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Morgan M, Saba S, Gower W. Fibronectin influences cellular proliferation and apoptosis similarly in LNCaP and PC-3 prostate cancer cell lines. Urol Oncol 2000; 5:155-159. [PMID: 10869957 DOI: 10.1016/s1078-1439(99)00058-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The mechanisms responsible for the emergence of clinically advanced prostate cancer (PC) are incompletely understood. Recent studies suggest that altered tumoral apoptosis with disordered cell proliferation sustains advanced disease and may account for the phenomena of anti-androgen therapeutic resistance. Previous inquiry has focused primarily on faulty intracellular mechanisms with limited scrutiny of the extracellular matrix including fibronectin and collagen type 4. We evaluated cell proliferation with Ki-67 immunoassay/image analysis and apoptosis by TUNEL staining and Bcl-2 immunoassay/image analysis in LNCaP and PC-3 human PC cell lines at baseline and following propagation on fibronectin and collagen type 4-coated coverslip substrate. Cell cultures showed differing proliferative and apoptosis characteristics at baseline, with the LNCaP cell line showing relatively higher proliferation and apoptosis rates than the PC-3 cell line. Cell proliferation and apoptosis were statistically significantly decreased in both cell lines following propagation on fibronectin. Bcl-2 expression was significantly increased among both cell lines following propagation on fibronectin. In contrast, cell proliferation, apoptosis, and Bcl-2 expression showed insignificant changes in both cell lines following uncoated coverslip and collagen type 4 matrix propagation. Our findings showed that fibronectin influences cell proliferation, apoptosis, and Bcl-2 expression similarly among LNCaP and PC-3 PC cell lines. It is likely that the altered rates are independent of the androgen status of the cell line and are mediated through a nonhormonal mechanism.
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Greenacre J, Morgan M, Tucker D. Health effects of landfill sites. Analyses require high quality data. BMJ (CLINICAL RESEARCH ED.) 2000; 320:1542. [PMID: 10877587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
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Ryder RW, Batter V, Kaseka N, Behets F, Sequeira D, M'Boly E, Kanda M, Tshibambe M, Morgan M. Effect of HIV-1 infection on tuberculosis and fertility in a large workforce in Kinshasa, Democratic Republic of the Congo. AIDS Patient Care STDS 2000; 14:297-304. [PMID: 10897501 DOI: 10.1089/10872910050046313] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
To determine the effect of an HIV counseling service on the incidence of HIV and tuberculosis infection and on the fertility rate in a large workforce cohort of adult men and women from Kinshasa, Democratic Republic of Congo (formerly Zaire), we conducted a 2-year prospective longitudinal cohort study, two large Kinshasa businesses (a commercial bank and a textile factory). We determined baseline HIV-1 seroprevalence, HIV-1 and tuberculosis mortality/morbidity, and fertility rates during 24 months of follow-up on 8866 employees and 6411 wives of male employees. The baseline HIV-1 seroprevalence was 2.8% in male employees (n = 6657), 8.4% in female employees (n = 417), and 2.4% in the wives of male employees (n = 4692). The HIV-1 seroincidence per 100 person-years of follow-up in these three groups was 0.9, 0.5 and 0.8, respectively. The incidence of tuberculosis was 2.4/100 person years in persistently seropositive individuals compared with a 0.38 rate in persistently seronegative individuals (p < 0.01). The annual fertility rate in persistently seronegative women was 250.0/1000 women compared with a rate of 140/1000 in persistently seropositive women (p < 0.001). Forty-eight (44%) of 105 male employees and 17 (26%) of 60 wives of male workers who died during follow-up were HIV-1 seropositive. HIV infection was responsible for nearly one half of all deaths in this large workforce. Tuberculosis incidence was six times higher in HIV-1-infected compared with uninfected individuals. Counseling of HIV-infected women and their husbands appeared to be effective as their cumulative fertility rate was 44% lower than the rate in similarly aged uninfected women.
