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Brown BL, Lapinski R, Berkowitz GS, Holzman I. Fractured clavicle in the neonate: a retrospective three-year review. Am J Perinatol 1994; 11:331-3. [PMID: 7993510 DOI: 10.1055/s-2007-994546] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A hospital-based case-controlled study was undertaken to determine maternal and neonatal characteristics associated with fractured clavicle. A total of 11,604 consecutive vaginal deliveries of liveborn infants in vertex presentation at the Mount Sinai Hospital from 1988 to 1990 were reviewed. Maternal and neonatal characteristics were compared for the neonates with and without a diagnosis of a fractured clavicle. Compared to controls, mothers of neonates with a fractured clavicle were more likely to be nulliparas or primiparas, to have had an operative vaginal delivery, and to have been delivered by an attending as opposed to a resident physician. The fractured clavicle group also had a longer gestational age, greater birthweight, and higher frequency of macrosomic infants. After controlling for maternal parity, type of delivery and infant birthweight, experience of the delivering physician, and gestational age at delivery were not significantly different. Fracture of the clavicle in the neonate is related to maternal parity, mode of delivery, and infant birthweight but not to the level of experience of the delivering physician.
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Budowle B, Monson KL, Giusti AM, Brown BL. Evaluation of Hinf I-generated VNTR profile frequencies determined using various ethnic databases. J Forensic Sci 1994; 39:988-1008. [PMID: 7914910] [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]
Abstract
Concerns have been raised about hypothetical problems arising from the use of statistics for determining the likelihood of occurrence of DNA profiles for forensic purposes. A major contention is that reference databases based on subgroups of a major population category rather than on general (or major) population groups, might yield large differences in the estimated likelihood of occurrence of DNA profiles. This hypothetical issue is based on the assertion by some people that the differences among subgroups within a race would be greater than between races (at least for forensic purposes). To evaluate the effects of the above concern the likelihood of occurrence of 615 Hinf I-generated target DNA profiles was estimated using fixed bin frequencies from various ethnic databases and the multiplication rule. Based on the data in this study, differences in allele frequencies at a particular locus do not have substantial effects on VNTR profile frequency estimates when subgroup reference databases from within a major population group are compared. In contrast, the greatest variation in statistical estimates occurs across-major population groups. Therefore, the assertion, by some critics that the differences among subgroups within a race would be greater than between races (at least for forensic purposes), is unfounded. The data in the study support that comparisons across major population groups provide valid estimates of DNA profile frequencies without forensically significant consequences. The data do not support the need for alternate procedures, such as the ceiling principle approach, for deriving statistical estimates of DNA profile frequencies.
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Cabeza de Vaca S, Brown BL, Hemmes NS. Internal clock and memory processes in animal timing. JOURNAL OF EXPERIMENTAL PSYCHOLOGY. ANIMAL BEHAVIOR PROCESSES 1994. [PMID: 8189187 DOI: 10.1037//0097-7403.20.2.184] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Temporal control of behavior was investigated within the framework of an internal clock model. Pigeons were exposed to signaled fixed-interval 30-s trials mixed with extended unreinforced (baseline) trials. On unreinforced break trials, the signal was interrupted for a period of time after trial onset. In Experiment 1, comparisons between the peak time obtained on baseline and on break trials produced peak time shifts that were longer than those expected if the clock had stopped during the break but shorter than if the clock had reset. In Experiment 2, systematic manipulations of duration and location of breaks produced peak time shifts that were nonlinear functions of break duration and that varied linearly with break location. The obtained peak times were more consistent with a continuous memory decay model than with the stop-retain or the reset hypotheses.
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Cabeza de Vaca S, Brown BL, Hemmes NS. Internal clock and memory processes in animal timing. JOURNAL OF EXPERIMENTAL PSYCHOLOGY. ANIMAL BEHAVIOR PROCESSES 1994; 20:184-98. [PMID: 8189187 DOI: 10.1037/0097-7403.20.2.184] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Temporal control of behavior was investigated within the framework of an internal clock model. Pigeons were exposed to signaled fixed-interval 30-s trials mixed with extended unreinforced (baseline) trials. On unreinforced break trials, the signal was interrupted for a period of time after trial onset. In Experiment 1, comparisons between the peak time obtained on baseline and on break trials produced peak time shifts that were longer than those expected if the clock had stopped during the break but shorter than if the clock had reset. In Experiment 2, systematic manipulations of duration and location of breaks produced peak time shifts that were nonlinear functions of break duration and that varied linearly with break location. The obtained peak times were more consistent with a continuous memory decay model than with the stop-retain or the reset hypotheses.
