMFs and cancers previously suspected of association with magnetic fields (leukemia, other hematopoietic cancers, brain cancer, or melanoma). However, there was a clear association between cumulative exposure to PEMFs and lung cancer, with odds ratios rising to 3.11 (95% confidence interval (CI) 1.60-6.04) in the highest exposure group (84 cases). This association with largely confined to Quebec, where there was a monotonic exposure-response relation with an odds ratio of 6.67 (95% CI 2.68-16.57) in the highest exposure group (32 cases). The association is substantial and was not explained by smoking or other occupational exposures. However, several factors limit the strength of the evidence for a causal relation: lack of precision in what the meters measured; little previous evidence for this association; and no elevated risk for lung cancer in the utility workers overall in comparison with the general population.
Case-Control Studies↗
Measurement of the cross section for gamma gamma -->pp-bar.
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Journal Article↗
Measurement of two-photon production of the chi c2.
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Journal Article↗
Conformational properties of four peptides corresponding to alpha-helical regions of Rhodospirillum cytochrome c2 and bovine calcium binding protein.
Four peptides corresponding to alpha-helical regions delimited by residues 63-73 and 97-112 of cytochrome c2 (Rhodospirillum) and residues 24-36 and 45-55 of bovine calcium binding protein are predicted to be alpha-helical by a recently developed method [Rooman, M., Kocher, J.P., & Wodak, S.J. (1991) J. Mol. Biol. 221, 961-979], synthesized by solid phase methods, and purified by HPLC, and their solution conformations are determined by NMR and CD. The observed conformational properties of these peptides in solution confirmed prediction results: in water/TFE (60/40, v/v) at room temperature, these peptides adopt an alpha-helical conformation, as shown by an extended pattern of strong, sequential dNN(i,i + 1) NOE cross-peaks, d alpha N(i,i + 1) NOEs of reduced intensity, several medium-range [d alpha N(i,i + 3), d alpha N(i,i + 4), d alpha beta-(i,i + 3)] NOE connectivities, small 3JH alpha N values, and more upfield alpha-proton chemical shifts. CD studies at different TFE concentrations and at room temperature provide further evidence of the propensity of these peptides to adopt an alpha-helical conformation in solution, as determined by the ellipticity values at 222 nm, and by deconvolution of the CD spectra. According to the method used, helicities in the range 34-50% and 55-75% are found for the 63-73 and 97-112 fragments of cytochrome c2, respectively, and in the range 53-80% and 42-65% for the fragments 24-36 and 45-55 of calcium binding protein in water/TFE (60/40, v/v) at 298 K. In addition, the experiments and predictions agree for those residues that are more flexible. Finally, the relevance of our results for the protein folding pathways is discussed.
Algorithms↗