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Alexander RP, Warrellow GJ, Eaton MAW, Boyd EC, Head JC, Porter JR, Brown JA, Reuberson JT, Hutchinson B, Turner P, Boyce B, Barnes D, Mason B, Cannell A, Taylor RJ, Zomaya A, Millican A, Leonard J, Morphy R, Wales M, Perry M, Allen RA, Gozzard N, Hughes B, Higgs G. CDP840. A prototype of a novel class of orally active anti-inflammatory phosphodiesterase 4 inhibitors. Bioorg Med Chem Lett 2002; 12:1451-6. [PMID: 12031318 DOI: 10.1016/s0960-894x(02)00202-0] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The discovery, synthesis and biological activity of a series of triarylethane phosphodiesterase 4 inhibitors is described. Structure-activity relationship studies are presented for CDP840 (29), a potent, chiral, selective inhibitor of PDE 4 (IC(50) 4nM). CDP840 is non-emetic in the ferret at 30mgkg(-1) (po), active in models of inflammation and reverses ozone-induced bronchial hyperreactivity in the guinea pig.
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102
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Puvanendran V, Leader LL, Brown JA. Foraging behaviour of Atlantic cod (Gadus morhua) larvae in relation to prey concentration. CAN J ZOOL 2002. [DOI: 10.1139/z02-045] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In spite of a tremendous amount of research on Atlantic cod (Gadus morhua) larvae, no information is available on the development of foraging behaviour over an extended period. We investigated the ontogeny of foraging behaviour of Atlantic cod larvae exposed to different prey concentrations from hatching to metamorphosis. The objective of this work was to determine if their foraging behaviour is influenced by prey concentration. Rotifers and (or) Artemia sp. were used as prey at concentrations of 0, 500, 1000, 2000, and 4000/L. During behavioural observations, which were carried out twice a week, foraging behaviour and activity of cod larvae were quantified. Larvae were sampled once a week and standard length and gut fullness were recorded. Larvae reared at concentrations of 1000 and 2000 prey/L swam significantly more but foraged (quantified by capture success) significantly less than the larvae reared at 4000 prey/L. Larvae reared at 4000 prey/L performed more orientations towards prey than larvae reared at all lower prey concentrations and the time spent per orientation increased from day 2 at all prey concentrations but declined as the larvae grew. However, this decline occurred earlier in larvae reared at 4000 prey/L than in larvae reared at other prey concentrations, and larvae reared at 4000 prey/L spent the shortest time per orientation at day 27 compared with day 34. Larvae reared at 4000 prey/L showed significantly higher success in capturing prey than larvae reared at all lower prey concentrations. After day 13 post hatch, larvae reared at 4000 prey/L were significantly greater in length than larvae reared at all other prey concentrations. Larvae reared at 0, 500, and 1000 prey/L did not survive beyond 11, 15, and 32 days, respectively, indicating that fewer than 2000 prey/L may not be adequate to keep cod larvae alive during intensive rearing. Our results suggest that the foraging behaviour of Atlantic cod larvae is influenced by prey concentration.
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103
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Enns R, Schmidt N, Harrison P, Chipperfield P, Skarsgaard P, Brown JA. Endoscopic diagnosis of a right hepatic artery pseudoaneurysm. Endoscopy 2002; 34:337-40. [PMID: 11932793 DOI: 10.1055/s-2002-23635] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
Hepatic artery aneurysms are rare occurrences with diverse etiologies. We present a case of a right hepatic artery aneurysm, which was diagnosed at endoscopic retrograde cholangiography (ERC) and treated angiographically. This is the first report where ERC has been critical in delineating the aneurysmal cavity, suggesting the diagnosis and prompting emergency intervention.
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104
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Brown JA. Motor cortex stimulation. Neurosurg Focus 2001; 11:E5. [PMID: 16519425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
In 1991 Tsubokawa and colleagues first published their landmark results from a series in which epidural motor cortex stimulation (MCS) was used in the treatment of eight patients with central and neuropathic pain. In ensuing studies authors have elaborated on the indications, technique, hypotheical mechanisms, and beneficial results of this treatment. Epidural MCS is effective for trigeminal neuropathy, lateral medullary and thalamic infarction, anesthesia dolorosa, postherpetic neuralgia, spinal cord injury, and limb stump pain. Postoperative outcomes are better when patients present with only mild or absent motor weakness in the region of pain and when there is pain in the trigeminal region. It is hypothesized that MCS is effective because it increases regional cerebral blood flow in the ipsilateral ventrolateral thalamus in which corticothalamic connections from the motor and premotor areas predominate. The extent of pain alleviation also correlates with the increase of blood flow in the cingulate gyrus. This suggests that stimulation reduces the suffering experienced by a patient with chronic pain. Procedure-related morbidity has included epidural hematoma, subdural effusion, gradual diminution of benefit, and painful stimulation. Although of concern, treatment-induced chronic seizure disorders have not occurred as a complication or in animal models of chronic cortical stimulation. Stimulation-induced pain relief occurs within minutes. There are no associated paresthesias or muscle contractions that confirm function. Pain relief may last for hours after electrical stimulation is discontinued. Motor cortex stimulation is an established therapy for the treatment of complex central and neuropathic pain syndromes that have proved refractory to medical treatment.
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105
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Baecher-Allan C, Brown JA, Freeman GJ, Hafler DA. CD4+CD25high regulatory cells in human peripheral blood. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:1245-53. [PMID: 11466340 DOI: 10.4049/jimmunol.167.3.1245] [Citation(s) in RCA: 1379] [Impact Index Per Article: 60.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Thymectomy in mice on neonatal day 3 leads to the development of multiorgan autoimmune disease due to loss of a CD(+)CD25(+) T cell regulatory population in their peripheral lymphoid tissues. Here, we report the identification of a CD4(+) population of regulatory T cells in the circulation of humans expressing high levels of CD25 that exhibit in vitro characteristics identical with those of the CD4(+)CD25(+) regulatory cells isolated in mice. With TCR cross-linking, CD4(+)CD25(high) cells did not proliferate but instead totally inhibited proliferation and cytokine secretion by activated CD4(+)CD25(-) responder T cells in a contact-dependent manner. The CD4(+)CD25(high) regulatory T cells expressed high levels of CD45RO but not CD45RA, akin to the expression of CD45RB(low) on murine CD4(+)CD25(+) regulatory cells. Increasing the strength of signal by providing either costimulation with CD28 cross-linking or the addition of IL-2 to a maximal anti-CD3 stimulus resulted in a modest induction of proliferation and the loss of observable suppression in cocultures of CD4(+)CD25(high) regulatory cells and CD4(+)CD25(-) responder cells. Whereas higher ratios of CD4(+)CD25(high) T cells are required to suppress proliferation if the PD-L1 receptor is blocked, regulatory cell function is shown to persist in the absence of the PD-1/PD-L1 or CTLA-4/B7 pathway. Thus, regulatory CD4 T cells expressing high levels of the IL-2 receptor are present in humans, providing the opportunity to determine whether alterations of these populations of T cells are involved in the induction of human autoimmune disorders.
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MESH Headings
- Abatacept
- Antigens, CD
- Antigens, Differentiation/physiology
- B7-1 Antigen
- B7-H1 Antigen
- Blood Proteins
- CD4 Antigens/biosynthesis
- CD4 Antigens/blood
- CD4-Positive T-Lymphocytes/immunology
- CD4-Positive T-Lymphocytes/metabolism
- CTLA-4 Antigen
- Cells, Cultured
- Coculture Techniques
- HLA-DR Antigens/biosynthesis
- Humans
- Immunoconjugates
- Immunosuppressive Agents/pharmacology
- Interleukin-2/antagonists & inhibitors
- Interleukin-2/genetics
- Kinetics
- Leukocyte Common Antigens/biosynthesis
- Lymphocyte Activation
- Lymphocyte Count
- Membrane Glycoproteins
- Peptides/physiology
- RNA, Messenger/antagonists & inhibitors
- RNA, Messenger/metabolism
- Receptors, Antigen, T-Cell/immunology
- Receptors, Antigen, T-Cell/metabolism
- Receptors, Antigen, T-Cell/physiology
- Receptors, Interleukin-2/biosynthesis
- Receptors, Interleukin-2/blood
- Signal Transduction/immunology
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/metabolism
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106
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Rankin JC, Cobb CS, Frankling SC, Brown JA. Circulating angiotensins in the river lamprey, Lampetra fluviatilis, acclimated to freshwater and seawater: possible involvement in the regulation of drinking. Comp Biochem Physiol B Biochem Mol Biol 2001; 129:311-8. [PMID: 11399464 DOI: 10.1016/s1096-4959(01)00336-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Plasma angiotensin levels were measured for the first time in a cyclostome, the river lamprey. With the demonstration that angiotensins are present in the circulation, the possibility of a physiological role in the regulation of drinking was re-examined. Angiotensin II and III concentrations and plasma osmolalities were significantly higher in lampreys acclimated to 28 ppt seawater than in those acclimated to freshwater. No changes were found in angiotensin II and III levels 4 h after transfer from freshwater to 50% seawater, although plasma osmolality had started to rise by this time. There was a suggestion that plasma angiotensin II levels might be related to osmolality in the transfer experiment. Injection of Asp(1)Val(5)- or Asn(1)Val(5)-angiotensin II (40-169 microg/kg body wt.) did not stimulate drinking in freshwater-acclimated lampreys, even when they were still capable of drinking. The angiotensin-converting enzyme inhibitor captopril and the smooth muscle relaxant papaverine both reduced drinking rate in 50% seawater-acclimated lampreys. The data do not provide direct evidence for the involvement of the renin-angiotensin system in the control of drinking behaviour in the lamprey. Indirect evidence from the captopril effect is suggestive, but could have other explanations.
