126
|
Dorrell N, Spencer S, Foulonge V, Guigue-Talet P, O'Callaghan D, Wren BW. Identification, cloning and initial characterisation of FeuPQ in Brucella suis: a new sub-family of two-component regulatory systems. FEMS Microbiol Lett 1998; 162:143-50. [PMID: 9595675 DOI: 10.1111/j.1574-6968.1998.tb12991.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
To cause disease, Brucella species have to adapt to a range of different environments. Environmental sensing and adaptive responses in bacteria often involve the concerted action of a two-component regulatory system, consisting of sensor and response regulator components. Amplification and sequence analysis of response regulators from Brucella species identified a response regulator sequence with 96% similarity to Rhizobium leguminosarum FeuP. In R. leguminosarum, the FeuPQ two-component system is involved in the regulation of iron uptake. A Brucella suis feuP isogenic mutant was constructed but was not attenuated in the murine brucellosis model. The survival and multiplication of the mutant in macrophages was also unaffected. The FeuPQ regulon represents a newly characterised sub-family of response regulators.
Collapse
|
127
|
King D, Spencer S, Bronen R, Spencer D. EEG findings in patients with hippocampal atrophy. Neurology 1998. [DOI: 10.1212/wnl.50.5.1515-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
128
|
Burris HA, Vogel CL, Castro D, Mishra L, Schwarz M, Spencer S, Oakes DD, Korey A, Orenberg EK. Intratumoral cisplatin/epinephrine-injectable gel as a palliative treatment for accessible solid tumors: a multicenter pilot study. Otolaryngol Head Neck Surg 1998; 118:496-503. [PMID: 9560102 DOI: 10.1177/019459989811800412] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Intratumoral injections of cisplatin/epinephrine-injectable gel were administered weekly for 4 weeks in 45 patients with malignant tumors of various histologic types. Tumors were located on the skin and subcutaneous tissue primarily of the head, neck, and trunk, and on the tongue, oral pharynx, and esophagus. Patients were not candidates for surgery, radiation, or systemic chemotherapy. Each of the treated tumors (n = 82) was evaluated 2, 4, 8, and 12 weeks after the final injection. The initial dose of cisplatin was 1 mg/cm3 tumor volume, with escalation to 6 mg/cm3 allowed, depending on observed toxicities. The mean cumulative dose per patient for the four treatments ranged from 0.56 to 380 mg cisplatin. No dose-limiting cisplatin-related toxicities, such as nephrotoxicity, neurotoxicity, or ototoxicity, were observed. The overall objective tumor response rate was 50% (41 of 82), with 40% (33 of 82) complete responses and a median response duration of 160 days. Complete responses for adenocarcinoma and squamous cell carcinoma were 58% (21 of 36) and 38% (12 of 32), respectively. These results justified further clinical trials to evaluate the role of local chemotherapy with intratumoral cisplatin/epinephrine-injectable gel in the palliative treatment of patients with selected accessible solid tumors.
Collapse
|
129
|
Waghorn DJ, Tucker PK, Chia Y, Spencer S, Luzzi GA. Collaborative approach to improve the detection and management of trichomoniasis in a low prevalence district. Int J STD AIDS 1998; 9:164-7. [PMID: 9530903 DOI: 10.1258/0956462981921792] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We describe a simple collaborative approach developed by the departments of cytology, microbiology and genitourinary (GU) medicine for the detection, diagnosis and management of microbiologically confirmed Trichomonas vaginalis (TV) infection. Over a 2-year period, 54 (0.1%) of 52,440 cervical smears were reported to show TV, but microbiological confirmation was made in only 76% of 34 patients from whom a vaginal swab was subsequently taken. Trichomoniasis should not be diagnosed by cytology alone and clinicians need further education on the role of cytology in diagnosing sexually transmitted diseases (STDs). Over the same period, from a total of 96 cases of TV identified in the district, only 12 (13%) were first diagnosed in the department of GU medicine. Forty per cent of the other 84 patients were subsequently seen in the GU clinic for test of cure, contact tracing and screening for other STDs. Collaborations between departments may improve the management of trichomoniasis and other conditions in the community and their development should be encouraged.
