Biomedical subjects

Barbara Miller

Publications and source records attributed to Barbara Miller.

15 recordsLinked to original sources

PubMed2005

Sentinel node biopsy after neoadjuvant chemotherapy in breast cancer: results from National Surgical Adjuvant Breast and Bowel Project Protocol B-27.

PURPOSE: Experience with sentinel node biopsy (SNB) after neoadjuvant chemotherapy is limited. We examined the feasibility and accuracy of this procedure within a randomized trial in patients treated with neoadjuvant chemotherapy. PATIENTS AND METHODS: During the conduct of National Surgical Adjuvant Breast and Bowel Project trial B-27, several participating surgeons attempted SNB before the required axillary dissection in 428 patients. All underwent lymphatic mapping and an attempt to identify and remove a sentinel node. Lymphatic mapping was performed with radioactive colloid (14.7%), with lymphazurin blue dye alone (29.9%), or with both (54.7%). RESULTS: Success rate for the identification and removal of a sentinel node was 84.8%. Success rate increased significantly with the use of radioisotope (87.6% to 88.9%) versus with the use of lymphazurin alone (78.1%, P = .03). There were no significant differences in success rate according to clinical tumor size, clinical nodal status, age, or calendar year of random assignment. Of 343 patients who had SNB and axillary dissection, the sentinel nodes were positive in 125 patients and were the only positive nodes in 70 patients (56.0%). Of the 218 patients with negative sentinel nodes, nonsentinel nodes were positive in 15 (false-negative rate, 10.7%; 15 of 140 patients). There were no significant differences in false-negative rate according to clinical patient and tumor characteristics, method of lymphatic mapping, or breast tumor response to chemotherapy. CONCLUSION: These results are comparable to those obtained from multicenter studies evaluating SNB before systemic therapy and suggest that the sentinel node concept is applicable following neoadjuvant chemotherapy.

Adult↗

PubMed2005

Use of a bioengineered skin equivalent for the management of difficult skin defects after pediatric multivisceral transplantation.

BACKGROUND: Primary wound closure is not always possible after pediatric multi-visceral transplantation because of oversized donor organs and/or intestinal or graft edema. We report our experience evaluating the safety and efficacy of Graftskin (Apligraf, Organogenesis, Canton, Mass), a bioengineered bi-layered human skin equivalent, for the management of difficult skin abdominal defects after multivisceral transplantation in a pediatric population. METHODS: A retrospective chart review was performed of pediatric multivisceral transplantation patients who were treated with Graftskin. Adverse events, course of wound reepithelialization, and time for complete closure were recorded. RESULTS: Four patients, 7 to 29 months old, were treated with Graftskin. One patient died because of unrelated reasons. Stimulation of the granulation, reepithelialization, and rapid reduction of the wound surface and depth occurred in the other 3 patients. Complete reepithelialization occurred within 5 months. No adverse events were noted. CONCLUSION: Graftskin was a successful treatment for difficult abdominal skin defects after liver and multivisceral transplantation in children.

Biomedical Engineering↗

PubMed2004

Insect-induced conifer defense. White pine weevil and methyl jasmonate induce traumatic resinosis, de novo formed volatile emissions, and accumulation of terpenoid synthase and putative octadecanoid pathway transcripts in Sitka spruce.