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Evans SM, Hahn S, Pook DR, Jenkins WT, Chalian AA, Zhang P, Stevens C, Weber R, Weinstein G, Benjamin I, Mirza N, Morgan M, Rubin S, McKenna WG, Lord EM, Koch CJ. Detection of hypoxia in human squamous cell carcinoma by EF5 binding. Cancer Res 2000; 60:2018-24. [PMID: 10766193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Localization and quantitation of 2-nitroimidazole drug binding in low pO2 tumors is a technique that can allow the assessment of hypoxia as a predictive assay. EF5 [2-(2-nitro-1H-imidazol-1-yl)-N-(2,2,3,3,3-pentafluoropropyl) acetamide] is such a drug, and it has been shown to be predictive of radiation response in rodent tumors. Using fluorescence immunohistochemical techniques, we provide data on the presence, distribution, and levels of EF5 binding as a surrogate for hypoxia in human head and neck and uterine cervix squamous cell cancers (SCCs). Six patients with SCC were studied. Four patients had head and neck tumors, and two had uterine cervix cancers. The incubation of fresh tissue cubes in EF3 under hypoxic conditions ("reference binding") demonstrated that all tumors were capable of binding drug, and that this binding varied by a factor of 2.9-fold (174.5-516.1) on an absolute fluorescence scale. In the five patients treated at the lowest drug doses (9 mg/kg), in situ binding was quantitatable. For all six patients, the maximum rate of in situ binding varied by a factor of 6.7 between the lowest and highest binding tumor (24.8-160.3) on an absolute fluorescence scale. In tumors with high binding regions, intratumoral heterogeneity was large, extending from minimal fluorescence (<1%) up to 88.6% of reference binding. In tumors with minimal binding, there was little intratumoral heterogeneity. These studies demonstrate substantial heterogeneity of in situ binding between and within individual squamous cell tumors.
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Abstract
BACKGROUND New heavy-body (packable) composites have been developed for use in posterior direct resin restorations. These materials are promoted as having better handling characteristics and higher physical properties than previous microhybrid composites. METHODS The authors describe an incremental layering technique that takes advantage of the improved handling characteristics and proposed reduced shrinkage and greater depth of cure. CLINICAL IMPLICATIONS When this new technique is used with one-bottle adhesives and improved instrumentation, posterior heavy-body composites can be placed faster, easier and possibly more predictably than when medium-body resins and previous techniques are used.
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Morgan M, Evans-Williams D, Salmon R, Hosein I, Looker DN, Howard A. The population impact of MRSA in a country: the national survey of MRSA in Wales, 1997. J Hosp Infect 2000; 44:227-39. [PMID: 10706807 DOI: 10.1053/jhin.1999.0695] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Continuous data collection on all new isolates of MRSA via CoSurv has taken place in Wales since January 1996. In order to audit this data collection, and to address some of the issues that it does not include, a survey of MRSA was carried out. Questionnaires were completed by infection control teams. Rates were calculated using hospital throughput denominators. Results from the one-day prevalence survey, the two-week incidence survey, and the follow-up survey carried out on new MRSA patients identified in the incidence survey, are presented. Results were found to be broadly similar to those collected via routine surveillance. MRSA was found frequently and disproportionately in the elderly, with higher rates in male than female patients. The highest incidence of total and invasive MRSA was in males aged 75 and over (total: 12.5/1000 finished consultant episodes; invasive: 2.8/1000). Although there was a large community reservoir of MRSA, most appeared to have been acquired in hospital, since most patients had a history of hospitalization, often with multiple hospital admissions. Community-based isolates from cases with no hospital history tended to have been from ulcers. Prevalence and incidence of MRSA was relatively low compared with hospital throughput (mean prevalence: 2.4/100 occupied beds; mean incidence: 3.6/1000 finished consultant episodes), there was also quite large variation between sites, even when screening samples were removed. Patients with MRSA had strikingly long stays before isolation of the organism (prevalence survey: 39 days; incidence survey: 31 days) and highest incidence occurred in elderly care wards. The outcome survey showed that approximately half of the patients were treated with some type of antimicrobial therapy for MRSA. Decontamination therapy was associated with clearance of MRSA only when controlling for sex of the patient. The majority of patients were discharged still with MRSA, mostly to their own homes. The survey emphasizes the need to continue surveillance to detect any changes, to allow guidelines based on evidence to be developed and to monitor the effectiveness of such guidelines.