Collapse
|
130
|
Dowbenko D, Spencer S, Quan C, Lasky LA. Identification of a novel polyproline recognition site in the cytoskeletal associated protein, proline serine threonine phosphatase interacting protein. J Biol Chem 1998; 273:989-96. [PMID: 9422760 DOI: 10.1074/jbc.273.2.989] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Protein-protein interactions are often mediated by the recognition of proline-rich domains by SH3 or WW modules. Previously, we demonstrated that the PEST-type protein-tyrosine phosphatase, PTP HSCF (hematopoietic stem cell fraction), bound to a novel cytoskeletal associated protein, proline serine threonine phosphatase interacting protein (PST PIP), via an interaction between the proline-rich COOH terminus of the PTP and a site within the putative coiled-coil domain of PST PIP. Here we describe a more detailed analysis of this interaction. Earlier data suggested that the NH2 terminus of PST PIP was important for binding to the phosphatase, and deletion of the NH2-terminal 50 amino acids of the PST PIP resulted in an apparently misfolded protein that was incapable of binding PTP HSCF. To examine the region involved with binding to PTP HSCF, alanine-scanning mutants were produced at intervals throughout PST PIP. This analysis demonstrated that a tryptophan at position 232 was essential for binding in vitro. Transfection experiments demonstrated that the Trp232 mutant protein was capable of association with the cortical cytoskeleton but was not bound to PTP HSCF in vivo. Alanine scanning of a peptide derived from the COOH-terminal proline-rich domain of PTP HSCF revealed that a subset of prolines, as well as other residues, was required for efficient binding to PST PIP, and introduction of alanines at some of these positions in the protein resulted in decreased binding to PST PIP in vitro and in vivo. Analysis of in vivo tyrosine phosphorylation of the Trp232 mutant of PST PIP in the presence of v-Src revealed that this protein was phosphorylated more efficiently than the wild-type molecule. Thus, the interaction between PTP HSCF and PST PIP is mediated by a novel site in the cytoskeletal associated protein which interacts with residues within the proline-rich COOH terminus of the phosphatase.
Collapse
|
131
|
Abstract
This qualitative descriptive study explored nurses' views of patient advocacy. Seventeen hospital and community nurses were interviewed to determine whether and how they exercise the advocacy role and what they believe promotes or impedes the practice of advocacy. Findings suggested that the advocacy role was not uppermost in the minds of many of the respondents. However, when queried, the nurse-patient relationship emerged as a salient feature of advocacy; teaching, informing, and supporting were frequent activities of nurses in what they described as advocacy; and interpersonal relatedness, rather than issues of accountability and ethics, were central to the advocacy process. Work environment barriers--such as time, economics, acuity, and power hierarchies--combined with factors, such as lack of autonomy and fatigue, to create reasons not to advocate. Physicians contributed to nurses' willingness or unwillingness to advocate depending on their availability, openness to patients and nurses, and their personal demeanor. A conceptual model of client advocacy emerged from the data to guide further explorations of advocacy. The advocacy role is a critical, perhaps unique dimension of professional nursing that is changing rapidly and may be diverging from the usual role prescribed in the professional literature and taught in baccalaureate nursing curricula.
Collapse
|
132
|
Detoledo-Morrell L, Sullivan MP, Morrell F, Wilson RS, Bennett DA, Spencer S. Alzheimer's disease: in vivo detection of differential vulnerability of brain regions. Neurobiol Aging 1997; 18:463-8. [PMID: 9390771 DOI: 10.1016/s0197-4580(97)00114-0] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The severe cognitive impairment during the later stages of Alzheimer's disease is usually preceded by a selective disturbance in the ability to remember new experiences. With quantitative, high-resolution magnetic resonance imaging techniques, it is now possible to determine, in vivo, differences in the pattern of anatomical changes that might reflect behavioral symptomatology during different stages of the disease. In the present investigation, magnetic resonance imaging examinations were carried out in aged controls and in clinically diagnosed Alzheimer's disease patients who were divided into three groups based upon dementia severity. Atrophy of the hippocampal formation, a region important for memory function, was observed even in Alzheimer's disease patients with the mildest dementia. With more prominent dementia, atrophy extended to the parahippocampal gyrus and the temporal neocortex.
