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1.
BMC Pregnancy Childbirth ; 20(1): 383, 2020 Jul 01.
Article in English | MEDLINE | ID: mdl-32611330

ABSTRACT

BACKGROUND: Lack of a unified and comparable classification system to unravel the underlying causes of stillbirth hampers the development and implementation of targeted interventions to reduce the unacceptably high stillbirth rates (SBR) in sub-Saharan Africa. Our aim was to track the SBR and the predominant maternal and fetal causes of stillbirths using the WHO ICD-PM Classification system. METHODS: This was a retrospective observational study in a major referral centre in northeast Nigeria between 2010 and 2018. Specialist Obstetricians and Gynaecologists assigned causes of stillbirths after an extensive audit of available stillbirths' records. Cause of death was assigned via consensus using the ICD-PM classification system. RESULTS: There were 21,462 births between 1 January 2010 and 31 December 2018 in our study setting; of these, 1177 culminated in stillbirths with a total hospital SBR of 55 per 1000 births (95% CI: 52, 58). There were two peaks of stillbirths in 2012 [62 per 1000 births (95% CI: 53, 71)], and 2015 [65 per 1000 births (95% CI, 55, 76)]. Antepartum and intrapartum stillbirths were almost equally prevalent (48% vs 52%). Maternal medical and surgical conditions (M4) were the commonest (69.3%) cause of antepartum stillbirths while complications of placenta, cord and membranes (M3) accounted for the majority (45.8%) of intrapartum stillbirths and the trends were similar between 2010 and 2018. Antepartum and intrapartum fetal causes of stillbirths were mainly due to prematurity which is a disorder of fetal growth (A5 and I6). CONCLUSIONS: Most causes of stillbirths in our setting are due to preventable causes and the trends have remained unabated between 2010 and 2018. Progress toward global SBR targets are off-track, requiring more interventions to halt and reduce the high SBR.


Subject(s)
Stillbirth/epidemiology , Birth Weight , Cause of Death , Female , Gestational Age , Humans , International Classification of Diseases , Nigeria/epidemiology , Pregnancy , Referral and Consultation , Retrospective Studies , World Health Organization
2.
Br J Surg ; 106(6): 692-699, 2019 05.
Article in English | MEDLINE | ID: mdl-30919948

ABSTRACT

BACKGROUND: Transverse abdominis plane (TAP) block is considered an effective alternative to neuraxial analgesia for abdominal surgery. However, limited evidence supports its use over traditional analgesic modalities in colorectal surgery. This study compared the analgesic efficacy of liposomal bupivacaine TAP block with intrathecal (IT) opioid administration in a multicentre RCT. METHODS: Patients undergoing elective small bowel or colorectal resection were randomized to receive TAP block or a single injection of IT analgesia with hydromorphone. Patients were assessed at 4, 8, 16, 24 and 48 h after surgery. Primary outcomes were mean pain scores and morphine milligram equivalents (MMEs) administered within 48 h after surgery. Secondary outcomes included duration of hospital stay, incidence of postoperative ileus and use of intravenous patient-controlled analgesia. RESULTS: In total, 209 patients were recruited and 200 completed the trial (TAP 102, IT 98). The TAP group had a 1·6-point greater mean pain score than the IT group at 4 h after surgery, and this difference lasted for 16 h after operation. The TAP group received more MMEs within the first 24 h after surgery than the IT group (median difference in MMEs 10·0, 95 per cent c.i. 3·0 to 20·5). There were no differences in MME use at 24 and 48 h, or with respect to secondary outcomes. CONCLUSION: IT opioid administration provided better immediate postoperative pain control than TAP block. Both modalities resulted in low pain scores in patients undergoing elective colorectal surgery and should be considered in multimodal postoperative analgesic plans. Registration number: NCT02356198 ( http://www.clinicaltrials.gov).


Subject(s)
Abdominal Muscles/innervation , Analgesics, Opioid/administration & dosage , Anesthetics, Local/administration & dosage , Bupivacaine/administration & dosage , Hydromorphone/administration & dosage , Nerve Block/methods , Pain, Postoperative/prevention & control , Aged , Analgesia, Patient-Controlled , Analgesics, Opioid/therapeutic use , Anesthetics, Local/therapeutic use , Bupivacaine/therapeutic use , Colorectal Surgery , Elective Surgical Procedures , Female , Humans , Hydromorphone/therapeutic use , Injections, Spinal , Liposomes , Male , Middle Aged , Morphine/therapeutic use , Pain Measurement , Pain, Postoperative/diagnosis , Pain, Postoperative/drug therapy , Prospective Studies , Treatment Outcome
3.
Br J Anaesth ; 116(2): 163-76, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26787787

