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Williams DC, Carroll BJ, Jin Q, Rithner CD, Lenger SR, Floss HG, Coates RM, Williams RM, Croteau R. Intramolecular proton transfer in the cyclization of geranylgeranyl diphosphate to the taxadiene precursor of taxol catalyzed by recombinant taxadiene synthase. CHEMISTRY & BIOLOGY 2000; 7:969-77. [PMID: 11137819 DOI: 10.1016/s1074-5521(00)00046-6] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
BACKGROUND The committed step in the biosynthesis of the anticancer drug taxol in yew (Taxus) species is the cyclization of geranylgeranyl diphosphate to taxa-4(5),11(12)-diene. The enzyme taxadiene synthase catalyzes this complex olefin cation cyclization cascade involving the formation of three rings and three stereogenic centers. RESULTS Recombinant taxadiene synthase was incubated with specifically deuterated substrates, and the mechanism of cyclization was probed using MS and NMR analyses of the products to define the crucial hydrogen migration and terminating deprotonation steps. The electrophilic cyclization involves the ionization of the diphosphate with closure of the A-ring, followed by a unique intramolecular transfer of the C11 proton to the re-face of C7 to promote closure of the B/C-ring juncture, and cascade termination by proton elimination from the beta-face of C5. CONCLUSIONS These findings provide insight into the molecular architecture of the first dedicated step of taxol biosynthesis that creates the taxane carbon skeleton, and they have broad implications for the general mechanistic capability of the large family of terpenoid cyclization enzymes.
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Primig M, Williams RM, Winzeler EA, Tevzadze GG, Conway AR, Hwang SY, Davis RW, Esposito RE. The core meiotic transcriptome in budding yeasts. Nat Genet 2000; 26:415-23. [PMID: 11101837 DOI: 10.1038/82539] [Citation(s) in RCA: 340] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We used high-density oligonucleotide microarrays to analyse the genomes and meiotic expression patterns of two yeast strains, SK1 and W303, that display distinct kinetics and efficiencies of sporulation. Hybridization of genomic DNA to arrays revealed numerous gene deletions and polymorphisms in both backgrounds. The expression analysis yielded approximately 1,600 meiotically regulated genes in each strain, with a core set of approximately 60% displaying similar patterns in both strains. Most of these (95%) are MATa/MATalpha-dependent and are not similarly expressed in near-isogenic meiosis-deficient controls. The transcript profiles correlate with the distribution of defined meiotic promoter elements and with the time of known gene function.
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El-Ghorr AA, Williams RM, Heap C, Norval M. Transcutaneous immunisation with herpes simplex virus stimulates immunity in mice. FEMS IMMUNOLOGY AND MEDICAL MICROBIOLOGY 2000; 29:255-61. [PMID: 11118905 DOI: 10.1111/j.1574-695x.2000.tb01531.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Herpes simplex virus (HSV) is common throughout the world and is a target for vaccine development. Transcutaneous immunisation is a novel technique that uses the application of vaccine antigens in solution on the skin in the presence of cholera toxin (CT) as an adjuvant. This study investigated the potential of transcutaneous immunisation in C3H mice, using CT co-administered with whole inactivated HSV-1 (CT+HSVi) or HSV-1 antigens extracted from infected Vero cells (CT+HSVag) or a control protein (CT+BSA). The application of any of the three vaccines on to bare mouse skin resulted in the migration of Langerhans cells from the epidermis and in the production of serum antibodies to CT. Both HSV preparations generated serum and mucosal (faecal) antibodies to HSV, with the CT+HSVi vaccine being a more potent stimulator of humoral immunity. The CT+HSVag vaccine, however, was the more potent stimulator of cell-mediated immunity, giving rise to a strong delayed type hypersensitivity response and lymphocyte proliferation in vitro. When the mice were challenged by epidermal inoculation of HSV, the CT+HSVag vaccine induced a higher level of protection than the CT+HSVi vaccine, a result which may indicate that the efficacy of HSV vaccines depends on stimulation of cell-mediated rather than humoral responses. The success of topical vaccination suggests that the transcutaneous route may offer a promising potential for novel vaccine delivery which merits further investigation.
