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3.
Magn Reson Chem ; 54(7): 584-91, 2016 Jul.
Article in English | MEDLINE | ID: mdl-26845387

ABSTRACT

Fast and effective structural/compositional analysis on formulated systems represents one of the major challenges encountered in analytical science. (13) C-detected diffusion represents a promising tool to tackle the aforementioned challenges, particularly in industry. Toward exploring the generic applications of (13) C-detected diffusion, thermal convection induced by (1) H decoupling has been identified as a key factor that resulted in significantly reduced resolution in the diffusion dimension. Optimization of experimental parameters and utilization of double-stimulated echo-based pulse sequence both can effectively suppress the thermal convection caused by the (1) H decoupling, the success of which allows robust and generic applications of (13) C-detected diffusion to systems from mixtures of small molecules, polymer blends, and copolymers to actual complex formulated systems. The method is particularly powerful in differentiating small molecules from polymers, polymer blends from copolymers, and end-group analysis. Copyright © 2016 John Wiley & Sons, Ltd.

5.
Biomacromolecules ; 13(10): 3355-69, 2012 Oct 08.
Article in English | MEDLINE | ID: mdl-22994294

ABSTRACT

Cold, semidilute, aqueous solutions of methylcellulose (MC) are known to undergo thermoreversible gelation when warmed. This study focuses on two MC materials with much different gelation performance (gel temperature and hot gel modulus) even though they have similar metrics of their coarse-grained chemical structure (degree-of-methylether substitution and molecular weight distribution). Small-angle neutron scattering (SANS) experiments were conducted to probe the structure of the aqueous MC materials at pre- and postgel temperatures. One material (MC1, higher gel temperature) exhibited a single almost temperature-insensitive gel characteristic length scale (ζ(c) = 1090 ± 50 Å) at postgelation temperatures. This length scale is thought to be the gel blob size between network junctions. It also coincides with the length scale between entanglement sites measured with rheology studies at pregel temperatures. The other material (MC2, lower gel temperature) exhibited two distinct length scales at all temperatures. The larger length scale decreased as temperature increased. Its value (ζ(c1) = 1046 ± 19 Å) at the lowest pregel temperature was indistinguishable from that measured for MC1, and reached a limiting value (ζ(c1) = 450 ± 19 Å) at high temperature. The smaller length scale (ζ(c2) = 120 to 240 Å) increased slightly as temperature increased, but remained on the order of the chain persistence length (130 Å) measured at pregel temperatures. The smaller blob size (ζ(c1)) of MC2 suggests a higher bond energy or a stiffer connectivity between network junctions. Moreover, the number density of these blobs, at the same reduced temperature with respect to the gel temperature, is orders of magnitude higher for the MC2 gels. Presumably, the smaller gel length scale and higher number density lead to higher hot gel modulus for the low gel temperature material.


Subject(s)
Methylcellulose/chemistry , Neutron Diffraction , Scattering, Small Angle , Gels/chemistry , Molecular Structure , Rheology , Temperature , Water/chemistry
6.
Curr Opin Obstet Gynecol ; 22(4): 344-53, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20611000

ABSTRACT

PURPOSE OF REVIEW: Intestinal endometriosis is commonly diagnosed in the setting of deeply infiltrating endometriosis. A multidisciplinary team that includes gynaecologists and general surgeons traditionally performs laparoscopic bowel resections for symptomatic patients. Recently, Pereira et al. has published the results of a series of patients who underwent laparoscopic bowel resection for endometriosis performed by a team of gynaecologic surgeons, after a period of experimental training with animals and joining participation with general surgeons in the first cases. It is suggested that gynaecologic surgeons may be able to perform laparoscopic bowel resections for endometriosis, if properly trained, although the results may not be reproducible. RECENT FINDINGS: A review of recent literature related to laparoscopic bowel resections for endometriosis showed that the learning curve and experience of the surgeon may be the most important predictive factors for the effectiveness of the procedure. Results concerning major operative complications and clinical remission were considered satisfactory in both single and multidisciplinary approaches, that is, laparoscopic bowel resections performed by gynaecologic and colorectal surgeons. Protective colostomies or ileostomies could not reduce the rate of rectovaginal fistulae in multidisciplinary experiences. SUMMARY: The single-surgeon model approach in laparoscopic excision of endometriosis that includes bowel resection may provide advantages for both the patients and healthcare system. The best model should be decided on the maximum benefit of the patient.