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107
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108
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Purchase CF, Goddard SV, Brown JA. Production of antifreeze glycoproteins in cultured and wild juvenile Atlantic cod (Gadus morhua L.) in a common laboratory environment. CAN J ZOOL 2001. [DOI: 10.1139/z01-025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Many fishes accumulate antifreeze proteins or antifreeze glycoproteins (AFGPs) in the blood to increase their chances of survival in cold seawater. Cod (Gadus morhua L.) from colder environments have been found to produce more AFGPs than those from warmer areas, but the genetic and environmental contributions to this variation have not been determined. Populations of cultured (from the Grand Banks; Gulf of Maine) and wild (from Fortune Bay; Bonavista Bay) juvenile cod were kept in a common laboratory environment to investigate differences in AFGP production. All the populations were capable of producing AFGPs, and the AFGP levels were similar in cultured and wild cod. The results indicate that high temperatures associated with the production of cultured cod do not negatively affect the ability to produce AFGPs. In addition, young cod from as far south as the Gulf of Maine are capable of producing AFGPs at levels similar to those from the northeast coast of Newfoundland.
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Guzman-Perez A, Wester RT, Allen MC, Brown JA, Buchholz AR, Cook ER, Day WW, Hamanaka ES, Kennedy SP, Knight DR, Kowalczyk PJ, Marala RB, Mularski CJ, Novomisle WA, Ruggeri RB, Tracey WR, Hill RJ. Discovery of zoniporide: a potent and selective sodium-hydrogen exchanger type 1 (NHE-1) inhibitor with high aqueous solubility. Bioorg Med Chem Lett 2001; 11:803-7. [PMID: 11277524 DOI: 10.1016/s0960-894x(01)00059-2] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Zoniporide (CP-597,396) is a potent and selective inhibitor of NHE-1, which exhibits high aqueous solubility and acceptable pharmacokinetics for intravenous administration. The discovery, synthesis, activities, and rat and dog pharmacokinetics of this compound are presented. The potency and selectivity of zoniporide may be due to the conformation that the molecule adopts due to the presence of a cyclopropyl and a 5-quinolinyl substituent on the central pyrazole ring of the molecule.
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110
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Latchman Y, Wood CR, Chernova T, Chaudhary D, Borde M, Chernova I, Iwai Y, Long AJ, Brown JA, Nunes R, Greenfield EA, Bourque K, Boussiotis VA, Carter LL, Carreno BM, Malenkovich N, Nishimura H, Okazaki T, Honjo T, Sharpe AH, Freeman GJ. PD-L2 is a second ligand for PD-1 and inhibits T cell activation. Nat Immunol 2001; 2:261-8. [PMID: 11224527 DOI: 10.1038/85330] [Citation(s) in RCA: 2102] [Impact Index Per Article: 91.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Programmed death I (PD-I)-deficient mice develop a variety of autoimmune-like diseases, which suggests that this immunoinhibitory receptor plays an important role in tolerance. We identify here PD-1 ligand 2 (PD-L2) as a second ligand for PD-1 and compare the function and expression of PD-L1 and PD-L2. Engagement of PD-1 by PD-L2 dramatically inhibits T cell receptor (TCR)-mediated proliferation and cytokine production by CD4+ T cells. At low antigen concentrations, PD-L2-PD-1 interactions inhibit strong B7-CD28 signals. In contrast, at high antigen concentrations, PD-L2-PD-1 interactions reduce cytokine production but do not inhibit T cell proliferation. PD-L-PD-1 interactions lead to cell cycle arrest in G0/G1 but do not increase cell death. In addition, ligation of PD-1 + TCR leads to rapid phosphorylation of SHP-2, as compared to TCR ligation alone. PD-L expression was up-regulated on antigen-presenting cells by interferon gamma treatment and was also present on some normal tissues and tumor cell lines. Taken together, these studies show overlapping functions of PD-L1 and PD-L2 and indicate a key role for the PD-L-PD-1 pathway in regulatingT cell responses.
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111
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Brown JA. Percutaneous treatment of trigeminal neuralgia: advances and problems. CLINICAL NEUROSURGERY 2001; 46:455-72. [PMID: 10944695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
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112
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Brown JA, Paley RK, Amer S, Aves SJ. Evidence for an intrarenal renin-angiotensin system in the rainbow trout, Oncorhynchus mykiss. Am J Physiol Regul Integr Comp Physiol 2000; 278:R1685-91. [PMID: 10848539 DOI: 10.1152/ajpregu.2000.278.6.r1685] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Physiological and molecular approaches were used to investigate the existence of an intrarenal renin-angiotensin system (RAS) in rainbow trout. Inhibition of angiotensin-converting enzyme by captopril (5 x 10(-4 )M) rapidly decreased vascular resistance of the trunk of the trout, perfused at 19 mmHg, resulting in an increased perfusate flow rate and a decreased intrarenal dorsal aortic pressure. A profound diuresis occurred in the in situ perfused kidney and reflected both increased glomerular filtration rates and decreased water reabsorption (osmolyte reabsorption was unchanged). Renal and vascular parameters recovered once captopril treatment was stopped. Diuretic and vascular effects of captopril on the in situ trout kidney concur with an inhibition of known vasoconstrictor and antidiuretic actions of angiotensin II. However, at a higher perfusion pressure (28 mmHg), captopril had no effect on intrarenal aortic pressure or perfusate and urine flow rates, suggesting that the trout intrarenal RAS is activated by low perfusion pressures/flows. Existence of the renal RAS in trout was further supported by evidence for angiotensinogen gene expression in kidney as well as liver.
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113
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114
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Brown JA, Carson BW, Gascoyne RD, Cooperberg PL, Connors JM, Mason AC. Low grade gastric MALT Lymphoma: radiographic findings. Clin Radiol 2000; 55:384-9. [PMID: 10816406 DOI: 10.1053/crad.2000.0449] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
AIMS Gastric MALT (mucosa-associated lymphoid tissue) lymphoma is now recognized as a distinct entity within extranodal non-Hodgkin's lymphoma. The purpose of this study was to describe the radiographic findings in low grade gastric MALT lymphoma. MATERIALS AND METHODS We retrospectively reviewed the radiographic findings in 22 cases of low-grade gastric MALT lymphoma. The study group consisted of 15 men and seven women (median age 68 years, range 41-91 years). Lesions were designated as infiltrative or polypoid by consensus of two radiologists. Polypoid lesions were categorized by number and size. Anatomical site within the stomach and presence of transpyloric or oesophagogastric extension was determined for each case. The presence of abdominal lymphadenopathy was categorized as regional or distant. The presence of Helicobacter pylori was determined from endoscopic and surgical biopsies. RESULTS Computed tomography (CT) revealed abnormalities of the stomach in 19 cases of the 21 in which it was performed. There were 14 infiltrative lesions and five polypoid lesions. Of the 14 infiltrative lesions, the mean gastric wall thickness was 2.2 cm (range 0.8-6.0 cm). There were three single and two multiple polypoid lesions (mean size 2.2 cm, range 1. 5-2.7 cm). Transpyloric extension was observed in two cases and oesophagogastric extension in one. Abdominal lymphadenopathy was observed in 10 of 21 patients. Helicobacter pylori was found in 19 of 22 cases (86%). CONCLUSION Low grade B cell gastric MALT lymphomas present with an infiltrative form on CT in about three-quarters of cases and a polypoid pattern in the remainder. Abdominal lymphadenopathy is seen in approximately one-half of cases. There is a high association with Helicobacter pylori.