ABSTRACT

BACKGROUND: This systematic review evaluated the evidence comparing patient-important outcomes in spinal or epidural vs general anaesthesia for total hip and total knee arthroplasty. METHODS: MEDLINE, Ovid EMBASE, EBSCO CINAHL, Thomson Reuters Web of Science, and the Cochrane Central Register of Controlled Trials from inception until March 2015 were searched. Eligible randomized controlled trials or prospective comparative studies investigating mortality, major morbidity, and patient-experience outcomes directly comparing neuraxial (spinal or epidural) with general anaesthesia for total hip arthroplasty, total knee arthroplasty, or both were included. Independent reviewers working in duplicate extracted study characteristics, validity, and outcomes data. Meta-analysis was conducted using the random-effects model. RESULTS: We included 29 studies involving 10 488 patients. Compared with general anaesthesia, neuraxial anaesthesia significantly reduced length of stay (weighted mean difference -0.40 days; 95% confidence interval -0.76 to -0.03; P=0.03; I2 73%; 12 studies). No statistically significant differences were found between neuraxial and general anaesthesia for mortality, surgical duration, surgical site or chest infections, nerve palsies, postoperative nausea and vomiting, or thromboembolic disease when antithrombotic prophylaxis was used. Subgroup analyses failed to find statistically significant interactions (P>0.05) based on risk of bias, type of surgery, or type of neuraxial anaesthesia. CONCLUSION: Neuraxial anaesthesia for total hip or total knee arthroplasty, or both appears equally effective without increased morbidity when compared with general anaesthesia. There is limited quantitative evidence to suggest that neuraxial anaesthesia is associated with improved perioperative outcomes. Future investigations should compare intermediate and long-term outcome differences to better inform anaesthesiologists, surgeons, and patients on importance of anaesthetic selection.


Subject(s)
Anesthesia, Epidural/statistics & numerical data , Anesthesia, General/statistics & numerical data , Anesthesia, Spinal/statistics & numerical data , Arthroplasty, Replacement, Hip , Arthroplasty, Replacement, Knee , Comparative Effectiveness Research/statistics & numerical data , Humans , Length of Stay/statistics & numerical data , Postoperative Complications/epidemiology , Prospective Studies , Randomized Controlled Trials as Topic , Treatment Outcome
4.
Appl Clin Inform ; 6(3): 565-76, 2015.
Article in English | MEDLINE | ID: mdl-26448798

ABSTRACT

BACKGROUND: With increasing numbers of hospitals adopting electronic medical records, electronic search algorithms for identifying postoperative complications can be invaluable tools to expedite data abstraction and clinical research to improve patient outcomes. OBJECTIVES: To derive and validate an electronic search algorithm to identify postoperative thromboembolic and cardiovascular complications such as deep venous thrombosis, pulmonary embolism, or myocardial infarction within 30 days of total hip or knee arthroplasty. METHODS: A total of 34 517 patients undergoing total hip or knee arthroplasty between January 1, 1996 and December 31, 2013 were identified. Using a derivation cohort of 418 patients, several iterations of a free-text electronic search were developed and refined for each complication. Subsequently, the automated search algorithm was validated on an independent cohort of 2 857 patients, and the sensitivity and specificities were compared to the results of manual chart review. RESULTS: In the final derivation subset, the automated search algorithm achieved a sensitivity of 91% and specificity of 85% for deep vein thrombosis, a sensitivity of 96% and specificity of 100% for pulmonary embolism, and a sensitivity of 100% and specificity of 95% for myocardial infarction. When applied to the validation cohort, the search algorithm achieved a sensitivity of 97% and specificity of 99% for deep vein thrombosis, a sensitivity of 97% and specificity of 100% for pulmonary embolism, and a sensitivity of 100% and specificity of 99% for myocardial infarction. CONCLUSIONS: The derivation and validation of an electronic search strategy can accelerate the data abstraction process for research, quality improvement, and enhancement of patient care, while maintaining superb reliability compared to manual review.


