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Biomedical subjects

M S Miller

Publications and source records attributed to M S Miller.

At least 55 records · Page 3Linked to original sources

Cytologic evaluation of lumpectomy margins in patients with ductal carcinoma in situ: clinical outcome.

BACKGROUND: Breast conservation therapy is controversial for ductal carcinoma in situ (DCIS) due to recently reported high recurrence rates. We believe that cytologic evaluation of lumpectomy margins improves efficiency and leads to a lower recurrence rate following lumpectomy for DCIS. METHODS: A prospectively accrued database of 1255 breast cancer patients at the H. Lee Moffitt Cancer Center and Research Institute was found to have 218 patients with DCIS (17.4%). Of those 218 cases, 114 were treated with lumpectomy, axillary dissection, and radiation therapy; the remaining 104 patients were treated with mastectomy with or without reconstruction. Imprint cytology was used to evaluate all lumpectomy margins. Permanent sections and imprint cytology were reviewed by the same pathologist. RESULTS: All lumpectomy specimens (116 tumors in 114 patients) were evaluated. The median follow up was 57.5 months (range 2-110 months). One hundred and three patients with 104 tumors were selected on the basis of pure DCIS (with or without microinvasion), and treated with lumpectomy, axillary dissection and radiation therapy. Of the 104 tumors utilizing attempted breast conservation therapy, 7 (6.6%) required mastectomy. There were 6 recurrences (6.1%) with a median time for recurrence of 47.5 months (range 27-85 months); four recurrences were comedo and two were noncomedo at original diagnosis. CONCLUSIONS: The determination of lumpectomy margins in DCIS patients using imprint cytology leads to an overall recurrence rate of 6.1% with reduction in operative time, and re-excision rate. Significant recurrence rates were associated with microinvasion and multifocal tumors (28%) versus simple DCIS at 5 years. Breast conservation therapy and surgical margin determination with imprint cytology for DCIS is a cost-effective and reliable method of treatment for simple DCIS.

Adult↗

Ki-ras mutations are an early event and correlate with tumor stage in transplacentally-induced murine lung tumors.

A previous study from this laboratory demonstrated that treatment of pregnant mice with 3-methylcholanthrene (MC) caused lung tumors in the offspring at 1 year after birth, the incidence of which correlated with fetal inducibility of Cyp1a1. Analysis by PCR amplification and allele-specific hybridization (ASO) of paraffin-embedded tumors generated from that study revealed the presence of point mutations in exon 1 of the Ki-ras gene. This work has now been expanded by PCR amplification and ASO analysis of 31 additional lesions. Point mutations were found in 37 of the 47 (79%) lesions analyzed in this and the previous study, the majority of which were G-->T transversions in the first or second base of codon 12. The mutational spectrum appeared to be dependent on the relative stage of differentiation of the lesion, as both the incidence of mutation and type of mutation produced correlated with malignant progression. Mutations occurred in 60% of the hyperplasias, 80% of the adenomas and 100% of the adenocarcinomas. In the lesions with mutations, GLY12-->CYS12 transversions occurred in 100% of the hyperplasias, 42% of the adenomas and 14% of the adenocarcinomas. The GLY12-->VAL12 transversions occurred in none of the hyperplasias, 42% of the adenomas and 57% of the adenocarcinomas. The remaining mutations, which consisted of ASP12 transitions and ARG13 transversions, occurred only in adenomas (17%) and adenocarcinomas (29%). Between this study and our previous analyses, the identity of the mutations obtained by ASO were confirmed by sequence analysis of eight of the 37 lesions that harbored mutations at the Ki-ras gene locus. There were no differences in the type or incidence of mutations relative to the metabolic phenotype or sex of the mice. These data suggest that mutational activation of the Ki-ras gene locus is an early event in transplacental lung tumorigenesis, and that the type of mutations produced by exposure to chemical carcinogens can influence the carcinogenic potential of the tumor. This may have prognostic significance in determining the malignant progression of the neoplasm.

Animals↗

Caffeine-induced contractions in developing rabbit heart.

