Comparison of the characteristics of Mycobacterium tuberculosis isolates from sputum and lung lesions in chronic tuberculosis patients.

Mycobacterium tuberculosis (Mtb) in sputum originates from lung cavities in tuberculosis (TB) patients. But drug susceptibility testing (DST) of sputum Mtb can not be conducted the same as in the lung because mutagenesis of bacilli may be happening in the lung during treatment and result in the possibility of the presence of heterogeneous drug-resistant subpopulations in the different lung lesions. This could be one of the reasons for low cure rates for multi-drug resistant (MDR)-TB. We studied the resected lungs of nine surgery patients with chronic TB. The isolates isolated from the sputum and different lung lesions of each patient were tested for phenotypic DST and genotyped using restriction fragment length polymorphism (RFLP) typing method. Genetic analysis to resistance to first and second line drugs was also performed. Five of nine patients were MDR-TB and three XDR-TB. DST results for ten anti-TB drugs were in accordance among different lung lesions in eight patients. However, only three of these eight patients showed the concordance of DST with sputum. Even though the isolates were heteroresistant, genotyping them by RFLP showed the clonal population in each individual patient. Six of eight followed-up patients achieved successful cure. In conclusion, the heteroresistance between sputum and lung lesions and a clonal population without mixed infection might provide useful information in establishing treatment regimen and surgery decision for MDR- and XDR-TB.

Impact of IL-1 receptor antagonist gene polymorphism on schizophrenia and bipolar disorder.

OBJECTIVES: Variable levels of cytokines were observed in patients with schizophrenia and bipolar disorder, and an especially high level of interleukin-1 (IL-1) was detected in schizophrenia patients. It is known that IL-1 receptor antagonist (IL-1RA) binds to IL-1 receptors and inhibits the receptor binding of IL-1alpha and IL-1beta. METHODS: In this study, the association between the variable number of tandem repeats polymorphism of the IL-1RA gene and schizophrenia (n=269) and bipolar disorder (n=83) was investigated. RESULTS: The genotype distribution and allele frequency were significantly different between schizophrenic patients and the control group (P<0.05); however, there were no prominent differences between bipolar patients and the control group. The carriage rate for the IL1RN*2 allele was associated with higher risk of schizophrenia (odds ratio=2.24). CONCLUSIONS: This study indicates that IL-1RA could be a candidate gene for susceptibility to schizophrenia.

High-level production of human growth hormone in Escherichia coli by a simple recombinant process.

Procedures have been devised for producing in Escherichia coli high yields of purified recombinant human growth hormone (hGH), by utilizing N-terminal pentapeptide sequence of human tumor necrosis factor-alpha, histidine tag and enterokinase cleavage site as a fusion partner. The fusion protein was produced as a soluble protein at the beginning of gene expression, but progressively became insoluble in Escherichia coli cytoplasm. The insoluble protein was solubilized by simple alkaline pH shift and purified to near homogeneity by Ni(2+)-chelated affinity chromatography. Following specific enterokinase cleavage, the recombinant hGH was purified by one-step anion exchange chromatography. The ease and speed of this recombinant process, as well as the high productivity, makes it adaptable to the large-scale production of hGH. Moreover, the highly efficient fusion partner could be applied to the production of other therapeutically important proteins.

Side chain modified sterols as probes into insect molting hormone metabolism. II: synthesis of monofluorocholesterols.

The hydroxylations of the cholesterol side chain at C-20, 22, and 25 are key terminal events in ecdysone biogenesis. We have prepared the C-20, C-22, C-24, and C-25 monofluorinated cholesterols as potential inhibitors of these hydroxylation events, and preliminary bioassay results in Manduca sexta are reported. The synthesis of [26(14)C]-20-fluorocholesterol is also described. Although the 20-, 22-, and 25-monofluorocholesterols do not appear to affect larval growth and development, the 24-fluoro isomer shows a moderate retardation of growth and a modest increase in mortality.

Enhanced production of human mini-proinsulin in fed-batch cultures at high cell density of Escherichia coli BL21(DE3)[pET-3aT2M2].