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115
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116
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Brown JA, Phang PT, Sullivan BJ, Mason AC. Cecocutaneous fistula after remote appendectomy: case report. Can Assoc Radiol J 2000; 51:20-2. [PMID: 10711290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023] Open
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117
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Kelly CE, Kennedy CR, Brown JA. Physiological status of wild European eels (Anguilla anguilla) infected with the parasitic nematode, Anguillicola crassus. Parasitology 2000; 120 ( Pt 2):195-202. [PMID: 10726280 DOI: 10.1017/s0031182099005314] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The effect of the parasitic swimbladder nematode, Anguillicola crassus, on the physiological status of wild European eels (Anguilla anguilla) was investigated during an 18 month survey (February 1995 until September 1996), and compared with that of wild uninfected eels collected over the same time-period. Despite the occurrence of up to 15 blood-feeding adults in the swimbladder lumen of the infected eels and as many as 25 additional larvae in the swimbladder wall, there were no major differences in hormonal, metabolic or osmoregulatory status of the 2 groups of eels. Wild European eels appear to adapt to chronic parasitism with Anguillicola crassus. The possible adverse effects of additional simultaneous stressors are discussed.
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118
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Brown JA, Chua SC, Liu SM, Andrews MT, Vandenbergh JG. Spontaneous mutation in the db gene results in obesity and diabetes in CD-1 outbred mice. Am J Physiol Regul Integr Comp Physiol 2000; 278:R320-30. [PMID: 10666131 DOI: 10.1152/ajpregu.2000.278.2.r320] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Five allelic mutants of the diabetes (db) gene have been previously described in mice and rats causing obesity, infertility, and varying degrees of diabetes. We have identified a new, spontaneous mutation resulting in obesity and diabetes in a colony of CD-1 outbred mice, Mus musculus domesticus. Genetic complementation studies indicated that the new mutation was an allele of the diabetes locus. Sequence analysis of cDNA fragments showed a deletion of one G residue located in exon 12 of the leptin receptor gene. The mutation, Lepr(db-NCSU), results in a frameshift and reduces Lepr transcript levels 10-fold. Mutant mice drank up to four times more water and were up to two times heavier than wild-type mice. Blood glucose and plasma insulin and leptin concentrations were sexually dimorphic among affected mice, suggesting an effect of sex steroids. Mortality of affected males was 100% by 5 mo, whereas affected females survived up to 10 mo of age.
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Norrander JM, deCathelineau AM, Brown JA, Porter ME, Linck RW. The Rib43a protein is associated with forming the specialized protofilament ribbons of flagellar microtubules in Chlamydomonas. Mol Biol Cell 2000; 11:201-15. [PMID: 10637302 PMCID: PMC14768 DOI: 10.1091/mbc.11.1.201] [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: 11/11/2022] Open
Abstract
Ciliary and flagellar microtubules contain a specialized set of three protofilaments, termed ribbons, that are composed of tubulin and several associated proteins. Previous studies of sea urchin sperm flagella identified three of the ribbon proteins as tektins, which form coiled-coil filaments in doublet microtubules and which are associated with basal bodies and centrioles. To study the function of tektins and other ribbon proteins in the assembly of flagella and basal bodies, we have begun an analysis of ribbons from the unicellular biflagellate, Chlamydomonas reinhardtii, and report here the molecular characterization of the ribbon protein rib43a. Using antibodies against rib43a to screen an expression library, we recovered a full-length cDNA clone that encodes a 42,657-Da polypeptide. On Northern blots, the rib43a cDNA hybridized to a 1. 7-kb transcript, which was up-regulated upon deflagellation, consistent with a role for rib43a in flagellar assembly. The cDNA was used to isolate RIB43a, an approximately 4.6-kb genomic clone containing the complete rib43a coding region, and restriction fragment length polymorphism analysis placed the RIB43a gene on linkage group III. Sequence analysis of the RIB43a gene indicates that the substantially coiled-coil rib43a protein shares a high degree of sequence identity with clones from Trypanosoma cruzi and Homo sapiens (genomic, normal fetal kidney, and endometrial and germ cell tumors) but little sequence similarity to other proteins including tektins. Affinity-purified antibodies against native and bacterially expressed rib43a stained both flagella and basal bodies by immunofluorescence microscopy and stained isolated flagellar ribbons by immuno-electron microscopy. The structure of rib43a and its association with the specialized protofilament ribbons and with basal bodies is relevant to the proposed role of ribbons in forming and stabilizing doublet and triplet microtubules and in organizing their three-dimensional structure.
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Brown JA, Slezak JM, Lieber MM, Jenkins RB. Fluorescence in situ hybridization aneuploidy as a predictor of clinical disease recurrence and prostate-specific antigen level 3 years after radical prostatectomy. Mayo Clin Proc 1999; 74:1214-20. [PMID: 10593349 DOI: 10.4065/74.12.1214] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVE To determine if fluorescence in situ hybridization (FISH) analysis of fresh-tissue biopsy specimens obtained at the time of radical prostatectomy is able to predict prospectively clinical disease progression or prostate-specific antigen (PSA) level in patients 3 to 4 years after surgery. MATERIALS AND METHODS FISH analysis was performed on fresh-tissue touch preparations obtained from 90 randomly selected radical prostatectomy specimens. Cut surface touch preparations from 40 specimens resected in 1992 were analyzed with DNA probes for chromosomes 4, 6-12, 17, 18, X, and Y. Needle-biopsy specimens were obtained from 50 tumors resected in 1993, and touch preparations from these specimens were studied with DNA probes for chromosomes 7, 8, 11, and 12. Serum PSA levels and clinicopathologic data were recorded, and each patient was followed up from the time of surgery to determine cancer progression. RESULTS Of 90 patients undergoing radical prostatectomy in 1992 and 1993, 89 returned for follow-up. Three patients received preoperative hormonal therapy, and in 2 patients, antiandrogen therapy was continued postoperatively. Fifteen patients underwent intraoperative orchiectomy immediately after radical prostatectomy, while 9 patients had postoperative adjuvant hormonal therapy. Six patients underwent postoperative radiation therapy. Fourteen patients (15.7%) demonstrated systemic, local, or PSA progression. Only 2 (4.7%) of 43 patients with FISH diploid tumors demonstrated cancer progression. Conversely, 10 (30.3%) of 33 FISH aneuploid and 12 (26.1%) of 46 FISH nondiploid tumors demonstrated cancer progression (P=.004 and P=.006, respectively). Unlike FISH, flow cytometric aneuploidy was not associated with early cancer progression. Elevated preoperative PSA concentration, increased preoperative and postoperative Gleason score, and increased preoperative and postoperative T or N stage were not statistically significantly associated with cancer progression. While chromosome 7 and 8 aneusomies were not statistically associated with cancer progression, 2 of 5 (P=.04) chromosome 12 aneusomic tumors demonstrated cancer progression. CONCLUSION Early (within 4 years) local, systemic, or PSA progression occurred more frequently (P<.05) in radical prostatectomy patients with FISH aneuploid, nondiploid, and chromosome 12 aneusomic tumors. Flow cytometric ploidy status, preoperative serum PSA concentration, and clinical or pathologic grade or stage, including seminal vesicle involvement, margin status, and capsular perforation status, were not associated with early prostate cancer progression in this group of 89 patients. FISH analysis appears to be a useful preoperative tool for predicting aggressive vs indolent prostate cancer.