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MESH Headings
- Adjuvants, Immunologic
- Administration, Cutaneous
- Animals
- Antibodies, Viral/analysis
- Antibodies, Viral/blood
- Antigens, Viral/administration & dosage
- Antigens, Viral/immunology
- B-Lymphocytes/immunology
- Cholera Toxin/immunology
- Herpes Simplex/immunology
- Herpes Simplex/prevention & control
- Herpes Simplex Virus Vaccines/administration & dosage
- Herpes Simplex Virus Vaccines/immunology
- Herpesvirus 1, Human/immunology
- Humans
- Hypersensitivity, Delayed
- Immunity, Mucosal
- Langerhans Cells/physiology
- Lymphocyte Activation
- Mice
- Mice, Inbred C3H
- T-Lymphocytes/immunology
- Vaccination
- Vaccines, Inactivated/immunology
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Vázquez A, Williams RM. Studies on the biosynthesis of taxol. Synthesis Of taxa-4(20), 11(12)-diene-2alpha,5alpha-diol. J Org Chem 2000; 65:7865-9. [PMID: 11073592 DOI: 10.1021/jo005537+] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synthesis of taxa-4(20),11(12)-diene-2alpha,5alpha-diol is described. An improved procedure for the intramolecular Diels-Alder cycloaddition previously reported in our synthesis of taxa-4(5), 11(12)-diene has been utilized to prepare a taxoid with oxygenation in the B and C rings. It has been established previously that taxa-4(20),11(12)-dien-5alpha-ol is the first oxygenated intermediate on the biosynthetic pathway to Taxol. Taxa-4(20), 11(12)-diene-2alpha,5alpha-diol (5), which has been observed in a biosynthetic conversion, is a potential candidate as the second oxygenated intermediate on the Taxol biosynthetic pathway, has been prepared to probe the intermediacy of this substance.
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Abstract
The pH cycling of individual granules in secreting (serotonin-loaded) mast cells is quantitatively examined using multicolor multiphoton fluorescence microscopy. A typical exocytosis event consists of maximal calcium rise at time zero, granule alkalization a few seconds later and, finally, complete contents release at a fraction of a second after alkalization. Membrane fusion is either transient, as indicated by subsequent granule reacidification, or ‘full’, as indicated by a granule disappearance with a collapse of its membrane into the plasma membrane. The relative frequency of these two coexisting behaviors (the ‘kiss-to-collapse’ ratio) is approximately 2:1. A typical transiently fusing granule experiences multiple alkalization/acidification cycles after addition of exogenous antigen. Between recycling granules, coalescence events are frequent, with 80% resulting in a collapse of the formed granule complex to the plasma membrane. The full dynamics of secretion encompass a complex combination of these granule activities.
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Sanz-Cervera JF, Stocking EM, Usui T, Osada H, Williams RM. Synthesis and evaluation of microtubule assembly inhibition and cytotoxicity of prenylated derivatives of cyclo-L-Trp-L-Pro. Bioorg Med Chem 2000; 8:2407-15. [PMID: 11058035 DOI: 10.1016/s0968-0896(00)00171-1] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The synthesis of three isoprenylated derivatives of cyclo-L-Trp-L-Pro is described. These substances have been evaluated for cytotoxic activity in rat normal fibroblast 3Y1 cells and have also been evaluated in vitro for the inhibition of microtubule assembly.
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Rose A, Lee RJ, Williams RM, Thomson LC, Forsyth A. Functional instability in non-contact ankle ligament injuries. Br J Sports Med 2000; 34:352-8. [PMID: 11049145 PMCID: PMC1756237 DOI: 10.1136/bjsm.34.5.352] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
OBJECTIVES To measure objectively functional standing balance in the acute stages of non-contact ankle sprain, and to compare patients with controls. METHODS A Chattanooga balance machine was used to measure postural stability in patients with acute ankle sprain and uninjured controls over a two week period, in one and two legged stance, with eyes open and closed. Participants also completed the Olerud and Molander questionnaire to provide a subjective measure of ankle function. RESULTS There was a highly significant improvement in questionnaire scores for the patients during the study period (p<0.0001). Patients appeared to be less stable than controls in all balance tests, although the difference did not reach significance. There was evidence of improvement over time in the number of tests successfully completed on the injured leg in single legged stance with eyes closed (p = 0.043) between visits 1 and 3. CONCLUSIONS The patient group showed a subjective improvement, which supports clinical experience of treating acute ankle injuries. There is some evidence that on average the patient group appeared to be less stable than controls in all balance tests, although the difference did not reach statistical significance, even on the uninjured leg. There is a need to carry out further studies to confirm the results found in this pilot study and to investigate the hypotheses generated. It would be useful to evaluate a simple test that could be used clinically to monitor progress after ankle injury, and also to identify athletes with decreased functional stability, who may be more at risk of sustaining ankle injury.