Collapse
|
133
|
Spencer S, Dowbenko D, Cheng J, Li W, Brush J, Utzig S, Simanis V, Lasky LA. PSTPIP: a tyrosine phosphorylated cleavage furrow-associated protein that is a substrate for a PEST tyrosine phosphatase. J Cell Biol 1997; 138:845-60. [PMID: 9265651 PMCID: PMC2138048 DOI: 10.1083/jcb.138.4.845] [Citation(s) in RCA: 147] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/1997] [Revised: 06/06/1997] [Indexed: 02/05/2023] Open
Abstract
We have investigated proteins which interact with the PEST-type protein tyrosine phosphatase, PTP hematopoietic stem cell fraction (HSCF), using the yeast two-hybrid system. This resulted in the identification of proline, serine, threonine phosphatase interacting protein (PSTPIP), a novel member of the actin- associated protein family that is homologous to Schizosaccharomyces pombe CDC15p, a phosphorylated protein involved with the assembly of the actin ring in the cytokinetic cleavage furrow. The binding of PTP HSCF to PSTPIP was induced by a novel interaction between the putative coiled-coil region of PSTPIP and the COOH-terminal, proline-rich region of the phosphatase. PSTPIP is tyrosine phosphorylated both endogenously and in v-Src transfected COS cells, and cotransfection of dominant-negative PTP HSCF results in hyperphosphorylation of PSTPIP. This dominant-negative effect is dependent upon the inclusion of the COOH-terminal, proline-rich PSTPIP-binding region of the phosphatase. Confocal microscopy analysis of endogenous PSTPIP revealed colocalization with the cortical actin cytoskeleton, lamellipodia, and actin-rich cytokinetic cleavage furrow. Overexpression of PSTPIP in 3T3 cells resulted in the formation of extended filopodia, consistent with a role for this protein in actin reorganization. Finally, overexpression of mammalian PSTPIP in exponentially growing S. pombe results in a dominant-negative inhibition of cytokinesis. PSTPIP is therefore a novel actin-associated protein, potentially involved with cytokinesis, whose tyrosine phosphorylation is regulated by PTP HSCF.
Collapse
|
134
|
Naumann RW, Spencer S. An umbilical metastasis after laparoscopy for squamous cell carcinoma of the cervix. Gynecol Oncol 1997; 64:507-9. [PMID: 9062161 DOI: 10.1006/gyno.1996.4600] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Laparoscopic surgical techniques are being used with increasing frequency in patients with gynecologic malignancies. Abdominal wall metastases to trochar sites have been described after treatment for ovarian cancer and other adenocarcinomas but are very rare in patients with squamous cell carcinomas. We present a case of metastasis to a laparoscopic trochar site in a patient with squamous cell carcinoma of the uterine cervix. While this may be an unusual event, there is some concern that laparoscopy could disseminate otherwise isolated pelvic disease.
Collapse
|
135
|
Foster AVM, Spencer S, Edmonds ME. Deterioration of diabetic foot lesions under hydrocolloid dressings. ACTA ACUST UNITED AC 1997. [DOI: 10.1002/pdi.1960140213] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
136
|
Meredith R, Salter M, Kim R, Spencer S, Weppelmann B, Rodu B, Smith J, Lee J. Sucralfate for radiation mucositis: results of a double-blind randomized trial. Int J Radiat Oncol Biol Phys 1997; 37:275-9. [PMID: 9069297 DOI: 10.1016/s0360-3016(96)00531-7] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
PURPOSE To determine if addition of the ulcer-coating polysaccharide sucralfate could improve symptomatic relief of radiation mucositis over a popular combination of antacid, diphenhydramine, and viscous lidocaine alone. METHODS AND MATERIALS A double-blind study was conducted in which nurses and pharmacists coded patient groups and distributed medication in a manner blinded to both the patients and physicians. Eligible patients receiving radiation to the head and neck and/or chest sites that included the esophagus were randomized to a standard combination of antacid, diphenhydramine, and viscous lidocaine vs. the same solution plus sucralfate. Eligible patients were those receiving >40 Gy at 1.8 Gy/fraction, one fraction/day, five fractions/week. Participating patients were stratified between chest, small field head and neck, and large field head and neck. The patients subjective evaluation of throat soreness and relief with medication was elicited as well as physician observations and smears for Candidiasis screening. Medication was prescribed when the patient became symptomatic and concomitant use of other locally effective nonstudy agents was not allowed. The ability to eat various consistency of foods was graded 0-5, with 5 indicating no compromise of ability to ingest a food compared to baseline. Statistical analysis included mean + SD for food and soreness scores, paired t-test, and two-way analyses of variance to evaluate effects of site and treatment group on the changes in scores. RESULTS Over 2 years, 111 patients were entered. Because some withdrew and others did not require medication, results are presented for evaluable patients in each category. Mild adverse effects from the medication solution (usually mouth discomfort) were reported by <10% of patients in each treatment group among 106 patients evaluable for toxicity. There was a comparable incidence of mild-moderate mucositis for the two treatment groups. Severe mucositis was noted in two patients of the standard medication group and none among patients receiving sucralfate. The groups were comparable for indicators including degree of soreness, dietary changes, and objective measures or mucosal irritation or infection. For the head and neck patients there was a significant worsening in soreness and in the ability to eat in both treatment groups, whereas patients treated to the chest had less nutritional change. Multivariate analysis including control for confounding factors did not detect treatment effects for any of the response measures. No patient had occult fungal infection detected by oral pathology evaluation of routine mucosal scrapings. CONCLUSIONS A trend (that was not statistically significant) of less severe radiation mucositis was noted for patients receiving sucralfate in addition to the combination of viscous lidocaine, diphenhydramine, and antacid for nonulcerative radiation mucositis.