Mature myocardium utilizes calcium released by the sarcoplasmic reticulum (SR) for cell contraction. Transient exposure of mature myocytes to caffeine is known to directly trigger Ca2+ release from the SR. In contrast, neonatal rabbit heart cells rely on transsarcolemmal Ca2+ influx for tension generation. SR function is decreased in immature heart and appears to play a minimal role as a calcium source. Accordingly, we hypothesized that neonatal rabbit myocytes would not respond to a caffeine pulse. Isolated neonatal and adult myocytes were paced to load the SR with calcium and then exposed to a 1-s pulse of 10 mM caffeine. As previously described, adult myocytes exhibited a brisk contraction in response to caffeine. Unexpectedly, neonatal myocytes also exhibited a similar, brisk response. These caffeine-induced contractions were not dependent on extracellular Ca2+ but were dependent upon the loading of SR Ca2+ stores. When SR Ca2+ stores were depleted by exposure to caffeine, mature myocytes exhibited only small, slow contractions in response to electrical field stimulation. Replenishing the SR Ca2+ stores resulted in normal, brisk contractions. In contrast, electrically stimulated contractions in immature myocytes were largely unaffected by caffeine-induced SR depletion. Thus, although neonatal myocytes are capable of loading and releasing calcium from the SR, such SR calcium release is not normally required for contraction in the developing heart. The minor role of SR Ca2+ release in immature rabbit heart may not result from immaturity of the SR, but rather from an inadequate mechanism to trigger SR calcium release.

Animals↗

Identification of insulin-like growth factor binding protein-2 as a biochemical surrogate marker for the in vivo effects of recombinant human insulin-like growth factor-1 in mice.

Recent studies indicate that a daily s.c. injection of 1 mg/kg of recombinant human insulin-like growth factor-1 (rhIGF-1) for 17 days is efficacious in enhancing the functional recovery of injured sciatic nerves in CD-1 mice. To identify and characterize surrogate marker(s) that are altered in association with the administration of an efficacious dose of rhIGF-1, dose-response curves (0.1, 1 and 10 mg/kg) and time course effects (0, 0.5, 3, 6 and 24 hr) were determined after acute (single) and chronic (once daily for 17 days) injections of rhIGF-1 in CD-1 mice. Plasma glucose levels decreased in a dose-dependent fashion after either acute or chronic injections of rhIGF-1 with maximal effects at 0.5 to 1 hr after administration of rhIGF-1. Among the three insulin-like growth factor binding proteins (IGFBPs) evaluated in the study, only IGFBP2 levels were consistently increased in a dose-dependent fashion with maximal effects 3 hr after the last of a series of injections of rhIGF-1. Furthermore, IGFBP2 levels increased at a dose of rhIGF-1 (1 mg/kg) that enhances the regeneration of injured sciatic nerves in mice. Chronic administration of insulin at doses that cause comparable decreases in plasma glucose to that of rhIGF-1 did not alter IGFBP2 levels or enhance hindlimb function suggesting that the beneficial effects of rhIGF-1 occur via activation of the type-I IGF receptor rather than the insulin receptor. Based on these criteria, IGFBP2 appears to be useful as a surrogate marker for determining the in vivo effects of rhIGF-1.

Animals↗

Soluble CD14 and lipopolysaccharide-binding protein from bovine serum enable bacterial lipopolysaccharide-mediated cytotoxicity and activation of bovine vascular endothelial cells in vitro.

Bacterial endotoxin (lipopolysaccharide, LPS) has potent proinflammatory properties toward many cell types, including vascular endothelial cells. Bovine endothelial cells are often used for investigations involving the vascular endothelium in vitro, and other bovine products such as fetal bovine serum are also widely utilized in research laboratories. Evidence is presented that soluble CD14 (sCD14) is present in bovine serum and that LPS-mediated activation and cytotoxicity to bovine endothelial cells in vitro are dependent on sCD14. LPS-mediated activation of endothelial cells was quantitated by measuring tissue factor expression using an activated factor X-related chromogenic assay. Concentrations of 0.1-5.0% fetal bovine serum in the culture medium promoted LPS-induced tissue factor expression on bovine endothelial cells, and anti-CD14 monoclonal antibody (mAb) (20 micrograms/ml) inhibited tissue factor expression, whereas control antibodies did not. LPS-mediated damage to endothelial cells was assayed using the MTT tetrazolium assay. We found that either serum or recombinant human soluble CD14 (rsCD14, 20-2000 ng/ml) was required for LPS-related endothelial cell damage and that anti-CD14 mAb inhibited cytotoxicity. In addition, bovine LPS-binding protein (LBP, 20 ng/ml) purified from bovine serum had no effect on LPS-mediated cytotoxicity, but bovine LBP greatly enhanced the cytotoxic effect of LPS plus rsCD14. Western blot analysis performed on fractionated bovine serum samples with anti-CD14 mAb revealed immunoreactivity with a 50-55-kd protein, a size consistent with sCD14. Evidence of endothelial cell-associated CD14 was not detected using an immunofluorescence technique on cell preparations, nor by Northern blot analysis. These results indicate the existence of sCD14 in bovine serum and that soluble bovine serum factors including sCD14 and LBP facilitate presentation of LPS to receptive cells.