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Beckerbauer L, Tepe JJ, Cullison J, Reeves R, Williams RM. FR900482 class of anti-tumor drugs cross-links oncoprotein HMG I/Y to DNA in vivo. CHEMISTRY & BIOLOGY 2000; 7:805-12. [PMID: 11033083 DOI: 10.1016/s1074-5521(00)00028-4] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Overexpression of the high-mobility group, HMG I/Y, family of chromatin oncoproteins has been implicated as a clinical diagnostic marker for both neoplastic cellular transformation and increased metastatic potential of several human cancers. These minor groove DNA-binding oncoproteins are thus an attractive target for anti-tumor chemotherapy. FR900482 represents a new class of anti-tumor agents that bind to the minor groove of DNA and exhibit greatly reduced host toxicity compared to the structurally related mitomycin C class of anti-tumor drugs. We report covalent cross-linking of DNA to HMG I/Y by FR900482 in vivo which represents the first example of a covalent DNA-drug-protein cross-link with a minor groove-binding oncoprotein and a potential novel mechanism through which these compounds exert their anti-tumor activity. RESULTS Using a modified chromatin immunoprecipitation procedure, fragments of DNA that have been covalently cross-linked by FR900482 to HMG I/Y proteins in vivo were polymerase chain reaction-amplified, isolated and characterized. The nuclear samples from control cells were devoid of DNA fragments whereas the nuclear samples from cells treated with FR900482 contained DNA fragments which were cross-linked by the drug to the minor groove-binding HMG I/Y proteins in vivo. Additional control experiments established that the drug also cross-linked other non-oncogenic minor groove-binding proteins (HMG-1 and HMG-2) but did not cross-link major groove-binding proteins (Elf-1 and NFkappaB) in vivo. Our results are the first demonstration that FR900482 cross-links a number of minor groove-binding proteins in vivo and suggests that the cross-linking of the HMG I/Y oncoproteins may participate in the mode of efficacy as a chemotherapeutic agent. CONCLUSIONS We have illustrated that the FR class of anti-tumor antibiotics, represented in this study by FR900482, is able to produce covalent cross-links between the HMG I/Y oncoproteins and DNA in vivo. The ability of this class of compounds to cross-link the HMG I/Y proteins in the minor groove of DNA represents the first demonstration of drug-induced cross-linking of a specific cancer-related protein to DNA in living cells. We have also demonstrated that FR900482 cross-links other minor groove-binding proteins (HMG-1 and HMG-2 in the present study) in vivo; however, since HMG I/Y is the only minor groove-binding oncoprotein presently known, it is possible that these non-histone chromatin proteins are among the important in vivo targets of this family of drugs. These compounds have already been assessed as representing a compelling clinical replacement for mitomycin C due to their greatly reduced host toxicity and superior DNA interstrand cross-linking efficacy. The capacity of FR900482 to cross-link the HMG I/Y oncoprotein with nuclear DNA in vivo potentially represents a significant elucidation of the anti-tumor efficacy of this family of anticancer agents.