Stem-boring insects and methyl jasmonate (MeJA) are thought to induce similar complex chemical and anatomical defenses in conifers. To compare insect- and MeJA-induced terpenoid responses, we analyzed traumatic oleoresin mixtures, emissions of terpenoid volatiles, and expression of terpenoid synthase (TPS) genes in Sitka spruce (Picea sitchensis) following attack by white pine weevils (Pissodes strobi) or application of MeJA. Both insects and MeJA caused traumatic resin accumulation in stems, with more accumulation induced by the weevils. Weevil-induced terpenoid emission profiles were also more complex than emissions induced by MeJA. Weevil feeding caused a rapid release of a blend of monoterpene olefins, presumably by passive evaporation of resin compounds from stem feeding sites. These compounds were not found in MeJA-induced emissions. Both weevils and MeJA caused delayed, diurnal emissions of (-)-linalool, indicating induced de novo biosynthesis of this compound. TPS transcripts strongly increased in stems upon insect attack or MeJA treatment. Time courses and intensity of induced TPS transcripts were different for monoterpene synthases, sesquiterpene synthases, and diterpene synthases. Increased levels of weevil- and MeJA-induced TPS transcripts accompanied major changes in terpenoid accumulation in stems. Induced TPS expression profiles in needles were less complex than those in stems and matched induced de novo emissions of (-)-linalool. Overall, weevils and MeJA induced similar, but not identical, terpenoid defense responses in Sitka spruce. Findings of insect- and MeJA-induced accumulation of allene oxide synthase-like and allene oxide cyclase-like transcripts are discussed in the context of traumatic resinosis and induced volatile emissions in this gymnosperm system.

Acetates↗

PubMed2004

Simultaneous determination of fatty, dicarboxylic and amino acids based on derivatization with isobutyl chloroformate followed by gas chromatography-positive ion chemical ionization mass spectrometry.

Gas chromatography-mass spectrometry (GC-MS) with positive ion chemical ionization (PICI) using isobutane as reagent gas was applied for analysis of isobutoxycarbonyl/isobutyl derivatives of 13 fatty, 6 dicarboxylic and 13 amino acids in a single run. For all investigated compounds (except several amino acids) the quasimolecular ions [MH](+) were registered. Asparagine underwent fragmentation via decarboxylation followed by elimination of OC(4)H(9) ([M-117](+)), whereas serine and tyrosine produced the cluster ions [M+C(4)H(9)OCO](+). Estimated detection limits were 6-250 pg in the total ion current (TIC) mode and 3-10 times lower using the selected-ion monitoring (SIM) mode.

Amino Acids↗

PubMed2004

Prevalence of malignancy within cytologically indeterminate thyroid nodules.

BACKGROUND: The optimal management of cytologically indeterminate thyroid nodules is controversial given the variable malignancy rates reported in this patient population. We examined the prevalence of malignancy within cytologically indeterminate follicular thyroid lesions in an attempt to predict malignancy based on cytologic features. METHODS: Cytopathology reports obtained after fine-needle aspiration biopsy (FNAB) examination of indeterminate follicular thyroid lesions were examined over a 4-year period. The prevalence of malignancy on final histology was determined in 4 indeterminate cytologic categories. RESULTS: A total of 107 records were available (91 women, 16 men). The mean patient age was 45.4 +/- 16 years. Forty-eight patients (45%) underwent surgery and had histopathologic diagnosis, while 57 patients did not have surgery. The prevalence of malignancy in patients who underwent thyroidectomy was 42% (20 of 48). CONCLUSIONS: The high prevalence of malignancy within indeterminate follicular lesions may necessitate thyroidectomy for patients with indeterminate follicular lesions on FNAB examination.

Adenocarcinoma, Follicular↗

PubMed2004

Isolation of high-quality RNA from gymnosperm and angiosperm trees.

An improved protocol was developed for efficient and reliable extraction of high-quality total RNA and mRNA from various tissues of spruce (Picea spp.) and poplar (Populus spp.) trees, as well as other plant species. This method was specifically optimized for tissues with high content of polysaccharides, oleoresin terpenoids, and phenolic secondary metabolites, which often co-precipitate with RNA and inhibit subsequent reverse transcription. The improved protocol yielded up to 600 micrograms of total RNA per gram of tissue suitable for standard expressed sequence tags (ESTs), full-length cDNA library construction, and for microarray applications.

Chemical Fractionation↗

PubMed2004

Mold filling and microhardness of 1% Fe titanium alloys.