Subject(s)
Algorithms , Data Mining/methods , Electronic Health Records , Myocardial Infarction/diagnosis , Postoperative Complications/diagnosis , Pulmonary Embolism/diagnosis , Venous Thrombosis/diagnosis , Arthroplasty, Replacement, Hip/adverse effects , Arthroplasty, Replacement, Knee/adverse effects , Automation , Humans , Medical Informatics , Myocardial Infarction/etiology , Postoperative Complications/etiology , Pulmonary Embolism/etiology , Retrospective Studies , Venous Thrombosis/etiology
5.
Int J Obstet Anesth ; 24(1): 77-84, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25499809

ABSTRACT

With improvements in management and rehabilitation, more women with spinal cord injury are conceiving children. Physiologic manifestations of spinal cord injury can complicate anesthetic management during labor and delivery. Patients who delivered at Mayo Clinic, Rochester, Minnesota between January 1, 2001 and May 31, 2012 with a history of traumatic spinal cord injury were identified via electronic record search of all parturients. Eight patients undergoing nine deliveries were identified. Six deliveries (67%) among five patients (63%) involved a trial of labor. Among these deliveries, three (50%) occurred vaginally, all with successful epidural analgesia. Trial of labor failed in the remaining three patients, and required cesarean delivery facilitated via epidural (n=1), spinal (n=1) and general anesthesia (n=1). Three patients (33%) underwent scheduled cesarean delivery via epidural (n=1), spinal (n=1), and general anesthesia (n=1). Four patients having five deliveries had a history of autonomic hyperreflexia before pregnancy. One patient had symptoms during pregnancy, two patients had episodes during labor and delivery, and three patients described symptoms in the immediate postpartum period. These symptoms were not reported by any patient without a history of autonomic hyperreflexia. Neuraxial labor analgesia may have a higher failure rate in patients with spinal cord injury, possibly related to the presence of Harrington rods. Postpartum exacerbations of autonomic hyperreflexia are common in patients with a history of the disorder.


Subject(s)
Anesthesia, Epidural/methods , Anesthesia, General/methods , Anesthesia, Obstetrical/methods , Anesthesia, Spinal/methods , Paralysis/complications , Pregnancy Complications , Autonomic Dysreflexia/complications , Cesarean Section , Delivery, Obstetric , Female , Humans , Paraplegia/complications , Pregnancy , Quadriplegia/complications , Spinal Cord Injuries/complications
6.
Acta Anaesthesiol Scand ; 58(10): 1249-57, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25307710

ABSTRACT

BACKGROUND: Past research has explored patients' expectations about the informed consent process. However, it is currently unknown if the complexity of the surgical procedure influences the type of anesthesia-related risks that patients wish disclosed. This study explored fears of anesthesia-related complications and whether these changed based on severity of surgery classification. METHODS: Patients presenting to our pre-operative evaluation clinic from February 2013 to May 2013 were asked to participate in a survey-based study meant to evaluate their perception of five possible anesthetic risks (peripheral nerve injury, death, nausea and vomiting, heart attack and stroke) when confronted with differing levels of surgical severity. RESULTS: One thousand surveys were administered, and 894 were returned for an overall response rate of 89%. Fear of death was the greatest concern as compared to the other risk factors independent of the severity of surgery. The level of fear for all risk factors, with the exception of stroke and heart attack, were dependent on the severity of surgery. Fear of death decreased as the severity of surgery decreased (major 46%, moderate 38%, minor 25%). For major surgery, the fear of perioperative death differed significantly with age (P < 0.001); specifically, with increasing age came a lessened fear of death. CONCLUSION: Awareness by anesthesia providers of those fears that patients report may allow for a more personalized approach to providing information that may better allay anxiety. Further, these results may better tailor the informed consent process to one that meets particular patient concerns.


Subject(s)
Anesthesia/adverse effects , Anesthesia/psychology , Fear/psychology , Informed Consent/psychology , Surgical Procedures, Operative/adverse effects , Surgical Procedures, Operative/psychology , Adolescent , Adult , Age Factors , Aged , Data Collection , Educational Status , Female , Humans , Informed Consent/statistics & numerical data , Male , Middle Aged , Preoperative Care , Surveys and Questionnaires , Young Adult
7.
Br J Surg ; 99(1): 120-6, 2012 Jan.
Article in English | MEDLINE | ID: mdl-21948187

