Biomedical subjects

Barbara Miller

Publications and source records attributed to Barbara Miller.

5 recordsLinked to original sources

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

(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↗

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↗