Subject(s)
Colonic Diseases/surgery , Digestive System Surgical Procedures/methods , Endometriosis/surgery , Laparoscopy/methods , Clinical Competence , Colonic Diseases/etiology , Endometriosis/complications , Feasibility Studies , Female , Gynecologic Surgical Procedures/methods , Humans
7.
J Magn Reson ; 200(2): 328-33, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19665405

ABSTRACT

Recently, a high temperature 10 mm cryoprobe was developed. This probe provides a significant sensitivity enhancement for (13)C NMR of polyolefins at a sample temperature of 120-135 degrees C, as compared to conventional probes. This greatly increases the speed of NMR studies of comonomer content, sequence distribution, stereo- and regioerrors, saturated chain end, unsaturation, and diffusion of polymers. In this contribution, we first compare the (13)C NMR sensitivity of this probe with conventional probes. Then, we demonstrate one of the advantages of this probe in its ability to perform 2D Incredible Natural Abundance Double Quantum Transfer Experiment (2D INADEQUATE) in a relatively short period of time. The 2D INADEQUATE has been rarely used for polymer studies because of its inherently very low sensitivity. It becomes even more challenging for studying infrequent polyolefin microstructures, as low probability microstructures represent a small fraction of carbons in the sample. Here, the 2D INADEQUATE experiment was used to assign the (13)C NMR peaks of 2,1-insertion regioerrors in a poly(propylene-co-1-octene) copolymer.


Subject(s)
Magnetic Resonance Spectroscopy/instrumentation , Polyenes/analysis , Polyenes/chemistry , Transducers , Carbon Isotopes/analysis , Carbon Isotopes/chemistry , Cold Temperature , Equipment Design , Sensitivity and Specificity , Temperature
8.
J Clin Endocrinol Metab ; 94(2): 623-31, 2009 Feb.
Article in English | MEDLINE | ID: mdl-19001523

ABSTRACT

CONTEXT: Products of at least five specific steroidogenic genes, including steroidogenic acute regulatory protein (StAR), which facilitates the entry of cytosolic cholesterol into the mitochondrion, side chain cleavage P450 enzyme, 3beta-hydroxysteroid-dehydrogenase-2, 17-hydroxylase/17-20-lyase, and aromatase, which catalyzes the final step, are necessary for the conversion of cholesterol to estrogen. Expression and biological activity of StAR and aromatase were previously demonstrated in endometriosis but not in normal endometrium. Prostaglandin E2 (PGE2) induces aromatase expression via the transcriptional factor steroidogenic factor-1 (SF1) in endometriosis, which is opposed by chicken-ovalbumin upstream-transcription factor (COUP-TF) and Wilms' tumor-1 (WT1) in endometrium. OBJECTIVE: The aim of the study was to demonstrate a complete steroidogenic pathway leading to estrogen biosynthesis in endometriotic cells and the transcriptional mechanisms that regulate basal and PGE2-stimulated estrogen production in endometriotic cells and endometrium. RESULTS: Compared with normal endometrial tissues, mRNA levels of StAR, side chain cleavage P450, 3beta-hydroxysteroid-dehydrogenase-2, 17-hydroxylase/17-20-lyase, aromatase, and SF1 were significantly higher in endometriotic tissues. PGE2 induced the expression of all steroidogenic genes; production of progesterone, estrone, and estradiol; and StAR promoter activity in endometriotic cells. Overexpression of SF1 induced, whereas COUP-TFII or WT1 suppressed, StAR promoter activity. PGE2 induced coordinate binding of SF1 to StAR and aromatase promoters but decreased COUP-TFII binding in endometriotic cells. COUP-TFII or WT1 binding to both promoters was significantly higher in endometrial compared with endometriotic cells. CONCLUSION: Endometriotic cells contain the full complement of steroidogenic genes for de novo synthesis of estradiol from cholesterol, which is stimulated by PGE2 via enhanced binding of SF1 to promoters of StAR and aromatase genes in a synchronous fashion.