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121
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Frankel MR, Shapiro MF, Duan N, Morton SC, Berry SH, Brown JA, Burnam MA, Cohn SE, Goldman DP, McCaffrey DF, Smith SM, St Clair PA, Tebow JF, Bozzette SA. National probability samples in studies of low-prevalence diseases. Part II: Designing and implementing the HIV cost and services utilization study sample. Health Serv Res 1999; 34:969-92. [PMID: 10591268 PMCID: PMC1089068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023] Open
Abstract
OBJECTIVE The design and implementation of a nationally representative probability sample of persons with a low-prevalence disease, HIV/AIDS. DATA SOURCES/STUDY SETTING One of the most significant roadblocks to the generalizability of primary data collected about persons with a low-prevalence disease is the lack of a complete methodology for efficiently generating and enrolling probability samples. The methodology developed by the HCSUS consortium uses a flexible, provider-based approach to multistage sampling that minimizes the quantity of data necessary for implementation. STUDY DESIGN To produce a valid national probability sample, we combined a provider-based multistage design with the M.D.-colleague recruitment model often used in non-probability site-specific studies. DATA COLLECTION Across the contiguous United States, reported AIDS cases for metropolitan areas and rural counties. In selected areas, caseloads for known providers for HIV patients and a random sample of other providers. For selected providers, anonymous patient visit records. PRINCIPAL FINDINGS It was possible to obtain all data necessary to implement a multistage design for sampling individual HIV-infected persons under medical care with known probabilities. Taking account of both patient and provider nonresponse, we succeeded in obtaining in-person or proxy interviews from subjects representing over 70 percent of the eligible target population. CONCLUSIONS It is possible to design and implement a national probability sample of persons with a low-prevalence disease, even if it is stigmatized.
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Klaentschi K, Shore AC, Tooke JE, Brown JA. Pressure-permeability relationships in crosslinked basement membranes. Microvasc Res 1999; 58:329-32. [PMID: 10527773 DOI: 10.1006/mvre.1999.2167] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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123
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Brown JA, Tuszynski JA. The possible relationship between cell shape and electric fields. J Theor Biol 1999; 200:245-7. [PMID: 10504289 DOI: 10.1006/jtbi.1999.0984] [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: 11/22/2022]
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Mehl ML, Sarkar DK, Schott HC, Brown JA, Sampson SN, Bayly WM. Equine plasma beta-endorphin concentrations are affected by exercise intensity and time of day. Equine Vet J 1999:567-9. [PMID: 10659319 DOI: 10.1111/j.2042-3306.1999.tb05285.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Eight mature mares were exercised for 20 min at 60% VO2max and to fatigue at 95% VO2max. Plasma beta-endorphin (EN) concentrations were determined before exercise, after a 10 min warm-up, and at the end of each exercise test. Mean +/- s.e. beta-endorphin concentrations were significantly (P < 0.05) higher following work at 95% VO2max when compared to that at 60% VO2max (420.0 +/- 102.7 vs. 269.9 +/- 30.69 pg/ml). Pre-exercise samples were collected between 1000 and 1500 h. In order to evaluate whether any cyclic changes in EN secretion effects may have influenced results, a subsequent study was completed using 12 horses to assess diurnal fluctuations in EN concentrations, by measuring EN concentration every 2 h for a 24 h period. There was no statistical difference in mean values at any time between 0800 and 2000 h. Whether individual differences in EN concentrations reflected varying degrees of stress associated with the exercise could not be determined. Any possible link between EN concentration and exercise stress in exercising horses awaits clarification.
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Abstract
OBJECTIVE To examine associations of patient ratings of communication by health care providers with patient language (English vs Spanish) and ethnicity (Latino vs white). METHODS A random sample of patients receiving medical care from a physician group association concentrated on the West Coast was studied. A total of 7,093 English and Spanish language questionnaires were returned for an overall response rate of 59%. Five questions asking patients to rate communication by their health care providers were examined in this study. All five questions were administered with a 7-point response scale. MAIN RESULTS We estimated the associations of satisfaction ratings with language (English vs Spanish) and ethnicity (white vs Latino) using ordinal logistic models, controlling for age and gender. Latinos responding in Spanish (Latino/Spanish) were significantly more dissatisfied compared with Latinos responding in English (Latino/English) and non-Latino whites responding in English (white) when asked about: (1) the medical staff listened to what they say (29% vs 17% vs 13% rated this "very poor," "poor," or "fair"; p <.01); (2) answers to their questions (27% vs 16% vs 12%; p <.01); (3) explanations about prescribed medications (22% vs 19% vs 14%; p <.01); (4) explanations about medical procedures and test results (36% vs 21% vs 17%; p <.01); and (5) reassurance and support from their doctors and the office staff (37% vs 23% vs 18%; p <.01). CONCLUSION This study documents that Latino/Spanish respondents are significantly more dissatisfied with provider communication than Latino/English and white respondents. These results suggest Spanish-speaking Latinos may be at increased risk of lower quality of care and poor health outcomes. Efforts to improve the quality of communication with Spanish-speaking Latino patients in outpatient health care settings are needed.
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Keegan RD, Greene SA, Brown JA, Weil AB, Bayly WM. Effects of pre-exercise frusemide administration and post exercise anaesthesia on cardiopulmonary and acid-base parameters and blood and plasma volumes in horses exercised supramaximally to fatigue. Equine Vet J 1999:174-7. [PMID: 10659246 DOI: 10.1111/j.2042-3306.1999.tb05212.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Six horses were randomly assigned to receive either frusemide (F) (0.5 mg/kg i.v.) or an equivalent volume of saline (S) i.v., 4 h prior to treadmill exercise. Horses were instrumented to enable measurement of heart rate (HR), systolic (SAP), mean (MAP), and diastolic (DAP) carotid arterial pressures, pulmonary artery pressure (PAP), central venous pressure (CVP), pulmonary arterial temperature (TEMP), blood gases, and cardiac output (CO). Plasma (PV) and blood volumes (BV) were measured using 2 injections of Evan's Blue dye. Baseline parameters were recorded while the horse stood quietly. Horses were then administered F or S. Four hours later, they were warmed up for 3 min at 4 m/s and then exercised to the point of fatigue at 115% VO2max. Horses were anaesthetised immediately following exercise by administration of detomidine (0.04 mg/kg bwt i.v.) followed 5 min later by tiletamine-zolazepam (1.25 mg/kg bwt i.v.). After transporting the horse to a recovery stall, anaesthesia was maintained with isoflurane in 100% O2. Data were analysed using a 2-way ANOVA with repeated measures with post hoc differences identified using the Student-Newman-Keul's procedure. Exercise was associated with increases in HR, SAP, MAP, DAP, PAP, CVP, TEMP, PCV, and BV, and decreases in PV, pH, arterial bicarbonate and base excess. Anaesthesia was associated with marked hypercapnia, a decrease in HR following detomidine administration, and persistent pulmonary hypertension despite carotid arterial pressure which returned to baseline. No effects attributable to F were identified at any time during the study.
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Brown JA, Mason AC, Cooperberg PL. Gastrointestinal manifestations of cystic fibrosis in adults: pictorial essay. Can Assoc Radiol J 1999; 50:165-9. [PMID: 10405648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023] Open
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Brown JA, Coursaget C, Preul MC, Sangvai D. Mercury water and cauterizing stones: Nicolas André and tic douloureux. J Neurosurg 1999; 90:977-81. [PMID: 10223470 DOI: 10.3171/jns.1999.90.5.0977] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
In his 1756 text, Observations pratiques sur les maladies de l'urèthre et sur plusiers faits convulsifs, Nicolas André coined the term "tic douloureux." He believed that this pain originated from compression of facial sensory peripheral nerves. Using scientific observation and experimentation to confirm this hypothesis, he reproduced the tic pain and treated it by using careful efforts to remove adhesions from the nerve with a caustic solution of mercury water. Believing that recurrence of the pain was a result of early closure of the wound, with recompression of the nerve being the direct cause, André prevented recompression by ensuring open wound drainage. André's surgical technique of using cauterizing stones ensured that there was minimal blood loss and little danger of rebleeding and recompression of the nerve by an accumulated blood clot. His case reports include lengthy follow-up periods that documented the benefits of his procedures, which were confirmed by testimonials from uninvolved colleagues. Although remembered for the two words, "tic douloureux," Nicolas André has long been ignored for his prescient treatment and scientific analysis of a disease for which the modern standard of care has only been defined during the last generation.