Acute-Phase Proteins↗

Drug metabolic enzymes in developmental toxicology.

Although much is known about the metabolism of environmental toxicants in adult organisms, little information exists on the role of cytochrome P450 (CYP) enzymes during development. The developing organism is remarkably dynamic, presenting a constantly changing metabolic profile as various enzyme systems are activated or repressed. This may explain the markedly different sensitivities to various toxicants that are exhibited throughout the developmental period. The application of molecular biological methods has provided important information on the roles of these enzymes in modulating the response of the developing organism to toxicological exposures. The first talk will focus on the identification and role of CYPs during early organogenesis, particularly on how these enzymes influence the response of the conceptus and early embryo to toxic chemicals. The second presentation will discuss the identification of CYPs expressed during human development, as many of the enzymes present in adults are not expressed in the fetus. The third speaker will discuss the developmental consequences of loss of expression of particular metabolic enzymes, focusing on recent studies employing knockout mice to examine the role of drug metabolic enzymes during development. The last two talks will discuss some of the short- and long-term consequences of in utero exposures to toxic chemicals and the role of CYP in modulating the toxic response of the developing organism. The first of these will focus on the role of CYP2E1 in human fetuses during late gestation and the response of this enzyme to inducing agents such as alcohol. The last talk will discuss the role of CYP1A1 in the activation of the Ki-ras oncogene following in utero exposure to carcinogens as a mechanism for lung tumor formation in a pharmacogenetic mouse model.

Aging↗

Interpretation of calcifications in screen/film, digitized, and wavelet-enhanced monitor-displayed mammograms: a receiver operating characteristic study.

RATIONALE AND OBJECTIVES: The acceptance of filmless digital mammography is currently limited by digitization and display drawbacks, as well as bias toward hard-copy interpretation. In the current study, we evaluated a wavelet-based image enhancement method for the filmless interpretation of breast calcifications. METHODS: A set of 100 mammograms (58 with calcification clusters) was digitized at 105 microns and 4,096 gray levels per pixel and was processed with nonlinear filters and wavelets. Standard receiver operating characteristic analysis was performed by four radiologists, who independently read the films, the unprocessed digital images, and unprocessed and wavelet-enhanced digital images presented simultaneously. RESULTS: Statistical differences were observed between screen/film and unprocessed digitized mammography displayed on monitors. Differences were not significant when wavelet enhancement was included in the monitor display. Interobserver variation in the digitized reading was greater than in film reading, but the wavelet enhancement reduced the difference. CONCLUSION: Wavelet-enhanced digital mammograms may assist radiologists in diagnosing calcifications directly from computer monitors and may compensate for current technologic limitations. A study with a larger data-base is needed before this method is accepted for clinical use.

Breast Diseases↗

Mouse lung tumors exhibit specific Ki-ras mutations following transplacental exposure to 3-methylcholanthrene.