Subject(s)
Dinoprostone/pharmacology , Endometriosis/genetics , Estradiol/biosynthesis , Gene Expression Regulation, Enzymologic , Ovarian Diseases/genetics , Steroidogenic Factor 1/physiology , Adult , Cells, Cultured , Cytochrome P-450 Enzyme System/genetics , Cytochrome P-450 Enzyme System/metabolism , Endometriosis/enzymology , Endometriosis/metabolism , Endometrium/drug effects , Endometrium/metabolism , Female , Gene Expression Regulation, Enzymologic/drug effects , Humans , Middle Aged , Ovarian Diseases/enzymology , Ovarian Diseases/metabolism , Phosphoproteins/genetics , Phosphoproteins/metabolism , Progesterone/biosynthesis , Promoter Regions, Genetic/drug effects , Transcription, Genetic/drug effects , Young Adult
9.
J Magn Reson ; 187(2): 225-33, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17524686

ABSTRACT

(13)C NMR is a powerful analytical tool for characterizing polyethylene copolymer composition and sequence distribution. Accurate characterization of the composition and sequence distribution is critical for researchers in industry and academia. Some common composite pulse decoupling (CPD) sequences used in polyethylene copolymer (13)C NMR can lead to artifacts such as modulations of the decoupled (13)C NMR signals (decoupling sidebands) resulting in systematic errors in quantitative analysis. A new CPD method was developed, which suppresses decoupling sidebands below the limit of detection (less than 1:40,000 compared to the intensity of the decoupled signal). This new CPD sequence consists of an improved Waltz-16 CPD, implemented as a bilevel method. Compared with other conventional CPD programs this new decoupling method produced the cleanest (13)C NMR spectra for polyethylene copolymer composition and triad sequence distribution analyses.

14.
J Reprod Med ; 50(10): 745-58, 2005 Oct.
Article in English | MEDLINE | ID: mdl-16320555

ABSTRACT

OBJECTIVE: To determine the prevalence of chronic inflammation of the pelvic peritoneum, systemic inflammation and autoimmunity in chronic pelvic pain and to explore the significance of these findings and assess the response to treatment with immune modification. STUDY DESIGN: Prospective, observational clinical studies from 2 centers were performed on 3,238 women presenting with pelvic pain to determine the prevalence of chronic inflammation by biopsy when endometriosis was absent. A second study included 40 women with chronic pelvic pain not resulting from endometriosis; immunologic investigations were carried out and therapy instituted. RESULTS: Chronic inflammation of the peritoneum, while not evident in the absence of pelvic pain, was present in 15.7% of women with chronic pelvic pain. In the second group, 10% had histologic evidence of chronic inflammation, 55% demonstrated evidence of systemic inflammation, and 37.5% were found to have autoimmune disorders. Chronic inflammation of the vagina was found in 42.5% and polycystic ovary syndrome in 22% of those with systemic inflammation. Twelve of the 40 were subsequently treated, with considerable success, with immune-modifying drugs, hydroxychloroquine and methotrexate. CONCLUSION: Chronic pelvic pain is frequently associated with systemic inflammation, including autoimmune diseases. Peritoneal chronic inflammation is sometimes also associated. It is often successfully treated with immune-modifying drugs.


Subject(s)
Antirheumatic Agents/therapeutic use , Autoimmune Diseases/complications , Pelvic Pain/immunology , Adolescent , Adult , Autoantibodies/immunology , Autoimmune Diseases/immunology , Autoimmunity/immunology , Chronic Disease , Female , Humans , Inflammation/immunology , Middle Aged , Pelvic Pain/drug therapy , Peritoneum/immunology , Prospective Studies
16.
Am J Obstet Gynecol ; 189(1): 306; author reply 306-7, 2003 Jul.
Article in English | MEDLINE | ID: mdl-12861181
17.
Gynecol Obstet Invest ; 55(2): 63-7, 2003.
Article in English | MEDLINE | ID: mdl-12771451

ABSTRACT

Endometriosis can have very subtle visual appearances. All theories of origin imply some early and presumably tiny form of the disease which potentially cannot be detected by the unaided human eye. A review of the literature indicates that with increasing magnification at surgery, virtually all endometriosis can be visualized. Invisible microscopic endometriosis is an unproven entity which retards intellectual progress in the study of this disease.