Synthesis of recombinant protein (human mini-proinsulin) is investigated in fed-batch cultures at high cell concentration of recombinant Escherichia coli BL21(DE3)[pET-3aT2M2]. Transcription of the recombinant gene is controlled by a T7 promoter system. The human mini-proinsulin is characterized by a C-chain peptide consisting of only nine amino acids, whereas the C-chain peptide of natural human proinsulin is made up of 35 amino acids. It is expressed in a fusion protein with a small fusion partner (a peptide with 18 amino acids) and finally aggregated into insoluble inclusion bodies in cytoplasm of recombinant E. coli. The fermentative production of this small fusion mini-proinsulin may be of great advantage in enhancing the yield of human insulin. To find an optimum induction strategy, effects of various key cultivation variables on the mini-proinsulin production are examined in high cell density fed-batch cultures. No general correlation is found between preinduction specific growth rate and recombinant protein synthesis, which confers a flexibility in choosing the feeding strategy of preinduction media for achieving the high cell density cultures. A culture temperature below 37 degrees C is unfavorable for recombinant gene expression, and the T7-based expression system is almost completely repressed at 30 degrees C. The nutrient glucose and yeast extract concentration in postinduction feed media is optimized by applying a statistical method for medium optimization, i.e. response surface methodology, and an effective amount of inducer molecule (IPTG) is determined to maximize the specific recombinant protein formation. The mini-proinsulin production in E. coli culture is significantly influenced by the volumetric feed rate of postinduction media, which is shown to be closely related to the plasmid copy number in the recombinant cell. Consequently, in a single-stage fed-batch process, the mini-proinsulin concentration is increased up to 7 g/L, approximately 62 wt % of which corresponds to mature human insulin. A two-stage fed-batch fermentation process, with recombinant cell growth occurring at a constant growth rate and constant cell concentration in a growth fermenter and mini-proinsulin production in an induction fermenter, is designed, and its efficacy in increasing volumetric productivity of mini-proinsulin is demonstrated.

Prolonged blood circulation of methotrexate by modulation of liposomal composition.

Prolonged circulation by liposomal incorporation has been shown to enhance the therapeutic efficacy of drugs in many cases. The purpose of this study was to investigate whether the prolonged circulation of methotrexate (MTX) can be achieved by modulating the liposomal compositions. Various compositions of liposomes were prepared with 2:1 of phosphatidylcholine (PC) and cholesterol (CH) with or without distearoylphosphatidyl-ethanolamine-N-poly(ethyleneglycol) 2000 (DSPE-PEG). The MTX encapsulation efficiency depended on the type of PC used. It also appeared to increase by inclusion of DSPE-PEG. The size of liposomes decreased by the inclusion of DSPE-PEG. The inclusion of DSPE-PEG lowered the plasma-induced release of MTX from EggPC/CH and DPPC/CH liposomes, suggesting its enhancement effect on the liposomal stability. After intravenous injection to rats, the pharmacokinetics and biodistribution of MTX were significantly changed by liposomal incorporation and also by the composition of liposomes. The total body clearance of MTX incorporated in EggPC/CH, DPPC/CH, EggPC/CH/DSPE-PEG, and DPPC/CH/DSPE-PEG liposomes decreased 4.4-, 14.9-, 24.5-, and 53.1-fold, compared with that of free MTX. The ratio of MTX concentration in blood to liver and spleen after injection of DPPC/CH, EggPC/CH/DSPE-PEG, and DPPC/CH/DSPE-PEG liposomes was 5.4-, 8.5-, and 13.5-fold higher than that of EggPC/CH liposomes. Furthermore, the accumulation of MTX in the kidney, one of the organs in which MTX exhibits its toxicity, was significantly lowered by liposomal incorporation, especially by DSPE-PEG-containing liposomes. Taken together, DPPC/CH/DSPE-PEG liposomes most effectively prolonged the blood circulation, and reduced hepatosplenic and kidney uptake of MTX. DPPC/CH/DSPE-PEG liposomes may have potential as an efficient delivery system for MTX.

3D reconstructions of spinal segmental arteries using CT angiography: applications in minimally invasive spinal procedures.