A pharmacogenetic mouse model was utilized to determine the role of Cyp1a1 expression on the formation of Ki-ras mutations in lung tumors following transplacental exposure to polycyclic aromatic hydrocarbons (PAHs). A backcross between Ah responsive male B6D2F1 mice and nonresponsive female DBA mice resulted in a litter in which both responsive and nonresponsive fetuses resided in the same nonresponsive maternal environment. Pregnant mothers received a single i.p. injection of either 10 or 30 mg/kg of 3-methylcholanthrene (MC) or olive oil vehicle on day 17 of gestation. At the higher dose of MC, the responsive offspring of both sexes had significantly (P < 0.05) higher incidences of lung tumors than their nonresponsive littermates. The male responsive mice also exhibited a significantly increased liver tumor incidence over the nonresponsive mice at the P < 0.05 level. Administration of 10 mg/kg of MC caused a very low incidence of lung tumors and did not result in the appearance of macroscopically visible liver tumors. Exons 1 and 2 of the Ki-ras gene were amplified from paraffin-embedded tissue samples. The PCR products were screened by allele-specific oligonucleotide hybridization (ASO). Thirteen of 16 lung tumors (81%) screened exhibited point mutations in the 12th or 13th codon, including seven tumors that contained GGT-->GTT (GLY12-->VAL12) transversions, four which exhibited GGT-->TGT (GLY12-->CYS12) transversions, and two which contained GGC-->CGC (GLY13-->ARG13) transversions. None of the tumors had mutations at codon 61. The results obtained by ASO were confirmed by cloning and sequence analysis of the PCR products from four of these tumors. Within the subset of 16 tumors examined in this study, the same types of mutations in the Ki-ras gene were generally present in both responsive and nonresponsive mice, although G-->C transversions were found in two tumors from a single responsive female mouse. Interestingly, while both males and females exhibited the GGT-->GTT mutations at codon 12, the GGT-->TGT transversion was only found in male mice. These results are consistent with a key role for Cyp1a1 in modulating individual susceptibility to cancer formation through the formation of reactive intermediates that bind to DNA and result in activating mutations in key regulatory molecules.

Animals↗

Deaf students' recall of Spanish vocabulary under three testing conditions.

This investigation examined the effects of three training conditions on deaf students' recall of Spanish word meaning as measured by performance on a Spanish vocabulary test. The conditions were; a) repeated written productions, b) repeated fingerspelling, and c) repeated silent reading of selected Spanish words and their English equivalents. Subjects were 30 deaf undergraduate students enrolled in introductory Spanish courses at Gallaudet University in Washington, DC. Researchers assigned 10 subjects to each of the 3 training groups. A 30 item pretest was administered to verify that the vocabulary was not known to the subjects. A posttest containing 25 items from the pretest was administered twice to the subjects. For short-term memory there were no statistically significant differences across the 3 conditions. For long-term memory scores under the repeated written condition were significantly higher than scores under fingerspelling and silent reading conditions. The use of a study strategy incorporating writing may enhance the learning of Spanish vocabulary by deaf college students. The strategy could also be applied to other foreign languages and a range of academic subjects for deaf students.

Deafness↗

Novel benzo[b]quinolizinium cations as uncompetitive N-methyl-D-aspartic acid (NMDA) antagonists: the relationship between log D and agonist independent (closed) NMDA channel block.

A series of permanently charged benzo[b]quinolizinium cations having lower lipophilicity than MK-801 or phencyclidine (PCP) were synthesized. Data relating agonist independent block of N-methyl-D-aspartic acid (NMDA) ion channels to log D are described. Closed channel access is predicted to result in a more noncompetitive profile of antagonism compared to selective open channel blockers, which are uncompetitive inhibitors. Reduced closed channel block may underlie the absence of PCP or MK-801-like behavioral side effects observed for benzo[b]-quinolizinium cations.

Animals↗

Novel NMDA antagonists: replacement of the pyridinium ring of 6,11-ethanobenzo[b]quinolizinium cations with heteroisoquinolinium cations.

Replacement of the pyridinium ring of 6,11-ethanobenzo[b]quinolizinium cations with thiazolium (4a and 4b) and N-methylimidazolium (4c and 4d) resulted in equipotent compounds in the [3H]TCP binding assay. The corresponding N-methyl-1,2,4-triazolium analogs were less potent in this assay. The thiazolium derivative 4b, with a Ki = 2.9 nM, is being evaluated as a possible neuroprotective N-methyl-D-aspartic acid (NMDA) antagonist.

Animals↗

Discovery of 6,11-ethano-12,12-diaryl-6,11-dihydrobenzo[b]quinolizinium cations, a novel class of N-methyl-D-aspartate antagonists.