We examined the mold filling capacity and microhardness of two industrial 1% Fe titanium alloys: Super-TIX800 (Nippon Steel Corp.) (Fe: 0.910%, O: 0.370%, N: 0.005%) and Super-TIX800N (Nippon Steel Corp.) (Fe: 0.960%, O: 0.300%, N: 0.041%). Two wedge-shaped acrylic patterns (with 30 degrees or 15 degrees angles) were prepared. Each alloy was cast in a centrifugal casting machine. Mold filling was evaluated as the missing length between the tip of the casting and the theoretical tip. Vickers hardness of the edge of the castings was also determined. For both angles tested, there were no significant differences (p>0.05) in mold filling among these alloys and the control (CP Ti). The results of testing the microhardness near the cast surfaces indicated that the hardened reaction layers on these alloys were thinner at the edge compared to CP Ti.

Analysis of Variance↗

PubMed2003

Traumatic resin defense in Norway spruce (Picea abies): methyl jasmonate-induced terpene synthase gene expression, and cDNA cloning and functional characterization of (+)-3-carene synthase.

Picea abies (L.) Karst. (Norway spruce) employs constitutive and induced resin terpenoids as major chemical and physical defense-shields against insects and pathogens. In recent work, we showed that a suite of terpenoids, monoterpenoids and diterpenoids was induced in stems of Norway spruce after treatment of trees with methyl jasmonate (MeJA) (Martin et al., 2002). Increase of enzyme activities of terpenoid biosynthesis and accumulation of terpenoids was associated with MeJA-induced de novo differentiation of xylem resin ducts. The formation of defense-related traumatic resin ducts was also found in Norway spruce after attack by stem boring insects or after infestation with fungal pathogens. In the present study, we analyzed the traumatic resin response in Norway spruce further at the molecular genetic level. Treatment of trees with MeJA induced transient transcript accumulation of monoterpenoid synthases and diterpenoid synthases in stem tissues of Norway spruce. In screening for defense-related terpenoid synthase (TPS) genes from Norway spruce, a full-length monoterpenoid synthase cDNA, PaJF67, was isolated and the recombinant enzyme expressed in E. coli and functionally characterized in vitro. The cloned PaJF67 cDNA represents a new monoterpenoid synthase gene and the gene product was identified as 3-carene synthase. The enzyme encoded by PaJF67 forms stereospecifically (+)-3-carene (78% of total product) together with minor acyclic and cyclic monoterpenes, including the mechanistically closely related terpinolene (11% of total product). (+)-3-Carene is a characteristic monoterpene of constitutive and induced oleoresin defense of Norway spruce and other members of the Pinaceae.

Acetates↗

PubMed2003

The role of intestinal transplantation in the management of babies with extensive gut resections.

BACKGROUND/PURPOSE: Modern neonatal care, surgical treatment, and total parenteral nutrition (TPN) have improved survival rate for babies with extensive gut resections. The authors examined the role of intestinal transplantation in the treatment of these patients. METHODS: The authors reviewed all pediatric intestinal transplants performed for short bowel syndrome at our center (70 transplants performed between Aug 1994 and Feb 2002). Factors affecting patient survival were analyzed. RESULTS: Older patient age at the time of transplant was a significant factor favorably affecting patient survival (P =.031). Trends toward better survival rates were observed in those transplants performed more recently (P =.063), in those patients with greater body weight (P =.084), in those not hospitalized at the time of transplant (P =.14), and in those without concomitant liver failure (P =.12). Three-year survival rate for patients greater than age 2 years and without liver failure was 90%. However, 32% of our recipients underwent transplant at age less than one year, and most in this group (75%) had concomitant liver failure. CONCLUSIONS: For babies with irreversible intestinal failure, intestinal transplantation is a life-saving option. Results, which have recently improved, are best when transplantation compliments more conservative surgical treatments and TPN. However, there is a subset of patients who have liver disease early requiring urgent transplant.

Age Factors↗

PubMed2003

Development of a plant viral-vector-based gene expression assay for the screening of yeast cytochrome p450 monooxygenases.