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Budowle B, Monson KL, Giusti AM, Brown BL. The assessment of frequency estimates of Hae III-generated VNTR profiles in various reference databases. J Forensic Sci 1994; 39:319-52. [PMID: 7910844] [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]
Abstract
The likelihood of occurrence of 1964 Hae III-generated target DNA profiles was estimated using fixed bin frequencies from various regional and ethnic databases and the multiplication rule. The databases generally were from the following major categories: Black, Caucasian, Hispanic, Oriental, and American Indian. It was found that subdivision, either by ethnic group or by U.S. geographic region, within a major population group did not substantially affect forensic estimates of the likelihood of occurrence of a DNA profile. As expected, the greatest variation in estimates for within-group estimates was among American Indian databases. Because the greatest variation in statistical estimates occurs across-major population groups, in most cases, there will be no unfair bias applying general population database estimates. Therefore, based on empirical data, there is no demonstrable need for using alternate approaches, such as the ceiling approach, to derive statistical estimates. The current practice of using general population databases and the multiplication rule provides valid estimates of the likelihood of occurrence of a DNA profile.
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Virdee K, Brown BL, Dobson PR. Stimulation of arachidonic-acid release from Swiss 3T3 cells by recombinant basic fibroblast growth factor: independence from phosphoinositide turnover. BIOCHIMICA ET BIOPHYSICA ACTA 1994; 1220:171-80. [PMID: 8312361 DOI: 10.1016/0167-4889(94)90132-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In this study we have attempted to characterize the mechanism of recombinant bovine basic fibroblast growth factor (rbFGF)-induced release of arachidonic acid from prelabelled Swiss 3T3 fibroblasts. Recombinant bFGF caused the release of [3H]arachidonic acid from metabolically labelled cells in a dose- and time-dependent manner. This effect was maximal with 10 ng rbFGF/ml and became significant after a 30-min incubation. Although rbFGF was able to cause a modest increase in total inositol phosphate accumulation, an examination of the time-course of the latter effect revealed that enhanced [3H]arachidonic-acid release could not have been derived from phosphoinositide metabolism. Evidence suggesting that rbFGF-induced release of [3H]arachidonic acid was being mediated via a PLA2 pathway was obtained by pharmacological antagonism using mepacrine, a putative PLA2 inhibitor. Moreover, treatment of cells with neomycin failed to attenuate rbFGF-mediated release of [3H]arachidonic acid. Chelation of extracellular calcium by EGTA was found to abrogate rbFGF-induced liberation of [3H]arachidonic add. Down-regulation of protein kinase C (PKC) by prolonged treatment of cells with the phorbol ester, PMA, was observed to have no effect on the action of rbFGF on [3H]arachidonic add release from Swiss 3T3 fibroblasts. While rbFGF was found to cause the indomethacin-sensitive production of prostaglandin E2 (PGE2) in a dose-dependent manner, this effect was independent of rbFGF-induced reinitiation of DNA synthesis. Clearly, the effect of rbFGF on cellular DNA synthesis was being mediated independently of PGE2 biosynthesis. We discuss the potential importance of the PLA2-signalling pathway in the mechanism of action of fibroblast growth factors.
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el Kareh A, Beddoe AM, Brown BL. Advanced abdominal pregnancy complicated by bilateral ureteral obstruction. A case report. THE JOURNAL OF REPRODUCTIVE MEDICINE 1993; 38:900-2. [PMID: 7506310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
A case of term abdominal pregnancy is reported. The patient was followed throughout pregnancy, but the diagnosis was made only at the time of laparotomy for elective cesarean section. The report exemplifies the ease with which the diagnosis of abdominal pregnancy can be overlooked and stresses the importance of considering this diagnosis in cases of high maternal serum alpha-fetoprotein. The management of the placenta is also discussed. In this case the retained placenta was managed successfully without intervention despite the unusual complication of bilateral ureteral obstruction. Additionally, the biochemical activity of the placenta was assessed by following the progressive decline of serum human chorionic gonadotropin over time.