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Nightingale J, Williams RM. Attitudes to emotional expression and personality in predicting post-traumatic stress disorder. BRITISH JOURNAL OF CLINICAL PSYCHOLOGY 2000; 39:243-54. [PMID: 11033747 DOI: 10.1348/014466500163266] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVES To test hypotheses derived from a suggestion of Williams (1989) that negative attitudes towards emotional expression act as a predisposing or maintaining factor for post-traumatic stress reactions following a traumatic event. DESIGN The study employed a prospective design in which attitudes to emotional expression, the 'Big Five' personality factors (Costa & McCrae, 1992a) and initial symptoms and injury severity within 1 week of a road traffic accident were used to predict the development of post-traumatic stress disorder 6 weeks post-accident. METHOD Sixty victims of road traffic accidents randomly selected from attenders at a large A&E department were assessed by questionnaire and interview. Measures comprised a 4-item scale relating to emotional expression, standardized scales for intrusion and avoidance features of traumatic experiences, and for anxiety and depression and the NEO-FFI Five Factor Personality Inventory. Forty-five of these participants responded to a postal questionnaire follow-up. In this survey the battery was repeated and also included a self-report diagnostic measure of post-traumatic stress disorder (PTSD). RESULTS The percentage of the sample meeting DSM-IV diagnostic criteria for PTSD at 6 weeks post-trauma was 30.8%. A small but significant relationship was found for negative attitudes to emotional expression at 1 week to predict intrusive symptoms and diagnosis at 6 weeks, over and above the independent relationships of initial symptoms, initial injury severity, personality and coping. The emotional expression measure was largely stable between the two points of measurement. More negative attitudes to emotional expression were related to less openness, extraversion and agreeableness personality domains. CONCLUSIONS Some support for the hypotheses was found in relation to the development of PTSD and for the status of attitudes to emotion as a stable trait related to personality factors. The potential importance of attitudes to emotional expression in therapy and other work is discussed.
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Williams RM, Cao J, Tsujishima H. Asymmetric, Stereocontrolled Total Synthesis of Paraherquamide A This work was supported by the NIH (Grant CA 70375). The Japanese Society for the Promotion of Science (JSPS) is acknowledged for providing support to H.T. Mass spectra were obtained on instruments supported by the NIH Shared Instrumentation Grant (GM 49631). We also wish to thank Dr. Timothy Blizzard (Merck & Co.) for providing an authentic sample of natural paraherquamide A. We also wish to acknowledge Dr. Byung H. Lee (Pharmacia-Upjohn Co.) for providing NMR spectra and an authentic specimen of 14-oxoparaherquamide B. We also wish to thank Dr. Alfredo Vazquez for assistance with purification and characterization of synthetic paraherquamide A. Angew Chem Int Ed Engl 2000; 39:2540-2544. [PMID: 10941129 DOI: 10.1002/1521-3773(20000717)39:14<2540::aid-anie2540>3.0.co;2-r] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Abstract
Congenital absence of the breast is a rare condition. The literature shows that there is much heterogeneity in its presentation as well as its inheritance. We described a mother and daughter with the condition and how the mother underwent breast reconstruction with use of bilateral transverse rectus abdominis myocutaneous flaps.
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Watkins E, Teasdale JD, Williams RM. Decentring and distraction reduce overgeneral autobiographical memory in depression. Psychol Med 2000; 30:911-920. [PMID: 11037099 DOI: 10.1017/s0033291799002263] [Citation(s) in RCA: 140] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Increased recall of categorical autobiographical memories is a phenomenon unique to depression and post-traumatic stress disorder, and is associated with a poor prognosis for depression. Although the elevated recall of categorical memories does not change on remission from depression, recent findings suggest that overgeneral memory may be reduced by cognitive interventions and maintained by rumination. This study tested whether cognitive manipulations could influence the recall of categorical memories in dysphoric participants. METHODS Forty-eight dysphoric and depressed participants were randomly allocated to rumination or distraction conditions. Before and after the manipulation, participants completed the Autobiographical Memory Test, a standard measure of overgeneral memory. Participants were then randomized to either a 'decentring' question (Socratic questions designed to facilitate viewing moods within a wider perspective) or a control question condition, before completing the Autobiographical Memory Test again. RESULTS Distraction produced significantly greater decreases in the proportion of memories retrieved that were categorical than rumination. Decentring questions produced significantly greater decreases in the proportion of memories retrieved that were categorical than control questions, with this effect independent of the prior manipulation. CONCLUSIONS Elevated categorical memory in depression is more modifiable than has been previously assumed; it may reflect the dynamic maintenance of a cognitive style that can be interrupted by brief cognitive interventions.