Development of a gene discovery tool for heterologously expressed cytochrome P450 monooxygenases has been inherently difficult. The activity assays are labor-intensive and not amenable to parallel screening. Additionally, biochemical confirmation requires coexpression of a homologous P450 reductase or complementary heterologous activity. Plant virus gene expression systems have been utilized for a diverse group of organisms. In this study we describe a method using an RNA vector expression system to phenotypically screen for cytochrome P450-dependent fatty acid omega-hydroxylase activity. Yarrowia lipolytica CYP52 gene family members involved in n-alkane assimilation were amplified from genomic DNA, cloned into a plant virus gene expression vector, and used as a model system for determining heterologous expression. Plants infected with virus vectors expressing the yeast CYP52 genes (YlALK1-YlALK7) showed a distinct necrotic lesion phenotype on inoculated plant leaves. No phenotype was detected on negative control constructs. YlALK3-, YlALK5-, and YlALK7-inoculated plants all catalyzed the terminal hydroxylation of lauric acid as confirmed using thin-layer and gas chromatography/mass spectrometry methods. The plant-based cytochrome P450 phenotypic screen was tested on an n-alkane-induced Yarrowia lipolytica plant virus expression library. A subset of 1,025 random library clones, including YlALK1-YlALK7 constructs, were tested on plants. All YlALK gene constructs scored positive in the randomized screen. Following nucleotide sequencing of the clones that scored positive using a phenotypic screen, approximately 5% were deemed appropriate for further biochemical analysis. This report illustrates the utility of a plant-based system for expression of heterologous cytochrome P450 monooxygenases and for the assignment of gene function.

Cells, Cultured↗

PubMed2003

(E)-beta-ocimene and myrcene synthase genes of floral scent biosynthesis in snapdragon: function and expression of three terpene synthase genes of a new terpene synthase subfamily.

Snapdragon flowers emit two monoterpene olefins, myrcene and (E)-beta-ocimene, derived from geranyl diphosphate, in addition to a major phenylpropanoid floral scent component, methylbenzoate. Emission of these monoterpenes is regulated developmentally and follows diurnal rhythms controlled by a circadian clock. Using a functional genomics approach, we have isolated and characterized three closely related cDNAs from a snapdragon petal-specific library that encode two myrcene synthases (ama1e20 and ama0c15) and an (E)-beta-ocimene synthase (ama0a23). Although the two myrcene synthases are almost identical (98%), except for the N-terminal 13 amino acids, and are catalytically active, yielding a single monoterpene product, myrcene, only ama0c15 is expressed at a high level in flowers and contributes to floral myrcene emission. (E)-beta-Ocimene synthase is highly similar to snapdragon myrcene synthases (92% amino acid identity) and produces predominantly (E)-beta-ocimene (97% of total monoterpene olefin product) with small amounts of (Z)-beta-ocimene and myrcene. These newly isolated snapdragon monoterpene synthases, together with Arabidopsis AtTPS14 (At1g61680), define a new subfamily of the terpene synthase (TPS) family designated the Tps-g group. Members of this new Tps-g group lack the RRx(8)W motif, which is a characteristic feature of the Tps-d and Tps-b monoterpene synthases, suggesting that the reaction mechanism of Tps-g monoterpene synthase product formation does not proceed via an RR-dependent isomerization of geranyl diphosphate to 3S-linalyl diphosphate, as shown previously for limonene cyclase. Analyses of tissue-specific, developmental, and rhythmic expression of these monoterpene synthase genes in snapdragon flowers revealed coordinated regulation of phenylpropanoid and isoprenoid scent production.

Acyclic Monoterpenes↗

PubMed2003

Electron ionization mass spectra and their reproducibility for trialkylsilylated derivatives of organic acids, sugars and alcohols.

Mass spectra of trialkylsilyl derivatives of fatty acids, dicarboxylic acids, hydroxyacids, oxoacids, sugars, amino acids and alcohols were obtained. Amino acids were analyzed as tert-butyldimethylsilyl derivatives; all other model compounds were analyzed as trimethylsilyl derivatives. Reproducibility of the electron ionization (EI) mass spectra for the derivatives obtained was discussed. It was shown that, for many investigated derivatives, composition of the respective mass spectra depended greatly on ion source contamination. The trimethylsilylated alpha-tocopherol mass spectrum composition was most significantly influenced by ion source contamination. This compound can be used to test ion source contamination.