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Ness RB, Grisso JA, Cottreau C, Klapper J, Vergona R, Wheeler JE, Morgan M, Schlesselman JJ. Factors related to inflammation of the ovarian epithelium and risk of ovarian cancer. Epidemiology 2000; 11:111-7. [PMID: 11021606 DOI: 10.1097/00001648-200003000-00006] [Citation(s) in RCA: 232] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Previous epidemiologic observations consistently suggest that suppression of ovulation, tubal ligation, and hysterectomy reduce the risk of ovarian cancer and that perineal talc use increases the risk. We examined these and other risk factors in the context of a new hypothesis: that inflammation may play a role in ovarian cancer risk. Ovulation entails ovarian epithelial inflammation; talc, endometriosis, cysts, and hyperthyroidism may be associated with inflammatory responses of the ovarian epithelium; gynecologic surgery may preclude irritants from reaching the ovaries via ascension from the lower genital tract. We evaluated these risk factors in a population-based case-control study. Cases 20-69 years of age with a recent diagnosis of epithelial ovarian cancer (767) were compared with community controls (1,367). We found that a number of reproductive and contraceptive factors that suppress ovulation, including gravidity, breast feeding, and oral contraception, reduced the risk of ovarian cancer. Environmental factors and medical conditions that increased risk included talc use, endometriosis, ovarian cysts, and hyperthyroidism. Gynecologic surgery including hysterectomy and tubal ligation were protective. Tubal ligation afforded a risk reduction even 20 or more years after the surgery. The spectrum of associations provides support for the hypothesis that inflammation may mediate ovarian cancer risk.
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Abstract
BACKGROUND Locum doctors provide cover during normal working hours for GPs absent due to holidays, sickness, maternity leave or for educational purposes. However, there is little information on the extent of the use of locums or of GPs' perception of their services. OBJECTIVES To examine the level of use of locum doctors by GPs, the ease of recruitment and satisfaction with their services. METHODS A postal survey of all general practices in one of the six health regions in England was carried out. Logistic regression analysis was used to examine the independent effects on locum use of practice size and type of area, source of recruitment and GPs' satisfaction with their services. RESULTS A total of 935 (80.6%) general practices responded. Locum GPs were employed by 81.7% of practices in the previous 12 months. Two-thirds of practices reported problems obtaining locum cover, especially at short notice and for holiday periods. One-fifth of practices employing a locum in the previous 12 months were dissatisfied with the locum. CONCLUSIONS There are high demands for, but a considerable shortage of, locum doctors in general practice. Educational and other initiatives for GPs may contribute to increased demands for locum cover. Difficulties in recruitment may be reduced by measures to improve the conditions of employment for doctors working as locums on a longer term basis. New codes of practice for employing locums may increase satisfaction with locum services.