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Williams RM, Petre R, Chu YH, Chen C. Resolving SNR 0540-6944 from LMC X-1 with Chandra. THE ASTROPHYSICAL JOURNAL 2000; 536:L27-L30. [PMID: 10849412 DOI: 10.1086/312729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2000] [Accepted: 05/03/2000] [Indexed: 05/23/2023]
Abstract
We examine the supernova remnant SNR 0540-697 in the Large Magellanic Cloud (LMC) using data from the Chandra Advanced CCD Imaging Spectrometer. The X-ray emission from this supernova remnant (SNR) had previously been hidden in the bright emission of the nearby X-ray binary LMC X-1; however, new observations with Chandra can finally reveal the SNR's structure and spectrum. We find the SNR to be a thick-shelled structure about 19 pc in diameter, with a brightened northeast region. Spectral results suggest a temperature of 0.31 keV and an X-ray luminosity (0.3-3.0 keV) of 8.4x1033 ergs s(-1). We estimate an age of 12,000-20,000 yr for this SNR, but note that this estimate does not take into account the possibility of cavity expansion or other environmental effects.
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Rajski SR, Williams RM. Observations on the covalent cross-linking of the binding domain (BD) of the high mobility group I/Y (HMG I/Y) proteins to DNA by FR66979. Bioorg Med Chem 2000; 8:1331-42. [PMID: 10896111 DOI: 10.1016/s0968-0896(00)00078-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
FR66979, a drug closely related to the mitomycin C class of antitumor antibiotics, is shown to covalently cross-link DNA to the DNA-binding domain of the High Mobility Group I/Y (HMG I/Y) DNA-binding proteins in the minor groove.
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Moy RL, Williams RM. Statistical report for 1999. Dermatol Surg 2000; 26:173. [PMID: 10759787 DOI: 10.1046/j.1524-4725.2000.00901.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Herberich B, Scott JD, Williams RM. Synthesis of a netropsin conjugate of a water-soluble epi-quinocarcin analogue: the importance of stereochemistry at nitrogen. Bioorg Med Chem 2000; 8:523-32. [PMID: 10732968 DOI: 10.1016/s0968-0896(99)00314-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The efficient synthesis of a water-soluble C11a-epi-analogue (6b) of quinocarcin is described. This substance, and a netropsin amide conjugate (8) lack the capacity to inflict oxidative damage on DNA due to the stereoelectronic geometry of their oxazolidine nitrogen atoms. The capacity of these substances to alkylate DNA through the generation of an iminium species has been examined. Both compounds were found to be unreactive as DNA alkylating agents. The results of this study are discussed in the context of previous proposals on the mode of action of this family of antitumor alkaloids.
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Williams RM, Kelly JF, Hartman JS, Sharpe SW, Taubman MS, Hall JL, Capasso F, Gmachl C, Sivco DL, Baillargeon JN, Cho AY. Kilohertz linewidth from frequency-stabilized mid-infrared quantum cascade lasers. OPTICS LETTERS 1999; 24:1844-1846. [PMID: 18079950 DOI: 10.1364/ol.24.001844] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Frequency stabilization of mid-IR quantum cascade (QC) lasers to the kilohertz level has been accomplished by use of electronic servo techniques. With this active feedback, an 8.5-microm QC distributed-feedback laser is locked to the side of a rovibrational resonance of nitrous oxide (N(2) O) at 1176.61cm (-1) . A stabilized frequency-noise spectral density of 42Hz/ radicalHz has been measured at 100 kHz; the calculated laser linewidth is 12 kHz.
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Tepe JJ, Williams RM. Reductive Activation of a Hydroxylamine Hemiacetal Derivative of Dehydromonocrotaline: The First Reductively Activated Pyrrolizidine Alkaloid Capable of Cross-Linking DNA. Angew Chem Int Ed Engl 1999; 38:3501-3503. [PMID: 10602221 DOI: 10.1002/(sici)1521-3773(19991203)38:23<3501::aid-anie3501>3.0.co;2-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The acute hepatotoxicity displayed by the pyrrolizidine alkaloids, which obviates their clinical utility, is a result of activation in vivo by cytochrome P450 mediated oxidation. Now the first reductively activated progenitor of the highly cytotoxic dehydropyrrolizidine alkaloid dehydromonocrotaline has been synthesized and demonstrated to mediate interstrand DNA cross-link formation (see scheme); pyrrolizidine alkaloids exert their cytotoxicity through the formation of DNA-DNA interstrand and DNA-protein cross-links.