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Brown BL, Williamson SE. A system for documentation of pharmacist interventions with incorporation into performance and quality improvement plans. Hosp Pharm 1993; 28:1083-4, 1086-8. [PMID: 10130385] [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
Budgetary constraints have compelled hospital administrators to take a more discerning look at the role of the pharmacist within the healthcare team. In 1991, financial difficulties and hospital-wide cutbacks at Northern Michigan Hospital resulted in the loss of pharmacy personnel. Consequently, the department has increasingly found it necessary to document the clinical activities of the pharmacists and their potential effect on patient care. To document therapeutic interventions, two forms specific to this activity were developed. These forms allowed evaluation of both the quantity and quality of interventions. The authors realize it is essential for pharmacists to not only maintain, but to continually update their knowledge base to be prepared for the future. A staff development program was developed to help meet the educational needs of the pharmacists. This article describes how therapeutic interventions were integrated into the quality improvement and performance plans to help motivate staff to continually improve their pharmacy practice skills at this institution.
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Lockwood CJ, Costigan K, Ghidini A, Wein R, Chien D, Brown BL, Alvarez M, Cetrulo CL. Double-blind; placebo-controlled trial of piperacillin prophylaxis in preterm membrane rupture. Am J Obstet Gynecol 1993; 169:970-6. [PMID: 8238159 DOI: 10.1016/0002-9378(93)90037-j] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
OBJECTIVE We attempted to test whether antibiotic therapy prolongs pregnancy in preterm premature rupture of membranes, because preterm premature rupture of membranes is frequently associated with chorionic-decidual infection. STUDY DESIGN Women with preterm premature rupture of membranes and a singleton gestation at 24 to 34 completed weeks were randomized to receive either piperacillin 3 gm or placebo intravenously every 6 hours for 72 hours and were managed conservatively until spontaneous delivery, chorioamnionitis, or fetal distress. RESULTS Between January 1987 and January 1992, a total of 75 patients were randomized to receive piperacillin (n = 38) or placebo (n = 37). There were no differences between the piperacillin group and the placebo group in mean gestational age at randomization (30.2 +/- 3 vs 30.3 +/- 2.9 weeks). However, a greater number of patients had pregnancy prolonged beyond 7 days (42.1% vs 10.8% p = 0.005) and the mean latency period was significantly prolonged (11.4 +/- 18.8 vs 6.1 +/- 13.6 days, p = 0.001) in the piperacillin group compared with the control groups. CONCLUSIONS Use of intravenous piperacillin for 72 hours in preterm premature rupture of membranes significantly prolongs the latency period between membrane rupture and delivery.
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Brown BL, Brown JW. OSHA regulations demand strict documentation, compliance. PROVIDER (WASHINGTON, D.C.) 1993; 19:37-8. [PMID: 10123202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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Brown JW, Brown BL. OSHA training must reflect employee education, literacy levels. PROVIDER (WASHINGTON, D.C.) 1992; 18:31-2. [PMID: 10119641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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Rahman S, Bunning RA, Dobson PR, Evans DB, Chapman K, Jones TH, Brown BL, Russell RG. Bradykinin stimulates the production of prostaglandin E2 and interleukin-6 in human osteoblast-like cells. BIOCHIMICA ET BIOPHYSICA ACTA 1992; 1135:97-102. [PMID: 1591276 DOI: 10.1016/0167-4889(92)90172-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The effect of bradykinin (BK) on proteinase activity, prostaglandin synthesis, and the production of interleukin-6 (IL-6) was investigated in cultures of human osteoblast-like cells. Bradykinin had no effect on stromelysin activity and plasminogen activator activity produced by human osteoblast-like cells. However, BK stimulated the production of prostaglandin E2, an effect that was markedly enhanced by pre-incubation with recombinant interleukin-1 alpha (rhIL-1 alpha), but was apparently unaffected by BK receptor antagonists types 1 and 2. Bradykinin stimulated the intracellular accumulation of total inositol phosphates suggesting that its effects were mediated by stimulation of phosphoinositide metabolism. Bradykinin within the dose range of 10(-11)-10(-5) M also significantly stimulated the production of IL-6. Bradykinin may, therefore, mediate a variety of responses in bone under both physiological and pathological conditions.