Collapse
|
137
|
Morgan JM, Palmisano M, Piraino A, Hirschhorn W, Spencer S, Prasad PP, Ortiz M, Lloyd P. The effect of valsartan on the angiotensin II pressor response in healthy normotensive male subjects. Clin Pharmacol Ther 1997; 61:35-44. [PMID: 9024172 DOI: 10.1016/s0009-9236(97)90180-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Valsartan is an oral antagonist of angiotensin II that competes with angiotensin II for the AT1-receptor and is being developed as an antihypertensive agent. This study assessed the ability of 80 mg valsartan to inhibit the pressor effect of exogenous angiotensin II in healthy normotensive men, first after a single dose and then after multiple doses once daily for 7 days. METHODS This was a single-center, double-blind, placebo-controlled, randomized crossover study. Six healthy men underwent angiotensin II challenges to determine a suitable dose required to increase their systolic blood pressure by approximately 30 mm Hg. Each subject then received an 80 mg dose of valsartan or matching placebo. The inhibition of the angiotensin II pressor effect was determined by the systolic blood pressure response to repeated angiotensin II challenges at multiple time points. RESULTS Systolic blood pressure responses to angiotensin II challenges after single and multiple doses of valsartan were significantly lower than placebo, indicating that valsartan blocked the blood pressure response to angiotensin II. The maximum blocking effect was observed within 2 to 3 hours. Mean data suggested that differences in effect between valsartan and placebo were similar after both single and multiple doses and persisted up to 24 hours after administration. The angiotensin II blocking effect was maintained up to this time, despite low plasma valsartan levels and minimal accumulation after multiple doses. CONCLUSION Valsartan, 80 mg, is a potent angiotensin II antagonist with a rapid onset of action and persistent angiotensin II inhibition up to 24 hours. There is no attenuation of this effect after multiple doses.
Collapse
|
138
|
Hjelm R, Draper C, Spencer S. Anterior-inferior capsular length insufficiency in the painful shoulder. J Orthop Sports Phys Ther 1996; 23:216-22. [PMID: 8919401 DOI: 10.2519/jospt.1996.23.3.216] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Our clinic's initial attempts to document shoulder capsular laxity made us increasingly aware of the presence of subtle restricted passive shoulder movement in patients with a variety of shoulder diagnoses. The purpose of this study is to describe the evaluation, physical therapy treatment, pathomechanics, and implications of a continuum of anterior-inferior capsular length insufficiency and shoulder pain. One hundred fifty-six patients with the diagnoses of shoulder pain, impingement, rotator cuff tendinitis, and frozen shoulder were found to have capsular length insufficiency and were treated by mobilization techniques deemed as manual decompression. Eighty-three percent displayed good to excellent outcomes for decreasing pain, increasing range of motion, and meeting functional goals. Recent literature has supported the concept that capsular ligaments not only provide restraint, but are specifically oriented to guide and center the humeral head on the glenoid during shoulder movements. These patients presented with abnormal glenohumeral mechanics due to anterior capsular ligament length insufficiency. Glenohumeral ligament length insufficiency can be the primary cause of shoulder pain, ranging from frozen shoulder to impingement-like symptoms. Proper capsular ligament length can be restored with manual techniques. All patients with shoulder pain should have capsular ligament length assessment to ensure proper glenohumeral mechanics.
