Selected case from the Arkadi M. Rywlin International Pathology Slide Seminar: diabetic mastopathy.
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Adult↗
Biomedical subjects
C Fisher
Publications and source records attributed to C Fisher.
Primary hyperparathyroidism: an unusual cause of cervical myelopathy. A case report.
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Cervical Vertebrae↗
Modeling the interactions between a prosthetic socket, polyurethane liners and the residual limb in transtibial amputees using non-linear finite element analysis.
Continuing earlier studies into the relationship between the residual limb, liner and socket in transtibial amputees, we describe a geometrically accurate non-linear model simulating the donning of a liner and then a socket. The socket is rigid and rectified and the liner is a polyurethane geltype which is accurately described using non-linear (Mooney-Rivlin) material properties. The soft tissue of the residual limb is modelled as homogeneous, non-linear and hyperelastic and the bone structure within the residual limb is taken as rigid. The work gives an indication of how the stress induced by the process of donning the rigid socket is redistributed by the liner. Ultimately we hope to understand how the liner design might be modified to reduce discomfort. The ANSYS finite element code, version 5.6 is used.
Amputation Stumps↗
Synovial sarcoma: a clinicopathologic, staging, and prognostic assessment.
PURPOSE: Synovial sarcoma (SS) is a common soft tissue sarcoma (STS) with a propensity for young adults and notable sensitivity to chemotherapy (CT). This study provides a current clinicopathologic, staging, and prognostic assessment for SS. The problems with the current American Joint Committee for Cancer (AJCC) Staging System in relation to SS are discussed. METHODS: Review of a prospective database supplemented by retrospective data. RESULTS: One hundred fifty patients were assessed; median age was 30 years and median follow-up was 52 months. Overall actuarial 5-year survival rate was 57%. Size trend, but not a cutoff of less than 5 cm versus > or = 5 cm, was a prognostic indicator (P <.001). The current AJCC/International Union Against Cancer Staging System differentiated prognosis less well than the recently proposed Royal Marsden Hospital Staging System. Age greater than 20 years at diagnosis implied worse prognosis. A local recurrence event was associated with a worse survival (P <.001). Therapeutic CT was administered to 55 patients. Eleven of 19 patients had an objective response to a combination of ifosfamide and doxorubicin. Four cases had complete response after CT. Twenty-one patients had pulmonary metastasectomy, with an actuarial 5-year survival rate of 23%. CONCLUSION: SS tends to affect young people. In this subtype of STS, size trend is the most significant influence on stage and hence survival; however, smaller SSs have an unexpectedly poor prognosis. Adequate local control may affect survival. SS is often chemosensitive, and given its poor prognosis, multicenter trials of adjuvant therapy are warranted.
Adolescent↗
Earthquake-induced changes in a hydrothermal system on the Juan de Fuca mid-ocean ridge
Hydrothermal vents on mid-ocean ridges of the northeast Pacific Ocean are known to respond to seismic disturbances, with observed changes in vent temperature. But these disturbances resulted from submarine volcanic activity; until now, there have been no observations of the response of a vent system to non-magmatic, tectonic events. Here we report measurements of hydrothermal vent temperature from several vents on the Juan de Fuca ridge in June 1999, before, during and after an earthquake swarm of apparent tectonic origin. Vent fluid temperatures began to rise 4-11 days after the first earthquake. Following this initial increase, the vent temperatures oscillated for about a month before settling down to higher values. We also observed a tenfold increase in fluid output from the hydrothermal system over a period of at least 80 days, extending along the entire ridge segment. Such a large, segment-wide thermal response to relatively modest tectonic activity is surprising, and raises questions about the sources of excess heat and fluid, and the possible effect on vent biological communities.
Journal Article↗
A breakdown of symmetry in the folding transition state of protein L.
The 62 residue IgG binding domain of protein L consists of a central alpha-helix packed on a four-stranded beta-sheet formed by N and C-terminal beta-hairpins. The overall topology of the protein is quite symmetric: the beta-hairpins have similar lengths and make very similar interactions with the central helix. Characterization of the effects of 70 point mutations distributed throughout the protein on the kinetics of folding and unfolding reveals that this symmetry is completely broken during folding; the first beta-hairpin is largely structured while the second beta-hairpin and helix are largely disrupted in the folding transition state ensemble. The results are not consistent with a "hydrophobic core first" picture of protein folding; the first beta-hairpin appears to be at least as ordered at the rate limiting step in folding as the hydrophobic core.