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Hassin-Herman AD, Hemmes NS, Brown BL. Behavioral contrast: Pavlovian effects and anticipatory contrast. J Exp Anal Behav 1992; 57:159-75. [PMID: 1573371 PMCID: PMC1323119 DOI: 10.1901/jeab.1992.57-159] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Two sources of behavioral contrast have been identified previously: Pavlovian stimulus-reinforcer relations and component sequence effects (anticipatory contrast). This study sought to isolate these sources of control procedurally in a four-ply multiple schedule composed of two fixed two-component sequences. Different cues were associated with the first component of each sequence, and contrast effects were studied in these target components. In Experiment 1, differential cuing of Component 2 between sequences and availability of reinforcement during target components were varied across three groups of pigeons; the stimulus-reinforcer relation between target-component cues and schedule of reinforcement in Component 2 was varied within subjects. Control by the Pavlovian relation was demonstrated under all conditions, and anticipatory contrast was not observed. In Experiment 2, target-component duration was systematically varied in the three groups of Experiment 1. Control by the Pavlovian relation was reliably obtained only when target-component behavior was unreinforced, and diminished with increases in component duration. Anticipatory contrast emerged in the two groups for which target-component reinforcement was available. These and other data indicate that Pavlovian effects in multiple schedules may be obscured when the requisite conditions for anticipatory contrast are present.
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Schuller DE, Goodman JH, Brown BL, Frank JE, Ervin-Miller KJ. Maxillary removal and reinsertion for improved access to anterior cranial base tumors. Laryngoscope 1992; 102:203-12. [PMID: 1738294 DOI: 10.1288/00005537-199202000-00017] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Portions or all of the maxillae are oftentimes removed solely to provide access to certain cranial base tumors rather than because they are involved directly with disease. The purpose of this report is to describe an approach that involves removal of one or both maxillae to improve tumor exposure with subsequent reinsertion as free bone grafts which are stabilized with titanium craniofacial fixation plates. The titanium permits postoperative imaging studies and radiotherapy. Eleven patients ranging from 10 to 69 years of age have undergone 12 operations using this technique for resection of 4 benign and 8 malignant tumors at The Ohio State University. Seven of the 8 patients with malignancies underwent postoperative radiation therapy. There have been no permanent complications and no evidence of bone resorption in this group after follow-up of up to 15 months.
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Rahman S, Dobson PR, Bunning RA, Russell RG, Brown BL. The regulation of connective tissue metabolism by vasoactive intestinal polypeptide. REGULATORY PEPTIDES 1992; 37:111-21. [PMID: 1311458 DOI: 10.1016/0167-0115(92)90660-m] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Immunohistochemical studies have confirmed the innervation of bone with neuropeptidergic neurons containing vasoactive intestinal polypeptide (VIP), substance P (SP) and calcitonin gene-related peptide (CGRP). In this study, we report effects of VIP on connective tissue cell metabolism. VIP stimulated PGE2 production in human articular chondrocytes, human osteoblast-like cells and human synovial cells, however, stromelysin production was unaffected. VIP also stimulated cAMP production in human osteoblast-like cells, but not in human articular chondrocytes or synovial cells. These findings are suggestive of a role of VIP in connective tissue cell metabolism which may contribute to the inflammatory processes of arthritis.