Alcohols↗

PubMed2003

Electron ionization and atmospheric pressure photochemical ionization in gas chromatography-mass spectrometry analysis of amino acids.

The mass spectra of tert-butyldimethylsilyl (TBDMS) derivatives of 17 amino acids were obtained using electron ionization (EI) and atmospheric pressure photochemical ionization (APPhCI) mass spectrometry. The APPhCI mass spectra for all of the derivatives except arginine were shown to consist of only molecular [M](+.) and quasimolecular [MH](+) ions whereas, in the case of EI, the compounds in question underwent a drastic fragmentation. The application of APPhCI to gas chromatography-mass spectrometry enables a reliable identification of the TBDMS derivatives of amino acids in a mixture, even if its components are only partially resolved, due to the unique molecular masses for each compound. Comparison of the respective positive-ion chemical ionization (PICI) mass spectra available in the literature with APPhCI spectra has shown that, in the case of PICI, unlike APPhCI, noticeable fragmentation occurs.

Amino Acids↗

PubMed2002

Extracorporeal photochemotherapy--the Columbia Presbyterian experience.

BACKGROUND: Cutaneous T Cell Lymphoma (CTCL) is a lymphoma of skin homing usually CD4 + lymphocytes. There are numerous treatments available both for the early as well as the more advanced stages of the disease. Extracorporeal photochemotherapy is a well-accepted form of treating CTCL. The purpose of our study was to review the experience of treating 20 CTCL patients with extracorporeal photochemotherapy (ECP) at Columbia Presbyterian Medical Center over a seven-year period. METHODS: The study was conducted as a retrospective chart review of these 20 patients. Summarized demographic characteristics included age at diagnosis, gender, and race. We analyzed the overall response by categorizing patients as having complete response, partial response, stable disease, and progressive disease. We also analysed the predictive value for three factors: peripheral blood CD4 : CD8 (< 10, > 10), LDH level (normal, elevated), and erythrodermic status (erythrodermic or nonerythrodermic). The potential prognostic variables were evaluated for linear association with response using Mantel-Haenszel chi-square tests. All statistical tests were two-sided with alpha = 0.05. The tests were considered to be exploratory and no adjustments for multiple testing were made. RESULTS: There was a significant linear association between response and CD4 : CD8. Patients with a ratio < 10 were more likely to respond than patients with a ratio > 10. There was a marginally significant linear association between response and LDH level. Patients whose LDH was not elevated at the start of treatment, tended to have a better response to ECP compared to patients with an elevated LDH. There was a suggestion of an association between erythroderma and response although this was not statistically significant. The majority of patients with erythroderma were responders compared to the majority of non-erythrodermic patients who were non-responders. The treatment was well tolerated with minimal side-effects. CONCLUSION: Apparent predictors of good response to ECP include erythroderma, a relatively low (closer to normal) peripheral CD4 : CD8, and a normal LDH. This report confirms reports from other institutions indicating that CTCL patients who are erythrodermic with a relatively intact immune system are optimal candidates for ECP.

Adult↗

PubMed2002

Distance learning in a school nurse credential program.

Distance learning, which encompasses many methodologies, is becoming a more readily available educational alternative. Because there are a limited number of school nurse credential programs and the demand for school nurses is increasing, distance learning may be a viable method of instruction. This article describes the authors' experiences organizing and presenting distance learning courses to five remote sites for students in a university school nurse credential program. After numerous inquiries, potential students from several areas were surveyed, and arrangements were made with universities in those areas to receive two-way audio and video transmissions of two seminar courses; later, two clinically oriented courses in the school nurse program. Students were able to complete their program requirements by taking equivalent course work at their local universities. Perceptions of students and the instructor, course evaluation, and practical suggestions are shared. Guidelines for potential students about selecting quality distance education programs are also noted.

California↗