Amino Acid Substitution↗
Identification of a C-terminal cdc25 sequence required for promotion of germinal vesicle breakdown.
Glutathione S-transferase (GST)-cdc25B(31-566) induced germinal vesicle breakdown (GVBD) when microinjected into Xenopus oocytes. Purified, N-terminally truncated forms of cdc25B did not induce GVBD, even though many had phosphatase activity and activated cdc2 in vitro. N-terminally truncated forms of cdc25B inhibited induction of GVBD by longer forms of the enzyme suggesting a direct interaction in vivo. cdc25B(356-556), but not cdc25B(364-529), inhibited GVBD induction by GST-cdc25B(31-566) suggesting that a region of cdc25B near to the C-terminus was responsible for the inhibition. To determine the region of peptide sequence that was inhibitory, cdc25B(356-556) was subjected to proteolysis with endoproteinase lys-C. Following a demonstration that the resulting peptide mixture inhibited GST-cdc25B-dependent GVBD, a series of peptides spanning amino acids at the C-terminus were synthesized. The peptide TRSWAGERSR inhibited GVBD induced by GST-cdc25B. An alanine scan of the peptide revealed residues critical for GVBD inhibition, and site-directed mutagenesis of the corresponding residues in GST-cdc25B(31-566) eliminated its ability to induce GVBD. These results demonstrate that a cdc25B C-terminal domain, involved in dominant-negative inhibition of GVBD-competent cdc25B, is required for induction of GVBD following microinjection into oocytes.
Amino Acid Sequence↗
Upregulation of estrogen receptors in the forebrain of aromatase knockout (ArKO) mice.
Estrogens have numerous reproductive and nonreproductive functions in brain. The actions of estrogens are mediated by estrogen receptors (ERs), and estrogens are believed to down-regulate their own receptors in many tissues. Assuming this to be true, if estrogens are removed there should be an upregulation of ERs. We have developed a mouse model in which estrogen synthesis is completely eliminated by homologous recombination to delete the gene encoding aromatase cytochrome P450 (P450(arom)). The P450(arom) enzyme catalyzes the synthesis of estrogens from androgens in the brain. The localization and density of ERs was studied in the brains of aromatase knockout (ArKO) and wild type male mice by using immunohistochemistry with a peptide antibody to ERalpha (ER-21) and computer imaging. In the wild-type animals a high density of ERalpha was found in a small number of hypothalamic cells; in the medial preoptic area, periventricular, arcuate, and ventromedial nuclei. A low and medium density of ERalpha was observed in cells of the lateral preoptic area, supraoptic, bed nucleus of the stria terminalis, and in central, medial and anterior cortical amygdaloid nuclei. The number of cells containing ERalpha-immunoreactivity was significantly increased (244%) in the medial preoptic area of the ArKO mice. In neither wild type nor ArKO animals was immunoreactivity observed in the cerebral cortex or striatum. There was intense ER-immunostaining in the nucleus of neurons in both wild type and ArKO mice. These data indicate that in the absence of estrogens there is as much as a 2-fold increase in the number of cells with ERalpha-immunoreactivity in certain hypothalamic and limbic regions. Thus, estrogens can down-regulate ERalpha in brain.
Animals↗
Atomic quadrupolar photoemission asymmetry parameters from a solid state measurement
A method for measuring the asymmetry parameter gamma arising from dipole-quadrupole interference in core-level photoemission is proposed which is based on condensed thin films and exploits the influence of this asymmetry in photoemission monitoring of x-ray standing wave field absorption. The high density of material in this method offers some advantages over a conventional gas-phase measurement. Results are presented for C, O, and F 1s photoemission at photon energies around 3 keV. The combined nondipole asymmetry factor (delta+gamma/3) for non- s-states can be determined in a similar way.
Journal Article↗
Epithelioid sarcoma: the clinicopathological complexities of this rare soft tissue sarcoma.