BACKGROUND AND PURPOSE: Injury to spinal segmental arteries may potentially occur during spinal surgery, particularly during anterior or minimally invasive approaches. Use of a noninvasive radiologic tool to evaluate these arteries before surgery may reduce this risk. MATERIAL AND METHODS: We performed spinal CT angiography and reconstructed 3D images of segmental arteries in 41 patients. We classified the pathways and locations of the segmental arteries into 4 zones (A, B, C, and D) according to pedicle and vertebral endplates. We designated segmental arteries from T8 to L1 as "high-level segmental arteries" and those from L2 to L4, as "low-level segmental arteries." We compared the distribution of segmental arteries between these 2 groups. We also investigated anatomic variations of segmental arteries and the rate of occurrence of the artery of Adamkiewicz. RESULTS: In all patients, 3D reconstruction images from spinal CT angiography clearly showed the pathways of segmental arteries on the vertebral bodies. Most of the segmental arteries passed the middle portion of the vertebral body (zones B and C). However, 51 of 738 segmental arteries (6.9%) had uncommon pathways (zones A and D), and segmental arteries from L2 to L4 had a higher incidence of uncommon pathways than higher level vertebrae (P < .05). We also observed 2 types of segmental artery anatomic variation, agenesis and dual supply. CONCLUSIONS: We suggest that spinal CT angiography can help to precisely visualize the spinal segmental arteries and surrounding bony structures and can aid clinicians in deciding on optimal approaches for spinal surgery.

[Functional review of drugstores in contraceptive distribution: Cheju area (author's transl)].

PIP: There are 3 different kinds of drugstores in Korea: drugstores with a licensed pharmacist, drugstores which are opened in the limited area and are not allowed to compound medicines (druggist), and drugstores which are opened in limited areas and are not authorized to compound medicines but are only allowed to sell a limited list of medicines (restricted drug dealer). There is no doubt that those pharmacists, druggists, and restricted drug dealers are functionally serving as health counselors to their community. Accordingly, they have a sort of potential leadership among the community people in the field on contraception. Both in functional and structural aspects, the drugstore is similar to other stores in that it is easily accessible. In fact, it is very easy to meet pharmacists to ask for health consultations while it is very difficult to request a physician's consultation without charge. A survey of drugstores in the Cheju area was carried out to review their up-to-date functional status for contraceptive distribution. Interviews were conducted by trained surveyors with 83 pharmacists, 27 druggists, and 18 restricted drug dealers in September 1978 (seen in tabular form). 39% of the respondents felt that contraceptive councelling was difficult because of a lack of knowledge, 71.9% felt that they needed training, while 68.8% were willing to participate in a family planning training course if it were arranged for them (in tabular form). Their interest in contraceptive distribution activities should be considered in future developments of Korean family planning programs. 3 kinds of contraceptives are dealt with in more than 74.8% of the drugstores while 7.9% of the drugstores did not deal with contraceptives. No drugstore in Cheju City did not deal with contraceptives; however 16.7% in Buk-gun and 29.2% in Nam-gun did not. The total number of contraceptive users through drugstores is estimated at 3456 or an average of 36 in each drugstore in the Cheju-do area. As shown in tabular form, the monthly average sale of contraceptives between January and August 1978 is 5277 cycles of orals, 1979 dozen condoms, 1040 tubes of spermicide, and 126 vials of injectables. (Author's modified)^ieng

[A study on family pattern and psychological aspects of parent and child].

PIP: This study reviews the relationship between family patterns and psychological aspects of the mother-child relationship. As the population increase in Korea will reach 50 million in 2020, population policy must deal with population quality. The data come from 118 5th and 6th grade students and their mothers. Survey results shows that the number of children and the family type are related to mothers' child rearing attitudes. Mothers in nuclear families tended to be warmer and freer towards their children than others. Family type was not related to the self-esteem of children, and the number of siblings showed a weak relationship. Children with siblings have stronger self-esteem. Birth order and younger sibling spacing had a stronger relationship with self-esteem. First borns and those who had younger siblings within a 2-year interval had the weakest self-esteem. Since families are becoming smaller, child quality is becoming more important. Not only family size but also family type, birth order, and spacing need to be considered for the psychological well-being of the population.^ieng

[A study on the influentials of knowledge gap].

PIP: This study investigates the influence of structural and functional characteristics on the knowledge gap of family planning and sex information in unmarried female workers. In explaining the knoledge gap, structural variables, such as age, education, and economic status, as well as functional variables, such as salience, the are regarded as independent variables, while seeking exposure to related information is regarded as a mediating variable. Using 1983 data collected by the Korea Instituted for Population and Health for a study on knowledge and attitudes on population and sex among unmarried female workers, the topics of family planning and sex informaton are discussed. Results show that age, education, salience, and seeking exposure have significant effects on the difference of group means on family planning and sex knowledge; only economic variables show no relations at all. A multiple regression analysis, using a path model, shows that education and salience explain 32% of the variance in seeking exposure. In explaining reproductive physiological knowledge, exposure explains 29% of the variance, while education explains 4%. Salience and age do not explain anything. In contraceptive knowledge seeking exposure explains 26% of the variance, followed by salience at 5%. The knowledge gap on physiology forms structurally, while the knowledge gap on contraceptive use forms functionally. Overall, education and salience determine seeking exposure level, and this affects the knowledge level. Therefore, family planning and sex education through schools or institutional education must be strengthened; before the unmarried female worker becomes too involved in the opposite sex, enough information to have a healthy social life must be learned.^ieng

Implication for student's sex education in Korea.