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Schilder RJ, Blessing JA, Morgan M, Mangan CE, Rader JS. Evaluation of gemcitabine in patients with squamous cell carcinoma of the cervix: a Phase II study of the gynecologic oncology group. Gynecol Oncol 2000; 76:204-7. [PMID: 10637071 DOI: 10.1006/gyno.1999.5671] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
PURPOSE A multicenter Phase II trial was conducted to evaluate the activity and toxicity of gemcitabine in patients with previously treated squamous cell carcinoma of the uterine cervix. PATIENTS AND METHODS Patients were required to have measurable disease with adequate performance status, bone marrow, hepatic, and renal function. Histologic confirmation of the primary diagnosis as squamous cell cancer of the uterine cervix was mandatory. Patients were allowed one prior chemotherapy regimen, usually cisplatin-based. The initial dose of gemcitabine was 800 mg/m(2) weekly times three with 1 week off until progressive disease or adverse effects prohibited further therapy. Doses were escalated or reduced based on previous cycle toxicity. RESULTS Twenty-seven patients were entered into the trial. One patient never received the drug and 1 patient was inevaluable for response. A median of two cycles were administered to each patient (range: 1-7 cycles). The overall response rate (two partial responses) was 8% with 21% of patients having stable disease. The median progression-free interval was 1.9 months (range: 0.5-9.0) and overall survival was 4.9 months (range: 1.5-16.3). Two patients had grade 4 neutropenia; 1 patient had grade 4 anemia. The median WBC nadir in the 13 patients experiencing any leukopenia was 2300/microl (range: 400-3800). There was only one episode of grade 4 gastrointestinal toxicity. CONCLUSIONS Gemcitabine as a single agent demonstrated minimal antitumor activity in previously treated patients with squamous cell cancer of the uterine cervix. Since gemcitabine in the dose and schedule employed is known to potentiate the cytotoxicity of cisplatin and radiotherapy (the current standard therapies for this disease), further development of gemcitabine would only be indicated in combination with these treatment modalities.
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Morgan M. Measuring process and outcomes: professional compliance, professional opinions and patients' well-being. Fam Pract 2000; 17 Suppl 1:S21-5. [PMID: 10735264 DOI: 10.1093/fampra/17.suppl_1.s21] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
This paper examines how professional and patient behavioural variables are conceptualized, their application in relation to guideline implementation and the different methods that may be employed in their assessment. The type of guideline and the process of development of guidelines are shown to influence the choice of indicators, with important issues for the assessment of professional compliance being raised by the development of patient-centred guidelines which require that clinical management takes account of patients' beliefs and preferences. Methodological problems relating to the use of routine data as indicators of professional compliance are discussed. The differing roles and contributions of quantitative and qualitative research in the assessment of professional and patient opinions are also examined. The paper advocates the development of guides to good practice in the assessment of these behavioural variables rather than specifying a uniform approach, and identifies questions requiring further research, especially in relation to patients' evaluations and satisfaction.
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Morgan M. Dental laser identifies early stages of caries. DENTISTRY TODAY 2000; 19:30-3. [PMID: 15027284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
In conclusion, the various methods of caries detection used, including visual inspection, radiographs, and tactile sensation, have a significant subjective component. The Diagnodent allows clinicians to add a more objective test to their armamentarium. Should the doctor choose to "watch" a suspected lesion and treat with topical fluoride, the area can be monitored for the progression or regression of decalcification. For more information, call KaVo at (888) KaVo-USA.
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Morgan M, Stokes H. Comparison of vaginal misoprostol and gemeprost as pre-treatment in first trimester pregnancy interruption. BJOG 2000; 107:145-6. [PMID: 10645882 DOI: 10.1111/j.1471-0528.2000.tb11602.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Hardig TM, Brunsfeld SJ, Fritz RS, Morgan M, Orians CM. Morphological and molecular evidence for hybridization and introgression in a willow (Salix) hybrid zone. Mol Ecol 2000; 9:9-24. [PMID: 10652072 DOI: 10.1046/j.1365-294x.2000.00757.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Hybrid zones provide biologists with the opportunity to examine genetic and ecological interactions between differentiated populations. Accurate identification of hybrid genealogies is considered a necessary prerequisite to understanding observed patterns of hybridization-related phenomena. We analysed molecular and morphological data from individuals in a hybrid zone between two species of willows (Salix sericea Marshall and S. eriocephala Michaux) and report the use of randomly amplified polymorphic DNA (RAPD), chloroplast DNA (cpDNA), and ribosomal DNA (rDNA) markers, as well as vegetative morphology and foliar chemistry data to identify individuals in terms of hybrid genealogy and to infer the direction and extent of backcrossing and introgression within the hybrid zone. A novel version of a maximum likelihood estimate approach (developed for this study) was used to calculate hybrid index scores from RAPD marker data; this method produced results similar to those obtained using traditional arithmetic methods. Distribution of rDNA, cpDNA, and chemistry data were examined within the graphical context of RAPD-based hybrid index score histograms and principal component analyses (PCA) on RAPD and morphology data. Seven of the 21 plants classified as S. eriocephala in the field were possible introgressants. Another plant presented an unequivocal example of backcrossed S. sericea chemistry and RAPD markers. Inter- and intraspecific chloroplast diversity found within the hybrid zone suggests both historic introgression (perhaps in a glacial refugium), and contemporary hybridization. Patterns of inheritance and expression within the hybrid zone suggest that morphological characters are often not expressed in a simple additive fashion, and problems associated with both morphological and molecular data are considered.