BACKGROUND: Epithelioid sarcoma is a rare high grade soft tissue sarcoma with a known propensity for locoregional recurrence. The literature is limited on other characteristics such as frequency of multifocal disease at presentation, the relationship of presenting size of the primary lesion to prognosis, and the ability of current staging systems to predict prognosis. METHODS: Review of the Royal Marsden National Health Service Trust (RMH) experience of 37 cases over 21 years. RESULTS: The mean age was 29 years, with male predominance (2.7:1), and distal limb locations were most common (56%). Five patients presented with multifocal local disease. Median follow-up was 88 months in the 19 patients still alive. The 5- and 10-year actuarial overall survival was 70% and 42%, respectively. Tumors deep to the investing fascia had a worse prognosis than superficial tumors. Regional metastasis events were also associated with significantly worse overall survival. Local recurrence, size of 5 cm or larger, and regional metastasis events were predictive of worse distant metastasis-free survival. Tumor size (<5 cm vs. > or =5 cm), local recurrence events, sex, and site were not significant predictors of survival. The American Joint Committee on Cancer/International Union Against Cancer staging systems and the recently proposed RMH staging system of the Royal Marsden National Health Service Trust provided poor differentiation of prognosis in epithelioid sarcoma. The 5-year actuarial local recurrence rate was 35%. The 5-year actuarial regional nodal metastasis rate was 23%. The actuarial 5-year distant metastasis rate was 40%, with pleuropulmonary metastases the most common site of metastatic disease, and 35% of pleuropulmonary metastases presented with pleural effusion. Median post-distant metastasis survival was 8 months. CONCLUSIONS: Epithelioid sarcoma has unusual clinical behavior compared with other high grade soft tissue sarcoma. It has a propensity for multifocal disease at presentation, local recurrence, regional metastasis, and particularly poor prognosis after regional or distant metastatic disease. Size and stage according to the American Joint Committee on Cancer/International Union Against Cancer are unreliable predictors of prognosis.
Adolescent↗
Immunoblot analysis of CD34 expression in histologically diverse neoplasms.
CD34 is a heavily glycosylated transmembrane protein of approximately 110 kd whose function is essentially uncharacterized. First identified in a myeloid leukemia cell line, immunohistological reactivity with anti-CD34 antibodies is also encountered in a histologically diverse subset of nonhematolymphoid neoplasms including angiosarcoma, solitary fibrous tumors, epithelioid sarcomas, spindle cell lipomas, dermatofibrosarcoma protuberans, and myofibroblastomas. Immunohistological reactivity for CD34 in hematopoietic stem cells and endothelial cells has been shown to correspond to the expression of the CD34 protein. With the exception of gastrointestinal stromal tumors, CD34 protein expression has not been investigated in other CD34 immunohistologically reactive nonhematolymphoid neoplasms. We undertook this study to examine whether the observed reactivity for anti-CD34 antibodies in apparently unrelated tumors is due to the expression of the same protein or whether shared epitopes elaborated by other proteins could account for this reactivity. Immunoblot analyses with anti-CD34 antibodies of six different CD34 immunohistologically reactive lesions show the same approximately 110-kd molecular weight protein. In addition, two cases of dermatofibrosarcoma protuberans show double bands at approximately 110 kd. Laser-capture microdissection of CD34 immunohistologically reactive epithelioid sarcoma and nonreactive epidermal cells illustrates that this reactivity is specific to tumor cells. These results show that the observed immunohistological reactivity with anti-CD34 antibodies is due to the expression of the CD34 protein and not to shared epitopes on unrelated proteins.
Adolescent↗
IKKalpha-/- mice share phenotype with pupoid fetus (pf/pf) and repeated epilation (Er/Er) mutant mice.
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Animals↗
Incidence of P-glycoprotein overexpression and multidrug resistance (MDR) reversal in adult soft tissue sarcoma.