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Williams RM, Gladstone HB, Moy RL. Hair removal using an 810 nm gallium aluminum arsenide semiconductor diode laser: A preliminary study. Dermatol Surg 1999; 25:935-7. [PMID: 10594625 DOI: 10.1046/j.1524-4725.1999.99174.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Laser hair removal is a popular treatment method for removing unwanted hair. Several laser systems are available for laser hair removal. The gallium aluminum arsenide semiconductor diode (GAASD) laser is one of the newer laser modalities to be studied. OBJECTIVE To evaluate the efficacy of the GAASD laser system in removing unwanted hair. METHODS Twenty-six patients with brown or black hair growth were treated with the GAASD laser at fluences of 20-80 J/cm2. Hair regrowth was measured 4 weeks after the first treatment, 4 weeks after the second treatment, 4 weeks after the third treatment, and 4 weeks, 8 weeks, and 8 months after the fourth treatment. CONCLUSION GAASD laser treatment resulted in hair growth delay in all treated regions. Repeated laser treatments did not produce an increased number of vellus hairs. The percentage of hair reduction fluctuated between 5% and 13% with the second or third treatment averaging the highest percent reduction. In all cases, the percentage of hair reduction of the treatment sites evaluated at 8 months after the fourth treatment was less than both the second and third treatments (highest average percent reduction) and the fourth (last) treatment.
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Denton DA, Blair-West JR, McBurnie MI, Miller JA, Weisinger RS, Williams RM. Effect of adrenocorticotrophic hormone on sodium appetite in mice. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 277:R1033-40. [PMID: 10516242 DOI: 10.1152/ajpregu.1999.277.4.r1033] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A main vector of the effects of stress is secretion of corticotrophin releasing factor (CRF), adrenocorticotrophin (ACTH), and adrenal steroids. Systemic administration of ACTH (2.8 microgram/day sc) for 7 days in BALB/c mice caused a very large increase of voluntary intake of 0.3 M NaCl equivalent to turnover of total body sodium content each day. Intracerebroventricular infusion of ACTH (20 ng/day) had no effect. Intracerebroventricular infusion of ovine CRF (10 ng/h for 7 days) caused an increase of sodium intake. The large sodium appetite-stimulating effect of systemic ACTH was not influenced by concurrent systemic infusion of captopril (2 mg/day). Induction of stress by immobilization of mice on a running wheel caused an increase in Na appetite associated with a 50% decrease of thymus weight, indicative of corticosteroid effects. The present data suggest that stress and the hormone cascade initiated by stress evoke a large sodium appetite in mice, which may be an important survival mechanism in environmental conditions causing stress.
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Menaker GM, Wrone DA, Williams RM, Moy RL. Treatment of facial rhytids with a nonablative laser: a clinical and histologic study. Dermatol Surg 1999; 25:440-4. [PMID: 10469089 DOI: 10.1046/j.1524-4725.1999.08158.x] [Citation(s) in RCA: 168] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Current facial resurfacing modalities (laser, chemical peels, and dermabrasion) remove the epidermis and thus cause open wounds which carry significant risks and extended recovery periods. The nonablative laser is a novel Nd:YAG system designed to alleviate facial rhytids without injuring the epidermis. This new modality may offer patients rhytid removal without the risk seen in currently used resurfacing techniques. OBJECTIVE To describe a novel nonablative laser system and assess its safety profile and efficacy. METHODS Ten patients received laser treatments of their periocular rhytids and postauricular skin. Clinical variables (rhytid severity, hyperpigmentation, hypopigmentation, scarring, and level of discomfort) were assessed at 1 and 3 months posttreatment. Postauricular skin biopsies were taken both pre- and posttreatment for histologic analysis. RESULTS Patient discomfort was minimal. Three months posttreatment, 4 of 10 patients showed a one-point improvement in periocular rhytid severity when judged on a six-point scale. The results were not statistically significant. Biopsy analysis showed a small posttreatment increase in the amount of dermal collagen in three patients. A small decrease in collagen was noted in one patient. Three patients also showed a small posttreatment increase in the degree homogenization of dermal collagen. No change from baseline was noted in other assessed histologic parameters. Complications observed included hyperpigmentation in three patients and pitted scarring in three patients. CONCLUSIONS The nonablative laser gave clinically subtle and statistically insignificant improvement in rhytid severity. Unfortunately its use was associated with complications that included hyperpigmentation and scarring. This technology may eventually offer patients a new resurfacing option, but its efficacy and complication rate must be improved first.