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Jones TH, Brown BL, Cullen DR, Dobson PR. Effect of the GABAA agonist muscimol on prolactin secretion from human prolactin-secreting adenomas and GH3 rat pituitary tumour cells. HORMONE RESEARCH 1992; 37:113-8. [PMID: 1335954 DOI: 10.1159/000182293] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The effect of muscimol, a specific potent GABAA receptor agonist, on prolactin release from human prolactin-secreting tissue was investigated using a perifusion system. Perifusion studies on normal rat anterior pituitary tissue, which has identical GABA receptors to those found in normal human pituitary glands, show that muscimol has a specific biphasic effect on prolactin release. This is characterized by an initial transient stimulation (222.3 +/- 21.6% of basal) lasting for 5-10 min followed by a more prolonged inhibitory phase (63.9 +/- 3.1% inhibition of basal). Five human prolactin-secreting adenomas were studied, and in none of the tumours could a biphasic response be demonstrated. One of the prolactin-secreting adenomas had a blunted inhibitory response, but the other 4 showed no inhibitory effect of muscimol on prolactin release. Muscimol had no significant effect on basal or thyrotropin-releasing-hormone (TRH)-stimulated prolactin secretion from GH3 rat pituitary tumour cells. These studies suggest that the GABAergic effect on prolactin secretion is absent or altered in both rat and human prolactin-secreting tumour cells.
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Hitchin BW, Dobson PR, Brown BL, Hardcastle J, Hardcastle PT, Taylor CJ. Measurement of intracellular mediators in enterocytes isolated from jejunal biopsy specimens of control and cystic fibrosis patients. Gut 1991; 32:893-9. [PMID: 1653176 PMCID: PMC1378958 DOI: 10.1136/gut.32.8.893] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A method that maximises the yield of viable enterocytes has been developed for the isolation of enterocytes from human jejunal biopsy specimens. These enterocytes have been used to study the values of intracellular free calcium and the rises in adenosine 3'5'-cyclic monophosphate (cAMP) induced by secretagogues in normal and cystic fibrosis cells. Basal intracellular free calcium of cystic fibrosis enterocytes, measured fluorimetrically with fura-2, was within the range of the basal intracellular free calcium of non-cystic fibrosis enterocytes (cystic fibrosis 263 nmol/l; non-cystic fibrosis 287 nmol/l). Changes in intracellular free calcium were observed after exposure to ionomycin: a 100 nmol/l solution induced a 2.5 fold increase in intracellular free calcium in the cystic fibrosis enterocytes and a 2.2 fold increase in the intracellular free calcium concentration of the non-cystic fibrosis enterocytes. Basal cAMP values were not significantly different between cystic fibrosis and non-cystic fibrosis enterocytes (cystic fibrosis 575 fmol/100,000 cells; non-cystic fibrosis 716 fmol/100,000 cells, p greater than 0.05) and the enterocyte cAMP value increased in response to stimulation with prostaglandin E2 (7 mumol/l) (cystic fibrosis 2.2 fold increase over basal, p less than 0.05; non-cystic fibrosis 1.9 fold stimulation over basal, p less than 0.05) and vasoactive intestinal polypeptide (100 nmol/l) (cystic fibrosis 7.1 fold increase over basal, p less than 0.05; non-cystic fibrosis 5.8 fold increase over basal, p less than 0.05). There was no significant difference in the magnitude of the response between cystic fibrosis and non-cystic fibrosis enterocytes (p greater than 0.05). These results indicate that the cystic fibrosis defect in the small intestine, as in other affected epithelia, seems to be distal to the production of second messengers. The small intestine is therefore an appropriate model in which to study the biochemical defect in cystic fibrosis.
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Short AD, Brown BL, Dobson PR. The effect of retinoic acid on parathyroid hormone- and parathyroid hormone-related peptide-induced intracellular calcium in a rat osteosarcoma cell line, UMR106. J Endocrinol 1991; 129:75-81. [PMID: 2030332 DOI: 10.1677/joe.0.1290075] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We have examined the effects of parathyroid hormone (PTH) and PTH-related peptide (PTH-rP) on intracellular calcium (Ca2+i) in a rat osteogenic sarcoma cell line, UMR106. Synthetic bovine (b)PTH(1-34) caused a small inconsistent rise in Ca2+i in UMR106 cells, whilst cells pretreated with retinoic acid (RA, 1 mumol/l) for 18 h exhibited reproducible, significant and dose-dependent increases in Ca2+i levels in response to bPTH. The effect of RA on PTH-induced changes in Ca2+i were dependent upon both dose and time. Purified human (h)PTH-rP(1-34) increased Ca2+i in the absence of RA in the same cells. However, RA increased the magnitude of PTH-rP-stimulated changes in Ca2+i without affecting the concentration required for a maximal response. RA also prolonged the delay before the Ca2+i response was observed. Maximal responses to PTH-rP were greater in magnitude than those to PTH. These changes appeared not to be due to cyclic AMP (cAMP), since neither dibutyryl cAMP (1 mmol/l) nor forskolin (15 mumol/l) affected Ca2+i. PTH- and PTH-rP-mediated Ca2+i transients were not completely abolished by the absence of extracellular calcium, and both peptides increased basal levels of inositol trisphosphate. PTH and PTH-rP were subject to mutual desensitization, but were not desensitized by prostaglandin E2. PTH(7-34) antagonized PTH- but not PTH-rP-mediated Ca2+i transients. We conclude that there may be some important differences in the mechanism of action of PTH and PTH-rP.