PIP: General information on junior and senior high school students' sexuality is presented so that attention can be called to their sex-related problems. A questionnaire was used with 2nd year students of middle and high school in Seoul in June, 1987. 1427 were middle school students; 1774 high school students were interviewed. There were 51.5% boys for the middle-school survey and 50.8% for the high-school one. High-school students were more permissive than those in middle school about smoking, drinking, going to discotheques, and watching sex videos; but not about taking drugs. 90% of all student thought that taking drugs was unacceptable. 33.5% of the high school students thought that hugging and kissing was not acceptable on dates, as opposed to 64.6% of the middle-school students. Students' attitudes toward masturbation are given in table form. 48.6% of middle school students disapprove of premarital sex; 37.7% of high school boys approved. 85.2% of the high- school students thought that unmarried people should be taught contraception. Boys preferred condoms; girls preferred the pill. Smoking and drinking experiences among Korean teenagers are discussed. 58.3% of middle school boys had "sexually stimulated experiences," as had 93.9% of high-school boys. 34% of middle-school girls and 40.6% of high-school girls had had "sexual stimulation." Boy-girl differences in sexually stimulated feelings is discussed. Aside from masturbation, sexual sublimation took the form of listening to music or exercising. Students experiences in opposite-sex relationships are discussed, as are students' sexual intercourse experience. 39.1% of the boys and 18.9% of the girls used contraception. The majority of the students do not have the necessary sex information. Their level of understanding of sex- related terminology was very low. Sex booklets, peers, and teachers were the 1st 3 knowledge sources. Factor analysis was done on 10 sexual behavior variables for middle-school students. 14 variables made up the factor analysis of high-school students' sexual behavior. A school sex education program should be developed.^ieng

[Evaluation of integrated health workers training of basic course (author's transl)].

PIP: Integrated training of field workers was initiated in 1978, with a week training course in family planning, maternal and child health, and tuberculosis control. This course provided orientation. In 1979, a 2 week course actually preparing workers for their field activities was inaugurated. Data collected from 182 field workers who attended the course in 1979 are analyzed here. Mean age of workers was 23.6, 3.4 years lower than a 1971 survey revealed. All workers were licensed, while in 1971 39% were without licenses. 32.8% were dissatisfied with their current job (51.8% among maternal and child health workers). Improved pay and working environment is urgently needed. Most workers were satisfied with the 2 week course and responded favorably to the lecturers, although a few wished to have more contact with the training staff. Audiovisual materials were considered adequate but could be improved. Printed materials were generally well accepted. Practice and demonstration sessions were shown to be effective, while case study and field observation were not; improvement is needed in these areas. The trainees were generally enthusiastic about the program and hopeful about their contributions to integration. More time for study and review was urged, and a continuous effort at curriculum development and operational improvement of the training program is needed. (Author's modified)^ieng

Analysis of factors contributing to fertility decline in Korea.

With the successful Korean national family planning program and rapid socioeconomic advancement since 1962, the contraceptive prevalence rate has risen from 9% in 1964 to 79% in 1991, with the corresponding total fertility rate (TFR) going from 6.0 in 1960 to 1.6 in 1988, which is considerably below the replacement fertility rate. The main purpose of this study is, therefore, to identify the structural and causal factors that contributed to the fall in fertility over the last 3 decades, in an effort to formulate future population policy directions and strategies. The 2 methods used for the study were: the standardization approach to examine the structural factors on fertility decline, and the bongaarts model to measure the effects of the proximate variables in the fertility decline. The study indicated that the fall in the crude birth rate and the general fertility rate for the periods of 1960-70 and 1980-90 were largely influenced by the decline in marital fertility which was triggered by the national family planning program initiated in 1962. The analysis based on the bongaarts model revealed that the 3 principal factors which exercised a strong influence on the fertility decline were the rise in age at marriage, the increase in induced abortion, and the increase in contraceptive use, but the influence of induced abortion has been decreasing in recent years. In general, the study results suggest that the main concerns of the national family planning program should be shifted from the past quantitative approach with emphasis on fertility reduction to a qualitative approach which stresses maternal and child health and other public health programs.