ABSTRACT

BACKGROUND: Accelerated recovery pathways may reduce length of hospital stay after surgery but there are few data on minimally invasive colorectal operations. METHODS: An enhanced recovery pathway (ERP) was instituted, including preoperative analgesia, limited intravenous fluids and opiates, and early feeding. Intrathecal analgesia was administered as needed, but epidural analgesia was not used. The first 66 patients subjected to the ERP were case-matched by surgeon, procedure and age (within 5 years) with patients treated previously in a fast-track pathway (FTP). Short-term and postoperative outcomes to 30 days were compared. RESULTS: Hospital stay was shorter with the ERP than the FTP: median (interquartile range, i.q.r.) 3 (2-3) versus 3 (3-5) days (P < 0·001). A 2-day hospital stay was achieved in 44 and 8 per cent of patients respectively (P < 0·001). Patients in the ERP had a shorter time to recovery of bowel function: median (i.q.r.) 1 (1-2) versus 2 (2-3) days (P < 0·001). Thirty-day complication rates were similar (32 per cent ERP, 27 per cent FTP; P = 0·570). Readmissions within 30 days were more common with ERP, but the difference was not statistically significant (10 versus 5 patients; P = 0·170). Total hospital stay for those readmitted was shorter in the ERP group (18 versus 23 days). CONCLUSION: ERP decreased the length of hospital stay after minimally invasive colorectal surgery.


Subject(s)
Colorectal Neoplasms/surgery , Digestive System Surgical Procedures/methods , Pain, Postoperative/prevention & control , Adult , Aged , Case-Control Studies , Colorectal Neoplasms/pathology , Defecation , Digestive System Surgical Procedures/adverse effects , Female , Humans , Interdisciplinary Communication , Length of Stay , Male , Middle Aged , Minimally Invasive Surgical Procedures/methods , Neoplasm Staging , Pain, Postoperative/etiology , Patient Care Team , Patient Readmission , Recovery of Function , Time Factors , Treatment Outcome
8.
Int J Obstet Anesth ; 20(2): 184-8, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21388803

ABSTRACT

A parturient with Fontan circulation required general anesthesia for urgent cesarean delivery and subsequent prolonged postoperative ventilation for newly-diagnosed pseudocholinesterase deficiency. Anesthetic management necessitated a thorough understanding of the hemodynamic principles of the Fontan circulation and physiologic adaptations during surgical delivery and recovery in the intensive care unit.


Subject(s)
Butyrylcholinesterase/deficiency , Cesarean Section , Fontan Procedure , Pregnancy Complications/physiopathology , Respiration, Artificial , Tricuspid Atresia/physiopathology , Adult , Female , Humans , Pregnancy , Tricuspid Atresia/surgery
9.
Shock ; 14(4): 460-4, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11049110

ABSTRACT

To determine whether iron-laden tissue subsequently stimulated to produce the stress ("heat shock") response-sustained injury, hindlimbs of male ND4 mice were injected with iron salts, hemin, or hemoglobin. The stress response was induced with sodium arsenite or with heat. Ulcers appeared at the injection site. Tissues were analyzed by three distinct techniques-electron microscopy, TUNEL stain, and agarose gel electrophoresis of low molecular weight DNA-which collectively suggest that the tissue injury is, at least in part, the consequence of accelerated apoptosis. The data suggest that the toxicity of free iron is amplified by induction of the stress (heat shock) response to signal a programmed response. This model and mechanism may have implications in pathological processes ranging from the cutaneous wounds of venous stasis disease to the tissue failure of multiple organ dysfunction.


Subject(s)
Apoptosis/drug effects , Apoptosis/physiology , Heat-Shock Response/physiology , Iron/toxicity , Ulcer/etiology , Animals , Hemin/administration & dosage , Hemin/toxicity , Hemoglobins/administration & dosage , Hemoglobins/toxicity , Injections, Subcutaneous , Iron/administration & dosage , Male , Mice , Muscle, Skeletal/drug effects , Muscle, Skeletal/injuries , Muscle, Skeletal/pathology , Ulcer/pathology
10.
Arch Surg ; 132(12): 1283-7; discussion 1287-8, 1997 Dec.
Article in English | MEDLINE | ID: mdl-9403531