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Stirland JA, Brown BL, Dobson PR. Kallidin stimulates prolactin secretion from individual rat anterior pituitary cells. J Endocrinol 1991; 128:315-20. [PMID: 2005421 DOI: 10.1677/joe.0.1280315] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Kinins are localized within the adenohypophysis where they have been shown to stimulate the release of pituitary hormones. In the present study we have investigated the effect of [Lys]-bradykinin (kallidin) on prolactin secretion at the single cell level from cultured male rat anterior pituitary cells. This was assessed by use of a reverse haemolytic plaque assay which permits quantitative evaluation of the proportion of all pituitary cells which are secreting prolactin, and the amount of prolactin secreted per lactotroph (plaque area). The rate of plaque development was used as an index of the rate of hormone secretion in time-course studies. Kallidin induced a dose-dependent increase in both the percentage of plaque-forming cells and the median plaque area during the first 2 and 3 h of incubation respectively. The threshold concentration of kallidin was 10 nmol/l. After 4 h of kallidin stimulation there was no difference between treated and control monolayers with respect to median plaque area and the total secretion index. Although recruitment of additional cells into the secretory pool cannot be excluded, this seems unlikely since at 3 and 4 h little or no difference was observed in the number of plaque-forming cells. The data suggest that initially kallidin accelerated the rate of prolactin secretion primarily by inducing an increase in the number of cells secreting prolactin, and subsequently by increasing the amount of hormone secreted per lactotroph. The results presented here are consistent with the proposed role of the kallikrein-kinin system in the paracrine or autocrine control of prolactin release from the pituitary gland.
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Atra E, Metz CA, Brown BL, Teoh K. Flurbiprofen versus diclofenac for the treatment of osteoarthritis of the knee. DICP : THE ANNALS OF PHARMACOTHERAPY 1990; 24:920-3. [PMID: 2244403 DOI: 10.1177/106002809002401001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Seventy-four patients were enrolled in this double-blind, randomized single-center study to evaluate the therapeutic effectiveness of 50 mg tid regimens of flurbiprofen or diclofenac sodium in patients with osteoarthritis of the knee. By chance, the flurbiprofen patients had a significantly more advanced disease status at baseline than their diclofenac-treated counterparts. However, at subsequent follow-up evaluations, both treatment groups experienced a significant reduction in disease severity regardless of the baseline differences. No serious safety problems were associated with either investigational therapy. The frequency of reported medical events were distributed equally between the flurbiprofen and diclofenac groups. Although the imbalance in disease severity between treatment groups made a rigorous statistical interpretation of the results very difficult, the data from this clinical trial tend to support the equiefficacy of 50 mg tid regimens of flurbiprofen versus diclofenac for treating osteoarthritis of the knee.