Effects of induced abortion and son preference on the imbalance of sex ratio in Korea.

PIP: "This study examines the trend and determinants of pregnancy outcomes in [South] Korea during the period from the early 1960s to the early 1990s using data from a retrospective survey of pregnancies. First, pregnancy outcomes are compared between the subsamples which are divided by the year of pregnancy and by the number of existing children. Within each subsample, comparisons are also made according to premarital pregnancy, sex composition of existing children, women's education level and the place of residence. The following section focuses on the pregnancy outcomes by the contraceptive methods used when one became pregnant. Finally, selective abortions and their implications [for] fertility and the sex ratio are discussed." (EXCERPT)^ieng

[Characteristics of government program IUD, sterilization and menstrual regulation acceptors in Cheju Province. (author's transl)].

PIP: This study represents the results of a coupon analysis of government contraceptive programs and menstrual regulation acceptors in Cheju province. Analysis of coupons for this study was limited to those collected during the period January-March 1978; the total number collected and analyzed for this study was 1075. Of these, 646 were for 1st IUD insertion, 128 for IUD reinsertion, 134 for vasectomy, 588 for tubal ligation, and 579 for (MR) menstrual regulation. The coupons reveal that the educational level of wives is comparatively lower than that of all eligible Cheju women. Modal age of wives is 25-34 for the IUD, 30-4 for vasectomy, and 30-9 for tubal ligation acceptors. The mean number of living children is 3.85 for tubal ligation acceptors, 3.07 for IUD acceptors, and 2.96 for vasectomy acceptors. A similar trend is revealed in the number of living sons; 2.2 for tubal ligation acceptors, 1.5 for new IUD acceptors (1st insertion), and 1.7 for both IUD acceptors (for reinsertion) and vasectomy acceptors. In Cheju-do, MR is 2nd in popularity only to tubal ligation in terms of number of coupons collected. The total yearly target of 600 cases in 1978 was 97% (570 cases) achieved during the 1st quarter. Of special concern to the study was the amount of immediate postabortal contraceptive acceptance occurring in the province. The coupons indicate that 70% of all aborters accept immediate postabortal contraception. Tubal ligation proved the most popular (254 acceptors), followed by IUD 1st insertion (119 acceptors), and IUD reinsertion (33 acceptors). Postabortal contraceptive acceptance rates vary by area. 74% of MR acceptors in Nam-gun accepted contraception, 66% of Cheju City did so, and 55% in Buk-gun became immediate contraceptive acceptors. Most post-MR contraceptive acceptors had only a primary school background. IUD acceptors had less education than did the average post-MR contraceptive acceptor while tubal ligation acceptors had more. The age of post-MR also varied by method selected. Younger women selected the IUD and older women selected sterilization. Most post-MR contraceptive acceptors had at least 1 living son. However, 12-4% of IUD acceptors had no son. All tubal ligation acceptors had at least 1 son. The study results indicate that MR procedures performed by designated doctors or clinics will result in high levels of contraceptive acceptance, especially for tubal ligation. Therefore, it is recommended that the government increase its support of MR to meet their goal of expanding contraceptive use. (Author's modified)^ieng

[The effect of patient teaching on compliance with sick role behavior of diabetic patients].

This study examined the effect of patient teaching on Compliance with sick role behavior in diabetic patients. The purpose was to improve diabetic patients Compliance by D.M. patient teaching. The study objectives were to determine the effect of patient teaching on Compliance with sick role behavior, and factors influencing compliance with sick role behavior of diabetic patients. The subjects, consisting of 52 diabetic patients diagnosed in the C. and other hospitals in K. city were divided into experimental and control groups. Data were gathered from July 25th to September 3rd, 1988 through interviews by questionnaires, measurement of blood sugar level by Reflux. D.M. Patient teaching was defined as informational intervention of social support by the nurse. A booklet representing patient education and questionnaires were developed by the investigator, and were tested for Content validity, and reliability by Item Analysis: Cronbachs alpha for any instrument to measure variables was patient Compliance .83, perceived health belief .65, diabetic knowledge .70. Analysis of data were done by paired t-test, t-test, Anova, Pearson correlation, and Stepwise multiple regression. The results of the study may be summarized as follows: 1. The effect of patient teaching on Compliance with sick role behavior, on diabetic Knowledge and health belief was Confirmed by significant differences between the experimental and the control group before and after the experiments. (P = 000 P = 006, P = 004).(ABSTRACT TRUNCATED AT 250 WORDS)

Growth-associated synthesis of recombinant human glucagon and human growth hormone in high-cell-density cultures of Escherichia coli.