Subject(s)
Endometriosis/pathology , Biopsy , Endometriosis/etiology , Female , Humans , Laparoscopy , Peritoneal Diseases/pathology , Peritoneum/pathology
18.
Fertil Steril ; 78(4): 686-93, 2002 Oct.
Article in English | MEDLINE | ID: mdl-12372441

ABSTRACT

OBJECTIVE: Sampson's theory of reflux menstruation suggests that endometriosis is one form of a condition known as an autotransplant. This study seeks to characterize autotransplants as they are described in the literature and to determine whether endometriosis resembles an autotransplant. DESIGN: Literature review of published studies containing the following types of information: [1] characterization of the histologic features, immunohistochemistry, or structural function of autotransplants; and [2] comparisons of endometriosis with endometrium. MAIN OUTCOME MEASURE(S): Characteristics of multiple types of autotransplants were noted. Similarity or dissimilarity of endometriosis and endometrium was tabulated to judge qualitatively whether the bulk of the evidence supports the notion that endometriosis is an autotransplant. RESULT(S): Autotransplants remain very similar or identical to eutopic tissues of origin, regardless of the length of time following autotransplantation. Endometriosis differs in many profound and fundamental ways from eutopic endometrium, including clonality of origin, enzymatic activity, protein expression, and histologic and morphologic characteristics. A minority of studies has found similarities between endometriosis and eutopic endometrium. CONCLUSION(S): Endometriosis is dissimilar to eutopic endometrium and therefore lacks characteristics of an autotransplant. Sampson's theory of origin of endometriosis is not supported by the results of this study. Studies of experimental endometriosis that have not used menstrual endometrium may be misleading.


Subject(s)
Endometriosis/etiology , Animals , Endometriosis/pathology , Endometrium/pathology , Endometrium/transplantation , Female , Humans , Menstruation , Menstruation Disturbances , Transplantation, Autologous , Transplantation, Heterologous
19.
Fertil Steril ; 77(2): 288-96, 2002 Feb.
Article in English | MEDLINE | ID: mdl-11821085

ABSTRACT

OBJECTIVE: To describe symptoms, surgical diagnosis and treatment, and long-term outcome of patients with symptomatic diaphragmatic endometriosis. DESIGN: Observational follow-up study. SETTING: American tertiary referral center for the surgical treatment of endometriosis. PATIENT(S): Eight patients with diaphragmatic endometriosis causing severe or disabling symptoms. INTERVENTION(S): Laparoscopic diagnosis of diaphragmatic endometriosis followed by upper abdominal laparotomy for full-thickness resection of the diaphragm. MAIN OUTCOME MEASURE(S): Reduction of several symptoms as measured on a 5-point ranked ordinal scale administered by a phone survey up to 7 years after surgery. RESULT(S): Laparoscopy from an umbilical port may identify small "sentinel lesions" of endometriosis on the anterior or mid diaphragm. Eight symptomatic patients all had significant invasive disease with dimensions up to 5 cm across of the posterior right diaphragm, which could not always be seen from the umbilical port site. All such lesions can be seen by a laparoscope placed beneath the right costal margin. Laparoscopic treatment of symptomatic disease is not rational given the posterior placement of the disease out of sight behind the liver and the full-thickness nature of the disease in all eight patients. Laparotomy with full thickness resection of the diaphragm resulted in complete eradication of symptoms in seven of eight patients, and good symptomatic reduction in one. CONCLUSION(S): Treatment of diaphragmatic endometriosis by laparotomy results in a high rate of symptom relief. Laparoscopic treatment of diaphragmatic endometriosis will result in a high rate of incomplete diagnosis and incomplete treatment with a high rate of continuing symptoms.


Subject(s)
Diaphragm/pathology , Endometriosis/pathology , Endometriosis/surgery , Adult , Diaphragm/surgery , Female , Humans , Laparoscopy , Laparotomy , Pain Measurement , Treatment Outcome
20.
Phys Sportsmed ; 8(5): 41-52, 1980 May.
Article in English | MEDLINE | ID: mdl-29256303

ABSTRACT

Physicians need more information about the causes and the long-term consequences of amenorrhea due to exercise and weight loss before they can give proper advice to women who exercise strenuously.

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