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Brown JA, Rankin JC. Lack of glomerular intermittency in the river lamprey lampetra fluviatilis acclimated to sea water and following acute transfer to iso-osmotic brackish water. J Exp Biol 1999; 202 (Pt 8):939-46. [PMID: 10085266 DOI: 10.1242/jeb.202.8.939] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Previous studies have suggested that in the lamprey Lampetra fluviatilis, in contrast to teleost fish, all glomeruli are actively filtering. In the present study, we have applied the ferrocyanide technique to obtain more definitive values for the population of filtering nephrons in the lamprey under conditions of high (in fresh water) and low (in sea water) glomerular filtration rate (GFR) and when the branchial osmotic gradient was eliminated by acute transfer of freshwater lampreys to iso-osmotic brackish water. These studies demonstrated that the renal antidiuresis in lampreys acclimated to full-strength sea water does not involve any reduction in the filtering population of glomeruli. Transfer to brackish water significantly reduced GFR and thereby urine flow rate (287+/−23 ml kg-1 24 h-1 in fresh water; 6.9+/−2.5 ml kg-1 24 h-1 in brackish water). In four of the eight fish examined, 100 % of glomeruli remained filtering; in the other four fish, non-filtering glomeruli occurred in patches along the kidney, always associated with an absence of vascular perfusion, which implies possible endocrine/neural control of vascular tone. The numbers of non-filtering glomeruli were always small, and these glomeruli do not appear to make a major contribution to the overall decline in urine output. The results provide firm evidence that although lampreys, like teleosts, show considerable variations in urine output, the renal mechanisms by which lampreys and the teleosts achieve this differ fundamentally, with glomerular intermittency playing little or no part in the lamprey.
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Schmidt L, Junker K, Nakaigawa N, Kinjerski T, Weirich G, Miller M, Lubensky I, Neumann HP, Brauch H, Decker J, Vocke C, Brown JA, Jenkins R, Richard S, Bergerheim U, Gerrard B, Dean M, Linehan WM, Zbar B. Novel mutations of the MET proto-oncogene in papillary renal carcinomas. Oncogene 1999; 18:2343-50. [PMID: 10327054 DOI: 10.1038/sj.onc.1202547] [Citation(s) in RCA: 352] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Hereditary papillary renal carcinoma (HPRC) is characterized by multiple, bilateral papillary renal carcinomas. Previously, we demonstrated missense mutations in the tyrosine kinase domain of the MET proto-oncogene in HPRC and a subset of sporadic papillary renal carcinomas. In this study, we screened a large panel of sporadic papillary renal carcinomas and various solid tumors for mutations in the MET proto-oncogene. Summarizing these and previous results, mutations of the MET proto-oncogene were detected in 17/129 sporadic papillary renal carcinomas but not in other solid tumors. We detected five novel missense mutations; three of five mutations were located in the ATP-binding region of the tyrosine kinase domain of MET. One novel mutation in MET, V1110I, was located at a codon homologous to an activating mutation in the c-erbB proto-oncogene. These mutations caused constitutive phosphorylation of MET when transfected into NIH3T3 cells. Molecular modeling studies suggest that these activating mutations interfere with the intrasteric mechanism of tyrosine kinase autoinhibition and facilitate transition to the active form of the MET kinase. The low frequency of MET mutations in noninherited papillary renal carcinomas (PRC) suggests that noninherited PRC may develop by a different mechanism than hereditary papillary renal carcinoma.
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Petrou SP, Brown JA, Blaivas JG. Suprameatal transvaginal urethrolysis. J Urol 1999; 161:1268-71. [PMID: 10081883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
PURPOSE We describe and assess a method of urethrolysis using a transvaginal suprameatal approach without lateral perforation of the urethropelvic ligament. MATERIALS AND METHODS Between March 1993 and December 1997, 32 consecutive women 32 to 79 years old underwent suprameatal transvaginal urethrolysis at 2 institutions. In all cases anti-incontinence surgery was done previously, including a pubovaginal sling procedure in 12, Marshall-Marchetti-Krantz procedure in 8, Burch colposuspension in 6, modified Pereyra transvaginal urethropexy in 4, and Gittes suspension and anterior repair in 1 each. Of the 32 patients 20 were in urinary retention and 12 had primarily urge and/or irritative voiding symptoms, or urge incontinence. In the patients in urinary retention average maximal detrusor pressure was 41.4 cm. water. In all cases physical examination, cystourethroscopy and video urodynamics were done before suprameatal transvaginal urethrolysis. Obstruction was defined as detrusor pressure greater than 20 cm. water at maximum urinary flow of less than 12 ml. per second. Urethral obstruction was presumed when examination revealed urethral angulation, tethering, narrowing or scarification. Impaired detrusor contractility was diagnosed when detrusor pressure at maximum urinary flow was less than 20 cm. water at maximum urinary flow of less than 12 ml. per second. RESULTS After suprameatal transvaginal urethrolysis 13 of the 20 women (65%) in urinary retention voided well and in 8 of the 12 (67%) with urgency symptoms resolved. Postoperative stress urinary incontinence developed in only 1 case. CONCLUSIONS The success rate of suprameatal transvaginal urethrolysis to treat urinary obstruction associated with anti-incontinence procedures compares favorably to that of other described alternative approaches. The success rate in patients with definite urodynamic criteria for obstruction was not significantly better than in those who underwent suprameatal transvaginal urethrolysis based on physical examination and clinical judgment. Preoperative maximal urinary flow rate was associated with operative success (p = 0.018), while preoperative post-void residual urine and maximum detrusor pressure failed to reveal a difference between operative success and failure.
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Brown JA, Nederend SE, Hays RD, Short PF, Farley DO. Special issues in assessing care of Medicaid recipients. Med Care 1999; 37:MS79-88. [PMID: 10098562 DOI: 10.1097/00005650-199903001-00009] [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: 11/26/2022]
Abstract
OBJECTIVES The authors describe the process used to develop and test survey items targeted to Medicaid consumers for the Consumer Assessment of Health Plans Study (CAHPS). In addition, the authors highlight the special challenges in locating and surveying Medicaid recipients and provide recommendations for increasing response rates. METHODS The RAND CAHPS team reviewed the literature and existing questionnaires to identify health care issues and concepts important to Medicaid consumers. Three focus groups and 66 one-on-one cognitive interviews were conducted to test the relevance of our concepts and items and to identify additional concepts important to Medicaid consumers. After the cognitive interviews, the CAHPS Medicaid consumer survey was field tested using a sample of 930 adults and children receiving both Medicaid and Aid to Families with Dependent Children in Los Angeles County and Oklahoma. To determine if one particular mode were preferable for surveying a Medicaid population, our field test sample was divided randomly into a telephone-mode sample, a mixed-mode sample, and a second telephone-mode sample with enhanced locating procedures. Before finalizing the CAHPS 1.0 surveys, the full CAHPS item set was subjected to a formal literacy review. RESULTS The results of the focus groups and cognitive testing informed iterative versions of the list of concepts addressed by the Medicaid-targeted items. Concepts that were not relevant to Medicaid consumers or that consumers were unable to accurately attribute to a health plan were discarded. New concepts addressing important aspects of health care and the health care experience of Medicaid consumers were identified and added. Item wording and format were revised and refined based on the findings from focus groups, cognitive testing, the field test, and the formal literacy review. In the field test, the mixed-mode method achieved the best results with a 56% completion rate. CONCLUSIONS The testing and formatting efforts described in this article, in combination with a formal literacy review, led to the development of a Medicaid questionnaire that measures the important health care experiences of Medicaid consumers in a format that is "respondent-friendly." Our recommendations for surveying Medicaid recipients can benefit any survey of a Medicaid population.
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Kolls JK, Habetz S, Shean MK, Vazquez C, Brown JA, Lei D, Schwarzenberger P, Ye P, Nelson S, Summer WR, Shellito JE. IFN-gamma and CD8+ T cells restore host defenses against Pneumocystis carinii in mice depleted of CD4+ T cells. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 1999; 162:2890-4. [PMID: 10072538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Host defenses against infection are profoundly compromised in HIV-infected hosts due to progressive depletion of CD4+ T lymphocytes and defective cell-mediated immunity. Although recent advances in antiretroviral therapy can dramatically lower HIV viral load, blood CD4+ T lymphocytes are not restored to normal levels. Therefore, we investigated mechanisms of host defense other than those involving CD4+ T lymphocytes against a common HIV-related opportunistic infection, Pneumocystis carinii (PC) pneumonia. Using CD4-depleted mice, which are permissive for chronic PC infection, we show that up-regulation of murine IFN-gamma by gene transfer into the lung tissue results in clearance of PC from the lungs in the absence of CD4+ lymphocytes. This resolution of infection was associated with a >4-fold increase in recruited CD8+ T lymphocytes and NK cells into the lungs. The role of CD8+ T cells as effector cells in this model was further confirmed by a lack of an effect of IFN-gamma gene transfer in scid mice or mice depleted of both CD4+ and CD8+ T cells. Cytokine mRNA analysis revealed that recruited, lung-derived CD8+ T cells had greater expression of IFN-gamma message in animals treated with the IFN-gamma gene. These results indicate that CD8+ T cells are capable of clearing PC pneumonia in the absence of CD4+ T cells and that this host defense function of CD8+ T cells, as well as their cytokine repertoire, can be up-regulated through cytokine gene transfer.