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Brown JW, Blackwell H, Brown BL. Infection control reduces work-related exposure to AIDS. PROVIDER (WASHINGTON, D.C.) 1990; 16:61-3. [PMID: 10107242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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Dobson PR, Skjodt H, Plested CP, Short AD, Virdee K, Russell RG, Brown BL. Interleukin-1 stimulates diglyceride accumulation in the absence of protein kinase C activation. REGULATORY PEPTIDES 1990; 29:109-16. [PMID: 2171043 DOI: 10.1016/0167-0115(90)90074-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Despite advances in the knowledge of the intracellular signalling in response to extracellular messengers, the mechanism of action of interleukin-1 (IL-1) has remained an enigma. In the present study, we have employed human dermal fibroblasts (Detroit 532 cells) to investigate IL-1 beta-induced changes in intracellular signals. Both recombinant human IL-1 beta and a native preparation purified from human placental tissue were employed. Cyclic AMP levels in cell monolayers were unaltered by IL-1 beta. Also, IL-1 beta did not influence significantly the levels of phosphatidylinositol, phosphatidylinositol 4-monophosphate, and phosphatidylinositol 4,5-bisphosphate in the membrane, nor the water-soluble inositol phosphates, inositol monophosphate, inositol bisphosphate and inositol trisphosphate, in cells prelabelled with myo-[3H]inositol. In addition, intracellular calcium as measured by Quin2 was unaffected by interleukin-1. However, in cells labelled with [3H]glycerol or [3H]arachidonic acid, IL-1 beta caused an immediate rise in diglyceride (DG) accumulation. As the effects of IL-1 beta have been reported to be mimicked by tumour-promoting phorbol esters, this rise in DG suggested the involvement of protein kinase C (PKC). However, repeated experiments failed to reveal any acute effect of IL-1 beta on the activity of this enzyme. Furthermore, IL-1 beta did not cause the translocation of PKC between the membrane and the cytosol as has been found in response to other extracellular signals. Rather, IL-1 beta appeared to increase the synthesis of PKC in both membrane and cytosol preparations, an effect which could be prevented by coincubation with cycloheximide. These findings suggest that the diglyceride formed in response to IL-1 beta does not activate protein kinase C.
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Jones TH, Brown BL, Dobson PR. Kallidin-induced stimulation of inositol phosphate production and prolactin release in rat anterior pituitary cells. ACTA ENDOCRINOLOGICA 1990; 123:37-42. [PMID: 2167600 DOI: 10.1530/acta.0.1230037] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The effect of the kinin, kallidin (lysyl-bradykinin) on phosphoinositide metabolism and prolactin secretion was examined in male rat anterior pituitary cells in primary culture. Kallidin was found to stimulate both total inositol phosphate production and prolactin release. The stimulation of inositol phosphate was biphasic in nature, similar to that previously reported for bradykinin, although kallidin was approximately 10-fold more potent. Kallidin also stimulated prolactin secretion provoking a maximal stimulation of 193.0 +/- 11.1 (sem)% at 1 mumol/l. These findings suggest that kallidin-induced prolactin secretion may be mediated intracellularly by activation of phosphoinositide metabolism. The B2 receptor antagonists had no significant inhibitory effects on kallidin-stimulated phosphoinositide metabolism or prolactin release. The B1 agonist des-Arg9-bradykinin has previously been shown to have no effect on either parameter. As the effects of kinins on anterior pituitary cells do not appear to be mediated by either of the known kinin receptors, they may, therefore, act via a hitherto unrecognised kinin receptor.
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Dobson PR, Brown BL, Michelangeli VP, Short AD, Moseley JM, Russell RG, Martin TJ. Interactive regulation of signalling pathways in bone cells: possible modulation of PGE2-stimulated adenylyl cyclase activity by protein kinase C. BIOCHIMICA ET BIOPHYSICA ACTA 1990; 1052:323-6. [PMID: 2334740 DOI: 10.1016/0167-4889(90)90228-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We have reported previously that tumour-promoting phorbol esters modulate both basal and vasoactive intestinal polypeptide (VIP)-stimulated adenylyl cyclase activity in GH3 (an established pituitary cell line). Here, we probe the receptor and cell specificity of this response. Experiments were performed in the presence of isobutylmethylxanthine. Unlike the response in GH3 cells, the tumour-promoting phorbol ester (tetradecanoyl phorbol acetate (TPA] did not affect either basal adenylyl cyclase activity nor VIP-stimulated activity in the rat osteosarcoma subclones UMR 106-01 and UMR 106-06. In addition, the cyclase responses to parathyroid hormone (PTH), and, in the case of UMR 106-06, to calcitonin were unaffected by tumour-promoting phorbol ester. However, prostaglandin E2-stimulated cyclase activity in both of these subclones was attenuated in a dose-dependent manner.
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