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Koscielniak E, Harms D, Henze G, Jürgens H, Gadner H, Herbst M, Klingebiel T, Schmidt BF, Morgan M, Knietig R, Treuner J. Results of treatment for soft tissue sarcoma in childhood and adolescence: a final report of the German Cooperative Soft Tissue Sarcoma Study CWS-86. J Clin Oncol 1999; 17:3706-19. [PMID: 10577842 DOI: 10.1200/jco.1999.17.12.3706] [Citation(s) in RCA: 184] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE The goal of the second German Soft Tissue Sarcoma Study CWS-86 (1985 to 1990) was to improve the prognosis in children and adolescents with soft tissue sarcoma by means of a clinical trial comprising intensive chemotherapy and risk-adapted local therapy. PATIENTS AND METHODS There were 372 eligible patients. A staging system based on the postsurgical extent of disease was used. Chemotherapy consisted of vincristine, dactinomycin, doxorubicin, and ifosfamide. Radiotherapy was administered early at 10 to 13 weeks simultaneously with the second chemotherapy cycle (32 Gy or 54. 4 Gy). The single dose was reduced to 1.6 Gy and given twice daily (accelerated hyperfractionation). RESULTS The event-free survival (EFS) and overall survival rates at 5 years were 59% +/- 3% and 69% +/- 3%, respectively. The 5-year EFS rate according to stage was as follows: stage I, 83% +/- 5%; stage II, 69% +/- 6%; stage III, 57% +/- 4%; and stage IV, 19% +/- 6%. The outcome for patients with stage III disease who required radiotherapy was much better in the CWS-86 study compared with the CWS-81 study (5-year EFS, 60% +/- 5% v 44% +/- 6%; P =.053). The most common treatment failure was isolated local relapse, with 14% of patients relapsing at the primary tumor site. CONCLUSION The improved design of the study incorporating risk-adapted radiotherapy allowed treatment to be reduced for selected groups of patients without compromising survival.
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Abstract
Infection control teams are not alone in their need to manipulate data. How best can such manipulation be achieved and what tools are available to turn information into knowledge. The workshop included discussion and demonstration of some methods currently being used by infection control teams. While the workshop did not aim to produce all the answers, participants were able to question, discuss and learn new ways that they might take their own practice in the future.
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Markman M, Blessing JA, DeGeest K, Morgan M, Look KY, Herzog TJ, Rose PG. Lack of efficacy of 24-h infusional topotecan in platinum-refractory ovarian cancer: A Gynecologic Oncology Group trial. Gynecol Oncol 1999; 75:444-6. [PMID: 10600304 DOI: 10.1006/gyno.1999.5640] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND The aim of this study was to evaluate the efficacy of a more convenient topotecan administration schedule in the second-line treatment of advanced platinum-refractory ovarian cancer. METHODS AND MATERIALS The Gynecologic Oncology Group conducted a Phase II trial of 24-h infusional topotecan (8.5 mg/m(2)), repeated every 3 weeks in 26 patients with platinum-refractory ovarian cancer (failure to respond to initial platinum-based treatment or development of recurrent disease within 6 months of completion of chemotherapy). RESULTS Grade 4 neutropenia (85% of patients) and thrombocytopenia (12%) were the major toxicities encountered. Of the 25 patients evaluable for response, only a single patient experienced an objective response (4%). CONCLUSIONS When employed at this dose and schedule (24-h infusion every 3 weeks), topotecan has minimal second-line activity in platinum-refractory ovarian cancer.