Collapse
|
139
|
Spencer S, Hancock S, Mariscal C, Wooten A, Wheeler R, Brown J, Fisher C, Von Roemeling R. 79 Phase I experience of the hypoxic cytotoxin tirapazamine using multiple dosing schedules during fractionated irradiation. Radiother Oncol 1996. [DOI: 10.1016/s0167-8140(96)80086-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
140
|
Spencer S, Jensen HJ. Elastic chain in a random potential: Simulation of the displacement correlation function and relaxation. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 52:12939-12945. [PMID: 9980465 DOI: 10.1103/physrevb.52.12939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|
141
|
Farrell J, Gill D, Doyle G, Walshe JJ, Barry-Kinsella C, Doyle M, Farrell J, Walshe J, Abernathy VE, Murnaghan DJ, Higgins J, Darling M, Halligan A, O’Brien E, Conroy R, Walshe JJ, Middleton D, Martin J, Douglas JF, Vella J, Burke P, Hickey D, Staunton C, Little D, Keeling F, O’Callaghan J, Bouchier-Hayes D, Carmody M, Walshe J, Donohoe J, Buckley A, O’Meara N, McMahon M, Cronin CJ, Jefferson JA, Maxwell AP, Doherty CC, Hughes AE, Nevin NC, Browne G, Keogh JAB, Jefferson JA, Wright GD, Hughes AE, Doherty CC, Nevin NC, Spencer S, Spencer R, Hickey D, Walshe JJ, Spencer S, Murphy D, Farrell J, Walshe JJ, Maxwell AP, Doherty CC, Fogarty DG, Hughes AE, Nevin NC, Vella J, Campbell E, Doyle G, Carmody M, Donohoe J, Thomas G, Kelly D, Crosbie O, Hegarty J, Crowley C, Watson A, Keogh B, Tormey V, Conlon P, Farrell J, Horgan J, Donohoe J, Walshe JJ, Stafford DB, Johnson J, O’Callaghan J, Walshe J, Murphy BG, Yong A, McNamee PT, Leavey S, O’Neill D, Jennings S, Doyle G, Donohoe J, Carmody M. Irish nephrological society. Ir J Med Sci 1995. [DOI: 10.1007/bf02967210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
142
|
Dudley DJ, Spencer S, Edwin S, Mitchell MD. Regulation of human decidual cell macrophage inflammatory protein-1 alpha (MIP-1 alpha) production by inflammatory cytokines. Am J Reprod Immunol 1995; 34:231-5. [PMID: 8579760 DOI: 10.1111/j.1600-0897.1995.tb00946.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
PROBLEM Inflammation of human gestational tissues is a key pathophysiologic event in the genesis of infection-associated preterm labor. Human gestational tissues produce several inflammatory cytokines after stimulation with bacterial products. These include interleukin-1 beta (IL-1 beta), tumor necrosis factor-alpha (TNF alpha), and IL-6. Another class of cytokines includes chemokines of the "C-C" subclassification such as macrophage inflammatory protein-1 alpha (MIP-1 alpha). The purpose of this study was to determine whether cultured human decidual cells produce MIP-1 alpha in response to other inflammatory cytokines. METHODS Various concentrations of IL-1 beta, TNF alpha, IL-6, and IL-4 were incubated with confluent monolayer cultures of decidual cells isolated from normal term placentae for 16 h at 37 degrees C, and MIP-1 alpha concentrations in culture supernatants were measured by ELISA. RESULTS We found that incubation of decidual cells with IL-1 beta, TNF alpha, and IL-4 resulted in significant concentration-dependent increases in MIP-1 alpha production. IL-6 had no effect on MIP-1 alpha production. CONCLUSIONS Our data are the first to show that human decidual cells in culture produce MIP-1 alpha in response to other inflammatory cytokines. We suggest that decidual cell production of MIP-1 alpha is an important early event in the pathophysiology of infection-associated preterm labor.