ABSTRACT

OBJECTIVE: To determine whether prior heat shock would attenuate endothelial cell apoptosis and whether any effect of preemptive heat shock is mediated through a nuclear factor kappa B and inhibitor kappa B alpha mechanism. DESIGN: A randomized, controlled in vitro study. SETTING: A laboratory in a large, academic medical center. INTERVENTIONS: Cultured primary porcine endothelial cells were treated with increasing doses of sodium arsenite (40-160 micromol/L), after which the interval until subsequent apoptotic (lipopolysaccharide-arsenite) challenge was varied (4-16 hours). The degree of cell death and apoptosis were determined using neutral red uptake and staining with annexin V and propidium iodide, respectively. Inducible heat shock protein 70 and inhibitor kappa B alpha levels in treated cells were determined by Western blot analysis. Lipopolysaccharide-induced nuclear factor kappa B activity was assessed using an electrophoretic mobility shift assay. RESULTS: Prior arsenite treatment decreased cell death by apoptosis in a time- and dose-dependent manner. Specifically, a higher sodium arsenite concentration and shorter intervals afforded better protection (P=.01, 160 micromol/L at 4 hours). Protection against apoptosis correlated with increased heat shock protein 70 and inhibitor kappa B alpha levels and decreased nuclear factor kappa B binding activity. CONCLUSIONS: Arsenite, an inducer of the heat shock response, decreased stress-induced endothelial cell apoptosis. The mechanism of this protection may include decreased nuclear factor kappa B activity or increased inducible heat shock protein 70 levels. Heat shock protein 70 may serve as a molecular marker to determine not only the phenotypic state of the cell but also the durability of protection afforded by heat shock. These data support the hypothesis that stress-induced changes in transcription factor activity and protein expression can regulate the induction of apoptosis.


Subject(s)
Apoptosis/physiology , HSP70 Heat-Shock Proteins/physiology , Heat-Shock Response , NF-kappa B/physiology , Animals , Apoptosis/drug effects , Arsenites/pharmacology , Blotting, Western , Electrophoresis , Endothelium/cytology , Sodium Compounds/pharmacology , Sulfhydryl Reagents , Swine
11.
Surgery ; 122(2): 243-53; discussion 254, 1997 Aug.
Article in English | MEDLINE | ID: mdl-9288129

ABSTRACT

BACKGROUND: Iron participates in diverse pathologic processes by way of the Fenton reaction, which catalyzes the formation of reactive oxygen species (ROS). To test the hypothesis that this reaction accelerates apoptosis, we used human umbilical vein endothelial cells (HUVECs) as surrogates for the microvasculature in vivo. METHODS: HUVECs were loaded with Fe [III](ferric chloride and ferric ammonium citrate) with 8-hydroxyquinoline as carrier and were then challenged with two stimuli of the heat shock response, authentic heat or sodium arsenite. Iron dependence was tested with two chelators, membrane-impermeable deferoxamine and membrane-permeable o-phenanthroline. The role of ROS was assessed with superoxide dismutase, catalase, and the reporter compound dichlorofluorescein diacetate. The mechanism of cell death was assessed with three complementary techniques, Annexin V/propidium iodide labeling, the TUNEL stain, and electron microscopy. RESULTS: Iron-loaded HUVECs executed apoptosis after a heat shock stimulus. Iron-catalyzed formation of ROS appeared to be a critical mechanism, because both chelation of iron and enzymatic detoxification of ROS attenuated this apoptosis. CONCLUSIONS: Inorganic iron, in concert with chemical and physical inducers of the heat shock response, may trigger apoptosis. The accumulation of iron in injured tissue may thereby predispose to accelerated apoptosis and account, in part, for poor wound healing and organ failure.


Subject(s)
Endothelium, Vascular/cytology , Endothelium, Vascular/physiology , Ferric Compounds/pharmacology , Quaternary Ammonium Compounds/pharmacology , Cell Survival/drug effects , Cells, Cultured , Chlorides , Deferoxamine/pharmacology , Drug Carriers , Endothelium, Vascular/drug effects , Ferric Compounds/pharmacokinetics , Free Radicals/metabolism , Hot Temperature , Humans , Iron Chelating Agents/pharmacology , Kinetics , Microcirculation , Models, Biological , Oxyquinoline , Phenanthrolines/pharmacology , Quaternary Ammonium Compounds/pharmacokinetics , Reactive Oxygen Species/metabolism , Umbilical Veins
12.
Biomed Sci Instrum ; 34: 380-5, 1997.
Article in English | MEDLINE | ID: mdl-9603070

ABSTRACT

There is debate among orthopaedists about the efficacy of steroid therapy to treat painful joints. Using an uncontrolled, retrospective study, we examined the usefulness of local corticosteroid injections in thirty-one patients (twenty-four men, seven women) with isolated AC joint arthropathy. No patients had signs of impingement or rotator cuff disease. All injections were performed using a standardized technique with each patient receiving 1cc Celestone/Soluspan or Dexamethasone and 2cc Lidocaine. At an average follow-up of nineteen months, patients were asked to answer questions regarding activity of daily living, according to the American Shoulder and Elbow Surgeons (ASES) format, average level of pain, length of pain relief from steroid injection, and time to return to full activity. Four patients could not be contacted for follow-up questions and, therefore, were excluded from the study leaving twenty-seven patients. Pain and function improved in twenty-five of twenty-seven (93%) patients after injection. Mean duration of improvement was twenty days (range, two hours to three months). Two patients reported continued relief at 1.5 and two years after injection. Due to persistent, insidious pain, eighteen of twenty-seven (67%) patients underwent distal clavicle excision an average of four months after injection. Overall, twenty-two of twenty-seven (81%) patients failed to obtain long-term relief from the injection. The results of this study suggest that the administration of local corticosteroids into the AC joint may provide short-term pain relief, but does not alter the natural progression of disease.