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Bennett P, Lowe R, Mayfield T, Morgan M. Coping, mood and behaviour following myocardial infarction: Results of a pilot study. ACTA ACUST UNITED AC 1999. [DOI: 10.1016/s1362-3265(99)80044-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Ramanujam N, Long H, Rode M, Forouzan I, Morgan M, Chance B. Antepartum, transabdominal near infrared spectroscopy: feasibility of measuring photon migration through the fetal head in utero. THE JOURNAL OF MATERNAL-FETAL MEDICINE 1999; 8:275-88. [PMID: 10582862 DOI: 10.1002/(sici)1520-6661(199911/12)8:6<275::aid-mfm8>3.0.co;2-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE We report the feasibility of measuring photon migration through the fetal head in utero using antepartum, transabdominal, near infrared (NIR) spectroscopy. METHODS We developed a continuous wave (CW) spectrometer that incorporates a halogen light source, silicon photodetectors, and a differential processing circuit for antepartum, transabdominal, NIR spectroscopy. By placement of the light source and photodetector on the midline of the maternal abdomen above the fetal head at a separation (approximately 10 cm) large enough for the light to propagate through maternal and fetal tissues via multiple scattering events before being detected at the surface and the use of filtered illumination and detection at wavelengths (760 nm, 850 nm), which coincide with the absorption bands of oxygenated and deoxygenated hemoglobin in the NIR window, we performed studies to evaluate whether antepartum, transabdominal NIR spectroscopy can measure photon migration through the fetal head in utero. RESULTS The results demonstrate that the CW spectrometer we developed can be employed to make NIR measurements from the maternal abdomen at a 10 cm source-detector separation, with an excellent signal-to-noise ratio. Furthermore, a variety of antepartum, transabdominal NIR measurements that we performed on patients undergoing a routine nonstress test demonstrate the feasibility of measuring photon migration through the fetal head in utero. CONCLUSIONS Preliminary assessment of transabdominal NIR spectroscopy suggests that this technique can enable photon migration through the fetal head in utero. This is an important step towards the development of this technique for measuring and quantifying fetal cerebral blood oxygenation in utero.
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Frohlich J, Ogawa S, Morgan M, Burton L, Pfaff D. Hormones, genes and the structure of sexual arousal. Behav Brain Res 1999; 105:5-27. [PMID: 10553687 DOI: 10.1016/s0166-4328(99)00079-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Despite the inherent difficulty of connecting individual genes with integrated mammalian behaviors, it has been determined that a series of genes are turned on by estrogenic hormones acting in forebrain. Their products are, in turn, facilitatory for female reproductive behaviors such as lordosis. The causal routes by which two genes contribute to the control of lordosis behavior, the classical estrogen receptor gene (ER-alpha) and a thyroid hormone (TH) receptor gene (TR-beta), have been delineated. Beyond the mechanisms underlying the expression of concrete, specific natural behaviors, lies the question of sexual motivation. Required as an intervening variable to explain fluctuations in natural behaviors in the face of constant stimuli, motivational states have both general and specific features. Most theoretical and experimental approaches toward the general aspects of motivation have depended heavily on concepts of 'arousal.' Sexual arousal is likely to depend both on very general, broadly distributed neuronal influences and on specific affiliative and sexual tendencies. Is 'general arousal' a monolithic, undifferentiated process? In no way can a review at this time settle such issues, but the reasons behind six new experimental approaches to these questions are described.