Collapse
|
143
|
Maddux BA, Sbraccia P, Kumakura S, Sasson S, Youngren J, Fisher A, Spencer S, Grupe A, Henzel W, Stewart TA. Membrane glycoprotein PC-1 and insulin resistance in non-insulin-dependent diabetes mellitus. Nature 1995; 373:448-51. [PMID: 7830796 DOI: 10.1038/373448a0] [Citation(s) in RCA: 232] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Most patients with non-insulin-dependent diabetes mellitus are resistant to both endogenous and exogenous insulin. Insulin resistance precedes the onset of this disease, suggesting that it may be an initial abnormality. Insulin-receptor kinase activity is impaired in muscle, fibroblasts and other tissues of many patients with non-insulin-dependent diabetes mellitus, but abnormalities in the insulin-receptor gene do not appear to be the cause of this decreased kinase activity. Skin fibroblasts from certain insulin-resistant patients contain an inhibitor of insulin-receptor tyrosine kinase. Here we show that this inhibitor is a membrane glycoprotein, termed PC-1 (refs 10, 11). We find that PC-1 activity is increased in fibroblasts from seven of nine patients with typical non-insulin-dependent diabetes mellitus. In addition, overexpression of PC-1 in transfected cultured cells reduces insulin-stimulated tyrosine kinase activity. These studies raise the possibility that PC-1 has a role in the insulin resistance of non-insulin-dependent diabetes mellitus.
Collapse
|
144
|
King D, Spencer S. Invasive electroencephalography in mesial temporal lobe epilepsy. J Clin Neurophysiol 1995; 12:32-45. [PMID: 7896908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Invasive EEG recording of spontaneous seizures and correlations of findings with histopathology have defined a characteristic set of electrographic findings in medial temporal lobe epilepsy. The presence of periodic spikes before seizure onset has a significant correlation with reduced CA1 cell counts. This phenomenon is followed, in spontaneous seizures, by 13-25 Hz discharge in medial temporal lobe structures. Temporal neocortical seizure onsets have significantly faster frequencies than hippocampal onsets; hippocampal ictal onset frequencies also vary more often than neocortical onsets. Although hippocampus or entorhinal cortex are involved to a variable degree, the periodic spikes are more consistently seen in hippocampus. Sixty percent of mesial temporal ictal onsets initially propagate to the ipsilateral temporal neocortex. In another 30%, the initial area of propagation is the contralateral hippocampus, to which propagation occurs before involvement of the ipsilateral or contralateral temporal neocortex. Time to propagation of the seizure to the contralateral hippocampus is lengthened in direct proportion to CA4 cell loss, suggesting a role for CA4 in this process. Long interhemispheric propagation times are associated with good surgical outcomes and with the presence of mesial temporal sclerosis. This article also discusses correlation with hippocampal slice physiology, and significance of these findings in understanding the pathophysiology of medial temporal lobe epilepsy.
Collapse
|
145
|
Meredith R, Salter M, Kim R, Spencer S, Weppelmann B, Rodu B, Smith J, Lee J. 2048 Sucralfate for radiation mucositis: Results of a double-blind randomized trial. Int J Radiat Oncol Biol Phys 1995. [DOI: 10.1016/0360-3016(95)97950-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
146
|
Cairns HS, Spencer S, Hilson AJ, Rudge CJ, Neild GH. 99mTc-DMSA imaging with tomography in renal transplant recipients with abnormal lower urinary tracts. Nephrol Dial Transplant 1994; 9:1157-61. [PMID: 7800217 DOI: 10.1093/ndt/9.8.1157] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
This study examined whether renal parenchymal imaging using 99mTc DMSA scintigraphy with tomography is a sensitive measure of renal scarring in renal transplant recipients with an abnormal lower urinary tract and whether such scars correlate with impairment of renal function. Three groups of patients were compared: group 1, patients with an abnormal lower urinary tract and deteriorating renal function (n = 9); group 2, abnormal lower urinary tract and stable renal function (n = 5); and group 3, normal lower urinary tract and deteriorating renal function (n = 8). Eight of the nine patients in group 1 had multiple scars visible on 99mTc DMSA scans and this correlated with histology when a renal biopsy was performed; the only patient without scars had a transplant glomerulopathy. The presence of scars was associated with either raised intravesical pressures or recurrent urinary tract infections (UTIs). Only one patient in each of groups 2 and 3 had visible scars and both these patients had a history of recurrent UTIs. Patients in group 3 with deteriorating renal function due to chronic rejection documented by biopsy did not have cortical scars visible with 99mTc DMSA tomography. 99mTc DMSA scanning with tomography is a useful investigation in the management of renal transplant patients with declining renal function; multiple scars may indicate abnormal lower urinary tract function and are not seen in chronic rejection.