Subject(s)
Acromioclavicular Joint , Anti-Inflammatory Agents/administration & dosage , Glucocorticoids/administration & dosage , Adult , Aged , Betamethasone/administration & dosage , Dexamethasone/administration & dosage , Female , Humans , Injections, Intra-Articular , Male , Middle Aged , Osteoarthritis/drug therapy , Pain Measurement , Retrospective Studies
13.
Am J Physiol ; 266(2 Pt 2): F254-8, 1994 Feb.
Article in English | MEDLINE | ID: mdl-7511344

ABSTRACT

The relative roles of the adenylate cyclase-protein kinase A system (AC-PKA), the phospholipase C-protein kinase C system (PLC-PKC), and increases in cytosolic calcium in mediating the final actions of parathyroid hormone (PTH) remain ill defined. Although an important role for the PLC-PKC system in the regulation of phosphate transport in response to PTH has been suggested, previous studies from our laboratory and others, in OK cells, have emphasized the major role of AC-PKA. The present studies were designed to dissociate the second messengers for PTH by using an inhibitor of PLC (U-73,122). Studies were performed in confluent cultures of OK cells with and without preincubation with U-73,122 (1 microM). This inhibitor did not alter adenosine 3',5'-cyclic monophosphate (cAMP) production or the activation of PKA in response to PTH. Preincubation with U-73,122, however, totally abolished PTH-stimulated increases in diglyceride mass, consistent with inhibition of PLC. Activation of particulate PKC was then examined in response to PTH in the absence and presence of U-73,122. Although PTH resulted in an increase in particulate PKC activity in control cultures, this effect was abolished in the presence of U-73,122 and actually decreased significantly. Therefore, having documented marked attenuation of PLC-PKC, we next examined the effects of PTH on phosphate transport. Basal phosphate uptake was not altered by 1 microM U-73,122. Dose-response curves of the inhibition of phosphate transport in response to PTH were identical in the presence or absence of U-73,122. Thus inhibition of PLC and PKC activities did not alter the effects of PTH on phosphate transport.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Cyclic AMP/metabolism , Estrenes/pharmacology , Kidney/metabolism , Parathyroid Hormone/pharmacology , Pyrrolidinones/pharmacology , Type C Phospholipases/antagonists & inhibitors , 1-Methyl-3-isobutylxanthine/pharmacology , Animals , Cells, Cultured , Cyclic AMP-Dependent Protein Kinases/metabolism , Kidney/drug effects , Kinetics , Opossums , Peptide Fragments/pharmacology , Rats , Teriparatide
14.
Endocrinology ; 134(1): 331-6, 1994 Jan.
Article in English | MEDLINE | ID: mdl-7506208

ABSTRACT

Although PTH is known to stimulate both the adenylate cyclase/protein kinase-A system and the phospholipase-C/protein kinase-C second messenger systems, the relative roles of these second messenger pathways remain unclear. The present studies were designed to examine the effect of triamcinolone on PTH-stimulated second messenger systems and phosphate transport in confluent cultures of opossum kidney cells. Triamcinolone was added to these cultures at a concentration of 10 nM for 24-48 h. Neither cell number nor protein content was changed by this treatment. The addition of triamcinolone did not alter PTH receptor binding or competitive displacement radioligand binding assay curves. PTH-stimulated cAMP generation and activation of protein kinase-A were not altered by triamcinolone. The glucocorticoid, however, increased basal phosphate uptake from 1.0 +/- 0.1 to 1.28 +/- 0.1 pmol/5 min.culture (P < 0.01). Phosphate transport was significantly decreased by PTH (0.01 nM) in the triamcinolone-treated cultures, but not in control cultures. Phosphate uptake in the presence of maximal doses of PTH was similar in both control and triamcinolone-treated cultures. Thus, the PTH-responsive component of phosphate transport was preserved, and the threshold dose for the effect of PTH was reduced after treatment with triamcinolone. Studies were then performed to evaluate the alternate second messenger pathway. In control cultures, PTH rapidly increased the level of diglyceride mass, as measured by diglyceride kinase assay, from 0.18 +/- 0.01 to a peak of 0.26 +/- 0.02 mol/100 mol total phospholipid (P < 0.002), 1 min after addition of the hormone. Triamcinolone pretreatment for 48 h, however, elevated the basal diglyceride levels, but the increase after the addition of PTH was totally abolished. The absence of an increase in diglyceride upon stimulation with PTH correlated with elimination of the PTH-stimulated increase in the activity of particulate protein kinase-C. Thus, in triamcinolone-treated cells, the effect of PTH on phosphate transport was preserved, and the threshold dose of PTH-induced alteration in phosphate transport was reduced in the absence of stimulation of this alternate second messenger pathway. These data show that triamcinolone in opossum kidney cells does not alter PTH activation of the cAMP/protein kinase-A system, but eliminates the increase in diglyceride and the activation of protein kinase-C in response to PTH. These studies emphasize the major role of the protein kinase-A system in the regulation of phosphate transport by PTH.