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Harris-Kojetin LD, Fowler FJ, Brown JA, Schnaier JA, Sweeny SF. The use of cognitive testing to develop and evaluate CAHPS 1.0 core survey items. Consumer Assessment of Health Plans Study. Med Care 1999; 37:MS10-21. [PMID: 10098555 DOI: 10.1097/00005650-199903001-00002] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES The main goal of the Consumer Assessments of Health Plans Study (CAHPS) is to develop an integrated set of tested, standardized surveys to obtain meaningful information from health plan enrollees about their experiences. The CAHPS project benefits from the complementary strengths of psychometric and cognitive testing. METHODS The CAHPS team conducted 150 cognitive interviews across three organizations in different geographic locations using multiple interview methods with different consumer populations. This article explains how cognitive testing was used in the CAHPS survey development process and shares the main findings from the cognitive interviews. RESULTS A modified report format is more appropriate when asking about specific aspects of plan enrollees' experiences, whereas a rating format is useful for asking about overall assessments. Specifying a longer reference period is preferable to asking about the most recent visit when capturing experiences with care, because some respondents get frustrated when they cannot include experiences other than the most recent visit. Explicit screeners and tailored inapplicable response categories are beneficial in mail questionnaires, so people know that they should not answer questions about which they have no relevant experience. CONCLUSION Cognitive testing was integral in the development and refinement of the CAHPS instrument. The cognitive testing findings contributed to an improved instrument that should capture consumers' health care and plan experiences with less response error than one not subjected to such testing. The cognitive testing process and findings can be useful to other researchers with similar survey development goals.
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Scott-Rotter AE, Brown JA. Physician practice management companies: should physicians be scared? THE JOURNAL OF MEDICAL PRACTICE MANAGEMENT : MPM 1999; 14:245-9. [PMID: 10623415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Physician practice management companies (PPMCs) manage nonclinical aspects of physician care and control physician groups by buying practice assets. Until recently, PPMCs were a favorite of Wall Street. Suddenly, in early 1998, the collapse of the MedPartners-PhyCor merger led to the rapid fall of most PPMC stock, thereby increasing wariness of physicians to sell to or invest in PPMCs. This article explores not only the broken promises made by and false assumptions about PPMCs, but also suggests criteria that physicians should use and questions would-be PPMC members should ask before joining. Criteria include: demonstrated expertise, a company philosophy that promotes professional autonomy, financial stability, freedom from litigation, and satisfied physicians already in the PPMC. The authors recommend that physicians seek out relatively small, single-specialty PPMCs, which hold the best promise of generating profits and permitting professional control over clinical decisions.
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Cobb CS, Williamson R, Brown JA. Angiotensin II-induced calcium signalling in isolated glomeruli from fish kidney (Oncorhynchus mykiss) and effects of losartan. Gen Comp Endocrinol 1999; 113:312-21. [PMID: 10082634 DOI: 10.1006/gcen.1998.7209] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Glomeruli were isolated from the kidney of freshwater-adapted rainbow trout, Oncorhynchus mykiss, to qualitatively evaluate changes in cellular calcium associated with angiotensin II ([Asn1Val5]-Ang II) receptor stimulation and antagonism by the Ang II receptor antagonist losartan. Microspectrofluorometry using the fluorescent calcium indicator dye Calcium Green recorded fluorescence changes in isolated single glomeruli. Isolated glomeruli containing ester-loaded Calcium Green showed an Ang-II-induced transient rise in fluorescence. This transient rise showed an increased peak amplitude with increased Ang II concentration (10(-9) to 10(-6) M), but only a very small response was detectable in glomeruli exposed to 10(-9) M Ang II. The biphenylimidazole compound losartan (=DuP 753), an antagonist of the mammalian AT1 subtype Ang II receptor, initiated a transient agonistic rise in glomerular fluorescence at high concentration (10(-5), 10(-4), and 10(-3) M). However, the responses to 10(-6) 10(-7) M losartan were small or very low in each case. Losartan (10(-4) or 10(-7) M) antagonised the Ang-II-induced signalling in isolated glomeruli exposed to 10(-7) or 10(-6) M Ang II, respectively. This is the first evidence for functional AT1-like Ang II receptors coupled to cellular calcium signalling in the glomeruli of rainbow trout.
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Brown JA, Woodward CA, Shannon HS, Cunningham CE, Lendrum B, McIntosh J, Rosenbloom D. Determinants of job stress and job satisfaction among supervisory and non-supervisory employees in a large Canadian teaching hospital. Healthc Manage Forum 1999; 12:27-33. [PMID: 10538924 DOI: 10.1016/s0840-4704(10)60688-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
This article explores the extent to which hospital workers at a large teaching hospital at different managerial/supervisory levels (designated and non-designated supervisors, and non-supervisory staff), experienced job stress and job satisfaction prior to the re-engineering of hospital services. For all groups, increased levels of job demands were associated with higher levels of stress. Lower levels of decision latitude were associated with increased job stress for designated supervisors. Increasing levels of decision latitude were associated with both job stress and satisfaction for the other two groups. Co-worker support and teamwork contributed to increased job satisfaction for all groups.
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Carson BW, Brown JA, Cooperberg PL. Ultrasonographically guided percutaneous biopsy of gastric, small bowel, and colonic abnormalities: efficacy and safety. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 1998; 17:739-742. [PMID: 9849945 DOI: 10.7863/jum.1998.17.12.739] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The purposes of this study were to evaluate the efficacy of sonographically guided percutaneous biopsy of gastric and bowel lesions and to document any associated complications. A retrospective review of all patients undergoing ultrasonographically guided biopsy of gastric, small bowel, or colonic lesions was performed. Cases were evaluated for size of lesion, location, efficacy in obtaining a diagnostic specimen, and any procedure-related complications. A total of 46 biopsies were performed in 44 patients over a 6 year period. Fifteen gastric, four duodenal, seven small bowel, 16 right colonic, and two left colonic lesions were identified. Histologic diagnosis included 20 adenocarcinomas, seven lymphomas, 10 mesenchymal tumors, and two cases of candidal enteritis. In 18 (41%) patients the initial fine-needle aspirate was negative, although 10 of these patients subsequently underwent ultrasonographically guided core biopsy with a diagnosis of neoplasm established in all 10. Two patients with an initial negative result on fine-needle aspiration underwent repeat aspiration, demonstrating malignancy. Two additional false-negative aspirates were obtained; these patients did not undergo repeat biopsy but were subsequently found to have lymphoma. Two of the patients with aspirates that were negative for malignancy were believed to have inflammatory changes secondary to pancreatitis. One patient was lost to follow-up evaluation. No complications were recorded. Percutaneous fine-needle aspiration of gastric and bowel lesions is a simple and safe procedure and may be particularly useful with poor candidates for endoscopy or for lesions that are difficult or impossible to reach endoscopically. Diagnostic yield is high, particularly in documenting malignancy, although in suspected stromal tumors a core biopsy often is required.
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Burns JC, Capparelli EV, Brown JA, Newburger JW, Glode MP. Intravenous gamma-globulin treatment and retreatment in Kawasaki disease. US/Canadian Kawasaki Syndrome Study Group. Pediatr Infect Dis J 1998; 17:1144-8. [PMID: 9877364 DOI: 10.1097/00006454-199812000-00009] [Citation(s) in RCA: 293] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To determine the prevalence and outcome of intravenous gamma-globulin (IVIG) retreatment in patients with Kawasaki disease (KD). METHOD Multicenter, retrospective survey of all children with KD evaluated at nine clinical centers across North America during a 15-month period. RESULTS Data were available for 378 patients. At 48 h after completion of the initial IVIG infusion, 50 patients (13.2%) remained febrile, 29 (58.0%) of whom were retreated with IVIG, including 4 (13.8%) with coronary artery abnormalities before their first IVIG infusion. Among 25 retreated patients with a normal baseline echocardiogram, 5 (20.0%) developed coronary abnormalities and were termed "treatment failures." Among the 323 patients with a normal baseline echocardiogram, only 9 (2.8%) were treatment failures; treatment failure occurred in 4 of 282 (1.4%) patients who became afebrile post-IVIG and in 5 of 41 (12.2%) patients with persistent or recrudescent fever after their first course of IVIG therapy (P=0.002). CONCLUSIONS The overall prevalence of new coronary abnormalities in KD patients treated with IVIG and aspirin remains low. Persistent or recrudescent fever after the first course of IVIG was associated with an increased risk of treatment failure (P=0.002). IVIG retreatment in patients who remain febrile after the first course of IVIG is now common (58.0%), although the efficacy of this practice requires assessment with a randomized trial.