6,11-Ethano-12,12-diaryl-6,11-dihydrobenzo[b]quinolizinium cations 8, a novel class of N-methyl-D-aspartate (NMDA) antagonists acting at the phencyclidine site, have been identified. Structure-activity relationship studies around the lead compound 8a led to the identification of 12g (WIN 67870-2), one of the most potent compounds in this series. Compound 12g has a Ki = 1.8 +/- 0.2 nM vs [3H]TCP binding, has 700-fold selectivity for binding to the open state of the NMDA receptor-ionophore, and was devoid of MK-801- and PCP-like behavioral effects in rats. Compound 12g was neuroprotective in cultured mouse cortical neurons and exhibited antiischemic activity in a rat middle cerebral artery occlusion/reperfusion model of focal ischemia.

Animals↗

Behavioral problems of adolescents with chronic physical illness: a comparison of parent-report and self-report measures.

This study reports on the extent of behavior problems in Israeli adolescents suffering from chronic illness. A comparison was made between parent-reported and self-reported behavioral symptomatology using the Child Behavior Checklist (CBCL) and the Youth Self-Report (YSR). 103 outpatients, aged 11-16 years, suffering from cystic fibrosis (CF), asthma, or hematological/oncological conditions were assessed. Healthy adolescents and adolescents referred for psychiatric assessment comprised the comparison groups. Parent- and self-reports were significantly positively correlated in each group (all chronically ill children r = .22; Healthy group r = .27; psychiatric group r = .50), but the correlations were particularly low (and non-significant) in younger adolescents with hematological/oncological conditions or HCF., pointing to the need for physicians to include parents' and adolescents' viewpoints in their assessments of these adolescents' psychosocial state. The mean number of parent-reported and self-reported behavior problems in the illness groups was no different from that of the Healthy group but significantly lower than that of the psychiatric group.

Adolescent↗

WIN 63480, a hydrophilic TCP-site ligand, has reduced agonist-independent NMDA ion channel access compared to MK-801 and phencyclidine.

NMDA channel blockers are potentially advantageous therapeutic agents for the treatment of ischemia and head trauma, which greatly elevate extracellular glutamate, because they should most effectively inhibit high levels of receptor activation. A novel high affinity TCP site ligand, WIN 63480, does not produce MK-801- or PCP-like behavioral activation at anti-ischemic doses. While WIN 63480, MK-801 and PCP were all observed to be effective blockers of open NMDA channels, WIN 63480 had much less access to closed NMDA channels. This difference may be due to the fact that WIN 63480 is hydrophilic (logD = -4.1) while MK-801 and PCP are lipophilic (logD = +1.8). In vivo, closed channel access may result in a non-competitive profile of antagonism for MK-801 and PCP compared to a more uncompetitive profile for WIN 63480. Release of glutamate, and depolarization, are likely to produce a high level of NMDA receptor activation in ischemic areas compared to normal tissue. Consequently, at anti-ischemic doses, WIN 63480 may produce less inhibition of physiological NMDA-mediated processes in neural systems involved in behavioral regulation than MK-801 or PCP, leading to an improved side effect profile.

Animals↗

Interleukin-6 secretion by bacterial lipopolysaccharide-stimulated bovine alveolar macrophages in vitro.

Interleukin-6 (IL-6) is a pluripotent cytokine that may play a role in pulmonary defense against bacterial pathogens. We have quantitated the response of bovine alveolar macrophages (bAM) to bacterial lipopolysaccharide (LPS; E. coli 055: B5) in vitro using the IL-6 sensitive 7TD1 cell line. Bacteria LPS in the absence of serum induced IL-6 secretion from bAM (1 x 10(6) ml-1) over a range of LPS concentrations from 10 ng ml-1 to 10 micrograms ml-1. This resulted in IL-6 levels ranging from approximately 5 to over 200 U ml-1.IL-6 secretion by from approximately 5 to over 200 U ml-1.IL-6 secretion by LPS-stimulated bAM was increased by 24 h poststimulation, and continued to increase up to 72 h after stimulation. Fetal bovine serum (FBS, 1% vol/vol; 320 micrograms ml-1) enhanced IL-6 secretion from macrophages in the presence of LPS by approximately 10-fold compared with LPS alone. A bovine serum fraction (1 microgram ml-1 protein) prepared using ion-exchange chromatography also markedly enhanced IL-6 secretion versus LPS alone. The stimulatory effect of IL-6-like activity in the bAM supernatants was neutralized by an anti-human IL-6 polyclonal antibody. Northern blot analysis revealed increased IL-6 mRNA at 2 h poststimulation with LPS + FBS, peak levels at 4 h, and levels were decreased by 6 h poststimulation. Results suggest that IL-6 is secreted by bovine alveolar macrophages, and that bacterial LPS and serum components synergize to produce this response.