Subject(s)
Kidney/metabolism , Parathyroid Hormone/pharmacology , Phosphates/metabolism , Second Messenger Systems/drug effects , Triamcinolone/pharmacology , 1-Methyl-3-isobutylxanthine/pharmacology , Animals , Biological Transport/drug effects , Cell Line , Cyclic AMP/metabolism , Cyclic AMP-Dependent Protein Kinases/metabolism , Diglycerides/biosynthesis , Kidney/cytology , Opossums , Protein Kinase C/metabolism , Reference Values
15.
Carcinogenesis ; 13(3): 447-51, 1992 Mar.
Article in English | MEDLINE | ID: mdl-1312397

ABSTRACT

Regulation of arachidonic acid metabolism was investigated in an SV40 immortalized, non-tumorigenic human urothelial cell line (SV-HUC). This cell line is being used to evaluate the multistage carcinogenic process. Media from confluent cultures were analyzed for radioimmunoassayable prostaglandin E2 (PGE2). A variety of agonists, including 12-O-tetradecanoylphorbol-13-acetate (TPA) and A23187 were tested and did not increase PGE2 synthesis within 2 h of addition. This was not due to the lack of prostaglandin H synthase activity because addition of exogenous arachidonic acid increased PGE2 synthesis. Cultures prelabeled overnight with [3H]arachidonic acid failed to increase the release of radioactivity following agonist addition. Thus, the lack of an early response in SV-HUC appears to be due to decreased release of endogenous arachidonic acid by phospholipase(s). After a 24 h incubation with 0.1 microM TPA or 1.0 microM A23187, the addition of arachidonic acid elicited significantly more PGE2 synthesis in agonist-treated cells than it did in control cells. Microsomes from 24 h TPA-treated cells produced approximately 15-fold more PGE2 than did those from control cells. In addition, the PGE2 content of overnight media was significantly greater in TPA-treated cells than in control cells. The 24 h agonist response was blocked by cycloheximide and staurosporine--inhibitors of protein synthesis and protein kinase C respectively. Pretreatment of cells with aspirin, an irreversible inhibitor of prostaglandin H synthase, prior to addition of TPA did not prevent the late 24 h TPA-mediated increase in PGE2 synthesis. Results suggest that this late effect of TPA is due to de novo synthesis of prostaglandin H synthase. Thus, SV-HUC has lost the early but retains the late response to agonists.


Subject(s)
Arachidonic Acid/metabolism , Calcimycin/pharmacology , Dinoprostone/biosynthesis , Diterpenes , Tetradecanoylphorbol Acetate/pharmacology , Aspirin/pharmacology , Bradykinin/pharmacology , Cell Line, Transformed , Microsomes/metabolism , Prostaglandin-Endoperoxide Synthases/biosynthesis , Simian virus 40 , Terpenes/pharmacology , Urinary Bladder/cytology
16.
J Cell Physiol ; 150(1): 214-9, 1992 Jan.
Article in English | MEDLINE | ID: mdl-1730784