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Weissman JD, Brown JA, Howcroft TK, Hwang J, Chawla A, Roche PA, Schiltz L, Nakatani Y, Singer DS. HIV-1 tat binds TAFII250 and represses TAFII250-dependent transcription of major histocompatibility class I genes. Proc Natl Acad Sci U S A 1998; 95:11601-6. [PMID: 9751712 PMCID: PMC21687 DOI: 10.1073/pnas.95.20.11601] [Citation(s) in RCA: 114] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
HIV Tat, a transactivator of viral transcription, represses transcription of major histocompatibility (MHC) class I genes. Repression depends exclusively on the C-terminal domain of Tat, although the mechanism of this repression has not been known. We now show that repression results from the interaction of Tat with the TAFII250 component of the general transcription factor, TFIID. The C-terminal domain of Tat binds to a site on TAFII250 that overlaps the histone acetyl transferase domain, inhibiting TAFII250 histone acetyl transferase activity. Furthermore, promoters repressed by Tat, including the MHC class I promoter, are dependent on TAFII250 whereas those that are not repressed by Tat, such as SV40 and MuLV promoters, are independent of functional TAFII250. Thus, Tat repression of MHC class I transcription would be one mechanism by which HIV avoids immune surveillance.
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Brown JA, Rogers EM, Boss JM. The MHC class II transactivator (CIITA) requires conserved leucine charged domains for interactions with the conserved W box promoter element. Nucleic Acids Res 1998; 26:4128-36. [PMID: 9722631 PMCID: PMC147839 DOI: 10.1093/nar/26.18.4128] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The class II transactivator CIITA is required for transcriptional activation of the major histocompatibility complex (MHC) class II genes. Aside from an N-terminal acidic transcriptional activation domain, little is known about how this factor functions. Extensive mutagenesis of CIITA was undertaken to identify structural motifs required for function. The ability of mutants to activate a reporter gene under the control of MHC class II conserved W-X-Y or X-Y regulatory elements was determined. Two mutants displayed differential activity between the two promoters, activating transcription with the W-X-Y but not the X-Y elements. All mutants were tested for their ability to interfere with wild-type CIITA activity. Five CIITA mutant constructions were able to down-regulate wild-type CIITA activity. Three of these mutants contained targeted disruptions of potential functional motifs: the acidic activation domain, a putative GTP-binding motif and two leucine charged domains (LCD motifs). The other two contained mutations in regions that do not have homology to described proteins. The characterization of CIITA mutants that are able to discriminate between promoters with or without the W box strongly suggests that CIITA requires such interactions for function. The identification of LCD motifs required for CIITA function brings to light a previously undefined role of these motifs in CIITA function.
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Mahalick DM, Carmel PW, Greenberg JP, Molofsky W, Brown JA, Heary RF, Marks D, Zampella E, Hodosh R, von der Schmidt E. Psychopharmacologic treatment of acquired attention disorders in children with brain injury. Pediatr Neurosurg 1998; 29:121-6. [PMID: 9838263 DOI: 10.1159/000028705] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
This investigation examined the efficacy of psychostimulant therapy in alleviating neurobehavioral dysfunction attendant to pediatric brain injury. The most commonly reported neurobehavioral sequelae associated with head injury in the pediatric population involve deficits along the attentional matrix. This is also the most common objectively documented neurobehavioral finding among children as well as adults. There are several investigations in the adult literature which have employed the use of psychostimulants in treating both psychiatric and neuropsychological residua associated with head injury. Overall, the results of these studies are equivocal, but suggest a beneficial impact on general functioning. The present prospective investigation utilized a double-blind, placebo-controlled, cross-over experimental design to examine the efficacy of methylphenidate in treating children with acquired attentional disorders secondary to brain injury. A cohort of 14 children with varying degrees of head injury were recruited for participation. As expected, differences between drug and placebo conditions uniformly achieved statistical significance. Additionally, there were no differences in performance between baseline and placebo conditions on neurobehavioral tasks of attention and concentration. Current findings suggest that methylphenidate (and probably other psychostimulants such as Cylert, Adderal, Wellbutrin and dextroamphetamine sulfate) is an extremely effective agent in treating attentional disorders secondary to brain injury in children.
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Brown JA, Nehra A. Erythropoietin-induced recurrent veno-occlusive priapism associated with end-stage renal disease. Urology 1998; 52:328-30. [PMID: 9697807 DOI: 10.1016/s0090-4295(98)00191-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This is the first report of a male hemodialysis patient experiencing recurrent dialysis-associated priapism that resolved when his concurrent erythropoietin dose was reduced from 2000 to 1500 U one time per week and held if his hemoglobin was greater than 10 g/dL. We discuss dialysis-associated priapism and the effects of erythropoietin on the coagulation cascade and male hormone levels in an effort to elucidate the etiology of priapism in this patient.
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Jackson CA, Brown JA, Relles DA, Lee PP. Work time estimates for ophthalmic diagnoses and procedures. Results from the Eye Care Workforce Study. ARCHIVES OF OPHTHALMOLOGY (CHICAGO, ILL. : 1960) 1998; 116:922-8. [PMID: 9682707 DOI: 10.1001/archopht.116.7.922] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVE To provide estimates of patient-level annual ophthalmologist work times for the care of common ophthalmic conditions and patient-level global surgical care time for common or important ophthalmic procedures. METHODS A random sample of the domestic membership (excluding members-in-training) of the American Academy of Ophthalmology, stratified by self-designated practice concentration, was surveyed in 1994 to provide estimates of work times for common ophthalmic services. RESULTS Comprehensive and subspecialty-specific results were obtained for ophthalmic diagnoses, services, and surgical procedures. For ophthalmic diagnoses and services, initial and follow-up visit work times are reported for comprehensive and subspecialty ophthalmologists separately. For common surgical procedures, aggregate results based on comprehensive and subspecialist survey responses are reported. CONCLUSIONS These ophthalmology-specific survey results can be used for a variety of purposes, including practice management, "benchmarking," health plan administration and national workforce planning. Such surveys should be repeated as techniques and practice patterns change over time.
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Brown JA, Abelson J, Woodward CA, Hutchison B, Norman G. Fielding standardized patients in primary care settings: lessons from a study using unannounced standardized patients to assess preventive care practices. Int J Qual Health Care 1998; 10:199-206. [PMID: 9661058 DOI: 10.1093/intqhc/10.3.199] [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: 11/13/2022] Open
Abstract
OBJECTIVES To document detection and suspicion rates of unannounced standardized patients visiting community-based practices. DESIGN Primary care physicians were recruited to participate in a study using standardized patients. Four standardized patient scenarios were used. SETTING Community-based primary care physicians' practices in southern Ontario between September 1994 and August 1995. STUDY PARTICIPANTS Sixty-two primary care physicians. MAIN OUTCOME MEASURES A 'believability' questionnaire completed after all four standardized patients had visited the practices. RESULTS Of the primary care physicians approached, 50% (62) agreed to participate. Twenty-one per cent of all visits were suspected as standardized patient encounters. Forty-six per cent suspected one or more standardized patients. Only five physicians (8%) suspected all four standardized patients. Reasons for suspecting standardized patients were associated with the characteristics of the physician's practices, the physician's practice profile and the standardized patient cover story. CONCLUSION The portrayal of asymptomatic patients seeking a new primary care physician presents unique challenges. Carefully constructed cover stories, and detailed knowledge of the local area and of the practices of the participating physicians is required to allow standardized patients cases to be tailored to fit into primary care settings without arousing suspicion.