Synthesis of two recombinant proteins (human glucagon and human growth hormone) was investigated in fed-batch cultures at high cell concentrations of recombinant Escherichia coli. The glucose-limited growth was achieved without accumulation of metabolic by-products and hence the cellular environment is presumed invariable during growth and recombinant protein synthesis. Via exponential feeding in the two-phase fed-batch operation, the specific cell growth rate was successfully controlled at the desired rates and the fed-batch mode employed is considered appropriate for examining the correlation between the specific growth rate and the efficiency of recombinant product formation in the recombinant E. coli strains. The two recombinant proteins were expressed as fusion proteins and the concentration in the culture broth was increased to 15 g fusion growth hormone 1(-1) and 7 g fusion glucagon 1(-1). The fusion growth hormone was initially expressed as soluble protein but seemed to be gradually aggregated into inclusion bodies as the expression level increased, whereas the synthesized fusion glucagon existed as a cytoplasmic soluble protein during the whole induction period. The stressful conditions of cultivation employed (i.e., high-cell-density cultivation at low growth rate) may induce the increased production of various host-derived chaperones and thereby enhance the folding efficiency of synthesized heterologous proteins. The synthesis of the recombinant fusion proteins was strongly growth-dependent and more efficient at a higher specific growth rate. The mechanism linking specific growth rate with recombinant protein productivity is likely to be related to the change in cellular ribosomal content.

Community based distribution programs: description and findings.

PIP: Currently, there are 4 Community Based Distribution Projects (CBDs) in Korea operating in diverse settings, using different delivery systems and testing disparate hypotheses. CBDs aim to maximize access of low income people to family planning by training community people to act as distributors; offering services and supplies free or at nominal charge; eliminating or reducing paperwork, procedures and waiting time at clinic projects; and increasing public awareness and knowledge of available family planning services. 4 CBD projects in current operation are: the Korean Population Policy and Program Evaluation Study; the CBD of Contraceptive Pilot Project; The Alternative Delivery System Project Utilizing Tong and Ban Chiefs; and the Women's Church Organization Delivery Project. Each project is briefly described in this paper, as are the strengths and weaknesses of each. From the findings, policy and administrative implications were drawn: 1) female sterilization would raise contraceptive prevalence rates to estimated saturation level; 2) a big market exists for high quality pills and condoms attractively packaged and priced; 3) red tape hampers contraceptive acceptance in Korea and record-keeping is a serious problem in CBD programs; 4) another serious program problem is the low morale of distributors; 5) paying distributors to maintain their participation in the program does not seem necessary; 6) due to high turnover rates among fieldworkers, it is difficult to supervise adequately CBD distributors; 7) due to the nature of Korean urban environment, it seems impractical to use the door to door approach of canvassing followed by a switch to depot resupply. To meet service needs of increasing number of eligible women in the '80's, establishment of a large scale network of volunteer family planning and health auxillaries is recommended.^ieng

Phytoremediation of MTBE from a groundwater plume.

The feasibility of phytoremediation to both remediate and hydraulically contain a methyl tert-butyl ether (MTBE)-contaminated groundwater plume was investigated in a three-phase study that included the following elements: (i) a laboratory bioreactor study that examined the fate and transport of 14C-radiolabeled MTBE in hybrid poplar trees, (ii) a novel approach for a mathematical modeling study that investigated the influence of deep-rooted trees on unsaturated and saturated groundwater flow, and (iii) a field study at a Houston site with MTBE-contaminated groundwater where hybrid poplar trees were planted. In the laboratory study, the predominant fate pathway was uptake and evapotranspiration of [14C]-MTBE from leaves and stems of poplar cuttings rooted in hydroponic solution. The modeling study demonstrates that phytohydraulic containment of MTBE in groundwater by deep-rooted trees can be achieved. The field study demonstrated significant groundwater uptake of groundwater by deep-rooted trees via direct measurement in the first three seasons. The use of vegetation may provide a cost-effective in-situ alternative for containment and remediation of MTBE-contaminated groundwater plumes.