ABSTRACT

TPA regulation of prostaglandin H synthase activity in primary and subcultured dog urothelial cells was investigated. Previous studies have demonstrated an early (0-2 hr) increase in PGE2 synthesis mediated by TPA which is dependent upon release of endogenous arachidonic acid by a phospholipase-mediated pathway. In this study, prostaglandin H synthase activity was assessed directly with microsomes and indirectly after addition of exogenous arachidonic acid at a maximum effective concentration (100 microM) to media. PGE2 synthesis, measured by radioimmunoassay, served as an index of prostaglandin H synthase activity. After a 24-hr incubation with 0.1 microM TPA or 1.0 microM A23187, arachidonic acid elicited significantly more PGE2 synthesis in agonist-treated cells than it did in control cells in primary culture. Microsomes from 24-hr TPA-treated cells exhibited significantly more prostaglandin H synthase activity than did those from control cells. In addition, the PGE2 content of overnight media was approximately 10-fold greater in TPA-treated cells than in control cells. The late (24 hr) response was more sensitive to lower concentrations of TPA than was the earlier (0-2 hr) response. TPA at 0.1 microM was a maximum effective dose for both responses. The 24-hr response was blocked by cycloheximide and staurosporine, inhibitors of protein synthesis and protein kinase C, respectively. Pretreatment of cells with aspirin, an irreversible inhibitor of prostaglandin H synthase, prior to addition of TPA did not prevent the late TPA-mediated increase in PGE2 synthesis. Subcultured cells exhibited both an early and a late TPA response. Only the early response was inhibited by aspirin pretreatment. Results suggest that the late response with TPA is caused by de novo synthesis of prostaglandin H synthase. Thus, primary and subcultured dog urothelial cells possess two distinct mechanisms for regulating signal transduction by arachidonic acid metabolism. This study provides a basis for assessing these mechanisms of signal transduction in urothelial cell lines and transformed cells.


Subject(s)
Prostaglandin-Endoperoxide Synthases/metabolism , Urinary Bladder/enzymology , Alkaloids/pharmacology , Animals , Arachidonic Acid/metabolism , Aspirin/pharmacology , Cells, Cultured , Cycloheximide/pharmacology , Dinoprostone/biosynthesis , Dogs , Staurosporine , Tetradecanoylphorbol Acetate/pharmacology , Urinary Bladder/cytology
17.
Carcinogenesis ; 12(8): 1459-63, 1991 Aug.
Article in English | MEDLINE | ID: mdl-1650292

ABSTRACT

Forskolin-mediated increase in cyclic AMP and subsequent activation of protein kinase A were evaluated in SV40-immortalized human urothelial cells. This cell line is being used to evaluate the multistep carcinogenic process. Forskolin elicited a time- and dose-dependent increase in cyclic AMP. Increases in intracellular cyclic AMP preceded media increases in cyclic nucleotide. Large increases in intracellular cyclic AMP occurred within 5 min of forskolin addition. The lowest effective concentration of forskolin was between 0.1 and 1.0 microM. Cyclic AMP increases as large as 20- to 100-fold were observed in cells and media following forskolin addition. A 60 min preincubation with 12-O-tetradecanoylphorbol-13-acetate (TPA) did not reduce the magnitude of the forskolin increase in cyclic AMP. TPA has been shown to affect cyclic AMP metabolism in many types of cells including primary and secondary cultures of urothelial cells. In the latter, preincubation with TPA reduces the magnitude of the forskolin increase. A 4.2-fold increase in protein kinase A activity was observed within 0.5 min of forskolin addition, while only small increases in cyclic AMP (1.6-fold) were detected within 1 min. Much more cyclic AMP is synthesized than is needed to maximally activate protein kinase A. While results demonstrate a forskolin-responsive cyclic AMP system, this system does not appear to be regulated by TPA. Lack of regulation of this second messenger system by TPA may be part of the immortalization process.


Subject(s)
Cyclic AMP/biosynthesis , Protein Kinases/biosynthesis , Urinary Bladder Neoplasms/metabolism , Cell Line, Transformed , Colforsin/pharmacology , Enzyme Activation/drug effects , Humans , Simian virus 40
18.
Cancer Genet Cytogenet ; 45(1): 67-71, 1990 Mar.
Article in English | MEDLINE | ID: mdl-2302687

ABSTRACT

We report here a case of acute nonlymphocytic leukemia evolving from a myelodysplastic syndrome which developed in an elderly man who had received radiation therapy for a prior cancer. Cytogenetic analysis revealed the following karyotype: 47,XY, + 8,t(1;6)(p13;p23). The breakpoints in the translocation are in the regions of the NRAS1 and PIM1 oncogenes on chromosomes 1 and 6, respectively. This translocation has not been previously observed in hematological malignancies.


Subject(s)
Chromosomes, Human, Pair 1 , Chromosomes, Human, Pair 6 , Leukemia, Myeloid, Acute/genetics , Leukemia, Radiation-Induced/genetics , Translocation, Genetic , Aged , Chromosome Banding , Humans , Karyotyping , Male , Neoplasms/radiotherapy
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