Collapse
|
147
|
Allison RT, Spencer S. Nucleolar organiser regions in odontogenic cysts and ameloblastomas. Br J Biomed Sci 1993; 50:309-12. [PMID: 8130691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Silver nucleolar organiser region (AgNOR) counts were performed on apical periodontal cysts, dentigerous cysts, odontogenic keratocysts, ameloblastomas and basal cell carcinomas. Significant differences, but with excessive overlap, were shown between dentigerous cysts and apical periodontal cysts and between odontogenic keratocysts and apical cysts. The mean AgNOR counts for all odontogenic cysts ranged between 2.02 and 2.65, and for ameloblastomas were 2.24, indicating that the method has neither a diagnostic nor a prognostic value in these lesions. Control oral squamous cell carcinoma tissues had significantly higher AgNOR counts than any other lesion tested.
Collapse
|
148
|
Potter M, Spencer S, Soong SJ, Hatch K. The influence of staging laparotomy for cervical cancer on patterns of recurrence and survival. Int J Gynecol Cancer 1993; 3:169-174. [PMID: 11578339 DOI: 10.1046/j.1525-1438.1993.03030169.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A matched paired study of surgically staged and non-surgically staged patients with stage II and III cervical carcinoma from October 1974 through August 1987 was retrospectively performed. Eight of 55 (13.8%) had para-aortic lymph node involvement. After tailored extended field radiation 2/8 (25%) remain alive without evidence of disease. Patient survival although slightly in favor of the unstaged group was similar. Patterns of recurrence were similar amongst treatment groups. Para-aortic nodal recurrence, despite tailored radiation therapy, was identical (5.4%) in the staged and unstaged groups. Only one patient (not surgically staged) had an isolated para-aortic recurrence. With the morbidity of an operative procedure and similar survival rates and para-aortic nodal recurrence rates, the value of staging laparotomy in improved patient survival is questioned. Pelvic failure and other distant metastases continue to be the major sites of recurrences.
Collapse
|
149
|
Spencer S. Treating mentally ill people in the community. BMJ (CLINICAL RESEARCH ED.) 1993; 306:458. [PMID: 8461746 PMCID: PMC1676502 DOI: 10.1136/bmj.306.6875.458-b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
|
150
|
Horuk R, Yansura DG, Reilly D, Spencer S, Bourell J, Henzel W, Rice G, Unemori E. Purification, receptor binding analysis, and biological characterization of human melanoma growth stimulating activity (MGSA). Evidence for a novel MGSA receptor. J Biol Chem 1993; 268:541-6. [PMID: 8380167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Human melanoma growth stimulating activity (MGSA) is a mitogenic factor first identified in the conditioned media of human melanoma cells. Structurally, MGSA belongs to a superfamily of proteins that includes interleukin-8 (IL-8) and platelet factor 4. These proteins are involved in inflammatory processes, and an understanding of their mechanism of action should provide insight into their pathophysiology. In this study, we report the high level expression of recombinant human MGSA in Escherichia coli. The structure was confirmed by mass spectrometry and NH2-terminal amino acid sequencing. Receptor binding studies were carried out in a human melanoma cell line, Hs294T, and in U937 cells. Direct binding experiments with 125I-MGSA in Hs294T cells have allowed us to identify a novel MGSA receptor in these cells, with a KD of 3.9-4.25 nM and approximately 52,960-67,758 binding sites/cell. These MGSA-binding sites were specific and could not be displaced by unlabeled IL-8. The MGSA receptor in these cells is biologically active, and the addition of ligand induces cellular proliferation in a dose-dependent manner. In U937 cells, unlabeled IL-8 and MGSA were able to completely displace radiolabeled IL-8. Scatchard analysis of the displacement binding data was consistent with binding to a single class of binding sites, and the calculated KD values were 2.4 +/- 0.6 nM for IL-8 and 3.2 +/- 0.80 nM for MGSA. Treatment of U937 cells with IL-8 or MGSA produced a rapid increase in Ca2+ flux; however, subsequent incubation with either ligand failed to produce any further Ca2+ flux. The IL-8 receptor in U937 cells was covalently labeled with 125I-IL-8 to reveal a protein with a molecular mass of 69 kDa.
Collapse
|