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Sil AK, Alam S, Xin P, Ma L, Morgan M, Lebo CM, Woods MP, Hopper JE. The Gal3p-Gal80p-Gal4p transcription switch of yeast: Gal3p destabilizes the Gal80p-Gal4p complex in response to galactose and ATP. Mol Cell Biol 1999; 19:7828-40. [PMID: 10523671 PMCID: PMC84853 DOI: 10.1128/mcb.19.11.7828] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Gal3, Gal80, and Gal4 proteins of Saccharomyces cerevisiae comprise a signal transducer that governs the galactose-inducible Gal4p-mediated transcription activation of GAL regulon genes. In the absence of galactose, Gal80p binds to Gal4p and prohibits Gal4p from activating transcription, whereas in the presence of galactose, Gal3p binds to Gal80p and relieves its inhibition of Gal4p. We have found that immunoprecipitation of full-length Gal4p from yeast extracts coprecipitates less Gal80p in the presence than in the absence of Gal3p, galactose, and ATP. We have also found that retention of Gal80p by GSTG4AD (amino acids [aa] 768 to 881) is markedly reduced in the presence compared to the absence of Gal3p, galactose, and ATP. Consistent with these in vitro results, an in vivo two-hybrid genetic interaction between Gal80p and Gal4p (aa 768 to 881) was shown to be weaker in the presence than in the absence of Gal3p and galactose. These compiled results indicate that the binding of Gal3p to Gal80p results in destabilization of a Gal80p-Gal4p complex. The destabilization was markedly higher for complexes consisting of G4AD (aa 768 to 881) than for full-length Gal4p, suggesting that Gal80p relocated to a second site on full-length Gal4p. Congruent with the idea of a second site, we discovered a two-hybrid genetic interaction involving Gal80p and the region of Gal4p encompassing aa 225 to 797, a region of Gal4p linearly remote from the previously recognized Gal80p binding peptide within Gal4p aa 768 to 881.
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Tanaka D, Lin M, Powell D, Morgan M, Lipsitz L, Aulerich RJ, Bursian SJ. Effects of dark-rearing on triphenyl phosphate-induced neuropathy in the visual system of the developing European ferret (Mustela putorius furo). JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 1999; 58:215-231. [PMID: 10591489 DOI: 10.1080/009841099157304] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Results of a previous study in our lab (Tanaka et al., 1994) suggested that the onset of susceptibility to the organophosphorus compound triphenyl phosphite (TPP) in the developing ferret visual system might be closely related to eye opening and the onset of light stimulation. In order to explore this idea further, TPP was administered to ferret kits that had been raised for varying periods of time in total darkness to assess whether a delay in the onset of light stimulation to the visual system might also result in a delay in its susceptibility to TPP. Ferret kits were raised from birth either in total darkness or in open-sided sheds exposed to ambient light, injected subcutaneously with TPP (888 mg/kg body weight) at 5.5, 7.5, 9.5, or 21.5 wk of age, euthanized, and perfused transcardially with a 10% formalin-saline solution 4 d after injection. Brains were sectioned parasagittally at a thickness of 40 microm and subsequently processed with the Fink-Heimer silver impregnation technique to reveal the presence of degenerating axons and terminals, and with cresyl violet stain to delineate nuclear boundaries and cell soma morphology. Comparisons among degeneration patterns present in light-reared and dark-reared kits at the four ages examined revealed that the time of onset, extent, and density of TPP-induced axonal and terminal degeneration seen in the lateral geniculate nucleus and primary visual cortex did not differ significantly between light- and dark-reared groups, with the possible exception of dark-reared kits exposed to TPP at 7.5 wk of age. In addition, neurons in the primary visual cortex showed shrinkage and increased packing densities in kits exposed to TPP in both light and dark environments, as well as in dark-reared non-injected kits. The results of this study indicate that dark-rearing does not delay the onset or lessen the severity of TPP-induced axonal and terminal degeneration in the developing visual system of the ferret. Data suggest that light activation and stimulation of the retino-geniculo-striatal visual pathway is not a necessary prerequisite for the onset of visual system susceptibility to the axonopathic effects of triphenyl phosphite.