Animals↗

Tumor biology of infiltrating lobular carcinoma. Implications for management.

OBJECTIVE: The purpose of this study was to characterize the biologic determinants that affect the behavior and management of infiltrating lobular cancer. METHODS: A prospectively accrued data base containing 1548 breast cancer cases was queried for specific pathologic and mammographic features. From this data base, 777 patients treated and followed-up at the H. Lee Moffitt Cancer Center were reviewed, and comparisons were made between the following three histologic subgroups: 661 infiltrating ductal (ID), 42 infiltrating ductal plus infiltrating lobular (ID + IL), and 74 infiltrating lobular (IL). RESULTS: Comparisons of the three histologic forms of breast cancer demonstrated the following: 1. At diagnosis tumors with IL components were larger than those with ID components (p < 0.001); in addition, a greater percentage of IL cancers were T3 lesions (14.8%), compared with ID cancers (4.5%). 2. Sizes of IL tumors were underestimated frequently by mammographic examinations when compared with pathologic measurements (p < 0.001). 3. By comparison to ID tumors, increasing IL tumor size is less likely to be associated with an increased number of metastatic lymph nodes per patient (p = 0.09). 4. Infiltrating lobular cancers treated by lumpectomy with cytologic surgical margin analysis more often gave false-negative results than did ID cancers (p < 0.001). 5. Infiltrating lobular cancers treated by lumpectomy required conversion to mastectomy over 2 times more frequently than ID cancers treated by lumpectomy. 6. Mastectomy was performed more frequently than lumpectomy for the treatment of IL versus ID tumors (p = 0.039). CONCLUSIONS: Infiltrating lobular cancers are biologically distinct from ID cancers. Although lumpectomy may be performed safely in selected patients, multiple difficulties exist in the management of IL cancer, particularly when breast conservation is chosen.

Adult↗

CD14 and tissue factor expression by bacterial lipopolysaccharide-stimulated bovine alveolar macrophages in vitro.

The membrane-associated CD14 receptor (mCD14) is a monocyte/macrophage differentiation antigen, and it has been demonstrated to serve as a receptor for bacterial lipopolysaccharide (LPS; endotoxin). Binding of LPS to mCD14 has been shown to be associated with LPS-induced macrophage, monocyte, and neutrophil activation in humans. In this report, we describe the presence and function of an mCD14-like receptor on bovine alveolar macrophages (bAM). An immunofluorescence technique and flow cytometric analysis indicated binding of anti-human CD14 monoclonal antibodies (MAb) My4, 3C10, and 60bd to bAM. Binding of anti-CD14 MAb (3C10 and MY4) was reduced over 20% by pretreatment of bAM with phosphatidylinositol-specific phospholipase C (0.5 to 1.0 U/ml), indicating that bovine mCD14 is a glycosyl phosphatidylinositol-anchored protein. In addition, pretreatment of bAM with anti-CD14 MAb decreased binding of 125I-labeled LPS to macrophages, suggesting that bovine mCD14 serves as a receptor for LPS. A cDNA probe based on the human sequence for CD14 was used in Northern (RNA) blot analysis, and hybridization to human monocyte CD14 yielded the expected 1.5-kb band. Hybridization to bovine mRNA yielded a 1.5-kb band plus an unexpected 3.1-kb band. Constitutive expression of bovine CD14 mRNA was observed, and the expression level was modestly elevated in bAM stimulated for 24 h with LPS (1 ng/ml) in the presence of bovine serum. The function and activation of bAM were assessed by quantitation of tissue factor (TF) expression on the cells using an activated factor X-related chromogenic assay and S-2222 substrate. LPS (1 ng/ml)-mediated upregulation of TF expression on bAM was dependent on the presence of bovine serum components, and TF expression was inhibited by anti-CD14 MAb. In addition, TF mRNA levels in LPS-stimulated bAM were decreased by pretreatment of cells with anti-CD14 MAb (MAb 60bd, 10 micrograms/ml).

Animals↗