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Abstract
The long-pulsed ruby laser is a faster, more effective method for the removal of unwanted hair compared to older, temporary techniques like shaving, waxing, and chemical depilation. It is the only laser approved by the FDA for permanent hair removal. Patients experience minimal pain and side effects, observe immediate hair growth delay, an increase in vellus hairs, and have the potential for permanent hair removal. Although treatment sessions can be lengthy, the laser is easy to operate and the cooled handpiece allows patients to easily tolerate long sessions.
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Williams RM, Shear JB, Zipfel WR, Maiti S, Webb WW. Mucosal mast cell secretion processes imaged using three-photon microscopy of 5-hydroxytryptamine autofluorescence. Biophys J 1999; 76:1835-46. [PMID: 10096882 PMCID: PMC1300160 DOI: 10.1016/s0006-3495(99)77343-1] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The secretion process of the mucosal mast cell line RBL-2H3 was imaged using infrared three photon excitation (3PE) of serotonin (5-hydroxytryptamine, 5-HT) autofluorescence, a measurement previously difficult because of the technical intractability of deep UV optics. Images of prestimulation 5-HT distributions were analyzed in loaded cell populations (those incubated in a 5-HT-rich medium overnight) and in unloaded populations and were found to be strictly quantifiable by comparison with bulk population high-performance liquid chromatography measurements. Antigenically stimulated cells were observed to characteristically ruffle and spread as granular 5-HT disappeared with no detectable granule movement. Individual cells exhibited highly heterogeneous release kinetics, often with quasi-periodic bursts. Neighboring granule disappearances were correlated, indicative of either spatially localized signaling or granule-granule interactions. In one-half of the granule release events, weak residual fluorescence was visible suggestive of leftover 5-HT still bound to the granule matrix. The terminal stages of secretion (>300 s) consisted primarily of unresolved granules and remainder 5-HT leakage from already released granules.
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Bago B, Zipfel W, Williams RM, Piché Y. Nuclei of symbiotic arbuscular mycorrhizal fungi as revealed by in vivo two-photon microscopy. PROTOPLASMA 1999; 209:77-89. [PMID: 18987796 DOI: 10.1007/bf01415703] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/1998] [Accepted: 03/16/1999] [Indexed: 05/27/2023]
Abstract
The present work reports the results obtained from in vivo studies on the distribution and behavior of nuclei of two arbuscular mycorrhizal (AM) fungi growing in symbiosis with tomato root organ cultures (AM monoxenic cultures). Upon staining with 4',6-diamidino-2-phenylindole and two-photon microscopy (2PM) observations, symbiotic thick runner hyphae appeared mostly opaque to 2PM and did not reveal nuclei within them; thin runner hyphae showed dimly stained nuclei along them, whereas nuclei were clearly visible within the branches of the so-called branched absorbing structures. When visible, nuclei appeared anchored laterally at regular intervals along the symbiotic AM extraradical hyphae. Other nuclei migrate through the hyphal central core; this migration occurs in pulses. Simultaneous observations on different areas of extraradical AM mycelium revealed the existence of lysed compartments along the fungal hyphae, containing nuclei remnants and/or chromatin masses. All these results give new insights in (i) the differential permeability of AM hyphae in the symbiotic versus the asymbiotic state; (ii) the behavior and distribution of nuclei along the symbiotic extraradical mycelium; (iii) the occurrence of ageing events within the AM fungal colony; and (iv) the existence of "healing" mechanisms aiming to restrict the damage induced by such ageing or lytic events. An AM fungal strategy for hyphal survival under adverse conditions is also suggested.
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