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Abstract
The etiology of the porokeratoses is unknown. Overexpression of the p53 tumor suppressor protein and disregulated cell cycle control have been pathogenically implicated. The p53 tumor suppressor gene product is regulated by mdm2 and both gene products influence cell cycle progression through the cyclin-dependent kinase inhibitor p21. Thirty-three cases of the various types of porokeratosis were immunohistochemically studied for p53, mdm2, and p21 proteins. Each of the cases showed increased p53 and decreased mdm2 and p21 expression within keratinocytes underlying cornoid lamella. This study confirms the previous findings of increased p53 staining and expands the potential roles of mdm2 and p21 in the pathogenesis of the porokeratoses.
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299
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Scheja L, Makowski L, Uysal KT, Wiesbrock SM, Shimshek DR, Meyers DS, Morgan M, Parker RA, Hotamisligil GS. Altered insulin secretion associated with reduced lipolytic efficiency in aP2-/- mice. Diabetes 1999; 48:1987-94. [PMID: 10512363 DOI: 10.2337/diabetes.48.10.1987] [Citation(s) in RCA: 151] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Recent studies have shown that genetic deficiency of the adipocyte fatty acid-binding protein (aP2) results in minor alterations of plasma lipids and adipocyte development but provides significant protection from dietary obesity-induced hyperinsulinemia and insulin resistance. To identify potential mechanisms responsible for this phenotype, we examined lipolysis and insulin secretion in aP2-/- mice. Beta-adrenergic stimulation resulted in a blunted rise of blood glycerol levels in aP2-/- compared with aP2+/+ mice, suggesting diminished lipolysis in aP2-/- adipocytes. Confirming this, primary adipocytes isolated from aP2-/- mice showed attenuated glycerol and free fatty acid (FFA) release in response to dibutyryl cAMP. The decreased lipolytic response seen in the aP2-/- mice was not associated with altered expression levels of hormone-sensitive lipase or perilipin. The acute insulin secretory response to beta-adrenergic stimulation was also profoundly suppressed in aP2-/- mice despite comparable total concentrations and only minor changes in the composition of systemic FFAs. To address whether levels of specific fatty acids are different in aP2-/- mice, the plasma FFA profile after beta-adrenergic stimulation was determined. Significant reduction in both stearic and cis-11-eicoseneic acids and an increase in palmitoleic acid were observed. The response of aP2-/- mice to other insulin secretagogues such as arginine and glyburide was similar to that of aP2+/+ mice, arguing against generally impaired function of pancreatic beta-cells. Finally, no aP2 expression was detected in isolated pancreatic islet cells. These results provide support for the existence of an adipo-pancreatic axis, the proper action of which relies on the presence of aP2. Consequently, aP2's role in the pathogenesis of type 2 diabetes might involve regulation of both hyperinsulinemia and insulin resistance through its impact on both lipolysis and insulin secretion.
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300
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Morgan M, Salmon R, Evans-Williams D, Hosein I, Looker DN. Resistance to methicillin in isolates of Staphylococcus aureus from blood and cerebrospinal fluid in Wales, 1993-1997. J Antimicrob Chemother 1999; 44:541-4. [PMID: 10588317 DOI: 10.1093/jac/44.4.541] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Surveillance data for organisms isolated from blood cultures and cerebrospinal fluid (CSF) specimens has been gathered electronically in Wales since 1993. Over this period the proportion of total reported organisms from blood cultures and CSF represented by methicillin-resistant staphylococci (MRSA) has risen steadily. This has corresponded to a rise in rates of methicillin resistance amongst Staphylococcus aureus isolated from blood cultures and CSF from 4 to 43%. In certain age/gender groups in 1997, more than 50% of isolates of S. aureus were resistant to methicillin, suggesting that a change in empirical treatment may be necessary for suspected staphylococcal sepsis.
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