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Wright KL, Chin KC, Linhoff M, Skinner C, Brown JA, Boss JM, Stark GR, Ting JP. CIITA stimulation of transcription factor binding to major histocompatibility complex class II and associated promoters in vivo. Proc Natl Acad Sci U S A 1998; 95:6267-72. [PMID: 9600954 PMCID: PMC27653 DOI: 10.1073/pnas.95.11.6267] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
CIITA is a master transactivator of the major histocompatibility complex class II genes, which are involved in antigen presentation. Defects in CIITA result in fatal immunodeficiencies. CIITA activation is also the control point for the induction of major histocompatibility complex class II and associated genes by interferon-gamma, but CIITA does not bind directly to DNA. Expression of CIITA in G3A cells, which lack endogenous CIITA, followed by in vivo genomic footprinting, now reveals that CIITA is required for the assembly of transcription factor complexes on the promoters of this gene family, including DRA, Ii, and DMB. CIITA-dependent promoter assembly occurs in interferon-gamma-inducible cell types, but not in B lymphocytes. Dissection of the CIITA protein indicates that transactivation and promoter loading are inseparable and reveal a requirement for a GTP binding motif. These findings suggest that CIITA may be a new class of transactivator.
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Brown JA, Elliott DS, Barrett DM. Postprostatectomy urinary incontinence: a comparison of the cost of conservative versus surgical management. Urology 1998; 51:715-20. [PMID: 9610584 DOI: 10.1016/s0090-4295(98)00123-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVES Post-radical prostatectomy stress incontinence occurs in up to 20% of patients. Postprostatectomy incontinence is initially treated with undergarments, pads, or drip collectors. Patients with persistent leakage are often treated with a transurethral bulking agent (Contigen) or placement of an artificial genitourinary sphincter (AGUS). We have compared the direct costs of each treatment at our institution over 10 years. METHODS The Mayo Clinic estimating office provided the Medicare and non-Medicare charges for patients receiving both collagen injection (outpatient) and AGUS placement (2-day hospitalization) during August 1995. The Mayo Store provided the current price of all undergarments, pads, and drip collectors carried. Two local grocery stores provided the cost of Depends undergarments. RESULTS The following items were the least expensive carried at the Mayo Clinic Store: Entrust undergarments, Active Style pads, and Conveen drip collectors at $0.99, $0.52, $1.05 each, respectively. The average cost of Depends undergarments was $0.52 each. The cost of wearing 5 of the least expensive undergarments or pads per day for 10 years is $9497. The average estimated Medicare and non-Medicare cost for outpatient (general anesthesia) collagen injection is $4300 and $5625, respectively. The average Medicare and non-Medicare cost for AGUS placement is $15,400 and $20,300, respectively. Factoring in our current 22.4% reoperation rate, the average per patient Medicare and non-Medicare cost for AGUS placement is $18,850 and $24,847, respectively. CONCLUSIONS The cost of the AGUS placement compares favorably with the cost of transurethral collagen injection (under general anesthesia) in patients requiring several (more than three) collagen injection treatments or requiring the continued use of undergarments after collagen injection. Whereas the cost of transurethral collagen injection, when effective, compares favorably with conservative treatment, AGUS placement is significantly more expensive than conservative management for almost all patients except the exceedingly rare patient wearing more than 9 undergarments or pads per day. When the psychosocial benefit of urinary continence is considered, however, transurethral injection of collagen or AGUS placement often becomes the preferred treatment.
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Hays RD, Brown JA, Spritzer KL, Dixon WJ, Brook RH. Member ratings of health care provided by 48 physician groups. ARCHIVES OF INTERNAL MEDICINE 1998; 158:785-90. [PMID: 9554685 DOI: 10.1001/archinte.158.7.785] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND Satisfaction with health plan performance has been assessed frequently, but assessment of physician group performance is rare. OBJECTIVE To present ratings of the care provided by physician groups to enrollees in a variety of capitated health maintenance organization plans. METHODS A random sample was drawn of adult enrollees receiving managed health care from 48 physician groups in a group practice association. Each individual in the sample was mailed a 12-page questionnaire and 7093 were returned (59% response rate). The mean age of those returning the questionnaire was 51 years; 65% were women. RESULTS Reliability estimates for 6 multi-item satisfaction scales were excellent, and noteworthy differences in ratings among groups were observed. In particular, ratings of overall quality ranged from a low of 28 to a high of 68 (mean, 50; SD, 10). Average scores for physician groups were strongly correlated across all scales, but no single group scored consistently highest or lowest on the different scales. Negative ratings of care were significantly related to the following: intention to switch to another physician group, difficulty in getting appointments, lengthy waiting periods in the reception area and examination room, the inability to get consistent care from one physician for routine visits, and not being informed by the office staff when there was a delay in seeing the primary care provider. CONCLUSIONS Monitoring of health care quality at the physician group level is possible, and could be used for benchmarking, internal quality improvement, and for providing information to the public about how these physician groups will meet its needs.
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Grandjean PW, Crouse SF, O'Brien BC, Rohack JJ, Brown JA. The effects of menopausal status and exercise training on serum lipids and the activities of intravascular enzymes related to lipid transport. Metabolism 1998; 47:377-83. [PMID: 9550532 DOI: 10.1016/s0026-0495(98)90046-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The study purpose was to compare the effect of exercise training on serum lipid and apolipoprotein concentrations and the activities of intravascular enzymes related to lipid transport in previously untrained eumenorrheic, premenopausal (PRM) women (n = 21; mean age, 36 +/- 3 years) and estrogen-free postmenopausal (POM) women (n = 16; mean age, 68 +/- 8 years). Subjects trained at a progressive intensity and duration (50% to 75% maximal O2 consumption [VO2max], 200 to 300 kcal/session) 4 d/wk for 12 weeks. Before and after training, VO2max, body weight, relative body fat, and fasting blood samples were obtained following 2 weeks on a standardized diet designed to maintain body weight and during the early follicular stage for the PRM group. Blood samples were analyzed for serum total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), the cholesterol content of the HDL3 subfraction, apolipoprotein (apo)A-I and apoB, lipoprotein(a), and the activity of lecithin:cholesterol acyltransferase (LCAT). Total and hepatic triglyceride lipase activity (HTGLA) were determined from plasma samples obtained after heparin administration. The cholesterol content of the low-density lipoprotein (LDL) and HDL2 subfractions and endothelial-bound lipoprotein lipase activity (LPLA) were calculated. A two (group) x two (time) multivariate ANOVA (MANOVA), with repeated measures for time indicated that the exercise-induced changes in physiological measurements, serum lipid or apolipoprotein concentrations, or enzyme activities did not differ between groups. Serum concentrations of TC, LDL-C, and HDL3 cholesterol, TG, and apo A-I and apoB were higher in POM women compared with the PRM group (P < .05 for all). For the combined groups, body weight and relative body fat did not change with training, but VO2max increased an average of 18.5% (P < .05). LPLA, HTGLA, and LCAT activity were unaltered with exercise training. Except for a small but significant decrease in HDL-C (-5.5%) and an elevation in apoB (4.3%; P < .05 for both), the concentrations of serum lipids and apolipoproteins did not change over the training period. We conclude that in previously untrained women, menopausal status does not influence the exercise training response of serum lipids or apolipoproteins or activities of intravascular enzymes related to lipid transport.
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Klaentschi K, Brown JA, Niblett PG, Shore AC, Tooke JE. Pressure-permeability relationships in basement membrane: effects of static and dynamic pressures. THE AMERICAN JOURNAL OF PHYSIOLOGY 1998; 274:H1327-34. [PMID: 9575938 DOI: 10.1152/ajpheart.1998.274.4.h1327] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The glomerular basement membrane (GBM) is an important component of the filtration barrier that is the glomerular capillary wall. Previously GBM permeability has been investigated only under static pressures and often within a supraphysiological range. We used Matrigel as a model of GBM and formed membranes at the base of filtration chamber. We measured membrane permeability under static and dynamic pressures. Matrigel membranes were size and charge selective toward neutrally and negatively charged dextrans. Their permeability (as measured by hydraulic conductivity) was found to decrease from 1.61 +/- 0.06 to 0.75 +/- 0.07 x 10(-6) cm.s-1.cmH2O-1 as static pressure increased from 6 to 78 cmH2O, an effect attributed to membrane compression. In comparison to static pressure, sinusoidal pressure waves with a mean pressure of 50 cmH2O decreased membrane permeability, e.g., fluid flux was reduced by a maximum of 2% to a value of 5.47 +/- 0.38 x 10(-5) cm/s; albumin clearance was reduced by a maximum of 5.2% to a value of 9.63 +/- 1.06 x 10(-6) ml.cm-2.s-1. Such changes were affected by the frequency of pressure wave application and could be attributed to a switching on and off of the membrane compression effect.
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