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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: 2120] [Impact Index Per Article: 92.2] [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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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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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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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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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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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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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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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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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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