Multidrug resistance (MDR) is a widespread problem in the treatment of neoplastic diseases and may limit the effectiveness of treatment of adult soft tissue sarcomas (STS). We examined the levels of expression of the MDR marker P-glycoprotein (Pgp) in fresh, surgical material and matched paraffin-embedded tissue using MRK-16 and JSB-1 monoclonal antibodies. Using fresh tumour material in short-term culture an assessment of doxorubicin sensitivity (MTT assay) and MDR modulation using PSC-833 in daunorubicin (DNR) accumulation experiments (FACS analysis) was carried out. 44 patients were studied at various disease stages with a mean follow-up duration of 487 days (range: 45-1095 days). Immunocytochemistry and immunohistochemistry showed 62% and 58%, respectively, of STS samples were positive for Pgp. Patients showing negative Pgp expression had a median survival of 544 days versus 431 days for Pgp-positive patients (P=0.311), with disease-free survival medians of 508 and 355 days, respectively (P=0.203). In vitro doxorubicin sensitivity was not informative in this respect and there was no apparent relationship between this and Pgp expression. Eleven out of 29 samples evaluated for MDR modulation showed enhanced tumour cell DNR accumulation. However, the effects of PSC-833 on drug accumulation in clinical material were modest compared with those seen for MDR cell lines, with a maximum of only 20% enhancement. Moreover, there was no relationship between the extent of PSC-833 effects on accumulation and the levels of Pgp seen in the STS samples. Nevertheless, we show evidence that a proportion of cases of STS express moderate to high levels of Pgp. There may be a role for MDR modulating agents in association with doxorubicin in the treatment of these tumours, either in the adjuvant setting or at first relapse.
ATP Binding Cassette Transporter, Subfamily B, Mem↗
Myofibromas presenting in the oral cavity: a series of 9 cases.
OBJECTIVES: Solitary myofibromas are well described in the head and neck, but oral examples are less well known, and jaw lesions are rare. We studied the clinicopathologic features of a series of such lesions. DESIGN: Nine cases of oral myofibromas were retrieved from archives and studied. RESULTS: Two cases involved the mandible (intraosseous), 3 involved the gingiva, 2 involved the tongue, and 2, the hard palate. There were 4 men and 5 women, aged 9 months to 50 years (mean, 24 years; median, 27 years). Deep lesions showed typical histology, with paucicellular lobules and intervening hemangiopericytoma-like zones. In ulcerated submucosal lesions, these features blended superficially with cellular fascicles. The tumors expressed smooth muscle actin but lacked desmin and S100 protein. None of the tumors recurred or metastasized. CONCLUSION: Myofibromas appear in osseous, intramuscular, and submucosal aspects of the oral cavity. Ulceration imparts a fascicular appearance that makes superficial biopsy specimens difficult to interpret.
Actins↗
Glycochenodeoxycholic acid (GCDC) induced hepatocyte apoptosis is associated with early modulation of intracellular PKC activity.
The effect of GCDC-induced apoptosis on PKC activity and PKC's role in GCDC-induced hepatocyte apoptosis is unclear. The specific aims of this study were to determine if GCDC-induced apoptosis changed intracellular PKC activity and if modulation of PKC activity affected GCDC-induced hepatocyte apoptosis. Apoptosis was induced in isolated hepatocytes using GCDC. PKC activity was measured and specific PKC and calpain inhibitors were used to study the effects of PKC and calpain modulation on GCDC-induced apoptosis. After 4 h exposure, 50 microM GCDC induced apoptosis in 42% of hepatocytes. Intracellular PKC activity decreased to 44% of controls 2 h after exposure of hepatocytes to GCDC (p < 0.001). Pre-incubation of hepatocytes with the calpain protease inhibitor restored PKC activity in GCDC exposed hepatocytes to 91 +/- 5% of control cells. Pre-incubation of hepatocytes with a calpain inhibitor decreased GCDC-induced apoptosis as did pre-incubation with the PKC activating phorbol ester, PMA. The combination of calpain inhibition and PMA further reduced GCDC-induced apoptosis but caused low level hepatic apoptosis. Inhibition of PKC with chelerythrine also substantially reduced GCDC-induced hepatocyte apoptosis. GCDC-induced apoptosis is associated with decreases in total cellular PKC activity, which appear to be dependent on intracellular calpain-like protease activity. The combination of protease inhibition and phorbol ester pretreatment preserved total cellular PKC activity and decreased GCDC-induced apoptosis but induced low level apoptosis in the absence of GCDC exposure. PKC inhibition also decreased GCDC-induced hepatocyte apoptosis highlighting the complex interactions of PKC and proteases during GCDC-induced apoptosis.
Animals↗
Beta-thalassaemia intermedia in Lebanon.
Approximately one third of thalassaemia patients on record in Lebanon have thalassaemia intermedia. We have analysed three factors in a panel of 73 patients with this less severe form of the disease in our population: mild beta-globin gene mutations, deletions in the alpha-globin gene and the presence of a polymorphism for the enzyme Xmn I in the Ggamma-promoter region. The results show that the most important contributing factor is the beta-genotype: 68% of patients have a mild beta+ mutation (IVSI-6, cd29, -88 or -87), while 26% of patients are positive for the Xmn I polymorphism associated with increased production of HbF, which showed strong linkage to particular mutations (IVSII-1, cd8 and cd30). However, the genotype phenotype correlation is difficult, because many patients were initially misdiagnosed as thalassaemia major and were started early on regular blood transfusions, which was stopped later on. This illustrates well the importance of an early accurate diagnosis of thalassaemia intermedia for appropriate clinical management.
Adolescent↗
Value of the mesothelium-associated antibodies thrombomodulin, cytokeratin 5/6, calretinin, and CD44H in distinguishing epithelioid pleural mesothelioma from adenocarcinoma metastatic to the pleura.
Until recently, the standard approach of most laboratories in distinguishing epithelioid pleural mesothelioma from metastatic adenocarcinoma has been a negative result from a panel of adenocarcinoma-associated antibodies. However, several "mesothelium-associated" antibodies have been proposed as useful in this situation, and we have applied four of these putative mesothelioma markers--thrombomodulin, cytokeratin 5/6, calretinin, and CD44H--to a series of 61 epithelioid pleural mesotheliomas and 63 metastatic adenocarcinomas with known primary sites (lung = 19; breast = 21; ovary = 6; colon = 10; kidney = 4; uterus, epididymis, pancreas = 1 case each). Of the mesotheliomas, 55 of 61 (90%) stained for thrombomodulin, 56 of 61 (92%) for cytokeratin 5/6, 47 of 51 cases (92%) were positive for calretinin, and 39 of 43 (91%) were positive for CD44H. Of the metastatic adenocarcinomas, 12 of 63 (19%) cases were positive for thrombomodulin, 9 of 63 (14%) were positive for CK5/6, and 27 of 60 (45%) were positive for CD44H. With calretinin, only 1 case of 59 (2%) showed positive nuclear staining. All four antibodies stained reactive mesothelium; thrombomodulin also stained endothelium; and CD44H variably stained lymphocytes, macrophages, and fibroblasts. We conclude that all four antibodies show high sensitivity for epithelioid mesothelioma, but only calretinin (98%), cytokeratin 5/6 (86%), and thrombomodulin (81%) show sufficient specificity for practical use in this situation.
Adenocarcinoma↗
Interaction between the serotonin transporter gene and neuroticism in cigarette smoking behavior.
Cigarette smoking behavior is influenced by both personality traits and inherited factors. Previous research showed that neuroticism-a broad personality domain that includes anxiety, depression, impulsiveness and vulnerability-increases the risk of being a smoker, primarily because of difficulty in quitting. Neuroticism has also been associated with the 5-HTTLPR, a functional polymorphism in the promoter for the serotonin transporter gene. We used population and family-based methods to analyze the joint effects of the 5-HTTLPR and neuroticism on smoking behavior in a population of 759 never, current, and former smokers, all members of sib-pairs. Our main finding is that smoking behavior is influenced by an interaction between neuroticism and 5-HTTLPR genotype. Specifically, neuroticism was positively correlated with current smoking and negatively associated with smoking cessation in individuals and siblings with poorly transcribed 5-HTTLPR-S genotypes, but not in those with the more highly expressed 5-HTTLPR-L genotype. Individuals with both a 5-HTTLPR-S genotype and a high level of neuroticism had the greatest difficulty in quitting smoking. These data, if replicated, suggest that smoking behavior is more strongly influenced by the combination of the serotonin transporter gene and neuroticism than by either factor alone, and that personality scores and 5-HTTLPR genotype may predict the clinical efficacy of certain smoking cessation drugs.
Adolescent↗